CN111628538A

CN111628538A - Battery system, motor driving device and power supply control method

Info

Publication number: CN111628538A
Application number: CN202010364326.8A
Authority: CN
Inventors: 程洋; 章雪亮
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-09-04
Also published as: WO2021218813A1

Abstract

The embodiment of the application discloses a battery system, a motor driving device and a power supply control method. The battery system comprises N battery devices which are connected in series, wherein each battery device comprises a first battery, a first capacitor, a first switch, a first endpoint and a second endpoint, if the first battery fails, because the first endpoint is connected with a first end of the first capacitor and a first end of the first switch, the second endpoint is connected with a second end of the first capacitor and a second end of the first battery, a second end of the first switch is connected with the first end of the first battery, the first battery is bypassed by the first capacitor by controlling the first switch, in the N battery devices, the first endpoint of the ith battery device is connected with the second endpoint of the i-1 battery device, the second endpoint of the ith battery device is connected with the first endpoint of the i +1 battery device, wherein i is a positive integer and 1< i < N, the battery system can continue to discharge and has fault-tolerant capability, the reliability is high.

Description

Battery system, motor driving device and power supply control method

Technical Field

The present disclosure relates to a battery, and more particularly to a battery system, a motor driving apparatus, and a power supply control method.

Background

With the development of new energy field, batteries (also called power batteries) are used more and more frequently, and the safety performance requirements are higher and higher. At present, a plurality of batteries mainly form a holistic battery package through direct series connection, for consumer such as motors among the electric automobile supplies power.

However, during the use of the battery, a failure such as a short circuit is very likely to occur due to heat dissipation or the like. Since the batteries in the battery pack are connected in series, when a short circuit occurs in a certain battery, the battery may be ignited, and thus a fault may be diffused throughout the battery pack. Therefore, the current battery system has no fault-tolerant capability and low reliability.

Disclosure of Invention

The embodiment of the application provides a battery system, a motor driving device and a power supply control method, which are used for preventing fault diffusion and ensuring continuous work of the battery system when a battery fails.

In a first aspect, the present application provides a battery system, comprising:

the battery device comprises N battery devices which are connected in series, wherein each battery device in the N battery devices comprises a first battery, a first capacitor, a first switch, a first endpoint and a second endpoint, the first endpoint is connected with the first end of the first capacitor and the first end of the switch, the second endpoint is connected with the second end of the first capacitor and the second end of the first battery, the second end of the first switch is connected with the first end of the first battery, and N is a positive integer greater than 1. In the N battery devices, a first end point of the ith battery device is connected with a second end point of the (i-1) th battery device, and a second end point of the ith battery device is connected with a first end point of the (i + 1) th battery device, wherein i is a positive integer and 1< i < N.

When the battery system discharges, if a first battery of a certain battery device fails, because the battery device includes the first battery, a first switch, a first capacitor, a first endpoint and a second endpoint, the first endpoint is connected to a first end of the first capacitor and a first end of the first switch, the second endpoint is connected to a second end of the first capacitor and a second end of the first battery, and a second end of the first switch is connected to a first end of the first battery, the first switch can be turned off to form an open circuit of the first battery, so as to prevent the fault from spreading.

In some possible implementations, in the N battery devices connected in series, the first end of the first battery device and the second end of the nth battery device are used as charging ports of the battery system, the first switch is a bidirectional switch, and the first capacitor is a non-polar capacitor, so that the battery system can be both discharged and charged.

In some possible implementations, the first end point and the second end point of each of the N battery devices are used as output ports for providing low-voltage power, so that the battery system can simultaneously provide direct current for the N low-voltage power consumers.

In some possible implementations, the first switch is a fuse or a fuse, so that when the first battery is short-circuited, the flowing current is likely to exceed a certain value, and a turn-off signal is not required to be sent to the first battery, and the first switch is automatically turned off.

In some possible implementations, the battery system further includes a first controller, where the first controller is configured to, when there is at least one failed battery device among the N battery devices, control the first switch to bypass the first battery by the first capacitor within each failed battery device, so that the battery system may continue to discharge through other battery devices.

In some possible implementation manners, the battery system further includes a second controller, where the second controller is configured to, when an external load of at least one low-voltage power supply output port fails, control the first switch to bypass the first battery by the first capacitor in the battery device corresponding to each failed external load, so that the battery system may continue to supply power to other external loads through other battery devices.

In some possible implementations, the first terminal of the first battery device and the second terminal of the nth battery device in the N battery devices are used as output ports for providing high-voltage power, so that the battery system can provide direct current for the high-voltage electric devices.

In some possible implementations, the first switch is a mechanical switch or a metal-oxide-semiconductor-field-effect-transistor (MOSFET) switch to which a turn-off signal may be sent when the battery fails.

In some possible implementations, the MOSFET switch is 1 MOSFET, the current conducting direction of the MOSFET switch is the current direction when the battery is discharged, the MOSFET can be energized only from one direction, and the other direction cannot be energized, and the first capacitor is a polar capacitor, the current conducting direction of the first capacitor is the current direction when the battery is discharged, the polar capacitor can be energized only from one direction, and the other direction cannot be energized, so that the battery system can be discharged and cannot be charged.

