A carrier-based improved synchronized discontinuous pulse width modulation（ISDPWM） without a two-level voltage jump for the three-level inverter was proposed. Aiming at the defect of two-level voltage jump in traditional SDPWM

the design principle of ISDPWM switching sequence with phase voltage satisfying three-phase symmetry

half-wave symmetry

no two-level voltage jump and three-phase device simultaneous action was firstly analyzed. On this basis

ISDPWM I/II/III/IV which solves the traditional SDPWM defect and ISDPWM A/B/C/D/E/F/G which utilizes the zero level clamping state were designed

and the switching frequency of each ISDPWM was analyzed. By comparing the weighted total harmonic distortion（WTHD） values of each ISDPWM

the WTHD optimal ISDPWM was further obtained. To realize the ISDPWM switching sequence more conveniently

this paper studied the modulation wave and carrier corresponding to each ISDPWM

and proposed carrier-based ISDPWM. Finally

the validity of carrier-based ISDPWM was verified by simulation and experiment

and the results show that it can eliminate even harmonics and triple harmonics without a two-level voltage jump

and its calculation is simple and easy to implement.