CN217404441U - Fault traveling wave acquisition device and system of power distribution network - Google Patents
Fault traveling wave acquisition device and system of power distribution network Download PDFInfo
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- CN217404441U CN217404441U CN202220088587.6U CN202220088587U CN217404441U CN 217404441 U CN217404441 U CN 217404441U CN 202220088587 U CN202220088587 U CN 202220088587U CN 217404441 U CN217404441 U CN 217404441U
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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 utility model discloses a fault traveling wave acquisition device of a power distribution network and a system thereof, wherein the fault traveling wave acquisition device comprises a signal adjustment unit, a high-speed sampling unit, a filtering unit, a high-precision clock unit, a FPGA and a GPRS communication unit; the high-speed sampling unit is connected to a fault traveling wave sensor of the distribution line through the signal adjusting unit and is used for measuring and collecting fault traveling waves; the input end of the traveling wave acquisition device is connected with the traveling wave sensor, and the output end transmits fault traveling wave information to the background fault positioning platform; the traveling wave sensor can be connected to the grounding wire of the shell of the transformer of the important branch of the line.
Description
Technical Field
The utility model belongs to trouble travelling wave signal draws the processing field, especially relates to a trouble travelling wave collection system and system of distribution network.
Background
In the process of generating the power grid fault, a voltage or current transient traveling wave signal is generated at the fault position and is transmitted to the two ends of the distribution line, and the speed is close to the light speed. The traveling wave positioning device calibrates the time of the transient traveling wave signal reaching the acquisition device by adopting a mode of sensing the wave head of the traveling wave signal, and measures the distance of the line fault. The power distribution network traveling wave fault positioning system can utilize fault traveling wave signals reported by the traveling wave sensors of the power distribution substations to realize high-precision fault positioning of power distribution network faults and issue accurate fault position information to related personnel.
Due to the fact that the power distribution network frame structure is complex, multiple branches of lines, numerous various power equipment (such as distribution transformers) and complex line models are achieved, fault characteristics are complex and variable, and traveling wave signals are difficult to acquire. The traveling wave fault positioning system has the advantage of high traveling wave head identification rate, and the frequency band of fault traveling waves is different from 10k to 100kHz, so that a traveling wave acquisition device with a high sampling rate is needed for accurately identifying the traveling wave head.
SUMMERY OF THE UTILITY MODEL
The utility model provides a trouble travelling wave collection system of distribution network for the travelling wave collection system of high sampling rate, must satisfy trouble travelling wave signal acquisition demand. The utility model provides a trouble travelling wave collection system is equipped with signal adjustment unit, high-speed sampling unit at the sampling end, wherein, in order to guarantee high sampling rate, be equipped with high-speed AD chip in high-speed sampling unit and carry out analog-to-digital conversion, and in order to satisfy the requirement of high-speed AD chip, before the signal gets into high-speed sampling unit, need carry out signal conversion, consequently, be equipped with the operational amplifier of difference output in the signal adjustment unit, make the output signal of signal adjustment unit is differential signal, satisfies the requirement of high-speed sampling unit, and then the trouble travelling wave collection system that this application found, its sampling advantage based on high-speed sampling unit satisfies the sampling rate demand, and inputs differential signal and can realize anti common mode interference, reinforcing signal interference killing feature.
On one hand, according to the fault traveling wave acquisition device of the power distribution network, the fault traveling wave acquisition device is connected with both the traveling wave sensor and the positioning platform, and fault traveling wave data acquired from the traveling wave sensor is transmitted to the positioning platform;
the system comprises a fault traveling wave acquisition device, a traveling wave sensor, a signal adjustment unit, a high-speed sampling unit, a positioning platform and a control unit, wherein the sampling end in the fault traveling wave acquisition device is provided with the signal adjustment unit and the high-speed sampling unit, the high-speed sampling unit is connected with the traveling wave sensor through the signal adjustment unit, and output data of the sampling end is used for data processing of the fault traveling wave acquisition device or the positioning platform;
the signal adjusting unit is internally provided with an adjusting circuit of an operational amplifier based on differential output, so that an output signal of the signal adjusting unit is a differential signal, the high-speed sampling unit is internally provided with a high-speed AD chip for analog-to-digital conversion, and the high-speed AD chip is used for differential input.
