Motor control method, device, apparatus and storage medium

Abstract

The application discloses a motor control method and device, equipment and storage medium, and relates to the technical field of electromagnetism. The method comprises the following steps: acquiring ammeter data and voltmeter data; obtaining a duty cycle according to the ammeter data, the voltmeter data, a torque command and a reduced speed; and adjusting the running state of the motor based on the duty cycle. The method adopts a feedforward compensation voltage table lookup method, improves the robustness of current loop control, and accelerates the response capability of the current. The method uses the reduced speed for table lookup, reduces the calibration of the motor, and adopts a direct calculation error voltage method to obtain more accurate control current, thereby improving the efficiency and output capability of the control motor.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of electromagnetic technology, and in particular to a motor control method, device, equipment and storage medium. BACKGROUND

[0002] Permanent magnet synchronous motor is a kind of high efficiency, high power density motor type, widely used in electric vehicles, industrial automation and household appliances and other fields.

[0003] In the related art, the feed-forward voltage is calculated by using fixed motor parameters or table lookup calculation without considering the motor internal resistance and the differential term in the stator voltage equation, and the permanent magnet synchronous motor is controlled by using the feed-forward voltage. In the above method, since the motor parameters will change with the running state of the motor, using fixed motor parameters to calculate the feed-forward voltage will cause the problem of inaccurate feed-forward voltage.

[0004] In the related art, the current table of the permanent magnet synchronous motor is obtained by calibration under the premise that the bus voltage utilization rate and the overmodulation coefficient are determined. When the bus voltage utilization rate or the overmodulation coefficient changes, the permanent magnet synchronous motor needs to be calibrated again to obtain a new current table. The above method results in a lot of workload when calibrating the motor, occupies human resources and equipment resources, and also delays the progress of project development.

[0005] In the related art, when the current loop control is performed, the PI operation is performed on the phase voltage and the current bus voltage, and the command current is obtained by table lookup according to the operation result. In the above method, the parameters of the PI operation need to be adjusted in the PI regulation process, and the response speed of the PI regulation is slow. SUMMARY

[0006] Embodiments of the present application provide a motor control method, device, equipment and storage medium. The technical solutions provided by the embodiments of the present application are as follows:

[0007] According to an aspect of the embodiments of the present application, a motor control method is provided, and the method comprises:

[0008] obtaining current table data and voltage table data, the current table data comprising at least one reference current, the voltage table data comprising at least one feed-forward compensation voltage, the current table data and the voltage table data being generated based on calibration data, the calibration data being recorded in the process of calibrating the motor;

[0009] According to the ammeter data, the voltmeter data, a torque command and a converted speed, a duty cycle is obtained, the duty cycle is used to adjust an operation state of the motor, the torque command is used to control an output torque of the motor, the converted speed is obtained by converting a speed of the motor at a first time according to a phase voltage, a bus voltage and a converted bus voltage, the bus voltage is used to provide a direct current voltage, the converted bus voltage is obtained according to the bus voltage, a bus voltage utilization rate and an overmodulation coefficient, the bus voltage utilization rate is used to indicate a usage degree of the bus voltage, and the phase voltage is a magnitude of three-phase alternating current voltage input to the motor;

[0010] Based on the duty cycle, an operation state of the motor is adjusted.

[0011] In some embodiments, according to the torque command and the converted speed, a lookup table current is obtained by querying the ammeter data, the lookup table current is a reference current under the converted speed and the torque command;

[0012] According to the torque command and the converted speed, a lookup table voltage is obtained by querying the voltmeter data, the lookup table voltage is a feedforward compensation voltage under the converted speed and the torque command;

[0013] Based on a feedback current and the lookup table current, a target voltage is calculated, the feedback current is an actual current in the motor at the first time;

[0014] Based on the lookup table voltage, the target voltage is adjusted to obtain an adjusted target voltage;

[0015] Based on the adjusted target voltage, the duty cycle is calculated.

[0016] In some embodiments, the calibration data includes at least one set of working condition point data, the working condition point data includes a speed, a torque, a command current and a command voltage; the ammeter data is obtained by interpolating the speed, the torque and the command current in at least one set of working condition point data in the calibration data; and the voltmeter data is obtained by interpolating the speed, the torque and the command voltage in at least one set of working condition point data in the calibration data.

[0017] In some embodiments, the overmodulation coefficient includes a first modulation coefficient and a second modulation coefficient, the first overmodulation coefficient is an overmodulation coefficient used in a calibration process, and the second overmodulation coefficient is an overmodulation coefficient used by the motor when overmodulation is performed;

[0018] The bus voltage of the motor at the first time is obtained.

[0019] The bus voltage is converted based on the bus voltage, the bus voltage utilization rate, the first over-modulation coefficient and the second over-modulation coefficient to obtain a converted bus voltage.

[0020] The phase voltage of the motor at the first time point is obtained.

[0021] An error voltage is obtained based on the phase voltage and the converted bus voltage.

[0022] A converted voltage is obtained by adding the converted bus voltage and the error voltage.

[0023] The converted speed is obtained based on the converted voltage.

