Generator carbon brush replacement method

Abstract

The invention relates to the technical field of high-temperature gas cooled reactor generator carbon brush replacement, in particular to a generator carbon brush replacement method. A method for replacing a carbon brush of a generator comprises the following steps of: (1) cutting off power and preparing for disassembly; (2) disassembling the old carbon brush, and maintaining or replacing the old carbon brush; and (3) installing the maintained old carbon brush or new carbon brush, and performing pilot run monitoring. The invention provides a method for replacing a carbon brush of a generator, and aims to solve the problems that if the carbon brush of the generator is used for a long time, the carbon brush is rubbed down to cause overcurrent of other carbon brushes to cause a sparking phenomenon, and if the carbon brush is seriously used, the other carbon brushes are burnt out to cause accidents such as burning out of a rotor of the generator.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon brush replacement for high-temperature gas-cooled reactor generators, and specifically relates to a method for replacing carbon brushes of a generator. Background Art

[0002] The high-temperature gas-cooled reactor generator operates stably at a rated speed of 3000 rpm, with an outlet voltage of 18 kV, a frequency of 50 Hz, and a power factor of 0.85 (lagging). The outlet of the generator provides normal power for the excitation system through an excitation transformer. The rated voltage on the low-voltage side of the excitation transformer is 560 V, and it adopts a dry-type transformer with Y, d11 wiring, F-class insulation, a temperature rise not exceeding B-class, the winding material is copper, and it is cooled naturally or by forced air. The operating ambient temperature is -10°C to 50°C. The excitation transformer is connected to the generator outlet through a segregated phase enclosed bus, and the low-voltage side is connected to the excitation system through a common box bus. The excitation system adopts a self-excited static excitation system, with a rated no-load excitation voltage of 77 V, a rated no-load excitation current of 572 A, a rated load excitation voltage of 270 V, a rated load excitation current of 1750 A, a strong excitation multiple greater than 2.0, and the allowable strong excitation time should not be less than 10 seconds.

[0003] After the generator excitation is rectified, the excitation output DC current passes through the generator carbon brushes and slip rings to the generator rotor winding to provide excitation current for the generator. If the generator carbon brushes are used for a long time, the carbon brushes will be worn flat, causing overcurrent in other carbon brushes and resulting in arcing. In severe cases, other carbon brushes will be burned out, leading to accidents such as burning of the generator rotor. Summary of the Invention

[0004] In view of this, the present invention provides a method for replacing carbon brushes of a generator to solve the problems that if the generator carbon brushes are used for a long time, the carbon brushes will be worn flat, causing overcurrent in other carbon brushes and resulting in arcing, and in severe cases, other carbon brushes will be burned out, leading to accidents such as burning of the generator rotor.

[0005] In a first aspect, the present invention provides a method for replacing carbon brushes of a generator, including:

[0006] (1) Cut off the power supply and make preparations for disassembly;

[0007] (2) Remove the old carbon brushes and maintain or replace the old carbon brushes;

[0008] (3) Install the maintained old carbon brushes or new carbon brushes and conduct a trial operation for monitoring.

[0009] By maintaining or replacing the carbon brushes, the long-term use of the carbon brushes is avoided, thereby eliminating the possible accident problems caused by the long-term use of the carbon brushes.

[0010] In an alternative embodiment, during the disassembly preparation process, in the field discharge resistor cabinet of the excitation regulator, withdraw the generator rotor single-point grounding protection pressure plate, then lay an insulating pad inside the generator soundproof cover and wear insulating gloves.

[0011] In an alternative embodiment, when disassembling the old carbon brushes, first rotate the brush holder handle counterclockwise. After hearing a "click" sound, remove the carbon brush together with the brush holder from the brush rack; then rotate the brush holder clockwise to eject the excitation carbon brush from the brush holder.

[0012] In an alternative embodiment, check the wear condition of the carbon brushes on the brush holder and determine whether to grind the ejected old carbon brushes or replace them with new carbon brushes.

[0013] In an alternative embodiment, lay the bottom of the carbon brush flat, expose the brush braid from the top of the brush box, and use a tool to loosen the fastener on the carbon brush braid; remove the carbon brush together with the brush braid from the brush box, and grind the carbon brush with a contact area less than 80% after removal.

