Product series of power cables
Polyvinyl chloride insulated power cables: Polyvinyl chloride plastics are cheap, have good physical and mechanical properties, and have simple extrusion processes, but their insulation properties are average. They are used in large quantities to manufacture low-voltage power cables of 1 kV and below for use in low-voltage distribution systems. If insulating materials with voltage stabilizers are used, 6 kV cables can be produced.
Cross-linked polyethylene insulated power cables: Good electrical properties, mechanical properties and heat resistance. In the past two decades, it has become the leading variety of medium and high voltage power cables in my country, and can be used in various voltage levels from 6 to 330 kV. In recent years, cross-linking of 1 kV low-voltage cables has become a technical direction. The key is to reduce the insulation thickness so that it can compete with polyvinyl chloride cables in terms of price.
Viscous oil-impregnated insulated power cables: They were the leading products of medium-voltage cables in my country before 1992. This is a classic structure of power cables with a history of more than 100 years, with large electrical and thermal performance margins and long service life.
Oil-filled cable: suitable for 66-500 kV.
Rubber insulated power cable: a soft, movable power cable, mainly used in places where enterprises often need to change the laying position. Natural rubber insulation is used, the voltage level is mainly one kV, and 6 kV level can be produced.
Overhead insulated cable: essentially an overhead conductor with insulation, the insulation can be made of polyvinyl chloride or cross-linked polyethylene. Generally made into a single core, or 3-4 phase insulated cores can be twisted into a bundle without sheath, which is called a bundled overhead cable.
Characteristics of power cables:
Compared with other overhead bare wires, its advantages are less affected by external climate, most reliable, concealed, less maintenance, durable, and can be laid in various occasions. However, the structure and production process of power cables are relatively complex and the cost is relatively high.
Different specifications, but all have the following characteristics and manufacturing requirements:
The working voltage is high, so the cable is required to have excellent electrical insulation performance.
The transmission capacity is large, so the thermal performance of the cable is more prominent.
Since most of them are fixedly laid in various environmental conditions (underground, tunnel trenches, shaft slopes, and underwater, etc.), and require reliable operation for decades, the requirements for sheath materials and structures are also high.
Due to changes in factors such as power system capacity, voltage, number of phases, and different laying environmental conditions, the varieties and specifications of power cable products are also quite numerous. According to the strong electrical characteristics of power cable applications, the consideration of its electrical and mechanical properties is relatively prominent.