Traveling wave distance measurement system for 10kV pole-mounted switch

Abstract

The utility model discloses a traveling wave distance measurement system for a 10kV pole-mounted switch, and belongs to the technical field of power distribution automation. Which comprises a traveling wave acquisition module installed in a circuit, and is characterized in that a preprocessing module is arranged, the output end of the traveling wave acquisition module is connected with an analog-to-digital conversion module and the input end of the preprocessing module, and the output end of the analog-to-digital conversion module and the output end of the preprocessing module are connected with the input end of a main control module; the preprocessing module comprises a positive wave head detection loop used for detecting a positive traveling wave head and a negative wave head detection loop used for detecting a negative traveling wave head, and a positive wave head signal output by the positive wave head detection loop and a negative wave head signal output by the negative wave head detection loop are respectively sent to the main control module. According to the traveling wave distance measurement system for the 10kV pole-mounted switch provided by the invention, the preprocessing module is arranged, and the main control module further carries out the positioning and isolation of a fault section after the fault is determined, so that the judgment accuracy is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a travelling wave distance measurement system for 10kV pole-mounted switch belongs to distribution automation technical field. BACKGROUND

[0002] With the rapid development of our country's economy and the acceleration of urban construction process, the power user's requirement to electric energy quality also improves day by day. Distribution network is located in the end of electric power system, and the operation environment is complex, is influenced greatly by natural and human factors, and often presents large area power failure. For this reason, the electric power department deploys a large number of primary and secondary fusion switch devices on the line, to isolate the fault section quickly, restore the normal power supply of non-fault section, reduce the influence range of distribution line fault, and improve the power supply reliability.

[0003] Research shows that when single-phase ground fault occurs in the line, the phase voltage of the fault phase rapidly attenuates and tends to 0, and the phase voltage of the non-fault phase rapidly increases and tends to a stable value, i.e. 3 times of the original steady-state value. The phase-mode transformation of three-phase voltage signals can highlight the change characteristics of line mode and zero mode. After db4 wavelet analysis is performed on the line mode and zero mode, the mode maximum value is selected as the observation point, and then the fault distance can be calculated by using the modulus time difference and the wave velocity. However, in the prior art, when fault positioning is performed based on the travelling wave, the detection of the fault travelling wave often appears misjudgment, which easily causes the fault section to be incorrectly judged, not only affecting the accuracy of subsequent opening and closing operations, but also increasing the calculation load of the controller. Therefore, it becomes a problem to be solved in the field to design a technical solution capable of accurately detecting the fault travelling wave after fault to improve the accuracy of fault section judgment. CONTENT OF THE UTILITY MODEL

[0004] The utility model solves the technical problems: overcome the prior art's insufficient, provide a kind of travelling wave distance measurement system for 10kV pole-mounted switch, by setting preprocessing module, after determining that fault occurs, by main control module further carries out the positioning and isolation of fault section, improve the accuracy of judgment.

[0005] The technical scheme that the utility model solves its technical problems is as follows: the travelling wave distance measurement system for 10kV pole-mounted switch, including the travelling wave acquisition module installed in circuit, characterized by: it is provided with preprocessing module, the output of travelling wave acquisition module is connected with the input of analog-digital conversion module and preprocessing module respectively, and the output of analog-digital conversion module and the output of preprocessing module are connected with the input of main control module respectively;Preprocessing module includes the positive wave head detection loop for detecting positive polarity travelling wave head and the negative wave head detection loop for detecting negative polarity travelling wave head, and the positive polarity wave head signal output by positive wave head detection loop and the negative polarity wave head signal output by negative wave head detection loop are sent into main control module respectively.

[0006] Further, the positive wave head detection circuit includes a positive rate of change setting unit, a positive peak value setting unit, and a positive wave head hold time setting unit, an output end of the positive rate of change setting unit is connected to an input end of the positive wave head hold time setting unit, an output end of the positive peak value setting unit and an output end of the positive wave head hold time setting unit are connected to a positive wave head output unit respectively, a positive polarity wave head signal output by the positive wave head output unit is connected to the negative wave head detection circuit, and a negative polarity wave head signal output by the negative wave head output unit is connected to the positive wave head detection circuit.

