Inverter Control for Three-Phase Grid Connected Fuel Cell Power System

In this paper the topology of the grid-connected fuel cell power system and the performances of the front-end three-phase power inverter are presented. The proposed topology has been designed and benefits of the small plastic film dc link capacitor thanks to the power balance control of the entire power conditioning system, and thus replacing the bulk dc link electrolytic capacitor. By using the load feedforward control the input reference of the current is changed with load and thus a better transient response is obtained. The increase in the power response of the dc-ac inverter makes it possible to reduce the size of the DC link capacitor by maintaining the systems´ stability. The final power conditioning system has the following advantages: independent control of the active and reactive powers, minimize harmonic current distortion offering a nearly unity power factor operation, operation capability, dc link voltage regulation, fast disturbance compensation capability, high reliability, and low cost. The proposed control was successfully implemented by the author on quasi direct ac-ac converter and based on the Matlab/Simulink software the simulation test has been performed for the modified topology. The performances of the grid power inverter are shown. The comparative results between the proposed topology and the ac-ac converter are reported.