JP5736591B2 - CHARGE CONTROL DEVICE AND CHARGE CONTROL METHOD IN THE CHARGE CONTROL DEVICE - Google Patents

Description

  The present invention relates to a charge control device that collectively charges a battery module in which a plurality of cell batteries (secondary batteries) are connected in series, and in particular, is used to adjust and balance the charge voltage of each cell battery. When measuring the voltage across the bypass unit (impedance circuit selectively connected in parallel to the cell battery) to detect the cell battery voltage, a bypass current flows through the voltage measurement line connecting the cell battery and the bypass unit. The present invention relates to a charge control device that can detect an accurate cell voltage value even when a voltage drop occurs, and a charge control method in the charge control device.

  In a charging control device that controls charging to a battery module configured by connecting a plurality of cell batteries in series, the battery voltage of each cell battery is detected (measured), and the charging voltage between the cell batteries is adjusted. It is configured to be balanced (see, for example, Patent Documents 1, 2, and 3).

  When battery cells connected in series are collectively charged by a battery charger (constant voltage DC power supply device or constant current DC power supply device), if the battery capacity of the cell battery is unbalanced, The cell battery having a small capacity is fully charged first, and the charging operation is completed without sufficiently charging the cell battery having a large battery capacity. That is, charging is stopped in a state where the battery module cannot be fully charged as a whole. In order to avoid this, when the battery voltage (charging voltage) of each cell battery is detected at the time of charging, and the battery voltage is unbalanced, the bypass unit is selectively connected in parallel to the cell battery. (Impedance circuit) is used to equalize the charging voltages of the cell batteries.

  FIG. 3 is a diagram illustrating a configuration example of a conventional charge control device. 3, cell batteries 1, 2,..., N are a plurality of cell batteries connected in series, and charging from a battery charging device (constant voltage DC power supply device or constant current DC power supply device) 21. It is a cell battery that is charged at a time by the current Ic. In addition, when charging the battery cells 21, 2,..., N from the battery charger 21, a method of performing constant current charging (CC charging), a method of performing constant voltage charging (CV charging), There are various charging methods such as a method in which constant current charging (CC charging) is performed in the initial stage of charging and constant voltage charging (CV charging) is performed in a state where charging has progressed to some extent.

  In the charge control device 11A shown in FIG. 3, the positive (+) pole side of each of the cell batteries 1, 2,..., N is connected to the input terminals A1, A2, ..., An and voltage measurement lines La1, La2. ,..., Lan are connected to the input terminals E1, E2,. In addition, each of the negative (−) pole sides of the cell batteries 1, 2,..., N passes through the input terminals B1, B2,..., Bn and the voltage measurement lines Lb1, Lb2,. , Gn are connected to the input terminals G1, G2,.

  Overcurrent protection fuses F1, F2,..., Fn are inserted into the voltage measurement lines La1, La2,. Further, each of the bypass units 19-1, 19-2,..., 19-n passes through the voltage measurement lines La1, La2,..., Lan and the voltage measurement lines Lb1, Lb2,. It is connected in parallel to each cell battery 1, 2, ..., n. The bypass units 19-1, 19-2,..., 19-n include bypass switches SW1, SW2,..., SWn constituted by semiconductor switches and the like, and bypass resistors R1, R2,. It is composed of a series circuit with Rn.

  The voltage detector 13 is a voltage detector for detecting the cell voltages Vc1, Vc2,..., Vcn of the respective cell batteries 1, 2,. The cell voltages Vc1, Vc2,..., Vcn are detected by measuring terminal voltages Va1, Va2,.

  As described above, in the charge control device 11A shown in FIG. 3, a plurality of circuits having the same configuration such as a voltage measurement line and a bypass unit are provided in parallel corresponding to each of the cell batteries 1, 2,. It has been. For this reason, in the following description, the part of the circuit corresponding to the cell battery 1 will be described, but the same applies to the circuits corresponding to the other cell batteries 2,.

  One end of the voltage measurement line La1 corresponding to the cell battery 1 is connected to the positive (+) pole side of the cell battery 1 through the terminal A1, and the other end is a measurement line impedance equivalent circuit which is an impedance equivalent circuit of the voltage measurement line La1. It is connected to the terminal C1 of the bypass unit 19-1 via 18-1. The terminal C1 is connected to the input terminal E1 of the voltage detection unit 13. One end of the voltage measurement line Lb1 is connected to the negative (−) pole side of the cell battery 1 through the terminal B1, and the other end is connected to the terminal D1 of the bypass unit 19-1. The terminal D1 is connected to the input terminal G1 of the voltage detection unit 13.

  A measurement line impedance equivalent circuit 18-1 of the voltage measurement line La1 includes an overcurrent protection fuse F1 (internal resistance rf1) and a wiring path of the voltage measurement line La1 (for example, the input terminal A1 and the terminals of the bypass unit 19-1). (A wiring pattern of the printed wiring board between C1) and the impedance component r1.

  The bypass unit 19-1 includes a series circuit including a bypass switch SW1 and a bypass resistor R1. One end (terminal C 1) of the bypass unit 19-1 is connected to one end of the measurement line impedance equivalent circuit 18-1 and also connected to the input terminal E 1 of the voltage detection unit 13. The other end (terminal D1) of the bypass unit 19-1 is connected to the negative (−) electrode side of the cell battery 1 through the input terminal B1, and is connected to the input terminal G1 of the voltage detection unit 13.

