Wireless temperature measurement system and method suitable for low-current bus switch cabinet

Abstract

The application discloses a kind of wireless temperature measurement system and method suitable for low-current bus switch cabinet, belong to switch cabinet wireless temperature measurement technical field, mainly for switch cabinet wireless temperature measurement, to solve the technical problem of low-current bus temperature measurement power supply reliability and low temperature measurement accuracy.The system includes temperature difference self-powered module, temperature measurement module, data processing module, LoRa repeater and background data center;Temperature difference self-powered module is sequentially electrically connected by temperature difference power generation component, DC-DC converter and energy storage device, and is set by adhering bus through heat-conducting base, temperature measurement module adopts platinum resistance sensor and infrared auxiliary sensor dual-channel acquisition, temperature data is dynamically calibrated by preset temperature compensation model in data processing module;LoRa repeater transmits data, and background data center receives data and draws temperature rise curve.The application does not need external power supply and battery replacement, and the temperature measurement accuracy in low-current environment reaches ±0.5℃, realizes low-current bus passive, high-precision, long-term online temperature measurement.

Description

Technical Field

[0001] This invention relates to the field of wireless temperature measurement technology for switchgear, and in particular to a wireless temperature measurement system and method suitable for low-current busbar switchgear. Background Technology

[0002] Switchgear is a core electrical device in power systems used for power distribution, control, and protection. It is mainly used in substations, industrial control cabinets, and small substations. Internally, it integrates components such as busbars, circuit breakers, and contactors. Its core function is to carry and distribute electrical energy and provide overload and short-circuit protection to prevent the escalation of electrical faults. When switchgear is used in small buildings, commercial facilities, or localized power distribution circuits where current carrying capacity requirements are lower, low-voltage switchgear with a main busbar rated current ≤5A is used to reduce costs and facilitate installation. This low-current busbar switchgear has a simpler structure, lower heat dissipation requirements, and lower cost compared to high-current switchgear (such as 4000A class). However, regardless of whether it is high-current or low-current busbar switchgear, critical components such as busbar joints and cable connections can experience increased contact resistance due to oxidation, loosening, and poor contact during long-term operation. This can lead to abnormal temperature rise, potentially causing electrical equipment failure or even electrical fires. Therefore, in order to prevent power safety accidents and ensure the stable operation of the power system, it is necessary to monitor the temperature of the switchgear busbar in real time and accurately.

[0003] Currently, low-current busbar equipment is increasingly used in scenarios such as power distribution rooms and industrial control cabinets. However, existing wireless temperature measurement technologies have the following problems in monitoring the temperature of low-current busbar switchgear:

[0004] Firstly, the power supply reliability of sensors used for monitoring is insufficient, resulting in high maintenance costs and safety hazards. Existing wireless temperature sensors are mainly powered by either electromagnetic induction or battery power. Electromagnetic induction relies on electromagnetic energy generated by the bus current, but it is only suitable for high-current scenarios. In low-current bus environments, the weak bus current means the energy generated by electromagnetic induction is insufficient to support normal sensor operation—the magnetic core is not saturated at low currents, resulting in large permeability variations and extremely low electromagnetic coupling efficiency. Furthermore, limitations in the primary and secondary winding ratio design further lead to low energy conversion efficiency, making it impossible to provide a stable power supply to the sensor. While traditional battery power can adapt to low-current scenarios, batteries have inherent lifespan limitations. In the enclosed, high-temperature operating environment of switchgear, battery life is significantly shortened, requiring frequent power outages for replacement. This not only increases the workload and maintenance costs for operators but may also affect the normal power supply of the power system. Simultaneously, batteries in high-temperature, enclosed environments pose safety risks such as leakage, bulging, and even explosion, seriously threatening the operational safety of the switchgear. For example, the low-voltage switchgear temperature measurement system disclosed in CN105424202A uses button batteries for power supply. During long-term operation at low current, it requires regular maintenance and cannot achieve maintenance-free operation, and it also poses the aforementioned safety hazards.

