Protection circuit, motor control system and electric automobile

Abstract

The utility model provides a protection circuit, a motor control system and an electric automobile. The protection circuit comprises a logic processing module and a switching module. The control end of the switching module is used for receiving a first fault signal, the output end of the switching module is connected with the control end of the logic processing module, the input end of the logic processing module is used for connecting the first output end of the control circuit, and the output end of the logic processing module is used for connecting the switching circuit; wherein the switching module is configured to output a first level to the control end when a first fault signal is received, and output a second level to the control end when the first fault signal is not received; the control circuit is configured to generate a control signal for controlling the switch-on or switch-off of the switch circuit; the logic processing module is configured to output a control signal to the switching circuit when the second level is received, and does not output the control signal to the switching circuit when the first level is received. The protection circuit adopts a hardware circuit structure to realize protection action, and the software development complexity and cost can be reduced.

Description

TECHNICAL FIELD

[0001] The embodiment of the utility model relates to the technical field of circuit, especially relates to a protection circuit, motor control system and electric automobile. BACKGROUND

[0002] The motor control system is the device of controlling the energy transmission between the power supply (such as power battery) and driving motor. The motor control system can convert the direct current provided by the power battery into the alternating current required by the driving motor to meet the demand of motor operation.

[0003] In order to ensure the safe operation of the motor, the motor control system needs to perform relevant protection actions when abnormal conditions occur. At present, software algorithm control is usually used to perform protection actions, that is, the software reads the fault signal, then the fault signal is transmitted to the micro controller unit (MCU), and then the MCU performs the protection action. This method relies on software algorithm, that is, more complex software needs to be written and maintained, which increases the complexity of software development and maintenance cost. UTILITY MODEL CONTENT

[0004] The embodiment of the utility model provides a protection circuit, motor control system and electric automobile, which can reduce the complexity and cost of software.

[0005] In the first aspect, the utility model provides a protection circuit, which is applied to a motor control system, the motor control system includes a switching circuit and a control circuit, and the protection circuit includes a logic processing module and a switching module. The control end of the switching module is used for receiving a first fault signal, the output end of the switching module is connected to the control end of the logic processing module, the input end of the logic processing module is used for connecting the first output end of the control circuit, and the output end of the logic processing module is used for connecting the switching circuit. Wherein, the switching module is configured to output a first level to the control end when receiving the first fault signal, and output a second level to the control end when not receiving the first fault signal. The control circuit is configured to generate a control signal for controlling the switching circuit to be turned on or turned off. The logic processing module is configured to output the control signal to the switching circuit when the second level is received at the control end of the logic processing module, and not output the control signal to the switching circuit when the first level is received at the control end of the logic processing module.

[0006] In some embodiments, the switching circuit includes an upper bridge arm switching module and a lower bridge arm switching module, the control signal includes a first control sub-signal and a second control sub-signal, the first control sub-signal is used to control the upper bridge arm switching module to turn on or turn off, the second control sub-signal is used to control the lower bridge arm switching module to turn on or turn off, the logic processing module includes a first logic processing unit and a second logic processing unit; the input end of the first logic processing unit is used to connect the first output end of the control circuit, the first output end of the first logic processing unit is connected to the upper bridge arm switching module, the second output end of the first logic processing unit is connected to the input end of the second logic processing unit, the output end of the second logic processing unit is connected to the lower bridge arm switching module, and the first enable end of the first logic processing unit is used to connect the output end of the switching module; the first logic processing unit is configured to output the first control sub-signal to the upper bridge arm switching module and output the second control sub-signal to the second logic processing unit when the second level is received at the first enable end, and not output the first control sub-signal and the second control sub-signal when the first level is received at the first enable end; the second logic processing unit is configured to output the second control sub-signal to the lower bridge arm switching module when the second enable end of the second logic processing unit is the second level, and output a first conduction signal to the lower bridge arm switching module to turn on the lower bridge arm switching module when the second enable end is the first level.

[0007] In some embodiments, the logic processing module further includes a first switching unit and a pull-down resistor R231; the control end of the first switching unit is used to receive a second fault signal, the first end of the first switching unit is used to connect a first power supply end, the second end of the first switching unit is respectively connected to the first end of the pull-down resistor R231 and the second enable end of the second logic processing unit, and the second end of the pull-down resistor R231 is grounded; the first switching unit is configured to turn on when the second fault signal is received, to establish a connection between the first power supply end and the second enable end, and to make the second enable end be at the first level; the pull-down resistor R231 is configured to pull down the second enable end to the second level when the first switching unit is turned off.

