CN101722347A - Thyristor welder and protecting circuit thereof - Google Patents

Thyristor welder and protecting circuit thereof Download PDF

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Publication number
CN101722347A
CN101722347A CN200810149952A CN200810149952A CN101722347A CN 101722347 A CN101722347 A CN 101722347A CN 200810149952 A CN200810149952 A CN 200810149952A CN 200810149952 A CN200810149952 A CN 200810149952A CN 101722347 A CN101722347 A CN 101722347A
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circuit
branch road
signal
fault detect
group
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CN101722347B (en
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靳占伟
安原芳道
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Panasonic Welding Systems Tangshan Co Ltd
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Tangshan Matsushita Industrial Equipment Co Ltd
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Abstract

The invention discloses a thyristor welder and a protecting circuit thereof. The protecting circuit comprises a fault detecting circuit, a detecting status judging circuit and a protection-executing control circuit, wherein the fault detecting circuit is arranged between an anode and a cathode of a thyristor of the welder, and can be discontinuously conducted when the welder normally works; the detecting status judging circuit is isolated and coupled with the fault detecting circuit, can judge the conductance status of the fault detecting circuit, and output the abnormal status signals when judging the fault detecting circuit not to have the conductance status; the protection-executing control circuit is connected with the detecting status judging circuit, can control an alternating current contactor of the welder, and is used for controlling the alternating current contactor to cut off the alternating current power on a main transformer when receiving the abnormal status signals from the detecting status judging circuit. The invention can detect the short circuit of the thyristor and the phase lack of the input, and has simple structure.

Description

A kind of silicon controlled welding machine and holding circuit thereof
Technical field
The present invention relates to the welding machine technology, relate in particular to a kind of silicon controlled welding machine and holding circuit thereof.
Background technology
Silicon controlled welding machine is generally by three-phase transformer, paralleing reactor, filter reactor, control transformer, A.C. contactor, ventilating fan, control circuit board, silicon controlled rectifier (SCR) (SCR) compositions such as (being also referred to as IGCT (thyristor)).As shown in Figure 1, the major loop of welding machine comprises A.C. contactor MS, main transformer Tr1, thyristor SCR1-6, paralleing reactor IPL, filter reactor DCL etc.Wherein main transformer is secondary is connected into the double reverse-stars type rectification circuit form of being with paralleing reactor IPL with silicon controlled rectifier (SCR) SCR1-6, can improve the utilization rate of main transformer, and filter reactor DCL can improve the output characteristics of welding machine, makes arc burning stable.
In the use of silicon controlled welding machine; the fault if its inner IGCT is short-circuited; will soon cause the main transformer scaling loss, under input phase shortage situation, use welding machine also can cause the defective of welding even the damage of welding machine, therefore be necessary these faults are detected and protect.
Generally take following guard method at IGCT short circuit in the welding machine in the prior art: the input line place in power distribution cabinet or welding machine is provided with the fusing insurance, makes its automatic fusing when electric current is excessive, reaches the protection purpose.But this mode selects to have certain problem for the specification of fusing insurance, does not excessively then have protective effect, and do cost so also can be than higher.
Provide a kind of to damaging the detection method of IGCT in international publication number is the patent of " method and apparatus of detection failure IGCT " of WO01/13487, this method voltage at its two ends when detecting IGCT work judges whether IGCT exists fault.
The patent that nearest openly international publication number is WO 2008/072387 " welds device " and discloses a kind of protective device.This protective device all is provided with voltage check device at the two ends of each road IGCT; under the normal condition; when ending, IGCT can have backward voltage; its both end voltage can become very low or is 0 after the IGCT short circuit; utilize this difference, the state of IGCT is judged by voltage check device.Have at least 1 road IGCT both end voltage very low all the time or when being 0 when voltage check device detects, can control the actuating of relay that is serially connected in the A.C. contactor control coil by signal processing circuit, thereby disconnect A.C. contactor, reach the purpose of protection.
The protective device of above-mentioned patent is realized with electronic device, uses device on the high side in the control circuit, and it is complicated that structure shows slightly, makes the possibility increase that is damaged and causes welder fault owing to device like this, and this device can not realize importing the detection and the protection of phase shortage in addition.
Prior art generally is to realize by detecting the variation that after the phase shortage input voltage value is taken place at the open-phase protection of welding machine.
Summary of the invention
The technical problem that the present invention will solve provides a kind of silicon controlled welding machine that has holding circuit, and this holding circuit can detect various faults and defencive function is provided.
The invention provides a kind of silicon controlled welding machine, comprising: main transformer; A.C. contactor is arranged on the primary side of main transformer, and being used for provides or disconnect alternating electromotive force main transformer; IGCT is arranged on the primary side of main transformer, is used for control welding output; Failure detector circuit is arranged between IGCT anode and the negative electrode, failure detector circuit intermittently conducting when the operate as normal of welding machine; The detected state decision circuitry, with the failure detector circuit isolation coupling, conducting state that can the failure judgement testing circuit, when there is not conducting state in the failure judgement testing circuit, the output abnormality status signal; Control circuit is carried out in protection, links to each other with the detected state decision circuitry, can control A.C. contactor, is used for controlling A.C. contactor when the abnormality signal that receives from the detected state decision circuitry main transformer is disconnected alternating electromotive force.
