KR20100085791A - The control and management equipment of battery stack, and method there of - Google Patents

Abstract

PURPOSE: A control management device of a storage battery pack and a method thereof are provided to prevent accidents in advance. CONSTITUTION: An output current sensing unit(16) senses charging/discharging current or measured current signals of the storage battery pack. A boost converter(3) is comprised of multiphase structure for increasing the output voltage of the storage battery pack. A monitoring controller(2) watches the aging condition or abnormal condition of the storage battery pack. A gate cutoff unit(18) blocks the current flow of a switching device or a cutoff switch of the boost convertor. A switch controller engages with the gate cutoff unit and controls the switching device of the boost convertor.

Description

The control and management equipment of the battery pack and the method {The control and Management Equipment of Battery Stack, and Method there of}

In addition, as demand for alternative energy due to depletion of oil resources and environmental pollution, demand for accumulators that can accumulate and use electric energy is spreading to various fields such as alternative energy storage systems such as fuel cells.

Recently, electric vehicles such as hybrid (HEV) vehicles, electric vehicles, electric bicycles, golf carts, and the like have a high power density such as large-capacity lithium ion, lithium polymer, and nickel metal hydride batteries for the purpose of increasing driving speed and maximum driving distance. High battery capacity is on the rise.

Presented in the IEEE Journal in 2008 (author: Bill Kramer, Sudipta Chakraborty, Benjamin Kroposki National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, USA), "A Review of Plug-in Vehicles and Vehicle-to-Grid Capability." "The paper argues that commercialization will increase rapidly in the future when the cost of electricity is low even when considering the fluctuation of gas value when the plug-in vehicle (PEV) is used for commercial power or V2G. The National Renewable Energy Laboratory (NREL) reports that it has established standards for using commercial power.

In addition, in the case of gasoline vehicles, just as fuel gauges provide the driver with important information, it is very important for the driver to be able to accurately predict the distance that an electric vehicle can travel without recharging the battery. Techniques for accurately measuring SOC or currently stored charge remaining capacity have been studied in the past.

Lithium-based batteries used in small mobile devices such as mobile phones and laptops already have commercially available smart ICs to impart smart battery functions.However, in the case of large-capacity lithium batteries, they cannot be covered by conventional smart ICs. Systemized BMS technology must be applied.

Looking at the research reports of these fields, the state of charge of the battery is used in a very broad sense, referred to as "SOH", the state of charge of the battery represents the SOC as the meaning of the battery pack (Stack) ( Full) The percentage of the currently charged capacity (charging remaining capacity) compared to the Battery Storage Capacity Maximum is defined as "SOC (%)", and a few documents call SOC the remaining capacity. .

According to a recent paper or report, lithium ion, lithium polymer, and nickel hydride batteries are also known to be able to determine the aging progress by the internal resistance measurement method of the secondary battery.

The battery manufacturers refer to the point of end of life when the capacity reduction rate is 80% based on the rated design capacity, and the actual remaining discharge capacity can be measured by the actual load discharge test, but such a real load discharge test is complicated. Due to the long time-consuming disadvantage, IEEE 1188 (Institute of Electrical and Electronic Engineers) has established aging status check and maintenance standards for sealed lead-acid batteries, with 80% capacity when the internal resistance is increased to 130% above the initial standard. It is deemed to have been deteriorated and it is recommended to replace it.

In the patent application "Measurement device and method for measuring internal impedance effective components", filed with the Republic of Korea on September 13, 2006 and registered on March 05, 2008 (Registration No. 10-0812760), the life is terminated as described above. An example of a method of measuring an internal resistance value of a battery without separating the battery from the operating system as a measure for screening the battery is provided. Particularly, a battery pack or a unit cell is generated by generating a square wave measurement current that is relatively easy to generate. The present invention proposes a circuit and a method for calculating an internal resistance or an internal impedance component through a calculation algorithm of a voltage signal generated from a terminal voltage of a battery by the measured signal.

In addition, in the case of gasoline cars, it is not difficult to measure the amount of fuel, but due to the driving environment of the electric vehicle, it takes much longer to recharge than the gasoline vehicle, so how much energy is left in the driver of the electric vehicle now and in the future Information about how much longer you can drive is very important. Therefore, many techniques have been studied in the past to accurately determine the state of charge or remaining capacity of the battery to inform the driver of the driving distance and the like.

Residual capacity (alternative capacity) measurement algorithm of battery is based on the results of various studies, and the representative one measures the pack voltage of battery and calculates remaining capacity based on correlation graph between DC voltage and SOC (State Of Charge). The second method is a method of calculating the remaining capacity of the battery by adding or subtracting the total amount of electricity charged in the battery and the total amount of electricity discharged through driving and the like. In some cases, a mixture of the two methods was used.

The patent filed in the Republic of Korea on January 31, 2005 and registered on April 06, 2007 (Registration No. 10-0704944, Battery Management System for Electric Vehicles) relates to a battery management system for electric vehicles. A sensor module connected to measure temperature and voltage; A charge / discharge circuit connected to each of the batteries to charge and discharge the connected battery according to an external control signal; And controlling the charge / discharge circuit to charge the respective batteries, and control the charge / discharge circuit to discharge the respective batteries for a predetermined time to remove the stray voltage at the time of checking the remaining capacity of the respective batteries. And a battery management device for calculating a remaining capacity of each battery by calculating a slope of a curve in which the battery voltage is recovered by the information output from the sensor module.

In addition, the patent for SOC estimation method of the battery filed in the Republic of Korea on October 20, 2005 and published on April 25, 2007 and the battery management system (Application No. 10-2005-0099088) using the same correspond to the cumulative total discharge amount. A method for estimating the SOC of a current battery using the total battery capacity that is present is presented.

That is, the battery management system is a battery management system that manages a battery that outputs the SOC of the battery to the ECU of the vehicle using electricity, and includes a detector, an SOH estimator, an SOC estimator, a total battery capacity determiner, and an output unit. The detector measures the pack current and the pack voltage of the battery, the SOH estimator outputs the SOH using the pack current and the pack voltage, and the SOC estimator calculates and outputs the SOC using the pack current and the total battery capacity of the battery.

The total battery capacity determining unit accumulates the total discharge accumulation amount using the pack current, and determines the total battery capacity according to the accumulated total discharge accumulation amount and delivers the total battery capacity to the SOC estimator. It provides a method to estimate the SOC of a battery more accurately by integration and a battery management system using the same.

In the test data presented in the cited patent, the total battery capacity of the battery is shown to decrease when the ambient temperature during the charging and discharging of the battery is low, but there is no specific technique regarding the charging and discharging efficiency of the battery. The practitioner would not know about this and would be difficult to trust that the SOC (%) estimation method is accurate. In addition, as the capacity decreases as the charge and discharge cycle increases during actual use of the battery pack, the total battery capacity (TAC) based on the total amount of discharge accumulated in the long-term discharge (for example, 40,000 to 100,000 cycles) test is used as a way to compensate for this. A method of calculating SOC based on the total battery capacity (TAC) and pack current is used.

However, in the method of calculating the SOC as described above, it is very difficult to derive the tabled information of the total battery capacity (TAC) relative to the total discharge amount through a long time discharge (for example, 40,000 to 100,000 cycles) test according to each use temperature. Although the SOH estimator is described as outputting the SOC of the battery based on the pack current, the pack voltage, the temperature, and the like, the SOH estimator cannot accurately estimate the SOH without considering the correlation factors according to the aging state of the battery.

