WO2019034132A1

WO2019034132A1 - Protection apparatus for electric motor controller, electric motor controller and electric automobile

Info

Publication number: WO2019034132A1
Application number: PCT/CN2018/100940
Authority: WO
Inventors: 林海文; 黄炳健; 丁志龙; 尹修冲
Original assignee: 比亚迪股份有限公司
Priority date: 2017-08-17
Filing date: 2018-08-17
Publication date: 2019-02-21
Also published as: CN109412118A; CN109412118B

Abstract

Disclosed are an electric motor controller and a protection apparatus therefor, and an electric automobile. The electric motor controller comprises a three-phase inverter bridge and a control chip. The control chip is used for collecting a three-phase current and a direct-current bus voltage of an electric motor. The protection apparatus comprises: a current comparison circuit connected to the control chip, for outputting a first comparison signal when the three-phase current of the electric motor is greater than a pre-set current threshold; a voltage comparison circuit connected to the control chip, for outputting a second comparison signal when the direct-current bus voltage is greater than a pre-set voltage threshold; a passage selection chip respectively connected to the current comparison circuit, the voltage comparison circuit, the control chip and the three-phase inverter bridge, for receiving six PWM signals output by the control chip, and gating the six PWM signals according to at least one of the first comparison signal and the second comparison signal.

Description

Protection device for motor controller, motor controller and electric vehicle

Cross-reference to related applications

The present application is based on a Chinese patent application filed on Jan. 17, 2017, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present application relates to the field of electric vehicles, and in particular to a protection device for a motor controller, a motor controller and an electric vehicle.

Background technique

When the motor controller controls the motor, the control chip such as DSP (Digital Signal Processing) generates six PWM (Pulse Width Modulation) waves to drive the switching transistors IGBT1 to IGBT6 in the three-phase inverter bridge. The inverter function is implemented to drive the motor, as shown in Figure 1. The DSP collects and detects the motor speed, the DC bus voltage and the motor three-phase current while generating six PWM waves. When an overvoltage or overcurrent occurs and the motor speed is detected to be high, the DSP will adjust the output of the six PWM waves. The three-phase six-way PWM wave is short-circuited three-phase to the switch tube to prevent the high back electromotive force of the motor from damaging the switch tube, thereby achieving the purpose of protecting the switch tube.

In the related art, the above-mentioned three-phase short circuit of the switch tube is realized by software, and the DSP judges according to the collected voltage and current signals to make an action. However, the software implementation protection function has the disadvantages of action delay and unreliability. That is to say, the response time of the software is far greater than the response time of the hardware circuit, which may cause the action delay, and the switch tube cannot be protected in time.

Summary of the invention

The present application aims to solve at least one of the technical problems in the related art to some extent. To this end, a first object of the present application is to propose a protection device for a motor controller. The device can realize the three-phase short-circuit protection of the switch tube in the three-phase inverter bridge from the hardware, and the protection is timely, thereby reducing the risk that the software response is not timely caused damage to the switch tube, and improving the safety and reliability of the electric vehicle.

A second object of the present application is to propose a motor controller.

A third object of the present application is to propose an electric vehicle.

In order to achieve the above object, the first aspect of the present application provides a protection device for a motor controller, the motor controller includes a three-phase inverter bridge and a control chip, and the control chip is used to collect three motor a phase current and a DC bus voltage, the protection device comprising: a current comparison circuit, the current comparison circuit being connected to the control chip, the current comparison circuit for using a three-phase current of the motor and a preset current threshold Comparing, and outputting a first comparison signal when the three-phase current of the motor is greater than a preset current threshold; the voltage comparison circuit, the voltage comparison circuit is connected to the control chip, and the voltage comparison circuit is used for Comparing the DC bus voltage with a preset voltage threshold, and outputting a second comparison signal when the DC bus voltage is greater than a preset voltage threshold; a channel selection chip, the channel selection chip and the current comparison circuit, respectively The voltage comparison circuit, the control chip and the three-phase inverter bridge are connected, and the channel selection chip is configured to receive the control The chip outputs six PWM signals, and gates the six PWM signals according to at least one of the first comparison signal and the second comparison signal to perform three-phase short-circuit protection on the three-phase inverter bridge.

