Digital dry-type mutual inductor and isolating switch

Abstract

The invention relates to the field of high-voltage electric appliances, in particular to a digital dry-type mutual inductor and an isolating switch comprising the digital dry-type mutual inductor. The digital dry-type voltage and current transformer comprises a high-voltage chamber, an insulating column, a conductor and an optical fiber sensitive ring which are arranged in the high-voltage chamber, and input and output optical fibers, the optical fiber sensitive ring is sleeved outside the conductor, one end of the input and output optical fiber is connected with the optical fiber sensitive ring, and the other end is used for transmitting optical signals to realize the function of the current transformer; the high-voltage chamber is fixedly arranged at one end of the insulating column, the insulating column comprises a capacitive voltage-dividing insulating core body wrapping the input optical fiber and the output optical fiber, and a plurality of capacitive screens are arranged in the capacitive voltage-dividing insulating core body, and the capacitive screens and the insulating layers are alternately arranged in a surrounding mode; the digital dry-type mutual inductor and the isolating switch are small in occupied space, convenient to overhaul and high in safety.

Description

Technical Field

[0001] The invention relates to the field of high-voltage electrical appliances, and in particular to a digital dry-type transformer and an isolating switch comprising the digital dry-type transformer. Background Art

[0002] The existing insulated chamber type current transformer achieves insulation of the sensor coil by setting a high voltage chamber filled with air or a high voltage chamber filled with gelatinous insulating material, thereby ensuring the normal operation of the current transformer; this type of current transformer has large specifications and occupies a large space. In addition, it also has the problems of inconvenient maintenance and high production and use risks. Summary of the invention

[0003] The object of the present invention is to overcome at least one defect of the prior art and to provide a digital dry-type transformer and a disconnector including the digital dry-type transformer, which occupy a small space, are easy to maintain and have high safety.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A digital dry-type transformer, the digital dry-type voltage and current transformer comprising a high voltage chamber, an insulating column, a conductor and an optical fiber sensitive ring arranged in the high voltage chamber, and input and output optical fibers; the optical fiber sensitive ring is sleeved on the outside of the conductor, one end of the input and output optical fibers is connected to the optical fiber sensitive ring and the other end is used to transmit optical signals to realize the current transformer function; the high voltage chamber is fixedly arranged on one end of the insulating column, the insulating column comprises a capacitive voltage divider insulating core wrapped around the outside of the input and output optical fibers, and a plurality of capacitive screens are arranged in the capacitive voltage divider insulating core and alternately surrounded by an insulating layer.

[0006] Furthermore, the input and output optical fibers are polarization-maintaining delay optical fibers.

[0007] Furthermore, the optical fiber sensitive ring includes a sensing optical fiber, a reflector and a λ / 4 wave plate.

[0008] Furthermore, the multiple capacitor screens include a voltage-equalizing capacitor screen for forming a voltage-equalizing capacitor C1 and a voltage-dividing capacitor screen for forming a voltage-dividing capacitor C2; the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 are connected in series to form a capacitive voltage divider, and a lead wire is extended between the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 to realize a voltage transformer function.

[0009] Furthermore, the multiple capacitive screens also include a shielding capacitive screen for forming a shielding capacitor C3, and the shielding capacitor C3 wraps at least a portion of the voltage-sharing capacitive screen to shield external interference signals.

[0010] Furthermore, one end of the capacitive voltage-dividing insulating core body close to the conductor is the upper end of the core body, the other end of the capacitive voltage-dividing insulating core body is the lower end of the core body, and the direction from the lower end of the core body to the upper end of the core body is the first direction;

[0011] In the voltage-equalizing capacitor C1, multiple voltage-equalizing capacitor screens are sequentially sleeved outside the input and output optical fibers along the radial direction of the capacitive voltage-dividing insulating core, and the voltage-equalizing capacitor screens from the innermost layer to the outermost layer are sequentially offset and stacked along the first direction.

[0012] Furthermore, the direction from the upper end of the core to the lower end of the core is the second direction;

[0013] In the shielding capacitor C3, multiple shielding capacitor screens are sequentially sleeved outside the voltage-equalizing capacitor C1 along the radial direction of the capacitor voltage-dividing insulating core, and the innermost shielding capacitor screen to the outermost shielding capacitor screen are sequentially offset and stacked along the second direction.

