Interfacing for Universal Multi-Machine System Modeling In an Electromagnetic Transients Program

This paper presents a new predictive approach to the intertacing of rotating electric machinery for the transient analysis of universal multi-machine systems, i.e., the machines contained in the system may be of different types-such as induction, synchronous, doubly-fed and direct-current machines, Basic considerations and theory underlying the approach are covered. The corresponding interfacing scheme is shown to be crucial to certain machine types. The approach has been successfully implemented to the Universal Machine module of the well-known Electromagnetic Transients Program (EMTP). Application to test cases involving rather severe transient conditions demonstrates the lack of any interfacing-error amplification. Gain in computational efficiency by application of the proposed interfacing, rather than interfacing as based on phase compensation, is significant.