Electric machine, method and system for starting the same, controller, compressor and electric appliance

Abstract

The present disclosure relates to an electric machine, a starting method and system thereof, a controller, a compressor and an electrical appliance. The method comprises: in a zero-speed starting phase of the electric machine, injecting a square wave voltage signal of a predetermined frequency into the electric machine to drive the electric machine to rotate; obtaining a response current by subtracting a current value of a previous time from a current current value of the electric machine; determining a first rotor position angle of the electric machine according to the response current; and in a next control cycle, performing closed-loop control of a current loop and a speed loop on the electric machine by using the first rotor position angle. The present disclosure can realize true zero-speed closed-loop starting and enable the compressor to directly enter a closed-loop starting state from a completely stationary state.

Description

Technical Field

[0001] This disclosure relates to the field of motor control technology, and in particular to a motor and its starting method and system, controller, compressor and electrical equipment. Background Technology

[0002] Air conditioning compressors generally use permanent magnet synchronous motors as built-in motors. Due to the harsh operating environment inside the compressor, which involves high temperature, high pressure, and refrigerant, it is difficult to install reliable rotor position sensors (such as Hall sensors, encoders, or rotary transformers) inside. Therefore, most compressors adopt a sensorless control strategy. Summary of the Invention

[0003] The inventors discovered through research that related sensorless control technologies face the following significant technical problems that urgently need to be addressed under zero-speed and ultra-low-speed conditions: Rotor position information cannot be extracted at zero speed. While sensorless algorithms (such as sliding mode observers and flux linkage observers based on back EMF) are relatively mature and reliable in medium- and high-speed operation, at low speeds, because the motor's back EMF is proportional to its speed, the back EMF signal is so weak as to be difficult to detect at zero speed and ultra-low speeds (e.g., below 300 rpm). Consequently, the observers lose a valid input signal and cannot accurately obtain rotor position information, making it difficult for sensorless control technology to achieve closed-loop start-up under zero-speed conditions.

[0004] In view of at least one of the above technical problems, this disclosure provides a motor and its starting method and system, controller, compressor and electrical equipment, which can realize true zero-speed closed-loop start and can directly enter the closed-loop start state from a completely stationary state of the compressor.

[0005] According to one aspect of this disclosure, a method for starting a motor is provided, comprising: During the zero-speed start-up phase of the motor, a square wave voltage signal of a predetermined frequency is injected into the motor to drive the motor to rotate. The response current is obtained by subtracting the current value of the motor at the current moment from the current value at the previous moment. The first rotor position angle of the motor is determined based on the response current; In the next control cycle, the motor is subjected to closed-loop control of current loop and speed loop using the first rotor position angle.

[0006] In some embodiments of this disclosure, the motor starting method further includes: During the first operating phase of the motor, the rotor position angle of the previous control cycle is received as feedback, wherein the motor speed is greater than 0 during the first operating phase. The steps include: injecting a square wave voltage signal of a predetermined frequency into the motor; subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; obtaining the first rotor position angle of the motor based on the response current; and performing closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

[0007] In some embodiments of this disclosure, the motor starting method further includes: During the first operating phase of the motor, the rotor position angle of the previous control cycle is received as feedback, wherein the motor speed is greater than 0 during the first operating phase. A square wave voltage signal of a predetermined frequency is injected into the motor. Get the motor speed; Determine whether the motor speed is less than a predetermined threshold; When the motor speed is less than the predetermined threshold, the following steps are performed: subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; determining the first rotor position angle of the motor based on the response current; and performing closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

[0008] In some embodiments of this disclosure, the motor starting method further includes: If the motor speed is not less than the predetermined threshold, the difference between the current value of the motor at the current moment and the current value at the previous moment is calculated to obtain the response current. The first rotor position angle of the motor is determined based on the response current; Start the back EMF observer and use the back EMF observer to determine the second rotor position angle of the motor; The third rotor position angle is determined based on the first rotor position angle and the second rotor position angle; In the next control cycle, the motor is controlled in a closed loop using the third rotor position angle for both current and speed loops.

[0009] In some embodiments of this disclosure, determining the third rotor position angle based on the first rotor position angle and the second rotor position angle includes: The first angle value is determined based on the product of the first rotor position angle and the first weight, wherein the first weight is greater than or equal to 0 and less than or equal to 1; The second angle value is determined based on the product of the second rotor position angle and the second weight, wherein the sum of the first weight and the second weight is 1; The third rotor position angle is determined based on the first angle value and the second angle value.

[0010] In some embodiments of this disclosure, the motor starting method further includes: During the first operating phase of the motor, the motor speed is gradually increased, and the first weight is gradually decreased from 1 to 0. Determine whether the first weight is 0; When the first weight is 0, the injection of a square wave voltage signal of a predetermined frequency into the motor is stopped.

[0011] In some embodiments of this disclosure, the motor starting method further includes: Acquire real-time data of the motor, wherein the real-time data includes real-time current, voltage, and speed data; Based on the real-time data, the current parameters of the motor are determined, wherein the parameters include at least one of resistance and inductance; The parameter changes of the motor are determined based on the current parameters of the motor and the motor parameters currently used by the back EMF observer. Determine whether the change in the parameter is greater than a predetermined value; If the parameter change value is greater than a predetermined value, the parameters of the back EMF observer are corrected.

[0012] In some embodiments of this disclosure, the back EMF observer is a sliding mode observer or an extended state observer.

[0013] In some embodiments of this disclosure, the parameters of the back EMF observer include at least one of the following: sliding mode observer gain, low-pass filter cutoff frequency, extended state observer gain, and extended state observer bandwidth.

[0014] In some embodiments of this disclosure, the predetermined frequency is greater than the normal rotation frequency of the motor, the square wave voltage signal is an alternating positive and negative square wave voltage signal, and the amplitude of the square wave voltage signal is less than the predetermined amplitude.

[0015] In some embodiments of this disclosure, determining the first rotor position angle of the motor based on the response current includes: The position deviation is obtained by demodulating the response current; The position deviation is processed by a phase-locked loop to determine the first rotor position angle of the motor.

[0016] In some embodiments of this disclosure, the closed-loop control of the motor using the first rotor position angle for both current and speed loops includes: The driving current and driving voltage of the motor are calculated based on the first rotor position angle, and the motor is driven to rotate. The new response current is obtained by subtracting the current value of the motor at the current moment from the current value at the previous moment. Based on the response current, a new first rotor position angle is determined.

[0017] In some embodiments of this disclosure, the motor is a compressor motor or a fan motor.

[0018] According to another aspect of this disclosure, a controller is provided, comprising: The voltage injection module is configured to inject a square wave voltage signal of a predetermined frequency into the motor during the zero-speed start-up phase of the motor, thereby driving the motor to rotate. The current difference module is configured to subtract the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; The position determination module is configured to determine the first rotor position angle of the motor based on the response current; The closed-loop control module is configured to perform closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

[0019] According to another aspect of this disclosure, a controller is provided, comprising: The memory is configured to store instructions; and A processor coupled to the memory is configured to execute the motor starting method as described in any of the above embodiments based on instructions stored in the memory.

[0020] According to another aspect of this disclosure, a motor starting system is provided, including a controller as described in any of the above embodiments.

[0021] According to another aspect of this disclosure, a compressor is provided, including a motor and a motor starting system as described in any of the above embodiments.

[0022] According to another aspect of this disclosure, a fan is provided, including a motor and a motor starting system as described in any of the above embodiments.

[0023] According to another aspect of this disclosure, an electrical device is provided, comprising at least one of a compressor as described in any of the above embodiments and a fan as described in any of the above embodiments.

[0024] According to another aspect of this disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions that, when executed by a processor, implement the motor starting method as described in any of the above embodiments.

[0025] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, it implements the motor starting method as described in any of the above embodiments.

[0026] This disclosure enables true zero-speed closed-loop start-up, allowing the compressor to directly enter the closed-loop start-up state from a completely stationary state. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of some embodiments of the motor starting method disclosed herein.

[0029] Figure 2 This is a schematic diagram of the high-frequency square wave injection signal waveform in some embodiments of this disclosure.

[0030] Figure 3 This is a schematic diagram illustrating the processing principle of high-frequency response current by a pure delay filter in some embodiments of this disclosure.

[0031] Figure 4 This is a schematic diagram of a closed-loop control method and system for a permanent magnet synchronous motor used in an air conditioning compressor, as described in some embodiments of this disclosure.

[0032] Figure 5 The following is a structural block diagram of the air conditioning compressor zero-speed closed-loop start control method and system in some embodiments of this disclosure.

[0033] Figure 6 This is a schematic diagram of some other embodiments of the motor starting method disclosed herein.