[0014] Furthermore, in the radial direction of the capacitive voltage-dividing insulating core, the outermost voltage-sharing capacitor screen and the innermost shielding capacitor screen are the same capacitor screen, and the multiple voltage-sharing capacitor screens and the multiple shielding capacitor screens are in an inverted V-shaped structure as a whole.

[0015] Furthermore, in the voltage-dividing capacitor C2, a plurality of voltage-dividing capacitor screens are sequentially sleeved outside the outermost shielding capacitor screen along the radial direction of the capacitor voltage-dividing insulating core.

[0016] Furthermore, the outermost voltage-equalizing capacitor screen and the innermost shielding capacitor screen are at the same potential as the conductor; the innermost voltage-equalizing capacitor screen is connected to ground potential through the voltage-dividing capacitor C2, and the outermost shielding capacitor screen is connected to ground potential.

[0017] Furthermore, the insulating column also includes a silicone rubber shed sleeved outside the capacitive voltage-dividing insulating core;

[0018] The digital dry-type mutual inductor also includes a grounding flange, which and the conductor are fixedly arranged on the two ends of the insulating column respectively. A secondary output interface is provided on the grounding flange. One end of the input and output optical fiber is connected to the optical fiber sensitive ring, and the other end is connected to the secondary output interface. The lead wires extending between the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 are connected to the secondary output interface.

[0019] Furthermore, the digital dry-type mutual inductor also includes a circuit connection structure, and each end of the conductor is connected to a group of circuit connection structures.

[0020] Furthermore, the input and output optical fibers and the capacitive voltage-dividing insulating core are designed and manufactured in an integrated manner to form a closed, solid, integrated structure.

[0021] Furthermore, the input and output optical fibers are embedded in the center of the capacitive voltage divider insulating core.

[0022] Furthermore, the input and output optical fibers and the capacitive voltage-divider insulating core are manufactured by the following method: the input and output optical fibers are wrapped with epoxy resin fiber cloth and impregnated with epoxy resin, and input and output optical fiber rods are obtained after curing; and the capacitive screen and the insulating layer are alternately wrapped around the outside of the input and output optical fiber rods, thereby forming a capacitive voltage-divider insulating core wrapped around the outside of the input and output optical fiber rods.

[0023] A disconnector comprises the digital dry-type mutual inductor.

[0024] Furthermore, the isolating switch also includes at least one group of moving contacts, a transmission column, and a rotating mechanism; the transmission column and the insulating column are arranged side by side and spaced apart, the moving contact is arranged on one end of the transmission column, and the rotating mechanism is transmission-connected to the other end of the transmission column, and the rotating mechanism drives the moving contact to rotate through the transmission column so that the static contact connected to the conductor is closed and disconnected.

[0025] The digital dry-type transformer and disconnector of the present invention, wherein the digital dry-type transformer adopts an optical fiber sensitive ring to replace the traditional sensor coil, and cooperates with the input and output optical fibers to realize the current transformer function, thereby solving the problems of large volume and high insulation difficulty of the existing current transformer using sensor coils, and the monitoring sensitivity and accuracy are higher; moreover, the high-voltage chamber does not require filling, sealing and other process processes, avoiding explosions caused by process defects or leakage during the production process and use, and no maintenance is required.

[0026] In addition, the digital dry-type transformer of this embodiment has an insulating core that realizes the function of a voltage transformer at the same time, thereby improving the integration and integration level, having a small overall size, high sensitivity and accuracy, and reliable performance.

[0027] In addition, the input and output optical fibers are designed and manufactured in an integrated manner with the capacitor voltage-dividing insulating core, which reduces the number of parts and provides reliable support and protection for the input and output optical fibers, ensuring their stable and reliable operation. Furthermore, the input and output optical fibers are embedded in the center of the capacitor voltage-dividing insulating core, that is, the capacitor screen and the insulating layer of the capacitor voltage-dividing insulating core are wrapped around the outside of the input and output optical fibers. Compared with the capacitor voltage-dividing insulating core with a cavity formed in the center, the input and output optical fibers occupy the cavity position and form an integrated structure with the capacitor voltage-dividing insulating core, thereby achieving the goal of not requiring inner cavity filling and avoiding explosion accidents caused by defects in the sealing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a digital dry-type mutual inductor of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the isolating switch of the present invention;