  The voltage detection unit 13 is a voltage detection unit for detecting the battery voltage Vc1 of the cell battery 1, and detects the cell voltage Vc1 by measuring the terminal voltage Va1 at both ends of the bypass unit 19-1. Yes.

  In the above configuration, when the cell voltage 1 of the cell battery 1 is larger than a preset threshold voltage during the charging operation of the cell battery 1 (or larger than other cell voltages Vc2,..., Vcn). In the case), the bypass switch SW1 is turned on (conducted), a part of the charging current Ic flowing through the cell battery 1 is bypassed by the bypass resistor R1 as the bypass current Ib1, and the charging speed to the cell battery 1 is delayed. On the contrary, when the cell voltage Vc1 of the cell battery 1 is smaller than a preset threshold voltage (or smaller than other cell voltages Vc2,..., Vcn), the bypass switch SW1 is turned off. (Non-conduction) and normal charging.

  The configuration and operation of the circuit corresponding to the cell battery 1 have been described above, but the same applies to the circuits corresponding to the other cell batteries 2,. That is, the cell voltage Vc1, Vc2,..., Vcn of each cell battery 1, 2,..., N is detected by the voltage detection unit 13, and the bypass units 19-1, 19- according to the detection result. 2,..., 19-n are selected and ON / OFF controlled so that a bypass current flows to a cell battery having a high battery voltage (charge voltage). Thereby, when the cell batteries 1, 2,..., N are collectively charged by the battery charger 21, the charging voltage of the cell batteries 1, 2,. .

JP 2004-245743 A JP 2002-291167 A JP 2001-178008 A

  As described above, in the charge control device 11A that collectively charges a battery module in which a plurality of cell batteries are connected in series, the cell voltages Vc1, Vc2,. Vcn is detected, and the bypass units 19-1, 19-2,..., 19-n are ON / OFF controlled based on the detection result. Thereby, control is performed so that the charging voltages of the cell batteries 1, 2,.

  However, in the conventional charge control device 11A, for example, taking the cell battery 1 as an example, the cell voltage Vc1 of the cell battery 1 is detected by measuring the terminal voltage Va1 across the bypass unit 19-1. ing. Therefore, in a state where the bypass switch SW1 in the bypass unit 19-1 is ON (conductive), the bypass current Ib1 flows through the voltage measurement line La1, and the components on the voltage measurement line La1 are used for the bypass current Ib1. There is a problem that a voltage drop occurs due to an impedance component (for example, the fuse F1) or a wiring pattern, and it becomes difficult to accurately detect the cell voltage Vc1. This situation is the same for the other cell batteries 2,. For this reason, it is difficult to balance the charging voltages of the respective cell batteries 1, 2,.

  This invention is made | formed in view of such a situation, and the objective of this invention is when measuring the terminal voltage of the both ends of the bypass part selectively connected in parallel with a cell battery, and detecting a cell voltage. A charge control device capable of detecting an accurate cell voltage value even when a voltage drop occurs due to a bypass current flowing in a voltage measurement line connecting the cell battery and the bypass unit, and charging in the charge control device It is to provide a control method.

The present invention has been made to solve the above problems, and the charge control device of the present invention is a charge control device that charges a plurality of cell batteries connected in series by a battery charger. An impedance circuit is provided in parallel for each cell battery, and a wiring from the cell battery to the impedance circuit corresponding to the cell battery is used as a voltage measurement line, and a fuse is connected to the wiring of the voltage measurement line. It is provided for each battery, and is configured such that a common wiring section is not generated between the voltage measurement lines of each cell battery in calculating the voltage of each cell battery, so that the cell between the wiring from the wiring and the other cell batteries to the impedance circuit corresponding to the battery until the impedance circuit corresponding to the other cell batteries The bypass unit is configured so as not to generate a common impedance with each other, and selectively connects or disconnects an impedance circuit provided in parallel to the cell battery, and the bypass unit includes a terminal voltage of the bypass unit. From the voltage detection unit for detecting a closed-circuit terminal voltage when conducting, the closed-circuit terminal voltage, an impedance value of a voltage measurement line connecting the cell battery and the bypass unit, and an impedance value of the bypass unit, the cell battery A cell voltage calculation unit for calculating the cell voltage of the cell.

  Moreover, this invention memorize | stores the impedance value of the voltage measurement line which connects each said cell battery and the said bypass part corresponding to this cell battery, and the impedance value of the said bypass part in the charge control apparatus as described above. An impedance storage unit, the cell voltage calculation unit calculates a bypass current flowing in the bypass unit based on the closed-circuit terminal voltage and the impedance value of the bypass unit when the bypass unit is conducted, A correction value is calculated based on a bypass current and an impedance value of the voltage measurement line, and a cell voltage of a cell battery is calculated based on the closed-circuit terminal voltage and the correction value.

