830 results about "Electromagnetic torque" patented technology

The invention discloses a dual three-phase permanent magnet synchronous motor PWM modulation method and device, solves the problem of how to suppress equivalent odd switch harmonic waves of a dual three-phase permanent magnet synchronous motor driving system, and belongs to the field of motor driving noise suppression. According to the invention, a six-phase CHB drive circuit is adopted to respectively drive a phase winding of a dual three-phase permanent magnet synchronous motor; each phase of CHB driving circuit is formed by cascading N single bodies, and each single body is a full-bridge circuit powered by an independent bus power supply; unipolar carrier phase-shifting modulation is carried out on the dual three-phase permanent magnet synchronous motor by using a six-phase CHB driving circuit, a full-bridge circuit in each single body is decomposed into two half-bridges by the unipolar carrier phase-shifting modulation, two half-bridge modulation waves are staggered by 180 degrees, each carrier single body is sequentially expanded according to pi / N, and the carrier group phase of a second group of three-phase windings is integrally lagged by theta c2; and # imgabs0 # zeta is the phase belt angle of the dual three-phase permanent magnet synchronous motor. According to the invention, frequency multiplication of 4N times of equivalent switching frequency in the aspect of electromagnetic torque can be realized.

The invention discloses an automatic quality-supplementing correction method and system for the unbalance amount of a fan, and the method comprises the following steps: collecting geometric parameters and material characteristics in a static state of the fan, and constructing a mechanical distribution model of the fan; the method comprises the following steps: collecting vibration signals and airflow characteristics in real time in a dynamic operation state, calculating the amount of unbalance in operation and decomposing the amount of unbalance into a primary component and a secondary component; on the basis of the unbalance prediction trend, determining a quality supplementing range, carrying out multi-point quality supplementing operation through a dispensing technology, and monitoring a quality supplementing effect by using an optical fiber sensor; and if the residual unbalance amount after quality supplementation still exceeds the standard, real-time compensation adjustment is carried out through the electromagnetic torque regulation and control module. Full-process automatic correction from static state to dynamic state and from quality supplement to fine adjustment is achieved, the method has the advantages of being real-time, accurate and intelligent, vibration and noise in the fan operation process can be effectively reduced, the operation stability of equipment is improved, and the service life of the equipment is prolonged.

The provided is flux-weakening control method and system for the salient pole offset permanent magnet synchronous motor. The method includes determining the given value of electromagnetic torque according to the actual speed and the given target speed; calculating the current trajectories of MTPA and MTPV in dq coordinate system; obtaining the d′q′ coordinate system by rotating the coordinate system, and calculating the current trajectory of MTPA and MTPV in the d′q′ coordinate system to obtain the characteristic current; judging whether it is necessary to turn on the flux-weakening control, and outputting the direct axis current compensation when it turns on; judging the flux-weakening area of the motor; and generating the space vector pulse width modulation signal to drive the motor to realize the full speed range flux-weakening speed regulation of the salient pole offset permanent magnet synchronous motor.

The invention discloses a high-precision model predictive current control method suitable for a dual three-phase permanent magnet synchronous motor, which comprises the following steps of: deducing a current discrete model of the dual three-phase permanent magnet synchronous motor by considering the change of a rotor position in a control period; constructing a candidate virtual voltage vector set consisting of 24 virtual voltage vectors and zero vectors, wherein the voltage components of the 24 virtual voltage vectors are 0 on a voltage vector xy plane; taking the error squares of the dq-axis current and the xy-axis current of the dual three-phase permanent magnet synchronous motor at the end of each control cycle as evaluation indexes, constructing a cost function, and evaluating the errors of the dq-axis current and the xy-axis current corresponding to different voltage vectors in the candidate virtual voltage vector set at the end of each control cycle by using the cost function. And screening to obtain a voltage vector with the minimum cost function and outputting the voltage vector. The method has smaller dq-axis current tracking error and electromagnetic torque tracking error when the motor operates at a low carrier wave ratio, and improves the steady-state performance of motor operation.

