Advanced Materials Research Vol. 676

Abstract: Study the mechanical and electrical system,according to the mechanical system of the coupling mechanics principle, the AC drive system is simplified as many degrees of freedom "spring - mass - damper" system,the quality of construction of three two-axis system,established the two shafts electromechanical coupling vibration mathematical model; Using the electromechanical coupling vibration simulation model, the parameters of the current regulator, damping, harmonic disturbances, gap and load disturbance of electromechanical coupling factors such as vibrations caused by dynamic process.Improve the dynamic performance of the system is significant, have the great value for the parameters of the system design and fault diagnosis on this study.

Abstract: The advanced material has been used extensively in various engineering in recent years, especially in the fuel-gas pipes. The material properties are always under the influence of a variety of factors, such as different levels of the manufacturers, the manufacturing process and so on. Although many countries have strict supervision to the material properties of fuel-gas pipes, but the pipe leak is inevitable. So the leak detection has important meaning in the field test experiment of pipes’ material properties and the practical engineering. In order to solve the problem of interaction between the fuel-gas pipe leak detector and the users, a man-machine interface is designed based on electrical power system. The hardware mainly consists of the microprocessor, the input circuit and the output circuit. The software of interface is realized with the embedded C language, and it mainly consists of the input program and the output program. Experiment results show that the man-machine interface can accomplish the interaction between the user and the detector for advanced material with material properties in fuel-gas pipe splendidly; and it has a good application prospect.

Abstract: This paper proposes a novel modeling method for permanent magnet synchronous motor (PMSM) system in electrical automation engineering based on adaptive network based fuzzy inference system (ANFIS). Meanwhile the microhabitat particle swarm optimization (MPSO) was used for training the parameters of ANFIS. The proposed modeling method for PMSM system can help in speed and position control. The proposed ANFIS and MPSO based modeling method has been successfully applied to PMSM control system.

Abstract: Electric power distribution systems play an important role in electric power systems, in which automation intelligent distribution terminal units are critical for the performance of power distribution systems. The software of an automation intelligent electric power distribution terminal unit based on digital signal processor is designed in the paper, a way of admixture programming with C language and assembly language. In this manner, real-time requirement on the electric power distribution system will be satisfied, the reliability and stability of the software are ensured as while. It has a broad application prospects in electric power systems.

Abstract: The detection and fault identification of the partial discharge is the important aspect for the monitoring of the power equipment. For the lacks of the traditional detection methods, this paper analyzed the UHF signal characteristic parameters of the power equipment’s partial discharge, and developed the UHF detection system of the partial discharge. The A/D technology of the gain equalization and quantization in the different bands is studied, and the fault diagnosis strategy of the partial discharge based on the UHF and AE is proposed. On the premise to ensure the integrity of the partial discharge signals, the acquisition, amplification, analysis and storage of the partial discharge signal is realized. The case-based reasoning technology determines the fault type and fault degree of the partial discharge to make the accurate judgment for the operational state of the equipment and improve the intelligence level and the operational reliability for the state diagnosis of the power equipment.

Abstract: Metal oxide arresters (MOA) are important apparatus defending electric power systems against lightning strikes. The resistive current value of MOAs can reflect equipment status better. In conventional methods measuring resistive current of MOAs, wires need to be connected to the secondary side of voltage transformer during each test, and this brings great safety risks. A new wireless method is proposed to measure resistive current of MOAs. Based on GPS and wireless transmission module, wireless synchronous measurement of portable current detector and voltage monitor can be implemented. Fourier Sequence algorithm is applied to detect the resistive current of MOA. System compositions, design and methods of hardware implementation is focused on in this paper. Lab experiment and on-site testing results show that the method is satisfactory.

Abstract: Accidents of icing on catenary have great impacts on normal operation of trains. An on-line anti-icing technology used static var generator (SVG) for catenary was proposed, which can prevent icing formation without interrupting trains normal operation. The heat balance equations for catenary were solved, whose results were compared with data provided by TB/T 3111 and testing show the equation was correct. The simulation model based on Matlab was bulit , whose results and analysis show the correctness of the method.

Abstract: A theoretical model is developed to investigate sound transmission characteristics of an infinite lightweight plate line connected to equally spaced stiffeners and excited by an oblique plane wave. The reactive forces and moments at the line connections are obtained from the flexural and torsional motions of the stiffeners. The vibro-acoustic equation that describes the dynamic response of the structure is derived by employing the Fourier Transform method, which will be numerically solved by truncating the solution to converge. Numerical examples are presented to investigate the effects of the incidence angle, the stiffener spacing, the plate thickness, on the sound transmission characteristic of the system, and useful conclusions are drawn.

Abstract: Photovoltaic array output characteristics under partial shading conditions have multi local maximum power points, but traditional maximum power point tracking methods failed to identify global maximum power point. Output characteristics of shadowed PV array under different illumination were simulated by Matlab software. The rule between voltage of possible local maximum power point and the open circuit voltage was summarized. According to this rule, a modified algorithm based on the Incremental Conductance method was put forward. Simulations results indicated that the proposed MPPT algorithm can accurately track the global maximum power point under uniform illumination and partial shading conditions. It can improve the efficiency of PV system.