arthurgeorge
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HI goodafternoon
trust ur day is fine
so you mean 3x 15kva 3phase cant run the 20kw induction motor?
Can a victron 3-phase inverter setup power a 20 horsepower 15 kVA induction motor..
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trust ur day is fine
so you mean 3x 15kva 3phase cant run the 20kw induction motor?
arthurgeorge
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arthurgeorge
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hi, good afternoon I appreciate ur wonderful effort on this I haven't been on this part that was why i swung into research on this system.. i simply want the best idea bro.. regarding ur idea can 15kva victron x 3 in 3phase handle that motor?
A 10 HP motor is 7.5 kVA. Victron inverters can typically handle a short term surge of 200% which is 30kVA. It sounds like the system should work.
If you really want things to work, then I suggest you consider adding a variable frequency drive. These are motor controllers that start motors more gradually and prevent the big turn on surge. They are also protective of gears (if the motor is driving a gear box). Nice thing is they give you speed control which is often helpful.
Something like this.
These will also convert single phase to 3 phase as well. Which means you could get by with a single 10 kVA Quattro unless you need 3 phase power for some other reason.
Victron Energy Quattro 10,000 Watt 48 Volt Inverter & 140 Amp Battery Charger 230 VAC
Part Number: QUA481030010 Note: To do advanced Inverter configuration and setup you must have a VE.Bus To USB MK3-USB Interface. These single phase inverters can be programmed to output 240V 60Hz for North American applications. Couple with an Autotransformer to do neutral forming for 120/240V...
www.solar-electric.com
- Edit -
My bad you are looking for 20 HP (which is 15 KVA). Not sure where I got 10 HP from (haven't had my coffee yet).
In that case you will need a 20 HP VFD and a 15 KVA Quattro.
20hp vfd | 20 horsepower variable frequency drive
20hp VFDs for Any Application Available. Authorized Distributor of Top Brands. Get Free Shipping on $100+ Orders!
www.wolfautomation.com
Victron Energy Quattro 15,000 Watt 48 Volt Inverter & 200 Amp Battery Charger 230 VAC
Part Number: QUA483150000 Note: To do advanced Inverter configuration and setup you must have a VE.Bus To USB MK3-USB Interface. These single phase inverters can be programmed to output 240V 60Hz for North American applications. Couple with an Autotransformer to do neutral forming for 120/240V...
www.solar-electric.com
Last edited:
Hedges
I See Electromagnetic Fields!
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I'm sure it could run it. 3 x 15 kVA = 45 kVa, sufficient for 20 kW even if "apparent power" volts x amps is well above actual power watts.
What I don't know is if it can provide enough current for starting surge.
I've measured single phase induction motors, and saw they drew 5x their nameplate current for about 1/6 of one second. (using an oscilloscope and current probe.) Running with moderate load, current draw was 1/2 nameplate current.
I haven't done the same with 3-phase. It is possible they don't draw 5x because 3-phase provides better torque for starting. You have to find what instantaneous peak current they draw. This may be given as "locked rotor amps", and there may be a standard multiple assumed if "locked rotor amps" isn't quoted.
If your equipment loads the motor from a standstill, starting would be more difficult, excess current draw could last longer. Some loads like air compressor have an unloader; pressure on output of pump is released to allow easier starting. Air conditioners should stay off for a period of time to allow pressure to bleed off before restarting.
For single or split phase induction motors, we look for an inverter capable of 5x nameplate current. For instance, Sunny Island can put out 11 kW for 5 seconds, sufficient to start and then run a 2 kW motor. Sunny Island is rated 6 kW.
If you use a variable speed motor drive "VFD", that can ramp motor RPM up slowly over several seconds. In that case, no current surge.
Hedges
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Only six hundred bucks.
Wish we could feed these directly from PV (too wide a voltage range), or battery.
230 Vrms is 325V peak (not quite a 400V battery)
Suitable MPPT PV charge controller and series string of batteries.
Or even PWM charge controller; would be simple and low cost if available
arthurgeorge
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thanks for the help i have started developing a system design hoping it works...A 10 HP motor is 7.5 kVA. Victron inverters can typically handle a short term surge of 200% which is 30kVA. It sounds like the system should work.
If you really want things to work, then I suggest you consider adding a variable frequency drive. These are motor controllers that start motors more gradually and prevent the big turn on surge. They are also protective of gears (if the motor is driving a gear box). Nice thing is they give you speed control which is often helpful.
Something like this.
These will also convert single phase to 3 phase as well. Which means you could get by with a single 10 kVA Quattro unless you need 3 phase power for some other reason.
