WO2021218813A1

WO2021218813A1 - Battery system, electric motor driving device and power supply control method

Info

Publication number: WO2021218813A1
Application number: PCT/CN2021/089309
Authority: WO
Inventors: 程洋; 章雪亮
Original assignee: 华为数字能源技术有限公司
Priority date: 2020-04-30
Filing date: 2021-04-23
Publication date: 2021-11-04
Also published as: CN111628538A

Abstract

Disclosed are a battery system, an electric motor driving device and a power supply control method. The battery system comprises N battery devices connected in series, wherein each battery device comprises a first battery, a first capacitor, a first switch, a first end point and a second end point. If the first battery fails, since the first end point is connected to a first end of the first capacitor and a first end of the first switch, the second end point 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 battery is bypassed by the first capacitor by controlling the first switch. In the N battery devices, a first end point of an ith battery device is connected to a second end point of an (i-1)th battery device, and a second end point of the ith battery device is connected to a first end point of an (i+1)th battery device, wherein i is a positive integer and 1 < i < N. The battery system can continue to discharge, and has a fault-tolerance capability and relatively high reliability.

Description

Battery system, motor drive device and power supply control method

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010364326.8, and the invention title is "a battery system, a motor drive device, and a power supply control method" on April 30, 2020, the entire content of which is incorporated by reference Incorporated in this application.

Technical field

This application relates to the field of batteries, and in particular to a battery system, a motor drive device, and a power supply control method.

Background technique

With the development of the new energy field, batteries (also known as power batteries) are used more and more frequently, and their safety performance requirements are getting higher and higher. Currently, multiple batteries are directly connected in series to form a whole battery pack to supply power to electrical equipment such as motors in electric vehicles.

However, during the use of the battery, due to heat dissipation and other reasons, failures, such as short circuits, are extremely prone to occur. Since the batteries in the battery pack are connected in series, when a battery is short-circuited, it may cause the battery to catch fire, and the failure will spread throughout the battery pack. It can be seen that the current battery system does not have fault tolerance and has low reliability.

Summary of the invention

The embodiments of the present application provide a battery system, a motor drive device, and a power supply control method, which are used to prevent the failure from spreading and ensure the continuous operation of the battery system when the battery fails.

In the first aspect, this application proposes a battery system, including:

N battery devices connected in series, each of the N battery devices includes a first battery, a first capacitor, a first switch, a first terminal, and a second terminal. The first terminal is connected to the first terminal of the first capacitor. Terminal and the first terminal of the switch, the second terminal is connected to the second terminal of the first capacitor and the second terminal of the first battery, and the second terminal of the first switch is connected to the first terminal of the first battery, where N is greater than A positive integer of 1. Among the N battery devices, the first terminal of the i-th battery device is connected to the second terminal of the i-1th battery device, and the second terminal of the i-th battery device is connected to the second terminal of the i+1th battery device. One end is connected, where i is a positive integer and 1<i<N.

When the battery system is discharging, if the first battery of a certain battery device fails, because the battery device includes the first battery, the first switch, the first capacitor, the first terminal and the second terminal, the first terminal is connected to the second terminal. The first terminal of a capacitor and the first terminal of the first switch, the second terminal connects the second terminal of the first capacitor and the second terminal of the first battery, the second terminal of the first switch and the first terminal of the first battery Connected, the first switch can be turned off to form an open circuit of the first battery to prevent the fault from spreading, and since the battery system includes N battery devices connected in series, the current can pass through the first capacitor, so that the battery system can pass through other The battery device continues to discharge, and such a battery system has fault tolerance and high reliability.

In some possible implementations, among the N battery devices connected in series, the first terminal of the first battery device and the second terminal of the Nth battery device are used as the charging ports of the battery system, and the first switch is bidirectional Switch, the first capacitor is a non-polar capacitor, then the battery system can be discharged or charged.

In some possible implementations, among the N battery devices, the first terminal and the second terminal of each battery device are used as output ports for providing low-voltage power supply, so the battery system can be used for N low-voltage electrical equipment at the same time. Provide direct current.

In some possible implementations, the first switch is a fuse or a fuse, so that when the first battery is short-circuited, the current that flows is likely to exceed a certain value, and there is no need to send a shutdown signal to it. The first switch will automatically Shut down.

In some possible implementation manners, the battery system further includes a first controller, and the first controller is used for when there is at least one failed battery device among the N battery devices, in each failed battery device, through The first switch is controlled to bypass the first battery by the first capacitor, so that the battery system can continue to discharge through other battery devices. Such a battery system has fault tolerance and high reliability.

