Energy storage device, power control method, storage medium, and program product

Abstract

The application provides an energy storage device, a power control method, a storage medium and a program product. The energy storage device comprises an energy storage unit, a power unit and a power controller. The energy storage unit comprises an energy storage battery cluster and a first PCS. The power unit comprises a power battery cluster and a second PCS. The peak charge-discharge rate of the power battery cluster is greater than the rated charge-discharge rate of the energy storage battery cluster. The power controller is in communication connection with the first PCS and the second PCS. The power controller is configured to perform the following: acquiring first state parameters corresponding to the energy storage battery cluster through the first PCS; acquiring second state parameters corresponding to the power battery cluster through the second PCS; based on external power demand, the first state parameters and the second state parameters, generating and issuing independent power control instructions to the first PCS and the second PCS to control the power output or input of the energy storage battery cluster and the power battery cluster. The service life of the energy storage device is relatively high.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an energy storage device, a power control method, a storage medium, and a program product. Background Technology

[0002] Energy storage devices can help to smooth out peak and valley loads in the power grid, maintain grid stability, and meet the distributed power load demand of the grid when the new load on the grid is small.

[0003] In related technologies, energy storage devices typically rely on energy storage batteries to operate. Specifically, to meet the requirements of long-term charge-discharge capabilities, energy storage devices usually use high-capacity, low-rate energy storage batteries. However, with the continuous development of energy storage technology, there may be a need for energy storage devices to provide instantaneous response capabilities. When the required instantaneous response capability exceeds its energy storage capacity, the energy storage device will often provide a higher instantaneous response capability through brief overcurrent, which will lead to a reduction in the lifespan of the energy storage battery, resulting in a shorter lifespan for the energy storage device. Summary of the Invention

[0004] The purpose of this application is to provide an energy storage device, a power control method, a storage medium, and a program product to solve the technical problems described above.

[0005] In a first aspect, embodiments of this application provide an energy storage device, including: an energy storage unit, a power unit, and a power controller. The energy storage unit includes an energy storage battery cluster and a first PCS. The DC side of the first PCS is electrically connected to the energy storage battery cluster for bidirectional energy transfer between the energy storage battery cluster and an external device. The power unit includes a power battery cluster and a second PCS. The DC side of the second PCS is electrically connected to the power battery cluster for bidirectional energy transfer between the power battery cluster and an external device. The peak charge / discharge rate of the power battery cluster is greater than the rated charge / discharge rate of the energy storage battery cluster. The power controller is communicatively connected to both the first PCS and the second PCS. The power controller is configured to: acquire a first state parameter corresponding to the energy storage battery cluster through the first PCS; acquire a second state parameter corresponding to the power battery cluster through the second PCS; and generate and issue independent power control commands to the first PCS and the second PCS based on external power demand, the first state parameter, and the second state parameter, to control the power output or input of the energy storage battery cluster and the power battery cluster. This can improve the service life and reliability of the energy storage device.

[0006] Optionally, the energy storage battery cluster and the power battery cluster are connected in parallel to the same DC bus in a string configuration via their respective PCS, and the DC bus is connected to the power controller. This facilitates adaptive power control of each battery cluster based on its different characteristics. Furthermore, if a battery cluster fails or is damaged, it reduces the risk of fault propagation, thereby improving the safety of the energy storage device. Additionally, during power switching control, it mitigates the impact of instantaneous surges on the energy storage battery cluster and voltage fluctuations on the DC bus, contributing to smooth power switching and ensuring the stability of the energy storage device.

[0007] Optionally, the first state parameter includes a first power corresponding to the current energy storage battery cluster, the second state parameter includes a second power corresponding to the current power battery cluster, and the power controller is configured to perform: determining the total power of the energy storage device based on the first power and the second power; controlling the power battery cluster to support the power demand of the external device when the total power does not meet the balance requirement; and controlling the energy storage battery cluster to support the power demand of the external device when the power battery cluster is insufficient to support the power demand of the external device. In this way, when the total power of the energy storage device does not meet the balance requirement, the power battery cluster can be controlled to support the power demand first, thus providing a faster and higher instantaneous response capability to meet the higher instantaneous demand of the external device. Conversely, when the power battery cluster is insufficient to support the power demand, the energy storage battery cluster can be controlled to support the higher instantaneous demand of the external device, reducing the power impact on the external device.

[0008] Optionally, the power controller is configured to perform the following: during the process of the power battery cluster supporting the power demand of the external device, if the total power meets the balance requirement, determine the rate of decrease of the power supported by the power battery cluster; based on the rate of decrease, determine the power reduction of the power battery cluster in the next cycle; determine the safe power variation range of the energy storage battery cluster; control the power battery cluster to reduce the power it supports according to the reduced power gradient; and control the energy storage battery cluster to support the reduced power of the power battery cluster within the safe power variation range.

[0009] In this way, if the total power meets the balance requirements while the power battery cluster supports the power demand of external equipment, the power reduction in the next cycle can be dynamically determined based on the rate of decrease in the power supported by the power battery cluster. This allows for dynamic control of the power battery cluster to reduce its supported power in a cyclical gradient, and adaptive control of the energy storage battery cluster to support the reduced power within its safe power variation range. This improves the instantaneous response capability of the power battery cluster to cope with subsequent higher instantaneous power demands and, to some extent, helps to extend the lifespan of the energy storage device. Furthermore, the cyclical gradient reduction of the power required by the power battery cluster also helps to mitigate current surges in the power battery cluster and the second PCS, while also allowing for a smooth power transition as the power gradient of the energy storage battery cluster increases. This also helps to mitigate sudden changes in bus voltage and frequency.

[0010] Optionally, the first state parameter further includes the first maximum charge / discharge power, the first operating state parameter, and the first state of charge (SOC) corresponding to the energy storage battery cluster; the second state parameter further includes the second state of charge (SOC) corresponding to the power battery cluster; and the power controller is configured to perform: determining the power adjustable range corresponding to the energy storage battery cluster based on the first power and the first maximum charge / discharge power of the energy storage battery cluster; and adjusting the power adjustable range based on the first operating state parameter, the difference between the first SOC and the second SOC, to obtain the power safe variation range.

[0011] In this way, the adjustable power range of the energy storage battery cluster is determined based on its relevant parameters, and the adjustable power range is adjusted based on its current state and SOC condition, thereby obtaining the safe power variation range of the energy storage battery cluster. When the energy storage battery cluster is controlled to assist based on the safe power variation range, the safety of the energy storage battery cluster is improved on the one hand, and it also helps to balance the response capabilities between the energy storage battery cluster and the power battery cluster on the other hand, thereby helping to improve the service life of the energy storage equipment.

[0012] Optionally, the first state parameter includes a first SOC, and the second state parameter includes a second SOC. The power controller is configured to perform the following: determining a first power weight for the energy storage battery cluster and a second power weight for the power battery cluster based on the levels of the first and second SOCs; wherein the first power weight is positively correlated with the first SOC, and the second power weight is positively correlated with the second SOC; and controlling the power output or input of the energy storage battery cluster and the power battery cluster according to the first and second power weights. In this way, by controlling the SOC levels of the battery clusters, it is possible to control the battery clusters with higher SOCs to support more power, while allowing the battery clusters with lower SOCs to support less power, thereby contributing to both load balancing and state maintenance.

[0013] Optionally, the first state parameter includes a first SOC, and the second state parameter includes a second SOC. The power controller is configured to: if the first SOC is less than a first preset SOC, control the energy storage battery cluster to pause power output or input; if the second SOC is less than a second preset SOC, control the power battery cluster to pause power output or input. In this way, when the SOC is less than the corresponding preset SOC, the power controller can control the corresponding battery cluster to pause power output, thereby achieving a more balanced SOC among the battery clusters. This helps to improve the lifespan of the energy storage device.

[0014] Optionally, the power controller is configured to perform the following: acquire the maximum instantaneous power required by the external device and the duration of operation at the maximum instantaneous power; determine the maximum power that the energy storage device can provide during the duration without a power unit; determine the power deficit of the energy storage device based on the maximum instantaneous power and the maximum power; determine whether the power units currently included in the energy storage device meet the power requirements based on the power deficit and the output power of the power unit; and prompt the user to adjust the power units if the currently included power units cannot meet the power requirements. This allows for determination of whether the power units currently included in the energy storage device can meet the power requirements, providing a prompt when they do not, facilitating operator adjustment of the power units to ensure that the adjusted power units provide instantaneous response capability to meet power requirements, which also helps to improve the lifespan of the energy storage battery to some extent.

[0015] Optionally, the power battery cluster and the energy storage battery cluster satisfy one or more of the following conditions: identical electrochemical systems; identical cycle life. This balances the lifespan and economic efficiency of the energy storage device.

[0016] Secondly, embodiments of this application provide a power control method applicable to energy storage devices. The energy storage device includes an energy storage unit, a power unit, and a power controller. The energy storage unit includes an energy storage battery cluster and a first PCS. The DC side of the first PCS is electrically connected to the energy storage battery cluster for bidirectional energy transfer between the energy storage battery cluster and an external device. The power unit includes a power battery cluster and a second PCS. The DC side of the second PCS is electrically connected to the power battery cluster for bidirectional energy transfer between the power battery cluster and an external device. The peak charge / discharge rate of the power battery cluster is... The power controller is communicatively connected to the first PCS and the second PCS respectively, and the power control method is executed by the power controller. The method includes: obtaining a first state parameter corresponding to the energy storage battery cluster through the first PCS; obtaining a second state parameter corresponding to the power battery cluster through the second PCS; generating and issuing independent power control commands to the first PCS and the second PCS based on external power demand, the first state parameter and the second state parameter, so as to control the power output or input of the energy storage battery cluster and the power battery cluster.

[0017] Thirdly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the method provided in the first aspect above.

[0018] Fourthly, embodiments of this application provide a computer program product including a computer program or instructions that, when executed by a processor, perform the method described in the first aspect.

[0019] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing embodiments of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an energy storage device provided in an embodiment of this application;

[0022] Figure 2 This is a flowchart of a power control method provided in an embodiment of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. 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] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] It should be noted that, unless otherwise specified, the embodiments or technical features in the embodiments of this application may be combined.

