Patent ID: 6804127
Filing Date: 2004-10-12
Classification: H02M

Abstract:
An AC/DC/AC power converter, comprising:A rectifier having diodes, anode of one said diode connected to cathode of another said diode to form a phase leg, the middle node of said diode leg serves to accepts one input power line, the free cathode end of all said diode legs are tied as a positive terminal and free anodes of all legs are similarly tied together to serve as the negative terminal; An inverter having switching semiconductors, with a free-wheeling diode connected across each said switching semiconductor to form a bi-directional current carrying switch-diode module, two said modules to form a leg, the middle node of said leg serves as an output terminal, free nodes of all legs with diode cathode to tie together to accept DC positive bus, free nodes of all legs with diode anode to tie together as negative terminal; A DC link section with an inductor, a capacitor and a precharge means in series, said capacitor is constructed with film or ceramic materials, said capacitor terminals serve as DC output for said inverter; A control means supplying signals capable of isolating said capacitor from input and output of said converter; Whereby the capacitance of said capacitor in said DC link section is reduced and capacitor construction is simplified for compactness, endurance and reliability of said converter; The over-voltage transient is protected by fast reaction of said control means.