An optimization method and system for an outdoor power supply SOC

Abstract

The application discloses an outdoor power supply SOC optimization method and system, receives a BMS power-off request, records the current power-off SOC and the RTC clock current power-off time; according to the RTC clock and the preset time interval, the BMS is awakened regularly; it is judged whether the cell monomer voltage is in the platform area, if yes, the SOC is corrected according to the preset calibration quantity, otherwise the SOC is corrected through the OCV table; the calibration quantity is the average quantity of the battery self-discharge in the preset time length obtained by pre-measurement; after completing the SOC correction, the BMS power-off request is initiated; after the user shuts down the BMS, the battery SOC can be corrected regularly, even if the cell monomer voltage of the battery is in the platform period, it can also be corrected through the power-off time, so that more accurate battery SOC data can be obtained when the user starts next time, and the accuracy of the SOC estimation of the outdoor power supply is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of battery application technology, and in particular to a method and system for optimizing the state of charge (SOC) of an outdoor power supply. Background Technology

[0002] With social development and a significant improvement in living standards, more and more people are carrying their own outdoor power supplies for charging mobile phones and laptops, providing lighting, and even barbecuing while traveling. However, while convenient, this also creates new technical challenges. Because household power supplies are used infrequently, sometimes only once every few months, and because of cost-saving considerations, lithium iron phosphate cells are generally used. Therefore, the self-discharge of these cells poses a significant challenge to estimating the State of Charge (SOC).

[0003] The current SOC (State of Charge) of outdoor power supplies is calculated based on real-time integration of current, plus full-charge correction and low-end voltage correction, which has the following drawbacks:

[0004] (1) When the outdoor power supply is not in use, there is no current and the BMS is not powered on. Self-discharge cannot be included in the SOC calculation. Short-term non-use will not have much impact on SOC, but long-term non-use will have a very large impact on SOC.

[0005] (2) Because the lithium iron phosphate cells used cannot be corrected by OCV during the plateau period;

[0006] (3) When the SOC error is large, it will have a serious impact on the customer's use. For example, if the actual SOC is only 20%, but the value fed back to the customer is 50%, the customer may think that the battery is sufficient and does not charge it. However, the battery may be insufficient during use, which will seriously affect the customer's use.

[0007] Therefore, improving the accuracy of SOC estimation for outdoor power supplies has become an urgent problem to be solved. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method and system for optimizing the SOC of outdoor power supplies, which can effectively improve the accuracy of SOC estimation of outdoor power supplies.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] An optimization method for outdoor power supply SOC, comprising the following steps:

[0011] S1. Receive BMS power-down request and record the current power-down SOC and the current power-down time of the RTC clock;

[0012] S2. Wake up the BMS periodically according to the RTC clock and the preset time interval;

[0013] S3. Determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0014] The calibration value is the average amount of self-discharge of the battery within a preset time period, obtained through prior actual measurement.

[0015] S4. After completing the SOC correction, initiate a BMS power-down request.

[0016] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0017] An optimized system for an outdoor power supply system (SOC) is characterized by comprising a battery pack, a battery management system (BMS), an RTC clock, a button cell battery, a timed wake-up circuit, and a background process. The button cell battery powers the RTC clock. The battery pack, RTC clock, timed wake-up circuit, and background process are all connected to the BMS, and the system implements the following steps:

[0018] S1. Receive BMS power-down request and record the current power-down SOC and the current power-down time of the RTC clock;

[0019] S2. Wake up the BMS periodically according to the RTC clock and the preset time interval;

[0020] S3. Determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0021] The calibration value is the average amount of self-discharge of the battery within a preset time period, obtained through prior actual measurement.

[0022] S4. After completing the SOC correction, initiate a BMS power-down request.

[0023] The beneficial effects of the present invention are as follows: The method and system for optimizing the SOC of an outdoor power supply can periodically correct the battery SOC after the user shuts down the BMS. Even if the voltage of a single cell in the battery is in a plateau period, it can be corrected by the duration of power-off, thereby ensuring that more accurate battery SOC data can be obtained when the user starts up next time, effectively improving the accuracy of the SOC estimation of the outdoor power supply. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating an outdoor power supply SOC optimization method according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of an outdoor power supply SOC optimization system according to an embodiment of the present invention;

[0026] Figure 3 This is a flowchart illustrating a specific method for optimizing an outdoor power supply SOC according to an embodiment of the present invention. Detailed Implementation

[0027] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0028] Explanation of related terms:

[0029] Battery pack: The controlled object of this invention includes battery cells, temperature sensors, current sensors, relays, and wiring harnesses, etc.

