输电系统风险评估中的分层分级负荷削减模型

Hierarchical load shedding model for transmission system risk assessment

负荷削减计算是输电系统风险评估中的关键步骤。为解决目前负荷削减模型还存在的没有考虑无功潮流和节点电压约束、无法考虑负荷类型削减优先级对风险指标的影响等不足,提出了一种分层分级最优负荷削减模型。按负荷类型重要度从高到低依次分层削减负荷,兼顾就近和最优原则,将参与负荷削减的节点限制在一定分级范围内,减小计算规模。IEEE-RTS6算例表明,所提出的模型在保证准确性的前提下,相比传统方法能够极大减少重要负荷的削减次数和电力不足期望,更符合系统实际运行要求,并一定程度上减少计算时间。

Load shedding calculation is a key step in transmission system risk assessment.To overcome the shortcomings of the current load shedding model,such as its ignorance of reactive power flow and node voltage constraints,and the ignorance of the impact of load shedding priority on the reliability index,a hierarchical optimal load shedding model is proposed.Load is hierarchically cut from high to low according to the load shedding priority,and the principle of proximity and optimization is taken into account.The nodes participating in the optimal load shedding calculation are limited within a certain range to reduce the calculation scale.The IEEE-RTS6 example shows that the proposed model could greatly reduce the operation times and power shortage expectations of important loads compared with the traditional method under the premise of ensuring accuracy.This is more in line with the actual system requirements,and to some extent reduces the calculation time.