A three-phase series active filter connected in series with a three-branch shunt passive filter (fifth, seventh, and high-pass filters as shown in Figure E11.11) is used for harmonic current and reactive power Vac ANC 415 V, 50 Hz Active filter Parallel hybrid power filter m T mon m sha reee the 4H] VSAFa Lh- T shb heee H Treeey reeet rele heee Fres Froot SAFb 2 KKH Liv VSAFC VSAF (V) ish (A) (A) i, (A) v(V) 600 0 -600 100 0 -100 100 0 -100 100 0 -100 50 0 -50 0.1 0.12 Figure E11.11 A hybrid power filter and its waveforms 0.14 0.16 0.18 0.2 Time (s) compensation in a three-phase 415 V, 50 Hz system to reduce the THD of the supply current and to improve the displacement factor to unity. It has a load of a three-phase thyristor bridge converter operating at 30 firing angle drawing constant 75 A DC current. Calculate (a) the designed values of passive filter components, (b) line current, (c) the VA rating of the APF, (d) the AC inductor value of the APF, and (e) its DC bus voltage, and (f) the DC bus capacitor value of the APF. Consider the switching frequency of 20 kHz and the DC bus voltage has to be controlled within 8% range and ripple current in the inductor is 15%. The turns ratio of the injection transformer is 1:10.