Dual output interleaved PFC for alleviating mutual interference between loads during transients

Abstract

In this paper, a solution to alleviate mutual interference between the loads during load transients is presented for dual-output power server system. The output DC bus of conventional PFC (Power Factor Correction) system is modified to have independent DC bus for such tenacity. The Boost PFC converter is replaced by Interleaved Boost (IB) PFC converter and furthermore modified at the output end without betraying the operating principle of conventional PFC system. The load sharing capability of dual-output AC-DC system is being improved and the input current ripple is reduced by the modified converter system. The modified IB (MIB) PFC system can handle doubled output power compared to that of the conventional IB PFC system with same design specification. Hence, high cost and size of the converter in this regard can be limited. In this paper, the MIB PFC system is compared with that of the conventional IB PFC converter to understand its superiority based on the dual-output power supply under load transient. The modified system inherently maintains regulated output voltage at load side and simultaneously works with unity power factor (UPF). Additionally, the source current %THD is found to be less compared to that of conventional IB PFC system. Here, a prototype is designed which can operate in both 1.2kW, 500V DC interleaved boost PFC or 2 × 1.25kW, 500V DC MIB PFC mode individually with same design parameters. For both the topological arrangement, same design parameters are considered for better understanding.