To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation managemen...To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage展开更多
Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference ...Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.展开更多
A power saving frequency difference controlling method was introduced by the double inverter and motor experiment system.The characters of the system under differ- ent loads were investigated.The theoretical analysis ...A power saving frequency difference controlling method was introduced by the double inverter and motor experiment system.The characters of the system under differ- ent loads were investigated.The theoretical analysis and experiment results show the frequency difference method is a ideal power saving speed regulation method for the dou- ble inverter and motor system.The experiment system is simply structured,convenient to operate and provides a new way of character testing for frequency conversion speed regulation.展开更多
This paper presented a scheme of relayed cellular mobile telecommunication network,which only employs fixed digital relays and not more than two-hop relay routes.Power saving potential of the network is deeply studied...This paper presented a scheme of relayed cellular mobile telecommunication network,which only employs fixed digital relays and not more than two-hop relay routes.Power saving potential of the network is deeply studied under the assumption of not occupying additional frequency bands(i.e.relays share the same frequency bands as used by the base stations).Theoretical analysis and simulation results have both shown that,with the same radio coverage requirement,the necessary effective transmission powers in such a relayed network have greatly decreased compared to conventional cellular network.展开更多
In this paper, a high power factor LED driver with hot swap, smart output voltage regulation and dimming control is proposed. The dimming control is used to change LED brightness. During converter is working, the hot ...In this paper, a high power factor LED driver with hot swap, smart output voltage regulation and dimming control is proposed. The dimming control is used to change LED brightness. During converter is working, the hot swap function supply users to remove and insert LED module. The smart output voltage can regulate quickly and rightly output voltage in different number of LED series connection. The system consists two stages, one is 50 W flyback converter which is used as power factor corrector, it is input source is 110-220 V, PF （power factor） is about 0,994. The other is Boost DC/DC converter, it can offer 35-60 V of output voltage. Finally, a prototype has been built and tested. The simulation and experimental results are shown to verify the feasibility of the proposed method.展开更多
This paper presents a single-phase Z-source inverter as a power conditioning system for a single phase utility connected system. Z-source inverter is a single-stage topology that has buck-boost feature, which is possi...This paper presents a single-phase Z-source inverter as a power conditioning system for a single phase utility connected system. Z-source inverter is a single-stage topology that has buck-boost feature, which is possible because of additional shoot through state introduced in zero state of the conventional inverter pulse width modulation and provides desired output AC voltage. Small distributed generation （DG） system with alternate energy sources requires power conditioning units with low cost, high efficiency and tolerance to wide range of input voltage variation and has to perform various functions such as dc-ac conversion, system control and achieve power quality norms. To meet some of these requirements a two-loop control strategy for ac side control with grid current feedback with PI control and inner filter capacitor current feedback with proportional control and on dc side PID control for Z-source capacitor voltage regulation are employed, which gives good transient response also suppress load and source disturbances effectively. Theoretical analysis of proposed scheme is established and then simulation results are presented to validate proposed control strategy.展开更多
文摘To solve the coverage and quality problems caused by cell outage in LTE networks, this paper proposes a distributed self-organizing networks management architecture and a distributed cell outage compensation management mechanism. After detecting and analyzing the outage, a cell outage compensation algorithm based on reference signal power adjustment is proposed. The simulation results show that the proposed mechanism can mitigate the performance degradation significantly. Compared with other algorithms, the proposed scheme is more effective in compensating the coverage gap induced by cell outage
基金Supported by Liaoning Educational Foundation(202183386)
文摘Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.
文摘A power saving frequency difference controlling method was introduced by the double inverter and motor experiment system.The characters of the system under differ- ent loads were investigated.The theoretical analysis and experiment results show the frequency difference method is a ideal power saving speed regulation method for the dou- ble inverter and motor system.The experiment system is simply structured,convenient to operate and provides a new way of character testing for frequency conversion speed regulation.
基金National Science Fund for Creative ResearchGroups(No.60521002)Chinese NationalKey Technology R&D Program(No.2005BA908B02)Science Foundation ofShanghai Municipal Commission of Scienceand Technology,Chinese(No.05dz05802)
文摘This paper presented a scheme of relayed cellular mobile telecommunication network,which only employs fixed digital relays and not more than two-hop relay routes.Power saving potential of the network is deeply studied under the assumption of not occupying additional frequency bands(i.e.relays share the same frequency bands as used by the base stations).Theoretical analysis and simulation results have both shown that,with the same radio coverage requirement,the necessary effective transmission powers in such a relayed network have greatly decreased compared to conventional cellular network.
文摘In this paper, a high power factor LED driver with hot swap, smart output voltage regulation and dimming control is proposed. The dimming control is used to change LED brightness. During converter is working, the hot swap function supply users to remove and insert LED module. The smart output voltage can regulate quickly and rightly output voltage in different number of LED series connection. The system consists two stages, one is 50 W flyback converter which is used as power factor corrector, it is input source is 110-220 V, PF （power factor） is about 0,994. The other is Boost DC/DC converter, it can offer 35-60 V of output voltage. Finally, a prototype has been built and tested. The simulation and experimental results are shown to verify the feasibility of the proposed method.
文摘This paper presents a single-phase Z-source inverter as a power conditioning system for a single phase utility connected system. Z-source inverter is a single-stage topology that has buck-boost feature, which is possible because of additional shoot through state introduced in zero state of the conventional inverter pulse width modulation and provides desired output AC voltage. Small distributed generation （DG） system with alternate energy sources requires power conditioning units with low cost, high efficiency and tolerance to wide range of input voltage variation and has to perform various functions such as dc-ac conversion, system control and achieve power quality norms. To meet some of these requirements a two-loop control strategy for ac side control with grid current feedback with PI control and inner filter capacitor current feedback with proportional control and on dc side PID control for Z-source capacitor voltage regulation are employed, which gives good transient response also suppress load and source disturbances effectively. Theoretical analysis of proposed scheme is established and then simulation results are presented to validate proposed control strategy.
