Motor control system and automobile

Abstract

The invention provides a motor control system and an automobile, which can reliably execute three-phase active short circuit of a motor under the condition of failure of a single-point power supply. The motor control system comprises a bus capacitor and a motor. The motor is connected with the positive direct-current bus and the negative direct-current bus through the three-phase inverter bridge, and the positive direct-current bus and the negative direct-current bus are connected with the positive end and the negative end of the bus capacitor respectively; each phase of inverter bridge comprises an upper bridge arm connected with a positive direct current bus and a lower bridge arm connected with a negative direct current bus; in addition, the motor control system further comprises an upper gate pole driving circuit, a lower gate pole driving circuit, a first power supply unit and a second power supply unit. The first power supply unit is connected with three upper bridge arms in the three-phase inverter bridge through an upper gate pole driving circuit; and the second power supply unit is connected with three lower bridge arms in the three-phase inverter bridge through a lower gate pole driving circuit.

Description

[0001] This application is a divisional application. The application number of the original application is 202110051283.2, and the original application date is January 14, 2021. The entire content of the original application is incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of motor control, and in particular to a motor control system and a vehicle. Background Art

[0003] Pure electric vehicles or hybrid electric vehicles are gaining an increasingly larger market share. When a synchronous motor is used as a power drive, in the event of a motor control system failure, it is usually necessary to actively short-circuit the three phases of the motor through a gate drive unit to avoid generating unexpected braking torque and damage to related devices due to motor energy backflow.

[0004] However, in the related art, the gate drive unit is powered by a single-point power supply. In this case, if the single-point power supply fails, the gate drive unit cannot actively short-circuit the three phases of the motor. Summary of the Invention

[0005] The present application provides a motor control system and a vehicle, which can reliably perform active short circuit of the three phases of the motor in the event of a single-point power failure.

[0006] The present application provides a motor control system including: a bus capacitor and a motor; wherein the motor is connected to a positive DC bus and a negative DC bus through a three-phase (U, V, W) inverter bridge, and the positive DC bus and the negative DC bus are respectively connected to the positive end and the negative end of the bus capacitor; each phase inverter bridge includes: an upper bridge arm connected to the positive DC bus and a lower bridge arm connected to the negative DC bus.

[0007] The above-mentioned motor control system also includes: an upper gate drive circuit, a lower gate drive circuit, a first power supply unit, and a second power supply unit; wherein the first power supply unit is connected to the three upper bridge arms (i.e., the upper three bridges) in the three-phase inverter bridge through the upper gate drive circuit; the second power supply unit is connected to the three lower bridge arms (i.e., the lower three bridges) in the three-phase inverter bridge through the lower gate drive circuit.

[0008] The motor control system provided in the present application, by respectively setting independent gate drive circuits and power supply units for the three upper bridge arms and the three lower bridge arms in the three-phase inverter bridge, on the one hand, can reduce the cost of the control system while ensuring that the entire control system has a simple architecture; on the other hand, even in the event of a failure of a single power supply unit (i.e., a single-point power failure), the reliable execution of the three-phase active short circuit of the motor can still be ensured through another set of power supply units and gate drive circuits, thereby meeting the functional safety requirements of the motor control system.

[0009] In some possible implementations, the first power supply unit includes a first power conversion unit and a first power supply; the input end of the first power conversion unit is connected to the first power supply, and the output end of the first power conversion unit is connected to the upper gate drive circuit; the second power supply unit includes a second power conversion unit and a second power supply; the input end of the second power conversion unit is connected to the second power supply, and the output end of the second power conversion unit is connected to the lower gate drive circuit.

[0010] In some possible implementations, the first power source utilizes a bus capacitor, and the first power conversion unit utilizes a high-voltage bus step-down conversion circuit; the high-voltage bus step-down conversion circuit is connected to the bus capacitor via a positive DC bus and a negative DC bus; the second power source utilizes a low-voltage battery power source; and the second power conversion unit utilizes a low-voltage battery power conversion circuit. In this case, the power output from the first power source is regulated by the first power conversion unit and then output to the upper gate drive circuit, which then supplies power to the upper three bridges; the power output from the second power source is regulated by the second power conversion unit and then output to the lower gate drive circuit, which then supplies power to the lower three bridges.

[0011] In some possible implementations, the first power supply adopts a low-voltage battery power supply, and the first power conversion unit adopts a low-voltage battery power conversion circuit; the second power supply adopts a bus capacitor, and the second power conversion unit adopts a high-voltage bus step-down conversion circuit; the high-voltage bus step-down conversion circuit is connected to the bus capacitor through a positive DC bus and a negative DC bus.

