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.