Device for judging main distribution refusing action of speed adjuster of water turbine and measuring method

Abstract

The invention discloses a device for judging a main distribution refusing action of a speed adjuster of a water turbine. The device comprises a base plate, a sensor mounting bracket, an eddy current displacement sensor, a power supply control module, a simulation quantity input module and a rotating speed relay; the bottom end of the sensor mounting bracket is fixed on the base plate; the eddy current displacement sensor is fixed at the top end of the sensor mounting bracket through fixed bolts, and is connected with the power supply control module and the simulation quantity input module; theeddy current displacement sensor measures the displacement of a measured bracket to transmit to the simulation quantity input module; the simulation quantity input module transmits displacement signals to a monitoring lower computer PLC; the main distribution middle position and the main distribution opening direction maximum input are marked in the monitoring lower computer PLC; and the monitoring lower computer PLC reads three position signals of main distribution in real time to judge if the main distribution is in a non-related position, so that the problems of inaccurate position judgment of a main distribution valve element, continuous wrong report signals and failed judgment of the main distribution refusing action caused by a speed adjuster PLC main body are solved.

Description

technical field [0001] The invention relates to the technical field of hydroelectric power generation, in particular to a device and a measuring method for judging that the main equipment of a water turbine governor refuses to move. Background technique [0002] The danger of an overspeed accident of a hydroelectric generator set is very serious. The huge centrifugal force may cause the vibration and swing of the unit to increase sharply during overspeed, and may even cause the rotating part of the unit to collide with the fixed part, causing water damage. The turbine generator set is seriously damaged. In order to prevent the overspeed accident of the unit, hydropower stations generally set up three-level overspeed protection: the speed is greater than 115%Ne, and the position of the main valve core is wrong; the speed is greater than 140%Ne; mechanical overspeed protection device. The three-level protection will start the emergency shutdown process through the water machin...

AI Technical Summary

Problems solved by technology

The three levels of protection will start the emergency shutdown process through the water machine protection circuit

[0003] At present, there are basically two methods for judging the position signal of the main distribution spool for the first-level overspeed protection of each hydroelectric unit: the first is to judge through the external device of the micro switch or proximity switch, which is actually to judge whether the main distribution is in the off-off position or not. position, the contact will reset only when the main distribution valve moves in the direction of closing. Most of the time, the main distribution spool position signal will always be maintained, and the continuous sending of the action signal will cause the upper computer of the monitoring system to refresh the screen too quickly, causing the operation to fail. On the other hand, because the dead zone of the general limit switch is at least 2~4 mm, and the stroke of the general main pressure distribution valve is mostly 8~10 mm, the reliability of the limit switch is not high. , increasing the risk of protection misoperation

The second is to judge the position signal of the main distribution spool in the governor PLC. This method has the risk of failure. When the governor PLC fails and the main distribution spool is in a non-closed position, the protection will fail.

[0005] Therefore, it is necessary to propose a device and measurement method for judging that the main part of the turbine governor is refused to move, which can effectively improve the judgment accuracy, avoid false alarm signals that continue to cause the above-mentioned monitoring to quickly refresh the screen, and avoid main part rejection caused by the governor PLC body. Dynamic judgment failure problem

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