Comparison of two PWM techniques for a single-phase shunt active power filter applying indirect current control

This paper presents a comparison of two pulse width modulation PWM control techniques applied to regulate the current produced by a single phase shunt active power filter SPSAPF. An indirect current control strategy is implemented with standard S-PWM and modified M-PWM to compensate harmonics and reactive power of a non-linear load. The M-PWM control technique is based on two comparisons of a triangular high frequency carrier signal and the source fundamental current. This harmonic signal namely +/spl beta/ and its opposite value -/spl beta/ are used, at the same instant, in the comparison process to generate the gate signals for the semi-conductor devices. Using the averaging technique, the direct consequence of using this M-PWM technique is that the transfer function of the SPSAPF becomes a pure gain. Simulation and experimentation results are presented to verify the good behavior of the M-PWM. These results highlight the superior performance of M-PWM in terms of total harmonic distortion THD and reactive power compensation.