DEH speed regulating function diagnosis method and system for load shedding condition

Abstract

The invention discloses a DEH speed regulating function diagnosis method and system for a load shedding condition. The method comprises the steps that after DEH hybrid simulation is conducted to achieve a full load, a grid-connection switch is disconnected, a load shedding simulation experiment is started, operation is conducted on input governor valve feedback and intercept valve feedback through a DEH rotating speed simulation logic module, and the simulation rotating speed of a steam turbine is output; an automatic ascending curve characteristic data acquisition logic module automatically collects the simulation rotating speed of the steam turbine, and the characteristic data of an ascending curve is captured automatically; meanwhile, the DEH electrical response time and hydraulic response time are worked out through an SOE system; a DEH speed regulating function self-diagnosis logic module receives characteristic data of the ascending curve and the DEH electrical response time and hydraulic response time and conducts DEH speed regulating function diagnosis step by step according to the preset priorities from high to low, diagnosis of each level has an independent voting right, diagnosis after voting becomes invalid, a voting result serves as a diagnostic conclusion, and key fault points abnormal in speed regulating function are output.

Description

technical field [0001] The invention belongs to the field of power generation, and in particular relates to a method and a system for diagnosing a DEH speed regulation function under load shedding conditions. Background technique [0002] Today's power grid scale is becoming increasingly large and power consumption is complex and changeable, resulting in various disturbances in the power system, and severe climate change and frequent natural disasters make the turbine generator set often face load shedding during operation. Rapid load shedding is the worst working condition. It involves all systems of machine, furnace and electricity. It has a great impact on the unit and directly endangers the safe and stable operation of the unit. [0003] For the operation of the steam turbine generator set, the most critical thing is to ensure that the speed of the unit quickly stabilizes to the rated speed after load shedding, so as to avoid the tripping of the steam turbine caused by t...

AI Technical Summary

Problems solved by technology

[0011] (1) In the traditional steam turbine speed simulation logic, the calculation of the flow rate is directly replaced by the opening of the control valve, without considering the factors of the flow characteristics of the control valve, resulting in poor linearity in the calculation of the steam inlet flow link

[0012] (2) The traditional speed simulation logic is an open loop, which does not consider the negative feedback effect of blast friction and bearing mechanical friction loss

[0013] (3) The speed is obtained by simple calculation of the first-order inertia and proportional links of the inlet steam flow. The calculated speed is far from the actual load rejection speed rise curve, which cannot meet the requirements of the automatic diagnosis system for speed simulation.

[0014] (4) The traditional DEH load shedding simulation test cannot realize the automatic collection and automatic processing of characteristic data after the DEH load shedding simulation test

Unable to realize all-round (including DEH electrical software, electrical hardware and hydraulic parts) automatic diagnosis after DEH load shedding simulation test, which may keep some hidden dangers hidden and always threaten the safe operation of the unit

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