Hierarchical Hybrid Modeling and Simulation for Digital Protection System

This paper proposed a new method of establishing the generalized hybrid Petri nets (GHPN) model for the digital relay using the object-oriented Modelica modeling language. Due to the digital protection system exhibits both continuous variable and logic event behavior, this paper use hierarchical structure to decompose the complexity of protection system. The high level use for to express the logic dynamic behavior of digital relay, while the low level use for to describe the continuous dynamic behavior. The method of GHPN modeling is introduced in detail. Using GHPN model of protection relay, the entire inner dynamic behavior of protection system can be simulated, and the interaction between protection systems and power systems is also simulated. This new GHPN modeling approach makes the protection system simulation quite efficient, flexible and accurate