CN113820598A - Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded - Google Patents
Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded Download PDFInfo
- Publication number
- CN113820598A CN113820598A CN202111159327.XA CN202111159327A CN113820598A CN 113820598 A CN113820598 A CN 113820598A CN 202111159327 A CN202111159327 A CN 202111159327A CN 113820598 A CN113820598 A CN 113820598A
- Authority
- CN
- China
- Prior art keywords
- generator
- current
- voltage
- direct
- test
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 81
- 238000010998 test method Methods 0.000 title claims abstract description 25
- 238000012360 testing method Methods 0.000 claims abstract description 103
- 238000004804 winding Methods 0.000 claims abstract description 46
- 238000000034 method Methods 0.000 claims abstract description 37
- 238000009413 insulation Methods 0.000 claims abstract description 35
- 230000007547 defect Effects 0.000 claims abstract description 12
- 230000008569 process Effects 0.000 claims abstract description 9
- 230000008859 change Effects 0.000 claims description 9
- 238000012544 monitoring process Methods 0.000 claims description 5
- 238000001514 detection method Methods 0.000 abstract description 5
- 230000000694 effects Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 230000005283 ground state Effects 0.000 description 3
- 230000008439 repair process Effects 0.000 description 3
- 238000000861 blow drying Methods 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000001066 destructive effect Effects 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000009422 external insulation Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/34—Testing dynamo-electric machines
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Tests Of Circuit Breakers, Generators, And Electric Motors (AREA)
Abstract
The invention provides a direct-current withstand voltage test method after a generator water collecting pipe is fixedly grounded, and relates to the field of generator detection equipment. The test method comprises the steps that a direct-current high-voltage generator special for the water-cooled generator is adopted to carry out a water-carrying direct-current withstand voltage test on the generator with a dead-grounded water collecting pipe, a stator winding of the generator is subjected to a grouping test, during each group of tests, the direct-current high voltage provided by the direct-current high-voltage generator special for the water-cooled generator is controlled to gradually increase to required test voltage, and in the boosting process, the total current of a loop is monitored and read through an ammeter connected in series to the high-voltage side; if the difference value of the total current of the loops of each group does not exceed the set range value, the direct current withstand voltage test is passed, and the alternating current withstand voltage test can be carried out; or if the difference value of the total current of the loops of each group exceeds the set range value, stopping pressurizing and searching the defect part. The direct current withstand voltage test with water can be effectively carried out after the water collecting pipe is fixedly grounded, so that the insulation quality of the generator can be judged.
Description
Technical Field
The invention relates to the field of generator detection equipment, in particular to a direct-current withstand voltage test method after a generator water collecting pipe is fixedly grounded.
Background
The direct current and alternating current withstand voltage tests of the generator are important means for judging the insulation quality of the stator winding of the generator. The dc withstand voltage test is effective for finding insulation defects at the end of the stator winding of a generator because the dc voltage applied to the winding has no capacitive effect, there is no capacitive current, and the voltage drop between the copper wire with the winding and the external insulation surface is quite high. The power frequency alternating current withstand voltage test is effective for finding the insulation defect of the slot part of the stator winding of the generator, because when 50Hz power frequency alternating current voltage is added, the electric field is not uniformly distributed due to the capacitance effect, the electric field born by the insulation of the slot part of the crystalline iron core is stronger, and the voltage is higher. Therefore, the two tests are complementary and cannot be used instead. The reason that the DC withstand voltage test is performed before the AC withstand voltage test is that the DC withstand voltage is easier to find the end defects and the gap defects of the generator, the defects can be found or found before the insulation is broken down, and the insulation damage degree of the generator is smaller than that of the AC withstand voltage test.
