CN211928030U - Ground resistance measuring device suitable for transformer substation's surge monitoring is used - Google Patents
Ground resistance measuring device suitable for transformer substation's surge monitoring is used Download PDFInfo
- Publication number
- CN211928030U CN211928030U CN202020241328.3U CN202020241328U CN211928030U CN 211928030 U CN211928030 U CN 211928030U CN 202020241328 U CN202020241328 U CN 202020241328U CN 211928030 U CN211928030 U CN 211928030U
- Authority
- CN
- China
- Prior art keywords
- unit
- circuit
- power supply
- measuring device
- device suitable
- 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.)
- Active
Links
Images
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model provides a grounding resistance measuring device suitable for surge monitoring of transformer substation, which comprises a grounding loop, a variable frequency power supply unit, an external unit, a weak signal conditioning unit, a signal acquisition unit, a power supply unit, an on/off control circuit, a self-checking circuit, a control unit and a bleeder circuit, wherein the variable frequency power supply unit is respectively connected with the grounding loop and the bleeder circuit, the variable frequency power supply unit, the external unit, the signal acquisition unit, the on/off control circuit and the self-checking circuit are respectively connected with the control unit, the grounding loop is connected with the weak signal conditioning unit, the weak signal conditioning unit and the bleeder circuit are both connected with the signal acquisition unit, and the power supply unit supplies power to the whole device. The accuracy of measurement is improved, and the method has a good application prospect.
Description
Technical Field
The utility model relates to an earth resistance measurement field, concretely relates to earth resistance measuring device suitable for surge monitoring of transformer substation uses.
Background
The grounding resistance is an important technical index of the grounding of the power system, and the accurate acquisition of the grounding resistance value is the premise of ensuring the safe operation of the power system. At present, the problems of low precision, complex measuring process, poor anti-interference capability and the like generally exist in domestic grounding resistance measuring instruments, and foreign advanced products cannot be widely applied due to high price.
SUMMERY OF THE UTILITY MODEL
The utility model aims at solving the above-mentioned not enough, provide a ground resistance measuring device suitable for surge monitoring of transformer substation uses.
The utility model aims at realizing through the following technical scheme:
the utility model provides a ground resistance measuring device suitable for surge monitoring of transformer substation uses, including ground return circuit, variable frequency power supply unit, external unit, weak signal conditioning unit, signal acquisition unit, the power supply unit, power-on/off control circuit, self-checking circuit, the control unit and bleeder circuit, variable frequency power supply unit connects ground return circuit and bleeder circuit respectively, variable frequency power supply unit, external unit, signal acquisition unit, power-on/off control circuit and self-checking circuit connect the control unit respectively, ground return circuit connects weak signal conditioning unit, weak signal conditioning unit and bleeder circuit all connect signal acquisition unit, the power supply unit supplies power for whole device.
The ground circuit includes a circuit under test, a voltage jaw, and a current jaw.
The variable frequency power supply unit comprises a complementary power amplifying circuit and a second-order low-pass filter circuit.
The external unit comprises an LCD display unit, a key unit, an RS232 interface and a JTAG interface.
The weak signal conditioning unit comprises a preamplifier circuit, a power frequency trap circuit, a secondary amplifier circuit and a fourth-order band-pass filter unit.
The signal acquisition unit comprises a low-pass filter circuit and a polarity conversion circuit.
The control unit adopts MSP430F169 single chip microcomputer chip.
The utility model discloses following profitable effect has:
the utility model relates to a rationally, convenient to use adopts the frequency conversion measurement technique, has avoided ground net interference current and power frequency interference effectively when producing excitation signal, has improved the measuring degree of accuracy, has fine application prospect.
Drawings
Fig. 1 is a schematic view of the overall structure of the present invention;
FIG. 2 is a circuit diagram of a variable frequency power supply unit of the present invention;
FIG. 3 is a circuit diagram of a pre-amplifier circuit according to the present invention;
fig. 4 is a circuit diagram of the fourth-order band-pass filter of the present invention.
Detailed Description
The invention will be further described with reference to the accompanying drawings:
as shown in fig. 1, a ground resistance measuring device suitable for monitoring a transformer substation surge includes a ground loop 1, a variable frequency power supply unit 2, an external unit 3, a weak signal conditioning unit 4, a signal acquisition unit 5, a power supply unit 6, an on/off control circuit 7, a self-checking circuit 8, a control unit 9 and a voltage dividing circuit 10, where the variable frequency power supply unit 2 is connected to the ground loop 1 and the voltage dividing circuit 10 respectively, the variable frequency power supply unit 2, the external unit 3, the signal acquisition unit 5, the on/off control circuit 7 and the self-checking circuit 8 are connected to the control unit 9 respectively, the ground loop 1 is connected to the weak signal conditioning unit 4, the weak signal conditioning unit 4 and the voltage dividing circuit 10 are connected to the signal acquisition unit 5, and the power supply unit 6 supplies power to the whole device.
The ground loop includes the measured loop 11, the voltage jaw 12 and the current jaw 13.
The variable frequency power supply unit includes a complementary power amplifying circuit 14 and a second-order low-pass filter circuit 15.
The external unit comprises an LCD display unit 16, a key unit 17, an RS232 interface 18 and a JTAG interface 19.
The weak signal conditioning unit comprises a preamplifier circuit 20, a power frequency notch unit 21, a secondary amplifier circuit 22 and a fourth-order band-pass filter unit 23.
The signal acquisition unit comprises a low-pass filter circuit 24 and a polarity switching circuit 25.
The control unit adopts MSP430F169 single chip microcomputer chip.
As shown in fig. 2, the MSP430F169 in-chip 12-bit DAC cell is used for direct conversion into sine waves. The requirement on a hardware circuit is low, the output waveform can be flexibly controlled by changing digital quantity, and the waveform distortion is small.
As shown in fig. 3, a MAX4239 chip is used as a core of the pre-amplifier circuit. The MAX4239 has the characteristic of self-zero stabilization, and the input offset voltage is only a few mV, so that the MAX4239 is most suitable for amplifying low-frequency or direct-current weak signals. In order to avoid the influence of the overhigh feedback resistance value on the input bias voltage, the offset current and the drift thereof and the generation of operation errors, a circuit with a T-shaped network structure is designed.
As shown in fig. 4, a fourth-order bandpass filter with a variable center frequency is constructed by using an LTC1060 special filter chip. The LTC1060 chip integrates two low-noise and high-precision switched capacitor filtering units which can be independently combined, and the central frequency of a filter built by the LTC1060 chip can be changed by controlling the frequency of an external clock through a single chip microcomputer.
The working principle is as follows: the frequency conversion power supply is adopted to send an excitation signal, and the frequency of the excitation signal is intelligently selected after the frequency of the grounding grid interference current is detected so as to avoid a strong interference frequency band, so that the aims of improving the anti-interference capability and the measurement precision of the system are fulfilled. Simultaneously, this novel two jaw measurement techniques that have combined have realized ground resistance's on-line measuring. The jaw part consists of a voltage jaw and a current jaw which are respectively a voltage coil and a current coil. During measurement, the voltage coil generates a known constant low-frequency alternating voltage, and a voltage is generated in a tested grounding lead loop through electromagnetic induction, the voltage can generate a current I in a grounding loop, and the current is converted into a current by the current receiving coil. The excitation voltage and the induced current are sent to the data acquisition module after signal conditioning. After voltage and current signals are collected, wavelet transform multi-resolution characteristics are used for carrying out digital filtering on the sampled signals, then the DFT technology is adopted for extracting in-phase components of the voltage and the current, and the resistance value of the grounding resistor is obtained after the in-phase components are processed by the single chip microcomputer.
Claims (7)
1. The utility model provides a ground resistance measuring device suitable for surge monitoring of transformer substation uses, includes ground circuit, variable frequency power supply unit, external unit, weak signal conditioning unit, signal acquisition unit, power supply unit, on/off control circuit, self-checking circuit, the control unit and bleeder circuit, its characterized in that: the frequency conversion power supply unit is respectively connected with the grounding loop and the voltage division circuit, the frequency conversion power supply unit, the external unit, the signal acquisition unit, the power on/off control circuit and the self-checking circuit are respectively connected with the control unit, the grounding loop is connected with the weak signal conditioning unit, the weak signal conditioning unit and the voltage division circuit are both connected with the signal acquisition unit, and the power supply unit supplies power to the whole device.
2. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the grounding loop comprises a tested loop, a voltage jaw and a current jaw.
3. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the variable frequency power supply unit comprises a complementary power amplifying circuit and a second-order low-pass filter circuit.
4. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the external unit comprises an LCD display unit, a key unit, an RS232 interface and a JTAG interface.
5. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the weak signal conditioning unit comprises a preamplifier circuit, a power frequency trap unit, a secondary amplifier circuit and a fourth-order band-pass filter unit.
6. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the signal acquisition unit comprises a low-pass filter circuit and a polarity conversion circuit.
7. The ground resistance measuring device suitable for substation surge monitoring of claim 1, characterized in that: the control unit adopts an MSP430F169 singlechip chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020241328.3U CN211928030U (en) | 2020-03-03 | 2020-03-03 | Ground resistance measuring device suitable for transformer substation's surge monitoring is used |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020241328.3U CN211928030U (en) | 2020-03-03 | 2020-03-03 | Ground resistance measuring device suitable for transformer substation's surge monitoring is used |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211928030U true CN211928030U (en) | 2020-11-13 |
Family
ID=73346168
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020241328.3U Active CN211928030U (en) | 2020-03-03 | 2020-03-03 | Ground resistance measuring device suitable for transformer substation's surge monitoring is used |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211928030U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117590084A (en) * | 2023-11-14 | 2024-02-23 | 国网江苏省电力有限公司南通市海门区供电分公司 | Device and method for measuring grounding resistance of transmission line tower |
-
2020
- 2020-03-03 CN CN202020241328.3U patent/CN211928030U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117590084A (en) * | 2023-11-14 | 2024-02-23 | 国网江苏省电力有限公司南通市海门区供电分公司 | Device and method for measuring grounding resistance of transmission line tower |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101493485B (en) | On-line monitoring system for capacitive equipment dielectric loss angle | |
| CN201569705U (en) | Monitoring device for ground wire resistance and current of distribution transformer | |
| CN204425298U (en) | A kind of faint AC signal amplitude lock-in amplifier | |
| CN201576056U (en) | Grounding resistance online detector based on TMS320LF2407A | |
| CN105093140A (en) | Transformer remanence detection and demagnetization method and device | |
| CN201429673Y (en) | Integral test system for crystal oscillator | |
| CN206756755U (en) | A kind of stress wave signal conditioning device | |
| CN105785135A (en) | Frequency conversion ground impedometer | |
| CN101839931A (en) | Alternating current signal measurement device, system and method | |
| CN114552584B (en) | Topology identification system and identification method for low-voltage power grid area | |
| CN211785733U (en) | Three-phase multifunctional metering system | |
| CN211928030U (en) | Ground resistance measuring device suitable for transformer substation's surge monitoring is used | |
| CN108680843A (en) | A kind of method for detection of partial discharge of switch cabinet based on Radio Transmission Technology | |
| CN204439712U (en) | Based on the hollow coil current transformer of Novel DC negative feedback integrator | |
| CN103713243B (en) | 10V inside switch cabinet discharging detection device based on electromagnetic antenna receiving array | |
| CN206710499U (en) | A kind of current data harvester based on Rogowski coil | |
| CN102969718A (en) | Current sampling method for active power filter | |
| CN215375595U (en) | Ground net ground resistance tester that tests is carried out through inside and outside power of instrument | |
| CN2543071Y (en) | Power factor and frequency combined transmitter | |
| CN107544043B (en) | Multifunctional digital helium optical pump magnetometer test probe | |
| CN213023527U (en) | On-spot calibration equipment of portable arrester on-line monitoring device | |
| CN211234567U (en) | Low-power consumption electromagnetic flowmeter for intelligently adjusting excitation pulse | |
| CN203705594U (en) | 10V switch cabinet internal discharge detector based on electromagnetic wave antenna reception array | |
| CN207908593U (en) | A kind of power quality detection system | |
| CN103063928B (en) | System for testing earth grounding resistance, and digital coherent detection method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |