Positive and negative pole change-over switch of excitation direct-current busbar of large steam turbine generator

Abstract

The utility model discloses a positive and negative pole change-over switch for excitation direct current busbars of a large-scale steam turbine generator. The positive and negative pole change-over switch comprises two rotor winding busbars which are arranged in parallel and two excitation power supply busbars which are arranged in parallel, the two rotor winding busbars are located between the two excitation power supply busbars and are disconnected from each other without contact, and the rotor winding busbars are perpendicular to the excitation power supply busbars; the two-phase back sides of the two rotor winding busbars are each provided with at least one single-pole double-throw switch, the movable ends of the single-pole double-throw switches are electrically connected with the rotor winding busbars, and the two fixed ends of the single-pole double-throw switches are correspondingly and electrically connected with the two excitation power supply busbars respectively. The generator rotor slip ring is simple in structure, realizes positive and negative polarity conversion of a generator rotor winding, ensures uniform electrolytic wear of the generator rotor slip ring, solves the problem that one slip ring is high in wear and the other slip ring is low in wear, prolongs the service life of the generator slip ring, and has good economic benefits.

Description

Technical Field

[0001] The utility model relates to the technical field of generators, in particular to a positive and negative pole conversion switch for an excitation DC busbar of a large steam turbine generator. Background Art

[0002] The excitation DC power of the steam turbine generator is transmitted to the rotor winding through carbon brushes and slip rings. Under the action of DC power, the slip rings and carbon brushes will produce electrolytic corrosion, which will cause the negative slip ring to wear less in the long term. There will be a problem of one slip ring suffering from transitional electrolytic wear and the other not wearing. The slip ring suffering from transitional electrolytic wear has a short service life. Most of the current domestic power plants are not equipped with DC busbar positive and negative pole conversion switches because of insufficient awareness of its importance, which needs to be improved. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the existing defects and provide a positive and negative pole conversion switch for the excitation DC busbar of a large steam turbine generator. The switch has a simple structure, realizes the positive and negative polarity conversion of the generator rotor winding, ensures uniform electrolytic wear of the generator rotor slip ring, solves the problem of large wear of one slip ring and small wear of the other, extends the service life of the generator slip ring, has good economic benefits, and can effectively solve the problems in the background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a positive and negative pole conversion switch of a large steam turbine generator excitation DC busbar, comprising two parallel rotor winding busbars and two parallel excitation power supply busbars; the two rotor winding busbars are located between the two excitation power supply busbars and are disconnected from each other and do not contact each other, and the rotor winding busbar is perpendicular to the excitation power supply busbar; at least one single-pole double-throw switch is provided on the back sides of the two phases of the two rotor winding busbars, the moving end of the single-pole double-throw switch is electrically connected to the rotor winding busbar, and the two fixed ends of the single-pole double-throw switch are respectively electrically connected to the two excitation power supply busbars.

[0005] Preferably, a transition busbar is provided on the back side of the two phases of the two excitation power supply busbars, and the fixed end of the single-pole double-throw switch is electrically connected to the transition busbar.

[0006] Preferably, an insulating fixing block is provided between the two excitation power busbars, the transition busbar is a groove-type structure, the transition busbar, the excitation power busbar and the insulating fixing block are connected by locking bolts, the transition busbar and the excitation power busbar are both provided with through holes for the locking bolts to pass through, and the insulating fixing block is provided with a threaded blind hole adapted to the locking bolts.

[0007] Preferably, insulating spacers are provided between the two rotor winding busbars and the insulating fixing blocks.

[0008] Preferably, one of the two rotor winding busbars is a positive busbar and the other is a negative busbar; one of the two excitation power supply busbars is a positive busbar and the other is a negative busbar.

[0009] Compared with the prior art, the utility model has the following beneficial effects: a transition busbar is added to the two excitation power busbars, at least two single-pole double-throw switches are provided, the moving end of the single-pole double-throw switch is electrically connected to the rotor winding busbar, and the two fixed ends of the single-pole double-throw switch are electrically connected to the two transition busbars respectively, and the connection relationship between the two rotor winding busbars and the two excitation power busbars is changed by switching the single-pole double-throw switch to achieve the positive and negative polarity conversion of the generator rotor winding. In practice, the conversion can be performed once a year to ensure uniform electrolytic wear of the generator rotor slip ring, solve the problem of large wear of one slip ring and small wear of the other, extend the service life of the generator slip ring, and have good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of the utility model;

[0011] Figure 2 It is a side view of the utility model.

[0012] In the figure: 1 rotor winding busbar, 2 transition busbar, 3 insulation fixing block, 4 excitation power supply busbar, 5 single-pole double-throw switch, 6 locking bolt, 7 insulation spacer. DETAILED DESCRIPTION

[0013] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction.

