Portable alternating current load on-line monitoring device

Abstract

This application provides a portable AC load online monitoring device comprising: a sampling module, a power supply module, a main control unit, a display module, and a communication module. The sampling module includes a current sampling module and a voltage sampling module; the current sampling module collects current data, and the voltage sampling module collects voltage data. The power supply module is connected to an external power source and converts it to DC voltage. The main control unit is connected to the power supply module, the current sampling module, and the voltage sampling module. The display module is connected to the main control unit and includes a human-machine interface for displaying and interacting with data. The communication module is connected to the main control unit and includes a wireless communication module and a wired communication module. The wireless communication module connects to a terminal device or the cloud, and the wired communication module connects to a host computer, enabling data upload to the terminal device, the cloud, and the host computer. This portable AC load online monitoring device is small and easy to carry, significantly reducing fault handling time and ensuring the reliability and operational efficiency of subway power supply.

Description

Technical Field

[0001] This utility model relates to the field of urban rail transit technology, specifically to a portable online AC load monitoring device. Background Technology

[0002] In urban rail transit power supply systems, quickly and accurately locating the cause of a fault and restoring power supply when a switch malfunctions is crucial for ensuring smooth operation. Currently, monitoring in large-scale rail transit systems such as the Shanghai Metro is primarily concentrated at the SCADA (Supervisory Control and Data Acquisition) and intelligent metering systems levels, managed separately by the dispatch center and the intelligent operation and maintenance department. In other departments, the integrated protection devices deployed in the power supply system are the core equipment for monitoring electrical faults and executing protective actions.

[0003] However, as equipment ages, the measurement accuracy of some in-service integrated protection devices significantly degrades. Internal components such as current / voltage transformers, sampling circuits, and computing units may experience data distortion or drift due to component aging, environmental factors, or lack of calibration. This reduces the reliability of the device's fault monitoring, judgment, and alarm functions, making it difficult to distinguish between genuine faults and erroneous or failed operation, significantly interfering with and increasing uncertainty in post-fault troubleshooting. Furthermore, digital measurement devices are generally lacking for the numerous and widely distributed 400V AC outgoing line drawers and other end-point loads. This results in the ineffective collection and uploading of end-point load operating status data, creating monitoring blind spots. When end-point switches activate, maintenance personnel struggle to obtain changes in key electrical parameters before and after the fault, greatly increasing the difficulty of fault tracing and cause analysis.

[0004] In summary, there is an urgent need for a new type of monitoring device that can overcome the above-mentioned shortcomings and has high-precision real-time monitoring capabilities, so as to improve fault response speed, location accuracy and operation and maintenance efficiency. Utility Model Content

[0005] The purpose of this application is to propose a portable online AC load monitoring device that uses data-driven decision-making to replace inefficient troubleshooting methods such as traditional empiricism and trial power supply, thereby significantly shortening fault handling time and ensuring the reliability and operational efficiency of subway power supply.

[0006] To achieve the above objectives, this application provides a portable online AC load monitoring device, comprising:

[0007] The sampling module includes a current sampling module and a voltage sampling module, wherein the current sampling module collects current data and the voltage sampling module collects voltage data;

[0008] A power module, which is connected to an external power source and converts it to DC voltage;

[0009] The main control unit is connected to the power module, the current sampling module and the voltage sampling module respectively. The main control unit is equipped with a register for storing data.

[0010] A display module is connected to the main control unit. The display module includes a human-computer interaction interface for displaying and interacting with data.

[0011] The communication module is connected to the main control unit. The communication module includes a wireless communication module and a wired communication module. The wireless communication module is connected to a terminal device or the cloud, and the wired communication module is connected to a host computer.

[0012] In one embodiment, the portable AC load online monitoring device further includes a data transmission module, which is connected to the main control unit and externally connected to a storage device.

