68 results about "Armature current" patented technology

The invention relates to the technical field of permanent magnet motors, in particular to a salient pole rate reversible degree enhanced permanent magnet motor and a design method thereof. The salient pole rate reversible degree enhanced permanent magnet motor comprises a rotating shaft, a rotor sleeving the rotating shaft, and a stator coaxially sleeving the rotor; eight trapezoidal magnetic barriers with centers on a q axis and eight bread-type permanent magnets with centers on a d axis are embedded in the rotor along the circumferential direction in a staggered manner; the bread-type permanent magnets are magnetized along the inner and outer thickness directions, and the magnetizing directions are opposite; and two sides of each bread-shaped permanent magnet are respectively provided with a bulb-shaped magnetic barrier contacted with the bread-shaped permanent magnet. According to the invention, a plurality of variable magnetic resistances instead of a single magnetic resistance can be innovatively introduced into the rotor by ingeniously changing the armature current under different working conditions, so that the leakage magnetic flux and the effective magnetic flux of the motor are changed, meanwhile, the target of enhancing the reversible degree of the salient pole rate under all working conditions is achieved, and the diversified performance requirements under different working conditions can be met.

The invention belongs to the related technical field of motor control, and discloses a permanent magnet synchronous motor field weakening control method and device fusing current feedforward and model prediction control, and the method comprises the steps: (1) building a multi-objective optimization function based on a torque tracking error, current fluctuation and voltage limitation of a permanent magnet synchronous motor, solving the multi-objective optimization function through an interior point penalty function and a Newton iteration method based on a feedforward instruction torque and a model prediction control instruction torque to obtain an optimal current pair of the permanent magnet synchronous motor; (2) constructing a field weakening control fusion model based on the obtained optimal current pair, the feed-forward instruction torque and the model prediction control instruction torque; and (3) fusing the feedforward instruction torque and the model prediction control instruction torque through the dynamic weight factor of the flux-weakening control fusion model, and obtaining a flux-weakening control instruction of the permanent magnet synchronous motor in combination with the optimal current pair, thereby realizing flux-weakening control of the synchronous permanent magnet motor. The method has a multi-target cooperation capability.

The invention discloses a deep-sea robot driving motor current-sharing heat balance method, which comprises the following steps of S1, constructing a differential equation set for describing input and output characteristics of a motor, and covering mechanical and electrical parts; s2, measuring the current and the rotating speed of each armature in real time, and calculating a current difference value; s3, constructing a parameter matrix and a solution matrix for calculating a control gain, and establishing a weight matrix and an adjustment coefficient for dynamically calculating a control signal; s4, updating the control weight matrix in real time according to the current difference value, iteratively updating the solution matrix, calculating a control voltage signal and applying the control voltage signal to each armature; the current-sharing heat balance method is based on the current signals of the armatures of the motor, the deviation signals are calculated, the control voltage is dynamically adjusted, it is ensured that the rotating speed of the motor accurately tracks the target signals, it is also ensured that currents of the armatures tend to be the same, heat balance between the armatures is achieved, and stable operation of the motor is ensured.

The invention discloses a rotating speed loop control method for stable magnetic adjustment of a magnetic flux adjustable permanent magnet synchronous motor, belongs to the field of motor control, and aims to solve the problem that reluctance torque changes drastically during online magnetic adjustment of the magnetic flux adjustable permanent magnet synchronous motor. The method comprises the following steps of: 1, training a neural network model by taking an inductance parameter and a permanent magnet flux linkage which change along with a magnetization state and a direct-axis current as a data set; step 2, obtaining motor quadrature-direct axis current according to the collected stator current and rotor position information, and obtaining prediction values of motor inductance parameters and permanent magnet flux linkage through the trained model; 3, inputting the motor quadrature-direct axis current, the inductance parameter prediction value and the permanent magnet flux linkage prediction value into a torque-current gain adjuster to obtain a reluctance torque corresponding component prediction value and an adjusted torque-current gain; 4, obtaining a given value of quadrature-axis current, and further obtaining a driving signal of the inverter; and repeating the steps 2-4, and suppressing the torque rotating speed pulsation during the magnetic adjusting period.

