The increase in non-linear loads in the electrical network deteriorates the voltage waveform quality. One of the most used methods to correct the quality lack is to use shunt, series or mixed topologies of active power filters. Mixed filters can compensate loads that generate voltage harmonics and current harmonics, but the economic investment is high. Commercial shunt filters are more widespread due to their design, modularity and cost; although their non-linear load tracking capability is limited. The aim of this work is to improve the shunt active filter reference tracking, designing a variable reactance at the filter output. The validity of the proposed design is analyzed through a Matlab-Simulink platform.