Simulation pulse load-based power distribution terminal back-up power supply loading capacity monitoring device

Abstract

The invention discloses a power distribution terminal back-up power supply loading capacity monitoring device based on an analog pulse load, which is connected in series into a charging and discharging loop of a back-up power supply, and particularly relates to the technical field of on-line monitoring of power distribution terminal back-up power supplies. Comprising a main control unit, a battery parameter acquisition module, a pulse discharge module, a communication and early warning module, a modular expansion interface and a double-access interface unit. According to the invention, the switch operation load is simulated on line through the built-in adjustable pulse discharge module, and the instantaneous loading capacity of the power supply is truly tested; by combining multi-parameter acquisition and a closed-loop health assessment model, fusion of dynamic performance verification and static state diagnosis is realized, and the early warning accuracy is remarkably improved; the backup power supply has the functions of modular expansion, double access interfaces and multi-protocol communication, supports on-site early warning and remote monitoring, realizes active operation and maintenance and intelligent management of the backup power supply, and effectively improves the power supply reliability of a power distribution network.

Description

Technical Field

[0001] This invention relates to the field of online monitoring technology for backup power supplies in distribution terminals, and more specifically, to a device for monitoring the load-carrying capacity of backup power supplies in distribution terminals based on simulated pulse loads. Background Technology

[0002] Distribution automation terminals (such as feeder terminal units (FTUs) and distribution terminal units (DTUs) are key equipment for the operation and control of distribution networks. The reliability of their backup power supply (usually valve-regulated lead-acid battery packs) is directly related to whether the switches can be opened and closed correctly in the event of a fault, which is crucial for ensuring the continuity of power supply. However, in actual operation, the failure of the backup power supply has become one of the main reasons for the failure of distribution automation operations.

[0003] Currently, the monitoring and management of backup power supplies have the following limitations: 1. Existing backup power monitoring technologies mainly focus on measuring battery static parameters, such as float charge voltage, cell internal resistance, and surface temperature. Although these parameters can reflect the battery degradation trend to some extent, they are all measurement results under steady-state or small-signal conditions. When the power distribution terminal is handling a fault, the backup power supply needs to provide a high-power pulse current of hundreds of watts in a very short time. There is a common embarrassing situation in the industry where "static parameters are normal, but the switch cannot be turned on at critical moments," which makes maintenance personnel "unsure" of the actual status of the power supply and preventive maintenance lacks effective basis. 2. Existing monitoring devices or systems typically use simple threshold comparison methods for alarms, such as triggering an alarm when the voltage is below a certain value. This approach lacks comprehensive analysis of the correlation between multiple parameters and cannot achieve predictive diagnosis based on battery performance degradation models. Its early warning is essentially "after the fact" or "during the fact," often triggered only when the battery capacity has severely decreased or obvious fault characteristics have appeared. It cannot achieve early warning. In addition, since dynamic performance degradation is not considered, its status assessment results deviate significantly from the actual working capacity of the power supply, which can easily lead to misjudgments (such as releasing degraded batteries) or false alarms (such as misjudging healthy batteries), resulting in low accuracy of operation and maintenance decisions.

[0004] 3. Current operation and maintenance work heavily relies on regular on-site inspections and annual verification discharge tests. Regular inspections are labor-intensive, inefficient, and difficult to detect potential defects. Verification discharge tests require disconnecting the battery pack from the system, which is complex, poses safety risks, and has a long testing cycle (usually once a year). It is impossible to detect performance degradation between two tests in a timely manner. The entire operation and maintenance system is in a passive mode of "fault-driven" or "cycle-driven", which cannot conduct routine and proactive verification of the health status of backup power, and safety hazards are difficult to detect in a timely manner. Summary of the Invention

