A fast assessment method for transient stability of super large city power grid based on dynamic security domain

Abstract

The present invention relates to a method for quickly assessing the transient stability of a super-large city power grid based on a dynamic security domain. Its technical features include the following steps: Step 1. Determine the system data under the potential operating mode of the system to form a system differential algebraic equation; Step 2. According to the system power flow section under the large-scale operation mode, screen heavy-duty lines and substations, and supplement high-power nodes, solve the pre-fault balance point and form a large-disturbance expected accident set; Step 3. Generate a transient stability evaluation scenario set Post-number the evaluation scenarios and start the dynamic safety domain evaluation; step 4, determine the countermeasures and fault response time for the expected accident, search for the critical equilibrium point of transient stability, and calculate the dynamic safety domain of each transient stability evaluation scenario ; Step 5. Evaluate the system's transient stability of the power grid after the expected accident and calculate the stability margin. The invention can shorten the evaluation time of the transient stability of the system and can provide a stability margin.

Description

technical field [0001] The invention belongs to the technical field of power grid transient stability margin evaluation, and relates to a method for quickly evaluating power grid transient stability margin, in particular to a method for quickly evaluating transient stability of a super-large city power grid based on a dynamic security domain. Background technique [0002] The security and stability of the power grid is still the primary issue of power production and operation, and cannot be taken lightly at any time. The three lines of defense are the successful experience in ensuring the safe and stable operation of my country's power grid. The construction of the three lines of defense is continuously strengthened, and various stability control devices and safety automatic devices are matched and improved to prevent the chain reaction of accidents, prevent serious damage to the main equipment, and effectively avoid major accidents. Power outage accidents ensure national sec...

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Problems solved by technology

[0003] In view of the situation of large-scale urban power grids subjected to large disturbances, especially the new elements faced in recent years, existing studies often use numerical integration methods to simulate specific faults / fault sets at a given system operating point, and according to This method has serious defects: 1) When the operating point of the system changes, it is necessary to re-run the simulation, which affects the judgment speed of the transient stability of the system, and it is difficult to meet the requirements of online applications; 2) ) Although the stability of the system can be judged through simulation, it cannot give the system stability margin index, which is not conducive to the system operation dispatcher to take appropriate control measures in time; 3) Although based on the historical operation experience, the transient stability of the system can be Make judgments and provide preventive control or corrective control measures, but under new elements such as the injection of large-capacity power (such as UHV substations), operating experience will be difficult to play a role

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