power quality and reliability (smart grid) (PQR)

Power Quality and Reliability (PQR) is a characteristic value for the power quality and reliability of the power supply in low- voltage networks.

Power quality is determined by voltage fluctuations and short-term interruptions, transients, harmonics and electrical noise, and reliability by the continuity of electrical supply and the number and duration of power outages. The fewer there are and the shorter they are, the higher the reliability. In practice, certain indices are used for this purpose, through which the average value of the outages is calculated. These include the System Average Interruption Duration Index( SAIDI), the System Average Interruption Frequency Index( SAIFI), the Customer Average Interruption Duration Index( CAIDI), the Customer Average Interruption Frequency Index( CAIFI) and the Momentary Average Interruption Frequency Index( MAIFI).