BLDC Motor and Drive Low Frequency Conducted RFI Simulation for Automotive Applications 2003-01-0869

In considering automotive conducted RFI specifications applicable to motors and their associated drives, simulation of conducted radio frequency emissions in the range from 150 kHz to 1 MHz is an area of interest from the product design perspective for several reasons. Traditionally, suppression of conducted noise in this frequency range of interest has been achieved through the use of bulk capacitance. These capacitors not only limit the lifetime of the motor, but they also consume valuable space within the motor, as well as add cost motor. The selection of bulk noise suppression elements has in the past been predominately made through trial and error “brute force” methods. The following paper presents a method whereby low frequency conducted RFI emissions can be simulated through the use of a high fidelity virtual motor and drive model, as well as a virtual spectrum analyzer.