Interface Optimization Scheme Under Semi-Implicit Delay Decoupling Method

There exist various universal forms of semi-implicit delay decoupling. The semi-implicit delay decoupling within the state space scheme possesses second-order accuracy, yet the selected state variables must be mutually independent. When employing the nodal voltage method, the synchronization requirement of the nodal voltage method contradicts the delay characteristics of the non-semi-implicit delay-coupling model. To address this issue, a semi-implicit decoupling data interface enhancement algorithm was developed. In this paper, a semi-implicit decoupling model was constructed for the VSC converter, enabling the decoupling of the ac and dc terminals. On this basis, in accordance with the characteristics of the interface circuit, an exponential analytical solution was derived, and the interface algorithm was obtained by integrating with the decoupling model. Finally, the improved algorithm proposed herein was verified through digital examples. This algorithm improves the implicit decoupling method to a certain extent.