Novel control for boost PFC modules in parallel operation

In this paper, a current sharing control strategy based on average current principle is proposed for power factor correction (PFC) converters operating in parallel. When paralleling, as the boost PFC converter is non-isolation, the input current must be sensed by transformers to realize power factor correction. At the same time, the parallel system requires current sharing to achieve favorable performance. To satisfy the requirements, this paper proposes an improved integrated current sensing circuit for both PFC and output current sharing without adding an additional transformer. Furthermore, the operation principle of the current sharing control and the sensitivity are analyzed. The key design consideration is presented. Finally, an experimental prototype is developed to verify the proposed method, both input current and output current sharing control strategy is respectively applied to a PFC converter parallel system. And the experimental results are given to verify the research and analysis.