[0024] In some embodiments, the target voltage includes a first-axis voltage and a second-axis voltage, which are components of the target voltage in different directions; the phase voltage is determined based on the first-axis voltage and the second-axis voltage at a second time point, which is earlier than the first time point.

[0025] In some embodiments, the speed of the motor at the first time point is obtained.

[0026] The converted speed is calculated based on a bus calibration voltage, the converted voltage and the speed, wherein the bus calibration voltage is a reference DC voltage used in the calibration process.

[0027] According to an aspect of an embodiment of the present application, a motor control device is provided, which is characterized in that the device includes:

[0028] A table data obtaining module is configured to obtain current table data and voltage table data, the current table data including at least one reference current, and the voltage table data including at least one feed-forward compensation voltage, the current table data and the voltage table data being generated based on calibration data recorded in a calibration process of a motor;

[0029] A duty cycle calculating module is configured to obtain a duty cycle based on the current table data, the voltage table data, a torque command and a converted speed, the duty cycle being used to adjust an operating state of the motor, the torque command being used to control an output torque of the motor, and the converted speed being obtained by converting a speed of the motor at a first time point based on a phase voltage of the motor at the first time point, a bus voltage and a converted bus voltage, the bus voltage being used to provide a DC voltage, and the converted bus voltage being obtained based on the bus voltage, a bus voltage utilization rate and an over-modulation coefficient, the bus voltage utilization rate being used to indicate a usage degree of the bus voltage, and the phase voltage being an amplitude of a three-phase AC voltage input to the motor.

[0030] a motor control module configured to adjust an operating state of the motor based on the duty ratio.

[0031] In some embodiments, the duty ratio calculation module is further configured to query a table current from the current table data according to the torque command and the converted rotational speed, the table current being a reference current at the torque command and the converted rotational speed.

[0032] query a table voltage from the voltage table data according to the torque command and the converted rotational speed, the table voltage being a feed-forward compensation voltage at the torque command and the converted rotational speed.

[0033] perform a PI operation on a feedback current and the table current to obtain a target voltage, the feedback current being an actual current in the motor at the first time;

[0034] adjust the target voltage based on the table voltage to obtain an adjusted target voltage;

[0035] calculate the duty ratio based on the adjusted target voltage.

[0036] In some embodiments, the calibration data includes at least one set of working condition point data, the working condition point data including rotational speed, torque, command current, and command voltage; the current table data is obtained by interpolating the rotational speed, torque, and command current in the at least one set of working condition point data in the calibration data; and the voltage table data is obtained by interpolating the rotational speed, torque, and command voltage in the at least one set of working condition point data in the calibration data.

[0037] In some embodiments, the over-modulation coefficient includes a first over-modulation coefficient and a second over-modulation coefficient, the first over-modulation coefficient being an over-modulation coefficient used in a calibration process, and the second over-modulation coefficient being an over-modulation coefficient used by the motor in over-modulation operation; and the apparatus further includes a converted rotational speed calculation module configured to obtain a bus voltage of the motor at the first time.

[0038] obtain a converted bus voltage based on the bus voltage, the bus voltage utilization rate, the first over-modulation coefficient, and the second over-modulation coefficient.

[0039] obtain a phase voltage of the motor at the first time.

[0040] obtain an error voltage based on the phase voltage and the converted bus voltage.

[0041] add the converted bus voltage and the error voltage to obtain a converted voltage.

[0042] The converted voltage is obtained based on the converted voltage.

[0043] In some embodiments, the target voltage includes a first-axis voltage and a second-axis voltage, the first-axis voltage and the second-axis voltage being component voltages of the target voltage in different directions; the converted voltage calculation module is further configured to determine the phase voltage based on the first-axis voltage and the second-axis voltage at a second time point, the second time point being earlier than the first time point.

[0044] In some embodiments, the converted speed calculation module is configured to obtain a first speed of the motor at the first time point.

[0045] The converted speed is obtained based on a bus calibration voltage, the converted voltage, and the first speed, the bus calibration voltage being a reference DC voltage used in the calibration process.

[0046] According to an aspect of some embodiments of the present application, a control device is provided, which includes a processor and a memory, the memory storing a computer program, the computer program being loaded and executed by the processor to implement the motor control method described above.

[0047] According to an aspect of some embodiments of the present application, a computer readable storage medium is provided, which stores a computer program, the computer program being loaded and executed by a processor to implement the motor control method described above.

[0048] According to an aspect of some embodiments of the present application, a computer program product is provided, which includes a computer program, the computer program being loaded and executed by a processor to implement the motor control method described above.

[0049] The technical solutions provided by the embodiments of the present application have at least the following beneficial effects:

[0050] By directly looking up the table, the feed-forward voltage compensation value under any operating condition is accurately obtained, and then the air-occupied ratio for controlling the operating state of the motor is obtained, which realizes more accurate control of the control current, improves the efficiency of the motor, and also improves the response speed of the current loop, and thus improves the torque response capability.

[0051] Secondly, by converting the speed using the bus voltage utilization rate and the over-modulation coefficient, the motor current table data is obtained according to the converted speed, without the need to recalibrate the motor current table, which saves manpower, equipment resources, and also speeds up the project development progress.