The embodiment of the invention discloses a multiplex type three-stage starting power generation controller, and relates to the technical field of aviation three-stage starting power generators. In the starting stage, an H-bridge inverter in the starting power generation controller provides single-phase alternating-current exciting current for a main exciter stator exciting winding through SPWM modulation so as to establish a pulsating magnetic field to provide exciting current for a main motor, and a three-phase full-bridge inverter provides armature current for a main motor stator armature winding through SVPWM modulation. In a power generation stage, an anti-parallel diode of the three-phase full-bridge inverter is used as a rectification circuit of the auxiliary exciter, and the H-bridge inverter adopts a PWM chopping mode to operate as an asymmetric half-bridge circuit. A power generation controller and a starting controller are integrated into a whole, and by changing the modulation mode of a hardware circuit, the control function of the three-stage starting generator at different stages can be realized by only one controller, so that the structure of the starting power generation controller is simplified, the system integration degree of the three-stage starting generator is improved, and the volume and the weight of the system are reduced.

An electromagnetic transient modeling method and system for a high-efficiency synchronous machine, and, a device. The method comprises: predicting, of a synchronous machine, a first rotor angular velocity, a first rotor angle, and a first current q component of and a first current d component of an armature current, establishing a first Norton circuit for simulating the synchronous machine, and solving at the same time a second Norton circuit after equivalent transformation and a network conductance matrix so as to obtain a three-phase voltage of a synchronous machine port; according to the three-phase voltage, obtaining a second current q component, a second current d component, a second rotor angular velocity and a second rotor angle; and by means of error-controlled iterative solving, determining an electromagnetic transient simulation calculation result of the synchronous machine.

The invention relates to a method for calculating an induction flux vector angle, comprising a plurality of iterations, each iteration of the plurality of iterations except for the first one comprising: a / obtaining (S100) input data comprising armature voltage values, armature current values, armature resistance values and inductance values associated with the armature; b / estimating (S101) the induction flux vector of the iteration by adding a function of said input data to an induction flux vector obtained in the previous iteration, c / a correction comprising i. determining (S102) the centre of a circle passing through at least three points defined by the flux vector obtained through said estimation, and at least two flux vectors obtained in two previous iterations, and, ii. obtaining the flux vector of the current iteration, in which the flux vector obtained through said estimation is corrected (S106, S107) using said centre vector.

The smart torque simulation device includes: a bracket; a shaft center; a winding wheel which having a winding wheel spinning encoder; an outer flywheel which an outer flywheel spinning encoder, the winding wheel and the outer flywheel are relatively coupled with a magnetic plate and a magnet; an inner flywheel with a field magnet, the inner flywheel has a power transmission relationship with the outer flywheel; a coil set, having a coil fixing frame which has an armature coil, and the armature coil is coupled to the field magnet of the inner flywheel, the armature coil has an electric current regulator; and a control system, receiving a winding wheel spinning data from the winding wheel spinning encoder and receiving an outer flywheel spinning data from the outer flywheel spinning encoder, and then sending an armature electric current control data to the electric current regulator.

The utility model discloses a current detection amplifying circuit in the technical field of direct current motor detection, which comprises a detection resistor R0, the detection resistor R0 is connected in series in an armature main loop, two ends of the detection resistor R0 are connected with a voltage division loop, the voltage division loop is respectively connected with a detection circuit and an amplitude limiting circuit, and the detection circuit is connected with a zero setting filter circuit; the voltage loaded on the detection circuit is in a safe range through the voltage division loop, the amplitude limiting loop controls a voltage signal input to the detection circuit, the detection circuit outputs a voltage signal reflecting the armature current of the direct current motor, and the change of the current is reflected through the change of the voltage signal. The circuit is simple, practical, good in portability, high in detection precision and low in cost.

