A motor control method, device, apparatus and storage medium

Abstract

The application discloses a motor control method, device, equipment and storage medium, the method comprises: obtaining the first phase of the voltage instruction at the current sampling point; determining the second phase of the voltage instruction at the next sampling point; determining that the first voltage polarity and the second voltage polarity are different based on the first phase and the second phase, and determining the zero point phase; determining the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero point phase; and controlling the opening and closing of the inverter switch based on the duty cycle of the switch signal. In this way, by predicting the second phase of the voltage instruction at the next sampling point according to the first phase of the voltage instruction at the current sampling point, determining the zero point phase, and then determining the duty cycle of the inverter switch signal, when the switch is controlled based on the duty cycle, the switch state can be changed in time when the voltage instruction passes through the zero point position, the low-frequency harmonic of the alternating current motor phase current is reduced, and the motor loss is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to motor control technology, and particularly relates to a motor control method, device, equipment and storage medium. BACKGROUND

[0002] Modern alternating current motors are generally driven by a plurality of pulse width modulation (PWM) inverters, specifically, the direct current voltage input into the inverter is converted into alternating current voltage output by opening and closing the inverter switch multiple times in a fundamental period of the motor, and the controller in the motor drives the alternating current motor based on the alternating current voltage. However, when the motor speed is high, the fundamental frequency corresponding to the alternating current motor is increased, and the fundamental period is reduced. When the inverter switch frequency is not increased, the number of switchings in a fundamental period is reduced, which can easily lead to the inverter not being able to accurately turn on and turn off at the zero crossing point of the voltage command, and further lead to the generation of low-frequency harmonics or low-frequency oscillation in the phase current, causing motor loss. SUMMARY

[0003] To solve the above technical problems, the embodiments of the present application expect to provide a motor control method, device, equipment and storage medium.

[0004] The technical scheme of the present application is implemented as follows:

[0005] In a first aspect, a method for remotely accessing a serial port device is provided, applied to a second electronic device, and the method comprises:

[0006] obtaining a first phase of a voltage command at a current sampling point;

[0007] determining a second phase of the voltage command at a next sampling point based on the first phase;

[0008] determining whether a first voltage polarity at the current sampling point and a second voltage polarity at the next sampling point are the same based on the first phase and the second phase;

[0009] determining a zero point phase based on the first phase and the second phase when the first voltage polarity and the second voltage polarity are different;

[0010] determining a duty cycle of an inverter switch signal based on the first phase, the second phase and the zero point phase;

[0011] controlling opening and closing of the inverter switch based on the duty cycle of the switch signal.

[0012] In the scheme, the determining whether the first voltage polarity of the current sampling point and the second voltage polarity of the next sampling point are same based on the first phase and the second phase comprises: if the first phase is less than a zero reference phase and the second phase is greater than the zero reference phase, determining that the first voltage polarity and the second voltage polarity are different; otherwise, determining that the first voltage polarity and the second voltage polarity are same.

[0013] In the scheme, the method further comprises: determining that the first voltage polarity and the second voltage polarity are same, and controlling the inverter switch to keep the current state.

[0014] In the scheme, the determining the zero phase based on the first phase and the second phase comprises: if the first phase is less than a first zero reference phase and the second phase is greater than the first zero reference phase, taking the first zero reference phase as the zero phase; or, if the first phase is less than a second zero reference phase and the second phase is greater than the second zero reference phase, taking the second zero reference phase as the zero phase.

[0015] In the scheme, the zero phase is the first zero reference phase, and the determining the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero phase comprises: calculating an absolute value of a difference between the first phase and the zero phase to obtain a first absolute value; calculating an absolute value of a difference between the first phase and the second phase to obtain a second absolute value; and calculating a ratio of the first absolute value and the second absolute value as the duty cycle of the switch signal.

[0016] In the scheme, the zero phase is the second zero reference phase, and the determining the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero phase comprises: calculating an absolute value of a difference between the second phase and the zero phase to obtain a third absolute value; calculating an absolute value of a difference between the first phase and the second phase to obtain a fourth absolute value; and calculating a ratio of the third absolute value and the fourth absolute value as the duty cycle of the switch signal.