[0012] In some possible implementations, the high-voltage bus step-down conversion circuit includes a first PWM controller and a first multi-winding transformer; the first multi-winding transformer includes a first primary winding and three groups of first secondary winding units.

[0013] The above-mentioned first PWM controller is connected to the gate of the first transistor, one electrode of the first transistor is connected to the same-name end of the first primary winding, the other electrode of the first transistor is connected to the first end of the first resistor and is connected to the first PWM controller; the second end of the first resistor is connected to the negative end of the bus capacitor through the negative DC bus; the non-same-name end of the first primary winding is connected to the positive end of the bus capacitor through the positive DC bus.

[0014] The above-mentioned first secondary winding unit includes a first secondary winding, a second secondary winding, a first capacitor, a second capacitor, a first diode, and a second diode; wherein, the non-identical ends of the first secondary winding are connected to the identical ends of the second secondary winding; the identical ends of the first secondary winding are connected to the anode of the first diode, and the non-identical ends of the second secondary winding are connected to the cathode of the second diode; the two ends of the first capacitor are connected between the cathode of the first diode and the non-identical ends of the first secondary winding, and the two ends of the second capacitor are connected between the anode of the second diode and the identical ends of the second secondary winding.

[0015] The output networks of the three groups of first secondary winding units are connected to the upper gate drive circuit or the lower gate drive circuit to supply power to the upper three bridges or the lower three bridges in the three-phase (U, V, W) inverter bridge.

[0016] In some possible implementations, the first multi-winding transformer also includes a third secondary winding, a third diode, and a third capacitor; wherein the like-name end of the third secondary winding is connected to the anode of the third diode, and the non-like-name end of the third secondary winding is connected to the ground end; the two ends of the third capacitor are connected between the cathode of the third diode and the non-like-name end of the third secondary winding; power is supplied to the isolation driver chip in the upper gate drive circuit or the lower gate drive circuit through the two output networks of the secondary winding, so as to output a control signal to the three-phase inverter bridge through the isolation driver chip.

[0017] In some possible implementations, the low-voltage battery power conversion circuit includes a second PWM controller and a second multi-winding transformer; the second multi-winding transformer includes a second primary winding and three groups of second secondary winding units.

[0018] The above-mentioned second secondary winding unit includes a fourth secondary winding, a fifth secondary winding, a fourth diode, a fifth diode, a fourth capacitor, and a fifth capacitor; the non-like-name end of the fourth secondary winding is connected to the like-name end of the fifth secondary winding, and is connected to the ground end; the like-name end of the fourth secondary winding is connected to the anode of the fourth diode; the non-like-name end of the fifth secondary winding is connected to the cathode of the fifth diode; the two ends of the fourth capacitor are connected between the cathode of the fourth diode and the non-like-name end of the fourth secondary winding, and the two ends of the fifth capacitor are connected between the like-name end of the fifth secondary winding and the anode of the fifth diode.

[0019] The output networks of the three groups of second secondary winding units are connected to the lower gate drive circuit or the upper gate drive circuit to supply power to the lower three bridges or the upper three bridges in the three-phase (U, V, W) inverter bridge.

[0020] The above-mentioned second PWM controller is connected to the gate of the second transistor, one electrode of the second transistor is connected to the same-name terminal of the second primary winding, the other electrode of the second transistor is connected to the first end of the second resistor, and is also connected to the second PWM controller; the second end of the second resistor is connected to the negative terminal of the low-voltage battery power supply; the non-same-name terminal of the second primary winding is connected to the cathode of the sixth diode, the anode of the sixth diode is connected to the positive terminal of the low-voltage battery power supply; and the two ends of the sixth capacitor are connected between the cathode of the sixth diode and the negative terminal of the low-voltage battery power supply.

[0021] The above-mentioned second multi-winding transformer also includes: a sixth secondary winding, a seventh diode, and a seventh capacitor; wherein the same-name end of the sixth secondary winding is connected to the anode of the seventh diode, and the cathode of the seventh diode is connected to the second PWM controller; the two ends of the seventh capacitor are connected between the cathode of the seventh diode and the non-like-name end of the sixth secondary winding, and the non-like-name end of the sixth secondary winding is connected to the ground end.

[0022] In some possible implementations, each phase of the three-phase inverter bridge includes two transistors connected in series between a positive DC bus and a negative DC bus.

[0023] In some possible implementations, the transistor may be an insulated gate bipolar transistor.

[0024] In some possible implementations, the transistor may be a metal-oxide semiconductor field-effect transistor.