[0005] To overcome the above-mentioned deficiencies of the prior art, the present invention provides a power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load, connected in series in the charging and discharging circuit of the backup power supply, comprising: The main control unit, as the core processor of the device, is responsible for control logic, data fusion, health assessment, and communication scheduling. The battery parameter acquisition module has its output terminal connected to the first input terminal of the main control unit, and is used to acquire the individual battery voltage, individual battery temperature, total battery pack voltage, loop current and internal resistance parameters of the backup power supply in real time. A pulse discharge module, whose input terminal is connected to the first output terminal of the main control unit, is used to generate a controllable pulse load simulating the switching operation of a power distribution terminal according to the control command of the main control unit. The output terminal of the pulse discharge module is connected in series in the charging and discharging circuit. The communication and early warning module is bidirectionally connected to the main control unit and is used to perform local audible and visual alarms, provide remote signaling nodes, and realize data communication with external monitoring systems. A modular expansion interface is connected to the main control unit for accessing standardized function expansion modules; A dual access interface unit is used to physically connect the device to the charging and discharging circuit, and it includes an aviation plug interface and a terminal block.

[0007] As a further improvement to the technical solution of the present invention, the pulse discharge module includes a high-power switching device and its driving circuit. The main control unit controls the switching of the high-power switching device through a pulse width modulation signal to generate a standard test pulse with a power of about 500W, a duration of not less than 50ms, and adjustable within the range of 0.2s to 5s.

[0008] As a further improvement to the technical solution of the present invention, the main control unit stores and runs a closed-loop health status assessment program, which is configured to perform the following operations: S1. Establish a battery health benchmark model based on the static parameters collected by the battery parameter acquisition module; S2. During the operation of the pulse discharge module, obtain the dynamic drop curve of the battery pack terminal voltage; S3. Compare the dynamic drop curve with the expected drop curve predicted based on the benchmark model to generate a dynamic verification deviation. S4. Correct the benchmark model based on the dynamic verification deviation, and output the load capacity rating and health status diagnosis results of the backup power supply.

[0009] As a further improvement to the technical solution of the present invention, the monitoring accuracy of the battery parameter acquisition module meets the following requirements: the monitoring error of a single cell voltage does not exceed ±0.2%, the monitoring error of a single cell temperature does not exceed ±1℃, the monitoring error of the total voltage does not exceed 0.5%, the monitoring error of the current does not exceed ±1%, and the consistency error of the internal resistance measurement does not exceed ±2%.

[0010] As a further improvement to the technical solution of the present invention, the communication and early warning module includes: Audible and visual alarms are used for on-site early warning. At least one set of passive dry contacts serves as a remote signaling node; Multi-protocol communication interfaces, supporting at least RS-485 and / or RS-232 interfaces, and compatible with Modbus and IEC61850 communication protocols.

[0011] As a further improvement to the technical solution of the present invention, the modular expansion interface is a pin header expansion dock; both the aviation plug interface and the terminal block have anti-electromagnetic interference, waterproof and anti-condensation structures.

[0012] As a further improvement to the technical solution of the present invention, it also includes a battery active balancing module, whose control end is connected to the main control unit and whose execution end is connected to each cell in the battery pack, for performing balancing operations when the voltage difference between cells exceeds a set threshold.

[0013] A non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the operation of a closed-loop health status assessment program.