[0030] Description of Reference Numerals

[0031] h high voltage chamber; 1 circuit connection structure; 2 insulating column; 3 conductor; 4 optical fiber sensitive ring; 5 input and output optical fiber; 6 insulating core; 7 silicone rubber shed; 8 equalizing capacitor screen; 9 shielding capacitor screen; 10 dividing capacitor screen; 11 grounding flange; 12 secondary output port; 13 moving contact; 14 arrester valve plate; 15 transmission column; 16 rotating mechanism. DETAILED DESCRIPTION

[0032] The specific implementation of the digital dry-type transformer and disconnector of the present invention is further described below in conjunction with the embodiments given in the accompanying drawings. The digital dry-type transformer of the present invention is not limited to the description of the following embodiments.

[0033] like Figure 1 FIG. 1 is an embodiment of the digital dry-type transformer of the present invention.

[0034] The digital dry-type transformer of this embodiment includes a high-voltage chamber h, an insulating column 2, a conductor 3 and an optical fiber sensitive ring 4 arranged in the high-voltage chamber h, and input and output optical fibers 5; the optical fiber sensitive ring 4 is sleeved on the outside of the conductor 3, one end of the input and output optical fiber 5 is connected to the optical fiber sensitive ring 4 and the other end is used to transmit (input and output) optical signals, so as to realize the function of a current transformer; the high-voltage chamber h is fixedly arranged on one end of the insulating column 2, and the insulating column 2 includes a capacitive voltage-dividing insulating core 6 wrapped around the outside of the input and output optical fibers 5, and a plurality of capacitive screens are arranged alternately surrounding the insulating layer in the capacitive voltage-dividing insulating core 6; the high-voltage chamber h is fixedly arranged on one end of the insulating column 2 and one end of the capacitive voltage-dividing insulating core 6 is inserted into the high-voltage chamber h.

[0035] Furthermore, the conductor 3 is fixed on the high voltage chamber h. Furthermore, both ends of the conductor 3 are fixed on a pair of side walls of the high voltage chamber h through two fixing flanges respectively, and the optical fiber sensitive ring 4 is sleeved on the outside of the conductor 3 .

[0036] The digital dry-type current transformer of the present embodiment adopts an optical fiber sensitive ring 4 to replace the traditional sensor coil, and cooperates with the input and output optical fibers 5 to realize the current transformer function, thereby solving the problems of large size and high insulation difficulty of the existing current transformer using sensor coils, and the monitoring sensitivity and accuracy are higher; moreover, since the optical fiber sensitive ring 4 is made of fully insulating material, the high-voltage chamber h does not need to be filled, sealed, and other process flows, thus avoiding explosions caused by process defects or leakage during the production process and use, and no maintenance is required.

[0037] Furthermore, the input and output optical fibers 5 are polarization-maintaining delay optical fibers, which have the following technical effects:

[0038] 1. Solved the problem of polarization state change: Research has found that reliable optical fiber can better ensure that the positive direction of linear polarization remains unchanged, effectively improve the coherent signal-to-noise ratio, and effectively achieve high-precision and accurate measurement of physical quantities during use. It can better maintain the stable state of light speed propagation, that is, it can effectively avoid environmental interference and enhance the stability of its optical fiber transmission. After avoiding deviation, it can also ensure higher output quality, and the quality of optical fiber output is comprehensively improved, reducing the loss and reflection of the transmission optical fiber.

[0039] 2. Smaller transmission loss: Research has found that reliable optical fiber has higher stability and consistency. Under the influence of the same optical fiber length and diameter, its own transmission loss is lower. During use, the additional loss can be reduced to better ensure the polarization state of the transmission line. Therefore, during use, the sensing sensitivity of optical fiber communication and optical fiber sensors can be higher, and even in the long-distance optical fiber transmission link, the transmission effect of photoelectric signals can be better maintained.

[0040] In general, polarization-maintaining delayed-transmission optical fiber has better anti-electromagnetic interference performance and transmission effect, can more comprehensively improve the quality of optoelectronic information transmission, and better adapt to the high-performance requirements of optical fiber in complex fields.

[0041] Specifically, the two ends of the polarization-maintaining delay optical fiber are respectively connected to an optical fiber sensitive ring and a signal processing unit, the signal processing unit is electrically connected to the ground potential, the polarization-maintaining delay optical fiber transmits an optical signal and generates a delay time, the signal processing unit processes the signal input by the polarization-maintaining delay optical fiber to obtain a current value, and the signal processing unit can be implemented by existing technologies and will not be described in detail here.

[0042] The optical fiber sensitive ring 4 includes a sensing optical fiber, a reflector and a λ / 4 wave plate, which is the prior art in the art and will not be described in detail here.

[0043] Furthermore, in this embodiment, the input and output optical fibers 5 are designed and manufactured in an integrated manner with the capacitor voltage-dividing insulating core 6 to form a closed solid integrated structure, which reduces the number of parts and avoids explosion accidents caused by defects in the sealing process, and provides reliable support and protection for the input and output optical fibers 5 to ensure their stable and reliable operation. Furthermore, the input and output optical fibers 5 can be embedded in any position in the capacitor voltage-dividing insulating core 6 during the manufacturing process of the capacitor voltage-dividing insulating core 6 to form a closed solid integrated structure, that is, in the process of winding the capacitor screen and the insulating layer, the input and output optical fibers 5 are embedded at any position; the input and output optical fibers 5 are preferably embedded in the center of the capacitor voltage-dividing insulating core 6, or embedded between the voltage-equalizing capacitor C1 and the shielding capacitor C3 of the capacitor voltage-dividing insulating core 6.

[0044] Specifically, in this embodiment, the input and output optical fibers 5 are embedded in the center of the capacitive voltage-dividing insulating core 6, that is, the capacitive screen and the insulating layer of the capacitive voltage-dividing insulating core 6 are wrapped around the outside of the input and output optical fibers 5. Compared with the capacitive voltage-dividing insulating core 6 with a cavity formed in the center, the input and output optical fibers 5 occupy the cavity position and form an integrated structure with the capacitive voltage-dividing insulating core 6, so that no inner cavity filling is required, and explosion accidents caused by sealing process defects are avoided. The following is a method for making the integrated structure of the input and output optical fibers 5 and the capacitive voltage-dividing insulating core 6: the input and output optical fibers 5 are wrapped around epoxy resin fiber cloth and impregnated with epoxy resin, and after curing, input and output optical fiber rods with necessary structural strength and outer diameter dimensions are obtained; the capacitive screen and the insulating layer are alternately wrapped around the outside of the input and output optical fiber rods, so as to form a capacitive voltage-dividing insulating core 6 wrapped around the outside of the input and output optical fiber rods.

[0045] like Figure 1 As shown, in the insulating column 2, the multiple capacitor screens of the capacitor voltage-dividing insulating core 6 include a voltage-dividing capacitor screen 8 for forming a voltage-dividing capacitor C1, a shielding capacitor screen 9 for forming a shielding capacitor C3, and a voltage-dividing capacitor screen 10 for forming a voltage-dividing capacitor C2; the voltage-dividing capacitor C1 and the voltage-dividing capacitor C2 are connected in series to form a capacitor voltage divider, and a lead is drawn between the voltage-dividing capacitor C1 and the voltage-dividing capacitor C2 to realize the voltage transformer function; the shielding capacitor C3 wraps at least part of the voltage-dividing capacitor screen 8 to shield external interference signals. In the digital dry-type transformer of this embodiment, the capacitor voltage-dividing insulating core 6 realizes the voltage transformer function at the same time, improves the integration and integration, has a small overall specification and volume, high sensitivity and accuracy, and reliable performance. Further, after the voltage-dividing capacitor C1 and the voltage-dividing capacitor C2 are connected in series, they are connected in parallel with the shielding capacitor C3; the voltage-dividing capacitor C1 and the voltage-dividing capacitor C2 are connected in series between the ground potential and the high potential connected to the conductor 3; the shielding capacitor C3 is connected in series between the ground potential and the high potential connected to the conductor 3.

[0046] like Figure 1As shown, it is an implementation method of the capacitive voltage-dividing insulating core 6: the end of the capacitive voltage-dividing insulating core 6 close to the conductor 3 is the upper end of the core, the other end of the capacitive voltage-dividing insulating core 6 is the lower end of the core, the direction from the lower end of the core to the upper end of the core is the first direction, and the direction from the upper end of the core to the lower end of the core is the second direction. In the voltage-equalizing capacitor C1, a plurality of voltage-equalizing capacitor screens 8 are sequentially sleeved on the outside of the input and output optical fibers 5 along the radial direction of the capacitive voltage-dividing insulating core 6, and the innermost voltage-equalizing capacitor screen 8 to the outermost voltage-equalizing capacitor screen 8 are sequentially offset and stacked along the first direction, that is, in two adjacent voltage-equalizing capacitor screens 8, the voltage-equalizing capacitor screen 8 located on the outside is offset toward the upper end of the core relative to the voltage-equalizing capacitor screen 8 located on the inside, and one end of the voltage-equalizing capacitor screen 8 located on the outside close to the lower end of the core is sleeved on the outside of one end of the voltage-equalizing capacitor screen 8 located on the inside close to the upper end of the core. In the shielding capacitor C3, multiple shielding capacitor screens 9 are sequentially sleeved outside the voltage-equalizing capacitor C1 along the radial direction of the capacitor voltage-dividing insulating core 6, and the innermost shielding capacitor screen 9 to the outermost shielding capacitor screen 9 are sequentially offset and stacked along the second direction, that is, of the two adjacent shielding capacitor screens 9, the outer shielding capacitor screen 9 is offset toward the lower end of the core relative to the inner shielding capacitor screen 9, and one end of the outer shielding capacitor screen 9 close to the upper end of the core is sleeved outside one end of the inner shielding capacitor screen 9 close to the lower end of the core. Figure 1 As shown, in the voltage-dividing capacitor C2, a plurality of voltage-dividing capacitor screens 10 are sequentially sleeved outside the outermost shielding capacitor screen 9 along the radial direction of the voltage-dividing capacitor insulating core 6.

[0047] Further, such as Figure 1 As shown, in the radial direction of the capacitive voltage-dividing insulating core 6, the outermost voltage-sharing capacitor screen 8 and the innermost shielding capacitor screen 9 are the same capacitor screen, and the multiple voltage-sharing capacitor screens 8 and the multiple shielding capacitor screens 9 are in an inverted V-shaped structure as a whole.

[0048] Furthermore, the outermost voltage-equalizing capacitor screen 8 and the innermost shielding capacitor screen 9 are at the same potential as the conductor 3; the innermost voltage-equalizing capacitor screen 8 is connected to the ground potential through the voltage-dividing capacitor C2, and the outermost shielding capacitor screen 9 is connected to the ground potential. Specifically, the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 are connected in series between the conductor 3 and the ground potential, and the shielding capacitor C3 is connected in series between the conductor 3 and the ground potential, that is, the shielding capacitor C3 is connected in parallel with the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 connected in series.

[0049] It should be pointed out that the arrangement of the voltage-sharing capacitor screen 8, the shielding capacitor screen 9 and the voltage-sharing capacitor screen 10 in the capacitive voltage-sharing insulating core 6 is not limited to the above-mentioned one, and other methods recorded in the prior art can also be adopted, which will not be listed and described one by one here. In addition, as other embodiments, the capacitive voltage-sharing insulating core 6 can also be provided with only the voltage-sharing capacitor C1, without the voltage-sharing capacitor C2 and the shielding capacitor C3, or only the voltage-sharing capacitor C1 and the voltage-sharing capacitor C2, without the shielding capacitor C3; or other capacitors can also be provided to achieve other functions, all of which are possible.

[0050] like Figure 1 As shown, the insulating column 2 also includes a silicone rubber shed 7 sleeved on the outside of the capacitor voltage-dividing insulating core 6. The digital dry-type voltage and current transformer of this embodiment also includes a grounding flange 11, and the grounding flange 11 and the conductor 3 are respectively fixed on the two ends of the insulating column 2. A secondary output interface 12 is provided on the grounding flange 11. One end of the input and output optical fiber 5 is connected to the optical fiber sensitive ring 4 and the other end is preferably connected to the secondary output interface 12. The lead wire between the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 is preferably connected to the secondary output interface 12.

[0051] like Figure 1 and 2 As shown, the digital dry-type transformer in this embodiment further includes a circuit connection structure 1, and a group of circuit connection structures 1 are connected to each end of the conductor 3 to establish an electrical connection with the external circuit to be monitored. Further, the circuit connection structure 1 is a wiring terminal 1a or a contact structure 1b.

[0052] Specifically, Figure 1 As shown, the two ends of the conductor 3 are respectively connected to a group of wiring terminals 1a, so that the digital dry-type transformer of this embodiment can be connected to any circuit that requires voltage and current monitoring / detection.

[0053] like Figure 2 FIG. 1 is an embodiment of the isolating switch of the present invention.

[0054] The isolating switch of this embodiment includes the digital dry-type mutual inductor. Further, the isolating switch of this embodiment also includes at least one set of moving contacts 13, a transmission column 15, and a rotating mechanism 16; the transmission column 15 and the insulating column 2 are arranged side by side and spaced apart, the moving contact 13 is arranged on one end of the transmission column 15, and the rotating mechanism 16 is connected to the other end of the transmission column 15 by transmission, and the rotating mechanism 16 drives the moving contact 13 to rotate through the transmission column 15 so that the static contact connected to the conductor 3 is closed and disconnected.

[0055] Specifically, one end of the moving contact 13 is set on the transmission column 15, and the other end is connected to the static contact of the conductor 3 for closing and disconnecting; the two ends of the conductor 3 are respectively connected to a group of circuit connection structures 1, one group of circuit connection structures 1 is the wiring terminal 1a, and the other group of circuit connection structures 1 is the contact structure 1b, and the contact structure 1b serves as a static contact.

[0056] As another embodiment, the isolating switch includes two groups of static contacts, one group of static contacts comes from the digital dry-type mutual inductor of the present invention, and the other group of static contacts is arranged on the insulating column, the insulating column and the insulating column 2 are located on both radial sides of the transmission column 15, and the middle part of the moving contact 13 is arranged on the transmission column, and the two ends are respectively closed and disconnected with the two groups of static contacts.

[0057] Furthermore, the transmission column 15 also includes a plurality of valve plates arranged in the middle thereof, so that the transmission column 15 also has the function of a lightning arrester.

[0058] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate directions or positional relationships based on directions or positional relationships shown in the accompanying drawings, or directions or positional relationships that are usually placed when in use, and are only for the convenience of description, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions, and cannot be understood as indicating relative importance.

[0059] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A digital dry-type transformer, characterized in that: The digital dry-type voltage and current transformer comprises a high voltage chamber (h), an insulating column (2), a conductor (3) and an optical fiber sensitive ring (4) arranged inside the high voltage chamber (h), and input and output optical fibers (5); the optical fiber sensitive ring (4) is sleeved outside the conductor (3); one end of the input and output optical fibers (5) is connected to the optical fiber sensitive ring (4) and the other end is used to transmit optical signals, thereby realizing the function of a current transformer; the high voltage chamber (h) is fixedly arranged on one end of the insulating column (2); the insulating column (2) comprises a capacitive voltage divider insulating core (6) wrapped around the outside of the input and output optical fibers (5); a plurality of capacitive screens are arranged inside the capacitive voltage divider insulating core (6) and are alternately surrounded by insulating layers.

2. The digital dry-type mutual inductor according to claim 1, characterized in that: The input and output optical fibers (5) are polarization-maintaining delay optical fibers.

3. The digital dry-type mutual inductor according to claim 1, characterized in that: The optical fiber sensitive ring (4) comprises a sensing optical fiber, a reflector and a λ / 4 wave plate.

4. The digital dry-type transformer according to claim 1, characterized in that: The multiple capacitor screens include a voltage-equalizing capacitor screen (8) for forming a voltage-equalizing capacitor C1 and a voltage-dividing capacitor screen (10) for forming a voltage-dividing capacitor C2; the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 are connected in series to form a capacitive voltage divider, and a lead wire is drawn between the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 to realize a voltage transformer function.

5. The digital dry-type mutual inductor according to claim 4, characterized in that: The multiple capacitive screens also include a shielding capacitive screen (9) for forming a shielding capacitor C3, wherein the shielding capacitor C3 wraps at least a portion of the voltage-sharing capacitive screen (8) for shielding external interference signals.

6. The digital dry-type mutual inductor according to claim 5, characterized in that: One end of the capacitive voltage-dividing insulating core (6) close to the conductor (3) is the upper end of the core, the other end of the capacitive voltage-dividing insulating core (6) is the lower end of the core, and the direction from the lower end of the core to the upper end of the core is the first direction; In the voltage-equalizing capacitor C1, a plurality of voltage-equalizing capacitor screens (8) are sequentially sleeved outside the input and output optical fibers (5) along the radial direction of the capacitive voltage-dividing insulating core (6), and the voltage-equalizing capacitor screens (8) from the innermost layer to the outermost layer are sequentially offset and stacked along the first direction.

7. The digital dry-type transformer according to claim 6, characterized in that: The direction from the upper end of the core to the lower end of the core is the second direction; In the shielding capacitor C3, a plurality of shielding capacitor screens (9) are sequentially sleeved outside the voltage-equalizing capacitor C1 along the radial direction of the capacitor voltage-dividing insulating core (6), and the shielding capacitor screens (9) from the innermost layer to the outermost layer are sequentially offset and stacked along the second direction.

8. The digital dry-type mutual inductor according to claim 7, characterized in that: In the radial direction of the capacitive voltage-dividing insulating core (6), the outermost voltage-equalizing capacitor screen (8) and the innermost shielding capacitor screen (9) are the same capacitor screen, and the plurality of voltage-equalizing capacitor screens (8) and the plurality of shielding capacitor screens (9) are in an inverted V-shaped structure as a whole.

9. The digital dry-type mutual inductor according to claim 7, characterized in that: In the voltage-dividing capacitor C2, a plurality of voltage-dividing capacitor screens (10) are sequentially sleeved outside the outermost shielding capacitor screen (9) along the radial direction of the voltage-dividing capacitor insulating core (6); The outermost voltage-equalizing capacitor screen (8) and the innermost shielding capacitor screen (9) are at the same potential as the conductor (3); the innermost voltage-equalizing capacitor screen (8) is connected to the ground potential via the voltage-dividing capacitor C2, and the outermost shielding capacitor screen (9) is connected to the ground potential; The insulating column (2) further comprises a silicone rubber shed (7) sleeved on the outside of the capacitive voltage-dividing insulating core (6); The digital dry-type mutual inductor further comprises a grounding flange (11), wherein the grounding flange (11) and the conductor (3) are respectively fixedly arranged at two ends of the insulating column (2), a secondary output interface (12) is arranged on the grounding flange (11), one end of the input and output optical fiber (5) is connected to the optical fiber sensitive ring (4), and the other end is connected to the secondary output interface (12), and a lead wire extending between the voltage-equalizing capacitor C1 and the voltage-dividing capacitor C2 is connected to the secondary output interface (12); The digital dry-type mutual inductor further comprises a circuit connection structure (1), and two ends of the conductor (3) are each connected to a set of circuit connection structures (1); The input and output optical fibers (5) and the capacitive voltage-dividing insulating core (6) are designed and manufactured in an integrated manner to form a closed, solid, integrated structure; The input and output optical fibers (5) are embedded in the center of the capacitive voltage-dividing insulating core (6); The input and output optical fibers (5) and the capacitive voltage-dividing insulating core (6) are manufactured by the following method: the input and output optical fibers (5) are wrapped with epoxy resin fiber cloth and impregnated with epoxy resin, and after curing, input and output optical fiber rods are obtained; and capacitive screens and insulating layers are alternately wrapped around the outside of the input and output optical fiber rods, thereby forming a capacitive voltage-dividing insulating core (6) wrapped around the outside of the input and output optical fiber rods.

10. An isolating switch, characterized in that: The disconnector comprises at least one set of digital dry-type transformers according to any one of claims 1 to 9; The isolating switch further comprises at least one group of moving contacts (13), a transmission column (15), and a rotating mechanism (16); the transmission column (15) and the insulating column (2) are arranged side by side and spaced apart, the moving contact (13) is arranged on one end of the transmission column (15), and the rotating mechanism (16) is connected to the other end of the transmission column (15) by transmission, and the rotating mechanism (16) drives the moving contact (13) to rotate through the transmission column (15) so as to close and disconnect the static contact connected to the conductor (3).

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