发输电组合系统可靠性评估中的最优负荷削减模型分析

介绍了基于直流潮流的负荷削减线性规划模型和基于交流潮流的负荷削减非线性规划模型的基本原理,对它们各自的优缺点进行了分析,并使用它们对 RBTS(RoyBillinton Test System)可靠性测试系统进行了评估.计算结果表明,直流潮流的负荷削减线性规划模型由于忽略了节点电压约束的影响,存在较大的模型误差,要得到精确的可靠性指标,应该使用基于交流潮流的负荷削减非线性规划模型.

ANALYSIS ON OPTIMAL LOAD SHEDDING MODEL IN RELIABILITY EVALUATION OF COMPOSITE GENERATION AND TRANSMISSION SYSTEM

There are three basic aspects in the reliability evaluation algorithm of composite generation and transmission system, they are system state selection, system state analysis and updating of reliability index. The system state analysis contains power flow calculation and optimal amount of load shedding, the latter is the core of reliability evaluation which can determine whether the system is faulty and the amount of optimal load shedding that is necessary to restore system to secure state, so different load shedding model leads to different reliability evaluation result. Here, the basic principle of linear programming model of load shedding based on DC power flow and that of nonlinear programming model of load shedding based on AC power flow are presented, the merits and demerits of the two models are analyzed, and the Roy Billington Test System (RBTS) is evaluated by the two models. The calculation results show that because of the constraints of node voltages are neglected there is comparatively large model error in the linear programming model based on DC power flow, therefore if the accurate reliability indices are wanted the AC power flow based nonlinear programming model of load shedding should be adopted.