阅读说明：本技术 一种高压电缆护层接地箱检测装置 (High tension cable sheath ground connection case detection device ) 是由 杨振 杨震威 于 2020-12-29 设计创作，主要内容包括：本发明涉及一种高压电缆护层接地箱检测装置,包括圆筒状的测量模块,测量模块套接在被测导线外部获取被测导线的电位信号,通过采集传输模块传递给上位机；测量模块与被测导线同轴设置,内层为感应电极,中间层为有源屏蔽层,最外层为接地屏蔽层。利用获取到的电位信号以非接触的方式实现护层接地线电压的检测和保护器放电次数的监测,能够提供足够高的绝缘强度,实现电气隔离,并能实现远程监控。(The invention relates to a high-voltage cable sheath grounding box detection device which comprises a cylindrical measurement module, wherein the measurement module is sleeved outside a measured wire to acquire a potential signal of the measured wire and transmits the potential signal to an upper computer through an acquisition and transmission module; the measuring module is coaxial with the measured lead, the inner layer is an induction electrode, the middle layer is an active shielding layer, and the outermost layer is a grounding shielding layer. The voltage of the grounding line of the protective layer and the discharge frequency of the protector are detected in a non-contact mode by utilizing the acquired potential signal, so that high enough insulation strength can be provided, electrical isolation is realized, and remote monitoring can be realized.)

1. The utility model provides a high tension cable sheath grounding box detection device which characterized in that: the device comprises a cylindrical measuring module, wherein the measuring module is sleeved outside a measured wire to obtain a potential signal of the measured wire and transmits the potential signal to an upper computer through an acquisition and transmission module; the measuring module is coaxial with the measured lead, the inner layer is an induction electrode, the middle layer is an active shielding layer, and the outermost layer is a grounding shielding layer.

2. The apparatus of claim 1, wherein the apparatus further comprises: the inner diameter of the measuring module is larger than the outer diameter of the measured lead.

3. The apparatus of claim 1, wherein the apparatus further comprises: and the insulating outer layer of the measured lead is close to the induction electrode of the measuring module.

4. The apparatus of claim 1, wherein the apparatus further comprises: the acquisition and transmission module receives the potential signal of the measured wire acquired by the measurement module and transmits the potential signal to the single chip microcomputer to calculate and obtain a voltage signal of the measured wire.

5. The device of claim 4, wherein the grounding box comprises: the single chip microcomputer receives the potential signal acquired by the measuring module, and calculates to obtain a voltage signal of the measured wire based on an electric field coupling principle and a Gaussian theorem.

6. The apparatus of claim 1, wherein the apparatus further comprises: the acquisition and transmission module comprises an amplification module, a signal processing module, a discharge detection module and a communication module which are sequentially connected.

7. The device of claim 6, wherein the grounding box comprises: the amplification module obtains the voltage of the displacement current on the input impedance of the amplifier through the floating potential obtained on the sensing electrode of the measurement module, and amplifies signals in a differential mode of double-operational-amplifier inverting input.

8. The device of claim 6, wherein the grounding box comprises: the discharge detection module captures the residual voltage state of the protector after discharge and transmits the residual voltage state to the single chip microcomputer through the communication module.

9. The apparatus of claim 8, wherein the grounding box comprises: after the single chip microcomputer collects the voltage information and the discharge state, the voltage information and the discharge state are uploaded to a server at the upper computer end through an Ethernet interface to be recorded, and the discharge frequency of the protector is monitored.

10. The apparatus of claim 1, wherein the apparatus further comprises: the tested lead is a grounding wire of the cable sheath.

Technical Field

The invention relates to the field of power systems, in particular to a high-voltage cable sheath grounding box detection device.

Background

The high-voltage power cable sheath grounding protection box is an important device in the operation of a cable circuit, is also a best monitoring point in the circuit, and can realize the monitoring of the sheath voltage and the monitoring of the discharge times of a sheath protector.