  Further, the present invention provides the charge control device according to the above, wherein the cell voltage calculation unit calculates the bypass current by dividing the closed-circuit terminal voltage by an impedance value of the bypass unit, and the bypass current and The correction value is calculated by multiplying the impedance value of the voltage measurement line, and the cell voltage is calculated by adding the closed terminal voltage and the correction value.

  The charging control device according to the present invention further includes a bypass control unit that makes the bypass unit conductive or non-conductive based on the cell voltage calculated by the cell voltage calculation unit. The control unit makes the bypass unit non-conductive when the calculated cell voltage is insufficient with respect to a predetermined threshold voltage set in advance, and when the calculated cell voltage has reached, the bypass The part is made conductive.

Further, the charge control method of the present invention is a charge control method in a charge control device that charges a plurality of cell batteries connected in series at once by a battery charging device, and by a control unit in the charge control device, Impedance circuits are provided in parallel for each cell battery, and the wiring from the cell battery to the impedance circuit corresponding to the cell battery is used as a voltage measurement line, and a fuse is connected to the wiring of the voltage measurement line. Each cell battery is configured so that a common wiring section does not occur between the voltage measurement lines of each cell battery when calculating the voltage of each cell battery. the wiring from the wiring and the other cell batteries to the impedance circuit corresponding to the impedance circuit corresponding to the other cells battery During is configured so as not to cause the common impedance with each other, a bypass procedure for selectively conductive or non-conductive impedance circuit provided in parallel to the cell battery, the terminal voltage of the impedance circuit, said A voltage detection procedure for detecting a closed-circuit terminal voltage when the impedance circuit is conducted by a voltage detection unit, the closed-circuit terminal voltage, an impedance value of a voltage measurement line connecting the cell battery and the impedance circuit, and the impedance circuit A cell voltage calculation procedure for calculating a terminal voltage of the cell battery from the impedance value is performed.

In the charging control device of the present invention, the impedance value of the bypass unit and the impedance values of the components and wiring patterns of the voltage measurement line are stored in advance, and the voltage detection value detected by the voltage detection unit and the impedance value of the bypass unit The bypass current value flowing through the bypass unit is calculated based on the above, the voltage correction value is calculated based on the bypass current value and the impedance value of the voltage measurement line, and the voltage detection value detected by the voltage detection unit is corrected.
As a result, when the cell voltage is detected by measuring the terminal voltage at both ends of the bypass unit selectively connected in parallel to the cell battery, the bypass current flows through the voltage measurement line connecting the cell battery and the bypass unit. Even when a voltage drop occurs, an accurate cell voltage value can be detected.

It is a figure which shows the structure of the charge control apparatus concerning embodiment of this invention. It is a flowchart which shows the flow of a process in the charge control apparatus shown in FIG. It is a figure which shows the structure of the conventional charge control apparatus.

  FIG. 1 is a diagram showing a configuration of a charging control apparatus according to an embodiment of the present invention.

  The charge control device 11 of the present invention shown in FIG. 1 is different from the conventional charge control device 11A shown in FIG. 3 in that the control unit 12 and the bypass control unit in the charge control device 11 shown in FIG. 14, a cell voltage calculation unit 15, and a charging device control unit 17 are newly added. Other configurations are the same as those of the charging control device 11A shown in FIG. For this reason, the same code | symbol is attached | subjected to the same component. Further, FIG. 1 shows an example in which the bypass current Ib1 flows only to the cell battery 1.

  In FIG. 1, cell batteries 1, 2,..., N are n secondary batteries (cell batteries) connected in series, and are collectively charged by a charging current Ic flowing from the battery charger 21. It is a battery module.

  The positive (+) pole sides of the cell batteries 1, 2,..., N are connected to input terminals A1, A2,..., An (generically referred to as input terminal A) of the charging control device 11, respectively. The Further, the input terminals A1, A2,..., An are voltage measurement lines La1, La2,..., Lan (including measurement line impedance equivalent circuits 18-1, 18-2,..., 18-n). To the input terminals E1, E2,..., En (generically referred to as the input terminal E) of the voltage detection unit 13. Further, the negative (−) pole side of each of the cell batteries 1, 2,..., N is input terminals B1, B2,..., Bn (collectively referred to as input terminal B) and voltage measurement lines Lb1, .., Lbn (generically referred to as voltage measurement line Lb), and connected to input terminals G1, G2,..., Gn (generically referred to as input terminal G) of the voltage detector 13 through Lb2,.

  When the charging control device 11 charges each cell battery 1, 2,..., N, the cell voltages Vc1, Vc2,. When the cell voltages Vc1, Vc2,..., Vcn are unbalanced and are detected, the cell battery to be corrected is corrected. ON (conductive) / OFF (non-conductive) control of bypass sections 19-1, 19-2,... 19-n (collectively referred to as bypass section 19) corresponding to 1, 2,. Do.

  Moreover, the charging control apparatus 11 also controls the battery charging apparatus 21 by the charging apparatus control part 17 mentioned later. For example, at the time of batch charging to the cell batteries 1, 2,..., N, the respective cell voltages Vc1, Vc2,. , N is fully charged, charging from the battery charger 21 to the cell batteries 1, 2,..., N is stopped in order to prevent overcharging.

