Ground fault section selection device for power distribution network area
By setting up current measurement modules at the incoming and outgoing ends of the distribution network section and simultaneously collecting the current vector difference, the problem of inaccurate fault location in the high transition resistance grounding system of the neutral point grounding through the arc suppression coil was solved, realizing fast and accurate grounding fault segment selection and improving power supply reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HOHAI UNIV
- Filing Date
- 2025-04-07
- Publication Date
- 2026-04-10
AI Technical Summary
In the existing technology, the grounding fault location method of the neutral point grounding system through the arc suppression coil is not effective in locating grounding faults with high transition resistance, which requires maintenance personnel to shut down the power for investigation or conduct live line inspection, which is time-consuming, labor-intensive and prone to misjudgment.
A current measurement module is installed at the incoming and outgoing ends of a designated section of the distribution network. A timing module is used to send a timing signal synchronously, so that the current measurement sensor can synchronously collect the three-phase current vector values and calculate the current vector difference between the incoming and outgoing ends to determine whether a ground fault has occurred.
No power outages are required for modification, significantly shortening the time for selecting ground fault segments and improving the accuracy of ground fault assessment and the reliability of power distribution network.
Smart Images
Figure CN224109580U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the electric power system fault location technical field relates to a distribution network regional grounding fault section device. BACKGROUND
[0002] The neutral point grounding mode of the medium voltage distribution system includes neutral point non-grounding, neutral point grounding through small resistance and neutral point grounding through arc suppression coil. At present, the grounding fault line selection positioning of the neutral point grounding through arc suppression coil system generally adopts residual increment method (changing arc suppression coil reactance value or parallel connection of medium resistance on arc suppression coil), short circuit fault indicator method, signal injection method and first half wave method, but these methods are not good for high transition resistance grounding fault positioning, which leads to the need of maintenance personnel to stop power supply and check or live line patrol, time-consuming and laborious, and easy to misjudge. INVENTION CONTENTS
[0003] The utility model aims at overcoming the deficiency in prior art, providing a distribution network regional grounding fault section device, and improving grounding fault research and judgment efficiency.
[0004] To achieve the above-mentioned purpose, the utility model is adopted with the following technical scheme:
[0005] The utility model provides a distribution network regional grounding fault section device, and the device comprises two current measurement and transmission devices.
[0006] One of the current measurement and transmission devices is arranged at the incoming line end of the pre-delineated section of the distribution network, and the other is arranged at the outgoing line end of the pre-delineated section of the distribution network.
[0007] The current measurement and transmission device comprises a current measurement module, a time grant module and a data transmission module.
[0008] The output end of the time grant module is connected with the input end of the current measurement module.
[0009] The output end of the current measurement module is connected with the input end of the data transmission module.
[0010] The data transmission module of the incoming line end is in communication connection with the data transmission module of the outgoing line end.
[0011] Further, the current measurement module comprises an A-phase current measurement sensor, a B-phase current measurement sensor, a C-phase current measurement sensor, a metering unit, a microprocessor and an RS485 unit.
[0012] The output end of the A-phase current measurement sensor, the output end of the B-phase current measurement sensor and the output end of the C-phase current measurement sensor are all connected with the input end of the metering unit.
[0013] The output end of the metering unit is connected with the input / output port of the microprocessor;
[0014] The data transmission module is connected with the communication interface of the microprocessor through the RS485 unit.
[0015] Further, the A-phase current measurement sensor, the B-phase current measurement sensor and the C-phase current measurement sensor each comprise a current transformer configured as 1000A:5A and a current transformer configured as 5A:5mA connected in series.
[0016] Further, the metering unit comprises an ATM90E36 chip; and the RS485 unit comprises an RSM3485PHT chip.
[0017] Further, the microprocessor comprises an STM32 microprocessor chip.
[0018] Further, the current measurement module further comprises a display unit to display the current vector difference measured by the current measurement module of the incoming line end and the current measurement module of the outgoing line end.
[0019] Further, the current measurement module further comprises an address unit to uniquely identify the current measurement module.
[0020] Further, the current measurement module further comprises a power supply unit;
[0021] The power supply unit is used to adjust the output voltage of the power supply to provide working power supply for the devices in the current measurement module.
[0022] Further, the time-providing module comprises a GPS / Beidou dual-mode module with a model number of ATK-S1216F8-BD.