In addition, the patent of the battery state estimation method and device (Registration No. 10-0756837), filed in the Republic of Korea on June 29, 2006 and published on January 05, 2007, serves as a parameter that has the greatest effect on the SOH of the battery. An object of the present invention is to provide an SOH estimation method and apparatus for estimating SOH using an internal resistance known to be known.

In order to achieve the above object, the method of estimating the SOH of the battery of the cited invention includes: storing an SOH estimation table configured with an SOH value corresponding to various internal resistances by temperature and SOC; Upon requesting an SOH estimate, measuring temperature and estimating the SOC of the battery; Detecting an internal resistance of the battery; And reading an SOH value corresponding to the measured temperature, the estimated SOC of the battery, and the detected internal resistance of the battery, from the SOH estimation table.

Measuring the battery internal resistance by temperature and SOC based on the SOH of the battery divides the SOH into five stages, and repeats the measurement of the battery internal resistance by temperature and SOC at each step. In each step, measurements of battery internal resistance by temperature and SOC are completed, and an SOH estimation table is constructed based on each measurement result. Since different SOH values are mapped to temperature, SOC, and battery internal resistance, the SOH estimation table reads an SOH value corresponding to the detected internal resistance of the battery from the SOH estimation table.

Since the cited patents have different SOH values corresponding to temperature and SOC for each battery pack, the SOH values corresponding to temperature, SOC, and battery internal resistance must be obtained according to various stages of experiment. There is a hassle of mapping work test volume.

In addition, the patent of the method for measuring the remaining amount of a secondary battery and its device (Registration No. 10-0372879), which was filed in the Republic of Korea on December 13, 2000, and published on May 7, 2001, is based on the total remaining amount of the individual battery according to the actual degree of deterioration. By correcting the accuracy of the variation calculation,

The present invention provides a method and apparatus for measuring the remaining amount of a secondary battery, which may be used as cycle count data that changes accordingly, to reflect a change in battery characteristics.

The cited invention relates to a method for measuring a residual amount of a secondary battery based on a cycle count of a battery, the method comprising: measuring a charge / discharge current value of a secondary battery; Measuring an error of an electric power decrease value (EPA) of each battery; Measuring an error of a charge current change value (CCA) according to a charge voltage change using the charge / discharge current value; Calculating a mean temperature correction coefficient K for each cycle count; An error (EPA) of the decrease in power amount of each battery cycle, an error of the charge current change value (CCA) according to the change of the charging voltage, and an average temperature correction coefficient (K) for each cycle count are generated as a residual control purge (RCF) value. And counting cycles of a secondary battery using the charge / discharge current value and the remaining amount control purge value. It contains very complex algorithmic steps such as

As described above, the high density of Li-Ion and Li-PB batteries are very weak against cell voltage imbalance, overcharge, overdischarge, or use temperature conditions. Therefore, the unit cells of the battery pack may be used for safe use. In addition to the characteristic parameters such as voltage, internal resistance, and cell temperature, the charge / discharge voltage, current, charge / discharge state (overvoltage or overcurrent) of the battery pack, and the presence or absence of output short-circuit are collectively managed. It is necessary to protect the battery pack by immediately stopping charging and discharging when an abnormal symptom is found by providing a power converter (step-up converter) controlling its output at the output stage of the battery pack. .

In addition, in the electric vehicle, an electric converter such as a motor driving device is manufactured at cost and conversion thereof. In the aspect of improving the efficiency of the system due to the driving, the trend is actually requiring a DC voltage of 300V or more, but the battery pack (Stack) capable of outputting a DC voltage of 300V or more actually required, because many unit cells are configured in series, BMS Since the circuit between the circuit and the unit cell becomes more complicated, and as the complexity increases, the probability of failure increases, so it is desirable to design as few series-connected numbers of unit cells as possible.

In addition, a battery pack (Stack) for an electric vehicle used for a hybrid (HEV) vehicle, an electric vehicle, an electric bicycle, etc., needs to be able to shorten the waiting time before replenishing, and thus needs a fast charging as possible. This rapid charging and discharging increases the risk of explosion due to cell voltage imbalance, overvoltage, and temperature rise because the battery pack is easily exposed to conditions that may be overcharged, overheated, or cell imbalance. Can be. Therefore, a control management (BMS) system of a battery pack and a control method thereof capable of preventing this inevitably will be required.

In addition, as fuel gauge plays an important role in gasoline vehicles, it is very important information for the driver to be able to accurately predict the distance that can be additionally driven without newly charging the battery due to the characteristics of the electric vehicle. Considering the correlation factors according to the aging condition of the battery, SOC (%) calculation method is needed to estimate the exact SOH of the battery's aging use and to accurately measure the remaining capacity in consideration of the identified SOH.

According to the present invention, as the number of series cells of the battery cells increases, the circuit structure of the BMS becomes complicated and the connection points increase, so that the connection structure also becomes complicated and the reliability thereof may be degraded. A boost converter is installed at the output of the string to supply a high DC voltage of 300V or more, which is commonly required in electric vehicle electric systems, and boosts when an abnormality is detected in the supervisory control system of a battery pack. A battery with a built-in BMS function that prevents accidents such as breakage or explosion of the battery pack by blocking the gate element signal of the converter circuit and stopping the charging and discharging immediately. The purpose of the present invention is to propose a control management apparatus for a stack and its control management method.

In addition, in the circuit structure of a boost converter provided at the output stage of a battery pack, a DC power of several hundred KW or more required by an electric vehicle is converted to 300 V or more, and the back loss during conversion loss and discharge is minimized. An object of the present invention is to present a preferred embodiment of a boost converter and a control method thereof.

In addition, the present invention provides a preferred embodiment of a boost type converter capable of regenerative braking of an electric vehicle and a bi-directional control to charge a battery pack as a plug-in charger having a simple structure of rectifying a commercial AC power source using a diode rectifier circuit. do.

In addition, an embodiment of a cell equalization scheme for measuring the voltage of each unit cell to equalize the voltage of each unit cell when the voltage is higher than the other cell or higher than the maximum allowable voltage is in an unbalanced state.

In addition, in order to determine the SOH or replacement time of the battery pack, the internal resistance value of the battery, which is a factor correlated with the aging state, must be measured in the charge / discharge state. It is an object of the present invention to provide a preferred embodiment of the measurement current generating means required to measure the internal resistance as a specific embodiment of the component.

Another purpose is to calculate the remaining charge capacity (SOC) by continuously measuring the history of charge / discharge (usage) such as charge / discharge voltage and current, and by measuring the temperature, voltage and internal resistance of the battery unit cell in real time. The method to calculate the battery storage capacity of the battery according to the charging and discharging cycle based on the real-time measurement or monitoring of urea components that are required and correlated with the health status and according to the aging state of the battery Given the correlation factors (internal resistance, ambient operating temperature), we present a method to accurately measure SOH.

In addition, the present invention provides a battery pack by installing a memory means that can store the characteristics parameters such as internal resistance, temperature, cell voltage, charge and discharge cycles, charge and discharge history of the battery during charging and discharging It is possible to provide a way to easily manage the battery pack (Stack) in the charging station of the battery storage of the electric vehicle by being able to determine the performance, remaining life and need before replenishment.

