Non Linear Load Bank Design

[bogue]

Need to build a Non Linear Load Bank which would have a Crest Factor of 3:1, single Phase 208 VAC, 60 hZ Power,
approximate 10 kVA, at a power factor in the range of
0.8 to 1.

Using Rectifier, Caps and Resistive Load, the highest Crest Factor we obtain is 2.5:1

 

[logbook]

Well a FAST rectifier and a decent capacitor will produce an arbitrarily high crest factor load. However will your source support such a crest factor? the trouble with teh mains as a source is that standard mains is harmonically distorted. Look at the waveform and the sinusoid is flat topped. Hence it will not support very high crest factors. You may therefore need a better source.

 

[ScottyUK]

More capacitance, and lower ESR / ESL values should give you the desired effect if, as jraef has already said, the source impedance including whatever interconnects you're using is low enough to allow a 3:1 crest factor. Look for capacitors designed for power electronic service - inverter or UPS applications - rather than standard electrolytics.



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If we learn from our mistakes I'm getting a great education!

 

[wrong100]

bogue

The two previous replies are correct, just not enought details. Also you did not give detailes.

If you want current for a power supply,
do not do rms or pf.
Use instance PK*Time and RMS numbers (source / load at peak curent).

Comment; the standerd for power supplies (PF)is,
apperent power / real power.
Note: 1) The basic reduces to energy in
(volts*I*rms)/( rms power out).
2) The total Z on the load includes the discharge resistor.
3 You can modify for a larger cap by adding a
resistor in series.

If you want lagging current iductors must be sized.

Suggestion: 1)put in a resistor to draw the needed load.
2)add C=I*t/v
c= cap
I= current
t= tine (60*2/1=8.33*10-3= .00833)
v= acceptle voltage ripple (Must subtract cap Z
from this number.

There is enough info Here to do what you want

USE IT " THINK "