50 Hz testing

[thinker]

We need to power-up and test a hydraulic power unit built for Europe and designed for 3 phase power entry 400V, 50Hz,
32 FLA. We also have operational VFD (PWM based). There is a suggestion to use this VFD as a power source to test the above unit setting VFD output parameters to 400V @ 50Hz. We also have a concern about non-sine waveform of VFD output voltage and plan to install 5% impedance output reactor. Can anybody advise is this an acceptable solution or we might need to install additional filters? The unit fed from VFD contains several induction motors, power supplies, PLC,
HMI screen some controls and instrumentation.

 

[Skogsgurra]

thinker,

Your thinking is good. The motors and transformers will work just fine on the VFD output. But your power supplies could have a problem with the HF components. The ripple in the DC capacitors will probably be quite high and that will make them explode (yes, seen that). You should also look out for EMI filters on the PLC input. It will surely get overloaded by the HF components of the PWM voltage.

I think that a sine filter should be installed before you do tis. Also keep in mind that a DOL induction motor will take between 5 and ten times rated current when you start it. Make sure that your VFD can deliver that current.

 

[busbar]

A rental trailer-mounted engine-generator set may be another option.

 

[nbucska]

If the designer(s) find the VFD acceptable ( perhaps with
the mod's suggested by SKG ) get the agreements from
the buyer.


<nbucska@pcperipherals DOT com> subj: eng-tips

 

[thinker]

Thanks everybody for responses. I already located the M-G set available for rent (as a last resort), and we'll try to filter out PWM voltage.