CN116865209A - Anti-contact leakage protection device - Google Patents
Anti-contact leakage protection device Download PDFInfo
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- CN116865209A CN116865209A CN202310803077.1A CN202310803077A CN116865209A CN 116865209 A CN116865209 A CN 116865209A CN 202310803077 A CN202310803077 A CN 202310803077A CN 116865209 A CN116865209 A CN 116865209A
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/05—Details with means for increasing reliability, e.g. redundancy arrangements
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00001—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00022—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using wireless data transmission
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
- H02J13/00036—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers
- H02J13/0004—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers involved in a protection system
Abstract
The invention discloses an anti-touch leakage protection device, which relates to the field of leakage protection, wherein a controller in the device is respectively connected with a leakage current transformer, a main grounding loop, a standby grounding loop and a current limiting loop; the neutral point of the transformer is connected with the leakage current transformer; the leakage current transformer is respectively connected with the main grounding loop, the standby grounding loop and the current limiting loop; the main grounding loop, the standby grounding loop and the current limiting loop are connected in parallel; one end of the main grounding loop, one end of the standby grounding loop and one end of the current limiting loop are connected with a ground wire; the leakage current transformer is used for collecting leakage current and sending the leakage current to the controller; when the leakage current works normally, the main grounding loop is in a closed state, so that the protection range can be improved, and the reliability of grounding and actions can be ensured.
Description
Technical Field
The invention relates to the field of leakage protection, in particular to an anti-touch leakage protection device.
Background
For many years, although much attention has been paid to the safety use of electricity, especially to the prevention of electric leakage accidents, accidents such as electric shock casualties, electric leakage fires, electric leakage losses and the like still occur, and huge losses are brought to lives and properties of people.
The existing protection equipment for preventing contact and leakage is mainly a leakage protection switch, is arranged at the total input end of alternating current in factories, enterprises and families, and has the following basic technical principle: and detecting the leakage current in real time, and directly tripping the switch when the leakage current is larger than the leakage constant value. But it has the following disadvantages: 1) The intelligent interface is not provided, and the early warning function cannot be realized; 2) The protection range is small, and only factories, enterprises and families governed by the leakage switch can be protected; 3) And the cloud platform can not be connected with the cloud platform to realize data sharing.
Disclosure of Invention
The invention aims to provide an anti-contact leakage protection device which can improve the protection range and ensure the reliability of grounding and the reliability of actions.
In order to achieve the above object, the present invention provides the following solutions:
an anti-contact leakage protection device, comprising: the device comprises a controller, a leakage current transformer, a main grounding loop, a standby grounding loop and a current limiting loop;
the controller is respectively connected with the leakage current transformer, the main grounding loop, the standby grounding loop and the current limiting loop; the neutral point of the transformer is connected with the leakage current transformer; the leakage current transformer is respectively connected with the main grounding loop, the standby grounding loop and the current limiting loop; the main grounding loop, the standby grounding loop and the current limiting loop are connected in parallel; one end of the main grounding loop, one end of the standby grounding loop and one end of the current limiting loop are connected with a ground wire; the leakage current transformer is used for collecting leakage current and sending the leakage current to the controller; the controller is used for controlling the main grounding loop, the standby grounding loop and the current limiting loop according to the leakage current; and when the leakage current works normally, the main grounding loop is in a closed state.
Optionally, the main grounding loop specifically comprises a first relay and a second relay which are sequentially connected; the first relay is also connected with the leakage current transformer and the controller respectively; the second relay is also connected with the controller and the ground wire respectively.
Optionally, the backup ground loop is a third relay.
Optionally, the current limiting loop specifically comprises a current limiting resistor, a current transformer of the current limiting loop and a signal injection transformer which are connected in sequence; the current limiting resistor, the current transformer of the current limiting loop and the signal injection transformer are also respectively connected with the leakage current transformer; the current limiting resistor, the current transformer of the current limiting loop and the signal injection transformer are also respectively connected with the controller; the signal injection transformer is also connected with the ground wire.
Optionally, the controller specifically includes a first controller and a second controller that are sequentially connected; the second controller is respectively connected with the leakage current transformer, the main grounding loop, the standby grounding loop and the current limiting loop.
