Current transformer gas diffusion measurement method and gas detection system

Abstract

The invention relates to a gas diffusion measurement method and a gas detection system for a current transformer, and the method comprises the following steps: forming a cavity at one end of an insulating porcelain bushing of the current transformer, and filling the cavity with insulating oil; preparing a diffusion channel, communicating one end of the diffusion channel to the interior of the cavity, setting the other end of the diffusion channel as a sampling port and located at one end, far away from the cavity, of the current transformer insulating porcelain bushing, and filling the sampling port with insulating oil; a target temperature and a fault simulation type are set, after the insulating oil is heated to the target temperature, the insulating oil simulates an overheating fault and a breakdown fault, an oil sample in the sampling port is collected regularly within the duration of the overheating fault, and the target gas concentration of the oil sample is detected; and calculating the gas diffusion rate of the target gas according to the target gas concentration difference and the overheat fault duration. According to the invention, the sampling process of the insulating oil is simplified, the concentration change of the acetylene gas in the insulating oil is relatively accurately measured and analyzed, and the diffusion characteristics of the acetylene gas in the insulating oil of the current transformer are accurately monitored.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system equipment fault detection, in particular to a current transformer gas diffusion measurement method and a gas detection system. BACKGROUND

[0002] As a key insulation component in the power system, the operation state of the oil-immersed oil-filled current transformer is directly related to the safety and stability of the power system. In actual operation, overheating fault and breakdown fault are two common fault types, which will cause the decomposition of the internal insulation oil of the transformer and the generation of various characteristic gases including acetylene. The concentration change of acetylene gas is one of the key indicators for evaluating the nature and severity of the fault. It not only effectively reflects the early signs of local overheating or arc discharge, but also to some extent indicates the continuous deterioration trend of the insulation material. Therefore, it is necessary to accurately monitor the diffusion characteristics of the gas. Under the current detection technology system, the health status of the current transformer is judged by periodically taking oil manually and sending it back to the laboratory for analysis and detection of the types and concentrations of gases in the oil. The diffusion characteristics of acetylene gas in the internal insulation oil of the current transformer have not been systematically studied, resulting in a series of problems in equipment state evaluation and fault diagnosis, such as serious lag in fault warning, inability to achieve early intervention, difficulty in accurately locating the fault source, and affecting the maintenance efficiency, etc. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to overcome the problem of complicated sampling operation and low detection efficiency of the current transformer insulation oil in the prior art, and to provide a current transformer gas diffusion measurement method and a gas detection system, which can simplify the sampling process of the current transformer insulation oil, relatively accurately measure and analyze the concentration change of acetylene gas in the insulation oil, and accurately monitor the diffusion characteristics of acetylene gas in the current transformer insulation oil.

[0004] To solve the above technical problems, the present application provides a current transformer gas diffusion measurement method, comprising the following steps: A cavity is formed at one end of the current transformer insulation porcelain sleeve, and insulation oil is filled into the cavity; A diffusion channel is prepared, one end of the diffusion channel is connected to the inside of the cavity, the other end is set as a sampling port and is arranged at the end of the current transformer insulation porcelain sleeve away from the cavity, and the insulation oil is filled into the sampling port; The target temperature and the fault simulation type are set, the insulation oil is heated to the target temperature, the insulation oil simulates overheating fault and breakdown fault, the oil sample in the sampling port is collected periodically within the duration of the overheating fault, and the target gas concentration of the oil sample is detected; The gas diffusion rate of the target gas is calculated according to the target gas concentration difference and the overheating fault duration.

[0005] In one embodiment of the present application, the method further comprises the following steps: The angle of the diffusion channel is adjusted so that the insulating oil in the cavity diffuses upward to the sampling port through the diffusion channel; Before simulating the overheating fault and the breakdown fault, the duration of the overheating fault and the number of breakdown faults are preset.

[0006] In one embodiment of the present application, the step of heating the insulating oil to the target temperature is to wrap a heating tape outside the cavity and heat the cavity with the heating tape so that the insulating oil is heated to the target temperature. The temperature value of the insulating oil and the discharge voltage value of the breakdown fault are monitored and recorded in real time during the overheating fault duration.

[0007] In one embodiment of the present application, the overheating fault and the breakdown fault of the insulating oil are simulated 10 minutes after the insulating oil reaches the target temperature.

[0008] A gas detection system is also provided, which performs the current transformer gas diffusion measurement method, and the detection system comprises, A cavity filled with insulating oil and located at the bottom end of the current transformer insulating porcelain sleeve; A fault simulation device immersed in the insulating oil, the fault simulation device comprising a heating element and an internal electrode, the heating element heating the insulating oil, and the internal electrode being used to break down the insulating oil; A diffusion channel penetrating through the current transformer insulating porcelain sleeve, one end of the diffusion channel being in communication with the inside of the cavity, and the other end being provided as a sampling port and located at the top of the current transformer insulating porcelain sleeve.

