Research On Sensorless Control Of Switched Reluctance Motor Considering The Effect Of Inductance Saturation

Switched reluctance motor(SRM)not only has simple and solid characteristics of AC system motor,but also has the advantage of good debugging performance of DC system motor,simple and cheap control circuit,as well as high operating efficiency and fault-tolerant performance.Widely used in energy mining equipment,new energy vehicles,machine locomotives,fans pumps and other fields.However,in most application fields,the motor position information is obtained by using position sensor,which limits the application of SRM in extreme environments such as high dust and high temperature.At the same time,with the use of position sensor,the cost and complexity of motor control system will increase.Therefore,it is of great significance to study more accurate SRM sensorless technology with practical value.This paper first describes the research status of SRM,introduces its basic structure and working principle.The flux saturation curve of a three-phase 12/8-pole SRM is measured by indirect locked rotor test.According to the measured flux characteristic curve,a non-linear motor model is built in Matlab/Simulink.Then,in the exploration of more precise sensorless technology,it is found that in the traditional inductance curve intersection and based on inductance linear model method,inductance saturation influence is one of the main factors causing the larger position error.In order to solve this problem,this paper establishes the functional relationship between load torque and inductance saturation,and proposes corresponding improvement strategies based on the estimation principles of two position estimation methods.In the inductance curve intersection method,the offset of intersection error caused by inductance saturation is compensated;In the inductance linear model method,the position estimation error is corrected by changing the fitting function coefficient of the region.The two improved position estimation methods are simulated in the MATLAB/Simulink software,and results show that the compensation and coefficient modified methods both reduce the influence of inductance saturation on position estimation,and the position estimation is more accurate.Finally,a SRM speed control platform is built with SRM of 15kw as the main part and DSP of TMS320F2812 as the control core.The two sensorless algorithms considering the influence of inductance saturation proposed in this paper are test in the speed control system.The experimental results show that the two improved strategies are more accurate to estimate the rotor position information and have good practical value.