[0023] Further, the data transmission module comprises a data transmission terminal with a model number of DTU_DL7300_4G.
[0024] Compared with the prior art, the utility model has the beneficial effects that:
[0025] The power distribution network regional grounding fault sectioning device provided by the utility model is characterized in that current measuring modules are arranged at the incoming line end and the outgoing line end of the power distribution network regional sectioning, and the current measuring sensors of the incoming line end and the outgoing line end are synchronously sent with timing signals by a timing module, so that the current measuring sensors can synchronously collect the three-phase current vector values of the incoming line end and the outgoing line end, and then the current vector difference values of the incoming line end and the outgoing line end are obtained, and whether the region sectioned by the incoming line end and the outgoing line end has a grounding fault is judged according to the current vector difference values of the incoming line end and the outgoing line end. BRIEF DESCRIPTION OF DRAWINGS
[0026] Figure 1 A structure schematic view of a power distribution network regional grounding fault sectioning device provided by the utility model embodiment is shown in the figure.
[0027] Figure 2 A circuit structure schematic view of the power supply unit in the utility model embodiment is shown in the figure, which is used for converting 220VAC / DC into 5VDC.
[0028] Figure 3 A circuit structure schematic view of the power supply unit in the utility model embodiment is shown in the figure, which is used for converting 5VDC into 3.3VDC.
[0029] Figure 4 A structure schematic view of the first current measuring module in the utility model embodiment is shown in the figure.
[0030] Figure 5 A structure schematic view of the second current measuring module in the utility model embodiment is shown in the figure.
[0031] Figure 6 A principle schematic view of the power distribution network regional grounding fault sectioning device in the utility model embodiment is shown in the figure. DETAILED DESCRIPTION
[0032] The utility model technical scheme will be explained in detail below by means of the drawings and specific embodiments, and the same reference signs in the drawings indicate the same or similar components or parts, and the person skilled in the art should understand that the drawings are not necessarily drawn to scale. The specific features in the embodiments and the embodiments of the present application are detailed explanations of the technical scheme of the present application, and not limitations of the technical scheme of the present application, and the technical features in the embodiments and the embodiments of the present application can be combined with each other without conflict.
[0033] In the description of the utility model, need understanding is, the term "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "internal", "external" and so on indicate the orientation or positional relation based on the orientation or positional relation shown in the drawing, just for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore can not be understood as a limitation on the utility model. In addition, the term "and / or" in this paper is only a description of the association between the associated objects, which means that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.
[0034] In the description of the utility model, it should be explained that, unless otherwise expressly provided and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood through specific circumstances.
[0035] The utility model embodiment provides a kind of distribution network regional grounding fault section device, device includes: two identical current measurement and transmission device;One of the current measurement and transmission device is set to the incoming line end of distribution network pre-delineated section, and the other is set to the outgoing line end of distribution network pre-delineated section.The current measurement and transmission device includes current measurement module, time module and data transmission module;The output of time module is connected with the input of current measurement module;The output of current measurement module is connected with the input of data transmission module;The data transmission module of the incoming line end is connected with the data transmission module of the outgoing line end.
[0036] As Figure 1As shown, in the embodiment, the current measurement and transmission device arranged at the incoming line end of the pre-delineated section of the power distribution network comprises a first current measurement module, a first time module and a first data transmission module; the current measurement and transmission device arranged at the outgoing line end of the pre-delineated section of the power distribution network comprises a second current measurement module, a second time module and a second data transmission module. The output end of the first time module is connected with the input end of the first current measurement module; the output end of the first current measurement module is connected with the input end of the first data transmission module; the output end of the second time module is connected with the input end of the second current measurement module; the output end of the second current measurement module is connected with the input end of the second data transmission module; and the first data transmission module and the second data transmission module are in communication connection.
[0037] The current measurement module comprises an A-phase current measurement sensor, a B-phase current measurement sensor, a C-phase current measurement sensor, a metering unit, a microprocessor and an RS485 unit. The output end of the A-phase current measurement sensor, the output end of the B-phase current measurement sensor and the output end of the C-phase current measurement sensor are all connected with the input end of the metering unit; the output end of the metering unit is connected with the input end I / O port of the microprocessor; and the data transmission module is connected with the communication interface of the microprocessor through the RS485 unit.
[0038] The A-phase current measurement sensor, the B-phase current measurement sensor and the C-phase current measurement sensor are respectively used for collecting three-phase currents, and the metering unit calculates three-phase current vector values according to the three-phase currents.
