CN113253003A - Transformer electric field detection device and method - Google Patents
Transformer electric field detection device and method Download PDFInfo
- Publication number
- CN113253003A CN113253003A CN202110528289.4A CN202110528289A CN113253003A CN 113253003 A CN113253003 A CN 113253003A CN 202110528289 A CN202110528289 A CN 202110528289A CN 113253003 A CN113253003 A CN 113253003A
- Authority
- CN
- China
- Prior art keywords
- unit
- electric field
- transformer
- voltage
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/12—Measuring electrostatic fields or voltage-potential
- G01R29/14—Measuring field distribution
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/30—Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention provides a transformer electric field detection device and a method, comprising an MEMS electric field sensor, a current-to-voltage unit and a data acquisition unit; the MEMS electric field sensor is used for outputting current based on an electric field of the transformer; the current-to-voltage unit is used for converting the current into a voltage signal; the data acquisition unit is used for acquiring parameters of the voltage signals; the MEMS electric field sensor is small in size, high in sensitivity, suitable for electric field detection in a narrow space and free of distortion to an electric field, generates current according to the electric field, converts the current into a voltage signal, and judges the state of the transformer according to parameters of the voltage signal; the detection device can detect under the live operation of the transformer.
Description
Technical Field
The invention belongs to the technical field of transformer detection, and particularly relates to a transformer electric field detection device and method.
Background
Electric power is an important productivity of economic development and a basic guarantee of the happy life of residents. Due to the unbalance of the supply and demand places of our electric power, a large number of 'west electric and east electric' projects appear. In both ac transmission and dc transmission projects, transformers are one of the most important devices. A complex electromagnetic environment exists near the transformer, and when a power transmission system fails, the transformer may have overvoltage and damage an insulation system of the transformer. When the insulation of the transformer is abnormal, even if no overvoltage exists, the electric field near the insulation system of the transformer is transformed in a more normal condition. Therefore, real-time detection of the electric field in the space near the transformer is of great significance for transformer state estimation and system fault diagnosis.
The operation state of the transformer is closely related to the value of the electric field around the transformer. Although various electric field sensors such as a rotary voltmeter, a Pockels effect type electric field sensor and a Kerr effect type electric field sensor exist at present, the existing electric field sensors are narrow in transformer space and large in size, and a conductive metal component in the existing electric field sensors can significantly influence a measured electric field, easily causes distortion in the electric field and is not suitable for detecting the electric field in a narrow space. The whole set of optical electric field sensor is complex in equipment, expensive in manufacturing cost, easy to be affected by environmental factors such as temperature and humidity, and poor in stability. And at present, the measurement is non-electrified, namely, the transformer oil needs to be taken out separately and then the electric field characteristic of the transformer oil is measured. To date, no mature solution for measuring the electric field strength near an insulation system under the condition of live operation of a transformer exists.
Disclosure of Invention
In view of the above problems, the present invention is to provide a transformer electric field detection apparatus and method, which has a reasonable structural design, reduces the space occupation, can perform live measurement real-time measurement, and is more convenient and faster in measurement.
In order to achieve the purpose, the invention adopts the technical scheme that the transformer electric field detection device comprises a current-to-voltage unit and a data acquisition unit;
the current-to-voltage unit is used for converting the current into a voltage signal;
the data acquisition unit is used for acquiring parameters of the voltage signals.
The MEMS electric field sensor is used for outputting current based on an electric field of the transformer.
Preferably, the current-to-voltage unit comprises a first operational amplifier and a second operational amplifier, inverting input ends of the first operational amplifier and the second operational amplifier are connected with the same potential, and resistors are connected in series between output ends of the first operational amplifier and the second operational amplifier and the respective inverting input ends; the output end of the first operational amplifier is connected with the positive phase input end of the second operational amplifier through a switch and a capacitor which are connected in parallel, and the output end of the second operational amplifier is connected with the positive phase input end of the first operational amplifier through a switch and a capacitor which are connected in parallel.
Preferably, the power supply further comprises a voltage amplifying unit, wherein the voltage amplifying unit is used for amplifying the voltage signal output by the current-to-voltage converting unit, the voltage amplifying unit is connected between the current-to-voltage converting unit and the data acquisition unit, and the data acquisition unit is used for acquiring the parameter of the amplified voltage signal.