Traditional electromagnetic induction formula voltage sensor of formula is owing to have electrical connection with the sheath, has the dielectric strength problem, and common sheath discharge number of times monitoring also need establish ties with the protector and use the counter that adds up of physical mode, can't realize remote monitoring, and this kind of direct connection mode has certain risk in addition, and when the protector discharges, the residual voltage level is up to 10KV, has the risk of puncturing the short circuit when pressure measuring device is ageing or malfunctioning.

Disclosure of Invention

One or more embodiments provide the following technical solutions:

a high-voltage cable sheath grounding box detection device comprises a cylindrical measurement module, wherein the measurement module is sleeved outside a measured lead to acquire a potential signal of the measured lead and transmits the potential signal to an upper computer through an acquisition and transmission module;

the measuring module is coaxial with the measured lead, the inner layer is an induction electrode, the middle layer is an active shielding layer, and the outermost layer is a grounding shielding layer.

The inner diameter of the measuring module is larger than the outer diameter of the measured lead, and the insulating outer layer of the measured lead is close to the induction electrode of the measuring module.

The acquisition and transmission module receives the potential signal of the measured wire acquired by the measurement module and transmits the potential signal to the single chip microcomputer to calculate and obtain a voltage signal of the measured wire.

The acquisition and transmission module comprises an amplification module, a signal processing module, a discharge detection module and a communication module which are connected in sequence.

The amplification module obtains the voltage of the displacement current on the input impedance of the amplifier through the floating potential obtained on the induction electrode of the measurement module, and amplifies signals in a differential mode of double-operational-amplifier inverting input.

The discharge detection module captures the residual voltage state of the protector after discharge and transmits the residual voltage state to the single chip microcomputer through the communication module.

After the single chip microcomputer collects the voltage information and the discharge state, the voltage information and the discharge state are uploaded to a server at the upper computer end through an Ethernet interface to be recorded, and the discharge frequency of the protector is monitored.

The single chip microcomputer receives the potential signal acquired by the measuring module, and the voltage signal of the measured wire is calculated based on the electric field coupling principle and the Gaussian theorem.

The tested lead is the grounding wire of the cable sheath.

The above one or more technical solutions have the following beneficial effects:

1. the voltage of the grounding line of the protective layer and the discharge frequency of the protector are detected in a non-contact mode by utilizing the acquired potential signal, so that high enough insulation strength can be provided, electrical isolation is realized, and remote monitoring can be realized.

2. The outer insulating layer of the measured lead and the outer insulating layer of the measuring module completely isolate the measured lead from the induction electrode, the electrical performance of the circuit to be measured is not affected, and the hidden trouble of short circuit caused by contact measurement is avoided.

3. The installation is convenient, and no extra operation is needed to be carried out on the cable to be tested.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a schematic diagram of the signal coupling principle provided by one or more embodiments of the present invention;

FIG. 2 is a schematic diagram of a coupling equivalent circuit provided by one or more embodiments of the invention;

fig. 3 is a schematic structural diagram of an apparatus according to one or more embodiments of the present invention.

Detailed Description

The following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

As described in the background art, the high-voltage power cable sheath grounding protection box is used as a monitoring point in the operation of a cable line, so that the monitoring of the sheath voltage and the monitoring of the discharge times of a sheath protector can be realized, and the traditional electromagnetic induction type voltage sensor and the sheath are in contact electrical connection, and the insulation strength needs to be considered; meanwhile, the monitoring of the discharge frequency of the sheath also needs a physical contact mode of the sheath and the protector in series connection, the physical contact mode is easily influenced by the service life of the circuit and the measuring device when the monitoring of the voltage of the sheath and the discharge frequency of the sheath protector are realized, and the breakdown risk exists.

The first embodiment is as follows:

as shown in fig. 1-3, a high voltage cable sheath grounding box detection device comprises a cylindrical measurement module, wherein the measurement module acquires a potential signal of a measured wire and transmits the potential signal to an upper computer through a collection and transmission module.

