Power Quality Improvement of Electrical Distribution Network using Battery Energy Storage System

Abstract

Contemporary times have witnessed a surge in the popularity of grid-connected systems powered by renewable energy sources. Combining more than two renewable sources, such as photovoltaic (PV) and Permanent Magnet Synchronous Generator (PMSG) wind power generation, has gained international recognition. However, the variability of wind power generation linked to wind speed and PV power generation tied to solar irradiance results in power generation fluctuations due to weather and atmospheric changes. To effectively mitigate these rapid and unpredictable alterations, an energy storage system is necessary. Among energy storing devices, battery energy storage systems (BESS) are found to be the utmost efficient solution for minimizing system fluctuations when paired with an appropriate controller. This study introduces the application of Takagi Sugeno-Fuzzy Logic Controller (TS-FLC) in a hybrid wind-PV-battery energy storage system (BESS) integrated with the grid. The TS-FLC is deployed on both the DC and AC sides to effectively manage system dynamics and address grid challenges. The TS-FLC controls the bidirectional DC to DC converter linking the BESS to the DC-link, and the inverter facilitating grid connection. The inverter controller serves a dual role by harmonizing grid currents, mitigating harmonics from nonlinear loads, and fulfilling reactive power demand. Moreover, it operates as a maximum power point tracker (MPPT) for the PV system, eliminating the need for a separate converter as the battery's State of Charge (SoC) reaches threshold levels. MATLAB simulations demonstrate the TS-FLC's superiority over the Proportional Integral (PI) controller, showcasing its ability to reduce source current harmonics to 0.08% (steady-state) and 0.10% (with fault). Also, TS-FLC is compared with another intelligent technique, Artificial Neural Network (ANN), other than the PI controller. Under unbalanced and nonlinear load conditions, the TS-FLC method demonstrates superior performance over the ANN method, achieving a lower THD of 3.94% compared to 4.74% for ANN. Additionally, under balanced and nonlinear load conditions, TS-FLC significantly outperforms ANN, with a markedly lower THD of 0.10% compared to ANN's 1.32%. These values adhere to IEEE-519 standards. Under various contingency conditions, TS-FLC proves to be highly efficient at filtering harmonic distortions, thereby improving power quality. No technical study is complete without economic analysis, which evaluates the financial implications and viability of technical solutions. Economic analysis complements technical assessment by prioritizing cost-effective alternatives, assessing long-term sustainability, and mitigating financial risks. Integrating economic considerations ensures informed decision-making, optimal resource allocation, and compliance with regulatory 5 requirements. Techno-economic analysis compares the performance of PV-BESS based system and wind-BESS based systems in both stand-alone and grid-connected configurations. The hybrid optimization model for electric renewable (HOMER) program was also used to explore a hybrid renewable energy system (HRES) (Version 3.14.0). Two combinations of HRES: i) Solar photovoltaic (PV)/wind/tidal/fuel-cell (with battery energy storage system (BESS)) and ii) PV/wind/tidal/fuel-cell (without BESS), have been considered for the community load. When compared to other existing evolutionary approaches the proposed algorithm, Aquila optimizer (AQ), yields the best results. In addition, statistical analysis using MATLAB/SIMULINK yielded the results of the Friedman Ranking Test that demonstrated the proposed algorithm's improved performance and robustness as AQ netted the first position in the test's outcomes. Though the system in case 1 is more cost-effective with net present cost (NPC) (1,16,226.40$) and least levelized cost of electricity (LCOE) is (0.3017) as compared to case 2’s NPC (1,26,152$) and LCOE (0.3287), but case 1 is more efficient in terms of power quality as the total harmonic distortion (THD) (0.06 percent) as compared with case 2 THD (30.31%) which is unacceptable according to IEEE-519 standard, (THD < 5%). Hence, case 1 HRES is more viable for producing clean energy with effective storage and better power quality mitigation in order to monitor the whole distribution network. This study underscores the efficacy and adaptability of TS-FLC controllers in bolstering the stability and sustainability of grid-connected as well as stand-alone renewable energy systems.