Motor controller, power assembly and electric vehicle

Abstract

The utility model provides a motor controller, a power assembly and an electric vehicle, which are applied to the technical field of new energy automobiles, and the motor controller comprises a three-phase switch tube bridge arm, a bridge arm driving circuit and a voltage detection circuit. Each phase of switching tube bridge arm comprises an upper bridge arm switching tube and a lower bridge arm switching tube, the two ends of each phase of switching tube bridge arm are used for receiving power supplied by a power battery, and the middle point of each phase of switching tube bridge arm is used for outputting a phase of alternating current to drive a driving motor of a vehicle. The voltage detection circuit can output a group of voltage detection signals in the process that one of an upper bridge arm switch tube and a lower bridge arm switch tube of a one-phase switch tube bridge arm is switched on and the other one is switched off. The bridge arm driving circuit can drive the bridge arm midpoint of the three-phase switch tube bridge arm to output three-phase alternating current according to a comparison result of a group of reference voltage values and the group of voltage detection signals. On the basis, a plurality of switch tubes can be detected through a single detection circuit.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicles, and in particular to a motor controller, a powertrain, and an electric vehicle. Background Art

[0002] The motor control unit (MCU) is a component used to control the motor in new energy vehicles. It is also connected to the power battery and converts the DC power provided by the battery into the AC power required to drive the motor. The MCU typically features an inverter circuit with a three-phase full-bridge topology. This conversion is achieved by controlling the on / off switching transistors in each phase of the inverter circuit. The switching transistors in the inverter circuit primarily use semiconductor switching transistors such as insulated gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs). However, problems such as overvoltage, overcurrent, overtemperature, and defects introduced by the device manufacturing process can cause semiconductor switching transistors to short circuit, open circuit, abnormal leakage between the emitter C and collector E of the IGBT, or abnormal leakage between the source S and drain D of the MOSFET. Therefore, it is necessary to monitor the status of the switching transistors in the inverter circuit to ensure safe and reliable vehicle operation and avoid accidents. However, current switch tube detection circuits can usually only detect a single switch tube, and the detection circuit structure is complex and the cost is too high. Therefore, it is urgent to provide a solution to solve the above problems. Utility Model Content

[0003] Embodiments of the present application provide a motor controller, a powertrain, and an electric vehicle to achieve cost reduction while detecting switching tubes in an inverter circuit within a motor controller.

[0004] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions.

[0005] In a first aspect, a motor controller is provided, comprising a three-phase switching tube bridge arm, a bridge arm drive circuit, and a voltage detection circuit. Each phase switching tube bridge arm comprises an upper bridge arm switching tube and a lower bridge arm switching tube. The ends of each phase switching tube bridge arm are used to receive power from the vehicle's power battery. The midpoint of each phase switching tube bridge arm is used to output a single-phase alternating current (AC) to drive the vehicle's drive motor. An upper bridge arm switching tube and a lower bridge arm switching tube of each phase switching tube bridge arm are used to be turned on and off, respectively, based on a drive signal output by the bridge arm drive circuit. The voltage detection circuit is capable of outputting a set of voltage detection signals when one of an upper bridge arm switching tube and a lower bridge arm switching tube of a phase switching tube bridge arm is turned on and the other is turned off. The bridge arm drive circuit is capable of driving the midpoints of the three-phase switching tube bridge arms to output three-phase AC power based on a comparison result between a set of reference voltage values and the set of voltage detection signals.

[0006] When both an upper-arm switch and a lower-arm switch in each phase of a three-phase switching arm are normal, during the process in which one of the upper-arm switch and the lower-arm switch in one phase of the switching arm is turned on and the other is turned off, the set of voltage detection signals output by the voltage detection circuit should be the same as a set of preset reference voltage values. If the turned-on switch has an open-circuit fault, the output voltage at the midpoint of the bridge arm of that phase of the switching arm will change, and the set of reference voltage values will differ from the set of voltage detection signals. Therefore, during the process in which one of the upper-arm switch and the lower-arm switch in one phase of the switching arm is turned on and the other is turned off, the comparison result between the set of reference voltage values and the set of voltage detection signals can be used to detect whether the bridge arm of that phase of the switching arm has an open-circuit fault. If the upper-arm switch and the lower-arm switch in that phase of the switching arm do not have an open-circuit fault, the bridge arm drive circuit can drive the midpoint of the three-phase switching arm of the switching arm to output three-phase AC power. Based on this, it is possible to avoid providing an independent detection circuit for each switch tube, thereby reducing the cost of detecting the bridge arm of the switch tube.

[0007] In one implementation, the above-mentioned set of voltage detection signals includes a first voltage detection signal, and the above-mentioned voltage detection circuit is used to output the first voltage detection signal when an upper arm switch tube of a phase switch tube bridge arm is turned on and a lower arm switch tube is turned off.

[0008] Through the above method, it is possible to detect whether an upper-arm switching tube of a single-phase switching tube bridge arm has an open-circuit fault based on the first voltage detection signal and the corresponding reference voltage value. If the first voltage detection signal is the same as the corresponding reference voltage value in the set of reference voltage values, then the upper-arm switching tube of the single-phase switching tube bridge arm does not have an open-circuit fault, and the detection of whether the lower-arm switching tube has an open-circuit fault can continue. If the first voltage detection signal is different from the corresponding reference voltage value in the set of reference voltage values, then the upper-arm switching tube of the single-phase switching tube bridge arm has an open-circuit fault.

[0009] In one implementation, the above-mentioned set of voltage detection signals includes a second voltage detection signal, and the above-mentioned voltage detection circuit is used to output the second voltage detection signal when an upper arm switch tube of a phase switch tube bridge arm is turned off and a lower arm switch tube is turned on.

[0010] Through the above method, it is possible to detect whether an open-circuit fault exists in the lower-arm switching tube of a single-phase switching tube bridge arm based on the second voltage detection signal and the corresponding reference voltage value. If the second voltage detection signal is the same as the corresponding reference voltage value in the set of reference voltage values, then the lower-arm switching tube of the single-phase switching tube bridge arm does not have an open-circuit fault. If the second voltage detection signal is different from the corresponding reference voltage value in the set of reference voltage values, then the lower-arm switching tube of the single-phase switching tube bridge arm does have an open-circuit fault. In this case, a corresponding fault alarm signal can be output.

[0011] In one implementation, the voltage detection circuit includes a first resistor and a second resistor. One end of the first resistor is connected to the midpoint of a bridge arm of a single-phase switching tube, and the other end of the first resistor is connected to one end of the second resistor. The other end of the second resistor is connected to the negative terminal of the power battery. The series connection point of the first and second resistors is used to output a set of voltage detection signals. The output voltage output from the midpoint of the bridge arm of the single-phase switching tube can be divided by the first and second resistors, and a set of voltage detection signals is output through the series connection point of the first and second resistors, thereby achieving voltage detection of an upper bridge arm switching tube and a lower bridge arm switching tube of a single-phase switching tube bridge arm.

[0012] In one implementation, the above-mentioned voltage detection circuit is also used to output another set of voltage detection signals when an upper arm switch tube of a phase switch tube bridge arm is turned off and a lower arm switch tube is turned off, and the above-mentioned bridge arm drive circuit is used to drive the bridge arm midpoint of the three-phase switch tube bridge arm to output three-phase alternating current based on the comparison results of a set of reference voltage values and the above-mentioned set of voltage detection signals, and the comparison results of another set of reference voltage values and the other set of voltage detection signals.