[0009] In one embodiment of the present application, the cavity is provided with a connecting port penetrating through the inside thereof, and the connecting port is connected with one end of the diffusion channel.

[0010] In one embodiment of the present application, a temperature and discharge monitoring device provided outside the cavity is further included, and the temperature and discharge monitoring device is electrically connected with the heating element and the internal electrode.

[0011] In one embodiment of the present application, the temperature and discharge monitoring device comprises a temperature sensor and an ultra-high frequency discharge sensor.

[0012] In one embodiment of the present application, a gas collection device provided with a sampling end is further included, the gas collection device measuring the concentration of the target gas in the oil sample, and the sampling end being connected with the sampling port.

[0013] In one embodiment of the present application, an external heating element is further included, which is sleeved outside the current transformer insulating porcelain sleeve and the cavity.

[0014] The above technical solution of the present application has the following beneficial effects compared with the prior art: The current transformer gas diffusion measurement method disclosed by the present application simulates insulation oil overheating failure and breakdown failure in the cavity, truly simulates target gas generated when internal failure of an oil current transformer occurs, realizes the study of diffusion rules of the target gas under different failure types by periodically collecting oil samples and detecting concentration changes of the target gas in the oil samples, uses the diffusion channel to prolong the diffusion path of the insulation oil containing the target gas, so that the sampling port is away from the failure area, the diffusion path of the collected oil sample at the sampling port is longer compared with direct sampling in the cavity, the diffusion process of the target gas is more obvious, the change trend of the gas concentration is convenient to observe and measure, local high concentration interference caused by direct sampling in the cavity is avoided, and therefore the simulation degree of the experiment and the reliability of the data are improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in combination with the drawings, in which Figure 1 The flowchart of the current transformer gas diffusion measurement method disclosed by the present application is shown in Figure 2 The structural schematic diagram of the current transformer insulating porcelain sleeve, the current transformer oil tank cavity and the failure simulation device in the preferred embodiment of the present application is shown in Figure 3 The cross-sectional view of the current transformer insulating porcelain sleeve and the current transformer oil tank cavity with the failure simulation device is shown in Figure 1

[0016] The description of the reference numerals in the drawings is as follows: 1, current transformer oil tank cavity; 11, connecting port; 2, current transformer insulating porcelain sleeve; 21, sampling port; 22, diffusion channel; 23, inner cavity of the current transformer insulating porcelain sleeve; 3, built-in electrode; 4, heating element; 5, insulation oil. DETAILED DESCRIPTION

[0017] The present application will be further described below in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application. EMBODIMENT

[0018] As shown in Figure 1 A current transformer gas diffusion measurement method is disclosed, which includes the following steps: ​A cavity is formed at one end of the insulating porcelain sleeve of the current transformer, and insulating oil is filled into the cavity; A diffusion channel is prepared, one end of the diffusion channel is communicated to the inside of the cavity, and the other end is provided as a sampling port and is arranged at the end of the current transformer insulating porcelain sleeve away from the cavity, and the insulating oil is filled into the sampling port; The target temperature and the fault simulation type are set, the insulating oil is heated to the target temperature, the insulating oil simulates overheating fault and breakdown fault, the oil sample in the sampling port is collected periodically within the overheating fault duration, and the target gas concentration of the oil sample is detected; The gas diffusion rate of the target gas is calculated according to the target gas concentration difference and the overheating fault duration.

[0019] The current transformer gas diffusion measurement method described in the embodiment simulates overheating fault and breakdown fault of insulating oil in the cavity, truly simulates target gas generated by internal fault of the oil current transformer, realizes research on diffusion law of the target gas under different fault types by periodically collecting the oil sample and detecting the change of the target gas concentration in the oil sample, prolongs the diffusion path of the insulating oil containing the target gas by using the diffusion channel, makes the sampling port away from the fault area, the diffusion path of the oil sample collected at the sampling port is longer compared with sampling directly in the cavity, the diffusion process of the target gas is more obvious, the change trend of the gas concentration is convenient to observe and measure, local high concentration interference caused by direct sampling in the cavity is avoided, and therefore the simulation degree of the experiment and the reliability of the data are improved.

[0020] In an embodiment of the present application, the following steps are further included: setting a plurality of gradient target temperatures, overheating temperature intervals of overheating fault, and breakdown voltage value intervals of breakdown fault, simulating insulating oil fault by different combinations of the target temperature, the overheating temperature of the overheating fault and the breakdown voltage value, and further, the plurality of gradient target temperatures include 40℃, 50℃ and 60℃, the overheating temperature interval is 80℃-120℃, and the maximum value of the breakdown voltage value is 60kV.

