Look at the waveform actually produced ( in yellow). I rest my case.
Looking for a big 3 phase hybrid inverter ≥50 kW
- Thread starter solarbauer
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MaximusAnonus
New Member
"upset" how? Could you provide a bit more info on that? As I have quite a lot machinery with VFDs I wonder what happens when I try to power them.
Hedges
I See Electromagnetic Fields!
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I replaced single-speed pool pump with 3-phase and VFD years ago. I also had SMA SWR2500U grid-tie PV inverters.
With both connected to the bottomless grid, never had a problem.
After I installed Sunny Island, I replaced the GT PV inverters with (transformerless) SB 10000TL-US, because it would respond to frequency shift. When it tried to reconnect to island grid (generated by SI) while VFD was operating, it reported an internal error. Probably looking at voltages on its input and couldn't make sense of them.
Because Sunny Island was not bothered by the load, I thought transformer filtered higher frequencies. I replaced the Sunny Boys with 5000US. But those threw a similar error. Something about relay failure if I remember correctly.
I'm afraid of letting them experience repeated errors, something about getting a permanent error flag set.
I think the issue only occurred when VFD was already operating at the time GT PV inverter was powered up and tried to connect to AC. It may not be a problem if VFD is not turned on (or loaded) until GT PV is already operating.
Possibly some sort of choke ("reactor") on AC input would help. I have one on output to protect motor. A single winding choke big enough to do anything at these currents and frequencies would be huge. A "reactor" or common-mode choke of course is great at blocking common-mode, but would probably pass most differential mode moderately high frequencies.
I've bought some Lambda power-factor correction modules (PF > 0.95, 120 to 240Vrms in, 360VDC 1kW out). I haven't tried them yet because they require additional support circuitry.
I've looked at AC current powering VFD. Flat line with little peaks of a sine wave, when AC voltage exceeds capacitor voltage. I tried spinning an induction motor on the AC line at the same time, thinking it would smooth out current draw, but waveform looked the same.
There are some VFD, I think the reversible ones (able to return power to the grid, e.g. as the elevator is going back down) which may not use bulk capacitors, instead chop waveform from 3 phases in to 3 phases out. Those may synthesize sine-wave current draw, needing only a bit of HF filtering. Others use PWM boost converter to synthesize sine-wave current draw (like the Lambda modules I got).
With both connected to the bottomless grid, never had a problem.
After I installed Sunny Island, I replaced the GT PV inverters with (transformerless) SB 10000TL-US, because it would respond to frequency shift. When it tried to reconnect to island grid (generated by SI) while VFD was operating, it reported an internal error. Probably looking at voltages on its input and couldn't make sense of them.
Because Sunny Island was not bothered by the load, I thought transformer filtered higher frequencies. I replaced the Sunny Boys with 5000US. But those threw a similar error. Something about relay failure if I remember correctly.
I'm afraid of letting them experience repeated errors, something about getting a permanent error flag set.
I think the issue only occurred when VFD was already operating at the time GT PV inverter was powered up and tried to connect to AC. It may not be a problem if VFD is not turned on (or loaded) until GT PV is already operating.
Possibly some sort of choke ("reactor") on AC input would help. I have one on output to protect motor. A single winding choke big enough to do anything at these currents and frequencies would be huge. A "reactor" or common-mode choke of course is great at blocking common-mode, but would probably pass most differential mode moderately high frequencies.
I've bought some Lambda power-factor correction modules (PF > 0.95, 120 to 240Vrms in, 360VDC 1kW out). I haven't tried them yet because they require additional support circuitry.
I've looked at AC current powering VFD. Flat line with little peaks of a sine wave, when AC voltage exceeds capacitor voltage. I tried spinning an induction motor on the AC line at the same time, thinking it would smooth out current draw, but waveform looked the same.
