You Jiaxin

The Effect of Coil on Combined Three-Subsection Permanent Magnet in Close Magnetic Circuit Model

Working characteristic of the permanent magnet (PM) is a key point of PM relays design. Soft magnetic material and coil will effect the working characteristic of PM. In order to analyze the effect of coil, a combined three-subsection PM in close magnetic circuit model (CTPMC) is built based on the equivalent magnetic circuit, and its theoretical model is established under the magnetic potential effect. Through the theoretical deduction, it is concluded that each PM subsection works at different recoil lines and the working points would change due to the effect of coil. Finally, the above theoretical analysis results are validated by simulation and experiments.

Research on the dynamic calculation model for a dc solenoid electromagnetic contactor and its contact characteristics in break process

DC solenoid electromagnetic contactor is widely used in electrical vehicles, airplanes, trains and other 270v high voltage DC power supply system. Due to its special working environment, the limitation of the volume and weight of the contactor is strict. This requires the contactor to have excellent shock absorption and breaking capacity. The static electromagnetic calculation model of one type of solenoid contactor is established using the finite element method (FEM). Then the dynamic numerical calculation model of the contact and spring system is established and further combined with the solenoid dynamic electromagnetic characteristics. The Runge-Kutta method is adopted to solve the dynamic differential equations, and the dynamic calculation results are compared with the test data. The validity of the model is verified. Using this model, the dynamic characteristics of the electromagnetic mechanism under different spring parameters are analyzed.

Research on the calculation methods of enclosed isolated phase bus-bar in short-circuit condition

The enclosed isolated phase bus-bar (EIPB), which is the first power transmission part of synchronous generator output, plays an important role in the stability of the system in short circuit conditions. The section shape of bus-bar has very big relation with the dynamic stability of EIPB. In this paper, an analytical calculation model of EIPB is analyzed firstly. Based on the analytical model, the finite element method (FEM) and its model is established. The traditional rectangle bus-bar and circle bus-bar are calculated using this model. The performances under different conditions are discussed: with enclosures and without enclosures, AC. Taking the circle section EIPB for example, the relationship between the ratio of transfer current and the electrodynamic force safety are also discussed.

Novel Design and Research for a High-retaining-force, Bi-directional, Electromagnetic Valve Actuator with Double-layer Permanent Magnets

To increase the retaining force, a novel design for a concentric, bi-directional, electromagnetic valve actuator that contains double-layer permanent magnets is presented in this paper. To analyze the retaining-force change caused by the magnets, an equivalent magnetic circuit (EMC) model is established, while the EMC circuit of a double-layer permanent-magnet valve actuator (DLMVA) is also designed. Based on a 3D finite element method (FEM), the calculation model is built for the optimization of the key DLMVA parameters, and the valve-actuator optimization results are adopted for the improvement of the DLMVA design. A prototype actuator is manufactured, and the corresponding test results show that the actuator satisfies the requirements of a high retaining force under a volume limitation; furthermore, the design of the permanent magnets in the DLMVA allow for the attainment of both a high initial output force and a retaining force of more than 100 N.