EMI Measurement Design for Linear Traction Motor and Experimental Results Analyses

Electromagnetic environment in the underground has a fatal impact on the reliability and safety of signalling equipments. This paper introduces the ideal differential-mode and common-mode model of linear induction motor (LIM) used in urban rail transit system, and points out the potential EMI problem. For the designed laboratory model, the authors designed the EMI measurement scheme referring to the rotary induction motor regulations. Then the common-mode disturbances and radiation emission experimental results are presented and analyzed. The experimental curves demonstrate that these disturbances are mostly generated by the pulse width modulated (PWM) inverter and the values can be met with CLASS-A standard. The experimental results indicate that the performance of the model of linear traction motor is favorable.