Commutation sequence control method and system based on energy function

Abstract

The invention discloses a phase sequence changing control method and system based on an energy function. The method comprises the steps of calculating fault removal energy and critical energy, judgingwhether phase sequence changing needs to be conducted or not according to the fault removal energy and the critical energy, if so, further judging whether a stable balance point power angle and a current power angle both meet phase sequence changing conditions or not, and conducting phase sequence changing if the stable balance point power angle and the current power angle both meet the phase sequence changing conditions; then calculating the energy difference before and after phase sequence changing, obtaining a first energy sum value according to the critical energy, determining whether thesystem is stable or not according to the first energy sum value, and if the system is unstable, repeating the phase sequence changing process until the power system is stable. By means of the method,when the power angle of the power system is unstable to a second set power angle, phase sequence changing is rapidly conducted through a power electronic switch, and then the stability of the power system is improved.

Description

technical field [0001] The invention relates to the technical field of power system stability control, in particular to an energy function-based commutation sequence control method and system. Background technique [0002] The stability problem is the biggest problem of AC transmission system. With the expansion of the grid scale and the increasing number of regional interconnections, various uncertain operating variables and complex disturbance factors in the system interfere with each other and affect each other, which can easily cause a large swing in the power of the tie line, which significantly increases the probability of transient instability in the system , which brings great risks to the safe and stable operation of the system. When the system is disturbed and unstable, the commonly used emergency control measures include machine cutting, load shedding, low-frequency load shedding, and out-of-step splitting. On the one hand, out-of-synchronization decoupling is u...

AI Technical Summary

Problems solved by technology

With the expansion of the grid scale and the increasing number of regional interconnections, various uncertain operating variables and complex disturbance factors in the system interfere with each other and affect each other, which can easily cause a large swing in the power of the tie line, which significantly increases the probability of transient instability in the system , which brings a great risk to the safe and stable operation of the system

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