The protection device for the motor controller of the embodiment of the present application determines whether the three-phase current of the motor has an overcurrent through the current comparison circuit, and determines whether the DC bus voltage is overvoltaged by the voltage comparison circuit, and overcurrent or overvoltage occurs. And outputting at least one of the corresponding first comparison signal and the second comparison signal respectively, and then strobing the six PWM signals output by the control chip according to at least one of the first comparison signal and the second comparison signal by the channel selection chip The three-phase short-circuit protection is applied to the motor controller, thereby enabling three-phase short-circuit protection of the switch tube in the three-phase inverter bridge in time, thereby reducing the risk of the switch being damaged due to the software response being untimely, and improving the electric vehicle. Safety and reliability.

In addition, the protection device for the motor controller of the above embodiment of the present application may further have the following additional technical features:

According to an embodiment of the present application, the control chip is further configured to collect the rotation speed of the motor, and output an enable signal to the channel through the first inverter when the rotation speed of the motor is greater than or equal to the preset rotation speed. The chip is selected to cause the channel selection chip to perform the gating operation.

According to an embodiment of the present application, the protection device further includes a NAND gate circuit, and a first input end of the NAND circuit is connected to an output end of the current comparison circuit, and the NAND gate circuit a second input terminal is connected to an output end of the voltage comparison circuit, an output end of the NAND circuit is connected to the channel selection chip, and the NAND gate circuit receives the first comparison signal and the Outputting a high level signal to the channel selection chip when at least one of the comparison signals, wherein the channel selection chip strobes the output three-way bridge PWM signal to the three-phase inverter bridge according to the high level signal a three-phase upper bridge switch tube for controlling all three-phase upper bridge switch tubes to be turned on; or the channel selection chip strobing and outputting three three-way bridge PWM signals according to the high level signal to the three-phase inverse The three-phase lower bridge switch tube of the bridge is controlled to control all the three-phase lower bridge switch tubes to be turned on.

According to an embodiment of the present application, the NAND gate circuit includes a first AND gate and a second inverter.

According to an embodiment of the present application, the control chip is further configured to detect whether an error of an error occurs in a three-phase upper bridge or a three-phase lower bridge of the three-phase inverter bridge, wherein when the three-phase upper bridge fails The control chip outputs a three-phase upper bridge error signal to the channel selection chip, so that the channel selection chip strobe outputs a three-way down bridge PWM signal to the three-phase lower bridge switch tube of the three-phase inverter bridge; When the three-phase lower bridge fails, the control chip outputs a three-phase lower bridge error signal to the channel selection chip, so that the channel selects the chip strobe output three-way bridge PWM signal to the three-phase inverter The three-phase upper bridge switch of the bridge.

According to an embodiment of the present application, the current comparison circuit includes: a first resistor, one end of the first resistor is connected to a positive pole of the first DC power source; and a second resistor, one end of the second resistor is The other end of the first resistor is connected to form a first node, and the other end of the second resistor is connected to a negative pole of the first DC power source; a first comparator, a positive input terminal of the first comparator The first node is connected; a third resistor, one end of the third resistor is an input end of the three-phase current of the motor, and the other end of the third resistor is connected to a negative input end of the first comparator a fourth resistor, one end of the fourth resistor is connected to the other end of the third resistor, and the other end of the fourth resistor is connected to an output end of the first comparator; a fifth resistor, the first One end of the fifth resistor is connected to the anode of the second DC power source; the sixth resistor has one end connected to the other end of the fifth resistor and forms a second node, and the other end of the sixth resistor is The cathode of the second DC power source a seventh resistor, one end of the seventh resistor is connected to the second node; and a second comparator, a negative input end of the second comparator is used as an input end of a three-phase current of the motor, a positive input end of the second comparator is connected to the other end of the seventh resistor, and an output end of the second comparator is connected to an output end of the first comparator for outputting the first comparison signal An eighth resistor, one end of the eighth resistor is connected to the other end of the seventh resistor, and the other end of the eighth resistor is connected to an output end of the second comparator; a ninth resistor, the first One end of the nine resistor is connected to one end of the first resistor, and the other end of the ninth resistor is connected to the output end of the first comparator.

