Overvoltage protection circuit and motor controller

Abstract

The invention discloses an overvoltage protection circuit and a motor controller. The circuit comprises an overvoltage protection module which is connected with a high-voltage bus and is used for detecting the bus voltage of the high-voltage bus and outputting a first overvoltage protection signal under the condition that the bus voltage meets an overvoltage condition; the low-side driving module is connected with the overvoltage protection module and a corresponding target power switch, and is used for outputting an active short-circuit control signal to the target power switch under the condition that the first overvoltage protection signal is received; and the backup power supply module is connected with the high-voltage bus, the overvoltage protection module and the low-side driving module, and is used for supplying power to the overvoltage protection module and the low-side driving module based on the bus voltage of the high-voltage bus under the condition that the low-voltage side power supply is abnormal. According to the embodiment of the invention, the function safety of the motor controller can be realized at low cost.

Description

Technical Field

[0001] The present application belongs to the field of new energy vehicle technology, and in particular relates to an overvoltage protection circuit and a motor controller. Background Art

[0002] With economic development and advancements in smart car technology, smart cars are becoming increasingly common, and electronic control systems are becoming the core of precise vehicle control. However, failure of electronic control systems can lead to serious safety accidents. Therefore, the industry has established stricter functional safety requirements for key components such as electric drive controllers.

[0003] The core of functional safety requirements is that when an electronic control system fails, the power devices corresponding to the electric drive controller can be put into a safe state through the safe state control path, thereby avoiding harm to the driver or passengers.

[0004] However, achieving functional safety requirements often requires redundant designs for multiple circuits, which increases vehicle costs. Therefore, reducing the cost of achieving functional safety requirements in vehicles is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The embodiments of the present application provide an overvoltage protection circuit and a motor controller, which can achieve functional safety of the motor controller at a low cost.

[0006] In the first aspect, an embodiment of the present application provides an overvoltage protection circuit, which is applied to a motor controller, including: an overvoltage protection module, connected to a high-voltage bus, for detecting the bus voltage of the high-voltage bus and outputting a first overvoltage protection signal when the bus voltage meets the overvoltage condition; a low-side drive module, the low-side drive module is connected to the overvoltage protection module and the corresponding power switch, for outputting an active short-circuit control signal to the power switch when the first overvoltage protection signal is received; a backup power supply module, connected to the high-voltage bus, the overvoltage protection module and the low-side drive module, for supplying power to the overvoltage protection module and the low-side drive module based on the bus voltage of the high-voltage bus when an abnormality occurs in the low-voltage side power supply.

[0007] In one embodiment, the overvoltage protection module includes: an overvoltage protection unit, connected to the high-voltage bus, and used to output a first control signal when the bus voltage meets the overvoltage condition; a first switch unit, the control end of the first switch unit is connected to the overvoltage protection unit, the first end of the first switch module is connected to the overvoltage protection signal end, and the second end of the first switch module is connected to the low-side drive module, and is used to switch to the on state after receiving the first control signal.

[0008] In one embodiment, the overvoltage protection module is also used to output a second overvoltage protection signal when the bus voltage meets the overvoltage condition; the circuit also includes: a hardware fault control module, which is connected to the overvoltage protection module, the low-side driver module, and the high-side driver module, and is used to output a first latch signal to the low-side driver module and a second latch signal to the high-side driver module when the second overvoltage protection signal is received.

[0009] In one embodiment, the circuit further includes a signal isolation module, which is connected between the overvoltage protection module and the hardware fault control module and is used to adjust the second overvoltage protection signal to within the input voltage range of the hardware fault control module.

[0010] In one embodiment, the second overvoltage protection signal is a first control signal output by the overvoltage protection unit.

[0011] In one embodiment, the first overvoltage protection signal and the second overvoltage protection signal are latched signals; the circuit also includes: a controller, configured to output a reset signal when it is determined that the bus voltage meets the safety voltage condition; a safe state reset module, connected to the controller and the overvoltage protection module, configured to output a reset control signal to the overvoltage protection module when the reset signal is received; the overvoltage protection module is configured to unlock and reset the first overvoltage protection signal and the second overvoltage protection signal when the reset control signal is received.

[0012] In one embodiment, the circuit further includes: a signal acquisition module, which is connected between the controller and the high-voltage bus, and is used to convert the collected bus voltage and send the converted voltage to the controller.

[0013] In one embodiment, the signal acquisition module includes: a signal acquisition unit connected to the high-voltage bus and used to acquire the bus voltage; a voltage regulation unit connected to the controller and the signal acquisition unit and used to adjust the bus voltage to within the input voltage range of the controller.

[0014] In one embodiment, the circuit further includes a signal isolation module connected between the controller and the safe state reset module, and configured to adjust the reset signal to be within an input voltage range of the safe state reset module.

[0015] In one embodiment, the controller is connected to the low-side driver module and the high-side driver module, and is used to send a low-side driver signal to the low-side driver module, and send a high-side driver signal to the high-side driver module, and send an alarm message in response to the fault signal fed back by the low-side driver module and the high-side driver module.