[0017] In the scheme, the obtaining the first phase of the voltage instruction at the current sampling point comprises: obtaining a current motor rotor position angle and an initial phase of the voltage instruction; and calculating a sum of the current motor rotor position angle and the initial phase as the first phase of the voltage instruction at the current sampling point.

[0018] In the scheme, the determining the second phase of the voltage instruction at the next sampling point based on the first phase comprises: obtaining a motor speed and a sampling period of a motor controller; calculating a product of the motor speed and the sampling period to determine a phase difference between the first phase and the second phase; and determining the second phase based on the phase difference and the first phase.

[0019] In a second aspect, a motor control device is provided, and the device comprises:

[0020] a obtaining module configured to obtain a first phase of a voltage instruction at a current sampling point;

[0021] a processing module configured to determine a second phase of the voltage instruction at a next sampling point based on the first phase;

[0022] The processing module is further configured to determine whether a first voltage polarity at the current sampling point and a second voltage polarity at the next sampling point are the same based on the first phase and the second phase.

[0023] The processing module is further configured to determine that the first voltage polarity and the second voltage polarity are different, and determine a zero point phase based on the first phase and the second phase.

[0024] The processing module is further configured to determine a duty cycle of an inverter switch signal based on the first phase, the second phase and the zero point phase.

[0025] The processing module is further configured to control opening and closing of the inverter switch based on the duty cycle of the switch signal.

[0026] In a third aspect, an electronic device is provided, and the device comprises a processor and a memory configured to store a computer program capable of running on the processor, wherein the processor is configured to execute the steps of the foregoing method when running the computer program.

[0027] In a fourth aspect, a computer storage medium is provided, and the computer storage medium stores a computer program, wherein the computer program is executed by a processor to implement the steps of the foregoing method.

[0028] The present application discloses a motor control method, which predicts a second phase of a voltage instruction at a next sampling point based on a first phase of the voltage instruction at a current sampling point, determines a zero point phase, and then determines a duty cycle of an inverter switch signal, so that when the switch is controlled based on the duty cycle, the switch state can be changed in time when the voltage instruction passes through the zero point position, the low-frequency harmonic of the alternating current motor phase current is reduced, and the motor loss is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Schematic diagram of the voltage command crossing zero points between adjacent sampling points in an embodiment of the present application.

[0030] Figure 2 This is a schematic diagram of a first flow chart of a motor control method in an embodiment of the present application;

[0031] Figure 3 This is a first schematic diagram of the voltage crossing zero between sampling points in an embodiment of the present application;

[0032] Figure 4 This is a second schematic diagram of the voltage crossing zero between sampling points in an embodiment of the present application;

[0033] Figure 5 This is a second flow chart of the motor control method in an embodiment of the present application;

[0034] Figure 6 This is a schematic diagram of the structure of the motor control device in an embodiment of the present application;

[0035] Figure 7 Schematic diagram of the structure of the electronic device in the embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below with reference to the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present application.

[0037] In the prior art, when the motor speed is high, the fundamental frequency of the AC motor increases and the fundamental period decreases. When the inverter switching frequency is not increased, the number of switches in one fundamental period will decrease, which may easily lead to the inverter not being able to accurately turn on and off at the zero crossing point of the voltage command. For example, Figure 1 Schematic diagram of the voltage instruction crossing zero between adjacent sampling points in the embodiment of the present application. Figure 1 As shown in the figure, in a motor drive inverter, when six-step control is adopted, ideally, when the voltage command (voltage reference value) is greater than 0, the inverter switch signal should be in the on state, and when the voltage reference value is less than 0, the switch signal should be in the off state, that is, the switch signal should accurately cross the zero point of the voltage reference value. However, in actual control, the voltage reference value may pass through the zero point between two sampling points. If the switch is controlled according to a fixed switching frequency, the switch will not be able to operate before the next sampling point arrives, resulting in a delay of ΔT in the actual turn-off time. In this case, the on time of the inverter switch is longer than the off time. Due to the asymmetry of the switching time, a DC voltage bias is generated in the voltage command, resulting in low-frequency harmonic oscillation in the phase current.

[0038] To solve the problem that the switch cannot switch the switch state in time when the voltage instruction is zero, a motor control method is provided. Figure 2 The first flowchart of the motor control method in the embodiment of the application is shown.

