Method and device for improving voltage sag of distribution network

Abstract

The invention discloses a method and a device for improving voltage sag of a distribution network. The method comprises steps: two distribution network models are built, the tail end of a preset line of one distribution network model is provided with series capacitors, a target parameter is configured for each distribution network model respectively, and according to the target parameter, a voltage sag magnitude and a voltage jump magnitude of each load node in each distribution network model are determined; and according to the voltage sag magnitude and the voltage jump magnitude, effects of improving the distribution network voltage quality by the series capacitors are determined. Through additionally arranging static load elements and multiple induction motors when the distribution network models are built, superimposed starting of the static loads and the multiple induction motors in the actual distribution network on influences on the distribution network voltage sag are considered in the simulation process, influences on the distribution network voltage sag by starting of the induction motors can also be reflected, and thus, the actual condition of the distribution network can be reflected accurately.

Description

technical field [0001] The invention belongs to the technical field of distribution networks, and in particular relates to a method and a device for improving the voltage drop of a distribution network by using series capacitors. Background technique [0002] With the development of the economy and the wide application of high-tech equipment, users have higher and higher requirements for power quality. In the power distribution network, during the starting process of the induction motor, the stator side current can reach 4 to 7 times the rated current, so it will cause a large voltage drop in the power distribution network, resulting in a sudden drop in the voltage at the user end. Especially for high-power induction motors, the degree of voltage slump is more obvious during the start-up process. [0003] For some power distribution networks with weak grids, small wire diameters, large power supply radius, multiple large-capacity induction motors or rapidly changing industr...

AI Technical Summary

Problems solved by technology

The main disadvantages of this method are: ① This method does not consider the influence of the induction motor starting on the voltage sag of the distribution network with multiple lines

②This method does not consider the influence of the static load in the actual distribution network and the superimposed starting of multiple induction motors on the voltage sag of the distribution network

③This method does not consider the impact of transformer taps on the effect of series capacitors on improving the distribution network voltage sag

Therefore, this method cannot fully reflect the situation in the actual distribution network where the series capacitor improves the voltage sag in the distribution network caused by the induction motor starting, and cannot effectively use the series capacitor to improve the voltage quality of the users in the distribution network.

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