Transformer bushing explosion-proof method and system

Abstract

The invention discloses a transformer bushing explosion-proof method and system. The anti-explosion method for the transformer bushing comprises the following steps: acquiring data of internal oil pressure, hydrogen dissolved quantity and discharge energy of the transformer bushing; data of internal oil pressure, hydrogen dissolved amount and discharge energy of the transformer bushing are compared with corresponding preset thresholds; and when at least two data of the internal oil pressure, the hydrogen dissolved amount and the discharge energy are greater than or equal to the corresponding preset threshold values, controlling a circuit breaker corresponding to the transformer bushing to be disconnected so as to stop supplying the fault arc energy to the transformer bushing. According to the anti-explosion method and system for the transformer bushing, anti-explosion monitoring on the transformer bushing is realized.

Description

Technical Field

[0001] This invention relates to the technical field of electrical equipment, and in particular to a method and system for explosion-proof transformer bushings. Background Technology

[0002] Transformer bushings are an important component of transformer equipment, serving functions such as electrical isolation, high-voltage conduction, mechanical support, and preventing leakage of insulating oil from the transformer's internal structure through the conductor outlet. Common transformer bushings are porcelain bushings, made entirely of porcelain material, suitable for various voltage levels.

[0003] In existing technologies, transformer bushings need to withstand high voltage, high current, high temperature, and high mechanical stress during operation. Transformer bushings are prone to arcing faults. In recent years, there have been frequent incidents of transformer bushing equipment escalating from arcing faults to deflagration, and even to major transformer fire accidents, causing significant economic losses and serious social impacts. The frequent occurrence of deflagration accidents in transformer bushings exposes the problem that the design of transformer bushings in existing technologies has not considered the urgent engineering requirements for deflagration prevention and lacks corresponding explosion-proof technical means. Summary of the Invention

[0004] To overcome one or more technical problems existing in the prior art, the present invention provides a method and system for explosion-proof transformer bushings, so as to realize explosion-proof monitoring of transformer bushings.

[0005] In a first aspect, the present invention provides a method for explosion-proofing transformer bushings, comprising the following steps: Collect data on the internal oil pressure, hydrogen dissolved amount, and discharge energy of the transformer bushing; The data on the internal oil pressure, hydrogen dissolution rate, and discharge energy of the transformer bushing are compared with the corresponding preset thresholds. When at least two of the following data—internal oil pressure, hydrogen dissolution rate, and discharge energy—are greater than or equal to the corresponding preset threshold, the circuit breaker corresponding to the transformer bushing is opened, thereby stopping the power supply to the transformer bushing.

[0006] Preferably, when the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement, the transformer bushing operating voltage level corresponding to the preset threshold is less than 110kV.

[0007] Preferably, when the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement and porcelain bushing explosion-proof sheet, the transformer bushing working voltage level corresponding to the preset threshold is greater than or equal to 110kV.

[0008] Preferably, an oil pressure sensor is used to collect the internal oil pressure of the transformer bushing in real time; The amount of hydrogen dissolved in the transformer bushing is collected in real time using a hydrogen sensor. The discharge energy of the transformer bushing is collected in real time using a pulsed current partial discharge sensor.

[0009] Preferably, before collecting data on the internal oil pressure, hydrogen dissolved amount, and discharge energy of the transformer bushing, the following steps are also included: Identify the operating voltage level of the transformer bushing to determine the corresponding preset threshold.

[0010] In a second aspect, the present invention provides a transformer bushing explosion-proof system, including a transformer bushing, a sensor module, a controller, and a circuit breaker; The transformer bushing is electrically connected to the circuit breaker, the sensor module is mounted on the transformer bushing, and the controller is electrically connected to both the sensor module and the circuit breaker. The sensor module is used to collect data on the internal oil pressure, hydrogen dissolved amount, and discharge energy of the transformer bushing; The controller is used to compare the data of internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing with the corresponding preset thresholds. The controller is used to control the circuit breaker corresponding to the transformer bushing to open and stop supplying power to the transformer bushing when at least two of the following data are greater than or equal to the corresponding preset thresholds: internal oil pressure, hydrogen dissolved amount, and discharge energy.

