Motor open-phase operation control method and device, motor controller and electric drive assembly

Abstract

The invention provides a motor open-phase operation control method and device, a motor controller and an electric drive assembly. The motor open-phase operation control method comprises the following steps: acquiring an open-phase state, a torque demand, a rotor angle and a rotor rotating speed of the motor; and calculating a synthetic current angle according to the open-phase state and the rotor angle. And according to the rotor angle, the synthetic current angle, the rotor speed and the torque demand, calculating a demand phase current value of the motor in the open-phase state. And controlling a motor controller according to the required phase current value. According to the motor open-phase operation control method and device, the motor controller and the electric drive assembly, stable operation of the motor under the open-phase fault can be guaranteed.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a method and device for controlling the phase loss operation of a motor, a motor controller, and an electric drive assembly. Background Art

[0002] Permanent magnet motors control the phase and amplitude of each phase current by controlling the switching of power devices to achieve the purpose of controlling the direction and size of torque. Affected by the process, materials, manufacturing dispersion of components, integrated manufacturing process, operating conditions, ambient temperature, operating time, etc., some electronic devices may fail, resulting in failure of some phase control.

[0003] Under the existing technology, when one phase of control fails, the motor is controlled to enter a safe mode to prevent the motor from outputting unexpected torque and prevent personal injury. However, under the existing technology, once the safe mode is entered, the motor as a power source cannot provide power, which may cause the vehicle to break down or the equipment to shut down, which may easily cause user complaints and lead to secondary safety accidents in extreme cases.

[0004] Therefore, it is necessary to provide an improved motor missing-phase operation control method, device, motor controller and electric drive assembly to solve the above problems. Summary of the invention

[0005] The present application provides a motor phase-loss operation control method, device, motor controller and electric drive assembly that can ensure stable operation of the motor under a phase-loss fault.

[0006] The present application discloses a method for controlling the operation of a motor with a phase loss, comprising:

[0007] Obtaining the phase loss state, torque requirement, rotor angle and rotor speed of the motor;

[0008] Calculating a synthetic current angle according to the phase loss state and the rotor angle;

[0009] Calculating a required phase current value of the motor in a phase-loss state according to the rotor angle, the synthetic current angle, the rotor speed and the torque requirement;

[0010] The motor controller is controlled according to the required phase current value.

[0011] Further, controlling the motor controller according to the required phase current value includes:

[0012] Collecting actual phase current values ​​of the motor;

[0013] Performing a PI adjustment operation according to the difference between the required phase current value and the actual phase current value to obtain an adjusted phase voltage;

[0014] generating a pulse width modulation signal according to the regulated phase voltage,

[0015] The motor controller is controlled according to the pulse width modulation signal.

[0016] Further, the calculating the required phase current value of the motor in the phase-loss state according to the rotor angle, the synthetic current angle, the rotor speed and the torque demand includes:

[0017] According to the included angle between the rotor angle and the synthetic current angle, a first coefficient is obtained by calculation or table lookup;

[0018] According to the rotor speed, a second coefficient is obtained by calculation or table lookup;

[0019] Calculating a required composite current according to the first coefficient, the second coefficient and the torque requirement of the motor;

[0020] The required phase current value is calculated according to the required composite current.

[0021] Further, the calculating the required synthetic current according to the first coefficient, the second coefficient and the torque requirement of the motor includes:

[0022] Obtaining a preliminary current according to the first coefficient, the second coefficient and the torque requirement of the motor;

[0023] Perform current signal processing on the preliminary current to obtain the required synthetic current.

[0024] Furthermore, the current signal processing of the preliminary current includes: filtering and limiting the preliminary current.

[0025] Furthermore, the motor is a three-phase permanent magnet synchronous motor, and the motor controller includes a three-phase bridge arm, and the midpoint of each phase of the three-phase bridge arm is respectively used to connect one phase winding of the three-phase winding of the motor.

[0026] Furthermore, two groups of power devices are arranged on each phase bridge arm of the three-phase bridge arm, and the motor controller is controlled according to the pulse width modulation signal, including:

[0027] The power device is controlled to be turned on or off according to the pulse width modulation signal.

[0028] The present application also discloses a motor phase-loss operation control device, comprising:

[0029] A detection module, used to detect the phase loss state of the motor;

[0030] An acquisition module, used to obtain the torque requirement, rotor angle and rotor speed of the motor;

[0031] A calculation module, used to calculate the composite current angle of the motor, and calculate the required phase current value of the motor when the motor is running in a phase-loss state according to the rotor angle, the composite current angle, the rotor speed and the torque demand;

[0032] A control module is used to control the motor controller according to the required phase current value.

[0033] The present application also discloses a motor controller, including a control chip, wherein the control chip stores a computer program, and the computer program is used to implement the above method.

[0034] The present application also discloses an electric drive assembly, including a motor and the motor controller as described above.

[0035] The motor missing-phase operation control method, device, motor controller and electric drive assembly of the present application calculate the composite current angle of the motor in the missing-phase state, and calculate the required phase current value according to the rotor angle, composite current angle, rotor speed and torque demand, and control the motor controller according to the obtained required phase current value to adjust the remaining phase current. This method enables the motor to continue to operate in the missing-phase state, improves the availability of the motor in the missing-phase state and the stability and safety of driving. At the same time, it is helpful to control the motor to be as close to the normal operating state as possible in the missing-phase state, and improve the quality of the motor's missing-phase operation.

[0036] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0038] Figure 1 It is a flow chart of the motor missing-phase operation control method of the present application.

[0039] Figure 2 It is a schematic diagram of the structure of the electric drive assembly of the present application.

[0040] Figure 3 It is a schematic diagram of current synthesis in the phase-loss state of the present application.

[0041] Figure 4 It is a flowchart of step S300 of the present application.

[0042] Figure 5is a schematic diagram of calculating the required composite current in step S300.

[0043] Figure 6 It is a schematic diagram of the angle θ in step S310 of the present application.

[0044] Figure 7 It is a flowchart of step S400 of the present application.

[0045] Figure 8 yes Figure 7 Control diagram of .

[0046] Fig. 9 It is a schematic diagram of the synthetic current and torque of the motor of the present application under the control of phase loss operation.

[0047] Fig.10 It is a schematic diagram of the motor phase loss operation control device of the present application. DETAILED DESCRIPTION

[0048] Here, the technical solutions in the embodiments (or "implementations") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0050] Next, the embodiments of this specification are described in detail.

[0051] like Figure 1 As shown, the present application provides a motor missing-phase operation control method, comprising the following steps:

[0052] Step S100 , obtaining the phase loss state, torque requirement, rotor angle and rotor speed of the motor 10 .

[0053] like Figure 2As shown, the motor 10 of the present application is a three-phase permanent magnet synchronous motor, including three-phase windings A, B, and C. The motor 10 operates under the control of the motor controller 20. The motor controller 20 receives direct current from the power battery 30, converts the direct current into three-phase alternating current and provides it to the three-phase windings of the motor 10, and adjusts the frequency and amplitude of the three-phase current to drive the motor 10.

[0054] The motor controller 20 includes an inverter circuit 21, and the two ends of the inverter circuit 21 are respectively connected to the positive electrode and the negative electrode of the power battery 30. The inverter circuit 21 includes a three-phase bridge arm, and the midpoint of each phase of the three-phase bridge arm is used to connect one phase of the three-phase winding of the motor, and the two ends of each phase bridge arm are respectively connected to the two ends of the bus capacitor C and the two ends of the load 211.

[0055] Two groups of power devices are arranged on each phase arm of the three-phase bridge arm. Among them, the bridge arm corresponding to A is provided with power devices S1 and S2, the bridge arm corresponding to B is provided with power devices S3 and S4, and the bridge arm corresponding to C is provided with power devices S5 and S6. The connection point of the two groups of power devices in each phase bridge arm is the output end corresponding to the phase bridge arm.

[0056] The motor controller 20 may send a control signal to the power device to control the on / off state of the power device. In some embodiments, the motor controller 20 may control the on / off state of the power device through a pulse width modulation (PWM) signal, convert the DC power output by the power battery 30 into AC power and then supply power to the motor 10, and control the voltage and current of the output AC power by adjusting the duty cycle of the pulse width modulation signal, thereby controlling the output torque, speed, etc. of the motor 10.

[0057] When the drive system of the motor 10 is normal, the sum of the three-phase current output by the motor 10 is always zero, and the amplitudes of the three-phase currents are basically equal. When the motor 10 has a phase failure, the steady-state value of the sum of the three-phase current output by the motor 10 is still always zero, but the current of the phase with the phase failure is the smallest and approaches zero, and the imbalance of the three-phase current will become relatively large. In order to make the motor 10 continue to run smoothly in the phase failure state, it is necessary to obtain the required phase current value of the motor 10 in the phase failure state.

[0058] The motor phase loss operation control method of the present application is applicable to the case where any phase of the three phases has a phase loss fault, and the phase loss fault is caused by failure of the power device or its drive circuit. Specifically, in this embodiment, phase A has a phase loss fault.

[0059] The torque demand is the target torque value that the motor 10 needs to output, which is usually calculated or specified by the motor controller 20 according to the operating state and load requirements of the motor 10. The rotor angle is the angular position of the rotor of the motor 10 relative to the stator, which is usually detected by a rotor position sensor.

[0060] Step S200: Calculate a synthetic current angle according to the phase loss state and the rotor angle.

[0061] The composite current is the vector composite of the three-phase currents calculated based on the phase loss state and the rotor angle of the motor 10. When a phase loss fault occurs in phase A, the current of phase A approaches zero, and the composite current is the vector composite of the currents of phases B and C.

[0062] Figure 3 FIG. 1 shows a schematic diagram of current synthesis in a phase-loss state, assuming that phase A has a phase-loss fault. RMS1 and I RMS2 is the composite current under different states, I B1 and I B2 is the B phase current under different states, I C1 and I C2 is the C phase current under different states. In the phase-loss state, the magnitude and direction of the currents of phases B and C satisfy Kirchhoff's first principle, that is, the magnitude of the current of phase B and the current of phase C are equal and the direction is opposite. And the composite current value I RMS With each phase current value I B ,I C Satisfies the following formula:

[0063] I RMS =2*I B *cos(π / 6)=2*I C *cos(π / 6).

[0064] Step S300: Calculate the required phase current value I of the motor 10 in the phase-loss state according to the rotor angle, the synthetic current angle, the rotor speed and the torque requirement. B,cmd with I C,cmd .

[0065] Required phase current value I B,cmd with I C,cmd It is the current value that needs to be actually controlled during the motor's phase-loss operation control process.

[0066] Furthermore, if Figure 4 and Figure 5 As shown, step S300 also includes the following steps:

[0067] Step S310: Calculate or look up a table to obtain a first coefficient K1 according to the angle θ between the rotor angle and the composite current angle.

[0068] like Figure 6 As shown, the angle θ reflects the angle of the rotor D axis (or Q axis) relative to the direction of the synthetic current, which is used to determine the magnetic field direction and current regulation of the motor 10. The first coefficient K1 reflects the relationship between the motor torque and the motor magnetic field and the synthetic current I RMS The relative relationship between them.

[0069] In some cases, the first coefficient K1 may also be obtained by calculation or table lookup based on the included angle between the rotor angle and a certain phase.

[0070] Step S320: Calculate or look up a table to obtain a second coefficient K2 according to the rotor speed.

[0071] The second coefficient K2 reflects the motor torque, speed and synthetic current I RMS relative relationship.

[0072] Step S330: Calculate the required composite current I according to the first coefficient K1, the second coefficient K2 and the torque requirement of the motor 10. rms_req .

[0073] Required synthetic current I rms_req is the ideal current for driving the motor 10 to achieve the torque requirement.

[0074] Furthermore, step S330 further includes:

[0075] Step S331: Obtain a preliminary current I according to the first coefficient K1, the second coefficient K2 and the torque requirement of the motor 10. rms .

