We show that for a compensation currents vector in the form of an inactive Fryze current
Thus, in order to realize the consumption from a three-phase current source of current active current of direct sequence, the main harmonic of the compensation current should contain the following components in symmetric coordinates:
In the time domain, the compensation current vector also includes a higher harmonic vector:
A novel approach to determine reference compensation currents
of the three-phase shunt active power filter (APF) under distorted and/or imbalanced source voltages .
Compensation currents in a-AY axis are computed according to equation (6).
LPF are used in feed forward configuration to obtain harmonic compensation currents.
where [i.sub.ck] (k = a, b, c) are the APF compensation currents. As the three-phase load is symmetric, the [i.sub.ck] are symmetric, so there is
In the converter, the 1st, 2nd, and 3rd bridge are used to produce compensation current [i.sub.ca], [i.sub.cb], [i.sub.cc] of phase A, B, and C, respectively.
The biggest difference value in of both compensation currents is around [+ or -]7 A (Fig.
If is is the source current, [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII.] is the load current and iC is the compensation current then
To calculate the reference compensation currents in the a-p coordinates, the expression 3 is inverted as given below,
In order to obtain the reference compensation currents in the a-b-c coordinates the inverse of the transformation is applied to eqn 2 and is given as