Power grid out-of-step disconnecting control system and method

Abstract

The invention provides a power grid out-of-step disconnecting control system and method, and belongs to the field of power system stability control. Based on out-of-step judgment of a regional power grid, an out-of-step situation of the regional power grid is judged step by step, so that the invention provides more comprehensive consideration; based on out-of-step judgment of a large-area power grid, the influence of out-of-step of the regional power grid is considered, and the possibility of power failure of a local power grid is reduced; furthermore, the out-of-step judgment method provided by the invention effectively locates a line where an out-of-step center is located, and performs a disconnecting operation on the line where the out-of-step center is located; when a system generates serious out-of-step oscillation, the power grid is quickly disconnected, the disconnecting measure is quickly and reasonably utilized in a first period of the out-of-step, and the out-of-step fault is prevented from spreading over the whole power grid; by inducing a wide-area measurement technique and utilizing a PMU device, electric data of the power grid is measured in real time on-line, communication is performed by utilizing the optical fiber communication technology, and a main grid control center judges the out-of-step of the power grid, controls the whole power grid and ensures that the power grid is reliably disconnected when the power grid occurs the out-of-step.

Description

technical field [0001] The invention belongs to the field of power system stability control, and in particular relates to a power grid out-of-step splitting control system and method. Background technique [0002] The power system has entered the era of large power grids, high voltage and large units. With the strengthening of society's dependence on power resources, the power system has become increasingly large and complex. The development of power systems is facing opportunities and challenges. The safety of large power systems The requirements for stable operation are getting higher and higher. Several major power outages over the years have shown that ensuring the safe and stable operation of the power system and preventing large-scale power outages is an urgent and important task for the modern power system. Losses caused by power outages require effective judgment of the out-of-synchronization situation of the system, and decoupling measures should be taken for the ou...

AI Technical Summary

Problems solved by technology

At present, a large part of the reason for the occurrence of large-scale blackouts is the improper configuration of the third line of defense, which cannot effectively judge the out-of-synchronization situation of the system, and cannot accurately locate the line where the oscillation center is located, so the research is applicable to large-scale In large-scale interconnected power systems, an accurate and fast out-of-step and decoupling judgment method has great practical significance; there are four main types of out-of-synchronization and decoupling criteria: the first category is to directly measure the voltage phase angle difference at both ends of the tie line The second category is the criterion that indirectly reflects the power angle; the third category is the out-of-step criterion using the equal-area rule; the fourth category is the composite criterion formed by combining the advantages of each criterion;

[0004] The first type of criterion requires high measurement accuracy and there is a problem of communication delay, which is only valid when the oscillation center is located between the two busbars; the second type of criterion can only be judged when the system grid is obviously out of step, and cannot Satisfy the requirements of fast decoupling of some power grids; the third type of criterion is relatively large for the sending-end system and relatively weak for the receiving-end system, a large disturbance may cause a serious drop in the voltage of the receiving-end system, if the drop in the opposite-end voltage is not taken into account , the equal-area criterion may produce certain errors; the fourth type of criterion is a major challenge for current research on how to better combine the advantages of each criterion to construct a new composite out-of-step separation criterion;

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