Starting detection device and starting method for permanent magnetic synchronous motor speed sensorless

Abstract

The invention discloses a starting detection device for a permanent magnetic synchronous motor speed sensorless, which comprises a three-phase rectification circuit and a permanent magnetic synchronous motor, and the permanent magnetic synchronous motor is connected with the three-phase rectification circuit via three paths thereof, i.e. U, V and W; the starting detection device comprises a main control circuit, a man-machine module and a counter-electromotive force detection circuit; the input end of the counter-electromotive force detection circuit is connected with the three paths of the permanent magnetic synchronous motor, and the output end of the counter-electromotive force detection circuit is connected with the input end of the main control circuit; the current sampling end of the main control circuit is also connected with the permanent magnetic synchronous motor; the output end of the main control circuit is connected with the three-phase rectification circuit; the main control circuit is also connected with the man-machine module; and the three-phase rectifier circuit is a controllable three-phase rectifier circuit. The invention also provides a staring method for the permanent magnetic synchronous motor speed sensorless. The device and the method provided by the invention can acquire motor rotation speed, rotor position, the amplitude value and the phase of a counter-electromotive force, and the like.

Description

technical field [0001] The invention relates to the technical field of wind power generation, especially the application in small and medium-power wind power generators, and specifically relates to a start-up detection device and a start-up method for a speed sensorless permanent magnet synchronous motor in a wind power generator set. Background technique [0002] A speed sensorless start-up detection device and a start-up method of a permanent magnet synchronous motor are the start-up detection device and method of a permanent magnet synchronous motor without a speed sensor. In the wind power generation system, the power conversion part includes a three-phase rectification circuit and a permanent magnet synchronous motor, and the permanent magnet synchronous motor and the three-phase rectification circuit are connected through U, V and W. The three-phase rectification circuit is composed of six diodes. Because the diode is uncontrolled rectification, that is, the on-off of...

AI Technical Summary

Problems solved by technology

Since the diode is uncontrolled rectification, that is, the on-off of the diode is uncontrolled, so the characteristics of this uncontrolled rectification determine the non-sinusoidalization of the motor current, and the power factor is low, so that the utilization rate of the motor capacity is low.

Simultaneously, the permanent magnet synchronous motor has a certain motor speed when starting, and at this moment, the counter electromotive force of the motor is not zero, and before the wind turbine is started, the three-phase rectifier circuit of the prior art cannot obtain the rotational speed of the motor (that is, the counter electromotive force is not zero). The frequency of the electromotive force), the rotor position (that is, the electrical angle of the back electromotive force), the phase sequence (the phase sequence state of the motor connection), and the magnitude of the back electromotive force. A large torque is generated, causing the wind turbine to vibrate, thus causing damage to the mechanical transmission system and power devices of the unit

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