CN104410055A - Protection circuit for power supply line - Google Patents

Protection circuit for power supply line Download PDF

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Publication number
CN104410055A
CN104410055A CN201410764254.0A CN201410764254A CN104410055A CN 104410055 A CN104410055 A CN 104410055A CN 201410764254 A CN201410764254 A CN 201410764254A CN 104410055 A CN104410055 A CN 104410055A
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China
Prior art keywords
supply line
unit
voltage
level
controllable silicon
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Granted
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CN201410764254.0A
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Chinese (zh)
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CN104410055B (en
Inventor
倪向勇
陈志伟
倪向宇
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Zhejiang Zhong Fu Electric Applicance Co., Ltd
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YUEQING ZHONGMAO INTELLIGENT TECHNOLOGY Co Ltd
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Priority to CN201410764254.0A priority Critical patent/CN104410055B/en
Publication of CN104410055A publication Critical patent/CN104410055A/en
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Abstract

The invention provides a protection circuit for a power supply line. The protection circuit comprises a current transducer, a rectifying unit, a detection unit and a protection unit, wherein a fire wire of the power supply line penetrates through a magnetic ring of the current transducer; the rectifying unit is used for converting induction current generated by a coil of the current transducer into direct current voltage; the detection unit is used for acquiring direct current voltage from the rectifying unit; when the power supply line has no overload or short-circuit faults, a first level is outputted by the detection unit; when the power supply line has the overload fault, a second level is outputted by the detection unit in a delay mode; when a power supply detection line has the short-circuit fault, the second level is immediately outputted by the detection unit; the protection unit is used for controlling the power supply line to keep conductive when the detection unit outputs the first level and controlling the power supply line to be broken off when the detection unit outputs the second level, so delay power outage of the load during overload and instant power outage of the load during short circuit can be realized by accurate control.

Description

A kind of supply line protective circuit
Technical field
The present invention relates to technical field of relay protection, relate in particular to a kind of supply line protective circuit.
Background technology
When the load that access in parallel in circuit is too much, the rated power that the bearing power in circuit will be made to exceed electric wire can bear, the load resistance between live wire and zero line is too small, and this will cause electric current in circuit excessive, and power consumption equipment is generated heat.Circuit transships for a long time and can reduce line insulation level, even burning apparatus or circuit.And if the live wire of load in circuit contacts with zero line, low-resistivity short circuit between live wire and zero line, will be short-circuited, be equivalent to power supply and directly connect into closed-loop path by Live line Zero line without load, serious words can cause circuit because electric current excessive and burn and breaking out of fire.To transship or short circuit is all fault that is serious and that should avoid as far as possible.
In prior art, the overload in circuit and short trouble just can only detect after energising of closing a floodgate to load.If there occurs short circuit or overload after load energising, the inside tripping mechanism of circuit breaker can perform an action, and makes load deenergization.In order to protect load, if generally there is overload after energising is closed a floodgate in load, need load delay cut-off, and when short circuit, because the electric current in power supply circuits much larger than electric current during overload, then needs load power-off at once.And be difficult to precisely to control to realize the delay cut-off of load when transshipping in prior art and in short circuit time momentary power failure, also the situation whether load exists overload or short circuit cannot be detected before energising of closing a floodgate, if but just there is the situation of overload or short circuit in load before energising of closing a floodgate, also the i.e. too small or low-resistivity short circuit between live wire and zero line of load resistance between live wire and zero line, then big current will be produced in close a floodgate moment of energising of load in circuit, if actuator breaks down again, likely can burning apparatus even initiation fire.
Summary of the invention
For this reason, technical problem to be solved by this invention be to be difficult in prior art precisely to control to realize the delay cut-off of load when transshipping and in short circuit time momentary power failure.
For solving the problems of the technologies described above, technical scheme of the present invention is as follows:
The invention provides a kind of supply line protective circuit, comprising:
Current transformer, the live wire of described supply line passes from the magnet ring of described current transformer;
Rectification unit, is converted to direct voltage for the induced current produced by the coil of described current transformer;
Detecting unit, obtains direct voltage from described rectification unit, when overload or short circuit do not occur in described supply line, exports the first level; When overload occurs in described supply line, time delay exports second electrical level, when described power supply detection line is short-circuited, exports second electrical level immediately;
Protected location, for when described detecting unit exports the first level, controls described supply line and keeps conducting, when described detecting unit exports second electrical level, controls described supply line and disconnects.