The embodiment of the invention relates to the technical field of permanent magnet synchronous motor control, and particularly provides a permanent magnet synchronous motor belt speed restarting method based on zero current control, a computer readable storage medium and computer equipment. The belt speed restarting method comprises the following steps that the stator current of the permanent magnet synchronous motor is adjusted to zero, and the rotor position and rotating speed information of the permanent magnet synchronous motor are preliminarily estimated; the electromagnetic torque of the permanent magnet synchronous motor is adjusted to zero, and the preliminarily estimated rotor position and rotating speed are accurately estimated; and finishing belt speed restarting of the permanent magnet synchronous motor by adopting a position sensorless control strategy corresponding to the rotating speed according to the accurate estimation result of the rotor position and the rotating speed information. With such a configuration, it is possible to improve the accuracy of position information and effectively suppress current shock during tape speed restart.

The invention discloses a low-rigidity heavy-load permanent magnet synchronous motor flexible system structure resonance suppression method, and relates to the technical field of permanent magnet synchronous motor control, and the method comprises the steps: carrying out the dynamic filtering of an input position signal through setting a TD tracking differentiator, and generating a smooth planning instruction and a differential signal thereof; based on the planned instruction differential signal, a speed feed-forward control method is adopted to introduce feed-forward compensation in a position closed loop; constructing a disturbance observer according to the electromagnetic torque equation of the motor, estimating the actual wheelbase of the system in real time, and performing disturbance compensation; based on system resonance characteristics, an IP control method is adopted to perform pole assignment, and proportional gain and integral gain are set to suppress structure resonance and optimize closed-loop response. According to the method, a relatively good resonance suppression effect can be achieved without displacement, speed or acceleration signals of a load end and information such as very accurate load resonant frequency, relatively good dynamic response is achieved, and the requirement on hardware is reduced.

The invention discloses an electro-magnetic doubly salient motor torque ripple suppression method based on harmonic double closed-loop control, and the method comprises the steps: constructing the harmonic double closed-loop control of a torque ripple outer ring and a current harmonic inner ring in an electro-magnetic doubly salient motor current source type drive system of a multiplexing excitation winding; a torque pulsation outer ring observes electromagnetic torque through a model reference adaptive method, pulsation components of the torque pulsation outer ring are extracted in combination with an adaptive notch filter, and a current harmonic inner ring given value is output through closed-loop regulation; the current harmonic inner ring extracts harmonic current by constructing a harmonic space decoupling transformation matrix and combining with a rotating coordinate system of corresponding subharmonics, current harmonics counteracting torque pulsation of the electro-magnetic doubly salient motor are generated through closed-loop adjustment, and the output characteristic of the motor is improved. According to the method provided by the invention, the torque ripple amplitude can be suppressed in a closed-loop manner, the given value of the harmonic current can be automatically adjusted, specific current harmonic injection is realized, the output torque ripple of the electro-magnetic doubly salient motor is eliminated, and the problems that a traditional harmonic injection method is not matched under different operation conditions of the motor and depends on motor parameters are solved.

The invention relates to the technical field of wind driven generator driving control, and discloses a wind driven generator rotor turning-over driving control method based on torque and rotating speed cooperation, which comprises the following steps: before operation, controlling a motor to execute forward and reverse quasi-static micro-motion, and collecting an average electromagnetic torque; pure gravity and friction components are separated by using torque arithmetic sum and difference, gravity model gain is corrected, and friction compensation is configured; a feed-forward torque is calculated in combination with a real-time angle, and friction compensation and speed loop feedback are superposed to generate a current instruction; according to the method, gravity and friction are decoupled through physical symmetry, model parameter errors are eliminated, hidden dangers of integral lag and out-of-control rotating speed when the variable polarity load passes through a dead point are avoided, and stability and safety of the turnover process of the hundred-ton rotor are ensured.

The invention discloses a method and device for restraining shaft system torsional vibration of a net-forming type double-fed fan under the variable wind speed. The method comprises the steps that a mathematical model of the electromagnetic torque-rotating speed difference of the net-forming type double-fed fan is constructed; drawing an electromagnetic torque-rotating speed difference Bode diagram according to the mathematical model; according to the mechanical parameters of the wind turbine and the motor, the shafting natural oscillation frequency of the doubly-fed fan is calculated, and stability analysis is conducted on damping of the shafting natural oscillation frequency in combination with the Bode diagram; drawing a small-signal model block diagram according to the mathematical model; analyzing the small-signal model block diagram to obtain an analysis result that a current loop provides a coupling path for the rotating speed and the active power; according to a stability analysis result and an analysis result of the small-signal model block diagram, negative damping brought by an operation area is weakened by reducing current loop bandwidth, so that the risk of torsional vibration of the shaft system is reduced.

