A control method, device and system applied to a permanent magnet synchronous motor

Abstract

The application relates to the technical field of motor control, in particular to a control method, device and system applied to a permanent magnet synchronous motor. The application obtains pulsation stability according to the difference between electromagnetic data in a preset time window of an adjacent reference time before the current time and the difference between electromagnetic data variation trends, and obtains an adjustment degree according to the duration of the electromagnetic data variation trend at the time before the current time and the abnormality degree of the electromagnetic data; according to the pulsation stability and the adjustment degree at the current time, a predicted value of the electromagnetic data at the time after the current time is obtained by using a particle filtering algorithm, and then a possible adjustment time of the current time is determined, and the inverter controls the permanent magnet synchronous motor before the possible adjustment time. The application analyzes the stability degree and the adjustment degree of the electromagnetic data at the current time to determine the possible adjustment time, controls the permanent magnet synchronous motor in advance, effectively reduces overshoot and pulsation, and improves the control effect on the permanent magnet synchronous motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, in particular to a control method, device and system applied to a permanent magnet synchronous motor. BACKGROUND

[0002] The weak magnetic capability of the permanent magnet synchronous motor is poor and the speed regulation range is small, so it is not easy to realize precise control of the motor. Controlling the permanent magnet synchronous motor can make the motor run stably, respond quickly and reduce faults.

[0003] The existing method usually uses a direct torque control method to control the motor, which does not require complex coordinate transformation, thereby reducing the dependence of the system on parameters. However, the direct torque control method is discrete in action, and the switching state changes only when the threshold is reached or exceeded, which makes the response speed of the system control circuit not fast enough, resulting in overshoot and pulsation of torque and flux linkage, and further poor control effect of the permanent magnet synchronous motor. SUMMARY

[0004] In order to solve the technical problem that the response speed of the system control circuit is slow and the control effect of the permanent magnet synchronous motor is poor, the purpose of the present application is to provide a control method, device and system applied to a permanent magnet synchronous motor, and the technical solution adopted is as follows:

[0005] In a first aspect, an embodiment of the present application provides a control method applied to a permanent magnet synchronous motor, which comprises:

[0006] Obtaining electromagnetic data of the permanent magnet synchronous motor at each time in an analysis time period; the last time in the analysis time period is the current time;

[0007] According to the difference between the electromagnetic data in a preset time window of the adjacent reference time before the current time and the difference between the electromagnetic data change trend, obtaining the pulsation stability of the electromagnetic data at the current time; according to the duration of the electromagnetic data change trend before the current time and the abnormal degree of the electromagnetic data at the current time, obtaining the adjustment degree of the electromagnetic data at the current time;

[0008] According to the pulsation stability and the adjustment degree of the electromagnetic data at the current time, using a particle filtering algorithm to obtain the predicted value of the electromagnetic data at the time after the current time, determining the possible adjustment time of the current time, and adjusting the inverter to control the permanent magnet synchronous motor before the possible adjustment time.

[0009] Further, the pulsation stability of the electromagnetic data at the current time is obtained, which comprises:

[0010] Optionally, a time point in the analysis time period is recorded as an example time point, electromagnetic data of all time points in a preset time window of the example time point is arranged in time sequence to obtain an electromagnetic sequence of the example time point; a first-order difference sequence of the electromagnetic sequence is obtained, and a number of sign changes of adjacent two elements in the first-order difference sequence is taken as a pulsation number of the example time point;

[0011] A mean value of electromagnetic data of all time points in a preset time window of the example time point is calculated as a neighborhood electromagnetic central value of the example time point;

[0012] According to a difference between the pulsation numbers of the two adjacent reference time points of the current time point and a difference between the neighborhood electromagnetic central values, a pulsation stability of electromagnetic data of the current time point is obtained.

[0013] Further, the obtaining of the pulsation stability of the electromagnetic data of the current time point according to the difference between the pulsation numbers of the two adjacent reference time points of the current time point and the difference between the neighborhood electromagnetic central values comprises:

[0014] The cumulative sum of absolute values of the difference values of the pulsation numbers of all the two adjacent reference time points of the current time point and the cumulative sum of absolute values of the difference values of the neighborhood electromagnetic central values are taken as a pulsation difference value and an electromagnetic difference value of the current time point, respectively;

[0015] A product of the pulsation difference value and the electromagnetic difference value is negatively correlated to obtain the pulsation stability of the electromagnetic data of the current time point.

[0016] Further, the obtaining of the adjustment degree of the electromagnetic data of the current time point comprises:

[0017] A trend interruption time point of the current time point is selected from time points before the current time point in the analysis time period, electromagnetic data of the trend interruption time point are all greater than or less than electromagnetic data of adjacent previous and subsequent time points of the trend interruption time point; a time interval between the current time point and the trend interruption time point closest to the current time point is taken as an electromagnetic trend duration of the current time point;

[0018] A mean value of electromagnetic data of the rest of time points in a preset time window of the current time point except the current time point is calculated as a local electromagnetic central value of the current time point;

[0019] According to a difference between the local electromagnetic central value and the neighborhood electromagnetic central value and the electromagnetic trend duration, an adjustment degree of the electromagnetic data of the current time point is obtained; the difference and the electromagnetic trend duration are in positive correlation with the adjustment degree.

[0020] Further, the pulsation stability and the adjustment degree of the electromagnetic data at the current time are used to obtain a predicted value of the electromagnetic data at a time after the current time by using a particle filtering algorithm, and a possible adjustment time of the current time is determined, comprising:

[0021] The next time of the current time is a predicted time, a plurality of particles are preset at a first reference time of the predicted time, and a state value of the electromagnetic data of each particle at the predicted time is obtained by using the particle filtering algorithm.

