Computing voltage and current amplitude and average power
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I have three sinusoidal waveforms namely, voltage, current, and power acquired using an oscilloscope which I then have connected to my computer that runs Matlab. I need to compute the voltage and current amplitudes and the average power using the following formulae.
- Voltage Amplitude =
- Current Amplitude =
- Average Power =
where, represent the period, instantaneous current and voltage respectively. How do I use the waveforms obtained via the oscilloscope to find the above amplitudes and power?
hosein Javan on 13 Aug 2020
if they are 3-phase, use clarke transformation. it will give you the amplitude and phase the dividing by sqrt(2) yield the rms value. multiplying V_rms*I_rms = P_average.
if they are single phase. and you know the instantaneous frequency, use sliding average "movmean" function to calculate it. there are simulink blocks available for such task.
if they are single phase and you don't know the instantaneous frequency, then you have to use "PLL" to measure phase or frequency to calculate rms values.