Active overload protection method, device, equipment and medium for network construction type energy storage system

Abstract

The invention discloses an active overload protection method and device for a network-forming energy storage system, equipment and a medium, and relates to the technical field of active overload protection of energy storage systems. The active overload protection method is applied to the BMS, and comprises the following steps: monitoring the output power of the BMS in real time, and determining whether the network energy storage system is in overload operation or not according to the real-time output power of the BMS. And determining the real-time maximum allowable power according to the real-time output power of the BMS in response to overload operation of the networking type energy storage system. And sending the real-time maximum allowable power to the PCS in real time, and controlling the output power of the PCS by the PCS according to the real-time maximum allowable power. Wherein the real-time maximum allowable power is the current maximum allowable power of the networking type energy storage system. According to the invention, the problem of power abuse generated when the network-forming energy storage system is overloaded at different power sections can be avoided, and meanwhile, the complexity of integration of an alternating-current and direct-current side software system is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of active overload protection of energy storage systems, and in particular to a method for active overload protection of a grid-type energy storage system, a device for active overload protection of a grid-type energy storage system, a computer device, and a readable storage medium. Background Art

[0002] Currently, energy storage systems are basically charged and discharged at a power of 0.5P or 0.25P. The overcurrent protection strategy on the DC side is a maximum fixed threshold, which only considers protection actions after exceeding 0.5P or 0.25P. However, there is no corresponding overcurrent protection strategy to address overcurrent problems after power reduction and overcurrent problems during low-temperature and low-power operation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the protection strategy for active overload of the grid-type energy storage system in the prior art has the problems of overcurrent after power reduction and overcurrent during low-temperature and low-power operation.

[0004] In view of the above-mentioned deficiencies in the existing technology, the following solutions are provided:

[0005] In a first aspect, the present invention provides a method for protecting active power overload of a grid-type energy storage system, wherein the grid-type energy storage system includes a BMS and a PCS. The method for protecting active power overload of a grid-type energy storage system is applied to the BMS, and the method includes: monitoring the output power of the BMS in real time, and determining whether the grid-type energy storage system is operating in overload according to the real-time output power of the BMS. In response to the grid-type energy storage system being overloaded, determining the real-time maximum allowable power according to the real-time output power of the BMS. And, sending the real-time maximum allowable power to the PCS in real time, and the PCS controlling the output power of the PCS according to the real-time maximum allowable power. The real-time maximum allowable power is the current maximum allowable power of the grid-type energy storage system.

[0006] Optionally, determining whether the grid-type energy storage system is operating in overload based on the real-time output power of the BMS includes: comparing the real-time output power of the BMS with a first preset power; and in response to the real-time output power of the BMS being greater than the first preset power, determining that the grid-type energy storage system is operating in overload. The first preset power is related to the rated power of the grid-type energy storage system.

[0007] Optionally, in response to the grid-type energy storage system being overloaded, the real-time maximum allowable power is determined based on the real-time output power of the BMS, including: obtaining at least one overload condition, the upper power limit, the lower power limit, and the maximum overload period of each overload condition in at least one overload condition. A first overload condition is determined based on the real-time output power of the BMS, and the upper power limit and the lower power limit of each overload condition in at least one overload condition, and the total duration of the grid-type energy storage system in the first overload condition is determined. Furthermore, the real-time maximum allowable power is determined based on the upper power limit of the first overload condition, the lower power limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the first overload condition, and the real-time output power of the BMS. The first overload condition is the overload condition that the grid-type energy storage system is currently in among at least one overload condition.

[0008] Optionally, determining the first overload condition based on the real-time output power of the BMS and the power upper limit and power lower limit of each overload condition in at least one overload condition includes: comparing the real-time output power of the BMS with the power upper limit of each overload condition in at least one overload condition and the power lower limit of each overload condition in at least one overload condition, and determining the first overload condition based on the comparison result.

[0009] Optionally, determining the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the grid-type energy storage system in the first overload condition, and the real-time output power of the BMS includes: preliminarily setting the real-time maximum allowable power as the power upper limit of the first overload condition; integrating the real-time output power of the BMS based on the total duration of the grid-type energy storage system in the first overload condition to obtain the real-time power integral of the BMS; determining whether reverse current exists; and, in response to the absence of reverse current, determining whether a first preset condition is satisfied. Furthermore, in response to the failure of the first preset condition, determining whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS; and, if it is determined that the preliminarily set real-time maximum allowable power is to be adjusted, adjusting the real-time maximum allowable power to the power lower limit of the first overload condition. The first preset condition includes the maximum value of the charging voltage being greater than or equal to a first preset voltage value, the minimum value of the discharging voltage being less than or equal to a second preset voltage value, or the BMS reporting an overvoltage or undervoltage fault.

[0010] Optionally, determining whether to adjust the pre-set real-time maximum allowable power based on the real-time power integral of the BMS includes: determining a magnitude relationship between the real-time power integral of the BMS and a power integral threshold under a first overload condition. Furthermore, in response to the real-time power integral of the BMS being greater than or equal to the power integral threshold under the first overload condition, determining to adjust the pre-set real-time maximum allowable power. The power integral threshold under the first overload condition is related to the power upper limit of the first overload condition and the maximum overload period of the first overload condition.

[0011] Optionally, determining whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS also includes: in response to the real-time power integral of the BMS being less than the power integral threshold under the first overload condition, maintaining the preliminarily set real-time maximum allowable power as the power upper limit of the first overload condition.

[0012] Optionally, determining the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total time the BMS is in the first overload condition and the real-time output power of the BMS also includes: in response to meeting the first preset condition, adjusting the real-time maximum allowable power to the power lower limit of the first overload condition, and reducing the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition.

[0013] Optionally, determining the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the BMS in the first overload condition, and the real-time output power of the BMS further includes: in response to the presence of reverse current, or in response to the BMS reducing the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition, clearing the real-time power integral of the BMS. Furthermore, re-determining whether the grid-type energy storage system is operating in overload based on the real-time output power of the BMS, and if it is determined that the grid-type energy storage system is operating in overload, re-determining the real-time maximum allowable power based on the real-time output power of the BMS, and sending the re-determined real-time maximum allowable power to the PCS in real time, so that the PCS controls the output power of the PCS based on the re-determined real-time maximum allowable power.

[0014] Optionally, the active overload protection method of the grid-type energy storage system also includes: real-time monitoring of the current of the grid-type energy storage system. Determine whether the grid-type energy storage system is in a fault condition based on the real-time current of the grid-type energy storage system, the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system. And, in response to the grid-type energy storage system being in a fault condition, determine the fault level and corresponding fault response measures based on preset fault conditions, and implement corresponding fault response measures. The preset fault conditions include the relationship between the real-time current of the grid-type energy storage system, the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system under each fault level in at least one fault level, and the fault response measures for each fault level in at least one fault level.