[0016] In one embodiment, the backup power supply module includes: a voltage conversion unit connected to the high-voltage bus, used to convert the bus voltage into a backup power supply voltage; a unidirectional conduction unit, the first end of the unidirectional conduction unit is connected to the voltage conversion unit, and the second end of the unidirectional conduction unit is connected to the low-side drive module.

[0017] In a second aspect, an embodiment of the present application provides a motor controller, comprising the overvoltage protection circuit of the first aspect or any one embodiment of the first aspect and a three-phase bridge circuit.

[0018] The overvoltage protection circuit and motor controller of the embodiment of the present application can, in the event of an abnormality in the low-voltage side power supply, be powered by the backup power supply module for the overvoltage protection module and the low-side driver module, so that they perform high-voltage safety protection functions. Wherein, after being powered by the backup power supply module, the overvoltage protection module can send a first overvoltage protection signal to the low-side driver module when it detects that the bus voltage in the high-voltage bus meets the overvoltage condition, so that the low-side driver module can output an active short-circuit control signal to the corresponding target power switch according to the first overvoltage protection signal to achieve active short circuit. This can ensure that in the event of an abnormality in the low-voltage side power supply, the motor controller can trigger the corresponding safety mechanism to ensure the safety of the power device, thereby ensuring the safety of the vehicle and passengers. It is understandable that since the backup power supply module can convert the bus voltage into a voltage that meets the voltage safety range of the overvoltage protection module and the low-side driver module, and power the overvoltage protection module and the low-side driver module, this can avoid the need for an additional backup power supply to power the overvoltage protection module and the low-side driver module, thereby reducing vehicle costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of the architecture of a partial overvoltage protection circuit of a motor controller provided by one embodiment of the present application is shown;

[0021] Figure 2 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0022] Figure 3 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0023] Figure 4 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0024] Figure 5 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0025] Figure 6 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0026] Figure 7 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0027] Figure 8 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0028] Figure 9 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0029] Figure 10 A schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application is shown;

[0030] Figure 11 A schematic diagram of the architecture of a motor controller provided in one embodiment of the present application is shown.

[0031] Description of reference numerals:

[0032] 100. Partial overvoltage protection circuit; 200. Overvoltage protection circuit; 11. High-side driver module; 12. Low-side driver module; 131. First power switch; 132. Target power switch; 14. Signal isolation module; 15. Overvoltage protection module; 16. Backup power module; 17. Overvoltage protection unit; 18. First switch unit; 19. Hardware fault control module; 20. Controller; 21. Safety state reset module; 22. Signal acquisition module; 23. Signal acquisition unit; 24. Voltage regulation unit; 25. Voltage conversion unit; 26. One-way conduction unit; D1. Diode; Q1. Transistor; 1001. First sampling unit; 1002. Second sampling unit; 1100. Motor controller; 1101. Three-phase bridge circuit. DETAILED DESCRIPTION

[0033] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0034] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0035] With economic development and advancements in smart car technology, smart cars are becoming increasingly popular, and electronic control systems are becoming the core hub for precise vehicle control. However, failure of electronic control systems can lead to serious safety accidents. As a key component in driving a vehicle's power devices, electric drive controllers are subject to stringent functional safety requirements. The core of these functional safety requirements is the ability to ensure that, in the event of a single or multiple point failure in the electronic control system, the power devices controlled by the motor controller enter a safe state through a safe state control path, thereby preventing harm to the driver or passengers.

[0036] It is understandable that if the power supply of the motor controller fails, since the motor controller is connected to both ends of the DC bus capacitor, the voltage will be overvoltage due to the impact of the back electromotive force of the permanent magnet synchronous motor, which may cause the motor to burn out or even cause harm to the driver or passengers.

[0037] In view of this, in the electronic control system, when a single point or even multiple points of failure occur, the vehicle's safety mechanism can be triggered, so that the power devices controlled by the motor controller enter a safe state. Figure 1 FIG. 1 shows a schematic diagram of the structure of a partial overvoltage protection circuit 100 of a motor controller provided by an embodiment of the present application. Figure 1As shown, a partial overvoltage protection circuit can include three high-side driver chips, namely, high-side driver modules 11, which can respectively control the first power switches 131 corresponding to the three upper bridges of the power device, and three low-side driver chips, namely, low-side driver modules 12, which can respectively control the target power switches 132 corresponding to the three lower bridges of the power device. Furthermore, after a power failure, when an overvoltage signal is detected, the overvoltage signal can be processed accordingly using the signal isolation module 14, for example, by reducing the voltage, thereby reducing the voltage of the overvoltage signal to a safe voltage range that can be supported by the low-side driver chips. In this case, the three low-side driver chips can be powered by a low-voltage backup power supply or a high-voltage backup power supply, and the low-voltage backup power supply and the high-voltage backup power supply can be independent power supplies. Furthermore, the reduced-voltage overvoltage signal is fed back to the low-side driver chip, thereby triggering a safety mechanism, for example, by controlling the target power switch 132 to short-circuit the three-phase winding, thereby preventing the power device from burning and causing safety issues.

