An optimal control method and system for ensuring the direction of primary frequency modulation action

Abstract

The invention discloses an optimizing control method and system capable of ensuring the motion direction of primary frequency modulation. When a power grid frequency deviation signal [delta]f exceeds a frequency modulation dead zone + / -0.03Hz provided by the state grid but does not reach a regional power grid dispatching assessment motion frequency threshold, machine set coordination control and digital electrohydraulic control respectively keep an original motion direction and amplitude; when the power grid frequency deviation signal [delta]f not only exceeds the frequency modulation dead zone + / -0.03Hz provided by the state grid but reaches the regional power grid dispatching assessment motion frequency threshold, the machine set coordination control and the digital electrohydraulic control respectively keep the original motion direction and amplitude, and shutting increase or shutting decrease is determined according to the frequency deviation size. According to the invention, the variation direction of a machine set load in the primary frequency modulation process, caused by the power grid frequency fluctuation, is ensured, a power reversed-modulation phenomenon is avoided, the frequency modulation performance of the machine set is improved effectively, the response accuracy of the thermal power machine set to the primary frequency modulation dispatching is improved, the motion qualified rate is increased, and the frequency fluctuation of a power grid system is reduced.

Description

technical field [0001] The invention relates to the field of frequency regulation of thermal power units, in particular to an optimal control method and system for ensuring the direction of primary frequency regulation. Background technique [0002] With new energy connected to the grid, load growth and the scale of the grid continue to increase, under the new situation of the interconnection of the UHV grid and the regional grid, the connection between the grids at all levels is becoming increasingly close, and the requirements for coordination and cooperation between the grid and the unit are also increasing. The higher the value, the primary frequency modulation in the coordination function of the factory network becomes one of the effective means to stabilize the power grid. The primary frequency regulation function of the generator set is an inherent function of the turbogenerator set. It is mainly through adjusting the steam inlet control door of the DEH system and usi...

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Problems solved by technology

[0005] Since the power plant unit uses the power value measured by the power transmitter for load control, and the power value sent by the PMU is used for the grid assessment, there is a small difference between the two; at the same time, although the State Grid stipulates that the dead zone of the frequency modulation action is ±0.033 Hz, but the specific limit value of the frequency modulation assessment of the power grid in each region is different. The frequency difference value for assessing the frequency modulation action effect is generally higher than ±0.033Hz. In an actual frequency modulation assessment, the moment when the frequency exceeds the assessment dead zone often occurs. There is a small reverse adjustment phenomenon in the power, resulting in the failure of the assessment index

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