Secondary system reliability assessment of intelligent substation based on fault tree analysis and effect assessment method

With the development of intelligent electrical, the application of intelligent equipment, the development and application of high-speed computer network in real-time systems and time device status detection technology is getting mature, a numbers of smart substations are going to be build, which intelligent technology is dependent the reliability of the second and automation systems. Several domestic and international grid blackouts in recent years also show that the failure of the secondary systems is an important reason to cause these accidents. Currently, most of the power system reliability management system has done around the first system, and for the secondary system of reliability management is far from perfect, especially the intelligent substation secondary system reliability management has not carried out. For this problem, study the intelligent substation secondary system from the hardware devices, data and communication interface, the device features modules and other aspects, the hardware structure of smart substation secondary system compared to the conventional substation has occurred great changes, but its main function modules did not change with the change of hardware technology, which makes the reliability of the modules from a view of functional of the system assess even more scientific and stable. combine the fault tree analysis and the effectiveness assessment to establish the reliability of the system as a model. For analyzing the reliability of the secondary system quantitatively this paper has established the reliability index of sub-module and whole system, and identify the weak links by the index. The work of this paper will have a positive impact to the future intelligent substation system design, equipment selection and the actual operation.