CN203249991U - Device applied to transformer induction voltage test - Google Patents
Device applied to transformer induction voltage test Download PDFInfo
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- CN203249991U CN203249991U CN 201320232491 CN201320232491U CN203249991U CN 203249991 U CN203249991 U CN 203249991U CN 201320232491 CN201320232491 CN 201320232491 CN 201320232491 U CN201320232491 U CN 201320232491U CN 203249991 U CN203249991 U CN 203249991U
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Abstract
The utility model discloses a device applied to a transformer induction voltage test. The device comprises a frequency conversion power supply, a test transformer, a compensation reactor, a measurement voltage divider, detection impedance, a resonant capacitor, an alternating current voltage meter and a partial discharge test device. Without accessing a tested transformer, the compensation reactor is connected in parallel with the resonant capacitor to enable the test device to form a parallel resonant circuit, so that the test device can effectively work. Under the condition, partial discharge of the device is measured. Due to the fact that the resonant capacitor is used to replace the tested transformer, the influence of discharge of the tested transformer on the test device is avoided. According to the utility model, foreign interference is excluded; partial discharge of the test device is accurately measured; calibrating can be carried out on the device before the test.
Description
Technical field
The utility model relates to partial discharge of transformer proving installation field, particularly, relates to a kind of device for the transformer induction voltage test.
Background technology
Induced voltage test (ACLD) can be in order to simulate the reliability of transient over-voltage and continuous working voltage effect when growing at present.And additional measurement of partial discharge test can be used for surveying the inner non-penetrability defective of transformer.
When the inner generation of medium shelf depreciation, the inner mobile quantity of electric charge is called the actual discharge amount, because actual discharge is to carry out in medium inside, its discharge capacity can't be measured.But according to the analysis of prior art, there are certain incidence relation in Apparent discharge magnitude and actual discharge amount, can indirectly obtain the actual discharge amount by measuring Apparent discharge magnitude.In a test product such as transformer, the Apparent discharge magnitude that varies in size may appear simultaneously, the stable maximum Apparent discharge magnitude that occurs is called the discharge capacity of shelf depreciation.
During shelf depreciation, the test product two ends produce an almost instantaneous change in voltage.According to the pulse current ratio juris, if test product is linked into the detection loop, will produce pulse current, measure pulse current with a highly sensitive electronic device, just can judge whether to exist shelf depreciation, and detect its strength of discharge.In the prior art, measure shelf depreciation and have direct method and balancing method.Be direct method as shown in Figure 1a, test product equivalent capacity Cx is in parallel with coupling capacitance Ck, measures impedance Z m and connects with coupling condenser Ck.Be depicted as the another kind of connection of direct method such as Fig. 1 b, test product equivalent capacity Cx is in parallel with coupling capacitance Ck, measures impedance Z m and connects with coupling condenser Cx, and Ck is in parallel with coupling condenser.Wherein M is the measurement of partial discharge instrument, and Zf is the hv filtering device.
The existing pulse current method that utilizes is measured single-phase two-winding transformer induced voltage test loop.Wherein, test unit and tested transformer have been comprised.Wherein test unit comprises AC380V power supply, variable-frequency power sources, testing transformer, compensation reactor, measurement voltage divider.Three AC power are by the low-pressure side of variable-frequency power sources access testing transformer.The high-pressure side of testing transformer is connected with the input side of being tested transformer, is parallel with compensation reactor in the high-pressure side of testing transformer and measures voltage divider.Control desk connects variable-frequency power sources by optical cable., when testing for power transformer, usually utilize the bushing of tested transformer self as coupling capacitance, detect impedance in bottom shielding of bushing series connection access and measure.
But according to technical standard and testing requirements, partial discharge of transformer can not be greater than 500pC.This is a smaller amount, in the middle of particularly testing at the scene.Therefore, when partial discharge of transformer is tested, get rid of the outside interference particular importance that becomes.And the discharge in the test unit, on measuring impact greatly.If there is larger discharge in test unit, for example, greater than 5000pC, and conduct to test product, namely tested transformer 140 will have the interference to hundreds of pC in tested transformer, cause and can't judge that shelf depreciation is from tested transformer, or from the interference of test unit; Therefore, test unit is carried out discharge capacity calibration, when particularly recording shelf depreciation and being above standard, when namely having larger discharge capacity, be difficult to judge the source of shelf depreciation.
