Transient voltage and frequency stability of an isolated microgrid based on energy storage systems

Abstract

Microgrid (MG) based on energy storage systems to share the load between distributed generation plants in operation mode is the main issue in MG. Stability is an important component in energy management and planning of MG especially in duration of system's operation such as fault occurrence in system. In this article, frequency and voltage control based on active and reactive power control methods are analyzed. Studies demonstrate that MG stable operation in cases of proper use of control strategies is existing. MG system control due to stability improvement in islanding mode (autonomous mode) after fault occurrence at upstream network are been studying. MG system in this article included two distributed generation (DG) units. All of DG units and loads are connected in parallel at point of common coupling (PCC). In islanding mode, according to violence dependence of system's dynamic to local load changes and stability improvement after fault occurrence, design of controller algorithm is necessary. In this article, demonstrate that to frequency-load control, one of DG units is master and the other one is slave. Proposed controller based on energy storage system is design according to load uncertain. In final section of article, due to demonstrating the improvement and superior robustness of proposed controller to load dynamic, fault occurrence in system and controller capability in over demand supply and decrease short term produced power, frequency and voltage control by energy storage system cooperation that is one of novelty in this article, consider a comparison between classic and proposed controller. Proposed control strategy under two scenarios (load change and fault occurrence) has a good performance. Finally, propose controller superior robustness performance evaluated by MATLAB software.