Control method of drive circuit of motor, motor, drive circuit, and electronic device

Abstract

This invention provides a control method for a motor drive circuit, a motor, and a drive circuit. The control method controls the motor drive circuit, where each phase winding of the multiphase winding is connected to two switches in a corresponding bridge arm. When one switch experiences a short-circuit fault, the other switch in that bridge arm is controlled to open, preventing both switches in that bridge arm from conducting simultaneously. When one switch experiences an open-circuit fault, the other switch in that bridge arm is controlled to close, ensuring that current can flow through that bridge arm. This invention achieves this by controlling the opening and closing of two switches in each of the other unfaulted bridge arms and controlling at least one of the other unfaulted bridge arms to form a power circuit with the faulty bridge arm, ensuring that current flows through each bridge arm and its corresponding winding, and generating a rotating magnetic field in the multiple windings to assist the motor.

Description

Technical Field

[0001] This invention belongs to the field of drive device technology, and specifically relates to a control method for a motor drive circuit, a motor, a drive circuit, and electronic equipment. Background Technology

[0002] The inverter is a key component of the drive motor windings. By changing parameters such as the frequency, voltage, and phase of the output AC power, the inverter controls the magnitude and direction of the current in the motor windings, thereby enabling the motor to run at the desired speed, torque, and direction.

[0003] The inverter's drive circuit mainly includes a control signal input unit, a power amplifier unit (i.e., a switch), a protection unit, and a power supply unit. Among these, the power amplifier unit is the core component of the drive circuit. Since there are many power amplifier units involved in the inverter, it is inevitable that some components will fail (short circuit or open circuit) during operation. In the existing technology, in order to avoid circuit failure caused by the failure of a certain component of the inverter, the common method used for protection circuits is to cut off the current of the entire circuit. However, after cutting off the current of the entire circuit, the drive circuit cannot provide assistance to the motor.

[0004] In existing technologies, to ensure the drive circuit continues to operate even when individual components fail, all other components in the same phase as the faulty component are shut off, preventing current from flowing through that phase and thus protecting the circuit. For example, patent CN109075735A discloses a power conversion device, a motor drive unit, and an electric power steering device. This patent, upon detecting a switching element failure, changes the inverter control from n-phase energization to m-phase energization (m < n). Taking a three-phase circuit as an example, when a component in the inverter fails, all other components connected in the same phase are shut off, preventing current from flowing through that phase. The components in the remaining two unfaulted phases are then used to energize the other two phases. However, the control principle of this method is based on phase loss protection. Completely cutting off the current to the faulty phase can lead to magnetic field distortion, excessive temperature, and large current and voltage fluctuations, potentially damaging the motor in severe cases. Summary of the Invention

[0005] The purpose of this invention is to solve the problem in the control method of the phase loss protection circuit in the prior art, which completely cuts off the current of the phase that has failed, which may lead to magnetic field distortion, excessive temperature, large current and voltage fluctuations, and in severe cases, damage to the motor.

[0006] To solve the above-mentioned technical problems, the present invention discloses a control method for a motor drive circuit, which is used to control the motor drive circuit. The drive circuit includes a power supply and multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series, one of which is directly connected to the positive terminal of the power supply and the other is directly connected to the negative terminal of the power supply. The motor includes a multi-phase winding, one end of each phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between the two switches of the corresponding bridge arm.

[0007] The control method includes the following steps: When a switch experiences a short-circuit fault, the bridge arm containing the short-circuit fault is determined to have a first fault. The other switch in the bridge arm with the first fault is controlled to open, and in each of the other bridge arms without the first fault, one switch is turned on and the other is turned off. Furthermore, at least one of the other bridge arms without the first fault forms a power supply loop with the bridge arm with the first fault. Alternatively, when a switch experiences an open-circuit fault, the bridge arm containing the open-circuit fault is determined to have a second fault. The other switch in the bridge arm with the second fault is controlled to turn on, and in each of the other bridge arms without the second fault, one switch is turned on and the other is turned off. Furthermore, at least one of the other bridge arms without the second fault forms a power supply loop with the bridge arm with the second fault.

[0008] Using the above technical solution, the direction of current is changed by controlling the on / off state of each switch in each bridge arm of the drive circuit. Since one end of each phase winding of the multi-phase winding is connected to the neutral point, current can flow between the multi-phase windings; the other end of each phase winding has a phase line connected to the two switches of the corresponding bridge arm, with one switch directly connected to the positive terminal of the power supply and the other directly connected to the negative terminal. Therefore, each phase winding can be connected to either the positive or negative terminal of the power supply by connecting to any switch in the corresponding bridge arm. When a switch in the drive circuit experiences a short circuit or open circuit fault, corresponding control measures need to be taken for the other switches to protect the circuit.

[0009] Specifically, when a switch experiences a short-circuit fault, the faulty switch is essentially in a conducting state. Therefore, the bridge arm containing the faulty switch is considered to have experienced a first fault. By controlling the other switch in that bridge arm to open, the simultaneous conduction of both switches in that bridge arm with the positive and negative terminals of the power supply is prevented. By controlling the two switches in each of the other bridge arms that have not experienced a first fault, one is conducting and the other is open. This prevents both switches in each of the non-faulty bridge arms from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other non-faulty bridge arms to form a power circuit with the faulty bridge arm, the current generates a rotating magnetic field in multiple windings, thus providing assistance to the motor.

[0010] When a switch experiences an open-circuit fault, it is determined that the bridge arm containing the faulty switch has a second fault. By controlling the other switch in that bridge arm to conduct, current can be ensured to flow through the bridge arm with the second fault. By controlling the two switches in each of the other bridge arms that have not experienced a second fault, one is conducting and the other is open. This prevents both switches in each of the bridge arms that have not experienced a second fault from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through each bridge arm and each winding corresponding to each bridge arm, avoiding faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other bridge arms that have not experienced a second fault to form a power circuit with the bridge arm that has experienced a second fault, the current generates a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0011] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a control method for a motor drive circuit. When the switch in the bridge arm where the first fault occurs is a switch directly connected to the positive terminal of the power supply, the other switch in the bridge arm where the first fault occurs is controlled to be disconnected, and the two switches in each of the other bridge arms where the first fault does not occur are controlled so that one is turned on and the other is turned off; wherein, in at least one of the other bridge arms where the first fault does not occur, the switch that is turned on is a switch directly connected to the negative terminal of the power supply.

[0012] Using the above technical solution, when the switch in the bridge arm experiencing the first fault is directly connected to the positive terminal of the power supply, the switch experiencing the short circuit fault is equivalent to being directly connected to the positive terminal of the power supply. The other switch in the same bridge arm is directly connected to the negative terminal of the power supply. By controlling the other switch in the same bridge arm to disconnect, it is possible to prevent both switches in the same bridge arm from simultaneously conducting and forming a closed loop with the positive and negative terminals of the power supply. Since at least one switch in the other bridge arms that did not experience the first fault is directly connected to the negative terminal of the power supply, the current from the positive terminal of the power supply can flow through the switch experiencing the short circuit fault to the corresponding winding, and then through the neutral point to the switch in the bridge arm that did not experience the first fault and is directly connected to the negative terminal of the power supply, thus forming a power supply loop. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0013] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a control method for a motor drive circuit. When the switch in a bridge arm that has a short circuit fault is a switch directly connected to the negative terminal of the power supply, the other switch in the bridge arm that has the first fault is controlled to be disconnected, and the two switches in each of the other bridge arms that have not experienced the first fault are controlled so that one is turned on and the other is turned off; wherein, in at least one of the other bridge arms that have not experienced the first fault, the switch that is turned on is a switch directly connected to the positive terminal of the power supply.

