A Research On The Fault Diagnosis Of Power Grid Based On The High-Level Petri Net

In our society, with the development of our national economy and the increasing degree of modernization, good quality, more reliable and stable power supply has become the basic requirement for our power user, the security and stability operation of power system, is not only the safeguard for people’s normal life, but also is an important basis of pushing the developing and progress of our social.But more uncertainties associated with the grid, which lead to the stability of the power system will be affected, the failure of grid is inevitable and the harm is also obviously. In order to detect the fault in the shortest time, solve the problems and the normal operation of the state power system and restore to the normal state of power system, we need a quickly and effective fault diagnosis system. It is necessary to do the research of fault diagnosis technology, which has theoretical and practical value.All knows, large-scale power grid has the characteristics of many components and wiring complexity, which leads to great inconvenience about our analysis. In this paper, we do the fault location first, according to a certain priority, we divided large grid into a passive sub-networks and ensure that the fault element in the sub-network. We use the colored Petri net model combined to the power system tie line analysis, simplify the analysis is our purpose.Secondly, the paper using simple Petri net to do the fault diagnosis on the grid and expose the flaws in the process of modeling and application that is the simulation ability is not strong, protection relay level grading is simple, especially when the grid size increases, we will face high operational dimension, changing topology and so on of grid. We introduced predicate Petri net in the diagnosis process instead of a simple Petri net, diagnosis model is dynamically created in each direction, which can adapt to changes in the structure of the network topology effectively, good real-time will reduce the size of the grid operation, and based on the actual type of protection, we can solve the problem of the protection scope is unclear, making diagnosis results clearly. The concept of the time constraint is presented. We use the operation timing relationship of protective devices and circuit breaker, to evaluate the operation information in system which we collected. We can check out the components which have unwanted operation or fail to operate, so we will improve the accuracy and fault tolerance of the diagnose system. And it provide reliable failure analysis evidence to engineer. The instance simulation results show that this program is feasible and effective.