PSPICE model of an open-circuit DC shunt machine

Abstract

Computer models are used to replicate the essential performance features of a physical element using convenient modeling and simulation programs. Within SPICE, an acronym for the Simulation Program with Integrated-Circuit Emphasis, a model for the twin-depencence of the machine's open circuit generated e.m.f. on the time-independent flux and machine speed has not been investigated. This paper describes a steady state model of an open circuit DC shunt machine using PSPICE, the PC version of SPICE packaged within the OrCAD programming environment. The model is based on characterization of the generated e.m.f.as field current dependent polymial voltage source whose coeffecients are generated within MATHCAD by applying a linear regression fit on a set of experimental laboratory data points. The simulation results are displayed using the inbuilt graphic postprocessor within PSPICE called PROBE. This results show good replicative model validity within the laboratory range of exciting currents used in the simulative.