According to an embodiment of silicon controlled welding machine of the present invention, the IGCT of this welding machine has 6, is connected with secondary two group three of main transformer respectively, and these two groups of three-phases are the double reverse-stars type connection; Failure detector circuit comprises the first fault detect branch road at least, one end of this first fault detect branch road comprises 3 nodes, link to each other with the first mutually different other two-phase in first group first phase, second group respectively with in described two groups, the points of common connection of the IGCT that the other end of this first fault detect branch road links to each other with second group of three-phase links to each other; Wherein, this first group is any a group in two groups of three-phases, and first is U, V, the W any phase in mutually mutually.
According to an embodiment of silicon controlled welding machine of the present invention, failure detector circuit also comprises the second fault detect branch road; One end of this second fault detect branch road comprises 3 nodes, be different from the other two-phase that is different from second phase in described first mutually second phase, described first group and link to each other respectively with in described second group, the points of common connection of the IGCT that the other end of this second fault detect branch road links to each other with described first group of three-phase is continuous.
According to an embodiment of silicon controlled welding machine of the present invention, the above-mentioned first fault detect branch road comprises that first resistance continuous with described first, first diode and second diode, the 3rd diode that links to each other with described points of common connection and second resistance, the detection signal that link to each other with other two-phase respectively send part, the 3rd resistance; Wherein, described first resistance and first diode are parallel-connected to an end of described second resistance jointly, the other end of described second resistance and second diode are parallel-connected to described detection signal jointly and send part, and described detection signal sends part and described the 3rd resistance, the 3rd diode are connected successively; Described detection signal sends part and comprises electric capacity, photoelectrical coupler and the diode that is connected in parallel.
According to an embodiment of silicon controlled welding machine of the present invention, failure detector circuit also comprises the 3rd, the 4th fault detect branch road; Wherein, the 3rd fault detect branch road is connected across the two ends with the second described first group IGCT that is connected; The 4th fault detect branch road is connected across the two ends with the first described second group IGCT that is connected, and is used to judge whether short circuit of IGCT to be measured.
It is to be noted, two groups of secondary three-phases of main transformer are the double reverse-stars type connection, be U, V, the W three-phase is a star connection, U ', V ', W ' three-phase also is a star connection, and with U, V, W is mutually corresponding anti-phase, " first group " herein, " second group " all can refer to arbitrary group in above-mentioned two groups, three-phase in every group also can be called " first phase ", " second phase ", " third phase ", wherein " first mutually " of " first group " and " second group " all refer to have a phase of corresponding relation (as " first phase " of " first group " if refer to the U phase time, " first phase " of " second group " then refers to U ' phase), " though first group ", " second group ", " first phase ", " second phase " these contents have certain arbitrariness when referring in the text, but refer to identical group or identical phase when in close context, occurring respectively, in this special instruction, this explanation also is suitable for when hereinafter identical content occurring, no longer specified otherwise.
An embodiment according to silicon controlled welding machine of the present invention; above-mentioned detected state decision circuitry comprises that detection signal receive to handle branch road and signal mutually and circuit; detection signal receives handles branch road and the corresponding isolation coupling of above-mentioned fault detect branch road; judge signal to signal mutually and circuit according to the signal output state of fault detect branch road, signal and circuit are judged to output to after signal carries out handling with door to state and are protected the execution control circuit.
According to an embodiment of silicon controlled welding machine of the present invention, protection is carried out control circuit and is comprised: switching device, be used to receive status signal from the detected state decision circuitry, and the output protection signal is to A.C. contactor when status signal is the abnormality signal; The power supply decision circuitry links to each other with the secondary control coil of main transformer and the output of switching device, is used to detected state decision circuitry and switching device that electric power is provided; Wherein, when main transformer was not charged, the power supply decision circuitry stopped to provide electric power; When switching device output protection signal, the power supply decision circuitry provides electric power to detected state decision circuitry and switching device.
Silicon controlled welding machine provided by the invention; carry out control circuit, failure detector circuit and detected state decision circuitry by protection and constitute holding circuit; when IGCT short circuit or input phase shortage, can disconnect the supply of electric power of main transformer; for welding machine provides protection, holding circuit is simple in structure and can detect various faults.
Another technical problem that the present invention will solve provides a kind of holding circuit, and this holding circuit is simple in structure and can detect the various faults of welding machine.
The invention provides a kind of holding circuit that is used to detect welder fault, comprising: failure detector circuit is arranged between the anode and negative electrode of IGCT of welding machine the intermittently conducting when the welding machine operate as normal of this failure detector circuit; The detected state decision circuitry, with the failure detector circuit isolation coupling, conducting state that can the failure judgement testing circuit, when there is not conducting state in the failure judgement testing circuit, the output abnormality status signal; And control circuit is carried out in protection, links to each other with the detected state decision circuitry, can control the A.C. contactor of welding machine, the main transformer disconnection alternating electromotive force of control A.C. contactor butt welding machine when the abnormality signal that receives from the detected state decision circuitry.
According to an embodiment of holding circuit of the present invention, the IGCT of welding machine to be detected has 6, is connected with secondary two group three of main transformer respectively, and these two groups of three-phases are the double reverse-stars type connection; Failure detector circuit comprises the first fault detect branch road at least, one end of the first fault detect branch road comprises 3 nodes, link to each other with the first mutually different other two-phase in first group first phase, second group respectively with in two groups, the points of common connection of the IGCT that the other end of the first fault detect branch road links to each other with second group of three-phase links to each other; Wherein, first group is any a group in two groups of three-phases, and first is U, V, the W any phase in mutually mutually.
