A method of temperature monitoring of a power cable termination

Abstract

The application provides a temperature monitoring method for a wrapped power cable terminal, which comprises the following steps: installing a flexible sheet-shaped sensor on a stress cone and a capacitor cone; transmitting signal of multi-region temperature data obtained by the flexible sheet-shaped sensor through a wireless communication module; and sending a warning information based on the multi-region temperature data obtained by the flexible sheet-shaped sensor when any region temperature is greater than a preset maximum temperature, or any region temperature increasing speed is greater than a preset increasing speed, or any adjacent region temperature difference is greater than a maximum preset temperature difference. The flexible sheet-shaped sensor is installed on the stress cone and the capacitor cone, can closely adhere to the curved surface structure of the stress cone and the capacitor cone of the wrapped terminal, eliminates the temperature measurement gap, has low temperature conduction delay, high temperature measurement accuracy, can accurately capture the local temperature change of the terminal, can effectively analyze the real-time temperature and the temperature change trend, timely sends a warning signal, prolongs the service life of the terminal, and reduces the maintenance cost and the power failure risk.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, and more specifically, to a method for monitoring the temperature of a wrapped power cable terminal. Background Technology

[0002] Cable terminations are a core component of high-voltage cable systems, containing two key structures: a stress cone and a capacitance cone. The stress cone improves the electric field distribution at the cable termination, preventing insulation breakdown caused by localized electric field concentration. The capacitance cone further optimizes the electric field through capacitive voltage division, ensuring stable insulation performance. During long-term operation, factors such as current load fluctuations, insulation aging, and increased contact resistance can cause abnormal localized temperature rises in the stress and capacitance cone areas. Failure to monitor and intervene promptly can lead to serious faults such as insulation erosion and termination breakdown, resulting in power grid outages and significant economic losses and social impact.

[0003] Current cable terminal temperature measurement technologies are mainly divided into non-contact and contact temperature measurement. Non-contact technologies such as infrared thermal imaging do not require contact with the object being measured and have a fast response speed. However, they are obstructed by the terminal casing and cannot penetrate to the internal core area, only monitoring the surface temperature. Furthermore, the measurement results are greatly affected by environmental factors such as the medium and sunlight, easily leading to misjudgments of "cold outside, hot inside," and failing to reflect the true internal temperature rise. Contact temperature measurement uses sensors for measurement. Although it is lower in cost and more mature in technology, traditional sensors are large and difficult to conform to the irregular curved surfaces inside the terminal. They can only achieve single-point temperature measurement and cannot cover the temperature field distribution in multiple areas. Some linear temperature measurement solutions (such as temperature-sensing cables and fiber optic distributed systems) can achieve distributed monitoring, but optical fibers are prone to breakage and have high bending losses, temperature-sensing cables require damage to trigger an alarm, and the overall cost is high, which is not conducive to large-scale promotion.

[0004] With the continuous growth of power grid load, the proportion of cable terminal failures caused by abnormal temperature rise is increasing year by year. For wrapped cable terminals, existing temperature measurement technologies cannot accurately monitor the temperature of stress cones and capacitance cones, resulting in the failure to provide early warning of overheating faults inside the terminal. Repairs can only be carried out after a fault occurs, which is not only costly and time-consuming but also seriously affects the reliability of power grid supply. Therefore, researching temperature measurement technology for wrapped cable terminals is of great significance. This can help eliminate latent safety hazards in existing cables, improve the reliability of cable safety and stable operation, and reduce operation and maintenance costs.

[0005] Current temperature measurement solutions mainly fall into two categories: internal fixed sensing and surface temperature simulation / inversion. However, both have limitations. Internal fixed sensing generally lacks specialized sensor design, making it difficult to fully fit the unique capacitive cone and wrapping structure of cable terminals, resulting in inaccurate temperature measurements. While surface monitoring solutions can achieve circumferential temperature measurement, they only target the surface of the terminal sleeve and cannot reach internal core heat-generating areas such as stress cones and capacitive screens. They require mathematical models for simulation / inversion to calculate internal temperatures, heavily relying on preset parameters and sample datasets. For different specifications or types of cable terminals, adjustments or redesigns are necessary, limiting the versatility of the temperature measurement device. Summary of the Invention

[0006] In view of this, the present invention proposes a temperature monitoring method for wrapped power cable terminals, aiming to solve the problem that existing temperature measurement technologies cannot accurately monitor the temperature of stress cones and capacitor cones, resulting in the failure to provide early warning of overheating faults inside the terminals.

