Working Principle:

A three-phase to two-phase balanced phase-changing transformer with YN or D, d connection, realizing the electric quantity conversion of a three-phase symmetrical power system into a two-phase power system in a balanced manner, characterized in that the three-phase side is connected with three equal-turn coils in a star-shaped YN or triangle-shaped D connection; the two-phase side is connected in a "star" or d connection, consisting of four coils, and the corresponding three-phase side phase sequence can also be found by mirroring the "heart" of the wiring diagram, the two-phase side has·a common output point c, the triangle vertex adjacent to the common point constitutes an output port, and the other output port is constituted by the head end of the extended side and the common point, the two output ports have equal voltage vector amplitudes, the phase difference is 90" electrical angle, the number of turns of each side of the triangle is equal, the number of turns from the tap position to the head end of the coil with a tap side' is 1 1/5 times the number of turns of the side and 1/v5 times the number of turns of the side respectively, and the two parts of the turns can also be separately wound into two independent coils, the tap and the extended tail end are The number of turns of the extended side coil is equal to 1/3 times the number of turns of the triangle side. and the transformer core is an ordinary three-column, four-column or five-column structure.

Advantage:

The utility model has a neutral point with high current grounding on the three-phase side that the high-voltage power system hopes to meet, which can reduce the insulation level of the high-voltage winding; the two-phase side also has a common point for grounding, which is particularly suitable for the railway station BT power supply method(BT power supply equipment is simple, the voltage level is low, and the operation is economical); the design and manufacturing difficulty is low, the number of coils is small, which reduces the coll insulation air path, and there is no need to artificially increase the air path distance due to impedance matching, and the actual volume of the product is the smallest the theoretical structure capacity of the transformer is also the smallest except for Scott and Kubler. In addition, because the cross section of the wire involved in the operation is larger than that of other wiring modes when the single arm is in asymmetrical operation, the load loss under this working condition is reduced, and the operating cost of the transformer can be reduced, Therefore, the utility model is an invention with great social value.