A method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors

Abstract

This invention discloses a method for rapidly calculating and generating a high-fidelity efficiency MAP for a permanent magnet synchronous motor (PMSM). The steps are as follows: 1. Construct a saturated flux linkage model and a speed-scalable iron loss model in parallel, and calculate the torque matrix model without considering the iron loss effect; 2. Calculate the speed-torque envelope of the PMSM using the model from step 1; 3. Select the speed-torque combination required for calculating the efficiency MAP within the speed-torque envelope, and use the efficiency-optimal current search method for the PMSM considering the iron loss effect to search for the current operating point and corresponding iron loss for each operating condition, and calculate the copper loss; 4. Generate the efficiency MAP using the iron loss and copper loss from step 3. This method can accurately and quickly calculate the motor efficiency MAP under efficiency-optimal current control, MTPA, and field weakening control modes, requiring only a small amount of finite element calculations, avoiding a large number of repeated experiments or finite element calculations. The calculation process considers the influence of iron loss on torque, and the calculated efficiency MAP has high fidelity.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are synchronous motors that utilize permanent magnets to establish an excitation magnetic field. Their stator generates a rotating magnetic field, and the rotor is made of permanent magnet materials. Depending on the rotor structure, they can be classified as surface-mounted or internally mounted. Due to their advantages such as wide speed range, high starting torque, low noise, and low torque ripple, they are widely used in electric vehicles, rail transportation, aerospace, and wind power generation. Energy efficiency, power density, and operating point are crucial attributes that play a decisive role in the performance of PMSMs.

[0003] Motor efficiency MAPs are commonly used to represent and compare motor performance. They are contour plots of motor efficiency against torque and speed. An efficiency MAP not only shows the speed-torque capability envelope of the motor but also displays the efficiency of the motor at all possible operating points under a given control method. (Efficiency MAP of a permanent magnet synchronous motor is an example.) Figure 1 Efficiency MAPs are typically obtained through experiments or finite element methods. Experimental methods require complex and precise equipment for testing, as well as testing numerous operating points, each requiring multiple tests to obtain the control current needed for the chosen control method. Similarly, obtaining the efficiency MAP using the finite element method involves extensive and iterative calculations, which is time-consuming, labor-intensive, and costly. Additionally, some methods utilize inductance or flux linkage models of permanent magnet synchronous motors to calculate the motor efficiency MAP, but these generally fail to account for the impact of iron losses on torque, resulting in low fidelity of the efficiency MAP. Summary of the Invention

[0004] In view of at least one deficiency of the prior art, the purpose of this invention is to provide a method for rapid calculation and generation of high-fidelity efficiency MAPs for permanent magnet synchronous motors, so as to solve the problems of high workload and high cost caused by repeated and extensive calculations required by traditional motor efficiency MAPs obtained through experiments or finite element methods, or the problem of low fidelity of results when calculating efficiency MAPs through inductance or flux linkage models without considering the influence of iron loss effect on motor torque.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors, the method comprising the following steps:

[0006] 1. Construct a saturated flux linkage model and an iron loss model that can be scaled based on rotational speed in parallel. Calculate the torque matrix model under full current conditions without considering the iron loss effect using the saturated flux linkage model.

[0007] 2. The motor speed is divided into equal intervals. Using a speed-scalable iron loss model, the iron loss matrix corresponding to the full current condition at each speed can be calculated. Further calculations are made of the torque matrix due to iron loss and the torque matrix considering the iron loss effect at each speed. The maximum torque achievable at each speed while satisfying the current and voltage limit circles is extracted to obtain the motor speed-torque envelope.

[0008] 3. Select the speed-torque combination required for calculating the efficiency MAP within the speed-torque envelope, and use the efficiency-optimal current search method for permanent magnet synchronous motor considering iron loss effect to search for the current operating point and corresponding iron loss for each operating condition and calculate the copper loss.

[0009] IV. Use the iron and copper losses from step three to generate an efficiency MAP.

[0010] Preferably, the construction process of the saturated flux linkage model and the iron loss model that can be scaled based on rotational speed in step one is as follows: Within the range encompassing the motor current limit circle, the d-axis current and q-axis current are divided at equal or unequal intervals, or the current amplitude and phase angle are divided as selected current operating points. The selected current operating points are calculated using the finite element method at a certain rotational speed ω, simultaneously obtaining the d-axis flux linkage matrix, the q-axis flux linkage matrix, and the iron loss matrix at that rotational speed. The matrices are interpolated to obtain the d-axis flux linkage matrix encompassing all current operating points within the motor current limit circle. q-axis flux linkage matrix and the iron loss matrix P at that rotational speed Fe_ω (i d i q The iron loss matrix includes the hysteresis loss matrix P. Fe_hys_ω (i d i q ,ω) and eddy current loss P Fe_eddy_ω (i d i q The matrix (ω) represents the saturation flux linkage model and the iron loss model that can be scaled based on rotational speed:

[0011]

[0012]

[0013] P Fe_hys_ω (i d i q ,ω)=P Fe_hys_ω (i m ,θ,ω)

[0014] P Fe_eddy_ω (i d i q ,ω)=P Fe_eddy_ω (i m ,θ,ω)

[0015] P Fe_ω (i d i q ,ω)=P Fe_ω (i m ,θ,ω)=P Fe_hys_ω (i d i q ,ω)+P Fe_eddy_ω (i d i q ,ω)

[0016] Where i d Let i be the d-axis current. q Let i be the q-axis current. m θ is the current amplitude, and θ is the current phase angle.

[0017] The current limit circle mentioned above refers to the maximum allowable current amplitude of the motor, where the current amplitude i is... m It can also be calculated from the d-axis current and q-axis current:

[0018]

[0019] The torque matrix T1 under the full current condition, which does not consider iron loss, described in step one, is obtained through matrix calculation based on the d-axis flux linkage matrix, the q-axis flux linkage matrix, and the corresponding current matrix. The calculation formula is as follows:

[0020]

[0021] Where P is the number of pole pairs of the motor, i d_bu To construct the d-axis current matrix, i q_bu To construct the q-axis current matrix. The corresponding current matrix refers to the current matrix that corresponds to the saturation flux linkage matrix, the T1 matrix, and the iron loss matrix. Taking the saturation flux linkage matrix as an example, i... d_bu and i q_bu The d-axis flux linkage and q-axis flux linkage generated by the d-axis current value and q-axis current value at any coordinate position are the d-axis flux linkage value and q-axis flux linkage value corresponding to the same coordinate position in the saturation flux linkage matrix.

[0022] Preferably, in step two, the iron loss matrix corresponding to the full current operating condition at each speed is calculated using an iron loss model that can be scaled based on rotational speed. The calculation formula is as follows:

[0023]

[0024]

[0025] P Fe_ω' (i d iq ,ω')=P Fe_hys_ω' (i d i q ,ω')+P Fe_eddy_ω' (i d i q ,ω')

[0026] This formula can be used to calculate the iron loss matrix under full current conditions at any division of rotational speed ω'.

[0027] Preferably, at a given rotational speed ω', the torque matrix T2 due to iron loss in step two is obtained using the iron loss matrix P. Fe_ω' The calculation is as follows:

[0028] T2 = P Fe_ω' / ω'

[0029] For an electric motor, at a given speed ω', the torque matrix T considering iron loss in step two is calculated by subtracting the torque matrix T2 due to iron loss from the torque matrix T1 that does not consider iron loss:

[0030] T = T1 - T2

[0031] For generators, the calculation method is to add the torque matrix T2 due to iron loss to the torque matrix T1 that does not consider the iron loss effect:

[0032] T = T1 + T2

[0033] Furthermore, the method for obtaining the speed-torque envelope in step two is as follows:

[0034] A1. Calculate the current amplitude matrix i m_bu The calculation formula is: Use x to correspond to matrix i m_bu The position of column y corresponds to matrix i m_bu Given the position of the row and the rotational speed ω', calculate the current amplitude matrix i at that rotational speed. m_bu The current operating point that satisfies the current constraint and voltage constraint, along with the corresponding x and y values, are used as its position coordinates.

