GB2583200A

GB2583200A - ARC leakage protection device

Info

Publication number: GB2583200A
Application number: GB2007536.2A
Authority: GB
Inventors: Ma Feng; Shuang Bing; Zhou Lei; Qi Fenfen; Xiang Le; Bernard Jean-Baptiste; Tian Simon
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2017-11-07
Filing date: 2018-11-07
Publication date: 2020-10-21
Also published as: CN207381953U; WO2019091410A1; AU2018363443A1; GB202007536D0

Abstract

Provided is an arc leakage protection device (100), comprising: an arc signal acquisition unit (101), a leakage signal acquisition unit (104), a detection unit (102), and an execution unit (103). The arc signal acquisition unit (101) is coupled to a phase line (L) of a power supply line (112) to obtain a first electrical signal in the power supply line (112). The leakage signal acquisition unit (104) is coupled to the phase line (L) and a neutral line (N) of the power supply line (112) to obtain a second electrical signal in the power supply line (112). The detection unit (102) is coupled to the arc signal acquisition unit (101) and the leakage signal acquisition unit (104), and is configured to identify an arc fault signal in the power supply line (112) on the basis of the first electrical signal, and to identify a leakage fault signal in the power supply line (112) according to the second electrical signal. The execution unit (103) is coupled to the detection unit (102) and is configured to open a switch (113) located in the power supply line (112) in response to the arc fault signal, and to disconnec the switch (113) located in the power supply line (112) in response to the leakage fault signal.

Description

ARC LEAKAGE PROTECTION DEVICE

FIELD

[0001] The present disclosure relate to an arc leakage protection device. BACKGROUND [0002] In power supply lines, arcs (electro-discharges) may occur for various reasons, some of which are undesirable or even dangerous. Such undesirable arcs appearing in power supply lines are generally referred to as arc faults.

[0003] In order to prevent damage caused by arc faults, arc protection devices are usually provided in power supply lines. When the arc protection device detects a signal indicating an arc fault, the trip mechanism of the arc protection device is operated to disconnect the power supply lines from the power source.

[0004] Arc faults can usually be divided into series arc faults, parallel arc faults and ground arc faults. Among them, the fault caused by electrical leakage of one power line can be classified as ground arc faults.

[0005] However, the current arc protection device cannot meet the personal safety requirements due to problems such as a large tripping threshold value and a long tripping time, especially in the case of leakage of one power line.

SUMMARY

[0006] The present disclosure provides an arc leakage protection device. The arc leakage protection device comprises: an arc signal acquisition unit coupled to a phase line of power supply lines to acquire a first electrical signal of the power supply lines; a leakage signal acquiring unit coupled to the phase line and a neutral line of the power supply lines to acquire a second electrical signal of the power supply lines; a detection unit coupled to the arc signal acquisition unit and the leakage signal acquisition unit, which is configured to identify an arc fault signal of the power supply lines based on the first electrical signal, and identify an leakage fault signal of the power supply lines based on the second electrical signal; and an execution unit coupled to the detection unit, which is configured to turn off a switch installed in the power supply lines in response to the arc fault signal, and turn off the switch installed in the power supply lines in response to the leakage fault signal.

[0007] The arc leakage protection device according to the present disclosure can significantly improve the detection of faults caused by leakage of one power line and greatly reduce the triggering response time, thereby being able to meet the requirements for personal safety protection 100081 In addition, through the arc leakage protection device according to the present disclosure, it is possible to simultaneously provide effective protection against leakage faults and arc faults, thereby integrating the conventional arc protection device and the leakage protection device.

[0009] In some embodiments, the detection unit further comprises a filter, a processor and a data storage. The filter is configured to filter the first electrical signal and/or the second electrical signal. The processor is configured to identify the arc fault signal based on the filtered first electrical signal or identify the leakage fault signal based on the filtered second electrical signal, and generate a drive signal for driving the execution unit. The data storage is configured to store parameters for identification.

