Real-time distribution method for torque of inner and outer stators of double-stator motor

Abstract

The invention relates to the field of motor control, and discloses a double-stator motor inner and outer stator torque real-time distribution method, which comprises the following steps: establishing an outer stator motor efficiency model according to the torque and the rotating speed of an outer stator motor and the copper loss and the iron loss of the outer stator motor; establishing an inner stator motor efficiency model according to the torque and the rotating speed of the inner stator motor and the copper loss and the iron loss of the inner stator motor; based on the outer stator motor efficiency model and the inner stator motor efficiency model, establishing a double-stator motor overall efficiency model containing a torque distribution coefficient; under the current constraint condition of the outer stator motor and the inner stator motor, the overall efficiency model of the double-stator motor is maximized based on a sequential quadratic programming algorithm, and the optimal torque distribution coefficient is obtained. According to the method, the efficiency model of the motor can be reasonably constructed, the torque distribution coefficient is optimized in real time, the torque of the double-stator motor is dynamically adjusted, and the energy loss in the operation process is reduced on the basis of meeting the operation efficiency of the motor.

Description

Technical Field

[0001] The invention relates to the field of motor control, and in particular to a real-time distribution method of inner and outer stator torques in a dual-stator motor. Background Art

[0002] The two stators of the dual-stator motor can form a rotating magnetic field, which is flexible to control and covers a wide range of efficient operation areas. The intermediate rotor of the dual-stator motor is subjected to two mutually offsetting magnetic pulls, which has the characteristics of more stable structure and smaller mechanical loss. It is suitable for places with high efficiency and high torque density, and has a wide range of applications in electric vehicles, wind power generation, etc. Therefore, it is of great significance to study the stable and efficient torque distribution strategy of the dual-stator motor.

[0003] Although domestic and foreign scholars have conducted some research on the control strategy of multi-motor systems, there are few studies on the internal and external torque distribution strategy of dual-stator motors, especially the lack of research on the real-time and efficient distribution strategy of the system, which limits the promotion of dual-stator motors. Traditional multi-power source systems generally use proportional distribution, but this method ignores the problem of system efficiency; traditional dual-stator motor internal and external stator torque distribution methods include distribution methods based on motor efficiency MAP diagrams. This control is too dependent on the measurement of motor parameters, and the effectiveness of the distribution is related to the fitting effect of the MAP diagram, which has certain limitations.

[0004] The patent document with publication number CN 107783038 A discloses a test and calculation method for the efficiency of a doubly-fed wind turbine generator, which calculates the stator copper loss, stator iron loss, rotor copper loss, rotor iron loss, and mechanical loss of the generator, respectively, thereby obtaining the total loss of the generator. The mechanical loss is obtained by adjusting the stator frequency of the generator using a frequency-modulated power supply so that the generator rotor speed reaches the rated speed, and then performing a no-load characteristic test to obtain the no-load mechanical loss; the stator iron loss is obtained by calculating the no-load voltage corresponding to the stator iron loss of the no-load characteristic test using the equivalent circuit parameters and rated voltage of the generator, thereby obtaining the stator iron loss using the no-load characteristic test data at the rated frequency.

[0005] The patent document with publication number CN 111614298 A discloses a torque decoupling vector control method for a hybrid rotor dual-stator synchronous motor, which introduces an outer stator torque decoupling coefficient and an inner stator torque decoupling coefficient to achieve separate control of the output torque of the inner and outer stator windings of the dual-stator synchronous motor. The existing dual-stator motor torque distribution method does not consider the impact of the copper loss and iron loss of the stator motor on the motor efficiency, and cannot achieve real-time distribution according to the overall motor efficiency. The existing dual-stator motor torque distribution method does not fully consider the copper loss and iron loss of the stator motor during operation. Both losses directly affect the efficiency and performance of the motor; and the existing technology cannot dynamically adjust the torque distribution strategy, and cannot distribute the stator torque in real time according to the current efficiency of the motor.