[0039] As shown in Figure 2 The motor control method can specifically include:

[0040] Step 201: Obtain the first phase of the voltage instruction at the current sampling point;

[0041] Here, the voltage instruction can be a voltage reference value, based on which the inverter is instructed to convert DC voltage into AC voltage output through multiple switching, and based on which the output AC voltage is used to drive the AC motor.

[0042] Here, sampling is used to collect the voltage instruction at a preset sampling frequency, which can be performed by a motor controller. The current sampling point can be determined based on the preset sampling frequency (or sampling period). In actual application, the sampling frequency (or sampling period) can be determined according to the fundamental frequency of the voltage instruction. For example, in some embodiments, the sampling frequency is 4 times the fundamental frequency.

[0043] For example, in some embodiments, the first phase of the voltage instruction at the current sampling point is obtained by: obtaining the current motor rotor position angle and the initial phase of the voltage instruction; calculating the sum of the current motor rotor position angle and the initial phase as the first phase of the voltage instruction at the current sampling point.

[0044] For example, in actual application, the current motor rotor position angle can be determined based on a detection sensor of the motor rotor position. For example, in actual application, the initial phase of the voltage instruction can be a preset initial phase.

[0045] Step 202: Determine the second phase of the voltage instruction at the next sampling point based on the first phase;

[0046] Here, determining the second phase of the voltage instruction at the next sampling point based on the first phase can be understood as predicting the second phase of the voltage instruction at the next sampling point based on the first phase. For example, the first phase of the voltage instruction corresponding to the current sampling point, the motor speed and the sampling period / sampling period can be used to predict the second phase corresponding to the next sampling point.

[0047] Exemplarily, in some embodiments, determining the second phase of the voltage command at the next sampling point based on the first phase includes: obtaining the motor speed and the sampling period of the motor controller; calculating the product of the motor speed and the sampling period to determine the phase difference between the first phase and the second phase; and determining the second phase based on the phase difference and the first phase.

[0048] Exemplarily, the first phase and the second phase corresponding to the voltage instructions of other phases may also be obtained through the steps in steps 201 and 202 .

[0049] Here, the motor controller can periodically collect the voltage command based on the sampling period. In practical applications, the sampling timing can be achieved through a carrier timer.

[0050] Step 203: Based on the first phase and the second phase, determine whether the first voltage polarity at the current sampling point is the same as the second voltage polarity at the next sampling point;

[0051] Here, the polarity of the voltage can be determined by the phase of the voltage. For example, in actual applications, the voltage command is a sinusoidal AC voltage, the voltage command phase is at (0, π), indicating that the voltage polarity is positive, the voltage command phase is at (π, 2π), indicating that the voltage polarity is negative, and when the voltage command phase is 0 or π, it indicates that the voltage command crosses zero.

[0052] Exemplarily, in some embodiments, judging whether the first voltage polarity of the current sampling point and the second voltage polarity of the next sampling point are the same based on the first phase and the second phase includes: if the first phase is less than the zero reference phase and the second phase is greater than the zero reference phase, determining that the first voltage polarity and the second voltage polarity are different; otherwise, determining that the first voltage polarity and the second voltage polarity are the same.

[0053] Exemplarily, in an actual application, the voltage command is a sinusoidal AC voltage, and the zero-point reference phase is 0 or π. The above-mentioned "if the first phase is less than the zero-point reference phase and the second phase is greater than the zero-point reference phase, determining that the first voltage polarity and the second voltage polarity are different" includes: if the first phase is less than 0 and the second phase is greater than 0; or, if the first phase is less than π and the second phase is greater than π, determining that the first voltage polarity and the second voltage polarity are different.

[0054] The first phase is equal to a zero-point reference phase, representing that the voltage command passes zero point at the current sampling point. Illustratively, in some embodiments, the method further comprises: the first phase is equal to the zero-point reference phase, controlling the inverter switch to change state from the current on / off state to the off / on state.

[0055] The second phase is equal to the zero-point reference phase, representing that the voltage command passes zero point at the next sampling point. Illustratively, in some embodiments, the method further comprises: the second phase is equal to the zero-point reference phase, controlling the inverter switch to change state from the current on / off state to the off / on state at the next sampling point.

[0056] Step 204: determining that the first voltage polarity and the second voltage polarity are different, and determining a zero-point phase based on the first phase and the second phase;

[0057] Here, determining that the first voltage polarity and the second voltage polarity are different represents that the voltage command passes zero point between the current sampling point and the next sampling point, and the state of the inverter switch needs to be switched between the current sampling point and the next sampling point. It should be noted that in the present application, the number of times that the voltage command passes zero point between the current sampling point and the next sampling point is 0 or 1. In actual application, if the number of times that the voltage command passes zero point between two adjacent sampling points is more than 1, the sampling period can be adjusted so that the voltage command does not pass zero point or passes zero point once between two adjacent sampling points, thereby using the technical solution of the present application.

[0058] Illustratively, in some embodiments, the determination of the zero-point phase based on the first phase and the second phase comprises: the first phase is less than a first zero-point reference phase, and the second phase is greater than the first zero-point reference phase, and the first zero-point reference phase is taken as the zero-point phase; or, the first phase is less than a second zero-point reference phase, and the second phase is greater than the second zero-point reference phase, and the second zero-point reference phase is taken as the zero-point phase.

[0059] Illustratively, the first zero-point reference phase can be π, and the second zero-point reference phase can be 0.

[0060] Step 205: determining a duty cycle of the inverter switch signal based on the first phase, the second phase and the zero-point phase;

[0061] Here, the inverter switching signal controls the inverter's switch on or off. The switching signal's duty cycle represents the ratio of the time the switch is in the on and off states within a switching cycle. In practical applications, the switching signal's duty cycle can also be expressed as the ratio of the time the switch is in the on state within a switching cycle to the switching period. Here, the switching period is a preset switching period, which is preset based on the sampling period and is generally equal to the switching period plus the sampling period.

[0062] Here, the zero-point phase represents the phase of the voltage command when it passes through the zero point. In practical applications, the zero-point phase can be 0 or π.

[0063] For example, Figure 3 This is a first schematic diagram of the voltage crossing zero between sampling points in the embodiment of the present application. Figure 3 As shown, the zero point phase is π, the first phase α1 is less than π, and the second phase α2 is greater than π. When the voltage command passes through the zero point, the voltage polarity changes from positive to negative. In order to ensure that the inverter switch state is accurately switched when the voltage command passes through the zero point, it is necessary to switch the inverter switch from the open state to the closed state when the voltage command passes through the zero point. In addition, Figure 3 In the example, the carrier timer is used to calculate the sampling period T S Determine each sampling point and perform sampling at the highest and lowest points of the carrier timer. Figure 3 The PWM in it means that the inverter switches are controlled by PWM modulation technology.

[0064] Exemplarily, in some embodiments, the zero-point phase is the first zero-point reference phase, and determining the duty cycle of the inverter switching signal based on the first phase, the second phase, and the zero-point phase includes: calculating the absolute value of the difference between the first phase and the zero-point phase to obtain a first absolute value; calculating the absolute value of the difference between the first phase and the second phase to obtain a second absolute value; and calculating the ratio of the first absolute value to the second absolute value as the duty cycle of the switching signal. Exemplarily, the first zero-point reference phase is π, that is, the zero-point phase is π.

[0065] For example, Figure 4 This is a second schematic diagram of the voltage crossing zero between sampling points in the embodiment of the present application. Figure 4 As shown, the zero point phase is 0, the first phase α1 is less than 0, and the second phase α2 is greater than 0. When the voltage command passes through the zero point, the voltage polarity changes from negative to positive. To ensure accurate switching of the inverter switch state when the voltage command passes through the zero point, it is necessary to switch the inverter switch from the off state to the on state when the voltage command passes through the zero point.

[0066] Exemplarily, in some embodiments, the zero-point phase is the second zero-point reference phase, and the determining the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero-point phase comprises: calculating an absolute value of a difference between the second phase and the zero-point phase to obtain a third absolute value; calculating an absolute value of a difference between the first phase and the second phase to obtain a fourth absolute value; and calculating a ratio of the third absolute value to the fourth absolute value as the duty cycle of the switch signal. Exemplarily, the second zero-point reference phase is 0, i.e., the zero-point phase is 0.

[0067] By determining the duty cycle of the switch signal based on the first phase, the second phase and the zero-point phase, the change of the inverter switch state at the zero-crossing position of the voltage command can be accurately performed, the low-frequency harmonic of the alternating current motor phase current can be reduced, and the energy flow between the motor side and the power supply side can be reduced, the conduction loss on the motor winding can be reduced, the core loss of the motor stator can be reduced, the risk of motor stator over-temperature and rotor demagnetization can be reduced.