100101 In some embodiments, the processor is configured to drive the execution unit to turn off the switch installed in the power supply lines, when the arc fault signal or the leakage fault signal is identified.

100111 In some embodiments, the processor is further configured to determine the type of fault that causes the switch to turn off.

[0012] In some embodiments, the arc leakage protection device further comprises a preprocessing unit. The preprocessing unit is coupled between the leakage signal acquisition unit and the detection unit, and is configured to filter and/or amplify the second electrical signal acquired by the leakage signal acquisition unit.

[0013] In some embodiments, the arc leakage protection device further comprises a test unit. The test unit is configured to test the functionality of the detection unit and the execution unit.

[0014] In some embodiments, the test unit further comprises a test button and an electronic switch. The test button is coupled to the detection unit, and the detection unit generates a test signal in response to triggering of the test button. The electronic switch is configured to be turned on in response to the test signal generated by the detection unit, in order to generate a simulated leakage signal of the power supply lines.

[0015] In some embodiments, the arc leakage protection device further comprises a fault indicator.

[0016] In some embodiments, the fault indicator further comprises an LED indicator. The LED indicator indicates the type of fault through a flashing frequency or a flashing number per unit time interval.

[0017] In some embodiments, the arc leakage protection device further comprises an auxiliary power source. The auxiliary power source is coupled to at least one of the arc signal acquisition unit, the leakage signal acquisition unit and the detection unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Through the following detailed description with reference to the accompanying drawings, the above and other objectives, features, and advantages of example embodiments of the present disclosure will become more apparent. In example embodiments of the present disclosure, the same reference signs usually represent the same components.

[0019] FIG I illustrates an exemplary system architecture of the arc leakage protection device according to the present disclosure; and [0020] FIG 2 illustrates an exemplary test unit of the arc leakage protection device according to the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0021] The technical solution of the present disclosure will be illustrated in greater detail below with reference to some embodiments. It should be appreciated that these embodiments are described to better explain and enable those skilled in the art to better understand the present disclosure and is not intended for limiting the scope disclosed herein. On the basis of the embodiments given below, those skilled in the art can combine and adjust features of the embodiments in any manner, which shall belong to the scope of protection of the present disclosure.

[0022] As used herein, the term "comprises" and its variants are to be read as open-ended terms that mean "comprises, but is not limited to." The term "based on" is to be read as "based at least in part on." The term "one example embodiment" is to be read as "at least one embodiment" The term "another embodiment" is to be read as "at least another embodiment." Terms "first," "second" and others can denote different or identical objects. The following text may also contain other explicit or implicit definitions. Unless indicated otherwise, the meaning of the terms is consistent through the context of the present disclosure.

[0023] At present, an arc protection device for arc faults and a leakage protection device for leakage faults are separately provided in the distribution box of the power supply lines. The arc protection device and the leakage protection device are operated independently of each other.

[0024] The main purpose of arc protection is to break the circuit in time when a fault arc occurs, thereby avoiding damage to the load due to overvoltage or overcurrent, and reducing the risk of fire. Since the conventional arc protection device has a large tripping threshold value and a long tripping time, the arc protection device is not suitable for protecting personal safety.

[0025] Leakage protection is often used to switch off the current loop in time when leakage occurs in equipment or lines, so as to avoid electric shock to human body.

[0026] The inventor noticed that the detection of an arc earth fault in an arc protection device can in principle also be applied to the detection of leakage faults. Based on this knowledge, the inventor skillfully expanded functions of leakage protection on an arc protection device, so that the resulting arc leakage protection device can provide the functions of arc protection and leakage protection and meet the AFDD (Arc Fault Detection Device) standard and RCD (Residual Current Device) standard.

[0027] FIG 1 illustrates an exemplary system architecture of the arc leakage protection device 100 according to the present disclosure. To realize the function of arc protection, the arc leakage protection device 100 includes an arc signal acquisition unit 101, a detection unit 102 and an execution unit 103.

[0028] The arc signal acquisition unit 101 is generally coupled to a phase line L of power supply lines 112 to acquire a first electrical signal of the power supply lines 112. It should be understood that the two-wire system shown in FIG 1 is merely exemplary, and the arc leakage protection device 100 according to the present disclosure is also suitable for other types of power supply systems, such as a three-phase four-wire system. It should also be understood that the "first electrical signal" and "second electrical signal" mentioned herein are not intended to limit the signal. The arc signal acquisition unit 101 may be a current transformer or a voltage transformer. Accordingly, the first electrical signal may be a current or a voltage.

[0029] The detection unit 102 is coupled to the arc signal acquisition unit 101 and can identify the arc fault signal in the power supply lines 112 based on the first electrical signal acquired by the arc signal acquisition unit 101.

[0030] The execution unit 103 is coupled to the detection unit 102 and can turn off the switch 113 installed in the power supply lines 112 in response to the arc fault signal identified by the detection unit 102. In this way, the power supply to the load is cut off, so as to prevent from overvoltage or overcurrent.

[0031] According to the present disclosure, the arc leakage protection device 100 further comprises a leakage signal acquisition unit 104. The leakage signal acquisition unit 104 is coupled to the phase line L and the neutral line N of the power supply lines 112, in order to acquire a second electrical signal of the power supply lines 112, for example a signal indicating imbalance in the power supply lines 112. The leakage signal acquiring unit 104 may be a zero-sequence current transformer. When the power supply lines 112 are operated normally, that is, when there is no leakage in the power supply lines 112, the sum of the currents through the primary side of the zero-sequence current transformer is substantially equal to zero, IN + Ir = 0. In this case, there is no induced electromotive force on the secondary side of the zero-sequence current transformer, and thus there is no signal indicating imbalance in the power supply lines 112. If there is leakage or electric shock in the power supply lines 112, the sum of the current through the phase line L and the neutral line N on the primary side of the zero-sequence current transformer is not equal to zero. In this case, a induced electromotive force is generated on the secondary side of the zero-sequence current transformer, and a signal indicating imbalance in the power supply lines 112 will be detected. It should be understood that the two-wire system shown in FIG 1 is merely exemplary, and the arc leakage protection device 100 according to the present disclosure is also suitable for other types of power supply systems, such as a three-phase four-wire system.

[0032] Optionally, in some embodiments, the arc leakage protection device 100 further comprises a preprocessing unit 106. The preprocessing unit 106 is coupled between the leakage signal acquisition unit 104 and the detection unit 102. The second electrical signal or imbalance signal acquired by the leakage signal acquisition unit 104 is filtered and/or amplified by the preprocessing unit 106. In this way, the accuracy of the detection of the imbalance signal can be improved.

[0033] The second electrical signal or the preprocessed second electrical signal is then transmitted to the detection unit 102. The detection unit 102 detects the leakage fault signal of the power supply lines 112. If the detection unit 102 confirms the leakage fault signal, the drive execution unit 103 turns off the switch 113 installed in the power supply lines 112 to achieve leakage protection.

[0034] In this way, it is possible to use the common detection unit 102 to identify the arc fault signal and the leakage fault signal, and it is also possible to use the common execution unit 103 to disconnect the power supply lines, so that the arc leakage protection device according to the present disclosure has arc protection and leakage protection functions simultaneously. Therefore, the separate arc leakage protection device and the leakage protection device can be replaced by the arc leakage protection device according to the present disclosure, thereby saving volume, optimizing the occupied space of the distribution box and saving costs.

[0035] In some embodiments, the arc leakage protection device 100 further comprises an auxiliary power source 105. The auxiliary power supply 105 may be coupled to at least one of the arc signal acquisition unit 101, the leakage signal acquisition unit 104 and the detection unit 102, in order to provide the units with an operating required low-voltage power supply, such as 5V, 12V, 24V and other operating voltages.