According to the present invention, it is possible to prevent explosion due to overheating of a battery pack or cell voltage imbalance which may occur frequently during rapid charging and discharging, and to safely obtain a high DC voltage required in an electric system of an electric vehicle. have.

In addition, a battery with a built-in BMS function that can be used for rapid charging by connecting more than a hundred lithium-based unit cells having a high density to accumulate the battery for cycle service batteries for electric vehicles and electric bicycles in series. It is possible to provide a charge and discharge control and management apparatus and a method thereof.

Accurately measures the internal resistance associated with aging of the battery pack in the charged and discharged state to determine the SOH or replacement time of the battery pack. Also, various historical information according to the charge and discharge of the battery pack. Because it can be stored in the memory means built in the battery pack (Stack) it is possible to efficiently manage the battery pack (Stack) without using a separate measurement equipment or procedures.

The configuration of the present invention for achieving the above object is a boost converter for converting the output voltage of the battery pack (Stack) to supply a high DC voltage required in the electrical system, and the BMS function of each unit cell It includes a supervisory control means and an associated circuit configured to include an embedded device for performing.

In addition, as a technical term used in the present specification, "storage battery" may be converted into electrical energy into chemical energy or other forms of energy during charging, and may be stored and stored in chemical or other forms during discharge. Points to an object that can convert energy into electrical energy and output it. As used herein, the term "battery battery" refers to a battery of a broad range, and is representative of secondary batteries, including lead-acid capacitors, nickel-cadmium batteries, lithium batteries, and nickel-hydrogen batteries.

Hereinafter, the present invention will be described in detail according to the embodiments.

In the following detailed description, the principle of the present invention is described as an embodiment of a control management apparatus of a battery pack and a control management method thereof, but those skilled in the art may use other forms according to the disclosure herein. It can be clearly understood that the battery pack can be safely managed while charging and discharging the battery pack according to the control management method.

1 is a block diagram of a charge and discharge electric device of a battery pack (Stack) with a built-in BMS function.

The basic configuration of the charge / discharge control management device of the battery pack for supplying the DC power required for the electric system or the emergency power supply of the electric vehicle includes the abnormal state or the aging state of the battery pack and the charge / discharge. Supervisory control means (2) having an embedded device for monitoring the state and calculating and analyzing the characteristic elements of each unit cell; and,

A line fuse 4 which burns out at the output short-circuit of the battery pack and protects it or artificially separates the battery pack from the electrical system circuit;

Boosting output voltage of battery pack to high DC voltage and supplying / discharging function to supply DC power to electric drive system such as motor through DA / AC inverter device. A converter 3;

The monitoring control means may include a gate blocking signal (Cut) through a gate blocking means of an embedded device configured in the monitoring control means when an abnormality or an aging state or a charge / discharge state of a battery pack is detected or expected. off) to immediately block (block) the switching element of the boost converter and the gate of the cutoff switch so that charging and discharging can be stopped immediately so that the battery can be protected from abnormal conditions.

2 is a block diagram illustrating a control circuit for boosting control and BMS management of a battery pack according to an embodiment of the present invention.

The cell selecting means 12 connected to the positive and negative terminals of each unit cell of the battery pack 12 may include the voltage of each unit cell (monoblock) of the battery pack according to the sequential selection signal of the embedded device. Temperature, internal impedance voltage signal is connected to the signal sensing means (13). The internal specific circuit of the cell selection means 12 may comprise other electronic relays such as relays of mechanical contacts or FET relays.

The signal sensing means 13 is composed of a differential amplifier and a peripheral circuit thereof to insulate the cell voltage and the temperature signal obtained from the battery unit cell from the battery system voltage or to amplify it to an appropriate level signal in the case of an analog signal. In particular, the internal impedance voltage signal is obtained by including the DC voltage component measured at the battery pole terminal. Since it is a minute signal, it can be amplified in multiple stages after filtering the DC voltage through the waveform filtration circuit (filter) to improve the resolution. have.

The interface means 14 may be a charge / discharge current signal obtained from the output current sensing means 16, a cell voltage obtained from the signal sensing means 13, a voltage signal corresponding to a temperature, an internal impedance voltage signal, and / or a battery pack. The sensing current signal sensed by the stack is sensed and converted into a signal suitable for this so that the embedded device 15 can calculate various data of the battery. For example, if the allowable input voltage range of the A / D converter in the embedded device 15 is ± 12V, it is preferable to amplify or buffer the signal to fit this size, and to filter the signal and ripple component of the harmonic component that are unnecessary for operation.

The output current sensing means 16 senses the output current or the measured current signal flowing during charging and discharging of the battery system (pack), converts it into a voltage signal, and buffers or amplifies it. In detail, the output current sensing means 16 may measure a DC current using a Hall element and output the analog current signal corresponding to the measured current.

Measurement current generating means for generating a measurement current signal having a magnitude of tens A in the battery pack under test so that the impedance voltage signal of a relatively high level required for calculating the internal resistance can be induced at the unit cell terminal of the battery pack. It is preferable that (17) is further contained.

In addition, it is preferable to further include cell equalization control means 11 for measuring the unit cell voltage and controlling the unit cell to be uniform when the voltage is higher than the voltage of other cells or higher than the maximum allowable voltage.

The embedded device 15 basically receives and stores a cell voltage and temperature data value or calculates and receives an analog signal of cell voltage and temperature, and also measures the measured current signal obtained from the current sensing means 16 and the interface means 14. Based on the obtained internal impedance voltage signal, the internal resistance or internal impedance value is calculated by setting the real time period, and the measurement time is included in the calculation result and stored sequentially in the internal memory means. In addition, by analyzing the magnitude and pattern of the charge and discharge current obtained from the current sensing means 16, data on the number of charge and discharge cycles (cycles), the charge and discharge history into a database (DB) to date and information in the memory means; Store them together sequentially.

Lithium ion accumulators that are currently commercialized are very high in electrical integration and relatively inexpensive among secondary batteries, but are only used as a structure (smart battery) in which 3 to 4 units are connected in series by connecting BMS IC chips to small capacity. Like other secondary battery packs, dozens or more of unit cells are connected to a series system, so the risk of explosion is inherent. Therefore, it is not practical to use them in series connection (especially DC 300V or more) with a large capacity battery pack such as an electric vehicle. You have a technical problem to solve.

In other words, lithium-based battery packs are more dangerous than other rechargeable batteries, so in addition to basic management functions such as cell protection and charge remaining capacity measurement, the cell balancing control (Cell Balancing) is used to reduce the risk of explosion. Designing to perform the function first can be an essential solution to the large capacity.

If the charge / discharge cycle is increased by using a battery pack having several tens of unit cells connected in series for a long time, the characteristic voltages of each unit cell are not equal to each other, resulting in an unbalanced charging voltage of the unit cells. As a means to prevent this, cell balancing control is an essential requirement.

Even in the case of other secondary batteries, if the cell voltage is imbalanced, it accelerates aging of the battery system and shortens the lifespan such as capacity reduction.In particular, when lithium cell battery packs are imbalanced, a sudden characteristic change is caused. As cell explosion can occur, Cell Balancing is a very important control management operation.