[0052] In addition, by directly calculating the error voltage, when the current loop control point is not on the voltage limit circle, the current command value can be automatically adjusted quickly and accurately to make the current loop current control point fall on the voltage limit circle, while the output torque remains unchanged. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 is a schematic diagram of a scheme implementation environment provided by an embodiment of the present application;

[0054] Figure 2 is a flowchart of a motor control method provided by an embodiment of the present application;

[0055] Figure 3 is a schematic diagram of a current table lookup provided by an embodiment of the present application;

[0056] Figure 4 is a schematic diagram of a voltage table lookup provided by an embodiment of the present application;

[0057] Figure 5 is a flowchart of a voltage command generation provided by an embodiment of the present application;

[0058] Figure 6 is a block diagram of a motor control device provided by an embodiment of the present application;

[0059] Figure 7 is a structural schematic diagram of a control device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0061] Reference should be made to Figure 1 which shows a schematic diagram of a scheme implementation environment provided by an embodiment of the present application. The implementation environment can include: a control device 10 and a motor 20. Wherein, the control device 10 is electrically connected with the motor 20.

[0062] The control device 10 is configured to precisely control the operation of the motor 20. In some embodiments, the control device 10 controls the start, stop, acceleration, deceleration and reversal of the motor 20 by adjusting the rotational speed and torque of the motor 20. In some embodiments, the control device 10 can be any one of a motor controller, a powertrain control unit (PCU), a powertrain control module (PCM), a vehicle control unit (VCU), etc., or any other device configured to control the operation of the motor 20, which is not limited in the present application.

[0063] The motor 20 is configured to convert electrical energy into mechanical energy to provide driving force for machines and systems. The machines and systems can be any one of an electric vehicle, an automated system, a household appliance, etc. In the embodiments of the present application, the motor 20 is a permanent magnet synchronous motor (PMSM). The permanent magnet synchronous motor generates a constant magnetic field through a permanent magnet, which interacts with the magnetic field generated by the current in the stator winding to generate torque.

[0064] The electrical connection refers to the electrical contact and current transmission path established between electrical devices or components through cables, wires or other conductive materials. The electrical connection can be a circuit connection or a wireless connection, which is not limited in the present application. If the electrical connection is a circuit connection, the connection method can be a cable connection, and if the electrical connection is a wireless connection, the connection method can be infrared connection, wireless local area network and WiFi (Wireless Fidelity) network connection. In the embodiments of the present application, the electrical connection is not limited.

[0065] Please refer to Figure 2 which shows a flowchart of the motor control method provided by an embodiment of the present application. The method can include at least one of the following steps 210-230:

[0066] In step 210, current table data and voltage table data are obtained. The current table data includes at least one reference current, and the voltage table data includes at least one feedforward compensation voltage. The current table data and the voltage table data are generated based on calibration data recorded in the process of calibrating the motor.

[0067] The current table data, which can also be referred to as a current table, is a table including reference currents of the motor under different operating conditions. The reference currents refer to currents at which the motor is expected to operate to ensure that the motor operates according to expected performance and response requirements. The reference currents include D-axis reference currents and Q-axis reference currents. In some embodiments, the current table is an equal speed interval, equal torque interval current table. The voltage table data, which can also be referred to as a voltage table, is a table including feedforward compensation voltages of the motor under different operating conditions. The feedforward compensation voltages are used for feedforward control to compensate for known disturbances or nonlinear factors in the system in advance in the voltage control loop. The feedforward compensation voltages include D-axis feedforward compensation voltages and Q-axis feedforward compensation voltages. In some embodiments, the voltage table is an equal speed interval, equal torque interval voltage table. The operating conditions refer to working states and parameters of a machine or device under different operating environments, which can include but are not limited to speed, torque, current, voltage, etc., and embodiments of the present application are not limited thereto.

[0068] The D-axis and the Q-axis are coordinate systems used for motor control vector control, the D-axis is perpendicular to the magnetic field, and the Q-axis is perpendicular to the rotor flux. It can be understood that the current / voltage on the D-axis is a direct current / voltage component, and the current / voltage on the Q-axis is an alternating current / direct voltage component.

[0069] In some embodiments, the calibration data includes at least one set of operating point data, the operating point data including speed, torque, command current, and command voltage; the current table data is obtained by interpolating the speed, torque, and command current in at least one set of operating point data in the calibration data; and the voltage table data is obtained by interpolating the speed, torque, and command voltage in at least one set of operating point data in the calibration data.

[0070] The operating point data refers to operating parameters of the motor under a specified operating condition. The speed refers to the rotational speed of the motor rotor and can be expressed in revolutions per minute (RPM). For example, 1000 RPM means that the motor rotor rotates 1000 times per minute. The torque refers to the torque output by the motor and can be expressed in Newton-meters (Nm). For example, 5 Nm means that a force of 5 Newtons acts on a force arm of 1 meter. The command current refers to the current theoretically generated by the motor under corresponding speed and torque during the calibration of the motor. The command current includes D-axis command current and Q-axis command current. The command voltage refers to the voltage theoretically generated by the motor under corresponding speed and torque during the calibration of the motor. The command voltage includes D-axis command voltage and Q-axis command voltage.

[0071] Motor calibration refers to a process of accurately setting and calibrating parameters of a motor to ensure that the motor can work in an accurate and reliable manner.