[0013] In one embodiment, the portable AC load online monitoring device further includes a USB data interface, which is connected to the data transmission module, and the data transmission module is connected to an external storage device via the USB data interface.

[0014] In one embodiment, the power module includes:

[0015] A single-phase power socket is connected to an external power source. The single-phase power socket has a built-in voltage conversion module that converts the external power source into an internal DC voltage.

[0016] A power switch is located between the external power source and the single-phase power socket.

[0017] In one embodiment, the power module further includes a 24V output port, which is connected to the voltage conversion module and provides 24V DC power to external devices.

[0018] In one embodiment, the wired communication module is configured with a wired communication interface supporting the Modbus RTU protocol, and the wireless communication module is configured with a wireless communication chip supporting the MQTT protocol.

[0019] In one embodiment, the communication module further includes a 4G antenna, and the wireless communication module communicates with the terminal device or the cloud via the 4G antenna.

[0020] In one embodiment, the system further includes a housing, specifically a first side and a second side adjacent to each other. The sampling module, the display module, and the communication module are all disposed on the first side, and the power module is disposed on the second side.

[0021] In one embodiment, the overall frame of the enclosure is made of engineering plastic, and aluminum alloy plates with a thickness of 2mm are installed on the frame. Reinforcing ribs are provided on the frame structure.

[0022] In one embodiment, handles are provided on both sides of the first side, and casters are provided on the box body.

[0023] This application has the following beneficial effects:

[0024] This utility model's portable AC load online monitoring device, through its lightweight enclosure design, human-machine interface, and built-in registers in the main control unit, enables real-time monitoring and fault waveform tracing of terminal loads such as drawers in the 400V subway system, solving the technical problems of large size and limited functionality of traditional equipment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a portable AC load online monitoring device according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the housing of a portable AC load online monitoring device according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the first side of the housing of a portable AC load online monitoring device according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the second side of the housing of a portable AC load online monitoring device according to an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the human-machine interface on a portable AC load online monitoring device according to an embodiment of the present invention.

[0030] Figure Labels

[0031] 1. Single-phase power socket; 2. Power switch; 3. 24V output socket; 4. 4G antenna; 5. 485 communication interface; 6. HMI touch screen; 7. USB data interface; 8. Voltage sampling interface; 9. Current sampling interface; 10. Sampling module; 20. Power module; 30. Main control unit; 40. Display module; 50. Communication module. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] like Figure 1 As shown, this application provides a portable AC load online monitoring device including: a sampling module 10, a power supply module 20, a main control unit 30, a display module 40, and a communication module 50. The sampling module 10 includes a current sampling module and a voltage sampling module; the current sampling module collects current data, and the voltage sampling module collects voltage data. The power supply module 20 is connected to an external power source and converts it to DC voltage. The main control unit 30 is connected to the power supply module 20, the current sampling module, and the voltage sampling module, and is equipped with registers. The display module 40 is connected to the main control unit 30 and includes a human-machine interface (HMI) for data display and interaction. In one embodiment, the display module 40 includes a touchscreen with an HMI on it. Figure 5 As shown, by clicking on "Energy" on the touchscreen, users can view real-time basic parameters such as three-phase voltage / current, power, and cumulative energy. Clicking on "Harmonics" allows users to monitor THD (Total Harmonic Distortion) data, supporting analysis of various harmonics. Clicking on "Multi-rate" displays time-of-use pricing and billing strategy configurations, such as peak-off-peak time periods. Clicking on "Events" allows users to view event logs, including events such as storage device start / stop, parameter changes, and alarm records, with filtering supported by time, type, and status. Clicking on "Data Export" provides a function to export historical data in CSV / Excel formats.