[0036] In some embodiments, the detection unit 102 may further include a filter 107, a processor 108, and a data storage 109. The filter 107 may be a band-pass filter which is configured to filter the first electrical signal or the second electrical signal, thereby eliminating the interference in the first electrical signal or the second electrical signal to improve the accuracy of fault detection. The processor 108 identifies the arc fault signal or the leakage fault signal in the filtered first electrical signal or the second electrical signal through an algorithm stored in the data storage 109, for example a firmware. When the processor 108 confirms the fault signal, the processor 108 generates a drive signal to drive the execution unit 103 to turn off the switch 113 installed in the power supply lines 112. The data storage 109 is configured to store parameters for fault identification, such as threshold values of different fault types.

[0037] In some embodiments, the processor 108 may determine the type of fault while identifying the fault signal according to different fault identification algorithms, which includes for example series arc faults, parallel arc faults, wound arc faults, and leakage arc faults.

[0038] In some embodiments, the arc leakage protection device 100 further comprises a fault indicator 111. In this way, it is possible to indicate the type of fault that caused the switch 113 to switch off, thereby facilitating to carry out corresponding repair measures.

[0039] In some embodiments, the fault indicator 111 may include an LED indicator. The detection unit 102 sends different control signals to the LED indicator according to the determined fault type, so that the LED indicator indicates the fault type through the flashing frequency or the flashing number per unit time interval. The fault type may include but not limited to the following types: series arc fault, parallel arc fault, leakage fault, overvoltage fault, and device internal fault. In this way, it is possible to easily determine the fault cause.

[0040] In some embodiments, the arc leakage protection device 100 further comprises a test unit 110. The test unit 110 can be used to test the functionality of the detection unit 102 and the execution unit 103. After the test unit 110 is manually triggered, the arc leakage protection device 100 is tested with respect to the arc protection function and the leakage protection function to ensure the requirements of AFDD and RCD standards.

[0041] FIG 2 illustrates an exemplary test unit 110 of the arc leakage protection device 100 according to the present disclosure. In the example shown in FIG 2, the test unit 110 mainly includes a test button 201 and an electronic switch 202. When user presses the test button 201, the detection unit 102 or the processor 108 recognizes a test start signal and begins the test. First, a self-test of the arc detection circuit part is performed. When the arc detection circuit part is successfully tested, the leakage detection circuit part is carried out. The self-test of the arc detection circuit part can be performed in a known manner, which will not be repeated herein. In the following, only the self-test of the leakage detection circuit part is described in conjunction with FIG 2.

[0042] As shown in FIG. 2, after starting to test the leakage detection circuit part, the processor 108 sends a test signal to the electronic switch 202. The electronic switch 202 may be a transistor. The emitter of the transistor is connected to the virtual ground of the circuit board and the collector is connected to the power supply lines 112 via a resistor 203. In the example of FIG 2, the collector is connected to the phase line L. When the basis of the electronic switch 202 receives the test signal from the processor 108, the electronic switch 202 is turned on, thereby forming a closed test loop including the phase line L, the resistor 203, the electronic switch 202 and the ground to simulate the event of leakage in the line L. The resistor 203 is used to limit the current flowing through the electronic switch 203 and to protect the electronic switch 203.

[0043] In this case, since a part of the current in the phase line L flows into the test loop, the sum of current on the primary side of the leakage signal acquisition unit 104 (or the zero-sequence current transformer) is not equal to zero, thereby sensing an imbalance signal. The resulting imbalance signal can also be referred to as simulated leakage signal.

[0044] In the example of FIG 2, the execution unit 103 includes an electronic switch 204 and a trip coil 205. If the detection unit 102 receives the simulated leakage signal, the detection unit 102 sends a drive signal to the electronic switch 204 of the execution unit 103 and drives the trip coil 205 to turn off the switch 113 installed in the power supply lines 112.

