Improving power quality and active support: Optimal scheduling of wind-solar-storage system considering supercapacitors-based voltage drop optimization strategy

Abstract

As large-scale renewable energy sources such as wind and photovoltaic power are integrated into the power grid, the inertia level and disturbance rejection capability of the power system gradually decline, leading to increasingly severe voltage stability issues within the system. Therefore, this paper proposes a voltage drop loss optimization strategy based on supercapacitors to achieve active support and optimization of voltage drop loss reduction in the system, thereby enhancing the frequency regulation capability and operational stability of microgrid systems. First, supercapacitors are introduced into the microgrid system, and the locations of their integration and their switching capacities are optimized to realize active support and optimization of voltage drop loss reduction. Second, an improved Great Wall Construction Algorithm, enhanced by a chaotic weighted dynamic exploration optimization strategy, is proposed. This approach integrates nonlinear dynamics with a random walk model to bolster the randomness and mutation in the algorithm's search process, thus improving its global search capability and ability to escape local optimal solutions. The results demonstrate that the proposed strategy can effectively enhance power quality. Specifically, for a microgrid system composed of IEEE-33 nodes, the system voltage drop loss improves from −26.2778 to 9.3835, and the cost of purchasing electricity from external sources decreases by 14.53 %.