phase sequence in a double feed asyncronous generator

[181273]

hello to all the eng tips people, here´s Jose from Spain looking for some help... and with the worst english of the net... I´m sorry.
Ok, the question is I got a double feed asyncronous generator from a wind farm, the power is 2,2 MW, and the guys I sent to dismount it, had disconnected the cables that coming from the rotor wind, and now I don´t know the phase sequence of this cables....
I´ll like to know if I connect a positive sequence... in example, R to terminal U, S to terminal V and T to terminal T, I´ll get the rotation in the way the generator is done to rotate... but for me the question is: with this sequence... I have to get the same sequence in the output of the rotor??
thanks as always in advantage

 

[waross]

In a wind turbine that motors the generator to start the blades, you may be able to just energize. If the blades start in the wrong direction, stop immediately and change connections.
There are some machines that for mechanical reasons are prohibited from reverse torque.
However in a wind turbine that must be motored to start, the machinery must be able to accept torque in either dirrection.
respectfully

 

[181273]

no,no the generator is only used as generator... it´s rotor is feeded from a inversor that put the current needed for start generation and when you go up over sincronism speed it start to take the rotor current, rectify and then back to the grid....

I need to put the terminals and the sequence for the right operation of the electronics... I think the sequence will be the same as the stator....

take care

 

[alwale]

hi i a new member and i just wonderd about the reason to why the exiter cureent is DC and not AC i mean can we make the exiter cureent AC

thank you

 

[Skogsgurra]

Hi alwale. Would that help the OP?

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[181273]

hi everybody, I think all of you didn´t understand the thread... this is a motor with the next:
- three phase wind on the rotor.
- three phase wind on the stator.
- 1 encoder on the shaft.

The way we use to work with it on the wind farms, is the next:
- First moment to start to generate, you need the power of the wind to get the mechanical power.
- Then, the system cheek the speed
- And feed the rotor with a current with the sequence of the grid, the value of the amps that go inside depends on the speed... more amps, means more flux and finally more volts... The frequency of this current depends on the speed and the number of poles... in this way, the voltage induced on the stator is on 50 hz and the net voltage.
- At this moment we are ready to couple to the grid.
- Depending on the mechanical power we could get more or less output power.
- After the rotor rise the syncronism speed, the rotor stop taking power from the grid, and start to produce power, but this power is not at grid frequency... for this we need to rectify it and then use a three phase inversor to convert the dc current into ac current with the frequency of the grid...

my question was if the sense of rotation on the voltage of rotor and stator are of the same sense, I think it´s true it´s the same sense of rotation.

sorry for my badly english...