Lecture for Physics and EEE

The assignment is done for my loving friends, best wishers and all of the AUST students: Practice Exercise 13.1: Practice Exercise 13.2: Practice Exercise 13.3:   Problem 13.1: Problem 13.2 Problem 13.3 with the best wishes By_ Md. Monzurul Islam ( Raton) web: www.monzu.webs.com

Thesis And Project On the Topics of  Star Delta Conversion Motor And its development Group Member: 01. Md. Monzurul Islam 02. Sheikh Satil Harun 03. Jannatul fedous Shila 04. Rezwana Mahboob Bonna 05. Upoma and 06. Tarin Supervised By_ Golam Mostafa Associate Professor Department of EEE Ahsanullah University of Science & Technology  Introduction:   Star Delta Conversion Motor is a such type of Induction motor which can run in star and delta connection also. Here it is remembered to memories that this two connection it operates differently. In Star Connection: it takes high current and gives low speed.  In Delta connection: it takes low voltage but gives high speed. following figure is a star delta conversion 3 phase Motor:                      1st Day:                  ...

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We Know Single Phase Induction Motor is not Self started. But we can overcome it by converting  it into two phase induction motor. For this phenomena The Stator of a single phase motor is provided with an extra Winding, known as Starting Winding. Which is added with its main or running  winding. This two winding are spaced 90 degree  with each other and connected in parallel across the single phase supply. Which is shown in following figure: So that the phase difference between the currents in two stator winding is very large, then this motor behaves as a two phase induction motor.So then we get a resultant flux which made a starting  torque and our motor is rotateting

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Three-phase transformer circuits Since three-phase is used so often for power distribution systems, it makes sense that we would need three-phase transformers to be able to step voltages up or down. This is only partially true, as regular single-phase transformers can be ganged together to transform power between two three-phase systems in a variety of configurations, eliminating the requirement for a special three-phase transformer . However, special three-phase transformers are built for those tasks, and are able to perform with less material requirement, less size, and less weight than their modular counterparts. A three-phase transformer is made of three sets of primary and secondary windings, each set wound around one leg of an iron core assembly. Essentially it looks like three single-phase transformers sharing a joined core as in Figure below . Three phase transformer core has three sets of windings. Those sets of primary and secondary windings will be connected ...