Harmonics Minimization in MLI Using Grasshopper Optimization Algorithm

ABSTRACT

This paper proposes the use of a nature-inspired algorithm known as Grasshopper Optimisation Algorithm for optimising switching angles applied to a three-phase 7-level cascaded H-bridge multilevel inverter. Switching angles obtained using the algorithm can be used to synthesise an optimised output voltage waveform with desired fundamental component and minimised 5th and 7th order harmonics. Simulation results show that the algorithm is able to provide switching angles over a wider modulation index range than Newton Raphson technique and is capable of minimising the objective function better than Genetic Algorithm. MATLAB/Simulink-PSIM dynamic co-simulation performed on a three-phase 7-level cascaded H-bridge multilevel inverter operated using GOA derived switching angles is able to respond to varying modulation index demand and produce the output voltage waveform with the desired fundamental component and minimised selected 5th and 7th order harmonics. Both simulation and experimental results obtained from the three-phase 7-level cascaded H-bridge multilevel inverter show good agreement, confirming the validity of the switching angles obtained using the Grasshopper Optimisation Algorithm.

KEYWORDS:

• Cascaded H-bridge multilevel inverter
• selective harmonic minimisation
• pulse width modulation
• total harmonic distortion
• grasshopper optimisation algorithm

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Ministry of Higher Education Malaysia through the Fundamental Research Grant Scheme [FRGS/1/2020/TK0/UNIMAP/02/54].