[0014] Using the above technical solution, when the switch in the bridge arm experiencing the first fault is directly connected to the negative terminal of the power supply, the switch experiencing the short circuit fault is equivalent to being directly connected to the negative terminal of the power supply. The other switch in the same bridge arm is directly connected to the positive terminal of the power supply. By controlling the other switch in the same bridge arm to disconnect, it is possible to prevent both switches in the same bridge arm from simultaneously conducting and forming a closed loop with the positive and negative terminals of the power supply. Since at least one switch in the other bridge arms that did not experience the first fault is directly connected to the positive terminal of the power supply, the current from the positive terminal of the power supply can flow through the switch in the bridge arm that did not experience the first fault and is directly connected to the positive terminal of the power supply to the corresponding winding, and then through the neutral point to the switch experiencing the short circuit fault, thus forming a power supply loop. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0015] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a control method for a motor drive circuit. When the switch in the bridge arm where the second fault occurs is a switch directly connected to the positive terminal of the power supply, the other switch in the bridge arm is controlled to be turned on, and the two switches in each other bridge arm where the second fault does not occur are controlled so that one is turned on and the other is turned off; wherein, in at least one of the other bridge arms where the second fault does not occur, the switch that is turned on is a switch directly connected to the positive terminal of the power supply.

[0016] Using the above technical solution, when the switch in the bridge arm experiencing the second fault is directly connected to the positive terminal of the power supply, and the other switch in that bridge arm is directly connected to the negative terminal of the power supply, controlling the other switch in that bridge arm to conduct ensures that current can flow through the bridge arm experiencing the second fault. Since at least one of the other bridge arms that did not experience the second fault has a switch directly connected to the positive terminal of the power supply, current from the positive terminal of the power supply can flow through the switch in the bridge arm that did not experience the second fault to the corresponding winding, and then through the neutral point to the switch in the bridge arm experiencing the second fault that is connected to the negative terminal of the power supply, thus forming a power circuit. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0017] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a control method for a motor drive circuit. When the switch in the bridge arm where the second fault occurs is a switch directly connected to the negative terminal of the power supply, the other switch in that bridge arm is controlled to be turned on, and the two switches in each of the remaining bridge arms where the second fault has not occurred are controlled so that one is turned on and the other is turned off; wherein, in at least one of the other bridge arms where the second fault has not occurred, the switch that is turned on is a switch directly connected to the negative terminal of the power supply.

[0018] Using the above technical solution, when the switch in the bridge arm experiencing the second fault is directly connected to the negative terminal of the power supply, and the other switch in that bridge arm is directly connected to the positive terminal of the power supply, controlling the other switch in that bridge arm to conduct ensures that current can flow through the bridge arm experiencing the second fault. Since at least one of the other bridge arms that did not experience the second fault has a switch directly connected to the negative terminal of the power supply, current from the positive terminal of the power supply can flow through the switch in the bridge arm experiencing the second fault to the corresponding winding, and then through the neutral point to the switch in the bridge arm that did not experience the second fault and is directly connected to the negative terminal of the power supply, thus forming a power circuit. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0019] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a control method for a motor drive circuit. The control method is used to control the drive circuit, which includes three bridge arms arranged in parallel with the power supply. The motor includes a three-phase winding, and the drive circuit is connected to the three-phase winding of the motor for driving the motor. In this embodiment, one end of each phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between two switches of the corresponding bridge arm.

[0020] According to another specific embodiment of the present invention, an electric motor is disclosed. The drive circuit of the electric motor includes a power supply and multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series, one of which is directly connected to the positive terminal of the power supply and the other is directly connected to the negative terminal of the power supply. The drive circuit of the electric motor is controlled by a control method for the drive circuit of the electric motor. The electric motor includes a multi-phase winding, which is a three-phase winding. One end of each phase winding in the three-phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between the two switches of the corresponding bridge arm in the drive circuit.

[0021] According to another specific embodiment of the present invention, a driving circuit is disclosed. The driving circuit includes a power supply and a plurality of bridge arms arranged in parallel with the power supply. Each bridge arm includes two switches connected in series. One of the two switches in each bridge arm is directly connected to the positive terminal of the power supply, and the other is directly connected to the negative terminal of the power supply. The driving circuit is controlled using a control method for a motor driving circuit.

[0022] According to another specific embodiment of the present invention, a driving circuit is disclosed, which further includes a capacitor connected in parallel with the power supply and a resistor connected in series with the capacitor.

[0023] According to another specific embodiment of the present invention, an electronic device is disclosed, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement a method for controlling a motor drive circuit.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention provides a control method for a motor drive circuit, a motor, and a drive circuit. The control method is used to control the motor drive circuit. The drive circuit includes a power supply and multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series, with one switch directly connected to the positive terminal of the power supply and the other directly connected to the negative terminal. The motor includes multi-phase windings, with one end of each phase winding connected to the neutral point and the other end having a phase line connected to the two switches of the corresponding bridge arm. When a short circuit or open circuit fault occurs in one of the switches in the drive circuit, corresponding control measures need to be taken for the other switches to protect the circuit.

[0026] When a switch experiences a short-circuit fault, the bridge arm containing that switch is considered to have a first fault. By controlling the other switch in that bridge arm to open, the simultaneous conduction of both switches in that bridge arm with the positive and negative terminals of the power supply is prevented from forming a closed loop. When a switch experiences an open-circuit fault, the bridge arm containing that switch is considered to have a second fault. By controlling the other switch in that bridge arm to close, current can flow through the bridge arm with the second fault. By controlling the two switches in each of the other unfaulted bridge arms so that one is closed and the other is open, it is possible to prevent both switches in each unfaulted bridge arm from simultaneously conducting and forming a closed loop with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other unfaulted bridge arms to form a power circuit with the faulty bridge arm, the current generates a rotating magnetic field in multiple windings, thus providing assistance to the motor. Attached Figure Description

[0027] Figure 1 A circuit diagram showing the short-circuit loop formed when switch a in the drive circuit experiences a short-circuit fault;

[0028] Figure 2 A schematic diagram of the drive circuit with a phase line separator in the prior art;

[0029] Figure 3 When a short circuit fault occurs in switch A, a circuit diagram (state 100) of a specific implementation of the control method for the motor drive circuit provided in Embodiment 4 of the present invention is shown.

[0030] Figure 4 When a short circuit fault occurs in switch A, a circuit diagram (state 101) of another specific implementation of the control method for the motor drive circuit provided in Embodiment 4 of the present invention is shown.

[0031] Figure 5 When a short circuit fault occurs in switch A, a circuit diagram (state 110) of another specific implementation of the control method for the motor drive circuit provided in Embodiment 4 of the present invention is shown.

[0032] Figure 6 This is a circuit diagram (state 111) showing that the drive circuit cannot provide assistance to the motor when a short circuit fault occurs in switch A.

[0033] Figure 7 A circuit diagram showing that the drive circuit cannot provide assistance to the motor when a short circuit fault occurs at switch b (state 000);

[0034] Figure 8A circuit diagram (state 001) of a specific implementation of the control method for the motor drive circuit provided in Embodiment 5 of the present invention when a short circuit fault occurs in switch b;

[0035] Figure 9 When a short circuit fault occurs in switch b, a circuit diagram (state 100) of another specific implementation of the control method for the motor drive circuit provided in Embodiment 5 of the present invention is shown.

[0036] Figure 10 When a short circuit fault occurs in switch b, a circuit diagram (state 101) of another specific implementation of the control method for the motor drive circuit provided in Embodiment 5 of the present invention is shown.

