Applied Mechanics and Materials Vols. 644-650

Abstract: Aimed at the instable pressure of water supply, poor reliability and security problems of the water supply system in high-rise building, this paper adopts frequency conversion and constant pressure water supply technology to design the water supply system with no tower under constant pressure in high-rise building. The water supply system, with PLC as the control center, uses sensor technology and digital PID control to realize constant pressure water supply. Application results show that the water supply system has the characteristics of reliable running, simple operation, saving energy and reducing consumption.

Abstract: This paper presents a RTDS model applied to simulate periodic commutation impulse voltage of HVDC convent valve. The model’s main configure and basic parameters are matching to a typical monopole system which include 12-pulse converters of rectifier and inverter, convert-transformers, DC transmission line, DC filters and AC equivalent power network. Among the system model, the valve components of rectifier are User-Define-Component (UDC) model with RC branch for describing detail valve internal. And also, discrete time step apply 2.5μS non real-time of RTDS for complying with high frequency transient. The validation test is carried out and the result show that the model can simulate accurately valve voltage waveform.

Abstract: A single-element passive quenching with active reset (PQAR) circuit is proposed. Its operation mechanism is studied in theory to show that this single element, based on thyristor, can provide similar function of quenching and reset for the free-running Geiger-mode operation of single photon avalanche diodes (SPADs) as the conventional PQAR circuits, but with significant simplicity. Requirement for the thyristor is identified, and an InP sample was designed, fabricated and characterized. Future work for further demonstration is also discussed.

Abstract: This do In this paper, based on the Wilkinson power divider, a modified Wilkinson power divider using a microstrip in isolation is discussed. It can reduces the size of the circuit board area. What’s more, the isolation bandwidth can be extend by the Wilkinson power divider using a microstrip in isolation. Firstly, this paper illustrates the principles of the traditional Wilkinson power divider. By introducing the concept of isolation network, the real and imaginary part of the traditional Wilkinson power divider are derived. And then, the principle diagram the Wilkinson power divider with RLC isolation network are shown, we also give the expression of the real part and imaginary part of the isolation network. Lastly, we introduce the modified Wilkinson power divider using a microstrip in isolation, and give the expressions of real part and imaginary part of the isolation network, and the above three kinds of real part and imaginary part of Wilkinson power divider are simulated. Through simulation, we found the power divider using a microstrip in isolation has better physical performance.

Abstract: For the need of multi-channel simultaneous sampling in the modeling and identification of power system, a portable data acquisition system is introduced. It can sample multi-channel data simultaneously, and also have a mass data storage. The system is composed of data acquisition card and PC processing software. The C8051F410 MCU is the core of the data acquisition unit card. It not only provides multi-channel synchronous sampling, large storage capacity, easy to carry and low cost, but also can run offline, and bidirectional interaction with PC software. The data processing software is programmed by Visual Basic6.0. Its main function is sending sample orders and the sample data processing. It can store and process the sample data, also it can set the sampling parameters of the card. Through actual verification, the system is easy to use and meets the precision of requirement.

Abstract: In this paper a new type of coolers for electric vehicle on-board chargers is presented, which is based on semiconductor refrigeration technology. Using TEC1-12706 we design a cooler for an on-board charger whose power is 3.3kW. And a thermally driven water cooling system is presented to cool the hot end of the semiconductor chilling plate. Semiconductor chilling plates have the advantages of small size, low weight, dust prevention, seismic resistance, non-noise pollution and non-mechanical wear. So they can obviously improve the performances of the coolers used now. Experiments show that the cooler designed can cool the charger well.

Abstract: This paper firstly establishes a mathematical model of ship power system, and then analyzes the characteristics and common faults of ship power system. D-S evidence theory method is used on research of common faults of the ship power system, to enhance the pertinence of fault diagnosis. By using multi-source information fusion diagnosis, the need for quantities of electrical data is reduced, and, it can effectively reduce the impact of protection or switch malfunction on the fault diagnosis of ship power system and thus improve the accuracy of diagnosis.

Abstract: Universal serial bus is put forward by seven corporations which are led by the Intel. It cost lowly, fast and easily expandable. USB is widely used in serial communication interface, widely used in computer peripherals and digital products. The USB protocol layer is the core unit of the USB device, which handles most of the contents of the USB protocol provides. This paper studies USB protocol layer design and implementation. Then USB protocol layer is completed based on FPGA.

Abstract: Finite element numerical simulation software was used for numerical simulation analysis of cathodic protection of coastal power plant condenser based on physical scale model. The effects of location, size and number of auxiliary anode on the cathodic protection potential distribution of the condenser were studied, which would predict cathodic protection result of the condenser and provide reasonable design for cathodic protection of the condenser.

Abstract: In view of the large cross-section wire overhead transmission lines, Starting from the conductor is flexible, By studying the shortage of the existing equation, The tension of conductor is low level is determined , Under the condition of the conductor is stable, Analyzed the lead in any little effect when the concentrated load lead the actual linear and sag.The analysis of comparing with existing practices.Get a new linear algorithm of computing function when a single concentrated load.After the calculation under the action of concentrated load transmission wire line has a certain reference value.