[0034] Figure 7 This is a schematic diagram of some embodiments of the motor starting method disclosed herein.

[0035] Figure 8 This is a schematic diagram of some other embodiments of the motor starting method disclosed herein.

[0036] Figure 9 This is a schematic diagram of the structure of some embodiments of the controller disclosed herein.

[0037] Figure 10 This is a schematic diagram of the structure of some other embodiments of the controller disclosed herein. Detailed Implementation

[0038] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0039] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0040] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0041] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0042] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0044] The inventors discovered through research that the related sensorless control technology has the following significant technical problems that urgently need to be solved under zero speed and ultra-low speed conditions: 1. The three-stage startup scheme of related technologies has inherent defects.

[0045] The industry's current common approach is a three-step starting method: rotor pre-positioning → open-loop forced drag → switching to closed-loop. This approach has the following drawbacks: First, the open-loop starting stage does not rely on the actual rotor position information, requires a large starting current, and is prone to motor step loss or even reverse rotation due to load disturbances or parameter deviations, thus limiting the success rate of starting; Second, the starting torque is small, starting under load is prone to failure, and the multiple starting steps result in a long starting time.

[0046] 2. Start-up, reversal, and jitter issues related to related technologies.

[0047] If the initial rotor position estimation is too far off during compressor startup without a position sensor, the motor may reverse at startup, causing abnormal noise or vibration in the user, which seriously affects the user experience and equipment reliability.

[0048] The inventors also discovered through research that this disclosure aims to solve the following problems existing in the related technology of air conditioner compressor motor starting control: 1. The related technology compressor cannot achieve closed-loop start-up under pure zero-speed conditions, relying on the open-loop drive stage, resulting in an incomplete start-up process.

[0049] 2. The transition from open-loop to closed-loop technology is subject to shocks and speed fluctuations, resulting in insufficient startup success rate and robustness.

[0050] 3. The initial positioning accuracy of related technologies is limited, and reversal or jitter may occur during startup, affecting the user experience.

[0051] 4. The relevant technologies are highly dependent on motor parameters, and the observation accuracy decreases under operating conditions such as temperature changes.

[0052] 5. The filtering process in related technologies suffers from signal delay and attenuation, affecting the real-time performance and accuracy of position observation.

[0053] 6. The segmented switching strategy of related technologies is complex, and the control parameters are difficult to tune.

[0054] In view of at least one of the above-mentioned technical problems, this disclosure provides a motor and its starting method and system, a controller, a compressor, and electrical equipment. This disclosure provides a compressor control method capable of directly achieving closed-loop starting under zero-speed conditions, without an open-loop transition stage, and exhibiting good parameter robustness and operating condition adaptability. This disclosure realizes a technological evolution from sensorless observer-based open-loop forced control, zero-speed closed-loop control, to stable zero-speed torque maintenance.

[0055] The present disclosure will now be described through specific embodiments.

[0056] Figure 1 This is a schematic diagram of some embodiments of the motor starting method disclosed herein. Figure 1 The embodiments may be executed by the motor starting system, controller, compressor, fan, or electrical equipment of this disclosure. For example... Figure 1 As shown, Figure 1 The method of the embodiment may include at least one of steps 11 to 14.

[0057] In step 11, during the zero-speed start-up phase of the motor, a square wave voltage signal of a predetermined frequency is injected into the motor to drive the motor to rotate.

[0058] In some embodiments of this disclosure, the motor may be a compressor motor, a fan motor, or a motor for other devices.

[0059] In some embodiments of this disclosure, the compressor motor can be a compressor motor for electrical appliances such as air conditioners and refrigerators.

[0060] In some embodiments of this disclosure, the fan motor can be a fan motor for electrical appliances such as air conditioners and refrigerators.

[0061] In some embodiments of this disclosure, the predetermined frequency can be much higher than the normal rotation frequency of the motor.

[0062] In some embodiments of this disclosure, the square wave voltage signal can be a square wave voltage signal with alternating positive and negative values, and the amplitude of the square wave voltage signal can be less than a predetermined amplitude.

[0063] Figure 2 This is a schematic diagram of the high-frequency square wave injection signal waveform in some embodiments of this disclosure. For example... Figure 2 As shown, in each carrier cycle (loop), the controller injects a positive voltage V_h and a negative voltage -V_h into the motor. Figure 2 The implementation example involves signal injection: the controller injects a high-frequency square wave voltage signal with alternating positive and negative values ​​into the motor. This signal has a very high frequency (far higher than the motor's normal operating frequency) and a small amplitude, which will not actually make the motor rotate, but will generate a weak current change in the windings. Due to different rotor positions, the shape of this current change will also be different.

[0064] In some embodiments of this disclosure, the injection frequency of the square wave voltage signal can be 5kHz, and the duty cycle can be 50%.

[0065] In the zero-speed start-up phase, the embodiments of this disclosure inject a pulsed high-frequency square wave voltage signal of a set frequency into the dq rotating coordinate system of the motor. Unlike the sinusoidal wave injection method in related technologies, the embodiments of this disclosure adopt a high-frequency square wave injection strategy, which has the advantages of extracting high-frequency response current without the need for filters, low algorithm implementation complexity, and applicability to surface-mounted permanent magnet synchronous motors without significant salient pole effects.

[0066] In step 12, the difference between the current value of the motor at the current moment and the current value at the previous moment is calculated to obtain the response current.

[0067] In some embodiments of this disclosure, step 12 may include: sampling and subtraction.

[0068] In some embodiments of this disclosure, step 12 may include: the controller sampling the three-phase current in each PWM cycle, subtracting the current sampled value from the sampled value one switching cycle ago to obtain the high-frequency output signal Δi. The difference operation in the above embodiments of this disclosure cancels out the fundamental frequency component, retaining only the high-frequency response component carrying rotor position information.

[0069] The injected voltage waveform of the above embodiments of this disclosure is a square wave with alternating positive and negative values ​​and a fixed frequency. Furthermore, during the injection period, a traditional bandpass filter is not used to extract the response current; instead, a delayed difference method is used.

[0070] In step 13, the first rotor position angle of the motor is determined based on the response current.

[0071] In some embodiments of this disclosure, step 13 may include at least one of steps 131 to 132.

[0072] In step 131, the response current is demodulated to obtain the position deviation.

[0073] In some embodiments of this disclosure, step 131 may include: extracting the q-axis component and synchronous demodulating.

[0074] In some embodiments of this disclosure, step 131 may include: extracting the q-axis high-frequency response current Δiqh from the high-frequency output signal Δi, and then multiplying it by a demodulation symbol sequence that is in phase and frequency with the injected square wave (multiply by +1 when injecting positive voltage, and multiply by -1 when injecting negative voltage), and rectifying the high-frequency AC signal into a DC signal representing the position error.

[0075] In step 132, the position deviation is processed by a phase-locked loop to determine the first rotor position angle of the motor.

[0076] In some embodiments of this disclosure, step 132 may include: phase-locked loop tracking.

[0077] In some embodiments of this disclosure, step 132 may include: sending the position error signal into a PLL (Phase-Locked Loop), where the PI module (Proportional-Integral Module) regulator automatically adjusts the estimated rotational speed and estimated angle according to the magnitude of the error until the error is zero. When the error is zero, the PLL outputs the actual rotor position angle.

[0078] The pure delay filtering described in the above embodiments of this disclosure performs subtraction within one switching cycle, automatically canceling the fundamental component, without needing to deliberately change the execution frequency of the PI module.

[0079] The embodiments of this disclosure can use high-frequency square wave injection and pure delay filter extraction techniques, and can process the position deviation through a phase-locked loop to determine the first rotor position angle of the motor. The rotor position estimation accuracy and delay of the embodiments of this disclosure are high, and smooth start-up can be achieved from zero speed, effectively avoiding reverse rotation and jitter, and significantly improving the user experience.

[0080] Figure 3 This is a schematic diagram illustrating the processing principle of high-frequency response current by a pure delay filter in some embodiments of this disclosure. For example... Figure 3 As shown, Figure 1 Steps 12 and 13 of the embodiment may include: the controller performs two operations on the sampled current: the first step is "subtraction" - the current value at the current moment is subtracted from the current value at the previous moment; the second step is "demodulation" - the high-frequency signal is converted into a DC signal and sent to the phase-locked loop for tracking to obtain the first rotor position angle of the motor.

[0081] The embodiments of this disclosure employ first-order difference, i.e., pure delay filtering (the difference between two sampling points is directly calculated). Therefore, the high-frequency response current extraction and processing method of the embodiments of this disclosure has a simpler structure and less computational load.

[0082] In step 14, in the next control cycle, the motor is subjected to closed-loop control of current loop and speed loop using the first rotor position angle.

