Control of a Three-Phase Cascaded H-Bridge Multilevel Inverter for Solar Energy Injection

Abstract

CHB multilevel converters play a role for optimising the use of solar electricity as they allow a more efficient energy conversion. In this work, a classic control of a CHB multilevel inverter for PV energy injection is developed, considering grid disturbance compensation and an MPPT strategy for maximising PV energy. In order to prove the proposed control scheme, simulations in MATLAB/Simulink are carried out. The current control strategy, the dc voltage control, and the MPPT controller proved proper steady state operation and proper response in front of external disturbances. Additionally, the inclusion of a dynamic decoupler for the inverters output current control proved to be useful tool for controlling multilevel converters. Thus, solar energy injection to the grid can be maximised using the proposed 7-level CHB multilevel inverter.