A Single-Phase Cascaded Multilevel Inverter Based on a New Basic Unit With Reduced Number of Power Switches

2015 ◽  
Vol 62 (2) ◽  
pp. 922-929 ◽  
Author(s):  
Ebrahim Babaei ◽  
Sara Laali ◽  
Zahra Bayat
Keyword(s):  
Single Phase ◽  
Multilevel Inverter ◽  
Basic Unit ◽  
Power Switches ◽  
Cascaded Multilevel Inverter

Switching Modulation Strategies for Multilevel Inverter

2021 ◽  
Vol 20 (2) ◽  
pp. 1-7
Author(s):  
Jahanzeb - ◽  
Shahrin Md. Ayob ◽  
Saifullah Khan ◽  
Mohd Zaki Daud ◽  
Razman Ayop
Keyword(s):  
Single Phase ◽  
Multilevel Inverter ◽  
Level Control ◽  
Multilevel Inverters ◽  
Power Switches ◽  
Modulation Schemes ◽  
Multicarrier Pwm

There is always a need to create efficient and optimized converters to deliver the best possible results to achieve a better THD profile in the waveform output. One way is by controlling the switching of the power switches of the converters using appropriate modulation schemes. While numerous works have been done in proposing new switching modulation strategies for multilevel inverters, this work will compare multicarrier PWM and near-to-level control (NLC) modulation schemes. In this paper, multicarrier PWM variants, namely, PD-PWM, POD-PWM, and APOD-PWM, are designed and simulated. Their voltage THD and spectrum performance are discussed when applied to single-phase 7, 9, and 11-level cascaded multilevel inverters. Then NLC modulation will be designed and applied to similar multilevel inverter circuits. It will be shown that the NLC exhibits some superior performances compared to PWM-based but with several drawbacks that can be optimized. 

Single-Phase Multilevel Inverter with Simpler Basic Unit Cells for Photovoltaic Power Generation

2016 ◽  
Vol 7 (4) ◽  
pp. 1233 ◽  
Author(s):  
M. S. Chye ◽  
J. A. Soo ◽  
Y. C. Tan ◽  
M. Aizuddin ◽  
S. Lee ◽  
...  
Keyword(s):  
Power Generation ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Basic Unit ◽  
Scanning Method ◽  
Power Mosfets ◽  
Switching Losses ◽  
Ac Power ◽  
Unit Cells

This paper presents a single-phase multilevel inverter (MLI) with simpler basic unit cells. The proposed MLI is able to operate in two modes, i.e. charge mode to charge the batteries, and inverter mode to supply AC power to load, and therefore, it is inherently suitable for photovoltaic (PV) power generation applications. The proposed MLI requires lower number of power MOSFETs and gate driver units, which will translate into higher cost saving and better system reliability. The power MOSFETs in the basic unit cells and H-bridge module are switched at near fundamental frequency, i.e. 100 Hz and 50 Hz, respectively, resulting in lower switching losses. For low total harmonic distortion (THD) operation, a deep scanning method is employed to calculate the switching angles of the MLI. The lowest THD obtained is 8.91% at modulation index of 0.82. The performance of the proposed MLI (9-level) has been simulated and evaluated experimentally. The simulation and experimental results are in good agreement and this confirms that the proposed MLI is able to produce an AC output voltage with low THD.

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