The direct-current voltage withstand test belongs to a destructive test, and the direct-current voltage withstand test can damage equipment to a certain extent in the test process and is used for detecting the maximum voltage peak value borne by the equipment under the high-voltage test. It is convenient to determine the range of use of the device and to select the range of use of the device. The direct-current withstand voltage test is used for checking the capacity of an insulating medium of electrical equipment for withstanding a direct-current high voltage, and is substantially equivalent to applying the direct-current high voltage to two ends of a capacitor, checking whether the insulating medium between two polar plates of the capacitor passes through a test for a specified time under the action of a high-voltage electric field, and observing whether an abnormal condition occurs, wherein the withstand voltage strength can be reached to pass through the test check, and a person with abnormal changes of discharge, breakdown or leakage current cannot pass through the test check.
A water-hydrogen cooling type thermal generator set is characterized in that a water collecting pipe of the thermal generator set is grounded into an openable type and a fixed grounded type, and the openable type is convenient for carrying out a direct-current withstand voltage test; the fixed grounding type is generally used for carrying out tests after a blow-drying water collecting pipe, the operation process is complicated, and the phenomenon that blow-drying cannot be thoroughly carried out exists. When the openable water collecting pipe is in dead ground due to some reason and the condition is limited at the time and cannot be solved, the method for drying the water collecting pipe is time-consuming and labor-consuming, and partial discharge is possibly generated at the position where the blowing is not clean.
Because the water collecting pipe is in dead ground, the insulation resistance of the generator cannot be tested by the conventional means under the condition that the generator is supplied with water, the direct-current withstand voltage cannot be tested, and the insulation state of the generator can be judged only by the alternating-current withstand voltage (destructive test). Direct ac voltage withstand is likely to cause a large risk.
In view of this, the present application is specifically made.
Disclosure of Invention
The invention aims to provide a direct current voltage withstand test method after a generator water collecting pipe is fixedly grounded, which can effectively solve the problem that a direct current voltage withstand test with water is carried out after the water collecting pipe is fixedly grounded so as to judge whether the generator is insulated or not.
Embodiments of the invention may be implemented as follows:
in a first aspect, the invention provides a direct current withstand voltage test method after a generator catchment pipe is fixedly grounded, which comprises the steps of carrying out a direct current withstand voltage test with water on a generator with a catchment pipe which is grounded dead by adopting a direct current high-voltage generator special for a water-cooled generator;
controlling the direct-current high-voltage generator special for the water-cooled generator to provide direct-current high voltage for the direct-current withstand voltage test, performing a grouping test on a stator winding of the generator, controlling the direct-current high voltage provided by the direct-current high-voltage generator special for the water-cooled generator to gradually increase to required test voltage during each group of tests, and monitoring and reading the total current of a loop through an ammeter connected in series with the high-voltage side in the boosting process;
if the difference value of the total current of each group of loops is monitored not to exceed the set range value, the direct current withstand voltage test is passed, and the alternating current withstand voltage test can be carried out; or;
and if the difference value of the total current of each group of loops is monitored to exceed the set range value, stopping pressurizing and searching the defect part.
In an alternative embodiment, the ammeter is a pointer ammeter.
In an alternative embodiment, the ammeter is a milliammeter.
In an alternative embodiment, the set range value is such that the difference in current ratios between the three phases does not exceed 50%.
In an alternative embodiment, the test voltage is increased in stages by 0.5Un per stage, the test voltage stays for 1min per stage, the change degree of the current is monitored, and then the next stage of voltage increase is carried out until the test voltage is reduced after the test is completed.
In an alternative embodiment, the test voltage is at most 2.5 Un.
In an optional embodiment, the voltage is increased at a voltage increasing speed of 1-3Kv/s in the voltage increasing process, and the current of the ammeter does not exceed the maximum charging current of the direct-current high-voltage generator special for the water-cooled generator during voltage increasing.
In an optional embodiment, the dc high voltage generator dedicated for the water-cooled generator includes a case, a voltage doubling cylinder, an ammeter, a current limiting resistor, an overvoltage protection device, a discharge rod, and a ground wire set, the generator includes a stator winding, an equivalent water resistor, a water collecting pipe, and a rotor winding, the case receives a power supply and controls the voltage doubling cylinder to generate a set high voltage, the voltage doubling cylinder feeds back a current value to the case through a measurement terminal, a high voltage output end of the voltage doubling cylinder is electrically connected to a voltage in the stator winding, the ammeter, the current limiting resistor, and the overvoltage protection device are connected in series between the voltage doubling cylinder and the stator winding, a water collecting pipe interface end of the case is simultaneously electrically connected to the water collecting pipe and the overvoltage protection device, the water collecting pipe is grounded, the rotor winding is grounded, a ground terminal of the case, And the grounding end of the voltage doubling cylinder, the two-phase non-pressurized phase in the stator winding and the discharge rod are electrically connected with the grounding wire group.
