Summary: Proper application of electrical fire systems significantly reduces the occurrence of electrical fires within buildings, while also ensuring safety and quality. With the advancement of related technologies in our country, an increasing number of complex electrical technologies and equipment are being applied to internal building circuits, which raises the probability of electrical fires and has a profoundly negative impact on the positive role of buildings and the safety of occupants. The application of LoRa wireless communication technology in electrical fire monitoring systems can significantly reduce the occurrence of electrical fires, achieving the goal of preventing such fires. This wireless communication technology has a long transmission distance, good wall-penetrating capabilities, and due to its low power consumption, it can be effectively used in electrical fire monitoring systems. Therefore, this article mainly starts from the composition, principles, and internal hardware and software design of electrical fire systems, further explaining the design measures for electrical fire monitoring systems.
Keywords: LoRa; Wireless Communication Technology; Electrical Fire Monitoring System
I. Introduction
With the advancement of science and technology in our country, the electrical wiring inside buildings has become increasingly complex, and the complexity of the equipment within the electrical circuits has significantly increased as well. On one hand, this complexity brings convenience to residential and production activities. On the other hand, it also markedly increases the likelihood of electrical fires. Therefore, the application of electrical fire monitoring systems is crucial. These systems can monitor the temperature, leakage, and leakage current within the electrical circuits, thereby providing early warnings for potential fire hazards. The communication technology used in traditional electrical fire monitoring systems, primarily CAN bus transmission, currently faces challenges such as difficult wiring, high construction costs, and limited hardware quality in the context of complex electrical circuits. Thus, during the subsequent development of electrical fire monitoring systems, it is essential to prioritize wireless communication technology and communication distance requirements. By doing so, the operational quality of the electrical fire monitoring systems can be enhanced, and the probability of electrical fires can be reduced.
Section II: Composition and Principle of Electrical Fire Monitoring System
The electrical fire monitoring system based on LoRa wireless communication technology primarily consists of temperature sensors, leakage current sensors, electrical fire detectors, wireless transmission systems, and the central monitoring system. The main application principle of this electrical fire system is that if there are short circuits or leakage phenomena within the electrical lines, the fire detectors can collect data on temperature and leakage current through the temperature sensors and current sensors. After processing the data, it is transmitted to the central monitoring system. If the temperature or leakage current of the lines exceeds the system's pre-set warning thresholds, the main control chip in the detector can transmit the alarm information to the central system and display the alarm values in real-time. During the design process of the electrical fire monitoring system, it is advisable to install high-quality wireless transmitter chips both inside the detectors and in the central monitoring system. This allows the detectors to also use LoRa wireless communication technology to transmit alarm information to on-duty personnel and clearly display the warning location and data, thereby laying a solid foundation for the personnel to implement effective control measures. Moreover, in the context of China's development of information technology and the internet, the application of big data technology and intelligent control equipment in electrical fire monitoring systems can be realized. Through the use of big data technology, data collection and comprehensive analysis can be conducted on parts that frequently exceed warning thresholds, enabling on-duty personnel to make comprehensive considerations on the lifespan and quality of the equipment through data analysis. This ensures timely replacement and maintenance of equipment that does not meet monitoring requirements, thus improving the operational quality of the electrical fire monitoring system and effectively reducing the probability of electrical fires. The application of intelligent equipment in electrical fire monitoring systems ensures effective intelligent processing of data anomalies, thereby genuinely enhancing the application quality and value of the electrical fire monitoring system.
