| The existing power electronics experimental devices mainly use analog control mode or special analog integrated control chip way to achieve,there are large size,complex structure,slow dynamic response,high manufacturing costs,universal is not strong and other shortcomings,and can only do some demonstration or verification experiments,limiting the training of students’ hands-on ability and innovation ability.The use of digital control technology,its hardware circuit structure is simple,flexible control,easy to achieve advanced and complex control strategies.In this paper,a power electronics experimental platform is built and the research and implementation of control strategies are carried out on this basis.The experimental platform adopts the way of sharing some components to integrate the experiments together and select the corresponding circuit experiments by toggle switches,which can realize advanced and complex control strategies without replacing the hardware circuits,with good scalability,flexibility and reliability,and meet the subsequent research on design and innovative experiments.The main contents of this topic are as follows:(1)The current status of relevant research at home and abroad is expounded,and the design concept of the power electronics experimental platform in this paper is introduced.(2)The control strategies of Boost converter,Buck converter,single-phase SPWM inverter and single-phase PWM rectifier are mainly studied.Among them,Boost converter adopts voltage closed-loop PI control;Buck converter adopts voltage and current double closed-loop PI control;single-phase SPWM inverter adopts PI+repeated parallel control;single-phase PWM rectifier adopts sliding mode control for voltage loop and quasi-PR control for current loop.(3)The hardware and software design of the system is completed.The overall hardware structure of the experimental platform is expounded,and the hardware composition and realization function of each component are briefly explained.In order to improve the readability and logic of the program,a modular structure is adopted for the DSP program design,which mainly consists of the main program,interrupt program and control algorithm program.The interrupt programs includes ADC interrupt,SCI interrupt,e PWM interrupt and e CAP interrupt;the control algorithm program includes PI control algorithm,quasi-PR control algorithm,repetitive control algorithm and sliding mode control algorithm.(4)The human-machine interface design is written in C++ language and connected to the power electronics experiment platform through USB to RS232 interface.Different circuit experiments can be selected online on the monitoring interface,and the specific values of voltage and current at the current time and the dynamic curve can be displayed in real time.(5)The physical platform is built and the control strategies proposed for each experiment are verified.The experimental results are basically consistent with the simulation results,which verifies the effectiveness and feasibility of the proposed control strategy. |