[0022] A weighted average value of the state value and the maximum weight of the electromagnetic data of all particles at the predicted time is obtained as the predicted value of the electromagnetic data at the predicted time, and the predicted value of the electromagnetic data at a time after the current time is obtained.

[0023] A target time after the current time is determined, the target time is a plurality of times away from the current time, if the predicted value of the electromagnetic data at a time between the current time and the target time reaches a preset threshold value, the first time reaching the preset threshold value is recorded as the possible adjustment time of the current time, and if the predicted value of the electromagnetic data at all times between the current time and the target time does not reach the preset threshold value, the target time is recorded as the possible adjustment time of the current time.

[0024] Further, the maximum weight of the electromagnetic data of each particle at the predicted time is obtained, comprising:

[0025] If the pulsation stability at the current time is greater than or equal to the adjustment degree, a negative correlation mapping is performed on the absolute value of the difference between the mean value of the state value of the electromagnetic data of all particles at the predicted time and the state value of the electromagnetic data of each particle at the predicted time, and a product of the mapping result and the pulsation stability at the current time is taken as the initial weight of the electromagnetic data of each particle at the predicted time.

[0026] If the pulsation stability at the current time is less than the adjustment degree, an electromagnetic expected value at the predicted time is obtained according to the change trend of the electromagnetic data at the reference time of the predicted time, a negative correlation mapping is performed on the absolute value of the difference between the state value of the electromagnetic data of each particle at the predicted time and the electromagnetic expected value, and a product of the mapping result and the adjustment degree at the current time is taken as the initial weight of the electromagnetic data of each particle at the predicted time.

[0027] The proportion of the initial weight of the electromagnetic data of each particle at the predicted time in the total sum of the initial weights of the electromagnetic data of all particles at the predicted time is taken as the maximum weight of the electromagnetic data of each particle at the predicted time.

[0028] Further, the method further comprises:

[0029] A two-dimensional coordinate system is established with time as the horizontal axis and electromagnetic data as the vertical axis, electromagnetic data of all reference time points of the prediction time point is mapped into the two-dimensional coordinate system to obtain coordinate points corresponding to the reference time points, linear fitting is performed on all coordinate points in the two-dimensional coordinate system to obtain a fitting straight line, and a vertical coordinate of a corresponding point of the prediction time point on the fitting straight line is taken as the electromagnetic expected value of the prediction time point.

[0030] Further, the reference time points before the current time point are adjacent 5 time points.

[0031] In a second aspect, an embodiment of the application provides a control system applied to a permanent magnet synchronous motor, which comprises:

[0032] A data acquisition module is configured to acquire electromagnetic data of each time point of the permanent magnet synchronous motor in an analysis time period, and a last time point in the analysis time period is a current time point.

[0033] A stable regulation analysis module is configured to acquire a pulsation stability of electromagnetic data of the current time point according to a difference between electromagnetic data in a preset time window of adjacent reference time points before the current time point and a difference between electromagnetic data change trends, and acquire a regulation degree of electromagnetic data of the current time point according to a duration of the electromagnetic data change trends before the current time point and an abnormal degree of the electromagnetic data of the current time point.

[0034] A motor control module is configured to acquire a prediction value of electromagnetic data of a time point after the current time point by using a particle filtering algorithm according to the pulsation stability and the regulation degree of the electromagnetic data of the current time point, determine a possible adjustment time point of the current time point, and adjust the inverter to control the permanent magnet synchronous motor before the possible adjustment time point.

[0035] In a third aspect, another embodiment of the application provides a control device applied to a permanent magnet synchronous motor, which comprises a processor, and the processor implements steps of a control method applied to the permanent magnet synchronous motor when executed.

[0036] The application has the following beneficial effects:

[0037] In the embodiment of the present application, the difference of the electromagnetic data change trend of the adjacent reference time of the current time reflects the frequency of the pulsation times, the difference of the electromagnetic data in the preset time window of the adjacent reference time reflects the possibility of the current time in the rising and falling change state, both of which reflect the stability degree of the electromagnetic data of the current time, and the pulsation stability degree is obtained; the continuous time length of the electromagnetic data change trend of the previous time of each time reflects the possibility of the electromagnetic data of each time exceeding the normal fluctuation range, the greater the abnormal degree of the electromagnetic data, the greater the adjustment degree required, and the adjustment degree required by the electromagnetic data of each time is analyzed by comprehensively analyzing the adjustment degree, and the adjustment degree is obtained; according to the pulsation stability degree and the adjustment degree, the predicted value of the electromagnetic data of the electromagnetic data of the time after the current time is predicted by combining the particle filtering algorithm, the part excessively affected by the pulsation is ignored, the accurate estimation of the system state is increased, and in the case that the electromagnetic data change trend is obvious, the prediction error can be eliminated and the estimation accuracy can be improved, and the accuracy and stability of the predicted value of the electromagnetic data are improved; the possible adjustment time is obtained by analyzing the case that the predicted value exceeds the threshold, and the inverter is adjusted in advance before the possible adjustment time, so that the overshoot and pulsation of the possible adjustment time caused by the slow response speed of the system control circuit are effectively solved, and the control effect of the permanent magnet synchronous motor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art and the advantages thereof, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Figure 1 A step flow chart of a control method applied to a permanent magnet synchronous motor provided by an embodiment of the present application;

[0040] Figure 2 A step flow chart of a possible adjustment time acquisition method provided by an embodiment of the present application;

[0041] Figure 3 A system structure diagram of a control system applied to a permanent magnet synchronous motor provided by an embodiment of the present application;

[0042] Figure 4 A computer device schematic diagram of a control device applied to a permanent magnet synchronous motor provided by an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to further clarify the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the following describes in detail the specific implementation, structure, features and effects of the control method, device and system applied to the permanent magnet synchronous motor according to the present application, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0045] The specific scheme of the control method, device and system applied to the permanent magnet synchronous motor provided by the present application is described in detail below in combination with the accompanying drawings.

