  Transient stability simulation of a large-scale and interconnected electric
power system involves solving a large set of differential algebraic equations
(DAEs) at every simulation time-step. With the ever-growing size and complexity
of power grids, dynamic simulation becomes more time-consuming and
computationally difficult using conventional sequential simulation techniques.
To cope with this challenge, this paper aims to develop a fully distributed
approach intended for implementation on High Performance Computer (HPC)
clusters. A novel, relaxation-based domain decomposition algorithm known as
Parallel-General-Norton with Multiple-port Equivalent (PGNME) is proposed as
the core technique of a two-stage decomposition approach to divide the overall
dynamic simulation problem into a set of subproblems that can be solved
concurrently to exploit parallelism and scalability. While the convergence
property has traditionally been a concern for relaxation-based decomposition,
an estimation mechanism based on multiple-port network equivalent is adopted as
the preconditioner to enhance the convergence of the proposed algorithm. The
proposed algorithm is illustrated using rigorous mathematics and validated both
in terms of speed-up and capability. Moreover, a complexity analysis is
performed to support the observation that PGNME scales well when the size of
the subproblems are sufficiently large.
