Closing resistor structure for 800kV quick circuit breaker

Abstract

The invention relates to a closing resistor structure for an 800kV quick circuit breaker, which comprises a moving contact and a static contact, the moving contact is slidably connected in a guide cylinder, the guide cylinder is conductively connected with the moving end of an arc extinguish chamber of the circuit breaker, and the moving contact is connected with a main crank arm of the circuit breaker through a connecting rod assembly; on the basis that the original structure of the circuit breaker is not influenced, a closing resistor moving end transmission structure and the original circuit breaker structure are ingeniously combined, and the connecting rod assembly is invented, so that the stroke of a closing resistor part is basically consistent with that of the circuit breaker; a fixing structure is designed to fix the closing resistor at the lower part of the arc extinguish chamber, and a closing resistor insulation support cylinder structure is designed, so that the insulation capability is improved to the maximum extent on the basis of satisfying insulation support; the reliability improving structure of the closing resistor string crimping machine is designed to ensure the reliability of the closing resistor.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage switch fast circuit breakers, and in particular to a closing resistor structure for an 800kV fast circuit breaker. Background Art

[0002] In recent years, with the continuous development of my country's power construction, the continuous increase in electricity load, the application of low-impedance large-capacity transformers, the continuous increase in the capacity of power plants and generators, and the interconnection of large-scale power grids, the short-circuit current level in the power system has continued to increase. A large number of substations have short-circuit currents that have reached or even exceeded the circuit breaker interrupting capacity, seriously threatening the safe operation of the system.

[0003] The short-circuit current level of the AC power grid generally exceeds the interrupting capacity of the circuit breaker, and the problem of excessive short-circuit current in 220kV and 500kV AC power grids is prominent; the circuit breaker opening time is long, which has a great impact on the power grid system and endangers the safety of the power grid and equipment.

[0004] Existing short-circuit current suppression measures such as outage lines, busbar splitting, and installation of current limiters have many disadvantages, such as reduced power supply reliability, reduced transmission capacity, and increased losses. Moreover, current limiters of different topology schemes are large in size, complex in structure, and high in cost, which makes them difficult to promote and apply in ultra-high voltage power grids.

[0005] New short-circuit current suppression technology: Based on the key technology of fast breaking, the system topology is adjusted dynamically, and multiple feeder branches connected to the grid fault point are quickly isolated to achieve flexible suppression of grid short-circuit current, which can reduce the short-circuit level by more than 40%. According to the research on the control strategy of the new technology for suppressing grid short-circuit current, the fast-breaking circuit breaker should complete the system topology adjustment within the opening time of the conventional circuit breaker, and the rated short-circuit current full breaking time of the fast-breaking circuit breaker is ≤25ms, meeting the short-circuit current suppression requirements. The fast circuit breaker can effectively block the circuit breaker current and significantly reduce the level of the circuit breaker current, thereby improving the stability of the power grid system.

[0006] Suppressing the short-circuit current level of the power system is one of the effective means to maintain the stable operation of the power grid. The fast circuit breaker can quickly isolate the fault line and effectively reduce the short-circuit current level. Therefore, the fast circuit breaker can improve the stability of the power grid operation by isolating the fault line. Developing a fast circuit breaker that meets the requirements is of great significance to improving the stability of the power grid.

[0007] The closing resistor can suppress the overvoltage generated during the closing process of the circuit breaker. For the circuit breaker used in the converter transformer, it can effectively suppress the excitation surge current of the converter transformer and protect the converter transformer from the impact. Therefore, as a key component of the circuit breaker, the closing resistor needs to ensure the basic functions without reducing the reliability of the circuit breaker and avoid the impact of the circuit breaker due to abnormal closing resistance. Therefore, designing a suitable closing resistor structure is of great significance to the reliability and stability of the circuit breaker. At present, the structure of circuit breakers is becoming more and more compact, and the requirements for the layout of closing resistors are also getting higher and higher. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a closing resistor structure for an 800kV fast circuit breaker, which is used to realize the fast circuit breaker with a closing resistor function and ensure its reliability.

[0009] The present invention is achieved through the following technical scheme, which provides a closing resistor structure for an 800kV fast circuit breaker, including a moving contact and a static contact, wherein the moving contact is slidably connected in a guide cylinder, the guide cylinder is conductively connected to the moving end of the arc extinguishing chamber of the circuit breaker, and the moving contact is connected to the main crank arm of the circuit breaker through a connecting rod assembly; it also includes a small resistor string and a large resistor string located on both sides of the small resistor string, one end of the small resistor string is conductively connected to the static contact, the other end of the small resistor string is conductively connected to one end of the first large resistor string, the other end of the first large resistor string is conductively connected to one end of the second large resistor string, and the other end of the second large resistor string is conductively connected to the static end of the circuit breaker.

