Carrier communication coupling device and method for 110kV high-voltage power cable

Abstract

The invention discloses a carrier communication coupling device and method for a 110kV high-voltage power cable, and belongs to the field of power line carrier communication. Each of the two circuits comprises a signal amplification circuit, a carrier center frequency filtering and matching circuit, a protection circuit and a coupling capacitor which are connected in sequence, and the signal amplification circuit is connected with the transmitting end / receiving end; the coupling capacitor is connected with the cable shielding layer; the coupling circuit at the direct grounding box is also connected with a grounded wave-blocking inductor at the coupling capacitor; the signal amplification circuit ensures the intensity of carrier signals, the carrier center frequency filtering and matching circuit effectively filters interference signals and noise, and the protection circuit ensures the safe operation of the device in a high-voltage environment. By adopting the coupling device, the accurate and efficient transmission of the carrier signal can be realized under the condition that the normal work of the cable is not influenced.

Description

Technical Field

[0001] The invention belongs to the field of power line carrier communication, and in particular relates to a carrier communication coupling device and method for a 110kV high-voltage power cable. Background Art

[0002] In the power system, power line carrier communication has always been regarded as an efficient and economical means of communication. It uses existing power lines as a medium for data transmission, without the need to lay additional communication lines, significantly reducing communication costs. However, with the development of power systems, especially the widespread application of high-voltage power systems, traditional power line carrier communication technology faces unprecedented challenges.

[0003] The application of traditional carrier communication devices in low-voltage and medium-voltage power systems has been quite mature, and its technical principles and operating methods have been widely verified. However, in high-voltage power systems, due to the significant differences in the structure and transmission characteristics of power cables from traditional systems, traditional carrier communication methods are difficult to apply directly. The structure of high-voltage power cables is complex, including multiple parts such as conductors, insulation layers, metal sheaths (usually used as shielding layers) and outer sheaths. The above structural components together constitute the transmission channel of the cable and determine the electrical and physical properties of the cable. In high-voltage power cables, the shielding layer is an important part of the cable structure, and its main function is to provide electromagnetic shielding and fault current diversion. Electromagnetic shielding can effectively reduce the interference of the external environment on the internal signal of the cable and ensure the stability and reliability of the cable transmission signal; while the fault current diversion can quickly guide the fault current to the grounding system when a short circuit or grounding fault occurs in the cable, ensuring the safe operation of the power system. It is this important shielding layer that provides new possibilities for carrier communication in high-voltage power cables. Since the shielding layer is located outside the cable structure and is directly in contact with the external environment, it can be used as a natural signal transmission medium. Through reasonable signal coupling technology and transmission protocol design, the carrier signal can be effectively coupled to the shielding layer of the cable, and data can be transmitted through the shielding layer. This communication method not only utilizes the existing cable structure and avoids the trouble of laying additional communication lines, but also through the electromagnetic shielding effect of the shielding layer, it can significantly reduce the interference of power lines on data transmission and improve the stability and reliability of communication.

[0004] However, despite the many advantages of using cable shielding for carrier communication, there are still a series of technical challenges in practical applications. Since the electrical properties of the cable shielding layer are different from those of the conductor, special coupling devices and signal processing technologies need to be designed to ensure that the signal can be transmitted accurately and efficiently; that is, how to effectively couple the carrier signal to the cable shielding layer and realize the carrier signal transmission without affecting the normal operation of the cable is also a problem that needs to be solved. Summary of the invention

[0005] In order to overcome the above technical defects, the present invention provides a carrier communication coupling device and method for 110kV high-voltage power cable. The coupling device can realize accurate and efficient transmission of carrier signals without affecting the normal operation of the cable.