Supply line of the present invention protective circuit, described rectification unit comprises the first resistance R11 and rectifier bridge;
The two ends of described first resistance R11 couple with the coil two ends of described current transformer and the input of described rectifier bridge simultaneously, and the output of described rectifier bridge is the output of described rectification unit.
Supply line of the present invention protective circuit, described detecting unit comprises the first voltage-stabiliser tube W1, the second voltage-stabiliser tube W2, the first diode D1, the second diode D2 and the first electric capacity C2;
The positive pole of the described negative electrode of the first voltage-stabiliser tube W1 and the output of described rectification unit couples, the anode of described first voltage-stabiliser tube W1 couples with the positive pole of the negative electrode of described second voltage-stabiliser tube W2, one end of described first electric capacity C2 and described second diode D2 respectively, the other end ground connection of described first electric capacity C2, the anode of described second voltage-stabiliser tube W2 and the positive pole of described first diode D1 couple, and the negative pole of described second diode D2 and the negative pole of described first diode D1 couple;
When overload occurs in described supply line, described first voltage-stabiliser tube W1 is breakdown, and described second voltage-stabiliser tube W2 is not breakdown; When described supply line is short-circuited, described first voltage-stabiliser tube W1 and described second voltage-stabiliser tube W2 is all breakdown;
The common port that negative pole and the negative pole of described first diode D1 of described second diode D2 couple mutually is the output of described detecting unit.
Supply line of the present invention protective circuit, the puncture voltage of described second voltage-stabiliser tube W2 is 3-5 times of the puncture voltage of described first voltage-stabiliser tube W1.
Supply line of the present invention protective circuit, described protected location comprises:
Control subelement; after described detecting unit exports the first level, control to perform subelement remain closed; described supply line is made to keep conducting; otherwise described control subelement controls described execution subelement to be disconnected; described supply line is disconnected, and the input of described control subelement is the input of described protected location.
Supply line of the present invention protective circuit, described execution subelement comprises the first magnetic latching relay and the second magnetic latching relay;
The normally opened contact of described first magnetic latching relay is connected into live wire, the normally opened contact of described second magnetic latching relay is connected into zero line, and the control end of described first magnetic latching relay and the control end of described second magnetic latching relay couple with two outputs of described control subelement respectively.
Supply line of the present invention protective circuit, also comprises:
Previewing unit, for live wire and the zero line of the described supply line of access before load energising, when overload or short circuit do not occur in described supply line, exports the first level; Second electrical level is exported when overload or short circuit occur in described supply line;
Described protected location, when described previewing unit exports the first level, controls the conducting of described supply line, when described previewing unit exports second electrical level, controls described supply line and remains open.
Supply line of the present invention protective circuit, described previewing unit comprises the first controllable silicon T2, the first switch, second switch and the 3rd switch;
The positive pole of described first controllable silicon T2 connects high level after described first switch, the control pole of described first controllable silicon T2 couples with described live wire after described second switch, the minus earth of described first controllable silicon T2, described zero line is by ground connection after described 3rd switch;
The positive pole of described first controllable silicon T2 is the output of described previewing unit.
Supply line of the present invention protective circuit, described first switch, described second switch and described 3rd switch are relay;
Described preliminary examination circuit also comprises the first control unit U1 and the second control unit U2, and described second control unit U2 controls described first control unit U1 to be carried out conducting or turn off described first switch, described second switch and described 3rd switch.
Supply line of the present invention protective circuit, also comprises:
Reverse unit, the output of its input and described detecting unit and the output of described previewing unit couple, and the input of its output and described protected location couples;
When described detecting unit or described previewing unit export the first level; described reverse unit is to described protected location input second electrical level; when described detecting unit or described previewing unit export second electrical level, described reverse unit inputs the first level to described protected location.
