Applied Mechanics and Materials Vols. 701-702

Abstract: jumper has been weakness of protection of windage yaw flashover in Grid, timely and effective identification method of windage yaw flashover is lacked in the existing power system; focusing on the point that less jumper windage yaw flashover, the phenomenon of jumper windage yaw flashover is explored, by checking windage yaw angle and the minimum air space under strong wind, to confirm the possibility of jumper windage yaw flashover caused by strong wind; by mining the law of the jumper windage yaw flashover, and applying the fractal theory calculation, the electromagnetic transient characteristics of transient current travelling waves is studied, to propose a jumper windage yaw fault identification method based on the similarity of transient current travelling waves, which is successfully applied to Hainan Power Grid’s Fuguan line jumper windage yaw flashover in 2011.

Abstract: Based upon the designed cylinder type structure of electromagnetic linear actuator for vehicle active suspension, the drive circuit of the tubular electromagnetic linear actuator and the dead zone unit were designed. By the AutoBox dSPACE control system and the intelligent power module IPM, the main power circuit was built up, and the simple test platform was also built up. Through the test platform, the square wave force and triangle wave force experiments were tested. Through the test, it shows that the drive circuit design of the electromagnetic actuator is feasible.

Abstract: In this paper, a multi-purpose alarm system for dormitory based on control conducted by AVR single-chip microcomputer is designed and produced, which aims at potential safety risks existing in dormitories of colleges and universities at present. This system uses multiple sensors to realize detection of human body, smoke, access of people and valuables, after which signal will be processed and AVR single-chip microcomputer will then be used to realize automatic control. Host computer receives information from slave computer and then realize long-distance and real-time monitoring. Test result indicates that this system functions well and can realize security of student dormitories if applied, which can raise audible and visual alarm in case of abnormal situation and realize cancel of alarm through entering password on a keyboard.

Abstract: This paper presents an experimental study of an electric bicycle. We operated the bicycle on flat roads, uphill and downhill. The speed was categorized into slow, normal, and fast. Electrical loads were varied, step by step, for example 180, 240, 300, and 360 W. According to the observations of electrical power produced by an electric bicycle, we found that at the load of 240 W, it can produce a maximum power of 91.56 W. However, the generator can produce a maximum power of 350 W; therefore, we used a load of 360 W for studying and modeling. Finally, this model can be used to predict the electrical generation from electric bicycles as well as used for meter monitoring.

Abstract: Eight channel wireless intelligent responder has been designed based on 51 SCM, and the button switch and the microcontroller I/O are used as the input and output, the digital tube and the I/O are used as display function. The software is programmed with C language, which is simple and easy to understand and very intuitive, at the same time, the whole design is simple and practical. After testing, the system can realize the eight channel responder function and can be conveniently applied to the game.

Abstract: Controlling the output current characteristic of the pulsed power system is the important approach to optimize the parameters and to heighten the system efficiency in the Electromagnetic Launching System. For enhancing the system performance, distributed-current-feed style is introduced. A distributed current feeding-in model is established and the characteristic and performance is analyzed. Stimulation depicts:1)adopting the distributed feeding style results in more efficient than the central feeding style ;2)employing the new method of distributed-feed-timing-discharging goes a step further to heighten the muzzle velocity. The new model is meaningful to optimize the structure of the electromagnetic launching system, and is effective to the design of the launcher and current-feeding-in system.

Abstract: With the sub-module number and scale growing on, the whole control system of MMC (Modular Multilevel Converter) tends to be much more complicated because of the cascade structure, which also intensifies the pressure of the converter main controller. To distribute the converter main controller’s task, the design of sub-module tenders itself extremely important. However, there is no explicit and comprehensive study on how to design the sub-module. This study, according to the characters of MMC, introduces a feasible architecture of hardware and software for the sub-module with optical communication. Each sub-module has its own independent controller and control system. That is to say, every sub-module is a complete system, which can do calculation and communication with outside. Sub-modules connect with the main controller of converter through communication using optical fibers. By adopting the optical communication, sub-modules not only can receive the control references data from the main controller, but also can send its own condition information back, which creates an interactive communication between the two sides. Additionally, through detailed experiments, the validity and feasibility of the design are demonstrated under two different control strategies.

Abstract: Three heat exchangers, all of which have 38 tubes in total and 6 passes, with different tube arrangements were manufactured to be experimental investigated in laboratory. The effect of flat tube distribution on heat transfer performance and pressure drop characteristic was experimental investigated. The effect of different air velocity and flow on heat transfer performance and pressure drop characteristic was also experimental investigated. The results show that similar tube distribution has little effect on heat transfer quality but has great effect on pressure drop. It was found the third arrangement has the best heat transfer and its pressure drop is small. Thus the third arrangement is the best solution. The heat transfer and pressure drop increase with the air velocity and refrigerant flow, so a proper value should be chosen, it was found that the simulation results were mainly agreement with the experimental results.

Abstract: Because of the flexibility and clear physical concept, magnetic circuit calculation method (MCCM) is preferred during the early stage of the electromagnetic design of generators and motors. Based on the analysis of magnetic field distribution in halbach magnetized permanent magnet generator (HMPMG) by finite element method (FEM), this paper proposes a distributed magnetic circuit calculation (DMCC) for HMPMG. Because of the low permeability of permanent magnet (PM) material, the DMCC for HMPMG is quite different from that for electrical excitation generator. By dividing half-pole generator model into sub-sections along radial and circumferential direction with circumferential equi-interval nodes in air gap, the DMCC for HMPMG employs iteration to calculate magnetic flux density on air gap nodes. In the end, the validity and accuracy of DMCC are proved by FEM.

Abstract: To make a building structure beautiful and obtain a good daylighting, the windows become more and more big. It is inconvenience for the opening and closing of the bigger curtain. The frame structure of automatic control curtain is designed and manufactured, as well as DC motor drive, light detection, preventing over-wind, curtain position detection circuit. The corresponding control programs realize the automatic control function of curtain. Automatic curtain system contains three kinds of mode. Manual mode is the basic function of automatic curtain system. The wireless remote control function provides convenience for the user to control the opening and closing of curtain. Automatic light sensor model realizes the automatic control of curtain, according to the brightness of the light. The sensitivity of light sensor can be adjusted by artificial to make the customer satisfied. The open degree of curtain can be manual adjusted to meet the requirements of the various length of the curtain. The system is simple and practical. Its energy consumption and cost is low. As a part of the smart home, the system is suitable for opening and closing control of the curtains and provides the convenience for people's daily lives.