Therefore, present local discharge measuring method has following shortcoming: (1) can't before test, calibrate device specially; (2) can't carry out quantitatively can not grasping the concrete value of device shelf depreciation to calibration; (3) for the normal test product revision test of other discharge capacities, there is the risk of accelerating insulation ag(e)ing for test product; (4) pinpoint the problems in the site test after, can't in time solve.
The utility model content
The purpose of this utility model is, for the problems referred to above, a kind of device for the transformer induction voltage test is proposed, with realize getting rid of external interference Measurement accuracy test unit self shelf depreciation and can be used for testing before advantage that device is calibrated.
For achieving the above object, the technical solution adopted in the utility model is:
A kind of device for the transformer induction voltage test comprises variable-frequency power sources, testing transformer, compensation reactor, measurement voltage divider, detects impedance, resonant capacitance, A.C. voltmeter and instrument for measuring partial discharge,
External ac power source is connected electrically in the low-pressure side of testing transformer by variable-frequency power sources, described compensation reactor and measurement voltage divider are connected in parallel on the high-pressure side of testing transformer, and measuring voltage divider is formed by capacitor C 1 and 2 two capacitances in series of capacitor C, described capacitor C 1 is for measuring the high-voltage capacitance arm of voltage divider, and capacitor C 2 is for measuring the low-voltage capacitance arm of voltage divider;
The input end of described detection impedance is connected electrically in the junction of capacitor C 1 and 2 two electric capacity arms of capacitor C, and described instrument for measuring partial discharge is connected electrically in the output terminal that detects impedance, is used for measuring the shelf depreciation of this device;
Described A.C. voltmeter is connected electrically in the junction of capacitor C 1 and capacitor C 2;
Described resonant capacitance is connected in parallel on the two ends of compensation reactor, and the value of the capacitance of this resonant capacitance and compensation reactor can in the 100-300Hz frequency range parallel resonance occur.
Further, described resonant capacitance is that 30-300Hz and voltage are that shelf depreciation under the 120kV is less than 10pC in frequency of operation.
Further, the specified inductance of described compensation reactor is 1.1H, rated voltage 120kV, rated current 30A, described capacitor C 1 is 1000pF, rated voltage 120kV, described capacitor C 2 is 1 μ F, rated voltage 1kV, the specified intrinsic standoff ratio 1000:1 of described capacitive divider.
Further, when being used for the transformer induction voltage test of 750kV, the capacitance span of described resonant capacitance is 1.8 μ F-2.2 μ F.
Further, when being used for the transformer induction voltage test of 750kV, the capacitance value 2 μ F of described resonant capacitance.
Further, when being used for the transformer induction voltage test of 220kV, the capacitance span of described resonant capacitance is 0.2-0.3 μ F;
Further, when being used for the transformer induction voltage test of 330kV, the capacitance span of described resonant capacitance is 0.2-0.5 μ F.
The technical solution of the utility model has following beneficial effect:
The technical solution of the utility model, in the situation that do not access tested transformer, so that test unit can form the shunt-resonant circuit test unit is effectively worked for a compensation reactor resonant capacitance in parallel, and in the shelf depreciation of measuring in such cases this device, replace tested transformer because using resonant capacitance, thereby avoided the discharge of tested transformer on the impact of test unit, reached when getting rid of external interference Measurement accuracy test unit self shelf depreciation and can be used for testing before purpose that device is calibrated.And under different voltage requests, resonant capacitance is further limited span, can further limit the resonant capacitance discharge to the impact of test.
Below by drawings and Examples, the technical solution of the utility model is described in further detail.
Description of drawings
Fig. 1 a and Fig. 1 b are the circuit diagram that the available technology adopting direct method is measured shelf depreciation;
Fig. 2 is the circuit diagram of the device for the transformer induction voltage test described in the utility model.
By reference to the accompanying drawings, Reference numeral is as follows among the utility model embodiment:
The 100-variable-frequency power sources; The 110-testing transformer; The 120-compensation reactor; 130-measures voltage divider; 160-detects impedance; The 170-control desk; 180-instrument for measuring partial discharge; The 190-A.C. voltmeter; The 200-resonant capacitance.
Embodiment
Below in conjunction with accompanying drawing preferred embodiment of the present utility model is described, should be appreciated that preferred embodiment described herein only is used for description and interpretation the utility model, and be not used in restriction the utility model.
