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Industry Applications Society Annual Meeting (IAS), 2012 IEEE

Date 7-11 Oct. 2012

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Displaying Results 1 - 25 of 148
  • Open door arc flash calculations related to closed-door applications

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1329 KB) |  | HTML iconHTML  

    NFPA 70E defines Incident Energy Analysis as “A component of an arc flash hazard analysis used to predict the incident energy of an arc flash for a specified set of conditions.” Conditions presently specified are for hazards that exist when energized electrical conductors or circuit parts are exposed. From a letter of the law perspective, address of closed door Arc Flash hazards requires either the use of a calculation for other than specified conditions or use of equipment for a purpose for which it lacks certification. Practically, combining information from existing calculations with knowledge of existing equipment certification testing can improve understanding of closed door hazards. As a starting point, calculated calories per centimeter squared are translated into equivalent force. Similar conversions are applied to energies of standard device functions such as interruption of available fault currents. Estimated forces are then compared to present enclosure certifications to produce expected closed door hazards based on present incident energy analysis techniques. View full abstract»

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  • Interpole-type magnetic actuator for navigation of magnetic drug

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (993 KB) |  | HTML iconHTML  

    This paper presents the interpole-type magnetic actuator for navigation of magnetic drug. In the proposed magnetic actuator system, the magnetic actuator generates the magnetic field to magnetize the magnetic drug, and then the magnetic force is induced on the magnetic drug. However, the magnetic force is enhanced by increasing the phase current. Therefore, the interpole-type actuator is proposed in order to reduce the phase currents while increasing the magnetic force induced on the magnetic drug. Using the finite element method (FEM), the magnetic field of the magnetic actuator is analyzed to calculate the magnetic force induced on the magnetic drug. Finally, the prototype of the proposed interpole-type actuator for the magnetic actuating system is implemented to verify that the magnitude of the magnetic flux-density vector in the proposed interpole-type actuator is greater than that in the conventional actuator. View full abstract»

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  • VFD machinery vibration fatigue life and multi-level inverter effect

    Page(s): 1 - 15
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2721 KB) |  | HTML iconHTML  

    The paper documents fatigue related mechanical failures in variable frequency drive (VFD) motor machinery due to mechanical vibrations excited by drive torque harmonics which are created by PWM switching. Present effort models the coupled system with full electrical system including rectifier, DC bus, inverter, motor, and an industrial mechanical system including flexible couplings, gearboxes and multiple inertias. The models are formed by a novel combining of a commercial motor code with a general, self-written mechanical code. The approach extends failure prediction beyond simple occurrence of resonance, to fatigue life evaluation based on Rain-flow algorithm, which is suitable for both steady state and transient startup mechanical response. The second contribution is a demonstration that the common use of multilevel inverter to reduce voltage/current harmonics may actually exacerbate resonance and fatigue failure. This is shown to be caused by a resulting amplitude increase of torque components in proximity to potential resonance frequencies. View full abstract»

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  • Integrated diesel engine emission control using plasma combined hybrid system

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (671 KB) |  | HTML iconHTML  

    Innovative diesel particulates (PM) collection and NOx reduction technology were developed using plasma combined system over the ears. As for PM control, the EHD-assisted electrostatic precipitator (EHD ESP) to collect low resistive diesel PM and the plasma ESP to collect and incinerate PM were developed. As for NOx reduction system, NOx concentration, followed by nitrogen plasma was developed without using catalysts or ammonia used for selective catalytic reduction (SCR). The integrated diesel engine emission component reduction system consists of electrohydrodynamically assisted electrostatic precipitator (EHD ESP), plasma ESP, NOx concentration followed by nitrogen plasma, reactive species injection for NOx and PM reduction, and NOx recirculation EGR system. Each component technology was evaluated and optimized to meet the desired diesel emission control. The integrated plasma combined hybrid system leads to extremely economical and practical NOx removal system. View full abstract»

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  • Investigation of humidity effect on atmospheric plasma decomposition of toxic gas with direct optical measurement of OH radicals

