CN104297625A - PT wire breakage diagnosis system and method - Google Patents
PT wire breakage diagnosis system and method Download PDFInfo
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- CN104297625A CN104297625A CN201410623716.7A CN201410623716A CN104297625A CN 104297625 A CN104297625 A CN 104297625A CN 201410623716 A CN201410623716 A CN 201410623716A CN 104297625 A CN104297625 A CN 104297625A
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Abstract
The invention relates to a PT wire breakage diagnosis system and method and belongs to the field of diagnosis of electric appliance parts. The system comprises a controller, a rectifying device and a multifunction table, wherein the multifunction table is connected with a main motor and used for collecting signals of the main motor. The multifunction table outputs parameter signals to the controller, and the controller calculates a current given value required by a motor system and sends the current given value to the rectifying device. The output end of the rectifying device and the controller form a closed loop, and the rectifying device outputs accurate field current required by the main motor. According to the system and the method, the system can be subjected to the PT wire breakage real-time monitoring during the operation of a synchronous machine, the problem that the motor and the equipment are damaged under the condition of PT wire breakage as the synchronous machine is in an asynchronous operation state due to no self-diagnostic program for PT wire breakage is solved.
Description
Technical field
The invention belongs to the application of new technology, relate to the exciter control system of large-scale oxygen synchronous motor and running state analysis thereof and security protection technology field.
Background technology
For oxygen making unit, air compressor machine is the opertaing device of the wherein most important thing, and the air compressor machine of large oxygen-making machine group all adopts synchrodyne to drag.The control of synchrodyne control system is good and bad will directly affect the safety of its production and equipment, particularly the power factor of synchro generator excitation system controls, the no-trump that has of its three-phase voltage directly affects the calculating of relevant parameters in excitation system, particularly power factor, the change of exciting current can be caused, thus make synchrodyne be in underexcitation and desynchronizing state, finally make the running current of synchrodyne excessive and chaser.In fact, send through insurance after three-phase voltage is detected by PT, loose contact is loosened when having insurance disconnection or signal wire terminal, when the actual signal sent is false spurious signal, in order to avoid the generation of similar phenomenon of the failure, run under after PT broken string, Synchro exciter control is switched to constant idle or constant excitation megnet current conditions, synchrodyne is made to be unlikely to cause synchrodyne to run under asynchronous mode when constant power factor closed loop because of the change of other parameter, the most senior general of asynchronous operation electric current is 3 ~ 4 times of normal rating electric current, thus affect the performance and used life etc. of synchrodyne.At present, the excitation of various large synchronous machine all adopts constant power factor to control, and its PT broken string is recurrent, and the disorderly closedown caused thus is also at home and abroad of common occurrence.
Summary of the invention
The invention provides a kind of PT broken string diagnostic system and method, this system and method can carry out PT broken string Real-Time Monitoring to system in synchrodyne runs, overcome in PT broken string situation, because the self-diagnostic program that breaks without PT makes synchrodyne be in asynchronous operation state, thus cause the deficiency of the injury to motor and equipment.
Technical scheme of the present invention is: a kind of PT broken string diagnostic system, this system comprises: connect the multifunctional meter, controller and the fairing that gather mair motor signal, multifunctional meter output parameter signal is to controller, controller calculates given value of current value needed for electric system and is sent to fairing, the output terminal of fairing and controller form closed loop, and fairing exports the accurate exciting current needed for mair motor.Be provided with three analog switches between the signals collecting end of described mair motor and multifunctional meter and carry out the simulation of broken string situation.Described multifunctional meter is completed by Process FieldbusROFIBUS transmission to the Signal transmissions of controller and controller to the Signal transmissions of fairing.Described multifunctional meter mainly gathers voltage, the current signal of mair motor, and calculates the active power of mair motor, reactive power, applied power and power factor parameter.The voltage signal that described multifunctional meter gathers mair motor is three-phase voltage magnitude of voltage.
A kind of PT broken string diagnostic method, the method comprises the steps: that step one, synchrodyne start, and mair motor is in running status; The three-phase voltage of the synchrodyne that step 2, basis detect judges whether PT breaks; If step 3 does not diagnose out PT to break, proceed the diagnosis of PT broken string; If diagnose out PT to break, whether systematic evaluation, to permanent idle control mode, diagnoses PT broken string to recover simultaneously; If step 4 not diagnosis is recovered to PT broken string, then system keeps permanent idle control mode; If diagnose PT broken string to recover, System recover is to constant power factor mode.Described PT broken string diagnostic method implements on the basis that system can debug PT diagnosis, and the detection method that system debug PT diagnoses is: steps A. open the switch be connected between multifunctional meter and synchrodyne respectively, carry out the PT situation that breaks and simulate; Step B. is when PT breaks, and can systems axiol-ogy automatically switch to permanent idle control mode; Step C. synchrodyne runs, and PT breaks debugging; Step D. adds 10 ~ 80% of nominal load and carries out trial production debugging, normally produces after PT burn out detection is normal.
