A voltage sensor of the divider bushing type

Abstract

The application belongs to the technical field of voltage sensors, and discloses a voltage sensor of a bushing type of a voltage divider, which comprises a live display inductive capacitor network, a secondary signal acquisition inductive capacitor network, a PCB board capable of adjusting and correcting errors, and a redundant backup capacitor network. The live display inductive capacitor network is used for inducting a high-voltage conductor and acquiring signals, and the secondary signal acquisition inductive capacitor network is used for inducting the high-voltage conductor and acquiring signals. In the application, the coaxial capacitor voltage division technology is used to induct high voltage by the live display and the secondary signal acquisition inductive capacitor network, and the capacitance value is adjusted and corrected by the PCB board, so that the problems of a small dynamic range and uncorrectable errors of a traditional mutual inductor are solved, the double-layer shielding network is resistant to interference, the signal stability is improved, the redundant backup capacitor network and the self-diagnosis module are used to monitor the capacitance value and the dielectric loss in real time, the aging of the capacitor is avoided to prevent the measurement from being inaccurate, the structure is small in size, light in weight, simple in insulation, and suitable for narrow spaces, and the application meets the demand of an intelligent power distribution system.

Description

Technical Field

[0001] This invention relates to the field of voltage sensors, and more specifically, to a voltage divider bushing type voltage sensor. Background Technology

[0002] With the rapid development of information technology, power distribution systems such as substations and new energy power plants are constantly moving towards intelligence. In this process, the importance of power transformers, as the "eyes" of the power system, is self-evident. They undertake key tasks such as energy metering and relay protection in the power system, and their measurement accuracy and reliability are directly related to the safety and economy of the power system.

[0003] However, traditional electromagnetic power transformers still have shortcomings when facing the trend of large-capacity and ultra-high-voltage power distribution systems. On the one hand, their dynamic measurement range is small and they are susceptible to electromagnetic interference, which not only reduces the safety and reliability of power distribution system operation but also makes it difficult to meet the intelligent functions required for power distribution automation management, such as line loss analysis, data acquisition, load monitoring, and fault location. On the other hand, they lack effective fault early warning capabilities, and when problems such as capacitor bank aging occur, they cannot be detected in time, leading to inaccurate metering and affecting the normal operation of the power system. In addition, traditional electromagnetic voltage transformers also have the problem of not being able to correct errors online, which makes it difficult to effectively guarantee their measurement accuracy during long-term use. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a voltage divider bushing-type voltage sensor. Through coaxial capacitor voltage divider technology, a high voltage is sensed by a live display and a secondary signal acquisition sensing capacitor network. Accuracy is corrected by adjusting the capacitance value on the PCB board. This solves the problems of small dynamic range and uncorrectable errors in traditional current transformers. A double-layer shielding network resists interference and improves signal stability. A redundant backup capacitor network and a self-diagnostic module monitor capacitance and dielectric loss in real time. Automatic switching occurs when thresholds are exceeded, providing fault warnings and preventing measurement inaccuracies due to capacitor aging. Structurally, it is small in size, lightweight, and has simple insulation, making it suitable for confined spaces and meeting the needs of intelligent power distribution systems.

[0005] A voltage divider bushing type voltage sensor includes a charged display sensing capacitor grid, a secondary signal acquisition sensing capacitor grid, an adjustable accuracy error PCB board, and a redundant backup capacitor grid.

[0006] The charged display sensing capacitor grid is used to sense high-voltage conductors and collect signals.

[0007] The secondary signal acquisition inductive capacitor network is used to sense the high-voltage conductor and acquire signals.

[0008] The redundant backup capacitor network and the secondary signal acquisition induction capacitor network are connected coaxially in parallel.

[0009] An adjustable precision error PCB board is used to adjust the capacitance value of the capacitor network. The PCB board integrates a self-diagnostic module to monitor the capacitor network parameters in real time and control the redundancy switching.

[0010] Preferably, the charged display sensing capacitor network includes a coaxial sensing capacitor network, a first signal acquisition terminal, and a fixed terminal, and the signal is transmitted to the charged display via the first signal acquisition terminal.

[0011] Preferably, the secondary signal acquisition sensing capacitor network includes a coaxial sensing capacitor network, a second signal acquisition terminal, and a connecting pin; the redundant backup capacitor network includes a backup sensing capacitor network, a backup network signal acquisition terminal, and a backup network connecting pin; and the second signal acquisition terminal and the backup network signal acquisition terminal are arranged coaxially and equidistantly.

[0012] Preferably, the PCB board is connected to the second signal acquisition terminal via connecting pins, and the accuracy error is corrected by adjusting the total capacitance value of the secondary signal acquisition sensing capacitor network. The connecting pins and the backup network connecting pins are vertically inserted into the symmetrical pads of the PCB board.

[0013] Preferably, the voltage divider bushing type voltage sensor also includes a shielding mesh to prevent primary interference signals, which covers the outside of the entire capacitor mesh and is used to shield the primary conductor from interference signals.

[0014] Preferably, the voltage divider bushing type voltage sensor further includes product mounting terminals and a product insulation layer, wherein the product mounting terminals are used to fix the sensor, and the product insulation layer covers the outside of the shielding mesh.

[0015] Preferably, the self-diagnostic module monitors the capacitance change rate ΔC / C and dielectric loss angle of the secondary signal acquisition inductive capacitor network. When △C / C>1% or >0.005, automatically switch to redundant backup capacitor network.

[0016] Preferably, the self-diagnostic module performs capacitance and dielectric loss monitoring with a period of 10ms, and the self-diagnostic module executes the following algorithm with a period of 10ms:

[0017] S1: Acquisition Capacity C t and ;

[0018] S2: Calculate △C / C=|C t -C 基准 | / C 基准 ×100%;

[0019] S3: If △C / C>1% or If the value is >0.005, output the fault code and activate the redundancy switch.

[0020] Preferably, the shielding mesh is a double-layer copper wire braided structure, with an inner layer aperture ≤0.5 mm and an outer layer covered with a polytetrafluoroethylene insulating coating.

[0021] Preferably, the PCB board integrates a temperature compensation circuit, including:

[0022] Thermistor mounted on the capacitor network;

[0023] Reference voltage source;

[0024] Compensation network composed of operational amplifiers;

[0025] The compensation network collects temperature signals in real time, calculates the compensation value using the following formula, and corrects the output signal:

[0026] .

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The capacitor voltage divider sensing method has low power consumption, simple structure, no open circuit risk, and is safe and reliable; the double-layer structure of the shielding mesh can effectively isolate electromagnetic interference, reduce signal transmission errors, and solve the problems of small dynamic range and susceptibility to interference of traditional instrument transformers; the self-diagnostic module monitors the capacitor network parameters in real time and automatically switches to the redundant backup capacitor network to avoid metering inaccuracies caused by capacitor aging, filling the gap of traditional instrument transformers' lack of fault early warning capability and meeting the fault location requirements of power distribution automation.

[0029] 2. The PCB board achieves accuracy correction by adjusting the capacitance value of the secondary signal acquisition induction capacitor network. Compared with the defect of traditional instrument transformers where the error cannot be adjusted after leaving the factory, it can maintain high-precision measurement during long-term use, ensuring the reliability of data such as line loss analysis and load monitoring. In addition, the size and weight are reduced compared with traditional instrument transformers, and the insulation structure is simple, which can reduce manufacturing costs and solve the problems of large size, high cost and complex installation of traditional instrument transformers, thus adapting to the highly integrated needs of smart grids. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2This is a partial structural diagram of the present invention;

[0033] Figure 3 This is a flowchart of the present invention.

