CN115825809A - Transformer core multipoint ground fault simulation device and evaluation method - Google Patents
Transformer core multipoint ground fault simulation device and evaluation method Download PDFInfo
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Abstract
The invention provides a device and a method for simulating multipoint ground faults of a transformer core, belonging to the technical field of multipoint ground fault simulation of transformer cores; the problem that multipoint ground faults at different positions of the transformer core cannot be accurately simulated is solved, and the state quantity change conditions of the transformer core such as ground current, temperature rise in oil, content of dissolved gas in the oil and the like under different multipoint ground faults are researched based on the proposed simulation device; the transformer comprises a transformer shell, an iron core single-point grounding point is led out from an iron yoke on the transformer, the transformer shell is also connected with an oil filtering module through a pipeline, and the transformer shell is connected with an oil chromatography detection module through an oil taking port; the surface of the upper iron yoke and the surface of the lower iron yoke of the transformer are respectively provided with a fault simulation device, two sides of the fault simulation device are respectively provided with a temperature detection module, and the fault simulation device is connected into the switch control module through a lead; the invention is applied to the transformer.
Description
Technical Field
The invention provides a device and a method for simulating multipoint ground faults of a transformer core, and belongs to the technical field of multipoint ground fault simulation of transformer cores.
Background
The transformer is one of the most important devices of the power system, and the operation state of the transformer is directly related to the safety and stability of the power system. The transformer iron core must be grounded in a single point or otherwise generates a suspension potential, once the transformer iron core is grounded in multiple points, a loop is formed, and under the main leakage electromagnetic induction, a loop current is generated, so that the transformer is easily damaged during operation, a power failure event is caused, and great economic loss is caused.
When multipoint ground faults occur at different positions of a transformer core, circulation paths are different, circulation magnitude generated by main leakage electromagnetic induction is also different, and the larger the circulation is, the larger the generated heat is, and the larger the damage to the transformer is. At present, research on damage degree of iron core multipoint earthing at different positions to a transformer does not exist, and a transformer iron core multipoint earthing fault simulation device and an evaluation method are absent.
Chinese patent CN106771816B discloses an iron core loss test platform and a test method under a rolled iron core multipoint ground fault, ground wires are led out from 30% and 70% silicon steel sheet levels of an iron core, and the iron core loss is monitored by a monitoring power analyzer, so that relevance research between the multipoint ground of the transformer iron core and the iron core loss is realized. However, the direct extraction of the single silicon steel sheet is easy to cause short circuit between the silicon steel sheets, and the device does not take more consideration in this respect. The temperature rise of transformer oil, the change of dissolved gas in the oil and the grounding current caused by multipoint grounding are not researched too much.
Chinese patent CN106526394B discloses a system and a method for testing local temperature rise of an iron core under a short circuit fault between wound iron core sheets, wherein 30 silicon steel sheets on a transformer core are simultaneously subjected to the short circuit fault between the sheets through computer control, and a temperature probe is arranged in a short circuit area between the sheets, so that the relevance between the short circuit fault between the silicon steel sheets of the iron core and the local temperature rise of the iron core is researched. However, the device considers that the short circuit between the iron core silicon steel sheets is different from the iron core multipoint earthing of the invention, and only considers the temperature rise on one hand, and does not probe the temperature rise of the transformer oil, the change of dissolved gas in the oil and the earthing current caused by the multipoint earthing, and can not evaluate the transformer state comprehensively.
Disclosure of Invention
The invention provides a multipoint grounding fault simulation device and an evaluation method of a transformer core, aiming at solving the problem that multipoint grounding faults at different positions of the transformer core cannot be accurately simulated, and the multipoint grounding fault simulation device and the evaluation method are used for researching the relevance of multipoint grounding and grounding current, oil temperature and dissolved gas in oil at different positions of the transformer core and realizing the multipoint grounding state evaluation at different positions of the transformer core.
In order to solve the technical problems, the invention adopts the technical scheme that: a multipoint grounding fault simulation device for a transformer core comprises a transformer shell, wherein an upper transformer yoke, a lower transformer yoke, a high-voltage coil, a low-voltage coil and transformer oil are arranged in the transformer shell, a single-point grounding point of the core is led out from the upper transformer yoke, the high-voltage coil and the low-voltage coil are respectively fixed on a left core column and a right core column in the transformer shell, the transformer shell is further connected with an oil filtering module through a pipeline, an oil taking port is further arranged on the transformer shell, and the oil taking port is connected with an oil chromatography detection module through a pipeline;
an upper yoke fault simulation device is mounted on the surface of an upper yoke of the transformer, a lower yoke fault simulation device is mounted on the surface of a lower yoke of the transformer, temperature detection modules are respectively arranged on two sides of the upper yoke fault simulation device and the lower yoke fault simulation device, the upper yoke fault simulation device and the lower yoke fault simulation device are connected through wires and then are connected to a switch control module, and the switch control module is connected with a power supply module;
the iron core single-point grounding point is connected with the current detection module and the data transmission module through a lead and then is connected to the background computer.
