Hybrid permanent magnet variable flux memory motor error compensation magnetization state observation method

Abstract

The application discloses a kind of hybrid permanent magnet variable flux memory motor error compensation magnetization state observation methods, it is characterized in that, the method includes the following steps: obtaining the magnetization state value of hybrid permanent magnet variable flux memory motor, the magnetization state value is determined by magnetization state equation;Repeat measurement no-load permanent magnet flux under different magnetization level under different rotating speed to obtain accurate value;Characteristic curve and charge demagnetization current are obtained based on the permanent magnet flux value, and magnetization state adjustment curve is established;Based on the characteristic curve, the motor parameter under different magnetization state of the hybrid permanent magnet variable flux memory motor is obtained, to obtain magnetization compensation error.The monitoring precision of magnetization state in prior art is insufficient and the flexibility of data acquisition is insufficient, so that the error compensation magnetization state observation precision of hybrid permanent magnet variable flux memory motor can be improved.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method for dynamic error compensation (DEC) observation of magnetization state for a hybrid permanent magnet variable flux memory machine (HPM-VFMM). Background Technology

[0002] Traditional permanent magnet synchronous machines (PMSMs) typically use a single type of permanent magnet, which limits their ability to operate efficiently over a wide range and to flexibly adjust magnetization. The stator flux linkage observer used in direct torque control (DTC) systems suffers from accuracy issues when parameters are mismatched or change. Furthermore, the operation of PMSMs requires error compensation methods to ensure stability, necessitating the ability to analyze current operating parameters. Currently, commonly used error-compensated magnetization state observations rely on threshold calculations, which fails to address the needs of certain special operating conditions and thus cannot effectively improve observation accuracy.

[0003] Therefore, effectively addressing the current shortcomings in observation accuracy and the lack of effective exploration of operational parameters is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the issues of low observation accuracy in motor error compensation magnetization loading and insufficient effectiveness in mining operating parameters in existing technologies, this invention discloses the following technical solution:

[0005] A method for error compensation and magnetization state observation of a hybrid permanent magnet variable flux memory motor, the method comprising the following steps:

[0006] The magnetization state values ​​of a hybrid permanent magnet variable flux memory motor are obtained, and the magnetization state values ​​are determined by the magnetization state equation.

[0007] Accurate values ​​were obtained by repeatedly measuring the unloaded permanent magnet flux at different magnetization levels under different rotation speeds.

[0008] Based on the permanent magnet flux density, characteristic curves and magnetization / demagnetization currents are obtained, and magnetization state adjustment curves are established.

[0009] Based on the characteristic curve, the motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the magnetization compensation error.

[0010] Optionally, obtaining the magnetization state value of the hybrid permanent magnet variable flux memory motor, wherein the magnetization state value is determined by the magnetization state equation, includes:

[0011] The magnetization state equation is obtained as follows:

[0012]

[0013] Where, ψ pm ψ represents the unloaded permanent magnet flux linkage after applying a certain magnetizing current. pmmax and ψ pmmin These represent the unloaded permanent magnet flux linkage after applying the maximum charge / demagnetize current.

[0014] Optionally, the unloaded permanent magnet flux linkage at different magnetization levels can be repeatedly measured at different rotational speeds to obtain accurate values, including:

[0015] Offline adjustment of rotor positioning and magnetization state is performed before measurement;

[0016] This allows the hybrid permanent magnet variable flux memory motor to operate at a constant speed, thereby obtaining the effective value of the no-load line voltage of the hybrid permanent magnet variable flux memory motor.

[0017] The magnetization state value of the hybrid permanent magnet variable flux memory motor is adjusted based on the charging and demagnetizing current to obtain the permanent magnet flux value corresponding to the magnetization state value.

[0018] Optionally, adjusting the magnetization state value of the hybrid permanent magnet variable flux memory motor based on the charging and demagnetizing current to obtain the permanent magnet flux linkage value corresponding to the magnetization state value includes:

[0019] The permanent magnet flux linkage value is obtained based on the effective value of the unloaded line voltage;

[0020] Determine the demagnetizing current when the magnetization state value is 100%, and gradually increase the demagnetizing current until the magnetization state value reaches 0%.

