what is a load tap changer

What is a Load Tap Changer?Electricity is an essential requirement for various applications, ranging from household appliances to industrial machines. To ensure that electricity is available consistently, transformers are an essential part of the electrical distribution system. They are used to change the voltage of electricity from one level to another, making it suitable for different uses. A Load Tap Changer (LTC) is a device used to regulate the output voltage of transformers.

The Function of Load Tap Changer

Voltage regulation is the primary function of a transformer. However, transformers are engineered to have a fixed voltage ratio. It means that the transformer's output voltage remains constant, even if the input voltage varies. A Load Tap Changer helps to regulate the transformer's output voltage and provides an adjustable output voltage to its end-users. The LTC achieves this by varying the turns ratio of the transformer with the help of different tapping positions on the high voltage winding.

The Types of Load Tap Changers

Load Tap Changers are classified into two types, electrical and mechanical. Electrical LTCs use electronic circuitry to sense the transformer's output voltage, compare it with the desired output voltage, and accordingly adjust the transformer's turns ratio. A mechanical LTC, on the other hand, relies on mechanical movement to switch between different tapping positions. Mechanically operated LTCs are more common in distribution transformers than electrical LTCs.

Design of Load Tap Changer

A typical Load Tap Changer consists of a diverter switch and a selector switch. The selector switch controls the movement of the diverter switch across different tapping positions in the transformer's high-voltage winding. The diverter switch then connects the tapped winding to the low-voltage winding. LTCs are designed to be robust, reliable, and provide a smooth voltage transition between two different tapping positions. They also have a life expectancy of around 30 years.

Conclusion

In conclusion, Load Tap Changers play a pivotal role in managing the voltage output of distribution transformers. They enable the transformer to supply a stable voltage to the end-users by adjusting the turns ratio of the high-voltage winding as per the varying output voltage requirements. LTCs come in different types and designs, but they all serve the same purpose- voltage adjustment. Electric utility companies cannot emphasize enough the importance of LTCs in electrical distribution systems.