Victron Energy Quattro 10,000 Watt 48 Volt Inverter & 140 Amp Battery Charger 230 VAC
Part Number: QUA481030010 Note: To do advanced Inverter configuration and setup you must have a VE.Bus To USB MK3-USB Interface. These single phase inverters can be programmed to output 240V 60Hz for North American applications. Couple with an Autotransformer to do neutral forming for 120/240V...
- Edit -
My bad you are looking for 20 HP (which is 15 KVA). Not sure where I got 10 HP from (haven't had my coffee yet).
In that case you will need a 20 HP VFD and a 15 KVA Quattro.
20hp vfd | 20 horsepower variable frequency drive
20hp VFDs for Any Application Available. Authorized Distributor of Top Brands. Get Free Shipping on $100+ Orders!
Victron Energy Quattro 15,000 Watt 48 Volt Inverter & 200 Amp Battery Charger 230 VAC
Part Number: QUA483150000 Note: To do advanced Inverter configuration and setup you must have a VE.Bus To USB MK3-USB Interface. These single phase inverters can be programmed to output 240V 60Hz for North American applications. Couple with an Autotransformer to do neutral forming for 120/240V...
quattro15kva x 3 connected in 3phase 45kva because not only is the 20hp machine the load I use on my farm. i have another load too but the 20hp is the highest rated load among others...
I hope you can see me through this project because you have helped me a lot with the information you give. if it was you bro what kind of battery are you going to use for this system assuming you are powering a 30kw load for 24hours what's gonna be your ideal design thanks.
arthurgeorge
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thanks a lot for your ideas and the information you gave.. I have got one fact straight: I need a VFD or soft starter to operate this load on the inverter my fear was I doubted the inverter to power and run an induction motor.. but you guys a saying is 100% possible with inverters... please do you have any link or video I can check to see where it was done and the motor ran successfully with the inverter
arthurgeorge
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ok the nameplate current is 30.7A should I say I have to times this by 5?, what if i deploy your idea of VFD or soft starter do i still need my system to be x 5 the surge? i think i read the Quattro 15kva can withstand 50A surge to 100%, is it right to say the 15kva x 3 quattro in 3phase has a 150A surge?
Hedges
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For single phase, multiply by 5. I've measured it for a small motor.
Yours is 3-phase, may be much less than five. You need to research what starting current is for those larger 3-phase motors.
I think with VFD it will be only 1x, not 5x.
We may use soft starters for single phase, not sure that is applicable to 3-phase.
Yes, whatever wattage the Quattro can put out in surge wattage, you will get 3x that in a 3-phase configuration.
"powering a 30kw load for 24hours"
Do you need to power the loads 24 hours a day, not just during daylight?
In that case you need a battery able to supply the power for 12 or more hours.
It is really 30 kW, or is that just the nameplate on the motor? Maybe you load motor part of the time, and it runs no-load part of the time?
How long do you want the battery to last before it is worn out?
30 kW for 12 hours is 360 kWh. Make that 20 hour for some cushion, 600 kWh usable capacity.
I would think of forklift batteries, draining to 80% DoD, so get 750 kWh.
In my area, a 50 kWh (1000 Ah, 48V) battery is $8000
So 15 of those would have the capacity, about $120,000
Used batteries may be an alternative. Forklift companies sell reconditioned.
For this size system, there may be other batteries from locomotives or submarines.
Also telecom companies.
The other guys here are familiar with Lithium which I haven't used. It will last for more deep discharge cycles, but costs more.
You can get by with a smaller battery if you have a diesel generator, to provide power during overcast days or shorter winter days.
Hedges
I See Electromagnetic Fields!
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Variable-frequency drive - Wikipedia
Motor Starting & Running Current Calculator
AC motor starting & running current calculator & formula - to calculate starting, running & full-load current of 3 phase AC induction motor.
getcalc.com
Motor start with VFD - MB Drive Services
Motor start in VFD duty. Comparison of direct on-line start and VFD motor start. Elimination og high starting current. Superior starting torque.
mb-drive-services.com
A cheap VFD just has 6 diodes to rectify 3-phase AC onto a capacitor, then runs the motor with an inverter. (Current draw chops the top off each sine wave.)
A good VFD has a switching power supply to draw current in proportion to voltage from each phase (looks like a resistive load), and put that on the capacitor.
I don't know how well the Victron or other inverters you consider will handle a cheap VFD.
I have transformer type battery inverters (Sunny Island) and some of my Sunny Boy PV inverters are transformerless (just transistors and inductors between PV panels and utility AC line.) When I ran a small VFD, an error was reported by one of the transformerless inverters.
I suggest you look up what VFD you might want, see if it is "Power Factor Corrected", and check with Victron to see what they think about your application.
