Understanding how DC lines work

A DC wire (direct current wire) is a wire used to carry direct current. It consists of two conductors (usually metallic materials), one of which is referred to as the positive terminal and the other as the negative terminal.The operation of a DC wire involves the way in which current flows and the ability of the material to conduct the current.

DC is a current with a constant current direction, which always flows in one direction in a circuit. when a DC wire carries DC current, the current enters from the positive pole of the power supply to the negative pole. This current direction always remains the same, so DC wire needs to maintain the correct polarity in the circuit.

The conductors of DC lines are generally made of metal materials because metals have good electrical conductivity. Conductivity is a measure of the ability of a conductor material to conduct current. The conductivity of metals is usually high, so DC lines are able to carry current efficiently.

In a DC wire, the flow of current involves the movement of electrons. Electrons are elementary particles with a negative charge, and they are subject to forces that move them under the action of an electric field. When a DC current passes through a DC wire, the positive terminal attracts electrons, causing them to start flowing from the positive terminal, through the conductor of the wire and eventually into the negative terminal.

The conductors of DC wires are usually made of metal wires or conductive materials. They can be a single wire or multiple strands stranded together to form a single wire. Stranded wires improve the flexibility and elasticity of the conductor, making DC wires more flexible and durable.

In DC wires, the flow of current follows Ohm's law. According to Ohm's law, current (I) is equal to voltage (V) divided by resistance (R). Therefore, when the resistance of a DC line is smaller, a larger current can be transmitted. To reduce resistance, DC wires are usually made of materials with low resistance and the larger the cross-sectional area of the material, the lower the resistance. This explains why some DC wires have thicker copper conductors, because copper has a lower resistance and thicker wires have a larger cross-sectional area.

In addition, the length of the wire and the voltage variation are also considered in the working principle of DC wires. The greater the length of the wire, the greater the resistance. This means that thicker wires are needed to reduce resistance when carrying DC over long distances. Voltage variations can also affect the transmission of DC power. When the voltage varies greatly, the current may be lost, so measures (such as increasing the thickness of the wire or reducing the length of the wire) are needed to keep the voltage stable.

In summary, the operation of DC wires involves the transmission of DC current and the ability of the conductor to conduct the current. By correctly connecting the positive and negative terminals, electrons can flow through the DC wire and enable the transfer of current. In order to minimize the resistance to a greater extent and to keep the voltage stable, the conductors of DC lines are usually made of low resistance and sufficiently thick materials. At the same time, suitable measures are needed to reduce resistance and maintain voltage stability when transmitting DC over long distances.