Motor control method, system, motor controller, storage medium and home appliance

Abstract

The application discloses a motor control method, system, motor controller, storage medium and household appliance. The method comprises the following steps: acquiring a zero-crossing waveform of an alternating power supply; determining a power supply period according to the zero-crossing waveform, and synchronously starting a clock counter of a motor control chip when counting phase zero-crossing points of the alternating power supply according to the zero-crossing waveform; acquiring a count value of the clock counter when the number of the phase zero-crossing points reaches a target value, and determining a motor angular frequency calculation clock according to the target value, the count value of the clock counter and the power supply period; determining a rotor position angular frequency according to the motor angular frequency calculation clock, and controlling the motor according to the rotor position angular frequency. Thus, the method can improve the accuracy of the motor angular frequency calculation clock, improve the accuracy of the rotor position angular frequency, and thus improve the control accuracy of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of household appliance control, and in particular to a motor control method, a motor controller, a computer readable storage medium, a motor control system and a household appliance. BACKGROUND

[0002] With the increasing demand for low-carbon and environmental protection of household appliances, direct-current variable frequency motors are increasingly used in household appliances, and the functional and precision requirements for direct-current variable frequency motor controllers are also increasingly high, such as constant power output control. However, the RC oscillator inside the MCU (Micro-controller Unit) has low precision, which cannot meet the high-precision power control requirements for direct-current variable frequency motors.

[0003] In related technologies, in order to meet the requirements for high-precision speed and power control of direct-current variable frequency motors, a high-precision oscillation circuit is usually designed for the MCU. However, the cost of the high-precision oscillation circuit is about 0.5-1 yuan, and in order to ensure the reliable operation of the high-precision oscillation circuit, three-proofing or even waterproof protection is required in the process. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, the first object of the present application is to provide a motor control method that can improve the precision of the rotor position angle frequency and thus improve the control precision of the motor.

[0005] The second object of the present application is to provide a motor controller.

[0006] The third object of the present application is to provide a computer readable storage medium.

[0007] The fourth object of the present application is to provide a motor control system.

[0008] The fifth object of the present application is to provide a household appliance.

[0009] To achieve the above objects, the first aspect of the present application provides a motor control method, comprising: acquiring a zero-crossing waveform of an alternating current power supply; determining a power supply period according to the zero-crossing waveform, and synchronously starting a clock counter of a motor control chip when counting phase zero-crossing points of the alternating current power supply according to the zero-crossing waveform; acquiring a count value of the clock counter when the number of phase zero-crossing points reaches a target value, and determining a motor angle frequency calculation clock according to the target value, the count value of the clock counter and the power supply period; determining a rotor position angle frequency according to the motor angle frequency calculation clock, and controlling a motor according to the rotor position angle frequency.

[0010] According to one embodiment of the present application, the power supply period is determined according to the zero-crossing waveform, comprising: performing noise filtering on the zero-crossing waveform, and obtaining phase zero-crossing points at rising edges of the filtered zero-crossing waveform; and determining the power supply period according to time intervals between two adjacent phase zero-crossing points.

[0011] According to one embodiment of the present application, the motor angular frequency calculation clock is calculated according to the following formula:

[0012] H=Y*Z / X, wherein H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is a count value of the clock counter.

[0013] According to one embodiment of the present application, the zero-crossing waveform of an alternating power supply is obtained, comprising: performing zero-crossing point isolation sampling on a voltage waveform of the alternating power supply after rectification to obtain the zero-crossing waveform.

[0014] The motor control method according to the embodiment of the present application can improve the accuracy of the rotor position angular frequency, thereby improving the control accuracy of the motor.

[0015] To achieve the above object, the second aspect of the present application provides a motor controller, comprising a memory, a processor, and a motor control program stored in the memory and executable on the processor, wherein the processor executes the motor control program to implement the motor control method.

[0016] To achieve the above object, the third aspect of the present application provides a computer readable storage medium having a motor control program stored thereon, wherein the motor control program is executable on a processor to implement the motor control method.

