With the rapid development of the construction of high-speed railway in china, higher levels of power quality and reliability of traction power supply systems are required.The combination of bilateral power supply tec...With the rapid development of the construction of high-speed railway in china, higher levels of power quality and reliability of traction power supply systems are required.The combination of bilateral power supply technology with AT traction power supply technology can better meet the needs of development of high-speed railways, which will require new protection approaches to be proposed. Thus, corresponding protection schemes will be of great significance for the application and promotion of bilateral power supply technology.展开更多
Virtual supply chain based on cybermediary (VSC-CM) is an innovative VSC pattern meeting informationization development requirements in the manufacturing industry. Methods and features of customer-demand-oriented opti...Virtual supply chain based on cybermediary (VSC-CM) is an innovative VSC pattern meeting informationization development requirements in the manufacturing industry. Methods and features of customer-demand-oriented optimum VSC design adopted by CM are discussed. A customer demand goal system applying to VSC-CM design and quantifying methods of these goals are accordingly given. Then a three-stage optimum VSC design scheme based on dynamic goals is designed, which considers both the holistic optimization of VSC and individuation demands of member enterprises. To implement the scheme, an optimum algorithm synthesizing fuzzy c-means clustering algorithm and topsis comprehensive evaluation algorithm is presented. Feasibility and rapidity of this scheme is proved through a case analysis finally.展开更多
Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bila...Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bilateral system can be put applied in China is discussed. Compared with unilateral power supply system, bilateral system has better reliability and better capability of supply power system, which gives bilateral system more advantages over unilateral system on both engineering investment and operating efficiency. In this paper, voltage losses under the two different systems are calculated and also compared, the advantages of bilateral system is explored and then conclusion is drawn by referring to the practical data of passenger transport lines.展开更多
The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from ...The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions.展开更多
Loads in large scale industrial enterprises are always various and complex, causing insecure power quality. Meanwhile, some sensitive loads or precise instruments demand for high power quality. When voltage flicker or...Loads in large scale industrial enterprises are always various and complex, causing insecure power quality. Meanwhile, some sensitive loads or precise instruments demand for high power quality. When voltage flicker or harmonics occurs, dynamic voltage restorer (DVR) can be used to stabilize the load-side voltage, which is a good manner of improving power quality. The paper explains the load demand in large scale industrial enterprises, analyzes several common voltage compensation scheme of DVR, and comes up with another voltage compensation scheme of DVR applied for double power supply with double load. A Simulink model according to the new scheme is also built in MATLAB/Simulink to test its performance. Simulation results show that the proposed scheme can guarantee the load-side voltage stability, which is an effective scheme for managing power quality.展开更多
文摘With the rapid development of the construction of high-speed railway in china, higher levels of power quality and reliability of traction power supply systems are required.The combination of bilateral power supply technology with AT traction power supply technology can better meet the needs of development of high-speed railways, which will require new protection approaches to be proposed. Thus, corresponding protection schemes will be of great significance for the application and promotion of bilateral power supply technology.
基金Key Scientific and Technological Project of Hubei Province,China(No.2006AA108A03)International Cooperation Program of Technology Bureau of Hubei Province,China(No.2007CA008)
文摘Virtual supply chain based on cybermediary (VSC-CM) is an innovative VSC pattern meeting informationization development requirements in the manufacturing industry. Methods and features of customer-demand-oriented optimum VSC design adopted by CM are discussed. A customer demand goal system applying to VSC-CM design and quantifying methods of these goals are accordingly given. Then a three-stage optimum VSC design scheme based on dynamic goals is designed, which considers both the holistic optimization of VSC and individuation demands of member enterprises. To implement the scheme, an optimum algorithm synthesizing fuzzy c-means clustering algorithm and topsis comprehensive evaluation algorithm is presented. Feasibility and rapidity of this scheme is proved through a case analysis finally.
文摘Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bilateral system can be put applied in China is discussed. Compared with unilateral power supply system, bilateral system has better reliability and better capability of supply power system, which gives bilateral system more advantages over unilateral system on both engineering investment and operating efficiency. In this paper, voltage losses under the two different systems are calculated and also compared, the advantages of bilateral system is explored and then conclusion is drawn by referring to the practical data of passenger transport lines.
文摘The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions.
文摘Loads in large scale industrial enterprises are always various and complex, causing insecure power quality. Meanwhile, some sensitive loads or precise instruments demand for high power quality. When voltage flicker or harmonics occurs, dynamic voltage restorer (DVR) can be used to stabilize the load-side voltage, which is a good manner of improving power quality. The paper explains the load demand in large scale industrial enterprises, analyzes several common voltage compensation scheme of DVR, and comes up with another voltage compensation scheme of DVR applied for double power supply with double load. A Simulink model according to the new scheme is also built in MATLAB/Simulink to test its performance. Simulation results show that the proposed scheme can guarantee the load-side voltage stability, which is an effective scheme for managing power quality.
