CN117517750A - Zinc oxide lightning arrester resistive current extraction device and method based on current comparator - Google Patents

Zinc oxide lightning arrester resistive current extraction device and method based on current comparator Download PDF

Info

Publication number
CN117517750A
CN117517750A CN202311488094.7A CN202311488094A CN117517750A CN 117517750 A CN117517750 A CN 117517750A CN 202311488094 A CN202311488094 A CN 202311488094A CN 117517750 A CN117517750 A CN 117517750A
Authority
CN
China
Prior art keywords
current
winding
current comparator
zinc oxide
channel
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
Application number
CN202311488094.7A
Other languages
Chinese (zh)
Inventor
韩永森
于辰风
陈杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Harbin University of Science and Technology
Original Assignee
Harbin University of Science and Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Harbin University of Science and Technology filed Critical Harbin University of Science and Technology
Priority to CN202311488094.7A priority Critical patent/CN117517750A/en
Publication of CN117517750A publication Critical patent/CN117517750A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/52—Testing for short-circuits, leakage current or ground faults

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Thermistors And Varistors (AREA)

Abstract

The invention discloses a device and a method for extracting resistive current of a zinc oxide arrester based on a current comparator, wherein the device comprises an alternating-current high-voltage power supply, a zinc oxide arrester sample equivalent model, a current comparator component, a standard capacitor, a sampling resistor, a high-voltage probe and an oscilloscope; the current comparator component comprises a current comparator, a primary side first winding, a primary side second winding and a secondary side winding, wherein the primary side first winding, the primary side second winding and the secondary side winding are arranged on two sides of the current comparator; the zinc oxide arrester sample equivalent model is connected with the primary side first winding, and the standard capacitor is connected with the primary side second winding; the high-voltage probe is used for collecting a first channel voltage signal, the sampling resistor is connected with the secondary winding, and a second channel voltage signal is collected. The method is simple and convenient to operate, and the resistive component of the leakage current of the zinc oxide arrester sample can be extracted only by adjusting the number of turns of the primary side first winding and the primary side second winding of the current comparator, so that the voltage signals of the first channel and the second channel observed on the oscilloscope are in the same phase.