[0017] To achieve the above object, the fourth aspect of the present application provides a motor control system, comprising: a rectification unit configured to rectify an alternating power supply; a zero-crossing sampling unit configured to perform zero-crossing point sampling on a voltage waveform output by the rectification unit to obtain a zero-crossing waveform; and a motor control chip configured to determine a power supply period according to the zero-crossing waveform, and to start a clock counter of the motor control chip synchronously when counting phase zero-crossing points of the alternating power supply according to the zero-crossing waveform, and to obtain a count value of the clock counter when a number of the phase zero-crossing points reaches a target value, and to determine a motor angular frequency calculation clock according to the target value, the count value of the clock counter, and the power supply period, and to determine a rotor position angular frequency according to the motor angular frequency calculation clock, so as to control a motor according to the rotor position angular frequency.

[0018] Further, the motor control system further comprises a noise filtering unit configured to perform noise filtering on the zero-crossing waveform; and the motor control chip is further configured to obtain a phase zero-crossing point at a rising edge of the filtered zero-crossing waveform, and determine the power supply period according to a time interval between two adjacent phase zero-crossing points.

[0019] According to an embodiment of the present application, the motor control chip calculates the motor angular frequency calculation clock according to the following formula:

[0020] H=Y*Z / X, where H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is a count value of the clock counter.

[0021] According to an embodiment of the present application, the zero-crossing sampling unit comprises: a first resistor and a second resistor connected between positive and negative output terminals of the rectifying unit, and connected in series with a first node; a first diode, an anode of which is connected to the positive output terminal of the rectifying unit, and a cathode of which is connected to a positive terminal of a later-stage filtering capacitor; and an optocoupler, a photodiode anode of which is connected to the first node, a photodiode cathode of which is grounded, and a phototriode collector of which is connected to an upper pull power supply through a third resistor, and a phototriode emitter of which is grounded, where the phototriode collector of the optocoupler serves as an output terminal of the zero-crossing sampling unit.

[0022] The motor control system according to the embodiment of the present application can improve the accuracy of the rotor position angular frequency, thereby improving the control accuracy of the motor.

[0023] To achieve the above object, the fifth aspect embodiment of the present application provides a household appliance comprising the motor control system.

[0024] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flowchart of a motor control method according to an embodiment of the present application;

[0026] Figure 2 is a schematic diagram of a zero-crossing waveform and an AC power supply voltage waveform according to an embodiment of the present application;

[0027] Figure 3 is a schematic diagram of controlling a motor speed according to an embodiment of the present application;

[0028] Figure 4is a structural schematic diagram of a motor control system according to an embodiment of the present application;

[0029] Figure 5 is a circuit topology diagram of a motor control system according to an embodiment of the present application;

[0030] Figure 6 is a structural schematic diagram of a motor control system according to another embodiment of the present application;

[0031] Figure 7 is a structural schematic diagram of a household appliance according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, in which the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0033] The accompanying drawings are referred to in order to describe the embodiments of the present application in detail. Figures 1-7 A motor control method, system, motor controller, storage medium and household appliance according to an embodiment of the present application are described below.

[0034] Figure 1 is a flowchart of a motor control method according to an embodiment of the present application. As shown in Figure 1 , the motor control method comprises the following steps:

[0035] S101, obtaining a zero-crossing waveform of an alternating power supply.

[0036] Specifically, the zero-crossing waveform can be obtained by performing zero-crossing isolated sampling on the voltage waveform of the rectified alternating power supply.

[0037] S102, determining a power supply period according to the zero-crossing waveform, and synchronously starting a clock counter of a motor control chip when counting the phase zero-crossing of the alternating power supply according to the zero-crossing waveform.

[0038] As an example, determining the power supply period according to the zero-crossing waveform can comprise: performing noise filtering processing on the zero-crossing waveform, and obtaining a phase zero-crossing on the rising edge of the filtered zero-crossing waveform; determining the power supply period according to the time interval between the adjacent two phase zero-crossings.