[0008] In some embodiments, the second fault signal includes at least one of an active short circuit indication signal, a power supply fault signal, and an overvoltage fault signal.

[0009] In some embodiments, the logic processing module further comprises a second switch unit; a control end of the second switch unit is connected to a third output end of the first logic processing unit, a first end of the second switch unit is used for connecting an input end of the control circuit, and a second end of the second switch unit is grounded; the second switch unit is configured to be turned on or turned off based on a level of the third output end, so that the input end of the control circuit is grounded or not grounded, wherein the level of the third output end is the same as that of the first enable end.

[0010] In some embodiments, the switching module comprises a third switch unit and a pull-down resistor R136; a control end of the third switch unit is used for receiving the first fault signal, a first end of the third switch unit is used for connecting a first power supply end, and a second end of the third switch unit is connected to a control end of the logic processing module and a first end of the pull-down resistor R136 respectively, and a second end of the pull-down resistor R136 is grounded; the third switch unit is configured to be turned on when the first fault signal is received, to establish a connection between the first power supply end and the control end of the logic processing module, so that the control end of the logic processing module is at the first level; the pull-down resistor R136 is configured to pull down the control end of the logic processing module to the second level when the third switch unit is turned off.

[0011] In some embodiments, the switching module further comprises a fourth switch unit; a control end of the fourth switch unit is used for connecting a third output end of the control circuit, a first end of the fourth switch unit is connected to a control end of the logic processing module, and a second end of the fourth switch unit is grounded; the fourth switch unit is configured to be turned on when the second enable signal of the control circuit is received, to establish a connection between the control end of the logic processing module and the ground, so that the control end is at the second level.

[0012] In some embodiments, the first fault signal comprises at least one of a reset signal, a switching module drive fault signal, a three-phase overcurrent signal, a bus overvoltage signal, a power supply fault signal, and an active short circuit indication signal.

[0013] In the second aspect, the utility model embodiment provides a motor control system, the motor control system includes control circuit, switch circuit and the protection circuit of any one of the first aspect embodiment;The protection circuit is connected with control circuit and switch circuit respectively.

[0014] In the third aspect, the utility model embodiment provides an electric automobile, the electric automobile includes motor and the motor control system of the second aspect;The motor is connected with the motor control system.

[0015] Compared with the prior art, the utility model discloses the beneficial effect is: distinguish from the prior art, the utility model embodiment provides a protection circuit, motor control system and electric automobile, this protection circuit includes logic processing module and switching module, the control end of switching module is used to receive the first fault signal, the output of switching module connects the control end of logic processing module, the input of logic processing module is used to connect the first output of control circuit, the output of logic processing module is used to connect switch circuit, wherein, switching module is configured as when receiving the first fault signal, output first level to control end, when not receiving the first fault signal, output second level to control end, control circuit is configured as generating the control signal of control switch circuit conduction or shutdown, logic processing module is configured as when receiving second level, output control signal to switch circuit, when receiving first level, do not output control signal to switch circuit, this protection circuit adopts hardware circuit structure to realize the protection action of motion, can reduce software development complexity and cost. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example in the drawings in which like reference numerals refer to like elements / modules and steps throughout, and in which: the drawings are not necessarily to scale, except as otherwise noted.

[0017] Figure 1 is a structural block diagram of a motor control system provided by the utility model embodiment;

[0018] Figure 2 is a partial structure schematic view of a protection circuit provided by the utility model embodiment;

[0019] Figure 3 is a partial structure schematic view of another protection circuit provided by the utility model embodiment;

[0020] Figure 4 is a partial structure schematic view of still another protection circuit provided by the utility model embodiment;

[0021] Figure 5 is a partial structure schematic view of still another protection circuit provided by the utility model embodiment. DETAILED DESCRIPTION

[0022] The utility model will be explained in detail below in combination with specific embodiments. The following embodiments will help the person skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the utility model, a number of variations and improvements can be made. These all belong to the protection scope of the utility model.

[0023] For the convenience of understanding the present application, the present application is described in more detail below in conjunction with the drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the present specification includes any and all combinations of one or more related listed items.

[0024] It should be noted that, if there is no conflict, each feature in the embodiments of the utility model can be combined with each other, and all within the protection scope of the present application. In addition, although the functional modules are divided in the device schematic diagram, in some cases, the module division in the device can be different. In addition, the "first", "second" and the like used herein do not limit the data and execution order, and only distinguish the same items or similar items with basically the same function and action.

[0025] The latch and reset hardware protection sealing measures in the motor control system are important technologies to ensure the safe operation of the motor. The latch of the motor control system is used to lock the current state immediately when an abnormal condition is detected, to prevent further damage. The reset function is used to clear the previous fault information after troubleshooting, so that the motor control system returns to the normal operating state.