[0010] As an optimization, the small resistor string and the large resistor string both include transition connection blocks located at both ends and multiple resistors located between the two transition connection blocks, wherein a resistor spring is installed between one of the transition connection blocks and the resistor, and the number of resistors in the small resistor string is less than the number of resistors in the large resistor string.

[0011] As an optimization, an insulating guide rod is connected between the two transition connection blocks, and the resistor and the resistor spring are both sleeved on the insulating guide rod.

[0012] As an optimization, a U-shaped connecting copper plate is provided between adjacent resistors, two flat plates of the connecting copper plate are respectively fitted with two resistors, and a buffer pad is provided between the two flat plates of the connecting copper plate.

[0013] As an optimization, a pressure cap is installed on the side of the end resistor close to the transition connection block, and the outer ring of the resistor is wrapped with a protective sleeve.

[0014] As an optimization, the end of the static contact away from the moving contact is slidably connected in the insulating support tube, and a static contact conductive block connected to the small resistor string is fixed in the insulating support tube. A static contact spring is installed between the static contact conductive block and the static contact.

[0015] As an optimization, the connecting rod assembly includes a moving contact connecting rod, a resistor-driven crank arm and a resistor-driven connecting rod, one end of the resistor-driven crank arm is hinged to the circuit breaker transmission box, the other end of the resistor-driven crank arm is hinged to one end of the moving contact connecting rod, the other end of the moving contact connecting rod is hinged to the moving contact, one end of the resistor-driven connecting rod is hinged to the resistor-driven crank arm, and the other end of the resistor-driven connecting rod is hinged to the main crank arm of the circuit breaker.

[0016] As an optimization, a moving contact shielding cover is provided on the outer side of the moving contact, and a stationary contact shielding cover is provided on the outer side of the stationary contact.

[0017] As an optimization, the large resistor string is fixed to the static end of the circuit breaker through a supporting insulator.

[0018] As an optimization, the large resistor string and the small resistor string are arranged in parallel.

[0019] The beneficial effects of the present invention are as follows: a closing resistor structure for an 800kV fast circuit breaker of the present invention cleverly combines the driving structure of the moving end of the closing resistor with the original circuit breaker structure without affecting the original structure of the circuit breaker, invents a driving structure so that the partial stroke of the closing resistor is basically consistent with the stroke of the circuit breaker, designs a fixing structure to fix the closing resistor at the lower part of the arc extinguishing chamber, designs a closing resistor insulating support cylinder structure, and maximizes the insulation capacity on the basis of satisfying the insulation support; designs a closing resistor string crimping machine reliability improvement structure to ensure the reliability of the closing resistor, and reduces the overall length through a small resistor string and two large resistor strings to adapt to the overall structural layout of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional schematic diagram of the present invention; Figure 2 A cross-sectional view showing the position of the moving contact of the present invention; Figure 3 It is a schematic diagram of the connecting rod mechanism structure of the present invention; Figure 4 It is a front view of the connecting rod mechanism of the present invention; Figure 5 A cross-sectional view of the stationary contact position of the present invention; Figure 6 A bottom view of the stationary contact position of the present invention; Figure 7 It is a front view of the stationary contact position of the present invention; Figure 8 For the present invention Figure 7 Sectional view of the middle AA plane; Fig. 9 For the present invention Figure 7 Middle BB plane section view; Fig.10It is a cross-sectional schematic diagram of a small resistor string of the present invention; Fig.11 For the present invention Fig.10 Enlarged view of middle C; As shown in the figure: 1. Moving contact, 2. Guide cylinder, 3. Moving contact shielding cover, 4. Moving contact connecting rod, 5. Resistor drive crank arm, 6. Resistor drive connecting rod, 7. Circuit breaker main crank arm, 8. Small resistor string, 81. Transition connection block, 82. Protective cover, 83. Insulating guide rod, 84. Resistor, 85. Resistor spring, 86. Pressure cap, 87. Buffer pad, 88. Connecting copper plate, 9. Large resistor string, 10. Insulating support cylinder, 11. Static contact, 12. Static contact shielding cover, 13. Static contact spring, 14. Static contact conductive block, 15. Transition connection plate, 16. Bending conductive rod. DETAILED DESCRIPTION

[0021] In order to clearly illustrate the technical features of this solution, this solution is described below through a specific implementation method.

[0022] like Figures 1 to 11 As shown, a closing resistor structure for an 800kV fast circuit breaker of the present invention comprises a moving contact 1 and a stationary contact 11, the moving contact 1 and the stationary contact 11 are compactly installed directly below the circuit breaker and fixed at the moving and stationary support positions of the arc extinguishing chamber of the circuit breaker, the moving contact 1 is slidably connected in a guide cylinder 2, the guide cylinder 2 is fixedly arranged, and the guide cylinder 2 is conductively connected to the moving end of the arc extinguishing chamber of the circuit breaker.

[0023] A moving contact shielding cover 3 is provided outside the moving contact 1, and a stationary contact shielding cover 12 is provided outside the stationary contact 11. Ensure that the electric field requirements are met between the closing resistor breaks.

[0024] like Figure 1-4 As shown, the moving contact 1 is connected to the main crank arm 7 of the circuit breaker through a connecting rod assembly, and the connecting rod assembly includes a moving contact connecting rod 4, a resistor-driven crank arm 5 and a resistor-driven connecting rod 6. One end of the resistor-driven crank arm 5 is hinged to the circuit breaker transmission box, the other end of the resistor-driven crank arm 5 is hinged to one end of the moving contact connecting rod 4, the other end of the moving contact connecting rod 4 is hinged to the moving contact 1, one end of the resistor-driven connecting rod 6 is hinged to the resistor-driven crank arm 5, and the other end of the resistor-driven connecting rod 6 is hinged to the circuit breaker main crank arm 7.

[0025] Specifically, a pin hole is added at a specific position of the original circuit breaker main crank arm 7 for connecting the closing resistor driving link 6. The closing resistor driving link 6 is a fork-shaped structure, and one end of the fork is hinged to the pin hole of the main crank arm through a pin. The other end of the closing resistor driving link 6 is hinged to the middle position of the resistor driving crank arm 5. The resistor driving crank arm 5 is composed of two bent plates, the upper end of which is hinged to the circuit breaker transmission box through a pin, and the two bent plates are respectively located on both sides of the closing resistor driving link 6 and on both sides of the moving contact link 4, so as to facilitate the hinge.

[0026] One end of the static contact 11 away from the moving contact 1 is slidably connected in the insulating support tube 10 and is prevented from falling out by a limit block. The other end of the insulating support tube 10 is fixedly connected to a static contact conductive block 14 connected to the small resistor string 8. A static contact spring 13 is installed between the static contact conductive block 14 and the static contact 11. The static contact ensures the function of first closing the resistor break through the static contact spring 13.

[0027] It also includes a small resistor string 8 and a large resistor string 9 located on both sides of the small resistor string 8, wherein the large resistor string 9 is fixed to the static end of the circuit breaker through a supporting insulator. The large resistor string 9 is arranged in parallel with the small resistor string 8. The small resistor string 8 and the two large resistor strings 9 are connected in series in sequence to form a required resistor length.

[0028] The small resistor string 8 is located at the end of the static contact 11 away from the moving contact 1, and is coaxially arranged with the static contact 11. One end of the small resistor string 8 is conductively connected to the static contact 11, the other end of the small resistor string 8 is conductively connected to one end of the first large resistor string 9, the other end of the first large resistor string 9 is conductively connected to one end of the second large resistor string 9, and the other end of the second large resistor string 9 is conductively connected to the static end of the circuit breaker. In this embodiment, Figure 6 The left end of the large resistor string 9 in the upper middle is conductively connected to the left end of the small resistor string 8 through a transition connecting plate 15, such as Figure 6 The right end of the resistor string 9 in the upper middle part is conductively connected to the right end of the resistor string 9 below through the bent conductive rod 16, as shown in FIG. Figure 6 The left end of the large resistor string 9 in the lower middle is conductively connected to the static end of the circuit breaker.

[0029] The small resistor string 8 and the large resistor string 9 have the same structure, but different lengths. The length of the large resistor string 9 is greater than the length of the small resistor string 8.

[0030] like Fig.10As shown, the small resistor string 8 and the large resistor string 9 both include transition connection blocks 81 at both ends and a plurality of resistors 84 between the two transition connection blocks 81, and the number of resistors 84 in the small resistor string 8 is less than the number of resistors 84 in the large resistor string 9. An insulating guide rod 83 is connected between the two transition connection blocks 81, and the resistors 84 are sleeved on the insulating guide rod 83. When the small resistor string 8 and the large resistor string 9 are connected in series, the connection is achieved through the transition connection blocks 81 at the ends.

[0031] A pressure cap 86 is installed on the side of the end resistor 84 close to the transition connection block 81, and a resistor spring 85 is installed between one of the transition connection blocks 81 and the resistor 84. The resistor spring 85 presses on the pressure cap 86, and the resistor spring 85 is used to achieve compression between multiple resistors.

[0032] like Fig.11 As shown, a U-shaped connecting copper plate 88 is provided between adjacent resistors 84, and two flat plates of the connecting copper plate 88 are respectively attached to the two resistors 84, so as to achieve electrical conduction, and a polytetrafluoroethylene buffer pad 87 is provided between the two flat plates of the connecting copper plate 88. When adjacent resistors are squeezed, the buffer pad 87 plays a buffering role, and at the same time, the U-shaped connecting copper plate 88 has a certain buffer deformation while achieving electrical conduction, which improves the impact resistance of the closing resistor on the basis of ensuring reliable connection and conduction of the closing resistor, and prevents the closing resistor from cracking due to excessive squeezing and falling off due to collision.