[0037] Figure 11 A circuit diagram showing that the drive circuit cannot provide assistance to the motor when switch A experiences an open circuit fault (state 000).

[0038] Figure 12 When a circuit failure occurs in switch A, a circuit diagram (state 001) of a specific implementation of the control method for the motor drive circuit provided in Embodiment 6 of the present invention is shown.

[0039] Figure 13 When a circuit failure occurs in switch A, a circuit diagram (state 010) of another specific implementation of the motor drive circuit control method provided in Embodiment 6 of the present invention is shown.

[0040] Figure 14 When a circuit failure occurs in switch A, a circuit diagram (state 011) of another specific implementation of the motor drive circuit control method provided in Embodiment 6 of the present invention is shown.

[0041] Figure 15 A circuit diagram (state 100) of a specific implementation of the motor drive circuit control method provided in Embodiment 7 of the present invention when switch a experiences an open circuit fault.

[0042] Figure 16 When switch a experiences an open circuit fault, a circuit diagram (state 101) of another specific implementation of the motor drive circuit control method provided in Embodiment 7 of the present invention is shown.

[0043] Figure 17 When switch a experiences an open circuit fault, a circuit diagram (state 110) of another specific implementation of the motor drive circuit control method provided in Embodiment 7 of the present invention is shown.

[0044] Figure 18 The circuit diagram (state 111) shows that the drive circuit cannot provide assistance to the motor when switch A experiences an open circuit fault.

[0045] Figure 19 This is a schematic diagram of the current change in a motor driven by a drive circuit controlled by the control method of the motor drive circuit provided in Embodiments 4-7 of the present invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Drive circuit; 11. Power supply; 110. Positive terminal; 111. Negative terminal; 12. Bridge arm; 120. Switch; 13. Capacitor; 14. Resistor; 15. Phase separator;

[0048] 20. Multiphase winding. Detailed Implementation

[0049] An electric motor is a device that uses the principle of electromagnetic induction to generate a rotating magnetic field in its multi-phase windings, thereby outputting torque. Taking the electric power steering (EPS) system in automobiles as an example, the motor can generate torque to assist the steering wheel in turning according to the instructions of the ECU. The multi-phase windings of the motor are connected to the positive and negative terminals of the power supply, and a power amplification unit (i.e., a switch) is usually installed between the power supply and the multi-phase windings. The function of the switch is to convert the control signal into electrical energy that enables the motor windings to operate normally.

[0050] The drive circuit mainly includes a control signal input unit, a protection unit (capacitors, resistors, etc.), and a power supply unit (power supply). Typically, the drive circuit also includes multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two power amplifier units (i.e., switches) connected in series. The two ends of each power amplifier unit (i.e., switch) are respectively connected to the positive and negative terminals of the power supply. The function of the power amplifier unit is to amplify the weak input control signal to provide sufficient power to the motor. In addition, the direction of the current can be changed by controlling the conduction and cutoff of the power amplifier unit, thereby generating AC output. Therefore, the power amplifier unit is the core component of the drive circuit. Common power amplification elements include transistors (such as bipolar junction transistors (BJTs) and field-effect transistors (MOSFETs)) and integrated circuits (such as power amplifier chips).

[0051] In the aforementioned drive circuit, the two switches in each bridge arm are connected to the motor windings via leads, and the motor windings are interconnected. A fault in any switch in the drive circuit will affect the normal operation of the entire drive circuit and the normal operation of the motor. For example, if a switch in the drive circuit experiences a short circuit, ... Figure 1As shown, a short circuit fault occurs in switch 120 in the drive circuit. When the steering wheel is turned, the motor in the electric power steering system is driven into generator mode. The motor winding 20 will form a closed loop through the short-circuited switch 120 and the parasitic diodes of the normal switches 120 and 120, resulting in a large resistance torque and affecting driving safety.

[0052] In existing technologies, to prevent circuit failure caused by a switch malfunction in the drive circuit, the common method used in protection circuits is to cut off the current to the entire circuit, such as... Figure 2 As shown, a phase line separator 15 is installed on the lead wires between the two switches of each bridge arm. In case of a fault, all phase line separators 15 are disconnected. However, after the current of the entire circuit is cut off by this protection circuit method, the drive circuit cannot provide assistance to the motor. The sudden lack of power assistance when the vehicle is in motion will cause the driver to panic and seriously affect driving safety. In addition, due to the loss of power assistance, the driver needs a lot of hand torque to turn the steering wheel.

[0053] In existing technologies, to ensure that the drive circuit can continue to operate even when individual switches fail, all other switches in the same phase as the faulty switch are turned off. This prevents current from flowing through the phase containing the faulty switch, thus protecting the circuit. However, this method is essentially a phase loss protection, completely cutting off the current in the faulty phase. This can lead to imbalances in the rotating magnetic field of the motor stator, inconsistent relative speeds between the stator and rotor, increased friction, rapid temperature rise, or severe fluctuations in motor parameters such as current and voltage. This can result in magnetic field distortion, excessively high temperatures, and large fluctuations in current and voltage, potentially damaging the motor in severe cases.

[0054] To address the aforementioned problems, this invention provides a control method for a motor drive circuit, a motor, and a drive circuit. When a short circuit or open circuit fault occurs in one of the switches in the drive circuit, corresponding opening and closing controls are applied to the switches in the same bridge arm and other bridge arms that have not experienced faults. This prevents two switches in the same bridge arm from simultaneously conducting and forming closed loops with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through each bridge arm and each winding corresponding to each bridge arm, preventing faults such as magnetic field distortion, excessive temperature, and large current and voltage fluctuations caused by phase loss. Simultaneously, a power supply loop is formed to provide assistance to the motor.

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below.

[0056] Example 1

[0057] This invention provides a motor whose drive circuit includes a power supply and multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series, with one switch directly connected to the positive terminal of the power supply and the other directly connected to the negative terminal. The motor drive circuit is controlled using a control method for the motor drive circuit. The motor includes multi-phase windings, one end of which is connected to the drive circuit. One end of each phase winding is connected to the neutral point, and the other end has a phase line connected to the two switches of the corresponding bridge arm in the drive circuit. Thus, each phase winding can be connected to the positive or negative terminal of the power supply through the switch in the corresponding bridge arm. It should be noted that the multi-phase winding can specifically be a three-phase winding, a four-phase winding, a five-phase winding, etc., as long as one end of each phase winding is connected to the neutral point, ensuring that current can flow between the multi-phase windings at the neutral point. Taking a three-phase winding as an example, the corresponding drive circuit of the motor includes three bridge arms. One end of each phase winding in the three-phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between the two switches of the corresponding bridge arm in the drive circuit.

[0058] It should also be noted that the motor can specifically be a reluctance synchronous motor, an electrically excited synchronous motor, a permanent magnet synchronous motor, etc., as long as the current flowing through the stator windings of the motor can generate a rotating magnetic field and output torque. Taking a permanent magnet synchronous motor as an example, when this permanent magnet synchronous motor is used in the automotive field, it can output a large torque to assist in turning the steering wheel, thereby helping the driver to turn the steering wheel more easily.

[0059] Example 2

[0060] The present invention also provides a drive circuit, including a power supply and a plurality of bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series. One switch in each bridge arm is directly connected to the positive terminal of the power supply, and the other switch is directly connected to the negative terminal of the power supply. The two switches in each bridge arm can be connected to the multiphase windings of the motor driven by the drive circuit via phase lines.

[0061] It should be noted that the number of bridge arms in the drive circuit can be three, four, five, etc., as long as each bridge arm is connected in parallel with the power supply, and each bridge arm includes a switch that is directly connected to the positive terminal of the power supply and another switch that is directly connected to the negative terminal of the power supply.

