High Voltage, High Power Density Bi-Directional Multi-Level Converters Utilizing Silicon and Silicon Carbide (SiC) Switches

The objective of this Small Business Innovation Research Phase I project is to develop an isolated bi-directional ac-dc PCM-4 using a novel multi-level modular design approach compatible with silicon carbide (SiC) power switches. The multi-level PCM Module will allow for the design of power-dense, high-voltage, high-power ac-dc converters utilizing fast-switching, low-voltage power devices and high-frequency isolation transformers (15-25 kHz). The US Navy need for improved reliability and survivability of the shipboard electrical power system can be met by the implementation of the Integrated Fight Through Power (IFTP) concept. This concept requires the development of megawatt-class power conversion modules (PCM) to divide the ship’s electric power distribution system into several isolated zones. These isolated and bi-directional ac-dc PCMs are connected to the ship’s three-phase 4.1kV-13.8kV power generation system on one side and to the 0.7kV-1kV dc power distribution system on the other side. The design of these very high-voltage, high-power (~ 4 MW) PCMs is currently limited due to the lack of high-voltage power devices that can attain the high switching frequencies necessary to achieve a reasonable power density of the isolation transformer (> 10kHz). Therefore, the successful development of such PCMs requires the use of innovative converter topologies that can utilize the latest power devices technology.