CN115963353A - Single-phase circuit fault point tracking method and system - Google Patents
Single-phase circuit fault point tracking method and system Download PDFInfo
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- CN115963353A CN115963353A CN202211582588.7A CN202211582588A CN115963353A CN 115963353 A CN115963353 A CN 115963353A CN 202211582588 A CN202211582588 A CN 202211582588A CN 115963353 A CN115963353 A CN 115963353A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
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Abstract
The invention relates to the technical field of single-phase circuit fault location, in particular to a method and a system for tracking a fault point of a single-phase circuit. When the application is used for measuring the distributed capacitance, a rectangular oscillation wave is generated and output to the measured capacitance, the voltage value is measured by the integrating circuit, and the capacitance value is confirmed according to the voltage value. According to the fact that distributed capacitance exists between the conducting wires and the distributed capacitance value is related to the length of the conducting wires, namely the distance to the fault can be measured through measuring the distributed capacitance, and therefore the position of the fault can be determined. This application can bury or bury circuit fault point by accurate inquiry wall, reduces operating cost, has accurate location circuit fault point, test broken line length function.
Description
Technical Field
The invention relates to the technical field of single-phase circuit fault location, in particular to a method and a system for tracking a fault point of a single-phase circuit.
Background
Before entering the user, the household power supply is divided into three-phase four-wire system according to current-carrying conductors. I.e., three phase lines, electrical symbols: A. b, C. Color of the cable: yellow, green, red, a zero line, electrical symbols: n, cable color: and blue. And the color of the other grounding wire cable is as follows: yellow green. The single phase is any phase line and a zero line in the three phases. It is often called "live" or "neutral". Usually 220V, 50Hz ac. The single-phase voltage is also named as phase voltage in electrical engineering. The power supply specification of the household appliances mostly adopts single-phase alternating current, namely 220V and 50Hz alternating current formed by adapting a phase line and a zero line. Therefore, the single-phase circuit is widely applied to various public places, offices, office buildings, markets, resident families and the like.
For make the wiring have the aesthetic property or because of water and electricity transformation, cause most single-phase power cord to bury in the wall or carry out the wiring through underground cable, cause the difficult electric wire damage condition of observing. When the electric wire breaks down, if the electric wire can not be processed in time, personal electric shock and electric fire accidents are caused, great hidden dangers are brought to personal property safety, and a large number of fires caused by household appliances are caused.
Therefore, when the single-phase circuit is operated and a condition that the line is buried in a wall or an underground cable is met, it is difficult to determine the fault point. Therefore, a simple device for determining the position of a circuit fault point is needed.
Disclosure of Invention
The invention provides a single-phase circuit fault point tracking method for calculating the distance between a detection point and a fault point and realizing the positioning of the fault point, which comprises the following steps:
s101, applying voltage Vi to the single-phase circuit by the high-frequency pulse circuit, and sending square wave pulses to the single-phase circuit;
s102, when the square wave pulse falls, acquiring voltage Vo at a fault point;
s103, calculating a distributed capacitor C based on the voltage Vi and the voltage Vo;
and S104, calculating the length L of the cable based on the distributed capacitance C, and determining the distance to the fault point based on the length L of the cable.
Preferably, step S101 further comprises:
sending a signal with continuously increased high frequency to the single-phase circuit;
when the single-phase circuit resonates, calculating a resonant frequency value of the single-phase circuit;
the frequency value of the control square wave pulse is lower than the value of the resonance frequency.
Preferably, step S102 further comprises:
the high-frequency pulse circuit generates a rectangular oscillation wave and outputs the rectangular oscillation wave to the tested single-phase circuit;
observing the frequency condition of the parasitic oscillation of the rising edge of the rectangular oscillation wave;
when the rectangular oscillation wave is input to the position of the fault point, the square wave pulse is decreased.
Preferably, step S103 further includes a distributed capacitance calculation formula:
Vo＝-1/R1C∫Vidt；
C＝-1/R1Vo∫Vidt；
r1 is the resistance value of R1.
Preferably, step S104 further includes: cable length L calculation formula
C＝ε*S/d；
Epsilon is the medium coefficient;
s is the area;
d is the distance between the line and the ground;
wherein S = D × L;
d is the diameter of the cable core wire;
l is the cable length;
therefore C = ∈ D L/D;
L＝C*d/ε*D。
the invention also provides a single-phase circuit fault point tracking system, comprising: a single chip microcomputer;
the singlechip is connected with a high-frequency pulse circuit;
the single chip microcomputer applies voltage Vi to the single-phase circuit through the high-frequency pulse circuit and sends square wave pulses to the single-phase circuit;
when the single chip microcomputer detects that the square wave pulse falls down, acquiring voltage Vo at a fault point;
the singlechip calculates a distributed capacitor C based on the pulse voltage Vi and the output voltage Vo, and calculates the cable length L through the distributed capacitor C.
Preferably, the device further comprises a resonant frequency test circuit;
the single chip microcomputer is connected with the resonant frequency test circuit, and sends a signal with continuously increased frequency to the single-phase circuit through the resonant frequency test circuit;
when the single chip microcomputer detects that resonance occurs, the resonance frequency value of the single-phase circuit is calculated.
Preferably, an integrating circuit is further included;
the integrating circuit comprises an operational amplifier;
the reverse input end of the operational amplifier is connected with one end of a resistor R1, and the other end of the resistor R1 applies voltage Vi;
the reverse input end of the operational amplifier is also connected with one end of the distributed capacitor C;
the other end of the distributed capacitor C is connected with the output end of the operational amplifier;
the same-direction input end of the operational amplifier is connected with one end of the resistor R2, and the other end of the resistor R2 is grounded.
Preferably, the terminal further comprises a first terminal and a second terminal;
the first terminal and the second terminal are both connected with the high-frequency pulse circuit;
the first terminal is connected with a live wire of the single-phase circuit;
the second terminal is connected with the zero line of the single-phase circuit.
Preferably, the device also comprises a direct current power supply;
the direct current power supply is connected with the single chip microcomputer and used for supplying power to the system;
the single chip microcomputer is also connected with a display screen, and the voltage Vi, the voltage Vo and the cable length L are displayed through the display screen;
the first terminal and the second terminal are both crane-mouth clamps.
According to the technical scheme, the invention has the following advantages:
the invention respectively clamps the live wire and the zero wire of the single-phase circuit through the first terminal and the second terminal to determine the detection point. According to the invention, through the first terminal and the second terminal, the resonance point of the single-phase circuit is measured through the resonance frequency testing circuit, the frequency for inducing the single-phase circuit to resonate is obtained based on the resonance point, and when the high-frequency pulse circuit sends the square wave pulse to the single-phase circuit, the square wave pulse is lower than the frequency, the single-phase circuit is prevented from being induced to resonate, and the stability and the reliability of the fault point measuring process are further ensured. According to the invention, the input voltage Vi and the output voltage Vo of a fault point are detected, the distributed capacitance C is calculated through the integrating circuit, and the length value from a detection point to the fault point is determined through the distributed capacitance C according to the fact that the capacitance value is in direct proportion to the length of a lead, so that the position of the fault point is determined.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description will be briefly introduced, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
Fig. 1 is a schematic diagram of a single-phase circuit fault point tracking method.
Fig. 2 is a schematic diagram of a single-phase circuit fault point tracking system.
Fig. 3 is a schematic diagram of a single-phase circuit fault point tracking system.
Fig. 4 is an integration circuit diagram.
In the figure: the device comprises a direct current power supply 1, a resonant frequency testing circuit 2, an integrating circuit 3, a singlechip 4, a high-frequency pulse circuit 5, a display screen 6, a first terminal 7 and a second terminal 8.
Detailed Description
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 only a part of the embodiments of the present invention, and not all of the embodiments. 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.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to be limiting of the invention.
The elements and algorithm steps of the various examples described in connection with the embodiments disclosed in the single phase circuit fault point tracking system provided by the present invention may be embodied in electronic hardware, computer software, or combinations of both. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the technical solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The block diagrams shown in the figures of the single-phase circuit point-of-failure tracking system provided by the present invention are merely functional entities and do not necessarily correspond to physically separate entities. I.e. these functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor means and/or microcontroller means.
