Analysis of the Integration of a DC-Charging Station Into a Tram Grid by Using Long- Term Field Measurements and a PHiL Setup

Abstract

The electrification of the transport sector is accompanied by a massive increase of charging infrastructure which is supplied by the public distribution grid. Grid reinforcements and expansions are necessary. This publication investigates an alternative by using an existing DC-electric tram grid as the supply source. For this, long term field measurements of one year at the tram grid of Nordhausen, Germany, are presented. Furthermore, a realistic Power-Hardware-in-the-Loop (PHiL) test environment based on measurement data and a simulation model of the tram grid is realised picturing the highly fluctuating grid behaviour. The simulation model is validated based on the field measurement data and the deviation to measured data is calculated. The PHiL environment is used for tests with a 50kW charging station demonstrator that performs a complete charging cycle of an emulated electric vehicle (EV). The additional voltage drop and load on the tram grid that is caused by the charging process is shown and compared to a scenario without electric charging.

Keywords

• Electric charging
• EVSE
• electric tram grid
• electric tram
• DC-grid
• field measurement