As shown in Figure 2, a kind of device for the transformer induction voltage test, comprise variable-frequency power sources 100, testing transformer 110, compensation reactor 120, measure voltage divider 130, detect impedance 160, resonant capacitance 200, A.C. voltmeter 190 and instrument for measuring partial discharge 180
External ac power source is connected electrically in the low-pressure side of testing transformer 110 by variable-frequency power sources 100, compensation reactor 120 and measurement voltage divider 130 are connected in parallel on the high-pressure side of testing transformer 110, and measuring voltage divider 130 is formed by capacitor C 1 and 2 two capacitances in series of capacitor C, capacitor C 1 is for measuring the high-voltage capacitance arm of voltage divider 130, and capacitor C 2 is for measuring the low-voltage capacitance arm of voltage divider 130; The input end that detects impedance 160 is connected electrically in the junction of capacitor C 1 and 2 two electric capacity arms of capacitor C, and instrument for measuring partial discharge 180 is connected electrically in the output terminal that detects impedance 160, is used for measuring the shelf depreciation of this device; A.C. voltmeter 190 is connected electrically in the junction of capacitor C 1 and capacitor C 2; Resonant capacitance 200 is connected in parallel on the two ends of compensation reactor 120, and the value of the capacitance of this resonant capacitance 200 and compensation reactor 120 can in the 100-300Hz frequency range parallel resonance occur.
Wherein resonant capacitance 200 is that 30-300Hz and voltage are that shelf depreciation under the 120kV is less than 10pC in frequency of operation.The specified inductance of compensation reactor 120 is 1.1H, rated voltage 120kV, and rated current 30A, capacitor C 1 is 1000pF, rated voltage 120kV, capacitor C 2 is 1 μ F, rated voltage 1kV, the specified intrinsic standoff ratio 1000:1 of capacitive divider.The value of C1 and C2 can need to come to determine according to concrete measurement intrinsic standoff ratio and the corresponding capacitance value of the two in the practical application.
Control desk 170 connects variable-frequency power sources 100 by optical cable, with the output of control variable-frequency power sources.
When working like this, C1 serves a dual purpose: the high-voltage capacitance arm of (1) voltage-dividing capacitor; (2) measure the needed coupling capacitance of shelf depreciation,
The value principle of the electric capacity of resonant capacitance 200 is as mentioned before: in the existing test unit for the tested transformer adopting equivalent electric capacity of outside suitable without office's discharge vessel as resonant capacitance 200, thereby can simulate the state of tested transformer when testing, and the shelf depreciation of Measurement accuracy test unit self.
The value principle of compensation reactor 120 inductance value in the test unit is: can in the 100-300Hz scope parallel resonance occur with resonant capacitance 200, thereby under the condition that is higher than 2 times of power frequencies, tested transformer be carried out induced voltage test.
Particularly, the selection of the parameter of resonant capacitance 200 should be for the parameter of the tested transformer that will test.For example, operating voltage is 750kV, is that the method for 330kV, 220kV transformer test device measurement of partial discharge is identical with operating voltage, the capacity difference of the resonant capacitance 200 that just adopts.In following embodiment, take operating voltage as 750 kV as example, set forth the adopting parameters of resonant capacitance 200.
Because the equivalent electric capacity of tested transformer 140 is scopes, for 750kV, resonant capacitance 200 is chosen 1.8 μ F-2.2 μ F, preferably, the electric capacity of resonant capacitance 200 is 2 μ F, and very near actual equivalent capacity, test effect is better for resonant capacitance 200 like this.
For the tested transformer of 750kV, low-pressure side only needs to input 94.5kV.Therefore, one of resonant capacitance 200 minute power-frequency withstand voltage is 70kV-140kV.This scope satisfies fully under 94.5kV works, and measures the requirement of shelf depreciation.Preferably, the rated voltage of resonant capacitance 200 is 70kV, and this voltage belongs to the category of the class B insulation such as 66kV, and ripe product is arranged, and nargin is reasonable.Rated voltage is low again, does not then satisfy the trial voltage requirement, and when rated voltage is higher than 140kV, then nargin is excessive.
The frequency of operation of resonant capacitance 200 is similar to the trial voltage frequency, is 30-300Hz, is preferably 100-300Hz, to avoid the unshakable in one's determination saturated of transformer.