Before further detailed description of the embodiments of the present invention, terms and expressions referred to in the embodiments of the present invention are described, and the terms and expressions referred to in the embodiments of the present invention are applicable to the following explanations.
Parasitic oscillation: oscillations that do not coincide with the correct operating frequency are referred to as parasitic oscillations, i.e. oscillations originating from parasitic parameters that are independent of or not in the operating frequency range.
The invention uses resonance method to measure, and can obtain the distributed capacitance and resonance frequency: the loop inductor and the amplifying circuit form a resonant circuit, and when the circuit resonates, wL =1/wC.
Air is an insulator, has potential difference, forms capacitors with capacitance and impedance, and is distributed at all positions of the lead due to different distances and different voltage levels because of no fixed mode, so that the distributed capacitors and the distributed resistors are called. Distributed capacitance exists between two conductors that are insulated from each other by a voltage difference. Therefore, in any circuit, a distributed capacitance is formed between any two insulated conductors with a voltage difference, and only the size of the distributed capacitance is a problem. The size of the distributed capacitance depends on the geometry of the cable, the length of the cable, the insulating material, etc., and is formed by two conductors which are insulated from each other by a voltage difference.
The integrating circuit 3 is an important unit commonly used in a control and measurement system, can realize time delay, timing and generation of various waveforms by utilizing the charging and discharging processes of the integrating circuit, and is an analog signal operation circuit with wider application.
The high-frequency pulse voltage refers to transient sudden change of voltage or current, common pulse shapes include rectangular pulse, square wave pulse, sharp pulse, sawtooth pulse, step pulse, intermittent sine pulse and the like, and the pulse voltage has sudden change and discontinuity.
The present invention provides a single-phase circuit fault point tracking system, as shown in fig. 2-4, comprising: the singlechip 4 adopts an 8-bit singlechip, specifically AVR series and PIC series. The single chip microcomputer 4 is connected with a high-frequency pulse circuit 5, and is also provided with a first wiring end 7 and a second wiring end 8, and the first wiring end 7 and the second wiring end 8 are both connected with the high-frequency pulse circuit 5 and the resonant frequency test circuit 2. The first terminal 7 and the second terminal 8 both adopt crane nozzle clamps. The first terminal 7 is a red nozzle clamp, the first terminal 7 is a blue nozzle clamp, the first terminal 7 is connected with a live wire of the single-phase circuit, and the second terminal 8 is connected with a zero wire of the single-phase circuit.
The single-chip microcomputer 4 is connected with the resonant frequency test circuit 2, and sends a signal with continuously increased frequency to the single-phase circuit through the resonant frequency test circuit 2, and when the single-chip microcomputer 4 detects that resonance occurs, the resonant frequency value of the single-phase circuit is calculated. The single-chip microcomputer 4 applies voltage Vi to the single-phase circuit through the high-frequency pulse circuit 5 and sends square wave pulse to the single-phase circuit, the single-chip microcomputer 4 controls the frequency value of the square wave pulse to be lower than the resonant frequency value, and when the square wave pulse is detected to be reduced, the single-chip microcomputer 4 obtains voltage Vo at a fault point. The singlechip 4 calculates a distributed capacitance C based on the pulse voltage Vi and the output voltage Vo, and calculates the cable length L through the distributed capacitance C. The single chip microcomputer 4 is further connected with a display screen 6, and the voltage Vi, the voltage Vo and the cable length L are displayed through the display screen 6. The single chip microcomputer 4 is further connected with a direct-current power supply 1, and the direct-current power supply 1 adopts a rechargeable lithium battery and is used for supplying power to the system.
The invention also comprises an integrating circuit 3, wherein the integrating circuit 3 comprises an operational amplifier, the reverse input end of the operational amplifier is connected with one end of a resistor R1, the other end of the resistor R1 is applied with a voltage Vi, the reverse input end of the operational amplifier is also connected with one end of a distributed capacitor C, the other end of the distributed capacitor C is connected with the output end of the operational amplifier, the homodromous input end of the operational amplifier is connected with one end of a resistor R2, and the other end of the resistor R2 is grounded.
The present invention is further illustrated by the embodiments of a single phase circuit fault point tracking system and detection process. The direct current power supply 1 supplies power to the equipment, and the single chip microcomputer 4 is connected with the resonant frequency test switch, the integrating circuit 3, the high-frequency pulse circuit 5 and the display screen 6. The circuit is constructed by the singlechip 4 and controls the equipment to operate. The red nozzle clamp is connected with a circuit live wire, the blue nozzle clamp is connected with a circuit zero line, the switch of the resonant frequency testing circuit 2 is clicked, the single chip microcomputer 4 sends a group of signals with continuously increased frequency until the circuit generates a resonant phenomenon, and the resonant frequency of the circuit is calculated. The singlechip 4 controls the high-frequency pulse circuit 5 to send out high-frequency pulses, measures distributed capacitance at a certain fixed frequency which is less than the resonant frequency, observes the frequency condition of parasitic oscillation at the rising edge, and when the square wave pulses fall, the singlechip 4 controls the integrating circuit 3 to calculate the length of a fault circuit or the length of a cable and displays the length of the fault circuit through the display screen 6.
Based on the above system, the present invention further provides a method for tracking a fault point of a single-phase circuit, as shown in fig. 1, the step S101 includes: the single chip microcomputer 4 sends a signal with continuously increased high frequency to the single-phase circuit through the resonant frequency testing circuit 2, and when the single-phase circuit resonates, the resonant frequency value of the single-phase circuit is calculated. The high-frequency pulse circuit 5 applies a voltage Vi to the single-phase circuit and transmits a square wave pulse to the single-phase circuit, and the frequency value of the square wave pulse is controlled to be lower than the resonant frequency value.
The step S102 includes: the high-frequency pulse circuit 5 generates a rectangular oscillation wave, outputs the rectangular oscillation wave to the tested single-phase circuit, observes the frequency condition of the parasitic oscillation of the rising edge of the rectangular oscillation wave, and when the rectangular oscillation wave is input to the position of the fault point, the square wave pulse falls, and when the square wave pulse falls, acquires the voltage Vo at the fault point.
The step S103 comprises: the distributed capacitance C is calculated based on the voltage Vi and the voltage Vo, since the integrating circuit 3: vo = -1/R1C ≈ Vidt, so C = -1/R1Vo ═ Vidt, R1 is the resistance value of R1.
S104, calculating the length L of the cable based on the distributed capacitance C, wherein the calculation formula of the length L of the cable is as follows: c = epsilon S/d; epsilon is the medium coefficient; s is the area; d is the distance between the line and the ground; wherein S = D × L; d is the diameter of the cable core wire; l is the cable length; therefore C = ∈ D L/D; l = C D/e D, and the cable length L is determined as the distance from the detection point to the fault point.
The present invention is further illustrated by the following embodiments of the single-phase circuit fault point tracking method of the present invention. Because the circuit to be tested is a non-pure resistance circuit, the test contact is connected with the circuit, the resonant frequency test circuit 2 is started, the circuit generates a resonance phenomenon, and a resonance point of the circuit to be tested is found. Starting high-frequency pulse, controlling the pulse frequency to be lower than the resonance point of the circuit to be tested, observing the frequency condition of parasitic oscillation, and calculating the position of a fault point if the voltage drops. The measurement of the distributed capacitance is specifically as follows: generating a rectangular oscillation wave, outputting the rectangular oscillation wave to a tested capacitor, measuring a voltage value by using an integrating circuit 3, confirming a distributed capacitance value according to the voltage value, wherein the distributed capacitance value is in a direct proportion relation with the length of a wire, and finally confirming a length value of an output wire, wherein the value is the distance from a test point to a breakpoint.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A single-phase circuit fault point tracking method is characterized by comprising the following steps:
s101, applying voltage Vi to the single-phase circuit by the high-frequency pulse circuit, and sending square wave pulses to the single-phase circuit;
s102, when the square wave pulse falls, acquiring voltage Vo at a fault point;
s103, calculating a distributed capacitor C based on the voltage Vi and the voltage Vo;
and S104, calculating the length L of the cable based on the distributed capacitance C, and determining the distance to the fault point based on the length L of the cable.
2. The method for tracking the fault point of the single-phase circuit according to claim 1, wherein the step S101 further comprises:
sending a signal with continuously increased high frequency to the single-phase circuit;
when the single-phase circuit resonates, calculating a resonant frequency value of the single-phase circuit;
the frequency value of the control square wave pulse is lower than the resonant frequency value.
3. The method for tracking the fault point of the single-phase circuit according to claim 1, wherein the step S102 further comprises:
the high-frequency pulse circuit generates a rectangular oscillation wave and outputs the rectangular oscillation wave to the tested single-phase circuit;
observing the frequency condition of the parasitic oscillation of the rising edge of the rectangular oscillation wave;
when the rectangular oscillation wave is input to the position of the fault point, the square wave pulse is decreased.
4. The method for tracking the fault point of the single-phase circuit according to claim 1, wherein the step S103 further comprises a distributed capacitance calculation formula:
Vo＝-1/R1C∫Vidt；
C＝-1/R1Vo∫Vidt；
r1 is the resistance value of R1.
5. The method for tracking the fault point of the single-phase circuit according to claim 1, wherein the step S104 further comprises: cable length L calculation formula
C＝ε*S/d；
Epsilon is the medium coefficient;
s is the area;
d is the distance between the line and the ground;
wherein S = D × L;
d is the diameter of the cable core wire;
l is the cable length;
therefore C = ∈ D L/D;
L＝C*d/ε*D。
6. a single-phase circuit fault point tracking system, characterized in that the system employs the single-phase circuit fault point tracking method of any one of claims 1 to 5, comprising: a single chip microcomputer;
the singlechip is connected with a high-frequency pulse circuit;
the single chip microcomputer applies voltage Vi to the single-phase circuit through a high-frequency pulse circuit and sends square wave pulse to the single-phase circuit;
when the single chip microcomputer detects that the square wave pulse falls down, acquiring voltage Vo at a fault point;
the singlechip calculates a distributed capacitor C based on the pulse voltage Vi and the output voltage Vo, and calculates the cable length L through the distributed capacitor C.
7. The single-phase circuit point of failure tracking system of claim 6, further comprising a resonant frequency test circuit;
the single chip microcomputer is connected with the resonant frequency test circuit, and sends a signal with continuously increased frequency to the single-phase circuit through the resonant frequency test circuit;
when the single chip microcomputer detects that resonance occurs, the resonance frequency value of the single-phase circuit is calculated.
8. The single-phase circuit point of failure tracking system of claim 6, further comprising an integration circuit;
the integrating circuit comprises an operational amplifier;
the reverse input end of the operational amplifier is connected with one end of a resistor R1, and the other end of the resistor R1 applies voltage Vi;
the reverse input end of the operational amplifier is also connected with one end of the distributed capacitor C;
the other end of the distributed capacitor C is connected with the output end of the operational amplifier;
the same-direction input end of the operational amplifier is connected with one end of the resistor R2, and the other end of the resistor R2 is grounded.
9. The single-phase circuit point of failure tracking system of claim 6, further comprising a first terminal and a second terminal;
the first terminal and the second terminal are both connected with the high-frequency pulse circuit;
the first terminal is connected with a live wire of the single-phase circuit;
the second terminal is connected with the zero line of the single-phase circuit.
10. The single-phase circuit point of failure tracking system of claim 9, further comprising a dc power supply;
the direct current power supply is connected with the single chip microcomputer and used for supplying power to the system;
the single chip microcomputer is also connected with a display screen, and the voltage Vi, the voltage Vo and the cable length L are displayed through the display screen;
the first terminal and the second terminal are both crane-mouth clamps.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211582588.7A CN115963353A (en) | 2022-12-09 | 2022-12-09 | Single-phase circuit fault point tracking method and system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211582588.7A CN115963353A (en) | 2022-12-09 | 2022-12-09 | Single-phase circuit fault point tracking method and system |
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| CN115963353A true CN115963353A (en) | 2023-04-14 |
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| CN202211582588.7A Pending CN115963353A (en) | 2022-12-09 | 2022-12-09 | Single-phase circuit fault point tracking method and system |
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- 2022-12-09 CN CN202211582588.7A patent/CN115963353A/en active Pending
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