There are two voltage regulation methods for transformers, one is no-load voltage regulation, also called non-excitation voltage regulation; the other is on-load voltage regulation. But no matter which way, the voltage regulation is based on the principle of changing the ratio, but the operating conditions and methods are different.
Transformers are the main reason for using alternating current instead of direct current in large power distribution systems. That's because when you send a lot of power over a long distance, sending power in the form of high voltage and low current is more effective.
The voltage of the power system changes frequently due to changes in the load. The actual voltage of the power grid generally cannot be exactly equal to the rated voltage, and the difference between the actual voltage and the rated voltage is the voltage offset. The existence of voltage offset is inevitable, but it is required that this offset cannot be too large, otherwise the power supply quality cannot be guaranteed.
As a tie transformer between two power grids, it is often necessary to adjust the voltage of the transformer to adjust the load distribution between the networks to ensure that the voltage deviation is always within the specified range. Therefore, to ensure the normal operation of the transformer, it is necessary to adjust the voltage of the transformer.
The transformer only works under alternating current. That's because the change in the magnetic field generated by the primary coil induces a voltage in the secondary coil. In order to generate a changing magnetic field, the voltage applied to the primary coil must constantly change.
Since DC is a stable fixed voltage, a fixed magnetic field is generated, which does not induce a voltage in the secondary coil.
The transformer transfers power from the primary coil to the secondary coil(The main purpose of the transformer). Since the power must remain constant, if the voltage increases, the current must decrease. Likewise, if the voltage decreases, the current must increase.
Transformer shifting is to change the voltage by changing the taps on the high-voltage side of the transformer. The rules for transformer shifting are: high and high, low, and low. Insufficient voltage, in order to reach the rated voltage of the appliance, it is necessary to adjust the transformer gear and adjust the gear according to the relevant load situation.