Synchrophasor-Based Auxiliary Controller to Enhance the Voltage Stability of a Distribution System with High Renewable Energy Penetration

Wind energy is highly location-dependent. Many desirable wind resources in North America are located in rural areas without direct access to the transmission grid. By connecting megawatt-scale wind turbines to the distribution system, the cost of building transmission facilities can be avoided and wind power supplied to consumers can be greatly increased; however, integrating megawatt-scale wind turbines on distribution feeders will impact the distribution feeder stability, especially voltage stability. Distributed wind turbine generators (WTGs) have the capability to aid in grid stability if equipped with appropriate controllers, but few investigations are focusing on this. This paper investigates the potential of using real-time measurements from distribution phasor measurement units for a new WTG control algorithm to stabilize the voltage deviation of a distribution feeder. This paper proposes a novel auxiliary coordinated-control approach based on a support vector machine (SVM) predictor and a multiple-input and multiple-output model predictive control on linear time-invariant and linear time-variant systems. The voltage condition of the distribution system is predicted by the SVM classifier using synchrophasor measurement data. The controllers equipped on WTGs are triggered by the prediction results. The IEEE 13-bus distribution system with WTGs is used to validate and evaluate the proposed auxiliary control approach.