159 results about "Permanent magnet synchronous machine" patented technology

A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

A permanent magnet synchronous machine with improved torque and power characteristics. A circumferential-oriented rotor assembly is provided with alternating permanent magnets and magnetic pole pieces. In order to reduce the amount of leakage flux in the rotor and increase the effective length of the permanent magnet, a trapezoidal or otherwise tapered permanent magnet structure is used. By alternating trapezoidal permanent magnet, and magnetic pole pieces, a higher intensity magnetic field is created in the air gap utilizing the same radial space in the motor without altering the weight or volume of the motor compared to conventional machines.

A position observer for control-based torque ripple mitigation in permanent magnet synchronous machines (PMSMs). Rotor position is determined using data from two sources: a piezoelectric sensor for initial position and low-speed detection, and a single Hall-effect sensor for high-speed detection.

A method and apparatus for determining electrical parameters for commissioning a sensor-less permanent magnet synchronous machine uses knowledge of the rotor position to apply balanced pulses along the rotor magnet axis and perpendicular to the rotor magnet axis allowing measurement of q- and d-inductance at multiple current levels without substantial rotor movement.

A permanent-magnet synchronous machine includes a stator that has slots and a rotor that has permanent magnets which form magnet poles. The permanent magnets are shell magnets having two curved surfaces. Each shell magnet covers a predetermined part of a magnet pole. The external radius of the shell magnets is less than 0.6 times the radius of the stator bore. Each shell magnet has a quasi-radial magnetic preferred direction that is directed substantially perpendicular to its outer surface.

A motor assembly of multiple motors for use in driving a shared downhole load within a well. In particular, the assembly may employ substantially constant adjustable speed motors. These may include permanent magnet synchronous machine motors. The motors may be configured to operate at given speeds that may be downwardly adjusted depending on the amount of torque output independently exhibited by the individual motors. In this manner, a significant divergence in torque output between the motors may be avoided so as to ensure substantial load sharing between all of the motors of the assembly.

A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine the method comprising the steps of calculating first stator flux vector estimate ({circumflex over (ψ)}_d,i+j{circumflex over (ψ)}_q,i) using the flux model and measured stator currents, calculating second stator flux vector estimate ({circumflex over (ψ)}_d,u+j{circumflex over (ψ)}_q,u) using the voltage model and measured stator voltages, comparing the directions of the first and second flux vectors to achieve a first error signal (F_ε), using speed adaptation to achieve estimates for the rotor angular speed ({circumflex over (ω)}_m) and angular position ({circumflex over (θ)}_m) from the first error signal (F_ε), injecting a known voltage signal (u_c) to the stator voltage, detecting a current signal (i_qc) from the stator current to form a second error (ε) signal, which is dependent on the estimation error of the rotor position, augmenting the voltage model by the second error signal (ε) to keep the first and second flux vector estimates aligned and so to correct the rotor angular speed ({circumflex over (ω)}_m) and angular position ({circumflex over (θ)}_m) estimates.

A permanent-magnet synchronous machine for suppressing harmonics includes a stator and a rotor with permanent magnets. Each permanent magnet represents a magnetic pole and is, when viewed in the circumferential direction of the rotor, shaped as a parallelogram or an arrow. The pole coverage is less than one. The permanent magnets are staggered at a staggering angle, wherein the permanent magnets of one pole are arranged in the axial direction with an increasing offset of a circumferential angle in relation to a first permanent magnet of this pole. Each permanent magnet is skewed at a skew angle defined by a circumferential angle of a projection of a tip portion of the parallelogram or arrow. The optimal skew and staggering angles are calculated from the design parameters for the stator and the number of pole pairs and the number of poles in the axial direction of the rotor.

A method of controlling an AC machine that includes a stator and a rotor. The method includes observing a stability parameter that is indicative of the stability of the AC machine and dependent on a current state of the AC machine; and controlling the AC machine based on the observed stability parameter so as to promote stable operation of the AC machine. The method may include controlling the AC machine to operate as a motor or as a generator. The AC machine may be a permanent magnet synchronous machine. A controller suitable for performing the method is also disclosed.