[0005] Secondly, temperature measurement accuracy is difficult to guarantee, making it impossible to accurately capture abnormal temperature rises in low-current scenarios. Low-current busbars inherently generate less heat, and the temperature difference between the busbar and the environment is small. In this case, the interference from ambient temperature is significantly amplified, leading to a substantial increase in measurement errors using conventional temperature measurement methods, reaching ±3℃ or more. This fails to accurately reflect the true temperature state of critical parts of the busbar. Among existing temperature measurement technologies, infrared thermometry is widely used due to its non-contact measurement characteristics. However, this method is limited by line of sight, unable to penetrate obstructions such as switchgear doors and insulating partitions, making it difficult to capture the temperature of critical parts of the busbar within the enclosed cabinet. Simultaneously, reflections from metal components inside the switchgear interfere with infrared signal acquisition, further reducing measurement accuracy. This interference is particularly pronounced in low-current, low-heat-generating scenarios. For example, the infrared mobile temperature measurement scheme disclosed in CN112729557A is affected by metal reflections, making it difficult to accurately capture low-power heat points within the enclosed cabinet, thus failing to meet the temperature measurement accuracy requirements for low-current busbars.

[0006] Therefore, there is an urgent need for a wireless temperature measurement system and method suitable for low-current bus switchgear to ensure temperature monitoring of low-current bus switchgear, and to ensure the self-power supply and temperature measurement accuracy of the temperature measurement system. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a wireless temperature measurement system and method suitable for low current bus switchgear. It is mainly used for wireless temperature measurement of switchgear, realizing passive, high-precision, long-term online temperature measurement of low current busbars, improving the safety and reliability of switchgear operation, and reducing operation and maintenance costs.

[0008] This invention discloses a wireless temperature measurement system suitable for low-current busbar switchgear.

[0009] It includes a self-powered temperature measurement module, a data processing module, a LoRa repeater, and a back-end data center; the self-powered temperature measurement module includes a temperature difference self-powered module and a temperature measurement module;

[0010] The thermoelectric self-powered module includes a thermoelectric generator, a DC-DC converter, and an energy storage device connected in sequence. The thermoelectric generator is also equipped with a heat-conducting base, which is attached to the low-current bus.

[0011] The temperature measurement module includes a platinum resistance sensor, an infrared auxiliary sensor, and a dual-channel AD conversion chip. The platinum resistance sensor is installed on the low-current bus, and the infrared auxiliary sensor is installed on the outside of the switch cabinet. Both the platinum resistance sensor and the infrared auxiliary sensor are communicatively connected to the dual-channel AD conversion chip, and both the platinum resistance sensor and the infrared auxiliary sensor are electrically connected to the energy storage device.

[0012] The data processing module is connected to a dual-channel AD conversion chip, and is also connected to an ammeter for acquiring real-time bus current values. The data processing module has a built-in temperature compensation model for correcting the acquired temperature data; the calculation formula for the temperature compensation model is as follows:

[0013]

[0014] Among them, I 母线 —Real-time bus current, T 环境 —Ambient temperature collected by the infrared auxiliary sensor; T 采集 —Bus temperature collected by platinum resistance sensor;

[0015] The LoRa repeater is installed on the top of the switch cabinet. The LoRa repeater is communicatively connected to the data processing module and the back-end data center.

[0016] The back-end data center is used to receive the actual bus temperature data obtained by the temperature compensation model and to plot the temperature rise curve.

[0017] Furthermore, the thermoelectric power generation component includes a bismuth telluride thermal power generation chip. The hot end of the bismuth telluride thermal power generation chip is attached to the busbar via a heat-conducting base. The cold end of the bismuth telluride thermal power generation chip is connected to an aluminum alloy heat sink fin. The aluminum alloy heat sink fin is located on the top of the energy storage device. The bismuth telluride thermal power generation chip is electrically connected to a DC-DC converter. The heat-conducting base is made of aluminum nitride ceramic material. The energy storage device uses a lithium titanate battery.

[0018] Furthermore, the temperature difference self-powered module and the temperature measurement module are integrated into the package, the package has a size of less than or equal to 30mm×20mm×8mm, and the bottom of the package is provided with an insulating high-temperature resistant adhesive layer.

[0019] Furthermore, the LoRa repeater is configured with LoRa modulation technology with a spreading factor of SF=10, a transmission power of ≤10dBm, and a communication distance covering all temperature measurement points inside a single switch cabinet, supporting simultaneous communication of no less than 10 temperature measurement points.

[0020] Furthermore, it also includes an alarm device, which is used to trigger an audible and visual alarm; the alarm device is connected to the back-end data center signal, and when the temperature data received by the back-end data center exceeds a preset temperature threshold or the temperature change rate is >5℃ / min, the audible and visual alarm is triggered.

[0021] As a preferred embodiment, a notification device is also included, which is used to push SMS notifications. The notification device is connected to the backend data center. When the temperature data received by the backend data center exceeds a preset temperature threshold or the temperature change rate is greater than 5°C / min, the push SMS notification is triggered.

