Fully decentralized multiarea reactive power optimization considering practical regulation constraints of devices

Reactive power optimization is essentially finding the optimal power flow for optimizing the voltage profile and power flow in the steady state. Considering that the operation of devices is restricted by their service lifetimes and regulations, dynamic reactive power optimization (DRPO) is formulated as a mixed-integer nonlinear programming problem considering the practical regulation constraints of devices. To preserve the control independence and information privacy of the distributed subnetworks, a three-stage programming approach is proposed to achieve a fully decentralized solution to the DRPO problem of the multiarea power system. In addition to incorporating optimality condition decomposition, the decentralized DRPO method includes three stages for addressing the difficulty in handling the discrete variables, and it can achieve a fully distributed solution for the multiarea DRPO problem, with only minor boundary information to be exchanged. A forward-backward-pass dynamic programming approach with computational complexity of polynomial order is utilized to solve the stepwise fitting problem. The simulation results for three test systems demonstrate that the proposed decentralized method can obtain a high-quality solution in a decentralized manner with promising computation performance considering the practical regulation constraints.