Further optionally, an AD8131 chip is disposed in the adjusting circuit in the signal adjusting unit, and a direct current bias voltage exists in signals at two ends output by the AD8131 chip.
Further optionally, the high-speed AD chip in the high-speed sampling unit is an AD9653 chip.
Further optionally, the fault traveling wave collecting device further comprises a clock unit, an FPGA and a communication unit;
the output end of the clock unit is connected with the FPGA and used for providing a time signal for the FPGA;
the FPGA is respectively connected with the high-speed acquisition unit and the communication unit and provides a clock driving signal to the high-speed acquisition unit;
the communication unit is in communication connection with the positioning platform.
Further optionally, the processing module in the fault traveling wave acquisition device further includes a filtering unit, and the filtering unit is connected to the high-speed sampling unit.
Further optionally, the filtering unit builds a wavelet filter by using a Quartus built-in IP core method based on an FPGA.
Further optionally, the fault traveling wave acquisition device is an embedded device, and the embedded device is installed in relay protection and automation equipment and shares a secondary loop of the distribution line.
Further optionally, the fault traveling wave collecting device is mounted on a line tower and provided with a solar battery.
In a second aspect, the invention provides a system based on the fault traveling wave collecting device, which comprises the fault traveling wave collecting device and a traveling wave sensor, wherein the fault traveling wave collecting device is connected with the traveling wave sensor, and the traveling wave sensor can be connected to a grounding wire of a shell of an important branch transformer of a line.
Further optionally, the system further comprises a positioning platform, and the fault traveling wave collecting device is in communication connection with the positioning platform.
Has the advantages that:
(1) the utility model discloses a trouble travelling wave collection system's sampling end is equipped with signal conditioning unit, high-speed sampling unit, wherein, in order to guarantee high sampling rate, it carries out analog-to-digital conversion to be equipped with high-speed AD chip in high-speed sampling unit, in order to satisfy the requirement of high-speed AD chip, before the signal gets into high-speed sampling unit, need carry out signal conversion, consequently, be equipped with the operational amplifier of difference output in the signal conditioning unit, make the output signal of signal conditioning unit be differential signal, satisfy the requirement of high-speed sampling unit, and then the trouble travelling wave collection system that this application founded, it is based on the sampling advantage of high-speed AD chip, can reflect the characteristic of trouble travelling wave signal more really, the design of peripheral circuit has been simplified, and have higher SNR and low-power consumption; in addition, the output signal of the signal adjusting unit is a differential signal, so that common-mode interference resistance can be realized, and the signal anti-interference capability is enhanced.
(2) The fault traveling wave acquisition device is further preferably installed in the relay protection and automation equipment in an embedded mode, a secondary circuit of the power distribution line is shared, and extra secondary circuit cost is not increased; in addition, when the solar cell is installed on a line tower and powered by the solar cell, the installation requirement of the transmission line on the provincial-crossing boundary tower can be met.
Drawings
Fig. 1 is a schematic structural diagram of an embedded low-power-consumption fault traveling wave acquisition device for a power distribution network of the present invention;
fig. 2 is a circuit diagram of an adjusting circuit in a signal adjusting unit according to the present invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. 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 application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
Example 1:
in this embodiment, a signal adjusting unit and a high-speed sampling unit are provided at a sampling end of the fault traveling wave acquisition device, and in addition, a filtering unit, a high-precision clock unit, an FPGA, and a GPRS communication unit are provided, that is, an output signal of the high-speed sampling unit is subjected to subsequent processing at the filtering unit, the high-precision clock unit, the FPGA, and the GPRS communication unit of the fault traveling wave acquisition device, it should be understood that, on the basis of the improvement concept of the sampling end of the present invention, how the fault traveling wave acquisition device performs subsequent processing on output data of the high-speed sampling unit or how a positioning platform performs subsequent data processing is not specifically restricted in this regard, and the present invention may adopt the existing technical scheme or adopt the scheme described in embodiment 1 below.
Referring to fig. 1, a fault traveling wave collecting device for a power distribution network according to this embodiment includes: the device comprises a signal adjusting unit, a high-speed sampling unit, a filtering unit, a high-precision clock unit, an FPGA and a GPRS communication unit.