[0083] The embodiments described above utilize high-frequency square wave injection and pure delay filter extraction techniques to determine the rotor position angle. These embodiments offer high rotor position estimation accuracy and low delay, enabling smooth startup from zero speed, effectively avoiding reverse rotation and jitter, and significantly improving the user experience.

[0084] The embodiments disclosed above can directly enter the closed-loop start-up state from the completely stationary state of the motor of a device such as a compressor or fan, completely eliminating the open-loop forced drag stage in the three-stage start-up of related technologies, avoiding the impact and speed fluctuations caused by the transition from open-loop to closed-loop, and significantly improving the start-up success rate.

[0085] In some embodiments of this disclosure, the motor starting method may further include: during a first operating phase of the motor, receiving feedback of the rotor position angle from the previous control cycle, wherein the motor speed is greater than 0 during the first operating phase; performing the step of injecting a square wave voltage signal of a predetermined frequency into the motor, subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; obtaining the first rotor position angle of the motor based on the response current, and performing closed-loop control of the motor in the next control cycle using the first rotor position angle for current loop and speed loop, i.e., repeating steps 11 to 14.

[0086] The embodiments described above enable closed-loop drive during low-speed operation. These embodiments can operate entirely under closed-loop control, with current optimally allocated according to actual load requirements. Compared to open-loop high-current forced-drive solutions in related technologies, these embodiments effectively reduce the starting current amplitude, achieving energy savings.

[0087] In some embodiments of this disclosure, the first operating phase can be a low-speed operating phase, i.e., a closed-loop drive and real-time tracking phase. The goal of this phase is for the motor to accelerate slowly from zero, and for the position to be accurately tracked at every instant during the low-speed operation without being lost.

[0088] During the low-speed operation phase, this disclosure continues to comply with Figure 3 The implementation example uses a "difference + demodulation" method: during motor speed-up, Figure 3 The processing flow of the embodiment is repeated in each control cycle—sampling the current, extracting the high-frequency signal by subtraction, demodulating to obtain the position deviation, and outputting the real-time angle through the phase-locked loop. Because the pure delay filtering in the above embodiment of this disclosure only requires subtracting the sampled values ​​at two moments, the computational load is very small, so each control cycle can independently output position information without relying on prediction to fill in the gaps.

[0089] In some embodiments of this disclosure, step 14, which involves using the first rotor position angle to perform closed-loop control of the motor in both current and speed loops, may include at least one of steps 141 to 143.

[0090] In step 141, the drive current and drive voltage of the motor are calculated based on the first rotor position angle, and the motor is driven to rotate.

[0091] In step 142, the difference between the current value of the motor at the current moment and the current value at the previous moment is calculated to obtain a new response current.

[0092] In step 143, a new first rotor position angle is determined based on the response current.

[0093] The embodiments of this disclosure can construct a closed-loop control system using the extracted rotor position information. The position angle information extracted in the embodiments of this disclosure, after being processed by a phase-locked loop or a Luneberg observer, can directly participate in the closed-loop control calculations of the current loop and speed loop. The controller in the embodiments of this disclosure can calculate the corresponding dq-axis voltage command based on the real-time position information, generate a drive signal via SVPWM (Space Vector Pulse Width Modulation), and control the inverter to drive the motor. Therefore, the embodiments of this disclosure can achieve complete closed-loop control from zero speed.

[0094] Figure 4 This is a schematic diagram of a closed-loop control method and system for a permanent magnet synchronous motor used in an air conditioning compressor, as described in some embodiments of this disclosure. Figure 4 As shown, in the above embodiments of this disclosure, zero speed means closed loop: after obtaining the initial rotor position, the controller immediately performs a Park change, and from the next control cycle, it enters a complete current loop and speed loop closed loop control, and the motor has been "locked" in position at zero speed.

[0095] In some embodiments of this disclosure, such as Figure 4 This disclosure provides a specific method for using the first rotor position angle θ to perform closed-loop control of the motor in both the current loop and the speed loop. Figure 4 middle, Given the specified rotational speed; To differentiate the position estimation result θ, the response speed is obtained, thereby realizing closed-loop control of the speed loop; This is the q-axis command current; This is the q-axis response current; This is the commanded current for the d-axis; This is the d-axis response current; , These are the d-axis and q-axis voltages, respectively. , They are respectively , Shaft voltage; , and The current is divided into phases a, b, and c. , They are respectively , shaft current; This is the stator resistance.

[0096] Figure 5 This is a structural block diagram of the air conditioning compressor zero-speed closed-loop start control method and system in some embodiments of this disclosure. Figure 4 and Figure 5As shown, the zero-speed closed-loop start control method for air conditioning compressor disclosed herein (e.g., step 141) may include at least one of steps 1 to 8.

[0097] Step 1: The position observer (including at least one of the two methods, high-frequency injection and back EMF) collects the current value of the motor; based on the collected current value of the motor, the speed or position is estimated to determine the rotor position angle θ.

[0098] In some embodiments of this disclosure, such as Figure 5 As shown, step 1 may include: performing current sampling and transformation: the current sensor collects the three-phase current in real time, and after coordinate transformation, it is sent to the position observer. At this time, the transformed angle is not accurate and needs to be corrected later.

[0099] In some embodiments of this disclosure, step 1 may include Figure 1 At least one of steps 12 to 13 in the embodiment.

[0100] In some embodiments of this disclosure, step 1 may include at least one of steps 142 to 143.

[0101] Step 2: Feed back the rotor position angle θ to the speed loop PI module (proportional-integral module).

[0102] In some embodiments of this disclosure, such as Figure 4 As shown, step 2 may include: differentiating the rotor position angle θ to obtain the response speed. , will respond to rotation speed Feedback is sent to the speed loop PI module; the speed loop PI module adjusts the response speed accordingly. and given command speed Determine the q-axis command current .

[0103] Step 3: Feed back the rotor position angle θ to the coordinate transformation module, and the coordinate transformation module correctly calculates the current and voltage based on this angle.

[0104] In some embodiments of this disclosure, steps 2 and 3 may include: constructing a closed-loop control system using the extracted rotor position information, wherein the extracted position angle information is processed by a phase-locked loop or a Romberg observer and then directly participates in the closed-loop control calculation of the current loop and the speed loop.

[0105] In some embodiments of this disclosure, such as Figure 4 and Figure 5 As shown, the coordinate transformation module may include at least one of the Park transformation module, the inverse Park transformation module, and the Clark transformation module.

[0106] In some embodiments of this disclosure, such as Figure 4 and Figure 5 As shown, step 3 may include: feeding back the rotor position angle θ to the coordinate transformation module, which then correctly calculates the current and voltage based on this angle.

[0107] In some embodiments of this disclosure, such as Figure 4 and Figure 5 As shown, step 3 may include: feeding back the rotor position angle θ to the Park conversion module, the Park inverse conversion module, and the Clark conversion module; the Clark conversion module converts the a, b, and c phase currents output by the motor... , and Convert to , shaft current , The Park transformation module, based on the feedback rotor position angle θ, will... , shaft current , Converted to d-axis response current and q-axis response current .

[0108] Step 4: The coordinate transformation module feeds back the response current to the current loop PI module of the d-axis and q-axis.

[0109] In some embodiments of this disclosure, such as Figure 4 and Figure 5 As shown, step 4 may include: the Park transformation module converting the d-axis response current... and q-axis response current The current loop PI modules are fed back to the d-axis and q-axis respectively; the d-axis current loop PI module responds to the d-axis current. and d-axis command current Determine the d-axis voltage The q-axis current loop PI module is based on the q-axis response current. and q-axis command current Determine the q-axis voltage .

[0110] Step 5: The PI modules for the d-axis and q-axis current loops output the d-axis and q-axis voltages, respectively. , To the Park inverse transform module.

[0111] Step 6, the Park inverse transformer module converts the d-axis and q-axis voltages , Convert to , shaft voltage , .

[0112] Step 7, the SVPWM (Space Vector Modulation) module according to , shaft voltage , Generate the drive waveform to the inverter.

[0113] In some embodiments of this disclosure, such as Figure 4 and Figure 5 As shown, the inverter can be an IPM inverter or an IGBT voltage source inverter.

[0114] Step 8: The inverter drives the motor (PMSM) to rotate; then steps 1 through 8 are repeated.

[0115] In the embodiments described above, this disclosure Figure 3 The real-time angle calculated in the embodiment is fed back to Figure 4 or Figure 5 The coordinate transformation module in this embodiment correctly calculates the current and voltage based on this angle. The SVPWM (Space Vector Modulation) module generates a drive waveform, and the inverter drives the motor to rotate. Thus, the above embodiment of this disclosure constitutes a complete closed-loop circuit—the position observer outputs the angle, the angle participates in the coordinate transformation, the transformation result affects the voltage output, the voltage affects the current, and the current is then used by the observer to update the angle.

