| 摘要 |
PROBLEM TO BE SOLVED: To balance the voltage constantly by connecting the input part of a three-phase four-wire system with one terminal of a DC coil having the other terminal connected with the output part of the three-phase four-wire system and connecting the other terminal of a preceding DC coil with one terminal of a shunt coil having the other terminal connected with the neutral of three- phase four-wire system. SOLUTION: First series coils 21A, 21B and 21C are in-phase with second shunt coils 25A, 25B and 25C and a current flowing through some phase flows into all three phases. The first series coils 21A, 21B and 21C and second series coils 22A, 22B and 22C have same number of turns and different winding direction. First shunt coils 24A, 24B and 24C and the second shunt coils 25A, 25B and 25C have same number of turns and different winding direction. According to the arrangement, fluxes are canceled each other to produce a current balance action and since the return path of flux can be shared among respective phases, the power distribution transformer can be reduced in size. |
