A kind of flexible direct current transmission system power grid fault ride-through control device and method

Abstract

The present invention discloses a control device and method for grid fault riding in a flexible direct current transmission system, and relates to the technical field of conductive component connection devices. A control device for grid fault riding in a flexible direct current transmission system, comprising a first wire harness and a second wire harness, each of which has one end exposed; the present invention can effectively separate a pair of first wire cores and a pair of second wire cores by setting a support block and a separation box, and the through holes symmetrically opened on the support block are spaced far apart, so compared with the conical wire splitter in the prior art, a pair of first wire cores and a pair of second wire cores can be well separated, effectively avoiding a pair of first wire cores and a pair of second wire cores being too close to each other, causing contact and short circuit, or causing a pair of first wire cores and a pair of second wire cores to slip when an external force pulls the pair of first wire cores and a pair of second wire cores, causing contact and short circuit.

Description

Technical Field

[0001] The present invention belongs to the technical field of conductive component connection devices, and in particular, relates to a grid fault ride-through control device for a flexible direct current power transmission system. Background Art

[0002] Flexible DC transmission system, referred to as FDTS; grid fault ride-through control means that in a flexible DC transmission system, when a grid fault occurs, the controller quickly responds to and adjusts the grid to ensure the stability and safety of the system; this control method can help the system quickly resume normal operation, reduce the impact of faults on the system, and improve the reliability and stability of the grid;

[0003] However, the common FDTS fault ride-through control equipment is large in size, with complex internal wiring, and is difficult to install and troubleshoot. The existing FDTS fault ride-through control equipment directly installs each functional module inside the cabinet and interconnects them through wires, but the internal wiring is complicated and cannot be prefabricated. It needs to be wired on site, resulting in low work efficiency, easy errors during wiring, and difficult to troubleshoot after errors. Moreover, when the equipment enters the operation and maintenance stage, once a fault occurs, it is difficult to troubleshoot, and the wires are not easy to disassemble and replace.

[0004] In the prior art, the authorization announcement number is CN112531883B, the authorization announcement date is 2023.05.12, and the name is a new type of modular FTU; this new type of modular FTU, when the equipment needs to be replaced or maintained, only the wiring harness connector needs to be unplugged to replace the entire device, realizing modular operation and maintenance with high efficiency. When the FTU product needs to be assembled, only the wiring harness ends on the two integrated modules to be connected need to be plugged and fixed one by one through the wiring harness connector, without the need for cumbersome wiring operations, simple operation and high reliability;

[0005] Although the above technical solution can separate the exposed first core, second core, third core and fourth core through the branching head to avoid contact and short circuit, the branching head has a conical cross-section, which causes the cores on both sides of the tip of the branching head to be adjacent, which can easily cause contact short circuit. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a flexible direct current transmission system power grid fault ride-through control device that can overcome the above problems or at least partially solve the above problems.

[0007] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: a flexible direct current transmission system power grid fault ride-through control device, including a controller module, used to monitor the power grid state, calculate the control strategy and issue corresponding instructions; a fault ride-through control module, used to identify power grid faults and take corresponding measures; a monitoring module, used to monitor the voltage, current and frequency of the power grid in real time; a communication module, used for data transmission and communication between the controllers or between the controller and the monitoring device, and also includes: the lines connected between the controller module, the fault ride-through control module, the monitoring module and the communication module are all detachable two-stage, and the two-stage lines respectively include a first wiring harness and a second wiring harness with one end exposed, the first A pair of first electric wires with exposed first cores are formed at one end of the wiring harness, and a pair of second electric wires with exposed second cores are formed at one end of the second wiring harness, and the first electric wires and the second electric wires are connected by a first connecting sleeve and a second connecting sleeve; a support block is respectively arranged in the first connecting sleeve and the second connecting sleeve, and a pair of the first cores respectively pass through two through holes opened in the support block and facing away from each other; a separation box is respectively arranged in one end of the first connecting sleeve and the second connecting sleeve away from each other, and the first electric wire and the second electric wire with insulating sheaths respectively pass through the separation box; a connecting block is located between the first connecting sleeve and the second connecting sleeve, and two terminal posts are arranged on the connecting block to electrically connect a pair of the first cores and the second cores.

[0008] Preferably, slots are symmetrically provided on the connection block, one side of the terminal slot is plugged into the slot, and a through slot is provided in the connection block.

