Open AccessTime‐domain characterisation of multicarrier‐based digital SPWM of multilevel VSI
Author(s) -
Kumar Mayank,
Gupta Rajesh
Publication year - 2018
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2017.0078
Subject(s) - total harmonic distortion , pulse width modulation , fundamental frequency , frequency domain , harmonic , sampling (signal processing) , control theory (sociology) , voltage , modulation (music) , electronic engineering , mathematics , engineering , physics , computer science , acoustics , telecommunications , electrical engineering , mathematical analysis , control (management) , artificial intelligence , detector
The effect of sampling frequency on digital sinusoidal pulse width modulated (SPWM) output of phase‐shifted carrier‐based multilevel voltage source inverter (VSI) and the characteristics of output voltage and load current has been discussed here. The generalised equation of digitally controlled phase‐shifted carrier‐based multilevel VSI output voltage is derived using double Fourier integral solution. The Jacobi–Anger expansion has been used to obtain the integral solution. Time‐domain analysis has been used to establish the relation between sampling frequency, carrier frequency, and fundamental frequency, at different modulation indices for n ‐level VSI. The load current of VSI is stepped in nature due to stepped variation in the output of the digital SPWM. Therefore, the low‐frequency harmonic components closer to the fundamental frequency appear in the frequency spectrum. The variation of total harmonic distortion with respect to multisampling factor (sampling to carrier frequency ratio) has been discussed at different modulation indices for multicarrier‐based multilevel inverter. The analytical results are verified through simulation and laboratory experimental results.