Voltage-dividing bushing type voltage sensor

Abstract

The invention belongs to the technical field of voltage sensors, and discloses a voltage-dividing bushing type voltage sensor, which comprises an electrified display induction capacitance network, a secondary signal acquisition induction capacitance network, a PCB (Printed Circuit Board) capable of adjusting precision errors and a redundant backup capacitance network, and is characterized in that the electrified display induction capacitance network is used for inducing a high-voltage conductor and acquiring signals; and the secondary signal acquisition induction capacitance net is used for inducing the high-voltage conductor and acquiring signals. According to the invention, through the coaxial capacitance voltage division technology, the electrified display and the secondary signal acquisition induction capacitance net are used for sensing high voltage, the capacitance value correction precision is adjusted through the PCB, the problems of small dynamic range and uncorrectable error of a traditional transformer are solved, the double-layer shielding net is anti-interference, the signal stability is improved, and the reliability of the transformer is improved. The redundant backup capacitor network and the self-diagnosis module monitor capacitance and dielectric loss in real time, measurement misalignment caused by capacitor aging is avoided, the structure is small in size, light in weight, simple in insulation and suitable for narrow space, and the requirements of an intelligent power distribution system are met.

Description

Technical Field

[0001] The present invention relates to the field of voltage sensors, and more particularly to a voltage-dividing bushing-type voltage sensor. Background Art

[0002] With the rapid development of information technology, power distribution systems such as substations and renewable energy power plants are continuously moving towards intelligence. In this process, power transformers, as the "eyes" of the power system, are of undeniable importance. They undertake key tasks in power systems, such as energy metering and relay protection. Their measurement accuracy and reliability are directly related to the safety and economic efficiency of the power system.

[0003] However, traditional electromagnetic power transformers still face shortcomings when facing the development trend of large-capacity and ultra-high voltage distribution systems. On the one hand, they have a small dynamic measurement range and are susceptible to electromagnetic interference. This not only reduces the safety and reliability of distribution system operation, but also makes it difficult to meet the requirements of intelligent functions such as line loss analysis, data collection, load monitoring, and fault location in distribution automation management. On the other hand, they lack effective fault warning capabilities. When problems such as aging of the capacitor network occur, they cannot be detected in time, resulting in inaccurate measurement and affecting the normal operation of the power system. Furthermore, traditional electromagnetic voltage transformers cannot correct errors online, making it difficult to effectively guarantee measurement accuracy during long-term use. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a voltage divider bushing type voltage sensor, which uses coaxial capacitor voltage divider technology to sense high voltage with a live display and a secondary signal acquisition induction capacitor network, and adjusts the capacitance value correction accuracy through a PCB board to solve the problems of small dynamic range and unrepairable error of traditional mutual inductors. The double-layer shielding network is anti-interference and improves signal stability. The redundant backup capacitor network and self-diagnosis module monitor the capacitance value and dielectric loss in real time, and automatically switches when the threshold exceeds the threshold to achieve fault warning and avoid inaccurate measurement caused by capacitor aging. The structure is small in size, light in weight, simple in insulation, and adaptable to small spaces to meet the needs of intelligent power distribution systems.

[0005] A voltage divider bushing type voltage sensor, comprising a charged display induction capacitor network, a secondary signal acquisition induction capacitor network, a PCB board with adjustable accuracy error, and a redundant backup capacitor network; The charged display sensing capacitor network is used to sense the high voltage conductor and collect the signal; The secondary signal acquisition induction capacitor network is used to sense the high voltage conductor and collect signals; The redundant backup capacitor network and the secondary signal acquisition induction capacitor network are coaxially connected in parallel; A PCB board with adjustable precision error is used to adjust the capacitance value of the capacitor network. The PCB board integrates a self-diagnosis module to monitor the parameters of the capacitor network in real time and control redundant switching.

[0006] Preferably, the charged display inductive capacitor network includes a coaxial inductive 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.

[0007] Preferably, the secondary signal acquisition induction capacitor network includes a coaxial induction capacitor network, a second signal acquisition terminal and a connecting pin, and the redundant backup capacitor network includes a backup induction 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 coaxially and equidistantly arranged.

[0008] Preferably, the PCB board is connected to the second signal acquisition terminal through a connecting pin, and the accuracy error is corrected by adjusting the total capacitance of the secondary capacitor network. The connecting pin and the backup network connecting pin are vertically inserted into the symmetrical pads of the PCB board.

[0009] Preferably, the voltage divider bushing type voltage sensor further comprises a shielding net for preventing primary interference signals, which is coated on the outside of all capacitor nets and is used to shield interference signals of the primary conductor.

[0010] Preferably, the voltage divider bushing type voltage sensor further includes a product installation terminal and a product insulation layer, wherein the product installation terminal is used to fix the sensor, and the product insulation layer covers the outside of the shielding net.

[0011] Preferably, the self-diagnosis module monitors the capacitance change rate ΔC / C and dielectric loss angle of the secondary capacitor network. , when △C / C>1% or >0.005, automatically switches to the redundant backup capacitor network.

[0012] Preferably, the self-diagnosis module performs capacitance and dielectric loss monitoring in a 10 ms period, and the self-diagnosis module performs the following algorithm in a 10 ms period: S1: Collect capacitance C t and ; S2: Calculate △C / C=|C t -C 基准 | / C 基准 ×100%; S3: If △C / C>1% or >0.005, output fault code and activate redundancy switching.

[0013] Preferably, the shielding mesh is a double-layer copper wire braided structure, the inner layer aperture is ≤0.5 mm, and the outer layer is covered with a polytetrafluoroethylene insulation coating.

[0014] Preferably, the PCB board integrates a temperature compensation circuit, comprising: Thermistor mounted on the capacitor network; Reference voltage source; Compensation network composed of operational amplifier; The compensation network collects temperature signals in real time, calculates the compensation value and corrects the output signal using the following formula: .

[0015] Compared with the prior art, the present invention has the following beneficial effects: 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 network can effectively isolate electromagnetic interference, reduce signal transmission errors, and solve the problems of small dynamic range and susceptibility to interference of traditional transformers. The self-diagnosis module monitors the parameters of the capacitor network in real time and automatically switches to the redundant backup capacitor network to avoid measurement inaccuracies due to capacitor aging. This fills the gap in the fault warning capability of traditional transformers and meets the needs of distribution automation for fault location.

[0016] 2. The PCB board achieves precision correction by adjusting the capacitance of the secondary capacitor network. Compared with the defect of traditional transformers that cannot adjust the error after leaving the factory, it can maintain high-precision measurement in long-term use, ensuring the reliability of data such as line loss analysis and load monitoring. In addition, the volume and weight are reduced compared to traditional transformers, and the insulation structure is simple, which can reduce manufacturing costs and solve the problems of large volume, high cost and complex installation of traditional transformers, adapting to the highly integrated needs of smart grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the following is a brief introduction to the drawings required for use in the implementation methods. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the local structure of the present invention; Figure 3 Flowchart of the present invention.

[0019] Description of the numbers in the figure: 1. High voltage conductor; 2. Charged display induction capacitor network; 201. Fixed terminal; 202. First signal acquisition terminal; 3. Secondary signal acquisition induction capacitor network; 301. Second signal acquisition terminal; 302. Connection pin; 4. Shielding net; 5. PCB board; 6. Product installation terminals; 7. Product insulation layer; 8. Redundant backup capacitor network; 801. Backup network signal acquisition terminal; 802. Backup network connection pin. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The specific embodiments of the present invention are described in detail below in conjunction with the drawings in the specification.

[0021] like Figure 1 、 Figure 2 and Figure 3 As shown, a voltage divider bushing type voltage sensor includes a charged display induction capacitor network 2, a secondary signal acquisition induction capacitor network 3, a PCB board 5 with adjustable accuracy error, and a redundant backup capacitor network 8; The charged display induction capacitor network 2 is used to sense the high-voltage conductor 1 and collect signals; the secondary signal collection induction 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 collection induction capacitor network 3; The spatial electric field of the high-voltage conductor 1 is directly coupled through the coaxially arranged charged display induction capacitor network 2 and the secondary signal acquisition induction capacitor network 3, eliminating ferromagnetic materials and complex insulation structures, and adapting to small installation spaces such as GIS cabinets.

[0022] The PCB board 5 with adjustable precision error is used to adjust the capacitance value of the capacitor network. The PCB board 5 integrates a self-diagnosis module to monitor the parameters of the capacitor network in real time and control redundancy switching. The PCB board 5 integrates the signal processing circuit to convert the pF-level capacitance signal into the mA-level analog output. The power consumption is lower than that of the traditional electromagnetic transformer and can be directly connected to the data acquisition unit of the intelligent power distribution system.

[0023] pF (picofarad) is the unit of capacitance; mA (milliampere) is the unit of electric current; High-voltage live status monitoring is achieved through the live display inductive capacitor network 2. The secondary signal acquisition inductive capacitor network 3 meets the high-precision measurement requirements. The redundant backup capacitor network 8 improves system reliability. The self-diagnosis module of the PCB board 5 realizes fault warning and automatic switching, solving the problems of traditional mutual inductors with small dynamic range, no fault warning, and inability to correct errors online.

[0024] The self-diagnosis module monitors the capacitance network parameters in real time. When △C / C>1% or When the value is greater than 0.005, the redundant capacitor network is automatically switched to avoid inaccurate measurement due to capacitor aging, meeting the needs of power distribution automation for line loss analysis and fault location.

[0025] : dielectric loss tangent value; △C: Absolute value of real-time capacitance deviation; C: nominal capacitance (100pF); △C / C: Capacitance change rate.

[0026] The charged display inductive capacitor network 2 comprises a coaxial inductive capacitor network, a first signal acquisition terminal 202 and a fixed terminal 201 . The signal is transmitted to the charged display via the first signal acquisition terminal 202 .

[0027] The structural design of the coaxial inductive capacitor network, the first signal acquisition terminal 202 and the fixed terminal 201 of the charged display inductive capacitor network 2 ensures coaxial installation with the high-voltage conductor 1, ensures the stability and consistency of the inductive signal, and solves the measurement deviation problem caused by the installation error of the traditional mutual inductor.

[0028] The secondary signal acquisition induction capacitor network 3 includes a coaxial induction capacitor network, a second signal acquisition terminal 301 and a connecting pin 302. The redundant backup capacitor network 8 includes a backup induction 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 coaxially and equidistantly arranged.

[0029] The secondary signal acquisition induction capacitor network 3 uses an electrolytic copper network with a purity of ≥99.99%, which complies with GB / T 5231-2012 and reduces the resistivity to 1.68×10 -8 Ω·m, reducing signal transmission loss; The backup network connection pin 802 has a gold plating thickness of ≥3μm according to ISO 4524-1 standard, ensuring contact resistance <5mΩ in an environment with humidity >85% to prevent signal attenuation caused by oxidation.

[0030] The second signal collection terminal 301 has a length of 20 mm ± 0.1 mm.

[0031] The redundant backup capacitor network 8 and the secondary signal acquisition sensing capacitor network 3 are symmetrically distributed at 180°.

[0032] 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-set with Sn96.5Ag3Cu0.5 lead-free solder paste in accordance with the J-STD-006 standard. This vertically symmetrical plug-in design reduces the signal path length to less than 15mm, shortening the axial size of the sensor compared to traditional mutual inductors, making it suitable for the narrow space of the GIS cabinet.

[0033] The coaxial and equidistant arrangement design of the secondary signal acquisition induction capacitor network 3 and the redundant backup capacitor network 8 ensures that the induction electric field strength of the two is consistent, and there is no signal jump during switching, which improves the system's continuous operation capability and solves the problem that the aging of the single capacitor network of the traditional mutual inductor cannot be discovered in time.

[0034] The PCB board 5 is connected to the second signal acquisition terminal 301 through the connecting pin 302. The accuracy error is corrected by adjusting the total capacitance of the secondary capacitor network. The connecting pin 302 and the backup network connecting pin 802 are vertically inserted into the symmetrical pads of the PCB board 5.

[0035] By eliminating the iron core and oil-immersed insulation and adopting a vertical pin design, the sensor's axial size can be shortened, its weight reduced, and its manufacturing cost and installation and maintenance difficulty reduced.

[0036] The PCB board 5 is connected to the second signal acquisition terminal 301 through the connecting pin 302 to realize online adjustment of the capacitance value. Compared with the fixed error design of the traditional transformer, 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 welded, which can optimize the circuit layout and reduce signal interference.

[0037] The voltage divider bushing type voltage sensor further comprises a shielding net 4 for preventing primary interference signals, which is coated on the outside of all capacitor nets and is used for shielding interference signals of the primary conductor.

[0038] The inner layer of the shielding mesh 4 is a phosphor bronze braided mesh with a pore size of 0.5 mm; the outer layer is provided with a polytetrafluoroethylene coating with a thickness of 50 μm.

[0039] The double-layer copper wire braided shielding mesh has a fine inner layer with fine apertures to effectively shield high-frequency interference, and the outer layer of polytetrafluoroethylene insulation coating prevents leakage. Compared with the single shielding structure of traditional transformers, it improves anti-interference ability and solves the problem that traditional transformers are susceptible to electromagnetic interference.

[0040] The voltage divider bushing type voltage sensor further includes a product installation terminal 6 and a product insulation layer 7 . The product installation terminal 6 is used to fix the sensor, and the product insulation layer 7 covers the outside of the shielding net 4 .

[0041] The product's insulation layer 7 is cast in silicone rubber with a Shore hardness of 60A.

[0042] The product's installation terminal 6 supports multiple installation methods and is suitable for confined spaces such as GIS cabinets and new energy grid-connected points. The product's insulation layer 7 uses high-voltage-resistant materials to ensure insulation reliability in high-voltage environments, solving the problems of large size and complex installation of traditional transformers.

[0043] The self-diagnosis module monitors the capacitance change rate △C / C and dielectric loss angle of the secondary capacitor network , when △C / C>1% or When >0.005, it automatically switches to the redundant backup capacitor network 8.

[0044] The self-diagnosis module monitors the capacitance and dielectric loss with a high-frequency sampling of 10ms, and sets △C / C>1% or >0.005 is the switching threshold. Compared with manual inspections, it can detect hidden dangers of capacitor network aging in advance and shorten the fault warning time from hours to milliseconds.

[0045] The self-diagnosis module performs capacitance and dielectric loss monitoring in a 10ms cycle. The self-diagnosis module executes the following algorithm in a 10ms cycle: S1: Collect capacitance C t and ; Specifically, through the 24-bit on PCB board 5 ADC model ADS124S08 collects the voltage V across the capacitor network c And the phase difference θ, according to the formula: , calculate the dielectric loss angle, where ω=2πff=50Hz power frequency; S2: Calculation =|C t -C 基准 | / C 基准 ×100%; S3: △C / C>1% or >0.005, output fault code and activate redundancy switching.

[0046] The clear self-diagnosis algorithm process S1-S3 ensures the accuracy and consistency of fault judgment and avoids human misjudgment; the 10ms periodic sampling meets real-time monitoring needs and adapts to the real-time status monitoring requirements of the smart distribution network.

[0047] In the above formula: ω: angular frequency; C: capacitance value; G: conductance; Vc: voltage across the capacitor network; θ: phase difference between voltage and current; Is: standard injection current.

[0048] The shielding net 4 is a double-layer copper wire braided structure, the inner layer aperture is ≤0.5mm, and the outer layer is covered with a polytetrafluoroethylene insulation coating.

[0049] The combination of double-layer copper wire braided structure and polytetrafluoroethylene coating makes the shielding effectiveness of shielding net 4 ≥80dB100MHz-1GHz. According to GB / T 12190-2021 "Measurement method of shielding effectiveness of electromagnetic shielding room", a 100W interference signal is injected into the anechoic chamber, and the measured shielding effectiveness in the 100MHz-1GHz frequency band is ≥82dB, which can improve the shielding effectiveness of shielding net 4 and effectively suppress the influence of electromagnetic interference of the primary conductor on the secondary signal.

[0050] PCB board 5 integrates a temperature compensation circuit, including: Thermistor RT1 mounted on the capacitor network; Reference voltage source U2; Compensation network composed of operational amplifier U3; The compensation network collects temperature signals in real time, calculates the compensation value and corrects the output signal using the following formula: .

[0051] V_out': output voltage after compensation; V_out: original output voltage; : Copper mesh temperature coefficient (-5×10 -5 / ℃); T: real-time temperature (℃); T_ref: standard ambient temperature (25°C); In the compensation formula: α=-5×10 -5 / ℃ copper mesh temperature coefficient, measured according to GB / T 351-2019 "Test method for resistivity of metallic materials"; IEC60068-2-1 standard ambient temperature.

[0052] Thermistor RT1 mounted on the capacitor network has a model parameter of NT C3950K and is mounted on the projection area of ​​the capacitor network; Operational amplifier U3, model parameters are OPA2188, gain bandwidth 10MHz; Compensation execution: When T=85℃, → .

[0053] 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℃-85℃, the accuracy drift is ≤±0.2%, solving the measurement error problem caused by temperature drift of traditional transformers.

[0054] Verifying the temperature compensation effect: At a high temperature of 85°C, the uncompensated error reached +0.82%. The main network capacitance drift △C / C = 0.95%. Before triggering the switching threshold, the compensation circuit output V_out' = 0.997V_out, suppressing the error to +0.07%, which is lower than the 0.5% requirement of IEC61869-1 Class 0.5.

[0055] Self-diagnosis algorithm steps: S0, initialize the reference value; The reference capacitance C reference nominal value is 100pF with an accuracy of ±0.1% and the dielectric loss angle threshold is read from the EEPROM at power-up. =0.005; S1, signal acquisition cycle 10ms; Through 24-bit ADC model ADS124S08 acquisition: Real-time capacity Voltage across the capacitor network Conversion, formula:

[0056] Dielectric loss angle Phase difference θ is calculated using the formula: = ,in .

[0057] S2, calculation of rate of change; Calculate the relative rate of change of capacitance: ; S3, threshold judgment and execution; Condition 1: If : Output fault code: Over limit → code C1; Over limit → code C2; Send a high-level signal 3.3V to the GPIO port to trigger the MOS tube switching circuit; After the switch is completed, the status code C3 is output (UART transmission to the secondary device).

[0058] Condition 2: If the limit is not exceeded → perform PCB accuracy correction and return to step S1 S4. After the switching is completed, the backup capacitor network parameters are continuously monitored using the same algorithm.

[0059] In the above formula: Ct: real-time capacitance value (unit: pF); f: power frequency (unit: Hz); Vc: voltage across the capacitor network (unit: V); Rs: equivalent series resistance (unit: Ω); Is: standard injection current (unit: mA); θ: phase difference between voltage and current (unit: radian); ω: angular frequency (unit: rad / s).

[0060] The charged display sensing capacitor network 2 senses the electric field changes of the high-voltage conductor 1 through the coaxial sensing capacitor network, and transmits it to the charged display through the first signal acquisition terminal 202, thereby realizing the high-voltage charged state 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.

[0061] The PCB board 5 is connected to the secondary signal loop through the connecting pin 302. By adjusting the total capacitance of the secondary capacitor network, such as parallel or series capacitors, manufacturing errors and environmental influences are compensated so that the output signal meets the standard accuracy requirements.

[0062] The shielding net 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 polytetrafluoroethylene insulation coating, which effectively shields the electromagnetic interference of the primary conductor and ensures the stability of signal transmission.

[0063] The redundant backup capacitor network 8 is coaxially connected in parallel with the secondary signal acquisition induction capacitor network 3. The self-diagnosis module monitors the capacitance change rate △C / C and dielectric loss angle in a 10ms cycle. When △C / C>1% or When the value is greater than 0.005, it will automatically switch to the redundant backup capacitor network 8 to avoid measurement inaccuracy caused by aging of the capacitor network.

[0064] PCB board 5 integrates a temperature compensation circuit, which collects temperature signals in real time through the thermistor RT1 mounted on the capacitor network. The compensation network composed of the reference voltage source U2 and the operational amplifier U3 calculates the compensation value according to the formula V_out'=V_out×[1+α(T-T_ref)] to correct the accuracy drift caused by temperature.

[0065] Application scenario: 35kV grid-connected cabinet monitoring in photovoltaic power stations; The sensor is fixed in the narrow space of the GIS cabinet through the product installation terminal 6, which shortens the axial dimension and reduces the weight; The electric field of the high-voltage conductor 1 is synchronously coupled by the charged display inductive capacitor network 2 and the secondary signal acquisition inductive capacitor network 3, and output to the charged display (high voltage indication) and the PCB board 5 (metering signal) respectively; The double-layer shielding net 4 suppresses the harmonic interference of the inverter.

[0066] The above shows and describes 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 above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A voltage divider bushing type voltage sensor, characterized in that: include: A charged display sensing capacitor network (2) is used to sense the high voltage conductor (1) and collect signals; A secondary signal acquisition induction capacitor network (3) is used to sense the high-voltage conductor (1) and acquire signals; A redundant backup capacitor network (8) is coaxially connected in parallel with the secondary signal acquisition induction capacitor network (3); A PCB board (5) capable of adjusting the precision error is used to adjust the capacitance value of the capacitor network; The PCB board (5) is integrated with a self-diagnosis module to monitor capacitor network parameters in real time and control redundant switching.

2. The voltage divider bushing type voltage sensor according to claim 1, characterized in that: The charged display inductive capacitance network (2) comprises a coaxial inductive capacitance network, a first signal acquisition terminal (202) and a fixed terminal (201); a signal is transmitted to the charged display via the first signal acquisition terminal (202).

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

4. The voltage divider bushing type voltage sensor according to claim 1, characterized in that: The PCB board (5) is connected to the second signal acquisition terminal (301) via a connecting pin (302), and the accuracy error is corrected by adjusting the total capacitance of the secondary capacitor network. The connecting pin (302) and the backup network connecting pin (802) are vertically inserted into the symmetrical pads of the PCB board (5).

5. The voltage divider bushing type voltage sensor according to claim 1, characterized in that: It also includes a shielding net (4) for preventing primary interference signals, which is wrapped around the outside of all capacitor nets and is used to shield the interference signals of the primary conductor.

6. The voltage divider bushing type voltage sensor according to claim 1, characterized in that: It also includes a product installation terminal (6) and a product insulation layer (7), wherein the product installation terminal (6) is used to fix the sensor, and the product insulation layer (7) covers the outside of the shielding net (4).

7. The voltage divider bushing type voltage sensor according to claim 1, characterized in that: The self-diagnosis module monitors the capacitance change rate ΔC / C and dielectric loss angle of the secondary capacitor network. , when △C / C>1% or When the voltage is >0.005, it will automatically switch to the redundant backup capacitor network (8).

8. The voltage divider bushing type voltage sensor according to claim 7, characterized in that: The self-diagnosis module performs capacitance and dielectric loss monitoring in a 10ms cycle. The self-diagnosis module performs the following algorithm in a 10ms cycle: S1: Collect capacitance C t and ; S2: Calculate △C / C=|C t -C 基准 | / C 基准 ×100%; S3: If △C / C>1% or >0.005, output fault code and activate redundancy switching.

9. The voltage divider bushing type voltage sensor according to claim 5, characterized in that: The shielding net (4) is a double-layer copper wire braided structure, the inner layer aperture is ≤0.5 mm, and the outer layer is covered with a polytetrafluoroethylene insulation coating.

10. The voltage divider bushing type voltage sensor according to claim 5, characterized in that: The PCB board (5) integrates a temperature compensation circuit, comprising: Thermistor (RT1) mounted on the capacitor network; Reference voltage source (U2); The compensation network formed by the operational amplifier (U3); The compensation network collects temperature signals in real time, calculates the compensation value and corrects the output signal using the following formula: 。

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