posted on 2023-07-04, 00:00authored byTossaporn Surinkaew
Forced oscillation (FO) events were detected in actual power systems,
i.e., Nordic and Western America power systems. These events could
result in the widespread blackout in the power systems. Accordingly,
intensive researches in the FO detection, source identi cation and mit-
igation are sought. In future power systems, conventional synchronous
generators will be replaced by converter controlled-based generations
(CCGs), i.e., wind and solar generations, and battery energy storage
systems. Thus, the paradigm shift in power systems will lead to the
inferior system strength and inertia scarcity. Therefore, problems of the
FO detection, source identi cation and mitigation will emerge with new
features of the CCGs.
To deal with the aformentioned problems, the following contribu-
tions are made in the thesis: i) a novel technique for detection of FO in
a power system when the measured signals received through the com-
munication channels are uncertain. Impacts of communication uncer-
tainties on measured signals are theoretically investigated based on the
mathematical models. Communication uncertainties are integrated in
the remote signal measurements for monitoring and controlling of the
FO. Theoretical investigation of the in uence of communication uncer-
tainties such as variable latencies, packet disorders and packet losses
on the FO analysis, and detection under several scenarios in a power
system, is conducted. The development of data recovery technique to
reconstruct the signal a ected by communication uncertainties is pro-
posed with the establishment of the technique of continuous detection
to improve the performance of the FO analysis and detection under vari-
ous operations and communication uncertainties, ii) the new design and
development of a controller termed as a forced oscillation damping con-
troller (FODC) for damping FO considering uncertainty and periodic
disturbances is proposed. An adaptive control algorithm is proposed
to adjust the control parameters of FODC under various system oper-
ations appropriately, uncertainties, and forced disturbances. Besides,
a new control design for simultaneous inter-area and FO damping is pro-
posed, iii) A uni ed FODC design method to deal with all oscillation
caused by non-stationary FOs is proposed. Mathematical analyzes of
the impacts of the non-stationary FO on electromechanical modes and
sub/super synchronous modes considering various scenarios are con-
ducted. The proposed solution consists of a continuous FO detection
and robust-adaptive FO mitigation. A modi ed continuous detection is
applied to monitor the non-stationary FO. Major stability indices such
as damping, frequency, interaction, and robustness can be calculated
without requiring exact system parameters, and v) A forced oscillation
management framework incorporating the hierarchical neural network of
distributed CCGs is proposed. Analyze and investigate the FO e ects
in a low-inertia MG with distributed CCGs are conducted under various
MG operating points, uncertainties, and FO conditions. The proposed
method is able to properly manage big data produced from DCRs and
suggest optimal solutions for FO detection, source identi cation, and
mitigation in a low-inertia MG with DCRs.
The simulation results show that the proposed methods in this thesis
can accurate detect the FO under communication uncertainties. More-
over, the proposed detection can di erentiate the FO from the elec-
tromechanical oscillations. The proposed damping controller can sup-
press both stationary and non-stationary FOs e ectively. Besides, the
proposed FO management framework with the hierarchical neural net-
work can detect and locate the FO source precisely, and suppress the
FO in a low-inertia microgrid with CCGs automatically.
History
Location
Central Queensland University
Open Access
Yes
Author Research Institute
Centre for Intelligent Systems
Era Eligible
No
Supervisor
Doctor Kianoush Emami ; Doctor Md Rakibuzzaman Shah ; Professor Mithulan Nadarajah