Robust Policy-Based Distributed Voltage Control Provided by PV-Battery Inverters

Various approaches that combine local, centralized and distributed voltage control techniques have been proposed in literature. These techniques suffer from different problems. Local voltage control systems suffer from degraded voltage regulation; centralized voltage control systems have poor reliability and scalability; distributed voltage control systems are complex to implement. To solve these issues, this paper proposes a novel distributed voltage control system enabled by robust linear policies. The proposed voltage control consists of two phases. In the day-ahead phase, the voltage control problem is formulated as a chance-constrained stochastic optimization problem, where the control actions are expressed as linear function of the uncertain households' active power consumption and photovoltaic power. The paper applies robust optimization to construct a tractable approximation to the chance constraints. In the real-time phase, the photovoltaic-battery systems communicate with each other and apply the robust policies to regulate voltages within limits. Simulations over 36500 scenarios are used to demonstrate the robustness of the proposed voltage control system.