TY  - EJOU
AU  - Zhao, Feng 
AU  - Xu, Haonan 
AU  - Chen, Xiaoqiang 
AU  - Wang, Ying 

TI  - Power Balance Control Strategy of Cascaded H-Bridge Multilevel Inverter Based on Improved Harmonic Injection
T2  - Energy Engineering

PY  - 2025
VL  - 122
IS  - 12
SN  - 1546-0118

AB  - The cascaded H-bridge (CHB) multilevel inverter has become one of the most widely used PV inverter topologies due to its high voltage processing capability and high quality output power. Grid-connected PV system due to external conditions such as PV panel shading, PV component damage, can lead to PV output power imbalance, triggering the system over-modulation phenomenon, which in turn leads to grid-connected current waveform distortion. To this end, an improved power balance control strategy is proposed in this paper. Firstly, according to the different modulation ratios of each H-bridge module, a suitable harmonic injection method is used to keep the peak value of the modulating waveform always at 1; then an inverse triangular trapezoidal waveform is injected to optimize the modulating waveform, which further improves the output voltage waveform, reduces the THD value of the grid-connected currents, and maintains the stability of power inside the CHB system. Purpose. Simulation verifies the effectiveness and feasibility of this power balance control strategy.
KW  - Cascaded H-bridge inverter; harmonic injection; inverse triangular trapezoidal waveform; power balance control

DO  - 10.32604/ee.2025.068714