Transformer design
Technical losses
Different voltage levels are used between the point at which a generator connects to the electricity network and the end consumer. A transformer is required to change the voltage level and it works on the principle that where it steps the voltage up, it will reduce the electrical current by a corresponding amount.
Transformers use electromagnetism to work as an efficient way to change voltage level. However, even the most sophisticated, expensive transformer will always have some associated losses. No transformer is 100% efficient. The transformer losses occur whenever the transformer is switched on and when it’s carrying and we call these fixed losses, as they are independent of the power that the transformer transfers.
Modern transformers are far more efficient than older ones, driven by increasing standards and thanks to improved design, developments in material science and better manufacturing processes. By replacing older transformers with modern equivalents, we reduce fixed losses. We can also install larger transformers to reduce their resistance and the associated variable losses. We replace lots of transformers as they age, or because they become overloaded as load grows. But whenever we replace a transformer for reasons related purely to losses, we have to ensure that the losses benefits that are delivered outweigh the cost of replacement.
