Evaluation of CHB MLI based shunt APF using low pass filter and self-tuning filter

The increasing demand for high-rating power supply in the distribution system causes conventional inverter topology, six step voltage source (SSVSI) unsuitable being applied as active filter (APF). Multilevel (MLI) is generally best suitable APF, but not all types of MLI can be used high-voltage applications. Among MLIs cascaded H-bridge (CHB) choice since it produce output more than twice amount DC source. Moreover, CHB topology uses fewer devices and simple design. Low pass (LPF) a common method harmonic extraction this controller. However, faces various problems, such an additional need phase lock loop (PLL) algorithm slow transient steady-state responses. Therefore, self-tuning (STF) introduced new filtering to overcome problem. This paper evaluates MLI's performance APF using STF extraction. model was developed verified MATLAB/Simulink. results show that performs better total distortion (THD) LPF. Nevertheless, both algorithms THD below 5%, defined permissible value stated IEEE 519.