A battery pack online monitoring system and monitoring method

Abstract

The present invention discloses an online monitoring system and method for a battery pack, the system includes a monitoring host and several single-cell detection modules, the single-cell detection modules are used to monitor the single-cell voltage value, negative pole temperature and internal resistance value, and feed back the monitoring signal to the monitoring host, the monitoring host is used to monitor the total voltage, total current and ambient temperature of the battery pack, and receive the feedback signal of the single-cell detection module, and respond based on the monitoring result; the method includes monitoring the battery pack voltage, ambient temperature, single-cell voltage, battery tolerance, and monitoring current, and when any index exceeds the set range, the monitoring system emits an audible and visual alarm and displays data. The present invention can monitor the battery status in real time, can detect abnormal batteries in advance and give timely alarms, reduce the workload of manual regular operation and maintenance of the battery pack, improve labor productivity, and enhance the advance prediction rate of accidents, and can be applied to DC system monitoring in power plants, substations or other industries.

Description

Technical Field

[0001] The present invention relates to the technical field of power storage batteries, and in particular to an online monitoring system and a monitoring method for a storage battery pack. Background Art

[0002] The battery is an important component of the DC power supply system used in the factory. It mainly provides stable power support for the secondary system in the substation system. When the AC power in the station is working normally, it mainly provides closing power for the circuit breaker. Once a fault occurs in the station system and a tripping accident occurs, the battery will continue to provide power for the relay protection, automatic devices, circuit breaker tripping and closing, rectifier equipment for towing mechanical equipment, communication, etc. in the substation system and maintain it for a certain period of time, ensuring that maintenance personnel can carry out emergency repairs on system faults within the power supply time, thereby effectively avoiding the occurrence of substation safety accidents caused by system failures. Therefore, real-time monitoring of the battery status is very important.

[0003] At present, substation battery packs are mainly maintained in a regular manner. Generally, the voltage and internal resistance of the battery are measured manually on a regular basis, and the battery pack is discharged once a year for verification. This detection method not only has the problem of large maintenance workload and inability to grasp the operating status of the battery pack in a timely manner, but also cannot accurately obtain the real data of the battery pack during operation, and cannot improve the advance prediction rate of accidents. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide an online monitoring system and method for a battery pack, which can monitor the battery status of the battery pack in real time.

[0005] Technical solution: To achieve the above-mentioned purpose, the online monitoring system of a battery pack described in the present invention includes a monitoring host and several single-cell detection modules, wherein the single-cell detection module is used to monitor the single-cell voltage value, negative pole temperature and internal resistance value, and feed back the monitoring signal to the monitoring host, and the monitoring host is used to monitor the total voltage, total current, and ambient temperature of the battery pack, as well as receive feedback signals from the single-cell detection module, and respond based on the monitoring results.

[0006] Wherein, the single-unit detection module communicates with the monitoring host via the SBUS bus.

[0007] Among them, the monitoring host includes a signal acquisition circuit, a signal conditioning circuit, an analog-to-digital conversion circuit, a central processing unit CPU, a communication circuit and a display. The signal collected by the signal acquisition circuit is modulated by the signal conditioning circuit and converted by the analog-to-digital conversion circuit, and then input into the central processing unit CPU. The central processing unit CPU displays the monitoring results through the display.

[0008] The signal acquisition circuit includes a battery pack total voltage acquisition circuit, a battery pack total current acquisition circuit and an ambient temperature acquisition circuit, which are used to measure the total voltage, total current and ambient temperature of the battery pack respectively.

[0009] The battery pack total voltage acquisition circuit adopts differential operational amplifier linear direct sampling.

[0010] The signal conditioning circuit includes a voltage signal conditioning circuit and a current signal conditioning circuit, which are respectively used to modulate the signals collected by the battery pack total voltage collection circuit and the battery pack total current collection circuit.

[0011] The analog-to-digital AD conversion circuit includes a voltage AD conversion circuit and a current AD conversion circuit, which are used to convert the modulated voltage and current signals respectively.

[0012] The present invention provides a monitoring method for the above-mentioned battery pack online monitoring system, comprising:

[0013] (1) Monitor the battery pack voltage and give an alarm when the battery pack voltage is higher than the set "group end overvoltage" or lower than the "group end undervoltage" value;

[0014] (2) Monitor the ambient temperature and issue an alarm when the temperature inside the battery cabinet is higher than the set "overtemperature" value;

[0015] (3) Monitor the voltage of the single cells in the battery pack and give an alarm when the voltage of the single cell is higher than the set "battery overvoltage" or lower than the "battery undervoltage" value;

[0016] (4) Monitor battery tolerance and issue an alarm when the difference between the voltage of any single cell and the average voltage is greater than the set "battery tolerance" value. The average voltage is the recorded battery pack voltage divided by the number of cells;

[0017] (5) Monitor the current and start the fan to dissipate heat when large current charging and discharging is detected.