[0006] In order to achieve the above object, the present invention adopts the following technical contents:

[0007] A carrier communication coupling device for a 110kV high-voltage power cable, comprising a coupling circuit at a direct grounding box and a coupling circuit at a cross-connection box;

[0008] The coupling circuit at the direct grounding box includes a signal amplifying circuit connected to the transmitting end / receiving end; the signal amplifying circuit is sequentially connected to a carrier center frequency filtering and matching circuit, a protection circuit and a first coupling capacitor, the first coupling capacitor is connected to a cable shielding layer, and is also connected to a grounded wave-blocking inductor;

[0009] The coupling circuit at the cross-connection box includes a signal amplifying circuit connected to the transmitting end / receiving end; the signal amplifying circuit is sequentially connected to a carrier center frequency filtering and matching circuit, a protection circuit and a second coupling capacitor, and the second coupling capacitor is connected to the cable shielding layer;

[0010] The signal amplification circuit is used to amplify the carrier signal;

[0011] The carrier center frequency filtering and matching circuit is used for matching impedance and filtering out interference signals and noise;

[0012] The protection circuit is used to protect the safe operation of the carrier communication coupling device under high voltage conditions.

[0013] Furthermore, the direct grounding box coupling circuit includes a phase-to-ground direct grounding box coupling circuit and an inter-phase direct grounding box coupling circuit;

[0014] The first coupling capacitor of the coupling circuit at the phase-to-ground direct grounding box is connected to the cable shielding layer of one of the phases;

[0015] The first coupling capacitor of the coupling circuit at the phase-to-phase direct grounding box is respectively connected to the cable shielding layers of two phases.

[0016] Furthermore, the coupling circuit at the phase-to-ground direct grounding box includes a first coupling capacitor, and the first coupling capacitor is connected to the cable shielding layer of one of the phases;

[0017] The coupling circuit of the phase-to-phase direct grounding box includes two first coupling capacitors, one side of the two first coupling capacitors is respectively connected to the protection circuit, the other side of one first coupling capacitor is connected to the shielding layer of one phase cable among the three phases, and the other side of the other first coupling capacitor is connected to the shielding layer of another phase cable among the three phases.

[0018] Further, the coupling circuit at the cross-connection box includes a coupling circuit at the phase-to-ground cross-connection box and a coupling circuit at the phase-to-phase cross-connection box;

[0019] The second coupling capacitor of the coupling circuit at the phase-to-ground cross-connection box is connected to the cable shielding layer of one of the phases;

[0020] The second coupling capacitor of the coupling circuit at the phase-to-phase cross-connection box is respectively connected to the cable shielding layers of two phases.

[0021] Furthermore, the coupling circuit at the phase-to-ground cross-connection box includes a second coupling capacitor, and the second coupling capacitor is connected to the cable shielding layer of one of the phases;

[0022] The coupling circuit at the phase-to-phase cross-connection box includes two second coupling capacitors, one side of the two second coupling capacitors is respectively connected to the protection circuit, the other side of one second coupling capacitor is connected to the shielding layer of one phase cable among the three phases, and the other side of the other second coupling capacitor is connected to the shielding layer of another phase cable among the three phases.

[0023] Furthermore, the signal amplifying circuit includes an amplifier, and the amplifier is connected to the transmitting end / receiving end.

[0024] Further, the carrier center frequency filtering and matching circuit includes a connected transformer and a bandpass filter;

[0025] The bandpass filter includes a capacitor and an inductor connected in series and a capacitor and an inductor connected in parallel;

[0026] One side of the transformer is connected to the signal amplifying circuit, and the other side is connected to a capacitor and an inductor connected in series or to a capacitor and an inductor connected in parallel.

[0027] Furthermore, the protection circuit comprises a transient voltage suppression diode, one end of which is connected to the carrier center frequency filtering and matching circuit, and the other end of which is grounded.

[0028] Furthermore, the transmitting end adopts the Thevenin equivalent voltage source and equivalent internal resistance of the power amplifier circuit; the internal resistance adopts a fixed value protection resistor to limit the maximum output current of the power amplifier.

