Short-circuit protection circuit and vehicle system

Abstract

The invention discloses a short circuit protection circuit and a vehicle system. The short-circuit protection circuit comprises a short-circuit detection circuit, an isolation circuit and a control unit, the short-circuit detection circuit is used for acquiring a voltage signal of a detection point; the isolation circuit is used for receiving the voltage signal and transmitting the voltage signal to the control unit; the control unit is used for receiving the voltage signal and outputting a forbidding signal to the motor driving unit when the voltage signal meets the short circuit condition. According to the technical scheme, the short-circuit detection circuit, the isolation circuit and the control unit are arranged in the short-circuit protection circuit, the short-circuit detection circuit obtains the voltage signal in the to-be-detected loop in real time, the isolation circuit isolates the to-be-detected loop and the control unit, and the control unit judges whether a short-circuit fault occurs or not according to the voltage signal; and after a short-circuit fault occurs, a prohibition signal is output to the motor driving unit, so that the short-circuit protection circuit can realize short-circuit detection and protection functions under a low-voltage condition, and the driving safety of the vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of short circuit detection, and in particular to a short circuit protection circuit and a vehicle system. Background Art

[0002] With the continuous development of new energy technology, the proportion of new energy vehicles is increasing. Compared with traditional fuel vehicles, new energy vehicles have added high-voltage systems. The motor controller, motor, and battery together constitute the core power system of new energy vehicles. In order to better protect personnel and equipment safety, short-circuit detection and protection design of the high-voltage system is required.

[0003] The existing technology mainly performs short circuit detection during high voltage output, which has high hardware cost and still poses safety risks. Summary of the invention

[0004] The present invention provides a short-circuit protection circuit and a vehicle system to solve the problem that the short-circuit detection in the prior art occurs during the high-voltage output process and has potential safety hazards.

[0005] According to one aspect of the present invention, there is provided a short circuit protection circuit, comprising: a short circuit detection circuit, an isolation circuit and a control unit;

[0006] The short circuit detection circuit is electrically connected to the detection point to obtain a voltage signal at the detection point; wherein the detection point is a point on the circuit to be detected;

[0007] The isolation circuit is electrically connected to the short-circuit detection circuit and the control unit respectively, and is used to receive the voltage signal and transmit the voltage signal to the control unit;

[0008] The control unit is also electrically connected to the motor drive unit, and is used to receive a voltage signal and output a prohibition signal to the motor drive unit when the voltage signal meets a short-circuit condition, so as to prohibit the motor from working.

[0009] Optionally, the circuit to be tested includes a high-voltage terminal and a casing; the test point is a point on the circuit connecting the high-voltage terminal and the casing.

[0010] Optionally, the high-voltage terminal includes at least two; a switch unit is provided in series on the circuit between each high-voltage terminal and the housing;

[0011] The control unit is also electrically connected to the switch unit, and is used to control the switch unit to turn on in sequence and receive voltage signals on the corresponding high-voltage terminals and the housing loop, and determine whether the corresponding voltage signal meets the short-circuit condition.

[0012] Optionally, the high-voltage terminal includes a positive high-voltage terminal of a power supply, a negative high-voltage terminal of a power supply, a U-phase high-voltage terminal of a motor, a V-phase high-voltage terminal of a motor, and a W-phase high-voltage terminal of a motor.

[0013] Optionally, the circuit to be detected includes a first high-voltage terminal and a second high-voltage terminal; the detection point is a point on the circuit connecting the first high-voltage terminal and the second high-voltage terminal.

[0014] Optionally, the first high-voltage terminal includes at least two; each first high-voltage terminal is electrically connected to the second high-voltage terminal and a switch unit is provided in series on the loop between each first high-voltage terminal and the second high-voltage terminal;

[0015] The control unit is also electrically connected to the switch unit, and is used to control the switch unit to turn on in sequence and receive voltage signals on the corresponding first high-voltage terminal and second high-voltage terminal loops, and determine whether the corresponding voltage signals meet the short-circuit condition.

[0016] Optionally, the switch unit is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor.

