摘要
在多送端直流系统的某直流线路发生闭锁故障后,为提高安稳控制的效率,需优先选取支援效果好的直流参与紧急功率支援。为定量评估各非故障直流对故障直流紧急功率支援的效果,将距离故障直流整流站电气距离最近的机组和距离故障直流逆变站电气距离最近的机组定义为关键机组对并给出了关键机组对的辨识方法,由该特定机组间的相对运动表征故障直流两端交流系统的暂态稳定性。再根据故障初期"关键机组对"的相对加速能量评估直流功率支援的效果,建立了多条直流相互间紧急功率支援的归一化评估指标。指标计算表明,直流功率支援的效果与送端电气距离的远近没有直接联系,而是送端电气距离、受端电气距离以及直流本身的可用支援容量3方面综合影响的结果。实际电网仿真表明,实际支援效果的排序与指标评估结果相一致,验证了所提指标的有效性。
When valve-blocking fault occurs in a certain DC line of HVDC transmission system with multiple sendings, to improve the efficiency of security and stability control it is necessary to preferentially choose the DC line with stronger supporting ability to take part in the emergency power support. To quantitatively assess the emergency power support effect of faulty DC line by trouble-free ones, a concept of key generator pair （KGP）, which is composed of the generator that is electrically most close to the converter station of the faulty DC line and the generator that is electrically most close to the inverter station of the faulty DC line, is defined and corresponding method to identify KGP is given, thus the transient stabilities of AC power systems connected to both ends of the fault DC line can be characterized by relative motion between the generators constituting KGP. The effect emergency mutual power support among multiple DC lines can be assessed by relative accelerating energy of KGP in the early stage of the fault, and the normalized assessment index of emergency mutual power support among multiple DC lines is established. Calculation results of the proposed assessment index show that there isno direct relation between the effect of mutual power support and the electrical distance of the sending end, and the effect of mutual power support is the synthesized results of electrical distance of sending end, electrical distance of receiving end and the available support capacity of DC lines. Simulation of actual power grid show that the ordering of actual support effect conforms to the assessment result Of the proposed index, therefore the validity of the proposed assessment index is verified.
出处
《电网技术》
EI
CSCD
北大核心
2013年第9期2416-2421,共6页
Power System Technology
基金
国家863高技术基金项目(2011AA05A119)
国家自然科学基金项目(51077103)
国家电网公司大电网重大专项资助项目课题(SGCC-MPLG029-2012)~~
关键词
评估指标
多送端直流
闭锁故障
紧急功率支援
暂态功角稳定
assessment index
HVDC system with multiple sending ends
DC block fault
emergency DC power support
transient angle stability