The measuring module comprises an induction electrode, an active shielding layer and a grounding shielding layer which are coaxially arranged from inside to outside in sequence. The measuring module is coaxial with the measured lead, the inner layer is an induction electrode, the middle layer is an active shielding layer, and the outermost layer is a grounding shielding layer.

The measuring module is based on the principle of electric field coupling, and an equivalent charge method can prove that under certain boundary conditions, the electric field around the electrified conductor has a linear relation with the potential thereof.

When the sensing electrode for measurement is placed near the conductor to be measured, the sensing electrode generates sensing charges through electric field coupling, the changed sensing charges form displacement current, voltage drop is generated in the load resistor, and the Gaussian theorem proves that the voltage drop of the resistor is proportional to the change rate of the electric field at the electrode, so that the voltage drop of the load resistor and the potential of the conductor to be measured change linearly.

Ui is measured voltage, Cc is equivalent mutual capacitance between the induction electrode and a measured conductor, Cz is stray capacitance of the measurement module to the ground, R is sampling resistance, and the equivalent mutual capacitance can be a first-order circuit, and the transfer function is as follows:

the circuit is operated in a differential mode by selecting a proper sampling resistance value, and the circuit is used as a high-pass filter which has larger operation measurement bandwidth and can be used for measuring impulse voltage.

Because the displacement current is small, the sampling resistance value has a large resistance value and can be converted into a large voltage signal, and because the detection module needs a certain input current to normally work, the maximum resistance value of the sampling resistor is limited. When selecting, firstly, the dielectric constant of common insulating materials of the cable and the outer layer insulation thickness of the common cable are determined, and the range of the resistance value is determined by calculation.

The measuring module obtains potential signals of the measured wires, and voltage signals of the measured wires are obtained through calculation after the potential signals are transmitted to the upper computer through the acquisition and transmission module.

During installation, the measuring module is only required to be sleeved on the insulating outer layer of the wire to be measured, the insulating outer layer of the wire to be measured is close to the induction electrode of the measuring module and is not in contact with the induction electrode, the insulating outer layer of the wire to be measured and the insulating outer layer of the measuring module completely isolate the wire to be measured from the induction electrode, the electrical performance of a circuit to be measured is not affected, the hidden short circuit trouble caused by measurement relief is avoided, the measuring module and the wire to be measured are high in isolation and pressure resistance, meanwhile, the installation is convenient, and any extra operation is not required to be carried out on the.

The acquisition and transmission module comprises a differential amplification module, a signal processing module, a discharge detection module and a communication module which are sequentially connected.

The amplification module obtains the voltage of the displacement current on the input impedance of the amplifier through the floating potential obtained on the induction electrode of the measurement module, and amplifies the signal in a differential mode of double-operational-amplifier inverting input, so that common-mode interference signals in a measurement environment are effectively removed, the input impedance of the amplifier is improved, and the amplitude-frequency and phase-frequency characteristics of the signal are effectively improved.

The discharging detection module can capture the residual voltage state of the protector after discharging and transmit the residual voltage state to the single chip microcomputer, and the single chip microcomputer acquires voltage information and the discharging state and uploads the voltage information and the discharging state to a server at the end of an upper computer through an Ethernet interface to record so as to monitor the discharging times of the protector.

The discharge detection module comprises an input protection part, a high-speed comparator and a monostable trigger (signals still come from the measurement module); the protector has high discharge frequency and high discharge residual voltage level, the input protection part reduces the voltage according to a certain proportion and then enters a high-speed comparator, the comparator reverses after exceeding a threshold value, a monostable trigger triggered by a rising edge widens the pulse and then sends the pulse to an external interrupt pin of the single chip microcomputer, and the single chip microcomputer records the counting process of one-time discharge of the protector.

The potential signal that the measuring module that utilizes and not contact with the wire of being surveyed obtained detects with the protector number of times that discharges of function and the realization non-contact measurement voltage, does not have the physical connection between detection device and the wire of being surveyed, and then can provide high enough dielectric strength, realizes electrical isolation to can realize remote monitoring.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.