A shunt active filter based on the instantaneous active and reactive curren
t component i(d)-i(q) method is proposed. This new control method aims to c
ompensate harmonics and first harmonic unbalance. To evaluate its relative
performance it is compared with the instantaneous active and reactive power
p-q method under various mains voltage conditions and for different harmon
ic injection high-pass filters. Both methods are completely frequency-indep
endent, however under distorted mains voltages the proposed method presents
a better harmonic compensation performance. The system synthesis and imple
mentation are performed. Simulation and experimental results are presented.