[0007] This invention proposes a temperature monitoring method for wrapped power cable terminals. The method includes the following steps: an installation step, in which a flexible sheet sensor is installed on a stress cone and a capacitance cone; a transmission step, in which the multi-region temperature data acquired by the flexible sheet sensor is transmitted via a wireless communication module; and an early warning step, in which, based on the multi-region temperature data acquired by the flexible sheet sensor, an early warning message is sent when the temperature of any region exceeds a preset maximum temperature, or the temperature increase rate of any region exceeds a preset increase rate, or the temperature difference between any adjacent regions exceeds a maximum preset temperature difference.

[0008] Furthermore, in the temperature monitoring method for the aforementioned wrapped power cable terminal, during the installation step, flexible sheet sensors are installed on the stress cone and capacitance cone during terminal fabrication.

[0009] Furthermore, in the above-mentioned temperature monitoring method for the wrapped power cable terminal, the installation of a flexible sheet sensor on the stress cone specifically involves: during the fabrication of the stress cone, attaching the flexible sheet sensor to the surface of the wrapping tape along the axial direction of the stress cone, pointing the sensor signal lead-out end toward the terminal outlet direction, starting the wrapping machine, continuing to wrap the middle and outer layers of the stress cone with the wrapping tape, embedding the flexible sheet sensor into the wrapping structure, and having the signal lead-out end pass through the pre-reserved wire hole at the terminal.

[0010] Furthermore, in the above-mentioned method for monitoring the temperature of the wrapped power cable terminal, the installation of a flexible sheet sensor on the capacitor cone specifically involves: attaching the flexible sheet sensor to the surface of the capacitor screen at the highest point of the electric field during the fabrication of the capacitor cone; continuing to stack the next layer to the top layer of the capacitor screen, clamping the flexible sheet sensor between the two layers of capacitor screen for fixation; finally, placing the flexible sheet sensor at the outer sleeve to measure the sleeve temperature, and leading out the sensor signal through the micro-threading hole reserved in the capacitor cone.

[0011] Furthermore, in the above-mentioned temperature monitoring method for wrapped power cable terminals, during the installation step, flexible sheet sensors are installed on the stress cone and capacitance cone during terminal operation.

[0012] Furthermore, in the above-mentioned temperature monitoring method for the wrapped power cable terminal, the installation of a flexible sheet sensor on the stress cone specifically involves: de-energizing the terminal, removing the terminal housing, attaching the flexible sheet sensor to the surface along the axial direction of the stress cone and rolling and pressing it, fixing the wireless communication module of the flexible sheet sensor to the inner wall of the terminal housing, connecting it to the flexible sheet sensor via a wire, and then installing the terminal housing.

[0013] Furthermore, in the above-mentioned temperature monitoring method for the wrapped power cable terminal, the installation of a flexible sheet sensor on the capacitor cone specifically involves: opening an installation hole on the capacitor cone, cleaning it, inserting the flexible sheet sensor through the installation hole, attaching it to the surface of the capacitor cone near the lead wire connection point, and finally placing the flexible sheet sensor at the outer sleeve to measure the sleeve temperature. The signal lead-out end of the flexible sheet sensor is led out through the wire hole reserved on the capacitor cone and connected to the wireless communication module outside the terminal. After installation, the installation hole is sealed with high-temperature resistant sealant.

[0014] Furthermore, in the above-mentioned temperature monitoring method for the wrapped power cable terminal, a narrow, long, flexible sheet sensor is installed on the stress cone, and a wide, short, flexible sheet sensor is installed on the capacitance cone.

[0015] Furthermore, in the above-mentioned temperature monitoring method for wrapped power cable terminals, the flexible sheet sensor includes: a flexible insulating substrate; a temperature sensing unit disposed on the flexible insulating substrate; and an encapsulation protective layer covering the temperature sensing unit on the flexible insulating substrate, wherein the main material of the encapsulation protective layer is elastic sealant.

[0016] Furthermore, in the above-mentioned temperature monitoring method for wrapped power cable terminals, the flexible insulating substrate is a polyimide film, the temperature sensing unit is a thermistor or platinum resistance thermometer, and the main material of the encapsulation protective layer is silicone rubber.

