An Improved Approach for AC-DC Power Flow Calculation With Multi-Infeed DC Systems
An Improved Approach for AC-DC Power Flow Calculation With Multi-Infeed DC Systems
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DOI：
10.1109/tpwrs.2010.2068579
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发表时间：
2011-05
影响因子：
6.6
通讯作者：
Chongru Liu;Boming Zhang;Yunhe Hou;Felix F. Wu;Yingshang Liu
中科院分区：
文献类型：
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作者：
Chongru Liu;Boming Zhang;Yunhe Hou;Felix F. Wu;Yingshang Liu
本文提出了一种基于顺序法的改进的交直流潮流计算方法。该方法解决了直流子系统潮流计算过程中交流母线电压违规引起的收敛问题。通过灵活调整换流变压器抽头位置，可以显着提高收敛性能。为了灵活调整换流变压器的抽头位置，主要提出了三点改进方案。首先，将整个直流系统的方程解耦为各个直流系统，以便轻松找出哪个直流系统的分接位置需要调整。其次，必要时选择换流变压器的抽头比作为替代状态变量来代替控制角的余弦。第三，采用Newton-Raphson方法来求解直流子系统，而不是使用线性方程组的方法。此外，还对所提出方法的优点进行了理论分析。数值模拟和实际应用表明，该方法满足不同系统运行条件的要求，在收敛性和速度方面具有优势。所提出的方法已成功集成到中国南方电网的能源管理系统（EMS）中。
An improved approach based on sequential method for the AC-DC power flow calculation is proposed in this paper. This approach solves the convergence problem caused by voltage violations at AC buses during the power flow calculation for the DC subsystems. The convergence property can be significantly improved by adjusting the converter transformer tap position flexibly. In order to adjust the tap position of the converter transformer flexibly, three mainly modifications are proposed. Firstly, the equations for whole DC systems are decoupled into individual DC systems so as to easily figure out which DC system's tap position needs adjustment. Secondly, the tap ratio of a converter transformer is selected as an alternative state variable to replace the cosine of the control angle when necessary. Thirdly, the Newton-Raphson method is utilized to solve DC subsystems instead of the method using the linear equations. Furthermore, a theoretical analysis of the advantages of the proposed approach is also presented. Numerical simulations and practical applications show that the proposed approach meet the requirement of different system operating conditions and has advantages in terms of convergence and speed. The proposed approach has been successfully integrated into the Energy Management System (EMS) for China Southern Power Grid.