A Carrier-Based Synchronized 3 Integer Multiples SVPWM Algorithm for Three-level Inverter with Symmetrical Waveforms

In this paper, the principle of the synchronized 3 integer multiples SVPWM (S3MSVM) which can make the phase voltage pulse number be an integer multiple of 3 is introduced. Then the equivalent relationship between carrier-based PWM (CBPWM) and S3MSVM in different modulation index regions is derived. On this basis, a carrier-based S3MSVM (CBS3MSVM) is proposed by comparing the carrier with the single modulation wave or double modulation wave at each sampling point. CBS3MSVM can make the voltage waveform satisfies three-phase symmetry (TPS), half-wave symmetry (HWS), and quarter waveform symmetry (QWS), it optimizes the harmonic performance of the voltage and its calculation is simpler than S3MSVM. The correctness of the theoretical analysis is verified by simulation results.