Research And Development On Protection Device Integrative Coordination System For Distribution Power Grids

Coordination is the basis of secure operation of modern power system, and the guranteefor protection device to isolate faults in time and avoid great accidents. Otherwise, atpresent there is almost no coordination software applied to distribution power grids. So itsresearch could produce significant economic and social benefit. This thesis devotes to therelative problems in this field, including the development of coordination software fordistribution power grids, the research on coordination automation technology andcoordination theory. This thesis implements the development of protection device integrative coordinationsystem for distribution power grids, whose main structure and functional division arecircumstantiated, and some important problems for development are presented. This systemrealizes the automation of power grid management, fault calculation, the whole process ofcoordination and setting requisition management, and provides the diversiform methods ofmanual interposal to ensure the adaptability and flexibility. In addition, the core module in this system, the protective relay coordination module, isparticularly described, including its mainframe, data structure and the scheme of protectiverelay extending. A completely new mainframe, in which the thoerical and equipmentalsetting coordination are separated, is constituted and insertion updation of new protectiverelay is realized, with uniform data structure and dynamically linking plug-in module.Furthermore, a new method, called relay template method, is brought forward to makecustom updation of new protective relay possible. In the aspect of coordination theory, this paper presents the issue of the zero sequencecurrent reverse in the coordination of transformer zero current relay and analyzes its reasons,the influence on relay operation and the deficiency of present coordination ways, on thebasis of which an adaptation of the common coordination method for transformer zerosequence relay is brought forward to take into account the influence of this issue. IIIn the end, the global coordination is preliminarily studied, which accomplishes thecoordination of all relays for different types of elements in a same process. Based on theestablishment of the uniform protection template, a mathematic model is proposed toexpress the primary/backup relationship in the global coordination and a method, calledautomatically expanding setting zone, is also demonstrated to intensify the alternation ofrelay settings. At the same time, this paper presents the deadlock issue in the globalcoordination and emphasizes its particularity.