[0039] Specifically, the power supply period T of the zero-crossing waveform obtained by performing zero-crossing isolated sampling on the voltage waveform of the rectified alternating power supply is consistent with half of the period of the voltage waveform of the alternating power supply (see Figure 2). Thus, the embodiment of the application filters the zero-crossing waveform by the noise filter, acquires the phase zero-crossing point at the rising edge of the filtered zero-crossing waveform, and determines the power supply period according to the time interval between the adjacent two phase zero-crossing points.

[0040] Further, when counting the phase zero-crossing points of the AC power supply according to the zero-crossing waveform, the clock counter of the motor control chip is started.

[0041] Specifically, the counting of the phase zero-crossing points of the AC power supply can be started at the voltage rising edge interrupt response, and the clock counter of the motor control chip is started to count the low-precision motor angular frequency calculation clock.

[0042] S103, when the number of phase zero-crossing points reaches a target value, the count value of the clock counter is acquired, and the motor angular frequency calculation clock is determined according to the target value, the count value of the clock counter and the power supply period.

[0043] Specifically, the target value Y of the phase zero-crossing points can be set according to the precision requirement, when the number of phase zero-crossing points of the AC power supply is equal to the target value Y, the clock counter of the motor control chip stops counting, and the count value of the clock counter at this time is acquired.

[0044] It should be noted that the phase zero-crossing points have a phase error of about 5 degrees through the grid high-frequency harmonic, the frequency bandwidth limitation of the sampling circuit and the processing of the software algorithm. Thus, by setting the target value Y of the phase zero-crossing points, the problem of phase zero-crossing point deviation is solved.

[0045] Further, the motor angular frequency calculation clock is calculated according to the formula H=Y*Z / X, wherein H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is the count value of the clock counter. Thus, the accurate time of the motor angular frequency calculation clock can be obtained.

[0046] S104, the rotor position angular frequency is determined according to the motor angular frequency calculation clock, and the motor is controlled according to the rotor position angular frequency.

[0047] Specifically, the rotor position angular frequency ω is determined according to the motor angular frequency calculation clock, and the motor is controlled according to that the motor output power is equal to the product of the rotor position angular frequency ω and the output torque T, and the motor speed determined according to the rotor position angular frequency ω (see Figure 3 ). Thus, by improving the accuracy of the rotor position angular frequency, the control accuracy of the motor output power and the motor speed is improved.

[0048] In summary, the motor control method determines the power supply period through the zero-crossing waveform, and when counting the phase zero-crossing points of the alternating power supply according to the zero-crossing waveform, the clock counter of the motor control chip is started synchronously, and when the number of the phase zero-crossing points reaches a target value, the count value of the clock counter is obtained, and the motor angular frequency calculation clock is determined according to the target value, the count value of the clock counter and the power supply period, and then the rotor position angular frequency is determined according to the motor angular frequency calculation clock, and the motor is controlled according to the rotor position angular frequency, which can improve the accuracy of the motor angular frequency calculation clock, improve the accuracy of the rotor position angular frequency, and thus improve the control accuracy of the motor output power and the motor speed, and by omitting the high-precision oscillation circuit, the cost is saved and the reliability is higher, and the method has high engineering application value.

[0049] Based on the motor control method of the above embodiment, the application further provides a motor controller, which comprises a memory, a processor and a motor control program stored in the memory and executable on the processor, and when the processor executes the motor control program, the above motor control method is realized.

