Coordinated Consumer Load Control by Use of Heat Pump Water Heaters for Voltage Rise Mitigation in Future Distribution System

The widespread use of photovoltaic (PV) systems may create voltage rise problem in future distribution system. In this paper, coordinated control of consumer controllable load, Heat Pump Water Heaters (HPWH), has been proposed to provide an acceptable voltage range in the future distribution system with large penetration of PV systems. HPWH is selected as controllable load due to its large thermal energy consumption and flexibility in operating time. Central controller placed at distribution substation controls the node voltage within acceptable limit by coordinately controlling the power consumption of HPWH while ensures customer convenience without hot water shortage. Optimal control parameters that determine HPWH power consumption are found and most appropriate time-varying power consumption for HPWH is obtained from maximum node voltage and HPWH characteristics. The effectiveness of proposed coordinated load control method has been verified in a model of the future residential distribution system in Japan.