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Technical catalog for Susol & Metasol ACB
Technical catalog for Susol & Metasol ACB
D
2. Reactive Power Calculation
1) Reactive power is V Q (current) and it is defined as an integrated average about 1 cycle.
2) Q (current) means the current delayed by 90°. Correctly speaking, it is not transferring the fundamental waveform
by 90° but transferring all harmonics by 90°.
3) Therefore, transferring all the elements of the frequency by 90° is available when current is processed into the
frequency area, do conjugation
1)
process (transferring by 90°) with the frequency, and then reproduce it into a
waveform after moving it to the time area again.
4) Above process needs numerous calculations for these steps: waveform FFT
2)
conjugation about all the
frequency IFFT
3)
Q (waveform).
5) In case of P/S type, to solve difficulties above, it executes 90° phase transfer of voltage instead of current
compared to the base of the fundamental wave. It is used with the current to get the reactive power.
6) Therefore, reactive power is processed with Q (voltage) I.
Power calculation for P, S Type
i(k) : Instantaneous value of current waveform (Sampling value)
v(k): Instantaneous value of voltage waveform (Sampling value)
N : Sampling value of 1 cycle
i(k) : Instantaneous value of current waveform (Sampling value)
Q(v(k)) : Instantaneous value of voltage waveform after a 90° phase transfer (Sampling value)
N : Sampling value of 1 cycle
1) Conjugation: process a complex number
R+jX
R jX
2) FFT : Fast Fourier Transformation
3) IFFT: Inverse Fast Fourier Transformation
P =
1
N
i(k)v(k)
N-1
k=0
Q =
1
N
i(k)
Q(v(k))
N-1
k=0
1. Active Power Calculation
1) Active power is V I and it is defined as an integrated average about 1 cycle.
2) Therefore, according to the pulse angle difference between V and I, the active power could be consumed or
produced.
3) Hence, the sample value during 1 cycle have to be operated or transacted separately.
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