[0050] The motor controller of the embodiment of the application, when the computer program corresponding to the above motor control method stored thereon is executed, determines the power supply period through the zero-crossing waveform, and when counting the phase zero-crossing points of the alternating power supply according to the zero-crossing waveform, the clock counter of the motor control chip is started synchronously, and when the number of the phase zero-crossing points reaches a target value, the count value of the clock counter is obtained, and the motor angular frequency calculation clock is determined according to the target value, the count value of the clock counter and the power supply period, and then the rotor position angular frequency is determined according to the motor angular frequency calculation clock, and the motor is controlled according to the rotor position angular frequency, which can improve the accuracy of the motor angular frequency calculation clock, improve the accuracy of the rotor position angular frequency, and thus improve the control accuracy of the motor output power and the motor speed, and by omitting the high-precision oscillation circuit, the cost is saved and the reliability is higher, and the method has high engineering application value.

[0051] Based on the motor control method of the above embodiment, the application further provides a computer readable storage medium, which stores a motor control program, and when the motor control program is executed by a processor, the above motor control method is realized.

[0052] When the computer-readable storage medium of this invention, storing a computer program corresponding to the above-described motor control method, is executed, the power cycle is determined by the zero-crossing waveform. While counting the phase zero-crossing points of the AC power supply based on the zero-crossing waveform, the clock counter of the motor control chip is synchronously started. When the number of phase zero-crossing points reaches a target value, the count value of the clock counter is obtained. Based on the target value, the count value of the clock counter, and the power cycle, a motor angular frequency calculation clock is determined. Then, the rotor position angular frequency is determined based on the motor angular frequency calculation clock, and the motor is controlled based on the rotor position angular frequency. This improves the accuracy of the motor output power and the control accuracy of the motor speed by increasing the accuracy of the motor angular frequency calculation clock and the rotor position angular frequency. Furthermore, by eliminating the need to design a high-precision oscillation circuit, it not only saves costs but also increases reliability, making it highly valuable for engineering applications.

[0053] Figure 4 This is a schematic diagram of the structure of a motor control system according to an embodiment of the present invention. Figure 4 As shown, the motor control system 100 includes: a rectifier unit 10, a zero-crossing sampling unit 20, and a motor control chip 30. The rectifier unit 10 is used to rectify the AC power supply; the zero-crossing sampling unit 20 is used to sample the zero-crossing points of the voltage waveform output by the rectifier unit 10 to obtain the zero-crossing waveform; the motor control chip 30 is used to determine the power supply cycle based on the zero-crossing waveform, and synchronously start its own clock counter while counting the phase zero-crossing points of the AC power supply based on the zero-crossing waveform. When the number of phase zero-crossing points reaches a target value, it acquires the count value of the clock counter, and determines the motor angular frequency calculation clock based on the target value, the clock counter count value, and the power supply cycle. It also determines the rotor position angular frequency based on the motor angular frequency calculation clock, so as to control the motor according to the rotor position angular frequency.

[0054] In this example, the rectifier unit 10 is supplied with AC power (see...). Figure 5 The live wire (L) and neutral wire (N) are rectified. Further, see... Figure 5The zero-crossing sampling unit 20 comprises a first resistor R1 and a second resistor R2 connected between the positive and negative output terminals (i.e. 1, 4) of the rectifying unit 10 (i.e. the positive output terminal 4 of the rectifying unit 10 is connected with the first resistor R1, and the negative output terminal 1 of the rectifying unit 10 is connected with the second resistor R2), a first diode D1 and an optical coupler O1. The first resistor R1 and the second resistor R2 are connected in series and have a first node a; the anode of the first diode D1 is connected with the positive output terminal 4 of the rectifying unit 10, and the cathode of the first diode D1 is connected with the positive terminal of a filter capacitor C1 in the rear stage; the anode of a photodiode D2 of the optical coupler O1 is connected with the first node a, the cathode of the photodiode D2 is grounded, the collector of a phototriode P1 of the optical coupler O1 is connected with a third resistor R3 and an upper power supply VCC, the emitter of the phototriode P1 is grounded, and the collector of the phototriode P1 of the optical coupler O1 is used as an output terminal of the zero-crossing sampling unit 20. Thus, the zero-crossing sampling unit 20 samples the zero-crossing point of the voltage waveform output by the rectifying unit 10, and obtains a zero-crossing waveform.