[0076] Initial current I rms It is the basis for further processing of the current and is used to obtain the final required phase current in subsequent calculations and adjustments.

[0077] Step S332: the initial current I rms Process the current signal to obtain the required synthetic current I rms_req .

[0078] Among them, the initial current I rms The current signal processing includes: rms By filtering and limiting the initial current I rms Filtering can effectively remove noise or instantaneous fluctuations. rms Limiting can prevent the demand current from exceeding the safe range of the operation of the motor 10.

[0079] For the initial current I rmsThe current signal processing can ensure the stability and reliability of the current signal under the motor phase loss operation control, thereby improving the stability and safety of the motor 10.

[0080] Step S340: synthesize current I according to demand rms_req , calculate the required phase current value I B,cmd with I C,cmd .

[0081] It can be understood that the required phase current value I B,cmd with I C,cmd It is the demand current value of the remaining two phases. The demand composite current value I rms_req The required phase current value I B,cmd ,I C,cmd The following relationship needs to be satisfied:

[0082] I rms_req =2*I B,cmd *cos(π / 6)=2*I C,cmd *cos(π / 6).

[0083] Step S400: According to the required phase current value I B,cmd ,I C,cmd The motor controller 20 is controlled.

[0084] Furthermore, if Figure 7 and Figure 8 As shown, step S400 also includes the following steps:

[0085] Step S410: Collect the actual phase current value I of the motor 10 B,fdb ,I C,fdb .

[0086] It can be understood that the actual phase current value I B,fdb ,I C,fdb It is the actual phase current value of the remaining two phases. B,fdb ,I C,fdb Usually measured by a current sensor.

[0087] Step S420: According to the required phase current value I B,cmd ,I C,cmd The actual phase current value I B,fdb ,I C,fdb The difference between the phase voltage V B,des 、V C,des .

[0088] The regulating phase voltage V of the regulating motor 10 is calculated by PI regulation operation. B,des 、V C,des, so as to correct the phase current of the motor 10 so that the actual phase current value I B,fdb ,I C,fdb As close as possible to the required phase current value I B,cmd ,I C,cmd , thereby compensating for the current deviation caused by phase loss.

[0089] Step S430: Adjust the phase voltage V B,des 、V C,des , generating a pulse width modulated signal.

[0090] Step S440 , controlling the motor controller 20 according to the pulse width modulation signal.

[0091] The calculated regulated phase voltage value V B,des 、V C,des Converted into a pulse width modulated signal so as to be used to control the input of the motor controller 20, control the voltage applied to the winding of the motor 10, and further adjust the actual power and current to compensate for the impact of the phase loss on the operation of the motor 10 and achieve better performance of the motor 10 in the phase loss state.

[0092] Wherein, controlling the motor according to the pulse width modulation signal includes: controlling the power device to turn on or off according to the pulse width modulation signal. When the pulse width modulation signal is at a high level (or a conduction signal), the power device is turned on to allow current to pass. When the pulse width modulation signal is at a low level (or a shutdown signal), the power device is turned off to prevent current from passing.

[0093] Fig. 9 The resultant current I of the motor 10 under the phase loss operation control is shown in FIG. RMS And torque diagram. Among them, the synthetic current I RMS The frequency is the same as the torque fluctuation frequency of the motor 10.

[0094] like Fig.10 As shown, the present application also provides a motor phase loss operation control device, comprising:

[0095] The detection module is used to detect the phase loss state of the motor 10.

[0096] The acquisition module is used to obtain the torque requirement, rotor angle and rotor speed of the motor 10.

[0097] A calculation module is used to calculate the composite angle of the motor 10, and calculate the required phase current value I of the motor 10 when the motor 10 is running in the phase loss mode according to the rotor angle, the composite current angle, the rotor speed and the torque demand. B,cmd with I C,cmd .

[0098] Control module, used to adjust the phase current value I according to the demand B,cmd with I C,cmd The controller 20 controls the motor 10 .