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (291 KB) |  | HTML iconHTML  

    Plasma application for environment improvement is desirable. In order to improve the efficiency of toxic gas decomposition by plasma, it is worthwhile to clarify the behavior of radicals in non-thermal plasma. Although previous studies have revealed the behavior of radical densities and temperatures in atmospheric discharge, they are not yet connected to apprehension or simulation of practical toxic gas decomposition by atmospheric plasma. In this study, the coaxial dielectric barrier discharge (DBD) cylinder reactor is prepared, where the radical behavior and toxic gas decomposition efficiency can be measured all together. The density and temperature of OH radical are directly measured by laser-induced fluorescence (LIF), and trichloroethylene (TCE) decomposition efficiency is also investigated. OH density measurement indicated that OH density is about 20 ppm at 3 μs after discharge when 28 kV is applied. Besides, the acceleration of OH decay with increasing TCE is observed, which indicates that OH reacts with TCE. On another front, TCE decomposition efficiency by AC DBD is also investigated in the same reactor. With the characteristics and humidity dependence of OH behavior measured above, we can simulate TCE decomposition efficiency dependence on humidity. View full abstract»

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  • Measurement of OH radical in the effluent of an atmospheric-pressure helium plasma jet

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (748 KB) |  | HTML iconHTML  

    Atmospheric-pressure helium plasma jet is getting much attention especially in plasma medical application or dental application. It is thought that active species play important role in the plasma processes and they are generated from the interaction between the plasma and molecules included in the ambient air and the discharge gas. OH radical is one of the most important active species. However its production mechanism is not yet elucidated completely. In this study, OH density distribution in the vicinity of dry and wet surface in the effluent of an atmospheric pressure helium plasma jet was measured by using laser induced fluorescence (LIF). OH density and its distribution varied depending on some parameters; helium flow rate, gap between the surface and the end of capillary tube and humidity of the objective surface. The maximum OH density was approximately 1.0 ppm in the case of the plasma jet extending toward wet surface when high voltage 10 kV, 8 kHz was applied. The result suggests that OH radical is produced by the dissociation of H2O nearby the surface that evaporates from the surface or adheres on the surface. View full abstract»

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  • Electrically enforced condensation related to effects of the corona discharge

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (457 KB) |  | HTML iconHTML  

    The effect of corona discharge in the steam on the rate of nucleation and condensation of the liquid phase is investigated theoretically and experimentally in means of implementation with the steam condenser for the improved phase-change rate. The considered phenomena include the nucleation of water vapor on mobile charge carriers, the electrohydrodynamic vapor flow toward the condenser wall and the thermodynamics of the charged micro-droplet. The prototype of the device is built and investigated. Obtained results confirm the improvement in the condensation rate. View full abstract»

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  • Characteristics of corona discharge from multi-pin electrodes

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (489 KB) |  | HTML iconHTML  

    The GMR head in the tape recording is suffered from the corona discharge generated by tribo-electrification. In order to estimate the reliability of the head materials, the corona discharge using multi-pin electrodes was studied. The multi-pin electrodes were configured with maximum 15 pins. Each pin was distanced 5mm from neighbors and placed at 11mm over the Al plate. At negative voltage, the discharge started with isolated pulses. As the voltage increasing over -7kV, DC component appeared and increased. At positive voltage, the discharge was isolated pulses up to +10kV and DC component did not appeared. At 15-pins electrode, the period between the pulses was random and the peak values varied. Therefore, the corona discharges from the multi-pin electrodes occurred individually at each electrode. The mean current of 15-pins increased approximately five times at negative voltage and twenty times at positive voltage compared with that of single-pin. View full abstract»

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  • Enhancement of plasma bacterial inactivation by ferric iron supplementation

