804 results about "Flux linkage" patented technology

The invention relates to the technical field of motor control, and discloses a hybrid excitation synchronous motor control strategy optimization method and device. The method comprises the following steps: performing mathematical modeling on permanent magnet flux linkage, exciting current and rotor parameters of the hybrid excitation synchronous motor to obtain a state observer equation; collecting current parameters and position parameters, and performing filtering processing to obtain motor operation state parameters; inputting a five-layer deep neural network for current and rotating speed parameter prediction to obtain an optimal current parameter and an optimal rotating speed prediction parameter; constructing a multi-objective function, and solving to obtain a current reference value; inputting the current reference value into a cascade PI controller, and performing voltage regulation through feedforward decoupling control and a space vector pulse width modulation technology to obtain a control voltage signal; and performing performance calculation control parameter optimization on the control voltage signal to obtain a target control parameter, thereby improving the control precision of the hybrid excitation synchronous motor.

According to the permanent magnet synchronous motor sensorless flux linkage estimation method based on the non-linear observer, the stator flux linkage can be accurately estimated by applying the non-linear expansion state observer and the effective flux linkage method in the sensorless mode of the motor. By applying a voltage and current hybrid model, adaptive switching of a voltage model and a current model is realized, and the problems of direct current bias, integral saturation and the like existing in first-order integral of the voltage model are solved; and estimating and compensating noise and disturbance existing in the voltage model by applying a non-linear extended state observer, accurately obtaining a stator flux linkage during operation of the motor, and finally estimating a rotor angle and a rotating speed by using a phase-locked loop. According to the method, the estimated values of the rotor angle and the rotating speed are more accurate, and the sensorless control performance of the permanent magnet synchronous motor is improved.

The invention relates to the field of motor control, and discloses a permanent magnet synchronous motor enhanced active-disturbance-rejection control method based on a superhelix control law, which comprises the following steps of: firstly, establishing a permanent magnet synchronous motor mathematical model by considering load disturbance, current sampling disturbance and flux linkage parameter change disturbance in actual motor operation; according to the mathematical model of the permanent magnet synchronous motor and the mathematical characteristics of the active disturbance rejection controller, constructing an observer equation by using a differential relationship, and solving the problem of observation error accumulation through the differential relationship; a lumped disturbance compensation function is introduced into the observer, the anti-interference capacity of the control system is enhanced, and decoupling of steady-state and dynamic performance control parameters is achieved; and finally, designing a state error feedback control law by adopting a super-spiral sliding mode control law, so that the anti-interference capability of the active-disturbance-rejection controller is further improved, and the inherent buffeting of the system is weakened. A simulation result shows that compared with a traditional PI control method, the control method has better dynamic response performance and anti-interference performance.

The invention relates to the technical field of motor control, and discloses a low-noise flux linkage adaptive feedback control system of a high-speed motor. The system comprises an acquisition module used for acquiring current, voltage and vibration data of a high-speed motor at various operation rotating speeds to obtain operation parameters and noise characteristic data of the high-speed motor; the transformation processing module is used for performing frequency domain orthogonal transformation processing on the operation parameters and the noise characteristic data of the high-speed motor to obtain flux linkage real-time observation data; the self-adaptive analysis module is used for executing multi-mode working condition self-adaptive analysis according to the flux linkage real-time observation data and generating flux linkage control reference values of different rotating speed intervals; and the output module is used for inputting the flux linkage control reference values of different rotating speed intervals into a magnetic-machine coupling control algorithm, and calculating and outputting a motor low-noise driving control signal. According to the method, the problem of magnetic flux path distortion under high-speed operation is effectively solved, and downtime and efficiency loss caused by a traditional off-line calibration method can be avoided.

The invention discloses a hybrid effective flux linkage observer and a permanent magnet synchronous motor control method, device and system. The method comprises the following steps: carrying out Clarke conversion on an obtained three-phase current of the permanent magnet synchronous motor to obtain a current in a static coordinate system, and carrying out park conversion based on rotor position information to obtain a current in a synchronous rotating coordinate system; the effective flux linkage of the permanent magnet synchronous motor is obtained through the hybrid effective flux linkage observer; on the basis of the obtained effective flux linkage of the permanent magnet synchronous motor, dead-zone compensation voltage is obtained through self-adaptive gain dead-zone compensation calculation based on back electromotive force reconstruction, and the rotating speed and the rotor position of the permanent magnet synchronous motor are obtained through phase-locked loop calculation; according to the rotating speed and the rotor position of the permanent magnet synchronous motor, the current under the synchronous rotating coordinate system, the dead zone compensation voltage and the obtained reference rotating speed and reference current, the reference voltage of the motor at the k moment is obtained through a rotating speed loop and a current loop and used for achieving low-speed position-sensorless control over the permanent magnet synchronous motor.

