Motor, control method and device thereof, frequency converter, storage medium and program product

Abstract

The application discloses a motor and a control method, device, frequency converter, storage medium and computer program product thereof, and relates to the technical field of motor control. The method comprises the following steps: acquiring a current signal of the motor in the process of starting frequency conversion debugging of the motor; after determining that the current waveform of the motor is unstable and controlling the motor to run at a fallback frequency, determining a corrected PI parameter of the motor according to the current signal of the motor; applying the corrected PI parameter of the motor to a control loop of a control system of the motor, and attempting to control the motor to run at a frequency before the motor runs at the fallback frequency. According to the scheme, the motor is controlled to run at a lower frequency after the three-phase current waveform of the motor is unstable, and then the motor is controlled to run at a higher frequency after the PI parameter is adjusted, so that the debugging time is reduced, the risk of equipment damage is reduced, the debugging efficiency is improved, and the stability of the motor is improved. The frequency converter relates to the manufacturing of power electronic components.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a motor control method, device, motor, frequency converter, storage medium, and computer program product. More particularly, it relates to an adaptive intelligent control method, device, motor, frequency converter, storage medium, and computer program product for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during frequency conversion commissioning and startup. The frequency converter involves the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules. Background Technology

[0002] During the frequency converter commissioning and startup process of motors such as permanent magnet synchronous motors (PMSMs), if the three-phase current waveform of the frequency converter output becomes unstable, it can lead to abnormal motor operation, reduced efficiency, or even equipment damage, affecting motor commissioning efficiency and posing a significant risk of equipment damage. This frequency converter involves the manufacturing of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a motor control method, device, motor, frequency converter, storage medium, and computer program product to solve the problem that during the frequency conversion commissioning and startup of a motor (such as a permanent magnet synchronous motor), if the three-phase current waveform of the frequency converter output becomes unstable, it can lead to abnormal motor operation or even equipment damage, affecting motor commissioning efficiency and posing a high risk of equipment damage. The invention achieves this by first controlling the motor to reduce its frequency after the three-phase current waveform becomes unstable, and then adjusting the PI parameters to control the motor to increase its frequency, thereby reducing commissioning time and the risk of equipment damage, and improving commissioning efficiency and motor stability. This frequency converter involves the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0005] This invention provides a motor control method, comprising: acquiring the motor's current signal during the motor's frequency conversion debugging and startup process; after determining that the motor's current waveform is unstable and controlling the motor to operate at a back-off frequency, determining the motor's corrected PI parameter based on the motor's current signal; applying the motor's corrected PI parameter to the control loop of the motor's control system, and attempting to raise the motor's frequency to the frequency before the motor's back-off frequency operation.

[0006] In some embodiments, the method further includes: determining whether the motor current waveform instability occurs based on the motor current signal; if it is determined that the motor current waveform instability does not occur, controlling the motor to continue operating at an increased frequency; if it is determined that the motor current waveform instability occurs, controlling the motor to operate at a lower frequency based on the degree of the current waveform instability; after controlling the motor to operate at a lower frequency for a set time, determining whether the motor current waveform instability has recovered based on the motor current signal; if it is determined that the motor current waveform instability has recovered, determining the corrected PI parameter of the motor based on the motor current signal; if it is determined that the motor current waveform instability has not recovered, controlling the motor frequency to decrease to a preset minimum frequency, and then determining the corrected PI parameter of the motor based on the motor current signal.

[0007] In some embodiments, determining whether current waveform instability of the motor occurs based on the current signal of the motor includes: determining parameters characterizing current waveform instability of the motor based on the current signal of the motor; the parameters characterizing current waveform instability of the motor include: the total harmonic distortion rate of the current waveform of the motor, and / or determining the distortion coefficient of the current waveform of the motor; if it is determined that the total harmonic distortion rate of the current waveform of the motor is greater than a preset first distortion rate threshold or the distortion coefficient of the current waveform of the motor is greater than a preset first distortion coefficient threshold, then it is determined that current waveform instability of the motor has occurred.

[0008] In some embodiments, the degree of instability in the motor's current waveform is characterized by the total harmonic distortion (THD) of the motor's current waveform and / or the distortion coefficient of the motor's current waveform. Controlling the motor to operate at a lower frequency based on the degree of instability includes: if it is determined that the THD of the motor's current waveform is greater than a preset first distortion rate threshold and less than a preset second distortion rate threshold, and it is determined that the distortion coefficient of the motor's current waveform is greater than a preset first distortion coefficient threshold and less than a preset second distortion coefficient threshold, then controlling the motor to operate at a preset first frequency; the preset second distortion rate threshold is greater than the preset first distortion rate threshold, and the preset second distortion coefficient threshold is greater than a preset... The first distortion coefficient threshold; if it is determined that the total harmonic distortion rate of the motor's current waveform is greater than or equal to a preset second distortion rate threshold and less than a preset third distortion rate threshold, and it is determined that the distortion coefficient of the motor's current waveform is greater than or equal to a preset second distortion rate threshold and less than a preset third distortion rate threshold, then the motor is controlled to operate at a preset second frequency; the preset second frequency is greater than the preset first frequency; if it is determined that the total harmonic distortion rate of the motor's current waveform is greater than or equal to a preset third distortion rate threshold, and it is determined that the distortion coefficient of the motor's current waveform is greater than or equal to a preset third distortion rate threshold, then the motor is controlled to operate at a preset third frequency; the preset third frequency is greater than the preset second frequency.

[0009] In some implementations, the method further includes: after attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation, continuing to determine whether current waveform instability of the motor occurs based on the motor's current signal; if it is determined that no current waveform instability of the motor occurs after attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation, then controlling the motor to continue increasing the frequency operation, and then continuing to determine whether current waveform instability of the motor occurs based on the motor's current signal; and recording the current instability parameters that occurred before attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation, and after attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation, determining whether current waveform instability of the motor occurs; and recording the current instability parameters that occurred before attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation, and the current instability parameters that occurred after attempting to increase the motor frequency to the frequency prior to the motor's reversal frequency operation. The PI parameters for when the motor current waveform becomes unstable are used to establish a correspondence between the set instability parameters and the set PI parameters, which are then updated to a preset historical fault database. If the motor current waveform instability is still detected after attempting to increase the motor frequency to the frequency before the motor reverts to its previous operating frequency, the motor frequency is reduced to the frequency before the frequency increase. The current instability parameters and the current PI parameters are recorded when the current waveform instability still occurs after attempting to increase the motor frequency to the frequency before the motor reverts to its previous operating frequency. The number of failed attempts to increase the motor frequency to the frequency before the motor reverts to its previous operating frequency is incremented by 1 to obtain the cumulative count of failed attempts to increase the motor frequency to the frequency before the motor reverts to its previous operating frequency.

[0010] In some implementations, the method further includes: determining whether the cumulative number of failed attempts to increase the motor frequency to the frequency prior to the motor's regression frequency has reached a set threshold; if the cumulative number of failed attempts to increase the motor frequency to the frequency prior to the motor's regression frequency has reached the set threshold, then stopping the attempts to increase the motor frequency to the frequency prior to the motor's regression frequency and initiating a reminder message and a recording message indicating the failure of the attempts to increase the motor frequency to the frequency prior to the motor's regression frequency; if the cumulative number of failed attempts to increase the motor frequency to the frequency prior to the motor's regression frequency has not reached the set threshold, then re-determining the corrected PI parameters of the motor based on the motor's current signal.