[0022] This invention also discloses a wireless temperature measurement method suitable for low-current busbar switchgear, employing the wireless temperature measurement system for low-current busbar switchgear described above, and including the following steps:

[0023] S1. Self-powered start-up;

[0024] A thermoelectric generator is installed at the heating point of the low-current bus. The thermoelectric generator is attached to the surface of the low-current bus via a heat-conducting base. It generates electrical energy by utilizing the temperature difference between the bus and the environment. The electrical energy is then regulated by an energy storage device to power the temperature measurement module.

[0025] S2. Temperature acquisition and signal conversion;

[0026] A platinum resistance sensor collects the temperature of the low-current bus, and an infrared auxiliary sensor collects the ambient temperature around the low-current bus. The collected low-current bus temperature and ambient temperature are simultaneously transmitted to a dual-channel AD conversion chip, which converts the two analog signals into digital signals that can be processed later.

[0027] S3. Dynamic calibration;

[0028] The bus temperature digital signal and ambient temperature digital signal output by the dual-channel AD conversion chip are synchronously transmitted to the data processing module. Combined with the real-time bus current value collected by the ammeter, the bus temperature digital signal is corrected by a preset temperature compensation model to obtain the calibrated real bus temperature data.

[0029] S4. Data transmission;

[0030] The calibrated bus actual temperature data is packaged and transmitted to the LoRa repeater, and then transmitted by the LoRa repeater to the back-end data center;

[0031] S5. Data processing;

[0032] The back-end data center plots the temperature rise curve based on the calibrated actual bus temperature data.

[0033] Furthermore, it also includes an alarm device. The back-end data center compares the real-time temperature and temperature rise rate with preset thresholds. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5°C / min, the back-end data center triggers the audible and visual alarm of the alarm device.

[0034] As a preferred approach, a notification device is also included. The back-end data center compares the real-time temperature and temperature rise rate with a preset threshold. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5°C / min, the notification device pushes an SMS notification to the designated terminal.

[0035] Furthermore, the LoRa repeater is configured with LoRa modulation technology with a spreading factor of SF=10, a transmission power of ≤10dBm, and a communication distance covering more than 10 temperature measurement points inside a single switch cabinet.

[0036] The beneficial effects of this invention are as follows: It obtains electrical energy through a temperature difference self-powered module, combines dual temperature sensors and a dynamic calibration algorithm to achieve temperature acquisition, uses a LoRa repeater for low-power communication data transmission, and completes anomaly early warning through a background data center. This invention requires no external power supply or battery replacement, achieves temperature measurement accuracy of ±0.5℃ in low-current environments below 5A, and can effectively monitor abnormal temperature rises in key areas such as busbar joints and cable connection points. It is suitable for low-load power scenarios such as power distribution rooms and industrial control cabinets. Simultaneously, it is equipped with alarm and notification devices, employing a dual-criteria early warning mechanism of "temperature threshold + temperature rise rate" to achieve dual early warning both locally and remotely. It is not limited by whether someone is on-site, ensuring that maintenance personnel can receive abnormal information immediately, promptly address overheating hazards, prevent the expansion of faults such as busbar burning and insulation aging, and significantly improve the operational safety of low-current busbar switchgear. The back-end data center receives the calibrated busbar real temperature data and plots the temperature rise curve, which can intuitively reflect the busbar temperature change trend. This makes it easy for maintenance personnel to monitor the busbar operating status in real time and analyze the trend, detect potential overheating hazards in advance, and realize the prediction and early handling of faults. At the same time, the back-end centrally manages all temperature measurement nodes, which facilitates unified maintenance, threshold adjustment and data traceability, and provides convenience for the operation and maintenance management of switchgear.