Optionally, the wireless module is connected with the first controller; the wireless module is used for sending the leakage current and the touch and leakage action information to a cloud platform.
Optionally, the device further comprises a positioning module; the positioning module is connected with the first controller.
Optionally, the display module is further included; the display module is connected with the first controller.
Optionally, the system also comprises a leakage experiment loop; the leakage experiment loop is connected with the ground wire.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides an anti-touch leakage protection device, which comprises: the device comprises a controller, a leakage current transformer, a main grounding loop, a standby grounding loop and a current limiting loop; the controller is respectively connected with the leakage current transformer, the main grounding loop, the standby grounding loop and the current limiting loop; the neutral point of the transformer is connected with the leakage current transformer; the leakage current transformer is respectively connected with the main grounding loop, the standby grounding loop and the current limiting loop; the main grounding loop, the standby grounding loop and the current limiting loop are connected in parallel; one end of the main grounding loop, one end of the standby grounding loop and one end of the current limiting loop are connected with a ground wire; the leakage current transformer is used for collecting leakage current and sending the leakage current to the controller; the controller is used for controlling the main grounding loop, the standby grounding loop and the current limiting loop according to the leakage current; and when the leakage current works normally, the main grounding loop is in a closed state. The leakage current is suppressed in the form of a series impedance in the transformer neutral ground loop. The device designs 3 grounding loops in total, realizes the quick switching of the main grounding loop and the current limiting loop, and the standby grounding loop and the current limiting loop, and ensures the reliability of grounding and the reliability of actions. The protection range is wide, and the electric leakage safety protection of any position of the distribution line managed by the transformer in the whole transformer area can be realized only by installing 1 device.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is an electrical schematic diagram of an anti-contact leakage protection device provided by the invention;
FIG. 2 is a schematic illustration of a contact leakage;
fig. 3 is a schematic diagram of the anti-leakage protection device replaced by an equivalent circuit.
Symbol description:
the device comprises a first controller-MCU 1, a second controller MCU2, a first relay-1, a second relay-2, a third relay-3, a test button-5, a leakage current transformer-6, a current limiting resistor-7, a current limiting loop current transformer-8 and a signal injection transformer-9.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide an anti-contact leakage protection device which can improve the protection range, ensure the reliability of grounding and the reliability of actions, and simultaneously provide an online leakage experiment test means.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
As shown in fig. 1, the anti-touch leakage protection device provided by the present invention includes: the device comprises a controller, a leakage current transformer 6, a main grounding loop, a standby grounding loop and a current limiting loop.
The controller is respectively connected with the leakage current transformer 6, the main grounding loop, the standby grounding loop and the current limiting loop; the neutral point of the transformer is connected with the leakage current transformer 6; the leakage current transformer 6 is respectively connected with the main grounding loop, the standby grounding loop and the current limiting loop; the main grounding loop, the standby grounding loop and the current limiting loop are connected in parallel; one end of the main grounding loop, one end of the standby grounding loop and one end of the current limiting loop are connected with a ground wire; the leakage current transformer 6 is used for collecting leakage current and sending the leakage current to the controller; the controller is used for controlling the main grounding loop, the standby grounding loop and the current limiting loop according to the leakage current; and when the leakage current works normally, the main grounding loop is in a closed state. A leakage current transformer 6 for detecting a current (total leakage current) flowing through the PE ground line; and judging whether the electric leakage fault occurs or not by detecting the magnitude of the current.
The controller specifically comprises a first controller MCU1 and a second controller MCU2 which are sequentially connected; the second controller MCU2 is respectively connected with the leakage current transformer 6, the main grounding loop, the standby grounding loop and the current limiting loop. The first controller MCU1 and the second controller MCU2 are all MCU, and realize the functions of man-machine interaction, wireless communication, GPS timing and positioning, data management and storage and the like. And serial communication connection is adopted between the dual cores of the controller, so that data exchange between the two MCU is realized.
