Scheduled Operation of Heat Pump Water Heater for Voltage Control in Distribution System with Large Penetration of PV Systems

It is expected that large capacity distributed generation (DG) systems including photovoltaic (PV) power systems will be installed in future power systems. When the capacity of PV power systems installed in the distribution system increases, voltage of the system goes beyond the allowable voltage range due to reverse power flow from PV power systems. In order to minimize this problem, load control at the customer end would be a possible solution. In this paper, application of controllable customer equipment, Heat Pump Water Heater (HPWH), has been proposed in order to mitigate voltage violation. The input power of HPWH is applied in three different ways: rated input, step input and multiple inputs so as to find the optimum solution that keeps the voltage within allowable limit.