Work

Optimal‐droop voltage‐restorer for zonal dc distribution system with simultaneous consideration of dynamic current balance and power loss reduction

Year: 2024

Type: article

Abstract: A dc voltage restorer (dc-VR) with optimal droop control is developed to reduce the power loss and solve the dynamic current imbalance simultaneously of zonal dc distribution system. Firstly, the power loss model composed of line loss and converter loss is built and it is proved to be a strictly convex function with respect to droop coefficients. Thus, an image-based droop optimization method is proposed to search for the optimal droop coefficients. Then, the economy of voltage compensation on power loss reduction is investigated and an ESS-combined dc-VR is designed, including an interleaved parallel architecture and a capacitor-integrated electric spring (C-ES). Unified virtual inertia is proposed for interleaved parallel bridge arms to make their dynamic performance consistent. And the new introduced C-ES can remain the bus voltage at the rated level to reduce the system cost. Therefore, the problem of dynamic currents imbalance is addressed from the points of converter structure and control system, and the power loss can be reduced by voltage recovery and optimizing the current reallocation which is achieve by updating sharing coefficients from the image-based droop optimization method. Finally, hardware in the loop experiment results prove the consistent dynamic characteristics of the dc-VR' arms.

Source: IET Power Electronics

DOI: 10.1049/pel2.12775