Digital Twin Modeling and Multiparameter Monitoring Schemes of Three-Level ANPC Inverters

Reliability of the key components is crucial for power electronic systems. Digital twin technique that has received increasing attention, provides an innovative solution for high-efficient, noninvasive, and reliable condition monitoring of power converters. This article aims to introduce such an emerging technique to power converters for parameter monitoring, and first presents a digital-twin modeling method for three-phase three-level active-NPC (3L-ANPC) inverters. To this aim, a digital twin model including the key parameters of 3L-ANPC inverters is proposed. Second, according to the external behaviors of the actual physical circuit and the digital twin model, combined with the parameter degradation characteristics, the corresponding objective evaluation function is designed and constructed. Then, the improved particle swarm optimization algorithm is used to update and iterate the key parameters and optimize the model, so as to narrow the gap between the twin model and the actual circuit. The key parameters monitoring of 3L-ANPC inverters is achieved. Finally, a three-phase three-level ANPC inverter experimental platform is established, and the effectiveness of this proposed method and the accuracy of parameter monitoring are verified by experimental results.