[0026] In related technologies, energy storage devices often use short-term overcurrent to provide high instantaneous response capabilities, resulting in a shorter lifespan for the energy storage battery. In other words, energy storage devices improve instantaneous response capabilities by sacrificing battery lifespan. For example, when the instantaneous power demand of an external device exceeds the battery's design rate, the device forces the battery to charge and discharge at a current far exceeding its rated standard for a short period. This exacerbates cell heat generation, and high temperatures accelerate side reactions such as electrolyte decomposition and phase transition degradation of the positive and negative electrode materials, leading to permanent capacity decay. Furthermore, charging and discharging beyond the design rate also intensifies chemical reactions, causing cracks and pulverization of electrode material particles, damaging the electrode structure, and reducing battery cycle life. Therefore, this results in a shorter battery lifespan, and consequently, a shorter lifespan for the energy storage device.

[0027] To address this problem, this application provides an energy storage device, a power control method, a storage medium, and a program product. Specifically, this application partially replaces the energy storage battery clusters in the energy storage device with power battery clusters. This allows the power battery clusters to leverage their inherent low-capacity, high-rate characteristics to provide higher instantaneous response capabilities, thereby meeting the high instantaneous power demands of external devices. Furthermore, the energy storage device can adaptively control the power of both the energy storage battery clusters and the power battery clusters while meeting the power demands of external devices. This allows the energy storage device to control the power battery clusters to output or input more power when a high instantaneous response capability is needed, and to reduce or suspend the power output or input power of the power battery clusters when a high instantaneous response capability is not required, allowing the energy storage battery clusters to handle the output or input. This mitigates the problem of transient overcurrent in the energy storage batteries while meeting the power demands of external devices, thus contributing to an extended lifespan for both the energy storage batteries and the energy storage device. Moreover, dynamically controlling the power of both the energy storage battery clusters and the power battery clusters allows them to operate according to their own characteristics, reducing damage to both and further contributing to an extended lifespan for the energy storage device.

[0028] It should be noted that the defects in the solutions in the above-mentioned related technologies were discovered by the inventors after long-term practice and careful research. Therefore, the discovery process of the above-mentioned problems and the solutions proposed by the embodiments of the present invention in the following text should all be contributions made by the inventors to the present invention during the process of the present invention.

[0029] Please see Figure 1 The diagram illustrates a structural schematic of an energy storage device provided in an embodiment of this application. Figure 1 As shown, the energy storage device includes an energy storage unit, a power unit, and a power controller.

[0030] The energy storage unit includes an energy storage battery cluster and a first PCS. The DC side of the first PCS is electrically connected to the energy storage battery cluster and is used for bidirectional energy transfer between the energy storage battery cluster and external devices.

[0031] The aforementioned energy storage battery cluster is a functional unit in an energy storage device that can be charged and discharged independently. It can be composed of multiple energy storage battery modules connected in series and parallel.

[0032] The aforementioned first PCS (Power Conversion System, or PCS for short) is also the first energy storage converter.

[0033] The aforementioned external devices may include external loads or external power sources. When the external device is an external load (e.g., an electrical appliance), the energy storage battery cluster supplies energy to the outside; when the external device is a power source (e.g., a photovoltaic power source), the energy storage battery cluster supplies energy to the inside.

[0034] In addition, the power unit includes a power battery cluster and a second PCS. The DC side of the second PCS is electrically connected to the power battery cluster for bidirectional energy transfer between the power battery cluster and external devices. The peak charge / discharge rate of the power battery cluster is greater than the rated charge / discharge rate of the energy storage battery cluster.

[0035] The aforementioned power battery cluster is a functional unit in energy storage devices that can be charged and discharged independently, and can be composed of multiple power battery modules connected in series and parallel.

[0036] The aforementioned second PCS (Power Conversion System, or PCS for short) is also the second energy storage converter.

[0037] In addition, when the external device is an external load, the power battery cluster delivers energy outward; when the external device is a power source, the power battery cluster inputs energy inward.

[0038] It is understandable that those skilled in the art can install power batteries in the locations originally intended for energy storage batteries within an energy storage device, without making or adapting other structural adjustments. Knowing that the energy storage battery clusters in an energy storage device can be partially replaced with power battery clusters, they can achieve the installation without any inventive effort, thereby obtaining an energy storage device comprising both energy storage battery clusters and power battery clusters.

[0039] In some optional implementations, the energy storage battery cluster and the power battery cluster are connected in parallel to the same DC bus in a string configuration via their respective PCS, and the DC bus is connected to the power controller. This allows each battery cluster to respond to power independently. Firstly, it facilitates adaptive power control of each battery cluster based on its different characteristics. Secondly, if a battery cluster fails or is damaged, it reduces the risk of fault propagation, thereby improving the safety of the energy storage device. Furthermore, during power switching control, it also mitigates the impact of instantaneous surges on the energy storage battery cluster and voltage fluctuations on the DC bus, contributing to smooth power switching and ensuring the stability of the energy storage device.

[0040] Furthermore, the power controller is communicatively connected to both the first PCS and the second PCS; the power controller is configured to execute a power control method. Please refer to [link to relevant documentation] here. Figure 2It illustrates a flowchart of a power control method performed by a power controller according to an embodiment of this application, such as... Figure 2 As shown, the method includes steps 201 to 203:

[0041] Step 201: Obtain the first state parameters corresponding to the energy storage battery cluster through the first PCS;

[0042] The aforementioned first state parameters may include, for example, parameters that are substantially related to the energy storage battery cluster, such as power, voltage, current, and temperature.