[0037] In summary, this invention addresses industry pain points such as low heating of low-current busbars, large errors in traditional temperature measurement, difficulties in power supply, and complex installation. Through the design of technologies such as self-powered operation without resistance, dual-path temperature measurement calibration, miniaturized integration, wireless transmission, and dual early warning, it achieves high-precision, passive, and long-term online temperature measurement of low-current busbar switchgear, thereby improving the safety and reliability of equipment operation and reducing maintenance costs. Attached Figure Description

[0038] Figure 1 : A schematic diagram of the system architecture of this invention;

[0039] Figure 2 : A schematic diagram of the internal structure of the thermoelectric self-generating module and the temperature measuring module integrated in the package;

[0040] Figure 3 : A schematic diagram of the method flow of the present invention;

[0041] Reference numerals: 1-Self-powered temperature measurement module; 11-Temperature difference self-powered module; 111-Bismuth telluride thermoelectric chip; 112-Aluminum alloy heat sink fins; 114-Energy storage device; 115-Heat-conducting base; 12-Temperature measurement module; 121-Platinum resistance sensor; 122-Infrared auxiliary sensor; 2-Packaging body; 21-Insulating high-temperature resistant adhesive layer; 3-Data processing module; 4-LoRa repeater; 5-Back-end data center; 6-Alarm device; 7-Notification device. Detailed Implementation

[0042] The present invention will be further described below.

[0043] This invention provides a wireless temperature measurement system suitable for low-current busbar switchgear, mainly used for wireless temperature measurement of switchgear, including a self-powered temperature measurement module 1, a data processing module 3, a LoRa repeater 4, and a back-end data center 5; the self-powered temperature measurement module 1 includes a thermoelectric self-powered module 11 and a temperature measurement module 12; the thermoelectric self-powered module 11 includes a thermoelectric generator, a DC-DC converter, and an energy storage device 114 connected in sequence, and the thermoelectric generator is also provided with a heat-conducting base 115, which is attached to the low-current busbar; the temperature measurement module 12 includes a platinum resistance sensor 121, an infrared auxiliary sensor 122, and a dual-channel... The AD conversion chip includes a platinum resistance sensor 121 mounted on a low-current busbar and an infrared auxiliary sensor 122 mounted on the outside of the switchgear. Both the platinum resistance sensor 121 and the infrared auxiliary sensor 122 are communicatively connected to the dual-channel AD conversion chip and electrically connected to the energy storage device 114. The data processing module 3 is signal-connected to the dual-channel AD conversion chip and is also connected to an ammeter for acquiring real-time busbar current values. The data processing module 3 incorporates a temperature compensation model for correcting the acquired temperature data. The calculation formula for the temperature compensation model is as follows:

[0044]

[0045] Among them, I 母线 —Real-time bus current, T 环境 —Ambient temperature collected by the infrared auxiliary sensor; T 采集 —Bus temperature collected by platinum resistance sensor;

[0046] The LoRa repeater 4 is installed on the top of the switch cabinet. The LoRa repeater 4 is communicatively connected to the data processing module 3 and the back-end data center 5. The back-end data center 5 is used to receive the actual bus temperature data obtained by the temperature compensation model and plot the temperature rise curve.

[0047] The core of this invention is to construct a complete temperature measurement system that integrates "passive power supply, dual-path temperature measurement, dynamic calibration, wireless transmission, and centralized management," addressing the core pain points of low-current bus temperature measurement power supply difficulties and low accuracy. Its wireless temperature measurement system mainly consists of a temperature difference self-powered module 11, a temperature measurement module 12, a data processing module 3, a LoRa repeater 4, and a back-end data center 5. The modules work together to form a complete temperature measurement link, while an alarm device 6 and a notification device 7 are added to improve the early warning system. The corresponding temperature measurement methods form a closed-loop process.

[0048] The self-powered temperature difference module 11 of this invention is the core of the passive operation of the system. The self-powered temperature difference module 11 includes a thermoelectric generator, a DC-DC converter, and an energy storage device 114 connected in sequence. The thermoelectric generator is also provided with a heat-conducting base 115, which is attached to the low-current bus. By using the self-powered temperature difference module 11, electrical energy is generated by the temperature difference between the low-current bus and the environment. After being regulated by the DC-DC converter, the energy is stored by the energy storage device 114 to power the entire system. There is no need for an external power supply or periodic battery replacement. This completely solves the problems of inconvenient power supply and high maintenance costs of traditional temperature measurement systems, and enables the system to operate passively and without maintenance for a long time, which greatly reduces the workload and cost of maintenance.

[0049] The temperature measurement module 12 adopts a dual-channel temperature measurement design using a platinum resistance sensor 121 and an infrared auxiliary sensor 122. The platinum resistance sensor 121 is directly attached to the low-current busbar to collect the busbar's body temperature, while the infrared auxiliary sensor 122 is fixed to the outside of the switchgear to collect the ambient temperature. Both sensors are communicatively connected to a dual-channel AD conversion chip and are powered by the energy storage device 114. This dual-channel acquisition design provides basic data for subsequent temperature calibration, effectively improving the reliability and redundancy of temperature measurement. The ammeter collects the real-time current value of the busbar. The data processing module 3 is signal-connected to the dual-channel AD conversion chip and has a built-in temperature compensation model. The specific calculation formula is as follows:

[0050]

[0051] Among them, I 母线 —Real-time bus current, T 环境 —Ambient temperature collected by the infrared auxiliary sensor; T 采集 —Bus temperature collected by a platinum resistance sensor.

