A kind of method for diagnosing faults of dry reactor higher-order of oscillation impulse voltage withstand test
Art
The invention belongs to high voltage and insulation technology field, be specifically related to the method for diagnosing faults in a kind of dry reactor higher-order of oscillation impulse voltage withstand test.
Background technology
Reactor is equipment important in electrical network, and it has the purposes such as reactive-load compensation, filtering, has many, the widely used features of quantity in electrical network.The insulating forms of reactor has two kinds, and one is oil immersed type, and the main insulating oil that adopts is as insulating medium; One is dry type, adopts the insulation of epoxy casting dipping composition.Dry reactor has the advantage that structure is simple, lightweight and cost is low, and the application in electrical network is more and more extensive.Dry reactor can be subjected to the effect of line voltage, surge voltage and environmental stress and ageing and inferior gradually in operational process, can break down in operational process.Carrying out off-line testing to dry reactor is the key ensureing its safe operation, and because the inductance value of dry reactor own is large, conventional industrial frequency experiment cannot carry out, and therefore studying suitable reactor test method is current focus.
Adopt higher-order of oscillation impulse voltage endurance test method to carry out on-the-spot impulse voltage withstand test to dry reactor, have the advantages that voltage generation efficiency is high, be easy to on-the-spot harmonic.Carrying out carrying out effective fault diagnosis in this process of the test, judging whether test product exists breakdown fault is the key of carrying out test result analysis.
But, owing to involving many circuit components in dry reactor high-frequency percussion withstand voltage test loop, whether these circuit components exist fault and have significant impact to test findings, the erroneous judgement that reactor is tested can be caused, how to avoid this erroneous judgement, high-frequency percussion withstand voltage test is accurately and effectively carried out to dry reactor and becomes a difficult problem crucial at present.
Summary of the invention
In order to solve an above-mentioned difficult problem, avoid the erroneous judgement because test loop components and parts fault causes, the present invention can diagnose for the different faults in dry reactor higher-order of oscillation impulse voltage withstand test, proposes a kind of method for diagnosing faults based on transfer function analysis.
In this method for diagnosing faults, the circuit loop of its dry reactor higher-order of oscillation impulse voltage withstand test diagnosed mainly comprises standard impulse voltage generator 1, first voltage divider 2, first shunt 3, vibration inductance 4, load capacity 5, tested dry reactor 6, second shunt 7 and the second voltage divider 8.
Wherein, load capacity 5 is in parallel with tested dry reactor 6 place circuit branch, and the branch road formed in parallel is connected in series formation loop with vibration inductance 4, standard impulse voltage generator 1; , in this test loop, the voltage and current of specific location is measured: the first voltage divider 2 is in parallel with standard impulse voltage generator meanwhile, therefrom obtain voltage signal U1; Second voltage divider 8 is in parallel with tested dry reactor 6, thus obtains voltage signal U2; First shunt 3 is connected with vibration inductance 4, obtains current signal I1; After second shunt 7 is connected with tested dry reactor 6, obtain current signal I2.
This method for diagnosing faults is namely by first after-applied different trial voltage, record the U1 under different tests voltage, I1, U2, I2, ask for U1 under different tests voltage respectively, the transport function that I1 is relevant, and the transport function that U2, I2 are relevant, the diagnosis of different faults is finally carried out according to the situation of change of two groups of transport functions under different tests voltage.
Further, this dry reactor higher-order of oscillation impulse voltage withstand test troubleshooting step is:
S10. the first trial voltage is applied to tested dry reactor, obtain U1, I1, U2, I2;
S20. according to U1 and I1 calculation of transfer function H1, according to U2 and I2 calculation of transfer function H2;
Wherein, the specific formula for calculation of transport function is
voltage signal is transformed into frequency domain by fast fourier transform to obtain frequency domain distribution by fft (U), current signal is transformed into frequency domain by fast fourier transform and obtains frequency domain distribution by fft (I), and then, at frequency domain, voltage signal and current signal are carried out than acquisition transfer function H;
S30. the second trial voltage is applied to tested dry reactor, obtains U1 ', I1 ', U2 ', I2 ';
S40. according to U1 ' and I1 ' calculation of transfer function H1 ', according to U2 ' and I2 ' calculation of transfer function H2 ';
S50. H1 is compared, H2 and H1 ', H2 ', the situation of change according to its maximal value carries out fault diagnosis.
Further, described step S50 specifically comprises:
The maximal value rate of change that S51. if H1 ' compares H1 and H2 with the maximal value of H2 ' all do not exceed ± and 5%, then judge this test product and vibration inductance, the equal non-fault of load capacitance;
If the maximal value rate of change that S52. H2 ' compares H2 do not exceed ± 5%, and maximal value rate of change that H1 ' compares H1 exceed ± 5%, then judge test product non-fault and vibrate inductance or load capacity there occurs fault.
The maximal value rate of change that S53. if H2 ' compares H2 exceedes ± and 5%, no matter H1 ' compares the maximal value rate of change of H1, all judge that test product there occurs fault.
