The specific features of mathematical models of electrical circuits oriented toward parallelization of the computational process have been identified, confirming the need to formulate a mathematical model of a subsystem with lumped parameters in the form of a multiport network. The characteristics of parallelizing the solution of systems of partial differential equations have been determined, which made it possible to define spatial-parallel methods for such systems and to construct, in particular, mathematical models of circuit segments with distributed parameters in the form of subschemes. It has been shown that methods of separate integration of subschemes are capable of parallelization, which enables the development of typical algorithms and their implementtation in a software package. Numerical experiments have been conducted to verify parallel diakoptic methods, aimed at confirming the properties of various numerical methods for subscheme computation and determining the influence of subscheme macromodel accuracy on the adequacy of transient processes.