Black-start auxiliary excitation circuit and wire connecting device

Abstract

The invention relates to the technical field of black-start auxiliary excitation, in particular to a black-start auxiliary excitation circuit and a wire connecting device. The system comprises an excitation silicon controlled rectifier bridge, an alternating current magnetic field circuit breaker and a direct current magnetic field circuit breaker which are electrically connected with the excitation silicon controlled rectifier bridge, an excitation transformer electrically connected with the alternating current magnetic field circuit breaker, and a generator and an alternating current branch which are electrically connected with the excitation transformer, the device comprises an AC power switch electrically connected with the excitation silicon controlled rectifier bridge, an excitation transformer electrically connected with the AC power switch, a first diode rectifier bridge electrically connected with the excitation transformer, and an auxiliary excitation control switch electrically connected with the first diode rectifier bridge. According to the black-start auxiliary excitation circuit, the problem that a conventional direct-current power supply cannot be adopted for auxiliary excitation in the excitation black-start process of a large generator set is solved, and the installation and maintenance efficiency of the black-start auxiliary excitation circuit is improved.

Description

Technical Field

[0001] This invention relates to the field of black-start auxiliary excitation technology, and in particular to a black-start auxiliary excitation circuit and wire connection device. Background Technology

[0002] "Black start" refers to the ability of a power plant to start generating electricity using only the electrical energy stored in the plant's DC system batteries when all AC power supply to the plant is lost, thus providing power to the grid in a timely manner and ensuring grid safety. The black start capability of the unit is not only a necessary measure for the power plant to ensure safe production and self-rescue in the event of a complete power outage, but also a requirement for the development of the power grid.

[0003] The excitation power of the self-excited generator is taken from the excitation transformer connected in parallel at the generator outlet. After rectification by the static thyristor rectifier bridge, it is input to the generator rotor winding through slip rings and brushes to provide excitation for the generator. Since the residual voltage is very low when the generator is initially started, the thyristor rectifier bridge cannot work normally. Measures must be taken to first give the generator initial excitation so that the generator can establish a certain voltage and start the thyristor rectifier bridge to work. This process is called auxiliary excitation.

[0004] The auxiliary excitation power supply can be a DC power supply from the plant or a rectified AC power supply from the plant. To ensure reliable excitation, the auxiliary excitation current should be designed according to 5% of the no-load rated excitation current. According to the standard requirements, the excitation system of units with "black start" requirements should adopt the DC power supply auxiliary excitation method.

[0005] The excitation systems of small and medium-sized self-excited generator sets use conventional DC power supply for auxiliary excitation, which can meet the "black start" requirements of the excitation system. By switching on the DC power supply switch and the auxiliary excitation control switch, the initial excitation current can be provided to the excitation system. The auxiliary excitation current of the excitation system of small and medium-sized self-excited generator sets does not exceed 40A, which is within the range that the plant DC power supply system can withstand. However, the no-load rated excitation current of large self-excited generator sets is about 2000A. If conventional DC power supply is used for auxiliary excitation, the DC power supply system needs to provide an initial excitation current of about 100A. Such a large impact exceeds the range that the DC power supply system of the unit can withstand. Therefore, at present, the auxiliary excitation of large units only uses plant AC power supply. When the plant AC power supply is completely lost, it is impossible to provide auxiliary excitation power. The diesel generator must be used to restore the plant AC power supply before the excitation system can be excited. This process takes a long time and is not conducive to rapid recovery from accidents.

[0006] Meanwhile, the connection of wires in the "black start" auxiliary excitation circuit is generally achieved by tightening the bolts through the copper ring to ensure the stability of the connection. However, the bolt tightening method is cumbersome to install and remove, resulting in a significant waste of time during the installation and maintenance of the circuit. To solve these problems, we propose a black start auxiliary excitation circuit and wire connection device. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] In view of the problem that conventional DC power supply cannot be used to assist excitation during the black start of large generator sets in the above-mentioned or existing technologies, this invention is proposed.

