Low - Voltage Distribution System For Cable Gland
As a certain power factor, the Cable Gland to deliver the same power, the higher the transmission voltage, the smaller the transmission current. In this way, on the one hand can reduce the power loss on the transmission line, on the other hand can choose a smaller cross-sectional transmission lines, saving conductive materials. Therefore, long-distance transmission needs to be carried out with high pressure. The farther the transmission distance, the greater the output power, the higher the required transmission voltage. For example, when the transmission voltage is 110kV, the power of 50,000 kilowatts can be transported to 50 ~ 150km. When the transmission voltage is 220kV, the transmission capacity can be increased to 20 ~ 300,000 kilowatts, and the transmission distance can be increased to 200 ~ 400km. Transmission voltage of 500kV ultra-high voltage, transmission capacity can be as high as 100 million kilowatts, transmission distance can also be increased to 500km or more. As the current rated voltage of the generator is generally about 10kV, it is necessary to use the transformer installed in the metal Cable Gland in the transformer voltage will be increased to the required value of transmission, and then long-distance transmission. When the power delivered to the electricity area, due to the current work, agricultural production and civil construction power, high pressure for the 10kV, 6kV, low voltage of 380V and 220V, which in turn need to pass the substation will be transported to the high voltage , And then assigned to the various electricity areas, and then depending on the different requirements, the use of a variety of transformers to get different voltage. Transformer installed in the boost or buck with the transformer, control switches, protective devices and measuring instruments, etc., can be voltage on the pressure, voltage regulation, control and monitoring. Power transmission from the power plant to the user, need to go through the boost, transmission, buck, distribution and other intermediate links, known as the power grid; by the power plant, power grid and power users of the system known as the power system.
China's national standard power grid rated voltage of 3kV, 6kV, 10kV, 110kV, 220kV, 330kV, 500kV and so on.
As the current urban transmission voltage is generally about 10kV (except large factories and mines enterprises), therefore, the general factories and mines and civil buildings must be set to step-down substation, the distribution transformer voltage will be reduced to 380 / 220V, and then lead A number of power lines to each point (workshop or building) on the distribution box, and then by the distribution box will be allocated to the power supply equipment. This low-voltage power supply system wiring methods are mainly two kinds of radiation and trunk.