To design optimized fuzzy and digital PID controllers for a single phase power factor preregulator-genetic algorithm approach

The optimized fuzzy logic and digital PID controllers for a single-phase power factor correction (PFC) converter used in an online uninterruptible power supply (UPS) are proposed in this paper. Parameters such as input membership functions, output membership functions, inference rules of fuzzy logic controller and proportional gain, integral gain and derivative gain of digital PID controller are selected and optimized by genetic algorithms; hence the tedious and time consuming parameters tuning process normally associated with fuzzy logic and digital PID controllers design is eliminated. The selection and optimization criteria are based on time domain specifications such as response time, percent of overshoot etc. for a step reference. The simulation shows excellent results in terms of response time and output overshoot for a step reference. This design approach provides an attractive alternative method to select and optimize the parameters of fuzzy logic and digital PID controllers when they are used to control a single-phase PFC converter. It can also be easily extended to applications for switching regulator control loop design