[0068] Step 206: controlling the opening and closing of the inverter switch based on the duty cycle of the switch signal.

[0069] Here, the controlling the opening and closing of the inverter switch based on the duty cycle of the switch signal comprises: when the zero-point phase is the first zero-point reference phase, switching the inverter switch from the opening state to the closing state based on the duty cycle of the switch signal; or, when the zero-point phase is the second zero-point reference phase, switching the inverter switch from the closing state to the opening state based on the duty cycle of the switch signal.

[0070] Exemplarily, in some embodiments, the method further comprises: determining that the first voltage polarity and the second voltage polarity are the same, and controlling the inverter switch to maintain the current state.

[0071] It should be noted that in the embodiments of the present application, the number of zero-crossings of the voltage command between the current sampling point and the next sampling point is 0 or 1. Here, the first voltage polarity and the second voltage polarity being the same indicates that the voltage command does not cross zero between the sampling points, and the inverter state does not need to be switched between the sampling points.

[0072] Here, the execution subject of steps 201 to 206 can be a processor of a motor control device.

[0073] The technical scheme of the present application determines the zero phase of the voltage at the zero-crossing point between sampling points through the first phase of the voltage instruction at the current sampling point and the second phase at the next sampling point, and determines the duty cycle of the inverter switching signal through the first phase, the second phase and the zero phase, so that the inverter switching state can be accurately changed at the zero-crossing position of the voltage instruction, the low-frequency harmonic of the alternating current motor phase current can be reduced, and the motor loss can be reduced.

[0074] In order to better reflect the purpose of the present application, further example explanations are made on the basis of the embodiments of the present application. Figure 5 The second flowchart of the motor control method in the embodiments of the present application is shown.

[0075] As shown in Figure 5 , the motor control method can specifically include:

[0076] Step 501: obtaining the first phase of the voltage instruction at the current sampling point;

[0077] Here, obtaining the first phase of the voltage instruction at the current sampling point includes: obtaining the current motor rotor position angle and the initial phase of the voltage instruction; calculating the sum of the current motor rotor position angle and the initial phase as the first phase of the voltage instruction at the current sampling point.

[0078] The first phase α1 of the voltage instruction at the current sampling point can be obtained according to the motor rotor position angle θ re and the voltage vector phase angle θ v , wherein:

[0079] α1=θ th +θ v

[0080] Here, the voltage vector phase angle θ v is equivalent to the initial phase of the voltage instruction in the present application. In actual application, the current motor rotor position angle can be determined based on the detection sensor of the motor rotor position.

[0081] Step 502: determining the second phase of the voltage instruction at the next sampling point based on the first phase;

[0082] Specifically, the second phase α2 of the voltage instruction at the next sampling point can be obtained according to the first phase, the speed ω e of the motor and the sampling period T s of the controller, wherein:

[0083] α2=α1+ω e ·T s

[0084] The same method can be taken to determine the first phase and the second phase corresponding to the other phase voltage command of the AC motor.

[0085] Step 503: whether the voltage polarity of the current sampling point and the next sampling point is the same; if yes, step 504 is executed; if no, step 505 is executed.

[0086] Specifically, based on the first phase and the second phase, it is determined whether the first voltage polarity of the current sampling point and the second voltage polarity of the next sampling point are the same; if yes, step 504 is executed; if no, step 505 is executed.

[0087] Specifically, if the first phase is less than 0 and the second phase is greater than 0, or if the first phase is less than π and the second phase is greater than π, it is determined that the first voltage polarity and the second voltage polarity are different, and step 505 is executed; otherwise, step 504 is executed.

[0088] Step 504: it is determined that the first voltage polarity and the second voltage polarity are the same, and the inverter switch is controlled to remain in the current state.

[0089] It should be noted that in the embodiments of the present application, the number of voltage command zero-crossing points between the current sampling point and the next sampling point is 0 or 1. Here, the first voltage polarity and the second voltage polarity are the same, which means that the voltage command does not pass through the zero-crossing point between the sampling points, and the inverter switch state does not need to be switched between the sampling points.

[0090] Step 505: determining a zero-crossing phase based on the first phase and the second phase.