The upper yoke fault simulation device and the lower yoke fault simulation device have the same structure and respectively comprise 5 sets of fault generation devices, wherein the 5 sets of fault generation devices are respectively distributed on the first-stage silicon steel sheet position, the 30% silicon steel sheet stage position, the 50% silicon steel sheet stage position, the 80% silicon steel sheet stage position and the 100% silicon steel sheet stage position of the upper yoke and the lower yoke of the transformer;
each set of fault generating device comprises 1 group of insulating guide plates, 1 single silicon steel sheet, 1 wood plate, 1 copper sheet, 1 spring, 1 pair of electronic traction electromagnets and 1 pair of traction ropes, wherein the insulating guide plates of 5 sets of fault generating devices of the upper iron yoke fault simulating device and the lower iron yoke fault simulating device are respectively fixed on the surfaces of the silicon steel sheets of the corresponding stages of the upper iron yoke and the lower iron yoke of the transformer, one end of the single silicon steel sheet is inserted in the middle of the insulating guide plates, the other end of the single silicon steel sheet is fixed on the wood plate with the copper sheet attached to the surface and communicated with the copper sheet, the copper sheet is connected with the ground through a lead, the other surface of the wood plate is connected with the spring, the other end of the spring is fixed at the top of the fault generating device, the 1 pair of electronic traction electromagnets are distributed at two sides of the spring and fixed at the top of the fault generating device, and the 1 pair of electronic traction electromagnets are connected with two ends of the wood plate through the traction ropes, so that the spring is in a compressed state;
the power input of the electronic traction electromagnet serves as the control end of the fault generating device, the corresponding control ends of the fault generating device installed on the upper iron yoke of the 5 sets of transformers and the fault generating device installed on the lower iron yoke of the 5 sets of transformers are connected into the switch control module and connected with the power module through 10 first normally closed electromagnetic relays, and 10 control buttons are distributed on the surface of the switch control module and correspondingly control the on-off of the 10 first normally closed electromagnetic relays.
The current detection module comprises a current sensor, an overcurrent protection unit, a first controller and a first data transmission unit, wherein a lead of a single-point grounding point of the iron core is connected with a primary winding of the current sensor, the other end of the primary winding of the current sensor is connected with the overcurrent protection unit in series and then grounded, a secondary winding of the current sensor is connected with the first controller, and the first controller is communicated with a background computer through the first data transmission unit.
The temperature detection module comprises 20 temperature sensors, a second controller and a second data transmission unit, wherein the 20 temperature sensors, the second controller and the second data transmission unit are sequentially distributed on two sides of the surface of the silicon steel sheet at the corresponding stage positions of the upper iron yoke and the lower iron yoke of the transformer, the temperature sensors transmit temperature monitoring data of the upper iron yoke and the lower iron yoke of the transformer to the second controller, and the second controller is communicated with the background computer through the second data transmission unit.
The oil chromatogram detection module comprises an oil chromatogram gas chromatograph, a third controller and a third control unit, the oil chromatogram gas chromatograph is connected with the oil taking port and sends a detection result to the third controller, and the third controller transmits the data to the background computer through the third data transmission unit after processing the data.
The overcurrent protection unit comprises a second normally-closed electromagnetic relay and a current-limiting impedance which are connected in parallel.
A multipoint earth fault evaluation method of a transformer core adopts a multipoint earth fault simulation device of the transformer core, and comprises the following steps:
s1: regulating the load of the high-voltage side winding and the low-voltage side winding of the transformer to enable the transformer to be in a full-load running state;
s2: when the transformer is in normal single-point grounding operation, the initial value I of the iron core single-point grounding current is recorded by the current sensor 1 And transmits the measured values (T) to the first controller, and the monitored values (T) of 20 temperature sensors are obtained 1 ,T 2 ,……,T 20 ) Transmitted to the second controller according to the formula
Calculating to obtain the initial single-point grounding temperatures of the iron cores on the surfaces of the silicon steel sheets at the positions of the upper iron yoke and the lower iron yoke of the transformer
）；
Wherein T is 1 、T 2 Respectively monitoring values T of temperature sensors at two sides of the first-stage silicon steel sheet position of the iron yoke on the transformer 3 、T 4 Respectively monitoring values T of temperature sensors at two sides of 30% silicon steel sheet position of iron yoke on transformer 5 、T 6 Respectively monitoring values T of temperature sensors at two sides of 50% silicon steel sheet position of iron yoke on transformer 7 、T 8 Respectively monitoring values T of temperature sensors at two sides of 80% silicon steel sheet position of iron yoke on transformer 9 、T 10 Respectively monitoring values T of temperature sensors at two sides of 100% silicon steel sheet position of iron yoke on transformer 11 、T 12 Respectively monitoring values T of temperature sensors at two sides of the first-stage silicon steel sheet position of the lower iron yoke of the transformer 13 、T 14 Respectively monitoring values T of temperature sensors at two sides of a 30% silicon steel sheet position of an iron yoke under the transformer 15 、T 16 Respectively monitoring values T of temperature sensors at two sides of 50% silicon steel sheet position of lower iron yoke of transformer 17 、T 18 Respectively monitoring values T of temperature sensors at two sides of 80% silicon steel sheet position of lower iron yoke of transformer 19 、T 20 Respectively monitoring values of temperature sensors at two sides of a 100% silicon steel sheet position of the lower iron yoke of the transformer,
