Power battery high-voltage control unit and power battery system

Abstract

The utility model provides a power battery high-voltage control unit and a power battery system. The power battery high-voltage control unit comprises a bidirectional semiconductor switch module, a switch device and a driving circuit assembly, a first end of the bidirectional semiconductor switch module is connected with a first electrode of the power battery, a second end of the bidirectional semiconductor switch module is connected with one end of the high-voltage system, and a control end of the bidirectional semiconductor switch module is connected with the driving circuit assembly; the first end of the switching device is connected with the second electrode of the power battery, the second end of the switching device is connected with the other end of the high-voltage system, and the control end of the switching device is connected with the driving circuit assembly. By adopting the scheme, the cost can be saved, and the safety can be improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to a power battery high-voltage control unit and a power battery system. Background Art

[0002] During the startup of an electric vehicle, the vehicle will execute a high-voltage power-on process, which generally starts with pre-charging. After the pre-charging is completed, the high-voltage power-on is controlled to fully power the high-voltage system and wait for the driver to perform driving operations.

[0003] At present, the control of high-voltage power-on of power batteries generally involves setting a high-voltage DC contactor on the main circuit connecting the power battery to the high-voltage system, and setting a pre-charging circuit consisting of a pre-charging resistor, a pre-charging contactor, etc. on the bypass circuit to connect to the pre-charging capacitor. The pre-charging is controlled by controlling the on-off of the pre-charging contactor, and the high-voltage power-on is controlled by controlling the on-off of the high-voltage DC contactor. In addition, the use of fuses for short-circuit protection requires many devices and is costly. Utility Model Content

[0004] The present application provides a power battery high-voltage control unit and a power battery system to solve the above-mentioned technical problems in the prior art.

[0005] According to a first aspect of the present application, there is provided a power battery high-voltage control unit, comprising a bidirectional semiconductor switch module, a switch device, and a drive circuit assembly;

[0006] A first end of the bidirectional semiconductor switch module is connected to a first electrode of the power battery, a second end of the bidirectional semiconductor switch module is connected to one end of the high-voltage system, and a control end of the bidirectional semiconductor switch module is connected to the drive circuit assembly;

[0007] The first end of the switch device is connected to the second electrode of the power battery, the second end of the switch device is connected to the other end of the high-voltage system, and the control end of the switch device is connected to the drive circuit assembly.

[0008] In some embodiments, the switching device comprises a mechanical contactor;

[0009] During pre-charging, the driving circuit assembly drives the mechanical contactor to close and causes the bidirectional semiconductor switch module to operate in the amplification range;

[0010] When the high voltage is powered on, the driving circuit assembly drives the mechanical contactor to close and turns on the bidirectional semiconductor switch module;

[0011] When the high voltage is turned off, the driving circuit component turns off the bidirectional semiconductor switch module and controls the mechanical contactor to open.

[0012] In some embodiments, the driving circuit assembly further includes: a processing chip, a first driving circuit, and a second driving circuit;

[0013] One end of the first driving circuit is connected to the processing chip, and the other end is connected to the control end of the bidirectional semiconductor switch module;

[0014] One end of the second driving circuit is connected to the processing chip, and the other end is connected to the control end of the switching device.

[0015] In some embodiments, the drive circuit assembly further includes a current detection circuit, one end of which is connected to a connection line between the power battery and the high-voltage system, and the other end of which is connected to the processing chip;

[0016] When the current detected by the current detection circuit is greater than a threshold, the processing chip outputs a cutoff instruction to the first drive circuit, causing the first drive circuit to output a cutoff voltage to the control end of the bidirectional semiconductor switch module.

[0017] In some embodiments, the bidirectional semiconductor switch module includes any one of a bidirectional IGBT, a bidirectional MOS switch, and a bidirectional transistor.

[0018] In some embodiments, the bidirectional semiconductor switch module also includes an overcurrent protection circuit, and the first end of the bidirectional IGBT / the bidirectional MOS switch / the bidirectional triode is connected to the power battery through the overcurrent protection circuit, and / or the second end of the bidirectional IGBT / the bidirectional MOS switch / the bidirectional triode is connected to the high-voltage system through the overcurrent protection circuit.