[0014] In an alternative embodiment, put the ground old carbon brush or new carbon brush into the brush box, and the spring is press-connected to the center position of the carbon brush contact section; hold the bottom of the carbon brush flat and move it up and down to sense that the spring pressure is uniform and there is no jamming.

[0015] In an alternative embodiment, use a tool to tighten the brush braid to the brush box through the fastener, and fix the carbon brush at the same time; insert the brush box and the brush holder into the brush rack and fix the brush holder on the brush box.

[0016] In an alternative embodiment, rotate the brush holder clockwise. After hearing a "click" sound, the installation of the carbon brush is completed.

[0017] In an alternative embodiment, operate for a period of time, observe whether there are any abnormal conditions during the operation of the new carbon brush or the ground carbon brush, and measure the carbon brush temperature and current at the same time.

[0018] In an alternative embodiment, in the field discharge resistor cabinet, restore the generator rotor single-point grounding protection pressure plate; after confirming that the generator rotor single-point grounding protection has been restored, the generator operates normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1Schematic diagram of a generator according to an embodiment of the present invention.

[0021] Explanation of reference numerals: 1. Brush holder; 2. Carbon brush; 3. Slip ring. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] The following describes the embodiments of the present invention in conjunction with Figure 1 , the embodiments of the present invention will be described.

[0024] A method for replacing the carbon brush of a generator includes the following steps:

[0025] (1) Cut off the power supply and make preparations for disassembly;

[0026] (2) Remove the old carbon brush and perform maintenance or replacement on the old carbon brush;

[0027] (3) Install the maintained old carbon brush or new carbon brush and conduct a trial operation for monitoring.

[0028] By maintaining or replacing the carbon brush, the long-term use of the carbon brush is avoided, thereby eliminating the possible accident problems caused by the long-term use of the carbon brush.

[0029] Among them, (1) Cut off the power supply and make preparations for disassembly:

[0030] ⅰ) During the preparation for disassembly, in the excitation regulator's field discharge resistor cabinet, withdraw the generator rotor one-point grounding protection pressure plate;

[0031] ⅱ) Then lay an insulating pad inside the generator soundproof cover and wear insulating gloves;

[0032] (2) Remove the old carbon brush 2 and perform maintenance or replacement on the old carbon brush 2:

[0033] ⅰ) When removing the old carbon brush 2, first rotate the handle of the brush holder 1 counterclockwise. After hearing a "click" sound, remove the carbon brush 2 together with the brush holder 1 from the brush rack;

[0034] ⅱ) Then rotate the brush holder 1 clockwise to eject the excitation carbon brush 2 from the brush holder 1;

[0035] ⅲ) Check the wear condition of the carbon brush 2 on the brush holder 1 and determine whether to grind the ejected old carbon brush 2 or replace it with a new carbon brush 2;

[0036] ⅳ) Place the bottom of the carbon brush 2 flat, expose the brush pigtail from the top of the brush box, and use tools to loosen the fasteners on the brush pigtail of the carbon brush 2;

[0037] ⅴ) Take out the carbon brush 2 together with the brush pigtail from the brush box, grind the carbon brush 2 with a contact area less than 80% after taking it out, or replace the carbon brush 2 with a contact area greater than or equal to 80%;

[0038] ⅵ) Put the ground old carbon brush 2 or new carbon brush 2 into the brush box from below, press the spring against the center of the contact section of the carbon brush 2, and tighten the brush pigtail fastening screw; Hold the bottom of the carbon brush 2 flat and move it up and down to sense that the spring pressure is uniform and there is no jamming;

[0039] ⅶ) Fix the carbon brush 2 with the help of tools;

[0040] ⅷ) Insert the brush box and the brush holder 1 into the brush rack, and fix the brush holder 1 on the brush box;

[0041] ⅸ) Rotate the brush holder 1 clockwise, and after hearing a "click" sound, the installation of the carbon brush 2 is completed;

[0042] (3) For the old carbon brush 2 or new carbon brush 2 after installation and maintenance, conduct a trial operation monitoring:

[0043] ⅰ) Run for a period of time, observe whether there are any abnormal situations in the operation of the new carbon brush 2 or the ground carbon brush 2, and at the same time measure the temperature and current of the carbon brush 2;

[0044] ⅱ) In the field discharge resistance cabinet, restore the generator rotor single-point grounding protection pressure plate;

[0045] ⅲ) After confirming that the generator rotor single-point grounding protection has been restored, the generator runs normally.

