Advanced Materials Research Vols. 986-987

Abstract: In view of the nonlinear, fuzzy relationship between fan fault reason and fault symptom, put forward a kind of threshold diagnosis strategy combined with fuzzy rules and case reasoning. Using a fan fault vector through fuzzy fault diagnosis model to compare with a given threshold, then generate the initial fault solution set, and finally using case-based reasoning thinking, accurate fault location. Then we verify the method’s effectiveness through a fault analysis of fan rotor vibration. The results show that the combination with fuzzy rules and case reasoning can effectively solve the problem of multi factors of failure reasons.

Abstract: An experimental technique was designed to measure the gas number density distribution of alkali vapor by tunable diode laser absorption spectroscopy. The measurement method was developed by scanning multiple gas absorption lines and fitting the experiment data with Lorentz profile to obtain the density. A discretization strategy of the equation for absorption lines is also present here as well as a constrained liner least-square fitting method. A simulation model was set up to reconstruct the two-dimensional distribution of number density and the feasibility of the reconstruction was verified. In the end, this work demonstrates the calculation error of the acquired number density and the distribution. The results indicated that the error would be no more than 5% if the measurement error is less than 9%.

Abstract: Energy measurement and computing can directly reflect the value of natural gas. In our country the volume flow measurement and computing will be gradually replaced by energy measurement. In this paper the principle of energy metering of natural gas is introduced and the system of energy metering of natural gas is constructed. Based on GB/T 11062, computing method of gas energy is discussed, in which quality data of natural gas, temperature, flow, pressure parameters are measured by energy metering system and the calorific value of natural gas, relative density and Wobbe index are and computed. Also the uncertainty of and computing method for natural gas energy is analyzed in which uncertainty is within 0.1%. The results show that the uncertainty of the calorific value measurement system attained accuracy requirements of GB/T 18603-2001.

Abstract: The goal of this paper is to present a new innovative method of getting test data for boundary scan interconnection test in multiple scan chains, so to decrease the test time and increase the efficiency and reliability. Firstly, a new model of configuring and optimizing multiple scan chains is formed based on the researches on greedy strategy for configuring multiple scan chains for internal test and the sorting algorithm of single scan chain for Cluster test. Then, a method of establishing test project description file (TPDF) is presented in order to get the test data quickly and effectively. During the testing of two different boundary-scan circuit boards, all faults can be detected. Experiment results show that the expected objective is achieved.

Abstract: Solar array is the important part of the satellite’s Electrical Power Supply, the failure of the solar array may lead to the loss of some or all of the satellite’s functions, so fault location in time and solution strategy of solar array is particularly important. The thesis studied the on-orbit failure of GEO satellite’s solar array, analyzed the fault location according to the related telemetry, and researched the solution of all kind of the faults. The thesis contributes to the satellite control center to locate faults in time and the satellite manufacture to improve the design of the solar array, it is helpful to improve the reliability and safety of the satellite’s on-orbit running.

Abstract: The primary method of power system fault diagnosis is that the fault section estimation is demonstrated a 0-1 programming model according to the acting theory of protective relays. This paper proposed a kind improved artificial fish-swarm algorithm: binary artificial fish-swarm algorithm (BAFA) for this kind of problem. Forward speed of optimal direction between swarm-behavior and follow-behavior is analyzed and a comparative analysis is made with genetic algorithm (GA) on this basis. Results indicate that follow-behavior is superior to swarm-behavior on forward speed of optimal direction and BAFA is superior to GA on the comprehensive performance. Meanwhile, it is shown that BAFA has the fast convergence speed and better optimization ability.

Abstract: We had described and discussed the testing methods of varistor tester about DC reference current, varistor voltage, leakage current, voltage ratio, and provided the corresponding test data,which has proved that the methods are feasible.

Abstract: Electric power optic cables, as infrastructure facilities of the power communication system, are commonly affiliated to primary towers and poles of power transmission lines. And their safe and stable operation is one of important factors to guarantee the reliable power supply. At present, there are many kinds of professional application systems for equipment management in the field of Power System, so the level of their automation and intelligence is relatively high. But Management and Monitoring of outdoor lines are still staying the same as traditional methods, becoming a vulnerable part in smart grid. This paper introduces a network management system of electric power optic cables based on GIS and referred to the design method of Transmission Network Management System (TNMS). Its aims and several main developing technologies are also discussed. This system will play an important role in improving maintenance management and operational reliability for the power communication network.

Abstract: According to the new processing requirements of lightning full-wave with oscillation in IEC60060-1 Ed.3.0, a impulse measurement calculation program based on Labview has been designed. The method of starting point determination and curve fitting has been introduced. Ordered sample mean clustering thinking was used to find the chopping point of lighting impulse tail-chopping waveform. Waveforms in TDG(test data generator)2.0.6 in IEC61083-2Ed2.0 were used to check the accuracy of the calculation program. The uncertainty of test results has also been estimated. Test results show that this calculation program meets the requirements in IEC61083-2. When the calculation program was used with oscilloscope or data capture card,the accuracy of impulse measurement system can be ensured. It is of significant importance in impulse measurement research.

Abstract: Double circuit transmission line is an important part of the power grid, which is vulnerable to lightning and may endanger the security and stability of the power grid. In order to design a sensor which can monitor the lightning traveling wave current on double circuit transmission line, simulations of lightning on the double circuit transmission line were conducted. The simulation result shows that besides high frequency components, the traveling wave contains a lot of low frequency components. Based on the equivalent model and the frequency response of the self-integrated Rogowski coil, it turns out that the widely used self-integrated Rogowski coil is not suitable for this application as the problem of low frequency distortion. In this paper, through theoretical analysis and simulations in Matlab, an improved Rogowski coil with analog integrator is proposed which can correct the low frequency distortion of the self-integrated Rogowski coil. All the simulations, experiments and operating data installed to a double circuit transmission line in China verify the validity of the high bandwidth Rogowski coil.