[0011] In some embodiments, determining the corrected PI parameter of the motor based on the motor's current signal includes: determining a parameter characterizing the current waveform instability of the motor based on the motor's current signal, denoted as the motor's current waveform instability parameter; determining the set IP parameter corresponding to the set instability parameter that is the same as the motor's current waveform instability parameter in a preset historical fault database as the IP parameter corresponding to the motor's current waveform instability parameter; if there is only one IP parameter corresponding to the motor's current waveform instability parameter, then the IP parameter corresponding to the motor's current waveform instability parameter is used as the corrected PI parameter of the motor; if there are two or more IP parameters corresponding to the motor's current waveform instability parameter, then the weighted average of the two or more IP parameters corresponding to the motor's current waveform instability parameter is used as the corrected PI parameter of the motor.

[0012] Alternatively, determining the corrected PI parameter of the motor based on the motor's current signal further includes: determining a parameter characterizing the current waveform instability of the motor based on the motor's current signal, denoted as the motor's current waveform instability parameter; setting the instability parameter and setting IP parameter change rules in a preset fuzzy rule library, determining the setting IP parameter change rule corresponding to the same setting instability parameter as the motor's current waveform instability parameter as the IP parameter change rule corresponding to the motor's current waveform instability parameter; and correcting the motor's current IP parameter based on the IP parameter change rule corresponding to the motor's current waveform instability parameter to obtain the corrected PI parameter of the motor.

[0013] In line with the above method, another aspect of the present invention provides a motor control device, comprising: an acquisition unit configured to acquire a current signal of the motor; a control unit configured to, after determining that the current waveform of the motor is unstable and controlling the motor to operate at a back-off frequency, determine a corrected PI parameter of the motor based on the current signal of the motor; the control unit is further configured to apply the corrected PI parameter of the motor to the control loop of the motor control system, and attempt to raise the frequency of the motor to the frequency before the motor operates at the back-off frequency.

[0014] In conjunction with the above-described device, the present invention further provides a frequency converter, comprising: the motor control device described above.

[0015] In conjunction with the above-described device, the present invention further provides a motor, comprising: the motor control device described above, or the frequency converter described above.

[0016] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located executes the steps of the motor control method described above.

[0017] In conjunction with the above method, the present invention further provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the motor control method described above.

[0018] This invention addresses the problem of unstable three-phase current waveforms in a motor during frequency conversion commissioning (i.e., instability in the three-phase current signal waveform of the motor or instability in the three-phase current waveform output from the frequency converter). During the start-up of the frequency conversion commissioning, the current signal of the motor is acquired. After confirming the occurrence of current waveform instability and controlling the motor to operate at a lower frequency, a corrected PI parameter for the motor is determined based on the current signal. This corrected PI parameter is applied to the control loop of the motor's control system, attempting to raise the motor frequency to the frequency before the motor's lower frequency operation. Therefore, by first controlling the motor to lower its frequency after the three-phase current waveform becomes unstable, and then adjusting the PI parameter to raise the motor frequency, commissioning time and the risk of equipment damage are reduced, improving commissioning efficiency and motor stability. This frequency converter involves the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0019] Specifically, in the solution of this invention, addressing the problem of unstable three-phase current waveforms of the motor during motor frequency conversion debugging (i.e., unstable current waveforms of the motor's three-phase current signals or unstable current waveforms of the three-phase output from the frequency converter), when the unstable current waveforms of the motor's three-phase current signals are determined based on the motor's three-phase current signals, the motor frequency is controlled to revert based on the degree of instability. After a set time (e.g., 5 seconds), a new PI parameter is determined based on the current instability characteristics of the motor's three-phase current signals to improve the current instability characteristics. The new PI parameter is applied to the control loop (e.g., speed loop and / or current loop) of the motor's control system to control the motor to attempt to increase its frequency to restore the motor's operating frequency when the current instability characteristics occur. The system continues to determine whether the current waveforms of the motor's three-phase current signals become unstable. If the number of failed attempts to increase the motor's frequency reaches a set number (e.g., 3 times), then... The system stops controlling the motor to increase its frequency and initiates a fault alert message. Specifically, it determines new PI parameters to improve the current instability characteristics based on the current waveform of the motor's three-phase current signal. This can be achieved using either a historical temperature database approach or a fuzzy rule base approach. The historical temperature database approach involves determining the new PI parameters corresponding to the most effective PI parameters for improving historical instability characteristics based on historical instability characteristics of the motor's three-phase current signal from a historical problem database. The fuzzy rule base approach involves adjusting the current PI parameters according to the magnitude of the current instability characteristics of the motor's three-phase current signal to obtain new PI parameters. Therefore, by first controlling the motor to decrease its frequency after the three-phase current waveform becomes unstable, and then adjusting the PI parameters to increase the motor's frequency, the system reduces debugging time and the risk of equipment damage, improving debugging efficiency and motor stability. This frequency converter involves the manufacturing of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating an embodiment of the motor control method of the present invention;

[0023] Figure 2 This is a flowchart illustrating an embodiment of the method of the present invention for determining the timing of correcting the PI parameter of the motor after the current waveform of the motor becomes unstable;

[0024] Figure 3This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the current waveform of the motor is unstable;

[0025] Figure 4 This is a flowchart illustrating an embodiment of the method of the present invention, which attempts to increase the frequency of the motor to the frequency before the motor returns to its previous operating frequency, and then determines whether the current waveform instability of the motor is restored.

[0026] Figure 5 This is a flowchart illustrating an embodiment of the method of the present invention, which controls the cumulative number of failed attempts to raise the frequency of the motor to the frequency prior to the motor's regression frequency.

[0027] Figure 6 This is a flowchart illustrating an embodiment of the method of the present invention for determining the corrected PI parameters of the motor based on a preset historical fault database;

[0028] Figure 7 This is a flowchart illustrating an embodiment of the method of the present invention for determining the corrected PI parameters of the motor according to a preset fuzzy rule library;

[0029] Figure 8 This is a schematic diagram of a structure of an embodiment of the motor control device of the present invention;

[0030] Figure 9 This is a flowchart illustrating an embodiment of an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process.

[0031] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0032] 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] Considering that during the frequency converter commissioning and startup of a motor (such as a permanent magnet synchronous motor), if the three-phase power output by the frequency converter exhibits current waveform instability, it can lead to abnormal motor operation or even equipment damage, affecting motor commissioning efficiency and posing a significant risk of equipment damage. For example, during the frequency converter commissioning and startup of a motor (such as a permanent magnet synchronous motor), the three-phase power output by the frequency converter may exhibit current waveform instability due to factors such as improper parameter settings, external interference, or system response delays, leading to abnormal motor operation, reduced efficiency, or even equipment damage.

[0035] The motor control system in the relevant scheme lacks an effective automatic detection and response mechanism when the three-phase power output from the frequency converter becomes unstable. It cannot achieve automatic reversion of motor frequency (i.e., motor speed), adaptive adjustment of PI parameters, or frequency increase attempts, thereby increasing commissioning time and the risk of equipment damage, and affecting commissioning efficiency and system stability.

[0036] Therefore, the present invention proposes a motor control method, specifically an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process. Upon detecting current waveform instability in the three-phase power output from the frequency converter, the method automatically reduces the frequency (i.e., lowers the motor frequency). Furthermore, by comparing historical problems with the current instability waveform, it identifies similar problematic current waveforms and corresponding PI parameters, modifies the current PI parameters using the PI parameters in the problem model, and then controls the motor to attempt frequency increase and startup. This reduces commissioning time and the risk of equipment damage, improving commissioning efficiency and system stability.

