Adaptive Control Algorithm For Harmonic Compensators

Abstract

will be free of harmonic pollution and the compensator performs like an active filter. If in addition t o (3) the compensator can conx’ert active power, i.e., ic.l jL 0, in which case we deal with a n Active Power Line Conditioner [31. In many instances the compensator delivers or absorbs 60 Hz reactive current, i,, # 0, such tha t the line current i is nearly in phase with the fundamental component of the voltage, or can be made purposely to lag or lead the voltage. These concepts are implemented by monitoring the currents i ~ ~ j and ixr, and adjusting the compensator current waveform and magnitude such tha t i , ~ = -ih” and ;,I = i N , l . Recent studies [4,5,6,7] point out that in low and medium voltage systems with many small or medium sized nonlinear loads scattered among the network busses it is not feasible to compensate separately each nonlinear load. At the busses where a harmonic compensator is available it is more beneficial to use the compensator for the minimization of voltage distortion in the system. This s t r a t e g is the logical one, since in such systems i t is possible to monitor bus voltages but practically impossible to monitor the currents of a miriade of small linear loads. The distortion a t a certain bus with the voltage