Impacts of PWM inverter in digitization process and design of its correction part

Compared with traditional analog control, digital control has many prominent advantages, but it also introduces new problems, the most important one is time delay in the process of digitization. This paper studies the mathematical model in the process of digital sampling, holding and one-step-delay control, then establishes an accurate mathematical model of the inverter considering of the time delay, theoretically analyses the differences between analog control model and digital control model. An inverter control transfer function was designed based on the accurate inverter model, and a model of digital and analog hybrid simulation was established in MATLAB. Simulation studies and prototype experiments results have proved the validity of the above analysis.