CN201666933U - Electrode insulation detecting device for three-phase AC electric arc furnace - Google Patents
Electrode insulation detecting device for three-phase AC electric arc furnace Download PDFInfo
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- CN201666933U CN201666933U CN201020165916XU CN201020165916U CN201666933U CN 201666933 U CN201666933 U CN 201666933U CN 201020165916X U CN201020165916X U CN 201020165916XU CN 201020165916 U CN201020165916 U CN 201020165916U CN 201666933 U CN201666933 U CN 201666933U
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Abstract
The utility model discloses an electrode insulation detecting device for a three-phase AC electric arc furnace, wherein the electrode insulation detecting device comprises an AC transformer. A Secondary side of the AC transformer is respectively provided with a test winding and a control winding. A test unit is in serial connection with the test winding and an input end of the test unit is respectively connected with an electrode arm and a grounded part. A control unit is in serial connection with the control winding and an input end of the control unit is connected with an output end of the test unit for receiving detection signals. An output end of the control unit is respectively connected with a primary side of the AC transformer and with the test unit, for outputting control signals. In this way, during the interval when the electric furnace stops producing to undergo maintenance or when the power is off and the smelting is stopped, a detection of electrode ground insulation can be conducted rapidly. In addition, the detection can be performed under the situation when a cooling water valve of a water cooled cable is not shut off, that is, when the water cooled cable is in the water-through state. An earth fault can be detected by the method that heavy current flows through the ground point of a detected device.
Description
Technical field
The utility model relates to three-phase ac electric arc furnace electrode insulation detection technique over the ground, more particularly relates to a kind of electrode insulation pick-up unit of three-phase ac electric arc furnace.
Background technology
In the smelting process of iron and steel, three-phase ac electric arc furnace is one of equipment of using always.Three electric-pole horizontal arms of three-phase ac electric arc furnace are fixedly mounted on three electrode masts, as shown in Figure 1, one end of electric-pole horizontal arm 1 is connecting hydraulic oil pipe, is being arranged on the water-cooled cable 2 in the cooling water pipe, and its other end installing electrodes clamper, electrode 3 are fixed by electrode jaw; The electric current of super high power transformer 4 secondary sides is by water-cooled cable 2, electric-pole horizontal arm 1, electrode 3, steel scrap or molten iron formation loop between phase and phase, the flame current when forming electrode 3 smeltings.The shell of electrode mast 5 and electric furnace 6 all links to each other with the earth, therefore electric-pole horizontal arm 1 must insulate with electrode mast 5, in case the insulation breakdown between a certain phase electric-pole horizontal arm 1 and the electrode mast 5, flame current will cause infringement to equipment such as electrode mast 5, electric furnace 6 shells, also can cause next-door neighbour's electric furnace personnel's personal injury when serious.In order to prevent the infringement of flame current to equipment, take insulcrete 7 to isolate between electric-pole horizontal arm 1 and the electrode mast 5, this insulcrete 7 is main things that rely on of electrode insulation against ground.Because electrode 3 insulating property over the ground are most important for electric furnace 6, therefore must regularly detect.And there is electrode grounding fault automatic protection functions in the electrode regulating system of three-phase ac electric arc furnace.Its protection philosophy is as follows: go out the wall place at the short net of transformer 4 secondaries that connect water-cooled cable 2 and draw three detection streamers 8 and enter a voltage detecting case 9; 8 samplings of this three detection streamers be exactly three-phase electrode voltage, control system is delivered in isolation, the conversion coupling of three detection transformers by T01-T03 among Fig. 2.See also shown in Figure 3 again; smelt when preparing; transformer was subjected to after high-pressure vacuum breaker Q0 closed a floodgate; secondary side has voltage; in case the insulation against ground of a certain phase damages; the voltage that the detection transformer samples is very little or approach zero; when the operative employee starts the automatic mode smelting; ground connection phase electrode is refused to descend under the protection of control system; can see that on the instrument of furnace operation platform electrode voltage corresponding to ground connection phase is very little or approach zero; as long as the operative employee does not switch to manual smelting pattern and with smeltings that descend by force of the electrode of ground connection phase, equipment does not just have injury.Because the secondary side of super high power three-phase transformer adopts delta connection, the isolating transformer that is equivalent to a super high power, between secondary side phase line and the electric furnace system earth point without any electric loop, even therefore a certain phase electrode insulation damages over the ground, as long as this phase electrode does not participate in smelting, just do not have electric current between electrode and the electric furnace system earth point.