[0025] An embodiment of the present application also provides a car, comprising a motor control system provided in any of the possible implementation methods described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a motor control system provided in an embodiment of the present application;

[0027] Figure 2 A schematic block diagram of a portion of the structure of a motor control system provided in an embodiment of the present application;

[0028] Figure 3 A schematic block diagram of a portion of the structure of a motor control system provided in an embodiment of the present application;

[0029] Figure 4 A schematic block diagram of a portion of the structure of a motor control system provided in an embodiment of the present application;

[0030] Figure 5 A circuit diagram of a high-voltage bus step-down conversion circuit in a motor control system provided in an embodiment of the present application;

[0031] Figure 6A circuit diagram of a low-voltage battery power conversion circuit in a motor control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0033] The terms "first," "second," and the like in the specification, embodiments, claims, and drawings of this application are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order. "Installed," "connected," and "connected" should be understood broadly, for example, to mean fixedly connected, detachably connected, or integrally connected; directly connected, indirectly through an intermediate medium, or internally connected between two components. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions, such as including a series of steps or units. A method, system, product, or apparatus is not necessarily limited to the steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to the process, method, product, or apparatus. "Up," "down," and the like are used only with respect to the orientation of components in the drawings. These directional terms are relative concepts and are used for description and clarification relative to the context. They may change accordingly depending on the orientation of the components in the drawings.

[0034] An embodiment of the present application provides a car, which can be a pure electric car or a hybrid electric car, and the present application does not limit this.

[0035] The automobile provided in the embodiment of the present application is provided with a motor control system, which adopts a redundant backup power supply setting with a simple architecture and low cost. When a fault occurs in the motor control system, even in the event of a single-point power failure, it can still reliably execute an active short circuit of the three phases of the motor to avoid the motor generating unexpected braking torque and avoiding problems such as damage to related components due to backflow of motor energy.

[0036] The motor control system provided in the embodiments of the present application is further described below.

[0037] like Figure 1 As shown, an embodiment of the present application provides a motor control system, which includes: a bus capacitor 1, a motor 2, a control unit 4, and a power supply unit 5.

[0038] The motor 2 is connected to a positive DC bus (+) and a negative DC bus (-) through a three-phase (U, V, W) inverter bridge (31, 32, 33), and the positive DC bus (+) and the negative DC bus (-) are respectively connected to the positive end and the negative end of the bus capacitor 1; each phase inverter bridge includes: an upper bridge arm a connected to the positive DC bus (+) and a lower bridge arm b connected to the negative DC bus (-).

[0039] In some possible implementations, reference is made to Figure 1 As shown, in the above-mentioned three-phase (U, V, W) inverter bridge (31, 32, 33), each phase inverter bridge includes two transistors arranged in series between the positive DC bus (+) and the negative DC bus (-); that is, the upper bridge arm a and the lower bridge arm b in each phase inverter bridge each include a transistor. The transistor can be an insulated gate bipolar transistor (IGBT) or a metal-oxide semiconductor field effect transistor (MOSFET). This application does not impose specific restrictions on this, and it can be set as needed in practice.

[0040] The following embodiments of the present application are all explained by taking the example that each phase inverter bridge includes two IGBTs connected in series (that is, the upper bridge arm a and the lower bridge arm b each include an IGBT); in this case, it can be understood that, in a single-phase inverter bridge, the gate (that is, the gate) of the IGBT in the upper bridge arm a serves as the control end of the upper bridge arm a, and the source (that is, the collector) is connected to the positive DC bus (+); the gate (that is, the gate) of the IGBT in the lower bridge arm b serves as the control end of the lower bridge arm b, and the drain (that is, the emitter) is connected to the negative DC bus (-); the drain (that is, the emitter) of the IGBT in the upper bridge arm a and the source (that is, the collector) of the IGBT in the lower bridge arm b are connected to the motor 2.

[0041] On this basis, reference Figure 1 As shown, the control unit 4 includes an upper gate drive circuit 41 and a lower gate drive circuit 42 ; the power supply unit 5 includes a first power supply unit 51 and a second power supply unit 52 .

[0042] The first power supply unit 51 is connected to the three upper bridge arms a (also referred to as the upper three bridges) in the three-phase inverter bridge through the upper gate drive circuit 41; in this case, the first power supply unit 52 supplies power to the IGBTs in the upper three bridges through the upper gate drive circuit 41 to achieve three-phase active short circuit of the motor 2.

[0043] The second power supply unit 52 is connected to the three lower bridge arms b (also referred to as the lower three bridges) in the three-phase inverter bridge through the lower gate drive circuit 42 ; in this case, the second power supply unit 52 supplies power to the IGBTs in the lower three bridges through the lower gate drive circuit 42 .