The signal adjusting unit is connected with the traveling wave sensor and used for converting an input signal into a differential output signal with a voltage peak value within 2V, for example, an AD8131 chip is selected and is an operational amplifier for differential output, and a single power supply chip can be used for setting a common-mode voltage value, so that a direct-current bias voltage exists in signals at two output ends, and the differential output signal is suitable for differential input of the high-speed sampling unit. Fig. 2 shows a simulation diagram of an adjusting circuit of an operational amplifier based on differential output in a signal adjusting unit, wherein the adjusting circuit is supplied by a single power supply 5V, where R1 ═ 200 Ω, R2 ═ 200 Ω, R3 ═ 251 Ω, R4 ═ 200 Ω, R5 ═ 200 Ω, R6 ═ 62 Ω, R7 ═ 75 Ω, and R8 ═ 3000 Ω; the AD8138 is a single-ended to differential amplifier (AD8131 chip).
The adjustment circuit includes: input resistance, gain resistance, chip AD8138, feedback resistance.
One end of the input resistor is connected with an input signal, and the other end of the input resistor is connected with a resistor R4; the other end of the resistor R4 is connected with the positive input end of the chip AD 8138; one end of the resistor R3 is grounded, and the other end of the resistor R3 is connected with the reverse input end of the chip AD 8138; the resistors R3 and R4 are connected with the input resistor in series to serve as gain resistors of the adjusting circuit, and the resistance values of the resistor R4 and the input resistor after being connected in series are consistent with the resistance value of the resistor R3, so that the matching of positive feedback and negative feedback coefficient of the adjusting circuit is guaranteed; one end of the resistor R2 is connected with the reverse input end of the chip AD8138, and the other end is connected with the positive output of the chip AD 8138; resistors R1 and R2 are used as feedback resistors of the adjusting circuit; the negative output of the chip AD8138 is connected with the differential positive output end of the adjusting circuit; and the positive output of the chip AD8138 is connected with the differential negative output end of the adjusting circuit.
Wherein, further, the composition of input resistance is: the resistors R7 and R8 are connected in parallel, one end of each resistor is connected with an input signal, the other end of each resistor is grounded and serves as an adjusting resistor, and the input resistor of the adjusting circuit is adjusted to enable the wave impedance of the input traveling wave signal before entering the adjusting circuit to be matched with the input resistor of the adjusting circuit, so that the traveling wave head signal is prevented from being refracted and reflected due to mismatching of the wave impedance to generate interference on the collection of the traveling wave head; one end of the resistor R5 is connected with an input signal, and the other end is connected with the resistor R4; one end of the resistor R6 is connected with R4, and the other end is grounded; the resistors R7 and R8 are connected in parallel, then are connected in series with the resistor R5, and then are connected in parallel with the resistor R6 to be used as the input resistor of the adjusting circuit.
Based on the adjusting circuit, signal difference can be realized, and theoretical analysis is as follows:
V 0 ＝V 0+ -V 0_
wherein, V in Is an input signal; v + 、V _ The operational amplifier comprises a positive input end and a negative input end; v 0+ 、V 0- Respectively a differential forward output and a reverse output. The resistance value of the resistor is substituted, and then the gain of the adjusting circuit is calculated as follows:
V 0 ＝0.19V in
as can be seen from the above, a sinusoidal voltage with a peak value of 5V and a frequency of 10MHz is input, and the output port waveform Vpp is 1.898V as shown in the simulation graph of the output of the adjusting circuit by looking at the output waveform of the operational amplifier signal. It should be understood that the above calculations are based on circuit basic knowledge as well as circuit structure to make inferences.
It should be understood that, in this embodiment, the voltage of ± 5V is converted to the range of 2V to meet the requirement of the high-speed sampling unit, and in other feasible embodiments, the conversion range of the voltage peak value is set according to the chip requirement of the high-speed sampling unit, so as to adjust the adjustment circuit of the operational amplifier based on the differential output, such as the resistance value of the resistor or the structure of the above logic adjustment circuit, and further apply mathematical operation and circuit theory knowledge to obtain the appropriate voltage range.
