Strategy Research On Stability Control Strategy Of Vehicle Permanent Magnet Power Generation Battery Charging System

In order to meet the reality of the power series growth of on-board electrical equipment in military and civilian fields,the power generation system is composed of engine,permanent magnet synchronous generator,energy storage battery and power converter.Taking the charging condition of energy storage battery as the research object,this paper carries out theoretical analysis and simulation verification in the aspects of system model establishment,maximum torque current ratio / weak magnetic active disturbance rejection charging stability control,speedless sliding mode observation and so on.In this paper,a 1000 W permanent magnet synchronous generator and a48V50 Ah lead-acid battery are selected to form a permanent magnet power generation battery charging system.The double closed-loop vector control is used to control the motor.Based on the established motor model,an inner and outer loop controller based on active disturbance rejection and a speed sensorless observer based on adaptive sliding mode are designed.The research contents of this paper are summarized as follows :Firstly,based on the established mathematical model of permanent magnet synchronous generator,the control principles of current inner loop,unit power factor,MTPA and flux weakening of double closed-loop vector control of permanent magnet synchronous generator are analyzed in detail.The application scenarios,advantages and disadvantages of different control methods are compared and analyzed.According to the different charging methods of the battery,the constant current charging method is selected to charge the battery,so the DC side current is used as the outer loop control quantity.In order to adapt to the wide speed range of permanent magnet motor,this paper proposes MTPA and flux-weakening integrated charging control.Secondly,considering the factors such as nonlinearity,physical parameter deviation and external disturbance in the mathematical model of the motor,in order to improve the control performance of the system with wide speed and different load states,the thesis proposes an active disturbance rejection control strategy for permanent magnet power generation,and carries out system simulation model establishment and simulation research.The simulation results show that the proposed control strategy can realize the nonlinear constant current charging control of the battery load in a wide speed range.Compared with the traditional proportional integral control,it has smaller overshoot and better control performance.Finally,in order to meet the needs of accurate determination of rotor position in vector control,considering the shortcomings of traditional mechanical speed sensors,such as weak reliability,susceptibility to ambient temperature and operating vibration interference,and inconvenient installation,this paper adopts the method of permanent magnet synchronous generator speed sliding mode observer with S function to overcome the problems of slow response speed and serious chattering in traditional sliding mode observer.The paper analyzes the problem of high frequency interference in the arctangent function to extract the rotor position and the phase delay of the low-pass filter.The normalized phase-locked loop position observer is designed.The analysis proves that the bandwidth of the normalized phase-locked loop position observer is not affected by the speed.It is only related to the parameters of the PI controller,which effectively overcomes the shortcomings of the arctangent function to extract the rotor position.Finally,the simulation results show that it can effectively improve the estimation accuracy of rotor information.