In some possible implementations, the battery system further includes a second controller, the second controller is used to when at least one of the external load of the low-voltage power supply output port fails, in each of the failed external load corresponding to the battery device Inside, the first battery is bypassed by the first capacitor by controlling the first switch, so that the battery system can continue to supply power to other external loads through other battery devices. Such a battery system has fault tolerance and high reliability.

In some possible implementations, among the N battery devices, the first terminal of the first battery device and the second terminal of the Nth battery device are used as output ports for providing high-voltage power, so the battery system can be high-voltage Electric equipment provides direct current.

In some possible implementations, the first switch is a mechanical switch or a mechanical switch or a metal-oxide-semiconductor field-effect transistor (MOSFET) switch. When the battery fails, it can switch to the MOSFET Send a shutdown signal.

In some possible implementations, the MOSFET switch is a MOSFET, and the current conduction direction of the MOSFET switch is the current direction when the battery is discharged. The MOSFET can only be energized in one direction and cannot be energized in the other direction, and the first capacitor is There are polar capacitors. The current conduction direction of the first capacitor is the current direction when the battery is discharged. The polar capacitors can only be energized from one direction and cannot be energized in the other direction, so that the battery system can be discharged but cannot be charged.

In some possible implementations, the MOSFET switch is two MOSFETs connected in series, and the current conduction directions of the two MOSFETs are opposite, and the current conduction directions of the two MOSFETs are opposite, which can realize bidirectional energization. The first capacitor is a non-polar capacitor. , The capacitor can realize two-way energization, so that the battery system can be discharged and recharged.

In some possible implementations, the first battery can 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 first controller, so that the first controller determines that the first battery is faulty. , The first controller will send a turn-off signal to the first switch. In some possible implementations, the current sensor may be a part of the first switch, or may be an independent element, which is not limited here.

In the second aspect, this application proposes a motor drive device, including at least one inverter and the battery system as described in the first aspect. Among the N battery devices in the battery system, the first terminal of each battery device is connected to The second end point is used as an output port for providing low-voltage power supply, wherein at least one inverter is connected to at least one output port for providing low-voltage power supply in the battery system, so that the motor drive device can provide AC power.

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

In some possible implementations, at least one inverter is at least 4 three-phase full-bridge inverters. Among the N battery devices, the first terminal and the second terminal of each battery device are used to provide low-voltage power supply. The output ports are respectively connected to the two three-phase full-bridge inverters among at least four three-phase full-bridge inverters, so that the battery system can provide three-phase alternating current for multiple three-phase motors.

In the third aspect, the present application proposes a motor drive device, including at least one high-voltage electrical equipment and the battery system as described in the first aspect. Among the N battery devices in the battery system, the first battery device is The end point and the second end point of the Nth battery device are used as the output port for providing high-voltage power supply, and at least one high-voltage electrical device is connected to the output port for providing high-voltage power supply in the battery system, then the battery system can supply the high-voltage power supply The equipment provides direct current.

In some possible implementation manners, in some possible implementation manners, the high-voltage electrical equipment may be an air conditioner or a positive temperature coefficient (PTC) heater, so that the power supply of the air conditioner and/or the PTC heater is more stable.

In some possible implementations, at least one inverter is a three-phase full-bridge inverter. Among the N battery devices connected in series, the first terminal of the first battery device and the second terminal of the Nth battery device The endpoints are used as output ports to provide high-voltage power supply, respectively connected to a three-phase full-bridge inverter, so that the battery system can provide high-voltage AC power.

In a fourth aspect, the present application proposes a power supply control method, which is used in the battery system as described in the first aspect, the battery system further includes a first controller, and the first controller is used when there is at least one of the N battery devices When a faulty battery device occurs, in each faulty battery device, the first battery is bypassed by the first capacitor by controlling the first switch, and the method includes:

Monitor each of the N battery devices. When there is at least one battery device that has failed in the N battery devices, in each battery device that has failed, the first battery is controlled by controlling the first switch. Bypassed by the first capacitor, it forms an open circuit of the first battery to prevent the fault from spreading, and because the current passes through the first capacitor, the battery system can continue to discharge through other battery devices. Such a battery system has fault tolerance and is more reliable. high.

In the fifth aspect, this application proposes a power supply control method, the method is used in the battery system as described in the first aspect, the battery system further includes a second controller, the second controller is used when at least one low-voltage power output port When the external load 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. The method includes:

Monitor the external load of each low-voltage power supply output port in the N battery devices. When the external load of at least one low-voltage power supply output port fails, within the battery device corresponding to each failed external load, By controlling the first switch to bypass the first battery by the first capacitor, an open circuit of the first battery is formed to prevent the fault from spreading, and because the current passes through the first capacitor, the battery system can continue to discharge through other battery devices. The battery system has fault tolerance and high reliability.

