Grid-connected Fuel Cell Power Generation System Based on Grid Current Feedback and Capacitor Current Active Damping

Grid-connected inverters connect distributed generation and renewable energy sources to the grid. Various filters, including inductor-capacitor-inductor (LCL) filter, are utilized to increase the quality of grid-injected power. In addition to the inherent resonance of the LCL filter, the weak network with variable network impedance leads to instability of the power transmission system. This paper aims to improve the injection power quality of the LCL filter-based grid-connected fuel cell with control based on the grid current feedback and capacitor current active damping. Although active damping can theoretically guarantee the grid-connected passive inverter behavior, the system performance is sensitive to both the current controller phase lag and the variations of the filter parameters. To control these two factors, a suitable phase compensator has been proposed to enhance the passive behavior. In this paper, the control of LCL based grid-tied fuel cell power conditioning system with control based on LCL filter-based utilizing the grid current feedback and capacitor current active damping scheme has been studied, and the passive and stable performance of this system has been evaluated considering the effect of the current regulator phase compensation. The process of systematic design of the control system parameters has been described with necessary details and the passive performance of the grid-connected system has been evaluated. The obtained results for the simulation of the grid-connected fuel cell power optimization system indicate the current injection with very high quality and the passive behavior of the system under variations in the impedance of the weak network.

کلیدواژه ها:

Fuel Cell ، active damping ، Impedance shaping ، Robust Performance ، Inductor-capacitor-inductor filter