Dynamic modeling and stability analysis of power networks using dq0 transformations with a unified reference frame

The dq0 reference frame has become popular for modeling and control of traditional electric machines and small power sources. However, its widespread use for modeling and analysis of large-scale, general power systems is still a pending issue. One problem that arises when considering dq0 models is that they are typically based on local reference frames, and therefore linking different models is not straightforward. In this paper we propose to approach this problem by modeling the network and its components using a dq0 transformation that is based on a unified reference frame. We demonstrate this idea on the basis of synchronous machines and photovoltaic generators, and we also establish a dq0-based dynamic model of a transmission network. The resulting models all use a unified reference frame, and therefore can be directly linked to each other in simulation and analytically. The paper is accompanied by a free software package (Levron, Y. and Belikov, J. Toolbox for Modeling and Analysis of Power Networks in the DQ0 Reference Frame. 2016. www.mathworks.com/matlabcentral/fileexchange/58702) that constructs the proposed dynamic models and provides tools for dynamic simulations and stability studies based on dq0 quantities.