[0017] Optionally, the short-circuit protection circuit further includes a clamping protection circuit; the clamping protection circuit is arranged on a loop between the isolation circuit and the control unit and is connected in parallel with the control unit;

[0018] The clamping protection circuit includes two voltage-stabilizing diodes which are arranged in series at a power supply terminal and a ground terminal.

[0019] Optionally, the isolation circuit includes a voltage follower circuit; the voltage follower circuit includes an operational amplifier;

[0020] The first input terminal of the operational amplifier is electrically connected to the short-circuit detection circuit, the second input terminal is electrically connected to the output terminal, and the output terminal is electrically connected to the control unit.

[0021] According to another aspect of the present invention, there is provided a vehicle system, comprising a short circuit protection circuit; and further comprising: a motor and a motor driver;

[0022] The motor driver comprises a motor driving unit, and the short circuit protection circuit is arranged in the motor driver.

[0023] The technical solution of the present invention is to set a short-circuit detection circuit, an isolation circuit and a control unit in the short-circuit protection circuit. The short-circuit detection circuit obtains the voltage signal in the circuit to be detected in real time, the isolation circuit isolates the circuit to be detected and the control unit, and the control unit determines whether a short-circuit fault occurs according to the voltage signal, and outputs a prohibition signal to the motor drive unit after the short-circuit fault occurs, so that the short-circuit protection circuit can realize short-circuit detection and protection functions under low-voltage conditions, thereby improving the safety of the short-circuit detection process and ensuring the driving safety of the vehicle.

[0024] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 is a connection diagram of a first short-circuit protection circuit provided by an embodiment of the present invention;

[0027] Figure 2 is a connection diagram of a second short-circuit protection circuit provided according to an embodiment of the present invention;

[0028] Figure 3 4 is a connection diagram of a third short-circuit protection circuit provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0031] Figure 1 is a connection diagram of a first short-circuit protection circuit provided according to an embodiment of the present invention, Figure 2 1 is a connection diagram of a second short-circuit protection circuit provided according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the short circuit protection circuit comprises: a short circuit detection circuit 1, an isolation circuit 2 and a control unit 3;

[0032] The short circuit detection circuit 1 is electrically connected to the detection point A, and is used to obtain the voltage signal of the detection point A; wherein the detection point A is a point on the circuit 4 to be detected;

[0033] The isolation circuit 2 is electrically connected to the short-circuit detection circuit 1 and the control unit 3, respectively, and is used to receive a voltage signal and transmit the voltage signal to the control unit 3;

[0034] The control unit 3 is also electrically connected to the motor drive unit 5 for receiving a voltage signal and outputting a prohibition signal to the motor drive unit 5 when the voltage signal meets a short-circuit condition, so as to prohibit the motor from operating.

[0035] The short circuit detection circuit 1 is electrically connected to the detection point A, and the isolation circuit 2 is electrically connected to the short circuit detection circuit 1 and the control unit 3. The short circuit detection circuit 1 obtains the voltage signal of the detection point A and transmits the voltage signal to the control unit 3 through the isolation circuit 2.

[0036] Among them, the circuit to be detected 4 is a circuit for real-time monitoring of the short-circuit protection circuit, and the voltage on the circuit can be high voltage or low voltage. The control unit 3 can be a microcontroller or a digital signal processor. By powering the control unit 3 in a low-voltage environment, the control unit 3 can be turned on so that the control unit 3 works normally. Therefore, the control unit 3 can start working when the vehicle is powered on, and then the short circuit detection can be completed in the low-voltage environment when the vehicle is powered on. The isolation circuit 2 is used to isolate the voltage of the circuit to be detected 4 and the voltage of the control unit 3. Since the voltage of the circuit to be detected 4 can be low voltage or high voltage, and the voltage of the control unit 3 is low voltage, the isolation circuit 2 is set to ensure the normal operation of the short-circuit protection circuit.

