A multirate ROW-scheme for index-1 network equations

Multirate methods exploit latency in electrical circuits to simulate the transient behaviour more efficiently. To this end, different step-sizes are used for various subsystems. The size of these time steps reflect the different levels of activity. Following the idea of mixed multirate for ordinary differential equations, a Rosenbrock–Wanner based multirate method is developed for index-1 differential-algebraic equations (DAEs) arising in circuit simulation. To obtain order conditions for a method with two activity levels, P-series (and DA-series) are generalised and combined for an application to partitioned DAE systems. A working scheme and results for a benchmarking circuit are presented.