Transformers

1 / 57

# Transformers - PowerPoint PPT Presentation

Transformers. Transformers. The &quot;simple transformer law&quot; 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 &quot;simple transformer law&quot;.

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

## PowerPoint Slideshow about 'Transformers' - astrid

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

### 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.
Neglects

No magnetic hysteresis

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

Part 1
• Measuring parameters of our transformer
1st experiment: VAC

A

Ohm’s law:

V

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

Theory

We will seek the solution of this equations in form:

Dependence M against frequency

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

Diffusion flux

Diffusion flux

Inside flux

Part 2
• Describing all looses in the transformer
Losses

We measured steel losses using the chain (right).

A

V

V

~

Rebuilding a chain

We can rebuild our chain using diffusion inductance

Part 3
• Measuring and modeling hysteresis
Modeling hysteresis loop

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

Changing n
• We are changing numbers of coil turns

A

V

V

~

Resonance mode

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

Conclusions
• 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

Unideal transformer

Resistance of the winding

Losses of the flux

Losses in the core