402 results about "Permanent magnet linear synchronous motor" patented technology

The invention discloses a sensorless control system of a permanent magnet synchronous motor. The sensorless control system comprises a flux linkage/current state observer and a counter electromotive force measurement module, wherein the flux linkage/current state observer is a sliding mode observer; the sliding mode observer is controlled by a sliding mode variable structure; and the coordinate system of the sliding mode observer is an estimated rotary coordinate system, is rotated at an angular speed and lags behind an electrical angle of the coordinate system. In a control parameter computation module, the error of a rotor position is calculated. The sensorless control system of the permanent magnet synchronous motor, can be used on a low-speed observation occasion and a height observation occasion at the same time and has strong practicability.

The proposed Amlev Self-Regulating System of High Speed Ground Transportation Based on Permanent Magnets and Steel Cores is designated for magnetic levitation, stabilization, and propulsion of vehicles moving without friction. The proposed system comprises subsystems: a Magneto-Dynamic Levitation and Stabilizing Self-Regulating System (MDLSS), and a Permanent Magnet Linear Synchronous Motor (PMLSM). Both systems comprise permanent magnets and steel cores. MDLSS provides levitation and stabilization of vehicle while PMLSM produces propulsion force providing the assigned alternative velocity of the vehicle along the stator winding powered by the current of constant frequency 50 Hz. Each of the subsystems comprises two main parts: a fixed part—guideway/stator including extended steel cores for MDLSS and windings for PMLSM, and moving part—permanent magnets of the levitator for MDLSS and the rotor for PMLSM—both affixed to the moving vehicle. Each of the subsystems is self-regulating and operates without fast response control system. A new model is proposed for measuring destabilizing forces impacting a flying vehicle at its shifts from an assigned trajectory that allows to eliminate the stage of full-scale modeling when designing Amlev system.

The invention provides a method and device for measuring position compensation angles of a permanent magnet synchronous motor rotor, wherein the method comprises the following steps: setting a forcible magnetic field directional angle Theta Force; setting component instruction value of a d shaft voltage as u*d=0; inputting the component instruction value u*q of a q shaft voltage which can enable the permanent magnet synchronous motor to enter into a zero speed shaft locking state; according to the forcible magnetic field directional angle Theta Force, obtaining voltage vectors by virtue of PARK inverse transformation of u*d and u*q; generating a power device pulse-width signal needed by a voltage source inverter by a space vector pulse width modulation (SVPWM) algorithm; driving the permanent magnet synchronous motor to rote to a position of ThetaForcee+90 DEG by the voltage source inverter; obtaining the angle Theta xr read by an absolute encoder mounted on the rotor; and calculating the compensation angle that Theta c= Theta Force+ 90 DEG-Theta xr. The method provided by the invention can be simply, conveniently and easily realized; a current sensor is unnecessary to work, and the flitter is not existed during initial location.

The invention provides a method for acquiring parameters of a permanent magnet synchronous motor (PMSM), which comprises the following steps: measuring direct-current bus voltage; controlling an inverter to output current to the PMSM by adopting a digital hysteresis loop-type pulse modulation demodulation control mode; detecting line voltage and phase current which correspond to input current in the PMSM; and calculating the stator resistance of the PMSM, the magnetic induction strength psif of a permanent magnet excitation flux linkage and/or the inductance value Ld of the d axis and the inductance value of the q axis according to different current output to the PMSM under controlling the inverter. By adopting the method for acquiring parameters of the PMSM, three parameters in the PMSM are accurately calculated, and the control effect of the vector control technology on the PMSM is effectively improved.

The invention provides a switching device of permanent magnet synchronous motor windings. The switching device has n sets of windings corresponding to n main loop units; and with the joint effort of (4n-4) switches, switching of series connection and parallel connection of the n sets of windings is realized. The switching device has the following characteristics: the cost of the switching system is lowered and reliability of the switching system is improved; the motor operation efficiency is improved, the speed regulation range of the motor is expanded, and the demand of the main loop capacity is reduced; the selection principle of the switching rotation speed is provided; and a switching strategy for reducing the transient impulse current during the switching process is also brought forward.