An enhanced torque ripple mitigation algorithm for permanent magnet synchronous machines (PMSMs), the algorithm including compensation for sensor delay.

The invention discloses a model prediction-based torque control method for a flux-switching permanent magnet synchronous machine. The model prediction-based torque control method comprises the following steps: combining the switch tube states of a motor inverter to obtain eight sets of switch vector signals; at the current moment K, under each set of vector signals of the inverter switch, predicting a p-phase winding current (please see the specification for the formula) at the next moment K+1 to obtain current prediction values (please see the specification for the formula) of a shaft d and a shaft q; predicting motor torque (please see the specification for the formula) and motor flux linkage (please see the specification for the formula) at the next moment k+1; calculating a cost function (please see the specification for the formula) to obtain the vector signal of the inverter switch when the cost function is the smallest; defining m (please see the specification for the formula), controlling the effective acting time of the vector signal of the inverter switch when the cost function is the smallest in a single sampling period according to a value of m to complete torque control of the flux-switching permanent magnet synchronous machine. The method can accurately control change of the vectors of the inverter switch, enables the motor torque fluctuation and the flux linkage fluctuation to be the smallest, and the effective acting time of the inverter switch is adjusted through the duty ratio, so that the on and off frequency of the inverter can be effectively reduced.

The invention discloses a printed alternating-current motor, and is suitable for being used in the field of industrial micro-type equipment. The printed alternating-current motor comprises a stator iron core, insulating paper, a stator printed board, a rotor, a bearing, a rotating shaft and the like, wherein the rotor can be a permanent magnet synchronous machine rotor and can also be an asynchronous machine rotor. The permanent magnet synchronous machine rotor is arranged by attaching a permanent magnet onto a rotor iron core, and the asynchronous machine rotor is arranged by fixing the stator printed board onto the rotor iron core. The stator printed board and a rotor printed board are printed circuit boards respectively, wherein the multi-layer stator printed board adopts a wavy winding, the rotor printed board adopts a cage winding, and the rotor iron core and the stator iron core are formed by laminating silicon steel sheets respectively. Due to the fact that the printed alternating-current motor stator adopts the printed board, the volume of the motor is greatly reduced, so that the motor is lighter and thinner, the trouble of ordinary motor winding is reduced, and the printed alternating-current motor is convenient for large-scale production. Moreover, a Hall sensor is integrated on the stator printed board of the printed alternating-current motor, so that the printed alternating-current motor is convenient to use together with a controller.

A mixed excitation double-convex pole permanent magnet synchronous motor. It is composed of magnet double-convex pole motor and the permanent magnet synchronous motor. The stators and the rotors of the two motors are independent, and share the shell and the revolving axis. The teeth of the stator of the double-convex pole motor has armature winding and excitation winding, the rotor does not have winding. The teeth of the stator of the permanent magnet synchronous motor have the armature winding. The armature windings of the two motors are in series. Adjust the amount and direction of the excitation current, the phase electric force can be modulated. Change the length proportion along the axes direction of the excitation double-convex pole motor and the permanent magnet synchronous motor, the breadth value of electric force will change correspondingly. It can be used as three-phase motor and multi-phase motor, AC motor or DC motor.

A permanent magnet synchronous machine (PMSM) includes a stator and rotor powered by an inverter. A device to control the PMSM includes a sensor to sample a measurement θ_m of the position of the rotor, a control unit to control an operating point of the PMSM according to the position of the rotor and settings, and an estimation unit to determine an estimate {circumflex over (θ)} of the rotor position. The device also includes a malfunction detector to detect a malfunction of the sensor and a switch to connect the control unit to the sensor so that the control unit receives the measured position θ_m of the rotor while the malfunction detector does not indicate any sensor malfunction, and otherwise to connect the control unit to the estimation unit so that the control unit receives the estimated position {circumflex over (θ)} of the rotor when the malfunction detector indicates a sensor malfunction.