Digital Twin System of Capacitive DC Bank Considering the Electrothermal Coupling Effect

Due to the frequency and temperature characteristics of the DC bank capacitor, the electrical and thermal stress of the capacitor are coupled. This paper proposes a digital twin modeling method that considered the electro-thermal coupling effect for the capacitive DC bank. Firstly, the physical models of the DC bank are summarized and the electro-thermal characteristic models have been built. With the physical and characteristic models, a six-part digital twin model has been constructed for the DC bank capacitors. An iterative process has been added in the model to reflect the electro-thermal coupling relationships. This process has been solved by the Newton-Raphson method. The accuracy of the proposed model has been verified by the finite element (FEM) simulation and experiment.