[0018] When any indicator measured by the monitoring method exceeds a set range, the monitoring system issues an audible and visual alarm.

[0019] Among them, when a fault occurs, the monitoring host records the time and content of the fault. When a large current is discharged, the monitoring host records the start time of the discharge event, the maximum discharge current time, the end time and the discharge current value at each moment.

[0020] Beneficial effects: The present invention has the following advantages: The system and method of the present invention can realize real-time monitoring of the battery status of the battery pack, and can be applied to DC system monitoring in power plants, substations or other industries;

[0021] 2. With the alarm function, it can detect abnormal batteries in advance and give timely warnings, reducing the workload of manual regular operation and maintenance of the battery group, improving labor productivity and enhancing the foreseeability of accidents;

[0022] 3. It can automatically record the last measurement value, grasp the operation status of the substation battery and its performance change trend in real time, accurately obtain the real data of the battery group during operation, discover the problems of the battery group in time, and ensure the safe and stable operation of the substation DC system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the structural diagram of the online monitoring system;

[0024] Figure 2 Circuit diagram for collecting total voltage of battery pack

[0025] Figure 3 This is the monitoring flow chart of the online monitoring system. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described in detail below in conjunction with the embodiments and drawings.

[0027] The battery pack online monitoring system of the present invention comprises a monitoring host and several single-cell detection modules, wherein the single-cell detection modules communicate with the monitoring host via an SBUS bus. The monitoring host comprises a signal acquisition circuit, a signal conditioning circuit, an analog-to-digital (AD) conversion circuit, a central processing unit (CPU), a communication circuit and a display.

[0028] like Figure 1 As shown, the signal acquisition circuit in the monitoring host includes a battery pack total voltage acquisition circuit, a battery pack total current acquisition circuit and an ambient temperature acquisition circuit, which are respectively used to measure the total voltage, total current and ambient temperature of the battery pack; the signal conditioning circuit includes a voltage signal conditioning circuit and a current signal conditioning circuit, which are respectively used to modulate the signals collected by the battery pack total voltage acquisition circuit and the battery pack total current acquisition circuit; the analog-to-digital (AD) conversion circuit includes a voltage AD conversion circuit and a current AD conversion circuit, which are respectively used to convert the modulated voltage and current signals and input them into the CPU; the CPU integrates a signal input port, a signal output port and a communication port.

[0029] The single cell detection module can detect the single cell voltage value, single negative pole temperature and single internal resistance value of the battery, and input the measured value to the CPU through the communication conversion device. The single cell detection module can automatically record the last measured value, and realize the online balancing function of the battery and the function of locating the faulty battery.

[0030] The above battery pack total voltage acquisition circuit adopts differential operational amplifier linear direct sampling. The circuit is as follows: Figure 2 shown.

[0031] The direct sampling method is to configure a collection circuit for the battery pack. The battery voltage first passes through a resistor divider network, and then the converted voltage is transmitted to the microcontroller system for AD conversion through a differential operational amplifier circuit. According to the characteristics of the operational amplifier, the output voltage after the sampling circuit can be analyzed and calculated as:

[0032]

[0033] The present invention further provides a method for realizing online monitoring of a battery pack, such as Figure 3 As shown, specifically:

[0034] Based on the above monitoring system, the following monitoring is performed in real time:

[0035] (1) Monitor and display the battery pack voltage, and give an alarm when the battery pack voltage is higher than the set "group end overvoltage" or lower than the "group end undervoltage" value;

[0036] (2) Monitor the ambient temperature. The main unit and each battery room contain temperature sensors. When the temperature inside the battery cabinet is higher than the set "overtemperature" value, an alarm is triggered.

[0037] (3) Monitor the voltage of the single cells in the battery pack and issue an alarm when the voltage of the single cell is higher than the set "battery overvoltage" or lower than the "battery undervoltage" value;

[0038] (4) Monitor battery tolerance. The recorded battery pack voltage divided by the number of cells equals the average voltage. When the difference between the voltage of any single cell and the average voltage is greater than the set "battery tolerance" value, an alarm is triggered.

[0039] (5) Monitor the current. When a large current charge or discharge is detected, the fan will automatically start to dissipate heat for 30 minutes. When a large current is discharged, the corresponding discharge output node is valid. Normally, the fan will automatically start to dissipate heat for 30 minutes every 10 hours. The fan can also be forced to start on the touch screen, but the fan cannot be turned off by another operation while it is running.

