Advanced Materials Research Vol. 981

Abstract: There are advantages such as real time, quick, multi-constituents simultaneous measurement, green and no pollution, and so on, of using near infrared spectral method to detect concentration information of dairy products constituents. From time domain and frequency domain, near infrared spectral data mining methods based on orthogonality were separately researched to realize noise filtering and useful information extracting. For milk spectrum, methods in the time domain including Orthogonal Signal Correction and Direct Orthogonalization, Wavelet Transform de-noising method in the frequency domain, were separately explored and used in spectral preprocessing, PLS method was used to build calibration model, and processing effect of different data mining methods was compared with and analyzed. It is showed that in the time domain, using the orthogonality methods to make data mining for milk spectrum, the complex interfering signal and noise information uncorrelated with the measured constituents can be can reduced effectively, and the correlated information with the measured constituents is reserved in maximal limitation, prediction capability of calibration model is improved, furthermore, the Orthogonal Signal Correction method is better than the Direct Orthogonalization method, moreover, in the frequency domain, wavelet de-noising is better than the orthogonality methods within the time domain.

Abstract: During quantitative analysis on measured object by using equal precision measurement method, there remains certain difference between the measuring result and truth value due to the impact on measuring method, measuring tools and measuring environment. In order to reduce measurement error, we usually make continuous equal precision measurements on the measured object repeatedly. Then we get the final result by theoretical calculations, error analysis and dispose on measurement data. The data processing shows complicated and error-prone .But now we take computer as a carrier, then combining with virtual instrument technology to accomplish the data-processing system. It can cover the manual computation shortage and can take humanization disposal on measurement data. Moreover, the results can show with multi-mode intuitively.

Abstract: The induced voltage of the long-distance power cable will reach high value, so the metallic sheath of cable should be cross-linked to reduce the induced voltage. It is safe and economic enough but bring out problem of monitoring the situation of insulation. In order to solve the problem, a new method is provied and a monitoring system based on Digital Siganl Processor and Global Positioning System are designed. The composition of system has been introduced, includes the hardware and software design. The results show that the monitoring system can reflect the situation of cable insulation, and the mothod is proved to be validity and feasibility.

Abstract: The prevention and detection of fire have been hotly researched in worldwide. In this paper, an elaborate method of wireless sensor network for building fire safety is proposed. ZigBee technology is adopted in the wireless sensor system to help saving the energy cost and reducing energy consumption. In the routing selection, we choose MESH topology in wireless sensor networks in order to enlarge the monitoring scope. Each end module consists of a microcontroller on Arduino Due board and an Xbee Pro S2 wireless communication module based on the Zigbee standards. Sensors are used for detection which makes it possible to detect fire before inflammation.

Abstract: For the output of wind power system has the characteristics of randomness, volatility and intermittence, the voltage of wind power system low frequency oscillation is one of the most common fluctuations in the system. For the problem of low frequency oscillation, the limitations of the detection methods such as the Lyapunov linearization method, the Prony method, wavelet transform method are summed up, and a new detecting method named Hilbert-huang Transform (HHT) is put forward in this paper, which can detect the oscillation accurately and timely. To solve the problem of end effect in the process of empirical mode decomposition (EMD), B-spline empirical mode decomposition based on support vector machine is applied in dealing with the end issue. an extension of the original signal is applied. Then, calculating the average curve of the signal by B-spline interpolation method. Finally getting the intrinsic mode function (IMF) by empirical mode decomposition (EMD). The practicality of the method is verified by Matlab simulation.

Abstract: CHP system with Energy saving, environmental protection, economic and other characteristics,have good prospects for the development and application value.This paper directe a micro grid system consisted by photovoltaic cells, wind turbines, fuel cells, microturbines, auxiliary boilers, thermal energy storage systems and batteries and heat load and electrical load.Considering various distributed power generation costs, environmental costs and micro-grid equipment maintenance costs,To meet the constraints of micro-grid operation, optimization of the different micro-grid distributed power and energy storage system power output, make the system's total operating costs are minimized.This paper analyzes the economic and environmental of micro-grid optimal operation characteristics, given a model of CHP micro-grid.For the cost of power generation and emissions of different weights, using bacterial foraging optimization(BFO) algorithm,through a numerical example verified the Correctness and effectiveness of mathematical model and optimization algorithm .

Abstract: This paper presents a community-based CHP microgrid model for optimal operation. The model introduces a microgrid controller and consumption parameters, and that the existing restrictions, the optimization of microgrid operation.bacterial foraging optimization(BFO) algorithm was used to develop microgrid problems. Test results show the effectiveness of the model micro-grid operation.

Abstract: Integrated gasification combined cycle (IGCC) is an efficient, low-pollution clean coal power generation technology and efficient use of IGCC technology is helpful to realize clean conversion and comprehensive utilization of coal resources in China. This paper analyzed the factors that influence the power supply efficiency of IGCC power plants, determined assessment model for power supply efficiency of IGCC power plants. Then based on IGCC power plant construction specific data including power supply efficiency, combining the general technical and economic evaluation of the project, the technical and economic evaluation step of IGCC plant was determined. The economic evaluation of IGCC power plant was carried out as well as sensitivity analysis in terms of static total investment, utilization hours and standard coal tax price. The results showed that introduced IGCC of 40 megawatt had higher tariff and utilization hours had maximum impact on tariff.

Abstract: In the paper, power frequency and high-frequency high-voltage pulse breakdown voltage of air-gaps were measured by circuits of spark gap switches respectively, and then output waveforms were obtained by sampling circuits, finally a large number of data in experiments were recorded and were drawn into curves. It can be seen from curves: firstly, relationships between pulse breakdown voltage of air-gaps and pulse delay time or between pulse breakdown voltage of air-gaps and pulse coefficient are discussed when electrodes and distances between electrodes are different, secondly, relationships between pulse breakdown voltage and air-gap distances are analyzed under 100kHz pulse voltage when electrodes are spherical electrodes.

Abstract: Z-source inverter can boost the voltage of the DC-side, allow the two switches of the same leg conducting at the same time and it has some other advantages. The zero-sequence current flows through the fourth leg of the three-phase four-leg inverter so the three-phase four-leg inverter can work with unbalanced load. This paper presents a Z-source three-phase four-leg inverter which combines a Z-source network with three-phase four-leg inverter. The circuit uses simple SPWM modulation technique and the fourth leg uses fully compensated control method. The inverter can maintain a symmetrical output voltage when the proposed scheme under the unbalanced load.