  In the example shown in FIG. 1, the discharge circuit for supplying power from the cell batteries 1, 2,..., N to the load is not directly related to the present invention, and is shown for ease of viewing the drawing. Although not shown, as a matter of course, a discharge circuit and a discharge control device (both not shown) for supplying power from the cell batteries 1, 2,..., N to the load are provided. For example, during the discharge operation from the cell batteries 1, 2,..., N to the load, the battery voltage of any cell battery reaches a predetermined lower limit value (threshold voltage for preventing overdischarge). In such a case, the discharge from the cell batteries 1, 2,..., N to the load is stopped.

  In the charge control device 11 of the present embodiment shown in FIG. 1, the control unit 12 controls the entire processing unit in the charge control device 11 in an integrated manner, and realizes functions required for the charge control device 11. It is a control part for. The voltage detector 13 detects the cell voltages Vc1, Vc2,..., Vcn of the cell batteries 1, 2,..., N, so that the bypass units 19-1, 19-2,. Terminal voltages Va1, Va2,..., Va3 (collectively referred to as Va) at both ends of n are measured.

  Measurement line impedance equivalent circuits 18-1, 18-2,..., 18-n (measurement line impedance equivalent circuits) on voltage measurement lines La1, La2,. , Fn (internal resistances rf1, rf2,..., Rfn) provided corresponding to the cell batteries 1, 2,. And an equivalent circuit represented by a series circuit of impedance components r1, r2,..., Rn of a wiring path (a wiring pattern on a printed wiring board, etc.). The fuses F1, F2,..., Fn are collectively referred to as the fuse F, and the internal resistances rf1, rf2,..., Rfn are collectively referred to as the internal resistance rf, and the impedance components r1, r2,. rn is generically referred to as an impedance component r.

  For example, one end of the measurement line impedance equivalent circuit 18-1 on the voltage measurement line La1 is connected to the positive (+) pole side of the cell battery 1 through the input terminal A1. The other end of the measurement line impedance equivalent circuit 18-1 is connected to one end (terminal C 1) of the bypass unit 19-1 and to the input terminal E 1 of the voltage detection unit 13. The measurement line impedance equivalent circuit 18-1 includes an overcurrent protection fuse F1 (internal resistance rf1) and a wiring path (for example, between the input terminal A1 and the terminal C1 of the bypass unit 19-1) of the voltage measurement line La1. Of the wiring pattern on the printed wiring board) and the impedance component r1.

  Note that the impedance component due to the wiring pattern is also connected to the negative (−) pole side of the cell battery 1 via the input terminal B and also to the voltage measurement line Lb1 connected to the bypass unit 19-1 and the connection terminal D1. Although present, the impedance component of the voltage measurement line Lb1 can be considered to be included in the impedance component r1 of the voltage measurement line La1.

  The bypass units 19-1, 19-2,..., 19-n include bypass switches SW1, SW2,..., SWn (generically referred to as bypass switches SW) constituted by semiconductor switches and the like, and bypass resistors. Rn, R2,..., Rn (generically referred to as bypass resistor R). One terminal C1, C2,..., Cn (generically referred to as terminal C) of the bypass units 19-1, 19-2,..., 19-n is input terminals E1, E2 of the voltage detection unit 13. ,..., En. The other terminals D1, D2,..., Dn (generically referred to as terminal D) of the bypass units 19-1, 19-2,..., 19-n are input terminals G1 of the voltage detection unit 13. , G2,..., Gn.

  For example, the bypass unit 19-1 provided corresponding to the cell battery 1 is configured by a series circuit of a bypass switch SW1 and a bypass resistor R1. One end (terminal C1) of the bypass unit 19-1 is connected to one end of the measurement line impedance equivalent circuit 18-1, and is also connected to the input terminal E1 of the voltage detection unit 13. Further, the other end (terminal D <b> 1) of the bypass unit 19-1 is connected to the input terminal B connected to the negative (−) pole side of the cell battery 1 and to the input terminal G <b> 1 of the voltage detection unit 13. .

  That is, one end (terminal C) of the bypass unit 19 corresponding to each cell battery 1, 2,..., N is connected to one end of the measurement line impedance equivalent circuit 18 and the input terminal E of the voltage detection unit 13. Connected to. The other end (terminal D) of the bypass unit 19 is connected to the input terminal B connected to the negative (−) pole side of the cell batteries 1, 2,. G is connected.

  The bypass control unit 14 is a cell voltage Vc1, Vc2,..., Vcn (more precisely, the terminal voltage Va of the bypass unit 19 or the cell voltage Vc obtained by correcting the terminal voltage Va by the cell voltage calculation unit 15 described later). Based on the value, the ON (conducting) or OFF (non-conducting) operation in the bypass unit 19 is determined for each cell battery 1, 2,..., N. Based on this determination result, ON (conducting) / OFF (non-conducting) of bypass switches SW1, SW2,..., SWn (generically referred to as bypass switch SW) in the bypass unit 19 are controlled. That is, in this bypass control unit 14, when the cell voltages Vc1, Vc2,..., Vcn are unbalanced, the cell batteries 1, 2,. .. ON / OFF control of the bypass switch SW in each bypass unit 19 corresponding to n is performed.

