Transformer gear: Interpret the key elements of power regulation
In the operation and management of power system, transformer gear is a crucial concept. It is not only directly related to the stability and efficiency of power transmission and distribution, but also plays a key role in the normal operation of various electrical equipment.
The number of gears of the transformer is not fixed, and there are two common types of three and five gears. The tap-changer of a transformer whose primary winding is a star connection is usually divided into three levels; The primary winding is a triangular connection of the transformer, the tap-changer is mostly five stops. Traditionally, first gear is often referred to as the highest gear, and third gear (for a three-speed transformer) or fifth gear (for a five-speed transformer) is considered the lowest gear.
For a three-speed transformer, the voltage regulation range is generally ±5% (based on the rated voltage of the transformer). For example, if the high voltage rated voltage is 10000V, the corresponding voltage of first gear is +5% of the rated voltage, that is, 10500V; The second gear is the rated voltage, which is 10000V; The third stage is -5% of the rated voltage, that is, 9500V. The five-speed transformer, such as some common dry transformers, the gear voltage distribution may be 10500V, 10250V, 10000V, 9750V, 97500V, and 9500V.
The adjustment of transformer gear follows the principle of "high to high profile, low to low profile". When the voltage of the low-voltage network is too high, adjust the high level. When the voltage of the low-voltage network is low, the gear should be lowered. For example, in actual production, if the voltage of the low-voltage grid is measured to be 360V, which is lower than the rated standard of 380V, for the transformer of the three-speed tap-changer, it can be reduced from 1 gear to 2 gear, or from 2 gear to 3 gear, which can increase the voltage of 20V, so that the grid can reach the rated voltage of 380V. For example, when the remote device in the low-voltage power grid is lower than the rated voltage due to the long transmission line and large voltage drop, the power grid voltage can be raised to 400V by adjusting the five-speed tap-changer to ensure the normal operation of the remote device.
Under normal circumstances, when the transformer of the three-speed tap-changer leaves the factory, the tap-changer is set at 2 gear (rated gear); The transformer of the five-speed tap-changer is set in 3 gear (rated gear) at the factory. It is worth noting that when adjusting the transformer gear, be sure to disconnect the transformer high-voltage power supply and low-voltage load, and discharge the transformer high-voltage terminal and low-voltage terminal to ensure safe operation. At the same time, in order to avoid poor contact, it is necessary to repeat the operation several times during the operation to eliminate the oxidation layer and oil film at the high pressure contact point.
Understanding the knowledge of transformer gear is crucial for power engineers, electricians and those engaged in electricity-related work. Reasonable adjustment of the transformer gear can not only ensure the stable operation of the power system, but also effectively improve the efficiency of power use and reduce energy consumption. With the continuous development of power technology, the precise regulation and intelligent management of transformer gear will also become an important research direction in the future power field, helping to build a more reliable and efficient modern power system.