Review of Reduced Switch-Count Power Cells for Regenerative Cascaded H-Bridge Motor Drives

 Abstract

Reduced Switch Cascaded H-Bridge (CHB) topology is one of the attractive topologies in high-power medium voltage motor drive applications due to its modularity and scalability. Research in high power regenerative motor drives has gained significant attention with the increasing demand for efficient energy use. In a cascaded H-Bridge (CHB) converter, the regenerative capability can be introduced by replacing diode front end (DFE) with active front end (AFE) topologies. However, this results in a huge increase in the number of power semiconductors, gate drivers, and heat sink size and thus increases the overall size and cost of the regenerative CHB motor drives. To overcome the aforementioned challenges, different power cell designs have been introduced to reduce the switch count, allowing the design of more suitable-sized and more economical drives. This paper comprehensively reviews the reduced switch-count power cell designs, including single-phase and three-phase grid connections. Each reduced switch-count cell design is analyzed, and its advantages and disadvantages are studied in detail. The challenges that arise with each design and the method to address the challenges are discussed.

Keywords

Cascaded H-bridge (CHB), reduced switch-count, control, motor drives, active front end, multilevel converter.

Proposed Diagram:

Figure 1. Multilevel Inverters Classification.

Expected Simulation Results:

Figure 2. Dc-Capacitors And Dc-Link Voltages For Semi-Reduced Cell Shown In [12].

Figure 3. Semi-Reduced Cell Input Current With 50 Hz Input Frequency And 20 Hz Output Frequency As Shown In [12].

Figure 4. Primary Input Current Using Fig. 14 Interconnection As Shown In [12].

Figure 5. Reduced Cell Input Current For 50 Hz Grid Frequency And 20 Hz Output Frequency, As Shown In [67].

Figure 6. Reduced Cell Primary Input Current As Shown In [67].

Figure 7. Input Primary Current As Resulted From [71] Experimental Results.

Conclusion

This paper presented a comprehensive review of the existing single-phase and three-phase reduced switch-count power cell designs for the regenerative Cascaded H-Bridge motor drives applications. Each power cell design is evaluated against the conventional 10-switch regenerative power cell to determine the advantages and disadvantages regarding structure, control, and harmonics present in the system. The key characteristics of the power cells are summarized to identify the requirements and differences between all regenerative power cells presented in this paper. Additionally, a new possible configuration is proposed to reduce the existing three phase reduced switch-count power cell.

References

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