Hierarchical network partition of DC power systems containing a large number of switches

In order to realize the high-efficiency and automatic network partition of dc power systems that contain a large number of switches, this paper presents a hierarchical partition method. It consists of two layers. The first layer is the partition into sub-systems, its optimality criteria are optimal trade-off between the effects of uneven switch distribution and the number of cutting branches, then, a method of transferring switch nodes between the adjacent sub-systems is used. The second layer is the partition into sub-networks, its optimality criteria are optimal trade-off between the effects of uneven switch distribution and the number of state-space-nodal (SSN) nodes, then, the method of merging adjacent switch nodes at multiple points simultaneously is adopted. Further, a complete set of automatic hierarchical network partition method of dc power system is formed. Finally, a typical MVDC integrated power system and a modified 39-bus dc power system are taken as the examples to verify the effectiveness of the proposed method. Real-time simulation performance shows that the proposed method can significantly reduce the simulation step, balance the consumed simulation resources and improve the partition efficiency compared with traditional methods.