[0038] Achieving functional safety requirements often requires the coordinated operation of multiple backup power supplies, which increases vehicle costs. Therefore, reducing the cost of achieving functional safety requirements in vehicles is a pressing technical challenge for those skilled in the art. To address these existing technical issues, embodiments of the present application provide an overvoltage protection circuit and a motor controller. The following describes the overvoltage protection circuit provided in embodiments of the present application.

[0039] Figure 2 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 2 As shown, the overvoltage protection circuit 200 includes: an overvoltage protection module 15, which is connected to the high-voltage bus and is used to detect the bus voltage of the high-voltage bus and output a first overvoltage protection signal when the bus voltage meets the overvoltage condition; a low-side driver module 12, which is connected to the overvoltage protection module 15 and the corresponding target power switch 132, and is used to output an active short-circuit control signal to the target power switch 132 when the first overvoltage protection signal is received; a backup power supply module 16, which is connected to the high-voltage bus, the overvoltage protection module 15 and the low-side driver module 12, and is used to power the overvoltage protection module 15 and the low-side driver module 12 based on the bus voltage of the high-voltage bus when an abnormality occurs in the low-voltage side power supply.

[0040] For example, the overvoltage protection module 15 is connected to the high-voltage bus to obtain the bus voltage of the high-voltage bus. Furthermore, the overvoltage protection module 15 can be configured to determine whether the obtained bus voltage satisfies an overvoltage condition. If the bus voltage satisfies the overvoltage condition, the module outputs a first overvoltage protection signal.

[0041] An overvoltage condition can be used to characterize bus voltage variations in a bus. In one example, the overvoltage condition can include the bus voltage being greater than a first preset voltage threshold. In another example, the overvoltage condition can include the bus voltage varying between adjacent sampling points being greater than a first preset variation threshold.

[0042] For example, the low-side driver module 12 is connected to the overvoltage protection module 15 and the corresponding target power switch 132. After receiving the first overvoltage protection signal output by the overvoltage protection module 15, the low-side driver module 12 can output an active short circuit control signal to the target power switch 132. The target power switch 132 can adjust the switching state based on the active short circuit control signal to enable the power device to implement active short circuit (ASC).

[0043] It is understood that the power device can be driven by a three-phase bridge circuit, wherein the three-phase bridge circuit may include three lower bridge arms and three upper bridge arms. The power device can be controlled by controlling the power switches corresponding to the upper and lower bridge arms in the three-phase bridge circuit. Therefore, the low-side driver module 12 can be a three-channel driver module, where each channel can be used to control the target power switch 132 corresponding to each lower bridge arm of the power device.

[0044] Furthermore, in some optional embodiments, the low-side driver module 12 may also include three single-channel low-side driver chips, and the three low-side driver chips may be respectively connected to the target power switch 132 corresponding to each lower bridge arm. In addition, each low-side driver chip is connected to the overvoltage protection module 15 to receive the first overvoltage protection signal output by the overvoltage protection module 15. After each low-side driver chip receives the first overvoltage protection signal, it may output an active short-circuit control signal to the corresponding target power switch 132. Based on receiving the active short-circuit control signal, the target power switch 132 adjusts the state of the target power switch 132 to achieve active short-circuiting of the power device, thereby preventing damage to the power device.

[0045] Exemplarily, the backup power supply module 16 is connected to the high-voltage bus, the overvoltage protection module 15, and the low-side driver module 12, respectively, and is used to supply power to the overvoltage protection module 15 and the low-side driver module 12 when an abnormality occurs in the low-voltage side power supply. The backup power supply module 16 can convert the voltage in the high-voltage bus into a voltage that can be received by the overvoltage protection module 15 and the low-side driver module 12.

[0046] The backup power module 16 can be used to convert the bus voltage so that the bus voltage can be converted to a voltage that meets the voltage safety range of the overvoltage protection module 15 and the low-side driver module 12, thereby powering the overvoltage protection module 15 and the low-side driver module 12. In one example, the backup power module can step down the bus voltage and use the stepped-down bus voltage to power the overvoltage protection module 15 and the low-side driver module 12, that is, the backup power module can play a voltage-reducing role.

[0047] In an embodiment of the present application, in the event of an abnormality in the low-voltage side power supply, the backup power supply module 16 can be used to power the overvoltage protection module 15 and the low-side driver module 12, so that they perform high-voltage safety protection functions. After being powered by the backup power supply module 16, the overvoltage protection module 15 can send a first overvoltage protection signal to the low-side driver module 12 when it detects that the bus voltage in the high-voltage bus meets the overvoltage condition, so that the low-side driver module 12 can output an active short-circuit control signal to the corresponding target power switch 132 according to the first overvoltage protection signal to achieve active short-circuiting. This ensures that in the event of an abnormality in the low-voltage side power supply, the motor controller can trigger the corresponding safety mechanism to ensure the safety of the power device, thereby ensuring the safety of the vehicle and passengers. It is understandable that since the backup power supply module 16 can convert the bus voltage into a voltage that meets the voltage safety range of the overvoltage protection module 15 and the low-side driver module 12, and supply power to the overvoltage protection module 15 and the low-side driver module 12, this can avoid the need for an additional backup power supply to power the overvoltage protection module 15 and the low-side driver module 12, thereby reducing vehicle costs.

