Synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology

Abstract

The invention discloses a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology, which comprises a temperature detection transmitting unit and a wireless temperature measurement host, and is characterized in that the temperature detection transmitting unit is arranged on a rotor and rotates along with the rotor; the temperature detection transmitting unit and the wireless temperature measurement host carry out data transmission through the LoRa wireless communication module, compared with the prior art, the latest Internet of Things technology is adopted, low-power-consumption and long-distance data transmission is achieved, and meanwhile the system has high anti-interference performance and high data safety.

Description

Technical Field

[0001] The present invention relates to a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology, specifically, a temperature sensor is used to monitor the temperature of the synchronous generator rotor coil in real time, and the collected temperature data is concentrated and transmitted to a wireless temperature measurement host through a LoRa wireless network, so that the real-time temperature of each temperature measurement point of the rotor can be inspected on site, and at the same time, the data is transmitted to a computer monitoring system through an RS485 interface of the wireless temperature measurement host, so that the temperature of each temperature measurement point of the rotor can be monitored in real time in a central control room. Background Art

[0002] Hydroelectric generators are key equipment for converting water energy into electrical energy. Hydroelectric generators use the kinetic energy of the water flow to drive the impeller, which in turn drives the rotor of the generator to convert mechanical energy into electrical energy. This process is the core of hydropower generation. Hydroelectric generators use water resources to generate electricity. It is a clean and renewable form of energy. It reduces dependence on fossil fuels and helps reduce greenhouse gas emissions. Hydroelectric generators play an indispensable role in the modern energy system. They not only provide humans with a continuous and reliable source of electricity, but also play an important role in environmental protection and resource management.

[0003] With the intensified competition in the electricity market and the higher requirements for the safety of power generation equipment, the demand for health monitoring of various components of hydro-turbine generator sets is increasing. Among them, the health monitoring of the two most critical components of hydro-turbine generators: stator and rotor is particularly important. The health detection of the stator is easy to implement, while the rotor is a rotating component. How to transmit the data collected by the sensor is a troublesome problem.

[0004] There are several traditional data transmission paths: one is to transmit weak current signals through micro slip rings, which is currently only seen in laboratories. Due to its complex structure, it is difficult to operate safely for a long time, so it is rarely used in hydropower station turbine generator sets. Another method is to transmit data through Bluetooth technology (2.4GHZ). Bluetooth has a short transmission distance and very poor anti-interference. Even if someone stands between the two devices, it will affect the reception of the signal. Bluetooth consumes a lot of power and requires frequent battery replacement, which cannot meet the requirements of a major overhaul cycle. It is impossible for hydropower station owners to shut down and replace batteries frequently. The passive solution is to obtain power by transforming the voltage in parallel with the magnetic pole excitation power supply. Because the excitation power of the turbine generator is very large and transient processes often occur, the DC-DC transformer switching power supply connected in parallel to the excitation line has a very high probability of burning out, and safety cannot be guaranteed, so it is difficult to use in practice.

[0005] The application (patent) number is: CN201410625481.5. A method for measuring the temperature of a permanent magnet transmission coupling and a generator rotor of a wind turbine generator set. This method embeds a wireless temperature acquisition device inside the permanent magnet transmission mechanism coupling and the generator rotor, receives the temperature signal through the wireless temperature acquisition device located on the ground operating table, and measures the actual temperature of the coupling and the rotor during the transmission operation in real time. The wireless communication module of this temperature measurement method uses the radio frequency chip CC2420, but it may still be affected by electromagnetic interference in certain environments, and the distance of radio frequency technology is short.