[0014] The beneficial effects of this invention are: 1. With a built-in, precisely controllable pulse discharge module, it can simulate the high-power instantaneous load required by actual working conditions such as switch opening and closing online without affecting the normal power supply of the power distribution terminal. It can directly test and quantify the instantaneous output capability of the backup power supply, overcome the shortcomings of traditional static parameter monitoring that cannot reflect dynamic performance, and the test results are real and reliable, providing a direct criterion for whether the power supply is "usable and easy to use". 2. By setting up a closed-loop health status assessment model based on dynamic pulse load verification, this model uses the dynamic pulse test results as the basis for real-time verification and correction of the static monitoring model, realizing the fusion analysis of dynamic and static data. This makes the diagnosis not only dependent on slowly changing parameters such as voltage and internal resistance, but also able to more keenly capture the degradation of the battery's dynamic response. Thus, it can identify potential failure batteries that are "still acceptable in terms of static parameters, but have insufficient load-carrying capacity" earlier and more accurately, and achieve early warning. 3. The device integrates regular or controlled automatic performance testing, real-time multi-parameter monitoring, intelligent diagnostic algorithms and hierarchical early warning mechanisms, transforming "replacement after failure" into "condition-based early warning maintenance", which improves the pertinence and predictability of operation and maintenance work, can guide maintenance personnel to prioritize the handling of high-risk power supplies, reduce blind inspections and replacements, and effectively reduce operation and maintenance costs and safety risks. 4. It adopts a modular design and supports flexible expansion of functions through a standard pin header expansion dock. It provides dual access methods of aviation plugs and waterproof terminal blocks, which can be adapted to different interface specifications of existing FTU / DTU and meet the stringent engineering requirements of outdoor cabinets for electromagnetic interference protection, waterproofing and condensation prevention. It is easy to install and easy to deploy and upgrade on a large scale. 5. This invention integrates local sound and light alarm, remote hard-node remote signaling (dry contact) and soft communication based on standard protocols. Alarm information can directly trigger the terminal to send signals, or detailed reports can be uploaded through the data channel. It can be integrated into the existing power distribution automation system, providing a reliable data foundation and technical means for the power distribution master station to realize remote centralized monitoring and refined management of backup power. 6. An active battery balancing module is set up as the preferred solution. The integrated active battery balancing function can automatically reduce the voltage difference between individual cells in the battery pack, effectively alleviate the problem of early battery pack failure caused by inconsistency, thereby extending the service life of the entire backup power system and improving utilization. Attached Figure Description

[0015] Figure 1 This is a system structure block diagram of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: refer to Figure 1 (System structure block diagram) This embodiment provides a power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load. The device is connected in series with the backup power supply (usually a 48V valve-regulated lead-acid battery pack) of the ring network cabinet or pole-mounted switch FTU through a dual access interface unit.

[0018] The main control unit uses an industrial-grade microcontroller (MCU), such as an ARM Cortex-M series chip, as the core of the entire device's control and data processing.

[0019] The battery parameter acquisition module includes a voltage acquisition circuit, a temperature sensor, a Hall current sensor, and an internal resistance measurement circuit. Its output is connected to the first input terminal (i.e., multiple ADC pins) of the main control unit through a high-precision analog-to-digital converter (ADC). Specifically, the voltage acquisition circuit samples the terminal voltage of each battery and the total voltage of the battery pack through a voltage divider and isolation operational amplifier. A surface-mount temperature sensor (such as an NTC) is installed on the surface of a representative battery. A Hall sensor is fitted on the main circuit wire to measure the current. Under the control of the MCU, the internal resistance measurement circuit injects a small AC signal of a specific frequency into the battery or applies a momentary DC load. By analyzing the voltage response, the internal resistance is calculated. All acquired parameters are digitized by the ADC and transmitted to the main control unit at a preset cycle (e.g., once per second).

[0020] The pulse discharge module is the key component of this invention. Its core is a high-power MOSFET (V1) controlled by an isolation drive circuit from the first output terminal (e.g., the PWM output pin) of the main control unit, and a high-power, non-inductive load resistor (R). load After being connected in series with V1, the entire unit serves as the output of the module and is connected to the charging and discharging circuit of the backup power supply. When the main control unit issues a test command, it generates a precisely wide PWM signal to drive V1 to conduct, causing the backup power supply to momentarily pass through R. load Discharge generates a pulse with a high peak current, which is achieved by selecting R. load By adjusting the resistance value (e.g., for a 48V system, choose a resistor of about 4.6Ω to generate a peak power of about 500W) and precisely controlling the PWM pulse width (≥50ms, which can be set in software), the pulse load required for the opening or closing operation of the switch can be simulated.

