A simple method of estimating the conducted emission from automotive electric power steering (EPS) system

This paper proposes a method to estimate the conducted emission (CE) resulting from the motor of the electric power steering (EPS) system. The proposed method for the CE simulation consists of 3 steps. In order to reduce the computational resources for simulation, firstly, the model for the EPS system is simplified. The ECU model is modified to focus only on the major CE related modules. Moreover, the equivalent circuit including parasitic elements is extracted from a motor with experimental measurement, and then, the parasitic parameters are determined with curve fitting. Finally, the transfer impedance of the EPS system, which includes the simplified ECU and motor, harness cables, gear box and test table, is calculated with the combined circuit and field simulation. As the simulation result is compared with the experimental data, the validation of the CE simulation is demonstrated.