AC Voltage Stabilization

[pappa_smurf]

Hi all
Here is a good one for all the BRAINY people on this forum.
Is there a simple way ie. connecting ONLY a capacitor across mains that will help to stabilize very short dips.
I ask this because we operate a pressure pump system at the lodge and our power here in Mozambique is very iffy with regular point something second dips.
Being in the middle of Africa I thought I could use a RUN cap from a motor to help.

ANY IDEAS PLEASE
Regards
to all
my email is smithjollyroger@gmail.com

[stj]

Re: AC Voltage Stabilization

no.
there is a technology involving a heavy flywheel you could use.

[Behemot]

Re: AC Voltage Stabilization

Or UPS, line-interactive is minimum and has to be made for inductive loads/motors. But that will be expensive.

[Kiriakos GR]

Re: AC Voltage Stabilization

Hi all
ANY IDEAS PLEASE
Regards

Plenty of ideas if you do not afraid complexity.

http://www.ittsb.eu/forum/index.php?topic=876.0

[999999999]

Re: AC Voltage Stabilization

Get the pump motor manufacturer and model # info and ask the manufacturer what the most cost effective way to manage that is. Possibly you need a different motor or entire pump more immune to the dips.

The flywheel idea is interesting. At first I was thinking an active generator style flywheel but then I thought "What if it's possible to just put it on a pulley or gear on the motor shaft?", although you might then need a second motor to start it so it doesn't burn up the pump motor and then if you're going to do that then you could just select a second motor more immune to the power dips and might not need the flywheel involved at all, just the second motor.

[eccerr0r]

Re: AC Voltage Stabilization

I recall there were some solutions with a variable transformer and a motor controlled by a servo to do regulation a really long time ago... I really wonder how reliable that solution is at the end...

[budm]

Re: AC Voltage Stabilization

http://www.sigmaelectricals.com/autotech.htm
http://www.sigmaelectricals.com/autotech02.htm
https://cdn.badcaps-static.com/pdfs/...bf4c60e62c.pdf
http://voltsmartstabilizers.com/serv...ransformer.htm
http://www.servostabilizer.in/Servo_Stabilizer.html
http://www.ustpower.com/comparing-au...age-regulator/

[Behemot]

Re: AC Voltage Stabilization

I recall there were some solutions with a variable transformer and a motor controlled by a servo to do regulation a really long time ago... I really wonder how reliable that solution is at the end...

And also how (in)efficient.

[momaka]

Re: AC Voltage Stabilization

Possibly you need a different motor...

Good idea.

I'm thinking, maybe find a DC motor that meets the RPM and torque requirements of the original AC motor (or at least I am assuming it's an AC motor). Then it may be possible to build a backup DC supply bank. If the motor is for 12V or 24V DC, the backup DC bank perhaps can be made with car batteries in series/parallel and all hooked to a charger (so that they stay charged when the power is on).

stj's idea sounds reasonable too. Probably the easiest if you have a way to mount something to the motor's shaft. But you'll probably also need a secondary motor for start-up, as 999999999 noted... and a circuit to disengage the main AC motor if the power drops out for too long and the pump stops spinning. Then the circuit would need to engage the start-up motor, get the pump up to speed, disengage the start-up motor and engage the main AC motor again.

I guess none of these are exactly easy solutions.

Is the pump's motor DC or AC? 3-phase or single phase? Induction, synchronous, universal, other?

[budm]

Re: AC Voltage Stabilization

I like the DC motor idea better since you can build good power supply with good hold up and regulation power when voltage sag. When you have power sag, when it recovers, the voltage will over shoot before settling down which is not good for the electronics or the motor either.

[stj]

Re: AC Voltage Stabilization

i suspect this is a water pump that could be drawing from a well.

[ben7]

Re: AC Voltage Stabilization

Assuming the motor is an AC type, you could get a VFD (variable frequency drive) and add a lot of capacitance to the rectified mains in the drive. The drive converts the mains AC to DC, then to AC. Why? It's AC output has a variable frequency, which is used to control the speed of some AC motors. That is not the reason for using that here though. The reason is so that you can put a large capacitance on there to help with the voltage dips.

However, if you do that, beware that the inrush current from the capacitors may cause the rectifier bridge on the mains input to burn out!

[Behemot]

Re: AC Voltage Stabilization

I just by a chance have some older Siemens 3phase frequency drive, 4 kW or 5 HP. I think I can check insides (and caps) without problem and than try it with some motor. If it would be intereseting, I can send it but count on high shipping costs, probably as high as a price of the unit itself. On the other hand, how much would new such unit cost somewhere in Africa? Fortune I bet…

[stj]

Re: AC Voltage Stabilization

the best bet may be an iron or stone flywheel fitted to the pump's motor shaft.