The expansion of urban electrical networks, industrial and distribution is increasing demand for systems capable of safely transporting energy, stable and efficient. Within these networks, the level of 69 kV occupies an important position in numerous electrical systems in America, especially in subtransmission networks, industrial facilities, generation plants and large load connection projects.
When a cable 69 kV must be connected directly to a GIS (Gas Insulated Switchgear), cable termination requires specific design. He GIS Terminal for Cable 69 kV allows the transition between the power cable and the GIS equipment while maintaining electrical insulation, control of the electric field and mechanical safety of the system.
A properly designed GIS termination is not simply an accessory installed on the end of the cable. It is a highly important electrical component that must adapt to the cable structure, at the isolation level, to the dimensions of the GIS interface and the operating conditions of the project.
What is a GIS Terminal for Cable 69 kV?
And GIS Terminal for Cable 69 kV is a specialized accessory used to connect a high voltage cable 69 kV with GIS equipment. Its main function is to control the distribution of the electric field in the area where the semiconductor screen of the cable ends and to connect the cable conductor with the internal conductor of the GIS system..
In a conventional XLPE cable, the electric field is distributed relatively uniformly throughout the insulation. However, at the end of the cable there is a discontinuity due to the termination of the semiconductor screen. If this zone is not controlled correctly, Electric field concentrations may occur that increase the risk of partial discharges., insulation aging and electrical failures.
The GIS terminal uses field control elements, Solid insulation and mechanical components designed to provide a stable electrical transition between the cable and the GIS.
Depending on the design, can be used with copper or aluminum cables and with different conductor cross-sections. It can also adapt to different metal screen structures, outer cover and grounding systems.
Why is GIS used in information systems? 69 kV?
GIS allows different electrical equipment to be integrated in a much more compact space than a conventional air-insulated substation.. For this reason, It is especially useful in urban areas, industrial facilities, power plants and projects where available space is limited.
A GIS system can integrate switches, disconnectors, bus bars, current transformers, voltage transformers and other components within a compact system.
Connection via cable 69 kV allows you to install part of the electrical infrastructure underground and directly connect the cable with the GIS.
This offers several advantages:
- Less land occupation.
- Greater protection against environmental pollution.
- Less visual impact.
- Greater flexibility for urban installations.
- Good protection against severe environmental conditions.
- Easy integration with underground networks.
- Suitability for compact substations.
However, The connection between the cable and the GIS requires a high-precision interface. For this reason, GIS terminal must be manufactured according to the specific dimensions and requirements of GIS equipment.
Structure of the GIS Terminal for Cable 69 kV
A GIS terminal for 69 kV is normally composed of several elements that work together to control the electric field and ensure mechanical stability.
driver connector
The connector establishes the electrical connection between the cable conductor and the GIS conductor.
Can be designed for copper or aluminum conductors. Connector geometry should minimize electrical resistance and avoid points of electric field concentration.
Depending on the project, The connection can be made through different mechanical or electrical systems. Connector dimensions must match the interface specified by the GIS manufacturer.
Electric field control element
Control of the electric field is one of the most important functions of the terminal.
When the semiconductor screen of the cable ends, the electric field can be concentrated in that area. The terminal uses specific materials and geometries to redistribute the electric field.
Proper design reduces maximum field strength and decreases the possibility of partial discharges.
insulating body
The insulating body provides the necessary electrical insulation between the high voltage conductor and grounded parts.
The materials used must have good dielectric properties, thermal stability and aging resistance.
In GIS applications, special attention is paid to the compatibility between the terminal insulation system and the insulation system used within the GIS equipment..
Metal screen connection
The metal shield of the cable must be correctly connected to the grounding system.
Depending on network configuration, the screen can use different connection and grounding systems. The design must consider the induced currents, short-circuit currents and voltages that may appear during transients.
GIS interface
The interface with the GIS is one of the most critical parts.
There is not necessarily a single universal geometry for all GIS equipment. 69 kV. For this reason, Before manufacturing the terminal it is necessary to confirm the dimensions of the interface, conductor diameter, mounting position and GIS manufacturer requirements.
Compatibility with XLPE cables 69 kV
XLPE cables are widely used in high voltage networks due to their good electrical properties, thermal and mechanical.
A typical configuration may include:
Conductor + semiconductor driver screen + XLPE insulation + semiconductor screen on insulation + Metal screen + outer cover.
The GIS Terminal for Cable 69 kV must be designed specifically for this structure.
During the installation, cable end preparation is especially important. Insulation surfaces must be kept clean and free of damage.. The removal dimensions of each layer must strictly comply with the manufacturer's instructions.
A small defect on the insulation surface or an incorrect dimension during preparation can significantly affect the electrical behavior of the terminal..
Electric field control
Control of the electric field is essential in any high voltage termination.
At the termination of a cable, Semiconductor screen terminates before XLPE insulation. This geometry generates an area where electric field lines can concentrate.
The terminal must gradually distribute the electric field to avoid excessive values.
For this, different technologies can be used, as geometric elements of field distribution, controlled dielectric constant materials or combined systems.
Selection depends on nominal voltage, cable structure, Terminal design and GIS manufacturer requirements.
electrical tests
Before delivering a GIS Cable Terminal 69 kV, Normally different tests must be carried out to verify its performance.
Among the tests that may be part of the validation program are:
- Withstand voltage test.
- Partial download test.
- Insulation test.
- Thermal tests.
- Short circuit tests when required.
