Differential Protection: Further Steps

The beginning of differential protection, first solutions for stabilization due to saturation of measuring transformers and transformer taps were covered in the last issue of PAC World. The problem of reliability in case of external faults and the different behavior if working as line differential or transformer differential, the problem of inrush-detection, the usage of interposing transformers and zero-sequence current elimination have been an important topic since the 30s of the 20th century. The digital relays solved a lot of problems, but there are still some open issues. More

Let?s start with organization in protection testing