SiC heat pump converters with support for voltage unbalance in distribution grids

This paper studies the impact of involving the demand side of the LV grid into the grid conditioning process. Heat pumps are distribution loads with a substation capacity increase in the last years, with expectancy of growth in the coming years. Controlling the loads is the first step in the transition to smart grids, and heat pumps are to be the first promising smart loads. They can be used for load shedding but also for unbalance compensation purposes. When they are equipped with a back to back compressor drive and a proper control strategy, grid support can be provided to reduce the negative sequence component in the voltage at the installation point. Two control strategies are proposed and investigated experimentally on a SiC heat pump converter prototype.