Regarding the wiring group of transformers

The winding connection group of a transformer is a way of indicating the combination of the connections for its primary and secondary windings；   There are two common wiring methods for transformer windings, namely “triangle wiring” and “star wiring”” ； In the connection groups of transformers, “D” denotes a delta connection, “Yn” denotes a star connection with a neutral wire, Y represents a star connection, and n indicates the presence of a neutral wire ； “11” indicates that the line voltage Uab on the secondary side of the transformer lags behind the line voltage UAB on the primary side by 330 degrees (or leads by 30 degrees).   The notation for the connection group of a transformer is as follows: uppercase letters indicate the wiring configuration of the primary side, while lowercase letters indicate that of the secondary side. Y (or y) denotes star connection, while D (or d) denotes delta connection. Numbers are expressed in clock notation to indicate the phase relationship between the line voltages on the primary and secondary sides. The phasor of the primary side line voltage acts as the minute hand, fixed at the 12 o’clock position on the clock, while the phasor of the secondary side line voltage acts as the hour hand.    “Yn, d11”, where 11 indicates that when the phase voltage on the primary side points to the 12 o’clock position on the clock, the phase voltage on the secondary side is at the 11 o’clock position on the clock. In other words, the line voltage Uab on the secondary side lags the line voltage UAB on the primary side by 330 degrees (or leads it by 30 degrees).   When the two windings of a transformer are combined, 4 wiring connections are formed: “Y, y”, “D, y”, “Y, d” and “D, d”. Our country only uses “Y, y” and “Y, d”. Since there are two types of Y connections: those with a neutral wire and those without, no additional symbol is used for connections without a neutral wire; whereas for those with a neutral wire, the letter \"n\" is added after the letter \"Y\". n indicates that the neutral point has a lead wire. Yn0 wiring connection: UAB and uab coincide, with both the hour and minute hands pointing at 12. “In the new wiring categories, 12” is represented by “0”.

Number of coil turns determines tube voltage magnitude; connection configuration determines tube voltage direction