In a second aspect, the present invention provides a method for detecting an insulation state of a generator, which is applied to a case where a water collection pipe is in a dead ground state and water flows, wherein the method for testing a direct current withstand voltage after the water collection pipe of the generator is in a fixed ground state as in any one of the above embodiments is performed, and the method for testing a direct current withstand voltage after the water collection pipe of the generator is in a fixed ground state is performed, and then, an alternating current withstand voltage test is performed.
The beneficial effects of the embodiment of the invention include, for example:
the dc voltage withstand test method after the generator catchment pipe is fixedly grounded provided by this embodiment mainly aims at the situation that the catchment pipe is fixedly grounded, cannot be uncovered, is in a water-through state, and is difficult to dry, because the catchment pipe cannot be shielded by the fixed ground at this time, if the catchment pipe has insulation defects, the water current in the catchment pipe is large, the ammeter used for detecting the leakage current of the stator winding by the conventional low-voltage shielding method cannot measure, the dc voltage withstand test method after the generator catchment pipe is fixedly grounded adopts the ammeter arranged on the high-voltage side to monitor and read the total current of the loop by the ammeter, and the insulation state of the stator winding can be judged by only monitoring the degree of the ammeter between each phase of the stator winding and judging the difference value, and the dc voltage withstand test method provided by this application can solve the existing test error zone, and increasing the basis for judging the insulation state of the generator. Because the insulation resistance and the DC withstand voltage principle are the same, the DC withstand voltage result can be directly used for replacing the insulation resistance result. The generator with the catchment pipe dead-grounded is characterized in that when the unit is in minor repair (the rotor is not pumped), regulations specify (DL/T-1768-. The method for detecting the insulation state of the generator provided by the embodiment is suitable for the conditions that the water collection pipe is in dead ground and water flows, the direct-current withstand voltage test method after the water collection pipe of the generator is fixedly grounded is firstly carried out, and the alternating-current withstand voltage test is carried out after the direct-current withstand voltage test method after the water collection pipe of the generator is fixedly grounded passes.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a test circuit wiring diagram of a direct-current high-voltage generator dedicated to a water-cooled generator according to an embodiment of the present application.
Icon: 100-a special direct-current high-voltage generator for a water-cooled generator; 101-a case; 102-time pressing cylinder; 103-an ammeter; 104-current limiting resistor; 105-overvoltage protection; 106-stator windings; 107-equivalent water resistance; 108-a water collecting pipe; 109-rotor windings; 110-a discharge rod; 111-ground line group.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.
Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.
Examples
Referring to fig. 1, the embodiment provides a direct current withstand voltage test method after a generator header 108 is fixedly grounded, which mainly aims at performing a direct current withstand voltage test after the generator header 108 is fixedly grounded, so that the problem that the direct current withstand voltage test cannot be performed when the generator header 108 is fixedly grounded in the conventional case and the direct current withstand voltage test can still be performed by using the method provided by the present application under the condition that the generator header 108 cannot be completely dried is effectively solved, and the safety of the test is improved.
