Cylinder Type Test Transformers and Transformer Cascades

Cylinder type test transformer systems are used as high voltage source for dielectric testing of medium and high voltage components as

  • Power and Distribution Transformers
  • Cables, Terminations and Joints
  • Instrument Transformers
  • GIS/GIL and Switchgears
  • Insulators and Bushings

as well as for research, development and education purposes.

Especially for on-site testing, the modular design with two or more stacked small transformer units is bene-ficial and reduces the effort for transportation and erection of the system. They can be mounted on a trailer or transported in a container.

In test laboratories, transformer cascades allow the generation of high voltages with low ground floor requirements. For higher output currents, the stacked transformers can be operated in parallel.

Different kinds of partial discharge measurements like conventional method, non-conventional method with integrated sensors or UHF-method can be applied. With a suitable mains and high voltage filtering, pd-levels of less than 2pC can be achieved.

A suitable selection of the short circuit impedance limits the failure current and external damping elements protect the transformer against transient overvoltages.

Agea-kull designs and builds transformers and transformer cascades tailor made to your requirements. The following list represents therefore only an excerpt of our manufacturing range.

Example of a Test Set including

  • Control and compensation unit
  • Regulating transformer
  • High voltage test transformer
  • Damping impedance
  • Capacitive divider

Agea-kull developed a special kind of cylinder type transformers. Starting with 150kV nominal voltage, they consist of two high voltage windings in series, mounted on an iron core at half potential. The complete active part is fixed in a steel middle potential tank and isolated by use of two reinforced cast resign cylinders.

Electrodes ensure a pd-free operation and protect the transformer in case of overvoltages.


  • Shock-proof design, capable to withstand frequent transportation
  • Protected against overvoltages
  • Symmetrical active-part enables parallel operation of stacked transformers (if equipped with a tertiary winding)
  • High ONAN cooling performance because of steel middle part

Primary compensation reactors reduce the required input current. Cascade internal compensation reactors ensure a linear voltage distribution and reduce the load for the base transformer.

High voltage reactors can be used to extend the load range or to adapt it to the actual test object.

An oil or air insulated column type regulating transformer of the agea-kull ST1-series with special collector design is used to adjust the test voltage.

Either robust relay based control units or modern computer controls can be delivered.

The latter provide the possibility of

  • Automatic sequence testing
  • Data storage and test protocol generation
  • Setting of high voltage trips
  • Adjustable flash detection
Type Voltage
Diameter x Height
TEO10-100 100 0.2 60min On Ø690×870 330
TEO25-150 150 0.53 15/60/6x Ø900×1580 1400
TEO20-200 200 0.25 15/60/6x Ø970×2100 1600
TEO125-250 250 1.0 15/60/5x Ø1450×2500 3600
TEO150-300 300 1.0 15/60/6x Ø1850×2700 4000
TEO200-400 400 1.0 15/60/6x Ø1860×3100 4500

Other voltages, currents, duties and inductance on request!

Enquire Now
By |2021-04-08T09:00:54+00:00March 29th, 2021|Agea-Kull, Laboratory Test Equipment|0 Comments