[0006] The application (patent) number is: CN202110360431.9, a motor rotor temperature measurement system, a method for detecting the temperature of a motor rotor, and an application. The motor rotor temperature measurement system includes: a temperature measurement part, connected to the motor rotor to be measured; a control part, connected to the temperature measurement part, for receiving and storing temperature data received by the temperature measurement part; a transmission part, connected to the control part; a power supply module, connected to the transmission part, and the power supply module is used to provide power to the control part and the temperature measurement part; by connecting the temperature measurement part to the motor rotor, and transmitting the control signal to the control part through the transmission part, the temperature of the motor rotor during rotation is detected by the control part, and the temperature data is transmitted to the control part for storage. A wireless communication method is used to transmit the temperature measurement signal to the outside, and the communication module adopts a wireless infrared receiver or a wireless radio frequency receiver, but the wireless infrared receiver, infrared technology is directional, the transmitter must be aligned with the receiver, and there must be no obstacles in the middle. The effective distance of infrared technology is generally short, and the radio frequency receiver may still be subject to electromagnetic interference in certain environments, and the distance of radio frequency technology is short.

[0007] The existing generator rotor temperature monitoring technology is difficult to meet the needs of hydropower station owners. Therefore, a low-power, long-distance wireless temperature monitoring solution is urgently needed. Summary of the invention

[0008] The purpose of the present invention is to solve the problems in the prior art and propose a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology. It adopts the latest Internet of Things technology to achieve low power consumption and long-distance data transmission, and at the same time has strong anti-interference and high data security.

[0009] To achieve the above objectives, the present invention proposes a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology, including a temperature detection and transmitting unit and a wireless temperature measurement host. The temperature detection and transmitting unit is arranged on the rotor and rotates with the rotor. The wireless temperature measurement data collection transmitter and the wireless temperature measurement host perform data transmission through the LoRa wireless communication module.

[0010] Preferably, the temperature detection transmitting unit includes a wireless temperature measurement data concentration transmitter and several temperature sensor modules. The temperature sensor module is arranged on the lower insulating pad of the rotor coil and sends the temperature measurement data to the wireless temperature measurement data concentration transmitter arranged on the main shaft through a data line. Then the wireless temperature measurement data concentration transmitter sends the temperature measurement data to the wireless temperature measurement host through a wireless signal.

[0011] Preferably, the wireless temperature measurement host can display temperature data and send the information to a computer monitoring system via an RS485 interface.

[0012] Preferably, the temperature sensor module adopts a high-insulation resin patch Pt100 temperature measuring element, which is in the shape of a rectangular thin sheet. A suitable groove is made near the end of the lower insulating pad of the rotor coil to embed the temperature sensor module, and then it is fixed with epoxy resin. The surface is flush with the lower insulating pad. Because the magnetic poles of the synchronous motor are connected in series, considering the centrifugal force of the rotor and the convenience of wiring, six temperature measuring elements are all arranged on the lower insulating pad. There are six temperature sensor modules, which are evenly or nearly evenly distributed according to the distribution of the magnetic poles. The number of temperature sensor modules can also be increased or decreased according to specific circumstances.

[0013] Preferably, the operating temperature range of the Pt100 temperature measuring element is: -30°C to +300°C, the accuracy is: ±0.1°C, the interface type is: U-shaped terminal or plug, and the lead wire of the Pt100 temperature measuring element adopts a waterproof and oil-proof polytetrafluoroethylene silver-plated anti-interference cable with a metal shielding layer.

[0014] Preferably, the wireless temperature measurement data centralized transmitter includes a data acquisition unit, a LoRa wireless communication module and a power management module, all of which are connected to a central management system.

[0015] Preferably, the data acquisition unit: uses a microcontroller for data processing, and its functions include: initializing the temperature sensor, reading temperature data at regular intervals, handling abnormal situations and threshold judgments; the frequency range selection of the LoRa wireless communication module: China: 470MHz, Europe: 868MHz, the United States: 915MHz; the central management system: uses cloud services or local servers, and the core functions are: receiving, storing and displaying temperature data, generating reports and alarm information; the power management module: uses lithium batteries or DC power supplies, and includes: a DC-DC converter to ensure stable power supply.

[0016] The beneficial effects of the present invention are as follows: 1. Real-time monitoring: it can collect rotor temperature information in real time; 2. Long-distance transmission: using LoRa technology to achieve long-distance, low-power data transmission; 3. High reliability: ensuring the safe operation of the generator through data analysis and alarm mechanism.