Specifically, in the present embodiment, the water-cooled generator dedicated dc high-voltage generator 100 is used to perform the dc voltage withstand test with water on the generator with the water collecting pipe 108 in a dead state, and before performing the dc voltage withstand test, the connection needs to be performed according to the test loop (as shown in fig. 1). In this application, the dc high voltage generator 100 dedicated for water-cooled generator includes a case 101, a voltage-multiplying cylinder 102, an ammeter 103, a current-limiting resistor 104, an overvoltage protection device 105, a discharging rod 110 and a ground wire set 111, the generator includes a stator winding 106, the device comprises an equivalent water resistor 107, a water collecting pipe 108 and a rotor winding 109, wherein a case 101 receives a power supply and controls a voltage doubling cylinder 102 to generate a set high voltage, the voltage doubling cylinder 102 feeds a current value back to the case 101 through a measuring terminal, a high-voltage output end of the voltage doubling cylinder 102 is electrically connected with a pressurizing phase in a stator winding 106, an ammeter 103, a current limiting resistor 104 and an overvoltage protection device 105 are connected between the voltage doubling cylinder 102 and the stator winding 106 in series, a water collecting pipe 108 interface end of the case 101 is simultaneously and electrically connected with the water collecting pipe 108 and the overvoltage protection device 105, the water collecting pipe 108 is dead-grounded, the rotor winding 109 is grounded, and a grounding end of the case 101, a grounding end of the voltage doubling cylinder 102, a two-phase non-pressurizing phase in the stator winding 106 and a discharge rod 110 are electrically connected with a grounding wire group 111.
When a water-carrying direct current pressure resistance test is carried out, the method specifically comprises the following steps:
s1, when carrying out the water-carrying DC voltage withstand test, controlling the special DC high-voltage generator 100 for the water-cooling generator to provide DC high voltage for the DC voltage withstand test, carrying out the grouping test on the stator winding 106 of the generator, when each group of tests, controlling the special DC high-voltage generator 100 for the water-cooling generator to provide DC high voltage to gradually increase to the required test voltage, and monitoring and reading the total current of the loop through the ammeter 103 connected in series at the high-voltage side in the boosting process.
The ammeter 103 in this embodiment is a pointer ammeter 103, the pointer ammeter 103 can better reflect the change degree of the current, and the reading ammeter 103 needs a certain reaction time and has poor sensitivity. Specifically, the ammeter 103 in the present application includes a milliammeter, and the ammeter 103 is connected to the high-pressure side of the voltage doubling cylinder 102, so that the leakage current of the stator winding 106 and the change of the sum of the water current in the water collecting pipe 108 can be monitored, and since the water current in the water collecting pipe 108 basically remains unchanged, if the ammeter 103 has a large increase or swing, i.e., the leakage current of the stator winding 106 is increased, it can be determined that the specific phase insulation effect of the stator winding 106 is not good, and therefore, the present application can determine whether to continue the boosting detection or stop the detection according to the increase amplitude or the swing amplitude of the ammeter 103, and inspect the defect portion.
The test of taking water direct current withstand voltage to the generator in this embodiment includes: the stator winding 106 of the generator is subjected to a grouped direct current withstand voltage test, generally, the stator winding 106 of the generator is divided into three groups, namely A, B and C, the withstand voltage test is carried out in a split-phase manner, the high-voltage output end of the voltage doubling cylinder 102 is electrically connected with a pressurized phase in the stator winding 106, and two non-pressurized phases in the stator winding 106 are electrically connected with a grounding wire group 111 for grounding. In the application, the stator windings 106 of the generator are subjected to grouping tests respectively, each group of tests respectively monitors and reads the total current of the loop, and when the other group is switched to be used as a pressurizing phase, if the total current is obviously increased or swung, the condition that the insulation effect of the stator windings 106 of the group is possibly poor is proved.
In the application, the test voltage is increased in stages according to 0.5Un of each stage, the maximum test voltage is 2.5Un under the condition that the capacity of test equipment is enough, the test voltage stays for 1min in each stage, the change degree of current is monitored, and then the next stage of voltage boosting is carried out until the voltage is reduced after the test is finished.
The boosting speed needs to be uniform, in the application, the boosting speed is increased at 1-3Kv/s in the boosting process, and if the capacity of the tested article is large, the boosting speed needs to be properly slowed down, so that the charges on the tested article are slowly accumulated. During boosting, the current of the ammeter 103 does not exceed the maximum charging current of the dc high voltage generator 100 dedicated to the water-cooled generator, and boosting is performed by monitoring the conditions of the ammeter 103 and the voltmeter at any time.