[0026] The commonly used latch and reset action is controlled by combining software algorithm, the fault is read by software, the signal is transmitted to MCU, and then the protection action is executed, which not only increases the complexity and maintenance cost of software development, but also needs a certain response time, in addition, due to environmental noise, electromagnetic interference and other reasons, the latch of the motor control system has the risk of false triggering.

[0027] In order to improve the above technical problems, the utility model embodiment provides a protection circuit, a motor control system and an electric vehicle, the circuit is handled to the fault signal through the special logic processing module and the switching module, does not need to adopt MCU to handle the fault signal, adopts the hardware structure to realize the protection action, can reduce the complexity on the software and the system cost, and improves the response speed.

[0028] In the first aspect, the utility model embodiment provides a protection circuit, the protection circuit is applied to the motor control system, referring to Figure 1 , the motor control system includes a control circuit 210 and a switching circuit 220, and the protection circuit 100 includes a logic processing module 110 and a switching module 120.

[0029] The control end of the switching module 120 is configured to receive a first fault signal, the output end of the switching module 120 is connected to the control end of the logic processing module 110, the input end of the logic processing module 110 is configured to be connected to the first output end of the control circuit 210, and the output end of the logic processing module 110 is configured to be connected to the switch circuit 220.

[0030] The switching module 120 is configured to output a first level to the control end when the first fault signal is received and output a second level to the control end when the first fault signal is not received. The control circuit 210 is configured to generate a control signal for controlling the switch circuit 220 to be turned on or turned off. The logic processing module 110 is configured to output the control signal to the switch circuit 220 when the second level is received at the control end of the logic processing module 110, and not output the control signal to the switch circuit 220 when the first level is received at the control end of the logic processing module 110.

[0031] As an example, in this application, the first level is high and the second level is low. In actual application, the first level can be low and the second level can be high.

[0032] In the motor control system, the switch circuit 220 includes an upper bridge arm switch module and a lower bridge arm switch module. The upper bridge arm switch module includes a U-phase upper switch tube, a V-phase upper switch tube, and a W-phase upper switch tube. The lower bridge arm switch module includes a U-phase lower switch tube, a V-phase lower switch tube, and a W-phase lower switch tube. The specific switch type and connection mode with the motor can refer to the prior art, which is not limited here.

[0033] The control circuit 210 includes an MCU, and the specific model can refer to the prior art, which is not limited here. The control signal can include a first control sub-signal for controlling the upper bridge arm switch module to be turned on or turned off, and a second control sub-signal for controlling the lower bridge arm switch module to be turned on or turned off. Specifically, refer to Figure 2 The first control sub-signal includes a pulse width modulation (PWM) signal MCU_PWM_HS_U for driving the U-phase upper switch tube, a PWM signal MCU_PWM_HS_V for driving the V-phase upper switch tube, and a PWM signal MCU_PWM_HS_W for driving the W-phase upper switch tube. The second control sub-signal includes a PWM signal MCU_PWM_LS_U for driving the U-phase lower switch tube, a PWM signal MCU_PWM_LS_V for driving the V-phase lower switch tube, and a PWM signal MCU_PWM_LS_W for driving the W-phase lower switch tube.

[0034] As shown in Figure 3 The first fault signal can include a reset signal

[0035] at least one of a reset signal M / SUPPLY_RESET / PQRST, a switch module drive fault signal, a three-phase over-current signal, a bus over-voltage signal OVP_TO_TO244, a power supply fault signal SBC_FS0B, and an active short-circuit indication signal MCU_LS_ASC. Among them, the reset signal