[0037] According to an embodiment of the present invention, a method for controlling a motor is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. This motor control method is applied to control the motor based on a motor control system, specifically controlling the three-phase current of the motor based on the motor control system; the motor control system has a control loop, which includes a current loop and / or a speed loop. In the solution of the present invention, as... Figure 1 As shown, the motor control method includes steps S110 to S130.

[0038] In step S110, during the motor frequency conversion debugging and start-up process, the current signal of the motor is acquired, specifically the three-phase current signal of the motor (i.e. the three-phase power signal output by the frequency converter) collected by the Hall sensor.

[0039] In step S120, after determining that the current waveform of the motor is unstable and controlling the motor to operate at the back frequency, the corrected PI parameter of the motor is determined based on the current signal of the motor.

[0040] In step S130, the corrected PI parameters of the motor are applied to the control loop of the motor's control system, and an attempt is made to raise the frequency of the motor to the frequency before it was running at the regressed frequency.

[0041] In the present invention, during the frequency conversion debugging and startup process of the motor, the current signal of the motor is acquired. After determining that the current waveform of the motor is unstable and controlling the motor to operate at a lower frequency, the corrected PI parameter of the motor is determined based on the current signal. The corrected PI parameter of the motor is applied to the control loop of the motor control system, and an attempt is made to increase the frequency of the motor to the frequency before the motor operates at the lower frequency. Thus, by first controlling the motor to reduce the frequency after the three-phase current waveform of the motor becomes unstable, and then adjusting the PI parameter to control the motor to increase the frequency, debugging time and equipment damage risk are reduced, and debugging efficiency and motor stability are improved.

[0042] In some embodiments, in the motor control method of the present invention, before determining the corrected PI parameter of the motor based on the current signal of the motor in step S120, the method further includes a process of determining the timing of the corrected PI parameter of the motor after the current waveform of the motor becomes unstable.

[0043] The following is combined Figure 2 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for determining the timing of the corrected PI parameter of the motor after the current waveform of the motor becomes unstable. It further illustrates the specific process of determining the timing of the corrected PI parameter of the motor after the current waveform of the motor becomes unstable, including steps S210 to S260.

[0044] Step S210: Before determining the corrected PI parameter of the motor based on the motor's current signal, determine whether the motor's current waveform instability has occurred based on the motor's current signal.

[0045] Step S220: If it is determined that no current waveform instability has occurred in the motor, then the motor is controlled to continue increasing its frequency. Specifically, the motor is controlled to continue increasing its frequency towards the set initial target frequency. If no instability occurs, the frequency will continuously increase towards the set initial target frequency. If instability occurs during the frequency increase process, the frequency of the instability point is recorded and the frequency is reverted. After adjusting the parameters, the system attempts to increase the frequency to the instability point frequency, and once the instability point frequency is reached, operation is maintained.

[0046] Step S230: If it is determined that the current waveform of the motor is unstable, the motor is controlled to operate at a reversal frequency according to the degree of the current waveform instability.

[0047] Step S240: After controlling the motor to run at the reversal frequency for a set time, determine whether the current waveform instability of the motor has been restored based on the current signal of the motor; wherein, the set time is, for example, 5 seconds.

[0048] Step S250: If it is determined that the current waveform instability of the motor has been restored, then the corrected PI parameter of the motor is determined according to the current signal of the motor; then, the corrected PI parameter of the motor is applied to the control loop of the motor control system, and an attempt is made to make the motor run at the frequency before the motor returned to the operating frequency.

[0049] Step S260: If it is determined that the current waveform instability of the motor has not been recovered, the frequency of the motor is controlled to be reduced to a preset minimum frequency. Then, the corrected PI parameter of the motor is determined according to the current signal of the motor. Then, the corrected PI parameter of the motor is applied to the control loop of the motor control system, and an attempt is made to raise the frequency of the motor to the frequency before the motor returned to the operating frequency.

[0050] Preferably, during the frequency converter debugging and startup process of the motor, the motor's current signal is acquired, specifically the three-phase current signal of the motor (i.e., the three-phase power signal output by the frequency converter) collected by a Hall sensor. Then, based on the motor's current signal, it is determined whether the motor's current waveform is unstable. If it is determined that the motor's current waveform is unstable, the motor is controlled to return to its previous frequency. Conversely, if it is determined that the motor's current waveform is not unstable, the motor is controlled to continue operating at the set initial target frequency. After a set time, it is again determined whether the motor's current waveform is unstable based on the motor's current signal; for example, the set time is 5 seconds. If it is again determined that the motor's current waveform is not unstable, the corrected PI parameter of the motor is determined based on the motor's current signal. Then, the corrected PI parameter of the motor is applied to the control loop of the motor's control system, and an attempt is made to raise the motor's frequency to the frequency before the motor returned to its previous operating frequency. If the motor's current waveform instability is again confirmed, the motor's frequency is reduced to a preset minimum frequency. Then, based on the motor's current signal, a corrected PI parameter for the motor is determined. This corrected PI parameter is then applied to the control loop of the motor's control system, attempting to raise the motor's frequency to the frequency it previously operated at before the reversal frequency.

[0051] This invention proposes an adaptive intelligent control scheme for high-speed permanent magnet synchronous motors (PMSMs) during frequency conversion commissioning and startup when the three-phase current waveform output from the frequency converter becomes unstable. Upon detecting this instability, the scheme automatically reduces the frequency (i.e., lowers the motor frequency). By comparing historical problems with the current instability waveform, it identifies similar problematic current waveforms and corresponding PI parameters. The scheme then modifies the current PI parameters using the PI parameters from the problem model, resulting in modified PI parameters. Based on these modified PI parameters, the motor is controlled to attempt frequency increase and startup. This reduces commissioning time and the risk of equipment damage, improving commissioning efficiency and the stability of the motor control system. Therefore, this invention solves the problem that in the frequency conversion commissioning and startup of motors (such as PMSMs), current waveform instability in the three-phase current output from the frequency converter can lead to abnormal motor operation or even equipment damage, affecting commissioning efficiency and posing a high risk of equipment damage. It also addresses the issue that in the frequency conversion commissioning and startup of motors (such as high-speed PMSMs), when current waveform instability occurs in the three-phase current output from the frequency converter, the motor cannot revert to its previous frequency and intelligently adjust the PI parameters based on historical problem models to attempt frequency increase autonomously.

[0052] In some implementations, the specific process of determining whether the motor current waveform instability occurs based on the motor current signal in step S210 is illustrated in the following exemplary description.

[0053] The following is combined Figure 3 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the current waveform of the motor is unstable. It further illustrates the specific process of determining whether the current waveform of the motor is unstable in step S210, including steps S310 to S320.

[0054] Step S310: Based on the current signal of the motor, determine the parameters used to characterize the instability of the current waveform of the motor; the parameters used to characterize the instability of the current waveform of the motor include: the total harmonic distortion rate of the current waveform of the motor, and / or determine the distortion coefficient of the current waveform of the motor; the total harmonic distortion rate of the current waveform of the motor is like the total harmonic distortion rate (THD) of the three-phase current signal of the motor, and the distortion coefficient of the current waveform of the motor is like the waveform distortion coefficient (WDF) of the three-phase current signal of the motor.

[0055] Step S320: If it is determined that the total harmonic distortion (THD) of the motor's current waveform is greater than a preset first distortion rate threshold or the distortion coefficient of the motor's current waveform is greater than a preset first distortion coefficient threshold, then it is determined that the motor's current waveform is unstable. The preset first distortion rate threshold is, for example, the THD_threshold (e.g., 10%); the preset first distortion coefficient threshold is, for example, the WDF_threshold (e.g., 10%).

