CN217717972U - Fault monitoring system - Google Patents
Fault monitoring system Download PDFInfo
- Publication number
- CN217717972U CN217717972U CN202221731248.1U CN202221731248U CN217717972U CN 217717972 U CN217717972 U CN 217717972U CN 202221731248 U CN202221731248 U CN 202221731248U CN 217717972 U CN217717972 U CN 217717972U
- Authority
- CN
- China
- Prior art keywords
- resistor
- capacitor
- operational amplifier
- inverting input
- signal
- 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 Current Or Voltage (AREA)
Abstract
The utility model discloses a fault monitoring system mainly relates to the electric power system field. The system includes a plurality of monitoring devices; the monitoring device is arranged on the power transmission line and comprises a signal processing circuit, an analog-to-digital converter and a DTU (delay tolerant unit); the signal processing circuit comprises a current sensor, a filter circuit and a signal amplifying circuit; the current sensor is arranged on the power transmission line and used for collecting electric signals on the power transmission line; the signal amplification circuit is arranged between the output end of the current sensor and the input end of the analog-to-digital converter and is used for amplifying the electric signal; the analog-to-digital converter is connected with the signal processing circuit and is used for converting the electric signal output by the signal processing circuit into a digital signal; the DTU is connected with the analog-to-digital converter and used for transmitting the digital signals to the transformer substation. Therefore, in the system, the monitoring devices are directly installed on the line body, and the plurality of monitoring devices are installed on the power transmission line, so that signals can be collected nearby, and accurate collection of electric signals on the power transmission line is realized.
Description
Technical Field
The utility model relates to an electric power system field especially relates to a fault monitoring system.
Background
The rapid development of the modern electrified society puts a very high requirement on the reliable operation of a power system, and a power transmission line is used as a main carrier for electric energy transmission in the power system, so that the safe and stable operation of the power transmission line is concerned. The power transmission line is used as a power transmission network main artery, has the characteristics of long erection distance, complex erection environment and the like, and once a fault occurs, a fault point needs to be quickly positioned to assist teams to troubleshoot the fault point and recover power supply. Currently, an in-station traveling wave distance measuring device is mainly used for detecting a line fault point.
And the in-station traveling wave distance measuring device utilizes the traveling wave signal on the secondary side tap of the mutual inductor to carry out fault distance measurement. Because the traveling wave distance measuring device in the station is large in size and must collect traveling wave signals at a place where a transformer is arranged, the traveling wave distance measuring device in the station is usually installed in a transformer substation. When the transmission line breaks down, the generated traveling wave signals are continuously attenuated along the line in the transmission process and then are greatly attenuated by devices such as a mutual inductor, and therefore the traveling wave distance measuring device in the station can not acquire the traveling wave signals easily.
Therefore, how to realize accurate acquisition of the traveling wave signal is an urgent problem to be solved by those skilled in the art.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a fault monitoring system for realize the accurate signal of telecommunication on gathering transmission line.
In order to solve the technical problem, the utility model provides a fault monitoring system, include: a plurality of monitoring devices 1;
the monitoring device 1 is arranged on a power transmission line and comprises a signal processing circuit 2, an analog-to-digital converter 8 and a DTU9;
the signal processing circuit 2 comprises a current sensor 3, a filter circuit 6 and a signal amplifying circuit 4;
the current sensor 3 is arranged on the power transmission line and used for collecting electric signals on the power transmission line;
the filter circuit 6 is connected with the current sensor 3 and is used for filtering power frequency signals in the electric signals;
the signal amplifying circuit 4 is arranged between the output end of the current sensor 3 and the input end of the analog-to-digital converter 8 and is used for amplifying an electric signal;
the analog-to-digital converter 8 is connected with the signal processing circuit 2 and is used for converting the electric signal output by the signal processing circuit 2 into a digital signal;
the DTU9 is connected to the analog-to-digital converter 8 for transmitting the digital signal to the substation.
Preferably, one signal processing circuit 2 includes a plurality of signal amplifying circuits 4.
Preferably, the signal processing circuit 2 further comprises a band-stop filter 5 connected to the current sensor 3;
the band elimination filters 5 are multiple, and each band elimination filter 5 comprises a first operational amplifier, a second operational amplifier, a third operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a second capacitor;
the first end of the first resistor is connected with the current sensor 3, and the second end of the first resistor is connected with the first end of the second resistor;
the second end of the second resistor is connected with the first end of the third resistor;
the second end of the third resistor is connected with the inverting input end of the second operational amplifier;
the non-inverting input end of the first operational amplifier is grounded, the inverting input end of the first operational amplifier is connected with the common end of the first resistor and the second resistor, the output end of the first operational amplifier is connected with the common end of the second resistor and the third resistor;
the non-inverting input end of the second operational amplifier is grounded, and the output end of the second operational amplifier is connected with the first end of the fourth resistor;
the second end of the fourth resistor is connected with the non-inverting input end of the third operational amplifier;
the first end of the fifth resistor is connected with the common end of the fourth resistor and the third operational amplifier, and the second end of the fifth resistor is grounded;
the first end of the first capacitor is connected with the common end of the current sensor 3 and the first resistor, and the second end of the first capacitor is connected with the common end of the fifth resistor and the fourth resistor;
the inverting input end of the third operational amplifier is connected with the first end of the sixth resistor, and the output end of the third operational amplifier is connected with the input end of the filter circuit 6;
the second end of the sixth resistor is connected with the common end of the second operational amplifier and the third resistor;
the first end of the second capacitor is connected with the common end of the sixth resistor and the second operational amplifier, and the second end of the second capacitor is connected with the common end of the second operational amplifier and the fourth resistor.
Preferably, the filter circuit 6 includes a fourth operational amplifier, a fifth operational amplifier, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh resistor, an eighth resistor, and a ninth resistor;
the first end of the third capacitor is connected with the output end of the band elimination filter 5, and the second end of the third capacitor is connected with the non-inverting input end of the fourth operational amplifier;
the first end of the seventh resistor is connected with the common end of the third capacitor and the fourth operational amplifier, and the second end of the seventh resistor is grounded;
the output end of the fourth operational amplifier is connected with the first end of the fourth capacitor, and the inverting input end of the fourth operational amplifier is connected with the common end of the fourth operational amplifier and the fourth capacitor;
the second end of the fourth capacitor is connected with the first end of the fifth capacitor;
the second end of the fifth capacitor is connected with the inverting input end of the fifth operational amplifier;
the first end of the eighth resistor is connected with the common end of the fourth capacitor and the fifth capacitor, and the second end of the eighth resistor is grounded;
the non-inverting input end of the fifth operational amplifier is grounded, and the output end of the fifth operational amplifier is connected with the input end of the analog-to-digital converter 8;
a first end of the sixth capacitor is connected with the inverting input end of the fifth operational amplifier, and a second end of the sixth capacitor is connected with the output end of the fifth operational amplifier;
the first end of the ninth resistor is connected with the inverting input end of the fifth operational amplifier, and the second end of the first resistor is connected with the output end of the fifth operational amplifier.
Preferably, the signal amplification circuit 4 includes a differential amplification circuit 7;
the differential amplification circuit 7 comprises a differential amplifier, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor;
the first end of the eleventh resistor is connected with the output end of the filter circuit 6, and the second end of the eleventh resistor is connected with the non-inverting input end of the differential amplifier;
the inverting input end of the differential amplifier is connected with the first end of the twelfth resistor, the power supply end of the differential amplifier is connected with an external power supply, the positive power supply end of the differential amplifier is connected with the positive electrode of the power supply, the negative power supply end of the differential amplifier is connected with the negative electrode of the power supply, and the output end of the differential amplifier is connected with the input end of the analog-to-digital converter 8;
a second end of the twelfth resistor is grounded;
the first end of the ninth capacitor is connected with the common end of the differential amplifier and the twelfth resistor, and the second end of the ninth capacitor is connected with the output end of the differential amplifier;
the first end of the thirteenth resistor is connected with the common end of the differential amplifier and the twelfth resistor, and the second end of the thirteenth resistor is connected with the output end of the differential amplifier;
the first end of the tenth capacitor is connected with the non-inverting input end of the differential amplifier, and the second end of the tenth capacitor is connected with the output end of the differential amplifier;
the first end of the fourteenth resistor is connected with the non-inverting input end of the differential amplifier, and the second end of the fourteenth resistor is connected with the output end of the differential amplifier.
Preferably, the current sensor 3 is a rogowski coil.
The utility model provides a fault monitoring system, which comprises a plurality of monitoring devices; the monitoring device is arranged on the power transmission line and comprises a signal processing circuit, an analog-to-digital converter and a DTU (delay tolerant unit); the signal processing circuit comprises a current sensor, a filter circuit and a signal amplifying circuit; the current sensor is arranged on the power transmission line and used for collecting electric signals on the power transmission line; the signal amplification circuit is arranged between the output end of the current sensor and the input end of the analog-to-digital converter and is used for amplifying the electric signal; the analog-to-digital converter is connected with the signal processing circuit and is used for converting the electric signal output by the signal processing circuit into a digital signal; the DTU is connected with the analog-to-digital converter and used for transmitting the digital signals to the transformer substation. Therefore, in the system, the monitoring device is simple in structure, small in size, capable of being directly installed on a line body, free of signal acquisition through devices such as a mutual inductor and capable of effectively preventing signals from being distorted in waveform and greatly attenuated through the mutual inductor. In addition, the system can collect signals nearby by installing a plurality of monitoring devices on the power transmission line, and can effectively avoid the problem that the signals are attenuated or even submerged due to long-distance transmission, thereby realizing the accurate collection of the electric signals on the power transmission line.