Last edited:
I was assuming you were planning on using a large solar panel array and the battery would be just to buffer the load from variations in solar input. To run off batteries for 24 hours is going to take a seriously big battery pack. I hope you have deep pockets.
OK, first things first.
For this to make any sense we have to know what your load demand is actually like. Basically what percentage of the motors capacity does it take to run your load? Most of the time motors are loafing (running under 50% of capacity) and the reserve capacity is there for starting the system up and dealing with momentary increases in demand. In many applications the motor is not constantly running. The percentage of time the motor is running is called duty cycle.
Some likely applications (like running a well ) are a pretty constant load, but hopefully you are using a comfortably oversized motor (so the motor will last longer). I can't help you figure what your load or duty cycle are, but once you know this data we can help you refine the calculate of what it will take to power it.
Do you have power bills that show power consumption usage by the motor. That will tell us everything we need to know. Is the motor currently in use and is there any way your could measure how much power it is using? This is important data to have, that is is worth it to pay an electrician to come out and meter the motor.
Lets make some assumptions and see where this takes us. Once you have real numbers you can substitute them in my example.
Assume steady state power demand from the load is 10 HP (a reasonable guess based on conservatively engineered system). Next assume this motor is going to be run with a 50% duty cycle.
750W = horsepower so 10 HP = 7500W. A 50% duty cycle means the motor is going to use 3750 Watts per hour. Operating it for 24 hours = 90 kWH total.
If you change the motor power used or the duty cycle then the kWH per 24 hours will change.
Now we will try to take into account energy conversion efficiency. Some reasonable assumptions here. You will need to replace these numbers with the actual performance of whatever gear you select has.
- A 3 phase synchronous motor has efficiencies around 95%
- VFD efficiency should be around 90%
- Inverter efficiency should be around 90%
- Total conversion efficiency from DC to motor output = 95% x 90% x 90% = 77%
Next your battery type has to be taken into account. I am going to assume you will go with a 48V battery system.
Deep Discharge Lead Acid: I suggest you use industrial (forklift) batteries. A typical example would be something like a Rolls 4KS-21PS. This is a 4V, 1100 AH cell (4400 WH) that will give you 3000 recharge cycles as long as you don't discharge it below 25%. That is comparable life to what you can get with a LIFEPO4 battery.
4 KS 21P | Rolls Battery
To use 117 kWH of this battery capacity requires you to have 146 kWH of battery capacity. 32 of the Rolls 4KS-21PS will give you 140 kWH of battery capacity which is close enough. These cost about $1K each which means you will be paying ~ $30K for this battery pack. That price is a guess because I don't know what shipping is going to cost or what kind of quantity discount you could get. I bet the two will pretty much cancel out.
Rolls Surrette 4KS21P 4v 1104 AH
We offer an additional 2% discount* for cash, check or wire transfer.
www.thesolarbiz.com
Lithium (LIFEPO4): Depth of discharge can be 0%, but I wouldn't go below 10%, so lets say you would need 130 kWH of lithium batteries. Assuming a DIY system made from the Xuba sourced 280 AH batteries. 3.2V @ 280 AH = 896 WH. Eight of these batteries cost me right at $110 each (including shipping). In the quantities you are going to be buying them let's assume you can get them for $100 each (a guess). 144 of them will give you 129 kWH and cost $14,400 delivered. Add $600 for BMS and stuff and a final price of $15,000 is reasonable.
Based on the frankly amazing price you can get these 280 AH cells for, they are obviously the best choice from a financial standpoint. They will also weigh a lot less if that matters.
Now you have to replace my example usage numbers with real data.
- What motor power does your load actually require.
- What percentage of time will the motor actually be running.
- What do these cells cost in the quantities you will be buying them.
I have no idea what a solar panel system to power this is going to cost. I hope you have a lot of sunny days where your farm is.
Last edited:
Victron inverters are transformer based. At least my Multiplus 24/2000 is. Considering how much a Quattro weighs, I bet it has a power transformer inside it as well.Variable-frequency drive - Wikipedia
en.wikipedia.org
Motor Starting & Running Current Calculator
AC motor starting & running current calculator & formula - to calculate starting, running & full-load current of 3 phase AC induction motor.
Motor start with VFD - MB Drive Services
Motor start in VFD duty. Comparison of direct on-line start and VFD motor start. Elimination og high starting current. Superior starting torque.
A cheap VFD just has 6 diodes to rectify 3-phase AC onto a capacitor, then runs the motor with an inverter. (Current draw shops the top off each sine wave.)
A good VFD has a switching power supply to draw current in proportion to voltage from each phase (looks like a resistive load), and put that on the capacitor.
