20150069955 | SYMMETRIC-TYPE UPS POWER SYSTEM BASED ON A NINE-PHASE PHASE-SHIFTING AUTOTRANSFORMER - A symmetric-type UPS power system based on a nine-phase phase-shifting autotransformer includes a three-phase AC power input terminal, a three-phase AC power output terminal, a nine-phase phase-shift autotransformer, a synchronized control device for controlling output of a three-phase inverter, a power-frequency isolation transformer and three circuits of output devices; wherein the three-phase AC input terminal of the nine-phase phase-shifting autotransformer is connected to the three-phase AC power input terminal, each circuit of the output devices includes a zero-sequence suppression commutating inductor, a three-phase six-pulse rectifier, a three-phase inverter and a filter inductor which are connected with each other in sequence, each circuit of the zero-sequence suppression commutating inductor is connected to the three-phase AC output terminal of the phase-shifting autotransformer, each circuit of the filter inductor is connected to the input terminal of the power-frequency isolation transformer. | 03-12-2015 |