[0015] Optionally, in response to the grid-type energy storage system being in a fault condition, determining the fault level and corresponding fault response measures according to a preset fault condition, including: in response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches the first preset period, it is determined that the grid-type energy storage system is in the first fault level. The fault response measures for the first fault level include cutting off the high-voltage circuit. Where, I is the real-time current of the grid-type energy storage system, P max is the real-time maximum allowable power, V is the real-time voltage of the grid-type energy storage system, x is the first overcurrent level coefficient, and ΔI is the current error redundancy value of the grid-type energy storage system. In response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches the first preset period, it is determined that the grid-type energy storage system is in the second fault level. The fault response measures for the second fault level include limiting the output power of the BMS. Where y is the second overcurrent level coefficient, and x>y. And, in response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, the grid-connected energy storage system is determined to be in the third fault level. The third fault level fault response measures include outputting an alarm prompt message. Where z is the third overcurrent level coefficient, and y>z.

[0016] In a second aspect, the present invention provides an active overload protection device for a grid-type energy storage system, wherein the grid-type energy storage system includes a BMS and a PCS. The active overload protection device for the grid-type energy storage system is applied to the BMS, and the device includes a real-time power monitoring module, a real-time maximum allowable power determination module, and a real-time maximum allowable power sending module. The real-time power monitoring module is configured to monitor the output power of the BMS in real time, and determine whether the grid-type energy storage system is overloaded according to the real-time output power of the BMS. The real-time maximum allowable power determination module is configured to determine the real-time maximum allowable power according to the real-time output power of the BMS in response to the grid-type energy storage system being overloaded. The real-time maximum allowable power is the current maximum allowable power of the grid-type energy storage system. The real-time maximum allowable power sending module is configured to send the real-time maximum allowable power to the PCS in real time, and the PCS controls the output power of the PCS according to the real-time maximum allowable power.

[0017] In a third aspect, the present invention provides a computer device comprising a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes the above-mentioned active overload protection method for the grid-type energy storage system.

[0018] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the processor executes the above-mentioned active overload protection method for the grid-type energy storage system.

[0019] The present invention provides a method, device, equipment, and medium for active overload protection of a grid-type energy storage system. The method determines the DC side system status through the BMS, obtains the real-time maximum allowable power under different overload conditions, and sends the real-time maximum allowable power under different overload conditions to the AC side PCS, so that the PCS can output power according to the actual overload requirements, avoiding the DC side shutdown caused by high-power and low-power overloads, resulting in poor continuous availability of the grid-type energy storage system. At the same time, it provides a judgment basis for DC side overcurrent or overpower protection under different overload conditions, avoids power abuse problems caused by overloads in different power ranges of the energy storage system, and reduces the complexity of AC and DC side software system integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of a grid-type energy storage system in an embodiment of the present invention;

[0021] Figure 2 Flowchart of a method for active overload protection of a grid-type energy storage system according to an embodiment of the present invention;

[0022] Figure 3 Flowchart of another active overload protection method for a grid-type energy storage system according to an embodiment of the present invention;

[0023] Figure 4 Flowchart of another active overload protection method for a grid-type energy storage system according to an embodiment of the present invention;

[0024] Figure 5 Flowchart of another active overload protection method for a grid-type energy storage system according to an embodiment of the present invention;

[0025] Figure 6 Flowchart of another active overload protection method for a grid-type energy storage system according to an embodiment of the present invention;

[0026] Figure 7 A flow chart of another method for protecting active overload of a grid-type energy storage system in an embodiment of the present invention;

[0027] Figure 8 A flow chart of another method for protecting active overload of a grid-type energy storage system in an embodiment of the present invention;

[0028] Figure 9 A flow chart of another method for active overload protection of a grid-type energy storage system in an embodiment of the present invention;

[0029] Figure 10 A flow chart of another method for protecting active overload of a grid-type energy storage system in an embodiment of the present invention;

[0030] Figure 11 This is a flow chart of the DC side of a method for active overload protection of a grid-type energy storage system in an example of an embodiment of the present invention;

[0031] Figure 12 This is a flow chart of the AC side of a method for active overload protection of a grid-type energy storage system in an example of an embodiment of the present invention;

[0032] Figure 13 This is a structural diagram of an active overload protection device for a grid-type energy storage system in an embodiment of the present invention;

[0033] Figure 14 This is a structural diagram of another active overload protection device for a grid-type energy storage system in an embodiment of the present invention;

[0034] Figure 15 This is a structural diagram of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0036] It should be understood that the specific embodiments and drawings described herein are only used to explain the present invention rather than to limit the present invention.

[0037] It is understood that, in the absence of conflict, the various embodiments of the present invention and the various features in the embodiments may be combined with each other.

[0038] It can be understood that, for the convenience of description, the drawings of the present invention only show parts related to the present invention, while parts unrelated to the present invention are not shown in the drawings.

[0039] It can be understood that each unit and module involved in the embodiments of the present invention may correspond to only one physical structure, or may be composed of multiple physical structures, or multiple units and modules may be integrated into one physical structure.

[0040] It will be understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of the present invention may occur in an order different from that marked in the drawings.

[0041] It is understood that the flowcharts and block diagrams of the present invention illustrate the possible architectures, functions, and operations of the systems, devices, equipment, and methods according to various embodiments of the present invention. Each box in the flowchart or block diagram may represent a unit, module, program segment, or code, which contains executable instructions for implementing the specified functions. Moreover, each box or combination of boxes in the block diagram and flowchart may be implemented using a hardware-based system that implements the specified functions, or may be implemented using a combination of hardware and computer instructions.

[0042] It can be understood that the units and modules involved in the embodiments of the present invention can be implemented by software or hardware. For example, the units and modules can be located in a processor.

[0043] Some embodiments of the present invention provide a method for protecting active power overload of a grid-type energy storage system. The grid-type energy storage system includes a battery management system (BMS) and a power conversion system (PCS).

[0044] For example, Figure 1 As shown in the figure, the grid-type energy storage system includes a PCS execution module on the AC side and an energy storage cluster on the DC side. The PCS execution module includes an AC / DC converter unit and a PCS control unit. The energy storage cluster on the DC side includes a Pack group (which integrates multiple battery cells with components such as protection circuit boards to form a ready-to-use finished battery) and a BMS. The BMS includes a main battery control unit (Battery Control Unit, BCU).

[0045] Some embodiments of the present invention provide a method for protecting active overload of a grid-type energy storage system applied to a BMS, such as Figure 2As shown, the method includes steps 201 to 203.