[0044] To sum up, in the motor control system provided in the embodiment of the present application, the first power supply unit 51 and the second power supply unit 52 are used to supply power to the three upper bridge arms a and the three lower bridge arms b in the three-phase inverter bridge (31, 32, 33) through the upper gate drive circuit 41 and the lower gate drive circuit 42 respectively, so that the three upper bridge arms a in the three-phase inverter bridge (31, 32, 33) can be controlled by the upper gate drive circuit 41 to realize the three-phase active short circuit of the motor 2, and the three lower bridge arms b in the three-phase inverter bridge (31, 32, 33) can be controlled by the lower gate drive circuit 42 to realize the three-phase active short circuit of the motor 2; in this case, even if one of the first power supply unit 51 and the second power supply unit 52 fails, the other power supply unit can still normally perform the three-phase active short circuit of the motor 2.

[0045] That is to say, the motor control system provided in the present application, by respectively setting independent gate drive circuits and power supply units for the three upper bridge arms and the three lower bridge arms in the three-phase inverter bridge, on the one hand, can reduce the cost of the control system while ensuring that the entire control system has a simple architecture; on the other hand, even in the event of a failure of a single power supply unit (i.e., a single-point failure of the power supply), the three-phase active short circuit of the motor can still be reliably executed through another set of power supply units and gate drive circuits, thereby meeting the functional safety requirements of the motor control system.

[0046] The specific configuration of the first power supply unit 51 and the second power supply unit 52 will be further described below.

[0047] Among some possible implementations, Figure 2 As shown, the first power supply unit 51 includes a first power conversion unit 11 and a first power supply 21; wherein, the input end of the first power conversion unit 11 is connected to the first power supply 21, and the output end of the first power conversion unit 11 is connected to the upper gate drive circuit 41; in this case, the power output by the first power supply 21 is adjusted by the first power conversion unit 11 and output to the upper gate drive circuit 41, and power is supplied to the IGBT in the upper three bridges through the upper gate drive circuit 41.

[0048] Among some possible implementations, Figure 2As shown, the second power supply unit 52 includes a second power conversion unit 12 and a second power supply 22; wherein, the input end of the second power conversion unit 12 is connected to the second power supply 22, and the output end of the second power conversion unit 12 is connected to the lower gate drive circuit 42; in this case, the power output by the second power supply 22 is adjusted by the second power conversion unit 12 and output to the lower gate drive circuit 42, and power is supplied to the IGBTs in the lower three bridges through the lower gate drive circuit 42.

[0049] This application does not impose any specific restrictions on the configuration of the first power conversion unit 11 and the first power supply 21 in the above-mentioned first power supply unit 51, and the configuration of the second power conversion unit 12 and the second power supply 22 in the second power supply unit 52. In practice, they can be configured as needed.

[0050] For example, Figure 3 As shown, in some possible implementations, in the first power supply unit 51, the first power supply 21 can use the aforementioned bus capacitor 1, and the first power conversion unit 11 can use a high-voltage bus step-down conversion circuit A. In this case, the high-voltage bus step-down conversion circuit A is connected to the positive and negative terminals of the bus capacitor 1 via a positive DC bus (+) and a negative DC bus (-). In the second power supply unit 52, the second power supply 22 can use a low-voltage battery power supply D, for example, a 12V battery power supply; and the second power conversion unit 12 can use a low-voltage battery power conversion circuit B.

[0051] For example, Figure 4 As shown, in some possible implementations, in the first power supply unit 51, the first power supply 21 can use a low-voltage battery power supply D, for example, a 12V battery power supply; the first power conversion unit 11 can use a low-voltage battery power conversion circuit B. In the second power supply unit 52, the second power supply 22 can use the aforementioned bus capacitor 1, and the second power conversion unit 12 can use a high-voltage bus step-down conversion circuit A. In this case, the high-voltage bus step-down conversion circuit A is connected to the positive and negative terminals of the bus capacitor 1 via the positive DC bus (+) and the negative DC bus (-).

[0052] Regarding the above Figure 3 and Figure 4In the implementation shown in the figure, the first power supply 21 and the second power supply 22, one uses a low-voltage battery power supply D and the other uses a bus capacitor 1. The corresponding first power conversion unit 11 and the second power conversion unit 12, one uses a high-voltage bus buck conversion circuit A and the other uses a low-voltage battery power conversion circuit B; the present application does not limit the specific setting method of the high-voltage bus buck conversion circuit A and the low-voltage battery power conversion circuit B, and in practice they can be set as needed; for illustration, the following provides a specific setting structure of the high-voltage bus buck conversion circuit A and the low-voltage battery power conversion circuit B.

