Friday, March 27, 2009

Regenerative Loading of Inverters


This is the popular loading method for high power inverters. The inverter is configured as current mode inverter and referance sine wave is generated from utility.The referance amlitude is audjested for variying load.If we load 100KVA online ups full load we need only the power loss which will happen in UPS.Ie if efficiency of ups is 95% we need only 5KW from line to load full 100KW.

Wednesday, March 11, 2009

Next generation power devices

http://www.cree.com/products/power_docs.asp

best power electronics links

http://sureshks.netfirms.com/article/articles.htm
http://www.ivobarbi.com/zstart.php

APC UPS Circuits

for APC UPS circuits
http://www.eserviceinfo.com/equipment_mfg/APC_23.html
for service manuals
http://www.eserviceinfo.com/browse.php

Sunday, March 8, 2009

Unipolar PWM

Uni Polar PWM

Basic circuit of unipolar sinewave PWM


sine wave referance triangle wave and PWM waveforms

sine triangle and output

Bipolar PWM

Following is the basic circuit of bipolar PWM and its waveforms
circuit diagram

Waveforms of this circuit

triangle wave sine wave and PWM output

PWM and Output
Sinewave triangle wave and output

Saturday, March 7, 2009

90V to 500V AC SMPS




here is the circuit of 90V to 500V ac input power supply with battery backup.


Or u can call dc UPS