SNUBBER CIRCUIT FOR DIODE CLAMP TYPE 3-LEVEL INVERTER AND METHOD FOR PREVENTING OVER VOLTAGE THEREOF, CAPABLE OF IMPROVING VOLTAGE UNBALANCE IN OFF STATE OF SWITCHING DEVICES

摘要

PURPOSE: A snubber circuit for a diode clamp type 3-level inverter and a method for preventing an excessive voltage thereof are provided to reduce snubber loss during snubber operation as reducing the over voltage generated during turn-off of all switching devices. ;CONSTITUTION: A first snubber capacitor(Cs) has an anode connected to a collector of a first switching device. A first snubber diode has an anode connected to a cathode of the first snubber capacitor. One end of a first snubber resistor is connected to the cathode of the first snubber capacitor and the anode of the first snubber diode. The other end of the first snubber resistor is connected to an anode of the first clamp diode, a cathode of the second clamp diode and a negative port of a load.;COPYRIGHT KIPO 2011