Self-adaptive three-sectional protection setting method and device

Abstract

The invention relates to a self-adaptive three-sectional protection method which is based on three protection means of current quick-break protection, current quick-break protection with time limit, and overcurrent protection. The method comprises the following steps: 1). accurately acquiring voltage and current in real time through an adaptive filtering algorithm so as to obtain a fundamental wave current amplitude i1; 2). respectively performing setting on the three protection means so as to obtain corresponding setting values IDZ.I, IDZ.II, and IDZ.III; 3). when i1> IDZ.I, taking a current quick-break protection measure, otherwise, skipping to step four; 4). after a time period TII, if i1> IDZ.II, taking a measure of the current quick-break protection with time limit, otherwise, skipping to step five; and 5). after a time period TIII, if i1> IDZ.III, taking an overcurrent protection measure, otherwise, ending the three-sectional protection method. The method and device provided by the invention has the following advantages: the reliability and stability of a distribution network are improved, and the protection sensitivity and accuracy are substantially enhanced without changing the basic principle of three-sectional current protection.

Description

Technical field [0001] The present invention relates to the field of relay protection, in particular to a setting method and device for adaptive three-stage protection. Background technique [0002] Relay protection is an important technical measure and means for the safe operation of power systems. Traditional relay protection settings are mostly obtained by offline calculation according to the maximum operation mode of the power system, and the sensitivity of the protection is verified according to the minimum operation mode of the power system. It cannot be adjusted according to the operation mode, topology, fault type, internal parameters and load of the system. The setting value will be corrected in real time. This setting method has the following disadvantages: The protection setting is generally determined according to the most severe operating conditions. Although it can be guaranteed that the protection can operate correctly in various operating modes, the best protecti...

AI Technical Summary

Problems solved by technology

Most of the traditional relay protection setting values ​​are calculated offline according to the maximum operation mode of the power system, and the sensitivity of the protection is verified according to the minimum operation mode of the power system. real-time correction of the setting value

This setting method has the following disadvantages: the protection setting value is generally determined according to the most serious operating conditions. Although it can ensure that the protection can operate correctly in various operating modes, it cannot achieve the best protection for faults that occur in non-maximum operating conditions. Effect; once the setting value is determined, it will not change in a short period of time, and cannot adapt to changes in power system topology, fault types, equipment parameters, operation modes and loads in the system. When the system changes, the selectivity and sensitivity of protection will be seriously reduced. even lose protection

With the expansion of the scale of the power system, the structure of the distribution line network and the form of power supply are becoming more and more complex, and the traditional protection of distribution lines can no longer meet the requirements of the power system.

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