、
respectively showing the initial temperatures of single-point grounding of iron cores on the surfaces of the silicon steel sheets at the first-stage silicon steel sheet positions of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively representing the initial temperature of single-point grounding of the iron core on the surface of the silicon steel sheet at the 30% silicon steel sheet level position of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively showing the initial temperature of single-point grounding of the iron core on the surface of the silicon steel sheet at the 50% silicon steel sheet level position of the upper iron yoke and the lower iron yoke of the transformer,
、
iron core with silicon steel sheet surface at 80% silicon steel sheet level position for respectively representing upper iron yoke and lower iron yoke of transformerThe initial temperature is set at a single point of ground,
、
respectively representing the initial temperature of single-point grounding of iron cores on the surfaces of silicon steel sheets at the 100% silicon steel sheet level positions of an upper iron yoke and a lower iron yoke of the transformer;
detecting the content of each gas component in the iron core single-point grounding initial oil by an oil chromatography gas chromatograph: (
) And transmitted to the third controller;
s3: setting different transformer iron core multipoint grounding faults through a control button of a control switch control module, and recording iron core multipoint grounding current value I through a current sensor 2 And transmitting the characteristic quantity A to a first controller, and processing the characteristic quantity A by the first controller to obtain a characteristic quantity A, wherein the expression of A is as follows:
recording the multipoint earthing temperature of the iron core on the surface of the silicon steel sheet at the multi-stage silicon steel sheet positions of the upper iron yoke and the lower iron yoke of the transformer monitored by 20 temperature sensors (
) And transmitting the characteristic quantity B to a second controller, and processing the characteristic quantity B by the second controller to obtain a characteristic quantity B, wherein the expression of B is as follows:
in the above formula: t is a unit of * The temperature of the iron core on the surface of the silicon steel sheet during multipoint earth fault is shown, and T shows the initial single-point earth temperature of the iron core on the surface of the silicon steel sheet;
monitoring the content of each gas component in the iron core multipoint grounding oil by an oil chromatography gas chromatograph (
) And transmitting the characteristic quantity C to a third controller, and obtaining a characteristic quantity C according to a three-ratio method principle, wherein the expression of C is as follows:
s4: sending the characteristic quantity A, B, C to a background computer through a data transmission module, and calculating to obtain a fault coefficient D, wherein
；
S5: and (5) after the transformer oil is filtered by the oil filtering module, replacing the multipoint ground fault position, and repeating the steps S1-S4 to obtain the defect severity of the multipoint-connection underground transformer at different positions of the transformer core.
And judging the defect grade of multipoint grounding at different positions of the transformer by using a fault coefficient D, wherein the judging formula is as follows:
compared with the prior art, the invention has the beneficial effects that: the device and the method for simulating the multipoint grounding fault of the transformer core can accurately simulate the state quantity change conditions of the transformer core such as grounding current, temperature rise in oil, content of dissolved gas in oil and the like under different multipoint grounding faults, realize the comprehensive evaluation of the running state of the transformer core under different multipoint grounding faults, and have important guiding significance on the multipoint grounding field fault diagnosis and treatment of the transformer core
Drawings
The invention is further described below with reference to the accompanying drawings:
FIG. 1 is a schematic view of the overall structure of the apparatus of the present invention;
FIG. 2 is a schematic structural diagram of an upper yoke fault simulation device and a lower yoke fault simulation device of a transformer according to the present invention;
FIG. 3 is a schematic structural diagram of a switch control module according to the present invention;
FIG. 4 is a schematic structural diagram of a control button on the switch control module according to the present invention;
FIG. 5 is a schematic structural diagram of a current detection module according to the present invention;
FIG. 6 is a schematic structural diagram of a temperature detecting module according to the present invention;
FIG. 7 is a schematic structural diagram of an oil chromatography detection module according to the present invention;
in the figure: the device comprises a background computer 1, a transformer shell 2, a transformer upper yoke 3, a transformer lower yoke 4, a high-voltage coil 5, a low-voltage coil 6, transformer oil 7, an upper yoke fault simulation device 8, a lower yoke fault simulation device 9, a data transmission module 10, a current detection module 11, a temperature detection module 12, an oil chromatography detection module 13, an oil taking port 14, an oil filtering module 15, a switch control module 16, a power supply module 17 and an iron core single-point grounding point 18, wherein the transformer shell 2 is a transformer shell;
20 is an insulating guide plate, 21 is a single silicon steel sheet, 22 is a wood plate, 23 is a copper sheet, 24 is a spring, 25 is an electronic traction electromagnet, 26 is a traction rope, 27 is a first normally closed electromagnetic relay, 28 is a control button, 29 is a current sensor, 30 is an overcurrent protection unit, 31 is a first controller, 32 is a first data transmission unit, 33 is a second normally closed electromagnetic relay, 34 is a current limiting impedance, 35 is a temperature sensor, 36 is a second controller, 37 is a second data transmission unit, 38 is an oil chromatography gas chromatograph, 39 is a third controller, and 40 is a third data transmission unit.