The invention discloses an adaptive power control method for a duplex-winding induction generator system, and belongs to the technical field of generator control. The double-winding induction generator system is composed of a double-winding induction generator, an energy storage unit, a static excitation converter and a diesel engine. According to the self-adaptive power control method, control winding current is decoupled into excitation control and electromagnetic torque control through coordinate transformation based on rotor flux linkage orientation, independent adjustment of output power of the generator is achieved, passive regulation and control of power of an energy storage unit are achieved through control of electromagnetic torque of the generator, and the self-adaptive power control method is achieved. The problem that the control freedom degree of a single converter system is insufficient is solved. Besides, according to the control method adopted by the invention, a dynamic planning-based generator / energy storage unit power distribution strategy with minimum fuel loss as a target is adopted, so that the generator is ensured to always work in a high-efficiency interval of the diesel engine within a wide load change range, and the power generation cost is remarkably reduced.

The invention relates to the technical field of reluctance motor intelligent control, and discloses a switch reluctance motor intelligent control system and method, and the system comprises a collection module which is used for collecting the inductance, flux linkage and winding current of a magnetic circuit, and a data processing module which is used for processing the collected data, calculating the angular position of a rotor, and outputting an electromagnetic torque. The system comprises a switch reluctance motor, a torque monitoring unit used for monitoring electromagnetic torque of the switch reluctance motor, a control module used for controlling operation of the motor, a fault monitoring module used for monitoring abnormal conditions, and an energy recovery module used for recovering energy generated during braking of the motor. Parameters such as motor torque and angle can be dynamically adjusted according to the motor operation state, and the operation efficiency and response speed of the motor are improved.

The invention relates to a non-inductive FOC open-loop to closed-loop switching method and device for an electronic water pump and a vehicle. The method comprises the steps that a rotor is pre-positioned; starting an open loop I-F; switching condition judgment; estimating the rotor speed based on an observer, calculating a normalization factor, and obtaining a mixed scale factor through cubic polynomial operation; acquiring an open-loop current instruction of a q axis and a closed-loop current instruction output by a closed-loop speed PI regulator; performing weighted synthesis on the two paths of current instructions according to the mixing scale factor to obtain a temporary target current instruction, and applying a change rate limit to obtain a final current instruction output in the current period; the original angle error of the observer estimation angle and the open-loop slope angle is calculated and normalized, the allowable adjustment step length and direction of the round are dynamically determined, and the angle correction amount of the round is generated and superposed to the open-loop slope angle to update the rotor angle reference value; and closed-loop switching is completed. According to the invention, the problems of electromagnetic torque impact and rotating speed fluctuation caused by instruction step change are solved.

The present invention provides a rotor punching, a rotor core, a rotor, a motor, and a vehicle. The rotor punching is provided with a plurality of mounting slots for mounting permanent magnets. A pole arc region is defined between the portion of any mounting slot adapted for the permanent magnet and the outer periphery of the rotor punching. A magnetic isolation bridge is provided on both sides of any pole arc region along the circumferential direction of the rotor punching. A plurality of through holes are provided in any pole arc region, and the plurality of through holes are distributed at both ends of the pole arc region adjacent to the magnetic isolation bridge. The rotor punching provided by the present invention optimizes the rotor magnetic field distribution by providing through holes at the ends of the magnetic isolation bridges on both sides of the pole arc region, effectively weakening the quadrature-axis armature reaction, significantly improving the motor torque pulsation, and also enhancing the electromagnetic torque of the motor to a certain extent, thereby improving the motor's operating performance.

