A high frequency injection based experimental modeling method for synchronous reluctance motor

Abstract

The application relates to a high-frequency injection-based experimental modeling method for a synchronous reluctance motor, and relates to the technical field of motor control. The application is aimed at solving the problem of low accuracy of the existing motor modeling method and the problem that the motor modeling method cannot meet the demand of a high-performance motor control algorithm. In the operation process of the synchronous reluctance motor, the application measures the incremental inductance data corresponding to different current working points at different electric angles based on an inductance identification method of four-vector injection, integrates the incremental inductance data at different current working points at different electric angles, and constructs an electric angle-current-flux linkage surface; without considering the mutual inductance of the d-axis and the q-axis, the application constructs an electric angle-current-apparent self-inductance surface according to the d-axis flux linkage and the q-axis flux linkage corresponding to different current working points at different electric angles; and with the consideration of the mutual inductance of the d-axis and the q-axis, the application respectively constructs an electric angle-current-apparent self-inductance surface and an electric angle-current-apparent mutual inductance surface according to the d-axis flux linkage and the q-axis flux linkage corresponding to different current working points at different electric angles.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology. Background Technology

[0002] Synchronous reluctance motors (SRRMs) have existed for nearly a century, but only in recent years have they become a commercially viable application. SRRMs offer advantages such as simple structure, low cost, and high efficiency, making them an ideal replacement for mainstream induction motors. To maximize the advantages of low cost and high efficiency, a positionless control scheme combined with an optimal control strategy is essential. The application of these technologies requires obtaining the motor's inductance parameters before normal operation. However, SRRMs exhibit strong nonlinearity, and their inductance parameters change significantly with varying operating conditions. Due to magnetic saturation, the inductance parameters change with the applied current. Furthermore, the high salient pole ratio of the motor structure leads to large air gap flux harmonics, causing the motor inductance parameters to vary with the rotor position angle. Accurately modeling the nonlinear characteristics of the motor parameters is crucial for fully leveraging the motor's inherent advantages and maximizing system performance.

[0003] The model of a motor can be obtained using the finite element method. However, the commonly used two-dimensional finite element method cannot account for the effects of end effects and deviations during the manufacturing process on motor parameters. Furthermore, in practical applications, commercially available synchronous reluctance motors do not provide finite element models. Therefore, experimental modeling is a more feasible approach. Experimental modeling essentially involves obtaining a mapping table of different operating conditions and motor parameters through parameter identification, thereby achieving nonlinear modeling of the motor.

[0004] Currently, there are two main parameter identification schemes: observer-based schemes and high-frequency injection-based schemes. Observer-based schemes generally estimate target parameters during motor rotation. While they can model the changes in motor parameters with the current operating point, they are bandwidth-limited, resulting in a lag between estimated and actual values. Therefore, they can only estimate steady-state or average values, and cannot track changes in motor parameters with angle. In contrast, high-frequency injection-based schemes offer higher bandwidth and are a better choice for modeling motor parameters with angle. However, existing methods suffer from underrank identification, failing to simultaneously obtain all motor parameters, including d-axis inductance, q-axis inductance, and dq-axis mutual inductance. Furthermore, high-frequency injection-based methods identify incremental inductance, while motor torque calculation and efficiency optimization control require apparent inductance. Due to magnetic saturation, the incremental and apparent inductance of a synchronous reluctance motor are not equal; therefore, additional testing and corresponding calculation methods are needed to convert between parameters.

[0005] In summary, current observer-based motor modeling methods cannot model parameter changes with motor angle and position, reducing model accuracy. On the other hand, high-frequency injection-based methods face problems in identifying underrank and obtaining the apparent inductance of the motor, failing to fully meet the application requirements of high-performance control algorithms for synchronous reluctance motors. Summary of the Invention

[0006] This invention addresses the shortcomings of observer-based experimental modeling methods for motors, which cannot model parameter variations with motor angle and position, thus reducing model accuracy. Furthermore, high-frequency injection-based methods suffer from issues such as identifying underranked parameters and failing to obtain the motor's apparent inductance, thus failing to fully meet the application requirements of high-performance control algorithms for synchronous reluctance motors. Therefore, this invention provides an experimental modeling method for synchronous reluctance motors based on high-frequency injection.

