Reliable power transmission depends on strong and stable connections. In high-voltage systems, one of the most critical interfaces sits between underground cables and gas-insulated switchgear. At this point, the GIS Termination plays a decisive role. At the 132kV level, even minor design or installation issues can lead to serious failures. Therefore, engineers pay close attention to every detail of this component.
As cities continue to expand, substations often move underground or into compact spaces. Consequently, gas-insulated switchgear (GIS) becomes more common. At the same time, utilities demand higher reliability and lower maintenance. For this reason, the demand for high-quality 132kV cable GIS termination solutions continues to grow.
What Is a GIS Termination?
A GIS Termination connects a high-voltage cable to gas-insulated switchgear. It creates a controlled transition from the cable insulation system, usually XLPE, into the SF₆ gas environment inside the GIS.
However, this transition is not simple. The electric field changes significantly at the interface. As a result, engineers must carefully manage electrical stress, maintain insulation performance, and prevent partial discharge.
In practical terms, a GIS termination allows electricity to flow safely and efficiently from the cable into the switchgear. Without this controlled interface, system stability would quickly degrade.
Why 132kV GIS Cable Termination Is Important
In modern power systems, reliability remains the top priority. A failure at the termination point can shut down an entire substation and disrupt supply.
First, GIS terminations support compact substation layouts. Because GIS equipment uses enclosed gas insulation, it requires far less space than traditional air-insulated systems. Therefore, it suits dense urban environments.
Second, they improve operational reliability. The sealed structure protects internal components from dust, moisture, and pollution. In addition, it reduces the impact of environmental conditions.
Moreover, a properly designed 132kV GIS termination minimizes electric stress concentration. As a result, both the cable and the switchgear can operate safely over a longer service life.
Main Components of a 132kV GIS Termination
A GIS termination includes several essential components. Each one contributes to electrical stability and mechanical strength.
Stress Control System
To begin with, the stress control system manages the electric field at the cable end. Without proper control, the field becomes uneven and may cause insulation failure. Therefore, engineers use stress cones or field grading materials to distribute the electric field evenly.
Insulating Body
Next, the insulating body provides the primary dielectric barrier. It separates the high-voltage conductor from the grounded GIS enclosure. Typically, manufacturers use silicone rubber or epoxy resin because these materials offer strong insulation and thermal stability.
Conductor Connection
At the same time, the conductor must connect securely to the GIS terminal. A reliable connection reduces resistance and prevents overheating. In most cases, technicians use compression or bolted connectors to achieve this.
Sealing System
Meanwhile, the sealing system prevents SF₆ gas leakage and blocks moisture ingress. Because GIS depends on stable gas pressure, effective sealing remains essential for long-term performance.
Flange and Housing
Finally, the flange connects the termination to the GIS equipment, while the housing protects internal components from mechanical damage. Together, these parts ensure proper alignment and durability.
Types of GIS Termination for 132kV Cables
Different applications require different designs. Therefore, engineers select the appropriate type based on project conditions.
Dry Type GIS Termination
In many modern substations, dry type terminations are preferred. They use solid insulation materials instead of oil. As a result, they offer easier maintenance and reduced environmental risk.
Oil-Filled GIS Termination
On the other hand, oil-filled terminations provide excellent insulation performance. However, they require careful sealing and regular maintenance. Therefore, they are less common in newer installations.
Plug-In GIS Termination
In addition, plug-in terminations allow faster installation. Because of their modular design, they reduce downtime and improve efficiency, especially in prefabricated GIS systems.
Cable Conductor Size Table (25 mm² to 3000 mm²)
When selecting a GIS Termination, conductor size becomes a key factor. It influences current capacity, thermal behavior, and mechanical compatibility. Therefore, engineers must evaluate cable size carefully.
