Over-frequency Generator Tripping Control of Sending-end System Considering Transient Instability Generating Units

2020 ◽  
Author(s):  
Jihong Tang ◽  
Hongbin He ◽  
Gaocai Yang ◽  
Shuai Xiao ◽  
Sirui Zhu
Keyword(s):  
Frequency Generator ◽  
Transient Instability

scholarly journals Stereoscopic PIV measurements using low-cost action cameras

2021 ◽  
Vol 62 (3) ◽  
Author(s):  
Theo Käufer ◽  
Jörg König ◽  
Christian Cierpka
Keyword(s):  
Continuous Wave ◽  
Low Cost ◽  
Frame Rate ◽  
Processing Scheme ◽  
Piv Measurements ◽  
Stereoscopic Piv ◽  
Cost Action ◽  
Image Velocimetry ◽  
Frequency Generator ◽  
Educational Applications

Abstract Recently, large progress was made in the development towards low-cost PIV (Particle Image Velocimetry) for industrial and educational applications. This paper presents the use of two low-cost action cameras for stereoscopic planar PIV. A continuous wave laser or alternatively an LED was used for illumination and pulsed by a frequency generator. A slight detuning of the light pulsation and camera frame rate minimizes systematic errors by the rolling shutter effect and allows for the synchronization of both cameras by postprocessing without the need of hardware synchronization. The setup was successfully qualified on a rotating particle pattern in a planar and stereoscopic configuration as well as on the jet of an aquarium pump. Since action cameras are intended to be used at outdoor activities, they are small, very robust and work autarkic. In conjunction with the synchronization and image pre-processing scheme presented herein, those cameras enable stereoscopic PIV in harsh environments and even on moving experiments. Graphic abstract

Individual Differences in Attention and the Prediction of Flight Criteria

1971 ◽  
Vol 33 (3_suppl) ◽  
pp. 1335-1342 ◽  
Author(s):  
Daniel Gopher ◽  
Daniel Kahneman
Keyword(s):  
Individual Differences ◽  
Selective Attention ◽  
Dichotic Listening ◽  
High Performance ◽  
The Other ◽  
Listening Test ◽  
Transient Instability ◽  
High Performance Aircraft

A dichotic listening test was constructed which requires S to monitor a relevant message and to ignore a concurrent message presented to the other ear. The test has promising validity for predicting different criteria of proficiency in flying high-performance aircraft. An analysis of the most valid type of errors suggests that a change in an existing orientation is accompanied by a transient instability of selective attention. Most errors in continuous attention are omissions, which indicate a failure of the listening set. Intrusions, which indicate a failure of selectivity, are rare and their frequency is not correlated to flight criteria.

THE TRANSIENT INSTABILITY OF TENSIOMETER READINGS DURING INFILTRATION

Soil Science ◽  
1991 ◽  
Vol 152 (3) ◽  
pp. 231-235 ◽  
Author(s):  
GRANT W. THOMAS ◽  
RONALD E. PHILLIPS
Keyword(s):  
Transient Instability

Phase-locked widely tunable optical single-frequency generator based on a femtosecond comb

2005 ◽  
Vol 30 (17) ◽  
pp. 2323 ◽  
Author(s):  
T. R. Schibli ◽  
K. Minoshima ◽  
F.-L. Hong ◽  
H. Inaba ◽  
Y. Bitou ◽  
...  
Keyword(s):  
Single Frequency ◽  
Frequency Generator

Optimizing the Allocation of the Relay Setting Related to Power Grid and over Frequency Generator Tripping Scheme

2014 ◽  
Vol 986-987 ◽  
pp. 404-411
Author(s):  
Qi Yang ◽  
Xin Zeng ◽  
Qing Kui Guo ◽  
Yong Yu Yuan ◽  
Jian Jun Sun ◽  
...  
Keyword(s):  
Power System ◽  
Steam Turbine ◽  
Power Unit ◽  
Program Analysis ◽  
Thermal Power ◽  
Protection Device ◽  
Power Network ◽  
Whole Process ◽  
Islanding Operation ◽  
Frequency Generator

Through the summary of typical accident, the problem between the over speed protection device of thermal power unit steam turbine and over frequency generator tripping measure is analyzed in island operation of sending ends of regional grid. The optimizing allocation principle between over frequency generator tripping measure and over speed protection equipment is put forward. By a variety of program analysis and comparison, the optimizing scheme is given. Finally, the typical models of thermal power unit steam turbine over speed protection are established in software. Based on a practical power system as an example, the whole process of islanding is simulated. Checking the coordination with existing over frequency generator tripping measure and the relay setting related to power network in the islanding operation, the validity and practicability of the optimal scheme and principle are analyzed. With the method, the regional grid will remain safe and stable.

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