Intelligent Charging Load Management in Combination with Local Energy Systems for Residential, Commercial and Industrial Buildings

Electric vehicles represent a promising technology for a sustainable transport sector with reduced CO₂ emissions, especially if the vehicles can be charged with electricity from renewable energy sources. The present work describes an intelligent charging load management system for electric vehicles with integrated charging optimization, which prevents the overloading of operating resources in buildings during multiple simultaneous charging processes and considers local renewable energy sources like PV or biogas fired CHP units. The developed charging load management system can be easily adapted to site-specific conditions and offers an intuitive web-based observation, monitoring and remote maintenance tool for charging infrastructure operators. The intelligent load management avoids in many cases the need for cost-intensive building connection or grid expansions. To make active use of electricity from onsite renewable energy systems, prioritized charging has been developed for a charging load management system. Based on a ramp-up or ramp-down algorithm, a deterministic integer optimization takes place, which also includes a phase-accurate power distribution. The utilization of local renewable electricity increases the general cost effectiveness and in Germany brings additional financial income for public and semi-public charging point operators due to an increased GHG quota from greenhouse gas trading. Furthermore, prioritized charging can be used to react on flexible electricity prices to further minimize costs.

A developed simulation model has been coupled with the control software in a software in the loop environment, to analyze the implemented functionalities of the intelligent charging load management. Input parameters include real vehicle data, generator profiles of a photovoltaic system and a building load profile to obtain realistic simulation results. For electric car charging, measured charging curves have been used. As part of the validation, the functionalities of standard charging load management, the integration of renewable energies, prioritized charging and interactions of different charging modes could be successfully investigated. Initial tests proved how the integrated load management works in real operation.