CN103972866A - Locking method for preventing motor from being switched into short-circuit fault - Google Patents
Locking method for preventing motor from being switched into short-circuit fault Download PDFInfo
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- CN103972866A CN103972866A CN201310040774.2A CN201310040774A CN103972866A CN 103972866 A CN103972866 A CN 103972866A CN 201310040774 A CN201310040774 A CN 201310040774A CN 103972866 A CN103972866 A CN 103972866A
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Abstract
The invention belongs to the field of running control of motors and discloses a locking method for preventing a motor from being switched into a short-circuit fault. The locking method includes that by improving a motor control loop and adopting double locking logic of switch quantity and analog quantity, after a spare power source automatic switch fails to lock, the motor can be effectively prevented from being mistakenly switched into the short-circuit fault; under the circumstance that a spare power source power-losing automatic switch normally acts, the motor can run safely, reliably and continuously to meet requirements of industrial and enterprise production. The locking method is a power supply method which is safe, reliable, easy to implement and used for motor running and has a double locking function, and can be widely used in the field of running control of the motors.
Description
Technical field
The invention belongs to the operation control field of transformer station, relate in particular to a kind of method for motor power supply and startup control.
Background technology
Along with the development of industrial enterprise, reliability requirement to electric power system is more and more higher, in order to improve the reliability of power supply, manufacturing enterprise generally adopts the power supply that two-way can be for subsequent use each other to power, two-way power supply (i.e. the first power supply and second source) respectively with one independently bus section, busbar section be connected, claim traditionally in the industry that this two-way power supply is one section of power supply and two sections of power supplys, and for these two bus section, busbar sections independently, ordinary practice is referred to as one section of bus and two sections of buses (referred to as " one section " and " two sections ", lower same), between two sections of buses, adopt interconnection switch cabinet (referred to as contact cabinet, lower same) connect, the supply power mode of this electric substation is referred to as " bus section operational mode ".
When normal operation, two road power supplys are " apportion " power supply simultaneously, and now the contact cabinet between one section of bus and two sections of buses is in "off" state (i.e. " apportion " running status).
As run into one section or two sections of power failures, and can adopt by contact cabinet " combined floodgate " mode " intermittently " continuation power supply side by side, so just guarantee the uninterrupted electricity consumption on Whole Equipment.
But at some important production units of factory and enterprise, not allow " intermittently " to continue powered operation, for this reason, for the sectionalized single busbar connection operational mode electric substation of Liang Hui supply line, (stand-by power supply drops into power supply " prepared auto restart " automatically, be called for short " prepared auto restart ", lower with) control device is widely applied.When after main electrical breakdown, " prepared auto restart " control system is automatically by in-put of spare power supply operation, the power supply of fast quick-recovery dead electricity bus.Adopt this prepared auto restart supply power mode, the power supply capacity can greatly improve electrical network and normally move time, has guaranteed the continuity of power supply.
And in factory's practical application, facts have proved, fast quick-recovery by above-mentioned technology simple application after the important production unit motor power of factory and enterprise dead electricity, in view of the at present known limitation of its technology of power supply prepared auto restart technical scheme and the uncertain factor of actual production field conditions are difficult to control, inevitably can cause extremely serious work safety accident.Trace it to its cause as described below:
1, because generally adopting, the Motor Control loop of low-voltage power supply system exchanges 380V control power supply, there is " dead electricity " or " low-voltage " fault once system, even if power supply " prepared auto restart " device action drops into stand-by power supply fast, also can cause " dead electricity " in short-term or " voltage falls " of 380V ac control power supply, cause Motor Control contactor low pressure to discharge, " the jumping electricity " of causing some important production unit motor, impact is produced;
2, existing known technology, if notification number day is on February 2nd, 2011, notification number is the Chinese utility model patent of CN201733266U, it discloses a kind of " asynchronous motor send a telegram in reply disposable self-starting device ", this device is made up of the disposable self-start circuit of sending a telegram in reply of the motor on the two-phase circuit being connected in three-phase line, the motor disposable self-start circuit of sending a telegram in reply comprises selector switch SA, the parallel circuits of the coil of the A.C. contactor KM1 being connected with selector switch SA and the auxiliary normally opened contact of A.C. contactor KM1, in triple line, be provided with motor send a telegram in reply disposable self-start circuit A.C. contactor KM1 often open main contacts, disposable self-starting when sending a telegram here again after having a power failure in short-term or for a long time.In other words, this technical scheme is directly linked into the coil of Motor Control contactor between 380V line in AC power, when manual change-over switch SA is got to after automated location, as long as busbar voltage is normal, motor can self-starting running, once after bus " dead electricity " restores electricity by power supply " prepared auto restart ", motor can complete above action equally to carry out " self-starting " and maintains normally and far turn, when change over switch SA gets to while closing, motor shuts down.But the control power supply that the deficiency of this control mode is motor is taken from current supply circuit of motor; once electric power system " low-voltage " event occurs; to cause motor to shut down; in the time of electric power system voltage fluctuation; even cause the frequent starting of motor; not only easily cause device damage, also can affect the continuity of production, bring huge economic loss to factory and enterprise.
For overcoming the above problems, factory and enterprise adopts and controls power supply improved procedure to guarantee in the time there is electric power system low-voltage for some important production unit motor, it is stable that the control power supply of important motor keeps, in power supply " dead electricity ", after " prepared auto restart " regular event switches, can keep the startup continuous operation of motor, but the deficiency that the method exists is, once the locking of power supply prepared auto restart is malfunctioning, when miscarrying switches to power supply " short circuit " fault, will be stable because of Motor Control ring current, contactor can not carry out release with no pressure, cause motor and an electric power system still to link together, even motor body protection effective action, also very easily cause motor insulation scaling loss, even burn, cause electric power system low-voltage, expansion accident, bring larger economic loss to enterprise.
Summary of the invention
Technical problem to be solved by this invention is to provide and a kind ofly prevents that motor switching is in the blocking method of short trouble; it adopts electric power incoming line protection (switching value), inlet wire directional current protection (analog quantity) and the hot relaying protection of motor body etc. to start locking to the startup control loop of motor simultaneously; can avoid motor to be connected to short trouble bus because of the malfunctioning miscarrying of power supply " prepared auto restart " locking; make the continuous supply power mode configuration of electric power system more reliable; perfect; implementation effectively, is conducive to the operation reliably and with long-term of electric substation more indirectly.
Technical scheme of the present invention is: provide a kind of and prevent that motor switching is in the blocking method of short trouble, comprise that Motor Control loop is according to interlocking condition, control motor startup, turn round or stop; The main circuit power of described motor draws a certain section of bus in transformer station, described transformer station adopts double loop incoming power sectionalized single busbar connection operational mode supplying power for outside, described double loop incoming power comprises first, second road incoming power, first, second described road incoming power connects with first, second corresponding bus section, busbar section through first, second service entrance switch respectively, between described first, second bus section, busbar section, be provided with interconnection switch, described interconnection switch is controlled by " prepared auto restart " device; In the time there is " dead electricity " fault in the first or second road incoming power, the described corresponding service entrance switch of " prepared auto restart " device this road incoming power of tripping, interconnection switch between closed first, second bus section, busbar section, by the supplying power for outside of another first, second bus section, busbar section of road incoming power guarantee transformer station; It is characterized in that described blocking method comprises:
A, by the service entrance switch of motor major loop institute connection bus " current quick-breaking " protection actuating signal be serially connected in the startup control loop of motor, former " current quick-breaking " signal application for the protection of bus service entrance switch, in the latch-up protection of motor, is formed to " preventing that miscarrying from connecing locking " function of motor start-up control loop; In the time there is " power supply short circuit fault " in bus, described service entrance switch " current quick-breaking " protection actuating signal is in the moment of bus service entrance switch tripping operation, the synchronous startup control loop that disconnects motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
B, the three-phase inlet wire current of motor major loop institute connection bus is accessed respectively to corresponding current sensing means, the output contact of described current sensing means is serially connected in the startup control loop of motor successively, by former " inlet wire directional current " signal application for bus service entrance switch protection in the latch-up protection of motor, the amplitude situation of change of Real-Time Monitoring inlet wire current, " the large current interlock prepared auto restart of inlet wire " function of formation motor start-up control loop; In the time of bus or bus outgoing generation " power supply short circuit fault " fault, electric current is flowed to bus and is increased rapidly by end of incoming cables; If the amplitude of any phase of inlet wire three-phase current reaches current interlock prepared auto restart when definite value is set, described current sensing means starts immediately, send block signal, disconnect the startup control loop of motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
C, the normally closed contact of motor heating relaying protection actuating signal is concatenated in the startup control loop of motor, as the block signal of motor start-up control loop, forms " motor body fault " blocking function of motor start-up control loop; Once motor generation internal fault, the normally closed contact of hot relaying protection actuating signal is opened, and disconnects the startup control loop of motor, and the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
D, by adopt " prevent miscarrying from connecing locking " function and " the large current interlock prepared auto restart of inlet wire " function in motor start-up control loop simultaneously, prevent that motor miscarrying after power supply prepared auto restart lost efficacy is connected to short trouble bus.
Further, the control power supply of described motor start-up control loop is that UPS uninterruptedly controls power supply, make motor remain adhesive at power supply prepared auto restart switching moment control contactor, thereby after guaranteeing power up, motor obtains electric continuous operation.
Concrete, described in it, " current quick-breaking " of service entrance switch protection actuating signal is normally closed contact, described " current quick-breaking " protection actuating signal is switching value.
The output contact of the current sensing means described in it is normally closed contact, and described " inlet wire directional current " signal is analog quantity.
Further, the current interlock prepared auto restart described in it arranges definite value and presets by following manner:
Ks × I1 ﹥ I
locking﹥ Kk × Ij,
Wherein, I
lockingfor Motor Control loop current locking definite value, I1 is single-line to ground fault electric current, the max calculation load that Ij is system, and Ks-be failure locking coefficient, value is that 0.3, Kk-for starting locking coefficient, value is 2.5.
The max calculation load Ij of the system described in it is starting current and the system running current sum of the maximum motor of system.
Blocking method described in it adopts duplicate protection blocking function is set on motor start-up control loop; in the time that the latch-up protection of power supply prepared auto restart is malfunctioning; can make anticipation in advance to busbar fault; can effectively avoid motor miscarrying to be connected to power supply short circuit fault; cause motor insulation scaling loss or burn, the important production unit motor of guarantee that can be safe and reliable starts running after power supply dead electricity is recovered.
Compared with the prior art, advantage of the present invention is:
1. for preventing that power supply prepared auto restart blocking function lost efficacy, cause power supply prepared auto restart switching in power supply short circuit fault, set up motor error starting latching logic arbitration functions while preventing power supply prepared auto restart switching in power failure in Motor Control loop, can effectively prevent that motor miscarrying is connected to power supply short circuit fault and causes the accident and expand or motor burnout failure occurs;
2. be that stable UPS controls power supply by Motor Control power supply reconfiguration, make motor remain adhesive at power supply prepared auto restart switching moment contactor, thereby after guaranteeing power up, motor obtain electric continuous operation; For preventing the block signal of motor circuit internal fault using motor heating relaying protection as Motor Control loop, guarantee electric power system security of operation;
For some important production units of factory and enterprise after power supply dead electricity, motor can keep running, thereby do not affect production; Can not cause motor to be connected to short trouble because of the malfunctioning miscarrying of power supply prepared auto restart locking, prevent that motor from burning the further expansion that causes the accident, affect the production of enterprise, make the continuous supply power mode configuration of electric power system more reliable, perfect, implementation effectively, is conducive to the operation reliably and with long-term of electric substation more indirectly.
Brief description of the drawings
Fig. 1 is existing band prepared auto restart function power transformation motor major loop wiring schematic diagram in one's power;
Fig. 2 is existing motor latch-up protection current sample schematic diagram;
Fig. 3 is the startup control loop elementary diagram of existing motor;
Fig. 4 is motor start-up control loop elementary diagram of the present invention;
Fig. 5 is motor start-up control logic schematic diagram of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention will be further described.
