Selective SAPF for Harmonic and Interharmonic Compensation Using an Adaptive Kalman Filter-Based Identification Method

This work presents the application of a hybrid adaptive Kalman filter (HAKF) for the implementation of a shunt active power filter (SAPF), enabling selective harmonic and interharmonic compensation in real time. The hybrid term refers to the combination of a DFT-based harmonic grouping method with the adaptive Kalman estimation framework, which preserves the classical estimation method of the Kalman filter while dynamically defining its state-space model according to the spectral composition of the load current. This allows the accurate identification and parametrization of the HAKF state matrices and ensures precise individual quantification of each frequency component. In this way, the SAPF control system can select individual components to be eliminated, either totally or partially. Selective compensation is particularly useful when the compensating current required for full mitigation of the nonfundamental frequency components exceeds the SAPF current capability. Partial compensation can also be employed to match the compensating current with the maximum allowable SAPF current. Based on this, a simple selective compensation strategy is proposed to demonstrate the effective behavior of the SAPF under such conditions. A single-phase power system consisting of the proposed SAPF and a nonlinear load has been simulated using Matlab/Simulink. The simulation results confirm the effectiveness of the proposed system in mitigating harmonics and interharmonics, thereby enhancing power quality, while validating both the current processing method and the use of the HAKF in the implementation of the selective SAPF.