According to an embodiment of the present application, the voltage comparison circuit includes: a tenth resistor, one end of the tenth resistor is connected to a positive pole of a third direct current power source; and an eleventh resistor, one end of the eleventh resistor The tenth resistor is connected and forms a third node, the other end of the eleventh resistor is connected to the negative pole of the third DC power source; the third comparator, the negative output of the third comparator is a third node is connected, a positive input end of the third comparator serves as an input end of the DC bus voltage, and an output end of the third comparator outputs the second comparison signal; a twelfth resistor, the first One end of the twelve resistor is connected to the third node, and the other end of the twelfth resistor is connected to the output end of the third comparator; a thirteenth resistor, one end of the thirteenth resistor is One end of the tenth resistor is connected, and the other end of the thirteenth resistor is connected to the output of the third comparator.

According to an embodiment of the present application, the first comparator, the second comparator, and the third comparator all adopt a ULM2901 chip.

In order to achieve the above object, a second aspect of the present application proposes a motor controller including the above-described protection device for a motor controller.

The motor controller of the embodiment of the present application adopts the above-mentioned protection device for the motor controller, and can perform three-phase short-circuit protection on the switch tube of the three-phase inverter bridge in time, thereby reducing the risk of the switch tube being damaged due to the software response being not timely. Improve the safety and reliability of electric vehicles.

In order to achieve the above object, an embodiment of the third aspect of the present application proposes an electric vehicle including the above-described motor controller.

The electric vehicle of the embodiment of the present invention adopts the motor controller of the above embodiment, and can perform three-phase short-circuit protection on the switch tube in the three-phase inverter bridge in time, thereby reducing the risk that the software response is not timely and causing damage of the switch tube, and improves the risk. The safety and reliability of electric vehicles themselves.

DRAWINGS

The above and other aspects and advantages of the present invention will become apparent and readily understood from

1 is a circuit diagram of a motor control circuit according to an embodiment of the present application;

2 is a structural block diagram of a protection device for a motor controller according to an embodiment of the present application;

3 is a topological view of a protection device for a motor controller in accordance with an embodiment of the present application;

4 is a topological view of a current comparison circuit in accordance with an example of the present application;

5 is a topological diagram of a voltage comparison circuit in accordance with an example of the present application;

6 is a flow chart showing the operation of a protection device for a motor controller in accordance with an embodiment of the present application;

7 is a structural block diagram of a motor controller according to an embodiment of the present application;

FIG. 8 is a structural block diagram of an electric vehicle according to an embodiment of the present application.

Detailed ways

The embodiments of the present application are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative, and are not to be construed as limiting.

A protection device, a motor controller, and an electric vehicle for a motor controller of an embodiment of the present application will be described below with reference to the drawings.

2 is a structural block diagram of a protection device for a motor controller in accordance with one embodiment of the present application.

In the embodiment of the present application, as shown in FIG. 1, the motor controller 1000 includes a three-phase inverter bridge 10 and a control chip 20, wherein the control chip 20 is used to collect the three-phase current and the DC bus voltage of the motor.

As shown in FIG. 2, the protection device 100 of the motor controller includes a current comparison circuit 30, a voltage comparison circuit 40, and a channel selection chip 50.

The current comparison circuit 30 is connected to the control chip 20, and the current comparison circuit 30 is configured to compare the three-phase current of the motor with a preset current threshold, and output the first when the three-phase current of the motor is greater than a preset current threshold. Compare signals. The voltage comparison circuit 40 is connected to the control chip 20, and the voltage comparison circuit 40 is configured to compare the DC bus voltage with a preset voltage threshold and output a second comparison signal when the DC bus voltage is greater than a preset voltage threshold. The channel selection chip 50 is respectively connected to the current comparison circuit 30, the voltage comparison circuit 40, the control chip 20 and the three-phase inverter bridge 10. The channel selection chip 50 is configured to receive the six PWM signals output by the control chip 20, and according to the first comparison signal. And strobing the six PWM signals with at least one of the second comparison signals to perform three-phase short circuit protection on the three-phase inverter bridge 10.

