Harmonic controller for an active power line conditioner

An apparatus to construct a sinusoidal output signal corresponding to a plurality of selected harmonics of a sinusoidal input signal, said apparatus comprising:

• means for dividing said sinusoidal input signal into a plurality of direct component signals corresponding to said plurality of selected harmonics and a plurality of quadrature component signals corresponding to said selected harmonics;
• first means for controlling said plurality of direct component signals by applying a gain factor to said plurality of direct component signals and by adding an accumulating functional term, corresponding to a running sum of error terms for said sinusoidal input signal, to said plurality of direct component signals to produce a plurality of accumulated direct component signals with amplitudes corresponding to the magnitudes of said selected harmonic components;
• second means for controlling said plurality of quadrature component signals by applying a gain factor to said plurality of quadrature component signals and by adding an accumulating functional term, corresponding to a running sum of error terms of said sinusoidal input signal, to said plurality of quadrature component signals to produce a plurality of accumulated quadrature component signals with amplitudes corresponding to the magnitude of said selected harmonic components;
• first means for multiplying said accumulated direct component signals by said plurality of selected harmonic components of a cosine reference signal to provide a plurality of amplified direct component signals with phase values corresponding to said plurality of selected harmonics of said input signal;
• second means for multiplying said accumulated quadrature component signals by said plurality of predetermined harmonic components of a sine reference signal to provide a plurality of amplified quadrature component signals with phase values corresponding to said plurality of selected harmonics of said input signal;
• and
• means for adding said amplified direct component signals and said amplified quadrature component signals to form said output signal corresponding to said plurality of selected harmonics of said sinusoidal input signal.