Supply line of the present invention protective circuit; described reverse unit comprises the second controllable silicon T1; the positive pole of described second controllable silicon T1 connects high level; the control pole of described second controllable silicon T1 and the positive pole of described first controllable silicon T2, the negative pole of described first diode D1 and the negative pole of described second diode D2 couple; the minus earth of described second controllable silicon T1, the positive pole of described second controllable silicon T1 is the output of described reverse unit.
Technique scheme of the present invention has the following advantages compared to existing technology:
The invention provides a kind of supply line protective circuit, comprise current transformer, the live wire of supply line passes from the magnet ring of current transformer; Rectification unit, is converted to direct voltage for the induced current produced by the coil of current transformer; Detecting unit, obtains direct voltage from rectification unit, when overload or short circuit do not occur in supply line, exports the first level; When overload occurs in supply line, time delay exports second electrical level, when detection line of powering is short-circuited, exports second electrical level immediately; Protected location, for when detecting unit exports the first level, controls supply line and keeps conducting, when detecting unit exports second electrical level, controls supply line and disconnects.Because detecting unit time delay when overload occurs in supply line exports second electrical level; protected location also time delay will detect that detecting unit outputs second electrical level; thus disconnect in the time delay of generation overload Shi Shi supply line; and detecting unit can export second electrical level at once when supply line is short-circuited; protected location also can detect that detecting unit outputs second electrical level immediately; thus disconnect immediately in the Shi Shi supply line that is short-circuited, precisely can control to realize the delay cut-off of load when transshipping and in short circuit time momentary power failure.
Accompanying drawing explanation
In order to make content of the present invention be more likely to be clearly understood, below according to a particular embodiment of the invention and by reference to the accompanying drawings, the present invention is further detailed explanation, wherein
Fig. 1 is the structured flowchart of supply line of the present invention protective circuit;
Fig. 2 is the circuit theory diagrams of supply line of the present invention protective circuit.
In figure, Reference numeral is expressed as: 11-current transformer, 12-rectification unit, 13-detecting unit, 14-protected location; 15-previewing unit, the reverse unit of 16-, 121-rectifier bridge, 141-controls subelement; 142-performs subelement, 151-first switch, 152-second switch, 153-the 3rd switch.
Embodiment
Present embodiments provide a kind of supply line protective circuit, as shown in Figure 1, comprise: current transformer 11, rectification unit 12, detecting unit 13 and protected location 14, the live wire of described supply line passes from the magnet ring of described current transformer 11, rectification unit 12 is converted to direct voltage for the induced current produced by the coil of described current transformer 11, detecting unit 13, direct voltage is obtained from described rectification unit 12, when overload or short circuit do not occur in described supply line, export the first level; When there is overload in described supply line; time delay exports second electrical level; when described power supply detection line is short-circuited; export second electrical level immediately; protected location 14, when described detecting unit 13 exports the first level, controls described supply line and keeps conducting; when described detecting unit 13 exports second electrical level, control described supply line and disconnect.
Particularly, when there is overload or short circuit in supply line, electric current in supply line can increase instantaneously, now the coil of current transformer 11 will produce induced current, and the induced current that the coil of current transformer 11 produces can be converted to direct voltage and be supplied to detecting unit 13 by rectification unit 12.Because detecting unit 13 time delay when overload occurs in supply line exports second electrical level, protected location 14 also time delay will detect that detecting unit 13 outputs second electrical level, thus disconnect in the time delay of generation overload Shi Shi supply line, and detecting unit 13 can export second electrical level at once when supply line is short-circuited, protected location 14 also can detect that detecting unit 13 outputs second electrical level immediately, thus disconnect immediately in the Shi Shi supply line that is short-circuited, make protected location 13 precisely can control to realize the delay cut-off of load when transshipping and in short circuit time momentary power failure, infringement is down to minimum.
Preferably, as shown in Figure 2, described rectification unit 12 can comprise the first resistance R11 and rectifier bridge 121;
The two ends of described first resistance R11 couple with the coil two ends of described current transformer 11 and the input of described rectifier bridge 121 simultaneously, and the output of described rectifier bridge 121 is the output of described rectification unit 12.Alternating current just becomes galvanic current pressure after the rectification process of the first resistance R11 dividing potential drop and rectifier bridge 121, ensure that the stable operation of detecting unit 13 and protected location 14.