[0017] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology of the present invention; Figure 2 This is a schematic diagram of the installation of temperature measuring components; Figure 3 It is a software flow chart.

[0019] In the figure: 10-temperature sensor module, 11-wireless temperature measurement data concentration transmitter, 12-wireless temperature measurement host, 13-computer monitoring system, 14-lower insulating pad. DETAILED DESCRIPTION

[0020] See also Figure 1 , Figure 2 The present invention provides a synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology, including a temperature detection transmitting unit and a wireless temperature measurement host 12. The temperature detection transmitting unit is arranged on the rotor and rotates with the rotor. The temperature detection transmitting unit and the wireless temperature measurement host 12 transmit data through the LoRa wireless communication module.

[0021] The temperature detection transmitting unit includes a wireless temperature measurement data centralized transmitter 11 and a plurality of temperature sensor modules 10. The temperature sensor module 10 is arranged on the lower insulating pad 14 of the rotor coil and sends the temperature measurement data to the wireless temperature measurement data centralized transmitter 11 arranged on the main shaft through a data line. Then the wireless temperature measurement data centralized transmitter 11 sends the temperature measurement data to the wireless temperature measurement host 12 through a wireless signal.

[0022] The wireless temperature measurement host 12 includes functions such as data reception, data display, data storage and RS485 communication, can display temperature data, and send information to the computer monitoring system 13 through the RS485 interface. The wireless temperature measurement host 12 is placed in the temperature measurement brake screen next to the machine, can receive the signal emitted by the wireless temperature measurement data concentration transmitter 11, and display it through the display screen, and also has an RS485 interface to transmit the received data to the computer monitoring system 13, so as to monitor the temperature of the rotor coil at any time in the central control room.

[0023] The temperature sensor module 10 adopts a high-insulation resin patch Pt100 temperature measuring element, which is a rectangular thin sheet with dimensions of: 30mm long × 10mm wide × 2mm high. A suitable groove is made near the end of the lower insulating pad 14 of the rotor coil to embed the temperature sensor module 10, and then it is fixed with epoxy resin, and the surface is flush with the lower insulating pad 14. Because the magnetic poles of the synchronous motor are connected in series, considering the centrifugal force of the rotor and the convenience of wiring, six temperature measuring elements are all arranged on the lower insulating pad 14. There are six temperature sensor modules 10, which are evenly distributed or nearly evenly distributed according to the distribution of the magnetic poles. The number of temperature sensor modules 10 can also be increased or decreased according to specific circumstances. Up to 200 temperature measurement points can be collected simultaneously.

[0024] The Pt100 temperature measuring element can be routed in the same way as the excitation line, fixed under the wire clamp, and then connected to the reserved terminal of the wireless temperature measurement data concentration transmitter 11. The wireless temperature measurement data concentration transmitter 11 processes and encrypts the temperature data and transmits it through the LoRa communication module.

[0025] The specific technical parameters are as follows: Hardware design: Temperature sensor module: Select a suitable temperature sensor. The present invention selects Pt100 temperature measuring element and ensures that it has: operating temperature range: -30℃ to +300℃, accuracy: ±0.1℃, interface type: U-shaped terminal or plug, the lead of Pt100 temperature measuring element adopts waterproof and oil-proof polytetrafluoroethylene silver-plated anti-interference cable with metal shielding layer, which is mature, reliable and easy to embed.

[0026] Data acquisition unit: uses a microcontroller for data processing, and its functions include: initializing the temperature sensor, reading temperature data at regular intervals, handling abnormal situations and threshold judgment.

[0027] Abnormal detection mechanism: preset temperature threshold. This generator rotor temperature measurement project needs to set high and low thresholds. When the temperature exceeds these ranges, it is immediately marked as abnormal. The generator rotor is generally F-class insulation, but it is assessed according to Class B, that is, the temperature rise is 80K. Considering the maximum ambient temperature of 40 degrees Celsius, the high threshold of the alarm temperature is set to 120 degrees Celsius and the low threshold is set to minus 20 degrees Celsius. That is, when the rotor coil temperature is monitored to be greater than or equal to 120 degrees Celsius, or less than or equal to minus 20 degrees Celsius, a temperature alarm signal is sent to the integrated automation system. The on-duty personnel can see the alarm signal in the central control room and record it in the log file.

