基于拉格朗日对偶松弛的多区域柔性直流互联电网无功优化

现有方法对互联后的电网进行无功优化时难以满足大规模电网实时计算、快速反应的需要,并且面临全网数据收集的难题。为了解决上述问题,采用分解协调算法的思想,提出一种基于拉格朗日对偶松弛的多区域柔性直流互联电网无功优化方法。首先根据支路潮流模型,利用二阶锥松弛和二次旋转锥松弛方法建立了多区域柔性直流互联电网的集中式无功优化模型。然后利用拉格朗日对偶松弛理论在集中式优化模型的基础上,提出了可以并行计算的多区域柔性直流互联电网无功优化方法。通过算例计算,验证了所提算法的有效性和正确性。此外,还对比分析了所述的分解协调算法和基于交替方向乘子法(ADMM)的分布式优化算法的计算结果,证明所用算法在计算时间上更具优势。

Reactive Power Optimization in Multi-area VSC-HVDC Interconnected Power Grids Based on Lagrangian Dual Relaxation

The existing methods are difficult to meet the real-time calculation needs of large-scale power grid and quick response when performing reactive power optimization for the interconnected power grids, and also facing the problem of data collection throughout the whole network. To solve the problem, this paper uses the idea of decomposition-coordination algorithm and proposes a reactive power optimization method for multi-area voltage source converter based high voltage direct current(VSC-HVDC)interconnected power grid based on the Lagrangian dual relaxation theory. Firstly, according to branch power flow model, a centralized reactive power optimization model of multi-area VSC-HVDC interconnected power grids is established by using the second-order cone relaxation and rotated quadratic cone relaxation technology. Then, a reactive power optimization method is proposed based on decomposition-coordination algorithm for multi-area VSC-HVDC interconnected power grid based on the Lagrangian dual relaxation theory used in the centralized optimization model. The validity and correctness of proposed algorithm are verified by case study. Finally, the results from decomposition-coordination algorithm and alternating direction method of multipliers(ADMM)are compared, proving that the former one has an advantage on compution time.