High voltage transmission principle

High-voltage transmission is a way to boost the voltage output by the generator through the transformer in the power plant and then send it out. The reason why this method is used for power transmission is that the higher the voltage, the smaller the current, so that high-voltage power transmission can reduce the current during power transmission, thereby reducing the heat loss caused by the current and reducing the material cost of long-distance power transmission.

The electric energy generated by the power station should be transmitted to all places where electricity is used through transmission lines. Different high voltages are used according to the distance of electric energy transmission.

According to China's power situation, when the transmission distance is 200 ~ 300 km, the voltage of 220 kV is used for power transmission. 1 100 kV is used around 100 km; About 50 kilometers, with 35 kV or 66kv；; At 15km ~ 20km, use 12kv and part of 6300kv.

Extended data:

Because the power loss on the transmission line is proportional to the square of the current (Joule's Law Q = I 2RT), it is necessary to use a large power transformer to increase the voltage to reduce the current and reduce the heating of the conductor, so as to effectively reduce the power loss on the transmission line.

The power generated by the power plant is certain, which depends on the power generation capacity of the generator set. According to P=UI, the power of the generator is constant. If the voltage u in the transmission line increases, the current I in the line will definitely decrease.

Natural disasters are the main cause of frequent failures of high-voltage transmission equipment during operation. These force majeure factors greatly increase the difficulty and intensity of operation and maintenance of high-voltage transmission equipment. However, regardless of the weather or the corresponding geological changes, the operators and maintenance personnel of high-voltage transmission equipment should minimize the accident scope.

Baidu Encyclopedia-High Voltage Transmission