CN213875902U - Ground fault monitoring device - Google Patents
Ground fault monitoring device Download PDFInfo
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- CN213875902U CN213875902U CN202022958102.8U CN202022958102U CN213875902U CN 213875902 U CN213875902 U CN 213875902U CN 202022958102 U CN202022958102 U CN 202022958102U CN 213875902 U CN213875902 U CN 213875902U
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Abstract
The utility model discloses a ground fault monitoring device, including at least 2 collection modules that set up respectively in transmission line first position and second position to and, the information that communicates respectively with it concentrates collection module, collection module includes at least 3 information acquisition units that are used for gathering each looks power parameter of transmission line respectively, information acquisition unit sends the parameter of gathering to the collection module in information concentration; the information centralized acquisition module judges whether the ground fault occurs or not based on the voltage and current phase difference mutation of the first position and the second position, judges whether the ground fault occurs or not based on the current difference of the first position and the second position, displays current parameters and ground fault information, accurately monitors power distribution information and the ground fault, and ensures the safety of a power distribution network and a power transmission line.
Description
Technical Field
The utility model relates to a distribution network earth fault location field, especially an earth fault monitoring devices.
Background
The method for positioning the grounding fault of the system with the neutral point passing through the arc suppression coil has the difficulties that the method for positioning the grounding fault of the system with the neutral point passing through the arc suppression coil has increased difficulty due to the introduction of the arc suppression coil, although a residual increment method, a short-circuit fault indicator method, a signal injection method, a first half-wave method and the like are provided in China, the methods have poor effect on the grounding fault with high transition resistance, have low success rate of positioning the grounding fault, and cannot accurately monitor the grounding fault in real time.
SUMMERY OF THE UTILITY MODEL
The utility model discloses an overcome not enough of above technique, for this reason the utility model provides a ground fault monitoring devices through the collection to voltage phase place, electric current phase place and current value, realizes the monitoring to ground fault and alternate short-circuit fault. The practical applicability is strong, can monitor the ground short-circuit fault and also can monitor the interphase short-circuit fault, the judgement is reliable, and the device has important significance for ensuring the safe and stable operation of the power distribution network and the power transmission line.
In order to realize the purpose of the utility model, the utility model provides a ground fault monitoring device, including at least 2 collection modules that set up respectively in transmission line first position and second position to and, the information centralized collection module who communicates respectively with it, collection module includes at least 3 information acquisition units that are used for gathering each phase power parameter of transmission line respectively, information acquisition unit sends the parameter of gathering to the information centralized collection module;
the information acquisition unit at least comprises a voltage phase acquisition unit for acquiring a voltage phase, a current acquisition unit for acquiring a current phase and a current effective value, a signal processing unit coupled with the output ends of the voltage phase acquisition unit and the current acquisition unit, a microprocessor unit coupled with the output end of the signal processing unit, and a wireless communication unit coupled with the communication end of the microprocessor unit, wherein the signal processing unit obtains a voltage and current phase difference based on the acquired current phase and voltage phase; the information centralized acquisition module judges whether the ground fault occurs or not based on the voltage and current phase difference mutation of the first position and the second position, and simultaneously judges whether the ground fault occurs or not based on the current difference of the first position and the second position, and displays current parameters and ground fault information.
Further, the voltage phase acquisition unit comprises a metal electrode, a resistor R, an inductor L, a discharge tube D, a voltage regulator tube D1 and a discharge tube D2 which are arranged around the power transmission line, one end of the resistor R is coupled with one end of the metal electrode and one end of the discharge tube D, the other end of the resistor R is coupled with one end of the inductor L, one end of the inductor L is coupled with a cathode of the voltage regulator tube D1, an anode of the voltage regulator tube D1 is coupled with an anode of the voltage regulator tube D2, and the cathode of the voltage regulator tube D2 and the other end of the discharge tube D are coupled with the ground.
The metal conductor is placed around the power transmission line, so that a stray capacitor can be formed between the metal conductor and the power transmission line, meanwhile, a stray capacitor can be formed between the metal conductor and the ground, voltage phase square signals with the same frequency as the voltage of the power transmission line can be obtained at two ends of the bidirectional voltage-stabilizing tube, sharp corners are removed from the outer part of the metal electrode, and point discharge caused by the approach of the metal electrode to the high-voltage power transmission line is prevented.
