Abstract: When the input DC voltage is high，considering the limited voltage endurance capability of the power

switch of the inverter，an input-series and output-parallel（ISOP）inverter topology was adopted，which is composed of two single-phase full-bridge inverter modules. The input DC voltage could be divided equally under the inputvoltage sharing control，so that the power switch could only bear half of the input DC voltage，and the output level quantity increases under the carrier phase shift sinusoidal pulse width modulation（SPWM）mode，which can reduce THD of the output voltage. In addition，the ISOP inverter and the active neutral point clamped（ANPC）three-level inverter were compared in terms of harmonics and scalability，and pointed out the superiority of the ISOP inverter.Finally，the simulation verification was carried out.

      Key words: input-series and output-paralle（l ISOP）；inverter；input-voltage sharing；carrier phase shift