Feasibility Study on Online DSA Through Distributed Time Domain Simulations in WAN

As power systems become more closely interconnected and are deregulated, multi-area united online dynamic security assessment (DSA) is highly demanded. In this paper, a distributed framework for carrying out multi-area united online DSA over a wide area network (WAN) is proposed. In this framework, different control centers take part in the computation in a distributed processing manner with only boundary conditions being exchanged. To make the distributed DSA feasible for online use, a high performance distributed transient simulation algorithm is presented. Moreover, the overall time cost of the multi-case distributed simulations is modeled by analogizing the influence of different computation and communication resources. Based on the theoretic model obtained, the optimal task scheduling strategy is studied for scanning multiple contingencies. A distributed simulation platform which can emulate the WAN communication environment is built up, and the standard IEEE 39-bus system and a real Chinese power system with 5422 buses are used as test systems. Results demonstrate that with current computing and communication techniques, distributed DSA can fully satisfy the requirements of online use.