分布式潮流计算异步迭代模式的补充和改进

从原理上对基于异步迭代模式的互联系统分布式潮流计算方法进行了补充分析.每个子系统可以通过数据交换修正其外网的戴维南等值,通过构造基于边界节点状态量的不动点迭代格式,使得异步迭代计算能获得等同于全网潮流的计算效果.从实用性的角度补充说明了该算法的具体实现模式,将分布式计算分为实时等值、异步迭代初始化和异步迭代3个阶段,制定了各个阶段中协调层的代理机制,实现了各子系统间的完全异步运算.子系统可保留传统建模方式,加入和退出分布式计算可灵活选择,特别适合各控制中心之间分层分布能量管理系统(EMS)的应用.在IEEE 118节点系统及一个实际系统的算例中验证了算法的收敛性.

Supplement and Improvement of Asynchronous Iteration Mode for Distributed Power Flow Between Multi-control-centers

Distributed power flow algorithm for EMS application of multi-control-centers based on asynchronous iteration is theoretically studied in this paper. Based on online tracing of Thevenin equivalence for exterior-network, a fixed-point iteration scheme for boundary state variable is designed and an asynchronous iteration algorithm is proposed. This algorithm can follow the variation of system state and give a consistent power flow result with the whole power system calculation. This algorithm is implemented by three steps: real-time equivalence, asynchronous iteration initialization and asynchronous iteration. Agent mechanism for coordination layer is established and applied to the three algorithm steps and a complete asynchronous iteration is realized. Some measures are taken to ensure that the accustomed modeling methods for sub-systems are still usable. It is free for any sub-system to join in or quit from the distributed calculation. So, this method is very suitable for the application of distributed EMS under a poor communication condition between control centers. The convergence performance of the algorithm is testified by digital simulations on IEEE 118-bus system and a real system.