Weak Grid Support via MPC-IRP Controlled Shunt Active Power Filter Powered by an Energy Hub

Weak grids are highly vulnerable to power quality issues, including voltage fluctuations, harmonic distortions, and reactive power imbalances, which can compromise system stability and efficiency. This paper introduces an effective shunt active power filter (SAPF) integrated with an energy hub for comprehensive weak grid support. The SAPF uses a three-phase inverter with an LCL filter and is controlled by a model predictive control (MPC) scheme that both compensates for LCL induced resonance phenomena and tracks the reference current with high accuracy. Instantaneous reactive power (IRP) theory complements the MPC layer by precisely identifying load side harmonics and generating reference currents, enabling simultaneous harmonic mitigation and reactive power compensation. The energy hub has been emulated to enable the injection of clean active power into the grid, thereby enhancing power quality, stability and supporting the weak grid. Simulation results validate the proposed approach, demonstrating significant reductions in harmonic distortion to 3.18% and maintaining robust performance in the presence of nonlinear loads.