A low cost resonant snubber inverter for uninterruptible power supply application

A soft switching single-phase inverter designed for an uninterruptible power supply (UPS) was studied. Although the load of an UPS may not be inductive, the typical output LC filter of the inverter of the UPS provides an inductive load for the inverter of the UPS, which maintain the load current nearly constant as the inductive load of a motor. This load characteristic makes it possible to apply similar soft switching techniques for motor drive inverter to UPS inverter. when soft switching techniques used in DC-DC converter, soft switching increases the switching frequency by reducing the switching loss, and the increased frequency can dramatically shrink the size of the output filter of the converter. Another main advantage of the soft switching technique is the reduced electromagnetic interference (EMI).