Hybrid simulation of large electrical networks with assymmetrical fault modelling

Owing to the increasing attention placed on dynamic security assessment in the light of recent blackouts, hybrid simulation, involving the interfacing of electromagnetic transients (EMT) simulators and transient stability (TS) simulators for the more accurate representation of very large electric networks, has been attracting considerable attention lately. The goal of hybrid simulation is to represent complex systems, such as FACTS devices and HVDC terminals, in detail, while ensuring an acceptable representation of the complete system such that control systems and switching devices are well represented. There has been significant success in this area. Most approaches, however, concentrate on contingencies that preserve the symmetry of the system. Asymmetrical faults, for example, have not been dealt with in the literature on hybrid simulation. In this paper we deal with how two very different simulators can be coordinated to work together and produce accurate solutions, even with asymmetrical disturbances. Based on the interaction protocol proposed in the paper, case studies were performed on 9-bus systems and 39-bus systems to assess the performance of the integration on both EMT and TS aspects. Very good results were achieved.