Preferably, the voltage amplifying unit includes a third operational amplifier, a positive phase input terminal and an inverse phase input terminal of the third operational amplifier are respectively connected in series with a resistor, and an output terminal of the third operational amplifier is connected in series with the positive phase input terminal and the inverse phase input terminal with a resistor.
Preferably, the voltage signal processing device further comprises a filtering unit, wherein the filtering unit is used for filtering the voltage signal, and the data acquisition unit is used for acquiring parameters of the filtered voltage signal.
Preferably, the filtering unit comprises a fourth operational amplifier, the positive input end of the fourth operational amplifier is grounded, and the negative input end and the output end of the fourth operational amplifier are connected through a resistor and a capacitor which are connected in parallel.
Preferably, the device further comprises a data transmitting unit, wherein the data transmitting unit is used for transmitting the parameters of the voltage signals.
Preferably, the power supply device further comprises a CT power supply unit, wherein the CT power supply unit is used for collecting electric energy and transmitting the electric energy to the MEMS electric field sensor, the current-to-voltage unit, the data collection unit, the filtering unit, the voltage amplification unit and the data transmission unit.
Preferably, the power supply device further comprises a rechargeable battery, the CT power supply unit is used for conveying electric energy to the rechargeable battery, and the rechargeable battery is used for conveying electric energy to the MEMS electric field sensor, the current-to-voltage unit, the data acquisition unit, the filtering unit, the voltage amplification unit and the data transmission unit.
The invention also provides a transformer electric field detection method, which applies the transformer electric field detection device to install the MEMS electric field sensor around the inlet and outlet wires of the transformer and/or around the winding of the transformer and/or in the transformer oil; the MEMS electric field sensor generates induced charges under the excitation of an electric field of the transformer, the induced charges are led out to form current, the current is transmitted to the current-to-voltage unit, the induced current is converted into a voltage signal through the current-to-voltage unit, the data acquisition unit is connected with the current-to-voltage unit to acquire parameters of the voltage signal, and the state of the transformer is analyzed through the parameters of the voltage signal acquired by the data acquisition unit.
Compared with the prior art, the transformer electric field detection device has the advantages that the MEMS electric field sensor is small in size, high in sensitivity and suitable for electric field detection in a narrow space, distortion of an electric field is avoided, the MEMS electric field sensor generates current according to the electric field, converts the current into a voltage signal and judges the state of the transformer according to the parameters of the voltage signal; the detection device can realize detection under the live-line operation of the transformer, and the detection method is more convenient.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of an electric field detection apparatus for a transformer in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a current to voltage conversion unit according to an embodiment of the present invention;
FIG. 3 shows a schematic diagram of a voltage amplification unit in an embodiment of the invention;
FIG. 4 shows a schematic diagram of a filtering unit in an embodiment of the invention;
fig. 5 is a schematic installation diagram of the transformer electric field detection device according to the embodiment of the invention.
In the figure, a first operational amplifier 101, a second operational amplifier 102, a third operational amplifier 103, and a fourth operational amplifier 104.
Detailed Description
In order to make the objects, 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention aims at the characteristics of the transformer, utilizes an MEMS (Micro-Electro-Mechanical System ) electric field sensor to realize the electric field detection near the transformer, and carries out the state analysis of the transformer and the state and insulation prediction of the power System where the transformer is positioned. MEMS electric field sensors are also referred to as MEMS electric field chips in other literature. In the embodiment, a silicon-based material is arranged in the MEMS electric field sensor, the silicon-based material can generate induced charges in a transformer electric field, the induced charges are extracted, the original transformer electric field state can be reversely deduced, and the states of the transformer and a power system where the transformer is located can be known according to the transformer electric field state.
Referring to fig. 1, an embodiment of the present invention provides a transformer electric field detection apparatus, including an MEMS electric field sensor and a signal system, where the signal system includes a current-to-voltage conversion unit and a data acquisition unit, and functions and mutual connection relationships of the MEMS electric field sensor and the signal system are as follows.