In Fig. 1, the main circuit power of motor draws a certain section of bus in transformer station, described transformer station adopts double loop incoming power sectionalized single busbar connection operational mode supplying power for outside, described double loop incoming power comprises first, second road incoming power, first, second described road incoming power connects with first, second corresponding bus section, busbar section through first, second service entrance switch respectively, between described first, second bus section, busbar section, be provided with interconnection switch, described interconnection switch is controlled by " prepared auto restart " device; In the time there is " dead electricity " fault in the first or second road incoming power, the described corresponding service entrance switch of " prepared auto restart " device this road incoming power of tripping, interconnection switch between closed first, second bus section, busbar section, ensure the supplying power for outside of first, second bus section, busbar section of transformer station by another road incoming power, and then ensure normal power supply and the operation of two motors (representing with electro-motor 1, electro-motor 2 in figure) shown in figure.
In other words, the present invention be directed to the electric substation of factory and enterprise low-voltage power supply system sectionalized single busbar connection operational mode, this type of electric substation is in the apportion power supply simultaneously of normal operation Shi Er road power supply, as run into one section or two sections of power failures, the power supply that interconnection switch combined floodgate is recovered rapidly to dead electricity bus automatically side by side by power supply prepared auto restart function, but the switching that only relies on power supply prepared auto restart cannot be guaranteed the important motor load continuous operation of factory and enterprise, it is former because one, once bus is because of fault dead electricity, even if power supply prepared auto restart moves rapidly, also will there is of short duration voltage to fall, for the motor load of manufacturing enterprise, its contactor will discharge automatically because of low-voltage, even after power up, motor also will be shut down impact production because contactor discharges, reason two is for some important production units of factory and enterprise, in the time that the modes such as self-starting transformation are carried out in Motor Control loop, once the malfunctioning throwing of power supply prepared auto restart locking switches on power supply short circuit fault, can cause important production unit motor to burn, fault spread, great economic loss will be brought to enterprise.
Visible, for the low pressure electric substation that has power supply prepared auto restart function for sectionalized single busbar connection operational mode, it exists after power supply " dead electricity " recovers, and cannot guarantee the technological deficiency of the safe and reliable running of important production unit motor.
In Fig. 2; former " inlet wire directional current " signal for the protection of bus service entrance switch; obtain by inlet wire current sampling unit; first via electric power incoming line current transformer 1CT and the second road electric power incoming line current transformer 2CT are for detection of the three-phase current of two-way electric power incoming line; detect respectively the three-phase current of two-way electric power incoming line by six current relay 1DJ～6DJ; in the time that any phase current exceedes the default definite value of current relay; this current relay action, output " overcurrent " block signal.
In Fig. 3, the startup control loop of existing motor mainly comprises the self-insurance normal opened contact KM1 of start button SB1, stop button SB2, major loop contactor KM and KM thereof in figure.
Because above-mentioned three accompanying drawings are prior art, its method for drafting and components and parts digital code are all by GB mark, therefore its specific works principle and course of action are no longer narrated at this.
In Fig. 4, blocking method of the present invention comprises:
A, by the service entrance switch of motor major loop institute connection bus " current quick-breaking " protection actuating signal be serially connected in the startup control loop of motor, former " current quick-breaking " signal application for the protection of bus service entrance switch, in the latch-up protection of motor, is formed to " preventing that miscarrying from connecing locking " function of motor start-up control loop; In the time there is " power supply short circuit fault " in bus, described service entrance switch " current quick-breaking " protection actuating signal is in the moment of bus service entrance switch tripping operation, the synchronous startup control loop that disconnects motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
B, the three-phase inlet wire current of motor major loop institute connection bus is accessed respectively to corresponding current sensing means, the output contact of described current sensing means is serially connected in the startup control loop of motor successively, by former " inlet wire directional current " signal application for bus service entrance switch protection in the latch-up protection of motor, the amplitude situation of change of Real-Time Monitoring inlet wire current, " the large current interlock prepared auto restart of inlet wire " function of formation motor start-up control loop; In the time of bus or bus outgoing generation " power supply short circuit fault " fault, electric current is flowed to bus and is increased rapidly by end of incoming cables; If the amplitude of any phase of inlet wire three-phase current reaches current interlock prepared auto restart when definite value is set, described current sensing means starts immediately, send block signal, disconnect the startup control loop of motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
C, the normally closed contact of motor heating relaying protection actuating signal is concatenated in the startup control loop of motor, as the block signal of motor start-up control loop, forms " motor body fault " blocking function of motor start-up control loop; Once motor generation internal fault, the normally closed contact of hot relaying protection actuating signal is opened, and disconnects the startup control loop of motor, and the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
D, by adopt " prevent miscarrying from connecing locking " function and " the large current interlock prepared auto restart of inlet wire " function in motor start-up control loop simultaneously, prevent that motor miscarrying after power supply prepared auto restart lost efficacy is connected to short trouble bus.