[0052] After receiving the digital signal transmitted by the dual-channel AD conversion chip, the data processing module 3 combines it with the real-time bus current value and uses the compensation model to dynamically correct the bus temperature data. This effectively offsets the interference of ambient temperature and bus current fluctuations on temperature measurement accuracy under low current conditions, significantly improving the temperature measurement accuracy of low-current buses and solving the technical defect of large temperature measurement error in traditional single-sensor systems. The LoRa repeater 4 is fixedly installed on the top of the switchgear as a relay node for data transmission. Its low transmission power meets the low power consumption requirements, matches the temperature difference self-powered system, does not add extra power supply burden, and meets the electromagnetic compatibility requirements of power equipment, so it will not interfere with the normal operation of relay protection, measurement and control equipment in the switchgear. The actual bus temperature data output by data processing module 3 is transmitted wirelessly to LoRa repeater 4. After signal amplification and forwarding by LoRa repeater 4, it is transmitted to the backend data center 5. After receiving the data, the backend data center 5 plots the temperature rise curve, which intuitively reflects the changing trend of bus temperature. This facilitates real-time monitoring and trend analysis of the bus operation status by maintenance personnel, enabling early detection of potential overheating hazards and early fault prediction and handling. At the same time, the backend can centrally manage all temperature measurement nodes, facilitating unified maintenance, threshold adjustment, and data traceability.

[0053] Specifically, the thermoelectric power generation component includes a bismuth telluride thermal power generation chip 111. The hot end of the bismuth telluride thermal power generation chip 111 is attached to the busbar via a heat-conducting base 115. The cold end of the bismuth telluride thermal power generation chip 111 is connected to an aluminum alloy heat sink 112. The aluminum alloy heat sink 112 is located on the top of the energy storage device 114. The bismuth telluride thermal power generation chip 111 is electrically connected to a DC-DC converter. The heat-conducting base 115 is made of aluminum nitride ceramic material. The energy storage device 114 uses a lithium titanate battery.

[0054] The thermoelectric generator uses a bismuth telluride thermoelectric chip 111, which is suitable for low-current bus heating and low-temperature difference conditions. It can still generate electricity stably even with a small temperature difference between the low-current bus and the environment, effectively solving the problem of insufficient power supply from the low-current bus. The hot end of the bismuth telluride thermoelectric chip 111 is tightly attached to the low-current bus via a thermally conductive base 115 made of aluminum nitride ceramic, while the cold end is connected to an aluminum alloy heat sink 112. This structural design enhances the temperature gradient and significantly improves power generation efficiency. 15 combines excellent thermal conductivity and insulation, ensuring efficient heat transfer while avoiding the safety hazard of busbar short circuits; the bismuth telluride thermal power generation chip 111 is electrically connected to the DC-DC converter, which is then electrically connected to the energy storage device 114 made of lithium titanate battery, forming a complete self-powered link. The lithium titanate battery has a long cycle life, good high and low temperature performance, and high safety, and can store excess electrical energy to ensure that the system can still supply power stably when the temperature difference between the busbar and the environment is small, greatly extending the system's maintenance-free cycle.

[0055] To accommodate the limited space within the switchgear and facilitate installation, the temperature difference self-powered module 11 and the temperature measuring module 12 are integrated within a package 2. The package 2 has dimensions of ≤30mm×20mm×8mm, and its bottom is provided with an insulating high-temperature resistant adhesive layer 21. The temperature difference self-powered module 11 and the temperature measuring module 12 are integrated within a miniature package 2 with dimensions ≤30mm×20mm×8mm. The bottom of the package 2 is provided with an insulating high-temperature resistant adhesive layer 21, which can be directly pasted and fixed to the surface of the low-current busbar without the need for additional clamps or drilling. This not only does not damage the busbar structure, but also makes construction convenient and efficient, while ensuring electrical safety and preventing short circuits caused by metal parts contacting the busbar. At the same time, the integrated design reduces discrete components and external wiring, resulting in a more compact structure, stronger vibration resistance, and the ability to adapt to the complex operating environment within the switchgear.

