Water turbine governor frequency measurement method and device based on image recognition technology

Abstract

The invention discloses a water turbine governor frequency measurement method and device based on an image recognition technology. The method comprises the steps of firstly collecting black and white toothed belt image information on a water turbine main shaft through a camera; performing image analysis processing through an image processing device by using an image recognition technology, and acquiring black and white gray scale changes of a video image acquired by a camera when the water turbine main shaft rotates to generate a rectangular pulse waveform; finally, accurately calculating the rotating speed frequency of the water turbine speed regulator through a speed regulator controller according to the frequency of the pulse waveform, the number of teeth of the black and white toothed belt and the number of magnetic pole pairs of the generator. The water turbine governor frequency measurement method and device based on the image recognition technology are not prone to being affected by electromagnetic interference of the surrounding environment, installation is easy and convenient, maintenance is easy, and cost is low.

Description

technical field [0001] The invention relates to the technical field of hydraulic turbine governor detection, in particular to a method and device for measuring frequency of a hydraulic turbine governor based on image recognition technology. Background technique [0002] The turbine governor generally uses two methods of gear plate frequency measurement and PT residual pressure frequency measurement to measure the speed of the unit. In the low-speed stage of the start-up and shutdown process, the gear plate frequency measurement method is preferred, and the PT residual voltage frequency measurement method is preferred in the no-load or loaded state. The sprocket speed measurement method requires a toothed belt with metal convex teeth to be fixed on the main shaft of the turbine, and a metal detection sensor is arranged around the toothed belt for detection. The controller performs logic processing according to the measurement signal sent by the sensor, and calculates Turbine...

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Problems solved by technology

[0003] ①: The spacing between the convex teeth of the metal tooth belt is required to be equal, and the tooth surface is on a concentric circular surface, which requires high processing technology, and the processing accuracy is difficult to meet the standard requirements, and it is not easy to process

If the processing accuracy is not high, the frequency measurement accuracy of the turbine governor will not meet the standard

[0004] ②: The installation of the metal toothed belt is difficult, requiring the installation plane to be horizontal and the tooth surface to be on a concentric circular surface. The toothed belt surrounds the large shaft of the turbine firmly and will not slide down. It requires high installation technology and is not easy to install.

If the installation of the toothed belt is unqualified, the frequency measurement accuracy of the turbine governor will not meet the standard

[0005] ③: The installation position of the metal detection sensor has high requirements on the installation process, and it is not easy to install. The installation distance between the metal detection sensor and the metal tooth belt convex teeth must match the performance requirements of the sensor, and it is difficult to manually adjust

[0006] ④: Metal detection sensors are susceptible to electromagnetic interference from the external environment

[0007] The above problems reflect that the speed measurement method of the metal concave-convex toothed disc has high requirements on the processing and installation of the toothed belt and the performance of the sensor, which is not easy to install and maintain, and the device cost is high

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