Intelligent battery pack discharge maintenance management system
Through the intelligent battery pack discharge maintenance and management system, the interlocking control of contactors A and B and the internal resistance analysis method of instantaneous high current discharge, the malfunction and fault problems of battery capacity and internal resistance detection in the prior art are solved, and efficient and accurate battery management is achieved.
Patent Information
- Application Number
- CN202411966032.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-04
AI Technical Summary
The existing battery management system has problems of malfunction and failure when detecting battery capacity and internal resistance, and the traditional verification discharge method requires additional equipment investment and manual operation, which poses safety risks.
An intelligent battery pack discharge maintenance and management system is designed to ensure that the battery pack is in a charged or discharge state through the chain control of contactors A and B, and the voltage and current signals of the single battery are collected during the discharge process. Combined with the internal resistance analysis method of instantaneous large current discharge, the battery capacity and internal resistance are evaluated.
It realizes efficient and accurate detection of the battery status, improves the intelligent level of battery management, and avoids the safety risks of equipment investment and manual operation in traditional methods.
Smart Images
Figure CN119765570A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of battery management, and in particular to an intelligent battery pack discharge maintenance management system. Background Art
[0002] The battery inspection device mainly detects the terminal voltage of each battery in the battery pack. The terminal voltage can directly reflect the overcharge and undercharge of the battery, and can reflect the status of each battery to a certain extent in the discharge state. However, since the battery pack is in a floating charge state for a long time, and the battery with poor performance or poor connection is in a floating charge state, the change of terminal voltage is not obvious, and it is often too late to find abnormalities when the battery is discharged. Therefore, a battery management system with timed discharge maintenance and internal resistance and capacity detection functions is required.
[0003] At present, the most accurate method for testing battery capacity is verification discharge. Taking a 100Ah battery as an example, the standard test method is to discharge at a constant current of 10A at a 10x rate. If the discharge can last for 10 hours, the battery capacity is 100%. However, the biggest disadvantage of this method is that the battery pack is disconnected from the power supply load and the rectifier power supply for a long time during the capacity test. If an AC power outage occurs at this time, the load cannot be powered uninterruptedly. To solve this problem, a backup battery pack can be configured, but this requires additional equipment investment. In addition, common verification discharge equipment generally uses resistance wire or water resistance for verification discharge, and is manually operated, with cumbersome procedures and certain personal risks.
[0004] The AC detection method is often used to measure the internal resistance of the battery, that is, injecting a low-frequency AC current signal I at the two poles of the battery. AC , detect the low-frequency AC voltage value U generated at the two poles of the battery AC , then the battery internal resistance Rb = U AC / I AC According to the battery equivalent circuit, the capacitance threshold C in the battery is relatively large, resulting in a small capacitive reactance. Therefore, when the AC method is used to detect the internal resistance of the battery, what is detected is actually the impedance of the metal resistor and the capacitor in series, while the electrochemical resistance is ignored. In addition, the AC component in the DC power supply will often cause malfunction and failure of the equipment. Summary of the invention
[0005] Purpose of the invention: The purpose of the present invention is to provide an intelligent battery pack discharge maintenance management system, which can put the battery pack in a charging or discharging state, and collect the voltage and current signals of the single cells during the discharge process to analyze the degree of degradation, thereby realizing intelligent management of the battery.
[0006] Technical solution: To achieve the above-mentioned purpose, the intelligent battery pack discharge maintenance and management system described in the present invention includes a battery pack, a load box, an actual load, and a charger for charging the battery pack. The battery pack output is connected to a fuse, and the fuse output is divided into two paths. One output is connected to contactor B to the load box, and the other output is connected to contactor A to the circuit breaker and then to the actual load. The front end of the circuit breaker is connected to the charger. Battery pack monitoring equipment for monitoring the voltage and current of single cells is connected at both ends of the battery pack. The battery pack monitoring equipment feeds back the monitoring information to the battery analysis module in real time to analyze the degree of battery degradation.
[0007] When the battery pack is discharged, the circuit breaker, contactor B and fuse are closed, and contactor A is disconnected; when the battery pack is charged, the circuit breaker, contactor A and fuse are closed, and contactor B is disconnected.