[0007] An experimental modeling method for synchronous reluctance motors based on high-frequency injection is as follows:

[0008] During the operation of a synchronous reluctance motor, the incremental inductance data corresponding to different current operating points at different electrical angles is measured using an inductance identification method based on four-vector injection. This incremental inductance data includes: d-axis incremental self-inductance l. d q-axis incremental self-inductance l q Incremental mutual inductance with dq axis l dq ;

[0009] By integrating the incremental inductance data at different current operating points under different electrical angles, the dq axis flux corresponding to different current operating points under different electrical angles is obtained, thus constructing the electrical angle-current-flux surface.

[0010] Without considering the mutual inductance of the dq axis, the apparent self-inductance of the dq axis is calculated based on the magnetic flux linkage of the dq axis corresponding to different current operating points under different electrical angles, thereby constructing the electrical angle-current-apparent self-inductance surface.

[0011] Considering the mutual inductance along the dq axis, the apparent self-inductance and apparent mutual inductance along the dq axis are calculated based on the magnetic flux linkages of the dq axis corresponding to different current operating points under different electrical angles, thereby constructing the electrical angle-current-apparent self-inductance surface and the electrical angle-current-apparent mutual inductance surface.

[0012] Furthermore, during the operation of the synchronous reluctance motor, the incremental inductance data corresponding to different current operating points at different electrical angles, measured by the inductance identification method based on four-vector injection, include:

[0013] Each electrical angle corresponds to n current operating points, k = 1, 2, ..., n. The initial value of the electrical angle is 0°. Under the same electrical angle, the k-th current operating point (i... d,k i q,k The corresponding current amplitude is denoted as i.sk And there are i d,k and i q,k These represent the d-axis and q-axis currents corresponding to the k-th current operating point, and the current amplitude difference Δi between two adjacent current operating points. s All are equal.

[0014] Given an electrical angle θ e Next k-th current operating point Then, four symmetrical voltage vectors are injected sequentially into the dq axis of the running synchronous reluctance motor during four consecutive PWM cycles to obtain the current increment and current increment difference generated by the injected voltage vector of the synchronous reluctance motor.

[0015] Construct a current increment difference model:

[0016]

[0017] in, For the x-th voltage vector and the y-th voltage vector The difference in current increments, x = 1, 2, 3, 4, y = 1, 2, 3, 4, x ≠ y. For the x-th voltage vector and the y-th voltage vector The composite vector, Y dq =Y Σ I+Y Δ , L Δ =(l d -l q ) / 2 is the half-differential inductance, L Σ =(l d +l q ) / 2 is the average inductance;

[0018] Construct three intermediate signals S a S b S c :

[0019]

[0020]

[0021]

[0022] in, and They represent The d-axis and q-axis components;

[0023] Substitute the four symmetrical voltage vectors and their corresponding current increment differences into the current increment difference model, and combine this with the three intermediate signals S. a S b S c Estimate the output angle θ e Next k-th current operating point Corresponding incremental inductance data:

[0024] d-axis incremental self-inductance:

[0025] q-axis incremental self-inductance:

[0026] Incremental mutual inductance along the dq axis:

[0027] Among them, u in T represents the magnitude of the injected voltage vector. s This is the PWM period.

