Method for determining critical stable value of grid connected thermal power generating unit primary frequency regulation rotating speed diversity factor

Abstract

The invention relates to a method for determining the critical stable value of the grid connected thermal power generating unit primary frequency regulation rotating speed diversity factor. The thermal power generating unit is a condensing turbine set, and is based on a one-machine infinite system. The method is characterized by comprising the following steps of S1, establishing a steam volume effect mathematical model; S2, establishing a turbine rotor mathematical model; S3, establishing a hydraulic servo-motor mathematical model; S4, solving the critical stable value of the thermal power generating unit primary frequency regulation non-linear model rotating speed diversity factor; S4, solving the critical stable value of the thermal power generating unit primary frequency regulation linear model rotating speed diversity factor; and finally obtaining a rotating speed diversity factor Delta formula which makes the system be stable. According to the invention, the linear model rotating speed diversity factor critical stable value is employed to substitute the non-linear model rotating speed diversity factor critical stable value to serve as the set reference value of the grid connected thermal power generating unit primary frequency regulation rotating speed diversity factor, the safety of the grid connected thermal power generating unit is considered, and stable operation and primary frequency regulation capability of the rid connected thermal power generating unit are considered at the same time. At the same time, the method for determining the critical stable value of the grid connected thermal power generating unit primary frequency regulation rotating speed diversity factor is simple in implementation method and high in precision.

Description

technical field [0001] The invention relates to a method for determining a critical stable value of a primary frequency modulation speed unequal rate of a grid-connected thermal power unit. Background technique [0002] In China, thermal power generation is the mainstay. The participation of thermal power units in primary frequency regulation and the ability of primary frequency regulation play a decisive role in maintaining the stability of power system frequency. For thermal power generating units, primary frequency regulation is an inherent feature, but it is a disturbance for the unit control system. Unreasonable system design or improper parameter setting will cause unstable operation of the boiler and steam turbine. At present, there are also some primary frequency modulation methods, but these methods all have the following disadvantages: In order to simplify the nonlinear characteristics of the unit, the commonly used analysis methods are mostly based on linear theo...

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Problems solved by technology

Unreasonable system design or improper parameter setting will cause unstable operation of the boiler and steam turbine

At present, there are also some primary frequency modulation methods, but these methods all have the following disadvantages: In order to simplify the nonlinear characteristics of the unit, the commonly used analysis methods are mostly based on linear theory

At present, the technical research on the primary frequency regulation of thermal power units is still immature, and there are few studies on the stable region of the primary frequency regulation of the steam turbine governor in power mode, and the current research results have not given a clear solution method for the stable region

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