World’s largest adjustable shunt reactor with VACUTAP® VR® in Turkey


It was by no means a run-of-the-mill order for the transformer manufacturer Alstom Grid in Turkey. The world’s largest adjustable shunt reactor with 400 kV / 250 MVar was constructed for the national electric supply company TEIAS. Alstom Grid developed the extensive specifications for the gigantic shunt reactor together with TEIAS. This investment became necessary due to the increasing capacitive load caused by the cabling of the high-voltage networks in process in the region around Istanbul.

The resulting increase in the supply voltage can now be effectively balanced with the shunt reactor. As far as on-load tap-changers were concerned, the VACUTAP® VR® was used to ensure proven technology and ultimate quality from MR. The VACUTAP® VR® ensure maintenance-free operation with up to 300,000 switching operations, through vacuum technology, thus increasing the availability of the transformer. In addition, the operating costs are reduced to a minimum and the frequency of maintenance is considerably decreased.

Why shunt reactors?

High-voltage networks are subjected to heavy daily and seasonal fluctuations – depending on energy consumption. In several regions, this dynamic is intensified as a result of the rapid growth of metropolitan areas and not least due to the subsidization of renewable energies, which put additional strain on the networks with heavily fluctuating energy production. The regulated shunt reactor can be a technical and economically effective solution in this regard.

Shunt reactors are usually installed at the end of a line or placed at specific points along the line and do improve transmission and distribution network operation in various utilization profiles and network operating states – the result is a reduction in line losses and an improved voltage profile.

Regulated shunt reactors are the most compact and cost-efficient solution for the compensation of high magnitude reactive power in transmission networks. They are used to improve the network stability and for the continuous voltage regulation in off-peak operation and line idle times.

Advantages at a glance:

  • Greater degree of network reliability
  • Constant voltage
  • Improved voltage profile
  • Reduction in line losses
  • Reduction of system costs and the required space