Trench Limited is a world leader in power engineering and the design of specialized electrical products- serving customers in the utility and industrial markets around the globe.
Their major product categories include air core reactors, instrument transformers, power quality products, earth fault protection, bushings, line traps, relay communications and protection and control equipment.
Trench's international operations provide fast and reliable support backed by a level of technical expertise and service that is unsurpassed within the industry. The Trench team of companies are dedicated to maintaining industry leadership through continuous improvement and innovation.
Inductive voltage transformers are designed for 72.5kV to 800kV systems and are used to provide voltage for metering and protection applications
Features of Trench voltage transformers include:
Current transformers are available for applications from 72.5kV to 800kV systems, for relaying cores, metering cores are offered in various combinations.
All Trench current transformer designs are based in "top core" or "heat type" construction. Features of this design and construction include:
Combined Instrument Transformers
The Trench combined instrument transformer (CIT) offers the station designer the possibility of being able to accommodate the current transformer and the potential 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.
As with individual current transformers and potential transformers, Trench CITs are available with either oil/paper or SF6 gas dielectric systems.
All operating and construction features are similar to those listed for the individual current transformers and potential transformers.
Trench offers an unparalleled scope of supply with the ability to provide CITs up to 800kV.
Capacitor Voltage Transformers
Capacitor voltage transformer (CVT's) are available for voltage ratings of 69kV - 800kV and are used to provide voltage for metering and protection applications. All CVT's are available with metering or relaying accuracy. Features include:
PLC LINE TRAPS & COUPLING EQUIPMENT
With 50 years of successful field experience, Trench is the recognised world leader in the design and manufacture of air core dry-type inductors for electric utility applications. The unique, custom design approach, along with fully integrated engineering and manufacturing facilities in both North America and Europe have enabled Trench to become the technical leader for high voltage inductors worldwide.
Line Traps for Power Line Carrier (PLC) communication systems represent a significant application segment for high voltage inductors.
Basic Function of Line Traps
Power Line Carrier (PLC) is a common method of Power System Communication, such as teleprotection, voice and data communication, etc. It has developed the reputation of being one of the most economical and reliable forms of communication and versatile in its application. Fig 2 shows a basic PLC system consisting of three distinct components:
- Signal carrying medium (HV transmission line).
- Communication apparatus (transmitters, receivers and associated components).
- Coupling/blocking equipment such as coupling capacitors, line tuners (coupling devices) and Line Traps.
Line Traps are connected in series with HV transmission lines. The main function of the Line Trap is to present a high impedance at the carrier frequency band while introducing negligible impedance at the power frequency. The high impedance limits the attenuation of the carrier signal within the power system by preventing the carrier signal from being:
- Dissipated in the substation.
- Grounded in the event of a fault outside the carrier transmission path.
- Dissipated in a tap or a branch of the main transmission path.
Manufacturers website: www.trenchgroup.com
For expert advice please call: 01608 662295
Product Areas Covered
- Current and voltage transformers
up to 66kV
- Surge arresters
- High speed circuit breakers
- Insulated busbar systems