Abstract: This paper gives a new method of rough set-based on taste signals identification. Further improve the identification accuracy by dividing regions more appropriate. The simulation data and the latest UCI machine learning taste signal data (Wine Quality) are used to verify the new method, and the new method is compared with other identification algorithms. The results fully show the correctness and effectiveness of the proposed identification method based on rough set.
Abstract: Battery, as one of the important parts in satellite electrical power system, is of a high probability of failure, therefore it is especially important to simulate and analysis. Base on the existing satellite power system simulation platform, this paper analysis on the fault of Low Earth Orbit (LEO) satellites lithium-ion (Li-Ion) battery. Storage battery, battery charge regulator (BCR) and battery discharge regulator (BDR) are modeled and simulated, and the models are built in Matlab/Simulink. The simulation results are realistic, and these models are effective methods for power design and fault recovery.
Abstract: This paper analyzes the traditional structure and the simulation function of training simulation system in the intelligent substation, put forward a kind of intelligent substation simulation training system, can promote on running personnel training, and utilize effectively of the substation simulation training system.
Abstract: In order to obtain the optimal situation of the output shaft load in different bearing support system, this paper has established output shaft load calculation model in one bearing, double bearings and three bearings support system to compare the calculation results. Use equivalent output shaft to do theoretical calculation and use finite element method to calculate the strength and stiffness of the uniform output shaft for comparison among three types of support. The results shows that stress value of output shaft with theoretical calculation is closed to the value with finite element method, but reverse as the deformation of output shaft, and the optimization values are less than 1% with three supporting bearings.
Abstract: The large rotating machinery functioning of the rotor is one of the most important issues. It has great significance to identify the fault early and implement intelligent fault diagnosis. However there is a big nonlinear about large rotating machinery and has less fault samples. This led great difficulties for feature selection and state recognition. Based on Entropy in feature selection, we extract each intrinsic mode’s function energy as eigenvector and make them for input parameter of the support vector machine (SVM) to fault diagnosis. The experiment shows that this method can classify the fault state, and completed intelligent fault diagnosis.
Abstract: We present a combined electromagnetic method which consist of Audio Magnetotellurics (AMT) and Transient Electromagnetic method (TEM) to the utilize in the selecting sites for ultra high voltage power plant. The inversion profile gives the underground resistivity distribution for the power engineers to select proper ground site location. The result is satisfactory and some ground sites have been established already, indicating that electromagnetic method is suitable for selecting the ground site for ultra high voltage power plant.
Abstract: Some flashover incidents of high-voltage transmission lines are reported to be induced by fire. Though the mechanism of fire induced flashover is not well understood, it is deemed that fire could reduce the insulation strength of air. This paper has compared the breakdown characteristics of gaps in normal air conditions and those in fire. The results show that the breakdown voltage or electric field strength of gaps in fire decreases greatly. The value of breakdown electric field strength in alcohol flame is about 1.454 KV/cm, which is only about 28.8% of that in air. The value of breakdown electric field strength in wood crib fire is about 0.300KV/cm, corresponding to 19.9% of that in air. This study demonstrates that flame and soot particle of fire are responsible for fire induce flashover of high-voltage transmission lines.
Abstract: It is very important to study the overvoltage protection and insulation coordination of the converter stations for the ±800kV UHVDC transmission project because of its importance in the power grid. The paper studies two kinds of arrester arrangements of the converter stations in the Nuozhadu to Guangdong ±800kV UHVDC power transmission project by using the PSCAD/EMTDC program. The simulation results show that the protective level of arresters is different, while the insulation levels of critical equipments in the converter station are almost the same under these two arrester arrangement schemes.
Abstract: In order to meet the urgent needs of voltage measurement traceability and transfer in the construction of ultra-high voltage power grid, 1000kV series standard voltage transformer is developed as the standard instrument, and then its measurement characteristics is tested. According to the theory and construction of the series power frequency voltage ratio standard, semi-insulating transformer voltage summation is proposed to make the voltage ratio measurement of SSTV whose accuracy can reach the 0.02 level trace to the source of national power frequency ratio standard of 500kV successfully. The compatibility is better than compared to traditional voltage coefficient measuring method.
Abstract: Due to the voltage surge and transient disturbances can cause malfunctions of the opto-couplers relay (OCR) easily, which will lead the HVDC to stop working, an optimized project to the trip circuits of HVDC control and protection is proposed. Firstly, the problems of current trip circuits are analyzed. Secondly, the trip circuits of the AC filters and DC filters are improved, as well as the DC protective trip circuits. Finally, choose other relays with better performance and more reliable to instead of the current ones, and improve the stripping link circuits of the DC filter group. The optimized project was used in the Zhaoqing converter station successfully, which is under good operating condition now.