As an alternative embodiment, the main ground circuit specifically includes a first relay 1 and a second relay 2 that are sequentially connected; the first relay 1 is also respectively connected with the leakage current transformer 6 and the controller; the second relay 2 is also connected with the controller and the ground wire respectively. The first relay 1 is connected with the leakage current transformer 6 through the action contact of the relay, and the second relay 2 is connected with the ground wire through the action contact of the relay.
As an alternative embodiment, the backup ground loop is a third relay 3. The first relay 1, the second relay 2 and the third relay 3 are monostable relays; the GPIO1, GPIO2 and GPIO3 interfaces of the second controller MCU2 respectively control the on-off of the action coil loops of the first relay 1, the second relay 2 and the third relay 3 through the relay driving IC to realize the closing and the opening of the action contacts of the first relay 1, the second relay 2 and the third relay 3, so that the purpose of weak current control and strong current is achieved, and meanwhile, the electric isolation between weak current and strong current is realized.
As an alternative embodiment, the current limiting loop specifically comprises a current limiting resistor 7, a current transformer 8 of the current limiting loop and a signal injection transformer 9 which are connected in sequence; the current limiting resistor 7, the current transformer 8 of the current limiting loop and the signal injection transformer 9 are also respectively connected with the leakage current transformer 6; the current limiting resistor 7, the current transformer 8 of the current limiting loop and the signal injection transformer 9 are also respectively connected with the controller; the signal injection transformer 9 is also connected with the ground wire, specifically, the primary side of the signal injection transformer 9 is connected with the DAC1 interface of the second controller MCU2 through a signal driver, and the secondary side of the signal injection transformer 9 is connected with the secondary side of the current-limiting loop current transformer 8; the primary side of the current-limiting loop current transformer 8 and the primary side of the leakage current transformer 6 are connected with the SPI interface of the second controller MCU2 through an analog-to-digital conversion module. The primary side of the current-limiting loop current transformer 8 Is also connected with a resistor in parallel, and the leakage current of the current-limiting loop current transformer 8 Is1. The primary side of the leakage current transformer 6 Is also connected in parallel with a resistor, the leakage current signal output by the leakage current transformer 6 Is, is the total leakage current, and Is1 Is the leakage current in the current limiting loop. When the current limiting loop Is in a working state, the same current Is detected by the Is and the Is1, the sizes of the current limiting loop and the Is1 leakage current transformer 6 are equal, the resolution can reach microampere level, and the Is can only reach milliamp level. The Is1 current Is used for identifying whether the electric shock disappears or not. The current limiting resistor 7 is R1/R2/R3/R4, and has a resistance of 200K and is used for limiting leakage current to safe current. Wherein R3/R1 are protection resistors, and R4/R2 are protection resistors. When a certain resistor is damaged, the current-limiting loop still works normally. The current-limiting loop current transformer 8 is a small-current detection current transformer and is used for detecting the current of the current-limiting loop; when the detected current is smaller than the set value, the contact leakage fault is eliminated, and the device is switched to the main grounding loop or the standby grounding loop from the current limiting loop through time delay. The analog-to-digital conversion module is 16-bit A/D of the SPI interface and collects analog quantity signals such as voltage, current and the like. The signal driver is used for amplifying the power of the D/A output signal, wherein the D/A is a 12-bit digital-to-analog converter in the MCU2, and the digital quantity is converted into the analog quantity.
As an alternative embodiment, the anti-touch leakage protection device further comprises a wireless module connected with the first controller MCU 1; the wireless module is used for sending the leakage current and the touch and leakage action information to a cloud platform. The wireless module is a 4G-LTE wireless module and is used for long-distance data transmission, data butt joint of the device and the cloud platform is achieved, leakage current and touch-leakage action information of the device is sent to the cloud platform, and then the leakage current and touch-leakage action information is pushed to the APP through the cloud platform. Meanwhile, the remote wireless software downloading function of the device can be realized through the cloud platform.