In some possible implementation manners, the MOSFET switches are 2 MOSFETs connected in series, the current conduction directions of the 2 MOSFETs are opposite, bidirectional energization can be achieved, the first capacitor is a nonpolar capacitor, bidirectional energization can be achieved by the capacitor, and therefore the battery system can be charged or discharged.

In some possible implementations, a current sensor may be connected in series with the first battery and send a current overload signal to the first controller when the current exceeds a threshold value, so that the first controller determines that the first battery has failed and sends a shutdown signal to the first switch. In some possible implementations, the current sensor may be a part of the first switch, or may be a separate component, which is not limited herein.

In a second aspect, the present application provides a motor driving apparatus comprising at least one inverter and the battery system as described in the first aspect, wherein a first end point and a second end point of each of the N battery devices of the battery system are used as output ports for providing low-voltage power supply, wherein the at least one inverter is connected to at least one output port of the battery system for providing low-voltage power supply, so that the motor driving apparatus can provide alternating current.

In some possible implementations, the at least one inverter is at least two single-phase H-bridge inverters, and the first end point and the second end point of each of the N battery devices are used as output ports for providing low-voltage power supply, and one single-phase H-bridge inverter of the at least two single-phase H-bridge inverters is connected to the battery system, so that the battery system can provide multi-phase alternating current for the multi-phase motor.

In some possible implementations, the at least one inverter is at least 4 three-phase full-bridge inverters, the first end point and the second end point of each battery device in the N battery devices are used as output ports for providing low-voltage power supply, and the at least 4 three-phase full-bridge inverters are respectively connected to two three-phase full-bridge inverters, so that the battery system can provide three-phase alternating current for the multi-three-phase motor.

In a third aspect, the present application provides a motor driving apparatus including at least one high-voltage electric device and the battery system as described in the first aspect, wherein in the N battery devices of the battery system, a first terminal of the first battery device and a second terminal of the nth battery device are used as output ports for providing high-voltage power, and at least one high-voltage electric device is connected to the output ports for providing high-voltage power in the battery system, so that the battery system can provide direct current for the high-voltage electric device.

In some possible implementations, the high voltage electrical device may be an air conditioner or a thermistor (PTC) heater, so that the power supply of the air conditioner and/or the PTC heater is more stable.

In some possible implementations, the at least one inverter is a three-phase full-bridge inverter, and of the N battery devices connected in series, the first end of the first battery device and the second end of the nth battery device are used as output ports for providing high-voltage power, and the three-phase full-bridge inverter is connected to the battery system, so that the battery system can provide high-voltage alternating current.

In a fourth aspect, the present application provides a power supply control method for a battery system as described in the first aspect, the battery system further including a first controller configured to bypass a first battery by a first capacitor by controlling a first switch within each failed battery when there is at least one failed battery out of the N battery devices, the method including:

each battery device in the N battery devices is monitored, when at least one failed battery device exists in the N battery devices, the first battery is bypassed by the first capacitor by controlling the first switch in each failed battery device, and therefore the first battery is disconnected, fault diffusion is prevented, and the battery system can continue to discharge through other battery devices due to the fact that current passes through the first capacitor.

In a fifth aspect, the present application provides a power supply control method, where the method is applied to the battery system according to the first aspect, the battery system further includes a second controller, where the second controller is configured to control a first switch to bypass a first battery by a first capacitor in a battery device corresponding to each external load that has a fault when an external load of at least one low-voltage power supply output port has a fault, and the method includes:

the external load of the output port of each low-voltage power supply in the N battery devices is monitored, when the external load of at least one output port of the low-voltage power supply fails, the first battery is bypassed by the first capacitor by controlling the first switch in the battery device corresponding to each failed external load, so that the open circuit of the first battery is formed, the fault diffusion is prevented, and the battery system can continue to discharge through other battery devices due to the passing of current from the first capacitor.

According to the technical scheme, the embodiment of the application has the following advantages:

when the battery system discharges, if a first battery of any one of the N battery devices fails, because the battery device includes the first battery, the first switch, the first capacitor, the first end point and the second end point, the first end point is connected to the first end of the first capacitor and the first end of the switch, the second end point is connected to the second end of the first capacitor and the second end of the first battery, and the second end of the first switch is connected to the first end of the first battery, the first switch can be turned off to form an open circuit of the first battery, thereby preventing the failure from spreading. And because the battery system comprises N battery devices which are connected in series, the first end point of the ith battery device is connected with the second end point of the (i-1) th battery device, and the second end point of the ith battery device is connected with the first end point of the (i + 1) th battery device, wherein i is a positive integer and 1< i < N, current can pass through the first capacitor, so that the battery system can continue to discharge through other battery devices, and the battery system has fault-tolerant capability and high reliability.