  For example, when the cell voltage Vc1 of the cell battery 1 is larger than a preset threshold voltage during the charging operation (or larger than other cell voltages Vc2,..., Vcn), the bypass switch SW1 is turned on, a part of the charging current Ic flowing through the cell battery 1 is bypassed to the bypass resistor R1 as a bypass current Ib1, and the charging speed of the cell battery 1 is delayed. On the other hand, when the cell voltage Vc1 of the cell battery 1 is smaller than a preset threshold voltage (or smaller than other cell voltages Vc1, Vc2,..., Vcn), the bypass switch SW1. Is turned off (non-conducting).

  In the example shown in FIG. 1, only the bypass switch SW1 is ON, and the bypass switches SW2,..., SWn are OFF. Therefore, only the bypass current Ib1 flows through the bypass unit 19-1, and bypass currents Ib2,..., Ibn (not shown) do not flow through the bypass units 19-2,. Indicates the state. The bypass currents Ib1, Ib2,..., Ibn flowing through the bypass units 19-1, 19-2,.

  When the bypass switch SW is in the ON state, the cell voltage calculation unit 15 is based on the cell voltage (terminal voltage of the bypass unit 19) Va detected at the input terminals E and G of the voltage detection unit 13, and the bypass unit 19 A bypass current Ib flowing through the bypass resistor R is calculated, a correction voltage ΔVf is calculated based on the bypass current Ib and the impedance value Z of the measurement line impedance equivalent circuit 18 of the voltage measurement line La, and the corrected cell This is a processing unit for calculating the voltage Vc (Vc = Va + ΔVf).

  For example, when the bypass switch SW1 is in the ON state, the inside of the bypass unit 19-1 is based on the cell voltage (terminal voltage of the bypass unit 19-1) Va1 detected at the input terminals E1 and G1 of the voltage detection unit 13. The bypass current Ib1 flowing through the bypass resistor R1 is calculated, and the correction voltage ΔVf1 is calculated and corrected based on the bypass current Ib1 and the impedance value Z1 (rf1 + r1) of the measurement line impedance equivalent circuit 18-1. Cell voltage Vc1 (Vc1 = Va1 + ΔVf1) is calculated.

  Moreover, the impedance memory | storage part 16 is the components (for example, internal resistance rf of the fuse F) which exist in the voltage measurement lines La1, La2, ..., Lan, the impedance value of the impedance component r which exists on a wiring pattern, and those Is recorded in advance.

  The charge control device 11 includes an input device (for example, an operation switch such as a push button switch) for instructing a charge control operation for the cell battery, a display device for displaying a detection result, and a charge control operation. It is assumed that a communication device (none of which is displayed) for outputting the result (for example, the charging voltage of each cell battery) to the outside by communication is installed.

  In the charge control device 11 having the above configuration, the cell voltage calculation unit 15 corrects the voltage drop value generated in the voltage measurement line La due to the bypass current Ib flowing in the bypass unit 19, and the cell batteries 1, 2,. Accurate cell voltages Vc1, Vc2,..., Vcn are detected. Hereinafter, the correction operation will be described. In the example described below, the bypass current Ib1 flows only in the cell battery 1 in FIG. 1, and the bypass currents Ib2 and Ibn do not flow in the cell battery 2 and the cell battery n in FIG.

  First, in the charge control device 11, components existing in the voltage measurement line La in advance, for example, internal resistances rf1, rf2,..., Rfn of fuses, impedance components r1, r2,. , Rn are measured in advance and recorded in the impedance storage unit 16 together with the total impedance values Z1, Z2,.

  Subsequently, the voltage detection unit 13 detects (measures) terminal voltages Va1, Va2,..., Van at both ends of the bypass units 19-1, 19-2,.

For example, when the bypass unit 19-1 is turned on by the bypass control unit 14 (bypass switch SW1 is turned on), the bypass current Ib1 is derived from the cell voltage of the cell battery 1 (terminal voltage of the bypass unit 19-1) Va1. Is calculated from the resistance value of the bypass resistor R1 of the bypass unit 19-1.
The current value of the bypass current Ib1 is calculated by “Ib1 = V1 / R1”.

Next, a voltage drop value ΔVr1 generated by the voltage measurement line La1 is calculated based on the current value of the bypass current Ib1.
This voltage drop value ΔVr1 is calculated by “ΔVr1 = Ib1 × Z1”.

Subsequently, the detected cell voltage (terminal voltage of the bypass unit 19-1) Va1 of the cell battery 1 and the calculated voltage drop value ΔVr1 are added together.
Thereby, the true cell voltage Vc1 can be calculated by “Vc1 = Va1 + ΔVr1”.

  Further, when the bypass operation is not performed, for example, when it is considered that the bypass operation is not performed in the cell battery 2 and the cell battery n, the voltage drops (ΔVr2 and ΔVrn) do not occur because the bypass currents Ib2 and Ibn do not flow. Therefore, the correction by the cell voltage calculation unit 15 is not performed. In this case, the cell voltage Vc2 of the cell battery 2 without the bypass operation is such that the cell voltage (terminal voltage of the bypass unit 19-2) Va2 detected by the voltage detection unit 13 becomes the true cell voltage Vc2 (Vc2 = Va2). . Similarly, the cell voltage Vcn of the cell battery n without the bypass operation is the cell voltage (terminal voltage of the bypass unit 19-n) Van detected by the voltage detection unit 13 becomes the true cell voltage Vcn (Vcn = Van). .