The invention discloses a motor control method, system and device based on a flux observer and a medium, and relates to the field of motor control. In the scheme, a nonlinear flux linkage observer model is constructed in advance, and the input of the nonlinear flux linkage observer model at least comprises q-axis current; then obtaining an electrical angular velocity estimated value and an electrical angle estimated value of the motor through a nonlinear flux observer model; and according to the electrical angular velocity estimation value and the electrical angle estimation value, inputting the electrical angular velocity estimation value and the electrical angle estimation value into operation of a speed loop and a current loop to control the motor. According to the motor control method provided by the invention, the q-axis current is considered in the established nonlinear flux linkage observation model, and the q-axis current is closely related to the dynamic inductance and then is related to the error of the electrical angular velocity estimated value and the electrical angle estimated value; according to the invention, the error of the dynamic inductance to the electrical angular velocity estimation value and the electrical angle estimation value can be reduced, and the accuracy of motor control is improved.

The invention discloses a sensorless model prediction speed control method for an induction motor, and the method comprises the steps: carrying out the modeling of a mathematical model of the induction motor based on a two-phase static coordinate system, and obtaining a mathematical model of the induction motor; constructing a full-order observer, and obtaining an estimated value of the rotating speed of the rotor of the induction motor and an estimated value of the flux linkage through the full-order observer; parameter identification of stator resistance is introduced into a motor rotating speed estimation and model prediction module; establishing a prediction model, predicting the stator flux linkage and the rotating speed at the k + 1 moment, and obtaining a stator flux linkage prediction value and a rotating speed prediction value; and finally, constructing a reduced order load torque observer, carrying out feedforward compensation on a speed outer ring of the control system, and improving the dynamic response of the system. According to the invention, the problem in the prior art that the system performance is reduced and even the system crashes due to sensor faults is solved.

The invention discloses an adaptive current decoupling control method for a sliding mode of a permanent magnet synchronous motor, and the method comprises the steps: designing an extended state observer to observe a d-q axis current and a voltage disturbance term, carrying out the difference between a current observation value and a reference current, and inputting the difference into a non-singular integral terminal sliding mode controller, thereby obtaining a d-q axis voltage; and then the observed d-q axis voltage disturbance term is superposed to form a total d-q axis voltage. And then identifying the d-q axis inductance and permanent magnet flux linkage of the permanent magnet synchronous motor by using a recursive least square method with dynamic forgetting and adaptive regularization factors, and sending the d-q axis inductance into the extended state observer to realize a closed-loop adaptive extended state observer. And after coordinate transformation and space vector pulse width modulation are carried out on the d-q axis total voltage, the d-q axis total voltage is used for driving an inverter to control the permanent magnet synchronous motor. The method improves the current decoupling effect and anti-disturbance capability of the permanent magnet synchronous motor, adaptively adjusts the parameters of the controller according to the change of working conditions, and improves the robustness of the system.

The invention discloses a method and device for eliminating slight stalling of a pump, and belongs to the technical field of motor control. In the pump operation process, the flux linkage change rate of a motor in the pump is obtained, and locked-rotor judgment is conducted on the pump based on the flux linkage change rate; on the basis of the obtained locked-rotor judgment result, according to the locked-rotor state of the pump, selecting to enter a blockage clearing mode; after the pump enters the blockage clearing mode, a pump motor is controlled to operate under the first-level torque condition, the flux linkage change rate of the motor is obtained, and the locked-rotor degree grade of the pump is judged based on the obtained flux linkage change rate; the first-stage torque is larger than the torque of normal starting of the pump; and according to different locked-rotor degree grades and preset corresponding blockage clearing rules, the pump is controlled to execute blockage clearing operation. The capacity of the motor can be brought into full play, the pump can automatically eliminate some slight locked-rotor faults when encountering the slight locked-rotor faults, and the shutdown maintenance frequency is reduced.

