BATTERY ENERGY-STORAGE-INTEGRATED DSTATCOM CONTROL FOR POWER QUALITY IMPROVEMENT IN HYBRID RENEWABLE MICROGRID

Abstract

In the recent years, the development of Solar Photovoltaic systems (PV) and Wind Energy Devices (WEDs) has made an immense contribution to power distribution systems (PDS). On one hand, it is possible to state the significant environmental and economic advantages associated with the integration of renewable energy. On the other hand, due to its variability, intermittent nature, and unstable character, renewable energy integration can provoke numerous problems associated with the quality of power in PDS. These include such aspects as voltage sags; harmonic distortion; reactive power imbalance; poor power factor; and frequency fluctuation/stability. All these factors make the problem of enhancing performance and stability of Hybrid Renewable Microgrids (HRMGs) very challenging. For this reason, it is extremely important to design efficient Power Quality Enhancement Techniques (PQETs) in order to preserve all advantages linked with HRMG operation. The research conducted as a part of this thesis includes the implementation of an innovative Battery Energy Storage Integrated Distribution Static Compensator (BESS DSTATCOM) aimed at improving power quality parameters of Hybrid Renewable Microgrids. This PQET combines Battery Energy Storage System (BESS) and Voltage Source Converter (VSC)-based DSTATCOM and provides active and reactive power compensation under changing operating conditions. The employment of battery energy storage system increases the capabilities of DSTATCOMs and provides the possibility to ensure energy balance of hybrid renewable microgrids. The mathematical model of Hybrid Renewable Microgrid (HRMG); Solar PV system; Battery Energy Storage System; and DSTATCOM has been elaborated. Advanced control strategy based on reference current generation and DC-link voltage regulation provides efficient compensation of harmonics, provision of reactive power and load balancing, and effective voltage regulation. The entire system has been modeled and simulated using MATLAB/Simulink environment and a number of different operating conditions have been considered. Simulation results prove the high efficiency of the proposed PQET. Low values of Total Harmonic Distortion (THD) of the source current, voltage regulation, power factor correction and reactive power compensation are provided by the proposed PQET. Moreover, the use of battery energy storage enhances the capabilities of DSTATCOM providing more stable and reliable operation of the microgrid. Battery Energy Storage Integrated DSTATCOM represents a promising and reliable approach to the problem of enhancing quality of electricity production in hybrid renewable microgrids. It holds great potential for further research on the basis of renewable energy and smart grids technologies.