[0013] During the process of turning off an upper-arm switch tube and a lower-arm switch tube in a single-phase switching tube bridge arm, a short-circuit fault can be detected between the upper-arm switch tube and the lower-arm switch tube in the single-phase switching tube bridge arm based on the comparison results of another set of voltage detection signals and another set of reference voltage values. During the process of turning on an upper-arm switch tube and a lower-arm switch tube in a single-phase switching tube bridge arm and turning off the other, an open-circuit fault can be detected between the upper-arm switch tube and the lower-arm switch tube in the single-phase switching tube bridge arm based on the comparison results of the above set of reference voltage values and the above set of voltage detection signals. Therefore, to ensure safer and more reliable operation of the three-phase switching tube bridge arm, the midpoint of the three-phase switching tube bridge arm can be driven to output three-phase AC power only when both an upper-arm switch tube and a lower-arm switch tube in each phase switching tube bridge arm are free of short-circuit faults and open-circuit faults.

[0014] In one implementation, the voltage detection circuit further includes a third resistor, one end of which is connected in series with one end of the first resistor, and the other end of which is connected to the positive terminal of a phase switching tube bridge arm. The series connection point of the first and second resistors is further configured to output another set of voltage detection signals. The voltage division by the first, second, and third resistors enables detection of open-circuit faults and short-circuit faults in an upper-arm switching tube and a lower-arm switching tube of a phase switching tube bridge arm.

[0015] In one implementation, the one bridge arm drive circuit is configured to drive the midpoint of the three-phase switching tube bridge arm to output three-phase AC power when the other set of reference voltage values is identical to the other set of voltage detection signals and the one set of reference voltage values is identical to the one set of voltage detection signals. This method allows the midpoint of the three-phase switching tube bridge arm to be driven to output three-phase AC power when both an upper-arm switching tube and a lower-arm switching tube of each phase switching tube bridge arm in the three-phase switching tube bridge arm are free of short-circuit faults and open-circuit faults.

[0016] In one implementation, the bridge arm drive circuit is further configured to control one of an upper-arm switch tube and a lower-arm switch tube of a phase switch tube bridge arm to be turned on and the other to be turned off, when another set of reference voltage values of the phase switch tube bridge arm is identical to another set of voltage detection signals. When the three-phase switch tube bridge arm is first powered on, both an upper-arm switch tube and a lower-arm switch tube of each phase switch tube bridge arm are in the off state. Therefore, it is possible to first detect whether a short-circuit fault occurs during the process of turning off an upper-arm switch tube and a lower-arm switch tube of a phase switch tube bridge arm, and then detect whether an open-circuit fault occurs during the process of turning on and off an upper-arm switch tube and a lower-arm switch tube of a phase switch tube bridge arm, thereby reducing detection delay.

[0017] In one implementation, the bridge arm drive circuit is further configured to control the switching arms of the other two phases to remain off while controlling one of the upper and lower switching arms of a switching arm of a phase to turn on and the other to turn off. This prevents the switching arms of the other two phases from interfering with the detection results.

[0018] In one implementation, the voltage detection circuit further includes a first capacitor, a second capacitor, and a fourth resistor. One end of the first capacitor is connected to the series connection point, and the other end of the first capacitor is connected to the negative electrode of the power battery. One end of the fourth resistor is connected to the series connection point, and the other end of the fourth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the negative electrode of the power battery. The connection point between the fourth resistor and the second capacitor is used to output a filtered voltage detection signal. The first capacitor, the second capacitor, and the fourth resistor can form a π-type filter circuit, thereby making the filtered voltage detection signal more accurate.

[0019] In one implementation, the one bridge arm drive circuit is further configured to, when the set of reference voltage values is the same as the set of voltage detection signals, first turn off one upper-arm switch and one lower-arm switch of one phase's switching arm, and then control one of the upper-arm switch and one lower-arm switch of another phase's switching arm to turn on and the other to turn off. This ensures that during detection, only one of the upper-arm switch and one of the lower-arm switch of one phase's switching arm is turned on and the other is turned off, thereby increasing the accuracy of detection results.

[0020] In one implementation, the one bridge arm drive circuit is further configured to control the shutdown of one upper-arm switching tube and one lower-arm switching tube in each phase switching tube bridge arm when the set of reference voltage values differs from the set of voltage detection signals. When the set of reference voltage values differs from the set of voltage detection signals, this indicates an open-circuit fault in one of the upper-arm switching tubes or one of the lower-arm switching tubes in the switching tube bridge arm of the phase. Therefore, it is necessary to control the shutdown of one of the upper-arm switching tubes and one of the lower-arm switching tubes in each phase switching tube bridge arm to avoid safety accidents.

[0021] In one implementation, the motor controller further includes two other voltage detection circuits and a controller, the other two voltage detection circuits corresponding to the other two-phase switch arms, respectively. The one bridge arm drive circuit is further configured to control one upper-arm switch and one lower-arm switch in the other two-phase switch arms to remain off while one of the upper-arm switch and the lower-arm switch in the one-phase switch arm is on and the other is off. The controller is configured to compare a set of detection signals output by the voltage detection circuit corresponding to the one-phase switch arm with a set of reference voltage values while one of the upper-arm switch and the lower-arm switch in the one-phase switch arm is on and the other is off. Through the above approach, each phase switch arm can be detected by a corresponding voltage detection circuit, thereby more accurately locating the faulty switch.

[0022] In a second aspect, a powertrain is provided, comprising a drive motor and a motor controller according to any one of the implementations of the first aspect. The motor controller is configured to output three-phase current to control the drive motor.

[0023] In a third aspect, an electric vehicle is provided, comprising the powertrain of the second aspect and a power battery, wherein the power battery is used to power a motor controller in the powertrain.

[0024] Regarding the technical principles and beneficial effects of the second and third aspects mentioned above, please refer to the relevant description of the first aspect mentioned above, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the topological structure of an electric vehicle provided in an embodiment of the present application;

[0026] Figure 2 A schematic structural diagram of a powertrain provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 1 ;

[0028] Figure 4 A schematic diagram of a topological structure of a switch tube state detection circuit provided in an embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 2 ;

[0030] Figure 6 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 3 ;

[0031] Figure 7 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 4 ;

[0032] Figure 8 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 5 ;

[0033] Figure 9 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 6 ;

[0034] Figure 10 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application Figure 7 ;

[0035] Figure 11 A schematic diagram of a state in which both the upper switch tube and the lower switch tube are turned off according to an embodiment of the present application;

[0036] Figure 12 This is a schematic diagram of a state in which only the upper switch tube is turned on, provided in an embodiment of the present application;

[0037] Figure 13 This is a schematic diagram of a state in which only the lower switch tube is turned on, provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0039] It should be noted that the terms "in one embodiment" or "exemplary" in this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in one embodiment" or "exemplary" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of terms such as "in one embodiment" or "exemplary" is intended to present the relevant concepts in a concrete manner.

