Motor control circuit, control method and device, terminal equipment and storage medium

Abstract

The invention relates to a motor control circuit, a motor control method, a motor control device, terminal equipment and a storage medium. The inverter circuit is connected with the direct-current power supply and is used for converting direct current provided by the direct-current power supply into three-phase alternating current; the transmitting end of the three-phase wireless transmission circuit is connected with the inverter circuit and is used for transmitting the electric energy of the three-phase alternating current to the receiving end; the receiving end is used for receiving the electric energy sent by the transmitting end and generating three-phase alternating current; the rectifying circuit is connected with the receiving end and is used for converting the three-phase alternating current generated by the receiving end into three-phase direct current; the three-phase direct current is used for driving the three-phase induction motor to rotate; the three-phase direct current is equal in amplitude and frequency, the initial phase difference is 120 degrees, the direction of the current is unchanged, and the magnitude of the current changes along with time; the sampling circuit is used for collecting current signals flowing through the three stators; the controller is used for adjusting the working state of the inverter circuit according to the current signal and controlling the rotating speed of the induction motor.

Description

Technical Field

[0001] The present disclosure relates to the field of control technology, and in particular to a motor control circuit, control method, device, terminal equipment, and storage medium. Background Art

[0002] With the development of power electronics technology, its application in the control field is becoming more and more extensive. In the control field, motors are used as driving sources to provide driving force in many application scenarios. As the controlled object, the motor's rotation can be controlled by control circuits. Summary of the Invention

[0003] The present disclosure provides a motor control circuit, a control method, an apparatus, a terminal device, and a storage medium.

[0004] In a first aspect of an embodiment of the present disclosure, a motor control circuit is provided, comprising: a DC power supply; an inverter circuit connected to the DC power supply, for converting the DC power provided by the DC power supply into three-phase AC power; a three-phase wireless transmission circuit, having a wirelessly connected transmitting end and a receiving end; wherein the transmitting end is connected to the inverter circuit, for transmitting the electric energy of the three-phase AC power to the receiving end; the receiving end is for receiving the electric energy sent by the transmitting end and generating three-phase AC power; a rectifier circuit connected to the receiving end, for converting the three-phase AC power generated by the receiving end into Three-phase direct current; wherein the three-phase direct current is used to drive a three-phase induction motor to rotate; the three-phase direct current has equal amplitude, the same frequency, an initial phase difference of 120 degrees, and a constant direction of current, while the magnitude of the current changes over time; a sampling circuit is electrically connected to the three stators of the induction motor and is used to collect current signals flowing through the three stators; a controller is electrically connected to the sampling circuit and is used to adjust the operating state of the inverter circuit according to the current signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, and the frequency is used to control the speed of the induction motor.

[0005] In one embodiment, the controller includes: a first subtractor, used to subtract the stator current of each stator from a preset current to obtain a first difference corresponding to each stator current; wherein the current of each stator corresponds to its own preset current; a proportional-integral controller, connected to the receiving end of the subtractor, used to perform proportional-integral processing on each first difference to obtain a first modulation wave instruction signal of the inverter circuit corresponding to each stator current; a sinusoidal pulse frequency modulator, connected to the receiving end of the proportional-integral controller, and the receiving end of the sinusoidal pulse frequency modulator is connected to the transmitting end of the sinusoidal pulse frequency modulator, used to generate the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time according to each first modulation wave instruction signal and the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator last time; a pulse wave generator, connected to the receiving end of the sinusoidal pulse frequency modulator, used to generate a control signal of the inverter circuit according to each second modulation wave instruction signal.

[0006] In one embodiment, the sinusoidal pulse frequency modulator includes: a second subtractor, connected to the receiving end of the proportional-integral controller and the receiving end of the sinusoidal pulse frequency modulator, for performing a difference between each first modulation wave instruction signal and the corresponding second modulation wave instruction signal to obtain a second difference value corresponding to each first modulation wave instruction signal; an integral controller, connected to the receiving end of the second subtractor, for performing an integration process on each second difference value to obtain an integral signal corresponding to each second difference value; a quantizer, connected to the receiving end of the integral controller, for performing a quantization process on each integral signal to obtain a quantized signal corresponding to each integral signal; and a variable-period zero-order holder, connected to the receiving end of the quantizer, for obtaining each second modulation wave instruction signal according to each quantization signal and the number of quantization cycles of the quantizer.

[0007] In one embodiment, the three-phase wireless transmission circuit includes: three groups of parallel transceiver coils; wherein the transceiver coils include: a transmitting coil and a receiving coil, the transmitting coil serves as the transmitting end, and the receiving coil serves as the receiving end.

[0008] In one embodiment, the circuit further includes: a compensation circuit located between the transmitting end and the inverter circuit; and / or located between the receiving end and the rectifier circuit, for reducing the reactive power of the inverter circuit.

[0009] In one embodiment, the inverter circuit is a three-phase inverter circuit.

[0010] In one embodiment, the circuit further includes: a first wireless communication circuit, electrically connected to the sampling circuit, for sending the current signal; a second wireless communication circuit, wirelessly and electrically connected to the first wireless communication circuit and the controller, for receiving the current signal and sending the current signal to the controller.

[0011] In one embodiment, the circuit further includes: a driving circuit connected to a receiving end of the controller, for power amplifying the control signal; wherein the power-amplified control signal is used to control the working state of the inverter circuit.

[0012] A second aspect of the embodiments of the present disclosure provides a motor control method, which is applied to the motor control circuit in any of the above embodiments, and the method includes: collecting stator currents in three stators in a three-phase induction motor; determining a first difference corresponding to each stator current based on the stator current and a preset current; wherein each stator current corresponds to its own preset current; determining a first modulation wave instruction signal corresponding to each stator current based on each first difference; generating a second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time based on each first modulation wave instruction signal and a second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator last time; generating a control signal for the inverter circuit based on each second modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time; controlling the working state of the inverter circuit by means of the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, wherein the frequency is used to control the speed of the induction motor.

[0013] In one embodiment, determining the first modulation wave command signal corresponding to each stator current according to each first difference includes: performing a proportional integral operation on each first difference to obtain the first modulation wave command signal corresponding to each stator current.

[0014] In one embodiment, the obtaining of the corresponding second modulation wave instruction signal according to each first modulation wave instruction signal includes: performing a difference operation on each first modulation wave instruction signal and the corresponding second modulation wave instruction signal to obtain a second difference value corresponding to each first modulation wave instruction signal; performing an integration operation on each second difference value to obtain an integral signal corresponding to each second difference value; performing a quantization operation on each integral signal to obtain a quantized signal corresponding to each integral signal; and obtaining each second modulation wave instruction signal according to the number of quantization cycles and each quantized signal.

[0015] According to a third aspect of the embodiments of the present disclosure, a motor control device is provided, comprising: an acquisition module for acquiring stator currents in three stators of a three-phase induction motor; a first determination module for determining a first difference corresponding to each stator current based on the stator current and a preset current corresponding to each stator current; a second determination module for determining a first modulation wave instruction signal corresponding to each stator current based on each first difference; a third determination module for generating a second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time based on each first modulation wave instruction signal and a second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator last time; a control signal generation module for generating a control signal for an inverter circuit based on each second modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time; and a control module for controlling the working state of the inverter circuit through the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, wherein the frequency is used to control the speed of the induction motor.

[0016] According to a fourth aspect of the present disclosure, a terminal device is provided, including:

[0017] A processor and a memory for storing executable instructions that can be run on the processor, wherein: when the processor is used to run the executable instructions, the executable instructions execute the method described in any one of the above embodiments.

[0018] According to a fifth aspect of the embodiments of the present disclosure, a non-temporary computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the method described in any of the above embodiments.

[0019] According to a sixth aspect of the embodiments of the present disclosure, a terminal device is provided, comprising: the motor control circuit described in any one of the above embodiments.