[0053] For the high-voltage bus step-down conversion circuit A:

[0054] Among some possible implementations, Figure 5 As shown, the high-voltage bus step-down conversion circuit A may include: a PWM (pulse width modulation) controller 10 (also referred to as a first PWM controller) and a multi-winding transformer T100 (also referred to as a first multi-winding transformer). The multi-winding transformer T100 includes a primary winding P1 (also referred to as a first primary winding P1) and three sets of secondary winding units A1, A2, and A3 (also referred to as three sets of first secondary winding units).

[0055] refer to Figure 5 As shown, the above-mentioned PWM controller 10 is connected to the gate of the transistor M1 (also referred to as the first transistor), one electrode (source or drain) of the transistor M1 is connected to the same-name terminal (*) of the primary winding P1, and the other electrode (drain or source) of the transistor M1 is connected to the first end of the resistor R1 (also referred to as the first resistor) and is connected to the PWM controller 10; the second end of the resistor R1 is connected to the negative end of the bus capacitor 1 through the negative DC bus (-); the non-same-name terminal of the primary winding P1 is connected to the positive end of the bus capacitor 1 through the positive DC bus (+).

[0056] refer to Figure 5As shown, the secondary winding unit A1 includes a secondary winding S11, a secondary winding S21, a capacitor C11, a capacitor C21, a diode D11, and a diode D21. The non-coinciding end of the secondary winding S11 is connected to the coinciding end (*) of the secondary winding S21 and is connected to the negative end of the bus capacitor 1 via the negative DC bus (-). The coinciding end (*) of the secondary winding S11 is connected to the anode of the diode D11, and the non-coinciding end of the secondary winding S21 is connected to the cathode of the diode D21. The two ends of the capacitor C11 are connected between the cathode of the diode D11 and the non-coinciding end of the secondary winding S11. The two ends of the capacitor C21 are connected between the anode of the diode D21 and the coinciding end (*) of the secondary winding S21. The cathode of the diode D11 is connected to the PWM controller 10.

[0057] In addition, the three output networks of the secondary winding unit A1 (such as 16V_U2, GND_U2, -8V_U2) are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (U) in the three-phase inverter bridge; or, the three output networks of the secondary winding unit A1 (such as 16V_U2, GND_U2, -8V_U2) are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (U) in the three-phase inverter bridge.

[0058] refer to Figure 5 As shown, the secondary winding unit A2 includes a secondary winding S12, a secondary winding S22, a capacitor C12, a capacitor C22, a diode D12, and a diode D22. The non-identical end of the secondary winding S12 is connected to the identical end (*) of the secondary winding S22; the identical end (*) of the secondary winding S11 is connected to the anode of the diode D12, and the non-identical end of the secondary winding S22 is connected to the cathode of the diode D22; the two ends of the capacitor C12 are connected between the cathode of the diode D12 and the non-identical end of the secondary winding S12; and the two ends of the capacitor C22 are connected between the anode of the diode D22 and the identical end (*) of the secondary winding S22.

[0059] In addition, the three output networks of the secondary winding unit A2 (such as 16V_V2, GND_V2, -8V_V2) are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (V) in the three-phase inverter bridge; or, the three output networks of the secondary winding unit A2 (such as 16V_V2, GND_V2, -8V_V2) are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (V) in the three-phase inverter bridge.

[0060] refer to Figure 5As shown, the secondary winding unit A3 includes a secondary winding S13, a secondary winding S23, a capacitor C13, a capacitor C23, a diode D13, and a diode D23. The non-identical end of the secondary winding S13 is connected to the identical end (*) of the secondary winding S23; the identical end (*) of the secondary winding S13 is connected to the anode of the diode D13, and the non-identical end of the secondary winding S23 is connected to the cathode of the diode D23; the two ends of the capacitor C13 are connected between the cathode of the diode D13 and the non-identical end of the secondary winding S13; and the two ends of the capacitor C23 are connected between the anode of the diode D23 and the identical end (*) of the secondary winding S23.

[0061] In addition, the three output networks of the secondary winding unit A3 (such as 16V_W2, GND_W2, and -8V_W2) are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (W) in the three-phase inverter bridge; or, the three output networks of the secondary winding unit A3 (such as 16V_W2, GND_W2, and -8V_W2) are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (W) in the three-phase inverter bridge.