Further, the control power supply of described motor start-up control loop is that UPS uninterruptedly controls power supply, make motor remain adhesive at power supply prepared auto restart switching moment control contactor, thereby after guaranteeing power up, motor obtains electric continuous operation.
In conjunction with Ben Tu, the present invention has carried out technological improvement to the control loop of enterprise-essential production unit motor, and its main inventive point is as follows:
1, for guaranteeing after power supply dead electricity, power supply prepared auto restart switches moment Motor Control loop contactor because low-voltage cannot reliably keep the deficiency of adhesive, be ups power power supply by the control power supply reconfiguration of factory and enterprise one-level motor load, guarantee like this to switch moment at power supply prepared auto restart, important production unit motor load can not produced because of the low chaser impact of voltage, after power supply dead electricity is recovered, important production unit motor can ensure to be kept in continuous operation simultaneously;
2, key of the present invention is in the time that the latch-up protection of power supply prepared auto restart is malfunctioning; after Motor Control power supply reconfiguration is ups power power supply; by the improvement to Motor Control loop, can effectively avoid motor miscarrying to be connected to power supply short circuit fault, cause motor burnout failure.Its principle is:
(1) electric power incoming line switch (in figure taking first via electric power incoming line switch 1DL as example) current quick actuating signal normally closed contact (switching value) is connected in series into Motor Control loop, its object is in the time that dead electricity bus is bus generation power supply short circuit fault, electric power incoming line switch 1DL current quick moves rapidly tripping service entrance switch 1DL, if the malfunctioning interconnection switch 3DL(that can occur of now power supply prepared auto restart locking is referring to shown in Fig. 1) order of closing a floodgate, stand-by power supply is thrown and is connected to short trouble, if motor primary connection is still connected in electric power system, to cause important motor apparatus to burn, fault spread, but because electric power incoming line switch 1DL current quick actuating signal normally closed contact (switching value) is connected in series into Motor Control loop, so in the time that busbar fault occurs, the moment of 1DL switch trip will synchronously disconnect Motor Control loop, motor contactor discharges and disconnects motor primary circuit, avoid occurring motor insulation scaling loss or burn, fault spread,
(2) in electric power system actual motion, for guaranteeing in the time that the locking of power supply prepared auto restart is malfunctioning, the reliable disconnection in Motor Control loop avoids fault spread to occur, for the further safe operation of lifting motor, the technical program is analyzed electric power system operation characteristic, propose to adopt the method that detects in real time inlet wire three-phase current amplitude to carry out the locking of Motor Control loop start, by inlet wire three-phase current access current sensing means, moment is followed the tracks of the amplitude situation of change of inlet wire current, in the time of bus or bus outgoing fault, electric current is flowed to bus and is increased rapidly (direction overcurrent protection) by inlet wire, in the time reaching current interlock prepared auto restart definite value be set (for the general distribution network being incorporated into the power networks without generating set, after inlet wire dead electricity, only there is the inertia electric current being produced by the reverse busbar charging of motor on bus, it is worth much smaller than all motor rated current of bus sum, so as long as ensure that current interlock set point is greater than max calculation load current under bus normal operating mode and can ensures that thereby the definite fault of inlet wire dead electricity after-current protection action message is busbar short-circuit fault), current sensing means starts immediately, send its normally closed contact of block signal and open disconnection Motor Control loop, motor primary circuit is broken from electric power system, avoid motor to burn, expansion causes the accident, it is a kind of safe and reliable prepared auto restart closedown mode,
(3) for preventing that motor circuit internal fault is concatenated into motor heating relaying protection actuating signal normally closed contact in motor start-up loop; as the block signal in Motor Control loop; once motor generation internal fault; hot relaying protection actuating signal normally closed contact is opened; disconnect Motor Control electric power loop; motor chaser, avoids equipment burnout, guarantees electric power system security of operation.