[0055] Referring to Figures 5-6 The motor control system 100 further comprises a noise filtering unit 40 for filtering the zero-crossing waveform. Specifically, the noise filtering unit 40 comprises a filter capacitor C1, and the filter capacitor C1 is used to filter the high-frequency harmonic components in the power grid.

[0056] In this example, the negative terminal of the filter capacitor C1 is connected with the negative output terminal 1 of the rectifying unit 10 and an IPM (Intelligent Power Module) 50.

[0057] Further, the motor control chip 30 is connected with the output terminal of the zero-crossing sampling unit 20, and is used to determine the power supply period according to the zero-crossing waveform, and when counting the phase zero-crossing points of the alternating power supply, synchronously starts a clock counter of the motor control chip 30, and when the number of the phase zero-crossing points reaches a target value, obtains the counting value of the clock counter, and determines a motor angle frequency calculation clock according to the target value, the counting value of the clock counter and the power supply period, and determines a rotor position angle frequency according to the motor angle frequency calculation clock, so as to control the motor M according to the rotor position angle frequency.

[0058] Further, the motor control chip 30 is further used to obtain the phase zero-crossing point at the rising edge of the zero-crossing waveform after the filtering processing, and determine the power supply period according to the time interval between two adjacent phase zero-crossing points.

[0059] Specifically, the power supply period T of the zero-crossing waveform obtained by sampling the zero-crossing point of the voltage waveform after the rectification of the alternating power supply is consistent with half of the period of the voltage waveform of the alternating power supply (seeFigure 2 ). Thus, the embodiment of the application obtains the phase zero-crossing point from the rising edge of the zero-crossing waveform after filtering, and determines the power supply period according to the time interval between the adjacent two phase zero-crossing points.

[0060] Further, the motor control chip 30 is further configured to start the clock counter of the motor control chip synchronously when counting the phase zero-crossing points of the AC power supply according to the zero-crossing waveform.

[0061] Specifically, the counting of the phase zero-crossing points of the AC power supply can be started at the voltage rising edge interrupt response, and the clock counter of the motor control chip is started to count the motor angular frequency calculation clock with low precision at the same time.

[0062] Further, the motor control chip 30 is further configured to obtain the counting value of the clock counter when the number of phase zero-crossing points reaches a target value, and determine the motor angular frequency calculation clock according to the target value, the counting value of the clock counter and the power supply period.

[0063] Specifically, the target value Y of the number of phase zero-crossing points can be set according to the precision requirement, and when the number of phase zero-crossing points of the AC power supply is equal to the target value Y, the clock counter of the motor control chip stops counting, and the counting value of the clock counter at this time is obtained. Thus, by setting the target value Y of the number of phase zero-crossing points, the problem of phase zero-crossing point deviation is solved.

[0064] It should be noted that the phase zero-crossing point will have a phase error of about 5 degrees through the grid high-frequency harmonic, the frequency bandwidth limitation of the sampling circuit, and the processing of the software algorithm. Thus, by setting the target value Y of the phase zero-crossing point, the problem of phase zero-crossing point deviation is solved.

[0065] Further, the motor control chip 30 is further configured to calculate the motor angular frequency calculation clock according to the following formula:

[0066] H=Y*Z / X, wherein H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is the counting value of the clock counter. Thus, the accurate time of the motor angular frequency calculation clock can be obtained.

[0067] Further, the motor control chip 30 is further configured to determine the rotor position angular frequency according to the motor angular frequency calculation clock, and control the motor M according to the rotor position angular frequency.

[0068] Specifically, the rotor position angular frequency ω is determined according to the motor angular frequency calculation clock, and the motor output power is equal to the product of the rotor position angular frequency ω and the output torque T, and the motor speed determined according to the rotor position angular frequency ω (see Figure 3), controls the motor M. Thus, by improving the accuracy of the rotor position angle frequency, the control accuracy of the motor output power is improved.