In this embodiment, the current threshold preset with the three-phase current of the motor and the voltage threshold preset with the DC bus voltage can be set according to a specific motor controller and needs.

Specifically, the current comparison circuit 30 outputs a first comparison signal when the three-phase current of the motor is greater than a preset current threshold, and the voltage comparison circuit 40 outputs a second comparison signal when the DC bus voltage is greater than a preset voltage threshold, and the channel selection chip The receiving circuit 20 receives the six PWM signals outputted by the control chip 20, and the channel selecting chip 50 can generate an overcurrent according to at least one of the first comparison signal and the second comparison signal, that is, when the three-phase current of the motor occurs or the DC bus voltage is overvoltaged. The six-way PWM signal is gated to perform three-phase short-circuit protection on the three-phase inverter bridge 10. That is to say, the channel selection chip 50 can perform gating on the three-phase inverter bridge 10 according to at least one of the first comparison signal and the second comparison signal to perform three-phase short-circuit protection.

Therefore, the protection device can perform three-phase short-circuit protection on the switch tube in the three-phase inverter bridge in time, thereby reducing the risk of the switch tube being damaged due to the software failure, and improving the safety and reliability of the electric vehicle.

In an embodiment of the present application, as shown in FIG. 3, the control chip 20 is further configured to collect the rotation speed of the motor, and output an enable signal through the first inverter D1 when the rotation speed of the motor is greater than or equal to the preset rotation speed. To the channel selection chip 50, the channel selection chip 50 is strobed. Thereby, the switching tube in the three-phase inverter bridge can be effectively protected when the motor is running at high speed, thereby reducing the risk of damage.

In a specific embodiment of the present application, as shown in FIG. 3, the protection device 100 further includes a NAND circuit 60. The first input terminal of the NAND circuit 60 is connected to the output of the current comparison circuit 30. The second input of the circuit 60 is connected to the output of the voltage comparison circuit 40, the output of the NAND circuit 60 is connected to the channel selection chip 50, and the NAND circuit 60 receives the first comparison signal and the second comparison signal. At least one of the outputs outputs a high level signal to the channel selection chip 50. That is, the NAND circuit 60 outputs a high level signal to the channel selection chip 50 when receiving at least one of the first comparison signal and the second comparison signal.

The channel selection chip 50 strobes and outputs the three-way bridge PWM signal to the three-phase upper bridge switch tube of the three-phase inverter bridge 10 (ie, IGBT2, IGBT4, and IGBT6 in FIG. 1) according to the high level signal to control the three-phase. The upper switch tube is all turned on; or the channel selection chip 50 strobes and outputs the three-way lower bridge PWM signal according to the high level signal to the three-phase lower bridge switch tube of the three-phase inverter bridge 10 (ie, IGBT1, IGBT3 in FIG. 1) And IGBT5) to control all three-phase lower bridge switch tubes to conduct.

Referring to FIG. 3, the NAND circuit 60 includes a first AND gate A and a second inverter D2. The AND gate A and the second inverter D2 are connected in series. Specifically, the second comparison signal is connected to the input terminal of the gate A. And the first comparison signal, the output of the AND gate A is connected to one end of the second inverter D2, and the other end of the second inverter D2 is connected to the IN2 pin of the channel selection chip 50.

In the embodiment of the present application, referring to FIG. 3, the control chip 20 is further configured to detect whether an error of an error occurs in the three-phase upper bridge or the three-phase lower bridge of the three-phase inverter bridge 10. When the three-phase upper bridge fails, the control chip 20 outputs a three-phase upper bridge error signal to the channel selection chip 50, so that the channel selection chip 50 strobes and outputs the three-way lower bridge PWM signal to the three-phase inverter bridge 10 When the three-phase lower bridge fails, the control chip 20 outputs a three-phase lower bridge error signal to the channel selection chip 50, so that the channel selection chip strobe outputs the three-way bridge PWM signal to the three-phase inverter bridge 10 Three-phase upper bridge switch tube.