The shelf depreciation of resonant capacitance 200 be under the 120kV less than 10pC, under the 140kV less than 100pC.Because therefore test unit under normal circumstances discharge capacity itself, needs only resonant capacitance 200 self-discharges less than order of magnitude of test unit discharge capacity at 1000pC, just can ignore the impact of measuring.
For example, the flow process that adopts transformer induction voltage test device described in the utility model to carry out the method for measurement of partial discharge can be come reference implementation in the following manner:
1, power-on;
2, adjust the variable-frequency power sources output voltage frequency, make compensation reactor and resonance capacitor loop resonance;
3, rising trial voltage, the high side voltage that makes testing transformer 110 is the first high side voltage, keeps 1 minute, measures shelf depreciation;
4, continue the rising trial voltage, the high side voltage that makes testing transformer 110 is the second high side voltage, keeps 1 minute, measures shelf depreciation.
Wherein the first high side voltage is
, i.e. 69.3kV, the second high side voltage is
, i.e. 94.5kV, this is alternative value of the shelf depreciation in the induced voltage test device of measuring 750kV grade transformer.
Should know, the method also can be applied to measurement and the calibration of shelf depreciation in the induced voltage test device of 330kV, 220kV transformer, these two electric pressure transformer test device principles and 750kV grade transformer are identical, and the equipment configuration is also identical, and just parameter is different.When calibrating for different transformers, the electric capacity of corresponding resonant capacitance should be chosen according to the equivalent capacity of tested transformer, makes resonant capacitance in the 100-300Hz scope resonance occur with compensation reactor, the state of simulation actual tests.
For 220kV, 330kV transformer, its equivalent capacity is less.Therefore, when shelf depreciation was measured and calibrated in for the induced voltage test device of 220kV transformer, the resonant capacitance capacity was 0.2-0.3 μ F, be preferably 0.25 μ F, during test, preferred, described the first high side voltage is 11kV, and described the second high side voltage is 15kV.
When calibrating for the 330kV transformer, the desirable 0.2-0.5 μ of resonant capacitance capacity F is preferably 0.35 μ F.During test, preferred, described the first high side voltage is 38.5kV, and described the second high side voltage is 52.5kV.
This shows, the utility model adopts resonant capacitance in parallel with test unit, measure the shelf depreciation of test unit under condition of resonance, resonant capacitance scope suitable with tested transformer equivalent capacity, thereby shelf depreciation that can the precise quantification test unit, the shelf depreciation of transformer induction voltage test is measured and calibrated, thereby avoiding using the larger test unit of shelf depreciation to test causing solves a problem promptly error.
Selection 750kV, the 220kV of above-mentioned three magnitudes of voltage and 330kV often use in just testing, those skilled in the art is according to the technical solution of the utility model and habitual technological means, can realize easily the transformer beyond these 3 voltages is tested, in this technical scheme, will other magnitude of voltage not enumerated.
It should be noted that at last: the above only is preferred embodiment of the present utility model, be not limited to the utility model, although with reference to previous embodiment the utility model is had been described in detail, for a person skilled in the art, it still can be made amendment to the technical scheme that aforementioned each embodiment puts down in writing, and perhaps part technical characterictic wherein is equal to replacement.All within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., all should be included within the protection domain of the present utility model.
Claims (7)
1. device that is used for the transformer induction voltage test is characterized in that: comprises variable-frequency power sources, testing transformer, compensation reactor, measurement voltage divider, detects impedance, resonant capacitance, A.C. voltmeter and instrument for measuring partial discharge,
External ac power source is connected electrically in the low-pressure side of testing transformer by variable-frequency power sources, described compensation reactor and measurement voltage divider are connected in parallel on the high-pressure side of testing transformer, and measuring voltage divider is formed by capacitor C 1 and 2 two capacitances in series of capacitor C, described capacitor C 1 is for measuring the high-voltage capacitance arm of voltage divider, and capacitor C 2 is for measuring the low-voltage capacitance arm of voltage divider;
The input end of described detection impedance is connected electrically in the junction of capacitor C 1 and 2 two electric capacity arms of capacitor C, and described instrument for measuring partial discharge is connected electrically in the output terminal that detects impedance, is used for measuring the shelf depreciation of this device;
Described A.C. voltmeter is connected electrically in the junction of capacitor C 1 and capacitor C 2;
Described resonant capacitance is connected in parallel on the two ends of compensation reactor, and the value of the capacitance of this resonant capacitance and compensation reactor can in the 100-300Hz frequency range parallel resonance occur.
