An Optimized Nonlinear Droop Control Method Using Load Profile for DC Microgrids

Paralleling of power electronic converters to achieve current sharing is a critical aspect of a dc microgrid. Droop control is a popular technique to parallel converters. This article presents a novel perspective of different practically realizable nonlinear droop characteristics. Using the probability distribution function of the load current, a methodology is proposed to optimize the characteristics of nonlinear droop control. In a stand-alone dc microgrid system, the load current information used in the proposed control method is typically known using historical data or can be estimated using load forecasting methods. The advantages of the proposed nonlinear droop control method over several state-of-the art nonlinear droop control methods are discussed and shown. The effectiveness of the proposed nonlinear droop control method is validated using circuit simulations and hardware-based experiments on a multiconverter system for different load profiles.