[0019] In some embodiments, the power battery high-voltage control unit further includes a first protection circuit and / or a second protection circuit;

[0020] One end of the first protection circuit is connected to the control end of the bidirectional semiconductor switch module, and the other end is connected to the second end of the bidirectional semiconductor switch module;

[0021] One end of the second protection circuit is connected to the driving circuit component, and the other end is connected to the control end of the bidirectional semiconductor switch module.

[0022] In some embodiments, the power battery high-voltage control unit further includes a third protection circuit;

[0023] One end of the third protection circuit is connected to the control end of the bidirectional semiconductor switch module, and the other end is connected to the first end of the bidirectional semiconductor switch module.

[0024] In some embodiments, the switching device includes any one of a mechanical contactor, a bidirectional IGBT, a bidirectional MOS switch, and a bidirectional triode.

[0025] According to a second aspect of the present application, a power battery system is provided, comprising a power battery and the above-mentioned power battery high-voltage control unit, wherein the power battery is connected to the power battery high-voltage control unit.

[0026] In summary, the power battery high-voltage control unit and power battery system provided by this application have at least the following beneficial effects:

[0027] A bidirectional semiconductor switch module and a switch device are connected to the connection line between the power battery and the high-voltage system. The operation of the bidirectional semiconductor switch module and the switch device is driven by a driving circuit component to control the state of the bidirectional semiconductor switch module and the on-off of the switch device, thereby controlling the use of the power battery for pre-charging, connecting the high-voltage system to power on at high voltage, or disconnecting the high-voltage system to power off at high voltage. In this way, a semiconductor-type switch (bidirectional semiconductor switch module) is used instead of a traditional mechanical switch (high-voltage DC contactor) to achieve high-voltage power on and off and pre-charging control, which can eliminate the pre-charging circuit composed of pre-charging resistors, pre-charging contactors, etc. in the existing method, saving costs. Moreover, setting a bidirectional semiconductor switch module at one end connected to the power battery and a switch device at the other end can improve the reliability of high-voltage power on and off control. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the specific implementation methods of the present application, the following will briefly introduce the drawings required for use in the specific implementation methods in conjunction with the accompanying drawings. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings or solutions can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a structural diagram of a power battery high-voltage control unit in one embodiment of the present application;

[0030] Figure 2 is a switching characteristic curve diagram of a bidirectional semiconductor switch module;

[0031] Figure 3 This is a circuit structure diagram of a power battery high-voltage control unit in another embodiment of the present application;

[0032] Figure 4 This is a circuit structure diagram of a power battery high-voltage control unit in another embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the above and other features and advantages of the present application more clear, the present application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0034] In the following description, many specific details are set forth to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that it is not necessary to adopt the specific details to practice the present application. In other cases, well-known steps or operations are not described in detail to avoid obscuring the present application.

[0035] This application provides a power battery high voltage control unit, which can be used to control the power on and off of the power battery high voltage. Figure 1 The power battery high-voltage control unit includes a bidirectional semiconductor switch module 120, a switch device 130, and a drive circuit assembly 110. The bidirectional semiconductor switch module 120 includes a semiconductor switch capable of bidirectional switching control and may also include other peripheral circuits. The switch device 130 can be either a mechanical switch or a bidirectionally controlled semiconductor switch.

[0036] like Figure 1 As shown, the first end of the bidirectional semiconductor switch module 120 is connected to the first electrode A1 of the power battery, and the second end of the bidirectional semiconductor switch module 120 is connected to one end B1 of the high-voltage system; the control end of the bidirectional semiconductor switch module 120 is connected to the drive circuit assembly 110. The first end of the switch device 130 is connected to the second electrode A2 of the power battery, and the second end of the switch device 130 is connected to the other end B2 of the high-voltage system; the control end of the switch device 130 is connected to the drive circuit assembly 110.

