Design Of Vehicle Sine Wave Inverter Based On Digital Control Technology

With the continuous development of automotive industry and improving level of consumption,people have also put forward higher requirements for vehicle power supply.Nowadays the vehicle inverter power supply has gradually become the essentials in cars.Therefore,it is of great significance to study a cost-effective,high efficiency and perfect function of the vehicle inverter power supply.For power supply performance requirements of the vehicle inverter,this paper uses the advanced control strategy is used to design a digital vehicle inverter based on DSP processor.In this paper,the basic structure and working principle of the inverter are analyzed firstly,and then the modulation method are simulated and analyzed,the unipolar frequency doubling SPWM modulation technology is determined.In the design of inverter control system,the structure of the inverter power supply is analyzed and state space mathematical model is established in this paper,then the problem of poor stability and insufficient robustness of the traditional double-loop PID control method is discussed.On this situation,a multi closed loop controller design method,based on the ratio of current control and prediction model voltage control,is presented in this paper.By inductance inner ring and capacitance middle loop of current controller,the car inverter is designed and modified,and then voltage controller is designed for the augmented controlled object with capacitive current predictive.Finally three kinds of control schemes are simulated using the MATLAB software.Compared with the output instantaneous waveform,we can see that the proposed by the model predictive multi loop control has better robustness and anti-interference ability.The hardware circuit and software of inverter power source are designed respectively.Mainly including the main circuit of inverter power supply and the DSP control circuit.Power supply adopts two level topology structure,the first stage is by SG3525 as the main control chip push-pull booster,after stage to TMS320F28335 control system for full bridge inverter.And also the main circuits the system are analyzed,such as double transformer circuit,filter circuit,drive circuit,sampling circuit and protection circuit.DSP control function includes control algorithm,signal sampling,SPWM wave generation and fault treatment,etc.Finally,the experimental prototype is made,the transient waveform is collected and the efficiency of the prototype is measured and the stability of the output under load fluctuation.The experimental results show that the system has good output waveform and high conversion efficiency,which can meet the requirements of vehicle equipment for power quality.