[0040] The present application is described in detail below with reference to the accompanying drawings and embodiments:

[0041] like Figure 1As shown, an electric vehicle 100 in the field of new energy vehicles generally includes a powertrain 300 and a power battery 200. The power battery 200 is used to power the powertrain 300. A plurality of powertrains 300 are generally provided in the electric vehicle 100, and each powertrain 300 is powered by the power battery 200. In order to facilitate the control of the powertrain 300, each powertrain 300 is also connected to the vehicle controller 400 in the electric vehicle 100. A control signal can be sent to the motor controller in the powertrain 300 through the vehicle controller 400. The motor controller can receive the control signal and control the torque required for the drive motor to output to provide power to the electric vehicle. As shown in FIG. Figure 2 As shown, the powertrain 300 includes a motor controller 310 and a drive motor 320. The motor controller 310 is used to convert the direct current of the power battery 200 into three-phase alternating current to drive the drive motor 320 to output the required torque.

[0042] Among them, such as Figure 3 As shown, the motor controller 310 includes an inverter circuit 311, a bridge arm drive circuit 312, and a controller 313. The inverter circuit 311 includes three-phase switching tube bridge arms. Each phase switching tube bridge arm includes an upper bridge arm switch and a lower bridge arm switch. The ends of each phase switching tube bridge arm are used to receive power from the vehicle's power battery 200, and the midpoint of each phase switching tube bridge arm is used to output a single-phase AC power to drive the vehicle's drive motor 320. The upper bridge arm switch and the lower bridge arm switch of each phase switching tube bridge arm are used to turn on and off according to a drive signal output by a bridge arm drive circuit, respectively.

[0043] For example, Figure 3As shown, the three-phase switch tube bridge arm may include an A-phase switch tube bridge arm, a B-phase switch tube bridge arm, and a C-phase switch tube bridge arm. The A-phase switch tube bridge arm includes an upper-arm switch tube Q1 and a lower-arm switch tube Q2. The first electrode of the upper-arm switch tube Q1 is connected to the positive electrode of the power battery 200 via the positive DC bus INP. The second electrode of the upper-arm switch tube Q1 and the first electrode of the lower-arm switch tube Q2 are connected to the A-phase winding of the drive motor 320 via the midpoint P1 of the A-phase switch tube bridge arm. The second electrode of the lower-arm switch tube Q2 is connected to the negative electrode of the power battery 200 via the negative DC bus INN. The B-phase switching tube bridge arm includes an upper bridge arm switching tube Q3 and a lower bridge arm switching tube Q4. The first pole of the upper bridge arm switching tube Q3 is connected to the positive pole of the power battery 200 through the positive DC bus INP. The second pole of the upper bridge arm switching tube Q3 and the first pole of the lower bridge arm switching tube Q4 are connected to the B-phase winding of the drive motor 320 through the bridge arm midpoint P2 of the B-phase switching tube bridge arm. The second pole of the lower bridge arm switching tube Q4 is connected to the negative pole of the power battery 200 through the negative DC bus INN. The C-phase switching tube bridge arm includes an upper bridge arm switching tube Q5 and a lower bridge arm switching tube Q6. The first pole of the upper bridge arm switching tube Q5 is connected to the positive pole of the power battery 200 through the positive DC bus INP. The second pole of the upper bridge arm switching tube Q5 and the first pole of the lower bridge arm switching tube Q6 are connected to the C-phase winding of the drive motor 320 through the bridge arm midpoint P3 of the C-phase switching tube bridge arm. The second pole of the lower bridge arm switching tube Q6 is connected to the negative pole of the power battery 200 through the negative DC bus INN.

[0044] The bridge arm drive circuit 312 can output a drive signal to each of the above-mentioned upper bridge arm switch tubes (Q1, Q3 and Q5) and each of the above-mentioned lower bridge arm switch tubes (Q2, Q4 and Q6) through the control signal sent by the controller 313 to control the conduction and shutdown of Q1~Q6, thereby outputting three-phase alternating current to the three-phase winding of the drive motor 320, so that the drive motor 320 outputs the required torque to drive the vehicle to move.

[0045] In the motor controller 310 shown in the embodiment of the present application, the above-mentioned upper bridge arm switch tubes and the lower bridge arm switch tubes can be semiconductor switch tubes, for example, insulated-gate bipolar transistors (IGBTs), silicon carbide (SiC), triodes, metal-oxide-semiconductor field-effect transistors (MOSFETs), etc. In addition, in addition to the upper bridge arm switch tubes or the lower bridge arm switch tubes, the power module can also include a detection module corresponding to each phase bridge arm ( Figure 3The components of the semiconductor switch tube include a short circuit, an open circuit, an abnormal leakage between the emitter (C) and collector (E) of the IGBT, and an abnormal leakage between the source (S) and drain (D) of the MOSFET. Therefore, it is necessary to detect the switch tube to detect the fault in advance and avoid affecting driving safety.

[0046] In some related technologies, in order to detect the failure of a switch tube, it is usually necessary to set up an independent detection circuit for each switch tube. Figure 4 As shown, in order to detect the lower arm switch Q2 of the A-phase switch arm, the detection circuit corresponding to the lower arm switch Q2 generally includes a voltage divider circuit 410, a comparison circuit 420, and a transmission circuit 430. The voltage divider circuit 410 includes a resistor Ra and a resistor Rb. One end of the resistor Ra is connected to the midpoint a of the A-phase switch arm, the other end of the resistor Ra is connected to one end of the resistor Rb, the other end of the resistor Rb is connected to the negative electrode of the power battery 200 via the negative DC bus INN, and the series connection point of the resistor Ra and the resistor Rb is connected to the input end of the comparison circuit 420. The output end of the comparison circuit 420 is connected to the transmission circuit 430. The comparison circuit 420 can compare the output voltage of the series connection point of the resistor Ra and the resistor Rb with a reference voltage, and transmit the comparison result to the controller 313 through the transmission circuit 430, so that the controller 313 can perform subsequent operations based on the comparison result. However, the above method requires the provision of an independent detection circuit for each switch, which makes the structure of the entire motor controller 310 too complicated and increases the cost.

[0047] In order to solve the above problems, Figure 5 As shown, in one embodiment, the present application provides a motor controller 500, which includes an inverter circuit 510, a bridge arm drive circuit 520, a voltage detection circuit 530 and a controller 540. The inverter circuit 510 includes a three-phase switch bridge arm, and the three-phase switch bridge arm can be selected from Figure 3 The structure in the embodiment of the present application is not described in detail here. The voltage detection circuit 530 can output a set of voltage detection signals when one of the upper bridge arm switch tube and the lower bridge arm switch tube of a phase switch tube bridge arm is turned on and the other is turned off. The controller 540 can compare the set of voltage detection signals with a set of reference voltage values. The bridge arm drive circuit 520 can drive the midpoint of the three-phase switch tube bridge arm to output three-phase AC power based on the comparison result of the set of reference voltage values and the set of voltage detection signals.