As an alternative embodiment, the anti-touch leakage protection device further comprises a positioning module; the positioning module is connected with the first controller MCU 1. Specifically, the positioning module is connected with the UART1 interface of the first controller MCU1, wherein the positioning module is a Beidou/GPS positioning module and provides accurate timing and positioning for the device. When a contact leakage event occurs, an event record is generated, wherein the event record comprises an action current (leakage current), an occurrence event and a place (longitude and latitude of device installation). The longitude and latitude information of the device can be directly imported into navigation systems such as Tencent, gaode and the like, and real-time positioning information is provided for maintenance personnel.
As an alternative embodiment, the anti-touch leakage protection device further comprises a display module; the display module is connected with the first controller MCU 1. Specifically, the display module is connected with the UART1 interface of the first controller MCU1, and the display module is liquid crystal display.
As an alternative embodiment, the anti-touch leakage protection device further comprises a leakage experiment loop; the leakage experiment loop is connected with the ground wire. The leakage test loop comprises a test button and a resistor R5 (2K ohms, and can verify whether the device can reliably act or not without an external test circuit in an electrified running state, and the working principle is that the test button 5 is pressed down, current flows out from a live wire L, passes through a current limiting resistor 7R5 to PE, returns to a neutral point N of a transformer through a main grounding loop and a leakage current transformer 6, and is quickly switched to a standby loop after the leakage current is collected by the current transformer to be larger than a set value, so that the current of the test loop is inhibited.
As an optional implementation mode, the anti-touch leakage protection device further comprises 1 SPI ferroelectric memory and 1 temperature compensation type high-precision clock chip, wherein the temperature compensation type high-precision clock chip is a RIC real-time clock and is connected with an SPI interface of the second controller MCU2 through an SPI bus. The SPI ferroelectric memory is a nonvolatile ferroelectric memory and is used for parameter preservation, and power failure is avoided.
The invention is suitable for the 10KV/400V distribution transformer. The power distribution system primary main equipment and the second controller MCU2 are protection cores and are used for data acquisition, protection action, event recording, fault wave recording and other functions.
1) The device designs 3 grounding loops in total, a first relay 1 (normally closed node) and a second relay 2 (normally closed node) in fig. 1 are connected in series to serve as a main grounding loop, and under normal conditions, the first relay 1 and the second relay 2 are in a closed state, so that the central point of a transformer is directly grounded, and the main grounding loop is directly grounded; the third relay 3 (normally open node) serves as a backup ground loop, and its node is normally in an open state, so that the backup ground loop is in an open state with the ground. When the main grounding loop fails, the main grounding loop is automatically switched to the standby loop; the current limiting resistor 7, the current transformer 8 of the current limiting loop and the signal injection transformer 9 are connected in series and then grounded, and the current limiting loop is used as a current limiting loop and is bypassed in a state that the main grounding loop is directly grounded or in a state that the standby grounding loop is closed, so that no effect is exerted. The 3 grounding loops correspond to 3 working states, namely a main grounding loop working state, a standby grounding loop working state and a current limiting loop working state, and the device is in the main grounding loop working state by default.
2) Working principles of working states of main grounding loop and current-limiting loop and switching process: in the working state of the main ground circuit, as shown in fig. 2 and 3, is total leakage current, Z1 Is a phase a load, Z2 Is a phase B load, and Z3 Is a phase C load. A/B/C is three-phase electricity. CT is a three-phase current transformer. When the leakage occurs, the leakage current flows into the ground through the human body equivalent resistor, then flows back to the neutral point of the transformer through the main grounding loop of the device, and the MCU identifies whether an electric shock accident occurs or not by collecting the leakage current in the leakage current transformer 6. As shown in fig. 2, the impedance Z may be the impedance of the electric shock human body or other leakage impedance, when an electric leakage accident occurs, the leakage current value or abrupt change value collected by the leakage current transformer 6 in fig. 1 will exceed a set value, the MCU drives the second relay 2 to act, so that the second relay 2 is in an off state, and thus the main ground loop is disconnected from the ground, and an alarm event is generated; the main grounding loop is disconnected from the ground and simultaneously is automatically put into the current limiting loop, the current limiting loop is switched to the working state, the leakage current of the grounding loop is restrained, the leakage current is reduced to be safe current, and the situation that a person with electric shock breaks away from the electric shock is ensured. The judgment of the abrupt change value is used for accelerating the fault identification process and shortening the switching time between the main grounding loop and the current limiting loop.
