The Experts below are selected from a list of 18894 Experts worldwide ranked by ideXlab platform
Timothy M. Weis - One of the best experts on this subject based on the ideXlab platform.
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The utility of energy storage to improve the economics of wind–diesel power plants in Canada
Renewable Energy, 2008Co-Authors: Timothy M. Weis, Adrian IlincaAbstract:Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is geneRated when the wind turbines operate at Rated Capacity.
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the utility of energy storage to improve the economics of wind diesel power plants in canada
Renewable Energy, 2008Co-Authors: Timothy M. Weis, Adrian IlincaAbstract:Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is geneRated when the wind turbines operate at Rated Capacity.
Adrian Ilinca - One of the best experts on this subject based on the ideXlab platform.
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The utility of energy storage to improve the economics of wind–diesel power plants in Canada
Renewable Energy, 2008Co-Authors: Timothy M. Weis, Adrian IlincaAbstract:Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is geneRated when the wind turbines operate at Rated Capacity.
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the utility of energy storage to improve the economics of wind diesel power plants in canada
Renewable Energy, 2008Co-Authors: Timothy M. Weis, Adrian IlincaAbstract:Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is geneRated when the wind turbines operate at Rated Capacity.
Kazunaga Ueda - One of the best experts on this subject based on the ideXlab platform.
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Performance of a stiffened 50 N force comparator referring to a tuning-fork force transducer
Measurement, 2018Co-Authors: Toshiyuki Hayashi, Kazunaga UedaAbstract:Abstract A force comparator was developed by adopting a highly stable tuning-fork-type force transducer with 50 N Rated Capacity as the reference. Its structure was stiffened to reduce the effects of eccentric forces and moments caused by the screw of the force generation mechanism. Strain-gauge-type force transducers were evaluated using the comparator and were also calibRated using a dead-weight-type force standard machine to demonstrate the capability of the comparator. Deviations between the comparator and reference machine results were sufficiently smaller than the measurement uncertainties. At present, major uncertainty components that arose from the evaluated force transducer itself degraded the evaluation capability to a relative standard uncertainty of 1.2 × 10−4. If better force transducers become available in future, it should be possible to improve the relative standard uncertainty to 6.0 × 10−5.
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Calibration of reference torque wrenches using a 10 N m deadweight torque standard machine
Measurement, 2015Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:Abstract Within the torque traceability system in Japan, there are two processes, one for “pure torque” loading without any parasitic components, and the other for “torque wrench” loading with unavoidable transverse force and bending moment. The torque standard for reference torque wrenches (RTWs), which is a reference standard for first-grade accredited laboratories, has been disseminated in the range from 5 N m to 5 kN m using other torque standard machines at the National Metrology Institute of Japan (NMIJ). In this study, in order to expand the range of the torque standard for RTWs, we designed new holders allowing small-Rated-Capacity RTWs to be calibRated using the 10 N m deadweight torque standard machine (10-N m-DWTSM). We also studied the calibration method for small-Rated-Capacity RTWs according to the guidelines that have been adopted for medium and large RTWs. Experiments conducted using two kinds of small-Rated-Capacity RTWs showed that the 10-N m-DWTSM equipped with new holders can calibrate small-Rated-Capacity RTWs, and the calibration procedure ordinarily adopted for medium to large Capacity RTWs is also applicable to the calibration of small-Rated-Capacity RTWs. The newly designed holder with an aerostatic shaft resulted in a smaller relative standard uncertainty due to reproducibility with a change in mounting position compared with that obtained using the conventional holder with a solid shaft.
