Calculation method and system for equivalent short-circuit ratio of a new energy cluster

Abstract

The invention relates to the technical field of new energy power generation, and specifically provides a calculation method and device for an equivalent short-circuit ratio of a new energy cluster, aiming at solving the technical problem of grid strength evaluation at a grid-connected point in a new energy cluster development mode. The embodiment of the present invention includes: determining the equivalent apparent power of each current source in the new energy cluster based on the self-impedance or mutual impedance between the current sources in the new energy cluster; based on the equivalent apparent power of each current source in the new energy cluster The equivalent short-circuit ratio of each current source in the new energy cluster is determined based on the power and the short-circuit capacity of the grid-connected point of each current source; the equivalent short-circuit ratio of the new energy cluster is determined based on the equivalent short-circuit ratio of each current source in the new energy cluster. Compared with the conventional short-circuit ratio calculation method, this scheme provides an equivalent short-circuit ratio index for evaluating the overall grid-connected strength of new energy clusters, which can provide new energy base development planning and scheduling operation. A scientific evaluation method.

Description

technical field [0001] The invention relates to the technical field of new energy power generation, in particular to a calculation method and system for an equivalent short-circuit ratio of a new energy cluster. Background technique [0002] As of the end of 2019, China's installed capacity of wind power reached 129 million kilowatts, and the installed capacity of photovoltaic power generation reached 43.18 million kilowatts. Concentration of new energy sources such as wind power and photovoltaics, and the collection and boosting of multiple power station clusters are the main development models for new energy in many regions. Areas with concentrated new energy development generally have few conventional power sources, weak voltage and frequency support, and the stability problems caused by large-scale new energy development are prominent, including transient overvoltage and broadband oscillation. Studies have shown that the occurrence of these problems has a great relation...

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Problems solved by technology

[0003] The short-circuit ratio is an important indicator to measure the power grid strength of the power / load grid-connected point. However, the conventional short-circuit ratio calculation method is mainly for a single device. For the scenario of new energy cluster grid-connected, the influence of adjacent devices cannot be considered, resulting in an overly optimistic evaluation result. , which cannot accurately reflect the true strength of new energy unit grid-connected points, which will have an impact on the planning and operation of new energy clusters

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