how to make a non linear load setup for ups testing

[somnath basak]

actually i want to make a ac load setup for testing of input current of any UPS upto 5Kva, i want use diode ,capacitor and resistor so as per market availability of capacitors can any one suggest how can i design the whole set up with low cost and please tell me the capacitors ratings

 

[duke37]

It is not clear what you wish to do. What is the purpose of the diode and capacitor? Capacitors are expensive to pass considerable current at 50Hz.

For a load, I would use one or more 1kW radiant fire elements. You could also consider an electric motor with a water cooled brake.

 

[somnath basak]

thanks for your helpful reply, now i have attached the circuit diagram please please check it , then you wll be clear what i wnt to do, my aim is to make the load in non-linear form not as linear,please reply to me

 

[davenn]

for testing of input current of any UPS upto 5Kva,

Input ?? input from where ?

what does U connect to ?
What is Uc ?

5 kV/A diodes will be VERY difficult to find and freakin' expensive



Dave

 

[(*steve*)]

The suggestion to use heater elements is a good one. You can simply switch them in and out to change the load.

 

[somnath basak]

here my U equals 230V and Uc is approx 280-290V, and the bridge rectifier i think of 15A approx then what will be the rating of the capacitor i have to used???????? and thanks Steve , but if i used heater element then the load is in linear form and my aim is to make a load of non linear from

 

[davenn]

here my U equals 230V and Uc is approx 280-290V, and the bridge rectifier i think of 15A approx

OK thanks

then what will be the rating of the capacitor i have to used????????

400V rated and it's value in uF will depend on how much ripple you are willing or allowed to accept to still produce the desired results

but if i used heater element then the load is in linear form and my aim is to make a load of non linear

it will have a reasonable bit of non-linearity as the resistance of the element wire will change as it heats up

 

[(*steve*)]

What form of non-linearity is desired?

Constant current, constant voltage, constant power, negative resistance, etc...

 

[pgib8]

For the inductive load, I'd go with a vacuum cleaner or if that's too much, maybe a blender, or if that's too much some kind of fan. Finding a capacitive load in the household sounds a bit more tricky but buying one or more properly rated capacitors should do the trick. To add some real resistance I'd go with incandescent light bulbs. Then you can mix and match all those to pretty much make any load you want.
If you need to distort the load, plug in every switching power supply you can muster and draw current from them too. If you want to push it even further, I think any motor with the carbon brushes (like a cheap blender) will do nicely, if you smell the ozone you're on the right track

 

[somnath basak]

thanks gentlemen for your information i have try it and its works, the main problem its resistor which i have connected to parallel to capacitor, it have high inrush current otherwise the circuit works, sir i want to know that you have suggested me 400V capacitor, so how did you calculate or suggested exactly 400V capacitor can you please elaborate it, i have try with 440V capacitor and again sorry for late reply, hopes you are fine , have a great time................