Research On Sensorless Hybrid Vector Control System Of Synchronous Reluctance Motor

As the power source of the modern ship,the reliability and low vibration of the motor have an important effect on the concealment and safety of the ship.According to the investigation,the motors used in modern ships are mainly asynchronous motors and permanent magnet synchronous motors.Although the asynchronous motors have mature manufacturing technology and low manufacturing cost,they still have problems such as low efficiency,high loss and large vibration during driving.Although permanent magnet synchronous motor has high efficiency and low loss,its rotor is a rare earth permanent magnet.When applied in some high temperature environment,permanent magnet materials may have demagnetization phenomenon,and the cost is high.Synchronous reluctance motor has low manufacturing cost,working efficiency between asynchronous motor and permanent magnet synchronous motor and closer to permanent magnet synchronous motor because of its rotor without permanent magnet,and simple control structure,small noise and vibration,which can better meet the requirements of low vibration and reliability of motor ships.However,the use of traditional physical sensors will increase the cost and volume of the motor,and the accuracy of the control will also be affected by the working environment,so the sensorless control technology is needed to estimate the rotor position and speed information.At present,the main problem of sensorless control technology is that it is impossible to use a single control strategy to estimate the rotor position of the motor in the full speed domain.In this regard,this paper takes synchronous reluctance motor as the object,and studies sensorless control algorithm applicable to zero low speed and medium high speed and how to achieve smooth switching between the two algorithms.The main research content is as follows:Firstly,this paper describes the operation principle of synchronous reluctance motor,and introduces the mathematical model of synchronous reluctance motor in three coordinate systems: three-phase static coordinate system,α-β static coordinate system and d-q rotating coordinate system.Secondly,the pulse vibration high-frequency current injection method is used to estimate the rotor position and speed information in the zero low speed domain.This method can obtain the rotor position error signal by injecting high-frequency current signals into the direct axis of the estimated synchronous rotating coordinate system,and then detecting the high-frequency voltage response of the intersection axis,so as to achieve the zero low speed rotor position estimation.In the middle and high speed domain,the model reference adaptive method is used to estimate the rotor position information,the synchronous reluctance motor is used as the reference model,the adjustable model of the system is derived,and then the popov superstability theory is used to derive the adaptive law of the system,and then the adjustable model is adjusted to make the adjustable model approximate to the reference model,so as to realize the rotor position estimation of the middle and high speed.Then,in order to ensure the smooth transition between the two sensorless control algorithms in the switching interval,this paper proposes an improved weighting algorithm based on the traditional weighting algorithm,which uses sinusoidal saturation function instead of the traditional linear switching function to fuse the position error signals obtained by the two algorithms.In order to verify the effectiveness of the proposed control strategy,a simulation model was built in Simulink,and the start-up and steady-state performance and anti-load disturbance performance were tested and analyzed.Finally,in order to verify the effectiveness and feasibility of the control system,an experimental platform consisting of a host computer,a speed and torque measuring instrument,a magnetic clutch,a driver and a synchronous reluctance motor was built.Based on CCS software,the code of sensorless hybrid vector control system of synchronous reluctance motor is written and debugged.Finally,the motor start-up and steady-state performance as well as load disturbance resistance performance are tested on the experimental platform.The experimental results verify the applicability and correctness of the sensorless hybrid vector control system of synchronous reluctance motor proposed in this paper.