Method for detecting pre-operation state of motor

Abstract

The invention relates to the technical field of PMSM (permanent magnet synchronous motor) position-sensorless control, especially a method for detecting the pre-operation state of a motor. The methodcomprises the steps: enabling a controller to obtain a three-phase current through a current sensor, converting the current of the motor into a two-phase current omega<-30 in a two-phase stationary coordinate system through Clark transformation, converting the current omega<-30 in the two-phase stationary coordinate system into currents Id_fbk and Iq_fbk in a two-phase rotating coordinate system through a Park converter; adjusting a D-axis current given quantity Id_Ref and a Q-axis current given quantity Iq_Ref through a PI adjuster; converting the Ud and Uq in the two-phase rotating coordinate system into a voltage Ualpha and Ubeta in the two-phase stationary coordinate system through inverted Park conversion; outputting six PWM signals through SVPWM according to a space voltage vector pulse width modulation method, and controlling the inverter; and enabling the inverter to convert a direct current into an alternating current according to the PWM signals outputted through SVPWM. The method provided by the invention is low in cost, is reliable in performance, is simple in implementation, and does not generate a big current in a detection process.

Description

technical field [0001] The invention relates to the technical field of motor detection equipment, in particular to a method for detecting the state of a motor before running. Background technique [0002] At present, brushless DC motors and permanent magnet synchronous motors widely use position sensorless algorithms to detect rotor positions. Generally speaking, the normal starting process includes positioning, open-loop operation, and closed-loop operation without a position sensor to generate a position signal. Before the motor starts to run, there may be three states of the motor, which are static, forward rotation, and reverse rotation. When the motor is stationary, the motor starts in the normal way; when the motor rotates in the forward direction, the positioning process can be omitted and directly enters the open-loop operation stage; After coming to a standstill, start in the normal way. Therefore, it is very important to detect the state of the motor before star...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the deficiency that the existing motor cannot determine the initial position of the motor rotor before starting, the present invention provides a method for detecting the state of the motor before running, including the controller obtaining the three-phase current through the current sensor, and the Clark transform transforming the motor The three-phase phase current is converted into the two-phase current of the two-phase static coordinate system , and then convert the two-phase current in the two-phase static coordinate system through the Park converter It is converted into the current Id_fbk and Iq_fbk in the two-phase rotating coordinate system, the D-axis current given amount Id_Ref and the Q-axis current given amount Iq_Ref are adjusted through the PI regulator, and the inverse Park transformation is used to convert Ud and Uq under the two-phase rotating coordinate system To the voltages Ualpha and Ubeta in the two-phase static coordinate system, SVPWM modulation outputs 6 PWM signals to control the inverter according to the method of space voltage vector pulse width modulation, and the inverter converts direct current into alternating current according to the PWM signal output by SVPWM

Images