[0009] Therefore, the purpose of this invention is to provide a black-start auxiliary excitation circuit.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a black-start auxiliary excitation circuit, comprising a starting branch, which includes an excitation thyristor rectifier bridge, an AC magnetic field circuit breaker and a DC magnetic field circuit breaker electrically connected to the excitation thyristor rectifier bridge, an excitation transformer electrically connected to the AC magnetic field circuit breaker, and a generator electrically connected to the excitation transformer; an AC branch, which includes an AC power switch electrically connected to the excitation thyristor rectifier bridge, an excitation transformer electrically connected to the AC power switch, a first diode rectifier bridge electrically connected to the excitation transformer, and an auxiliary excitation control switch electrically connected to the first diode rectifier bridge, the auxiliary excitation control switch being electrically connected to the excitation thyristor rectifier bridge; and a DC branch, which includes a current-limiting resistor electrically connected to the auxiliary excitation control switch, a second diode rectifier bridge electrically connected to the current-limiting resistor, and a DC power switch electrically connected to the second diode rectifier bridge, the DC power switch being electrically connected to a plant DC power supply.

[0011] The beneficial effects of the black-start auxiliary excitation circuit of the present invention are as follows: The present invention limits the initial excitation current provided by the DC power supply system to the range that the DC power supply system can withstand through the DC branch, and the AC branch uses a boost rectifier device to realize self-starting by utilizing the positive feedback characteristics of the self-excited system. The auxiliary excitation process is divided into two stages: DC auxiliary start and AC self-start. It can effectively limit the impact of the initial excitation process on the DC power supply system of the power station, thereby solving the problem of auxiliary excitation during the black start process of the excitation system of large self-excited generator sets.

[0012] In practical use, there is a problem that the circuit connections are not easy to disassemble and repair.

[0013] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a wire connection device for connecting wires in a black start auxiliary excitation circuit, including a connection mechanism, which includes a plug-in component and a locking component disposed on the plug-in component, and a pressing mechanism, which includes a pressing component disposed on the plug-in component and an unlocking component opened on the pressing component.

[0014] In a preferred embodiment of the wire connection device of the present invention, the plug-in assembly includes a plug member and a socket member that matches the plug member. The plug member includes a base plate and a plug post disposed on the base plate. The socket member includes a socket block that matches the plug post and a plug groove formed on the socket block.

[0015] As a preferred embodiment of the wire connection device of the present invention, the locking component includes a receiving cavity formed in the inner wall of the plug groove, a snap-fit ​​spring and a snap-fit ​​block disposed in the receiving cavity, and a snap-fit ​​groove formed in the plug post. The snap-fit ​​block has a pressing slope and matches the snap-fit ​​groove.

[0016] In a preferred embodiment of the wire connection device of the present invention, the extrusion assembly includes an extrusion member sleeved on the sleeve block, an extrusion spring disposed on the extrusion member, and a limiting member disposed on the extrusion member. The extrusion member includes a collar sleeved on the sleeve block, a pressure plate disposed at the bottom end of the collar, and a through hole opened on the pressure plate.

[0017] In a preferred embodiment of the wire connection device of the present invention, one end of the compression spring is fixedly connected to the bottom end of the sleeve block, the other end of the compression spring is fixedly connected to the pressure plate, and the inner diameter of the compression spring is the same as the diameter of the insertion groove and the through hole.

[0018] In a preferred embodiment of the wire connection device of the present invention, the limiting member includes a limiting slider disposed on the sleeve block and a limiting groove formed on the inner wall of the collar.

[0019] As a preferred embodiment of the wire connection device of the present invention, the plug-in assembly further includes a vertical rod disposed on the base plate, a guide member disposed on the collar, and a clearance member disposed on the collar. The vertical rod includes a vertical rod disposed on the base plate and a guide block disposed on the vertical rod. The guide member includes a guide groove and a positioning groove disposed on the collar. The guide groove has a first guide surface and a second guide surface.

[0020] As a preferred embodiment of the wire connection device of the present invention, the unlocking component includes an unlocking groove formed on the collar and an unlocking member disposed in the receiving cavity. The unlocking member includes a movable block movably installed in the receiving cavity, a guide rod disposed on the movable block, an unlocking spring sleeved on the guide rod, and a circular hole formed at one end of the receiving cavity. A ball groove is formed at one end of the guide rod, and a sliding ball is disposed in the ball groove.

