Clean MW Multi-pulse Rectification with Less Active Harmonic Filter Effort

Abstract:
The energy transition requires high power 3-phase rectification concepts with low grid interference. Although medium voltage active converters are proposed in the literature, passive rectification is still widely used in high power applications due to its simple design and robustness. However, such passive rectification concepts require filtering due to the emission limits for current harmonics defined in national and international standards and connection rules. In the currently proposed topologies, the active filters must be rated for approximately 30 % of the apparent power of the rectifier. This paper discusses the application and the control of a single low voltage 3-phase active filter together with a 12-pulse MW rectifier which allows to rate the active filter for only 13 % of the apparent power. Furthermore, this paper addresses the latest emission requirements for MW multi-pulsed systems in the context of current standards and connection rules.