Further, the first fault detect branch road comprises that first resistance continuous with first, first diode and second diode, the 3rd diode that links to each other with points of common connection and second resistance, the detection signal that link to each other with other two-phase respectively send part, the 3rd resistance; Wherein, first resistance and first diode are parallel-connected to an end of second resistance jointly, the other end of second resistance and second diode are parallel-connected to detection signal jointly and send part, and detection signal sends part and the 3rd resistance, the 3rd diode are connected successively; This detection signal sends part and comprises electric capacity, photoelectrical coupler and the diode that is connected in parallel.
An embodiment according to holding circuit of the present invention is characterized in that, failure detector circuit also comprises second, third and the 4th fault detect branch road; Wherein, one end of the second fault detect branch road comprises 3 nodes, be different from the other two-phase that is different from second phase in first mutually second phase, described first group and link to each other respectively with in described second group, the points of common connection of the IGCT that the other end of the above-mentioned second fault detect branch road links to each other with described first group of three-phase is continuous.The 3rd fault detect branch road is connected across the two ends with the second described first group IGCT that is connected, and the 4th fault detect branch road is connected across the two ends with the first described second group IGCT that is connected, and is used to judge whether short circuit of IGCT to be measured.
An embodiment according to holding circuit of the present invention, above-mentioned protection is carried out control circuit and is comprised: switching device, be used to receive the status signal from the detected state decision circuitry, when status signal was the abnormality signal, the output protection signal was to A.C. contactor; The power supply decision circuitry, the output of carrying out control circuit with the secondary control coil and the protection of main transformer links to each other, and is used to detected state decision circuitry and switching device that electric power is provided; Wherein, when main transformer was not charged, the power supply decision circuitry stopped to provide electric power; When switching device output protection signal, the power supply decision circuitry provides electric power to detected state decision circuitry and switching device.
Holding circuit provided by the invention can disconnect the supply of electric power of main transformer when IGCT short circuit or input phase shortage, for welding machine provides protection, holding circuit is simple in structure and can detect various faults.
Description of drawings
Fig. 1 is the circuit diagram of the major loop part of welding machine;
Fig. 2 is the structure chart of an embodiment of the holding circuit of welding machine of the present invention;
Fig. 3 is the circuit diagram of the failure detector circuit of holding circuit shown in Figure 2;
Fig. 4 is the structure chart of another embodiment of the holding circuit of welding machine of the present invention;
Fig. 5 is the circuit diagram of the failure detector circuit of holding circuit shown in Figure 4;
Fig. 6 is the detected state decision circuitry of holding circuit shown in Figure 4 and the circuit diagram that control circuit is carried out in protection.
The specific embodiment
With reference to the accompanying drawings the present invention is described more fully, exemplary embodiment of the present invention wherein is described.
The basic principle that holding circuit of the present invention detects the fault of welding machine is; the mode of connection of photoelectrical coupler or relay by failure detector circuit of the present invention; select secondary 3 the specific different branch that are connected with IGCT of main transformer, detect 3 IGCTs all by and the equal particular state of existence just often of continuous No. 3 main transformer secondary voltages.If there is this particular state, the intermittently conducting of photoelectrical coupler or relay does not then have this state, photoelectrical coupler or relay not conducting all the time when IGCT short circuit or input open-phase fault.Therefore holding circuit of the present invention has two kinds of functions that detect IGCT short circuit and input open-phase fault concurrently.
Fig. 2 is the structure chart of an embodiment of the holding circuit of welding machine of the present invention.As shown in Figure 2; this holding circuit comprises failure detector circuit 21, detected state decision circuitry 22 and protection execution control circuit 23; protection is carried out control circuit 23 and is linked to each other with detected state decision circuitry 22, is connected to isolation coupling between failure detector circuit 21 and the detected state decision circuitry 22.A kind of implementation of isolation coupling is: detected state decision circuitry 22 comprises the sensitive side of photoelectrical coupler, can receive the optical signal that the emission side of the photoelectrical coupler in the failure detector circuit 21 is sent.The implementation of another isolation coupling is with relay (for example optical relay, magnetic relay) instead of optical electric coupler.Wherein, protection is carried out control circuit 23 and is used for the A.C. contactor of primary side that the output protection signal controlling is arranged on the main transformer of welding machine, main transformer is provided or disconnects alternating electromotive force by A.C. contactor control.Failure detector circuit 21 is coupling between the anode and negative electrode of IGCT of welding machine, and intermittently conducting when the operate as normal of welding machine sends signals (for example the emission side of photoelectrical coupler send optical signal) to detected state decision circuitry 22 when conducting.Detected state decision circuitry 22 receives the signal from failure detector circuit 21, conducting state that can the failure judgement testing circuit, and to protection control circuit 23 output status signals; Wherein, when detected state decision circuitry 22 detects failure detector circuit 21 and does not have conducting state; carry out control circuit 23 output abnormality status signals to protection, output protection signal controlling A.C. contactor disconnected alternating electromotive force to main transformer after protection execution control circuit 23 was received the abnormality signal.
In the circuit diagram of Fig. 3 hereinafter, Fig. 5 and Fig. 6, R represents resistance, and Q represents transistor, C represents electric capacity, and D represents diode, and ZD represents voltage-stabiliser tube, QR represents transistor, and PC represents that (wherein, A represents the emission side of photoelectrical coupler to photoelectrical coupler, B represents the sensitive side of photoelectrical coupler), MS represents A.C. contactor, and CR represents relay, the Tr indication transformer, SCR represents IGCT, and IPL represents paralleing reactor.
Fig. 3 is the circuit diagram of an object lesson of the failure detector circuit in the holding circuit shown in Figure 2.As shown in Figure 3, this failure detector circuit comprises two fault detect branch roads,, comprises the first fault detect branch road 31 and the second fault detect branch road 32 that comprises PC18A of PC17A that is.First fault detect is propped up 31 the tunnel and is comprised first resistance R 420, second resistance R 439, the 3rd resistance R 440, first to the 3rd diode D160-D163, capacitor C160 and photoelectrical coupler emission side PC17A.Wherein, C160, PC17A and D162 parallel connection form detection signal and send part, and two ends have points of common connection 1 and 2 respectively; The end of R440 is connected in points of common connection 2, and the utmost point (anode) of the other end and D163 is connected; Another utmost point (negative electrode) of D163 is connected in the points of common connection A2 of IGCT SCR4-6; The utmost point (negative electrode) of D161 is connected in K5, and another utmost point (anode) is connected in points of common connection 1; The end of R439 is connected in points of common connection 1, and the other end is connected in the points of common connection of R420 and D160, and the other end of R420 is connected in K1, and the other end of D160 is connected in K4.As can be seen from Figure 3, K1, K4 lay respectively on secondary two groups different three-phase U, the W ' and V ' of main transformer with K5.By above-mentioned connected mode, the first fault detect branch road 31 can be used for detecting whether short circuit of SCR4, SCR5, also can be used for detecting input simultaneously and whether lacks U mutually or the V phase.The second fault detect branch road 32 comprises R421, R441, R442, D164-D167, C161 and PC18A, its inner annexation is similar to the annexation of the first fault detect branch road, for for purpose of brevity, no longer be described in detail at this, those skilled in the art can realize in conjunction with the description of the first fault detect branch road 31 according to Fig. 3.It is to be noted that 4 terminal R421, D164, D165 and D167 of the second fault detect branch road 32 are connected to the points of common connection A1 of K4, K2, K1 and SCR1-3, can be used for detecting whether short circuit of SCR1, SCR2, also can be used for detecting input simultaneously and whether lack U mutually or the W phase.Any one short circuit or input lack arbitrary phase time and all have at least one the photoelectrical coupler can't conducting in SCR1, SCR2, SCR4 and SCR5 like this, and the detected state decision circuitry that can be the back provides signal.
It is to be noted, the connected mode of 4 terminals of the above-mentioned first fault detect branch road and the second fault detect branch road is not limited to the example shown in Fig. 3, satisfying under the prerequisite of particular requirement and can adjust, this particular requirement is: the secondary of main transformer is double reverse-stars type, be that U, V, W are star connection mutually, U ', V ', W ' also are star connection, and mutually corresponding anti-phase with U, V, W.
U, V, W three-phase are called A group, U ', V ', W ' three-phase are called the B group, the points of common connection of three IGCTs that the points of common connection of three IGCTs that will link to each other respectively with U, V, W three-phase is called A group IGCT points of common connection, will link to each other respectively with U ', V ', W ' three-phase is called B and organizes the IGCT points of common connection.Like this, the fault detect branch road is when wiring, the arbitrary back mutually (being the U phase among the figure) that has for example connected the A group with the continuous branch road of resistance R 420 (referring to Fig. 3), two branch roads that link to each other with diode D160, D161 will be received respectively on the different other two-phase of B group (being W ', V ' phase among Fig. 3), and the opposite side of above-mentioned resistance and diode sends part, resistance and diode (being D163 among the figure) through the detection signal that comprises photoelectrical coupler and is connected to B group IGCT points of common connection; And when V that resistance R 420 branch roads are received A group mutually after, two branch roads that link to each other with diode D160, D161 will be received U ', the W ' two-phase of B group respectively, the opposite side of fault detect branch road (being D163 among the figure) need be connected to B and organize the IGCT points of common connection; When V ' that resistance R 420 branch roads are received B group mutually after, two branch roads that link to each other with diode D160, D161 will be received U, the W two-phase of A group respectively, the opposite side of fault detect branch road (being D163 among Fig. 3) then need be connected to A group IGCT points of common connection, according to above principle multiple combination can be arranged, not repeat them here.
After the connected mode of the first fault detect branch road was determined, the connected mode of the second fault detect branch road also can correspondingly be determined.For example, if the terminal D163 of the first fault detect branch road is connected to the IGCT points of common connection of B group, then can make the terminal D167 of the second fault detect branch road be connected to the IGCT points of common connection that A organizes, and the terminal R421 that makes the second fault detect branch road is connected in going up mutually that the terminal R420 that is different from the first fault detect branch road of B group connected, and the terminal D164 of the second fault detect branch road and D165 are connected on the other two-phase that is different from the phase that R421 is connected of A group.
In addition, failure detector circuit also can use other devices such as relay to realize above-mentioned detection and detection signal sending function except using photoelectrical coupler.
Certainly, above-mentioned failure detector circuit also can include only a fault detect branch road, and whether the two-phase that is used for detecting the three-phase input phase shortage, and the whether short circuit of two IGCTs.