[0037] Among them, the voltage signal when the circuit to be detected 4 is short-circuited is different from the voltage signal when the circuit to be detected 4 is normal. The control unit 3 can determine whether the circuit to be detected 4 is short-circuited by acquiring and judging the voltage signal, and output a prohibition signal to the motor drive unit 5 when a short circuit fault occurs, prohibiting the motor drive unit 5 from driving the motor to work.

[0038] It can be understood that the short-circuit protection circuit can detect both low-voltage circuits and high-voltage circuits, and can operate in a low-voltage environment. Therefore, the short-circuit protection circuit can be set in the motor driver and can complete the detection of the circuit in the motor driver under low-voltage conditions. Exemplarily, the short-circuit protection circuit is set in the motor driver to detect whether a short circuit occurs between the high-voltage terminal and the housing. The short-circuit detection circuit 1 is electrically connected to a point on the loop between the high-voltage terminal and the housing, obtains the voltage signal of the detection point A and transmits the voltage signal to the control unit 3 through the isolation circuit 2. The control unit 3 then determines whether a short circuit occurs between the high-voltage terminal and the housing. When a short circuit occurs, a prohibition signal is output to the motor drive unit 5 to prohibit the motor from running.

[0039] It is understandable that in new energy vehicle systems, since they rely on motors to provide power, whether the motors can operate safely is crucial to the safety of the vehicle. The short-circuit protection circuit in the embodiment of the present invention can be set in the motor driver and perform short-circuit detection when the vehicle is powered on and the motor is not running. That is, short-circuit faults are monitored in real time under low-voltage conditions before the entire machine is powered on by high voltage, and the motor is prohibited from running when a short-circuit fault occurs, thereby ensuring vehicle safety.

[0040] The technical solution of the embodiment of the present invention is to set a short-circuit detection circuit, an isolation circuit and a control unit in the short-circuit protection circuit. The short-circuit detection circuit obtains the voltage signal in the circuit to be detected in real time, the isolation circuit isolates the circuit to be detected and the control unit, and the control unit determines whether a short-circuit fault occurs according to the voltage signal, and outputs a prohibition signal to the motor drive unit after a short-circuit fault occurs, so that the short-circuit protection circuit can realize short-circuit detection and protection functions under low-voltage conditions, thereby improving the safety of the short-circuit detection process and ensuring the driving safety of the vehicle.

[0041] Optional, continue to refer to Figure 1 and Figure 2 As shown, the circuit 4 to be detected includes a high voltage terminal 41 and a housing 42 ; the detection point A is a point on the circuit where the high voltage terminal 41 and the housing 42 are connected.

[0042] Among them, the housing 42 may refer to a vehicle frame, which includes a motor housing 42 body, and the frame is generally grounded to ensure vehicle safety. Under normal circumstances, the high-voltage terminal 41 and the housing 42 are in an open circuit state, so the voltage signal obtained by the short-circuit detection circuit 1 is a fixed value. The control unit 3 does not take action after receiving this voltage signal, and the short-circuit protection circuit operates normally. When a short-circuit abnormality occurs, the voltage signal of the short-circuit detection point A between the high-voltage terminal 41 and the housing 42 is 0. At this time, the control unit 3 recognizes that the voltage signal is 0, determines that a short-circuit fault occurs, and outputs a prohibition signal to the motor drive unit 5.

[0043] It can be understood that the high voltage terminal 41 is powered by high voltage, and the control unit 3 is powered by low voltage power, so the short circuit detection and protection function under low voltage conditions is realized.

[0044] The technical solution of the embodiment of the present invention, by setting the short-circuit detection circuit between the high-voltage terminal and the casing, realizes real-time monitoring of short-circuit faults under low-voltage conditions before the whole machine is powered by high voltage, and prohibits the motor from running when a short-circuit fault occurs, thereby ensuring vehicle safety.

[0045] Optional, continue to refer to Figure 1 and Figure 2 As shown, the high-voltage terminal 41 includes at least two; a switch unit T is arranged in series on the circuit of each high-voltage terminal 41 and the housing 42;

[0046] The control unit 3 is also electrically connected to the switch unit T, and is used to control the switch unit T to open in sequence and receive the voltage signal on the corresponding high-voltage terminal 41 and the housing 42 circuit, and determine whether the corresponding voltage signal meets the short-circuit condition.