[0021] In a preferred embodiment of the wire connection device of the present invention, the avoidance member includes a first unlocking avoidance groove formed on the outer wall of the collar and a second unlocking avoidance groove formed on the inner wall of the collar. The first unlocking avoidance groove is connected to the positioning groove, and the second unlocking avoidance groove is connected to the limiting slide groove.

[0022] The beneficial effects of the wire connection device of the present invention are as follows: After the plug and socket are plugged in, the copper rings of the two wires can be locked together by the locking block. The copper rings of the two wires are pressed together by the setting of the pressing member and the pressing spring, thereby ensuring the stability of the connection between the two wires. By rotating the collar, the unlocking spring causes the locking block to retract, thereby completing the unlocking. The present invention is simple and convenient to operate, and greatly improves the efficiency of circuit installation and maintenance. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a circuit for black-start auxiliary excitation.

[0025] Figure 2 This is a schematic diagram of the overall structure of the wire connection device.

[0026] Figure 3 This is a schematic diagram of the exploded structure of a wire connection device.

[0027] Figure 4 This is a schematic diagram of the insert component of the wire connection device.

[0028] Figure 5 This is a schematic diagram of the sleeve structure of the wire connection device.

[0029] Figure 6 This is a schematic diagram of the extrusion structure of the wire connection device.

[0030] Figure 7This is an exploded structural diagram of the locking and unlocking components of a wire connection device. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0034] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a black-start auxiliary excitation circuit that can solve the problem of auxiliary excitation during the black start of the excitation system of a large self-excited generator set. It includes a starting branch 300, which includes an excitation thyristor rectifier bridge 301, an AC field circuit breaker 302 and a DC field circuit breaker 303 electrically connected to the excitation thyristor rectifier bridge 301, an excitation transformer 304 electrically connected to the AC field circuit breaker 302, and a generator 305 electrically connected to the excitation transformer 304. The AC branch 400 includes an AC power switch 401 electrically connected to the excitation thyristor rectifier bridge 301, and an AC power supply... The switch 401 is electrically connected to the excitation transformer 402, the first diode rectifier bridge 403 electrically connected to the excitation transformer 402, and the auxiliary excitation control switch 404 electrically connected to the first diode rectifier bridge 403. The auxiliary excitation control switch 404 is electrically connected to the excitation thyristor rectifier bridge 301. The DC branch 500 includes a current-limiting resistor 501 electrically connected to the auxiliary excitation control switch 404, a second diode rectifier bridge 502 electrically connected to the current-limiting resistor 501, and a DC power switch 503 electrically connected to the second diode rectifier bridge 502. The DC power switch 503 is electrically connected to the plant DC power supply.

[0035] In this embodiment, the DC branch 500 is powered by the power plant's DC 220V supply. After passing through the DC power switch 503, it is connected to the input of the second diode rectifier bridge 502. The output of the second diode rectifier bridge 502 is connected to the current-limiting resistor 501. The AC branch 400 is powered by the AC input of the excitation thyristor rectifier bridge 301. After passing through the AC power switch 401, it is connected to the input of the excitation transformer 402. The output of the excitation transformer 402 is connected to the input of the first diode rectifier bridge 403. The output of the first diode rectifier bridge 403 and the output of the current-limiting resistor 501 are connected in parallel to the input of the auxiliary excitation control switch 404. The output of the auxiliary excitation control switch 404 is connected to the DC output of the excitation thyristor rectifier bridge 301, providing excitation power to the generator rotor.

[0036] The current-limiting resistor R1 is designed to limit the initial excitation current I0 provided by the DC power supply system to 1% to 2% of the unit's no-load rated excitation current, and to be within the range that the DC power supply system can withstand.

