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Solar photovoltaic (PV) energy sources are rapidly becoming more popular. The PV system output power relies on the applied current or voltage nonlinearity and there exist a unique point called the maximum power point (MPP). For effective energy extraction from the PV system, this paper presents a new controller design strategy to track the MPP of a PV system using a sliding mode control method of self-optimisation. The proposed controller design offers fast and accurate convergence to the MPP in steady state and during varying environmental conditions. A DC/DC boost converter is utilised as a control actuator for the MPP tracking using PWM control. Simulation and experimental results are provided to demonstrate the validity of the proposed controller design. [ABSTRACT FROM AUTHOR]

Sliding-Mode Control (SMC) has been widely utilised to control nonlinear systems with uncertain dynamics. This is due to its order reduction properties, low sensitivity to disturbances, great dynamic performance and ability to reduce the complexity of feedback control design by decoupling the system into independent lower dimensional subsystems. Therefore, significant research has been dedicated to the application of SMC techniques to power electronic equipment and electrical drives. This paper presents a comprehensive control design procedure for AC/DC converters and DC/AC inverters based on SMC. It develops SMC algorithms for several types of power electronic equipment with different control objectives, complete and incomplete information about system states. A wide range of MATLAB/SIMULINK computer simulations are provided to demonstrate the effectiveness of the proposed control design. [ABSTRACT FROM AUTHOR]

In recent years, a lot of research efforts have been devoted to the application of sliding mode control (SMC) techniques to power electronic equipment and electrical drives. Hundreds of technical papers have been published in this research field. The tendency stems from the nature of sliding mode with discontinuous control actions and due to its potential for circumventing parameter variation effects along with low implementation complexity. This paper presents a control design procedure for DC/DC power converters. It develops SMC algorithms for several types of DC/DC converters with different control objectives, complete and incomplete information about system states. A chattering reduction approach for power converters based on the idea of multi-phase converters is also proposed. A wide range of MATLAB/SIMULINK computer simulations along with experimental results are provided to demonstrate the effectiveness of the proposed control design. [ABSTRACT FROM AUTHOR]

Zeolite faujasite (FAU), Linde type A (LTA) and FAU/LTA composite have been synthesized using tetramethylammonium cation (TMA+) as template, by adjusting only the concentration of Na+ ions in the initial solution (1.00 Al2O3 4.36 SiO2 : 2.39 (TMA)2O : β Na2O : 249.00H2O). Na+ ions alter the phase composition of the product more than TMA+ or OH- ions. When Na2O concentration [Na2O] increases from 0.024 to 0.168, the product gradually changes from pure FAU to pure LTA via the formation of FAU/LTA composite with increasing LTA fraction. Interestingly, the induction periods of FAU and LTA in the FAU/LTA composite zeolite ([Na2O] is 0.072) are both 13 h, quite different from the induction periods of their individual pure phases--45 h for FAU and 4 h for LTA. During the crystallization, the LTA/(FAU+ LTA) fraction in the composite zeolite decreases in a nearly linear fashion. Scanning electron microscopy, thermogravimetry and differential thermal analysis indicate some difference between the properties of the FAU/LTA composite zeolite and of the mechanical mixture. [ABSTRACT FROM AUTHOR]