Z-Transform Models for the Analysis of Electromagnetic Transients in Transformers and Rotating Machines Windings

High voltage power equipment with winding structures such as transformers, HV motors, and generators are important for the analysis of high frequency electromagnetic transients in electrical power systems. Conventional models of such equipment, for example the leakage inductance model, are only suitable for low frequency transients. A Z-transform model has been developed to simulate transformer, HV motor, and generator stator windings at higher frequencies. The new model covers a wide frequency range, which is more accurate and meaningful. It has many applications such as lightning protection and insulation coordination of substations and the circuit design of impulse voltage generator for transformer tests. The model can easily be implemented in EMTP programs.