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ASSER
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Join Date: Oct 2013
Posts: 72

MVAR Effect

03/10/2014 1:08 PM

Dear all

What is the effect of the increase in the( MVAR ) on the transformer

Thanks
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wareagle
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#1

Re: MVAR Effect

03/10/2014 3:24 PM

An increased load on the transformer. Maybe your question refers to the power factor

or something else. Does it?
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ASSER
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#2
In reply to #1

Re: MVAR Effect

03/10/2014 5:16 PM

Dear sir

thank you for response

I mean if the power transformer operation with low power factor (for examlpe 0.4 PF)

are this effect on transformer

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PWSlack
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United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

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#3
In reply to #2

Re: MVAR Effect

03/10/2014 6:55 PM

It may hum more.

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TonyS
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#6
In reply to #3

Re: MVAR Effect

03/10/2014 11:19 PM

No, they only hum when their happy. Unhappy they rattle.

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RAMConsult
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#4

Re: MVAR Effect

03/10/2014 10:26 PM

It's effect is simple, it is the I²R heating of the copper that rules, the transformer will overheat if it is forced to supply more than its rated MVA. Transformers are limited by the magnitude of the current they carry, and they are largely indifferent as to whether it is all reactive current in the form of MVAR, all real current in the form of MW, or any combination in between those extremes. It is always MVA = (MW² + MVAR²)½

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Apol
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Join Date: Dec 2013
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#5
In reply to #4

Re: MVAR Effect

03/10/2014 10:44 PM

MVAR - this is the rated capacity of your transformer.
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RAMConsult
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#7
In reply to #5

Re: MVAR Effect

03/10/2014 11:54 PM

No, High Voltage Power transformers are rated in MVA, kVA, apparent power; not kW, MW, kVARs, MVARs, real power, reactive power.

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dhayanandhan
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#8

Re: MVAR Effect

03/11/2014 11:15 AM

Dear Mr.ASSER,

The Power Factor will fall.

The winding Temp. will increase. Hence Transformer oil temp. (If oil cooled Transformer)will go up and more cooling fans will get switched on.

Transformer will trip on account of High Temp.

DHAYANANDHAN.S
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Apol
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Posts: 10
#9

Re: MVAR Effect

03/12/2014 12:35 PM

transformer to be over heat.

You adjust the MVAR output of the machine by adjusting the exciter of the machine. That is to raise MVAR output you excite the machine more by increasing the current in the field (rotor). This increases the magnetic coupling of the rotor to the stator and increases the MVAR output.
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Users who posted comments:

Apol (2); ASSER (1); dhayanandhan (1); PWSlack (1); RAMConsult (2); TonyS (1); wareagle (1)

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