Question

Why is 132 kV used?

Answer 1

The use of 132 kV (kilovolts) in power transmission is primarily because it's an optimal voltage level for medium to long-distance transmission of electrical power. Here’s why this voltage is commonly used:

1. Efficiency in Power Transmission: Higher voltages like 132 kV allow electricity to travel long distances with lower losses. When electrical power is transmitted at higher voltages, the current decreases for the same amount of power (because power \( P = V \times I \)). Lower current means lower resistive losses (I²R losses) in the transmission lines, making the system more efficient.
   

1. Balancing Cost and Equipment: If the voltage is too low (like 11 kV or 33 kV), the current would need to be higher, leading to larger, more expensive conductors, which would increase both cost and energy loss. On the other hand, going much higher than 132 kV (like 220 kV or 400 kV) increases the cost of equipment (transformers, circuit breakers, insulators, etc.) and isn’t always necessary for medium-distance transmission. 132 kV is a good compromise between cost, efficiency, and distance.
   

1. Interconnection of Substations: 132 kV is also a common voltage for interconnecting various substations in the transmission network. It serves as a step-down voltage from high-voltage transmission lines (like 400 kV) to lower voltages (like 33 kV or 11 kV) that are then used to distribute power to end-users.
   

1. Regional Power Distribution: For regional transmission, 132 kV is often the most common choice as it can easily connect larger power stations to local areas without significant losses or cost implications.
   

In short, 132 kV is used because it provides a good balance between reducing transmission losses and managing the costs of equipment and infrastructure. It’s widely used in medium-range transmission between power stations and local distribution systems.