Voltage dip is considered as the PQ problem related to the highest financial losses for the customers. It occurs unpredictably mainly due to short-circuit faults in the networks. Network operators and customers want to know more about the occurrence and the potential impact of voltage dips. PQ monitoring is an essential tool for the assessment of voltage dips and it can ultimately contribute to the regulation of voltage dip events. In this paper, firstly the methods of voltage monitoring and voltage dips characterization are discussed. Voltage dip indices of six substations are presented in order to assess the occurrence, type and severity of dips that occur in typical Dutch MV networks. Finally, an approach, which is based on the disrupted loads because of a voltage dip event, is introduced and applied to the data at one substation in order to assess the quality of supply voltage and its implications for the end-users. Index Terms-assessment of voltage dips, dip monitoring, reporting dips, transfer of dips, voltages dip indices

Voltage dips constitute to a noticeable part of power quality (PQ) problems but causing major financial losses to industrial and commercial customers. This work involves comparative studies to choose the most appropriate location of monitoring dips for regulation. In this paper, a Dutch MV network is used and dip monitoring locations are considered at different points of connections (POC) where customers are connected. To estimate the number of dips per year, simulations are performed on the network using PowerFactory. The voltage dip profiles at the selected monitoring point are analyzed for phase and line voltage dips. The effects of distributed generation (DG) on the voltage dips are also observed and the transfer of voltage dips from MV to LV network is briefly discussed. To analyze the effects of the expected dips on industrial equipment, severity curves are applied onto the standard dip tables.