The SmartActiveTransformer suits any compact station

The on-load tap changer was specially developed and optimally integrated with the transformer tank in which the switches operate in special vacuum cells to exclude the possibility of oil contamination, thus no second oil vessel is required for the circuit.

The innovative design enables the SmartActiveTransformer to correspond with the dimensions of local network transformers, and it is easily integrated with conventional compact stations. In connection with the control cabinets, it also includes all of the functions that are required for self-sufficient voltage regulation.

 Regulator function

  • voltage regulation on the low-voltage bus bar
  • three-phase voltage measurement
  • automatic, remote and manual modes
  • higher/lower operation
  • Ethernet and RS232 interfaces
  • IEC 60870-5-101; IEC 60780-5-104 and IEC 61850 control system protocols
  • powder-coated sheet metal housing
  • IP54 degree of protection


  • step motor
  • duration less than 1 second per cycle

Load switching function

  • on-load tap changer based on the reactor principle
  • electric arcs are quenched in specially developed vacuum switch tubes
  • space-saving integration
  • maintenance-free for the lifetime of the transformer (up to 700,000 cycles)
  • regulation on the upper voltage side