[0017] The temperature monitoring method for wrapped power cable terminals provided by this invention, by installing flexible sheet sensors on the stress cone and capacitance cone, can closely fit the curved surface structure of the stress cone and capacitance cone of the wrapped terminal, eliminating temperature measurement gaps, resulting in low temperature conduction delay and high temperature measurement accuracy. It can accurately capture local temperature changes in the terminal, effectively analyze real-time temperature and temperature change trends, and issue timely warning signals, extending the service life of the terminal, reducing maintenance costs and power outage risks. It solves the problem that existing temperature measurement technologies cannot accurately monitor the temperature of the stress cone and capacitance cone, resulting in the failure to provide early warning of internal overheating faults in the terminal.

[0018] Furthermore, the flexible sheet sensor offers flexibility in installation method and location. For newly manufactured terminals, prefabricated installation is possible without additional processing; for terminals already in operation, installation can be performed after removal, requiring only surface cleaning or the creation of micro-mounting holes (which, when sealed, do not affect the seal), thus avoiding damage to the terminal's insulation and structure. The sensor's position can be selected within the terminal, enabling the measurement of temperature at different locations within the terminal. Attached Figure Description

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating the temperature monitoring method for wrapped power cable terminals provided in an embodiment of the present invention; Figure 2 This is a simulation diagram of the internal electric field of a wrapped power cable terminal provided in an embodiment of the present invention; Figure 3 for Figure 2 A magnified view of a section at point D; Figure 4 This is a simulation diagram of the maximum field strength plate potential of the capacitor cone provided in an embodiment of the present invention; Figure 5 This is a simulation diagram of the electric field of the capacitor cone plate at maximum electric field strength provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the sensor installation position provided in an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1-Power cable terminal, 11-Porcelain bushing, 12-Capacitor cone, 13-Insulation layer, 14-Cable core, 15-Stress cone, 2-Wireless communication module, 21-4G antenna, 22-GPS antenna, 23-LoRa antenna. Detailed Implementation

[0020] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] See Figure 1 The figure shows a flowchart of a temperature monitoring method for a wrapped power cable terminal provided in an embodiment of the present invention. As shown, the method includes the following steps: Installation step S1: Install the flexible sheet sensor on the stress cone and the capacitance cone.

[0022] Specifically, the simulation can be based first on the internal electric field simulation of the wrapped power cable terminal 1 and the simulation results of the potential and electric field of the maximum field strength plate of the capacitor cone 12. The simulation diagram of the internal electric field of the wrapped power cable terminal 1 can be found in [reference needed]. Figure 2 and Figure 3 ,like Figure 2 As shown, the side of the wrapped power cable terminal 1 has an air region. The wrapped power cable terminal 1 has cable cores 14, insulation layer 13, and porcelain sleeve 11 arranged sequentially from the inside out. The top of the insulation layer 13 has a capacitor cone 12, and the bottom has a stress cone 15. The simulation diagram of the maximum field strength plate potential and electric field diagram of the capacitor cone 12 can be found in [reference needed]. Figure 4 and Figure 5 As shown, the mounting position of the flexible sheet sensor on capacitor cone 12 is determined, i.e. Figure 5 The location of maximum electric field is shown. In this embodiment, flexible sheet sensors need to be installed on the stress cone 15 and the capacitor cone 12. These sensors can closely fit the curved surface of the stress cone 15 and the stacked capacitor screen structure of the wrapping terminal, adapting to the internal shape of the wrapping terminal. Flexible sheet sensors can also be installed on the outer wall of the ceramic sleeve 11. The installation position of the flexible sheet sensors can be as follows... Figure 6Positions A, B, and C are shown. Based on these positions, flexible sheet sensors are installed on the stress cone 15 and the capacitance cone 12. The flexible sheet sensors employ an ultra-thin, flexible structure. Their width is customized according to the wrapping width of the stress cone 15 and capacitance cone 12, and their length can be cut according to the length of the temperature measurement area, ensuring a smooth, wrinkle-free, and gap-free fit along curved surfaces. For the stress cone 15: Since the stress cone 15 is a flexible wrapping structure with a certain curvature on its surface, the sensor needs to be designed as a "narrow, elongated strip" with rounded edges to avoid stress concentration during wrapping. This means a narrow, elongated flexible sheet sensor is installed on the stress cone 15. Simultaneously, a low-viscosity silicone rubber coating is applied to the surface of the sheet sensor to enhance its fit with the wrapping tape of the stress cone 15 and prevent slippage. Regarding the capacitor cone 12: The capacitor cone 12 is made of multiple layers of capacitor screens stacked together. The core heat-generating points are the joints of the capacitor screens and the lead wire connection points. The sensor is designed as a "wide and short strip", that is, a wide and short strip flexible sheet sensor is installed on the capacitor cone 12, and a temperature measuring element is placed at the voltage concentration point.