[0047] Among them, when the high-voltage terminal 41 includes at least two, in order to accurately detect the short-circuit position, each high-voltage terminal 41 is electrically connected to the housing 42 and a switch unit T is arranged in series on the circuit between each high-voltage terminal 41 and the housing 42. The control unit 3 is electrically connected to the switch unit T, and the switch unit T of each high-voltage terminal 41 is controlled to be turned on in sequence so that the voltage signal on the circuit between the high-voltage terminal 41 and the housing 42 enters the control unit 3 in sequence. The control unit 3 can determine whether a short-circuit fault occurs and which high-voltage terminal 41 and the housing 42 circuit has a fault based on the voltage signal.

[0048] In some embodiments, the high-voltage terminal 41 includes a positive high-voltage terminal of a power supply, a negative high-voltage terminal of a power supply, a U-phase high-voltage terminal of a motor, a V-phase high-voltage terminal of a motor, and a W-phase high-voltage terminal of a motor. Corresponding switch units T are respectively set on the circuits between the positive high-voltage terminal of the power supply, the negative high-voltage terminal of the power supply, the U-phase high-voltage terminal of the motor, the V-phase high-voltage terminal of the motor, and the W-phase high-voltage terminal of the motor and the housing 42, and the switch units T are controlled to be turned on in sequence according to the timing, that is, T1, T2, T3, T4 and T5 are turned on in sequence, so that the voltage signals on the corresponding circuits of the positive high-voltage terminal of the power supply, the negative high-voltage terminal of the power supply, the U-phase high-voltage terminal of the motor, the V-phase high-voltage terminal of the motor, and the W-phase high-voltage terminal of the motor enter the control unit 3 in sequence, and the control unit 3 can then determine the position where the short circuit occurs according to the timing, that is, which high-voltage terminal 41 has a short circuit with the housing 42.

[0049] In some embodiments, the switch unit T is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor. When one switch unit T is turned on, the other switch units T are in a closed state, thereby ensuring the accuracy of the short circuit protection circuit in determining the short circuit position.

[0050] The technical solution in the embodiment of the present invention is to set a switch unit in a scenario of at least two high-voltage terminals, set the switch unit in series on the loop of the casing and the high-voltage terminal and control the switch units to be turned on in sequence, so that the control unit can accurately locate the loop where the short circuit occurs, thereby improving the accuracy of short-circuit detection; at the same time, after the switch unit is set, all the switch units are only used in one set of short-circuit detection circuit, isolation circuit and control unit, which ensures the short-circuit detection function while saving hardware costs.

[0051] Optional, Figure 3 is a connection diagram of a third short-circuit protection circuit provided according to an embodiment of the present invention, combined with Figure 1 and Figure 3As shown, the circuit to be detected 4 includes a first high-voltage terminal 411 and a second high-voltage terminal 412 ; the detection point A is a point on the circuit where the first high-voltage terminal 411 and the second high-voltage terminal 412 are connected.

[0052] The short-circuit protection circuit can also detect whether a short circuit occurs in the loop between the high-voltage terminals 41. A first high-voltage terminal 411 and a second high-voltage terminal 412 are provided in the loop 4 to be detected, and a short-circuit detection circuit 1 is provided on the loop of the first high-voltage terminal 411 and the second high-voltage terminal 412. By detecting the change in the voltage signal after normal operation and a short-circuit fault occurs, it is determined whether a short-circuit fault occurs between the high-voltage terminals 41.

[0053] It can be understood that the high voltage terminal 41 is powered by high voltage, and the control unit 3 is powered by low voltage power, so the short circuit detection and protection function under low voltage conditions is realized.

[0054] The technical solution of the embodiment of the present invention, by setting the short-circuit detection circuit between the high-voltage terminal and the high-voltage terminal, realizes real-time monitoring of short-circuit faults under low-voltage conditions before the whole machine is powered by high voltage, and prohibits the motor from running when a short-circuit fault occurs, thereby ensuring the safety of the vehicle.

