A novel voltage — Control method in low-voltage distribution systems: Cooperative — Autonomous switching control

This paper proposes a novel voltage control method for cooperative-autonomous switching control. In power systems, the presence of a large number of photovoltaic (PV) systems in a small district leads to deviations in voltage from the upper limit of the specified voltage range. Autonomous active power control leads to inequalities of the PV generation power on the same distribution line. Cooperative active power control improves the inequality, whereas the power is significantly curtailed. In this paper, the proposed method is based on the setting of a reference value to decrease the curtailment power of cooperative active power control, which will decrease the curtailment power. The control method will be changed to autonomous active power control when the curtailment power reaches a predetermined reference value. Several computer simulations have been performed on the distribution line in order to test the performance of cooperative-autonomous switching control. The total energy of the proposed method increases to 13.71 kWh compared to cooperative active power and cooperative reactive power control. The maximum PV energy disparity decreases to 1.38 kWh compared to that of autonomous active power and cooperative reactive power control.