THREE-PHASE STEP-DOWN TYPE AC VOLTAGE CONTROL UNIT

摘要

PURPOSE: A three-phase step-down type AC voltage control unit is provided to control linearly the AC output power applied to a load terminal by stepping down the three-phase input voltages. CONSTITUTION: A three-phase step-down type AC voltage control unit includes the first transformer(TR1), the second transformer(TR2), the third transformer(TR3), and a controller. The secondary part of the first transformer(TR1) is connected between R-phase AC power as an input and U-phase AC power as an output. The secondary part of the second transformer(TR2) is connected between S-phase AC power as the input and V-phase AC power as the output. The secondary part of the third transformer(TR3) is connected between T-phase AC power as the input and W-phase AC power as the output. The controller is connected to the primary parts of the first to the third transformers(TR1,TR2,TR3) in order to apply the voltages to the primary parts of the first to the third transformers(TR1,TR2,TR3).