In response to the problem of unbalanced output power of cascaded H-bridge（CHB） units under the carrier disposition（CD） modulation strategy of the cascaded H-bridge multi-level inverter

and the problem of the high total harmonic distortion（THD） of line voltage under the carrier phase shift pulse width modulation（CPS-PWM） modulation strategy

we proposed a hybrid multi-carrier pulse width modulation strategy based on power balance. In this strategy

a carrier period of in-phase disposition pulse width modulation（IPD-PWM） strategy is taken as the basic unit

and the arrangement of triangular carriers in the vertical direction is changed through periodic cycling

thus the power balance of H-bridge units in the full modulation ratio range as CPS-SPWM strategy is realized. Meanwhile

when the output voltage waveform of IPD-PWM is unchanged

the harmonic spectrum of the output voltage is ensured to be identical with that of the IPD-PWM strategy

which effectively improves the harmonic performance of the output line voltage of the inverters

thus the problems of unbalanced output power and high THD of the interconnection units at all levels can be solved. Finally

the correctness of the strategy is verified by simulation and experimental results.