[0028] LoRa wireless communication module: Use LoRa communication module, frequency range selection: 470MHz (China) / 868MHz (Europe) / 915MHz (USA), select the corresponding frequency according to the project location, select the appropriate transmission distance and power consumption characteristics, and ensure stable operation in complex environments.

[0029] Data transmission: The data collected by the data acquisition unit is packaged into messages suitable for LoRa transmission format, including temperature value and timestamp.

[0030] Retransmission mechanism: Set the retransmission strategy. When data transmission fails, it will automatically resend to ensure that the data is fully delivered to the wireless temperature measurement host.

[0031] Power management module: Select a suitable power solution, this solution is a lithium battery, and includes: DC-DC converter to ensure stable power supply.

[0032] Intelligent power consumption adjustment: Dynamically adjust the power consumption of each component of the system according to different working modes (such as standby, active, and sleep). For example, when not in operation, switch the sensor and communication module to low power mode. Time scheduling: According to the needs of temperature monitoring, set the time interval for regularly reading sensor data to reduce unnecessary energy consumption.

[0033] Adjustment of data transmission frequency: Under normal circumstances, the frequency of data transmission can be reduced. When anomalies or rapid changes are detected, the frequency of data transmission can be increased to ensure that information is updated in a timely manner. This method can effectively reduce energy consumption during communication.

[0034] Central management system: A local server is used, and its core functions are: receiving, storing and displaying temperature data, and generating reports and alarm information.

[0035] Real-time data reception: Data parsing: Parse the data packets received from the LoRa module and extract temperature values ​​and related information.

[0036] Data storage and processing: Database storage: The received data is stored in the database and organized in time series for subsequent query and analysis.

[0037] Alarm system: sends alarm signals to the central management system. If the temperature reaches the alarm temperature, an email will be sent to the designated mailbox and a pop-up window will be displayed to remind the on-duty personnel.

[0038] Event Recording: The time, temperature value and status of abnormal occurrence are recorded in the internal memory for subsequent analysis and tracking.

[0039] Software Design: Embedded software: Arduino IDE (Chinese name: Arduino Integrated Development Environment, which is a software tool for programming, compiling and uploading code to Arduino microcontroller boards. It provides a simple and easy-to-use interface that enables developers to write, edit and debug code using the Arduino programming language (based on C / C++)) is used for development. The main functions include: device initialization, regular reading and sending of temperature data, abnormal state processing, regular calibration of temperature sensors, implementation of data encryption measures to ensure data transmission security, setting of reasonable alarm mechanisms to reduce false alarms and missed alarms, see attached Figure 3 : Software flow chart.

[0040] Server-side software: The back-end application is developed using Python, and the database is MySQL. The functions include: data reception and analysis, real-time data display and historical data query, and alarm notification function.

[0041] The present invention realizes real-time and reliable temperature monitoring by integrating advanced sensor technology and wireless communication technology, and can be extended from hydro-turbine generators to general generators, or other general machines with rotating parts that need to measure the temperature of the rotating parts.

[0042] The present invention adopts the latest Internet of Things technology, can realize low power consumption, long-distance data transmission, has strong anti-interference ability, and has extremely high data security. The present invention solves the contradiction between power consumption and transmission distance. Generally, low power consumption means short transmission distance, and high power consumption means long transmission distance. This technology solves the technical problem of longer transmission distance than other wireless methods under the same power consumption conditions, and achieves the effect of taking both low power consumption and long distance into account. The battery carried by the wireless temperature measurement data concentration transmitter 11 can theoretically be used for about ten years, meeting the requirement of one overhaul cycle.

