A Method for Locating Oscillation Sources in Large-Scale Power Systems

Abstract

The invention discloses a method for locating an oscillation source used in a large-scale power system, which belongs to the field of power system stability analysis. The main steps include: first reading the angular velocity and active power measurement signals of multiple generators after a section of power system disturbance Then described signal is obtained variation; Utilize TLS-ESPRIT method to analyze above-mentioned variation, obtain the low-frequency oscillation parameter of each signal under different oscillation modes; Select the mode concerned again, under this mode active power , angular velocity for reconstruction; finally calculate the oscillation energy, if the energy slope of a certain generator is negative, the oscillation source of the unit can be determined. The method of the invention utilizes the actual measurement information of the PMU, and can reflect the real operating conditions of the system. At the same time, the method can be applied to a large-scale power system, and has high engineering practical value.

Description

technical field [0001] The invention relates to the field of power system stability analysis, in particular to a method for locating an oscillation source used in a large-scale power system. Background technique [0002] Low-frequency oscillation is a prominent problem that threatens the safe operation of power systems. Quickly and accurately locating negative damping units is of great significance to the analysis and control of low-frequency oscillations in the power grid. At present, the mechanism of low-frequency oscillation mainly includes negative damping mechanism and forced oscillation mechanism. The negative damping mechanism believes that the insufficient damping torque of the generator leads to the instability of the small disturbance power angle. The reason is that the negative damping generated by the high-magnification excitation amplification system offsets the inherent positive damping of the system, making the total damping of the system decrease or even beco...

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Problems solved by technology

The hybrid simulation method uses the real-time synchrophasor data and distribution mode information of the PMU unit to equivalent the power grid into several subsystems, and locates the subsystem containing the disturbance source by comparing the simulated curve with the measured curve, and then repeats the subsystem containing the disturbance source Subdivide into smaller subsystems, and finally determine the smallest subsystem with disturbance sources, but the decoupling method of the hybrid simulation method needs to be optimized to meet the on-site PMU layout, and the hybrid simulation method is not suitable for online positioning

[0004] The energy function method is widely used, but the theory of this method is derived based on a single-machine infinite system, and there will be large errors when applied to a multi-machine system. Therefore, for actual large-scale power systems, this method is not accurate enough

[0005] The waveform similarity method uses the similarity and time delay of the special form of the voltage traveling wave propagating to each node in the power grid during low-frequency oscillation to realize the location of the disturbance source. However, the actual power grid structure is complex, and the waveform The similarity method will produce a large error

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