[0033] The outer ring of the resistor 84 is wrapped with a polytetrafluoroethylene protective sleeve 82 to prevent the resistor wear and debris from falling into the arc extinguishing chamber.

[0034] The method of using the present invention: When the circuit breaker is closed, the main crank arm 7 of the circuit breaker swings, and drives the resistor-driven crank arm 5 to swing forward through the resistor-driven connecting rod 6. The resistor-driven crank arm 5 drives the moving contact 1 to extend forward through the moving contact connecting rod 4, thereby realizing the horizontal linear movement of the moving contact of the closing resistor. After the moving contact 1 contacts and conducts with the static contact 11, the closing resistor is turned on. After conduction, the static contact spring 13 is compressed until the main crank arm 7 of the circuit breaker stops.

[0035] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A closing resistor structure for an 800kV fast circuit breaker, characterized in that: It comprises a moving contact (1) and a stationary contact (11), wherein the moving contact (1) is slidably connected in a guide cylinder (2), the guide cylinder (2) is conductively connected to a moving end of an arc extinguishing chamber of a circuit breaker, and the moving contact (1) is connected to a main crank arm (7) of the circuit breaker via a connecting rod assembly; It also includes a small resistor string (8) and large resistor strings (9) located on both sides of the small resistor string (8), one end of the small resistor string (8) is conductively connected to the static contact (11), the other end of the small resistor string (8) is conductively connected to one end of the first large resistor string (9), the other end of the first large resistor string (9) is conductively connected to one end of the second large resistor string (9), and the other end of the second large resistor string (9) is conductively connected to the static end of the circuit breaker.

2. The closing resistor structure for an 800kV fast circuit breaker according to claim 1, characterized in that: The small resistor string (8) and the large resistor string (9) both comprise transition connection blocks (81) located at both ends and a plurality of resistors (84) located between the two transition connection blocks (81), wherein a resistor spring (85) is installed between one of the transition connection blocks (81) and the resistor (84), and the number of resistors (84) in the small resistor string (8) is less than the number of resistors (84) in the large resistor string (9).

3. The closing resistor structure for an 800kV fast circuit breaker according to claim 2, characterized in that: An insulating guide rod (83) is connected between the two transition connection blocks (81), and the resistor (84) and the resistor spring (85) are both sleeved on the insulating guide rod (83).

4. The closing resistor structure for an 800kV fast circuit breaker according to claim 2, characterized in that: A U-shaped connecting copper plate (88) is provided between adjacent resistors (84), two flat plates of the connecting copper plate (88) are respectively fitted with two resistors (84), and a buffer pad (87) is provided between the two flat plates of the connecting copper plate (88).

5. The closing resistor structure for an 800kV fast circuit breaker according to claim 2, characterized in that: A pressure cap (86) is installed on one side of the resistor (84) at the end close to the transition connection block (81), and the outer ring of the resistor (84) is wrapped with a protective sleeve (82).

6. The closing resistor structure for an 800kV fast circuit breaker according to claim 1, characterized in that: One end of the stationary contact (11) away from the moving contact (1) is slidably connected in the insulating support tube (10), a stationary contact conductive block (14) connected to the small resistor string (8) is fixed in the insulating support tube (10), and a stationary contact spring (13) is installed between the stationary contact conductive block (14) and the stationary contact (11).

7. The closing resistor structure for an 800kV fast circuit breaker according to claim 1, characterized in that: The connecting rod assembly comprises a movable contact connecting rod (4), a resistor-driven crank arm (5) and a resistor-driven connecting rod (6); one end of the resistor-driven crank arm (5) is hinged to a circuit breaker transmission box; the other end of the resistor-driven crank arm (5) is hinged to one end of the movable contact connecting rod (4); the other end of the movable contact connecting rod (4) is hinged to the movable contact (1); one end of the resistor-driven connecting rod (6) is hinged to the resistor-driven crank arm (5); and the other end of the resistor-driven connecting rod (6) is hinged to a circuit breaker main crank arm (7).

8. The closing resistor structure for an 800kV fast circuit breaker according to claim 1, characterized in that: A moving contact shielding cover (3) is provided on the outer side of the moving contact (1), and a stationary contact shielding cover (12) is provided on the outer side of the stationary contact (11).

9. The closing resistor structure for an 800kV fast circuit breaker according to claim 1, characterized in that: The large resistor string (9) is fixed to the static end of the circuit breaker via a supporting insulator.

10. The closing resistor structure for an 800 kV fast circuit breaker according to claim 1, characterized in that: The large resistor string (9) and the small resistor string (8) are arranged in parallel.

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