[0036] The reset signal M / SUPPLY_RESET / PQRST refers to a signal generated when the system needs to be reset to the initial state, which can be output by the control circuit 210. The switch module drive fault signal includes an upper bridge arm switch module drive fault signal DRV_HS_TO_MCU and a lower bridge arm switch module drive fault signal DRV_LS_TO_MCU. The upper bridge arm switch module drive fault signal DRV_HS_TO_MCU refers to a signal generated when any one of the U-phase upper switch tube, the V-phase upper switch tube, and the W-phase upper switch tube fails to drive, such as when any one of the upper switch tubes fails to normally turn on or off. The lower bridge arm switch module drive fault signal DRV_LS_TO_MCU refers to a signal generated when any one of the U-phase lower switch tube, the V-phase lower switch tube, and the W-phase lower switch tube fails to drive, such as when any one of the lower switch tubes fails to normally turn on or off. The three-phase over-current signal includes a U-phase over-current signal MCU_OC_U, a V-phase over-current signal MCU_OC_V, and a W-phase over-current signal MCU_OC_W. Among them, the U-phase over-current signal MCU_OC_U refers to a signal generated when the U-phase current exceeds a preset safety current threshold, the V-phase over-current signal MCU_OC_V refers to a signal generated when the V-phase current exceeds a preset safety current threshold, and the W-phase over-current signal MCU_OC_W refers to a signal generated when the W-phase current exceeds a preset safety current threshold. The bus over-voltage signal OVP_TO_TO244 refers to a signal generated when the voltage on the bus is greater than the maximum allowable voltage value, which can be output by the bus voltage sampling circuit for voltage sampling in the motor control system or the control circuit 210. The power supply fault signal SBC_FS0B refers to a signal generated when the power supply of the motor control system fails, which can be output by the power supply circuit in the motor control system or the control circuit 210. The active short-circuit indication signal MCU_LS_ASC refers to a signal generated when the system needs to actively short-circuit, which can be output by the control circuit 210 or a specific circuit.

[0037] The switching module 120 refers to a device that can change the level state of the output end when receiving the first fault signal, which can include a switching device, a switching chip, and other suitable devices.

[0038] The logic processing module 110 refers to a device capable of controlling the output of the control signal based on the level state of the control end of the logic processing module 110, which can include a logic processing chip, a switching device, and the like.

[0039] In the protection circuit 100, when the first fault signal is not received, the switching module 120 outputs the second level to the control end of the logic processing module 110, the logic processing module 110 normally outputs the control signal to the switching circuit 220, and the switching circuit 220 can be turned on or turned off based on the control signal, so that the motor can normally work based on the power supply. When the system fails, the switching module 120 receives the first fault signal, the switching module 120 outputs the first level to the control end of the logic processing module 110, at this time, the logic processing module 110 does not output the control signal to the switching circuit 220, the switching circuit 220 is in the off state, so that the motor cannot be powered, thereby realizing the protection of the motor.

[0040] It can be seen that in the protection circuit 100, the MCU is not needed, the protection action can be realized by using the hardware circuit, the software complexity and the cost can be reduced, and the response speed can be improved.

[0041] In some embodiments, referring to Figure 2 The logic processing module 110 includes a first logic processing unit 111 and a second logic processing unit 112. The input end of the first logic processing unit 111 is used to connect the first output end of the control circuit 210, the first output end of the first logic processing unit 111 is connected to the upper bridge arm switching module, the second output end of the first logic processing unit 111 is connected to the input end of the second logic processing unit 112, the output end of the second logic processing unit 112 is connected to the lower bridge arm switching module, and the first enable end of the first logic processing unit 111 is used to connect the output end of the switching module 120. The first logic processing unit 111 is configured to output the first control sub-signal to the upper bridge arm switching module and output the second control sub-signal to the second logic processing unit 112 when the first enable end receives the second level, and not output the first control sub-signal and the second control sub-signal when the first enable end receives the first level. The second logic processing unit 112 is configured to output the second control sub-signal to the lower bridge arm switching module when the second enable end of the second logic processing unit 112 is the second level, and output the first control signal to the lower bridge arm switching module when the second enable end is the first level, so as to turn on the lower bridge arm switching module.

[0042] Specifically, referring to Figure 2The first logic processing unit 111 can include a logic processing chip U1 with multiple input terminals and multiple output terminals, such as an SN74ACT244IPWRG4Q1 chip. The first enable terminal of the first logic processing unit 111 is the enable terminal OE1 and the enable terminal OE2 of the logic processing chip U1. Specifically, the control signals further include a switch circuit enable signal M_ENABLE_HS, which is used to control whether the switch circuit works or not. The multiple input terminals of the logic processing chip U1 are connected to the signal MCU_PWM_HS_U, the signal MCU_PWM_HS_V, the signal MCU_PWM_HS_W, the signal MCU_PWM_LS_U, the signal MCU_PWM_LS_V, the signal MCU_PWM_LS_W, and the signal M_ENABLE_HS, respectively. The multiple input terminals of the logic processing chip U1 are connected to each signal through current limiting resistors (R827, R828, …, R832) for limiting the current size. Meanwhile, part of the output terminals also output corresponding signals through current limiting resistors (R295, R301, R300, and R224). In addition, each input terminal is connected to a pull-down resistor (R833, R386, R387, R388, R391, R392, R393), and each output terminal is also connected to a pull-down resistor (R225, R228, R230, R268, R269, R270, R394). The above pull-down resistors can ground the corresponding input terminal or output terminal when the corresponding input signal or output signal level is uncertain, thereby ensuring the working reliability of the system.

