Method used for identifying area being weak in voltage stability of power grid

Abstract

The invention relates to a method used for identifying an area being weak in voltage stability of a power grid. On the basis of a traditional modal method, the inaccuracy caused by great influences of active power for Jacobian matrix characteristic values of a system at a power grid running limit state is considered, and a full-voltage modal analysis method with the active power being considered is provided. A weak node acquired according to the method when the stability margin is very small or the system operates at critical destabilization is more accurate. In addition, the method not only can determine the weak node, but also can a control branch and a motor which have a main effect on the current destabilization mode, so that key information is provided for compensation site and load shedding location selection; and valuable engineering guidance information for preventing and controlling voltage destabilization and ensuring safe and stable operations of the power grid.

Description

technical field [0001] The invention relates to the technical field of grid stability analysis, in particular to a method for analyzing weak areas of grid voltage. Background technique [0002] At present, the scale of the power system is constantly expanding, the network structure is becoming more and more complex, and the system is constantly developing in the direction of large units, large power grids, high voltage and long-distance power transmission. With the increase of load and unit capacity, and the improvement of users' requirements for power quality, higher requirements are put forward for the safe operation of the power grid. Taking into account the constraints of environmental and economic factors, the operation of the power system tends to be stable to the limit state to meet the demand for power. In recent years, voltage collapse accidents have occurred many times in power systems at home and abroad, leading to large-scale power outages and huge losses to soc...

AI Technical Summary

Problems solved by technology

[0004] However, the current research methods to determine the weak areas of grid voltage mainly include N-1 voltage scanning of the whole network to calculate the static stability margin and the single V-Q mode method to calculate the minimum eigenvalue participation factors of each node to find out which nodes or areas have relatively low voltage stability. Poor, the N-1 voltage scan of the whole network calculates the static stability margin active power margin index and reactive voltage sensitivity index

Although the former method is intuitive, simple and easy to be accepted by people, it has a large amount of calculation, provides less information and is only suitable for the constant power load model; in the latter, only the reactive power participation factor is considered, and the nodes only include load nodes, and the generator nodes are not considered. Participation and the influence of branch participation factors; and the traditional modal method only calculates the node participation factor of the current operating point

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