[0037] The relationship between the initial excitation current I0 and the unit's no-load rated excitation current If0 satisfies equation (1):

[0038] I0 = n·If0 (1)

[0039] Let the rated secondary voltage of the excitation transformer be Vc, the output-to-input voltage ratio of the AC branch diode rectifier bridge D1 be Kd, and the excitation transformer T103 be a step-up transformer. Its secondary-to-primary voltage step-up ratio Kt must satisfy the condition that the output voltage of the AC branch diode rectifier bridge D1 during initial excitation is higher than the DC power supply system voltage Vd.

[0040] Kt·Kd·n·Vc>Vd (2)

[0041] The auxiliary excitation process is divided into two stages: DC auxiliary start-up and AC self-start-up. When the generator meets the excitation conditions, the AC field circuit breaker 302 and the DC field circuit breaker 303 are closed. After receiving the auxiliary excitation command, the AC power switch 401, the DC power switch 503, and the auxiliary excitation control switch 404 are closed in sequence, entering the DC auxiliary start-up stage. The DC power system provides the initial excitation current through the DC branch 500 of the auxiliary excitation device. When the initial excitation current reaches I0, the output voltage of the AC branch 400 is higher than that of the DC branch 500. The AC branch 400 continues to provide the auxiliary excitation current. Due to the positive feedback of the self-excitation system, the excitation current gradually increases, entering the AC self-start-up stage.

[0042] When the auxiliary excitation current reaches 5% of the no-load rated excitation current, the excitation thyristor rectifier bridge 301 is triggered, the AC power switch 401 and the auxiliary excitation control switch 404 are disconnected, and the excitation thyristor rectifier bridge 301 starts to work, completing the auxiliary excitation process.

[0043] It should be noted that the DC branch 500 of the auxiliary excitation device proposed in this embodiment of the invention can use a current-limiting resistor 501 or other current-limiting components, and the AC branch 400 can use a step-up transformer and a diode rectifier bridge or other step-up rectifier devices.

[0044] Example 2, refer to Figures 2 to 7 This is the second embodiment of the present invention. Unlike the previous embodiment, the connecting mechanism 100 includes a plug-in component 101 and a locking component 102 disposed on the plug-in component 101. The pressing mechanism 200 includes a pressing component 201 disposed on the plug-in component 101 and an unlocking component 202 disposed on the pressing component 201.

[0045] In this embodiment, the plug-in assembly 101 is a split type, with the copper rings of the two wires looped in the plug-in assembly 101. Then, the split plug-in assembly 101 is locked together by the locking assembly 102. The pressing assembly 201 is disposed in the middle of the split plug-in assembly 101. After the split plug-in assembly 101 is locked together, the pressing assembly 201 presses the copper rings of the two wires together to achieve electrical contact and complete the electrical connection. The locking assembly 102 can be unlocked by the setting of the unlocking assembly 202, which facilitates the subsequent maintenance and disassembly.

[0046] The plug-in assembly 101 includes a plug member 101a and a socket member 101b that matches the plug member 101a. The plug member 101a includes a base plate 101a-1 and a plug post 101a-2 disposed on the base plate 101a-1. The socket member 101b includes a socket block 101b-1 that matches the plug post 101a-2 and a plug groove 101b-2 formed on the socket block 101b-1.

[0047] In this embodiment, the base plate 101a-1 is circular, the plug post 101a-2 is welded to the center of the top of the base plate 101a-1, and the plug slot 101b-2 is provided at the center of the bottom of the socket block 101b-1. The plug post 101a-2 and the plug slot 101b-2 are matched.

[0048] The locking assembly 102 includes a receiving cavity 102a formed in the inner wall of the insertion groove 101b-2, a snap-fit ​​spring 102b and a snap-fit ​​block 102c disposed in the receiving cavity 102a, and a snap-fit ​​groove 102d formed in the insertion post 101a-2. The snap-fit ​​block 102c is provided with a pressing slope 102e, and the snap-fit ​​block 102c matches the snap-fit ​​groove 102d.

[0049] In this embodiment, three receiving cavities 102a are arranged in a ring array around the inner wall of the insertion slot 101b-2, and each of the three receiving cavities 102a is equipped with a snap-fit ​​spring 102b and a snap-fit ​​block 102c. Three sets of snap-fit ​​slots 102d are arranged in a ring array around the circumferential sidewall of the insertion post 101a-2, and multiple sets are arranged in a longitudinal linear array around the circumferential sidewall of the insertion post 101a-2. The multiple sets of snap-fit ​​slots 102d arranged in a linear array are used for snap-fit ​​connection of copper sheets of different thicknesses. The snap-fit ​​block 102c... 2c is movably installed in the receiving cavity 102a. One end of the locking block 102c is fixedly connected to the locking spring 102b. The other end of the locking block 102c is provided with a pressing slope 102e. The pressing slope 102e is located on the side of the locking block 102c near the bottom plate 101a-1. With the setting of the pressing slope 102e, when the insertion post 101a-2 is inserted into the insertion slot 101b-2, the locking block 102c will be pressed into the receiving cavity 102a, thereby avoiding affecting the insertion of the insertion post 101a-2.

[0050] Furthermore, when the connecting copper strips of the two wires are relatively thin, the plug post 101a-2 is inserted into the plug slot 101b-2 until the locking block 102c matches and engages with the lowermost locking slot 102d of the linear array on the plug post 101a-2. Then, the two copper strip rings are squeezed by the squeezing component 201 to achieve electrical connection. If the connecting copper strips of the two wires are relatively thick, the plug post 101a-2 is inserted into the plug slot 101b-2 until the squeezing component 201 is squeezed to the bottom and can no longer be squeezed. If the position of the locking block 102c matches the locking slot 102d at this time, it is directly matched and locked. If the position of the locking block 102c does not match the locking slot 102d at this time, the plug post 101a-2 is pulled out slightly so that the locking block 102c is inserted into the nearest locking slot 102d.

[0051] It should be noted that the clamping force of the extrusion assembly 201 on the copper sheet ring is within the range of the extrusion assembly 201 being squeezed to the bottom and unable to be squeezed any further and being forced to loosen one snap-fit ​​groove 102d. Within this range, the extrusion assembly 201 is under high pressure, thereby ensuring the stability of the copper sheet clamping.

[0052] The extrusion assembly 201 includes an extrusion member 201a sleeved on the sleeve block 101b-1, an extrusion spring 201b disposed on the extrusion member 201a, and a limiting member 201c disposed on the extrusion member 201a. The extrusion member 201a includes a collar 201a-1 sleeved on the sleeve block 101b-1, a pressure plate 201a-2 disposed at the bottom end of the collar 201a-1, and a through hole 201a-3 opened on the pressure plate 201a-2.

[0053] One end of the compression spring 201b is fixedly connected to the bottom end of the sleeve block 101b-1, and the other end of the compression spring 201b is fixedly connected to the pressure plate 201a-2. The inner diameter of the compression spring 201b is the same as the diameter of the insertion groove 101b-2 and the through hole 201a-3.

[0054] In this embodiment, the collar 201a-1 is movably sleeved on the circumferential sidewall of the sleeve block 101b-1 via the limiting member 201c. The through hole 201a-3 is opened at the center of the pressure plate 201a-2. A compression spring 201b is disposed between the pressure plate 201a-2 and the sleeve block 101b-1, and the inner diameter of the compression spring 201b is the same as the diameter of the insertion groove 101b-2 and the through hole 201a-3, so that the insertion post 101a-2 is inserted into the insertion groove 101b-2. The insertion is smooth. The compression spring 201b here, in addition to being used for elastic compression, also serves as a guide when inserting the plug post 101a-2. If the inner diameter of the compression spring 201b is not the same as the diameter of the plug groove 101b-2 and the through hole 201a-3, the plug post 101a-2 is prone to tilting inside the compression spring 201b after insertion. This will cause the insertion end of the plug post 101a-2 to not be able to enter the plug groove 101b-2 properly, and manual fine adjustment is required to slowly align it.

[0055] The limiting component 201c includes a limiting slider 201c-1 disposed on the sleeve block 101b-1, and a limiting groove 201c-2 formed on the inner wall of the collar 201a-1.

