基于暂态电压稳定性新指标的自适应紧急减载方案  

An Adaptive Load Shedding Scheme Based on a Novel Index of Transient Voltage Stability

作　　者：李晔[1] 张保会[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049

出　　处：《智能电网》2016年第1期7-12,共6页Smart Grid

摘　　要：频率和电压响应在大扰动后相互耦合,传统的低频、低压减载方案相互独立,未充分考虑电压的时空分布特性和感应电动机对系统稳定性的影响。从2节点系统出发,分析感应电动机转差率偏差值对负荷稳定性和暂态电压稳定性的影响,提出综合考虑感应电动机转差率偏差值和负荷母线电压跌落幅度的暂态电压失稳程度新指标;并基于广域信息条件,利用新指标选择切负荷地点,确定相应控制量以构建新的紧急切负荷方案。该方案利用新指标更加全面地衡量了系统暂态电压稳定程度,具有全网切负荷和局部切负荷两种控制模式。通过IEEE 39节点系统的仿真,验证所提出自适应方案在保障系统大扰动后频率和电压稳定性方面相对于经典控制方案的有效性和优越性。Voltages and frequencies have mutual influences after large disturbance. The conventional under-voltage load shedding（UVLS） and under-frequency load shedding（UFLS） are adjusted respectively without full considerations on the time-space distribution character of voltages and the influences of induction motors on the system stability. From the two-node equivalent model,the influence of the slip ratio of the induction motor on transient voltage stability and load stability is analyzed,and a novel index of transient voltage instability which is composed of voltage drop and slip ratio increment is proposed. Furthermore,a wide area measurement system（WAMS） based adaptive load shedding scheme which is constructed by employing the novel index to determine the locations and magnitude of load curtailments is provided. This new scheme includes two control patterns including all nodes load shedding and partial nodes load shedding and it measures the transient voltage stability degree of the system more fully by using the novel index. Simulations on IEEE 39-bus system verify the effectiveness and the superiority of the proposed scheme on guaranteeing the voltage stability and frequency stability after large disturbance,comparing with the conventional control scheme.

关 键 词：暂态电压稳定性 转差率 切负荷 自适应控制 

分 类 号：TM712[电气工程—电力系统及自动化]