[0011] Preferably, when the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement, the transformer bushing operating voltage level corresponding to the preset threshold is less than 110kV.

[0012] Preferably, when the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement and porcelain bushing explosion-proof sheet, the transformer bushing working voltage level corresponding to the preset threshold is greater than or equal to 110kV.

[0013] Preferably, the sensor module includes an oil pressure sensor, a hydrogen sensor, and a pulse current partial discharge sensor; The oil pressure sensor is used to collect the internal oil pressure of the transformer bushing in real time; The hydrogen sensor is used to collect the amount of hydrogen dissolved in the transformer bushing in real time; The pulse current partial discharge sensor is used to collect the discharge energy of transformer bushings in real time.

[0014] Preferably, the controller is equipped with a preset threshold module; The preset threshold module is used to identify the operating voltage level of the transformer bushing and thus determine the corresponding preset threshold.

[0015] Compared with existing technologies, the transformer bushing explosion-proof method and system of the present invention have the following advantages: Based on the differences in operating voltage levels, different transformer bushing structure configurations are adopted to ensure the explosion-proof requirements of transformer bushings while taking into account economy. At the same time, explosion-proof is achieved by real-time monitoring of the relevant status variables of transformer bushings and controlling whether the transformer is connected to the circuit, thereby improving the safety performance of transformer bushings. Attached Figure Description

[0016] Figure 1 This is a flowchart of one of the transformer bushing explosion-proof methods of the present invention.

[0017] Figure 2 for Figure 1 A schematic diagram of the structure of a transformer bushing used for operating voltage levels of 110kV and above.

[0018] Figure 3 This is a structural framework diagram of one of the transformer bushing explosion-proof systems of the present invention.

[0019] exist Figure 2 In the diagram, the labels and their corresponding names are as follows: 1-oil conservator, 2-conductor, 3-porcelain sleeve, 4-core, 5-measuring terminal, 6-mechanical flange, 7-upper fastener, 8-lower fastener, 9-equalizing ball, 10-oil conservator explosion-proof plate, 11-porcelain sleeve explosion-proof plate, 12-clasp, 13-reinforcing rib, 14-oil chamber. Detailed Implementation

[0020] Please refer to the diagrams, where the same component symbols represent the same components. The principles of the invention are illustrated by way of example implemented in a suitable operating environment. The following description is based on the illustrative specific embodiments of the invention and should not be construed as limiting the invention to other specific embodiments not detailed herein.

[0021] Please refer to Figure 1 The transformer bushing explosion-proof method of this embodiment includes the following steps.

