Parallel forward and back substitution for efficient power grid simulation

Parallelizing power grid simulation with factorization-based direct or preconditioned iterative methods is a challenging task due to the data dependency among forward and back substitution. In this paper, we propose two approaches to parallelize forward and back substitution. The first approach exploits the parallelism by computing independent variables in parallel; the second approach resolves the data dependency by leveraging a node ordering produced by nested dissection. According to the requirements of TAU 2012 power grid simulation contest, a parallel power grid transient simulator is developed and tested with IBM power grid benchmarks. Results show that the second approach with the nested-dissection-based node ordering is more efficient.