[0006] The patent document with publication number CN 116070371 A discloses a dual-stator motor design method, which includes: determining the variables to be optimized in the motor design, establishing the optimization objective function, the variables to be optimized include torque pulsation, total material cost and heat load flux; determining the motor boundary conditions and the types of parameters to be optimized; using the optimization algorithm to set the convergence conditions of the parameters to be optimized, calculating the motor line voltage, output torque and magnetic flux density parameters, obtaining the calculation results, and determining the values ​​of each parameter to be optimized according to the calculation results. The existing dual-stator motor torque design method involves multiple technical parameters and performance indicators. The adjustment of each parameter will have a direct impact on the performance of the motor, and it needs to be finely adjusted according to different optimization goals. The entire design process relies on complex calculation models and experimental verification, which is relatively cumbersome. Summary of the invention

[0007] The purpose of the present invention is to provide a real-time distribution method of the internal and external stator torques of a dual-stator motor, which can dynamically adjust the stator torque according to the real-time state of the motor, reduce the energy loss during the operation of the dual-stator motor, and improve the operating efficiency of the dual-stator motor.

[0008] A method for real-time distribution of internal and external stator torques of a dual-stator motor, comprising:

[0009] Step 1: Establish an efficiency model of the external stator motor according to the torque, speed, copper loss and iron loss of the external stator motor;

[0010] Step 2: Establish an efficiency model of the inner stator motor according to the torque, speed, copper loss and iron loss of the inner stator motor;

[0011] Step 3: Based on the outer stator motor efficiency model and the inner stator motor efficiency model, establish a dual-stator motor overall efficiency model including a torque distribution coefficient;

[0012] Step 4: Under the current constraints of the outer stator motor and the inner stator motor, based on the sequential quadratic programming algorithm, the overall efficiency model of the dual-stator motor is maximized to obtain the optimal torque distribution coefficient for real-time distribution of the torque of the inner and outer stators.

[0013] Furthermore, in step 1, the process of establishing the external stator motor efficiency model is specifically as follows:

[0014] (1-1) The output power of the external stator motor is P out1 =τ m1 ω, where τ m1 is the external stator motor torque, ω is the motor speed;

[0015] (1-2) The input power of the external stator motor is P in1=P out1 +P Loss1 , where P Loss1 is the total power loss of the external stator motor;

[0016] Ignoring a small proportion of additional losses, the total power loss of the external stator motor is the copper loss P of the external stator motor. Cu1 and iron loss P Fe1 The sum of P Loss1 =P Cu1 +P Fe1 ,The establishment of copper loss and iron loss models can quickly parameterize the model, reducing the computational complexity, which is beneficial to improving the real-time performance of torque coefficient optimization;

[0017] Furthermore, the outer stator motor copper loss P Cu1 It can be expressed as:

[0018]

[0019] Among them, κ is the number of phases of the dual-stator motor, I1 is the external stator motor current, and R1 is the external stator motor resistance;

[0020] External stator motor iron loss P Fe1 It can be expressed as:

[0021]

[0022] Among them, m1 is the mass of the outer stator motor core, K h1 is the hysteresis loss coefficient of the external stator motor, K c1 is the eddy current loss coefficient of the external stator motor, K e1 is the additional loss coefficient of the external stator motor, α1 is the coefficient of the associated hysteresis loss of the external stator motor, B1 is the amplitude of the sinusoidal magnetic flux density of the external stator motor, f = p m ω / (2π) is the frequency of the sinusoidal magnetic flux density, p m is the number of pole pairs of a double-stator motor;

[0023] (1-3) The external stator motor efficiency model η1 can be expressed as:

[0024]

[0025] Among them, k t1 is the external stator motor torque constant.

[0026] Furthermore, in step 2, the process of establishing the inner stator motor efficiency model is specifically as follows:

[0027] (2-1) The output power of the inner stator motor is P out2 =τ m2 ω, where τ m2is the torque of the inner stator motor; the inner stator and the outer stator share an output rotor, so the speed of the inner stator motor is the same as that of the outer stator motor, both of which are ω;

[0028] (2-2) The input power of the inner stator motor is P in2 =P out2 +P Loss2 , where P Loss2 is the total power loss of the inner stator motor;

[0029] The total power loss of the inner stator motor is the copper loss P of the inner stator motor. Cu2 and iron loss P Fe2 The sum of P Loss2 =P Cu2 +P Fe2 ;

[0030] Furthermore, the internal stator motor copper loss P Cu2 It can be expressed as:

[0031]

[0032] Among them, I2 is the internal stator motor current, R2 is the internal stator motor resistance;

