Study On Reliability Of Power Optical Fiber Communications Network

In recent years, with the continuous development of science & technology, power system has been closely linked to communications system, and the monitoring and control in power system is increasingly dependent on the reliable running of communications system. Thus, the reliability of communications system is directly related to the safe and stable operation of power system. So far, a huge SDH optical transmission network has been established in power system so as to transmit voice, data and multimedia services, etc. However, the high transmission capacity of optical communication system can greatly enlarge the impact of failures in a single component on the entire system, huge loss to the power system would be caused once failures occur in the key components. Therefore, it's of great significance to study the reliability of optical-fiber power communications network.In this thesis, the current methods to study reliability of communications network are analyzed, and the RBD diagram is used to calculate the reliability of simple and complex network structures. On this basis, a minimal-path-set-based algorithm (T-MP algorithm) that can be used to calculate the reliability of power communications network is put forward. By improving the traditional node traversing method, this algorithm can work out the minimum path set containing both nodes and links with the help of network topology. Subsequently, the BDD algorithm with rapid generation technology is used to make the acquired minimum path sets non-disjoint, thereby acquiring the non-disjoint minimum path sets. Then, the reliability of source-destination node pairs in the network is calculated by summing the probability of each item directly.In this study, the typical optical-fiber communications network for power system is introduced, and a method to measure the reliability of equipment according to its actual operation records is given. Subsequently, the method is used to calculate the service availability between source and destination nodes in an actual network. Also, using this method, the impact of network topology on availability is analyzed, the "N-1" availability is calculated, and the impact of changes in key nodes/links and non-critical nodes/links on the network reliability is analyzed.This thesis gives a method for availability calculation, in which the service performance is taken into account. At the same time, in accordance with the actual requirements of services, the network availability based on service performance is calculated, thus enhancing the practical significance of the results.According to the results, methods to improve network availability are acquired, namely, to enhance the reliability of transmission medium and the inherent reliability of equipment, optimize the network topology, and improve the working environment of equipments, etc.