[0056] To ensure the communication distance of LoRa repeater 4 and reduce data packet loss rate, LoRa repeater 4 is configured with LoRa modulation technology with a spreading factor of SF=10 and a transmission power of ≤10dBm. The communication distance covers all temperature measurement points inside a single switch cabinet, supporting simultaneous communication from at least 10 temperature measurement points. This parameter setting, balancing communication distance and anti-interference capability, effectively penetrates the shielding of metal switch cabinets, reduces data packet loss rate, and ensures stable wireless transmission. Furthermore, a single LoRa repeater 4 can cover more than 10 temperature measurement points within a single switch cabinet, simplifying network configuration, reducing system networking costs, and offering strong scalability, allowing for flexible expansion of temperature measurement nodes based on the number of switch cabinets.

[0057] To achieve comprehensive and all-weather safety early warning, this invention adds an alarm device 6 and a notification device 7, both of which are connected to the back-end data center 5. They adopt a dual-criteria early warning mechanism of "temperature threshold and temperature rise rate". When the back-end data center 5 detects that the real-time temperature of the bus exceeds the preset threshold or the temperature change rate is greater than 5℃ / min, it will trigger the operation of the two devices simultaneously. Alarm device 6 uses an audible and visual alarm, installed in a conspicuous location such as the outside of the switchgear door. When triggered, it emits a warning light and alarm sound, which is intuitive and eye-catching, allowing on-site maintenance personnel to quickly locate the faulty switchgear, shortening the fault investigation time, and promptly addressing overheating hazards to prevent the fault from escalating. Notification device 7 uses an SMS module, which can preset multiple maintenance personnel terminal numbers. When triggered, it automatically edits an SMS message containing the faulty switchgear number, temperature measurement point location, real-time temperature, and anomaly type, and pushes it to the preset maintenance personnel terminals. This compensates for the shortcomings of audible and visual alarms, which can only provide on-site warnings, and realizes remote warnings. It is not limited by whether someone is on-site, ensuring that maintenance personnel can receive abnormal information as soon as possible, understand the fault situation in advance, and carry the corresponding tools to handle it, regardless of their location. This improves maintenance efficiency and reduces fault losses. At the same time, SMS notifications can retain abnormal records, which is convenient for post-fault analysis and maintenance review.

[0058] This invention also provides a wireless temperature measurement method suitable for low-current busbar switchgear, applicable to the aforementioned wireless temperature measurement system for low-current busbar switchgear, comprising the following steps:

[0059] S1. Self-powered start-up;

[0060] A thermoelectric generator is installed at the heating point of the low current bus. The thermoelectric generator is attached to the surface of the low current bus through a heat-conducting base 115. It generates electrical energy by utilizing the temperature difference between the bus and the environment. The electrical energy is then regulated by the energy storage device 114 and used to power the temperature measuring module 12.

[0061] S2. Temperature acquisition and signal conversion;

[0062] The platinum resistance sensor 121 collects the temperature of the low current bus, and the infrared auxiliary sensor collects the ambient temperature around the low current bus. The collected low current bus temperature and ambient temperature are simultaneously transmitted to the dual-channel AD conversion chip, which converts the two analog signals into digital signals that can be processed later.

[0063] S3. Dynamic calibration;

[0064] The bus temperature digital signal and ambient temperature digital signal output by the dual-channel AD conversion chip are synchronously transmitted to the data processing module 3. Combined with the real-time bus current value collected by the ammeter, the bus temperature digital signal is corrected by the preset temperature compensation model to obtain the calibrated real bus temperature data.

[0065] S4. Data transmission;

[0066] The calibrated bus actual temperature data is packaged and transmitted to LoRa repeater 4, and then transmitted by LoRa repeater 4 to the background data center 5.

[0067] S5. Data processing;

[0068] The background data center 5 plots the temperature rise curve based on the calibrated busbar real temperature data.

[0069] It also includes an alarm device 6. The back-end data center 5 compares the real-time temperature and temperature rise rate with the preset threshold. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5℃ / min, the back-end data center 5 triggers the audible and visual alarm of the alarm device 6.

[0070] It also includes a notification device 7. The background data center 5 compares the real-time temperature and temperature rise rate with the preset threshold. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5℃ / min, the notification device 7 pushes an SMS notification to the designated terminal.

