Electromechanical Transients Simulation on a Multicomputer via the VDHN-Maclaurin Method

This paper reports simulations of power systems electromechanical transients on a multicomputer, formulated as a nonlinear algebraic problem by using the time parallelization concept. The bifactorized inversion, which is the most time-consuming stage of the simulation, is solved by the "very dishonest Newton-Maclaurin" (VDHN) method, a fully parallel indirect method based on the decomposition of the nonupdated Jacobian matrix. This proposal is made to orient the search for the decomposition based on a sufficient condition for the convergence of the Maclaurin series, which is a desirable situation for the design of more robust algorithms for power system simulation. Such condition keeps a close relation with a physical coupling property exhibited by power systems and the characteristics of the simulation method. Theoretical and numerical results show that a successful implementation of this method can be better reached when the Jacobian matrix is decomposed as a block diagonal matrix plus a matrix with off diagonal blocks elements, the latter representing weak couplings between the diagonal blocks. The e decomposition is used to satisfy the sufficient condition for convergence and the longest path scheduling method to prevent the uneven loading of processors, permitting adaptation of the method in an efficient way on a coarse grain computer. The parallel simulation was written in C language and implemented on a Parsytec PowerXplorer multicomputer. Test using electromechanical models of the Chilean Central Interconnected system and the IEEE300 test system were made to evaluate the advantages and drawbacks of the parallel method.