Liu Zhi-ming

The analytical calculation of the thrust and normal force and force analyses for linear induction motor

Linear induction motor has been applied to magnetic suspension maglev and metro vehicle. Its thrust and normal force analyses are important basis of motor design and control. The longitudinal end effects have strong influence to performance of linear induction motor, we consider this influence through equivalent EMF. Aiming to the conductivity of secondary and ferromagnetic secondary, transverse edge effects are considered by different modified coefficients. After got modified coefficients, we can compute thrust and consider end effects. Normal force is computed by one-dimensional analysis and two-dimensional LIM model with multi-layer secondary. Finally, we got the thrust and normal force by a model of a single-sided linear induction motor under different air gap and current frequency. The results are then applied to the single-sided LIMpsilas, and its performances are predicted. Results from analyses are compared with those obtained from tests.

Fabrication of Optical Fiber Bragg Grating Assisted Mismatched Coupler

We report the fabrication of an optical fiber Bragg grating assisted mismatched coupler based on the fused biconical tapered technology. The investigation of the spectrum properties shows that the coupler has a good filtering property. The drop filtering efficiency as much as 94.2% at 1553.5 nm is achieved. Furthermore, using the fabricated coupler, a wavelength de-multiplexing transmission experiment is carried out in a 10 Gbps system with NRZ optical signals. Experimental results show that the coupler basically realizes the function of wavelength de-multiplexing.