Shanghai Turbine Works is the firstturbine manufacturer in China, starting fromthe production of first 6 MW mediumpressure steam turbine in 1953. It hasdeveloped 12 MW to 300 MW steam turbinesof various capacities of ...Shanghai Turbine Works is the firstturbine manufacturer in China, starting fromthe production of first 6 MW mediumpressure steam turbine in 1953. It hasdeveloped 12 MW to 300 MW steam turbinesof various capacities of condensing,intermediate reheat or cogeneration types. Upto 1995, the production of 300 MWsubcritical pressure intermediate reheat steamturbine has been accumulated to 60 sets. The600 MW class steam turbine is currentlyunder manufacture. Shanghai Turbine Worksis the only manufacturer in China to producelarge capacity nuclear turbine. The first set of310 MW nuclear turbine produced inDecember 1991 has been operating stably inQinshan Nuclear Power Plant, China. Overthe past 40 years, Shanghai Turbine Workshas produced 995 sets of power plant turbineswith 45.91 GW total capacity, which occupiesabout 30 percent of total installed fossil unitcapacity in China. Fig. 1 is the unit capacityincrement of Shanghai Turbine Works over the years.China is a huge market for electric powerdevelopment. Up展开更多
This paper proposes about a powerful control mechanism of UPQC (Unified Power Quality Conditioner) work on voltage source inverter which can effectively compensate source current harmonics and also mitigate all voltag...This paper proposes about a powerful control mechanism of UPQC (Unified Power Quality Conditioner) work on voltage source inverter which can effectively compensate source current harmonics and also mitigate all voltage collapse such as dip, swell, voltage unbalances and harmonics. The consolidation of series and parallel active power filters sharing mutual DC bus capacitor forms UPQC. PI (Proportional Integral) controller is mainly used in order to maintain continual DC voltage along with the hysteresis current controller. The parallel and series power filters were designed using 3-phase voltage source inverter. The reference signals for shunt and series active power filters were obtained by Synchronous Reference Frame (SRF) theory and Power Reactive (PQ) theory respectively. By using these theories, reference signals were obtained which was fed to the controllers for generating switching pulses for parallel and series active filters. The UPQC dynamic performance is obtained through testing terms like the compensation of voltage, current harmonics and all voltage distortion associated with 3-phase 3-wire power system which is simulated using MATLAB-Simulink software.展开更多
To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revit...To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revitalization of the country.For this reason,universities in China should give full attention to their role as the main propeller of science and technology.“Streamlining administration,delegating powers,improving regulation,and strengthening services”is a policy issued by the Chinese government for the management of science and technology funds in colleges and universities.Based on the policy of“streamlining administration,delegating powers,improving regulation,and strengthening services,”colleges and universities must optimize the management of science and technology funds for their efficient use.In this paper,we analyzed the importance of the policy and put forward an effective management strategy,aiming to improve the management of science and technology funds in colleges and universities.展开更多
The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived usi...The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived using the optimally weighted combination theory and the minimum sum of logarithmic squared errors as the objective function.Two typical anchor bolt pull-out engineering cases were selected to compare the performance of the proposed model with those of existing ones.Results showed that the optimal combination model was suitable not only for the slow P-s curve but also for the steep P-s curve.Its accuracy and stable reliability,as well as its prediction capability classification,were better than those of the other prediction models.Therefore,the optimal combination model is an effective processing method for predicting the maximum pull-out load of anchor bolts according to measured data.展开更多
