In this paper, the 3-phase 4-wire Shunt Active Power Filter (ShAPF) dealing with non-ideal Point of Common Coupling (PCC) voltages will be presented. The instantaneous power theory is applied to design the ShAPF controller which shows reliable performances. The Adaptive Notch Filter (ANF) is proposed to process those non-ideal PCC voltage. The power balance among utility, load and ShAPF while applying ANF is explained in details. The simulation results of SimpowerSystems tool have proved that the ANF successfully facilitates the ShAPF in terms of compensating unbalanced/distorted current of loads under even without an ideal voltage circumstance.