[0043] Referring to Figure 4 The second logic processing unit 112 can include a logic processing chip U2 with multiple input terminals and multiple output terminals, such as a 74HC_HCT32_Q100 chip. The second enable terminal of the second logic processing chip U2 is the enable terminal 1B, the enable terminal 2B, and the enable terminal 3B of the logic processing chip U2. Specifically, the three input terminals (1A, 2A, 3A) of the logic processing chip U2 are connected to the three output terminals (1Y2, 1Y4, 2Y2) of the logic processing chip U1, respectively, to receive the three PWM signals for driving the lower bridge arm switch modules in the first logic processing unit 111. The first drive signal is a PWM signal with a duty cycle of 100%, such as a high-level signal.

[0044] In the protection circuit 100, when the logic processing chip U1 receives the input signals and the enable terminals (OE1 and OE2) of the logic processing chip U1 are both at low level, the logic processing chip U1 can normally output the input signals, i.e., the signals output from the output terminals are the signals input from the corresponding input terminals; when the enable terminals (OE1 and OE2) of the logic processing chip U1 are both at high level, the output terminals of the logic processing chip U1 will not output the PWM signals. In addition, when the logic processing chip U2 receives the signals output from the logic processing chip U1, if the enable terminal 1B, the enable terminal 2B and the enable terminal 3B of the logic processing chip U2 are all at low level, the logic processing chip U2 will normally output the input signals; if the enable terminal 1B, the enable terminal 2B and the enable terminal 3B of the logic processing chip U2 are all at high level, the output terminals of the logic processing chip U2 will all output the first conduction signals, so that the U-phase lower switch tube, the V-phase lower switch tube and the W-phase lower switch tube in the switch circuit will be continuously turned on, thereby realizing the short circuit.

[0045] In the logic processing module 110, whether to output the PWM signals can be determined by controlling the level signals of the first enable terminal of the first logic processing unit 111 and the second enable terminal of the second logic processing unit 112, thereby realizing the wave locking purpose of the PWM signals. In addition, when the second enable terminal signal is at the first level, the second logic processing unit 112 can output the first conduction signals, so that the three switch tubes of the lower bridge arm switch module are turned on, and the motor is short-circuited.

[0046] In some embodiments, referring to Figure 4 and Figure 5 , the logic processing module 110 further includes a first switch unit 113 and a pull-down resistor R231; the control terminal of the first switch unit 113 is used for receiving the second fault signal, the first terminal of the first switch unit 113 is used for connecting the first power supply terminal, the second terminal of the first switch unit 113 is respectively connected to the first terminal of the pull-down resistor R231 and the second enable terminal of the second logic processing unit 112, and the second terminal of the pull-down resistor R231 is grounded. The first switch unit 113 is configured to be turned on when the second fault signal is received, to establish the connection between the first power supply terminal and the second enable terminal, so that the second enable terminal is at the first level. The pull-down resistor R231 is configured to pull down the second enable terminal to the second level when the first switch unit 113 is turned off.

[0047] The second fault signal includes at least one of the active short circuit indication signal MCU_LS_ASC, the power supply fault signal SBC_FS0B and the over-voltage fault signal OVP_TO_TO244. As an example but not limitation, the second fault signal is all low level signals.

[0048] Specifically, referring to Figure 5, the first power terminal is a power terminal P5V MCU LS with a voltage of 5V, the first switch unit 113 includes a switch tube Q19, a control terminal of the switch tube Q19 is configured to receive a second fault signal, a first terminal of the switch tube Q19 is connected to the power terminal P5V MCU LS, and a second terminal of the switch tube Q19 is connected to a first terminal of a pull-down resistor R231, an enable terminal 1B, an enable terminal 2B and an enable terminal 3B of the logic processing chip U2. If the system generates the second fault signal, the control terminal of the switch tube Q19 is at a low level, the switch tube Q19 is turned on, the power terminal P5V MCU LS outputs a current to each enable terminal of the logic processing chip U2 through the switch tube Q19, and the logic processing chip U2 outputs a first conduction signal. If the system does not generate the second fault signal, the switch tube Q19 is turned off, each enable terminal of the logic processing chip U2 is pulled down to a low level by the pull-down resistor R231, and the logic processing chip U2 normally outputs based on an input signal.

[0049] The first switch unit 113 can further include appropriate devices such as resistors (R223, R294, R220, R222, R221, R293), capacitors (C231, C301, C232, C226, C225), diode pairs (D14, D17), and the type of the switch tube Q19 can be selected from appropriate devices such as PNP triodes. The specific circuit structure of the first switch unit 113 can refer to prior art, which is not limited herein.

