Papers by Keyword: Failure Rate

Abstract: The effectiveness of the functioning communication management systems with the information security system is analyzed on the example critical information infrastructure objects. Based on the study, a new approach is proposed to obtain analytical estimates security and reliability indicators hardware and software complexes critical information infrastructure management systems. The given formulas for calculating the intensities of the states telecommunication systems allow to expand the number indicators information security and reliability functioning, if necessary.

Abstract: The design of robust power semiconductor devices and the assessment of their susceptibility to terrestrial cosmic rays induced failures requires the accurate characterization of the device-internal electric field. This work presents a non-invasive cryostatic spectrometry technique making use of a soft-gamma Am²⁴¹ radioactive source, to sense the device-internal electric field of silicon carbide power devices, through the measurement of the carriers’ multiplication factor. TCAD and Monte Carlo simulations tools are coupled to predict the soft-gamma irradiation spectra and to localize the hotspots for charge multiplication in the device structure. An empirical relationship is derived to convert the carriers’ multiplication factor measured at cryogenic temperature to the multiplication factor at ambient temperature. Finally, by highlighting the correlation between the multiplication factor and the failure rate of power devices exposed to terrestrial cosmic radiation, the technique is proposed as a complimentary method for the on-field assessment of the Safe-Operating Area.

Abstract: This article deals about specific application of RFID technology in safety area of railway cargo transport. The goal is utilization of this technology in interaction with most common interferences on cargo railway wagons, which causes not only higher costs of repair of these wagons, but by substantial impact increase also the risk of danger accident. The essence of article is formed by draft of specific RFID tags on chosen elements of chassis of cargo railway wagon.

Abstract: The computation of security risk index in identifying the system’s condition is one of the major concerns in power system analysis. Traditional method of this assessment is highly time consuming and infeasible for direct on-line implementation. Thus, this paper presents the application of Multi-Layer Feed Forward Network (MLFFN) to perform the prediction of voltage collapse risk index due to the line outage occurrence. The proposed ANN model consider load at the load buses as well as weather condition at the transmission lines as the input. In realizing the effectiveness of the proposed method, the results are compared with Generalized Regression Neural Network (GRNN) method. The results revealed that the MLFFN method shows a significant improvement over GRNN performance in terms of least error produced.

Abstract: In this paper, we propose a new method, namely equivalent condition score (CS) method, to calculate the failure rate of power transmission equipment with condition maintenance. Through the conversion of the CS evaluated after maintenance, we can investigate the effect of maintenance on the failure rate, and then calculate the failure rate of the equipment. The effectiveness of the proposed method is verified by field maintenance data. As shown in this paper, the equivalent CS method has a simplified calculation process and specific physical meaning.

Abstract: In the traditional outage model, the failure rate of the wind turbine is often given as a long-term statistics value on average, that is only one value for a wind turbine, this calculation method is not reflect the real reliability level of wind turbines. According to historical failure data, the factors that affect the wind turbine outage are divided into several categories. Based on Markov Process, the calculation methods for wind turbine failure rate under single factor and multi-factor are given respectively. On this basis, the calculation methods for wind turbine failure rate under different levels of single factor and multi-factor are given respectively based on statistical analysis method. Because different factors are taken into account in the failure rate calculation, the failure rate will change according to the actual factors and then it could reflect the real risk level of power systems when uses this failure rate. Simulation calculation is carried out on a real wind farm; the results show the effectiveness of this proposed method.

Abstract: In this paper, we introduce a prediction method for air material failure prediction. Firstly, we studied the feature of air material and previous studies on its failure prediction; we then established an air materiel failure prediction model based on Weibull analysis; then we proposed methods to improve the performance of the model through data processing and model adjustment; then, we used our model to estimate the product life cycle and predict the failure of air material based on a data sample.we not only demonstrate the validity of the model and presents a weibull analysis operation steps through the case analysis. Finally, we made some conclusions of this paper and proposed some suggestions for future research.

Abstract: This paper introduces a new method, named E-Bayesian estimation method, to estimate failure rate in zero-failure data. The definition of E-Bayesian estimation of the failure rate is given, based on the definition, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation of the failure rate were provided, and properties of the E-Bayesian estimation, i. e. relations between E-Bayesian estimation and hierarchical Bayesian estimation, was discussed. Calculations were performed on practical problems, showing that the proposed new method is feasible and easy to operate.

Abstract: The reliability assessment of power system components is the key to power system safe and reliable operation. According to the record of actual operation of power system components characteristics, a practical method of reliability evaluation for fault date which is missing components is introduced in this paper. The method is based on Weibull distribution model. It is also a calculation and solving methods of reliability evaluation fault system of missing data components. The system mainly includes sample selection of data, parameter calculation, model checking and failure rate curve drawing. So the transformer as an example, verify the effectiveness of this method. In addition the paper analyses the influencing factors in the transformer reliability, such as voltage grade, manufacturer and product types. In a word, this model provides a systematic and effective method for the practical application of the reliability evaluation of the electrical components.

Abstract: The fault data of 133 Xiali taxis in Xingtai Car Rental Company are collected and the preliminary sorting is conducted to them. The automobile preventive repair model is established and the analysis of the necessity and feasibility of preventive repair is performed. In the base of reliability analysis of fault data, the failure rule is obtained and the optimal repair cycle is found out.