What losses occur during electrical power transmission?

During electrical power transmission, losses occur mainly due to resistance, leakage, and corona discharge.

Electrical power transmission involves the movement of electrical energy from a power station to the end-user. During this process, several losses occur which reduce the efficiency of the system. The primary loss is due to resistance in the transmission lines. As current flows through the conductors, it encounters resistance which leads to the generation of heat. This heat is a form of energy loss, known as I^2R loss or copper loss. The magnitude of this loss depends on the resistance of the conductor and the square of the current flowing through it. Therefore, to minimise these losses, high voltage is used for transmission as it results in lower current for the same power. Understanding the properties of materials used in transmission lines, such as their resistivity and conductivity, is crucial in managing these resistance losses.

Another significant loss is due to leakage of current. This happens when current escapes from the transmission lines and flows into the earth. This is more common in underground cables where insulation may not be perfect. Leakage losses can be reduced by using better insulation materials and maintaining them properly.

Corona discharge is another source of power loss during transmission. This phenomenon occurs when the electric field around the conductor ionises the air around it, leading to the formation of a corona or a glowing halo. This ionisation process consumes a significant amount of energy, leading to power loss. Corona discharge is more prevalent in high voltage transmission lines and in conditions of high humidity or rain. It can be minimised by using conductors with larger diameters or by using bundled conductors. The basics of magnetic fields also play a role in understanding the electromagnetic aspects of power transmission, including the effects related to corona discharge.

Lastly, there are also minor losses due to the inductive and capacitive properties of the transmission lines. These are known as reactance losses. They are usually small compared to the other losses, but they can still impact the overall efficiency of the power transmission system. Efficient management and distribution of power across electrical grids are essential to mitigate these losses, as detailed in notes on power grids and distribution.

In summary, the main losses during electrical power transmission are due to resistance, leakage, and corona discharge. These losses reduce the efficiency of the power transmission system and are a significant concern in the design and operation of power grids.