Numerical integration algorithms in power-system dynamic analysis

The outcome of recent test applications of a range of integration algorithms to models representative of those now widely encountered in large- scale power- system dynamic analysis is reported. The paper collects together the main requirements of practical dynamic analysis, and it gives the principal schemes and solution strategies that might be used in meeting these requirements. Plant equation sets are summarised in a form that is of general application and interpretation in large analysis schemes, and, for these sets, comparative studies are made of the performance of explicit and implicit methods of single- and multiple-step sequences of numerical integration. In total, some ten different methods have been included in the evaluations, and, for most of these, two, and, in some cases, three, alternative modes of implementation are studied and compared. Methods of decomposition are invoked to allow different step lengths, and, where required, different integration methods, to be associated with individual subsets of significantly different response rates. Finally, the likely role of automatic algorithm control in this area of applied analysis in power systems is discussed