Description

Zinc oxide lightning arrester resistive current extraction device and method based on current comparator
Technical Field
The invention relates to the technical field of electrical testing, in particular to a zinc oxide arrester resistive current extraction device and method based on a current comparator.
Background
Zinc oxide arresters are important electrical devices that protect electrical equipment from atmospheric and operational overvoltages. The lightning arrester not only bears the effect of power frequency alternating voltage for a long time, but also can be influenced by moisture, pollution and overvoltage impact, so that the aging of the lightning arrester is accelerated, even the lightning arrester is exploded, and the safe and stable operation of a power system is seriously threatened. Therefore, the method for monitoring and diagnosing the insulation state of the lightning arrester is one of the important points of the research on the overvoltage protection of the power system. It is well known that the arrester leakage current consists of a resistive component and a capacitive component. When the lightning arrester ages, the third harmonic will appear in the resistive electric quantity in the leakage current of the lightning arrester, and therefore, a common method for monitoring and diagnosing the state of the lightning arrester is to measure the resistive component of the leakage current of the lightning arrester. However, the capacitive component of the leakage current is typically more than 2 orders of magnitude higher than the resistive component, which presents great difficulty in accurately extracting the resistive current component.
The capacitive current compensation method is one of the methods for extracting resistive current components of the lightning arrester. According to the method, the applied voltages at two ends of the lightning arrester are phase-shifted by 90 degrees through the phase shifter to form capacitive compensation current, and then the capacitive component in the leakage current of the lightning arrester is compensated by the capacitive compensation current, so that the resistive component is obtained. However, because the phase shifter itself has a phase shift, it is difficult to truly shift the applied voltage across the arrester by 90 °. In other words, this method cannot fully compensate for the capacitive component of the arrester leakage current, which will increase the measurement error of the resistive component. In view of the disadvantages, there are many improved capacitive current compensation methods, such as phase shift compensation for the third harmonic of the capacitive current, but these improved methods are complex in principle and have low extraction efficiency of the resistive current of the lightning arrester.
Disclosure of Invention
The invention aims to provide a device and a method for extracting resistive current of a zinc oxide arrester based on a current comparator, which are based on compensating capacitive components and can accurately and effectively extract the resistive components from leakage current of the zinc oxide arrester.
In order to achieve the above object, the present invention provides the following solutions:
in one aspect, the present invention provides a resistive current extraction device for a zinc oxide arrester based on a current comparator, including: the system comprises an alternating-current high-voltage power supply, a zinc oxide arrester sample equivalent model, a current comparator component, a standard capacitor, a sampling resistor, a high-voltage probe and an oscilloscope;
the zinc oxide lightning arrester sample equivalent model comprises equivalent resistors and equivalent capacitors which are arranged in parallel;
the current comparator component comprises a current comparator, a current comparator primary side first winding, a current comparator primary side second winding and a current comparator secondary side winding, wherein the current comparator primary side first winding and the current comparator primary side second winding are connected in series, and a series connection point is connected to the grounding end of the alternating current high-voltage power supply;
the high-voltage end of the alternating-current high-voltage power supply is respectively connected with the input end of the zinc oxide arrester sample equivalent model, the standard capacitor and the high-voltage probe;
the output end of the zinc oxide arrester sample equivalent model is connected with the primary side first winding of the current comparator, and the output end of the standard capacitor is connected with the primary side second winding of the current comparator;
one end of the sampling resistor is grounded, the other end of the sampling resistor is connected to the oscilloscope, and two ends of the secondary winding of the current comparator are respectively connected to two ends of the sampling resistor;
the high voltage probe is connected to an oscilloscope.
Further, the oscilloscope is provided with a first channel and a second channel, the output end of the high-voltage probe is connected to the first channel, and the sampling resistor is connected to the second channel.
The invention further provides a zinc oxide arrester resistive current extraction method based on a current comparator, which is applied to the zinc oxide arrester resistive current extraction device based on the current comparator, and comprises the following steps:
ac high voltage generated at ac high voltage power supplyUnder the action, the leakage current flowing through the equivalent model of the zinc oxide lightning arrester sample is +.>By resistive component->And capacitive component->Composition, leakage current->The current flowing into the primary side first winding of the current comparator and the current generated by the reference capacitor>Flowing into a primary side second winding of the current comparator;
ac high voltageA first channel voltage signal reduced in equal proportion is formed by a high-voltage probe>A first channel into an oscilloscope;
current flowing through secondary winding of current comparatorGenerating a second channel voltage signal +.>A second channel into the oscilloscope;
the secondary winding of the current comparator has the following relation with the primary first winding of the current comparator of the primary winding and the primary second winding of the current comparator:
wherein N is 1 For the number of turns, N, of the primary first winding of the current comparator 2 For the number of turns, N, of the primary second winding of the current comparator 0 Turns of secondary winding of the current comparator;
by adjusting the number of turns N 1 、N 2 Such that:
the first channel voltage signal of the oscilloscopeAnd a second channel voltage signal->In phase, the resistive component of the leakage current flowing through the zinc oxide arrester sample is:
wherein R is 0 Is the resistance of the sampling resistor.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects: according to the zinc oxide arrester resistive current extraction device and method based on the current comparator, through the current comparator and ampere turn balance principle, the current flowing through the standard capacitor and the magnetic flux generated by the capacitive component of the zinc oxide arrester sample leakage current in the primary winding of the current comparator are mutually counteracted, so that the resistive component of the zinc oxide arrester sample leakage current is accurately obtained at the secondary side of the current comparator; the method is simple and convenient to operate, and the resistive component of the leakage current of the zinc oxide arrester sample can be extracted only by adjusting the number of turns of the primary side first winding and the primary side second winding of the current comparator, so that the voltage signals of the first channel and the second channel observed on the oscilloscope are in the same phase.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic circuit diagram of a resistive current extraction device of a zinc oxide arrester based on a current comparator;
fig. 2 is a phasor diagram of a current comparator-based method for extracting resistive current of a zinc oxide arrester according to the present invention;
reference numerals illustrate: 1-an alternating-current high-voltage power supply; 2-zinc oxide lightning arrester sample equivalent model; 21-equivalent resistance; 22-equivalent capacitance; a 3-current comparator component; 31-primary first winding of current comparator; 32-a primary second winding of the current comparator; 33-secondary winding of current comparator; 4-a standard capacitor; 5-sampling resistance; 6-a high-pressure probe; 7-oscilloscopes; 71-a first channel; 72-second channel.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide a device and a method for extracting resistive current of a zinc oxide arrester based on a current comparator, which can realize extraction of resistive components of leakage current of a zinc oxide arrester sample by only adjusting the number of turns of a primary first winding and a primary second winding of the current comparator so that voltage signals of a first channel and a second channel observed on an oscilloscope are in phase.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
As shown in fig. 1, the resistive current extraction device of a zinc oxide arrester based on a current comparator provided by the invention comprises: an alternating-current high-voltage power supply 1, a zinc oxide arrester sample equivalent model 2, a current comparator component 3, a standard capacitor 4, a sampling resistor 5, a high-voltage probe 6 and an oscilloscope 7;
the zinc oxide arrester sample equivalent model 2 comprises an equivalent resistor 21 and an equivalent capacitor 22 which are arranged in parallel;
the current comparator assembly 3 comprises a current comparator, a current comparator primary side first winding 31, a current comparator primary side second winding 32 and a current comparator secondary side winding 33 which are arranged on two sides of the current comparator, wherein the current comparator primary side first winding 31 and the current comparator primary side second winding 32 are connected in series, and a series connection point is connected to the grounding end of the alternating current high voltage power supply 1;
the high-voltage end of the alternating-current high-voltage power supply 1 is respectively connected with the zinc oxide arrester sample equivalent model 2, the standard capacitor 4 and the input end of the high-voltage probe 6;
the output end of the zinc oxide arrester sample equivalent model 2 is connected with the primary side first winding 31 of the current comparator, and the output end of the standard capacitor 4 is connected with the primary side second winding 32 of the current comparator;
one end of the sampling resistor 5 is grounded, the other end of the sampling resistor is connected to the oscilloscope 7, and two ends of the secondary winding 33 of the current comparator are respectively connected to two ends of the sampling resistor 5;
the high voltage probe 6 is connected to an oscilloscope 7.
Wherein the oscilloscope 7 is provided with a first channel 71 and a second channel 72, the output end of the high-voltage probe 6 is connected to the first channel 71, and the sampling resistor 5 is connected to the second channel 72.
As shown in fig. 1-2, the method for extracting the resistive current of the zinc oxide lightning arrester based on the current comparator provided by the invention comprises the following steps:
ac high voltage generated at ac high voltage power supply 1Under the action, the leakage current flowing through the zinc oxide arrester sample equivalent model 2 is +.>By resistive component->And capacitive component->Composition, leakage current->The current flowing into the primary side first winding 31 of the current comparator, the current generated by the reference capacitor 4 +.>Flowing into the primary second winding 32 of the current comparator;
ac high voltageA first channel voltage signal reduced in an equal proportion is formed by a high-voltage probe 6>A first channel 71 into oscilloscope 7;
current flowing through secondary winding 33 of current comparatorGenerating a second channel voltage signal +_ on the sampling resistor 5>Into a second channel 72 of the oscilloscope 7;
the secondary winding 33 of the current comparator has the following relationship with the primary first winding 31 of the current comparator and the primary second winding 32 of the current comparator:
wherein N is 1 For the number of turns, N, of the primary first winding 31 of the current comparator 2 N is the number of turns of the current comparator primary second winding 32 0 Turns for the current comparator secondary winding 33;
by adjusting the number of turns N 1 、N 2 Such that:
the first channel voltage signal of oscilloscope 7And a second channel voltage signal->In phase, the resistive component of the leakage current flowing through the zinc oxide arrester sample is:
wherein R is 0 Is the resistance of the sampling resistor 5.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims (3)

