Multi Agent Control Based Energy Optimisation of a Prosumer Household and a Community with Bidirectional Electric Vehicles

Abstract

Prosumer households with photovoltaic systems face the problem of occasionally generating electricity that cannot be used within the house but must be fed into the electricity grid. This is not desired since with changing policies in Germany, the feed-in tariff has been reduced considerably and the cost of power consumed from the grid has increased significantly. To consume more solar power instead of feeding it into the grid the excess solar power can be consumed by a bidirectional electric vehicle present at the household. Additionally, this system can supply power to the household if solar power is insufficient. This study presents how bidirectional electric vehicles can optimise the self-consumption of solar photovoltaic energy and increase the self-sufficiency of the loads in a household and a community (i.e. group of households) by a hierarchical structure of control systems: car, household and community. They are optimising power flow locally and additionally consider information from the overand underlying controllers. The car controller is a bidirectional charging station where the electric vehicle is connected. It takes user preferences that are used by the household controller to perform power optimisation by handling the mismatch between generation and demand. The community level controller performs an on-the-top optimisation which reduces the power flow between the community and the electricity grid. The effect of the proposed system is investigated on a reference distribution grid simulated in the software package DIgSILENT PowerFactory whereas the control framework is developed in Python. Real load and irradiation profiles are used to execute the simulations. The results show that there is a 31% and 48% increase in the self-consumption and self-sufficiency on a household level whereas a 30% and 50% increase on a community level when the coordinated control system is implemented.