Research On The Semi-physical Simulator Of Switched Reluctance Machine System And Its Application

Switched reluctance(SR)machine has a wide development prospect for its advantages of simple structure,high reliability,wide speed range,excellent fault-tolerant performance,and high efficiency.However,due to the double salient pole structure and special excitation mode,the further research on the nonlinear modeling,power converter,fault diagnosis,torque control,and sensorless position control is necessary,which depends on the exact and practical simulaton model of SR machine system.Considering that SR machine system and meminductive system are both the time-variation nonlinear dynamic system,they are very similar.Based on the theoretical and emulator circuit of meminductive system,this dissertation focuses on the semi-physcial simulator of SR machine system and its application.The generic meminductive characteristics of single-phase SR generator and multiphase SR motor are analyzed and verified,respectively.The indicative fingerprints of meminductive system are summarized by the PSPICE simulation analysis.Based on the Matlab/Simulink simulation model of single-phase SR generator,the numerical analysis results indicate that the current and flux linkage waveforms pass through the origin simultaneously,the pinched hysteresis loop(PHL)exists in the current-flux linkage plane,and the area enclosed by PHL is dependent on the amplitude of the current and flux linkage.Moreover,the simulation and experiment results of four-phase 8/6 SR motor manifest the unique memory ability of phase inductance,PHL characteristics,and the frequency dependency characteristic of PHL.Two circuits with floating terminals capable of emulating the behavior of meminductor are set forth,which are composed of only off-the-shelf circuit devices.One of the developed circuits is dependent on a memristor emulator and a mutator which possesses the ability that the nonlinear current–voltage relationship of the memristor can be transformed into the current–flux relationship of the meminductor,while the other is carried out by using a multiplier AD633 and other circuit components without memristor.Therotical analysis,simulation results,and experimental results provide us with the conclusive evidences for the correctness and effectiveness of these two proposed meminductor emulators.Compared with the first one,the second one has simpler topology and it is easier to implement.Hence,the second meminductor emulator is combined with digital signal processing technology to mimic the characteristics of SR machine winding.The experiment results manifest that this mix-signal circuit can emulate the dynamic electrical behavior of four-phase 8/6 SR machine at different speeds,different turn-on angles and turn-off angles as well as under the condition of current chopped control.On the basis of the proposed emulator circuit of SR machine winding,the semi-physical simulator for four-phase 8/6 SR machine system is designed,which consists of analog circuit,digital signal processor(DSP),digital-to-analog converter(DAC),and analog-to-digital converter(ADC).Then,the experiment platform of semi-physical simulator is constructed and the experiment verification is given.The proposed SR machine winding emulator circuit and prototype can be operated simultaneously.By applying this method,the accuracy of two nonlinear inductance analytic models are verified online,where the model?contains the fourier series and polynomials,while the model ? is based on the exponential function.Experiment results indicate that the model?is more accurate.Moreover,the universality of the proposed winding emulator is certified by using it to emulate the electrical behavior of three-phase 12/8 SR machine winding.The proposed semi-physical simulator of SR machine system is used to study the automated resistance correction based sensorless position control method.The phase resistance of SR machine is not fixed and varies with temperature,and thus can be regarded as a nonlinear resistor.Based on the second proposed meinductor emulator,an improved flux linkage measurement circuit with the function of automated resistance correction is proposed and then applied in the sensorless position control of SR machine.The semi-physical simulator of SR machine is connected with the improved flux linkage measurement circuit,which is useful to the design of circuit parameters.Finally,the proposed sensorless position control method is applied in the prototype system,the experiment results indicate that the effect of resistance error on the flux linkage measurement and position estimation cannot be ignored,and the proposed flux linkage measurement circuit can handle this issue.Compared with the traditional position estimation method which ignores the resistance variation,the developed sensorless control method can improve the accuracy of the position estimation.