[0116] The controller in the above embodiments of this disclosure can calculate the corresponding dq axis voltage command based on real-time position information, generate a drive signal via SVPWM (Space Vector Pulse Width Modulation), and control the inverter to drive the motor. Therefore, the above embodiments of this disclosure can achieve complete closed-loop control from zero speed.

[0117] Figure 6 This is a schematic diagram of some other embodiments of the motor starting method disclosed herein. Figure 6 This is an overall flowchart of the control method in some embodiments of this disclosure. Figure 6 The embodiments may be performed by the motor starting system of this disclosure, the controller of this disclosure, the compressor of this disclosure, the fan of this disclosure, or the electrical equipment of this disclosure.

[0118] In some embodiments of this disclosure, the motor starting method may include four stages: Phase 1: Pre-start preparations – determining the initial rotor position. Phase 1 may include... Figures 1 to 3 Method steps of any embodiment, Figure 6 Steps 60 to 62 of the embodiment.

[0119] Phase Two: Low-Speed ​​Operation – Closed-Loop Driving and Real-Time Tracking. Phase Two may include… Figure 6 At least one step in steps 63 to 65 of the embodiment, Figure 7 At least one step in steps 71 to 72 of the embodiment, Figures 2 to 5 Method steps of any embodiment.

[0120] Phase 3: Smooth observer switching. Phase 3 may include... Figure 6 At least one step in steps 63 to 68 of the embodiment, Figures 2 to 5 and Figure 7 The method steps of any of the embodiments.

[0121] Phase Four: Steady-State Operation in the Full-Speed ​​Domain – Parameter Adaptation. Phase Four may include... Figure 6 Step 68 of the embodiment Figure 7 Step 78 of the embodiment. Stage four can correspond to Figure 8 Examples are presented throughout the entire process.

[0122] In some embodiments of this disclosure, such as Figure 6 As shown, Figure 6 The method of the embodiment may include at least one of steps 60 to 68.

[0123] In step 60, during the initial stage, the compressor is in a stationary state.

[0124] In step 61, a high-frequency square wave voltage is injected to extract the initial rotor position θ_int.

[0125] In some embodiments of this disclosure, step 61 may include: injecting a square wave voltage signal of a predetermined frequency into the motor; subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; and determining the first rotor position angle of the motor based on the response current. That is, step 61 may include... Figure 1 At least one of steps 11 to 13 in the embodiment.

[0126] In step 62, the coordinate transformation is initialized, and the system immediately enters the closed-loop control state.

[0127] In some embodiments of this disclosure, step 61 may include: Figure 1 Step 14 of the embodiment, namely step 61, may include: in the next control cycle, using the first rotor position angle to perform closed-loop control of the motor in both current loop and speed loop.

[0128] In some embodiments of this disclosure, steps 60 to 62 (stage one) may include: outputting the initial rotor position after the phase-locked loop converges. The controller immediately initializes the coordinate transformation module with this position, and from the next control cycle, the current loop and speed loop are fully closed. At this time, although the motor is still stationary, the rotor has been positioned and torque can be precisely applied, ready for a smooth start at any time. This completes the process. Figure 4 The example describes the transition from the start to immediately entering the closed-loop control state.

[0129] In step 63, closed-loop drive operation is performed, and the current rotor position angle θ_est and the current rotor speed are estimated in real time. _est.

[0130] In step 64, the motor speed (current rotor speed) is determined. If the motor speed is less than the predetermined threshold, proceed to step 65; otherwise, if the motor speed is not less than the predetermined threshold, proceed to step 66.

[0131] In some embodiments of this disclosure, such as Figure 6 As shown, the predetermined threshold can be 200 rpm.

[0132] In step 65, when the motor speed is less than the predetermined threshold, low-speed adaptive modulation is performed to maintain high-frequency injection.

[0133] In some embodiments of this disclosure, steps 63 to 65 (stage two) may include: after entering the closed loop, performing closed-loop drag operation, and then determining whether the rotational speed is lower than a threshold. If so, continuing high-frequency injection and adaptive adjustment until the rotational speed gradually climbs to near the threshold.

[0134] The objective of the above-described embodiments of this disclosure in the second stage of closed-loop dragging and real-time tracking is to control the motor to accelerate slowly from zero, and the position at every instant must be accurately tracked and not lost.

[0135] In some embodiments of this disclosure, steps 63 to 65 (phase two) may include: according to Figure 3 The implementation example continuously performs "differential analysis + demodulation": during motor speed-up, Figure 3 The processing flow is repeated in each control cycle—sampling the current, extracting the high-frequency signal by subtraction, demodulating to obtain the position deviation, and outputting the real-time angle via the phase-locked loop. Because the pure delay filtering in the above embodiments of this disclosure only requires subtracting the sampled values ​​at two moments, the computational load is very small, so each control cycle can independently output position information without relying on prediction to fill in the gaps.

[0136] In the embodiments described above, when the rotational speed is less than a predetermined value, the rotor position angle can be determined using a high-frequency injection method. The pure delay filtering method of this disclosure only requires the difference between the sampled values ​​at two moments, resulting in a very small computational load. Therefore, in the embodiments described above, each control cycle can independently output position information without relying on prediction to fill in the gaps.

[0137] In some embodiments of this disclosure, steps 63 to 65 (stage two) may further include: according to Figure 4 or Figure 5 Perform closed-loop control: Figure 3 The calculated real-time angle is fed back to Figure 4 or Figure 5 The coordinate transformation module in this embodiment calculates the current and voltage correctly based on the angle. The SVPWM (Space Vector Modulation) module generates a drive waveform, and the inverter drives the motor to rotate. This forms a complete closed-loop circuit: the position observer outputs the angle, the angle participates in the coordinate transformation, the transformation result affects the voltage output, the voltage affects the current, and the current is then used by the observer to update the angle. In the above embodiment of this disclosure, it self-corrects every microsecond to ensure that position tracking is not lost in the low-speed range.

[0138] In some embodiments of this disclosure, step 65 may include: when the motor speed is less than the predetermined threshold, subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; determining the first rotor position angle of the motor based on the response current; and in the next control cycle, performing closed-loop control of the motor using the first rotor position angle for both current loop and speed loop. That is, executing... Figure 1 At least one of steps 12 to 13 in the embodiment.

[0139] In step 66, if the motor speed is not less than the predetermined threshold, the back EMF observer is activated to perform weighted smooth switching.

[0140] In some embodiments of this disclosure, step 66 may include at least one of steps 661 to 664.

[0141] In step 661, if the motor speed is not less than the predetermined threshold, the difference between the current value of the motor at the current moment and the current value at the previous moment is calculated to obtain the response current.

[0142] In step 662, the first rotor position angle of the motor is determined based on the response current.

[0143] In step 663, the back EMF observer is activated, and the back EMF observer is used to determine the second rotor position angle of the motor.

[0144] In step 664, the third rotor position angle is determined based on the first rotor position angle and the second rotor position angle.

[0145] In some embodiments of this disclosure, step 664 may include: determining a first angle value based on the product of the first rotor position angle and the first weight, wherein the first weight is greater than or equal to 0 and less than or equal to 1; determining a second angle value based on the product of the second rotor position angle and the second weight, wherein the sum of the first weight and the second weight is 1; and determining a third rotor position angle based on the first angle value and the second angle value.

[0146] In the transition phase of the embodiments described above, the final third rotor position angle can be accurately determined based on the observation results of two observers (high-frequency injection method and back EMF method) and their respective weights. Therefore, the transition process in the embodiments described above is slow and gradual, with no sudden changes in current and torque, and the user is completely unaware of the switching.

[0147] In step 665, in the next control cycle, the motor is subjected to closed-loop control of the current loop and speed loop using the third rotor position angle.

[0148] In the transition phase described in the embodiments of this disclosure, two observers (high-frequency injection method and back EMF method) can be operated simultaneously. The transition process in the embodiments of this disclosure is slow and gradual, with no sudden changes in current and torque, so that the user cannot perceive the switch at all.

[0149] In some embodiments of this disclosure, the motor starting method may further include: during the first running stage of the motor, controlling the motor speed to gradually increase and controlling the first weight to gradually decrease from 1 to 0; determining whether the first weight is 0; and stopping the injection of a square wave voltage signal of a predetermined frequency into the motor when the first weight is 0.

[0150] In the transition phase described in the embodiments of this disclosure, two observers (high-frequency injection method and back EMF method) can be operated simultaneously. The transition process in the embodiments of this disclosure is slow and gradual, with no sudden changes in current and torque, so that the user cannot perceive the switch at all.