[0028] Furthermore, the composite vector of the above four symmetrical voltage vectors is zero, and the difference between the voltage vectors injected in two adjacent PWM cycles is parallel to the d-axis or q-axis. The four symmetrical voltage vectors are respectively represented as:

[0029]

[0030]

[0031]

[0032]

[0033] The resultant vector of two adjacent voltage vectors is represented as follows:

[0034] and Composite vector:

[0035] and Composite vector:

[0036] and Composite vector:

[0037] and Composite vector:

[0038] Furthermore, after injecting the four voltage vectors mentioned above, the current increments generated by the synchronous reluctance motor are as follows:

[0039]

[0040]

[0041]

[0042]

[0043] in, Injected into the dq axis of the synchronous reluctance motor during the j-th PWM cycle The current generated afterwards Injection into the dq axis of the synchronous reluctance motor during the (j-1)th PWM cycle The current generated afterwards.

[0044] Furthermore, the above current increment difference is:

[0045]

[0046]

[0047]

[0048]

[0049] Furthermore, the method for constructing the current increment difference model described above is as follows:

[0050] Clark transformation is used to transform the three-phase sampling current of the synchronous reluctance motor from the abc coordinate system to the αβ coordinate system;

[0051] The Park transformation is used to transform the current in the αβ coordinate system to the dq coordinate system;

[0052] Establish the current difference equation in the dq coordinate system:

[0053]

[0054] in, i d and i q These represent the d-axis and q-axis currents in the dq coordinate system, respectively. d and u q R represents the voltage along the d-axis and q-axis in the dq coordinate system. s Let ω be the stator resistance of the synchronous reluctance motor, and ω be the rotor angular velocity of the synchronous reluctance motor.

[0055] A current increment difference model is constructed based on the current difference equation in the dq coordinate system.

[0056] Furthermore, the three-phase sampling current of the synchronous reluctance motor is transformed from the abc coordinate system to the αβ coordinate system using the following formula:

[0057]

[0058] Among them, i a i b i c These are the sampled currents of phases a, b, and c of the synchronous reluctance motor, i α and i β Let α and β be the currents in the αβ coordinate system, respectively;

[0059] The current in the αβ coordinate system is transformed to the dq coordinate system using the following formula:

[0060]

[0061] Among them, i d and i q These are the d-axis and q-axis currents in the dq coordinate system, respectively.

[0062] Furthermore, the aforementioned electrical angle θ e The flux linkage corresponding to the nth current operating point is:

[0063]

[0064]

[0065] in, and They are respectively at electrical angle θ e The d-axis and q-axis flux linkages corresponding to the nth current operating point are and They are respectively at electrical angle θ e The d-axis and q-axis current increments from the k-th current operating point to the (k-1)-th current operating point. For the electrical angle θ e The average value of the d-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point. For the electrical angle θ e The average value of the q-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point. For the electrical angle θ e The average incremental mutual inductance between the k-th current operating point and the (k-1)-th current operating point.

[0066] Furthermore, without considering the mutual inductance of the dq axis, the formula for calculating the apparent self-inductance of the dq axis is as follows:

[0067]

[0068]

[0069] in, and They are respectively at electrical angle θ e The apparent self-inductance along the d-axis and q-axis corresponding to the k-th current operating point is... and They are respectively at electrical angle θ e The d-axis and q-axis flux linkages corresponding to the k-th current operating point are as follows: and They are respectively at electrical angle θ e The d-axis and q-axis currents at the k-th current operating point.

[0070] Furthermore, considering the mutual inductance along the dq axis, the formulas for calculating the apparent self-inductance and apparent mutual inductance along the dq axis are as follows:

[0071]

[0072]

[0073]

[0074]

[0075] in, For the electrical angle θ e Lower current operating point The corresponding d-axis apparent self-inductance, For the electrical angle θ e Lower current operating point The corresponding q-axis apparent self-inductance, For the electrical angle θ e Lower current operating point The corresponding d-axis flux linkage, For the electrical angle θ e Lower current operating point The corresponding q-axis flux linkage, For the electrical angle θ e The right-angle mutual inductance corresponding to the k-th current operating point. For the electrical angle θ e The mutual inductance of the direct and quadrature axes corresponding to the k-th current operating point.