[0062] It should also be noted that the switch can specifically be a bipolar junction transistor (BJT), a field-effect transistor (MOSFET), or other power amplifier chips capable of switching on and off, or connected to a switch, as long as it can amplify the control signal to provide sufficient power to the motor and change the direction of the current by controlling its conduction and cutoff. In this embodiment, a MOSFET is used as an example. The MOSFET can amplify the control signal and can also change the direction of the current in the drive circuit by controlling the conduction and cutoff of the MOSFET, thereby generating an AC output to assist the motor.

[0063] It is understood that the drive circuit can be used to drive the motor provided in Embodiment 1. Taking a three-phase motor as an example, when the drive circuit drives a motor including three-phase windings, the drive circuit includes three bridge arms connected in parallel with the power supply, and the two switches of each bridge arm are connected to the corresponding motor windings through a phase line.

[0064] In one specific embodiment of the present invention, the drive circuit further includes a capacitor connected in parallel with the power supply and a resistor connected in series with the capacitor. Specifically, the capacitor allows for charging and discharging, resulting in a more stable voltage and providing a stable power supply for the subsequent inverter circuit. The resistor connected in series in the power input line prevents excessive current surges during drive circuit startup from damaging the circuit.

[0065] Example 3

[0066] This invention also provides a control method for a motor drive circuit, used to control the motor drive circuit. The drive circuit includes a power supply and multiple bridge arms connected in parallel with the power supply. Each bridge arm includes two switches connected in series, one of which is directly connected to the positive terminal of the power supply, and the other is directly connected to the negative terminal. The direction of the current can be changed by controlling the on / off state of each switch in each bridge arm of the drive circuit. The motor includes multi-phase windings, with one end of each phase winding connected to the neutral point, allowing current to flow between the multi-phase windings. The other end of each phase winding has a phase line connected to the two switches in the corresponding bridge arm of the drive circuit, so that each phase winding can be connected to the positive or negative terminal of the power supply by connecting to any one of the switches in the corresponding bridge arm. When a short circuit or open circuit fault occurs in a switch in the drive circuit, corresponding control measures need to be taken for the other switches to protect the circuit.

[0067] Specifically, when a switch experiences a short-circuit fault, the switch with the first fault is essentially in a conducting state. Therefore, the bridge arm containing the switch with the short-circuit fault is determined to have experienced a first fault. By controlling the other switch in that bridge arm to open, the simultaneous conduction of both switches in that bridge arm with the positive and negative terminals of the power supply is prevented, thus protecting the circuit. By controlling the two switches in each of the other bridge arms that have not experienced a first fault, one is conducting and the other is open. This prevents both switches in each of the other bridge arms from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other bridge arms that have not experienced a first fault to form a power supply circuit with the bridge arm that has experienced a first fault, the current generates a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0068] When a switch experiences an open-circuit fault, it is determined that a second fault has occurred in the bridge arm containing the faulty switch. By controlling the other switch in that bridge arm to conduct, current can be ensured to flow through the bridge arm with the second fault. By controlling the two switches in each of the other bridge arms that have not experienced a second fault, one is conducting and the other is open. This prevents both switches in each of the bridge arms that have not experienced a second fault from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply, thus protecting the circuit. Furthermore, it ensures that current flows through each bridge arm and each winding corresponding to each bridge arm, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other bridge arms that have not experienced a second fault to form a power circuit with the bridge arm that has experienced a second fault, the current generates a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0069] It should be noted that the drive circuit controlled by the control method provided in this embodiment may specifically include three bridge arms, four bridge arms, five bridge arms, etc., as long as it can be connected in parallel with the power supply. Correspondingly, the motor driven by the drive circuit may specifically include three-phase windings, four-phase windings, five-phase windings, etc.

[0070] In one specific embodiment of the present invention, taking the case where the motor includes three-phase windings and the corresponding drive circuit includes three bridge arms as an example, the entire drive circuit includes three parallel bridge arms and a total of six switches. Each bridge arm of the drive circuit is connected to the three-phase windings of the motor to drive the motor. One end of each phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between the two switches of the corresponding bridge arm.

[0071] Using the control method provided in this embodiment to control the drive circuit, when one of the six switches experiences a short circuit or open circuit fault, the on / off state of the remaining five switches is controlled so that current flows through the three bridge arms and their corresponding windings. The faulty bridge arm and its corresponding winding can form a power circuit with the unfaulty bridge arm and its corresponding winding, so that the current generates a rotating magnetic field in multiple windings to provide assistance to the motor.

[0072] Specifically, when a switch experiences a short-circuit fault, the faulty switch is essentially in a conducting state. Therefore, the bridge arm containing the faulty switch is considered to have experienced a first fault. By controlling the other switch in that bridge arm to open, the simultaneous conduction of both switches in that bridge arm with the positive and negative terminals of the power supply is prevented, thus protecting the circuit. By controlling the two switches in each of the other two bridge arms that have not experienced a first fault to have one conducting and the other open, it is possible to prevent both switches in each of the non-faulty bridge arms from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply. Furthermore, it ensures that current flows through all three bridge arms and their corresponding three windings, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Moreover, by controlling at least one of the other two non-faulty bridge arms to form a power circuit with the faulty bridge arm, the current generates a rotating magnetic field in the three-phase windings, thereby providing assistance to the motor.

[0073] When a switch experiences an open-circuit fault, it is determined that a second fault has occurred in the bridge arm containing the faulty switch. By controlling the other switch in that bridge arm to conduct, current can be ensured to flow through the bridge arm with the second fault. By controlling one switch in each of the other two bridge arms without a second fault to conduct while the other is open, it is possible to prevent both switches in each of the bridge arms without a second fault from simultaneously conducting and forming a closed circuit with the positive and negative terminals of the power supply, thus protecting the circuit. On the other hand, it also ensures that current flows through all three bridge arms and their corresponding three windings, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Furthermore, by controlling at least one of the other two bridge arms without a second fault to form a power supply circuit with the bridge arm with the second fault, the current can generate a rotating magnetic field in the three-phase windings, thereby providing assistance to the motor.

[0074] The present invention also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the control method of the drive circuit of the motor described above.

[0075] Example 4

[0076] The present invention also provides a control method for a motor drive circuit, which is used to control the motor drive circuit. When the switch in the bridge arm in which the first fault occurs in the drive circuit is a switch directly connected to the positive terminal of the power supply, the switch that has the short circuit fault is equivalent to being directly connected to the positive terminal of the power supply. The other switch in the bridge arm is a switch directly connected to the negative terminal of the power supply. By controlling the other switch in the bridge arm to disconnect, it is possible to prevent both switches in the bridge arm from being simultaneously turned on and forming a closed loop with the positive and negative terminals of the power supply.

[0077] Furthermore, the system controls two switches in each bridge arm that has not experienced the first fault to be configured such that one is on and the other is off. This prevents both switches in each bridge arm from simultaneously being on and forming closed circuits with the positive and negative terminals of the power supply. It also ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Specifically, in at least one of the bridge arms that has not experienced the first fault, the on-circuit switch is directly connected to the negative terminal of the power supply. Current from the positive terminal of the power supply can flow through the short-circuited switch to the corresponding winding, and then through the neutral point to the on-circuit switch in the bridge arm that has not experienced the first fault and is directly connected to the negative terminal of the power supply, thus forming a power supply circuit. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0078] It should be noted that the drive circuit controlled by the control method provided in this embodiment may specifically include three bridge arms, four bridge arms, five bridge arms, etc., as long as it can be connected in parallel with the power supply. Correspondingly, the motor driven by the drive circuit may specifically include three-phase windings, four-phase windings, five-phase windings, etc.