[0062] On this basis, in some possible implementation methods, the multi-winding transformer T100 in the high-voltage bus step-down conversion circuit A can also include a secondary winding S3, a diode D3, and a capacitor C3; wherein, the same-name end (*) of the secondary winding S3 is connected to the anode of the diode D3, and the non-same-name end of the secondary winding S3 is connected to the ground terminal GND; the two ends of the capacitor D3 are connected to the cathode of the diode D3 and the non-same-name end of the secondary winding S3; the two output networks of the secondary winding S3 (such as +16V and GND ends) can be connected to the upper gate drive circuit 41 or the lower gate drive circuit 42 to power the isolation drive chip in the upper gate drive circuit 41 or the lower gate drive circuit 42, so as to output control signals to the IGBT in the three-phase inverter bridge through the isolation drive chip.

[0063] In this case, the PWM controller 10 outputs a PWM signal to the transistor M1 to control the on and off of the transistor M1; the resistor R1 feeds back the collected current signal to the PWM controller 10, so that when an electrical signal is provided to the primary winding P1 through the bus capacitor 1, a voltage is induced in the secondary windings of the three groups of secondary winding units A1, A2, and A3, and power is provided to the IGBTs in the upper three bridges or the lower three bridges through the upper gate drive circuit 41 or the lower gate drive circuit 42.

[0064] For the low-voltage battery power conversion circuit B:

[0065] like Figure 6As shown, in some possible implementations, the low-voltage battery power conversion circuit B may include a PWM controller 20 (also referred to as a second PWM controller) and a multi-winding transformer T200 (also referred to as a second multi-winding transformer). The multi-winding transformer T200 includes a primary winding P2 (also referred to as a second primary winding) and three groups of secondary winding units B1, B2, and B3 (also referred to as three groups of second secondary winding units).

[0066] refer to Figure 6 As shown, the secondary winding unit B1 includes a secondary winding S41, a secondary winding S51, a diode D41, a diode D51, a capacitor C41, and a capacitor C51. The non-identical end of the secondary winding S41 is connected to the identical end (*) of the secondary winding S51 and to the ground terminal GND; the identical end (*) of the secondary winding S41 is connected to the anode of the diode D41; the non-identical end of the secondary winding S51 is connected to the cathode of the diode D51; the two ends of the capacitor C41 are connected between the cathode of the diode D41 and the non-identical end of the secondary winding S41; and the two ends of the capacitor C51 are connected between the identical end (*) of the secondary winding S51 and the anode of the diode D51.

[0067] In addition, the three output networks of the secondary winding unit B1 (such as 16V_U1, GND_U1, -8V_U1) are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (U) in the three-phase inverter bridge; or, the three output networks of the secondary winding unit B1 (such as 16V_U1, GND_U1, -8V_U1) are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (U) in the three-phase inverter bridge.

[0068] refer to Figure 6 As shown, the secondary winding unit B2 includes a secondary winding S42, a secondary winding S52, a diode D42, a diode D52, a capacitor C42, and a capacitor C52. The non-identical end of the secondary winding S42 is connected to the identical end (*) of the secondary winding S52 and to the ground terminal GND; the identical end (*) of the secondary winding S42 is connected to the anode of the diode D42; the non-identical end of the secondary winding S52 is connected to the cathode of the diode D52; the two ends of the capacitor C42 are connected between the cathode of the diode D42 and the non-identical end of the secondary winding S42; and the two ends of the capacitor C52 are connected between the identical end (*) of the secondary winding S52 and the anode of the diode D52.

[0069] In addition, the three output networks (such as 16V_V1, GND_V1, -8V_V1) of the secondary winding unit B2 are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (V) in the three-phase inverter bridge; or, the three output networks (such as 16V_V1, GND_V1, -8V_V1) of the secondary winding unit B2 are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (V) in the three-phase inverter bridge.

[0070] refer to Figure 6 As shown, the secondary winding unit B3 includes a secondary winding S43, a secondary winding S53, a diode D43, a diode D53, a capacitor C43, and a capacitor C53. The non-identical end of the secondary winding S43 is connected to the identical end (*) of the secondary winding S53 and to the ground terminal GND; the identical end (*) of the secondary winding S43 is connected to the anode of the diode D43; the non-identical end of the secondary winding S53 is connected to the cathode of the diode D53; the two ends of the capacitor C43 are connected between the cathode of the diode D43 and the non-identical end of the secondary winding S43; and the two ends of the capacitor C53 are connected between the identical end (*) of the secondary winding S53 and the anode of the diode D53.

[0071] In addition, the three output networks of the secondary winding unit B3 (such as 16V_W1, GND_W1, -8V_W1) are connected to the lower gate drive circuit 42 to supply power to the IGBT of the lower bridge in one phase inverter bridge (W) in the three-phase inverter bridge; or, the three output networks of the secondary winding unit B3 (such as 16V_W1, GND_W1, -8V_W1) are connected to the upper gate drive circuit 41 to supply power to the IGBT of the upper bridge in one phase inverter bridge (W) in the three-phase inverter bridge.

