Optimal load management of electric heating and PEV loads in a residential distribution system in Sweden

The electrical distribution system is facing major challenges in the near future related to increased electricity consumption, increased amount of distributed generation (DG) and the introduction of plug-in electric vehicles (PEVs). These could require large investments in the distribution system to maintain and operate the system in a secure way. However, the need to reinforce the distribution system can be avoided or postponed if the loads could be managed and controlled in order to reduce the peak load in the system. This paper examines the possibility for such a load management scheme in a residential part of the distribution system in the city of Gothenburg, Sweden. The load management scheme aims to minimize the losses in the system by shifting the heat loads and PEV charging in time without reducing the comfort level of the customers. In addition, a price-based optimal strategy is proposed, assuming dynamic electricity rates, that aims to minimize the electricity cost for the customers. The results indicate that the peak load can be decreased by the proposed load management scheme and that the number of PEVs that can be handled by the distribution system increases. However, dynamic electricity rates can cause increased peak power demand, indicating that either an aggregator or more advanced approaches for the electricity tariffs are needed to cope with the peak power.