[0048] In the above implementation, because the equivalent resistance of the windings in the drive motor 320 is in the milliohm range, the midpoints of the three-phase switching tube bridge arms can be equivalently connected in parallel. Based on this, the first voltage detection signals output during the process of turning on an upper-arm switching tube and turning off a lower-arm switching tube in each phase switching tube bridge arm are substantially the same. Simultaneously, the second voltage detection signals output by the voltage detection circuit 530 during the process of turning off an upper-arm switching tube and turning on a lower-arm switching tube in the above-mentioned switching tube bridge arm are also substantially the same. Therefore, a voltage detection circuit can be used to detect an upper-arm switching tube and a lower-arm switching tube in each phase switching tube bridge arm in accordance with the same detection method, as detailed below.

[0049] The controller 540 can send a control signal to the bridge arm drive circuit 520 to control the bridge arm drive circuit 520 to drive one of the upper and lower switching tubes of a phase switching tube bridge arm to turn on and the other to turn off. Simultaneously, while controlling one of the upper and lower switching tubes of a phase switching tube bridge arm to turn on and the other to turn off, the other two phase switching tube bridge arms are controlled to remain off. During this process, the voltage detection circuit 530 can output a set of voltage detection signals to the controller 540. The controller 540 can compare this set of detection signals with the set of reference voltage values to determine, based on the comparison results, whether an upper or lower switching tube of a phase switching tube bridge arm has an open circuit fault.

[0050] When the set of detection signals differs from the set of reference voltages, an upper-arm switch or a lower-arm switch in one of the switching arms of the aforementioned phase has an open-circuit fault. The controller 540 can control the arm drive circuit 520 to turn off one upper-arm switch and one lower-arm switch in each switching arm of the aforementioned phase, and output a corresponding open-circuit fault alarm signal. When the set of detection signals differs from the set of reference voltages, both the upper-arm switch and the lower-arm switch in one of the switching arms of the aforementioned phase are normal. The controller 540 can control the arm drive circuit 520 to turn off one upper-arm switch and one lower-arm switch in one of the switching arms of the aforementioned phase, and then control the arm drive circuit 520 to turn on one of the upper-arm switch and one lower-arm switch in the switching arm of the other phase, while turning off the other. The controller 540 can then continue to test the upper-arm switch and the lower-arm switch in the switching arm of the other phase in accordance with the detection method for the switching arm of the aforementioned phase. The same process is repeated until all the three-phase switch bridge arms have no faults, and then the bridge arm driving circuit 520 is controlled to drive the bridge arm midpoints of the three-phase switch bridge arms to output three-phase AC power.

[0051] In the above manner, the controller 540 can detect the open circuit fault of each phase switch tube bridge arm through a voltage detection circuit 530, and when there is no open circuit fault in each phase switch tube bridge arm, drive the bridge arm midpoint of the three-phase switch tube bridge arm through the bridge arm drive circuit 520 to output three-phase AC power.

[0052] In the above implementation, the set of reference voltage values may include a first reference voltage value and a second reference voltage value. The first reference voltage value is the voltage value of the voltage detection signal output by the voltage detection circuit 530 when both an upper-arm switching tube and a lower-arm switching tube of a phase switching tube bridge arm are normal, during the process when an upper-arm switching tube of a phase switching tube bridge arm is turned on and a lower-arm switching tube is turned off. The second reference voltage value is the voltage value of the voltage detection signal output by the voltage detection circuit 530 when both an upper-arm switching tube and a lower-arm switching tube of a phase switching tube bridge arm are normal, during the process when an upper-arm switching tube of a phase switching tube bridge arm is turned off and a lower-arm switching tube is turned on.

[0053] During testing, the voltage detection circuit 530 can output a first voltage detection signal while an upper-arm switch tube of a phase switch tube bridge arm is turned on and a lower-arm switch tube is turned off. The first voltage detection signal is then compared with a first reference voltage value. When the first reference voltage value differs from the first voltage detection signal, the controller 540 can control the bridge arm drive circuit 520 to stop operating and output an alarm signal indicating an open-circuit fault in an upper-arm switch tube of the corresponding phase switch tube bridge arm. When the first reference voltage value differs from the first voltage detection signal, the controller 540 can continue to control the bridge arm drive circuit 520 to output a second voltage detection signal while an upper-arm switch tube of a phase switch tube bridge arm is turned off and a lower-arm switch tube is turned on.

[0054] Furthermore, when the second voltage detection signal differs from the second reference voltage value, the controller 540 can drive the bridge arm drive circuit 520 to stop operating and output an alarm signal indicating an open circuit fault in a lower-arm switch of the corresponding one-phase switching arm. When the second voltage detection signal is the same as the second reference voltage value, the controller 540 can control the bridge arm drive circuit 520 to shut down one upper-arm switch and one lower-arm switch of the aforementioned one-phase switching arm, and then control one of the upper-arm switch and one lower-arm switch of the other-phase switching arm to turn on and the other to turn off. The controller 540 can then continue to test one upper-arm switch and one lower-arm switch of the other-phase switching arm using the same testing method as described above for the one-phase switching arm. This process continues in this manner until one upper-arm switch and one lower-arm switch of each phase switching arm are normal, at which point the controller 540 controls the bridge arm drive circuit 520 to drive the midpoints of the three-phase switching arms to output three-phase AC power.

[0055] In one embodiment, considering that after the three-phase switching tube bridge arm is powered on, one upper-arm switching tube and one lower-arm switching tube in each phase switching tube bridge arm are both in the off state, if a short-circuit fault occurs in one of the upper-arm switching tubes or one of the lower-arm switching tubes in each phase switching tube bridge arm, it may affect the safety of vehicle operation. Therefore, the voltage detection circuit 530 may further output another set of voltage detection signals while one upper-arm switching tube and one lower-arm switching tube in a phase switching tube bridge arm are turned off. The controller 540 then determines whether a short-circuit fault exists in the phase switching tube bridge arm based on a comparison result of another set of reference voltage values with the above-mentioned another set of voltage detection signals. If the other set of reference voltage values is the same as the above-mentioned another set of voltage detection signals, the phase switching tube bridge arm does not have a short-circuit fault. If the other set of reference voltage values is different from the above-mentioned another set of voltage detection signals, the phase switching tube bridge arm has a short-circuit fault.

[0056] Furthermore, when the motor controller 500 includes only one voltage detection circuit 530, the short-circuit fault of the three-phase switch tube bridge arm can be uniformly detected using the comparison results of the above-mentioned another set of reference voltage values and the above-mentioned another set of voltage detection signals, thereby reducing the number of voltage detection circuits and further reducing costs.

[0057] Through the above method, the possible open circuit faults and short circuit faults in the three-phase switch bridge arm can be fully detected, and the fault problems can be discovered in time to avoid affecting driving safety.

[0058] Still Figure 5As shown, to achieve the above-mentioned short-circuit fault detection and open-circuit fault detection, the voltage detection circuit 530 may include a first resistor R1 and a second resistor R2. One end of the first resistor R1 is used to connect to the midpoint a of the bridge arm of the phase A switching tube, the other end of the first resistor R1 is used to connect to one end of the second resistor, and the other end of the second resistor R2 is connected to the negative electrode of the power battery. The series connection point of the first resistor R1 and the second resistor R2 is used to output a set of voltage detection signals when one of an upper-arm switching tube and a lower-arm switching tube of a phase switching tube bridge arm is turned on and the other is turned off, and to output another set of voltage detection signals when one of an upper-arm switching tube and a lower-arm switching tube of a phase switching tube bridge arm is turned off and the other is turned off.

