Kary Thanapalan

Adaptive Hybrid Maximum Power Point Tracking Method for a Photovoltaic System

Recently, the importance of exploring the plausibility of renewable energy has been progressively increased, not only because of concerns over the shortage of current fossil fuels but also the consideration of sustainable development and the negative environmental impact caused by large scale use of fossil fuels. Among renewable sources, solar energy seems to be one of the promising energy sources for widespread application. Due to its inherent intermittency and fluctuation, one of the important research interests is to harness the maximum power possible from the solar energy falling on a panel. To this end, an efficient maximum power point tracker to harvest as much energy as possible is a key to improving the systems efficiency and performance. This paper presents a novel hybrid maximum power point tracking mechanism with adaptive perturbation size. The proposed method is implemented, analyzed, and evaluated in MATLAB/Simulink. Both numerical and experimental evaluation results prove that by using the proposed method, better tracking performance can be achieved and the power delivered at steady state can be increased by a factor of 7.31% compared with conventional methods.

Review and analysis of fuel cell system modelling and control

This paper presents a review and analysis of a fuel cell system modelling and controller design for electric fuel cell vehicle applications. The paper begins by presenting the basic principal of PEM fuel cell dynamics. The work proceeds to investigate models and controller design techniques for fuel cell systems.

Modelling of a PEM Fuel Cell System

Abstract This paper considers modeling and simulation study of a fuel cell system. A mathematical model of a Polymer Electrolyte Membrane (PEM) Fuel Cell system is presented in this paper. For the convenience of presentation, cathode flow, anode flow, the membrane hydration, and voltage output expressions of the PEM fuel cell system are given in the paper to bridge a generic model to the model of Fuel Cell Test station (FCT). Within the University research facilities, there is a PEM – FCT station available so the PEM-FCT is used for the simulation study. Comparisons are made between the simulation results from the mathematical model which is implemented in MATLAB/Simulink and FCT test data. A general agreement exists but where there are differences and anomalies the paper gave reasons for this. Overall the PEM Fuel Cell (PEMFC) model represents the FCT station. The PEMFC model can be used for controller development to improve FCT system performance.

Fault Tolerant Controller Design to Ensure Operational Safety in Satellite Formation Flying

The paper addresses the problem of fault tolerant control design that has the same effect as implicit control system reconfiguration for satellite formation flying to increase operational safety as it is important for successful missions. Actuator and sensor degradation can be detrimental for formation precision in terms of satellite relative positions and attitudes. In this paper, model reference adaptive control (MRAS) and quaternion based adaptive attitude control (QAAC) is proposed as alternatives to fault determination and isolation. The adaptive systems approach is simpler as it avoids explicit modelling, decision making and control redesign. Redundancy based solution is used to protect against sensor deficiencies. Simulations illustrate the efficiency of the adaptive systems implemented for the control of the position and attitude of a single craft

Control-oriented PEM fuel cell system modeling and repetitive controller design

In this paper a control-oriented PEM fuel cell system model and a repetitive controller design strategy for PEM fuel cell systems is discussed. A mathematical model of a Polymer Electrolyte Membrane (PEM) Fuel Cell system is presented and then used to design the controller intended to improve system performance. The PEM Fuel cell is tested on an available test station (PEM-FCT) and the data used for the modelling and subsequent controller development study. For model validation a comparison is made between the results from a MATLAB/Simulink model and the test data from the PEM-FCT. The model is then used for repetitive controller design for the fuel cell system. Simulation results show that the repetitive controller tracks the reference signal very closely, with little deviation from the desired value.

Nonlinear controller design for a helicopter with an external slung load system

ABSTRACT This paper describes a nonlinear deterministic controller design for a helicopter with an underslung external load system. A robust control approach is considered for the control law development. The system is considered as a cascade connection of an uncertain nonlinear system. The controller is designed to ensure the stabilization of the helicopter system and the positioning of the underslung load at hover condition. Control analysis and numerical results show that the proposed controller is able to locate the load at the specified position or its neighbourhood.

Robust fuzzy controller development for a PEM fuel cell system

A polymer electrolyte membrane (PEM) fuel cell system model that is suitable for control study is presented in this paper. The PEM mathematical model is then used for the controller development to improve system performance. Within the university research facilities, there is available a PEM fuel cell test station (PEM-FCT), so the PEM-FCT is used for the modelling and controller study. A fuzzy set-point weighted PID controller is designed to improve the performance of the fuel cell system. The underlying idea of our controller design is to use a fuzzy based system to support the operation of a PID controller. The new control strategy is implemented on a PC based computer model of the FCT system and simulated. The results indicate that the control strategy has improved the system performance significantly. Thus, the new control strategy is implemented on PEM-FCT. Comparison made between the simulation model response and experimental results from the real FCT system using the same controller which shows performance enhancements, compared with the existing closed loop controller based on stoichiometry value updates to the flow controllers.

Agent Based Controller for Satellite Formation Flying

In this paper an agent based control scheme for satellite formation flying is discussed. The underlying idea of our design is to use a multi-agent architecture for satellite formation flying control. The architecture is designed to enable autonomous formation flying activities. The performance requirements and algorithms are described.

Comparative analysis of failure detection methods of composites materials’ systems

ABSTRACT This paper presents a review and analysis of current non-destructive failure detection methods of composite materials and a brief outline of the build of a bamboo bicycle which has been used as a development platform and test bed for the initial development of a novel and practical non-destructive failure detection solution, which has future compatibility for carbon-fibre (CF)-based bicycles. The paper begins by presenting the current market condition of composite materials and in particular, CF and CF-reinforced plastic, and then follows onto failure modes and proceeds to investigate a comprehensive range of failure detection methods.

Stability Analysis of a Helicopter with an External Slung Load System

This paper describes the stability analysis of a helicopter with an underslung external load system. The Lyapunov second method is considered for the stability analysis. The system is considered as a cascade connection of uncertain nonlinear system. The stability analysis is conducted to ensure the stabilisation of the helicopter system and the positioning of the underslung load at hover condition. Stability analysis and numerical results proved that if desired condition for the stability is met, then it is possible to locate the load at the specified position or its neighbourhood.