The invention discloses an electric automobile tail gate anti-pinch control method based on current and speed of a driving motor, and belongs to the technical field of electric automobile tail gate anti-pinch. The method comprises the following steps: acquiring an armature current signal of the driving motor by adopting a phase current sampling mode, and then acquiring a torque signal calculated by utilizing angular speed through a Hall sensor; according to the anti-pinch control method for the tail gate of the electric vehicle based on the current and the speed of the driving motor, a torque signal calculated by utilizing the angular speed is acquired by adopting a phase current sampling mode and a Hall sensor, so that the magnitude of a threshold value can be dynamically adjusted in real time according to different loads of the tail gate of the electric vehicle; the reliability is improved, whether the motor is stable or not can be judged through threshold value change, a current change threshold value I1 and an angular speed change threshold value N1 are set through an integral method, and the phenomenon that due to the fact that a large amount of noise and coupling information are generated in current sampling signals, signal fluctuation influences are likely to be generated, and anti-pinch misjudgment is caused is avoided.

The invention discloses a multi-rate asynchronous sampling control method for a driving motor of a deep-sea robot. The method comprises the following steps: configuring basic electrical and mechanical parameters of a motor system with a plurality of independent partitions; constructing a parameter matrix and realizing control signal decoupling through structural decomposition; setting a basic sampling period and configuring a differential sampling period which is integral multiple of the basic sampling period for each partition to complete control signal discretization; constructing a selection matrix to determine a control signal sequence under multi-rate sampling; discretizing the parameter matrix and solving a feedback control gain matrix; constructing an autonomous system to describe a rotating speed tracking signal and solving a feed-forward control gain matrix; finally, discrete control voltage is calculated according to a multi-rate period based on the armature current detected in real time, and the motor is driven. Through a multi-rate asynchronous sampling strategy, dynamic characteristics and control requirements of different partitions are effectively matched, and the motor control efficiency and response performance in a deep sea environment are remarkably improved.

This invention belongs to the field of electric vehicle motors, and particularly relates to a flux-controllable hub motor and its design method. This invention simultaneously constructs a "self-leakage magnetic circuit" and an "inter-pole leakage magnetic circuit" on the rotor. By changing the armature current under different operating conditions, the leakage magnetic flux and effective magnetic flux of the motor are jointly adjusted, which helps to improve output torque and widen the speed range. Furthermore, by rationally designing key parameters such as the length of the inter-pole leakage magnetic circuit and the length of the self-leakage magnetic circuit on the motor's leakage magnetic circuit, the d-axis flux linkage is increased in low-speed conditions and decreased in high-speed conditions, ultimately achieving enhanced flux controllability across all operating conditions.

The present invention discloses a control method and device for an electric-assisted bicycle, and the electric-assisted bicycle. These methods relate to the technical field of electric-assisted bicycle control. The method comprises inputting a target parameter and an actual armature current; calculating a target armature current based on the target parameter; inputting the target and actual armature currents into an imgabs0# controller, which outputs a motor control signal; and adjusting the assist torque of the electric-assisted bicycle based on the motor control signal. The imgabs1# controller of the present invention combines the advantages of fast response speed of imgabs2# control with the strong anti-interference capability of imgabs3# control, meeting the high dynamic and robust control requirements of electric-assisted bicycles.

According to the operation principle of the motor, the through-flow conductor rotates under the action of force in a magnetic field, induced electromotive force E generated after rotation is equal to Ce phi n (n is the rotating speed of the rotor relative to the stator, namely the rotating speed difference between the rotor and the stator), and electromagnetic torque T generated after rotation is equal to CT phi Ia (Ia is armature loop current). A voltage balance equation (taking a shunt excitation DC motor as an example) in a motor loop after rotation is U = E + IaRa. (Ra is the internal resistance of the armature circuit). At the moment, if the rotating speed n is reduced, the induced electromotive force E is reduced, and if the input voltage U and the magnetic flux phi in the magnetic field are kept unchanged, the armature current Ia is increased, so that the electromagnetic torque T is increased, and the correctness of the theory is verified by an author through a test. According to the scheme, the motor stator is driven to rotate by inertia force during automobile running, the rotating speed difference n between the stator and the rotor is reduced, and therefore electromotive force E is reduced. As the speed difference between the rotor and the stator is very small, very large torque can be generated in the rotor, and electromagnetic loss is also reduced at the same time.

The application relates to the technical field of motor control, and discloses a torque adjustment control method for a magnetic stirrer based on sample characteristics, which comprises the following steps: acquiring three-phase armature currents and a rotor position signal, converting the three-phase armature currents and the rotor position signal into measured cross-axis currents and measured direct-axis currents by using a coordinate transformation logic; extracting a magnetic deflection angle estimation value reflecting the phase lag degree of a stirrer based on an electromagnetic coupling model; calculating a magnetic deflection angle change rate according to the magnetic deflection angle estimation value in a continuous sampling period; generating a transient compensation current by using a nonlinear compensation operator and combining a real-time synchronous torque coefficient; and superimposing the transient compensation current on the cross-axis current instruction to generate a compensation torque by fine-tuning the rotating angular velocity of the armature magnetic field. The application realizes real-time sensing of load disturbance by using the transient characteristics of the magnetic deflection angle, effectively suppresses magnetic force coupling slip caused by sudden changes in sample characteristics, guarantees the stability of the system, and reduces the invalid temperature rise of the motor.

The invention provides an inner stator W-shaped modular magnetic field modulation hybrid excitation motor, which is used for solving the technical problem that the existing hybrid excitation motor cannot adjust the magnetic field. The motor comprises an outer rotor and a modular stator which are sequentially arranged from outside to inside in the diameter direction, and an air gap is formed between the outer rotor and the modular stator; a winding is arranged in the middle of the modular stator, and armature current and direct-current bias current are introduced into the winding; a plurality of virtual slots are formed in the middle of the outer circumference of the modular stator, a plurality of virtual teeth are generated between the adjacent virtual slots and between the outermost virtual slot and the edge of the modular stator, and permanent magnets are arranged in the virtual slots. According to the invention, the modularized stator and the magnetic field modulation hybrid excitation motor are combined, so that the torque density is improved, and the flexible adjustment of the air-gap magnetic field can be realized at the same time; meanwhile, the stator space contradiction can be relieved, the demagnetization risk of the permanent magnet is reduced, the magnetism adjusting efficiency is improved, and the motor loss is reduced.

The invention discloses a generator and a generator control method realized by using the same. An air gap exists between the stator and the rotor, the fixed part is connected with the stator, the rotating part is connected with the rotor, the rotating part is rotatably connected with the fixed part through a main bearing, the generator further comprises a control circuit, the stator is divided into a plurality of stator modules, and the stator modules are connected with the control circuit. The stator modules are distributed at the same position or multiple positions in the axial direction, the control circuit is electrically connected with armature windings in one or multiple stator modules, and corresponding direct-axis current is superposed in armature current of the armature windings to enhance or weaken a magnetic field at a corresponding air gap, so that radial electromagnetic resultant force is generated for the rotor. The self-weight of the rotating part and load force such as bending moment acting on the rotating part by the outside can be counteracted, so that the fatigue load of the main bearing is reduced, the service life of the main bearing is prolonged, and the operation reliability of a generator system, especially a wind driven generator system is improved.

The invention specifically relates to a dual three-phase permanent magnet synchronous motor winding fault diagnosis and positioning method, and belongs to the technical field of motor fault diagnosis. Comprising the following steps: firstly, collecting armature current and carrying out clark conversion to obtain current components of planes of two sets of windings, calculating a current difference value of the corresponding component, extracting a half-cycle effective value as a fault diagnosis characteristic, and calculating a phase angle of a current vector as a fault positioning characteristic; the method provided by the invention can diagnose whether the winding has a fault on line and determine the type and position of the fault. The method disclosed by the invention is of great significance for improving the operation reliability and the maintenance convenience of the dual three-phase permanent magnet synchronous motor.

The invention provides a permanent magnet synchronous motor for flywheel energy storage, and belongs to the technical field of motor rotor structures. The stator sleeves the rotor, and an air gap is arranged between the stator and the rotor. The rotor fixedly sleeves the rotating shaft. The rotor comprises a rotor iron core, a permanent magnet group, a magnetic bridge, a magnetic barrier group and a magnetic barrier isolation group; the rotor iron core is coaxially assembled on the inner side of the stator iron core, an air gap is formed between the rotor iron core and the stator iron core, the permanent magnet sets are arranged in the rotor iron core, located at the axis position of a rotor straight shaft and connected with the magnetic barrier sets, magnetic bridges are arranged between adjacent magnetic barriers in the magnetic barrier sets, and the multiple magnetic barrier sets are all arranged on the edge of the rotor iron core. And two adjacent magnetic barrier groups are symmetrically arranged on the two sides of the axis of the rotor straight shaft. The magnetic field sinusoidal property can be improved, the iron core loss is reduced, the temperature rise of the motor is reduced, the direct-axis inductance of the motor is larger than the quadrature-axis inductance, the counter electromotive force of the motor is small during no-load, and the corresponding no-load loss is low; and the stable terminal voltage is maintained by adjusting the armature current during loading.

This invention presents a method for improving the torque performance of an electrically excited doubly salient pole motor based on current-coordinated control. By analyzing the influence mechanism of excitation current and armature current on the magnetomotive force, the concept of equivalent current is proposed, and the excitation current and armature current are equivalently converted. Based on this, a current-torque model is established to derive the current distribution ratio that maximizes the output torque, optimizing the allocation of excitation current and armature current. Furthermore, this invention employs an asymmetric current control method, which effectively utilizes reluctance torque for compensation, further improving the average torque and significantly reducing torque ripple. This invention can calculate the optimal current distribution ratio in real time under low-speed and dynamic operating conditions, achieving dynamic adjustment of excitation current and armature current, and significantly improving the torque output capability of the electrically excited doubly salient pole motor. This invention is suitable for applications with stringent requirements for torque output performance, such as aircraft starting systems.

The invention discloses an electric power-assisted bicycle control method and device and an electric power-assisted bicycle, and relates to the technical field of electric power-assisted bicycle control. Target parameters and actual armature current are input; calculating a target armature current according to the target parameter; inputting the target armature current and the actual armature current into a # imgabs0 # controller, and outputting a motor control signal; and according to the motor control signal, the power-assisted torque of the electric power-assisted bicycle is adjusted. The # imgabs 1 # controller has the advantage of high response speed of # imgabs 2 # control and the characteristic of high anti-interference capability of # imgabs 3 # control, and can meet the control requirements of high dynamic nature and high robustness of the electric power-assisted bicycle.

The application belongs to the technical field of vehicle braking system, and discloses a segmented pole arc motor for an electronic mechanical braking system, a use method and a vehicle.The motor comprises a stator and an inner rotor, the stator adopts a split tooth structure, is provided with an alternating current armature winding and a direct current excitation winding, and the rotor is provided with segmented pole arc permanent magnets, so that the motor forms a hybrid excitation structure in which a permanent magnet magnetic field and an excitation magnetic field are superposed.Through segmented optimization of the pole arc of the permanent magnet, the air gap magnetic flux waveform is improved, the cogging torque and torque ripple are reduced, and the running stability is improved; equivalent flux linkage is controlled by adjusting the excitation current, the no-load speed is improved in the braking gap elimination stage, and the armature current and the locked-rotor copper loss are reduced in the clamping force following and maintaining stage.The cogging torque, torque ripple and locked-rotor copper loss are reduced in the structural level and the control level, and the application is suitable for stable and reliable work of the electronic mechanical braking system under various working conditions.

The present invention discloses a multi-rate asynchronous sampling control method for a deep-sea robot's drive motor. The method includes the following steps: configuring the basic electrical and mechanical parameters of a motor system with multiple independent partitions; constructing a parameter matrix and achieving control signal decoupling through structural decomposition; setting a base sampling period and configuring differentiated sampling periods that are integer multiples of the base sampling period for each partition to discretize the control signal; constructing a selection matrix to determine the control signal sequence under multi-rate sampling; discretizing the parameter matrix and solving the feedback control gain matrix; constructing an autonomous system to describe the speed tracking signal and solving the feedforward control gain matrix; and finally, calculating discrete control voltages based on the real-time detected armature current according to the multi-rate period to drive the motor. This multi-rate asynchronous sampling strategy effectively matches the dynamic characteristics of different partitions with the control requirements, significantly improving motor control efficiency and responsiveness in deep-sea environments.

The stator (20) has a stator core (30) provided with an armature slot (35a) and an excitation slot (35b), an armature winding (40) housed in the armature slot (35a), an excitation winding (50) housed in the excitation slot (35b), and a first excitation magnet (70). The armature winding (40) generates a rotating magnetic field that rotates the rotor (10) by being supplied with an armature current (i40). The excitation winding (50) generates excitation magnetic flux (M50) by being supplied with an excitation current (i50). The first excitation magnet (70) is capable of changing the magnetic force using the excitation magnetic flux (M50).

The invention discloses an electric bicycle motor health assessment system based on multi-sensor fusion, and particularly relates to the technical field of electric bicycles, comprising an intelligent sensor acquisition module for acquiring armature current, terminal voltage, winding temperature and magnetic field change; the data fusion processing module generates a fusion signal sequence representing the transient behavior of the motor through time domain-frequency domain collaborative fusion based on an adaptive weighted multi-source fusion algorithm; the motor health state modeling module constructs an electromagnetic performance, thermal-electric coupling and vibration response multi-physical field coupling health assessment model, and generates a motor health measurement index through cross consistency correction; the adaptive diagnosis output module generates a health level, and triggers a dynamic threshold re-calibration mechanism when the health level is abnormal. According to the method, multi-dimensional and high-precision motor health assessment is realized, the full-load working condition and the full life cycle of the motor are adapted, the rate of missing report and false report is reduced, a precise basis is provided for maintenance, and the problems of single traditional assessment method, poor adaptability and the like are solved.

The invention relates to an induction door brake control method. A brake control method for an induction door comprises the following steps that (1) an induction door controller reads the real-time rotating speed of a motor, the door opening stroke and the door closing stroke of a door body in the operation process are calculated, the brake motor is braked when the door body enters the door opening and door closing slow-moving distance, the brake stroke S is smaller than the door opening and door closing slow-moving distance, and then the door body is braked; the rotating speed of the motor is instantaneously reduced to a door opening and closing slow-moving speed range; and (2) sampling bus voltage in the braking process of the motor in real time, and when the bus voltage exceeds threshold voltage, reducing terminal voltage U at two ends of a motor winding to enable the motor to enter a generator mode, so that armature current I is reversed, braking electromagnetic torque is generated, and a motor rotor is decelerated. The system has the advantages that the rotating speed of the motor can be reduced so as to reduce the door opening and closing slow-moving speed, so that door post collision or double door collision is avoided, voltage pumping can be prevented, the system voltage can be stabilized, and electronic components of the controller can be protected.