[0079] For ease of understanding, the following embodiments use the motor with three-phase windings provided in Embodiment 1 and the drive circuit with three bridge arms provided in Embodiment 2 as examples, in conjunction with Table 1 and... Figures 3-6 The control method of the motor drive circuit 1 provided in this embodiment will be described.

[0080] First, it needs to be explained that, as Figures 3-6As shown, the driving circuit includes a power supply 11, three bridge arms 12, a capacitor 13, and a resistor 14. Each bridge arm 12 includes two switches 120, for a total of six. Specifically, switches A 120, B 120, and C 120 are connected to the positive terminal 110 of the power supply, and switches a 120, b 120, and c 120 are connected to the negative terminal 111 of the power supply. Switches A 120 and a 120 form the first bridge arm 12, switches B 120 and b 120 form the second bridge arm 12, and switches C 120 and c 120 form the third bridge arm 12. The multiphase winding 20 of the motor is specifically a three-phase winding, namely U phase, V phase, and W phase. One end of U phase, V phase, and W phase is connected to the neutral point, and the other end of U phase is connected to the A switch 120 and a switch 120 of the first bridge arm 12 through a phase line. The other end of V phase is connected to the B switch 120 and b switch 120 of the second bridge arm 12 through a phase line. The other end of W phase is connected to the C switch 120 and c switch 120 of the third bridge arm 12 through a phase line.

[0081] Table 1 shows the control method and the voltage corresponding to each phase winding when a short-circuit fault occurs in switch A 120. In the status column, "1" represents that a bridge arm 12 is in a state where switch 120 connected to the positive terminal 110 of the power supply is short-circuited or on, and switch 120 connected to the negative terminal 111 of the power supply is open-circuited. "0" represents that a bridge arm 12 is in a state where switch 120 connected to the positive terminal 110 of the power supply is open-circuited, and switch 120 connected to the negative terminal 111 of the power supply is short-circuited or on. The codes in the status column correspond to the first bridge arm 12, the second bridge arm 12, and the third bridge arm 12 in sequence. In the switch Ac column, "1" represents that switch 120 is in a short-circuit or on state, and "0" represents that switch 120 is in an open-circuit state.

[0082] Table 1

[0083]

[0084] The control methods for each bridge arm 12 and each switch 120 in Table 1 are explained below with reference to the attached drawings.

[0085] like Figure 3The table shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 100. When switch A 120 experiences a short-circuit fault, it is equivalent to being directly connected to the positive terminal 110 of the power supply 11. Switch a 120, which is in the same first bridge arm 12, is directly connected to the negative terminal 111 of the power supply 11, thus controlling switch a 120 to open. Furthermore, it controls switch b 120 to turn on and switch B 120 to open in the second bridge arm 12 (where no first fault has occurred), and switch c 120 to turn on and switch C 120 to open in the third bridge arm 12. Among them, switch b 120 and switch c 120 are switches 120 directly connected to the negative terminal 111 of power supply 11. The current starting from the positive terminal 110 of power supply 11 can flow through switch A 120, which has a short circuit fault, to the corresponding U-phase winding, and then through the neutral point to the V-phase and W-phase windings. It then returns to the negative terminal 111 of power supply 11 through switch b 120 and switch c 120, thus forming a power supply loop. This causes the current to generate a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0086] like Figure 4 As shown in Table 1, this illustrates the specific states of each switch 120 and the voltage state of each phase winding when the state code for the three bridge arms 12 is 101. When switch A 120 experiences a short-circuit fault, it is equivalent to being directly connected to the positive terminal 110 of power supply 11. Switch a 120, which is in the same first bridge arm 12, is directly connected to the negative terminal 111 of power supply 11, thus controlling switch a 120 to open. Furthermore, it controls switch b 120 to turn on and switch B 120 to open in the second bridge arm 12 (where no first fault has occurred), and switch C 120 to turn on and switch c 120 to open in the third bridge arm 12. Among them, switch C 120 is a switch 120 directly connected to the positive terminal 110 of power supply 11, and switch b 120 is a switch 120 directly connected to the negative terminal 111 of power supply 11. The current starting from the positive terminal 110 of power supply 11 can flow through switch A 120 which has a short circuit fault and switch C 120 which is conducting to the corresponding U-phase and W-phase windings, and then flow through the neutral point to the V-phase, and then return to the negative terminal 111 of power supply 11 through switch b 120, thereby forming a power supply loop, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0087] like Figure 5 As shown in Table 1, this table shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 110. When switch A 120 experiences a short circuit fault, it is equivalent to being directly connected to the positive terminal 110 of the power supply 11. Switch a 120, which is in the same first bridge arm 12 as switch A, is directly connected to the negative terminal 111 of the power supply 11. Switch a 120 is controlled to open the circuit.

[0088] Furthermore, it controls the B switch 120 of the second bridge arm 12 (which has not experienced the first fault) to be turned on and the b switch 120 to be turned off, and the c switch 120 of the third bridge arm 12 to be turned on and the C switch 120 to be turned off. Among them, the B switch 120 is the switch 120 directly connected to the positive terminal 110 of the power supply 11, and the c switch 120 is the switch 120 directly connected to the negative terminal 111 of the power supply 11. The current starting from the positive terminal 110 of the power supply 11 can flow through the A switch 120 (which has experienced a short circuit fault) and the B switch 120 (which is turned on) to the corresponding U-phase winding and V-phase winding, and then flow through the neutral point to the W-phase winding, and then return to the negative terminal 111 of the power supply 11 through the c switch 120, thus forming a power supply loop, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0089] like Figure 6 As shown in Table 1, this table shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 111. When switch A 120 experiences a short circuit fault, it is equivalent to being directly connected to the positive terminal 110 of the power supply 11. Switch a 120, which is in the same first bridge arm 12 as switch A, is directly connected to the negative terminal 111 of the power supply 11. Switch a 120 is controlled to open the circuit. However, in this situation, if switch B 120 of the second bridge arm 12, which is not experiencing the first fault, is turned on and switch b 120 is turned off, and switch C 120 of the third bridge arm 12 is turned on and switch c 120 is turned off, the current from the positive terminal 110 of the power supply 11 flows through switch A 120, which has a short circuit fault, and switches B 120 and C 120, which are turned on, to the corresponding U-phase, V-phase, and W-phase windings. The current converges at the neutral point and cannot return to the negative terminal 111 of the power supply 11 to form a power circuit. Therefore, the 000 state cannot make the current generate a rotating magnetic field in the three windings to provide assistance to the motor.

[0090] It is understandable that Table 1 and Figures 3-5 Only the control method for a short circuit fault in switch A 120 is shown. The same control principle can also be used to control other switches 120 when short circuit faults occur in switches B 120 and C 120.

[0091] Example 5

[0092] The present invention also provides a control method for a motor drive circuit, which is used to control the motor drive circuit. When the switch in the bridge arm in which the first fault occurs in the drive circuit is a switch directly connected to the negative terminal of the power supply, the switch that has the short circuit fault is equivalent to being directly connected to the negative terminal of the power supply. The other switch in the bridge arm is a switch directly connected to the positive terminal of the power supply. By controlling the other switch in the bridge arm to disconnect, it is possible to prevent both switches in the bridge arm from being simultaneously turned on and forming a closed loop with the positive and negative terminals of the power supply.

