... converters The main focus of this thesis is the analysis and design of a soft switching bi- directional DC- DC converter, including the circuit design and the FPGA based digital control design 1.1 Bi- directional ... mode, the bi- directional converter transfers power from the fuel cell to the battery or ultra-capacitor, and the energy is stored there On the other hand, if the AC load like a traction motor can ... two half bridges together, we can obtain the back- to -back bi- directional converter 1.3 Control Analysis and Design of the APHB converter To provide power to the load with high quality, the output...