Load DC winding induced voltage optimization method, system, terminal and storage medium

Abstract

The present invention discloses a load DC winding induced voltage optimization method, system, terminal and storage medium. By determining the target motor to be optimized; taking the preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling coefficient as constraints; under the constraints, taking the average load electromagnetic torque as the optimization target, the parameters of the target motor are globally optimized; after the global optimization, taking the load DC winding induced voltage as the optimization target, the rotor skew angle and / or outer pole arc of the target motor are optimized again. After the global optimization of the motor parameters, the present invention optimizes the rotor skew angle and / or outer pole arc again, and changes the rotor topology to suppress the corresponding order harmonics, thereby weakening the DC winding voltage pulsation of the motor. The problem of the lack of a method for weakening the DC winding induced voltage pulsation for hybrid excitation magnetic field modulation motors in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor optimization, and in particular to a method, system, terminal and storage medium for optimizing a load DC winding induced voltage. Background Art

[0002] With the development of structural design and manufacturing technology, various new types of motors have emerged in an endless stream and are widely used in various fields of industrial production. As a device for converting electrical energy into mechanical energy, the air gap magnetic field of the motor is the key to achieving electromechanical conversion. According to the different ways of generating magnetic fields, motors are mainly divided into two categories: the first type requires windings to pass current to generate magnetic fields; the second type uses permanent magnets to directly generate magnetic fields. Electric excitation motors have low cost, good high temperature performance and adjustable magnetic fields, but high system complexity, low torque density and energy efficiency. In contrast, permanent magnet motors have simple structures, high torque density and efficiency, but low magnetic field adjustment flexibility, high temperature sensitivity and demagnetization problems. Hybrid excitation permanent magnet motors have both permanent magnet and coil structures, which have high torque density and high efficiency, as well as excellent flux controllability. Due to the flexible combination of two excitation sources (permanent magnet and field excitation coil excitation), the topological structures of hybrid excitation permanent magnet motors are diverse. The concept of hybrid excitation (HE) was first applied to traditional rotor permanent magnet motors, where the permanent magnet motor and excitation coil are both on the rotor side, and slip rings and brushes are required to conduct the excitation winding current, which reduces the reliability of the system. In order to achieve brushless operation, some professionals have proposed hybrid excitation permanent magnet motors with permanent magnets installed on the rotor side and excitation coils installed on the stator side. However, most of the current hybrid excitation permanent magnet motors have three-dimensional flux paths, which leads to complex motor structures and flux leakage problems, which in turn leads to reduced torque density.

[0003] In recent years, a hybrid excitation magnetic field modulation motor (HESFPM) with both permanent magnets and excitation coils on the stator side has been proposed. The hybrid excitation magnetic field modulation motor has the advantages of simple structure, brushless operation, controllable flux, high torque density, etc., and has good application prospects. However, this type of motor has the problem of DC winding induced voltage pulsation. The existence of DC winding induced voltage pulsation will cause ripples in the DC winding current, which will cause excitation fluctuations and increase the difficulty of motor control. At present, there are corresponding methods to weaken the DC winding induced voltage pulsation for wound-excitation synchronous motors. However, for hybrid excitation magnetic field modulation motors, there is a lack of corresponding methods to weaken the DC winding induced voltage pulsation.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the invention

[0005] The technical problem to be solved by the present invention is that, in view of the above-mentioned defects of the prior art, a method, system, terminal and storage medium for optimizing the induced voltage of a load DC winding are provided, aiming to solve the problem in the prior art of lacking a method for weakening the induced voltage pulsation of the DC winding of a hybrid excitation magnetic field modulation motor.

[0006] The technical solution adopted by the present invention to solve the problem is as follows:

[0007] In a first aspect, an embodiment of the present invention provides a method for optimizing a load DC winding induced voltage, the method comprising:

[0008] Determine the target motor to be optimized;

[0009] The preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor are used as constraints;

[0010] Under the constraint conditions, taking the average load electromagnetic torque as the optimization target, globally optimizing the parameters of the target motor;

[0011] After the global optimization, the skew angle and / or the outer pole arc of the rotor of the target motor are optimized again with the load DC winding induced voltage as the optimization target.

[0012] In one embodiment, the target motor is composed of a stator with a preset number of slots, a three-phase non-overlapping concentrated AC armature winding, a non-overlapping concentrated DC excitation winding, a preset number of circumferentially magnetized permanent magnets, and a plurality of salient pole rotors.

[0013] In one implementation, taking the average load electromagnetic torque as the optimization target and performing global optimization on the parameters of the target motor includes:

[0014] Taking the maximization of the average load electromagnetic torque as the optimization goal, the parameters of the target motor are globally optimized through a preset genetic algorithm.