The MEMS electric field sensor is arranged near or in the transformer, the MEMS electric field sensor generates induced charges under the excitation of an electric field of the transformer, the induced charges are led out to form current, the current is transmitted to the current-to-voltage unit, the induced current is converted into a voltage signal by the current-to-voltage unit, the data acquisition unit is connected with the current-to-voltage unit, the data acquisition unit acquires parameters of the voltage signal, the parameters can be waveform, peak value, effective value, average value and the like of the voltage signal, corresponding parameters are selected according to actual needs, and the state of the transformer can be analyzed based on the parameters, such as temperature, load, insulation performance and the like of the transformer. The transformer is part of the power systemIn addition, when a fault occurs at a certain place of the power system, the transformer can also reflect the state of the power system to a certain extent。
The induced charge generated by the MEMS electric field sensor is small, so that the converted voltage signal is also small, and further the detection error is also large. The data acquisition unit acquires parameters of the amplified voltage signal.
In order to improve the pulsation degree of the voltage signal, the signal system further comprises a filtering unit, the filtering unit is used for filtering the amplified voltage signal to obtain the voltage signal with the ripple removed, and the data acquisition unit is used for acquiring parameters of the filtered voltage signal. The transformer electric field detection device comprises a transformer, a data acquisition unit, a background monitoring system and a data transmission unit, wherein the transformer is arranged in the power system, the data acquisition unit is used for acquiring parameters of the transformer, and the data transmission unit is used for transmitting the parameters to the background monitoring system.
To sum up, after the MEMS sensor generates a current in the transformer electric field, the current flows into the current-to-voltage conversion unit, the current signal is converted into a voltage signal, the voltage signal flows into the voltage amplification unit again, the voltage amplification unit amplifies the voltage signal, the filtering unit filters the amplified voltage signal, the data acquisition unit acquires the filtered voltage signal parameters, the data acquisition unit transmits the parameters to the data transmission unit, and the data transmission unit transmits the voltage signal parameters to the background monitoring system. In another design, the current signal may be converted to obtain a voltage signal, and the voltage signal may be filtered and then amplified.
In this embodiment, the power supply mode for supplying power to the MEMS electric field sensor, the signal system, and the data transmitting unit is a CT (Current Transformer) power supply + rechargeable battery. Therefore, the electric field detection device further comprises a CT electricity taking unit and a rechargeable battery, wherein the CT electricity taking unit obtains electric energy by using a power transmission line near the transformer and transmits the obtained electric energy to the MEMS electric field sensor, the signal system and the data transmitting unit. And meanwhile, the acquired electric energy is sent to the rechargeable battery, and the CT electricity taking unit does not deliver the electric energy to the rechargeable battery any more under the condition that the rechargeable battery is fully charged. Under the condition that a power transmission line near the transformer is normally electrified, the CT power taking unit transmits electric energy to the MEMS electric field sensor, the signal system and the data transmitting unit, and the rechargeable battery does not transmit electric energy to the MEMS electric field sensor, the signal system and the data transmitting unit. Under the condition that a power transmission line near the transformer is not electrified, the rechargeable battery transmits electric energy to the MEMS electric field sensor, the signal system and the data transmitting unit. Therefore, the reliability and the continuity of power supply of the transformer detection device can be guaranteed no matter whether the power transmission line near the transformer is electrified or uncharged.
In another design mode, only the CT power taking unit is provided, instead of the rechargeable battery, and only the CT power taking unit is used to supply power to other electrical components in the transformer detection device.
The MEMS electric field sensor, the signal system, the data transmitting unit, the CT electricity taking unit and the rechargeable battery are connected through hardware, and specifically can be connected through a conducting wire.
Exemplarily, referring to fig. 2, which is a schematic circuit structure diagram of a current-to-voltage unit, a switched capacitor circuit is adopted in the current-to-voltage circuit in this embodiment, current signals generated by an MEMS respectively enter positive input terminals of two operational amplifiers, inverting input terminals of the two operational amplifiers are connected to the same potential, and resistors are connected in series between output terminals of the two operational amplifiers and the respective inverting input terminals. The two operational amplifiers are named as a first operational amplifier 101 and a second operational amplifier 102, respectively, a switch and a capacitor are connected in series between the output end of the first operational amplifier 101 and the non-inverting input end of the second operational amplifier 102, and a switch and a capacitor are connected in series between the output end of the second operational amplifier 102 and the non-inverting input end of the first operational amplifier 101. A weak current signal generated by the MEMS sensor crosses the first stage of the group amplifying circuit, and the current is amplified in a symmetrical coupling mode. Two identical operational amplifiers are used, a positive signal path and a negative signal path of the operational amplifiers are completely symmetrical, and the inverting input ends of the two operational amplifiers are connected with the same potential, so that the symmetry of the signal paths of the amplifying circuit is ensured, and the amplification times of positive and negative signal channels are the same. Meanwhile, the feedback output ends of the positive-phase signal channel and the negative-phase signal channel are in cross coupling, so that the symmetry and stability of signal amplification are enhanced.
Referring to fig. 3, which is a schematic circuit structure diagram of the voltage amplifying unit, two paths of voltages output by the current-to-voltage converting unit respectively enter a positive input terminal and a negative input terminal of a third operational amplifier 103 in the voltage amplifying unit, and a resistor is connected in series between the current-to-voltage converting unit and the positive input terminal and the negative input terminal of the third operational amplifier 103 to perform a current limiting function. The output end of the third operational amplifier 103 is connected in series with the positive phase input end and the negative phase input end by resistors, and the voltage amplification unit in this embodiment performs voltage amplification on one hand and converts two voltage signals into one voltage signal on the other hand.
Referring to fig. 4, the circuit structure of the filtering unit is shown schematically, the circuit is a low-pass filtering circuit, and includes a fourth operational amplifier 104, a resistor and a capacitor connected in parallel, a positive input terminal of the fourth operational amplifier 104 is grounded, and a resistor and a capacitor are connected in parallel between an inverted input terminal and an output terminal of the fourth operational amplifier 104. The voltage signal output by the voltage amplifying unit enters the inverting input terminal of the fourth operational amplifier 104.
In this embodiment, a transformer electric field detection method is further provided, where the transformer electric field detection device is applied, referring to fig. 5, an MEMS electric field sensor is installed around an incoming line of a transformer, that is, a position indicated by 1 in fig. 5, or around an outgoing line, that is, a position indicated by 2 in fig. 5, or around a winding of the transformer, that is, a position indicated by 3 in fig. 5, or in transformer oil, where no reference is made in fig. 5, a plurality of transformer electric field detection devices may be installed on one transformer, and the plurality of transformer electric field detection devices may be installed at the several different positions, respectively, so as to better detect a state of the transformer.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. The transformer electric field detection device is characterized by comprising a current-to-voltage unit and a data acquisition unit; the current-to-voltage unit is used for converting the current into a voltage signal; the data acquisition unit is used for acquiring parameters of the voltage signals.
2. The transformer electric field detection device according to claim 1, characterized in that the current-to-voltage unit comprises a first operational amplifier (101) and a second operational amplifier (102), inverting inputs of the first operational amplifier (101) and the second operational amplifier (102) are connected to the same potential, and resistors are connected in series between output terminals of the first operational amplifier (101) and the second operational amplifier (102) and the respective inverting inputs; the output end of the first operational amplifier (101) is connected with the non-inverting input end of the second operational amplifier (102) through a switch and a capacitor which are connected in parallel, and the output end of the second operational amplifier (102) is connected with the non-inverting input end of the first operational amplifier (101) through a switch and a capacitor which are connected in parallel.
3. The transformer electric field detection device according to claim 1, further comprising a voltage amplification unit, wherein the voltage amplification unit is configured to amplify the voltage signal output by the current-to-voltage conversion unit, the voltage amplification unit is connected between the current-to-voltage conversion unit and the data acquisition unit, and the data acquisition unit is configured to acquire parameters of the amplified voltage signal.
4. The transformer electric field detection device according to claim 3, characterized in that the voltage amplification unit comprises a third operational amplifier (103), wherein resistors are respectively connected in series to a positive input terminal and a negative input terminal of the third operational amplifier (103), and resistors are connected in series to an output terminal of the third operational amplifier (103), the positive input terminal and the negative input terminal.
5. The transformer electric field detection device of claim 1, further comprising a filtering unit, wherein the filtering unit is configured to filter the voltage signal, and the data acquisition unit is configured to acquire parameters of the filtered voltage signal.
6. The transformer electric field detection device according to claim 5, characterized in that the filtering unit comprises a fourth operational amplifier (104), a non-inverting input terminal of the fourth operational amplifier (104) is grounded, and a non-inverting input terminal and an output terminal of the fourth operational amplifier (104) are connected through a resistor and a capacitor connected in parallel.
