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Pressurized air cables can be directly connected to overhead line cables, allowing the line to continue underground and encapsulated. This enables lines to be routed under settlements or nature reserves without impacting the environment.

Entire overhead line connections from switchgear to switchgear can also be replaced with pressurized air cables – installed in protective tubes, microtunnels, or existing tunnels.

Advantages of Pressurized Air Cables

• Simplified Route Planning & Faster Approval Process
  More flexible planning, no restrictions due to masts or overhead lines, no impact on residents.

• Reduced Energy Losses
  The lower resistance reduces losses per meter by a factor of 2 to 10 compared to overhead lines. Additionally, underground connections are usually shorter than above-ground routes (e.g., a tunnel through a mountain instead of a zigzag path over it).

• Noiseless - no Corona Discharges
  No disruptive humming or buzzing, as occurs with high-voltage overhead lines.

• Minimal Magnetic Fields
  The metallic enclosures keep the external magnetic field minimal – ideal for urban areas and sensitive environments.

• Higher Acceptance & Aesthetic Enhancement
  Underground installation avoids visible impacts on the landscape and urban environment, fostering a positive public perception.

• Lower Maintenance Effort & Weather-resistant
  The robust construction reduces maintenance costs and ensures higher operational safety. Underground installation protects against weather influences and vegetation growth.

• Protection Against Vandalism and Terrorism
  Underground installation provides excellent protection against vandalism or terrorism, thereby safeguarding this critical infrastructure.

• Higher Transmission Capacity – no Voltage Increases Required
  The capacity limit of overhead lines can often only be sufficiently increased by raising the voltage (e.g., from 220 kV to 380 kV). The use of pressurized air cables enables significantly higher transmission capacities without the need for voltage increases, making grid expansion more cost-effective and faster.

Cost comparison: Pressurized air cables vs. Overhead lines

While the investment costs per meter are higher, the significantly lower operational losses and reduced maintenance effort lead to lower lifetime costs for pressurized air cables. They are therefore the more economical solution in the long run.

Pressurized air cables have the same function as traditional medium- and high-voltage cables and can replace them. This reduces transmission losses, eliminates the need for parallel cable systems, and improves fire protection.

Advantages of Using Pressurized Air Cables

• Better Technical Performance
  Pressurized air cables offer higher nominal currents of up to 5000 A per cable for maximum efficiency. Additionally, they allow for temporary overload capability during operation.

• Lower Losses
  The larger conductor cross-sections of pressurized air cables reduce transmission losses by a factor of 2-3 compared to XLPE cables.

• Reduced Construction Costs & No Joints
  The innovative flange connection and lower heat losses allow for more compact installation with reduced space requirements, eliminating the need for complex joint connections. No concrete duct block is required either.

• Optimized Fire Protection
  The thick metallic casing provides superior safety in fire incidents and against arc faults, ensuring maximum operational safety. This makes pressurized air cables ideal for installation in existing tunnels.

• Easier Transport & Installation
  Lightweight aluminum pipe construction with low transport weight and small transport units optimizes construction logistics, especially at hard-to-reach construction sites.

• No Reactive Power Comepnsation up to 60 km
  Traditional underground cables require reactive power compensation from approximately 20 km in length, leading to additional costs and losses. With pressurized air cables, compensation is only needed from around 60 km. This eliminates additional costs for shorter distances and further reduces operational losses.

Cost comparison: Pressurized air cables vs. XLPE cables

For nominal currents above 1000 A, pressurized air cables have comparable investment costs to XLPE cables. The higher the nominal current, the more competitive pressurized air cables become. Lower operational losses reduce lifetime costs.

Pressurized air cables have the same basic design as existing GIS and GIL products and can therefore replace them in all applications. The environmentally harmful and banned PFAS gases used in previous applications (SF6 gas, perfluoronitrile gas mixtures) are replaced by environmentally neutral pressurized air. Additionally, costs, assembly effort, and sealing performance are optimized by replacing complex bolted flanges with a bolt-free flange system with double sealing.

Advantages of Using Pressurized Air Cables

• No Use of SF6 Gas and PFAS Gas Mixtures
  Hivoduct pressurized air cables offer the same performance parameters as SF6 GIS and GIL but without climate-damaging PFAS gases. Pressurized air cables use pressurized air as an insulating medium – an environmentally friendly and future-proof solution. Grid operators save on taxes and declaration efforts related to PFAS gases.

• Maximum Operational Safety
  Pressurized air is environmentally neutral and breathable, posing no issues if released in enclosed spaces or tunnels. In contrast, SF6 has an extremely high greenhouse potential and remains in the atmosphere for decades when released.

• Allows very Long Installations
  Gas-insulated lines require large amounts of insulating gas, especially for long installations and high voltages. It would be irresponsible to use such large quantities of potent greenhouse gases. Pressurized air is the only viable insulating gas option for long lines.

• Optimized Sealing System and Gas Handling Processes
  Pressurized air cables have significantly fewer sealing points and feature a double-seal system at each sealing point to ensure permanent containment of the initially filled compressed air. The pressurized air can be refilled directly from a standard air cylinder without special equipment or vented into the environment for maintenance.

• Better Public and Regulatory Acceptance
  Governments and society are increasingly focusing on sustainable technologies. Pressurized air cables enhance the environmental image of companies and ensure compliance with future environmental regulations.

• Reduction of PFAS Gases in Existing GIS Installations
  Pressurized air cables can replace parts of existing GIS installations using a simple adapter. This allows for the replacement of a significant portion of SF6 gas in busbars or outgoing lines, even if it continues to be used in circuit breakers.