[0015] In one embodiment, after the global optimization, the skew angle and / or outer pole arc of the rotor of the target motor is optimized again with the load DC winding induced voltage as the optimization target, including:

[0016] Predicting the load DC winding induced voltage of the target motor after global optimization through a simulation algorithm, and generating a performance score of the target motor according to the prediction result;

[0017] If the performance score is greater than the score threshold, the skew angle or the outer pole arc of the rotor of the target motor is optimized with minimization of the load DC winding induced voltage as the optimization goal;

[0018] If the performance score is less than or equal to the score threshold, the skew angle and the outer pole arc of the rotor of the target motor are optimized with minimization of the load DC winding induced voltage as the optimization goal.

[0019] In one embodiment, the method for optimizing the slant pole angle includes:

[0020] The number of skewed pole segments of the rotor in the target motor is determined, and the optimal skewed pole angle is determined by a preset finite element analysis algorithm with the minimization of the load DC winding induced voltage as the optimization goal.

[0021] In one embodiment, a method for optimizing an outer polar arc includes:

[0022] Obtaining all available arc combinations corresponding to two adjacent outer polar arcs, wherein the two arcs in each available arc combination are not equal;

[0023] Generate three-dimensional peak diagrams corresponding to the peak-to-peak value of the induced voltage of the load DC winding and the electromagnetic torque respectively according to all the available radian combinations;

[0024] Taking minimization of the induced voltage of the load DC winding as the optimization goal, the optimal arc combination is determined according to the two three-dimensional peak diagrams.

[0025] In one embodiment, the method for optimizing the slant polar angle and the outer polar arc includes:

[0026] The number of skewed pole segments, the skewed pole angle and the radian combination corresponding to two adjacent outer pole arcs of the rotor of the target motor are taken as the parameter set to be optimized, and the load DC winding induced voltage and electromagnetic torque are taken as optimization targets, and the optimal parameter set is determined by a preset global optimization algorithm.

[0027] In a second aspect, an embodiment of the present invention further provides a load DC winding induced voltage optimization system, the system comprising:

[0028] A determination module, used for determining a target motor to be optimized;

[0029] A constraint module, used to use preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor as constraint conditions;

[0030] A global optimization module, used for globally optimizing the parameters of the target motor under the constraint conditions and taking the average load electromagnetic torque as the optimization target;

[0031] The re-optimization module is used to re-optimize the skew angle and / or outer pole arc of the rotor of the target motor after the global optimization, taking the load DC winding induced voltage as the optimization target.

[0032] In a third aspect, an embodiment of the present invention further provides a terminal, comprising a memory and one or more processors; the memory stores one or more programs; the program comprises instructions for executing a load DC winding induced voltage optimization method as described in any one of the above; and the processor is used to execute the program.

[0033] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium on which a plurality of instructions are stored, wherein the instructions are suitable for being loaded and executed by a processor to implement the steps of any of the above-mentioned methods for optimizing the induced voltage of a load DC winding.

[0034] Beneficial effects of the present invention: After globally optimizing the motor parameters, the embodiments of the present invention further optimize the rotor's skew angle and / or outer pole arc, and suppress the corresponding order harmonics by changing the rotor topology, thereby weakening the motor's DC winding voltage pulsation. This solves the problem of the lack of a method for weakening the DC winding induced voltage pulsation of a hybrid excitation magnetic field modulation motor in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a flow chart of a method for optimizing the induced voltage of a load DC winding provided in an embodiment of the present invention.

[0037] Figure 2 It is a topological structure diagram of the hybrid excitation magnetic field modulation motor provided in an embodiment of the present invention.

[0038] Figure 3 It is a diagram of a rotor segmented skew pole structure provided in an embodiment of the present invention.

[0039] Figure 4 It is a schematic diagram of the influence of the tilt angle on the 6th and 12th harmonics provided by an embodiment of the present invention.

[0040] Figure 5 It is a schematic diagram of rotor teeth of unequal width provided by an embodiment of the present invention.

[0041] Figure 6 It is a schematic diagram showing that the peak-to-peak value of the induced voltage of the load DC winding is affected by the rotor outer pole arc provided by an embodiment of the present invention.

[0042] Figure 7It is a schematic diagram showing that the 6th and 12th harmonic amplitudes are affected by the rotor outer pole arc provided by an embodiment of the present invention.

[0043] Figure 8 It is a schematic diagram showing that the initial phases of the 6th and 12th harmonics are affected by the outer pole arc of the rotor provided by an embodiment of the present invention.

[0044] Fig. 9 It is a schematic diagram of the influence of different tilt angles on the induced voltage provided by an embodiment of the present invention.

[0045] Fig.10 It is a schematic diagram of the influence of rotor segment inclination on the induced voltage of the DC winding provided by an embodiment of the present invention.

[0046] Fig.11 It is a schematic diagram of the influence of the segmented inclination of the rotor on the peak-to-peak value of the induced voltage of the DC winding provided by an embodiment of the present invention.

[0047] Fig.12 It is a schematic diagram of the influence of the 5-segment skewed pole of the rotor provided by an embodiment of the present invention on the induced voltage of the load DC winding.

