Active Filtering of DC Ripple Currents Between Converter and Low-Resistive DC Load

Abstract:
The switching operations of a voltage source inverter with its DC-link coupled to low-resistive and low-inductive components like lithium-ion batteries cause DC ripple currents. Those currents are unintentional, cause additional losses and can even damage components exposed to it. This paper introduces a power electronic control element consisting of fast switching silicon carbide (SiC) MOSFETs beeing able to compensate those ripple currents. Simulations results prove the effectiveness of the chosen approach and promise advantages for the design by lowering packaging dimensions of heavy, costly passive filters and thus the corresponding losses. A test bench was also setup for validation of simulation results. Measurements converge with simulations and prove the theoretical approach.