Fig. 4 is the structure chart of another embodiment of the holding circuit of welding machine of the present invention.As shown in Figure 4, this holding circuit comprises failure detector circuit 41, detected state decision circuitry 42 and protection execution control circuit 43.Wherein, failure detector circuit 41 comprises the first fault detect branch road, the second fault detect branch road, the 3rd fault detect branch road and the 4th fault detect branch road; Detected state decision circuitry 42 comprises that detection signal receiving processing circuit and signal are mutually and circuit; Protection is carried out control circuit 43 and is comprised power supply decision circuitry, on-off circuit, delay circuit and guard signal output circuit.Wherein, first, second fault detect branch road is similar to first, second fault detect branch road among Fig. 3 in the failure detector circuit 41, its the 3rd fault detect branch road and the 4th fault detect branch road are connected across the two ends of IGCT to be detected, are used to judge whether short circuit of IGCT to be measured.The emission side of failure detector circuit 41 detected signals by photoelectrical coupler sends to the detection signal receiving processing circuit in the detected state decision circuitry 42; after the detection signal receiving processing circuit is simply handled signal, carry out control circuit by outputing to protection behind signal and the circuit.Charged and guard signal output circuit moves under back two kinds of situations at the main transformer of welding machine; power supply can carry out remainder power supply in the control circuit 43 for detected state decision circuitry 42 and protection by the power supply decision circuitry; the control signal of on-off circuit is the output from detected state decision circuitry 42; if it is normal to detect the welding machine duty; switch ends; if detected abnormal conditions then switch conduction; electric capacity charging in delay circuit; guard signal output circuit action after a period of time; the output protection signal; by affacting A.C. contactor is disconnected; make the main transformer outage, reach the purpose of protection.Though main transformer is not charged after this; but according to because of the top reason that has illustrated; power supply still can carry out control circuit 43 power supplies for detected state decision circuitry 42 and protection by the power supply decision circuitry; guard signal can be exported always; realize the self-locking of protection like this, can remove this self-locking after restarting welding machine.Physical circuit figure below in conjunction with Fig. 5 and Fig. 6 illustrates this embodiment.
Fig. 5 is a concrete circuit diagram of using of the failure detector circuit of holding circuit shown in Figure 4.Compare with Fig. 3, except comprising the first fault detect branch road 31 and the second fault detect branch road 32, also comprise the 3rd fault detect branch road 53 and the 4th fault detect branch road 54 in the failure detector circuit of Fig. 5.The 3rd fault detect branch road 53 comprises R422, PC19A, D169, D168, C162.Wherein, C162, PC19A and D168 parallel connection, two ends have first points of common connection 3 and second points of common connection 4 respectively; One end of resistance R 422 is connected in K6, and the other end links to each other with first points of common connection 3; The end of diode D169 is connected in the points of common connection A2 of SCR4-6, and the other end links to each other with second points of common connection 4.Like this, the 3rd fault detect branch road 53 is connected across the two ends of IGCT SCR6, detects the backward voltage of IGCT SCR 6.Under the normal condition, intermittently conducting of photoelectrical coupler, after IGCT SCR6 short circuit, its backward voltage is always 0 or low excessively, then photoelectrical coupler not conducting all the time.The 4th fault detect branch road 54 comprises R423, PC20A, D170, D171, C163.Wherein, C163, PC20A and D170 parallel connection, two ends have first points of common connection and second points of common connection respectively; One end of resistance R 423 is connected in K3, and the other end links to each other with first points of common connection; The end of diode D171 is connected in the points of common connection A1 of SCR1-3, and the other end links to each other with second points of common connection.Like this, the 4th fault detect branch road 54 is connected across the two ends of IGCT SCR3, detects the backward voltage of IGCT SCR3.Under the normal condition, intermittently conducting of photoelectrical coupler, after IGCT SCR3 short circuit, its backward voltage is always 0 or low excessively, then photoelectrical coupler not conducting all the time.
Identical with the situation among Fig. 2, the connected mode of the first fault detect branch road 31 and the second fault detect branch road 32 is satisfying under the specified conditions and can adjust, and whether imports the whether short circuit of phase shortage and 4 IGCTs mutually in order to detect U, V, W.The 3rd fault detect branch road 53 and the 4th fault detect branch road 54 can be used for detecting the whether short circuit of other two IGCTs.
Fig. 6 is the detected state decision circuitry of holding circuit shown in Figure 4 and the circuit diagram that an object lesson of control circuit is carried out in protection.Wherein, empty frame 61 indications in the left side is the detected state decision circuitry among Fig. 6, and empty frame 62 indications in the right is that control circuit is carried out in protection.
The operation principle of detected state decision circuitry 61 is as follows: photoelectrical coupler exists conducting state to be judged to be normally, with 4 the tunnel make and relation, the 4 tunnel all just often be judged to be normal, have 1 the tunnel undesired then be judged to be undesired.
Detected state decision circuitry 61 comprises detection signal receiving processing circuit and signal and circuit two parts.Wherein, the detection signal receiving processing circuit comprises photoelectrical coupler sensitive side PC17B-PC20B, resistance R 424-R427, capacitor C164-C167 and resistance R 428-R431.When the interrupted conducting of PC17B-PC20B, can charge to C164-C167 by R424-R427 respectively, R428-R431 is a discharge resistance, thus, under the normal condition, the C164-C167 positive pole can be kept high level, but the signal of receiving test circuit and provide signal for the circuit of back thus.The positive pole of C164-C167 is linked the negative electrode of D172-D175 respectively, and the anode of D172-D175 connects together, and can form thus and door, constitutes four road signals phase and circuit.Signal is under normal circumstances exported high level with circuit, under abnormal conditions, promptly when one or several photoelectrical couplers all the time can't conductings, discharge becomes low level or itself just can't charge after among the corresponding C164-C167 one or several a period of times, like this D172-D175 formation with the exportable low level of door.