In an example of the present application, as shown in FIG. 4, the current comparison circuit 30 includes a first resistor R1, a second resistor R2, a first comparator C1, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The sixth resistor R6, the seventh resistor R7, the second comparator C2, the eighth resistor R8, and the ninth resistor R9.

The one end of the first resistor R1 is connected to the anode of the first DC power source DC1. One end of the second resistor R2 is connected to the other end of the first resistor R1, and forms a first node a, and the other end of the second resistor R2 is connected to the cathode of the first DC power source DC1. The positive input of the first comparator C1 is connected to the first node a. One end of the third resistor R3 serves as an input terminal of the three-phase current of the motor, and the other end of the third resistor R3 is connected to the negative input terminal of the first comparator C1. One end of the fourth resistor R4 is connected to the other end of the third resistor R3, and the other end of the fourth resistor R4 is connected to the output end of the first comparator C1. One end of the fifth resistor R5 is connected to the anode of the second DC power source DC2. One end of the sixth resistor R6 is connected to the other end of the fifth resistor R5, and a second node b is formed, and the other end of the sixth resistor R6 is connected to the cathode of the second DC power source DC2. One end of the seventh resistor R7 is connected to the second node b. The negative input end of the second comparator C2 serves as the input end of the three-phase current of the motor, the negative input end of the second comparator C2 is connected to the other end of the seventh resistor R7, and the output end of the second comparator C2 is first The output of the comparator C1 is connected to output a first comparison signal. One end of the eighth resistor R8 is connected to the other end of the seventh resistor R7, and the other end of the eighth resistor R8 is connected to the output end of the second comparator C2. One end of the ninth resistor R9 is connected to one end of the first resistor R1, and the other end of the ninth resistor R9 is connected to the output end of the first comparator C1.

It should be noted that the three-phase current is alternating current, and when it is overcurrent, it may be a positive overcurrent or a reverse overcurrent. Therefore, in order to improve the accuracy of the judgment, two comparators may be provided (first The comparator C1 and the second comparator C2) determine whether the three-phase current of the motor is greater than a preset current threshold.

Further, as shown in FIG. 5, the voltage comparison circuit 40 includes a tenth resistor R10, an eleventh resistor R11, a third comparator C3, a twelfth resistor R12, and a thirteenth resistor R13.

The one end of the tenth resistor R10 is connected to the anode of the third DC power source DC3. One end of the eleventh resistor R11 is connected to the tenth resistor R10, and forms a third node c, and the other end of the eleventh resistor R11 is connected to the cathode of the third DC power source DC3. The negative output of the third comparator C3 is connected to the third node c, the positive input of the third comparator C3 serves as the input of the DC bus voltage, and the output of the third comparator C3 is used to output the second comparison signal. One end of the twelfth resistor R12 is connected to the third node c, and the other end of the twelfth resistor R12 is connected to the output terminal of the third comparator C3. One end of the thirteenth resistor R13 is connected to one end of the tenth resistor R10, and the other end of the thirteenth resistor R13 is connected to the output end of the third comparator C3.

Optionally, the first comparator C1, the second comparator C2, and the third comparator C3 may each select a ULM2901 chip.

It should be noted that the values of the voltages of the first DC power source DC1, the second DC power source DC2, and the third DC power source DC3, and the resistance values of the first to thirteenth resistors R1, R13, are known to those skilled in the art. , can be set according to the specific motor control circuit, not specifically limited here.

In addition, the current comparison circuit 30 and the voltage comparison circuit 40 are not limited to the topology shown in FIGS. 4 and 5, and may each be set according to any of the differential comparison circuits.

The working principle of the protection device for the motor controller of one embodiment of the present application will be described below in conjunction with FIGS. 3-6 for ease of understanding.

Specifically, referring to FIG. 3 and FIG. 4, the control chip 20 inputs the three-phase current of the collected motor to the current comparison circuit 30, and when the three-phase current of the motor is greater than the comparison threshold set by the current comparison circuit 30, it is considered to occur. The overcurrent, the current comparison circuit 30 outputs a first comparison signal, the first comparison signal is at a low level, otherwise the third comparison signal is output, and the third comparison signal is at a high level.