[0046] Step 201: Monitor the output power of the BMS in real time, and determine whether the grid-type energy storage system is overloaded based on the real-time output power of the BMS.

[0047] In some embodiments, the method for implementing step 201 includes comparing the real-time output power of the BMS with a first preset power, and determining that the grid-type energy storage system is overloaded in response to the real-time output power of the BMS being greater than the first preset power. The first preset power is related to the rated power of the grid-type energy storage system.

[0048] For example, the first preset power can be equal to the rated power of the grid-type energy storage system. As the batteries in the energy storage cluster age, and to account for factors such as battery aging, the first preset power can be set to a value less than the rated power of the grid-type energy storage system. In this way, if the actual output power of the BMS exceeds the first preset power, the BMS can be considered to be overloaded.

[0049] Step 202: In response to the grid-type energy storage system being overloaded, determine the real-time maximum allowable power according to the real-time output power of the BMS.

[0050] In step 202 , the real-time maximum allowable power is the current maximum allowable power of the grid-connected energy storage system.

[0051] It is understandable that when the real-time output power of the BMS is different, the corresponding real-time maximum allowable power and allowable overload time are also different.

[0052] For example, in some cases, according to industry standards, grid-connected energy storage systems require AC-side current overload capacity. In the event of active power overload, the DC-side hardware should have overload capacity of 1.1 times the rated power for a long period, 1.2 times the rated power for 2 minutes, 1.5 times the rated power for 1 minute, and 3 times the rated power for 10 seconds. During energy storage system operation, the DC-side software layer (BMS) sends the PCS the maximum allowable charge and discharge power of 1.1Pn for 10 minutes, 1.2Pn for 2 minutes, 1.5Pn for 1 minute, and 3Pn for 10 seconds, where Pn is the system rated power.

[0053] In some embodiments, as Figure 3 As shown, the implementation method of step 202 includes steps 301 to 303.

[0054] Step 301: Obtain at least one overload operating condition, and the upper power limit, lower power limit, and maximum overload period of each overload operating condition in the at least one overload operating condition.

[0055] It can be understood that at least one overload operating condition, the power upper limit of each overload operating condition in at least one overload operating condition, and the power lower limit of each overload operating condition in at least one overload operating condition can be manually pre-set, or the relevant settings of the industry standard can be used to determine at least one overload operating condition, the power upper limit of each overload operating condition in at least one overload operating condition, and the power lower limit of each overload operating condition in at least one overload operating condition.

[0056] For example, taking an example where at least one artificially preset overload operating condition includes three overload operating conditions, the upper power limit of each of the three overload operating conditions and the lower power limit of each of the three overload operating conditions are shown in Table 1.

[0057] Table 1 Name and power setting of each overload condition in the three overload conditions

[0058]

[0059]

[0060] As shown in Table 1, in overload condition 1, the power upper limit is k2×P p , the lower power limit is k1×P p , in overload condition 2, the power upper limit is k2×P p , the lower power limit is k1×P p , in overload condition 3, the power upper limit is k4×P p , the lower power limit is k3×P p +P1. Among them, P p is the first preset power, k1, k2, k3, and k4 are overload coefficients, and 1≤k1<k2<k3<k4, P1≥0, P1 is used to distinguish the power upper limit of overload condition 1 from the power lower limit of overload condition 2, and to distinguish the power upper limit of overload condition 2 from the power lower limit of overload condition 3. For example, the overload coefficients can be k1=1.1, k2=1.2, k3=1.5, and k4=3, respectively.

[0061] Step 302: Determine a first overload condition according to the real-time output power of the BMS and the upper power limit and the lower power limit of each overload condition in at least one overload condition.

[0062] In step 302 , the first overload operating condition is an overload operating condition in which the grid-connected energy storage system is currently located among at least one overload operating condition.

[0063] In some embodiments, as Figure 4 As shown, the implementation method of step 302 includes steps 401 to 401.

[0064] Step 401: Compare the real-time output power of the BMS with the power upper limit of each overload condition in at least one overload condition and the power lower limit of each overload condition in at least one overload condition, and determine a first overload condition based on the comparison results.

[0065] It is understandable that obtaining the data in Table 1 facilitates comparison of the real-time output power of the BMS with the upper and lower power limits of at least one overload condition, thereby determining the real-time maximum allowable power.

[0066] It can be understood that if the actual output power of the BMS is within the power range [k1×P p , k2×P p ] or in the power range (k1×P p , k2×P p ] (for example, k1=1), the first overload condition of the BMS can be considered as overload condition 1. If the actual output power of the BMS is within the power interval [k2×P p +P1,k3×P p ] or in the power range (k2×P p , k3×P p ] (for example, P1=0), the first overload condition of the BMS can be considered as overload condition 2. If the actual output power of the BMS is within the power interval [k3×P p +P1,k4×P p ] or within the power range (k3×P p , k4×P p ] (for example, P1=0), the first overload condition of the BMS can be considered as overload condition 3.

[0067] Step 303: Determine the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the duration of the grid-connected energy storage system in the first overload condition, and the real-time output power of the BMS.

[0068] It is understandable that the real-time maximum allowable power when the BMS first enters the overload condition may be different from the real-time maximum allowable overload power after the BMS has been in the first overload condition for a period of time. Therefore, the real-time maximum allowable power needs to be determined according to step 303.

[0069] In some embodiments, as Figure 5 As shown, the implementation method of step 303 includes steps 501 to 505.

[0070] Step 501: Preliminarily set the real-time maximum allowable power as the power upper limit of the first overload condition.

[0071] It is understandable that when the BMS just starts to enter a certain overload condition, it can determine that the real-time maximum allowable power is the power upper limit of the first overload condition.

[0072] Step 502: Integrate the real-time output power of the BMS according to the total duration of the grid-type energy storage system being in the first overload condition to obtain the real-time power integral of the BMS.

[0073] Understandably, since the real-time maximum allowable power may be adjusted, the grid-type energy storage system may be in the first overload condition multiple times during a given operation of the grid-type energy storage system. The total duration of the grid-type energy storage system in the first overload condition in step 502 refers to the duration from the time the grid-type energy storage system entered the first overload condition to the current time. The real-time power integration of the BMS takes into account the duration of the grid-type energy storage system's active power overload operation.

[0074] Step 503: Determine whether there is a reverse current.

[0075] Understandably, if the current direction changes, the batteries in the energy storage cluster may switch between charging and discharging states, and the grid-type energy storage system may no longer be overloaded. If the current direction does not change, the grid-type energy storage system may still be overloaded.

[0076] Step 504: In response to the absence of reverse current, determine whether a first preset condition is met.

