Coordinated Voltage Control in Unbalanced Distribution Networks with Two-stage Distributionally Robust Chance-constrained Receding Horizon Control

The integration of increasing share of renewable based distributed generation in distribution networks brings great challenges to voltage control. To address this issue, this paper presents a two-stage distributionally robust chance-constrained receding horizon control algorithm. In the proposed method, the distributionally robust chance-constrained reformulation of chance-constrained voltage control is derived, which is not only accurate, but also computationally efficient. Rather than perfect knowledge about the uncertainty associated with renewable generation, the proposed method only requires partial information of the underlying probability distribution. In addition, the mechanical voltage regulation devices and the DG inverters are controlled in two stages, considering their different characteristics in voltage control. By taking into account both the current and forecasted renewable generation, the proposed method utilizes receding horizon control to determine the control actions of voltage regulation devices. The effectiveness of the proposed method is demonstrated by case studies on unbalanced IEEE-123 bus system.