Algorithms for Distributed Computation of Electromagnetic Transients towards PC Cluster Based Real-Time Simulations

This paper describes algorithms for the distributed computation of electromagnetic transients in a power system. Conventional simulators based on parallel computing utilize traveling-time delays due to Bergeron's representation of transmission lines in order to divide the network of interest into subnetworks, and each subnetwork is assigned to a single CPU to solve the decoupled sets of the circuit equations in parallel. However, if a large subnetwork which cannot be divided further by a transmission line is found, this limits the overall performance of the simulator. In the case of a real- time simulator, this forces a large time step. To solve this bot- tleneck, two algorithms are described in this paper. One di- vides the network at series inductors and the other at shunt capacitors (series and shunt with respect to the ground). Since series inductors and shunt capacitors are found in many loca- tions in a power system, the algorithms increase the possibility for dividing a network into subnetworks achieving optimal computational load assignment to the CPUs in a parallel com- puter.