Drawings

FIG. 1 is a schematic diagram of a battery pack with a plurality of batteries connected in series to form a whole;

FIG. 2-1 is a schematic view of an embodiment of a battery system as set forth herein;

2-2 are schematic diagrams of an embodiment of a battery device proposed in the present application;

FIGS. 2-3 are schematic diagrams of an embodiment of a battery device in which a first battery has failed;

FIGS. 2-4 are schematic diagrams of embodiments of 4 cell devices connected in series;

FIGS. 2-5 are schematic diagrams of an embodiment of a battery system that remains discharged when a fault occurs;

FIGS. 2-6 are schematic diagrams of embodiments of a battery system according to the present disclosure;

FIGS. 2-7 are schematic diagrams of embodiments of 2 MOSFETs in series;

FIGS. 2-8 are schematic diagrams of another embodiment of a series 4 cell device

Fig. 2 to 9 are schematic diagrams of an embodiment of a connection mode 1 of a battery system and electric equipment;

fig. 2 to 10 are schematic diagrams of an embodiment of a connection mode 2 of a battery system and electric equipment;

FIGS. 2-11 are schematic diagrams of embodiments of a battery system according to the present disclosure;

FIGS. 2-12 are schematic diagrams of embodiments of connections of a battery device to a powered device;

fig. 2 to 13 are schematic diagrams of an embodiment of a connection mode 3 of a battery system and electric equipment;

FIGS. 2-14 are schematic diagrams of the current path of a battery device during charging with a failure of a first battery;

FIGS. 2-15 are schematic diagrams of current paths of a battery system during charging with a failure of a first battery;

FIG. 3-1 is a schematic view of an embodiment of a motor drive apparatus proposed in the present application;

3-2 is a schematic diagram of a three-phase full bridge inverter;

3-3 are schematic diagrams of a single-phase H-bridge inverter;

3-4 are schematic diagrams of embodiments in which each of the N battery devices is connected to a respective inverter;

3-5 are schematic diagrams of embodiments in which two inverters are connected to each of the N battery devices, respectively;

3-6 are schematic diagrams of two inverter carriers;

3-7 are schematic diagrams of embodiments of a battery system in parallel with an inverter;

FIG. 4-1 is a schematic diagram of an embodiment of an electric vehicle further provided by the present application;

4-2 are schematic views of an embodiment of a motor driving device connected with a motor;

4-3 are schematic views of another embodiment of a motor drive coupled to a motor;

4-4 are schematic views of another embodiment of a motor drive coupled to a motor;

4-5 are schematic diagrams of an embodiment of a motor drive device in an electric vehicle coupled to an air conditioner and/or PTC heater;

FIG. 5-1 is a schematic view of an embodiment of a motor drive apparatus further provided in the present application;

5-2 are schematic diagrams of embodiments in which the high voltage electrical device is an air conditioner and/or PTC heater;

5-3 are schematic diagrams of embodiments in which the high-voltage electric device is a three-phase full-bridge inverter;

fig. 6 is a schematic diagram of an embodiment of a power supply control method provided in the present application;

fig. 7 is a schematic diagram of an embodiment of a power supply control method provided in the present application.

Detailed Description

With the development of new energy field, batteries (also called power batteries) are used more and more frequently, and the safety performance requirements are higher and higher. At present, a plurality of batteries mainly form a holistic battery package through the mode of direct series connection, for consumer such as motor among the electric automobile supplies power. Specifically, as shown in fig. 1, a plurality of batteries are connected in series to form an integrated battery pack, and the battery pack is used for supplying direct current to an inverter, and the inverter converts the direct current into alternating current, so as to supply alternating current to the motor. The battery pack may be discharged or charged.

To this end, the present application provides a battery system, and referring to fig. 2-1, the battery system 200 includes N battery devices 210 connected in series. Among the N battery devices 210, the first terminal 214 of the ith battery device 210 is connected to the second terminal 215 of the (i-1) th battery device 210, and the second terminal 215 of the ith battery device 210 is connected to the first terminal 214 of the (i + 1) th battery device 210, where i is a positive integer and 1< i < N.

As shown in fig. 2-2, each battery device 210 of the N battery devices 210 includes a first battery 211, a first capacitor 212, a first switch 213, a first terminal 214, and a second terminal 215, the first terminal 214 is connected to a first terminal of the first capacitor 212 and a first terminal of the first switch 213, the second terminal 215 is connected to a second terminal of the first capacitor 212 and a second terminal of the first battery 211, and a second terminal of the first switch 213 is connected to the first terminal of the first battery 211, where N is a positive integer greater than 1.

In the embodiment of the present application, when the battery system 200 is discharged, inside the battery device 210, the current respectively passes through two paths connected in parallel, one path is the first switch 213 and the first battery 211 connected in series, and the other path is the first capacitor 212. As shown in fig. 2-3, when the first battery 211 fails, the first switch 213 is turned off, the path of the series-connected first switch 213 and the first battery 211 is not accessible, and the current can still flow through the other path, i.e. from the second terminal 215 to the first terminal 214 through the first capacitor 212, so that the battery device 210 can be kept on before the first battery 211 is turned off.

