A method to reduce the loop of the power distribution network

Abstract

The invention relates to the field of automation of power grid dispatching, in particular to a method for reducing closed loop current of a distribution network. The method comprises the following steps of (S1) splicing a main distribution network model; (S2) evaluating the state of the spliced model; (S3) grouping capacitive reactors and sorting the capacitive reactors according to the capacity;(S4) calculating initial power flow; (S5) calculating closed loop current; (S6) judging whether calculation termination conditions are met or not; (S7) judging whether switchable capacitive reactors exist or not; (S8) sequentially switching the capacitive reactors according to the group order; (S9) calculating the power flow again; (S10) carrying out sorting according to the group and voltage amplitude variation and calculating the closed loop current; (S11) operating a main gear and calculating the power flow; (S12) calculating the closed loop current; and (S13) judging whether calculation isterminated or not. According to the method, the closed loop current can be actively reduced to a switch protection limit, trip due to the fact that the closed loop current is over-high and out of limit is prevented and a power failure risk caused by a closed loop operation failure is reduced.

Description

technical field [0001] The invention relates to the field of power grid dispatching automation, and more specifically, relates to a method for reducing the closing loop current of a distribution network. Background technique [0002] The size and distribution position of the load in the distribution network will affect the distribution of the grid voltage, so that there is a certain potential difference on both sides of the ring closing switch. When the ring closing operation is performed, under the action of the potential difference, a circulating current will be generated in the ring network, resulting in changes in the power flow distribution of the power grid. Therefore, the potential difference on both sides of the loop-closing switch caused by the asymmetry of the network structure and load distribution is the main cause of the loop-closing current. [0003] When the distribution network is overhauled and the load is transferred in the non-fault area, the loop closing...

AI Technical Summary

Problems solved by technology

When closing the loop, it is necessary to control the size of the loop closing current. Only when the loop closing current does not exceed the protection limit, can the two lines be closed. Failed, resulting in extended outages

[0004] For the distribution network, the size of the loop closing current is related to factors such as the voltage amplitude difference, phase angle difference, and equivalent impedance on both sides of the loop closing point. Once the calculated loop closing current exceeds the protection limit, according to the operating procedures, control Personnel cannot perform loop closing operation, and can only passively wait for the loop closing current to drop to the switch protection limit before performing loop closing operation. There is certain uncertainty when the loop closing current will not exceed the breaking capacity of the switch, resulting in the blackout area. recover in time

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