The insulation over the ground of prior art bottom electrode detects adopts the megohmmeter detection method, yet because an end of electric-pole horizontal arm is connecting water-cooled cable, all leading to chilled water in water-cooled cable and the electric-pole horizontal arm, chilled water is a kind of conducting objects, therefore can't detect insulating property, even cooling water valve turn-offed and when detecting with megohmmeter after the remaining chilled water emptying in water-cooled cable and the electric-pole horizontal arm, near the megohmmeter pointer still points to zero (less than 0.1 megaohm), reason is the still moist cause in water-cooled cable inside.And to really detect electrode insulating property over the ground under the prior art must wait until the electric furnace stop production to overhaul time, water-cooled cable, cooling water pipe, hydraulic oil pipe that electric-pole horizontal arm one end connects are removed, therefore this kind detection all is to run at electric furnace great overhauling project is arranged generally speaking, as just implement when changing electric-pole horizontal arm or water-cooled cable, be difficult to control at ordinary times, can do also only be each stop production to overhaul the time to the cleaning of insulcrete.Yet, search fault in case just require a great deal of time when problem has taken place in the electrode insulation against ground, when if problem occurs on the insulcrete that is serving as a contrast below the electric-pole horizontal arm, at first need scaffolding, remove respectively being connected of water-cooled cable, cooling water pipe, hydraulic oil pipe and electric-pole horizontal arm then; Then hang away the electrode of the electrode transverse arm other end, tens tons the electric-pole horizontal arm of weighing of just slinging at last, whole process is very consuming time, reaches tens hours, is a kind of major accident that has a strong impact on rhythm of production.Therefore prior art has following major defect: existing electrode grounding fault detect can only be closed a floodgate at high-pressure vacuum breaker, just can finish under the situation of electrifying electrodes.And existing detection technique is a kind of detection afterwards, it can not carry out in the gap that usual stop production to overhaul or electric furnace stop to smelt, and can only when the electric furnace energising is smelted, could detect, earth fault has taken place even detected electrode, also It dones't help the situation, because the electrode grounding fault will be handled for a long time, damaging with the electric-pole horizontal arm lower insulation plate is example, various connections, the driving handling wanting scaffolding during processing, remove electric-pole horizontal arm, the cost lot of manpower and material resources.Secondly, existing detection technique relies on earth leakage stream to detect, if a certain phase electrode grounding, earth leakage stream constitutes the loop by detection streamer and electric furnace system earth point, earth leakage stream flows through earth point, the detection transformer of T01-T03 and the current-limiting resistance of R01-R03, owing to have current-limiting resistance and detect transformer induction reactance, even therefore earth point dead ground, earth leakage stream also can not surpass 6.3 amperes of the rated current of the fuse of F01-F03, be a kind of detection that does not have big electric current to flow through measured device, have only more serious earth fault just can be detected.Moreover, existing detection technique is a kind of general insulation detection technique under the electrifying electrodes situation, after earth fault has taken place in electrode, system only be do not allow electrode descend and can not detect where fault is arranged (as insulcrete damage or water-cooled cable leak cause earth fault or the like).At last, if there is the two-phase electrode that insulation fault has all taken place over the ground, in case high-pressure vacuum breaker closes a floodgate, furnace equipment will be subjected to destructive infringement.
The utility model content
At the problem that can not judge the electrode insulation against ground of three-phase ac electric arc furnace in real time, accurately that exists in the prior art, the purpose of this utility model provides a kind of electrode insulation pick-up unit of three-phase ac electric arc furnace, can implement the detection of electrode insulation against ground apace.