[0034] Explanation of the labels in the diagram:

[0035] 1. High-voltage conductor;

[0036] 2. Capacitor grid for live display; 201. Fixed terminal; 202. First signal acquisition terminal;

[0037] 3. Secondary signal acquisition sensing capacitor grid; 301. Second signal acquisition terminal; 302. Connecting pin;

[0038] 4. Shielding mesh;

[0039] 5. PCB board;

[0040] 6. Product mounting terminals;

[0041] 7. Product insulation layer;

[0042] 8. Redundant backup capacitor network; 801. Backup network signal acquisition terminal; 802. Backup network connection pin. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] like Figure 1 , Figure 2 and Figure 3 As shown, a voltage divider bushing type voltage sensor includes a charged display sensing capacitor network 2, a secondary signal acquisition sensing capacitor network 3, an adjustable accuracy error PCB board 5, and a redundant backup capacitor network 8.

[0045] The live display sensing capacitor network 2 is used to sense the high-voltage conductor 1 and collect signals; the secondary signal acquisition sensing capacitor network 3 is used to sense the high-voltage conductor 1 and collect signals; the redundant backup capacitor network 8 is coaxially connected in parallel with the secondary signal acquisition sensing capacitor network 3.

[0046] The spatial electric field of the high-voltage conductor 1 is directly coupled through the coaxially arranged charged display induction capacitor network 2 and secondary signal acquisition induction capacitor network 3, eliminating the need for ferromagnetic materials and complex insulation structures, and making it suitable for narrow installation spaces, such as GIS cabinets.

[0047] The adjustable precision error PCB board 5 is used to adjust the capacitance value of the capacitor network. The PCB board 5 integrates a self-diagnostic module to monitor the capacitor network parameters in real time and control the redundancy switching.

[0048] The circuit integrates signal processing circuitry on the PCB board to convert pF-level capacitor signals into mA-level analog outputs. The power consumption is lower than that of traditional electromagnetic transformers, and it can be directly connected to the data acquisition unit of intelligent power distribution systems.

[0049] pF (picofarad) is the unit of capacitance;

[0050] mA (milliampere) is a unit of electric current;

[0051] High-voltage energized status monitoring is achieved through the live display sensing capacitor network 2, the secondary signal acquisition sensing capacitor network 3 meets the high-precision metering requirements, the redundant backup capacitor network 8 improves system reliability, and the self-diagnostic module of PCB board 5 realizes fault warning and automatic switching, solving the problems of small dynamic range, no fault warning and inability to correct errors online in traditional current transformers.

[0052] The self-diagnostic module monitors the capacitor network parameters in real time. When ΔC / C > 1% or When the value is greater than 0.005, the redundant capacitor network is automatically switched to avoid metering inaccuracies caused by capacitor aging, thus meeting the needs of power distribution automation for line loss analysis and fault location.

[0053] : The tangent of the dielectric loss angle;

[0054] △C: Absolute value of real-time capacitance deviation;

[0055] C: Nominal capacitance (100pF);

[0056] △C / C: Capacity change rate.

[0057] The live display sensing capacitor network 2 includes a coaxial sensing capacitor network, a first signal acquisition terminal 202 and a fixed terminal 201. The signal is transmitted to the live display via the first signal acquisition terminal 202.

[0058] The structured design of the coaxial induction capacitor network, the first signal acquisition terminal 202, and the fixed terminal 201 of the live display induction capacitor network 2 ensures coaxial installation with the high voltage conductor 1, guarantees the stability and consistency of the induction signal, and solves the measurement deviation problem caused by the installation error of traditional current transformers.

[0059] The secondary signal acquisition sensing capacitor network 3 includes a coaxial sensing capacitor network, a second signal acquisition terminal 301, and a connecting pin 302. The redundant backup capacitor network 8 includes a backup sensing capacitor network, a backup network signal acquisition terminal 801, and a backup network connecting pin 802. The second signal acquisition terminal 301 and the backup network signal acquisition terminal 801 are arranged coaxially and equidistantly.