[0050] In the embodiment, the second logic processing unit 112 can output a first conduction signal when the second enable terminal signal is at a first level, so as to turn on the three switch tubes of the lower bridge arm switch module, short-circuit the motor, and realize an active stability control (ASC) function. Compared with executing the ASC function through a special driving chip and a corresponding software algorithm, the embodiment realizes the ASC function by using a hardware circuit structure, which can reduce the complexity and cost of software and improve the response speed.

[0051] In some embodiments, referring to Figure 2 The logic processing module 110 further includes a second switch unit 114. A control terminal of the second switch unit 114 is connected to a third output terminal of the first logic processing unit 111, a first terminal of the second switch unit 114 is configured to be connected to an input terminal of the control circuit 210, and a second terminal of the second switch unit 114 is grounded. The second switch unit 114 is configured to be turned on or turned off based on a level of the third output terminal, so as to ground or not ground the input terminal of the control circuit 210, wherein the level of the third output terminal is the same as that of the first enable terminal.

[0052] Specifically, referring to Figure 2The second switch unit 114 includes a switch tube Q16, a control end of the switch tube Q16 is connected with an output end 2Y4 of the logic processing chip U1, a first end of the switch tube Q16 is connected with an input end of the control circuit 210, and a third end of the switch tube Q16 is grounded. The switch tube Q16 can be an NPN triode, and the second switch unit 114 can further include a pull-up resistor R143 connected between a 5V power supply end P5V_UC and the control end of the switch tube Q16, and a filter capacitor C179 connected between the switch tube Q16 and the ground.

[0053] In the circuit, when the enable ends (OE1 and OE2) of the logic processing chip U1 are low, the third output end is low, that is, the control end of the switch tube Q16 is low, the switch tube Q16 is off, and the input end of the control circuit 210 is not grounded; when the enable ends (OE1 and OE2) of the logic processing chip U1 are high, the third output end is high, that is, the control end of the switch tube Q16 is high, the switch tube Q16 is on, and the input end of the control circuit 210 is grounded. In this way, the control circuit 210 can detect the level signal of the input end to confirm whether the current logic processing module 110 is in the lock wave state.

[0054] In some embodiments, referring to Figure 3 The switching module 120 includes a third switch unit 121 and a pull-down resistor R136. A control end of the third switch unit 121 is configured to receive the first fault signal, a first end of the third switch unit 121 is configured to be connected with the first power supply end, a second end of the third switch unit 121 is respectively connected with a first end of the pull-down resistor R136 and the control end of the logic processing module 110, and a second end of the pull-down resistor R136 is grounded. The third switch unit 121 is configured to be on when the first fault signal is received, to establish a connection between the first power supply end and the control end of the logic processing module 110, so that the control end of the logic processing module 110 is at the first level. The pull-down resistor R136 is configured to pull down the control end of the logic processing module 110 to the second level when the third switch unit 121 is off.

[0055] Specifically, the first fault signal is a low-level signal, and the third switch unit 121 includes a switch tube Q15, a control end of the switch tube Q15 being configured to receive the first fault signal, a first end of the switch tube Q15 being connected to a first power supply end, such as a power supply end P5V UC with a voltage of 5V, and a second end of the switch tube Q15 being connected to the enable ends (OE1 and OE2) of the logic processing chip U1. The switch tube Q15 is turned on when receiving the low-level signal, and the first power supply end outputs to the enable ends (OE1 and OE2) of the logic processing chip U1 through the switch tube Q15, so that the enable ends (OE1 and OE2) of the logic processing chip U1 are at a high level. The switch tube Q15 is turned off when not receiving the low-level signal, and the enable ends (OE1 and OE2) of the logic processing chip U1 are pulled down to a low level through the resistor R136.

[0056] The switch tube Q15 can be a PNP triode or other suitable switching device, and the third switch unit 121 can further include resistors (R255, R202), capacitors (C387, C183, C348), diode pairs (D40, D31, D51, D16, D35), and other suitable devices.

[0057] In the switching module 120, the third switch unit 121 can be controlled to be turned on or turned off by the first fault signal, so as to switch the level of the control end of the logic processing module 110.

[0058] In some embodiments, referring to Figure 3 , the switching module 120 further includes a fourth switch unit 122. A control end of the fourth switch unit 122 is configured to be connected to a third output end of the control circuit 210, a first end of the fourth switch unit 122 is connected to the control end of the logic processing module 110, and a second end of the fourth switch unit 122 is grounded. The fourth switch unit 122 is configured to be turned on when receiving the second conduction signal of the control circuit 210, to establish a connection between the control end of the logic processing module 110 and the ground, so that the control end is at the second level.

