Solution method based on the theory of diakoptics for an efficient time-domain transients simulation of HVDC converters

In this paper, the tearing of large networks, also known as "diakoptics" is applied to the time-domain simulation of HVDC converters. A complete twelve-pulse bridge is partitioned into two six-pulse bridges plus the links connecting the independent bridges. The AC part of the network containing the generators and transformers is also represented and separated from the converter bridges through links. This way, the computational cost of the simulation, measured by the number of FLOPS is reduced. Other numerical issues regarding the simulation of power electronics based networks such as the numerical oscillations that are a consequence of the trapezoidal integration rule are investigated. Results are presented and compared in terms of efficiency with the conventional EMTP solution, where the complete network is simulated as a single entity.