Section 3: Internal Hardware Design Measures for Electrical Fire Monitoring System
(1) Microcontroller Unit
During the hardware design process of electrical fire monitoring systems, the main content includes microcontroller units, signal acquisition paths, communication interfaces, and wireless communication circuits. The primary goal of these hardware devices is to ensure accurate collection and timely transmission of data signals to the main system of the electrical fire monitoring system, thereby reducing the probability of electrical fires and mitigating the negative impacts on production and daily life. When designing the microcontroller units for the electrical fire monitoring system, the main choice is a 32-bit microcontroller based on the ARM Cortex-M core, featuring a 64KB internal system memory, which boasts high-speed operating memory to achieve the goal of rapid data transmission, and can also store certain early warning information. The working voltage of this chip is 2-6V and it can operate below 85°C, making it less demanding in terms of working environment, with low power consumption, fast processing speed, and high stability due to its simple structure. Designers can use this microcontroller unit to set different control modes according to the actual needs of daily life and work, thus meeting the diverse working requirements of the electrical fire detection monitoring system. However, there are certain drawbacks to the application of this microcontroller unit, such as the inability to achieve long-term data storage. Therefore, during the data collection and transmission process using this microcontroller unit, technicians can set up certain information storage units around the microcontroller unit to better utilize the positive effects of data anomaly monitoring and the operation of the electrical fire monitoring system. In the information storage units set up, a regular data cleaning mode should be set to effectively extend the lifespan of the storage units, typically set to clean every three months or half a year.
Signal Collection Circuit
The signal acquisition circuit primarily includes signal sampling loops, operational amplifiers, reference power supplies, voltage followers, and signal filtering circuits. Different circuits operate in various modes and have distinct objectives. For instance, the temperature sensing sampling loop circuit's main function is to measure the internal circuit's operating temperature through circuit design, transmitting the temperature data to the microcontroller unit to enhance its temperature control and early warning capabilities. The current sensor primarily monitors short-circuit or leakage currents in real-time, transmitting the monitored data to the signal acquisition circuit, which then swiftly forwards abnormal data to the main control unit to achieve timely early warning. The specific operational mode involves forming a sampling loop with voltage divider resistors, switching transistors, and temperature sensors, followed by the voltage follower implementing buffering and isolation levels. This not only achieves high input resistance and low output resistance but also ensures that the circuits between stages do not interfere with each other, while also reducing the interference of voltage on the temperature signal acquisition, positively impacting the accuracy of data collection and transmission. During data collection, the microcontroller unit controls the switching transistor to allow the voltage signal generated by the temperature sensor to directly enter the filtering circuit. After reducing interference and amplification, the signal is connected to the microcontroller unit for data processing, effectively monitoring the temperature. The working principle of the signal acquisition circuit is to collect information technology, filter data according to predefined operational modes, transmit abnormal data using amplification, and reduce interference from external factors during transmission to ensure the accuracy and reliability of the data received by the microcontroller unit. This maximizes the application advantages of data, reduces the computational space occupied during data collection, and improves the quality and efficiency of the microcontroller unit's control. In addition to using temperature-sensing electrical fire detection sensors, during system design, technicians can also employ arc-sensing electronic fire detection sensors. These sensors prevent fires caused by arc energy and provide comprehensive monitoring of arcs. When using these sensors, technicians can install them at the end of power distribution lines, effectively enhancing arc detection and reducing the probability of fire incidents. Currently, the quality and level of arc-sensing electrical fire detectors in China are relatively low, failing to meet the fire prevention requirements of most buildings. Therefore, when selecting arc-sensing electrical fire detectors, the introduction of detection methods and sensors can improve the quality of arc detection, strengthen auxiliary monitoring, and ensure the effective operation of arc-sensing electrical fire detection sensors.
(3) Communication Interface
Data processed by the microcontroller unit is transmitted through communication interfaces to wireless communication devices for data transfer. During the design of communication interfaces, attention should be paid to the connection between the wireless communication devices and the microcontroller unit, and to the design of impedance matching functionality, which can effectively reduce and eliminate signal reflections during data transmission. For instance, pins can be set as reset pins to initialize parameters, ensuring that low level is effective. A good synchronous serial interface should also be established to fully ensure the quality and efficiency of data transmission between the wireless communication devices and the microcontroller unit. The design process of the communication interface mainly consists of the chip resistor array and the connection part between the wireless communication and control units. Therefore, the application of the communication interface is not only for data transmission but also for eliminating adverse effects of external factors on data. The use of the chip resistor array can effectively reduce high-frequency signal reflections, lower data transmission distortion, and better achieve the goal of data transmission between the microcontroller unit and the wireless communication circuit.
