The main benefits of using high-voltage transmission include:

• Reduced Power Loss: As explained above, higher voltage reduces the current, which in turn dramatically minimizes energy loss from resistance along the transmission lines.

• Cost Efficiency: Lower current allows for the use of thinner and lighter conductors and smaller transmission towers, which significantly reduces the cost of materials and infrastructure for long-distance projects.

• Improved Voltage Stability: High-voltage systems maintain a more stable voltage level throughout the line, ensuring that the power delivered to end-users is consistent and reliable.

• Increased Capacity: Higher voltage allows for the transmission of more power through the same conductors, increasing the overall capacity of the grid without adding new lines.

Most power grids use high-voltage alternating current (AC) because it is easy to step up or step down the voltage using transformers, which are relatively simple and inexpensive. This flexibility makes AC ideal for a widespread, interconnected grid.

However, high-voltage direct current (HVDC) transmission is increasingly used for very long distances (hundreds of kilometers) or for undersea cables. HVDC lines have lower transmission losses over extreme lengths and avoid certain complex electrical phenomena inherent to AC systems, such as inductive and capacitive losses. While voltage conversion for HVDC is more complex and expensive, its superior efficiency for specific applications makes it a key technology for the future of power transmission. Our company provides a wide array of equipment for both AC and HVDC projects, including specialized tools for cable stringing and laying.

Managing high-voltage power lines requires a comprehensive range of specialized equipment and tools to ensure safety, efficiency, and reliable operation. This includes:

• Conductors and Insulators: To carry the high-voltage current and prevent it from arcing to the ground or towers.

• Tension Stringing Equipment: Machines and tools to install the conductors on overhead towers without damaging them.

• Substation Equipment: Transformers, switchgear, and circuit breakers to step up the voltage for transmission and then step it down for distribution.

• Safety and Grounding Tools: Devices for protecting personnel during construction, maintenance, and repair work.

Our company, Ningbo Changshi, manufactures and exports this full spectrum of equipment and tools, providing a one-stop supply for all your overhead and underground power line projects.

Regular electrical maintenance is crucial for power line projects to ensure safety, reliability, and cost-effectiveness. Maintenance is a proactive approach that helps identify and fix potential issues before they cause system failures, power outages, or safety hazards. This is particularly important for overhead and underground power line infrastructure, which is constantly exposed to environmental stressors like weather, temperature fluctuations, and aging. By using high-quality equipment and conducting regular checks, you can prevent dangerous situations and ensure a consistent power supply.

A preventive maintenance program offers multiple benefits that directly impact the efficiency and longevity of electrical systems:

• Enhanced Safety: Regular inspections and repairs mitigate the risks of electric shocks, fires, and equipment failures. A well-maintained system protects workers, equipment, and the public.

• Reduced Downtime and Outages: By addressing minor issues early, you can prevent major breakdowns that lead to costly and disruptive power outages. This ensures a reliable and uninterrupted power supply for customers.

• Extended Equipment Lifespan: Proactive maintenance reduces wear and tear on components, extending the life of valuable assets such as conductors, insulators, and transformers. This saves on long-term replacement costs.

• Improved Operational Efficiency: A well-maintained electrical system operates at peak performance, reducing energy waste and lowering operational costs. This ensures your investment in quality equipment provides a maximum return.

• Regulatory Compliance: Following a strict maintenance schedule helps you comply with local and international safety standards and regulations, avoiding legal penalties and liability issues.

It's important to recognize the warning signs that indicate your electrical system needs maintenance. These include:

• Flickering or dimming lights which can signal a loose connection or an overloaded circuit.

• Warm or humming sounds coming from electrical equipment, outlets, or circuit breakers.

• Burning smells or scorch marks around electrical panels and wiring.

• Frequent tripping of circuit breakers, which often indicates an overload or a short circuit.

• Visible wear and tear on conductors, insulators, and other hardware, such as corrosion, fraying, or physical damage.

If any of these signs are present, it is critical to address them immediately with professional tools and equipment to prevent further damage and ensure safety. Our company, Ningbo Changshi, provides the necessary tools for every stage of electrical maintenance, from inspection to repair.