Furthermore, the signal processing unit at least comprises a NAND gate chip or an electric energy metering chip.
The signal processing unit can adopt a NAND gate circuit combination, and can also directly adopt an electric energy metering chip to complete the acquisition of voltage and current phase difference signals.
Furthermore, the current acquisition unit at least comprises an open type current transformer.
The input current detected by the open type current transformer is processed and then output to the signal processing unit, the open type current transformer with high precision and small angle can be used for measuring the effective value and the vector angle of the current, and the open type current transformer can bear the insulating property of 400kV and meet the voltage withstanding requirement of a high-voltage transmission line of 10-35 kV.
Furthermore, the information centralized acquisition module comprises a remote communication unit, an information centralized acquisition microprocessor unit, a wireless transmission unit and a display unit, wherein the input ends of the remote communication unit and the wireless transmission unit are coupled with the communication end of the information centralized acquisition microprocessor unit, the input end of the display unit is coupled with the output end of the information centralized acquisition microprocessor unit, and the remote communication unit and the wireless transmission unit at least comprise a GPS wireless transmission module with a time service function.
Further, the display unit at least comprises a screen, and the screen is used for displaying at least the vector sum of the currents in the first position interval and the second position interval, the effective value of each phase current, the interphase short circuit threshold value and the position information of the power transmission line.
The color touch screen from the display unit can be used for monitoring power supply information of the power transmission line at the first position and the second position and prompting ground faults and interphase short-circuit faults.
Furthermore, the remote communication unit and the wireless transmitting unit at least comprise a GPS wireless transmitting module with a time service function.
The utility model has the advantages that:
1. the method comprises the steps of placing a metal conductor around a power transmission line, obtaining a voltage reference based on electric field coupling, and obtaining a phase difference of voltage and current according to the voltage reference.
2. Whether the earth fault occurs is judged based on the sudden change of the voltage and current phase difference and the current vector sum, and the safety of the power distribution network and the power transmission line judged by the earth fault is guaranteed.
3. The open type current transformer with high precision and small angle difference can bear the 400kV insulation performance test and meet the voltage withstanding requirement of a 10-35kV power transmission line.
4. And judging whether an interphase short-circuit fault occurs according to the detected current effective value and a preset interphase short-circuit threshold value.
Drawings
Fig. 1 is a schematic diagram of a module composition and a connection relationship of a ground fault monitoring device according to an embodiment of the present invention;
fig. 2 is a schematic diagram of the composition and connection relationship of the information acquisition unit according to the embodiment of the present invention;
fig. 3 is a schematic circuit diagram of a voltage phase acquisition unit according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a signal processing unit according to an embodiment of the present invention;
FIG. 5 illustrates the principle of phase difference signal acquisition;
fig. 6 is a schematic diagram of the composition and connection relationship of the information centralized collection module according to the embodiment of the present invention;
Detailed Description
In order to facilitate better understanding of the present invention for those skilled in the art, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments, which are given by way of illustration only and thus do not limit the scope of the present invention.
Example 1
As shown in fig. 1, the schematic diagram of the ground fault monitoring device includes 2 acquisition modules disposed at a first position and a second position of a power transmission line, and information centralized acquisition modules respectively communicating with the acquisition modules.
The acquisition module comprises at least 3 information acquisition units for respectively acquiring the current phase, the voltage phase and the current value of each phase of the power transmission line, and the information acquisition units transmit acquired parameters to the information centralized acquisition module; the information centralized acquisition module judges whether the ground fault occurs or not based on the voltage and current phase difference mutation of the first position and the second position, and simultaneously judges whether the ground fault occurs or not based on the current difference of the first position and the second position, and displays current parameters and ground fault information.
As shown in fig. 2, the information collecting unit includes a voltage phase collecting unit for collecting a voltage phase, a current collecting unit for collecting a current phase and a current effective value, a signal processing unit coupled to output terminals of the voltage phase collecting unit and the current collecting unit, a microprocessor unit coupled to an output terminal of the signal processing unit, and a wireless communication unit coupled to a communication terminal of the microprocessor unit.