[0151] The algorithm of the above embodiments disclosed has good noise and loss characteristics: the high-frequency square wave injection is only used for a short time in the zero low speed stage and is immediately turned off after the observer switches, thereby avoiding the additional loss and high-frequency noise caused by full-time injection.

[0152] To address the issue of additional losses in the high-frequency injection method at medium and high speeds, the embodiments of this disclosure include an observer switching control logic: when the estimated rotational speed reaches a preset threshold, the controller automatically switches the position observer from the high-frequency injection method to a model method based on back electromotive force, ensuring position observation accuracy across the entire rotational speed range. The switching process in the embodiments of this disclosure employs a weighted smooth transition strategy to avoid abrupt changes in the observer's position.

[0153] The embodiments disclosed above can realize a seamless switching strategy for observers across the entire speed range.

[0154] In step 67, high-frequency injection is turned off, and the pure back EMF method operates at high speed.

[0155] In step 68, the motor operates normally.

[0156] The embodiments of this disclosure utilize closed-loop control throughout the entire process of a compressor or fan motor starting from rest to rotation (i.e., the position observer output always participates in the current / speed loop feedback), without any independent open-loop forced drive step. The motor startup process of the compressor or fan in the embodiments of this disclosure exhibits a stable current waveform and no large current surges.

[0157] The embodiments of this disclosure provide a zero-speed closed-loop start-up control method for sensorless motors in devices such as air conditioner compressors or fans, enabling closed-loop control to be established from a completely stationary motor state. The embodiments of this disclosure provide a complete motor start-up process: a complete start-up strategy from standstill → initial positioning → closed-loop establishment → closed-loop dragging → smooth switching → high-speed operation. The embodiments of this disclosure eliminate the open-loop stage: the embodiments of this disclosure explicitly abandon the three-stage open-loop start-up mode of related technologies, and the embodiments of this disclosure do not require a "forced open-loop dragging" stage throughout the entire process.

[0158] Figure 7 This is a schematic diagram of some embodiments of the motor starting method disclosed herein. Figure 7 This is a flowchart of the observer switching logic in some embodiments of this disclosure. This disclosure... Figure 7 Implementation examples Figure 6 The observer switching process in steps 66 and 67 of the embodiment is further explained. Figure 7 The embodiments may be executed by the motor starting system, controller, compressor, fan, or electrical equipment of this disclosure. For example... Figure 7 As shown, Figure 7 The method of the embodiment may include at least one of steps 71 to 78.

[0159] In step 71, a high-frequency injection method is used during closed-loop operation.

[0160] In step 72, the estimated motor speed (current rotor speed) is monitored. _est).

[0161] In step 73, the motor speed (current rotor speed) is determined. Check if the motor speed (_est) is greater than or equal to a predetermined threshold. If the motor speed is greater than or equal to the predetermined threshold, proceed to step 74; otherwise, if the motor speed is less than the predetermined threshold, proceed to step 71.

[0162] In some embodiments of this disclosure, such as Figure 7 As shown, the predetermined threshold can be 250 rpm.

[0163] In some embodiments of this disclosure, a predetermined threshold (e.g.) Figure 6 or Figure 7 The predetermined threshold value in the embodiment can range from 200 rpm to 300 rpm. The reason for setting the lower limit (200 rpm) is that below this speed, the back EMF amplitude of the permanent magnet synchronous motor is too low, resulting in a poor signal-to-noise ratio, and back EMF observers such as sliding mode / ESO cannot converge, necessitating reliance on the high-frequency injection method. The reason for setting the upper limit (300 rpm) is that above this speed, the back EMF signal is strong enough to support stable operation of the pure model method; and continuing to use high-frequency injection at this point would introduce significant additional losses and audible noise, so it should be shut down as soon as possible.

[0164] In other embodiments of this disclosure, in practical engineering adaptations, the predetermined threshold can be adjusted within a wider range (e.g., 150 rpm to 500 rpm) depending on the number of pole pairs and load characteristics of different compressors. For example, for high-inertia or low-temperature heating compressors, the predetermined threshold can be increased to 300-350 rpm. These types of motors have heavy loads and require a sufficiently large back electromotive force to withstand disturbances and avoid loss of synchronization during switching. For small or low-pole-pole-pole compressors, the predetermined threshold can be decreased to 150-180 rpm. These types of motors have higher back electromotive force constants, and the signal is clear enough at low speeds, allowing for earlier switching to the model method to reduce high-frequency noise.

[0165] In step 74, the back electromotive force observer (sliding mode observer or ESO observer) is activated.

[0166] In step 75, the second weight α is controlled to gradually increase from 0 to 1, where the total estimated angle θ = α × θ_EMF + (1-α) × θ_HFI, θ_HFI represents the rotor position angle estimated based on the high-frequency square wave injection method, θ_EMF represents the rotor position angle estimated based on the motor back EMF model, and α represents the weighted transition factor dynamically adjusted by the controller.

[0167] In some embodiments of this disclosure, the transition time for smooth weighted switching (high-frequency injection → back EMF) is typically 0.2 to 1 second, rather than a direct jump.

[0168] The embodiments disclosed above, by recording the angle or current waveform at the moment of switching, found that there was no obvious jump or impact in the switching from high-frequency injection to back electromotive force.

[0169] In step 76, it is determined whether the second weight α is equal to 1. If the first weight is equal to 1, step 77 is executed; otherwise, if the first weight is less than 1, step 75 is executed.

[0170] In step 77, high-frequency injection is turned off, and the back EMF method observer is used exclusively.

[0171] In step 78, the motor runs at high speed.

[0172] In the embodiments described above, the controller simultaneously operates two observers (high-frequency injection and back EMF), but initially, the high-frequency injection angle accounts for 100%, while the back EMF angle accounts for 0%. Over time, in these embodiments, the weight of the high-frequency injection gradually decreases, while the weight of the back EMF gradually increases until the back EMF accounts for 100%. This process is slow and gradual, with no sudden changes in current or torque, and the user is completely unaware of the switching. After the switching is complete in these embodiments, the controller shuts off the high-frequency injection signal and continues driving entirely based on the back EMF observer. Figure 6 The embodiment also proceeds to step 67 simultaneously – “Turn off high-frequency injection and run at high speed using the pure back EMF method”.

[0173] Figure 8 This is a schematic diagram of some other embodiments of the motor starting method disclosed herein. Figure 8 The following is an algorithm flowchart of the parameter adaptation module in some embodiments of this disclosure. Figure 8 The embodiments may be executed by the motor starting system, controller, compressor, fan, or electrical equipment of this disclosure. For example... Figure 8 As shown, the motor starting method disclosed herein may include, in addition to, Figures 1 to 7 In addition to the method steps of at least one embodiment, the embodiments may also include at least one of steps 81 to 85.

[0174] In step 81, real-time data of the motor is acquired, wherein the real-time data includes real-time current, voltage and speed data.

[0175] In some embodiments of this disclosure, step 81 may include: real-time sampling.

[0176] In some embodiments of this disclosure, step 81 may include: the controller acquiring the current d-axis current, q-axis current, d-axis voltage, q-axis voltage and rotor electric angular velocity in each PWM cycle, and recording the operating state of the motor at this moment.

[0177] In step 82, the current parameters of the motor are determined based on the real-time data, wherein the parameters may include at least one of resistance and inductance.

[0178] In some embodiments of this disclosure, step 82 may include: determining the current parameters of the motor using recursive least squares (PLS) based on the real-time data.

[0179] In some embodiments of this disclosure, the resistor may be a stator winding resistor R.

[0180] In some embodiments of this disclosure, the inductor may include at least one of the d-axis inductance Ld and the q-axis inductance Lq.

[0181] In some embodiments of this disclosure, step 82 may include: determining the current parameters of the motor using the RSL online identification formula, wherein the core logic of RLS is: each control cycle derives a set of the latest resistance and inductance values ​​based on the current voltage and current data.

[0182] In some embodiments of this disclosure, step 82 may include: RLS online identification.

[0183] In some embodiments of this disclosure, step 82 may include: substituting the data collected in the first step into the above RLS recursive formula to calculate a set of latest resistance and inductance values. RLS is not calculated once at a specific moment, but rather every control cycle, continuously outputting the latest parameter estimates.

[0184] In some embodiments of this disclosure, the RSL online identification formula may include a gain matrix as in formula (1), a parameter update formula as in formula (2), and a covariance update formula as in formula (3).

[0185] K(k) = (1)

[0186] RS(k) = RS(k-1) + K(k) [ (k)- RS(k-1)] (2) = [1-K(k) ] (3) In formulas (1) to (3): It is the d-axis current. λ is the d-axis voltage command, λ is the forgetting factor (usually 0.95~0.99), and P is the covariance matrix (representing the confidence level of the current identification result).

