Current Parameters PH

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Sir,

Could you please explain the formula used to find

CURRENT WAVEFORM SHAPE PARAMETERS

IAVG, IP and IRMS in link switch PH DEVICE.

Even those it is automatically calculate in spreadsheet.

Thanks in advance

Ravik.

The expressions for RMS, and average current for any PFC based solution is not a flat calculation. It is derived by taking the RMS current of every switching instance (IRMSn) over an entire switching cycle (or half cycle)

You then rms sum each of the individual rms currents to get the aggregate RMS current for an entire line cycle.

IRMS = (IRMS0^2 + IRMS1^2 + IRMS2^2 +... +IRMS659^2)^0.5

 (this is because at 50 Hz and 66 Khx swicting freq, and 50 Hz line frequency there will be 660 switching events over a  half line cycle)

 

I know it looks complicated but hope that its makes somewhat sense...