A non-isolated high quadratic step-up converter for fuel cell electric vehicle applications

The fuel cell electric vehicles require a dc-dc converter as a power interface to match the fuel cell voltage to the dc bus. By considering the soft characteristics of the fuel cell source, this work introduces a non-isolated high quadratic step-up (HQSU) converter with a wide-range voltage gain and continuous source current. The proposed converter comprises two synchronously operated active switches and two inductors; it adopts a switched capacitor cell to improve the voltage gain and reduce the voltage stress of the output side components. Further, this work discusses the HQSU converter in terms of operation, steady-state analysis, design considerations, and non-ideal and dynamic analysis. In addition, the comprehensive comparison with recent quadratic converters suggests that the proposed HQSU converter has the advantages of higher voltage gain, high effectiveness index, low total voltage stress, and lower SDP rating, along with common ground and non-inverted output. Furthermore, a 200 W laboratory prototype is fabricated to validate the theoretical findings. The experimental results confirm the good steady-state and dynamic behavior of the proposed HQSU converter, which achieved an efficiency of 94.2% at rated power.