Nuclear power plant generator injection type stator grounding protection dynamic test method and device

Abstract

The invention discloses a nuclear power plant generator injection type stator grounding protection dynamic test method and device. With the method and device adopted, the technical problem of high risk of an existing conventional dynamic test can be solved. The dynamic test method includes the following steps that: S1, a stator grounding protection device exits under control so as to be not used; S2, a resistance value-adjustable test resistor is connected between the neutral point of the stator winding of a generator and ground before excitation boosting when the generator is a no-load state, and the grounding of the stator winding is simulated; S3, the stator grounding protection device is put into use under control, and excitation boosting achieves preset voltage under control, and maintains stable operation; and S4, measuring resistor sampling testing is carried out through the stator grounding protection device, and the protection parameters of the stator grounding protection device can be adjusted based on sampling testing results, and therefore, sampling accuracy can assuredly satisfy preset requirements, and detection and correction of the protective performance of the stator grounding protection device can be realized. With the method and device adopted, test risks such as electric shock of testers, false grounding of operating equipment and inaccurate measurement of the test resistor can be avoided.

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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