Experimental validation of new self-voltage balanced 9L-ANPC inverter for photovoltaic applications

M Jagabar Sathik,Marif Daula Siddique,Dhafer J Almakhles,N Sandeep

doi:10.1038/s41598-021-84531-z

Abstract

Multilevel inverters play an important role in extracting the power from renewable energy resources and delivering the output voltage with high quality to the load. This paper proposes a new single-stage switched capacitor nine-level inverter, which comprises an improved T-type inverter, auxiliary switch, and switched cell unit. The proposed topology effectively reduces the DC-link capacitor voltage and exhibits superior performance over recently switched-capacitor inverter topologies in terms of the number of power components and blocking voltage of the switches. A level-shifted multilevel pulse width modulation scheme with a modified triangular carrier wave is implemented to produce a high-quality stepped output voltage waveform with low switching frequency. The proposed nine-level inverter’s effectiveness, driven by the recommended modulation technique, is experimentally verified under varying load conditions. The power loss and efficiency for the proposed nine-level inverter are thoroughly discussed with different loads.

Highlights

Abbreviations neutral point clamp (NPC) Neutral point clamped multilevel inverters (MLIs) Multilevel inverter Vin Input voltage Vout, Vo Output voltage M Modulation index maximum blocking voltage (MBV) Maximum blocking voltage TBV Total blocking voltage Ts Carrier signal time interval dq Change of amplitude of carrier signals ΔQ Change of charge θ1.... θ4 Switching angle Amn, Bmn Coefficients of Fourier expansion Aoo, Boo DC offset component of the pulse width-modulated waveform VCarr Carrier signal Vref Reference signals of fundamental frequency ff Fundamental frequency
The active neutral point clamped (ANPC) inverter topology is widely used for induction motor drive or AC grid-connected applications
This paper successfully develops a 9L-ANPC topology to overcome the drawbacks of the existing topologies with low voltage rating components devised

Summary

Introduction

Abbreviations NPC Neutral point clamped MLI Multilevel inverter Vin Input voltage Vout, Vo Output voltage M Modulation index MBV Maximum blocking voltage TBV Total blocking voltage Ts Carrier signal time interval dq Change of amplitude of carrier signals ΔQ Change of charge θ1.... θ4 Switching angle Amn, Bmn Coefficients of Fourier expansion Aoo, Boo DC offset component of the pulse width-modulated waveform VCarr Carrier signal Vref Reference signals of fundamental frequency ff Fundamental frequency.

Results

Conclusion