[0021] The communication and early warning module is bidirectionally connected to the main control unit via interfaces such as UART and SPI, and includes: A sound and light alarm, directly driven by the MCU's GPIO port, is used to emit visual (LED flashing) and audible (buzzer) alarms locally; A set of passive dry contacts output by relays serves as a remote signaling node. When the device diagnoses a fault, the MCU controls the relays to engage and the contacts to close. This signal can be directly acquired by the switch input board of the power distribution terminal (DTU / FTU) and sent to the main station. A multi-protocol communication interface is provided. In this embodiment, an RS-485 transceiver chip is used, which is connected to the UART port of the MCU. The device has an embedded Modbus RTU slave protocol stack, which can package monitoring data and diagnostic results into standard format messages to respond to queries from the background monitoring system or actively send alarms.

[0022] The modular expansion interface consists of two rows of standard-spaced pin headers located on the edge of the circuit board. Its power and ground wires are directly connected to the I / O ports of the main control unit. Users can use this interface to connect expansion function boards such as temperature and humidity sensors, location positioning (GPS / BeiDou), or specific communication (such as LoRa).

[0023] The dual access interface unit provides two parallel physical access methods: one is an aviation plug that conforms to relevant industry standards, which can be directly plugged into the backup power interface of the FTU that uses the aviation plug; the other is a set of industrial terminal blocks for directly crimping wires. Both are electrically connected in parallel internally, and their shells meet the IP65 protection level and have electromagnetic shielding design.

[0024] This invention designs a device for monitoring the load-carrying capacity of backup power supply in a power distribution terminal based on simulated pulse load. The specific workflow is as follows: S1. After the device is connected, each module is initialized, and the battery parameter acquisition module begins to periodically collect data. S2. The main control unit continuously collects and stores static parameters, learns the normal parameter range of the battery pack during the initial operation phase (such as within one week), and establishes a preliminary health benchmark model. S3. Tests can be triggered in three ways: a) Internal timer of the device (e.g., once a month); b) Receive test commands issued by the remote master station through the communication interface; c) The maintenance personnel press the manual test button on the device on site.

[0025] S4. The main control unit controls the pulse discharge module to perform a standard pulse discharge. During this process, the battery parameter acquisition module synchronously captures the dynamic drop curve U(t) of the battery pack terminal voltage at a higher sampling rate (e.g., 1kHz). After the test, the main control unit calls the closed-loop health status assessment program. a. Based on current static parameters, predict the expected voltage drop curve U of a "healthy" battery under standard pulse load using a benchmark model. exp (t); b. Calculate the measured curve U(t) and the expected curve U. exp (t) The deviation value ε at critical time points (such as the pulse end time); c. If ε is less than the first threshold (e.g., 5%), the battery load capacity is considered normal; if ε is between the first and second thresholds (e.g., 15%), the battery load capacity is considered to have decreased, and the warning level is "Caution"; if ε is greater than the second threshold, the battery load capacity is considered to be severely insufficient, and the warning level is "Severe".

[0026] d. Use the ε value from this test to dynamically correct the parameters of the benchmark model, so that it adapts to battery aging and improves the accuracy of subsequent evaluations.

[0027] S5. If the diagnostic results are abnormal, immediately activate the audible and visual alarm and close the remote signaling dry contact. At the same time, send detailed test data, diagnostic results and warning information to the connected FTU / DTU via the RS-485 interface in Modbus message format, and finally transmit it to the distribution automation master station.

[0028] Example 2: Based on Example 1, this example further adds a battery active balancing module. The control end of this module is connected to another GPIO port of the main control unit, and its execution end is connected in parallel with each individual cell in the battery pack through a balancing switch network and a balancing resistor.

[0029] The specific working process is as follows: When the battery parameter acquisition module detects that the voltage of a certain single cell is significantly higher than the average value of the group, and the difference exceeds a set threshold (such as 0.05V), the main control unit will send a command to the battery active balancing module. The battery active balancing module controls the bypass switch of the corresponding single cell to be turned on, so that an equalization current of about 2A flows through the bypass resistor to "eliminate the difference" discharge of the single cell, causing its voltage to approach the average voltage of the group. This process helps to delay the capacity decay of the entire group caused by battery inconsistency and improve the overall lifespan of the backup power supply. This is a preferred embodiment of the present invention.