[0048] Furthermore, in order to improve the reliability of the overvoltage circuit, as another implementation of the present application, the present application also provides another implementation of the overvoltage protection circuit 200, which is described in detail in the following embodiments.

[0049] Figure 3 FIG. 1 shows a schematic diagram of an overvoltage protection circuit according to an embodiment of the present application. Figure 3 As shown, the overvoltage protection module 15 includes: an overvoltage protection unit 17, which is connected to the high-voltage bus and is used to output a first control signal when the bus voltage meets the overvoltage condition; a first switch unit 18, the control end of the first switch unit 18 is connected to the overvoltage protection unit 17, the first end of the first switch module is connected to the overvoltage protection signal end, and the second end of the first switch module is connected to the low-side driver module 12, and is used to switch to the on state after receiving the first control signal.

[0050] Exemplarily, the overvoltage protection unit 17 is capable of detecting the bus voltage and outputting a first control signal when the bus voltage meets an overvoltage condition.

[0051] Exemplarily, the first switch unit 18 is connected to the overvoltage protection unit 17 , can receive a first control signal output by the overvoltage protection unit 17 , and switch the first switch unit 18 from an off state to an on state according to the first control signal.

[0052] When the first switch unit 18 is switched to the on state, the overvoltage protection signal terminal can output a first overvoltage protection signal to the low-side driver module 12. After receiving the first overvoltage protection signal, the low-side driver module 12 can output an active short-circuit control signal to the target power switch 132 of the power device to achieve active short circuit of the power device.

[0053] In one example, the overvoltage protection signal terminal can be a power supply terminal included in the low-side driver module 12, and the first overvoltage protection signal can be a high-level signal output by the power supply terminal. That is, the control terminal of the first switch unit 18 can be connected to the overvoltage protection unit 17, the first terminal of the first switch unit 18 can be connected to the power supply terminal included in the low-side driver module 12, and the second terminal of the first switch unit 18 can be connected to the low-side driver module 12. When the first switch unit 18 receives the first control signal sent by the overvoltage protection unit 17, the first switch unit 18 changes from an off state to an on state, thereby inputting the signal at the power supply terminal, i.e., the first overvoltage protection signal, into the low-side driver module 12. Upon receiving the first overvoltage protection signal, the low-side driver module 12 outputs an active short-circuit control signal to the target power switch 132.

[0054] The first switch unit 18 can be a passive switching device. In one example, the first switch unit 18 can be a transistor, for example, a metal-oxide-semiconductor field-effect transistor (MOS), or a triode. In another example, the first switch unit 18 can be an optocoupler.

[0055] It is understood that the first switch unit 18, as a triggering device for the low-side driver module 12 to output an active short-circuit control signal to the target power switch 132, can reduce the risk of trigger failure due to its passive nature, thereby improving the reliability of the low-side driver module 12. Furthermore, because the first switch unit 18 serves as a triggering device for adjusting the states of multiple power switches corresponding to power devices, it can achieve simultaneous adjustment of the states of multiple target power switches 132, ensuring that the multiple target power switches 132 can simultaneously execute the active short-circuit control signal, achieving precise synchronization, and thus avoiding damage to the power devices.

[0056] In order to provide stable and reliable trigger conditions for the low-side driver module, as another implementation method of the present application, the present application also provides another implementation method of the overvoltage protection circuit, please refer to the following embodiments for details.

[0057] Figure 4 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 4 As shown, the overvoltage protection circuit 200 also includes: a hardware fault control module 19, which is connected to the overvoltage protection module 15, the low-side driver module 12, and the high-side driver module 11, and is used to output a first latch signal to the low-side driver module 12 and a second latch signal to the high-side driver module 11 when receiving a second overvoltage protection signal.

[0058] For example, the second overvoltage protection signal may be a signal output by the overvoltage protection module 15 when it is determined that the bus voltage meets the overvoltage condition.

[0059] In some optional embodiments, the second overvoltage protection signal may be the first control signal output by the overvoltage protection unit 17. It is understood that, when the overvoltage protection unit 17 determines that the bus voltage meets the overvoltage condition, it may simultaneously send a first control signal to the low-side driver module 12 for triggering the low-side driver module 12 to send an active short-circuit control signal. The first control signal may also be output to the hardware fault control module 19 so that the hardware fault control module 19 solidifies the power device state. This avoids triggering failure of the low-side driver module 12 due to instantaneous voltage drop, and provides a stable and reliable triggering condition for the low-side driver module 12.