[0187] In some embodiments of this disclosure, step 82 may include: performing the recursion of formulas (1) to (3) once per PWM cycle, and outputting the latest value in real time. , .

[0188] In step 83, the parameter change value of the motor is determined based on the current parameters of the motor and the motor parameters currently used by the back EMF observer.

[0189] In step 84, it is determined whether the parameter change value is greater than a predetermined value. If the parameter change value is greater than the predetermined value, step 85 is executed; if the parameter change value is not greater than the predetermined value, step 81 is executed.

[0190] In some embodiments of this disclosure, step 84 may include: the controller comparing the newly calculated parameters (such as the current resistance value) with the old parameters currently being used by the observer, and calculating the percentage deviation. If the deviation is small, it indicates that the parameters have not changed significantly, and the current gain of the observer is sufficient. Therefore, the controller directly jumps back to the first box and continues to wait for the next sampling period. The significance of this judgment is to avoid mistaking occasional current fluctuations for parameter changes and to prevent frequent erroneous updates.

[0191] In step 85, if the parameter change value is greater than a predetermined value, the internal parameter table of the observer is updated to correct the parameters of the back EMF observer.

[0192] In some embodiments of this disclosure, step 85 may include at least one of steps 851 and 852.

[0193] In step 851, the observer's internal parameter table is updated.

[0194] In some embodiments of this disclosure, step 851 may include: once the determination deviation exceeds a threshold, the controller immediately performs an update—writing the newly identified resistance and inductance values ​​of the RLS into the variable area in memory specifically storing observer parameters, overwriting the old values. Simultaneously, a flag indicating that the parameters have been updated is set, and the gain is recalculated.

[0195] In step 852, the sliding mode / ESO gain is corrected.

[0196] In some embodiments of this disclosure, step 852 may include: upon detecting the "parameters updated" flag, the controller immediately substitutes the newly written R and L values ​​into the aforementioned gain formula to recalculate the new sliding mode gain, filter cutoff frequency, or ESO bandwidth, and writes this new value into the observer's gain register. From the next PWM cycle onwards, the observer operates according to the new gain coefficients. After correction, the process immediately returns to step one to continue sampling, identification, judgment, and correction, forming a closed loop that continuously monitors the compressor's operating status.

[0197] The above embodiments of this disclosure Figure 8 The process in the embodiment does not start only at a certain stage, but runs continuously from the moment the motor starts running. Figure 8 The example can continuously perform three operations: 1. Real-time monitoring: Continuously collects current current, voltage, and speed data.

[0198] 2. Online learning: Using this real-time data, the current actual resistance and inductance values ​​of the motor can be automatically calculated.

[0199] 3. Comparison and Update: The calculated new parameters are compared with the old parameters to correct the observer parameters. If a parameter change is determined to be excessive, firstly, the new parameters are written into the observer so that it remembers the motor's current state; secondly, the observer's gain is recalculated—for example, as temperature increases, resistance increases, requiring a stronger observer to keep up with the change; as temperature decreases, resistance decreases, requiring a weaker observer to avoid amplifying noise. After correction, monitoring resumes, forming a continuous loop.

[0200] In the embodiments of this disclosure, after the RLS online identification algorithm in the background calculates the new resistance and inductance values, the controller can first determine whether the deviation between these new values ​​and the old values ​​currently in use exceeds a preset threshold. Once the deviation exceeds the threshold, the new parameters are immediately written into the variable area in memory that is specifically used to store the observer parameters, overwriting the old data. At the same time, a "parameters have been updated" flag is set to notify the main program to recalculate the gain coefficient of the observer with this set of new parameters in the next control cycle, so that the observer can adapt to the drift of motor parameters caused by temperature changes in real time.

[0201] The parameters of the above embodiments of this disclosure are highly robust: The technical solutions of the above embodiments of this disclosure include a parameter adaptive module. Compared with certain closed-loop starting schemes in some related technologies that rely entirely on motor parameters, the above embodiments of this disclosure have better versatility and adaptability among different models of compressors.

[0202] To address the drift of electrical parameters such as resistance and inductance caused by internal temperature changes during air conditioner compressor operation, the embodiments of this disclosure include an online parameter identification and adaptive update module in the controller. These embodiments can real-time monitor steady-state operating current and voltage, and use online identification methods such as recursive least squares to correct the observer parameters in real time, thereby ensuring high-precision output from the observer across the entire operating range.

[0203] In some embodiments of this disclosure, the back EMF observer may be a sliding mode observer or an extended state observer.

[0204] In some embodiments of this disclosure, a sliding mode observer (SMO) is used, which "first estimates the back electromotive force (EMF) and then calculates the position." In other embodiments, an extended state observer (ESO) is used, which "treats the back EMF as part of the system, processing the estimation and calculation together in one step." Therefore, the observation steps using ESO in this disclosure are essentially "packaging the back EMF into the total disturbance for estimation," which eliminates a separate back EMF estimation step compared to using SMO, resulting in a simpler algorithm structure.

[0205] In some embodiments of this disclosure, the parameters of the back EMF observer may include at least one of the following: sliding mode observer gain, low-pass filter cutoff frequency, extended state observer gain, and extended state observer bandwidth.

[0206] The embodiments disclosed above can use an extended state observer (ESO) to replace a conventional sliding mode observer. In the back EMF observer in the medium and high speed range, a sensorless control scheme based on an extended state observer can be used to replace a conventional sliding mode observer or a phase-locked loop scheme. By designing an adaptive law for the back EMF observation error that varies with the rotational speed of the observer, higher observation accuracy and stronger system robustness can be obtained.

[0207] The adaptive law design of the above embodiments of this disclosure is essentially to "automatically adjust the sensitivity of the observer with the rotation speed", amplifying the signal at low speed and suppressing noise at high speed, so as to ensure that the position angle can be accurately determined in the entire speed range.

[0208] In some embodiments of this disclosure, for the sliding mode observer, two key coefficients need to be corrected: the sliding mode observer gain K. slide and low-pass filter cutoff frequency .

[0209] In some embodiments of this disclosure, step 85 may include: correcting the sliding mode observer gain according to formula (4).

[0210] =λ (4)

[0211] In formula (4), For the latest sliding mode observer gain, The latest identified stator resistors; For the newly identified inductors, = = λ is the gain coefficient, which can typically be 0.5-1.

[0212] In other embodiments of this disclosure, step 85 may include: correcting the low-pass filter cutoff frequency according to formula (5). .

[0213] = +m (5)

[0214] In formula (5), is the currently estimated electric angular velocity (rad / s); m is the velocity feedforward coefficient.

[0215] In other embodiments of this disclosure, step 85 may include: correcting the ESO bandwidth according to formula (6). .

[0216] =n +y (6)

[0217] In some other embodiments of this disclosure, step 85 may include: correcting the ESO gains β1 and β2 according to formula (7).

[0218] β1=2 β2= (7)

[0219] In some embodiments of this disclosure, step 85 may include: after the RLS calculates the new parameters, the controller substitutes them into formulas (4) to (7) to recalculate the gain and writes the new gain into the observer.

[0220] The embodiments of this disclosure substitute the newly identified R and L into the "sensitivity" calculation formula of the observer to obtain a new set of coefficients.

[0221] Figure 9 This is a schematic diagram illustrating the structure of some embodiments of the controller disclosed herein. For example... Figure 9 As shown, the controller disclosed herein may include at least one of a voltage injection module 91, a current difference module 92, a position determination module 93, and a closed-loop control module 94.

[0222] The voltage injection module 91 is configured to inject a square wave voltage signal of a predetermined frequency into the motor during the zero-speed start-up phase of the motor, thereby driving the motor to rotate.

[0223] In some embodiments of this disclosure, the predetermined frequency may be greater than the normal rotation frequency of the motor, the square wave voltage signal may be a square wave voltage signal with alternating positive and negative values, and the amplitude of the square wave voltage signal may be less than the predetermined amplitude.

[0224] In some embodiments of this disclosure, the voltage injection module 91 can be implemented as a high-frequency square wave voltage injection module.

[0225] In some embodiments of this disclosure, the voltage injection module 91 can be configured to inject a pulsed high-frequency square wave voltage signal of a set frequency into the dq rotating coordinate system of the motor during the zero-speed start-up phase. Unlike the method of injecting sine waves in related technologies, the above embodiments of this disclosure adopt a high-frequency square wave injection strategy, which has the advantages of extracting high-frequency response current without the need for filters, low algorithm implementation complexity, and applicability to surface-mounted permanent magnet synchronous motors without significant salient pole effects.

[0226] In some embodiments of this disclosure, the motor may be a compressor motor, a fan motor, or a motor for other devices.