  As described above, the example in which the voltage drop value ΔVr1 is calculated and corrected when the bypass unit 19-1 is turned on with respect to the cell battery 1 has been described, but each of the other cell batteries 2,. Even when the corresponding bypass units 19-2 to 19-n are turned on, the correction is performed by the same method.

  FIG. 2 is a flowchart showing the flow of processing in the charging control apparatus of the present invention, and shows the flow of cell voltage correction processing in the above-described charging control apparatus 11 in a flowchart. Hereinafter, the processing flow will be described with reference to the flowchart shown in FIG.

  Referring to FIG. 2 (and FIG. 1), in the initial state after the start of charging, all bypass switches SW in each bypass unit 19 are in the OFF state by the control operation of bypass control unit 14 ( Step S1).

  In this state, the voltage detection unit 13 inputs the cell voltages (terminal voltages of the bypass unit 19) of the cell batteries 1, 2,..., N from the input terminals E and G, and the terminal voltage of the bypass unit 19 Are detected as cell voltages Va1, Va2,..., Van (step S2).

  Subsequently, the bypass control unit 14 determines the operating condition of the bypass unit 19 corresponding to each cell battery 1, 2,..., N (step S3). For example, when the cell voltage of the cell battery 1 (terminal voltage of the bypass unit 19-1) Va1 is higher than a preset threshold voltage (or higher than the cell voltage of another cell battery), It is determined that the bypass switch SW1 of the bypass unit 19-1 corresponding to the cell battery 1 is turned on. This determination is performed on the cell voltages (terminal voltages of the bypass unit 19) Va1, Va2,..., Van of the respective cell batteries 1, 2,.

  That is, for the cell battery m (m = 1 to n) determined to satisfy the operating condition of the bypass unit 19 (step S3: Yes), the bypass unit 19-m corresponding to the cell battery m is turned on. (Step S4).

  Subsequently, the voltage detection unit 13 detects the cell voltage (terminal voltage of the bypass unit 19-m) Vam of the cell battery m with the bypass unit 19-m turned on (step S5). Then, the cell voltage calculation unit 15 calculates the bypass current Ibm from the cell voltage (terminal voltage of the bypass unit 19) Vam when the bypass unit 19-m is turned on (step S6). That is, the cell voltage calculation unit 15 calculates the current value of the bypass current Ibm based on the resistance value of the bypass resistor Rm for the cell battery m with the bypass unit 19-m turned on. For example, when the bypass unit 19-1 of the cell battery 1 is turned on, the current value of the bypass current Ib1 is calculated based on the impedance value (resistance value) of the bypass resistor R1. The current value of the bypass current Ib1 is calculated by “Ib1 = Va1 / R1”.

  Further, the cell voltage calculation unit 15 calculates the voltage drop value ΔVrm generated by the voltage measurement line Lam based on the current value of the bypass current Ibm (step S7). This voltage drop value ΔVrm is calculated by “ΔVrm = Ibm × Zm”. For example, when the bypass unit 19-1 of the cell battery 1 is turned on, the voltage drop value ΔVr1 generated by the voltage measurement line La1 is calculated based on the current value of the bypass current Ib1. This voltage drop value ΔVr1 is calculated by “ΔVr1 = Ib1 × Z1”. Here, “Z1 = rf1 + r1”.

  Subsequently, the cell voltage calculation unit 15 adds the detected cell voltage (terminal voltage of the bypass unit 19-m) Vam and the calculated voltage drop value ΔVrm to correct the detected cell voltage Vam (step S8). Thereby, the true cell voltage Vcm can be calculated by “Vcm = Vam + ΔVrm” (step S9). For example, when the bypass unit 19-1 of the cell battery 1 is turned on, the voltage detection value Va1 detected by the voltage detection unit 13 and the voltage drop value ΔVr1 are added to correct the voltage detection value (Vc1 = Va1 + ΔVr1). ).

  In addition, when it determines with not performing bypass operation by bypass part 19-m in step S3 (step S3: No), since the bypass current Ibm does not flow and a voltage drop does not arise, correction | amendment is not performed. That is, the cell voltage (terminal voltage of the bypass unit 19-m) Vam detected by the voltage detection unit 13 without the bypass operation becomes the true cell voltage Vcm (Vcm = Vam) (step S9). For example, in the case of the cell battery 2 shown in FIG. 1, no correction is performed because the bypass current Ib2 does not flow and no voltage drop occurs. As a result, the cell voltage Vc2 of the cell battery 2 without the bypass operation becomes the true cell voltage Vc2 (Vc2 = Va2) from the cell voltage (terminal voltage of the bypass unit 19-2) Va2 detected by the voltage detection unit 13.

  As described above, the charge control device 11 measures the cell voltages Vc1, Vc2, by measuring the terminal voltages at both ends C, D of the bypass unit 19 connected in parallel to the cell batteries 1, 2,. .., Vcn is detected even when a voltage drop due to the bypass current Ib occurs in the voltage measurement line La connecting the cell batteries 1, 2,. The voltages Vc1, Vc2,..., Vcn can be easily detected.