The diagnostic result of described PT broken string is divided into single-phase wire break, two-phase broken string, three-phase broken string, three-phase pressure loss and single-phase earthing.The judgment basis of described PT broken string is: (1) is less than 3KV and motor operating current is greater than 200A when three-phase line voltage summation, when three-phase line voltage is less than 1KV respectively, exports PT three-phase pressure loss; (2) when three alternate line voltage summations are greater than 3KV and are less than or equal to 9KV, motor operating current is greater than 400A, when three-phase line voltage is less than 3KV respectively, exports PT three-phase broken string; (3), when three-phase line voltage summation is greater than 9KV and is less than 15KV, when a line voltage in three-phase is less than 3KV, the two-phase broken string being less than the line voltage of 3KV is exported; (4) when three alternate line voltage summations are more than or equal to 15KV and are less than 25KV, when a line magnitude of voltage in three-phase is greater than 9KV, single-phase wire break mutually adjacent therewith.
In three-phase voltage in described PT broken string, arbitrary phase ground connection judgment basis is: in three-phase, two-phase phase voltage is greater than 9KV simultaneously, when the phase voltage of third phase is less than 3KV, is less than the phase ground connection that the phase voltage of 3KV is corresponding.
The present invention has following good effect: the PT broken string self-diagnosable system provided in the present invention can carry out Real-Time Monitoring under synchrodyne running status, avoid PT to break the injury caused motor and equipment, and in the present invention, also comprise the pre-debugging part of carrying out PT broken string situation, avoid the failure problems of self-diagnosable system and method, first trial production debugging is carried out to synchrodyne, it also avoid the potential problems of equipment, ensure that normal production.Present system maintainability is strengthened, particularly synchrodyne startup success ratio reaches 100%, application on oxygen synchro generator excitation shows as stability, reliability and Ability of Resisting Disturbance and significantly improves, and the transformation for systems such as blast furnace blower synchrodyne, petrochemical complex class large synchronous machines provides valuable experience.
Accompanying drawing explanation
Fig. 1 is the structured flowchart of the PT broken string diagnostic system in the present invention;
Fig. 2 is the process flow diagram of the PT broken string diagnosis in the present invention;
Fig. 3 be the three-phase voltage in the present invention normal time voltage vector polar plot;
Fig. 4 is the polar plot of the A phase voltage broken string in the present invention;
Fig. 5 is the polar plot of the B phase voltage broken string in the present invention;
Fig. 6 is the polar plot of the C phase voltage broken string in the present invention;
Fig. 7 is the polar plot of the AB phase voltage broken string in the present invention;
Fig. 8 is the polar plot of the BC phase voltage broken string in the present invention;
Fig. 9 is the polar plot of the CA phase voltage broken string in the present invention;
Figure 10 is the method schematic diagram that the debugging PT in the present invention diagnoses.
Embodiment
Contrast accompanying drawing below, by the description to embodiment, the specific embodiment of the present invention is as the effect of the mutual alignment between the shape of involved each component, structure, each several part and annexation, each several part and principle of work, manufacturing process and operation using method etc., be described in further detail, have more complete, accurate and deep understanding to help those skilled in the art to inventive concept of the present invention, technical scheme.
A kind of PT broken string diagnostic system, as shown in Figure 1, this system comprises: multifunctional meter, controller and fairing, multifunctional meter gathers the signal of synchrodyne motor, three switch control rule three-phase voltages are provided with between multi-functional and mair motor, the signal that multifunctional meter gathers is sent to controller by Profibus network (Process FieldbusROFIBUS) transmission, controller calculates given value of current value needed for electric system and is sent to fairing by Profibus network again, the output terminal of fairing and controller form closed loop, last fairing exports the accurate exciting current value needed for mair motor, exciting current value is the current value of excitation system in synchrodyne.
Multifunctional meter in system mainly gathers voltage, the current signal of mair motor, and calculates the active power of mair motor, reactive power, applied power and power factor parameter, and wherein multifunctional meter gathers the voltage signal of mair motor is three-phase voltage magnitude of voltage.Multifunctional meter passes data to after in controller, that the controller in the present invention adopts is PLC (programmable logic controller (PLC) Programmable Logic Control ler, be called for short PLC, steering order can be loaded at any time in internal memory and store and perform), the various parameters such as the power factor that multifunctional meter is obtained by Profibus network by controller are read in PLC, through complicated vector calculation, calculate the exciting current set-point in operation needed for motor, fairing is given by the set-point calculated again by Profibus network, fairing is by the accurate exciting current required for closed-loop control output motor.