This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its ...This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its performance and power quality(PQ).First,the latest metaheuristic artificial rabbits optimization(ARO)is used to locate and size solar photovoltaic(PV),wind turbine(WT)and D-STATCOM units.In the second stage,ratings of single-tuned PPFs and D-STATCOMs at the RESs are determined,considering non-linear loads in the network.The multi-objective function reduces power loss,improves the voltage stability index(VSI)and limits total harmonic distortion.Simulations using the IEEE 33-bus EDN compared the ARO results with those of previous studies.In the first scenario,ideally integrated D-STATCOMs,PVs and WTs reduced losses by 34.79%,64.74%and 94.15%,respectively.VSI increases from 0.6965 to 0.7749,0.8804 and 0.967.The optimal WT integration of the first scenario outperformed the PVs and D-STATCOMs.The second step optimizes the WTs and PQ devices for non-linear loads.WTs and D-STATCOMs reduce the maximum total harmonic distortion of the voltage waveform by 5.21%with non-linear loads to 3.23%,while WTs and PPFs reduce it to 4.39%.These scenarios demonstrate how WTs and D-STATCOMs can improve network performance and PQ.The computational efficiency of ARO is compared to that of the pathfinder algorithm,future search algorithm,butterfly optimization algorithm and coyote optimization algorithm.ARO speeds up convergence and improves solution quality and comprehension.展开更多
With the increasing penetration of renewable power in the grid,renewable generators are expected to play more important roles rather than merely working as active power sources.Considering the high controllability and...With the increasing penetration of renewable power in the grid,renewable generators are expected to play more important roles rather than merely working as active power sources.Considering the high controllability and considerable idle capacity of the inverter-based renewable generators,various auxiliary functions for them have been studied to benefit the grid.Among these auxiliary functions,the grid power quality improvement is very promising.This paper presents a review of the emerging control strategies for inverter-based renewable generators to improve grid power quality.The related papers are classified with different power quality issues and technical routes,and a comprehensive comparison is presented.The future trends of this research area are also discussed.展开更多
We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole....We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole. This imaging technique offers an increased contrast and a high scattered light rejection. It is demonstrated that the contrast close to the Sparrow resolution limit is enhanced and the sectioning power are increased with respect to the linear confocal detection mode. An experimental implementation is presented and compared with the conventional linear confocal mode.展开更多
Retraction： LIU Shuanggen, NI Haiying, HU Yupu, LIAO Yunyan. An Improved Simple Power Attack against Camellia＇s Key Schedule. Wuhan University Journal of Natural Sciences, 2008, 13（5）： 591-594. DOI： 10.1007/s 11...Retraction： LIU Shuanggen, NI Haiying, HU Yupu, LIAO Yunyan. An Improved Simple Power Attack against Camellia＇s Key Schedule. Wuhan University Journal of Natural Sciences, 2008, 13（5）： 591-594. DOI： 10.1007/s 11859-008-0516-3展开更多
文摘Shanghai Turbine Works is the firstturbine manufacturer in China, starting fromthe production of first 6 MW mediumpressure steam turbine in 1953. It hasdeveloped 12 MW to 300 MW steam turbinesof various capacities of condensing,intermediate reheat or cogeneration types. Upto 1995, the production of 300 MWsubcritical pressure intermediate reheat steamturbine has been accumulated to 60 sets. The600 MW class steam turbine is currentlyunder manufacture. Shanghai Turbine Worksis the only manufacturer in China to producelarge capacity nuclear turbine. The first set of310 MW nuclear turbine produced inDecember 1991 has been operating stably inQinshan Nuclear Power Plant, China. Overthe past 40 years, Shanghai Turbine Workshas produced 995 sets of power plant turbineswith 45.91 GW total capacity, which occupiesabout 30 percent of total installed fossil unitcapacity in China. Fig. 1 is the unit capacityincrement of Shanghai Turbine Works over the years.China is a huge market for electric powerdevelopment. Up
文摘This paper proposes about a powerful control mechanism of UPQC (Unified Power Quality Conditioner) work on voltage source inverter which can effectively compensate source current harmonics and also mitigate all voltage collapse such as dip, swell, voltage unbalances and harmonics. The consolidation of series and parallel active power filters sharing mutual DC bus capacitor forms UPQC. PI (Proportional Integral) controller is mainly used in order to maintain continual DC voltage along with the hysteresis current controller. The parallel and series power filters were designed using 3-phase voltage source inverter. The reference signals for shunt and series active power filters were obtained by Synchronous Reference Frame (SRF) theory and Power Reactive (PQ) theory respectively. By using these theories, reference signals were obtained which was fed to the controllers for generating switching pulses for parallel and series active filters. The UPQC dynamic performance is obtained through testing terms like the compensation of voltage, current harmonics and all voltage distortion associated with 3-phase 3-wire power system which is simulated using MATLAB-Simulink software.
