Applied Mechanics and Materials Vols. 241-244

Abstract: An AC -DC converter with power factor correction (PFC) function is proposed in this paper. In the proposed converter, the boost PFC stage and the active-clamp DC-DC converter stage are merged into a single converter to reduce the overall cost and improve the power density. An active-clamp DC-DC converter stage can suppress the switch voltage stresses and provide zero-voltage-switching (ZVS) operation of the switches. The boost converter in PFC stage operates in discontinuous conduction mode (DCM) and it provides naturally high power factor. Due to the ZVS operation, the switching losses of the proposed converter are significantly reduced and the efficiency is improved. Steady-state analysis is performed. Simulation results are also provided to verify the effectiveness of the proposed converter.

Abstract: A novel low-cost shunt hybrid active power filter for power quality in high voltage system is proposed in the paper. The active power filter is based on three-phase four-switch structure. An inductor is parallel in the second-side of the transform, instead of connected in the first-side of transform. An improved SVPWM is proposed according to the APF structure. A novel coordinate matrix is proposed to transform three-phase circumrotating coordinate into two-phase static coordinate. The zero vector is composed of two space voltage vectors with same breadth and contrary direction at same working time in a switch period. Simulation results confirm the validity of the proposed structure and the improved SVPWM.

Abstract: Nowadays, State Grid Corporation is promoting the construction of the “Large Five” system and new requirements for the management of are put forward. A brief analysis of the current power transmission and transformation equipment management and their existing problems is given in this paper. Based on the analysis, the Power transmission and transformation equipment life cycle management framework is proposed. The framework is composed of management support systems, including asset management standard system, key index evaluation system, assets benefit evaluation decision mechanism when put into operation, the life cycle assets management information system, and decision-making method with the cost benefit mechanism and key index evaluation mechanism. At the same time, with the use of risk assessment, assets life-cycle cost management, state evaluation, reliability evaluation, life evaluation, the transmission and transformation equipment assets management level is optimized.

Abstract: It takes a long time to replenish energy for electric-bus by charging, while battery swap is an effective way with fast energy supplement ability. The process of electric-bus battery swap is complex, how to realize automatic, efficient and reliable battery swap is an urgent problem to be solved. This paper analyzed the electric-bus battery swap system, and then constructed the control model of battery swap according to state machine theory, finally developed a battery swap control system based on Quantum Platform framework. The battery swap control system has been applied to many electric-bus battery swap stations; it improves the station’s efficiency and reliability greatly, and provides a guarantee for the popularization and application of electric-bus.

Abstract: Using AMESim to build a three-way catalytic converter （TWC） physical model to study the light off characteristics, through numerical solution of the energy and mass conservation quations of gas-solid two phase. This paper obtains the emissions conversion rate curve, such as CO, unburned hydrocarbons (CaHb) and nitrogen oxides (NOx) under different parameters. The results show that, the engine control strategy, allocation of TWC and it’s structure are all the TWC light off characteristics effects, which provids the theory basis for the TWC designers.

Abstract: A certain type of airborne photoelectric equipment is the key device for aiming and distance measuring. On the basis of analyzing the test requirement of the equipment, a test system is designed with PC104 embedded computer as the core control system. The function of the test system is suggested. Hardware programs of power, bus board, signal conditioning circuit and anti-jamming measure are designed. The multithreading technology and measures to prevent wrong data communicating are applied to develop software of the test system. The test system can be applied to test and debug the photoelectric equipment. The data handling technology used in the test equipment has advantages as high speed, high efficiency and high reliability.

Abstract: Digital instrument transformer calibrator is the key equipment which is applied to calibrate instrument transformers automatically. The instrument transformer based on principle of high potential difference measurement is suitable for calibration of voltage instrument transformer with high voltage and high accuracy, as it avoids being affected by additive error. This paper presents a plan for high precise instrument transformer calibrator based on principle of high potential difference measurement. On the basis of this design scheme, the technology of shielded input-signal wire, input-signal isolated amplification and shielded circuit is adopted to design the instrument transformer calibrator. The produced calibrator is able to fulfill the requirement of self-calibration of power voltage ratio standard due to its excellent performance with high accuracy and stability.

Abstract: With the development of science and technology, high-powered equipments are increasing demanded in various industrial fields. It is no doubt that higher requirements for power inverter control technology is required. In this paper, on the base of traditional PID control strategy, duo to its paraments can’t self-turning, this disadvantage makes it difficult to achieve the best control effect, proposed a fuzzy self-adaptiving PID control technology. By means of MATLAB/Simulink module to realize the inverter achieves good dynamic and static performance.

Abstract: To study the clinical application of high performance liquid chromatography（HPLC)、Radioimmunodetection and Automatic biochemical Analyzer on the detection of plasma total homocysteine(tHcy)、folic acid（FA）、VitB12、Triglyceride（TG）、total cholesterol(Ch)、high density lipoprotein cholesferol(HDL-C)、low density lipoprotein cholestorol(LDL-C).Clarify the mecanism of plasma total homocysteine(tHcy) inducing central retinal artery occlusion(CRAO) Methods We measure the level of plasma tHcy、 folic acid、 VitB12、 blood sugar、 blood pressure and blood lipid by the instrumentations above.Results:The level of plasma tHcy in CRAO group increase while the level of plasma folic acid reduce.Conclusions:We discovered biomarkers of CRAO.HPLC、Radioimmunodetection and Automatic biochemical Analyzer can be used well for the detection of the biochemistry markers above.The value of plasma tHcy can damage capillary blood vessel endotheliocyte and give an impetus to CRAO.HPLC maybe an optimal method for the clinical screening of CRAO.

Abstract: In order to meet the needs of speed measurement for rotation system, a rotation sensor which based on the principle of Anisotropic Magnetoresistive Effect was designed in this paper. This paper presents the principle, detailed hardware circuit, frequency characteristics of the sensor, as well as the valid detection distance. The sensor used MR elements as the sensing element. It turned the change of the magnetic gear’s rotation speed into the change of the circuit’s output signal and ultimately achieved contactless rotation measurement of the magnetic gear. The hardware circuit of the sensor includes five parts: signal collection, impedance matching, signal amplification, digitalization processing and signal output. The tests show that its operating frequency ranges from 2 Hz to 6 KHz.