Evaluation of Instigation of Voltage Sags by Distributed Generation with Anti Islanding Protection (AIP)

Khlil Ahmad

2018-2021

Master in Electrical Engineering

Summary

Because of momentary failure in normal operation or starting large loads the voltage drops from nominal value, named voltage dip or voltage sag. In continuous manufacturing sector, voltage dips are most significant source of influences. Voltage sag is the voltage drop between 0.1 p.u. to 0.9 p.u. The maximum severe influence of voltage sags is the abrupt and unpredicted interruption of manufacturing processes that can be the reason for significant economic damage to the customers fed by the distribution network. The surveys showed that average value of cost per dip event is almost thousands of euros. The voltage dip can also be created by integration of DG units that may be experienced by other customers as DG can take power from system for its operation. Such voltage sags occur after fault events, which are different from those caused by faults, or motor or transformer energizing. It investigates potential mitigation solutions (ENTM and PVDGM) by load flow to be adopted by the utility and/or by the DG owners.

Mini Distribution System

ENTM workflow

Importance & Application

Deduced method ensures the important procedures to choose, when there is a fault on any distribution system in expansion of DG. It ensures the voltage sag phenomenon in case of DG expansion. It also ensures the long-lasting time of voltage sag on the existing distribution system. Deduced method insured the value of voltage sag after disconnected DG and before operation of voltage regulator device. Deduced method guarantees the time delay setting for the voltage regulator to set up the first tap-movement. It also ensures the time taken for the voltage to get-back to its acceptable value after voltage sag is occurred. Deduced method ensures the voltage sag for the specific load type for any distribution system.

Strategy for the deduced method