[0020] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0021] The controller in the solution provided in the embodiment of the present disclosure can control the working state of the inverter circuit, adjust the frequency of the AC power output by the inverter circuit by adjusting the frequency and switch state of the switch in the inverter circuit, and then transmit the AC power to the rectifier circuit through a three-phase wireless transmission circuit. The three-phase DC power obtained after rectification by the rectifier circuit drives the induction motor to rotate. The speed and rotation direction of the induction motor can be adjusted by controlling the inverter circuit by the controller.

[0022] The control circuit structure in this solution is simple, and the structure between the wireless transmission transceiver circuit and the induction motor is relatively small, which reduces maintenance costs, improves control efficiency, and facilitates the high integration, lightweight and miniaturization of the motor control circuit.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0025] Figure 1 is a schematic diagram of a motor control circuit according to an exemplary embodiment;

[0026] Figure 2 is a schematic diagram of a controller according to an exemplary embodiment;

[0027] Figure 3 is a schematic diagram showing a method of generating a control signal according to an exemplary embodiment;

[0028] Figure 4 is a schematic diagram showing a simulation of a motor speed according to an exemplary embodiment;

[0029] Figure 5 is a schematic diagram of simulation of various stator currents in a motor according to an exemplary embodiment;

[0030] Figure 6a is a schematic diagram of simulation of current and voltage of a transmitting coil in a three-phase wireless transmission circuit according to an exemplary embodiment;

[0031] Figure 6b is a schematic diagram of current simulation of a receiving coil in a three-phase wireless transmission circuit 3 according to an exemplary embodiment;

[0032] Figure 7 is a schematic diagram showing a motor control method according to an exemplary embodiment;

[0033] Figure 8 is a schematic diagram showing a method of obtaining a second modulation wave instruction signal according to an exemplary embodiment;

[0034] Figure 9 is a schematic diagram of a motor control device according to an exemplary embodiment;

[0035] Figure 10 The figure is a block diagram of a terminal device according to an exemplary embodiment. DETAILED DESCRIPTION

[0036] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present disclosure. Rather, they are merely examples of devices consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0037] refer to Figure 1 , is a schematic diagram of a motor control circuit, comprising:

[0038] DC power supply 1.

[0039] The inverter circuit 2 is connected to the DC power supply and is used to convert the DC power provided by the DC power supply into three-phase AC power.

[0040] The three-phase wireless transmission circuit 3 has a wirelessly connected transmitting end and a receiving end; wherein the transmitting end is connected to the inverter circuit and is used to transmit the electric energy of the three-phase alternating current to the receiving end; the receiving end is used to receive the electric energy sent by the transmitting end and generate three-phase alternating current.

[0041] A rectifier circuit 4 is connected to the receiving end and is used to convert the three-phase alternating current generated by the receiving end into three-phase direct current; wherein the three-phase direct current is used to drive the three-phase induction motor to rotate; the three-phase direct current has equal amplitude, the same frequency, an initial phase difference of 120 degrees, and the direction of the current remains unchanged, and the current magnitude changes with time.

[0042] The sampling circuit 5 is electrically connected to the three stators of the induction motor and is used to collect current signals flowing through the three stators.

[0043] The controller 6 is electrically connected to the sampling circuit and is used to adjust the working state of the inverter circuit according to the current signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, which is used to control the speed of the induction motor.

[0044] The DC power source 1 may be a DC source such as a dry cell, a storage battery or a DC generator, or may be a converted DC source, for example, a DC source obtained by converting an AC source into an AC-DC (AC-DC) source.

[0045] The size of the DC power supply 1 is not limited and can be determined according to actual usage requirements.

[0046] The inverter circuit 2 can be a three-phase inverter circuit or three unidirectional inverter circuits, which can convert the DC power provided by the DC power supply 1 into three-phase AC power. The three-phase inverter circuit can include a three-phase full-bridge inverter circuit.

[0047] The circuit structure of the inverter circuit 2 can be determined according to actual usage requirements and can be a three-phase inverter.

[0048] For example, Figure 1 As shown, the inverter circuit 2 is a three-phase full-bridge inverter circuit, including six controlled switches Sw1, Sw2, Sw3, Sw4, Sw5 and Sw6. The controlled switches can be insulated gate bipolar transistors (IGBTs) or MOS tubes.

[0049] The bridge arm between the controlled switch Sw1 and the controlled switch Sw2 serves as the output point of one phase of AC power, the bridge arm between the controlled switch Sw3 and the controlled switch Sw4 serves as the output point of the other phase of AC power, and the bridge arm between the controlled switch Sw5 and the controlled switch Sw6 serves as the output point of another phase of AC power. In this way, the inverter circuit 2 can output three-phase AC power.

[0050] The three-phase wireless transmission circuit 3 includes a transmitter 301 and a receiver 302. The transmitter 301 and receiver 302 are wirelessly connected. The transmitter 301 is connected to the inverter circuit 2 and has the function of transmitting wireless signals, wirelessly transmitting the three-phase AC power received by the transmitter 301. The receiver 302 also has the function of receiving wireless signals and converting them into three-phase AC power.

[0051] The transmitting end 301 may include an input circuit, and the receiving end 302 may include an output circuit. For example, the input circuit may be a transmitting coil, and the output circuit may be a receiving coil. The number of turns of the transmitting coil and the receiving coil may be determined based on actual needs.

[0052] In one embodiment, the three-phase wireless transmission circuit 3 includes three sets of parallel transceiver coils, each set of transceiver coils includes: a transmitting coil and a receiving coil, the transmitting coil serves as a transmitting end 301, and the receiving coil serves as a receiving end 302. For ease of explanation, the transmitting coil can be used as the transmitting end in Figure 1 middle.

[0053] like Figure 1As shown, transmitting coil L1 and receiving coil L2 form a transceiver coil pair, transmitting coil L3 and receiving coil L4 form a transceiver coil pair, and transmitting coil L5 and receiving coil L6 form a transceiver coil pair. Each transceiver coil pair functions as a single-phase AC power transmission circuit. Receiving coil L2 can receive wireless signals sent by transmitting coil L1, receiving coil L4 can receive wireless signals sent by transmitting coil L3, and receiving coil L6 can receive wireless signals sent by transmitting coil L5.

[0054] Transmitting coils L1, L5, and L3 are connected to three different bridge arms in the three-phase inverter circuit. Transmitting coil L1 has one end connected to the bridge arm between controlled switches Sw1 and Sw2, and the other end connected to the negative terminal of DC power supply 1. Transmitting coil L3 has one end connected to the bridge arm between controlled switches Sw3 and Sw4, and the other end connected to the negative terminal of DC power supply 1. Transmitting coil L5 has one end connected to the bridge arm between controlled switches Sw5 and Sw6, and the other end connected to the negative terminal of DC power supply 1.

[0055] Since the transmitting coil and the receiving coil in the three-phase wireless transmission circuit 3 are wirelessly connected, wireless signals can be transmitted in the form of radio electromagnetic waves. Therefore, the transmitting coil and the receiving coil can be separated, thereby achieving wireless transmission over longer distances. The three parts of the DC power supply 1, the inverter circuit 2 and the transmitting end 301 can be separated from the three parts of the receiving end 302, the rectifier circuit 4 and the motor M. There is no need to use wired wires to connect the transmitting end 301 and the receiving end 302 of the three-phase wireless transmission circuit 3, which can meet the usage requirements of more application scenarios.

[0056] The three-phase wireless transmission circuit 3 includes three sets of transceiver coils, which realize the decoupling of each phase AC transmission line, eliminate the mutual coupling between the three-phase AC transmission lines, reduce mutual interference, and realize independent modulation and control of each phase AC.

[0057] In one embodiment, the three-phase wireless transmission circuit 3 may include three transformers, each having a primary coil and a secondary coil. The primary coil serves as the transmitting end, i.e., the transmitting coil; the secondary coil serves as the receiving end, i.e., the receiving coil. Each primary coil is connected to an inverter circuit, and each secondary coil is connected to a rectifier circuit 4.