As shown in fig. 2-4, the battery system 200 is described by taking 4 battery devices 210 connected in series as an example, where the 4 battery devices 210 are respectively a battery device 1, a battery device 2, a battery device 3 and a battery device 4, a second terminal 215 of the battery device 1 is connected to a first terminal 214 of the battery device 2, a second terminal 215 of the battery device 2 is connected to a first terminal 214 of the battery device 3, and a second terminal 215 of the battery device 3 is connected to the first terminal 214 of the battery device 4. Then, since the battery device 210 can be kept on before the first battery 211 is turned off, the battery system 200 is kept discharged as shown in fig. 2 to 5.

In the field of new energy vehicles, the first battery 211 is also called a power battery, and is a power source of the new energy vehicle and a core component of the new energy vehicle. Common power batteries include lead-acid batteries, nickel-metal hydride batteries, and lithium power batteries. In the present embodiment, the first battery 211 is used to provide direct current.

In some possible implementations, the first capacitor 212 may be a polar capacitor or a non-polar capacitor. A polarized capacitor can only be energized from one direction, the other direction cannot, and a non-polarized capacitor can be energized in both directions.

When the battery system 200 is discharged, the current passing through the first capacitor 212 is from the second terminal 215 to the first terminal 214, and if the first capacitor 212 is a polar capacitor, the current passing direction of the first capacitor 212 in fig. 2-2 should also be from the second terminal 215 to the first terminal 214.

In the embodiment of the present application, the first switch 213 has two states of on and off. When the battery system 200 is discharged, if no battery fails, the first switch 213 remains on, that is, the first battery 211 continues to discharge; when the first battery 211 in a certain battery device 210 has a fault, the first switch 213 enters an off state, i.e., turns off the path of the first battery 211, as shown in fig. 2-3, so that the fault of the first battery 211 does not propagate.

In some possible implementations, the first switch 213 may be a controllable switch, such as a mechanical switch or a MOSFET switch, and then as shown in fig. 2-6, the battery system 200 further includes a first controller 220-1 for bypassing the first battery 211 by the first capacitor 212 by controlling the first switch 213 within each failed battery device 210 when there is at least one failed battery device 210 among the N battery devices 210.

Specifically, the first controller 220-1 and the first switch 213 may be connected wirelessly or through a wire, which is not limited herein. When the first controller 220-1 sends a conducting signal to the first switch 213, the first switch 213 enters a conducting state; when the first controller 220-1 sends an off signal to the first switch 213, the first switch 213 enters an on state. In some possible implementations, the on signal may be 1, the off signal may be 0, or other types of signals, which are not limited herein.

In some possible implementations, the first battery 211 may be connected in series with a current sensor, which sends a current overload signal to the first controller 220-1 when the current exceeds a threshold value, so that the first controller 220-1 determines that the first battery 211 has a fault, and the first controller 220-1 sends a turn-off signal to the first switch 213. In some possible implementations, the current sensor may be a part of the first switch 213 or a separate component, which is not limited herein.

The mechanical switch is an electronic component that can open a circuit or interrupt a current. The mechanical switch has two states, namely "closed" and "open", wherein "closed" means allowing current to flow, i.e. conducting; an "open circuit" means that no current is allowed to flow, i.e. is turned off. In an embodiment of the present application, the mechanical switch may include a signal receiver, and the mechanical switch enters a "closed" state when receiving the on signal and enters an "open" state when receiving the off signal.

The MOSFET switch is composed of a MOSFET and is constructed by utilizing the principle that the grid electrode of the MOSFET controls the source electrode and the drain electrode of the MOSFET to be switched on and off. In the embodiment of the present application, the MOSFET switch may be connected through the first controller 220-1, and the MOSFET switch may be controlled to be turned on or off by applying currents of different voltages to the MOSFET switch.

It should be noted that the MOSFET switch may be a unidirectional switch, or may be a bidirectional switch, and is not limited herein. When the MOSFET switch is a unidirectional switch, the MOSFET switch is constituted by 1 MOSFET, and the MOSFET can be energized only from one direction and cannot be energized from the other direction. When the MOSFET switch is a bidirectional switch, as shown in fig. 2 to 7, the MOSFET switch is composed of 2 MOSFETs connected in series, and the current conduction directions of the 2 MOSFETs are opposite to each other, so that bidirectional conduction can be realized. As shown in fig. 2-2, when the battery system 200 is discharged, the current passing through the first switch 213 is from the second terminal 215 to the first terminal 214, so if the MOSFET switch is a unidirectional switch, the current passing direction of the first switch 213 in fig. 2-2 should also be from the second terminal 215 to the first terminal 214.

In some possible implementation manners, the first controller 220-1 may be a Micro Controller Unit (MCU), which is also called a single chip microcomputer (single chip microcomputer) or a single chip microcomputer, and is configured to appropriately reduce the frequency and specification of a Central Processing Unit (CPU), and integrate peripheral interfaces such as a memory (memory), a counter (timer), a Universal Serial Bus (USB), an analog-to-digital converter (a/D), and the like on a single chip, so as to form a chip-level computer, thereby performing different combination control for different application occasions.