[0023] In this embodiment, the flexible sheet sensor can be installed in two ways, adapting to both newly manufactured wrapped cable terminals and existing wrapped cable terminals. Specifically, during the terminal fabrication process, the flexible sheet sensor is installed on the stress cone 15 and capacitance cone 12. Alternatively, the flexible sheet sensor can be installed on the stress cone 15 and capacitance cone 12 during terminal operation.

[0024] In one embodiment of the installation steps, the newly manufactured terminal is prefabricated, meaning the sensor is installed during terminal fabrication. During terminal fabrication, the flexible sheet sensor is attached to the surface of the wrapping tape along the axial direction of the stress cone 15 during stress cone 15 fabrication. The signal lead-out end of the flexible sheet sensor faces the terminal's outgoing wire direction. Then, the wrapping machine is started to continue wrapping the middle and outer layers of the stress cone 15 with wrapping tape (such as insulating tape or shielding tape), completely embedding the flexible sheet sensor into the wrapping structure. This ensures there are no gaps between the sensor and the wrapping tape, and the signal lead-out end passes through the pre-reserved wire hole on the terminal to connect with the external wireless communication module 2. The process is: bottom layer wrapping tape wrapping → sensor attachment → middle and outer layer wrapping tape wrapping → signal lead-out end. During the fabrication of capacitor cone 12, a customized flexible sheet sensor is attached to the surface of the capacitor screen at the highest electric field, ensuring that the temperature sensing element on the flexible sheet sensor is aligned with the capacitor screen seam and lead connection point. The next layer is then stacked to the top layer of the capacitor screen, and the flexible sheet sensor is sandwiched between the two layers of capacitor screen for fixation. Finally, the flexible sheet sensor is placed at the outer sleeve to measure the sleeve temperature. The sensor signal lead-out end is led out through the micro-wire hole reserved in capacitor cone 12 and connected to the wireless communication module 2 outside the terminal. The process is as follows: stack to the capacitor screen at the highest field strength layer → attach sensor → stack to the top layer of the capacitor screen → lead out signal end.

[0025] In another embodiment of the installation steps, the terminal is installed after removal. First, the terminal is powered off, and the terminal casing is removed. Then, the flexible sheet sensor is attached to the surface along the axis of the stress cone 15 and rolled and pressed to ensure a tight fit. The wireless communication module 2 of the flexible sheet sensor is fixed to the inner wall of the terminal casing and connected to the flexible sheet sensor via a wire. The terminal casing is then reinstalled, ensuring that the wireless communication module 2 is not obstructed by the casing. For the capacitor cone 12, a miniature mounting hole needs to be made. After cleaning, the flexible sheet sensor is inserted through the mounting hole and attached to the surface of the capacitor cone 12 near the lead connection point. Finally, the flexible sheet sensor is placed at the outer sleeve, and the sleeve temperature is measured. The signal lead of the flexible sheet sensor is led out through the miniature wire hole reserved in the capacitor cone 12 and connected to the wireless communication module 2 outside the terminal. After installation, the mounting hole is sealed with high-temperature resistant sealant to restore the casing's sealing performance. The process is: cleaning the surface → attaching the sensor → fixing and sealing → connecting the wireless communication module 2.

[0026] In transmission step S2, the multi-region temperature data acquired by the flexible sheet sensor is transmitted via a wireless communication module.

[0027] Specifically, the wireless communication module 2 can transmit signals of multi-region temperature data acquired by the flexible sheet sensor. In this embodiment, the wireless communication module 2 may include: a signal reader and a wireless gateway; the reader uses a 4G antenna 21, which provides an excitation signal through adaptive transmission power adjustment, effectively suppressing high-frequency interference and improving the signal-to-noise ratio; the transmission characteristics of the wireless communication module 2 may adopt the LoRa wireless communication protocol, which has a long transmission distance and high sampling frequency; the reader and the gateway are connected via an industrial Ethernet, supporting remote data access. The wireless communication module 2 may be equipped with a 4G antenna 21, a GPS antenna 22, and a LoRa antenna 23.

