Solar energy storage iron phosphate battery

Abstract

The application discloses a solar energy storage iron phosphate battery, and relates to the technical field of batteries, which comprises a master controller, an iron phosphate battery pack and a heating device arranged in the iron phosphate battery pack; the master controller is used for acquiring the temperature of each single battery; the temperature difference degree and the temperature difference are calculated according to the temperature of the single battery, the temperature difference is the difference between the minimum temperature threshold and the average temperature, and the temperature difference degree is the variance of the temperature value; the heating mode is determined according to the temperature difference degree and the temperature difference, and the heating mode comprises overall heating and individual heating; the iron phosphate battery pack is heated according to the heating mode, and charging and discharging are allowed only after the heating is completed. The application can accurately preheat the battery before charging, ensures that the battery is in a suitable temperature range during the charging process, and thus improves the charging efficiency and charging safety.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and specifically to a solar energy storage iron phosphate battery. Background Technology

[0002] With the development of power systems and the improvement of their intelligence level, online monitoring devices for transmission lines are being used more and more widely. These online monitoring devices usually require a stable power supply system to ensure their normal operation.

[0003] In existing technologies, lithium iron phosphate battery packs supply power to both transmission lines and online monitoring equipment. Battery power is a common power supply method for online monitoring equipment, particularly suitable for remote areas or regions with limited grid access. These batteries can be replaced or recharged periodically to ensure continuous operation of the equipment.

[0004] Battery power offers the advantage of high flexibility and independence from grid power, but it requires regular maintenance and battery replacement. However, battery power in low-temperature environments can lead to the following problems: First, the battery's conductivity decreases at low temperatures, resulting in reduced charging efficiency. Energy may be wasted and not effectively stored in the battery, further reducing charging efficiency. Second, charging time may be prolonged due to increased internal resistance, as current struggles to conduct into the battery. Furthermore, low temperatures reduce the usable capacity of lithium iron phosphate batteries, meaning less energy can be stored. This implies that at low temperatures, the battery may not be able to store and release the same amount of energy as at normal temperatures. Additionally, at extremely low temperatures, the lithium salt electrolyte within the battery may become viscous, reducing lithium salt solubility and affecting battery performance. Moreover, lithium metal deposition may occur within the battery, potentially leading to safety issues. Finally, frequent charging of lithium iron phosphate batteries at low temperatures can damage battery life, as the charging and discharging processes under these conditions cause stress, leading to the degradation of battery materials.

[0005] Chinese patent (CN202311574709.8) discloses a battery management system and a lithium iron phosphate battery pack for a power supply system. The battery management system connects to the lithium iron phosphate battery pack on the transmission line, and the lithium iron phosphate battery pack has a built-in heating device. The battery management system includes: a status acquisition unit for acquiring the battery status of the lithium iron phosphate battery pack; a microcontroller unit connected to the status acquisition unit for outputting a corresponding heating control command when the battery status indicates that the lithium iron phosphate battery pack is in a low-temperature state; and a battery pack heating unit connected to both the microcontroller unit and the heating device for controlling the heating device to heat the lithium iron phosphate battery pack according to the heating control command. This invention improves the management efficiency of the battery pack by monitoring its operating status in real time through the status acquisition unit, and it can also heat the battery in low-temperature environments through the battery heating unit.

[0006] However, although the aforementioned Chinese patent provides a solution for heating the battery pack by using a built-in heating device, the iron phosphate battery itself generates heat during charging. If external heating is added, it may increase the risk of thermal runaway, especially in cases of battery aging or manufacturing defects. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a solar energy storage iron phosphate battery that can preheat the battery before charging, ensuring that the battery is charged within a suitable temperature range, thereby improving charging efficiency and charging safety.

[0008] The technical solution of this invention: A solar energy storage iron phosphate battery, comprising a main controller, an iron phosphate battery pack, and a heating device disposed within the iron phosphate battery pack; the main controller includes:

[0009] The acquisition unit acquires the temperature of each individual battery cell.

[0010] The calculation unit is used to calculate the temperature difference and temperature variation based on the temperature of a single cell, wherein the temperature variation is the difference between the minimum temperature threshold and the average temperature, and the temperature difference is the variance of the temperature values.

[0011] A determining unit is configured to determine a heating method based on the temperature difference and the temperature difference, wherein the heating method includes overall heating and individual heating.

[0012] The heating unit heats the iron phosphate battery pack according to the heating method described above.

[0013] Preferably, a temperature sensor is also included to collect the temperature of each individual battery cell.

[0014] Preferably, the heating device includes a first heating device and a second heating device, wherein the first heating device is used to achieve overall heating and the second heating device is used to achieve individual heating, and the first heating device and the second heating device adopt a PTC heating element.

[0015] Preferably, determining the heating method based on the temperature difference and temperature variation includes:

[0016] If the temperature difference is greater than the set temperature difference and the temperature difference degree is greater than the set temperature difference degree, then a combination of overall heating and individual heating is used for heating.

[0017] If the temperature difference is greater than the set temperature difference and the temperature difference degree is less than or equal to the set temperature difference degree, then overall heating is used.

[0018] Preferably, if the temperature difference is greater than a set temperature difference and the temperature difference degree is greater than a set temperature difference degree, then a combination of overall heating and individual heating is used for heating, including:

[0019] Remove the cell with the highest temperature and calculate the temperature difference of the remaining cells;

[0020] If the temperature difference of the remaining battery is greater than the set temperature difference, repeat the above steps until the temperature difference of the remaining battery is less than or equal to the set temperature difference.

[0021] Individual cells that are determined to be rejected need to be heated separately.

[0022] Preferably, the rejected individual cells are defined as partial cells; the temperature difference between the partial cells before and after rejection is calculated; and the individual heating time is determined based on this difference.

[0023] Preferably, the SOC of the excluded individual cells is obtained, the difference between the SOC and the mean SOC is calculated, and the individual heating time is corrected based on the difference.

[0024] Preferably, the system further includes a charging control unit, configured to receive charging and discharging control commands output by the main controller based on the remaining battery capacity, and to control the solar panel to charge the iron phosphate battery pack or to control the iron phosphate battery pack to discharge according to the charging and discharging control commands.

[0025] The beneficial effects of this invention are reflected in: a solar energy storage iron phosphate battery, the battery system having an intelligent preheating function, which can accurately preheat the battery before charging, ensuring that the battery is in a suitable temperature range during charging, thereby improving charging efficiency and charging safety. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0027] Figure 1 This is a schematic diagram of the structure of a solar energy storage iron phosphate battery provided in an embodiment of the present invention. Detailed Implementation

[0028] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0029] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0030] like Figure 1 As shown, this embodiment of the invention provides a solar energy storage battery with iron phosphate, comprising a main controller, a battery pack with iron phosphate, and a heating device disposed within the battery pack with iron phosphate. The main controller includes: an acquisition unit for acquiring the temperature of each individual battery cell; a calculation unit for calculating temperature difference and temperature variation based on the temperature of each individual battery cell, wherein the temperature variation is the difference between a minimum temperature threshold and a mean temperature, and the temperature difference is the variance of the temperature values; a determination unit for determining a heating method based on the temperature difference and the temperature variation, wherein the heating method includes overall heating and individual heating; and a heating unit for heating the battery pack with iron phosphate according to the determined heating method until the temperature of all individual batteries is greater than the minimum temperature threshold.

[0031] First, the main controller acquires real-time temperature data from each individual battery cell via a temperature acquisition device. This step is crucial because it provides an accurate information foundation for subsequent temperature analysis and heating strategies. Next, the main controller accurately calculates the temperature difference and temperature variation between individual batteries based on the acquired temperature data. The temperature variation specifically refers to the difference between the minimum temperature threshold and the average temperature of the battery pack, while the temperature variation is quantified by variance in statistics to determine the dispersion of temperatures among individual batteries in the battery pack. With this data, the main controller can intelligently determine the heating method. When the temperature difference and temperature variation exceed the set thresholds, a combination of overall heating and individual heating is used to quickly balance the temperature distribution within the battery pack. Conversely, if the temperature difference and temperature variation are within acceptable ranges, only overall heating is used to maintain the overall temperature stability of the battery pack.

[0032] It is worth mentioning that the heating device provided in this embodiment of the invention is ingeniously designed. It includes a first heating device and a second heating device, which are responsible for overall heating and individual heating, respectively. Both heating methods use PTC heating elements, a material widely praised for its excellent stability and thermal efficiency, which ensures the uniformity and safety of the heating process.

[0033] In this embodiment of the invention, determining the heating method based on the temperature difference and temperature variation includes: if the temperature difference is greater than a set temperature difference and the temperature difference is greater than a set temperature variation, then combined heating of overall heating and individual heating is used; if the temperature difference is greater than a set temperature difference and the temperature difference is less than or equal to the set temperature variation, then overall heating is used.

[0034] Furthermore, if the temperature difference is greater than the set temperature difference and the temperature difference degree is greater than the set temperature difference degree, then combined heating of the whole and individual heating is used, including: removing the individual cell with the highest temperature, calculating the temperature difference degree of the remaining cells; repeating the above steps when the temperature difference degree of the remaining cells is greater than the set temperature difference degree until the temperature difference degree of the remaining cells is less than or equal to the set temperature difference degree; and determining that the removed individual cells need to be heated individually.

[0035] By comprehensively considering both temperature difference and temperature variation, the temperature state of the battery pack can be determined more accurately, allowing for the selection of an appropriate heating method. When both the temperature difference and temperature variation exceed a set threshold, a combination of overall heating and individual heating can be used to quickly balance the temperature distribution within the battery pack, improving charging efficiency and safety.

[0036] When combined heating is required, the hottest individual cell is first removed, and then the temperature difference of the remaining cells is recalculated. This process is repeated until the temperature difference of the remaining cells drops below a set value.

[0037] Specifically, the rejected individual cells are defined as partial cells; the temperature difference between the partial cells before and after rejection is calculated; and the individual heating time is determined based on this difference.

[0038] During the combined heating process, the heating strategy can be further optimized by removing the hottest individual cells and recalculating the temperature differences of the remaining cells. This dynamic adjustment method ensures more uniform and efficient heating, avoiding overheating or underheating.

[0039] Furthermore, during charging, due to the differences between individual cells, a balancing strategy is implemented. If the state of charge (SOC) of a particular cell differs significantly from other cells, it may require more balancing processes. These processes may include charge transfer, discharging, or charging, all of which generate heat.

[0040] Therefore, this embodiment of the invention also introduces a correction mechanism. By obtaining the SOC value of the excluded individual cells and comparing it with the average SOC of the battery pack, the individual heating time can be further adjusted. This dynamic adjustment strategy not only improves the efficiency of the heating process but also effectively avoids safety risks that may be caused by overheating.

[0041] It should be noted that the heating time for individual heating is necessarily shorter than the heating time for global heating.

[0042] Based on the above embodiments, the present invention further includes: a charging control unit, configured to receive a charging and discharging control command output by the main controller according to the remaining battery capacity, and control the solar panel to charge the iron phosphate battery pack or control the iron phosphate battery pack to discharge according to the charging and discharging control command.

[0043] In summary, this invention provides a solar-powered energy storage battery made of iron phosphate, comprising a main controller, an iron phosphate battery pack, and a heating device disposed within the iron phosphate battery pack. The main controller acquires the temperature of each individual battery cell; calculates the temperature difference and temperature variation based on the individual battery cell temperatures, where the temperature variation is the difference between a minimum temperature threshold and a mean temperature, and the temperature difference is the variance of the temperature values; determines a heating method based on the temperature difference and the temperature variation, where the heating method includes overall heating and individual heating; and heats the iron phosphate battery pack according to the chosen heating method, allowing charging and discharging only after heating is complete. This invention enables precise preheating of the battery before charging, ensuring the battery remains within a suitable temperature range during charging, thereby improving charging efficiency and charging safety.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A solar energy storage iron phosphate battery, characterized in that, It includes a main controller, a lithium iron phosphate battery pack, and a heating device disposed within the lithium iron phosphate battery pack; the main controller includes: The acquisition unit acquires the temperature of each individual battery cell. The calculation unit is used to calculate the temperature difference and temperature variation based on the temperature of a single cell, wherein the temperature variation is the difference between the minimum temperature threshold and the average temperature, and the temperature difference is the variance of the temperature values. A determining unit is configured to determine a heating method based on the temperature difference and the temperature difference, wherein the heating method includes overall heating and individual heating. A heating unit heats the iron phosphate battery pack according to the heating method described above; Determining the heating method based on the temperature difference and temperature variation includes: If the temperature difference is greater than the set temperature difference and the temperature difference degree is greater than the set temperature difference degree, then a combination of overall heating and individual heating is used for heating. If the temperature difference is greater than the set temperature difference and the temperature difference degree is less than or equal to the set temperature difference degree, then overall heating is used; If the temperature difference is greater than the set temperature difference and the temperature difference degree is greater than the set temperature difference degree, then combined heating of overall heating and individual heating is used, including: Remove the cell with the highest temperature and calculate the temperature difference of the remaining cells; If the temperature difference of the remaining battery is greater than the set temperature difference, repeat the above steps until the temperature difference of the remaining battery is less than or equal to the set temperature difference. Individual cells that are determined to be rejected need to be heated separately.

2. The solar energy storage iron phosphate battery according to claim 1, characterized in that, It also includes a temperature sensor to collect the temperature of each individual battery cell.

3. The solar energy storage iron phosphate battery according to claim 1, characterized in that, The heating device includes a first heating device and a second heating device. The first heating device is used to achieve overall heating, and the second heating device is used to achieve individual heating. The first heating device and the second heating device adopt PTC heating elements.

4. A solar energy storage iron phosphate battery according to claim 1, characterized in that, Let the rejected individual cells be considered as partial cells; calculate the difference between the temperature difference before and after the partial cells are rejected; determine the individual heating time based on this difference.

5. A solar energy storage iron phosphate battery according to claim 1, characterized in that, Obtain the SOC of the excluded individual cells, calculate the difference between the SOC and the mean SOC, and adjust the individual heating time based on the difference.

6. A solar energy storage iron phosphate battery according to claim 1, characterized in that, Also includes: The charging control unit is used to receive the charging and discharging control command output by the main controller according to the remaining battery capacity, and to control the solar panel to charge the iron phosphate battery pack or to control the iron phosphate battery pack to discharge according to the charging and discharging control command.

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