Improved neutral point grounding device for tubular hydraulic generator

Abstract

The invention relates to an improved neutral point grounding device for a tubular hydraulic generator and belongs to the technical field of hydraulic generator manufacturing. The device comprises a stator base, a water base ring, a three-phase neutral point lead device, a current mutual inductance device, a short-circuit copper bar and a zinc oxide arrester. The three-phase neutral point lead wire device is electrically connected with the current mutual inductance device, the current mutual inductance device end is connected with one end of the zinc oxide arrester through the short-circuit copper bar, the other end of the zinc oxide arrester is connected with the ground, and the output end of the current mutual inductance device is connected with an external monitoring device through a secondary lead wire of a mutual inductor. According to the improved neutral point grounding device for the tubular hydraulic generator of the invention, the zinc oxide arrester is grounded to form a high-resistance grounding mode, and when the generator has a single-phase grounding fault, the generator is quickly switched off, so that the damage to the generator and primary and secondary electrical equipment is avoided, and the reliability of a voltage system of the generator is improved; the neutral point grounding device is installed in bulb tubular hydroelectric generating set equipment, so that the installation is convenient, and the cost is saved.

Description

technical field [0001] The invention belongs to the technical field of hydraulic generator manufacturing, and in particular relates to an improved neutral point grounding device of a tubular hydraulic generator. Background technique [0002] When a single-phase ground fault occurs in the stator winding of the generator, the current flowing through the ground point is the three-phase-to-ground capacitive current of the motor body and its lead-out circuits (main busbar, plant branch line, low-voltage side of the main transformer, etc.). When the allowable value is exceeded, the stator core and winding insulation will be burned, which will cause inter-turn and inter-phase short circuits. Therefore, the large-scale generator sets in our country adopt the measures of high-impedance grounding through the arc suppressing coil or the distribution transformer at the neutral point of the generator to protect the motor from damage. [0003] However, for small and medium-sized hydroele...

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Problems solved by technology

[0005] The purpose of the present invention is to provide an improved neutral point grounding device of a tubular hydroelectric generator to solve the technical problem of structural reliability of the neutral point grounding device in the prior art

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