[0034] The communication module 50 is connected to the main control unit 30. The communication module 50 includes a wireless communication module and a wired communication module. The wireless communication module connects to the terminal device or the cloud, while the wired communication module connects to an external host computer, enabling data uploads to the terminal device, the cloud, and the host computer. The communication module 50 is adaptable to both local and cloud-based collaborative operation, enhancing system scalability. The communication module of this portable AC load online monitoring device has serial communication capabilities for two different standards (RS485 and RS232) and achieves physical connection through a DB9 interface. See [link to documentation]. Figure 1 The communication unit enables real-time online uploading, monitoring, and viewing of data, facilitating online fault analysis and helping inspection personnel quickly identify fault areas, thus improving on-site maintenance efficiency. Specifically, the wired communication module is configured with the Modbus RTU protocol, and the wireless communication module is configured with the MQTT protocol. In one embodiment, communication with a terminal device or cloud is achieved via a 4G antenna. In another embodiment, multi-mode communication (4G / 5G / WiFi) is supported.

[0035] In one embodiment, the portable AC load online monitoring device further includes a data transmission module connected to the main control unit. The data transmission module is connected to an external storage device for storing data. Specifically, the portable AC load online monitoring device also includes a USB data interface connected to the data transmission module, which in turn connects to an external storage device.

[0036] In one embodiment, the power module 20 includes a single-phase power socket and a power switch. The single-phase power socket is connected to an external power source and has a built-in voltage conversion module that converts the external power source into an internal DC voltage. The power switch is located between the external power source and the single-phase power socket. In a specific embodiment, the power module 20 also includes a 24V output socket connected to the voltage conversion module, which provides 24V DC power to external devices. In this embodiment, there are two voltage conversion modules, which convert 220V AC power into 220V DC power and 24V DC power respectively. The 220V DC power supplies the main control unit, and the 24V DC power supplies the 24V output socket. Figure 1 The DC24 socket in the middle.

[0037] like Figure 2 As shown, the portable AC load online monitoring device also includes a housing, which has adjacent first and second surfaces. The sampling module, display module, and communication module are all located on the first surface. (See attached image.) Figure 3 The power module is located on the second side; see [link / reference]. Figure 4 In one specific embodiment, to reduce the size and weight of the monitoring device for easier testing, all signal interfaces are integrated on the first side of the enclosure, such as the RS485 communication interface 5, USB data interface 7, voltage sampling interface 8, and current sampling interface 9. A 4G antenna 4 and an HMI touchscreen 6 are also located on the first side. (See [link to relevant documentation]). Figure 2 and Figure 3 The second side of the enclosure is equipped with a single-phase power socket 1, a power switch 2, and a 24V output socket 3. (See attached image.) Figure 2 and Figure 4 This portable AC load online monitoring device can determine the number and type of external interfaces and the operating power supply of the monitoring equipment based on the monitoring project. Furthermore, the overall frame of the enclosure is made of engineering plastic, with 2mm thick aluminum alloy plates mounted on the frame, and reinforcing ribs are incorporated into the frame structure. Additionally, handles are provided on both sides of the first side, and the enclosure is equipped with casters. To facilitate portability, the weight of the monitoring equipment has been kept below 5KG. The device's structure and manufacturing process are more portable and easier to assemble and disassemble. The processing unit, communication unit, and touch display unit are integrated into a sufficiently small device, equipped with a mechanical handle for lightweight carrying. The use of aluminum alloy provides a more robust structure and waterproof functionality.

