In a deregulated environment, optimal transmission switching (OTS) plays an important role in coordination among power generating companies (GENCOs) and transmission company (TRANSCO) by minimizing operating costs. This paper solves ac OTS (ACOTS) in two different stages sequentially with ac optimal power flow (ACOPF) and transmission switching through ac power flows (TS-ACPF) for optimal power generation and efficient power transmission, respectively. The mutual dependency along with the coordination among these optimal problems are treated intelligently by adopting a metaheuristic based two-stage algorithm with a multi-objective approach to achieve an effective solution through maximum utilization of power in the existing system or for future expansion planning. Production cost optimization problem is taken care of in the first stage while transmission loss is optimized in the second stage with successive iterations of the proposed algorithm. MATLAB simulations to optimize both transmission loss and production cost for both the IEEE-30 bus system and the Indian Utility 62-bus real system are experimented. Results are provided to validate the proposed technique which satisfies several cases of load variations, N − 1 standards and other combinations of stressed security constraint conditions. The detailed investigation of the results prove the effectiveness of the proposed intelligent two-stage method over the existing methods in terms of automatic and cost-effective bi-objective solution relying on the flexibility of switching strategy and security by avoidance of islanding without any manual interaction in between.

在放松管制的环境中，最优输电交换（OTS）通过最小化运营成本在发电公司（GENCO）和输电公司（TRANSCO）之间的协调中起着重要作用。本文分别通过交流最优功率流（ACOPF）和通过交流功率流（TS-ACPF）进行传输切换的两个不同阶段来依次解决交流OTS（ACOTS），以分别实现最优发电和有效功率传输。通过采用基于元启发式的两阶段算法和多目标方法，可以智能地处理相互依赖关系以及这些最优问题之间的协调，从而通过最大程度地利用现有系统或未来的扩展计划来实现有效的解决方案。在第一阶段处理生产成本优化问题，而在第二阶段使用所提出算法的连续迭代对传输损耗进行优化。实验了MATLAB仿真，以优化IEEE-30总线系统和Indian Utility 62总线实际系统的传输损耗和生产成本。提供的结果可验证所提出的技术能够满足几种负荷变化，N-1标准以及受压安全约束条件的其他组合的情况。