[0093] Furthermore, the system controls two switches in each bridge arm that has not experienced the first fault to be configured such that one is on and the other is off. This prevents both switches in each bridge arm from simultaneously being on and forming a closed circuit with the positive and negative terminals of the power supply. It also ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Specifically, in at least one of the bridge arms that has not experienced the first fault, the on switch is directly connected to the positive terminal of the power supply. Current from the positive terminal flows through this on switch to the corresponding winding, then through the neutral point to the switch experiencing the short circuit fault, thus forming a power supply loop. This generates a rotating magnetic field in multiple windings, providing assistance to the motor.

[0094] For ease of understanding, this embodiment uses the same three-phase winding motor and drive circuit with three bridge arms as in Embodiment 4, referring to Table 2 and... Figures 7-10 The control method of the motor drive circuit provided in this embodiment will be described.

[0095] Table 2 shows the control method and the voltage corresponding to each phase winding when a short circuit fault occurs in switch 120. The meanings of "1" and "0" in the status column and "1" and "0" in the switch Ac column are the same as those in Table 1 of Example 4.

[0096] Table 2

[0097]

[0098] The control methods for each bridge arm 12 and each switch 120 in Table 2 are explained below with reference to the attached drawings.

[0099] like Figure 7 Table 2 shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 000. When switch b 120 experiences a short circuit fault, it is equivalent to being directly connected to the negative terminal 111 of power supply 11. Switch B 120, which is in the same second bridge arm 12, is directly connected to the positive terminal 110 of power supply 11. Controlling switch B 120 to open the circuit is crucial. However, in this case, if switch A 120 of the first bridge arm 12, which has not experienced the first fault, is opened and switch a 120 is turned on, and switch C 120 of the third bridge arm 12 is opened and switch c 120 is turned on, the current from the positive terminal 110 of power supply 11 cannot flow through any bridge arm 12 to the corresponding U-phase, V-phase, and W-phase windings. Therefore, the 000 state cannot generate a rotating magnetic field in the three windings to provide assistance to the motor.

[0100] like Figure 8As shown in Table 2, this illustrates the specific states of each switch 120 and the voltage state of each phase winding when the status code for the three bridge arms 12 is 001. When switch b 120 experiences a short-circuit fault, it is equivalent to being directly connected to the negative terminal 111 of power supply 11. Switch B 120, located in the same second bridge arm 12, is directly connected to the positive terminal 110 of power supply 11. Controlling switch B 120 to open the circuit also controls the a switch 120 of the first bridge arm 12 (where the first fault has not occurred) to be turned on and the a switch 120 to be turned off, and the c switch 120 of the third bridge arm 12 to be turned on and the c switch 120 to be turned off. Among them, switch C 120 is a switch 120 directly connected to the positive terminal 110 of power supply 11, and switch a 120 is a switch 120 directly connected to the negative terminal 111 of power supply 11. The current starting from the positive terminal 110 of power supply 11 can flow through the conducting switch C 120 to the corresponding W phase winding, and then through the neutral point to the U phase and V phase windings, and then through switch a 120 and switch b 120 back to the negative terminal 111 of power supply 11, thus forming a power supply circuit, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0101] like Figure 9 As shown in Table 2, this illustrates the specific states of each switch 120 and the voltage state of each phase winding when the status code for the three bridge arms 12 is 100. When switch b 120 experiences a short-circuit fault, it is equivalent to being directly connected to the negative terminal 111 of power supply 11. Switch B 120, located in the same second bridge arm 12, is directly connected to the positive terminal 110 of power supply 11, thus controlling switch B 120 to open. Furthermore, it controls the A switch 120 of the first bridge arm 12 (where the first fault has not occurred) to be turned on and the a switch 120 to be turned off, and the c switch 120 of the third bridge arm 12 to be turned on and the C switch 120 to be turned off. Among them, switch A 120 is a switch 120 directly connected to the positive terminal 110 of power supply 11, and switch c 120 is a switch 120 directly connected to the negative terminal 111 of power supply 11. The current starting from the positive terminal 110 of power supply 11 can flow through the conducting switch A 120 to the corresponding U-phase winding, and then flow through the neutral point to the W-phase and V-phase windings, and then return to the negative terminal 111 of power supply 11 through switch b 120 and switch c 120, thus forming a power supply circuit, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0102] like Figure 10As shown in Table 2, this illustrates the specific states of each switch 120 and the voltage state of each phase winding when the state code for the three bridge arms 12 is 101. When switch b 120 experiences a short-circuit fault, it is equivalent to being directly connected to the negative terminal 111 of power supply 11. Switch B 120, which is in the same second bridge arm 12, is directly connected to the positive terminal 110 of power supply 11. This controls switch B 120 to open. Furthermore, it controls switch A 120 to turn on and switch a 120 to open in the first bridge arm 12 where no first fault has occurred, and switch C 120 to turn on and switch c 120 to open in the third bridge arm 12. Among them, switch A 120 and switch C 120 are switches 120 directly connected to the positive terminal 110 of power supply 11. The current from the positive terminal 110 of power supply 11 can flow through the conducting switches A 120 and C 120 to the corresponding U-phase and W-phase windings, and then flow through the neutral point to the V-phase winding, and then return to the negative terminal 111 of power supply 11 through switch b 120, thus forming a power supply loop, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0103] It is understandable that Table 2 and Figures 8-10 Only the control method for a short circuit fault in switch b 120 is shown. The same control principle as the above control method can also be used to control other switches 120 when short circuit faults occur in switches a 120 and c 120.

[0104] Example 6

[0105] The present invention also provides a control method for a motor drive circuit, which is used to control the motor drive circuit. When the switch in the bridge arm in which the second fault occurs is a switch directly connected to the positive terminal of the power supply, the other switch in the bridge arm is a switch directly connected to the negative terminal of the power supply. By controlling the other switch in the bridge arm to be turned on, the bridge arm in which the second fault occurs can be guaranteed to carry current.

[0106] Furthermore, the system controls two switches in each bridge arm that has not experienced a second fault, ensuring that one switch is on and the other is off. This prevents both switches in each bridge arm from simultaneously being on and forming closed circuits with the positive and negative terminals of the power supply. It also ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Specifically, in at least one of the bridge arms that has not experienced a second fault, the on-circuit switch is directly connected to the positive terminal of the power supply. Current from the positive terminal flows through the on-circuit switch in the bridge arm that has not experienced a second fault to the corresponding winding, and then through the neutral point to the on-circuit switch in the bridge arm that has experienced a second fault, which is directly connected to the negative terminal of the power supply, thus forming a power circuit. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0107] For ease of understanding, this embodiment uses the same three-phase winding motor and drive circuit with three bridge arms as in Embodiment 4, referring to Table 3 and... Figures 11-14 The control method of the motor drive circuit provided in this embodiment will be described.

[0108] Table 3 shows the control method and the voltage corresponding to each phase winding when switch A 120 experiences a circuit breaker fault. The meanings of "1" and "0" in the status column and "1" and "0" in the switch Ac column are the same as those in Table 1 of Example 4.

[0109] Table 3

[0110]

[0111] The control methods for each bridge arm 12 and each switch 120 in Table 3 are explained below with reference to the attached drawings.

[0112] like Figure 11 Table 3 shows the specific states of each switch 120 and the voltage state of each phase winding when the status code of the three bridge arms 12 is 000. When switch A 120 experiences an open-circuit fault, switch a 120 in the first bridge arm 12 is directly connected to the negative terminal 111 of the power supply 11, and controls switch a 120 in this bridge arm 12 to be turned on. However, in this case, if switch B 120 in the second bridge arm 12 (which has not experienced a second fault) is turned off and switch b 120 is turned on, and switch C 120 in the third bridge arm 12 is turned off and switch c 120 is turned on, the current from the positive terminal 110 of the power supply 11 cannot flow through any bridge arm 12 to the corresponding U-phase, V-phase, and W-phase windings. Therefore, the 000 state cannot generate a rotating magnetic field in the three windings to provide assistance to the motor.

