Distributed cooperative voltage control of wind farms based on consensus protocol

Abstract

The increasing penetration level of wind power brings a number of challenges to power system operations. Voltage/reactive power control is an important task of a wind farm to fulfill the grid requirements and avoid the cascading trip faults of wind turbines (WTs). To address this issue, a distributed cooperative voltage control strategy is proposed for wind farms based on the consensus protocol in this paper. In the proposed voltage control scheme, a droop-based local controller is adopted for the primary voltage control based on the local measurements. A consensus-based distributed secondary voltage controller is proposed, aiming to regulate the voltages within the feasible range while optimizing reactive power sharing among the reactive power sources using the local and neighboring information. The controller parameters are determined by the closed-loop system stability analysis using a linearized model. A wind farm with 20 WTs was used for the case study to validate the proposed control scheme under both steady-state and fault-ride-through (FRT) conditions. Moreover, the robustness against a communication link failure and plug-and-play capability of the proposed voltage controller were tested.