Line length boundary calculation method satisfying positive sequence voltage fault component measurement constraints

Abstract

The application discloses a line length boundary calculation method meeting positive sequence voltage fault component measurement constraints, and belongs to the technical field of relay protection of power systems. The method discloses the following technical scheme: a positive sequence fault component augmented network is constructed, an analytical expression of a positive sequence voltage fault component of adjacent protection devices is established, spatial distribution characteristics determined by backside equivalent impedance and line parameters are extracted, and the minimum line length boundary is dynamically calculated in combination with a voltage transformer measurement accuracy constraint, so that the spatial distribution difference of the amplitude of the positive sequence voltage fault component is revealed, and finally a theoretical basis for realizing adaptive cooperation of adjacent protection based on inverse time limit characteristics is provided. The application has good adaptability and robustness, is suitable for various grounding modes and fault types, does not need additional hardware modification, and can be widely applied to intelligent distribution network protection systems. Simulation results show that the application can effectively improve protection reliability and avoid the problem of protection mismatch caused by DG access.

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