Non-iterative Wide-modulation-index Switching-angle Calculation Techniques for 15-level Binary Cascaded H-bridge Multilevel Inverter

Abstract

Cascaded H-bridge multilevel inverter (CHBMI) is able to generate a staircase AC output voltage with low switching losses. The switching angles applied to the CHBMI have to be calculated and arranged properly in order to minimize the total harmonic distortion (THD) of the output voltage waveform. In this paper, two non-iterative switching-angle calculation techniques applied for a 15-level binary asymmetric CHBMI are proposed. Both techniques employ a geometric approach to estimate the switching angles, and therefore, the generated equations can be solved directly without iterations, which are usually time-consuming and challenging to be implemented in real-time. Apart from this, both techniques are also able to calculate the switching angles for a wide range of modulation index. The proposed calculation techniques have been validated via MATLAB simulation and experiment. Keyword:Asymmetric multilevel inverter Binary multilevel inverter Cascaded H-Bridge Multilevel inverter Non-Iterative

Analysis of coupled and decoupled PWM techniques for induction motor drive

“…The switching states of inverter-I and inverter-II synthesizes a reference voltages of magnitude OA (VRef1) and O'A'(VRef2) instantaneously with the nearest vectors in all the six sectors. Using these individual two-level reference voltage vectors the three-level reference voltage vector can be expressed as in (5). If both inverters are operated with same switching states then the resultant reference voltage vector magnitude will be zero.…”

Analysis of coupled and decoupled PWM techniques for induction motor drive

“…The switching states of inverter-I and inverter-II synthesizes a reference voltages of magnitude OA (VRef1) and O'A'(VRef2) instantaneously with the nearest vectors in all the six sectors. Using these individual two-level reference voltage vectors the three-level reference voltage vector can be expressed as in (5).…”