[0071] Corresponding to the aforementioned wireless temperature measurement system, the wireless temperature measurement method of this invention forms a closed-loop process of "self-powered startup → temperature acquisition and signal conversion → dynamic calibration → data transmission → data processing → anomaly warning". This method is based on the orderly coordination of the structure of each module of the above system. The self-powered startup step provides the energy foundation for the entire method. The electrical energy generated by the thermoelectric generator is regulated by a DC-DC converter, stored in the energy storage device 114, and then transmitted to the temperature measurement module 12 to power it. In the temperature acquisition and signal conversion step, the platinum resistance sensor 121 and the infrared auxiliary sensor 122 respectively acquire the bus temperature and the ambient temperature, and transmit the data through a dual-channel... The analog-to-digital converter chip converts the analog signal into a digital signal, which is then transmitted to the data processing module 3. In the dynamic calibration step, the data processing module 3, combined with the real-time bus current value, corrects the digital bus temperature signal using a temperature compensation model to obtain accurate and true bus temperature data. In the data transmission step, the calibrated true bus temperature data is transmitted to the backend data center 5 via a LoRa repeater 4. The backend then plots a temperature rise curve and performs anomaly detection. The anomaly warning step relies on the signal connection between the backend data center 5 and the alarm device 6 and notification device 7 to simultaneously trigger audible and visual alarms and SMS notifications, completing the entire temperature measurement and warning process. This method features a clear process, rigorous logic, and ease of engineering implementation and batch deployment. Its low-power design perfectly matches the self-powered system, eliminating the need for an external power supply. It is suitable for long-term unattended operation scenarios, significantly reducing maintenance costs. Furthermore, dynamic calibration ensures the reliability of the monitoring data, and the dual warning mechanism enhances the safety of the switchgear operation.

[0072] To ensure the communication distance of LoRa repeater 4 and reduce the data packet loss rate, LoRa repeater 4 is configured with LoRa modulation technology with a spreading factor of SF=10, a transmission power of ≤10dBm, and a communication distance covering all temperature measurement points inside a single switch cabinet, supporting simultaneous communication of no less than 10 temperature measurement points.

[0073] It should be noted that the spread spectrum factor, transmission power, temperature threshold, and temperature rise rate threshold of the LoRa repeater in this embodiment can all be adjusted according to the actual application scenario. Other power generation materials adapted to low temperature difference conditions can also be used for the thermoelectric power generation component. These modifications and improvements do not depart from the design spirit of this invention and should all fall within the protection scope of this invention.

Claims

1. A wireless temperature measurement system suitable for low-current busbar switchgear, characterized in that: It includes a self-powered temperature measurement module (1), a data processing module (3), a LoRa repeater (4), and a back-end data center (5); the self-powered temperature measurement module (1) includes a temperature difference self-powered module (11) and a temperature measurement module (12). The thermoelectric self-powered module (11) includes a thermoelectric generator, a DC-DC converter, and an energy storage device (114) connected in sequence. The thermoelectric generator is also provided with a heat-conducting base (115), which is attached to the low-current bus. The temperature measurement module (12) includes a platinum resistance sensor (121), an infrared auxiliary sensor (122), and a dual-channel AD conversion chip. The platinum resistance sensor (121) is located on the low-current bus, and the infrared auxiliary sensor (122) is located on the outside of the switch cabinet. Both the platinum resistance sensor (121) and the infrared auxiliary sensor (122) are communicatively connected to the dual-channel AD conversion chip, and both the platinum resistance sensor (121) and the infrared auxiliary sensor (122) are electrically connected to the energy storage device (114). The data processing module (3) is connected to the dual-channel AD conversion chip, and is also connected to an ammeter for collecting real-time bus current values; the data processing module (3) has a built-in temperature compensation model for correcting the collected temperature data, and the calculation formula of the temperature compensation model is: ； Among them, I 母线 —Real-time bus current value; T 环境 —Ambient temperature collected by the infrared auxiliary sensor; T 采集 —Bus temperature collected by platinum resistance sensor; The LoRa repeater (4) is installed on the top of the switch cabinet. The LoRa repeater (4) is connected to the data processing module (3) and the back-end data center (5). The background data center (5) receives the actual bus temperature data obtained by the temperature compensation model and plots the temperature rise curve.

