CN104734128A - Low-voltage distribution network null wire break protector - Google Patents
Low-voltage distribution network null wire break protector Download PDFInfo
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- CN104734128A CN104734128A CN201510111602.9A CN201510111602A CN104734128A CN 104734128 A CN104734128 A CN 104734128A CN 201510111602 A CN201510111602 A CN 201510111602A CN 104734128 A CN104734128 A CN 104734128A
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Abstract
The invention discloses a low-voltage distribution network null wire break protector. The low-voltage distribution network null wire break protector is characterized by being composed of a switch, a voltage relay, an alternating-current contactor and a signal transmitter. Inlet wires L1, L2 and L3 of the voltage relay are connected with an A phase live wire, a B phase live wire and a C phase live wire of a low-voltage distribution network through the switch respectively, an inlet wire N is connected with a null wire, and normally open contacts 98 and 97 are connected with the B phase live wire and a coil of the alternating-current contactor respectively; the normally open main contact side of the alternating-current contactor is connected with the null wire of the distribution network, and the other side of the alternating-current contactor is connected with a grounding body; one end of the signal transmitter is connected with the normally open contact 97 of the voltage relay, and the other end of the signal transmitter is connected with the grounding body. The low-voltage distribution network null wire break protector has the advantages that when the null wire breaks, work grounding is temporarily formed behind the wire break point so that the three-phase voltage can achieve basic balance; a voltage value is within a rated range of electric equipment, the accident of burning the electric equipment is eradicated, normal work of the electric equipment is not affected, and normal operation of the whole zone area distribution network is not affected either.
Description
Technical field
The present invention relates to a kind of protective device, be specifically related to a kind of low-voltage network zero line break protection device, belong to electroporation field.
Background technology
In the low voltage three-phase four-wire system system of common zero line, if zero line (neutral line) is because of accident disconnection, when three-phase load unbalance, each phase voltage will be caused to distort, make the electric voltage exception of each phase load, namely the zero line by disconnecting makes every two-phase load in series form loop and bears line voltage, and in fact, load is unbalanced mostly, threephase load impedance is different, electric current in two phase loads in loop is identical, but load power is different, so the impedance of two phase loads is not identical yet, because U=I*Z, therefore load is large compared with a little phase load impedance, voltage is also high, more than 260V can be reached, the phase load impedance that load is large is little, load voltage reduces, at below 160V, phase voltage rising can cause this phase partial electric equipment burnout, and this part power consumption equipment equipment out of service after, this phase load is lighter, phase voltage is higher, formation vicious circle like this, until this phase load is all burnt or out of service.A finally remaining phase load is obstructed and have a power failure because load in front two-phase burns out rear circuit.
Because low-voltage network neutral line break can cause a large amount of user power utilization equipment burnouts, so electric company needs the maintenance fund paying great number.
In addition, on rear side of zero line break point during electrical appliance enclosure electric leakage, be equivalent to be with phase voltage, once these electrical appliance enclosure of human contact, electric shock injures and deaths will be caused.
Summary of the invention
For solving the deficiencies in the prior art; the object of the present invention is to provide a kind of low-voltage network zero line break protection device; this protective device can make odd-job ground connection on rear side of neutral line break reach the balance of voltage, thus ensures that power consumption equipment normally works while not burnt.
In order to realize above-mentioned target, the present invention adopts following technical scheme:
A kind of low-voltage network zero line break protection device, is characterized in that, be made up of switch, voltage relay, A.C. contactor and signal projector,
The inlet wire L of aforesaid voltage relay
1, L
2and L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by aforementioned switches, inlet wire N is connected with the zero line of low-voltage network, and normally opened contact 98 is connected with B phase firewire, and normally opened contact 97 is connected with the coil of A.C. contactor;
The main contacts side of often opening of aforementioned A.C. contactor is connected with power distribution network zero line, and opposite side is connected with earth electrode;
One end of aforementioned signal reflector is connected with the normally opened contact 97 of voltage relay, and the other end is connected with earth electrode.
Aforesaid low-voltage network zero line break protection device, is characterized in that, aforementioned signal reflector is buzzer.
Aforesaid low-voltage network zero line break protection device, is characterized in that, aforementioned signal reflector is wireless signal transmitter.