A kind of PT broken string diagnostic method that the present invention relates to, as shown in Figure 2, method step as shown in Figure 10, comprises the steps: the method process flow diagram
Step one, synchrodyne start, and mair motor is in running status.
The three-phase voltage of the synchrodyne that step 2, basis detect judges whether PT breaks.The diagnostic result of PT broken string is divided into single-phase wire break, two-phase broken string, three-phase broken string, three-phase pressure loss and single-phase earthing.
The judgment basis of PT broken string is made: the normal line magnitude of voltage=10.5KV of system according to the polar plot 3 of three-phase voltage, phase voltage value=6.06KV, the maximal value of voltage gets 1.06 times, minimum value gets 0.9 times, Rated motor electric current=981A, as shown in Figure 3, Ua, Ub and Uc represent the phase voltage of A, B, C three-phase in three-phase voltage, Uab, Ubc and Uca represent the line voltage that A, B, C tri-is alternate, now:
(1), when three-phase line voltage summation is less than 3KV and motor operating current is greater than 200A, when three-phase line voltage is less than 1KV respectively, PT three-phase pressure loss is exported; Namely as Uab+Ubc+Uca<=3kV and Uab<=1kV, Ubc<=1kV, Uca<=1kV motor operating current Im>200A time, report PT three-phase pressure loss.
(2) when three alternate line voltage summations are greater than 3KV and are less than or equal to 9KV, motor operating current is greater than 400A, when three-phase line voltage is less than 3KV respectively, exports PT three-phase broken string; Namely as 3kV<Uab+Ubc+Uca<=9kV and Uab<=3kV, Ubc<=3kV, during Uca<=3kV motor operating current Im>400A, PT three-phase is reported to break.
(3), when three-phase line voltage summation is greater than 9KV and is less than 15KV, when a line voltage in three-phase is less than 3KV, the two-phase broken string being less than the line voltage of 3KV is exported.
Namely, as 9KV<Uab+Uba+Uca<15kV, and when Ubc<3kV, Uab>5kV, Uca>5kV, report BC phase to break, its polar plot as shown in Figure 8;
As 9KV<Uab+Uba+Uca<15kV, and when Uca<3kV, Uab>5kV, Ubc>5kV, report CA phase to break, its polar plot as shown in Figure 9;
As 9KV<Uab+Uba+Uca<15kV, and when Uab<3kV, Ubc>5kV, Uca>5kV, report AB phase to break, its polar plot as shown in Figure 7.
(4) when three alternate line voltage summations be more than or equal to 15KV be less than 25KV time, and when a line magnitude of voltage in three-phase is greater than 9KV, single-phase wire break mutually adjacent therewith.
Both, as 15KV<=Uab+Uba+Uca<25kV, and when Ubc>9kV, Uab>5kV, Uca>5kV, report A phase to break, its polar plot as shown in Figure 4;
As 15KV<=Uab+Uba+Uca<25kV, and when Uca>9kV, Uab>5kV, Ubc>5kV, report B phase to break, its polar plot as shown in Figure 5;
As 15KV<=Uab+Uba+Uca<25kV, and when Uab>9KV, Ubc>5kV, Uca>5kV, report C phase to break, its polar plot as shown in Figure 6.
(5) when in three-phase simultaneously two-phase phase voltage be greater than 9KV, and when the phase voltage of third phase is less than 3KV, be less than the phase ground connection that the phase voltage of 3KV is corresponding.
Namely work as Ua<3kV, and when Ub>9kV, Uc>9kV, report A phase ground connection;
Work as Ua>9kV, and when Ub<3kV, Uc>9kV, report B phase ground connection;
Work as Ua>9kV, and when Ub>9kV, Uc<3kV, report C phase ground connection.
If step 3 does not diagnose out PT to break, proceed the diagnosis of PT broken string; If diagnose out PT to break, whether systematic evaluation, to permanent idle control mode, diagnoses PT broken string to recover simultaneously;
If step 4 not diagnosis is recovered to PT broken string, then system keeps permanent idle control mode; If diagnose PT broken string to recover, System recover is to constant power factor mode.
PT broken string diagnostic method implements on the basis that system can debug PT diagnosis, in order to avoid system PT broken string self diagnosis has fault normally not run, in native system, set up debugging PT diagnostic method, the PT situation that breaks can have been carried out and simulate, PT diagnoses debugging, ensure that the normal production of equipment.As shown in Figure 4, method step comprises the detection method that system debug PT diagnoses:
Steps A. open the switch that is connected between multifunctional meter and synchrodyne respectively, carry out PT and to break situation simulation, three switches disconnect respectively, ensure the authenticity of simulated scenario and comprehensive.
Step B. is when PT breaks, and can systems axiol-ogy automatically switch to permanent idle control mode.According to PT broken string basis for estimation, the operation of scrutiny program, when PT broken string or ground connection, can control system automatically switch to permanent idle control mode.
After the commencement of commercial operation of step C. synchrodyne, PT breaks debugging;
Step D. adds 10 ~ 80% of nominal load and carries out trial production debugging, normally produces after PT burn out detection is normal.PT broken string self diagnosis and the PT situation that breaks is simulated and can be ensured that system performance well, and stability, reliability are all greatly improved, and system starts success ratio can reach 100% with broken string switching rate, the requirement of completely satisfied production and technique.
Above by reference to the accompanying drawings to invention has been exemplary description; obvious specific implementation of the present invention is not subject to the restrictions described above; as long as have employed the improvement of the various unsubstantialities that method of the present invention is conceived and technical scheme is carried out; or design of the present invention and technical scheme directly applied to other occasion, all within protection scope of the present invention without to improve.
Claims (10)
1. a PT broken string diagnostic system, it is characterized in that, this system comprises the multifunctional meter that controller, fairing and connection gather mair motor signal, multifunctional meter output parameter signal is to controller, controller calculates given value of current value needed for electric system and is sent to fairing, the output terminal of fairing and controller form closed loop, and fairing exports the accurate exciting current needed for mair motor.
2. PT broken string diagnostic system according to claim 1, it is characterized in that, described multifunctional meter is connected to the signals collecting end of mair motor signal, is provided with three analog switches carrying out the simulation of broken string situation between mair motor signals collecting end and multifunctional meter.
3. PT according to claim 1 breaks diagnostic system, it is characterized in that, described multifunctional meter is completed by Process FieldbusROFIBUS transmission to the Signal transmissions of controller and controller to the Signal transmissions of fairing.
4. PT according to claim 1 breaks diagnostic system, and it is characterized in that, described multifunctional meter gathers voltage, the current signal of mair motor, and calculates the active power of mair motor, reactive power, applied power and power factor parameter.
5. PT broken string diagnostic system according to claim 4, it is characterized in that, the voltage signal that described multifunctional meter gathers mair motor is the magnitude of voltage of three-phase voltage.
6. a PT broken string diagnostic method, it is characterized in that, the method comprises the steps:
Step one, synchrodyne start, and mair motor is in running status;
The three-phase voltage of the synchrodyne that step 2, basis detect judges whether PT breaks;
If step 3 does not diagnose out PT to break, proceed the diagnosis of PT broken string; If diagnose out PT to break, whether systematic evaluation, to permanent idle control mode, diagnoses PT broken string to recover simultaneously;
If step 4 not diagnosis is recovered to PT broken string, then system keeps permanent idle control mode; If diagnose PT broken string to recover, System recover is to constant power factor mode.
7. PT broken string diagnostic method according to claim 6, is characterized in that, described PT broken string diagnostic method implements on the basis that system can debug PT diagnosis, and the detection method that system debug PT diagnoses is:
Steps A. open the switch be connected between multifunctional meter and synchrodyne respectively, carry out the PT situation that breaks and simulate;
Step B. is when PT breaks, and can systems axiol-ogy automatically switch to permanent idle control mode;
Step C. synchrodyne runs, and PT breaks debugging;
Step D. adds 10 ~ 80% of nominal load and carries out trial production debugging, normally produces after PT burn out detection is normal.
8. PT broken string diagnostic method according to claim 6, is characterized in that, the diagnostic result of described PT broken string is divided into single-phase wire break, two-phase broken string, three-phase broken string, three-phase pressure loss and single-phase earthing.
9. PT broken string diagnostic method according to claim 6, is characterized in that, the judgment basis of described PT broken string is:
(1), when three-phase line voltage summation is less than 3KV and motor operating current is greater than 200A, when three-phase line voltage is less than 1KV respectively, PT three-phase pressure loss is exported;
(2) when three alternate line voltage summations are greater than 3KV and are less than or equal to 9KV, motor operating current is greater than 400A, when three-phase line voltage is less than 3KV respectively, exports PT three-phase broken string;
(3), when three-phase line voltage summation is greater than 9KV and is less than 15KV, when a line voltage in three-phase is less than 3KV, the two-phase broken string being less than the line voltage of 3KV is exported;
(4) when three alternate line voltage summations are more than or equal to 15KV and are less than 25KV, when a line magnitude of voltage in three-phase is greater than 9KV, single-phase wire break mutually adjacent therewith.
10. PT broken string diagnostic method according to claim 6, it is characterized in that, in three-phase voltage in described PT broken string, arbitrary phase ground connection judgment basis is: in three-phase, two-phase phase voltage is greater than 9KV simultaneously, when the phase voltage of third phase is less than 3KV, is less than the phase ground connection that the phase voltage of 3KV is corresponding.
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Cited By (1)
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| CN109541469A (en) * | 2019-01-09 | 2019-03-29 | 中国长江电力股份有限公司 | A kind of generator excited system PT broken string method of discrimination |
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