[0029] A working method of a carrier communication coupling device for a 110kV high-voltage power cable, based on the above-mentioned carrier communication coupling device, comprises:

[0030] The carrier signal sent by the transmitting end is transmitted to the cable shielding layer through the signal amplification circuit, the carrier center frequency filtering and matching circuit, the protection circuit and the coupling capacitor in sequence;

[0031] The carrier signal of the cable shielding layer is transmitted to the receiving end through the coupling capacitor, the protection circuit, the carrier center frequency filtering and matching circuit and the signal amplification circuit in sequence.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a carrier communication coupling device for a 110kV high-voltage power cable. The coupling device adopts a coupling circuit at a direct grounding box and a coupling circuit at a cross-connection box. Both circuits specifically include a signal amplification circuit, a carrier center frequency filtering and matching circuit, a protection circuit and a coupling capacitor which are connected in sequence. The signal amplification circuit is connected to a transmitting end / receiving end; the coupling capacitor is connected to a cable shielding layer; the coupling circuit at the direct grounding box also connects a grounded wave-blocking inductor to the coupling capacitor; the signal amplification circuit ensures the strength of the carrier signal, the carrier center frequency filtering and matching circuit effectively filters out interference signals and noise, and the protection circuit ensures the safe operation of the device under a high-voltage environment; the coupling device can realize accurate and efficient transmission of the carrier signal without affecting the normal operation of the cable; the device not only meets the communication needs of high-voltage power cables, but also provides new ideas and methods for the development of communication technology in the power industry.

[0034] Preferably, in the present invention, the coupling circuit at the directly grounded box adopts two modes, including a phase-to-ground directly grounded box coupling circuit and a phase-to-phase directly grounded box coupling circuit. The phase-to-ground directly grounded box coupling circuit is simpler and easier to implement, and the phase-to-phase directly grounded box coupling circuit is more stable and reliable. The setting of the two modes makes the coupling more precise and flexible, and improves the reliability and efficiency of communication.

[0035] Preferably, in the present invention, the coupling circuit at the cross-connection box adopts two modes, including a coupling circuit at the phase-to-ground cross-connection box and a coupling circuit at the phase-to-phase cross-connection box, so that the communication mode is more diverse and adapts to different communication requirements.

[0036] Preferably, in the present invention, the signal amplification circuit uses an amplifier connected to the transmitting end / receiving end, which ensures the amplification effect of the carrier signal and improves the communication quality.

[0037] Preferably, in the present invention, the carrier center frequency filtering and matching circuit includes a transformer and a bandpass filter, which ensures the frequency matching of the carrier signal and the filtering of the interference signal, further improving the accuracy and stability of the communication.

[0038] Preferably, in the present invention, the protection circuit uses a transient voltage suppression diode, which effectively prevents the voltage shock under the high voltage environment from damaging the device and ensures the safe operation of the device.

[0039] Preferably, in the present invention, the transmitting end, i.e., the signal source, adopts the Thevenin equivalent voltage source and the equivalent internal resistance, and limits the maximum output current by a protective resistor of a fixed value, thereby effectively preventing damage to the device or cable due to excessive power.

[0040] The present invention also provides a working method of a carrier communication coupling device for a 110kV high-voltage power cable. Based on the above-mentioned carrier communication coupling device for a 110kV high-voltage power cable, in this method, the carrier signal sent by the transmitting end is transmitted to the cable shielding layer through the signal amplification circuit, the carrier center frequency filtering and matching circuit, the protection circuit and the coupling capacitor in sequence; the carrier signal of the cable shielding layer is transmitted to the receiving end through the coupling capacitor, the protection circuit, the carrier center frequency filtering and matching circuit and the signal amplification circuit in sequence; the carrier signal is accurately and efficiently transmitted without affecting the normal operation of the cable; the method is simple in principle and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention;

[0042] Figure 2 An application scenario diagram of a phase-to-ground coupling wiring method of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of a composite coupling circuit of a carrier communication coupling device for a 110kV high-voltage power cable provided by an embodiment of the present invention at a directly grounded box in a phase-to-ground coupling wiring mode;

[0044] Figure 4 A schematic diagram of a composite coupling circuit of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention at a cross-connection box in a phase-to-ground coupling wiring mode;