Therefore, first, the monitoring control means 2 measures and calculates the unit cell voltage to be measured, and if it is determined that the value is higher than the voltage information of the other unit cell from time to time or is higher than the maximum allowable voltage of the cell, the embedded control means The device 15 causes the cell equalization control means 11 to control to equalize the monitored cell in the imbalanced state. This command always takes precedence over the measurement or other analysis of characteristic elements that are considered to be of low importance for battery management, such as the internal resistance of each cell.

According to a control command of the embedded device 15, when the target cell in an unbalanced state is connected to the cell equalization control means 11 through a cell selection means 12, the cell equalization control means 11 is operated, and the storage battery is operated. A part of the charging current of the pack (50% or less is preferable if the capacity of the hardware is considered) is controlled to be distributed (bypassed) through the cell equalization control unit 11 without charging a cell in an unbalanced state. The cell voltage at is more stable than other normal cells when the additional charging is stopped or the overcharged cell voltage is discharged.

The Cell Balancing function is continuously operated between chargers and is prioritized over other parameter measurement or analysis management of the battery unit cell.

The cell equalization control means 11 preferably constitutes a circuit with one active switch element and a load resistor for the purpose of simplifying the circuit configuration and control. When the active switch element is turned on, the charging current of the battery pack is distributed to a load resistor connected in series with the active switch element so that the amount of charge is reduced or the overcharged cell voltage is discharged.

In addition, the cell protection function (Cell Protection) for each cell has a variety of protection (overcharge blocking and termination, overvoltage blocking and termination, overcurrent blocking or termination, over-discharge blocking or termination, cell temperature overheating or termination, It protects the unit cell from explosion by performing the function of warning of excessive internal resistance of the unit cell.

The monitoring control means (2) detects the charge and discharge current of the battery pack from the current sensing means 16 to determine the number of charge and discharge cycles and calculate the size thereof. In addition, the cell selection means 12 detects the cell voltage, the temperature, and the impedance voltage signal of each unit cell, estimates the health state or the charge state of the battery pack, and manages the protection function to be performed.

The supervisory control means 2 compares and analyzes the cell voltage, temperature value, or internal resistance value calculated by the embedded device 15 with a predetermined set value to the corresponding unit cell (monoblock) of the battery pack. If it is determined that an abnormality has occurred or is expected, the embedded device 15 immediately outputs a preferential signal and causes the gate blocking means 18 to generate a gate blocking signal and send it to the boost type converter 3. The gate cut signal transmitted as described above may immediately stop (blocking) the gate of the cutoff switch 304 of the boost type converter 3 to stop charging or discharging. Thus, a battery pack may have an incorrect charge / discharge condition. It can be safely protected from the environment.

Accumulation of charge and discharge current is essential data for estimating charge remaining capacity (SOC) of battery pack. The charge remaining capacity measurement function integrates the cell characteristic data such as the number of charge / discharge cycles, unit cell health, cell temperature, and cell voltage into a calculation algorithm based on the integration of the amount of current measured during charge / discharge of the battery pack. Capacity (SOC) can be calculated.

In addition, the display device 19 connected to the output port of the embedded device 15 may be configured in the form of LCD or LED and monitors the operation state or abnormal state of the battery pack by the display device 19. If necessary, if necessary, by detecting the state and history database of the battery pack (Stack) stored in the memory means of the embedded device 15, and the characteristics and charge and discharge of the battery pack (Stack) performance or life History data can be viewed.

3 is a block diagram of a BMS circuit and a charge / discharge circuit of a battery pack according to another embodiment of the present invention, wherein the cell selecting means 12 is provided for each unit cell, and the measurement control module 21a, 21b ... 21n. It can be replaced by a signal selection means 21 composed of. Each measurement control module 21a, 21b ... 21n measures the characteristic parameters of each unit cell of the battery and stores them in the internal memory of the MCU 37 when necessary. The measured data is sequentially configured to be connected to the embedded device 15 through the serial communication line 39 of the analog switch (MUX) or the communication circuit 38, the embedded device 15 is charged and discharged of the battery pack The current magnitude and the characteristic element parameter of each unit cell measured by each measurement control module 21a, 21b ... 21n and transmitted by the control signal are inputted and analyzed.

12 is a detailed block diagram of the measurement control module 21a, 21b ... 21n according to an embodiment of the present invention. The voltage signal obtained from the battery unit cell is input to the A / D converter 36 through the differential voltage amplifier 1 31 through the impedance voltage measurement circuit 32 and the cell voltage detection circuit 33. In addition, the measurement current signal generated by the measurement current generating means 17 is input to the A / D converter 36 along the line 34 and the temperature signal detected by the temperature sensor 30 is differential amplifier circuit 2 (buffer) ( Inputted to the A / D converter 36 through 35), characteristic parameters of the unit cell, such as cell voltage, temperature, and internal resistance, are calculated by the calculation program of the MCU 37.

The characteristic parameter calculated by the MCU 37 may be transmitted to the embedded device 15 through a communication circuit 38 in a serial communication manner, and thus may be comprehensively analyzed and managed.

In addition, the communication circuit 38 is designed to communicate in both a transmission and a transmission direction, and when the target cell is found to be in an imbalanced state by the monitoring management of the embedded device 15, the control of the embedded device 15 is controlled. The command is transmitted to the cell equalization control circuit 42 through the communication circuit 38 so that a part of the charging current of the battery pack (preferably a few A or less in consideration of the capacity of the hardware) is added to the cell in an unbalanced state. The cell voltage in an unbalanced state is controlled to be bypassed through the cell equalization control means 42 without charging abnormally so that the charge amount is reduced and the voltage is stabilized.

On the other hand, when the measured current generated by the measurement current generating means 17 flows in the battery pack under test (Stack), the impedance voltage signal is caused by the internal impedance of the unit cell (monoblock) to the terminal of the battery pack under test (Stack). At this time, it is mixed with the electromotive force of the battery.

As a technique for measuring internal impedance or internal resistance, there are several methods, such as AC current injection method and momentary load discharge method (DC measurement), as is known in the art. The internal impedance or internal resistance value is derived from the relational expression between the impedance voltage signal and the measured current signal obtained in the battery unit cell.

As described above, in order to obtain the impedance voltage signal, a measurement current signal must be generated and flowed to the battery pack under test. In this case, the influence of the ripple voltage caused by the charge / discharge current or the noise voltage that can be induced from the outside can be obtained. In order not to receive the signal, the impedance voltage signal obtained from the battery terminal voltage must be much larger, and therefore a relatively large measurement current of several tens of amperes is required.

4 shows an embodiment of the measurement current generating means 17. As a preferred embodiment designed to easily generate a relatively large measurement current, the measurement current generating means 17 is composed of an inductor and two switching elements connected in series with the output terminal of the battery pack.

The switching legs are configured in series according to the polarity direction of the upper switch element 901 and the lower switching element 902 so that the upper 910, the interruption 920, and the lower 930 connection nodes are formed. The upper connection node 910 is connected with the positive terminal of the output capacitor 306, the lower connection node 930 is connected with the negative terminal of the output capacitor 306, and the interrupt connection node 920 is connected to the inductor. It is connected to one terminal of (907). In addition, the other terminal of the inductor 907 is connected to the positive terminal (+) of the battery pack (Stack).

