The Research On Online Setting Solution For Backup Protection In Power Grid

With the power grid growing and expanding usage of new energy technologies, grid operation modes are increasing in a large scale, which makes the relationship with each relay protection system more complicated. Thus, the protection system, in particular the reliability of backup protection is required unabatedly. Back-up protection of traditional offline setting mode currently used to calculate the value, existing heavy workload, low computational efficiency, poor protecting performance problems. Under the background of smart grid, along with information and communication technology upgrades and intellectualization of protection devices, using online backup protection setting mode, real-time changes according to the power grid in order to adjust the setting to play the best performance of the device already has a preliminary condition. However, the calculation method of online setting and tuning programs still needs to be further study.This paper comes up with a correspondent solution based on increment factors with topology and matrix theory and algorithms. Firstly, reference node in the fault analysis network model is reselected, to derive the formula of the branch coefficient magnification when operation mode changes, while the method of increment factors is introduced. Afterwards increment factor calculation methods for power and branch in the model are given respectively. It also can be drawn that coefficients of incremental factors, which can be pre-computed, are only relevant with the initial operating mode before mode changes. Finally, calculation procedures of online pre-set for backup protection and real-time setting are shown in charts. A case is put to validate the correctness of the solution and applicability of the calculation efficiency.Increment factors Method is an attempt for exploring the backup protection online setting.Moreover, from the computer software level, this paper introduces the cross-platform UI framework-Qt, its characteristics and advantages, to serve as the basis for the protection of online backup setting software design and development. It also contains an emphasis describing the computer modeling part of the system used in graphics technology and design processes.