Today, artificial neural networks have reached the stage in which they can be used in the field of electrical network protection. Following a number of years spent in research and evaluation of these techniques, the authors have now decided to implement them in their product range. Transformer differential protection, which they thoroughly master in conventional digital technology, is currently undergoing developments using neural networks. The purpose of this paper is to describe this achievement, to show the performances obtained and to explain how neural network based techniques simplify commissioning and operation of the protection. (5 pages)