Shunt active power filter control for compensating current power quality problems in three-phase three-wire systems based on an adaptive notch filter

In this paper, a scheme is presented for properly compensating current power quality problems in a network. In this method, only by measuring grid current and using an adaptive notch filter (ANF), a reference sinusoidal current that is in phase with the grid voltage is created for the control system. Using ANFs guarantees the proper efficiency of the network when its frequency changes. A proportional controller and a resonance bank along with pulse width modulation are used in the shunt active power filter (SAPF) control system. One of the features of the resonant controller is its extremely high open-loop gain at its resonance frequency. This high gain causes the controller to accurately track the harmonic components. Simulations are carried out in MATLAB software under various conditions of load and network voltage, such as unbalanced and distortional voltage and changing load. These simulations verify the capabilities of this scheme.