While the concept of transmitting electricity through the air has captured the public's imagination since the time of Nikola Tesla, it is not a feasible or efficient solution for a large-scale power grid. While electricity can be transmitted short distances without wires (e.g., through inductive charging), long-distance transmission through the air faces significant technical and efficiency challenges.

• Significant Energy Loss: Transmitting power through the air over long distances is highly inefficient. The energy would dissipate rapidly as it travels, with a significant portion being lost to the atmosphere and the surrounding environment. This makes it a very impractical and costly method for bulk power delivery.

• Safety Concerns: High-power wireless transmission would pose immense safety risks to humans, animals, and the environment. The high levels of electromagnetic radiation required to transmit power could be hazardous to living organisms and could interfere with other electronic systems.

• Feasibility and Cost: The infrastructure required for a wireless power grid would be astronomical to build and maintain, far outweighing the cost of the existing wired grid.

For these reasons, the most efficient, safe, and reliable method for bulk power transmission remains the use of high-voltage conductors, which is the foundation of our business.

Wireless charging for small devices like smartphones and electric toothbrushes is a form of wireless power transfer, but it operates over very short distances using a principle called electromagnetic induction.

• Transmitter and Receiver Coils: The charging pad (transmitter) contains a coil of wire, and the device being charged (receiver) has a similar coil.

• Magnetic Field Generation: When electricity flows through the transmitter coil, it creates a magnetic field.

• Induced Current: When the receiver coil is placed in close proximity to this magnetic field, the field induces an electrical current in the receiver coil, which then charges the device's battery.

This technology is highly efficient and safe, but only over very short, controlled distances (a few millimeters to centimeters). It is not a viable technology for transmitting the massive amounts of power required to run a city or factory.

The existing power grid, with its system of overhead and underground conductors, remains the most effective solution for a modern society. It is based on the proven principles of electromagnetic conduction, which offer:

• Maximum Efficiency: Wired systems can transmit power over hundreds of kilometers with minimal energy loss (typically less than 5%), which is far superior to any long-distance wireless method.

• Safety and Reliability: The physical conductors are contained and insulated, ensuring a predictable and secure power supply that is not susceptible to atmospheric interference or health risks from stray radiation.

• Scalability: The current grid is a robust, interconnected system that can handle fluctuations in supply and demand, a capability that wireless transmission technology simply cannot match today.

At Ningbo Changshi Electric Power Machinery Manufacturing Limited, our mission is to provide the highest quality tools and equipment for this proven and reliable grid. From our OHTL wire cable conductor tension stringing equipment to our underground cable laying equipment, we ensure that every stage of power transmission and distribution is built to be as efficient and safe as possible, guaranteeing a sustainable energy future.

The primary difference lies in the type of current used: Alternating Current (AC) or Direct Current (DC). Both have specific applications and advantages in the power grid.

• High-Voltage Alternating Current (HVAC): This is the most common type of transmission system used globally. Its key advantage is the ease with which voltage can be stepped up or down using transformers, making it highly flexible for an interconnected grid. HVAC is most economical for short to medium distances and is the standard for power distribution to homes and businesses.

• High-Voltage Direct Current (HVDC): HVDC transmission is the preferred method for transmitting large amounts of power over very long distances (e.g., hundreds or thousands of kilometers), particularly for connecting remote power sources like hydro or wind farms to urban centers. Its main advantages are significantly lower power loss over long distances and its ability to connect two different AC power grids that are not synchronized. HVDC is also the only feasible option for long-distance submarine or underground power cables.

Our OHTL wire cable conductor tension stringing equipment is widely used for both HVAC and HVDC overhead lines, ensuring the precise and efficient installation of conductors for any project, regardless of the current type.

Electricity can be transmitted through conductors either above or below the ground. The choice between overhead and underground systems depends on factors like cost, environment, safety, and capacity.

• Overhead Transmission: This is the most common and cost-effective method for long-distance transmission. It involves bare conductors suspended from poles or lattice towers. Its advantages include lower installation costs, easier maintenance, and higher capacity for bulk power transfer. However, it is vulnerable to weather events and has a significant visual impact.

• Underground Transmission: This method involves insulated cables buried in trenches, ducts, or tunnels. It is more expensive to install but offers a higher level of public safety, is protected from extreme weather, and has a minimal visual footprint. It is the preferred choice for densely populated urban areas, sensitive natural environments, and river or sea crossings.

Our comprehensive product line includes both Overhead Transmission Line Equipment for the construction of towers and stringing overhead conductors, and a complete suite of Underground Cable Laying Equipment for projects that require power to be delivered beneath the ground.

The equipment used for electricity transmission and construction is highly specialized and can be categorized into three primary areas, each with a distinct function in building and maintaining the power grid.

