A thesis which models the DNP3 and IEC 61850 protocol in OPNET / Supervisory Control and Data Acquisition (SCADA) is a critical part of monitoring and
controlling of the electrical substation. The aim of this dissertation is to investigate the
performance of the Distributed Network Protocol Version 3.3 (DNP3) protocol and to compare
its performance to that of International Electro-technical Commission (IEC) 61850 protocol in
an electrical substation communication network environment. Building an electrical substation
control room and installing the network equipment was going to be expensive and take a lot of
time. The better option was to build a model of the electrical substation communication
network and run simulations.
Riverbend modeller academic edition known as Optimized Network Engineering Tool
(OPNET) was chosen as a software package to model substation communication network,
DNP3 protocol and IEC 61850 Protocol stack. Modelling the IEC 61850 protocol stack on
OPNET involved building the used Open System Interconnection (OSI) layers of the IEC
61850 protocol stack onto the application definitions of OPNET. The Transmission Control
Protocol/Internet Protocol (TCP/IP) configuration settings of DNP3 protocol were also
modelled on the OPNET application definitions. The aim is to compare the two protocols and
determine which protocol is the best performing one in terms of throughput, data delay and
latency.
The substation communication model consists of 10 ethernet nodes which simulate protection
Intelligent Electronic Devices (IEDs), 13 ethernet switches, a server which simulates the
substation Remote Terminal Unit (RTU) and the DNP3 Protocol over TCP/IP simulated on the
model. DNP3 is a protocol that can be used in a power utility computer network to provide
communication service for the grid components. DNP3 protocol is currently used at Eskom as
the communication protocol because it is widely used by equipment vendors in the energy
sector. DNP3 protocol will be modelled before being compared to the new recent robust
protocol IEC 61850 in the same model and determine which protocol is the best for Eskom on
the network of the power grid. The network load and packet delay parameters were sampled
when 10%, 50%, 90% and 100% of devices are online.
The IEC 61850 protocol model has three scenarios and they are normal operation of a
Substation, maintenance in a Substation and Buszone operation at a Substation. In these
scenarios packet end to end delay of Generic Object Oriented Substation Event (GOOSE),
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© University of South Africa 2020
Generic Substation Status Event (GSSE), Sampled Values (SV) and Manufacturing Messaging
Specification (MMS) messages are monitored. The throughput from the IED under
maintenance and the throughput at the Substation RTU end is monitored in the model. Analysis
of the results of the DNP3 protocol simulation showed that with an increase in number of nodes
there was an increase in packet delay as well as the network load. The load on the network
should be taken into consideration when designing a substation communication network that
requires a quick response such as a smart gird. GOOSE, GSSE, SV results on the IEC 61850
model met all the requirements of the IEC 61850 standard and the MMS did not meet all the
requirements of the IEC standard. The design of the substation communication network using
IEC 61850 will assist when trying to predict the behavior of the network with regards to this
specific protocol during maintenance and when there are faults in the communication network
or IED’s. After the simulation of the DNP3 protocol and the IEC 61850 the throughput of
DNP3 protocol was determined to be in the range (20 – 450) kbps and the throughput of
IEC61850 protocol was determined to be in the range (1.6 – 16) Mbps. / College of Engineering, Science and Technology / M. Tech. (Electrical Engineering)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:unisa/oai:uir.unisa.ac.za:10500/27683 |
| Date | 14 July 2021 |
| Creators | Njova, Dion |
| Contributors | Ogudo, Kingsley, Umenne, Patrice |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | 1 online resource (xiv, 106 leaves) : color illustrations, application/pdf |
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