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In General, the dispersed power supply system is possible to be robust and small compare with centralized power system. In the satellite system, we aim to downsize the power supply system by using the dispersed power system and cooperative control, which is constructed by solar panel and some bi-directional DCDC converters. In this paper, we describe the evaluation results for the behavior of the...
An islanding situation should be detected accurately soon after the island is formed. Because failure to trip the islanded distributed resource can lead to a number of problems for the resource and the connected load. Therefore, it is important to distinguish islanding and non-islanding situations and block the nuisance tripping effectively. This paper compares two islanding detection methods, during...
An environmentally friendly and low-friction bearing for applications such as tidal power generation is proposed using biomimetic technologies. A biomimetic bearing was successfully developed using a hydrated material, polyvinyl formal (PVF), which mimics articular cartilage in a natural synovial joint. A non-Newtonian fluid, polyethylene glycol (PEG) dissolved in distilled water, was used as a lubricant,...
A feasibiity study of solar power satellite (SPS) in-space transportation using a Hall thruster propulsion system was conducted based on cost evaluation. The transportation scenario was optimized through the cost evaluation: the choice of reusing or disposing orbit transfer vehicle (OTV), and power of propulsion system. From the result, the case of reusing OTVs was superior to the case of disposing...
Utility companies have been seeking methods to operate electricity distribution infrastructures efficiently. Smart grid applications provide opportunities to network operators to collect data from consumers. Therefore operators could track power consumption based on historical and immediate data. Thanks to remotely collecting data, operators take necessary action to manage changes in consumption rate...
As the penetration of electric vehicles increases the number of chargers for these vehicles are also increasing and therefore, will increase the electric energy grid consumption. To integrate these needs with the green energy, the use of electric chargers with a solar photovoltaic installation makes perfect sense. However, these charges can also be used for the support of the reactive power compensation...
The installation of micro generation systems on-board of electric vehicles is a solution that can contribute to improve the performance of this type of vehicles. Embedded generation systems increase the autonomy of electric vehicles and can reduce the number of times and duration of the recharging process of their energy storage systems. In this work, the influence of installing micro-generation systems...
With regard to spatial-planning aspects, the following can be said: analysis of the legal regulation and contacts established with government's institutions brought to the conclusion that spatial-planning requirements represent the most restrictive limitations for small hydropower plants construction. It should be particularly stressed that these requirements differ from one location to another, so...
The aim of this paper is to analyze dynamics of isolated electrical grid during short term interruptions. The effect of short term interruptions of the power supply on the characteristic values of synchronous generator in autonomous operation is analyzed. Dynamical loads (two induction motors), are connecting to the grid. Short-term interruptions that occur in different moments allow analyze of this...
Oxidative steam reforming of ethanol is an effective way to produce high yields of hydrogen. A novel series of pyrochlore-type metal oxide of La2Ce2−xNi0.5xO7−1.5x (x=0.1–0.9) was prepared and its catalytic performance was studied. All the materials were characterized by X-ray powder diffraction (PXRD), inductively coupled plasma atomic emission spectrometer (ICP-AES) and temperature-programmed reduction...
Telecommunication and data centers are moving to greener technology to minimize operating costs and lessen environmental impact. Ultimately, the networking and computing loads in these applications are DC rather than AC, and many renewable energy sources develop DC power as well. Energy storage systems are also DC, such as those required for Uninterruptable Power Supplies (UPS), as well as those needed...
This paper presents a mathematical analysis of a medium scale Photovoltaic (PV) power generation system connected to the distribution network and of its control system, in which the conversion stage is unique thanks to the absence of a boost chopper. Boost choppers are usually used as actuator for maximum power point tracking (MPPT). The conducted analysis leads to the conclusion that the used inverter...
The paper describes a procedure for identification of single machine infinite bus system. Mathematical model of synchronous generator is identified using data obtained from monitoring system. To determine the model parameters of the synchronous generator, a procedure based on Kalman filter was applied. The identified model of the synchronous generator can be used for parameter setting of the voltage...
This paper deals with the power efficiency improvement of the composite resonant DC-DC converter, which is developed to be applied to the power conditioner of the photovoltaic generation system. To improve the power efficiency, following three approaches are taken: 1) optimum design of the transformer 2) use of the voltage doubler rectifier. 3) reduction of the winding loss of the transformer. The...
Wind speed forecasting is required for ensuring an efficient utilization of the wind power generated by wind turbines. This paper purposes the short-term wind speed forecasting in a 2-dimesional input space using the developed k-nearest neighbor (k-NN) classifier. As well, the effects of the nearest neighbor number and the selected distance metric on the wind speed forecasting were analyzed and many...
A laser 2-focus velocimeter (L2F) has been applied for measurements of velocity and size of droplets in the dense region of diesel fuel spray under the atmospheric pressure condition. The fuel mass distribution in the spray obtained by the measurement was compared with the one simulated by using 3D-CFD code KIVA-3V. The radial velocity of spray droplets near the injector nozzle in the KIVA-3V code...
This paper presents a new control technique for a digitally controlled buck converter. In the proposed method predictive PID control is employed in order to improve transient response and margin of stability. The application of the proposed method is demonstrated for the prototype buck converter. The frequency response is discussed and the transient response is examined to confirm the performance...
In renewable energy systems such as the PV system, the batteries are connected to ensure a stable supply of energy. Therefore, the bi-directional power conditioners have a key role in renewable power systems. In this paper, bi-directional LLC resonant converter as the power conditioner is proposed. The ac analysis and operating characteristics of bi-directional LLC resonant converter are investigated.
This paper presents an experimental study with a hybrid microgrid system, which is proposed and implemented in the Tagajo campus of Tohoku Gakuin University, Japan. The developed microgrid consists of renewable power generations of PV and wind power generator, two types of energy storage devices of secondary battery and EDLC (Electrical Double-layer Capacitor), together with programmable DC load and...
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