Advanced Materials Research Vols. 383-390

Abstract: The numerical calculation model with compound insulation of transient electrical field is established. The types of voltage applied on the valve side winding of the converter transformer are complicated and the insulation is more prominent. So the simplied calculation model of the valve side winding of the converter transformer is established. The distribution characteristics of electrical field of the valve side winding of the converter transformer is analyzed and electric field in different electrical conductivity and permittivity are calculated under AC high voltage, DC high voltage, AC superimposed DC voltage, polarity reversal voltage. Under all kinds of high voltages, the maximum electric field strength is calculated and analyzed. Some important influence factors for electrical field distribution are also discussed in this paper.

Abstract: The paper mainly discusses how to calculate composition error of low-voltage metering device. The composition error of metering device, the error of power meter and the ratio error of CT were calculated also by comparing the standard power meter with the calibrated power meter .The formula of error calculation was put forward, that will has an important guiding significance for the development of on-site calibrating instrument

Abstract: Torque ripple reduction of the brushless DC motor has been the main issue of the servo drives in which the speed fluctuation and the vibration should be minimized. Un-ideal back EMF (electromagnetic force) usually induces distinct torque ripple. A full EMF feedback strategy is presented in order to effectively reduce torque ripple. The relationship between the terminal voltage of auxiliary winding and the back EMF of brushless DC motor are investigated, and the back EMF can be measured on-line by using the auxiliary winding, the q-axis current for a constant torque to produce is calculated through coordinate transformation when d-axis current is zero, and the reference q-axis current is adjusted in real time by vector control in dq0 coordinate. The simulation results show that the proposed strategy can effectively minimize the torque ripple.

Abstract: This paper, innovative approaches are based on laser scanning and image analysis, presents an efficient composite technique for object profile extraction with real-time image processing. High throughput is obtained by algorithmic prefiltering to restrict the image area, while high accuracy is achieved by neural recontruction of the profile.

Abstract: In the past half century, the camera industry has developed very rapidly, which drove the optical lens and optical zoom technology to make great progress. The zoom lens’ technology principle of current mainstream optical zoom lens system is achieved by adjusting the relative position of the lens, objects and the focus. This paper takes the double-liquid zoom lens based on electric wet effect as the basis , the new zoom optical system is designed to achieve motor control without mechanical movement, then the vision correction is designed by using liquid lens, such as the correction of myopia and hyperopia, which can automatically identify the eyes degrees of myopia and hyperopia, avoid frequent replacement lens steps when optometry is done for eyes.

Abstract: For improving launching velocity and efficiency of intercepting plate in active electromagnetic armor protective system, theoretically analyzing the main parameters that determine the change of electromagnetic force. Investigating the system dynamic changes in different pulsed power equipment driving manners. Combining different driving manners, the dynamic working process of the intercepting plate launcher are simulated, that adopting finite element analytic software Ansoft’s transient solution to simulate the dynamic process of intercepting plate. The maximum velocities obtained in the bipolar driving manner and in the single-polar driving manner are 12.61 m/s and 14.00 m/s respectively. Analysis shows that the effect of the electromagnetic force is not only related with the driving manners but also with the materials.

Abstract: Currently, the most widely used method to calculate boiler efficiency is based on wet basis oxygen which is measured by online instrument, rather than on dry oxygen. Consequently, it often results in the deviation of calculation results, as well as bad adaptability to different kinds of coal. In this study, an online calculation method of boiler efficiency as deducted based on the wet oxygen, and validated by typical soft coal and lignite. It is revealed that the results of this calculation model is more close to that of standard calculation method by elementary analysis. Moreover, the online calculation method can exhibit a better performance of coal adaption, which can be used as a method to guide for the better optimization of utility boiler combustion.

Abstract: A new method that uses the same clock signal between the frequency test system and the I/F converter is provided to avoid the frequency test error. The standard instruments such as FLUKE 5520A calibration and FLUKE 8508A 8½precision multimeter are used, that not only simplifies the design of the test system but also enhance reliability of the system. The RS232 bus and the GPIB bus are used to achieve the automatic test.

Abstract: The metering and controlling of down hole flow has became an important and indispensable technology in the development of oil field as well as the intelligent oilfield technology, the correlative data which measured by them can provide a reliable theoretical basis for the production and management of the oil-field. Develops a new flow measurement device which can adapt to the complex down hole environment is very important. This paper emphasis on the composition of the data acquisition system about flow test in the down hole, including the design of data acquisition system, the application of bus, the selected of core chip and the design of software, and super-induce some collecting data that get in the test, determining the most value information, as well as making a more rapid response to the oil deposit management, gets up a significant guiding sense to the heavy oil development and the intelligent well completion.

Abstract: In order to seek methods of reducing the coolant resistance of radiators in mini-vehicle, the resistance distribution in minicar radiators was obtained by carrying out numerical simulation to coolant flow field of the radiators. The analysis indicated that the coolant resistance mainly composed of two parts: the resistance along radiating pipes, the inlet and outlet resistance of the water tank. Reducing the surface roughness of coolant pipes could lower the resistance along pipes. Slowing down the changes of the inlet and outlet section could reduce the local resistance.