MULTIFUNCTIONAL DEVICE FOR INTEGRATING RENEWABLE ENERGY GENERATED FROM RES INTO EXISTING DISTRIBUTION NETWORKS

This paper presents the design and simulation-based validation of a multifunctional inverter system for the effective integration of renewable energy sources (RES) into existing distribution networks. The proposed system combines photovoltaic (PV) panels, wind energy conversion systems, and a battery energy storage system (BESS), interfaced via a common DC bus and controlled using a Synchronous Reference Frame (SRF)-based strategy. The control scheme enables the inverter to perform dual functions: injecting active power from RES and compensating for current harmonics caused by nonlinear loads. The proposed system is designed and validated through MATLAB/Simulink simulations, with the developed model structure and case studies presented in the paper. The performance of the system is evaluated under two case studies using MATLAB/Simulink. In the first case, dynamic injection of active power is achieved when solar generation is introduced to supplement wind energy, with the inverter ensuring smooth transition and maintaining the Total Harmonic Distortion (THD) of the grid current within IEEE 519 standards. In the second case, the system is tested under distorted grid voltage and nonlinear loading conditions. The inverter successfully reduces the total harmonic distortion (THD) of the grid current from 26.18% to 3.71%, confirming its robustness in real-world scenarios. These results demonstrate that the multifunctional inverter effectively supports power quality enhancement, synchronization, and the integration of renewable energy sources, making it a suitable solution for smart and resilient power distribution systems.