Particularly, induced current on the coil of current transformer 11 flows through the first resistance R11, first resistance R11 will produce induced voltage, through the rectification of rectifier bridge 121, will output dc voltage, preferably, as shown in Figure 2, filtering can be carried out at output termination electric capacity C1 of rectifier bridge 121, will the direct voltage of stable output.
Preferably, as shown in Figure 2, described detecting unit 13 can comprise the first voltage-stabiliser tube W1, second voltage-stabiliser tube W2, first diode D1, second diode D2 and the first electric capacity C2, the positive pole of the described negative electrode of the first voltage-stabiliser tube W1 and the output of described rectification unit 12 couples, the anode of described first voltage-stabiliser tube W1 respectively with the negative electrode of described second voltage-stabiliser tube W2, one end of described first electric capacity C2 and the positive pole of described second diode D2 couple, the other end ground connection of described first electric capacity C2, the anode of described second voltage-stabiliser tube W2 and the positive pole of described first diode D1 couple, the negative pole of described second diode D2 and the negative pole of described first diode D1 couple, when there is overload in described supply line, described first voltage-stabiliser tube W1 is breakdown, and described second voltage-stabiliser tube W2 is not breakdown, when described supply line is short-circuited, described first voltage-stabiliser tube W1 and described second voltage-stabiliser tube W2 is all breakdown, and the common port that negative pole and the negative pole of described first diode D1 of described second diode D2 couple mutually is the output of described detecting unit 13.
Particularly, when there is overload in supply line, only have the first voltage-stabiliser tube W1 breakdown, and the second voltage-stabiliser tube W2 is not breakdown, now, as shown in Figure 2, the direct voltage that rectifier bridge 121 exports charges to after the first voltage-stabiliser tube W1 the first electric capacity C2, when charging time delay is to certain state, voltage on first electric capacity C2 just can reach the magnitude of voltage of second electrical level after the second diode D2, now protected location 14 just time delay can detect that detecting unit 13 exports second electrical level (high level), and then controls supply line's time delay disconnection when there is overload, when supply line is short-circuited, first voltage-stabiliser tube W1 and the second voltage-stabiliser tube W2 is all breakdown, the direct voltage that now rectifier bridge 121 exports directly exports second electrical level (high level) through the first diode D1 after the first voltage-stabiliser tube W1 and the second voltage-stabiliser tube W2, protected location 14 will detect that detecting unit 13 outputs second electrical level (high level) immediately, and then control supply line disconnects immediately when being short-circuited, when there is not overload or short circuit in supply line, first voltage-stabiliser tube W1 and the second voltage-stabiliser tube W2 all ends, with earth terminal equipotential, detecting unit 13 exports the first level (low level), what protected location 14 detected that detecting unit 13 exports is the first level, control supply line to continue to keep conducting, achieve supply line transship time delay cut-off and in short circuit time momentary power failure
Preferably, the puncture voltage of described second voltage-stabiliser tube W2 can be 3-5 times of the puncture voltage of described first voltage-stabiliser tube W1.Ensure that the first voltage-stabiliser tube W1 is breakdown, and the second voltage-stabiliser tube W2 is not breakdown when overload occurs in supply line; When supply line is short-circuited, the first voltage-stabiliser tube W1 and the second voltage-stabiliser tube W2 is all breakdown, can precisely control to make supply line's delay cut-off when transshipping, the momentary power failure when short circuit.
Preferably, as shown in Figure 1 and Figure 2, described protected location 14 can comprise:
Control subelement 141; after described detecting unit 13 exports the first level, control to perform subelement 142 remain closed; described supply line is made to keep conducting; otherwise described control subelement 141 controls described execution subelement 142 to be disconnected; described supply line is disconnected, and the input of described control subelement 141 is the input of described protected location 14, can respond fast when there is overload or short circuit; control to perform subelement 142 to disconnect, ensure that the safe operation of circuit.
Preferably, described execution subelement 142 can comprise the first magnetic latching relay and the second magnetic latching relay;
The normally opened contact of described first magnetic latching relay is connected into live wire, the normally opened contact of described second magnetic latching relay is connected into zero line, and the control end of described first magnetic latching relay and the control end of described second magnetic latching relay couple with two outputs of described control subelement 141 respectively.