1. Overhead Transmission Line (OHTL) Equipment: This category includes the heavy machinery and tools used to build and maintain the massive overhead power lines that carry electricity over long distances. The key equipment in this category is our wire cable conductor tension stringing equipment, which includes:

   • Hydraulic Pullers: Used to pull the conductor from a drum to the next tower.

   • Hydraulic Tensioners: Used to apply back tension to the conductor, ensuring it is installed with the correct sag and tension to prevent damage.

   • Anti-twisting Steel Ropes, Swivels, and Connectors: Critical accessories for the stringing process.

2. Underground Cable Laying Equipment: As a growing alternative, underground power lines require a different set of tools and machinery to install cables safely beneath the ground. This includes specialized equipment like:

   • Cable Pulling Winches: Used for pulling heavy cables through trenches or ducts.

   • Cable Rollers and Sheaves: To guide cables during the laying process.

   • Cable Stand Jacks: Used to support cable drums and facilitate unwinding.

3. Substation and General Electrical Construction Tools: In addition to the large machinery, a wide array of tools is required for the construction, maintenance, and repair of substations and other electrical infrastructure. These include safety equipment, grounding tools, cable cutters, crimpers, and a variety of specialized hand tools.

As a prominent manufacturer and exporter, Ningbo Changshi is proud to offer a comprehensive, one-stop supply of all these categories of equipment.

Electrical transmission is also categorized by its voltage level, which directly impacts its purpose and the distance it can cover.

• High-Voltage (HV): Typically operating at 115 kV to 230 kV, this is used for regional transmission networks, connecting major substations and cities.

• Extra-High Voltage (EHV): Operating at 345 kV to 765 kV, EHV lines form the core "superhighway" of the power grid, transmitting electricity in bulk over vast distances.

• Ultra-High Voltage (UHV): Operating at 800 kV and higher, UHV is the most advanced form of transmission, designed for maximum efficiency over extremely long distances, often used in large countries to move power from remote generation sources to demand centers.

At Ningbo Changshi, our tools and equipment are built to meet the rigorous demands of projects at every voltage level, ensuring that our customers have the reliable and high-performance equipment they need to build and maintain the power grids of today and tomorrow.

Ultra-High Voltage (UHV) transmission refers to electricity transmission at voltages of 800 kV and higher. It is a technological leap in power transmission, designed to meet the growing global demand for electricity while addressing the challenges of efficiency and sustainability.

Why UHV is Used:

• Minimizes Power Loss: The primary advantage of UHV is its ability to transmit a massive amount of power over thousands of kilometers with significantly less energy loss. Power loss is proportional to the square of the current, so by increasing voltage, UHV reduces the current needed for the same amount of power, drastically cutting down on energy wasted as heat.

• Enables Remote Energy Integration: UHV is essential for connecting large-scale, remote renewable energy sources (like hydropower dams in the mountains or solar farms in deserts) to distant population and industrial centers.

• Reduces Land Use: By carrying more power on each line, a single UHV line can replace multiple lower-voltage lines, reducing the overall right-of-way needed for the grid.

At Ningbo Changshi, we understand that UHV requires the most advanced and robust tools. Our specialized OHTL wire cable conductor tension stringing equipment is engineered to handle the larger, heavier, and more complex conductor bundles used in UHV projects, ensuring precision and safety.

UHV transmission, while highly efficient, introduces unique technical challenges that require specialized solutions and equipment.

• Insulation: The immense voltage requires greater air clearances between conductors and the tower body to prevent arcing. This demands larger, more robust insulators and carefully designed tower structures.

• Corona Discharge: At such high voltages, the electric field around the conductors can ionize the air, causing a "corona" effect, which results in power loss, audible noise, and radio interference. To mitigate this, UHV lines use bundled conductors, where each phase consists of multiple sub-conductors arranged in a bundle.

• Specialized Equipment: The massive scale of UHV projects, with heavier conductors and greater spans, requires highly specialized construction equipment.

Our company, Ningbo Changshi, provides the critical tools to overcome these challenges. Our hydraulic tensioners and pullers are designed with the high torque and precision needed to safely string the large, bundled conductors for UHV lines, and our general overhead tools and accessories are built to meet the rigorous safety and performance standards of these demanding projects.

The construction of an overhead power line is a complex process that requires specialized tools for each stage. While the overall process involves ground work and tower erection, the most critical phase is the conductor stringing. To build an overhead power line efficiently and safely, you need:

• Hydraulic Tensioners and Pullers: These are the core machines for conductor stringing. The puller pulls the conductor across the line, while the tensioner controls the back tension to ensure the conductor is installed correctly.

• Conductor Stringing Blocks/Sheaves: Mounted on the towers, these guides allow the conductor to be pulled smoothly from one span to the next.

• Anti-Twisting Steel Ropes: Used for pulling conductors to prevent rotation and ensure a smooth stringing process.

• Swivels and Joints: To connect the pull rope to the conductor and allow for rotation-free pulling.

We specialize in all the essential Overhead Transmission Line Equipment for this process, ensuring our clients can handle any project, from a standard power line to a massive UHV project with bundled conductors.

The main difference lies in the fundamental process. Overhead projects are about tensioning and stringing cables from above, while underground projects are about pulling and laying cables from below.

• Overhead tools are designed for stringing cables under controlled tension over long spans, often across challenging terrain. The machinery, like tensioners and pullers, is built to be powerful and precise to handle the weight and tension of long conductor runs.

• Underground tools are designed for pulling cables through ducts or open trenches. The equipment, such as cable pulling winches and rollers, focuses on guiding and pulling the cables without damaging their insulation as they are laid below ground.

Our company's unique position as a comprehensive one-stop supplier means we have the expertise and product lines for both types of projects, allowing our clients to source all their necessary equipment from a single, trusted partner.

A three-phase electricity transmission system is a method of generating, transmitting, and distributing alternating current (AC) electric power. It uses three separate conductors, each carrying an alternating current with the same frequency but shifted by 120 electrical degrees from the other two. This staggered arrangement ensures that power is delivered continuously, without the cyclical peaks and dips that occur in single-phase systems.

This design is the foundation of modern power grids, from the high-voltage transmission lines that span countries to the local distribution networks that power large commercial and industrial facilities. The three-phase system's ability to provide a consistent power flow makes it ideal for running large electric motors and other heavy-duty machinery.

Our company specializes in the essential Overhead Transmission Line Equipment required to build and maintain these complex three-phase systems, ensuring they operate with maximum efficiency.

The equipment used for three-phase transmission is designed to handle the increased complexity and demands of the system. While many of the tools are similar in principle, they are often larger, more powerful, and specifically configured for three-phase work. Key differences include:

• Conductor Stringing: Three-phase lines require the simultaneous or sequential stringing of three (or more, in the case of bundled conductors) individual conductors. Our Hydraulic Pullers and Tensioners are designed with multiple grooves and sufficient power to manage the installation of all phases at once, ensuring the correct sag and tension for each line.

• Sheaves and Rollers: The stringing blocks and rollers used on transmission towers are specifically designed to accommodate up to three conductors, often with specialized designs to prevent twisting or damage to the lines during the stringing process.

• Safety and Grounding Tools: Due to the higher voltages and multiple live phases, the safety and grounding equipment used on three-phase lines is highly specialized, ensuring that crews can safely work on or near energized lines.

Our comprehensive product range includes all the necessary machinery and tools to construct and maintain three-phase power lines, positioning Ningbo Changshi as an expert and trusted partner for any electrical project.

Three-phase power is the standard for electricity transmission due to its significant technical and economic advantages over single-phase systems:

• Higher Power Density: A three-phase system can transmit nearly twice the power of a single-phase system using only 1.5 times as many conductors. This means more power can be delivered with less material, making it a more economical solution for large-scale projects.

• Constant Power Flow: Unlike single-phase systems, which experience power pulsations, three-phase systems deliver a steady, uninterrupted flow of power. This is crucial for motors and large machinery, as it reduces vibrations, extends equipment lifespan, and enhances overall efficiency.

• Reduced Conductor Requirements: The currents in a balanced three-phase system sum to zero, which means a neutral wire is not always needed, or a much smaller one can be used. This saves on conductor material and weight.

• Simpler Motor Design: Three-phase power naturally creates a rotating magnetic field, which simplifies the design of electric motors. They do not require an additional starting mechanism, making them more reliable, efficient, and cost-effective than single-phase motors.

Our OHTL wire cable conductor tension stringing equipment is specifically engineered to handle the conductors and lines of these high-capacity, three-phase systems.

In the power industry, losses are categorized into two main types:

1. Technical Losses: These are unavoidable losses that occur naturally within the physical components of the grid. They are inherent to the process of transmitting electricity and are primarily caused by the resistance of conductors, transformers, and other equipment. A significant portion of these losses is due to resistive heating, where some electrical energy is converted into heat as it travels through power lines.

2. Non-Technical Losses: These are also known as commercial losses and are entirely preventable. They are not related to the physical properties of the grid but rather to human and administrative factors, such as electricity theft, faulty metering, billing errors, and unbilled consumption.

While technical losses can be minimized, they can never be fully eliminated. Non-technical losses, however, can be significantly reduced through better management and technological solutions.

