A Tie-line Power Smoothing Method for Microgrid Using Residential Thermostatically-controlled Loads

Abstract

The intermission and uncertainty of renewable energy lead to many operation problems existing in power systems.Traditional method witnesses operational challenges to smooth renewable fluctuations due to the high operating cost limits of conventional storage devices.This paper presented a novel micro-grid(MG) tie-line power flow smoothing algorithm using residential thermostatically-controlled loads.The thermal dynamic of the heat pump was modeled by a simplified first-order equivalent thermal parameter model.The smoothing algorithm controlled the heat pumps based on a state-queueing control strategy through a reliable 2-way communication system.In a grid-connected community-based microgrid,1?000 residential electric heat pumps were simulated to provide this demand-side power smoothing service.The simulation results demonstrate that the algorithm is effective and robust.Sensitivity analysis was conducted for renewable penetrations,ambient temperatures,and the lower and upper limits of operating indoor temperatures and various impacts can be investigated.The results pave the path for a generalized energy storage system for future smart grid implementations.