I don't know how well the Victron or other inverters you consider will handle a cheap VFD.
I have transformer type battery inverters (Sunny Island) and some of my Sunny Boy PV inverters are transformerless (just transistors and inductors between PV panels and utility AC line.) When I ran a small VFD, an error was reported by one of the transformerless inverters.
I suggest you look up what VFD you might want, see if it is "Power Factor Corrected", and check with Victron to see what they think about your application.
arthurgeorge
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- Sep 26, 2020
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thanks your idea helped me alot in getting the best design for my project.. waiting to start i will always update you as we progress with projectI was assuming you were planning on using a large solar panel array and the battery would be just to buffer the load from variations in solar input. To run off batteries for 24 hours is going to take a seriously big battery pack. I hope you have deep pockets.
OK, first things first.
For this to make any sense we have to know what your load demand is actually like. Basically what percentage of the motors capacity does it take to run your load? Most of the time motors are loafing (running under 50% of capacity) and the reserve capacity is there for starting the system up and dealing with momentary increases in demand. In many applications the motor is not constantly running. The percentage of time the motor is running is called duty cycle.
Some likely applications (like running a well ) are a pretty constant load, but hopefully you are using a comfortably oversized motor (so the motor will last longer). I can't help you figure what your load or duty cycle are, but once you know this data we can help you refine the calculate of what it will take to power it.
Do you have power bills that show power consumption usage by the motor. That will tell us everything we need to know. Is the motor currently in use and is there any way your could measure how much power it is using? This is important data to have, that is is worth it to pay an electrician to come out and meter the motor.
Lets make some assumptions and see where this takes us. Once you have real numbers you can substitute them in my example.
Assume steady state power demand from the load is 10 HP (a reasonable guess based on conservatively engineered system). Next assume this motor is going to be run with a 50% duty cycle.
750W = horsepower so 10 HP = 7500W. A 50% duty cycle means the motor is going to use 3750 Watts per hour. Operating it for 24 hours = 90 kWH total.
If you change the motor power used or the duty cycle then the kWH per 24 hours will change.
Now we will try to take into account energy conversion efficiency. Some reasonable assumptions here. You will need to replace these numbers with the actual performance of whatever gear you select has.
This means to get 90 kWH of motor output will require 90 kWH / 77% = 117 kWH.
- A 3 phase synchronous motor has efficiencies around 95%
- VFD efficiency should be around 90%
- Inverter efficiency should be around 90%
- Total conversion efficiency from DC to motor output = 95% x 90% x 90% = 77%
Next your battery type has to be taken into account. I am going to assume you will go with a 48V battery system.
Deep Discharge Lead Acid: I suggest you use industrial (forklift) batteries. A typical example would be something like a Rolls 4KS-21PS. This is a 4V, 1100 AH cell (4400 WH) that will give you 3000 recharge cycles as long as you don't discharge it below 25%. That is comparable life to what you can get with a LIFEPO4 battery.
4 KS 21P | Rolls Battery
rollsbattery.com
To use 117 kWH of this battery capacity requires you to have 146 kWH of battery capacity. 32 of the Rolls 4KS-21PS will give you 140 kWH of battery capacity which is close enough. These cost about $1K each which means you will be paying ~ $30K for this battery pack. That price is a guess because I don't know what shipping is going to cost or what kind of quantity discount you could get. I bet the two will pretty much cancel out.
Rolls Surrette 4KS21P 4v 1104 AH
We offer an additional 2% discount* for cash, check or wire transfer.
Lithium (LIFEPO4): Depth of discharge can be 0%, but I wouldn't go below 10%, so lets say you would need 130 kWH of lithium batteries. Assuming a DIY system made from the Xuba sourced 280 AH batteries. 3.2V @ 280 AH = 896 WH. Eight of these batteries cost me right at $110 each (including shipping). In the quantities you are going to be buying them let's assume you can get them for $100 each (a guess). 144 of them will give you 129 kWH and cost $14,400 delivered. Add $600 for BMS and stuff and a final price of $15,000 is reasonable.
Based on the frankly amazing price you can get these 280 AH cells for, they are obviously the best choice from a financial standpoint. They will also weigh a lot less if that matters.
Now you have to replace my example usage numbers with real data.
-Edit- If you use commercial 12V lithium batteries then the cost will be dramatically higher and the forklift batteries could end up being competitive on cost.
- What motor power does your load actually require.
- What percentage of time will the motor actually be running.
- What do these cells cost in the quantities you will be buying them.
I have no idea what a solar panel system to power this is going to cost. I hope you have a lot of sunny days where your farm is.
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