Therefore this method for diagnosing faults is applied in dry reactor higher-order of oscillation impulse voltage withstand test, is carried out the fault diagnosis of test product by the transport function asking for tested dry reactor.By compare diverse location place with the transport function maximal value under different tests voltage, can judge different faults in dry reactor higher-order of oscillation impulse voltage withstand test, which includes the fault diagnosis of test loop components and parts, avoid the erroneous judgement because test loop components and parts fault causes.
Accompanying drawing explanation
Fig. 1 is the connection schematic diagram of test loop of the present invention;
Fig. 2 is Troubleshooting Flowchart in the present invention.
Embodiment
Below in conjunction with accompanying drawing, by specific embodiment, the present invention will be further described.
As shown in Figure 1, in the present invention, dry reactor high-frequency percussion withstand voltage test loop mainly comprises standard impulse voltage generator 1, first voltage divider 2, first shunt 3, vibration inductance 4, load capacity 5, tested dry reactor 6, second shunt 7 and the second voltage divider 8.
Wherein, under the Impulse Voltage that standard impulse voltage generator produces, discharge test is carried out to tested dry reactor 6, load capacity 5 is in parallel with tested dry reactor 6 place circuit branch, and the branch road formed in parallel is connected in series formation loop with vibration inductance 4, standard impulse voltage generator 1.
, in this test loop, the voltage and current of specific location is measured: the first voltage divider 2 is in parallel with standard impulse voltage generator meanwhile, therefrom obtain voltage signal U1; Second voltage divider 8 is in parallel with tested dry reactor 6, thus obtains voltage signal U2; First shunt 3 is connected with vibration inductance 4, obtains current signal I1; After second shunt 7 is connected with tested dry reactor 6, obtain current signal I2.
Finally, according to U1 measured under different tests voltage, I1, U2, I2, and based on the calculating of transport function, carry out the diagnosis of different faults.
This concrete troubleshooting step as shown in Figure 2, by first after-applied different trial voltage, record the U1 under different tests voltage, I1, U2, I2, ask for the transport function that U1, I1 are relevant under different tests voltage respectively, and U2, the transport function that I2 is relevant, finally carries out fault diagnosis according to the situation of change of two groups of transport functions under different tests voltage.
In a specific embodiment, this dry reactor higher-order of oscillation impulse voltage withstand test troubleshooting step comprises:
S10. 50% trial voltage is applied to tested dry reactor, obtain U1, I1, U2, I2;
S20. according to U1 and I1 calculation of transfer function H1, according to U2 and I2 calculation of transfer function H2;
Wherein, the specific formula for calculation of transport function is
voltage signal is transformed into frequency domain by fast fourier transform to obtain frequency domain distribution by fft (U), and current signal is transformed into frequency domain by fast fourier transform and obtains frequency domain and divide by fft (I)
Cloth, and then, at frequency domain, voltage signal and current signal are carried out than acquisition transfer function H;
S30. 100% trial voltage is applied to tested dry reactor, obtains U1 ', I1 ', U2 ', I2 ';
S40. according to U1 ' and I1 ' calculation of transfer function H1 ', according to U2 ' and I2 ' calculation of transfer function H2 ';
S50. H1 is compared, H2 and H1 ', H2 ', carry out fault diagnosis according to its situation of change.
Wherein, H1, H2 and H1 in step S5 ', the situation of change of H2 ', can be embodied by the rate of change of its maximal value.In one more specifically embodiment, the fault diagnosis in step S50 can comprise following concrete determining step:
The maximal value rate of change that S51. if H1 ' compares H1 and H2 with the maximal value of H2 ' all do not exceed ± and 5%, then judge this test product and vibration inductance, the equal non-fault of load capacitance;
If the maximal value rate of change that S52. H2 ' compares H2 do not exceed ± 5%, and maximal value rate of change that H1 ' compares H1 exceed ± 5%, then judge test product non-fault and vibrate inductance or load capacity there occurs fault.
The maximal value rate of change that S53. if H2 ' compares H2 exceedes ± and 5%, no matter H1 ' compares the maximal value rate of change of H1, all judge that test product there occurs fault.
Visible, based on method for diagnosing faults of the present invention, fault diagnosis is carried out with the transport function maximal value under different tests voltage by what compare diverse location place, each components and parts in test loop can be obtained and whether produce fault, thus when dry reactor high-frequency percussion withstand voltage test, avoid the erroneous judgement because test loop components and parts fault causes.
Here description of the invention and application is illustrative, not wants by scope restriction of the present invention in the above-described embodiments.Distortion and the change of embodiment disclosed are here possible, are known for the replacement of embodiment the ordinary skill of those this areas is arbitrary and the various parts of equivalence.Art technology is arbitrary to be noted that when not departing from spirit of the present invention or essential characteristic, the present invention can in other forms, structure, layout, ratio, and to realize with other assembly, material and parts.When not departing from the scope of the invention and spirit, can other distortion be carried out here to disclosed embodiment and change.