[0056] In this embodiment, three limiting sliders 201c-1 are arranged in a ring array at the lower end of the outer wall of the sleeve block 101b-1, and three limiting grooves 201c-2 are arranged in a ring array at the inner wall of the collar 201a-1. The three limiting sliders 201c-1 are slidably installed in the three limiting grooves 201c-2 respectively, so that when the collar 201a-1 is squeezed, it and the sleeve block 101b-1 only move up and down, preventing the collar 201a-1 from rotating and releasing the locking of the locking block 102c.

[0057] The plug-in assembly 101 also includes a vertical rod 101c disposed on the base plate 101a-1, a guide 101d disposed on the collar 201a-1, and a clearance member 101e disposed on the collar 201a-1. The vertical rod 101c includes a vertical rod 101c-1 disposed on the base plate 101a-1 and a guide block 101c-2 disposed on the vertical rod 101c-1. The guide 101d includes a guide groove 101d-1 and a positioning groove 101d-2 disposed on the collar 201a-1. A first guide surface 101d-3 and a second guide surface 101d-4 are provided on the guide groove 101d-1.

[0058] In this embodiment, the upright 101c-1 is symmetrically arranged about the outer circumference of the base plate 101a-1. A guide block 101c-2 is welded to the end of the upright 101c-1 away from the base plate 101a-1 and facing the central axis of the base plate 101a-1. The guide member 101d is symmetrically opened about the outer circumference of the collar 201a-1. The guide groove 101d-1 is opened at the lower end of the circumferential side wall of the collar 201a-1, and the positioning groove 101d-2 is opened at the upper end of the circumferential side wall of the collar 201a-1. The guide groove 101d-1 and the positioning groove 101d-2 are connected.

[0059] Furthermore, the first guide surface 101d-3 is formed on both sides of the guide groove 101d-1, making the projected shape of the guide groove 101d-1 trapezoidal. The second guide surface 101d-4 is formed at the bottom of the guide groove 101d-1, which facilitates the initial insertion of the insert 101a and the sleeve 101b. The collar 201a-1 can pass through the symmetrical upright 101c-1 better. As the insert 101a and the sleeve 101b continue to be inserted, the first guide surface 101d-3 presses the guide block 101c-2, causing the guide block 101c-2 to enter the positioning groove 101d-2. This allows the locking block 102c on the insert 101a to match and engage with the locking groove 102d, eliminating the hassle of manual rotation and engagement.

[0060] Example 3, referring to Figures 2 to 7 This is the third embodiment of the present invention. Unlike the previous embodiment, the unlocking component 202 includes an unlocking groove 202a opened on the collar 201a-1 and an unlocking member 202b disposed in the receiving cavity 102a. The unlocking member 202b includes a movable block 202b-1 movably installed in the receiving cavity 102a, a guide rod 202b-2 disposed on the movable block 202b-1, an unlocking spring 202b-3 sleeved on the guide rod 202b-2, and a circular hole 202b-4 opened at one end of the receiving cavity 102a. A ball groove 202b-5 is opened at one end of the guide rod 202b-2, and a sliding ball 202b-6 is disposed in the ball groove 202b-5.

[0061] In this embodiment, the unlocking groove 202a is formed on the inner wall of the collar 201a-1, and three sets are formed in a circular array around the inner wall of the collar 201a-1. Each set of unlocking grooves 202a has two grooves, which are symmetrically arranged so that the collar 201a-1 can be unlocked by rotating it left or right. There are three sets of unlocking components 202b, which correspond to the unlocking of the three locking blocks 102c respectively. The movable block 202b-1, the guide rod 202b-2, and the unlocking spring 202b-3 are all set in the receiving cavity 102a. One side of the movable block 202b-1 is welded to one end of the guide rod 202b-2. The unlocking spring 202b-3 is sleeved on the guide rod 202b-2. One end of the movable block 202b-1 is fixedly connected to the other end of the movable block 202b-1. The other end of the unlocking spring 202b-3 is welded to the inner wall of the receiving cavity 102a. Three round holes 202b-4 are arranged in a ring array about the sleeve block 101b-1, which are respectively connected to the three receiving cavities 102a and are matched and inserted with the guide rod 202b-2. A ball groove 202b-5 is provided at the end of the guide rod 202b-2 away from the movable block 202b-1, and a sliding ball 202b-6 is movably installed in the ball groove 202b-5. By setting the sliding ball 202b-6, the collar 201a-1 and the unlocking part 202b become smaller when unlocking, thereby facilitating the rotation and unlocking of the collar 201a-1.

