Dynamic test method and device for injection-type stator grounding protection of nuclear power plant generators

Abstract

The invention discloses a dynamic test method and device for injection-type stator ground protection of generators in nuclear power plants, which solves the technical problem of high risk in existing conventional dynamic tests. The dynamic test method includes: S1, controlling the stator ground protection device to withdraw from use ; S2. When the generator is in the no-load state and before the excitation boost, connect a test resistor with adjustable resistance between the neutral point of the generator stator winding and the ground to simulate the grounding of the stator winding; S3. Control the stator grounding protection The device is put into use, and the excitation voltage is controlled to be boosted to the preset voltage, and the operation is maintained stably; S4, the measurement resistance sampling test is carried out through the stator grounding protection device, and the protection parameters of the stator grounding protection device are adjusted based on the sampling test results to ensure that the sampling accuracy meets Preset requirements, so as to realize the detection and correction of the protection performance of the stator grounding protection device. Avoid or reduce test risks such as electric shock of test personnel, false grounding of operating equipment, and inaccurate test resistance measurement.

Description

technical field [0001] The invention relates to the technical field of nuclear power plant generator grounding protection, in particular to a dynamic test method and device for injection type stator grounding protection of nuclear power plant generators. Background technique [0002] Generators are important backup power equipment in nuclear power plants. There are many ways to protect generators in nuclear power plants. Among them, generator injection stator grounding protection is a commonly used protection method in nuclear power plants. Because when the generator stator winding is not grounded, the generator stator winding is a pure capacitive reactance to the ground, and when the generator stator winding is single-phase grounded, the generator stator winding is not a pure capacitive reactance to the ground and has a certain magnitude (such as 0~ 10k) resistance to ground. [0003] Injection-type stator grounding protection for generators in nuclear power plants is base...

AI Technical Summary

Problems solved by technology

[0008] (1) The test needs to be carried out after the generator has been boosted, and the tester needs to hold an insulating rod to connect to the primary high-voltage equipment of the generator. Although the insulating rod can ensure that the human body does not touch the high voltage, there are damages to the insulating rod and misuse of the high-voltage equipment. Accidents such as touching the grounded shell and unreliable contact of the insulating rod will increase the contact resistance. When these accidents occur, it will cause risks such as electric shock to the test personnel, wrong grounding of the operating equipment, and inaccurate test resistance measurement. The test risk is high;

[0009] (2) The tester needs to manually adjust the resistance of the resistance box, which increases the risk of electric shock for the tester;

[0010] (3) The test resistor is connected in the stator winding of the generator. If a real ground fault occurs in the stator winding of the generator during the test, two points of the stator winding of the generator will be grounded, which will damage the main electrical equipment and test equipment. No effective measures have been taken in the technology to avoid such situations;

[0011] (4) Since the injection-type stator grounding protection setting curve is a nonlinear change, the routine test only performs the verification test of the alarm and trip setting, and there are few sampling points for measuring resistance, which cannot truly reflect the change of the protection error

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