[0058] Rectifier circuit 4 is connected to receiver 302 and is configured to convert the three-phase AC power generated by receiver 302 into three-phase DC power. The structure of rectifier circuit 4 is not limited; any circuit with a rectifying function can be considered a rectifier circuit, such as a diode. Alternatively, a bridge rectifier circuit can be used, including a full-bridge rectifier circuit and a plate-bridge rectifier circuit.

[0059] The rectifier circuit 4 can convert the three-phase alternating current output by the three-phase wireless transmission circuit 3 into three-phase direct current, and can rectify each phase of the alternating current separately to obtain the rectified direct current of each phase of the alternating current.

[0060] For example, Figure 1 As shown, the rectifier circuit 4 may include three rectifier circuits, each rectifier circuit is connected to a receiving end 302 of the three-phase wireless transmission circuit 3, each receiving end 302 corresponds to a rectifier circuit, and the rectifier circuits rectify the alternating current output by the respective connected receiving ends to obtain direct current.

[0061] The induction motor M is connected to a rectifier circuit 4. The three-phase DC power generated by the rectifier circuit is electrically connected to the three stators of the induction motor. This three-phase DC power is used to drive the three-phase induction motor. The three-phase DC power has equal amplitude and frequency, an initial phase difference of 120 degrees, and a constant direction. However, the current magnitude varies over time, generating a changing magnetic field that drives the induction motor.

[0062] The sampling circuit 5 is electrically connected to the three stators of the induction motor and is used to collect current signals flowing through the three stators.

[0063] For example, if the three stators of an induction motor are a, b, and c, the current signals collected may include i a 、i b and i c .

[0064] The structure of the sampling circuit 5 is not limited, and any circuit capable of sampling the currents of the three stators may be used.

[0065] The controller 6 is electrically connected to the sampling circuit 5 and is used to adjust the working state of the inverter circuit 2 according to the current signal to adjust the frequency of the three-phase alternating current output by the inverter circuit 2. The frequency is used to control the speed of the induction motor.

[0066] The controller 6 can be configured according to i a 、i b and i c The frequency of the three-phase AC power output by inverter circuit 2 is adjusted by adjusting the open and closed states of the controlled switches in inverter circuit 2 accordingly. Since the frequency of the three-phase DC power rectified by rectifier circuit 4 is the same as the frequency of the three-phase AC power output by inverter circuit 2, the frequency of the three-phase DC power can be adjusted by adjusting the frequency of the three-phase AC power output by inverter circuit 2. When the frequency of the three-phase DC power changes, the speed of the induction motor also changes, thereby achieving speed regulation of the induction motor.

[0067] The structure of the controller 6 is not limited, as long as it can realize the above functions. For the specific structure, please refer to the description of the controller 6 in the subsequent embodiments.

[0068] The controller 6 can control the working state of the inverter circuit 2, adjust the frequency of the AC power output by the inverter circuit 2 by adjusting the frequency and switch state of the switch in the inverter circuit 2, and then transmit the AC power to the rectifier circuit 4 through the three-phase wireless transmission circuit 3. The three-phase DC power obtained after rectification by the rectifier circuit 4 drives the induction motor to rotate. The speed and rotation direction of the induction motor can be adjusted by controlling the inverter circuit 2 by the controller 6.

[0069] For example, the controller 6 may output control signals for each controlled switch in the inverter circuit 2, such as Figure 1 As shown, the inverter circuit 2 includes six controlled switches. The controller 6 can generate six control signals, one of which controls one controlled switch. S1 to S6 control controlled switches Sw1 to Sw6, respectively. S1 controls controlled switch Sw1, S2 controls controlled switches Sw2, and S6 controls controlled switch Sw6.

[0070] The control circuit in this solution uses three-phase direct current to control the rotation of an induction motor, adjusting its speed and direction. The control circuit is simple in structure, with relatively few components between the wireless transmission transceiver circuit and the induction motor. It does not include any microcontroller, motor driver, controlled switch, rotor position sensor, battery, or power cord. This control circuit effectively reduces maintenance costs while ensuring zero-voltage switching and efficient system operation, improving control efficiency.

[0071] In one embodiment, reference Figure 1 , the motor control circuit further includes:

[0072] The compensation circuit is located between the transmitting end 301 and the inverter circuit 2; and / or, between the receiving end 302 and the rectifier circuit 4, and is used to reduce the reactive power of the inverter circuit.

[0073] The structure of the compensation circuit is not limited, and can be a capacitor or a circuit composed of a capacitor and an inductor, etc., which has the function of storing energy and reducing the reactive power of the inverter circuit 2, ensuring that the voltage output is independent of the load. Figure 1 In FIG, for the sake of illustration, the compensation circuit is represented by a capacitor.

[0074] The compensation circuit can include two parts, including a first compensation circuit and a second compensation circuit. The transmitter end of the first compensation circuit can be connected to the receiver end of the inverter circuit 2, and the receiver end of the first compensation circuit can be connected to the transmitter end of the three-phase wireless transmission circuit 3, that is, located between the inverter circuit 2 and the three-phase wireless transmission circuit 3. The transmitter end of the second compensation circuit can be connected to the receiver end of the three-phase wireless transmission circuit 3, and the receiver end of the second compensation circuit is connected to the rectifier circuit 4, that is, located between the three-phase wireless transmission circuit 3 and the rectifier circuit 4.

[0075] Exemplarily, the first compensation circuit may include a primary compensation circuit 701, which is located on the transmitting coil side of the three-phase wireless transmission circuit 3, between the transmitting coil and the inverter circuit 2, with the transmitting end and receiving end of the first compensation circuit respectively connected to the transmitting coil and the inverter circuit 2. The second compensation circuit includes a secondary compensation circuit 702, which is located on the receiving coil side of the three-phase wireless transmission circuit 3, between the receiving coil and the rectifier circuit 4, with the transmitting end and receiving end of the second compensation circuit respectively connected to the receiving coil and the rectifier circuit 4.

[0076] For example, Figure 1 As shown, the three-phase wireless transmission circuit 3 includes three sets of transceiver coils, each of which includes a transmitting coil and a receiving coil. The first compensation circuit may include three first compensation sub-circuits, each connected to one end of a transmitting coil. The first compensation sub-circuit is located between the transmitting coil and the inverter circuit 2. Each of the three transmitting coils is connected to a first compensation sub-circuit.

[0077] For example, Figure 1 As shown, the second compensation circuit may include three second compensation sub-circuits, each second compensation sub-circuit is connected to one end of a receiving coil, and the second compensation sub-circuit is located between the receiving coil and the rectifier circuit 4. Each of the three receiving coils is connected to a second compensation sub-circuit.

[0078] In one embodiment, the motor control circuit further includes:

[0079] a first wireless communication circuit 8, electrically connected to the sampling circuit 5, for sending a current signal;

[0080] The second wireless communication circuit 9 is wirelessly connected to the first wireless communication circuit 8 and electrically connected to the controller, and is used to receive the current signal and send the current signal to the controller 6.

[0081] like Figure 1As shown, the first wireless communication circuit 8 can be located away from the receiving end of the three-phase wireless transmission circuit 3 and closer to the induction motor M, i.e., on the side where the receiving end of the three-phase wireless transmission circuit 3 is located. The second wireless communication circuit 9 can be located closer to the inverter circuit 2 and away from the induction motor, i.e., on the side where the transmitting end of the three-phase wireless transmission circuit 3 is located. When the receiving end and the transmitting end of the three-phase wireless transmission circuit 3 are separated, the second wireless communication circuit 9 can be separated from the first wireless communication circuit 8, eliminating the need for wired transmission.

[0082] Illustratively, the first wireless communication circuit 8 may be a wireless communication receiving module having a wireless signal receiving function, and the second wireless communication circuit 9 may be a wireless communication sending module having a wireless signal sending function. The specific circuit structure is not limited.