[0091] Specifically, the first phase is less than π and the second phase is greater than π, and π is taken as the zero-crossing phase; or the first phase is less than 0 and the second phase is greater than 0, and 0 is taken as the zero-crossing phase.

[0092] Step 506: determining the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero-crossing phase.

[0093] Specifically, when the zero-crossing phase is π, it indicates that when the voltage is at the zero-crossing phase, the voltage is converted from positive to negative, and the switch signal is initially in the on (on) position, and then when the voltage phase is equal to π, the switch needs to be turned off and be in the off (off) position. The duty cycle of the switch signal in this switch cycle can be obtained by the following formula: calculating the absolute value of the difference between the first phase and π to obtain a first absolute value; calculating the absolute value of the difference between the first phase and the second phase to obtain a second absolute value; calculating the ratio of the first absolute value to the second absolute value as the duty cycle of the switch signal.

[0094] Specifically, when the zero point phase is 0, it indicates that the voltage is converted from negative to positive at the zero point phase, and the switch signal is initially in the off position, and then the switch needs to be turned on when the voltage phase is equal to 0. The duty cycle of the switch signal in the switch cycle can be obtained by the following formula: calculating the absolute value of the difference between the second phase and 0 to obtain a third absolute value; calculating the absolute value of the difference between the first phase and the second phase to obtain a fourth absolute value; calculating the ratio of the third absolute value and the fourth absolute value as the duty cycle of the switch signal.

[0095] By determining the duty cycle of the switch signal based on the first phase, the second phase and the zero point phase, the change of the inverter switch state at the zero point position of the voltage command can be accurately performed, the low-frequency harmonics of the phase current of the alternating current motor can be reduced, and the energy flow between the motor side and the power side can be reduced. The conduction loss on the motor winding is reduced, and the core loss of the motor stator is reduced, the risk of motor stator over-temperature and rotor demagnetization is reduced.

[0096] Step 507: based on the duty cycle of the switch signal, control the opening and closing of the inverter switch.

[0097] Specifically, when the zero point phase is π, the inverter switch is switched from the on state to the off state based on the duty cycle of the switch signal; or, when the zero point phase is 0, the inverter switch is switched from the off state to the on state based on the duty cycle of the switch signal.

[0098] Here, the execution subject of steps 501 to 507 can be a processor of a motor control device.

[0099] The technical scheme of the present application determines the zero point phase of the phase voltage between the first phase at the current sampling point and the second phase at the next sampling point, and determines the duty cycle of the inverter switch signal through the first phase, the second phase and the zero point phase. The change of the inverter switch state at the zero point position of the voltage command can be accurately performed, the low-frequency harmonics of the phase current of the alternating current motor can be reduced, and the motor loss can be reduced. By keeping the inverter switch in the on or off state when the phase voltage does not pass through the zero point between the sampling points, the control of the inverter switch is realized.

[0100] For example, the motor control method can be used to solve the problem that the state switching of the inverter switch cannot be accurately performed at the zero crossing point of the voltage command in the six-step control of the motor drive inverter, causing the problem of low-frequency harmonic of the phase current. It should be noted that in the present embodiment, the number of zero crossing points between the current sampling point and the next sampling point of the voltage command is 0 or 1, that is, the voltage command does not cross zero between two adjacent sampling points or crosses zero once. In actual application, if the number of zero crossing points between two adjacent sampling points of the voltage command exceeds 1, the sampling period can be adjusted so that the voltage command does not cross zero or crosses zero once between two adjacent sampling points, thereby using the technical solution of the present application.

[0101] Figure 6 The present embodiment is a schematic diagram of the motor control device, which shows an implementation device of a motor control method. The device 60 specifically includes:

[0102] The acquisition module 601 is configured to acquire a first phase of the voltage command at the current sampling point.

[0103] The processing module 602 is configured to determine a second phase of the voltage command at the next sampling point based on the first phase.

[0104] The processing module 602 is further configured to determine whether the first voltage polarity at the current sampling point and the second voltage polarity at the next sampling point are the same based on the first phase and the second phase.

[0105] The processing module 602 is further configured to determine that the first voltage polarity and the second voltage polarity are different, and determine a zero crossing point based on the first phase and the second phase.

[0106] The processing module 602 is further configured to determine the duty cycle of the inverter switch signal based on the first phase, the second phase, and the zero crossing point.

