Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for opti...Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for optimized utilization,a lot of research has been focusing on how to use the energy efficiently and gain sustainable benefits.The energy storage system is an alternative because it not only deals with regenerative braking energy but also smooths drastic fluctuation of load power profile and optimizes energy management.In this work,we propose a co-phase traction power supply system with super capacitor(CSS_SC)for the purpose of realizing the function of energy management and power quality management in electrified railways.Besides,the coordinated control strategy is presented to match four working modes,including traction,regenerative braking,peak shaving and valley filling.A corresponding simulation model is built in MATLAB/Simulink to verify the feasibility of the proposed system under dynamic working conditions.The results demonstrate that CSS_SC is flexible to deal with four different working conditions and can realize energy saving within the allowable voltage unbalance of 0.008%in simulation in contrast to 1.3%of the standard limit.With such a control strategy,the performance of super capacitor is controlled to comply with efficiency and safety constraints.Finally,a case study demonstrates the improvement in power fluctuation with the valley-to-peak ratio reduced by 20.3%and the daily load factor increased by 17.9%.展开更多
Tunneling-based static random-access memory(SRAM)devices have been developed to fulfill the demands of high density and low power,and the performance of SRAMs has also been greatly promoted.However,for a long time,the...Tunneling-based static random-access memory(SRAM)devices have been developed to fulfill the demands of high density and low power,and the performance of SRAMs has also been greatly promoted.However,for a long time,there has not been a silicon based tunneling device with both high peak valley current ratio(PVCR)and practicality,which remains a gap to be filled.Based on the existing work,the current manuscript proposed the concept of a new silicon-based tunneling device,i.e.,the silicon crosscoupled gated tunneling diode(Si XTD),which is quite simple in structure and almost completely compatible with mainstream technology.With technology computer aided design(TCAD)simulations,it has been validated that this type of device not only exhibits significant negative-differential-resistance(NDR)behavior with PVCRs up to 10^(6),but also possesses reasonable process margins.Moreover,SPICE simulation showed the great potential of such devices to achieve ultralow-power tunneling-based SRAMs with standby power down to 10^(−12)W.展开更多
文摘Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for optimized utilization,a lot of research has been focusing on how to use the energy efficiently and gain sustainable benefits.The energy storage system is an alternative because it not only deals with regenerative braking energy but also smooths drastic fluctuation of load power profile and optimizes energy management.In this work,we propose a co-phase traction power supply system with super capacitor(CSS_SC)for the purpose of realizing the function of energy management and power quality management in electrified railways.Besides,the coordinated control strategy is presented to match four working modes,including traction,regenerative braking,peak shaving and valley filling.A corresponding simulation model is built in MATLAB/Simulink to verify the feasibility of the proposed system under dynamic working conditions.The results demonstrate that CSS_SC is flexible to deal with four different working conditions and can realize energy saving within the allowable voltage unbalance of 0.008%in simulation in contrast to 1.3%of the standard limit.With such a control strategy,the performance of super capacitor is controlled to comply with efficiency and safety constraints.Finally,a case study demonstrates the improvement in power fluctuation with the valley-to-peak ratio reduced by 20.3%and the daily load factor increased by 17.9%.
基金supported by the National Key Research and Development Program of China under Grant No.2021YFB2800304.
文摘Tunneling-based static random-access memory(SRAM)devices have been developed to fulfill the demands of high density and low power,and the performance of SRAMs has also been greatly promoted.However,for a long time,there has not been a silicon based tunneling device with both high peak valley current ratio(PVCR)and practicality,which remains a gap to be filled.Based on the existing work,the current manuscript proposed the concept of a new silicon-based tunneling device,i.e.,the silicon crosscoupled gated tunneling diode(Si XTD),which is quite simple in structure and almost completely compatible with mainstream technology.With technology computer aided design(TCAD)simulations,it has been validated that this type of device not only exhibits significant negative-differential-resistance(NDR)behavior with PVCRs up to 10^(6),but also possesses reasonable process margins.Moreover,SPICE simulation showed the great potential of such devices to achieve ultralow-power tunneling-based SRAMs with standby power down to 10^(−12)W.