• Optional Monitoring and Refilling System
  Pressurized air cables can be equipped with a pressure monitoring system that continuously monitors the pressure in each gas chamber. An automatic refilling system for potential leaks can be advantageous for hard-to-access installations.

Cost comparison: Pressurized air cables vs. GIS busbars

Pressurized air cables have lower investment costs per meter than GIS or GIL with the same ratings. This is due to lower product costs through optimized design, reduced assembly effort, and lower gas handling costs..

Busbars are used when the nominal currents for individual cable systems are too high or when tight spaces require small bending radii. Pressurized air cables are ideal for high nominal current requirements and can be routed around corners without bending radii thanks to angle pieces.

In addition to the nominal currents listed in the table above, we offer conductor options for high-current applications up to 6000 A across all products.

Advantages of Using Pressurized Air Cables as Busbars

• High Current-Carrying Capacity and Low Losses
  Pressurized air cables ensure maximum power transmission with minimal losses. Nominal currents up to 2500 A are possible with standard conductors. Currents up to 5000 A can be selected for any voltage level.

• No Bending Radii and No Joints
  Pressurized air cables enable flexible installation without joints or restrictions due to bending radii. This simplifies installation and significantly reduces space requirements.

• Integrated Grounding
  With pressurized air cables, grounding is already integrated into the housing, eliminating the need for additional grounding installations. The housing can carry the full nominal and short-circuit current, effectively shielding the external magnetic field.

• Optimal Fire Protection & High Arc Fault Resistance
  Pressurized air cables feature a robust metallic casing, providing superior protection against fires and arc faults. This makes them particularly suitable for critical industrial environments and existing tunnels with parallel infrastructure.

• Comprehensive Component Portfolio for Flexible Layouts
  Pressurized air cables offer a diverse component portfolio for every model series, allowing flexibility for any application. Key components include adjustable angles, flexible connections, T-pieces, longitudinal compensators, and interfaces to other high-voltage components such as cables, transformers, GIS, or overhead lines.

• Single-Phase or Three-Phase Encapsulation
  Pressurized air cables can be designed with single-phase or three-phase encapsulation. This allows for space and current-carrying capacity to be optimized according to the specific application.

Cost comparison: Pressurized air cables vs. Busbars

Pressurized air cables are an economically attractive alternative to conventional busbars. Significant cost advantages arise, particularly in complex layouts or very long installations. The higher the nominal current, the more competitive pressurized air cables become.

Wall bushings are short high-voltage connections that transfer power from one side of a wall to the other. Pressurized air cables are ideal for this application, as their metallic casing can be connected to the building and grounding system while allowing for very high nominal currents. The use of pressurized air as an insulating medium also reduces the installation's weight.

Advantages of Using Pressurized Air Cables

• High Current-Carrying Capacity & Low Losses
  Large continuous currents of up to 5000 A can be transmitted with minimal heat dissipation losses.

• Integrated Grounding
  Grounding is already integrated into the housing, saving space and costs without compromising safety.

• Optimal Fire Protection & High Arc Fault Resistance
  The metallic casing provides superior protection against fires and arc faults, minimizing the risk of damage and operational disruptions.

• Lightweight Design
  The air insulation in the connection and bushings reduces overall weight, decreasing the need for support structures and fastenings.

• Optional Montoring System
  Pressurized air cables can be equipped with a pressure monitoring system that continuously monitors the pressure in each gas chamber.

Cost Comparison: Pressurized Air Cables vs. Traditional Wall Bushings

Pressurized air cables are a cost-effective alternative to conventional wall bushings. The higher the nominal current, the more competitive pressurized air cables become.

The rapid advancements in rocket technology are making space stations in orbit, on the Moon, and on Mars a reality. Pressurized air cables can be insulated with a vacuum instead of compressed air, making them ideal for space applications. Additionally, their low transport weight, robust metallic casing for radiation protection, and high nominal currents to eliminate the need for heavy transformers make them optimal for such environments.

Advantages of Using Pressurized Air Cables

• Vacuum as an Insulating Medium
  The basic design of pressurized air cables can also use a vacuum instead of compressed air in the insulation gap. Vacuum is naturally present in space and has no weight.

• Lightweight Design
  Minimizing transport weight is essential for space applications, as all materials must be delivered via rockets. The vacuum insulation, combined with the minimalist design of pressurized air cables, helps reduce weight.
• High Transmission Capacity - MW at Low Voltage
  Space stations will generate power in the megawatt range through photovoltaic systems. For distribution at low voltage, cables rated for 1000 A – 5000 A are required. Pressurized air cables with vacuum insulation can be designed for such currents.

• Integrated Grounding
  Grounding is already integrated into the housing, saving space and costs without compromising safety.

• Optimal Fire Protection & High Arc Fault Resistance
  The metallic, grounded casing provides superior protection against fires and arc faults, which is crucial for survival in space stations.

• Radiation Resistance & Longevity
  Background radiation in space degrades and destroys plastics used in traditional cable insulation. Pressurized air cables are composed of 99% aluminum, which remains stable in such environments.

• No Need for Transformers
  Transformers are heavy and complex devices used to convert electrical energy between different voltage levels. If power distribution at low voltage is feasible, transformers are no longer necessary.

• Suitable for Both DC and AC Applications
  Pressurized air cables with vacuum insulation can be designed for both DC and AC applications. Both types of power will be required in space stations.