An efficient modeling method for EMT analysis of large scale AC/DC power systems

In order to overcome the limitation of transient stability analysis (TSA) which is unable to describe the non-fundamental or asymmetry characteristics of AC/DC power systems, electromagnetic transient modeling method with high efficiency is urgent for large scale power systems. According to actual HVDC converters, this paper first simplifies the valve group model as well as the transmission line model to reduce computing resources. The modeling method suitable for text conversion based fast modeling technology is then introduced. The model is easy to initialize and improves the calculation speed. Finally, simulations of a modified system of the 2-areas 4-machines grid shows the effectiveness and accuracy of the simplified HVDC system model as well as the user-defined generator models. An electromagnetic transient modeling (EMT) procedure is demonstrated by the China Southern Power Grid equivalent system and suggestions are put forward in order to improve the accuracy of the TSA.