[0046] Embodiment 1:

[0047] The present application proposes a control method applied to a permanent magnet synchronous motor, please refer to Figure 1 which shows a step flowchart of a control method applied to a permanent magnet synchronous motor according to one embodiment of the present application, which method comprises:

[0048] Step S1: Obtain the electromagnetic data of the permanent magnet synchronous motor at each time within the analysis time period; the last time within the analysis time period is the current time.

[0049] The electromagnetic torque equation and flux equation are disclosed in the paper titled "Research on Vector Control and Direct Torque Control Strategy Based on Permanent Magnet Synchronous Motor" by Li Rui, Zhao Yihai and Wang Jianpo, which is published in the stator flux orientation section of 1.2DTC. Obtain the number of pole pairs of the permanent magnet synchronous motor, and obtain the direct-axis inductance and quadrature-axis inductance of the permanent magnet synchronous motor at each time within the analysis time period through the direct transient method. Measure the stator flux, torque angle and stator voltage of the permanent magnet synchronous motor at each time during operation. Based on the above data, use the electromagnetic torque equation and flux equation disclosed in the paper to calculate the electromagnetic torque and flux at each time within the analysis time period; the electromagnetic torque and flux are referred to as electromagnetic data.

[0050] In one implementation manner of the embodiment of the present application, the time interval between the two adjacent times is set to 1 millisecond.

[0051] It should be noted that the starting time of the analysis time period is the time when the permanent magnet synchronous motor starts to operate, and the current time is the last time within the analysis time period.

[0052] Step S2: obtaining the pulsation stability of the electromagnetic data at the current time according to the difference between the electromagnetic data in the preset time window of the adjacent reference time before the current time and the difference between the electromagnetic data variation trends; obtaining the adjustment degree of the electromagnetic data at the current time according to the duration of the electromagnetic data variation trend at the time before the current time and the abnormal degree of the electromagnetic data at the current time.

[0053] The difference between the electromagnetic data variation trends of the adjacent reference times at the current time reflects the frequency of the pulsation times, and further presents the stability degree of the electromagnetic data at the current time; the difference between the electromagnetic data in the preset time window of the adjacent reference times at the current time reflects the possibility of the electromagnetic data at the current time in the rising and falling variation state, and the smaller the stability degree of the electromagnetic data in the rising and falling variation state is, the smaller the pulsation stability is obtained by comprehensively analyzing the stability degree of the electromagnetic data at the current time.

[0054] In one implementation manner of the embodiment of the present application, the adjacent 5 times before each time in the analysis time period are taken as the reference times of each time, wherein 5 can be replaced by a positive integer greater than or equal to 2.

[0055] In one implementation manner of the embodiment of the present application, the last time in the preset time window of each time is located, and the length of the preset time window is set to 10.

[0056] Preferably, in some possible implementation manners of the embodiment of the present application, the obtaining method of the pulsation stability comprises: taking a time in the analysis time period as an example time, arranging the electromagnetic data of all times in the preset time window of the example time in time sequence to obtain an electromagnetic sequence of the example time; obtaining a first-order difference sequence of the electromagnetic sequence, taking the number of times of the sign change of adjacent two elements in the first-order difference sequence as the pulsation times of the example time; calculating the mean value of the electromagnetic data of all times in the preset time window of the example time as the neighborhood electromagnetic central value of the example time; and obtaining the pulsation stability of the electromagnetic data at the current time according to the difference between the pulsation times of the adjacent two reference times at the current time and the difference between the neighborhood electromagnetic central values.

[0057] The pulsation times reflect the number of times of the change of the distribution trend of the electromagnetic data in the preset time window of each time; the greater the difference between the pulsation times of the adjacent reference times at the current time is, the more frequent the pulsation times change, the more unstable the electromagnetic data at the current time is, the lower the stability degree is, and the smaller the pulsation stability of the electromagnetic data at the current time is. The neighborhood electromagnetic central value reflects the overall level of the electromagnetic data in the preset time window of each time; the greater the difference between the neighborhood electromagnetic central values of the adjacent reference times at the current time is, the greater the possibility of the electromagnetic data at the reference times at the current time in the rising and falling variation state is, the smaller the stability degree of the electromagnetic data at the current time is, and the smaller the pulsation stability is.

[0058] In a specific implementation manner of the embodiment of the present application, the specific acquisition method of the pulsation stability is as follows: the cumulative sum of the absolute value of the difference of the pulsation frequency of all adjacent two reference time points of the current time point, and the cumulative sum of the absolute value of the difference of the neighborhood electromagnetic concentration value are taken as the pulsation difference value and the electromagnetic difference value of the current time point in turn; the product of the pulsation difference value and the electromagnetic difference value is negatively correlated to obtain the pulsation stability of the electromagnetic data of the current time point. In a specific implementation manner of the embodiment of the present application, the pulsation stability of the electromagnetic data of the current time point is which is expressed by a formula as follows:

[0059] In the formula, d is the current time point; A is the total number of reference time points of the current time point; N is the pulsation frequency of the a-th reference time point of the current time point; N+1 is the pulsation frequency of the a+1-th reference time point of the current time point; C is the neighborhood electromagnetic concentration value of the a-th reference time point of the current time point; C+1 is the neighborhood electromagnetic concentration value of the a+1-th reference time point of the current time point; D is the pulsation difference value of the current time point; E is the electromagnetic difference value of the current time point; abs is the absolute value function; and exp is the exponential function with the natural constant as the base number. In the formula, the exponential function with the natural constant as the base number is used for negative correlation mapping. In other possible implementation manners of the embodiment of the present application, other negative correlation mappings can also be selected, which are all the technical means familiar to those skilled in the art, and thus will not be described and limited herein.

[0060] The duration of the electromagnetic data change trend of each time point before the time point reflects the possibility of the electromagnetic data of each time point exceeding the normal fluctuation range. The greater the possibility is, the greater the adjustment degree of the electromagnetic data is, and the greater the abnormal degree of the electromagnetic data is, the greater the adjustment degree required is. The adjustment degree required for the electromagnetic data of each time point is obtained by comprehensively analyzing the adjustment degree required for the electromagnetic data of each time point.

[0061] Preferably, in some possible implementation manners of the embodiment of the present application, the acquisition method of the adjustment degree comprises: selecting the trend interruption time point of the current time point from the time points before the current time point in the analysis time period, the electromagnetic data of the trend interruption time point are all greater than or less than the electromagnetic data of the adjacent previous and subsequent time points; taking the time interval between the current time point and the trend interruption time point closest to the current time point as the electromagnetic trend duration of the current time point; calculating the mean value of the electromagnetic data of the remaining time points except the current time point in the preset time window of the current time point as the local electromagnetic concentration value of the current time point; and acquiring the adjustment degree of the electromagnetic data of the current time point according to the difference between the local electromagnetic concentration value and the neighborhood electromagnetic concentration value and the electromagnetic trend duration.

[0062] ​​​​​​The trend interruption moment is a moment when the electromagnetic data distribution trend at a moment before the current moment changes, and the trend of the electromagnetic data between the current moment and the trend interruption moment closest to the current moment is the same; the greater the electromagnetic trend duration is, the longer the time that the electromagnetic data at the current moment maintains the rising or falling trend is, the greater the possibility that the electromagnetic data at the current moment exceeds the normal fluctuation range is, the greater the adjustment degree required by the electromagnetic data at the current moment is, and the greater the adjustment degree is. The greater the difference between the overall level of the electromagnetic data at the current moment and the electromagnetic data not containing the current moment in the preset time window of the current moment is, the greater the abnormality degree of the electromagnetic data at the current moment is, the greater the adjustment degree required by the electromagnetic data at the current moment is, and the greater the adjustment degree is. Therefore, the difference between the local electromagnetic concentration value and the neighborhood electromagnetic concentration value and the electromagnetic trend duration are positively correlated with the adjustment degree.

[0063] In a specific implementation manner of the embodiment of the application, the adjustment degree of the electromagnetic data at the current moment is determined according to the following formula:

[0064] In the formula, d is the current moment; is the electromagnetic trend duration at the current moment; is the local electromagnetic concentration value at the current moment; is the neighborhood electromagnetic concentration value at the current moment; is an absolute value function; and Norm is a normalization function.

[0065] Step S3: acquiring a predicted value of electromagnetic data at a moment after the current moment by using a particle filtering algorithm according to the pulsation stability and the adjustment degree of the electromagnetic data at the current moment, determining a possible adjustment moment of the current moment, and adjusting the inverter control permanent magnet synchronous motor before the possible adjustment moment.

[0066] According to the pulsation stability and the adjustment degree, and in combination with the particle filtering algorithm, the predicted value of the electromagnetic data of the electromagnetic data at the moment after the current moment can be predicted, the part excessively affected by the pulsation can be ignored, the accurate estimation of the system state is increased, the prediction error can be eliminated and the estimation precision can be improved in the case that the electromagnetic data change trend is obvious, and the accuracy and stability of the predicted value of the electromagnetic data are improved.

[0067] Referring to Figure 2 , a step flowchart of a possible adjustment moment acquisition method of a current moment provided by an embodiment of the application is shown, and the method comprises the following steps:

[0068] ​Step S310: the next time of the current time is a prediction time; preset a plurality of particles at the first reference time of the prediction time, and obtain the state value of the electromagnetic data of each particle at the prediction time by using the particle filter algorithm; and obtain the minimum weight of the electromagnetic data of each particle at the prediction time according to the state value of the electromagnetic data of each particle at the prediction time and the pulsation stability and the adjustment degree at the current time.

[0069] In one implementation form of the embodiment of the application, the number of the preset particles at the first reference time of the prediction time is set to 100.

[0070] In one implementation form of the embodiment of the application, the particles are uniformly distributed at the first reference time of the prediction time, the prediction domain of the electromagnetic torque is Newton·m, the prediction domain of the magnetic chain is Weber, the state value of the electromagnetic data of the mth particle at the first reference time of the prediction time is expressed by a formula as follows: , is the minimum value of the electromagnetic data in the domain, is the maximum value of the electromagnetic data in the domain, is the minimum value of the electromagnetic data in the domain, is the maximum value of the electromagnetic data in the domain, d+1 is the first reference time of the prediction time.

[0071] The particle filter algorithm depends on the Bayesian filter framework, and the state of the particles is recursively predicted, i.e. the state at the next time is predicted from the state at the last time, to gradually update the state estimation of the system. Each particle predicts the state value of the electromagnetic data at the next time from the state value of the electromagnetic data at the last time according to the dynamic model of the system such as the physical model and the control model, recursively, to obtain the state value of the electromagnetic data of each particle at the prediction time. The prediction of the state of each particle at the continuous time is a known technology in the particle filter algorithm, and will not be described here.

[0072] ​Preferably, in some possible implementation manners of the embodiments of the present application, the method for obtaining the final weight comprises: if the fluctuation stability of the current time is greater than or equal to the adjustment degree, performing a negative correlation mapping on the absolute value of the difference between the mean value of the state value of the electromagnetic data of all particles at the predicted time and the state value of the electromagnetic data of each particle at the predicted time, and taking the product of the mapping result and the fluctuation stability of the current time as the initial weight of the electromagnetic data of each particle at the predicted time; if the fluctuation stability of the current time is less than the adjustment degree, obtaining an electromagnetic expected value at the predicted time according to the change trend of the electromagnetic data at the reference time of the predicted time; performing a negative correlation mapping on the absolute value of the difference between the state value of the electromagnetic data of each particle at the predicted time and the electromagnetic expected value, and taking the product of the mapping result and the adjustment degree of the current time as the initial weight of the electromagnetic data of each particle at the predicted time; and taking the proportion of the initial weight of the electromagnetic data of each particle at the predicted time in the total sum of the initial weights of the electromagnetic data of all particles at the predicted time as the final weight of the electromagnetic data of each particle at the predicted time.

[0073] Since the electromagnetic data trends of the current time and the predicted time are relatively close, the fluctuation stability of the electromagnetic data of the current time and the adjustment degree are used to represent the fluctuation stability degree and the adjustment degree of the electromagnetic data of the predicted time.

[0074] If the fluctuation stability of the electromagnetic data of the current time is greater than or equal to the adjustment degree, it indicates that the electromagnetic data is in a stable state, and in order to reduce the fluctuation amplitude, the state value of the electromagnetic data of each particle at the predicted time should have a greater weight in the case that the electromagnetic data at the predicted time is more stable, i.e., the fluctuation stability is greater, and the difference between the mean value of the state value of the electromagnetic data of all particles at the predicted time is greater. Through the above operation, the particle filter algorithm can more accurately track the average electromagnetic data of the system, ignore the part excessively affected by the fluctuation, and increase the accurate estimation of the average state of the system.

[0075] If the fluctuation stability of the electromagnetic data of the current time is less than the adjustment degree, it indicates that the electromagnetic data at the predicted time is in a rising and falling state, and the greater the adjustment degree required at the predicted time, the greater the electromagnetic data has begun to rise or fall. Through the change trend of the electromagnetic data at the reference time of the predicted time, the expected value of the electromagnetic data at the predicted time, i.e., the electromagnetic expected value, is obtained, and the state value of the particle at the predicted time is more close to the electromagnetic expected value, and the weight of the electromagnetic data of the particle at the predicted time should be greater; meanwhile, the weight of the electromagnetic data of the particle whose state value is more close to the rising and falling change of the electromagnetic data, i.e., the adjustment degree of the electromagnetic data of the current time, is greater, and the weight of the particle is greater. Through the above operation, the particle filter can be guided to converge to the correct trajectory more quickly, and the above operation is helpful to eliminate the prediction error and improve the estimation accuracy, especially when the electromagnetic data change trend is obvious.

[0076] In this embodiment of the invention, the method for obtaining the electromagnetic expected value is as follows: a two-dimensional coordinate system is established with time as the horizontal axis and electromagnetic data as the vertical axis; the electromagnetic data of all reference times at the predicted time are mapped onto the two-dimensional coordinate system to obtain the coordinate points of the corresponding reference times; linear fitting is performed on all coordinate points in the two-dimensional coordinate system to obtain the fitted line, and the vertical coordinate of the point corresponding to the predicted time on the fitted line is taken as the electromagnetic expected value of the predicted time. This embodiment uses the least squares method to perform linear fitting on the coordinate points in the two-dimensional coordinate system.

[0077] In one specific implementation of this invention, the final weight of the electromagnetic data of each particle at the prediction time is expressed by the formula:

[0078]

[0079]

[0080] In the formula, d represents the final weight of the electromagnetic data of the m-th particle at the prediction time; d is the current time, d+1 is the prediction time, i.e. the next time after the current time; M is the total number of particles. The initial weights are the electromagnetic data of the m-th particle at the prediction time. The current moment represents the pulsation stability of the electromagnetic data; The adjustment degree of the electromagnetic data at the current moment; Let m be the state value of the electromagnetic data of the m-th particle at the predicted time. The mean of the state values ​​of the electromagnetic data of all particles at the predicted time; The expected electromagnetic value at the predicted time; is an absolute value function; exp is an exponential function with the natural constant as the base.

[0081] It should be noted that the weight of each particle at each time step in the particle filter algorithm is replaced with the final weight in this scheme, while other contents remain unchanged.

[0082] Step S320: Obtain the final weighted average of the electromagnetic data of all particles at the prediction time and the state value, as the predicted value of the electromagnetic data at the prediction time; obtain the predicted value of the electromagnetic data at the time after the current time.

[0083] Predicted values ​​of electromagnetic data at the predicted time Expressed as a formula:

[0084] In the formula, M is the total number of particles; The final weight of the electromagnetic data of the m-th particle at the prediction time; Let be the state value of the electromagnetic data of the m-th particle at the predicted time.

[0085] The electromagnetic data in the step of obtaining the predicted value of the electromagnetic data at the predicted time is replaced by electromagnetic torque and magnetic chain, and the predicted value of the electromagnetic torque and the predicted value of the magnetic chain at the predicted time are sequentially obtained.

[0086] The particle filtering is continuously performed from the predicted time to the rear, and the predicted value of the electromagnetic data at each time after the current time is obtained; the method for obtaining the predicted value of the electromagnetic data at each time after the current time is the same as the method for obtaining the predicted value of the electromagnetic data at the predicted time. The difference is that the electromagnetic data and the state value of each particle at each time after the current time are used to replace the electromagnetic data and the state value of each particle at the predicted time in the process of obtaining the predicted value of the electromagnetic data at the predicted time, and other contents remain unchanged. Thus, the predicted value of the electromagnetic torque and the predicted value of the magnetic chain at a plurality of continuous times after the current time are obtained.

[0087] Step S330: determining a target time after the current time, the target time being a plurality of times away from the current time; if the predicted value of the electromagnetic data at each time between the current time and the target time reaches a preset threshold value, the first time reaching the preset threshold value is recorded as a possible adjustment time of the current time; if the predicted value of the electromagnetic data at each time between the current time and the target time does not reach the preset threshold value, the target time is recorded as the possible adjustment time of the current time.

[0088] For each time between the current time and the target time, if at least one of the predicted value of the electromagnetic torque and the predicted value of the magnetic chain at each time is greater than the corresponding preset threshold value, the time is considered to be a time reaching the preset threshold value, and the first time reaching the preset threshold value is recorded as the possible adjustment time in order to avoid excessive pulsation and adjust the permanent magnet synchronous motor as soon as possible. The predicted value of the electromagnetic torque and the predicted value of the magnetic chain at each time between the current time and the target time are all less than the corresponding preset threshold value, and the target time is recorded as the possible adjustment time in order to avoid too long calculation time. It should be noted that each time between the current time and the target time does not include the current time and the target time.

[0089] In one implementation manner of the embodiment of the application, the tenth time after the current time is recorded as the target time of the current time.

[0090] In one implementation manner of the embodiment of the application, the preset threshold value of the electromagnetic torque is set to 4 Newton meters, and the preset threshold value of the magnetic chain is set to 0.2 Weber.

[0091] The possible adjustment time point is a time point at which the voltage state of the inverter of the permanent magnet synchronous motor is adjusted at the n-th time point position before the possible adjustment time point of the current time point, overshoot and ripple of the possible adjustment time point are reduced, and the purpose of early control of the permanent magnet synchronous motor is achieved, and the speed regulation performance of the direct torque control is improved.

[0092] It should be noted that n needs to be less than the time interval between the current time point and the target time point. In an implementation manner of the embodiment of the present application, n is set to 3, and the implementer can set it by himself according to the specific situation.

[0093] In the prediction process, the permanent magnet synchronous motor is still running, and the predicted value of the electromagnetic data can be corrected by the electromagnetic data to achieve a better prediction effect. Therefore, when the electromagnetic data of the d+1 time point, that is, the prediction time point, is obtained, the d time point, that is, the current time point, is the historical time point, and the d+1 time point is the new current time point. The ripple stability and the adjustment degree of the electromagnetic data of the d+1 time point are obtained, and then the possible adjustment time point of the d+1 time point, that is, the new current time point, is obtained, and so on, so as to realize the continuous control of the permanent magnet synchronous motor. It should be noted that the method for obtaining the possible adjustment time point of the new current time point is the same as the method for obtaining the possible adjustment time point of the current time point, and will not be repeated here.

[0094] Thus far, the present application is completed.

[0095] Embodiment 2:

[0096] The present application provides a control system applied to a permanent magnet synchronous motor, please refer to Figure 3 , which shows a system structure diagram of a control system applied to a permanent magnet synchronous motor provided by an embodiment of the present application, and the system comprises:

[0097] The data acquisition module 410 is configured to obtain electromagnetic data of each time point of the permanent magnet synchronous motor in an analysis time period; and the last time point in the analysis time period is the current time point;

[0098] The stable adjustment analysis module 420 is configured to obtain the ripple stability of the electromagnetic data of the current time point according to the difference between the electromagnetic data in a preset time window of the adjacent reference time point before the current time point and the difference between the electromagnetic data change trend; and obtain the adjustment degree of the electromagnetic data of the current time point according to the continuous time length of the electromagnetic data change trend of the time point before the current time point and the abnormal degree of the electromagnetic data of the current time point.

[0099] The motor control module 430 is configured to obtain the predicted value of the electromagnetic data of the time point after the current time point by using the particle filtering algorithm according to the ripple stability and the adjustment degree of the electromagnetic data of the current time point, determine the possible adjustment time point of the current time point, and adjust the inverter to control the permanent magnet synchronous motor before the possible adjustment time point.

[0100] It should be noted that the above apparatus provided by the embodiments is only used for example to divide the above function modules, and in actual application, the above functions can be completed by different function modules according to needs, that is, the internal structure of the computer device is divided into different function modules to complete all or part of the above described functions. In addition, the control system applied to the permanent magnet synchronous motor and the control method applied to the permanent magnet synchronous motor provided by the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be repeated here.

[0101] Embodiment 3:

[0102] Figure 4 A computer device schematic diagram of a control device applied to a permanent magnet synchronous motor provided by an embodiment of the present application. For example, as shown in the figure, the computer device includes a memory 501, a processor 502, and a computer program 503 stored in the memory 501 and running on the processor 502, wherein the processor 502 executes the computer program 503, so that the computer device can execute any one of the above-mentioned control methods applied to the permanent magnet synchronous motor. Figure 4

[0103] In addition, the embodiments of the present application also protect a device, which can include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to execute the control method applied to the permanent magnet synchronous motor provided by the embodiments of the present application.

[0104] The embodiments can divide the function modules of the device according to the above method examples, for example, each function module can be corresponding, or two or more functions can be integrated in one processing module, and the integrated module can be realized in the form of hardware. It should be noted that the division of modules in the embodiments is illustrative, and is only a logical function division, and another division mode can be used in actual implementation.

[0105] It should be understood that the device provided by the embodiments is used to execute the above-mentioned control method applied to the permanent magnet synchronous motor, so as to achieve the same effect as the above-mentioned implementation method.

[0106] In the case of using integrated units, the device can include a processing module and a storage module. When the device is applied to the equipment, the processing module can be used to control and manage the actions of the equipment. The storage module can be used to support the equipment to execute the program code and the like.

[0107] ​The processing module can be a processor or a controller, which can realize or execute various exemplary logical blocks, modules and circuits contained in combination with the disclosure of the present application. The processor can also be a combination of computing functions, such as one or more microprocessor combinations, digital signal processing (Digital Signal Processing, DSP) and microprocessor combinations, etc., and the storage module can be a memory.

[0108] Embodiment 4:

[0109] The embodiment also provides a computer readable storage medium, which stores computer program codes, when the computer program codes are run on a computer, the computer executes the above-mentioned related method steps to realize the control method applied to the permanent magnet synchronous motor provided by the above-mentioned embodiment.

[0110] It should be noted that: the above-mentioned sequence of the embodiments of the present application is only for description, not representing the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or can be advantageous.

[0111] Each embodiment in the specification is described in a progressive manner, and the same and similar parts between each embodiment can be referred to each other. Each embodiment focuses on the difference from other embodiments.

[0112] The above-mentioned is only the preferred embodiment of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. within the principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method applied to a permanent magnet synchronous motor, characterized in that, The method comprises: acquiring electromagnetic data of the permanent magnet synchronous motor at each time point in an analysis time period; the last time point in the analysis time period is a current time point; acquiring pulsation stability of the electromagnetic data of the current time point according to a difference between the electromagnetic data in a preset time window of a neighboring reference time point before the current time point and a difference between electromagnetic data variation trends; acquiring an adjustment degree of the electromagnetic data of the current time point according to a duration of the electromagnetic data variation trends before the current time point and an abnormality degree of the electromagnetic data of the current time point; acquiring a predicted value of the electromagnetic data of a time point after the current time point by using a particle filtering algorithm according to the pulsation stability and the adjustment degree of the electromagnetic data of the current time point, determining a possible adjustment time point of the current time point, and adjusting an inverter controlling the permanent magnet synchronous motor before the possible adjustment time point; the acquisition of the pulsation stability of the electromagnetic data of the current time point comprises: optionally, analyzing a time point in an analysis time period as an example time point, arranging electromagnetic data of all time points in a preset time window of the example time point in time sequence to obtain an electromagnetic sequence of the example time point, and acquiring a first-order difference sequence of the electromagnetic sequence, wherein a variation frequency of signs of two adjacent elements in the first-order difference sequence is taken as a pulsation frequency of the example time point; calculating a mean value of the electromagnetic data of all time points in the preset time window of the example time point as a local electromagnetic central value of the example time point; acquiring the pulsation stability of the electromagnetic data of the current time point according to a difference between the pulsation frequencies of two neighboring reference time points before the current time point and a difference between the local electromagnetic central values; the acquisition of the pulsation stability of the electromagnetic data of the current time point according to the difference between the pulsation frequencies of the two neighboring reference time points before the current time point and the difference between the local electromagnetic central values comprises: respectively taking a cumulative sum of absolute values of the difference values of the pulsation frequencies of all neighboring reference time points of the current time point and a cumulative sum of absolute values of the difference values of the local electromagnetic central values as a pulsation difference value and an electromagnetic difference value of the current time point in sequence; performing negative correlation mapping on a product of the pulsation difference value and the electromagnetic difference value to obtain the pulsation stability of the electromagnetic data of the current time point; the acquisition of the adjustment degree of the electromagnetic data of the current time point comprises: selecting a trend interruption time point of the current time point from time points before the current time point in the analysis time period, wherein electromagnetic data of the trend interruption time point are all greater than or less than electromagnetic data of adjacent previous and subsequent time points; taking a time interval between the current time point and the trend interruption time point closest to the current time point as an electromagnetic trend duration of the current time point; calculating a mean value of electromagnetic data of the remaining time points except the current time point in a preset time window of the current time point as a local electromagnetic central value of the current time point; acquiring the adjustment degree of the electromagnetic data of the current time point according to a difference between the local electromagnetic central value and the neighborhood electromagnetic central value and the electromagnetic trend duration; the difference and the electromagnetic trend duration are in positive correlation with the adjustment degree.

2. The control method for a permanent magnet synchronous motor according to claim 1, characterized by, The pulsation stability and the adjustment degree of the electromagnetic data at the current time are used to obtain a predicted value of electromagnetic data at a time after the current time by using a particle filtering algorithm, and a possible adjustment time of the current time is determined, including: The next time of the current time is a predicted time; a plurality of particles are preset at a first reference time of the predicted time, and a state value of electromagnetic data of each particle at the predicted time is obtained by using the particle filtering algorithm; a maximum weight of electromagnetic data of each particle at the predicted time is obtained according to the state value of electromagnetic data of each particle at the predicted time and the pulsation stability and the adjustment degree of the current time; A weighted average value of the maximum weight and the state value of electromagnetic data of all particles at the predicted time is obtained as a predicted value of electromagnetic data at the predicted time; and the predicted value of electromagnetic data at the time after the current time is obtained; A target time after the current time is determined, the target time is a plurality of times away from the current time; if the predicted value of electromagnetic data at a time between the current time and the target time of the current time reaches a preset threshold value, the first time that reaches the preset threshold value is recorded as a possible adjustment time of the current time; if the predicted value of electromagnetic data at all times between the current time and the target time of the current time does not reach the preset threshold value, the target time is recorded as the possible adjustment time of the current time.

3. The control method for a permanent magnet synchronous motor according to claim 2, characterized by, The maximum weight of electromagnetic data of each particle at the predicted time includes: If the pulsation stability of the current time is greater than or equal to the adjustment degree, a negative correlation mapping is performed on a difference absolute value between a mean value of the state values of electromagnetic data of all particles at the predicted time and the state value of electromagnetic data of each particle at the predicted time, and a product of the mapping result and the pulsation stability of the current time is taken as an initial weight of electromagnetic data of each particle at the predicted time; If the pulsation stability of the current time is less than the adjustment degree, an electromagnetic expected value at the predicted time is obtained according to a change trend of electromagnetic data at a reference time of the predicted time; a negative correlation mapping is performed on a difference absolute value between the state value of electromagnetic data of each particle at the predicted time and the electromagnetic expected value, and a product of the mapping result and the adjustment degree of the current time is taken as the initial weight of electromagnetic data of each particle at the predicted time; A proportion of the initial weight of electromagnetic data of each particle at the predicted time in a total sum of the initial weights of electromagnetic data of all particles at the predicted time is taken as the maximum weight of electromagnetic data of each particle at the predicted time.

4. The control method for a permanent magnet synchronous motor according to claim 3, characterized by, The maximum weight of electromagnetic data of each particle at the predicted time includes: A two-dimensional coordinate system is established with time as the horizontal axis and electromagnetic data as the vertical axis; electromagnetic data of all reference times of the predicted time is mapped into the two-dimensional coordinate system to obtain coordinate points corresponding to the reference times; linear fitting is performed on all coordinate points in the two-dimensional coordinate system to obtain a fitting straight line, and a vertical coordinate of a corresponding point of the predicted time on the fitting straight line is taken as the electromagnetic expected value at the predicted time.

5. The control method for a permanent magnet synchronous motor according to claim 1, characterized by, The reference times of the current time are adjacent 5 times before the current time.

6. A control system for a permanent magnet synchronous motor, characterized by, The system includes: The data acquisition module is configured to acquire electromagnetic data of the permanent magnet synchronous motor at each time point in an analysis time period; a last time point in the analysis time period is a current time point; The stable adjustment analysis module is configured to acquire a pulsation stability of the electromagnetic data of the current time point according to a difference between the electromagnetic data in a preset time window of a neighboring reference time point before the current time point and a difference between a variation trend of the electromagnetic data; and acquire an adjustment degree of the electromagnetic data of the current time point according to a duration of the variation trend of the electromagnetic data before the current time point and an abnormality degree of the electromagnetic data of the current time point; The motor control module is configured to acquire a predicted value of the electromagnetic data of a time point after the current time point by using a particle filtering algorithm according to the pulsation stability and the adjustment degree of the electromagnetic data of the current time point, determine a possible adjustment time point of the current time point, and adjust the inverter to control the permanent magnet synchronous motor before the possible adjustment time point. The acquisition of the pulsation stability of the electromagnetic data of the current time point includes: An optional time point in the analysis time period is recorded as an example time point, electromagnetic data of all time points in a preset time window of the example time point are arranged in time sequence to obtain an electromagnetic sequence of the example time point, and a first-order difference sequence of the electromagnetic sequence is acquired, wherein a variation frequency of signs of two adjacent elements in the first-order difference sequence is taken as a pulsation frequency of the example time point; A mean value of the electromagnetic data of all time points in the preset time window of the example time point is calculated as a local electromagnetic central value of the example time point; The pulsation stability of the electromagnetic data of the current time point is acquired according to a difference between the pulsation frequencies of two adjacent reference time points before the current time point and a difference between the local electromagnetic central values. The acquisition of the pulsation stability of the electromagnetic data of the current time point according to the difference between the pulsation frequencies of the two adjacent reference time points before the current time point and the difference between the local electromagnetic central values includes: The absolute value of the difference of the pulsation frequencies of all two adjacent reference time points before the current time point and the absolute value of the difference of the local electromagnetic central values are respectively taken as a pulsation difference value and an electromagnetic difference value of the current time point in sequence; A product of the pulsation difference value and the electromagnetic difference value is negatively correlated to obtain the pulsation stability of the electromagnetic data of the current time point. The acquisition of the adjustment degree of the electromagnetic data of the current time point includes: A trend interruption time point of the current time point is selected from time points before the current time point in the analysis time period, the electromagnetic data of the trend interruption time point are all greater than or less than the electromagnetic data of adjacent time points before and after the trend interruption time point, and a time interval between the current time point and the trend interruption time point closest to the current time point is taken as an electromagnetic trend duration of the current time point. A mean value of the electromagnetic data of the remaining time points except the current time point in a preset time window of the current time point is calculated as a local electromagnetic central value of the current time point. The adjustment degree of the electromagnetic data of the current time point is acquired according to a difference between the local electromagnetic central value and the neighborhood electromagnetic central value and the electromagnetic trend duration, and the difference and the electromagnetic trend duration are positively correlated to the adjustment degree.

7. A control device applied to a permanent magnet synchronous motor, characterized by, The device comprises a processor which, when executing, implements the steps of a control method for a permanent magnet synchronous motor as claimed in any one of claims 1 to 5.

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