文摘To advance the field of science and technology,we need to revitalize the development of science and technology through innovation.The development of science and technology has many beneficial implications on the revitalization of the country.For this reason,universities in China should give full attention to their role as the main propeller of science and technology.“Streamlining administration,delegating powers,improving regulation,and strengthening services”is a policy issued by the Chinese government for the management of science and technology funds in colleges and universities.Based on the policy of“streamlining administration,delegating powers,improving regulation,and strengthening services,”colleges and universities must optimize the management of science and technology funds for their efficient use.In this paper,we analyzed the importance of the policy and put forward an effective management strategy,aiming to improve the management of science and technology funds in colleges and universities.
基金The National Natural Science Foundation of China(No.51778485).
文摘The mixed model of improved exponential and power function and unequal interval gray GM(1,1)model have poor accuracy in predicting the maximum pull-out load of anchor bolts.An optimal combination model was derived using the optimally weighted combination theory and the minimum sum of logarithmic squared errors as the objective function.Two typical anchor bolt pull-out engineering cases were selected to compare the performance of the proposed model with those of existing ones.Results showed that the optimal combination model was suitable not only for the slow P-s curve but also for the steep P-s curve.Its accuracy and stable reliability,as well as its prediction capability classification,were better than those of the other prediction models.Therefore,the optimal combination model is an effective processing method for predicting the maximum pull-out load of anchor bolts according to measured data.
文摘This study suggests an optimal renewable energy source(RES)allocation and distribution-static synchronous compensator(D-STATCOM)and passive power filters(PPFs)for an electrical distribution network(EDN)to improve its performance and power quality(PQ).First,the latest metaheuristic artificial rabbits optimization(ARO)is used to locate and size solar photovoltaic(PV),wind turbine(WT)and D-STATCOM units.In the second stage,ratings of single-tuned PPFs and D-STATCOMs at the RESs are determined,considering non-linear loads in the network.The multi-objective function reduces power loss,improves the voltage stability index(VSI)and limits total harmonic distortion.Simulations using the IEEE 33-bus EDN compared the ARO results with those of previous studies.In the first scenario,ideally integrated D-STATCOMs,PVs and WTs reduced losses by 34.79%,64.74%and 94.15%,respectively.VSI increases from 0.6965 to 0.7749,0.8804 and 0.967.The optimal WT integration of the first scenario outperformed the PVs and D-STATCOMs.The second step optimizes the WTs and PQ devices for non-linear loads.WTs and D-STATCOMs reduce the maximum total harmonic distortion of the voltage waveform by 5.21%with non-linear loads to 3.23%,while WTs and PPFs reduce it to 4.39%.These scenarios demonstrate how WTs and D-STATCOMs can improve network performance and PQ.The computational efficiency of ARO is compared to that of the pathfinder algorithm,future search algorithm,butterfly optimization algorithm and coyote optimization algorithm.ARO speeds up convergence and improves solution quality and comprehension.
文摘With the increasing penetration of renewable power in the grid,renewable generators are expected to play more important roles rather than merely working as active power sources.Considering the high controllability and considerable idle capacity of the inverter-based renewable generators,various auxiliary functions for them have been studied to benefit the grid.Among these auxiliary functions,the grid power quality improvement is very promising.This paper presents a review of the emerging control strategies for inverter-based renewable generators to improve grid power quality.The related papers are classified with different power quality issues and technical routes,and a comprehensive comparison is presented.The future trends of this research area are also discussed.
基金The Si0x nanocrystals and clusters were deposited by D. Scuderi, 0. Albert, A. Dos Santos and J. Etchepare at the L0A. We thank Bertrand Reynier, Unité de Mécanique, ENSTA, France, for sample characterization by electron microscopy.
文摘We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole. This imaging technique offers an increased contrast and a high scattered light rejection. It is demonstrated that the contrast close to the Sparrow resolution limit is enhanced and the sectioning power are increased with respect to the linear confocal detection mode. An experimental implementation is presented and compared with the conventional linear confocal mode.
文摘Retraction： LIU Shuanggen, NI Haiying, HU Yupu, LIAO Yunyan. An Improved Simple Power Attack against Camellia＇s Key Schedule. Wuhan University Journal of Natural Sciences, 2008, 13（5）： 591-594. DOI： 10.1007/s 11859-008-0516-3