[0033] Internal stator motor iron loss P Fe2 It can be expressed as:

[0034]

[0035] Among them, m2 is the mass of the inner stator motor core, K h2 is the internal stator motor hysteresis loss coefficient, K c2 is the eddy current loss coefficient of the internal stator motor, K e2 is the additional loss coefficient of the inner stator motor, α2 is the coefficient of the associated hysteresis loss of the inner stator motor, B2 is the amplitude of the sinusoidal magnetic flux density of the inner stator motor, f=p m ω / (2π) is the frequency of the sinusoidal magnetic flux density, p m is the number of pole pairs of a double-stator motor;

[0036] (2-3) The inner stator motor efficiency model η2 can be expressed as:

[0037]

[0038] Among them, k t2 is the internal stator motor torque constant.

[0039] Furthermore, in step 3, the process of establishing the overall efficiency model of the dual-stator motor is specifically as follows:

[0040] (3-1) The overall efficiency model η of the dual-stator motor can be expressed as:

[0041]

[0042] The total torque of the motor is τ m =τ m1 +τ m2 , the torque distribution coefficient is k d =τ m1 / τ m , so the torque of the external stator motor is τ m1 =k d τ m , the torque of the inner stator motor is τ m2 =(1-k d )τ m , the external stator motor current is I1 = k d τ m / k t1 , the internal stator motor current is I2 = (1-k d )τ m / k t2 .

[0043] Based on the outer stator motor efficiency model and the inner stator motor efficiency model established in step 1 and step 2, the overall efficiency model η of the dual-stator motor is further expressed as:

[0044]

[0045] in,

[0046]

[0047]

[0048] The inner and outer stators share an output rotor, and the motor speed ω is the same. Therefore, the torque distribution of the outer stator and the inner stator is achieved by distributing the output power of the outer stator and the inner stator.

[0049] Furthermore, in step 4, the specific steps of the dual-stator motor torque distribution coefficient optimization process are as follows:

[0050] (4-1) Based on the sequential quadratic programming algorithm, the overall efficiency model η of the dual-stator motor is maximized under the current constraints of the outer stator motor and the inner stator motor:

[0051]

[0052] st

[0053] 0≤k d τ m / k t1 ≤10

[0054] 0≤(1-k d )τ m / k t2 ≤8

[0055] 0≤k d ≤1

[0056] Among them, Φ i =[K hi ,K ci ,K ei ,B i ,α i ,R i ], i = 1, 2; i = 1 represents the parameters of the outer stator motor, and i = 2 represents the parameters of the inner stator motor.

[0057] The undetermined parameters Φ1 of the outer stator motor and Φ2 of the inner stator motor are identified by the lsqnonlin function in Matlab; the total torque τ of the dual-stator motor at any time m and motor speed ω, to obtain the optimal torque distribution coefficient k at that moment d Based on the torque distribution coefficient, the torque of the outer stator and the inner stator is adjusted so that the motor maintains optimal efficiency under different operating conditions.

[0058] Beneficial effects of the present invention: Compared with the prior art, the present invention adds the calculation of copper loss and iron loss to the efficiency model of the dual-stator motor, so that the efficiency model can reflect the influence of the motor loss parameters on the motor operation, and reduce the energy loss during the operation process on the basis of meeting the motor operation efficiency; at the same time, the present invention maximizes the overall efficiency model of the dual-stator motor through a sequential quadratic programming algorithm, optimizes the optimal torque distribution coefficient in real time according to the constantly changing total torque of the motor and the motor speed, and dynamically adjusts the torque of the dual-stator motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of the structure of a dual-stator motor in an embodiment of the present invention, wherein: Figure 1 (a) Main view, Figure 1 (b) is a three-dimensional image;

[0060] Figure 2 is a flow chart of a method for real-time torque distribution of a dual-stator motor in an embodiment of the present invention;

[0061] Figure 3 is a diagram of the actually measured efficiency and model calculated efficiency of the stator in the double-stator motor in an embodiment of the present invention;

[0062] Figure 4 1 is a diagram showing the measured efficiency and model calculated efficiency of the outer stator of a double-stator motor in an embodiment of the present invention;

[0063] Figure 5 is a real-time motor speed and motor torque diagram of a dual-stator motor in an embodiment of the present invention;