[0045] If the detection unit 102 does not send a drive signal, or the execution unit 103 does not disconnect the lines in response to the drive signal, the test of the leakage detection circuit part is abnormal. In this case, the detection unit 102 may send a control signal to the fault indicator 111, so that the fault indicator 111 indicates the self-test fault by a flashing frequency or a flashing number per unit time interval.

[0046] Various embodiments of the present disclosure have been described above. The above explanation is illustrative rather than exhaustive and is not limited to the disclosed embodiments. Without departing from the scope and spirit of each explained embodiment, many alterations and modifications are obvious for those ordinary skilled in the art. The selection of terms in the text aims to best explain principle, actual application or technical improvement in the market of each embodiment or make each embodiment disclosed in the text comprehensible for those ordinary skilled in the art.

Claims

I/We Claim: 1. An arc leakage protection device (100), comprising: an arc signal acquisition unit (101) coupled to a phase line (L) of power supply lines (112) to acquire a first electrical signal of the power supply lines (112); a leakage signal acquiring unit (104) coupled to the phase line (L) and a neutral line (N) of the power supply lines (112) to acquire a second electrical signal of the power supply lines (112); a detection unit (102) coupled to the arc signal acquisition unit (101) and the leakage signal acquisition unit (104), which is configured to identify an arc fault signal of the power supply lines (112) based on the first electrical signal, and identify an leakage fault signal of the power supply lines (112) based on the second electrical signal; and an execution unit (103) coupled to the detection unit (102), which is configured to turn off a switch (113) installed in the power supply lines (112) in response to the arc fault signal, and turn off the switch (113) installed in the power supply lines (112) in response to the leakage fault signal.
2. The arc leakage protection device (100) according to claim 1, wherein the detection unit (102) further comprises: a filter (107) configured to filter the first electrical signal and/or the second electrical signal a processor (108) configured to identify the arc fault signal based on the filtered first electrical signal or identify the leakage fault signal based on the filtered second electrical signal, and generate a drive signal for driving the execution unit (103); and a data storage (109) configured to store parameters for identification.
3. The arc leakage protection device (100) according to claim 2, wherein the processor (108) is configured to drive the execution unit (103) to turn off the switch (113) installed in the power supply lines (112) when the arc fault signal or the leakage fault signal is identified.
The arc leakage protection device (100) according to claim 2, wherein the processor (108) is further configured to determine the type of fault that causes the switch (113) to turn off.
5. The arc leakage protection device (100) according to claim 1, further compri sing: a preprocessing unit (106) coupled between the leakage signal acquisition unit (104) and the detection unit (102), which is configured to filter and/or amplify the second electrical signal acquired by the leakage signal acquisition unit (104).
6. The arc leakage protection device (100) according to any of claims 1 to 5, further comprising: a test unit (110) configured to test the functionality of the detection unit (102) and the execution unit (103).
7. The arc leakage protection device (100) according to claim 6, the test unit (110) further comprising: a test button (201) coupled to the detection unit (102), wherein the detection unit (102) generates a test signal in response to triggering of the test button (201); and an electronic switch (202) configured to be turned on in response to the test signal generated by the detection unit (102) to generate a simulated leakage signal of the power supply lines (112).
8. The arc leakage protection device (100) according to claim 4, wherein the arc leakage protection device (100) further comprises a fault indicator (111)
9. The arc leakage protection device (100) according to claim 8, wherein the fault indicator (111) further comprises an LED indicator, and wherein the LED indicator indicates the type of fault through a flashing frequency or a flashing number per unit time interval.
10. The arc leakage protection device (100) according to any of claims 1 to 5, further compri sing: an auxiliary power source (105) coupled to at least one of the arc signal acquisition xi unit (101), the leakage signal acquisition unit (104) and the detection unit (102).