A Modified Multifrequency Passivity-Based Control for Shunt Active Power Filter With Model-Parameter-Adaptive Capability

The passivity-based control (PBC) has a better control performance using an accurate mathematical model of the control object. It can offer an alternative tracking control scheme for the shunt active power filter (SAPF). However, the conventional PBC-based SAPF cannot achieve zero steady-state current error with the inaccurate model. In order to handle the steady-state current error of the conventional PBC-based SAPF, a modified PBC scheme is proposed, where an error proportional-integral regulator is inserted into the coupling loop. The design of the modified PBC is implemented in the dc model, transferred from the ac model by using a fast Fourier transform. A comparative performance analysis is carried out between the conventional and modified PBC-based SAPFs. A 380-V/75-A prototype is developed, where the results demonstrate that by using the modified PBC, the zero steady-state current error of SAPF can be achieved at the selected frequency or frequencies, even though the model used is not so accurate.