[0064] Figure 6 is a comparison diagram of the torque distribution coefficient of the dual-stator motor before and after optimization in an embodiment of the present invention;

[0065] Figure 7 It is a comparison diagram of the real-time operating efficiency of the dual-stator motor before and after optimization in an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0067] Figure 1 (a) is a front view of a dual-stator motor according to an embodiment of the present invention, Figure 1 (b) is a three-dimensional graph. Figure 1 As shown, a double-stator motor includes an outer stator 1, a cup-shaped rotor 2 and an inner stator 3 from the outside to the inside; the outer stator 1, the cup-shaped rotor 2 and the inner stator 3 are coaxially sleeved and independent of each other, and the cup-shaped rotor 2 can rotate relative to the outer stator 1 and the inner stator 3; an outer air gap is provided between the outer stator 1 and the cup-shaped rotor 2, and an inner air gap is provided between the cup-shaped rotor 2 and the inner stator 3.

[0068] like Figure 2 As shown, a method flow for real-time torque distribution of a dual-stator motor in this embodiment includes the following steps:

[0069] S101, the output power of the external stator motor is P out1 =τ m1 ω, where τ m1 is the external stator motor torque, ω is the motor speed;

[0070] S102, external stator motor input power is P in1 =P out1 +P Loss1 , where P Loss1 is the total power loss of the external stator motor;

[0071] Ignoring a small proportion of additional losses, the total power loss of the external stator motor is the copper loss P of the external stator motor. Cu1 and iron loss P Fe1 The sum of P Loss1 =P Cu1 +P Fe1,The establishment of copper loss and iron loss models can quickly parameterize the model, reducing the computational complexity, which is beneficial to improving the real-time performance of torque coefficient optimization;

[0072] External stator motor copper loss P Cu1 It can be expressed as:

[0073]

[0074] Among them, κ is the number of phases of the dual-stator motor, I1 is the external stator motor current, and R1 is the external stator motor resistance;

[0075] External stator motor iron loss P Fe1 It can be expressed as:

[0076]

[0077] Among them, m1 is the mass of the outer stator motor core, K h1 is the hysteresis loss coefficient of the external stator motor, K c1 is the eddy current loss coefficient of the external stator motor, K e1 is the additional loss coefficient of the external stator motor, α1 is the coefficient of the associated hysteresis loss of the external stator motor, B1 is the amplitude of the sinusoidal magnetic flux density of the external stator motor, f = p m ω / (2π) is the frequency of the sinusoidal magnetic flux density, p m is the number of pole pairs of the double-stator motor;

[0078] S103, the external stator motor efficiency model η1 can be expressed as:

[0079]

[0080] Among them, k t1 is the torque constant of the external stator motor.

[0081] S201, the output power of the inner stator motor is P out2 =τ m2 ω, where τ m2 is the torque of the inner stator motor; the inner stator and the outer stator share an output rotor, so the speed of the inner stator motor is the same as that of the outer stator motor, both of which are ω;

[0082] S202, the input power of the inner stator motor is P in2 =P out2 +P Loss2 , where P Loss2 is the total power loss of the inner stator motor;

[0083] The total power loss of the inner stator motor is the copper loss P of the inner stator motor. Cu2 and iron loss P Fe2 The sum of P Loss2 =PCu2 +P Fe2 ;

[0084] Internal stator motor copper loss P Cu2 It can be expressed as:

[0085]

[0086] Among them, I2 is the internal stator motor current, R2 is the internal stator motor resistance;

[0087] Internal stator motor iron loss P Fe2 It can be expressed as:

[0088]

[0089] Among them, m2 is the mass of the inner stator motor core, K h2 is the internal stator motor hysteresis loss coefficient, K c2 is the eddy current loss coefficient of the internal stator motor, K e2 is the additional loss coefficient of the inner stator motor, α2 is the coefficient of the associated hysteresis loss of the inner stator motor, B2 is the amplitude of the sinusoidal magnetic flux density of the inner stator motor, f=p m ω / (2π) is the frequency of the sinusoidal magnetic flux density, p m is the number of pole pairs of the double-stator motor;

[0090] S203, the inner stator motor efficiency model η2 can be expressed as:

[0091]

[0092] Among them, k t2 is the internal stator motor torque constant.

[0093] S301. The overall efficiency model η of the dual-stator motor can be expressed as:

[0094]

[0095] The total torque of the motor is τ m =τ m1 +τ m2 , the torque distribution coefficient is k d =τ m1 / τ m , so the torque of the external stator motor is τ m1 =k d τ m , the torque of the inner stator motor is τ m2 =(1-k d )τ m , the external stator motor current is I1 = k d τ m / k t1, the internal stator motor current is I2 = (1-k d )τ m / k t2 , the outer stator motor efficiency model and the inner stator motor efficiency model established in S103 and S203 are substituted into the above formula, and the overall efficiency model η of the dual-stator motor is further expressed as:

[0096]

[0097] in,

[0098]

[0099]

[0100] The inner and outer stators share an output rotor, and the motor speed ω is the same. Therefore, the torque distribution of the outer stator and the inner stator is achieved by distributing the output power of the outer stator and the inner stator.

[0101] S401, based on the sequential quadratic programming algorithm, the overall efficiency model η of the dual-stator motor is maximized under the current constraints of the outer stator motor and the inner stator motor:

[0102]

[0103] st

[0104] 0≤k d τ m / k t1 ≤10

[0105] 0≤(1-k d )τ m / k t2 ≤8

[0106] 0≤k d ≤1

[0107] Among them, Φ i =[K hi ,K ci ,K ei ,B i ,α i ,R i ], i = 1, 2; i = 1 represents the parameters of the outer stator motor, and i = 2 represents the parameters of the inner stator motor.

[0108] Read the total torque τ of the dual-stator motor at each sampling moment m and motor speed ω, are substituted into the overall efficiency model of the dual-stator motor, and the torque distribution coefficient k corresponding to the sampling time is obtained based on the sequential quadratic programming algorithm dTherefore, under different motor total torques and motor speeds, the optimal torque distribution coefficient can be obtained, so that the motor maintains optimal efficiency under different operating conditions.

[0109] Figure 3 This is the real-time efficiency data of the external stator motor measured by the YOKOGAWA WT1800 high-performance power analyzer in this embodiment.

[0110] The actual measurement process of the external stator motor efficiency data is as follows:

[0111] 1. Set the control mode of the driver controlling the outer stator motor to the speed loop, and at the same time, cut off the current in the driver controlling the inner stator motor; set the motor speed to 209.44 rad / s, maintain a constant speed, and apply 7 different, successively increasing loads to the motor output end; based on the power analyzer, obtain the outer stator motor efficiency data corresponding to the 7 loads at a constant speed; change the motor speed to 314.16 rad / s and 418.88 rad / s respectively, apply the 7 loads to the motor output end, and obtain the 21 sets of outer stator motor efficiency data in Table 1:

[0112] Table 1: Measured efficiency data of external stator motor

[0113]

[0114] 2. The number of pole pairs of the dual-stator motor in this embodiment is p m =10; the i-th motor speed ω(i) and motor torque τ m1 (i) Substitute into the external stator motor efficiency model η1(i) established in S103, and denote the i-th measured efficiency of the external stator motor as η c1 (i) Based on the lsqnonlin function in Matlab, the unknown parameters of the external stator motor can be identified as Φ1 = [K h1 ,K c1 ,K e1 ,B1,α1,R1]; the parameters to be determined include the hysteresis loss coefficient K of the external stator motor h1 、Eddy current loss coefficient K of external stator motor c1 , Additional loss coefficient K of external stator motor e1 , the sinusoidal flux density amplitude B1 of the external stator motor, the coefficient of the hysteresis loss associated with the external stator motor α1, and the resistance value R1 of the copper wire winding of the external stator motor. By minimizing the sum of squares of the errors between the measured efficiency of the external stator motor and the calculated value of the S103 external stator motor efficiency model, the parameters to be determined can be identified. The identification formula is as follows:

[0115]

[0116] Where n = 21. Table 2 shows the parameters in the identified external stator motor efficiency model:

[0117] Table 2: Parameters in the identified external stator motor efficiency model

[0118] parameter <![CDATA[K h1 ]]> <![CDATA[K c1 ]]> <![CDATA[K e1 ]]> <![CDATA[B1]]> <![CDATA[α1]]> <![CDATA[R1]]> Numeric 0.142 <![CDATA[7.5ⅹ10 -5 ]]> 0.011 1.11 1.39 0.234 unit / / / T / Ω

[0119] like Figure 3 As shown in the figure, the measured data of the external stator efficiency is basically consistent with the data calculated by the external stator efficiency model, which verifies the accuracy of the external stator motor efficiency model.

[0120] Figure 4 This is the real-time efficiency data of the inner stator motor measured by the YOKOGAWA WT1800 high-performance power analyzer in this embodiment.

[0121] The actual measurement process of the internal stator motor efficiency data is as follows:

[0122] 1. Set the control mode of the driver controlling the inner stator motor to the speed loop, and at the same time, cut off the current in the driver controlling the outer stator motor; set the motor speed to 209.44 rad / s, maintain a constant speed, and apply 7 different, successively increasing loads to the motor output end; based on the power analyzer, obtain the inner stator motor efficiency data corresponding to the 7 loads at a constant speed; change the motor speed to 314.16 rad / s and 418.88 rad / s respectively, apply the 7 loads to the motor output end, and obtain the 21 groups of inner stator motor efficiency data in Table 3:

[0123] Table 3: Measured efficiency data of internal stator motor

[0124]

[0125]

[0126] 2. Record the motor speed ω(i) and the motor torque τ m2 (i) Substitute into the internal stator motor efficiency model η2(i) established in S203, and record the i-th measured efficiency of the internal stator motor as η c2 (i) Based on the lsqnonlin function in Matlab, the unknown parameters of the inner stator motor can be identified as Φ2 = [K h2 ,K c2 ,K e2 ,B2,α2,R2]; the parameters to be determined include the hysteresis loss coefficient K of the internal stator motor h2 、Eddy current loss coefficient K of internal stator motor c2 , additional loss coefficient K of internal stator motor e2, the sinusoidal magnetic flux density amplitude B2 of the inner stator motor, the coefficient of the hysteresis loss associated with the inner stator motor α2, and the resistance value R2 of the copper wire winding of the inner stator motor. By minimizing the sum of squares of the errors between the measured efficiency of the inner stator motor and the calculated value of the S203 inner stator motor efficiency model, the parameters to be determined can be identified. The identification formula is as follows:

[0127]

[0128] Where n = 21. Table 4 shows the parameters to be identified in the internal stator motor efficiency model:

[0129] Table 4: Parameters in the identified inner stator motor efficiency model

[0130] parameter <![CDATA[K h2 ]]> <![CDATA[K c2 ]]> <![CDATA[K e2 ]]> <![CDATA[B2]]> <![CDATA[α2]]> <![CDATA[R2]]> Numeric 0.036 <![CDATA[1.7ⅹ10 -5 ]]> 0.022 1.442 3.838 0.150 unit / / / T / Ω

[0131] like Figure 4 As shown in the figure, the measured data of the inner stator efficiency is basically consistent with the data calculated by the inner stator efficiency model, which verifies the accuracy of the inner stator motor efficiency model.

[0132] Figure 5 The real-time motor speed and motor torque diagram of the dual-stator motor in this embodiment. A set of real-time changes in the total torque τ of the dual-stator motor within 10 seconds m , motor speed ω and the identified parameters in the efficiency model of the outer stator motor and the inner stator motor are substituted into the overall efficiency model of the dual-stator motor in S401 to obtain the optimized torque distribution coefficient k corresponding to each sampling moment d .

[0133] Figure 6 This is a comparison diagram of the torque distribution coefficient of the dual-stator motor before and after optimization in this embodiment. It can be seen from the figure that the torque distribution coefficient before optimization is a constant, and the torque distribution coefficient after optimization is dynamically adjusted according to the real-time efficiency of the motor.

[0134] Figure 7 This is a comparison diagram of the real-time operating efficiency of the dual-stator motor before and after optimization in this embodiment. It can be seen from the figure that after optimizing the overall efficiency model of the dual-stator motor based on the sequential quadratic programming algorithm, the average efficiency of the dual-stator motor is improved by 54.02%, verifying the applicability of the real-time distribution method of the internal and external stator torque of the dual-stator motor proposed in the present invention.

[0135] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the embodiments of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the embodiments of the present invention shall be within the scope of the rights of the embodiments of the present invention.

