Research Of PID And Repetitive Multiple Control Digital Inverter Based On DSP

Ideal output voltage of inverter power supply not only requires good steady-state performance,but also has a faster dynamic response.While a single control strategy is very difficult to meet the requirements of these two aspects,so all kinds of advanced digital control strategies complement each other,mutual penetration compound controller,is a kind of trend.In this paper,we analyze the single polarity SPWM inverter power supply,the first digital process is mainly studied the impact on the inverter power supply system.Start with analyzing the P control of and research on PI control,analog control and digital control system stability analysis concluded that to provide some useful guidance for analysis and design of inverter.Then,analyzed the digital PID control and repetitive control respectively the effects of two kinds of control strategies,digital PID control has good dynamic performance,but its steady-state performance is not ideal,especially in nonlinear load when the output voltage waveform of total harmonic distortion is larger;Repetitive control on the contrary,it has good steady-state performance,but because of the existence of the life cycle delay,output control instruction is not immediately,but lags behind a reference cycle to output,make its dynamic performance is poorer.Therefore,this article studied and analyzed the combining PI control and improvement of repetitive control of compound control strategy.Control system was established based on MATLAB,a simulation model of the impedance under load,the harmonic distortion of composite control system of THD value by 1.11% of PI control increased to 0.49%,nonlinear loads,THD value by 2.15% of PI control to 0.69%.The simulation results proved that application of the composite control method of inverter power supply has better steady-state and dynamic performance.Finally,details the hardware circuit and software program of the specific design process,the experimental waveforms are given to verify the correctness and effectiveness of the compound control method theory.