[0083] In one embodiment, the motor control circuit further includes:

[0084] Drive circuit 10 is connected to the receiving end of controller 6 and is used to amplify the power of the control signal. The amplified control signal is used to control the operating state of the inverter circuit. The circuit structure of drive circuit 10 can be determined according to actual needs; any circuit with power amplification can be used. The amplified control signal facilitates controlling the state of each controlled switch in inverter circuit 2.

[0085] In one embodiment, the motor control circuit further includes a filter circuit located between the rectifier circuit and the induction motor, with a transmitting end connected to a receiving end of the rectifier circuit, and a receiving end connected to the induction motor. The filter circuit can perform a filtering function.

[0086] In one embodiment, reference Figure 2 , is a schematic diagram of a controller, the controller 6 includes:

[0087] The first subtractor 601 is used to calculate the difference between the stator current of each stator and the preset current to obtain a first difference value corresponding to each stator current; wherein each stator current corresponds to its own preset current.

[0088] The proportional-integral controller 602 is connected to the receiving end of the subtractor and is used to perform proportional-integral processing on the first difference to obtain a first modulation wave instruction signal of the inverter circuit corresponding to each stator current.

[0089] The sinusoidal pulse frequency modulator 603 is connected to the receiving end of the proportional-integral controller, and the receiving end of the sinusoidal pulse frequency modulator is connected to the transmitting end of the sinusoidal pulse frequency modulator, and is used to generate the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time based on each first modulation wave instruction signal and the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator last time.

[0090] The pulse wave generator 604 is connected to the receiving end of the sinusoidal pulse frequency modulator and is used to generate a control signal for the inverter circuit according to each second modulation wave instruction signal.

[0091] After receiving the current of each stator, the controller 6 can subtract the current of each stator from the corresponding preset current through the first subtractor 601 according to the current of each stator and the corresponding preset current, to obtain a first difference corresponding to each stator current.

[0092] For example, if the three stators are a, b and c, the stator current of stator a is i a , the stator current of stator b is i b , the stator current of stator c is i c The preset current corresponding to stator a is i a * , the preset current corresponding to stator b is i b * , the preset current corresponding to stator c is i c * . The first subtractor 601 is used to respectively a The corresponding preset current i a * Do the difference and get i a and i a * The first subtractor 601 is used to calculate the first difference between i and b The corresponding preset current i b * Do the difference and get i b and i b * The first subtractor 601 is used to calculate the first difference between i and c The corresponding preset current i c * Do the difference and get i c and i c * The first difference between .

[0093] In one embodiment, the preset current i a * 、ib * and i c * It can be a three-phase DC saddle wave current signal, that is, each preset current is a DC saddle wave current, the waveform is as follows Figure 2 The leftmost waveform in .

[0094] For example, Figure 2 As shown, the preset current i a * 、i b * and i c * The amplitudes are equal, the frequencies are the same, and the initial phases differ by 120 degrees.

[0095] In one embodiment, when the induction motor rotates in a first direction, such as forward rotation, i a * It can be expressed by formula (1):

[0096]

[0097] i b * It can be expressed by formula (2):

[0098]

[0099] i c * It can be expressed by formula (3):

[0100]

[0101] When the induction motor rotates in the second direction, the first direction is opposite to the second direction, such as reverse rotation, and any two phases of the three-phase currents can be interchanged, that is, two of the three preset currents can be interchanged.

[0102] For example, the preset current i b * and i c * The values ​​of i are swapped. a * It can be expressed by formula (4):

[0103]

[0104] i b * It can be expressed by formula (5):

[0105]

[0106] i c * It can be expressed by formula (6):

[0107]

[0108] Where, I in formula (1) to formula (6) m represents the preset rated current, ω represents the angular velocity, which may be equal to 2πf, and f represents the frequency of the alternating current.

[0109] For example, the current i can also be preset b * and i a * The values ​​of i can also be swapped. a * and i c * The values ​​are swapped.

[0110] For example, the preset current i a * 、i b * and i c * The value of can be determined according to the rotation direction of the induction motor through the above formulas (1) to (6).

[0111] Of course, the above formulas (1) to (6) are only examples, and the preset current i can also be determined by other methods. b * and i a * The value of .

[0112] After obtaining the first differences corresponding to the three stator currents in the three-phase induction motor M through the first subtractor 601, the proportional-integral controller 602 performs proportional-integral processing on each first difference to obtain the first modulation wave command signal of the inverter circuit corresponding to each stator current.

[0113] Proportional-integral controller 602 a and i a * The first difference between the two is proportionally integrated to obtain the first modulation wave command signal δ of phase a corresponding to stator a. a * , the proportional-integral controller 602 is used to control i b and i b * The first difference between the two is proportionally integrated to obtain the first modulation wave command signal δ of phase b corresponding to stator b. b * , the proportional-integral controller 602 is used to control ic and i c * The first difference between the two is proportionally integrated to obtain the first modulation wave command signal δ of the c phase corresponding to the stator c. c * .

[0114] For example, the proportional integral function can be expressed as: * =k p +k i / s,k i is the integral gain, s is the complex frequency domain variable, k p The first modulation wave instruction signal output by the proportional-integral controller 602 may include a gain signal.

[0115] Exemplarily, each first modulated wave instruction signal may be an output signal that changes periodically.

[0116] In getting δ a * , δ b * and δ c * After that, the sine pulse frequency modulator 603 modulates the δ a * , δ b * and δ c * Modulate to generate each first modulation wave instruction signal δ a * , δ b * and δ c * The corresponding second modulation wave command signal.

[0117] The sinusoidal pulse frequency modulator 603 may have a receiving end, which may output a first modulation wave instruction signal δ a * , δ b * and δ c * The corresponding second modulation wave command signal δ a , δ b and δ c , δ a * The corresponding second modulation wave command signal δ a , δ b * The corresponding second modulation wave command signal δ b , δ c * The corresponding second modulation wave command signal δc .

[0118] The sinusoidal pulse frequency modulation (SPFM) 603 also has a transmitting end, which is used to receive the signal output by the proportional-integral controller 602 and the signal output by the sinusoidal pulse frequency modulator 603 itself. The sinusoidal pulse frequency modulator 603 adjusts the signal output by the sinusoidal pulse frequency modulator 603 according to the signal output by itself and the signal output by the proportional-integral controller 602.

[0119] The sinusoidal pulse frequency modulator 603 can generate the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator 603 this time based on each first modulation wave instruction signal and the second modulation wave instruction signal corresponding to each first modulation wave instruction signal output by the sinusoidal pulse frequency modulator 603 last time.

[0120] For example, the sinusoidal pulse frequency modulator 603 outputs the δ a * and the δ outputted by the sine pulse frequency modulator 603 last time a Adjust the δ of this output a The sinusoidal pulse frequency modulator 603 is based on the δ output by the proportional integral controller 602. b * and the δ outputted by the sine pulse frequency modulator 603 last time b Adjust the δ of this output b The sinusoidal pulse frequency modulator 603 is based on the δ output by the proportional integral controller 602. c * and the δ outputted by the sine pulse frequency modulator 603 last time c Adjust the δ of this output c .

[0121] Exemplarily, the first modulated wave instruction signal serves as a reference signal of the second modulated wave instruction signal and is used to adjust the second modulated wave instruction signal.

[0122] Exemplarily, the initial values ​​of the first modulation wave instruction signals output by the sinusoidal pulse frequency modulator 603 are all 0.

[0123] In one embodiment, the second modulation wave instruction signal is used to indicate the ratio of the fundamental wave separation of the output voltage of the inverter circuit 2 to the rated voltage output by the inverter circuit 2 .

[0124] For example, the second modulation wave command signal δ aThe second modulation wave instruction signal δ represents the ratio of the fundamental component of the one-phase AC voltage corresponding to the stator a output by the inverter circuit 2 to the rated voltage. b The second modulation wave instruction signal δ represents the ratio of the fundamental component of the one-phase AC voltage corresponding to stator b output by the inverter circuit 2 to the rated voltage. c It represents the ratio of the fundamental component of the one-phase AC voltage corresponding to the stator c output by the inverter circuit 2 to the rated voltage. Each phase of the AC output by the inverter circuit corresponds to its own rated voltage.