[0009] Furthermore, a guide rod is fixedly connected to one side of the support block, and a push block is slidably connected to the guide rod. The push block and the support block are connected by a spring. The outer surface of the push block is respectively in contact with the corresponding first wire core and second wire core. In the process of approaching the two ends of the first connecting sleeve and the second connecting sleeve, the connecting block pushes the push blocks in the first connecting sleeve and the second connecting sleeve respectively, so that the push blocks approach the corresponding first wire harness and second wire harness respectively.

[0010] Preferably, the spring is made of plastic material.

[0011] Furthermore, an isolation filling sleeve is fixedly connected between the push-pull block and the support block, and the isolation filling sleeve is arranged on the spring rod. A through-shaped limiting groove is symmetrically opened on the outer circumference of the push-pull block, and an annular release groove is opened on the circumference of the push-pull block. The depth of the release groove is greater than the depth of the limiting groove.

[0012] Furthermore, an air channel is opened in the guide rod, one end of the air channel penetrates through the outer wall of the guide rod, the push block corresponds to the part where the air channel penetrates through the outer wall of the guide rod, and an inflation tube is fixedly connected to the other side of the support block, so as to automatically fill the first connecting sleeve and the second connecting sleeve with protective gas when the first connecting sleeve and the second connecting sleeve are connected.

[0013] Preferably, a threaded sleeve is sleeved on the outer circumference of the first connecting sleeve, an inner diameter of one end of the threaded sleeve is provided with an internal thread, an outer wall of one end of the second connecting sleeve is provided with an external thread, and the first connecting sleeve and the second connecting sleeve are locked and connected by the threaded sleeve.

[0014] Furthermore, two first rubber sleeves and one second rubber sleeve are fixedly connected to the separation box, respectively. The first rubber sleeves correspond to the corresponding first electric wires and second electric wires, respectively, and the second rubber sleeve corresponds to the inflation tube on the expansion block.

[0015] Furthermore, a limiting slide groove is provided on the inner wall of the separation box, a sliding plate is slidably connected in the limiting slide groove, the outer walls of the first rubber sleeve and the second rubber sleeve are both conical, the sliding plate slides on the first rubber sleeve and the second rubber sleeve, and when the first connecting sleeve and the second connecting sleeve are filled with protective gas, the protective gas pushes the sliding plate toward the bottom of the separation box to shrink and squeeze the first rubber sleeve and the second rubber sleeve.

[0016] A method for using a grid fault ride-through control device of a flexible direct current transmission system mainly comprises the following steps:

[0017] S1. Put the locking ring on the first wiring harness and the second wiring harness in sequence, then put the separation box on the pair of first wires on the first wiring harness and the pair of second wires on the second wiring harness in sequence, and then put the pair of first wires and the pair of second wires on the second wiring harness into the corresponding first connecting sleeve and the second connecting sleeve respectively;

[0018] S2, inserting the first wire core and the second wire core into the two ends of the terminal, respectively, and then inserting the two ends of the connecting block into the guide rods in the first connecting sleeve and the second connecting sleeve respectively;

[0019] S3. Bring the first connecting sleeve and the second connecting sleeve close to each other and lock them to achieve the connection between the first wiring harness and the second wiring harness.

[0020] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0021] 1. The flexible DC power transmission system grid fault ride-through control device can effectively separate a pair of first cores and a pair of second cores through the provided expansion block, and the through holes symmetrically provided on the expansion block are spaced far apart. Therefore, compared with the conical branching head in the prior art, the pair of first cores and the pair of second cores can be well separated, effectively avoiding the pair of first cores and the pair of second cores being too close to each other, thereby causing contact and short circuit, or when the pair of first cores and the pair of second cores are pulled by external force, causing the pair of first cores and the pair of second cores to slip, thereby causing contact and short circuit;

[0022] 2. The grid fault ride-through control device of the flexible direct current transmission system is provided with a separation box, and the first wire with an insulating sheath and the second wire with an insulating sheath are respectively passed through the openings provided on the separation box, and then the first wire core, the second wire core and the part between the insulating sheaths on the first wire and the second wire are again spread open, so that a pair of first wire cores and a pair of second wire cores are separated from each other. Therefore, the device can not only avoid the first wire core and the second wire core without insulating sheath being adjacent to each other, but also facilitate rapid installation when each module is connected;

[0023] 3. The grid fault ride-through control device of the flexible direct current transmission system can further open a pair of first cores and second cores distributed in a V shape when the push-pushing block moves close to the separation box, so that the first cores and second cores are further in close contact with the inner walls of the first connecting sleeve and the second connecting sleeve, thereby increasing the separation distance between the first cores and the second cores, further preventing the first cores and the second cores from accidentally contacting each other, and at the same time, when the connecting block enters the first connecting sleeve and the second connecting sleeve, it can further increase the pressing force on the first cores and the second cores, further preventing the first wire harness and the second wire harness from being separated due to external force pulling;

