Weak Gird Control using Globally Non-overshooting/ Undershooting Controller

High penetration of Renewable Energy Sources (RESs) in the existing power grid brings numerous advantages along with some serious challenges. Most of the PV/Wind based RES units are remotely located. Long radial lines are connected between the grid and the RESs system, which makes the microgrid a weak grid. This paper addresses the control challenges of the weak grid system. A novel state-feedback control synthesis technique, namely a globally non-overshooting/ undershooting (GNOUS) state feedback controller, is designed to trace desired real and reactive powers of a weak microgrid system without any overshoot or undershoot with the desired convergence rate. The proposed control technique achieves superior performance as compared to the case of a conventional PI controller while significantly simplifying the control design procedure. Compared to other weak grid control strategies this proposed strategy is simple without using any Phase Locked Loop (PLL), making it easy to plug and play the RES system in the main grid. Various system parameters of the weak grid system have been simulated and compared with the conventional PI controller.