Particularly, after control subelement 141 detects that detecting unit 13 exports the first level, can to the control end of the first magnetic latching relay and the control end sending controling instruction of the second magnetic latching relay, the normally opened contact of the normally opened contact and the second magnetic latching relay that control the first magnetic latching relay continues to remain closed, and makes described supply line keep conducting; And after control subelement 141 detects that detecting unit 13 exports second electrical level, can to the control end of the first magnetic latching relay and the control end sending controling instruction of the second magnetic latching relay, the normally opened contact of the first magnetic latching relay and the normally opened contact of the second magnetic latching relay are disconnected, make load and cannot loop be formed between live wire L, zero line N, supply line is just disconnected naturally, and response quick and precisely.
Preferably, the supply line's protective circuit described in the present embodiment, as shown in Figure 1, can also comprise:
Previewing unit 15, for live wire and the zero line of the described supply line of access before load energising, when overload or short circuit do not occur in described supply line, exports the first level; Second electrical level is exported when overload or short circuit occur in described supply line; described protected location 14, when described previewing unit 15 exports the first level, controls the conducting of described supply line; when described previewing unit 15 exports second electrical level, control described supply line and remain open.
Particularly; pass through previewing unit; before can detecting load energising, whether supply line there is overload or short circuit; if supply line there occurs overload or short circuit; protected location 14 can control supply line to be continued to remain open; can not power to the load, avoid the fault that causes of being energized of still closing a floodgate when supply line there occurs overload or short circuit, be conducive to the safe operation of equipment.
Preferably, as shown in Figure 1 and Figure 2, described previewing unit 15 can comprise the first controllable silicon T2, the first switch 151, second switch 152 and the 3rd switch 153, the positive pole of described first controllable silicon T2 connects high level after described first switch 151, the control pole of described first controllable silicon T2 couples with described live wire after described second switch 152, the minus earth of described first controllable silicon T2, described zero line is by ground connection after described 3rd switch 153, and the positive pole of described first controllable silicon T2 is the output of described previewing unit 15.
Particularly, before energising is closed a floodgate in load, first switch 151, second switch 152 and the 3rd switch 153 close, previewing unit 15 comes into operation, and now the positive pole of the first controllable silicon T2 connects high level, certainly in actual applications, in order to protect controllable silicon, also can connect between silicon controlled positive pole and high level some resistance, as shown in Figure 2, the positive pole of the first controllable silicon T2 can connect high level again after resistance R1; The control pole of the first controllable silicon T2 also can by connecting with live wire after some resistance again.When there is not overload or short circuit in supply line, voltage on live wire L is through the after-applied control pole at the first controllable silicon T2 of some electric resistance partial pressures, the trigger voltage being enough to reach the first controllable silicon T2 carrys out triggering and conducting first controllable silicon T2, after first controllable silicon T2 conducting, high level is through the first switch 151, the positive pole of the first controllable silicon T2, ground connection after the negative pole of resistance R1 and the first controllable silicon T2, the now just very low level of the first controllable silicon T2, because the positive pole of the first controllable silicon T2 is the output of previewing unit 15, therefore when overload or short circuit do not occur in supply line, previewing unit 15 exports the first level (low level), what protected location 14 detected that previewing unit 15 exports is the first level, supply line's conducting will be controlled, close a floodgate to load and be energized, control accurately, response rapidly.
When there is overload or short circuit in supply line, load between live wire L and zero line N is very little, near short circuit, the voltage that now live wire L is supplied to the control pole of the first controllable silicon T2 is dragged down, the first controllable silicon T2 cannot be triggered, first controllable silicon T2 is ended, the now just very high level of the first controllable silicon T2, therefore when overload or short circuit occur in supply line, previewing unit 15 exports second electrical level (high level), what protected location 14 detected that previewing unit 15 exports is second electrical level, supply line will be controlled remain open, do not close a floodgate to load and be energized, control precisely, avoid misoperation, ensure that the safe operation of circuit.
