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The purpose of this paper is to develop a novel microcontroller for grid-connected photovoltaic (PV) systems. As a prototype model, a 100-W-class module-integrated converter composed of the proposed controller and a flyback inverter has been built and tested. The prototype model is designed to satisfy the Japanese grid-connection guideline. Basic functions as those of a grid-connected PV inverter, such as the maximum-power-point tracking and the anti-islanding protection, have been confirmed in the experiments using a distribution network simulator located in a laboratory. This paper presents the description of the controller and the experimental results. A microcontroller has been developed with a 50-MHz-class microcomputer and simple interfaces. By revising the program, the proposed controller can be applied to various types of PV systems or grid-connected equipment. Index Terms--AC module, anti-islanding, grid connection, grid-connected photovoltaic (PV) inverters, islanding detection, maximum power point tracking (MPPT).

This paper studies the influence of the load type on the fault performance of the standalone Micro Grid (MG). Different load types (static and dynamic) are considered to show their effects on the standalone MG fault behavior. Specifically, the effects of constant power static loads, constant impedance static loads, and constant current static loads are analyzed. Also, effects of dynamic (rotating) loads are highlighted. Results show, that the rotating loads have dominant effects on the fault performance of the MG during the standalone (islanded) mode. Furthermore, rotating loads cause fault currents and touch voltages three times the values associated with the static loads. Consequently, the employed protective devices with the rotating loads MG must be rated three times larger than the employed protective devices with the static loads MG. Also, the time settings of the MG protection devices are highly influenced with the load type. For static load MG, it is equal to 250% of the rotating loads MG protection devices time settings. The three types of static load show different impacts on islanded MG fault performance. Constant power static load has the highest effect compared to the other two static load types (namely, constant impedance and constant current static loads). The results obtained in this study provide a guide for the MG protection designers and planners to consider the effects of load type on the MG protection devices rating and setting. [ABSTRACT FROM AUTHOR]

The necessity to solve global warming problems by reducing \CO2 emission in the electricity generation field had led to increasing interest in microgrids (MGs), particularly those containing the renewable sources such as solar and wind generation. Wind speed fluctuations cause high variations in the output power of a wind turbine which cause fluctuations in frequency and voltage of the MG during islanding mode and originate stability problems. In this paper, three techniques are proposed for solving and reducing the consequences of this problem. In the first technique, we develop a new fuzzy logic pitch angle controller. In the second technique, we design an energy-storage ultracapacitor which directly smoothes the output power of the wind turbine and enhances the performance of the MG during the islanding mode. In the third technique, storage batteries are used to support the MG in the islanding mode. [ABSTRACT FROM PUBLISHER]

In this paper, a generalized formulation for intelligent energy management of a microgrid is proposed using artificial intelligence techniques jointly with linear-programming-based multiobjective optimization. The proposed multiobjective intelligent energy management aims to minimize the operation cost and the environmental impact of a microgrid, taking into account its preoperational variables as future availability of renewable energies and load demand (LD). An artificial neural network ensemble is developed to predict 24-h-ahead photovoltaic generation and 1-h-ahead wind power generation and LD. The proposed machine learning is characterized by enhanced learning model and generalization capability. The efficiency of the microgrid operation strongly depends on the battery scheduling process, which cannot be achieved through conventional optimization formulation. In this paper, a fuzzy logic expert system is used for battery scheduling. The proposed approach can handle uncertainties regarding to the fuzzy environment of the overall microgrid operation and the uncertainty related to the forecasted parameters. The results show considerable minimization on operation cost and emission level compared to literature microgrid energy management approaches based on opportunity charging and Heuristic Flowchart (HF) battery management. [ABSTRACT FROM PUBLISHER]

This paper presents a new method for estimation of rotor surface losses in small-to-medium capacity synchronous machines. In this study, the authors have proposed a method for estimating the slot ripple losses induced on the rotor surface. Also, we compared the damper systems using the finite-element method and verified the results by the measured data. [ABSTRACT FROM AUTHOR]

Abstract: The devastating March 11, 2011 Earthquake (311 Earthquake) in northeast coast of Japan does not only result in a massive destruction to infrastructure, it also created power supply outage throughout the nation. Huge losses in nuclear power capacity and increasing awareness to nuclear safety have begun to cause changes in power system structure and energy policy in Japan. In this paper, we began by analysing the change of electricity generation before and after the 311 Earthquake. From the analysis, the electricity generation, Greenhouse gas (GHG) emission generation and CO2 intensity of Japanese electric utility industry in fiscal 2011 were calculated. These calculations have included the impact of the 311 earthquake. The result of the calculation has shown that by including the impact of the 311 Earthquake, 803.4 billion kWh of electricity with 371.15 million metric tons of GHG emission will be generated. The CO2 intensity of Japanese electricity generation will also increase from 0.417 kg-C02/kWh to 0.462 kg-C02/kWh in fiscal 2011. In another word, if the Japanese electric utility industry would like to achieve the emission reduction target under Kyoto Protocol even after taking the 311 Earthquake into consideration, it would need to further reduce about 114.06 million metric tons of GHG emission. [Copyright &y& Elsevier]

