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The opportunity to clarify the methods of calculation and regulation of technological power losses by applying iterative method based integrated model state 0.4–35kV wire transmission lines is presented. The method of determining the model parameters and calculation results is presented too. The area of further research is identified.
Aspects of mathematical model formation in terms of baking time influence on the resistance to stress corrosion cracking under tension are considered in the article. The approximation of experimental data in the Mathcad environment was carried out. The adequate mathematical models and plots describing the dependence of the applied stress tension and time before cracking on the baking time were obtained.
Service lifetime estimation for earth grounding grids as a problem or a task faced by the industry is presented. A mathematical model based on Freschi's semianalytical model to determine the performance of the earth grounding grid at a certain year after being buried is proposed. The mathematical model can also explain the performance degradation of the earth grounding grid in principle and mathematically...
In this essay, in the view of the ground grid corrosion problem, we establish a theoretical calculation model and engineering application model based on the way changing the current injection position and multiple measuring at each position. Finally, proposing a corresponding optimization algorithm on the basis of analyzing the characteristics of the problem. There are too many redundant equations...
Face on the problems of existed method of substation ground grid corrosion searching, like blindness, heavy workload, low working efficiency. Through the analysis of the ground grid fault diagnosis theory, using the theory of electric network and ideas of matrix, we can construct fault diagnosis equations. Introducing lowest energy principle and advanced optimization algorithm, substation ground grip...
This paper presents a comprehensive optimization method for the diagnosis of large substation steel grounding grid integrity status, and the detection and location of any corrosion spot before digging out the grounding grid. A grounding grid is modeled as a circuit network, and fault diagnosis equations are derived by applying Tellegen's theorem, optimization theory and fault diagnosis theory for...
The grounding system is made of steel in most of developing countries. When the steel is eroded, it is a potential problem and very dangerous to the power system. So, the fault diagnosis on grounding grids is of great economic value for the safety operation in electric power system. In this paper, a simulation computation method is presented by means of a nonlinear model. Via this method, the real...
This paper establishes a unequal potential grounding grid model which is different from previous model where the grounding grid is equivalent to a electric network composed of resistors, based on the principle of uniting field and circuits while considering the resistor, self-inductance, mutual inductance and leakage current of inductor .In this model ,the corrosion diagnosis equation is setting up...
The steel grounding grid buried in earth will corrode and become hidden danger to the safety of power system. It is important to examine the state of grounding. Particle swarm optimization (PSO) is a population-based, self-adaptive search optimization technique. This paper used combination of rotating and encouraging each location and incentives, many measurement method, established a new non-linear...
Hazard and reliability prediction of an engineering asset is one of the significant fields of research in engineering asset health management (EAHM). In real-life situations where an engineering asset operates under dynamic operational and environmental conditions, the lifetime of an engineering asset can be influenced and/or indicated by different factors that are termed as covariates. The explicit...
The grounding grid is commonly installed in the substation. When itpsilas damaged, restoring and improving work not only affects the production, but also it is difficult to carry it out. In this paper, by using integrated translation and iterative method, we establish a new optimization model of quadratic programming with constraints. By solving the model, we can obtain the resistance of each branch...
To improve the efficiency of the corrosion diagnosis, based on the hierarchical model, an actual grounding grid can be divided into six levels, such as actual grids, quasi- circuit-domain, circuit-domain, circuit-network, touchable network and intrinsic network. Based on above model, a novel node partition based approach is put forward. In which, a grounding grid is divided into several small-scale...
A set of uncertain branches related with each other is defined as an uncertain branch group for grounding grid corrosion diagnosis. The methodology to determine uncertain branch groups is described. It is pointed out that evaluation of uncertain branches can be carried out in uncertain branch groups, respectively. A novel method based on dichotomy to calculate the maximum and minimum resistances of...
To benefit the corrosion diagnosis, the concept of uncertain branch group and its corresponding prototype are defined. A node partition method is presented to divide the intrinsic network into several small sub-networks to solve. A set of linear equations about conductance of the intrinsic branches is deduced based on KCL equations. The nonlinear iteration is avoided. An approach to calculate the...
The requirements of a good test scheme are described, such as independent excitation, none-repeated measurement, large voltage signals and sensitive to the changes of branch resistances. Reciprocity theorem and superposition theorem can be used to determine whether a test scheme is completed. Theorem of Maximum Voltage is proved through reduction to absurdity, and its three inferences are put forward,...
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