[0038] In one embodiment, the portable AC load online monitoring device is used as follows: Ensure all switches are in the off position. First, plug the AC power cord into a single-phase power outlet. After verifying that everything is in order, turn on the power switch (i.e., Figure 1 The device automatically operates via the AC power switch, touchscreen, and intelligent monitoring (dedicated test program). Connect the corresponding module data test lines, power lines, and communication lines. Click the touchscreen to enter the monitoring data screen and view the data. This device mainly monitors the following key electrical parameters: Voltage (U): Three-phase voltage (Ua, Ub, Uc), see [link to relevant documentation]. Figure 1 Ua, Ub, and Uc refer to the phase voltages of phases A, B, and C, respectively. These are important parameters for monitoring the phase voltages in a three-phase power system. Un represents the neutral line voltage (in some cases, U0 represents the zero-sequence voltage). In a three-phase four-wire system, the neutral line is the conductor connecting the neutral point of the three-phase power supply to the neutral point of the load. The neutral line voltage Un reflects the imbalance of the three-phase system. If the three-phase load is perfectly balanced, theoretically Un is 0. If the three-phase load is unbalanced, Un will have a certain value. Monitoring Un can help determine if there are any abnormalities in the system. In a three-phase AC power system, the currents in the A, B, and C phase conductors are represented by Ia, Ib, and Ic, respectively. See [link to relevant documentation]. Figure 1 Monitoring these three-phase currents helps to understand the load conditions of each phase in a three-phase system and determine whether the system is operating in a balanced state. For example, if the deviation of the three-phase current values ​​is too large, it may mean that the three-phase load is unbalanced, which may lead to increased line losses, uneven heating of electrical equipment, and other problems. In represents the neutral current. In a three-phase four-wire system, the neutral wire is used to connect the neutral point of the three-phase power supply and the neutral point of the load. In is the current flowing through the neutral wire. Under normal circumstances, when the three-phase load is balanced, the neutral current is theoretically zero, but when the three-phase load is unbalanced, current will flow through the neutral wire. Monitoring the neutral current In can help determine the balance of the three-phase load. For example, if there are a large number of nonlinear loads such as third harmonics in the three-phase load, the neutral current may be too large, causing safety hazards. Sampling of the three-phase currents (Ia, Ib, Ic) may be done using devices such as current transformers (CTs) or Hall effect sensors. Taking a current transformer as an example, its primary side is connected in series with the three phase conductors A, B, and C, respectively, and the secondary side output is connected to the corresponding interface of the current sampling module to obtain the current signals Ia, Ib, and Ic. Hall effect sensors can detect the current in each phase using a non-contact method based on the principle of magnetic field induction, and their output signal is also connected to the current sampling module. Neutral current (In) sampling typically also uses a current transformer or a Hall effect sensor, with its primary side connected in series with the neutral line and its secondary side connected to the corresponding sampling interface of the current sampling module to acquire the neutral current In.

[0039] The main control unit can perform signal processing, parameter calculation, and data storage. The main control chip (such as the STM32F4 series) synchronously samples current and voltage signals via a multi-channel ADC with an adjustable sampling rate (e.g., 1kHz) to calculate the effective values ​​of voltage and current. Continuous monitoring of the effective current value can promptly detect whether a circuit is approaching or exceeding its design current carrying capacity, preventing cable overheating, insulation aging, or even fire. The main control unit calculates active power, apparent power, and power factor in real time, or integrates power to obtain the cumulative energy value. The main control unit can also be equipped with a hardware floating-point unit (FPU) to extract the content of each harmonic and calculate the harmonic distortion (THD): the voltage / current distortion rate of each harmonic (e.g., 5th, 7th, 11th, etc.). Excessive harmonic content can lead to equipment overheating (e.g., transformers, motors), protection malfunctions, and damage to precision instruments. The main control unit can also calculate three-phase imbalance: voltage / current imbalance rate, reflecting uneven load distribution or potential faults. Three-phase imbalance increases line losses and affects motor lifespan. Monitoring data can locate pollution sources and guide remediation. It can also generate fault waveforms: high-resolution (e.g., 128 points / cycle) instantaneous voltage and current waveforms before and after a fault occurs. This is the core basis for diagnosing the nature of the fault. When the current waveform shows a sharp change (sudden increase in amplitude) and the voltage drops sharply, it indicates a short circuit fault. If the current exceeds the set value for a long time, and the waveform shows a gradual rise and fall, it indicates an overload trip. In addition, the instantaneous amplitude and time of current / voltage changes can be used to determine faults such as short circuits and grounding faults.

