Research On Power System Low Frequency Oscillation Induced By Turbo-Power Changing

Electrical power system's stabilization is electrical power system's vital basic question, which direct relation lives of the people and national security. In the actual electrical power system movement process, the voltage, the merit angle, the line power vibration sometimes occur. In recent years, to enhance the electrical power system static stability and the voltage quality, but has introduced the fast excitation system massively, moreover made the human along with electrical power system networking advancement's quickening as well as the electric power market, electrical power system's scale to expand day by day, the movement tends more and more critical point, the electrical power system vibration question has become the electric power scholar universal matter of concern. The electrical power system is overall which constitutes by the electrical network and the power plant, inseparable, power plant boiler's dynamic characteristic and steam turbine velocity modulation system immediate influence generator's output, then influence overall system's running status. However the present research low frequency vibration often limits in the electrical network stratification plane, supposes the power plant output invariably to come to study the electrical system isolated. This and actual situation existence big error. Resonates the mechanism is one which of reasons the electrical power system low frequency vibration produces. Power system resonance mechanism is one of the reasons of low-frequency oscillation. In this paper, the author compared several simplified steam turbine model now widely used in power system stability analysis and proposed an improved pressure-power torbine model which can be used in power system simulation.The author also did some research by analyzing several common perturbation signal to find the affecttion when main steam pressure disturbance on the power system low frequency oscillation. The results showed that the amplitude and the frequency of a continuing system natural oscillation frequency with the same or similar single periodic disturbance can lead to continued weak damping power system oscillations contact line. In multi-machine case, the machine can produce disturbed by the superposition of the impact of transient oscillation and continuous oscillation significantly.