Affinely Adjustable Robust Volt/Var Control for Distribution Systems with High PV Penetration

We propose two novel two-stage Volt/Var control schemes based on the affinely adjustable robust counterpart (AARC) methodology, to mitigate the over-voltage issues caused by integration of photovoltaic panels into distribution systems. To cope with different grid code requirements, our first approach formulates the unused capacity of residential inverters to provide reactive power support based on the real power deviation, while the second approach formulates them based on voltage magnitude deviation. In the first stage of both schemes, we make central measurements throughout the network to determine a linear function, mapping the operating point deviations to the reactive power of inverters. In the second stage, the local controllers use the provided linear functions to determine the required reactive power to keep the voltages within the safe limits. Unlike similar approaches, voltage limit constraints are directly incorporated into the AARC problem, preventing the second stage controllers from unnecessarily use of reactive powers. We compare the performance of our schemes using a Monte-Carlo simulation with four other existing techniques on a real-world 27-bus and the IEEE 906-bus LV feeders. Our simulations show that our approaches decrease the real power loss, reactive power usage, and line congestion compared to the other Volt/Var control schemes.