scholarly journals An improved simulated load test system

2021 ◽  
Vol 2093 (1) ◽  
pp. 012019
Author(s):  
Liang Hua ◽  
Jiaen Qi ◽  
Wei Huang ◽  
Sijiang Zhang ◽  
Feng Gao ◽  
...  

Abstract A miniaturized analog load-checking relay protection test device is developed in this paper, in which a high-precision wireless phase volt-ampere test device is configured. This device, characterized by intelligence and ease of operation, realizes the detection of the transformation ratio, polarity, phase, etc. of the secondary wiring of the transformer in the smart substation merging unit and the conventional substation. It meets the testing requirements of smart substations, and can test bus differential protection, line protection, and various protections such as main transformer differential.

Author(s):  
Bing Ji ◽  
Xiaolei Yang ◽  
Chenyang Liu ◽  
Haihang Xu ◽  
Yuyang Ji ◽  
...  
Keyword(s):  

Author(s):  
Blaine M. Wruck ◽  
Erdem Coleri ◽  
Richard Villarreal ◽  
Vikas Kumar ◽  
James Batti

In light of the various quality assurance (QA) issues pertaining to tack coats that occur during construction, there is a need for a means of verifying interlayer bond quality in situ. Despite the immense use of tack coat as a constituent in paving, there are no construction specifications with provisions for the quantification of tack coat bond quality in laboratory or field settings. In this study, a construction QA process for tack coat bond performance was proposed. A novel field tack coat bond strength test device, TackBond, was developed and used for this purpose. The performance of engineered (new tack coat technologies that are tracking less) and conventional tack coats was also evaluated in the laboratory and the field using the developed TackBond test system. The TackBond device was improved in this study by adding features that render it more practical, portable, accurate, and better suited for a variety of pavement surface conditions. Engineered tack coat performance was compared with that of tack coats used conventionally on both milled and overlay surface types. The suitability of the TackBond Test device for capturing the true response of each tack coat was first evaluated by comparing results from TackBond laboratory tests with monotonic direct shear tests (DST) on laboratory-produced samples. Strong correlations between the two test types were achieved. Results of field and laboratory TackBond tests showed that the in situ QA control process developed in this study could be effectively used to improve the in situ tack coat bond performance.


2013 ◽  
Vol 722 ◽  
pp. 282-286
Author(s):  
Hong Hua He

The microprocessor-relay protection device has gradually replaced regular simulation relay protection it is also difficult to visually determine protection device malfunction or tripping. Therefore, the use of the Mat lab toolbox to build transformer differential protection simulation model, the simulation results show that two-line ratio brake can correctly identify internal fault current, and rapidly remove fault, and the system also can provide convenient for microprocessor transformer protection.


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