Distributed autonomous voltage balancing control for a modular IPOS DC grid-connected renewable power system

摘要

A distributed autonomous voltage balancing control strategy for an input-parallel output-series (IPOS) modular DC grid-connected renewable power system is presented and analyzed in this paper. Autonomous voltage balancing of output voltages and distributed voltage regulation of low voltage DC bus of these IPOS DC-DC modules are achieved by introducing the output voltages of DC-DC modules into the input voltage reference of each module. The information of output voltages of these modules is shared through the low voltage DC bus. Therefore, fully distributed and automatic power balancing control and hot-swap can be realized without information exchange or central controller among these modules. Simple control, easy realization and high reliability can be ensured with the presented control strategy. Experimental results are provided to verify the effectiveness and feasibility of the IPOS system and its control strategy.