[0022] S1. Select the appropriate transformer bushing structure according to the working voltage level and the expected energy of the fault arc. Specifically: S11. When the working voltage level is less than 110kV (kV: kilovolt) and the expected fault arc energy is less than 1MJ (MJ: megajoule), the selected transformer bushing structure is porcelain bushing with adhesive reinforcement combined with flange mechanical reinforcement. S12. When the working voltage level is greater than or equal to 110kV and the expected fault arc energy is greater than or equal to 1MJ, the selected transformer bushing structure is a porcelain bushing with adhesive reinforcement combined with a flange mechanical reinforcement and an added porcelain bushing explosion-proof plate. In this embodiment, there is a phenomenon in the electrical system where arc current flows through an unexpected electrical path. Such unexpected arcs are often uncontrollable, so this type of phenomenon is often called an arc fault, and the corresponding arc is called a fault arc. The appearance of a fault arc means that there are uncontrollable factors in the electrical system, such as the intervention of foreign objects, that cause arc short circuits and reduce electrical clearances. The energy of the fault arc varies depending on the actual working conditions, power transmission and distribution specifications, and other factors. Combination Figure 2 As shown, the transformer bushing structure involved in step S12 includes an oil conservator 1, a conductor 2, a porcelain bushing 3, a core 4, a measuring terminal 5, a mechanical flange 6, an upper fastener 7, a lower fastener 8, an equalizing ball 9, an oil conservator explosion-proof plate 10, a porcelain bushing explosion-proof plate 11, a buckle 12, a reinforcing rib 13, and an oil chamber 14. Combination Figure 2 As shown, the oil conservator 1 is connected to one end of the porcelain bushing 3. The oil conservator 1 is equipped with an oil conservator explosion-proof sheet 10. The conductor 2 passes through one end of the transformer bushing to the other end. One end of the transformer bushing corresponds to the oil conservator 1, and the other end corresponds to the equalizing ball 9. The core 4 covers the outer periphery of the conductor 2, and the porcelain bushing 3 covers the outer periphery of the core 4, with a gap between the porcelain bushing 3 and the core 4 connecting to the oil conservator 1. One end of the porcelain bushing 3 is connected to the oil chamber 14 of the oil conservator 1. Both the oil conservator 1 and the oil chamber 14 store the oil used in the transformer bushing. When the conductor 2 is energized, it will dissolve hydrogen gas in the oil used in the transformer bushing, increasing the internal oil pressure of the transformer bushing. The mechanical flange 6 is reinforced by the porcelain bushing and connected to the middle position of the porcelain bushing 3. The mechanical flange 6 is also connected to the middle of the porcelain bushing 3 by a snap-fit ​​12, which enhances the mechanical strength of the connection between the mechanical flange 6 and the porcelain bushing 3. The reinforcing rib 13 is part of the mechanical flange 6 body and is used to improve the structural strength of the mechanical flange 6 to reduce the risk of deformation and breakage of the mechanical flange 6 during arc faults. The equalizing ball 9 is connected to the other end of the transformer bushing through the upper fastener 7 and the lower fastener 8. The porcelain bushing explosion-proof plate 11 is located on the outside of the middle position of the porcelain bushing 3 and connects to the inside of the porcelain bushing 3. The measuring terminal 5 is located on the side of the middle position of the porcelain bushing 3 opposite to the porcelain bushing explosion-proof plate 11, and is used to connect to the oil pressure sensor, hydrogen sensor, and pulse current partial discharge sensor. The oil conservator explosion-proof plate 10 and the porcelain bushing explosion-proof plate 11 are made of graphite. When the internal oil pressure of the transformer bushing exceeds a certain value, the oil conservator explosion-proof plate 10 and the porcelain bushing explosion-proof plate 11 will break to release pressure, while under normal operating conditions, the oil conservator explosion-proof plate 10 and the porcelain bushing explosion-proof plate 11 will remain intact.

[0023] The structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement in step S11, compared to Figure 2 The structure shown removes the structure of the porcelain sleeve explosion-proof plate 11 and seals this area. The porcelain sleeve is reinforced by using concrete adhesive to fix the mechanical flange 6 to the outside of the porcelain sleeve 3.

[0024] S2. Install an oil pressure sensor, a hydrogen sensor, and a pulse current partial discharge sensor at the measuring terminal 5 of the transformer bushing to collect three state quantities in real time: internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing. In this embodiment, the three state quantities corresponding to the oil pressure sensor, hydrogen sensor, and pulse current partial discharge sensor are all data collected in real time of the internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing; when a fault arc occurs, these state quantities such as internal oil pressure, hydrogen dissolution amount, and discharge energy will change significantly. When electricity is applied to a transformer bushing, heat is generated, which increases the internal oil pressure. This can also cause changes in the amount of hydrogen dissolved in the oil of the transformer bushing, and may also lead to local pulse current discharge.

[0025] S3. Compare the data of internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing with the preset threshold values ​​of the corresponding state quantities. In this embodiment, the internal oil pressure, hydrogen dissolution amount, and discharge energy correspond to preset oil pressure threshold, preset dissolution amount threshold, and preset discharge energy threshold, respectively. The specific values ​​of the preset oil pressure threshold, preset dissolution amount threshold, and preset discharge energy threshold are set according to the different transformer bushing structures in step S1. The preset oil pressure threshold, preset dissolution amount threshold, and preset discharge energy threshold are also different for different working voltage levels and expected fault arc energy.

[0026] S4. When the data of at least two of the following state quantities—internal oil pressure, hydrogen dissolution amount, and discharge energy—are greater than or equal to the corresponding preset threshold, the corresponding circuit breaker on the transformer bushing power supply line is controlled to open, thereby shortening the duration of the electric arc fault in the transformer bushing, reducing the electric arc energy, and preventing the bushing from exploding. In this preferred embodiment, if the data of any two of the internal oil pressure, hydrogen dissolution amount, and discharge energy are greater than or equal to the corresponding preset oil pressure threshold, preset dissolution amount threshold, and preset discharge energy threshold, the corresponding circuit breaker on the transformer bushing power supply line can be switched to the open state to stop supplying power to the transformer bushing.

