Adaptive Voltage Saturation Algorithms for Selective Harmonic Control in Shunt Active Power Filters

In this paper three adaptive algorithms for the exploitation of the DC-link voltage in shunt active power filters, based on an array of proportional-resonant current regulators, are developed, and compared. These algorithms adaptively change the voltage saturation of each regulator in order to preserve the control capability of the fundamental component of the current when the available voltage is not sufficient to control the filter current. Simultaneously, they try to improve the quality of the grid current because the DC-link voltage of the active power filter is allocated to the regulators to compensate only the most significant harmonics. Some experimental results are shown to demonstrate the feasibility of the three algorithms.