[0059] Specifically, the fourth switch unit 122 includes a switch tube Q33, a control end of the switch tube Q33 being connected to the third output end of the control circuit 210, a first end of the switch tube Q33 being connected to the enable ends (OE1 and OE2) of the logic processing chip U1, and a second end of the switch tube Q33 being grounded. The second conduction signal is a high-level signal, and the switch tube Q33 is turned on when receiving the high-level signal, so that the control end is at the second level. The switch tube Q33 can be an NPN triode, and the fourth switch unit 122 can further include a current-limiting resistor R306 connected between the third output end of the control circuit 210 and the control end of the switch tube Q33, and a filter capacitor C346 connected between the switch tube Q33 and the ground.

[0060] In the switching module 120, the level of the control end of the logic processing module 110 can be switched by controlling the conduction or turn-off of the fourth switch unit 122, so that in the system debugging stage, the fourth switch unit 122 can be used to

[0061] The specific working process of the protection circuit 100 provided in the embodiment of the utility model will be described in detail below in combination with the embodiment shown in the drawings. Figures 2 to 5 The specific working process of the protection circuit 100 provided in the embodiment of the utility model will be described in detail below in combination with the embodiment shown in the drawings.

[0062] Firstly, when the system is normally working, the first fault signal and the second fault signal are not generated, and after receiving the PWM signals of the six switch tubes, the logic processing chip U1 and the logic processing chip U2 will normally output the PWM signals of the six switch tubes.

[0063] When one of the reset signal M_ / SUPPLY_RESET / PQRST, the switching module drive fault signal, the three-phase overcurrent signal, the bus overvoltage signal OVP_TO_TO244, the power supply fault signal SBC_FS0B and the active short-circuit indication signal MCU_LS_ASC is generated, referring to Figure 3 That is, the low-level first fault signal is input to the control end of the switch tube Q15, the control end of the switch tube Q15 is low, the switch tube Q15 is turned on, the enable end (OE1 and OE2) of the logic processing chip U1 is high, and the logic processing chip U1 will not output the PWM signals of the six switch tubes, so as to realize the purpose of latching fault and blocking protection.

[0064] When one of the active short-circuit indication signal MCU_LS_ASC, the power supply fault signal SBC_FS0B and the overvoltage fault signal OVP_TO_TO244 is generated, the logic processing chip U2 is involved Figure 5 That is, the low-level second fault signal is input to the control end of the switch tube Q19, the control end of the switch tube Q19 is low, the switch tube Q19 is turned on, the enable end 1B, the enable end 2B and the enable end 3B of the logic processing chip U2 are all high, and each output end of the logic processing chip U2 outputs the first conduction signal, so that the U-phase lower switch tube, the V-phase lower switch tube and the W-phase lower switch tube in the switching circuit are continuously turned on, and the ASC protection is realized.

[0065] It can be seen that in the embodiment, the logic processing chip U1 and the logic processing chip U2 can quickly respond to the fault signal and perform the protection action, without waiting for the software algorithm processing time, and can stably work in a harsh environment, so as to effectively protect the safe operation of the controller even in the software fault condition, can significantly improve the stability and performance of the equipment, and ensure the safe operation of the equipment in a complex electromagnetic environment.

[0066] In a second aspect, the utility model embodiments further provide a motor control system, the motor control system includes control circuit, switch circuit and the protection circuit as any one of the first aspect embodiment, the protection circuit is connected control circuit and switch circuit respectively.

[0067] In the embodiment, the protection circuit has the same structure and function as the protection circuit as any one of the first aspect embodiments, and details are not repeated here.

[0068] In a third aspect, the utility model embodiments further provide an electric vehicle, the electric vehicle includes motor and the motor control system as the second aspect, the motor is connected motor control system.

[0069] In the embodiment, the motor control system has the same structure and function as the motor control system as any one of the first aspect embodiments, and details are not repeated here.

[0070] It should be noted that the above-described device embodiments are only schematic, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e., they may be located in one place, or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0071] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; under the idea of the utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of the different aspects of the utility model as described above. In order to be brief, they are not provided in details; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A protection circuit, characterized in that: Applied to a motor control system, the motor control system includes a switch circuit and a control circuit, and the protection circuit includes: a logic processing module and a switching module; The control end of the switching module is used to receive the first fault signal, the output end of the switching module is connected to the control end of the logic processing module, the input end of the logic processing module is used to connect to the first output end of the control circuit, and the output end of the logic processing module is used to connect to the switch circuit; The switching module is configured to output a first level to the control end when the first fault signal is received, and output a second level to the control end when the first fault signal is not received; The control circuit is configured to generate a control signal to control the switch circuit to be turned on or off; The logic processing module is configured to output the control signal to the switch circuit when the control end of the logic processing module receives the second level, and not output the control signal to the switch circuit when the control end of the logic processing module receives the first level.