[0030] BMS: Battery Management System. Its signal acquisition includes (cell voltage, total voltage, current, cell temperature). Based on the acquired signals, it estimates the relevant cell status (SOC, SOP, SOH) and performs charging and discharging actions. It also transmits the acquired temperature, current, voltage and calculated relevant parameters to the EMS system via CAN or RS485 communication.

[0031] Main control board: The controller is not limited to this name. It receives data from each controller, controls and protects the entire energy storage system, and controls the power-on and power-off of the BMS.

[0032] RTC clock: Similar to a regular watch, it keeps a continuous time.

[0033] Timed wake-up: When the BMS is in sleep mode after power-down, the BMS can be woken up by a timed wake-up circuit to perform SOC correction;

[0034] Button battery: When the BMS is in sleep mode, it can supply power to the RTC circuit, ensuring that the clock can keep counting.

[0035] Backend: When the BMS detects a unit undervoltage, it sends an alarm message to the backend to alert the customer to replenish power in time;

[0036] SOC: State of Charge;

[0037] SOP: State of Power;

[0038] SOH: State of Health, battery health status.

[0039] Please refer to Figure 1 as well as Figure 3 An optimization method for an outdoor power supply SOC, comprising the following steps:

[0040] S1. Receive BMS power-down request and record the current power-down SOC and the current power-down time of the RTC clock;

[0041] S2. Wake up the BMS periodically according to the RTC clock and the preset time interval;

[0042] S3. Determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0043] The calibration value is the average amount of self-discharge of the battery within a preset time period, obtained through prior actual measurement.

[0044] S4. After completing the SOC correction, initiate a BMS power-down request.

[0045] As can be seen from the above description, the beneficial effects of the present invention are as follows: The method and system for optimizing the SOC of an outdoor power supply according to the present invention can periodically correct the battery SOC after the user shuts down the BMS. Even if the voltage of a single cell of the battery is in a plateau period, it can be corrected by the duration of power-off, thereby ensuring that more accurate battery SOC data can be obtained when the user starts up next time, effectively improving the accuracy of the SOC estimation of the outdoor power supply.

[0046] Furthermore, the step between steps S2 and S3 includes:

[0047] S21. Determine if the voltage of a single battery cell is low. If so, send an alarm message to remind the user to recharge. Otherwise, proceed to the next step.

[0048] As described above, if an undervoltage condition is detected in a single cell, the system can provide supplemental power to the customer in a trapezoidal manner, thereby minimizing the occurrence of over-discharge of the cell.

[0049] Furthermore, the step of correcting the SOC according to the preset calibration value specifically involves:

[0050] The self-discharge S of the battery cell is calculated based on the preset time interval t and the preset calibrated value ΔSOC:

[0051] S = △SOC*t;

[0052] The corrected battery SOC is calculated based on the battery's SOC at the time of power-off and the self-discharge S of the cell during the power-off period.

[0053] As described above, based on the preset calibration value and time interval, the self-discharge of the battery cell within the preset time interval can be estimated, thereby estimating the current SOC of the cell.

[0054] Furthermore, the outdoor power source is a lithium iron phosphate battery, the voltage range corresponding to the plateau region is 3.25V-3.35V, and the SOC corresponding to the plateau region is 5%-95%.

[0055] As described above, the outdoor power supply is a lithium iron phosphate battery as one embodiment of the present invention. For lithium iron phosphate cells, the SOC in the plateau region is approximately 5% to 95%. From the perspective of single cell voltage, the voltage range corresponding to the plateau region is 3.25V-3.35V, which are basically corresponding.

[0056] Furthermore, the pre-defined method for calculating the standardization ΔSOC includes:

[0057] The outdoor power supply is left idle for a preset idle time. The total amount of electricity consumed within the preset idle time is calculated. The preset calibrated value △SOC is equal to the total amount of electricity consumed divided by the preset idle time.

[0058] As can be seen from the above description, the required calibration quantity can be effectively measured through the above method.

[0059] Furthermore, the specific steps for correcting the SOC using the OCV table are as follows:

[0060] The current temperature of the battery cell is obtained, and the SOC is matched with the current temperature of the battery cell and the voltage of the individual cell in the SOC table to obtain the corrected SOC of the battery.

