Research on Distribution Transformer Condition Assessment Method Based on Core State Variable Set

2014 ◽  
Vol 700 ◽  
pp. 83-87
Author(s):  
Bing Bao ◽  
Li Ming Bo ◽  
Yang Xu

According to the problems that there are less distribution transformer state variables and the condition assessment of distribution transformer carry out difficultly, a method of distribution transformer condition assessment based on core state variables is presented. The initial results of distribution transformer condition assessment are obtained by using core state variables. Then through calculating the sensitivity of the non-core state variables to the evaluation results, the initial assessment results are modified to ensure more accurate results.

2013 ◽  
Vol 433-435 ◽  
pp. 1245-1249
Author(s):  
Hai Feng Liang ◽  
Zi Xing Liu

Compared with the transmission transformer condition assessment, less data is one of the major problems that limit distribution transformer condition assessment work. This paper intends to solve this problem through reducing state variables dimensionality. First, through analyzing the principle of every state variables of distribution transformer by use of the maximum Eigen-value approach, the core state collection of assessing the distribution transformer is formed and the state variables dimensionality is reducing. Then, the initial results of distribution transformer condition assessment are obtained by using core state variables. Thirdly, the sensitivity of the non-core state variables to the evaluation results is calculated. Finally, the initial assessment result is modified considering the non-core state variables change and the sensitivity to get the final result. Through the above proposed method, the evaluation process need only consider the core state variables and the change of non-core state variables. This method not only reduces the demand for data, but also ensures accuracy of the results using the sensitivity correction. The results of a condition assessment instance of distribution transformer verify the validity of the method.


Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 207
Author(s):  
Sining Huang ◽  
Yupeng Chen ◽  
Xusheng Feng ◽  
Tiantian Qiao ◽  
Dandan Yu ◽  
...  

In view of the ambiguity and randomness of the assessment of earthquake scene rescue performance, this paper proposes an integrated assessment method considering quantitative and qualitative influencing factors from three levels: search, rescue and medical treatment. Firstly, this study constructs an assessment index system of rescue performance at the earthquake scene based on the International Search and Rescue Advisory Group (INSARAG) guidelines set by International Search and Response. Secondly, the subjective weights and objective weights of each index were calculated using the hierarchical analysis process (AHP) and cloud model, respectively. The comprehensive weights were calculated using weighted analysis, and the performance assessment results were visually expressed by cloud model images. Finally, the study was applied to an earthquake rescue case with an initial assessment of 4.0065, and its performance was improved by 4.36% when the rescue process was optimized. The assessment results show that earthquake rescue performance can be estimated, and the rationality and effectiveness of the method was validated.


Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 219 ◽  
Author(s):  
Alberto Sanchez ◽  
Elías Todorovich ◽  
Angel de Castro

As the performance of digital devices is improving, Hardware-In-the-Loop (HIL) techniques are being increasingly used. HIL systems are frequently implemented using FPGAs (Field Programmable Gate Array) as they allow faster calculations and therefore smaller simulation steps. As the simulation step is reduced, the incremental values for the state variables are reduced proportionally, increasing the difference between the current value of the state variable and its increments. This difference can lead to numerical resolution issues when both magnitudes cannot be stored simultaneously in the state variable. FPGA-based HIL systems generally use 32-bit floating-point due to hardware and timing restrictions but they may suffer from these resolution problems. This paper explores the limits of 32-bit floating-point arithmetics in the context of hardware-in-the-loop systems, and how a larger format can be used to avoid resolution problems. The consequences in terms of hardware resources and running frequency are also explored. Although the conclusions reached in this work can be applied to any digital device, they can be directly used in the field of FPGAs, where the designer can easily use custom floating-point arithmetics.


1974 ◽  
Vol 96 (2) ◽  
pp. 193-203 ◽  
Author(s):  
J. K. Hedrick ◽  
G. F. Billington ◽  
D. A. Dreesbach

This article applies state variable techniques to high speed vehicle suspension design. When a reasonably complex suspension model is treated, the greater adaptability of state variable techniques to digital computer application makes it more attractive than the commonly used integral transform method. A vehicle suspension model is developed, state variable techniques are applied, numerical methods are presented, and, finally, an optimization algorithm is chosen to select suspension parameters. A fairly complete bibliography is included in each of these areas. The state variable technique is illustrated in the solution of two suspension optimization problems. First, the vertical plane suspension of a high speed vehicle subject to guideway and aerodynamic inputs will be analyzed. The vehicle model, including primary and secondary suspension systems, and subject to both heave and pitch motions, has thirteen state variables. Second, the horizontal plane suspension of a high speed vehicle subject to guideway and lateral aerodynamic inputs is analyzed. This model also has thirteen state variables. The suspension parameters of both these models are optimized. Numerical results are presented for a representative vehicle, showing time response, mean square values, optimized suspension parameters, system eigenvalues, and acceleration spectral densities.


2009 ◽  
Vol 129 (1) ◽  
pp. 174-181 ◽  
Author(s):  
Hiroyuki Shinkai ◽  
Hisashi Goshima ◽  
Masafumi Yashima

Author(s):  
Debarun Bhattacharjya ◽  
Dharmashankar Subramanian ◽  
Tian Gao

Many real-world domains involve co-evolving relationships between events, such as meals and exercise, and time-varying random variables, such as a patient's blood glucose levels. In this paper, we propose a general framework for modeling joint temporal dynamics involving continuous time transitions of discrete state variables and irregular arrivals of events over the timeline. We show how conditional Markov processes (as represented by continuous time Bayesian networks) and multivariate point processes (as represented by graphical event models) are among various processes that are covered by the framework. We introduce and compare two simple and interpretable yet practical joint models within the framework with relevant baselines on simulated and real-world datasets, using a graph search algorithm for learning. The experiments highlight the importance of jointly modeling event arrivals and state variable transitions to better fit joint temporal datasets, and the framework opens up possibilities for models involving even more complex dynamics whenever suitable.


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