[0125] In one embodiment, the sinusoidal pulse frequency modulator 603 is a first-order, second-order, third-order, or multi-order Delta-Sigma (Delta-Sigma) modulator.

[0126] Exemplarily, the sinusoidal pulse frequency modulator 603 is a first-order delta-sigma modulator.

[0127] After obtaining each second modulation wave instruction signal, the pulse wave generator 604 generates a control signal for the inverter circuit 2 based on each second modulation wave instruction signal. This control signal can be a pulse signal with a value of 1 or 0, where 1 represents a high level and 0 represents a low level, and is used to control the conduction or closing of the controlled switch in the inverter circuit 2.

[0128] The controller in this embodiment can realize frequency-reducing soft switching operation of the three-phase inverter, reduce the equivalent switching frequency of the inverter circuit, reduce system switching loss and average switching frequency, and thus improve system efficiency.

[0129] In one embodiment, reference Figure 2 , the sinusoidal pulse frequency modulator 603 comprises:

[0130] The second subtractor 6031 is connected to the receiving end of the proportional-integral controller and the receiving end of the sinusoidal pulse frequency modulator, and is used to perform a difference between each first modulation wave instruction signal and the corresponding second modulation wave instruction signal to obtain a second difference value corresponding to each first modulation wave instruction signal.

[0131] The integral controller 6032 is connected to the receiving end of the second subtractor, and is used to perform integration processing on each second difference to obtain an integral signal corresponding to each second difference.

[0132] The quantizer 6033 is connected to the receiving end of the integral controller and is used to perform quantization processing on each integral signal to obtain a quantized signal corresponding to each integral signal.

[0133] The variable-period zero-order holder 6034 is connected to the receiving end of the quantizer and is used to obtain each second modulation wave instruction signal according to each quantization signal and the quantization cycle number of the quantizer.

[0134] After obtaining each first modulation wave instruction signal, the second subtractor 6031 can perform a subtraction between the first modulation wave instruction signal and the second modulation wave instruction signal corresponding to the first modulation wave instruction signal to obtain a second difference value. The second difference value can be expressed as u, u=δ*-δ.

[0135] For example, the second subtractor 6031 can be used to generate the first modulation wave instruction signal δ a * and δ a Do the difference and get δ a * and δ a The corresponding second difference u a The second subtractor 6031 can be used to subtract the first modulation wave instruction signal δ b * and δ b Do the difference and get δ b * and δ b The corresponding second difference u b The second subtractor 6031 can be used to subtract the first modulation wave instruction signal δ c * and δ c Do the difference and get δ c * and δ c The corresponding second difference u c .

[0136] After obtaining each second difference, each second difference is integrated by the integral controller 6032 to obtain an integral signal corresponding to each second difference. The integral signal may be a periodically changing signal, such as a periodically changing continuous signal.

[0137] For example, the integral signal can be represented by y, and the integral controller 6032 can be used to calculate the second difference u a Perform integration processing to obtain the integral signal y a , for the second difference u b Perform integration processing to obtain the integral signal y b , for the second difference u c Perform integration processing to obtain the integral signal y c .

[0138] The integration process can be integrated using the following formula (7):

[0139] y=Ku / s (7)

[0140] Wherein, K is the integral coefficient of the integral controller, s represents the Laplace operator, s=jω0, j represents the imaginary unit, and ω0 represents the angular velocity.

[0141] The integral signal of each second difference can be obtained by formula (7).

[0142] The quantizer 6033 then quantizes each integrated signal and converts the integrated signal into a discrete digital signal. The quantizer has multiple different preset values ​​m, which are determined based on the second difference. The m output by the quantizer 6033 is the quantized signal. The preset value m represents the odd-order harmonics of the fundamental wave of the output voltage of the inverter circuit 2, and is expressed by the following formula (8):

[0143] m=1 / (2n±1) (8)

[0144] Wherein, n is a natural number.

[0145] Exemplarily, the preset value m is obtained by the quantizer 6033 by performing Fourier transform on the integrated signal.

[0146] In one embodiment, the quantizer 6033 further has a quantization cycle number N, which can be determined according to the quantization signal output by the quantizer 6033.

[0147] For example, the quantized signal is represented by q, and q can be determined by the following formula (9):

[0148]

[0149] Determine N using the following formula (10):

[0150]

[0151] The 1, 1 / 3, 1 / 5, and 1 / 7 in formula (9) are the preset values ​​m set in the quantizer. After determining q, N can be determined using formula (10).

[0152] After obtaining the quantized signal, the variable-period zero-order holder 6034 is used to obtain each second modulation wave instruction signal according to each quantized signal and the number of quantized cycles of the quantizer.

[0153] Exemplarily, the variable-period zero-order holder 6034 is used to sample and hold the quantized signal output by the quantizer 6033, maintain q for N half-wave periods, and then output q that remains unchanged for N half-wave periods.

[0154] Exemplarily, the initial value output by the variable-period zero-order holder 6034 is 0.

[0155] Exemplarily, the receiving end of the variable-period zero-order holder 6034 is connected to the transmitting end of the pulse wave generator 604 and also to the transmitting end of the second subtractor 6031. In this way, the second modulation wave instruction signal to be outputted by the variable-period zero-order holder 6034 can be adjusted based on the second modulation wave instruction signal previously outputted by the variable-period zero-order holder 6034 and the first modulation wave instruction signal corresponding to the second modulation wave instruction signal. This process forms a closed-loop feedback loop, forming a cyclic process.

[0156] Exemplarily, the variable-period zero-order holder 6034 may output q in the following manner:

[0157] Define a variable k and set its initial value to 0; in each control cycle (including the control cycle of the controlled switch in the inverter circuit), if k is less than or equal to 0, then δ = q, k = N-1; if k is greater than 0, then k = k-1.

[0158] In one embodiment, reference Figure 3 , is a schematic diagram of a pulse wave generator 604 generating a control signal according to each second modulation wave instruction signal. The second modulation wave instruction signal δ is used as an example for illustration.

[0159] Define variables A and k, and set their initial values ​​to 0. In each control cycle, if the input δ to the pulse wave generator 604 is 1, then A = 1-A, and k = 0. If δ is 1 / 3, then k = k-1; if k < 0, then A = 1-A, and k = 2. If δ is 1 / 5, then k = k-1; if k < 0, then A = 1-A, and k = 4. If δ is 1 / 7, then k = k-1; if k < 0, then A = 1-A, and k = 6. If δ is any other value, then A = 0. Ultimately, the output of the pulse wave generator, S = A. A is either 1 or 0.

[0160] The pulse wave generator generates control signals S1, S3, and S5 for the controlled switches Sw1, Sw3, and Sw5 in inverter circuit 2. Based on these signals, control signals S2, S4, and S6 for the controlled switches Sw2, Sw4, and Sw6 are determined. S2 = -S1, meaning S1 and S2 are complementary signals; S4 = -S3, meaning S3 and S4 are complementary signals; and S6 = -S5, meaning S5 and S6 are complementary signals. This generates control signals for each controlled switch in inverter circuit 2. Based on signals S1 through S6, each controlled switch in the three-phase inverter circuit 2 is turned on or off, thereby controlling the speed of the induction motor.

[0161] refer to Figure 4 , which is a simulation diagram of the motor speed. After the motor load increases, the speed of the induction motor decreases. The controller can control the speed of the induction motor by controlling the frequency of on and off of the controlled switch in the inverter circuit 2.

[0162] refer to Figure 5 , is a simulation diagram of each stator current in a motor, Figure 5 The following diagram shows the current waveforms of the three stators in an induction motor at two speeds. Phase A is the current input to stator a, phase B is the current input to stator b, and phase C is the current input to stator c. Three-phase DC power is input to the coils of the three stators in a three-phase induction motor. The three-phase DC power has equal amplitude, the same frequency, and an initial phase difference of 120 degrees, which can drive the induction motor.