[0056] Figure 9 This is a flowchart illustrating an embodiment of an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process. Figure 9 As shown, an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process includes the following steps:

[0057] Step 1: Monitor the current waveform of the three-phase current signal of the motor in real time, and then proceed to Step 2.

[0058] During motor startup and commissioning, the three-phase current signal of the motor (i.e., the three-phase power signal output by the inverter) is collected by the Hall current sensor. After AD conversion, it is sent to the inverter controller (such as a DSP controller) for real-time analysis to determine whether there is an unstable current waveform in the three-phase power output by the inverter. If it is determined that there is an unstable current waveform in the three-phase power output by the inverter, step 2 is executed. If it is determined that there is no unstable current waveform in the three-phase power output by the inverter, the current frequency is maintained.

[0059] In step 1, the current waveform of the three-phase current signal of the motor is monitored in real time, specifically including the following steps:

[0060] Step 11: When the signal after AD conversion is sent to the inverter controller (such as DSP controller) for real-time analysis, the sliding window fast Fourier transform (FFT) algorithm can be used to perform real-time analysis to obtain the total harmonic distortion (THD) and waveform distortion coefficient (WDF) of the three-phase current signal of the motor. Then, step 12 is executed.

[0061] In step 11, the motor control system uses a sliding window FFT algorithm to extract features from the three-phase current signal waveform of the motor. Based on the extracted features, the total harmonic distortion (THD) and waveform distortion coefficient (WDF) of the three-phase current signal waveform are calculated, thus obtaining the total harmonic distortion (THD) and waveform distortion coefficient (WDF) of the three-phase current signal of the motor. In other words, by inputting the three-phase current signal of the motor into the sliding window FFT algorithm, the characteristic parameters of the three-phase current signal of the motor (such as THD, WDF, frequency point, load state, etc.) are obtained.

[0062] Step 12: Determine whether the total harmonic distortion (THD) of the motor's three-phase current signal is greater than the total harmonic distortion threshold (THD_threshold, e.g., 10%) or the waveform distortion coefficient (WDF) of the motor's three-phase current signal is greater than the waveform distortion coefficient threshold (WDF_threshold, e.g., 10%).

[0063] If it is determined that THD > THD_threshold (e.g., 10%) or WDF > WDF_threshold (e.g., 10%), then it is determined that the current waveform of the three-phase current signal of the motor is unstable, and then step 2 is executed;

[0064] If the condition that THD > THD_threshold (e.g., 10%) or WDF > WDF_threshold (e.g., 10%) is not met, it is determined that the current waveform of the three-phase current signal of the motor is not unstable, and the motor is controlled to maintain the current frequency operation.

[0065] In the present invention, based on the current signal of the motor, it is determined whether the current waveform of the motor is unstable. Then, after detecting the current waveform instability of the three-phase power output by the frequency converter, the frequency is automatically reduced (i.e., the motor frequency is lowered). By comparing the current instability waveform with historical problems, similar problematic current waveforms and corresponding PI parameters are found. The current PI parameters are modified using the PI parameters in the problem model to obtain the modified PI parameters. Then, based on the modified PI parameters, the motor is controlled to attempt to start with a higher frequency. This can reduce debugging time and the risk of equipment damage, and improve debugging efficiency and the stability of the motor control system.

[0066] In some embodiments, the degree of instability of the motor's current waveform is characterized by the total harmonic distortion rate and / or the distortion coefficient of the motor's current waveform.

[0067] In step S230, the motor's reversal frequency is controlled according to the degree of instability in the motor's current waveform, including any of the following situations:

[0068] The first scenario for controlling the motor to operate at a lower frequency: If it is determined that the total harmonic distortion (THD) of the motor's current waveform is greater than a preset first distortion threshold and less than a preset second distortion threshold, and it is determined that the current waveform distortion coefficient of the motor is greater than a preset first distortion coefficient threshold and less than a preset second distortion coefficient threshold, then the motor is controlled to operate at a preset first frequency. The preset second distortion threshold is greater than the preset first distortion threshold, and the preset second distortion coefficient threshold is greater than the preset first distortion coefficient threshold. Specifically, the preset first distortion threshold is, for example, the total harmonic distortion threshold THD_threshold (e.g., 10%); the preset first distortion coefficient threshold is, for example, the waveform distortion coefficient threshold WDF_threshold (e.g., 10%); the preset second distortion threshold is, for example, the total harmonic distortion threshold THD_threshold (e.g., 15%); and the preset second distortion coefficient threshold is, for example, the waveform distortion coefficient threshold WDF_threshold (e.g., 15%). The preset first frequency is, for example, 5Hz.

[0069] The second scenario for controlling the motor to operate at a regressive frequency: If it is determined that the total harmonic distortion (THD) of the motor's current waveform is greater than or equal to a preset second distortion threshold and less than a preset third distortion threshold, and it is determined that the current waveform distortion coefficient of the motor is greater than or equal to a preset second distortion coefficient threshold and less than a preset third distortion coefficient threshold, then the motor is controlled to operate at a preset second frequency. The preset second frequency is greater than the preset first frequency; the preset third distortion threshold is greater than the preset second distortion threshold; and the preset third distortion coefficient threshold is greater than the preset second distortion coefficient threshold. The preset third distortion threshold is, for example, the total harmonic distortion threshold THD_threshold (e.g., 20%); the preset third distortion coefficient threshold is, for example, the waveform distortion coefficient threshold WDF_threshold (e.g., 20%). The preset second frequency is, for example, 10Hz.

[0070] The third scenario for controlling the motor to operate at a regressive frequency: If it is determined that the total harmonic distortion (THD) of the motor's current waveform is greater than or equal to a preset third distortion rate threshold, and it is determined that the current waveform distortion coefficient of the motor is greater than or equal to a preset third distortion coefficient threshold, then the motor is controlled to operate at a preset third frequency; the preset third frequency is greater than the preset second frequency; wherein, the preset third distortion rate threshold is, for example, the total harmonic distortion (THD) threshold (e.g., 20%); the preset third distortion coefficient threshold is, for example, the waveform distortion coefficient threshold (WDF) threshold (e.g., 20%). The preset third frequency is, for example, 15Hz.

[0071] like Figure 9As shown, an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process further includes the following steps:

[0072] Step 2: Execute the motor's dynamic frequency rollback mechanism, and then proceed to Step 3.

[0073] In step 2, when instability of the three-phase current waveform of the motor is detected, the motor control system enters the motor frequency rollback phase, and then proceeds to step 3. This is because continuing to increase the motor frequency after the three-phase current waveform of the motor is unstable will cause the motor to malfunction and shut down.

[0074] In step 2, the motor control system enters the motor frequency rollback phase, which specifically includes the following steps:

[0075] Step 21: Perform motor frequency rollback operation according to the degree of instability of the three-phase current signal of the motor, and then proceed to step 22.

[0076] In step 21, frequency rollback operations are performed according to the degree of instability, specifically including:

[0077] If the current waveform of the three-phase current signal of the motor is slightly unstable (10%≤THD<15% and 10%≤WDF<15%), the motor frequency will drop by 5Hz.

[0078] If the current waveform of the three-phase current signal of the motor is moderately unstable (15%≤THD<20% and 15%≤WDF<20%), the motor frequency will drop by 10Hz.

[0079] If the current waveform of the three-phase current signal of the motor is severely unstable (THD≥20% and 20%≤WDF), the motor frequency will drop by 15Hz.

