Abstract:
For energy deficit countries like Pakistan, an optimal energy management program is
essential to make sure reliability in energy supply and discover energy saving
opportunities by minimizing costs related to generation and transmission of energy.
SCADA based management and supervision systems capitalize on the deployment of
the on hand power management facility by interactive review of the electrical power
network to check for system damages and outages.
This thesis has contributed in low cost development and implementation of a Remote
Terminal Unit (RTU) with provision of wireless connectivity with an aim to optimize
the energy management system based on SCADA. This particular design of RTU is
based on FPGA and its performance is better than commercially available RTUs
based on Programmable Logic Controllers (PLCs) and it is also well comparable with
other commercially available modern RTUs for power related applications. The
characteristics and features of developed RTU have been verified by means of
hardware testing. Moreover, a model for optimized energy management system was
also proposed and demonstrated by means of simulations. The provision of wireless
connectivity in the developed RTU has been optimized and benchmarking was also
done for further verification.
Initially, the modeling of the power system outages and the system adjustments using
contingency analysis using PowerWorld simulator is discussed which is followed by
consideration of optimal power flow (OPF) tool to determine effective system
corrections to execute in either the base case followed by a primary contingency or
any of the secondary contingencies. It also incorporates two major functionalities
namely Minimum Cost and Minimum Control Change which are available in OPF. It
is then supplemented by mathematical model for congestion management to prove
that the power flow can be affected not only by either varying voltage magnitudes or
the power angle but it can also be affected by changing reactance of the transmission
line. Therefore, either power angle or voltage magnitude may be used for congestion
management. An integrated framework has been proposed after the development of
model for power system outages and adjustments, OPF and mathematical model for
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congestion management. This framework can provide a simulation platform for
detailed study of power system to overcome issues like execution of restoration
scheme by adding renewable energy resources.
For development of RTU, a comparative assessment of performance of both
methodologies of RTU design is executed, one based on PLCs and other one based on
FPGAs which finalized for development of RTU due to its better performance and
reliability. The hardware implementation and verification of this RTU design is done
using a starter kit based on XILINX Spartan-3 Series FPGA with 500K logic gates
and the MHX-2400 frequency-hopping 2.4 GHz spread-spectrum communications
module which had been examined and found suitable as Communication Interface
Module for this development. The FPGA based RTU offers flexibility in terms of
I/Os, CPU and radio related configurations and expansion can be accommodated
quickly if needed as FPGA based designs are reconfigurable.
The design of link optimization has been implemented using Radio Mobile Simulator,
a well known simulation platform for point to multipoint link optimization. The data
transmitted from RTU is being received through Communication Interface Module for
data integrity and graphical representation for which further benchmarking is done for
Data Communication Protocol to further verify that the proposed solution is well
suited for optimized energy management in countries having shortfall of energy.
The implementation practical RTU hardware using FPGA include design
initialization, main system thread, design modeling and qualification, process
synthesis, programming of device and integration of communication interface module
(MHX-2400) which interfaced with Spartan 3E using header available on starter kit.
Finally, simulation of field inputs (variation in load) and control outputs (circuit
breaker and isolators) connected with RTU from test panels has been done in
hardware testing phase which allows sample inputs to be varied over the entire input
range using a Graphical User Interface (GUI) followed by the suggestions for future
work so that the research work may be extended to integrate new features and tools to
contribute in the developed RTU hardware.