Papers by Keyword: Magnetic Field Distribution

Abstract: Launcher is widely used in rescue and delivering items. On the basis of the electromagnetic theory, magnetic suspension principle and linear motor theory, we put forward the idea of magnetic suspension launcher. Through the theoretical research and simulation analysis, an in- depth study is also given to the distribution of the electromagnetic field and other influential factors concerning the propelling system, which provides the basis for the design of magnetic suspension launcher.

Abstract: This research proposes a new parallel-type short-circuit current limit adjustment device. A unified power quality control strategy is provided to solve the typical issues of the power system. Meantime，when short-circuit fault occurs in the load side，short-circuit current can be limited to minimal range. The parallel-type short-circuit current limit adjustment device simulation model is established based on PSCAD/EMTDC simulation software. By doing some experiments on the parallel short-circuit current limit adjustment device, the correctness and validity of the proposed main circuit topology and control strategy is validated.

Abstract: Magnetic controllable reactor (MCR) has many advantages in reactive power compensation in high voltage system, but the power loss and temperature rise problems limit its working capacity and impact its advantages. To improve its performance, a more accurate quantitative analysis about the condition of power loss and temperature rise in MCR is needed. This article uses ANSYS software to build a 3-dimensional simulation model about a dry-type MCR. The model analyses its magnetic field distribution, power loss and temperature rise. The silulation results is proved by experiment. This research provides an effective method and a theoretical basis to design the new structure of MCR and considerably reduces the design cycle and the cost.

Abstract: Dry-type transformer is a high electric strength, high mechanical strength and high heat intensity transformer. With the acceleration of our city and countryside grid construction and the energy saving requirement in power industry, the application of dry-type transformer is expanding. Also, society proposes a higher standard in dry-type transformer. To improve its working capacity and reduce power loss further, we need to analyses its inner working conditions. This thesis uses finite element software ANSYS to build a model of dry-type transformer and gets its power loss and temperature distribution under different working capacity. After comparing this simulation results with experimental results, the accuracy of simulation method is proved. This simulation provides a structure optimization method of dry-type transformer. It can reduce design cycle and cost, help to spread the application of dry-type transformer.

Abstract: Magnetic sensor with direction memory can be used to control the motion direction. Based on Biot-Savart theory, the magnetic field distribution expression of a bar-type in external space is derived, and the superposition distribution of both inner and outer magnet is directed by the principle of superposition, which can be used to quantitatively describe the magnetic distribution formed by inner and outer magnet, and accurately scope the effective field. According to the operating characteristics of the magnetic reed switch with different value of pull-in and drop-out, by a proper detecting distance to ensure the magnetic field strength value of inner magnet at magnetic reed switch greater than pull-in value and less than drop-out value to make magnetic reed switch maintaining the original state when outer magnet leaving. Meanwhile, by a proper detecting distance to ensure the superinposed magnetic field strength value greater than pull-in value in the forward direction, and less than drop-out value in backward direction. Calculation of response curves show the impacts of magnet size, response intensity and detecting distance variation on the sensor.

Abstract: A novel design of micro-hotplate is proposed for micro-structural gas sensor. The simulation results of ANSYS reveal that higher temperature and more uniform temperature distribution was achieved in the micro-hotplate when the thickness of SiO₂, thickness of Si substrate, electrode width and electrode space were designed to be 100, 200, 20 and 230 μm, respectively. The new micro-hotplate is benefit for the improvement of sensor sensitivity.

Abstract: e. The formalism of wireless power transmission is discussed coupled mode theory can be used to describe the resonance process. According to the changing process of input impedance and input current to describe the demarcate of resonant frequency. also demonstrate that loop circuits have an important effect of the resonant magnetic field distribution.

Abstract: The paper presents a novel Si-substrated micro-hotplate for gas sensor. Use platinum filament as heater, SiO₂ as thermal and electricity insulation. Through optimizing analysis, in order to make the gas sensor obtain perfect properties of higher temperature and uniform temperature distribution, the thickness of SiO₂, thickness of Si substrate, electrode width and electrode space are designed to be 50, 250, 20 and 500 μm, respectively. Via the analysis of magnetic field distribution of the new gas sensor, the new electrode structure can eliminate the interference on the measurement signal from magnetic field, which is benefit for the improvement of sensor performance.

Abstract: A novel electrode structure is designed. Through the analysis of the temperature distribution of the gas sensor, the micro-structure gas sensor owns the best temperature distribution when the heating width, measuring electrode width and electrode space are designed to be 50, 20 and 500 μm, respectively. Through the simulation of the magnetic field, the new electrode can eliminate the interference from magnetic field on the measurement signal, which is beneficial to improve the sensor performance.

Abstract: Electro-thermal analysis of a new micro-hotplate designed for gas sensor has been studied in this paper. Through the comparison of materials, select pt as electrodes material, Si, SiO₂ as substrate materials. Then, through the optimization of substrate structure, in order to make the gas sensor obtain perfect properties of good temperature uniformity, the thickness of Si substrate, thermal insulation layers are 150, 50, 100 µm respectively. The new micro-hotplate structure is benefit for the improvement of sensitivity and overall performance of the sensor.