The incoming line current acquisition unit at least comprises an open type current transformer, accurate measurement of the current of the first position of the power transmission line is achieved, measurement of an effective current value and a vector angle is mainly completed, input current detected by the open type current transformer is processed and then output to the signal processing unit, the open type current transformer with high precision and small angle can be used for completing measurement of the effective current value and the vector angle, the open type current transformer can bear 400kV insulation performance, and the voltage withstanding requirement of the 10-35kV high-voltage power transmission line is met.
As shown in fig. 3, the voltage phase acquisition unit includes a metal electrode, a resistor R, an inductor L, a discharge tube D, a voltage regulator tube D1, and a voltage regulator tube D2, which are disposed around the power transmission line, one end of the resistor R is coupled to the metal electrode and one end of the discharge tube D, the other end of the resistor R is coupled to one end of the inductor L, one end of the inductor L is coupled to the cathode of the voltage regulator tube D1, the anode of the voltage regulator tube D1 is coupled to the anode of the voltage regulator tube D2, and the cathode of the voltage regulator tube D2 and the other end of the discharge tube D are coupled to ground.
The sharp corners of the metal electrodes included in the voltage phase acquisition unit are removed, so that point discharge caused by approach of a high-voltage transmission line is prevented. The voltage phase is obtained by adopting an electric field coupling principle, the metal conductor is placed around the power transmission line, so that a stray capacitor can be formed between the metal conductor and the power transmission line, meanwhile, a stray capacitor can be formed between the metal conductor and the ground, a bidirectional voltage stabilizing circuit consisting of two voltage stabilizing tubes is connected between the two stray capacitors connected in series, or a bidirectional voltage stabilizing tube is directly connected in series, and voltage phase square wave signals with the same frequency as the voltage of the power transmission line can be obtained at the two ends of the bidirectional voltage stabilizing tube.
The signal processing unit can be formed by a nand gate combination circuit as shown in fig. 4, or can directly adopt an electric energy metering chip, such as IDT90E36, to complete the acquisition of the voltage and current phase difference signal. The principle of phase difference signal acquisition is shown in fig. 5, where signal a and signal B are two same-frequency signals with a phase difference of Φ, and one of the signals is inverted, for example, signal a is inverted to obtain a signal
Signal
And then the phase difference signal is obtained by performing AND operation on the phase difference signal and the signal B. In the nand-gate combination circuit shown in figure 4,
the A end inputs a voltage phase signal, the B end inputs a current signal, and the phase difference signal of the current and the voltage is output at a position C through a combined circuit of the NAND gates. Specifically, the nand gate adopts a chip CD40107, resistors R1, R4 and R5 are 100K Ω, and a capacitor C1 is 0.1 uf.
Specifically, the incoming line end microprocessor unit adopts an STM32 microprocessor.
The information acquisition unit further comprises a power supply unit, the output end of the power supply unit is connected with a power supply interface corresponding to the microprocessor unit to provide working electric energy for the microprocessor unit, and the power supply unit adopts a storage battery and solar energy to supply power; the information acquisition unit is close to the high-voltage transmission line when being installed.
As shown in fig. 6, the centralized information collection module includes a remote communication unit, a centralized information collection microprocessor unit, a wireless transmission unit, and a display unit, where the input ends of the remote communication unit and the wireless transmission unit are coupled to the communication end of the centralized information collection microprocessor unit, and the input end of the display unit is coupled to the output end of the centralized information collection microprocessor unit, where the remote communication unit and the wireless transmission unit at least include a GPS wireless transmission module with a time service function. In this embodiment, the display unit is a color touch screen, and is configured to display at least a vector sum of currents in the first position interval and the second position interval, an effective value of each phase current, an interphase short-circuit threshold, and transmission line position information.
The color touch screen from the display unit can be used for monitoring power supply information of the power transmission line at the first position and the second position and prompting ground faults and interphase short-circuit faults.
The ground fault monitoring device of the present invention will be described in further detail with reference to the following embodiments.
