Approaches to Voltage Control in Distributed Generation-Enabled Nodes of Distribution Grids

One particular feature of distribution grids is that they have a substantial static stability margin in terms of active power in supervised grid segments. However, when the load curve deviates from the scheduled (projected) values due to a drastic change in weather or for other reasons, intolerably long emergency overloads may occur in the grid equipment. This paper proposes using an overload safety factor provided that the grid-wide load grows proportionally to the initial load; this measure will help prevent potential current overloads. It presents an approach to making adjustments to change in reactive load as active load grows at each step of parameter incrementation; further adjustments are made for different operating scenarios and for the load composition. The paper further substantiates the effectiveness of clustered voltage control of generator sets (GS) at distributed generation (DG) facilities within a single area. In order to calculate the steady-state parameters, one needs to take into account the available reactive power of the GS’s as dependent on the active power load and on the voltage. The paper investigates the effectiveness of shedding part of the active power load from a DG GS to load it in reactive power. It presents the parameter estimates that help estimate how GS load-shedding could affect the parameter incrementation capacity of the microgrid without jeopardizing the load and the grid.