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (725 KB) |  | HTML iconHTML  

    In the present paper, we report results on the plasma bacterial inactivation in the presence of ferric ions, added to the Fenton reaction medium. Fenton reaction is a catalytic reaction of hydrogen peroxide conversion into a highly reactive hydroxyl radical in the presence of ferric ions. Non-thermal plasma jet was used as plasma source, and Escherichia coli (E. coli) was used as bacterial sample. Ferric sulfate was used as source of ferric ions. Inactivation experiments to E. coli suspension added ferric sulfate were carried out. First, effect to survival rate caused by ferric sulfate and magnesium sulfate were compared. Magnesium sulfate contains divalent metal ion without Fenton catalytic activity. Only ferric sulfate enhanced inactivation effect. Then, experiment with ferric sulfate at various concentrations was carried out. In result, the enhancement of inactivation was confirmed at the optimum concentration. Though, ferric sulfate in concentration higher than optimum level rather suppressed inactivation effect. The enhancement was not reproduced by addition of hydrogen peroxide in concentration similar to sample after plasma treatment. In conclusion, addition of ferric sulfate in optimum concentration can enhance inactivation effect. It can be expected as new control technique for non-thermal plasma bacterial inactivation. View full abstract»

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  • Analysis of the inactivation mechanism of bacteriophage ⊘X174 by atmospheric pressure discharge plasma

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (406 KB) |  | HTML iconHTML  

    Inactivation technology of viruses by atmospheric pressure discharge plasma has been studied actively. However, the predominant factor in the inactivation is still unclear. Bacteriophages, consisting of only nucleic acids and coat proteins, are suitable for the study of the inactivation mechanism due to their simple structure. In this study, inactivation of bacteriophage φX174, which is resistant to drying stress and has some characteristics similar to influenza virus, was investigated using dielectric barrier discharge (DBD) or corona discharge. We exposed wet or dry bacteriophage φX174 to discharge plasma. It is possible to extract the nucleic acids from the bacteriophage and to assay its plaque forming activity by transfection. Therefore, the damage given to the DNA can be separately analyzed. The coat proteins were also analyzed. Both DNA and coat proteins of plasma-treated φX174 phage were damaged, however, the damages of coat proteins were more significant compared to the DNA damages. View full abstract»

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  • Electroless nickel plating on fluoroplastics films using atmospheric pressure nonthermal plasma graft polymerization process

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4000 KB) |  | HTML iconHTML  

    Electroless nickel plating and photolithography on a fluoroplastics film, which is treated by atmospheric pressure nonthermal plasma graft polymerization, is investigated. Fluoroplastics such as PFA (perfluoroalkoxy fluoroplastics) and PTFE (polytetrafluoroethylene) are extremely stable, inactive, and hydrophobic. Therefore, it is difficult to apply them to electric circuits without surface treatment. In this study, a low-environmental load surface modification of a PTFE film using an atmospheric nonthermal plasma graft polymerization device that can treat A4-size sample is performed. In addition, electroless nickel plating and photolithography on the treated PTFE film are achieved successfully. View full abstract»

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  • The electric power generation at low temperature gradients

    Page(s): 1 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (471 KB) |  | HTML iconHTML  

    The thermoelectric efficiency of the ion-conductive materials is investigated as the energy harvesting from heat wastes or wide-spectrum solar radiation. The physical model for the phenomenon is developed and experimental results are analyzed in means of practical implementation with power conversion at temperatures near the ambient. This analysis addresses the thermoelectric efficiency, the power conversion efficiency and options for the practical implementation. View full abstract»

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  • DC ionizer using opposed φ-type corona electrodes for high speed charge elimination

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    A corona type ionizer is a device that supplies air flow including positive and negative corona ions for the elimination of electrostatic charges on a charged target. DC ionizers placed close to the charged target are proposed to shorten the charge elimination time and decrease the remaining voltage. The ionizer is composed of a grounded mesh electrode and opposed positive and negative needle electrodes. The opposed φ-type electrodes are also tested to improve the performance. A strong electric field can be formed between the grounded mesh and the charged target; therefore, the ion drag force due to the electric field become dominant and plays an important role in charge elimination with this technique. A charge elimination model using a simplified charge elimination current is also proposed to evaluate the performance of the ionizers. The charge elimination performance of the ionizer using opposed φ-type electrodes was much better than that using opposed needle electrodes, due to the increase in the positive and negative charge density, which increases elimination of the target charge. View full abstract»