As can be seen from Figure 6, the detection signal receiving processing circuit is made up of 4 relatively independent detection signals reception processing branch roads, each branch road comprises photoelectrical coupler sensitive side (for example PC17B), first resistance (for example R424), capacitor (for example C164) and second resistance (for example R428), wherein, the capacitor and the second resistance parallel connection, a their points of common connection ground connection, the another one points of common connection links to each other with an end of first resistance, and the other end of first resistance links to each other with the photoelectrical coupler sensitive side.A way of detection signal receiving processing circuit and the way correspondence in the failure detector circuit judge that according to receiving from the signal output state of fault detect branch road signal is to signal phase and circuit.Therefore, in different application, can select to prop up the corresponding detection signal of way as required and receive a processing way with fault detect.Those skilled in the art can realize detected state decision circuitry among Fig. 2 according to the instruction of the detected state decision circuitry among Fig. 6.
Protection is carried out control circuit 62 and is received the signal that detected state decision circuitry 61 provides, and normally then is failure to actuate as signal, then through passing through certain way output protection signal after one section time-delay, controls the interlock circuit action as abnormal signal.Protection is carried out control circuit 62 and is mainly comprised on-off circuit, delay circuit, guard signal output circuit and 4 parts of power supply decision circuitry.Wherein, on-off circuit is made of the ZD25 and the QR14 of series connection, and wherein the negative electrode of ZD25 links to each other with the base stage of QR14, on-off circuit conducting when detected state decision circuitry 61 output low levels, and delay circuit and guard signal output circuit that the back is connected work.Delay circuit is made of R432, R433, C168, ZD26, wherein, R433 and C168 parallel connection, the points of common connection ground connection of C168 negative pole and R433 one end, C168 points of common connection anodal and the R433 other end is connected on the contact between the negative electrode of R432 and ZD26, and the other end of R432 links to each other with the colelctor electrode of QR14.The time-delay of carrying out a period of time by delay circuit after the QR14 conducting is the output protection signal again.Because in use QR14 may be because of malfunction or the other reasons appearance conducting in short-term of welding machine short time; but as long as ON time is no more than the delay time of setting; the holding circuit of back just can the output protection signal; can accomplish when unnecessary not output protection signal like this, not influence the normal use of welding machine.The guard signal output circuit is made of QR15 and D177, and the negative electrode of D177 links to each other with the colelctor electrode of QR15.The base stage of QR15 links to each other with the anode of delay circuit ZD26, QR15 conducting behind the delay circuit output protection signal, and the A.C. contactor by in the D177 output control signal control major loop disconnects A.C. contactor, realizes the purpose of protection.Comprising power supply during decision circuitry, the QR15 conducting can make the QR13 in the power supply decision circuitry keep conducting, realizes self-locking, can remove self-locking after restarting welding machine.
The power supply decision circuitry comprises QR13, PC21, R434-R437, C169, C170, D176, D178, D179.R437 and D176 form and detect whether first decision circuitry of output signal of guard signal output circuit, and wherein, the end of R437 and the anode of D176 are connected, and the negative electrode of D176 is connected with the colelctor electrode of QR15.Whether charged PC21, R434-R436, C169, C170, D178, D179 form and detect main transformer second decision circuitry, and concrete annexation as shown in Figure 6.Two branch roads of second decision circuitry connect No. 81 lines and No. 82 lines of the secondary control coil of main transformer.The base stage of first decision circuitry, second decision circuitry and QR13 is connected to points of common connection 4; The emitter stage of QR13 links to each other with positive source, and emitter stage and the detected state decision circuitry 61 of colelctor electrode and QR14 link to each other.The power supply decision circuitry controls whether carry out other circuit supplies in the control circuit 62 to detected state decision circuitry 61 and protection by transistor QR13 as switch; the circuit supply of can be at main transformer giving other after the charged or QR15 conducting, thus whether control whole protecting circuit works.The control signal of this transistor switch has two, and the one, whether charged by the electric circuit inspection main transformer that devices such as photoelectrical coupler are formed, if charged, then above-mentioned switch conduction, otherwise not conducting; Another is that the guard signal output circuit output protection signal whether in the control circuit is carried out in protection, if output then can make above-mentioned switch conduction.Above-mentioned two control signals be " or " relation, any works and all can make the transistor switch conducting.The power supply decision circuitry just begins other part power supplies in holding circuit after main transformer is charged, to prevent the maloperation of holding circuit.This is because if the above-mentioned control of the decision circuitry of not powering; then when main transformer is not charged; all not conductings of photoelectrical coupler in the failure detector circuit; make the low level of detected state decision circuitry 61 output as the abnormal signal in the holding circuit; cause protection to carry out control circuit output protection signal; make the holding circuit action, causing welding machine to be started shooting just can't operate as normal.Carry out control circuit 62 power supplies also can for after the guard signal output circuit action detected state decision circuitry 61 and protection is self-locking in order to realize protecting.The abnormal conditions execute protection takes place after; A.C. contactor disconnects; main transformer can cut off the power supply; if the power supply decision circuitry only whether power to holding circuit according to main transformer by charged judging whether; then this moment, holding circuit also can together be cut off the power supply; can't continue the output protection signal; like this; at short notice; A.C. contactor is adhesive once more, detects after the fault to disconnect again, and nonserviceabling down repeatedly so, butt welding machine may cause damage; therefore be provided with the auto-lock function that the power supply decision circuitry realizes protection; in case after the protection, under open state, with regard to sustainable output protection signal; A.C. contactor all the time can't adhesive, waits and can remove this self-locking after restarting welding machine.