1. A zinc oxide arrester resistive current extraction device based on a current comparator, comprising: an alternating-current high-voltage power supply (1), a zinc oxide lightning arrester sample equivalent model (2), a current comparator component (3), a standard capacitor (4), a sampling resistor (5), a high-voltage probe (6) and an oscilloscope (7);
the zinc oxide lightning arrester sample equivalent model (2) comprises an equivalent resistor (21) and an equivalent capacitor (22) which are arranged in parallel;
the current comparator assembly (3) comprises a current comparator, a current comparator primary side first winding (31), a current comparator primary side second winding (32) and a current comparator secondary side winding (33), wherein the current comparator primary side first winding (31) and the current comparator primary side second winding (32) are connected in series, and a series connection point is connected to the grounding end of the alternating current high-voltage power supply (1);
the high-voltage end of the alternating-current high-voltage power supply (1) is respectively connected with the input ends of the zinc oxide arrester sample equivalent model (2), the standard capacitor (4) and the high-voltage probe (6);
the output end of the zinc oxide arrester sample equivalent model (2) is connected with the primary side first winding (31) of the current comparator, and the output end of the standard capacitor (4) is connected with the primary side second winding (32) of the current comparator;
one end of the sampling resistor (5) is grounded, the other end of the sampling resistor is connected to the oscilloscope (7), and two ends of the secondary winding (33) of the current comparator are respectively connected to two ends of the sampling resistor (5);
the high voltage probe (6) is connected to an oscilloscope (7).
2. The current comparator based zinc oxide arrester resistive current extraction device according to claim 1, characterized in that the oscilloscope (7) is provided with a first channel (71) and a second channel (72), the output of the high voltage probe (6) is connected to the first channel (71), the sampling resistor (5) is connected to the second channel (72).
3. A method for extracting resistive current of a zinc oxide arrester based on a current comparator, which is applied to the device for extracting resistive current of a zinc oxide arrester based on a current comparator as claimed in any one of claims 1-2, and is characterized by comprising the following steps:
AC high voltage generated at AC high voltage power supply (1)Under the action, the leakage current flowing through the zinc oxide lightning arrester sample equivalent model (2)>By resistive component->And capacitive component->Composition, leakage current->The current flowing into the primary side first winding (31) of the current comparator and the current generated by the reference capacitor (4)>Flowing into a primary second winding (32) of the current comparator;
ac high voltageA first channel voltage signal ++scaled down is formed by a high voltage probe (6)>A first channel (71) into the oscilloscope (7);
current flowing through secondary winding (33) of current comparatorGenerating a second channel voltage signal +_ on a sampling resistor (5)>A second channel (72) into the oscilloscope (7);
the secondary winding (33) of the current comparator has the following relation with the primary first winding (31) of the current comparator of the primary winding and the primary second winding (32) of the current comparator:
wherein N is 1 Is the number of turns, N, of the primary first winding (31) of the current comparator 2 For the number of turns, N, of the primary second winding (32) of the current comparator 0 Turns for the secondary winding (33) of the current comparator;
by adjusting the number of turns N 1 、N 2 Such that:
the first channel voltage signal of the oscilloscope (7)And a second channel voltage signal->In phase, the resistive component of the leakage current flowing through the zinc oxide arrester sample is:
wherein R is 0 Is the resistance of the sampling resistor (5).
CN202311488094.7A 2023-11-09 2023-11-09 Zinc oxide lightning arrester resistive current extraction device and method based on current comparator Pending CN117517750A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311488094.7A CN117517750A (en) 2023-11-09 2023-11-09 Zinc oxide lightning arrester resistive current extraction device and method based on current comparator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311488094.7A CN117517750A (en) 2023-11-09 2023-11-09 Zinc oxide lightning arrester resistive current extraction device and method based on current comparator

Publications (1)

Publication Number Publication Date
CN117517750A true CN117517750A (en) 2024-02-06

Family

ID=89750709

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311488094.7A Pending CN117517750A (en) 2023-11-09 2023-11-09 Zinc oxide lightning arrester resistive current extraction device and method based on current comparator

Country Status (1)

Country Link
CN (1) CN117517750A (en)

Similar Documents

Publication Publication Date Title
JP2018532249A (en) Capacitor-type instrument transformer for transient overvoltage monitoring system
CN102445583B (en) Voltage signal monitoring device of power energy quality monitoring device and circuit as well as application thereof
CN112305352A (en) Voltage reconstruction MOA resistive current testing method based on in-phase capacitive equipment
Limcharoen et al. Rogowski coil with an active integrator for measurement of switching impulse current
CN104569598A (en) Nondestructive detection circuit and method for insulation resistance of high-voltage battery energy storage system
CN106526356A (en) Metal oxide lightning arrester live-line detection validity test system
CN107167698B (en) Lightning arrester leakage current live-line test device and method
CN104375031B (en) On-line measurement device for power supply system surge protection device insulation resistance
CN111220883A (en) Method and device for detecting insulation defect of basin-type insulator based on steep wave voltage
CN117517750A (en) Zinc oxide lightning arrester resistive current extraction device and method based on current comparator
Banjanin et al. Experimental registration and numerical simulation of the transient overvoltages caused by single phase intermittent arc earth fault in 35 kV network with isolated neutral
Redfern et al. The application of distribution system current transformers for high frequency transient based protection
Heavey et al. RMS measuring principles in the application of protective relaying and metering
CN203054063U (en) Input voltage measuring circuit for high-voltage frequency converter
CN107703409B (en) Current measurement circuit for insulating core transformer type high-voltage power supply
CN112305348A (en) Method for quickly testing resistive current of reconstructed MOA (metal oxide arrester) by considering in-phase capacitive equipment
Zhang et al. Simulation Study of Capacitor Voltage Transformer based on Overvoltage Measurement Technology
Li et al. Development and Application of Leakage Current Monitoring Device of MOV in UHV/EHV Series Capacitors
Shirkovets et al. Experimental investigations and calculations in 6–35 kV networks with various neutral conditions
Yuanfang et al. Experimental studies on the use of MOV in transformer windings inner protection
Wenrong et al. Study on a new method for overvoltage measurement using CVT
Yutthagowith et al. Design and construction of a rogowski's coil with compensated rc integrators for measuring impulse current
Pătru et al. Applications of Voltage Pulse Generator to Achieve Current Pulses of High Amplitude
Dedović et al. Experimental investigation of ferroresonance and mitigation measures in 35 kv isolated networks
CN118275757A (en) Voltage sensor for measuring power frequency and transient voltage

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