[0059] By using the voltage division of the first resistor R1 and the second resistor R2, the short circuit fault and the open circuit fault of the three-phase switch bridge arm can be detected in the following manner.

[0060] 1) Detecting an open circuit fault of an upper-arm switching tube or a lower-arm switching tube in a phase switching tube bridge arm during a process in which one of an upper-arm switching tube and a lower-arm switching tube is turned on and the other is turned off.

[0061] For example, taking the A-phase switch arm as an example, when the upper-arm switch Q1 in the A-phase switch arm is turned on and the lower-arm switch Q2 is turned off, the voltage of the power battery 200 (denoted as Ua) is only divided by the first resistor R1 and the second resistor R2. Under normal circumstances, the voltage value of the first voltage detection signal output by the voltage detection circuit 530 should be the first reference voltage value R2*Ua / (R1+R2). If the upper-arm switch Q1 has an open circuit fault or abnormal conduction, the voltage at the midpoint a of the A-phase switch arm is Ua / 2. At this time, Ua / 2 is divided by the first resistor R1 and the second resistor R2. The voltage value of the first voltage detection signal output by the voltage detection circuit 530 is R2*Ua 2 Therefore, when the first voltage detection signal is different from the first reference voltage value, it can be determined based on the voltage value that the upper arm switch tube Q1 has an open circuit fault or conduction abnormality.

[0062] When the upper arm switch Q1 in the A-phase switch arm is turned off and the lower arm switch Q2 is turned on, the voltage value of the first voltage detection signal output by the voltage detection circuit 530 is zero (i.e., the second reference voltage value). If the lower arm switch Q2 has an open circuit fault or conduction abnormality, the voltage value of the second voltage detection signal output by the voltage detection circuit 530 is R2*Ua. 2 Therefore, when the second voltage detection signal is different from the second reference voltage value, it can be determined based on the voltage value that the lower arm switch tube Q2 has an open circuit fault or conduction abnormality.

[0063] 2) Turn off an upper-arm switch tube and a lower-arm switch tube of each phase switch tube bridge arm.

[0064] For example, still taking the A-phase switch bridge arm as an example, when the upper bridge arm switch tube Q1 and the lower bridge arm switch tube Q2 of the A-phase switch bridge arm are turned off, if the upper bridge arm switch tube Q1 and the lower bridge arm switch tube Q2 are both normal, the voltage detection signal output by the voltage detection circuit 530 has a voltage value of R2*Ua. 2 / 2(R1+R2). If the upper-arm switch Q1 has a short-circuit fault, the voltage detection signal output by the voltage detection circuit 530 has a voltage value of R2*Ua / (R1+R2). If the lower-arm switch Q2 has a short-circuit fault, the voltage detection signal output by the voltage detection circuit 530 has a voltage value of zero. Based on this, when the other set of reference voltage values is different from the other set of voltage detection signals, it can be determined based on the voltage values whether the upper-arm switch Q1 or the lower-arm switch Q2 has a short-circuit fault.

[0065] Similarly, the open circuit fault and short circuit fault of the B-phase switch tube bridge arm and the C-phase switch tube bridge arm can be detected in the above manner, which will not be described in detail in the embodiment of the present application.

[0066] In one embodiment, Figure 5 As shown, the voltage detection circuit 530 further includes a first π-type filter circuit 531 consisting of a first capacitor C1, a second capacitor C2, and a fourth resistor R10. One end of the first capacitor C1 is connected to the series connection point of the first resistor R1 and the second resistor R2, and the other end of the first capacitor C1 is connected to the negative electrode of the power battery 200. One end of the fourth resistor R10 is connected to the series connection point of the first resistor R1 and the second resistor R2, and the other end of the fourth resistor R10 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the negative electrode of the power battery 200. The connection point between the fourth resistor R10 and the second capacitor C2 is used to output the filtered voltage detection signal.

[0067] Through the above method, the voltage detection signal outputted from the series connection point of the first resistor R1 and the second resistor R2 can be made more accurate. Of course, the first π-type filter circuit 531 can be selectively configured, and this embodiment of the present application does not impose any specific restrictions on this. In addition, one end of the first resistor R1 can also be selectively connected to the midpoint b of the bridge arm of the B-phase switch tube or the midpoint c of the bridge arm of the C-phase switch tube, and this embodiment of the present application does not impose any specific restrictions on this.

[0068] In one embodiment, if Figure 6As shown, the motor controller 500 may further include the other two voltage detection circuits 530 , which correspond to the other two-phase switch bridge arms respectively.

[0069] For example, Figure 6 As shown, in Figure 5 Based on the above, the voltage detection circuit corresponding to the B-phase switching arm includes resistors R4 and R5. One end of resistor R4 is connected to the midpoint b of the B-phase switching arm, and the other end of resistor R4 is connected to one end of resistor R5. The other end of resistor R5 is connected to the negative electrode of power battery 200. The series connection point of resistors R4 and R5 is used to output a set of voltage detection signals when one of the upper-arm switching tube and the lower-arm switching tube of the B-phase switching arm is turned on and the other is turned off, and to output another set of voltage detection signals when one of the upper-arm switching tube and the lower-arm switching tube of the B-phase switching arm is turned off.

[0070] The voltage detection circuit corresponding to the C-phase switching arm includes resistors R7 and R8. One end of resistor R7 is connected to the midpoint c of the C-phase switching arm, and the other end of resistor R7 is connected to one end of resistor R8, the other end of which is connected to the negative electrode of power battery 200. The series connection point between resistors R7 and R8 is used to output a set of voltage detection signals when one of the upper-arm switching tube and the lower-arm switching tube of the C-phase switching arm is turned on and the other is turned off, and to output another set of voltage detection signals when one of the upper-arm switching tube and the lower-arm switching tube of the C-phase switching arm is turned off.

[0071] In the above manner, the open circuit fault and short circuit fault of each phase switch bridge arm can be detected by the corresponding voltage detection circuit 530. Figure 5 In comparison, the open circuit fault and short circuit fault of each phase switch tube bridge arm can not only be detected by the corresponding voltage detection circuit 530, but also more accurately locate an upper bridge arm switch tube or a lower bridge arm switch tube with a short circuit fault.

[0072] In one embodiment, Figure 6As shown, the voltage detection circuit corresponding to the B-phase switching arm may further include a second π-type filter circuit 532 consisting of capacitors C3, C4, and resistor R11. One end of capacitor C3 is connected to the series connection point of resistors R4 and R5, and the other end of capacitor C3 is connected to the negative electrode of power battery 200. One end of resistor R11 is connected to the series connection point of resistors R4 and R5, and the other end of resistor R11 is connected to one end of capacitor C4, which is connected to the negative electrode of power battery 200. The connection point between resistors R11 and capacitor C4 is used to output a filtered voltage detection signal. The voltage detection circuit corresponding to the C-phase switching arm may further include a third π-type filter circuit 533 consisting of capacitors C5, C6, and resistor R12. Among them, one end of capacitor C5 is connected to the series point of resistor R7 and resistor R8, the other end of capacitor C5 is connected to the negative electrode of power battery 200, one end of resistor R12 is connected to the series point of resistor R7 and resistor R8, the other end of resistor R12 is connected to one end of capacitor C6, the other end of capacitor C6 is connected to the negative electrode of power battery 200, and the connection point between resistor R12 and capacitor C6 is used to output the filtered voltage detection signal.