[0072] refer to Figure 6 As shown, the above-mentioned PWM controller 20 is connected to the gate of the transistor M2, one electrode (source or drain) of the transistor M2 is connected to the same-name terminal (*) of the primary winding P2, and the other electrode (drain or source) of the transistor M2 is connected to the first end of the resistor R2 and is also connected to the PWM controller 20; the second end of the resistor R2 is connected to the negative end of the low-voltage battery power source D; the non-same-name end of the primary winding P2 is connected to the cathode of the diode D6, and the anode of the diode D6 is connected to the positive end of the low-voltage battery power source D; the two ends of the capacitor C6 are connected between the cathode of the diode D6 and the negative end of the low-voltage battery power source D; schematically, the negative end of the low-voltage battery power source D can be connected to the ground terminal GND.

[0073] In this case, the PWM controller 20 outputs a PWM signal to the gate of the transistor M2 to control the on and off of the transistor M2; the resistor R2 feeds back the collected current signal to the PWM controller 10, so that when an electrical signal is provided to the primary winding P2 through the low-voltage battery power supply D, a voltage is induced in the secondary windings of the three groups of secondary winding units B1, B2, and B3, and power is provided to the IGBTs in the lower three bridges or the upper three bridges through the lower gate drive circuit 42 or the upper gate drive circuit 41.

[0074] In addition, in the low-voltage battery power conversion circuit B, the multi-winding transformer T200 further includes: a secondary winding S6, a diode D7, and a capacitor C7. The same-name terminal (*) of the secondary winding S6 is connected to the anode of the diode D7, and the cathode of the diode D7 is connected to the PWM controller 20. The two ends of the capacitor C7 are connected between the cathode of the diode D7 and the non-same-name terminal of the secondary winding S6, and the non-same-name terminal of the secondary winding S6 is connected to the ground terminal GND. In this case, the secondary winding S6 serves as the feedback winding of the transformer, achieving a closed-loop voltage feedback function.

[0075] It should be noted here that the aforementioned embodiment is only a schematic illustration of the process in which the first power supply unit 51 and the second power supply unit 52 respectively supply power to the IGBTs in the three-phase inverter bridge (31, 32, 33) through the gate drive circuit 41 and the lower gate drive circuit 42 in this application to realize the three-phase active short circuit of the motor 2; those skilled in the art should understand that in this motor control system, during the normal operation of the motor 2, the first power supply unit 51 and the second power supply unit 52 supply power to the IGBTs in the three-phase inverter bridge (31, 32, 33) through the gate drive circuit 41 and the lower gate drive circuit 42, so that the bus capacitor 1 supplies power to the motor 2 to realize the normal operation of the motor 2.

[0076] It can also be understood that in the motor control system provided in the embodiment of the present application, the bus capacitor 1 can absorb the voltage spike stress of the IGBT in the inverter bridge, and when the motor 2 is working, the bus capacitor 1 can also reduce the voltage ripple of the DC bus.

[0077] In addition, it should be noted that the motor control system provided in the aforementioned embodiments of the present application is not limited to application in the automotive field, but can be applied to any other applicable fields, such as servo, inverter and other industrial control fields.

[0078] 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 control system, characterized in that: The motor control system includes a motor, a bus capacitor, an upper gate drive circuit, a lower gate drive circuit, a high-voltage bus step-down conversion circuit, and a low-voltage battery power conversion circuit. The three-phase windings of the motor are respectively used to connect to the midpoints of the three bridge arms of the three-phase inverter bridge. Each phase inverter bridge includes an upper bridge arm connected to the positive DC bus and a lower bridge arm connected to the negative DC bus. The positive DC bus and the negative DC bus are respectively connected to the positive end and the negative end of the bus capacitor. The upper gate drive circuit is used to drive the three upper bridge arms of the three-phase inverter bridge. The lower gate drive circuit is used to drive the three lower bridge arms of the three-phase inverter bridge. The high-voltage bus step-down conversion circuit is used to receive power from the bus capacitor and supply power to one of the upper gate drive circuit and the lower gate drive circuit. The low-voltage battery power conversion circuit is used to receive power from the low-voltage battery and supply power to the other of the upper gate drive circuit and the lower gate drive circuit. The high-voltage bus step-down conversion circuit includes a first multi-winding transformer, which includes a first primary winding, three first secondary winding units, and a third secondary winding. The output networks of the three groups of first secondary winding units are connected to the upper gate drive circuit or the lower gate drive circuit to supply power to the three upper bridge arms or lower bridge arms of the three-phase inverter bridge. The output network of the third secondary winding is used to supply power to the isolation driver chip in the upper gate drive circuit or the lower gate drive circuit.

