ABSTRACT
One of the most striking advantages of programmable digital protection devices is the ease with which logical conditions and relationships can be checked. Adaptive protection systems permit the protection functions to be adapted automatically in real time to changing power system conditions. The protection and control systems in a sub-station are a typical example which today exchange data in both directions. The signals are processed in accordance with the protection algorithms in the main central processing unit which then passes the results to the logic processor where they are related to other input signals and settings before being transformed into output commands for the process. Settings and the information concerning protection configuration are stored in EEPROM’s. The currents and voltages measured and possibly the real and apparent powers calculated from them can be viewed in addition to the settings and the responses of the protection device.