[0060] The secondary signal acquisition inductive capacitor grid 3 uses electrolytic copper mesh with a purity of ≥99.99%, conforming to GB / T 5231-2012, reducing the resistivity to 1.68×10⁻⁶. -8 Ω·m, reducing signal transmission loss;

[0061] The backup network connection pins are plated with 802 gold with a thickness of ≥3μm according to ISO 4524-1 standard, ensuring a contact resistance of <5mΩ in an environment with humidity >85% to prevent signal attenuation caused by oxidation.

[0062] The second signal acquisition terminal 301 has a length of 20 mm ± 0.1 mm.

[0063] The redundant backup capacitor network 8 and the secondary signal acquisition sensing capacitor network 3 are symmetrically distributed at 180°.

[0064] The connecting pin 302 and the backup network connecting pin 802 are inserted into the symmetrical pads of the PCB board 5 at a 90° vertical angle with a spacing of 2.54mm. The pads are pre-filled with Sn96.5Ag3Cu0.5 lead-free solder paste that conforms to the J-STD-006 standard. This vertical symmetrical insertion design reduces the signal path length to less than 15mm, which shortens the axial dimension of the sensor compared to traditional current transformers, making it suitable for the narrow space of GIS cabinets.

[0065] The coaxial and equidistant arrangement of the secondary signal acquisition induction capacitor network 3 and the redundant backup capacitor network 8 ensures that the induced electric field strength of the two is consistent, and there is no signal jump during switching, which improves the continuous operation capability of the system and solves the problem that the aging of the single capacitor network of the traditional current transformer cannot be detected in time.

[0066] PCB board 5 is connected to the second signal acquisition terminal 301 via connecting pin 302. The accuracy error is corrected by adjusting the total capacitance value of the secondary signal acquisition sensing capacitor network 3. Connecting pin 302 and backup network connecting pin 802 are vertically inserted into the symmetrical pads of PCB board 5.

[0067] By eliminating the iron core and oil-immersed insulation and adopting a vertical pin design, the axial dimension of the sensor can be shortened, the weight reduced, and manufacturing costs and installation and maintenance difficulties lowered.

[0068] The PCB board 5 is connected to the second signal acquisition terminal 301 via the connecting pin 302 to realize online capacitance adjustment. Compared with the fixed error design of traditional current transformers, it can adapt to the accuracy requirements under different working conditions. The connecting pin 302 and the backup network connecting pin 802 are vertically and symmetrically soldered, which can optimize the circuit layout and reduce signal interference.

[0069] The voltage divider bushing type voltage sensor also includes a shielding mesh 4 to prevent primary interference signals, which covers the outside of the entire capacitor mesh and is used to shield the primary conductor from interference signals.

[0070] The inner layer of the shielding mesh 4 is made of phosphor bronze woven mesh with a mesh size of 0.5mm; the outer layer is coated with polytetrafluoroethylene with a thickness of 50μm.

[0071] The double-layer copper wire braided shielding mesh has a fine inner pore size that effectively shields high-frequency interference, while the outer polytetrafluoroethylene insulating coating prevents leakage. Compared with the single shielding structure of traditional instrument transformers, it improves anti-interference capability and solves the problem of traditional instrument transformers being susceptible to electromagnetic interference.

[0072] The voltage divider bushing type voltage sensor also includes a product mounting terminal 6 and a product insulation layer 7. The product mounting terminal 6 is used to fix the sensor, and the product insulation layer 7 covers the outside of the shielding mesh 4.

[0073] The insulation layer 7 of the product is made of silicone rubber with a Shore hardness of 60A.

[0074] The product's mounting terminal 6 supports multiple installation methods, adapting to confined spaces such as GIS cabinets and new energy grid connection points; the product's insulation layer 7 uses high voltage-resistant materials to ensure insulation reliability under high voltage environments, solving the problems of large size and complex installation of traditional instrument transformers.

[0075] The self-diagnostic module monitors the capacitance change rate ΔC / C and dielectric loss angle of the secondary signal acquisition inductive capacitor network 3. When △C / C>1% or When the value is greater than 0.005, the system automatically switches to the redundant backup capacitor network 8.

[0076] The self-diagnostic module monitors capacitance and dielectric loss using high-frequency sampling at 10ms, and sets ΔC / C>1% or A threshold of >0.005 allows for earlier detection of potential capacitor network aging issues compared to manual inspections, reducing fault warning time from hours to milliseconds.

[0077] The self-diagnostic module performs capacitance and dielectric loss monitoring every 10ms. The self-diagnostic module executes the following algorithm every 10ms:

[0078] S1: Acquisition Capacity C t and Specifically, through the 24-bit interface on PCB board 5. The ADS124S08 ADC is used to acquire the voltage V across the capacitor grid. c And the phase difference θ, according to the formula:

[0079] Calculate the dielectric loss angle, where ω = 2πff = 50Hz power frequency;

[0080] S2: Calculation =|C t -C 基准 | / C 基准 ×100%;

[0081] S3: △C / C>1% or If the value is >0.005, output the fault code and activate the redundancy switch.

[0082] The well-defined self-diagnostic algorithm process S1-S3 ensures the accuracy and consistency of fault diagnosis and avoids human error; the 10ms periodic sampling meets the real-time monitoring requirements and adapts to the real-time status monitoring requirements of smart distribution networks.

[0083] In the above formula: ω: angular frequency; C: capacitance value; G: conductance; Vc: voltage across the capacitor grid; θ: phase difference between voltage and current; Is: standard injection current.

[0084] The shielding mesh 4 has a double-layer copper wire braided structure, with an inner layer aperture of ≤0.5 mm and an outer layer covered with a polytetrafluoroethylene insulating coating.

[0085] The combination of a double-layer copper wire braided structure and a polytetrafluoroethylene coating enables the shielding effectiveness of shielding mesh 4 to be ≥80dB in the 100MHz-1GHz frequency band. According to GB / T 12190-2021 "Measurement Method of Shielding Effectiveness of Electromagnetic Shielding Room", a 100W interference signal was injected into an anechoic chamber, and the measured shielding effectiveness in the 100MHz-1GHz frequency band was ≥82dB. This can improve the shielding effectiveness of shielding mesh 4 and effectively suppress the influence of electromagnetic interference from the primary conductor on the secondary signal.

[0086] PCB board 5 integrates a temperature compensation circuit, including:

[0087] Thermistor RT1 is mounted on the capacitor grid;

[0088] Reference voltage source U2;

[0089] The compensation network is composed of operational amplifier U3;

[0090] The compensation network collects temperature signals in real time, calculates the compensation value using the following formula, and corrects the output signal:

[0091] .

[0092] V_out': Output voltage after compensation;

[0093] V_out: Original output voltage;

[0094] Temperature coefficient of copper mesh (-5×10) -5 / ℃);

[0095] T: Real-time temperature (°C);

[0096] T_ref: Standard ambient temperature (25℃);

[0097] In the compensation formula: α = -5 × 10 -5 The temperature coefficient of the copper mesh at / ℃ was determined according to GB / T 351-2019 "Metallic Materials - Test Method for Resistivity". IEC60068-2-1 standard ambient temperature.

[0098] The thermistor RT1, model number NT C3950K, is mounted on the capacitor grid and is placed in the projection area of ​​the capacitor grid.

[0099] Operational amplifier U3, model number OPA2188, has a gain and bandwidth of 10MHz;

[0100] Compensation execution: When T=85℃, → .

[0101] The temperature compensation circuit senses temperature changes in real time through thermistor RT1 and dynamically corrects the output signal according to the formula. Within the temperature range of -40℃ to 85℃, the accuracy drift is ≤ ±0.2%, solving the measurement error problem caused by temperature drift of traditional current transformers.

[0102] Verification of temperature compensation effect: At a high temperature of 85℃, the error without compensation reaches +0.82%, and the capacitance value drift of the secondary signal acquisition sensing capacitor network 3 is ΔC / C=0.95%. Before triggering the switching threshold, the compensation circuit outputs V_out'=0.997V_out, suppressing the error to +0.07%, which is lower than the 0.5% required by IEC61869-1 Class 0.5.

[0103] Self-diagnosis algorithm steps:

[0104] S0, Initialize the baseline value;

[0105] Upon power-up, the reference capacitance value C (nominal value 100pF, accuracy ±0.1%) and dielectric loss angle threshold are read from the EEPROM. =0.005;

[0106] S1, signal acquisition period 10ms;

[0107] Through 24 bits ADC model ADS124S08 acquisition:

[0108] Real-time capacitance voltage across capacitor network Conversion formula:

[0109] Dielectric loss angle Phase difference θ calculation formula: = ,in .

[0110] S2, Calculation of rate of change;

[0111] Calculate the relative rate of change of capacitance: ;

[0112] S3, Threshold Judgment and Execution;

[0113] Condition 1: If :

[0114] Output fault codes:

[0115] Exceeding limits → Code C1;

[0116] Exceeding limits → Code C2;

[0117] Send a high-level signal of 3.3V to the GPIO port to trigger the MOSFET switching circuit;

[0118] After the switch is completed, output status code C3 (UART transmission to secondary device).

[0119] Condition 2: If not exceeded → perform PCB accuracy correction, return to step S1

[0120] S4. After the switch is completed, the parameters of the backup capacitor network will be continuously monitored using the same algorithm.

[0121] In the above formula: Ct: real-time capacitance (pF); f: power frequency (Hz); Vc: voltage across the capacitor network (V); Rs: equivalent series resistance (Ω); Is: standard injection current (mA); θ: phase difference between voltage and current (radians); ω: angular frequency (rad / s).

[0122] The live display sensing capacitor network 2 senses the change in electric field of the high-voltage conductor 1 through the coaxial sensing capacitor network, and transmits it to the live display through the first signal acquisition terminal 202 to realize the high-voltage live status indication; the secondary signal acquisition sensing capacitor network 3 synchronously senses the high-voltage signal and transmits it to the PCB board 5 with adjustable accuracy error through the second signal acquisition terminal 301.

[0123] The PCB board 5 is connected to the secondary signal circuit through the connector pin 302. By adjusting the total capacitance of the secondary signal acquisition sensing capacitor network 3, such as by parallel or series capacitors, manufacturing errors and environmental influences are compensated to ensure that the output signal meets the standard accuracy requirements.

[0124] The shielding mesh 4 for preventing primary interference signals adopts a double-layer copper wire braided structure with an inner layer aperture of ≤0.5mm and an outer layer covered with a polytetrafluoroethylene insulating coating, effectively shielding the electromagnetic interference of the primary conductor and ensuring signal transmission stability.

[0125] Redundant backup capacitor network 8 is coaxially connected in parallel with secondary signal acquisition sensing capacitor network 3. The self-diagnostic module monitors the capacitance change rate ΔC / C and dielectric loss angle with a period of 10ms. When △C / C>1% or When the value is greater than 0.005, the system automatically switches to the redundant backup capacitor network 8 to avoid measurement inaccuracies caused by capacitor network aging.

[0126] The PCB board 5 integrates a temperature compensation circuit. The temperature signal is collected in real time by the thermistor RT1 mounted on the capacitor network. The compensation value is calculated by the compensation network composed of the reference voltage source U2 and the operational amplifier U3 according to the formula V_out'=V_out×[1+α(T-T_ref)] to correct the accuracy drift caused by temperature.

[0127] Application scenario: Monitoring of 35kV grid-connected cabinets in photovoltaic power plants;

[0128] The sensor is fixed to the confined space of the GIS cabinet via product mounting terminal 6, which shortens the axial dimension and reduces the weight.

[0129] The electric field of the high-voltage conductor 1 is synchronously coupled to the energized display induction capacitor network 2 and the secondary signal acquisition induction capacitor network 3, and output to the energized display (high voltage indicator) and PCB board 5 (metering signal), respectively.

[0130] Double-layer shielding mesh 4 suppresses inverter harmonic interference.

[0131] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A voltage divider bushing type voltage sensor, characterized by, It comprises: a live display induction capacitor network (2) for sensing a high-voltage conductor (1) and collecting signals; a secondary signal collection induction capacitor network (3) for sensing the high-voltage conductor (1) and collecting signals; a redundant backup capacitor network (8) coaxially connected in parallel with the secondary signal collection induction capacitor network (3); a PCB board (5) for adjusting the error of precision, which is used for adjusting the capacitance value of the capacitor network; the PCB board (5) integrates a self-diagnosis module, which monitors the parameters of the capacitor network in real time and controls the redundancy switching; The self-diagnosis module monitors the change rate of the capacitance value of the secondary signal acquisition induction capacitance network (3) and the dielectric loss angle When ΔC / C>1% or >0.005, automatically switch to the redundant backup capacitance network (8) the PCB board (5) integrates a temperature compensation circuit, which comprises: a thermistor (RT1) attached to the capacitor network; a reference voltage source (U2); a compensation network composed of an operational amplifier (U3); the compensation network collects temperature signals in real time, calculates the compensation value by the following formula, and corrects the output signal: ； V_out': compensated output voltage; V_out: original output voltage; : copper mesh temperature coefficient (-5 x 10 -5 / °C); T: real-time temperature (℃); T_ref: standard ambient temperature (25℃); In the compensation formula: α = -5 × 10 -5 Temperature coefficient of copper mesh, determined by GB / T 351-2019 "Metal Material Resistance Coefficient Test Method"; IEC60068-2-1 standard ambient temperature.

2. The voltage divider bushing type voltage sensor of claim 1, wherein: the live display induction capacitor network (2) comprises a coaxial induction capacitor network, a first signal collection terminal (202), and a fixed terminal (201), and the signal is transmitted to the live display through the first signal collection terminal (202).

3. The voltage divider bushing type voltage sensor of claim 1, wherein: The secondary signal collection induction capacitor network (3) comprises a coaxial induction capacitor network, a second signal collection terminal (301), and a connection pin (302), and the redundant backup capacitor network (8) comprises a backup induction capacitor network, a backup network signal collection terminal (801), and a backup network connection pin (802). The second signal collection terminal (301) and the backup network signal collection terminal (801) are coaxially and equidistantly arranged.

4. The voltage divider bushing type voltage sensor of claim 1, wherein: The PCB board (5) is connected to the second signal collection terminal (301) through the connection pin (302), and the precision error is corrected by adjusting the total capacitance value of the secondary signal collection induction capacitor network (3). The connection pin (302) and the backup network connection pin (802) are vertically inserted into the symmetrical pads of the PCB board (5).

5. The voltage divider bushing type voltage sensor of claim 1, wherein: It also comprises a shielding network (4) for preventing primary interference signals, which is wrapped outside all capacitor networks to shield the interference signals of the primary conductor.

6. The voltage divider bushing type voltage sensor of claim 1, wherein: It also comprises a product mounting terminal (6) and a product insulation layer (7), wherein the product mounting terminal (6) is used to fix the sensor, and the product insulation layer (7) is wrapped outside the shielding network (4).

7. The voltage divider bushing type voltage sensor of claim 1, wherein: The self-diagnosis module performs capacitance value and dielectric loss monitoring with a period of 10ms, and executes the following algorithm with a period of 10ms. S1 : Collecting the capacity value C t and ; S2: Calculate AC / C = |C t -C 基准 | / C 基准 x 100%; S3: If ΔC / C > 1% or > 0.005, output a fault code and activate redundant switching.

8. The voltage divider bushing type voltage sensor of claim 5, wherein: The shielding network (4) is a double-layer copper wire braided structure, and the inner layer aperture is ≤0.5mm, and the outer layer is covered with a polytetrafluoroethylene insulation coating.

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