High-frequency parasitic effects in electric drives with long cables

In this work, the inverter is considered the source for HF parasitic effects and therefore thoroughly investigated and modeled. Also, more complex simulation models for cable and motor are developed and analyzed, together with their parameterization methods. A good compromise between model complexity and parameterization simplicity is followed. Next, all individual parts are connected together in an overall simulation model, to reflect the HF phenomena from inverter to motor. The investigated simulation models are verified with measurements at a real setup, a process that allows the iterative improvement of the simulation models. Finally, methods for reduction of overvoltage and common-mode ground current, regarding the improvement of inverter control and the use of inverter-output / motor-input filters are investigated using the complete simulation model and the measurements at the real setup. In the last part of the presented work, an unconventional converter topology is investigated for application with long cables, namely the Quasi-Resonant (QR) DC-link converter. Two major objectives are followed: the main issue here is the motor-friendly characteristic, leading to significant improvement of the motor operation; the secondary objective is to achieve a good efficiency compared to hard-switched converters with inverter-output filters. Finally, both objectives are validated with measurement results.