ABB has launched the world's first on-load tap changer (OLTC) with a less complex winding design for rated currents of up to 1,800 ampere (A). This design does not require forced current splitting in the transformer windings, which allows reduced manufacturing time and increased reliability for the transformer, contributing to overall greater power network stability. The rating of 1,800 A is the highest in the world for this design.
Tap changers are essential parts of transformers, ensuring they operate reliably and safely. An OLTC is a device that regulates voltage in power systems to help keep them stable. A tap changer adjusts the turn ratio between the windings in a power transformer, which is essential to keep network voltage stable under variable load conditions. Tap changers are also widely used in industrial transformers to deal with variable network loads in rectifier and furnace applications.
"Achieving high power ratings for a transformer winding that is less complex to produce will help reduce the total manufacturing time for large power transformers without compromising reliability," said Manish Gupta, head of ABB's Insulation and Components for Transformers business, a part of the company's Power Grids division. "ABB is continually addressing technology trends and market challenges in the transformer industry with innovative products that meet or surpass the demanding requirements of today's transformer customers."
Vacuum interrupter technology is at the heart of this new generation of tap changers, in which electrical arcs are extinguished in a vacuum rather than oil. The end result is lower life cycle costs, reduced maintenance, and longer operation as a result of radical reduction in contact wear.
The OLTC rated at up to 1,800 A was developed from a design that uses three parallel vacuum interrupters instead of one. ABB is at the forefront of OLTC technology development, having developed a complete portfolio of vacuum OLTCs for both high-speed resistor and reactance type, and this unit is the latest example.
