Non-iterative Optimization Algorithm for Active Distribution Grids Considering Uncertainty of Feeder Parameters

TL;DR

This paper introduces a non-iterative, real-time optimization algorithm for active distribution grids with uncertain parameters, enabling fast and accurate tracking of optimal solutions without iterative procedures.

Contribution

It proposes a novel one-step calculation method combining prediction and Newton-based correction, effective even with uncertain network models.

Findings

Fast online tracking of optimal solutions demonstrated in simulations

Algorithm performs well without requiring network model accuracy

Capable of handling time-varying system conditions

Abstract

To cope with fast-fluctuating distributed energy resources (DERs) and uncontrolled loads, this paper formulates a time-varying optimization problem for distribution grids with DERs and develops a novel non-iterative algorithm to track the optimal solutions. Different from existing methods, the proposed approach does not require iterations during the sampling interval. It only needs to perform a single one-step calculation at each interval to obtain the evolution of the optimal trajectory, which demonstrates fast calculation and online-tracking capability with an asymptotically vanishing error. Specifically, the designed approach contains two terms: a prediction term tracking the change in the optimal solution based on the time-varying nature of system power, and a correction term pushing the solution toward the optimum based on Newton's method. Moreover, the proposed algorithm can be applied in the absence of an accurate network model by leveraging voltage measurements to identify the true voltage sensitivity parameters. Simulations for an illustrative distribution network are provided to validate the approach.