Impedance and Emission Optimization of Low-Voltage DC Motors for EMC Compliance

This paper presents a method to automatically generate high-frequency (HF) generic electrical models for low-voltage dc motors. A software model generator creates an electrical circuit which reproduces both HF impedance and emission spectrum of any common dc motor within a frequency range from 150 kHz to 1 GHz. The impedance and emission spectrum are calculated from construction and material parameters like armature geometry and winding wire radius only; no measurements are required. This makes it possible to perform sensitivity analyses of motor construction parameters and minimize the motor´s electromagnetic interference early in its design phase before samples and measurements are available.