Algorithm for Automatic Calculation of SAIDI and SAIFI Reliability Indices Based on Metering System Data

A 10–35 kV power distribution grid is considered, in which an automated information and measuring electricity metering system operates. It is assumed that the metering system head unit (instrument) contains data on the electrical network feeder’s and on the number of consumers (subscribers) connected to all of its outgoing lines. The head unit communicates with the feeder’s outgoing line meters that record the date, time, and duration of sustained (more than five-minute) interruptions of power supply to consumers. The appropriate meters transmit, on a monthly basis, data on power supply interruptions in the outgoing lines to the head unit, where the power distribution grid’s SAIDI and SAIFI reliability indices are calculated according to the developed algorithm. These reliability indices are automatically calculated according to the method outlined in IEEE Standard 1366™-2012, intended for use in modern information and measurement electricity metering systems. Computational experiments have confirmed the accuracy of calculating the SAIDI and SAIFI indices using the developed algorithm and calculation software. The study results are beneficial for both existing metering systems and those under development with SAIDI and SAIFI reliability indices monitoring functions. Such calculations can be used to determine and maintain the required level of power supply reliability of the power distribution grid consumers.