In this paper, a new combined cascaded multilevel inverter with reduced number of switches and DC voltage sources which is formed by series connection of same units with developed H-Bridge is proposed. For the purpose of generating all even and odd voltage levels 5 algorithms to determine the magnitudes of DC voltage sources is proposed. In order to investigate the advantages and disadvantages of the proposed combined cascaded multilevel inverter the proposed algorithms are compared to presented topologies from different points of view. The experimental results of the proposed topology are stated to check and verifying the performance of the proposed topology.
- Multilevel inverter
- Cascaded multilevel inverter
- Combined topology
- Developed H-Bridge
Fig. 1. Basic topology of proposed multilevel inverter.
EXPECTED SIMULATION RESULTS:
Fig. 2. Experimental results; (a) output voltage; (b) output voltage and current; (c) generated voltage levels by right side; (d) generated voltage levels by left side; (e) generated voltage levels by L,1 u ; (f) voltage across R2,2 S ; (g) voltage across 1 T ; (h) voltage across 3 T ; (i) voltage across a T .
In this paper, a new combined cascaded multilevel inverter has been proposed. After that, five different algorithms are proposed in order to determine the magnitudes of the DC voltage sources. By comparing these algorithms, it was concluded that the algorithm which generates a high number of voltage levels with less number of switches and DC voltage sources is better than other algorithms. According to this comparison, it was found that the fifth proposed algorithm is better among the proposed algorithms. In order to prove the claim about reduction of the number of IGBTs and DC voltage sources in the proposed topology, this topology was compared to presented topologies from different aspects. In these comparisons, it was found that the proposed topology generates 31 voltage levels with 14 IGBTs while presented topologies in ,  and  generate the same number of voltage levels with 32, 16 and 34 IGBTs, respectively. Also, it was found that this number of voltage levels needs 4 DC voltage sources, whereas, the topologies which presented in  and  generate 17 and 9 voltage levels with the same number of DC voltage sources. Afterwards, correctness of performance of the proposed topology and relations have been verified through experimentation of the proposed topology with 2 input units in each side.
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