[0035] A2. Based on the position coordinates obtained in A1, the torque values ​​corresponding to all current operating points can be extracted from the torque matrix T considering the iron loss effect, and the maximum torque value and its position coordinates can be further extracted.

[0036] A3. Extract the iron loss value corresponding to the coordinate of the maximum torque value in the iron loss matrix of the full current condition corresponding to the speed ω', and calculate the copper loss based on the current value to obtain the maximum torque value that the motor can achieve at the speed ω' and the efficiency under this condition.

[0037] A4. By applying the above method to different speeds, the motor speed-torque envelope and the efficiency value at each point on the envelope can be obtained.

[0038] The voltage constraint mentioned above refers to the voltage amplitude being less than or equal to a given value, i.e., the existence of a voltage limit circle. The voltage amplitude U is calculated using the following formula:

[0039]

[0040] Among them, the d-axis voltage q-axis voltage

[0041] The copper loss P at the current operating point Cu The calculation formula is:

[0042]

[0043] Where Rs is the phase resistance of the motor.

[0044] Step 3 describes a method for searching the optimal efficiency current of a permanent magnet synchronous motor considering iron loss effects. This method is similar to the idea of ​​obtaining the motor speed-torque envelope. For example, given a speed ω' and a torque T', this operating condition lies within the motor speed-torque envelope. The specific method for searching the optimal efficiency current of the motor under this operating condition is as follows:

[0045] B1. For a given torque T', since the torque matrix T considering the iron loss effect is i d i q The function, in the torque matrix T, is represented by i. d i q By plotting contour lines of the required torque value on the x and y axes, the corresponding value of i at each point on the torque contour line can be directly obtained. d value,i q Values ​​(can be obtained using MATLAB contour functions);

[0046] B2. Using x' to correspond to the column position of matrix T and y' to correspond to the row position of matrix T, extract the x' and y' values ​​corresponding to each current operating point obtained in A1 above. These values ​​are used as the position coordinates of each point on the torque contour line in the torque matrix T. Based on these position coordinates, the iron loss matrix P under the given speed ω' is calculated. Fe_ω' (i d i q Extract the corresponding flux linkage and iron loss from ω'). The next step is to calculate the current amplitude corresponding to each current operating point mentioned above, and extract the current operating points that meet the current constraints and their corresponding flux linkage and iron loss;

[0047] B3. Using the current operating points and corresponding flux linkages extracted in B2 that meet the current constraints, calculate the voltage values ​​at a given speed ω' and a given torque T'. Further extract the current operating points and iron losses that meet the voltage constraints to obtain all currents that satisfy the constraints. Then calculate the copper losses of all remaining current operating points to obtain the total losses of each current operating point. Further, the current operating point that minimizes both iron and copper losses can be obtained, which is the truly efficient current operating point at a given speed ω' and a given torque T'.

[0048] The beneficial effects of this invention are:

[0049] (1) A saturated flux linkage model for a permanent magnet synchronous motor is provided, which fully considers the influence of nonlinear factors such as saturation and cross saturation on the motor and can be used to accurately calculate the actual dynamic characteristics of the motor during actual operation.

[0050] (2) A permanent magnet synchronous motor iron loss model based on speed scaling is provided, which can be constructed in parallel with the saturation flux linkage model. Finite element calculations are performed on a small number of current operating points at a certain speed. Given the speed, torque and current operating points, the iron loss of the corresponding operating conditions can be obtained accurately and quickly.

[0051] (3) A method for calculating motor torque that takes into account the iron loss effect is provided. When calculating torque using current and flux linkage, the influence of iron loss on torque is introduced, making the calculated current trajectory more accurate.

