CN115356537A - High-voltage line insulation resistance measuring method, measuring circuit and tester - Google Patents
High-voltage line insulation resistance measuring method, measuring circuit and tester Download PDFInfo
- Publication number
- CN115356537A CN115356537A CN202210932641.5A CN202210932641A CN115356537A CN 115356537 A CN115356537 A CN 115356537A CN 202210932641 A CN202210932641 A CN 202210932641A CN 115356537 A CN115356537 A CN 115356537A
- Authority
- CN
- China
- Prior art keywords
- voltage
- voltage line
- insulation resistance
- current
- module
- 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
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/025—Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
Abstract
Provided are a high-voltage line insulation resistance measuring method, a measuring circuit and a tester. The invention provides a method for measuring insulation resistance of a high-voltage line, which comprises the following steps: transmitting high-voltage pulse to the high-voltage line by adopting alternating current equipment, and if no loop exists in the detection, the high-voltage line has insulation resistance; if a loop is detected and the voltage signal and the current signal have time difference, the high-voltage line has an insulation resistor; if a loop is detected and the voltage signal and the current signal have no time difference, the insulation resistance of the high-voltage line is damaged. The invention provides a high-voltage line insulation resistance measuring instrument, which comprises a pulse transmitting device, a control module and a lithium battery pack, wherein the pulse transmitting device is connected with the control module; the pulse transmitting device transmits high-voltage pulses to the high-voltage line, and the control module judges whether the high-voltage line has the high-voltage metering device or not and detects the insulation resistance parameters. The high-voltage line insulation resistance measuring instrument can switch high-voltage pulses with different frequencies in a high-frequency current mode, judge the insulation resistance on a loop line and accurately eliminate the condition that the high-voltage measuring instrument is on a high-voltage loop.
Description
Technical Field
The invention relates to the field of high-voltage line maintenance, in particular to a high-voltage line insulation resistance measuring method, a measuring circuit and a tester.
Background
At present, the situation that insulation performance of a high-voltage loop is reduced or even branches are hit to a line can exist along with the operation process time, in order to detect whether the insulation performance accords with the safety specification of a power grid, a high-voltage megger is adopted to measure the insulation resistance on the high-voltage line, and whether the insulation performance accords with the requirement is judged according to the size of the insulation resistance.
However, with the layout of the existing smart grid, a high-voltage meter such as a CT or PT meter is often connected to a high-voltage loop line, and the inside of the meter is actually a winding, one end of the meter is connected to a high-voltage line, and the other end of the meter is connected to a ground line. However, when the insulation resistance is measured, the current generated by the megger flows through the ground through the winding, so that the insulation resistance detected by the megger is misjudged.
Disclosure of Invention
In order to solve the problems, the invention provides a high-voltage line insulation resistance measuring circuit and a tester, and the technical scheme is as follows:
a method for measuring insulation resistance of a high-voltage line comprises the following steps: adopting alternating current equipment to transmit high-voltage pulse to the high-voltage line, and if no loop is detected, the high-voltage line has an insulation resistor; if the loop is detected and the voltage signal and the current signal have time difference, the high-voltage line has an insulation resistor; if a loop is detected and the voltage signal and the current signal have no time difference, the insulation resistance of the high-voltage line is damaged.
A high-voltage line insulation resistance measuring instrument comprises a pulse transmitting device, a control module and a lithium battery pack; the pulse transmitting device transmits high-voltage pulses to the high-voltage line, and the control module judges whether the high-voltage line has a high-voltage metering device and detects insulation resistance parameters; the lithium battery pack provides energy for the pulse transmitting device and the control module.
Further, the pulse transmitting device transmits the frequency of 0Hz to 10Khz.
Further, the pulse transmitting device comprises a boosting module, a current enabling module and a safety module; the boosting module converts the voltage of the lithium battery pack into high-voltage electric energy; the current enabling module generates a sequence of high-frequency currents; the safety module prevents the tester from being subjected to lightning and electric shock hazards.