In some possible implementations, the first switch 213 may also be an uncontrollable switch, such as a fuse or a fuse, which automatically turns off when the voltage of the passing current exceeds a certain value, without sending a turn-off signal to it.

In the embodiment of the present application, when the battery system 200 is connected to the electric device, the electric device may be powered. The electric device may be a motor, a PTC heater, or an air conditioner, and is not limited herein. Specifically, the connection manner of the battery system 200 and the electric device may include various manners, and three connection manners of the battery system 200 and the electric device are listed as examples below.

In the following description of various examples of the battery system 200 and the electric device, the battery system 200 is described by taking an example in which the battery system 200 has 4 battery devices 210, and as shown in fig. 2 to 8, the battery system 200 includes a battery device 1, a battery device 2, a battery device 3, and a battery device 4 connected in series, where a second end of the battery device 1 is connected to a first end of the battery device 2, a second end of the battery device 2 is connected to a first end of the battery device 3, and a second end of the battery device 3 is connected to a first end of the battery device 4.

Connection mode 1: of the N battery devices, a first terminal of a first battery device and a second terminal of an Nth battery device are used as output ports for providing high-voltage power supply. As shown in fig. 2 to 9, if the first battery device 210 and the 4 th battery device 210 in the 4 battery devices 210 connected in series are the battery devices 1 and 4, the first terminal of the battery device 1 and the second terminal of the battery device 4 can be respectively used as the first terminal and the second terminal of the battery system 200, and can be used as output ports for supplying high voltage power, and are respectively connected to the electric devices, and provide direct current power for the electric devices.

Connection mode 2: of the N battery devices 210, the first terminal 214 and the second terminal 215 of each battery device 210 are used as output ports for providing low voltage power supply. As shown in fig. 2 to 10, each battery device 210 of the series-connected 4 battery devices 210 may also be independently connected to its own electrical equipment through the first terminal 214 and the second terminal 215, so as to provide low-voltage direct current for its own electrical equipment. It should be noted that, in fig. 2-10, each battery device 210 is exemplarily connected to the electric device by a line, which means that the battery device 210 and the electric device establish a closed power loop, so that the battery device 210 can supply power to the electric device. Specifically, at the level of the battery device 210, the battery device 210 and the electrical equipment may be connected as shown in fig. 2 to 12, and the battery device 210 supplies power to the electrical equipment through a closed power-on loop.

In some possible implementations, as shown in fig. 2 to 11, the battery system 200 further includes a second controller 220-2, where the second controller 220-2 is configured to control the first switch 213 to bypass the first battery 211 by the first capacitor 212 within the battery device 210 corresponding to each external load that has a fault when an external load (e.g., the electric device shown in fig. 2 to 10) of at least one output port that is powered by low voltage fails. In some possible implementations, the external load may be an inverter, a motor, an air conditioner, a PTC heater, or the like, which is not limited herein.

In some possible implementations, the external load may be connected in series with a current sensor, and when the current exceeds the threshold, the current sensor will send a current overload signal to the second controller 220-2, so that the second controller 220-2 determines that the external load has failed, and then the second controller 220-2 will send a turn-off signal to the first switch 213. In some possible implementations, the current sensor may be a part of an external load or may be a separate component, which is not limited herein.

In other possible implementations, as shown in fig. 2 to 13, each battery device 210 of the N battery devices 210 may also connect the first terminal 214 and the second terminal 215 to the electric device, respectively, so as to supply power to the same electric device. The electric device is a device that can receive a plurality of power sources at the same time. Similarly, in fig. 2 to 13, each battery device 210 is connected to the electric device through a line, which is only an example, and shows that the battery device 210 and the electric device establish a closed path, so that the battery device 210 can provide direct current for the electric device, and details are not described herein.

In some possible implementations, the battery system 200 may be connected to the electric device in other ways, which are not limited herein.

In some possible implementations, the battery system 200 may not only discharge, but also charge. Of the N battery devices 210 connected in series, the first terminal 214 of the first battery device 210 and the second terminal 215 of the nth battery device 210 are used as charging ports of the battery system 200, and the charging ports of the battery system 200 are used for charging the N battery devices by connecting a dc bus, which connects a power source, and connecting the N battery devices in series.

It should be noted that, when the battery system 200 is charged, the current direction is opposite to the current direction during discharging, and in fig. 2-2, the current direction of the battery device 210 during charging is from the first terminal 214 to the second terminal 215. Similarly, the current passes through the left and right sides, respectively, wherein the first battery 211 and the first switch 213 are disposed on one side, and the first capacitor 212 is disposed on the other side. In order to charge the battery device 210 smoothly, the first switch 213 and the first capacitor 212 need to be energized in a direction from the first terminal 214 to the second terminal 215, and in the embodiment of the present application, both the first switch 213 and the first capacitor 212 must be conducted bidirectionally. The bidirectional conducting switch is a bidirectional switch and comprises a mechanical switch and two MOSFETs connected in series, wherein the current conducting directions of the two MOSFETs are opposite. The first capacitor 212 that is conducted in two directions is a non-polar capacitor, i.e., a capacitor that can be conducted in two directions.