Conductor Cross-Section and Technical Parameters
| Conductor Size (mm²) | Approx. AWG/MCM | Conductor Diameter (mm) | DC Resistance (Ω/km @20°C) | Typical Current Capacity (A) | Application Level |
|---|---|---|---|---|---|
| 25 | 4 AWG | 5.6 | 0.727 | 150–180 | Control / small load |
| 35 | 2 AWG | 6.7 | 0.524 | 180–220 | Light distribution |
| 50 | 1/0 AWG | 8.0 | 0.387 | 220–270 | Distribution |
| 70 | 2/0 AWG | 9.6 | 0.268 | 260–320 | Medium load |
| 95 | 3/0 AWG | 11.0 | 0.193 | 300–370 | Substation feeder |
| 120 | 4/0 AWG | 12.4 | 0.153 | 340–420 | Medium HV |
| 150 | 300 MCM | 13.9 | 0.124 | 380–470 | Transmission |
| 185 | 350 MCM | 15.5 | 0.099 | 420–520 | Transmission |
| 240 | 500 MCM | 17.5 | 0.075 | 480–600 | 132kV standard |
| 300 | 600 MCM | 19.5 | 0.060 | 550–680 | Main feeder |
| 400 | 800 MCM | 22.6 | 0.047 | 650–800 | Heavy load |
| 500 | 1000 MCM | 25.2 | 0.036 | 750–920 | HV transmission |
| 630 | 1250 MCM | 28.3 | 0.028 | 850–1050 | Common 132kV |
| 800 | 1600 MCM | 31.9 | 0.022 | 1000–1200 | Bulk power |
| 1000 | 2000 MCM | 35.7 | 0.017 | 1150–1400 | Large substations |
| 1200 | 2500 MCM | 39.1 | 0.015 | 1300–1550 | Grid backbone |
| 1400 | — | 42.2 | 0.013 | 1400–1700 | Extra heavy load |
| 1600 | — | 45.2 | 0.011 | 1550–1850 | Large transmission |
| 2000 | — | 50.5 | 0.009 | 1750–2100 | Major grid |
| 2500 | — | 56.4 | 0.007 | 2000–2400 | Ultra high demand |
| 3000 | — | 61.8 | 0.006 | 2200–2600 | Extreme capacity |
How Conductor Size Affects GIS Termination Design
Conductor size directly influences the design of a GIS termination. First, larger conductors require stronger mechanical support. As a result, the termination must handle higher weight and installation stress.
In addition, electric field distribution changes with conductor size. Therefore, engineers must adjust stress control components to maintain uniform field grading.
Furthermore, higher current leads to increased heat generation. Consequently, thermal management becomes more critical for large cross-section cables.
Finally, installation becomes more complex as cable size increases. For example, larger cables require greater bending radius and specialized handling.
Typical Sizes Used in 132kV Systems
In practice, only a limited range of sizes appears frequently. Most utilities prefer standardized options for efficiency and cost control.
Common conductor sizes include:
- 240 mm²
- 300 mm²
- 400 mm²
- 630 mm²
- 800 mm²
- 1000 mm²
Among these, 630 mm² and 800 mm² provide a strong balance between capacity and economic performance. Therefore, they are widely used in transmission projects.
Installation of 132kV GIS Termination
Proper installation determines long-term reliability. For this reason, technicians must follow strict procedures at every stage.
First, they prepare the cable by removing the outer sheath and insulation layers carefully. At this stage, cleanliness is essential.
Next, they install stress control components and insulation parts. Then, they connect the conductor and assemble the termination body.
After that, they mount the termination onto the GIS flange and complete sealing. Finally, engineers perform testing, including partial discharge and high-voltage withstand tests.
Common Challenges and Practical Solutions
Working with GIS terminations presents several challenges. However, proper practices can effectively address them.
Electrical stress concentration may occur if installation lacks precision. Therefore, technicians must follow design guidelines closely.
Moisture ingress can reduce insulation performance. To prevent this, teams must control humidity during installation.
Gas leakage also poses risks. High-quality sealing systems help avoid this issue.
In addition, mechanical misalignment can cause long-term problems. Accurate positioning ensures stable operation.
Advantages of GIS Cable Termination
GIS terminations offer several advantages in modern power systems. First, they support compact designs suitable for urban environments.
Moreover, they operate reliably within sealed systems. As a result, they resist environmental factors such as dust and humidity.
In addition, they require less maintenance compared to traditional systems. Therefore, utilities can reduce operational costs over time.
Applications of 132kV GIS Termination
132kV GIS terminations are widely used across various sectors. For example, they play a key role in:
- Urban underground substations
- Industrial power distribution systems
- Renewable energy grid connections
- Infrastructure projects such as railways and airports
As infrastructure continues to grow, these applications expand further.
132kV Cable GIS Termination manufacturer
A 132kV Cable GIS Termination serves as a critical link in high-voltage transmission systems. It connects cables to gas-insulated switchgear while ensuring electrical safety and reliability.
From component design to conductor size selection, every detail affects performance. Therefore, engineers must evaluate each factor carefully.
As power networks evolve, GIS technology continues to gain importance. Consequently, selecting the right GIS termination solution—and matching it with the appropriate cable size—remains essential for long-term success from 132kV Cable GIS Termination.