[0024] 4. The grid fault ride-through control device of the flexible direct current power transmission system can open the air passage when the first connecting sleeve and the second connecting sleeve are close to each other and locked, and the connecting block pushes the separation push block to further separate the pair of first wire cores and the pair of second wire cores, so that the gas charging pipe connected to the external gas cylinder through the pipeline automatically fills the protective gas into the connected first connecting sleeve and the second connecting sleeve, effectively protecting the first wire core, the second wire core and the terminal in the first connecting sleeve and the second connecting sleeve, and improving the oxidation resistance;

[0025] 5. The grid fault ride-through control device of the flexible DC power transmission system can not only open the first core, the second core and the part between the insulating sheaths on the first wire and the second wire again through the separation box, so that a pair of first cores and a pair of second cores are separated from each other, but also can further reduce the gap between the first rubber sleeve, the second rubber sleeve and the corresponding first wire, the second wire and the inflation tube by using the gas pressure of the filled protective gas when filling the protective gas, further avoid gas leakage, and improve the effect of filling the protective gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the attached picture:

[0027] Figure 1 A system framework diagram of a grid fault ride-through control device for a flexible direct current transmission system proposed by the present invention;

[0028] Figure 2 A structural schematic diagram of a threaded sleeve of a grid fault ride-through control device for a flexible DC power transmission system proposed by the present invention;

[0029] Figure 3 A schematic structural diagram of a first connection sleeve and a second connection sleeve of a grid fault ride-through control device for a flexible direct current transmission system proposed by the present invention;

[0030] Figure 4 A schematic diagram of the structure of a connection block of a grid fault ride-through control device for a flexible direct current transmission system proposed by the present invention;

[0031] Figure 5 A grid fault ride-through control device for a flexible DC transmission system proposed by the present invention Figure 4 The structural diagram at A in the middle;

[0032] Figure 6 A schematic diagram of the structure of a terminal block of a grid fault ride-through control device for a flexible direct current transmission system proposed by the present invention;

[0033] Figure 7 A schematic structural diagram of a spring and an insulating filling sleeve of a grid fault ride-through control device of a flexible direct current transmission system proposed by the present invention;

[0034] Figure 8 A schematic diagram of the structure of a release slot and a limit slot of a grid fault ride-through control device of a flexible direct current transmission system proposed by the present invention;

[0035] Fig. 9 A schematic diagram of the structure of a support block and a through hole of a grid fault ride-through control device of a flexible direct current transmission system proposed by the present invention;

[0036] Fig.10A schematic diagram of the structure of a through slot of a grid fault ride-through control device of a flexible DC transmission system proposed by the present invention;

[0037] Fig.11 This is a schematic structural diagram of a first rubber sleeve and a second rubber sleeve of a grid fault ride-through control device for a flexible direct current transmission system proposed by the present invention.

[0038] In the figure: 1. first wiring harness; 111. first electric wire; 112. first wire core; 10. threaded sleeve; 11. first connecting sleeve; 12. second connecting sleeve; 13. locking ring; 14. expansion block; 140. through hole; 141. guide rod; 142. push block; 143. limiting groove; 144. release groove; 145. airway; 146. insulating filling sleeve; 147. spring; 148. connecting hole; 149. inflation tube; 15. separation box; 151. first rubber sleeve; 152. second rubber sleeve; 153. sliding plate; 154. limiting sliding groove; 2. connecting block; 21. through groove; 22. slot; 23. terminal; 3. second wiring harness; 31. second electric wire; 32. second wire core. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0040] Example 1: Reference Figure 1-Figure 11 A grid fault ride-through control device for a flexible direct current transmission system includes a controller module for monitoring the grid state, calculating control strategies and issuing corresponding instructions to control the operation of the grid; a fault ride-through control module for identifying grid faults and taking corresponding measures, such as disconnecting the faulty part and adjusting the power; a monitoring module for real-time monitoring of the voltage, current and frequency of the grid; and a communication module for data transmission and communication between controllers or between the controller and the monitoring device. Therefore, through the coordinated work of the controller module, the fault ride-through control module, the monitoring module and the communication module, the grid fault ride-through control can achieve rapid response and adjustment to the grid, ensuring the stability and safety of the system.

