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In this paper, we design and simulate a Single-Ended Colpitts Oscillator (CO) in integer and fractional order domains. The oscillators are realized in 32nm node conventional MOSFET and carbon nanotube field effect transistor (CNTFET) technologies. Therefore, four COs have been designed, simulated and rigorously compared. These include integer order conventional MOSFET-based CO, fractional order MOSFET-based CO, CNTFET-based integer order CO and CNTFET-based fractional order CO, all based on 32-nm technology nodes. The fractional order approach has been used as it results in better control over the phase and frequency of the oscillator. Herein, fractional order capacitors of various orders, used in realizing the fractional order COs, are realized and their frequency responses are studied. This is being done to ensure whether the designed pseudo-capacitances have fractional behavior or not in the desired frequency and phase spectrum. It has been observed that the variation of fractional order (α) from 0.4 to 0.81 has resulted in a slight reduction of oscillation frequency from 1.68GHz (α = 0.4) to 1.351GHz (α = 0.81) keeping the pseudo-capacitance same at 0.3nF in MOS-based topology. Since the fractional order realization increases the circuit complexity and power consumption, therefore, CNTFET-based integer order as well as fractional order COs have been designed. The CNTFET-based fractional order CO retains the advantages of the fractional order domain as well as the power efficiency of CNTFETs. Further, it has been observed that integrating fractional-order capacitor (FOC) with the CNTFET CO results in a much larger constant phase zone (CPZ), an important performance measuring parameter. A rigorous comparative analysis of the four COs designed in this work has been performed. [ABSTRACT FROM AUTHOR]

Integration of photovoltaic (PV) power to the grid is achieved using three-phase inverters with high-quality current waveforms. The new grid codes impose a limit on the total harmonic distortion (THD) value of the inverter's current waveforms. Due to simple structure and ease of design, proportional integral (PI) controllers are the most widely adopted methods to control three-phase grid-connected inverters; however under abnormal grid conditions, PI controllers may suffer from instability problems. To address the aforementioned problem, this article proposes an expert knowledge-based proportional resonant (PR) control for the integration of PV power to the grid under abnormal grid conditions. The proposed control method adjusts the control parameters based on rules generated from expert knowledge. Initially, parameters of the proposed control methods are optimized using particle swarm optimization (PSO) method. The proposed control is tested with a 100 kW grid-tied three-phase inverter unit under normal and abnormal grid conditions and its performance are compared with PI and fixed gain PR control methods. Moreover, the proposed control is tested experimentally with a scaled down 300 W grid-tied inverter lab prototype module. From the simulation and experimental results, it is verified that the proposed adaptive PR control technique is capable of providing low THD in the injected current under abnormal grid conditions compared with fixed gained PR controllers. [ABSTRACT FROM AUTHOR]

Rogowski coils (RCs) are widely used to measure power or high frequency currents based on their design. In this paper, two types of RCs that are circular (traditional) and cylindrical shapes wound using wire covered by varnish are constructed. This construction is carried out to be suitable for monitoring the discharge current of the surge arrester installed in the distribution system. Concerning high frequency RC modeling for both types considering transfer function is introduced. Self-integrating for both types is attained. Therefore, the experimental tests using function generator for both coils are carried out to identify the parameters of the transfer function representing the introduced model. The measured signals for current and induced voltages are denoised for the parameter identification process. The denoised process is achieved using the MATLAB code 'wdenoise' while the parameters are estimated using the system identification toolbox. Verification of the proposed model is achieved using experimental results for the two coils. The sensitivity of the two coils is investigated based on the induced output voltage. The application concerning the two coils for monitoring the discharge current of the surge arrester is done. The results confirm the accuracy of the introduced RC model, as well as the performance of the cylindrical shape, is better than the traditional one. The simulation is carried out using MATLAB and ATPDraw programs. [ABSTRACT FROM AUTHOR]

Addition of lithium and manganese cations to borate glasses gives an essential enhancement of the dielectric properties. A strong challenge for energy storage devices is the high energy dissipation. Moreover, the ease of manufacture and the ability to control the glass composition make them significantly useful for a wide range of applications. Herein, borate glasses doped high polarizable BaTiO3 are synthesized by the melt-quenching method. The fully amorphous nature of all glasses is demonstrated. The density and molar volume are found to increase with increasing BaTiO3. The thermal stability study exhibits two glass-transition temperatures for the glasses containing BaTiO3. The most important optical parameters including band gap and Urbach energy are estimated. The BaTiO3-addition causes an initial reduction of band gap, however further addition makes the band gap wider. The activation energy for dc conduction is found to be between 0.98 and 1.07 eV. The dc conductivity decreases with incorporation of BaTiO3 due to the large sizes of barium and titanium ions compared to the size of boron ions, which reduces the ion mobility of the glasses. The influence of temperature, composition and frequency on the dielectric characteristics such as dielectric constant ε′, dielectric loss ε′′, loss factor tanδ and ac conductivity is investigated. The glasses of higher BaTiO3 content exhibit higher dielectric constant and lower dissipation factor (< 2%), which makes them excellent candidates for capacitors and energy storage applications. [ABSTRACT FROM AUTHOR]