Measurement of power quality indices in industrial networks

This paper presents results of power quality measurement in several industrial facilities. Voltage events introduce considerable economic losses and have the high impact on industry. From an economic point of view the frequency and duration of dips (sags) are very important because they can cause huge damage in industrial processes. The paper presents voltage dip distribution density function calculated from actual measurement data in the range of 15...30 % of the nominal voltage. Intention of authors is to show this statistical method which could be useful for assessing the total annual event.