[0041] The device also includes: the circuits connected between the controller module, the fault-through control module, the monitoring module, and the communication module are all detachable two-stage, and the two-stage circuits respectively include a first wiring harness 1 and a second wiring harness 3 with one end exposed, a pair of first wires 111 with a first wire core 112 exposed at one end of the first wiring harness 1, and a pair of second wires 31 with a second wire core 32 exposed at one end of the second wiring harness 3, the first wire 111 and the second wire 31 are connected through a first connecting sleeve 11 and a second connecting sleeve 12; the support block 14 is respectively provided with In the first connection sleeve 11 and the second connection sleeve 12, a pair of first wire cores 112 respectively pass through two through holes 140 opened on the expansion block 14 and facing away from each other; the separation box 15 is respectively arranged at the ends of the first connection sleeve 11 and the second connection sleeve 12 that are away from each other, and the first wire 111 and the second wire 31 with insulating sheaths respectively pass through the separation box 15; the connection block 2 is located between the first connection sleeve 11 and the second connection sleeve 12, and two terminal posts 23 are arranged on the connection block 2 to electrically connect the pair of first wire cores 112 and the second wire core 32;

[0042] Since the opening block 14 and the separation box 15 are respectively connected to the two ends of the first connection sleeve 11 and the second connection sleeve 12, the separation box 15 is firstly sleeved on the pair of first wires 111 on the first wiring harness 1 and the pair of second wires 31 on the second wiring harness 3, and then the pair of first wires 111 and the second wires 31 are respectively passed through the first connection sleeve 11 and the second connection sleeve 12, and then the opening block 14 is respectively passed through the first wire core 112 on the first wire 111 and the second wire core 32 of the second wire 31, so that the separation box 15 and the opening block 14 on the first connection sleeve 11 and the second connection sleeve 12 are respectively located at the two ends of the first connection sleeve 11 and the second connection sleeve 12;

[0043] The separation box 15 is inserted into one end of the first connection sleeve 11 and the second connection sleeve 12 in a sliding manner. The device is put on the pair of first wires 111 on the first wiring harness 1 and the pair of second wires 31 on the second wiring harness 3 before the separation box 15 is put on. In the subsequent operation, the locking ring 13 is threadedly connected to the inner wall of one end of the corresponding first connection sleeve 11 and the second connection sleeve 12, thereby fixing the separation box 15; in addition, in order to facilitate the rotation of the locking ring 13, tool holes are symmetrically opened on the outer circumference of the locking ring 13, and by inserting a tool into the tool hole, the locking ring 13 can be conveniently driven to tighten;

[0044] The device can effectively separate a pair of first wire cores 112 and a pair of second wire cores 32 by means of the opening block 14, and the through holes 140 symmetrically opened on the opening block 14 are spaced far apart. Therefore, compared with the tapered wire splitter in the prior art, the device can well separate a pair of first wire cores 112 and a pair of second wire cores 32, and effectively avoid the pair of first wire cores 112 and a pair of second wire cores 32 being too close to each other, thereby causing a short circuit to occur when the pair of first wire cores 112 and a pair of second wire cores 32 are in contact, or when an external force pulls the pair of first wire cores 112 and a pair of second wire cores 32, causing the pair of first wire cores 112 and a pair of second wire cores 32 to slip off, thereby causing a short circuit to occur when the pair of first wire cores 112 and a pair of second wire cores 32 are in contact;

[0045] At the same time, the device also provides a separation box 15, and allows the first wire 111 with an insulating sheath and the second wire 31 with an insulating sheath to pass through the openings provided on the separation box 15, respectively, and then the first wire core 112, the second wire core 32 and the portion between the insulating sheaths on the first wire 111, the second wire 31 are stretched again, so that the pair of first wire cores 112 and the pair of second wire cores 32 are separated from each other;

[0046] Insert one end of a pair of first wire cores 112 and one end of a pair of second wire cores 32 into one end of a symmetrical terminal 23 on the connection block 2, respectively. The terminal 23 is made of a metal conductive material, preferably copper, to electrically connect the pair of first wire cores 112 and the pair of second wire cores 32;

[0047] The adjacent ends of the first connecting sleeve 11 and the second connecting sleeve 12 are brought close together, and the two ends of the connecting block 2 will enter the first connecting sleeve 11 and the second connecting sleeve 12 respectively. During the process of the connecting block 2 entering, the two ends of the connecting block 2 will further squeeze the pair of first wire cores 112 and the pair of second wire cores 32 onto the inner walls of the first connecting sleeve 11 and the second connecting sleeve 12;

[0048] Then, after the adjacent ends of the first connecting sleeve 11 and the second connecting sleeve 12 are attached to each other, the first connecting sleeve 11 and the second connecting sleeve 12 are locked, thereby completing the connection of the lines between the controller module, the fault ride-through control module, the monitoring module, and the communication module;

[0049] When the device needs to be replaced or maintained, it is only necessary to separate the first connecting sleeve 11 and the second connecting sleeve 12 for replacement, thereby realizing modular operation and maintenance and effectively improving work efficiency.

[0050] Reference Figure 6 , Fig.10 , a slot 22 is symmetrically provided on the connection block 2, one side of the connection post 23 slot 22 is plugged into the slot 22, and a through slot 21 is provided in the connection block 2;

[0051] The opening of the slot 22 facilitates the connection of the terminal 23 to the connection block 2. The cross-sectional shape of the slot 22 is the same as that of the guide rod 141, so as to prevent the connection block 2 from rotating.

[0052] It should be understood that the connection block 2 is made of non-metallic material to prevent electrical conduction, and is preferably made of plastic or resin.

[0053] Reference Figure 4 , Figure 6 , Figure 7 , Figure 8 A guide rod 141 is fixedly connected to one side of the support block 14, and a push block 142 is slidably connected to the guide rod 141. The push block 142 is connected to the support block 14 through a spring 147. The outer surfaces of the push block 142 are respectively in contact with the corresponding first wire core 112 and the second wire core 32. During the process of the first connecting sleeve 11 and the second connecting sleeve 12 approaching each other, the connecting block 2 pushes the push block 142 in the first connecting sleeve 11 and the second connecting sleeve 12 respectively, so that the push block 142 approaches the corresponding first wire harness 1 and the second wire harness 3 respectively;

[0054] The device is provided with a guide rod 141, and the cross section of the guide rod 141 is rectangular, and a push block 142 is slidably provided on the guide rod 141. When the adjacent ends of the first connecting sleeve 11 and the second connecting sleeve 12 are close to each other, the connecting block 2 will abut against the corresponding push block 142 in the first connecting sleeve 11 and the second connecting sleeve 12 when entering the first connecting sleeve 11 and the second connecting sleeve 12, and push the push block 142 to move into the first connecting sleeve 11 and the second connecting sleeve 12. When the push block 142 moves close to the separation box 15, the push block 142 can further be distributed in a V-shape. The pair of first wire cores 112 and second wire cores 32 are stretched apart, so that the first wire cores 112 and second wire cores 32 are further closely attached to the inner walls of the first connecting sleeve 11 and the second connecting sleeve 12, thereby increasing the separation distance between the first wire cores 112 and the second wire cores 32, further preventing the first wire cores 112 and the second wire cores 32 from accidentally contacting each other. At the same time, when the connecting block 2 enters the first connecting sleeve 11 and the second connecting sleeve 12, the pressing force on the first wire cores 112 and the second wire cores 32 can be further increased, further preventing the first wire harness 1 and the second wire harness 3 from being separated when pulled by external force;

[0055] The spring 147 is made of plastic material;

[0056] When the push block 142 is pushed, the spring 147 is squeezed, so that the spring 147 contracts and stacks; and the stacking part of the spring 147 is located at the opening block 14, which can effectively further open the position where the first wire core 112 and the second wire core 32 are connected to the opening block 14, and form an isolation between the pair of first wire cores 112 and the pair of second wire cores 32, further avoiding the situation where the pair of first wire cores 112 and the pair of second wire cores 32 come into contact with each other;

[0057] The spring 147 provided at the same time can push the push block 142 toward the end adjacent to the first connecting sleeve 11 and the second connecting sleeve 12 when the first connecting sleeve 11 and the second connecting sleeve 12 are separated, so as to facilitate disassembly.

[0058] Reference Figure 7 An isolating filling sleeve 146 is fixedly connected between the push block 142 and the opening block 14, and the isolating filling sleeve 146 is sleeved on the spring 147. A through-shaped limiting groove 143 is symmetrically provided on the outer circumference of the push block 142, and an annular release groove 144 is provided on the circumference of the push block 142. The depth of the release groove 144 is greater than the depth of the limiting groove 143. The isolating filling sleeve 146 can sleeve the spring 147, and when the push block 142 moves to squeeze the spring 147, the isolating filling sleeve 146 can be compressed and stacked, thereby further isolating between the pair of first cores 112 and the pair of second cores 32, and further avoiding the situation where the pair of first cores 112 and the pair of second cores 32 come into contact with each other;

[0059] At the same time, the limiting groove 143 on the push block 142 can limit the first wire core 112 and the second wire core 32 to prevent the first wire core 112 and the second wire core 32 from changing their positions during installation and causing them to be adjacent to each other;

[0060] At the same time, the release groove 144 on the push block 142 can release the stress of the first wire core 112 and the second wire core 32 during the process of the push block 142 moving and stretching the first wire core 112 and the second wire core 32. The release groove 144 is recessed inwardly to release the stress of the first wire core 112 and the second wire core 32 during the process of being stretched, so that the first wire core 112 and the second wire core 32 can be further tightly attached to the inner walls of the first connecting sleeve 11 and the second connecting sleeve 12, and the first wire core 112 and the second wire core 32 are effectively clamped in the first connecting sleeve 11 and the second connecting sleeve 12 to avoid loosening.

[0061] Reference Figure 7An air passage 145 is provided in the guide rod 141, one end of the air passage 145 penetrates the outer wall of the guide rod 141, and the push block 142 corresponds to the portion of the air passage 145 penetrating the outer wall of the guide rod 141. An air charging pipe 149 is fixedly connected to the other side of the support block 14, which is used to automatically fill the first connecting sleeve 11 and the second connecting sleeve 12 with protective gas when the first connecting sleeve 11 and the second connecting sleeve 12 are connected. In this embodiment, the protective gas is preferably nitrogen;

[0062] The device opens an air passage 145 in the guide rod 141. When the push-pull block 142 is not pushed by the connecting block 2, the push-pull block 142 can block the portion of the air passage 145 that passes through the outer wall of the guide rod 141. Therefore, when the device is not in use, the push-pull block 142 can close the air passage 145. When the first connecting sleeve 11 and the second connecting sleeve 12 are close to each other and locked, the connecting block 2 can open the air passage 145 when pushing the push-pull block 142 to further separate the pair of first wire cores 112 and the pair of second wire cores 32. As a result, the gas charging tube 149 connected to the external gas cylinder through the pipeline automatically fills the protective gas into the connected first connecting sleeve 11 and the second connecting sleeve 12, thereby effectively protecting the first wire core 112, the second wire core 32 and the terminal 23 in the first connecting sleeve 11 and the second connecting sleeve 12, and improving the oxidation resistance.

[0063] At the same time, during the process of connecting the first connecting sleeve 11 and the second connecting sleeve 12, there is still a gap between the first connecting sleeve 11 and the second connecting sleeve 12, which can discharge the air originally in the first connecting sleeve 11 and the second connecting sleeve 12 when the protective gas is filled, thereby further improving the oxidation resistance and thus improving the service life;

[0064] Therefore, the push block 142 provided in the device can not only effectively separate and isolate the first wire core 112 and the pair of second wire cores 32, but also automatically control the opening and closing of the inflation tube 149;

[0065] It should be understood that a connecting hole 148 is provided on the expansion block 14 to facilitate the charging of protective gas into the location where the separation box 15 is located.

[0066] Reference Figure 2 , Figure 3 , Figure 4 , Figure 6 A threaded sleeve 10 is sleeved on the outer periphery of the first connecting sleeve 11, an inner diameter of one end of the threaded sleeve 10 is provided with an internal thread, and an outer wall of one end of the second connecting sleeve 12 is provided with an external thread. The first connecting sleeve 11 and the second connecting sleeve 12 are locked and connected by the threaded sleeve 10. By rotating the threaded sleeve 10, the threaded sleeve 10 is threadedly connected to the second connecting sleeve 12, which can conveniently realize the locking connection between the first connecting sleeve 11 and the second connecting sleeve 12;

[0067] It should be noted that a convex edge is provided on the outer periphery of the first connecting sleeve 11, which can prevent the threaded sleeve 10 on the first connecting sleeve 11 from detaching from the first connecting sleeve 11 when the threaded sleeve 10 is connected to the second connecting sleeve 12. At the same time, sealing rings are provided between the threaded sleeve 10 and the first connecting sleeve 11 and the second connecting sleeve 12.

[0068] Reference Figure 5 , Fig.11 , two first rubber sleeves 151 and a second rubber sleeve 152 are fixedly connected to the separation box 15, the first rubber sleeve 151 corresponds to the first wire 111 and the second wire 31, respectively, and the second rubber sleeve 152 corresponds to the inflation tube 149 on the expansion block 14;

[0069] The first rubber sleeve 151 and the second rubber sleeve 152 provided on the separation box 15 can be sleeved on the first wire 111 , the second wire 31 and the inflation tube 149 to further prevent gas leakage after the protective gas is filled.

[0070] Reference Figure 7 A limited sliding groove 154 is provided on the inner wall of the separation box 15, and a sliding plate 153 is slidably connected in the limited sliding groove 154. The outer walls of the first rubber sleeve 151 and the second rubber sleeve 152 are both tapered. The sliding plate 153 slides on the first rubber sleeve 151 and the second rubber sleeve 152. When the first connecting sleeve 11 and the second connecting sleeve 12 are filled with protective gas, the protective gas pushes the sliding plate 153 to the bottom of the separation box 15 to contract and squeeze the first rubber sleeve 151 and the second rubber sleeve 152;

[0071] When the protective gas is filled into the first connecting sleeve 11 and the second connecting sleeve 12 after connection, the filled protective gas has a certain air pressure, and the air pressure can push the sliding plate 153 to move toward the bottom of the separation box 15. The device sets the outer periphery of the first rubber sleeve 151 and the second rubber sleeve 152 to be conical. During the movement of the sliding plate 153, the first rubber sleeve 151 and the second rubber sleeve 152 can be gradually squeezed to shrink and hold the corresponding first wire 111, the second wire 31 and the inflation tube 149, which can further reduce the gap between the first rubber sleeve 151, the second rubber sleeve 152 and the first wire 111, the second wire 31 and the inflation tube 149.

[0072] Therefore, the device can not only open the first wire core 112, the second wire core 32 and the part between the insulating outer skin on the first wire 111, the second wire 31 again by setting up the separation box 15, so that a pair of first wire cores 112 and a pair of second wire cores 32 are separated from each other, but also can further reduce the gap between the first rubber sleeve 151, the second rubber sleeve 152 and the corresponding first wire 111, the second wire 31 and the inflation tube 149 by using the gas pressure of the injected protective gas when injecting the protective gas, thereby further avoiding gas leakage and improving the effect of injecting the protective gas.

[0073] Example 2: Reference Figure 1-Figure 11 A method for using a grid fault ride-through control device of a flexible direct current transmission system mainly comprises the following steps:

[0074] S1. Put the locking ring 13 on the first wiring harness 1 and the second wiring harness 3 in sequence, then put the separation box 15 on the pair of first wires 111 on the first wiring harness 1 and the pair of second wires 31 on the second wiring harness 3 in sequence, and then put the pair of first wires 111 and the pair of second wires 31 on the second wiring harness 3 into the corresponding first connecting sleeve 11 and the second connecting sleeve 12 respectively;

[0075] S2, insert the first wire core 112 and the second wire core 32 into the two ends of the terminal 23 respectively, and then insert the two ends of the connecting block 2 into the guide rods 141 in the first connecting sleeve 11 and the second connecting sleeve 12 respectively;

[0076] S3, bringing the first connecting sleeve 11 and the second connecting sleeve 12 close to each other and locking them, so as to achieve the connection between the first wiring harness 1 and the second wiring harness 3.

[0077] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the present invention can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A grid fault ride-through control device for a flexible DC power transmission system, comprising a controller module for monitoring grid status, calculating control strategies and issuing corresponding instructions; a fault ride-through control module for identifying grid faults and taking corresponding measures; and a monitoring module for real-time monitoring of voltage, current and frequency of the grid; A communication module is used for data transmission and communication between the controllers or between the controller and the monitoring module, and is characterized by further comprising: The circuits connected between the controller module, the fault-through control module, the monitoring module, and the communication module are all detachable two-stage circuits, and the two-stage circuits respectively include a first wiring harness (1) with one end exposed and a second wiring harness (3), one end of the first wiring harness (1) forms a pair of first electric wires (111) with exposed first wire cores (112), and one end of the second wiring harness (3) forms a pair of second electric wires (31) with exposed second wire cores (32), and the first electric wires (111) and the second electric wires (31) are connected via a first connecting sleeve (11) and a second connecting sleeve (12); A support block (14) is respectively arranged in the first connection sleeve (11) and the second connection sleeve (12); a pair of the first wire cores (112) respectively pass through two through holes (140) opened in the support block (14) and extending away from each other; A separation box (15) is disposed at one end of the first connection sleeve (11) and the second connection sleeve (12) that is away from each other, and the first electric wire (111) and the second electric wire (31) with insulating sheaths pass through the separation box (15) respectively; A connection block (2) located between the first connection sleeve (11) and the second connection sleeve (12), the connection block (2) being provided with two connection posts (23) for electrically connecting a pair of the first wire core (112) and the second wire core (32); The connection block (2) is symmetrically provided with slots (22), one side of the slot (22) of the terminal post (23) is plugged into the slot (22), and a through slot (21) is provided in the connection block (2); A guide rod (141) is fixedly connected to one side of the expansion block (14), and a push block (142) is slidably connected to the guide rod (141). The push block (142) is connected to the expansion block (14) via a spring (147). The outer surface of the push block (142) is in contact with the corresponding first wire core (112) and the second wire core (32). When the two ends of the first connecting sleeve (11) and the second connecting sleeve (12) are approaching each other, the connecting block (2) pushes the push block (142) in the first connecting sleeve (11) and the second connecting sleeve (12) respectively, so that the push block (142) approaches the corresponding first wire harness (1) and the second wire harness (3).