[0027] In this embodiment, the power supply control of the transformer bushing can be achieved by electrically connecting the oil pressure sensor, hydrogen sensor, pulse current partial discharge sensor, and circuit breaker to the PLC controller, thereby preventing explosion.

[0028] Compared with the prior art, this embodiment adopts different transformer bushing structure configurations based on the difference in working voltage level. While ensuring the explosion-proof requirements of the transformer bushing, it also takes into account economy. At the same time, it improves the safety performance of the transformer bushing by real-time monitoring of the relevant state variables of the transformer bushing and controlling whether the transformer is connected to the circuit.

[0029] Please refer to Figure 3 The transformer bushing explosion-proof system of this embodiment includes a transformer bushing, a sensor module, a controller, and a circuit breaker.

[0030] The sensor module includes an oil pressure sensor, a hydrogen sensor, and a pulse current partial discharge sensor.

[0031] The controller module includes a data comparison module, a preset threshold module, and a transformer bushing selection module.

[0032] Combination Figure 2 and Figure 3 As shown, the upper measuring terminal 5 of the transformer bushing is connected to an oil pressure sensor, a hydrogen sensor, and a pulse current partial discharge sensor. The oil pressure sensor, hydrogen sensor, and pulse current partial discharge sensor respectively collect data on three state quantities of the transformer bushing: internal oil pressure, hydrogen dissolution amount, and discharge energy. The specific connection method can be set according to different sensor types.

[0033] The oil pressure sensor, hydrogen sensor, and pulse current partial discharge sensor are electrically connected to the controller to input real-time data on three state quantities of the transformer bushing: internal oil pressure, hydrogen dissolution rate, and discharge energy. Specifically, the real-time data on these three state quantities are input to the controller's data comparison module.

[0034] The preset threshold module is connected to the data comparison module. The preset threshold module is used to input preset oil pressure threshold, preset dissolution threshold, and preset discharge energy threshold into the data comparison module. The specific values ​​of the preset oil pressure threshold, preset dissolution threshold, and preset discharge energy threshold are set according to the different transformer bushing structures. The preset oil pressure threshold, preset dissolution threshold, and preset discharge energy threshold also differ for different operating voltage levels and expected fault arc energy. Specifically, the preset threshold module includes a first preset threshold unit, a second preset threshold unit, and a selection unit. The first and second preset threshold units are connected to the selection unit. The preset threshold of the first preset threshold unit is set to the transformer bushing when the corresponding operating voltage level is less than 110kV and the expected fault arc energy is less than 1MJ. The preset threshold of the second preset threshold unit is set to the transformer bushing when the corresponding operating voltage level is greater than or equal to 110kV and the expected fault arc energy is greater than or equal to 1MJ. The selection unit is connected to the data comparison module. The selection unit is used to input the preset threshold of the first or second preset threshold unit into the data comparison module according to the actual selected transformer bushing structure. The selection unit is also electrically connected to the transformer bushing to identify the operating voltage level of the transformer bushing and thus determine whether to connect to the first or second preset threshold unit.

[0035] The controller is electrically connected to the circuit breaker and is used to control the opening or closing state of the circuit breaker. Specifically, the controller's data comparison module is electrically connected to the circuit breaker and is used to control the opening or closing state of the circuit breaker.

[0036] The circuit breaker is connected to a data comparison module. This module compares the data of the transformer bushing's internal oil pressure, hydrogen dissolution rate, and discharge energy with corresponding preset oil pressure thresholds, preset dissolution rate thresholds, and preset discharge energy thresholds. When at least two of these parameters are greater than or equal to their respective preset thresholds, the module outputs a signal to the circuit breaker control module to disconnect the circuit breaker. Preferably, in this embodiment, the circuit breaker is only required to output a signal to disconnect the power supply when any two of these parameters are greater than or equal to their respective preset thresholds.