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DEVELOPMENT OF A NEW SMALL-Rated-Capacity REFERENCE TORQUE WRENCH
International Journal of Modern Physics: Conference Series, 2013Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:It is imperative that torque standard of small Rated Capacity is established and disseminated throughout Japanese industry. A 10 N·m dead weight torque standard machine (10-N·m-DWTSM) has been developed and evaluated at the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST). By 2012, the relative expanded uncertainty of torque realized by the 10-N·m-DWTSM was estimated to be 6.6 × 10−5, with the coverage factor k begin equal to 2, in a range from 0.1 N·m to 10 N·m for calibrations of the torque measuring devices (TMDs). Calibration service for small-Rated-Capacity TMDs was started to disseminate the torque standard throughout Japanese industry. Here, there are two routes in the torque traceability system in Japan. One is the route for TMDs and the other one is the route for reference torque wrenches (RTWs). The torque standard in the form of RTWs has been disseminated in the range from 5 N·m to 5 kN·m by using the TSMs owned by NMIJ. There remains a strong demand to expand the calibration range of RTWs. To expand the range, we should develop the new high-accuracy small-Rated-Capacity RTW and evaluate its calibration method. In this study, a high-accuracy RTW (TP-5N-1109), which had a Rated Capacity of 5 N·m, was newly developed and calibRated with the 10-N·m-DWTSM to evaluate its characteristics. The ordinary calibration procedures adopted at NMIJ was investigated whether it was applicable to the small-Rated-Capacity RTWs. As a result, the TP-5N-1109 showed good performance in the creep testing, and its characteristic curves were draw for all cases of the calibration procedures. The repeatability in the calibration results was good. We clarified the problem with the calibration conditions of the small-Rated-Capacity RTW to calibrate it by three cases.
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range expansion of the reference torque wrench calibration service to 5 kn m at nmij
Measurement, 2012Co-Authors: K. Ogushi, Atsuhiro Nishino, Koji Maeda, Kazunaga UedaAbstract:Abstract The reference torque wrench (RTW) calibration service within the range from 5 N m to 1 kN m has been provided to industry by the National Metrology Institute of Japan (NMIJ) in the National Institute of Advanced Industrial Science and Technology (AIST). Reflecting the strong demand from Japanese industry, the calibration range was extended to 5 kN m. First, a high-precision torque transducer in the form of a torque wrench with a Rated Capacity of 5 kN m was developed in order to establish a calibration method for such a large RTW. Second, the calibration method was investigated using a deadweight type torque standard machine with a Rated Capacity of 20 kN m as a reference standard. Aimed expanded calibration range is from 200 N m to 5 kN m. As a result of calibration experiment using three transducers having different Rated capacities, a relative expanded uncertainty of less than 7.0 × 10−5 could be obtained at a certain calibration point in the best case.
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evaluation of moment arm length and fulcrum sensitivity limit in a 10 n m dead weight torque standard machine
Measurement, 2010Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:Abstract Many torque tools, such as torque wrenches and torque screwdrivers, as well as torque measuring devices (TMDs) with a Rated Capacity of less than 5 N·m are being widely used in industry. Thus, a small-Rated-Capacity torque standard has to be established as soon as possible. A 10 N·m dead weight torque standard machine (10 N·m DWTSM) has been under development since 2006 at the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST). Characteristically, the main parts of the moment arm are made of low thermal-expansion alloy (Super INVAR), and an aerostatic bearing is employed as the fulcrum supporting the moment arm to minimize rotational friction. The moment arm was evaluated with regard to the coefficient of thermal expansion (CTE), the lengths measured by a 3D coordinate measurement machine (CMM), and temperature correction realized by measuring the moment arm temperature. The sensitivity limit of the fulcrum in the 10 N·m DWTSM was also estimated. As a result, the apparent overall CTE of the moment arm was 1.06 × 10−6 K−1, and the expanded uncertainty was 2.24 × 10−9 K−1 (k = 2). The results of the CMM measurement were a right-hand side length of 510.2773 mm and a left-hand side length of 510.2657 mm, with a relative expanded uncertainty of 4.0 × 10−5 (k = 2). The moment arm temperature increased by approximately 0.6 K during the ordinary calibration process. The corresponding change in the lengths of the moment arm was estimated to be approximately 0.3 μm, which is considered to be sufficiently small compared with the expanded uncertainty of the lengths of the moment arm. The fulcrum of the 10 N·m DWTSM was found to have sufficient sensitivity under three conditions: without the weight loading components, with the weight loading components, and with loaded weights. In particular, the fulcrum had sufficient sensitivity of at least 0.5 mg when weights of 100 g were loaded on both 5th stages in the weight loading components to generate a radial load equivalent to 1 N·m.
