Due to the high level of compensation with parallel reactors and series capacitors at the 500 kV transmission lines that interconnect the South and North regions of Brazil (from Serra da Mesa to Imperatriz substation), and the long distance compensation with parallel reactors at the South-East/North-East interconnection, harmonic resonances around 120 Hz and others occur in this region. This concerns directly to the SVC of Bom Jesus da Lapa (BJL), since this Power Electronic Compensator is capable of responding in this frequency range. This paper shows the capability of the SVC to attenuate harmonic resonances.