Abstract
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Integration of wind energy sources into the distribution grid affects the voltage profile that could be stabilized through the grid reinforcement or limiting the active power injection. This paper presents a control strategy to regulate the voltage at point of common coupling (PCC) through reactive power exchange to the grid. The reactive power capability of the grid-connected hybrid multilevel converter is based on the voltage sensitivity of the distribution grid at PCC. A hybrid five-level multilevel converter referred as flying capacitor (FC) based active-neutral-point-clamped (ANPC) converter is considered. It is an arrangement of a three-level ANPC converter and a two-level cell. Also, a control strategy is proposed to regulate the FCs voltages of the grid-connected hybrid multilevel converter at their required values. The proposed FC control strategy provides extra freedom to regulate the dc-link capacitor voltages with dc-offset injection technique. Simulation studies demonstrate the performance of the proposed control strategies for the system considered. © 2012 IEEE.