[0113] like Figure 12 As shown in Table 3, the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 001 are shown. When switch A 120 has an open circuit fault, switch a 120 in the first bridge arm 12 is the switch 120 directly connected to the negative terminal 111 of the power supply 11, and controls switch a 120 in this bridge arm 12 to be turned on.

[0114] Furthermore, it controls the second bridge arm 12 (where no second fault has occurred) to have its b switch 120 turned on and its B switch 120 turned off, and the third bridge arm 12 to have its C switch 120 turned on and its c switch 120 turned off. Here, the C switch 120 is directly connected to the positive terminal 110 of the power supply 11, and the b switch 120 is directly connected to the negative terminal 111 of the power supply 11. Current originating from the positive terminal 110 of the power supply 11 can flow through the turned-on C switch 120 to the corresponding W-phase winding, then through the neutral point to the U-phase and V-phase windings, and finally through the a switch 120 and b switch 120 back to the negative terminal 111 of the power supply 11, thus forming a power circuit. This causes the current to generate a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0115] like Figure 13 As shown in Table 3, the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 010 are shown. When switch A 120 has an open circuit fault, switch a 120 in the first bridge arm 12 is the switch 120 directly connected to the negative terminal 111 of the power supply 11, and controls switch a 120 in this bridge arm 12 to be turned on.

[0116] Furthermore, it controls the B switch 120 of the second bridge arm 12, which has not experienced a second fault, to be turned on and the b switch 120 to be turned off, while the C switch 120 of the third bridge arm 12 is turned off and the c switch 120 is turned on. Specifically, the B switch 120 is directly connected to the positive terminal 110 of the power supply 11, and the a and c switches 120 are directly connected to the negative terminal 111 of the power supply 11. Current originating from the positive terminal 110 of the power supply 11 can flow through the turned-on B switch 120 to the corresponding V-phase winding, then through the neutral point to the U-phase and W-phase windings, and finally through the a and c switches 120 back to the negative terminal 111 of the power supply 11, thus forming a power circuit. This causes the current to generate a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0117] like Figure 14 As shown in Table 3, the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 011 are shown. When switch A 120 has an open circuit fault, switch a 120 in the first bridge arm 12 is the switch 120 directly connected to the negative terminal 111 of the power supply 11, and controls switch a 120 in this bridge arm 12 to be turned on.

[0118] Furthermore, it controls the B switch 120 of the second bridge arm 12, which has not experienced a second fault, to be turned on and the b switch 120 to be turned off, and the C switch 120 of the third bridge arm 12 to be turned on and the c switch 120 to be turned off. Among them, the B switch 120 and the C switch 120 are switches 120 directly connected to the positive terminal 110 of the power supply 11. The current from the positive terminal 110 of the power supply 11 can flow through the turned-on B switch 120 and C switch 120 to the corresponding W phase and V phase windings, and then flow through the neutral point to the U phase winding, and then return to the negative terminal 111 of the power supply 11 through the a switch 120, thus forming a power supply loop, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0119] Understandably, Table 3 and Figures 12-14 Only the control method for a circuit breaker fault in switch A 120 is shown. The same control principle can also be used to control other switches 120 when circuit breaker faults occur in switches B 120 and C 120.

[0120] Example 7

[0121] The present invention also provides a control method for a motor drive circuit, which is used to control the motor drive circuit. When the switch in the bridge arm in which the second fault occurs is a switch directly connected to the negative terminal of the power supply, the other switch in the bridge arm is a switch directly connected to the positive terminal of the power supply. By controlling the other switch in the bridge arm to be turned on, the bridge arm in which the second fault occurs can be guaranteed to carry current.

[0122] Furthermore, the system controls two switches in each of the remaining bridge arms that have not experienced a second fault, ensuring that one switch is on and the other is off. This prevents both switches in each bridge arm from simultaneously being on and forming a closed circuit with the positive and negative terminals of the power supply. It also ensures that current flows through each bridge arm and its corresponding winding, preventing faults such as magnetic field distortion, overheating, and large current and voltage fluctuations caused by phase loss. Specifically, in at least one of the remaining bridge arms that have not experienced a second fault, the on switch is directly connected to the negative terminal of the power supply. This allows current from the positive terminal of the power supply to flow through the on switch in the bridge arm experiencing the second fault to the corresponding winding, and then through the neutral point to the on switch in the bridge arm that has not experienced a second fault and is directly connected to the negative terminal of the power supply, thus forming a power circuit. This causes the current to generate a rotating magnetic field in multiple windings, thereby providing assistance to the motor.

[0123] For ease of understanding, this embodiment uses the same three-phase winding motor and drive circuit with three bridge arms as in Embodiment 4, referring to Table 4 and... Figures 15-18 The control method of the motor drive circuit provided in this embodiment will be described.

[0124] Table 4 shows the control method and the voltage corresponding to each phase winding when switch 120 experiences an open circuit fault. The meanings of "1" and "0" in the status column and "1" and "0" in the switch Ac column are the same as those in Table 1 of Example 4.

[0125] Table 4

[0126]

[0127] The control methods for each bridge arm 12 and each switch 120 in Table 4 are explained below with reference to the attached drawings.

[0128] like Figure 15 The table shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 100. When switch a 120 has an open circuit fault, switch A 120, which is in the same first bridge arm 12 as it, is directly connected to the positive terminal 110 of the power supply 11, and controls switch A 120 to conduct.

[0129] Furthermore, it controls the second bridge arm 12, where no second fault has occurred, to have its b switch 120 turned on and its B switch 120 turned off, and the third bridge arm 12, where its c switch 120 is turned on and its C switch 120 is turned off. Switches b and c are directly connected to the negative terminal 111 of the power supply 11. Current originating from the positive terminal 110 of the power supply 11 flows through the A switch 120 in the bridge arm 12 where the second fault has occurred to the corresponding U-phase winding, then through the neutral point to the V-phase and W-phase windings, and finally through switches b and c to return to the negative terminal 111 of the power supply 11, thus forming a power circuit. This causes the current to generate a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0130] like Figure 16 As shown in Table 4, the specific states of each switch 120 and the voltage state of each phase winding are when the state code of the three bridge arms 12 is 101. When switch a 120 has an open circuit fault, switch A 120, which is in the same first bridge arm 12 as it, is directly connected to the positive terminal 110 of the power supply 11, and controls switch A 120 to conduct.

[0131] Furthermore, it controls the second bridge arm 12, where the second fault has not occurred, to have its b switch 120 turned on and its B switch 120 turned off, and the third bridge arm 12, where its C switch 120 is turned on and its c switch 120 is turned off. Here, the C switch 120 is directly connected to the positive terminal 110 of the power supply 11, and the b switch 120 is directly connected to the negative terminal 111 of the power supply 11. The current from the positive terminal 110 of the power supply 11 can flow through the turned-on A switch 120 and the turned-on C switch 120 in the bridge arm 12 where the second fault has occurred to the corresponding U-phase and W-phase windings, then through the neutral point to the V-phase, and finally through the b switch 120 back to the negative terminal 111 of the power supply 11, thus forming a power circuit. This causes the current to generate a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0132] like Figure 17 As shown in Table 4, this table shows the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 110. When switch a 120 experiences an open circuit fault, switch A 120, which is located in the first bridge arm 12 and is directly connected to the positive terminal 110 of the power supply 11, controls switch A 120 to conduct.

