Generator power fluctuation suppression method and generator power fluctuation suppression control device

Abstract

The invention relates to a generator power fluctuation suppression method and a generator power fluctuation suppression and control apparatus. The method comprises the following steps: firstly acquiring the lowest phase voltage Up among the three phase voltages, the negative sequence voltage U2, the active power P1 and P2 outputted by the generator in two adjacent measurement periods, and the angular velocity [omega]1 and [omega]2 of the generator rotor in two adjacent measurement periods; and then, when the following conditions are satisfied wherein Up is smaller than Uset or U2 is greater than U2set and [delta]P is greater than [delta]pset, and [delta] [omega] is greater than [delta] [omega]set, controlling the DEH to switch to a manual mode to suppress the generator power fluctuation. [delta]P can be obtained by the deduction of P2 by P1; [delta] [omega] can be obtained by the deduction of [omega]2 by [omega]1, and Uset, U2set, [delta]pset and [delta] [omega]set are all given values. The suppression method provided by the invention can effectively prevent the jittering of a turbine generator DEH regulating valve for sudden emergencies, which further prevents the fluctuation of the outputted power from the generator and the occurrence of abortion accidents. The suppression apparatus can generate good economic benefits.

Description

technical field [0001] The invention relates to a generator power fluctuation suppression method and a generator power fluctuation suppression control device. Background technique [0002] At present, various faults in the power grid that are electrically close to the power plant or the startup of high-power loads will cause power fluctuations at the generator end, and such events often occur. For example, when a symmetrical fault or asymmetrical fault occurs in a place close to the electrical distance of the power plant, it is often accompanied by low voltage, high current, zero-sequence voltage and current or negative-sequence voltage and current. When the power grid fails, the output power of the generator will be reduced, and the electromagnetic power and the power of the steam turbine will be unbalanced, which will cause the DEH action to adjust the steam turbine valve to cause oscillation. The closer the electrical distance is, the greater the fault current, the great...

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Problems solved by technology

More generally, after the power fluctuation occurs, PSS provides positive damping to suppress the oscillation process. The suppression effect depends on the performance of the PSS device. At this time, if the DEH governor is affected by the power fluctuation feedback, the main The vibration of the air conditioning door can aggravate the imbalance of mechanical and electrical power, and even cause the PLU protection action of the steam turbine to cause the unit to trip

At present, there are no effective measures for power grid failure or high-power load start-up to cause steam turbine adjustment valve jitter and then cause generator output power fluctuations

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