[0046] The "running for a period of time" in step (3) refers to 10 - 40 minutes, preferably 20 minutes. The measured temperature of the carbon brush 2 should be less than 80 °C, and the current of the carbon brush 2 should be less than 60 A. It should be noted that the carbon brushes of the generator and the slip rings are set in one-to-one correspondence, and the number of carbon brushes is at least two groups.

[0047] The method for replacing the generator carbon brush provided by the present invention has the following advantages: (1) By replacing the carbon brush, various problems that may occur due to wear and flattening after long-term use of the carbon brush are solved; (2) A standardized method for replacing the carbon brush is given, realizing standardized replacement. After on-site actual verification, the reliability of the carbon brush is better ensured, and it is applicable to high-temperature on-site environments.

[0048] Although the embodiments of the present invention are described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for replacing the carbon brush of a generator, characterized in that, Including: (1) Cut off the power supply and make preparations for disassembly; (2) Remove the old carbon brush (2) and perform maintenance or replacement on the old carbon brush (2); (3) Install the maintained old carbon brush (2) or new carbon brush (2) and conduct a trial operation for monitoring.

2. The method for replacing the generator carbon brush according to claim 1, wherein During the preparation process for disassembly, in the field discharge resistor cabinet of the excitation regulator, withdraw the generator rotor one-point grounding protection pressure plate, then lay an insulating pad inside the generator soundproof cover and wear insulating gloves.

3. The method for replacing the generator carbon brush according to claim 1, wherein When removing the old carbon brush (2), first rotate the handle of the brush holder (1) counterclockwise. After hearing a "click" sound, remove the carbon brush (2) together with the brush holder (1) from the brush rack; then rotate the brush holder (1) clockwise to eject the excitation carbon brush (2) from the brush holder (1).

4. The method for replacing the generator carbon brush according to claim 3, wherein Check the wear condition of the carbon brush (2) on the brush holder (1) and determine whether to grind the ejected old carbon brush (2) or replace it with a new carbon brush (2).

5. The method for replacing the generator carbon brush according to claim 4, wherein Place the bottom of the carbon brush (2) flat, expose the brush braid from the top of the brush box, and use tools to loosen the fasteners on the brush braid of the carbon brush (2); take out the carbon brush (2) together with the brush braid from the brush box, and grind the carbon brush (2) with a contact area less than 80% after taking it out.

6. The method for replacing the generator carbon brush according to claim 5, wherein, Put the ground old carbon brush (2) or new carbon brush (2) into the brush box, and press the spring at the center position of the contact section of the carbon brush (2); hold the bottom of the carbon brush (2) flat and move it up and down to sense that the spring pressure is uniform and there is no jamming.

7. The method for replacing the generator carbon brush according to claim 6, characterized in that, With the help of tools, tighten the brush braid on the brush box through fasteners, and at the same time fix the carbon brush (2); insert the brush box and brush holder (1) into the brush rack and fix the brush holder (1) on the brush box.

8. The method for replacing the generator carbon brush according to claim 7, characterized in that, Rotate the brush holder (1) clockwise. After hearing a "click" sound, the installation of the carbon brush (2) is completed.

9. The method for replacing the generator carbon brush according to claim 8, wherein Operate for a period of time, observe whether there are any abnormal conditions during the operation of the new carbon brush (2) or the ground carbon brush (2), and at the same time measure the temperature and current of the carbon brush (2).

10. The method for replacing the generator carbon brush according to claim 9, wherein, In the field discharge resistor cabinet, restore the generator rotor one-point grounding protection pressure plate; after confirming that the rotor one-point grounding protection has been restored, the generator operates normally.

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