2. A grid fault ride-through control device for a flexible DC transmission system according to claim 1, characterized in that: The spring (147) is made of plastic material.

3. A grid fault ride-through control device for a flexible DC transmission system according to claim 1, characterized in that: An isolating filling sleeve (146) is fixedly connected between the push-pushing block (142) and the opening block (14); the isolating filling sleeve (146) is sleeved on a spring (147); a through-shaped limiting groove (143) is symmetrically provided on the outer circumference of the push-pushing block (142); an annular releasing groove (144) is provided on the circumference of the push-pushing block (142); the depth of the releasing groove (144) is greater than the depth of the limiting groove (143).

4. A grid fault ride-through control device for a flexible DC transmission system according to claim 1, characterized in that: An air passage (145) is provided in the guide rod (141), one end of the air passage (145) penetrates the outer wall of the guide rod (141), the push-pushing block (142) corresponds to the portion where the air passage (145) penetrates the outer wall of the guide rod (141), and an air filling pipe (149) is fixedly connected to the other side of the expansion block (14) for automatically filling the first connecting sleeve (11) and the second connecting sleeve (12) with protective gas when the first connecting sleeve (11) and the second connecting sleeve (12) are connected.

5. A grid fault ride-through control device for a flexible DC transmission system according to claim 4, characterized in that: A threaded sleeve (10) is sleeved on the outer circumference of the first connecting sleeve (11), an inner diameter of one end of the threaded sleeve (10) is provided with an internal thread, and an outer wall of one end of the second connecting sleeve (12) is provided with an external thread, and the first connecting sleeve (11) and the second connecting sleeve (12) are locked and connected via the threaded sleeve (10).

6. A grid fault ride-through control device for a flexible DC transmission system according to claim 5, characterized in that: Two first rubber sleeves (151) and a second rubber sleeve (152) are respectively fixedly connected to the separation box (15); the first rubber sleeves (151) correspond to the first electric wires (111) and the second electric wires (31), respectively; and the second rubber sleeve (152) corresponds to the inflation tube (149) on the expansion block (14).

7. A grid fault ride-through control device for a flexible DC transmission system according to claim 6, characterized in that: A limiting slide groove (154) is provided on the inner wall of the separation box (15), and a sliding plate (153) is slidably connected in the limiting slide groove (154). The outer walls of the first rubber sleeve (151) and the second rubber sleeve (152) are both tapered. The sliding plate (153) slides on the first rubber sleeve (151) and the second rubber sleeve (152). When the first connecting sleeve (11) and the second connecting sleeve (12) are filled with protective gas, the protective gas pushes the sliding plate (153) toward the bottom of the separation box (15) to shrink and squeeze the first rubber sleeve (151) and the second rubber sleeve (152).

8. A method for using a flexible DC power transmission system grid fault ride-through control device, comprising the flexible DC power transmission system grid fault ride-through control device according to claim 7, characterized in that: The main steps include: S1. Insert the locking ring (13) on the first wiring harness (1) and the second wiring harness (3) in sequence, then insert the separation box (15) on the pair of first wires (111) on the first wiring harness (1) and the pair of second wires (31) on the second wiring harness (3) in sequence, and then insert the pair of first wires (111) and the pair of second wires (31) on the second wiring harness (3) into the corresponding first connecting sleeve (11) and the second connecting sleeve (12) respectively; S2, inserting the first wire core (112) and the second wire core (32) into the two ends of the terminal (23), respectively, and then inserting the two ends of the connection block (2) into the guide rods (141) in the first connection sleeve (11) and the second connection sleeve (12), respectively; S3. Bringing the first connecting sleeve (11) and the second connecting sleeve (12) close together and locking them, thereby achieving connection between the first wiring harness (1) and the second wiring harness (3).

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