It is pointed out that and can regard above-mentioned on-off circuit, delay circuit and guard signal output circuit as a switching device, this switching device can increase or reduce the assembly that comprises as required.
Holding circuit provided by the invention not only can detect the short trouble of IGCT but also can detect the input open-phase fault by same circuit, and corresponding protection is provided.Can realize a kind of circuit, two kinds of functions.In addition, the holding circuit simplicity of design just can realize detecting and defencive function with less device.
And also comprise the power supply decision circuitry in the protection execution control circuit, constitute switch by transistor to control whether carry out other circuit supplies in the control circuit, thereby whether control protection electric circuit needs work to detected state decision circuitry and protection.The power supply decision circuitry just begins power supply after main transformer is charged, prevent the holding circuit misoperation; The power supply decision circuitry also can be powered after the action of guard signal output circuit, realizes the self-locking of protection, restarts welding machine and can remove this self-locking, prevents to nonserviceable to protect butt welding machine to cause damage repeatedly down.
Description of the invention provides for example with for the purpose of describing, and is not exhaustively or limit the invention to disclosed form.Many modifications and variations are obvious for the ordinary skill in the art.Selecting and describing embodiment is for better explanation principle of the present invention and practical application, thereby and makes those of ordinary skill in the art can understand the various embodiment that have various modifications that the present invention's design is suitable for special-purpose.

Claims (14)

1. a silicon controlled welding machine is characterized in that, comprises
Main transformer;
A.C. contactor is arranged on the primary side of described main transformer, and being used for provides or disconnect alternating electromotive force described main transformer;
IGCT is arranged on the primary side of described main transformer, is used for control welding output;
Failure detector circuit is arranged between described IGCT anode and the negative electrode, the intermittently conducting when the operate as normal of described welding machine of described failure detector circuit;
The detected state decision circuitry with described failure detector circuit isolation coupling, can be judged the conducting state of described failure detector circuit, when judging that there is not conducting state in described failure detector circuit, and the output abnormality status signal;
Control circuit is carried out in protection; link to each other with described detected state decision circuitry; can control described A.C. contactor, be used for when the abnormality signal that receives from described detected state decision circuitry, controlling described A.C. contactor described main transformer is disconnected alternating electromotive force.
2. welding machine as claimed in claim 1 is characterized in that, described IGCT has 6, is connected with secondary two group three of described main transformer respectively, and described two groups of three-phases are the double reverse-stars type connection;
Described failure detector circuit comprises the first fault detect branch road at least, one end of the described first fault detect branch road comprises 3 nodes, link to each other with the described first mutually different other two-phase in first group first phase, second group respectively with in described two groups, the points of common connection of the IGCT that the other end of the described first fault detect branch road links to each other with described second group of three-phase links to each other;
Wherein, described first group is in described two groups of three-phases any one group, and described first is U, V, the W any phase in mutually mutually.
3. welding machine as claimed in claim 2 is characterized in that, described failure detector circuit also comprises the second fault detect branch road; One end of the described second fault detect branch road comprises 3 nodes, be different from the other two-phase that is different from described second phase in described first mutually second phase, described first group and link to each other respectively with in described second group, the points of common connection of the IGCT that the other end of the described second fault detect branch road links to each other with described first group of three-phase is continuous.
4. as claim 2 or 3 described welding machines, it is characterized in that the described first fault detect branch road comprises that first resistance continuous with described first, first diode and second diode, the 3rd diode that links to each other with described points of common connection and second resistance, the detection signal that link to each other with other two-phase respectively send part, the 3rd resistance; Wherein, described first resistance and first diode are parallel-connected to an end of described second resistance jointly, the other end of described second resistance and second diode are parallel-connected to described detection signal jointly and send part, and described detection signal sends part and described the 3rd resistance, the 3rd diode are connected successively; Described detection signal sends part and comprises electric capacity, photoelectrical coupler and the diode that is connected in parallel.
5. welding machine as claimed in claim 3 is characterized in that, described failure detector circuit also comprises the 3rd, the 4th fault detect branch road;
Wherein, described the 3rd fault detect branch road is connected across the two ends with the second described first group IGCT that is connected; Described the 4th fault detect branch road is connected across the two ends with the first described second group IGCT that is connected, and is used to judge whether short circuit of IGCT to be measured.
6. as claim 2,3 or 5 described welding machines; it is characterized in that; described detected state decision circuitry comprises that detection signal receive to handle branch road and signal mutually and circuit; described detection signal receives handles branch road and the corresponding isolation coupling of described fault detect branch road; judge signal to described signal mutually and circuit according to the signal output state of described fault detect branch road, described signal and circuit are judged after signal carries out handling with door described state and are outputed to described protection execution control circuit.
7. as claim 2,3 or 5 described welding machines, it is characterized in that described protection is carried out control circuit and comprised:
Switching device is used to receive the status signal from described detected state decision circuitry, and when described status signal was the abnormality signal, the output protection signal was to described A.C. contactor;
The power supply decision circuitry links to each other with the secondary control coil of described main transformer and the output of described switching device, is used to described detected state decision circuitry and described switching device that electric power is provided;
Wherein, when described main transformer was not charged, described power supply decision circuitry stopped to provide electric power; When described switching device output protection signal, described power supply decision circuitry provides electric power to described detected state decision circuitry and described switching device.