[0060] The first latch signal enables the low-side driver module 12 to latch the state of the target power switch 132 corresponding to the lower three bridges of the power device, and the second latch signal enables the high-side driver module 11 to latch the state of the first power switch 131 corresponding to the upper three bridges of the power device.

[0061] In one example, the first latch signal and the second latch signal can be a safety pulse off (SPO) signal. It is understandable that the high-side driver module 11 and the low-side driver module 12 can regulate the target power switch 132 according to the pulse modulation signal (PWM) sent by the controller 20, such as the MCU, to achieve control of the power device. When the high-side driver module 11 and the low-side driver module 12 receive the first latch signal and the second latch signal, the high-side driver module 11 and the low-side driver module 12 do not respond to the PWM signal sent by the MCU, thereby achieving state latching of the power device. Moreover, at this time, the bottom-side driver module can output an active short-circuit control signal to control the corresponding power switch, thereby achieving active short circuit of the power device and avoiding damage to the power device.

[0062] In an embodiment of the present application, the overvoltage protection module 15 can output a second overvoltage protection signal to the hardware fault control module 19 when it is determined that the bus voltage meets the overvoltage condition. After receiving the second overvoltage protection signal, the hardware fault control module 19 can output a first latch signal to the low-side driver module 12 and a second latch signal to the high-side driver module 11, so as to solidify the states of all target power switches 132 corresponding to the power devices, thereby avoiding the failure of the low-side driver module 12 to trigger the safety mechanism due to voltage drop, and providing a stable and reliable triggering condition for the low-side driver module 12. In addition, the hardware fault control module 19 can simultaneously realize the state latching of the first power switch 131 corresponding to the high-side driver module 11 and the state latching of the target power switch 132 corresponding to the low-side driver module 12, so as to achieve the synchronization of the power device state latching, avoid the influence of the additional devices and the transmission loop in the execution path, and improve the synchronization of the latched state.

[0063] Furthermore, in order to improve the reliability and stability of the system, as another implementation of the present application, the present application also provides another implementation of the overvoltage protection circuit 200, which is described in detail in the following embodiments.

[0064] Figure 5 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 5 As shown, the overvoltage protection circuit 200 also includes: a signal isolation module 14, which is connected between the overvoltage protection module 15 and the hardware fault control module 19, and is used to adjust the second overvoltage protection signal to within the input voltage range of the hardware fault control module.

[0065] For example, the signal isolation module 14 can provide electrical isolation and voltage regulation. For example, the signal isolation module 14 can reduce the voltage of the second overvoltage protection signal so that the voltage value of the reduced-voltage second overvoltage protection signal meets the safety voltage range specified by the hardware fault control module 19.

[0066] In one example, the signal isolation module 14 may be an optical coupler or a magnetic coupler.

[0067] In this embodiment of the present application, a signal isolation module 14 can be added between the overvoltage protection module 15 and the hardware fault control module 19 to isolate the different circuit modules, preventing the high voltage or high current corresponding to the second overvoltage protection signal from affecting the hardware fault control module 19, thereby improving the reliability and stability of the overvoltage protection circuit. Furthermore, using only one signal isolation module can reduce vehicle costs.

[0068] In some optional embodiments, the first overvoltage protection signal and the second overvoltage protection signal can be latched signals. That is, after the overvoltage protection module 15 outputs the first overvoltage protection signal and the second overvoltage protection signal, the signal does not change with the bus voltage subsequently detected by the overvoltage protection module 15. For example, when the overvoltage protection module 15 determines that the bus voltage meets the overvoltage condition at the first moment, the overvoltage protection module can output the first overvoltage protection signal and the second overvoltage protection signal. Furthermore, when the overvoltage protection module 15 detects that the bus voltage does not meet the overvoltage condition at the next moment, the signal output by the overvoltage protection module 15 maintains the original value, that is, the overvoltage protection module still outputs the first overvoltage protection signal and the second overvoltage protection signal.

[0069] Furthermore, in order to improve the stability of the overvoltage protection circuit, as another implementation of the present application, the present application also provides another implementation of the overvoltage protection circuit 200, which is described in detail in the following embodiments.

[0070] Figure 6 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 6 As shown, the overvoltage protection circuit 200 also includes: a controller 20, which is used to output a reset signal when it is determined that the bus voltage meets the safety voltage condition; a safe state reset module 21, which is connected to the controller 20 and the overvoltage protection module 15, and is used to output a reset control signal to the overvoltage protection module 15 when the reset signal is received; the overvoltage protection module 15 is used to unlock and reset the first overvoltage protection signal and the second overvoltage protection signal when the reset control signal is received.

[0071] For example, the controller 20 can determine whether the bus voltage meets the safety voltage condition and output a reset signal if it determines that the bus voltage meets the safety voltage condition. After receiving the reset signal output by the controller 20, the safety state reset module 21 can output a reset control signal to the overvoltage protection module 15. The overvoltage protection module 15 can unlock and reset the first overvoltage protection signal and the second overvoltage protection signal based on the reset control signal.

[0072] For example, the safety voltage condition may be that the bus voltage is less than or equal to a second preset voltage threshold. The second preset voltage threshold may be less than or equal to the first preset voltage threshold. Alternatively, the safety voltage condition may be that the bus voltage change between adjacent sampling points is less than or equal to a second preset change threshold. The second preset change threshold is less than or equal to the first preset change threshold.

[0073] In one example, after receiving the reset control signal, the overvoltage protection module 15 can stop outputting the first overvoltage protection signal to the low-side driver module 12, thereby restoring the state of the target power switch 132, that is, releasing the active short-circuit state of the target power switch 132. Furthermore, after receiving the reset control signal, the overvoltage protection module 15 can also stop sending the second overvoltage protection signal to the hardware fault control module 19, thereby enabling the low-side driver module 12 and the high-side driver module 11 to control the power switch according to the PWM signal sent by the controller 20.

[0074] In some optional embodiments, Figure 7 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 7 As shown, the overvoltage protection circuit 200 also includes: a signal acquisition module 22, which is connected between the controller 20 and the high-voltage bus, and is used to convert the collected bus voltage and send the converted voltage to the controller 20.

[0075] Exemplarily, the signal acquisition module 22 can be used to collect the bus voltage in the high-voltage bus, convert the bus voltage, and send the converted bus voltage to the controller 20 so that the controller 20 determines whether the bus voltage meets the overvoltage condition.

[0076] Among them, the signal acquisition module 22 may include a signal acquisition unit 23, which is connected to the high-voltage bus and is used to collect the bus voltage; a voltage regulation unit 24, which is connected to the controller 20 and the signal acquisition unit 23 and is used to adjust the bus voltage to within the input voltage range of the controller.

[0077] For example, the signal acquisition unit 23 may be used to acquire the bus voltage. In one example, the bus voltage may be acquired by a voltage sensor or the like.

[0078] Exemplarily, the voltage regulator unit 24 can be used for signal conditioning and digital-to-analog conversion. In one example, the voltage regulator unit 24 can include a step-down circuit to adjust the bus voltage to a safe voltage range corresponding to the controller 20. Furthermore, the voltage regulator unit 24 can also include an analog-to-digital conversion circuit to convert analog signals collected by the sensor into digital signals that can be recognized by the controller 20.

[0079] In the embodiment of the present application, the bus voltage is collected by the acquisition unit, and the bus voltage is adjusted to a voltage signal recognizable by the controller 20 through the voltage regulation unit 24. A stable and accurate bus voltage signal is provided to the controller 20, thereby providing good data support for the controller 20 to accurately determine whether the bus voltage meets the overvoltage condition.

[0080] In some optional embodiments, Figure 8 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 8 As shown, the overvoltage protection circuit 200 further includes: a signal isolation module 14, which is connected between the controller 20 and the safe state reset module 21 and is used to adjust the reset signal to within the input voltage range of the safe state reset module.

[0081] Exemplarily, the signal isolation module 14 is connected between the controller 20 and the safety state reset module 21, and can adjust the reset signal to the safety voltage range corresponding to the safety state reset module 21, thereby improving the response effect of the safety state reset module 21 to the reset signal.

[0082] For example, the signal isolation module 14 can also perform analog-to-digital conversion, that is, it can convert the reset signal into a digital signal, thereby improving the signal recognition effect of the safety state reset module.

[0083] In other optional embodiments, the controller 20 can be connected to the low-side driver module 12 and the high-side driver module 11 to send a low-side driver signal to the low-side driver module 12 and a high-side driver signal to the high-side driver chip.

[0084] In one example, the high-side driving signal sent by the controller 20 to the high-side driving chip and the low-side driving signal sent to the low-side driving module 12 may be PWM signals.

[0085] It is understandable that the target power switches 132 corresponding to the upper three bridges and the lower three bridges of the power device can be controlled by the low-side driving signal and the high-side driving signal, thereby controlling the power device.

[0086] In addition, the controller 20 can also send alarm information in response to the fault signals fed back by the low-side driver module and the high-side driver module, thereby accurately determining the fault situation of the driver module and laying a good foundation for the intelligent system.

[0087] In the embodiment of the present application, the controller 20 outputs a reset signal upon determining that the bus voltage meets the safety voltage condition. Upon receiving the reset signal, the safety state reset module 21 outputs a reset control signal to the overvoltage protection module 15 to release the power device from the active short-circuit state, enabling normal operation and control. It will be appreciated that the embodiment of the present application includes reset control for the power device, thereby enabling rapid release of fault control of the power device after fault recovery, thereby improving system stability.

[0088] In order to ensure the function of the backup power supply module, as another implementation method of the present application, the present application also provides another implementation method of the overvoltage protection circuit, please refer to the following embodiments for details.

