Power System Electromagnetic Transient Modeling And Simulation

Power systems electromagnetic transient digital computing is an important part of the electric power network transient analysis. With increasing system security requirements, researches on electromagnetic transient areas become more and more importance, in which, the most important is analysis and calculation after switching action or system disturbances resulting in the over-voltage, over current, and the insulation coordination. However, with deeper research and degree of being practical, the scope of the study of electromagnetic transient field hasn't only been greatly widened, but also highlighted its importance. No matter what type of research, an accurate mathematical model of components is essential. In this paper, based on study in electromagnetic transients'simulation theory of lines, focus on the power electronic switch device and the prominent nonlinear characteristics devices, such as high impedance ground fault, the superconducting current limiter components. After fully analysis on component features, a mathematical model is established. In particular, consider the following aspects:1. switching element in the existing fixed step electromagnetic transient simulation program will appear the numerical oscillati-on, and the elimination method is proposed; 2. improving the existing high impedance ground fault model, using six branches to represent the randomness of the arc characters of high impedance ground fault; 3. chosen superconducting current limiter as tycipal nonlinear elements, through the detailed analysis of the current limiter principle and core saturation characteristics, using piecewise linearization to build the saturated iron core superconducting current limiter mathematical model. Then with the support of the detail mathematical model, the relevant components of the simulation are proposed, including:1. HVDC-light and double-fed induction wind turbine simulation, especially in when wind farm connect to grid, the HVDC-light can suppress the electromagnetic transient process; 2. six arc branches modeling the high impedance ground fault simulation, experimental results show that the model can meet the high impedance ground fault characteristics; 3. based on the actual measurement information on the 220kV saturable iron core superconductor fault current limiter, simulate SICSFCL in PSCAD/EMTDC.