[0048] Fig.13 It is a schematic diagram of the influence of rotor segmented skew poles on load torque provided by an embodiment of the present invention.

[0049] Fig.14 It is a schematic diagram of the influence of unequal width rotor teeth on the peak-to-peak value of the induced voltage of the load DC winding provided by an embodiment of the present invention.

[0050] Fig.15 It is a schematic diagram of the influence of unequal width rotor teeth on the average load electromagnetic torque provided by an embodiment of the present invention.

[0051] Fig.16 This is the optimal combination diagram of unequal width rotor teeth that minimizes the induced voltage drop of the load DC winding provided by the embodiment of the present invention.

[0052] Fig.17 It is a schematic diagram of the influence of unequal width rotor teeth on the induced voltage of the load DC winding provided by an embodiment of the present invention.

[0053] Fig.18 It is a schematic diagram of the influence of unequal width rotor teeth on load torque provided by an embodiment of the present invention.

[0054] Fig.19 It is a module schematic diagram of a load DC winding induction voltage optimization system provided in an embodiment of the present invention.

[0055] Fig. 20 It is a principle block diagram of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The present invention discloses a method, system, terminal and storage medium for optimizing the induced voltage of a load DC winding. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to 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.

[0057] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0058] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0059] In view of the above-mentioned defects of the prior art, the present invention provides a method for optimizing the induced voltage of a load DC winding, the method determining the target motor to be optimized; taking the preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling coefficient as constraints; under the constraints, taking the average load electromagnetic torque as the optimization target, the parameters of the target motor are globally optimized; after the global optimization, taking the induced voltage of the load DC winding as the optimization target, the skew angle and / or outer pole arc of the rotor of the target motor are optimized again. After the global optimization of the motor parameters, the present invention further optimizes the skew angle and / or outer pole arc of the rotor, and changes the rotor topology to suppress the corresponding order harmonics, thereby weakening the DC winding voltage pulsation of the motor. The problem that there is a lack of a method for weakening the induced voltage pulsation of the DC winding of a hybrid excitation magnetic field modulation motor in the prior art is solved.

[0060] like Figure 1 As shown, the method includes:

[0061] Step S100: Determine a target motor to be optimized.

[0062] Specifically, the target motor of this embodiment is a hybrid excitation magnetic field modulation motor to be optimized, and the optimization task is to weaken the DC winding induced voltage pulsation of the target motor.

[0063] In one implementation, the target motor is composed of a stator with a preset number of slots, a three-phase non-overlapping concentrated AC armature winding, a non-overlapping concentrated DC excitation winding, a preset number of circumferentially magnetized permanent magnets, and a plurality of salient pole rotors.

[0064] Specifically, taking a 12-slot 10-pole hybrid excitation field modulation motor as an example, the target motor consists of a 12-slot stator, a three-phase non-overlapping concentrated AC armature winding, a non-overlapping concentrated DC excitation winding, 12 circumferentially magnetized permanent magnets, and a 10-pole salient rotor. In addition, the controllability of the magnetic flux can be enhanced by an iron flux bridge adjacent to the DC field winding slot. The overall topology of the motor is as follows: Figure 2 shown.

[0065] Step S200: using the preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factors as constraint conditions.

[0066] Specifically, armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor are all important performance parameters of the motor. Appropriate armature winding copper loss can improve the efficiency of the target motor; appropriate DC winding slot current density can avoid overheating and damage of the insulating material in the slot; appropriate slot filling factor can increase the copper cross-section of the winding, reduce copper loss, and avoid insulation difficulties in the slot. Therefore, this embodiment uses these parameters to set the constraints for subsequent global optimization, thereby effectively improving the performance of the target motor.

[0067] Step S300: Under the constraint conditions, taking the average load electromagnetic torque as the optimization target, globally optimizing the parameters of the target motor.

[0068] Specifically, the average load electromagnetic torque is an important indicator of motor performance. In this embodiment, under a given copper loss level and fill factor, while ensuring that the current density is within a safe range, the average load electromagnetic torque is used as the optimization target to perform global optimization on the parameters of the target motor. Global optimization can find the global optimal solution or approximate optimal solution within a larger search range, thereby effectively improving the performance of the target motor.

[0069] In one implementation, taking the average load electromagnetic torque as the optimization target and performing global optimization on the parameters of the target motor includes:

[0070] Taking the maximization of the average load electromagnetic torque as the optimization goal, the parameters of the target motor are globally optimized through a preset genetic algorithm.

[0071] Specifically, this embodiment selects to use a genetic algorithm to perform global optimization on the target motor. The global optimization goal is to maximize the average load electromagnetic torque of the target motor to improve the output power and efficiency of the motor.

[0072] For example, the motor is globally optimized through genetic algorithm. When the armature winding copper loss is 20W and the DC winding slot current density is 5A / mm 2 Under the constraint that the slot filling factor of the armature winding and the DC excitation winding is 0.5, global optimization is performed with the maximum average load electromagnetic torque as the goal. The motor related parameters are shown in Table 1.

