暂态稳定约束下的负荷经济分配

针对电力系统中存在的暂态稳定问题,提出了一种不受系统模型限制的电力系统动态安全调度的算法.该算法基于关键线路有功潮流对其临界切除时间的线性和二次函数拟合,把临界切除时间表示的暂态稳定性约束转化为关键线路有功潮流表示的暂态稳定性约束,并把此约束作为增广约束加入到传统的最优潮流模型中,采用传统求解方法直接进行求解.该方法能够同时处理多个故障,避免了在解除某些故障情况下的稳定裕度约束之后,又会出现其他故障情况下稳定裕度不足甚至失去稳定的循环调整情况,并满足一定的经济性.新英格兰测试系统的分析结果表明,在系统总发电成本增加最小的情况下,系统的稳定程度已提高到设定的目标,证明了该算法的有效性.

Economic Load Dispatch with Transient Stability Constraints

A all-model algorithm for economic load dispatch was presented to tackle transient problems in power system. Based on the linear and quadratic estimates of the active power flow of critical line with respect to critical clearing time ( CCT) , the algorithm transformed transient stability constraints represented by CCT into those denoted by active power flow of critical line, and the active-power-flow-based constraints were added to conventional optimal power flow (OPF) model, which is available from the general method. By simultaneously dealing with diverse contingencies, the method can avoid an adverse case in which the preventive control aiming at a certain contingency might worsen the rescheduling results of the remaining contingencies and at the same time satisfies its economic goal. The generator cost increased least after generation rescheduling to meet high stability requirements in New England test power system, which shows effectiveness of the algorithm.