[0069] It should be noted that, referring to Figure 5 , the IPM 50 is connected with the motor control chip 30 and the motor M, and is used for protecting the circuit in the whole system. The IPM 50 is an advanced power switching device, which is composed of a high-speed and low-power IGBT (Insulated Gate Bipolar Transistor) chip and an optimal gate-level drive and protection circuit. The built-in drive and protection circuit makes the system hardware circuit simple and reliable, shortens the system development time, and improves the self-protection ability under fault.

[0070] In summary, the motor control system determines the power cycle through the zero-crossing waveform, and when counting the phase zero-crossing points of the alternating power supply according to the zero-crossing waveform, the clock counter of the motor control chip is started synchronously. When the number of the phase zero-crossing points reaches a target value, the count value of the clock counter is obtained, and the motor angle frequency calculation clock is determined according to the target value, the count value of the clock counter and the power cycle. Then, the rotor position angle frequency is determined according to the motor angle frequency calculation clock, and the motor is controlled according to the rotor position angle frequency. The accuracy of the motor angle frequency calculation clock can be improved, the accuracy of the rotor position angle frequency is improved, and thus the control accuracy of the motor output power and the motor speed is improved. Moreover, by omitting the design of the high-precision oscillation circuit, the cost is saved and the reliability is higher, and the application value in engineering is higher.

[0071] Based on the motor control system 100 in the above embodiment, as shown in Figure 7 , the application further provides a household appliance 200 comprising the motor control system 100.

[0072] The household appliance 200 in the embodiment of the application determines the power cycle through the zero-crossing waveform, and when counting the phase zero-crossing points of the alternating power supply according to the zero-crossing waveform, the clock counter of the motor control chip is started synchronously. When the number of the phase zero-crossing points reaches a target value, the count value of the clock counter is obtained, and the motor angle frequency calculation clock is determined according to the target value, the count value of the clock counter and the power cycle. Then, the rotor position angle frequency is determined according to the motor angle frequency calculation clock, and the motor is controlled according to the rotor position angle frequency. The accuracy of the motor angle frequency calculation clock can be improved, the accuracy of the rotor position angle frequency is improved, and thus the control accuracy of the motor output power and the motor speed is improved. Moreover, by omitting the design of the high-precision oscillation circuit, the cost is saved and the reliability is higher, and the application value in engineering is higher.

[0073] In addition, other configurations and functions of the home appliance 200 according to the embodiments of the present application are known to those skilled in the art, and thus, a detailed description thereof will not be given herein in order to avoid redundancy.

[0074] It should be noted that the logic and / or steps represented in the flowcharts and / or described herein can be considered as a sequence of executable instructions for implementing logic functions in any computer readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination thereof. For purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can specifically include the following: an electronic connection having one or more wires (electronic apparatus), a portable computer diskette (magnetic apparatus), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disk read-only memory (CDROM). In addition, the computer readable medium can even be paper or other suitable medium upon which the program can be printed, because the program can be electronically obtained, for example, by optically scanning the paper or other medium, then

[0075] It should be understood that portions of the present application can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, a number of steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, and as in another embodiment, any of the following technologies, known in the art, or a combination thereof, can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0076] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0077] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0078] In addition, the terms "first", "second", etc. used in the embodiments of the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of technical features referred to in the embodiments. Therefore, the features defined with the terms "first", "second" and the like in the embodiments of the present application can be explicitly or implicitly indicated to include at least one of the features in the embodiments. In the description of the present application, the meaning of the word "plurality" is at least two or two or more, such as two, three, four, etc., unless otherwise specifically limited in the embodiments.

[0079] In the present application, unless otherwise specifically related or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" and the like appearing in the embodiments should be understood in a broad sense, for example, the connection can be a fixed connection, or a detachable connection, or integrated, which can be understood, or can be a mechanical connection, an electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements, or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific implementation situation.