To achieve these goals, the utility model adopts following technical scheme:
A kind of electrode insulation pick-up unit of three-phase ac electric arc furnace comprises:
AC transformer, the secondary side of described AC transformer are respectively equipped with test winding and control winding;
Test cell, with the test windings in series, the input end of test cell is connected with electric-pole horizontal arm and grounded parts respectively;
Control module, with the control windings in series, the input end of control module is connected with the output terminal of test cell, to receive detection signal; The output terminal of control module is connected with the primary side and the test cell of AC transformer respectively, with the output control signal.
Described test cell comprises test clip, current limiting reactor, contactor, step-up transformer and diode, test clip, current limiting reactor, contactor, step-up transformer and electric-pole horizontal arm, grounded parts, test winding constitute the loop, and the secondary side of step-up transformer is connected with the input end of diode.
Described control module comprises rectification circuit, thyristor and relay, and the output terminal of rectification circuit, thyristor, relay and control winding constitute the loop, and the gate pole of thyristor is connected with the output terminal of diode.
The two ends of described relay also connect a pilot lamp.
Compared with prior art, the electrode insulation pick-up unit of three-phase ac electric arc furnace of the present utility model has the following advantages:
1) stops to smelt the gap at general electric furnace stop production to overhaul or outage, can implement the detection of electrode insulation against ground apace.
2) can under the situation that is not related to the cold cable cooling water valve of cutting off the water supply, just under the state of water-cooled cable water flowing, detect.
3) utilize the means that big electric current flows through the measured device earth point to detect earth fault.If problem has appearred in the electrode insulation against ground of a certain phase, use method of the present invention, earth point will flow through big electric current, thereby find earth point.
4), can take sectionalization test method, thereby determine concrete ground connection position the independent test of emphasis object of suspicion if just begun can not find earth point.
Description of drawings
Fig. 1 is the structural representation of existing three-phase ac electric arc furnace;
Fig. 2 is the circuit diagram of voltage detecting case among Fig. 1;
Fig. 3 is the high-pressure system distribution figure of existing three-phase ac electric arc furnace;
Fig. 4 is the theory diagram of the electrode insulation pick-up unit of the utility model three-phase ac electric arc furnace;
Fig. 5 is the circuit diagram of the insulation detection device of Fig. 4.
Embodiment
Further specify the technical solution of the utility model below in conjunction with drawings and Examples.
See also the electrode insulation pick-up unit of Fig. 4, a kind of three-phase ac electric arc furnace shown in Figure 5, comprise AC transformer T1, the secondary side of described AC transformer T1 is respectively equipped with test winding and control winding; Test cell 11, with the test windings in series, the input end of test cell 11 is connected with electric-pole horizontal arm and grounded parts respectively, and grounded parts can be electric furnace ground wire or metallic water pipe.Control module 12, with the control windings in series, the input end of control module 12 is connected with the output terminal of test cell 11, to receive detection signal; The output terminal of control module is connected with primary side and the test cell 11 of AC transformer T1 respectively, with the output control signal.Test cell 11 comprises test clip J, current limiting reactor L1, contactor KM1, step-up transformer T2 and diode VD1, test clip J, current limiting reactor L1, contactor KM1, step-up transformer T2 and electric-pole horizontal arm, electric furnace ground wire or metallic water pipe, test winding constitute the loop, and the secondary side of step-up transformer T2 is connected with the input end of diode VD1.Control module 12 comprises rectification circuit U, thyristor VT1 and relay K 1, and the output terminal of rectification circuit U, thyristor VT1, relay K 1 and control winding constitute the loop, and the gate pole of thyristor VT1 is connected with the output terminal of diode VD1.The two ends of relay K 1 also meet a pilot lamp HL1.
