Consideration of Power Line Capacity and Impact on Voltage Band Compliance in Local Energy Markets

Local energy markets (LEMs) are a concept for the integration of volatile renewable energy plants and increasing demand from sector coupling (electric vehicles, heat pumps) into the energy system. So far, the focus of research has been on market integration of prosumers, neglecting the effects of LEMs on the distribution grid. This paper therefore presents a market design that ensures validity of the market outcome in terms of line utilization and further reserves capacity for the application of reactive power for voltage control. First, Power Transfer Distribution Factors are used to estimate the line utilization when determining the market outcome. In a second step, a reactive power schedule is calculated by an AC optimal power flow that meets voltage limits in addition to thermal line restrictions. The presented method is evaluated using a real low voltage network in the Allgäu region (Southern Bavaria, Germany). The analysis shows that in the future scenario studied, violations of network restrictions can be avoided by using an LEM in combination with the presented methodology.