Researches On Reactive Power Optimization And Voltage Control In Ningbo Grid

Power industry is the foundational industry of national economy. With the rapid development of China's national economy, the scale of power grid expands rapidly. However, due to the unbalanced distribution of resources and some other factors, power plants distributed in grid are also unbalanced. Voltage quality problem is increasingly important, and becomes one of the major problems in power grid.The rudimentary study and research are carried out on the practical use of AVC system in Ningbo grid. Besides, further study on reactive power optimization is done. The optimal compensating allocation and no-load tap settings are presented, and the efficient optimization tool is discussed. The optimal compensation allocation is done by gathering reactive power loads of substation throughout the year to derive the optimal probability curve, and optimal cover method is used based on statistical optimization method. No-load tap changers are optimal set by multi-mode optimization. Algorithms are tested on Ningbo power grid.In the exploitation of AVC system in Ningbo grid, we found the disadvantage of primal dual interior point method and branch and bound method. This article describes principle of the primal dual interior point method and its lacks, branch and bound method and its improvement. And the mixed algorithm of primal dual interior point method and branch and bound is proposed, and is applied to Ningbo power grid. Test result shows that the mixed algorithm can meet the requirements of real-time automatic voltage control on completeness, reliability, efficiency, and global optimality. The proposed automatic voltage control system can actually play an important role in the power grid.