Research On Sensorless Control Strategy Of Switched Reluctance Motor

Switched Reluctance Motor(SRM)has been widely used in many fields because of its simple structure,large starting torque,small starting current and strong fault tolerance.In order to realize high performance speed control of SRM,the position information of rotor must be acquired in real time.The traditional rotor position detection generally uses position sensor,but the introduction of position sensor not only increases the cost and processing complexity of speed control system,but also reduces the reliability of speed control system in some harsh environments.Therefore,it is significant to carry out sensorless research for switched reluctance motor.Two sensorless control methods of switched reluctance motor(SRM)are proposed to solve the problem of inaccurate rotor position estimation based on the inductance intersection point between on-phase and non-on-phase of SRM due to magnetic circuit saturation.Finally,the feasibility of the above method is verified by simulation and experiment.The main contents of the paper include:1?This paper briefly introduces the basic characteristics of SRM,expounds the research work and existing problems on position detection of SRM at home and abroad,and introduces the overall framework and content of this paper.2?This paper introduces the basic composition of SRM sensorless control system,and briefly describes its basic working principle,mathematical model and basic methods and ideas of adopting control strategy.3?Aiming at the problem that the position of the intersection point between the on-phase inductor and the non-on-phase inductor will be offset with the increase of the on-phase current when the on-phase magnetic circuit is saturated in the position sensorless control of SRM by sampling magnetic circuit/current method,which makes the rotor position estimation inaccurate.A sensorless control method of Switched Reluctance Motor Based on phase inductance intersection position and angle compensation is proposed.Functional relationship between saturated current of on-phase and angle deviation of on-phase and non-on-phase inductance intersection relative to reference position of switched-magnetic generator is constructed.According to the function relation and the saturated current of on-phase detected in real time,the corresponding phase inductance intersection point is modified to obtain the accurate position angle of phase inductance intersection point.4?In order to simplify the calculation and improve the estimation accuracy,a sensorless control method of Switched Reluctance Motor Based on line inductance feature point location is proposed.Firstly,the basic concepts of line inductance and its characteristic points are put forward,and the functional relationship between line inductance and rotor position angle is analyzed.The specific realization method of estimating the average speed of motor rotor in this region and the position of the next corresponding region is studied according to the position angle and time of the corresponding region of two adjacent line inductance characteristic points.5?A SRM sensorless experimental device was developed with TMS320F28335 as the control core and IHW30N120R2 as the power switch of the main circuit.