Introduce: The combined instrument transformer offers the station designer the ability of being able to accommodate the current transformer and the voltage transformer in one free-standing unit. This allows optimum use of substation space while yielding cost savings by elimination of one set of mounting pads and support structures. In addition, installation time is greatly reduced.
Combined Instrument Transformers are commonly used in the electrical power industry when the space auf the substation is limited and are available with either oil or SF6 dielectric systems.
Main Features
1.Excellent insulation stress control using a fine graded bushing (less weight, less oil volume, increase safety and reliability)
2.Maintenance free
3.Safety (strong limitation of internal overpressure, shielded secondary windings, hermetically sealed)
4.Low reactance primary permits high short circuit currents and high primary current
5.Perfect transient performance
6.Suitable for line discharging
7.Essentially unaffected by stray external magnetic fields
8.Excellent seismic performance due to optimized designs (low weight) and porcelain (cementing) and flanges (welding)
9.Exclusive use of corrosion resistant materials (aluminum tank and head)
Technical parameters:
1.Available from 72.5 kV up to 300 kV
2.Only one foundation required by combining CT and VT in one housing
3.High quality mineral oil insulation, PCB free, biological decomposition
4.Porcelain or Composite insulator
5.Hermetically sealed stainless steel metallic bellows
6.Rated primary currents up to 5000 A
7.Rated secondary current from 0,5 A to 5 A
8.Maintenance free during a long lifetime of more than 30 years
9.High accuracy CT (0.1 %) over wide extended range of primary current
10.Uniformly distributed secondary windings guarantee accurate transformation of primary currents
11.Explosion resistant by
12.High reliability insulation system
13.Fine graded bushing
14.Bushing tube and connection to withstand high short circuit current