ADN_Modelica: An Open Source Sequence-Phase Coupled Frame Program for Active Distribution Network Steady State Analysis

Abstract

Abstract:Open source software such as OpenDSS has given a lot of help to distribution network researchers and educators. With high penetration of distributed renewable energy resources into distribution network, tradition distribution steady state analysis software such as OpenDSS is faced with difficulty in handling distributed generators. Three-phase distributed generators are often modeled in sequence frame while unbalanced distribution network are usually modeled in phase frame. So a load flow in sequence-phase coupled frame is proposed to handle models described in both frames. Voltage controlled DGs which are difficult to cope with in OpenDSS are handled in proposed program. The steady state analysis platform is programmed with open source Modelica language and the main aim of this paper is to introduce an open source platform for active distribution network steady analysis include load flow and short circuit analysis which can be easily adopted and improved by other educators and researchers.

Research on three‐phase optimal power flow for distribution networks based on constant Hessian matrix

“…The constraints (5) -(9) consider the coupling characteristics of three-phase powers. They are different from the steady-state model in [22] which does not consider sequence control under unbalanced condition. The equations involving DG are either linear or quadratic -this guarantees a constant Hessian matrix in the OPF.…”

“…This introduces a virtual loss to the objective function which will reduce the error brought by rounding-off. At present, the quadratic penalty function [20] and the Gaussian penalty function [13] are two widely used penalty functions, as given by (22) and 23, respectively…”