A new algorithm for auto assigning power system components to processors has been introduced in RSCAD V5 to minimize the number of backplane transfers within a simulation time-step. The processor assignment algorithm can be selected by right-clicking on the white space in DRAFT and selecting ‘Circuit Options’ from the context menu that appears. A dialog box will open as shown in Fig. 1 and that allows the user to specify the processor assignment algorithm. Previously used algorithm (Load Balanced) was based on load units only. The idea was to evenly distribute the load among the available processors.
If power system components are connected to a common bus, and executed on the same processor, the current injections can be combined. The Advanced feature allocates power system components to processors such that, power system components connected to the same bus are placed on the same processor. This allows current injections to be combined and optimizes the DRAFT case. For example, placing two synchronous machine models that are connected to a common bus, on the same processor would result in three variables (three currents) being sent to the network solution rather than the backplane transfer of six variables (six currents) if the two machines are placed on different processors. Combining current injections will help in keeping the time-step down as the number of backplane transfers are reduced.
In RSCAD V5, the Advanced mode is used as the default algorithm. If required, the old algorithm (Load Balanced) is available for the user to select.