[0040] The main control unit has built-in registers (such as an 8GB embedded Flash memory, capable of recording 30 days of operational data), with data timestamped for easy event backtracking. Staff regularly inspect critical circuits, establishing historical data baselines and identifying parameter degradation trends (such as gradually increasing current harmonics and rising imbalance), allowing for early intervention. Simultaneously, it comprehensively records fault waveforms and data, providing crucial evidence for in-depth post-incident analysis of accident causes and improvements to system design or protection strategies. This device can analyze fault waveforms offline. Its large-capacity registers ensure long-term continuous operation and sustained data recording. Equipped with load data analysis software, it facilitates fault analysis and troubleshooting, improving work efficiency by identifying fault causes.

[0041] This utility model has the following beneficial effects:

[0042] This utility model's portable AC load online monitoring device, through its lightweight enclosure design, human-machine interface, and built-in registers in the main control unit, enables real-time monitoring and fault waveform tracing of terminal loads such as drawers in the 400V subway system, solving the technical problems of large size and limited functionality of traditional equipment.

[0043] The embodiments described above are merely further illustrations of this application and are not intended to limit this application in any other way. This application may also have various other embodiments. Without departing from the spirit and essence of this application, those skilled in the art can make various corresponding modifications and changes based on this application, but these corresponding modifications and changes should all fall within the protection scope of this application.

Claims

1. A portable alternating current load on-line monitoring device, characterized in that, include: The sampling module includes a current sampling module and a voltage sampling module, wherein the current sampling module collects current data and the voltage sampling module collects voltage data; A power module, which is connected to an external power source and converts it to DC voltage; The main control unit is connected to the power module, the current sampling module and the voltage sampling module respectively. The main control unit is equipped with a register for storing data. A display module is connected to the main control unit. The display module includes a human-computer interaction interface for displaying and interacting with data. The communication module is connected to the main control unit. The communication module includes a wireless communication module and a wired communication module. The wireless communication module is connected to a terminal device or the cloud, and the wired communication module is connected to a host computer.

2. The portable AC load on-line monitoring device according to claim 1, characterized in that, The portable AC load online monitoring device also includes a data transmission module, which is connected to the main control unit and an external storage device.

3. The portable AC load on-line monitoring device according to claim 2, wherein, The portable AC load online monitoring device also includes a USB data interface, which is connected to the data transmission module. The data transmission module is connected to an external storage device via the USB data interface.

4. The portable AC load on-line monitoring device of claim 1, wherein, The power module includes: A single-phase power socket is connected to an external power source. The single-phase power socket has a built-in voltage conversion module that converts the external power source into an internal DC voltage. A power switch is located between the external power source and the single-phase power socket.

5. The portable AC load on-line monitoring device according to claim 4, wherein, The power module also includes a 24V output port, which is connected to the voltage conversion module and provides 24V DC power to external devices.

6. The portable AC load on-line monitoring device of claim 1, wherein, The wired communication module is equipped with a wired communication interface that supports the Modbus RTU protocol, and the wireless communication module is equipped with a wireless communication chip that supports the MQTT protocol.

7. The portable AC load on-line monitoring device of claim 1, wherein, The communication module also includes a 4G antenna, and the wireless communication module communicates with the terminal device or the cloud through the 4G antenna.

8. The portable AC load on-line monitoring device of claim 1, wherein, The portable AC load online monitoring device also includes a housing, which has an adjacent first side and a second side. The sampling module, display module, and communication module are all located on the first side, and the power supply module is located on the second side.

9. The portable AC load on-line monitoring device according to claim 8, wherein, The frame of the enclosure is made of engineering plastic, and aluminum alloy plates with a thickness of 2mm are installed on the frame. Reinforcing ribs are provided on the frame.

10. The portable AC load on-line monitoring device of claim 8, wherein, Handles are provided on both sides of the first side, and casters are provided on the box body.

Images