[0073] Table 1. Motor related parameters

[0074]

[0075] In one implementation, the parameters of the target motor are globally optimized by a preset genetic algorithm, including:

[0076] According to several parameter setting schemes of the target motor, construct an individual corresponding to each parameter setting scheme, wherein the chromosome of each individual is composed of a gene set, and each gene in the gene set represents a parameter of the target motor;

[0077] Using the fitness function to evaluate each individual, and obtaining the fitness score corresponding to each individual; wherein the fitness function may be an objective function established in advance with the maximum average load electromagnetic torque as the optimization target;

[0078] According to the fitness score of each individual, determine the reproductive selection weight corresponding to each individual;

[0079] According to the reproductive selection weight of each individual, the parent population for reproduction is selected;

[0080] Perform chromosome crossover recombination based on individuals in the parent population to obtain several new individuals;

[0081] Use the fitness function to evaluate each individual, obtain the fitness score corresponding to each individual, and determine whether the change in the highest fitness score in the last few rounds reaches the preset target;

[0082] If not reached, continue to execute the step of determining the breeding selection weight corresponding to each individual according to the fitness score of each individual, until the change in the highest fitness score in the most recent rounds reaches the preset target, and determine the optimal parameter setting plan for the target motor according to the individual corresponding to the highest fitness score.

[0083] Step S400: After the global optimization, the skew angle and / or the outer pole arc of the rotor of the target motor are optimized again with the load DC winding induced voltage as the optimization target.

[0084] Theoretically, if the DC winding current is constant, the DC winding flux is constant, and there will be no induced voltage pulsation. In fact, the DC winding flux is not constant and is affected by harmonics, so an induced voltage will be generated. The DC winding induced voltage consists of two components, namely the open circuit induced DC winding voltage and the armature current induced voltage. When the rotor rotates, the double salient pole structure of the hybrid excitation magnetic field modulation motor causes the equivalent air gap magnetic resistance to change, thereby causing the open circuit induced DC winding voltage, while the armature current induced voltage is caused by the mutual inductance between the armature current and the AC and DC windings. Taking a 12-slot 10-pole hybrid excitation magnetic field modulation motor as an example, the multiple harmonics (6k) of 6 cannot be offset, which has a great impact on the motor induced voltage pulsation and output torque pulsation. Therefore, it is also necessary to further optimize the motor parameters to weaken the 6k harmonics, thereby weakening the DC winding induced voltage pulsation. Specifically, this embodiment mainly uses two methods, namely, rotor segmented skew poles and unequal width rotor teeth, to weaken the DC winding induced voltage of the hybrid excitation magnetic field modulation motor. The segmented rotor skew method is to adjust the skew angle of the rotor skew pole, and the unequal width rotor tooth method is to adjust the arc of the two adjacent outer pole arcs of the rotor. In addition to weakening the DC winding induced voltage, these two methods can also simultaneously weaken the back EMF harmonics, cogging torque and torque pulsation, thereby improving the relevant performance of the motor.

[0085] In one implementation, after the global optimization, the skew angle and / or outer pole arc of the rotor of the target motor is optimized again with the load DC winding induced voltage as the optimization target, including:

[0086] Predicting the load DC winding induced voltage of the target motor after global optimization through a simulation algorithm, and generating a performance score of the target motor according to the prediction result;

[0087] If the performance score is greater than the score threshold, the skew angle or the outer pole arc of the rotor of the target motor is optimized with minimization of the load DC winding induced voltage as the optimization goal;

[0088] If the performance score is less than or equal to the score threshold, the skew angle and the outer pole arc of the rotor of the target motor are optimized with minimization of the load DC winding induced voltage as the optimization goal.

[0089] Specifically, for rotor segmented skew poles, Figure 3 The figure is a schematic diagram of a segmented rotor skewed pole. Compared with a continuous skewed pole, a segmented rotor skewed pole is easier to manufacture and has similar performance. Figure 4As shown, the amplitudes of the 6th and 12th harmonics are affected by the tilt angle (θ sk Therefore, this embodiment can reduce the harmonic amplitude through the rotor segmented skewing method, thereby suppressing the DC winding induced voltage. Figure 5 is a schematic diagram of unequal width rotor teeth. For unequal width rotor teeth, the peak-to-peak value of the induced voltage of the load DC winding changes with the change of the rotor outer pole arc (e.g. Figure 6 As shown above). As mentioned above, there are 6th harmonics and their multiples in the load DC winding induced voltage, of which the 6th and 12th are the main harmonics, as shown in Figure 7 and Figure 8 As shown, the amplitude and initial phase of the 6th and 12th harmonics are affected by the rotor outer pole arc. Therefore, this embodiment can also reduce the harmonic amplitude by having a rotor with unequal width teeth, that is, a pair of rotor outer pole arcs with unequal arcs, thereby suppressing the load DC winding induced voltage. In practical applications, the performance of the motor after global optimization can be first evaluated by a simulation algorithm. If the motor performance is better, a pair of motor parameters are selected from the two methods of rotor segmented skew poles and unequal width rotor teeth for further optimization; if the motor performance is not good, the motor parameters are further optimized by using the two methods of rotor segmented skew poles and unequal width rotor teeth.

