Method for fault component-based wide area backup protection

Abstract

The invention discloses a method for fault component-based wide area backup protection, which belongs to the field of relay protection for electric power systems. The method comprises the following steps of: when a power network is in normal operation, dividing protection associated domains according to a topology structure and the PMU configuration of a network; updating the protection associated domains in real time by adopting a heuristic search technique according to switch transposition information; when a fault happens, extracting fault stable-state components of current and voltage, and defining fault associated domains according to the fault stable-state component of differential current in each associated domain; and calculating fault associated factors in the associated domain in real time to determine fault branches. The method can accurately position the faults under a condition with PMU limited measuring points, is not influenced by the system operation mode, avoids the condition that the conventional backup protection can have mismatching or insufficient sensitivity very easily, is not influenced by load current, and has very high reliability.

Description

technical field [0001] The invention relates to the field of electric power system relay protection, in particular to a wide-area backup protection method based on fault components. Background technique [0002] With the rapid growth of my country's electricity demand and the implementation of the strategy of "power transmission from west to east, mutual supply between north and south, and national networking", my country is forming a weakly connected national interconnected power grid. As of the end of 2009, my country's power grid installed capacity has exceeded 850 million kilowatts, ranking second in the world, and will maintain an annual growth rate of 10.5% during the "Eleventh Five-Year Plan" period; according to the power development plan, by 2020, my country's power grid It will become an ultra-large-scale national interconnected power grid with an installed capacity of more than 1.6 billion kilowatts and a west-to-east power transmission capacity of more than 150 mi...

AI Technical Summary

Problems solved by technology

[0004] 1) The coordination relationship of backup protection is complex and the action time is long

In severe cases, it may not meet the limit cut-off time required by the system stability, and then become a safety hazard of the large power grid;

[0005] 2) The backup protection configuration and setting are very difficult, and it is impossible to track changes in the system operation mode, and even protection mismatch or insufficient sensitivity may occur;

[0006] 3) The backup protection cannot distinguish between the internal fault and the power flow transfer caused by the fault removal, which may lead to chain tripping of the backup protection under heavy load conditions

The method of applying the fault steady-state component to the backup protection has not been reported so far

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