The invention discloses an AC excitation system rotor initial position on-line identification method and system, and the method comprises the steps: collecting a stator three-phase voltage signal when a stator is no-load, carrying out the Clarke conversion of the signal, obtaining a voltage component under a static coordinate system, and carrying out the low-pass filtering processing; calculating a stator flux linkage based on the stator current and the processed voltage component, and calculating a rotor flux linkage based on the rotor current; the rotor initial position offset is continuously accumulated through closed-loop adjustment by calculating the stator and rotor flux linkage angle and the phase difference until the phase difference approaches zero, and the accumulated rotor initial position offset is output; and combining the mechanical angle output by the encoder with the accumulated rotor initial position offset to obtain a corrected rotor position angle, and updating the corrected rotor position angle to an excitation system. According to the method, the in-phase characteristics of stator and rotor flux linkages are utilized, and the optimally designed low-pass filter is combined, so that the identification precision of the initial position of the rotor is remarkably improved, and the zero offset of the encoder is effectively compensated.

The invention discloses an iterative phase-locked limit cycle flux observer, a control method, a control device and a control system, and the control method comprises the following steps: collecting alpha-beta axis voltage and current signals of a motor, constructing an IPMSM mathematical model under an alpha-beta axis, and calculating to obtain a counter electromotive force vector of the motor; taking the motor back electromotive force vector as input, acquiring motor rotor flux linkage information through an iterative phase-locked limit loop flux linkage observer, and estimating a motor rotating speed and a position signal according to the motor rotor flux linkage information; and the rotating speed and the position signal of the motor are input into a motor closed-loop control system, so that position-sensorless closed-loop control of the permanent magnet synchronous motor is realized. According to the method provided by the invention, the problem of integral drift or phase lag of a traditional flux linkage observer can be avoided, the influence of direct current bias on flux linkage and position observation precision is effectively suppressed, the dynamic response capability of position sensorless control is remarkably improved, and a position estimation error generated in a dynamic process is suppressed.

The invention discloses a neural network enhanced active-disturbance-rejection current control method for a flux-adjustable permanent magnet synchronous motor, belongs to the technical field of motor control, and aims to solve the problem of current loop performance deterioration caused by dramatic change of motor parameters in the flux adjusting process of the flux-adjustable permanent magnet synchronous motor. The method comprises the following steps: acquiring the current magnetization state and direct-axis current of the motor; based on the magnetization state and the direct-axis current, time-varying parameters of the motor are predicted online in real time through a neural network, and the predicted time-varying parameters comprise direct-axis inductance, quadrature-axis inductance and permanent magnet flux linkage; calculating a feed-forward compensation voltage based on the predicted time-varying parameter; generating a current instruction value by using the predicted time-varying parameter and the feed-forward compensation voltage; generating an active-disturbance-rejection feedback control voltage based on the predicted time-varying parameter and the current command value; and superposing the feed-forward compensation voltage and the active-disturbance-rejection feedback control voltage to obtain a final voltage given value for driving the motor.

The invention discloses a residual magnetism elimination circuit and method for a current transformer, and the method employs a fluxgate principle, applies sine excitation voltage to a secondary winding of the current transformer, extracts a fluxgate signal through a response current, and achieves the detection of the residual magnetism of an iron core of the current transformer. And according to the detected residual magnetism flux linkage information, accurately calculating a voltage parameter required by demagnetization, and generating a degaussing voltage with a specific waveform. And finally, applying the degaussing voltage obtained by calculation to the secondary side of the current transformer, controlling the whole degaussing time to continue at the moment at which the fundamental wave angular frequency can be rotated to + / -90 degrees, and accurately eliminating residual magnetism by utilizing sine waves of a quarter period. According to the method, rapid demagnetization of the iron core of the current transformer can be realized, the reliability and safety of a power system are improved, and demagnetization can be carried out in the running process of the current transformer without offline operation or change of an original transformer structure. The residual magnetism of the iron core is not changed in the detection process, and the normal operation of the current transformer is ensured.

