A Checking Algorithm for Line Protection of Distribution Network

Abstract

The invention belongs to the technical field of power grid dispatching operation and relay protection, and particularly relates to a power distribution network line protection constant value checkingalgorithm. The power distribution network line protection constant value checking algorithm includes: setting a node of allowing new energy to access a power distribution network and a corresponding parameter; determining the number of protections which are affected by new energy access and need to perform constant value checking according to the features of a looped network structure and open loop operation of the power distribution network; manually inputting or online-acquiring the output power of a new energy power supply in an EMS system, and setting the output power as a short-circuit calculation initial value; encoding a fault calculation result according to the number of the protections to be checked and branches where the protections are located; performing constant value checkingon a phase current protection, a zero sequence current protection, a phase distance protection, and a grounding distance protection, and determining the selectivity and the sensitivity of the constant values; and finally outputting the checking result. The objective of the invention is to achieve protection constant value adaptation checking according to the features of the power distribution network after mass new energy is accessed currently.

Description

technical field [0001] The invention belongs to the technical field of power grid dispatching operation and relay protection, and in particular relates to a fixed value check algorithm for distribution network line protection. Background technique [0002] Relay protection is one of the most important secondary devices in the power system, and its accuracy and reliability are directly related to the safe operation of the power system. In order to ensure the "selectivity, sensitivity, rapidity and reliability" requirements of relay protection, the traditional relay protection is based on the mode of "pre-setting and regular calibration", and a large number of methods are combined and calculated to make the protection fixed. The value can cover various possible operation modes of the power system to ensure that the requirements of quickly isolating faults and retaining normal equipment are met. However, with the rapid development of the power system, especially the large-scal...

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Problems solved by technology

A calculation method and system for online checking of relay protection fixed value (CN201610965216) proposes a fast checking algorithm based on the parallel principle, but it is mainly used in ultra-high voltage power grids, without considering the structure and operation characteristics of the distribution network, In particular, there is no check calculation involving protection ratings after new energy access

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