[0163] Figure 5 In the six figures shown, the horizontal axis represents time, with a period of 0.02 seconds, and the vertical axis represents current magnitude. The two rotational speeds can include a first rotational speed and a second rotational speed, where the first rotational speed is lower than the second rotational speed. The first rotational speed can be a low speed, and the second rotational speed can be a high speed. At different rotational speeds, the amplitude of the DC current in the same phase varies, and so does the current magnitude.

[0164] refer to Figure 6a This is a simulation diagram of the current and voltage in the transmitting coil of the three-phase wireless transmission circuit 3. The horizontal axis represents time, and the vertical axis represents current. A square wave represents voltage, and a sine wave represents current.

[0165] refer to Figure 6b Schematic diagram of current simulation of the receiving coil in the three-phase wireless transmission circuit 3. The horizontal axis represents time, and the vertical axis represents current and voltage.

[0166] refer to Figure 7 , is a schematic diagram of a motor control method, which can be applied to the motor control circuit in any of the above embodiments, and includes:

[0167] S1, collects the currents in the three stators of the three-phase induction motor;

[0168] S2, determining a first difference between the current and a preset current; wherein the current of each stator corresponds to its own preset current;

[0169] S3, determining a first modulated wave command signal according to the first difference;

[0170] S4, generating a second modulation wave command signal corresponding to each first modulation wave command signal output by the sinusoidal pulse frequency modulator this time based on each first modulation wave command signal and the second modulation wave command signal corresponding to each first modulation wave command signal output by the sinusoidal pulse frequency modulator last time;

[0171] S5, generating a control signal for the inverter circuit according to each second modulation wave command signal output by the sinusoidal pulse frequency modulator this time;

[0172] S6, controlling the working state of the inverter circuit through the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, the frequency being used to control the speed of the induction motor.

[0173] The control process of the control method can refer to the embodiment of the controller part in the above control circuit, and will not be repeated here.

[0174] In one embodiment, S3, determining a first modulated wave instruction signal according to the first difference, includes:

[0175] A proportional-integral operation is performed on the first difference to obtain a first modulation wave instruction signal, and reference may be made to the embodiment of the proportional-integral controller of the control circuit part.

[0176] In one embodiment, reference Figure 8 , is a schematic diagram of obtaining a second modulation wave instruction signal, S4, obtaining the second modulation wave instruction signal according to the first modulation wave instruction signal, including:

[0177] S401 , performing a difference between each first modulated wave instruction signal and the corresponding second modulated wave instruction signal to obtain a second difference value corresponding to each first modulated wave instruction signal.

[0178] S402, integrating each second difference to obtain an integral signal corresponding to each second difference;

[0179] S403, performing quantization processing on each integrated signal to obtain a quantized signal corresponding to each integrated signal;

[0180] S404: Obtain each second modulation wave instruction signal according to each quantization signal and the number of quantization cycles of the quantizer.

[0181] For S401 to S404 , reference may be made to the contents of the corresponding embodiment of the sinusoidal pulse frequency modulator.

[0182] In one embodiment, reference Figure 9 , is a schematic diagram of a motor control device, the device comprising:

[0183] The acquisition module 100 is used to acquire the stator currents in the three stators of the three-phase induction motor;

[0184] A first determining module 200 is configured to determine a first difference corresponding to each of the stator currents based on the stator current and a preset current corresponding to each of the stator currents;

[0185] A second determining module 300 is configured to determine a first modulation wave command signal corresponding to each of the stator currents according to each of the first differences;

[0186] A third determining module 400 is configured to generate, based on each of the first modulation wave instruction signals and the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals previously output by the sinusoidal pulse frequency modulator, the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals currently output by the sinusoidal pulse frequency modulator;

[0187] A control signal generating module 500 is configured to generate a control signal for an inverter circuit according to each of the second modulation wave instruction signals outputted by the sinusoidal pulse frequency modulator this time;

[0188] The control module 600 is configured to control the working state of the inverter circuit through the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, wherein the frequency is used to control the rotational speed of the induction motor.

[0189] In one embodiment, the third determining module 400 includes:

[0190] a second difference determining unit, configured to perform a difference between each of the first modulated wave instruction signals and the corresponding second modulated wave instruction signal to obtain a second difference corresponding to each of the first modulated wave instruction signals;

[0191] an integrating unit, configured to perform an integration operation on each of the second differences to obtain an integrated signal corresponding to each of the second differences;

[0192] a quantization unit, configured to perform quantization processing on each of the integrated signals to obtain a quantized signal corresponding to each of the integrated signals;

[0193] The second modulation wave instruction signal generating unit is used to obtain each of the second modulation wave instruction signals according to the number of quantization cycles and each of the quantization signals.

[0194] It should be noted that the “first” and “second” in the embodiments of the present disclosure are only for the convenience of expression and distinction and have no other specific meanings.

[0195] In one embodiment, there are various types of three-phase wireless motors, including wireless DC motors, wireless stepper motors, wireless switched reluctance motors, wireless single-phase induction motors, and wireless brushless DC motors. Wireless DC motor systems contain carbon brushes and require regular maintenance; wireless stepper motor systems are difficult to increase in output power and torque, and their application prospects remain to be improved; wireless switched reluctance motor systems require a three-phase wireless energy transmission channel and rely on rotor position feedback for reliable control; and wireless single-phase induction motor systems require a switching power converter on the receiving side to achieve current commutation, but cannot achieve motor speed commutation. This makes the system complex and its reliability needs to be improved.

[0196] The wireless induction motor system transmits wireless motor drive information from a power transmitter to a power receiver, which then passes it on to the drive receiver of the wireless switch. This controls the wireless switch to form a wirelessly controlled motor drive, driving the motor. To reliably drive the wireless switches on both motor drives, the gallium nitride (GaN) inverter must be tuned alternately at two frequencies to inject drive information into the wireless power. The motor drive inverter can be wirelessly magnetically modulated to positive and negative drive, enabling bidirectional wireless motor motion and variable frequency speed regulation.

[0197] There are three main modulation methods for motor speed control: pulse width modulation (PWM), pulse density modulation (PDM), and pulse frequency modulation (PFM). PWM regulates the output voltage of a power converter by varying the pulse duty cycle while maintaining a constant switching frequency. This modulation strategy offers the advantage of high control accuracy, but requires the application of soft switching techniques to reduce switching losses. Otherwise, the power converter will operate in a high-frequency hard-switching state, severely reducing system efficiency. Pulse density modulation adjusts the system's output characteristics by controlling the presence or absence of high-frequency pulses while maintaining a constant switching frequency and 50% duty cycle. This modulation strategy offers the advantages of low switching frequency and soft switching, but introduces subharmonic oscillations into the output, resulting in relatively low control accuracy. PFM, as a new pulse modulation technique, has been extensively developed and utilized in the field of wireless charging. While maintaining a constant 50% duty cycle, the switching frequency is modulated according to a specific rule within a pair of switching frequencies. Typical frequency pairs include the fundamental frequency and the 1 / 3rd harmonic, or the 1 / 3rd and 1 / 5th harmonics. This modulation strategy combines many advantages, including low switching frequency, soft switching, high control accuracy, and high efficiency. Therefore, PFM's overall performance is superior to PWM and pulse density modulation. The novel zero voltage switching (ZVS) SPFM enables effective regulation of wireless motors, reducing average switching frequency and switching losses, thereby further improving system efficiency. Based on ZVS-SFPM technology, bidirectional speed regulation of wireless motors can be flexibly achieved, meeting the operational requirements of high reliability, high efficiency, and high power density for motors in systems such as electrified transportation, motor drives, and robotics, and has broad application prospects. In frequency-alternating magnetic resonance modulation, the use of ZVS-SPFM allows for flexible control of the inverter output to achieve power balancing, power regulation, and efficiency improvement during both forward and negative drive phases of the wireless motor.