The invention discloses an axial winding complementary type hybrid excitation high-speed magnetic flux reverse motor, and belongs to the technical field of power generation, power transformation or power distribution. The motor comprises a six-slot stator iron core, a four-tooth rotor iron core, a set of annular winding serving as an excitation winding and a set of concentrated winding serving as an armature winding, permanent magnet groups are attached to the inner surface of the tooth part of the stator core, two groups of axial permanent magnets are opposite in polarity, and two groups of circumferential permanent magnets are opposite in polarity; and the rotor iron core is formed by laminating a plurality of rotor iron core sections which have a mechanical angle of 45 degrees in the axial direction. The motor has the magnetic field adjusting capacity and has the advantages of being small in flux linkage, counter electromotive force sine, cogging torque and torque fluctuation, extra rising voltage caused by strong armature reaction during high-speed operation can be reduced through flux weakening, torque during low-speed operation can be improved through flux increasing, and due to the fact that the number of poles is small, loss is small during high-speed and high-frequency operation, and the motor is high in reliability. Compared with other magnetic flux reverse motors, the magnetic flux reverse motor is more suitable for high-speed operation.

The embodiment of the invention provides a sensorless control method, device and equipment for a permanent magnet synchronous motor, and belongs to the technical field of motor control. The method comprises the following steps: obtaining an initial flux linkage observation change model; performing error determination on the initial flux linkage observation change model to obtain a flux linkage observation error model; performing rotor position calculation through the initial flux linkage observation change model to obtain the rotor position of the target motor, and performing variable quantity analysis on the rotor position to obtain the motor rotating speed of the target motor; updating initial model parameters in the initial flux linkage observation change model through the flux linkage observation error model to obtain a target flux linkage observation change model; obtaining a target observation flux linkage and a target two-phase static coordinate system current of the target motor; and performing rotor position calculation on the target observation flux linkage and the target two-phase current through the target flux linkage observation change model to obtain a target rotor position. According to the embodiment of the invention, the rotor position can be calculated for the motor in different operation stages.

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.

Disclosed are systems and methods for motor control using optimal efficiency reference generation. An electronic controller may determine current values for a motor in a rotational reference frame. Each current value may be associated with a dimension of a set of dimensions of the rotational reference frame. The electronic controller may further determine, based on the current values, a flux linkage value for each of the set of dimensions of the rotational reference frame using an optimization cost function that considers motor speed, copper loss, and core loss. The electronic controller may further determine a target flux linkage value for each of the set of dimensions of the rotational reference frame. The electronic controller may then control a power switching network coupled between a power supply and the motor based on the flux linkage values and the target flux linkage values.

The invention relates to a doubly-fed variable-speed pumped storage unit fractional order PID additional frequency control method and system, and the method comprises the steps: building an electrical mathematical model of a doubly-fed induction motor based on a synchronous rotating coordinate system, enabling a stator flux linkage to be aligned with the d-axis direction through employing a stator flux linkage directional control strategy, and enabling the stator flux linkage to be aligned with the d-axis direction; therefore, decoupling adjustment of active power and reactive power output by the unit is realized. The frequency deviation between the power grid common connection point frequency and the rated frequency is obtained and serves as an input signal of the fractional order PID additional controller, the frequency deviation can be effectively restrained under various working conditions, the system stability and the inertia supporting capacity are enhanced, and the method is suitable for auxiliary frequency control of a variable speed pumped storage unit in a high-proportion new energy power grid.

The invention discloses a flux linkage tracking full-speed-domain high-precision predictive current control method for a permanent magnet synchronous motor, and the method comprises the steps: sampling a phase current signal, a position signal and a speed signal of the permanent magnet synchronous motor, and obtaining a dq sampling current through coordinate transformation; calculating a predicted current according to the established tracking discrete model; the sinusoidal variation characteristic and the dynamic transient characteristic of the resistance voltage drop are accurately considered in the current prediction and reference voltage calculation stage, and the resistance voltage drop is accurately represented through accurate feed-forward compensation of predicted current and reference voltage; a driving signal of the inverter is obtained through coordinate transformation and space vector modulation, and full-speed-domain high-precision fast-response current prediction control over the permanent magnet motor is achieved. According to the method, the current flow steady state control error caused by the model error is reduced, the current control precision and the dynamic response performance of the permanent magnet synchronous motor in the full-speed domain are effectively improved, and a high-precision model basis is provided for high-precision position-free control and parameter online identification.

