Study on assessment model of event-type power disturbances

This paper discussed the characteristics of power disturbances, and then proposed new classifying method. Disturbances are classified into two main categories, ldquocontinuous typerdquo and ldquoevent typerdquo. Continuous type disturbances typically include voltage deviation, power frequency deviation, unbalance, flicker and harmonics. Event type disturbances (ETD) include voltage sags (including short duration interruptions), outages, and transients. Based on the classification of power disturbances and traditional distribution reliability indices (SAIDI, CAIDI, SAIFI, CAIFI, and ASAI), Voltage sag indices coordinate interruption events indices were proposed: 1) SASDI and CASDI, 2) SASFI and CASFI. The comprehensive index ASAI*, a corrected ASAI, was defined based on SAIDI and SASDI coordinate of the economic losses of customers impacted by event type disturbances. The assessment model of ETD was proposed. The model represents the defined indices, the calculating procedure, the phase aggregation, and the time aggregation, which are four basic factors to rightly assessment power quality. A case study was used to testify the comprehensive method was reasonable and feasible.