[0198] In summary, the modulation scheme of radio motors has many problems in terms of research methods and parameter settings, which makes it difficult to meet the requirements of high-performance operation of radio motors.

[0199] In order to overcome the shortcomings of the above-mentioned three-phase wireless motor system topology, complex control, high maintenance cost, and high switching loss of the modulation method, the present invention provides a wireless drive system and device for a three-phase induction motor, which no longer uses a wireless motor driver and does not require communication, thereby simplifying the system complexity and improving the stability and reliability of the system.

[0200] To address the above technical issues, this embodiment provides a three-phase wireless unipolar induction motor system, comprising a controller, a drive circuit, a sampling circuit, a wireless communication transmitter module, a wireless communication receiver module, a DC source, a three-phase full-bridge inverter circuit, three identical wireless energy transmission devices, and a three-phase induction motor. The wireless energy transmission devices include a transmitter compensation circuit, a transmitter coil, a receiver coil, a receiver compensation circuit, a diode rectifier circuit, and a DC-side capacitor. The transmitter compensation circuit, the transmitter coil, the receiver coil, the receiver compensation circuit, the diode rectifier circuit, and the DC-side capacitor are sequentially connected. The DC source is connected to the three-phase inverter circuit; the midpoints of the three-phase inverter's bridge arms are respectively connected to the transmitters of the three identical wireless energy transmission devices; the receivers of the three identical wireless energy transmission devices are respectively connected to the three-phase induction motor; the three-phase induction motor, the sampling circuit, and the wireless communication transmitter module are sequentially connected; the wireless communication receiver module is connected to the controller; the controller is connected to the transmitter end of the drive circuit; and the drive circuit is used to drive the three-phase inverter circuit.

[0201] In one embodiment, the controller provided in this embodiment includes a sinusoidal pulse frequency modulation (SPFM), which includes the fundamental wave and odd-order harmonics (1 / (2n±1), n ​​is a natural number) of the resonant frequency of the wireless energy transmission system as the switching frequency of the modulation pulse; the SPFM modulator can be compared to sinusoidal pulse width modulation, generating a pulse sequence in which the fundamental wave amplitude changes according to the sinusoidal wave pattern; the SPFM modulator can use a first-order, second-order, third-order or multi-order Δ-Σ modulator to generate the required control pulse sequence; the generated control pulse sequence is used to control the inverter.

[0202] In one embodiment, a motor control method is provided, such as a wireless driving method for a three-phase unipolar induction motor, comprising the following steps:

[0203] (1) Sampling the stator current i of the three-phase induction motor a 、i b and i c and transmitted to the controller at the transmission end of the wireless energy transmission device through the wireless communication module.

[0204] (2) Given a three-phase DC saddle wave current command signal i a *、i b * and i c*, respectively, with the stator current i of the three-phase induction motor a 、i b and i c By making a difference, the modulation wave command signal δ of the three-phase inverter is obtained through the PI controller. a *、δ b * and δ c *; DC saddle wave current command signal i of three-phase inverter a *、i b * and i c *The equation is expressed as follows:

[0205] When the motor rotates forward, i a *、i b * and i c *for:

[0206]

[0207]

[0208]

[0209] When the motor reverses, any two phases of the three-phase current in abc can be interchanged. For example, the currents of phases b and c are interchanged, then i a *、i b * and i c * indicates the following:

[0210]

[0211]

[0212]

[0213] In the above formula, I m For a given rated current, ω = 2πf represents the angular velocity.

[0214] (3) According to the modulation wave command signal δ of the three-phase inverter a *、δ b * and δ c *, respectively adopt the SPFM modulator based on Δ-Σ to obtain the modulation wave signal δ of the three-phase inverter a , δ b and δ c The modulation process of the Δ-Σ based SPFM modulator is as follows:

[0215] Take one of the δ as an example to illustrate:

[0216] 1) Given a modulated wave command signal δ*, subtract it from the output δ of the SPFM modulator to obtain the input u of the integral controller, u = δ* - δ; wherein the initial value of the SPFM modulator output δ is 0.

[0217] 2) According to the input u of the integral controller, the output y of the integral controller is obtained, y=Ku / s; wherein K is the integral coefficient of the integral controller; s represents the Laplace operator, s=jω0, and j represents the imaginary unit.

[0218] 3) The output y of the integral controller is used as the input of the quantizer to obtain the output q of the quantizer and the number of quantization cycles N. The method of obtaining q and N based on y is as follows:

[0219]

[0220]

[0221] 4) According to the output q of the quantizer and the number of quantization cycles N, the output δ of the SPFM modulator is obtained.

[0222] The method is as follows: first define the variable k and set its initial value to 0; in each control cycle, if k is less than or equal to 0, then δ = q, k = N-1; if k is greater than 0, then k = k-1.

[0223] (4) According to the output δ of the SPFM modulator a , δ b and δ c , respectively, through the pulse wave generator, the switching signals of S1, S3 and S5 are obtained. Among them, the implementation method of the pulse wave generator is as follows:

[0224] Define variables A and k, and set their initial values ​​to 0. In each control cycle, if the pulse wave generator input δ is 1, then A = 1-A, and k = 0. If δ is 1 / 3, then k = k-1; if k < 0, then A = 1-A, and k = 2. If δ is 1 / 5, then k = k-1; if k < 0, then A = 1-A, and k = 4. If δ is 1 / 7, then k = k-1; if k < 0, then A = 1-A, and k = 6. For any other value of δ, then A = 0. Ultimately, the pulse wave generator's output S1 = A.

[0225] (5) According to the switching signals of S1, S3 and S5, the switching signals of S2, S4 and S6 are obtained; S2 = ~S1, S1 and S2 are complementary signals; S4 = ~S3, S3 and S4 are complementary signals; S6 = ~S5, S5 and S6 are complementary signals.

[0226] (6) According to the control signals of S1 to S6, the controlled switches of the three-phase inverter are controlled to be turned on or off, thereby controlling the speed of the induction motor.

[0227] The technical solution of this embodiment has the following beneficial effects:

[0228] The solution of this embodiment uses an SPFM modulator to control the output of a three-phase DC saddle wave current from a wireless energy transmission device, directly driving a three-phase induction motor, enabling the three-phase AC motor to achieve forward and reverse rotation and speed regulation. This enables frequency-reduced soft-switching operation of the three-phase inverter, reducing system switching losses and average switching frequency, thereby improving system efficiency. The wireless energy transmission system receiver of the present invention eliminates the need for controllable switching devices, drive circuits, microcontrollers, and batteries, addressing the complex and high maintenance costs of wireless drivers for three-phase induction motors. This embodiment achieves high integration, lightweighting, and miniaturization of the wireless energy transmission system receiver and motor.

[0229] Figure 10 FIG2 is a block diagram of a terminal device according to an exemplary embodiment. For example, the terminal device may be a vehicle, a machine tool, or other terminal device having an induction motor.

[0230] Reference Figure 10 The terminal device may include one or more of the following components: a processing component 802 , a memory 804 , a power component 806 , a multimedia component 808 , an audio component 810 , an input / output (I / O) interface 812 , a sensor component 814 , and a communication component 816 .

[0231] The processing component 802 generally controls the overall operation of the terminal device, such as operations associated with presentations, phone calls, data communications, camera operation, and recording. The processing component 802 may include one or more processors 820 to execute instructions to perform all or part of the steps of the aforementioned method. Furthermore, the processing component 802 may include one or more modules to facilitate interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate interaction between the multimedia component 808 and the processing component 802.

[0232] The memory 804 is configured to store various types of data to support operations on the terminal device. Examples of such data include instructions for any application or method operating on the terminal device, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0233] The power component 806 provides power to various components of the terminal device. The power component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the terminal device.

[0234] The multimedia component 808 includes a screen that provides an output interface between the terminal device and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen can be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor can not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the terminal device is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera can receive external multimedia data. Each front camera and rear camera can be a fixed optical lens system or have a focal length and optical zoom capability.

