VFD for Fuel Dispensers at gas station

I run a fuel station ( petrol ). Each fuel dispensers installed have a 1hp suction motor ( Single Phase, 220VAC, 50 HZ ) installed.
As I plan to install Solar Power system for running of my fuel station, so I would like to decrease the starting torque load of these dispenser motors, and for this I think that I need to install VFD with each suction motor.
Please note that in one hour ( 60 minutes ), the number of starts of each motor is about 30, meaning that motor starts every 2 minutes, therefore need to decrease the torque current is imminent to decrease the capital expenditure of solar PV panels, and batteries.
Please suggest what size / wattage of VFD would serve my purpose, to nullify the starting torque current of these dispensers motors. Or there is any other way to reduce the torque current, advise me that as well.
Thanks in advance

You should probably start with some data acquisition, logging the current requirements of one of the pump motors in use. The average user will torture the thing far more than you would in dedicated testing. I've seen folks at a pump squeeze the lever twice a second for ten seconds trying to achieve what they think is "full", or creeping up on their $10 target -- whatever. I don't know if the pump actually starts that many times in quick succession, or if there's some residual pressure. But if you alter the start-up profile and it confuses the end user into thinking it's not working, and they need to stop and start again, they'll start banging on the pumps 'cause they're "not working".

If you change your motors to 3 phase, you'll have a lot more VFD choices, too. Or, go straight to DC from your battery bank, and bypass AC altogether. Motor control will still be a challenge, though. I have read tales of folks going from DC VFD input to AC VFD output, with either a custom or hacked controller. Didn't stop to investigate, so I have no details. And it could have been a pipe dream, too.

And of course, local regulation could have a lot to say about making modifications to fuel delivery electrical systems and components...

I would seriously consider replacing the electric motors with air (pneumatic) motors, and using the PV array to run one big compressor with a really big accumulator tank. You can govern pump motor start-up with regulators, there will be no sparks, only one motor will start every 15 minutes or so, and the start-up profile of that motor can be optimized for electrical efficiency, without regard to customer perception, etc. Motor can start unloaded, and be loaded only when up-to-speed. Sourcing proper air motors with the right torque curves would be needed, of course.

Chip

The net energy consumption in an air system is likely to be far higher than electric motors because so much of the energy goes up in heat of compression. Look at the specs on air motors, comparing the output hp to the size of compressor recommended. You would do a lot better with hydraulic motors and an accumulator.

Bill

I'll be the first to admit my exposure to air motors ends at whatever pneumatic drill I have in my hand. There may be other air-driven pump solutions that stop short of actually pressurizing the underground tanks, which I'm sure is not allowed. He also could run the compressor or hydraulics on gas, though, as it's likely he'll have enough.

Chip

They fill and leave in 2 minutes...that seems fast.

Check first with gas dispenser manufacturers as well as local energy folks as there may already by things off the shelf just for this as well as possible rebates for converting to solar.

You are not the first to have done this.

Tony Quiring said:

They fill and leave in 2 minutes...that seems fast.

Check first with gas dispenser manufacturers as well as local energy folks as there may already by things off the shelf just for this as well as possible rebates for converting to solar.

You are not the first to have done this.

Click to expand...

Sorry..can't help it! Have you looked at the OP's location?

Stuart

I think I recall discussions, though I do not remember enough to find my way back to them, that at least some makes and models of VFDs are unhappy/ function poorly if run on power other than the (close to) pure sinewave on-grid power- apparently some don't do well powered by generators, and most generators' waveform is better than many inverters' waveforms. Full sinewave inverters exist, but usually carry a substantial price premium. Not trying to rain on any parades, just suggest that you check carefully to avoid disappointment and surprise.

Could you find brushless DC permanent magnet motors to drive your pumps? That'd skip both the inverter and the VFD, and the technology is going in some interesting and very efficient directions.

A GOOD VFD should run fine on a good generator.

The input side of a VFD just converts AC to DC for Main Buss.

A lot more VFD's are made for 3 phase motors, only a couple types of single phase motors, will work with single phase VFD.

The soft start feature of VFD's, will ease load on power grid, and shock to pump/hoses/valves.

Many fuel pumps are enclosed with motor, and fuel cooled.

Magnets around fuel in large amounts, will collect magnetic debris..

At all the remote locations I work..

Fuel is simply stored elevated from fill point.. Gravity is free...

If tank is underground/covered, a ramped depression can be made to get vehicles fueled.

No location on phone...

But this must have already been done many times.

A bank of panels in the sun.

A bank of batteries in the back.

Inverter to create power.

Duh!

Old stale stuff.

Panels are cheap now as are batteries and inverters.

Maybe not so much there but cannot be thst tough.

Fuel Pumps

digimart

You normally can't run a single phase motor from a three phase VFD.

To limit the number of starts and starting current, you use 1 underground pump mounted on or in the storage tank, to feed several dispensers at the same time. Any dispenser calling for fuel will trigger the single pump, when all dispensers stop the call for delivery the pump shuts off. Been done that way for many years now.

Red hat tank pumps come in three phase models, and are the industry standard.
The Red Jacket Submersible Turbine Pump

You could eliminate the AC pumps altogether and use a DC pump directly from your batteries.
Fill-Rite Pumps Fuel Transfer Pumps From Tuthill



SAF Ω