2. The motor control system according to claim 1, characterized in that: The first multi-winding transformer also includes a third diode and a third capacitor. The same-name end of the third secondary winding is connected to the anode of the third diode, the non-like-name end of the third secondary winding is connected to the ground end, and the two ends of the third capacitor are connected between the cathode of the third diode and the non-like-name end of the third secondary winding.

3. The motor control system according to claim 1, characterized in that: The high-voltage bus step-down conversion circuit also includes a first PWM controller, which is connected to the gate of a first transistor, one electrode of the first transistor is connected to the same-name end of the first primary winding, the other electrode of the first transistor is connected to the first end of a first resistor and is connected to the first PWM controller, the second end of the first resistor is connected to the negative end of the bus capacitor through the negative DC bus, and the non-same-name end of the first primary winding is connected to the positive end of the bus capacitor through the positive DC bus.

4. The motor control system according to claim 1, characterized in that: Each of the three first secondary winding units includes a first secondary winding, a second secondary winding, a first capacitor, a second capacitor, a first diode, and a second diode; The non-like-named ends of the first secondary winding are connected to the like-named ends of the second secondary winding; the like-named ends of the first secondary winding are connected to the anode of the first diode, and the non-like-named ends of the second secondary winding are connected to the cathode of the second diode. The two ends of the first capacitor are connected between the cathode of the first diode and the non-like-named ends of the first secondary winding, and the two ends of the second capacitor are connected between the anode of the second diode and the like-named ends of the second secondary winding.

5. The motor control system according to any one of claims 1 to 4, characterized in that: In the process of the bus capacitor being used to supply power to the high-voltage bus step-down conversion circuit: The first PWM controller is used to output a PWM signal to the first transistor to control the opening and closing of the first transistor. The first resistor feeds back the collected current signal to the first PWM controller, so that when the electrical signal is provided to the primary winding through the bus capacitor, the secondary windings in the three groups of secondary winding units supply power to the upper gate drive circuit or the lower gate drive circuit.

6. The motor control system according to any one of claims 1 to 5, characterized in that: The low-voltage battery power conversion circuit includes a second PWM controller and a second multi-winding transformer. The second multi-winding transformer includes a second primary winding and three groups of second secondary winding units. The second secondary winding units include a fourth secondary winding, a fifth secondary winding, a fourth diode, a fifth diode, a fourth capacitor, and a fifth capacitor. The non-identical end of the fourth secondary winding is connected to the identical end of the fifth secondary winding and to the ground end. The identical end of the fourth secondary winding is connected to the anode of the fourth diode; the non-identical end of the fifth secondary winding is connected to the cathode of the fifth diode. The two ends of the fourth capacitor are connected between the cathode of the fourth diode and the non-identical end of the fourth secondary winding. The two ends of the fifth capacitor are connected between the identical end of the fifth secondary winding and the anode of the fifth diode. The output networks of the three groups of second secondary winding units are connected to the lower gate drive circuit or the upper gate drive circuit.

7. The motor control system according to claim 6, characterized in that: The second PWM controller is connected to the gate of the second transistor, one electrode of the second transistor is connected to the same-name end of the second primary winding, the other electrode of the second transistor is connected to the first end of the second resistor and is connected to the second PWM controller, the second end of the second resistor is connected to the negative end of the low-voltage battery power supply, the non-same-name end of the second primary winding is connected to the cathode of the sixth diode, the anode of the sixth diode is connected to the positive end of the low-voltage battery power supply, and the two ends of the sixth capacitor are connected between the cathode of the sixth diode and the negative end of the low-voltage battery power supply.

8. The motor control system according to claim 6 or 7, characterized in that: The second multi-winding transformer also includes a sixth secondary winding, a seventh diode, and a seventh capacitor. The same-name end of the sixth secondary winding is connected to the anode of the seventh diode, the cathode of the seventh diode is connected to the second PWM controller, and the two ends of the seventh capacitor are connected between the cathode of the seventh diode and the non-like-name end of the sixth secondary winding, and the non-like-name end of the sixth secondary winding is connected to the ground end.

9. The motor control system according to any one of claims 1 to 8, characterized in that: When one of the high-voltage bus step-down conversion circuit and the low-voltage battery power conversion circuit fails, the motor control system is used to control the other one of the high-voltage bus step-down conversion circuit and the low-voltage battery power conversion circuit to perform active short-circuiting of the motor three phases.

10. An automobile, characterized in that: The motor control system includes any one of claims 1 to 9.

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