[0062] Furthermore, the side of the movable block 202b-1 away from the unlocking spring 202b-3 is fixedly connected to the snap-fit ​​spring 102b. In the initial state, the guide rod 202b-2 and the sliding ball 202b-6 at one end are squeezed by the inner wall of the collar 201a-1 and are both housed in the receiving cavity 102a. The unlocking spring 202b-3 is in a stretched state. At this time, the position of the snap-fit ​​block 102c is protruding from the inner wall of the insertion groove 101b-2, but the lower end of the extrusion slope 102e on the snap-fit ​​block 102c is still located in the receiving cavity 102a. In the unlocked state, the guide rod 202b-2 and the sliding ball 202b-6 at one end are not squeezed by the inner wall of the collar 201a-1. The unlocking spring 202b-3 retracts and resets, causing the movable block 202b-1 to retract towards the circular hole 202b-4, thereby causing the snap-fit ​​block 102c to disengage from the snap-fit ​​groove 102d and enter the receiving cavity 102a, completing the unlocking.

[0063] It should be noted that after the collar 201a-1 is unlocked by rotation, it is reset by the torque of the compression spring 201b. Therefore, the compression spring 201b in this invention plays a key role, serving three purposes: it is not only used as a compression spring to press the copper sheet ring, but also as a guide sleeve for the insertion post 101a-2, and as a torsion spring for resetting the collar 201a-1.

[0064] The clearance component 101e includes a first unlocking clearance groove 101e-1 formed on the outer wall of the collar 201a-1, and a second unlocking clearance groove 101e-2 formed on the inner wall of the collar 201a-1. The first unlocking clearance groove 101e-1 is connected to the positioning groove 101d-2, and the second unlocking clearance groove 101e-2 is connected to the limiting slide groove 201c-2.

[0065] In this embodiment, the first unlocking clearance groove 101e-1 is horizontally opened, and the first unlocking clearance groove 101e-1 and the positioning groove 101d-2 are cross-connected. The second unlocking clearance groove 101e-2 is horizontally opened, and the limiting slide groove 201c-2 is set in an inverted T-shape.

[0066] It should be noted that the longitudinal width of the first unlocking avoidance slot 101e-1, the second unlocking avoidance slot 101e-2 and the unlocking slot 202a is the same as the body width of the two card blocks 102c.

[0067] The rest of the structure is the same as in Example 2.

[0068] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0069] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0070] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine task in design, manufacturing, and production without requiring extensive experimentation.

[0071] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A black start assist energizing circuit, characterized by: include, The starting branch (300) includes an excitation thyristor rectifier bridge (301), an AC field circuit breaker (302) and a DC field circuit breaker (303) electrically connected to the excitation thyristor rectifier bridge (301), an excitation transformer (304) electrically connected to the AC field circuit breaker (302), and a generator (305) electrically connected to the excitation transformer (304). An AC branch (400) includes an AC power switch (401) electrically connected to the excitation thyristor rectifier bridge (301), an excitation transformer (402) electrically connected to the AC power switch (401), a first diode rectifier bridge (403) electrically connected to the excitation transformer (402), and an auxiliary excitation control switch (404) electrically connected to the first diode rectifier bridge (403). The auxiliary excitation control switch (404) is electrically connected to the excitation thyristor rectifier bridge (301). The DC branch (500) includes a current-limiting resistor (501) electrically connected to the auxiliary excitation control switch (404), a second diode rectifier bridge (502) electrically connected to the current-limiting resistor (501), and a DC power switch (503) electrically connected to the second diode rectifier bridge (502), the DC power switch (503) being electrically connected to the plant DC power supply.