[0073] In one embodiment, if Figure 7 As shown, in Figure 6 On the basis of, the motor controller 500 may further include a multiplexer 550. The multiplexer 550 may include three input terminals, an output terminal and a control terminal. Among them, the connection point of the fourth resistor R10 and the second capacitor C2 is connected to the first input terminal of the multiplexer 550, the connection point of the resistor R11 and the capacitor C4 is connected to the second input terminal of the multiplexer 550, and the connection point of the resistor R12 and the capacitor C6 is connected to the third input terminal of the multiplexer 550. The control terminal and the output terminal of the multiplexer 550 are both connected to the controller 540. In the process of one of the upper bridge arm switch tube and the lower bridge arm switch tube of a phase switch tube bridge arm being turned on and the other being turned off, the controller 540 can send a control signal to the control terminal of the multiplexer 550 to turn on the corresponding input terminal and the output terminal, so that the switch tube bridge arms of each phase can be detected in a time-division multiplexing manner.

[0074] In one embodiment, if Figure 8As shown, the voltage detection circuit 530 includes a first resistor R1, a second resistor R2 and a third resistor R3. One end of the first resistor R1 is connected to the midpoint a of the bridge arm of the A-phase switch tube bridge arm, the other end of the first resistor R1 is used to connect to one end of the second resistor, and the other end of the second resistor R2 is connected to the negative electrode of the power battery 200. The series connection point of the first resistor R1 and the second resistor R2 is used to output a set of voltage detection signals during the process in which one of the upper bridge arm switch tube and the lower bridge arm switch tube of a phase switch tube bridge arm is turned on and the other is turned off, and to output another set of voltage detection signals during the process in which one of the upper bridge arm switch tube and the lower bridge arm switch tube of a phase switch tube bridge arm is turned off and a lower bridge arm switch tube is turned off. One end of the third resistor R3 is connected to the positive electrode of the power battery 200, and the other end of the third resistor R3 is connected to the midpoint a of the bridge arm of the A-phase switch tube bridge arm. On this basis, the series connection point of the first resistor R1 and the second resistor R2 can also be connected to the controller 540 through a π-type filter circuit. The π-type filter circuit can be selected from Figure 5 The structure in the embodiment of the present application will not be described in detail here.

[0075] In the above implementation process, the first resistor R1 and the third resistor R3 can be equivalent resistors. For example, the first resistor R1 and the third resistor R3 can be composed of multiple small resistors in series, or the first resistor R1 and the third resistor R3 can be composed of multiple large resistors in parallel. In addition, in order to adapt to different levels of operating voltage, the number of resistors equivalent to the first resistor R1 and the third resistor R3 can also be adjusted according to actual needs. Of course, the first resistor R1 and the third resistor R3 can also select other equivalent circuits composed of devices that can be used as resistors, and the embodiments of the present application do not impose specific restrictions on this.

[0076] In one embodiment, if Figure 9 As shown, the motor controller 500 further includes the other two voltage detection circuits 530, which correspond to the other two-phase switch bridge arms. Figure 8 Based on the circuit diagram, the voltage detection circuit corresponding to the B-phase switching arm includes resistors R4, R5, and R6. One end of resistor R4 is connected to the midpoint b of the B-phase switching arm, and the other end of resistor R4 is connected to one end of resistor R5. The other end of resistor R5 is connected to the negative electrode of power battery 200. The series connection point between resistors R4 and R5 is used to output a set of voltage detection signals when one of the upper and lower switching arms of the B-phase switching arm is turned on and the other is turned off, and to output another set of voltage detection signals when one of the upper and lower switching arms of the B-phase switching arm is turned off. One end of resistor R6 is connected to the positive electrode of power battery 200, and the other end of resistor R6 is connected to the midpoint b of the B-phase switching arm.

[0077] The voltage detection circuit corresponding to the C-phase switching arm includes resistors R7, R8, and R9. One end of resistor R7 is connected to the midpoint c of the C-phase switching arm. The other end of resistor R7 is connected to one end of resistor R8, and the other end of resistor R8 is connected to the negative electrode of power battery 200. The series connection between resistors R7 and R8 is used to output a set of voltage detection signals when one of the upper and lower switching arms of the C-phase switching arm is on and the other is off, and to output another set of voltage detection signals when one of the upper and lower switching arms of the C-phase switching arm is off. One end of resistor R9 is connected to the positive electrode of power battery 200, and the other end of resistor R9 is connected to the midpoint c of the C-phase switching arm.

[0078] It can be understood that the above-mentioned resistors R4, R6, R7 and R9 can also be equivalent resistors like the first resistor R1 and the third resistor R3, and are not described in detail in the embodiment of the present application.

[0079] In one embodiment, Figure 9 As shown, the motor controller 500 may further include three π-type filter circuits, and each π-type filter circuit corresponds to a phase switch bridge arm. The specific configuration of the three π-type filter circuits can be referred to Figure 6 The configuration is performed in a manner that will not be described in detail in the embodiments of the present application.

[0080] In one embodiment, if Figure 10 As shown, in Figure 9 On the basis of, the motor controller 500 may further include a multiplexer 550. The multiplexer 550 may include three input terminals, an output terminal and a control terminal. Among them, the connection point of the fourth resistor R10 and the second capacitor C2 is connected to the first input terminal of the multiplexer 550, the connection point of the resistor R11 and the capacitor C4 is connected to the second input terminal of the multiplexer 550, and the connection point of the resistor R12 and the capacitor C6 is connected to the third input terminal of the multiplexer 550. The control terminal and the output terminal of the multiplexer 550 are both connected to the controller 540. In the process of one of the upper bridge arm switch tube and the lower bridge arm switch tube of a phase switch tube bridge arm being turned on and the other being turned off, the controller 540 can send a control signal to the control terminal of the multiplexer 550 to turn on the corresponding input terminal and the output terminal, so that the switch tube bridge arms of each phase can be detected in a time-division multiplexing manner.

[0081] When the motor controller 500 is selected Figure 8 or Figure 9 When the structure is in, the short-circuit fault and open-circuit fault of the three-phase switch bridge arm can be detected in the following way.

[0082] 1) Turn off an upper-arm switch tube and a lower-arm switch tube of each phase switch tube bridge arm.

[0083] In one example, Figure 8 Taking the motor controller 500 in FIG. 5 as an example, when the motor controller 500 includes only one voltage detection circuit 530, when one upper bridge arm switch tube and one lower bridge arm switch tube of each phase switch tube bridge arm are both turned off, if all the switch tubes are normal, the voltage Ua of the power battery 200 is divided by the first resistor R1, the second resistor R2 and the third resistor R3. At this time, the voltage detection signal output by the voltage detection circuit 530 in the normal state has a voltage value of the reference voltage value Typ1. Figure 11 As shown, taking the A-phase switch arm as an example, when both the upper-arm switch Q1 and the lower-arm switch Q2 are turned off, both the upper-arm switch Q1 and the lower-arm switch Q2 of the A-phase switch arm are normally in an open-circuit state. At this time, the voltage detection signal output by the voltage detection circuit 530 has a voltage value of Typ1. If the upper-arm switch Q1 has a short-circuit fault or leakage anomaly, the third resistor R3 is short-circuited, and the voltage divided by the second resistor R2 increases, causing the voltage detection signal output by the voltage detection circuit 530 to have a voltage value greater than Typ1. If the lower-arm switch Q2 has a short-circuit fault or leakage anomaly, the first resistor R1 and the second resistor R2 are short-circuited, and the voltage divided by the second resistor R2 decreases, causing the voltage detection signal output by the voltage detection circuit 530 to have a voltage value less than Typ1.