Abstract: Wind energy has emerged as the most attractive solution to the world''s energy challenges. The possibility of locating wind turbines in the sea bed has opened up a new frontier for wind power, especially in the countries of northern Europe, where the availability of relatively shallow coastal waters has combined with the need to find space for much larger projects than are possible on land. In this paper begins with an exploration of the importance of wind power in today''s energy-hungry in Japan. In this paper looks at the basics of the off-shore wind power industry, how a wind turbine works, analyzing and understanding the technologies involved in harvesting off-shore wind power, economical analysis of off-shore wind power, and much more. Economics, issues and barriers, regulatory incentives, tax incentives, and other such factors related to off-shore wind energy also explored in-depth in this paper. As our calculation results show, the generation cost is within 10 to 17 Japanese Yen/kWh and construction cost is within 139,445 Japanese Yen/kW to 240,366 Japanese Yen/kW which revealed the applicability of off-shore wind power in Japan. [Copyright &y& Elsevier]

Power deregulation and shortage of transmission capacities have led to increased interest in distributed generators, especially renewable sources. In this study, a complete model is developed that can simulate in detail the transient dynamic performance of the micro-grid during and subsequent to the islanding process. Wind speed fluctuations cause high fluctuations in output power of a wind turbine, resulting in fluctuations in frequency and voltages of the micro-grid during islanding mode. In this study, new proportional integral pitch controller is proposed to smooth the output power of a wind turbine to reduce frequency and voltage fluctuations. The proposed proportional integral controller is compared with the conventional proportional integral controller that is used for wind turbine power control. The obtained results proved that the proposed controller is effective for the improvement of micro-grid performances. In addition, a neuro-fuzzy controller is also proposed for obtaining maximum power point tracking of the photovoltaic panels installed in the micro-grid. All models and controllers are developed on a Matlab® Simulink® environment. [ABSTRACT FROM AUTHOR]

A series of 3-aryl-4-hydroxycyclobut-3-ene-1,2-diones were synthesized and examined as sensitizers for a TiO2 solar cell. The compounds showed strong affinity for TiO2 and the fluorescence intensity and self-assembly of the 3-aryl-4-hydroxycyclobut-3-ene-1,2-diones on the TiO2 surface were important factors in enhancing the solar-light-to-electricity conversion efficiency. The highest efficiency of 0.96% was observed for 3-[4-(didodecylamino)phenyl]-4-hydroxycyclobut-3-ene-1,2-dione. [Copyright &y& Elsevier]

Abstract: The need of reducing CO2 emissions in electricity generation field for solving global warming problems has led to increase interest in Micro-Grid (MG) especially the one with renewable sources such as solar and wind generations. Wind speed fluctuations cause high fluctuations in output power of wind turbine which cause fluctuations in fr and voltages of the MG in the islanding mode and originate stability problems. In this study, a new fuzzy logic pitch controller and an energy storage ultra capacitor are proposed and developed to smooth the output power of wind turbine and enhance MG''s performance in islanding mode. These two proposed controllers are compared with the conventional PI pitch controller, which is usually used to control wind generation system when the wind speed exceeds a rated value. Obtained results proved that our two proposed strategies are effective for the MG performance improvement during islanding mode. All models and controllers are developed using Matlab® Simulink® environment. [Copyright &y& Elsevier]

We devised new body shape silhouettes to more accurately reflect Japanese body sizes. Our aim was to assess the association between measured body mass index (BMI) and body size through self-selection of nine figure scales. This study was comprised of 4808 men and 1093 women aged 35-71 years. Subjects were asked to identify the silhouettes that most accurately represent their current body size. BMI was calculated from measured height and weight based on annual health checkups. Spearman's correlation coefficients between silhouette ratings and BMI were 0.73 in men and 0.80 in women. Moreover, mean BMIs increased in value with increasing silhouette numbers in both genders (trend p < 0.01 for both). Simple linear regression models predicting BMI based on silhouette ratings showed a good fit, with silhouette self-selection statistically explaining 54.0% of BMI variance in men and 62.5% in women. Receiver operating curves showed that areas under the characteristics curves were higher than 0.8 for obesity and thinness in both genders. These findings suggest that our scale is a promising tool for examining body size and image among Japanese adults.