[0037] Circuit breakers are used to control whether power is supplied to the transformer bushings.

[0038] Compared with the prior art, this embodiment adopts different transformer bushing structure configurations based on the difference in working voltage level. While ensuring the explosion-proof requirements of the transformer bushing, it also takes into account economy. At the same time, it improves the safety performance of the transformer bushing by real-time monitoring of the relevant state variables of the transformer bushing and controlling whether the transformer is connected to the circuit.

[0039] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0040] The above description is only a partial embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for explosion-proofing transformer bushings, characterized in that, Including the following steps: Data on the internal oil pressure, hydrogen dissolution rate, and discharge energy of the transformer bushing were collected. The data on the internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing are compared with the corresponding preset thresholds. When at least two of the following data—internal oil pressure, hydrogen dissolution amount, and discharge energy—are greater than or equal to the corresponding preset threshold, the circuit breaker corresponding to the transformer bushing is opened to stop supplying power to the transformer bushing.

2. The explosion-proof method for transformer bushings according to claim 1, characterized in that, When the transformer bushing adopts a structure of porcelain bushing with adhesive reinforcement combined with flange mechanical reinforcement, the transformer bushing operating voltage level corresponding to the preset threshold is less than 110kV.

3. The explosion-proof method for transformer bushings according to claim 1, characterized in that, When the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement and porcelain bushing explosion-proof plate, the transformer bushing working voltage level corresponding to the preset threshold is greater than or equal to 110kV.

4. The explosion-proof method for transformer bushings according to claim 1, characterized in that, The internal oil pressure of the transformer bushing is collected in real time using an oil pressure sensor. The amount of hydrogen dissolved in the transformer bushing is collected in real time using a hydrogen sensor. The discharge energy of the transformer bushing is collected in real time using a pulsed current partial discharge sensor.

5. The explosion-proof method for transformer bushings according to claim 1, characterized in that... Before collecting data on the internal oil pressure, hydrogen dissolved amount, and discharge energy of the transformer bushing, the following steps are also included: Identify the operating voltage level of the transformer bushing to determine the corresponding preset threshold.

6. A transformer bushing explosion-proof system, characterized in that, This includes transformer bushings, sensor modules, controllers, and circuit breakers; The transformer bushing is electrically connected to the circuit breaker, the sensor module is mounted on the transformer bushing, and the controller is electrically connected to both the sensor module and the circuit breaker. The sensor module is used to collect data on the internal oil pressure, hydrogen dissolved amount, and discharge energy of the transformer bushing; The controller is used to compare the data of internal oil pressure, hydrogen dissolution amount, and discharge energy of the transformer bushing with the corresponding preset thresholds. The controller is used to control the circuit breaker corresponding to the transformer bushing to open and stop supplying power to the transformer bushing when at least two of the following data are greater than or equal to the corresponding preset threshold: internal oil pressure, hydrogen dissolution amount, and discharge energy.

7. The transformer bushing explosion-proof system according to claim 6, characterized in that, When the transformer bushing adopts a structure of porcelain bushing with adhesive reinforcement combined with flange mechanical reinforcement, the transformer bushing operating voltage level corresponding to the preset threshold is less than 110kV.

8. The transformer bushing explosion-proof system according to claim 6, characterized in that, When the transformer bushing adopts a structure of porcelain bushing adhesive reinforcement combined with flange mechanical reinforcement and porcelain bushing explosion-proof plate, the transformer bushing working voltage level corresponding to the preset threshold is greater than or equal to 110kV.

9. The transformer bushing explosion-proof system according to claim 6, characterized in that, The sensor module includes an oil pressure sensor, a hydrogen sensor, and a pulse current partial discharge sensor. The oil pressure sensor is used to collect the internal oil pressure of the transformer bushing in real time. The hydrogen sensor is used to collect the amount of hydrogen dissolved in the transformer bushing in real time. The pulse current partial discharge sensor is used to collect the discharge energy of the transformer bushing in real time.

10. The transformer bushing explosion-proof system according to claim 6, characterized in that, The controller is equipped with a preset threshold module; The preset threshold module is used to identify the operating voltage level of the transformer bushing and thus determine the corresponding preset threshold.

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