[0080] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "over", "above" and "on top of" the second feature can mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. The first feature is "under", "below" and "underneath" the second feature can mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0081] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are exemplary only, and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made thereto by those skilled in the art without departing from the scope of the present application.

Claims

1. A method of controlling an electric machine, characterized by, The method comprises: acquiring a zero-crossing waveform of an AC power supply; determining a power supply period according to the zero-crossing waveform, and synchronously starting a clock counter of a motor control chip when counting phase zero-crossings of the AC power supply according to the zero-crossing waveform; when the number of phase zero-crossings reaches a target value, acquiring a count value of the clock counter, and determining a motor angular frequency calculation clock according to the target value, the count value of the clock counter and the power supply period; determining a rotor position angular frequency according to the motor angular frequency calculation clock, and controlling a motor according to the rotor position angular frequency.

2. The method of claim 1, wherein, The method comprises: performing noise filtering processing on the zero-crossing waveform, and acquiring a phase zero-crossing at a rising edge of the filtered zero-crossing waveform; determining the power supply period according to a time interval between two adjacent phase zero-crossings.

3. The method of claim 1, wherein, The motor angular frequency calculation clock is calculated according to the following formula: H=Y*Z / X, wherein H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is the count value of the clock counter.

4. The method according to any one of claims 1 to 3, characterized in that, The method comprises: performing zero-crossing isolation sampling on a voltage waveform rectified from the AC power supply to obtain the zero-crossing waveform.

5. An electric motor controller characterized by The motor control method according to any one of claims 1-4 is implemented by a motor control program stored in the memory and executable on the processor.

6. A computer-readable storage medium, characterized in that, The motor control method according to any one of claims 1-4 is implemented by a motor control program stored on the memory and executable on the processor.

7. An electric motor control system characterized by comprising: The method comprises: a rectification unit configured to rectify an AC power supply; a zero-crossing sampling unit configured to perform zero-crossing sampling on a voltage waveform output by the rectification unit to obtain a zero-crossing waveform; a motor control chip configured to determine a power supply period according to the zero-crossing waveform, synchronously start a clock counter of the motor control chip when counting phase zero-crossings of the AC power supply according to the zero-crossing waveform, acquire a count value of the clock counter when the number of phase zero-crossings reaches a target value, determine a motor angular frequency calculation clock according to the target value, the count value of the clock counter and the power supply period, determine a rotor position angular frequency according to the motor angular frequency calculation clock, and control a motor according to the rotor position angular frequency.

8. The motor control system of claim 7, wherein, The method further comprises a noise filtering unit configured to perform noise filtering processing on the zero-crossing waveform. The motor control chip is further configured to acquire a phase zero-crossing at a rising edge of the filtered zero-crossing waveform, and determine the power supply period according to a time interval between two adjacent phase zero-crossings.

9. The motor control system of claim 7, wherein, The motor control chip calculates the motor angular frequency calculation clock according to the following formula: H=Y*Z / X, wherein H is the motor angular frequency calculation clock, Y is the target value, Z is the power supply period, and X is the count value of the clock counter.

10. The motor control system of any one of claims 7-9, wherein, The zero-crossing sampling unit comprises: a first resistor and a second resistor connected between the positive and negative output terminals of the rectifying unit, the first resistor and the second resistor being connected in series and having a first node therebetween; a first diode, an anode of the first diode being connected to the positive output terminal of the rectifying unit, a cathode of the first diode being connected to a positive terminal of a post-stage filter capacitor; an optocoupler, a photodiode anode of the optocoupler being connected to the first node, a photodiode cathode of the optocoupler being grounded, a photo triode collector of the optocoupler being connected to an upper pull power supply through a third resistor, a photo triode emitter of the optocoupler being grounded, wherein the photo triode collector of the optocoupler serves as an output terminal of the zero-crossing sampling unit.

11. An electric home appliance characterized by comprising: An electric machine control system comprising any one of the claims 7-10.

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