对广西平班电厂机组发生低频振荡事件进行了现场调查,并在电力系统分析软件(BPA)和实时数字模拟仿真系统(real time digital simulator,RTDS)上对事件过程进行了仿真重现。通过对平班电厂的实际励磁调节器装置与RTDS互连闭环仿真试验,...对广西平班电厂机组发生低频振荡事件进行了现场调查,并在电力系统分析软件(BPA)和实时数字模拟仿真系统(real time digital simulator,RTDS)上对事件过程进行了仿真重现。通过对平班电厂的实际励磁调节器装置与RTDS互连闭环仿真试验,暴露了PSS2A模型由于计算不准确而产生在高频段(1 Hz以上)提供正阻尼、低频段(1 Hz以下)提供负阻尼的现象,从PSS2A模型的机理上分析了该现象产生的原因,并确定本次事件的主要原因是PSS2A模型的角速度信号被误屏蔽,导致了PSS在投入状态下提供负阻尼。展开更多
随着电力系统的发展,电力系统的稳定性受到低频振荡的威胁。电力系统稳定器(Power System Stabilizer,PSS)是抑制振荡,增强电力系统稳定性的重要措施。目前国内多采用PSS2B型PSS。PSS2B参数多,在投入运行时难以快速整定其所有的参数。...随着电力系统的发展,电力系统的稳定性受到低频振荡的威胁。电力系统稳定器(Power System Stabilizer,PSS)是抑制振荡,增强电力系统稳定性的重要措施。目前国内多采用PSS2B型PSS。PSS2B参数多,在投入运行时难以快速整定其所有的参数。运用最小二乘法进行曲线拟合的方法,在Matlab中编写程序可整定PSS2B的部分参数,从而实现快速准确地整定PSS2B的所有参数。将此软件在某机组的PSS参数整定中进行了验证,表明使用此整定软件能大大提高整定计算的效率和准确性,可广泛运用到实际工作中。展开更多
Theα-Ga2 O_(3)nanorod array is grown on FTO by hydrothermal and annealing processes.And a self-powered PEDOT:PSS/α-Ga_(2)O_(3)nanorod array/FTO(PGF)photodetector has been demonstrated by spin coating PEDOT:PSS on th...Theα-Ga2 O_(3)nanorod array is grown on FTO by hydrothermal and annealing processes.And a self-powered PEDOT:PSS/α-Ga_(2)O_(3)nanorod array/FTO(PGF)photodetector has been demonstrated by spin coating PEDOT:PSS on theα-Ga_(2)O_(3)nanorod array.Successfully,the PGF photodetector shows solar-blind UV/visible dual-band photodetection.Our device possesses comparable solar-blind UV responsivity(0.18 mA/W at 235 nm)and much faster response speed(0.102 s)than most of the reported self-poweredα-Ga_(2)O_(3)nanorod array solar-blind UV photodetectors.And it presents the featured and distinguished visible band photoresponse with a response speed of 0.136 s at 540 nm.The response time is also much faster than the other non-self-poweredβ-Ga_(2)O_(3)DUV/visible dual-band photodetectors due to the fast-speed separation of photogenerated carries by the built-in electric field in the depletion regions of PEDOT:PSS/α-Ga_(2)O_(3)heterojunction.The results herein may prove a promising way to realize fast-speed self-poweredα-Ga_(2)O_(3)photodetectors with solar-blind UV/visible dual-band photodetection by simple processes for the applications of multiple-target tracking,imaging,machine vision and communication.展开更多
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) incorporated with nanocrystalline TiO2 powder (PEDOT:PSS+nc-TiO2) films were prepared by spin-coating technique. SEM surface morphology, UV-Vis spectra and NH3 g...Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) incorporated with nanocrystalline TiO2 powder (PEDOT:PSS+nc-TiO2) films were prepared by spin-coating technique. SEM surface morphology, UV-Vis spectra and NH3 gas sensing of were studied. Results showed that the PEDOT:PSS+nc-TiO2 film with a content of 9.0 wt% of TiO2 is most suitable for both the hole transport layer and the NH3 sensing. The responding time of the sensor made from this composite film reached a value as fast as 20 s. The rapid responsiveness to NH3 gas was attributed to the efficient movement of holes as the major charge carriers in PEDOT:PSS+nc-TiO2 composite films. Useful applications in organic electronic devices like light emitting diodes and gas thin film sensors can be envisaged.展开更多