[0008] Among them, the working status of contactor A and contactor B is controlled by a control circuit, and the control circuit includes two sub-circuits of DC220V and DC24V, wherein the DC220V circuit controls contactors A and B, and the DC24V circuit controls the relay, and then uses the relay to control contactors A and B in the DC220V circuit.
[0009] The DC24V subcircuit includes upper and lower branches connected in parallel, the upper branch includes a relay A coil and an operating switch 1 connected in series, and the lower branch includes a relay B coil and an operating switch 2 connected in series.
[0010] Among them, the operating switch 1 includes a button 1 and a patrol meter 1K1 switch connected in parallel, and the operating switch 2 includes a button 2 and a patrol meter 1K2 switch connected in parallel.
[0011] Among them, the DC220V sub-circuit includes upper and lower branches in parallel, the upper branch includes the normally closed contact of relay A, the normally open contact of relay B, and the coil of contactor A in series, and the lower branch includes the normally open contact of relay A, the normally closed contact of relay B, and the coil of contactor B in series.
[0012] The battery analysis module adopts the internal resistance analysis method of instantaneous large current discharge for analysis, including: controlling the battery pack to discharge at a certain current, and recording the voltage U1 and current I of the battery cell in real time during the discharge process; instantaneously increasing the battery pack discharge current when the battery pack terminal voltage is relatively stable, and recording the voltage U2 of the battery cell during this process; calculating the internal resistance Rb=ΔU / I of the battery cell, ΔU=U2-U1, and comparing the calculation result with the battery characteristic data, thereby marking the single cell with poor performance.
[0013] It also includes touch screen monitoring, which can be used to check the battery degradation degree of the battery pack and control the working status of contactor A and contactor B.
[0014] The system confirms whether to start the battery detection operation through an automatic inspection function.
[0015] The automatic inspection function includes:
[0016] (1) The system starts daily inspection to determine whether it is in the online monitoring state or whether a low-quality battery is detected. If the conditions are met, the timer starts counting and returns to the judgment; if the conditions are not met, it proceeds to the next judgment;
[0017] (2) Determine whether the timing time is greater than 1 hour. If so, set the timing to 5 days. If not, proceed to the next step.
[0018] (3) Determine whether the system is in maintenance or pause mode. If the conditions are met, turn off the start signal. After turning off the start signal, determine whether the contactor sends a control signal. If so, the contactor controls the output. If not, continue to determine. If not, proceed to the next determination.
[0019] (4) Determine whether the system is in timing mode. If the conditions are met, the timer starts counting and determines whether the timing time is greater than 30 days. If so, turn on the start signal. If not, return to determine whether the system is in maintenance / pause mode. If not, enter manual mode and determine whether the start signal is input. If the start signal is input, turn on the start signal. If not, enter the timer and make the next determination.
[0020] (5) Determine whether the timing time is greater than 1 day. If so, enter the timer of the timing mode. If not, return to determine whether the start signal is input.
[0021] Beneficial effects: The present invention has the following advantages: 1. The present invention ensures that the battery pack is in a charging or discharging state through the interlocking control of contactors A and B, and obtains the internal resistance of the battery cell based on the voltage and current signals of the single cell collected during the discharge process, combined with the internal resistance analysis method of instantaneous large current discharge, and utilizes the relationship between internal resistance and capacity to evaluate the battery capacity state, effectively improving the detection efficiency and accuracy of the battery state and realizing intelligent management of the battery; 2. The system can realize normal inspection and alarm of the battery pack, manually or automatically select the battery pack for discharge, and can detect the internal resistance and capacity of a single battery during the discharge process, and mark the single cell with poor performance through data statistics and analysis; 3. The touch screen monitoring provides an intuitive and convenient human-computer interaction interface, making the operation easier and the information display clearer. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is the system structure diagram;
[0023] Figure 2This is the control circuit schematic diagram;
[0024] Figure 3 This is the principle diagram of the system's automatic inspection function;
[0025] Figure 4 The voltage and current waveforms of the battery when it generates a large instantaneous discharge current. DETAILED DESCRIPTION
[0026] The technical solution of the present invention is described in detail below in conjunction with the embodiments and drawings.