Referring to FIG. 3 and FIG. 5, the control chip 20 inputs the collected DC bus voltage to the voltage comparison circuit 40. When the DC bus voltage is greater than the comparison threshold set by the voltage comparison circuit, it is considered that an overvoltage occurs, and the voltage comparison circuit 40 outputs. The second comparison signal, the second comparison signal is low level, otherwise the fourth comparison signal is output, and the fourth comparison signal is high level.

Referring to FIG. 3, the control chip 20 compares the speed of the collected motor with a preset speed. When the speed of the collected motor is greater than or equal to the preset speed, the enable signal output through the first inverter D1 is low. .

Further, referring to FIG. 3, the first comparison signal and the second comparison signal are input to the NAND circuit 60, and the preset NAND signals are output to the IN1 and IN2 pins of the channel selection chip 50. The enable signal is input to the /EN pin of the channel selection chip 50. The lower bridge error signal /FLTB is outputted to FLTB after the third inverter D3, and the lower bridge error signal /FLTB is input to the NO1/NO3/NO5 pin (lower bridge PWM) of the channel selection chip 50, and the FLTB is input to the channel selection chip. The NO2/NO4/NO6 pin of 50 (upper bridge PWM) inputs six PWM waves from the control chip 20 to the NC1 to NC6 pins of the channel selection chip 50.

Referring to FIG. 3 and FIG. 6, when overcurrent or overvoltage occurs, at least one of the current comparison circuit 30 and the voltage comparison circuit 40 outputs a low level, and the preset NAND signal is output after the NAND gate circuit 60 is high. The level is input to the IN1/IN2 pin of the channel selection chip 50. If the rotation speed of the motor is greater than the preset rotation speed at this time, the enable signal outputted through the first inverter D1 is at a low level, and is input to the /EN enable pin of the channel selection chip 50. Furthermore, the channel selection chip 50 can gate the NO1/NO2/NO3/NO4/NO5/NO6 channels, and the upper bridge (NO2/NO4/NO6) preset outputs COM2/COM4/COM6, and the lower bridge (NO1/NO3/NO5) The default output is COM1/COM3/COM5.

If the PWM output of the upper bridge is FLTB, the PWM output of the lower bridge is /FLTB, then when the lower bridge reports an error, /FLTB is low, and the output of the three-way lower bridge PWM wave is low, three-phase inverter bridge The three-phase lower bridge of 10 is closed, FLTB is high level, the PWM wave output of the three-way bridge is high level, and the three-phase upper bridge of the three-phase inverter bridge 10 is short-circuited; when the lower bridge is not reported, /FLTB is high Ping, three-way lower bridge PWM wave output is high level, three-phase inverter bridge 10 three-phase lower bridge open short circuit, FLTB is low level, three-way bridge PWM wave output is low level, three-phase inverter bridge The three-phase upper bridge of 10 is closed. Thereby, the switch tube in the three-phase inverter bridge can be protected in time, the risk of the switch tube being damaged due to the software response is not reduced, and the safety and reliability of the electric vehicle are improved.

In summary, the protection device for the motor controller according to an embodiment of the present application uses electronic components to construct a hardware circuit such as a current comparison circuit and a voltage comparison circuit, thereby selecting a chip according to a current through a channel when an overcurrent or an overvoltage occurs. The corresponding comparison signal outputted by the comparison circuit and the voltage comparison circuit strobes the six PWM signals output by the control chip to perform three-phase short-circuit protection on the motor controller, thereby realizing the three-phase inverter bridge switch from the hardware. The three-phase short-circuit protection of the tube reduces the delay and can protect the switch tube in the three-phase inverter bridge in time, which reduces the risk of the switch being damaged due to the software response, and improves the safety and reliability of the electric vehicle.

FIG. 7 is a block diagram showing the structure of a motor controller according to an embodiment of the present application. As shown in FIG. 7, the motor controller 1000 includes the protection device 100 for the motor controller of the above embodiment.

In this embodiment, the motor controller 1000 further includes a three-phase inverter bridge 10 and a control chip 20.

