Short-circuit current calculation method and system

Abstract

The embodiment of the invention discloses a short-circuit current calculation method and system, and the method comprises the following steps: S01, forming a basic database according to an actual power grid, and building a model of a set power grid operation mode; s02, scanning the short-circuit current level of the whole network; s03, solving each sequence impedance reduced to the short-circuit point by using a Newton method in combination with an iterative method, and solving the total current of the short-circuit point; s04, superposing the positive sequence component, the negative sequencecomponent and the zero sequence component of the total current of the short-circuit point to obtain a final short-circuit current; an inverter circuit, a control system and a boosting transformer control circuit are utilized. The positive sequence component, the negative sequence component and the zero sequence component can be superposed to obtain voltage and current of each phase; a set value of the internal potential of the inverter type photovoltaic power supply is generated through the step-up transformer control circuit recursive function, an overall mathematical model of a line power grid is established, the calculation amount is reduced, the calculation speed is increased, the calculation time is shortened, the operation efficiency is improved, the power supply safety can be improved, and the power grid can flexibly operate.

Description

technical field [0001] The embodiment of the present invention relates to the technical field of distribution network lines, and in particular to a short-circuit current calculation method and system. Background technique [0002] In recent years, the rapid development of the power grid has gradually increased the attention of the research on the grid partition scheme. In my country, represented by the power grids of heavy load centers such as Beijing and Shanghai, the network structure after the partition operation of the power grid has not fully played its role. For example, Incomplete zoning structure, unbalanced development of zoning power grid, high level of short-circuit current, poor reliability of power grid operation, etc., the zoning power grid still cannot fully meet the needs of future development. Based on the existing grid zoning structure, it is currently used to calculate the short-circuit current of the zoning power grid The method and system also have followi...

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Problems solved by technology

[0005] For this reason, the embodiment of the present invention provides a short-circuit current calculation method and system. The generalized Tellegen algorithm is used to combine the Newton method, the iterative method and the symmetrical component method, and the overall mathematical model of the line grid is established to calculate the short-circuit current. Some short-circuit calculation methods for line grids simplify the calculation process and reduce the amount of calculation, so that the calculation speed is accelerated, the calculation time is reduced, and the operation efficiency is improved. It can not only improve the security of power supply, but also realize the flexible operation of the power grid. To solve the problems in the prior art due to poor calculation accuracy of short-circuit current, large calculation amount and low calculation efficiency

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