any recommended brand of power supply for testing AVR function? 1

[cloonypan]

Hello,

I would like to test a AVR performace of a permanant magnetic generator. The inputs signals supplied by gernerator to AVR are two phase 80VAC and 320Hz. To find out the low frequency protection knee point, I need a programmable AC power supply to replace the two phase signals which supplied by generator. The power supply should capable to simulate 0~80VAC and 0~320Hz. In other words, I want to change the V/F ratio by power supply to test the AVR. Is there any recommended instrument could do this test? Thank you.

 

[ScottyUK]

Pacific Power Source make some really nice programmable AC power supplies. You probably want to rent one rather than buy it.


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If we learn from our mistakes I'm getting a great education!

 

[cloonypan]

Thanks Sotty

 

[cloonypan]

Thanks Scotty

 

[ScottyUK]

One thing to consider is your bottom frequency limit: 0Hz is DC - do you really need a supply which can work all the way down to a few millihertz and / or DC?


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If we learn from our mistakes I'm getting a great education!

 

[cloonypan]

Thank for reminding that.
I was thinking this question. When the generator speed is zero, the voltage is zero and also frequency is zero. By this condition, I think the power supply should be capHable output low frequency signals. However, after survey some AC power supplies such as Kikusui and Pacific Power,some products of them can only supply frequency above 45Hz to several hundreds hertz. Working from zero hertz are rare.

Consider the function we want to test is the Knee point of AVR, maybe the frequencies lower than ten to twenty is no need.

 

[ScottyUK]

Well, what happens to the PMG output when it is stationary? I expect it is zero, so you don't need to worry about DC.

At some point the AVR will stop working as the supply collapses, and from a practical point of view most generators are off the system by 45Hz because the prime mover won't tolerate operation that low so it may not be of anything but academic interest what happens below 45Hz.

Depending on how low in frequency you need to go and how much power you need, you could use a signal generator with an audio amp connected to a step-up transformer on the output, or a really big audio amp which won't need a transformer: some of the kW+ amps can produce 110V AC output and have a full-power bandwidth down to 1Hz.


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If we learn from our mistakes I'm getting a great education!

 

[waross]

A PMG AVR is a common option on diesel powered sets.
On these AVRs you test the under frequency protection by varying the frequency of the sense voltage, typically 50Hz or 60 Hz. V/Hz protection should be active below about 47 Hz or 57 Hz respectively.
Is this the type of generator you have?

Bill
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Jimmy Carter