Further, the control module comprises an MCU (microprogrammed control unit) and a high-frequency detection module, the MCU controls the pulse transmitting device, and the high-frequency detection module detects and identifies the current fed back by the high-voltage line, judges whether the meter is grounded and detects the size of the insulation resistor.
Furthermore, the boosting module adopts a push-pull structure, and utilizes a small push-pull circuit to boost the battery voltage to high-voltage direct-current electric energy.
Furthermore, the current enabling module comprises a solid-state relay, one end of the solid-state relay is connected with the boosting module, and the other end of the solid-state relay is connected with the high-frequency detection module through a high-voltage line.
Furthermore, the safety module comprises a freewheeling diode D1, a current limiting resistor R1, a piezoresistor R2 and a current sensor, wherein the freewheeling diode D1, the current limiting resistor R1, the piezoresistor R2 and the current sensor are electrically connected, and the current sensor collects current on a high-voltage line in real time.
A high-voltage line insulation resistance measuring circuit comprises a transformer, a high-voltage line, a high-voltage meter and the high-voltage line insulation resistance measuring instrument; the transformer is connected with a high-voltage line, one end of the high-voltage insulation resistance instrument is connected with the high-voltage line, and the other end of the high-voltage insulation resistance instrument is connected with the ground.
Compared with the prior art, the beneficial effects are:
according to the method for measuring the insulation resistance of the high-voltage line, whether the insulation resistance of the high-voltage line is intact or not is judged by adopting the alternating current pulse, and the condition that other equipment influences a measurement conclusion on a high-voltage loop can be accurately eliminated by detecting the time difference between the voltage signal and the current signal.
The high-voltage line insulation resistance measuring instrument can switch high-voltage pulses with different frequencies in a high-frequency current mode, judge the insulation resistance on a loop line and accurately eliminate the condition that the high-voltage measuring instrument is on a high-voltage loop. The high-voltage line insulation resistance measuring instrument can monitor the ground wire safety in real time, ensure that workers can assist a line of workers to quickly detect the safety of the high-voltage line, and improve the working efficiency.
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 only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram a of prior art measurement of insulation resistance of a high voltage line;
FIG. 2 is a schematic diagram b of the prior art for measuring insulation resistance of a high voltage line;
FIG. 3 is a schematic diagram c of the prior art for measuring insulation resistance of a high voltage line;
FIG. 4 is a schematic diagram a of the insulation resistance measurement method of a high voltage line according to the present invention;
FIG. 5 is a schematic diagram b of the insulation resistance measurement method of a high voltage line according to the present invention;
FIG. 6 is a schematic diagram c illustrating the method for measuring insulation resistance of a high voltage line according to the present invention;
FIG. 7 is a circuit for measuring insulation resistance of a high voltage line according to the present invention;
FIG. 8 is a schematic view of a high-voltage line insulation resistance measuring instrument according to the present invention;
FIG. 9 is a schematic diagram of the operation of the boost module of the high-voltage line insulation resistance measuring instrument according to the present invention;
FIG. 10 is a schematic diagram of the operation of the current enable module of the high voltage line insulation resistance measuring apparatus according to the present invention;
fig. 11 is a schematic diagram of the operation of the safety module of the high-voltage line insulation resistance measuring instrument according to the present invention.
Detailed Description
The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.
The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure of the present disclosure. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be carried into practice or applied to various other specific embodiments, and various modifications and changes may be made in the details within the description and the drawings without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.
A method for measuring insulation resistance of a high-voltage line comprises the following steps: transmitting high-voltage pulse to the high-voltage line by adopting alternating current equipment, and if no loop exists in the detection, the high-voltage line has insulation resistance; if the loop is detected and the voltage signal and the current signal have time difference, the high-voltage line has an insulation resistor; if the loop is detected and the voltage signal and the current signal have no time difference, the insulation resistance of the high-voltage line is damaged. The insulation resistance refers to the insulation layer of the high-voltage line. Insulation resistance damage refers to the breakdown of the insulation layer.
The prior art measures insulation resistance using ac equipment such as an ac power source or an ac motor. As shown in fig. 1, the high voltage line is not connected to other devices, the high voltage line is not grounded, and if the insulation resistance of the high voltage line is intact, the measurement result is no loop.
As shown in fig. 2, the high voltage line is not connected to other devices, and if the insulation resistance of the high voltage line is damaged, the measurement result is that a loop exists.
As shown in fig. 3, the high voltage line is connected to an inductive or capacitive device, such as a high voltage meter, e.g., a CT or PT meter, and the measurement result is a loop regardless of whether the insulation resistance of the line is intact.
Therefore, the prior art direct current measurement method cannot judge whether the insulation resistance is damaged.
The embodiment provides a method for measuring insulation resistance of a high-voltage line, which is characterized in that alternating current equipment is adopted to transmit high-voltage pulses to the high-voltage line, and if a time difference between a voltage signal and a current signal of a loop is detected, the high-voltage line has insulation resistance. If no time difference exists between the voltage signal and the current signal of the loop, the signal returns through the inductive or capacitive equipment, and the insulation resistance of the high-voltage line is damaged.
As shown in fig. 4, the high-voltage line is not connected to other devices, the high-voltage line is not grounded, and if the insulation resistance of the high-voltage line is intact, the measurement result is no loop.
As shown in fig. 5, the high voltage line is not connected to other devices, and if the insulation resistance of the high voltage line is damaged, the measurement result is that a loop exists.
As shown in fig. 6, if the high voltage line is connected to an inductive or capacitive device, such as a high voltage meter, e.g., a CT or PT. The test result shows that a loop exists. When a time difference exists between the current phase and the voltage phase, the insulation resistance of the high-voltage line is intact, otherwise, the insulation resistance of the high-voltage line is damaged.
As shown in fig. 7, a high-voltage line insulation resistance measuring circuit includes a transformer, a high-voltage line, a high-voltage meter and a high-voltage line insulation resistance measuring instrument; the transformer is connected with a high-voltage line, one end of the high-voltage insulation resistance instrument is connected with three phases of the high-voltage line, and the other end of the high-voltage insulation resistance instrument is connected with the ground; one end of the high-voltage meter is connected with a high-voltage line, and the other end of the high-voltage meter is connected with the ground. The high-voltage line insulation resistance measuring instrument sends a sequence of high-frequency pulses with the frequency from 0Hz to 10Khz, and the control module can judge whether a high-voltage metering device exists on a loop according to an intelligent algorithm and give insulation resistance parameters.
A high-voltage line insulation resistance measuring instrument comprises a pulse transmitting device, a control module and a lithium battery pack; the pulse transmitting device transmits high-voltage pulses to the high-voltage line, and the control module judges whether the high-voltage line has a high-voltage metering device and detects insulation resistance parameters; in order to adapt to scenes such as power-off maintenance, the high-capacity lithium battery pack integrated in the tester provides energy for the pulse transmitting device and the control module.
In the present embodiment, the pulse transmitting means transmits at a frequency of 0Hz to 10Khz.
As shown in fig. 8, the pulse transmitting apparatus includes a boosting module, a current enabling module, and a safety module; the voltage of the lithium battery pack is converted into high-voltage electric energy by the boosting module; the current enabling module generates a sequence of high-frequency currents; the safety module prevents the tester from being exposed to thunder and electric shock hazards.
As shown in fig. 8-11, the control module includes an MCU computing unit and a high frequency detection module, and the MCU computing unit is electrically connected to the high frequency detection module. MCU calculating unit control pulse emitter, high frequency detection module detects the discernment with the electric current that high voltage line fed back, judges whether have the strapping table ground connection to detect insulation resistance size.