Specifically, as shown in fig. 2-7, the two MOSFETs are shown in series, which are respectively S1 and S2, wherein the current conducting directions of S1 and S2 are opposite. The MOSFET switch formed by two MOSFETs connected in series has two effective operating states of on and off, and specifically, when both S1 and S2 are applied with an on signal, the bidirectional switch is in an on state, and the battery device 210 can be both discharged and charged. When the turn-off signal is applied at both S1 and S2, the bi-directional switch is in the off state, and then current flows through the first capacitor 212 during charging, so that the battery system 200 can continue to charge. In some possible implementations, if S1 is on and S2 is off, then the current direction is S1 to S2; if S1 is turned off and S2 is turned on, the current direction is S2 to S1.

As shown in fig. 2-14, when the first battery 211 fails, the first switch 213 is turned off, the path of the series connection of the first switch 213 and the first battery 211 is not available, and the current can still flow from the first terminal 214 to the second terminal 215 through the other path, i.e., the first capacitor 212.

Then, if the battery device 1 shown in fig. 2-15 fails, the battery system 200 does not stop discharging, but the first switch 213 is turned off, so that the current bypasses the first battery 211 in the battery device 1 and only passes through the first capacitor 212 in the battery device 1, and therefore the battery system 200 can continue to be charged, so that the battery system 200 has fault tolerance capability and thus has high reliability.

The above describes how the battery system 200 continues to remain operational, i.e., continue to provide dc power, when individual batteries fail during discharge and charge. However, some devices require alternating current, such as an electric motor, and therefore when the battery system 200 supplies power to the electric motor, an inverter is connected, which converts direct current into alternating current so that the electric motor can be driven.

To this end, referring to fig. 3-1, the present application further provides a motor driving apparatus 300, which includes at least one inverter 310 and the battery system 200 as described above, wherein the at least one inverter 310 is connected to at least one output port of the battery system 200 for providing low-voltage power.

The inverter 310 is a converter for converting dc power into ac power, and is composed of an inverter bridge, control logic, and a filter circuit, and is widely used, for example, in motors and home appliances. Common inverters 310 are three-phase full-bridge inverters and single-phase H-bridge inverters. The three-phase full-bridge inverter is shown in fig. 3-2 and used for converting direct current into three-phase alternating current for electric equipment, and the single-phase H-bridge inverter is shown in fig. 3-3 and used for converting direct current into single-phase alternating current for electric equipment.

In the embodiment of the present application, the types of the inverters 310 and the corresponding connection manner with the battery system 200 may be various, and 3 of the inverters are described below by way of example. The following examples are merely illustrative and are not intended to be limiting.

Connection mode 1: the at least one inverter 310 is at least two single-phase H-bridge inverters, and the first terminal 214 and the second terminal 215 of each battery device 210 in the N battery devices 210 are used as output ports for providing low-voltage power supply, and are respectively connected with one single-phase H-bridge inverter of the at least two single-phase H-bridge inverters.

Specifically, as shown in fig. 3-4, each battery device 310 of the 4 battery devices 210 is connected in parallel with one inverter 310, so that the inverter 310 is usually a single-phase H-bridge inverter. Then, each inverter 310 may provide single-phase alternating current. For example, if the number of N battery devices 210 is 4, and each battery device 210 is connected to one inverter 310 for a total of 4 inverters 310, such a motor driving apparatus can provide 4-phase current for driving a multi-phase motor. In some possible implementations, the at least one inverter 310 may also be a three-phase full-bridge inverter, and such a motor drive may then provide 4 three-phase currents for driving a multi-three-phase motor. Then, if the first battery 213 in any battery device 210 in the battery system 200 fails, the battery system 200 can still continue to discharge, so that the motor driving device 300 has fault tolerance and high reliability.

Connection mode 2: the at least one inverter 310 is at least 4 three-phase full-bridge inverters, and the first terminal 214 and the second terminal 215 of each battery device 210 in the N battery devices 210 are used as output ports for providing low-voltage power supply, and two three-phase full-bridge inverters in the at least 4 three-phase full-bridge inverters are respectively connected.

Specifically, as shown in fig. 3 to 5, each battery device 210 of the 4 battery devices is respectively connected in parallel with two inverters 310, and the inverters 310 are three-phase full-bridge inverters, so that such a motor driving device can provide multiple three-phase currents for driving multiple three-phase motors. Then, if the first battery 213 in any battery device 210 in the battery system 200 fails, the battery system 200 can still continue to discharge, so that the motor driving device 300 has fault tolerance and high reliability.

In some possible implementations, in each battery device 210, the first battery 211 respectively supplies two three-phase full-bridge inverters (respectively, 1# inverter and 2# inverter), Pulse Width Modulation (PWM) carriers of the two three-phase full-bridge inverters are staggered by 90 ° to form two inverter carriers as shown in fig. 3 to 6, and when they form a modulated wave, the bus voltage ripple and the ripple current flowing through the first capacitor 212 can be reduced.