本文针对云南电网超低频振荡问题,对PSS4B和PSS2B两种电力系统稳定器(power system stabilizer,PSS)用于抑制超低频振荡进行了分析。首先建立了基于单机带负荷系统的线性化分析模型,给出了PSS能够抑制超低频振荡的理论依据,然后以单机...本文针对云南电网超低频振荡问题,对PSS4B和PSS2B两种电力系统稳定器(power system stabilizer,PSS)用于抑制超低频振荡进行了分析。首先建立了基于单机带负荷系统的线性化分析模型,给出了PSS能够抑制超低频振荡的理论依据,然后以单机带负荷系统和云南电网为算例,通过单机带负荷系统的开环相频特性、闭环特征根轨迹分析和时域仿真,以及云南电网的时域仿真,分析了PSS4B和PSS2B抑制超低频振荡的差异。所得结论对云南电网采用PSS抑制超低频振荡具有参考价值。展开更多
文摘对广西平班电厂机组发生低频振荡事件进行了现场调查,并在电力系统分析软件(BPA)和实时数字模拟仿真系统(real time digital simulator,RTDS)上对事件过程进行了仿真重现。通过对平班电厂的实际励磁调节器装置与RTDS互连闭环仿真试验,暴露了PSS2A模型由于计算不准确而产生在高频段(1 Hz以上)提供正阻尼、低频段(1 Hz以下)提供负阻尼的现象,从PSS2A模型的机理上分析了该现象产生的原因,并确定本次事件的主要原因是PSS2A模型的角速度信号被误屏蔽,导致了PSS在投入状态下提供负阻尼。
文摘随着电力系统的发展,电力系统的稳定性受到低频振荡的威胁。电力系统稳定器(Power System Stabilizer,PSS)是抑制振荡,增强电力系统稳定性的重要措施。目前国内多采用PSS2B型PSS。PSS2B参数多,在投入运行时难以快速整定其所有的参数。运用最小二乘法进行曲线拟合的方法,在Matlab中编写程序可整定PSS2B的部分参数,从而实现快速准确地整定PSS2B的所有参数。将此软件在某机组的PSS参数整定中进行了验证,表明使用此整定软件能大大提高整定计算的效率和准确性,可广泛运用到实际工作中。
基金Project supported by the National Natural Science Foundation of China(Grant No.61705155)。
文摘Theα-Ga2 O_(3)nanorod array is grown on FTO by hydrothermal and annealing processes.And a self-powered PEDOT:PSS/α-Ga_(2)O_(3)nanorod array/FTO(PGF)photodetector has been demonstrated by spin coating PEDOT:PSS on theα-Ga_(2)O_(3)nanorod array.Successfully,the PGF photodetector shows solar-blind UV/visible dual-band photodetection.Our device possesses comparable solar-blind UV responsivity(0.18 mA/W at 235 nm)and much faster response speed(0.102 s)than most of the reported self-poweredα-Ga_(2)O_(3)nanorod array solar-blind UV photodetectors.And it presents the featured and distinguished visible band photoresponse with a response speed of 0.136 s at 540 nm.The response time is also much faster than the other non-self-poweredβ-Ga_(2)O_(3)DUV/visible dual-band photodetectors due to the fast-speed separation of photogenerated carries by the built-in electric field in the depletion regions of PEDOT:PSS/α-Ga_(2)O_(3)heterojunction.The results herein may prove a promising way to realize fast-speed self-poweredα-Ga_(2)O_(3)photodetectors with solar-blind UV/visible dual-band photodetection by simple processes for the applications of multiple-target tracking,imaging,machine vision and communication.
文摘Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) incorporated with nanocrystalline TiO2 powder (PEDOT:PSS+nc-TiO2) films were prepared by spin-coating technique. SEM surface morphology, UV-Vis spectra and NH3 gas sensing of were studied. Results showed that the PEDOT:PSS+nc-TiO2 film with a content of 9.0 wt% of TiO2 is most suitable for both the hole transport layer and the NH3 sensing. The responding time of the sensor made from this composite film reached a value as fast as 20 s. The rapid responsiveness to NH3 gas was attributed to the efficient movement of holes as the major charge carriers in PEDOT:PSS+nc-TiO2 composite films. Useful applications in organic electronic devices like light emitting diodes and gas thin film sensors can be envisaged.
文摘本文针对云南电网超低频振荡问题,对PSS4B和PSS2B两种电力系统稳定器(power system stabilizer,PSS)用于抑制超低频振荡进行了分析。首先建立了基于单机带负荷系统的线性化分析模型,给出了PSS能够抑制超低频振荡的理论依据,然后以单机带负荷系统和云南电网为算例,通过单机带负荷系统的开环相频特性、闭环特征根轨迹分析和时域仿真,以及云南电网的时域仿真,分析了PSS4B和PSS2B抑制超低频振荡的差异。所得结论对云南电网采用PSS抑制超低频振荡具有参考价值。
