Price-Optimized heat pump operation considering LV distribution grid constraints

Rising usage of heat pumps (HPs) for heating in buildings can overload lowvoltage (LV) distribution grids, threatening grid stability. The German Federal Grid Agency proposed solutions based on § 14a EnWG with reactive measures from the DSO to address overloading by reducing the power to a minimum of 4.2 kW. This study proposes a preventive control strategy for HPs integrated with Home Energy Management Systems (HEMS). The objective is to minimize household electricity costs while preventing overloading through time-dependent power reductions. Unlike most existing solutions, this approach proactively reduces HP power consumption based on predicted grid load. Simulations were conducted using a combination of tools (pandapower, microSCOPE, pandaprosumer) to evaluate the effectiveness of the proposed control strategy. The simulations compared scenarios with and without the control strategy, considering different HP sizes, thermal storage sizes, and sensitivity analysis. The results demonstrate the functionality of the preventive control strategy in reducing transformer overloading. However, the effectiveness is limited during long periods with particularly low temperatures. Also, it is influenced by factors such as HP size relative to building heat load and thermal storage capacity. Further research is needed to generalize the findings and include more factors.