[0090] In one implementation, the method for optimizing the slant pole angle includes:

[0091] The number of skewed pole segments of the rotor in the target motor is determined, and the optimal skewed pole angle is determined by a preset finite element analysis algorithm with the minimization of the load DC winding induced voltage as the optimization goal.

[0092] Specifically, the optimization of the skew angle is the rotor segmented skew method, which is to divide the rotor's magnetic poles into several segments and arrange the magnetic poles at an oblique angle. The rotor's skew angle is the angle or skew angle between the center line of the motor rotor and the center line of the permanent magnet magnetic pole. The increase in the number of rotor skew segments will lead to an increase in the complexity, instability and manufacturing cost of the motor structure, so it is necessary to select a suitable number of skew segments based on actual conditions. Then, the minimization of the load DC winding induced voltage is taken as the optimization goal, and the finite element analysis algorithm is used to search and analyze the optimal rotor skew angle under the limited number of rotor skew segments.

[0093] In one implementation, determining the optimal oblique polar angle by using a preset finite element analysis algorithm includes:

[0094] Establish a motor system operation model based on the globally optimized target motor;

[0095] The motor system operation model is divided into several functional units related to the load DC winding induced voltage,

[0096] The rotor skew angle is used as a simulation input parameter, and the load DC winding induced voltage is set as a simulation output parameter to optimize the rotor skew angle;

[0097] The optimal tilting angle is determined based on the response curve of the load DC winding induced voltage of the target motor obtained by simulation.

[0098] In one implementation, a method for selecting the number of skewed pole segments of a rotor includes:

[0099] Obtain the curve image of the load DC winding induced voltage changing with the number of oblique pole segments;

[0100] According to the change curve image, determine the number of skew pole segments of the rotor.

[0101] Specifically, the more the number of skewed pole segments, the better the suppression effect of the induced voltage of the load DC winding, but the selection of the number of skewed pole segments of the rotor cannot be infinite, and the optimization effect will become weak after the number of skewed pole segments increases to a certain number. Therefore, this embodiment can predict the change curve image of the induced voltage of the load DC winding with the number of skewed pole segments through simulation technology, and select the appropriate number of skewed pole segments by analyzing the change in the slope of the change curve image. If the difference between the drop rate of the induced voltage of the load DC winding of the current skewed pole segment number and the previous skewed pole segment number is less than the preset threshold, indicating that the optimization effect has become weak, the previous skewed pole segment number is used as the final selected skewed pole segment number. For example, when the rotor is divided into 5 sections, the induced voltage of the load DC winding has dropped by 96.15%. On this basis, the optimization effect achieved by further segmentation is relatively weak, so the rotor 5-segment skewed pole is selected as the best number of skewed pole segments.

[0102] The technical effect after the optimization of the slant pole angle is proved: in order to minimize the induced voltage of the DC winding, in the case of 5 slant poles (N=5), the slant pole angle is used as the optimization parameter and the load DC winding induced voltage is used as the optimization target for optimization. That is, different slant pole angles are calculated by finite element analysis. The results are as follows Fig. 9 The results show that when θ sk =110°, the load DC winding induced voltage is minimum. Therefore, in the following analysis, θ sk =110° as the rotor skew angle. Fig.10 and Fig.11 As shown, the segmented rotor skew effectively reduces the load DC winding induced voltage. For segmented skews from 1 to 5, the peak-to-peak values ​​of the load DC winding induced voltage are 0.51V, 0.28V, 0.14V, 0.05V and 0.02V respectively. When N=1, the rotor is non-skewed (i.e., no skew); therefore, for motors with 2, 3, 4 and 5 skewed sections, the reduction rates of the load DC winding induced voltage are 44.01%, 71.63%, 89.28% and 96.15% respectively. Fig.12 As shown, due to the suppression of the 6th and 12th voltage harmonics, when 5-section skew is used, the load DC winding induced voltage reduction rate is the largest, that is, 96.15%. It should be noted that although the rotor segmented skew method (i.e., optimization of the skew angle) will cause a slight decrease in the output torque, from 1 section to 5 sections of skew, the average output torque is 1.29Nm, 1.14Nm, 1.16Nm, 1.16Nm and 1.15Nm, that is, the reduction rate is 11.3%, 9.9%, 10.2% and 10.6%, respectively, but at the same time, the torque pulsation is also suppressed by the rotor segmented skew. From 1 section to 5 sections of skew, the torque pulsation is 12.27%, 10.51%, 3.07%, 1.49% and 1.25%, respectively. Therefore, the torque pulsation reduction rate is much higher than the output average torque reduction rate, and the rotor segmented skew has a positive effect on the output torque. The results are shown in Fig.13 shown.

