Provably robust online voltage control for distribution networks with line parameter estimation

Abstract

This paper introduces an online robust control algorithm, which regulates the voltage of a balanced power distribution network without any prior knowledge of the line parameter values. To model the underlying distribution network, we adopt the recently introduced (parameterized) lossy distribution flow equations, which allow us to characterize network losses. Our algorithm includes two components that work in tandem. The first component iteratively estimates the line parameters (i.e., network resistance and reactance) that are consistent with available voltage measurements, while the second component regulates the network voltage within the prescribed safe limit despite the uncertainty in the line parameter estimates. We theoretically prove that our algorithm estimates consistent line parameters and also certify that the number of times when the voltage violates the safe limits are bounded. Simulation studies on benchmark IEEE distribution networks verify that the proposed algorithm effectively estimates line parameters and stabilizes network voltage.