[0089] Figure 9 FIG. 1 shows a schematic diagram of the architecture of an overvoltage protection circuit provided by an embodiment of the present application. Figure 9 As shown, the backup power supply module 16 includes: a voltage conversion unit 25, connected to the high-voltage bus, for converting the bus voltage into a backup power supply voltage; a unidirectional conduction unit 26, the first end of the unidirectional conduction unit 26 is connected to the voltage conversion unit 25, and the second end of the unidirectional conduction unit 26 is connected to the low-side driver module 12.

[0090] Exemplarily, the voltage conversion unit 25 is configured to adjust the bus voltage to a safe voltage range corresponding to the low-side driver module 12 and the overvoltage protection module 15. In one example, the voltage conversion unit 25 may be a step-down circuit that can step down the bus voltage so that the stepped-down bus voltage can power the low-side driver module 12 and the overvoltage protection module 15.

[0091] Furthermore, adding a unidirectional conduction unit 26 between the voltage conversion unit 25 and electrical devices, such as the low-side driver module 12 and the overvoltage protection module 15 , can prevent reverse voltage from impacting the overvoltage protection circuit 200 , thereby protecting various components in the circuit.

[0092] In one example, the unidirectional conducting unit 26 may be a diode D1 , wherein an anode of the diode D1 is connected to the voltage conversion unit 25 , and a cathode of the diode D1 is connected to an electrical device.

[0093] In the embodiment of the present application, the voltage conversion unit 25 is used to adjust the bus voltage to a safe voltage range corresponding to the low-side driver module 12 and the overvoltage protection module 15. Furthermore, the unidirectional conduction unit 26 can avoid reverse voltage surge circuits, ensuring that the low-side driver module 12 and the overvoltage protection module 15 can obtain stable and appropriate voltages.

[0094] Further, combined with Figure 10 The overvoltage protection circuit 200 is described in the following examples.

[0095] Figure 10 FIG. 1 shows a schematic diagram of an overvoltage protection circuit according to an embodiment of the present application. Figure 10 As shown, the overvoltage protection circuit 200 includes an MCU, a high-side driver module 11, and a low-side driver module 12. The high-side driver module 11 and the low-side driver module 12 are used to control the power switches corresponding to the upper three bridges and the lower three bridges of the power device respectively.

[0096] The MCU can send PWM signals to the high-side driver module 11 and the low-side driver module 12 respectively, so that the high-side driver module 11 and the low-side driver module 12 realize control of the corresponding target power switch 132, and then realize control of the power device. In addition, the MCU can also receive fault signals sent by the high-side driver module 11 and the low-side driver module 12, and issue an alarm based on the corresponding fault signal. Among them, the voltage in the high-voltage bus can be sampled by the second sampling unit 1002, and the sampled bus voltage is sent to the high-side driver module 11, so that the high-side driver module 11 can realize detection of high-side drive faults.

[0097] Furthermore, when a single-point or multi-point fault causes a bus overvoltage, the voltage conversion unit 25 in the overvoltage protection circuit 200 can step down the bus voltage, and diode D1 can be used to ensure circuit safety, thereby using the stepped-down bus voltage to power the electrical components in the circuit. The electrical components include at least the low-side driver module 12, the overvoltage protection module 15, the hardware fault control module 19, and the signal isolation module 14.

[0098] After receiving power from the voltage conversion unit 25, the overvoltage protection unit 17 can send a second overvoltage protection signal, such as a high-level signal, to the hardware fault control module 19 via the signal isolation module 14. After receiving the signal, the hardware fault control module 19 can send a first state latch signal and a second state latch signal to the high-side driver module 11 and the low-side driver module 12, respectively, so that the high-side driver module 11 and the low-side driver module 12 no longer respond to the PWM signal sent by the MCU, thereby achieving state latching for the power device.

[0099] At the same time, the overvoltage protection unit 17 sends a first control signal to the transistor Q1, wherein an NPN MOS tube is used as an example for explanation. The gate of Q1 is connected to the overvoltage protection module 15, the source is connected to the power supply end of the low-side driver module 12, and the drain is connected to the active short-circuit control interface of the low-side driver module 12. When the overvoltage protection unit 17 determines that the bus voltage is overvoltage, it can output a high-level signal. After receiving the high-level signal, Q1 is turned on, and the active short-circuit control interface receives the electrical signal provided by the power supply end, thereby triggering the control of the target power switch 132 corresponding to the lower three bridges, causing the target power switch 132 to actively short-circuit.

[0100] It can be understood that in the embodiment of the present application, the NPN MOS tube is only used for exemplary illustration, and the first switch unit 18 can also be a PNP MOS tube or a triode, etc., and the principles are the same, which will not be repeated in the embodiment of the present application.

