Monitoring method for determining influence of speed regulating system on low-frequency oscillation damping

Abstract

The invention discloses a monitoring recognizing method for determining the influence of a speed regulating system of a prime motor on low-frequency oscillation, and aims at recognizing whether a positive damping or a negative damping is provided by the speed regulating system of the prime motor for oscillating during the oscillating process in order to provide a certain reference value for the stable operation of a power system. The method comprises the following steps: recognizing the oscillation damping by the TLS-ESPRIT (total least squares-estimation of signal parameters via rotational invariance techniques) method; determining a first included angle of the left and right variables of a motor rotor equation based on the damping ratio; measuring the local electromagnetic power and the rotating speed of a generator to obtain a second included angle between the rotating speed deviation and the active power deviation; comparing the two included angles to determine whether the positive damping or the negative damping is provided by the mechanical power deviation to the oscillation. The determining method is simple and efficient and assists an operator improving the stabilizing level of the power system.

Description

technical field [0001] The invention belongs to the technical field of power system stability analysis, and more specifically relates to a monitoring and identification method that can be used for online judgment of the influence of a prime mover speed control system on low-frequency oscillation damping. Background technique [0002] The prime mover speed control system is the power system of the generator, the most important component in the power system. For thermal power units, it is mainly composed of boilers, steam turbines, speed control systems and their actuators. For hydropower units, it is mainly composed of water diversion systems, water turbines, and speed control systems. system and its actuators. In the traditional process of analyzing low-frequency oscillations, weakly damped low-frequency oscillations in power systems are generally considered to be caused by the high-gain and fast-response excitation system providing negative damping torque to the system duri...

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Problems solved by technology

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to provide a monitoring method for judging the influence of the speed control system on low-frequency oscillation damping, aiming to solve the problem that the speed control system may provide negative damping to the low-frequency oscillation in the low-frequency oscillation found through the online measurement. , which is not conducive to the situation where the oscillation subsides, so that the oscillation damping can be improved by stopping a frequency modulation, helping the oscillation to subside faster

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