多馈入交直流系统有效短路比的影响因素分析

Influencing Factors Analysis Upon Effective Short-circuit Ratio of Multi-infeed AC/DC System

交直流输电已经成为了我国电网发展的必要手段,由于多馈入交直流系统的强复杂性使得评估交直流系统间的相互作用变得非常困难。多馈入有效短路比不仅能够评估交流系统的强弱,而且还能反映直流系统间的相互作用,是多碛入直流系统规划中的一种重要参考指标。分析了直流功率、直流落点间的联络阻抗、线路阻抗、交流滤波器和无功补偿器的等值导纳等因素对多馈入有效短路比的影响及变化规律,通过两馈入交直流系统的分析结果验证了各个因素对多馈入有效短路比影响及变化规律的正确性。

AC /DC transmission has become the necessary means to develop the power grid in China. Because of the strong complexity of the multi-infeed AC/DC system, it is very＂ difficult to evaluate the interaction between the AC and DC systems. The multi-infeed effective short circuit ratio can not only evaluate the strength of AC system, but also reflect the interaction between DC systems,so it is an important reference index in the construction of muhi-infeed HVDC power System. In this paper,tiLe effect ＆ change rule of MESCR are analyzed in the light of the factors, such as DC power,the impedance of contact group between the DC drop points, the impedance of the line,the equivalent admittance of AC filter and reactive power compensation. The test results of the two-infeed AC/DC system verify the correctness of the above-mentioned conclusions.