The motor controller of one embodiment of the present application implements the three-phase short-circuit protection of the switch tube in the three-phase inverter bridge from the hardware by using the above-mentioned protection device for the motor controller, which can reduce the delay and protect the three-phase inverse in time. The switch tube in the variable bridge reduces the risk of damage to the switch tube caused by the software response, and improves the safety and reliability of the electric vehicle.

Further, the present application proposes an electric vehicle.

Fig. 8 is a block diagram showing the structure of an electric vehicle according to an embodiment of the present application. As shown in FIG. 8, the electric vehicle 2000 includes the motor controller 1000 of the above embodiment.

The electric vehicle of the embodiment of the present application adopts the motor controller of the above embodiment to realize the three-phase short-circuit protection of the switch tube in the three-phase inverter bridge from the hardware, which can reduce the delay and protect the three-phase inverter bridge in time. The switch tube reduces the risk of damage to the switch tube caused by the software response, and improves the safety and reliability of the electric vehicle itself.

In addition, other configurations and functions of the electric vehicle according to an embodiment of the present application are known to those skilled in the art, and are not described herein in order to reduce redundancy.

In the description of the present application, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " After, "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship of the indications of "radial", "circumferential", etc., is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description of the present application and simplified description, and does not indicate or imply the indicated device or component. It must be constructed and operated in a particular orientation, and is therefore not to be construed as limiting.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, the terms "installation", "connected", "connected", "fixed" and the like shall be understood broadly, and may be either a fixed connection or a detachable connection, unless otherwise explicitly stated and defined. , or integrated; can be mechanical or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction of two elements, unless otherwise specified Limited. For those skilled in the art, the specific meanings of the above terms in the present application can be understood on a case-by-case basis.

In the present application, the first feature "on" or "below" the second feature may be the direct contact of the first and second features, or the first and second features are indirectly through the intermediate medium, unless otherwise explicitly stated and defined. contact. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or above the second feature, or merely that the first feature level is higher than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely that the first feature level is less than the second feature.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the application. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification and features of various embodiments or examples may be combined and combined without departing from the scope of the invention.

While the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the present application. The embodiments are subject to variations, modifications, substitutions and variations.

Claims

A protection device for a motor controller, characterized in that the motor controller comprises a three-phase inverter bridge and a control chip, the control chip is for collecting three-phase current and DC bus voltage of the motor, the protection The device includes:

a current comparison circuit, the current comparison circuit is connected to the control chip, the current comparison circuit is configured to compare a three-phase current of the motor with a preset current threshold, and the three-phase current of the motor is greater than Outputting the first comparison signal when the preset current threshold is used;

a voltage comparison circuit, the voltage comparison circuit is connected to the control chip, the voltage comparison circuit is configured to compare the DC bus voltage with a preset voltage threshold, and the DC bus voltage is greater than a preset voltage Outputting a second comparison signal when the threshold is;

a channel selection chip, wherein the channel selection chip is respectively connected to the current comparison circuit, the voltage comparison circuit, the control chip and the three-phase inverter bridge, and the channel selection chip is configured to receive the output of the control chip And a six-way PWM signal, and strobing the six PWM signals according to at least one of the first comparison signal and the second comparison signal to perform three-phase short-circuit protection on the three-phase inverter bridge.
The protection device for a motor controller according to claim 1, wherein the control chip is further configured to collect a rotation speed of the motor, and pass the first when the rotation speed of the motor is greater than or equal to a preset rotation speed. An inverter outputs an enable signal to the channel selection chip to cause the channel selection chip to perform a gating operation.
A protection device for a motor controller according to claim 1 or 2, further comprising a NAND circuit, wherein a first input terminal of said NAND circuit is connected to an output of said current comparison circuit a second input end of the NAND circuit is connected to an output end of the voltage comparison circuit, an output end of the NAND circuit is connected to the channel selection chip, and the NAND circuit receives the Outputting a high level signal to the channel selection chip when at least one of the first comparison signal and the second comparison signal is described, wherein