8. a holding circuit that is used to detect welder fault is characterized in that, comprises
Failure detector circuit is arranged between the anode and negative electrode of IGCT of described welding machine, the intermittently conducting when described welding machine operate as normal of described failure detector circuit;
The detected state decision circuitry with described failure detector circuit isolation coupling, can be judged the conducting state of described failure detector circuit, when judging that there is not conducting state in described failure detector circuit, and the output abnormality status signal; And
Control circuit is carried out in protection; link to each other with described detected state decision circuitry;, can control the A.C. contactor of described welding machine, be used for when the abnormality signal that receives from described detected state decision circuitry, controlling described A.C. contactor the main transformer of described welding machine is disconnected alternating electromotive force.
9. holding circuit as claimed in claim 8 is characterized in that, described IGCT has 6, is connected with secondary two group three of described main transformer respectively, and described two groups of three-phases are the double reverse-stars type connection;
Described failure detector circuit comprises the first fault detect branch road at least, one end of the described first fault detect branch road comprises 3 nodes, link to each other with the described first mutually different other two-phase in first group first phase, second group respectively with in described two groups, the points of common connection of the IGCT that the other end of the described first fault detect branch road links to each other with described second group of three-phase links to each other;
Wherein, described first group is in described two groups of three-phases any one group, and described first is U, V, the W any phase in mutually mutually.
10. holding circuit as claimed in claim 9 is characterized in that, described failure detector circuit also comprises the second fault detect branch road; One end of the described second fault detect branch road comprises 3 nodes, be different from the other two-phase that is different from described second phase in described first mutually second phase, described first group and link to each other respectively with in described second group, the points of common connection of the IGCT that the other end of the described second fault detect branch road links to each other with described first group of three-phase is continuous.
11. as claim 9 or 10 described holding circuits, it is characterized in that the described first fault detect branch road comprises that first resistance continuous with described first, first diode and second diode, the 3rd diode that links to each other with described points of common connection and second resistance, the detection signal that link to each other with other two-phase respectively send part, the 3rd resistance; Wherein, described first resistance and first diode are parallel-connected to an end of described second resistance jointly, the other end of described second resistance and second diode are parallel-connected to described detection signal jointly and send part, and described detection signal sends part and described the 3rd resistance, the 3rd diode are connected successively; Described detection signal sends part and comprises electric capacity, photoelectrical coupler and the diode that is connected in parallel.
12. holding circuit as claimed in claim 10 is characterized in that, described failure detector circuit also comprises the 3rd, the 4th fault detect branch road;
Wherein, described the 3rd fault detect branch road is connected across the two ends with the second described first group IGCT that is connected; Described the 4th fault detect branch road is connected across the two ends with the first described second group IGCT that is connected, and is used to judge whether short circuit of IGCT to be measured.
13. as claim 8,9 or 12 described holding circuits; it is characterized in that; described detected state decision circuitry comprises that detection signal receive to handle branch road and signal mutually and circuit; described detection signal receives handles branch road and the corresponding connection of described fault detect branch road; judge signal to described signal mutually and circuit according to the signal output state of described fault detect branch road, described signal and circuit are judged after signal carries out handling with door described state and are outputed to described protection execution control circuit.
14., it is characterized in that described protection is carried out control circuit and comprised as claim 8,9 or 12 described holding circuits:
Switching device is used to receive the status signal from described detected state decision circuitry, and when described status signal was the abnormality signal, the output protection signal was to described A.C. contactor;
The power supply decision circuitry, the output of carrying out control circuit with the secondary control coil and the described protection of described main transformer links to each other, and is used to described detected state decision circuitry and described switching device that electric power is provided;
Wherein, when described main transformer was not charged, described power supply decision circuitry stopped to provide electric power; When described switching device output protection signal, described power supply decision circuitry provides electric power to described detected state decision circuitry and described switching device.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102909459A (en) * 2012-10-12 2013-02-06 申巧言 Welding system without control line
CN104057181A (en) * 2014-06-23 2014-09-24 上海威特力焊接设备制造股份有限公司 Open-phase protection circuit for inverter welding machine
CN114406409A (en) * 2022-03-30 2022-04-29 中国船级社 Method, device and equipment for determining fault state of welding machine

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1186162C (en) * 2002-06-27 2005-01-26 上海交通大学 Digital driving circuit for main circuit of silicon controlled welding machine
CN1665094A (en) * 2004-03-03 2005-09-07 陈庆荣 Open-phase protector using silicon controlled switch characteristics directly
CN1604447A (en) * 2004-11-04 2005-04-06 上海交通大学 Digital trigger circuit of twelve-phase silicon controlled welding power source
CN201291341Y (en) * 2008-10-17 2009-08-19 唐山松下产业机器有限公司 Controllable silicon welding machine and protective circuit

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102909459A (en) * 2012-10-12 2013-02-06 申巧言 Welding system without control line
CN102909459B (en) * 2012-10-12 2014-12-17 申巧言 Welding system without control line
CN104057181A (en) * 2014-06-23 2014-09-24 上海威特力焊接设备制造股份有限公司 Open-phase protection circuit for inverter welding machine
CN114406409A (en) * 2022-03-30 2022-04-29 中国船级社 Method, device and equipment for determining fault state of welding machine
CN114406409B (en) * 2022-03-30 2022-07-12 中国船级社 Method, device and equipment for determining fault state of welding machine

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