S2, if the difference value of the total current of the loops of each group does not exceed the set range value (which can also be called as the time when the current does not obviously increase), indicating that the direct current withstand voltage test is passed, and carrying out the alternating current withstand voltage test; specifically, when the total currents of the three groups of loops are transversely compared and the difference is lower than a set range value (the current ratio difference between the three phases does not exceed 50%), the difference is determined to be not obvious, and the insulation of the generator is determined to be better. In other words, when the test voltage value is maintained for a predetermined time, the dc withstand voltage test is considered to pass if the test sample is not discharged destructively and the hand of the ammeter 103 does not suddenly swing in the increasing direction.
Or, if the difference value of the total current of the loops of each group exceeds a set range value (which can also be called as the time when the current is obviously and violently increased), stopping pressurizing, and searching for the defect part by adopting a surface potential outward moving method. In other words, during the test, there are some abnormal situations such as breakdown, flashover, large swing of the ammeter 103, or sudden change of current. Immediately reducing the voltage and cutting off the power supply, finding out the reason, and then performing the test after the treatment is finished.
It should be noted that, there are two current methods for dc voltage withstanding of water-hydrogen cooled generator: high voltage shielding and low voltage shielding. The high-voltage shielding method is characterized in that the microampere meter is connected to a high-voltage end, the influence of impurity dissipation current can be eliminated, the measurement is accurate, when the operation and the reading of the microampere meter are on the high-voltage side, the water collecting pipe 108 is also subjected to high voltage, and the insulation of the water collecting pipe 108 can not meet the requirement. The low-voltage shielding method is to connect one end of the microammeter to the ground and the other end to the low-voltage side of the test transformer, and has low requirement on the insulation resistance of the water collecting pipe 108.
However, the direct-current withstand voltage test method after the generator water collecting pipe 108 is fixedly grounded is different from the conventional high-voltage shielding method and the conventional low-voltage shielding method, and the specific differences are as follows:
the high-voltage shielding method is only suitable for the motor with the water collecting pipe 108 fully insulated, and the generator water collecting pipe 108 at the present stage is low-insulated and can only use the low-voltage shielding method, but the water collecting pipe 108 is fixedly grounded and cannot be detached in the application, at the moment, the insulation of the water collecting pipe 108 is zero, and the water collecting pipe 108 cannot be shielded, so that the existing high-voltage shielding method is not suitable for the specific situation of the application. The special direct-current high-voltage generator 100 for the water-cooled generator only plays a role in providing a high-voltage direct-current source.
Particularly, the high-voltage shielding method and the low-voltage shielding method in the prior art are both performed under the condition that the water collecting pipe 108 is not grounded (that is, under the condition that the water collecting pipe 108 is shielded), and the direct-current withstand voltage test method after the generator water collecting pipe 108 is fixedly grounded provided by the application is performed under the condition that the generator water collecting pipe 108 is fixedly grounded and cannot be separated.
The detection principle of the direct-current withstand voltage test method after the generator water collecting pipe 108 is fixedly grounded is as follows: in the present application, a dc high voltage is provided for a dc withstand voltage test by the dc high voltage generator 100 dedicated for a water-cooled generator, and the ammeter 103 for detecting the total current of the loop is installed on the high voltage side of the voltage doubling cylinder 102, because the water collecting pipe 108 is grounded and cannot be detached in this embodiment, and at this time, the water collecting pipe 108 cannot be shielded under the condition of water supply, so that the dc withstand voltage test cannot be performed by the existing high voltage shielding method or low voltage shielding method, but in this embodiment, the change of the total current of the loop is skillfully used as the basis for the investigation of the dc withstand voltage test, because the total current of the loop includes the leakage current of the pressurized phase of the stator resistance and the water current in the water collecting pipe 108, and the water current in the water collecting pipe 108 remains substantially unchanged, at this time, if the total current of the reflux current changes greatly, it is proved that the insulation state of the pressurized phase is not good, and the defect position needs to be checked, if the voltage withstand test is performed by switching each set of stator windings 106, the change of the total current of the loop is not large, which proves that the insulation state of the stator windings 106 is good, and the stator windings can pass the dc voltage withstand test. Although the dc withstand voltage test method provided in this embodiment cannot accurately measure the insulation current of the stator winding 106, the insulation state of the stator winding 106 can be determined according to the change of the total current of the loop, so as to effectively solve the problem of error in the existing test and increase the basis for determining the insulation state of the generator. Since the insulation resistance and the dc withstand voltage are the same in principle, the insulation resistance result can be directly replaced by the dc withstand voltage result (the insulation resistance result described in this embodiment is not specific data, but how much the insulation state of the insulation resistance is). The advantages of using the above test are: the generator with the water collecting pipe 108 in dead grounding has the advantages that when the unit is in minor repair (the rotor is not pumped), regulations (DL/T-1768 and 2017) stipulate, insulation resistance is measured and can be replaced by the test method, when the unit is in major repair, a direct-current withstand voltage test can be carried out according to the requirements of the regulations, an alternating-current withstand voltage test can be carried out after the unit passes through, and adverse consequences caused by the direct alternating-current withstand voltage test are avoided.
