Analysis And Design Of Boost PFC Circuits Operating In CCM Mode

With the rapid development of power electronics technology, a variety of electronic intruments are more and more widely used. People have paid more attention on consequent issues including improvement of power efficiency, reduction of harmonic pollution to the power network and reliability of electronic products. In fact, power factor correction(PFC) technology is the key to all these problems. With PWM regulation signal, PFC circuit forces the input current mimicking the rectified sinusoidal input voltage both in amplitude and in phase, which significantly reduces the harmonic pollution of input current. Thus power factor correction is achieved.A PFC interagted cuircuit based on average current mode in CCM is designed in this thesis. Firstly, the principle of power factor correction and power factor correction methods are briefly introduced. Then, active power factor correction is introduced in detail. Common control methods, major current conduction mode and model analysis are enclosed. Furthermore after steady state analyzing the circuit model operating in CCM average current mode based on Boost structure, the theoretical design, Pole-Zero analysis and mathematical derivation of dual-loop control strategy are described in this paper.This Boost PFC circuit operating in CCM average current mode is designed and simulated under 0.25μm 15 V BCD process. All modules and the whole circuit are simulated by Hspice. In typical application of 300 W output power, the power factor of the system is more than 0.99. Meanwhile the THD is controlled within 12%. The simulation results show that characteristic parameters of this PFC circuit meet the expected requirement. It proves that the designed PFC circuit can achieve power factor correction effectively.