Design Of Cascaded Permanent Magnet Reluctance Generator And Control System Of Cascaded Permanent Magnet Reluctance Generator

According to different excitation modes,the generators of automobile can be classified as electric excitation generator,permanent magnet excitation generator and hybrid excitation generator.Aiming at the problems of high excitation losses and low power density of electrical excitation generator,difficult adjustment of magnetic field and output voltage of permanent magnet generator,complex structure and demagnetization risk of hybrid excitation generator,a CPMRG is proposed,which has the advantages of simple structure,wide effective generating speed,adjustable excitation,high efficiency and low demagnetization risk.The structure and basic principle of the CPMRG are introduced firstly.According to the operation characteristics of the generator,the topology of the power converter,the control method of cascade generation and starting generation without battery are proposed.Basing on the full conduction generation control method of the SRG,a position sensorless generation control strategy of the CPMRG is studied.Secondly,the simulation model of the CPMRG with position sensor is built on the MATLAB/Simulink platform,and the influence of different turn off angles on the output characteristics of the generator is analyzed.Based on the full conduction chopper control method,the simulation model of the CPMRG sensorless control system is complished.The influences of motor speed,load,switch off delay time and battery residual capacity on the output characteristics of the CPMRG are studied.The simulation model of the CPMRG starting power generation is complemented,and the simulation results verify the feasibility of the proposed CPMRG battery free power generation control method.Finally,a prototype test platform of the CPMRG is built,and the hardware and software design of the control system is completed.The main hardware includes DSP controller,drive circuit,main circuit of power converter,voltage/current detection circuit,isolation circuit,filter circuit,rectifier circuit,auxiliary power supply and battery/load.The flow charts of the control system are given,including main program,ADC interrupt service subprogram,etc.The tests of the CPMRG under different speed,different load,different switch off delay time and different battery residual capacity,sudden load increase,sudden load decrease,and battery free starting power generation are completed.The experimental results show that the new cascade generator can generate power efficiently and stably in a wide speed range,and can realize battery free starting power generation at low speed.