The embodiment of the present disclosure provides a kind of thermal parameter identification and permanent magnet temperature fast prediction method, equipment and medium, belong to data identification technical field, specifically include: analysis motor structure, abstract main thermal path node;Initial thermal resistance network is constructed;Fitting copper consumption change formula;Fitting iron consumption change formula;According to initial thermal resistance network, copper consumption change formula and iron consumption change formula, construct transient temperature solution matrix;Motor is respectively carried out multiple different armature current, rotational speed temperature rise test;According to test result and transient temperature solution matrix, using particle swarm algorithm to the thermal resistance and heat capacity in initial thermal resistance network are carried out parameter identification and are optimized based on least square objective function, solve the target thermal resistance network of motor;Based on target thermal resistance network, copper consumption change formula and iron consumption change formula, combine motor working condition information, the permanent magnet temperature of motor is carried out real-time prediction.Based on the scheme of the present disclosure, improve the prediction efficiency, accuracy and real-time.

The application relates to the technical field of permanent magnet motors, in particular to a saliency ratio reversible degree enhanced permanent magnet motor and a design method thereof. The permanent magnet motor comprises a rotating shaft, a rotor sleeved on the rotating shaft, and a stator coaxially sleeved on the outside of the rotor. Eight trapezoidal magnetic barriers with the centers on q axes and eight bread-type permanent magnets with the centers on d axes are staggeredly embedded in the rotor along the circumferential direction. The bread-type permanent magnets are magnetized along the thickness directions and the magnetization directions are opposite. A bulb-type magnetic barrier in contact with the bread-type permanent magnet is arranged on the two sides of each bread-type permanent magnet. The application ingeniously introduces multiple variable magnetic resistances in the rotor by changing the armature current under different working conditions, instead of a single magnetic resistance, so that the target of enhancing the saliency ratio reversibility under all working conditions is achieved while the magnetic flux leakage and the effective magnetic flux of the motor are changed, and the performance requirements of different working conditions can be met.

The invention relates to the technical field of motors, in particular to an outer rotor brushless motor suitable for an environmental electric appliance and a pole slot matching method of the outer rotor brushless motor. Comprising a rotor assembly and a stator assembly. The rotor assembly comprises a rotor casing and rotor magnetic steel fixed on the inner wall of the rotor casing, and N poles and S poles of the rotor magnetic steel are uniformly distributed in a staggered manner; the stator assembly comprises a stator iron core and an armature winding wound on the stator iron core; the number of pole pairs of the rotor magnetic steel is P, and P is an even number greater than 7; the number of pole teeth of the stator core is Z, and Z is an integer greater than 12 and can be exactly divided by 3; according to the structure and the method, the number Z of pole teeth of a stator core is matched with the number P of pole pairs of rotor magnetic steel to suppress electromagnetic vibration caused by armature current harmonic waves and reduce cogging torque, so that the outer rotor brushless motor can suppress the electromagnetic vibration caused by the armature current harmonic waves and reduce the cogging torque; the mute performance of the motor is improved, the operation noise is reduced, and the motor can be better suitable for environmental electric appliances.

According to the electric excitation doubly salient motor torque performance improving method based on current coordination control, the concept of equivalent current is provided by analyzing the influence mechanism of excitation current and armature current on magnetomotive force, and equivalent conversion is carried out on the excitation current and the armature current. On the basis, a current-torque model is established, so that the current distribution ratio enabling the output torque to be maximum is deduced, and distribution of exciting current and armature current is optimized. In addition, an asymmetric current control method is adopted, and the strategy effectively utilizes the reluctance torque for compensation, so that the average torque is further improved, and the torque pulsation is remarkably reduced. According to the method, the optimal current distribution ratio can be calculated in real time under the low-speed and dynamic working condition, dynamic adjustment of the exciting current and the armature current is achieved, and the torque output capacity of the electro-magnetic doubly salient motor is remarkably improved. The method is suitable for application occasions with strict requirements on torque output performance, such as an aviation starting system.