[0076] This invention provides an experimental modeling method for synchronous reluctance motors based on high-frequency injection. This method not only considers the variation of inductance parameters with the current operating point caused by magnetic saturation, but also the variation of inductance parameters with rotor angular position caused by large air gap flux harmonics. The method proposed in this invention provides a reliable and accurate motor model for high-performance control of synchronous reluctance motors, and can be used in multiple control fields, including but not limited to positionless control, torque predictive control, and efficiency-optimal control. Attached Figure Description

[0077] Figure 1 This is an overall block diagram of the experimental modeling method for synchronous reluctance motors based on high-frequency injection;

[0078] Figure 2 This is a schematic diagram of the test platform;

[0079] Figure 3 It is an injection voltage mode diagram of a four-vector high-frequency square wave vector;

[0080] Figure 4 This is a diagram of a four-vector high-frequency square wave vector synthesized signal;

[0081] Figure 5 It is the incremental inductance diagram obtained from modeling;

[0082] Figure 6 It is the magnetic flux and apparent inductance diagram obtained from the model. Detailed Implementation

[0083] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0084] Combination Figure 1 As shown, this embodiment provides an experimental modeling method for a synchronous reluctance motor based on high-frequency injection. This method calculates the flux linkage and apparent inductance based on the estimated incremental inductance. Theoretically, the flux linkage or inductance (including incremental inductance and apparent inductance) and i can be obtained by estimating the incremental inductance at any angle and current operating point. d i q and θ e The four-dimensional table is used as the modeling result. However, the testing burden is relatively large, as the four-dimensional tables for magnetic flux and inductance require a lot of storage space. To facilitate the application of this method, this embodiment provides an experimental modeling method for specific current trajectories. The specific testing platform is as follows: Figure 2As shown, taking a 3-kW synchronous reluctance motor prototype as an example, the PWM (Pulse Width Modulation) frequency is 10kHz, the injected voltage amplitude is 60V, and the bus voltage amplitude is 540V. The tested motor and the load motor run coaxially via a coupling. The load motor operates at a constant speed and has a sufficiently low speed to drive the test motor. Combined with... Figure 1 The synchronous reluctance motor used for testing operates in current loop mode, and the reference current of the dq axis is obtained from the MTPA (maximum torque-to-current ratio) table.

[0085] The experimental modeling method for synchronous reluctance motors based on high-frequency injection described in this embodiment is as follows:

[0086] Step 1: During the operation of the synchronous reluctance motor, a current operating point (i) is given. d i q The electrical angle θ is measured using an inductor identification method based on four-vector injection. e The incremental inductance data below. Specifically:

[0087] In four consecutive PWM cycles, four symmetrical voltage vectors are sequentially injected into the dq axis of the synchronous reluctance motor. The four symmetrical voltage vectors are represented as follows:

[0088]

[0089]

[0090]

[0091]

[0092] Among them, u in This represents the magnitude of the injected voltage vector.

[0093] like Figure 3 As shown, the difference between the voltage vectors injected in two adjacent PWM cycles is parallel to the d-axis or q-axis. The resultant vector of the four symmetrical voltage vectors is zero, and the resultant vector of two adjacent voltage vectors is expressed as follows:

[0094] and Composite vector:

[0095] and Composite vector:

[0096] and Composite vector:

[0097] and Composite vector:

[0098] After injecting four voltage vectors, the current increment generated by the synchronous reluctance motor is:

[0099]

[0100]

[0101]

[0102]

[0103] in, The injection into the dq axis of the synchronous reluctance motor during the j-th PWM cycle is respectively The current generated afterwards Injection into the dq axis of the synchronous reluctance motor during the (j-1)th PWM cycle The current generated afterwards.