The invention discloses a complex wave-based permanent magnet synchronous motor all-electrical parameter online identification method and device. The method comprises the following steps: analyzing the influence of a voltage error caused by dead zone time on parameter identification, and performing corresponding dead zone compensation; a bias complex wave with a certain amplitude and frequency is injected into the d-axis current, so that the d-axis current meets a parameter identification continuous excitation condition; constructing three groups of effective current slopes through four groups of different input data stored in the steady state of the motor, and identifying three groups of parameters of resistance, direct-axis inductance and quadrature-axis inductance by referring to a d-axis voltage equation and adopting a least square method with a forgetting factor; and finally, updating the identified three groups of parameters as known quantities in a q-axis voltage equation in real time, storing two groups of different input data to construct a group of effective current slopes, and identifying flux linkage parameters by adopting a least square method with a forgetting factor. According to the method, the under-rank problem of all-electrical parameter identification of the motor is solved, the identification precision is high, and the identification error of each parameter is about 3%.

The invention relates to the technical field of torque control, in particular to a motor torque control method, system, equipment and medium, and the method comprises the following steps: obtaining a winding temperature rise and rotating speed signal through a temperature and rotating speed sensor, calculating the resistance and flux linkage offset, and filtering to obtain a torque evaluation parameter; the acceleration and inertia reference are compared to obtain inertia disturbance, a least square method is combined to calculate a compensation coefficient, a current component is corrected to synthesize an expected torque, a torque error is calculated to judge whether the torque reaches the standard or not, and a torque control result is output and optimized. Load changes are quickly responded through filtering and inertia disturbance recognition, differential calculation is conducted on the relation between acceleration and a correction coefficient to act on a current component, torque output is stable, coefficient iterative optimization is promoted through error comparison, fluctuation is reduced, efficiency is improved, and reliable control over the motor under the complex working condition is kept.

The invention discloses a torque ripple suppression method and control device based on permanent magnet flux linkage harmonic identification, and the method comprises an online identification process and a torque ripple suppression process, and is used for suppressing the torque ripple of a built-in permanent magnet synchronous motor. The online identification process comprises a permanent magnet flux linkage harmonic identification step, a dead zone voltage harmonic compensation step and a harmonic component extraction step; the torque ripple suppression process comprises the steps of inputting a pre-recognized flux linkage harmonic lookup table to obtain fifth and seventh permanent magnet flux linkage harmonics, predicting torque ripple according to a magnetic co-energy model, outputting an optimal stator current reference value, obtaining sixth harmonic voltage for suppressing the torque ripple, and driving the motor by using an SVPWM strategy after a fundamental component and a harmonic component are superposed.

The invention provides a motor detection method and device, electronic equipment and a storage medium, and the method comprises the steps: controlling a motor to operate under a first identification parameter, and calculating a phase resistance value of the motor under the first identification parameter; controlling the motor to operate under a second identification parameter, and collecting a sinusoidal current response signal of the motor under the second identification parameter; calculating a d-axis inductance value and a q-axis inductance value based on the sinusoidal voltage excitation signal, the sinusoidal current response signal and the phase resistance value; the motor is forcibly dragged in a current-frequency ratio control mode, so that the rotating speed of the motor is increased to the target rotating speed; and calculating the flux linkage coefficient by combining the steady-state voltage and the current value of the motor at the target rotating speed with the d-axis inductance and the q-axis inductance. According to the method, the detection precision of the motor parameters can be improved.

The invention discloses a control method for a network-forming type modular multilevel converter and related equipment. Under the condition of not changing a control system of the network construction type modular multilevel converter, the synchronization stability of the network construction type modular multilevel converter in a strong power grid can be greatly improved only by subtracting a three-phase flux linkage per unit value at an outlet of a grid-connected point filter from a three-phase reference voltage per unit value generated by the control system. A three-phase flux linkage calculation mode at an outlet of a filter of the modular multilevel converter is that an average value is subtracted from an integral of a per-unit value of a three-phase voltage instantaneous value. The method can be realized only by subtracting the three-phase flux linkage value from the three-phase voltage reference value generated by the control system and feeding the calculation result into the modulation link, the implementation mode is simple, and the method is suitable for all existing modularized multi-level converter network tracking and network construction control systems. After the flux linkage feedback control provided by the invention is applied, the synchronous stability of the converter can be greatly improved, and the flux linkage feedback control method can be widely applied to the technical field of power system automation.