The invention discloses a miniature permanent magnet synchronous motor which comprises a stator and a permanent magnet rotor which have equal number of poles. An alternating current source supplies power to the stator through a switch of a control circuit, and an air gap between the stator and the rotor narrows down from one pole to another pole along the rotating direction so that the axis of each pole of the rotor under free state deflects for an acute angle along the rotating direction by taking the axis of the nearest pole of the stator as the reference. A linear magnetic position sensor is installed at a set position on the circumference of the rotor so as to detect the polarity and the position of the rotor; the control circuit determines the axis direction of the permanent magnetic flux of all the poles of the rotor according to the output of the sensor and by taking the set position as the reference. The control circuit detects the polarity of the voltage supplied to the stator by the power source so as to determine the axis direction of the main fluxes generated by all the poles. The switch switches on the power source half-wave when the motor is started and the intersection angle between the axis direction of the main fluxes and the axis direction of the permanent magnetic fluxes is the above acute angle or when the motor runs and the axis direction of the main fluxes is opposite or approximately opposite to the axis direction of the permanent magnetic fluxes. The motor has good starting performance in preset rotating direction and good operational performance and the control structure of the motor is simple and reliable.

The invention discloses a method for controlling direct torsion/ flux linkage of a permanent magnet synchronous motor. The method comprises the steps of collecting three-phase stator voltage and currents of the motor, and obtaining voltage and currents under a two-phase static coordinate system through three-phase/two-phase static coordinate conversion; calculating actual feedback value of electromagnetism torsion and stator flux linkage according to the voltage and the currents under the two-phase static coordinate system; obtaining initial given value of the electromagnetism torsion through a PI controller according to difference between given rotating speed and feedback rotating speed; obtaining given value of the electromagnetism torsion and the stator flux linkage according to a given electromagnetism torsion and stator flux linkage calculating module; obtaining given voltage on an alpha beta shaft of the two-phase static coordinate system through a given voltage calculating module; generating switching signals of an inverter through space vector pulse width modulation, triggering a switching device of the inverter, and realizing direct torsion/flux linkage control of the permanent magnet synchronous motor. The method realizes low, medium and high speed wide range operation of the permanent magnet synchronous motor, does not need to rotate coordinate conversion, and has the advantages of being convenient to calculate, quick in dynamic response, strong in robustness, and the like.

A transverse flux cylinder type permanent magnet linear synchronous motor relates to the field of motor, and settles the problems of low efficiency, large eddy current loss, complex technique and effect to the control precision and dynamic characteristic. The transverse flux cylinder type permanent magnet linear synchronous motor of the invention comprises a primary stage, a secondary stage and an air gap. The number of phase armature units is S=nm, wherein n is a natural number. The number of axial magnetic poles formed by secondary permanent magnets is P=2i, wherein is a natural number. When no common divisor exists between S and P, the S phase armature units are equally divided to m groups along the axial direction, and each n adjacent phase armature units belong to one phase. When a highest common divisor j exists between S and P, the S phase armature units are equally divided into mj parts along the axial direction, and windings on each adjacent n/j phase armature units belong to one phase. The phase unit armature core tooth pitch taut between two adjacent phase armature units along the axial direction and the pole distance taup along the axial permanent magnet satisfy a relationship mktaut=(mk+/-1)taup, wherein m and k are natural numbers, and m is the phase number of motor. The motor not only can be used as an electric motor, but also can be used as a generator.

The invention relates to an adaptive second-order terminal sliding-mode control system and method. On the basis of comparison of a given speed signal and a feedback speed signal of a servo system of a permanent magnet linear synchronous motor, an error amount is obtained; a terminal sliding mode surface is designed based on the error amount and a super-coiling algorithm controlled by the second-order sliding mode is used for realizing the input of a speed controller; and an adaptive control way is introduced to carry out dynamic adjustment on a control gain of the super-coiling algorithm. Therefore, the rapid response of the system is realized; and the system robustness is improved. With the control method, the system can have the high robustness and the system buffeting can be weakened effectively.

The invention discloses a method for restraining torque ripple of a surface-mounted permanent magnet synchronous motor by use of current harmonic waves. The method comprises steps of performing Fourier decomposition on back EMF waveforms of the permanent magnet synchronous motor to obtain a frequency spectrum of the back EMF and the amplitude of harmonic waves every time; representing current as Fourier series and solving an electromagnetic torque model based on three-phase back EMF and the current expression; classifying the electromagnetic torque according to different components of harmonic waves and solving conditions that the current harmonic waves satisfy during the smallest electromagnetic torque ripple; judging the main sources of the electromagnetic torque ripple and determining numbers, amplitudes and phase positions of the current harmonic waves according to characteristics of the back EMF waveforms; and accessing current containing specific harmonic waves into a three-phase winding of the permanent magnet synchronous motor to restrain electromagnetic torque ripple of the motor. Thus, the electromagnetic torque ripple of the surface-mounted permanent magnet synchronous motor can be effectively restrained; a new idea is provided for restraining of the electromagnetic torque ripple; and the method can be further used for torque ripple restraining of other types of surface-mounted permanent magnet synchronous motor.

The invention discloses a nonlinear interference control method and a nonlinear interface control system for a permanent magnet linear synchronous motor (PMLSM). According to the control method, an online estimated compensating voltage value ud of a wavelets neural network (WNN) is added on the basis of up+uf of the conventional composite feedforward proportional differential control, and the sum of up, uf and ud is used as the control voltage U(t) of a stator of the PMLSM, namely the control voltage U(t) is equal to up+uf+ud. The WNN is a three-layer forward network, and ud is the sum of omega1psi1, omega2psi2, ..., omegajpsij, ..., and omegampsim. A learning signal of the WNN is an output value of a proportional differential controller. The control system comprises a digital signal processing controller, a power driving module connected with the stator of the PMLSM, and a rotor displacement sensor arranged on the PMLSM. The WNN is used for effectively compensating interference such as PMLSM thrust fluctuation and frictional force and errors of a fixed parameter model, and tracking accuracy can be improved by more than 2.7 times; and the control system can be implemented by universal hardware, and is convenient to popularize and use.

The invention provides a control method and system for a permanent magnet synchronous motor. The control method and system are characterized in that firstly, initial given currents are obtained according to the given angular speed and the actual angular speed of the permanent magnet synchronous motor; initial quadrature-axis currents are obtained according to the initial given currents; initial direct-axis currents are obtained according to the initial given currents; first direct-axis currents are obtained according to the initial direct-axis currents and the negative compensation quantity; second direct-axis currents are obtained according to the first direct-axis currents, and the second direct-axis currents are not smaller than a preset lower limit value; given direct-axis voltages are obtained according to the second direct-axis currents; the difference between the first direct-axis currents and the second direct-axis currents is acquired, ratio calculation is conducted on the differencing result, and the quadrature-axis current compensation quantity is acquired through calculation; the difference between the initial quadrature-axis currents and the quadrature-axis current compensation quantity, and first quadrature-axis currents are obtained; given quadrature-axis voltages are obtained according to the first quadrature-axis currents; the negative compensation quantity is acquired according to the given quadrature-axis currents and the given quadrature-axis voltages. The stability of the permanent magnet synchronous motor can be improved, and current oscillation is avoided.

The invention belongs to the permanent magnet synchronous generator technology field, and particularly relates to a method for weakening cogging torque of a permanent magnet synchronous generator. The method for weakening the cogging torque of the permanent magnet synchronous generator includes: firstly, optimizing the shape of a permanent magnet motor tooth so as to reduce the cogging torque; then, optimizing a pole arc coefficient; next, using a magnet pole shifting method to reduce a harmonic component of the cogging torque so as to achieve the purpose of reducing the cogging torque; finally, combining the above three steps so as to minimize the cogging torque, building a finite element model of the permanent magnet synchronous generator, and performing analysis and finite element verification on a provided cogging torque suppression method. The method for weakening the cogging torque of the permanent magnet synchronous generator has the advantages of reducing the cogging torque of the permanent magnet synchronous generator on the premise of slightly influencing other properties of the permanent magnet synchronous generator by changing the shape of the tooth and using an optimal pole arc coefficient method and a magnetic pole shifting method in combination, and then reducing starting resistance torque of a direct drive permanent magnet synchronous wind generator, and improves usage rate of wind energy.

The invention discloses an improved iterative learning control method and an improved iterative learning control system for a permanent magnet linear synchronous motor (PMLSM). The control method comprises the following steps of: calculating the control voltage of a stator of the PMLSM by adopting a time axis and iteration axis superposed iterative control law algorithm; introducing an initial control variable u0 on the time axis of the iterative control law algorithm, and designing an adaptive factor alpha; and adding a feedforward control variable to the (k+1)-iterated control voltage of the PMLSM following an iterative learning law. The control system comprises an embedded controller, a power driving module connected with the stator of the PMLSM, and a rotor displacement sensor arranged on the PMLSM. The oscillation of an initial iteration track is avoided, and an iterative convergence speed is increased; and control accuracy is improved to be 0.55 percent.

