MULTI-LEVEL INVERTER USING 3-PHASE TRANSFORMERS AND COMMON-ARM

摘要

A multi-level inverter using three-phase transformers and a common arm is provided to reduce the number of switching elements by using the common arm to determine polarity of an H-bridge. A multi-level inverter includes a plurality of low frequency transformers(100), a switching unit(200), and a control unit. Output terminals of the low frequency transformers are connected in series for multi-level output. The switching unit switches the low frequency transformers and is composed of H-bridge cells connected to a DC power supply in parallel. The control unit controls the switching unit. The low frequency transformers are three-phase transformers. The output terminals of the three-phase transformers are connected in series for each phase, and the three phases are Delta connected.