[0055] Optional, continue to refer to Figure 1 and Figure 3 As shown, the first high-voltage terminal 411 includes at least two; each first high-voltage terminal 411 is electrically connected to the second high-voltage terminal 412, and a switch unit T is arranged in series on the loop of each first high-voltage terminal 411 and the second high-voltage terminal 412;

[0056] The control unit 3 is also electrically connected to the switch unit T, and is used to control the switch unit T to turn on in sequence and receive the voltage signals on the corresponding first high voltage terminal 411 and second high voltage terminal 412 loops, and determine whether the corresponding voltage signals meet the short circuit condition.

[0057] When there are at least two first high-voltage terminals 411, in order to accurately detect the short-circuit position, a switch unit T is serially arranged on the loop between each first high-voltage terminal 411 and the second high-voltage terminal 412. The control unit 3 is electrically connected to the switch unit T, and controls the switch unit T corresponding to each first high-voltage terminal 411 to be turned on in sequence, so that the voltage signals on the loops of the first high-voltage terminal 411 and the second high-voltage terminal 412 enter the control unit 3 in sequence. The control unit 3 can determine whether a short-circuit fault occurs and which loop corresponding to the first high-voltage terminal 411 fails according to the voltage signal.

[0058] It is understandable that the second high-voltage terminal 412 can be one or at least two. When there is one second high-voltage terminal 412, by setting the switch unit T in combination with the control unit 3, the voltage signal can be used to determine whether a short circuit fault occurs and which circuit corresponding to the first high-voltage terminal 411 and the second high-voltage terminal 412 fails, that is, accurately locate the circuit between the high-voltage terminals 41 where the fault occurs. When there are at least two second high-voltage terminals 412, by setting the switch unit T corresponding to the number of first high-voltage terminals 411, one first high-voltage terminal 411 is connected to multiple second high-voltage terminals 412, and in combination with the control unit 3, it can be determined whether a short circuit fault occurs in the circuit between the high-voltage terminals 41, but it is impossible to locate the specific circuit.

[0059] Exemplarily, the first high-voltage terminal 411 includes a positive high-voltage terminal of a power supply, a negative high-voltage terminal of a power supply, a U-phase high-voltage terminal of a motor, a V-phase high-voltage terminal of a motor, and a W-phase high-voltage terminal of a motor. The second high-voltage terminal 412 also includes a positive high-voltage terminal of a power supply, a negative high-voltage terminal of a power supply, a U-phase high-voltage terminal of a motor, a V-phase high-voltage terminal of a motor, and a W-phase high-voltage terminal of a motor. T1, T2, T3, T4, and T5 switch units are set corresponding to the number of first high-voltage terminals 411. The switch unit T is connected to the second high-voltage terminal 412 through a detection point A, so as to control the conduction of the T1, T2, T3, T4, and T5 switch units, so that the voltage signals on the corresponding circuits of the positive high-voltage terminal of the power supply, the negative high-voltage terminal of the power supply, the U-phase high-voltage terminal of the motor, the V-phase high-voltage terminal of the motor, and the W-phase high-voltage terminal of the motor in the first high-voltage terminal 411 enter the control unit 3 in sequence. The control unit 3 can then determine which circuit corresponding to the first high-voltage terminal 411 is short-circuited according to the timing, that is, perform short-circuit detection between the high-voltage terminals 41.

[0060] In some embodiments, the switch unit T is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor. When one switch unit T is turned on, the other switch units T are in a closed state, thereby ensuring the accuracy of the short circuit protection circuit in determining the short circuit position.

[0061] The technical solution in the embodiment of the present invention is to set a switch unit in a scenario of at least two first high-voltage terminals, set the switch unit in series on the loop of the first high-voltage terminal and the second high-voltage terminal and control the switch units to be turned on in sequence, so that the control unit can detect whether a short circuit occurs between the high-voltage terminals, thereby improving the accuracy of short-circuit detection; at the same time, after the switch unit is set, all the switch units T are only used in one set of short-circuit detection circuit, isolation circuit and control unit, which ensures the short-circuit detection function while saving hardware costs.