[0043] In some application scenarios, the energy storage battery cluster may include a battery cluster management unit (i.e., cluster-level BMS), which can collect the first state parameters corresponding to the energy storage battery cluster, and then send them to the first PCS. The first PCS then forwards them to the power controller so that the power controller can obtain the first state parameters.

[0044] Step 202: Obtain the second state parameters corresponding to the power battery cluster through the second PCS;

[0045] The aforementioned second state parameters may include, for example, parameters that are substantially related to the power battery cluster, such as power, voltage, current, and temperature.

[0046] In some application scenarios, the power battery cluster may also include a battery cluster management unit (i.e., cluster-level BMS), which can collect the second state parameters corresponding to the power battery cluster, and then send them to the second PCS, and then forward them to the power controller through the second PCS, so that the power controller can obtain the second state parameters.

[0047] Step 203: Based on the external power demand, the first state parameter, and the second state parameter, generate and issue independent power control commands to the first PCS and the second PCS to control the power output or input of the energy storage battery cluster and the power battery cluster.

[0048] The aforementioned external power requirements can be considered as the power requirements of external devices;

[0049] In some application scenarios, the power controller can, for example, when the power demand of an external device exceeds a first preset threshold, generate and issue independent power control commands to the first and second PCS based on first state parameters such as the maximum output power, temperature, and SOC of the energy storage battery cluster, and second state parameters such as the maximum output power, temperature, and SOC of the power battery cluster, to control both the power battery cluster and the energy storage battery cluster to operate at their respective maximum available output power. Alternatively, when the power demand of an external device is between the first and second preset thresholds, the controller can generate and issue independent power control commands to the first and second PCS to control the power battery cluster to operate at its current maximum available output power and to pause the energy storage battery cluster's power output. Or, when the power demand of an external device is less than the second preset threshold, the controller can generate and issue independent power control commands to the first and second PCS to control the power battery cluster to pause its power output and control the energy storage battery cluster to operate at its maximum output power. The aforementioned first and second preset thresholds can be set according to actual needs. For example, they can be set based on the maximum output power of the power battery cluster and the maximum output power of the energy storage battery cluster. Specifically, for example, when the maximum output power of the power battery cluster is 120 kW and the maximum output power of the energy storage battery cluster is 80 kW, the first preset threshold can be set to 150 kW and the second preset threshold can be set to 40 kW.

[0050] In this implementation, since the energy storage device includes both energy storage battery clusters and power battery clusters, it can leverage the low-capacity, high-rate characteristics of the power battery clusters to provide high instantaneous response capabilities, thereby meeting the high instantaneous power demands of external devices. Furthermore, based on the power requirements of external devices and according to the relevant parameters of the energy storage battery clusters and power battery clusters, the energy storage device can adaptively control the power output or input of the energy storage battery clusters. This allows the energy storage device to control the power battery clusters to output or input more power when high instantaneous response is required, and to reduce or suspend the power output or input of the power battery clusters when high instantaneous response is not needed, transferring the output or input to the energy storage battery clusters. This mitigates the problem of transient overcurrent in the energy storage batteries while meeting the power demands of external devices, thereby extending the lifespan of the energy storage batteries and ultimately the lifespan of the energy storage device. Moreover, dynamically controlling the power of the energy storage battery clusters and power battery clusters based on their relevant parameters allows them to operate according to their own characteristics, reducing damage to both and further contributing to the extended lifespan of the energy storage device.

[0051] Furthermore, each PCS only needs to receive and execute explicit power control commands, which simplifies the control complexity of each battery cluster and improves the reliability of the energy storage device.

[0052] It should be noted that the power controller can execute the above power control method periodically or in real time, thus capturing the instantaneous power demand of external devices and meeting their power requirements in a timely manner. Alternatively, the power controller can also execute the above power control method based on internal commands (such as power setpoint change commands) or external commands (such as grid commands). This allows it to respond to external commands while adapting to changes in internal power requirements, thereby improving the flexibility of energy storage devices.

[0053] In some optional implementations, the first state parameter includes the first power currently corresponding to the energy storage battery cluster, and the second state parameter includes the second power currently corresponding to the power battery cluster. Here, it can be understood that energy storage devices can typically output power to an external load or input power from an external power source. Therefore, depending on the external device, the energy storage device can output power or input power. Consequently, the aforementioned first power may include either the first output power or the first input power currently corresponding to the energy storage battery cluster. The aforementioned second power may include either the second output power or the second input power currently corresponding to the power battery cluster.

[0054] Thus, when the power controller controls the power of the energy storage battery cluster and the power battery cluster based on the first state parameter and the second state parameter, it can be specifically configured to perform the following steps:

[0055] Sub-step 2031: Determine the total power of the energy storage device based on the first power and the second power; for example, the first output power and the second output power can be added together to obtain the total output power of the energy storage device; or, the first input power and the second input power can be added together to obtain the total input power of the energy storage device.

