A Multilevel Inverter Structure Based on the Development of Full-Bridge Cells with the Minimum Number of Switches for Renewable Energy Applications
Document Type : Original Article
Authors
1 Electrical Engineering Department, Faculty of Technical and Engineering, Imam Khomeini International University, Qazvin, Iran
2 Electrical Engineering Department, Faculty of Technical and Engineering, Imam Khomeini International University, Qazvin, Iran.
Abstract
Because of the rise in electricity consumption, renewable energy sources such as the solar and wind are increasingly being used to generate electricity. The integration of renewable energy sources into the grid is critical to energy utilization. The major goal of the new proposed structures is to achieve high output voltage while using fewer power electronic elements such as switches, diodes, and DC input voltage sources, unlike conventional topologies. In addition to lowering costs, size, and complexity, reducing the number of switches and DC voltage sources improves inverter performance. This paper presents a general multilevel inverter based on full-bridge cells. Two specific cases of proposed topology are investigated in detail. The proposed structures have the advantage of reducing the power electronic elements and the switching complexity. It is also possible to configure asymmetric sources to achieve maximum output levels. The first special case is a synthesis with seventeen levels of output, four input voltage sources, and nine switches achieved to the Total Harmonic Distortion (THD) of output voltage equal to 5.68% in 100 HZ frequency of switching carriers and THD of output voltage equal to 6.69% for 5000 HZ frequency of switching carriers. The second case involves the synthesis of forty-three levels of output with six input voltage sources and twelve switches achieved to the THD of output voltage equal to 3.49% in 100 HZ frequency of switching carriers and THD of output voltage 3.99% for 5000 HZ frequency of switching carriers. The proposed topologies are switched using a multicarrier pulse width modulation method. When compared to conventional structures, two special cases of this general topology have significantly reduced the number of power electronic switches. Also, a comparison of the proposed topology with the other structures, results show that the proposed structure has optimally reduced the number of power elements.
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