Drawings
In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the embodiments 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 it is obvious to those skilled in the art that other drawings can be obtained based on these drawings without inventive work.
Fig. 1 is a structural diagram of a fault monitoring system provided by the present invention;
fig. 2 is a circuit diagram of a band-stop filter provided by the present invention;
fig. 3 is a circuit diagram of a filter circuit provided by the present invention;
fig. 4 is a circuit diagram of a differential amplifier circuit provided by the present invention;
fig. 5 is a structural diagram of a monitoring device provided by the present invention.
The reference numbers are as follows: 1 is a monitoring device, 2 is a signal processing circuit, 3 is a current sensor, 4 is a signal amplifying circuit, 5 is a band elimination filter, 6 is a filter circuit, 7 is a differential amplifying circuit, 8 is an analog-to-digital converter, and 9 is a DTU.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, the ordinary skilled in the art can obtain all other embodiments without creative work, which all belong to the protection scope of the present invention.
The core of the utility model is to provide a fault monitoring system for realize the accurate collection of the signal of telecommunication on the power transmission line.
In order to make the technical field better understand the solution of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings and the detailed description.
Fig. 1 is a structural diagram of a fault monitoring system according to the present invention, and the fault monitoring system shown in fig. 1 is described below.
A fault monitoring system comprising: a plurality of monitoring devices 1; the monitoring device 1 is arranged on a power transmission line and comprises a signal processing circuit 2, an analog-to-digital converter 8 and a DTU9; the signal processing circuit 2 comprises a current sensor 3, a filter circuit 6 and a signal amplifying circuit 4; the current sensor 3 is arranged on the power transmission line and used for collecting electric signals on the power transmission line; the filter circuit 6 is connected with the current sensor 3 and is used for filtering power frequency signals in the electric signals; the signal amplifying circuit 4 is arranged between the output end of the current sensor 3 and the input end of the analog-to-digital converter 8 and is used for amplifying an electric signal; the analog-to-digital converter 8 is connected with the signal processing circuit 2 and is used for converting the electric signal output by the signal processing circuit 2 into a digital signal; the DTU9 is connected to the analog-to-digital converter 8 for transmitting the digital signal to the substation.
Monitoring devices 1 can adopt the mode of distributed installation, specifically, can be with hundreds of kilometers long circuit segmentation, for example, divide the district with 30 kilometers, install one set of monitoring devices 1 every 30 kilometers for one set of monitoring devices 1 is exclusively used in the signal of telecommunication on the circuit of gathering a district, and when the circuit of certain district broke down, can gather the signal of telecommunication at the circuit body, has reduced the transmission distance of the signal of telecommunication that the fault point produced by a wide margin. It can be understood that, in order to ensure the accuracy of the electrical signal acquired by the monitoring device 1, the standard distance of the section division should not be too large, and in order to ensure the economy of the system, the standard distance of the section division should not be too small, and in the specific implementation, the section division may be performed according to the actual situation, which is not limited in this embodiment.
The current sensor 3 may be a shunt, an electromagnetic current transformer, or an electronic current transformer, and the present embodiment does not limit the type of the current sensor 3. Because the load current of transmission line body is the power frequency signal, for the high frequency part in the accurate collection electric signal, need pass through the power frequency part in the filter circuit 6 filtering electric signal, can understand, for guaranteeing fully filtering power frequency signal, can set up a plurality of filter circuit 6 according to actual need.
The amplitude of the electric signal generated by the fault of the power transmission line is related to the established discharge channel, and if the discharge channel is a metallic low-resistance channel, the amplitude of the generated electric signal is usually larger; if the discharge channel is a high-resistance fault channel established by a tree barrier and the like, the amplitude of the generated electric signal is usually smaller. Therefore, in order to ensure the accuracy of the collected electric signal, after the electric signal generated by the fault point is collected by the current sensor 3, the electric signal can be amplified by the signal amplifying circuit 4, and the amplitude of the collected electric signal is increased to ensure that the electric signal is not submerged due to continuous attenuation in the transmission process. It should be noted that, in order to realize accurate acquisition of an electrical signal with a relatively low amplitude, each monitoring device 1 may be configured to include a multiple amplification circuit, and the monitoring function of a high-resistance fault is realized through multiple amplification.