Usefulness of the present invention is:
(1) imbalance of three-phase voltage and cross this feature of under voltage when utilizing neutral line break; voltage relay, A.C. contactor and signal projector is adopted to form protective device; when neutral line break; an interim formation working earthing (interim zero line) on rear side of break point; three-phase voltage is made to reach in a basic balance; because voltage swing is in power consumption equipment rated range; therefore stopped power consumption equipment burnout failure; also can not affect the normal work of power consumption equipment, more can not affect the normal operation of whole district's power distribution network.
(2) invest little, economic benefit to give prominence to.
(3) easy and simple to handle, only in the terminal of 0.4 kilovolt, the effect that protective device of the present invention can reach protection one Ge Tai district need be installed.
(4) protective device of the present invention not only can repeatedly use, and can also use as user side protective device.
Accompanying drawing explanation
Fig. 1 is the winding diagram in kind of protective device of the present invention;
Fig. 2 is that line map is decomposed in protective device of the present invention access distribution.
The implication of Reference numeral in figure: 1-switch, 2-voltage relay, 3-A.C. contactor, 4-signal projector.
Embodiment
Below in conjunction with the drawings and specific embodiments, concrete introduction is done to the present invention.
With reference to Fig. 1, low-voltage network zero line break protection device of the present invention is made up of switch 1, voltage relay 2, A.C. contactor 3 and signal projector 4, introduces the mode of connection between them below.
Voltage relay 2 is common voltage relay, and function has: measure A phase firewire and zero voltage between lines, measure B phase firewire and zero voltage between lines, measure C phase firewire and zero voltage between lines, the concrete mode of connection is: the inlet wire L of voltage relay 2
1, L
2and L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by switch 1, inlet wire N is then connected with the zero line of low-voltage network, and normally opened contact 98 is connected with B phase firewire, and normally opened contact 97 is connected with the coil of A.C. contactor 3.When A phase firewire and these three voltages of zero voltage between lines, B phase firewire and zero voltage between lines, C phase firewire and zero voltage between lines wherein any magnitude of voltage raise suddenly (higher than 260V), when any magnitude of voltage reduces suddenly (lower than 160V) simultaneously, normally opened contact 97 and normally opened contact 98 close.
The main contacts side of often opening of A.C. contactor 3 is connected with power distribution network zero line, and opposite side is then connected with earth electrode.
One end of signal projector 4 is connected with the normally opened contact 97 of voltage relay 2, and the other end is connected with earth electrode.
Protective device of the present invention is arranged on power distribution network 400 volts of line ends, and the decomposition line map of access distribution as shown in Figure 2.
With reference to Fig. 2, when low-voltage network normally runs, voltage relay 2 measures low-voltage network three-phase voltage in real time.Because the normally opened contact 97 of voltage relay 2, normally opened contact 98 disconnect, the coil no current of A.C. contactor 3 flows through, so the main contacts of often opening of A.C. contactor 3 is also disconnect, signal projector 4 also no current flows through.
When the low-voltage network neutral line (zero line) disconnects because of accident, the A phase firewire that voltage relay 2 is measured and zero voltage between lines, B phase firewire and zero voltage between lines, C phase firewire and these three voltages of zero voltage between lines have a phase to raise suddenly (higher than 260V), there is a phase to reduce suddenly (lower than 160V) simultaneously, now trigger normally opened contact 97, normally opened contact 98 closes, electric current flows through the coil of A.C. contactor 3, adhesive A.C. contactor 3 often open main contacts, low-voltage network zero line (on rear side of neutral line break point) often leaves main contacts through A.C. contactor and closes ground connection, thus maintain the balance of voltage, protect power consumption equipment not burnt.Meanwhile, electric current also flows through signal projector 4, sends neutral line break signal.
Signal projector 4 can be buzzer, is applicable to on-site supervision, sends ring sound after energising, reminds operation maintenance personnel power distribution network neutral line break.
Signal projector 4 can also be wireless signal transmitter, is applicable to remote monitoring, sends wireless signal, after receiving terminal receives this wireless signal, just know power distribution network neutral line break after energising.
It should be noted that, above-described embodiment does not limit the present invention in any form, the technical scheme that the mode that all employings are equal to replacement or equivalent transformation obtains, and all drops in protection scope of the present invention.
Claims (3)
1. low-voltage network zero line break protection device, is characterized in that, is made up of switch (1), voltage relay (2), A.C. contactor (3) and signal projector (4),
The inlet wire L of described voltage relay (2)
1, L
2and L
3be connected with A, B, C three-phase firewire of low-voltage network respectively by described switch (1), inlet wire N is connected with the zero line of low-voltage network, normally opened contact 98 is connected with B phase firewire, and normally opened contact 97 is connected with the coil of A.C. contactor (3);
The main contacts side of often opening of described A.C. contactor (3) is connected with power distribution network zero line, and opposite side is connected with earth electrode;
One end of described signal projector (4) is connected with the normally opened contact 97 of voltage relay (2), and the other end is connected with earth electrode.
2. low-voltage network zero line break protection device according to claim 1, is characterized in that, described signal projector (4) is buzzer.
3. low-voltage network zero line break protection device according to claim 1, is characterized in that, described signal projector (4) is wireless signal transmitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510111602.9A CN104734128A (en) | 2015-03-13 | 2015-03-13 | Low-voltage distribution network null wire break protector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510111602.9A CN104734128A (en) | 2015-03-13 | 2015-03-13 | Low-voltage distribution network null wire break protector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104734128A true CN104734128A (en) | 2015-06-24 |
Family
ID=53457722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510111602.9A Pending CN104734128A (en) | 2015-03-13 | 2015-03-13 | Low-voltage distribution network null wire break protector |
Country Status (1)
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| CN (1) | CN104734128A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024345A (en) * | 2015-07-08 | 2015-11-04 | 福建省轻安工程建设有限公司 | Construction temporary power utilization control device |
| CN106655140A (en) * | 2017-02-14 | 2017-05-10 | 国网新疆电力公司伊犁供电公司 | Zero line breakage detection protection device for low-voltage power distribution network |
| CN108808640A (en) * | 2018-08-21 | 2018-11-13 | 国网河南省电力公司濮阳供电公司 | A kind of power distribution network zero line-breaking protector and its control method |
Citations (5)
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|---|---|---|---|---|
| CN87100154A (en) * | 1987-01-09 | 1988-07-20 | 尤大千 | Protector for null line breaking |
| CN2230060Y (en) * | 1995-06-22 | 1996-06-26 | 吴震宇 | Protective arrangement for neutral wire for disconnection |
| KR100787488B1 (en) * | 2006-05-10 | 2007-12-21 | 전명수 | Constructing device for concentric neutral conductor cable with function checking ground floating or disconnection from the neutral point of power source and method thereof |
| CN203278188U (en) * | 2013-04-15 | 2013-11-06 | 张循霄 | Zero line breaking protection device |
| CN204809857U (en) * | 2015-03-13 | 2015-11-25 | 国家电网公司 | Low voltage network zero line broken string protection device |
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2015
- 2015-03-13 CN CN201510111602.9A patent/CN104734128A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87100154A (en) * | 1987-01-09 | 1988-07-20 | 尤大千 | Protector for null line breaking |
| CN2230060Y (en) * | 1995-06-22 | 1996-06-26 | 吴震宇 | Protective arrangement for neutral wire for disconnection |
| KR100787488B1 (en) * | 2006-05-10 | 2007-12-21 | 전명수 | Constructing device for concentric neutral conductor cable with function checking ground floating or disconnection from the neutral point of power source and method thereof |
| CN203278188U (en) * | 2013-04-15 | 2013-11-06 | 张循霄 | Zero line breaking protection device |
| CN204809857U (en) * | 2015-03-13 | 2015-11-25 | 国家电网公司 | Low voltage network zero line broken string protection device |
Non-Patent Citations (1)
| Title |
|---|
| 金良勇: "电力局零线断线智能监测保护系统的实施及运用", 《企业技术开发》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024345A (en) * | 2015-07-08 | 2015-11-04 | 福建省轻安工程建设有限公司 | Construction temporary power utilization control device |
| CN105024345B (en) * | 2015-07-08 | 2017-12-05 | 福建省轻安工程建设有限公司 | One kind construction temporary electricity control device |
| CN106655140A (en) * | 2017-02-14 | 2017-05-10 | 国网新疆电力公司伊犁供电公司 | Zero line breakage detection protection device for low-voltage power distribution network |
| CN108808640A (en) * | 2018-08-21 | 2018-11-13 | 国网河南省电力公司濮阳供电公司 | A kind of power distribution network zero line-breaking protector and its control method |
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Application publication date: 20150624 |
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| RJ01 | Rejection of invention patent application after publication |