Claims

1. A method for real-time distribution of internal and external stator torques of a dual-stator motor, comprising: Step 1: Establish an efficiency model of the external stator motor according to the torque, speed, copper loss and iron loss of the external stator motor; Step 2: Establish an efficiency model of the inner stator motor according to the torque, speed, copper loss and iron loss of the inner stator motor; Step 3: Based on the outer stator motor efficiency model and the inner stator motor efficiency model, establish a dual-stator motor overall efficiency model including a torque distribution coefficient; Step 4: Under the current constraints of the outer stator motor and the inner stator motor, based on the sequential quadratic programming algorithm, the overall efficiency model of the dual-stator motor is maximized to obtain the optimal torque distribution coefficient for real-time distribution of the torque of the inner and outer stators.

2. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 1, characterized in that: In step 1, the process of establishing the external stator motor efficiency model is as follows: The output power of the external stator motor is P out1 =τ m1 ω, where τ m1 is the torque of the external stator motor, ω is the motor speed; The input power of the external stator motor is P in1 =P out1 +P Loss1 , where the total power loss of the external stator motor is P Loss1 =P Cu1 +P Fe1 ; The external stator motor efficiency model η1 is expressed as:

3. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 2, characterized in that: The copper loss of the external stator motor is Among them, κ is the number of phases of the dual-stator motor, I1 is the external stator motor current, and R1 is the external stator motor resistance; The iron loss of the external stator motor is Among them, m1 is the mass of the outer stator motor core, K h1 is the hysteresis loss coefficient of the external stator motor, K c1 is the eddy current loss coefficient of the external stator motor, K e1 is the additional loss coefficient of the external stator motor, α1 is the coefficient of the associated hysteresis loss of the external stator motor, B1 is the amplitude of the sinusoidal magnetic flux density of the external stator motor, f = p m ω / (2π) is the frequency of the sinusoidal magnetic flux density, p m is the number of pole pairs of the double-stator motor; The external stator motor efficiency model η1 is expressed as: Among them, k t1 is the torque constant of the external stator motor.

4. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 1, characterized in that: In step 2, the process of establishing the internal stator motor efficiency model is as follows: The output power of the inner stator motor is P out2 =τ m2 ω, where τ m2 is the internal stator motor torque, ω is the motor speed; The input power of the inner stator motor is P in2 =P out2 +P Loss2 , where the total power loss of the internal stator motor is P Loss2 =P Cu2 +P Fe2 ; The inner stator motor efficiency model η2 is expressed as:

5. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 4, characterized in that: Internal stator motor copper loss P Cu2 for Among them, I2 is the internal stator motor current, R2 is the internal stator motor resistance; The iron loss of the inner stator motor is Among them, m2 is the mass of the inner stator motor core, K h2 is the internal stator motor hysteresis loss coefficient, K c2 is the eddy current loss coefficient of the internal stator motor, K e2 is the additional loss coefficient of the inner stator motor, α2 is the coefficient of the associated hysteresis loss of the inner stator motor, and B2 is the amplitude of the sinusoidal magnetic flux density of the inner stator motor; The inner stator motor efficiency model η2 is expressed as: Among them, k t2 is the internal stator motor torque constant.

6. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 1, characterized in that: In step 3, the overall efficiency model η of the dual-stator motor is expressed as:

7. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 6, characterized in that: The overall efficiency model η of the dual-stator motor is expressed as: Among them, k d represents the torque distribution coefficient of the dual-stator motor, τ m Represents the total torque of the dual-stator motor, 8. The method for real-time distribution of internal and external stator torques of a dual-stator motor according to claim 1, characterized in that: In step 4, the method for optimizing the torque distribution coefficient of the dual-stator motor is to maximize the overall efficiency model η of the dual-stator motor based on a sequential quadratic programming algorithm under the current constraints of the outer stator motor and the inner stator motor: st 0≤k d t m / k t1 ≤10 0≤(1-k d )t m / k t2 ≤8 0≤k d ≤1 Among them, Φ i =[K hi ,K ci ,K ei ,B i ,α i ,R i ], i = 1, 2; i = 1 represents the parameters of the outer stator motor, and i = 2 represents the parameters of the inner stator motor.

9. The method for real-time distribution of inner and outer stator torques of a dual-stator motor according to claim 8, characterized in that: Through the nonlinear least squares function, the unknown parameters Φ in the outer stator motor and the inner stator motor are identified i .

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