A pipelined-in-time parallel algorithm for transient stability analysis

A new parallel algorithm for transient stability analysis is presented. An implicit trapezoidal rule is used to discretize the set of algebraic-differential equations which describe the transient stability problem. A parallel-in-time formulation has been adopted. A Newton procedure is used to solve the equations which describe the system at each time step, whereas a Gauss-Seidel algorithm relaxes the solution across the time steps. A Gauss-Seidel-like procedure can be usefully exploited in the parallel processing mode by pipelining the computation through time steps. The parallelism in space of the problem is also exploited. Furthermore, the parallel-in-time formulation is used to change the time steps between iterations by a nested iteration multigrid technique in order to enhance the convergence of the algorithm. The method has the same reliability and model-handling characteristics of typical dishonest Newton-like procedures. Test results on realistic power systems are presented to show the capability and usefulness of the suggested technique.