[0040] Based on the above monitoring, when any indicator exceeds the set range, the system will issue an audible and visual alarm, and the fault indicator light on the display panel will be always on or flashing. If the "err" indicator light flashes, it means the current menu is faulty. If it is always on, it means the system is faulty but not the current menu. At the same time, the fault output node is valid, and the alarm content and time are recorded. If a battery is over-voltage, under-voltage or the tolerance value is too large, the alarm "battery fault" will be issued, and the specific information can be viewed from the operation panel. Alarm types include: battery group over-voltage, under-voltage, single battery over-voltage, under-voltage, tolerance alarm, poor insulation detection, temperature alarm, smoke sensor alarm.

[0041] When a fault occurs, the CPU automatically records the time and content of the fault, stores 1,000 latest fault information, and the data can still be saved after power failure. When a large current is discharged, the processor automatically records the start time of the discharge event, the maximum discharge current time, the end time, and the discharge current value at each moment. The stored discharge event data can still be saved after power failure.

[0042] The system can display all measured values ​​through the display, including the voltage and serial number of each single battery, the total voltage of the battery pack, temperature, the charge and discharge current of the battery pack, the positive and negative bus voltages, the positive and negative bus deviation voltages, etc., and has various alarm status indicators. When querying the fault record, the number displayed before the battery fault is the serial number of the faulty battery. The normal inspection battery pack voltage adopts cyclic detection and display.

[0043] The system can set parameters, including battery pack overvoltage and undervoltage values, single battery overvoltage and undervoltage values, tolerance overvoltage value, ambient temperature overvoltage value, high current value, communication parameters, local address, number of battery cells, inspection speed, etc.

[0044] When the displayed battery voltage is inaccurate, you can calibrate each battery voltage individually through the touch screen, or you can calibrate all battery voltages at the same time.

Claims

1. A battery pack online monitoring system, characterized in that: It includes a monitoring host and several single-cell detection modules, wherein the single-cell detection module is used to monitor the single-cell battery voltage value, negative pole temperature and internal resistance value, and feed back the monitoring signal to the monitoring host. The monitoring host is used to monitor the total voltage, total current, and ambient temperature of the battery pack, as well as receive feedback signals from the single-cell detection module and respond based on the monitoring results.

2. The battery pack online monitoring system according to claim 1, characterized in that: The single-unit detection module communicates with the monitoring host via the SBUS bus.

3. The battery pack online monitoring system according to claim 1, characterized in that: The monitoring host includes a signal acquisition circuit, a signal conditioning circuit, an analog-to-digital conversion circuit, a central processing unit CPU, a communication circuit and a display. The signal collected by the signal acquisition circuit is modulated by the signal conditioning circuit and converted by the analog-to-digital conversion circuit and then input into the central processing unit CPU. The central processing unit CPU displays the monitoring results through the display.

4. The battery pack online monitoring system according to claim 3, characterized in that: The signal acquisition circuit comprises a battery pack total voltage acquisition circuit, a battery pack total current acquisition circuit and an ambient temperature acquisition circuit, which are used to measure the total voltage, total current and ambient temperature of the battery pack respectively.

5. The battery pack online monitoring system according to claim 4, characterized in that: The battery pack total voltage acquisition circuit adopts differential operational amplifier linear direct sampling.

6. The battery pack online monitoring system according to claim 3, characterized in that: The signal conditioning circuit comprises a voltage signal conditioning circuit and a current signal conditioning circuit, which are respectively used to modulate the signals collected by the battery pack total voltage collection circuit and the battery pack total current collection circuit.

7. The battery pack online monitoring system according to claim 3, characterized in that: The analog-to-digital AD conversion circuit includes a voltage AD conversion circuit and a current AD conversion circuit, which are used to convert the modulated voltage and current signals respectively.

8. A monitoring method for an online monitoring system for a battery pack according to any one of claims 1 to 7, characterized in that: include: (1) Monitor the battery pack voltage and give an alarm when the battery pack voltage is higher than the set "group end overvoltage" or lower than the "group end undervoltage" value; (2) Monitor the ambient temperature and issue an alarm when the temperature inside the battery cabinet is higher than the set "overtemperature" value; (3) Monitor the voltage of the single cells in the battery pack and give an alarm when the voltage of the single cell is higher than the set "battery overvoltage" or lower than the "battery undervoltage" value; (4) Monitor battery tolerance and issue an alarm when the difference between the voltage of any single cell and the average voltage is greater than the set "battery tolerance" value. The average voltage is the recorded battery pack voltage divided by the number of cells; (5) Monitor the current and start the fan to dissipate heat when large current charging and discharging is detected.

9. The method for online monitoring of a battery pack according to claim 8, characterized in that: When any indicator measured by the monitoring method exceeds a set range, the monitoring system issues an audible and visual alarm and displays data.

10. The method for online monitoring of a battery pack according to claim 8, characterized in that: When a fault occurs, the monitoring host records the time and content of the fault. When a large current is discharged, the monitoring host records the start time of the discharge event, the maximum discharge current time, the end time and the discharge current value at each moment.

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