直流输电单元运行模式等效的交直流电网潮流算法

A Power Flow Algorithm for AC-DC Power Grid Based on Equivalence Among Operation Modes of DC Transmission Unit

针对交直流混合电网潮流计算过程中直流输电单元多种运行模式引起的计算格式不固定问题,依据直流输电单元运行模式间所存在的相通性,将直流输电单元多种运行模式转化为同一种等效运行模式,该等效运行模式易于同交流潮流计算算法衔接,其微增模型的追加格式固定且不改变雅可比矩阵的稀疏对称结构,对传统交流潮流求解格式无影响,因而可很好地继承和兼容传统的交流潮流算法。通过对修改的电力科学研究院22节点算例的计算,验证了该方法的正确性和有效性。

In allusion to unset computation format caused by operation modes of DC transmission unit during the power flow calculation of AC-DC power grid, based on the equivalence among all operation modes these modes are converted to an equivalent mode. Such an equivalent operation mode is convenient to link up with AC power flow algorithm. In the equivalent mode the format of the micro-increment model added into correction equations is constant and the Jacobian matrix can remain its sparse symmetric structure, so the proposed method does not affect traditional format to solve AC power flow and the proposed method can be compatible with excellent AC power flow algorithm. The correctness and effectiveness of the proposed method are verified by simulation results of CEPRI 22-bus system, in which an AC branch is replaced by a DC transmission unit.