Charging power distribution method applied to energy storage equipment and energy storage equipment

Abstract

The invention relates to the technical field of energy storage, in particular to a charging power distribution method applied to energy storage equipment and the energy storage equipment. The method comprises the following steps: determining a current charging power demand of an energy storage battery; determining the current battery charge state of the energy storage battery; determining a target electric quantity grade corresponding to the current battery charge state of the energy storage battery; wherein electric quantity grades are divided in advance according to the state of charge of the battery, and different electric quantity grades correspond to different charging power distribution strategies; selecting a target charging mode from a high-voltage photovoltaic charging mode, a low-voltage photovoltaic charging mode and a mains supply alternating current charging mode according to a target charging power distribution strategy corresponding to the target electric quantity grade, and distributing charging power for the target charging mode according to the current charging power demand of the energy storage battery; and according to the target charging mode, charging power is distributed to charge the energy storage battery. According to the embodiment of the invention, reasonable distribution and scheduling of the charging power of the multiple input sources can be realized.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and specifically to a charging power distribution method and energy storage device applied to an energy storage device. Background Technology

[0002] With the development of energy storage technology, energy storage devices have been widely used in outdoor scenarios such as camping, emergency rescue, and field operations. This widespread adoption of energy storage devices has also placed higher demands on their ability to be compatible with and manage multiple input sources. Currently, energy storage devices can support three charging paths, including: High-voltage photovoltaic (HV-PV) input: For example, charging energy storage devices by connecting solar panels in series, with a charging voltage between 120 and 150V.

[0003] Low-voltage photovoltaic (LV-PV) input: For example, charging energy storage devices via portable foldable solar panels with a charging voltage between 36 and 60V.

[0004] AC input: Supports 220V / 110V AC input. The energy storage device uses an AC / DC (Alternating Current / Direct Current) module to power the battery or load.

[0005] When faced with the above three input sources, how to efficiently schedule and rationally allocate charging power to avoid power conflicts or energy waste is the key to ensuring the efficient and reliable operation of energy storage devices. Summary of the Invention

[0006] In view of this, embodiments of this application provide a charging power allocation method and an energy storage device for use in energy storage devices, which can realize the reasonable allocation and scheduling of charging power from multiple input sources.

[0007] In a first aspect, embodiments of the present invention provide a charging power distribution method for an energy storage device, the energy storage device including an energy storage battery, the method comprising: Determine the current charging power requirements of the energy storage battery; Determine the current state of charge of the energy storage battery; The target power level corresponding to the current state of charge of the energy storage battery is determined; wherein, the power level is pre-divided according to the state of charge of the battery, and different power levels correspond to different charging power allocation strategies. According to the target charging power allocation strategy corresponding to the target power level, a target charging method is selected from high-voltage photovoltaic, low-voltage photovoltaic and AC mains charging methods, and charging power is allocated to the target charging method according to the current charging power demand of the energy storage battery. The energy storage battery is charged according to the target charging method.

[0008] In some embodiments, the pre-classification of battery capacity levels based on battery state of charge, with different capacity levels corresponding to different charging power allocation strategies, includes: Based on the order of battery state of charge from low to high, at least three battery levels are defined: first battery level, second battery level, and third battery level. In the first power level, high-voltage photovoltaic charging method has a higher priority than low-voltage photovoltaic charging method, and low-voltage photovoltaic charging method has a higher priority than AC mains charging method. In the second power level, high-voltage photovoltaic charging is prohibited, and low-voltage photovoltaic charging has a higher priority than AC mains charging. In the third power level, high-voltage photovoltaic and low-voltage photovoltaic charging methods are prohibited, and only AC mains charging is supported.

[0009] In some embodiments, determining the current charging power requirement of the energy storage battery includes: Determine the current maximum allowable charging power of the energy storage battery; Determine the current battery state parameters of the energy storage battery, including: battery state of charge, battery temperature, and voltage; The correction coefficient is determined based on the current battery state parameters of the energy storage battery; The maximum allowable charging power is corrected according to the correction coefficient to obtain the current charging power requirement of the energy storage battery.

[0010] In some embodiments, determining the correction coefficient based on the current battery state parameters of the energy storage battery includes: The first correction factor is determined based on the current state of charge of the energy storage battery. The second correction factor is determined based on the current battery temperature of the energy storage battery; The third correction factor is determined based on the current voltage of the energy storage battery; The correction coefficient is determined based on the first correction factor, the second correction factor, and the third correction factor.

[0011] In some embodiments, determining the first correction factor based on the current state of charge of the energy storage battery includes: The value of the first correction factor is determined according to the value range of the current state of charge of the energy storage battery. Different state of charge value ranges correspond to different first correction factors. The closer the current state of charge of the energy storage battery is to a full charge, the smaller the value of the first correction factor.

[0012] In some embodiments, determining the second correction factor based on the current battery temperature of the energy storage battery includes: When the current battery temperature of the energy storage battery is within a preset first temperature range, the second correction factor takes the first value. When the current battery temperature of the energy storage battery is in a second temperature range that is less than the first temperature range or in a third temperature range that is greater than the first temperature range, the value of the second correction factor is the second value. Otherwise, the second correction factor takes the third value; Wherein, the first value is greater than the second value, and the second value is greater than the third value.

[0013] In some embodiments, determining the third correction factor based on the current voltage of the energy storage battery includes: When the current voltage of the energy storage battery is within a preset first voltage range, the third correction factor takes the fourth value; When the current voltage of the energy storage battery is in a second voltage range that is greater than the first voltage range, the third correction factor takes the fifth value; When the current voltage of the energy storage battery is in the third voltage range or the fourth voltage range, the third correction factor is set to the sixth value. The voltages in the third voltage range are all less than the first threshold, the voltages in the fourth voltage range are all greater than the second threshold, the first threshold is less than the minimum value in the first voltage range, and the second threshold is greater than the maximum value in the second voltage range. The fourth value is greater than the fifth value, and the fifth value is greater than the sixth value.

[0014] In some embodiments, allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method includes high-voltage photovoltaic and low-voltage photovoltaic charging methods, determine the high-voltage photovoltaic charging capacity and the low-voltage photovoltaic charging capacity. Based on the high-voltage photovoltaic charging capability and the low-voltage photovoltaic charging capability, a first total available photovoltaic charging power is determined; Based on the high-voltage photovoltaic charging capacity and the low-voltage photovoltaic charging capacity, determine the high-voltage photovoltaic charging allocation ratio and the low-voltage photovoltaic charging allocation ratio; The charging power allocated to the high-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery, the first total available photovoltaic charging power, and the high-voltage photovoltaic charging allocation ratio. The charging power allocated to the low-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery, the first total available photovoltaic charging power, and the low-voltage photovoltaic charging allocation ratio.

[0015] In some embodiments, allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method supports only low-voltage photovoltaic charging, the low-voltage photovoltaic charging capability is determined. The charging power allocated to the low-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery and the low-voltage photovoltaic charging capability.

[0016] In some embodiments, allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method includes AC mains charging, the second total available photovoltaic charging power is determined based on the high-voltage photovoltaic charging capacity and / or the low-voltage photovoltaic charging capacity. The charging power allocated for AC mains charging is determined based on the difference between the current charging power demand of the energy storage battery and the second total available photovoltaic charging power.

[0017] In some embodiments, after allocating charging power to the target charging method according to the current charging power demand of the energy storage battery, the method further includes: Determine the power difference between the charging power currently allocated to the target charging method and the actual charging power of the target charging method. Based on the power difference, determine the value of the power speed limit; Based on the current actual charging power of the target charging method and the value of the power speed limit, the final charging power allocated to the target charging method is determined.

[0018] Secondly, embodiments of the present invention provide an energy storage device, comprising: The device includes an energy storage battery, a control module, a high-voltage photovoltaic charging interface, a low-voltage photovoltaic charging interface, and an AC mains charging interface; the control module is used to execute the charging power distribution method described in the first aspect or any one of the first aspects.

[0019] In some embodiments, the energy storage device includes a host, a slave, and a parallel cable; the host is used to control the DC conversion module to distribute charging power according to the charging power distribution method, the host and the slave are electrically connected by the parallel cable, and the slave is charged through the parallel cable.

[0020] The charging power distribution method and energy storage device applied to energy storage devices according to embodiments of the present invention have at least the following beneficial effects: In this embodiment of the invention, the battery capacity is pre-divided according to its State of Charge (SOC), with different capacity levels corresponding to different charging power allocation strategies. Based on this, during the charging process of the energy storage battery, the control module can collect the current SOC of the energy storage battery in real time, determine the capacity level of the current SOC, and determine the target charging power allocation strategy based on the capacity level of the current SOC. When the current SOC of the energy storage battery meets the requirements of the next capacity level, the control module automatically switches to the target charging power allocation strategy corresponding to the next capacity level. Through this embodiment of the invention, various charging methods can be rationally scheduled to charge the energy storage battery. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an energy storage device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of an energy storage device provided in an embodiment of the present invention; Figure 3 A flowchart of a charging power distribution method for energy storage devices provided in an embodiment of the present invention; Figure 4 A flowchart illustrating a method for determining the current charging power requirement of an energy storage battery, as provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of another energy storage device provided in an embodiment of the present invention. Detailed Implementation

[0022] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0023] It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0026] See Figure 1 This is a structural schematic diagram of an energy storage device provided in an embodiment of the present invention. Figure 1 As shown, the energy storage device includes a control module 101 and a battery module 102. The battery module 102 houses the energy storage battery, and the control module 101 is used to schedule external input sources to charge the energy storage battery. Optionally, the energy storage device also includes a high-voltage photovoltaic (HV-PV) charging interface, a low-voltage photovoltaic (LV-PV) charging interface, and an AC mains charging interface. Based on this interface structure, the energy storage device supports the following charging methods: high-voltage photovoltaic (HV-PV), low-voltage photovoltaic (LV-PV), and AC mains charging. The control module 101 manages and schedules these three charging methods. Specifically, the method by which the control module 101 allocates charging power to these three charging methods includes: pre-dividing different energy levels based on the current state of charge (SOC) of the energy storage battery, with different energy levels corresponding to different charging power allocation strategies. When the energy storage battery is charging, the control module 101 obtains the current charging power demand of the energy storage battery in real time. The system first determines the target energy level based on the battery's current state of charge (SOC), and then selects the target charging method from high-voltage photovoltaic (HV-PV), low-voltage photovoltaic (LV-PV), and AC mains power according to the target charging power allocation strategy corresponding to the target energy level, and allocates the charging power accordingly.

[0027] It is understood that the charging power allocation method described in this embodiment of the invention is a hierarchical scheduling strategy. Based on the principles of green priority and power supply stability, this strategy prioritizes high-voltage photovoltaic (HV-PV) charging, followed by low-voltage photovoltaic (LV-PV) charging, and finally supplements charging via AC mains power. Using the charging power allocation method of this embodiment of the invention can achieve the effects of prioritizing the use of clean energy, improving energy efficiency, and preventing battery overcharging.

[0028] See Figure 2 This is a schematic diagram of another energy storage device provided in an embodiment of the present invention. Figure 2 As shown, the energy storage device includes a master unit, a slave unit, and parallel cables. Both the master and slave units contain a battery module 102, and the battery module 102 houses an energy storage battery. Figure 2As shown, the host also includes a control module 101, which can be divided into a main control module 1011 and a host BMS (Battery Management System) 1012. The main control module 1011 and the host BMS 1012 can be located on different chips or implemented on the same chip. The host further includes a DC module 103, a charging input interface 104, a discharging output interface 105, and a parallel interface 106. In the host, the charging input interface 104 includes the aforementioned high-voltage photovoltaic (HV-PV) charging interface, low-voltage photovoltaic (LV-PV) charging interface, and AC mains charging interface. The main control module 1011 controls the DC module 103 to allocate charging power to the charging input interface 104 according to the charging power allocation method of this embodiment. The host BMS 1012 and the slave BMS 107 are respectively used to detect the battery parameters of the energy storage batteries in the host and slave, protecting the safety of the energy storage batteries. The parallel interface 106 of the master and slave devices is electrically connected via a parallel cable. The slave device is charged using the electrical energy input from the master device through the parallel cable. Optionally, another parallel interface 106 of the slave device can be connected to other slave devices via a parallel cable. This embodiment of the invention does not limit the number of slave devices. The discharge output interface 105 in the master device is used to connect to the device to be charged, so as to charge the device through the energy storage battery. Optionally, during charging, the electrical energy input through the charging input interface 104 can charge the energy storage battery in the master device and / or the energy storage battery in the slave device. During discharging, the discharge output interface 105 can charge the device to be charged using the energy storage battery in the master device or the energy storage battery in the slave device. Figure 2 As can be seen, this embodiment of the invention is based on a centralized power supply architecture. In the energy storage device, only the energy storage battery in the host unit has the ability to connect to external input sources such as high-voltage photovoltaic, low-voltage photovoltaic, and AC mains power. The energy storage batteries in the slave units do not support charging power allocation and do not have independent charging capabilities. It is understood that... Figure 1 In the energy storage device shown, the high-voltage photovoltaic (HV-PV) charging interface, low-voltage photovoltaic (LV-PV) charging interface, and AC mains charging interface are all located in the host unit. The control module 101 in the host unit can schedule the high-voltage photovoltaic (HV-PV), low-voltage photovoltaic (LV-PV), and AC mains charging methods to charge the energy storage batteries in the host unit and / or the energy storage batteries in the slave unit. This embodiment of the invention eliminates the identification and scheduling logic of the slave unit by setting only the host unit as the input energy access point, thereby reducing system complexity and hardware costs and improving stability.

[0029] See Figure 3 The flowchart below illustrates a charging power allocation method for energy storage devices, as provided in an embodiment of the present invention. Figure 3The method shown is applied to energy storage devices, and more specifically to the control module 101 within the energy storage device, such as the main control module 1011. Figure 3 As shown, the processing steps of this method include: 201. Determine the current charging power requirements of the energy storage battery. .

[0030] 202. Determine the current state of charge (SOC) of the energy storage battery.

[0031] 203. Determine the target energy level corresponding to the current state of charge (SOC) of the energy storage battery. In this embodiment of the invention, energy levels are pre-defined based on the battery SOC, and different energy levels correspond to different charging power allocation strategies.

[0032] 204. Based on the target charging power allocation strategy corresponding to the target power level, select the target charging method from high-voltage photovoltaic, low-voltage photovoltaic and AC mains charging methods.

[0033] 205, based on the current charging power requirements of the energy storage battery. Allocate charging power to the target charging method.

[0034] 206. Distribute charging power to charge the energy storage battery according to the target charging method.

[0035] Optionally, the energy storage battery in steps 201-206 above is an energy storage battery to be charged, which can be the energy storage battery in the host and / or the energy storage battery in the slave.

[0036] In some embodiments, the main control module 1011 pre-classifies the battery capacity levels based on the battery's State of Charge (SOC), with different capacity levels corresponding to different charging power allocation strategies. Based on this, during the charging process of the energy storage battery, the main control module 1011 can collect the current SOC of the energy storage battery in real time through the host BMS 1012 and / or slave BMS 107. The main control module 1011 determines the capacity level of the energy storage battery based on its current SOC and determines the target charging power allocation strategy accordingly. When the current SOC of the energy storage battery meets the requirements of the next capacity level, the main control module 1011 automatically switches to the target charging power allocation strategy corresponding to the next capacity level. Through the embodiments of the present invention, various charging methods can be rationally scheduled to charge the energy storage battery. Moreover, when scheduling various charging methods, the method of the present invention can prioritize the use of high-voltage photovoltaic (HV-PV) and low-voltage photovoltaic (LV-PV) charging methods to charge the energy storage battery, and finally supplement the energy storage battery with AC mains charging method, so as to achieve the technical effects of prioritizing the use of clean energy, improving energy efficiency ratio and preventing overcharging of energy storage battery.

[0037] The hierarchical scheduling strategy of the present invention will be described first below.

[0038] In this embodiment of the invention, the battery capacity is pre-divided into different levels based on the State of Charge (SOC). The general principle for different charging power allocation strategies corresponding to different capacity levels is: high-voltage photovoltaic (HV-PV) is prioritized for charging the energy storage battery, followed by low-voltage photovoltaic (LV-PV), and finally, AC mains power is used for supplementary charging. Based on this principle, this embodiment of the invention divides the battery capacity into at least three levels: a first level, a second level, and a third level, according to the order of battery SOC from low to high. It can be understood that the SOC range corresponding to the first level is smaller than that corresponding to the second level, and the SOC range corresponding to the second level is smaller than that corresponding to the third level. In the first level, high-voltage photovoltaic charging has a higher priority than low-voltage photovoltaic charging, and low-voltage photovoltaic charging has a higher priority than AC mains charging. It can be understood that the first level represents a low SOC state; in this low SOC state, high-voltage photovoltaic charging is prioritized, with low-voltage photovoltaic and AC mains power used as supplementary charging methods. In the second energy level, high-voltage photovoltaic (PV) charging is prohibited, and low-voltage PV charging takes precedence over AC mains charging. This is understandable because if the SOC of the energy storage battery increases from the first energy level to the second, prioritizing high-voltage PV charging could easily lead to overcharging. Therefore, to avoid overcharging caused by uncontrolled high-voltage PV injection, high-voltage PV charging is disabled in the second energy level, with low-voltage PV charging prioritized and AC mains charging used as a supplement. In the third energy level, both high-voltage and low-voltage PV charging are prohibited, and only AC mains charging is supported. This is understandable because if the SOC of the energy storage battery further increases from the second to the third energy level, PV is completely disabled, and only AC trickle charging is used.

[0039] In a specific example, when the SOC of the energy storage battery is less than 80%, it is at the first energy level; when the SOC is between 80% and 90%, it is at the second energy level; and when the SOC is greater than 90%, it is at the third energy level. Corresponding to this tiered scheduling strategy, when the SOC of the energy storage battery is less than 80%, high-voltage photovoltaic charging is prioritized, and low-voltage photovoltaic and AC mains charging are also supported in this level, with low-voltage photovoltaic charging having a higher priority than AC mains charging. When the SOC of the energy storage battery is between 80% and 90%, to avoid overcharging caused by uncontrolled injection of high-voltage photovoltaic power, only low-voltage photovoltaic and AC mains charging are allowed, with low-voltage photovoltaic charging having a higher priority than AC mains charging. Furthermore, when the SOC of the energy storage battery is greater than 90%, photovoltaic charging is completely disabled, and only AC mains charging is used for trickle charging of the energy storage battery.

[0040] In the charging power allocation method described in this embodiment of the invention, clean energy is preferentially used to charge the energy storage battery, extending the outdoor operating time of the energy storage device. Furthermore, in the hierarchical scheduling strategy of this embodiment, when the SOC of the energy storage battery meets the next higher capacity level, the target charging mode is automatically switched to avoid the overcharging risk caused by continuous photovoltaic injection, thus protecting the lifespan of the energy storage battery.

[0041] After explaining the hierarchical scheduling strategy of the embodiments of the present invention, the steps 201-206 of the method of the embodiments of the present invention will be described in detail below.

[0042] See Figure 4 The above is a flowchart illustrating a method for determining the current charging power requirement of an energy storage battery according to an embodiment of the present invention. Figure 4 As shown, the specific processing steps to achieve step 201 above include: In 2011, the current maximum allowable charging power of energy storage batteries was determined. Optionally, current energy storage batteries This can be determined by the main control module 1011.

[0043] In step 2012, determine the current state parameters of the energy storage battery. These parameters include the battery's state of charge (SOC), battery temperature, and voltage. In this step, the SOC can be the same parameter as the current SOC of the energy storage battery in step 202.

[0044] In 2013, correction coefficients were determined based on the current state parameters of the energy storage battery. .

[0045] In 2014, according to the correction factor correct the current maximum allowable charging power of the energy storage battery to obtain the current charging power demand of the energy storage battery .

[0046] In the above step 2013, according to the current battery state parameters of the energy storage battery, determine the correction factor , including: determine the first correction factor according to the current state of charge (SOC) of the energy storage battery. Determine the second correction factor according to the current battery temperature of the energy storage battery. Determine the third correction factor according to the current voltage of the energy storage battery. Determine the correction factor according to the first correction factor, the second correction factor and the third correction factor. In the embodiment of the present invention, according to the current state of charge (SOC), battery temperature and voltage of the energy storage battery, the maximum allowable charging power of the energy storage battery is corrected, which can limit the charging current while ensuring the charging of the energy storage battery, prevent the overcharging of the energy storage battery, and protect the life of the energy storage battery.

[0047] In some embodiments, as the state of charge (SOC), battery temperature and voltage of the energy storage battery indicate that the energy storage battery is approaching full charge, the values of the first correction factor, the second correction factor and the third correction factor decrease accordingly, so that the corrected charging power demand decreases, achieving the effect of limiting the charging current. The following will separately describe the specific implementation methods for determining the first correction factor, the second correction factor and the third correction factor.

[0048] First correction factor: The value of the first correction factor is determined according to the range of values of the current state of charge (SOC) of the energy storage battery. Different ranges of SOC values correspond to different first correction factors. The closer the current state of charge (SOC) of the energy storage battery is to full charge, the smaller the value of the first correction factor, so as to achieve the effect of limiting the charging current. Further, when determining the first correction factor, the range of SOC values divided according to SOC can be the same as the range of power levels divided in the above hierarchical scheduling strategy, or the range of SOC values can be re-divided according to SOC in this step.

[0049] In a specific example, the first correction factor is expressed as . The divided ranges of SOC values are SOC ≤ 70%, 70% < SOC ≤ 85%, 85% < SOC ≤ 90% and SOC > 90%. Different ranges of SOC values correspond to different .

[0050] Specifically, when the current SOC of the energy storage battery ≤ 70%, = 1.0.

[0051] When the current SOC of the energy storage battery satisfies 70% < SOC ≤ 85%, as SOC ranges from 70% → 85%, let Linearly decrease from 1.0 to 0.7.

[0052] When the current SOC of the energy storage battery satisfies 85% < SOC ≤ 90%, let = 0.5.

[0053] [[ID=1,4]]When the current SOC of the energy storage battery > 90%, = 0.1.

[0054] Second correction factor: In the embodiments of the present invention, the second correction factor is determined according to the current battery temperature of the energy storage battery. In a specific implementation, the first temperature range, the second temperature range, and the third temperature range can be pre-divided according to the battery temperature. Among them, the temperatures in the second temperature range are all less than the first temperature range, the temperatures in the third temperature range are all greater than the first temperature range. Additionally, it may also include a fourth temperature range less than the minimum value in the second temperature range and a fifth temperature range greater than the maximum value in the third temperature range.

[0055] Among them, when the current battery temperature of the energy storage battery is within the preset first temperature range, the second correction factor takes the first value; when the current battery temperature of the energy storage battery is in the second temperature range less than the first temperature range or in the third temperature range greater than the first temperature range, the value of the second correction factor is the second value; otherwise, the second correction factor takes the third value, that is, when the current battery temperature of the energy storage battery is in the fourth temperature range or the fifth temperature range, the second correction factor takes the third value. Optionally, the first value is greater than the second value, and the second value is greater than the third value.

[0056] In the embodiments of the present invention, the above-mentioned first temperature range may correspond to the temperature range when the energy storage battery has a low power level, and the above-mentioned second temperature range or third temperature range corresponds to the temperature range when the energy storage battery has a high power level. That is, as the battery is gradually charged, the value of the second correction factor becomes smaller and smaller, achieving the effect of limiting the charging power.

[0057] In a specific example, the second correction factor is expressed as , and the battery temperature of the energy storage battery is expressed as T. Then the first temperature range is 10 °C ≤ T ≤ 45 °C, the second temperature range is 0 °C ≤ T < 10 °C, the third temperature range is 45 °C < T ≤ 55 °C, the fourth temperature range is T < 0 °C, and the fifth temperature range is T > 55 °C. Different temperature ranges correspond to different .

[0058] Specifically, when 10 °C ≤ T ≤ 45 °C, = 1.0.

[0059] When 0 °C ≤ T < 10 °C or 45 °C < T ≤ 55 °C, = 0.5.

[0060] When T < 0 °C or T > 55 °C, = 0.0 (charging of the energy storage battery is prohibited).

[0061] The third correction factor: In the embodiments of the present invention, the third correction factor is determined according to the current voltage of the energy storage battery. In a specific implementation, the first voltage range and the second voltage range can be pre-divided according to the battery voltage, where the voltage of the second voltage range is greater than that of the first voltage range. In addition, it can also include a third voltage range less than the first threshold and a fourth voltage range greater than the second threshold range, where the first threshold is less than the minimum value in the first voltage range and the second threshold is greater than the maximum value in the second voltage range.

[0062] When the current voltage of the energy storage battery is within the preset first voltage range, the third correction factor takes the value of the fourth value; when the current voltage of the energy storage battery is within the second voltage range greater than the first voltage range, the third correction factor takes the value of the fifth value; when the current voltage of the energy storage battery is within the third voltage range or the fourth voltage range, the third correction factor takes the value of the sixth value. Optionally, the fourth value is greater than the fifth value, and the fifth value is greater than the sixth value.

[0063] In the embodiments of the present invention, the above voltage ranges are divided according to the voltage change range of the battery from a low state of charge to a full state of charge. The above first voltage range corresponds to the voltage range when the energy storage battery has a low state of charge, and the above second voltage range corresponds to the voltage range when the energy storage battery has a high state of charge. That is, as the battery is gradually charged, the value of the third correction factor becomes smaller and smaller. The above third voltage range or fourth voltage range corresponds to the under-voltage or over-voltage of the battery, and the value of the third correction factor is further reduced. In the embodiments of the present invention, as the state of charge of the battery changes during the charging process, the third correction factor is gradually reduced to achieve the effect of limiting the charging power.

[0064] In a specific example, the third correction factor is expressed as , and the voltage of the energy storage battery is expressed as V. The first voltage range is 3.43 V ≤ V ≤ 3.45 V, the second voltage range is 3.45 V < V ≤ 3.5 V, the third voltage range is V < 2.5 V, and the fourth voltage range is V > 3.5 V. Among them, different voltage ranges correspond to different .

[0065] Specifically, when 3.43 V ≤ V ≤ 3.45 V, = 1.0.

[0066] When 3.45 V < V ≤ 3.5 V, = 0.5.

[0067] When V < 2.5 V or V > 3.5 V, = 0.0, that is, when the energy storage battery is under-voltage or over-voltage, charging the energy storage battery is prohibited.

[0068] In the embodiment of the present invention, after obtaining the above , <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​(2) Based on the high-voltage photovoltaic charging capacity and low-voltage photovoltaic charging capability Determine the first total available photovoltaic charging power. In one implementation, (3) Based on the high-voltage photovoltaic charging capacity and low-voltage photovoltaic charging capability Determine the high-voltage photovoltaic charging allocation ratio and low-voltage photovoltaic charging allocation ratio In one implementation, . Among them, if If the value is 0, it means that the high-voltage photovoltaic and low-voltage photovoltaic cannot participate in energy supply, and the energy storage battery is charged through the AC power supply. (4) According to the current charging power demand of the energy storage battery. First total available photovoltaic charging power and the allocation ratio of high-voltage photovoltaic charging The charging power allocated for high-voltage photovoltaic charging is determined. (5) Based on the current charging power requirements of the energy storage battery. First total available photovoltaic charging power and the low-voltage photovoltaic charging allocation ratio The charging power allocated for low-voltage photovoltaic charging is determined. In one specific implementation: .

[0074] .

[0075] In this embodiment of the invention, when the photovoltaic charging methods supported by the target charging method only include low-voltage photovoltaic charging, the low-voltage photovoltaic charging capability is determined. Because low-voltage photovoltaic charging is prohibited, high-voltage photovoltaic charging capacity is limited. Based on the current charging power requirements of energy storage batteries. and low-voltage photovoltaic charging capability The charging power allocated for low-voltage photovoltaic charging is determined. In one specific implementation, when the photovoltaic charging methods supported by the target charging method only include low-voltage photovoltaic charging methods, It should be noted that when the target charging method only supports low-voltage photovoltaic charging, AC mains charging can also be used to replenish the energy storage battery.

[0076] In this embodiment of the invention, when the target charging method includes AC mains charging, a second total available photovoltaic charging power is determined based on the high-voltage photovoltaic charging capacity and / or the low-voltage photovoltaic charging capacity. The charging power allocated to the AC mains charging method is determined based on the difference between the current charging power demand of the energy storage battery and the second total available photovoltaic charging power. It is understandable that AC mains charging primarily serves to replenish the energy storage battery. When the target charging method includes AC mains charging, it can also include high-voltage photovoltaic charging and / or low-voltage photovoltaic charging. The calculation method for the second total available photovoltaic charging power is the same as that for the first total available photovoltaic charging power. Specifically, when the second total available photovoltaic charging power includes high-voltage photovoltaic charging, the high-voltage photovoltaic charging capacity is determined; otherwise, it is set to 0. Similarly, when the second total available photovoltaic charging power includes low-voltage photovoltaic charging, the low-voltage photovoltaic charging capacity is determined; otherwise, it is set to 0.

[0077] In a specific example The calculation method is shown in the following formula: .

[0078] In the above formula, The compensation amount set to prevent jitter in photovoltaic charging is a known value, for example... The value is 10W.

[0079] Combining the hierarchical scheduling strategy and the power allocation method for the target charging mode mentioned above, a specific example of a charging power allocation method is provided, including: obtaining the current SOC of the energy storage battery, determining the target charging mode based on the current SOC level of the energy storage battery, and allocating charging power to the target charging mode.

[0080] (1) When SOC ≤ 80%, high-voltage photovoltaic (PV), low-voltage PV, and AC mains charging are permitted for charging the energy storage battery. High-voltage PV charging has higher priority than low-voltage PV charging, and low-voltage PV charging has higher priority than AC mains charging. The method for allocating charging power to high-voltage and low-voltage PV is as follows: .

[0081] .

[0082] When 80% < SOC ≤ 90%, the high-voltage PV charging method is prohibited, and the low-voltage PV charging method and the mains AC charging method are allowed. Among them, the priority of the low-voltage PV charging method is higher than that of the mains AC charging method. Allocating the charging power for the low-voltage PV charging method includes: .

[0083] .

[0084] When SOC > 90%: The high-voltage PV and low-voltage PV charging methods are disabled, and only the mains AC charging method is used to charge the energy storage battery.

[0085] In this method, .

[0086] In the above (1)-(3), allocating the charging power for the mains AC method includes: .

[0087] In some embodiments, after determining the target charging method and allocating the charging power for the target charging method in the above manner, it is also necessary to perform slope speed limit control on the allocated charging power to prevent damage to the energy storage battery caused by the jump of the charging power.

[0088] Specifically, the slope speed limit control mechanism includes: determining the power difference between the charging power currently allocated for the target charging method and the current actual charging power of the target charging method. Based on this power difference, determine the value of the power speed limit. Based on the current actual charging power of the target charging method and the value of this power speed limit, determine the final charging power allocated for the target charging method.

[0089] In a specific implementation manner, the slope speed limit control mechanism is expressed by the formula: .

[0090] In the above formula, , respectively represent the input channels corresponding to the high-voltage PV, low-voltage PV and mains AC charging methods.

[0091] : represents the actual charging power of the x input channel at the current time t.

[0092] : represents the charging power of the x input channel calculated currently.

[0093] represents the power difference between the charging power of the x input channel calculated currently and the current actual charging power of the x input channel.

[0094] : Indicates the power limiting slope, which is a fixed value, such as 50W / s.

[0095] In this formula, if If it is a positive number, then Values , ;if If it is negative, then The value is - , . This represents the final charging power allocated to input channel x, and is calculated at time t+1 according to... Charging the energy storage battery. Through the embodiments of this invention, the gradual increase in charging power of each input channel can be limited, preventing excessive or insufficient charging power from causing damage to the energy storage battery.

[0096] Corresponding to the above-described charging power distribution method applied to energy storage devices, this embodiment of the invention also provides an energy storage device. This energy storage device adopts a computer architecture and includes structures for implementing the functions of the control module 101 in the host, particularly including structures for implementing the functions of the main control module 1011. For example... Figure 5 As shown, the structure of the main control module 1011 includes a processor 4001, a memory 4002, and a communication unit 4003. These components communicate through one or more buses. Those skilled in the art will understand that the structure of the main control module 1011 shown in the figure does not constitute a limitation on the embodiments of this application. It can be a bus topology or a star topology, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0097] The communication unit 4003 is used to establish a communication channel, enabling the main control module 1011 to communicate with other modules. For example... Figure 5 As shown, the main control module 1011 is connected to the DC module 103, the host BMS 1012 and the parallel interface 106 in the host through the communication line connected by the communication unit 4003. The parallel interface 106 in the host is also connected to the parallel interface 106 in the slave through the parallel cable. The parallel interface in the slave is connected to the slave BMS.

[0098] The processor 4001 in the main control module 1011 serves as the control center of the main control module 1011. It connects various parts of the entire device via various interfaces and lines, and executes software programs, instructions, and / or modules stored in the memory 4002, as well as calling data stored in the memory, to perform various functions of the host and / or process data. The processor 4001 can be composed of integrated circuits (ICs), such as a single packaged IC or multiple packaged ICs with the same or different functions connected together. For example, the processor 4001 may include a central processing unit (CPU), a microcontroller unit (MCU), etc.

[0099] The memory 4002 is used to store the execution instructions of the processor 4001. The memory 4002 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. When the execution instructions in the memory 4002 are executed by the processor 4001, the energy storage device is able to perform the charging power distribution method in the embodiments of the present invention.

[0100] In a specific implementation, this application also provides a computer storage medium, wherein the computer storage medium may store a program, which, when executed, may include some or all of the steps of the charging power allocation method provided in this application. The storage medium may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0101] In a specific implementation, this application also provides a computer program product, wherein the computer program product includes executable instructions, which, when executed on a computer, cause the computer to perform some or all of the steps of the charging power distribution method provided in this application.

[0102] This application also provides a non-transitory computer-readable storage medium that stores computer instructions, which cause the computer to execute the charging power distribution method provided in this application.

[0103] The aforementioned non-transitory computer-readable storage medium may be any combination of one or more computer-readable media. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or flash memory, optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in connection with an instruction execution system, apparatus, or device.

[0104] Those skilled in the art will clearly understand that the techniques in the embodiments of this application can be implemented using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions in the embodiments of this application, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device to execute the methods described in various embodiments or certain parts of the embodiments of this application.

[0105] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. A charging power distribution method for energy storage devices, characterized in that, The energy storage device includes an energy storage battery, and the method includes: Determine the current charging power requirements of the energy storage battery; Determine the current state of charge of the energy storage battery; The target power level corresponding to the current state of charge of the energy storage battery is determined; wherein, the power level is pre-divided according to the state of charge of the battery, and different power levels correspond to different charging power allocation strategies. According to the target charging power allocation strategy corresponding to the target power level, a target charging method is selected from high-voltage photovoltaic, low-voltage photovoltaic and AC mains charging methods, and charging power is allocated to the target charging method according to the current charging power demand of the energy storage battery. The energy storage battery is charged according to the target charging method.

2. The method according to claim 1, characterized in that, The battery capacity is pre-classified according to its state of charge, and different charging power allocation strategies correspond to different capacity levels, including: Based on the order of battery state of charge from low to high, at least three battery levels are defined: first battery level, second battery level, and third battery level. In the first power level, high-voltage photovoltaic charging method has a higher priority than low-voltage photovoltaic charging method, and low-voltage photovoltaic charging method has a higher priority than AC mains charging method. In the second power level, high-voltage photovoltaic charging is prohibited, and low-voltage photovoltaic charging has a higher priority than AC mains charging. In the third power level, high-voltage photovoltaic and low-voltage photovoltaic charging methods are prohibited, and only AC mains charging is supported.

3. The method according to claim 1, characterized in that, Determining the current charging power requirement of the energy storage battery includes: Determine the current maximum allowable charging power of the energy storage battery; Determine the current battery state parameters of the energy storage battery, including: battery state of charge, battery temperature, and voltage; The correction coefficient is determined based on the current battery state parameters of the energy storage battery; The maximum allowable charging power is corrected according to the correction coefficient to obtain the current charging power requirement of the energy storage battery.

4. The method according to claim 3, characterized in that, The step of determining the correction coefficient based on the current battery state parameters of the energy storage battery includes: The first correction factor is determined based on the current state of charge of the energy storage battery. The second correction factor is determined based on the current battery temperature of the energy storage battery; The third correction factor is determined based on the current voltage of the energy storage battery; The correction coefficient is determined based on the first correction factor, the second correction factor, and the third correction factor.

5. The method according to claim 4, characterized in that, The step of determining the first correction factor based on the current state of charge of the energy storage battery includes: The value of the first correction factor is determined according to the value range of the current state of charge of the energy storage battery. Different state of charge value ranges correspond to different first correction factors. The closer the current state of charge of the energy storage battery is to a full charge, the smaller the value of the first correction factor.

6. The method according to claim 4, characterized in that, The step of determining the second correction factor based on the current battery temperature of the energy storage battery includes: When the current battery temperature of the energy storage battery is within a preset first temperature range, the second correction factor takes the first value. When the current battery temperature of the energy storage battery is in a second temperature range that is less than the first temperature range or in a third temperature range that is greater than the first temperature range, the value of the second correction factor is the second value. Otherwise, the second correction factor takes the third value; Wherein, the first value is greater than the second value, and the second value is greater than the third value.

7. The method according to claim 4, characterized in that, The step of determining the third correction factor based on the current voltage of the energy storage battery includes: When the current voltage of the energy storage battery is within a preset first voltage range, the third correction factor takes the fourth value; When the current voltage of the energy storage battery is in a second voltage range that is greater than the first voltage range, the third correction factor takes the fifth value; When the current voltage of the energy storage battery is in the third voltage range or the fourth voltage range, the third correction factor is set to the sixth value. The voltages in the third voltage range are all less than the first threshold, the voltages in the fourth voltage range are all greater than the second threshold, the first threshold is less than the minimum value in the first voltage range, and the second threshold is greater than the maximum value in the second voltage range. The fourth value is greater than the fifth value, and the fifth value is greater than the sixth value.

8. The method according to claim 1, characterized in that, The step of allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method includes high-voltage photovoltaic and low-voltage photovoltaic charging methods, determine the high-voltage photovoltaic charging capacity and the low-voltage photovoltaic charging capacity. Based on the high-voltage photovoltaic charging capability and the low-voltage photovoltaic charging capability, a first total available photovoltaic charging power is determined; Based on the high-voltage photovoltaic charging capacity and the low-voltage photovoltaic charging capacity, determine the high-voltage photovoltaic charging allocation ratio and the low-voltage photovoltaic charging allocation ratio; The charging power allocated to the high-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery, the first total available photovoltaic charging power, and the high-voltage photovoltaic charging allocation ratio. The charging power allocated to the low-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery, the first total available photovoltaic charging power, and the low-voltage photovoltaic charging allocation ratio.

9. The method according to claim 1, characterized in that, The step of allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method supports only low-voltage photovoltaic charging, the low-voltage photovoltaic charging capability is determined. The charging power allocated to the low-voltage photovoltaic charging method is determined based on the current charging power demand of the energy storage battery and the low-voltage photovoltaic charging capability.

10. The method according to claim 1, characterized in that, The step of allocating charging power to the target charging method based on the current charging power demand of the energy storage battery includes: When the target charging method includes AC mains charging, the second total available photovoltaic charging power is determined based on the high-voltage photovoltaic charging capacity and / or the low-voltage photovoltaic charging capacity. The charging power allocated for AC mains charging is determined based on the difference between the current charging power demand of the energy storage battery and the second total available photovoltaic charging power.

11. The method according to claim 1, characterized in that, After allocating charging power to the target charging method according to the current charging power demand of the energy storage battery, the method further includes: Determine the power difference between the charging power currently allocated to the target charging method and the actual charging power of the target charging method. Based on the power difference, determine the value of the power speed limit; Based on the current actual charging power of the target charging method and the value of the power speed limit, the final charging power allocated to the target charging method is determined.

12. An energy storage device, characterized in that, include: Energy storage battery, control module, high-voltage photovoltaic charging interface, low-voltage photovoltaic charging interface and AC mains charging interface; The control module is used to execute the charging power distribution method for energy storage devices as described in any one of claims 1 to 11.

13. The energy storage device according to claim 12, characterized in that, The energy storage device includes a host, a slave, and a parallel cable; the host is used to control the DC conversion module to distribute charging power according to the charging power distribution method, the host and the slave are electrically connected by the parallel cable, and the slave is charged through the parallel cable.

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