It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

When the battery system is discharging, if the 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 terminal and the second terminal, the first battery One end is connected to the first end of the first capacitor and the first end of the switch, the second end 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 second end of the first battery. If the first terminal is connected, the first switch can be turned off to form a disconnection of the first battery to prevent the failure from spreading. And because the battery system includes N battery devices connected in series, the first terminal of the i-th battery device is connected to the second terminal of the i-1th battery device, and the second terminal of the i-th battery device is connected to the i+th battery device. The first terminal of a battery device is connected, where i is a positive integer and 1<i<N, then the current can pass through the first capacitor, so that the battery system can continue to discharge through other battery devices, such a battery system is fault-tolerant Ability and reliability are high.

Description of the drawings

Figure 1 is a schematic diagram of a battery pack in which multiple batteries are connected in series;

Figure 2-1 is a schematic diagram of an embodiment of a battery system proposed in this application;

Figure 2-2 is a schematic diagram of an embodiment of a battery device proposed in this application;

Figure 2-3 is a schematic diagram of an embodiment in which the first battery in the battery device fails;

Figures 2-4 are schematic diagrams of embodiments of four battery devices connected in series;

Figure 2-5 is a schematic diagram of an embodiment in which the battery system keeps discharging when a fault occurs;

Figure 2-6 is a schematic diagram of an embodiment of a battery system proposed in this application;

Figure 2-7 is a schematic diagram of an embodiment of two MOSFETs connected in series;

Figure 2-8 is a schematic diagram of another embodiment of a four battery device connected in series

2-9 is a schematic diagram of an embodiment of connection mode 1 between the battery system and the electrical equipment;

Figure 2-10 is a schematic diagram of an embodiment of connection mode 2 between the battery system and the electrical equipment;

2-11 is a schematic diagram of an embodiment of a battery system proposed in this application;

2-12 is a schematic diagram of an embodiment of the connection between the battery device and the electrical equipment;

2-13 is a schematic diagram of an embodiment of the connection mode 3 between the battery system and the electric equipment;

Figure 2-14 is a schematic diagram of the current path where the first battery fails when the battery device is being charged;

Figure 2-15 is a schematic diagram of the current path where the first battery fails when the battery system is charging;

Figure 3-1 is a schematic diagram of an embodiment of a motor drive device proposed in this application;

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

Figure 3-3 is a schematic diagram of a single-phase H-bridge inverter;

Figure 3-4 is a schematic diagram of an embodiment in which each of the N battery devices is connected to an inverter;

Figures 3-5 are schematic diagrams of an embodiment in which each of the N battery devices is connected to two inverters;

Figure 3-6 is a schematic diagram of two inverter carriers;

Figure 3-7 is a schematic diagram of an embodiment in which an inverter is connected in parallel in a battery system;

Figure 4-1 is a schematic diagram of an embodiment of an electric vehicle provided by this application;

Figure 4-2 is a schematic diagram of an embodiment in which the motor drive device is connected to the motor;

Figure 4-3 is a schematic diagram of another embodiment in which the motor drive device is connected to the motor;

Figure 4-4 is a schematic diagram of another embodiment in which the motor drive device is connected to the motor;

Figure 4-5 is a schematic diagram of an embodiment in which a motor drive device in an electric vehicle is connected to an air conditioner and/or a PTC heater;

FIG. 5-1 is a schematic diagram of an embodiment of a motor drive device also provided by this application;

Figure 5-2 is a schematic diagram of an embodiment where the high-voltage electrical equipment is an air conditioner and/or a PTC heater;

Figure 5-3 is a schematic diagram of an embodiment in which the high-voltage electrical equipment is a three-phase full-bridge inverter;

FIG. 6 is a schematic diagram of an embodiment of a power supply control method provided by this application;

FIG. 7 is a schematic diagram of an embodiment of a power supply control method further provided by this application.

Detailed ways

With the development of the new energy field, batteries (also known as power batteries) are used more and more frequently, and their safety performance requirements are getting higher and higher. Currently, multiple batteries are mainly connected in series to form a whole battery pack to supply power to electrical equipment such as motors in electric vehicles. Specifically, as shown in Fig. 1, a plurality of batteries are connected in series to form a whole battery pack, which is used to provide direct current to the inverter, and the inverter converts the direct current to alternating current to provide alternating current to the motor. It should be noted that the battery pack can be discharged or recharged.