Detailed Description
The invention provides a multipoint grounding fault simulation device for a transformer iron core, which is structurally shown in figure 1 and comprises a background computer 1, a transformer shell 2, a transformer upper iron yoke 3, a transformer lower iron yoke 4, a high-voltage coil 5, a low-voltage coil 6, transformer oil 7, an upper iron yoke fault simulation device 8, a lower iron yoke fault simulation device 9, a data transmission module 10, a current detection module 11, a temperature detection module 12, an oil chromatography detection module 13, an oil taking port 14, an oil filtering module 15, a switch control module 16 and a power supply module 17, wherein a single-point iron core grounding point 18 is led out from the middle of the transformer upper iron yoke 3, one end of the switch control module 16 is connected with the upper iron fault simulation device 8 and the lower iron yoke fault simulation device 9, the other end of the switch control module is connected with the power supply module 17, 2 fault simulation devices are arranged on the surfaces of the transformer upper iron yoke 3 and the transformer lower iron yoke 4, the oil taking port 14 is connected with the oil chromatography detection module 13, the temperature detection module 12 is distributed on two sides of the upper iron yoke fault simulation device 8 and the lower iron yoke fault simulation device 9, and the oil filtering module 15 is carried out after the fault simulation device is finished each time.
The upper yoke fault simulation device 8 and the lower yoke fault simulation device 9 provided by the invention have the structure shown in fig. 2, the upper yoke fault simulation device 8 is divided into 5 sets of fault generation devices, the lower yoke fault simulation device 9 is divided into 5 sets of fault generation devices, and the 5 sets of fault generation devices comprise 5 groups of insulating guide plates 20, 5 single silicon steel sheets 21, 5 wood plates 22, 5 copper sheets 23, 5 springs 24, 5 pairs of electronic traction electromagnets 25 and 5 pairs of traction ropes 26. Because the upper iron yoke and the lower iron yoke respectively have 30-level silicon steel sheets, the first set of fault generating devices are distributed at the first-level silicon steel sheet positions (upper 1 and lower 1) of the upper iron yoke and the lower iron yoke, the second set of fault generating devices are distributed at the 30% level positions (upper 2 and lower 2) of the upper iron yoke and the lower iron yoke, namely the 9 th-level silicon steel sheet positions, the third set of fault generating devices are distributed at the 50% level positions (upper 3 and lower 3) of the upper iron yoke and the lower iron yoke, the fourth set of fault generating devices are distributed at the 80% level positions (upper 4 and lower 4) of the upper iron yoke and the lower iron yoke, and the fifth set of fault generating devices are distributed at the 30 th-level silicon steel sheet positions (upper 5 and lower 5) of the upper iron yoke and the lower iron yoke.
And a group of insulating guide plates 20 of each set of fault generating device is fixed on the surfaces of the silicon steel sheets in corresponding grades and used for ensuring the silicon steel sheets in corresponding grades to be accurately grounded and avoiding short circuit among generating sheets. One end of a single silicon steel sheet 21 is inserted in the middle of the insulating guide plate 20, the other end of the single silicon steel sheet is fixed on a wood plate 22 with a copper sheet 23 attached to the surface and communicated with the copper sheet 23, the copper sheet 23 is connected with the ground through a conducting wire, the other side of the wood plate 22 is connected with a spring 24, the other end of the spring 24 is fixed at the top of the fault generating device, 1 pair of electronic type traction electromagnets 25 are distributed on two sides of the spring 24 and fixed at the top of the fault generating device, and 1 pair of electronic type traction electromagnets 25 are connected with two ends of the wood plate 22 through a traction rope 26 to enable the spring 24 to be in a compressed state.
The structure of the switch control module provided by the invention is shown in fig. 3, fig. 4 is a schematic structural diagram of a control button on the switch control module, a power supply input of an electronic traction electromagnet 25 is used as a control end of a fault generating device, corresponding control ends of 5 sets of upper iron yoke fault generating devices and 5 sets of lower iron yoke fault generating devices are connected to the switch control module 16 and are connected with a power supply module 17 through 10 first normally-closed electromagnetic relays 27 (including upper 1, upper 2, upper 3, upper 4, upper 5, lower 1, lower 2, lower 3, lower 4 and lower 5), and the power supply module 17 is a power supply with 220v voltage and is used for supplying power to the switch control module 16. The surface of the switch control module 16 is distributed with 10 control buttons 28 (including upper 1, upper 2, upper 3, upper 4, upper 5, lower 1, lower 2, lower 3, lower 4 and lower 5) for correspondingly controlling the on-off of 10 first normally closed electromagnetic relays 27 in the switch control module. Under the condition that the electronic type traction electromagnet 25 is not power off, the spring 24 is in a compressed state, the silicon steel sheet below the wood plate 22 is inserted into 1/2 depth of the insulating guide plate 20, when the control button 28 is pressed, the corresponding electromagnetic relay is disconnected, under the condition that the corresponding electronic type traction electromagnet 25 is power off, the spring 24 is restored from the compressed state, one end of the silicon steel sheet inserted into the insulating guide plate 20 is contacted with a transformer iron yoke, and therefore multipoint grounding of the transformer iron core is achieved, and the spring 24 has a certain buffering effect when the silicon steel sheet is contacted with an upper iron yoke or a lower iron yoke.
The structure of the current detection module provided by the present invention is shown in fig. 5, and the current detection module 11 specifically includes a current sensor 29, an overcurrent protection unit 30, a first controller 31, and a first data transmission unit 32, where the overcurrent protection unit 30 is formed by connecting a second normally closed electromagnetic relay 33 and a current limiting impedance 34 in parallel. The lead of the core single-point grounding point 18 is connected with the primary winding of the current sensor 29, the other end of the primary winding of the current sensor 29 is connected with the overcurrent protection unit 30 in series and then grounded, and the secondary winding of the current sensor 29 is connected with the first controller 31. The monitoring data of the current sensor 29 is sent to the first controller 31, processed by the first controller 31, and then transmitted to the background computer 1 through the first data transmission unit 32. When the first controller 31 detects that the value of the current sensor 29 is greater than 20A in the core multipoint ground fault simulation process, the second normally-closed electromagnetic relay 33 is controlled to be opened, and the current-limiting impedance 34 is connected in series to a loop for overcurrent protection, wherein the current-limiting impedance 34 selects 100 omega.
As shown in fig. 6, the structure of the temperature detection module provided by the present invention is that the temperature detection module 12 specifically includes 20 temperature sensors 35, a second controller 36, and a second data transmission unit 37, where the 20 temperature sensors 35 are sequentially distributed on two sides of the upper yoke fault simulation device 8 and the lower yoke fault simulation device 9, that is, at the surface positions of the upper 1, the upper 2, the upper 3, the upper 4, the upper 5, the lower 1, the lower 2, the lower 3, the lower 4, and the lower 5-stage yoke silicon steel sheet, the temperature sensors 35 transmit temperature monitoring data to the second controller 36, and the characteristic quantity B is generated through data analysis and processing, and then the temperature monitoring data is transmitted to the background computer 1 through the second data transmission module 37.
The structure of the oil chromatography detection module provided by the invention is shown in fig. 7, and the oil chromatography detection module 13 comprises an oil chromatography gas chromatograph 38, a third controller 39 and a third data transmission unit 40. The oil chromatograph 38 is connected to the oil intake 14 of the transformer, and can be manually controlled to perform sampling analysis, and the detection result is sent to the third controller 39, processed by the third controller 39, and then transmitted to the background computer 1 through the third data transmission unit 40.
The invention also provides a state evaluation method under different multipoint ground faults of the transformer core, which is realized by adopting the structure of the transformer core multipoint ground fault simulation device and comprises the following specific steps:
1) And regulating the load of the high-voltage side winding and the low-voltage side winding of the transformer to ensure that the transformer is in a full-load running state.
2) Wherein the transformer core operates normally in single point grounding when the control button 28 of the switch control module 16 is not operated. When the transformer is in normal operation of single-point grounding, the initial value I of the iron core single-point grounding current is recorded by the current sensor 29 1 And transmitted to the first controller 31; monitoring 20 temperature sensors by (T 1 ,T 2, …,T 20 ) Transmitting to the second controller 36, and obtaining the positions of 1, upper 2, upper 3, upper 4, upper 5, lower 1, lower 2, lower 3, lower 4, and lower 5 on the iron yoke silicon steel sheet according to the formula 1Initial temperature of single point grounding of iron core on surface of silicon steel sheet (
）；
Wherein T is 1 And T 2 The monitoring value T of the temperature sensors at two sides of the 1 position on the iron yoke silicon steel sheet 3 And T 4 The monitoring values of temperature sensors at two sides of the 2 position on the iron yoke silicon steel sheet, T 19 And T 20 The monitoring values of the temperature sensors at two sides of the lower 5 position of the iron yoke silicon steel sheet are obtained.
Monitoring the content of each gas component in the core single-point grounding initial oil by an oil chromatograph gas chromatograph 38
) And transmitted to the third controller 39.
3) By controlling the control button 28 of the switch control module 16, the following transformer core multipoint grounding conditions can be simulated:
(1) the same side iron yoke and the same silicon steel sheet level are subjected to multipoint grounding: pressing a button 3 of a switch control module 16, opening the first normally-closed electromagnetic relay 3, and simulating the generation of multipoint grounding in the stage of 50% silicon steel sheets of an upper iron yoke;
(2) the same side iron yoke generates multipoint grounding in different silicon steel sheet grades: sequentially pressing down the upper 1, the upper 2, the upper 4 and the upper 5 of the buttons of the switch control module 16, and sequentially opening the upper 1, the upper 2, the upper 4 and the upper 5 of the first normally closed electromagnetic relay to respectively simulate the positions of a first-stage silicon steel sheet of an upper iron yoke, a 30% -stage silicon steel sheet of the upper iron yoke, an 80% -stage silicon steel sheet of the upper iron yoke and a 100% -stage silicon steel sheet to generate multipoint grounding;
(3) the iron yokes on different sides are grounded at multiple points in the same silicon steel sheet stage: the lower button 3 of the switch control module 16 is pressed, the lower first normally-closed electromagnetic relay 3 is opened, and multipoint grounding is generated by simulating the series of 50% silicon steel sheets of the lower iron yoke;
(4) multipoint grounding occurs at different grades of silicon steel sheets of different side iron yokes: the lower buttons 1, the lower buttons 2, the lower buttons 4 and the lower buttons 5 of the switch control module 16 are pressed in sequence, the lower buttons 1, the lower buttons 2, the lower buttons 4 and the lower buttons 5 of the first normally closed electromagnetic relay are opened in sequence, and multipoint grounding is generated at positions of the first-stage silicon steel sheet of the lower iron yoke, the 30% -stage silicon steel sheet of the lower iron yoke, the 80% -stage silicon steel sheet of the lower iron yoke and the 100% -stage silicon steel sheet of the lower iron yoke respectively.