[0101] Furthermore, the overvoltage protection circuit 200 may also include a first sampling unit 1001 for sampling the voltage of the high-voltage bus to obtain the bus voltage. Furthermore, the bus voltage can be stepped down and analog-to-digital converted using an isolation amplifier circuit, allowing the MCU to obtain a recognizable bus voltage. When the MCU determines that the bus voltage meets the safety voltage condition, a reset signal can be sent to the safety state reset module 21 via the signal isolation module 14. After receiving the reset signal, the safety state reset module 21 can send a reset control signal to the overvoltage protection module 15. After receiving the reset control signal, the overvoltage protection module 15 can send a low-level signal to Q1 and the hardware fault control module 19, thereby releasing the target power switch 132 corresponding to the lower three bridges from the active short-circuit state and enabling the high-side driver module 11 and the low-side driver module 12 to respond to the PWM signal sent by the MCU.

[0102] In addition, in combination with the overvoltage protection circuit in the above embodiment, a motor controller is also provided in the embodiment of the present application. Figure 11 FIG. 1 shows a schematic diagram of the architecture of a motor controller provided by an embodiment of the present application, as shown in FIG. Figure 11 As shown, the motor controller 1100 includes any one of the overvoltage protection circuits 200 in the above embodiments and a three-phase bridge circuit 1101 .

[0103] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. An overvoltage protection circuit, characterized in that: Applications in motor controllers, including: an overvoltage protection module connected to the high-voltage bus, configured to detect a bus voltage of the high-voltage bus, and output a first overvoltage protection signal when the bus voltage meets an overvoltage condition; a low-side driver module, the low-side driver module being connected to the overvoltage protection module and the corresponding target power switch, and being configured to output an active short-circuit control signal to the target power switch upon receiving the first overvoltage protection signal; A backup power supply module is connected to the high-voltage bus, the overvoltage protection module and the low-side driver module, and is used to power the overvoltage protection module and the low-side driver module based on the bus voltage of the high-voltage bus when an abnormality occurs in the low-voltage side power supply.

2. The circuit according to claim 1, characterized in that The overvoltage protection module includes: an overvoltage protection unit, connected to the high-voltage bus, and configured to output a first control signal when the bus voltage meets an overvoltage condition; A first switch unit, wherein the control end of the first switch unit is connected to the overvoltage protection unit, the first end of the first switch module is connected to the overvoltage protection signal end, and the second end of the first switch module is connected to the low-side driver module, and is used to switch to the on state after receiving the first control signal.

3. The circuit according to claim 1, wherein: The overvoltage protection module is further configured to output a second overvoltage protection signal when the bus voltage meets an overvoltage condition; The circuit further comprises: A hardware fault control module is connected to the overvoltage protection module, the low-side driver module, and the high-side driver module, and is used to output a first latch signal to the low-side driver module and a second latch signal to the high-side driver module when receiving the second overvoltage protection signal.

4. The circuit according to claim 3, characterized in that The circuit further includes a signal isolation module, which is connected between the overvoltage protection module and the hardware fault control module and is used to adjust the second overvoltage protection signal to within an input voltage range of the hardware fault control module.

5. The circuit according to claim 3, characterized in that The second overvoltage protection signal is a first control signal output by the overvoltage protection unit.

6. The circuit according to claim 3, characterized in that The first overvoltage protection signal and the second overvoltage protection signal are latched signals; the circuit further includes: A controller, configured to output a reset signal when determining that the bus voltage meets a safety voltage condition; A safety state reset module is connected to the controller and the overvoltage protection module, and is used to output a reset control signal to the overvoltage protection module when the reset signal is received; the overvoltage protection module is used to unlock and reset the first overvoltage protection signal and the second overvoltage protection signal when the reset control signal is received.

7. The circuit according to claim 6, characterized in that The circuit further comprises: A signal acquisition module is connected between the controller and the high-voltage bus, and is used to convert the collected bus voltage and send the converted voltage to the controller.

8. The circuit according to claim 7, characterized in that The signal acquisition module includes: a signal acquisition unit connected to the high-voltage bus and configured to acquire the bus voltage; A voltage regulating unit is connected to the controller and the signal acquisition unit, and is used to regulate the bus voltage to be within the input voltage range of the controller.

9. The circuit according to claim 6, characterized in that The circuit further includes a signal isolation module connected between the controller and the safety state reset module, and configured to adjust the reset signal to within an input voltage range of the safety state reset module.

10. The circuit according to claim 6, characterized in that The controller is connected to the low-side driver module and the high-side driver module, and is used to send a low-side driver signal to the low-side driver module, send a high-side driver signal to the high-side driver module, and send an alarm message in response to the fault signals fed back by the low-side driver module and the high-side driver module.

11. The circuit according to claim 1, wherein: The backup power supply module includes: a voltage conversion unit connected to the high-voltage bus and configured to convert the bus voltage into a backup power supply voltage; A unidirectional conducting unit, wherein a first end of the unidirectional conducting unit is connected to the voltage conversion unit, and a second end of the unidirectional conducting unit is connected to the low-side driving module.

12. A motor controller, characterized in that: The invention comprises the overvoltage protection circuit and the three-phase bridge circuit as described in any one of claims 1 to 11.

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