[0235] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), which is configured to receive external audio signals when the terminal device is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0236] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as a keyboard, click wheel, buttons, etc. These buttons may include but are not limited to: a home button, volume buttons, a start button, and a lock button.

[0237] The sensor assembly 814 includes one or more sensors for providing status assessments of various aspects of the terminal device. For example, the sensor assembly 814 can detect the open / closed state of the terminal device, the relative positioning of components, such as the display and keypad of the terminal device. The sensor assembly 814 can also detect changes in the position of the terminal device or a component of the terminal device, the presence or absence of user contact with the terminal device, the orientation or acceleration / deceleration of the terminal device, and temperature changes of the terminal device. The sensor assembly 814 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor assembly 814 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 may also include an accelerometer, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0238] The communication component 816 is configured to facilitate wired or wireless communication between the terminal device and other devices. The terminal device can access a wireless network based on a communication standard, such as Wi-Fi, 4G or 5G, or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0239] In an exemplary embodiment, the terminal device may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above method.

[0240] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0241] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A motor control circuit, characterized in that: include: DC power supply; an inverter circuit, connected to the DC power supply, for converting the DC power provided by the DC power supply into three-phase AC power; A three-phase wireless transmission circuit having a wirelessly connected transmitter and receiver; wherein the transmitter is connected to the inverter circuit and is used to transmit the electric energy of the three-phase alternating current to the receiver; the receiver is used to receive the electric energy sent by the transmitter and generate three-phase alternating current; a rectifier circuit connected to the receiving end and configured to convert the three-phase alternating current generated by the receiving end into three-phase direct current; wherein the three-phase direct current is configured to drive a three-phase induction motor; the three-phase direct current has equal amplitude, the same frequency, an initial phase difference of 120 degrees, and a constant direction of current, but changes in magnitude over time; a sampling circuit electrically connected to the three stators of the induction motor and configured to collect current signals flowing through the three stators; A controller is electrically connected to the sampling circuit and is used to adjust the working state of the inverter circuit according to the current signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, and the frequency is used to control the speed of the induction motor.

2. The circuit according to claim 1, wherein: The controller includes: a first subtractor, configured to subtract a stator current of each stator from a preset current to obtain a first difference corresponding to each stator current; wherein each stator current corresponds to its own preset current; a proportional-integral controller connected to the receiving end of the subtractor, configured to perform proportional-integral processing on each of the first differences to obtain a first modulation wave command signal of the inverter circuit corresponding to each of the stator currents; a sinusoidal pulse frequency modulator connected to a receiving end of the proportional-integral controller, and the receiving end of the sinusoidal pulse frequency modulator connected to a transmitting end of the sinusoidal pulse frequency modulator, for generating, based on each of the first modulation wave instruction signals and the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals previously output by the sinusoidal pulse frequency modulator, a second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals currently output by the sinusoidal pulse frequency modulator; The pulse wave generator is connected to the receiving end of the sinusoidal pulse frequency modulator and is used to generate the control signal of the inverter circuit according to each second modulation wave instruction signal output by the sinusoidal pulse frequency modulator this time.

3. The circuit according to claim 2, characterized in that The sinusoidal pulse frequency modulator comprises: a second subtractor, connected to a receiving end of the proportional-integral controller and a receiving end of the sinusoidal pulse frequency modulator, for performing a subtraction between each of the first modulation wave instruction signals and the corresponding second modulation wave instruction signal to obtain a second difference value corresponding to each of the first modulation wave instruction signals; an integral controller connected to the receiving end of the second subtractor, and configured to perform integration processing on each of the second differences to obtain an integral signal corresponding to each of the second differences; a quantizer connected to the receiving end of the integral controller, and configured to perform quantization processing on each of the integral signals to obtain a quantized signal corresponding to each of the integral signals; The variable-period zero-order holder is connected to the receiving end of the quantizer and is used to obtain each of the second modulation wave instruction signals according to each of the quantization signals and the number of quantization cycles of the quantizer.

4. The circuit according to claim 1, wherein: The three-phase wireless transmission circuit includes: Three groups of parallel transceiver coils; wherein the transceiver coils include: a transmitting coil and a receiving coil, the transmitting coil serves as the transmitting end, and the receiving coil serves as the receiving end.

5. The circuit according to claim 1, wherein: The circuit further comprises: A compensation circuit is located between the transmitting end and the inverter circuit; and / or between the receiving end and the rectifier circuit, and is used to reduce the reactive power of the inverter circuit.

6. The circuit according to claim 1, wherein: The inverter circuit is a three-phase inverter circuit.

7. The circuit according to claim 1, wherein: The circuit further comprises: a first wireless communication circuit, electrically connected to the sampling circuit, and configured to send the current signal; The second wireless communication circuit is wirelessly connected to the first wireless communication circuit and electrically connected to the controller, and is configured to receive the current signal and send the current signal to the controller.

8. The circuit according to claim 2, characterized in that The circuit further comprises: The driving circuit is connected to the receiving end of the controller and is used to power amplify the control signal; wherein the control signal after power amplification is used to control the working state of the inverter circuit.

9. A motor control method, characterized in that: Applied to the motor control circuit according to any one of claims 1 to 8, the method comprising: collecting stator currents in three stators of the three-phase induction motor; Determining a first difference corresponding to each of the stator currents according to the stator current and a preset current; wherein each of the stator currents corresponds to its own preset current; Determining a first modulation wave command signal corresponding to each of the stator currents according to each of the first differences; generating, according to each of the first modulation wave instruction signals and the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals outputted last by the sinusoidal pulse frequency modulator, the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals outputted this time by the sinusoidal pulse frequency modulator; generating a control signal for an inverter circuit according to each of the second modulation wave instruction signals outputted this time by the sinusoidal pulse frequency modulator; The operating state of the inverter circuit is controlled by the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit. The frequency is used to control the rotational speed of the induction motor.

10. The method according to claim 9, characterized in that The determining, according to each of the first differences, the first modulation wave command signal corresponding to each of the stator currents includes: Proportional integral operation is performed on each of the first differences to obtain the first modulation wave command signal corresponding to each of the stator currents.

11. The method according to any one of claim 9, characterized in that: The obtaining of the corresponding second modulation wave instruction signal according to each of the first modulation wave instruction signals includes: performing a subtraction between each of the first modulated wave instruction signals and the corresponding second modulated wave instruction signal to obtain a second difference value corresponding to each of the first modulated wave instruction signals; performing an integration operation on each of the second differences to obtain an integrated signal corresponding to each of the second differences; Performing quantization processing on each of the integrated signals to obtain a quantized signal corresponding to each of the integrated signals; Each of the second modulation wave instruction signals is obtained according to the number of quantization cycles and each of the quantization signals.

12. A motor control device, characterized in that: include: An acquisition module for acquiring stator currents in three stators of a three-phase induction motor; a first determining module, configured to determine a first difference corresponding to each of the stator currents based on the stator current and a preset current corresponding to each of the stator currents; a second determining module, configured to determine a first modulation wave command signal corresponding to each of the stator currents according to each of the first differences; a third determining module, configured to generate, based on each of the first modulation wave instruction signals and the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals outputted last by the sinusoidal pulse frequency modulator, the second modulation wave instruction signal corresponding to each of the first modulation wave instruction signals outputted last by the sinusoidal pulse frequency modulator; a control signal generating module, configured to generate a control signal for an inverter circuit according to each of the second modulation wave instruction signals outputted this time by the sinusoidal pulse frequency modulator; The control module is used to control the working state of the inverter circuit through the control signal to adjust the frequency of the three-phase alternating current output by the inverter circuit, and the frequency is used to control the speed of the induction motor.

13. A terminal device, characterized in that: include: A processor and a memory for storing executable instructions capable of running on the processor, wherein: When the processor is used to run the executable instructions, the executable instructions execute the method described in any one of claims 9 to 11.

14. A non-transitory computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the method according to any one of claims 9 to 11.

15. A terminal device, characterized in that: include: The motor control circuit according to any one of claims 1 to 8.

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