Security risk assessment method of wind-power-included electric power system based on Gaussian mixture distribution characteristics

Abstract

The invention relates to a security risk assessment method of a wind-power-included electric power system based on Gaussian mixture distribution characteristics. The security risk assessment method comprises the following steps: counting up the distribution of historical data of output power of a wind power plant; establishing a non-parameter probability distribution model of the output power of the wind power plant; establishing a Gaussian mixture distribution model of the output power of the wind power plant; determining the quantity of Gaussian distribution and initializing parameters of each Gaussian distribution; solving the parameters of each Gaussian distribution and determining the Gaussian mixture distribution characteristics; determining cumulative distribution functions of state variable node voltage and branch power flow; and calculating state variable threshold-crossing probability and severity of generated results, and comprehensively estimating safety risks of the electric power system. According to the security risk assessment method provided by the invention, a semi-invariant solving process of node injection power of the system is greatly simplified, so that the efficiency of semi-invariant calculation of the node injection power and the accuracy of the cumulative distribution functions of state variable node voltage and the branch power flow are improved, and thus effective data supports are provided for security risk assessment of the electric power system.

Description

technical field [0001] The invention relates to the field of power system operation and control, in particular to a safety risk assessment method for power systems containing wind power based on Gaussian mixture distribution characteristics. Background technique [0002] With the rapid economic development and increasingly severe environmental pressure, the operating environment of the power grid presents new characteristics, especially the large-scale grid-connected wind power, which brings new challenges to the safe operation of the power system. [0003] Power flow analysis is the basis and premise of power system safety assessment. Using the probabilistic power flow calculation method, considering random factors such as wind power output fluctuations, and establishing a mathematical model representing system uncertainty through probability theory, it can more comprehensively reflect the operating conditions of the power system, and Discover potential risks and vulnerabil...

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Problems solved by technology

[0005] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a safety risk assessment method for power systems containing wind power based on Gaussian mixture distribution characteristics, which converts the probability density of non-normal wind farm output power into a typical Gaussian mixture distribution, not only can accurately quantify the probability distribution of wind farm output power, but also greatly simplifies the process of obtaining the semi-invariant of the system node injection power, and makes up for the single defect of the method used to solve the semi-invariant in the traditional probabilistic power flow calculation, further improving the The efficiency of the semi-invariant calculation of node injected power and the accuracy of the cumulative distribution function of the state variable node voltage and branch power flow provide effective data support for the safety risk assessment of power system voltage violation and branch power flow overload

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