In a specific implementation, when the transmission line has a fault and a fault point generates an electric signal, the monitoring device 1 closest to the fault point collects the electric signal. Specifically, the current sensor 3 collects an electric signal generated by a fault point, the electric signal is amplified through the signal amplifying circuit 4, and a power frequency part in the electric signal is filtered by the filter circuit 6; after acquiring the electrical signal processed by the signal processing circuit 2, the analog-to-digital converter 8 converts the electrical signal into a digital signal, transmits the digital signal to a Data Transfer Unit (DTU), and transmits the digital signal into a substation through a wireless network by the DTU9, thereby realizing accurate acquisition of the electrical signal generated at a fault point.
The present embodiment provides a fault monitoring system, which includes a plurality of monitoring devices; the monitoring device is arranged on the power transmission line and comprises a signal processing circuit, an analog-to-digital converter and a DTU (delay tolerant unit); the signal processing circuit comprises a current sensor, a filter circuit and a signal amplifying circuit; the current sensor is arranged on the power transmission line and used for collecting electric signals on the power transmission line; the signal amplification circuit is arranged between the output end of the current sensor and the input end of the analog-to-digital converter and is used for amplifying the electric signal; the analog-to-digital converter is connected with the signal processing circuit and is used for converting the electric signal output by the signal processing circuit into a digital signal; the DTU is connected with the analog-to-digital converter and used for transmitting the digital signals to the transformer substation. Therefore, in the system, the monitoring device is simple in structure, small in size, capable of being directly installed on a line body, free of signal acquisition through devices such as a mutual inductor and capable of effectively preventing signals from being distorted in waveform and greatly attenuated through the mutual inductor. In addition, the system can collect signals nearby by installing a plurality of monitoring devices on the power transmission line, and can effectively avoid the problem that the signals are attenuated or even submerged due to long-distance transmission, thereby realizing the accurate collection of the electric signals on the power transmission line.
On the basis of the above embodiments, in order to ensure the accuracy of the acquired electrical signals, the present embodiment provides a signal processing circuit 2 including a plurality of signal amplifying circuits 4, and the multiple amplifying circuits are used to accurately acquire the electrical signals with lower amplitudes.
Specifically, after the current sensor 3 acquires the electrical signal of the fault point, the signal amplification circuit 4 may amplify the electrical signal for the first time, so as to perform subsequent processing, and after the filtering circuit 6 filters the electrical signal, the signal amplification circuit 4 may amplify the filtered electrical signal again, so as to ensure that the amplitude of the electrical signal acquired by the analog-to-digital converter 8 is relatively large. It will be appreciated that in particular implementations, the amplification of the signal amplification circuit 4 may be adjusted by varying parameters of various components in the signal amplification circuit 4 to ensure accurate acquisition of the electrical signal at the fault point. It should be noted that, in the present embodiment, the number of the signal amplifying circuits 4 included in one signal processing circuit 2 is not limited, and may be determined according to actual situations in specific implementations.
In the embodiment, the signal processing circuit comprises a plurality of signal amplifying circuits, and the accurate acquisition of the electric signals with lower amplitude is realized through the multiple amplifying circuits, so that the acquisition range of the monitoring device on the electric signals can be effectively enlarged.
On the basis of the above embodiment, because the working environment of the alternating current transmission line is a power frequency high voltage environment, and the main interference signal of the line body is an odd harmonic signal, therefore, for filtering the interference noise existing on the line, the signal processing circuit 2 further comprises a band elimination filter 5 connected with the current sensor 3. The band-stop filters 5 are multiple, and each band-stop filter 5 comprises a first operational amplifier U1, a second operational amplifier U2, a third operational amplifier U3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1 and a second capacitor C2.
Fig. 2 is a circuit diagram of a band-stop filter according to the present invention, as shown in fig. 2, a first end of a first resistor R1 is connected to the current sensor 3, and a second end of the first resistor R1 is connected to a first end of a second resistor R2; the second end of the second resistor R2 is connected with the first end of the third resistor R3; the second end of the third resistor R3 is connected with the inverting input end of the second operational amplifier U2; the non-inverting input end of the first operational amplifier U1 is grounded, the inverting input end of the first operational amplifier U1 is connected with the common end of the first resistor R1 and the second resistor R2, and the output end of the first operational amplifier U1 is connected with the common end of the second resistor R2 and the third resistor R3; the non-inverting input end of the second operational amplifier U2 is grounded, and the output end of the second operational amplifier U2 is connected with the first end of the fourth resistor R4; the second end of the fourth resistor R4 is connected with the non-inverting input end of the third operational amplifier U3; a first end of the fifth resistor R5 is connected with the common end of the fourth resistor R4 and the third operational amplifier U3, and a second end of the fifth resistor R5 is grounded; a first end of the first capacitor C1 is connected with a common end of the current sensor 3 and the first resistor R1, and a second end of the first capacitor C1 is connected with a common end of the fifth resistor R5 and the fourth resistor R4; the inverting input end of the third operational amplifier U3 is connected with the first end of the sixth resistor R6, and the output end of the third operational amplifier U3 is connected with the input end of the filter circuit 6; a second end of the sixth resistor R6 is connected with a common end of the second operational amplifier U2 and the third resistor R3; a first end of the second capacitor C2 is connected to a common end of the sixth resistor R6 and the second operational amplifier U2, and a second end of the second capacitor C2 is connected to a common end of the second operational amplifier U2 and the fourth resistor R4.