[0099] The present application also provides a motor controller, including a control chip, wherein the control chip stores a computer program, and the computer program is used to implement the above-mentioned motor missing-phase operation control method.

[0100] The present application also provides an electric drive assembly, including a motor and the motor controller as described above.

[0101] The motor phase loss operation control method, device, motor controller and electric drive assembly of the present application calculate the required phase current value of the motor in the phase loss state, and adjust and control the motor controller after calculating the difference between the required phase current value and the actual phase current value, so that the motor can continue to operate in the phase loss state, thereby improving the availability of the motor in the phase loss state and the stability and safety of driving. At the same time, by using PI adjustment, the control accuracy is improved, which is conducive to controlling the motor in the phase loss state to be as close to the normal operating state as possible, and improving the phase loss operation quality of the motor. In addition, the motor phase loss operation control method of the present application is simple and direct to control, can quickly adjust the current, and does not require the addition of additional sensors, and is low in cost.

[0102] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A method for controlling the operation of a motor with missing phase, characterized in that: include: Obtaining the phase loss state, torque requirement, rotor angle and rotor speed of the motor; Calculating a synthetic current angle according to the phase loss state and the rotor angle; Calculating a required phase current value of the motor in a phase-loss state according to the rotor angle, the synthetic current angle, the rotor speed and the torque requirement; The motor controller is controlled according to the required phase current value.

2. The motor missing-phase operation control method according to claim 1, characterized in that: The controlling the motor controller according to the required phase current value comprises: Collecting actual phase current values ​​of the motor; Performing a PI adjustment operation according to the difference between the required phase current value and the actual phase current value to obtain an adjusted phase voltage; generating a pulse width modulation signal according to the regulated phase voltage; The motor controller is controlled according to the pulse width modulation signal.

3. The motor missing-phase operation control method according to claim 1, characterized in that: The step of calculating the required phase current value of the motor in a phase-loss state according to the rotor angle, the synthetic current angle, the rotor speed and the torque requirement includes: According to the included angle between the rotor angle and the synthetic current angle, a first coefficient is obtained by calculation or table lookup; According to the rotor speed, a second coefficient is obtained by calculation or table lookup; Calculating a required composite current according to the first coefficient, the second coefficient and the torque requirement of the motor; The required phase current value is calculated according to the required composite current.

4. The motor missing-phase operation control method according to claim 3 is characterized in that: The step of calculating the required synthetic current according to the first coefficient, the second coefficient and the torque requirement of the motor includes: Obtaining a preliminary current according to the first coefficient, the second coefficient and the torque requirement of the motor; Perform current signal processing on the preliminary current to obtain the required synthetic current.

5. The motor missing-phase operation control method according to claim 4, characterized in that: The performing current signal processing on the preliminary current includes: filtering and limiting the preliminary current.

6. The motor missing-phase operation control method according to claim 2, characterized in that: The motor is a three-phase permanent magnet synchronous motor, and the motor controller includes a three-phase bridge arm, wherein the midpoint of each phase of the three-phase bridge arm is respectively used to connect one phase winding of the three-phase winding of the motor.

7. The motor missing-phase operation control method according to claim 6, characterized in that: Two groups of power devices are arranged on each phase bridge arm of the three-phase bridge arm, and the motor controller is controlled according to the pulse width modulation signal, including: The power device is controlled to be turned on or off according to the pulse width modulation signal.

8. A motor missing phase operation control device, characterized in that: include: A detection module, used to detect the phase loss state of the motor; An acquisition module, used to obtain the torque requirement, rotor angle and rotor speed of the motor; A calculation module, used to calculate the composite current angle of the motor, and calculate the required phase current value of the motor when the motor is running in a phase-loss state according to the rotor angle, the composite current angle, the rotor speed and the torque demand; The control module is used to control the motor controller according to the required phase current value.

9. A motor controller, characterized in that: The method comprises a control chip storing a computer program, wherein the computer program is used to implement the method according to any one of claims 1 to 7.

10. An electric drive assembly, characterized in that: The invention comprises a motor and a motor controller as claimed in claim 9.

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