The channel selection chip strobes and outputs a three-way bridge PWM signal to the three-phase upper bridge switch tube of the three-phase inverter bridge according to the high level signal, so as to control all three-phase upper bridge switch tubes to be turned on; or

The channel selection chip strobes and outputs a three-way down bridge PWM signal to the three-phase lower bridge switch tube of the three-phase inverter bridge according to the high level signal, so as to control all three-phase lower bridge switch tubes to be turned on. .
A protection device for a motor controller according to claim 3, wherein said NAND circuit includes a first AND gate and a second inverter, said AND gate and said second inverter Connect in series.
The protection device for a motor controller according to claim 3 or 4, wherein the control chip is further configured to detect whether an error occurs in the three-phase upper bridge or the three-phase lower bridge of the three-phase inverter bridge. Failure, among them,

When the three-phase upper bridge fails, the control chip outputs a three-phase upper bridge error signal to the channel selection chip, so that the channel selection chip strobe outputs three downlink PWM signals to the three-phase inverse Three-phase lower bridge switch tube of the bridge;

When the three-phase lower bridge fails, the control chip outputs a three-phase lower bridge error signal to the channel selection chip, so that the channel selects the chip strobe output three-way bridge PWM signal to the three-phase inverter The three-phase upper bridge switch of the bridge.
A protection device for a motor controller according to any one of claims 1 to 5, wherein the current comparison circuit comprises:

a first resistor, one end of the first resistor is connected to a positive pole of the first DC power source;

a second resistor, one end of the second resistor is connected to the other end of the first resistor, and forms a first node, and the other end of the second resistor is connected to a cathode of the first DC power source;

a first comparator, a positive input end of the first comparator is connected to the first node;

a third resistor, one end of the third resistor is an input end of a three-phase current of the motor, and the other end of the third resistor is connected to a negative input end of the first comparator;

a fourth resistor, one end of the fourth resistor is connected to the other end of the third resistor, and the other end of the fourth resistor is connected to an output end of the first comparator;

a fifth resistor, one end of the fifth resistor is connected to the anode of the second DC power source;

a sixth resistor, one end of the sixth resistor is connected to the other end of the fifth resistor, and forms a second node, and the other end of the sixth resistor is connected to a cathode of the second DC power source;

a seventh resistor, one end of the seventh resistor is connected to the second node;

a second comparator, the negative input end of the second comparator serves as an input end of the three-phase current of the motor, and the positive input end of the second comparator is connected to the other end of the seventh resistor An output end of the second comparator is connected to an output end of the first comparator for outputting the first comparison signal;

An eighth resistor, one end of the eighth resistor is connected to the other end of the seventh resistor, and the other end of the eighth resistor is connected to an output end of the second comparator;

And a ninth resistor, one end of the ninth resistor is connected to one end of the first resistor, and the other end of the ninth resistor is connected to an output end of the first comparator.
The protection device for a motor controller according to any one of claims 1 to 6, wherein the voltage comparison circuit comprises:

a tenth resistor, one end of the tenth resistor is connected to the anode of the third DC power source;

An eleventh resistor, one end of the eleventh resistor is connected to the tenth resistor, and forms a third node, and the other end of the eleventh resistor is connected to a cathode of the third DC power source;

a third comparator, a negative output of the third comparator is connected to the third node, a positive input of the third comparator serves as an input of the DC bus voltage, and a third comparator The output terminal outputs the second comparison signal;

a twelfth resistor, one end of the twelfth resistor is connected to the third node, and the other end of the twelfth resistor is connected to an output end of the third comparator;

And a thirteenth resistor, one end of the thirteenth resistor is connected to one end of the tenth resistor, and the other end of the thirteenth resistor is connected to an output end of the third comparator.
The protection device for a motor controller according to claim 6 or 7, wherein the first comparator, the second comparator, and the third comparator each employ a ULM2901 chip.
A motor controller, comprising: a protection device for a motor controller according to any one of claims 1-8, the motor controller comprising a three-phase inverter bridge and a control chip, A three-phase inverter bridge is connected to the protection device, and the control chip is connected to the protection device.
An electric vehicle characterized by comprising the motor controller of claim 9.