Method for positioning and suppressing ultralow-frequency oscillation disturbance source

Abstract

The invention discloses a method for positioning and suppressing an ultralow-frequency oscillation disturbance source. The method comprises the following steps of SS1, positioning an ultralow-frequency oscillation disturbance source unit; SS2, identifying the system low-order linear model of the disturbance source unit; SS3, providing the disturbance source unit with an additional damping controller, and optimizing the parameters of the additional damping controller by using an intelligent algorithm; and SS4: performing disturbance suppression by using the additional damping controller. The method for positioning the ultralow-frequency oscillation disturbance source is characterized by constructing a corresponding Hamilton expression according to a rotor motion equation, obtaining the energy change rate of each generator input into a power grid, and determining the ultralow-frequency oscillation disturbance source according to the energy variation amount input into the power grid. Themethod suppresses system ultralow-frequency oscillation, and improves the stability of small interference.

Description

technical field [0001] The invention relates to the field of power system control, in particular to a method for locating and suppressing an ultra-low frequency oscillation disturbance source. Background technique [0002] The traditional low-frequency oscillation refers to the oscillation frequency between 0.1 and 2.5Hz. The relative oscillation between the rotors of the generator caused by the insufficient damping of the system can be studied by the analysis method of small disturbance stability. However, in recent years, ultra-low frequency oscillations with an oscillation frequency lower than 0.1 Hz have successively appeared in the DC transmission system with a relatively high proportion of hydropower units. In March 2016, when China Southern Power Grid was conducting an asynchronous networking test in Yunnan, a frequency oscillation with a duration of 25 minutes and a period of 20s occurred. When ultra-low frequency oscillation occurs, the speeds of all generators in ...

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Problems solved by technology

When ultra-low frequency oscillation occurs, the speeds of all generators in the system will change synchronously, and the existing analysis methods cannot accurately locate the disturbance source of ultra-low frequency oscillation

At the same time, the study found that when the flexible straight line project in the Chongqing-Hubei area is put into operation, the Sichuan-Chongqing Power Grid will realize asynchronous networking with the Central China Power Grid, which is very similar to the situation in the Yunnan Power Grid, and there is also a risk of ultra-low frequency oscillation in the Sichuan-Chongqing Power Grid

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