The measuring current generating means 17 is composed of an inductor, which is a passive element connected to a terminal of a battery pack, and a switching element, which is two active elements, and can generate a high measurement current signal with higher efficiency than a linear control method. Can be. In addition, the upper switch element 901 and the lower switching element 902 are driven synchronously by the signal output from the embedded device 15, and as a result, the measurement current frequency is determined in the embedded device, thereby calculating the internal resistance value. The steps can be simplified.

FIG. 5 shows simulation waveforms of the measurement current and the battery system (pack) output current as an example of the operation waveform by the simu- lation of the measurement current generating means 15. According to the preferred embodiment illustrated in FIG. 4, it can be seen that the sine wave measurement current having a magnitude of 200 Hz (Hertz) and a maximum value of 50 A (Amp) before measurement is easily generated by the drive signal of the embedded device.

FIG. 6 illustrates an embodiment of the boost converter 3 according to the present invention, in which the switching legs of the main circuit are configured in four phases. Since the individual switching legs of each phase are the same in configuration and operation principle, description will be made with reference to the reference switching leg 301 in order to avoid repeated description of the following description.

The switching leg 301 is formed by connecting the upper switch element 302, the lower switching element 303, and the cutoff switch 304 in series in the polar direction to connect the upper 310, interrupt 320, and lower 330 connection nodes. It is configured to be formed. The upper connection node 310 is connected to the positive terminal of the output capacitor 306, and the lower connection node 330 is connected to the negative terminal of the output capacitor 306 or the negative terminal of the battery pack. ) Is connected to the terminal, and the interruption connection node 320 is connected to one terminal of the inductor 307. The other terminal of the inductor 307 is connected to the positive terminal (+) of the battery pack (Stack).

In order to implement zero voltage switching of the upper switching element 302 and the lower switching element 303, a snubber capacitor 305 may be configured in parallel to each switching element according to a designer's decision.

In addition, for protection of the switching element, the anode (+) of the diode 351 is connected to the connection node 340 between the cutoff switch 304 and the upper switching element 302 at the designer's discretion. The negative terminal is connected to the capacitor 352, and the other terminal of the capacitor is connected to the negative terminal of the output capacitor 306 or the negative terminal of the battery pack, and the capacitor 352 ) May further comprise a current pass circuit 350, characterized in that the resistor 353 is connected in parallel.

The upper switching element 302 and the lower switching element 303 are operated by the switch control means 20 and when the lower switching element 303 is switched on, the upper switching 302 is complementary, such as to be switched off. Is switched on / off. When the lower switching element 303 is turned on, the inductor current increases linearly and the magnetic energy in the inductor 307 increases due to the voltage of the battery system (pack) applied to the inductor 307.

Then, when the lower switching element 303 is turned off, the polarity of the voltage applied to the inductor 307 is inverted so that the inductor current decreases linearly and magnetic energy in the inductor is released to the output capacitor 306.

Accordingly, the amount of energy stored magnetically in the inductor 307 is controlled by Pulse Width Modulation (PWM), which controls the switch on / off time of the lower switching element 303, and the The output voltage is converted to the high DC voltage required by the electrical system.

The disconnection switch 304 is switched on in the normal operation such as when the boost converter 3 is operating or when the battery pack is being charged, so that the power of the battery system (pack) is supplied or charged to the load side. To allow.

However, as described above, the supervisory control means 2 analyzes the result of calculating or monitoring the charge / discharge voltage, the charge / discharge current, the cell voltage, the temperature value, the internal impedance or the internal resistance value in real time, and accumulate the battery pack. Alternatively, when it is determined that an abnormality has occurred in the unit cell (monoblock), the cutoff switch 304 is immediately switched off by the cutoff signal sent from the gate cutoff means 18 and stops the supply of power. ) Will be protected.

In addition, when abnormality is detected during charging, it is preferable to stop the control operation of the boost converter 3 by switching off the cutoff switch 304 to protect the battery pack.

In addition, the cutoff switch 304 is preferably a commercially available power semiconductor device such as an IGBT, but may be replaced by a relay or a switch having a mechanical contact structure, and in this case, the cutoff signal sent from the gate cutoff means 18 may be applied to the excitation coil. By blocking the excitation current, the relay or the switch may be turned off to protect the battery pack.

When an abnormality is sensed in the above step, when the cutoff switch 304 is switched off or the operation of the boost converter 3 is suddenly stopped, the free wheeling passage of the inductor current flowing in the inductor 307 is blocked. High voltages are induced across the inductor 307, which may cause overvoltages at both ends of the switching elements 302 and 303 or the cutoff switch 304, thereby damaging them.

In order to prevent such damage, when the current flowing through the inductor 307 flows in a negative-negative direction, the cutoff switch 304 is switched off or the operation of the boost converter 3 is stopped. The current of the inductor 307 is bypassed (bypassed) through the diode of the switch element 303 to prevent damage. However, since the control method is performed at the step of controlling the gate driving signal, the control may be somewhat complicated.

Therefore, the connection node 330 which is a connection point of the connection node 340 of the upper switch element 302 and the disconnect switch 304 and the negative terminal of the output capacitor 306 or the negative terminal of the battery pack Stack. It is preferable to provide a current pass circuit 350, which is a hardware circuit, so that current flowing in the inductor 307 is bypassed through the current pass circuit 350.

FIG. 7 is an example of a boost converter circuit having six switching phases of a main circuit, which is another preferred embodiment of the present invention. Since the hardware structure and operation principle of each switching leg are the same as those of FIG. 6, a person skilled in the art may easily understand this even if the operation process thereof is not described.

In the case of a typical boost converter having a switching leg composed of a single phase, the output current of the battery system (pack) and the inductor current are the same. On the other hand, in the boost type converter of FIG. 6 or 7 composed of four or six phases, the output current Ibat of the battery system pack is represented by the total sum of the inductor currents of each phase, and thus the harmonic ripple current in the output current Ibat. It is also represented by the sum of the harmonic ripple currents in the inductor current of each phase.

Pulse width modulation characterized in that each leg of the main circuit has a phase difference of (360 ° / constant) when defining one period of pulse width modulation for controlling the switching element of a boost converter as 360 °. When controlled by, the inductor current also has harmonic ripple phase difference of (360 ° / constant). Harmonic ripples with this phase difference cancel each other out in the output current Ibat, so that the harmonic ripple of the output current Ibat of the battery system (pack) decreases in magnitude and the harmonic frequency increases by (switching frequency * constant) times. Will be.

FIG. 8 shows a case in which a boost converter composed of six phases is controlled by pulse width modulation having a phase difference (360 ° / 6 phases) of 60 °, and is applicable to an electric system used in an electric vehicle. Each phase inductor current and battery system (pack) output current waveform is shown. Each phase inductor current has a relative phase difference of 60 ° to each other, and its individual ripple current peaks can reach 200 A (amps). In this case, as described above, it can be seen that the peak value of the ripple current is reduced to about 60 amps ( Amp) due to a cancellation effect between inductor currents having different phases in the battery system (pack) output current. In addition, it can be seen that the frequency of the ripple current of the battery pack corresponds to 6 times the inductor current ripple.

As described above, an operation mode and a current waveform are illustrated for four or six phases, but it is applicable to three phases, and when the phase of the switching leg is further increased, the switching is generated in the battery pack. Since the frequency of the ripple increases in proportion to the constant and the magnitude of the ripple current decreases, it is possible to construct the main circuit of the boost converter by increasing the constant of the circuit to an optimum condition if an advantage can be found according to the designer's judgment. .

