An Interval Power Flow in AC/DC Hybrid System with Uncertainty

Abstract

A unified AC/DC interval power flow (IPF) method based on affine arithmetic (AA) in AC/DC hybrid network with uncertainty, which includes load fluctuation, intermittence of renewable energy sources, is proposed in this paper, whose purpose is to quantitatively assess the influence of uncertain data on AC/DC power flow (PF). Firstly, a unified PF of AC/DC system with voltage source converters (VSCs) is established. Then the IPF in AC/DC system is converted to nonlinear optimization problems based on AA under rectangular coordinate. The constraints are constructed by characteristic equations of AC/DC system, which is composed of AC grids, VSCs and DC grid. The objective functions are obtained by solution formulas of PF accordingly, which mainly includes bus voltage magnitude. Finally, the extended IEEE-9 and IEEE-30 AC/DC system are tested, whose results are compared with those simulated by Monte Carlo. The comparison results demonstrate that the proposed method is effective and superior.