[0030] In summary, through the synergy of the aforementioned hardware architecture and software algorithms, the device of this invention achieves a leap from "static parameter monitoring" to "dynamic load capacity verification" of the backup power supply of the power distribution terminal, forming a power distribution terminal backup power supply load capacity monitoring device that integrates online testing, intelligent diagnosis, proactive early warning, and remote management.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power distribution terminal backup power supply load-carrying capacity monitoring device based on simulated pulse load, connected in series in the charging and discharging circuit of the backup power supply, characterized in that, include: The main control unit, as the core processor of the device, is responsible for control logic, data fusion, health assessment, and communication scheduling. The battery parameter acquisition module has its output terminal connected to the first input terminal of the main control unit, and is used to acquire the individual battery voltage, individual battery temperature, total battery pack voltage, loop current and internal resistance parameters of the backup power supply in real time. A pulse discharge module, whose input terminal is connected to the first output terminal of the main control unit, is used to generate a controllable pulse load simulating the switching operation of a power distribution terminal according to the control command of the main control unit. The output terminal of the pulse discharge module is connected in series in the charging and discharging circuit. The communication and early warning module is bidirectionally connected to the main control unit and is used to perform local audible and visual alarms, provide remote signaling nodes, and realize data communication with external monitoring systems. A modular expansion interface is connected to the main control unit for accessing standardized function expansion modules; A dual access interface unit is used to physically connect the device to the charging and discharging circuit, and it includes an aviation plug interface and a terminal block.

2. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to claim 1, characterized in that: The pulse discharge module includes a high-power switching device and its driving circuit. The main control unit controls the switching of the high-power switching device through a pulse width modulation signal to generate a standard test pulse with a power of approximately 500W, a duration of not less than 50ms, and adjustable within the range of 0.2s to 5s.

3. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to claim 1, characterized in that: The main control unit stores and runs a closed-loop health status assessment program, which is configured to perform the following operations: S1. Establish a battery health benchmark model based on the static parameters collected by the battery parameter acquisition module; S2. During the operation of the pulse discharge module, obtain the dynamic drop curve of the battery pack terminal voltage; S3. Compare the dynamic drop curve with the expected drop curve predicted based on the benchmark model to generate a dynamic verification deviation. S4. Correct the benchmark model based on the dynamic verification deviation, and output the load capacity rating and health status diagnosis results of the backup power supply.

4. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to claim 1, characterized in that: The monitoring accuracy of the battery parameter acquisition module meets the following requirements: single cell voltage monitoring error not exceeding ±0.2%, single cell temperature monitoring error not exceeding ±1℃, total voltage monitoring error not exceeding 0.5%, current monitoring error not exceeding ±1%, and internal resistance measurement consistency error not exceeding ±2%.

5. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to claim 1, characterized in that: The communication and early warning module includes: Audible and visual alarms are used for on-site early warning. At least one set of passive dry contacts serves as a remote signaling node; Multi-protocol communication interfaces, supporting at least RS-485 and / or RS-232 interfaces, and compatible with Modbus and IEC 61850 communication protocols.

6. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to claim 1, characterized in that: The modular expansion interface is a pin header type expansion dock; both the aviation plug interface and the terminal block have anti-electromagnetic interference, waterproof and anti-condensation structures.

7. The power distribution terminal backup power supply load capacity monitoring device based on simulated pulse load according to any one of claims 1-6, characterized in that: It also includes a battery active balancing module, whose control end is connected to the main control unit and whose execution end is connected to each cell in the battery pack, used to perform balancing operations when the voltage difference between cells exceeds a set threshold.

8. A non-volatile computer-readable storage medium storing a computer program, as described in claim 3, for a power distribution terminal backup power supply load capacity monitoring device based on an analog pulse load, characterized in that... When the computer program is executed by the processor, it implements the operation of the closed-loop health status assessment program as described in claim 3.

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