Transformers are devices that are used for stepping up or stepping down the voltage of an electrical supply while relaying power from the supply stations to the communities or industries.

When the commercial sectors are drawing full power or the residential sector’s load increases the voltage supplied by the secondary or the power transformers can drop and become unstable. This is where the necessity of a tap position indicator comes in.

A tap position indicator is a device that can show the deflection between the desired output voltage and the current output voltage of the windings of the secondary transformer. This can be then used to increase the efficiency of the transformer. The functioning of the tap position indicator for power transformers is discussed in detail below.

Working Principle

Microprocessor-based electronic devices are used for monitoring and modifying the load tap changer(LTC) in a power transformer.

The  TPI incorporates the functions of multiple devices that were previously used for controlling the transformers LTC, such as selector switches and manual control switches, among others.  For this reason, the general complexity of the device due to the interlinking parts can be avoided and maintenance of the device becomes easier.

The TPI is equipped with signaling output contacts, an indication of the tap position via a current loop output, dry contacts input for remote command and an RS485 serial port, allowing complete data acquisition and total remote control of the LTC.

The equipment was totally designed and tested for operating in the harsh conditions found in electric substations, such as surges, impulses, electromagnetic interference and extreme temperatures.

Features:

• The device has the capability to automatically calibrate the cable resistance between itself and the potentiometric position transmitter, thereby increasing distances with small cables.
• With a tap indicator like this, the available faults in the wire relay systems and other devices can be found out easily.
• The resistance value is programmable according to the load tap changer in the transformer. On a device like this, there are options directly to manually or remote select tasks through dry contacts. The same can also be used for raising or lowering the resistance and other values directly.
• The whole device provides customizability options and has a four output relay that indicates the status of the device and also gives information on the alarms.
• Microcontrollers in the device are used to constantly provide feedback and detect failures within the device. There are no mechanical parts in the device for any kind of calibration.

Equitel Power is an online transformer accessories and transformer spare parts dealer in Kolkata. The online store provides such indicators from the industry-standard brands at very affordable prices. With proper customer support and delivery services, they can really help professionals get good products for the smooth functioning of their transformers.