Equivalent short-circuit ratio calculation method and system for new energy cluster

Abstract

The invention relates to the technical field of new energy power generation, particularly provides an equivalent short-circuit ratio calculation method and device for a new energy cluster, and aims tosolve the technical problem of grid-connected point power grid strength evaluation of a new energy cluster development mode. The equivalent short-circuit ratio calculation method comprises the stepsof determining equivalent apparent power of each current source in the new energy cluster based on self-impedance or mutual impedance among the current sources in the new energy cluster; determining an equivalent short-circuit ratio of each current source in the new energy cluster based on the equivalent apparent power of each current source and the grid-connected point short-circuit capacity of each current source in the new energy cluster; and determining an equivalent short-circuit ratio of the new energy cluster based on the equivalent short-circuit ratio of each current source in the newenergy cluster. According to the equivalent short-circuit ratio calculation method, for a new energy cluster access region, compared with a conventional short-circuit ratio calculation method, an equivalent short-circuit ratio index for evaluating the overall grid-connected strength of the new energy cluster is provided, and a scientific evaluation method can be provided for development planning and scheduling operation of a new energy base.

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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