Capital equipment model and technical parameter setting:
Unit type:
Thermal overload relay model: TK-N12V-C(rated current 300-450A);
Current relay: 1DJ～6DJ, model: DJ-122/320;
A.C. contactor model: CJ20J-400; Circuit breaker: ABB SACE S5PR211In=400A
Technical parameter arranges:
Adopt the large current interlock prepared auto restart of inlet wire function, set Motor Control loop current locking definite value I
lockingmain electric current index comprises, three-phase shortcircuit electric current I 3, line to line fault electric current I 2, the max calculation load Ij(of single-line to ground fault electric current I 1 and system is starting current and the system running current sum of the maximum motor of system), for the descending I3 ﹥ I2 ﹥ I1 ﹥ Ij that is respectively of TN system power mesh current, because in the present invention, the set point of current interlock is when reliably single-phase the and above fault of locking is avoided motor start-up again, there is frequent locking in motor, so current interlock starting is set as follows:
Ks*I1 ﹥ I
locking﹥ Kk*Ij,
Wherein, major parameter value is, Ks-and be failure locking coefficient, value is 0.3,
Kk-for starting locking coefficient, value is 2.5.
In Fig. 5, provide control principle action logic of the present invention:
1, be that stable UPS controls power supply by Motor Control power supply reconfiguration, make motor remain adhesive at power supply prepared auto restart switching moment control contactor, thereby after guaranteeing power up, motor obtain electric continuous operation;
2, in motor start-up control loop, set up and prevent that miscarrying from connecing blocking function, be that the locking of power supply prepared auto restart is malfunctioning, cause power supply prepared auto restart switching in the time of power supply short circuit fault, disconnect motor start-up control loop by the normally closed contact of service entrance switch 1DL or 2DL current quick trip signal; If adopt by inlet wire current amplitude detection method and judge loop, motor place busbar fault simultaneously, disconnect Motor Control loop by current protection signal normally closed contact, further prevent that motor miscarrying after power supply prepared auto restart lost efficacy is connected to short trouble;
3, hot motor body relaying protection actuating signal is connected in series into Motor Control loop, if there is motor body fault, automatic tripping motor, prevents motor burnout failure.
The present invention is by improving Motor Control loop, adopt the dual latching logic of switching value and analog quantity, effectively prevent that motor miscarrying is connected to short trouble, guarantee in the outside dead electricity prepared auto restart of power supply regular event situation, motor can safe and reliablely turn round, meeting the requirement that industrial enterprise produces, is a kind of method of supplying power to of the motor operation with dual blocking function safe, reliable, easy to implement.
Specific implementation process is as follows:
1. installation instructions:
The current relay that relates to 1# incoming line cabinet, 2# incoming line cabinet in construction installs and fast tripping protection signal contact is drawn etc., requires in strict accordance with high-tension electricity construction regulations, requires cabinet reliably to have a power failure, to guarantee construction safety.
