Ok, so back to this saga yet again.

So I have read somewhere that the software might cause issues if it is not installed in the correct directory.

Well, as I am sort of into IT, I like to install programs under the correct program folder, and not sommer any directory in C drive.

 

Right, so step 1 was to delete the old installation, reboot PC, install software under default directory , and reboot pc again.

Everything looked the same afterwards, but I did notice an extra line right a the top of the screen, under parameter settings.

Something about max feedback power = 300W

Now remember, at this stage I am running "Off Grid (III)" mode, meaning no power should ever be exported back to the grid.

I changed the setting to Zero, and next time I look, the line is gone. Poof!.

 

Anyway, so I sit down and change all the settings back to "Grid-tie with Backup".

Once the unit have updated to the new settings, I rebooted the unit.

Then configured all my other settings again, only one setting at a time, making sure to press the "Apply" button next to each setting I changed.

So, once done with all of that, re-booted the invertor again and restarted the pc as well.

 

So after all of this, we finally look to be on track again, PHEW!!!

I did some load testing to see if the invertor tripped the pre-paid meter again, but all looked ok.

So far so good....

 

So, looks to me like it could be a software related issue.

P.S. Regarding the energy measurement, I am using an Efergy unit. For now I will just ignore it's reading and count the units on the pre-paid meter.

 

For now, here is my current settings.

Any comments???

 

 

 

By setting you nominal output voltage to 230V instead of 240V, won't you save on battery power when the inverter runs from battery?

According to the inverter graphs, my input voltage sometimes goes up as high as 235V.

Also, when I had it on 230V before, I had issues with the pre-paid meter tripping.

According to the inverter graphs, my input voltage sometimes goes up as high as 235V.

Also, when I had it on 230V before, I had issues with the pre-paid meter tripping.

 

I am referring to output voltage and battery use when the output voltage setting is set to a higher value. When it is set to a higher value the inverter needs to work harder and it might use more battery power to maintain the higher voltage. I played around with that setting on my APC UPS and when I configured the output voltage to a lower value the batteries lasted much longer on idle compared to when the output voltage was set to a higher value.

 

Was the tripping caused by the "output" voltage setting or by a combination of other settings? These two should not really affect each other.

 

The output voltage setting is only applicable to the load connected to the inverter - the grid-tie voltage will follow the input voltage closely and can for obvious reasons not be specified.

I am referring to output voltage and battery use when the output voltage setting is set to a higher value. When it is set to a higher value the inverter needs to work harder and it might use more battery power to maintain the higher voltage. I played around with that setting on my APC UPS and when I configured the output voltage to a lower value the batteries lasted much longer on idle compared to when the output voltage was set to a higher value.

 

Was the tripping caused by the "output" voltage setting or by a combination of other settings? These two should not really affect each other.

 

The output voltage setting is only applicable to the load connected to the inverter - the grid-tie voltage will follow the input voltage closely and can for obvious reasons not be specified.

 

You cannot directly compare an APC UPS to the Axpert.

 

The APC UPS takes 12/24/48 or 192volts (depending on model) and inverts it to AC. So it has 24V AC, 48V AC, etc. directly from the battery (both positive and negative wires have a non-zero voltage on the APC design to achieve better efficiency given the low input voltage). This then passes through a massive low frequency transformer which boosts the voltage to mains voltage.

 

Due to the design of the APC, the inverter stage gets less efficient for higher output voltages.

 

The Axpert uses a bunch of MOSFETs which it drives at very high frequency through a transformer (at 100kHz in case of the Axpert). Transformers are much smaller if the frequency increases (but in turn the wire needs special properties due to skin effect). In fact high frequency transformers with MOSFETs running at high frequency have many good properties which is why this design has proliferated and low frequency designs are becoming less common.

 

Anyway, after it runs the power through this transformer it smoothes it out again to create DC. This DC sits at 400 odd volts, you can query this voltage using the QPIGS command which shows the DC Bus voltage.