To this end, this application proposes a battery system. Please refer 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 i-th battery device 210 is connected to the second terminal 215 of the i-1th battery device 210, and the second terminal 215 of the i-th battery device 210 It is connected to the first terminal 214 of the i+1th battery device 210, where i is a positive integer and 1<i<N.

As shown in FIG. 2-2, each 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 Point 214 connects the first terminal of the first capacitor 212 and the first terminal of the first switch 213, the second terminal 215 connects the second terminal of the first capacitor 212 and the second terminal of the first battery 211, and the second terminal of the first switch 213 The two ends are connected to the first end of the first battery 211, where N is a positive integer greater than one.

In the embodiment of the present application, when the battery system 200 is discharged, in the battery device 210, currents respectively pass through two parallel paths. One path is the first switch 213 and the first battery 211 in series, and the other path is the second path. A capacitor 212. As shown in Figure 2-3, when the first battery 211 fails, the first switch 213 is turned off, and the path of the series-connected first switch 213 and the first battery 211 is not passable, so the current can still pass through another path , That is, flow from the second terminal 215 to the first terminal 214 through the first capacitor 212, and the battery-maintaining device 210 can maintain the conduction on the premise that the first battery 211 is turned off.

As shown in FIGS. 2-4, the battery system 200 is described by taking four battery devices 210 connected in series as an example. The four battery devices 210 are battery device 1, battery device 2, battery device 3, and battery device 4, respectively. The second terminal 215 of the battery device 1 is connected to the first terminal 214 of the battery device 2, the second terminal 215 of the battery device 2 is connected to the first terminal 214 of the battery device 3, and the second terminal 215 of the battery device 3 is connected to the battery device 4的first terminal 214. Then, since the battery device 210 can be kept on when the first battery 211 is turned off, the battery system 200 keeps discharging as shown in FIGS. 2-5.

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

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

When the battery system 200 is discharged, the direction of the current passing through the first capacitor 212 is from the second terminal 215 to the first terminal 214. If the first capacitor 212 is a polarized capacitor, then the first capacitor 212 is shown in FIG. 2- The current flow direction in 2 should also be from the second end 215 to the first end 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 discharging, if there is no battery failure, 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 fails, then As shown in FIG. 2-3, the first switch 213 enters the off state, that is, the path of the first battery 211 is shut off, so that the failure of the first battery 211 will not spread.

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

Specifically, the first controller 220-1 and the first switch 213 may be connected wirelessly or wiredly, which is not limited here. When the first controller 220-1 sends a turn-on signal to the first switch 213, the first switch 213 will enter a turn-on state; when the first controller 220-1 sends a turn-off signal to the first switch 213, the first switch 213 A switch 213 will be turned on. In some possible implementations, the on signal may be 1, and the off signal may be 0, or other types of signals, which are not limited here.

In some possible implementations, the first battery 211 may be connected in series with a current sensor. When the current exceeds the threshold, the current sensor will send a current overload signal to the first controller 220-1, so that the first controller 220-1 If it is determined that the first battery 211 is faulty, the first controller 220-1 will send 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 may be an independent element, which is not limited here.

It should be noted that a mechanical switch is an electronic component that can open a circuit or interrupt current. The mechanical switch has two states, namely "closed" and "open". Among them, "closed" means allowing current to flow, that is, conducting; "open" means not allowing current to flow, that is, turning off. In the embodiment of the present application, the mechanical switch may include a signal receiver. When receiving the on signal, the mechanical switch enters the "closed" state, and when receiving the off signal, the mechanical switch enters the "open" state.

MOSFET switch is composed of MOSFET, which is a switch constructed by using the principle of MOSFET gate to control MOSFET source and drain on and off. In the embodiment of the present application, the MOSFET switch can be connected through the first controller 220-1, and the MOSFET switch can 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 can be a unidirectional switch or a bidirectional switch, which is not limited here. It should be noted that when the MOSFET switch is a unidirectional switch, it consists of one MOSFET, and this MOSFET can only be energized from one direction, and cannot be energized in the other direction. When the MOSFET switch is a two-way switch, as shown in Figure 2-7, it is composed of two MOSFETs connected in series. The current conduction directions of the two MOSFETs are opposite, which can realize bidirectional energization. As shown in Fig. 2-2, when the battery system 200 is discharged, the direction of the current passing through the first switch 213 is from the second terminal 215 to the first terminal 214. Therefore, if the MOSFET switch is a unidirectional switch, it is shown in Fig. 2 The current passing direction of the first switch 213 in -2 should also be from the second end 215 to the first end 214.

In some possible implementations, the first controller 220-1 may be a microcontroller unit (MCU), also known as a single chip microcomputer (single chip microcomputer) or a single-chip microcomputer. , CPU) frequency and specifications are appropriately reduced, and peripheral interfaces such as memory (memory), counter (timer), universal serial bus (USB), and analog-to-digital conversion (A/D) are all integrated into a single On the chip, a chip-level computer is formed to perform different combination controls for different applications.

In some possible implementations, the first switch 213 may also be an uncontrollable switch, such as a fuse or a fuse. When the voltage of the passing current exceeds a certain value, the fuse or the fuse will be automatically turned off without sending a switch to it. Signal off.

In the embodiment of the present application, when the battery system 200 is connected to the electric device, it can supply power to the electric device. It should be noted that the electrical equipment can be a motor, a PTC heater or an air conditioner, which is not limited here. Specifically, the connection manner between the battery system 200 and the electrical equipment may include multiple manners, and three manners of connection between the battery system 200 and the electrical equipment are listed below as examples.

It should be noted that in the following various examples of the battery system 200 and electrical equipment, the battery system 200 has four battery devices 210 as an example for description. As shown in FIGS. 2-8, the battery system 200 includes batteries connected in series. Device 1, battery device 2, battery device 3, and battery device 4, wherein the second terminal of battery device 1 is connected to the first terminal of battery device 2, and the second terminal of battery device 2 is connected to the first terminal of battery device 3. , The second end of the battery device 3 is connected to the first end of the battery device 4.

Connection method 1: Among the N battery devices, the first terminal of the first battery device and the second terminal of the Nth battery device are used as output ports for providing high-voltage power supply. As shown in Figures 2-9, among the four battery devices 210 connected in series, the first battery device 210 is the battery device 1, and the fourth battery device 210 is the battery device 4. Then the first terminal and the battery of the battery device 1 can be used respectively. The second terminal of the device 4 serves as the first terminal and the second terminal of the battery system 200 respectively, and is used as an output port for providing high-voltage power supply, respectively connected to the electrical equipment, and provides direct current for the electrical equipment.

Connection mode 2: Among 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 Figure 2-10, each battery device 210 of the four battery devices 210 connected in series can also be independently connected to their respective electrical equipment through the first terminal 214 and the second terminal 215, so that each is a respective electrical device. Provide low-voltage direct current. It should be noted that, in FIGS. 2-10, each battery device 210 is exemplarily connected to the electrical equipment through a line, which means that the battery device 210 and the electrical equipment have established a closed energization circuit, so that the battery device 210 can be used for electricity. Equipment power supply. Specifically, at the level of the battery device 210, the connection between the battery device 210 and the electrical equipment may be as shown in FIGS. 2-12, and the battery device 210 supplies power to the electrical equipment through a closed energization loop.

In some possible implementations, as shown in FIG. 2-11, the battery system 200 further includes a second controller 220-2, and the second controller 220-2 is used as an external load for at least one low-voltage power supply output port. (For example: the electrical equipment shown in Figure 2-10) When a fault occurs, in the battery device 210 corresponding to each external load that has the fault, the first battery 211 is replaced by the first capacitor by controlling the first switch 213 212 bypass. In some possible implementation manners, the external load may be an inverter, a motor, an air conditioner, a PTC heater, etc., which is not limited here.

In some possible implementations, the external load can be connected in series with a current sensor. 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 can determine the external If the load fails, 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 the external load, or may be an independent component, which is not limited here.

In other possible implementation manners, as shown in Figs. 2-13, each of the N battery devices 210 can also connect the first terminal 214 and the second terminal 215 to the electric device, respectively, so that each battery device 210 is Power supply from the same electrical equipment. It should be noted that the electric device is a device that can receive multiple power sources at the same time. Similarly, in FIGS. 2-13, each battery device 210 is connected to the electrical equipment through a line, which is only an example, indicating that the battery device 210 and the electrical equipment have established a closed path, so that the battery device 210 can be used for electrical equipment. The device provides direct current, so I won’t go into details here.

In some possible implementation manners, there are other connection manners between the battery system 200 and the electrical equipment, which are not limited here.

In some possible implementations, the battery system 200 can not only discharge, but also charge. Among 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 the charging port of the battery system 200, and the charging port of the battery system 200 passes through Connect the DC bus, the DC bus is connected to the power supply and N battery devices are connected in series to charge the N battery devices.

It should be noted that the current direction of the battery system 200 during charging and discharging is opposite. In FIG. 2-2, the current direction of the battery device 210 during charging is from the first end 214 to the second end 215. Similarly, the current passes through the left and right sides respectively, where one side is the first battery 211 and the first switch 213, and the other side is the first capacitor 212. In order for the battery device 210 to be charged smoothly, the first switch 213 and the first capacitor 212 need to be energized in the direction from the first terminal 214 to the second terminal 215. Then, in the embodiment of the present application, the first switch 213 and the first capacitor 212 All the first capacitors 212 must be bidirectionally conductive. The bidirectional switch is a bidirectional switch, including a mechanical switch and two MOSFETs connected in series, wherein the current conduction directions of the two MOSFETs are opposite. The bidirectional first capacitor 212 is a non-polar capacitor, that is, a capacitor that can realize bidirectional energization.

Specifically, as shown in Figure 2-7, it is a schematic diagram of two MOSFETs connected in series. The two MOSFETs are respectively S1 and S2, where the current conduction directions of S1 and S2 are opposite. The MOSFET switch composed of two MOSFETs connected in series has two effective working states: on and off. Specifically, when both S1 and S2 are applied with on signals, the bidirectional switch is in the on state, and the battery device 210 can be discharged. It can also be charged. When both S1 and S2 are applied with the turn-off signal, the bidirectional switch is in the turn-off state, then during charging, current will flow through the first capacitor 212, so that the battery system 200 can continue to be charged. In some possible implementations, if S1 is on and S2 is off, then the current direction is from S1 to S2; if S1 is off and S2 is on, then the current direction is from S2 to S1.

As shown in Figure 2-14, when the first battery 211 fails, the first switch 213 is turned off, and the path of the series-connected first switch 213 and the first battery 211 is not feasible, so the current can still pass through another path. That is, the first capacitor 212 realizes the flow from the first terminal 214 to the second terminal 215.

Then, if the battery device 1 shown in Figs. 2-15 fails, the battery system 200 will not stop discharging as a result, but the first switch 213 is turned off, so that the current bypasses the first battery 211 in the battery device 1 , And only pass through the first capacitor 212 in the battery device 1, so the battery system 200 can continue to be charged, so that the battery system 200 has fault tolerance and higher reliability.

The above describes how the battery system 200 continues to work when individual batteries fail during discharging and charging, that is, to continue to provide direct current. However, some devices require AC power, such as a motor. Therefore, when the battery system 200 supplies power to the motor, an inverter needs to be connected. The inverter converts the DC power to AC power so that the motor can be driven.

To this end, please refer to FIG. 3-1. The present application also provides a motor drive device 300, which includes at least one inverter 310 and the above-mentioned battery system 200, at least one inverter 310 is connected to the battery system 200 At least one output port that provides low-voltage power supply.

The inverter 310 is a converter that converts direct current to alternating current, and is composed of an inverter bridge, control logic, and filter circuit, and is widely used, such as motors and household appliances. Common inverters 310 include three-phase full-bridge inverters and single-phase H-bridge inverters. Among them, the three-phase full-bridge inverter is shown in Figure 3-2, which is used to convert DC power to three-phase AC power for electrical equipment, and the single-phase H-bridge inverter is shown in Figure 3-3, which is used for The electrical equipment converts direct current into single-phase alternating current.

In the embodiment of the present application, there may be many types of the inverter 310 and the corresponding connection manner to the battery system 200, and three of them are described below with examples. It should be noted that the following examples are only examples and are not limited.

Connection method 1: At least one inverter 310 is at least two single-phase H-bridge inverters. Among the N battery devices 210, the first terminal 214 and the second terminal 215 of each battery device 210 are used to provide low voltage The output ports of the power supply are respectively connected to one of the at least two single-phase H-bridge inverters.

Specifically, as shown in FIGS. 3-4, each battery device 310 of the four battery devices 210 is connected in parallel with an inverter 310, so the inverter 310 is usually a single-phase H-bridge inverter. Then, each inverter 310 can provide single-phase alternating current. For example, the number of N battery devices 210 is 4, and each battery device 210 is respectively connected to an inverter 310, a total of 4 inverters 310, then such a motor drive device can provide 4-phase current for driving multiple phases Motor. In some possible implementations, the at least one inverter 310 may also be a three-phase full-bridge inverter. Then, such a motor drive device can provide four 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 drive device 300 has fault tolerance and high reliability.

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

Specifically, as shown in FIGS. 3-5, each of the four battery devices 210 is connected in parallel with two inverters 310 respectively. The inverter 310 is a three-phase full-bridge inverter. Then, such a motor drives The 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 drive device 300 has fault tolerance and high reliability.

In some possible implementations, in each battery device 210, the first battery 211 supplies power to two three-phase full-bridge inverters (1# inverter and 2# inverter respectively), and two The pulse width modulation (PWM) carrier of the three-phase full-bridge inverter is mutually offset by 90°, forming two inverter carriers as shown in Figure 3-6. When they form a modulation wave, the bus voltage can be reduced The ripple and the ripple current flowing through the first capacitor 212.

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

Connection mode 3: At least one inverter 310 is a three-phase full-bridge inverter. Among the N battery devices 210 connected in series, the first port 214 of the first battery device 210 and the second port 214 of the Nth battery device 210 Port 215 is used as an output port to provide high-voltage power supply, respectively connected to a three-phase full-bridge inverter.

Specifically, as shown in FIGS. 3-7, among the four battery devices of the battery system 200, the first port 214 of the first battery device 210 and the second port 215 of the fourth battery device 210 are used to provide high-voltage power supply. The output ports of are respectively connected to the inverter 310, so that the battery system 200 provides high-voltage direct current for 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 drive device 300 has fault tolerance and high reliability. The inverter 310 in connection mode 1 may be a three-phase full-bridge inverter or a single-phase H-bridge inverter, which is not limited here.

Please refer to FIG. 4-1. The present application also provides an electric vehicle 400, which includes a motor 410 and the motor drive device 300 described above.

It should be noted that the motor 410 can also be connected to one inverter 310 or multiple inverters 310. The inverter 310 can be connected to a three-phase full-bridge inverter or a single-phase H-bridge inverter. The device is not limited here. In the embodiment of the present application, the motor 410 may be a multi-three-phase motor or a multi-phase motor. The motor 410 and the inverter 310 need to be matched before they can be connected. Specifically, what types of motors 410 need to be used for different types of inverters 310 are described below.

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 Figure 4-4, the motor 410 is connected to an inverter 310. 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, then the motor 410 is a single-phase motor.

In some possible implementation manners, as shown in FIGS. 4-5, the electric vehicle 400 further includes: an air conditioner and/or a PTC heater 420, and the air conditioner and/or PTC heater 420 is connected in parallel with the battery system 200 in the motor drive device 300 , So that the battery system 200 can not only provide AC power to the motor 410, but also provide DC power to the air conditioner and/or the PTC heater 420. It should be noted that the air conditioner and/or the PTC heater 420 are only examples, and may also be other equipment, which is not limited here. In some possible implementations, the air conditioner and/or PTC heater 420 may be connected to the DC bus when the battery system 200 is not charging, and the air conditioner and/or PTC heater 420 can be provided with high voltage power supply through the DC bus.

Please refer to FIG. 5-1. The present application also provides a motor drive device 500, including: at least one high-voltage electrical device 510 and the above-mentioned battery system 200, at least one high-voltage electrical device 510 is connected to the battery system 200 The output port that provides high-voltage power supply.

As shown in FIG. 5-2, in some possible implementation manners, the high-voltage electrical equipment 510 may be an air conditioner and/or a PTC heater. In some possible implementations, the air conditioner and/or the PTC heater may be connected to the DC bus when the battery system 200 is not charging, and the air conditioner and/or the PTC heater can be provided with high voltage power supply through the DC bus.

In some possible implementations, the high-voltage electrical equipment 510 may be a three-phase full-bridge inverter. As shown in Figure 5-3, among 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 supply. , Respectively connect the three-phase full-bridge inverter. Among the four battery devices of the battery system 200, the first terminal 214 of the first battery device 210 and the second terminal 215 of the fourth battery device 210 are used as output ports for providing high-voltage power supply, respectively connected to a three-phase full bridge The inverter enables the battery system 200 to provide 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 drive device 300 has fault tolerance and high reliability.

Please refer to FIG. 6, the present application also 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 used for When there is at least one failed battery device 210 among the N battery devices 210, in each of the failed battery devices 210, the first battery 211 is bypassed by the first capacitor 212 by controlling the first switch 213. Methods include:

601. Determine that at least one of the N battery devices 210 has a faulty battery device 210.

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

In this embodiment, the method flow of

steps

601 and 602 is similar to the method steps executed by the first controller 220-1 in FIGS. 2-6, and will not be repeated here. It should be noted that the method flow of

steps

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

Please refer to FIG. 7, the present application also provides a power supply control method for the battery system 200 as described above, wherein the battery system 200 further includes a second controller 220-2, and the second controller 220-2 is used for When the external load of at least one low-voltage power supply output port fails, the first battery 211 is bypassed by the first capacitor 212 by controlling the first switch 213 in the battery device 210 corresponding to each external load that has failed. The method includes:

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

702. In the battery device 210 corresponding to each external load that has a fault, the first battery 211 is bypassed by the first capacitor 212 by turning off the first switch 213.

In this embodiment, the method flow of

steps

701 and 702 is similar to the method steps executed by the second controller 220-2 in FIG. 2-11, and will not be repeated here. It should be noted that the method flow 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 here. In some possible implementations, the first switch 213 may also be a fuse or a fuse. In the battery device 210 that has a fault, the first switch 213 is turned off due to current overload.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the application and the above-mentioned drawings are not used to describe a specific sequence or sequence. order. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in a sequence other than the content illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive solutions. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those clearly listed. Steps or units, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products, or equipment.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or integrated. To another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In summary, the above embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

A battery system, characterized in that it comprises:

N battery devices connected in series, each of the N battery devices includes a first battery, a first capacitor, a first switch, a first end and a second end, and the first end is connected to the The first terminal of the first capacitor and the first terminal of the first switch, and the second terminal is connected to the second terminal of the first capacitor and the second terminal of the first battery. The second end is connected to the first end of the first battery, where N is a positive integer greater than 1;

Among the N battery devices, the first terminal of the i-th battery device is connected to the second terminal of the i-1th battery device, and the second terminal of the i-th battery device is connected to the i+1th battery device The first end of is connected, where i is a positive integer and 1<i<N.
The battery system according to claim 1, wherein among the N battery devices connected in series, the first terminal of the first battery device and the second terminal of the Nth battery device are used as the battery The charging port of the system.
The battery system according to claim 1 or 2, wherein the first switch is a bidirectional switch.
The battery system according to claim 1 or 2, wherein the first switch comprises a fuse or a fuse.
The battery system according to any one of claims 1 to 4, wherein the first capacitor is a non-polar capacitor.
The battery system according to any one of claims 1-5, wherein the battery system further comprises a first controller, and the first controller is configured to: when at least one of the N battery devices fails In the battery device of the battery device, in each battery device that fails, the first battery is bypassed by the first capacitor by controlling the first switch.
The battery system according to any one of claims 1 to 6, wherein among the N battery devices, the first terminal of the first battery device and the second terminal of the Nth battery device are used as Provide output port for high voltage power supply.
7. The battery system according to any one of claims 1-7, wherein among the N battery devices, the first terminal and the second terminal of each battery device are used as output ports for providing low-voltage power supply.
The battery system according to claim 8, wherein the battery system further comprises a second controller, and the second controller is configured to: In the battery device corresponding to each external load that has a fault, the first battery is bypassed by the first capacitor by controlling the first switch.
A motor drive device, comprising: at least one inverter and the battery system according to any one of claims 1-9, and the at least one inverter is connected to at least one of the battery systems. The output port that provides low-voltage power is described.
The motor drive device according to claim 10, wherein the at least one inverter is at least two single-phase H-bridge inverters;

Among the N battery devices, the first terminal and the second terminal of each battery device are used as output ports for providing low-voltage power supply, and are respectively connected to one of the at least two single-phase H-bridge inverters. H-bridge inverter.
The motor drive device according to claim 10, wherein the at least one inverter is at least 4 three-phase full-bridge inverters;

Among the N battery devices, the first terminal and the second terminal of each battery device are used as output ports for providing low-voltage power supply, and are respectively connected to two three-phase inverters of the at least four three-phase full-bridge inverters. Phase full bridge inverter.
A motor drive device, characterized by comprising: at least one high-voltage electrical equipment and the battery system according to any one of claims 1-9, and among the N battery devices, the first battery device of the first battery device The end point and the second end point of the Nth battery device are used as an output port for providing high-voltage power supply, and the at least one high-voltage electric device is connected to the output port for providing high-voltage power supply in the battery system.
A power supply control method, characterized in that the method is used in the battery system according to any one of claims 1-9, and comprises:

When there is at least one failed battery device among the N battery devices, in each failed battery device, the first battery is bypassed by the first capacitor by turning off the first switch. road.
A power supply control method, characterized in that the method is used in the battery system according to any one of claims 1-9, and comprises:

When at least one external load of the low-voltage power supply output port fails, in the battery device corresponding to each external load that fails, the first battery is turned off by the first switch by turning off the first switch. One capacitor bypass.