The analysis on effect of digital process on the performance of PWM inverter

Compared with analog control, digital control adopted in PWM inverter possesses the evident advantages but the traditional PID control strategy which is realized in digital method often can´t achieve better performance than in analog control. In past references, there is hardly quantitative analysis on the effect of digital process on the performance of PWM inverter. This paper did a creative research about the zero-order-hold process and one-step-delay control effect on the performance of PWM inverter. The process of zero-order-hold and one-step-delay control were analyzed why the digital process influences PWM inverter´s performance in this paper. The process of zero-order-hold and one-step-delay control varies the system´s stability with sample time. Zero-order-hold reduces the stable scope to a large extent compared with analog control, and limits the performance improvement of digital control system. One-step-delay with different sample time brings different influence on the system stability. Finally relevant experiments in a single phase inverter verify the theoretical analysis on the effect of digital process on the performance of PWM inverter.