Development of a user-friendly, open-system software for the design and evaluation of protective relaying applications

In this paper, a novel modeling and simulation environment is developed that could serve as an aid to relay designers and manufacturers to evaluate their protective algorithms and hardware structures. Both relay performance and power system behavior are simulated in one unique environment. Each relay has all the common protective devices. Any protective device can be enable/disabled by the user. All the protective devices are collected and optimized in one unique S-function that emulates the actual relay. The relay operates in a dynamic manner and its status is visible on the screen. Advanced protective algorithms like thermal overload could be best tested and debugged by the developed environment. It allows evaluation of both individual protective devices as well as the interactions among them under a variety of power system operating conditions. The sampling interval is adaptively adjusted by the system frequency.