In a specific implementation, the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 may be ADA4807-2ARMZ manufactured by Adnao semiconductor technologies Inc. (ADI). In fig. 2, the first operational amplifier U1 is an inverting amplifier, and the filter circuit 6 composed of the fifth resistor R5 and the first capacitor C1 is used as an inverting negative feedback of the first operational amplifier U1; the second operational amplifier U2, a sixth resistor R6 and a second capacitor C2 which are arranged at the periphery jointly form an integrating and filtering circuit 6; the third operational amplifier U3 is a voltage follower and is used for increasing the driving capability, and the third operational amplifier U3 and a sixth resistor R6 form reverse negative feedback of the second operational amplifier U2; the second resistor R2 is used for maintaining the voltage drop of the inverting input terminal and the output terminal of the first operational amplifier U1, and the first resistor R1, the third resistor R3 and the fourth resistor R4 play a role of current limiting, so as to prevent the signal amplification circuit 4 from excessively amplifying the electrical signal. In this embodiment, the target frequency signal filtered by the band-elimination filter 5 is an interference signal of the power transmission line, and the interference signal is intercepted by the band-elimination filter 5 to avoid the interference signal from interfering with the fault diagnosis and analysis. It can be understood that, in the specific implementation, the frequency band of the signal filtered by the band-stop filter 5 can be adjusted by adjusting parameters of each device in the band-stop filter 5, so as to ensure that the signal filtered by the band-stop filter 5 is an interference signal.
It should be noted that, in order to ensure the filtering effect of the band-stop filter 5, a plurality of band-stop filters 5 may be provided, and the filtering effect is enhanced by providing a plurality of band-stop filters 5, so as to ensure that the electrical signal acquired by the analog-to-digital converter 8 is an effective signal after the interference signal is filtered.
The signal processing circuit further comprises a band elimination filter connected with the current sensor, and interference signals in the acquired electric signals can be effectively filtered by the band elimination filter, so that the interference signals are prevented from interfering with fault diagnosis and analysis.
On the basis of the foregoing embodiment, in order to ensure the filtering effect of the filter circuit 6, the filter circuit 6 of the present embodiment includes a fourth operational amplifier U4, a fifth operational amplifier U5, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9.
Fig. 3 is a circuit diagram of a filter circuit provided by the present invention, as shown in fig. 3, a first end of a third capacitor C3 is connected to an output end of the band-stop filter 5, and a second end of the third capacitor C3 is connected to a non-inverting input end of a fourth operational amplifier U4; a first end of the seventh resistor R7 is connected with the common end of the third capacitor C3 and the fourth operational amplifier U4, and a second end of the seventh resistor R7 is grounded; the output end of the fourth operational amplifier U4 is connected with the first end of the fourth capacitor C4, and the inverting input end of the fourth operational amplifier U4 is connected with the common end of the fourth operational amplifier U4 and the fourth capacitor C4; the second end of the fourth capacitor C4 is connected with the first end of the fifth capacitor C5; the second end of the fifth capacitor C5 is connected with the inverting input end of the fifth operational amplifier U5; a first end of the eighth resistor R8 is connected with a common end of the fourth capacitor C4 and the fifth capacitor C5, and a second end of the eighth resistor R8 is grounded; the non-inverting input end of the fifth operational amplifier U5 is grounded, and the output end of the fifth operational amplifier U5 is connected with the input end of the analog-to-digital converter 8; a first end of the sixth capacitor C6 is connected with the inverting input end of the fifth operational amplifier U5, and a second end of the sixth capacitor C6 is connected with the output end of the fifth operational amplifier U5; a first end of the ninth resistor R9 is connected to the inverting input terminal of the fifth operational amplifier U5, and a second end of the first resistor R1 is connected to the output terminal of the fifth operational amplifier U5.
In a specific implementation, the fourth operational amplifier U4 and the fifth operational amplifier U5 may be ADA4807-2ARMZ manufactured by ADI. In fig. 3, the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 suppress low-frequency signals by high-frequency signals, and the seventh resistor R7 and the eighth resistor R8 are bleed resistors, where the seventh resistor R7 is used to bleed the voltage of the third capacitor C3, and the eighth resistor R8 is used to bleed the voltage of the fourth capacitor C4; the fourth operational amplifier U4 is a voltage follower to increase the driving capability, and the fifth operational amplifier U5, the sixth capacitor C6 and the ninth resistor R9 form a high-pass filter circuit 6 to filter the power frequency part in the electrical signal. It can be understood that, in specific implementation, the frequency band range filtered by the filter circuit 6 can be adjusted by adjusting parameters of each device in the filter circuit 6, so as to ensure that the filtered signal is a power frequency part in the acquired electrical signal.
