Control Strategy of ACDC Hybrid MicroGrid for Optimal Power Flow Management

Abstract

quotTo propose and develop a hybrid AC/DC micro-grid (with combination of Photovoltaic (PV) and a hydrogen storage system as backup) that consists of both ac and dc networks connected together by bidirectional converter. The Proposed Hybrid micro-grid would improve the dynamic performance of the Grid connected PV System (GPVS) in a day ahead market. This work deals with system integration and controller design for power management of a grid connected Microgrid system. A two level control system is implemented, comprising a supervisory controller, which ensures the power balance between intermittent PV generations, Hydrogen based energy storage, and dynamic load demand, as well as local controllers for the photovoltaic, electrolyzer, and fuel cell unit. The coordination control algorithm is proposed for smooth power transfer between ac, dc links and Tie Line for stable system operation under various generation and load conditions. Profile of AC and DC bus voltages has been analyzed especially, when the operating conditions or load capacities change under the various modes of operation. newline newline The proposed Microgrid can be advantageous in a distribution system having voltage fluctuations in close vicinity to the solar Farm. The control strategy has been proposed for voltage regulation utilizing proposed Microgrid as Reactive Power Controller. In grid connected mode, power can be imported from the grid to charge the electrolyzer or it can be injected into the grid to boost the power supplied by the Microgrid to contribute the frequency stability. MATLAB/ SIMULINK based simulations have been carried out and results are provided to show the effectiveness of the proposed control strategy. newline newlinequot newline