(4) Wireless Communication
The design of wireless communication circuits for electrical fire monitoring systems can be divided into transmitting and receiving circuits. Communication between the fire detection devices and the main monitoring system utilizes LoRa-based wireless data transmission technology. Compared to wired communication circuits, wireless communication circuits have higher requirements for data transmission quality due to the greater impact of adverse factors during wireless data transmission. Negative effects on data transmission can lead to misjudgments by on-duty personnel about the equipment's status, ultimately increasing the probability of electrical fires and negatively affecting the quality of their work. When selecting data transceivers, attention should be given to integration, low power consumption, and multi-frequency bands, which can achieve long-distance communication goals while reducing external interference during transmission, ensuring data quality and efficiency. The crystal oscillator circuit provides timing signals to the system, forming a transceiving circuit through dual-matching loop configurations, thereby enhancing the anti-interference ability and reliability of wireless communication. During the design of the transmitting circuit, data must be filtered to reduce interference from external high-frequency signals, lowering the signal-to-noise ratio. The C28 and L8 form a series resonant circuit, while additional resistors form two parallel resonant circuits, allowing for adjustment of internal electronic component parameters based on different communication frequencies during information transmission, ensuring optimal data transmission. In the design of the receiving circuit, emphasis should be placed on filtering functions for communication frequency signals, converting input wireless signals into sound signals for transmission on the medium surface, and outputting them as wireless signals for reception and transmission. During the design process, the SX1278 transmitter chip can be used, which boasts high integration, low power consumption, multiple frequency bands, and the ability to achieve long-distance data transmission tasks while maintaining strong anti-interference capabilities. Additionally, this chip has high sensitivity, meeting the requirements of most electrical fire monitoring systems for operation and data transmission. During the use of this chip, attention should be given to the application of complementary equipment to ensure stable power supply, allowing the chip to fully exert its positive effects and improve the anti-interference and stability of data transmission.
Four: Internal Software Design Measures for Electrical Fire Monitoring System
(1) Data Collection Software Design
The design goal of the data collection software is to enable hardware devices to collect data. Currently, there are relatively many programming languages that can be applied in data collection software design, such as C language, Java, and web scraping languages. Generally, C language can better meet the requirements of electrical fire monitoring system software design. During the operation of the electrical fire monitoring system, the data collection software can affect devices such as temperature sensors, current sensors, and electrical fire detectors. It collects relevant data and signals through sensors, and the data collection software should have good data storage capabilities. After power-on, the software should first perform initialization operations, adjusting relevant data and parameters to the optimal data collection state, such as resetting the microcontroller and the detector. Additionally, the screen should be cleared. After initialization, send start commands to various sensors. Once the sensors collect the relevant data, compare it with the preset warning values of the detectors. If it does not exceed the relevant thresholds, repeat the data collection and comparison process. If it exceeds the threshold, an alarm should be triggered, displaying the current values, and uploading the relevant data. During the data upload process, data捆绑 can be used to send data, significantly reducing the data transmission volume and having a very positive impact on the reception and use of data. In the overall software design process, it should be ensured that the software can accurately monitor current information. In addition to hardware facilities, technicians can also set data detection at the software level, checking the same data packets sent at the same time at least three times. This method can effectively improve the accuracy of software alarm operations, play a positive role in reducing the failure of electrical fire detection systems, and is also of great significance in improving the application quality of electrical fire monitoring systems.
