A method for evaluating the power grid's ability to resist centralized power shedding

Abstract

The invention provides a method for evaluating capability of a power grid for resisting concentric power falling off, comprising the following steps: dividing the power grid into several areas according to the geographic location, and taking the power system load flow calculation and transient stability calculation as base iterative computation; solving relationship between the power generation and load in each area according to the load flow calculation during every iterative computation, further performing dividing into three areas with different natures, namely, generation area, load area and supply balance area; and finding the generator set with the worst frequency response in the generation area by the transient stability calculation, repeatedly iterating till that the frequency of a power system does not meet the operation requirement, and ending. The evaluation method provided by the invention not only obtains capability of the power grid for resisting concentric power falling off quickly to a certain content, displays the falling combination and power of the worst set loaded by a power system and provides the decision base for the operation control operator of the power system, but also checks validity of the low-frequency load-down program of a complex power system.

Description

technical field [0001] The invention belongs to the technical field of power system safety and stability control, and in particular relates to a method for evaluating the ability of a power grid to resist centralized power shedding. Background technique [0002] At present, the power system is becoming more and more complex, the unit capacity is getting larger and higher, the voltage level is getting higher and higher, the transmission distance is getting longer and longer, and various new energy sources such as wind energy are also connected to the grid in large quantities. The possibility of chain jumping is also increased. These characteristics indicate that power systems are more susceptible to severe power deficits and present serious new challenges in maintaining frequency stability. [0003] At present, in the study of low-frequency load shedding setting schemes for single-machine with concentrated load model design and multi-machine system verification, there is a p...

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Problems solved by technology

[0003] At present, in the study of low-frequency load shedding setting schemes for single-machine with concentrated load model design and multi-machine system verification, there is a problem that the design scheme cannot predict the power shedding defense capability information, and this is precisely the concern of operators of complex power systems of

[0004] Conventional analysis, such as the N-1 principle analysis, cannot give enough information to judge the system's power shedding defense capability, and seek the complex power system's ability to deal with power shedding, that is, knowing how much off-line power the system can withstand can still ensure safety and stability Operation is very necessary for the current complex power system. However, the high-power shedding event of multiple units is a low-probability event. In addition, there are many ways of unit shedding in complex power systems and a large amount of calculation. At present, there are few power system multi-units. The research on high power shedding, and most of them are estimated and judged based on experience at present, but this has certain human-subjective factors. Knowing the ability of the power grid to resist concentrated power shedding can make up for this defect to a certain extent. Operational controllers provide decision-making basis

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