[0103] In one implementation, a method for optimizing an outer polar arc includes:

[0104] Obtaining all available arc combinations corresponding to two adjacent outer polar arcs, wherein the two arcs in each available arc combination are not equal;

[0105] Generate three-dimensional peak diagrams corresponding to the peak-to-peak value of the induced voltage of the load DC winding and the electromagnetic torque respectively according to all the available radian combinations;

[0106] Taking minimization of the induced voltage of the load DC winding as the optimization goal, the optimal arc combination is determined according to the two three-dimensional peak diagrams.

[0107] Specifically, the optimization of the outer pole arc is the unequal width rotor tooth method, which is to design the rotor in pairs with different widths to optimize the magnetic field distribution. First, the finite element analysis method can be used to calculate all possible radian combinations of two adjacent outer pole arcs when they are not equal, that is, to obtain multiple available radian combinations. Then, for each available radian combination, the peak-to-peak value and electromagnetic torque of the corresponding load DC winding induced voltage can be calculated by the motor algorithm model, and two three-dimensional peak diagrams are constructed based on the two calculation results of all available radian combinations. In the three-dimensional peak diagram corresponding to the peak-to-peak value of the load DC winding induced voltage, the X and Y axes represent an outer pole arc of the available radian combination, and the Z axis represents the peak-to-peak value of the load DC winding induced voltage; in the three-dimensional peak diagram corresponding to the electromagnetic torque, the X and Y axes represent an outer pole arc of the available radian combination, and the Z axis represents the electromagnetic torque. Then observe and analyze the two three-dimensional peak diagrams, especially the three-dimensional peak diagram corresponding to the peak-to-peak value of the induced voltage of the load DC winding, find the area where the peak-to-peak value of the induced voltage of the load DC winding is the smallest or smaller in the three-dimensional peak diagram, and find the available radian combination in this area that meets the electromagnetic torque requirements and has the relatively smallest peak-to-peak value of the induced voltage of the load DC winding, that is, the optimal radian combination.

[0108] In one implementation, a three-dimensional peak map is an implementation method for visualizing a three-dimensional data set. When constructing a three-dimensional peak map, different viewing angles and color mappings can be selected to display data features.

[0109] Technical effect after optimization of the outer pole arc: In this embodiment, a pair of rotor outer pole arcs is defined as rotor outer pole arcs 1 and 2. In order to minimize the load DC winding induced voltage, all available combinations of rotor outer pole arcs 1 and 2 are calculated by the finite element analysis method, and their influence on the load DC winding induced voltage and output torque is analyzed. The peak-to-peak value of the load DC winding induced voltage and the load torque are affected by the rotor outer pole arcs 1 and 2 as shown in the figure. Fig.14 and Fig.15 As shown. After analysis, we can get that θ r1 =19° and θ r2 =20° can minimize the load DC winding induced voltage. Fig.16 The finite element analysis results are shown in Fig.17 and Fig.18 As shown. It can be seen that when θ r1 =19° and θ r2 =20°, the load DC winding induced voltage reduction rate is 89.05%, and the output torque ripple is reduced from 12.27% to 8.17%.

[0110] In one implementation, the method for optimizing the slant pole angle and the outer pole arc includes:

[0111] The number of skewed pole segments, the skewed pole angle and the radian combination corresponding to two adjacent outer pole arcs of the rotor of the target motor are taken as the parameter set to be optimized, and the load DC winding induced voltage and electromagnetic torque are taken as optimization targets, and the optimal parameter set is determined by a preset global optimization algorithm.

[0112] Specifically, the optimization of the skew angle and the outer pole arc at the same time is a comprehensive optimization method. The comprehensive optimization method can more significantly weaken the induced voltage pulsation of the DC winding of the hybrid excitation magnetic field modulation motor. In practical applications, the combination of the skew angle, the number of rotor segments, and the arcs corresponding to two adjacent outer pole arcs (i.e. Figure 5 The rotor outer pole arc 1 and 2 in the figure are used as optimization parameters, and a global optimization is performed with the DC winding induced voltage and output torque as the optimization objectives to determine the best parameter combination.

[0113] In one implementation, the global optimization algorithm may adopt a particle swarm optimization algorithm, which specifically includes:

[0114] A particle swarm is constructed according to the parameters of the target motor after global optimization, wherein each particle in the particle swarm corresponds to a different parameter;

[0115] Initialize the position and velocity of the particle swarm;

[0116] Calculate the fitness (the value of the objective function) of each particle based on its position and velocity;

[0117] Calculate the total fitness based on the fitness of each particle and determine whether the total fitness reaches the preset optimization goal;

[0118] If not, the respective speed and position are updated according to the fitness of each particle, and the step of calculating the fitness of each particle according to the position and speed of each particle is continued until the total fitness reaches the preset optimization target.

