Switching Loss Reduction On Cascaded H-Bridge Converter With Diode Clamped Transformer Grounding Scheme

Parasitic capacitance of dc/dc transformers interfacing the cascaded H-Bridge (CHB) converter can introduce extra switching losses. A switching loss reduction method with diode clamped grounding for dc/dc transformers connecting CHB is proposed in this paper. The transformer grounding is connected to diode clamping circuit on the low voltage dc link to partially cancel the voltage charging/discharging the parasitic capacitances. Simulation and test have been demonstrated that the proposed method has reduced 53% of the parasitics induced loss and $\sim$ 6% of the total converter loss in the setup with one simple diode half-bridge clamping circuit added on each converter cell.