[0080] In the solution of this invention, the motor control system automatically detects and performs a frequency rollback operation when the current waveform of the three-phase power output from the frequency converter becomes unstable, so that the motor operating state can be quickly restored to stability. This solves the problem of motor shutdown and equipment damage caused by the current waveform instability of the three-phase power output from the frequency converter during motor debugging, and improves the efficiency of motor debugging.

[0081] In the present invention, after detecting instability in the three-phase current waveform of the inverter output, the frequency is automatically reduced (i.e., the motor frequency is lowered). Furthermore, an intelligent control method is added, namely: the intelligent capability to intelligently modify the PI parameters of the current loop and / or speed loop based on a historical problem model and autonomously increase the frequency. The method of automatically reducing the frequency (i.e., lowering the motor frequency) after detecting instability in the three-phase current waveform of the inverter output can adopt relevant methods in the art, such as the methods described in application number 2025119567483 for detecting instability in the three-phase current waveform of the inverter output and controlling the motor frequency reduction after detecting instability in the three-phase current waveform of the inverter output.

[0082] In some embodiments, in the motor control method described in the present invention, after applying the corrected PI parameter of the motor to the control loop of the motor control system in step S130 and attempting to raise the frequency of the motor to the frequency before the motor reverts to the operating frequency, the method further includes: determining whether the current waveform instability of the motor has been restored after attempting to raise the frequency of the motor to the frequency before the motor reverts to the operating frequency.

[0083] The following is combined with Figure 4 The illustrated flowchart shows an embodiment of the method of the present invention, which attempts to increase the frequency of the motor to the frequency before the motor returns to its original operating frequency and then determines whether the current waveform instability of the motor has been restored. The flowchart further illustrates the specific process of determining whether the current waveform instability of the motor has been restored after attempting to increase the frequency of the motor to the frequency before the motor returns to its original operating frequency, including steps S410 to S430.

[0084] Step S410: After applying the corrected PI parameters of the motor to the control loop of the motor control system and attempting to raise the frequency of the motor to the frequency before it was running at the reverted frequency, that is, after attempting to raise the frequency of the motor to the frequency before it was running at the reverted frequency, continue to determine whether the current waveform of the motor is unstable based on the current signal of the motor.

[0085] Step S420: If, after attempting to increase the motor frequency to the frequency before the motor reverts to its operating frequency, it is determined that no current waveform instability occurs, then the motor is controlled to continue increasing its frequency. Specifically, the motor is controlled to continue increasing its frequency towards the set initial target frequency. Then, based on the motor's current signal, it is determined whether current waveform instability occurs. The current instability parameter when current waveform instability occurred before attempting to increase the motor frequency to the frequency before the motor reverts to its operating frequency is recorded, as well as the PI parameter when current waveform instability is determined not to occur after attempting to increase the motor frequency to the frequency before the motor reverts to its operating frequency. This establishes a correspondence between the set instability parameter and the set PI parameter, and updates the preset historical fault database.

[0086] Step S430: If, after attempting to increase the motor frequency to the frequency before the motor reverts to its previous operating frequency, current waveform instability still occurs, then the motor frequency is controlled to decrease to the frequency before the frequency increase. The current instability parameter and the current PI parameter are recorded. The number of failed attempts to increase the motor frequency to the previous operating frequency is incremented by 1 to obtain the cumulative count of failed attempts. The cumulative count of failed attempts to increase the motor frequency to the previous operating frequency is represented as i = i + 1, where i is initially 0.

[0087] In the solution of this invention, by intelligently modifying the PI parameters and attempting to increase the frequency based on the historical problem model during the variable frequency commissioning and startup process of the motor, the motor control system has a certain self-learning ability and can quickly respond when similar problems occur, thereby shortening the commissioning cycle and improving the robustness of the system.

[0088] In some embodiments, in the motor control method described in the present invention, after obtaining the accumulated number of failed attempts to increase the frequency of the motor to the frequency before the motor regression frequency in step S430, the method further includes: controlling the accumulated number of failed attempts to increase the frequency of the motor to the frequency before the motor regression frequency.

[0089] The following is combined with Figure 5The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for controlling the cumulative number of failed attempts to raise the frequency of the motor to the frequency before the motor returns to its operating frequency. The specific process of controlling the cumulative number of failed attempts to raise the frequency of the motor to the frequency before the motor returns to its operating frequency includes: steps S510 to S530.

[0090] Step S510: Determine whether the cumulative number of failed attempts to raise the frequency of the motor to the frequency before the motor reverts to operation has reached a set threshold number; wherein, the set threshold number is, for example, 3 times.

[0091] Step S520: If it is determined that the cumulative number of failed attempts to increase the frequency of the motor to the frequency before the motor reverts to operation has reached a set threshold, then stop attempting to increase the frequency of the motor to the frequency before the motor reverts to operation, and initiate an alert message and a record message indicating the failure of attempting to increase the frequency of the motor to the frequency before the motor reverts to operation.

[0092] Step S530: If it is determined that the cumulative number of failed attempts to raise the frequency of the motor to the frequency before the motor reverts to its operating frequency has not reached the set threshold, then after controlling the frequency of the motor to decrease to the frequency before the motor raises its operating frequency, the corrected PI parameter of the motor is re-determined based on the current signal of the motor, and then the corrected PI parameter of the motor is re-applied to the control loop of the motor control system, and the motor is re-attempted to raise its operating frequency to the frequency before the motor reverts to its operating frequency.

[0093] In the solution of this invention, by stopping the motor control system after multiple failed attempts and waiting for manual intervention, the waste of resources and potential risks caused by the continuous invalid attempts of the motor control system are avoided, the testing efficiency is affected, and the safety of the debugging process is ensured.

[0094] In some implementations, step S120, determining the corrected PI parameter of the motor based on the motor's current signal, includes: determining the corrected PI parameter of the motor based on a preset historical fault database.

[0095] The following is combined with Figure 6 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the corrected PI parameter of the motor according to a preset historical fault database. The specific process of determining the corrected PI parameter of the motor according to the preset historical fault database in step S120 is further explained, including steps S610 to S640.

[0096] Step S610: Based on the current signal of the motor, determine the parameters used to characterize the current waveform instability of the motor, and denot them as the current waveform instability parameters of the motor.

[0097] Step S620: Based on the correspondence between the set instability parameters and the set IP parameters in the preset historical fault database, determine the set IP parameter corresponding to the set instability parameter that is the same as the current waveform instability parameter of the motor in the correspondence as the IP parameter corresponding to the current waveform instability parameter of the motor.

[0098] Step S630: If the number of IP parameters corresponding to the current waveform instability parameters of the motor is one, then the IP parameter corresponding to the current waveform instability parameters of the motor is used as the corrected PI parameter of the motor.

[0099] Step S640: If there are two or more IP parameters corresponding to the current waveform instability parameters of the motor, then the weighted average of the two or more IP parameters corresponding to the current waveform instability parameters of the motor is used as the corrected PI parameter of the motor.

[0100] like Figure 9 As shown, an adaptive intelligent control method for a high-speed permanent magnet synchronous motor after the current waveform of the three-phase power output from the frequency converter becomes unstable during the frequency conversion commissioning and startup process further includes the following steps:

[0101] Step 22: After reversing, keep running for a period of time (e.g., 5 seconds). If the current waveform of the motor's three-phase current signal is detected to have returned to stability, then execute Step 3 to enter the PI parameter adjustment stage of the current loop and / or speed loop; otherwise, continue to reversing to the lowest safe frequency (e.g., 10Hz) and execute Step 3 to enter the PI parameter adjustment stage of the current loop and / or speed loop.