[0039] In the embodiment, the A-phase current measurement sensor, the B-phase current measurement sensor and the C-phase current measurement sensor all comprise a current transformer configured as 1000A:5A and a current transformer configured as 5A:5mA which are connected in series.
[0040] In the embodiment, the metering unit comprises an ATM90E36 chip.
[0041] In the embodiment, the RS485 unit comprises an RSM3485PHT chip.
[0042] In the embodiment, the microprocessor adopts an STM32 microprocessor chip.
[0043] In addition, the current measurement module further comprises a display unit and an address unit. The display unit is used for displaying the current vector difference value measured by the current measurement module of the incoming line end and the current measurement module of the outgoing line end; and the address unit is used for uniquely identifying the current measurement module.
[0044] Because the current measurement module in the utility model is completely same structure, the incoming line end and outgoing line end of the multiple sections of the power distribution network are provided with the current measurement module, therefore the current measurement module needed to be used is more, in order to avoid confusion, each current measurement module is identified through the address unit.
[0045] In the embodiment, the address unit adopts 16-bit dial switch.
[0046] The current measurement module of the utility model still includes power unit, the role of power unit is to adjust power output voltage, through the mode of step-down voltage regulation, let power voltage meet the demand of each device in the device.
[0047] Power unit generally adopts 12VDC battery power supply or 110-220VAC / DC power supply.
[0048] In the embodiment, power unit adopts AP05N15-Zero power conversion module to convert 110-220VAC / DC into 5VDC, and AMS-1117 power conversion module to convert 5VDC into 3.3VDC.
[0049] As shown in Figure 2 The module input voltage range is wide 85-265VAC, energy conversion efficiency is 80%, compared with other power modules, the module has the advantages of small size, high conversion efficiency, low output ripple, low noise and high reliability, in order to improve the ability to provide normal working power in strong electromagnetic interference, increase the input end of power module pressure sensitive resistance R2 to prevent surge voltage from burning power module, add thermal resistance R1 to reduce the impact current in the starting process of device, add X2 type safety capacitor CX2, common mode inductance LCM to eliminate common mode interference, increase resistance R3 for discharging capacitor CX2 after power off, increase rod type inductance LDM at the output end to reduce current ripple, increase CBB capacitor C3 to filter high-frequency noise. As shown in Figure 3 C13, C14, C15 are filter capacitors, wherein C13 is connected in parallel at the input end, C14, C15 are connected in parallel at the output end.
[0050] As shown in Figure 4As shown, in this embodiment, the first current measurement module specifically includes: a first A-phase current measurement sensor, a first B-phase current measurement sensor, a first C-phase current measurement sensor, a first metering unit, a first microprocessor, a first RS485 unit, a first display unit, a first address unit, and a first power supply unit. The output terminals of the first A-phase current measurement sensor, the first B-phase current measurement sensor, and the first C-phase current measurement sensor are all connected to the input terminal of the first metering unit; the output terminal of the first metering unit is connected to the I / O port of the first microprocessor; the first data transmission module is connected to the communication interface of the first microprocessor through the first RS485 unit; the first display unit, the first address unit, and the first power supply unit are all connected to the first microprocessor.
[0051] like Figure 5 As shown, in this embodiment, the second current measurement module specifically includes: a second A-phase current measurement sensor, a second B-phase current measurement sensor, a second C-phase current measurement sensor, a second metering unit, a second microprocessor, a second RS485 unit, a second display unit, a second address unit, and a second power supply unit. The output terminals of the second A-phase current measurement sensor, the second B-phase current measurement sensor, and the second C-phase current measurement sensor are all connected to the input terminal of the second metering unit; the output terminal of the second metering unit is connected to the I / O port of the second microprocessor; the second data transmission module is connected to the communication interface of the second microprocessor through the second RS485 unit; the second display unit, the second address unit, and the second power supply unit are all connected to the second microprocessor.
[0052] In this embodiment, the timing module adopts a GPS / BeiDou dual-mode module with model number ATK-S1216F8-BD.
[0053] In this embodiment, the data transmission module uses a data transmission terminal with model number DTU_DL7300_4G.
