SELECTIVE HARMONIC ELIMINATION NON-SYMMETRICAL BIPOLAR PULSE WIDTH MODULATION TECHNIQUE: ANALYSIS AND EXPERIMENTAL VERIFICATION

摘要

Selective harmonic elimination pulse width modulation (SHE-PWM) techniques offer a tight control of the harmonic spectrum of a given voltage waveform generated by a power electronic converter along with a low number of switching transitions. These optimal switching transitions can be calculated through Fourier theory, and for a number of years quarter-wave and half-wave symmetries have been assumed when formulating the problem. It is shown recently that symmetry requirements can be relaxed as a constraint. This changes the way the problem is formulated and different solutions can be found without a compromise. This paper reports solutions to the switching transitions of a bipolar SHE-PWM when both the quarter- and half-wave symmetries are abolished. Selected simulation and experimental results are reported to show the effectiveness of the proposed method.