The application of power cable has a history of development, evolution and evolution for more than 100 years. According to the use requirements of different occasions, there are a variety of different power cables.

Power cables are generally classified according to current category and insulation material.

1. Classification by current category

Power cables can be divided into AC power cables and DC power cables according to current.

(1) AC power cable. The voltage grades of AC power cables are 220 / 380V, 10kV, 35 kV, 66 kV, 110 kV, 220 kV, 500 kV, 750 kV and 1000 kV. Generally, 220 / 380V is distribution cable, 10 kV and above are high-voltage cables, and 110 kV and above are ultra-high voltage cables.

(2) DC power cables. The voltage levels of DC power cables are ± 400, ± 500, ± 600, ± 800 kV, all of which are EHV DC cables.

2. Classification by insulating material

Power cables can be divided into:

(1) Oil paper insulated cable: the cable with insulating paper tape impregnated with insulating oil as insulating protective layer is oil paper insulated cable. Due to different impregnants, it can be divided into viscous oil immersed paper insulated cable, non trickle oil immersed paper insulated cable, oil filled oil immersed paper insulated cable and inflatable viscous oil immersed paper insulated cable, which are generally used for voltage levels of 6.6kV and above.

(2) Rubber insulated cable: the cable with rubber material with insulation performance as the insulation protective layer is rubber insulated cable. Due to different types of rubber, it can be divided into natural rubber cable, ethylene propylene rubber cable and silicone rubber cable, which are generally used in 220 ~ 380V low-voltage distribution system.

(3) Plastic insulated cable: cable with chemical plastic material as insulating protective layer, plastic insulated cable. According to the material, it can be divided into PVC power cable, polyethylene power cable and cross-linked polyethylene power cable. It has a wide range of application fields, many quantities and varieties, and is widely used at all levels of voltage.

(4) Special insulated cables: power cables made of special insulating materials according to different requirements such as environmental function and transmission capacity. According to different special insulation materials, it can be divided into the following four types:

1) Pipeline SF6 inflatable cable for transmitting large capacity electric energy (applicable to 400kV EHV and 1 million KVA large capacity).

2) High purity copper is used as conductor material, liquid nitrogen or liquid hydrogen is used as insulator, and the resistance of conductor material decreases sharply with absolute temperature at very low temperature to deeply cool the low-temperature resistive cable (meet the high-capacity power transmission).

3) General flame retardant cables with polyolefin with oxygen index not less than 28 as the outer protective layer and with a layer of inorganic metal compound [A1 (OH) 2] filled between the insulating layer and the outer sheath. In case of fire, the compound decomposes immediately to produce a layer of nonflammable and non molten colloidal metal oxide crystal water, which is wrapped outside the insulating layer to isolate oxygen and achieve the purpose of flame retardant.

4) Taking superconducting material or superconducting alloy as conductor material, the power cable that transmits electric energy under the conditions of critical temperature, critical magnetic field strength and critical current density is superconducting power cable.

This article is from Jiangsu Hansheng Cable Technology Co., Ltd. www.jshansheng.com. Please indicate the source for reprint!