1) interconnection switch cabinet moves side by side, by this inspecting state of 1# electric power incoming line cabinet/2# incoming power cabinet;
2) respectively the switch fast tripping protection signal contact 1DL/2DL of 1# electric power incoming line cabinet/2# incoming power cabinet is led to corresponding protection motor control cabinet;
3) at 1# electric power incoming line, current relay 1DJ, 3DJ, 5DJ are installed cashier's office in a shop respectively, at 2# incoming power cabinet, current relay 2DJ, 4DJ, 6DJ are installed, and according to drawing, its inlet wire contact is connected in series in the current coil of current transformer 1CT, 2CT respectively, current relay 1DJ～6DJ action connection point signal is drawn and delivers to corresponding motor protection cabinet dish;
4) according to drawing by current relay 1DJ～6DJ action connection point, switch fast tripping protection contact 1DL, motor heating relay protection contact point is connected in series respectively into motor start-up control loop;
5) in construction, require lead wire terminal to be reliably fastenedly connected, wiring must be drawn and connect from terminal board, standard construction;
6) set successively the setting current protection definite value of current transformer 1DJ～6DJ according to equipment and technology parameter, for low pressure 380V electric power system, as system single-phase-to-ground current I1=15000A, system max calculation load Ij=1500A, has 0.3*15000A ﹥ I
locking﹥ 2.5*1250A, i.e. 4500A ﹥ I
locking﹥ 3750A, gets I
locking=4000A.
2. function check explanation:
After completing according to construction drawing, to check controlling function, concrete checking procedure is as follows:
1) shorting switch current quick output contact 1DL, the action of simulation service entrance switch fast tripping protection, motor dead electricity starts closed, motor fanout operation;
2) add operating current in current relay 1DJ～6DJ phase-splitting, cause corresponding protection contact output, the latch-up protection of simulation inlet wire current, motor dead electricity starts closed, motor fanout operation;
3) short circuit thermal relay FR protection action outlet, motor dead electricity starts closed, motor fanout operation;
In sum, the present invention is by improving Motor Control loop, adopt the dual latching logic of switching value and analog quantity, after the locking of power supply prepared auto restart is malfunctioning, can effectively prevent that motor miscarrying is connected to short trouble, simultaneously in the outside dead electricity prepared auto restart of power supply regular event situation, the continuous operation that motor can be safe and reliable, meeting the requirement that industrial enterprise produces, is a kind of method of supplying power to of the motor operation with dual blocking function safe, reliable, easy to implement.
By the enforcement of above technology, the present invention can guarantee in the outside dead electricity prepared auto restart of power supply regular event situation, important production unit motor can be safe and reliable running, meet the requirement that enterprise produces, simultaneously in the malfunctioning generation misoperation of the inner dead electricity prepared auto restart locking of power supply situation, motor is by adopting the dual latching logic of switching value and analog quantity, effectively prevent that motor miscarrying is connected to short trouble, avoiding fault spread, is a kind of safe power supply method of the motor operation with dual blocking function safe, reliable, easy to implement.
The present invention can be widely used in the operation control field of transformer station.
Claims (7)
1. prevent that motor switching is in a blocking method for short trouble, comprise that Motor Control loop is according to interlocking condition, control motor startup, turn round or stop; The main circuit power of described motor draws a certain section of bus in transformer station, described transformer station adopts double loop incoming power sectionalized single busbar connection operational mode supplying power for outside, described double loop incoming power comprises first, second road incoming power, first, second described road incoming power connects with first, second corresponding bus section, busbar section through first, second service entrance switch respectively, between described first, second bus section, busbar section, be provided with interconnection switch, described interconnection switch is controlled by " prepared auto restart " device; In the time there is " dead electricity " fault in the first or second road incoming power, the described corresponding service entrance switch of " prepared auto restart " device this road incoming power of tripping, interconnection switch between closed first, second bus section, busbar section, by the supplying power for outside of another first, second bus section, busbar section of road incoming power guarantee transformer station; It is characterized in that described blocking method comprises:
A, by the service entrance switch of motor major loop institute connection bus " current quick-breaking " protection actuating signal be serially connected in the startup control loop of motor, former " current quick-breaking " signal application for the protection of bus service entrance switch, in the latch-up protection of motor, is formed to " preventing that miscarrying from connecing locking " function of motor start-up control loop; In the time there is " power supply short circuit fault " in bus, described service entrance switch " current quick-breaking " protection actuating signal is in the moment of bus service entrance switch tripping operation, the synchronous startup control loop that disconnects motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
B, the three-phase inlet wire current of motor major loop institute connection bus is accessed respectively to corresponding current sensing means, the output contact of described current sensing means is serially connected in the startup control loop of motor successively, by former " inlet wire directional current " signal application for bus service entrance switch protection in the latch-up protection of motor, the amplitude situation of change of Real-Time Monitoring inlet wire current, " the large current interlock prepared auto restart of inlet wire " function of formation motor start-up control loop; In the time of bus or bus outgoing generation " power supply short circuit fault " fault, electric current is flowed to bus and is increased rapidly by end of incoming cables; If the amplitude of any phase of inlet wire three-phase current reaches current interlock prepared auto restart when definite value is set, described current sensing means starts immediately, send block signal, disconnect the startup control loop of motor, the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
C, the normally closed contact of motor heating relaying protection actuating signal is concatenated in the startup control loop of motor, as the block signal of motor start-up control loop, forms " motor body fault " blocking function of motor start-up control loop; Once motor generation internal fault, the normally closed contact of hot relaying protection actuating signal is opened, and disconnects the startup control loop of motor, and the major loop contactor of motor discharges, and major loop of motor is broken from electric power system;
D, by adopt " prevent miscarrying from connecing locking " function and " the large current interlock prepared auto restart of inlet wire " function in motor start-up control loop simultaneously, prevent that motor miscarrying after power supply prepared auto restart lost efficacy is connected to short trouble bus.
2. prevent that according to claimed in claim 1 motor switching is in the blocking method of short trouble, the control power supply that it is characterized in that described motor start-up control loop is that UPS uninterruptedly controls power supply, make motor remain adhesive at power supply prepared auto restart switching moment control contactor, thereby after guaranteeing power up, motor obtain electric continuous operation.
3. prevent that according to claimed in claim 1 motor switching is in the blocking method of short trouble, it is characterized in that " current quick-breaking " protection actuating signal of described service entrance switch is normally closed contact, described " current quick-breaking " protection actuating signal is switching value.
4. prevent that according to claimed in claim 1 motor switching is in the blocking method of short trouble, it is characterized in that the output contact of described current sensing means is normally closed contact, described " inlet wire directional current " signal is analog quantity.
5. prevent that according to claimed in claim 1 motor switching is in the blocking method of short trouble, it is characterized in that described current interlock prepared auto restart arranges definite value and presets by following manner:
Ks × I1 ﹥ I
locking﹥ Kk × Ij,
Wherein, I
lockingfor Motor Control loop current locking definite value, I1 is single-line to ground fault electric current, the max calculation load that Ij is system, and Ks-be failure locking coefficient, value is that 0.3, Kk-for starting locking coefficient, value is 2.5.
6. prevent that according to claimed in claim 5 motor switching is in the blocking method of short trouble, it is characterized in that the max calculation load Ij of described system is starting current and the system running current sum of the maximum motor of system.
7. prevent that according to claimed in claim 1 motor switching is in the blocking method of short trouble; it is characterized in that described blocking method adopts duplicate protection blocking function is set on motor start-up control loop; in the time that the latch-up protection of power supply prepared auto restart is malfunctioning; can make anticipation in advance to busbar fault; can effectively avoid motor miscarrying to be connected to power supply short circuit fault; cause motor insulation scaling loss or burn, the important production unit motor of guarantee that can be safe and reliable starts running after power supply dead electricity is recovered.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310040774.2A CN103972866A (en) | 2013-01-31 | 2013-01-31 | Locking method for preventing motor from being switched into short-circuit fault |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310040774.2A CN103972866A (en) | 2013-01-31 | 2013-01-31 | Locking method for preventing motor from being switched into short-circuit fault |
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| Publication Number | Publication Date |
|---|---|
| CN103972866A true CN103972866A (en) | 2014-08-06 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104811060A (en) * | 2015-04-30 | 2015-07-29 | 中国移动通信集团安徽有限公司阜阳分公司 | Power supply mode distribution system of switch power supply generator set |
-
2013
- 2013-01-31 CN CN201310040774.2A patent/CN103972866A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104811060A (en) * | 2015-04-30 | 2015-07-29 | 中国移动通信集团安徽有限公司阜阳分公司 | Power supply mode distribution system of switch power supply generator set |
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Application publication date: 20140806 |