A motor includes a stator having a winding that when selectively energized produces an electromagnetic field within a rotor cavity, and a rotor disposed within the rotor cavity of the stator and in electromagnetic communication with the winding and the electromagnetic field. The rotor includes a drive shaft, a rotor body that extends around the drive shaft and that defines a plurality of reluctance voids, and magnet inserts that are disposed within the reluctance voids. The magnet inserts occupy at least a portion of a space defined by the reluctance voids. The magnet inserts and the reluctance voids cooperate with the electromagnetic field to produce an electromagnetic torque.

According to the coreless motor provided by the invention, three groups of hollow coil groups are uniformly arranged on the inner circumferential wall of a driving cavity in a surrounding manner, the coils as stator parts do not contain iron cores, and the two ends of the coils are not communicated with each other, that is, each group of coils is electrically independent, so that a three-phase six-wire driving mode is realized. The full-bridge driving structures arranged in the driving cavity are connected to the two ends of each set of coils respectively, each full bridge controls one set of coils, and therefore the current direction and amplitude of each set of windings can be independently adjusted. When the motor is powered on, the hollow coil generates an alternating magnetic field under the action of current, and interacts with a rotatable magnetic driving piece located in the axis direction of the motor to form electromagnetic torque so as to drive the magnetic driving piece to rotate. The magnetic driving part is arranged around the axis and surrounded by the coil, and good magnetic flux coupling and stable rotation output are achieved. And in cooperation with a full-bridge driving structure, three-phase six-wire independent control is supported, the driving freedom degree is higher, the current waveform can be finely adjusted, and high-precision servo control is achieved.

The invention discloses a direct-driven fan system impedance modeling method considering frequency coupling, and the method comprises the steps: S1, obtaining a mathematical expression of a blade tip speed ratio and output power according to a wind turbine airflow model of a direct-driven fan; s2, according to equivalent circuit topology modeling under a dq coordinate system of the permanent magnet synchronous motor, obtaining an expression of electromagnetic torque and electromagnetic power; s3, according to the control structures of the machine-side converter and the grid-side converter of the direct-drive fan, modeling is carried out respectively, and an equivalent admittance mathematical expression of the machine-side converter and six disturbance admittance expressions in the direct-drive fan are obtained; and S4, based on the mathematical expressions of the output power, the electromagnetic power, the equivalent admittance and the disturbance admittance obtained in S1, S2 and S3, establishing the equivalent admittance / impedance of the direct-drive fan system. According to the method, multi-time-scale control and full-working-condition frequency domain port characteristics of the direct-driven fan system can be effectively represented, and the equivalent impedance model can accurately analyze the stability of the system.

The invention discloses a wind driven generator large-torque transmission chain resistance increasing control method and system, and relates to the technical field of wind driven generator resistance increasing control. The method comprises the steps that operation parameters of a wind driven generator are collected in real time and preprocessed; calculating a rotation fluctuation frequency set and a corresponding amplitude spectrum of the current time window, and tracking and locking the dominant vibration frequency; constructing a fan state space prediction model containing the torsional vibration state of the transmission chain, outputting the predicted variable quantity of the torque of the transmission chain in the next control period, constructing a filter bank based on the dominant vibration frequency, performing filtering compensation on the predicted variable quantity, and generating an electromagnetic torque given value; and performing phase lead compensation on the electromagnetic torque given value, generating a control instruction, sending the control instruction to the wind power converter, and controlling the wind power generator to output the corresponding electromagnetic torque by using the wind power converter. Through systematic multi-link cooperative processing, the vibration suppression effect and the operation stability of the transmission chain can be comprehensively improved.

The present invention relates to a five-degree-of-freedom ultra-high-speed bearingless permanent magnet motor. Both ends of a cylindrical solid permanent magnet are respectively connected to a rotating shaft. A casing is installed outside the cylindrical solid permanent magnet. A stator core is fixedly installed on the casing. A set of torque windings is embedded in the bottom layer of the stator core, and two sets of suspension windings are embedded in the upper layer of the stator core. End covers are fixedly installed on both sides of the casing. Auxiliary bearings are installed between the end covers and the rotating shaft. Passive permanent magnet bearings are nested on both the end covers and the rotating shaft. The present invention is reasonably designed, integrating a magnetic suspension bearing and a permanent magnet motor into one. While the motor generates an electromagnetic torque capable of driving the rotor to rotate, it can also generate a radial suspension force to overcome the rotor gravity and unilateral magnetic pull force, simplifying the motor structure and shortening the axial length of the motor. The double suspension windings and the axial passive permanent magnet magnetic bearing achieve five-degree-of-freedom control, increasing the rotor stiffness and critical speed of the ultra-high-speed motor, and improving the operation stability and anti-disturbance ability.