In addition, the embodiment also provides a method for detecting the insulation state of the generator, which is suitable for the case that the water collection pipe 108 is in dead ground and water flows, the method for testing the direct-current withstand voltage after the water collection pipe 108 of the generator is fixedly grounded is firstly carried out, and the alternating-current withstand voltage test is carried out after the method for testing the direct-current withstand voltage after the water collection pipe 108 of the generator is fixedly grounded passes through.
The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. A DC withstand voltage test method after a generator water collecting pipe is fixedly grounded is characterized in that,
which comprises adopting a direct current high voltage generator special for a water-cooled generator to carry out a water-carrying direct current withstand voltage test on the generator with a catchment pipe dead grounded,
controlling the direct-current high-voltage generator special for the water-cooled generator to provide direct-current high voltage for the direct-current withstand voltage test, performing a grouping test on a stator winding of the generator, controlling the direct-current high voltage provided by the direct-current high-voltage generator special for the water-cooled generator to gradually increase to required test voltage during each group of tests, and monitoring and reading the total current of a loop through an ammeter connected in series with the high-voltage side in the boosting process;
if the difference value of the total current of the loops of each group does not exceed the set range value, the direct current withstand voltage test is passed, and the alternating current withstand voltage test can be carried out; or,
and if the difference value of the total current of the loops of each group exceeds the set range value, stopping pressurizing and searching the defect part.
2. The direct-current withstand voltage test method after the generator water collecting pipe is fixedly grounded as claimed in claim 1, characterized in that the ammeter is a pointer ammeter.
3. The direct-current withstand voltage test method after the generator water collecting pipe is fixedly grounded according to claim 1 or 2, characterized in that the ammeter is a milliammeter.
4. The method for testing direct-current withstand voltage after the generator collector tube is grounded fixedly according to claim 1, wherein the set range value is such that the current ratio difference between three phases does not exceed 50%.
5. The method for testing the direct-current withstand voltage of the generator collector pipe after being fixedly grounded according to claim 1, wherein the test voltage is increased in stages by 0.5Un per stage, stays for 1min per stage, monitors the change degree of current, and then performs the next stage of voltage increase until the voltage is reduced after the test is completed.
6. The method for testing the direct-current withstand voltage of the generator collector pipe after being fixedly grounded according to claim 5, wherein the test voltage is 2.5Un at most.
7. The direct-current withstand voltage test method after the generator water collecting pipe is fixedly grounded according to claim 5, characterized in that the voltage is increased at a voltage increasing speed of 1-3Kv/s in the voltage increasing process, and the current of the ammeter does not exceed the maximum charging current of the direct-current high-voltage generator special for the water-cooled generator during the voltage increasing.