(2) Data Transmission Software Design
Data transfer software should be designed with three operating modes: wake, sleep, and normal. The sleep mode corresponds to the mode before the data collection software begins operation, while wake and normal modes are triggered when related data information exceeds the preset threshold. By selecting the corresponding mode through specific instructions stored in the software, the data transfer software should initialize timers and system time to ensure synchronization with the data collection software. After selecting the operating mode for work parameters, the data is transmitted wirelessly, and the software enters a sleep period after each successful transmission, significantly reducing power consumption. The design objectives of the data transfer software primarily focus on three aspects: the quality, speed, and application of data transmission. In the design process, besides ensuring the application quality of the data transfer software through register settings, data encryption/decryption, or bundling and sub-packaging modes can be set at both ends of the data transfer software to improve data integrity and quality, as well as enhance transmission speed, playing a positive role in meeting the data transfer goals. Additionally, there may be issues with the operating modes not matching the data collection mode during software operation, so a well-designed software self-start mode should be set to restart promptly when discrepancies are detected, effectively improving the matching degree between the data transfer software and the data collection software, ensuring the stable and high-quality operation of the overall electrical fire monitoring system.
(3) Monitoring System Software Design
The design team should ensure a robust design for the monitoring software and main system, allowing both the transmission and reception of data using LoRa technology via customizable communication protocols, as well as direct data reception and transmission through LoRa technology. For instance, the monitoring host can utilize modular design to ensure that alarm and fault information are displayed in real-time on the monitoring screen. The human-machine interface should incorporate a touch screen to enhance the interaction between staff and the monitoring system, facilitating smooth setup, entry, and exit functions. Additionally, the design team can set up portable electrical fire monitoring systems, which can promptly alert staff on information terminals if monitored parameters exceed thresholds during system operation, thereby actively contributing to the effectiveness of the electrical fire monitoring system. The main monitoring system, beyond supervising and transmitting alarm information and featuring alarm functions, should also possess excellent verification capabilities. By adjusting alarm thresholds based on historical data records, it ensures that these thresholds remain within a reasonable range, effectively enhancing the system's predictive capabilities for electrical fires and significantly improving the work quality and efficiency of the electrical fire monitoring system. Since implementing big data technology within the electrical fire monitoring system is challenging, it should be set up in the main monitoring system or portable management devices for staff. Big data technology can then be used for large-scale data analysis and calculations of abnormal data, such as detecting excessive temperatures at a particular location in the electrical fire monitoring system. After big data analysis, if it's found that this location frequently experiences overheating, it indicates that traditional electrical wiring may no longer meet safety standards. Big data technology can then promptly convey the analysis to on-duty management staff, who can replace the electrical wiring after inspecting the location. This significantly reduces the likelihood of electrical fires and positively promotes the application quality and efficiency of the electrical fire monitoring system.
(4) Wireless Communication
Design Considerations for Electrical Fire Monitoring Systems: Firstly, it is crucial to avoid any negative impact on residents' normal lives due to the application of the monitoring system. Therefore, technicians should treat the overall fire warning and alarm system as an independent subsystem during the design process of a wireless communication-based electrical fire monitoring system, which also aims to minimize interference factors in wireless communication signal transmission. The electronic signals emitted by the electrical fire monitoring system can only indicate potential hazards within the electrical system, not directly determine the occurrence of an electrical fire. Thus, during the design phase, the electrical monitoring system should be integrated with the automatic fire alarm system to achieve the early warning goal while assisting staff or residents in properly handling fire situations, enhancing the quality and efficiency of fire prevention efforts. When the electrical fire monitoring system alarms, it is essential to ensure a stable power supply; otherwise, residents' lives may be affected due to false triggers. Therefore, the stable operation of both wireless communication and electrical fire monitoring systems must be guaranteed. Secondly, during the design of the wireless communication electrical fire monitoring system, attention should be given to the rational application of protective devices. To ensure that wireless communication devices can play a positive role during both fire and early warning situations, they should be protected, which includes sufficient protection of wireless communication interfaces, microcontrollers, and data transmission modules, with insulating, waterproof, and fire-resistant materials placed externally. This ensures that wireless communication functions can operate normally even under harsh conditions, effectively improving the quality and efficiency of electrical fire early warnings, enhancing the stability of wireless communication, and positively impacting factors that may affect signal transmission. Lastly, a well-designed emergency response software function should be set up. This software primarily serves to address faults in wireless communication devices or microcontrollers, ensuring that software and hardware equipment can be restarted promptly. The software should achieve this by disconnecting the communication between sensors and related equipment, thereby reducing the likelihood of abnormal or erroneous phenomena upon restart. Considering these precautions can effectively improve the application quality of electrical fire systems, playing a highly positive role in enhancing building user experience, ensuring residents' health and safety, and maintaining their normal lifestyle rhythm.