[0052] (4) A method for calculating and generating the efficiency MAP of a permanent magnet synchronous motor is provided. This method can accurately and quickly calculate the efficiency MAP of the motor under control modes such as optimal current control, MTPA, and field weakening. Only a small amount of finite element calculation is required, avoiding a large number of repeated experiments or finite element calculations. At the same time, the influence of iron loss effect on torque is considered in the calculation process, and the calculated efficiency MAP has high fidelity. Attached Figure Description

[0053] Figure 1 This is a flowchart of the method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to the present invention;

[0054] Figure 2 It is a saturated flux linkage model of a permanent magnet synchronous motor, where (a) is the d-axis flux linkage model and (b) is the q-axis flux linkage model;

[0055] Figure 3 It is a speed-scalable iron loss model, where (a) is a speed-scalable hysteresis loss model, (b) is a speed-scalable eddy current loss model, and (c) is a speed-scalable total iron loss model.

[0056] Figure 4It is the calculated speed-torque envelope of the permanent magnet synchronous motor and the selected operating point for calculation;

[0057] Figure 5 It is a torque matrix model under full current conditions that takes into account the effect of iron loss at a given speed;

[0058] Figure 6 This is a schematic diagram of the process of obtaining the optimal current operating point based on the idea of ​​torque calculation and extraction.

[0059] Figure 7 The motor efficiency MAP is calculated using the high-fidelity efficiency MAP rapid calculation generation method of the present invention for permanent magnet synchronous motors. Detailed Implementation

[0060] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0061] like Figures 1-7 As shown, this invention provides a method for rapidly calculating and generating high-fidelity efficiency MAPs for permanent magnet synchronous motors. It aims to solve the problems of high workload and high cost associated with traditional methods that require repeated and extensive calculations to obtain motor efficiency MAPs through experiments or finite element analysis, or the low fidelity of results when calculating efficiency MAPs using inductance or flux linkage models without considering the impact of iron loss on motor torque. Figure 1 The diagram shows a flowchart of the method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to the present invention. The method includes the following steps:

[0062] 1. Construct a saturated flux linkage model and an iron loss model that can be scaled based on rotational speed in parallel. Calculate the torque matrix model under full current conditions without considering the iron loss effect using the saturated flux linkage model.

[0063] 2. The motor speed is divided into equal intervals. Using a speed-scalable iron loss model, the iron loss matrix corresponding to the full current condition at each speed can be calculated. Further calculations are made of the torque matrix due to iron loss and the torque matrix considering the iron loss effect at each speed. The maximum torque achievable at each speed while satisfying the current and voltage limit circles is extracted to obtain the speed-torque envelope.

[0064] 3. Select the speed-torque combination required for calculating the efficiency MAP within the speed-torque envelope, and use the efficiency-optimal current search method for permanent magnet synchronous motor considering iron loss effect to search for the current operating point and corresponding iron loss for each operating condition and calculate the copper loss.

[0065] IV. Use the iron and copper losses from step three to generate an efficiency MAP.

[0066] The above process will now be explained in detail using a 4-pole, 48-slot permanent magnet synchronous motor as an example.

[0067] First, a saturation flux linkage model and a speed-scalable iron loss model are constructed in parallel. Within the range encompassing the motor current limit circle, the d-axis and q-axis currents are divided at equal or unequal intervals, or the current amplitude and phase angle are divided separately as selected current operating points. For example, if the current limit value is 21A, then the d-axis current i d It can be equally divided into (0, -3, -6, -9, -12, -15, -18, -21) (A), q-axis current i q The current can be equally divided into (0, 3, 6, 9, 12, 15, 18, 21) (A), resulting in a total of 8*8 = 64 discrete current operating points. However, unequal division can also be made according to actual needs, for example, the d-axis current i... d It can be divided into (0, -2, -7, -9, -13, -16, -18, -21) (A) at unequal intervals, with the q-axis current i q The interval can be unequally divided into (0, 2, 6, 10, 12, 17, 18, 21)(A). Using the finite element method at a certain speed ω, the discrete current operating points are calculated, simultaneously obtaining the d-axis and q-axis flux linkage matrices and the iron loss matrix at that speed. After matrix interpolation, the d-axis flux linkage matrix encompassing all current operating points within the motor current limit circle is obtained. q-axis flux linkage matrix And the iron loss matrix at that rotational speed, the iron loss matrix P Fe_ω (i d i q ,ω) includes the hysteresis loss matrix P Fe_hys_ω (i d i q ,ω) and eddy current loss P Fe_eddy_ω (i d i q The ω) matrix, namely the saturation flux linkage model and the iron loss model that can be scaled based on rotational speed, are respectively as follows: Figure 2 and Figure 3 As shown:

[0068]

[0069]

[0070] P Fe_hys_ω (i d i q ,ω)=P Fe_hys_ω (i m ,θ,ω)

[0071] P Fe_eddy_ω (i d i q ,ω)=P Fe_eddy_ω (i m ,θ,ω)

[0072] P Fe_ω (i d i q ,ω)=P Fe_ω (i m ,θ,ω)=P Fe_hys_ω (i d i q ,ω)+P Fe_eddy_ω (i d i q ,ω)

[0073] Where i d Let i be the d-axis current. q Let i be the q-axis current. m θ is the current amplitude, and θ is the current phase angle.

[0074] The current limit circle mentioned above refers to the maximum allowable current amplitude of the motor, where the current amplitude i is... m It can also be calculated from the d-axis and q-axis currents:

[0075]

[0076] Preferably, the torque matrix T1, which does not consider iron loss effect, mentioned in step one, is obtained by matrix calculation based on the d-axis flux linkage matrix and the corresponding constructed d-axis current matrix. The calculation formula is as follows:

[0077]

[0078] Where P is the number of pole pairs of the motor, i d_bu To construct the d-axis current matrix, i q_bu To construct the q-axis current matrix. Constructing the current matrix means that the current matrix corresponds to the saturation flux linkage matrix, the T1 matrix, and the iron loss matrix. Taking the flux linkage matrix as an example, i... d_bu and i q_bu The d-axis flux linkage and q-axis flux linkage generated by the d-axis current value and q-axis current value at any coordinate position are the d-axis and q-axis flux linkage values ​​corresponding to the same coordinate position in the saturation flux linkage matrix.

[0079] Furthermore, the iron loss matrix P under any given rotational speed ω' described in step two... Fe_ω' (i d i q The formula for calculating ω') is obtained from the iron loss model that can be scaled based on rotational speed obtained in step one.

[0080]

[0081]

[0082] PFe_ω' (i d i q ,ω')=P Fe_hys_ω' (i d i q ,ω')+P Fe_eddy_ω' (i d i q ,ω')

[0083] Preferably, at a given rotational speed ω', the torque matrix T2 due to iron loss in step two is obtained using the iron loss matrix P. Fe_ω' The calculation is as follows:

[0084] T2 = P Fe_ω' / ω'

[0085] Therefore, for an electric motor, at a given speed ω', the torque matrix T considering the iron loss effect described in step two is calculated by subtracting the torque matrix T2 due to iron loss from the torque matrix T1 that does not consider the iron loss effect:

[0086] T = T1 - T2

[0087] For generators, the calculation method is to add the torque matrix T2 due to iron loss to the torque matrix T1 that does not consider the iron loss effect:

[0088] T = T1 + T2

[0089] The above method can be used to obtain the total current torque matrix considering iron loss at any speed. Furthermore, the motor speed-torque envelope is calculated:

[0090] A1. Calculate the current amplitude matrix i m_bu The calculation formula is: Use x to correspond to matrix i m_bu The position of column y corresponds to matrix i m_bu Given the position of the row and the rotational speed ω', calculate the current amplitude matrix i at that rotational speed. m_bu The current operating point that satisfies the current constraint and voltage constraint and its corresponding x and y values ​​are used as its position coordinates.

[0091] A2. Based on the position coordinates obtained in A1, the torque values ​​corresponding to all current operating points can be extracted from the torque matrix T considering the iron loss effect, and the maximum torque value and its position coordinates can be further extracted.

[0092] A3. Extract the iron loss value corresponding to the coordinate of the maximum torque value in the iron loss matrix of the full current condition corresponding to the speed ω', and calculate the copper loss based on the current value to obtain the maximum torque value that the motor can achieve at the speed ω' and the efficiency under this condition.