[0061] As described above, the corresponding battery SOC data can be obtained from the OCV table as a correction value by using temperature and cell voltage.

[0062] Further, step S4 specifically includes:

[0063] After completing the SOC correction, determine whether the BMS wake-up time has reached the preset duration. If so, initiate a BMS power-down request.

[0064] As can be seen from the above description, the duration of each BMS wake-up is limited in order to reduce the power consumption of the BMS.

[0065] Furthermore, step S3 is replaced by:

[0066] S3. Correct the SOC using the OCV table.

[0067] As described above, for some battery types that do not require consideration of the platform area, such as ternary lithium batteries, the SOC can be directly corrected using a copper drum OCV meter.

[0068] Furthermore, step S3 is replaced by:

[0069] S3. Identify the type of outdoor power source. If the outdoor power source is a lithium iron phosphate battery, determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0070] If the outdoor power supply is a ternary lithium battery, the SOC is directly corrected using an OCV meter.

[0071] As described above, by identifying the battery type, a suitable correction strategy can be selected accordingly, thereby correcting the battery SOC more effectively and accurately.

[0072] Please refer to Figure 2 An optimization system for outdoor power supply SOC, characterized in that it includes a battery pack, a BMS, an RTC clock, a button battery, a timed wake-up circuit, and a background process. The button battery powers the RTC clock. The battery pack, RTC clock, timed wake-up circuit, and background process are all connected to the BMS to implement the steps in an optimization method for outdoor power supply SOC, based on the calibrated amount as the average self-discharge of the battery within a preset time period obtained through pre-measured measurements.

[0073] As can be seen from the above description, the beneficial effects of the present invention are as follows: The method and system for optimizing the SOC of an outdoor power supply according to the present invention can periodically correct the battery SOC after the user shuts down the BMS. Even if the voltage of a single cell of the battery is in a plateau period, it can be corrected by the duration of power-off, thereby ensuring that more accurate battery SOC data can be obtained when the user starts up next time, effectively improving the accuracy of the SOC estimation of the outdoor power supply.

[0074] The present invention provides a method and system for optimizing the State of Charge (SOC) of an outdoor power supply, applicable to the SOC optimization and correction of outdoor power supplies.

[0075] Please refer to Figure 1 and Figure 3 Embodiment 1 of the present invention is as follows:

[0076] An optimization method for outdoor power supply SOC, comprising the following steps:

[0077] S1. Receive the BMS power-down request and record the current power-down SOC and the current power-down time of the RTC clock.

[0078] This embodiment presents a method for optimizing the State of Charge (SOC) of an outdoor power source, applicable to outdoor power sources with battery types exhibiting plateau effects, such as lithium iron phosphate batteries. This embodiment uses lithium iron phosphate batteries as an example.

[0079] In this embodiment, when the customer powers off, the main control board will request the BMS to power down. The BMS will respond to the main control board's power-down request and record the battery's SOC and RTC clock time at this time.

[0080] S2. Wake up the BMS at regular intervals according to the RTC clock and the preset time interval.

[0081] In this embodiment, the BMS is woken up by a timing circuit at a set time.

[0082] The step between steps S2 and S3 includes:

[0083] S21. Determine if the voltage of a single battery cell is low. If so, send an alarm message to remind the user to recharge. Otherwise, proceed to the next step.

[0084] In this embodiment, after being woken up, the BMS first determines whether the voltage of a single cell is low. When a cell is found to be low, it will send relevant information to the backend to remind the customer to charge the battery and prevent over-discharge of the cell.

[0085] S3. Determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0086] The calibration value is the average amount of self-discharge of the battery within a preset time period, obtained through prior actual measurement.

[0087] In this embodiment, the calibration amount is the average amount of self-discharge of the battery per day obtained through prior actual measurement.

[0088] In this embodiment, if the cell voltage is not undervoltage, it will be determined whether the cell voltage is in the plateau region. The plateau region specifically refers to the area where the SOC changes but the cell voltage remains basically unchanged. For lithium iron phosphate cells, from the perspective of cell voltage, the voltage range corresponding to the plateau region is generally (3.25V-3.35V). Since the plateau region of lithium iron phosphate cells cannot be corrected by OCV, the SOC is corrected based on the time difference. When the cell voltage is not in the plateau region, it can be directly corrected using an OCV meter.