The invention discloses a synchronous motor sensorless control method based on a Newton-Raphson predictive phase-locked loop, and relates to the technical field of motor control. The invention aims to solve the problems that an existing position-sensorless control method is limited by extra loss and noise caused by high-frequency signal injection in the aspect of position signal extraction and poor dynamic performance caused by a traditional phase-locked loop technology, and a prediction phase-locked loop technology needs a large amount of iterative operation for solving a cost function. According to the method, the flux linkage estimation value of the alpha-beta coordinate system is observed, the filtered flux linkage estimation value of the alpha-beta coordinate system is reconstructed, and then a cost function is constructed; when the number of iterations in the current motor control period does not reach the maximum, updating a rotor position angle by using a Newton method, and further updating a cost function; and when the number of iterations in the current motor control period reaches the maximum, calculating a convergence angle in the current motor control period by using an improved Newton method, and calculating an angular velocity estimated value, thereby realizing position-sensorless control of the synchronous motor.

The invention discloses an electromagnetically adjustable variable flux disc type motor, belongs to the technical field of motors, and aims to solve the problems of complex control and low safety when the rotating speed of the motor is increased in a weak magnetic intervention mode. A rotating magnetic field is generated when the first electromagnetic coil is powered on, the rotating magnetic field interacts with the permanent magnet, so that a torque is generated, the rotor starts to rotate, the position relation between the magnetic sensor and the rotor is read, and if the distance is judged to be incorrect, the motor is started to rotate. If the position of the rotor is adjusted through the neodymium-iron-boron magnetic ring by adjusting the current magnitude and direction of the electromagnetic ring, direct current is introduced into the electromagnetic ring during adjustment to generate upward or downward electromagnetic force, the neodymium-iron-boron magnetic ring is pushed upwards when the electromagnetic force repels the neodymium-iron-boron magnetic ring, and then the air gap between the rotor and the stator is adjusted. After the air gap is increased, flux leakage is increased, flux linkage is reduced, back electromotive force is reduced, the rotating speed of the motor is increased without flux weakening intervention, and the motor is high in efficiency and safety.

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.

A fluid polishing device for the inner surface of an elongated tube, comprising a working platform (13), fluid processing units, and a magnetically controlled fluid unit. Two fluid processing units are provided, and are symmetrically mounted on the left side and the right side of the working platform (13); the left end and the right end of a workpiece (7) are respectively connected to the fluid processing units on the left side and the right side; the magnetically controlled fluid unit is located below the workpiece (7), and magnetic particles in a polishing solution in the fluid processing units are controlled by means of a magnetic field applied by a magnetic pole (11), so that the magnetic particles form, in a magnetic direction, a flux linkage having a certain yield strength, and are attracted on the inner surface of the workpiece (7) to form a local blocking block, thereby reducing the actual circulation diameter of the polishing solution in a blocked region, thus increasing the flow rate of the polishing solution, and improving the polishing strength. Also provided is a method using the polishing device. The polishing device and method can selectively polish regions of elongated tubes having an extremely fine diameter and an extremely large length-to-diameter ratio.

An offline flux-linkage and moment-of-inertia identification method for a permanent magnet synchronous motor, the method comprising: on the premise that a pole-pair number Pn, a stator resistance Rs, and a stator inductance Ls of a motor are known, tuning PI parameters of a current loop and a speed loop; in a dual closed-loop mode for current and speed, identifying the flux linkage of the motor by using a recursive least squares method with a forgetting factor; in a current closed-loop mode, injecting a low-frequency current signal having progressively increasing amplitude and frequency, and determining a current magnitude required to start the motor and rotate same to a preset rotation speed threshold; and using acceleration / deceleration methods to identify the moment of inertia of the motor, wherein the motor is rotated forward and backward and identification is performed multiple times, and a median value is obtained by ranking to improve identification accuracy. The flux-linkage and moment-of-inertia identification processes are simple, stable, and reliable, the accuracy of identification results is high, one-click parameter identification can be achieved, and the method has a wide range of applications and is applicable to permanent magnet synchronous motors with various parameters.

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.