Page 70 - Energize January 2022

TECHNICAL

Management of DER problems
SSEG problems can be dealt with by
smart control of VVO and CVR systems,
using LTR and reactive power devices as
well as smart inverters. Complex control
algorithms are sometimes required, and Figure 8: Effect of controls on voltage levels 2
many suppliers of distribution equipment
can offer such systems. An example of how A smart distribution grid can improve voltage control and reduce energy losses but
control can be applied is given in Figure 8. requires real time or near-real-time information on system parameters. This in turn requires
a high degree of interconnection between devices in the network.
Smart inverters and voltage control
A recent development is the use of smart References
inverters to assist with voltage control, 1. M Rycroft “Advanced metering infrastructure: The stepping stone to the smart grid”,
where the inverter is roped in to perform Energize, January 2021
a voltage control function in conjunction 2. J Watson: “Effectiveness of power electronic voltage regulators in the distribution
with other devices. In some networks, network”, IET Generation, Transmission and Distribution, August 2016.
smart inverters have become compulsory 3. D Kim and A Fischer: “Distributed energy resources and smart grids: an opportunity or a
as a VVO and VCR device. distraction?”, Energypost.EU, November 2021. https://energypost.eu/distributed-energy-
Whereas conventional inverters supply resources-and-smart-grids-an-opportunity-or-a-distraction/
only active power, the smart inverter can 4. T Mai, et al: “An overview of grid-edge control with the digital transformation”, Electrical
supply reactive power to control the voltage Engineering, 2021
level at the point of connection. Smart 5. B Green “Conservation voltage reduction and Volt VAR optimization in the Smart Grid”
inverters can also communicate with the EPRI 2011
distribution management system to provide
a co-ordinated voltage control system. Send your comments to rogerl@nowmedia.co.za

Image credit - Siemens

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