Classification, function and application fields of power cables
Power cables are used to transmit and distribute large-scale electrical energy in the mains of the power system, and control cables directly transmit the electrical energy from the distribution points of the power system to the power connection lines of various electrical equipment. In terms of the number of cable cores, according to the requirements of the power grid, the power cable is generally 5 cores, while the control cable is used to transmit control signals.
Classification of power cables: 1. Coaxial cables. Coaxial cable is a transmission medium familiar to many friends. It is a cable with multiple layers of insulated wire wrapped around an intermediate copper conductor. It is characterized by good anti-interference ability, stable data transmission and low price. 2. Twisted pair is a flexible communication cable that contains multiple pairs of insulated copper wires. It is characterized by low price, so it is widely used, such as our commonly used telephone lines. 3. Optical fiber cable. Compared with copper medium, fiber optic cable is a new generation transmission medium. Optical fiber has greatly improved reliability, security and network performance.
Power cables are divided into high-voltage cables and low-voltage cables. If it is high voltage, there will be a layer of resin-like filler inside to insulate. In high-voltage cables, this layer is an important part of insulation. The low-voltage power cable does not have this layer, and there are some ribbon-like things wrapped in it, which are to fix the various core wires of the cable and fill the gap in the middle.
The role of the power cable shielding layer is as follows: 1. Because the current passing through the power cable is relatively large, a magnetic field will be generated around the current. In order not to affect other components, the shield can shield the electromagnetic fields in the cable. 2. It can play a certain role in grounding protection. If the core wire of the cable is damaged, the leakage current can flow along the shielding layer like a grounding net, which plays a role of safety protection.
Application of power cable: 1. Power system. The wire and cable products used in the power system mainly include overhead bare wires, bus bars, power cables (plastic cables, oil-paper power cables, rubber sheathed cables, overhead insulated cables), branch cables, electromagnetic wires and electrical equipment wires and cables, power equipment cables, etc. . 2. Information transmission system. The wires and cables used in the information transmission system mainly include data cables, electronic cables, radio frequency cables, TV cables, electromagnetic wires, optical cables, power communication or other composite cables. 3. Instrumentation system, mechanical equipment. Except overhead bare wires, almost all products have applications, but mainly data cables, magnet wires, power cables, instrument cables, etc.