[0021] Determine the magnetizing current when the magnetization state value is 0%, and gradually increase the magnetizing current until the magnetization state value reaches 100%.

[0022] Optionally, the step of obtaining the characteristic curve based on the permanent magnet flux linkage value and the charging / demagnetizing current, and establishing the magnetization state adjustment curve, includes:

[0023] The values ​​of the charging and demagnetizing currents and the permanent magnet flux linkages are obtained and integrated into the same coordinate system to obtain the magnetization state adjustment curve;

[0024] Based on the values ​​of the charging and demagnetizing currents and the permanent magnet flux linkage in the coordinate system, the fitting equation for the magnetization state adjustment curve is obtained.

[0025] Optionally, obtaining the fitting equation for the magnetization state adjustment curve based on the value of the demagnetizing current and the permanent magnet flux linkage in the coordinate system includes:

[0026] Obtain the d-axis pulse magnetization current of the hybrid permanent magnet variable flux memory motor;

[0027] Obtain the permanent magnet flux linkage value corresponding to the d-axis pulse tuning current;

[0028] Based on the d-axis pulse tuning current and the permanent magnet flux linkage value, the magnetization state adjustment curve is obtained; the equation of the motor flux linkage is obtained by fitting the magnetization state adjustment curve.

[0029] Optionally, the step of obtaining motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states based on the characteristic curve to obtain magnetization compensation error includes:

[0030] The motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the d-axis pulse magnetization current;

[0031] The magnetization state value is obtained based on the motor flux linkage equation.

[0032] The permanent magnet flux linkage value of the hybrid permanent magnet variable flux memory motor is obtained, and the interpolation of the magnetization state value and the permanent magnet flux linkage value is calculated to obtain the magnetization compensation error.

[0033] The present invention has the following beneficial effects:

[0034] 1. High-efficiency wide-range operation capability: The HPM-VFMM motor adopts a design combining high-coercivity and low-coercivity permanent magnets, enabling flexible magnetization adjustment while maintaining high torque density. This allows the motor to operate efficiently under different load conditions and adapt to a wider range of operating requirements. Specifically, by controlling the current vector to adjust the magnetization state, it can be flexibly adjusted between MS=0% and MS=100%, thus achieving high-efficiency operation over a wide range.

[0035] 2. Significantly Improve Dynamic Response Performance: The magnetization state observation method with dynamic error compensation can update motor parameters in real time under different magnetization states, and utilizes the inherent voltage disturbance term in the stator current observer to overcome the stator flux observation error caused by parameter variations under a fixed magnetization state. This method significantly improves the accuracy of direct torque control and enhances the dynamic response performance of the system.

[0036] 3. Enhanced stability and reliability of the observation system: To avoid frequent magnetization adjustments, the HPM-VFMM motor design incorporates range optimization for magnetization states. By dividing the motor's operating area into four regions (MS1, MS2, MS3, and MS4) and selecting appropriate magnetization states for operation, the stability and reliability of the motor under different load conditions can be guaranteed. In specific observation processes, this approach is also used to achieve error observation of the entire system, more closely reflecting actual operating conditions. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of exemplary embodiments of the present invention, the accompanying drawings used in describing the embodiments are briefly introduced below. Obviously, the accompanying drawings described are only a part of the embodiments to be described in this invention, and not all of them. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0038] Figure 1 This is a discrete-time principle block diagram of the hybrid permanent magnet variable flux memory motor error compensation magnetization state observation system in a specific embodiment of the present invention;

[0039] Figure 2 This is a characteristic curve of the magnetization state adjustment of the hybrid permanent magnet variable flux memory motor in a specific embodiment of the present invention;

[0040] Figure 3 In a specific embodiment of the present invention, MS4 is used for T. L =1.5Nm, d / q axis flux linkage waveform under operating conditions;

[0041] Figure 4 In a specific embodiment of the present invention, MS4 is used for T. L =1.5Nm, d / q axis flux linkage waveform under operating conditions;

[0042] Figure 5 In the specific embodiments of the present invention, T L =0.75Nm, waveforms of d / q axis flux linkage observed using GSO and DEC observers when adjusting the magnetism between MS4 and MS2. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0044] It should also be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention and not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. The process may correspond to a method, function, procedure, subroutine, subprogram, etc.

