Short-circuit current suppression method considering unit start-stop and line switching

Abstract

The invention discloses a short-circuit current suppression method considering unit start-stop and line switching, which comprises the following steps that firstly, a relational expression of an admittance matrix and short-circuit current is deduced by utilizing a relation between the node admittance matrix and a node impedance matrix and physical significance of node self-impedance; further the change of ground capacitance after the line is cut off and the influence of the switching line and the start-stop unit on the admittance matrix are considered to obtain a short-circuit current explicit expression; from the perspective of global optimization of the power grid, the influence of economy and current limiting measures on the aspects of system power flow, unit output and the like is comprehensively considered, and a mixed integer linear programming method considering explicit short-circuit current constraint is provided by taking the minimum power generation cost, unit start-stop cost and line switching cost as targets; and meanwhile, a day-ahead scheduling problem of a power system is combined, unit output arrangement and line switching are comprehensively optimized by considering short-circuit current constraints, and an optimal unit start-stop and line switching comprehensive scheduling operation scheme is given on the premise of ensuring economic operation.

Description

technical field [0001] The invention relates to the technical field of electrical information, in particular to a short-circuit current suppression method considering the start-up and stop of a unit and line switching. Background technique [0002] Due to the rapid growth of power load demand caused by rapid economic development and the rapid increase of power supply capacity, the short-circuit current level in the power system is getting higher and higher, and the problem of excessive short-circuit current is becoming more and more obvious. Therefore, how to limit the short-circuit current has become a problem that must be faced in the planning, dispatching and operation of the power grid. [0003] Limiting short-circuit current can start from many angles. Starting from the operation mode, it can be operated through the partition of the power grid. Although the short-circuit current can be reduced, it weakens the connection between the power grids and causes uneven power f...

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Problems solved by technology

[0006] Aiming at the problems of inaccurate expression, non-optimal solution of obtained results, and failure to consider the influence of units on short-circuit current in existing studies on line switching and current limiting, combined with the mixed integer linear programming method, the research takes into account the start and stop of units and the display of line switching and switching. Optimal dispatching of power systems under the constraint of formula short-circuit current, that is, short-circuit current suppression method. The purpose of the present invention is to provide a short-circuit current suppression method considering unit start-stop and line switching

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