An Advanced Fuzzy Logic Based Method for Power Transformers Assessment
Si Huy Cuong Nguyen,
Thanh Phong Mai
Issue:
Volume 10, Issue 5, September 2021
Pages:
74-81
Received:
28 August 2021
Accepted:
11 September 2021
Published:
26 September 2021
Abstract: Dissolved Gas Analysis is an effective method for detecting faulty power transformers in their early stages. However, technical interpretation of results can be complex and highly dependent on the experience of experts. This paper presents an attempt to detect power transformer incipient fault via gas concentrations obtained from oil sampling and Dissolved Gas Analysis. The proposed method uses a sophisticated fuzzy logic system to perform fault type classification. Ratios and relative percentages of 5 key gases (Hydrogen, Methane, Ethane, Ethylene, and Acetylene) are taken as input variables, then the fuzzy system will try to generate an output vector that indicates six basic fault types, including partial, low, and high energy discharges as well as three ranges of thermal fault. This method can be easily implemented in any environment that supports basic mathematical operators. To demonstrate how the proposed fuzzy logic method works, the authors developed an offline MATLAB script and an online web-based application that can provide multiple assessments by various methods simultaneously. The set of membership functions and fuzzy rules presented in this paper allows the detection of multiple faults at once. Performance tests on many actual data sets show that the proposed method achieves better accuracy than the traditional ratio codes, even on a par with state-of-the-art graphical-based tools such as the Duval triangle or pentagon.
Abstract: Dissolved Gas Analysis is an effective method for detecting faulty power transformers in their early stages. However, technical interpretation of results can be complex and highly dependent on the experience of experts. This paper presents an attempt to detect power transformer incipient fault via gas concentrations obtained from oil sampling and D...
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Power Market Operation Efficiency Evaluation Based on a Hybrid BP Neural Network: A perspective from Market Regulator in China
Jun Dong,
Yao Liu,
Zhenjie Chen,
Yaoyu Zhang,
Yuzheng Jiang
Issue:
Volume 10, Issue 5, September 2021
Pages:
82-99
Received:
30 October 2021
Accepted:
16 November 2021
Published:
23 November 2021
Abstract: The electricity market reform in China promotes the marketization process of the electricity market, but in this process, there are still some behaviors that disturb the market order. The operation of electricity market needs to be evaluated in order to evaluate its operation efficiency, and the regulatory agency is an important part of it, so it is very necessary to construct the evaluation index and method of the operation efficiency of electricity market from the perspective of the regulatory agency. This paper constructed an evaluation system of power market operation efficiency based on hybrid BP neural network. In the construction of methods, appropriate evaluation methods become very necessary when considering the uncertainty and ambiguity of the assessed things. Based on the above analysis, this paper constructed an evaluation index system of power market operation efficiency based on SCP model, and constructed evaluation methods based on fuzzy Delphi, fuzzy AHP and neural network. Finally, this paper selects the actual data of a certain region for example verification, and conducts sensitivity analysis to analyze the factors that have a key impact on the efficiency of market operation, and draws the conclusion of this paper. This paper hopes that the research results can be applied to the decision-making of regulators in order to make the electricity market run efficiently.
Abstract: The electricity market reform in China promotes the marketization process of the electricity market, but in this process, there are still some behaviors that disturb the market order. The operation of electricity market needs to be evaluated in order to evaluate its operation efficiency, and the regulatory agency is an important part of it, so it i...
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