Abstract:
The increasing integration of renewable energy sources (RESs) with
conventional energy sources units in a hybrid AC microgrid system has led to
the emergence of power oscillation damping (POD) controller for damping low
frequency oscillations (LFOs). A local microgrid has limited energy generation
capacity and may need to resort to load shedding during a power shortage.
Interconnected hybrid AC microgrid systems are essential for enhancing the
reliability and stability of power supply by allowing mutual support during
outages or power deficiencies. However, the integration of these subsystems
often results in oscillatory modes that could compromise stability and
operational efficacy. This thesis presents the design and implementation of a
multi-band power oscillation damping (MB-POD) controller implemented for an
interconnected hybrid AC microgrid system. The proposed MB-POD controller
aims to mitigate LFOs across various frequency bands, enhancing the overall
stability and reliability of the microgrid. LFOs are caused by integration of
generation sources, variety of dynamic load scenarios, and load disturbances in
any of the systems. These oscillations could take place locally or between
microgrids. This study introduces an energy storage system (ESS)-based POD
designed to mitigate such instabilities in an interconnected AC microgrid system.
This study also elucidates the complex dynamics of power oscillation in an
interconnected AC hybrid microgrid system, highlighting the deficiencies in
conventional power oscillation damping methods. Utilizing advanced
mathematical models and simulation techniques, we propose a novel approach
to dampen the oscillatory modes effectively. Using the proposed multi-band
damping controller as well as the extant single-band power oscillation damper
(SB-POD), interconnected hybrid AC microgrid system is intended to operate in
a
MATLAB/Simulink environment. Using time-domain simulations the
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proposed controller's performance is evaluated. Simulations and case studies
elucidate the damper's efficacy in enhancing system stability while optimizing
power flow and reducing the transient response time. The findings indicate
substantial improvements in damping multiple oscillatory modes by improving
the damping ratio from 9.1% and reducing oscillations by approximately 4-6%,
making it a promising solution for modern power systems. MB-POD than SB
POD across various microgrids, thus paving the way for more resilient and
adaptive interconnected hybrid AC microgrid system.