[0227] In some embodiments of this disclosure, the compressor motor can be a compressor motor for electrical appliances such as air conditioners and refrigerators.

[0228] In some embodiments of this disclosure, the fan motor can be a fan motor for electrical appliances such as air conditioners and refrigerators.

[0229] The current difference module 92 is configured to subtract the current value of the motor at the current moment from the current value at the previous moment to obtain the response current.

[0230] The position determination module 93 is configured to determine the first rotor position angle of the motor based on the response current.

[0231] In some embodiments of this disclosure, the position determination module 93 can be configured to demodulate the response current to obtain a position deviation; and process the position deviation through a phase-locked loop to determine the first rotor position angle of the motor.

[0232] In some embodiments of this disclosure, the current difference module 92 and the position determination module 93 can be implemented as a high-frequency response current signal processing and rotor position extraction module.

[0233] In some embodiments of this disclosure, the high-frequency response current signal processing and rotor position extraction module can be configured to obtain a high-frequency response current component containing rotor position modulation information through current sampling; and to use a signal extraction technique based on a pure delay filter to sample at a frequency twice the injection frequency, and to subtract the measured value delayed by one sampling period from the current real-time measured value to obtain a high-frequency output signal, which is then filtered by a pure delay filter to achieve zero-phase-delay rotor position information extraction.

[0234] The closed-loop control module 94 is configured to perform closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

[0235] In some embodiments of this disclosure, the closed-loop control module 94 can be configured to, in the next control cycle, calculate the drive current and drive voltage of the motor based on the first rotor position angle, and drive the motor to rotate; subtract the current value of the motor at the current moment from the current value at the previous moment to obtain a new response current; and determine a new first rotor position angle based on the response current.

[0236] In some embodiments of this disclosure, the closed-loop control module 94 may be configured as a position closed-loop control module.

[0237] In some embodiments of this disclosure, the closed-loop control module 94 can be configured to construct a closed-loop control system using the extracted rotor position information. The extracted position angle information, after being processed by a phase-locked loop or a Luneberg observer, directly participates in the closed-loop control calculations of the current loop and speed loop. Based on the real-time position information, the corresponding dq-axis voltage command is calculated, and a drive signal is generated via SVPWM (Space Vector Pulse Width Modulation) to control the inverter to drive the motor. Therefore, the above embodiments of this disclosure can achieve a complete closed-loop control state starting from zero speed.

[0238] In some embodiments of this disclosure, the controller may also be configured to receive feedback of the rotor position angle from the previous control cycle during a first operating phase of the motor, wherein the motor speed is greater than 0 during the first operating phase; inject a square wave voltage signal of a predetermined frequency into the motor; subtract the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; obtain a first rotor position angle of the motor based on the response current; and in the next control cycle, perform closed-loop control of the motor using the first rotor position angle for both current loop and speed loop.

[0239] In some embodiments of this disclosure, the controller may also be configured to receive feedback of the rotor position angle from the previous control cycle during a first operating phase of the motor, wherein the motor speed is greater than 0 during the first operating phase; inject a square wave voltage signal of a predetermined frequency into the motor; acquire the motor speed; determine whether the motor speed is less than a predetermined threshold; if the motor speed is less than the predetermined threshold, subtract the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; determine the first rotor position angle of the motor based on the response current; and in the next control cycle, use the first rotor position angle to perform closed-loop control of the motor in both current loop and speed loop.

[0240] In some embodiments of this disclosure, the controller may also be configured to, when the motor speed is not less than the predetermined threshold, subtract the current value of the motor at the current moment from the current value at the previous moment to obtain a response current; determine the first rotor position angle of the motor based on the response current; activate the back EMF observer and use the back EMF observer to determine the second rotor position angle of the motor; determine the third rotor position angle based on the first rotor position angle and the second rotor position angle; and in the next control cycle, use the third rotor position angle to perform closed-loop control of the motor in the current loop and speed loop.

[0241] In some embodiments of this disclosure, when the controller determines a third rotor position angle based on the first rotor position angle and the second rotor position angle, it can be configured to determine a first angle value based on the product of the first rotor position angle and a first weight, wherein the first weight is greater than or equal to 0 and less than or equal to 1; determine a second angle value based on the product of the second rotor position angle and the second weight, wherein the sum of the first weight and the second weight is 1; and determine a third rotor position angle based on the first angle value and the second angle value.

[0242] In some embodiments of this disclosure, the controller may also be configured to, during the first operating phase of the motor, control the motor speed to gradually increase and control the first weight to gradually decrease from 1 to 0; determine whether the first weight is 0; and, if the first weight is 0, stop injecting a square wave voltage signal of a predetermined frequency into the motor.

[0243] In some embodiments of this disclosure, the controller may also be configured to acquire real-time data of the motor, wherein the real-time data includes real-time current, voltage, and speed data; determine current parameters of the motor based on the real-time data, wherein the parameters include at least one of resistance and inductance; determine parameter change values ​​of the motor based on the current parameters of the motor and the motor parameters currently used by the back EMF observer; determine whether the parameter change value is greater than a predetermined value; and correct the parameters of the back EMF observer if the parameter change value is greater than the predetermined value.

[0244] In some embodiments of this disclosure, the back EMF observer may be a sliding mode observer or an extended state observer.

[0245] In some embodiments of this disclosure, the parameters of the back EMF observer may include at least one of the following: sliding mode observer gain, low-pass filter cutoff frequency, extended state observer gain, and extended state observer bandwidth.

[0246] Figure 4 and Figure 5 The embodiments also provide schematic diagrams of some embodiments of the controller of this disclosure. For example... Figure 4 and Figure 5 As shown, the controller disclosed herein may also include at least one of the following modules: a position observer, a coordinate transformation module, a Park transformation module, an inverse Park transformation module, a Clark transformation module, a PI module, a space vector modulation module, a parameter adaptive module, and a phase-locked loop.

[0247] In some embodiments of this disclosure, the controller may also be configured to implement any of the embodiments described above (e.g., Figures 1 to 8 The motor starting method described in any embodiment.

[0248] The embodiments disclosed above can achieve full closed-loop control of permanent magnet synchronous motors of devices such as compressors or fans from a stationary state, abandoning the three-stage open-loop start-up mode of related technologies, eliminating the need for an open-loop transition stage throughout the process, and realizing high-precision position closed-loop start-up under zero-speed conditions.

[0249] The embodiments disclosed above are based on high-frequency square wave injection and pure delay filter for position extraction. A high-frequency square wave voltage (instead of a sine wave) is injected, and a pure delay filter is used to extract the high-frequency response current by subtracting the current sampled value from the sampled value one cycle earlier. This achieves zero-phase-delay, attenuation-free rotor position demodulation, significantly improving the accuracy of zero-low-speed observation.

[0250] The embodiments disclosed above employ parameter adaptive online identification. The controller is equipped with a parameter identification module (such as recursive least squares method), which can correct parameters such as motor resistance and inductance in real time. It can automatically adapt to temperature changes and different compressor models, thereby improving system robustness.

[0251] Figure 10 This is a schematic diagram illustrating the structure of other embodiments of the controller disclosed herein. For example... Figure 10 As shown, the controller disclosed herein may include a memory 101 and a processor 102.

[0252] Memory 101 is used to store instructions, and processor 102 is coupled to memory 101. Processor 102 is configured to execute instructions stored in memory 101 to implement the above embodiments (e.g., Figures 1 to 8 The motor starting method involved in any embodiment.

[0253] like Figure 10 As shown, the controller also includes a communication interface 103 for exchanging information with other devices. Additionally, the controller includes a bus 104, through which the processor 102, communication interface 103, and memory 101 communicate with each other.

[0254] Memory 101 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk drive. Memory 101 may also be a memory array. Memory 101 may also be divided into blocks, and the blocks may be combined into virtual volumes according to certain rules.

[0255] Furthermore, processor 102 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present disclosure.

[0256] According to another aspect of this disclosure, a motor starting system is provided, including a controller as described in any of the above embodiments.

[0257] Figure 4 and Figure 5 The embodiments also provide schematic diagrams of some embodiments of the motor starting system of this disclosure. For example... Figure 4 and Figure 5 As shown, the motor starting system disclosed herein may also include at least one of an inverter and a three-phase current acquisition device.

[0258] According to another aspect of this disclosure, a compressor is provided, including a motor and a motor starting system as described in any of the above embodiments.

[0259] According to another aspect of this disclosure, a fan is provided, including a motor and a motor starting system as described in any of the above embodiments.

[0260] According to another aspect of this disclosure, an electrical device is provided, comprising at least one of a compressor as described in any of the above embodiments and a fan as described in any of the above embodiments.