2. the device for the transformer induction voltage test according to claim 1 is characterized in that:
Described resonant capacitance is that 30-300Hz and voltage are that shelf depreciation under the 120kV is less than 10pC in frequency of operation.
3. the device for the transformer induction voltage test according to claim 1 is characterized in that:
The specified inductance of described compensation reactor is 1.1H, rated voltage 120kV, and rated current 30A, described capacitor C 1 is 1000pF, rated voltage 120kV, described capacitor C 2 is 1 μ F, rated voltage 1kV, the specified intrinsic standoff ratio 1000:1 of described capacitive divider.
4. be used for according to claim 1 the device of transformer induction voltage test to 3 arbitrary described devices, it is characterized in that: when being used for the transformer induction voltage test of 750kV, the capacitance span of described resonant capacitance is 1.8 μ F-2.2 μ F.
5. device according to claim 4 is used for the device of transformer induction voltage test, it is characterized in that:
When being used for the transformer induction voltage test of 750kV, the capacitance value 2 μ F of described resonant capacitance.
6. according to claim 1 to 3 arbitrary described devices for the transformer induction voltage test,, it is characterized in that:
When being used for the transformer induction voltage test of 220kV, the capacitance span of described resonant capacitance is 0.2-0.3 μ F.
7. according to claim 1 to 3 arbitrary described devices for the transformer induction voltage test, it is characterized in that:
When being used for the transformer induction voltage test of 330kV, the capacitance span of described resonant capacitance is 0.2-0.5 μ F.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320232491 CN203249991U (en) | 2013-05-02 | 2013-05-02 | Device applied to transformer induction voltage test |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201320232491 CN203249991U (en) | 2013-05-02 | 2013-05-02 | Device applied to transformer induction voltage test |
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| CN203249991U true CN203249991U (en) | 2013-10-23 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103278753A (en) * | 2013-05-02 | 2013-09-04 | 国家电网公司 | Device for induced voltage tests on transformers |
| CN104914365A (en) * | 2015-06-12 | 2015-09-16 | 国网天津市电力公司 | Detection device and method for improving partial discharge detection sensitivity |
| CN107436399A (en) * | 2017-06-30 | 2017-12-05 | 国家电网公司 | High altitude localities 750kV shunt reactor local discharge test devices |
| CN111562475A (en) * | 2020-06-10 | 2020-08-21 | 国网山西省电力公司电力科学研究院 | Circuit for detecting partial discharge amount of variable frequency power supply for high-voltage test and evaluation method |
| WO2023106961A1 (en) * | 2021-12-08 | 2023-06-15 | Федеральное Государственное Унитарное Предприятие "Российский Федеральный Ядерный Центр - Всероссийский Научно - Исследовательский Институт Технической Физики Имени Академика Е.И. Забабахина" | Mobile high-voltage apparatus for testing power transformers |
-
2013
- 2013-05-02 CN CN 201320232491 patent/CN203249991U/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103278753A (en) * | 2013-05-02 | 2013-09-04 | 国家电网公司 | Device for induced voltage tests on transformers |
| CN104914365A (en) * | 2015-06-12 | 2015-09-16 | 国网天津市电力公司 | Detection device and method for improving partial discharge detection sensitivity |
| CN104914365B (en) * | 2015-06-12 | 2017-08-29 | 国网天津市电力公司 | A kind of detection means and method for improving Partial Discharge Detection sensitivity |
| CN107436399A (en) * | 2017-06-30 | 2017-12-05 | 国家电网公司 | High altitude localities 750kV shunt reactor local discharge test devices |
| CN111562475A (en) * | 2020-06-10 | 2020-08-21 | 国网山西省电力公司电力科学研究院 | Circuit for detecting partial discharge amount of variable frequency power supply for high-voltage test and evaluation method |
| WO2023106961A1 (en) * | 2021-12-08 | 2023-06-15 | Федеральное Государственное Унитарное Предприятие "Российский Федеральный Ядерный Центр - Всероссийский Научно - Исследовательский Институт Технической Физики Имени Академика Е.И. Забабахина" | Mobile high-voltage apparatus for testing power transformers |
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Granted publication date: 20131023 |