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2461 results about "Synchronous motor" patented technology

A synchronous electric motor is an AC motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integral number of AC cycles. Synchronous motors contain multiphase AC electromagnets on the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line current. The rotor with permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field of any AC motor. A synchronous motor is termed doubly fed if it is supplied with independently excited multiphase AC electromagnets on both the rotor and stator.

Method and device for controlling speed of permanent-magnet synchronous motor

The invention discloses a method and a device for controlling speed of a permanent-magnet synchronous motor. The method includes that an active-disturbance-rejection control technology is adopted for a speed ring, speed setting and a speed detection value are taken as input of a first-order active-disturbance-rejection controller, a tracking differentiator reasonably arranges a transition process, an extended state observer observes an actual value of rotating speed of the motor, estimates total disturbance of a system and acquires output of the speed ring through a nonlinear state error feedback control ratio, a load torque observer is designed through detection values of a current and the speed, and observed load torque through output of a feedforward controller and the active-disturbance-rejection controller is taken as reference input of a quadrature-axis current. The method carries forward characteristics of overshoot freeness, high disturbance rejection capacity, good robustness and the like of the permanent-magnet synchronous motor in speed control in the active-disturbance-rejection control technology, and compensation is performed on the problem of load disturbance, so that the problem of fluctuation of the rotating speed under the circumstance of load disturbance is improved.
Owner:SHANDONG UNIV

Method for detecting initial position of magnetic pole of rotor of built-in permanent magnetic synchronous motor

The invention provides a method for detecting the initial position of a magnetic pole of a rotor of a built-in permanent magnetic synchronous motor, belongs to the field of motor control, and solves the problems of over-complicated processing, easy occurrence of polarity misjudging, poor practicality and the like existing in the conventional method based on high-frequency signal injection for detecting the initial position of the rotor. The method comprises the following steps: constantly maintaining the stationary state of the rotor; injecting a rotating high-frequency voltage signal into a stator winding; detecting three-phase stator current and converting the three-phase stator current into two-phase static coordinates; acquiring an error signal capable of reflecting position information of the magnetic pole of the rotor through signal processing; adjusting the error signal by using a PI tracker so as to acquire an initial judging value of the position of the magnetic pole of the rotor; and injecting two impulse voltage vectors in opposite directions into the stator winding, comparing values of direct axis current components by detecting the three phase current and converting the rotating coordinates so as to determine the polarity of the magnetic pole, and finally acquiring the initial position angle of the magnetic pole of the rotor of the built-in permanent magnetic synchronous motor.
Owner:哈尔滨同为电气股份有限公司 +1

Speed sensor-less method for estimating rotor angle and revolving speed of permanent-magnet synchronous motor

The invention relates to the technical field of electric transmission and control, in particular to a speed sensor-less method for estimating the rotor angle and the revolving speed of a permanent-magnet synchronous motor. The method comprises the following steps: a. obtaining the rotor flux linkage amplitude Psi<r> of a permanent-magnet synchronous motor; b. transforming a stator voltage fundamental component to be under an alpha beta coordinate system to obtain u<alpha> and u<beta>; c. transforming the stator current fundamental component to be under the alpha beta coordinate system to obtain i<alpha> and i<beta>; d. carrying out highpass filtering on stator current i<alpha> and i<beta> under the alpha beta coordinate system, and obtaining the differential estimation value sum of the stator current; e. obtaining a stator counter electromotive force estimation value; f. obtaining a rotor revolving speed calculation value omega<rC> and a rotor angle calculation value theta<rC>; g. carrying out lowpass filtering on the rotor revolving speed calculation value omega<rC> to obtain a rotor revolving speed estimation value; h. obtaining the estimation value of a rotor angle starting value; and i. obtaining a rotor angle estimation value. The method has the advantages that only forward calculation, instead of a feedback channel, exists in the method for estimating the rotor angle and revolving speed, and except filter delaying, no dynamic regulation process exists.
Owner:DONGFANG ELECTRIC CORP LTD

Inductance parameter identification method of synchronous motor and implementation system thereof

An inductance parameter identification method of a synchronous motor and an implementation system thereof are provided. The method comprises: applying a three-phase balance high frequency voltage or current signal to the synchronous motor; sampling a feedback high frequency current or voltage of the synchronous motor; extracting positive sequence and negative sequence component amplitude of the feedback high frequency current or voltage which has the same frequency of the injecting voltage or current; and calculating to get d-axis inductance Ld and q-axis inductance Lq of the synchronous motor. Identification of the d-axis inductance and q-axis inductance of the synchronous motor can be implemented more accurately on a general inverter on the basis of non-increase of hardware cost. The method and system have the following advantages of implementing easily, not high demand for the motor feedback current sampling accuracy, and controlling easily for the frequency and amplitude of the high frequency voltage signal injected into the motor, and identifying to get the d-axis inductance and q-axis inductance of the motor directly no matter the motor shaft is in a free state, or in a hold tight stage, which do not affect accuracy of identification.
Owner:SHENZHEN INVT ELECTRIC

Brushless doubly-fed motor excitation control system and control method using same

The invention relates to a brushless doubly-fed motor excitation control system, which is characterized by comprising a PWM (Pulse-Width Modulation) rectifying unit, a first current sensor, a smoothing reactor, a contactor, an excitation controller and an inverter unit, an operation and display unit, an energy storage device, a BOOST reactor, a soft start circuit, a first voltage detection circuit and a second voltage detection circuit. The brushless doubly-fed motor excitation control system can always keep a speed-variable load-variable constant-frequency and constant-voltage power generation state when a brushless doubly-fed motor is at an electric operating state, the rotating speed of a brushless rotor rapidly changes and the load condition is within a larger range; and when the brushless doubly-fed motor is at the electric operating state, the brushless doubly-fed motor excitation control system can finish rapid adjustment of the rotating speed of the brushless rotor by excitation control and realizes multiple electric operating modes, such as synchronous operating, asynchronous operating and doubly-fed speed adjustment. When the load condition changes in a larger range, the brushless doubly-fed motor excitation control system can always keep the hard mechanical property of a synchronous motor. The invention also comprises the control method using the brushless doubly-fed motor excitation control system.
Owner:BEIJING SWORD ELECTRIC IND
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