Quick start-up method of synchronous motor zero-velocity sensor

Abstract

The invention provides a quick start-up method of synchronous motor zero-velocity sensor. The method includes that firstly, a system controller releases motor brake, starts blades to drive a fan to rotate; secondly, the system controller sends out a start-up indication to a motor side convertor after the motor speed reaches the cut-in speed; thirdly, the system controller makes the stator output end of the motor to be in short and detects stator short circuits ia, ib and ic; fourthly, the system controller computes the position angle Thetar and the rotation speed Omegar of the motor rotor according to the detected motor stator short circuits ia, ib and ic; fifthly, the system controller upgrades the relevant variable initial value in the zero-velocity sensor control strategy and starts up the zero-velocity sensor control strategy to realize the start-up of the motor according to the position angle Thetar and the rotation speed Omegar of the motor rotor in the fourth step. The invention accelerates the convergence of the zero-velocity sensor control strategy and realizes quick start-up through initializing the rotation speed and the position of the rotor in the zero-velocity sensor control strategy before the start-up of the motor.

Description

technical field [0001] The invention relates to a speed sensor-less quick start method of a synchronous motor. The method can preliminarily estimate the speed and rotor position information of a permanent magnet synchronous motor whose speed is not zero before starting the permanent magnet synchronous direct drive wind power generating set. Therefore, the starting current of the unit is reduced, the rapidity of the convergence of the speed sensorless control strategy is accelerated, and the quick start is realized, which belongs to the technical field of wind power generation. Background technique [0002] In permanent magnet synchronous direct drive wind turbines, in order to improve the reliability of the transmission system, a speed sensorless control strategy is usually adopted. This is because in wind turbines, the speed sensorless control strategy is very advantageous. First, in megawatt-level permanent magnet synchronous direct-drive wind turbines, under harsh enviro...

AI Technical Summary

Problems solved by technology

First, in megawatt-level permanent magnet synchronous direct-drive wind turbines, under harsh environmental conditions such as temperature, humidity, and vibration, the requirements for speed sensors are high, which increases the maintenance cost of the unit and reduces the reliability.

Moreover, the speed sensor is difficult to install on the outer rotor permanent magnet synchronous generator, which affects its application

Second, there is no zero-speed or low-speed starting problem of the motor, which is the most difficult and unstable part of speed sensorless control

If the voltage applied by the converter is quite different from the amplitude and phase of the back electromotive force of the motor, it will cause an instantaneous overcurrent of the motor, apply a large torque to the motor, cause the wind turbine to vibrate, and affect the mechanical transmission of the unit. adverse effects on the system

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