[0021] In an embodiment of the present application, the overheating fault and the breakdown fault are simulated by setting a fault simulation device in the cavity, and the components of the fault simulation device are checked for correct installation and the cavity is checked for fullness of insulating oil before simulating the fault.

[0022] In an embodiment of the present application, the insulating oil is heated to the target temperature and stabilized before simulating the fault.

[0023] In an embodiment of the present application, the following steps are further included: The angle of the diffusion channel is adjusted so that the insulating oil in the cavity diffuses upward to the sampling port through the diffusion channel, and the purpose is to further prolong the diffusion path of the target gas. Before simulating the overheating fault and the breakdown fault, the duration of the overheating fault and the number of breakdown faults are preset.

[0024] In one embodiment of the present invention, oil sample sampling and testing are completed through the following steps: during the duration of the overheating fault, an oil sample is collected at the sampling port every 2 minutes, the content of characteristic gases in the oil sample is detected by a gas chromatograph, and the diffusion of characteristic gases is analyzed based on the detected concentration and time.

[0025] In one embodiment of the present invention, the step of heating the insulating oil to the target temperature is as follows: wrapping a heat tracing cable around the outside of the cavity and heating the cavity with the heat tracing cable, so that the insulating oil is heated to the target temperature; The temperature of the insulating oil and the discharge voltage of the breakdown fault are monitored and recorded in real time during the duration of the overheating fault.

[0026] In one embodiment of the present invention, after the insulating oil reaches the target temperature for 10 minutes, the simulation of the insulating oil overheating fault and breakdown fault begins. Example

[0027] For reference Figure 2 and Figure 3 As shown, a gas detection system is also provided, which performs the aforementioned current transformer gas diffusion measurement method. This detection system includes... Cavity 1 (current transformer oil tank cavity), which is filled with insulating oil 5 and located at the bottom of the current transformer insulating porcelain bushing 2. The insulating oil 5 is used for current transformer insulation and arc extinguishing. A fault simulation device is immersed in the insulating oil 5. The fault simulation device includes a heating element 4 and a built-in electrode 3. The heating element 4 heats the insulating oil 5 to overheat and simulates an overheating fault. The built-in electrode 3 is used to generate an arc discharge to break down the insulating oil 5 to simulate a breakdown fault. A diffusion channel 22 is provided through the insulating porcelain sleeve 2 of the current transformer. One end of the diffusion channel 22 is connected to the interior of the cavity 1, and the other end is set as a sampling port 21 and located at the top of the insulating porcelain sleeve 2 of the current transformer. The insulating oil 5 inside the cavity 1 diffuses to the sampling port 21.

[0028] For reference Figure 2 and Figure 3 As shown, in one embodiment of the present invention, the cavity 1 is provided with a connection port 11 that extends through its interior. The connection port 11 is connected to one end of the diffusion channel 22 so that the insulating oil 5 containing the target gas in the cavity 1 can enter the diffusion channel 22 evenly, thereby improving the detection accuracy of the target gas.

[0029] For referenceFigure 3 As shown, in one embodiment of the present invention, the insulating oil 5 inside the cavity 1 diffuses upward along the diffusion channel 22 to the sampling port 21. The purpose is to extend the diffusion path of the target gas, making the diffusion process of the target gas more obvious and the change trend more conducive to observation.

[0030] In one embodiment of the present invention, a temperature and discharge monitoring device (not shown) is disposed outside the cavity 1. The temperature and discharge monitoring device is electrically connected to the heating element 4 and the built-in electrode 3. The temperature and discharge monitoring device monitors the heating temperature of the heating element 4 and the discharge voltage of the built-in electrode 3.

[0031] In one embodiment of the present invention, the temperature and discharge monitoring device includes a temperature sensor and an ultra-high frequency discharge sensor. The temperature sensor is used to detect the temperature of the insulating oil 5, and the ultra-high frequency discharge sensor is used to detect the discharge voltage of the built-in electrode 3.

[0032] In one embodiment of the present invention, a gas collection device (not shown) with a sampling end is also included. The gas collection device is used to collect and measure the concentration of the target gas in the oil sample, and to analyze the relationship between the change of the target gas concentration and time. The sampling end is connected to the sampling port 21, and the target gas in the sampling port 21 enters the gas collection device through the sampling end.

[0033] In one embodiment of the present invention, an external heating element (not shown) is further provided outside the insulating porcelain sleeve 2 and cavity 1 of the current transformer, and the external heating element is configured as a heating tape.

