Transformers
Download
1 / 57

Transformers - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

Transformers. Transformers. The "simple transformer law" relates output voltage to input voltage and turns ratio. Investigate the importance of frequency and other parameters in determining the non-ideal behaviour of transformers. The "simple transformer law".

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Transformers' - astrid


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Transformers1
Transformers

  • The "simple transformer law" relates output voltage to input voltage and turns ratio. Investigate the importance of frequency and other parameters in determining the non-ideal behaviour of transformers.



Using the Kirchhoff's andFaraday’s laws


Neglects
Neglects

No magnetic hysteresis

We also need to separate running with load and free running, as it’s particular case.


Dependence of coefficient against frequency (with load)


Dependence of coefficient against frequency free running
Dependence of coefficient against frequency (free running)


Dependence of coefficient against voltage
Dependence of coefficient against voltage


Dependence of coefficient against resistance
Dependence ofcoefficient against resistance


Part 1
Part 1

  • Measuring parameters of our transformer


1 st experiment vac
1st experiment: VAC

A

Ohm’s law:

V

We used small DC voltages to measure the resistance of the winding


Plot vac 1 st winding
Plot VAC, 1st winding


Plot vac 2 nd winding
Plot VAC, 2nd winding


Theory
Theory

We will seek the solution of this equations in form:








Dependence m against frequency
Dependence M against frequency

M(mutual inductance factor) depends on frequency because of depending µ on it



Diffusion flux
Diffusion flux dependence

Diffusion flux

Inside flux



Without core
Without core dependence


Rotation
Rotation dependence



Linearization1
Linearization dependence


Part 2
Part 2 dependence

  • Describing all looses in the transformer


Losses
Losses dependence

We measured steel losses using the chain (right).

A

V

V

~



Dependence of full losses in the 1st winding against voltage
Dependence of dependencefull losses in the 1st winding against voltage


Dependence of temperature losses in the 1st winding against voltage
Dependence of dependencetemperature losses in the 1st winding against voltage


Dependence of steel losses against voltage
Dependence of dependencesteel losses against voltage


Dependence of dependencediffusionfluxagainst voltage


Rebuilding a chain
Rebuilding a chain dependence

We can rebuild our chain using diffusion inductance



Demonstration f erromagnet ic
Demonstration dependence. Ferromagnetic


Part 3
Part 3 dependence

  • Measuring and modeling hysteresis


Hysteresis
Hysteresis dependence


Changing u 0
Changing U dependence0


Modeling hysteresis loop
Modeling hysteresis loop dependence

If we know all the coefficients, we can have as a result of our model real hysteresis loop



Changing w
Changing w dependence


Changing n
Changing n dependence

  • We are changing numbers of coil turns

A

V

V

~


Dependence of coefficient against number of turns
Dependence of dependencecoefficient against number of turns


Theory1
Theory dependence


Resonance mode
Resonance mode dependence

We can imagine a real winding as system of coils, resistances and capacitors.


Conclusions
Conclusions dependence

  • Transformer coefficient depends on

    • frequency because of the resistances of windings and the dependence of induction on frequency

    • the load because of the resistance of the 2nd winding

    • input voltage because of hysteresis mode

    • turns number of the windings because of dependence M on it




Dependence of dependencesteel losses in the 2nd winding of voltage


Dependence of dependence coefficient against frequency (with load)



Unideal transformer dependence

Resistance of the winding

Losses of the flux

Losses in the core


ad