Award "Most Significant Innovation in Electric Vehicles" for TU Delft and PRE

The award was presented at the IDTechEx Show! (11-12 April, 2018, Berlin). The developed solar powered bidirectional EV charger is the first of its kind charger in the world that provides direct DC charging of EV from PV. The integrated solution allows the sustainable charging of EV from locally generated PV power and makes the charger less dependent on the grid. Currently, solar EV charging stations work on alternating current (AC) by using two separate DC/AC inverters to charge the EV from PV over the AC grid. However, this is not efficient and cost-effective for two reasons. First, EV and PV are fundamentally direct current (DC) in nature, so conversion to AC leads to unnecessary conversion steps and losses. Secondly, using two DC/AC inverters, one for PV and one for EV increases the size and cost of the power converters. Further, existing EV chargers are unidirectional, and there is no communication between the PV and EV for coordinating the EV charging based on PV generation. The developed solar EV charger overcomes the above challenges by proving an integrated DC solution.

The developed system acts as both a solar inverter and a bidirectional EV charger and can realize four power flows: EV à PV, EV àGrid, Grid à EV, PV à Grid. The unique design facilitates the EV battery to be used as a storage for the PV and can support the grid via V2G. The developed charger has a three times smaller size than existing solutions based on AC power exchange. This is an important factor as the chargers will occupy a small space in the parking lot. Moreover, the developed charger has a much higher peak (+2%) and partial load efficiency (+15%) than state-of-the-art solutions. This is vital because smart charging will occur in the future at partial load powers, less than the nominal power. The modular design of the power electronics allows it to be used in a variety of applications besides solar powered EV charging.