[0107] The processing module 602 is further configured to control the opening and closing of the inverter switch based on the duty cycle of the switch signal.

[0108] In some embodiments, the processing module 602 is configured to determine that the first voltage polarity and the second voltage polarity are different if the first phase is less than a zero reference phase and the second phase is greater than the zero reference phase; otherwise, determine that the first voltage polarity and the second voltage polarity are the same.

[0109] In some embodiments, the processing module 602 is further configured to determine that the first voltage polarity and the second voltage polarity are the same, and control the inverter switch to maintain the current state.

[0110] In some embodiments, when the first phase is less than a first zero reference phase and the second phase is greater than the first zero reference phase, the first zero reference phase is taken as the zero phase; or, when the first phase is less than a second zero reference phase and the second phase is greater than the second zero reference phase, the second zero reference phase is taken as the zero phase.

[0111] In some embodiments, when the zero phase is the first zero reference phase, the processing module 602 is configured to calculate an absolute value of a difference between the first phase and the zero phase to obtain a first absolute value; calculate an absolute value of a difference between the first phase and the second phase to obtain a second absolute value; and calculate a ratio of the first absolute value to the second absolute value as a duty cycle of the switch signal.

[0112] In some embodiments, when the zero phase is the second zero reference phase, the processing module 602 is configured to calculate an absolute value of a difference between the second phase and the zero phase to obtain a third absolute value; calculate an absolute value of a difference between the first phase and the second phase to obtain a fourth absolute value; and calculate a ratio of the third absolute value to the fourth absolute value as a duty cycle of the switch signal.

[0113] In some embodiments, the acquisition module 601 is configured to acquire a current motor rotor position angle and an initial phase of the voltage instruction; and calculate a sum of the current motor rotor position angle and the initial phase as the first phase of the voltage instruction at a current sampling point.

[0114] In some embodiments, the processing module 602 is configured to acquire a motor speed and a sampling period of a motor controller; calculate a product of the motor speed and the sampling period to determine a phase difference between the first phase and the second phase; and determine the second phase based on the phase difference and the first phase.

[0115] Based on the hardware implementation of each unit in the above motor control device, an electronic device is further provided in the embodiments of the present application. Figure 7 As shown in FIG. 7, the device 70 includes a processor 701 and a memory 702 configured to store a computer program capable of running on the processor. Figure 6

[0116] The processor 701 is configured to execute the steps of the method in the above embodiments when the computer program is running.

[0117] Of course, in actual applications, the electronic device can further include other components, such as a bus, an input device, an output device, a power supply, etc. Figure 7 ​As shown, the various components in the electronic device are coupled together by a bus system 703. It is to be understood that the bus system 703 is used for facilitating communication between the various components and is not necessarily bi-directional. The bus system 703 includes a data bus to facilitate the transfer of computer program instructions and data between the components. The bus system 703 can also include a control bus to facilitate the transfer of control information between the components. The bus system 703 can also include a state line bus to facilitate the transfer of status information between the components. However, for the sake of clarity, only a single bus is shown in FIG. 7 and is referred to as the bus system 703. Figure 7

[0118] In practical applications, the processor can be at least one of an application specific integrated circuit (ASIC), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, and a microprocessor. It is to be understood that the electronic device used to implement the functions of the processor can also be other electronic devices, and the embodiments of the present application are not limited in this regard.

[0119] The memory can be a volatile memory (e.g., a random access memory (RAM)), a non-volatile memory (e.g., a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD)), or a combination of the above types of memories, and provides instructions and data to the processor.

[0120] In exemplary embodiments, the embodiments of the present application also provide a computer readable storage medium, such as a memory including a computer program, which can be executed by a processor of an electronic device to complete the steps of the foregoing method.

[0121] ​It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this application, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "and / or," "includes" and / or "comprising," or "includes" and / or "comprising," when used in this specification, specify the presence of features, elements, components, or integers, but do not preclude the presence or addition of one or more other features, elements, components, or integers.

[0122] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various information, the information should not be limited to these terms. These terms are only used to differentiate one piece of information from another piece of information. For example, a first piece of information can also be referred to as a second piece of information, and similarly, a second piece of information can also be referred to as a first piece of information without departing from the scope of the present application. The technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict. In the several embodiments provided in the present application, it should be understood that the disclosed methods, devices and equipment can be implemented by other means. The embodiments described above are only illustrative. For example, the division of units is only a logical function division, and actual implementation can have another division manner, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed components can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0123] The units described above as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0124] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be realized in the form of hardware or in the form of hardware plus software functional unit.