[0119] In another implementation, the target motor after global optimization can be further optimized through the following optimization directions:

[0120] Deformation of winding structure: for example, a method for weakening the induced voltage pulsation of the DC winding of an integer-slot hybrid excitation magnetic field modulation motor; the application of segmented rotor skew poles in weakening the induced voltage pulsation of the DC winding of an integer-slot hybrid excitation magnetic field modulation motor; the application of unequal-width rotor teeth in weakening the induced voltage pulsation of the DC winding of an integer-slot hybrid excitation magnetic field modulation motor.

[0121] Variations of the weakening method: for example, the application of the comprehensive optimization method of "segmented rotor skew poles + unequal width rotor teeth" in weakening the induced voltage pulsation of the DC winding of the hybrid excitation magnetic field modulation motor.

[0122] Variation of design objectives: for example, a method for weakening the torque pulsation of a hybrid excitation magnetic field modulation motor; a method for weakening the back EMF harmonics of a hybrid excitation magnetic field modulation motor; a method for weakening the cogging torque of a hybrid excitation magnetic field modulation motor.

[0123] Variation of research direction: Using the air gap field modulation principle and frozen permeability method to quantitatively analyze and separate the DC winding induced voltage under different conditions in the hybrid excitation magnetic field modulation motor, the influence of the armature winding phase number (three-phase, five-phase, two-phase, etc.) on the DC winding induced voltage in the hybrid excitation magnetic field modulation motor, the influence of AC and DC winding configurations (such as single-layer, double-layer, and different coil spacing configurations) on the DC winding induced current of the hybrid excitation magnetic field modulation motor, etc.

[0124] The advantages of the present invention are:

[0125] The present invention provides two methods for weakening the induced voltage pulsation of the DC winding of a hybrid excitation magnetic field modulation motor. Taking a 12-slot 10-pole double-salient hybrid excitation magnetic field modulation motor as the research object, based on the generation mechanism of the induced voltage of the DC winding, the influence of the 6k harmonic on the induced voltage pulsation of the DC winding is determined, and starting from the idea of ​​changing the rotor topology to suppress the corresponding order harmonics, two rotor structure optimization methods are proposed. These two methods are applied to a 12-slot 10-pole double-salient hybrid excitation magnetic field modulation motor. The finite element analysis method and the multi-objective optimization method are used to change the corresponding parameters and compare the optimization results to select the optimal value, which can effectively reduce the DC winding voltage pulsation, cogging torque, back electromotive force harmonics and torque ripple.

[0126] The results show that the segmented skewed poles and unequal width rotor teeth can effectively suppress the induced voltage of the load DC winding, and its peak-to-peak value can be reduced by 96.15% and 89.05% respectively, while the average load electromagnetic torque can be maintained at 89.4% and 87.8%, which not only reduces the induced voltage of the load DC winding but also maintains a high output torque.

[0127] Based on the above embodiments, the present invention also provides a load DC winding induced voltage optimization system, such as Fig.19 As shown, the system comprises:

[0128] Determination module 01, used to determine the target motor to be optimized;

[0129] The constraint module 02 is used to use the preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor as constraint conditions;

[0130] A global optimization module 03 is used to perform global optimization on the parameters of the target motor under the constraint conditions and with the average load electromagnetic torque as the optimization target;

[0131] The re-optimization module 04 is used to re-optimize the skew angle and / or outer pole arc of the rotor of the target motor after the global optimization, taking the load DC winding induced voltage as the optimization target.

[0132] Based on the above embodiment, the present invention further provides a terminal, whose principle block diagram can be shown as follows: Fig. 20 As shown. The terminal includes a processor, a memory, a network interface, and a display screen connected through a system bus. Among them, the processor of the terminal is used to provide computing and control capabilities. The memory of the terminal includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the terminal is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for optimizing the induced voltage of a load DC winding is implemented. The display screen of the terminal can be a liquid crystal display screen or an electronic ink display screen.

[0133] Those skilled in the art will understand that Fig. 20 The principle block diagram shown in the figure is only a block diagram of a partial structure related to the scheme of the present invention, and does not constitute a limitation on the terminal to which the scheme of the present invention is applied. The specific terminal may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0134] In one implementation, the memory of the terminal stores one or more programs, and is configured to be executed by one or more processors. The one or more programs include instructions for performing a method for optimizing a load DC winding induced voltage.

[0135] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0136] In summary, the present invention discloses a method, system, terminal and storage medium for optimizing the induced voltage of a load DC winding. The method determines the target motor to be optimized; takes the preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling coefficient as constraints; under the constraints, takes the average load electromagnetic torque as the optimization target, and globally optimizes the parameters of the target motor; after global optimization, takes the load DC winding induced voltage as the optimization target, and optimizes the skew angle and / or outer pole arc of the rotor of the target motor again. After globally optimizing the motor parameters, the present invention optimizes the skew angle and / or outer pole arc of the rotor again, and suppresses the corresponding order harmonics by changing the rotor topology, thereby weakening the DC winding voltage pulsation of the motor. The problem of the lack of a method for weakening the induced voltage pulsation of the DC winding of a hybrid excitation magnetic field modulation motor in the prior art is solved.

