Voltage output calculation

Hi all,

Here I use sinamics PM240-2 togrther with cu240-2 (75kw), The load is electrical instrument like a battery charger, heaters, lighting, HPU motors and so on. Now I already can run all this equipment but the problem is output voltage from VFD is not state in 400v when we change the load capacity, For example when the load is only 20A the voltage is 400v but when we add another load for example 40A the output voltage is decrease to 380v. What I need is, no matter what the load capacity Amps is, the output voltage from VFD is maintain in 400v. Can we do that?

REALLY NEED HELP.

Thanks in advance.

Hi,

Thanks for the answer, For control mode I use Linear Characteristic, and the ramp up and ramp down time is 0s because the load need immidiately 50hz. And for your information before the output voltage go to the instrument I already put the LC Filter to change the square wave to sine wave, and all the instrument is already can on, but the problem is just the output voltage is not stable when load is change. My customer need the voltage stable at 400v only.

Hi,

I already play with parameter P0304(output voltage) when I set to 422v with load 20A the voltage is stable at 400v, but when load is up to 40A the output voltage going down to 380v. They need the frequency 50hz and voltage 400v to supply for their electrical instrument throught third party LC Filter.

Please advise.

Thanks.

Hi,

Thanks for the answer, I will try like your suggestion. Will come back to you if not working.

Thank you.

HI,

Sorry forgot to mentioned about this. When no load present the input voltage and output voltage is 400v but when run with load the ouput voltage is dropping to 380v.

Any Idea? please advise.

Dear Expert,

Thanks for your answer, Now my input voltage is 430v, if output voltage is 95% from input voltage should be 409v, I can get 409v without load but when the load present only 22A the voltage drop to 390v, maybe because of the input voltage also drop(I'm not sure). Can I just set the input voltage higher? For example I set the input voltage to 480v, can I do that thing?

Thanks in advance.