[0077] In step 504 , the first preset condition includes that the maximum value of the charging voltage is greater than or equal to the first preset voltage value, or the minimum value of the discharging voltage is less than or equal to the second preset voltage value, or the BMS reports an over-voltage or under-voltage fault.

[0078] It can be understood that the first preset voltage value and the second preset voltage value can be calibrated and confirmed by testing the overload power of the battery cell. Taking into account the objective reason that there is a voltage difference between the battery cell in the high or low power state and the battery cell, when overload charging and discharging is performed with a momentary high power, the battery cell charge and discharge voltage will quickly approach the battery cell charge and discharge cut-off voltage, causing the BMS to report the most serious over-voltage or under-voltage fault of the battery cell, cutting off the high-voltage circuit and causing the system to shut down, resulting in the energy storage system being unable to be fully discharged and unable to work continuously. At this time, it is necessary to reduce the power overload according to the highest single cell voltage state of the battery cell (such as the first preset voltage value) or the lowest single cell voltage state of the battery cell (such as the second preset voltage value) during the charging and discharging process when overloaded, to avoid over-voltage or under-voltage on the DC side causing shutdown. Therefore, if the first preset condition is met, it means that the operation of the grid-type energy storage system has almost reached a critical situation, and measures need to be taken immediately to avoid the situation where the grid-type energy storage system shuts down. If the first preset condition is not met, the real-time power integration of the BMS can be used to determine when to take measures.

[0079] Step 505: In response to the first preset condition not being met, determining whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS, and if it is determined that the preliminarily set real-time maximum allowable power is to be adjusted, adjusting the real-time maximum allowable power to the power lower limit of the first overload condition.

[0080] In some embodiments, as Figure 6 As shown, the method for determining whether to adjust the preliminarily determined real-time maximum allowable power according to the real-time power integration of the BMS in step 505 includes steps 601 and 602.

[0081] Step 601: Determine the relationship between the real-time power integral of the BMS and the power integral threshold under a first overload condition.

[0082] In step 601, the power integration threshold under the first overload condition is related to the power upper limit of the first overload condition and the maximum overload period of the first overload condition.

[0083] It can be understood that when the real-time power integral of the BMS is greater than or equal to the power integral threshold of the grid-type energy storage system, continuing the current overload condition may cause damage to the grid-type energy storage system. Therefore, it is necessary to first determine the size relationship between the real-time power integral of the BMS and the power integral threshold under the first overload condition.

[0084] Step 602: In response to the real-time power integral of the BMS being greater than or equal to a power integral threshold under a first overload condition, determining to adjust the preliminarily set real-time maximum allowable power.

[0085] It is understandable that the real-time power integral of the BMS continues to increase over time. Therefore, when the real-time power integral of the BMS is equal to the power integral threshold under the first overload condition, it is necessary to adjust the preliminarily determined real-time maximum allowable power. According to step 505, the real-time maximum allowable power is adjusted to the power lower limit of the first overload condition, so that the grid-type energy storage system no longer continues to operate under the current overload condition.

[0086] For example, as shown in Table 1, when the first overload condition is overload condition 3, if Then the real-time maximum allowable power needs to be changed from k4×P p Adjust to k3×P p +P1, where is the real-time power integral of the BMS, t1 is the starting time when the BMS enters overload condition 3, t2 is the current time point (when the current time point t2 and the total time length of the grid-type energy storage system in the first overload condition are known, the starting time t1 when the BMS enters overload condition 3 can be calculated). The variable in the integral is time, in seconds, P c is the real-time output power of BMS, is the power integration threshold of overload condition 3, T3 is the maximum overload period of overload condition 3 (for example, in the relevant standards, k4 is 3 and T3 is 10 seconds), and ΔP is the redundant power value after considering the PCS power control deviation and the voltage and current sampling accuracy of the energy storage system.

[0087] For example, as shown in Table 1, when the first overload condition is overload condition 2, if Then the real-time maximum allowable power needs to be changed from k3×P p Adjust to k2×P p +P1. Among them, is the power integration threshold of overload condition 2, and T2 is the maximum overload period of overload condition 3 (for example, in relevant standards, k3 is 1.5 and T2 is 60 seconds).

[0088] For example, as shown in Table 1, when the first overload condition is overload condition 1, if Then the real-time maximum allowable power needs to be changed from k2×P p Adjust to k1×P p .in, is the power integration threshold of overload condition 1, and T1 is the maximum overload period of overload condition 1 (for example, in relevant standards, k2 is 1.5 and T1 is 120 seconds).

[0089] In some embodiments, as Figure 7As shown, the method for determining whether to adjust the preliminarily determined real-time maximum allowable power according to the real-time power integration of the BMS in step 505 further includes step 701.

[0090] Step 701: In response to the real-time power integral of the BMS being less than the power integral threshold under the first overload condition, the preliminarily set real-time maximum allowable power is maintained as the power upper limit of the first overload condition.

[0091] It can be understood that when the real-time power integral of the BMS is less than the power integral threshold under the first overload condition, the overload capacity of the grid-type energy storage system can support the grid-type energy storage system to continue operating under the current overload condition, so the preliminarily determined real-time maximum allowable power can be maintained as the power upper limit of the first overload condition.

[0092] In some embodiments, as Figure 8 As shown, the implementation method of step 402 also includes step 801.

[0093] Step 801: In response to a first preset condition being met, the real-time maximum allowable power is adjusted to the power lower limit of the first overload condition, and the real-time output power of the BMS is reduced to a level less than or equal to the power lower limit of the first overload condition.

[0094] It can be understood that the satisfaction of the first preset condition indicates that the operation of the grid-type energy storage system has almost reached a critical situation. At this time, immediate measures need to be taken to avoid damage to the grid-type energy storage system. That is, the BMS can adjust the real-time maximum allowable power to the power lower limit of the first overload condition and reduce the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition.

[0095] In some embodiments, as Figure 9 As shown, the implementation method of step 302 also includes steps 901 and 902.

[0096] Step 901: In response to the presence of reverse current, or in response to the BMS reducing the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition, the real-time power integral of the BMS is cleared.

[0097] It is understandable that if there is a reverse current, it means that the current direction has changed, then the batteries in the energy storage cluster may be switching between charging and discharging states. At this time, the grid-type energy storage system may not be overloaded and no further judgment will be made. Therefore, the real-time power integral of the BMS can be cleared.

[0098] It can be understood that when the BMS reduces the real-time output power of the BMS to a level less than or equal to the power lower limit of the first overload condition, the first overload condition is likely to have changed. At this time, the real-time maximum allowable power has changed, and the real-time power integral of the BMS needs to be recalculated. Therefore, the real-time power integral of the BMS can be cleared.

