Initial Position Detection Of Permanent Magnet Synchronous Motor Rotor Based On High Frequency Voltage Injection Method

Permanent magnet synchronous motor has the advantages of simple structure,low loss,high power factor and high efficiency,so it has been widely used in the fields of industrial robots,aerospace and other fields.In traditional speed regulating system,the encoder or speed sensor is required to measure the position and speed parameters,but it increases the cost of the system and reduces the reliability of the system.The sensorless control system of permanent magnet synchronous motor can effectively solve these problems,but if the rotor initial position of the permanent magnet synchronous motor is not accurate in the sensorless sensor control system,it will affect the smooth starting and running performance of the motor.Therefore,in order to realize the high performance control of the permanent magnet synchronous motor,the initial position of the rotor needs to be accurately detected.In order to accurately detect the initial position of rotor,this paper proposes an initial position detection method based on high frequency voltage signal injection.This method is suitable for the interior permanent magnet synchronous motor,which can detect the initial position of motor rotor simply and accurately.The dependency of motor parameter with the method is small,and when calculating rotor position,the formula does not contain high frequency voltage amplitude and angular frequency in traditional method that affecting the angle detection accuracy,getting accurate initial rotor position to ensure that the motor starts smoothly.Due to the high frequency signal detecting the rotor angle need low-pass filter for filtering,and filtering problems is the phase delay.So by current harmonic analysis,angle error compensation strategy is designed to reduce the delay problems,to gain accurate angle information and reduce the angle error.Through the angle of error analysis,the influence of high frequency voltage amplitude and angular frequency on position detection is not negligible.Through the formula that does not contain high-frequency voltage amplitude and angular frequency and through the angle compensation strategy,it can get accurate rotor position information.Due to salient pole rotor symmetry,the actual d axis direction is still unable to be determined,so it is needed to use magnetic saturation effect which causes the inductance changes to judgment the polarity of the rotor.This paper verifies the feasibility of this method by simulation,and can detect the initial position of rotor accurately.Finally,the experimental platform is built,and the experiment program is written,and the rotor initial position detection method is verified.The experimental results show that the initial position angle of rotor calculated with the obtained current response can improve the accuracy of the detection angle,and the average detection error is small.