This paper details design, development and testing of a prototype 30kW, 200V/900V resonant DC/DC converter. The converter achieves stepping ratio of 4.5 without internal AC transformer, and is capable of bidirectional DC power flow as well as fast DC power reversal. Very importantly, it has capability of DC fault isolation on either side, which is of extreme importance for high-power DC applications. The design and selection of the individual passive and active components is presented. A 30kW test setup including one 900V voltage source converter (VSC), one 200V VSC, and one 200V current source converter (CSC) are designed and built to provide a suitable test rig for prototype DC/DC converter. The analytical studies of efficiency are compared with the detailed converter measured efficiency. The prototype shows overall efficiency of around 92% at full power and weight of around 32kg, which is promising for scaling to high power applications. The converter operation at full power in step up mode as well as step down mode, and fast power reversal when connected to CSC on its low voltage side, are demonstrated by experimental results. Severe pole-to-pole DC faults are applied on 900V and 200V DC terminals and the inherent DC fault isolation capability is confirmed.
- dc/dc power conversion
- dc power transmission
- HVDC converters
- resonant power conversion
Hajian, M., Robinson, J., Jovcic, D., & Wu, B. (2014). 30kW, 200V/900V, thyristor LCL DC/DC converter laboratory prototype design and testing. IEEE transactions on power electronics, 29(3), 1094-1102. https://doi.org/10.1109/TPEL.2013.2260564