[0104] The difference in current increment is:

[0105]

[0106]

[0107] Combination Figure 1 As shown, the Clark transform is used to convert the three-phase sampled current i of the synchronous reluctance motor. a i b i c Transformation from the abc coordinate system to the αβ coordinate system:

[0108]

[0109] Among them, i α and i β Let α and β be the currents in the αβ coordinate system, respectively.

[0110] Using the Park transformation to transform i α and i β Transform to the dq coordinate system:

[0111]

[0112] Where, θ e i is the electrical angle of the synchronous reluctance motor. d and i q These are the d-axis and q-axis currents in the dq coordinate system, respectively.

[0113] Establish the current difference equation in the dq coordinate system:

[0114]

[0115] in, Y dq =Y Σ I+Y Δ , u d and u q R represents the voltage along the d-axis and q-axis in the dq coordinate system. s For stator resistance, The identity matrix is ​​ω, where ω is the rotor angular velocity. It is an orthogonal rotation matrix, L Δ =(l d -l q ) / 2 is the half-differential inductance, L Σ =(l d +l q ) / 2 is the average inductance.

[0116] A mathematical model of current increment is constructed based on the current difference equation in the dq coordinate system, thereby calculating the current increment difference model corresponding to two adjacent injected voltage vectors:

[0117]

[0118] in, For the x-th voltage vector and the y-th voltage vector The difference in current increments, x = 1, 2, 3, 4, y = 1, 2, 3, 4, x ≠ y. For the x-th voltage vector and the y-th voltage vector The composite vector.

[0119] Three intermediate signals S are constructed through addition and subtraction calculations. a S b S c :

[0120]

[0121]

[0122]

[0123] in, and They represent The d-axis and q-axis components.

[0124] Furthermore, the injected voltage is synthesized into a vector. and the difference in current increment Substituting these values ​​into the current increment difference model, we obtain the current increment difference and its correlation with the d-axis increment self-inductance l. d q-axis incremental self-inductance l q Incremental mutual inductance with dq axis l dq The relationship between the three intermediate signals S. a S b S c The incremental inductance data can be estimated:

[0125] d-axis incremental self-inductance:

[0126] q-axis incremental self-inductance:

[0127] Incremental mutual inductance along the dq axis:

[0128] Step 2, according to the equal current interval Δi s Increase the current amplitude to change the current operating point. Repeat the test method in step 1 to obtain the incremental inductance data corresponding to different current operating points at the same electrical angle. Change the electrical angle and repeat the above method to obtain the incremental inductance data corresponding to different current operating points at different electrical angles. If mutual inductance parameters are not considered, only the current operating point on the MTPA curve is tested; if mutual inductance parameters are required, the MTPA curve needs to be tested. d =0 curve and i q The current operating point on the three curves, including the =0 curve.

[0129] Given current operating point (i d i q Initial amplitude i s The value is 0, and i is determined based on the current trajectory curve. s The corresponding d-axis current i d and q-axis current i q Current trajectory curves include, but are not limited to, MTPA curves and i d =0 curve or i q =0 curve, etc.

[0130] Step 3: Obtain the dq-axis flux linkage by integrating the estimated incremental inductance. Specifically:

[0131] For i d -i q Two adjacent current operating points (i) at the same electrical angle in a plane d,k-1 i q,k-1 ) and (i d,k i q,kThe flux linkage between these two operating points can be linearized as follows:

[0132]

[0133]

[0134] Where k = 1, 2, ..., n, n is the total number of current operating points at the same electrical angle, and when k = 1, the initial current amplitude i s0 ψ is 0 d,k and ψ q,k Let ψ be the d-axis and q-axis flux linkages corresponding to the k-th current operating point. d,k-1 and ψ q,k-1 Let Δi be the d-axis and q-axis flux linkages corresponding to the (k-1)th current operating point. d,kk-1 and Δi q,kk-1 These represent the d-axis and q-axis current increments from the k-th current operating point to the (k-1)-th current operating point, respectively. This represents the average incremental mutual inductance between the k-th current operating point and the (k-1)-th current operating point. Let be the average value of the d-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point. Let be the average value of the q-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point, and we have:

[0135] l d,k and l d,k-1 Let l be the incremental self-inductance along the d-axis corresponding to the k-th current operating point and the (k-1)-th current operating point, respectively. q,k and l q,k-1 These are the q-axis incremental self-inductances corresponding to the k-th and (k-1)-th current operating points, respectively.