Principle of work of the present utility model is as follows, and the secondary side of AC transformer T1 has two windings in the device, and one of them winding provides measuring current, is used for the realization of control function behind the rectification circuit U of the alternating voltage of another winding by bridge rectifier.Reactor L1 is the current limiting reactor of the excessive measuring current of restriction.One test clip J is clipped on any ground wire of electric furnace or the metallic water pipe, and another test clip J is clipped in set bolt 10 places that are installed in advance on the electric-pole horizontal arm shown in Figure 1.Circuit breaker Q 1 is closed a floodgate, after key selector switch S1 switches to " test ", if electrode is insulation damages over the ground, can flow through very big electric current between two test clip J, the secondary side of step-up transformer T2 can obtain an induced voltage, this induced voltage makes diode VD1 conducting and the thyristor VT1 conducting that is triggered, owing to have after the thyristor conducting when positive negative electrode and apply current attenuation that back-pressure or positive cathode system cross extremely when keeping electric current, the characteristics that thyristor just turn-offs, earth fault pilot lamp HL1 is lighted always, simultaneously, relay K 1 coil gets, the K1 normally closed contact has disconnected the loop of main contactor KM1 coil, main contactor KM1 coil blackout, and the main contacts of KM1 has cut off measuring current.After key selector switch S1 switched to " disconnection ", K1 coil, KM1 coil be dead electricity all, and thyristor VT1 turn-offs, and earth fault pilot lamp HL1 goes out, for test is next time got ready.
Implementation step of the present utility model is as follows:
1) cuts off Fig. 3 mesohigh vacuum circuit breaker Q0.
2) disconnector Q9, the grounding switch Q8 down that closes under the cutoff high have not had residual charge to guarantee electrode;
3) extract three interior fuse F01-F03 of Fig. 2 voltage detecting case, this is the key point that the present invention detects, as can be seen from Figure 2, three-phase electrode links to each other with the earth point of electrode regulating system by fuse F01-F03, resistance R 01-R03, transformer T01-T03, cuts off fuse and has just cut off being connected of electrode and system earth point.
4) because electric furnace three-phase transformer second siding ring communicates on electric and resistance is very little, so the three-phase electrode insulation against ground is done always to test.Utilize the method, we only need test the insulation situation that a certain phase just can be known the entire electrode system.
5) if find when always testing to have electrode to have earth fault and do not find earth point for the moment, can take the sectionalization test method, the emphasis object of suspicion is carried out sectionalization test.
The electrode insulation pick-up unit key distinction compared with prior art of three-phase ac electric arc furnace of the present utility model is as follows:
A) detection mode difference
Existing detection technique is a kind of detection afterwards that utilizes testing circuit to carry out under electric furnace energising smelting situation, even having detected electrode, that earth fault has taken place is also late, because get rid of the very long time of electrode grounding fault needs generally speaking, therefore generally the earth fault that is taken place after the electric furnace ordinary production be defined as ground fault.The technology of the present invention can make full use of the opportunity of electric furnace stop production to overhaul, and electrode insulation against ground situation is detected in advance, in case find have time enough to handle earth fault after there is earth fault in electrode, earth fault can not developed into ground fault.
B) detection means difference
Existing detection technique relies on earth leakage stream to detect, if a certain phase electrode grounding, earth fault constitutes the loop by detection streamer and electric furnace system earth point, the earth leakage stream that flows through earth fault is limited in the less order of magnitude, be a kind of little current detecting means that do not have big electric current to flow through measured device, have only more serious earth fault just can be detected.The technology of the present invention is utilized a pick-up unit, its essence is the electric loop that has added an energy detection of ground faults, utilize an external power supply (Circuit Fault on Secondary Transformer voltage in the device) that electrode, the earth of ground connection phase are constituted electric loop by force, thereby make earth fault flow through big electric current, the automatic testing result in testing result ratio energising back therefore of the present invention is accurate and effective more; In addition, the earth fault that has big electric current to flow through generally can be sent arclight, therefore finds earth fault in detection easily, and is very directly perceived.
C) detection method difference
Existing detection technique is a kind of general insulation detection technique under the electrifying electrodes situation, and after earth fault had taken place electrode, system can not detect earth fault and where occur in, and still needs artificial detailed inspection in the interruption maintenance of back.Comparatively speaking the technology of the present invention obviously flexibly, conveniently, in concrete test process, can do once test always to the whole three-phase electrode, can take the independent sectionalization test method of testing of emphasis object of suspicion if can not find earth fault in the problem of test and a period of time, thereby search out concrete earth fault.
Those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the purpose of this utility model, and be not with opposing qualification of the present utility model, as long as in essential scope of the present utility model, all will drop in the scope of claim of the present utility model variation, the modification of the above embodiment.