Technical losses are an inherent part of the electrical system and are influenced by several factors. The main causes include:

• Joule Heating (

  I2R

  Loss): This is the most significant cause of technical loss. As current (

  I

  ) flows through a conductor with a certain resistance (

  R

  ), a portion of the electrical energy is dissipated as heat. The amount of loss is proportional to the square of the current, making it a critical factor in system design. This is why power is transmitted at ultra-high voltages—to reduce the current and, consequently, minimize this type of loss.

• Corona Losses: At very high voltages, the electric field around the conductors can be strong enough to ionize the surrounding air, creating a faint glow and dissipating energy as sound, light, and heat. This is a form of power loss that is more prevalent in high-voltage transmission lines.

• Transformer Losses: Transformers, which are essential for stepping voltage up and down, have their own inherent losses. These include core losses (from hysteresis and eddy currents in the magnetic core) and copper losses (from the resistance of the windings).

While some power loss is unavoidable, it can be minimized through a combination of smart grid design and the use of high-quality equipment. This is where our products play a critical role.

1. Minimizing Resistive Losses: The quality and precision of the conductor installation directly impact the overall resistance of the line. Our OHTL wire cable conductor tension stringing equipment ensures that conductors are installed with the precise tension and sag required, preventing loose connections or damage that could increase resistance and lead to higher

   I2R

   losses.

2. Ensuring Optimal Connections: Using our specialized tools and accessories for overhead and underground projects ensures that every connection is secure and has minimal resistance, reducing energy dissipation at every point in the network.

3. Enhancing Overall Grid Efficiency: By providing the industry with the most reliable and high-performance equipment, Ningbo Changshi helps our clients build more efficient power lines and infrastructure, reducing energy waste and improving the long-term sustainability of the grid.

Choosing the right tools for construction and maintenance is a key step in mitigating technical losses and ensuring a more efficient and reliable power supply.

The electricity transmission grid infrastructure supply chain is a complex global network that connects a variety of players to deliver all the necessary materials and equipment for building and maintaining the grid. The supply chain can be broken down into three key stages:

1. Raw Materials & Components: This initial stage involves the sourcing of critical materials such as steel for towers, aluminum and copper for conductors, and specialized plastics and ceramics for insulators.

2. Manufacturing: This is where the raw materials are transformed into finished products like power transmission towers, substation equipment (e.g., transformers and circuit breakers), and the specialized OHTL wire cable conductor tension stringing equipment used for installation.

3. Construction, Installation & Maintenance: This final stage involves utility companies and engineering, procurement, and construction (EPC) contractors using the manufactured equipment and tools to build and maintain the grid. This phase requires a seamless flow of materials and tools to avoid costly project delays.

As a prominent China manufacturer and exporter, Ningbo Changshi is a critical link in the manufacturing stage, providing a wide array of high-quality tools and equipment that are essential for the final construction and maintenance phase of this supply chain.

The global power grid supply chain is currently facing unprecedented challenges driven by increasing demand, geopolitical factors, and economic pressures. The most significant challenges include:

• Supply Chain Bottlenecks: There is a high global demand for key components like transformers, insulators, and specialized equipment, leading to extended lead times and significant price increases. This can delay critical projects for months or even years.

• Logistical Complexity: The transportation of massive and heavy components like transmission towers and stringing equipment across countries and continents requires highly specialized logistics, which can be disrupted by global events.

• Geopolitical and Trade Barriers: Global trade restrictions and geopolitical tensions can complicate the sourcing of materials and equipment, increasing costs and creating uncertainty for project developers.

• Quality and Reliability: The need for reliable, high-voltage equipment means that sourcing from unverified suppliers can lead to safety risks and operational failures down the line.

These challenges highlight the critical need for reliable and efficient suppliers who can provide consistent, high-quality products.

Ningbo Changshi Electric Power Machinery Manufacturing Limited is specifically positioned to help our global clients overcome these supply chain challenges by offering a strategic, streamlined solution.

• One-Stop Supply: Our business model is centered on being a comprehensive one-stop supply for all overhead and underground line projects. Instead of managing multiple vendors for tensioners, pullers, ground wire machines, and other tools, our clients can source everything from a single, reliable partner. This reduces logistical complexity, saves time, and lowers costs.

• Established Global Export Network: We have a proven track record of exporting our equipment to customers worldwide. This expertise in global logistics and trade ensures that our products reach project sites efficiently and reliably, minimizing the risk of project delays.

• Quality and Expertise: As a specialized manufacturer, we control our own manufacturing processes to ensure the highest quality standards. Our deep expertise in the industry means we understand the specific needs of modern power grid projects and can provide the right tools for the job, ensuring safety and efficiency.