[0084] When using a single voltage detection circuit 530, because the equivalent resistance of the windings in the drive motor 320 is in the milliohm range, the midpoints of the three-phase switch arms can be equivalently connected in parallel. Therefore, when a short circuit occurs in one of the upper-arm switch arms or one of the lower-arm switch arms in the B-phase switch arm and the C-phase switch arm, the voltage detection signal output by the voltage detection circuit 530 is the same as that in the A-phase switch arm. Therefore, during detection, if the voltage detection signal output by the voltage detection circuit 530 is greater than Typ1, any of the upper-arm switch arms Q1, Q3, and Q5 in the three-phase switch arms has a leakage anomaly (e.g., an IGBT's C- and E-pole leakage anomaly or a MOSFET's S- and D-pole leakage anomaly) or a short circuit. If the voltage value of the voltage detection signal output by the voltage detection circuit 530 is less than Typ1, any one of the upper arm switch tubes Q2, Q4, and Q6 in the three-phase switch tube bridge arm has a leakage abnormality (for example, leakage abnormality between the C pole and the E pole of the IGBT / leakage abnormality between the S pole and the D pole of the MOSFET) or a short circuit fault.

[0085] In the above implementation process, the specific value of Typ1 can be adaptively set according to the type of switch tube actually used in the three-phase switch tube bridge arm, the duty cycle of the switch tube, and the voltage provided by the power battery, etc. The embodiment of the present application does not impose specific restrictions on this.

[0086] In another example, Figure 9 For example, when the motor controller 500 includes three voltage detection circuits 530, each voltage detection circuit 530 can refer to Figure 8 A single voltage detection circuit 530 is used to detect a short circuit fault of a corresponding phase switch bridge arm.

[0087] For example, after the motor controller 500 is powered on, one upper-arm switch tube and one lower-arm switch tube of each phase switch tube bridge arm are both turned off. At this time, each voltage detection circuit 530 can output a voltage detection signal outputted at the midpoint of the bridge arm corresponding to the phase switch tube bridge arm to the controller 540. The controller 540 can determine whether a short circuit fault exists in one upper-arm switch tube and one lower-arm switch tube of each phase switch tube bridge arm based on the received voltage detection signal. In the case that neither one upper-arm switch tube nor one lower-arm switch tube of each phase switch tube bridge arm has an open circuit fault, the controller 540 can control the bridge arm drive circuit 520 to drive one of one upper-arm switch tube and one lower-arm switch tube of one phase switch tube bridge arm to turn on and the other to turn off, and drive the other two phase switch tube bridge arms to remain turned off, so as to detect an open circuit fault in each phase switch tube bridge arm.

[0088] 2) Detecting an open circuit fault of a switching tube in a phase switching tube bridge arm during a process in which one of an upper bridge arm switching tube and a lower bridge arm switching tube is turned on and the other is turned off.

[0089] For example, when using Figure 8 When the motor controller 500 is used, the upper bridge arm switch tube Q1 and the lower bridge arm switch Q2 of the A-phase switch tube bridge arm are taken as an example. Before the controller 540 controls the bridge arm drive circuit 520 to drive the three-phase switch tube bridge arm to normally output three-phase AC power, the upper bridge arm switch tube Q1 and the lower bridge arm switch tube Q2 of the A-phase switch tube bridge arm can be alternately turned on according to different duty cycles. Because the upper bridge arm switch tube and the lower bridge arm switch tube of the A-phase switch tube bridge arm are alternately turned on in a manner with different duty cycles and the conduction time is very short, the voltage value of the voltage detection signal output by the voltage detection circuit 530 in the normal state is the reference voltage value Typ2. Figure 12As shown, when the upper arm switch tube Q1 of the A-phase switch tube bridge arm is normally turned on and the lower arm switch tube Q2 is turned off, the third resistor R3 is short-circuited, and the voltage output by the power battery 200 is mainly divided by the first resistor R1 and the second resistor R2. However, if the upper arm switch tube Q1 is abnormally turned on or has an open circuit fault, the voltage output by the power battery 200 needs to be divided by the first resistor R1, the second resistor R2 and the third resistor R3. At this time, the voltage value of the voltage detection signal outputted from the connection point of the first resistor R1 and the second resistor R2 will decrease, that is, it will be less than Typ2. As shown in FIG. Figure 13 As shown, when the upper-arm switch Q1 of the A-phase switching arm is normally off and the lower-arm switch Q2 is on, the first resistor R1 and the second resistor R2 are briefly short-circuited. At this time, because the upper-arm switch Q1 and the lower-arm switch Q2 are alternately turned on with different duty cycles, the voltage detection signal output by the voltage detection circuit 530 remains at Typ2. If the lower-arm switch Q2 is abnormally turned on or has an open-circuit fault, the first resistor R1 and the second resistor R2 will not be briefly short-circuited. The voltage output by the power battery 200 can be divided by the first resistor R1, the second resistor R2, and the third resistor R3. In this case, the voltage detection signal output at the connection point between the first resistor R1 and the second resistor R2 will increase in voltage, that is, exceed Typ2.

[0090] Therefore, when the upper and lower bridge arm switches of each phase bridge arm are alternately turned on with different duty cycles, if the upper bridge arm switch Q1 of the phase A switch arm is turned on and the lower bridge arm switch Q2 is turned off, the controller 540 can compare the voltage value of the voltage detection signal output from the connection point of the first resistor R1 and the second resistor R2 with Typ2. If the voltage value of the voltage detection signal output from the connection point of the first resistor R1 and the second resistor R2 is less than Typ2, the upper bridge arm switch Q1 is abnormally turned on or has an open circuit fault. If the voltage value of the voltage detection signal output from the connection point of the first resistor R1 and the second resistor R2 is greater than Typ2, the lower bridge arm switch Q2 is abnormally turned on or has an open circuit fault. Similarly, the upper bridge arm switch Q3 and the lower bridge arm switch Q4 of the phase B switch arm, and the upper bridge arm switch Q5 and the lower bridge arm switch Q6 of the phase C switch arm can also be detected in accordance with the above method. The embodiments of the present application are not described in detail here.

[0091] It can be understood that the specific value of Typ2 can also be adaptively set according to the type of switch tube actually used in the three-phase switch tube bridge arm, the duty cycle of the switch tube, and the voltage provided by the power battery, etc. The embodiment of the present application does not impose specific restrictions on this.

[0092] Furthermore, when using Figure 9 In the motor controller 500, each voltage detection circuit 530 can refer to Figure 8 The single voltage detection circuit 530 is used to detect the open circuit fault of the corresponding phase switch bridge arm, which will not be described in detail in the embodiment of the present application.

