Comparative research of digital-PID and sliding mode control strategy for DC/DC converter

Based on the fixed frequency PWM control strategy, this paper introduced a DSP-based digital PID control technology and a sliding mode variable structure control theory for high frequency DC/DC converter in detail. Firstly, a traditional analogy sliding mode controller with the reaching law and a digital PID controller are designed. Then experimental prototypes for two kind of DC/DC converters are constructed and comparative experiment are implemented. The experiment results show that DC/DC converter by using digital PID controller have fast dynamic response and high accuracy in the presence of the input voltage fluctuation and load variation.