Preferably, as shown in Figure 2, described first switch 151, described second switch 152 and described 3rd switch 153 can be relay, described preliminary examination circuit 15 can also comprise the first control unit U1 and the second control unit U2, and described second control unit U2 controls described first control unit U1 to be carried out conducting or turn off described first switch 151, described second switch 152 and described 3rd switch 153.Be convenient to control, response rapidly, can realize the input of preliminary examination circuit 15 easily and cut out.
Particularly, as shown in Figure 2, the second control unit U2 can be single-chip microcomputer, and the first control unit U1 can be relay driving chip ULN2003.Relay J DQ1 selected by first switch 151, second switch 152 and the 3rd switch 153 can share the relay J DQ2 with two normally opened contacts, the relay that can certainly have a normally opened contact with two replaces relay J DQ2, circuit can be simplified further connect, reduce the space that circuit takies.
When whether needs preliminary examination supply line there is overload or short circuit, second control unit U2 can control the pin 15 of the first control unit U1, pin 16 output low level, the pin 2 of the relay J DQ1 be connected electrically, the pin 2 of relay J DQ2 is also low level, now, coil between the pin 1 of relay J DQ1 and pin 2 and the coil electricity between the pin 1 of relay J DQ2 and pin 2, make the normally opened contact between the pin 3 of relay J DQ1 and pin 4, normally opened contact between the pin 3 of relay J DQ2 and pin 4 and the normally opened contact adhesive between the pin 5 of relay J DQ2 and pin 6, be equivalent to the first switch 151, second switch 152 and the 3rd switch 153 conducting, respond very fast.
Preferably, the supply line's protective circuit described in the present embodiment, as shown in Figure 1, can also comprise:
Reverse unit 16; the output of its input and described detecting unit 13 and the output of described previewing unit 15 couple; the input of its output and described protected location 14 couples; when described detecting unit 13 or described previewing unit 15 export the first level; described reverse unit 16 inputs second electrical level to described protected location 14; when described detecting unit 13 or described previewing unit 15 export second electrical level, described reverse unit 16 inputs the first level to described protected location 14.Can misoperation be avoided, make control more accurate.
Preferably, as shown in Figure 2, described reverse unit 16 can comprise the second controllable silicon T1, the positive pole of described second controllable silicon T1 connects high level, the control pole of described second controllable silicon T1 and the positive pole of described first controllable silicon T2 couple, the minus earth of described second controllable silicon T1, the positive pole of described second controllable silicon T1 is the output of described reverse unit 16.
Particularly, when detecting unit 13 or previewing unit 15 export second electrical level (high level) (negative pole of the positive pole of the first controllable silicon T2 or the negative pole of the first diode D1 or the second diode D2 exports high level), show that supply line there occurs short circuit or overload, because the positive pole of the control pole of the second controllable silicon T1 and the first controllable silicon T2, the negative pole of the first diode D1 and the negative pole of the second diode D2 couple (in embody rule, in order to protect the second controllable silicon T1, the positive pole of the first controllable silicon T2, the negative pole of the first diode D1 and the negative pole of the second diode D2 can be electrically connected with the control pole of the second controllable silicon T1 by after resistance R7 again), it is also now high level, second controllable silicon T1 triggering and conducting, because the minus earth of the second controllable silicon T1, the positive pole of the second controllable silicon T1 is now low level, therefore, reverse unit 16 is when detecting unit 13 or previewing unit 15 export second electrical level (high level), the first level (low level) can be exported to protected location 14, after protected location 14 receives first level (low level) of reverse unit 16 input, what will judge that detecting unit 13 or previewing unit 15 export is second electrical level (high level), supply line there occurs short circuit or overload, supply line should be controlled remain open or disconnect, otherwise, when detecting unit 13 or previewing unit 15 export the first level (low level), the control pole of the second controllable silicon T1 can not reach trigger voltage, second controllable silicon T1 ends, now, the just very high level of the second controllable silicon T1, because the minus earth of the second controllable silicon T1, the positive pole of the second controllable silicon T1 is now low level, therefore, reverse unit 16 is when detecting unit 13 or previewing unit 15 export the first level (low level), second electrical level (high level) can be exported to protected location 14, after protected location 14 receives the second electrical level (high level) of reverse unit 16 input, what will judge that detecting unit 13 or previewing unit 15 export is the first level (low level), supply line is not short-circuited or transships, supply line should be controlled close or remain closed.By increasing reverse unit 16, further can strengthen the accuracy that supply line's protective circuit controls, preventing erroneous judgement.
Supply line's protective circuit described in the present embodiment; by detecting unit 13, whether can there occurs overload or short circuit to supply line's on-line checkingi, and supply line's time delay when there is overload can be made to disconnect; disconnecting immediately when being short-circuited, will be down to minimum to the infringement of equipment and circuit.By previewing unit 15, just can detect supply line before energising is closed a floodgate in load, judge whether supply line exists overload or short circuit, avoiding closes a floodgate be energized rear transship or short-circuit conditions to the damage of equipment and circuit.The voltage exported by reverse unit 16 pairs of detecting units 13 and previewing unit 15 carries out anti-phase process, enhances the accuracy of judgement, avoids the generation of erroneous judgement.
Obviously, above-described embodiment is only for clearly example being described, and the restriction not to execution mode.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all execution modes.And thus the apparent change of extending out or variation be still among the protection range of the invention.

Claims (11)

1. supply line's protective circuit, is characterized in that, comprising:
Current transformer (11), the live wire of described supply line passes from the magnet ring of described current transformer (11);
Rectification unit (12), is converted to direct voltage for the induced current produced by the coil of described current transformer (11);
Detecting unit (13), obtains direct voltage from described rectification unit (12), when overload or short circuit do not occur in described supply line, exports the first level; When overload occurs in described supply line, time delay exports second electrical level, when described power supply detection line is short-circuited, exports second electrical level immediately;
Protected location (14), for when described detecting unit (13) exports the first level, controls described supply line and keeps conducting, when described detecting unit (13) exports second electrical level, controls described supply line and disconnects.
2. supply line according to claim 1 protective circuit, is characterized in that, described rectification unit (12) comprises the first resistance (R11) and rectifier bridge (121);
The two ends of described first resistance (R11) couple with the coil two ends of described current transformer (11) and the input of described rectifier bridge (121) simultaneously, and the output of described rectifier bridge (121) is the output of described rectification unit (12).
3. the supply line's protective circuit according to right 1, it is characterized in that, described detecting unit (13) comprises the first voltage-stabiliser tube (W1), the second voltage-stabiliser tube (W2), the first diode (D1), the second diode (D2) and the first electric capacity (C2);
The positive pole of the negative electrode of described first voltage-stabiliser tube (W1) and the output of described rectification unit (12) couples, the anode of described first voltage-stabiliser tube (W1) respectively with the negative electrode of described second voltage-stabiliser tube (W2), one end of described first electric capacity (C2) and the positive pole of described second diode (D2) couple, the other end ground connection of described first electric capacity (C2), the anode of described second voltage-stabiliser tube (W2) and the positive pole of described first diode (D1) couple, the negative pole of described second diode (D2) and the negative pole of described first diode (D1) couple,
When overload occurs in described supply line, described first voltage-stabiliser tube (W1) is breakdown, and described second voltage-stabiliser tube (W2) is not breakdown; When described supply line is short-circuited, described first voltage-stabiliser tube (W1) and described second voltage-stabiliser tube (W2) all breakdown;
The common port that negative pole and the negative pole of described first diode (D1) of described second diode (D2) couple mutually is the output of described detecting unit (13).
4. supply line according to claim 3 protective circuit, is characterized in that, the puncture voltage of described second voltage-stabiliser tube (W2) is 3-5 times of the puncture voltage of described first voltage-stabiliser tube (W1).
5. the supply line's protective circuit according to right 1, is characterized in that, described protected location (14) comprising:
Control subelement (141); after described detecting unit (13) exports the first level, control to perform subelement (142) remain closed; described supply line is made to keep conducting; otherwise described control subelement (141) controls the disconnection of described execution subelement (142); described supply line is disconnected, and the input of described control subelement (141) is the input of described protected location (14).
