Islanding detection and connection requirements

This paper reflects how anti-islanding protection has developed with increasing DG penetration. Starting from a local issue it has developed to possibly affect system security. The focus here is on how islanding detection methods and anti-islanding protection settings relate to distribution level and TSO requirements. It is confirmed using field measurements and simulations that the most common passive islanding detection methods cannot identify balanced island operation. Active methods can detect a balanced island, but is on the other hand not applicable to all DG units. Altogether it is motivated to reconsider anti-islanding protection taking into account the interests of all involved parties. Doing this reveals that anti-islanding protection based on power line carrier involving the distribution company may be the solution of the future.