A chattering free Lyapunov function based sliding mode controller applied to single phase series connected PV inverter for grid voltage compensation

Abstract

In this paper, a new type of Lyapunov function based load voltage tracking controller is proposed for series connected PV inverter for grid voltage disturbances compensation. The inverter operates during the day time as an active power compensator as well as load voltage regulator under grid voltage sag, swell or even under normal condition. The compensating voltage provided by the inverter is added vectorially in series with the grid voltage in such a way that the load voltage magnitude is maintained constant along with power flow control facility from the inverter to the load. It is shown by mathematical analysis that the controller gives chattering free sliding mode characteristics. The proposed controller shows faster dynamic response in terms of output voltage tracking capability in comparison with the other reported series connected inverter controllers. The proposed control strategy is relatively simple to implement and provides improved performance as compared to other conventional tracking controllers. Experimental results are provided to show the efficacy of the proposed controller in terms of output voltage tracking capability for the series inverter system. © 2010 IEEE.