[0062] Optional, continue to refer to Figure 1 and Figure 2As shown, the short-circuit protection circuit further includes a clamping protection circuit 7; the clamping protection circuit 7 is arranged on the loop of the isolation circuit 2 and the control unit 3 and is connected in parallel with the control unit 3;

[0063] The clamping protection circuit 7 includes two voltage-stabilizing diodes connected in series at a power supply terminal VCC3 and a ground terminal.

[0064] Among them, the clamping protection circuit 7 can be used to limit the voltage entering the control unit 3. The clamping protection circuit 7 is set in the loop of the isolation circuit 2 and the control unit 3 and is connected in parallel with the control unit 3 to prevent the excessive voltage signal from affecting the normal operation of the control unit 3.

[0065] Specifically, the clamping protection circuit 7 includes two voltage regulator diodes D1 connected in series at the power supply terminal VCC3 and the ground terminal, so that the voltage value entering the control unit 3 is limited between 0 and VCC3, thereby ensuring the normal operation of the control unit 3.

[0066] The technical solution of the embodiment of the present invention provides a clamping protection circuit in the short-circuit protection circuit to limit the voltage entering the control unit, thereby protecting the control unit and ensuring the normal operation of the control unit.

[0067] Optionally, the isolation circuit 2 includes a voltage follower circuit; the voltage follower circuit includes an operational amplifier IC1;

[0068] The first input terminal of the operational amplifier IC1 is electrically connected to the short-circuit detection circuit 1 , the second input terminal is electrically connected to the output terminal, and the output terminal is electrically connected to the control unit 3 .

[0069] Among them, the voltage signal collected by the short-circuit detection circuit 1 enters the operational amplifier IC1 of the voltage follower circuit, the first input terminal of the operational amplifier IC1 is electrically connected to the short-circuit detection circuit 1, the second input terminal is electrically connected to the output terminal, and the output terminal is electrically connected to the control unit 3, and the voltage signal is input into the control unit 3 through the operational amplifier IC1.

[0070] In some embodiments, a first resistor R4 is connected in series between the second input terminal and the output terminal of the operational amplifier IC1 .

[0071] In some embodiments, the short circuit detection circuit 1 includes a second resistor R2, a third resistor R1 and a fourth resistor R3, the second resistor R2 is arranged in series in the loop to be detected 4 and in series with the detection point A, and the second resistor R2, the detection point A and the third resistor R1 are arranged in series between the first power supply terminal and the ground terminal. The fourth resistor R3 is connected in series between the first input terminal of the operational amplifier IC1 and the detection point A, and capacitors are connected in parallel to the first resistor and the fourth resistor R3, so as to realize the detection protection function of the short circuit protection circuit.

[0072] The technical solution of the embodiment of the present invention realizes the function of isolating and transmitting voltage signals by setting a voltage follower circuit in the isolation circuit and setting an operational amplifier in the voltage follower circuit, thereby ensuring that the short-circuit protection circuit can realize short-circuit detection and protection functions under low-voltage conditions, thereby improving the driving safety of the vehicle.

[0073] Based on the same inventive concept, an embodiment of the present invention further provides a vehicle system, including a short-circuit protection circuit; and further including: a motor and a motor driver;

[0074] The motor driver comprises a motor driving unit, and the short circuit protection circuit is arranged in the motor driver.

[0075] Among them, the vehicle system can be a new energy vehicle system. In the new energy vehicle system, since the motor driver, motor and battery together constitute the core power system of the new energy vehicle, the safety of the motor operation is crucial to the safety of the entire vehicle.

[0076] Specifically, a short-circuit protection circuit is set in the motor driver, and the control unit is connected to the motor drive unit. When the control unit determines that a short-circuit fault occurs, the motor is prohibited from running in time, thereby avoiding losses caused by the failure of protection measures to work in time and improving the safety of the vehicle system.