3) The main grounding loop adopts the function of series connection of normally closed nodes of the first relay 1 and the second relay 2: when an electric shock accident occurs, the leakage current value or the mutation value acquired by the leakage current transformer 6 in fig. 1 exceeds a set value, and the MCU drives the second relay 2 to act so that the second relay 2 is in an off state; if the MCU in this state indicates that the second relay 2 is in a closed state by collecting that the leakage current in the leakage current transformer 6 is still greater than the set value, the MCU immediately drives the first relay 1 to act, so that the first relay 1 is in an open state, thereby disconnecting the main ground loop from the ground while automatically switching into the current limiting loop, and generating alarm information. The first relay 1 in the main grounding loop is used as a standby node of the second relay 2, the on-off of the main grounding loop is realized by only driving the on-off of the second relay 2 at ordinary times, when the second relay 2 fails and can not be disconnected, the first relay 1 is immediately driven to act and keep the disconnected state all the time, so that the main grounding loop keeps the disconnected state all the time, and the main grounding loop is withdrawn from the working state and is shifted to the working state of the standby grounding loop. The judgment of the leakage current abrupt quantity is used for accelerating the fault identification process and shortening the switching time between the standby grounding loop and the current limiting loop.
4) Working principles of the working state of the standby grounding loop and the working state of the current-limiting loop and switching process: in the working state of the standby grounding loop, as shown in fig. 2 and 3, when no contact leakage fault exists, the third relay 3 is driven to be in a closed state, so that the central point of the transformer is directly grounded. When a contact leakage accident occurs, the leakage current value or the mutation value acquired by the leakage current transformer 6 in fig. 1 exceeds a set value, the MCU drives the third relay 3 to act, and the third relay 3 is in an off state, so that the standby grounding loop is disconnected from the ground, and an alarm event is generated; the standby grounding loop is disconnected from the ground and simultaneously is automatically put into the current limiting loop, the current limiting loop is switched to the working state, the leakage current of the grounding loop is restrained, the leakage current is reduced to be safe current, and the situation that a person with electric shock breaks away from the electric shock is ensured. The judgment of the leakage current abrupt quantity is used for accelerating the fault identification process and shortening the switching time between the standby grounding loop and the current limiting loop.
5) The signal injection transformer 9 is used for injecting an inter-harmonic detection signal. The detection signal is a non-integer number of sinusoidal signals of 50HZ of power frequency, such as 25HZ. The signal is only used for detecting whether the main grounding loop is reliably grounded in the working state of the main grounding loop. In the working state of the main grounding circuit, the main grounding circuit must be reliably grounded. And exiting detection under other working states. And when the fact that the main grounding loop is not reliably grounded is detected, an alarm signal is sent out, and the working state of the standby grounding loop is switched.
6) The current-limiting loop current transformer 8 is a 2mA/2mA current transformer and has two functions: <1> detecting the leakage current in the current limiting loop, wherein the current signal is a power frequency signal of 50 HZ; <2> the inter-harmonic signal of 25HZ injected through the signal injection transformer 9 is detected.
Detecting the leakage current in the current-limiting loop working state, and when the leakage current is smaller than a set value, proving that the fault disappears, exiting the current-limiting loop working state, and switching to the main grounding loop working state or the standby grounding loop working state.
And when the inter-harmonic signal of 25HZ is detected to be smaller than a set value in the working state of the main grounding loop, indicating that the main grounding loop is not reliably grounded, sending an alarm signal and switching to the working state of the standby grounding loop.
The device provided by the invention has the following advantages of 1) adopting the form of series impedance in a neutral point grounding loop of a transformer to inhibit the leakage current. 2) The device designs 3 grounding loops in total, realizes the quick switching of the main grounding loop and the current limiting loop, and the standby grounding loop and the current limiting loop, so as to ensure the reliability of grounding and the reliability of actions. Meanwhile, the relay adopts a mode of combining the monostable normally-closed relay and the monostable normally-open relay, so that the reliable grounding of the neutral point can be ensured under the condition that the device loses power or fails. 3) And a signal injection method is adopted to detect whether the relay is reliably closed, and meanwhile, the switching between the main grounding loop and the standby grounding loop is realized. 4) The Beidou/GPS module is introduced to realize accurate time synchronization of the device and positioning of fault points. 5) The leakage test loop is additionally arranged, so that whether the device can reliably act can be verified without an external test circuit.
