The problem of high voltage transmission, why high voltage transmission of electricity?

First of all, we have to correct a mistake: the transmission is a pure resistance circuit, and all the electrical energy is used to generate heat, and the transformer only changes the voltage, and only a very small part of it heats up, which is also a pure circuit resistance.

So you can use p=i 2r and you say p=iu but you can't because p means p loss, so u should also use u loss, do you know how much u is lost?

Power lines are not purely resistive electronic components.

Think of it as a wire connected to a resistor.

No, v=ir doesn't work here.

In a non-pure resistance circuit, only the resistive element produces Joule thermal loss energy, and the other components of inductance capacitance can also be approximated in the form of inductive reactance and capacitive reactance, which can be approximated as wire resistance, so it can be calculated by Ohm's law.

Any one of the three formulas is the same, but the u in the last two formulas should use the voltage drop on the transmission line, which is actually U=IR, not the total transmission voltage, and most of the voltage is used to promote the electrical appliances to do work. p=u total *i is the total power including useful power and line loss.

These formulas are all transformed into each other by Ohm's law and are equivalent. The key is to be clear about the use of ** u

The reason why this method of transmission is adopted is that in the case of the same transmission power, the higher the voltage, the smaller the current, so that the high-voltage transmission can reduce the current during transmission, thereby reducing the heat loss caused by the current and reducing the material cost of long-distance transmission.

The electricity generated from the power station is generally sent to the various places where electricity is consumed through the transmission line. Depending on the distance of the power to be transmitted, different high voltages are used. From the perspective of China's power situation, the transmission distance is 200 300 kilometers away from 220 thousand volts;

110 kV at about 100 km; 35 kV or 66 kV for about 50 km; At 15 km and 20 km, 10 kV, 12 kV, and some use 6300 V.

High-voltage transmission in order to reduce consumption and reduce costs.

The reason why high-voltage transmission is used is that in the case of the same transmission power, the higher the voltage, the smaller the current, so that high-voltage transmission can reduce the current during transmission, thereby reducing the heat loss caused by the current and reducing the material cost of long-distance transmission.

Because the power loss on the transmission line is proportional to the square of the current (Joule's law q=i rt), it is necessary to use a large power transformer to increase the voltage to reduce the current and reduce the heat generation of the conductor in order to effectively reduce the loss of electric energy on the transmission line.

If the current in the line is reduced to the original 1 2, then the power loss in the line is reduced to (1 2) 2 = 1 4 of the long loss, so increasing the voltage can effectively reduce the power loss in the line.

According to the nature of the transmitted current, transmission is divided into AC transmission and DC transmission

In the 80s of the 19th century, direct current transmission was first successfully achieved. However, due to the difficulty of continuing to increase the voltage of DC transmission under the technical conditions at that time, the transmission capacity and efficiency were limited.

At the end of the 19th century, direct current transmission was gradually replaced by alternating current transmission. The success of AC transmission ushered in a new era of electrified society in the 20th century.

It is widely used in three-phase AC transmission, with a frequency of 50Hz (or 60Hz). Since the 60s of the 20th century, there has been a new development of DC transmission, which is combined with AC transmission to form an AC and DC hybrid power system.

The above content refers to Encyclopedia - High Voltage Transmission.

High-voltage transmission can reduce the loss of electric energy, thereby improving transmission efficiency. High-voltage transmission is a method of boosting the voltage output from a generator through a transformer in a power plant and transmitting it. The reason why this method of power transmission is adopted is because in the case of the same transmission power, the higher the voltage, the smaller the current, so that the high-voltage transmission can reduce the current during transmission, thereby reducing the heat loss caused by the current and reducing the cost of material destruction for long-distance transmission.

In terms of reducing the electrical power loss on the transmission line and saving the materials used in the transmission line, high voltage or ultra-high voltage should be used for long-distance transmission of electric energy. However, the higher the transmission voltage, the stricter the requirements for the construction of the transmission overhead line, the higher the cost of the line. Therefore, it is necessary to proceed from the specific actual situation to achieve that the transmission line can not only reduce power loss, but also save construction investment.