Current Sharing Control of Boost PFC in Parallel Operation Without Current Detection

Conventional dual loop control scheme usually includes an input current sensed circuit for PFC control and easy module paralleling. However, for the universal 47 $\sim$ 800Hz grids, the conventional scheme fails to provide good waveform shaping due to the limited tracking speed of inner current loop. To solve the problem, the authors proposed a simple and effective method without current sensing in a previous paper. Yet, current sharing control in parallel operation is not mentioned. On this basis, this paper further proposes a parallel control scheme. Half-brick PFC modules were developed to verify the experimental results.