Protection of embedded generation connected to a distribution network and loss of mains detection

The proliferation of dispersed embedded generation has become a fact, and is a real challenge for protection and control systems manufacturers. Indeed the existing offer is not really satisfying. The difficulty is to find the right balance to fulfil utilities requirements to ensure performances and security of the main network, and to offer the customer (the private producer) a comprehensive package easy to set that will eliminate all potential damage to the generators without nuisance tripping. The purpose of this paper is not to activate the debate about loss of mains (LOM) protection but to describe why the rate of change of frequency (rocof) protection is an efficient and safe solution. We describe settings to show how it could helpfully complete classical protections of the point of interconnection. On the other hand phase shift protection is considered from the point of view of a generator´s protection and compared to loss of synchronism function