Ankoray Electrical Fire Monitoring System
(1) Overview
The Acre1-6000 Electrical Fire Monitoring System is a fully digital, independently-operating system developed by Ankoray Electric Co., Ltd. in accordance with the current national codes and standards. It has passed the fire product test certification by the National Fire Product Quality Supervision and Inspection Center and all have passed stringent EMC electromagnetic compatibility tests, ensuring safe and normal operation of the series in low-voltage distribution systems. The system is now in mass production and widely used across the country. It achieves early prevention and alarm of electrical fires through the collection and monitoring of residual current, overcurrent, overvoltage, temperature, and fault arc signals. It can also disconnect over-standard distribution circuits detected with residual current, temperature, and fault arc, if necessary. Additionally, it can meet user requirements for data exchange and sharing with the AcreIEMS Enterprise Microgrid Management Cloud Platform or fire automatic alarm systems.
Application Scenarios
Suitable for intelligent buildings, high-rise apartments, hotels, restaurants, commercial buildings, industrial and mining enterprises, key fire prevention units, as well as the oil and petrochemical, cultural and educational, healthcare, financial, and telecommunications sectors.
(3) System Architecture
(4) System Functionality
The monitoring equipment can receive residual current and temperature information from multiple detectors. When an alarm is triggered, it emits both audio and visual alarm signals. Simultaneously, the red "ALARM" indicator light on the device illuminates, the display indicates the location and type of the alarm, records the alarm time, and the audio-visual alarm persists until the "RESET" button on the device or the "RESET" key on the touch screen remotely resets the detector. The audio alarm signal can also be manually silenced using the "Mute" key on the touch screen.
When the monitored loop alarms, the control output relay closes to control the protected circuit or other equipment. Once the alarm is cleared, the control output relay releases.
Communication Fault Alarm: In the event of a communication failure between monitoring equipment and any connected detector, or if the detector itself fails, the corresponding detector on the monitoring screen will display a fault alert, along with the yellow "FAULT" indicator light on the device and an alarm sound. Power Fault Alarm: Should there be a failure in the main power supply or the backup power supply, the monitoring equipment will also emit an audible and visual alarm signal and display fault information. Users can access the relevant interface to view detailed information and deactivate the alarm sound.
In the event of residual current, over-temperature alarms, communication, or power failures, the alarm location, fault information, and alarm time are stored in the database. Similarly, records are kept when the alarm is lifted or the fault is rectified. Historical data offers various convenient and quick search methods.
Configuration Solutions
Six. Conclusion
In summary, applying LoRa wireless communication technology to electrical fire monitoring systems significantly enhances the quality and efficiency of the monitoring process. It boasts low construction costs, long data transmission distances, and low energy consumption. Consequently, it not only fully meets the requirements for the construction and operation of electrical fire monitoring systems but also satisfies users' needs for daily life and production. Tests have shown that the signal transmission performance of this electrical fire monitoring system is reliable, the data displayed in the system is accurate, and it can be effectively applied in actual production and daily life, thereby positively promoting the improvement of the quality of life and production for residents in our country.
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