[0099] Step 902: Re-determine whether the grid-type energy storage system is operating in overload mode based on the real-time output power of the BMS. If the grid-type energy storage system is determined to be operating in overload mode, re-determine the real-time maximum allowable power based on the real-time output power of the BMS, and send the re-determined real-time maximum allowable power to the PCS in real time. The PCS controls the output power of the PCS based on the re-determined real-time maximum allowable power.

[0100] It can be understood that after the real-time power integral of the BMS is cleared, steps 201 to 203 can be re-executed.

[0101] Step 203: Send the real-time maximum allowed power to the PCS in real time, and the PCS controls the output power of the PCS according to the real-time maximum allowed power.

[0102] It can be understood that during operation, the PCS will obtain its own real-time maximum allowable power according to its own operating capacity in real time. After receiving the real-time maximum allowable power sent by the BMS, the PCS can take the smaller of the real-time maximum allowable power of the PCS itself and the real-time maximum allowable power sent by the BMS to obtain the maximum allowable power after taking the smaller value, and then control the output power of the PCS to be less than the maximum allowable power after taking the smaller value.

[0103] In some embodiments, as Figure 10 As shown, some embodiments of the present invention provide a method for protecting active overload of a grid-type energy storage system further including steps 1001 to 1003 .

[0104] Step 1001: monitor the current of the grid-connected energy storage system in real time.

[0105] Step 1002: Determine whether the grid-type energy storage system is in a fault condition based on the real-time current, the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system.

[0106] It can be understood that whether the real-time current of the grid-type energy storage system is normal can be determined based on the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system. If it is normal, the grid-type energy storage system is not in a fault condition; if it is abnormal, the grid-type energy storage system is in a fault condition.

[0107] Step 1003: In response to the grid-connected energy storage system being in a faulty operating condition, a fault level and corresponding fault response measures are determined according to a preset fault condition, and the corresponding fault response measures are implemented.

[0108] In step 1003, the preset fault conditions include the real-time current of the grid-connected energy storage system at each fault level in at least one fault level, the relationship between the real-time maximum allowable power and the real-time voltage of the grid-connected energy storage system, and the fault response measures for each fault level in at least one fault level.

[0109] In some embodiments, the implementation method of step 1003 includes: responding to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches the first preset period, it is determined that the grid-type energy storage system is at the first fault level. The corresponding measures for the first fault level include cutting off the high-voltage circuit. Where, I is the real-time current of the grid-type energy storage system, P max is the real-time maximum allowable power, V is the real-time voltage of the grid-type energy storage system, x is the first overcurrent level coefficient, and ΔI is the current error redundancy value of the grid-type energy storage system.

[0110] In some embodiments, the implementation method of step 1003 includes: responding to the real-time current of the grid-type energy storage system satisfying the formula If the fault persists for a first predetermined period of time, the grid-connected energy storage system is determined to be at the second fault level. Measures corresponding to the second fault level include limiting the output power of the BMS. Where y is the second overcurrent level coefficient, and x>y.

[0111] In some embodiments, the implementation method of step 1003 includes: responding to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, the grid-connected energy storage system is determined to be at the third fault level. The corresponding measures for the third fault level include outputting an alarm prompt message. Where z is the third overcurrent level coefficient, and y>z.

[0112] It can be understood that x>y>z, then in P max and V remain unchanged, and These three current values ​​decrease in sequence, which can result in different levels of faults.

[0113] ΔI is the current error redundancy value of the grid-type energy storage system, which can avoid the overcurrent misdiagnosis caused by the error of the sampling current when the system power is 0. and The maximum of these three current values ​​and ΔI is then used to determine the difference between the real-time current of the grid-type energy storage system and the maximum value, ultimately determining the fault level. The current error margin value ΔI for the grid-type energy storage system is understood to be related to the system current sampling error and the actual current in the high-voltage circuit when the system's maximum allowable power is zero. This current value must be determined based on actual application conditions.

[0114] The following uses an example to illustrate an active overload protection method for a grid-type energy storage system provided by an embodiment of the present invention.

[0115] This example proposes a method for active overload protection of a grid-type energy storage system. Figure 11 and Figure 12 As shown in the figure, the active power overload protection method of the grid-type energy storage system is as follows:

[0116] In this example, the BMS determines the DC side system status, estimates the power limits for different DC side overload conditions, and sends these limits to the AC side PCS. This ensures that the PCS outputs power according to the actual overload requirements, preventing DC side shutdowns caused by high or low battery overloads, which could result in poor system availability. This also provides a basis for determining DC side overcurrent or overpower protection under different overload conditions.

[0117] Grid-type energy storage systems require the AC side current to have overload capacity. When the active power is overloaded, the DC side hardware should have an overload capacity of 1.1 times the rated power for a long period of time (corresponding to a 1.1 times overload condition), 1.2 times the rated power for 2 minutes (corresponding to a 1.2 times overload condition), 1.5 times the rated power for 1 minute (corresponding to a 1.5 times overload condition), and 3 times the rated power for 10 seconds (corresponding to a 3 times overload condition). During the operation of the grid-type energy storage system, the DC-side software layer BMS sends the PCS the maximum charge and discharge allowable power of 1.1Pn for 10 minutes, 1.2Pn for 2 minutes, 1.5Pn for 1 minute, and 3Pn for 10 seconds, where Pn is the rated power of the grid-type energy storage system. When the AC side is overloaded with active power, the PCS outputs according to the corresponding overload power and time limit.

[0118] 2) Considering the objective reasons for the voltage difference between cells in high or low charge states and between cells, when overloaded charging and discharging is performed at a momentary high power, the cell charge and discharge voltage will quickly approach the cell charge and discharge cutoff voltage, causing the BMS to report the most serious cell overvoltage or undervoltage fault, cutting off the high-voltage circuit and causing the grid-type energy storage system to shut down. This will cause the grid-type energy storage system to be unable to fully charge or discharge and unable to operate continuously. Therefore, the AC-side PCS or DC-side BMS should reduce the power overload according to the highest cell voltage or the lowest cell voltage during the overloaded charging and discharging process to avoid shutdown caused by overvoltage or undervoltage on the DC side.

[0119] 3) Considering that the maximum allowable power output of the battery cell will be affected by different temperature ranges, the DC side BMS limits the maximum allowable overload power on the DC side by comprehensively considering the battery cell temperature and battery cell voltage, thereby avoiding discontinuity in the user's use of the grid-type energy storage system.

[0120] At the same time, because the battery state of charge (also called remaining capacity, State of Charge, SOC) is an estimated quantity and has a large error relative to the voltage, the BMS should not use SOC as a condition for overload power limiting.

[0121] The active overload protection scheme for grid-connected energy storage systems adheres to three principles: ensuring cell safety, preserving cell life, and maximizing cell capacity. The details are as follows:

[0122] AC side: When the grid-connected energy storage system is overloaded, the PCS outputs different overload powers according to the overload demand sent by the DC side. During overload, the overload power cannot exceed the maximum allowable power in the power map sent by the BMS.

[0123] DC side:

[0124] a. The power map output by the BMS includes four power maps: 1.1Pn - long-term power map, 1.2Pn - 2-minute power map, 1.5Pn - 1-minute power map, and 3Pn - 10-second power map, where Pn is the rated power.

[0125] b. When the grid-type energy storage system is overloaded, the BMS outputs the maximum allowable power in the above four maps based on the battery cell voltage and battery cell temperature;

[0126] c. When the active power of the grid-type energy storage system is overloaded, the power is increased and the BMS outputs power according to the power map. When the power is reduced and the BMS outputs four MAP powers according to the power integration, the following are the results:

[0127] (1) When 1.5Pn<P≤3Pn, if The real-time maximum allowable power needs to be adjusted from 3Pn to 1.5Pn, where t1 is the starting time when the grid-type energy storage system enters the current overload condition (i.e., the first overload condition, which is a 3x overload condition), and t2 is the current time point. If the current reverses or P < 1.5Pn for the second preset period, it means that the grid-type energy storage system may have completed the switching between charging and discharging, or has entered another overload condition (e.g., a 1.5x overload condition). At this time, the maximum allowable power under the 3x overload condition is the Map power, i.e., 3Pn.

[0128] (2) When 1.2Pn<P≤1.5Pn, if The real-time maximum allowable power needs to be adjusted from 1.5Pn to 1.2Pn. If the current reverses or P < 1.2Pn for the second preset period, it means that the grid-type energy storage system may have completed the switching between charging and discharging, or has entered another overload condition (for example, 1.2 times overload condition). At this time, the real-time maximum allowable power under the 1.5 times overload condition is Map power, that is, 1.5Pn.

[0129] (3) When 1.1Pn<P≤1.2Pn, if The real-time maximum allowable power needs to be adjusted from 1.2Pn to 1.1Pn. If the current reverses or P<1.1Pn for the second preset period, it means that the grid-type energy storage system may have completed the switching between charging and discharging, or has entered another overload condition (for example, 1.1 times overload condition). At this time, the real-time maximum allowable power under the 1.2 times overload condition is Map power, that is, 1.2Pn.

[0130] Wherein, ΔP is the redundant power value after considering the PCS power control deviation and the voltage and current sampling accuracy of the grid-type energy storage system.

[0131] d. When a grid-type energy storage system is overcharged and the BMS detects a maximum cell voltage of Vmax ≥ m, or when it is overcharged and the BMS detects a minimum cell voltage of Vmin ≤ n, the 3Pn, 1.5Pn, 1.2Pn, and 1.1Pn power outputs are reduced. m is the first preset voltage value, and n is the second preset voltage value. Both m and n must be calibrated and confirmed by testing the cell overload power. If the BMS reports a secondary overvoltage or undervoltage fault during an overload, the PCS should immediately stop the overload power output.

[0132] e. BMS overcurrent protection strategy:

[0133] Level 1 fault: And the duration is t1, cutting off the high-voltage circuit;

[0134] Secondary fault: And the duration is t1, limiting the output power;

[0135] Level 3 fault: And the duration is t1, an alarm prompts;

[0136] Where I is the real-time current of the grid-type energy storage system, P max is the real-time maximum allowable power, V is the real-time voltage of the grid-type energy storage system, x, y, and z are different overcurrent level coefficients, and x>y>zΔI is the error redundancy value adopted by the system current.

[0137] Some embodiments of the present invention provide a grid-type energy storage system active overload protection device, the grid-type energy storage system includes a BMS and a PCS, and the grid-type energy storage system active overload protection device is applied to the BMS. Figure 13 As shown, the active overload protection device 1300 of the grid-type energy storage system includes a real-time power monitoring module 1301 , a real-time maximum allowable power determination module 1302 and a real-time maximum allowable power transmission module 1303 .

[0138] The real-time power monitoring module 1301 is configured to monitor the output power of the BMS in real time, and determine whether the grid-type energy storage system is overloaded according to the real-time output power of the BMS.

[0139] In some embodiments, the real-time power monitoring module 1301 is configured to compare the real-time output power of the BMS with a first preset power, and determine that the grid-type energy storage system is overloaded in response to the real-time output power of the BMS being greater than the first preset power. The first preset power is related to the rated power of the grid-type energy storage system.

[0140] The real-time maximum allowable power determination module 1302 is configured to: in response to the grid-type energy storage system being overloaded, determine the real-time maximum allowable power according to the real-time output power of the BMS, wherein the real-time maximum allowable power is the current maximum allowable power of the grid-type energy storage system.

[0141] In some embodiments, the real-time maximum allowable power determination module 1302 is configured to: obtain at least one overload condition, the power upper limit, the power lower limit, and the maximum overload period of each overload condition in at least one overload condition. Determine the first overload condition based on the real-time output power of the BMS, and the power upper limit and the power lower limit of each overload condition in at least one overload condition; and determine the total duration of the grid-type energy storage system in the first overload condition. And, determine the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the first overload condition, and the real-time output power of the BMS. Wherein, the first overload condition is the overload condition that the grid-type energy storage system is currently in among at least one overload condition.

[0142] In some embodiments, when the first overload condition is determined based on the real-time output power of the BMS and the power upper limit and power lower limit of the first overload condition, the real-time maximum allowable power determination module 1302 is configured to: compare the real-time output power of the BMS with the power upper limit of each overload condition in at least one overload condition and the power lower limit of each overload condition in at least one overload condition, and determine the first overload condition based on the comparison result.

[0143] In some embodiments, when determining the real-time maximum allowable power based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the grid-type energy storage system in the first overload condition, and the real-time output power of the BMS, the real-time maximum allowable power determination module 1302 is configured to: preliminarily set the real-time maximum allowable power as the power upper limit of the first overload condition; integrate the real-time output power of the BMS based on the grid-type energy storage system being in the first overload condition to obtain the real-time power integral of the BMS; determine whether reverse current exists; and, in response to the absence of reverse current, determine whether a first preset condition is met. Furthermore, in response to the first preset condition not being met, determine whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS; and, if it is determined that the preliminarily set real-time maximum allowable power is to be adjusted, adjust the real-time maximum allowable power to the power lower limit of the first overload condition. The first preset condition includes the maximum value of the charging voltage being greater than or equal to a first preset voltage value, the minimum value of the discharging voltage being less than or equal to a second preset voltage value, or the BMS reporting an overvoltage or undervoltage fault.

[0144] In some embodiments, when determining whether to adjust the preliminarily determined real-time maximum allowable power based on the real-time power integral of the BMS, the real-time maximum allowable power determination module 1302 is configured to: determine the relationship between the real-time power integral of the BMS and a power integral threshold under a first overload condition. Furthermore, in response to the real-time power integral of the BMS being greater than or equal to the power integral threshold under the first overload condition, determine to adjust the preliminarily set real-time maximum allowable power. The power integral threshold under the first overload condition is related to the power upper limit of the first overload condition and the maximum overload period of the first overload condition.

[0145] In some embodiments, when determining whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS, the real-time maximum allowable power determination module 1302 is configured to: in response to the real-time power integral of the BMS being less than the power integral threshold under the first overload condition, maintain the preliminarily set real-time maximum allowable power as the power upper limit of the first overload condition.

[0146] In some embodiments, when the real-time maximum allowable power is determined based on the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total time the BMS is in the first overload condition and the real-time output power of the BMS, the real-time maximum allowable power determination module 1302 is further configured to: in response to meeting the first preset condition, adjust the real-time maximum allowable power to the power lower limit of the first overload condition, and reduce the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition.

[0147] In some embodiments, when the real-time maximum allowable power is determined based on the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the BMS in the first overload condition, and the real-time output power of the BMS, the real-time maximum allowable power determination module 1302 is further configured to: in response to the presence of reverse current or in response to the BMS reducing the real-time output power of the BMS to less than or equal to the power lower limit of the first overload condition, clear the real-time power integral of the BMS, and re-determine whether the grid-type energy storage system is operating under overload based on the real-time output power of the BMS. If it is determined that the grid-type energy storage system is operating under overload, re-determine the real-time maximum allowable power based on the real-time output power of the BMS, and transmit the re-determined real-time maximum allowable power to the PCS in real time, so that the PCS controls the output power of the PCS based on the re-determined real-time maximum allowable power.

[0148] The real-time maximum allowed power sending module 1303 is configured to send the real-time maximum allowed power to the PCS in real time, and the PCS controls the output power of the PCS according to the real-time maximum allowed power.

[0149] In some embodiments, as Figure 14 As shown, the grid-type energy storage system active overload protection device 1300 further includes a current detection module 1401 , a fault condition determination module 1402 , and a fault level and response measure determination module 1403 .

[0150] The current detection module 1401 is configured to monitor the current of the grid-type energy storage system in real time.

[0151] The fault condition determination module 1402 is configured to determine whether the grid-type energy storage system is in a fault condition according to the real-time current, the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system.

[0152] The fault level and response measure determination module 1403 is configured to, in response to the grid-type energy storage system being in a faulty operating condition, determine the fault level and corresponding fault response measures based on preset fault conditions, and implement the corresponding fault response measures. The preset fault conditions include the relationship between the real-time current, real-time maximum allowable power, and real-time voltage of the grid-type energy storage system for each of at least one fault level, and the fault response measures for each of the at least one fault level.

[0153] In some embodiments, the fault level and response measure determination module 1403 is configured to: respond to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches the first preset period, it is determined that the grid-type energy storage system is in the first fault level. The fault response measures for the first fault level include cutting off the high-voltage circuit. Where, I is the real-time current of the grid-type energy storage system, Pmax is the real-time maximum allowable power, V is the real-time voltage of the grid-type energy storage system, x is the first overcurrent level coefficient, and ΔI is the current error redundancy value of the grid-type energy storage system. In response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches the first preset period, it is determined that the grid-type energy storage system is in the second fault level. The fault response measures for the second fault level include limiting the output power of the BMS. Where y is the second overcurrent level coefficient, and x>y. And, in response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, the grid-connected energy storage system is determined to be in the third fault level. The third fault level fault response measures include outputting an alarm prompt message. Where z is the third overcurrent level coefficient, and y>z.

[0154] The specific scheme and beneficial effects of the active overload protection device 1800 of a grid-type energy storage system provided in some embodiments of the present invention can be referred to the relevant description of the active overload protection method of a grid-type energy storage system provided in some embodiments of the present invention, which will not be repeated here.

[0155] Some embodiments of the present invention provide a computer device, such as Figure 15 As shown, the computer device 1500 includes a memory 1501 and a processor 1502. The memory 1501 stores a computer program. When the processor 1502 runs the computer program stored in the memory 1501, the processor 1502 executes the above-mentioned grid-type energy storage system active overload protection method.

[0156] The specific solutions and beneficial effects of a computer device provided by some embodiments of the present invention can be referred to the relevant description of an active overload protection method for a grid-type energy storage system provided by some embodiments of the present invention, which will not be repeated here.

[0157] Some embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the processor executes the above-mentioned active power overload protection method for a grid-type energy storage system.

[0158] The specific solutions and beneficial effects of a computer-readable storage medium provided in some embodiments of the present invention can be referred to the relevant description of an active overload protection method for a grid-type energy storage system provided in some embodiments of the present invention, which will not be repeated here.

[0159] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for protecting active power overload of a grid-type energy storage system, wherein the grid-type energy storage system includes a battery management system (BMS) and a converter (PCS); characterized in that: The method is applied to the BMS, and the method includes: monitoring the output power of the BMS in real time, and determining whether the grid-type energy storage system is overloaded according to the real-time output power of the BMS; In response to the grid-type energy storage system being overloaded, determining a real-time maximum allowable power according to the real-time output power of the BMS; the real-time maximum allowable power is the current maximum allowable power of the grid-type energy storage system; and The real-time maximum allowed power is sent to the PCS in real time, and the PCS controls the output power of the PCS according to the real-time maximum allowed power.

2. The active power overload protection method for a grid-type energy storage system according to claim 1, characterized in that: The determining whether the grid-type energy storage system is overloaded according to the real-time output power of the BMS includes: The real-time output power of the BMS is compared with a first preset power. In response to the real-time output power of the BMS being greater than the first preset power, it is determined that the grid-type energy storage system is operating in overload; the first preset power is related to the rated power of the grid-type energy storage system.

3. The active power overload protection method for a grid-type energy storage system according to claim 1, characterized in that: In response to the grid-type energy storage system being overloaded, determining the real-time maximum allowable power according to the real-time output power of the BMS includes: Obtaining at least one overload operating condition, an upper power limit, a lower power limit, and a maximum overload period of each overload operating condition in the at least one overload operating condition; determining a first overload condition based on the real-time output power of the BMS and the upper and lower power limits of each overload condition in the at least one overload condition; and determining a total duration for the grid-type energy storage system to be in the first overload condition; the first overload condition being the overload condition in which the grid-type energy storage system is currently in the at least one overload condition; and The real-time maximum allowable power is determined according to the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the first overload condition and the real-time output power of the BMS.

