VNU-UET Repository: No conditions. Results ordered -Date Deposited. 2024-03-29T01:26:58ZEPrintshttp://eprints.uet.vnu.edu.vn/images/sitelogo.pnghttps://eprints.uet.vnu.edu.vn/eprints/2019-11-28T01:44:53Z2019-11-29T05:47:30Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/3655This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/36552019-11-28T01:44:53ZA Research on Sensorless Control of Brushless DC Motor using Inductance Variation TechniqueToday, brushless DC motors (BLDCM) have been used in many applications replacing to brushed DC motors. Compared to brushed DC motors, BLDCM offer improved reliability, longer life, smaller size, and lower weight. Besides, BLDCM have become more popular in applications where efficiency is a critical concern and, generally speaking, a BLDCM is considered to be a high-performance motor capable of providing large amounts of torque over a wide speed range.
In this paper, a research on sensorless control method which can drive a BLDCM smoothly from standstill to high speeds without position or speed sensors is carried out. Initial rotor position as well as speed of motor at a low speed range is estimated based on the inductance variation principle while at higher speed, the back EMF technique is applied. This sensorless control algorithm is modeled and simulated with MATLAB/SIMULINK software to verify the abilities of the method. The drive control scheme has been implemented on a single-chip controller (STM32F103) and experimental results reveal that the control procedure can work smoothly.Hai Ninh DangQuang Tan NguyenNgoc Linh Nguyennlnguyen@vnu.edu.vn2016-12-07T08:26:35Z2016-12-07T08:27:20Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2022This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/20222016-12-07T08:26:35ZCharacterization of Electrochromic Properties of Polyaniline Thin Films Electropolymerized in H2SO4 SolutionPolyaniline (PANI) onto indium-doped tin-oxide (ITO)-coated glass samples were prepared by electroopolymerization in 0.5 M H2SO4 solution. Structure and morphology characterization of the PANI films demonstrated that the films were grown onto ITO substrates in the form of polycrystalline microbelts separated by micropores. By analysing the UV-Vis absorption spectra of the PANI films, the energy bandgap was found to be approximately 2.75 eV. The PANI/ITO films exhibited a good reversible electrochromic display (ECD) performance when cycled in 0.1 M LiClO4 + pro-pylene carbonate. The response time of the ECD coloration was found to be as small as 15 s and the coloration efficiency was found to be 8.85 cm2 C-1. After 100 cycles of the ECD performance, the cyclic voltammetry curve of the working electrode maintained unchanged. This demonstrates that the electropolymerized PANI films can be served as a good candidate for ECD applications, taking advantage of their excellent properties in terms of chemical stability.Hai Ninh DangThi Thao Tranthaott@vnu.edu.vnDuy Long PhamNang Dinh Nguyendinhnn@vnu.edu.vn2015-11-19T07:33:37Z2015-11-19T07:34:19Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1258This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12582015-11-19T07:33:37ZCharacterization of Structural and Electrochromic Properties of Nanocomposite TiO2−WO3 FilmsHai Ninh DangThi Thao Tranthaott@vnu.edu.vnNang Dinh Nguyendinhnn@vnu.edu.vnDuy Long Pham