The core multipoint grounding current value I is recorded by the current sensor 29 2 And transmitted to the first controller 31, and the characteristic quantity a obtained by the analysis and processing of the first controller 31 is as shown in formula 2;
recording 20 temperature sensors 35 to obtain the multipoint grounding temperatures of the surface iron cores of the silicon steel sheets at the upper 1, upper 2, upper 3, upper 4, upper 5, lower 1, lower 2, lower 3, lower 4 and lower 5 positions (
) And transmits to the second controller 36, and the characteristic quantity B obtained by processing by the second controller 36 is as shown in formula 3;
the content of each gas component in the iron core multipoint grounding oil is monitored by an oil chromatography gas chromatograph 38
) And transmitted to the third controller 39, and the characteristic quantity C obtained according to the principle of the three-ratio method is as shown in formula 4;
4) The characteristic quantity A, B, C is sent to the background computer 1 through the data transmission module 10, and the background computer 1 obtains a fault coefficient D according to a formula 5;
judging the defect grade of multipoint grounding of different positions of the transformer by using a fault coefficient D, wherein the expression of a judgment formula 6 is as follows:
5) After the transformer oil 7 is filtered by the oil filtering module 15, the multipoint grounding fault position is changed, and the steps 1), 2), 3) and 4) are repeated to obtain the defect severity of the multipoint-connection underground transformer at different positions of the transformer core.
It should be noted that, regarding the specific structure of the present invention, the connection relationship between the modules adopted in the present invention is determined and can be realized, except for the specific description in the embodiment, the specific connection relationship can bring the corresponding technical effect, and the technical problem proposed by the present invention is solved on the premise of not depending on the execution of the corresponding software program.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (8)
1. A transformer core multipoint ground fault simulation device is characterized in that: the transformer comprises a transformer shell, wherein a transformer upper iron yoke, a transformer lower iron yoke, a high-voltage coil, a low-voltage coil and transformer oil are arranged in the transformer shell, an iron core single-point grounding point is led out from the transformer upper iron yoke, the high-voltage coil and the low-voltage coil are respectively fixed on a left core column and a right core column in the transformer shell, the transformer shell is also connected with an oil filtering module through a pipeline, an oil taking port is also arranged on the transformer shell, and the oil taking port is connected with an oil chromatography detection module through a pipeline;
an upper yoke fault simulation device is mounted on the surface of an upper yoke of the transformer, a lower yoke fault simulation device is mounted on the surface of a lower yoke of the transformer, temperature detection modules are respectively arranged on two sides of the upper yoke fault simulation device and the lower yoke fault simulation device, the upper yoke fault simulation device and the lower yoke fault simulation device are connected through wires and then are connected to a switch control module, and the switch control module is connected with a power supply module;
the iron core single-point grounding point is connected with the current detection module and the data transmission module through a lead and then is connected to the background computer.
2. The transformer core multipoint ground fault simulation device of claim 1, wherein: the upper yoke fault simulation device and the lower yoke fault simulation device have the same structure and respectively comprise 5 sets of fault generation devices, wherein the 5 sets of fault generation devices are respectively distributed on the first-stage silicon steel sheet position, the 30% silicon steel sheet stage position, the 50% silicon steel sheet stage position, the 80% silicon steel sheet stage position and the 100% silicon steel sheet stage position of the upper yoke and the lower yoke of the transformer;
each set of fault generating device comprises 1 group of insulating guide plates, 1 single silicon steel sheet, 1 wood plate, 1 copper sheet, 1 spring, 1 pair of electronic traction electromagnets and 1 pair of traction ropes, wherein the insulating guide plates of 5 sets of fault generating devices of the upper iron yoke fault simulating device and the lower iron yoke fault simulating device are respectively fixed on the surfaces of the silicon steel sheets of the corresponding stages of the upper iron yoke and the lower iron yoke of the transformer, one end of the single silicon steel sheet is inserted in the middle of the insulating guide plates, the other end of the single silicon steel sheet is fixed on the wood plate with the copper sheet attached to the surface and communicated with the copper sheet, the copper sheet is connected with the ground through a lead, the other surface of the wood plate is connected with the spring, the other end of the spring is fixed at the top of the fault generating device, the 1 pair of electronic traction electromagnets are distributed at two sides of the spring and fixed at the top of the fault generating device, and the 1 pair of electronic traction electromagnets are connected with two ends of the wood plate through the traction ropes, so that the spring is in a compressed state;
the power input of the electronic traction electromagnet serves as a control end of the fault generating device, the corresponding control ends of the fault generating device installed on the upper iron yoke of the 5 sets of transformers and the fault generating device installed on the lower iron yoke of the 5 sets of transformers are connected into the switch control module and connected with the power module through 10 first normally closed electromagnetic relays, and 10 control buttons are distributed on the surface of the switch control module and correspondingly control the on-off of the 10 first normally closed electromagnetic relays.
