Study on feasible region of voltage control strategies for closing loop operation in large power grids

Electromagnetic loops are inevitable with the development of power systems. Voltage control strategies for closing loop operation often attract much attention, especially when the transmission line is long-distance with large amounts of surplus reactive power. A method is proposed to compute the feasible region of voltage control strategies for closing loop operation in large power grids. A two-port Thevenin equivalent circuit is built up at both sides of the closing loop point. Sensitivities of voltage difference and voltage variations to reactive power exchange are deduced. Then an algorithm is put forward to compute the feasible region of voltage control strategies. Finally, the proposed algorithm is tested on a practical power grid. Simulation results and field applications demonstrate its effectiveness and feasibility.