Neutral point clamped based active power filter for power quality improvement

In this paper, we revise new kind of continuous-alternating converter, a seven-level neutral point clamping (NPC) voltage source inverter (VSI). We intend this inverter for applications in high voltage and high power fields. In the foremost part, we develop the knowledge and the control models of this inverter using the connections functions of the semi-conductors. After that, we present pulse width modulation (PWM) to control this converter using its control model. Active power filter continues to draw considerable attention. Because of sensitivity of consumers on power quality and advancement in power electronics. Active power filter technology is the most efficient way to compensate reactive power and cancel out low order harmonics generated by nonlinear loads. An active power filter is a device that is connected in parallel to and cancels the harmonic currents from the group of nonlinear loads so that the resulting total current drawn from the ac main is sinusoidal. The shunt active power filter was considered to be the most basic configuration for the APF. The proposed NPC based APF is tested its performance under balanced non-linear load, Un-balanced non-linear load and variable non-linear load with the source current harmonic analysis by using Matlab/Simulink software.