The method comprises the steps of monitoring the ground fault of a certain overhead power transmission line with the rated capacity of 630A, installing 3 information acquisition units near a first position and a second position respectively, acquiring voltage phases, current phases and current effective values of A phases, B phases and C phases of the first position and the second position of the high-voltage power transmission line, and obtaining the voltage and current phase differences through a signal processing unit, wherein an information centralized acquisition module receives the voltage and current phase differences and the current values through a wireless transmitting unit. And displays the received parameters on a display unit, i.e., a color touch screen. The monitored parameters comprise section information of the first position and the second position, vector sum of inflow and outflow sections, effective value of each phase current, interphase short-circuit threshold value and the like, wherein the preset interphase short-circuit threshold value is 1000A. The information centralized acquisition microprocessor unit judges whether a ground fault occurs or not based on the phase difference and the current difference, and judges whether an interphase short circuit fault occurs or not according to the fact that the monitored current value is greater than 1000A. And judging whether the inter-phase short-circuit fault occurs according to a set threshold value because the circuit is instantaneously increased when the inter-phase short-circuit fault occurs. It should be noted that, the rated currents of the interphase short-circuit threshold transmission line generally include 630A, 1000A, 2000A, and 3150A, which can be set according to actual situations.
The above description of the embodiments is only intended to help understand the method of the present invention and its core ideas. 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.
Claims (7)
1. A ground fault monitoring device is characterized by comprising at least 2 acquisition modules and a centralized information acquisition module, wherein the acquisition modules are respectively arranged at a first position and a second position of a power transmission line, the centralized information acquisition modules are respectively communicated with the acquisition modules, each acquisition module comprises at least 3 information acquisition units for respectively acquiring power supply parameters of each phase of the power transmission line, and the information acquisition units send the acquired parameters to the centralized information acquisition modules;
the information acquisition unit at least comprises a voltage phase acquisition unit for acquiring a voltage phase, a current acquisition unit for acquiring a current phase and a current effective value, a signal processing unit coupled with the output ends of the voltage phase acquisition unit and the current acquisition unit, a microprocessor unit coupled with the output end of the signal processing unit, and a wireless communication unit coupled with the communication end of the microprocessor unit, wherein the signal processing unit obtains a voltage and current phase difference based on the acquired current phase and voltage phase;
the information centralized acquisition module is used for judging whether the ground fault and the interphase short circuit fault occur or not based on the received power supply parameters and displaying the power supply parameters and the ground fault information.
2. The ground fault monitoring device of claim 1, wherein the voltage phase acquisition unit comprises a metal electrode, a resistor R, an inductor L, a discharge tube D, and voltage regulators D1 and D2, which are arranged around the power transmission line, one end of the resistor R is coupled with the metal electrode and one end of the discharge tube D, the other end of the resistor R is coupled with one end of the inductor L, one end of the inductor L is coupled with a cathode of the voltage regulator D1, an anode of the voltage regulator D1 is coupled with an anode of the voltage regulator D2, and a cathode of the voltage regulator D2 and the other end of the discharge tube D are coupled to ground.
3. The device of claim 1, wherein the signal processing unit comprises at least one nand gate chip or an electric energy metering chip.
4. The ground fault monitoring device of claim 1, wherein the current collection unit comprises at least one open current transformer.
5. The ground fault monitoring device of claim 1, wherein the centralized information collection module comprises a remote communication unit, a centralized information collection microprocessor unit, a wireless transmission unit and a display unit, wherein input terminals of the remote communication unit and the wireless transmission unit are coupled to a communication terminal of the centralized information collection microprocessor unit, and an input terminal of the display unit is coupled to an output terminal of the centralized information collection microprocessor unit.
6. The ground fault monitoring device of claim 5, wherein the display unit comprises at least one screen for displaying at least a vector sum of currents between the first position and the second position, an effective value of each phase current, an interphase short-circuit threshold value, and transmission line position information.
7. The ground fault monitoring device of claim 5, wherein the remote communication unit and the wireless transmission unit at least comprise a GPS wireless transmission module with a time service function.
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| CN202022958102.8U CN213875902U (en) | 2020-12-09 | 2020-12-09 | Ground fault monitoring device |
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| CN202022958102.8U CN213875902U (en) | 2020-12-09 | 2020-12-09 | Ground fault monitoring device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117007905A (en) * | 2023-07-05 | 2023-11-07 | 安徽中邦特种电缆科技有限公司 | Fault position indicating device for cable |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117007905A (en) * | 2023-07-05 | 2023-11-07 | 安徽中邦特种电缆科技有限公司 | Fault position indicating device for cable |
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