Multilevel inverter is an effective and practical solution for increasing power demand and reducing harmonics of ac waveforms. Such inverters synthesize a desired output voltage from several levels of dc voltages as inputs. This paper analyzes the performance of five level cascaded H-bridge multilevel inverter with reduce number of power switches. Further by reducing switches and increasing level will reduce filter cost & harmonic content. 5- Level cascaded H-bridge asymmetrical multilevel inverter topology requires 8 switches but in this new multilevel inverter it requires 6 switches in which same multilevel is obtained. Invariably switching losses and cost also reduced. In this paper only multilevel inverter circuitry will be studied. The performance has been analyzed by the MATLAB/Simulink.
- Cascaded multilevel inverter
Figure 1: Circuit diagram of 5-level CHB MLI with reduced switches & dc sources.
EXPECTED SIMULATION RESULTS:
Figure 2: Output waveform of 5-levels single phase symmetric CHB MLI.
Figure 3: 5-levels THD in MATLAB tool.
This paper showed that this modified multilevel inverter topology with reduced number of switches can be implemented for industrial drive applications. This multilevel inverter structure and its basic operations have been analyzed. A detailed procedure for calculating required voltage level on each stage has been analyzed. As conventional five-level inverter involves eight switches, it increases switching losses; cost and circuit complexity. This 5-level inverter engages only six switches which reduces switching losses, cost and circuit complexity. Moreover it effectively reduces lower order harmonics. Therefore effective reduction of total harmonics distortion is achieved.
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