[0034] For reference Figure 3 As shown, in one embodiment of the present invention, the inner cavity 23 of the current transformer insulating porcelain sleeve 2 is connected to the cavity 1, and the inner cavity 23 is also filled with insulating oil 5.

[0035] For reference Figure 3 As shown, in one embodiment of the present invention, the diffusion channel 22 passes through the inner cavity 23 of the current transformer insulating porcelain sleeve 2, and the diameter of the diffusion channel 22 is smaller than the diameter of the inner cavity 23.

[0036] The working principle of the gas detection system described in this invention is as follows: The heating element 4 and the built-in electrode 3 are installed into the cavity 1, and then the insulating oil 5 is filled into the cavity 1, the sampling end of the gas collection device is connected to the sampling port 21, and the temperature and discharge monitoring device is connected to the heating element 4 and the built-in electrode 3; after checking that each part is correctly connected, the temperature and discharge monitoring device and the fault simulation device are started, the insulating oil 5 is heated to a target temperature by using an external heating element, the fault simulation device performs fault simulation, and during the duration of the overheating fault, the target gas of the sampling port 21 is periodically collected by using the gas collection device and the concentration thereof is analyzed.

[0037] Obviously, the above embodiments are merely exemplary and are not intended to limit the embodiments. Based on the above description, one of ordinary skill in the art can make other different forms of changes or modifications. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or modifications derived therefrom are still within the protection scope of the present application.

Claims

1. A method of gas diffusion measurement for a current transformer, characterized by, The method comprises the following steps: A cavity is formed at one end of the insulation porcelain sleeve of the current transformer, and the cavity is filled with insulation oil; A diffusion channel is prepared, one end of the diffusion channel is connected to the inside of the cavity, and the other end is provided as a sampling port and is arranged at the end of the current transformer insulation porcelain sleeve away from the cavity, and the insulation oil is filled into the sampling port; A target temperature and a fault simulation type are set, the insulation oil is heated to the target temperature, the insulation oil simulates overheating fault and breakdown fault, the oil sample in the sampling port is collected periodically during the duration of the overheating fault, and the target gas concentration of the oil sample is detected; The gas diffusion rate of the target gas is calculated according to the target gas concentration difference and the duration of the overheating fault.

2. A method of gas diffusion measurement for a current transformer according to claim 1, characterized in that, The method further comprises the following steps: The angle of the diffusion channel is adjusted so that the insulation oil in the cavity diffuses upward to the sampling port through the diffusion channel; Before simulating the overheating fault and the breakdown fault, the duration of the overheating fault and the number of breakdown faults are preset.

3. The current transformer gas diffusion measurement method according to claim 1, wherein The step of heating the insulation oil to the target temperature is to wrap a heating tape around the outside of the cavity and use the heating tape to heat the cavity, so that the insulation oil is heated to the target temperature; The temperature value of the insulation oil and the discharge voltage value of the breakdown fault are monitored and recorded in real time during the duration of the overheating fault.

4. The method of claim 1, wherein, After the insulation oil reaches the target temperature for 10 minutes, the overheating fault and the breakdown fault of the insulation oil are simulated.

5. A gas detection system that performs the gas diffusion measurement method of a current transformer according to any one of claims 1 to 4, characterized by, The method comprises A cavity filled with insulation oil is located at the bottom end of the current transformer insulation porcelain sleeve; A fault simulation device is immersed in the insulation oil, the fault simulation device comprises a heating element and an embedded electrode, the heating element heats the insulation oil, and the embedded electrode is used to break down the insulation oil; A diffusion channel penetrates through the current transformer insulation porcelain sleeve, one end of the diffusion channel is connected to the inside of the cavity, and the other end is provided as a sampling port and is located at the top of the current transformer insulation porcelain sleeve.

6. A gas detection system according to claim 5, wherein, The cavity is provided with a connecting port penetrating through the inside thereof, and the connecting port is connected to one end of the diffusion channel.

7. The gas detection system of claim 5, wherein, The temperature and discharge monitoring device arranged outside the cavity is further included, and the temperature and discharge monitoring device is electrically connected to the heating element and the embedded electrode.

8. A gas detection system according to claim 7, wherein, The temperature and discharge monitoring device comprises a temperature sensor and a very high frequency discharge sensor.

9. The gas detection system of claim 5, wherein, The gas collection device provided with a sampling end is further included, the gas collection device measures the concentration of the target gas in the oil sample, and the sampling end is connected to the sampling port.

10. The gas detection system of claim 5, wherein, The external heating element sleeved outside the current transformer insulation porcelain sleeve and the cavity is further included.

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