Claims (4)
1. the electrode insulation pick-up unit of a three-phase ac electric arc furnace is characterized in that, comprising:
AC transformer, the secondary side of described AC transformer are respectively equipped with test winding and control winding;
Test cell, with the test windings in series, the input end of test cell is connected with electric-pole horizontal arm and grounded parts respectively;
Control module, with the control windings in series, the input end of control module is connected with the output terminal of test cell, to receive detection signal; The output terminal of control module is connected with the primary side and the test cell of AC transformer respectively, with the output control signal.
2. insulation detection device as claimed in claim 1 is characterized in that,
Described test cell comprises test clip, current limiting reactor, contactor, step-up transformer and diode, test clip, current limiting reactor, contactor, step-up transformer and electric-pole horizontal arm, grounded parts, test winding constitute the loop, and the secondary side of step-up transformer is connected with the input end of diode.
3. insulation detection device as claimed in claim 2 is characterized in that,
Described control module comprises rectification circuit, thyristor and relay, and the output terminal of rectification circuit, thyristor, relay and control winding constitute the loop, and the gate pole of thyristor is connected with the output terminal of diode.
4. insulation detection device as claimed in claim 3 is characterized in that,
The two ends of described relay also connect a pilot lamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020165916XU CN201666933U (en) | 2010-04-20 | 2010-04-20 | Electrode insulation detecting device for three-phase AC electric arc furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201020165916XU CN201666933U (en) | 2010-04-20 | 2010-04-20 | Electrode insulation detecting device for three-phase AC electric arc furnace |
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| CN201666933U true CN201666933U (en) | 2010-12-08 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201020165916XU Expired - Fee Related CN201666933U (en) | 2010-04-20 | 2010-04-20 | Electrode insulation detecting device for three-phase AC electric arc furnace |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105099212A (en) * | 2014-05-16 | 2015-11-25 | 财团法人工业技术研究院 | Voltage booster and series type transformer device |
| CN106340827A (en) * | 2016-08-30 | 2017-01-18 | 中国冶集团有限公司 | Installation method of water cooling cable of finery |
| CN106524776A (en) * | 2016-10-19 | 2017-03-22 | 嘉峪关宏电铁合金有限责任公司 | Method for blowing out submerged arc furnace for long time to protect electrode |
| CN107276017A (en) * | 2017-06-27 | 2017-10-20 | 西安聚能装备技术有限公司 | The short net insulating monitoring and guard method and special purpose device of a kind of electroslag furnace |
| CN108594074A (en) * | 2018-04-28 | 2018-09-28 | 三电电缆股份有限公司 | A kind of cable automatic double surface gluer |
| CN108627738A (en) * | 2017-03-16 | 2018-10-09 | 宝钢特钢有限公司 | A kind of on-Line Monitor Device and monitoring method for monitoring electroslag furnace water-cooled cable |
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2010
- 2010-04-20 CN CN201020165916XU patent/CN201666933U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105099212A (en) * | 2014-05-16 | 2015-11-25 | 财团法人工业技术研究院 | Voltage booster and series type transformer device |
| CN106340827A (en) * | 2016-08-30 | 2017-01-18 | 中国冶集团有限公司 | Installation method of water cooling cable of finery |
| CN106340827B (en) * | 2016-08-30 | 2018-06-19 | 中国一冶集团有限公司 | The installation method of refining furnace water-cooled cable |
| CN106524776A (en) * | 2016-10-19 | 2017-03-22 | 嘉峪关宏电铁合金有限责任公司 | Method for blowing out submerged arc furnace for long time to protect electrode |
| CN108627738A (en) * | 2017-03-16 | 2018-10-09 | 宝钢特钢有限公司 | A kind of on-Line Monitor Device and monitoring method for monitoring electroslag furnace water-cooled cable |
| CN107276017A (en) * | 2017-06-27 | 2017-10-20 | 西安聚能装备技术有限公司 | The short net insulating monitoring and guard method and special purpose device of a kind of electroslag furnace |
| CN108594074A (en) * | 2018-04-28 | 2018-09-28 | 三电电缆股份有限公司 | A kind of cable automatic double surface gluer |
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| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20101208 Termination date: 20160420 |