Online Voltage Regulation of Distribution Systems with Disturbance-Action Controllers
Peng Zhang, Baosen Zhang
TL;DR
The paper tackles online voltage regulation in distribution systems with high penetration of inverter-based DERs under time-varying loads and communications delays. It develops a disturbance-action controller that leverages the closed-loop system response to map disturbances to control actions, updating parameters online within a linearized model $x_{t+1}=B u_t+w_t$. The main theoretical contributions are stability guarantees and robustness bounds (Theorems 5–8) that account for model inaccuracy and latency, along with demonstrations that history information and load generalization improve performance. Practically, the approach offers a robust, real-time voltage-control method that can tolerate modeling errors and delays and scales to networks with significant PV variability.
Abstract
Inverter-based distributed energy resources facilitate the advanced voltage control algorithms in the online setting with the flexibility in both active and reactive power injections. A key challenge is to continuously track the time-varying global optima with the robustness against dynamics inaccuracy and communication delay. In this paper, we introduce the disturbance-action controller by novelly formulating the voltage drop from loads as the system disturbance. The controller alternatively generates the control input and updates the parameters based on the interactions with grids. Under the linearized power flow model, we provide stability conditions of the control policy and the performance degradation to model inaccuracy. The simulation results on the radial distribution networks show the effectiveness of proposed controller under fluctuating loads and significant improvement on the robustness to these challenges. Furthermore, the ability of incorporating history information and generalization to various loads are demonstrated through extensive experiments on the parameter sensitivity.