 

That is finally inverted as is to give you AC.

 

The point?

 

The Axpert boost stage remains constant regardless of output voltage. They use PWM on the inversion stage to achieve higher or lower voltages. At higher voltages your current decreases on the inversion stage so it may even be more efficient.

 

The design is very common and genius because your output voltage can be tightly controlled even with large input voltage fluctuations.

 

tl;dr -> I wouldn't say it is less efficient at higher voltage. Testing an Axpert is the only way to know for sure but at higher voltage it may possible even be more efficient.

I know some cheaper square wave inverters also does that pwm thing, or something like it. They attempt to approach a square wave with the same average energy content as a sine wave, if you think about it visually: the area under the graph is the same. But because their boost stage is fixed, they cannot compensate for a drop in battery voltage. This is obviously much more of a problem with 12V inverters, as they have high-ratio boost stages. To compensate for the sagging voltage (which also affects the high-voltage DC side), they modify the mark/space ratio of the modified sine-wave output. Now apparently there IS a kind of MSW inverter that can control the boost stage, and this makes a better MSW inverter (if such a thing exists).

 

All that info about how the Axpert does it, very very informative. I don't know how this is usually done in practice, but I suspect there's two ways. The one is to use PWM to control the boost stage, generate a stable high voltage DC (probably 325VDC, because chopping that back into a sine wave will give you 230V RMS)... or.... boost the DC to something higher (400V) and then use a buck converter in your output stage to efficiently (usually >90%) drop it a bit.

 

I'm not an expert, but it kinda seems to me that controlling the boost stage ought to be a little more efficient.

I know some cheaper square wave inverters also does that pwm thing, or something like it. They attempt to approach a square wave with the same average energy content as a sine wave, if you think about it visually: the area under the graph is the same. But because their boost stage is fixed, they cannot compensate for a drop in battery voltage. This is obviously much more of a problem with 12V inverters, as they have high-ratio boost stages. To compensate for the sagging voltage (which also affects the high-voltage DC side), they modify the mark/space ratio of the modified sine-wave output. Now apparently there IS a kind of MSW inverter that can control the boost stage, and this makes a better MSW inverter (if such a thing exists).

 

All that info about how the Axpert does it, very very informative. I don't know how this is usually done in practice, but I suspect there's two ways. The one is to use PWM to control the boost stage, generate a stable high voltage DC (probably 325VDC, because chopping that back into a sine wave will give you 230V RMS)... or.... boost the DC to something higher (400V) and then use a buck converter in your output stage to efficiently (usually >90%) drop it a bit.

 

I'm not an expert, but it kinda seems to me that controlling the boost stage ought to be a little more efficient.

 

The boost stage on the Axpert has a constant DC voltage at around

You cannot directly compare an APC UPS to the Axpert.

 

I am not directly comparing them, I just asked Wetkit a question.   B.T.W., he has an infini inverter.

 By varying this duty cycle constantly you end up with a sine wave.

 

You end up with a waveform close to a sine wave, but still containing a lot of harmonics. 

Guys, you getting off topic....

 

Anyway, set the voltage to 230V yesterday and blink, everything goes off.

Eventually found that changing the voltage sets other stuff back to default, like the max freq at 50.1Hz.

Now we run up to 50.5Hz I have seen, so thats why the invertor tripped.

Fixed all the other settings and so far running ok.

Guys, you getting off topic....

 

Anyway, set the voltage to 230V yesterday and blink, everything goes off.

Eventually found that changing the voltage sets other stuff back to default, like the max freq at 50.1Hz.

Now we run up to 50.5Hz I have seen, so thats why the invertor tripped.

Fixed all the other settings and so far running ok.

 

Great, hope it lasts. 

i have sent you the factory password...use with care

Mike, I have a similar inverter. Can you please send me the factory password as well?

Mike, I have just installed my infini 3kW, but need the factory password to set it to NRS097. Can you send it to me?

Thanks in advance