[0102] Step 3: After performing the motor frequency rollback operation according to the degree of instability of the three-phase current signal of the motor, the PI parameters are adaptively adjusted based on the historical model, and then Step 4 is executed.

[0103] In step 3, the PI parameter is adaptively adjusted based on the historical model, specifically including the following steps:

[0104] Step 31: The motor control system has a built-in historical problem model database that records the characteristic parameters (such as THD, WDF, frequency point, load state) of the current waveform instability of the three-phase current signal of the motor in the past, as well as the corresponding PI parameter adjustment strategies. Then, step 32 is executed.

[0105] Step 32: After the motor frequency returns to normal, the motor control system matches the current instability characteristics of the motor's three-phase current signal waveform with the historical case of the most similar historical PI parameter in the database. If there is one historical parameter in the database that is most similar to the current instability characteristics of the motor's three-phase current signal waveform, then that historical parameter is used as the new PI parameter combination. If there are two or more historical parameters in the database that are most similar to the current instability characteristics of the motor's three-phase current signal waveform, then a weighted average method is used to generate a new PI parameter combination. Then, step 4 is executed to apply the new PI parameter combination to the current control loop (such as the current loop and / or speed loop). The current parameters can be adjusted using the percentage trend of the instability point parameters and stable parameters in the historical fault model. For example, using the stable K value from the historical fault model... P Compared to the unstable K P If it increases by 12%, then the current K P It should be increased by 12%; if the trend is downward, use a negative value. If there are multiple similar waveforms in the historical fault model, take the average of the percentage trends.

[0106] The new PI parameter combination includes a new proportional parameter K. p_new and the new integration parameter K i_new .

[0107] For example: K p_new =(αK p_hist1 +βK p_hist2 )Kp+Kp, K i_new .

[0108] Among them, K p_hist1 K is the first similarity ratio parameter in the database. p_hist2 α is the second similarity ratio parameter in the database, and β are both weighted calculation coefficients with α+β=1.

[0109] Specifically, K p_hist1 The percentage trend of the first similarity ratio parameter in the historical model database; K p_hist2 α represents the percentage trend of the second similarity ratio parameter in the database; Kp is the original instability parameter. α and β are weighted calculation coefficients, and α + β = 1; α ≥ β. α and β can be selected through debugging. The debugging reference is as follows: For the first attempt, α = β. If it fails, make a second attempt by increasing the proportion of α, such as α = 2β.

[0110] Step 4: After generating a new PI parameter combination, apply the new PI parameter combination to the current control loop (such as the current loop and / or speed loop) to implement the motor frequency increase attempt and failure handling mechanism, and then proceed to step 5.

[0111] After the new PI parameters take effect, the motor control system attempts to increase the motor frequency (by the same amount as the previous frequency), while continuously monitoring the three-phase current waveform of the motor. If the three-phase current waveform becomes unstable again during the frequency increase process, the motor control system reverts to the previous stable frequency (i.e., the revert frequency) and records the current waveform instability characteristics of the motor's three-phase current signal along with the current PI parameter combination for maintenance personnel reference. The system will run stably for a few seconds after the new PI parameters take effect before increasing the frequency. The motor control system will attempt a maximum of three different PI parameter combinations. If all attempts fail, it will stop attempting to increase the motor frequency and issue an alarm, awaiting manual intervention.

[0112] Step 5: Update the historical problem model.

[0113] If the system successfully returns to stable operation after an adjustment, the motor control system will write the current waveform instability characteristics of the motor's three-phase current signal and the final effective PI parameter combination into the historical problem model database. This will serve as the characteristic parameters (such as THD, WDF, frequency point, and load state) of the current waveform instability phenomenon of the motor's three-phase current signal in the past, along with the corresponding PI parameter adjustment strategy, for rapid response and parameter optimization in subsequent similar problems.

[0114] In steps 1 to 5, during the motor commissioning and startup process, the motor control system enables the motor to autonomously reduce its frequency after the current waveform of the three-phase current signal becomes unstable. After the motor stabilizes at the reduced frequency, it autonomously modifies the PI parameters (determining how to modify them based on the historical problem model) and enables the motor to autonomously increase its frequency to the instability point (i.e., the operating frequency of the motor when the current waveform of the three-phase current signal becomes unstable) according to the modified PI parameters. After attempting to enable the motor to autonomously increase its frequency to the instability point according to the modified PI parameters, if the current waveform of the three-phase current signal of the motor is detected to be unstable again, it continues to reduce the frequency to the stable point (i.e., the frequency at which the motor runs stably, or the frequency at which the motor can run stably after reducing its frequency), and repeats this process. If multiple attempts to autonomously increase the motor frequency to the instability point using the modified PI parameters fail, manual intervention is required. Record the data from previous attempts to autonomously increase the motor frequency to the instability point using the modified PI parameters for comparison by the debugging personnel. Once the motor frequency reaches a stable point after autonomous or manual debugging, record the motor's control parameters and corresponding runaway data in the historical problem model. Use the PI parameter at which the motor frequency reaches a stable point as the PI parameter in the historical problem model that most closely resembles the current instability characteristics of the motor's three-phase current signal waveform. Record both stable and unstable PI parameters.

[0115] Compared to related solutions where parameters are adjusted manually based on experience, the solution of this invention, based on historical problem models, has a higher initial debugging accuracy and a much faster response than manual debugging. Even if autonomous debugging fails, debugging records can be retained, allowing debugging personnel to use data to determine which direction to adjust for the most significant effect, thus improving debugging efficiency. It also has the ability to be continuously updated, resulting in increasingly higher accuracy.

[0116] In the solution of this invention, by having the motor control system record the unstable current waveform of the three-phase power output from the frequency converter and the corresponding PI parameters into the historical problem model, the motor control system has the ability to optimize parameters, which can provide experience reference for subsequent debugging and achieve the effect of improving the intelligence level of the motor control system.

[0117] Alternatively, in step S120, determining the corrected PI parameter of the motor based on the motor's current signal further includes: determining the corrected PI parameter of the motor based on a preset fuzzy rule library.

[0118] The following is combined with Figure 7 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining the corrected PI parameter of the motor according to a preset fuzzy rule library. The specific process of determining the corrected PI parameter of the motor according to the preset fuzzy rule library in step S120 is further explained, including steps S710 to S730.

[0119] Step S710: Based on the current signal of the motor, determine the parameters used to characterize the current waveform instability of the motor, and denot them as the current waveform instability parameters of the motor.

[0120] Step S720: Based on the set instability parameter and set IP parameter change rules in the preset fuzzy rule library, determine the set IP parameter change rule corresponding to the set instability parameter that is the same as the current waveform instability parameter of the motor in the preset fuzzy rule library as the IP parameter change rule corresponding to the current waveform instability parameter of the motor.

[0121] Step S730: According to the IP parameter change rule corresponding to the current waveform instability parameter of the motor, the current IP parameter of the motor is corrected to obtain the corrected PI parameter of the motor.

[0122] In some alternative embodiments, fuzzy control algorithms can be introduced to optimize the PI parameter adjustment process: During the adaptive adjustment phase of the PI parameters, a fuzzy logic control algorithm is introduced, using the current instability characteristics of the motor's three-phase current waveform (such as THD, WDF trends, frequency points, and load conditions) as input variables, and outputting the adjustment coefficients of the PI parameters. Through a preset fuzzy rule base (e.g., "if THD increases and WDF is large, increase the integral coefficient Ki and slightly decrease the proportional coefficient Kp"), fine-tuning of the PI parameters is achieved, improving the robustness and adaptability of the motor control system under complex operating conditions. The fuzzy control strategy can be continuously optimized based on field debugging data, enhancing the self-learning capability of the motor control system.