[0045] This specific embodiment discloses a method for error compensation and magnetization state observation of a hybrid permanent magnet variable flux memory motor, the principle block diagram of which is shown below. Figure 1 As shown. Includes:

[0046] A method for error compensation and magnetization state observation of a hybrid permanent magnet variable flux memory motor, the method comprising the following steps:

[0047] The magnetization state values ​​of a hybrid permanent magnet variable flux memory motor are obtained, and the magnetization state values ​​are determined by the magnetization state equation.

[0048] The towing platform was measured using an asynchronous motor, and the permanent magnet flux linkage was repeatedly measured at different speeds and magnetization levels to obtain accurate values.

[0049] Based on the permanent magnet flux density, characteristic curves and demagnetizing currents are obtained, and magnetization state adjustment curves are established.

[0050] Based on the characteristic curve, the motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the magnetization compensation error.

[0051] Optionally, obtaining the magnetization state value of the hybrid permanent magnet variable flux memory motor, wherein the magnetization state value is determined by the magnetization state equation, includes:

[0052] The magnetization state equation is obtained as follows:

[0053]

[0054] Where, ψ pm ψ represents the unloaded permanent magnet flux linkage after applying a certain magnetizing current. pmmax and ψ pmmin These represent the unloaded permanent magnet flux linkage after applying the maximum charge / demagnetize current.

[0055] Optionally, the step of using an asynchronous motor to measure the towing platform, repeatedly measuring the permanent magnet flux linkage at different magnetization levels at different speeds to obtain accurate permanent magnet flux linkage values, includes:

[0056] Offline adjustment of rotor positioning and magnetization state is performed before measurement;

[0057] This allows the hybrid permanent magnet variable flux memory motor to operate at a constant speed, thereby obtaining the effective value of the no-load line voltage of the hybrid permanent magnet variable flux memory motor.

[0058] The magnetization state value of the hybrid permanent magnet variable flux memory motor is adjusted based on the charging and demagnetizing current to obtain the permanent magnet flux value corresponding to the magnetization state value.

[0059] Optionally, adjusting the magnetization state value of the hybrid permanent magnet variable flux memory motor based on the charging and demagnetizing current to obtain the permanent magnet flux linkage value corresponding to the magnetization state value includes:

[0060] The permanent magnet flux linkage value is obtained based on the effective value of the unloaded line voltage;

[0061] Determine the demagnetizing current when the magnetization state value is 100%, and gradually increase the demagnetizing current until the magnetization state value reaches 0%.

[0062] Determine the magnetizing current when the magnetization state value is 0%, and gradually increase the magnetizing current until the magnetization state value reaches 100%.

[0063] Optionally, the step of obtaining the characteristic curve based on the permanent magnet flux linkage value and the charging / demagnetizing current, and establishing the magnetization state adjustment curve, includes:

[0064] The values ​​of the charging and demagnetizing currents and the permanent magnet flux linkages are obtained and integrated into the same coordinate system to obtain the magnetization state adjustment curve;

[0065] Based on the values ​​of the charging and demagnetizing currents and the permanent magnet flux linkage in the coordinate system, the fitting equation for the magnetization state adjustment curve is obtained.

[0066] Optionally, obtaining the fitting equation for the magnetization state adjustment curve based on the numerical values ​​of the charging and demagnetizing currents and the permanent magnet flux linkage in the coordinate system includes:

[0067] Obtain the d-axis pulse magnetization current of the hybrid permanent magnet variable flux memory motor;

[0068] Obtain the permanent magnet flux linkage value corresponding to the d-axis pulse tuning current;

[0069] Based on the d-axis pulse tuning current and the permanent magnet flux linkage value, the magnetization state adjustment curve is obtained; the equation of the motor flux linkage is obtained by fitting the magnetization state adjustment curve.

