To make full use of expanded maneuverability and increased range,adaptive constrained on-board guidance technology is the key capability for a glide vehicle with a double-pulse rocket engine,especially under the requi...To make full use of expanded maneuverability and increased range,adaptive constrained on-board guidance technology is the key capability for a glide vehicle with a double-pulse rocket engine,especially under the requirements of desired target changing and on-line reconfigurable control and guidance.Based on the rapid footprint analysis,whether the new target is within the current footprint area is firstly judged.If not,the rocket engine ignites by the logic obtained from the analysis of optimal flight range by the method of hp-adaptive Gauss pseudospectral method(hp-GPM).Then,an on-board trajectory generation method based on powered quasi-equilibrium glide condition(QEGC)and linear quadratic regulator(LQR)method is used to guide the vehicle to the new target.The effectiveness of the guidance method consisted of powered on-board trajectory generation,LQR trajectory tracking,footprint calculation,and ignition time determination is indicated by some simulation examples.展开更多
A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a...A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a study on optimal energy saving in DC-electrified railway with on-board energy storage system(OBESS) by using peak demand cutting strategy under different trip time controls.The proposed strategy uses OBESS to store recovered braking energy and find an appropriated time to deliver the stored energy back to the power network in such a way that peak power of every substations is reduced.Bangkok Mass Transit System(BTS)-Silom Line in Thailand is used to test and verify the proposed strategy.The results show that substation peak power is reduced by63.49% and net energy consumption is reduced by 15.56%using coasting and deceleration trip time control.展开更多
This paper discusses a high efficient parallel circuit simulator for iterative power grid optimization. The simulator is implemented by FPGA. We focus particularly on the following points: 1) Selection of the analysis...This paper discusses a high efficient parallel circuit simulator for iterative power grid optimization. The simulator is implemented by FPGA. We focus particularly on the following points: 1) Selection of the analysis method for power grid optimization, the proposed simulator introduces hardware-oriented fixed point arithmetic instead of floating point arithmetic. It accomplishes the high accuracy by selecting appropriate time step of the simulation;2) The simulator achieves high speed simulation by developing dedicated hardware and adopting parallel processing. Experiments prove that the proposed simulator using 80 MHz FPGA and eight parallel processing achieves 35 times faster simulation than software processing with 2.8 GHz CPU while maintaining almost same accuracy in comparison with SPICE simulation.展开更多
This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric po...This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric power communication network. It presents a new Communication System-IDS-2000 integrated digital communication system. The paper introduces the characteristics and application of IDS-2000 system in the local electric power communication network.展开更多
Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical cont...Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical control organization can be divided into 5levels,i.e.NCC,6 RCCs,25 PCCs,250 DCCs and more than 2000CCCs. 3.All control centers will be equipped with SCADA and EMSin the near future.4.China power system has a large,dedicated communicationnetwork of its own.展开更多
地铁专用通信电源系统是地铁通信系统的一个重要子系统,不间断电源(Uninterruptible Power Supply,UPS)是地铁通信电源系统的重要组成设备。阐述地铁通信电源UPS各个部件构成,包括输入单元、整流器、逆变器、蓄电池组以及静态开关等,介...地铁专用通信电源系统是地铁通信系统的一个重要子系统,不间断电源(Uninterruptible Power Supply,UPS)是地铁通信电源系统的重要组成设备。阐述地铁通信电源UPS各个部件构成,包括输入单元、整流器、逆变器、蓄电池组以及静态开关等,介绍各个部件工作原理和地铁通信UPS采用的在线工作方式,并分析单机4种供电工作模式和并机5种供电工作模式的原理。最后,列举实际维护过程中发生的4件UPS故障,通过原因分析及处理过程描述,帮助提高UPS维护的实践能力。展开更多
基金supported by the National Natural Science Foundation of China(No.61403100)Fundamental Research Funds for the Central Universities(HIT.NSRIF.2015037)
文摘To make full use of expanded maneuverability and increased range,adaptive constrained on-board guidance technology is the key capability for a glide vehicle with a double-pulse rocket engine,especially under the requirements of desired target changing and on-line reconfigurable control and guidance.Based on the rapid footprint analysis,whether the new target is within the current footprint area is firstly judged.If not,the rocket engine ignites by the logic obtained from the analysis of optimal flight range by the method of hp-adaptive Gauss pseudospectral method(hp-GPM).Then,an on-board trajectory generation method based on powered quasi-equilibrium glide condition(QEGC)and linear quadratic regulator(LQR)method is used to guide the vehicle to the new target.The effectiveness of the guidance method consisted of powered on-board trajectory generation,LQR trajectory tracking,footprint calculation,and ignition time determination is indicated by some simulation examples.
文摘A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a study on optimal energy saving in DC-electrified railway with on-board energy storage system(OBESS) by using peak demand cutting strategy under different trip time controls.The proposed strategy uses OBESS to store recovered braking energy and find an appropriated time to deliver the stored energy back to the power network in such a way that peak power of every substations is reduced.Bangkok Mass Transit System(BTS)-Silom Line in Thailand is used to test and verify the proposed strategy.The results show that substation peak power is reduced by63.49% and net energy consumption is reduced by 15.56%using coasting and deceleration trip time control.
文摘This paper discusses a high efficient parallel circuit simulator for iterative power grid optimization. The simulator is implemented by FPGA. We focus particularly on the following points: 1) Selection of the analysis method for power grid optimization, the proposed simulator introduces hardware-oriented fixed point arithmetic instead of floating point arithmetic. It accomplishes the high accuracy by selecting appropriate time step of the simulation;2) The simulator achieves high speed simulation by developing dedicated hardware and adopting parallel processing. Experiments prove that the proposed simulator using 80 MHz FPGA and eight parallel processing achieves 35 times faster simulation than software processing with 2.8 GHz CPU while maintaining almost same accuracy in comparison with SPICE simulation.
文摘This paper describes current situation and special requirements of local electric power communication network in China. The paper discusses the disadvantages of SDH and fiber loop carrier system applied to electric power communication network. It presents a new Communication System-IDS-2000 integrated digital communication system. The paper introduces the characteristics and application of IDS-2000 system in the local electric power communication network.
文摘Summary1.There are 12 power systems including 5 regional powersystems with over 1000MW of capacity each.In 1989 Central andEast China power systems were interconnected by a±500kV HVDC Line.2.The hierarchical control organization can be divided into 5levels,i.e.NCC,6 RCCs,25 PCCs,250 DCCs and more than 2000CCCs. 3.All control centers will be equipped with SCADA and EMSin the near future.4.China power system has a large,dedicated communicationnetwork of its own.
文摘地铁专用通信电源系统是地铁通信系统的一个重要子系统,不间断电源(Uninterruptible Power Supply,UPS)是地铁通信电源系统的重要组成设备。阐述地铁通信电源UPS各个部件构成,包括输入单元、整流器、逆变器、蓄电池组以及静态开关等,介绍各个部件工作原理和地铁通信UPS采用的在线工作方式,并分析单机4种供电工作模式和并机5种供电工作模式的原理。最后,列举实际维护过程中发生的4件UPS故障,通过原因分析及处理过程描述,帮助提高UPS维护的实践能力。
