Optimized power electronics interface for auxiliary power buffer based on supercapacitors

The paper focuses on a method to interface a power buffer based on supercapacitors (SCs) to a system with a stiff DC voltage. An optimized design methodology is given, showing that the proposed system is able to fully control the power flow between the SCs and the DC-link, making use of reduced-rating switching devices and magnetic components. Losses of the proposed system are analytically evaluated and compared to those of a standard Half Bridge interface. A prototype of the converter to be used on board of an existing city-vehicle is built. The vehicle is equipped with a 240 V battery and an inverter/motor system with a peak power of 30 kW. Experimental results on such a real-scale prototype validate the theory and show the feasibility of the proposed approach.