Research On Single-phase High Power Factor Rectifier And Its Control Strategy

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. Many standards have been provided to restrict harmonic current of the load, such as IEC61000-3-2-4-6 of IEC and GB17625.1-1998 of China. Meanwhile, experts have done many researches on it, the main idea of eliminating harmonic and PFC is making the AC current to be sinusoidal and limiting its phase error to the voltage wave, so as to realize high power factor.Recently, the single phase high power factor rectifier is widely used, but it's only used in middle and small power range, many of its performances couldn't satisfy people's higher and higher requirements, including power density, switching loss, transmission efficiency, system cost, electromagnetic pollution and harmonic distortion, and so on.So, designing novel topology main circuit structure, and using advanced control strategy in PWM rectifier is one of the main measures to improve rectifying quality and system performance, and it's an important direction of single phase high power factor rectifier.For the problems discussed above, the aspects researched in this paper are listed as follows:1. Conception, hazard, meaning and object of power factor correction are detail analyzed, and some of its main strategies are introduced.2. Topology circuit of a novel rectifier is analyzed, and its ideal switch model, state space model, small signal mathematic model are derived, and simulation of the circuit is also given.3. A novel single phase power factor rectifier is designed. With novel bridgeless topology structure and high power factor rectifier IC L4981A, A small power rectifier with the performances of low price and high power factor is designed.4. Fuzzy PID control and zero phase error tracking control on the rectifier are analyzed, and simulation results of MTLAB show their great control performance.Experimental result shows: the rectifier could enlarge power factor and reduce harmonic effectively;fuzzy PID could improve the rectifier's performance including stable, robust and anti-interrupt;and ZPETC could improve the system's tracking precise and response speed. So it could be predicted that single phase high power factor and its combination with some advanced control algorithms could have a comprehensive implicating future.