2. A wire connecting device, characterized by: The connection of the wires in the black-start auxiliary excitation circuit according to claim 1 includes, The connecting mechanism (100) includes a plug-in assembly (101) and a locking assembly (102) disposed on the plug-in assembly (101); The compression mechanism (200) includes a compression component (201) disposed on the insertion component (101) and an unlocking component (202) disposed on the compression component (201).

3. The wire connection device as described in claim 2, characterized in that: The plug assembly (101) includes a plug (101a) and a socket (101b) that mates with the plug (101a); The insert member (101a) includes a base plate (101a-1) and an insert post (101a-2) disposed on the base plate (101a-1); The socket (101b) includes a socket block (101b-1) that matches the plug post (101a-2), and a plug groove (101b-2) formed on the socket block (101b-1).

4. The wire connection device as described in claim 3, characterized in that: The locking assembly (102) includes a receiving cavity (102a) formed in the inner wall of the insertion slot (101b-2), a snap-fit ​​spring (102b) and a snap-fit ​​block (102c) disposed in the receiving cavity (102a), and a snap-fit ​​groove (102d) formed in the insertion post (101a-2). The card block (102c) has a pressing slope (102e) and the card block (102c) matches the card slot (102d).

5. The wire connection device as described in claim 4, characterized in that: The extrusion assembly (201) includes an extrusion member (201a) sleeved on the sleeve block (101b-1), an extrusion spring (201b) disposed on the extrusion member (201a), and a limiting member (201c) disposed on the extrusion member (201a); The extrusion member (201a) includes a collar (201a-1) sleeved on the sleeve block (101b-1), a pressure plate (201a-2) disposed at the bottom end of the collar (201a-1), and a through hole (201a-3) opened on the pressure plate (201a-2).

6. The wire connection device as described in claim 5, characterized in that: One end of the compression spring (201b) is fixedly connected to the bottom end of the sleeve block (101b-1), and the other end of the compression spring (201b) is fixedly connected to the pressure plate (201a-2). The inner diameter of the compression spring (201b) is the same as the diameter of the insertion groove (101b-2) and the through hole (201a-3).

7. The wire connection device as described in claim 6, characterized in that: The limiting component (201c) includes a limiting slider (201c-1) disposed on the sleeve block (101b-1) and a limiting groove (201c-2) formed on the inner wall of the collar (201a-1).

8. The wire connection device as described in claim 7, characterized in that: The plug-in assembly (101) also includes a vertical rod (101c) disposed on the base plate (101a-1), a guide (101d) disposed on the collar (201a-1), and a clearance member (101e) disposed on the collar (201a-1); The upright member (101c) includes an upright (101c-1) disposed on the base plate (101a-1) and a guide block (101c-2) disposed on the upright (101c-1); The guide member (101d) includes a guide groove (101d-1) and a positioning groove (101d-2) formed on the collar (201a-1), and a first guide surface (101d-3) and a second guide surface (101d-4) are formed on the guide groove (101d-1).

9. The wire connection device as described in claim 8, characterized in that: The unlocking assembly (202) includes an unlocking groove (202a) formed on the collar (201a-1) and an unlocking member (202b) disposed in the receiving cavity (102a); The unlocking component (202b) includes a movable block (202b-1) movably installed in the receiving cavity (102a), a guide rod (202b-2) disposed on the movable block (202b-1), an unlocking spring (202b-3) sleeved on the guide rod (202b-2), and a circular hole (202b-4) opened at one end of the receiving cavity (102a); One end of the guide rod (202b-2) is provided with a ball groove (202b-5), and a sliding ball (202b-6) is provided in the ball groove (202b-5).

10. The wire connection device as described in claim 9, characterized in that: The avoidance component (101e) includes a first unlocking avoidance groove (101e-1) formed on the outer wall of the collar (201a-1) and a second unlocking avoidance groove (101e-2) formed on the inner wall of the collar (201a-1); The first unlocking clearance groove (101e-1) is connected to the positioning groove (101d-2), and the second unlocking clearance groove (101e-2) is connected to the limiting slide groove (201c-2).

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