[0072] In some embodiments, based on the preset bus calibration voltage, the MTPA (Maximum Torque Per Ampere) and MTPV (Maximum Torque Per Voltage) curves of the motor at different rotating speeds are calibrated to obtain at least one working condition point data.

[0073] The MTPA curve describes the maximum torque that the motor can output at a given current. The purpose is to achieve maximum torque output by minimizing current at different rotating speeds. The MTPV curve describes the maximum torque that the motor can achieve at a given voltage. The purpose is to achieve maximum torque output by optimizing voltage at different rotating speeds.

[0074] Interpolation is a method for estimating unknown data between known data. Alternatively, any of the following methods can be used for interpolation: linear interpolation, polynomial interpolation, spline interpolation, etc., or other methods, which are not limited by the embodiments of the present application.

[0075] The above-mentioned method records calibration data during the calibration of the voltage, generates a current table and a voltage table based on the calibration data, does not increase the workload of motor calibration, and obtains more accurate feedforward voltage, which can significantly improve the control performance of the current loop.

[0076] In step 220, the duty cycle is obtained according to the current table data, the voltage table data, the torque command and the converted rotating speed. The duty cycle is used to adjust the running state of the motor, the torque command is used to control the output torque of the motor, and the converted rotating speed is obtained by converting the rotating speed of the motor at the first time according to the phase voltage, the bus voltage and the converted bus voltage. The bus voltage is used to provide a direct current voltage, and the converted bus voltage is obtained according to the bus voltage, the bus voltage utilization rate and the overmodulation coefficient. The bus voltage utilization rate is used to indicate the use degree of the bus voltage, and the phase voltage is the amplitude of the input three-phase alternating current voltage of the motor.

[0077] The torque command is an instruction indicating the expected torque output by the motor. In some embodiments, the corresponding torque command is generated according to the input information and the motor feedback information. The input information refers to the external input indicating information. For example, in an electric vehicle, the corresponding torque command is generated according to the input of the driver (such as the position of the accelerator pedal). For example, the corresponding torque command is generated according to the input of the operator to the industrial equipment (such as handling, assembly, etc.). The motor feedback information refers to the actual output torque or rotating speed of the motor.

[0078] The first time refers to the corresponding time of the torque command. The first time can refer to the time when the motor motion state needs to be changed for the last time.

[0079] The converted rotating speed is obtained by converting and standardizing the rotating speed of the motor at the first time.

[0080] The duty cycle is a pulse width modulation (PWM) signal used to adjust the rotating speed and torque of the motor.

[0081] In some embodiments, the step 220 further comprises steps 221-225.

[0082] In step 221, the table lookup current is obtained from the current table data according to the torque command and the converted rotating speed, the table lookup current being a reference current under the converted rotating speed and the torque command.

[0083] The table lookup current comprises a D-axis table lookup current and a Q-axis table lookup current.

[0084] For example, refer to Figure 3 which shows a schematic diagram of current table lookup provided by an embodiment of the present application, the table lookup current I dRef , I qRef at the first time being obtained by querying the current table according to the converted rotating speed Spd c at the first time and the torque command Tq Ref .

[0085] In step 222, the table lookup voltage is obtained from the voltage table data according to the torque command and the converted rotating speed, the table lookup voltage being a feedforward compensation voltage under the converted rotating speed and the torque command.

[0086] The table lookup voltage comprises a D-axis table lookup voltage and a Q-axis table lookup voltage.

[0087] For example, refer to Figure 4 which shows a schematic diagram of voltage table lookup provided by an embodiment of the present application, the table lookup voltage U dFw , U qdFw at the first time being obtained by querying the voltage table according to the converted rotating speed Spd c at the first time and the torque command Tq Ref .

[0088] In step 223, the target voltage is obtained by performing PI operation on the feedback current and the table lookup current, the feedback current being the actual current in the motor at the first time.

[0089] The feedback current refers to an actual current of the motor measured at a first time, including a D-axis feedback current and a Q-axis feedback current. Optionally, the control device 10 further includes a current measurement component for measuring the current of the motor. Optionally, the current measurement component can be a current sensor or other electronic component for measuring the current, and the embodiments of the present application do not limit this.

[0090] In some embodiments, the feedback current includes the D-axis feedback current and the Q-axis feedback current, and the target voltage is obtained by performing a PI (Proportional-Integral) operation on the difference between the D-axis feedback current and the Q-axis feedback current in the feedback current and the D-axis lookup table current and the Q-axis lookup table current in the lookup table current, respectively.

[0091] In the above manner, the output proportion of the current loop is small by using the feedforward compensation voltage lookup table, so that the PI regulation burden of the current loop is reduced, the PI control is more stable, the current fluctuation is reduced, the control output torque ripple is smaller, the sensitivity of the current loop to the PI parameters is reduced, the PI parameters of each control condition are easier to adjust, and the robustness of the control system is higher.

[0092] In step 224, the target voltage is adjusted based on the lookup table voltage to obtain an adjusted target voltage.

[0093] Adjusting the target voltage is also voltage compensation, and the lookup table voltage is used to compensate the target voltage to obtain the final target voltage.

[0094] For example, the lookup table voltage U dFw , U qFw is added to the target voltage U dPI , U qPI to obtain the adjusted target voltage U dRef , U qRef , that is:

[0095] U dRef = U aFw + U aPI

[0096] U qRef = U qFw + U qPI

[0097] In step 225, the duty cycle is calculated based on the adjusted target voltage.

[0098] In some embodiments, the control device 10 further comprises a SVPWM (Space Vector Pulse Width Modulation) component; the target voltage is inversely transformed to obtain a transformed target voltage; and the transformed target voltage is input into the SVPWM component to obtain a duty ratio.

[0099] In some embodiments, the target voltage is optimized to obtain an optimized target voltage under a phase voltage clipping value. The phase voltage clipping value is a maximum value of the voltage of the motor.

[0100] At step 230, the operating state of the motor is adjusted based on the duty ratio.

[0101] In some embodiments, the control device 10 further comprises a PWM wave generating component; and the power device of the motor is controlled by the PWM wave generating component based on the duty ratio. By adjusting the power device of the motor, the power output, speed and torque of the motor are controlled.

[0102] In summary, the method provided by the embodiments of the present application directly obtains the feedforward voltage compensation value under any operating condition by direct table lookup, and then obtains the duty ratio for controlling the operating state of the motor, thereby achieving more accurate control of the control current, improving the efficiency of the motor, and improving the response speed of the current loop and the ability of torque response.

[0103] Secondly, by using the bus voltage utilization rate and the overmodulation coefficient to fold the speed, the current table data of the motor is obtained according to the folded speed, without the need to recalibrate the motor current table, thereby saving manpower, equipment resources and speeding up the project development progress.

[0104] In addition, by directly calculating the error voltage, when the current loop control point is not on the voltage limit circle, the control current command value can be automatically adjusted quickly and accurately, so that the current loop current control point falls on the voltage limit circle, and the output torque can be guaranteed to remain unchanged.

[0105] The following is a way of calculating the folded speed.

[0106] Please refer to Figure 5 which shows a flowchart of the voltage command generation provided by an embodiment of the present application, in Figure 5 the process of voltage command generation and the process of closed-loop control are shown.

[0107] In some embodiments, the overmodulation coefficient includes a first modulation coefficient and a second modulation coefficient, the first overmodulation coefficient is an overmodulation coefficient used in the calibration process, and the second overmodulation coefficient is an overmodulation coefficient used by the motor when overmodulation operation; obtain the bus voltage of the motor at the first time; based on the bus voltage, the bus voltage utilization rate, the first overmodulation coefficient and the second overmodulation coefficient, obtain the converted bus voltage; obtain the phase voltage of the voltage at the first time; based on the phase voltage and the converted bus voltage, obtain the error voltage; the value obtained by adding the converted bus voltage and the error voltage is determined as the converted voltage; based on the converted voltage, obtain the converted speed.

[0108] The bus voltage is used to provide a direct current voltage for the control device 10 to drive the control device 10 to operate. In some embodiments, the control device 10 further includes a voltage measurement component for measuring the bus voltage of the control device 10. Optionally, the voltage measurement component can be a voltage sensor or a voltage meter, or other electronic components for measuring the bus voltage, and the embodiments of the present application do not make examples of this. The bus voltage utilization rate is a pre-set expected bus voltage utilization rate, which ensures that the actual bus voltage meets the expected conditions. In some embodiments, the bus voltage utilization rate satisfies the utilization rate value range. For example, the utilization rate value range of the bus voltage utilization rate is 0.95-1.

[0109] The first overmodulation coefficient is an overmodulation coefficient set by a related technical personnel when the motor current table is calibrated. The second overmodulation coefficient is an overmodulation coefficient set by a related technical personnel when the motor needs to operate in overmodulation.

[0110] In some embodiments, based on the bus voltage utilization rate, the bus voltage is first converted to obtain the initially converted bus voltage; based on the first overmodulation coefficient and the second overmodulation coefficient, the initially converted bus voltage is second converted to obtain the finally converted bus voltage.

[0111] For example, the utilization rate of the bus voltage is K, the value range of K is 0.95-1, and the current bus voltage U n is converted using the following formula based on the bus voltage utilization rate K to obtain the initially converted bus voltage U c1 :

[0112] U c1 = U n *K

[0113] Then, using the first overmodulation coefficient C1 and the second overmodulation coefficient C2, the initially converted bus voltage U c1 is converted using the following formula to obtain the finally converted bus voltage U c2 :

[0114]

[0115] The above method converts the bus voltage by using the bus voltage utilization rate and the over-modulation coefficient to obtain a converted bus voltage, calculates a converted rotating speed based on the converted bus voltage, and further obtains the current meter data of the motor, without recalibrating the motor current meter, thereby saving manpower and equipment resources and accelerating the project development progress.

[0116] In some embodiments, the target voltage includes a first-axis voltage and a second-axis voltage, the first-axis voltage and the second-axis voltage being component voltages of the target voltage in different directions; the phase voltage is determined based on the first-axis voltage and the second-axis voltage at a second time point, the second time point being earlier than the first time point.

[0117] The first-axis voltage and the second-axis voltage respectively refer to the D-axis feedforward compensation voltage and the Q-axis feedforward compensation voltage. It can be understood that the first-axis voltage can be the D-axis feedforward compensation voltage or the Q-axis feedforward compensation voltage, and the corresponding second-axis voltage can be the Q-axis feedforward compensation voltage or the D-axis feedforward compensation voltage.

[0118] The second time point refers to the time point of the last adjustment of the motor operating state. That is, the phase voltage is determined based on the first-axis voltage and the second-axis voltage of the last adjustment of the motor. The phase voltage refers to the voltage between a single phase line and a neutral point.

[0119] Exemplarily, the phase voltage U s The following formula can be used for calculation:

[0120]

[0121] wherein, U′ dRef represents the first-axis voltage at the second time point, U′ qRef represents the second-axis voltage at the second time point.

[0122] After the converted bus voltage and the phase voltage are calculated, the error voltage at the first time point is determined based on the converted bus voltage and the phase voltage.

[0123] Exemplarily, the error voltage U e The calculation method is as follows:

[0124]

[0125] wherein, U c2 is the converted bus voltage, U s is the phase voltage.

[0126] When the temperature of the motor changes, the motor has poor consistency, or the motor permanent magnet magnetic steel demagnetizes, etc., the current loop current control point will fall inside or outside the voltage limit circle. When the current loop current control point falls inside the voltage limit circle, the control efficiency is low, and the bus voltage utilization rate is reduced. When the current loop current control point falls outside the voltage limit circle, the current loop control is easy to saturate, causing the system to oscillate, and the motor output torque has large pulsation.

[0127] The above-mentioned mode can automatically adjust the control current command value when the current loop current control point is not on the voltage limit circle, so that the current loop current control point falls on the voltage limit circle, while the output torque remains unchanged.

[0128] Compared with the prior art, the above-mentioned mode adopts a method of directly calculating the error voltage U e , which can quickly feedback to the input end of the current lookup table and obtain accurate control current. Therefore, the present application not only can output accurate control current according to the voltage limit circle, but also has faster response speed and does not need to calibrate related parameters.

[0129] According to the converted bus voltage U c2 and the error voltage U e , the converted voltage U c can be calculated, and the calculation method is as follows:

[0130] U c = U c2 + U e

[0131] In some embodiments, the first speed of the motor at the first time is obtained; and the converted speed is calculated according to the bus calibration voltage, the converted voltage and the first speed, wherein the bus calibration voltage refers to the reference voltage used in the calibration process.

[0132] Exemplarily, the converted voltage U c can be used to calculate the converted speed Spd c , and the calculation method is as follows:

[0133]

[0134] Wherein, U dc is the calibration bus voltage, and Spd is the first speed at the first time.

[0135] When the current loop control needs to run in the overmodulation region, the amplitude limiting value U s of the phase voltage U sLim needs to be calculated, and the calculation method is as follows:

[0136]

[0137] The following is an embodiment of the device of the present application, which can be used to execute the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0138] Please refer to Figure 6 , which shows a block diagram of a motor control device according to an embodiment of the present application. The device has the functions of the above-mentioned motor control method examples, which can be realized by hardware or by executing corresponding software by hardware. The device can be the control equipment introduced above, or can be arranged in the control equipment. As Figure 6 shown, the device 600 can include a table data acquisition module 610, a duty ratio calculation module 620, and a motor control module 630.

[0139] The table data acquisition module 610 is configured to acquire current table data and voltage table data, the current table data including at least one reference current, and the voltage table data including at least one feed-forward compensation voltage, the current table data and the voltage table data being generated based on calibration data recorded in the process of calibrating the motor.

[0140] The duty ratio calculation module 620 is configured to obtain a duty ratio based on the current table data, the voltage table data, a torque command, and a converted rotational speed, the duty ratio being used to adjust the running state of the motor, the torque command being used to control the output torque of the motor, the converted rotational speed being obtained by converting the rotational speed of the motor at a first time based on a phase voltage, a bus voltage, and a converted bus voltage at the first time, the bus voltage being used to provide a direct current voltage, the converted bus voltage being obtained based on the bus voltage, a bus voltage utilization rate, and an over-modulation coefficient, the bus voltage utilization rate being used to indicate the usage degree of the bus voltage, and the phase voltage being the amplitude of the input three-phase alternating current voltage of the motor.

[0141] The motor control module 630 is configured to adjust the running state of the motor based on the duty ratio.

[0142] In some embodiments, the duty ratio calculation module 620 is further configured to query a lookup table current from the current table data based on the torque command and the converted rotational speed, the lookup table current being a reference current under the converted rotational speed and the torque command.

[0143] query a lookup table voltage from the voltage table data based on the torque command and the converted rotational speed, the lookup table voltage being a feed-forward compensation voltage under the converted rotational speed and the torque command.

[0144] The target voltage is obtained by performing proportional-integral (PI) operation on the feedback current and the lookup table current, the feedback current being an actual current in the motor at the first time;

[0145] The target voltage is adjusted based on the lookup table voltage to obtain an adjusted target voltage;

[0146] The duty cycle is calculated based on the adjusted target voltage.