[0123] In the scheme of this invention, the motor control system has a certain degree of autonomous judgment capability in the variable frequency debugging mode of the motor (such as a permanent magnet synchronous motor). It can autonomously control the motor's acceleration or deceleration or frequency adjustment based on the motor current. After detecting that the three-phase power output from the inverter shows current waveform instability and the motor frequency is reduced, the PI parameters can be intelligently modified according to the historical problem model, and the motor frequency can be increased to the instability point. If the current waveform instability of the three-phase power output from the inverter is still detected after multiple attempts to increase the motor frequency to the instability point, the attempt to increase the motor frequency to the instability point is stopped, and manual intervention is awaited. In the scheme of this invention, the phenomenon of current waveform instability in the three-phase power output from the inverter and the corresponding correct PI parameters are recorded in the historical problem model for subsequent parameter optimization and learning.

[0124] In this invention, a continuously evolving historical fault model library is established: after multiple failed attempts, the motor control system stops trying and waits for manual intervention, recording the instability of the three-phase current waveform at the inverter output and the corresponding PI parameters in the historical problem model. The motor control system intelligently modifies the PI parameters and attempts to increase the frequency based on the historical problem model. In this way, the filtering algorithm based on model predictive control adjusts the filtering parameters, continuously optimizing and adjusting them; by optimizing the design of the prediction time domain and control time domain, computational complexity can be reduced while ensuring control performance, making it suitable for real-time applications.

[0125] The technical solution of this embodiment addresses the problem of unstable three-phase current waveforms in a motor during frequency conversion commissioning (i.e., instability in the three-phase current waveform of the motor or instability in the three-phase current waveform output by the frequency converter). During the start-up of the motor frequency conversion commissioning, the current signal of the motor is acquired. After confirming the occurrence of current waveform instability and controlling the motor to operate at a lower frequency, the corrected PI parameters of the motor are determined based on the current signal. These corrected PI parameters are applied to the control loop of the motor's control system, and an attempt is made to increase the motor frequency to the frequency before the motor's lower frequency operation. Therefore, by first controlling the motor to reduce its frequency after the three-phase current waveform becomes unstable, and then adjusting the PI parameters to control the motor to increase its frequency, commissioning time and the risk of equipment damage are reduced, improving commissioning efficiency and motor stability. This frequency converter involves the manufacturing of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0126] Specifically, in the solution of this invention, addressing the problem of unstable three-phase current waveforms of the motor (i.e., unstable current waveforms of the motor's three-phase current signals or unstable current waveforms of the inverter's output) during motor frequency conversion debugging, when the unstable current waveforms of the motor's three-phase current signals are determined based on the motor's three-phase current signals, the motor frequency is controlled to regress based on the degree of instability. After a set time (e.g., 5 seconds), a new PI parameter is determined based on the current instability characteristics of the motor's three-phase current signals to improve the current instability characteristics. The new PI parameter is applied to the control loop (e.g., speed loop and / or current loop) of the motor's control system to control the motor to attempt to increase its frequency to restore the motor's operating frequency when the current instability characteristics occur. The system continues to determine whether the current waveforms of the motor's three-phase current signals are unstable. If the number of failed attempts to increase the motor's frequency reaches a set number (e.g., 3 times), the system continues to determine whether the current waveforms of the motor's three-phase current signals are unstable. If the motor frequency is increased, the control will stop and a fault alert message will be sent. The process involves determining new PI parameters to improve the current instability characteristics based on the current waveform of the motor's three-phase current signal. This can be achieved using either a historical temperature database method or a fuzzy rule base method. The historical temperature database method uses the most effective PI parameters for improving historical instability characteristics corresponding to the motor's three-phase current waveform from a historical problem database to determine the new PI parameters corresponding to the current instability characteristics of the motor's three-phase current signal. The fuzzy rule base method adjusts the current PI parameters according to the magnitude of the current instability characteristics of the motor's three-phase current waveform to obtain new PI parameters. Therefore, by first controlling the motor to reduce its frequency after the three-phase current waveform becomes unstable, and then adjusting the PI parameters to control the motor to increase its frequency, debugging time and equipment damage risk are reduced, improving debugging efficiency and motor stability. This frequency converter involves the manufacturing of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0127] According to an embodiment of the present invention, a motor control device corresponding to the motor control method is also provided. See also Figure 8 The diagram shows a structural schematic of an embodiment of the device of the present invention. This frequency converter relates to the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules. The motor control device may include: an acquisition unit 102 and a control unit 104.

[0128] The acquisition unit 102 is configured to acquire the motor's current signal during the motor's frequency converter commissioning and startup process, specifically acquiring the three-phase current signal of the motor (i.e., the three-phase electrical signal output by the frequency converter) collected by the Hall sensor. The specific functions and processing of the acquisition unit 102 are described in step S110.

[0129] The control unit 104 is configured to determine the corrected PI parameters of the motor based on the motor's current signal after determining that the motor's current waveform is unstable and controlling the motor to operate at a reversible frequency. The specific functions and processing of this control unit 104 are described in step S120.

[0130] The control unit 104 is further configured to apply the corrected PI parameters of the motor to the control loop of the motor's control system, and attempt to raise the frequency of the motor to the frequency before it was operated at the regressed frequency. The specific functions and processing of this control unit 104 are further described in step S130.

[0131] In the present invention, during the frequency conversion debugging and startup process of the motor, the current signal of the motor is acquired. After determining that the current waveform of the motor is unstable and controlling the motor to operate at a lower frequency, the corrected PI parameter of the motor is determined based on the current signal. The corrected PI parameter of the motor is applied to the control loop of the motor control system, and an attempt is made to increase the frequency of the motor to the frequency before the motor operates at the lower frequency. Thus, by first controlling the motor to reduce the frequency after the three-phase current waveform of the motor becomes unstable, and then adjusting the PI parameter to control the motor to increase the frequency, debugging time and equipment damage risk are reduced, and debugging efficiency and motor stability are improved.

[0132] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0133] According to an embodiment of the present invention, a frequency converter corresponding to a motor control device is also provided. This frequency converter may include the motor control device described above. The frequency converter relates to the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistor chips, and modules.

[0134] Since the processing and functions implemented by the frequency converter in this embodiment are basically the same as those in the embodiments, principles and examples of the aforementioned devices, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0135] According to an embodiment of the present invention, a motor corresponding to a motor control device is also provided. The motor may include: the motor control device described above, or the frequency converter described above. The frequency converter relates to the manufacture of power electronic components such as metal-oxide-semiconductor field-effect transistors, insulated-gate bipolar transistor chips and modules.

[0136] Since the processing and functions implemented by the motor in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0137] According to an embodiment of the present invention, a computer program product corresponding to the motor control method is also provided, including a computer program that, when executed by a processor, implements the steps of the motor control method described above.

[0138] Since the processing and functions implemented by the product in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0139] According to an embodiment of the present invention, a storage medium corresponding to a motor control method is also provided, the storage medium including a stored program, wherein, when the program is executed, the device where the storage medium is located executes the steps of the motor control method described above.

[0140] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0141] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0142] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for controlling an electric motor, characterized in that, include: During the frequency converter debugging and startup process of the motor, the current signal of the motor is acquired; After determining that the motor current waveform is unstable and controlling the motor to operate at the back frequency, the corrected PI parameters of the motor are determined based on the motor current signal. The corrected PI parameters of the motor are applied to the control loop of the motor's control system, and an attempt is made to increase the frequency of the motor to the frequency before it was operated at the regressed frequency.

