The Fuzzy Control Of APFC Switching Power Supply

With the comprehensive application of power electronics equipments, the problem of mains harmonic and pollution becomes more and more serious, which causes inconvenience of the industry production and society life.Eliminating harmonics and increasing power factor has been becoming a hot topic both in power electronics and in the society as well.Power-Factor-Correction (PFC) is a state-of-art technique for reducing harmonic distortion and increasing the power supply network efficiency. Power-Factor (PF) is one of the quality indices of electric equipment, and the Active-Power-Factor-Correction (APFC) technique is the fundamental way to improve it.In accordance with the nonlinear and time-varying characteristics of the APFC system, this theme researches the application of Fuzzy control in the APFC system. According to BOOST circuit witch power is 1000W, this theme designs a fuzzy PI controller. And then, the fuzzy PI controller is applied the system of APFC. After simulation, the results show that this controller is better than PID controller.With the development of the digital technique, more and more control algorithms can be implemented in power electronics by the digital control. The merits of digital control: simple hardware, no temperature drift, flexible control and easy to realize advanced arithmetic etc, make digital control technique to be used in power supply manufacture to let it more credible and easier to realize in batches with lower costs. In the current it is popular to use digital control in switching power supply design.Therefore, for raise switching frequency and control accuracy, this paper presents a method of designing fuzzy controller of APFC switching power supply using FPGA. An APFC system is designed, after computation and simulation, the results show that this design can raise obviously the power factor of system, and this design has the many advantages, for example, simple algorithm, rapid response, and high accuracy.Finally, the hardware circuit is designed with a core of EP1K30QC208 slug.