[0043] The collected temperature data is centralized and transmitted to the wireless temperature measurement host through the LoRa wireless network. The real-time temperature of each temperature measurement point of the rotor can be inspected on-site. At the same time, the data is transmitted to the computer monitoring system through the RS485 interface of the wireless temperature measurement host. The temperature of each temperature measurement point of the rotor can be monitored in real time in the central control room.

[0044] The system uses a high-insulation resin patch Pt100 temperature measuring element in the shape of a rectangular thin sheet, which is easier to place and provides a larger fitting area. Six temperature measuring elements are usually configured, and the number can also be adjusted according to actual conditions. In addition, the wireless temperature measurement data concentration transmitter 11 can collect up to 200 temperature measurement points at the same time, and process and encrypt the temperature data. The signal is transmitted through the LoRa module. The wireless temperature measurement host 12 is located on-site and can receive signals and display data. It also has an RS485 interface to send information to the computer monitoring system 13, which is convenient for real-time monitoring of the rotor coil temperature in the central control room. In summary, the present invention significantly improves the efficiency and reliability of generator temperature monitoring and provides important guarantees for the safe operation of power generation equipment.

[0045] The system can collect rotor coil temperature information in real time.

[0046] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology, comprising a temperature detection transmitting unit and a wireless temperature measurement host (12), characterized in that: The temperature detection and transmission unit is arranged on the rotor and rotates along with the rotor. Data is transmitted between the temperature detection and transmission unit and the wireless temperature measurement host (12) via a LoRa wireless communication module.

2. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 1, characterized in that: The temperature detection and transmission unit comprises a wireless temperature measurement data concentration transmitter (11) and a plurality of temperature sensor modules (10); the temperature sensor module (10) is arranged on a lower insulating pad (14) of the rotor coil and transmits temperature measurement data to a wireless temperature measurement data concentration transmitter (11) arranged on the main shaft via a data line; and then the wireless temperature measurement data concentration transmitter (11) transmits the temperature measurement data to a wireless temperature measurement host (12) via a wireless signal.

3. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 2, characterized in that: The wireless temperature measurement host (12) can display temperature data and send the information to a computer monitoring system (13) via an RS485 interface.

4. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 2, characterized in that: The temperature sensor module (10) adopts a high-insulation resin patch Pt100 temperature measuring element, which is in the shape of a rectangular thin sheet. A suitable groove is made near the end of the lower insulating pad (14) of the rotor coil to embed the temperature sensor module (10), and then it is fixed with epoxy resin. The surface is flush with the lower insulating pad (14). Because the magnetic poles of the synchronous motor are connected in series, considering the centrifugal force of the rotor and the convenience of wiring, six temperature measuring elements are all arranged on the lower insulating pad (14). The number of temperature sensor modules (10) is six, and they are evenly distributed or nearly evenly distributed according to the distribution of magnetic poles. The number of temperature sensor modules (10) can also be increased or decreased according to specific circumstances.

5. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 4, characterized in that: The operating temperature range of the Pt100 temperature measuring element is: -30°C to +300°C, the accuracy is: ±0.1°C, the interface type is: U-shaped terminal or plug, and the lead wire of the Pt100 temperature measuring element adopts a waterproof and oil-proof polytetrafluoroethylene silver-plated anti-interference cable with a metal shielding layer.

6. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 2, characterized in that: The wireless temperature measurement data centralized transmitter (11) comprises a data acquisition unit, a LoRa wireless communication module and a power management module, all of which are connected to a central management system.

7. A synchronous generator rotor temperature monitoring system based on LoRa wireless transmission technology as claimed in claim 6, characterized in that: The data acquisition unit: uses a microcontroller for data processing, and its functions include: initializing the temperature sensor, reading temperature data at regular intervals, handling abnormal situations and threshold judgments; the frequency range selection of the LoRa wireless communication module: China: 470MHz, Europe: 868MHz, the United States: 915MHz; the central management system: uses cloud services or local servers, and its core functions are: receiving, storing and displaying temperature data, generating reports and alarm information; the power management module: uses lithium batteries or DC power supplies, and includes: a DC-DC converter to ensure stable power supply.

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