  As mentioned above, although embodiment of this invention was described, the function in the control part 12, the voltage detection part 13, the bypass control part 14, the cell voltage calculation part 15, and the charging device control part 17 in the charge control apparatus 11 shown in FIG. Can be realized using dedicated hardware (for example, a logic IC such as a gate array). Also, a computer system including a CPU (central processing unit such as a microcomputer or DSP) is provided in the charging control device 11, and the control unit 12, the voltage detection unit 13, the bypass control unit 14, the cell voltage calculation unit 15, and the charging A series of processing steps related to the processing in the apparatus control unit 17 is stored in a computer-readable recording medium in the form of a program, and the CPU reads and executes the program, whereby the above-described processing can be performed. That is, in each process in the control unit 12, the voltage detection unit 13, the bypass control unit 14, the cell voltage calculation unit 15, and the charging device control unit 17, the CPU reads the program and executes information processing and calculation processing. Can be realized.

  Further, the bypass unit of the present invention corresponds to the bypass unit 19, and the voltage detection unit of the present invention corresponds to the voltage detection unit 13. Further, the bypass control unit of the present invention corresponds to the bypass control unit 14. The cell voltage calculation unit 15 of the present invention corresponds to the cell voltage calculation unit 15. Further, the impedance circuit of the present invention corresponds to the bypass resistor R. The voltage measurement line of the present invention corresponds to the voltage measurement lines La and Lb. The closed-circuit terminal voltage corresponds to the terminal voltage Va of the bypass unit.

In the charge control device 11 shown in FIG. 1, the bypass unit 19 selectively conducts or does not conduct the impedance circuit (bypass resistor R) provided in parallel for each of the cell batteries 1, 2,. To. The voltage detection unit 13 detects the closed-circuit terminal voltage (terminal voltage of the bypass unit) Va when the bypass unit 19 is turned on from the terminal voltage of the bypass unit 19. The cell voltage calculation unit 15 includes the closed terminal voltage Va, the impedance value of the voltage measurement line La connecting the cell batteries 1, 2,..., N and the bypass unit 19, and the impedance value of the bypass unit 19 (of the bypass resistor R). The cell voltage Vc of the cell batteries 1, 2,..., N is calculated from the resistance value.
Thereby, when measuring the terminal voltage (closed terminal voltage) Va at both ends of the bypass unit 19 selectively connected in parallel to the cell batteries 1, 2,..., N and detecting the cell voltage Vc, Even when the bypass current Ib flows through the voltage measurement line La connecting the cell batteries 1, 2,..., N and the bypass unit 19 to cause a voltage drop, the accurate value of the cell voltage Vc can be detected. .
In addition, the detection of the closed terminal voltage of each cell battery by the voltage detection unit 13 may be performed according to a predetermined order or may be performed at random. The switching of the impedance circuit (bypass resistor R), which is performed by the bypass unit 19, can be performed at an arbitrary timing in addition to the detection of the closed-circuit terminal voltage by the voltage detection unit 13.

Further, in the charging control device 11, the impedance storage unit 16 has an impedance value (a fuse internal resistance rf and a wiring pattern) of the voltage measurement line La connecting the cell batteries 1, 2,. The impedance component r) and the impedance value of the bypass unit 19 (resistance value of the bypass resistor R) are stored. The cell voltage calculation unit 15 calculates the bypass current Ib flowing through the bypass unit 19 based on the closed-circuit terminal voltage Va when the bypass unit 19 is turned on and the impedance value of the bypass unit 19 (resistance value of the bypass resistor R). Then, the correction value ΔVr is calculated based on the bypass current Ib and the impedance value of the voltage measurement line La, and the cell voltage Vc is calculated based on the closed circuit terminal voltage Va and the correction value ΔVr.
Thus, an accurate cell voltage Vc can be calculated based on the terminal voltage Va at both ends of the bypass unit 19 that is selectively connected in parallel to the cell battery.

Further, in the charging control device 11, the bypass control unit 14 conducts or bypasses the bypass unit 19 based on the cell voltage Vc of the cell batteries 1, 2,..., N calculated by the cell voltage calculation unit 15. To. The bypass control unit 14 makes the bypass unit 19 non-conductive when the calculated cell voltage is insufficient with respect to a predetermined threshold voltage set in advance, and bypasses when the calculated cell voltage is reached. The part 19 is made conductive.
Thereby, in addition to the effect of being able to detect an accurate value of the cell voltage Vc, charging is performed while balancing the charging voltages of the cell batteries 1, 2,..., N based on the detected cell voltage Vc. It can be carried out

  The bypass resistors R1, R2,..., Rn in the bypass portions 19-1, 19-2,..., 19-n may have a desired impedance instead of the pure resistors. . Further, it may be a constant current circuit that performs current limiting. Further, the bypass resistors R1, R2,..., Rn can be internal resistors of the bypass switches SW1, SW2,.