The invention discloses a wind power plant equivalent virtual inertia identification method based on symbol regression, and relates to the technical field of novel power system frequency safety and stability, and the method comprises the steps: S1, building a doubly-fed fan inertia response dynamic mechanism model containing comprehensive inertia control; according to the method, the problems of lack of physical mechanisms, poor evaluation interpretability and the like of an equivalent virtual inertia evaluation method for a current wind power plant are solved, the method is based on system operation data and is associated with an inertia response dynamic mechanism model, and the interpretability of a system physical process is reserved; a sparse dynamic modeling method is adopted, an input-output linear combination feature library of system electromagnetic torque-rotor rotating speed change is constructed, sparse solution of parameters is achieved through a sequence threshold value least square algorithm, and the equivalent virtual inertia of the wind power plant is obtained through evaluation. According to the method, model priori knowledge and operation data are fully applied, and the evaluation result is high in accuracy and high in interpretability.

The invention relates to the field of permanent magnet synchronous motor control, in particular to an RANF adaptive harmonic suppression method based on dustpan line optimization, which comprises the following steps: S1, establishing a d-q axis control model for a permanent magnet synchronous motor, listing voltage, current and electromagnetic torque equations, giving a harmonic current equation, and adopting an ANF adaptive notch extraction algorithm to obtain a harmonic current control model for the permanent magnet synchronous motor; obtaining estimated values of specific-order harmonic amplitude and phase, and generating harmonic compensation quantity from the estimated values by adopting a PI regulator so as to realize a steady-state indifference-free harmonic suppression effect; and S2, in order to solve the problem that the ANF adaptive harmonic suppression algorithm is difficult to follow the d-q axis current rapidly changing along with the direct current amount, an RANF adaptive harmonic suppression algorithm adopting an R regulator is proposed, the ANF following performance is greatly accelerated, and the practicability of the ANF is improved. When the motor load or the rotating speed changes, quick response can be achieved, system instability is avoided, the dynamic stability of the system is remarkably improved, and the application scene of ANF adaptive harmonic suppression in the permanent magnet synchronous motor is widened.

The invention discloses a model-free control method for a driving motor of a deep-sea robot. The model-free control method comprises the following steps: acquiring the position, rotating speed and bus voltage of the motor and phase currents of different stator modules; acquiring a rotating speed sampling value to predict the rotating speed and rotating speed ring disturbance at the next moment; acquiring a rotating speed instruction, calculating an electromagnetic torque instruction by combining the rotating speed and a rotating speed loop disturbance prediction value, converting the electromagnetic torque instruction into a current instruction, and averagely distributing the current instruction to each stator module; injecting current into the d axis, and acquiring a current sampling value to predict current and current loop disturbance at the next moment; obtaining a current instruction and calculating a voltage instruction by combining the predicted values of the current and the current loop disturbance; obtaining a gradient function for an adaptive adjustment system and adaptively adjusting a coefficient based on a finite time gradient descent method; and S3, based on the voltage instruction in the step S3, generating a PWM pulse signal through coordinate transformation and space vector modulation, and driving each stator module inverter to control the operation of the motor.

The invention discloses a BLDC (brushless direct current) driving parameter self-tuning embedded system and method for multiple equipment types, and the method comprises the steps: constructing a BLDC unified mathematical model containing an electromagnetic torque equation, a back electromotive force equation and a mechanical motion equation, and building a nonlinear mapping relation library of motor type identification codes and a key electrical parameter set; a predefined multi-mode excitation signal sequence is injected into the to-be-driven BLDC motor, dynamic response data are synchronously collected, and the dynamic response data are used for representing the characteristics of the key electrical parameter set; based on collected dynamic response data, equivalent inductance and equivalent resistance in a key electrical parameter set are decoupled and extracted through a frequency domain impedance analysis method, and meanwhile, a counter electromotive force coefficient and rotational inertia in the key electrical parameter set are identified by combining time domain counter electromotive force zero crossing point detection with rotating speed differential operation. Based on a motor fingerprint feature library and a fuzzy adaptive architecture, multi-model debugging-free plug-and-play is realized, and stable control performance is maintained under a dynamic working condition.

