ABSTRACT
Microprocessor digital protective relays (DPR) are extensively displacing all other types of relay protection devices from the market since all the world leaders in this area have almost completely ceased production of all other types of protection relays for the electric power industry. There are hundreds of DPR models made by dozens of manufacturers in the market. Each type of DPR is built in a separate body, which may be totally different from that of any other type of DPR. The popular way of increasing the hardware’s reliability as backup is also problematic due to the high cost of DPRs and the shortage of resources to reequip the basic set of protections apart from the backup set. The full incompatibility of DPR software, sometimes even between different versions of the same program, results in another problem hampering the use of DPRs.