8. The DC withstand voltage test method after the generator catchment pipe is fixedly grounded according to claim 1, characterized in that the DC high voltage generator special for the water-cooled generator comprises a case, a pressure doubling cylinder, an ammeter, a current limiting resistor, an overvoltage protection device, a discharge rod and a grounding wire group, the generator comprises a stator winding, an equivalent water resistor, a catchment pipe and a rotor winding, the case receives a power supply and controls the pressure doubling cylinder to generate a set high voltage, the pressure doubling cylinder feeds a current value back to the case through a measuring terminal, a high voltage output end of the pressure doubling cylinder is electrically connected with a pressurizing phase in the stator winding, the ammeter, the current limiting resistor and the overvoltage protection device are connected in series between the pressure doubling cylinder and the stator winding, a catchment pipe interface end of the case is simultaneously electrically connected with the catchment pipe and the overvoltage protection device, the water collecting pipe is in dead grounding, the rotor winding is in grounding, and the grounding end of the case, the grounding end of the pressure doubling cylinder, the two-phase non-pressurized phase in the stator winding and the discharge rod are all electrically connected with the grounding wire group.
9. A method for detecting the insulation state of a generator, which is suitable for the condition that a water collecting pipe is in dead ground and is filled with water, is characterized in that the direct-current withstand voltage test method of any one of claims 1 to 8 after the generator water collecting pipe is fixedly grounded is firstly carried out, and the alternating-current withstand voltage test is carried out after the direct-current withstand voltage test method of the generator water collecting pipe is passed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111159327.XA CN113820598A (en) | 2021-09-30 | 2021-09-30 | Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111159327.XA CN113820598A (en) | 2021-09-30 | 2021-09-30 | Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113820598A true CN113820598A (en) | 2021-12-21 |
Family
ID=78919822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111159327.XA Pending CN113820598A (en) | 2021-09-30 | 2021-09-30 | Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113820598A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102540035A (en) * | 2010-12-28 | 2012-07-04 | 苏州华电电气股份有限公司 | Comprehensive direct-current high-voltage test device for internal water cooling generator |
| CN105785247A (en) * | 2016-04-29 | 2016-07-20 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Circuit-breaker alternating current and direct current mixing voltage withstanding wiring loop used for alternating current filter and test method thereof |
| CN205958708U (en) * | 2016-05-18 | 2017-02-15 | 中国长江电力股份有限公司 | Alternate water -cooled generator direct current test instrument that has water path connection |
| DE102015115447A1 (en) * | 2015-09-14 | 2017-03-16 | Friedrich-Alexander-Universität Erlangen - Nürnberg | Measuring method for the determination of iron losses |
| CN108872857A (en) * | 2018-07-26 | 2018-11-23 | 中国大唐集团科学技术研究院有限公司西北分公司 | A kind of generator scene mixing pressure test device and method |
| CN111999645A (en) * | 2020-09-23 | 2020-11-27 | 赵旭 | Portable generator stator water polarization potential compensation device |
| CN113075509A (en) * | 2021-03-30 | 2021-07-06 | 中国大唐集团科学技术研究院有限公司中南电力试验研究院 | Online monitoring device and monitoring method for insulation of water and electricity connector of bar of internal water cooling generator |
| CN113203926A (en) * | 2021-04-29 | 2021-08-03 | 中国长江电力股份有限公司 | Direct-current withstand voltage tester and method for inter-phase lap joint water conduit of water-cooled generator |
-
2021
- 2021-09-30 CN CN202111159327.XA patent/CN113820598A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102540035A (en) * | 2010-12-28 | 2012-07-04 | 苏州华电电气股份有限公司 | Comprehensive direct-current high-voltage test device for internal water cooling generator |
| DE102015115447A1 (en) * | 2015-09-14 | 2017-03-16 | Friedrich-Alexander-Universität Erlangen - Nürnberg | Measuring method for the determination of iron losses |