7. The apparatus of claim 1, further comprising a data transmitter for transmitting the parameters of the voltage signal.
8. The transformer electric field detection device according to any one of claims 1 to 7, further comprising a CT electricity taking unit for collecting electric energy and transmitting the electric energy to the MEMS electric field sensor, the current-to-voltage unit, the data collecting unit, the filtering unit, the voltage amplifying unit and the data transmitting unit.
9. The transformer electric field detection device of claim 8, further comprising a rechargeable battery, wherein the CT power taking unit is configured to deliver electric energy to the rechargeable battery, and the rechargeable battery is configured to deliver electric energy to the MEMS electric field sensor, the current-to-voltage conversion unit, the data acquisition unit, the filtering unit, the voltage amplification unit, and the data transmission unit.
10. A method for detecting the electric field of a transformer, which is characterized in that the device for detecting the electric field of the transformer as claimed in any one of claims 1 to 9 is used, and MEMS electric field sensors are arranged around the inlet and outlet wires of the transformer, and/or around the winding of the transformer, and/or in transformer oil; the MEMS electric field sensor generates induced charges under the excitation of an electric field of the transformer, the induced charges are led out to form current, the current is transmitted to the current-to-voltage unit, the induced current is converted into a voltage signal through the current-to-voltage unit, the data acquisition unit is connected with the current-to-voltage unit to acquire parameters of the voltage signal, and the state of the transformer is analyzed through the parameters of the voltage signal acquired by the data acquisition unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110528289.4A CN113253003A (en) | 2021-05-14 | 2021-05-14 | Transformer electric field detection device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110528289.4A CN113253003A (en) | 2021-05-14 | 2021-05-14 | Transformer electric field detection device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113253003A true CN113253003A (en) | 2021-08-13 |
Family
ID=77181964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110528289.4A Pending CN113253003A (en) | 2021-05-14 | 2021-05-14 | Transformer electric field detection device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113253003A (en) |
-
2021
- 2021-05-14 CN CN202110528289.4A patent/CN113253003A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201681143U (en) | Online monitoring device for mechanical characteristic of high-voltage circuit breaker | |
| CN201373895Y (en) | Online monitoring device of zinc oxide arrester (MOA) | |
| CN202533545U (en) | Power transmission network fault detection system based on internet of things technology | |
| CN110007133B (en) | Digital AC/DC current sensor and current detection method | |
| CN205404690U (en) | Fault indicator testing arrangement | |
| CN102680862A (en) | Device and method for online monitoring of partial discharge of shunt capacitor | |
| CN210128995U (en) | Charging voltage acquisition circuit, charging fault diagnosis circuit and charging device | |
| CN112904147B (en) | Power transmission line fault and pre-discharge monitoring device and signal processing method | |
| CN107765084B (en) | Universal voltage input power frequency signal frequency measurement system | |
| CN211453790U (en) | Non-contact electric field measurement system for fault indicator | |
| CN105929218A (en) | Two-channel non-contact measurement device of voltage below 1000V | |
| CN106771639B (en) | High pressure pole tower ground resistance on-line monitoring system | |
| CN216979183U (en) | Transformer electric field detection device | |
| CN113253003A (en) | Transformer electric field detection device and method | |
| CN215375643U (en) | Arc detection sensor and arc detection circuit | |
| CN102759681A (en) | Transformer core ground fault monitoring device | |
| CN102095924A (en) | Detection device for power utilization and measurement of high-voltage circuit | |
| CN115327218A (en) | Non-invasive power factor measuring device and split type electric power measuring system | |
| CN210626597U (en) | Detection apparatus for utilize capacitive sleeve pipe end screen to carry out homonymy high-tension apparatus partial discharge | |
| CN105785246A (en) | Live-line detecting and on-line monitoring device used for ultrahigh-voltage power cable insulation diagnosis | |
| CN110146863B (en) | Hump radar equipment online monitoring system and hump radar equipment online monitoring method | |
| CN105629138A (en) | Multifunctional suspension type porcelain insulator on-line detector | |
| CN209690446U (en) | Distribution line insulation detection device | |
| CN203191496U (en) | RS485 bus based distributed power grid operating equipment insulation online monitoring device | |
| CN112462126A (en) | Track circuit outdoor equipment with non-contact voltage acquisition function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |