Electric system oscillation source positioning method based on negative damping torque

Abstract

The invention discloses an electric system oscillation source positioning method based on negative damping torque. The method comprises the following steps: establishing a theoretical state matrix ofeach sampling according to angular speed variable quantity and power angle variable quantity unit and each unit system kinetic equation according to the sampling on angular speed variable quantity andpower angle variable quantity of a time sequence by each unit after the disturbance; performing local polynomial estimation on the theoretical state matrix of each unit, acquiring the estimation of state value derivative and the estimation of the state value; and acquiring an oscillation damping torque coefficient by utilizing nonlinear least squares according to the estimation of the state valuederivative, the estimation of the state value and the system kinetic equation of each unit; judging whether the oscillation damping torque coefficient of each unit is less than zero, if the oscillation damping torque coefficient of each unit is less than zero, regarding the corresponding unit as the oscillation source unit triggering the low-frequency oscillation. The low frequency oscillation source in a power grid can be accurately and quickly positioned by distinguishing the damping matrix coefficient under the oscillation condition.

Description

technical field [0001] The invention belongs to the technical field of electronic system safety analysis, and more specifically relates to a method for locating an oscillation source of a power system based on a negative damping torque. Background technique [0002] When the power system is running in a certain normal state, the state variables of the system have a steady-state value, but the power system is almost always affected by small disturbances, such as random changes in load or swings of overhead lines caused by wind. When the system is disturbed, its operating state will deviate from the original equilibrium point, and it will go through an oscillation process under the influence of mechanical damping and return to a stable equilibrium operating point. In this process, if the damping of the unit is insufficient or negatively damped, the low-frequency oscillation phenomenon of the power system will appear. These negatively damped units are called the oscillation sou...

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Problems solved by technology

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a power system oscillation source location method based on negative damping torque identification, which aims to solve the problem of insufficient damping of the generator in the time domain analysis of the nonlinear power system in the prior art. The problem that leads to the inability to quickly and effectively locate the oscillation source where the damped oscillation occurs

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