3. A transformer core multipoint ground fault simulation apparatus according to claim 2, wherein: the current detection module comprises a current sensor, an overcurrent protection unit, a first controller and a first data transmission unit, wherein a lead of a single-point grounding point of the iron core is connected with a primary winding of the current sensor, the other end of the primary winding of the current sensor is connected with the overcurrent protection unit in series and then grounded, a secondary winding of the current sensor is connected with the first controller, and the first controller is communicated with a background computer through the first data transmission unit.
4. A transformer core multipoint ground fault simulation apparatus according to claim 2, wherein: the temperature detection module comprises 20 temperature sensors, a second controller and a second data transmission unit, the temperature sensors are sequentially distributed on two sides of the surface of the silicon steel sheet at the corresponding stage positions of the upper iron yoke and the lower iron yoke of the transformer, the temperature monitoring data of the upper iron yoke of the transformer and the temperature monitoring data of the lower iron yoke of the transformer are sent to the second controller through the temperature sensors, and the second controller is communicated with a background computer through the second data transmission unit.
5. A transformer core multipoint ground fault simulation apparatus according to claim 2, wherein: the oil chromatogram detection module comprises an oil chromatogram gas chromatograph, a third controller and a third control unit, the oil chromatogram gas chromatograph is connected with the oil taking port and sends a detection result to the third controller, and the third controller transmits the data to the background computer through the third data transmission unit after processing the data.
6. A transformer core multipoint ground fault simulation apparatus according to claim 3, wherein: the overcurrent protection unit comprises a second normally-closed electromagnetic relay and a current-limiting impedance which are connected in parallel.
7. A transformer core multipoint ground fault evaluation method using the transformer core multipoint ground fault simulation apparatus according to any one of claims 2 to 6, characterized in that: the method comprises the following steps:
s1: regulating the load of the high-voltage side winding and the low-voltage side winding of the transformer to enable the transformer to be in a full-load running state;
s2: when the transformer is in normal single-point grounding operation, the initial value I of the iron core single-point grounding current is recorded by the current sensor 1 And transmits the measured values (T) to the first controller, and the monitored values (T) of 20 temperature sensors are obtained 1 ,T 2 ,……,T 20 ) Transmitted to the second controller according to the formula
Calculating to obtain the initial single-point grounding temperatures of the iron cores on the surfaces of the silicon steel sheets at the positions of the upper iron yoke and the lower iron yoke of the transformer
）；
Wherein T is 1 、T 2 Respectively monitoring values T of temperature sensors at two sides of the first-stage silicon steel sheet position of the iron yoke on the transformer 3 、T 4 Temperature sensor monitor for two sides of 30% silicon steel sheet position of iron yoke on transformerMeasured value, T 5 、T 6 Respectively monitoring values T of temperature sensors at two sides of 50% silicon steel sheet position of iron yoke on transformer 7 、T 8 Respectively monitoring values T of temperature sensors at two sides of 80% silicon steel sheet position of iron yoke on transformer 9 、T 10 Respectively monitoring values T of temperature sensors at two sides of 100% silicon steel sheet position of iron yoke on transformer 11 、T 12 Respectively monitoring values T of temperature sensors at two sides of the first-stage silicon steel sheet position of the lower iron yoke of the transformer 13 、T 14 Respectively monitoring values T of temperature sensors at two sides of a 30% silicon steel sheet position of an iron yoke under the transformer 15 、T 16 Respectively monitoring values T of temperature sensors at two sides of 50% silicon steel sheet position of lower iron yoke of transformer 17 、T 18 Respectively monitoring values T of temperature sensors at two sides of 80% silicon steel sheet position of lower iron yoke of transformer 19 、T 20 Respectively monitoring values of temperature sensors at two sides of a 100% silicon steel sheet position of the lower iron yoke of the transformer,
、
respectively showing the initial temperatures of single-point grounding of iron cores on the surfaces of the silicon steel sheets at the first-stage silicon steel sheet positions of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively representing the initial temperature of single-point grounding of the iron core on the surface of the silicon steel sheet at the 30% silicon steel sheet level position of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively showing the initial temperature of single-point grounding of the iron core on the surface of the silicon steel sheet at the 50% silicon steel sheet level position of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively representing the initial temperature of single-point grounding of iron cores on the surfaces of silicon steel sheets at the grade positions of 80% silicon steel sheets of the upper iron yoke and the lower iron yoke of the transformer,
、
respectively representing the initial temperature of single-point grounding of iron cores on the surfaces of silicon steel sheets at the 100% silicon steel sheet level positions of an upper iron yoke and a lower iron yoke of the transformer;
detecting the content of each gas component in the iron core single-point grounding initial oil by an oil chromatography gas chromatograph (
) And transmitted to the third controller;
s3: setting different transformer iron core multipoint grounding faults through a control button of a control switch control module, and recording iron core multipoint grounding current value I through a current sensor 2 And transmitting the characteristic quantity A to a first controller, and processing the characteristic quantity A by the first controller to obtain a characteristic quantity A, wherein the expression of A is as follows:
recording the multipoint earthing temperature of the iron core on the surface of the silicon steel sheet at the multi-stage silicon steel sheet positions of the upper iron yoke and the lower iron yoke of the transformer monitored by 20 temperature sensors (
) And transmitting the characteristic quantity B to a second controller, and processing the characteristic quantity B by the second controller to obtain a characteristic quantity B, wherein the expression of B is as follows:
in the above formula: t is * The temperature of the iron core on the surface of the silicon steel sheet during multipoint earth fault is shown, and T shows the initial single-point earth temperature of the iron core on the surface of the silicon steel sheet;
monitoring the content of each gas component in the iron core multipoint grounding oil by an oil chromatography gas chromatograph (
) And transmitting the characteristic quantity C to a third controller, and calculating to obtain a characteristic quantity C, wherein the expression of C is as follows:
s4: sending the characteristic quantity A, B, C to a background computer through a data transmission module, and calculating to obtain a fault coefficient D, wherein
；
S5: and (4) after the transformer oil is filtered by the oil filtering module, replacing the multipoint grounding fault position, and repeating the steps S1-S4 to obtain the defect severity of the multipoint grounding underground transformer at different positions of the transformer core.