[0007] Further, the positive rate of change setting unit, the positive peak value setting unit, and the hold time setting unit are a first level comparison circuit, a second level comparison circuit, and a first high level hold circuit respectively,

[0008] The traveling wave acquisition module is connected to an input end of the first filter circuit, an output end of the first filter circuit is connected to one of the input ends of the first level comparison circuit, the other input end of the first level comparison circuit is connected to a positive rate of change level setting signal, an output end of the first level comparison circuit is connected to an input end of the first high level hold circuit, and an output end of the traveling wave acquisition module and a positive peak value level setting signal are connected to input ends of the second level comparison circuit respectively;

[0009] The positive wave head output unit includes a first AND gate circuit and a third high level hold circuit, an output end of the second level comparison circuit, an output end of the first high level hold circuit, and a negative polarity wave head signal output by the negative wave head output unit are connected to input ends of the first AND gate circuit respectively, an output end of the first AND gate circuit is connected to an input end of the third high level hold circuit, and a positive polarity wave head signal output by the third high level hold circuit is connected to the negative wave head detection circuit.

[0010] Further, the negative wave head detection circuit includes a negative rate of change setting unit, a negative peak value setting unit, and a negative wave head hold time setting unit, an output end of the negative rate of change setting unit is connected to an input end of the negative wave head hold time setting unit, an output end of the negative peak value setting unit and an output end of the negative wave head hold time setting unit are connected to the negative wave head output unit respectively.

[0011] Further, the negative rate of change setting unit, the negative peak value setting unit, and the hold time setting unit are a third level comparison circuit, a fourth level comparison circuit, and a second high level hold circuit respectively,

[0012] The input end of the second filter circuit is connected with the traveling wave acquisition module, the output end of the second filter circuit is connected with one of the input ends of the third level comparison circuit, the other input end of the third level comparison circuit is connected with a negative change rate level setting signal, the output end of the third level comparison circuit is connected with the input end of the second high level holding circuit, and the output end of the traveling wave acquisition module and the negative peak value level setting signal are respectively connected with the input ends of the fourth level comparison module;

[0013] The negative wave head output unit comprises a second AND gate circuit and a fourth high level holding circuit, the output end of the fourth level comparison circuit, the output end of the second high level holding circuit and the positive polarity wave head signal output by the positive wave head output unit are respectively connected with the input ends of the second AND gate circuit, the output end of the second AND gate circuit is connected with the input end of the third high level holding circuit, and the negative polarity wave head signal output by the output end of the third high level holding circuit is connected with the positive wave head detection loop.

[0014] Further, the positive polarity wave head signal output by the positive wave head output unit is connected with the negative wave head detection loop through the first NOT gate circuit, and the negative polarity wave head signal output by the negative wave head output unit is connected with the positive wave head detection loop through the second NOT gate circuit.

[0015] Further, the traveling wave wave head mutation circuit is also arranged, the traveling wave wave head mutation circuit is an OR gate circuit, the positive wave head holding time setting unit, the negative wave head holding time setting unit, the positive polarity wave head signal output by the positive wave head output unit and the negative polarity wave head signal output by the negative wave head output unit are respectively connected with the OR gate circuit, and the output end of the traveling wave wave head mutation circuit, the output end of the positive wave head output unit and the output end of the negative wave head output unit are respectively connected with the main control module.

[0016] Further, the time synchronization module connected with the main control module is also arranged.

[0017] Further, the main control module is connected with the master station through the communication module.

[0018] Compared with the prior art, the utility model has the beneficial effects that:

[0019] In the application, the pre-processing module is arranged, the collected fault traveling wave is analyzed, the change rate of the waveform, the mutation time and the traveling wave wave head amplitude change amount are included, the change rate of the waveform can reflect the initial time of the traveling wave head arrival, the rising or falling mutation time and the traveling wave wave head amplitude change amount, the analysis of these characteristics can judge whether the line has a fault, and after the fault is determined, the main control module further locates and isolates the fault section, and the judgment accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1It is a principle block diagram of a traveling wave distance measurement system for a 10kV pole-mounted switch;

[0021] Figure 2 It is a principle block diagram of a preprocessing unit. DETAILED DESCRIPTION

[0022] Figures 1-2 It is the best embodiment of the utility model, the following will be combined with the attached Figures 1-2 The utility model is further explained.

[0023] As Figure 1 Shown in, a kind of traveling wave distance measurement system for 10kV pole-mounted switch, including main control module, the output end of traveling wave acquisition module for gathering traveling wave data is connected the input end of preprocessing module, traveling wave acquisition module is realized using the traveling wave sensor known in the art, such as the traveling wave sensor based on Rogowski coil is realized.

[0024] The output end of traveling wave acquisition module is also connected the input end of analog-digital conversion module, the output end of analog-digital conversion module and preprocessing module is simultaneously connected the input end of main control module. Still be provided with time circuit, the output end of time circuit is connected the input end of main control module. The output end of main control module is connected the input end of communication module, and main control module is connected with main station through communication module, and communication module can use wired communication mode, also can gather wireless communication mode known in the art.

[0025] As Figure 2 Shown in, in preprocessing module, the output end of traveling wave acquisition module is connected respectively the input end of first filter circuit and second filter circuit, the output end of first filter circuit and second filter circuit is connected respectively one of the input end of first level comparison circuit and one of the input end of third level comparison circuit, the output end of traveling wave acquisition module is also connected respectively one of the input end of second level acquisition circuit and one of the input end of fourth level acquisition circuit.

[0026] The other input end of first level comparison circuit is connected signal I1, signal I1 is used to send in positive rate level setting signal, the other input end of third level comparison circuit is connected signal I3, signal I1 is used to send in negative rate level setting signal. The other input end of second level comparison circuit is connected signal I2, signal I2 is used to send in positive peak value level setting signal, the other input end of third level comparison circuit is connected signal I4, signal I4 is used to send in negative peak value level setting signal.

[0027] The output end of the first level comparison circuit is connected with one input end of the first high level holding circuit, the output end of the third level comparison circuit is connected with one input end of the second high level holding circuit, the other input end of the first high level holding circuit and the second high level holding circuit is connected with signal I5 and signal I6 respectively, and signal I5 and signal I6 are used to send in the holding time setting signal.

[0028] The output end of the first high level holding circuit is connected with one input end of the or gate circuit and one input end of the first and gate circuit, the other input end of the first and gate circuit is connected with the output end of the second level comparison circuit. The output end of the second high level holding circuit is connected with one input end of the or gate circuit and one input end of the second and gate circuit, the other input end of the second and gate circuit is connected with the output end of the fourth level comparison circuit.

[0029] The output end of the first and gate circuit is connected with the input end of the third high level holding circuit, the output end of the third high level holding circuit is connected with one input end of the or gate circuit and one input end of the first not gate circuit, the output end of the first not gate circuit is connected with one input end of the second and gate circuit, and the output end of the third high level holding circuit is used as the output end to output signal O2, and signal O2 represents the positive polarity wave head signal.

[0030] The output end of the second and gate circuit is connected with the input end of the fourth high level holding circuit, the output end of the fourth high level holding circuit is connected with one input end of the or gate circuit and one input end of the second not gate circuit, the output end of the second not gate circuit is connected with one input end of the first and gate circuit, and the output end of the fourth high level holding circuit is used as the output end to output signal O3, and signal O3 represents the negative polarity wave head signal. The output end of the or gate circuit outputs signal O1, and signal O1 represents the traveling wave head mutation signal.

[0031] Signals O1-O3 are used as the output end of the preprocessing module and are connected with different input ends of the main control module respectively, and the main control module is preferably realized by using an FPGA chip.

[0032] The specific working process and working principle are as follows:

[0033] The traveling wave signal in the line is collected by the traveling wave collection module in real time, and the traveling wave signal collected by the traveling wave collection module is sent to the main control module through the analog-digital conversion module and is sent into the preprocessing module.

[0034] In the preprocessing module, signal I1 (positive change rate level setting) is set as 0.3V, signal I2 (positive peak value level setting) is set as 1V, signal I3 (negative change rate level setting) is set as-0.3V, signal I4 (negative peak value level setting) is set as-1V, and signals I5-I6 (holding time setting) are all set as voltage signals with a rising time of 10 microseconds.

[0035] Therefore, when the positive polarity traveling wave level change rate exceeds 0.3V, the negative polarity traveling wave level change rate is lower than-0.3V, and the traveling wave front mutation signal can exist for 10us, and at this time, the traveling wave front appears greater than 1V or less than-1V. In addition, in order to avoid the interference of refracted and reflected traveling waves, it is necessary to confirm again that the voltage signal of the traveling wave front signal mutation time is greater than 1ms, and the traveling wave signal detected at this time is considered to be a fault traveling wave.

[0036] When the main control module determines that the traveling wave signal collected at a certain time is a fault traveling wave, the time module marks the fault time of the traveling wave, and then the main control module locates the fault section and isolates the fault section for the fault traveling wave. The positioning and isolation of the fault section by the traveling wave belong to the public knowledge in the art, and will not be described here.

[0037] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to obtain equivalent embodiments. However, any simple modification, equivalent change and modification of the above embodiments without departing from the technical solution of the present application, according to the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A traveling wave distance measurement system for a 10 kV pole-mounted switch comprising a traveling wave acquisition module installed in the circuit, characterized in that: The pre-processing module is arranged, the output end of the traveling wave acquisition module is connected with the input end of the pre-processing module and the output end of the analog-digital conversion module respectively, the output end of the analog-digital conversion module and the output end of the pre-processing module are connected with the input end of the main control module respectively; the pre-processing module comprises a positive wave head detection circuit for detecting the positive polarity traveling wave head and a negative wave head detection circuit for detecting the negative polarity traveling wave head, the positive polarity wave head signal output by the positive wave head detection circuit and the negative polarity wave head signal output by the negative wave head detection circuit are respectively sent into the main control module.

2. The traveling wave distance measurement system for 10 kV pole-mounted switch according to claim 1, characterized in that: The positive wave head detection circuit comprises a positive change rate setting unit, a positive peak value setting unit and a positive wave head holding time setting unit, the output end of the positive change rate setting unit is connected with the input end of the positive wave head holding time setting unit, the output end of the positive peak value setting unit and the output end of the positive wave head holding time setting unit are respectively connected with the positive wave head output unit, the positive polarity wave head signal output by the positive wave head output unit is connected with the negative wave head detection circuit, and the negative polarity wave head signal output by the negative wave head output unit is connected with the positive wave head detection circuit.

3. The traveling wave distance measurement system for 10 kV pole-mounted switch according to claim 2, characterized in that: The positive change rate setting unit, the positive peak value setting unit and the holding time setting unit are respectively a first level comparison circuit, a second level comparison circuit and a first high level holding circuit, The output end of the first filter circuit is connected with the input end of the first level comparison circuit, the other input end of the first level comparison circuit is connected with the positive change rate level setting signal, the output end of the first level comparison circuit is connected with the input end of the first high level holding circuit, and the output end of the traveling wave acquisition module and the positive peak value level setting signal are respectively connected with the input end of the second level comparison module; The positive wave head output unit comprises a first AND gate circuit and a third high level holding circuit, the output end of the second level comparison circuit, the output end of the first high level holding circuit and the negative polarity wave head signal output by the negative wave head output unit are respectively connected with the input end of the first AND gate circuit, the output end of the first AND gate circuit is connected with the input end of the third high level holding circuit, and the positive polarity wave head signal output by the third high level holding circuit is connected with the negative wave head detection circuit.

4. The traveling wave distance measurement system for 10 kV pole-mounted switch according to claim 2, characterized in that: The negative wave head detection circuit comprises a negative change rate setting unit, a negative peak value setting unit and a negative wave head holding time setting unit, the output end of the negative change rate setting unit is connected with the input end of the negative wave head holding time setting unit, the output end of the negative peak value setting unit and the output end of the negative wave head holding time setting unit are respectively connected with the negative wave head output unit.

5. The traveling wave distance measurement system for 10 kV pole-mounted switch according to claim 4, characterized in that: The negative change rate setting unit, the negative peak value setting unit and the holding time setting unit are respectively a third level comparison circuit, a fourth level comparison circuit and a second high level holding circuit, The output end of the second filter circuit is connected with the input end of the third level comparison circuit, the other input end of the third level comparison circuit is connected with the negative change rate level setting signal, the output end of the third level comparison circuit is connected with the input end of the second high level holding circuit, and the output end of the traveling wave acquisition module and the negative peak value level setting signal are respectively connected with the input end of the fourth level comparison module; The negative wave head output unit comprises a second AND gate circuit and a fourth high level maintaining circuit, the output end of the fourth level comparison circuit, the output end of the second high level maintaining circuit and the positive polarity wave head signal output by the positive wave head output unit are connected to the input end of the second AND gate circuit respectively, the output end of the second AND gate circuit is connected to the input end of the third high level maintaining circuit, and the negative polarity wave head signal output by the output end of the third high level maintaining circuit is connected to the positive wave head detection loop.

6. The traveling wave distance measurement system for 10 kV pole-mounted switch according to claim 2, characterized in that: The positive polarity wave head signal output by the positive wave head output unit is connected to the negative wave head detection loop through the first NOT gate circuit, and the negative polarity wave head signal output by the negative wave head output unit is connected to the positive wave head detection loop through the second NOT gate circuit.

7. The traveling wave fault location system for 10 kV pole-mounted switch according to claim 4, characterized in that: The traveling wave head mutation circuit is also provided, which is an OR gate circuit, the positive polarity wave head signal output by the positive wave head maintaining time setting unit, the negative polarity wave head signal output by the negative wave head maintaining time setting unit, the positive polarity wave head signal output by the positive wave head output unit and the negative polarity wave head signal output by the negative wave head output unit are connected to the OR gate circuit respectively, and the output end of the traveling wave head mutation circuit, the output end of the positive wave head output unit and the output end of the negative wave head output unit are connected to the main control module respectively.

8. The traveling wave fault location system for 10 kV pole-mounted switch according to claim 1, characterized in that: The time synchronization module connected to the main control module is also provided.

9. The traveling wave fault location system for 10 kV pole-mounted switch according to claim 1, characterized in that: The main control module is connected to the main station through the communication module.

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