IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

341 / 2017-12-08 23:45:37

A High Efficiency 60kW bi-directional DC-DC converter Based on SiC MOSFET

Plenary track > Very high efficiency and compact converters

Abstract: High-power bi-directional DC-DC converter which can be widely used in the field of power electronic transformers, energy storage, electric vehicle charging piles, have some issue such as low efficiency and large volume because of the characteristics limits of Si devices.This paper study the characteristics of the commercial 1700V 300A SiC MOSFET module and compares it with state-of-the-art silicon 1700V 300A IGBT with the same same packaging using the double pulse test circuit. The results show that the SiC MOSFET has faster switching speed and much lower loss compared with silicon IGBT. Moreover, the silicon IGBT switching loss will increase significantly for higher operation temperature,while the SiC MOSFET switching loss is almost the same for different temperature. Based on this, this paper design a 60 kW bi-directional DC-DC converter with 1000V dc input and 1000Vdc output voltage. Then a model has been implemented in MATLAB to simulate the control strategy and to compute the circuit parameters.At the same time a loss model has been implemented in PLECS in order to simulate the losses. Two 60 kW bi-directional DC-DC converter prototype has been built to do the contrast test under the same condition . One of them is built based on1700V 300A SiC MOSFET , and the other is built based on 1700V 300A Si IGBT. The test results match with the simulation very well. Comparing to the converter based on Si IGBT，the volume of the converter based on SiC MOSFET can be reduced more than 50 percent, and the efficiency can be increased to 97.8% from 94.3% with 10 kHz switching frequency. Eventually we concluded that, compared with conventional Si IGBT-based bidirectional DC-DC converter, the bidirectional DC-DC converter based on SiC MOSFET can effectively improve the efficiency and reduce the volume.