Xuan Wei - One of the best experts on this subject based on the ideXlab platform.
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A dispatch strategy for a unified power-flow controller to maximize voltage-stability-limited power transfer
IEEE Transactions on Power Delivery, 2005Co-Authors: Xuan Wei, B. Fardanesh, Joe H. Chow, A.-a. EdrisAbstract:For a system with a unified power-flow controller (UPFC), maximum power transfer capability is often achieved when the UPFC is opeRated at its Rated Capacity and conventional voltage and line-flow setpoint regulation is no longer possible. This paper uses injected voltage sources to directly model a UPFC and impose the rating limits in a Newton-Raphson load-flow algorithm. A dispatch strategy is proposed for a UPFC operating at Rated Capacity in which the power circulation between the shunt and series converters is used as the parameter to optimize the power transfer. Voltage-stability curves for two test systems are shown to illustrate the effectiveness of this proposed strategy.
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Voltage-sourced converter based facts controllers, modelling, dispatch, computation, and control
2004Co-Authors: Joe H. Chow, Xuan WeiAbstract:Flexible AC Transmission System (FACTS) Controllers offer potentials to directly control flows and voltages on an ac network. A newer generation of FACTS Controllers based on voltage-sourced converters (VSC) provides fast controllable shunt and series voltage injections into the ac network, with which further enhancement in controllability and power transfer capability can be achieved. In this research work, we tackle the problems of modeling, dispatching, and control of various VSC-based FACTS Controllers, including the Static Synchronous Compensator (STATCOM), Static Synchronous Series Compensator (SSSC), Unified Power Flow Controller (UPFC), Interline Power Flow Controller (IPFC), and Generalized Unified Power Flow Controller (GUPFC). We use the injected shunt and series voltage sources to model the VSC-based FACTS controllers. This offers a common modeling framework, based on which a Newton-Raphson loadflow solution and a network sensitivity analysis tool can be readily developed. The FACTS Controller sensitivities, similar to generator shift factors affecting network flows, provide a linear estimate of the effect of the FACTS control variables on the network variables, and are useful for the analysis and optimal dispatch of FACTS Controllers. Using the sensitivity analysis, methodologies for dispatch optimizations, including voltage dispatch, power dispatch, and maximizing power transfer, are presented. When FACTS Controllers operate at the Rated Capacity, advanced dispatch strategies are required because voltage and power setpoint enforcement of the FACTS Controllers are no longer possible. A dispatch strategy for the UPFC operating at Rated Capacity is presented, in which the circulating power between the coupled VSCs is used as the parameter to co-optimize the coupled shunt and series VSCs, while respecting the operational constraints. A similar strategy using the power circulation regulation is also proposed for the IPFC. Voltage stability curves are used to illustrate the effectiveness of the strategy to maximize voltage-stability limited power transfer. An automatic control system is proposed to implement the power circulation dispatch strategy in real-time for both normal operation and Rated Capacity conditions.
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A dispatch strategy for multiple unified power flow controllers to maximize voltage-stability limited power transfer
IEEE Power Engineering Society General Meeting 2005, 1Co-Authors: Xuan Wei, J.h. Cjow, A.-a. Edris, B. FardaneshAbstract:In this paper, the dispatch coordination of multiple unified power flow controllers (UPFC) operating in the power control mode and the Rated Capacity mode is investigated using a power circulation dispatch strategy. The strategy uses the circulation power between coupled shunt and series converters of a UPFC to optimize voltage-stability limited power transfer, thus reducing the complexity of power dispatch. The strategy is demonstRated for a test system with two UPFCs.
