A teardown of a 3kVA rated 19" 2U form factor UPS for server racks, the APC Smart-UPS X SMX3000, a run down of the controller and power electronics of the system.
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The inverter and battery charger uses 7 IGBTs in a peculiar configuration. The IGBT IRGP4063D is special, its ultrafast soft recovery diode being of the same current rating as the IGBT itself. The IRGP4063D IGBT is rated for 600 V and 48 A current with a Vce(on) voltage drop of 1.65V. APC utilizes a novel switching scheme, where the IGBT diodes are used for battery charging. Once it has to deliver power to the outputs, the IGBTs are driven another way to act as a inverter. This brings down the number of parts needed. The roles of battery charger and UPS are never used at the same time.