The filter circuit includes a fourth operational amplifier, a fifth operational amplifier, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh resistor, an eighth resistor, and a ninth resistor, the driving capability of the signal is increased by a voltage follower formed by the fourth operational amplifier, and the power frequency part in the electrical signal is filtered by the filter circuit formed by the fifth operational amplifier, the sixth capacitor, and the ninth resistor, so as to ensure that the power frequency signal is effectively filtered.
On the basis of the above-described embodiment, in order to eliminate the zero point drift, the present embodiment provides that the signal amplification circuit 4 includes the differential amplification circuit 7. The differential amplification circuit 7 includes a differential amplifier U7, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor, a twelfth capacitor, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a fourteenth resistor R14.
Fig. 4 is a circuit diagram of a differential amplifier circuit provided by the present invention, as shown in fig. 4, a first end of an eleventh resistor R11 is connected to an output end of the filter circuit 6, and a second end of the eleventh resistor R11 is connected to a non-inverting input end of the differential amplifier U7; the inverting input end of the differential amplifier U7 is connected with the first end of the twelfth resistor R12, the power supply end of the differential amplifier U7 is connected with an external power supply, the positive power supply end of the differential amplifier U7 is connected with the positive electrode of the power supply, the negative power supply end of the differential amplifier U7 is connected with the negative electrode of the power supply, and the output end of the differential amplifier U7 is connected with the input end of the analog-to-digital converter 8; the second end of the twelfth resistor R12 is grounded; a first end of a ninth capacitor C9 is connected with a common end of the differential amplifier U7 and the twelfth resistor R12, and a second end of the ninth capacitor C9 is connected with an output end of the differential amplifier U7; a first end of the thirteenth resistor R13 is connected with a common end of the differential amplifier U7 and the twelfth resistor R12, and a second end of the thirteenth resistor R13 is connected with an output end of the differential amplifier U7; a first end of a tenth capacitor C10 is connected with the non-inverting input end of the differential amplifier U7, and a second end of the tenth capacitor C10 is connected with the output end of the differential amplifier U7; a first end of the fourteenth resistor R14 is connected to the non-inverting input terminal of the differential amplifier U7, and a second end of the fourteenth resistor R14 is connected to the output terminal of the differential amplifier U7.
In a specific implementation, the differential amplifier U7 may employ AD8137YRZ manufactured by ADI. In fig. 4, the AD _ VCM end of the differential amplifier U7 is connected to an external power supply, the differential amplifier U7 has two output ends, and both output ends are connected to the input end of the analog-to-digital converter 8, the electrical signal acquired by the analog-to-digital converter 8 is actually a difference between the electrical signals output by the two output ends of the differential amplifier U7, the ninth capacitor C9 and the thirteenth resistor R13 form the high-pass filter circuit 6 at the inverting input end of the differential amplifier U7, the tenth capacitor C10 and the fourteenth resistor R14 form the high-pass filter circuit 6 at the non-inverting input end of the differential amplifier U7, and the eleventh capacitor and the twelfth capacitor are decoupling capacitors for reducing noise of the power supply and increasing stability of the differential amplifier U7. In an implementation, the differential amplifier circuit 7 shown in fig. 4 can stabilize a static operating point by using the symmetry of the non-inverting input terminal and the negative feedback effect, and suppress a common mode signal by amplifying a differential mode signal to ensure high fidelity of an electrical signal. It can be understood that, in order to increase the driving capability of the circuit, a voltage follower may be connected to the non-inverting input terminal of the differential amplifier U7, as shown in fig. 4, and the voltage follower is composed of the operational amplifier U6, the resistor R10, the capacitor C7 and the capacitor C8 to follow the output of the filter circuit 6.
Fig. 5 is a structure diagram of a monitoring device provided by the utility model, as shown in fig. 5, current sensor 3, signal amplification circuit 4, band elimination filter 5, filter circuit 6 and difference amplifier circuit 7 constitute signal processing circuit 2, signal processing circuit 2 can gather the signal of telecommunication that the fault point produced through current sensor 3, preliminary amplification is carried out via signal amplification circuit 4, and through the interference signal on the band elimination filter 5 filtering transmission line, power frequency part in the signal of telecommunication is filtered by filter circuit 6 again, the signal of telecommunication after will handling after difference amplifier circuit 7 eliminates the zero drift at last is transmitted to analog-to-digital converter 8; after the analog-to-digital converter 8 collects the electric signal, the electric signal is converted into a digital signal and is transmitted to the DTU9, and the digital signal is transmitted to a transformer substation through the DTU9 through a wireless network so as to carry out fault analysis.