[0147] In some embodiments, the calibration data includes at least one set of operating point data, the operating point data including a rotational speed, a torque, a command current, and a command voltage; the current table data is obtained by interpolating the rotational speed, the torque, and the command current in the at least one set of operating point data in the calibration data; and the voltage table data is obtained by interpolating the rotational speed, the torque, and the command voltage in the at least one set of operating point data in the calibration data.

[0148] In some embodiments, the overmodulation coefficient includes a first overmodulation coefficient and a second overmodulation coefficient, the first overmodulation coefficient being an overmodulation coefficient used in a calibration process, and the second overmodulation coefficient being an overmodulation coefficient used by the motor in overmodulation operation; and the apparatus further includes a converted rotational speed calculation module configured to obtain a bus voltage of the motor at the first time.

[0149] The converted bus voltage is obtained based on the bus voltage, the bus voltage utilization rate, the first overmodulation coefficient, and the second overmodulation coefficient.

[0150] A phase voltage of the motor at the first time is obtained.

[0151] An error voltage is obtained based on the phase voltage and the converted bus voltage.

[0152] A converted voltage is determined by adding the converted bus voltage and the error voltage.

[0153] The converted rotational speed is obtained based on the converted voltage.

[0154] In some embodiments, the target voltage includes a first-axis voltage and a second-axis voltage, the first-axis voltage and the second-axis voltage being component voltages of the target voltage in different directions; and the converted voltage calculation module is further configured to determine the phase voltage based on a first-axis voltage and a second-axis voltage at a second time, the second time being earlier than the first time.

[0155] In some embodiments, the converted rotational speed calculation module is configured to obtain a first rotational speed of the motor at the first time.

[0156] According to the bus calibration voltage, the conversion voltage and the first rotating speed, the conversion rotating speed is calculated, and the bus calibration voltage refers to a reference direct current voltage used in the calibration process.

[0157] In summary, the method provided by the embodiments of the present application can accurately obtain the feed-forward voltage compensation value under any working condition by direct table lookup, and then obtain the space factor used for controlling the running state of the motor, so as to realize more accurate control of the control current, improve the efficiency of the motor, and also improve the response speed of the current loop, thereby improving the torque response capability.

[0158] Secondly, by converting the rotating speed by using the bus voltage utilization rate and the overmodulation coefficient, the current table data of the motor is obtained according to the conversion rotating speed, so that the motor current table does not need to be recalibrated, manpower and equipment resources are saved, and the project development progress is also accelerated.

[0159] In addition, by directly calculating the error voltage, when the current loop control point is not on the voltage limit circle, the control current command value can be automatically adjusted quickly and accurately, so that the current loop current control point falls on the voltage limit circle, and the output torque can be guaranteed to remain unchanged.

[0160] It should be noted that the device provided in the above embodiments is only used as an example to divide the above functional modules in realizing its functions, and in actual application, the above functions can be completed by different functional modules according to actual needs, that is, the content structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0161] As for the device in the above embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0162] Please refer to Figure 7 which shows a structure schematic diagram of the control device 700 provided by an embodiment of the present application. The control device 700 can be used to execute the method steps in the above embodiments. The control device 700 can include a processor 701 and a memory 702. The processor 701 is used to realize the functions of each module in the above device embodiments.

[0163] The processor 701 includes one or more than one processing core. The processor 701 executes various functional applications and information processing by running software programs and modules.

[0164] The memory 702 can be connected to the processor 701.

[0165] The memory 702 can be used to store a computer program executed by the processor 701, and the processor 701 is configured to execute the computer program to implement the motor control method described above.

[0166] In addition, the memory 702 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: a magnetic or optical disk, an electrically erasable programmable read-only memory, an erasable programmable read-only memory, a static random access memory, a read-only memory, a magnetic storage, a flash memory, and a programmable read-only memory.

[0167] For details not described in the above embodiments, refer to the description in the method embodiments above, which will not be repeated here.

[0168] The embodiments of the present application also provide a computer readable storage medium, the storage medium stores a computer program, and the computer program is used to be executed by a processor to implement the motor control method described above. Optionally, the computer readable storage medium can include: a ROM (Read-Only Memory), a RAM (Random-Access Memory), a SSD (Solid State Drives) or an optical disc, etc. Wherein, the random access memory can include a ReRAM (Resistance Random Access Memory) and a DRAM (Dynamic Random Access Memory).

[0169] The embodiments of the present application also provide a computer program product, the computer program product includes a computer program, the computer program is stored in a computer readable storage medium, and a processor reads and executes the computer program from the computer readable storage medium to implement the motor control method described above.

[0170] It should be understood that "multiple" mentioned herein refers to two or more. "And / or", which describes the association relationship of the associated objects, means that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. The character " / " generally represents that the associated objects before and after it are in an "or" relationship.

[0171] "Greater than or equal to" mentioned herein can mean greater than or equal to, and "less than or equal to" can mean less than or equal to.

[0172] In addition, the step numbers described herein only exemplarily show a possible execution sequence between steps, and in some other embodiments, the above steps can also be executed in a sequence different from the numbers, such as two steps with different numbers being executed at the same time, or two steps with different numbers being executed in a sequence opposite to the illustration, which is not limited in the embodiments of the present application.