[0133] Furthermore, it controls the B switch 120 of the second bridge arm 12, which has not experienced a second fault, to be turned on and the b switch 120 to be turned off, and the c switch 120 of the third bridge arm 12 to be turned on and the C switch 120 to be turned off. Among them, the B switch 120 is the switch 120 directly connected to the positive terminal 110 of the power supply 11, and the c switch 120 is the switch 120 directly connected to the negative terminal 111 of the power supply 11. The current from the positive terminal 110 of the power supply 11 can flow through the A switch 120 and the B switch 120 in the bridge arm 12 that has experienced a second fault to the corresponding U-phase winding and V-phase winding, and then flow through the neutral point to the W-phase winding, and then return to the negative terminal 111 of the power supply 11 through the c switch 120, thereby forming a power circuit, so that the current generates a rotating magnetic field in the three windings, thereby providing assistance to the motor.

[0134] like Figure 18 As shown in Table 4, the specific states of each switch 120 and the voltage state of each phase winding when the state code of the three bridge arms 12 is 000 are shown. When switch a 120 has an open circuit fault, switch A 120, which is in the same first bridge arm 12 as it, is directly connected to the positive terminal 110 of the power supply 11, and controls switch A 120 to conduct.

[0135] However, in this situation, if switch B 120 is turned on and switch b 120 is turned off in the second bridge arm 12 that has not experienced a second fault, and switch C 120 is turned on and switch c 120 is turned off in the third bridge arm 12, the current from the positive terminal 110 of the power supply 11 flows through the turned-on switch A 120 and the turned-on switches B 120 and C 120 in the bridge arm 12 that experienced a second fault to the corresponding U-phase, V-phase, and W-phase windings. The current converges at the neutral point and cannot return to the negative terminal 111 of the power supply 11 to form a power circuit. Therefore, the 000 state cannot cause the current to generate a rotating magnetic field in the three windings to provide assistance to the motor.

[0136] Understandably, Table 4 and Figures 15-18 Only the control method for when switch a 120 experiences an open circuit fault is shown. The same control principle as the above control method can also be used to control other switches 120 when switches b 120 and c 120 experience open circuit faults.

[0137] The schematic diagrams of the states 101, 100, 110, 010, 011, and 001 of the drive circuit listed in Examples 4 to 7 under the above control method, and the corresponding voltage changes of the U-phase, V-phase, and W-phase of the motor windings, are shown below. Figure 19 As shown, Figure 19 The horizontal axis represents time, and the vertical axis represents voltage. A positive vertical axis indicates a positive current direction in the winding, while a negative vertical axis indicates a negative current direction. The motor using the above control method is controlled using space vector pulse width modulation technology.

[0138] It should be noted that, in addition to the specific embodiments described above, those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to those embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0139] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0140] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0141] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0142] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A control method of a drive circuit of an electric motor, for controlling a drive circuit of an electric motor, the drive circuit comprising a power supply and a plurality of bridge arms arranged in parallel with the power supply, each of the bridge arms comprising two switches connected in series, one of the two switches being directly connected to a positive pole of the power supply and the other being directly connected to a negative pole of the power supply, characterized in that, The motor includes multi-phase windings, with one end of each phase winding connected to the neutral point and the other end having a phase wire connected to the two switches of a corresponding bridge arm; wherein, the control method includes: When a short-circuit fault occurs in one of the switches, it is determined that a first fault has occurred in the bridge arm containing the short-circuit faulted switch. The other switch in the bridge arm with the first fault is then de-circuited, and in each of the other bridge arms that have not experienced the first fault, one switch is turned on and the other is de-circuited. Furthermore, at least one of the other bridge arms that have not experienced the first fault forms a power circuit with the bridge arm that experienced the first fault; or When one of the switches experiences an open circuit fault, it is determined that the bridge arm containing the switch with the open circuit fault has a second fault. The other switch in the bridge arm with the second fault is controlled to be turned on, and the two switches in each of the other bridge arms that have not experienced a second fault are controlled so that one is turned on and the other is turned off. Furthermore, at least one of the other bridge arms that have not experienced a second fault forms a power circuit with the bridge arm that has experienced a second fault.

2. The control method of the drive circuit of the motor according to claim 1, characterized by, When the switch in the bridge arm where the first fault occurs that is directly connected to the positive terminal of the power supply is short-circuited, the other switch in the bridge arm where the first fault occurs is controlled to open, and the two switches in each of the other bridge arms where the first fault does not occur are controlled so that one is on and the other is off; wherein, at least one of the switches in the other bridge arms where the first fault does not occur is a switch directly connected to the negative terminal of the power supply.

3. The control method of the drive circuit of the motor according to claim 1, characterized by, When the switch in the bridge arm where the first fault occurs that is directly connected to the negative terminal of the power supply is short-circuited, the other switch in the bridge arm where the first fault occurs is controlled to open, and the two switches in each of the other bridge arms where the first fault does not occur are controlled so that one is on and the other is off; wherein, at least one of the switches in the other bridge arms where the first fault does not occur is a switch directly connected to the positive terminal of the power supply.

4. The control method of the drive circuit of the motor according to claim 1, characterized by, When the switch in the bridge arm where the second fault occurs that has an open circuit fault is a switch directly connected to the positive terminal of the power supply, the other switch in the bridge arm where the second fault occurs is controlled to be turned on, and the two switches in each of the other bridge arms where the second fault does not occur are controlled so that one is turned on and the other is turned off; wherein, at least one of the bridge arms where the second fault does not occur has a switch that is turned on that is a switch directly connected to the positive terminal of the power supply.

5. The control method of the drive circuit of the motor according to claim 1, characterized by, When the switch in the bridge arm where the second fault occurs that has an open circuit fault is a switch directly connected to the negative terminal of the power supply, the other switch in the bridge arm where the second fault occurs is controlled to be turned on, and the two switches in each of the other bridge arms where the second fault does not occur are controlled so that one is turned on and the other is turned off; wherein, at least one of the bridge arms where the second fault does not occur has a switch that is turned on that is a switch directly connected to the negative terminal of the power supply.

6. The control method for the motor drive circuit as described in any one of claims 1-5, characterized in that, The control method is used to control the drive circuit, which includes three bridge arms connected in parallel with the power supply; the motor includes a three-phase winding, and the drive circuit is connected to the three-phase winding of the motor to drive the motor, wherein one end of each phase winding is connected to the neutral point, and the other end is led out with the phase line and connected between the two switches of the corresponding bridge arm.

7. A motor, wherein the motor's drive circuit includes a power supply and a plurality of bridge arms connected in parallel with the power supply, each bridge arm including two switches connected in series, wherein one of the two switches is directly connected to the positive terminal of the power supply and the other is directly connected to the negative terminal of the power supply, characterized in that, The drive circuit is controlled using the control method of the motor drive circuit as described in any one of claims 1-6; the motor includes a multi-phase winding, the multi-phase winding being a three-phase winding, wherein one end of each phase of the three-phase winding is connected to the neutral point, and the other end is led out with a phase line and connected between the two switches of the corresponding bridge arm in the drive circuit.

8. A driving circuit, the driving circuit comprising a power supply, a plurality of bridge arms connected in parallel with the power supply, each bridge arm comprising two switches connected in series, one of the two switches in each bridge arm being directly connected to the positive terminal of the power supply and the other being directly connected to the negative terminal of the power supply; characterized in that, The drive circuit is controlled using the control method for the motor drive circuit as described in any one of claims 1-6.

9. The driving circuit as described in claim 8, characterized in that, The driving circuit also includes a capacitor connected in parallel with the power supply and a resistor connected in series with the capacitor.

10. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the control method for the motor drive circuit as described in any one of claims 1-6.

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