The invention discloses an LC filtering type permanent magnet motor system prediction flux linkage control method and system and a medium, and belongs to the field of power electronics and power transmission. State variables of an LC filtering type permanent magnet motor system at the k moment are sampled, a discrete state-space equation of the system is established by adopting a zero-order retainer method, and a stator flux linkage vector prediction model is established; obtaining a stator flux linkage vector reference by using the electromagnetic torque reference and the parameters of the permanent magnet motor; constructing a loss function, and solving an inverter optimal control vector reference considering the system voltage constraint; park inverse transformation is referred to for the optimal control vector of the inverter, control pulses are generated through space vector modulation and act on an inverter switching tube, and LC filtering type permanent magnet motor system predictive flux linkage control is completed. According to the method, common control of the torque and the flux linkage can be realized only by controlling the stator flux linkage vector, and excellent torque flux linkage control performance can be obtained without any design parameter.

The invention relates to a transverse magnetic circuit module complementary magnetic flux reverse motor, comprising: a stator assembly comprising a plurality of U-shaped stator cores arranged circumferentially, a front module permanent magnet, a rear module permanent magnet, a front module armature winding and a rear module armature winding; and the rotor assembly comprises a front rotor module and a rear rotor module which are axially distributed and have the same structure, rotor salient pole teeth are respectively arranged on the inner side surfaces of the front rotor module and the rear rotor module along the circumferential direction, and the rotor salient pole teeth on the front rotor module and the rotor salient pole teeth on the rear rotor module are arranged in a staggered manner along the circumferential angle. The electromagnetic torque density is remarkably improved through magnetic circuit topology optimization, more excellent power output characteristics are achieved, meanwhile, armature winding turn chain magnetic flux directions of the front module and the rear module are opposite, the phase difference is 180 deg electrical angle, magnetic linkages of the two modules are complementary, even harmonics of the magnetic linkages are counteracted after synthesis, in addition, the unique stator structure improves the air gap magnetic density of the motor, and the motor efficiency is improved. And the motor power density is improved, and the application and popularization value is extremely high.

The invention discloses a multi-branch power system stabilizer suitable for a wind-thermal bundling system, which adopts a cooperative control structure in which a low-frequency branch and a subsynchronous branch are connected in parallel, and suppresses low-frequency oscillation in a frequency band of 0.1-4Hz through a second-order filtering module, a blocking compensation module and a lead-lag module of the low-frequency branch. And the subsynchronous branch extracts a subsynchronous risk mode based on an inverse transformation matrix of a generator shafting torsional vibration mode quantity, and directionally injects a damping signal in combination with a phase compensation module to suppress subsynchronous oscillation in a frequency band of 10-50 Hz. And the parallel output module performs superposition amplitude limiting on the multi-branch signals and then accesses an excitation regulator to dynamically regulate the electromagnetic torque so as to realize wide-frequency-domain oscillation suppression. Through modal quantity directional control, parameter adaptive setting and multi-branch dynamic decoupling, the problems of insufficient multi-band suppression capability, parameter mismatch, controller conflict and the like of a traditional power system stabilizer in a wind-fire coupling system are solved, and the stability and robustness of a new energy high-permeability power grid are remarkably improved.

The present invention relates to the technical field of intelligent control of reluctance motors, and discloses an intelligent control system and method for a switched reluctance motor, comprising an acquisition module for acquiring the inductance, magnetic flux and winding current of a magnetic circuit, a data processing module for processing the acquired data and calculating the rotor angular position and outputting the electromagnetic torque, a torque monitoring unit for monitoring the electromagnetic torque of the switched reluctance motor, a control module for controlling the operation of the motor, a fault monitoring module for monitoring abnormal conditions, and an energy recovery module for recovering energy generated during motor braking. The intelligent control system and method integrate control strategies and algorithms, and can dynamically adjust parameters such as motor torque and angle according to the operating status of the motor, thereby improving the operating efficiency and response speed of the motor.

The invention discloses a speed-dependent power-assisted control method and device of an electric power steering system and a medium. The method comprises the following steps: acquiring vehicle frequency sweep experiment data; processing the frequency sweep experiment data; frequency response characteristics from steering wheel torque to a motor torque instruction and from motor electromagnetic torque to the motor torque instruction are obtained; establishing a stability controller optimization model, and calculating stability controller parameters at zero vehicle speed; the damping ratio is adjusted, and stability controller parameters under other typical vehicle speeds are calculated; determining a speed-dependent assistance mapping relation; calculating an amplitude margin and a phase margin of the electric power steering system in a main vehicle speed range based on the speed-following power-assisted mapping relation and parameters of a stability controller; and when the amplitude margin and the phase margin meet the minimum threshold requirement, finishing controller design. According to the stability controller, the stability of the electric power steering system can be guaranteed, and meanwhile the expected steering hand feeling defined by the speed-following power-assisted mapping relation can be kept as much as possible.

The invention provides a power battery heating method, a motor controller, a power system, an electric vehicle and a computer program product, and the method comprises the steps: detecting the position of a motor rotor of a driving motor in response to the condition of meeting the heating of a power battery; determining a target winding from the three-phase windings according to the relative position relationship between the position of the motor rotor and each winding in the three-phase windings of the driving motor; and controlling the three-phase full-bridge inverter circuit to alternately work according to three periods so as to generate a heating current on a bus of the power battery, and enabling the phase current of the other two-phase windings except the target winding in the three-phase windings to flow in and the phase current of the target winding to flow out in each period. Thus, the target winding is determined according to the position of the rotor, and then a small current component is generated on the q axis of the motor, so that no high-frequency alternating electromagnetic torque is generated in the heating process, and NVH in the heating process can be reduced.

The invention relates to an electromagnetic transient modeling and simulation method of a permanent magnet synchronous generator, which can reflect various types of internal faults, and the method comprises the following steps: 1, according to different fault types, establishing mathematical models of the permanent magnet synchronous generator in different fault states, and according to the different fault types, establishing a mathematical model of the permanent magnet synchronous generator in the different fault states, according to the different fault types, establishing a mathematical model of the permanent magnet synchronous generator in the different fault states, and according to the mathematical model, establishing a mathematical model of the permanent magnet synchronous generator in the different fault states, and according to the mathematical model, establishing a mathematical model of the permanent magnet synchronous generator in the different fault states, and establishing a mathematical model of the permanent magnet synchronous generator in the different fault states; 2, focusing matrix elements required to be updated according to fault characteristics, and selecting current or flux linkage as a state variable; 3, performing discretization equivalence on the mathematical equation of the permanent magnet synchronous generator by using a backward Euler integral method, integrating two state variables, unifying the model to obtain an equivalent circuit equation, and constructing an equivalent circuit of the permanent magnet synchronous generator; 4, the equivalent circuit of the permanent magnet synchronous generator is connected with an external electrical network, and the equivalent model carries out node admittance matrix iteration solution on the whole circuit based on an EMTDC solver; and updating other concerned electrical information such as the stator current, the rotor current, the electromagnetic torque, the rotating speed, the rotor angle and the like until the simulation is finished.

The invention discloses a motor multi-parameter identification method based on sampling noise excitation and bias compensation, and the method comprises the steps: firstly obtaining the voltage and sampling current of a motor, and enabling the sampling current to comprise sampling noise; then constructing an information evaluation index, and adjusting a proportional parameter of a current controller to improve the identification information amount; then, shaft voltage feed-forward compensation is constructed to suppress electromagnetic torque pulsation; recursion is carried out by adopting a least square method based on the discrete linear parameterization model to obtain a parameter initial value and a covariance matrix; secondly, estimating offset-containing parameters on line, and calculating a sampling noise variance by using an estimated residual error; and finally, obtaining unbiased parameter estimation according to bias compensation iteration updating so as to output online estimation values of stator resistance, direct-axis inductance Ld, quadrature-axis inductance Lq and permanent magnet flux linkage.