There are some VFD, I think the reversible ones (able to return power to the grid, e.g. as the elevator is going back down) which may not use bulk capacitors, instead chop waveform from 3 phases in to 3 phases out. Those may synthesize sine-wave current draw, needing only a bit of HF filtering. Others use PWM boost converter to synthesize sine-wave current draw (like the Lambda modules I got).
Pretty sure that's the waveform seen by the compressor, not the inverter/power source. The equipment generating the waveform is going to be seeing many other loads, none of which would be encountering that particular waveform.
Hedges
I See Electromagnetic Fields!
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Scroll down to 3rd scope shot, which shows AC current and battery current, for 48V inverters powering AC feeding VFD driving 2 HP pool pump. No hash, but far from sine wave current. The current transformer used wouldn't have had the bandwidth to show hash; I'll check again some day with my 20 kHz proble.
diysolarforum.com
Battery ripple current
After reading of someone tripping battery breakers at well below rating, I realized that could be due to pulses of current drawn by the inverter. Ideally capacitors would smooth out current draw so high frequency switching pulses and 60 Hz draw all came from the caps, and current from batteries...
diysolarforum.com
Nobodybusiness
Collecting the leftovers of the Great Sky Reactor.
You need 3 units to do 3 phase if you use Solark regardless of the wattage output unless you want to use VFD everywhere.You can parallel more than one inverter. Get as many as you need to handle your power requirements. If money was no issue, I'd recommend the Sol-Ark 15k. Start with 2 and see if they can handle the loads.
Sol-Ark 15K All-In-One
Sol-Ark® 15K-2P solar hybrid inverter is powerful and military-grade that is scalable, battery-agnostic, and a true whole home backup. Learn more.www.sol-ark.com
Here are two 12k inverters installed in parallel:
Deye inverter single phase or 3 phases.low voltage or high voltage
https://www.deyeinverter.com/produc...-Hybrid-Inverter-Low-Voltage-Battery-327.html or
https://www.deyeinverter.com/produc...-Hybrid-Inverter-Low-Voltage-Battery-338.html or
www.deyeinverter.com
www.deyeinverter.com
Deye and Sol Ark is the same manufacturer, but different prices
https://www.deyeinverter.com/produc...-Hybrid-Inverter-Low-Voltage-Battery-327.html or
https://www.deyeinverter.com/produc...-Hybrid-Inverter-Low-Voltage-Battery-338.html or
SUN-5/6/8/10/12K-SG04LP3 | 5-12KW | Three Phase | 2 MPPT | Hybrid Inverter | Low Voltage Battery Inverter Company, Supplier | Deye Inverter Technology
NingBo Deye Inverter Technology Co.,Ltd is China SUN-5/6/8/10/12K-SG04LP3 | 5-12KW | Three Phase | 2 MPPT | Hybrid Inverter | Low Voltage Battery inverter company and supplier。 SUN 5/6/8/10/12K-SG is brand new three phase hybrid inverter with low battery voltage 48V, ensuring system saf...
www.deyeinverter.com
SUN-25/30/40/50K-SG01HP3-EU-BM2/3/4 | 25-50KW | Three Phase | 2 MPPT | Hybrid Inverter | High Voltage Battery Inverter Company, Supplier | Deye Inverter Technology
NingBo Deye Inverter Technology Co.,Ltd is China SUN-25/30/40/50K-SG01HP3-EU-BM2/3/4 | 25-50KW | Three Phase | 2 MPPT | Hybrid Inverter | High Voltage Battery inverter company and supplier。 SUN-25/30/40/50K-SG01HP3-EU-BM2/3/4 is brand new three phase hybrid inverter with High voltage battery...
www.deyeinverter.com
Last edited:
solarbauer
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- Sep 19, 2022
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- 8
Wow those look great. The 50kW version is very interesting because you don't need that high of a voltage. The 20kW SofarSolar one I linked earlier in the thread would only work with 400V and above batteries. The Deye should work from 160V which is nice. The master slave BMS tech gets quite expensive the higher the voltage.