2. The protection circuit according to claim 1, wherein: The switching circuit includes an upper bridge arm switching module and a lower bridge arm switching module, the control signal includes a first control sub-signal and a second control sub-signal, the first control sub-signal is used to control the upper bridge arm switching module to be turned on or off, and the second control sub-signal is used to control the lower bridge arm switching module to be turned on or off, and the logic processing module includes a first logic processing unit and a second logic processing unit; The input end of the first logic processing unit is used to connect to the first output end of the control circuit, the first output end of the first logic processing unit is connected to the upper bridge arm switch module, the second output end of the first logic processing unit is connected to the input end of the second logic processing unit, the output end of the second logic processing unit is connected to the lower bridge arm switch module, and the first enable end of the first logic processing unit is used to connect to the output end of the switching module; The first logic processing unit is configured to output the first control sub-signal to the upper bridge arm switch module and output the second control sub-signal to the second logic processing unit when the first enable end receives the second level, and not output the first control sub-signal and the second control sub-signal when the first enable end receives the first level; The second logic processing unit is configured to output the second control sub-signal to the lower bridge arm switch module when the second enable terminal of the second logic processing unit is at a second level, and output the first conduction signal to the lower bridge arm switch module when the second enable terminal is at a first level, so as to turn on the lower bridge arm switch module.

3. The protection circuit according to claim 2, wherein: The logic processing module further includes a first switch unit and a pull-down resistor R231; The control end of the first switch unit is used to receive the second fault signal, the first end of the first switch unit is used to connect to the first power supply end, the second end of the first switch unit is respectively connected to the first end of the pull-down resistor R231 and the second enable end of the second logic processing unit, and the second end of the pull-down resistor R231 is grounded; The first switch unit is configured to be turned on upon receiving the second fault signal, to establish a connection between the first power terminal and the second enable terminal, and to make the second enable terminal at the first electrical level; The pull-down resistor R231 is configured to pull down the second enable terminal to the second level when the first switch unit is turned off.

4. The protection circuit according to claim 3, wherein: The second fault signal includes at least one of an active short circuit indication signal, a power supply fault signal, and an overvoltage fault signal.

5. The protection circuit according to claim 4, characterized in that: The logic processing module further includes a second switch unit; The control end of the second switch unit is connected to the third output end of the first logic processing unit, the first end of the second switch unit is used to connect to the input end of the control circuit, and the second end of the second switch unit is grounded; The second switch unit is configured to be turned on or off based on a level of the third output terminal to ground or disconnect the input terminal of the control circuit, wherein the level of the third output terminal is the same as the level of the first enable terminal.

6. The protection circuit according to any one of claims 1 to 5, characterized in that: The switching module includes a third switch unit and a pull-down resistor R136; The control end of the third switch unit is used to receive the first fault signal, the first end of the third switch unit is used to connect to the first power supply end, the second end of the third switch unit is respectively connected to the first end of the pull-down resistor R136 and the control end of the logic processing module, and the second end of the pull-down resistor R136 is grounded; The third switch unit is configured to be turned on upon receiving the first fault signal, to establish a connection between the first power supply terminal and the control terminal of the logic processing module, so that the control terminal of the logic processing module is at the first electrical level; The pull-down resistor R136 is configured to pull down the control terminal of the logic processing module to the second level when the third switch unit is turned off.

7. The protection circuit according to claim 6, characterized in that: The switching module further includes a fourth switch unit; The control end of the fourth switch unit is used to connect to the third output end of the control circuit, the first end of the fourth switch unit is connected to the control end of the logic processing module, and the second end of the fourth switch unit is grounded; The fourth switch unit is configured to be turned on upon receiving a second turn-on signal from the control circuit, to establish a connection between the control terminal of the logic processing module and the ground, so that the control terminal is at the second electrical level.

8. The protection circuit according to claim 6, wherein: The first fault signal includes at least one of a reset signal, a switch module drive fault signal, a three-phase overcurrent signal, a bus overvoltage signal, a power supply fault signal, and an active short circuit indication signal.

9. A motor control system, characterized in that: comprising a control circuit, a switch circuit and a protection circuit according to any one of claims 1 to 8; The protection circuit is connected to the control circuit and the switch circuit respectively.

10. An electric vehicle, characterized in that: comprising a motor, and a motor control system as claimed in claim 9; The motor is connected to the motor control system.

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