[0261] In some embodiments of this disclosure, the electrical equipment may be an air conditioner, a refrigerator, or other electrical equipment.

[0262] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, it implements the motor starting method as described in any of the above embodiments.

[0263] According to another aspect of this disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions that, when executed by a processor, implement the motor starting method as described in any of the above embodiments.

[0264] The embodiments disclosed above have the following technical effects: 1. The above embodiments of this disclosure achieve true zero-speed closed-loop start-up: The above embodiments of this disclosure can directly enter the closed-loop start-up state from the motor of the compressor, motor and other devices from a completely stationary state, completely eliminating the open-loop forced drag stage in the traditional three-stage start-up, avoiding the impact and speed fluctuations caused by the transition from open loop to closed loop, and significantly improving the start-up success rate.

[0265] 2. The above embodiments of this disclosure reduce the starting current amplitude and achieve energy saving effect: Since the above embodiments of this disclosure operate under closed-loop control throughout the process, the current can be optimally allocated according to the actual load demand. Compared with the open-loop high-current strong drag scheme, the above embodiments of this disclosure can effectively reduce the starting current amplitude and achieve the effect of saving energy.

[0266] 3. The above embodiments of this disclosure improve startup smoothness: The above embodiments of this disclosure improve the accuracy of rotor position estimation and reduce delay by using high-frequency square wave injection and pure delay filter extraction technology. The above embodiments of this disclosure achieve smooth startup from zero speed, effectively avoid reverse rotation and jitter, and significantly improve user experience.

[0267] 4. The parameters of the above embodiments of this disclosure are highly robust: The technical solutions of the above embodiments of this disclosure include a parameter adaptive module. Compared with the specific closed-loop starting schemes in some related technologies that rely entirely on motor parameters, the above embodiments of this disclosure have better versatility and adaptability among different models of compressors.

[0268] 5. The algorithm of the above embodiments of this disclosure has good noise and loss characteristics: The high-frequency square wave injection of the above embodiments of this disclosure is only used for a short time in the zero low speed stage and is immediately turned off after the observer is switched, thereby avoiding the additional loss and high-frequency noise caused by full-time injection.

[0269] 6. The hardware of the above embodiments of this disclosure has good compatibility: The technical solutions of the above embodiments of this disclosure are entirely based on the sensorless FOC hardware architecture, without the need to add any additional sensors, and can be directly applied to the existing air conditioning compressor controller platform, with low modification costs.

[0270] The computer-readable storage medium disclosed herein can be implemented as a non-transitory computer-readable storage medium.

[0271] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0272] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0273] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0274] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0275] The controller, voltage injection module, current difference module, position determination module, closed-loop control module, position observer, coordinate transformation module, Park transformation module, inverse Park transformation module, Clark transformation module, PI module, parameter adaptation module, space vector modulation module, and phase-locked loop described above can be implemented as a general-purpose processor, programmable logic controller, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any suitable combination thereof for performing the functions described herein.

[0276] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments of this disclosure can be implemented in hardware. The hardware can be implemented as a general-purpose processor, programmable logic controller, digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, discrete hardware component or any suitable combination thereof for executing the methods of this disclosure.

[0277] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0278] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing the relevant hardware to implement them. The program can be stored in a non-transitory computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0279] The description in this disclosure is provided for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the disclosure to its forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of this disclosure and to enable those skilled in the art to understand this disclosure and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for starting a motor, comprising: During the zero-speed start-up phase of the motor, a square wave voltage signal of a predetermined frequency is injected into the motor to drive the motor to rotate. The response current is obtained by subtracting the current value of the motor at the current moment from the current value at the previous moment. The first rotor position angle of the motor is determined based on the response current; In the next control cycle, the motor is subjected to closed-loop control of current loop and speed loop using the first rotor position angle.

2. The motor starting method according to claim 1 further includes: During the first operating phase of the motor, the rotor position angle of the previous control cycle is received as feedback, wherein the motor speed is greater than 0 during the first operating phase. The steps include: injecting a square wave voltage signal of a predetermined frequency into the motor; subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; obtaining the first rotor position angle of the motor based on the response current; and performing closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

3. The motor starting method according to claim 1 further includes: During the first operating phase of the motor, the rotor position angle of the previous control cycle is received as feedback, wherein the motor speed is greater than 0 during the first operating phase. A square wave voltage signal of a predetermined frequency is injected into the motor. Obtain the motor speed; Determine whether the motor speed is less than a predetermined threshold; When the motor speed is less than the predetermined threshold, the following steps are performed: subtracting the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; determining the first rotor position angle of the motor based on the response current; and performing closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

4. The motor starting method according to claim 3 further includes: When the motor speed is not less than the predetermined threshold, the difference between the current value of the motor at the current moment and the current value at the previous moment is calculated to obtain the response current. The first rotor position angle of the motor is determined based on the response current; Start the back EMF observer and use the back EMF observer to determine the second rotor position angle of the motor; The third rotor position angle is determined based on the first rotor position angle and the second rotor position angle; In the next control cycle, the motor is controlled in a closed loop using the third rotor position angle for both current and speed loops.

5. The motor starting method according to claim 4, wherein, Determining the third rotor position angle based on the first rotor position angle and the second rotor position angle includes: The first angle value is determined based on the product of the first rotor position angle and the first weight, wherein the first weight is greater than or equal to 0 and less than or equal to 1; The second angle value is determined based on the product of the second rotor position angle and the second weight, wherein the sum of the first weight and the second weight is 1; The third rotor position angle is determined based on the first angle value and the second angle value.

6. The motor starting method according to claim 5 further includes: During the first operating phase of the motor, the motor speed is gradually increased, and the first weight is gradually decreased from 1 to 0. Determine whether the first weight is 0; When the first weight is 0, the injection of a square wave voltage signal of a predetermined frequency into the motor is stopped.

7. The motor starting method according to any one of claims 4 to 6, further comprising: Acquire real-time data of the motor, wherein the real-time data includes real-time current, voltage, and speed data; Based on the real-time data, the current parameters of the motor are determined, wherein the parameters include at least one of resistance and inductance; The parameter changes of the motor are determined based on the current parameters of the motor and the motor parameters currently used by the back EMF observer. Determine whether the change in the parameter is greater than a predetermined value; If the parameter change value is greater than a predetermined value, the parameters of the back EMF observer are corrected.

8. The motor starting method according to claim 7, wherein: The back EMF observer is a sliding mode observer or an extended state observer; The parameters of the back EMF observer include at least one of the following: sliding mode observer gain, low-pass filter cutoff frequency, extended state observer gain, and extended state observer bandwidth.

9. The motor starting method according to any one of claims 1 to 6, wherein, The predetermined frequency is greater than the normal rotation frequency of the motor, the square wave voltage signal is a square wave voltage signal with alternating positive and negative values, and the amplitude of the square wave voltage signal is less than the predetermined amplitude.

10. The motor starting method according to any one of claims 1 to 6, wherein, Determining the first rotor position angle of the motor based on the response current includes: The position deviation is obtained by demodulating the response current; The position deviation is processed by a phase-locked loop to determine the first rotor position angle of the motor.

11. The motor starting method according to any one of claims 1 to 6, wherein, The closed-loop control of the motor using the first rotor position angle for both current and speed loops includes: The driving current and driving voltage of the motor are calculated based on the first rotor position angle, and the motor is driven to rotate. The new response current is obtained by subtracting the current value of the motor at the current moment from the current value at the previous moment. Based on the response current, a new first rotor position angle is determined.

12. The motor starting method according to any one of claims 1 to 6, wherein, The motor is either a compressor motor or a fan motor.

13. A controller, comprising: The voltage injection module is configured to inject a square wave voltage signal of a predetermined frequency into the motor during the zero-speed start-up phase of the motor, thereby driving the motor to rotate. The current difference module is configured to subtract the current value of the motor at the current moment from the current value at the previous moment to obtain the response current; The position determination module is configured to determine the first rotor position angle of the motor based on the response current; The closed-loop control module is configured to perform closed-loop control of the motor in the current loop and speed loop using the first rotor position angle in the next control cycle.

14. A controller, comprising: The memory is configured to store instructions; as well as A processor coupled to the memory, the processor being configured to execute the motor starting method as described in any one of claims 1 to 12 based on instructions stored in the memory.

15. A motor starting system, comprising the controller as described in claim 13 or 14.

16. A compressor, comprising a motor and a motor starting system as claimed in claim 15.

17. An electrical appliance comprising the compressor as claimed in claim 16.

18. A computer-readable storage medium, wherein, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the motor starting method as described in any one of claims 1 to 12.

19. A computer program product comprising a computer program, wherein, When the computer program is executed by the processor, it implements the motor starting method as described in any one of claims 1 to 12.

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