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A dispatch strategy for an interline power flow controller operating at Rated Capacity
IEEE PES Power Systems Conference and Exposition 2004., 1Co-Authors: Xuan Wei, B. Fardanesh, Joe H. Chow, A.-a. EdrisAbstract:The maximum dispatch benefit of an interline power flow controller (IPFC) often occurs when it operates at its Rated Capacity and line flow setpoint regulation is no longer possible. This paper uses injected voltage sources to directly model an IPFC and impose the rating limits in a Newton-Raphson load flow algorithm. A dispatch strategy is proposed for an IPFC operating at Rated Capacity, in which the power circulation between the two series converters is used as the parameter to optimize the voltage profile and power transfer. Voltage stability curves for two test systems are shown to illustrate the effectiveness of this proposed strategy.
K. Ogushi - One of the best experts on this subject based on the ideXlab platform.
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The testing evaluation of several digital torque wrenches by using a torque wrench tester
ACTA IMEKO, 2020Co-Authors: K. OgushiAbstract:Hand torque wrenches (HTWs) with electrical indicating devices (Type I, Class B defined in ISO 6789-1:2017; called “digital torque wrenches”) manufactured by several manufacturers were tested and evaluated. The digital torque wrench is the most accurate in all types of HTWs in general. The reference standard was a torque wrench tester (TWT) with a Rated Capacity of 50 N · m. This TWT has been calibRated by using a traceable reference torque wrench (RTW). Testing results are described with some characteristics.
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Calibration of reference torque wrenches using a 10 N m deadweight torque standard machine
Measurement, 2015Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:Abstract Within the torque traceability system in Japan, there are two processes, one for “pure torque” loading without any parasitic components, and the other for “torque wrench” loading with unavoidable transverse force and bending moment. The torque standard for reference torque wrenches (RTWs), which is a reference standard for first-grade accredited laboratories, has been disseminated in the range from 5 N m to 5 kN m using other torque standard machines at the National Metrology Institute of Japan (NMIJ). In this study, in order to expand the range of the torque standard for RTWs, we designed new holders allowing small-Rated-Capacity RTWs to be calibRated using the 10 N m deadweight torque standard machine (10-N m-DWTSM). We also studied the calibration method for small-Rated-Capacity RTWs according to the guidelines that have been adopted for medium and large RTWs. Experiments conducted using two kinds of small-Rated-Capacity RTWs showed that the 10-N m-DWTSM equipped with new holders can calibrate small-Rated-Capacity RTWs, and the calibration procedure ordinarily adopted for medium to large Capacity RTWs is also applicable to the calibration of small-Rated-Capacity RTWs. The newly designed holder with an aerostatic shaft resulted in a smaller relative standard uncertainty due to reproducibility with a change in mounting position compared with that obtained using the conventional holder with a solid shaft.
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DEVELOPMENT OF A NEW SMALL-Rated-Capacity REFERENCE TORQUE WRENCH
International Journal of Modern Physics: Conference Series, 2013Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:It is imperative that torque standard of small Rated Capacity is established and disseminated throughout Japanese industry. A 10 N·m dead weight torque standard machine (10-N·m-DWTSM) has been developed and evaluated at the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST). By 2012, the relative expanded uncertainty of torque realized by the 10-N·m-DWTSM was estimated to be 6.6 × 10−5, with the coverage factor k begin equal to 2, in a range from 0.1 N·m to 10 N·m for calibrations of the torque measuring devices (TMDs). Calibration service for small-Rated-Capacity TMDs was started to disseminate the torque standard throughout Japanese industry. Here, there are two routes in the torque traceability system in Japan. One is the route for TMDs and the other one is the route for reference torque wrenches (RTWs). The torque standard in the form of RTWs has been disseminated in the range from 5 N·m to 5 kN·m by using the TSMs owned by NMIJ. There remains a strong demand to expand the calibration range of RTWs. To expand the range, we should develop the new high-accuracy small-Rated-Capacity RTW and evaluate its calibration method. In this study, a high-accuracy RTW (TP-5N-1109), which had a Rated Capacity of 5 N·m, was newly developed and calibRated with the 10-N·m-DWTSM to evaluate its characteristics. The ordinary calibration procedures adopted at NMIJ was investigated whether it was applicable to the small-Rated-Capacity RTWs. As a result, the TP-5N-1109 showed good performance in the creep testing, and its characteristic curves were draw for all cases of the calibration procedures. The repeatability in the calibration results was good. We clarified the problem with the calibration conditions of the small-Rated-Capacity RTW to calibrate it by three cases.
