posted on 2012-11-01, 14:16authored byShamsul A. Zulkifli
Currently, renewable energy sources are the main driver for future electricity generation. This trend is growing faster in the developed countries in order to reduce the green
house effect and also in response to the limited supply of oil, gas and coal which are
currently the major sources for electric generation. For example, the main renewable
energy sources are from wind energy and solar energy but these energies are only available to those countries that are exposed to these resources. In this thesis an alternative
energy source is investigated where it can be generated from the moving objects or in
form of kinetic energy. The idea is to convert the kinetic energy during landing aircraft
into electrical energy which it can also be stored and transferred to the existing electrical network. To convert this kinetic energy to electrical energy, the linear generator
(LG) and uncontrolled rectifier have been used for energy conversion. The LG have
been modelled in 3-phase model or in dq model and combined with the diode rectifier
that is used to generate the dc signal outputs. Due to the uncontrolled rectifier the
electrical outputs will have decaying amplitude along the landing time. This condition
also happen to the LG outputs such as the force and the power output. In order to
control these outputs the cascaded buck-boost converter has been used. This converter
is responsible to control the output current at the rectifier and also the LG output
power during landing to more controllable power output. Here, the H∞ current control
strategy has been used as it offers a very good performance for current tracking and
to increase the robustness of the controller. During landing, huge power is produced
at the beginning and when the landing time is increased, the generated input power
from LG is reduced to zero. Due to this, the energy storage that consists of ultracapacitor, bidirectional converter and boost converter are used in order to store and to
release the energy depends on the input power source and load grid power. The voltage
proportional-integral (PI) control strategy has been used for both the converters. The
last part is to transfer the energy from the source and at the ultracapacitor to the load
by using the inverter as the processing device. The power controller and current controller are used at the inverter in order to control the power ?ow between the inverter
and the grid. This is when the reference power is determined by the load power in order
to generate the reference currents by using the voltage oriented controller (VOC), while
the H∞ current controller is used to regulate the inverter currents in order to inject
the suitable amount of current that refer to the load power. Finally, a complete energy
recovery system for landing aircraft with the grid connection have been put together to
make the whole system to be as a new renewable energy source for the future electricity
generation.
History
School
Aeronautical, Automotive, Chemical and Materials Engineering