- Screen connection verification.
- Mechanical tests.
- Dimensional inspection.
Specific requirements depend on system design and applicable cable standards, to accessory and GIS equipment.
For high voltage installations it is especially important to verify that the terminal and the cable form a compatible system. The terminal should not be considered as a component independent of the electrical conditions of the cable.
Standards and technical requirements
Standard selection depends on voltage, Cable design and project requirements.
For high voltage cables with extruded insulation, IEC standards related to cables and accessories can be used as reference. Specific standards for gas-insulated switchgear equipment and cable connection interfaces may also apply in GIS systems..
Among the standards that may be relevant are IEC 60840 For certain IEC and extruded insulated cable systems 62271 for high voltage equipment and GIS systems, in addition to the particular specifications of the GIS manufacturer and the electrical company.
In international projects, in addition to IEC, requirements based on IEEE standards may appear, AEIC, ICEA, ANSI or other regional specifications.
For this reason, Before selecting a GIS terminal 69 kV, it is advisable to confirm:
- Maximum system voltage.
- Required withstand voltage.
- Isolation level.
- Conductor type and section.
- Diameter over insulation.
- Metal screen type.
- Cable outer diameter.
- GIS mechanical interface.
- Rated current.
- short circuit current.
- Environmental conditions.
- Screen grounding system.
Installation of the GIS Terminal for Cable 69 kV
Installation must be carried out by specialized personnel and following the manufacturer's specific instructions.
First, the cable is checked and its dimensions correspond to the data used to select the accessory..
The end of the cable is then prepared by carefully removing the cover., the metal screen, the semiconductor screen and the corresponding layers according to the indicated dimensions.
The surface of the XLPE insulation must remain completely clean and without deep marks. Cleaning is particularly important because contaminating particles or debris can affect dielectric performance..
Then the terminal components are installed, including field control system and driver connector. Finally, The connection is made with the GIS and the grounding system is verified.
Once the installation is finished, inspections and tests established by the project must be carried out.
Advantages of a GIS Terminal 69 high quality kV
A properly designed termination can offer long life and high operational stability.
Among its main advantages are:
High electrical reliability.
Proper control of the electric field reduces the risk of partial discharges and failures related to field concentration.
Compact design.
Direct connection with GIS allows you to take advantage of the advantages of compact substations.
Good thermal stability.
Correctly selected materials and connections allow working with high currents for long periods.
Excellent integration.
Terminal can be designed to specific cable and GIS dimensions.
Application in different projects.
Can be used in substations, power plants, industrial facilities, urban networks and infrastructure projects.
How to select a GIS Terminal for Cable 69 kV?
The tension of 69 kV alone is not sufficient to select a terminal.
The first step is to determine the maximum system voltage and insulation conditions. Then the actual dimensions of the cable must be checked.
For example, Two cables with a similar voltage rating may have different insulation diameters due to differences in conductor cross-section, the insulation design or the requirements of each manufacturer.
The GIS interface must also be confirmed.
The main data that must be provided to the manufacturer includes:
| Parameter | Required information |
|---|---|
| System voltage | 69 kV |
| Cable type | XLPE or other extruded insulation |
| Conductor | It covers the aluminum |
| Section | According to project |
| Diameter over insulation | according to cable |
| Metal screen | Copper, aluminum or other |
| Rated current | According to project |
| short circuit current | According to project |
| GIS Type | According to manufacturer |
| GIS interface | Dimensions and standard |
| Installation | Indoor/outdoor |
| Environmental conditions | Temperature, altitude, pollution, etc. |
This information allows you to correctly select the accessory and avoid problems during installation.
Main applications
He GIS Terminal for Cable 69 kV can be used in different sectors.
Electrical substations
One of the most common applications is the connection between underground lines of 69 kV and GIS substations.
Industrial plants
Large industrial facilities require electrical systems capable of transporting large amounts of energy safely.. The cable 69 kV connected via GIS may be a suitable solution for certain installations.
Generation plants
Power plants and renewable generation projects can use 69 kV as part of its evacuation and distribution infrastructure.
Urban networks
In densely populated areas, The underground installation of cables reduces the visual impact and makes better use of the available space.
Modernization projects
GIS systems can also be used to expand or modernize existing facilities when available space is limited..
Why choose a specialized manufacturer?
The manufacture of GIS terminals for 69 kV requires electrical insulation experience, field control, materials, mechanical design and compatibility with high voltage cables.
A specialized manufacturer must be able to provide not only the accessory, but also technical documentation, dimensional plans, installation instructions and technical support.
For international projects, It is also important to have the capacity to manufacture different cable configurations and adapt to customer requirements.
Dosense Cable can develop termination solutions for high voltage cables according to the electrical and mechanical parameters of the project. Configuration can be adapted to different driver sections, GIS screen structures and interface requirements.
Conclusion
He GIS Terminal for Cable 69 kV It is a fundamental component to connect high voltage cables with GIS systems safely and reliably. Its function goes far beyond making a simple electrical connection.: must control the electric field, maintain isolation, withstand thermal and mechanical conditions and provide a compatible interface with GIS equipment.
Correct selection requires joint analysis of the cable, the terminal and the GIS. System voltage, the type and section of the conductor, the diameter on insulation, the metal screen, short circuit current and interface dimensions are essential factors.
For projects of 69 kV, A properly designed and manufactured GIS termination can significantly contribute to security, stability and useful life of the entire electrical installation.