In addition, as the constant is increased as described above, the current capacity of one power switching element can be reduced, so that the speed as a switching element of a boost converter circuit used in a large-capacity battery pack such as for an electric vehicle. It is also possible to adopt a FET device which is very fast and relatively easy in parallel connection. Therefore, in the case of the boost converter of the multiphase structure, the industrial use effect can be increased.

In addition, when the parallel operation constant increases as described above, a part of the constant occurs, so that the hardware and the control system can be configured to separate the switching legs of the failed phase from the operation circuit mode and operate as the remaining healthy phase. Boost converters can be configured to improve the operating reliability of the electrical system.

Meanwhile, in the boost converter shown in FIG. 6 or 7, the ripple size of the inductor current increases as the size (inductance) of the inductor is reduced. 9 shows inductor current with decreasing inductance. During the period when the lower switch of the switching leg is turned off (the upper switch is on) due to the reduced inductance, the inductor current passes through zero current and finally becomes the negative polarity current which reverses direction. In the negative inductor current section, as shown in FIG. 10B, when the lower switch and the upper switch are turned off at the same time, the negative inductor current flows through the antiparallel diode of the lower switch. Then, by turning on the lower switch as shown in (c) of FIG. 10, zero voltage switching without turn-on loss of the switch can be implemented.

On the other hand, in order to implement the above zero voltage switching in the full load region, the inductor of the boost type converter is set to a sufficiently small value so that the inductor current is reversed in the off period of the lower switch at the maximum load so that the current becomes a negative polarity. It needs to be selected. However, when the boost converter is controlled by pulse width modulation having a constant switching frequency, the implementation of the zero voltage switching in the full load region causes an inductor current of excessive negative polarity at light load, which is the neck of the boost converter. This is a major cause of lowering the power conversion efficiency.

Therefore, when controlled by pulse width modulation having a constant switching frequency, the boost converter is preferably designed to be zero voltage switched at light load and hard switched at heavy load in consideration of energy conversion efficiency.

On the other hand, zero voltage switching in the full load region without generating excessive negative polarity inductor current at light load in the boost converter can be achieved through pulse width modulation control having a variable switching frequency.

11 is an embodiment of the present invention, the ripple waveform of the inductor current when the switching frequency shown in Figure 11 (a) is low and when the corresponding frequency is increased according to the variable frequency at light load shown in Figure 11 (b) Are compared to each other. Although the average current (load current) of the inductor is the same, as the switching frequency increases, the ripple magnitude of the inductor current decreases, indicating that the magnitude of the negative inductor current decreases. Therefore, the energy conversion efficiency during light load operation of the converter is increased by varying the frequency of pulse width modulation.

FIG. 13 illustrates a correlation between an internal resistance of a lithium-based battery unit cell and a discharge current up to a discharge termination voltage.

As a load resistor that can be varied, the load current and the terminal voltage of the battery cell are measured while increasing the discharge current to obtain a graph as shown in FIG. 13. The voltage shown in the voltmeter in FIG. 13 is the potential difference between two pole terminals of the battery when a discharge current flows in the battery, which indicates the terminal voltage of the battery.

The reason why the battery terminal voltage decreases as the discharge current increases is that a voltage drop due to the internal resistance of the battery occurs. The slope of the straight line in the graph of FIG. 13 is equal to the internal resistance of the battery. In this way, when the discharge current flows, a voltage drop occurs due to the internal resistance of the battery, thereby lowering the terminal voltage of the battery cell.

When the discharge current is 0, there is no voltage drop due to the internal resistance, and the voltage at this time is called the electromotive force of the battery. In the graph of FIG. 13, the terminal voltage when the straight line is extended to meet the voltage V axis is the electromotive force of the storage battery. In the lithium-based storage battery, since the electromotive force after charging is changed depending on the factors related to the charging conditions, it is preferable to measure after the stable period.

If E is the electromotive force of the battery, V is the terminal voltage of the battery during actual discharge, r is the internal resistance of the battery, and I is the discharge current flowing through the battery.

(식 1)

(Equation 1)

Since the battery terminal voltage V is a voltage applied to the load resistance R, the discharge current of the battery I can be expressed as Equation 2 below.

(식 2)

(Equation 2)

Discharge the fully charged battery under test at the rated load until the discharge end voltage is reached, and the accumulated current of the discharge current during the discharge period (in units of Ah) is the healthy state of the battery under test. It corresponds to the maximum discharge amount Ah that can be handled under SOH) conditions. In addition, the magnitude of the discharge current at the end of discharge is proportional to the maximum discharge amount Ah.

In addition, in Equation 2, the electromotive force E corresponds to the terminal voltage (electromotive force) of the battery at full charge, and V corresponds to the discharge end voltage at the end of discharge, so the magnitude of the discharge current at the end of discharge is proportional to the internal resistance component r of the battery. It can be seen that.

Therefore, the maximum discharge amount of the battery under test is proportional to the internal resistance of the battery. If the internal resistance component r of the battery increases due to aging of the battery, the maximum discharge amount decreases proportionally.

14 shows the maximum storage capacity that can be discharged to the maximum based on the trend of the internal resistance and the initial rated capacity Rated AH and RAH according to the increase of the charge / discharge cycle t according to the service life of the battery pack (Stack). It shows the trend of BSCM, Battery Storage Capacity Maximum. When the battery pack (Stack) has passed some stabilization period, the internal resistance increases almost linearly within 50% of the charge / discharge cycle (t), and when the battery ages due to the increase of the charge / discharge cycle (t), the total discharge The maximum possible storage capacity (BSCM) reaches a level of 80% or less (point A), after which the internal resistance also rises sharply, causing the battery to end its service life.

BSCMt ₁ , the maximum discharge capacity of the battery pack that can be discharged at the battery pack at the time t _{1 after the} charge and discharge cycle. (at t = t ₁ ) can be expressed as the first-order function of the internal resistance r as in Equation 3.

(식 3)

(Equation 3)

는 t= t₁ 인 시점에서의 상기 축전지팩(Stack)의 내부 저항값이고,

는 상기 신품 축전지팩(Stack)의 사용 개시 시점의 초기 기준 내부 저항값이다.Where RAH represents the rated capacity (Rated AH) designed by the battery manufacturer, and BSCM _t1 is the charge / discharge cycle (time) t = t ₁ The battery pack at a time point of time is the maximum discharge capacity (Battery Storage Capacity Maximum),

T = t ₁ Internal resistance value of the battery pack at a time point,

Is an initial reference internal resistance value at the start of use of the new battery pack Stack.

The rated AH value of a battery unit cell or a battery pack (Stack) presented by a battery manufacturer varies slightly from one battery to another, so full charge is performed when the battery pack is first used. After that, it is preferable to accurately calculate the initial rated capacity Rated AH and RAH by using the discharge current integration method through the continuous discharge process up to the discharge end voltage, and use the resultant value thereof.

