Primal-Dual Distributed Control of Residential Thermal Loads for Voltage Regulation of Distribution Systems with High PV Penetration

This paper presents a distributed control strategy of building thermal loads to enable voltage regulation of distribution networks with high photovoltaic (PV) penetration. A model predictive control approach is adopted that relies on linearized power flow and building thermal models to capture the relationship between residential loads, PV generation and feeder voltage. A primal-dual algorithm with Tikhonov regularization is proposed to solve the control problem in a distributed manner across different households. Performance of the strategy was demonstrated through a simulation study of an IEEE 33-bus test distribution network serving a prototype residential community. The strategy was proved to be effective in regulating feeder voltage within prescribed limits with additional benefits of line loss reduction; the opportunity cost for voltage regulation was found to be less than 1 % for the cases study.