As shown in fig. 9, the boost module adopts a push-pull structure, and utilizes a small push-pull circuit to boost the battery voltage to the high-voltage dc power. The power supply design adopts a push-pull topology, and can convert the battery voltage into direct current voltage of more than 300V. The power supply design adopts a push-pull topology, and can convert the battery voltage into direct current voltage of more than 300V. The voltage of the battery passes through the windings Np1 and Np2 and flows to the switching tubes Q1 and Q2, the secondary winding Ns of the transformer obtains electricity, direct current is obtained through diode rectification, the direct current is subjected to sampling feedback of the MCU calculation unit, algorithm calculation is carried out, PWM is output to control the switching tubes Q1 and Q2 to be switched on and switched off, and corresponding voltage is obtained.
As shown in fig. 10, the current enabling module includes a solid-state relay, one end of the solid-state relay is connected to the voltage boosting module, and the other end of the solid-state relay is connected to the high-frequency detection module through a high-voltage line. The MCU computing unit utilizes the enabling end to enable the solid-state relay to be continuously switched on and off, and the purpose of emitting a series of high-frequency currents is achieved.
As shown in fig. 11, the safety module includes a freewheeling diode D1, a current limiting resistor R1, a voltage dependent resistor R2, and a current sensor, the freewheeling diode D1, the current limiting resistor R1, the voltage dependent resistor R2, and the current sensor are electrically connected to each other, and the current sensor collects current on the high-voltage line in real time. Once overcurrent happens, the MCU immediately cuts off the current enabling unit.
The high-voltage line insulation resistance measuring instrument can switch high-voltage pulses with different frequencies in a high-frequency current mode, judge the insulation resistance on a loop line, accurately eliminate the condition that the high-voltage measuring instrument exists on a high-voltage loop, and accurately identify which type of grounding mode is. The high-voltage line insulation resistance measuring instrument can monitor the ground wire safety in real time, ensure that workers can assist a line of workers to quickly detect the safety of the high-voltage line, and improve the working efficiency.
In the present invention, unless otherwise expressly stated or limited, the first feature may be "on" the second feature in direct contact with the second feature, or the first and second features may be in indirect contact via an intermediate. "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The above description is for illustrative purposes only and is not intended to limit the present invention, and any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention should be included within the scope of the present invention as defined by the appended claims.
Claims (9)
1. A method for measuring insulation resistance of a high-voltage line is characterized by comprising the following steps:
adopting alternating current equipment to transmit high-voltage pulse to the high-voltage line, and if no loop is detected, the high-voltage line has an insulation resistor; if the loop is detected and the voltage signal and the current signal have time difference, the high-voltage line has an insulation resistor; if a loop is detected and the voltage signal and the current signal have no time difference, the insulation resistance of the high-voltage line is damaged.
2. A high-voltage line insulation resistance measuring instrument is characterized by comprising a pulse transmitting device, a control module and a lithium battery pack; the pulse transmitting device transmits high-voltage pulses to the high-voltage line, and the control module judges whether the high-voltage line has a high-voltage metering device and detects insulation resistance parameters; the lithium battery pack provides energy for the pulse transmitting device and the control module.
3. The apparatus according to claim 2, wherein the pulse emitting device emits a pulse having a frequency of 0Hz to 10Khz.
4. The high-voltage line insulation resistance measuring instrument according to claim 2, wherein the pulse transmitting device comprises a boosting module, a current enabling module and a safety module; the boosting module converts the voltage of the lithium battery pack into high-voltage electric energy; the current enabling module generates a sequence of high-frequency currents; the safety module prevents the tester from being exposed to thunder and electric shock hazards.
5. The high-voltage line insulation resistance measuring instrument according to claim 2, wherein the control module comprises an MCU (microprogrammed control unit) and a high-frequency detection module, the MCU controls the pulse transmitting device, and the high-frequency detection module detects and identifies the current fed back by the high-voltage line, judges whether meter grounding exists and detects the size of the insulation resistance.
6. The high-voltage line insulation resistance measuring instrument according to claim 4, wherein the boosting module adopts a push-pull structure, and a small push-pull circuit is used for boosting the battery voltage to high-voltage direct-current electric energy.
7. The instrument according to claim 4, wherein the current enabling module comprises a solid-state relay, one end of the solid-state relay is connected to the voltage boosting module, and the other end of the solid-state relay is connected to the high-frequency detecting module through a high-voltage line.
8. The instrument for measuring insulation resistance of high voltage line according to claim 4, wherein the safety module comprises a freewheeling diode D1, a current limiting resistor R1, a voltage dependent resistor R2 and a current sensor, the freewheeling diode D1, the current limiting resistor R1, the voltage dependent resistor R2 and the current sensor are electrically connected, and the current sensor collects current on the high voltage line in real time.
9. A high voltage line insulation resistance measuring circuit, comprising a transformer, a high voltage line, a high voltage meter and a high voltage line insulation resistance measuring instrument according to any one of claims 2 to 8; the transformer is connected with a high-voltage line, one end of the high-voltage insulation resistance instrument is connected with the high-voltage line, and the other end of the high-voltage insulation resistance instrument is connected with the ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210932641.5A CN115356537A (en) | 2022-08-04 | 2022-08-04 | High-voltage line insulation resistance measuring method, measuring circuit and tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210932641.5A CN115356537A (en) | 2022-08-04 | 2022-08-04 | High-voltage line insulation resistance measuring method, measuring circuit and tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115356537A true CN115356537A (en) | 2022-11-18 |
Family
ID=84032888
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210932641.5A Pending CN115356537A (en) | 2022-08-04 | 2022-08-04 | High-voltage line insulation resistance measuring method, measuring circuit and tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115356537A (en) |
-
2022
- 2022-08-04 CN CN202210932641.5A patent/CN115356537A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2542494C2 (en) | Device and method for detection of ground short-circuit | |
| US8924170B2 (en) | Method and system for detecting a failed rectifier in an AC/DC converter | |
| RU2611598C2 (en) | Medical imaging device | |
| CN106882667A (en) | The safety device of elevator device | |
| CN109116123B (en) | Transformer grounding resistance measurement system and method using photovoltaic inverter | |
| CN101509955A (en) | Automatic test system of dc circuit breaker characteristic parameter | |
| CN111044871A (en) | Integrated 10kV zinc oxide arrester test system and method | |
| Sritrai et al. | Low voltage series arc fault detection using rogowski coil | |
| CN214122364U (en) | Three-in-one comprehensive detector for electrical equipment | |
| CN104901574A (en) | Bridge circuit and short circuit protection method thereof | |
| CN115356537A (en) | High-voltage line insulation resistance measuring method, measuring circuit and tester | |
| CN201266833Y (en) | On-line pre-detection circuit and device for protection of shorted to earth of frequency changer output end | |
| CN218272608U (en) | Measuring and protecting device for electric switch and electric switch | |
| CN110148925A (en) | For the guard method of motor ground fault and frequency converter in frequency converter | |
| CN111579920A (en) | Fault detection device and method | |
| CN107132387B (en) | Signal source device | |
| CN112067865A (en) | Current source device and direct current fill electric pile check gauge calibrating installation | |
| CN112415418A (en) | Electromagnetic stirring variable frequency power supply fault detection circuit | |
| CN102288828A (en) | Digital high-voltage multifunctional insulator detection device | |
| CN210982552U (en) | Partial discharge PRPD atlas alternating current coupling circuit | |
| CN216285498U (en) | Zero-crossing pulse counting phase-loss detection circuit | |
| CN113281556B (en) | Charged display device and charged measurement system | |
| CN214703860U (en) | Detection device is put in frequency conversion resonance oscillation wave cable office | |
| CN203287429U (en) | Microwave detection circuit used for magnetrons | |
| CN113985238B (en) | Control circuit for withstand voltage and ESD test, withstand voltage test method and endoscope |
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 |