[0045] Figure 5 A schematic diagram of a composite coupling circuit of a carrier communication coupling device for a 110kV high-voltage power cable provided by an embodiment of the present invention at a receiving end of a directly grounded box in a phase-to-ground coupling wiring mode;

[0046] Figure 6 A schematic diagram of a composite coupling circuit at the receiving end of a carrier communication coupling device for a 110kV high-voltage power cable provided by an embodiment of the present invention at a cross-connection box in a phase-to-ground coupling wiring mode;

[0047] Figure 7 An application scenario diagram of a phase-to-phase coupling wiring method of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention;

[0048] Figure 8 A schematic diagram of a composite coupling circuit of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention at a directly grounded box at the transmitting end in a phase-to-phase coupling wiring mode;

[0049] Fig. 9 A schematic diagram of a composite coupling circuit at the transmitting end of a carrier communication coupling device for a 110kV high-voltage power cable provided in an embodiment of the present invention at a cross-connection box in a phase-to-phase coupling wiring mode;

[0050] Fig.10 A schematic diagram of a composite coupling circuit of a carrier communication coupling device for a 110kV high-voltage power cable provided by an embodiment of the present invention at a receiving end of a direct grounding box in a phase-to-phase coupling wiring mode;

[0051] Fig.11 A schematic diagram of a composite coupling circuit at the receiving end of a carrier communication coupling device for a 110kV high-voltage power cable at a cross-connection box in a phase-to-phase coupling wiring mode provided in an embodiment of the present invention.

[0052] Reference numerals:

[0053] Amplifier-1; transformer-2; inductor-3; capacitor-4; transient voltage suppression diode-5; first coupling capacitor-6; second coupling capacitor-7; wave-blocking inductor-8. DETAILED DESCRIPTION

[0054] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0058] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0059] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0060] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] Example 1

[0062] As mentioned in the background technology, in high-voltage power systems, traditional carrier communication methods face many challenges due to the different structures and transmission characteristics of power cables. In high-voltage power cables, the shielding layer is usually used for electromagnetic shielding and fault current diversion, but it can also be used as a medium for signal transmission. Using the shielding layer for carrier communication can reduce the interference of power lines on data transmission and improve the stability and reliability of communication. However, how to effectively couple the carrier signal to the cable shielding layer and achieve efficient signal transmission without affecting the normal operation of the cable is a problem that needs to be solved.

[0063] In order to solve the above problems, the present invention provides a carrier communication coupling device and method for 110kV high-voltage power cable. The carrier communication coupling device can realize efficient and stable carrier signal transmission.

[0064] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0065] like Figure 1 As shown, this embodiment provides a carrier communication coupling device for a 110kV high-voltage power cable, comprising:

[0066] A coupling circuit at a direct grounding box and a coupling circuit at a cross-connection box; wherein one end of the coupling circuit at the direct grounding box and the coupling circuit at the cross-connection box are respectively connected to a power line data transmission device, and the other end is coupled to the shielding layer (metal sheath) of the high-voltage power cable, thereby realizing the transmission of the carrier signal.

[0067] The present embodiment provides a carrier communication coupling device for a 110kV high-voltage power cable, which is mainly composed of a carrier center frequency filtering and matching circuit for amplifying carrier signals, matching impedances, and filtering out interference signals and noises, and a protection circuit for protecting the safe operation of the carrier communication coupling device under high voltage conditions. The specific structure is as follows:

[0068] In this embodiment, the coupling circuit at the direct grounding box includes a signal amplification circuit, a carrier center frequency filtering and matching circuit, a protection circuit and a first coupling capacitor 6 connected in sequence; the signal amplification circuit is connected to the transmitting end / receiving end of the power line data transmission device; the first coupling capacitor 6 is connected to the cable shielding layer, and is also connected to the grounded wave-blocking inductor 8.

[0069] In this embodiment, the coupling circuit at the cross-connection box includes a signal amplification circuit, a carrier center frequency filtering and matching circuit, a protection circuit and a second coupling capacitor 7 connected in sequence; the signal amplification circuit is connected to the transmitting end / receiving end of the power line data transmission device; the second coupling capacitor 7 is connected to the cable shielding layer.

[0070] The principle of this embodiment is to adopt a composite coupling technology, use a coupling capacitor to couple a signal to a power line or receive a carrier signal from a power line, and at the same time achieve electrical isolation of strong and weak electricity through a transformer.

[0071] In this embodiment, the signal amplifying circuit uses an amplifier 1, and the amplifier 1 is connected to the transmitting end / receiving end.

[0072] In this embodiment, the carrier center frequency filtering and matching circuit includes a connected transformer 2 and a bandpass filter; wherein the bandpass filter includes a capacitor 4 and an inductor 3 connected in series and a capacitor 4 and an inductor 3 connected in parallel, thereby ensuring the frequency matching of the carrier signal and the filtering of the interference signal, further improving the accuracy and stability of the communication.

[0073] In this embodiment, the protection circuit uses a transient voltage suppression diode, which effectively prevents the voltage shock under the high voltage environment from damaging the device and ensures the safe operation of the device.

[0074] This embodiment provides a carrier communication coupling device for a 110kV high voltage power cable, and the working principle is as follows:

[0075] The carrier signal sent by the transmitting end is transmitted to the cable shielding layer through the signal amplification circuit, the carrier center frequency filtering and matching circuit, the protection circuit and the coupling capacitor in sequence;

[0076] The carrier signal of the cable shielding layer is transmitted to the receiving end through the coupling capacitor, the protection circuit, the carrier center frequency filtering and matching circuit and the signal amplification circuit in sequence.

[0077] Example 2

[0078] This embodiment provides another carrier communication coupling device for 110kV high voltage power cable, which is further optimized and improved on the basis of embodiment 1, as follows:

[0079] like Figure 2 and Figure 7 As shown, in order to make the communication mode more diverse and adapt to different communication needs, this embodiment sets two modes, namely, a phase-to-ground coupling mode and a phase-to-phase coupling mode, and corresponding carrier communication coupling device structures in the two modes, wherein the coupling circuit at the direct grounding box includes a phase-to-ground direct grounding box coupling circuit and a phase-to-phase direct grounding box coupling circuit; the coupling circuit at the cross-connection box includes a phase-to-ground cross-connection box coupling circuit and a phase-to-phase cross-connection box coupling circuit.

[0080] In this embodiment, the carrier communication coupling device includes an amplifier 1, a transformer 2, a protection circuit, a capacitor 4, an inductor 3, a coupling capacitor and a wave-blocking inductor 8 connected in sequence, wherein:

[0081] In this embodiment, the amplifier 1 is used to amplify the modulated signal to increase the signal strength sent to the line, thereby increasing the signal-to-noise ratio of the receiver and improving the stability of communication.

[0082] In this embodiment, the carrier center frequency filtering and matching circuit is mainly composed of a transformer 2 and a bandpass filter.

[0083] The bandpass filter includes L-type, T-type and π-type, 3rd-order, 5th-order and 7th-order LC matching circuits; in this embodiment, a group of capacitors 4 and inductors 3 connected in series and a group of capacitors 4 and inductors 3 connected in parallel are used to form an L-type bandpass filter; the function is to allow the carrier signal of a certain frequency band to pass smoothly, perform impedance matching on the frequency band, filter out signals and noise of other frequencies, improve coupling efficiency, and reduce the influence of wave refraction and reflection on the signal.

[0084] The transformer 2 realizes impedance matching between the primary winding and the secondary winding, and the load obtains the maximum available power by adjusting the transformation ratio of the transformer 2.

[0085] In this embodiment, the protection circuit is mainly a transient voltage suppression diode 5, which is used to protect the safe operation of the device under high voltage conditions.

[0086] In this embodiment, the coupling capacitor has a large impedance to low-frequency signals and a small impedance to high-frequency signals, and can isolate the influence of power frequency voltage, operating overvoltage and lightning overvoltage on the equipment.

[0087] In this embodiment, the coupling circuit at the direct grounding box is slightly different from the coupling circuit at the cross-connection box. The direct grounding box has a wave-blocking inductor to ground the power frequency current, while the cross-connection box does not.

[0088] In this embodiment, the signal source side is the Thevenin equivalent voltage source and internal resistance of the power amplifier circuit, and the internal resistance may include a protective resistor connected in series to limit the maximum output current of the power amplifier. Generally speaking, the equivalent internal resistance is a resistor with a fixed value.

[0089] In this embodiment, the coupling modes include phase-to-ground coupling and phase-to-phase coupling. Phase-to-ground coupling couples the carrier signal to a phase line of the three-phase power line, and only one coupling device is used in a set of carrier devices. Phase-to-phase coupling couples the carrier signal to two phase lines of the three-phase power line, and there are two coupling devices in a set of carrier communication devices.

[0090] like Figures 2 to 6As shown, the direct grounding box includes a power line data transmission device and a coupling circuit at the phase-to-ground direct grounding box; the corresponding cross-connection box includes a power line data transmission device and a coupling circuit at the phase-to-ground cross-connection box; the coupling circuit at the phase-to-ground direct grounding box includes a first coupling capacitor 6, and the first coupling capacitor 6 is connected to the cable shielding layer of one phase (phase A, phase B or phase C); the coupling circuit at the phase-to-ground cross-connection box includes a second coupling capacitor 7, and the second coupling capacitor 7 is connected to the cable shielding layer of one phase (phase A, phase B or phase C).

[0091] like Figures 7 to 11 As shown, the direct grounding box includes a power line data transmission device and a coupling circuit at the phase-to-phase direct grounding box; the corresponding cross-interconnection box includes a power line data transmission device and a coupling circuit at the phase-to-phase cross-interconnection box; the coupling circuit at the phase-to-phase direct grounding box includes two first coupling capacitors 6, one side of the two first coupling capacitors 6 is respectively connected to the protection circuit, the other side of one first coupling capacitor 6 is connected to the cable shielding layer of one phase (for example, phase A) among the three phases, and the other side of the other first coupling capacitor 6 is connected to the cable shielding layer of another phase (for example, phase B) among the three phases.

[0092] In summary, the present invention provides a carrier communication coupling device for a 110kV high-voltage power cable, which has the following advantages:

[0093] First, this carrier communication coupling device realizes stable communication under high-voltage environment by setting up coupling circuits at the direct grounding box and coupling circuits at the cross-connection box, effectively ensuring the continuity and safety of power transmission; secondly, the use of signal amplification circuits greatly enhances the transmission capacity of carrier signals and ensures the clarity and accuracy of signals in long-distance transmission; the configuration of carrier center frequency filtering and matching circuits can accurately match impedance and effectively filter out interference signals and noise, thereby improving communication quality. Finally, the design of the protection circuit not only ensures the safe operation of the carrier communication coupling device under high-voltage conditions, but also extends the service life of the equipment and reduces maintenance costs. This device not only improves the communication performance of high-voltage power cables, but also provides a strong guarantee for the stable operation of the power system.

[0094] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A carrier communication coupling device for 110kV high voltage power cable, characterized in that: It includes a coupling circuit at a direct grounding box and a coupling circuit at a cross-connection box; The coupling circuit at the direct grounding box includes a signal amplifying circuit connected to the transmitting end / receiving end; the signal amplifying circuit is sequentially connected to a carrier center frequency filtering and matching circuit, a protection circuit and a first coupling capacitor (6); the first coupling capacitor (6) is connected to a cable shielding layer and is also connected to a grounded wave-blocking inductor (8); The coupling circuit at the cross-connection box includes a signal amplifying circuit connected to the transmitting end / receiving end; the signal amplifying circuit is sequentially connected to a carrier center frequency filtering and matching circuit, a protection circuit and a second coupling capacitor (7), and the second coupling capacitor (7) is connected to the cable shielding layer; The signal amplification circuit is used to amplify the carrier signal; The carrier center frequency filtering and matching circuit is used for matching impedance and filtering out interference signals and noise; The protection circuit is used to protect the safe operation of the carrier communication coupling device under high voltage conditions.

2. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: The direct grounding box coupling circuit includes a phase-to-ground direct grounding box coupling circuit and an inter-phase direct grounding box coupling circuit; The first coupling capacitor (6) of the coupling circuit at the phase-to-ground direct grounding box is connected to the cable shielding layer of one of the phases; The first coupling capacitor (6) of the coupling circuit at the phase-to-phase direct grounding box is respectively connected to the cable shielding layers of two phases.

3. A carrier communication coupling device for a 110kV high voltage power cable according to claim 2, characterized in that: The coupling circuit at the phase-to-ground direct grounding box includes a first coupling capacitor (6), and the first coupling capacitor (6) is connected to the cable shielding layer of one phase; The coupling circuit of the phase-to-phase direct grounding box comprises two first coupling capacitors (6), one side of the two first coupling capacitors (6) is respectively connected to the protection circuit, the other side of one first coupling capacitor (6) is connected to the shielding layer of a cable of one phase among the three phases, and the other side of the other first coupling capacitor (6) is connected to the shielding layer of the cable of another phase among the three phases.

4. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: The coupling circuit at the cross-connection box includes a coupling circuit at the phase-to-ground cross-connection box and a coupling circuit at the phase-to-phase cross-connection box; The second coupling capacitor (7) of the coupling circuit at the phase-to-ground cross-connection box is connected to the cable shielding layer of one of the phases; The second coupling capacitor (7) of the coupling circuit at the phase-to-phase cross-connection box is respectively connected to the cable shielding layers of two phases.

5. A carrier communication coupling device for a 110kV high voltage power cable according to claim 4, characterized in that: The coupling circuit at the phase-to-ground cross-connection box includes a second coupling capacitor (7), and the second coupling capacitor (7) is connected to the cable shielding layer of one phase; The coupling circuit at the phase-to-phase cross-connection box includes two second coupling capacitors (7), one side of the two second coupling capacitors (7) is respectively connected to the protection circuit, the other side of one second coupling capacitor (7) is connected to the shielding layer of a cable of one phase among the three phases, and the other side of the other second coupling capacitor (7) is connected to the shielding layer of the cable of another phase among the three phases.

6. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: The signal amplification circuit comprises an amplifier (1), and the amplifier (1) is connected to a transmitting end / receiving end.

7. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: The carrier center frequency filtering and matching circuit comprises a connected transformer (2) and a bandpass filter; The bandpass filter comprises a capacitor (4) and an inductor (3) connected in series and a capacitor (4) and an inductor (3) connected in parallel; One side of the transformer (2) is connected to the signal amplifying circuit, and the other side is connected to a capacitor (4) and an inductor (3) connected in series or to a capacitor (4) and an inductor (3) connected in parallel.

8. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: The protection circuit comprises a transient voltage suppression diode (5), one end of which is connected to the carrier center frequency filtering and matching circuit, and the other end of which is grounded.

9. A carrier communication coupling device for a 110kV high voltage power cable according to claim 1, characterized in that: in, The transmitting end adopts the Thevenin equivalent voltage source and equivalent internal resistance of the power amplifier circuit; the internal resistance adopts a fixed value protection resistor to limit the maximum output current of the power amplifier.

10. A working method of a carrier communication coupling device for a 110kV high voltage power cable, based on the carrier communication coupling device according to any one of claims 1 to 9, characterized in that: include: The carrier signal sent by the transmitting end is transmitted to the cable shielding layer through the signal amplification circuit, the carrier center frequency filtering and matching circuit, the protection circuit and the coupling capacitor in sequence; The carrier signal of the cable shielding layer is transmitted to the receiving end through the coupling capacitor, the protection circuit, the carrier center frequency filtering and matching circuit and the signal amplification circuit in sequence.

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