Coordinated Controls of Residential EV Chargers Considering High Power Appliances

In addition to electric vehicle (EV) adoption, the electricity demand of the modern grid is also under change from the replacement of resistive electric water heaters (EWHs) with high-efficiency heat pump electric water heaters (HPWH). Typical load of a HPWH has two parts: a low power compressor and a backup high power resistive boosting element. Within this paper, residential load from a large field demonstration for over one thousand homes is simulated in virtual power plant (VPP) operation with realistic HPWH and EV synthetic modules based on big data from the latest CBECC-Res and National Household Travel Survey (NHTS). Simultaneous uncontrolled EV charging and HPWH boosting element operation cause short duration residential transformer overload and increase peak demand. The coordinated control of EV charging power based on HPWH and heating ventilation and air-conditioning (HVAC) system loads using industry standard commands, including CTA-2045 protocol, to maintain human comfort and reduce the peak power experienced by residential transformers that supply multiple houses is proposed. It is shown that the coordinated controls may reduce peak power by temporarily suspending EV charging based on future HPWH operation.