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range expansion of the reference torque wrench calibration service to 5 kn m at nmij
Measurement, 2012Co-Authors: K. Ogushi, Atsuhiro Nishino, Koji Maeda, Kazunaga UedaAbstract:Abstract The reference torque wrench (RTW) calibration service within the range from 5 N m to 1 kN m has been provided to industry by the National Metrology Institute of Japan (NMIJ) in the National Institute of Advanced Industrial Science and Technology (AIST). Reflecting the strong demand from Japanese industry, the calibration range was extended to 5 kN m. First, a high-precision torque transducer in the form of a torque wrench with a Rated Capacity of 5 kN m was developed in order to establish a calibration method for such a large RTW. Second, the calibration method was investigated using a deadweight type torque standard machine with a Rated Capacity of 20 kN m as a reference standard. Aimed expanded calibration range is from 200 N m to 5 kN m. As a result of calibration experiment using three transducers having different Rated capacities, a relative expanded uncertainty of less than 7.0 × 10−5 could be obtained at a certain calibration point in the best case.
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evaluation of moment arm length and fulcrum sensitivity limit in a 10 n m dead weight torque standard machine
Measurement, 2010Co-Authors: Atsuhiro Nishino, K. Ogushi, Kazunaga UedaAbstract:Abstract Many torque tools, such as torque wrenches and torque screwdrivers, as well as torque measuring devices (TMDs) with a Rated Capacity of less than 5 N·m are being widely used in industry. Thus, a small-Rated-Capacity torque standard has to be established as soon as possible. A 10 N·m dead weight torque standard machine (10 N·m DWTSM) has been under development since 2006 at the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST). Characteristically, the main parts of the moment arm are made of low thermal-expansion alloy (Super INVAR), and an aerostatic bearing is employed as the fulcrum supporting the moment arm to minimize rotational friction. The moment arm was evaluated with regard to the coefficient of thermal expansion (CTE), the lengths measured by a 3D coordinate measurement machine (CMM), and temperature correction realized by measuring the moment arm temperature. The sensitivity limit of the fulcrum in the 10 N·m DWTSM was also estimated. As a result, the apparent overall CTE of the moment arm was 1.06 × 10−6 K−1, and the expanded uncertainty was 2.24 × 10−9 K−1 (k = 2). The results of the CMM measurement were a right-hand side length of 510.2773 mm and a left-hand side length of 510.2657 mm, with a relative expanded uncertainty of 4.0 × 10−5 (k = 2). The moment arm temperature increased by approximately 0.6 K during the ordinary calibration process. The corresponding change in the lengths of the moment arm was estimated to be approximately 0.3 μm, which is considered to be sufficiently small compared with the expanded uncertainty of the lengths of the moment arm. The fulcrum of the 10 N·m DWTSM was found to have sufficient sensitivity under three conditions: without the weight loading components, with the weight loading components, and with loaded weights. In particular, the fulcrum had sufficient sensitivity of at least 0.5 mg when weights of 100 g were loaded on both 5th stages in the weight loading components to generate a radial load equivalent to 1 N·m.