The signal amplification circuit comprises the differential amplification circuit, zero drift is eliminated and the static working point is stabilized by the differential amplification circuit, so that the height of the collected electric signal is guaranteed.
On the basis of the above embodiment, the current sensor 3 is provided as a rogowski coil in the present embodiment for the convenience of mounting.
The rogowski coil is an alternating current sensor 3, which is mainly used for measuring high frequency current, and in the present embodiment, is mainly used for measuring high frequency parts in an electrical signal generated by a fault point. In addition, the Rogowski coil is small in size and light in weight, can be directly sleeved on a power transmission line to measure alternating current, and is convenient to install and detach on the line body.
The current sensor is arranged in the embodiment and is a Rogowski coil, and the Rogowski coil is small in size and light in weight, so that the Rogowski coil can be directly sleeved on a power transmission line to measure current, and the Rogowski coil is convenient to install and disassemble.
It is right above the utility model provides a fault monitoring system introduces in detail. The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.
It should also be noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
Claims (6)
1. A fault monitoring system, comprising: a plurality of monitoring devices (1);
the monitoring device (1) is arranged on the power transmission line and comprises a signal processing circuit (2), an analog-to-digital converter (8) and a DTU (data transfer unit) (9);
the signal processing circuit (2) comprises a current sensor (3), a filter circuit (6) and a signal amplifying circuit (4);
the current sensor (3) is arranged on the power transmission line and used for collecting electric signals on the power transmission line;
the filter circuit (6) is connected with the current sensor (3) and is used for filtering power frequency signals in the electric signals;
the signal amplification circuit (4) is arranged between the output end of the current sensor (3) and the input end of the analog-to-digital converter (8) and is used for amplifying the electric signal;
the analog-to-digital converter (8) is connected with the signal processing circuit (2) and is used for converting the electric signals output by the signal processing circuit (2) into digital signals;
the DTU (9) is connected with the analog-to-digital converter (8) and is used for transmitting the digital signals to a transformer substation.
2. Fault monitoring system according to claim 1, characterized in that one of said signal processing circuits (2) comprises a plurality of said signal amplification circuits (4).
3. Fault monitoring system according to claim 1, characterized in that the signal processing circuit (2) further comprises a band stop filter (5) connected to the current sensor (3);
the band elimination filters (5) are multiple, and each band elimination filter (5) comprises a first operational amplifier, a second operational amplifier, a third operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor and a second capacitor;
the first end of the first resistor is connected with the current sensor (3), and the second end of the first resistor is connected with the first end of the second resistor;
the second end of the second resistor is connected with the first end of the third resistor;
a second end of the third resistor is connected with an inverting input end of the second operational amplifier;
the non-inverting input end of the first operational amplifier is grounded, the inverting input end of the first operational amplifier is connected with the common end of the first resistor and the second resistor, and the output end of the first operational amplifier is connected with the common end of the second resistor and the third resistor;
the non-inverting input end of the second operational amplifier is grounded, and the output end of the second operational amplifier is connected with the first end of the fourth resistor;
a second end of the fourth resistor is connected with a non-inverting input end of the third operational amplifier;
a first end of the fifth resistor is connected with a common end of the fourth resistor and the third operational amplifier, and a second end of the fifth resistor is grounded;
a first end of the first capacitor is connected with a common end of the current sensor (3) and the first resistor, and a second end of the first capacitor is connected with a common end of the fifth resistor and the fourth resistor;
the inverting input end of the third operational amplifier is connected with the first end of the sixth resistor, and the output end of the third operational amplifier is connected with the input end of the filter circuit (6);
a second end of the sixth resistor is connected with a common end of the second operational amplifier and the third resistor;
and a first end of the second capacitor is connected with a common end of the sixth resistor and the second operational amplifier, and a second end of the second capacitor is connected with a common end of the second operational amplifier and the fourth resistor.
4. A fault monitoring system according to claim 3, characterized in that the filter circuit (6) comprises a fourth operational amplifier, a fifth operational amplifier, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh resistor, an eighth resistor and a ninth resistor;
the first end of the third capacitor is connected with the output end of the band-stop filter (5), and the second end of the third capacitor is connected with the non-inverting input end of the fourth operational amplifier;
a first end of the seventh resistor is connected with a common end of the third capacitor and the fourth operational amplifier, and a second end of the seventh resistor is grounded;
the output end of the fourth operational amplifier is connected with the first end of the fourth capacitor, and the inverting input end of the fourth operational amplifier is connected with the common end of the fourth operational amplifier and the fourth capacitor;
the second end of the fourth capacitor is connected with the first end of the fifth capacitor;
a second end of the fifth capacitor is connected with an inverting input end of the fifth operational amplifier;
a first end of the eighth resistor is connected with a common end of the fourth capacitor and the fifth capacitor, and a second end of the eighth resistor is grounded;
the non-inverting input end of the fifth operational amplifier is grounded, and the output end of the fifth operational amplifier is connected with the input end of the analog-to-digital converter (8);
a first end of the sixth capacitor is connected with an inverting input end of the fifth operational amplifier, and a second end of the sixth capacitor is connected with an output end of the fifth operational amplifier;
and a first end of the ninth resistor is connected with an inverting input end of the fifth operational amplifier, and a second end of the first resistor is connected with an output end of the fifth operational amplifier.
