Refined modeling of voltage source converter and distributed optimization for AC/DC grids with pumped storage

Abstract

Accurate voltage source converter (VSC) modeling is critical for reliable optimal operation of hybrid AC/DC grids, while centralized methods suffer from poor scalability and privacy issues. This paper proposes a distributed optimization method for the coordinated optimal operation of AC/DC hybrid systems with pumped storage, based on an adaptive Broyden-family-parameterized Augmented Lagrangian based Alternating Direction Inexact Newton (ALADIN) algorithm, denoted as AB-ALADIN. This method achieves system-wide optimal resource operation with pumped storage as a critical flexibility resource. A refined VSC model is developed to accurately depict converter losses and operation constraints. The framework employs AB-ALADIN algorithm that dynamically adjusts its parameters to balance global and local convergence. Numerical simulations demonstrate that the proposed method has advantages in convergence speed and solution accuracy. The refined VSC model effectively reduces the relative cost deviation between optimized dispatch and practical power flow verification from 4.63% to 0.13% and eliminates all voltage violations. This work offers a viable approach for the optimal operation of hybrid AC/DC grids with pumped storage.