4. The active power overload protection method for a grid-type energy storage system according to claim 3, characterized in that: The determining the first overload operating condition according to the real-time output power of the BMS and the upper power limit and the lower power limit of each overload operating condition in at least one overload operating condition includes: The real-time output power of the BMS is compared with the power upper limit of each overload condition in the at least one overload condition and the power lower limit of each overload condition in the at least one overload condition, and a first overload condition is determined.

5. The active power overload protection method for a grid-type energy storage system according to claim 3, characterized in that: The determining of the real-time maximum allowable power according to the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the grid-type energy storage system being in the first overload condition, and the real-time output power of the BMS includes: Preliminarily setting the real-time maximum allowable power as the power upper limit of the first overload condition; performing an integration operation on the real-time output power of the BMS according to the total duration of the grid-type energy storage system being in the first overload condition to obtain a real-time power integral of the BMS; Determine whether reverse current exists; In response to the absence of reverse current, determining whether a first preset condition is satisfied; the first preset condition includes that the maximum value of the charging voltage is greater than or equal to a first preset voltage value, or the minimum value of the discharging voltage is less than or equal to a second preset voltage value, or the BMS reports an overvoltage or undervoltage fault; and In response to not meeting the first preset condition, determining whether to adjust the preliminarily set real-time maximum allowable power based on the real-time power integral of the BMS, and if it is determined that the preliminarily set real-time maximum allowable power is to be adjusted, adjusting the real-time maximum allowable power to the power lower limit of the first overload condition.

6. The active power overload protection method for a grid-type energy storage system according to claim 5, characterized in that: The determining whether to adjust the preliminarily set real-time maximum allowable power according to the real-time power integral of the BMS includes: Determining a relationship between the real-time power integral of the BMS and a power integral threshold under a first overload condition; wherein the power integral threshold under the first overload condition is related to the power upper limit of the first overload condition and the maximum overload period of the first overload condition; and In response to the real-time power integral of the BMS being greater than or equal to a power integral threshold under the first overload condition, it is determined to adjust the preliminarily set real-time maximum allowable power.

7. The active power overload protection method for a grid-type energy storage system according to claim 6, characterized in that: The determining whether to adjust the preliminarily set real-time maximum allowable power according to the real-time power integral of the BMS further includes: In response to the real-time power integral of the BMS being less than the power integral threshold under the first overload condition, maintaining the initially set real-time maximum allowable power as the power upper limit of the first overload condition.

8. The active power overload protection method for a grid-type energy storage system according to claim 5, characterized in that: The determining of the real-time maximum allowable power according to the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the first overload condition, and the real-time output power of the BMS further includes: In response to satisfying a first preset condition, the real-time maximum allowed power is adjusted to a power lower limit of the first overload condition, and the real-time output power of the BMS is reduced to a level less than or equal to the power lower limit of the first overload condition.

9. The active power overload protection method for a grid-type energy storage system according to claim 8, characterized in that: The determining of the real-time maximum allowable power according to the power upper limit of the first overload condition, the power lower limit of the first overload condition, the maximum overload period of the first overload condition, the total duration of the first overload condition, and the real-time output power of the BMS further includes: In response to the presence of reverse current, or in response to reducing the real-time output power of the BMS to less than or equal to the lower power limit of the first overload condition, clearing the real-time power integral of the BMS; and Re-determine whether the grid-type energy storage system is operating in overload according to the real-time output power of the BMS, and if it is determined that the grid-type energy storage system is operating in overload, re-determine the real-time maximum allowable power according to the real-time output power of the BMS, and send the re-determined real-time maximum allowable power to the PCS in real time, so that the PCS controls the output power of the PCS according to the re-determined real-time maximum allowable power.

10. The active power overload protection method for a grid-type energy storage system according to claim 1, characterized in that: Also includes: Real-time monitoring of the current of the grid-type energy storage system; determining whether the grid-type energy storage system is in a fault condition according to the real-time current of the grid-type energy storage system, the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system; as well as In response to the grid-type energy storage system being in a fault condition, a fault level and corresponding fault response measures are determined according to preset fault conditions, and the corresponding fault response measures are implemented; the preset fault conditions include the real-time current of the grid-type energy storage system at each fault level in at least one fault level, the relationship between the real-time maximum allowable power and the real-time voltage of the grid-type energy storage system, and the fault response measures for each fault level in at least one fault level.

11. The active power overload protection method for a grid-type energy storage system according to claim 10, characterized in that: In response to the grid-type energy storage system being in a fault condition, determining a fault level and corresponding fault response measures according to a preset fault condition includes: In response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, it is determined that the grid-type energy storage system is at a first fault level; the fault response measure for the first fault level includes cutting off the high-voltage circuit; where I is the real-time current of the grid-type energy storage system, P max is the real-time maximum allowable power, V is the real-time voltage of the grid-type energy storage system, x is the first overcurrent level coefficient, and ΔI is the current error redundancy value of the grid-type energy storage system; In response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, it is determined that the grid-type energy storage system is in a second fault level; the fault response measure for the second fault level includes limiting the output power of the BMS; where y is the second overcurrent level coefficient, and x>y; and In response to the real-time current of the grid-type energy storage system satisfying the formula , and the duration reaches a first preset period, it is determined that the grid-type energy storage system is in the third fault level; the fault response measures of the third fault level include outputting alarm prompt information; where z is the third overcurrent level coefficient, and y>z.

12. A grid-type energy storage system active power overload protection device, wherein the grid-type energy storage system includes a BMS and a PCS; characterized in that: The device is applied to the BMS, and the device includes: A real-time power monitoring module is configured to monitor the output power of the BMS in real time and determine whether the grid-type energy storage system is overloaded according to the real-time output power of the BMS; a real-time maximum allowable power determination module configured to: in response to the grid-type energy storage system being overloaded, determine the real-time maximum allowable power according to the real-time output power of the BMS; wherein the real-time maximum allowable power is the current maximum allowable power of the grid-type energy storage system; and The real-time maximum allowable power sending module is configured to: send the real-time maximum allowable power to the PCS in real time, and the PCS controls the output power of the PCS according to the real-time maximum allowable power.

13. A computer device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the processor runs the computer program stored in the memory, the processor executes the active overload protection method for a grid-type energy storage system according to any one of claims 1 to 11.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the processor executes the active overload protection method for a grid-type energy storage system according to any one of claims 1 to 11.

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