[0136] Based on the magnetic flux linkage between adjacent operating points, the magnetic flux linkage corresponding to different current operating points at different electrical angles can be derived:

[0137]

[0138]

[0139] in, and They represent the electrical angle θ, respectively. e Next nth current operating point The corresponding d-axis and q-axis flux linkages, and the electrical angle θ e Next k-th current operating point The current amplitude is denoted as And there are and They are respectively at electrical angle θ e The d-axis and q-axis current increments from the k-th current operating point to the (k-1)-th current operating point. For the electrical angle θ e The average value of the d-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point. For the electrical angle θ e The average value of the q-axis incremental self-inductance between the k-th current operating point and the (k-1)-th current operating point. For the electrical angle θ e The average incremental mutual inductance between the k-th current operating point and the (k-1)-th current operating point.

[0140] Step 4: Without considering the mutual inductance parameters of the dq axis, the apparent self-inductance of the dq axis can be calculated using the flux linkage at different current operating points at different angles as described in Step 3.

[0141] At electrical angle θ e The d-axis of the k-th current operating point is considered in the self-inductance:

[0142] At electrical angle θ e The q-axis apparent inductance at the k-th current operating point is:

[0143] and They are respectively at electrical angle θ e The d-axis and q-axis flux linkages corresponding to the k-th current operating point are as follows: and They are respectively at electrical angle θ e The d-axis and q-axis currents at the k-th current operating point.

[0144] When considering the d- and q-axis mutual inductance parameters, the d- and q-axis self-inductance parameters are only related to the uniaxial current, according to the MTPA curve and i... d =0 and i q The current amplitude-magnetic flux linkage curve corresponding to the 0 curve is used to calculate the apparent self-inductance and apparent mutual inductance along the dq axis:

[0145] At electrical angle θ e The d-axis of the current-operating point (id,k,0) is considered in the self-inductance:

[0146] At electrical angle θ e Lower current operating point (0, i q,k The q-axis appears to be in self-induction:

[0147] At electrical angle θ e The right-angle mutual inductance corresponding to the k-th current operating point:

[0148] At electrical angle θ e The mutual inductance of the quadrature and direct axes corresponding to the k-th current operating point:

[0149] in, For the electrical angle θ e Lower current operating point The corresponding d-axis flux linkage, For the electrical angle θ e Lower current operating point The corresponding q-axis flux linkage.

[0150] Thus, the modeling of incremental inductance, flux linkage, and apparent inductance of the synchronous reluctance motor at different angles when it operates along a specific current curve has been completed, which means that the experimental modeling of the synchronous reluctance motor has been realized.

[0151] To further illustrate the effectiveness of this implementation method and its specific implementation, in conjunction with... Figure 5 and Figure 6 The experimental results of the experimental modeling method of this embodiment are presented. Figure 5 The estimated results of the incremental inductance are shown. Figure 6 The estimation results for flux linkage and apparent inductance are shown. It can be seen that this implementation can not only model the changes in incremental inductance, apparent inductance, and flux linkage with the current amplitude, but also obtain the changes of these motor parameters with the rotor angular position.

[0152] It should be noted that although the embodiments of the present invention model motor parameters based on the MTPA curve, the method of the present invention can also model other current curves, including but not limited to the maximum torque-to-current ratio (MTPV) curve, field weakening curve, and id=iq curve. Furthermore, the method of the present invention can be further extended from modeling the current curve to modeling the inductance parameters of the entire current surface, ultimately obtaining a parameter model in the form of a four-dimensional mapping table between d-axis current, q-axis current, rotor angular position, and inductance or flux linkage parameters.

[0153] This embodiment employs a four-vector high-frequency injection scheme for incremental inductance estimation, overcoming the underrank problem of simultaneous identification of multiple inductance parameters in traditional methods. It can simultaneously estimate the d-axis, q-axis, and dq-axis inductances of the motor. Furthermore, the method proposed in this embodiment estimates the inductance parameters from the current increment information of the high-frequency injection response, thus allowing estimation within a single control cycle. This enables the embodiment to track changes in motor parameters with motor angle during motor rotation. Compared to methods that require sequential identification of inductance parameters at each angle, this embodiment is simpler to implement and can effectively shorten testing time.

[0154] This implementation method considers the difference between incremental inductance and apparent inductance caused by magnetic saturation, and provides corresponding test procedures and parameter conversion methods. Therefore, it can not only obtain the incremental inductance model of the motor, but also the flux linkage model and apparent inductance model of the motor, which can fully meet the needs of different motor control applications. The provided test procedure reduces the three-dimensional modeling problem that varies with angle and current operating point to a two-dimensional modeling problem for a specific current operating curve, which greatly reduces the testing burden while meeting engineering application requirements and has good engineering practical value.

[0155] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. An experimental modeling method for synchronous reluctance motors based on high-frequency injection, characterized in that, Specifically: During the operation of a synchronous reluctance motor, the incremental inductance data corresponding to different current operating points at different electrical angles is measured using an inductance identification method based on four-vector injection. This incremental inductance data includes: d-axis incremental self-inductance. q-axis incremental self-inductance Incremental mutual inductance with dq axis ; By integrating the incremental inductance data at different current operating points under different electrical angles, the dq axis flux corresponding to different current operating points under different electrical angles is obtained, thus constructing the electrical angle-current-flux surface. Without considering the mutual inductance of the dq axis, the apparent self-inductance of the dq axis is calculated based on the magnetic flux linkage of the dq axis corresponding to different current operating points under different electrical angles, thereby constructing the electrical angle-current-apparent self-inductance surface. Considering the mutual inductance of the dq axis, the apparent self-inductance and apparent mutual inductance of the dq axis are calculated according to the magnetic flux of the dq axis corresponding to different current operating points under different electrical angles, thereby constructing the electrical angle-current-apparent self-inductance surface and the electrical angle-current-apparent mutual inductance surface. The incremental inductance data corresponding to different current operating points at different electrical angles, measured by the four-vector injection inductance identification method during the operation of the synchronous reluctance motor, includes: Each electrical angle corresponds to One current operating point, The initial electrical angle is 0°. Under the same electrical angle, the first... Current operating point The corresponding current amplitude is denoted as And there are , and The first The d-axis and q-axis currents corresponding to each current operating point, and the difference in current amplitude between two adjacent current operating points. All are equal. Given electrical angle Next Current operating point Then, four symmetrical voltage vectors are injected sequentially into the dq axis of the running synchronous reluctance motor during four consecutive PWM cycles to obtain the current increment and current increment difference generated by the injected voltage vector of the synchronous reluctance motor. Construct a current increment difference model: ， in, For the first voltage vectors and the voltage vectors The difference in current increment, , , , For the first voltage vectors and the voltage vectors The composite vector, , , , , It is a half-differential inductor. Average inductance; Construct three intermediate signals , , : ， ， ， in, and They represent The d-axis and q-axis components; Substitute the four symmetrical voltage vectors and their corresponding current increment differences into the current increment difference model, and combine this with the three intermediate signals. , , Estimate the output angle Next Current operating point Corresponding incremental inductance data: d-axis incremental self-inductance: , q-axis incremental self-inductance: , Incremental mutual inductance along the dq axis: , in, The magnitude of the injected voltage vector. This is the PWM period.

2. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 1, characterized in that, The composite vector of the four symmetrical voltage vectors is zero, and the difference between the voltage vectors injected in two adjacent PWM cycles is parallel to the d-axis or q-axis. The four symmetrical voltage vectors are respectively represented as: ， ， ， ； The resultant vector of two adjacent voltage vectors is represented as follows: and Composite vector: , and Composite vector: , and Composite vector: , and Composite vector: .

3. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 2, characterized in that, After injecting four voltage vectors, the current increments generated by the synchronous reluctance motor are as follows: ， ， ， ， in, , , , The first During each PWM cycle, injection is applied to the dq axis of the synchronous reluctance motor. , , , The current generated afterwards For the first During each PWM cycle, injection is applied to the dq axis of the synchronous reluctance motor. The current generated afterwards.

4. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 3, characterized in that, The difference in current increment is: ， ， ， 。 5. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 1 or 2, characterized in that, The method for constructing the current increment difference model is as follows: The Clark transform is used to transform the three-phase sampled current of the synchronous reluctance motor from the abc coordinate system to... In coordinate system; Using Park transform The current in the coordinate system is transformed to the dq coordinate system; Establish the current difference equation in the dq coordinate system: ， in, , , and Let be the d-axis and q-axis currents in the dq coordinate system, respectively. and Let be the voltages along the d-axis and q-axis in the dq coordinate system, respectively. This refers to the stator resistance of a synchronous reluctance motor. This refers to the rotor angular velocity of the synchronous reluctance motor. ; A current increment difference model is constructed based on the current difference equation in the dq coordinate system.

6. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 5, characterized in that, The three-phase sampling current of the synchronous reluctance motor is transformed from the abc coordinate system to the following formula: In coordinate system: ， in, , , These are the sampled currents of phases a, b, and c of the synchronous reluctance motor, respectively. and They are respectively coordinate system and Current; The following formula will be used to... Current transformation from the d-coordinate system to the dq-coordinate system: ， in, and These are the d-axis and q-axis currents in the dq coordinate system, respectively.

7. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 1 or 2, characterized in that, electric angle Next The flux linkage corresponding to each current operating point is: ， ， in, and They are respectively at electrical angles Next The d-axis and q-axis flux linkages corresponding to each current operating point and They are respectively at electrical angle Next The current operating point to the first The d-axis and q-axis current increments at each current operating point For electrical angle Next The current operating point and the first The average value of the d-axis incremental self-inductance at each current operating point. For electrical angle Next The current operating point and the first The average value of the q-axis incremental self-inductance at each current operating point. For electrical angle Next The current operating point and the first The average value of incremental mutual inductance at each current operating point.

8. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 1 or 2, characterized in that, Without considering the mutual inductance of the dq axis, the formula for calculating the apparent self-inductance of the dq axis is as follows: ， ， in, and They are respectively at electrical angle Next The apparent self-inductance along the d-axis and q-axis corresponding to each current operating point and They are respectively at electrical angle Next The d-axis and q-axis flux linkages corresponding to each current operating point and They are respectively at electrical angle Next The d-axis and q-axis currents at each current operating point.

9. The experimental modeling method for a synchronous reluctance motor based on high-frequency injection according to claim 8, characterized in that, Taking into account the mutual inductance along the dq axis, the formulas for calculating the apparent self-inductance and apparent mutual inductance along the dq axis are as follows: ， ， ， ， in, For electrical angle Lower current operating point The corresponding d-axis apparent self-inductance, For electrical angle Lower current operating point The corresponding q-axis apparent self-inductance, For electrical angle Lower current operating point The corresponding d-axis flux linkage, For electrical angle Lower current operating point The corresponding q-axis flux linkage, For electrical angle Next The right-angle mutual inductance corresponding to each current operating point For electrical angle Next The mutual inductance of the AC and DC axes corresponding to each current operating point.

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