Optimum Equivalent Models of Multi-Source Systems for the Study of Electromagnetic Signatures and Radiated Emissions From Electric Drives

An optimum equivalent electric machine model for 3-D finite element (3DFE) simulation and evaluation of radiated electromagnetic field emissions in a multi-machine environment is presented. A typical example of such systems includes electric motors and cable runs electric drives. Initially, the detailed geometrical model of the machine was simulated in a 3DFE quasi-static electromagnetic domain. An optimum equivalent model was created using an optimization process based upon the difference between the observed electric and magnetic far fields from both the detailed geometrical and the equivalent models. The equivalent model was validated in several examples. The computed electromagnetic signature results from the equivalent model show acceptable accuracy as compared with the detailed geometrical model of the machine. The equivalent machine model was obtained with significant reduction in computation time needed for the evaluation of the radiated fields. The proposed model can be used as an effective method for the simulation of signatures and radiated electromagnetic field emissions from electric drives in computationally intensive environments.