Applied Mechanics and Materials Vols. 543-547

Abstract: On the basis of the second-order upwind scheme, combined with the flux splitting method, we derive a uniform multi-conductor transmission line time-domain calculations. This method is a direct time-domain discrete numerical method with second order accuracy. It does not have any special requirements for circuit and the application process and complex transformations which lead to facilitate the preparation of the program. Numerical experiments show that this method of preparation of general purpose computing program has roughly the same computational efficiency with the traditional leapfrog scheme and at the discontinuous solutions, there are no non-physical oscillations. It can easily be used to calculate a uniform multi-conductor transmission line coupling.

Abstract: Improve power quality problems, the company introduced the "tag through 66kV Static dynamic reactive power compensation device (SVC)", which means water cooling valve parts, using the international advanced technology and light control thyristor, the real control cabinet and valve all-fiber connections between groups, no valve trigger circuit boards, etc., to ensure safe and reliable high-pressure environment. Light control while protecting 66kV more stable water-cooled manifold, also designed the various protection functions. Reactive power compensation device based on electrical design principle, the protection of the valve design principles, summarized the valve characteristic is a light-controlled thyristor trigger and pulse trigger laser fiber distribution device as one of the valve, the valve overcurrent analysis protection, undervoltage protection, return status display, RC protection, BOD protection, protection and cooling system valve structural protection, light control demonstrates the necessity of 66kV water cooling valve protection; through the reactive power compensation and benefits case situation the comparative analysis to verify the correctness of the application of SVC devices.

Abstract: This paper introduced the research status of microgrid control system (MCS) and analyzed the functions of microgrid control center (MCC). A design of multi-functional of microgrid control center was presented, and each relevant functional module was described.

Abstract: As the basis of power distribution network automation, the feeder automation plays an important role in the distribution network. The traditional feeder automation system has a long fault isolation time, the frequent switching and outgoing and then overlap power filter troubleshooting repeatedly. 10 kv feeder automation system in the thesis is controlled by the upper PC computer system and the lower machine system, and the lower machine system's intelligent controller collects the operation information of the voltage and current of the line being monitored in real time with AC-sampling technology, and through the GPRS wireless communication network will field data is passed to the remote control center. When the short circuit faults occur, the controller will immediately disconnect the switch, and the incorrect information will be sent to the remote control center, the remote control center to collect incorrect information from all the controllers, then provide the fault judgment and control strategy through relevant logic. Practices have proved that the system could improve the level and reliability of power distribution network effectively.

Abstract: A design and implementation method of high precision three-phase sine-wave signal generator is proposed based on MCU and FPGA. For the traditional design method, direct analog synthesis method and phase locked loop (PLL) technology are used to design the signal generator. So the function, the precision and other aspects are inadequate. Aiming to the problem, a signal generator is designed based on direct digital frequency synthesis (DDS) technology. The MCU is used to control the peripheral devices and the frequency and phase control word can be obtained. The DDS module is achieved by EP4CE6E22C8 and the waveform lookup table addresses are outputted. The digital three-phase sine-wave data can be read from the lookup table. Through the three-way D/A converter and the amplifier circuit, the digital signal is converted to analog signal and the three-phase sinusoidal wave is outputted. The precision can be improved by increasing the sampling points, phase accumulator bits and D/A bits, and then, high precision three-phase sine-signal can be obtained and the adjustable frequency precision is 0.001.

Abstract: This paper introduced a laboratory management system, fingerprinting to pass the experiment verify the identities and automatically assign the more control over the wireless send instructions to the source control location to make experiments, and arm control unit will regularly monitor the situation in the experiment, on the high security. the intelligent all-weather.

Abstract: This article introduces the alternative principle of progressive characteristic of unbounded Jacobi matrix into the process of automatic control of circuit which makes the feedback signal of control circuit has two different delay characteristics using unbounded Jacobi matrix. It also adds the weight of transconductance unit. The voltage signal can output smoothly which reduces the oscillation of the circuit and improves the accuracy of the circuits automatic control. This paper studies the control role of unbounded Jacobi matrix on the circuit using experimental method and gets the I / V curve. From the curve, we can concludes that the I / V of the circuit is not constant. The boundaries of linear region and the saturation region correspond with unbounded Jacobi matrix theory. Linear and saturation regions have no obviously transition boundary which applies unbounded Jacobi matrix to the automatic process of circuits successfully.

Abstract: In this paper, the use of Lab VIEW virtual instrument development platform, designs the virtual function signal generator based on sound card. The instrument can generate sine wave, square wave, saw tooth wave, triangle wave, gauss white noise, superposition of sine wave, custom formula waveform, it can be arbitrarily set parameter as frequency, amplitude, phase, the noise standard deviation, it has simple operation, good interaction, it save the cost and can be widely used in scientific research and experiment teaching.

Abstract: It is very important to study the emission of pollutant from a coal combustion device, and it is a best way to adopt numerical simulation for such a study. By using a mathematical model with a post-processing method and based on combustion simulation, this paper calculates the SOx distribution in a power plant boiler furnace. For the formation of SOx, a conventional chemical reaction model is adopted, and according to the principles of reaction dynamics, a model for the SOx formation is also put forward. It is the first time for preceding the calculation and on-site testing an 800MW-unit boiler in China. The test and calculation results show that the model is reasonable, and such a study will be valuable as a reference to the boiler design and its clean operation.

Abstract: This first step of ageing management in nuclear power plant is to determine the objectives and their priorities. The characteristics of the objectives are complex and highly nonlinear coupling. A fuzzy logic based screening and grading method have been developed in this research for the first time which combined the genetic ageing lessons learned and field expert experience to resolve the problem. The method have been approved of highly applicability and applied to ageing management in multiple nuclear power plants.