Novel Two-Stage High-Power-Factor Electronic Ballast CHUN YUAN CHRISTIAN UNIVERSITY

Abstract

In this thesis, electronic ballast with power factor correction for high intensity discharging (HID) lamp is presented. The proposed topology is a two-stages circuit that requires only one switch and one inductor for each stage. Power factor correction (PFC) stage is boost dc-to-dc converter operating in continuous conduction mode (CCM) to achieve low total harmonic distortion (THD) and proper output characteristics over a wide range of load (10% ~ 90% full load).
This control implementation for against broken lamp can be easily implemented with the proposed circuitry. The high-frequency supply the lamp is given by the flyback converter. Input AC voltages ranges from 90V~260V are allowable for our system with a low DC bus voltage below 450V. It is suitable for electronic ballast with medium power HID lamp. The topologies could work under the circumstance of two 250W fluorescent lamps at 66 KHz switching frequency.
LINK
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A STUDY OF CHARGING EQUALIZATION AND DISCHARGING POWER MANAGEMENT FOR SERIES AND PARALLEL CONNECTED BATTERY PACK

A STUDY OF CHARGING EQUALIZATION
AND DISCHARGING POWER MANAGEMENT FOR SERIES AND
PARALLEL CONNECTED BATTERY PACK

研 究 生： 蔡志明    Jr-Ming Tsai
指導教授： 李清元教授    Prof. Ching-Yuan Lee

Master Thesis Department of Electrical Engineering Tatung University

ABSTRACT
ABSTRACT

The object of this paper is to research the methodology of charging equalization and
discharging power management of the series and paralleled connected battery sets under the
considerations of the safety, economics and practicality to improve the overall battery sets
efficiency.  The battery management system used the isolation method to ensure the charging
equalization of batteries; and to protect from the abnormal situation during discharging of the
series-connected battery sets.  As for the parallel-connected battery sets, this paper proposes
a multi-mode chopper.  It will enable to control and distribute the output current from each
battery.
The serial and parallel connection scheme uses two batteries as the smallest unit.  The number of batteries may be expanded at will.  The system performs the charging and discharging tests of the serial and parallel connected GS LC18650 1800mAh lithium battery sets.  Finally, a single-chip microprocessor, PIC16F877 is use to implement the control method of the proposed system. Via the experimentation, it proofs that the methods can performs its feasibility and good characteristics as anticipated.

LINK FULL THESIS
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Enterprise-Scale UPS Protection for Medium and Large Data Centers

Inside our ups's manufacturing

Resoluções de Provas - ITA - ITA 2012 - Matemática - (Parte 1 de 3)