[0093] A4. By applying the above method to different speeds, the motor speed-torque envelope and the efficiency value at each point on the envelope can be obtained.

[0094] The voltage constraint mentioned above refers to the voltage amplitude being less than or equal to a given value, i.e., the existence of a voltage limit circle. The voltage amplitude U is calculated using the following formula:

[0095]

[0096] Among them, the d-axis voltage q-axis voltage

[0097] The copper loss P at the current operating point Cu The calculation formula is:

[0098]

[0099] Where Rs is the phase resistance of the motor.

[0100] Taking this motor as an example again, the speed is divided into 100 rpm increments. The motor speed-torque envelope is calculated according to the A1-A4 method. Then, the maximum torque value at each speed is divided into 40 equal parts as the operating points required to calculate the efficiency MAP. The resulting motor speed-torque envelope and the selected operating points within the envelope are shown below. Figure 5 As shown.

[0101] Next, the efficiency-optimal current search method for permanent magnet synchronous motors considering iron loss effect is used to search and calculate the efficiency at each operating point within the envelope. This current search method is similar to the idea of ​​obtaining the motor speed-torque envelope. For example, given a speed ω' and a torque T', this operating condition is within the motor speed-torque envelope. The specific method for searching the motor's efficiency-optimal current under this operating condition is as follows:

[0102] B1. For a given torque T', since the torque matrix T considering the iron loss effect is i d i q The function, in matrix T, with i d i q By plotting contour lines of the required torque values ​​on the horizontal and vertical axes, the corresponding values ​​of i at each point on the torque contour lines can be directly obtained. d value,i q Values ​​(can be obtained using MATLAB contour functions);

[0103] B2. Using x' to correspond to the column position of matrix T and y' to correspond to the row position of matrix T, extract the x' and y' values ​​corresponding to each current operating point obtained in A1 above. These values ​​are used as the position coordinates of each point on the torque contour line in the torque matrix T. Based on these position coordinates, the iron loss matrix P under the given speed ω' is calculated. Fe_ω' (id i q Extract the corresponding flux linkage and iron loss from ω'). The next step is to calculate the current amplitude corresponding to each current operating point mentioned above, and extract the current operating points that meet the current constraints and their corresponding flux linkage and iron loss;

[0104] B3. Using the current operating points and corresponding flux linkages extracted in B2 that meet the current constraints, calculate the voltage values ​​at a given speed ω' and a given torque T'. Further extract the current operating points and iron losses that meet the voltage constraints to obtain all currents that satisfy the constraints. Then calculate the copper losses of all remaining current operating points to obtain the total loss at each current point. Further, the current operating point that minimizes both iron and copper losses can be obtained, which is the truly efficient current operating point at a given speed ω' and a given torque T'.

[0105] For example, in this case, at a speed of 1000 rpm, the motor current limit is 21A and the voltage limit is 100V. The torque matrix calculated for the motor at this speed, taking into account iron loss, is as follows: Figure 5 As shown, to make the current search method more intuitive, the following can be calculated: Figure 6 The current limit circle and voltage limit circle are shown. The current operating points corresponding to the torque contour lines in the shaded area are all feasible current operating points under the condition of 1000 rpm speed and 6 N·m torque.

[0106] Furthermore, by calculating the copper losses at all current operating points that satisfy the constraints, we can obtain the current operating point that minimizes both iron and copper losses, i.e., the current operating point with optimal efficiency at a given speed ω' and a given torque T'. In this example, the current operating point with optimal efficiency at a given speed of 1000 rpm and a given torque of 6 N·m is as follows: Figure 6 As shown, the current value is i d =-6.9, i q =8.6.

[0107] The methods described in B1-B3 can be used to calculate the efficiency at all operating points within the motor speed-torque envelope, thereby obtaining the motor efficiency MAP, as shown below. Figure 7 As shown.

[0108] The method of this invention takes into account the influence of iron loss on torque when calculating the current operating point, making the searched current trajectory more accurate and the efficiency MAP diagram more faithful. In addition, by using the matrix calculation extraction idea proposed in this invention, the current extraction point with the minimum loss described in this paper is changed to the current operating point with the minimum current amplitude under the limiting voltage circle limit. It can also quickly calculate and search the current trajectory of ordinary MTPA or field weakening control methods.

[0109] Finally, it should be noted that the above are only specific embodiments of the present invention. Of course, those skilled in the art can make modifications and variations to the present invention. If these modifications and variations fall within the scope of the claims of the present invention and their equivalents, they should be considered as being within the protection scope of the present invention.

Claims

1. A method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors, characterized in that, Includes the following steps: Step 1: Construct a saturated flux linkage model and an iron loss model that can be scaled based on rotational speed in parallel. Use the saturated flux linkage model to calculate the torque matrix model under the full current condition without considering the iron loss effect. Step 2: Divide the motor speed at equal intervals. Using the iron loss model that can be scaled based on the speed, the iron loss matrix corresponding to the full current condition at each speed can be calculated. Further calculate the torque matrix due to iron loss and the torque matrix considering the iron loss effect at each speed. Extract the maximum torque that can be achieved at each speed while satisfying the current limit circle and the voltage limit circle to obtain the motor speed-torque envelope. Step 3: Select the speed-torque combination required for calculating the efficiency MAP within the speed-torque envelope, and use the efficiency-optimal current search method for permanent magnet synchronous motors considering iron loss effect to search for the current operating point and corresponding iron loss for each operating condition and calculate the copper loss. Step 4: Generate an efficiency MAP using the iron and copper losses from Step 3; The construction process of the saturated flux linkage model and the speed-scalable iron loss model described in step one is as follows: Within the range encompassing the motor current limit circle, the d-axis current and q-axis current are divided at equal or unequal intervals, or the current amplitude and phase angle are divided as selected current operating points; the selected current operating points are calculated using the finite element method at a certain speed ω, and the d-axis flux linkage matrix, q-axis flux linkage matrix, and iron loss matrix at that speed are obtained simultaneously. The matrices are interpolated to obtain the d-axis flux linkage matrix encompassing all current operating points within the motor current limit circle. q-axis flux linkage matrix and the iron loss matrix P at that rotational speed Fe_ω (i d i q The iron loss matrix includes the hysteresis loss matrix P. Fe_hys_ω (i d i q ,ω) and eddy current loss P Fe_eddy_ω (i d i q The matrix (ω) represents the saturation flux linkage model and the iron loss model that can be scaled based on rotational speed: P Fe_hys_ω (i d ,i q ,ω)=P Fe_hys_ω (i m ,θ,ω) P Fe_eddy_ω (i d ,i q ,ω)=P Fe_eddy_ω (i m ,θ,ω) P Fe_ω (i d ,i q ,ω)=P Fe_ω (i m ,θ,ω)=P Fe_hys_ω (i d ,i q ,ω)+P Fe_eddy_ω (i d ,i q ,ω) Where i d Let i be the d-axis current. q Let i be the q-axis current. m θ is the current amplitude, and θ is the current phase angle; In step two, the iron loss matrix corresponding to the full current condition at each speed is calculated using an iron loss model that can be scaled based on rotational speed. The calculation formula is as follows: P Fe_ω' (i d ,i q ,ω')=P Fe_hys_ω' (i d ,i q ,ω')+P Fe_eddy_ω' (i d ,i q ,ω') This formula can be used to calculate the iron loss matrix under the full current condition with arbitrary division of speed ω'; At a given rotational speed ω', the torque matrix T2 due to iron loss mentioned in step two is obtained using the iron loss matrix P. Fe_ω' The calculation is as follows: T2=P Fe_ω' / oh' For an electric motor, at a given speed ω', the torque matrix T considering iron loss in step two is calculated by subtracting the torque matrix T2 due to iron loss from the torque matrix T1 that does not consider iron loss: T = T1 - T2 For generators, the calculation method is to add the torque matrix T2 due to iron loss to the torque matrix T1 that does not consider the iron loss effect: T = T1 + T2; The method for obtaining the speed-torque envelope in step two is as follows: Step A1: Calculate the current amplitude matrix i m_bu The calculation formula is: Use x to correspond to matrix i m_bu The column position, y corresponds to matrix i m_bu Given the position of the row and the rotational speed ω', calculate the current amplitude matrix i at that rotational speed. m_bu The current operating point that satisfies the current constraint and voltage constraint, along with the corresponding x and y values, are used as its position coordinates. Step A2: Based on the position coordinates obtained in Step A1, the torque values ​​corresponding to all current operating points can be extracted from the torque matrix T considering the iron loss effect, and the maximum torque value and its position coordinates can be further extracted. Step A3: Extract the iron loss value corresponding to the coordinate of the maximum torque value in the iron loss matrix of the full current condition corresponding to the speed ω', and calculate the copper loss according to the current value. Then you can obtain the maximum torque value that the motor can achieve at the speed ω' and the efficiency under this condition. Step A4: By applying the above method to different speeds, the motor speed-torque envelope and the efficiency value at each point on the envelope can be obtained.

2. The method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to claim 1, characterized in that: The current limit circle refers to the maximum allowable current amplitude of the motor, where the current amplitude i is... m It can also be calculated from the d-axis current and q-axis current:

3. The method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to claim 1, characterized in that: The torque matrix T1 under the full current condition, which does not consider iron loss, described in step one, is obtained through matrix calculation based on the d-axis flux linkage matrix, the q-axis flux linkage matrix, and the corresponding current matrix. The calculation formula is as follows: Where P is the number of pole pairs of the motor, i d_bu To construct the d-axis current matrix, i q_bu To construct the q-axis current matrix; the so-called constructed corresponding current matrix means that the current matrix corresponds to the saturation flux linkage matrix, T1 matrix and iron loss matrix.

4. The method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to claim 1, characterized in that: The voltage constraint means that the voltage amplitude must be less than or equal to a given value, i.e., there exists a voltage limit circle; the voltage amplitude U is calculated according to the following formula: Among them, the d-axis voltage q-axis voltage The copper loss P at the current operating point Cu The calculation formula is: Where Rs is the phase resistance of the motor.

5. The method for rapid calculation and generation of high-fidelity efficiency MAP for permanent magnet synchronous motors according to claim 1, characterized in that: The method for searching the optimal efficiency current of the permanent magnet synchronous motor considering iron loss in step three is still under the operating condition of a given speed ω' and a given torque T'. This operating condition is located within the motor speed-torque envelope. The specific method for searching the optimal efficiency current of the motor under this operating condition is as follows: B1. For a given torque T', since the torque matrix T considering the iron loss effect is i d i q The function, in the torque matrix T, is represented by i. d x-coordinate, i q By plotting contour lines of the required torque values ​​on the vertical axis, the corresponding values ​​of i at each point on the torque contour lines can be directly obtained. d value,i q value; B2. Using x' to correspond to the column position of matrix T and y' to correspond to the row position of matrix T, extract the x' and y' values ​​corresponding to each current operating point obtained in step A1. These values ​​are used as the position coordinates of each point on the torque contour line in the torque matrix T. Based on these position coordinates, calculate the iron loss matrix P under the saturation flux linkage model matrix and the given speed ω'. Fe_ω' (i d i q Extract the corresponding flux linkage and iron loss from ω'); the next step is to calculate the current amplitude corresponding to each current operating point mentioned above, and extract the current operating point that meets the current constraint and the corresponding flux linkage and iron loss. B3. Using the current operating points and corresponding flux linkages that meet the current constraints extracted in step B2, calculate the voltage values ​​at a given speed ω' and a given torque T'. Further extract the current operating points and iron losses that meet the voltage constraints to obtain all currents that satisfy the constraints. Then calculate the copper losses of all remaining current operating points to obtain the total losses of each current operating point. Further, the current operating point that minimizes both iron and copper losses can be obtained, which is the truly efficient current operating point at a given speed ω' and a given torque T'.

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