Study On Power System Forced Power Oscillation Taking Into Account Wind Power Disturbance

Dynamic analysis of power systems is an important content of power systemsecurity analysis. Low frequency oscillation is an important factor on affecting thepower system dynamic security. Wind power has the characteristics of randomicityand intermittent, etc. It is located on the weak links of the grid structure generally, sothe large scale wind power connected to grid will probably impact on power systemstability. With networking operation of the large scale wind power to, the dynamiccharacteristics of wind power which are different from the traditional energy willproduce new effects on the characteristics of low frequency oscillation.In this paper, we will consider the impact of networking operation of the largescale wind power on forced power oscillation which is a kind of low-frequencyoscillation. Based on the gust frequency range and energy characteristicsresearch.Through the derivation of the forced power oscillation mechanism, gustmathematical model and wind machine absorption mechanical power formula, it isproved that the gust disturbance source is a kind of multifrequency forced oscillationdisturbance source which is different from the conventional single frequencydisturbance source in theory. Using the application of forced power oscillationmechanism to theoretically calculate, the magnifying relation of the perturbationamplitude and the oscillation amplitude is illustrated. On the glorious trend of windpower, the paper verifies that the gust is a kind of resonant forced disturbance source.When the classical single machine infinite bus power system is subjected todifferent wind speed model, we found that the influence induced by the gustdisturbance on the system is the largest in the simulation software. Time domainsimulation results show that under the same disturbance doubly fed wind machine ismore stable than the squirrel cage induction wind machine when wind generator isconnected to the power system. When the gust disturbance frequency is consistentwith the system natural frequency, it is verified that the system emerged resonance in three machines-nine nodes (3-generator9-bus)system where asynchronous fan modelis established. When the system damping and the gust disturbance frequency arechanged, the amplitude of the oscillation will have different rate of change.