[0070] Optionally, the step of obtaining motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states based on the characteristic curve to obtain magnetization compensation error includes:

[0071] The motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the d-axis pulse magnetization current;

[0072] The magnetization state value is obtained based on the motor flux linkage equation.

[0073] The permanent magnet flux linkage value of the hybrid permanent magnet variable flux memory motor is obtained, and the interpolation of the magnetization state value and the permanent magnet flux linkage value is calculated to obtain the magnetization compensation error.

[0074] Figure 2 This is a magnetization state adjustment characteristic curve of a hybrid permanent magnet variable flux memory motor in a specific embodiment of the present invention. From the magnetization state adjustment curve, it can be seen that the permanent magnet flux linkage ψ of the motor... pm It concerns the d-axis pulse magnetizing current. The nonlinear function of the motor allows the motor operating region to be divided into the following modes:

[0075] When MS = 100%, the HPM-VFMM is driven by an asynchronous motor to operate at a constant speed n for power generation. At this time, the effective value of its no-load line voltage E is measured. Under this no-load steady-state operating condition, the permanent magnet flux linkage can be calculated as follows:

[0076]

[0077] Keeping MS = 100% constant, repeated measurements at different rotational speeds and averaging the results yielded the permanent magnet flux linkage of 0.126 Wb at MS = 100%. At this point, a demagnetizing current was applied. The amplitude is gradually increased, and when it exceeds -12A, the permanent magnet flux linkage remains basically at 0.018Wb and no longer decreases, at which point the motor is considered to have reached the MS=0% state. The permanent magnet flux linkage under MS=75%, MS=50%, MS=25% states can be calculated, such as ψ... pm_MS＝50％ =(ψ pm_MS＝100％ +ψ pm_MS＝0％ () / 2. Following the method described above, the demagnetizing current amplitude corresponding to different magnetization states can be measured, and the demagnetizing characteristic curve of the motor can be plotted. Similarly, starting from the MS=0% state, the magnetizing current is gradually increased, and the permanent magnet flux linkage value and the corresponding magnetizing current amplitude are measured under each magnetization state to obtain the magnetizing characteristic curve. Among these, the experimentally measured HPM-VFMM magnetization state adjustment characteristic curve is obtained.

[0078] The magnetization state adjustment curve shows that the permanent magnet flux linkage ψ of the motor... pm It concerns the d-axis pulse magnetizing current. The nonlinear function, after fitting the curve, yields the following fitting function:

[0079]

[0080] The function is a piecewise function, with fitting errors and coefficients of determination of 2.797e-6 and 0.9994 for the positive and negative halves, respectively, and 3.841e-6 and 0.9992 for the negative halves. This shows that the function fits the magnetization state adjustment characteristics very well. To avoid frequent magnetization adjustments in the HPM-VFMM and ensure its stable and reliable operation, its magnetization state needs to be optimized within a specific range. The selection of the motor magnetization state and the amplitude of the d-axis magnetization current divides the motor operating region into four regions: MS1, MS2, MS3, and MS4, representing MS = 25%, MS = 50%, MS = 75%, and MS = 100%, respectively. When the magnetization state satisfies MS... k-1 <MS≤MS k At that time, a higher magnetization state is selected, i.e., MS = MS. k Here, k = 1, 2, 3, 4. When the motor is at MS = 0%, MS = MS1 is taken to ensure the motor's load-carrying capacity. In addition, the motor is set to start at MS = 100%, that is, a rotor positioning and magnetization operation must be completed before starting.

[0081] When the motor needs to be magnetized, the generated data lookup table can quickly and accurately obtain the required magnetization state and the magnitude of the d-axis magnetization current to be applied. The step values ​​of each magnetization state in the x-axis direction represent the limit values ​​of the charging and demagnetizing current to maintain the current magnetization state.

