Low cost fuel cell inverter system for residential power generation

The high installation cost is the major obstacle of the commercialization of the solid oxide fuel cell (SOFC) for distributed power generation. This paper presents a new low cost 10 kW inverter system to overcome this obstacle. The proposed system consists of an isolated DC-DC converter to boost the fuel cell voltage to 400 V DC and a PWM inverter with filter to convert the DC voltage to two split-phase 120 V AC. The DC-DC converter uses phase shifting to control power flow through a transformer with a MOSFET full bridge on the low voltage side and a voltage doubter on the high voltage side. One IPM is used to realize the voltage doubter and the DC-AC inverter. Compared to the existing fuel cell inverter systems, the proposed circuit has low cost, less component count, smaller size, and reduced DC-DC converter peak current. Simulation and experimental results are demonstrated.