Advanced Materials Research Vol. 823

Abstract: In order to optimize design parameters of Power Source, an approach to selecting MOSFET and Filter and isolation techniques to improve system interference immunity is proposed. The parameter selections of MOSFET, capacitance and inductance have a certain impact on the property, volume and the cost of the system. The design of a three phase power source based on FPGA device is set as an example, its focus on the theory analysis, calculation and design of MOSFET, filter and the circuit of drive isolation and the analysis of selecting SPWM carrier frequency and power conversion efficiency. Finally, the experimental results and waveforms are presented.

Abstract: High-rise buildings in the city center construction has been with diversify disposition. As there is high wind on top of high-rise buildings, wind turbines are often installs on top of high-rise buildings. However, we can expect efficient power generation only by installing when the turbine in the place of heavy wind. In this article, it tries to evaluate wind power generation by performing airflow analysis around the roof according to the disposition of high-rise buildings.

Abstract: It is urgent to study a new control system for improving the efficiency of electrostatic precipitator. The System-on-a-Programmable-Chip (SOPC) development board, which belongs to the series of Cyclone of Altera Company, is used as the development platform. Analog Digital (AD) conversion module, voltage control module and overall control module of the electrostatic precipitator are designed and the simulation waveform of the system is analyzed, based on the programmable logic device EP1C12Q240C6 and Very-High-Speed Integrated Circuit Hardware Description Language (VHDL) programming language. The results show that: by using Field Programmable Gate Array (FPGA) as the control, transformation of AD is accurate and fast and high voltage power supply is stable, which leads to a certain value for generalization.

Abstract: AC signal sampling technology is the basis of measure and control for electric power system and motor. A hardware synchronous AC signal sampling board is designed for an embedded SCADA system based on LPC2138 and ADS8365. The design principle and implementation methods of the hardware and software of the board are introduced in this paper. As parts of an eSCADA system, the modules have been brought into use at power plants and power control centers since 2012. The result of experiment and industry application shows that the sampling accuracy and real-time performance meet the requirements of relevant standards, and these boards work stably and reliably.

Abstract: In order to achieve the GIS fault detection and defect type recognition, four typical defect models were designed and discharge tests are carried out aiming at insulation defect as well as discharge characteristics in the GIS .With a large number of ultra high frequency envelope signal ,a method of domain feature extraction was proposed based on wavelet packet transform with singular value decomposition .The envelope signal was decomposed through wavelet packet transform first in the method, then the coefficient matrix of wavelet packet transform was built in the scale ,after that feature vectors of matrix were extracted by means of singular value decomposition. On this basis, BP neural network was took advantage of for pattern recognition .The results show that the good recognition effect was obtained with that method . Keyword: Ultra high frequency; Envelope signal; Wavelet packet transform; Singular value decomposition; BP neural network

Abstract: The purpose of the present work is to present a overall design of digital AC servo system, which is based on PMSM on the background of Self-propelled Artillery servo system. A magnetic field Orienting control tactic based on vector control technology is explored. DSP CMOS chip TMS320F2812 is adopted as a control core to design total-digital AC servo system. Since the work current of the servo system is high, the MOSFET component is used to construct the power inverter circuit, rendering the high current controllable. The simulation results prove that the system has good dynamic performance.

Abstract: Nowadays, an increasing number of grid is adopting resonant grounding method. Only accurately detecting the capacitive current, could we play the advantages of resonant grounding. The most popular method in the field is the tuning method, which includes two-point method and three-point method. This paper analyzes the principle of two-point method and identifies a major problem in the application of two-point method. A stall of two-point method stays in the state of overcompensation while another stall stays in the state of under compensation, which has not been taken into account. Finally, the paper verifies the effect of proposed improvements using MATLAB simulation.

Abstract: Intermittent and volatility of wind energy makes wind power generation output power characterized by its instability make adverse impact on grid power quality , will give a rise to serious problems of voltage fluctuation and flicker. It is very important to calculate the flicker emission when analysis the power quality. However, flicker level is hard to predict and the way given by IEC61400-21 has been verified to be lack of accuracy. This paper analyzes a constant speed wind turbines caused grid voltage fluctuation and flicker on the mechanism. Illustrates the two way to measure flickers caused by voltage fluctuation. Improves the on-site calculation of flicker by considering the impact of tower shadow and wind shear. Finally, verified the feasibility of the improved methodology by comparing the results of the three calculation.

Abstract: In order to improve the level of automation and realize remote control of the transformer temperature control system, a fast remote automatic control system that based on the chip TMS320C6713 was designed by us. Using four temperature sensors (Pt100) tow amplifier and analogy to digital (A/D) convertor detect deal with the signal of the temperature of winding and environmental. According with the temperature of transformer to control the cooling device switch on or off, the service life of the radiator was extended. In the design the digital signal processor (DSP) chip is communication with the central control room through the RS-485 bus, which makes the remote transformer temperature monitor into reality. In addition, this system is more versatility and reliability than the traditional device.

Abstract: Satellites solar array provides sustainable and reliable energy for satellite by changing the solar energy into electrical energy in order to ensure the normal working of the satellite. The working status of solar array is directly related to the satellites normal running in orbit. The thesis summarized the normal trend of the GEO satellites solar array output power, through comparing the real output power of a certain satellites solar array with the normal trend, and detected four abnormal phenomena of solar array output power. Then the thesis analyzed the reasons, and made related suggestions.