Active power electronic transformer based on modular building blocks

Electric vehicle multiport fast charger based on the concept of active power electronic transformer

“…The power devices, gate drivers, co applications can result in reduced systems [2]. Current PEBBs incl link capacitor, as shown in Figur simple independent low level converter (PEBB1), a renewable EV battery charger (PEBB3).…”

“…, (2) where N TR is the transformer transfer ratio, N 2 is the number of windings of the transformer renewable energy port, N 3 is the number of windings of the transformer storage port, U 2 is the DC-link voltage of the renewable energy port, U 3 is the storage port battery voltage, f s is the switching frequency and L 23 is the multiport transformer leakage inductance. Phase angle φ (rad) between the voltage waveforms U 2 and U 3 can be written as: ,…”

“…One possibility is to replace the conventional low frequency transformer by a medium or high frequency one and add appropriate power electronic converters [1] to the input and output of the transformer. The resulting active power electronic transformer (APET) complies with all requirements of the smart grid concept [2]. The problems in the fast charging stations of the state-of-the art electric vehicle are: low frequency sub-station transformer; additional energy losses due to many energy conversion states; separate isolation transformers in each charging converter; low intermediate DC-bus voltage [3].…”

“…The proposed multiport topology [4], [5] based on the APET has many beneficial features: power control (active and reactive power); voltage control (compensation of voltage sags and peaks); current control (short-circuit current limitation); integration of distributed generation (MPP tracking, energy storage) [2]. Multiport topology eliminates separate isolation transformers, lowers the number of energy conversion stages, weight, complexity, cost and energy losses during EV battery charging.…”