6. supply line according to claim 5 protective circuit, is characterized in that, described execution subelement (142) comprises the first magnetic latching relay and the second magnetic latching relay;
The normally opened contact of described first magnetic latching relay is connected into live wire, the normally opened contact of described second magnetic latching relay is connected into zero line, and the control end of described first magnetic latching relay and the control end of described second magnetic latching relay couple with two outputs of described control subelement (141) respectively.
7. supply line according to claim 1 protective circuit, is characterized in that, also comprise:
Previewing unit (15), for live wire and the zero line of the described supply line of access before load energising, when overload or short circuit do not occur in described supply line, exports the first level; Second electrical level is exported when overload or short circuit occur in described supply line;
Described protected location (14), when described previewing unit (15) exports the first level, controls the conducting of described supply line, when described previewing unit (15) exports second electrical level, controls described supply line and remains open.
8. supply line according to claim 7 protective circuit, it is characterized in that, described previewing unit (15) comprises the first controllable silicon (T2), the first switch (151), second switch (152) and the 3rd switch (153);
The positive pole of described first controllable silicon (T2) connects high level after described first switch (151), the control pole of described first controllable silicon (T2) couples with described live wire after described second switch (152), the minus earth of described first controllable silicon (T2), described zero line is by described 3rd switch (153) ground connection afterwards;
The positive pole of described first controllable silicon (T2) is the output of described previewing unit (15).
9. supply line according to claim 8 protective circuit, is characterized in that, described first switch (151), described second switch (152) and described 3rd switch (153) are relay;
Described preliminary examination circuit (15) also comprises the first control unit (U1) and the second control unit (U2), and described second control unit (U2) controls described first control unit (U1) and carrys out conducting or turn off described first switch (151), described second switch (152) and described 3rd switch (153).
10. supply line according to claim 7 protective circuit, is characterized in that, also comprise:
Reverse unit (16), the output of its input and described detecting unit (13) and the output of described previewing unit (15) couple, and the input of its output and described protected location (14) couples;
When described detecting unit (13) or described previewing unit (15) export the first level; described reverse unit (16) is to described protected location (14) input second electrical level; when described detecting unit (13) or described previewing unit (15) export second electrical level, described reverse unit (16) inputs the first level to described protected location (14).
11. supply line according to claim 10 protective circuits, it is characterized in that, described reverse unit (16) comprises the second controllable silicon (T1), the positive pole of described second controllable silicon (T1) connects high level, the control pole of described second controllable silicon (T1) and the positive pole of described first controllable silicon (T2), the negative pole of described first diode (D1) and the negative pole of described second diode (D2) couple, the minus earth of described second controllable silicon (T1), the positive pole of described second controllable silicon (T1) is the output of described reverse unit (16).
CN201410764254.0A 2014-12-11 2014-12-11 A kind of supply line's protection circuit Active CN104410055B (en)

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CN106711922A (en) * 2017-02-17 2017-05-24 中领世能(天津)科技有限公司 Electrical shock protection device and power supply system
CN106711923A (en) * 2017-02-17 2017-05-24 中领世能(天津)科技有限公司 Isolation protection device and power supply system
CN108695955A (en) * 2018-05-15 2018-10-23 重庆国翰能源发展有限公司 A kind of charge protection device
CN113767444A (en) * 2019-03-25 2021-12-07 大众汽车股份公司 Electric safety device, method for operating an electric safety device and traction network

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CN101685959A (en) * 2008-09-27 2010-03-31 湖南欧美加昇科技发展有限公司 Electrical intelligent fire disaster protector
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CN2453568Y (en) * 2000-11-21 2001-10-10 胡本玉 Electric power supply plug for preventing it from being leakage, over-voltage, over-load, short circuit and lightninhg-stroke
CN101685959A (en) * 2008-09-27 2010-03-31 湖南欧美加昇科技发展有限公司 Electrical intelligent fire disaster protector
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CN106711922A (en) * 2017-02-17 2017-05-24 中领世能(天津)科技有限公司 Electrical shock protection device and power supply system
CN106711923A (en) * 2017-02-17 2017-05-24 中领世能(天津)科技有限公司 Isolation protection device and power supply system
CN108695955A (en) * 2018-05-15 2018-10-23 重庆国翰能源发展有限公司 A kind of charge protection device
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