[0089] The specific steps for correcting the SOC based on the preset calibration value are as follows:

[0090] The self-discharge S of the battery cell is calculated based on the preset time interval t and the preset calibrated value ΔSOC:

[0091] S = △SOC*t;

[0092] The corrected battery SOC is obtained by calculating the difference between the battery's SOC at the time of power-off and the self-discharge S of the cell during the power-off period.

[0093] In this embodiment, the modified SOC = power-down SOC - self-discharge / rated capacity.

[0094] In this embodiment, taking a continuous 10-day period without correction as an example, when OCV correction is not possible, the self-discharge of the cell is calculated to be approximately 10*ΔSOC (calibrated value) based on the calibration value. The calibration value can be obtained approximately through actual measurement; generally, the self-discharge in one month is about 2%, and ΔSOC is about 2% / 30.

[0095] The experimental steps for standardization are as follows:

[0096] First, fully charge the battery; at this point, the SOC is 100%.

[0097] After letting it sit for another month, since it's difficult to estimate the SOC of lithium iron phosphate at this point, it can be fully charged again. Through the charging equipment, we can know how much electricity has been charged. This amount of electricity is exactly the amount of electricity consumed in this month, Q1. Then, Q1 / 30 can be used to calculate how much electricity is consumed per day.

[0098] Finally, multiplying Q1 / 30 by the cumulative idle time can be used to further estimate the SOC value, preventing situations where the SOC remains uncorrected even when the battery is nearly depleted. The cumulative idle time can be estimated through timed wake-up, i.e., the preset time interval.

[0099] The specific steps for correcting SOC using the OCV table are as follows:

[0100] The current temperature of the battery cell is obtained, and the SOC is matched with the current temperature of the battery cell and the voltage of the individual cell in the SOC table to obtain the corrected SOC of the battery.

[0101] In this embodiment, OCV represents, for example, as shown in Table 1 below:

[0102] Table 1

[0103]

[0104]

[0105] Note: In the table above (OCV table), the first row represents the temperature axis and the first column represents the SOC axis.

[0106] The cell voltage in the OCV table is the voltage under static conditions, which can be understood as the voltage collected 30 minutes after power-off. At this time, there is no interference from the current. Because of the characteristics of the cell, the cell voltage is lower when discharging and higher when charging.

[0107] As can be seen from the table above, for lithium iron phosphate, the OCV table shows that within the SOC range of 5% to 95% (corresponding to the aforementioned plateau region), the difference in individual cell voltage is very small, therefore the SOC cannot be corrected using individual cell voltage. When the voltage falls outside the plateau region, the SOC at that time can be determined by looking up the individual cell voltage.

[0108] S4. After completing the SOC correction, initiate a BMS power-down request.

[0109] Step S4 specifically involves:

[0110] After completing the SOC correction, determine whether the BMS wake-up time has reached the preset duration. If so, initiate a BMS power-down request.

[0111] In this embodiment, the BMS operates for approximately one minute during each timed wake-up, after which it enters sleep mode again, reducing the power consumption of the BMS. The timed wake-up period can be, for example, 12 hours; shorter periods would lead to frequent wake-ups and higher power consumption.

[0112] Embodiment 2 of the present invention is as follows:

[0113] An optimization method for outdoor power supply SOC, differing from Embodiment 1 in that step S3 is replaced by:

[0114] S3. Correct the SOC using the OCV table.

[0115] This embodiment presents a method for optimizing the State of Charge (SOC) of an outdoor power source. This method is applicable to battery types where there is no plateau effect and corrections can be made at any stage using an OCV table, such as ternary lithium batteries. This embodiment uses a ternary lithium battery as an example; the OCV table for a ternary lithium battery is shown in Table 2 below.

[0116] Table 2

[0117]

[0118] Table 2 shows that the individual cell voltages of ternary lithium batteries differ significantly at different SOCs. Therefore, the SOC can be calculated from the individual cell voltage table across the entire SOC range. Thus, for SOC correction of ternary lithium batteries, it is not necessary to determine whether they are in a plateau region; correction can be performed directly using the OCV table.

[0119] Embodiment 3 of the present invention is as follows:

[0120] An optimization method for outdoor power supply SOC, differing from Embodiment 1 in that step S3 is replaced by:

[0121] S3. Identify the type of outdoor power source. If the outdoor power source is a lithium iron phosphate battery, determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter.

[0122] If the outdoor power supply is a ternary lithium battery, the SOC is directly corrected using an OCV meter.

[0123] In this embodiment, by identifying the type of outdoor power source, it can be determined whether the outdoor power source is a lithium iron phosphate battery or a ternary lithium battery, thereby enabling the selection of different correction methods.

[0124] Please refer to Figure 2 Embodiment four of the present invention is as follows:

[0125] An optimization system for an outdoor power SOC includes a battery pack, a BMS, an RTC clock, a button battery, a timed wake-up circuit, and a background process. The button battery powers the RTC clock. The battery pack, RTC clock, timed wake-up circuit, and background process are all connected to the BMS to implement the steps in the optimization method of an outdoor power SOC in one of the above embodiments one, two, or three.

[0126] In summary, the method and system for optimizing the SOC of an outdoor power supply provided by this invention can periodically correct the battery SOC after the user powers off the BMS. Even if the voltage of a single cell in the battery is in a plateau period, it can be corrected by the duration of power-off, thereby ensuring that more accurate battery SOC data can be obtained when the user starts up next time, effectively improving the accuracy of SOC estimation for outdoor power supplies.

[0127] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An optimization method for an outdoor power supply SOC, characterized in that, Including the following steps: S1. Receive BMS power-down request and record the current power-down SOC and the current power-down time of the RTC clock; S2. Wake up the BMS periodically according to the RTC clock and the preset time interval; S3. Determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter. The calibration value is the average amount of self-discharge of the battery within a preset time period, obtained through prior actual measurement. S4. After completing the SOC correction, initiate a BMS power-down request; The specific steps for correcting the SOC based on the preset calibration value are as follows: The self-discharge S of the battery cell is calculated based on the preset time interval t and the preset calibrated value ΔSOC: S = △SOC*t; The corrected battery SOC is calculated based on the battery's SOC at the time of power-off and the self-discharge S of the cell during the power-off period. The pre-defined methods for calculating the standardization ΔSOC include: The outdoor power supply is left idle for a preset idle time. The total amount of electricity consumed within the preset idle time is calculated. The preset calibrated value △SOC is equal to the total amount of electricity consumed divided by the preset idle time.

2. The method for optimizing the SOC of an outdoor power supply according to claim 1, characterized in that, The step between steps S2 and S3 includes: S21. Determine if the voltage of a single battery cell is low. If so, send an alarm message to remind the user to recharge. Otherwise, proceed to the next step.

3. The method for optimizing the SOC of an outdoor power supply according to claim 1, characterized in that, The outdoor power source is a lithium iron phosphate battery, and the voltage range corresponding to the platform area is 3.25V-3.35V.

4. The method for optimizing the SOC of an outdoor power supply according to claim 1, characterized in that, The specific steps for correcting SOC using the OCV table are as follows: The current temperature of the battery cell is obtained, and the SOC is matched with the current temperature of the battery cell and the voltage of the individual cell in the SOC table to obtain the corrected SOC of the battery.

5. The method for optimizing the SOC of an outdoor power supply according to claim 1, characterized in that, Step S4 specifically involves: After completing the SOC correction, determine whether the BMS wake-up time has reached the preset duration. If so, initiate a BMS power-down request.

6. A method for optimizing the SOC of an outdoor power supply according to claim 1, 2, 4 or 5, characterized in that, Step S3 is replaced by: S3. Correct the SOC using the OCV table.

7. The method for optimizing the SOC of an outdoor power supply according to any one of claims 1-5, characterized in that, Step S3 is replaced by: S3. Identify the type of outdoor power source. If the outdoor power source is a lithium iron phosphate battery, determine whether the voltage of a single cell is in the plateau region. If so, correct the SOC according to the preset calibration value; otherwise, correct the SOC through the OCV meter. If the outdoor power supply is a ternary lithium battery, the SOC is directly corrected using an OCV meter.

8. An optimization system for an outdoor power supply SOC, characterized in that, The system includes a battery pack, a BMS, an RTC clock, a button battery, a timed wake-up circuit, and a background process. The button battery powers the RTC clock. The battery pack, RTC clock, timed wake-up circuit, and background process are all connected to the BMS to achieve an optimization method for an outdoor power supply SOC as described in any one of claims 1-7.

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