The high-speed sampling unit adopts a high-speed AD chip for analog-to-digital conversion, for example, an AD9653 chip can be selected for AD conversion, the chip is a single power supply chip, has 12-bit precision and a maximum sampling rate of 125MSPS, and is internally provided with a sampling holder and a reference voltage source, so that the design of a peripheral circuit is simplified, and the high-speed sampling unit has higher signal-to-noise ratio and low power consumption. In addition, the analog voltage input of the chip adopts differential input, so that common-mode interference is resisted, and the signal interference resistance is enhanced.
The input end of the filtering unit is connected with the high-speed sampling unit, the output end of the filtering unit is connected with the FPGA, a wavelet filter is built by adopting a Quartus built-in IP core method, a DB3 wavelet filter coefficient is calculated from matlab, then the filter coefficient is led into an IP core of an FIR filter in the Quartus II in a file form, and finally 12-bit data of AD sampling is led into the wavelet filter and is used for extracting high-frequency signals of sampling signals. It is to be understood that the filtering unit is an existing module, and the functions it implements are also realizable by existing modules, and therefore it is not overrepresented.
The high-precision clock unit inputs satellite time signals, the output end of the high-precision clock unit is connected with the FPGA, strict synchronous time signals are provided for the FPGA in a satellite communication mode, for example, a GPS + BDS dual-mode time service module with the model number of SKYALAB being SKG09F can be selected, the module sends second-level time, longitude and latitude and other information to the FPGA through a serial port, besides, the module also sends second-level pulse PPS to the FPGA, and the time below second is obtained by counting of a temperature compensation crystal oscillator.
The input end of the FPGA is connected with the output end of the filtering unit, and is simultaneously connected with the high-speed acquisition unit and the GPRS communication unit to be used as a control core of the traveling wave acquisition device, so that the high precision of the traveling wave calibration time is ensured, and the sampling rate is improved, for example, an EP4CE15F17C8 chip of the Cyclone IV series of Altera company can be selected, and the internal devices of the chip mainly comprise an LAB (logic Array Block) logic Array block, a memory module, a hardware DSP multiplier and a phase-locked loop PLL. The high-speed acquisition unit needs a clock signal given by the FPGA to drive, and when the rising edge of the clock is reached, the FPGA reads 12-bit parallel data output by an AD chip in the high-speed acquisition unit.
The GPRS communication unit is connected with the FPGA, data are transmitted to the GPRS module with the SIM card through the FPGA, finally the GPRS module is connected into a GPRS network and sends out fault traveling wave data, and the positioning platform receives fault traveling wave information uploaded by each lower computer in real time.
The working principle of the fault traveling wave acquisition device based on the structure is as follows:
before the signal enters the high-speed acquisition unit, the signal needs to be converted through the adjusting circuit, and because the input of the high-speed acquisition unit is a differential input, a differential output chip is arranged in the signal adjusting unit. For example, an AD8131 chip is selected, the chip is an operational amplifier with differential output, a single power supply chip can be used for setting a common-mode voltage value, so that signals at two output ends have a direct-current bias voltage, and the differential input of the high-speed sampling unit is suitable. Because the peak value of the analog input voltage of the high-speed sampling unit is 2V, but the actual secondary side signal of the microcomputer protection device is about +/-5V, the adjusting circuit is designed to convert the input signal, the +/-5V voltage is converted into the range of 2V to meet the requirement of the high-speed sampling unit, and the signal output of the adjusting circuit is differential output to meet the differential input of an AD chip.
Meanwhile, in order to ensure a high sampling rate, a high-speed AD chip is required to be adopted for analog-to-digital conversion, for example, an AD9653 chip is selected for AD conversion, the chip driving mode outputs a clock signal to the high-speed sampling unit through the FPGA, and when the rising edge of the clock is reached, the FPGA reads 12-bit parallel data output by the AD chip; in order to improve the effect of extracting fault high-frequency signals, a wavelet filter is constructed on the basis of an FPGA, an IP core is built in the Quartus, the method has high stability, the filter can be partially customized according to a user, but the development environment of wavelet filter coefficients is not provided in the FIR filter IP core provided in Quartus II development software, so that the actual implementation process can be realized by calculating the DB3 wavelet filter coefficients from matlab, then leading the filter coefficients into the IP core of the FIR filter in the Quartus II in a file mode, and finally leading 12 bit data of AD sampling into the wavelet filter to complete the extraction of the fault high-frequency signals.