[0027] like Figure 1 As shown, the system of the present invention includes a battery pack, a battery pack monitoring device, a touch screen monitor, a contactor A, a contactor B, a circuit breaker, and a fuse. The battery pack output is connected to the fuse. The fuse output is divided into two paths, one path is connected to the contactor B to the load box, and the other path is connected to the contactor A to the circuit breaker and then to the actual load. The front end of the circuit breaker is connected to the charger. The battery pack monitoring device is connected to both ends of the battery pack, detects the voltage and current of the single battery in the battery pack, and feeds the monitoring information back to the battery analysis module in real time. The battery analysis module displays the analysis results through the touch screen monitor or sends them to the background administrator. The battery degradation degree of the battery pack can be viewed through the touch screen monitor, and the working status of the battery pack monitoring device, contactor A, contactor B, etc. can be controlled. The charger is used to charge the battery pack to put the battery pack in a floating charge state.
[0028] During normal operation, the circuit breaker, contactor A and fuse are in a closed state, and contactor B is in an open state; when the battery pack is discharging, the circuit breaker, contactor B and fuse are closed, and contactor A is open.
[0029] During normal operation, the actual load is connected to the circuit breaker, the other end of the circuit breaker is connected to contactor A, the other end of contactor A is connected to the fuse, and then connected to the battery pack to form a power supply circuit. When the battery pack is discharging, the load box is connected to contactor B, the other end of contactor B is connected to the fuse, and then connected to the battery pack to form a power supply circuit. Among them, the circuit breaker is used to disconnect the battery pack and the actual load when the battery pack is tested, and the fuse is used to protect the circuit during the charging and discharging process of the battery pack.
[0030] In this system, the output of the inspection instrument switch or the manual button can be used to control the relay, and then the relay can be used to control contactors A and B. The control circuit for controlling the working status of contactor A and contactor B is as follows: Figure 2As shown, it includes two sub-circuits, DC220V and DC24V. The DC24V sub-circuit includes upper and lower branches in parallel, the upper branch includes the relay A coil and the operating switch 1 in series, the lower branch includes the relay B coil and the operating switch 2 in series, the operating switch 1 includes the button 1 and the patrol meter 1K1 switch in parallel, the operating switch 2 includes the button 2 and the patrol meter 1K2 switch in parallel, and the button 1 to the button 2 can achieve the purpose of full manual control.
[0031] The DC220V subcircuit also includes parallel upper and lower branches. The upper branch includes the normally closed contact of relay A, the normally open contact of relay B, and the coil of contactor A in series, and the lower branch includes the normally open contact of relay A, the normally closed contact of relay B, and the coil of contactor B in series. The DC24V subcircuit uses a manual button or an automatic switch of the inspection instrument to control the power on or off of relay coil A or B, thereby controlling the on and off of the contactor coil in the DC220V subcircuit, and at the same time controlling the normally open and normally closed contacts of the series relay and contactor in the circuit to achieve the effect of interlocking control.
[0032] When button 1 is pressed (or the inspection instrument controls the inspection instrument 1k1 to be closed), the coil of relay A is energized, the normally closed contact of relay A in the upper branch of the DC220V sub-circuit is disconnected (originally in a closed state), and the coil of contactor A is de-energized, corresponding Figure 1 The contactor A switch is disconnected (closed in normal operation), and the battery pack is disconnected from the actual load and the charger; the normally open contact of the relay A in the lower branch of the DC220V sub-circuit is closed (originally in the open state), and the contactor B coil is energized, corresponding to Figure 1 The contactor B switch in the circuit is closed (it is in the open state during normal operation), and the battery pack discharges to the load box.
[0033] Pressing button 2 (or the patrol meter controlling patrol meter 1k2 to close) is the same as the above principle, thus realizing interlocking control, that is, the coils of contactor A and contactor B in the upper branch and the lower branch of the DC220V sub-circuit cannot be energized at the same time. Figure 1 The contactor A and contactor B switches in the circuit cannot be connected to the battery pack at the same time. Therefore, the battery pack is either in a state of being charged by the charger or in a state of discharging to the load box.
[0034] The above-mentioned button 1 and inspection meter 1k1 (or button 2 and inspection meter 1k2) can achieve the same effect, the difference is that button 1 is a manual button, and inspection meter 1k1 is an inspection meter automatically controlled.
[0035] like Figure 3As shown, the system working process is: the system starts daily inspection, determines whether the system is in online monitoring state or whether a poor quality battery is detected. If the conditions are met, the timer starts timing and returns to the judgment; if the conditions are not met, enter the next judgment. Here, it is judged whether the timing time is greater than 1 hour. If it is met, the timing is 5 days; if it is not met, enter the next judgment. Here, it is judged whether the system is in maintenance or pause mode. If it is met, the start signal is turned off. After turning off the start signal, it is judged whether the contactor sends a control signal. If it is sent, the contactor controls the output. If not, continue to judge; if it is not met, enter the next judgment. Here, it is judged whether the system is in timing mode. If it is met, the timer starts timing and determines whether the timing time is greater than 30 days. If it is greater, the start signal is turned on. If it is not greater, it returns to determine whether the system is in maintenance / pause mode; if it is not met, enter the manual mode, and determine whether the start signal is input. If the start signal has been input, turn on the start signal. If the start signal is not input, enter the timer and make the next judgment. Here, it is judged whether the timing time is greater than 1 day. If it is greater than 1 day, the timer enters the timing mode. If it is not greater than 1 day, it returns to judge whether the start signal is input.
[0036] During the process of the battery pack discharging to the load box, the battery analysis module uses the internal resistance analysis method of instantaneous large current discharge to analyze the degree of battery degradation, that is, according to the battery characteristics, based on the above system, the battery pack is controlled to discharge at a certain current, and the battery pack monitoring equipment records and saves the voltage and current of the battery cells during the discharge process in real time. When the voltage at the battery pack terminal is relatively stable, the system instantly increases the battery pack discharge current, and the battery pack monitoring equipment records and saves the voltage and current of the battery cells during this process. The main controller further analyzes the instantaneous large current discharge data of the battery pack, calculates the internal resistance of the battery cells, compares the battery characteristic data of the battery manufacturer, and analyzes and calculates the capacity of the battery cells based on the correlation between internal resistance and capacity (the internal resistance of the battery can reflect the battery capacity, and the change of internal resistance also reflects the state and health of the battery. The relationship between the capacity and internal resistance of the battery pack is mainly reflected in that the larger the capacity, the smaller the internal resistance. As the degree of battery degradation increases, its internal resistance will also increase significantly), and gives suggestions on whether to replace it.
[0037] Due to the existence of C (the conduction of current inside the battery includes metal paths and electrochemical paths; the metal paths include poles, busbars, grids, and the resistance between the grids and the paste; the electrochemical paths include the resistance of the plates, electrolytes, and diaphragms; the parallel plates and the dielectric material between them constitute the capacitor C), at the initial moment of discharge, the capacitor discharges and causes a discharge current shock. After a few seconds, the capacitor discharges completely and the battery current I tends to stabilize. At this time, the battery current I and the battery voltage U1 are recorded. At this time, if the load box is cut off, the voltage across the battery will rise. The battery voltage at this time is recorded as U2, and I is the stable battery current before the load is cut off.
[0038] The battery generates an instantaneous large discharge current, and its voltage and current waveforms are as follows: Figure 4 As shown. Since it is an instantaneous discharge, if the drop in battery potential caused by energy loss is ignored, the recovered voltage is ΔU=U2-U1, then it is not difficult to deduce: Rm and Re are connected in series (according to the different current conduction paths, the battery internal resistance is divided into two parts: metal resistance Rm and electrochemical resistance Re). The discharge current is controlled at 0.3C0-0.5C0 (C0 is the capacity of the battery). Comparing the internal resistance value measured by this method with the internal resistance value provided by the battery manufacturer can not only meet the accuracy requirements, but also avoid the impact of large current discharge on the battery.
[0039] Compared with the traditional patrol meter monitoring device, this system improves the detection accuracy and speed by optimizing the detection circuit, and combines the peripheral devices to control the automatic disconnection and connection of the battery pack to the system, as well as the improvement and upgrading of the software, to detect the internal resistance and capacity, so as to achieve the intelligent management of the battery pack, and the touch screen configuration provides a friendly human-computer interaction interface. The existing verification discharge method requires a long time and manual operation, while this system adopts instantaneous large current and automatic operation; in addition, this system also expands the two groups of batteries, that is, one for use and one for backup, and designs a long-term discharge, and the automatic and manual modes can be switched.
[0040] The system can realize normal inspection and alarm of battery packs, manually or automatically select battery packs for discharge, detect the internal resistance and capacity of single battery during discharge, and mark out single battery with poor performance through data statistics and analysis.
Claims
1. An intelligent battery pack discharge maintenance management system, comprising a battery pack, a load box, an actual load, and a charger for charging the battery pack, characterized in that: The battery pack output is connected to the fuse, and the fuse output is divided into two paths. One output is connected to contactor B to the load box, and the other output is connected to contactor A to the circuit breaker and then to the actual load. The front end of the circuit breaker is connected to the charger. Battery pack monitoring equipment for monitoring the voltage and current of the single cell is connected to both ends of the battery pack. The battery pack monitoring equipment feeds back the monitoring information to the battery analysis module in real time to analyze the degree of battery degradation.
2. The intelligent battery pack discharge maintenance management system according to claim 1, characterized in that: When the battery pack is discharged, the circuit breaker, contactor B and the fuse are closed, and the contactor A is disconnected. When the battery pack is charged, the circuit breaker, contactor A and the fuse are closed, and the contactor B is disconnected.
3. The intelligent battery pack discharge maintenance management system according to claim 2, characterized in that: The working states of the contactors A and B are controlled by a control circuit, which includes two sub-circuits, DC220V and DC24V. The DC220V circuit controls the contactors A and B, and the DC24V circuit controls the contactors A and B in the DC220V circuit by controlling the relay.
4. The intelligent battery pack discharge maintenance management system according to claim 3, characterized in that: The DC24V sub-circuit includes upper and lower branches connected in parallel, the upper branch includes a relay A coil and an operating switch 1 connected in series, and the lower branch includes a relay B coil and an operating switch 2 connected in series.
5. The intelligent battery pack discharge maintenance management system according to claim 4, characterized in that: The operating switch 1 includes a button 1 and a patrol meter 1K1 switch connected in parallel, and the operating switch 2 includes a button 2 and a patrol meter 1K2 switch connected in parallel.
6. The intelligent battery pack discharge maintenance management system according to claim 3, characterized in that: The DC220V sub-circuit includes upper and lower branches in parallel. The upper branch includes the normally closed contact of relay A, the normally open contact of relay B, and the coil of contactor A connected in series. The lower branch includes the normally open contact of relay A, the normally closed contact of relay B, and the coil of contactor B connected in series.
7. The battery inspection device according to claim 1, characterized in that: The battery analysis module adopts the internal resistance analysis method of instantaneous large current discharge for analysis, including: controlling the battery pack to discharge at a certain current, and recording the voltage U1 and current I of the battery cell in real time during the discharge process; instantaneously increasing the battery pack discharge current when the battery pack terminal voltage is relatively stable, and recording the voltage U2 of the battery cell during this process; calculating the internal resistance Rb=ΔU / I, ΔU=U2-U1 of the battery cell, and comparing the calculation result with the battery characteristic data, so as to mark the single cell with poor performance.
8. The battery inspection device according to claim 1, characterized in that: It also includes touch screen monitoring, which can be used to check the battery degradation degree of the battery pack and control the working status of contactor A and contactor B.
9. The battery inspection device according to claim 1, characterized in that: The system confirms whether to start the battery detection operation through the automatic inspection function.
10. The battery inspection device according to claim 9, characterized in that: The automatic inspection function includes: (1) The system starts daily inspection to determine whether it is in the online monitoring state or whether a low-quality battery is detected. If the conditions are met, the timer starts counting and returns to the judgment; if the conditions are not met, it proceeds to the next judgment; (2) Determine whether the timing time is greater than 1 hour. If so, set the timing to 5 days. If not, proceed to the next step. (3) Determine whether the system is in maintenance or pause mode. If the conditions are met, turn off the start signal. After turning off the start signal, determine whether the contactor sends a control signal. If so, the contactor controls the output. If not, continue to determine. If not, proceed to the next determination. (4) Determine whether the system is in timing mode. If the conditions are met, the timer starts counting and determines whether the timing time is greater than 30 days. If so, turn on the start signal. If not, return to determine whether the system is in maintenance / pause mode. If not, enter manual mode and determine whether the start signal is input. If the start signal is input, turn on the start signal. If not, enter the timer and make the next determination. (5) Determine whether the timing time is greater than 1 day. If so, enter the timer of the timing mode. If not, return to determine whether the start signal is input.