Voltage and Frequency Control for Hybrid Stand-Alone Power Systems For Isolated Communities

Abstract

This paper proposes a control and overall coordination of a hybrid stand-alone power system. The system may comprise a wind turbine, fuel cell, electrolyzer, battery storage, diesel generator and a set of loads. The overall control planning of the hybrid system is based on a two-level structure. The top-level is the energy management and power regulation system. Depending on wind and load conditions, this system generates reference dynamic operating points to low-level individual sub-systems. The energy management and power regulation system also controls the load scheduling operation during unfavourable wind conditions with inadequate energy storage in order to avoid a system black-out. Based on the reference dynamic operating points of the individual sub-systems, the local controllers control the wind turbine, fuel cell, electrolyzer and battery storage units. The proposed control system is implemented in MATLAB Simpower software and tested for various wind and load conditions. Results are presented and elucidated.