Abstract: Certain embodiments involve a modular medium voltage fast charger. The modular medium voltage fast charger can include: (1) a predictive power factor correction (“PFC”) controller (or predictive controller) for series-interleaved multi-cell three-level boost (“SIMCB”) converters, (2) an active neutral point clamped (“NPC”) dual active bridge (“DAB”) modulation scheme to achieve soft switching, (3) an auxiliary capacitor to reduce NPC DAB turn-off voltages, (4) a comprehensive and scalable protection circuit, and (5) a high-isolation pulse transformer with a bobbin for reducing coupling capacitance of the pulse transformer.

Abstract: A cascaded modular multilevel converter for medium-voltage power electronics systems is disclosed. The converter can be used in applications such as an auxiliary power supply for medium-voltage (MV) power electronics system, or a unidirectional SST which powers a home (where very light load conditions are experienced when the home is unoccupied or during the night). Unlike the traditional solutions which use a grid-frequency, bulky, and heavy power transformers, the disclosed converter can operate at higher switching frequencies, weigh less, and provide a higher power density than other approaches. Additionally, the disclosed converter features an internal capacitor voltage balancing and can achieve power factor correction (PFC) using predictive control.

Abstract: In a method for detection of an arc in a current path of a converter arrangement (2) for converting a DC input power to an output power, an arc is detected by sensing the current (4) in the current path by means of a current transformer (11), filtering the current signal (4?) with an analog band pass filter (14), converting the analog filtered current signal (4?) into a digital current signal (4??), determining the harmonic content (19) of the digital current signal (4??) and then deciding whether an arc exists if the harmonic content (19) exceeds a threshold, where the threshold is determined at the beginning as a multiple of the average harmonic content during a certain period of time of the current signal.

Abstract: In a method for detection of an arc in a current path of a converter arrangement (2) for converting a DC input power to an output power, an arc is detected by sensing the current (4) in the current path by means of a current transformer (11), filtering the current signal (4?) with an analog band pass filter (14), converting the analog filtered current signal (4?) into a digital current signal (4??), determining the harmonic content (19) of the digital current signal (4??) and then deciding whether an arc exists if the harmonic content (19) exceeds a threshold, where the threshold is determined at the beginning as a multiple of the average harmonic content during a certain period of time of the current signal.