[0093] In summary, embodiments of the present application provide a motor controller, powertrain, and electric vehicle for use in the field of new energy vehicle technology. The motor controller includes a three-phase switching tube bridge arm, a bridge arm drive circuit, and a voltage detection circuit. Each phase switching tube bridge arm includes an upper bridge arm switching tube and a lower bridge arm switching tube. The ends of each phase switching tube bridge arm are used to receive power from a power battery, and the midpoint of each phase switching tube bridge arm is used to output a single-phase alternating current to drive the vehicle's drive motor. The voltage detection circuit is capable of outputting a set of voltage detection signals when one of the upper bridge arm switching tube and the lower bridge arm switching tube of a phase switching tube bridge arm is turned on and the other is turned off. The bridge arm drive circuit is capable of driving the midpoints of the three-phase switching tube bridge arms to output three-phase alternating current based on a comparison result between a set of reference voltage values and the set of voltage detection signals. Based on this, multiple switching tubes can be detected by a single detection circuit, achieving detection of the switching tubes while reducing costs.

[0094] In addition, each functional module in each embodiment of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0095] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A motor controller, characterized in that: The motor controller includes a three-phase switching tube bridge arm, a bridge arm drive circuit, and a voltage detection circuit. Each phase of the switching tube bridge arm includes an upper bridge arm switching tube and a lower bridge arm switching tube. The two ends of the bridge arm of each phase of the switching tube bridge arm are used to receive power from the vehicle's power battery. The midpoint of the bridge arm of each phase of the switching tube bridge arm is used to output a single-phase AC power to drive the vehicle's drive motor. The upper bridge arm switching tube and the lower bridge arm switching tube of each phase of the switching tube bridge arm are used to be turned on and off respectively according to a drive signal output by the bridge arm drive circuit, wherein: The voltage detection circuit is used to output a set of voltage detection signals during a process in which one of the upper bridge arm switch tube and the lower bridge arm switch tube of the switching tube bridge arm of one phase is turned on and the other is turned off; The one bridge arm driving circuit is used to drive the bridge arm midpoint of the three-phase switch tube bridge arm to output three-phase alternating current according to the comparison result of a group of reference voltage values and the group of voltage detection signals.

2. The motor controller according to claim 1, characterized in that: The group of voltage detection signals includes a first voltage detection signal, and the voltage detection circuit is used to output the first voltage detection signal when the upper arm switch tube of the switch tube bridge arm of one phase is turned on and the lower arm switch tube is turned off.

3. The motor controller according to claim 1 or 2, characterized in that: The group of voltage detection signals includes a second voltage detection signal, and the voltage detection circuit is used to output the second voltage detection signal when the upper arm switch tube of the switch tube bridge arm of one phase is turned off and the lower arm switch tube is turned on.

4. The motor controller according to any one of claims 1 to 3, characterized in that: The voltage detection circuit includes a first resistor and a second resistor, one end of the first resistor is used to connect to the midpoint of the bridge arm of the switching tube of one phase, the other end of the first resistor is used to connect to one end of the second resistor, the other end of the second resistor is connected to the negative electrode of the power battery, and the series connection point of the first resistor and the second resistor is used to output the set of voltage detection signals.

5. The motor controller according to claim 4, characterized in that: The one voltage detection circuit is also used to output another set of voltage detection signals during the process of turning off the one upper arm switch tube and the one lower arm switch tube of the one-phase switch tube bridge arm. The one bridge arm driving circuit is used to drive the bridge arm midpoint of the three-phase switch tube bridge arm to output three-phase alternating current based on the comparison results of the one set of reference voltage values and the one set of voltage detection signals, and the comparison results of another set of reference voltage values and the another set of voltage detection signals.

6. The motor controller according to claim 5, characterized in that: The voltage detection circuit also includes a third resistor, one end of the third resistor is used to be connected in series with one end of the first resistor, and the other end of the third resistor is used to be connected to the positive end of the switching tube bridge arm of one phase, and the series connection point of the first resistor and the second resistor is also used to output the other set of voltage detection signals.

7. The motor controller according to claim 5 or 6, characterized in that: The one bridge arm driving circuit is used to drive the bridge arm midpoint of the three-phase switching tube bridge arm to output three-phase alternating current when the other group of reference voltage values is the same as the other group of voltage detection signals and the one group of reference voltage values is the same as the one group of voltage detection signals.

8. The motor controller according to any one of claims 5 to 7, characterized in that: The one bridge arm driving circuit is also used to control one of the upper bridge arm switch tube and the one lower bridge arm switch tube of one phase of the switching tube bridge arm to be turned on and the other to be turned off when the other set of reference voltage values of the one phase of the switching tube bridge arm is the same as the other set of voltage detection signals.

9. The motor controller according to any one of claims 1 to 8, characterized in that: The one bridge arm driving circuit is also used to control the other two phases of the switching tube bridge arms to remain turned off during the process of controlling one of the upper bridge arm switching tube and the lower bridge arm switching tube of one phase to be turned on and the other to be turned off.

10. The motor controller according to any one of claims 4 to 8, characterized in that: The voltage detection circuit also includes a first capacitor, a second capacitor and a fourth resistor, one end of the first capacitor is connected to the series point, the other end of the first capacitor is connected to the negative electrode of the power battery, one end of the fourth resistor is connected to the series point, the other end of the fourth resistor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the negative electrode of the power battery. The connection point between the fourth resistor and the second capacitor is used to output a filtered voltage detection signal.

11. The motor controller according to any one of claims 1 to 10, characterized in that: The one bridge arm driving circuit is further used for: When the set of reference voltage values is the same as the set of voltage detection signals, the upper bridge arm switch tube and the lower bridge arm switch tube of one phase of the switch tube bridge arm are first turned off, and then one of the upper bridge arm switch tube and the lower bridge arm switch tube of the other phase of the switch tube bridge arm is controlled to be turned on and the other turned off.

12. The motor controller according to any one of claims 1 to 11, characterized in that: The one bridge arm driving circuit is also used to control the one upper bridge arm switch tube and the one lower bridge arm switch tube in each phase of the switch tube bridge arm to turn off when the set of reference voltage values is different from the set of voltage detection signals.

13. The motor controller according to any one of claims 1 to 10, characterized in that: The motor controller further includes two other voltage detection circuits and a controller, wherein the other two voltage detection circuits correspond to the switch tube bridge arms of the other two phases respectively, wherein: The one bridge arm driving circuit is further configured to control the one upper bridge arm switching tube and the one lower bridge arm switching tube in the switching tube bridge arms of the other two phases to remain turned off during a process in which one of the upper bridge arm switching tube and the one lower bridge arm switching tube in the switching tube bridge arms of one phase is turned on and the other is turned off; The controller is used to compare the set of detection signals output by the voltage detection circuit corresponding to the switching tube bridge arm of one phase with the set of reference voltage values when one of the upper arm switching tube and the lower arm switching tube of the switching tube bridge arm of one phase is turned on and the other is turned off.

14. A powertrain, characterized in that: The powertrain includes a drive motor and a motor controller according to any one of claims 1 to 13, wherein the motor controller is configured to output three-phase current to control the drive motor.

15. An electric vehicle, characterized in that: The electric vehicle includes a power battery and the powertrain according to claim 14 , wherein the power battery is used to power the motor controller in the powertrain.

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