8. The method for evaluating the multipoint ground fault of the transformer core according to claim 7, wherein: judging the defect grade of multipoint grounding of different positions of the transformer by using a fault coefficient D, wherein the judgment formula is as follows:
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116449252A (en) * | 2023-06-20 | 2023-07-18 | 国网山西省电力公司电力科学研究院 | Online positioning device and method for multipoint grounding faults of transformer core |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015180002A1 (en) * | 2014-05-29 | 2015-12-03 | 国家电网公司 | Apparatus for judging failure of iron core and clamping part of ultra-high voltage electric reactor, and processing and eliminating same online |
| CN105207173A (en) * | 2014-05-29 | 2015-12-30 | 国网山西省电力公司电力科学研究院 | Device and method for monitoring, controlling and eliminating multipoint grounding of high-capacity transformer |
| CN106680650A (en) * | 2016-12-31 | 2017-05-17 | 西南交通大学 | Transformer core multi-point earthing fault testing device |
| CN108152653A (en) * | 2017-12-29 | 2018-06-12 | 国网山东省电力公司日照供电公司 | Transformer fault monitoring device and system |
| CN109085451A (en) * | 2018-08-30 | 2018-12-25 | 国网北京市电力公司 | The detection method and device of iron core grounding in transformer, storage medium |
| CN211785348U (en) * | 2019-12-11 | 2020-10-27 | 湖南长高思瑞自动化有限公司 | Be applied to oil chromatogram monitoring of transformer substation module on spot |
| CN112345967A (en) * | 2020-10-27 | 2021-02-09 | 四川革什扎水电开发有限责任公司 | Transformer iron core ground fault diagnosis simulation method and device based on equivalent method |
| CN213660189U (en) * | 2020-12-03 | 2021-07-09 | 武汉华杰电气工程有限公司 | Novel dry-type test transformer |
-
2023
- 2023-02-17 CN CN202310125849.0A patent/CN115825809B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015180002A1 (en) * | 2014-05-29 | 2015-12-03 | 国家电网公司 | Apparatus for judging failure of iron core and clamping part of ultra-high voltage electric reactor, and processing and eliminating same online |
| CN105207173A (en) * | 2014-05-29 | 2015-12-30 | 国网山西省电力公司电力科学研究院 | Device and method for monitoring, controlling and eliminating multipoint grounding of high-capacity transformer |
| CN106680650A (en) * | 2016-12-31 | 2017-05-17 | 西南交通大学 | Transformer core multi-point earthing fault testing device |
| CN108152653A (en) * | 2017-12-29 | 2018-06-12 | 国网山东省电力公司日照供电公司 | Transformer fault monitoring device and system |
| CN109085451A (en) * | 2018-08-30 | 2018-12-25 | 国网北京市电力公司 | The detection method and device of iron core grounding in transformer, storage medium |
| CN211785348U (en) * | 2019-12-11 | 2020-10-27 | 湖南长高思瑞自动化有限公司 | Be applied to oil chromatogram monitoring of transformer substation module on spot |
| CN112345967A (en) * | 2020-10-27 | 2021-02-09 | 四川革什扎水电开发有限责任公司 | Transformer iron core ground fault diagnosis simulation method and device based on equivalent method |
| CN213660189U (en) * | 2020-12-03 | 2021-07-09 | 武汉华杰电气工程有限公司 | Novel dry-type test transformer |
Non-Patent Citations (3)
| Title |
|---|
| XIU ZHOU 等: "Analysis of Multipoint Grounding Abnormality of Main Transformer" * |
| 何金海 等: "一起110kV变压器铁心多点接地故障的跟踪分析与现场处理" * |
| 周丹 等: "变压器铁心多点接地故障的模拟试验" * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116449252A (en) * | 2023-06-20 | 2023-07-18 | 国网山西省电力公司电力科学研究院 | Online positioning device and method for multipoint grounding faults of transformer core |
| CN116449252B (en) * | 2023-06-20 | 2023-09-19 | 国网山西省电力公司电力科学研究院 | Online positioning device and method for multipoint grounding faults of transformer core |
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|---|---|
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