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  • Measurement of atmospheric ionic current

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (718 KB) |  | HTML iconHTML  

    Known as the global circuit, air-earth conductive current or atmospheric ion current (AIC) is flowing into the ground. In this study, the result of continuous measurement of AIC has been presented, with possible relation with major earthquakes. The AIC flowing into an electrode on the roof has been measured as a potential by using a high input impedance electrometer. As a result, typical daily change in Vm in fair weather showed a very small value after sunset until sunrise. It then gradually increased with time reaching a peak around noon followed by a gradual decrease to a very small value in the evening. Since it has been reported that the AIC is affected by solar radiation, normal daily variation of Vm should be mainly due to the AIC. To analyze a correlation between the observed potential and AIC, time-course of the potential was analyzed. From the potential observation before and after the huge earthquake occurred on March 11th 2011 in Japan, two types of signals of AIC clearly and significantly different from normal one mentioned above were observed. One is high potential in midnight started to be observed about 10 days before the earthquake occurrence and the other is large burst pulses observed a few hours before the earthquake. Because the abnormal behavior of the measured AIC was observed before some other large earthquakes, it can be ascribed to crustal movement such as preslip. Further study and international joint measurement of AIC is necessary to study the correlation between AIC and earthquake. View full abstract»

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  • Effect of electric field generated by micro-scaled-electrode on pool boiling

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3074 KB) |  | HTML iconHTML  

    This paper describes results from an experimental study of the effect of an electro-hydro-dynamics (EHD) and of an electrostatic force on the critical heat flux (CHF) in pool boiling. Dielectric liquid of HFE-7100(3M), which has a boiling point of 59.8°C, was selected as a working fluid. In order to generate high electric fields with the application of low voltages, a micro patterned electrode with an array of planar comb finger was made by micro-electro-mechanical-systems (MEMS) technology. The electrode had ten slits whose width was 400μm between electrode pairs so as to remove vapor bubbles from a heat transfer surface by the electro static force. A cooling device fabricated with the electrode was evaluated by different applied voltages. As a result, the application of voltage enhanced heat transfer. View full abstract»

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  • Smart Home Precipitator for biomass-furnaces: Design considerations on a small scale electrostatic precipitator

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (798 KB) |  | HTML iconHTML  

    With use of wood pellets becoming more popular for heating in private households, an increase in particulate matter problems across urban areas has been detected. As this contributes to significant health risks, effective reduction of dust emissions will become mandatory even for comparably small heating systems. The Smart Home Precipitator (SHPP) was designed for this scope of application. This document demonstrates the development steps aiming at a cost-effective precipitator that can be used for central heating processes up to 30kW. It starts with research on the mechanical design and on the collection efficiency for the development of a space saving structure with comparable large collection area. In a next step two different circuit topologies for the high voltage power supply have been analyzed. The latest and final work step in the design phase was the development of a smart and efficient control algorithm using fuzzy logic for dynamic optimization. View full abstract»

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  • Preliminary implementation of microgrid with photovoltaic and microturbine for stand alone operation

    Page(s): 1 - 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (510 KB) |  | HTML iconHTML  

    This paper presents the preliminary implementation of microgrid system with photovoltaic and microturbine for stand alone operation. The microgrid test bed of the Institute of Nuclear Energy Research (INER) in Taiwan is selected for the study of impacts of high concentration photovoltaic (HCPV) and microturbine to be installed. The one line diagram of the microgrid is constructed and actual load profile supplied by the microgrid is collected. Based on the direct normal irradiation (DNI) and the corresponding power output of HCPV, the voltage variation of microgrid with a microturbine is solved according to the power flow analysis. Besides, the fault currents introduced from HCPV, microturbine and Taipower system are calculated to design the protection coordination of the microgrid. Three actual filed tests of the microgrid have been conducted to verify the effectiveness of the transition operation between grid connect and stand alone control of the microturbine. To verify the normal operation of HCPV, a fault contingency at the external utility system followed by the motor starting in the microgrid is simulated by computer software program. From the simulation results, it is concluded that the transient stability of the INER microgrid for stand alone operation can be guaranteed by installing a microturbine. View full abstract»

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  • A novel hybrid approach based on wavelet transform and fuzzy ARTMAP network for predicting wind farm power production

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB) |  | HTML iconHTML  

    This paper presents a novel hybrid intelligent algorithm based on the wavelet transform (WT) and fuzzy ARTMAP (FA) network for forecasting the power output of a wind farm utilizing meteorological information such as wind speed, wind direction, and temperature. The prediction capability of the proposed hybrid WT+FA model is demonstrated by an extensive comparison with a benchmark persistence method, other soft computing models (SCMs) and hybrid models as well. The test results show a significant improvement in forecasting error through the application of a proposed hybrid WT+FA model. The proposed hybrid wind power forecasting strategy is applied to real life data from Kent Hill wind farm located in New Brunswick, Canada. View full abstract»

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  • Particle Swarm Optimization based non-intrusive demand monitoring and load identification in smart meters

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (739 KB) |  | HTML iconHTML  

    Comparing with the traditional load monitoring system, Non-Intrusive Load Monitoring (NILM) system is simple to install and does not need individual sensor for each load. Accordingly, the NILM system can be applied for wide load monitoring and become a powerful energy management and measurement system. Though several NILM algorithms have been developed during the last two decades, the recognition accuracy and computational efficiency remain challenges. To minimize the training time and improve recognition accuracy in Artificial Neural Networks (ANNs), a Particle Swarm Optimization (PSO) is adopted in this paper to optimize parameters of training algorithm in ANN to improve NILM accuracy. Case studies are verified through the combination of Electromagnetic Transients Program (EMTP) simulations and field measurements. The results indicate that the proposed method significantly improves the recognition accuracy and computational speed under multiple operation conditions. View full abstract»

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  • MPPT photovoltaic wide load-range ZVS phase-shift full-bridge charger with DC-link current regulation

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (670 KB) |  | HTML iconHTML  

    In this paper, a maximum-power-point-tracking (MPPT) photovoltaic wide load-range zero-voltage-switching (ZVS) phase-shift full-bridge (PSFB) charger with DC-link current regulation is developed in order to obtain high-efficiency power conversion even at light load condition. According to the output characteristics of the solar cell module, the proposed MPPT photovoltaic converter can be implemented with available analog control ICs on the market. Besides, by regulating the DC-link current for the post-stage PSFB charger, the wide load-range ZVS condition of the employed power switches can be ensured. Finally, the prototype circuit of the proposed photovoltaic wide load-range ZVS PSFB charger is built to verify the power conversion efficiency and MPPT efficiency at wide load range. View full abstract»

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  • A energy-savings evaluation method to justify automatic power factor compensators on marine vessels

    Page(s): 1 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1661 KB) |  | HTML iconHTML  

    Many induction motors are installed in ship electric power systems, where a poor power factor is often overlooked. Power factor compensation that is usually achieved by adding capacitive load to offset the inductive load present in the system can have many benefits. As a ship power system, fuel oil costs and air pollution emissions for power generation remain low. This paper aims to establish a set of energy-savings evaluation model for benefit-cost analysis for automatic power factor compensators (APFCs) applied in marine vessels. The active power, reactive power, power factor, and diesel electric engine's oil consumption for a practical commercial vessel power system during different operating conditions were measured and analyzed. Base on the actual measurements, an APFC for marine use is designed and the possible benefits after installing the APFC are quantified to justify the investment by using two standard cost-benefit analysis methods. Sensitivity analysis is also performed to reduce effects of input parameters on the analysis results and determine the critical parameters. Analysis results can assist shipbuilding corporations and ship owners in managing energy efficiency of similar systems and building business cases for determining return on investment (ROI). View full abstract»

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  • Energy-efficient electronic light sources for marine vessels

    Page(s): 1 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB) |  | HTML iconHTML  

    Traditional marine lighting with low efficiency has been gradually replaced by high-efficiency electronic lighting equipment. However, these electronic lighting equipment are mainly for land use, and ignore unique lighting requirements of marine use, such as, temperature, vibration, etc. To confirm the applicability of land-use electronic light sources in a marine environment, several existing commercial electronic lamps are selected in this paper to replace traditional on-board light sources and then land and on-board tests are conducted according to maritime lighting regulations for comparison with traditional light sources in terms of performance. According to information in the test results, in response to the introduction of electronic lamps, existing ship lighting rules should be appropriately strengthened in terms of lighting and vibration test requirements. Meanwhile, general land-use electronic lamps should be strengthened with respect to vibration and lumens depreciation due to engine room environment. The analysis results can assist shipyards and ship owners in the selection of suitable electronic lamps, and can provide useful information to lighting equipment manufacturers for the development of lighting equipment that are suitable for electronic light sources for marine use. View full abstract»

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  • Design and implementation of a prototype underwater turbine generator system for renewable micro hydro power energy

    Page(s): 1 - 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (965 KB) |  | HTML iconHTML  

    This paper presents the results of design, installation and field measurement of a prototype underwater-turbine-generator-based micro hydro power (MHP) generation system. The studied MHP system employs the flowing water energy of the agricultural irrigation of one of the irrigation ditches of Yunlin Farmland Irrigation Association, Taiwan. Fundamentally, the irrigation ditches are used to distribute irrigation water to different farmlands. Design of a MHP has to meet practical conditions of the selected ditch such as depth, width, water flow rate, days of water flowing, etc. The designed MHP unit consists of a prototype underwater turbine, a gearbox, a three-phase self-excited induction generator with a switchable excitation capacitor bank, a three-phase diode bridge rectifier, a DC-to-DC buck converter, and a DC-to-AC inverter. An embedded-system-based monitoring and control system of the MHP unit is also properly designed to measure the electrical data of the MHP system. According to the field measurement results, the designed prototype underwater-turbine-generator-based MHP system can stably offer adequate electric power to the connected loads. View full abstract»

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  • Investigation of grid-connected photovoltaic generation system applied for Urban Rail Transit energy-savings

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (361 KB) |  | HTML iconHTML  

    In the paper, the feasibility and application modes of Photovoltaic (PV) generation system were studied in Urban Rail Transit (URT). Firstly, the paper estimates the capacity of PV cells installation, and gets the results that PV generation system applied in the URT energy-savings is feasible by studying a typical elevated line of Shanghai URT. And then, in view of the particularity of URT power system and its loads, AC grid-connected mode and DC grid-connected mode are presented, and the grid-connected topology and energy management strategy were developed respectively. The results of simulation and theoretical analysis show that the AC grid-connected mode is simple and its control strategy is mature, but it hasn't energy-savings amplification effect, DC grid-connected mode has energy-savings amplification effect, and can maximize the benefits of PV generation system through the optimization of control strategy. Finally, the key issues in the implementation of DC grid-connected mode were discussed. View full abstract»

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  • A novel power system defense plan to cope with 30% wind power penetration in the isolated Penghu system

    Page(s): 1 - 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (299 KB) |  | HTML iconHTML  

    In the plentiful wind resource on the Penghu Island, the capacity factor of the wind park is up to 47%. It is expected that more wind generating units will be integrated into this power system in the near future. However, many blackouts occurred at Penghu Island in the past and the present power protection scheme has not taken the influence of the wind generating units into consideration; therefore, it is necessary to revise the defense plan for Penghu's power system. In this study, different generation/load patterns in different seasons are considered, followed with analyses on system steady-state and transient responses in some specific buses and important feeders. The accurate modeling on wind turbines and relay settings are performed by using the power system simulation program PSS/E. The original power defense scheme by only using under-frequency load shedding is examined, and a new protection scheme is proposed based on numerous contingency simulations, including islanding operation protection for some specific cases. It is expected that the reliability improvement of the Penghu system can be achieved by using the new defense scheme. View full abstract»

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