Electromagnetic Field-Based Control of Distributed Generator Units to Mitigate Motor Starting Voltage Dips in Power Grids

Direct online starting inrush current of induction motors results in voltage dip across the distribution network. The voltage sensitive loads that are connected to such networks tend to trip and disconnect from the networks during such voltage disturbances. There has been rising installation of rotary and static distributed generator DG units that include diesel generators, combined heat and power generators, small wind turbines, and solar photovoltaics. This paper presents control strategy to minimize the impact of induction motor starting on the network voltage using voltage feedback based reactive power support from the existing DGs. Simulation studies are presented to validate the theoretical framework. It is shown that DGs can restore the motor starting transient voltage dip quickly due to the fast response of the voltage controller designed for the DG.