1, when the transformer shifts, adjusting the tap-changer will not increase the reactive power of the system, but only change the reactive power distribution, which will increase the bus voltage of 10kV, which will lead to the reduction of the high voltage side voltage of the main transformer. The tap-changer of transformer should be based on high-voltage bus voltage, and then take into account the low-voltage side. If the voltage on the high voltage side of the main transformer is not high, the tap-changer is useless, which is not conducive to system stability.

2. Transformer is a device that changes AC voltage by electromagnetic induction principle. Its main components are primary coil, secondary coil and iron core (magnetic core). The main functions are: voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization (magnetic saturation transformer) and so on. According to the purpose, it can be divided into: power transformer and special transformer (electric furnace transformer, rectifier transformer, power frequency test transformer, voltage regulator, mine transformer, audio transformer, intermediate frequency transformer, high frequency transformer, impulse transformer, instrument transformer, electronic transformer, reactor, transformer, etc. ). t is usually used as the beginning of circuit symbols. Examples: T0 1, T20 1, etc.