[0137] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for optimizing the induced voltage of a load DC winding, characterized in that: The method comprises: Determine the target motor to be optimized; The preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor are used as constraints; Under the constraint conditions, taking the average load electromagnetic torque as the optimization target, globally optimizing the parameters of the target motor; After the global optimization, the skew angle and / or the outer pole arc of the rotor of the target motor are optimized again with the load DC winding induced voltage as the optimization target; After the global optimization, the skew angle and / or outer pole arc of the rotor of the target motor are optimized again with the load DC winding induced voltage as the optimization target, including: Predicting the load DC winding induced voltage of the target motor after global optimization through a simulation algorithm, and generating a performance score of the target motor according to the prediction result; If the performance score is greater than the score threshold, the skew angle or the outer pole arc of the rotor of the target motor is optimized with minimization of the load DC winding induced voltage as the optimization goal; If the performance score is less than or equal to the score threshold, the skew angle and the outer pole arc of the rotor of the target motor are optimized with minimization of the load DC winding induced voltage as the optimization goal.

2. The method for optimizing the load DC winding induced voltage according to claim 1, characterized in that: The target motor is composed of a stator with a preset number of slots, a three-phase non-overlapping concentrated AC armature winding, a non-overlapping concentrated DC excitation winding, a preset number of circumferentially magnetized permanent magnets, and a plurality of salient pole rotors.

3. The method for optimizing the load DC winding induced voltage according to claim 1, characterized in that: The globally optimizing the parameters of the target motor with the average load electromagnetic torque as the optimization target includes: Taking the maximization of the average load electromagnetic torque as the optimization goal, the parameters of the target motor are globally optimized through a preset genetic algorithm.

4. The method for optimizing the load DC winding induced voltage according to claim 1, characterized in that: Methods for optimizing the slant pole angle include: The number of skewed pole segments of the rotor in the target motor is determined, and the optimal skewed pole angle is determined by a preset finite element analysis algorithm with the minimization of the load DC winding induced voltage as the optimization goal.

5. The method for optimizing the load DC winding induced voltage according to claim 1, characterized in that: Methods for optimizing the outer polar arc include: Obtaining all available arc combinations corresponding to two adjacent outer polar arcs, wherein the two arcs in each available arc combination are not equal; Generate three-dimensional peak diagrams corresponding to the peak-to-peak value of the induced voltage of the load DC winding and the electromagnetic torque respectively according to all the available radian combinations; Taking minimization of the induced voltage of the load DC winding as the optimization goal, the optimal arc combination is determined according to the two three-dimensional peak graphs.

6. The method for optimizing the load DC winding induced voltage according to claim 1, characterized in that: Methods for optimizing the slant pole angle and the outer pole arc include: The number of skewed pole segments, the skewed pole angle and the radian combination corresponding to two adjacent outer pole arcs of the rotor of the target motor are taken as the parameter set to be optimized, and the load DC winding induced voltage and electromagnetic torque are taken as optimization targets, and the optimal parameter set is determined by a preset global optimization algorithm.

7. A load DC winding induction voltage optimization system, characterized in that: The system comprises: A determination module, used for determining a target motor to be optimized; A constraint module, used to use preset armature winding copper loss, DC winding slot current density, armature winding and DC excitation winding slot filling factor as constraint conditions; A global optimization module, used for globally optimizing the parameters of the target motor under the constraint conditions and taking the average load electromagnetic torque as the optimization target; A re-optimization module is used to re-optimize the skew angle and / or outer pole arc of the rotor of the target motor after the global optimization, taking the load DC winding induced voltage as the optimization target; After the global optimization, the skew angle and / or outer pole arc of the rotor of the target motor are optimized again with the load DC winding induced voltage as the optimization target, including: Predicting the load DC winding induced voltage of the target motor after global optimization through a simulation algorithm, and generating a performance score of the target motor according to the prediction result; If the performance score is greater than the score threshold, the skew angle or the outer pole arc of the rotor of the target motor is optimized with minimization of the load DC winding induced voltage as the optimization goal; If the performance score is less than or equal to the score threshold, the skew angle and the outer pole arc of the rotor of the target motor are optimized with minimization of the load DC winding induced voltage as the optimization goal.

8. A terminal, characterized in that: The terminal includes a memory and one or more processors; the memory stores one or more programs; the program contains instructions for executing the load DC winding induced voltage optimization method as described in any one of claims 1-6; and the processor is used to execute the program.

9. A computer-readable storage medium having a plurality of instructions stored thereon, characterized in that: The instructions are suitable for being loaded and executed by a processor to implement the steps of the load DC winding induced voltage optimization method described in any one of claims 1 to 6 above.

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