[0028] In the early warning step S3, based on the multi-region temperature data obtained by the flexible sheet sensor, when the temperature of any region exceeds the preset maximum temperature, or the temperature growth rate of any region exceeds the preset growth rate, or the temperature difference between any two adjacent regions exceeds the first maximum preset temperature difference, an early warning message is sent.

[0029] Specifically, based on multi-region temperature data acquired by flexible sheet sensors, an early warning message is sent when the temperature in any region exceeds a preset maximum temperature, the rate of temperature increase in any region exceeds a preset rate of increase, or the temperature difference between any two adjacent regions exceeds a maximum pre-defined temperature difference. The preset maximum temperature can be 65℃, the preset rate of increase can be 10℃ / h, and the maximum pre-defined temperature difference can be 15℃. Therefore, based on multi-region temperature data, an early warning signal sending logic is set: if the temperature in any region > 65℃, an abnormal temperature rise is considered possible, and an SMS warning is pushed; if the temperature in any region suddenly rises within a short period (>10℃ / h) without a significant increase in background load, an SMS warning is pushed; if the temperature difference between any two adjacent regions > 15℃, an SMS warning is pushed. Data storage and analysis: The platform stores temperature data and early warning records for up to two years, supports temperature trend analysis and historical data backtracking, and assists maintenance personnel in assessing the health status of terminals.

[0030] In this embodiment, the flexible sheet sensor includes: a flexible insulating substrate, a temperature sensing unit, and an encapsulation protective layer; wherein, the temperature sensing unit is disposed on the flexible insulating substrate; the encapsulation protective layer covers the temperature sensing unit on the flexible insulating substrate, and the main material of the encapsulation protective layer is elastic sealant.

[0031] Specifically, the flexible insulating substrate, serving as the support carrier for the sensor, is preferably made of polyimide (PI) film, which is resistant to high voltage and high temperature and has excellent insulation properties. Its thickness can be selected between 0.025 mm and 0.1 mm, for example, 0.05 mm. This substrate ensures that when the sensor is directly attached to the surface of live parts such as high-voltage cable terminals, it will not affect the original insulation performance of the equipment. Simultaneously, its excellent flexibility allows the sensor to fit tightly onto various curved surfaces. The temperature sensing unit is fixed to a pre-set electrode pattern on the flexible insulating substrate using conductive silver paste or a welding process. In this embodiment, the temperature sensing unit is preferably a high-precision negative temperature coefficient (NTC) thermistor chip, with a temperature measurement range of -40℃ to 150℃ and an accuracy of ±0.5℃. This element can accurately capture a wide range of temperature changes in the cable terminal, from normal operation to abnormal heating. It is understood that in other embodiments, the temperature sensing unit can also use other types of temperature-sensitive elements such as platinum resistance thermometers (e.g., PT1000). The encapsulation protective layer is the external protective structure of the entire sensor. It completely covers the flexible insulating substrate and the temperature sensing unit disposed thereon, forming an integrated sealed protection. The main material of the encapsulation protective layer is an elastic sealant. In a preferred embodiment of the present invention, the elastic sealant is an addition-type liquid silicone rubber. During construction, the liquid silicone rubber can be applied to the surface of the substrate assembly by means of dispensing, scraping, or molding, and then cured at room temperature or under heating conditions. The silicone rubber layer formed after curing has excellent elasticity, hydrophobicity, resistance to high and low temperature aging, and electrical insulation. Its thickness can be designed according to mechanical protection and thermal response requirements, for example, between 0.5 mm and 2 mm. This encapsulation protective layer has at least the following functions: First, it completely isolates the temperature sensing unit from the environment, preventing corrosion from moisture, dust, and chemical media, and ensuring long-term reliability; Second, the good thermal conductivity of silicone rubber helps heat to be transferred quickly to the internal NTC thermistor, while the elastomer properties can buffer external stress and protect the brittle thermistor chip; Third, as the outer surface of the sensor, its soft texture and elasticity allow it to bend with the substrate and adhere tightly to the surface of the object being measured, reducing contact thermal resistance and improving temperature measurement accuracy.

[0032] In summary, the temperature monitoring method for wrapped power cable terminals provided in this embodiment, by installing flexible sheet sensors on the stress cone 15 and capacitor cone 12, can closely fit the curved surface structure of the stress cone 15 and capacitor cone 12 of the wrapped terminal, eliminating temperature measurement gaps, resulting in low temperature conduction delay and high temperature measurement accuracy. It can accurately capture local temperature changes in the terminal, effectively analyze real-time temperature and temperature change trends, and issue warning signals in a timely manner, extending the service life of the terminal, reducing maintenance costs and power outage risks. It solves the problem that existing temperature measurement technologies cannot accurately monitor the temperature of the stress cone 15 and capacitor cone 12, resulting in the failure to provide early warning of internal overheating faults in the terminal.

