Research On Digital Inverter Power Supply Based On DSP

With the rapid development of modem industry medical,aerospace and other industries,the users have higher requirement on the performance of the power system,the early analog control circuit has simple structure,costs lower,but often has larger output voltage harmonic,waveform has larger distortion,cannot satisfy the requirement of modern industry,high control precision digital control technology,can realize complex control algorithm at the same time,the output load voltage waveform quality is high,with less harmonic content,it is the development trend of the future power system.This paper designs a digital inverter power system.Based on the knowledge of analog inverter,the digital inverter is studied,including the design of hardware circuit and related software.Firstly,the development situation and future trend of inverter power supply are introduced,the research status and existing problems of various control strategies are summarized,and the main research content and chapter arrangement are pointed out.Then,three kinds of sinusoidal pulse width modulation techniques and generating methods of single-phase full-bridge inverter circuit are analyzed theoretically,and a Simulink simulation model is built.Based on the simulation results,unipolar modulation method with less harmonic content and regular sampling generation method are selected.According to the power supply design index,DSPIC30F2010 is taken as the core controller to design the hardware circuit of the system,including the boost circuit,inverter circuit,auxiliary power supply circuit,drive circuit,sampling circuit and protection circuit,etc.The double closed-loop control strategy of voltage outer loop and current inner loop is proposed,and then the inverter power supply system is modeled mathematically.The double closed-loop control strategy is simulated and analyzed in the Simulink simulation environment.The simulation results show that the double closed-loop control strategy has fast response,small steady-state error and good control effect.Finally,the system software was designed,including the main program,A/D sampling subroutine,and DSPIC30F2010 as the control chip,the experimental platform was built,the inverter power system was debugged and the waveform was analyzed,the experimental results showed that the digital inverter power system can meet the expected requirements.