How Do Regenerative Drive Units Work?
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- Опубліковано 30 лип 2024
- Engineers and building owners looking for ways to improve performance and lower cost should understand how regen drives work. In this lightboard lesson we talk about how Regenerative drives can return energy to the building power supply. A line regen unit takes energy typically lost through a braking resistor and puts that energy back on the grid, making the regenerative system more environmentally friendly and saving money.
#RegenDrives #Regen #VariableFrequencyDrives
Regen Drives explained:
* www.kebamerica.com/blog/vfd-r...
Get info about KEB Regen Drives:
* www.kebamerica.com/products/r...
Learn about Brake Chopper Circuits:
* kebamerica.com/blog/brake-cho...
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Love this tutorial format!
This was very informative, thank you.
Really well done! Helpful, thank you
Thanks, and very nice explaining, but i want to know if i connect power source by generator how save power ( generator not damage), and could you please explain the signal or wave shape from generator to Motor and Virs via.
Straight forward, thanks
I guess that is all you need to do for an induction motor with AC mains, but bldc regen is somewhat a different beast. There needs to be some sort of boost, buck boost or cuk circuit involved to get the back voltage up to the level required for the battery to charge it. I am hoping i can apply a high frequency chopper timing to my half bridge since the motor coil is an inductor already. and perhaps a smoothing or storage capacitor which then makes it a cuk circuit.
Thanks dude
A question was asked, "Do they need to be listed to ul1741?"
The UL 1741 requirements depend on device’s application and usage at the end product. At this time, the KEB R6 unit (Regen drive) is strictly designed as an industrial regen device. It cannot be used in a Grid Tie application. Therefore UL 1741 does not apply. It is classified as power conversion equipment according to UL 508C and the CSA standard.
how low voltage flowing to high voltage during regenerating braking....?
Thx Doctor 🤍✨
Love your videos. Thanks for the explanation!
How do the igbts on the input stage know when to switch? I imagine the drive compares the actual dc bus voltage to the AC input... when dc bus voltage goes over what rectified 480 would be, then dump it back on the line. Very curious. Thanks!
Thanks for your question and your compliment. IGBTs are amazing pieces of technology. This website gives a little more info on how they work. www.vfds.org/insulated-gate-bipolar-transistor-887962.html
thanks
You're welcome!
Hi, i have same case in our VSD...if any spike voltage the vsd trigger to trip, suspect indication vsd trip is over voltage from source power (generator)...my question can be the brake resistor handle our problems (over voltage from source power generator ) ?
Thanks for the question. A braking resistor can help prevent over voltage errors. However, the voltage spikes would still need to be addressed because you risk damaging the drive. A braking resistor would be addressing the symptom but not the cause of the issue. It's always best to have a quality source of incoming power to your application.
mantap pakdhe👍
Hi . Can you exlplain me how just by replacing the diode, you can sure that the igbt can be a power regen unit . As far as i know diode block the flow regen . But im not sure why the igbts can flow it . Please anw anybody
Hello, Thank you for the question. You are correct. Diodes allow for one directional flow. So power can only go into the unit. IGBTs are a switching supply so it can output towards the main line similar to how it outputs towards the motor.
Sorry i have some questions:
Does it have any problem if using the regen mode with the source which is powered by diesel generator set?
What happen if the regen power exceeded the need of others device, then will the vfd automatically changeover to the braking resistor mode?
Thanks for your question. If you want to know more about a specific regen application like the one you explained, please contact a local KEB representative near you. If you are in North America you can contact us here: www.kebamerica.com/contact/
The one thing I want to know is, why and how does the bus get stepped up to 620vdc on line regen units? As a test and repair engineer I'm dying to figure this out!
I don't have a simple answer for your question. You can research the reason for this and post it. Thank you for your comment!
@@KEBAmerica I'd be quite happy with a complex answer. I'm perfectly familiar with KEB VFDs to component level and repair blown firing stages frequently. But I have not yet been able to figure out the answer to the questions I posed.
I see. Glad to know you're familiar with KEB VFDs. I'll ask around and see if any other engineers here know why/how our regen bus gets stepped up to 620VDC.
@@KEBAmerica Thank you, I appreciate your efforts to get an answer. ☺️
Here's the best general answer I can find for you:
"The DC 600 V is also coming from rectified AC source. but it is controlled DC output.
There are 2 types of power supplies in 611 system
Uncontrolled PS DC output is 1.35x Vac input (V)--call UE module
For instance, 10/25KW UE module, input 480VAC ==1.35x480=648 VDC--DC bus
E/R ps, or you called regen. should be extactly 600VDC (+/-1%) , when all enables applied and module function is good."
Great videos! I want to purchase a regen drive and build a dynamometer :)
Thanks for your comment, Jeffrey. If you would like to purchase a regen drive you will want to go through a local distributor. Message us or find a distributor here: www.kebamerica.com/contact
What about the short circuit conditions... It will contribute a huge fault level...
Are you asking if adding the regen makes for a larger potential fault? Can you explain your question a little more? Have you experienced short circuit faults with Regen units? We do supply fuses. You can read more about short circuit current ratings here: www.kebamerica.com/blog/short-circuit-current-rating-sccr-and-fuse-selection/
Basically input diode replaced by igbt so it can work as inverter ckt during regenerative braking
Ok... that's a simple explanation, tip of the iceberg :) But I must say it's not entirely true. Even without regen you can still fairly efficiently use 4 quadrants of drives. It wasn't uncommon to have drive units connected through DC line and with capacitor bank attached just for internal regen of decelerating/reversing motors. Unless DC line voltage crossed safety threshold (in which case braking resistor sunk excessive energy) such system might have been quite efficient as well. Why are there regen systems? That's fairly simple. Most regen systems have constant DC voltage. e.g. 600V. Unloaded, lightly loaded, heavy loaded... always around that value. If current feeds back they return it to the power lines. Drives works with constant DC supply so doesn't have to adjust. Common DC bus systems with no regen = if one drive decelerates rapidly and DC voltage rises all other drives have to adjust PWM to maintain setpoint. Obviously it's not particularly good design but works ok on smaller scale. Fun fact - polish trolleybus in Tychy used similar approach as they have fairly new fleet with ASIM or BLDC while their power grid was still designed for DC motors with speed control through serially attached resistors (so basically no regen at all, just a lot of energy wasting). In that case if there was one trolleybus slowing down and at the same section other one accelerating the first would transfer excess energy to the section line which would power the second trolley. If there was no other trolley it would still brake with resistor (so generate wasteful heat) or mechanical brakes (the same).
Do you have some more resources on that subject.
I have a question in response to this... Why do line regen drives step up rectified mains to 600/620vdc? And how does it step it up?
@@SimplyElectronicsOfficial Usually they use a converter model called Buck & Boost Converter to match the power rating with the battery, for efficient charging. The converter model steps up/down as required.
Please make video of difference between AFE and regenerative unit
That's a good idea. We will consider doing a video or blog article on this topic. Thank you for watching!
Are you actually writing backwards?
Haha! No, Mike is writing normally. We just flip the video horizontally. (Now you know our secrets)
@@KEBAmerica THANK YOU, I can finally watch the video without being distracted trying to figure it out !
Yaaru Saamii ivan