[0033] Furthermore, the flexible sheet sensor offers flexibility in installation method and location. For newly manufactured terminals, prefabricated installation is possible without additional processing; for terminals already in operation, installation can be performed after removal, requiring only surface cleaning or the creation of micro-mounting holes (which, when sealed, do not affect the seal), thus avoiding damage to the terminal's insulation and structure. The sensor's position can be selected within the terminal, enabling the measurement of temperature at different locations within the terminal.

[0034] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0035] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for monitoring the temperature of a wrapped power cable terminal, characterized in that, Includes the following steps: Installation steps: Install flexible sheet sensors on the stress cone and capacitance cone; The transmission step involves transmitting the multi-region temperature data acquired by the flexible sheet sensor via a wireless communication module. The early warning process involves sending an early warning message based on multi-region temperature data acquired by a flexible sheet sensor. When the temperature in any region exceeds a preset maximum temperature, or the rate of increase in temperature in any region exceeds a preset rate of increase, or the temperature difference between any two adjacent regions exceeds a maximum preset temperature difference, an early warning message is sent. In the installation steps, during terminal fabrication, flexible sheet sensors are installed on the stress cone and the capacitance cone; specifically, installing the flexible sheet sensor on the stress cone involves: During the fabrication of the stress cone, a flexible sheet sensor is attached to the surface of the wrapping tape along the axis of the stress cone, with the sensor signal lead pointing towards the terminal lead direction. The wrapping machine is started to continue wrapping the middle and outer layers of the stress cone with the wrapping tape, embedding the flexible sheet sensor into the wrapping structure. The signal lead exits through the pre-drilled hole at the terminal. The flexible sheet sensor is then installed on the capacitor cone, specifically as follows: During the fabrication of the capacitor cone, a flexible sheet sensor is attached to the surface of the capacitor screen at the highest point of the electric field. The next layer is then stacked up to the top layer of the capacitor screen, and the flexible sheet sensor is sandwiched between the two layers of capacitor screen to achieve fixation. Finally, the flexible sheet sensor is placed at the outer sleeve to measure the sleeve temperature. The sensor signal lead-out end is led out through the micro wire hole reserved in the capacitor cone. In the installation step, during terminal operation, flexible sheet sensors are installed on the stress cone and the capacitance cone; specifically, installing the flexible sheet sensor on the stress cone involves: Power is cut off at the terminal, the terminal casing is removed, the flexible sheet sensor is attached to the surface along the axis of the stress cone and rolled and pressed, the wireless communication module of the flexible sheet sensor is fixed to the inner wall of the terminal casing, and connected to the flexible sheet sensor through a wire, and the terminal casing is installed; the installation of the flexible sheet sensor on the capacitor cone specifically involves: A mounting hole is made on the capacitor cone. After cleaning, the flexible sheet sensor is inserted through the mounting hole and attached to the surface of the capacitor cone near the lead wire connection point. Finally, the flexible sheet sensor is placed at the outer sleeve, and the sleeve temperature is measured. The signal lead-out end of the flexible sheet sensor is led out through the wire hole reserved on the capacitor cone and connected to the wireless communication module outside the terminal. After installation, the mounting hole is sealed with high-temperature resistant sealant.

2. The temperature monitoring method for the terminal of a wrapped power cable according to claim 1, characterized in that, A narrow, long, flexible sheet sensor is installed on the stress cone, and a wide, short, flexible sheet sensor is installed on the capacitance cone.

3. The temperature monitoring method for the terminal of a wrapped power cable according to claim 1, characterized in that, The flexible sheet sensor includes: Flexible insulating substrate; A temperature sensing unit is disposed on the flexible insulating substrate; An encapsulation protective layer covers the temperature sensing unit on the flexible insulating substrate, and the main material of the encapsulation protective layer is an elastic sealant.

4. The temperature monitoring method for the terminal of a wrapped power cable according to claim 3, characterized in that, The flexible insulating substrate is a polyimide film, the temperature sensing unit is a thermistor or a platinum resistance thermometer, and the main material of the encapsulation protective layer is silicone rubber.

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