  Further, in the present embodiment, the impedance storage unit 16 includes a component (for example, the internal resistance rf of the fuse F1) existing in the voltage measurement line La, an impedance component r existing on the wiring pattern, and a total value Z of those impedances. However, the present invention is not limited to this. For example, if the value of the impedance (bypass resistance R) of the bypass unit 19 is stored, the bypass current Ib can be calculated based on the closed-circuit terminal voltage Va when the bypass unit 19 is turned on. Based on the terminal voltage Va ′ of the bypass unit 19 when the bypass unit 19 is turned off and the terminal voltage Va of the bypass unit 19 when the bypass unit 19 is turned on, the impedance existing in the voltage measurement line La Can be calculated by Z = (Va′−Va) / Ib. That is, if only the value of the bypass resistor R in the bypass unit 19 is stored, the impedance value of the voltage measurement line La can be automatically detected.

  As mentioned above, although embodiment of this invention was described, the charge control apparatus of this invention is not limited only to the above-mentioned example of illustration, A various change can be added in the range which does not deviate from the summary of this invention. Of course.

1, 2, ..., n Cell batteries 11, 11A Charge control device 12 Control unit 13 Voltage detection unit 14 Bypass control unit 15 Cell voltage calculation unit 16 Impedance storage unit 17 Charging device control units 18-1, 18-2, ..., 18-n Measurement line impedance equivalent circuits 19-1, 19-2, ..., 19-n Bypass sections R1, R2, ..., Rn Bypass resistors (impedance circuits)
, Lan voltage measurement lines Lb1, Lb2,..., Lbn voltage measurement lines SW1, SW2,..., SWn bypass switches Ib1, Ib2,. Ibn bypass current Vc1, Vc2,..., Vcn cell voltage Va1, Va2,..., Van cell voltage (terminal voltage of bypass section)

Claims (5)

A charging control device that charges a plurality of cell batteries connected in series by a battery charging device,
Impedance circuits are provided in parallel for each cell battery, and the wiring from the cell battery to the impedance circuit corresponding to the cell battery is used as a voltage measurement line, and a fuse is connected to the wiring of the voltage measurement line. Each cell battery is configured so that a common wiring section does not occur between the voltage measurement lines of each cell battery when calculating the voltage of each cell battery. between the wiring from the wiring and the other cell batteries to the impedance circuit corresponding to the impedance circuit corresponding to the other cells batteries, it is configured so as not to cause the common impedance with each other, to the cell battery A bypass unit that selectively turns on or off the impedance circuit provided in parallel;
From the terminal voltage of the bypass unit, a voltage detection unit that detects a closed-circuit terminal voltage when the bypass unit is conducted, and
From the closed terminal voltage, the impedance value of the voltage measurement line connecting the cell battery and the bypass unit, and the impedance value of the bypass unit, a cell voltage calculation unit that calculates the cell voltage of the cell battery,
A charge control device comprising: An impedance storage unit that stores an impedance value of a voltage measurement line that connects each cell battery and the bypass unit corresponding to the cell battery, and an impedance value of the bypass unit,
The cell voltage calculator is
Based on the closed-circuit terminal voltage and the impedance value of the bypass unit when the bypass unit is conducted, calculate a bypass current flowing in the bypass unit,
Calculate a correction value based on the bypass current and the impedance value of the voltage measurement line,
The charge control device according to claim 1, wherein a cell voltage of a cell battery is calculated based on the closed circuit terminal voltage and the correction value. The cell voltage calculator is
By dividing the closed-circuit terminal voltage by the impedance value of the bypass unit, the bypass current is calculated,
By multiplying the bypass current and the impedance value of the voltage measurement line,
Calculating the correction value;
The charge control device according to claim 2, wherein the cell voltage is calculated by adding the closed terminal voltage and the correction value. Based on the cell voltage calculated by the cell voltage calculation unit, comprising a bypass control unit for making the bypass unit conductive or non-conductive,
The bypass control unit
When the calculated cell voltage is insufficient with respect to a predetermined threshold voltage determined in advance, the bypass unit is turned off, and when the calculated cell voltage is reached, the bypass unit is turned on. The charge control device according to any one of claims 1 to 3, wherein: A charge control method in a charge control device that charges a plurality of cell batteries connected in series by a battery charger,
By the control unit in the charge control device,
Impedance circuits are provided in parallel for each cell battery, and the wiring from the cell battery to the impedance circuit corresponding to the cell battery is used as a voltage measurement line, and a fuse is connected to the wiring of the voltage measurement line. Each cell battery is configured so that a common wiring section does not occur between the voltage measurement lines of each cell battery when calculating the voltage of each cell battery. between the wiring from the wiring and the other cell batteries to the impedance circuit corresponding to the impedance circuit corresponding to the other cells batteries, it is configured so as not to cause the common impedance with each other, to the cell battery A bypass procedure for selectively conducting or non-conducting an impedance circuit provided in parallel;
From the terminal voltage of the impedance circuit, a voltage detection procedure for detecting a closed circuit terminal voltage when the impedance circuit is conducted by a voltage detection unit,
A cell voltage calculation procedure for calculating a terminal voltage of the cell battery from the closed terminal voltage, an impedance value of a voltage measurement line connecting the cell battery and the impedance circuit, and an impedance value of the impedance circuit;
Is performed. The charge control method characterized by the above-mentioned.

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