In some possible implementations, at least one inverter 310 is connected to at least one output port of the battery system 200 that provides a high voltage supply.

Connection mode 3: at least one inverter 310 is a three-phase full-bridge inverter, and of the N battery devices 210 connected in series, the first port 214 of the first battery device 210 and the second port 215 of the nth battery device 210 are used as output ports for providing high-voltage power, and are respectively connected with the three-phase full-bridge inverter.

Specifically, as shown in fig. 3 to 7, of the 4 battery devices of the battery system 200, the first port 214 of the first battery device 210 and the second port 215 of the 4 th battery device 210 are used as output ports for providing high-voltage power, and are respectively connected to the inverter 310, so that the battery system 200 provides high-voltage direct current to the inverter 310. Then, if the first battery 213 in any battery device 210 in the battery system 200 fails, the battery system 200 can still continue to discharge, so that the motor driving device 300 has fault tolerance and high reliability. The inverter 310 in the connection mode 1 may be a three-phase full bridge inverter or a single-phase H-bridge inverter, and is not limited herein.

Referring to fig. 4-1, the present application further provides an electric vehicle 400, which includes the motor drive apparatus 300 described above with respect to the motor 410.

It should be noted that the motor 410 may be connected to one inverter 310, or may be connected to a plurality of inverters 310, and the inverter 310 may be connected to a three-phase full-bridge inverter, or may be connected to a single-phase H-bridge inverter, which is not limited herein. In the embodiment of the present application, the motor 410 may be a multi-phase motor or a multi-phase motor. The motor 410 and the inverter 310 need to be matched to be connected, and in particular, what type of motor 410 needs to be used for different types of inverters 310 is described below, respectively.

As shown in fig. 4-2, a motor 410 is connected to a plurality of single-phase H-bridge inverters 310, and the motor 410 is a multi-phase motor. As shown in fig. 4-3, the motor 410 is connected to a plurality of three-phase full-bridge inverters 310, and the motor 410 is a multi-three-phase motor. As shown in fig. 4-4, the motor 410 is connected to an inverter 310, and if the inverter 310 is a three-phase full-bridge inverter, the motor 410 is a three-phase motor; if the inverter 310 is a single-phase H-bridge inverter, the motor 410 is a single-phase motor.

In some possible implementations, as shown in fig. 4-5, the electric vehicle 400 further includes: and an air conditioner and/or PTC heater 420, the air conditioner and/or PTC heater 420 being connected in parallel with the battery system 200 in the motor driving device 300 such that the battery system 200 can supply direct current to the air conditioner and/or PTC heater 420 in addition to the alternating current to the motor 410. It should be noted that the air conditioner and/or the PTC heater 420 are only examples, and may be other devices, which are not limited herein. In some possible implementations, the air conditioner and/or PTC heater 420 may be connected to a dc bus through which the air conditioner and/or PTC heater 420 is provided with high voltage power when the battery system 200 is not being charged.

Referring to fig. 5-1, the present application further provides a motor driving apparatus 500, including: at least one high voltage consumer 510 and the battery system 200 as described above, the at least one high voltage consumer 510 is connected to an output port in the battery system 200 that provides a high voltage supply.

As shown in fig. 5-2, in some possible implementations, the high voltage electrical device 510 may be an air conditioner and/or a PTC heater. In some possible implementations, the air conditioner and/or PTC heater may be connected to a dc bus through which the air conditioner and/or PTC heater is provided with high voltage power when the battery system 200 is not being charged.

In some possible implementations, the high-voltage electric device 510 may be a three-phase full-bridge inverter. As shown in fig. 5-3, of the N battery devices 210 connected in series, the first terminal 214 of the first battery device 210 and the second terminal 215 of the nth battery device 210 are used as output ports for providing high voltage power, and are respectively connected to the three-phase full-bridge inverter. Of the 4 battery devices of the battery system 200, the first terminal 214 of the first battery device 210 and the second terminal 215 of the 4 th battery device 210 are used as output ports for providing high-voltage power, and are respectively connected to the three-phase full-bridge inverter, so that the battery system 200 provides high-voltage direct current for the three-phase full-bridge inverter. Then, if the first battery 213 in any battery device 210 in the battery system 200 fails, the battery system 200 can still continue to discharge, so that the motor driving device 300 has fault tolerance and high reliability.

Referring to fig. 6, the present application further provides a power supply control method for the battery system 200 as described above, wherein the battery system 200 further includes a first controller 220-1, and the first controller 220-1 is configured to bypass the first battery 211 by controlling the first switch 213 to the first capacitor 212 within each failed battery device 210 when there is at least one failed battery device 210 among the N battery devices 210, and the method includes:

601. it is determined that there is at least one malfunctioning battery device 210 among the N battery devices 210.

602. Within each failed battery device 210, the first battery 211 is bypassed by the first capacitor 212 by turning off the first switch 213.