[0125] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method of controlling an electric machine, characterized by, The method comprises: acquiring a first phase of a voltage instruction at a current sampling point; determining a second phase of the voltage instruction at a next sampling point based on the first phase; determining whether a first voltage polarity at the current sampling point and a second voltage polarity at the next sampling point are the same based on the first phase and the second phase; determining that the first voltage polarity and the second voltage polarity are different, determining a zero point phase based on the first phase and the second phase; determining a duty cycle of an inverter switch signal based on the first phase, the second phase and the zero point phase; controlling opening and closing of the inverter switch based on the duty cycle of the switch signal.

2. The method of claim 1, wherein, The determination of whether the first voltage polarity at the current sampling point and the second voltage polarity at the next sampling point are the same based on the first phase and the second phase comprises: if the first phase is less than a zero point reference phase and the second phase is greater than the zero point reference phase, it is determined that the first voltage polarity and the second voltage polarity are different; otherwise, it is determined that the first voltage polarity and the second voltage polarity are the same.

3. The method of claim 1, wherein, The method further comprises: determining that the first voltage polarity and the second voltage polarity are the same, and controlling the inverter switch to remain in a current state.

4. The method of claim 1, wherein, The determination of the zero point phase based on the first phase and the second phase comprises: if the first phase is less than a first zero point reference phase and the second phase is greater than the first zero point reference phase, the first zero point reference phase is taken as the zero point phase; the first zero point reference phase is π; or, if the first phase is less than a second zero point reference phase and the second phase is greater than the second zero point reference phase, the second zero point reference phase is taken as the zero point phase; the second zero point reference phase is 0.

5. The method of claim 4, wherein, The zero point phase is the first zero point reference phase, and the first voltage polarity is positive, The determination of the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero point phase comprises: calculating an absolute value of a difference between the first phase and the zero point phase to obtain a first absolute value; calculating an absolute value of a difference between the first phase and the second phase to obtain a second absolute value; calculating a ratio of the first absolute value and the second absolute value as the duty cycle of the switch signal.

6. The method of claim 4, wherein, The zero point phase is the second zero point reference phase, and the second voltage polarity is positive, The determination of the duty cycle of the inverter switch signal based on the first phase, the second phase and the zero point phase comprises: calculating an absolute value of a difference between the second phase and the zero point phase to obtain a third absolute value; calculating an absolute value of a difference between the first phase and the second phase to obtain a fourth absolute value; calculating a ratio of the third absolute value and the fourth absolute value as the duty cycle of the switch signal.

7. The method of claim 1, wherein, The acquisition of the first phase of the voltage instruction at the current sampling point comprises: acquiring a current motor rotor position angle and an initial phase of the voltage instruction; calculating a sum of the current motor rotor position angle and the initial phase as the first phase of the voltage command at a current sampling point.

8. The method of claim 1, wherein, determining the second phase of the voltage command at a next sampling point based on the first phase, comprises: obtaining a motor speed and a sampling period of a motor controller; calculating a product of the motor speed and the sampling period to determine a phase difference between the first phase and the second phase; determining the second phase based on the phase difference and the first phase.

9. An electric motor control device characterized by comprising: The apparatus comprises: an obtaining module configured to obtain a first phase of a voltage command at a current sampling point; a processing module configured to determine a second phase of the voltage command at a next sampling point based on the first phase; the processing module is further configured to determine whether a first voltage polarity at the current sampling point and a second voltage polarity at the next sampling point are the same based on the first phase and the second phase; the processing module is further configured to determine a zero phase based on the first phase and the second phase when the first voltage polarity and the second voltage polarity are different; the processing module is further configured to determine a duty cycle of an inverter switching signal based on the first phase, the second phase and the zero phase; the processing module is further configured to control opening and closing of the inverter switching based on the duty cycle of the switching signal.

10. An electronic device, comprising: The device comprises a processor and a memory configured to store a computer program capable of running on the processor, wherein the processor is configured to execute the steps of the method of any one of claims 1-8 when running the computer program.

11. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1-8.

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