Electricity is transmitted at very high voltages (e.g., 66 kV to 765 kV) to minimize power loss over long distances. According to the laws of physics, a higher voltage allows for a lower current to transmit the same amount of power. Since power loss is proportional to the square of the current (I²R), reducing the current significantly reduces energy waste. Once the electricity reaches a local substation, its voltage is "stepped down" by transformers to a safer, lower level (e.g., 220V, 400V) suitable for consumer use in the distribution network.

The equipment for transmission and distribution differs significantly due to the voltage and distance requirements.

• Transmission Equipment: This includes large, robust structures like lattice steel towers or tubular steel poles, designed to support heavy conductors over long spans. The conductors themselves are thicker and often bundled to increase capacity and reduce energy loss from corona discharge. This is where our overhead transmission line equipment and tools are used.

• Distribution Equipment: This consists of smaller wooden or concrete poles and thinner conductors. It also includes the transformers that step down the voltage for local use, as well as a variety of specialized tools and accessories for connecting to homes and businesses. Our underground cable laying equipment is also a key part of modern distribution networks, especially in urban areas.

Answer: The primary difference lies in their composition. OPGW (Optical Ground Wire) is a hybrid cable that serves a dual purpose: it acts as a traditional ground wire for lightning protection and also contains optical fibers for communication. Its core is metallic, typically made of aluminum-clad steel or aluminum, which provides high mechanical strength and electrical conductivity.

In contrast, ADSS (All-Dielectric Self-Supporting) cable is entirely non-metallic, or "all-dielectric." It uses high-strength aramid yarns or glass-reinforced plastic (GRP) as strength members. This composition makes it non-conductive, lightweight, and completely immune to electromagnetic interference, but it cannot function as a ground wire.

Answer: The choice depends on the specific project requirements. OPGW is generally the preferred choice for new high-voltage transmission lines (e.g., 110kV and above) where an overhead ground wire is required. Its metallic structure provides essential lightning protection and grounding, while also providing an integrated communication channel.

ADSS cables are ideal for adding new communication lines to existing high-voltage transmission and distribution lines without replacing the ground wire. Since they are all-dielectric and non-conductive, they can be installed without a power outage, making them a cost-effective and flexible solution for modernizing communication networks.

Answer: OPGW installation is more complex and typically more expensive. Because it is a metallic ground wire, the installation usually requires a power shutdown. Its heavier weight and specialized hardware also contribute to higher material and labor costs.

ADSS cable is significantly easier and more cost-effective to install. Its non-conductive nature allows for live-line installation (without a power outage), which minimizes disruption and saves on project costs. Its lightweight design also requires less complex equipment and hardware.

Answer: OPGW installation is more complex and typically more expensive. Because it is a metallic ground wire, the installation usually requires a power shutdown. Its heavier weight and specialized hardware also contribute to higher material and labor costs.

ADSS cable is significantly easier and more cost-effective to install. Its non-conductive nature allows for live-line installation (without a power outage), which minimizes disruption and saves on project costs. Its lightweight design also requires less complex equipment and hardware.

Answer:

• OPGW cables are primarily used in the electric utility industry for high-voltage transmission lines. They serve as a crucial component for lightning protection, grounding, and high-speed data transmission for SCADA (Supervisory Control and Data Acquisition) systems, voice, and video communication.

• ADSS cables are widely used in various telecommunication applications. Their self-supporting design and resistance to EMI make them suitable for installation on power distribution and transmission poles, railways, and other aerial environments where adding a new ground wire is not feasible. They are commonly used for FTTX networks, broadband, and long-distance communication.

Underground cables offer several significant advantages over overhead lines:

• Safety & Reliability: They are far less susceptible to damage from severe weather like storms, high winds, and lightning, which leads to fewer power outages.

• Aesthetics: Underground cables eliminate the visual clutter of poles and wires, preserving the natural or urban landscape.

• Public & Wildlife Safety: Since the conductors are not exposed, they pose no risk of electrocution to the public or wildlife and do not interfere with low-flying aircraft.

• Environmental Impact: They are less likely to cause wildfires and have a reduced electromagnetic field (EMF) emission into the surrounding area.

Overhead lines are directly exposed to the elements. They are vulnerable to damage from high winds, ice storms, lightning strikes, and falling trees. While repairs are typically faster and easier to locate, the frequency of weather-related faults is a major disadvantage.

Underground cables, by contrast, are largely unaffected by these conditions. This makes them a much more reliable option in areas prone to severe weather. However, they can be susceptible to damage from flooding, seismic activity, or soil disturbances.