[0056] Sub-step 2032: If the total power does not meet the balance requirements, control the power battery cluster to support the power demand of the external device;

[0057] The aforementioned balance requirement can be viewed as ensuring that the power demand of external devices remains essentially constant. In this case, the energy storage device can be considered to meet the power demand of the external devices. In some application scenarios, for example, the total power of the energy storage device can be subtracted from the power demand of the external devices, and the balance requirement can be determined based on this difference. For instance, if the difference (absolute value) is greater than a power deviation threshold (e.g., 1% of the rated power of the energy storage device), the current total power can be considered not to meet the balance requirement. If the difference is not greater than the power deviation threshold, the current total power can be considered to meet the balance requirement. Here, the introduction of a power deviation threshold can reduce the frequent adjustments of the power controller due to small fluctuations near the balance point, improving control stability. It also improves the fault tolerance of the control to a certain extent, making the control logic clear and reliable.

[0058] Subsequently, if the total power does not meet the balance requirements, the power controller can first control the power battery cluster to output power to the external load or input power supplied by the external power source to support the power demand of the external equipment.

[0059] Sub-step 2033: If the power battery cluster is insufficient to support the power demand of the external device, control the energy storage battery cluster to support the power demand of the external device as well.

[0060] Here, it's understandable that in real-world scenarios, the needs of external devices must typically be met first, followed by consideration of the energy storage device's own capabilities. Therefore, to meet the power demands of external devices, the energy storage battery cluster can be controlled to provide additional power when the main battery pack is insufficient. For example, if an external device requires 50kW of input power, but the main battery pack can only output 45kW, the energy storage battery cluster can be controlled to output 5kW to avoid affecting the normal operation of the external device.

[0061] In this implementation, when the total power of the energy storage device does not meet the balance requirements, the power battery cluster can be controlled to support the power demand first, so as to provide a higher instantaneous response capability quickly and meet the higher instantaneous demand of external devices. When the power battery cluster is insufficient to support the power demand, the energy storage battery cluster can be controlled to support the higher instantaneous demand of external devices as well, reducing the power impact on external devices.

[0062] In some application scenarios, the power controller can be specifically configured to perform the following steps: when the deviation between the maximum power that the power battery cluster can currently support and the power demand of the external device is less than a power deviation threshold, control the energy storage battery cluster to support the power demand of the external device.

[0063] In other words, if the power controller determines that when the power battery cluster operates at its maximum power alone, the deviation between that maximum power and the power demand of the external device is still greater than the power deviation threshold (as described above, and will not be repeated here), then it can be determined that the power battery cluster operating alone cannot make the total power of the energy storage device meet the balance requirements and cannot meet the power demand of the external device. In this case, it can control the energy storage battery cluster to assist in providing response capability so as to meet the power demand of the external device.

[0064] In this implementation, considering the need to meet the power requirements of external devices as much as possible, if it is determined that the power battery cluster alone cannot meet the power requirements even when operating at its maximum power, the energy storage battery cluster can be controlled to assist, thereby reducing the impact on external devices.

[0065] Understandably, if the power controller determines that the total power of the energy storage device can meet the balance requirements when the power battery cluster operates at its maximum power alone, thereby meeting the power demand of the external device, then it can control the power battery cluster to operate alone without controlling the energy storage battery cluster to assist, which to some extent helps to improve the service life of the energy storage battery.

[0066] In some alternative implementations, the power controller can be configured to: while the power battery cluster is supporting the power demands of external devices, if the total power meets the balance requirements, reduce the power supported by the power battery cluster and increase the power supported by the energy storage battery cluster, thereby preserving the instantaneous response capability of the power battery cluster to cope with subsequent higher instantaneous power demands. Specifically, the power controller can be configured to perform the following steps:

[0067] Step A: In the process of the power battery cluster supporting the power demand of the external device, if the total power meets the balance requirement, determine the rate of decrease of the power supported by the power battery cluster.

[0068] In some application scenarios, the descent rate can be determined according to a preset descent rule. For example, within 10 seconds when the total power meets the balance requirement, a preset 10kW / s can be determined as the descent rate; within 20 seconds when the total power meets the balance requirement, a preset 20kW / s can be determined as the descent rate.

[0069] In other application scenarios, the descent rate can also be determined by combining a power deviation threshold. For example, if the power deviation threshold is within a first preset range, the descent rate corresponding to the first preset range can be obtained. If the power deviation threshold is within a second preset range, the descent rate corresponding to the second preset range can be obtained. It is understood that the aforementioned first and second preset ranges can be set according to actual needs, and this application does not impose any restrictions on them.

[0070] Step B: Determine the power reduction of the battery cluster in the next cycle based on the rate of decrease; for example, the rate of decrease can be multiplied by the cycle duration to obtain the power reduction in the next cycle.

[0071] Step C: Determine the safe power variation range of the energy storage battery cluster;

[0072] In some optional implementations, the first state parameter may further include the first maximum charge / discharge power, the first operating state parameter, and the first SOC corresponding to the energy storage battery cluster, and the second state parameter may further include the second SOC corresponding to the power battery cluster.

[0073] In this way, the power controller can be specifically configured to perform the following steps:

[0074] Step 1: Determine the adjustable power range of the energy storage battery cluster based on its current first power and first maximum charge / discharge power.

[0075] In some application scenarios, the power controller can, for example, use a first power as a base value, and then subtract the first maximum charging power and the first maximum discharging power from the first power, respectively, and use the two differences as the endpoint values ​​of the power adjustable range, thus obtaining the aforementioned power adjustable range.

[0076] Step 2: Based on the first operating state parameter and the difference between the first SOC and the second SOC, adjust the adjustable power range to obtain the safe power variation range.

[0077] The aforementioned first operating state parameters may include, for example, parameters characterizing charging or discharging, such as current parameters, voltage parameters, and other parameters that can be used to determine charging or discharging. Based on the first operating state parameters, the power controller can determine whether the energy storage battery cluster is currently charging or discharging, thereby determining which endpoint of the adjustable power range to adjust to reduce the risk of overcharging or over-discharging.

[0078] In some application scenarios, if the energy storage battery cluster is in a charging state and the first SOC is greater than the second SOC, the upper limit of the adjustable power range can be reduced; if the energy storage battery cluster is in a discharging state and the first SOC is less than the second SOC, the lower limit of the adjustable power range can be reduced.

[0079] In this implementation, the adjustable power range of the energy storage battery cluster is determined based on its relevant parameters, and the adjustable power range is adjusted based on its current state and SOC status to obtain the safe power variation range of the energy storage battery cluster. When the energy storage battery cluster is controlled to assist based on this safe power variation range, the safety of the energy storage battery cluster is improved on the one hand, and it also helps to balance the response capabilities between the energy storage battery cluster and the power battery cluster on the other hand, thereby helping to improve the service life of the energy storage device.

[0080] Step D involves controlling the power battery cluster to reduce the supported power according to the reduced power gradient, and controlling the energy storage battery cluster to support the reduced power of the power battery cluster within the power safety variation range.

[0081] In other words, the power battery cluster reduces its power in each cycle to achieve a power gradient reduction. Then, within the safe power variation range of the energy storage battery cluster, the energy storage battery cluster is controlled to output or input the reduced power of the power battery cluster in the corresponding cycle, so that the total power of the energy storage device can meet the power requirements of the external device.

[0082] It is understandable that if the power reduction of the power battery cluster exceeds the upper limit of the safe power variation range of the energy storage battery cluster, the power battery cluster can continue to operate at its current power, thereby reducing the degree of damage to the lifespan of the energy storage battery cluster.

[0083] In this implementation, if the total power meets the balance requirements while the power battery cluster supports the power demand of external devices, the power reduction in the next cycle can be dynamically determined based on the rate of decrease in the power supported by the power battery cluster. This allows for dynamic control of the power battery cluster to reduce its supported power in a cyclical gradient, and adaptive control of the energy storage battery cluster to support the reduced power within its safe power variation range. This improves the instantaneous response capability of the power battery cluster to cope with subsequent higher instantaneous power demands and, to some extent, helps extend the lifespan of the energy storage device. Furthermore, the cyclical gradient reduction of the power required by the power battery cluster also helps mitigate current surges to the power battery cluster and the second PCS, while providing response time for power gradient increases in the energy storage battery cluster, allowing for a smooth power transition. This also helps mitigate sudden changes in bus voltage and frequency.

[0084] In some optional implementations, the first state parameter includes a first SOC, the second state parameter includes a second SOC, and the power controller is configured to perform: determining a first power weight for the energy storage battery cluster and a second power weight for the power battery cluster based on the high or low values ​​of the first SOC and the second SOC; wherein the first power weight is positively correlated with the first SOC, and the second power weight is positively correlated with the second SOC; and controlling the power output or input of the energy storage battery cluster and the power battery cluster according to the first power weight and the second power weight.

[0085] In some application scenarios, for example, the difference or quotient between the first SOC and the second SOC can be used to determine the higher SOC. Specifically, if the first SOC is higher than the second SOC, the first power weight can be set to be greater than the second power weight; if the first SOC is lower than the second SOC, the first power weight can be set to be less than the second power weight; if the first SOC is equal to the second SOC, the first power weight can be set to be equal to the second power weight.

[0086] Furthermore, for example, the first power weight can be multiplied by the current power of the energy storage battery cluster to obtain its output or input power. Similarly, the second power weight can be multiplied by the current power of the power battery cluster to obtain its output or input power.

[0087] In this implementation, by controlling the SOC levels of battery clusters, it is possible to control the power output of battery clusters with higher SOC levels to be supported, while allowing battery clusters with lower SOC levels to support less power output. This helps to achieve both load balancing and state maintenance.

[0088] In some optional implementations, the first state parameter includes a first SOC, the second state parameter includes a second SOC, and the power controller is configured to perform the following: if the first SOC is less than a first preset SOC, control the energy storage battery cluster to pause output or input power; if the second SOC is less than a second preset SOC, control the power battery cluster to pause output or input power.

[0089] The aforementioned first preset SOC can be, for example, 20% or 25% of the rated SOC of the energy storage battery cluster.

[0090] The aforementioned second preset SOC can be, for example, 20% or 25% of the rated SOC of the power battery pack.