는, 축전지팩(Stack)이 제조사로부터 출하될 시 표시된 내부 저항 기준값으로 사용될 수 있으나 신품 축전지일 경우라도 각 단위 셀마다 ±15%의 오차를 가질 수 있으므로, 사용 개시 시점에서 축전지팩(Stack)을 구성하는 각 단위 셀의 내부 저항을 측정하여 이의 평균값을 축전지팩(Stack)의 초기 기준 내부 저항값으로 결정하도록 하는 것이 바람직하다. 또한

역시 t= t₁ 인 시점에서 각 단위 셀의 내부 저항을 측정하여 이의 평균값을 축전지팩(Stack)의 t₁ 인 시점에서의 내부 저항값으로 결정한다.Also

When the battery pack is shipped from the manufacturer, the battery pack may be used as an internal resistance reference value. However, even when the battery pack is new, the battery pack may have an error of ± 15% for each unit cell. It is preferable to measure the internal resistance of each unit cell to be configured to determine the average value thereof as the initial reference internal resistance value of the battery pack. Also

T = t ₁ The internal resistance of each unit cell is measured at the point of time and the average value thereof is calculated as t ₁ of the battery pack. Determined by the internal resistance value at

K ₁ Is a constant that depends on the pole plate material, thickness or electrolyte of the battery unit constituting the battery unit cell, and furthermore, the manufacturing method. For example, the sealed lead acid battery is about 0.9. Lithium ions and lowering the maximum amount of storage capacity of the Li-Polymer battery has charge-discharge cycles (times), the progress of the number percent and that this response is the internal resistance is known to be changed twice as bar, k _1, depending It will be understood that is 0.5 level.

k _t Is a constant corresponding to the derating factor according to the ambient temperature during charging and discharging, and the battery manufacturer discloses the derating factor in graphs or data sheets.

As shown in Equation 3, the battery storage capacity maximum (BSCM) that the battery pack at the point of time when the charge / discharge cycle (t) is increased is the charge / discharge cycle (t). Therefore, the internal resistance can be measured in real time and calculated from Equation 3 based on this.

On the other hand, in an environment where actual load conditions such as an electric vehicle are used, a full discharge cycle section, which is a pattern in which a battery pack starts to discharge from a fully charged state and completely discharges to a final voltage, displays a charge / discharge state. This can be easily achieved by performing the monitoring algorithm. ₂₎ Maximum storage capacity (BSCM) by the actual load discharge test of the battery pack under test is calculated by integrating the amount of discharge current during this discharge period at the end of the complete discharge cycle section.

That is, the time points t _(i-1) , t _(i) , t _{(i + 1)} , t _{(i + 2)} and t _(n) indicated by dotted lines in FIG. The point at which the complete discharge cycle section ends is indicated. In this case, _{2) the} maximum storage capacity (BSCM) calculated by the integration of the actual load discharge amount and _{1) the} maximum storage capacity calculated arithmetically according to Equation 3, _{4) the} difference (difference ₎ by the characteristic factors of the charge and discharge conditions. To have. Thus, by correcting the above-mentioned ₄₎ difference to the result of _{1) the} maximum storage capacity obtained from Equation 3, a graph of the ₃₎ maximum storage capacity correction value at time t _(i-1 ) is obtained (indicated by a dotted line in FIG. 13). Can be. After full discharge interval of the cycle pattern until t _{(i + 1),} the time obtained for the next (for example, t _(i) ~ t _{(i + 1))} during according to the same manner as the calibration phase of the immediately preceding interval ₅₎ max The storage capacity value is corrected and adopted.

Since the measured values of the internal resistance and the maximum storage capacity (BSCM) change according to the temperature at the time of measurement, it is recommended to measure the ambient temperature of the battery pack at the same time and convert the measured values into standard temperatures. It is essential.

If this correction is repeatedly performed at the end of the section in which the complete discharge cycle pattern is performed, during the period of use during which the charge / discharge cycle increases with the age of the battery pack without the actual load discharge test. A very accurate characteristic curve of the maximum storage capacity (BSCM) can be obtained.

In this method of calculating the maximum storage capacity (BSCM), the temperature reduction that the battery manufacturer presents the internal resistance value calculated by the embedded device 15 without experimentally obtaining all the parameter elements related to the SOC. In consideration of the characteristic data, the correction value is calculated based on the standard temperature, and the maximum storage capacity (BSCM) corresponding to the internal resistance value obtained above is obtained by using the correlation function, and the maximum storage capacity obtained from the correlation function for a predetermined period. If the BSCM is corrected according to a correction method that is primarily obtained, the corrected maximum storage capacity (BSCM) value in all sections in which the charge and discharge cycles of the battery pack are performed can be easily obtained.

In addition, by analyzing the result obtained by integrating the charge and discharge current amount during a certain charge and discharge cycle period, it is possible to know the charged amount up to now, so that the current charged amount is divided by the maximum storage capacity (BSCM) obtained in the above step In consideration of the aging state of the battery pack (Stack) it is possible to accurately calculate the SOC (%) that can know the current state of charge.

The detailed process of calculating the maximum storage capacity (BSCM) as the charge and discharge cycle of the battery pack (Stack) proceeds will be described below.

로 결정한다(S202). 다음 단계로는, 상기 초기 기준 내부 저항값

을 표준온도로 환산한다(S203). 다음 단계로는, t= t₁ 인 시점에서 각 단위 셀의 내부 저항을 측정하여 이의 평균값을 축전지팩(Stack)의 t₁ 인 시점의 내부 저항값

로 결정하고 이를 표준온도로 환산한다(S204). 다음 단계로 실부하 충·방전사이클이 이루어 지는를 판단하여 완전 실부하 구간을 구한다(S205). 상기 단계 S205 에서 실부하 방전전류의 적산에 의해 구해진 ₂₎최대 저장 용량(BSCM)을 산출하고 이를 표준온도로 환산한다(S206). 다음 단계로 산술적으로 ₁₎최대 저장 용량을 식 3에 의해 산출하고 단계 S206 에서 구한 값과의 차를 구한다(S207). 다음으로는 상기에서 구해진 차를 이용하여 ₃₎최대 저장 용량을 보정한다(S208). 끝으로 상기 단계에서 보정된 ₃₎최대 저장 용량으로부터 노화가 진행된 상태에 따른 SOC(%)를 산출한다(S209).First, at the time of starting use for the first time, the correct initial rated capacity Rated AH and RAH is calculated (S201). In the next step, the internal resistance of each unit cell constituting the battery pack is measured at the time of starting use, and the average value thereof is determined based on the initial reference internal resistance value of the battery pack.

Determine (S202). Next step, the initial reference internal resistance value

Convert to the standard temperature (S203). The next step is t = t ₁ The internal resistance of each unit cell is measured at the point of time and the average value thereof is calculated as t ₁ of the battery pack. Internal resistance value at

Determine and convert it to the standard temperature (S204). In the next step, it is determined whether a real load charging / discharging cycle is performed to obtain a complete actual load section (S205). In step S205, _{2) the} maximum storage capacity BSCM obtained by integration of the actual load discharge current is calculated and converted into a standard temperature (S206). In the next step, arithmetic _{1) the} maximum storage capacity is calculated by the equation 3 and the difference with the value obtained in step S206 is obtained (S207). Next, _{3) the} maximum storage capacity is corrected using the difference obtained above (S208). Finally, the SOC (%) of the aging progressed is calculated from the ₃₎ maximum storage capacity corrected in the above step (S209).

Since SOC (%) obtained above is the value converted into standard temperature, when SOC (%) is needed in actual use temperature conditions, it can be made into the value of a real use temperature condition using the conversion factor adopted by step S206.