The invention discloses a method for measuring parameters of a permanent magnet synchronous motor and belongs to the field of motor parameter measurement. The method includes utilizing the A phase no-load counter EMF (Electromotive Force) of a motor and the electric angular velocity of the motor to obtain a permanent magnet flux linkage, utilizing the wave form of the A phase no-load counter EMF and a position sensor to read the corresponding electric angular positions of the 90-degree angle and 0-degree angle of a motor rotor, changing the connection type of a stator winding, and utilizing the alternating voltage, current and frequency to respectively obtain corresponding direct-axis inductance and quadrature-axis inductance. The apparatus used in the method are conventional apparatus and the method has the advantages of clear physical concept, easy operation, high measurement accuracy and the like.

The invention discloses a rotor of a permanent magnet synchronous motor and the permanent magnet synchronous motor, which belong to the technical field of the permanent magnet synchronous motors, and are designed in order to solve the problems of high leakage flux, low permanent magnet utilization rate, influence on motor performance and efficiency and the like in existing rotor of the permanent magnet synchronous motor. The rotor of the permanent magnet synchronous motor comprises a rotor core, wherein an even number n of tangential permanent magnets are distributed evenly in radial direction on the rotor core, and the same polarities of two adjacent tangential permanent magnets are opposite; radial permanent magnets are arranged symmetrically on two sides of one end of each tangential permanent magnet close to the inner side of the rotor core respectively; every two radial permanent magnets sandwiched between two adjacent tangential permanent magnets have the same polarity in the direction facing to a stator, and a magnetic isolating bridge is arranged between every two radial permanent magnets. The invention further discloses a permanent magnet synchronous motor provided with the rotor. By utilizing the rotor, the leakage flux of the tangential permanent magnets on the inner side of the rotor is reduced, the utilization rate of the permanent magnets is improved, and the motor efficiency and the motor structural intensity are enhanced.

The invention discloses a method for restraining torque pulsation of a permanent magnet synchronous motor. Original reference signals and q axis current signals are adopted, and the method is characterized in that a superposition q axis current compensation method is adopted for restraining the torque of the permanent magnet motor. The q axis current compensation method can be conducted in the following two modes respectively: under the condition that the output torque Te is given, the q axis compensation current can be calculated on the basis of an electromagnetic torque formula; when the electromagnetic torque needed by the motor can not be accurately known, the compensation current can be determined according to a flux linkage formula. According to the method for restraining torque pulsation of the permanent magnet synchronous motor, the control performance of the permanent magnet synchronous motor is improved by increasing the compensation current, the good compensation effect is achieved through a phase shifting link, and through an amplitude limiting link, the compensation effect can be prevented from being affected when current glitches are large, and the protection function is achieved.

The invention provides a torque output control system of a permanent magnet synchronous motor. The system comprises a modulation module, an inverter and the permanent magnet synchronous motor, wherein the modulation module, the inverter and the permanent magnet synchronous motor are electrically connected in sequence. The system further comprises a 3/2 conversion module, a torque calculation module, a required current calculation module, a torque comparator, a torque current compensation integral adjustment module, a torque current adder, a magnetic flow current calculation module, a torque current comparator, a magnetic flow current comparator and a current PI regulating module. On the basis of controlling torque output, and by using actual output torque as a target, the torque output control system is used for calculating torque deviation and correcting the matching relation between magnetic flow current and torque current according to the torque deviation so as to enable motor torque output to track target torque.

The invention discloses a method for identifying permanent magnet flux and quadrature axis inductance of a permanent magnet synchronous motor. The method comprises the steps as follows: designing a filter based on an identification algorithm and calculating identification parameters. The accuracy of the permanent magnet flux and quadrature axis inductance parameters directly influences the control performance of a vector control system of the permanent magnet synchronous motor. But the existence of a saturation effect and the like enables the motor parameters to be non-linearly changed. Therefore, a change curve of the motor parameters is necessarily measured or identified on line. The invention discloses the simple and easy method for identifying the permanent magnet flux and the quadrature axis inductance, and the control performance of the system is improved on the basadopts not increasing the system cost.

