The single-leg integrated split-source inverter exhibits attractive features for distributed photovoltaic power generation systems

including reduced component count

single-stage high step-up inversion capability

and elimination of electrolytic capacitors. However

under conventional PFM+SPWM control

the output voltage demonstrates bipolar pulse characteristics

and the boost-leg switching frequency fs1 varies significantly with load conditions. Therefore

the harmonic content becomes abundant

the total harmonic distortion (THD) is elevated

the output filter inductance requirements are increased

the frequency spectra shift

and the light-load efficiency is reduced. To address these limitations

this paper proposes a hybrid control strategy integrating variable inductance with SPWM. In the strategy

both legs employ identical fixed-frequency carriers with the boost-arm maintaining a constant 0.5 duty cycle while regulating DC-link voltage through variable inductance adjustment

whereas the inverter-leg retains SPWM control for output voltage regulation. By the strategy

the output voltage is transformed into unipolar pulses

the spectral distribution is stabilized against load variations

the odd-order harmonics of fs1 is eliminated

and the maximum harmonic amplitude is halved. Consequently

THD reduction

50% decrease in output filter inductance

and improved light-load efficiency are achieved. Comprehensive simulation and experimental results based on a 500 W prototype validate the proposed strategy.