Automated Filter Optimization for High-Voltage Cable Harness based on Circuit Simulations for Conducted Emissions Prediction

EMI suppression in vehicles cable harnesses is commonly realized by passive EMI filters. Rising battery voltages, faster semiconductor switches and the use of unshielded DC-cables requires larger filters. In addition, it is necessary being able to estimate the size of the EMI-filter in an early stage of development, when no measurements of the conducted emissions exist yet. To solve this problem, an automated filter optimization tool based on simulations for the prediction of conducted common-mode emissions (CE) is presented. The simulation model requires only a little information of the inverter which is accessible at an early stage of development. The accuracy of the model is good enough to predict the CE up to 30 MHz. In combination with a differential evolution algorithm for the optimization of the filters components, a fast estimation of the required space can be achieved.