2. The wireless temperature measurement system for low-current busbar switchgear as described in claim 1, characterized in that: The thermoelectric power generation component includes a bismuth telluride thermal power generation chip (111). The hot end of the bismuth telluride thermal power generation chip (111) is attached to the busbar through a heat-conducting base (115). The cold end of the bismuth telluride thermal power generation chip (111) is connected to an aluminum alloy heat sink (112). The aluminum alloy heat sink (112) is located on the top of the energy storage device (114). The bismuth telluride thermal power generation chip (111) is electrically connected to a DC-DC converter. The heat-conducting base (115) is made of aluminum nitride ceramic material. The energy storage device (114) uses a lithium titanate battery.

3. The wireless temperature measurement system for low-current busbar switchgear as described in claim 1, characterized in that: The temperature difference self-powered module (11) and the temperature measuring module (12) are integrated in the package (2). The size of the package is less than or equal to 30mm×20mm×8mm. The bottom of the package (2) is provided with an insulating high-temperature resistant adhesive layer (21).

4. The wireless temperature measurement system for low-current busbar switchgear as described in claim 1, characterized in that: The LoRa repeater (4) is configured with LoRa modulation technology with a spreading factor of SF=10, a transmission power of ≤10dBm, and a communication distance covering all temperature measurement points inside a single switch cabinet, supporting simultaneous communication of no less than 10 temperature measurement points.

5. A wireless temperature measurement system suitable for low-current busbar switchgear as described in claim 1, characterized in that: It also includes an alarm device (6), which is used to trigger an audible and visual alarm; the alarm device (6) is connected to the background data center (5) by signal, and when the temperature data received by the background data center (5) exceeds the preset temperature threshold or the temperature change rate is greater than 5℃ / min, the audible and visual alarm is triggered.

6. A wireless temperature measurement system suitable for low-current busbar switchgear as described in claim 1 or 5, characterized in that: It also includes a notification device (7), which is used to push SMS notifications. The notification device (7) is connected to the background data center (5) by signal. When the temperature data received by the background data center (5) exceeds the preset temperature threshold or the temperature change rate is greater than 5℃ / min, it triggers the push of SMS notifications.

7. A wireless temperature measurement method suitable for low-current busbar switchgear, characterized in that: The wireless temperature measurement system for low-current busbar switchgear, as described in any one of claims 1-6, comprises the following steps: S1. Self-powered start-up; A thermoelectric generator is installed at the heating point of the low current bus. The thermoelectric generator is attached to the surface of the low current bus via a heat-conducting base (115). It generates electrical energy by utilizing the temperature difference between the bus and the environment. The electrical energy is regulated by a DC-DC converter and powered by an energy storage device (114) to supply power to the temperature measuring module (12). S2. Temperature acquisition and signal conversion; The platinum resistance sensor (121) collects the low current bus temperature, and the infrared auxiliary sensor (122) collects the ambient temperature around the low current bus. The collected low current bus temperature and ambient temperature are synchronously transmitted to the dual-channel AD conversion chip. The dual-channel AD conversion chip converts the two analog signals into digital signals that can be processed later and transmits them to the data processing module (3). S3. Dynamic calibration; The data processing module (3) corrects the bus temperature digital signal and the ambient temperature digital signal output by the dual-channel AD conversion chip, and combines the real-time bus current value collected by the ammeter with the bus temperature digital signal through the preset temperature compensation model to obtain the calibrated bus real temperature data. S4. Data transmission; The calibrated bus real temperature data is packaged and transmitted to the LoRa repeater (4), and then transmitted by the LoRa repeater (4) to the background data center (5). S5. Data processing; The background data center (5) plots the temperature rise curve based on the calibrated bus actual temperature data.

8. A wireless temperature measurement method for low-current busbar switchgear as described in claim 7, characterized in that: It also includes an alarm device (6). The back-end data center (5) compares the real-time temperature and temperature rise rate with the preset threshold. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5℃ / min, the back-end data center (5) triggers the audible and visual alarm of the alarm device (6).

9. A wireless temperature measurement method for low-current busbar switchgear as described in claim 8, characterized in that: It also includes a notification device (7). The background data center (5) compares the real-time temperature and temperature rise rate with the preset threshold. When the real-time temperature of the bus exceeds the preset temperature threshold, or the temperature change rate is greater than 5℃ / min, the notification device (7) pushes a text message notification to the designated terminal.

10. A wireless temperature measurement method for low-current busbar switchgear according to claim 7, characterized in that: The LoRa repeater (4) is configured with LoRa modulation technology with a spreading factor of SF=10, a transmission power of ≤10dBm, and a communication distance covering all temperature measurement points inside a single switch cabinet, supporting simultaneous communication of no less than 10 temperature measurement points.

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