Modified pulse energy modulation technique of a three-switch buck-boost inverter

摘要

This paper proposed a modified pulse energy modulation (PEM) technique for a single-phase single-stage three-switch buck-boost inverter, solving the issue existed in practical applications that the requirement for sampling circuits is too high to achieve. The three-switch buck-boost inverter was investigated for both standalone and grid-connected operations. Simulation and experimental results verified that the newly proposed PEM technique enables the buck-boost inverter to transfer the demanded energy from a DC source to AC side and achieve a sinusoidal output current with low total harmonic distortion (THD). Therefore, it can be concluded that the proposed modified PEM technique is suited for buck-boost inverters in distributed generation systems, with lower requirement for the sampling circuits. The new contributions presented in this paper include advancing the PEM concept as an alternative to PWM for inverter modulations; and applying the proposed PEM technique to a low component-count inverter in standalone and grid-connected applications.