Input current controlled DC interconnection converter for fuel cell systems

Fuel cells are a remarkably efficient energy generator that also protect the global environment. NTT is developing a fuel cell energy system that supplies generated electrical energy to telecommunications equipment. It is a cogeneration system; the heat energy recovered is used to cool the telecommunications equipment. In a DC interconnection system, along with the commercial AC power, the fuel cell output is fed to the telecommunications equipment through a converter. This paper describes a control method for a new DC interconnection converter and DC interconnection characteristics. The new converter controls its input current to the fuel cell rated current at maximum and can operate stably even when the fuel cell output decreases. Good DC interconnection characteristics can be obtained in the steady state and the transient state