[0054] The working process of this utility model device is as follows: the power supply and distribution network is divided into several areas to be detected. Three-phase current measurement sensors of the current measurement module are installed at the boundary of each area. The Beidou time synchronization module provides time synchronization to the current measurement module. At the same time, the three-phase current vector values of the incoming line and the three-phase current vector values of the outgoing line are collected, and then the difference between the current vectors of the incoming and outgoing lines is obtained. Based on the difference between the current vectors of the incoming and outgoing lines, it is determined whether a ground fault has occurred. If the difference between the current vectors of the incoming and outgoing lines is close to zero, then no ground fault has occurred. If the difference between the current vectors of the incoming and outgoing lines is much greater than zero, then a ground fault has occurred.
[0055] like Figure 6As shown, I1 is the incoming line end zero sequence current, I2 is the outgoing line end zero sequence current, CT1 is the incoming line end zero sequence current transformer, which can measure I1, and CT2 is the outgoing line end zero sequence current transformer, which can measure I2. CA 、 CB 、 CC I1, I2, I3 are respectively the currents generated by the distributed capacitances of the A, B, C three-phase transmission lines to the ground. RA 、 RB 、 RC I1, I2, I3 are respectively the currents generated by the distributed resistances of the A, B, C three-phase transmission lines to the ground. CA 、 CB 、 CC I1, I2, I3 are respectively the currents generated by the distributed resistances of the A, B, C three-phase transmission lines to the ground. RA 、 RB 、 RC I1, I2, I3 are respectively the currents generated by the distributed resistances of the A, B, C three-phase transmission lines to the ground. E , then I1-I2=I E . Therefore, if I1-I2=I E , it indicates that no ground fault occurs, and if I1-I2>I E , it indicates that a ground fault occurs.
[0056] The above only describes preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled persons in the technical field, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present disclosure / present application.
Claims
1. A power distribution network regional ground fault sectioning device, characterized by, The utility model relates to a current measurement and transmission device for power distribution network, comprising: two current measurement and transmission devices; one of the current measurement and transmission devices is arranged at the incoming line end of a pre-designated section of the power distribution network, and the other is arranged at the outgoing line end of the pre-designated section of the power distribution network; the current measurement and transmission device comprises a current measurement module, a time-providing module and a data transmission module; the output end of the time-providing module is connected to the input end of the current measurement module; the output end of the current measurement module is connected to the input end of the data transmission module; the data transmission module at the incoming line end is communicatively connected to the data transmission module at the outgoing line end.
2. The power distribution network zone ground fault sectioning device of claim 1, wherein, the current measurement module comprises an A-phase current measurement sensor, a B-phase current measurement sensor, a C-phase current measurement sensor, a metering unit, a microprocessor and an RS485 unit; the output end of the A-phase current measurement sensor, the output end of the B-phase current measurement sensor and the output end of the C-phase current measurement sensor are all connected to the input end of the metering unit; the output end of the metering unit is connected to the input I / O port of the microprocessor; the data transmission module is connected to the communication interface of the microprocessor through the RS485 unit.
3. The power distribution network zone ground fault sectioning device of claim 2, wherein, the A-phase current measurement sensor, the B-phase current measurement sensor and the C-phase current measurement sensor all comprise a current transformer configured as 1000A:5A and a current transformer configured as 5A:5mA connected in series.
4. The power distribution network zone ground fault sectioning device of claim 2, wherein, the metering unit comprises an ATM90E36 chip; and the RS485 unit comprises an RSM3485PHT chip.
5. The power distribution network zone ground fault sectioning device of claim 2, wherein, the microprocessor comprises an STM32 microprocessor chip.
6. The power distribution network zone ground fault sectioning device of claim 1, wherein, the current measurement module further comprises a display unit to display the current vector difference measured by the current measurement module at the incoming line end and the current measurement module at the outgoing line section.
7. The power distribution network zone ground fault sectioning device of claim 1, wherein, the current measurement module further comprises an address unit to uniquely identify the current measurement module.
8. The power distribution network zone ground fault sectioning device of claim 1, wherein, the current measurement module further comprises a power supply unit; the power supply unit is used to adjust the output voltage of the power supply to provide working power supply for the devices in the current measurement module.
9. The power distribution network zone ground fault sectioning device of claim 1, wherein, the time-providing module comprises a GPS / Beidou dual-mode module with model number ATK-S1216F8-BD.
10. The power distribution network zone ground fault sectioning device of claim 1, wherein, the data transmission module comprises a data transmission terminal with model number DTU_DL7300_4G.