[0082] The basic principle of the DEC magnetization state observation method is to update the motor parameters under different magnetization states in real time, and to use the inherent voltage disturbance term in the SCO (Stator Current Observer, SCO) to overcome the stator flux observation error caused by parameter variations under the fixed magnetization state of HPM-VFMM. The current observer here is constructed using a Luenberger observer.

[0083] Assuming the observed current in SCO It can track and measure current well under steady-state conditions. When the motor maintains its rated parameters, the output of the current controller in SCO can be obtained according to the nodal method. With stator voltage The discrete equations between them are:

[0084]

[0085] Neglecting the derivative term under steady state, we obtain the following equation:

[0086]

[0087] After organizing it, we can obtain:

[0088]

[0089] In the case of observing current tracking measurement current, i.e. Then, based on the flux linkage equation, it can be further simplified to:

[0090]

[0091] In the formula, ΔR s , These represent the errors between the actual and observed values ​​of the steady-state stator resistance and the d / q-axis stator flux linkage, respectively. Equation (3.59) shows the estimation error of the stator current in the SCO due to parameter variations, compensated by the current controller. When the stator resistance changes little, equation (3.59) can be simplified to:

[0092]

[0093] This can be further rewritten as:

[0094]

[0095] That is, the observation error of the d / q axis stator flux linkage. The output voltage of the current controller in SCO can be used. Calculated.

[0096] Stator flux linkage observation errors can be compensated for under the current magnetization state by incorporating them into a cascaded Gopinath Style Observer (GSO). Within the bandwidth of the SCO, if accurate inductance and permanent magnet flux linkage exist under a given magnetization state, the observed current will equal the measured current, meaning the controller's output interference voltage will be approximately zero. Furthermore, even small deviations in inductance and permanent magnet flux linkage parameters can be compensated for under the closed-loop control of the SCO. However, HPM-VFMM exhibits different stator flux linkage observation errors under different magnetization states. k and d / q axis current The parameters vary considerably, especially L. d L q ψ pm To reduce the stator flux linkage observation error caused by parameter changes during the magnetization process, the inductance surfaces under different magnetization states measured in Chapter 2 can be pre-prepared into a lookup table as the observed values ​​for each parameter. Therefore, the proposed discrete-time model of the DEC stator flux linkage observer enables dynamic error compensation for magnetization state observation. Under a fixed magnetization state, the observer's sensitivity to inductor saturation effects and temperature-induced permanent magnet flux linkage changes can be reduced by compensating for flux linkage errors obtained from SCO perturbation voltages. Under different magnetization states, parameter deviations caused by magnetization operations can be compensated by querying pre-set permanent magnet flux linkage and inductor surface parameters.

[0097] For DEC magnetization state observations, including:

[0098] (1) Fixed magnetization state

[0099] like Figure 3 As shown, this is a specific embodiment of the present invention under MS4 T. L =1.5Nm, The d / q axis flux linkage waveforms under operating conditions are shown. To verify the steady-state performance of the DEC magnetization state observation method under a fixed magnetization state, it was applied to a deadbeat direct torque-flux control system and tested under conditions of mismatched motor observation parameters. Here, the magnetization state is selected as MS4 and the load torque is T. L =1.5Nm, permanent magnet flux linkage of the observer Set as actual permanent magnet flux linkage ψ pm 0.95x operating condition. The d / q axis flux linkage test waveforms obtained using GSO and DEC observers are shown below. Figure 3 (a) is a comparison chart of measured values ​​and GSO observations. Figure 3 (b) is a comparison chart of measured values ​​and DEC observations. These represent the d / q-axis current measurement value and the d / q-axis flux linkage measurement value obtained using the current model under this magnetization state, respectively. These represent the d / q-axis flux linkage observations obtained using GSO. These represent the d / q axis flux linkage observations obtained using the DEC magnetization state observation method.

[0100] The flux linkage observations obtained using a conventional GSO show significant deviations from the measured values, especially the d-axis flux linkage, where the observation bias is approximately 9%, and the observation fluctuation error is also significant, at approximately 5.7%. In contrast, the d / q-axis flux linkage observations obtained using a DEC observer all deviate from their corresponding measured values ​​by less than 1%, and the observation fluctuation error is reduced to 2.6%.

[0101] like Figure 4 As shown, this is a specific embodiment of the present invention under MS4 T. L =1.5Nm, The d / q axis flux linkage waveforms under operating conditions. This is because the HPM-VFMM operates under a fixed magnetization state. It is 0, therefore when Ld When there is an observer parameter mismatch There is virtually no bias error; while when L q When there is an observer parameter mismatch The bias error is relatively significant, approximately 4%. Under both operating conditions, the d / q-axis flux linkage observations obtained using the DEC observer deviate from their corresponding measured values ​​by less than 1%, and the observation fluctuation error is less than 2%. Compared to the GSO, its steady-state observation accuracy is higher. Figure 4 (a) is a comparison chart of the observed values ​​and GSO observed values. Figure 4 (b) is a comparison chart of the observed values ​​and the DEC observed values. The experimental results above show that the DEC stator flux linkage observer has strong robustness to changes in motor parameters.

[0102] (2) Transient magnetization

[0103] like Figure 5 As shown, in a specific embodiment of the present invention, T L =0.75Nm, the waveforms of the d / q axis flux linkage observed by the GSO and DEC observers during magnetization adjustment between MS4 and MS2 are shown. To verify the transient performance of the DEC magnetization state observation method during magnetization adjustment, the load torque T is also considered. L An experiment was conducted to investigate the magnetization and demagnetization process between MS4 and MS2 at a magnetization state of 0.75 Nm, and the flux linkage waveform was obtained. These represent the d / q-axis flux linkage observations obtained using GSO. These represent the d / q axis flux linkage observations obtained using the DEC magnetization state observation method.

[0104] To maintain a constant electromagnetic torque during the magnetization process of the HPM-VFMM, a predetermined stator flux linkage trajectory is applied to the motor, i.e., the flux linkage is reduced during the demagnetization process. At the same time, appropriately increase Conversely, the magnetization process increases At the same time, appropriately reduce Both during demagnetization and magnetization, the DEC observer can accurately observe the stator flux linkage, while the GSO observer's observations show bias after demagnetization, especially noticeable in the d-axis stator flux linkage. The fluctuation errors of the two observers also differ, with the DEC observer's fluctuation error being 40% that of the GSO observer. Furthermore, the q-axis flux linkage observations from both methods exhibit more pronounced spikes. The peak values ​​are respectively less than The proposed DEC magnetization state observation method can effectively resist observation disturbances caused by the magnetization process and has a certain degree of robustness.

[0105] This application has the following beneficial effects:

[0106] 1. High-efficiency wide-range operation capability: The HPM-VFMM motor adopts a design combining high-coercivity and low-coercivity permanent magnets, enabling flexible magnetization adjustment while maintaining high torque density. This allows the motor to operate efficiently under different load conditions and adapt to a wider range of operating requirements. Specifically, by controlling the current vector to adjust the magnetization state, it can be flexibly adjusted between MS=0% and MS=100%, thus achieving high-efficiency operation over a wide range.

[0107] 2. Significantly Improve Dynamic Response Performance: The magnetization state observation method with dynamic error compensation can update motor parameters in real time under different magnetization states, and utilizes the inherent voltage disturbance term in the stator current observer to overcome the stator flux observation error caused by parameter variations under a fixed magnetization state. This method significantly improves the accuracy of direct torque control and enhances the dynamic response performance of the system.

[0108] 3. Enhanced stability and reliability of the observation system: To avoid frequent magnetization adjustments, the HPM-VFMM motor design incorporates range optimization for magnetization states. By dividing the motor's operating area into four regions (MS1, MS2, MS3, and MS4) and selecting appropriate magnetization states for operation, the stability and reliability of the motor under different load conditions can be guaranteed. In specific observation processes, this approach is also used to achieve error observation of the entire system, more closely reflecting actual operating conditions.

[0109] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation, characterized in that, The method includes the following steps: The magnetization state value of the hybrid permanent magnet variable flux memory motor is obtained, and the magnetization state value is determined by the magnetization state equation; Accurate values ​​were obtained by repeatedly measuring the unloaded permanent magnet flux at different magnetization levels under different rotation speeds. Based on the permanent magnet flux density, characteristic curves and magnetization / demagnetization currents are obtained, and magnetization state adjustment curves are established. Based on the characteristic curve, the motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the magnetization compensation error.

2. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to claim 1, characterized in that, The process of obtaining the magnetization state value of the hybrid permanent magnet variable flux memory motor, wherein the magnetization state value is determined by the magnetization state equation, includes: The magnetization state equation is obtained as follows: Where, ψ pm ψ represents the unloaded permanent magnet flux linkage after applying a certain magnetizing current. pmmax and ψ pmmin These represent the unloaded permanent magnet flux linkage after applying the maximum charge / demagnetize current.

3. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to claim 1, characterized in that, The method of repeatedly measuring the unloaded permanent magnet flux linkage at different magnetization levels at different rotational speeds to obtain accurate values ​​includes: Offline adjustment of rotor positioning and magnetization state is performed before measurement; This allows the hybrid permanent magnet variable flux memory motor to operate at a constant speed, thereby obtaining the effective value of the no-load line voltage of the hybrid permanent magnet variable flux memory motor. The magnetization state value of the hybrid permanent magnet variable flux memory motor is adjusted based on the charging and demagnetizing current to obtain the permanent magnet flux value corresponding to the magnetization state value.

4. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to claim 3, characterized in that, The step of adjusting the magnetization state value of the hybrid permanent magnet variable flux memory motor based on the charging and demagnetizing current to obtain the permanent magnet flux linkage value corresponding to the magnetization state value includes: The permanent magnet flux linkage value is obtained based on the effective value of the unloaded line voltage; Determine the demagnetizing current when the magnetization state value is 100%, and gradually increase the demagnetizing current until the magnetization state value reaches 0%. Determine the magnetizing current when the magnetization state value is 0%, and gradually increase the magnetizing current until the magnetization state value reaches 100%.

5. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to any one of claims 1-4, characterized in that, The step of obtaining the characteristic curve and demagnetizing current based on the permanent magnet flux linkage value, and establishing the magnetization state adjustment curve, includes: The values ​​of the demagnetizing current and the permanent magnet flux linkage are obtained and integrated into the same coordinate system to obtain the magnetization state adjustment curve; Based on the value of the demagnetizing current and the permanent magnet flux linkage in the coordinate system, the fitting equation for the magnetization state adjustment curve is obtained.

6. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to claim 5, characterized in that, The fitting equation for the magnetization state adjustment curve, based on the value of the demagnetizing current and the permanent magnet flux linkage in the coordinate system, includes: Obtain the d-axis pulse magnetization current of the hybrid permanent magnet variable flux memory motor; Obtain the permanent magnet flux linkage value corresponding to the d-axis pulse tuning current; Based on the d-axis pulse tuning current and the permanent magnet flux linkage value, the magnetization state adjustment curve is obtained; The motor flux linkage equation is obtained by fitting the magnetization state adjustment curve with an equation.

7. The method for observing the magnetization state of a hybrid permanent magnet variable flux memory motor with error compensation according to claim 1, characterized in that, Based on the characteristic curve, the motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the magnetization compensation error, including: The motor parameters of the hybrid permanent magnet variable flux memory motor under different magnetization states are obtained to obtain the d-axis pulse magnetization current; The magnetization state value is obtained based on the motor flux linkage equation. The permanent magnet flux linkage value of the hybrid permanent magnet variable flux memory motor is obtained, and the interpolation of the magnetization state value and the permanent magnet flux linkage value is calculated to obtain the magnetization compensation error.

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