Monitoring and control of charging infrastructure for electric vehicles: a solution suitable for retrofit

Abstract

This study presents a proof of concept (PoC) for the implementation of measures to control electric vehicle (EV) chargers in existing infrastructures. The PoC was realised by ewz, the utility of Zurich, in cooperation with the Start-Up Fleco Power, who have developed an innovative solution for charging control, which is suitable for retrofits. In the PoC, a schedule with a resolution of 15 min was updated daily by ewz and transmitted to the charging infrastructure. In the successful implementation of two test cases, the behaviour of various EVs was investigated for blocked charging (test case 1) and at reduced charging current (test case 2). The PoC demonstrated that it is possible to retrofit controllability to EV chargers using a cost-effective hardware platform. In addition, it was found that the behaviour of the EVs varied widely in the case of complete blocking and that the EVs react more predictably if the charging current is only reduced rather than blocked. Moreover, a significant deterioration of the power factor cos(f) was found with a reduced charging current.