Compared with the traditional leakage protector, the leakage protector has the following characteristics:
1) The protection range is wide, and the electric leakage safety protection of any position of the distribution line managed by the transformer in the whole transformer area can be realized only by installing 1 device.
2) And the leakage current is inhibited to the safe current on line without power failure.
3) The switching speed is high.
4) The redundancy design and the leakage experiment function are adopted, so that the reliability of grounding and the reliability of actions are greatly improved.
5) The intelligent communication interface is provided, and the remote wireless data communication and remote wireless software downloading functions can be realized.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. The principles and embodiments of the present invention have been described herein with reference to specific examples, the above examples being provided only to assist in understanding the device and its core ideas of the present invention; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.
Claims (9)
1. An anti-contact leakage protection device, comprising: the device comprises a controller, a leakage current transformer, a main grounding loop, a standby grounding loop and a current limiting loop;
the controller is respectively connected with the leakage current transformer, the main grounding loop, the standby grounding loop and the current limiting loop; the neutral point of the transformer is connected with the leakage current transformer; the leakage current transformer is respectively connected with the main grounding loop, the standby grounding loop and the current limiting loop; the main grounding loop, the standby grounding loop and the current limiting loop are connected in parallel; one end of the main grounding loop, one end of the standby grounding loop and one end of the current limiting loop are connected with a ground wire; the leakage current transformer is used for collecting leakage current and sending the leakage current to the controller; the controller is used for controlling the main grounding loop, the standby grounding loop and the current limiting loop according to the leakage current; and when the leakage current works normally, the main grounding loop is in a closed state.
2. The anti-contact leakage protection device according to claim 1, wherein the main ground circuit specifically comprises a first relay and a second relay connected in sequence; the first relay is also connected with the leakage current transformer and the controller respectively; the second relay is also connected with the controller and the ground wire respectively.
3. The anti-contact leakage protection device of claim 1, wherein the backup ground loop is a third relay.
4. The anti-contact leakage protection device according to claim 1, wherein the current limiting loop specifically comprises a current limiting resistor, a current transformer of the current limiting loop and a signal injection transformer which are connected in sequence; the current limiting resistor, the current transformer of the current limiting loop and the signal injection transformer are also respectively connected with the leakage current transformer; the current limiting resistor, the current transformer of the current limiting loop and the signal injection transformer are also respectively connected with the controller; the signal injection transformer is also connected with the ground wire.
5. The anti-contact leakage protection device according to claim 1, wherein the controller specifically comprises a first controller and a second controller connected in sequence; the second controller is respectively connected with the leakage current transformer, the main grounding loop, the standby grounding loop and the current limiting loop.
6. The anti-contact leakage protection device of claim 5, further comprising a wireless module coupled to the first controller; the wireless module is used for sending the leakage current and the touch and leakage action information to a cloud platform.
7. The anti-contact leakage protection device of claim 5, further comprising a positioning module; the positioning module is connected with the first controller.
8. The anti-contact leakage protection device of claim 5, further comprising a display module; the display module is connected with the first controller.
9. The anti-contact leakage protection device of claim 1, further comprising a leakage test loop; the leakage experiment loop is connected with the ground wire.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310803077.1A CN116865209A (en) | 2023-06-30 | 2023-06-30 | Anti-contact leakage protection device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310803077.1A CN116865209A (en) | 2023-06-30 | 2023-06-30 | Anti-contact leakage protection device |
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| CN116865209A true CN116865209A (en) | 2023-10-10 |
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| CN202310803077.1A Pending CN116865209A (en) | 2023-06-30 | 2023-06-30 | Anti-contact leakage protection device |
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| CN (1) | CN116865209A (en) |
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- 2023-06-30 CN CN202310803077.1A patent/CN116865209A/en active Pending
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