[0037] The drive circuit assembly 110 controls the switching states of the bidirectional semiconductor switch module 120 and the switch device 130 by outputting voltages to the control terminals of the bidirectional semiconductor switch module 120 and the switch device 130, thereby controlling the connection state between the power battery and the high-voltage system and achieving high-voltage power-up and power-down of the power battery. Specifically, when pre-charging is required, the drive circuit assembly 110 drives the switch device 130 to close and the bidirectional semiconductor switch module 120 to enter the amplification state. The bidirectional semiconductor switch module 120 acts as a current limiter, allowing the power battery to discharge slowly to achieve pre-charging. When high-voltage power-up is required, the drive circuit assembly 110 drives the switch device 130 to close and the bidirectional semiconductor switch module 120 to conduct, connecting the power battery to the high-voltage system and achieving high-voltage power-up control. When high-voltage power-down is required, the drive circuit assembly 110 controls the output voltage to cut off the two-wire semiconductor switch module 120 and disconnect the switch device 130, disconnecting the power battery from the high-voltage system and achieving high-voltage power-down control.

[0038] Specifically, the driving circuit component 110 can drive the switching device 130 to close by outputting a voltage that turns on the switching device 130; and can control the switching device 130 to open by stopping the output voltage to the switching device 130 or outputting a low voltage that cannot turn on the switching device 130. The driving circuit component 110 can control the bidirectional semiconductor switch module 120 to be in an amplified state, turned on, or cut off by outputting different voltages to the control terminal of the bidirectional semiconductor switch module 120. For example Figure 2 As shown in the driving voltage variation curve, the ordinate represents the voltage at the control terminal. The interval S2 is a first voltage range. The voltage within the first voltage range is the voltage that enables the bidirectional semiconductor switch module 120 to operate in the amplification range and is determined by the switching characteristics of the bidirectional semiconductor switch module 120. When the voltage output to the control terminal of the bidirectional semiconductor switch module 120 is within the S2 range, the bidirectional semiconductor switch module 120 is in the amplification state and operates in the amplification range, achieving current limiting. When the voltage output to the control terminal of the bidirectional semiconductor switch module 120 is within the S3 range, the bidirectional semiconductor switch module 120 is turned on. When the voltage output to the control terminal of the bidirectional semiconductor switch module 120 is within the S1 range, the bidirectional semiconductor switch module 120 is in the off state.

[0039] The power battery high-voltage control unit uses a bidirectional semiconductor switch module 120 and a switch device 130 connected to the connection line between the power battery and the high-voltage system. The bidirectional semiconductor switch module 120 and the switch device 130 are driven by the drive circuit assembly 110 to control the operation of the bidirectional semiconductor switch module 120 and the switch device 130 to control the on and off of the bidirectional semiconductor switch module 120 and the switch device 130, thereby controlling the use of the power battery for pre-charging, connecting the high-voltage system to high-voltage power-up, or disconnecting the high-voltage system to high-voltage power-down. In this way, a semiconductor-type switch (bidirectional semiconductor switch module 120) replaces the traditional mechanical switch (high-voltage DC contactor) to achieve high-voltage power-up and power-down control, eliminating the pre-charging circuit composed of pre-charging resistors and pre-charging contactors in the existing method, saving costs. In addition, the bidirectional semiconductor switch module 120 is provided at one end of the connection between the power battery and the high-voltage system, and the switch device 130 is provided at the other end, which can improve the reliability of the high-voltage power-up and power-down control.

[0040] In one embodiment, reference Figure 3 The switch control device 130 includes a mechanical contactor. The control terminal of the mechanical contactor is connected to the drive circuit assembly 110. The first contact of the mechanical contactor is connected to the second electrode A2 of the power battery. The second terminal of the mechanical contactor is connected to the other terminal B2 of the high-voltage system. The mechanical contactor has no leakage current, which can avoid the safety risks caused by leakage current.

[0041] Specifically, during pre-charging, the driver circuit assembly 110 drives the mechanical contactor to close and outputs a voltage within the first voltage range to the control terminal of the bidirectional semiconductor switch module 120, causing the bidirectional semiconductor switch module 120 to operate in the amplification range. By driving the mechanical contactor closed and the bidirectional semiconductor switch module 120 in the amplification state, the power battery slowly discharges to charge the bypass pre-charge capacitor, thereby controlling pre-charging without requiring an additional pre-charging circuit.

[0042] During high-voltage power-up, the drive circuit assembly 110 drives the mechanical contactor to close and outputs a turn-on voltage greater than the first voltage range to the control terminal of the bidirectional semiconductor switch module 120, thereby turning on the bidirectional semiconductor switch module 120. This connects the power battery to the high-voltage system and controls high-voltage power-up.

[0043] During high-voltage power-down, the drive circuit assembly 110 outputs a cutoff voltage, less than the first voltage range, to the control terminal of the bidirectional semiconductor switch module 120, turning off the bidirectional semiconductor switch module 120. The drive circuit assembly 110 also controls the mechanical contactor to open. This disconnects the power battery from the high-voltage system, allowing the high-voltage power-down to be controlled.

[0044] Furthermore, the drive circuit component 110 can receive instructions and adjust the output voltage to the order of the mechanical contactor and the bidirectional semiconductor switch module 120 according to the instructions to control the order in which the mechanical contactor and the bidirectional semiconductor switch module 120 are closed. For example, during pre-charging, the mechanical contactor is first driven to close, and then the bidirectional semiconductor switch module 120 is driven to be in the amplification range. When the high voltage is powered on, the mechanical contactor is first driven to close, and then the bidirectional semiconductor switch module 120 is driven to be turned on. Since the bidirectional semiconductor switch module 120 is not turned on and there is no current in the circuit when the mechanical contactor is closed, there is no electric shock burning in the mechanical contactor. When the high voltage is disconnected, the bidirectional semiconductor switch module 120 is disconnected first and then the mechanical contactor. At this time, there is no current in the circuit and no electric shock burning. In this way, no arc is generated when the mechanical contactor is closed, no arc burning occurs on the contacts, and the loss can be ignored, thereby realizing electric shock protection of the mechanical contactor, greatly improving the service life, and greatly improving the electrical safety of the power battery.

[0045] It is understood that in other embodiments, the switch device 130 may also include any one of a bidirectional IGBT, a bidirectional MOS switch, and a bidirectional transistor. Figure 4 As shown, the switching device 130 may also be a bidirectional IGBT.

[0046] In one embodiment, the driving circuit assembly 110 may be a battery management system with an integrated driving circuit. Specifically, the driving circuit assembly 110 includes: a processing chip, a first driving circuit, and a second driving circuit. For example, the bidirectional semiconductor switch module 120 includes a bidirectional IGBT. Figure 3 As shown, the processing chip is burned with a battery management software program (BMSSoftware), the first drive circuit is an IGBT drive for driving a bidirectional IGBT, and the second drive circuit is a contactor drive for driving a mechanical contactor.

[0047] The processing chip is a device for realizing the battery management function; wherein, one end of the first driving circuit is connected to the processing chip, and the other end is connected to the control end of the bidirectional semiconductor switch module 120, and is used to drive the operation of the bidirectional semiconductor switch module; one end of the second driving circuit is connected to the processing chip, and the other end is connected to the control end of the switching device 130, and is used to drive the operation of the switching device 130.

[0048] Specifically, during pre-charging, the second drive circuit drives the switch device 130 to close, and the first drive circuit outputs a voltage within the first voltage range to the control terminal of the bidirectional semiconductor switch module 120, causing the bidirectional semiconductor switch module 120 to operate in the amplification range. During high-voltage power-up, the second drive circuit drives the switch device 130 to close, and the first drive circuit outputs a turn-on voltage greater than the first voltage range to the control terminal of the bidirectional semiconductor switch module 120, causing the bidirectional semiconductor switch module 120 to conduct. During high-voltage power-down, the first drive circuit outputs a cut-off voltage less than the first voltage range to the control terminal of the bidirectional semiconductor switch module 120, causing the bidirectional semiconductor switch module 120 to turn off, and the second drive circuit controls the switch device 130 to open.

[0049] In one embodiment, the drive circuit assembly 110 can be designed with an overcurrent protection function. Specifically, the drive circuit assembly 110 includes a current detection circuit, one end of which is connected to the connection line between the power battery and the high-voltage system, and the other end is connected to the processing chip. The connection line includes the line between the power battery and the bidirectional semiconductor switch module 120, the line between the bidirectional semiconductor switch module 120 and the high-voltage system, the line between the power battery and the switch device 130, and the line between the switch device 130 and the high-voltage system.

[0050] When the current detected by the current detection circuit exceeds a threshold, the processing chip outputs a cutoff instruction to the first drive circuit, causing the first drive circuit to output a cutoff voltage to the control terminal of the bidirectional semiconductor switch module 120, thereby turning off the bidirectional semiconductor switch module 120. Specifically, the current detection circuit can use any circuit that can implement a current detection function, and the processing chip can use an existing chip with a comparison processing module or comparator structure to implement overcurrent protection and improve the safety of the power battery. For example, when a BMS (battery management system) with overcurrent protection detects that the system current exceeds a threshold (e.g., 500A), it controls the bidirectional semiconductor switch module 120 to be turned off.

[0051] In one embodiment, the bidirectional semiconductor switch module 120 includes any one of a bidirectional IGBT, a bidirectional MOS switch, and a bidirectional transistor, and can implement bidirectional switch control.

[0052] For example, refer to Figure 3 The bidirectional semiconductor switch module 120 includes a bidirectional IGBT. The bidirectional IGBT is a voltage-controlled device with almost no gate power consumption and negligible leakage current during operation, which can reduce the vehicle's low-voltage power consumption and increase the vehicle's range.

[0053] In one embodiment, the bidirectional semiconductor switch module 120 also includes an overcurrent protection circuit. The first end of the bidirectional IGBT / bidirectional MOS switch / bidirectional triode is connected to the power battery through the overcurrent protection circuit, and / or the second end of the bidirectional IGBT / bidirectional MOS switch / bidirectional triode is connected to the high-voltage system through the overcurrent protection circuit. The overcurrent protection circuit can utilize an existing circuit structure that can implement overcurrent protection. By using a bidirectional semiconductor switch module 120 with built-in overcurrent protection, additional high-voltage fuses are not required, thereby reducing costs.

[0054] For example, the bidirectional semiconductor switch module 120 may utilize a bidirectional IGBT chip with built-in overcurrent protection. When the bidirectional IGBT chip detects that the current exceeds an upper limit (e.g., 1000A), its own protection is activated, and the switch stops conducting without requiring the driver circuit assembly 110 to operate, thereby disconnecting the high-voltage system.

[0055] In one embodiment, the power battery high-voltage control unit further includes a first protection circuit; one end of the first protection circuit is connected to the control terminal of the bidirectional semiconductor switch module 120, and the other end is connected to the second terminal A2 of the bidirectional semiconductor switch module 120, that is, the terminal of the bidirectional semiconductor switch module 120 that is connected to the high-voltage system. The provision of the first protection circuit protects the circuit, prevents component damage, reduces high-voltage hazards, and improves vehicle safety.

[0056] In one embodiment, the power battery high-voltage control unit further includes a second protection circuit; one end of the second protection circuit is connected to the drive circuit assembly 110, and the other end is connected to the control terminal of the bidirectional semiconductor switch module 120. That is, the drive circuit assembly 110 is connected to the control terminal of the bidirectional semiconductor switch module 120 through the second protection circuit. The second protection circuit can provide current limiting protection to prevent damage to the device caused by high voltage and high current.

[0057] In one embodiment, the power battery high-voltage control unit also includes a third protection circuit; one end of the third protection circuit is connected to the control terminal of the bidirectional semiconductor switch module 120, and the other end is connected to the first terminal A1 of the bidirectional semiconductor switch module 120, that is, the terminal of the bidirectional semiconductor switch module 120 connected to the power battery. The provision of this third protection circuit further protects the circuit and improves vehicle safety.

[0058] It can be understood that the first protection circuit, the second protection circuit and the third protection circuit can adopt existing protection circuit structures, and this application does not impose any restrictions on this.

[0059] In addition, the present application provides a power battery system, including a power battery and the power battery high-voltage control unit in the aforementioned embodiments, wherein the power battery is connected to the power battery high-voltage control unit.

[0060] The various technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification as long as such combination does not conflict.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A power battery high voltage control unit, characterized in that: Including bidirectional semiconductor switch module, switch device and drive circuit assembly; A first end of the bidirectional semiconductor switch module is connected to a first electrode of the power battery, a second end of the bidirectional semiconductor switch module is connected to one end of the high-voltage system, and a control end of the bidirectional semiconductor switch module is connected to the drive circuit assembly; The first end of the switch device is connected to the second electrode of the power battery, the second end of the switch device is connected to the other end of the high-voltage system, and the control end of the switch device is connected to the drive circuit assembly.

2. The power battery high-voltage control unit according to claim 1, characterized in that: The switching device includes a mechanical contactor; During pre-charging, the driving circuit assembly drives the mechanical contactor to close and causes the bidirectional semiconductor switch module to operate in the amplification range; When the high voltage is powered on, the drive circuit assembly drives the mechanical contactor to close and turns on the bidirectional semiconductor switch module; When the high voltage is turned off, the driving circuit component turns off the bidirectional semiconductor switch module and controls the mechanical contactor to open.

3. The power battery high-voltage control unit according to claim 1 or 2, characterized in that: The driving circuit assembly includes: a processing chip, a first driving circuit and a second driving circuit; One end of the first driving circuit is connected to the processing chip, and the other end is connected to the control end of the bidirectional semiconductor switch module; One end of the second driving circuit is connected to the processing chip, and the other end is connected to the control end of the switching device.

4. The power battery high-voltage control unit according to claim 3, characterized in that: The drive circuit assembly further includes a current detection circuit, one end of which is connected to the connection line between the power battery and the high-voltage system, and the other end of which is connected to the processing chip; When the current detected by the current detection circuit is greater than a threshold, the processing chip outputs a cutoff instruction to the first drive circuit, causing the first drive circuit to output a cutoff voltage to the control end of the bidirectional semiconductor switch module.

5. The power battery high voltage control unit according to claim 1, characterized in that: The bidirectional semiconductor switch module includes any one of a bidirectional IGBT, a bidirectional MOS switch, and a bidirectional triode.

6. The power battery high-voltage control unit according to claim 5, characterized in that: The bidirectional semiconductor switch module also includes an overcurrent protection circuit, and the first end of the bidirectional IGBT / the bidirectional MOS switch / the bidirectional triode is connected to the power battery through the overcurrent protection circuit, and / or the second end of the bidirectional IGBT / the bidirectional MOS switch / the bidirectional triode is connected to the high-voltage system through the overcurrent protection circuit.

7. The power battery high-voltage control unit according to claim 1, characterized in that: Also includes a first protection circuit and / or a second protection circuit; One end of the first protection circuit is connected to the control end of the bidirectional semiconductor switch module, and the other end is connected to the second end of the bidirectional semiconductor switch module; One end of the second protection circuit is connected to the driving circuit component, and the other end is connected to the control end of the bidirectional semiconductor switch module.

8. The power battery high-voltage control unit according to claim 7, characterized in that: Also including a third protection circuit; One end of the third protection circuit is connected to the control end of the bidirectional semiconductor switch module, and the other end is connected to the first end of the bidirectional semiconductor switch module.

9. The power battery high-voltage control unit according to claim 1, characterized in that: The switching device includes any one of a two-wire IGBT, a bidirectional MOS switch and a bidirectional triode.

10. A power battery system, characterized in that: The invention comprises a power battery and a power battery high-voltage control unit according to any one of claims 1 to 9, wherein the power battery is connected to the power battery high-voltage control unit.

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