Propagation characteristic-based short-circuit voltage sag characteristic quantity calculation method of power distribution network

Abstract

The invention discloses a propagation characteristic-based short-circuit voltage sag characteristic quantity calculation method of a power distribution network. The propagation characteristic-based short-circuit voltage sag characteristic quantity calculation method comprises the steps of acquiring a parameter of the power distribution network, calculating a steady-state power flow of the power distribution network to obtain a steady-state voltage of each node of the power distribution network, and calculating load equivalent impedance; forming a conversion matrix of a transformer according toa transformer parameter, correcting equivalent impedance among nodes, and building a propagation matrix of voltage sag passing through the power distribution line; considering a power supply-fault point connection line as a fault feeder, considering other feeders as non-fault feeders, building a voltage slag characteristic equation of the fault feeder, and building a voltage sag propagation characteristic equation from a fault source to a load end by combining the transformer and a line propagation matrix; and calculating voltage sag characteristic quantity distribution in the power distribution network under different fault types according to the voltage sag propagation characteristic equation. A parameter of the power distribution network and the structure characteristics thereof can beutilized, the voltage sag distribution characteristic is analyzed, the method is simple and effective, and engineering application is easy.

Description

Technical field [0001] The embodiment of the present invention relates to the technical field of power quality control and analysis, and in particular to a method for calculating short-circuit voltage sag characteristic quantities of a distribution network based on propagation characteristics. Background technique [0002] With the development of economy and the improvement of the level of science and technology, the level of production automation in modern industrial parks is getting higher and higher, and the production equipment tends to be integrated and dense. On the one hand, based on the large investment of industrial loads of computers and microprocessors, the sensitivity of power grid equipment to load characteristics has increased; on the other hand, the widespread use of power electronic equipment and frequency conversion equipment has made the structure of urban power The power quality of the power grid puts forward higher requirements. Voltage sag is mainly caused b...

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Problems solved by technology

The monitoring period is long and the cost is high, and the monitoring data is easily affected by equipment and the external environment, and the data accuracy cannot be guaranteed. At the same time, the voltage sag research based on the monitoring data belongs to post-accident analysis, which is not conducive to the user's early perception of voltage sag and Timely implementation of prevention and compensation measures

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