The present invention is not limited to the above embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

The technical problem solving method and embodiments of the present invention can be applied to the stationary battery equipment for emergency power of various industrial facilities as well as cycle service storage battery system such as an electric vehicle by applying only equal or equivalent modifications.

In addition, by measuring the equivalent circuit component values such as internal resistance correlated with the aging state (SOH) of the battery, and continuously monitoring the charge and discharge (use) amount history such as charge and discharge current voltage, the charge remaining capacity (SOC) The ability to accurately measure remaining capacity (SOC) based on internal resistance and cell temperature correlated to) can not only accurately determine the remaining mileage of electric vehicles and electric bicycles, which are already proposed. In addition, the present invention may be applied as a means for determining a charge remaining capacity (SOC) of various industrial storage battery facilities.

1 is a block diagram of the built-in charge and discharge control and BMS function of an electric vehicle battery pack.

2 is a block diagram of a BMS circuit and a charge / discharge circuit of a battery pack according to an embodiment of the present invention.

3 is a block diagram of a BMS circuit and a charge / discharge circuit of a battery pack according to still another embodiment;

Figure 4 is an embodiment of the measurement current generating means of the present invention.

Figure 5 is an example of the operation waveform by the measurement current generating means of the present invention.

Figure 6 is a preferred embodiment of the boost converter of the present invention.

Figure 7 is another preferred embodiment of the boost converter of the present invention.

8 is an example of an operating waveform of an individual inductor current and a stack output current by a boost converter.

9 is an operation waveform of the inductor current with decreasing the inductor of the boost converter.

10 is a waveform of inductor current according to the operation of the switching element of the boost converter.

11 is a ripple waveform of the inductor current during the variable switching of the boost converter.

12 is a detailed block diagram of a measurement control module according to an embodiment of the present invention.

FIG. 13 is a graph of correlation between discharge resistance up to discharge termination voltage and internal resistance of a storage unit cell; FIG.

FIG. 14 is a graph showing an increase in internal resistance and a decrease in maximum storage capacity (BSCM) as a result of charge and discharge cycles of a battery pack. FIG.

Claims (17)

In the device for controlling and managing a battery pack (Stack) for supplying the DC power of the electric system or emergency power supply of the electric vehicle, Output current sensing means for sensing a charge / discharge current or a measurement current signal of a battery pack; A boost converter having a multi-phase structure for increasing an output voltage of a battery pack to obtain a high DC voltage required by an electrical system; Monitoring control means for monitoring and analyzing an abnormal (abnormal) state of the aging state or the charge / discharge state of the battery pack; A gate blocking means for stopping the current flow of the switching element or the disconnecting switch of the boost type converter when an abnormality of the battery pack is sensed or predicted in the monitoring control means; And And a switch control means for controlling the switching element of the boost type converter in association with the gate blocking means. The method of claim 1, And a cell selecting means for sequentially connecting the output terminals of the unit cells of the battery pack to the supervisory control means. The method of claim 1, The battery pack further comprising a signal selecting means (21) for sequentially connecting the output signal of the measurement control module groups (21a ~ 21n) for measuring the characteristics of each unit cell in the monitoring and control means of the storage battery pack (Stack) ( Stack device. The method of claim 1, And a cell equalization control means for measuring the unit cell voltages and controlling the unit cell to be uniform when the voltage is higher than the voltage of other cells or higher than the maximum allowable voltage. The method according to any one of claims 1 to 4, And a measurement current generating means for generating a measurement current signal required for measuring the internal resistance or the internal impedance of the battery pack. The method of claim 5, A battery pack device, characterized in that for measuring internal resistance or internal impedance of each unit battery cell by measuring the internal impedance voltage detected in each unit battery cell by the measurement current flowing by the measurement current generating means. The method according to any one of claims 1 to 4, The monitoring control means, When an abnormality is detected or predicted by calculating and analyzing the characteristic elements of each unit cell correlated with the abnormality of the battery pack from the charge / discharge current obtained from the current sensing means and the output signal of the interface circuit. A battery pack device including an embedded device that preferentially generates a blocking signal. The method of claim 7, wherein The embedded device, A battery pack having a memory means having a charge / discharge frequency (cycle), a charge / discharge history, an internal resistance or an internal impedance value, and a corrected maximum storage capacity (BSCM) according to a charge / discharge cycle of the battery pack. Stack device. In the configuration of the measurement current generating means necessary for measuring the internal impedance or the internal resistance, which is an element that monitors the aging of the battery pack or the progress of the life of the battery pack. Measuring current generating means, An inductor connected to a lead terminal of a battery system (pack); A switching leg of a full bridge comprising two switching elements; Battery pack (Stack) device, characterized in that consisting of. The method of claim 9, A battery pack device, characterized in that the output frequency of the measuring current generating means is controlled by receiving a frequency signal from an embedded device that calculates a characteristic element of each unit cell. The method of claim 1, The boost converter, A battery pack device characterized in that one switching switch and two switching elements are connected in a multi-phase parallel form in which a switching leg of a bridge structure connected in series in a polarity direction is formed. The method of claim 11, A negative current (-) terminal of the diode is connected to the capacitor in the switching leg of the boost converter, the other terminal of the capacitor is connected to the negative terminal of the battery pack (Stack), and a current path circuit having a resistance connected in parallel to the capacitor. Battery pack device, characterized in that configured as a bridge structure including more. In order to boost the output voltage of a battery pack, in the control of a boost converter in which a single switching switch and two switching elements are connected in series with a bridge structure in a bridge structure connected in series in a polarity direction. , A method for controlling a boost type converter of a battery pack (Stack), characterized in that the switching legs of the two switching elements of each phase are controlled by pulse width modulation so as to each have a relative phase difference of (360 degrees / constant). The method of claim 13, The pulse width modulation is, A step-up converter control method for a battery pack (Stack) characterized in that it is operated by a pulse width modulation having a constant switching frequency of zero voltage switching at light load, and hard switching at heavy load. The method of claim 13, The pulse width modulation is, A step-up converter control method for a battery pack (Stack) characterized in that the operation is operated by pulse width modulation characterized in that the switching frequency is changed so that zero voltage switching is implemented in the full load region. The method of claim 13, The boost type of the battery pack (Stack) characterized in that the cut-off switch of the boost converter is switched off in a section in which the current flowing in the inductor flows in the negative (-) direction, so that the boost converter stops or malfunctions. How to control the converter. In the method for obtaining the state of charge (SOC) according to the healthy state of the battery pack, Measure the internal resistance of each unit cell at the start of use and determine the average

Determining as (S202), The initial reference internal resistance value

Converting to a standard temperature (S203). The internal resistance of each unit cell is measured at the point where measurement is required, and the average value thereof is measured.

Determine and convert it to the standard temperature (S204). Step (S205) to determine the section in which the real load charge and discharge cycle is made up to the discharge end voltage. ₂₎ calculating the maximum storage capacity (BSCM) obtained by integrating the actual load discharge current in step S205 and converting it to a standard temperature (S206). Arithmetic ₁₎ calculating the maximum storage capacity by the equation 3 and calculating the difference from the value obtained in the above step (S207). ₃₎ correcting the maximum storage capacity using the difference obtained above; Method for calculating the SOC (%) of the battery pack (Stack) (pack) comprising a.

Images