Efficiency
The ratio of useful power to absorbed power, often above 95 %.
Definition
A transformer’s efficiency is the ratio between the power it delivers at the secondary and the power it absorbs at the primary. Expressed as a percentage, it commonly reaches 95 to 99 % on power transformers, making it one of the most efficient electrical machines.
The difference corresponds to the losses: no-load losses (iron losses, constant) and load losses (copper losses, varying with the square of the current). Efficiency is therefore highest at an intermediate load, where these two families of losses balance out, and not at full load.
Good efficiency means less energy wasted as heat, hence lower operating costs and controlled heating.
The ABL tip
For a unit running continuously, a few percent of efficiency means significant savings over its lifetime. ABL Transfo can design high-efficiency transformers (premium laminations, oversized copper) when running cost is the priority.
