Voltage stability evaluation method with consideration of load growth and new energy output randomness

Abstract

The invention, which belongs to the technical field of the power system stability analysis and control, discloses a voltage stability evaluation method with consideration of load growth and new energyoutput randomness. With consideration of the influence on the voltage stability evaluation by load growth and new energy output randomness, the invention provides a voltage stability evaluation method to convert an uncertain problem into several deterministic problems for solution. According to the method, on the basis of historical load data, load nodes are classified by using an improved K-means clustering algorithm; expectation of random load growth is defined based on a load prediction result; according to a load growth direction and probability distribution of wind power and photovoltaicoutputs, a load growth direction and a power output sample are obtained by using Latin hypercube sampling; and then with a continuous power flow, deterministic voltage stability load margin calculation is carried out on all samples to obtain statistical characteristics of the margin, and thus a probability evaluation result is obtained.

Description

technical field [0001] The invention relates to a voltage stability evaluation method considering load growth and new energy output randomness, and belongs to the technical field of power system stability analysis and control. Background technique [0002] At present, the voltage stability evaluation system based on determinism has matured, but there are many random factors in the actual operation of the power grid, especially in recent years, wind power, photovoltaic and other new energy units have been connected to the grid, making deterministic research unable to meet the random changes of the system. Require. Therefore, it is of great significance to study the voltage stability evaluation method considering random factors for the safe and stable operation of the system. [0003] Methods for assessing voltage stability taking into account load variations, power output, and component failures are well studied. It is of great engineering practical significance to study th...

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Problems solved by technology

The main problem in the current research on the uncertainty of load growth is that it is difficult to define the expectation of load growth, and the existing definition methods lack practical significance

Literature 1 "Static Voltage Stability Risk Assessment Based on Load Uncertainty Modeling" (Proceedings of the Chinese Society for Electrical Engineering, 2016, Vol. 36, No. 13, Page 3471) considers the randomness of load growth, and uses normal distribution to simulate random growth, by classifying the load-increasing nodes to consider the different growth modes of various nodes, but the expectation of random growth of each node is that the base state load value of the node is not practically meaningful

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