Amplitude slicing PWM. - Phase interleaving PWM. Spectral ... Amplitude Slicing and Phase Interleaving. 11/15 ... Number of averages for PSD: Oversampling of ...
Analytical Description of Multilevel Carrier-Based PWM of Arbitrary Bounded Input Signals Harald Enzinger, Christian Vogel Telecommunications Research Center Vienna (FTW), Austria
IEEE International Symposium on Circuits and Systems 2014 Melbourne, Australia
Introduction Pulse Width Modulation (PWM) •
1/15
Efficient signal generation - Power electronics - Audio - Communications
Introduction Carrier-based PWM • •
2/15
Simple implementation Basis for most PWM modulators
Introduction Multilevel carrier-based PWM • •
3/15
Less distortion Lower switching voltage
Problem Statement Analytical description of carrier-based PWM - Arbitrary input signal - Arbitrary number of levels - Arbitrary carrier configurations
Relevance - Spectral analysis - Comparison of existing modulation schemes - Insight for research on new modulation schemes
4/15
State of the Art Black, 1953 - Double Fourier series
Song, 2003 - Combination of pulse spectra
Hausmair, 2013 - Partial Fourier series
5/15
Many carrier configurations Extension to multilevel Single tone input signal Arbitrary input signals Many carrier configurations Not well suited for multilevel
Arbitrary input signals Extension to multilevel Specific carrier configuration
Contributions Generalization of Hausmair 2013 - Arbitrary input signals - Arbitrary number of levels - Arbitrary carrier configurations
Unified Description for M-Level Amplitude Slicing and Phase Interleaving Fourier series
Harmonic amplitude distortion
11/15
Spectral Analysis Conventional numerical approach - Time-domain simulation - FFT analysis of PWM signal Very high oversampling No insight into cause of distortion
Proposed analytical/numerical approach - Analytical description - FFT analysis for each harmonic Only moderate oversampling Insight into the cause of distortion
12/15
Spectral Analysis Multitone input signal
Oversampling of PWM: Oversampling of simulation: Number of averages for PSD: 13/15
Spectral Analysis Comparison of number of levels
14/15
Amplitude distortion:
Summary Analytical description of carrier-based PWM - Arbitrary input signals - Arbitrary number of levels - Arbitrary carrier configurations
Examples - Amplitude slicing - Phase interleaving
Spectral analysis - Less computation - More insight