Dry type transformer FAQ

1. Why is the high-voltage side winding of dry-type transformer installed on the outer layer?
(1) Reduce the requirements for insulation materials and save costs
(2) Reduce the insulation distance from the iron core and reduce the size of the transformer
(3)Easy to operate the tap
2. Why is the voltage regulating tap of the transformer installed on the high voltage side?
(1) The number of turns on the low-voltage side is small and it is very difficult or even impossible to provide taps.
(2) The high voltage side has many turns, making the tap more convenient and more accurate.
3. Generally speaking, the neutral point of a dry-type transformer must be grounded, but why is the neutral point of the excitation transformer not grounded?
If the neutral point of the transformer is not grounded, when the three-phase load is unbalanced or a single-phase grounding occurs, the neutral point will rise. In this case, the neutral line will also be electrified and unsafe, and the grounding current will be very small. , unable to cut off the power supply, the other two voltages to ground will increase, the risk of electric shock will be greater, the equipment may be damaged, and the life of the transformer will be affected. The low-voltage side of the excitation transformer is connected to the AC side power supply of the rotor circuit - the thyristor rectifier circuit. If the AC side power supply of the rotor circuit is grounded, the rotor winding circuit will also be affected. This is not allowed. In addition, if the rotor has any If it is grounded at one point, the generator will not be able to operate stably and will oscillate, or it will lose its magnetism and even affect the life of the generator and the reliability of its operation. Iron core
1. Multiple silicon steel sheets coated with insulating paint are laminated.
2. The clamping of the iron core is mainly achieved by clamps and clamping screws 3. The upper and lower clamps press the core winding through the pull screw or pull plate.
4. The insulation parts of the iron core are clamp insulation, screw insulation or pull plate insulation.