[0091] Subsequently, when the SOC is less than the corresponding preset SOC, the power controller can control the corresponding battery cluster to pause power support, so as to make the SOC among the battery clusters more balanced. This helps to improve the service life of energy storage devices.

[0092] In some application scenarios, if the first SOC is less than the first preset SOC, or the second SOC is less than the second preset SOC, even if the external device still has power requirements, the power of the corresponding energy storage battery cluster or power battery cluster can be limited, an alarm can be issued, and other battery clusters can be forcibly controlled to provide support. This can also help improve the service life of energy storage devices to some extent.

[0093] In some alternative implementations, the power controller may also be configured to perform the following steps:

[0094] First, obtain the maximum instantaneous power required by the external device and the duration of operation at the maximum instantaneous power;

[0095] In some applications, external devices can proactively inform the user of their required maximum instantaneous power and duration. In others, these parameters can be determined through analysis of the specific application scenario. For instance, a tower crane, when lifting heavy objects, has a high instantaneous power requirement but a short duration. Therefore, by analyzing the tower crane's historical instantaneous current and voltage, its required maximum instantaneous power and duration can be determined.

[0096] Then, determine the maximum power that the energy storage device can provide during the said duration without a power unit;

[0097] In other words, the power controller can determine the maximum power that the energy storage device can provide during the aforementioned duration when its internal components consist entirely of energy storage battery clusters. For example, it can obtain the total current and total voltage of all energy storage battery clusters, and then multiply these two values ​​to determine the maximum power that can be provided.

[0098] Then, based on the maximum instantaneous power and the maximum power, the power deficit of the energy storage device is determined; for example, the power deficit can be obtained by subtracting the maximum instantaneous power from the maximum power.

[0099] Then, based on the power deficit and the output power of the power units, it is determined whether the power units currently included in the energy storage device meet the power requirements. In some application scenarios, if the number of power units is not less than the ratio of the power deficit to the output power (rounded up) of the power units, it can be determined that the power requirements are met. If the number of power units is less than the ratio of the power deficit to the output power (rounded up) of the power units, it can be determined that the power requirements are not met.

[0100] Finally, if the currently included power units cannot meet the power requirements, an option will be provided to adjust the power units. In some application scenarios, this could include prompting to adjust the number of power units or their selection.

[0101] In this implementation, it can be determined whether the power units currently included in the energy storage device can meet the power requirements. If they do not meet the requirements, a prompt can be made so that the operator can adjust the power units so that the adjusted power units can provide instantaneous response capability to meet the power requirements. This also helps to improve the service life of the energy storage battery to a certain extent.

[0102] In some optional implementations, the power battery cluster and the energy storage battery cluster satisfy one or more of the following conditions:

[0103] (1) The electrochemical systems are the same; here, the electrochemical systems of the power battery cluster and the energy storage battery cluster are the same, which can make the working voltage window and charge-discharge curve characteristics of the two basically the same, so that the cluster voltage range of the two can be basically the same, which helps to reduce the voltage difference between the clusters. This helps to improve the service life of the energy storage equipment.

[0104] (2) Same cycle life; Here, although the power battery cluster has a higher rate of return, if its cycle life is much lower than that of the energy storage battery cluster, it will become a bottleneck in the energy storage device, requiring frequent replacement and resulting in poor economic efficiency. Therefore, selecting a power battery cluster with the same or similar cycle life as the energy storage battery cluster helps to improve economic efficiency.

[0105] In some application scenarios, in addition to the above conditions, factors such as the individual cell capacity and internal resistance of the power battery cluster can also be considered. For example, a power battery cluster with a cell capacity that can achieve the maximum peak response power and a longer support time can be selected. Furthermore, a power battery cluster with the same or similar individual cell internal resistance as the energy storage battery cluster can be selected to help increase the difference between the energy storage battery cluster and the power battery cluster, thereby extending the lifespan of the energy storage device.

[0106] Those skilled in the art will understand that in the method described above, which is configured to be executed by the power controller in the specific embodiment, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0107] Based on the same inventive concept, this application also provides a power control method, which is executed by the power controller described above. The specific process can be found in the relevant content of the power controller configuration mentioned above, and will not be repeated here.

[0108] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, can perform the methods provided in the above-described method embodiments.

[0109] Based on the same inventive concept, this application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by a computer, the computer can perform the methods provided in the above-described method embodiments.

[0110] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0111] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0112] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0113] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An energy storage device, characterized in that, include: An energy storage unit, comprising an energy storage battery cluster and a first PCS, wherein the DC side of the first PCS is electrically connected to the energy storage battery cluster for bidirectional energy transfer between the energy storage battery cluster and an external device; The power unit includes a power battery cluster and a second PCS. The DC side of the second PCS is electrically connected to the power battery cluster and is used for bidirectional energy transfer between the power battery cluster and external devices. The peak charge / discharge rate of the power battery cluster is greater than the rated charge / discharge rate of the energy storage battery cluster. A power controller is communicatively connected to both the first PCS and the second PCS; the power controller is configured to perform: The first state parameter corresponding to the energy storage battery cluster is obtained through the first PCS, and the first state parameter includes the first power corresponding to the current energy storage battery cluster. The second state parameter corresponding to the power battery cluster is obtained through the second PCS, and the second state parameter includes the second power currently corresponding to the power battery cluster. Based on external power demand, the first state parameter, and the second state parameter, independent power control commands are generated and issued to the first PCS and the second PCS to control the power output or input of the energy storage battery cluster and the power battery cluster. This includes: determining the total power of the energy storage device based on the first power and the second power; controlling the power battery cluster to support the external power demand if the total power does not meet the balance requirement; controlling the energy storage battery cluster to support the external power demand if the power battery cluster is insufficient to support it; and, during the process of the power battery cluster supporting the external power demand, if the total power meets the balance requirement, determining the rate of decrease of the power supported by the power battery cluster; determining the power reduction of the power battery cluster in the next cycle based on the rate of decrease; determining the safe power variation range of the energy storage battery cluster; controlling the power battery cluster to reduce the supported power according to the reduced power gradient; and controlling the energy storage battery cluster to support the reduced power of the power battery cluster within the safe power variation range.

2. The energy storage device according to claim 1, characterized in that, The energy storage battery cluster and the power battery cluster are connected in parallel to the same DC bus in a string configuration via their respective PCS, and the DC bus is connected to the power controller.

3. The energy storage device according to claim 1 or 2, characterized in that, The first state parameters also include the first maximum charge / discharge power, first operating state parameters, and first SOC currently corresponding to the energy storage battery cluster; the second state parameters also include the second SOC currently corresponding to the power battery cluster; and The power controller is configured to perform: Based on the current first power and first maximum charge / discharge power of the energy storage battery cluster, determine the power adjustable range corresponding to the energy storage battery cluster; Based on the first operating state parameter and the difference between the first SOC and the second SOC, the adjustable power range is adjusted to obtain the safe power variation range.

4. The energy storage device according to claim 1, characterized in that, The first state parameter further includes a first SOC, and the second state parameter further includes a second SOC. The power controller is configured to perform: When controlling the energy storage battery cluster and the power battery cluster to output power, a first power weight is configured for the energy storage battery cluster and a second power weight is configured for the power battery cluster based on the first SOC and the second SOC; wherein, the first power weight is positively correlated with the first SOC and the second power weight is positively correlated with the second SOC; The power output of the energy storage battery cluster and the power battery cluster is controlled according to the first power weight and the second power weight.

5. The energy storage device according to claim 1, characterized in that, The first state parameter further includes a first SOC, and the second state parameter further includes a second SOC. The power controller is configured to perform: If the first SOC is less than the first preset SOC, then control the energy storage battery cluster to pause power output; If the second SOC is less than the second preset SOC, then the power battery cluster is controlled to pause power output.

6. The energy storage device according to claim 1, characterized in that, The power controller is configured to perform: Obtain the maximum instantaneous power required by the external device and the duration of operation at the maximum instantaneous power; Determine the maximum power that the energy storage device can provide during the said duration without a power unit; The power deficit of the energy storage device is determined based on the maximum instantaneous power and the maximum power. Based on the power deficit and the output power of the power unit, determine whether the power unit currently included in the energy storage device meets the power requirements; If the currently included power units cannot meet the power requirements, an adjustment to the power units will be prompted.

7. The energy storage device according to claim 1, characterized in that, The power battery cluster and the energy storage battery cluster satisfy one or more of the following conditions: The electrochemical systems are the same; Same cycle life.

8. A power control method, characterized in that, Applied to energy storage devices, the energy storage devices include: An energy storage unit, comprising an energy storage battery cluster and a first PCS, wherein the DC side of the first PCS is electrically connected to the energy storage battery cluster for bidirectional energy transfer between the energy storage battery cluster and an external device; The power unit includes a power battery cluster and a second PCS. The DC side of the second PCS is electrically connected to the power battery cluster and is used for bidirectional energy transfer between the power battery cluster and external devices. The peak charge / discharge rate of the power battery cluster is greater than the rated charge / discharge rate of the energy storage battery cluster. The power controller is communicatively connected to the first PCS and the second PCS, respectively; and The power control method is executed by the power controller, and the method includes: The first state parameter corresponding to the energy storage battery cluster is obtained through the first PCS, and the first state parameter includes the first power corresponding to the current energy storage battery cluster. The second state parameter corresponding to the power battery cluster is obtained through the second PCS, and the second state parameter includes the second power currently corresponding to the power battery cluster. Based on external power demand, the first state parameter, and the second state parameter, independent power control commands are generated and issued to the first PCS and the second PCS to control the power output or input of the energy storage battery cluster and the power battery cluster. This includes: determining the total power of the energy storage device based on the first power and the second power; controlling the power battery cluster to support the external power demand if the total power does not meet the balance requirement; controlling the energy storage battery cluster to support the external power demand if the power battery cluster is insufficient to support it; and, during the process of the power battery cluster supporting the external power demand, if the total power meets the balance requirement, determining the rate of decrease of the power supported by the power battery cluster; determining the power reduction of the power battery cluster in the next cycle based on the rate of decrease; determining the safe power variation range of the energy storage battery cluster; controlling the power battery cluster to reduce the supported power according to the reduced power gradient; and controlling the energy storage battery cluster to support the reduced power of the power battery cluster within the safe power variation range.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it performs the method as described in claim 8.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by the processor, the method of claim 8 is performed.

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