Markov theory-based stochastic stability analysis method of wind power-comprising electric power system

Abstract

The invention provides a Markov theory-based stochastic stability analysis method of a wind power-comprising electric power system. A wind speed Markov model and a stochastic dynamic model of a doubly-fed induction generator are established; a stochastic Markov dynamic model of a doubly-fed induction generator-comprising electric power system is established; and a criterion suitable for the stochastic Markov dynamic model of the system is proposed. Based on the stochastic Markov theory, the stochastic Markov dynamic model of the wind power-comprising electric power system is established to perform system stability analysis; the practical criterion for judging the system stochastic mean square stability is obtained based on the stochastic Markov dynamic model of the system, according to thedefinition of the system stochastic mean square stability and based on related knowledge of an M matrix; by virtue of the analysis method, limitations of a stochastic equation are overcome, and the dynamic behaviors of the wind power-comprising electric power system in a wind speed large-range stochastic fluctuation condition can be described more accurately; and the criterion deduced based on the system stochastic Markov dynamic model is higher in practicability, simpler and more concise, and wider in applicable range compared with other criterion.

Description

technical field [0001] The invention relates to a power system, in particular to a random stability analysis method of the power system. Background technique [0002] In recent years, with the rapid development of new energy power generation, more and more new energy power generation such as wind power and photovoltaics has been incorporated into the power system. The fluctuation and randomness of wind power output power greatly affect the stability of the power system. And power quality, poses a huge challenge to the safe and economical operation of modern power systems. [0003] Traditional power system analysis mostly uses ordinary differential equations to describe the dynamic behavior of the system, and analyzes its stability by solving the characteristic roots of the state equation. For the random disturbance phenomenon existing in the system, the Monte Carlo method is usually used to analyze the stability of the system by using the knowledge of probability and statis...

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Problems solved by technology

But fundamentally speaking, the Monte Carlo method is still a deterministic analysis method, which does not essentially describe the impact of random factors on the dynamic operation of the power system, and the probability and statistics method needs to generate a large number of scenarios, which requires a large amount of calculation, time-consuming and labor-intensive

[0004] In addition, some scholars use stochastic differential equations to describe the dynamic behavior of power systems under random disturbances, but for power systems including wind power, stochastic differential equations can only describe the dynamic behavior of system state variables under random disturbances Response, unable to describe the impact of wind power on the power system when the wind speed fluctuates in a wide range

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