Dynamometers

Jul 01, 2014 71 Replies

In a DC system, 4 quadrant is often, (ok, usually) but not always, regenerative. Not usually on an AC supply system.

4 quadrant symple means it can controll both accelleration and decelleration in both directions - hense - 4 quadrant. Dynamic braking in a 4 quadrant AC control generally sinks (dissipates) the decelleration power, while regenerative braking in a 4 quadrant DC system generally returns the braking energy to the source.

Just my experience. 2 quadrant control can also be either regenerative or dynamic.

Please show me a circuit for 4 quadrant control of a DC motor from an AC supply that implements true regenerative braking. Explain how the output of the DC motor is syncronized to the ac line frequency. Then give me the name and manufacturer of the contoller, with specs on the amount of current it is capable of returning to the grid, and I'll believe you.

I am fully aware of DC regenerative 2 and 4 quadrant motor controls, and I know how an induction motor can be used as a generator, but I'd really like to know how to recover the power from my DC motor to the AC grid. (not just recover it into a battery)

That has some merit, but you will be required to utility mains interactive inverter and a bidirectional Watt Hour meter.

?-)

That has some merit, but you will be required to utility mains interactive inverter and a bidirectional Watt Hour meter.

?-) ================== We just got remote-reading electric meters. If installed upside-down they continue to read demand correctly and set one of the bits in the tampering word, unlike old electromechanical meters that run backwards if inverted. They appear to defeat "Net Metering" with grid-tie inverters.

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The three-dot pattern represents the spinning disk. The pattern changes for every Watt-hour consumed.

-jsw

No, you can buy a DC motor controller that includes the two thyristor bridges for full 4-quadrant operation.

I'm dense? Take a look at you, "Big Jamie", KA1LPA:

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I think you're that person on the right.

Which does NOT put power back to the grid

Thank you. :)

Jamie

No comment.

Jamie

You are one hard-headed PITA. Get some balls and call the manufacturer of the controls to which I provided a link in this thread. Ask them. If you do not want to educate yourself, then you are a waste of air.

Chew on this, hard-head...

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"Braking

Does the application require the drive to provide braking torque? If so, how much and how often? Even a little braking torque can be an issue if it is continuous. It adds up.

DC drives can easily pump braking energy back to the AC mains. In fact the cost for full regeneration is so reasonable that Nidec-Avtron offers regenerative braking bridges for free up to about 300HP. Above that, non-regenerative DC bridges are available and cost less than their AC drive counterparts. Alternatively, dynamic braking can be provided by adding an external DB contactor and DB resistors. The advantage goes to DC. "

If you think this is helping your case, you are dumber than a fence post. Call the manufacturer to which I referred in my earlier post. Unless you don't want to know that you are wrong.

Oh. Got egg on your face now, eh?

I'm interested. Please resend the manufacturer's name and the actual model number of the control you referenced. I will contact them. IF I'm wrong, I'll admit it right here. Never seen one that worked that way - but that doesn't mean it's impossible.

My reader has tossed the previous messages so I cannot easilly go back and retrieve the data.

Thanks

Contacting the manufacturer would be an embarrassment on said subject.

That drive you pointed to is junk to start with, low end, drop it in the basket when it hiccups.

You don't get it. You are the one being thick headed.

Jamie

How bout you calling them, I could go for a laugh!

Jamie

Not only that, you can't interpret the meanings of half the s*it said here, no wonder you are confused

Jamie

I did. They confirmed exactly what I said. The drive returns energy to the AC line.

Yes, you would be embarrassed by their reply.

Like you would know? I will be sure to forward this to them to see what they think of you impugning their product in public.

The phrase "Being ignorant is not so bad as being unwilling to learn" fits you to a tee.

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