Improvement of Stability and Power Factor in PCM Controlled Boost PFC Converter With Hybrid Dynamic Compensation

Traditional slope compensation (SC) method is an effective way to control fast-scale instabilities present in peak current mode (PCM) controlled boost PFC converters. However, with the SC method, envelope of inductor current deviates from a desired sinusoid especially near the zero crossings, which causes the system power factor to reduce to values lower than what is possible without compensation. To tackle this problem we propose a hybrid dynamic compensation (HDC) scheme, which incorporates a combination of zero-perturbation dynamic compensation (ZPDC) and ripple compensation. The proposed HDC scheme can suppress the fast-scale instabilities and also ensure average inductor current tracks a desired sinusoidal reference which is not possible with the ZPDC scheme alone where only the peak inductor current can track a desired sinusoidal signal. Furthermore, with the proposed HDC scheme the total harmonic distortion (THD) and power factor (PF) are improved in comparison to the SC and ZPDC schemes as well as to the case without compensation. Moreover, operating range of a control parameter is determined analytically subject to some assumptions. Extensive simulation and experimental results are provided to validate the theoretical analysis and the feasibility of the proposed HDC scheme.