[0173] The above only exemplarily describes the embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor control method, characterized in that, The method includes: Acquire ammeter data and voltmeter data, wherein the ammeter data includes at least one reference current and the voltmeter data includes at least one feedforward compensation voltage, and the ammeter data and the voltmeter data are generated based on calibration data, which is recorded during the calibration of the motor; Obtain the bus voltage of the motor at a first moment, where the first moment is the moment when the motor's motion state was most recently changed; Based on the bus voltage, bus voltage utilization rate, first overmodulation coefficient, and second overmodulation coefficient, the converted bus voltage is obtained. The bus voltage is used to provide DC voltage, the bus voltage utilization rate is used to indicate the degree of utilization of the bus voltage, the first overmodulation coefficient is the overmodulation coefficient used in the calibration process, and the second overmodulation coefficient is the overmodulation coefficient used by the motor during overmodulation operation. Obtain the phase voltage of the motor at the first moment, where the phase voltage refers to the amplitude of the three-phase AC voltage input to the motor; Based on the phase voltage and the converted bus voltage, the error voltage is obtained; The value obtained by adding the converted bus voltage and the error voltage is determined as the converted voltage; Obtain the motor speed at the first moment; The calculated rotational speed is obtained based on the calculated voltage and the calculated rotational speed. The duty cycle is obtained based on the ammeter data, the voltmeter data, the torque command, and the calculated speed. The duty cycle is used to adjust the operating state of the motor, and the torque command is used to control the output torque of the motor. The operating state of the motor is adjusted based on the duty cycle.

2. The method according to claim 1, characterized in that, The step of obtaining the duty cycle based on the ammeter data, the voltmeter data, the torque command, and the calculated speed includes: Based on the torque command and the converted speed, the lookup current is obtained from the ammeter data. The lookup current refers to the reference current under the converted speed and the torque command. Based on the torque command and the converted speed, the lookup voltage is obtained from the voltmeter data. The lookup voltage refers to the feedforward compensation voltage under the converted speed and the torque command. After performing a proportional-integral (PI) operation on the feedback current and the lookup current, the target voltage is obtained. The feedback current refers to the actual current in the motor at the first moment. Based on the lookup table voltage, the target voltage is adjusted to obtain the adjusted target voltage; The duty cycle is calculated based on the adjusted target voltage.

3. The method according to claim 1, characterized in that, The calibration data includes at least one set of operating point data, which includes speed, torque, command current, and command voltage; the ammeter data is obtained by interpolating the speed, torque, and command current in the at least one set of operating point data in the calibration data; the voltmeter data is obtained by interpolating the speed, torque, and command voltage in the at least one set of operating point data in the calibration data.

4. The method according to claim 1, characterized in that, The step of obtaining the phase voltage of the motor at the first moment includes: Based on the target voltage at the second moment, the phase voltage is determined. The target voltage at the second moment includes a first axis voltage and a second axis voltage. The first axis voltage and the second axis voltage are the component voltages of the target voltage at the second moment in different directions. The second moment is earlier than the first moment.

5. The method according to claim 1, characterized in that, The process of obtaining the converted speed based on the converted voltage and the speed includes: The equivalent rotational speed is calculated based on the bus calibration voltage, the equivalent voltage, and the rotational speed. The bus calibration voltage refers to the reference DC voltage used in the calibration process.

6. A motor control device, characterized in that, The device includes: The meter data acquisition module is used to acquire ammeter data and voltmeter data. The ammeter data includes at least one reference current, and the voltmeter data includes at least one feedforward compensation voltage. The ammeter data and the voltmeter data are generated based on calibration data, which is recorded during the calibration of the motor. The duty cycle calculation module is used to obtain the motor's bus voltage at a first moment, which is the moment when the motor's operating state was most recently changed; based on the bus voltage, bus voltage utilization rate, first overmodulation coefficient, and second overmodulation coefficient, a converted bus voltage is obtained. The bus voltage is used to provide DC voltage, the bus voltage utilization rate is used to indicate the degree of bus voltage utilization, the first overmodulation coefficient is the overmodulation coefficient used during calibration, and the second overmodulation coefficient is the overmodulation coefficient used by the motor during overmodulation operation; the module also obtains the phase voltage of the motor at the first moment, which refers to the amplitude of the three-phase AC voltage input to the motor; based on the phase voltage and the converted bus voltage, an error voltage is obtained; the value obtained by adding the converted bus voltage and the error voltage is determined as the converted voltage; the module also obtains the motor's speed at the first moment; based on the converted voltage and the speed, a converted speed is obtained; and based on the ammeter data, the voltmeter data, the torque command, and the converted speed, the duty cycle is obtained. The duty cycle is used to adjust the motor's operating state, and the torque command is used to control the motor's output torque. The motor control module is used to adjust the operating state of the motor based on the duty cycle.

7. A control device, characterized in that, The control device includes a processor and a memory, the memory storing a computer program, which is loaded and executed by the processor to implement the method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that is executed by a processor to implement the method as described in any one of claims 1 to 5.

9. A computer program product, characterized in that, The computer program product includes a computer program that is loaded and executed by a processor to implement the method as described in any one of claims 1 to 5.

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