Ultra-Low Losses SiC-Based Active Damper for Industrial Power Systems: Mitigating Harmonic Distortion and Maximizing Harmonic Power Recovery

Wideband harmonics and undamped resonances have become problems of major concern for industrial end-users in the last time. Although passive dampers are the simplest solution to combat the mentioned problems, passive dampers convert the harmonic active power ($P_{H}$) they absorb to heat, leading to energy waste. Conversely, active dampers not only reduce harmonic distortion and suppress resonances but can also perform harmonic power recovery. In effect, harmonic power recovery implies transforming the $P_{H}$ absorbed into fundamental active power that is injected back into the power system. This paper introduces a mathematical model that describes the mechanisms and necessary conditions of harmonic power recovery within an active damper. The model shows that a substantial amount of $P_{H}$ can be recovered only if the active damper's power losses are significantly smaller than the $P_{H}$ absorbed. Consequently, this paper presents the implementation of an ultra-low losses 82 kVA active damper based on SiC MOSFETs which recovers around 80% of the $P_{H}$ absorbed. Moreover, a comparative experimental evaluation was carried out between the proposed active damper and an IGBT-based active damper. The comparison shows that the amount of harmonic power recovered can be increased by a factor of four using the SiC-based active damper.