The high-precision clock unit achieves strict synchronization through a satellite communication mode, for example, a GPS + BDS dual-mode time service module SKG09F produced by SKYALAB company is selected, the product integrates Beidou and GPS time service technologies, simultaneously receives Beidou and GPS satellite signals, has high reliability and safety, and sends second-level time, longitude and latitude and other information to the FPGA through a serial port.
And finally, transmitting the processed fault traveling wave data to a GPRS module provided with the SIM card, and finally transmitting the data by the GPRS module through a GPRS network. And the cloud platform receives the traveling wave data information uploaded by each lower computer in real time.
In some implementation modes, the fault traveling wave acquisition device is an embedded device which is installed in relay protection and automation equipment in an embedded mode and shares a secondary loop of a distribution line.
In some implementations, the fault traveling wave collection device is mounted on a line tower and is provided with a solar cell that supplies power thereto.
Example 2:
as shown in fig. 1, the present embodiment provides a system based on a fault traveling wave collecting device, which includes: the fault traveling wave acquisition device is connected with the traveling wave sensor and the positioning platform, acquires data of the traveling wave sensor and transmits the data to the positioning platform to position a line fault. The traveling wave sensor can be connected to the grounding wire of the shell of the important branch transformer of the line.
The above embodiments are preferred embodiments of the present application, and those skilled in the art can make various changes or modifications without departing from the general concept of the present application, and such changes or modifications should fall within the scope of the claims of the present application.
Claims (10)
1. The fault traveling wave acquisition device of the power distribution network is characterized in that the fault traveling wave acquisition device is connected with both a traveling wave sensor and a positioning platform and is used for transmitting fault traveling wave data acquired from the traveling wave sensor to the positioning platform;
the system comprises a fault traveling wave acquisition device, a traveling wave sensor, a signal adjustment unit, a high-speed sampling unit, a positioning platform and a control unit, wherein the sampling end in the fault traveling wave acquisition device is provided with the signal adjustment unit and the high-speed sampling unit, the high-speed sampling unit is connected with the traveling wave sensor through the signal adjustment unit, and output data of the sampling end is used for data processing of the fault traveling wave acquisition device or the positioning platform;
the signal adjusting unit is internally provided with an adjusting circuit of an operational amplifier based on differential output, so that an output signal of the signal adjusting unit is a differential signal, the high-speed sampling unit is internally provided with a high-speed AD chip for analog-to-digital conversion, and the high-speed AD chip is used for differential input.
2. The traveling wave fault collection device according to claim 1, wherein an AD8131 chip is provided in the adjustment circuit in the signal adjustment unit, and a dc bias voltage exists between signals at two ends output by the AD8131 chip.
3. The traveling-wave fault acquisition device according to claim 1, wherein: and the high-speed AD chip in the high-speed sampling unit is an AD9653 chip.
4. The traveling-wave fault acquisition device according to claim 1, wherein: the processing module in the fault traveling wave acquisition device comprises a clock unit, an FPGA and a communication unit;
the output end of the clock unit is connected with the FPGA and used for providing a clock signal for the FPGA;
the FPGA is respectively connected with the high-speed acquisition unit and the communication unit and used for providing a clock driving signal to the high-speed acquisition unit;
the communication unit is in communication connection with the positioning platform.
5. The traveling-wave fault acquisition device of claim 4, wherein: the processing module in the fault traveling wave acquisition device further comprises a filtering unit, and the filtering unit is connected with the high-speed sampling unit.
6. The traveling-wave fault acquisition device of claim 5, wherein: the filtering unit is a wavelet filter built by using a Quartus built-in IP core method based on FPGA.
7. The traveling fault wave collecting device of claim 1, wherein: the fault traveling wave acquisition device is an embedded device which is installed in relay protection and automation equipment in an embedded mode and shares a secondary loop of the distribution line.
8. The traveling-wave fault acquisition device according to claim 1, wherein: the fault traveling wave acquisition device is arranged on the line tower and is provided with a solar battery.
9. A system based on the fault traveling wave collecting device of any one of claims 1 to 8, characterized in that: the fault traveling wave sensor comprises a fault traveling wave acquisition device and a traveling wave sensor, wherein the fault traveling wave acquisition device is connected with the traveling wave sensor.
10. The system of claim 9, wherein: the fault traveling wave acquisition device is in communication connection with the positioning platform.
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