5. Fault monitoring system according to claim 1, characterized in that the signal amplification circuit (4) comprises a differential amplification circuit (7);
the differential amplification circuit (7) comprises a differential amplifier, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fourteenth resistor;
a first end of the eleventh resistor is connected with an output end of the filter circuit (6), and a second end of the eleventh resistor is connected with a non-inverting input end of the differential amplifier;
the inverting input end of the differential amplifier is connected with the first end of the twelfth resistor, the power supply end of the differential amplifier is connected with an external power supply, the positive power supply end of the differential amplifier is connected with the positive electrode of the power supply, the negative power supply end of the differential amplifier is connected with the negative electrode of the power supply, and the output end of the differential amplifier is connected with the input end of the analog-to-digital converter (8);
a second end of the twelfth resistor is grounded;
a first end of the ninth capacitor is connected with a common end of the differential amplifier and the twelfth resistor, and a second end of the ninth capacitor is connected with an output end of the differential amplifier;
a first end of the thirteenth resistor is connected with a common end of the differential amplifier and the twelfth resistor, and a second end of the thirteenth resistor is connected with an output end of the differential amplifier;
a first end of the tenth capacitor is connected with a non-inverting input end of the differential amplifier, and a second end of the tenth capacitor is connected with an output end of the differential amplifier;
a first end of the fourteenth resistor is connected to the non-inverting input terminal of the differential amplifier, and a second end of the fourteenth resistor is connected to the output terminal of the differential amplifier.
6. Fault monitoring system according to claim 1, characterized in that the current sensor (3) is a rogowski coil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221731248.1U CN217717972U (en) | 2022-07-06 | 2022-07-06 | Fault monitoring system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221731248.1U CN217717972U (en) | 2022-07-06 | 2022-07-06 | Fault monitoring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217717972U true CN217717972U (en) | 2022-11-01 |
Family
ID=83778146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221731248.1U Active CN217717972U (en) | 2022-07-06 | 2022-07-06 | Fault monitoring system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217717972U (en) |
-
2022
- 2022-07-06 CN CN202221731248.1U patent/CN217717972U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111384781B (en) | 5G communication base station electric power operation monitoring system | |
| CN111398662A (en) | Current sensor for power transmission line | |
| CN217717972U (en) | Fault monitoring system | |
| CN109932619B (en) | Secondary signal collector of electronic sensor of power distribution network | |
| CN111504868B (en) | Building construction raise dust monitoring system based on big data | |
| CN113253027A (en) | Converter measuring circuit of electromagnetic water meter | |
| CN209894959U (en) | High-common-mode-interference-resistance small-signal isolation sampling conditioning circuit of electronic transformer | |
| CN115267417B (en) | Accurate positioning method for power transmission line faults and power transmission line traveling wave measuring device | |
| CN114598358B (en) | Power line carrier communication system | |
| CN215003927U (en) | Noise signal sensing device based on intelligent distribution transformation visual management and control platform | |
| CN212229025U (en) | Current sensor for power transmission line | |
| CN216350893U (en) | Capacitor voltage transformer | |
| CN212622889U (en) | Join in marriage on-line monitoring device of net elbow type cable joint state | |
| CN211127565U (en) | Special power filter for EMI alternating current medical equipment | |
| CN109067375A (en) | A kind of PT secondary side neutral point multipoint earthing sensed current signal amplifying circuit | |
| CN213239257U (en) | Passive wireless temperature sensor | |
| CN210514514U (en) | Small signal acquisition circuit applied to power distribution terminal | |
| CN210667162U (en) | Power utilization safety monitoring system | |
| CN209946250U (en) | Three-phase current acquisition circuit based on compensation circuit and acquisition device | |
| CN111308201A (en) | Distributed wave recording system integrating small-current grounding line selection function | |
| CN220603562U (en) | Hidden danger discharge signal acquisition and filter circuit for cable collector circuit | |
| CN218956674U (en) | Traveling wave current sampling circuit for pole switch and pole switch | |
| CN212324075U (en) | Photovoltaic module carrier wave receiving band-pass flat type filter circuit | |
| CN206041946U (en) | Noise muffler | |
| CN218068139U (en) | Power grid frequency detection circuit and device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |