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Discussion on the relationship between electrical speed and mechanical speed of speed governing systemDiscussion on the relationship between electrica

News by ninechip | On 2018-11-12 16:13
There is a very important test in the water-free test of the speed control system of a newly-built or renovated hydropower station. It is the premise and basis of the follow-up test. The quality of the test is directly related to the success of the load rejection test of the hydroelectric generating set. What kind of test is this?
   This test is the turn-on and turn-off time setting test of the speed governing system, referred to as the turn-on and turn-off test. It seems a very ordinary experiment, but its significance is very significant.
   First, let's briefly introduce the definition of the timing and opening time of the speed governing system. The so-called start-up time refers to the time required for the guide vane system to open from 0% to 100% under the hydraulic action of the relay of the speed governing system, and vice versa.
   Through the above brief description, the turn-on and turn-off time reflects the speed of the opening and closing movement of the guide vane and the wheel blade relay under the hydraulic control of the speed governing system, and the setting value of the speed is the theoretical value obtained by the hydroelectric survey and Design Institute (some are turbine manufacturers) through the adjustment calculation, which is used as the speed governing system. In the anhydrous test, it is the basis for adjusting the opening and closing time. As shown in Figure 1, it is the speed curve of a certain hydropower plant, whose slope is the speed of the guide vane closure.
   The speed governing system adjusts the nut by adjusting the main switching machine of the governor when setting the speed test of turning on and off, as shown in Figure 2. By adjusting the adjusting nut of the switch machine, the opening and closing speed of the speed regulating hydraulic system can meet the requirement of the adjusting and ensuring calculation speed. The method of measuring the speed is to make the main valve core of the governor move under the limit position of the adjusting nut of the switching machine (get the maximum oil flow window) by manually operating the hand wheel and the emergency stop valve of the governor, so that the secondary hydraulic amplification can drive the relay movement of the guide vane through the artificial operation. The speed that the operating machinery causes the relay to move is called the mechanical speed of the speed regulating system. It is the basic speed of the speed governing system, which is recorded as VM.
 
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