Design and analysis of single phase pure sine inverter based on phase locked loop

This article proposes the new technique of the PWM oscillation based on phase locked loop that controls the inverter. The PWM works together with push-pull where it is connected to the step-up transformer. The advantages of proposed technique are that the PWM circuit is non-complicated of structure and that the PWM circuit can prevent from a noise signal. In addition, a carrier frequency can be adjusted at a frequency running with the VCO of a phase locked loop. The PWM output which is obtained from the push-pull inverter has high symmetry voltage. Ultimately, the PWM is passed through the LC low pass filter where high pure sine wave signal occurs. As a result, the total harmonic distortion (THD) is decreased which is equal to 2.27%. Due to the related proposed technique, the output voltage regulation is improved and the dynamic response ofa step load change is also improved.