Research On Permanent Magnet Synchronous Motor Sensorless Control System Of DC110V Power Supply

In this paper,the sensorless control system for permanent magnet synchronous motor(PMSM)is studied.PMSM has the advantages of small loss,high efficiency and small size.Meanwhile,the SVPWM modulation strategy of three-phase inverter and three low-cost resistance sampling schemes are analyzed and compared in detail.On the basis of theoretical analysis,relevant hardware is designed to ensure the safe and reliable operation of subway emergency ventilation system powered by 110V battery.The main research work of this paper includes the following parts:Firstly,the mathematical model of the interior permanent magnet synchronous motor is derived by means of coordinate transformation.On this basis,this paper studies the influence of several different methods of stator flux observer on the observation results.For each method,the relevant formula was derived to rigorously analyze their characteristics,and the accurate rotor position and speed information was obtained by the phase-locked loop module.At the same time,the simulation was carried out in Matlab/Simulink software to analyze and compare the observation errors.Then,the principle of Seven-segment SVPWM modulation method and five-segment DSVPWMMIN modulation method is analyzed.The difference between the two methods and the loss of the inverter caused by them are compared.In addition,the influence of the two methods on the harmonic content of the phase current of the motor is studied.And the simulation analysis in Matlab/Simulink software.At the same time,the characteristics of three low cost resistance sampling methods are studied.In order to solve the problem of insufficient sampling time for single resistance of dc bus,the method of pulse phase shifting is used to improve the sampling result.The results of single resistance sampling and double resistance sampling of lower bridge arm are compared in the simulation to provide the basis for hardware design.Finally,the hardware circuit design is carried out on the basis of theoretical analysis,including dc input circuit,IPM inverter circuit,DC/DC power supply circuit,over-temperature and over-current and under-voltage protection circuit,current and voltage sampling circuit,etc.,and the characteristics of each circuit and the calculation of relevant parameters are studied and analyzed in detail.At the same time,the software system is designed based on TMS320F28035 chip.According to the circuit design,the experimental platform was set up,and relevant experiments were completed on the experimental platform to verify the above theories and simulation results.The experimental results showed that the control system could operate safely and reliably with good control performance and low noise of the ventilation motor,realizing the project requirements.