In this paper, a generalized non-active power theory based control strategy is implemented in a 3-phase 4-wire combined series-parallel active filter (CSPAF) system for periodic and non-periodic waveforms compensation. The CSPAF system consists of a series active filter (SAF) and a parallel active filter (PAF) combination connected a common dc-link. The generalized non-active power theory is valid for single-phase and multi-phase systems, as well as periodic and non-periodic waveforms. The theory was applied in previous studies for current control in the PAF. In this study the theory is used for current and voltage control in the CSPAF system. The CSPAF system is simulated in Matlab/Simulink and an experimental setup is also built, so that different cases can be studied in simulations or experiments. The simulation and experimental results verify that the generalized non-active power theory is suitable for periodic and non-periodic current and voltage waveforms compensation in the CSPAF system.