[0014] See also Figure 1-2The utility model provides a technical solution: a positive-negative pole conversion switch of a large steam turbine generator excitation DC busbar, comprising two parallel rotor winding busbars 1 and two parallel excitation power busbars 4; the two rotor winding busbars 1 are located between the two excitation power busbars 4 and are disconnected from each other and do not contact each other, and the rotor winding busbar 1 is perpendicular to the excitation power busbar 4; at least one single-pole double-throw switch 5 is provided on the back side of the two phases of the two rotor winding busbars 1, the moving end of the single-pole double-throw switch 5 is electrically connected to the rotor winding busbar 1, and the two fixed ends of the single-pole double-throw switch 5 are respectively electrically connected to the two excitation power busbars 4; one of the two rotor winding busbars 1 is a positive busbar and the other is a negative busbar; one of the two excitation power busbars 4 is a positive busbar and the other is a negative busbar;

[0015] Since the moving end of the single-pole double-throw switch 5 is electrically connected to the rotor winding busbar 1, and the two fixed ends of the single-pole double-throw switch 5 are electrically connected to the two excitation power supply busbars 4 respectively, that is, by switching the two single-pole double-throw switches 5, the electrical connection relationship between the two rotor winding busbars 1 and the two excitation power supply busbars 4 can be changed, thereby realizing the positive and negative polarity conversion of the generator rotor winding. In practice, the conversion can be performed once a year to ensure uniform electrolytic wear of the generator rotor slip ring, solve the problem of large wear of one slip ring and small wear of the other, extend the service life of the generator slip ring, and have good economic benefits;

[0016] Furthermore, a transition busbar 2 is provided on the back side of the two phases of the two excitation power supply busbars 4, and the fixed end of the single-pole double-throw switch 5 is electrically connected to the transition busbar 2. The main function of the transition busbar 2 is to install the fixed end of the single-pole double-throw switch 5;

[0017] Furthermore, an insulating fixing block 3 is provided between the two excitation power busbars 4, and the two excitation power busbars 4 are blocked and fixed by adding the insulating fixing block 3. The transition busbar 2 is a groove-type structure, and the transition busbar 2, the excitation power busbar 4 and the insulating fixing block 3 are connected by locking bolts 6. The transition busbar 2 and the excitation power busbar 4 are provided with through holes for the locking bolts 6 to pass through, and the insulating fixing block 3 is provided with a threaded blind hole adapted to the locking bolts 6, which is convenient for disassembly and installation; in addition, insulating pads 7 are provided between the two rotor winding busbars 1 and the insulating fixing blocks 3, and similarly, the two rotor winding busbars 1 are blocked and fixed by the insulating pads 7 and two insulating pads 7, and the insulating pads 7 of appropriate width may be required according to the spacing between the two rotor winding busbars 1;

[0018] It should be noted that, since the current of the excitation power busbar 4 of the large steam turbine generator can reach 3000-8000A, in order to ensure safety, a plurality of single-pole double-throw switches 5 need to be provided for electrical connection and switching operations according to actual circumstances.

[0019] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended to include all changes that fall within the meaning and scope of equivalent elements in the content of the present invention.

Claims

1. A positive and negative pole conversion switch for a large steam turbine generator excitation DC busbar, characterized in that: The invention comprises two parallel rotor winding busbars (1) and two parallel excitation power supply busbars (4); the two rotor winding busbars (1) are located between the two excitation power supply busbars (4) and are disconnected from each other and do not contact each other, and the rotor winding busbars (1) are perpendicular to the excitation power supply busbars (4); at least one single-pole double-throw switch (5) is provided on the two-phase back sides of the two rotor winding busbars (1), the moving end of the single-pole double-throw switch (5) is electrically connected to the rotor winding busbars (1), and the two fixed ends of the single-pole double-throw switch (5) are respectively electrically connected to the two excitation power supply busbars (4).

2. The positive and negative pole conversion switch of the excitation DC busbar of a large steam turbine generator according to claim 1 is characterized in that: A transition busbar (2) is provided on the back sides of the two phases of the two excitation power supply busbars (4), and the fixed end of the single-pole double-throw switch (5) is electrically connected to the transition busbar (2).

3. The positive and negative pole conversion switch of the excitation DC busbar of a large steam turbine generator according to claim 2 is characterized in that: An insulating fixing block (3) is provided between the two excitation power busbars (4); the transition busbar (2) is a slot-shaped structure; the transition busbar (2), the excitation power busbar (4) and the insulating fixing block (3) are connected via locking bolts (6); the transition busbar (2) and the excitation power busbar (4) are both provided with through holes for the locking bolts (6) to pass through; and the insulating fixing block (3) is provided with a threaded blind hole adapted to the locking bolts (6).

4. The positive and negative pole conversion switch of the excitation DC busbar of a large steam turbine generator according to claim 3 is characterized in that: Insulating pads (7) are provided between the two rotor winding busbars (1) and the insulating fixing block (3).

5. The positive and negative pole conversion switch of the excitation DC busbar of a large steam turbine generator according to claim 1 is characterized in that: One of the two rotor winding busbars (1) is a positive busbar and the other is a negative busbar; one of the two excitation power supply busbars (4) is a positive busbar and the other is a negative busbar.

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