[0077] The technical solution of the embodiment of the present invention is to set a short-circuit detection circuit, an isolation circuit and a control unit in the short-circuit protection circuit. The short-circuit detection circuit obtains the voltage signal in the circuit to be detected in real time, the isolation circuit isolates the circuit to be detected and the control unit, and the control unit determines whether a short-circuit fault occurs according to the voltage signal, and outputs a prohibition signal to the motor drive unit after a short-circuit fault occurs, so that the short-circuit protection circuit can realize short-circuit detection and protection functions under low-voltage conditions, thereby improving the safety of the short-circuit detection process and ensuring the driving safety of the vehicle.

[0078] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A short circuit protection circuit, characterized in that: include: Short circuit detection circuit, isolation circuit and control unit; The short circuit detection circuit is electrically connected to a detection point, and is used to obtain a voltage signal of the detection point; wherein the detection point is a point on the circuit to be detected; The isolation circuit is electrically connected to the short-circuit detection circuit and the control unit respectively, and is used to receive the voltage signal and transmit the voltage signal to the control unit; The control unit is also electrically connected to the motor drive unit, and is used to receive the voltage signal and output a prohibition signal to the motor drive unit when the voltage signal meets a short-circuit condition, so as to prohibit the motor from working.

2. The short circuit protection circuit according to claim 1, characterized in that: The circuit to be detected includes a high-voltage terminal and a housing; the detection point is a point on the connection circuit between the high-voltage terminal and the housing.

3. The short circuit protection circuit according to claim 2, characterized in that: The high-voltage terminals include at least two; a switch unit is provided in series on each of the high-voltage terminals and the circuit of the housing; The control unit is also electrically connected to the switch unit, and is used to control the switch unit to turn on in sequence and receive voltage signals corresponding to the high-voltage terminal and the housing loop, and determine whether the corresponding voltage signal meets the short-circuit condition.

4. The short circuit protection circuit according to claim 3, characterized in that: The high-voltage terminals include a positive high-voltage terminal of a power supply, a negative high-voltage terminal of a power supply, a U-phase high-voltage terminal of a motor, a V-phase high-voltage terminal of a motor, and a W-phase high-voltage terminal of a motor.

5. The short circuit protection circuit according to claim 1, characterized in that: The circuit to be detected includes a first high-voltage terminal and a second high-voltage terminal; the detection point is a point on the circuit connecting the first high-voltage terminal and the second high-voltage terminal.

6. The short circuit protection circuit according to claim 5, characterized in that: The first high-voltage terminals include at least two; each of the first high-voltage terminals is electrically connected to the second high-voltage terminal, and a switch unit is provided in series on the loop of each of the first high-voltage terminal and the second high-voltage terminal; The control unit is also electrically connected to the switch unit, and is used to control the switch unit to turn on in sequence and receive voltage signals corresponding to the first high-voltage terminal and the second high-voltage terminal loops, and determine whether the corresponding voltage signals meet the short-circuit condition.

7. The short circuit protection circuit according to claim 3 or 6, characterized in that: The switch unit is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor.

8. The short circuit protection circuit according to claim 1, characterized in that: The short circuit protection circuit further comprises a clamp protection circuit; the clamp protection circuit is arranged on the loop of the isolation circuit and the control unit and is connected in parallel with the control unit; The clamping protection circuit includes two voltage-stabilizing diodes which are connected in series at a power supply terminal and a ground terminal.

9. The short circuit protection circuit according to claim 1, characterized in that: The isolation circuit includes a voltage follower circuit; the voltage follower circuit includes an operational amplifier; The first input terminal of the operational amplifier is electrically connected to the short-circuit detection circuit, and the second input terminal is electrically connected to the output terminal; the output terminal is electrically connected to the control unit.

10. A vehicle system, characterized in that: The short circuit protection circuit comprises any one of claims 1 to 9; and further comprises: a motor and a motor driver; The motor driver includes the motor driving unit, and the short-circuit protection circuit is arranged in the motor driver.

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