The invention belongs to the technical field of vector control of a permanent magnet synchronous motor. Total control current I*s is obtained by adjusting PI (Proportional-Integra) of a given motor rotational speed w*r and a motor rotational speed wr; a basic given current i*sdl of d axis is obtained by control of MTPA (Maximum Torque Per Ampere); current feedback isd and isq of the d axis and q axis are obtained by detection of a current sensor; the given current i*sq of the q axis is equal to square root of the difference of (i*s)2 and (i*sd)2; the given adjustment current DELTAi*sd of the d axis is obtained by passing the current feedback isq of q axis through a flux-weakening control module; the given current i*sd of d axis is equal to the sum of i*sdl and DELTAi*sd; the currents of the d axis and q axis are subjected to decoupling control and voltages u*sd and u*sq are output; and an SVPWM (Space Vector Pulse Width Modulation) inverter is controlled to obtain three-phase alternating current to drive the permanent magnet synchronous motor. Through PI adjustment on the given current i*sq of q axis and the current feedback isq of the q axis, the given adjustment current DELTAi*sd of the d axis is obtained, optimal flux weakening of the permanent magnet synchronous motor is achieved, the flux-weakening control method is easy to understand and implement, control cost is low, and a good flux-weakening control effect is achieved.

The invention discloses a double-stator permanent magnet synchronous motor, and relates to the field of motors. The invention aims at solving problems that a conventional double-stator permanent magnet synchronous motor usually employs a fractional-slot concentrated winding, the number of coils of the fractional-slot concentrated winding is large and the manufacturing cost is larger; and problemsthat the big eddy-current loss of a rotor permanent magnet and the rising of the temperature of the permanent magnet are liable to cause the irreversible demagnetization because the harmonic content of the magnetomotive force of the fractional-slot concentrated winding is large when the power-on frequency of a motor winding is higher and the overload multiples is large. The double-stator permanentmagnet synchronous motor provided by the invention enables the harmonic contents of a synthetic magnetomotive force and the magnetomotive force of two armatures to be small through the correspondingstaggering of double-stator windings, and is small in eddy-current loss of the rotor permanent magnet. Moreover, the end parts of the windings are not overlapped, thereby improving the motor efficiency and reliability.

The invention discloses a permanent magnet synchronous motor unposition sensor control method, which concretely comprises the following steps of: step 10, collecting three-phase voltage of a permanent magnet synchronous motor, switching the three-phase voltage to a dd coordinate system, and obtaining voltage ud and uq in a dq axis; step 20, collecting three-phase current of the permanent magnet synchronous motor, switching the three-phase current to a dq coordinate system, and obtaining current id and iq in the dq axis; step 30, adopting a sliding mode variable structure model reference adaptive system-based algorithm to obtain a rotor estimated electric angle speed and a rotor position of the permanent magnet synchronous motor; and step 40, according to the rotor estimated electric angle speed and the rotor position obtained in the step 30, realizing unposition sensor rotation speed close-loop vector control of the motor. The permanent magnet synchronous motor unposition sensor control method has the advantages of low cost, simple control algorithm, high rotation speed and position estimation speed, high estimation accuracy, and the like.

An apparatus for measuring a position deviation of a rotor of a permanent magnet synchronous motor includes a control unit, a power transformation unit, a rotor position estimator and a calculation unit. The control unit receives a d-axis DC voltage signal and a q-axis AC voltage signal and receives an initial value of the rotor position and a high-frequency signal to output a three-phase command signal. The power transformation unit receives the three-phase command signal and outputs a three-phase control signal for controlling the motor. The rotor position estimator receives a three-phase current feedback signal corresponding to an operation of the motor and generates an estimation value of the rotor position. The calculation unit performs calculation to the initial value and the estimation value to generate a deviation value of the rotor position. Moreover, a method for measuring the position deviation is also disclosed herein.

The invention discloses a permanent magnet synchronous motor simulator considering nonlinear characteristics and a control method thereof. The method includes the steps of outputting three-phase voltages and currents, and obtaining q-axis and d-axis voltage and current components respectively through coordinate transformation and combined with a current cycle electrical angle; obtaining q-axis andd-axis counter electromotive force (EMF) components; establishing a nonlinear permanent magnet synchronous motor mathematical model, taking the q-axis and d-axis voltages and q-axis and d-axis counter EMF as the input to calculate the mechanical angular velocity, electrical angle, motor rotation speed, and q-axis and d-axis currents of a next cycle, and taking the q-axis and d-axis currents as command currents for the closed-loop control of the next cycle; and regulating differences between the command currents and the q-axis and d-axis current components by using a current regulator, and connecting the reference voltage obtained after the inverse Park transformation of the results to an SVPWM modulation module such that a three-phase full-bridge converter actually outputs the command currents. According to the invention, the operation characteristics of various working conditions under the condition of non-linear counter EMF can be effectively simulated, and the tracking without static error of high frequency signals contained in the higher harmonic currents can be achieved.