2. The motor control method according to claim 1, characterized in that, Also includes: Based on the current signal of the motor, determine whether the current waveform of the motor is unstable; If it is determined that no current waveform instability of the motor has occurred, then the motor is controlled to continue operating at an increased frequency; If it is determined that the current waveform of the motor is unstable, the motor is controlled to operate at a reversal frequency according to the degree of the current waveform instability. After controlling the motor to run at the retraction frequency for a set time, determine whether the motor's current waveform instability has been restored based on the motor's current signal; If it is determined that the current waveform instability of the motor has been restored, then the corrected PI parameter of the motor is determined based on the current signal of the motor. If it is determined that the current waveform instability of the motor has not been recovered, the frequency of the motor is controlled to be reduced to a preset minimum frequency, and then the corrected PI parameter of the motor is determined based on the current signal of the motor.

3. The motor control method according to claim 2, characterized in that, Based on the motor's current signal, determine whether the motor's current waveform instability has occurred, including: Based on the current signal of the motor, determine the parameters used to characterize the current waveform instability of the motor; the parameters used to characterize the current waveform instability of the motor include: the total harmonic distortion rate of the current waveform of the motor, and / or determine the distortion coefficient of the current waveform of the motor. If it is determined that the total harmonic distortion rate of the motor's current waveform is greater than a preset first distortion rate threshold or the distortion coefficient of the motor's current waveform is greater than a preset first distortion coefficient threshold, then it is determined that the motor's current waveform is unstable.

4. The motor control method according to claim 2 or 3, characterized in that, The degree of instability of the motor's current waveform is characterized by the total harmonic distortion rate and / or the distortion coefficient of the motor's current waveform. Based on the degree of instability in the motor's current waveform, the reversal frequency of the motor is controlled, including: If it is determined that the total harmonic distortion rate of the current waveform of the motor is greater than a preset first distortion rate threshold and less than a preset second distortion rate threshold, and it is determined that the distortion coefficient of the current waveform of the motor is greater than a preset first distortion coefficient threshold and less than a preset second distortion coefficient threshold, then the motor is controlled to run at a preset first frequency. If it is determined that the total harmonic distortion rate of the motor's current waveform is greater than or equal to a preset second distortion rate threshold and less than a preset third distortion rate threshold, and it is determined that the distortion coefficient of the motor's current waveform is greater than or equal to a preset second distortion coefficient threshold and less than a preset third distortion coefficient threshold, then the motor is controlled to run at a preset second frequency; the preset second frequency is greater than the preset first frequency. If it is determined that the total harmonic distortion rate of the motor's current waveform is greater than or equal to a preset third distortion rate threshold, and it is determined that the distortion coefficient of the motor's current waveform is greater than or equal to a preset third distortion coefficient threshold, then the motor is controlled to return to a preset third frequency; the preset third frequency is greater than the preset second frequency.

5. The motor control method according to any one of claims 1 to 4, characterized in that, Also includes: After attempting to increase the frequency of the motor to the frequency before it was running at the reverting frequency, the system continues to determine whether the current waveform of the motor is unstable based on the current signal of the motor. If, after attempting to increase the frequency of the motor to the frequency before it was previously operated at the reverting frequency, it is determined that no current waveform instability of the motor has occurred, then the motor is controlled to continue operating at the increased frequency. Subsequently, the current signal of the motor is used to determine whether current waveform instability of the motor has occurred. It records the current instability parameters of the motor when the current waveform of the motor becomes unstable before attempting to increase the frequency of the motor to the frequency before the motor returns to the operating frequency, and the PI parameters when the current waveform of the motor does not become unstable after attempting to increase the frequency of the motor to the frequency before the motor returns to the operating frequency. In this way, a correspondence between the set instability parameters and the set PI parameters is established to update the preset historical fault database. If, after attempting to increase the frequency of the motor to the frequency before it was operated at the motor's reversal frequency, it is still determined that the current waveform of the motor is unstable, then the frequency of the motor is controlled to be reduced to the frequency before it was operated at the motor's reversal frequency. The current instability parameter and the current PI parameter are recorded when the current waveform of the motor is still unstable after attempting to increase the frequency of the motor to the frequency before it was operated at the motor's reversal frequency. The number of times the attempt to increase the frequency of the motor to the frequency before the motor reverts to operation is failed is incremented by 1 to obtain the cumulative number of failed attempts to increase the frequency of the motor to the frequency before the motor reverts to operation.

6. The motor control method according to claim 5, characterized in that, Also includes: Determine whether the cumulative number of failed attempts to raise the motor frequency to the frequency before the motor reverts to operation has reached a set threshold. If it is determined that the cumulative number of failed attempts to increase the frequency of the motor to the frequency before the motor reverts to operation has reached a set threshold, then the attempts to increase the frequency of the motor to the frequency before the motor reverts to operation will stop, and a reminder message and a record message will be issued indicating the failure of the attempts to increase the frequency of the motor to the frequency before the motor reverts to operation. If it is determined that the cumulative number of failed attempts to raise the motor frequency to the frequency before the motor reverts to its previous operating frequency has not reached the set threshold, then the corrected PI parameters of the motor are re-determined based on the motor's current signal.

7. The motor control method according to any one of claims 1 to 6, characterized in that, in, Based on the current signal of the motor, determine the corrected PI parameters of the motor, including: Based on the current signal of the motor, determine the parameters used to characterize the current waveform instability of the motor, and denot them as the current waveform instability parameters of the motor. Based on the correspondence between the set instability parameters and the set IP parameters in the preset historical fault database, the set IP parameters corresponding to the set instability parameters that are the same as the current waveform instability parameters of the motor in the correspondence are determined as the IP parameters corresponding to the current waveform instability parameters of the motor. If there is only one IP parameter corresponding to the current waveform instability parameter of the motor, then the IP parameter corresponding to the current waveform instability parameter of the motor shall be used as the corrected PI parameter of the motor. If there are two or more IP parameters corresponding to the current waveform instability parameters of the motor, then the weighted average of the two or more IP parameters corresponding to the current waveform instability parameters of the motor shall be used as the corrected PI parameter of the motor. or, Determining the corrected PI parameters of the motor based on the motor's current signal further includes: Based on the current signal of the motor, determine the parameters used to characterize the current waveform instability of the motor, and denot them as the current waveform instability parameters of the motor. Based on the instability parameter and IP parameter change rules set in the preset fuzzy rule library, the IP parameter change rules corresponding to the instability parameter that is the same as the current waveform instability parameter of the motor in the preset fuzzy rule library are determined as the IP parameter change rules corresponding to the current waveform instability parameter of the motor. Based on the IP parameter change rules corresponding to the current waveform instability parameters of the motor, the current IP parameters of the motor are corrected to obtain the corrected PI parameters of the motor.

8. A control device for an electric motor, characterized in that, include: The acquisition unit is configured to acquire the current signal of the motor; The control unit is configured to determine the corrected PI parameters of the motor based on the motor's current signal after determining that the motor's current waveform is unstable and controlling the motor to operate at a back-off frequency. The control unit is also configured to apply the corrected PI parameters of the motor to the control loop of the motor's control system and attempt to raise the frequency of the motor to the frequency before it was operated at the regressed frequency.

9. A frequency converter, characterized in that, include: The motor control device as described in claim 8.

10. An electric motor, characterized in that, include: The motor control device as described in claim 8, or the frequency converter as described in claim 9.

11. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the motor control method according to any one of claims 1 to 7.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the motor control method according to any one of claims 1 to 7.

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