In this embodiment, please refer to the method steps executed by the first controller 220-1 in fig. 2-6 for the method flows of

steps

601 and 602, which are similar to those described above and will not be described herein again. It should be noted that the method flows of

steps

601 and 602 may be executed by the first controller 220-1, or may be executed by a third-party device, and are not limited herein. In some possible implementations, the first switch 213 may also be a fuse or a fuse, and within the failed battery device 210, the first switch 213 is turned off due to a current overload.

Referring to fig. 7, the present application further provides a power supply control method for the battery system 200 as described above, where the battery system 200 further includes a second controller 220-2, and the second controller 220-2 is configured to control the first switch 213 to bypass the first battery 211 by the first capacitor 212 in the battery device 210 corresponding to each external load with a fault when the external load of at least one low-voltage power supply output port has a fault, and the method includes:

701. and determining that the external load of at least one low-voltage power supply output port has a fault.

702. Within the battery device 210 corresponding to each failed external load, the first battery 211 is bypassed by the first capacitor 212 by turning off the first switch 213.

In this embodiment, please refer to the method steps similar to those executed by the second controller 220-2 in fig. 2-11 for the method flows of

steps

701 and 702, which are not repeated herein. It should be noted that the method flows of

steps

701 and 702 may be executed by the second controller 220-2, or may be executed by a third-party device, which is not limited herein. In some possible implementations, the first switch 213 may also be a fuse or a fuse, and within the failed battery device 210, the first switch 213 is turned off due to a current overload.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the embodiments of the application and in the drawings described above, if any, are not used to describe a particular order or sequence. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Furthermore, the terms "comprises," "comprising," or "having," and any variations thereof, are intended to cover non-exclusive alternatives, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of a unit is merely a logical division, and an actual implementation may have another division, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In summary, the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A battery system, comprising:

the battery pack comprises N battery devices which are connected in series, wherein each battery device of the N battery devices comprises a first battery, a first capacitor, a first switch, a first endpoint and a second endpoint, the first endpoint is connected with a first end of the first capacitor and a first end of the first switch, the second endpoint is connected with a second end of the first capacitor and a second end of the first battery, a second end of the first switch is connected with a first end of the first battery, and N is a positive integer greater than 1;

in the N battery devices, a first end point of the ith battery device is connected with a second end point of the (i-1) th battery device, and a second end point of the ith battery device is connected with a first end point of the (i + 1) th battery device, wherein i is a positive integer and 1< i < N.

2. The battery system of claim 1, wherein a first terminal of a first battery device and a second terminal of an nth battery device of the series of N battery devices are used as charging ports of the battery system.

3. The battery system of claim 1 or 2, wherein the first switch is a bidirectional switch.

4. The battery system of claim 1 or 2, wherein the first switch comprises a fuse or a fuse.

5. The battery system of any of claims 1-4, wherein the first capacitor is a non-polar capacitor.

6. The battery system of any of claims 1-5, further comprising a first controller configured to bypass the first battery by the first capacitor by controlling the first switch within each failed battery device when there is at least one failed battery device of the N battery devices.

7. The battery system according to any one of claims 1 to 6, wherein the first terminal of the first battery device and the second terminal of the Nth battery device of the N battery devices are used as output ports for supplying high voltage power.

8. The battery system according to any one of claims 1 to 7, wherein the first and second terminals of each of the N battery devices are used as output ports for providing low voltage power.

9. The battery system of claim 8, further comprising a second controller configured to control the first switch to bypass the first battery by the first capacitor within the battery device corresponding to each failed external load when an external load of at least one of the low-voltage-powered output ports fails.

10. A motor drive device characterized by comprising: at least one inverter and a battery system according to any of claims 1-9, the at least one inverter being connected to at least one of the output ports providing low voltage in the battery system.

11. The motor drive of claim 10, wherein the at least one inverter is at least two single-phase H-bridge inverters;

and the first end point and the second end point of each battery device in the N battery devices are used as output ports for providing low-voltage power supply and are respectively connected with one single-phase H-bridge inverter in the at least two single-phase H-bridge inverters.

12. The motor drive of claim 10, wherein the at least one inverter is at least 4 three-phase full-bridge inverters;

and the first end point and the second end point of each battery device in the N battery devices are used as output ports for providing low-voltage power supply, and the two three-phase full-bridge inverters in the at least 4 three-phase full-bridge inverters are respectively connected.

13. A motor drive device characterized by comprising: at least one high voltage consumer and the battery system according to any of claims 1-9, wherein a first end of a first battery device and a second end of an nth battery device of the N battery devices are used as output ports for providing high voltage power, and wherein the at least one high voltage consumer is connected to the output ports for providing high voltage power in the battery system.

14. A power supply control method for a battery system according to any one of claims 1 to 9, comprising:

when there is at least one failed battery device among the N battery devices, the first battery is bypassed by the first capacitor by turning off the first switch within each failed battery device.

15. A power supply control method for a battery system according to any one of claims 1 to 9, comprising:

when at least one external load of the output port with low-voltage power supply has a fault, the first battery is bypassed by the first capacitor by turning off the first switch in the battery device corresponding to each external load with the fault.