| CN105785247A (en) * | 2016-04-29 | 2016-07-20 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | Circuit-breaker alternating current and direct current mixing voltage withstanding wiring loop used for alternating current filter and test method thereof |
| CN205958708U (en) * | 2016-05-18 | 2017-02-15 | 中国长江电力股份有限公司 | Alternate water -cooled generator direct current test instrument that has water path connection |
| CN108872857A (en) * | 2018-07-26 | 2018-11-23 | 中国大唐集团科学技术研究院有限公司西北分公司 | A kind of generator scene mixing pressure test device and method |
| CN111999645A (en) * | 2020-09-23 | 2020-11-27 | 赵旭 | Portable generator stator water polarization potential compensation device |
| CN113075509A (en) * | 2021-03-30 | 2021-07-06 | 中国大唐集团科学技术研究院有限公司中南电力试验研究院 | Online monitoring device and monitoring method for insulation of water and electricity connector of bar of internal water cooling generator |
| CN113203926A (en) * | 2021-04-29 | 2021-08-03 | 中国长江电力股份有限公司 | Direct-current withstand voltage tester and method for inter-phase lap joint water conduit of water-cooled generator |
Non-Patent Citations (5)
| Title |
|---|
| 唐芳轩, 许燕霞: "大型水内冷汽轮发电机定子绕组的耐压试验", 电力建设, no. 02, pages 13 - 14 * |
| 国家能源局: "电力设备预防性试验规程", pages: 11 - 12 * |
| 姚卫东;周剑峰;: "采用低压屏蔽法进行双水内冷发电机的直流耐压试验", 青海电力, no. 02 * |
| 李浩良;潘剑南;: "引水管缺陷引起发电机泄漏电流过大缺陷诊断方法", 大电机技术, no. 04, pages 52 - 57 * |
| 葛占雨;: "大型水内冷发电机直流耐压试验和泄漏电流测试技术探讨", 电力建设, no. 07 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Stone et al. | Stator winding monitoring | |
| Liu et al. | A study of the sweep frequency impedance method and its application in the detection of internal winding short circuit faults in power transformers | |
| KR100823724B1 (en) | Apparatus and method for detecting stator winding groundwall insulation condition of inverter-fed AC motor | |
| Verginadis et al. | Determination of the insulation condition in synchronous generators: Industrial methods and a case study | |
| Harrold et al. | Radio frequency sensing of incipient arcing faults within large turbine generators | |
| Rux et al. | Assessing the condition of hydrogenerator stator winding insulation using the ramped high direct-voltage test method | |
| Verginadis et al. | Diagnosis of stator faults in synchronous generators: Short review and practical case | |
| RU2744464C1 (en) | Method for determining hazardous areas in the insulation of three-core three-phase cable power lines | |
| CN211478525U (en) | System for diagnosing insulation defect at end part of stator wire rod of generator | |
| CN113820598A (en) | Direct-current voltage withstand test method after generator water collecting pipe is fixedly grounded | |
| Van Breen et al. | Standardization of on-line VHF PD measurements on turbo generators | |
| JPH0727812A (en) | Insulation diagnosing device | |
| Yang et al. | Research of sweep frequency impedance to determine transformer winding deformation after short-circuit impact | |
| Drif et al. | The use of the stator instantaneous complex apparent impedance signature analysis for discriminating stator winding faults and supply voltage unbalance in three-phase induction motors | |
| Stone et al. | Advances in interpreting partial discharge test results from motor and generator stator windings | |
| Sano et al. | Experimental investigation on FRA diagnosis of transformer faults | |
| CN114527358A (en) | Practical application of coal mine power supply cable in alternating current/direct current withstand voltage in electrical test | |
| Lumba et al. | Online and Offline Partial Discharge Measurement in Rotating Machines using Transient Earth Voltage Sensors | |
| KR102099070B1 (en) | Apparatus for analyzing moisture absorption of power generator stator winding and method thereof | |
| CN114252742A (en) | GIS equipment dynamic insulation performance test method and system | |
| CN113391129A (en) | Method for testing medium loss factor of valve side sleeve and winding of converter transformer | |
| CN113009286A (en) | Method for diagnosing insulation defect at end part of stator wire rod of generator | |
| Stone et al. | The testing tools | |
| Zhang et al. | Online monitoring of capacitance and dissipation factor of motor stator winding insulation during accelerated life testing | |
| JP3808914B2 (en) | Non-destructive insulation test method and equipment for small electrical machines |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |