Aging cabinet storage anti-feed system and control method thereof

Abstract

The application discloses an aging cabinet matching storage anti-feedback power grid system and a control method thereof. The aging cabinet matching storage anti-feedback power grid system comprises a power grid connecting device, an electric energy distribution device, a first switch device, a second switch device, an aging cabinet, a load and a storage device. The power grid connecting device is used for connecting to a power grid. The electric energy distribution device is connected with the power grid connecting device and monitors power on the power grid side. The aging cabinet and the load are connected with the first switch device respectively. The first switch device monitors power on the aging cabinet side. The storage device comprises a plurality of storage modules connected with the second switch device respectively. Each storage module is provided with a control unit. The control unit controls the working state of the storage module based on the flow direction relationship between the power on the power grid side and the power on the aging cabinet side, a preset power threshold and state parameters of the storage module. The application can realize the effect of charging and discharging the aging cabinet without feeding back to the power grid without the need for real-time human monitoring and intervention and the need for strict matching of charging and discharging of the aging cabinet.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to an aging cabinet-equipped energy storage and anti-feedback grid system and its control method. Background Technology

[0002] With the rapid development of lithium battery energy storage technology, the application of industrial and commercial energy storage is becoming increasingly accepted and adopted. Because energy storage systems undergo charging or discharging operations during aging tests, especially during discharging which may lead to grid feeding, it is crucial to propose an aging cabinet-storage anti-grid feeding system and its control method to ensure normal aging testing of the energy storage system and prevent grid impact from reverse current.

[0003] Currently, when energy storage aging cabinets undergo discharge testing, the discharged electricity can only be absorbed by the loads within the park. However, there is no way to manage the excess electricity, allowing it to feed back into the grid. To address these issues, the first method is to connect a reverse current alarm device below the transformer where the aging cabinets and other loads share the same transformer. Once discharge to the grid occurs, the alarm will sound, prompting manual intervention to reduce the discharge of the aging cabinets or stop the aging test. The second method is to strictly limit the charging and discharging power of the aging cabinets, allowing some cabinets to charge while others discharge, thus ensuring that the discharged electricity is absorbed by the cabinets that need charging.

[0004] Both of the above methods can prevent power grid feeding to some extent, but they both have obvious limitations:

[0005] The first method requires frequent human intervention, and the discharge power of the aging cabinet needs to be strictly controlled to prevent large current discharge.

[0006] The second method requires a strict ratio between the power of the charging aging cabinet and the power of the discharging aging cabinet at any given time, ensuring that the power of the discharging aging cabinet is not higher than that of the charging aging cabinet at any given time.

[0007] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0008] To overcome the above defects, this invention proposes an aging cabinet power supply and grid protection system and its control method, which solves the problem of reverse current impact on the power grid caused by power fluctuations during aging cabinet testing. It not only eliminates the need for real-time human monitoring and intervention, but also eliminates the need for strict matching of charging and discharging of the aging cabinet, thus achieving the effect of preventing grid feed during aging cabinet charging and discharging.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention discloses an aging cabinet with energy storage and anti-feedback network system, including a power grid connection device, an energy distribution device, a first switching device, a second switching device, an aging cabinet, a load, and an energy storage device;

[0011] The grid connection device is used to connect to the power grid. The power distribution device is connected to the grid connection device to distribute power. The power distribution device is equipped with a grid-side power detection module to monitor grid-side power. The first switch device and the second switch device are respectively connected to the power distribution device. The aging cabinet and the load are respectively connected to the first switch device, and the first switch device is equipped with an aging cabinet-side power detection module to monitor aging cabinet-side power. The energy storage device includes at least one energy storage module. Each energy storage module is connected to the second switch device, and each energy storage module is equipped with a control unit. The control unit is communicatively connected to the grid-side power detection module and the aging cabinet-side power detection module to control the working state of each energy storage module based on the direction and magnitude of the grid-side power and the aging cabinet-side power, as well as a preset power threshold and the state parameters of the energy storage module, so that the grid-side power is maintained within a preset range and the power generated by the aging cabinet flows back to the grid side.

[0012] Preferably, the aging cabinet storage and anti-feedback network system further includes a capacitor compensation device, which is connected to the power distribution device.

[0013] Preferably, the aging cabinet with storage and anti-feedback grid system also includes an alarm, which is communicatively connected to the control unit. The control unit is further configured to control the alarm to issue an alarm when the power on the grid side cannot be maintained within a preset range.

[0014] Preferably, the energy storage device further includes a grid-connected cabinet, which is connected to the second switching device, and each of the energy storage modules is connected to the grid-connected cabinet. The grid-connected cabinet is equipped with an energy storage side detection module for detecting the energy storage side power.

[0015] In a second aspect, the present invention discloses a control method for the aging cabinet storage and anti-feedback network system described in the first aspect, comprising the following steps:

[0016] S1: Monitor the power on the grid side and the power on the aging cabinet side, determine the direction of the power on the aging cabinet side, and if the power on the aging cabinet side is positive, execute step S2; if the power on the aging cabinet side is negative, execute step S4.

[0017] S2: Determine whether the grid-side power is greater than or equal to the starting discharge power of the energy storage module. If so, proceed to step S3; otherwise, each energy storage module enters standby mode.

[0018] S3: Determine whether the SOC or minimum single-cell voltage of each energy storage module is less than or equal to the corresponding cutoff protection lower limit. If so, the corresponding energy storage module enters standby mode; otherwise, the corresponding energy storage module starts discharging.

[0019] S4: Determine whether the grid-side power is less than or equal to the starting charging power of the energy storage module. If yes, proceed to step S5; otherwise, proceed to step S2.

[0020] S5: Determine whether the battery SOC or the highest single-cell voltage of each energy storage module is greater than or equal to the corresponding cutoff protection upper limit. If so, the corresponding energy storage module enters the standby state; otherwise, the corresponding energy storage module starts charging.

[0021] Preferably, step S3 includes:

[0022] S31: The multiple energy storage modules discharge using the grid-side power and distribute the discharge power according to the battery SOC ratio of each energy storage module.

[0023] S32: Determine whether there is a battery SOC or minimum single-cell voltage of the energy storage module that is less than or equal to the corresponding cut-off protection lower limit. If so, the energy storage module whose battery SOC or minimum single-cell voltage is less than or equal to the corresponding cut-off protection lower limit enters the standby state. The remaining energy storage modules that have not entered the standby state redistribute power and discharge according to the battery SOC of each energy storage module.

[0024] S33: Determine whether the grid-side power is greater than or equal to the starting discharge power of each energy storage module. If so, all the remaining energy storage modules that have not entered the standby state will discharge at their rated power until the grid-side power is greater than or equal to the starting charging power of the energy storage module and less than or equal to the starting discharge power of the energy storage module, or until the battery SOC or the lowest single cell voltage of each energy storage module is less than or equal to the corresponding cutoff protection lower limit value. Then, all the remaining energy storage modules that have not entered the standby state will enter the standby state.

[0025] Preferably, step S31, which involves distributing power according to the battery SOC ratio of each energy storage module, includes: for the i-th energy storage module, the power distribution value is:

[0026] ,

[0027] Among them, P f The grid-side power is defined as SOC(i), where SOC(i) represents the battery SOC of the i-th energy storage module, SOC(j) represents the battery SOC of the j-th energy storage module, and N represents the number of energy storage modules.

[0028] Step S32, which involves redistributing power based on the battery SOC of each energy storage module, includes: for the p-th energy storage module, the power allocation value is:

[0029] ,

[0030] Wherein, SOC(p) represents the battery SOC of the p-th energy storage module that has not entered standby state, SOC(q) represents the battery SOC of the q-th energy storage module that has not entered standby state, and M represents the number of energy storage modules that have not entered standby state.

[0031] Preferably, step S5 includes:

[0032] S51: The multiple energy storage modules are charged according to the required charging power, and the power is allocated according to the battery SOC ratio of each energy storage module, wherein the required charging power is equal to the initial charging power of the energy storage module minus the grid-side power.

[0033] S52: Determine whether there is a battery SOC or the highest single cell voltage of the energy storage module that is greater than or equal to the corresponding cut-off protection upper limit. If so, the energy storage module where the battery SOC or the highest single cell voltage is greater than or equal to the corresponding cut-off protection upper limit enters the standby state. The remaining energy storage modules that have not entered the standby state are charged by redistributing power according to the battery SOC of each energy storage module.

[0034] S53: Determine whether the remaining energy storage modules that have not entered standby mode are unable to absorb the required charging power. If so, control all remaining energy storage modules that have not entered standby mode to charge at the rated power. If they still cannot absorb the power, trigger an alarm.

[0035] Preferably, step S51, which involves power allocation charging according to the battery SOC ratio of each energy storage module, includes: for the i-th energy storage module, the allocated charging power value is:

[0036] ,

[0037] Among them, P kc P is the starting charging power of the energy storage module. f The grid-side power is defined as SOC(i), where SOC(i) represents the battery SOC of the i-th energy storage module, SOC(j) represents the battery SOC of the j-th energy storage module, and N represents the number of energy storage modules.

[0038] Step S52, which involves redistributing charging power based on the battery SOC of each energy storage module, includes: for the p-th energy storage module, the allocated charging power value is:

[0039] ,

[0040] Wherein, SOC(p) represents the battery SOC of the p-th energy storage module that has not entered standby state, SOC(q) represents the battery SOC of the q-th energy storage module that has not entered standby state, and M represents the number of energy storage modules that have not entered standby state.

[0041] Thirdly, the present invention discloses a computer-readable storage medium storing a computer program, wherein the computer program is configured to be run by a processor in accordance with the steps of the control method described in the second aspect.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows: The aging cabinet energy storage and grid-fed protection system and its control method disclosed in the present invention, by configuring multiple energy storage modules in the grid-fed protection system, automatically adjusts its working state based on the flow relationship (e.g., direction and magnitude) between the power on the grid side and the power on the aging cabinet side, as well as preset power thresholds and energy storage module state parameters, thereby absorbing the electricity released by the aging cabinet, keeping the power on the grid side within a preset range, and preventing the power generated by the aging cabinet from flowing back to the grid side, i.e., preventing it from feeding back into the grid; by dynamically coordinating the charging and discharging of the energy storage modules, adaptive consistency of grid power fluctuations is achieved, fundamentally preventing grid feeding; therefore, through this system and its control method, real-time manual monitoring and access during the charging and discharging test of the aging cabinet can be eliminated, and the effect of preventing the aging cabinet from feeding back into the grid can be achieved without strictly matching the charging and discharging of the aging cabinet.

[0043] Other beneficial effects of the embodiments of the present invention will be further described below. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of the aging cabinet with storage and anti-feedback network system according to a specific embodiment of the present invention;

[0045] Figure 2This is a flowchart of the control method for the aging cabinet with storage and anti-feedback network system according to Embodiment 2 of the present invention;

[0046] Figure 3 This is a flowchart of the control method for the aging cabinet storage and anti-feedback network system according to a specific embodiment of the present invention;

[0047] Figure 4 yes Figure 3 Workflow diagram during discharge;

[0048] Figure 5 yes Figure 4 Workflow diagram during charging.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Transformer cabinet; 101-Transformer;

[0051] 2-Power receiving cabinet; 201-First multi-function meter; 202-First surge protector; 203-First molded case circuit breaker; 204-Anti-reverse current meter transformer;

[0052] 3-Capacitor compensation cabinet;

[0053] 4-First outgoing line cabinet; 401-Second multi-function meter; 402-Second molded case circuit breaker; 403-Multi-function meter transformer;

[0054] 5-Second outgoing line cabinet; 501-Third multi-function instrument; 502-Third molded case circuit breaker;

[0055] 6-Grid-connected cabinet; 601-Fourth multi-function meter; 602-Second surge protector; 603-Fourth molded case circuit breaker; 604-Meter transformer; 605-Fifth molded case circuit breaker;

[0056] G - Power grid; A - Other loads; B - Aging cabinet;

[0057] ES_1 - Energy storage cabinet 1; ES_2 - Energy storage cabinet 2; ES_N - Energy storage cabinet N. Detailed Implementation

[0058] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0059] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for both fixing and circuit / signal connectivity.

[0060] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0062] To overcome the shortcomings of the prior art, the present invention provides a system and control method for configuring an energy storage cabinet under the same transformer connected to the aging cabinet and other loads to absorb the electricity released by the aging cabinet and prevent it from feeding back into the grid.

[0063] Embodiment 1 of the present invention discloses an aging cabinet power distribution and energy storage system to prevent backflow to the grid, comprising a grid connection device, a power distribution device, a first switch device, a second switch device, an aging cabinet, a load, and an energy storage device. The grid connection device is used to connect to the power grid, and the power distribution device is connected to the grid connection device to distribute power. The power distribution device is equipped with a grid-side power detection module to monitor grid-side power. The first switch device and the second switch device are respectively connected to the power distribution device. The aging cabinet and the load are respectively connected to the first switch device, and the first switch device is equipped with an aging cabinet-side power detection module to monitor aging cabinet-side power. The energy storage device includes at least one energy storage module. Each energy storage module is connected to the second switch device, and each energy storage module is equipped with a control unit. The control unit is communicatively connected to the grid-side power detection module and the aging cabinet-side power detection module to control the working state of each energy storage module based on the flow relationship (e.g., direction and magnitude) of grid-side power and aging cabinet-side power, as well as a preset power threshold and the state parameters of the energy storage module, so as to maintain the grid-side power within a preset range and prevent the power generated by the aging cabinet from flowing back to the grid. Furthermore, the aging cabinet's energy storage and grid protection system also includes a capacitor compensation device and an alarm. The capacitor compensation device is connected to the power distribution device, and the alarm is communicatively connected to the control unit. The control unit is also configured to issue an alarm when the grid-side power cannot be maintained within a preset range. The energy storage device also includes a grid-connected cabinet, which is connected to a second switching device. Each energy storage module is connected to the grid-connected cabinet, which is equipped with an energy storage-side detection module for detecting energy storage-side power. When controlling the operating state of each energy storage module, the control unit also dynamically allocates charging and discharging power according to the battery state of each module, making the battery state of each module more consistent.

[0064] When the control unit determines that all energy storage modules are unable to effectively regulate power (e.g., unable to recharge when fully charged, or unable to discharge when depleted), and the power on the grid side continues to deteriorate towards the feeder and exceeds a higher-level danger threshold, the control unit can send a command to the first switching device to forcibly cut off the power supply circuit of the aging cabinet, terminating the power source at its root. Specifically, a shunt trip is directly added to the first switching device (first molded case circuit breaker 203). After the control unit makes a judgment, it directly outputs a DO signal to the shunt trip on the first switching device (first molded case circuit breaker 203), causing the switch to trip and thus disconnect the circuit. Manual restoration is required when restoring the circuit.

[0065] Specifically, such as Figure 1As shown, the power grid connection device uses transformer cabinet 1, which is directly connected to the power grid G. Transformer cabinet 1 contains transformer 101. The power distribution device uses power receiving cabinet 2, which is connected to transformer cabinet 1. Power receiving cabinet 2 contains a first multi-function meter 201, a first surge protector 202, a first molded case circuit breaker 203, and an anti-reverse current meter transformer 204. The anti-reverse current meter transformer 204 is the power detection module on the power grid side. The capacitor compensation device uses capacitor compensation cabinet 3. The first switching device uses a first outgoing line cabinet 4, which contains a second multi-function meter 401, a second molded case circuit breaker 402, and a multi-function meter transformer 403. The multi-function meter transformer 403 is the power detection module on the aging cabinet side. Aging cabinet B and other loads A are connected to the first outgoing line cabinet 4. Aging cabinet B has four working states: charging, discharging, standby, and shutdown. Other loads A have two working states: running and shutdown. The second switching device uses a second outgoing cabinet 5. The second outgoing cabinet 5 houses a third multi-function meter 501 and a third molded case circuit breaker 502. The energy storage device includes a grid-connected cabinet 6 and multiple energy storage modules. The grid-connected cabinet 6 is connected to the second outgoing cabinet 5. The grid-connected cabinet 6 houses a fourth multi-function meter 601, a second surge protector 602, a fourth molded case circuit breaker 603, a metering transformer 604, and a fifth molded case circuit breaker 605. The metering transformer 604 is the energy storage side power detection module. An alarm (not shown in the diagram) is installed in the aging cabinet B room. The capacitor compensation cabinet 3, the first outgoing cabinet 4, and the second outgoing cabinet 5 are respectively connected to the power receiving cabinet 2. Specifically, the capacitor compensation cabinet 3, the first outgoing cabinet 4, and the second outgoing cabinet 5 are independent of each other and connected in parallel to the 0.4kV AC bus.

[0066] Multiple energy storage modules comprise N energy storage cabinets, designated as ES_1, ES_2, ..., ES_N. Each cabinet is connected to grid-connected cabinet 6. The EMS (Energy Management System) within each cabinet can be configured with its starting charging and discharging power. When the set starting charging power is reached, the cabinet begins charging; when the set starting discharging power is reached, the cabinet begins discharging. Otherwise, the cabinet is in standby or off state. The BMS (Battery Management System) within each cabinet can be configured with maximum battery SOC (State of Charge) and maximum single-cell voltage cutoff protection limits, as well as minimum battery SOC and minimum single-cell voltage cutoff protection limits. Once these limits are triggered, the cabinet enters a protection state, i.e., it enters standby mode.

[0067] The anti-reverse current meter transformer 204 and the multi-functional meter transformer 403 have forward and reverse current detection functions, respectively. When the anti-reverse current meter transformer 204 generates a forward current, it draws power directly from the power grid G; when a reverse current occurs, it discharges back into the power grid G. When the multi-functional meter transformer 403 generates a forward current, the aging cabinet B is charging; when a reverse current occurs, the aging cabinet B is discharging. The meter transformer 604 has forward and reverse power statistics functions. When the meter transformer 604 generates a forward current, the energy storage cabinet is charging; when a reverse current occurs, the energy storage cabinet is discharging. The alarm is controlled by the DO port (digital output interface) inside the energy storage cabinet's EMS via communication; that is, power-on will cause the alarm to sound.

[0068] The aging cabinet with energy storage and anti-backflow protection system disclosed in this invention includes a transformer cabinet 1, a power receiving cabinet 2, a capacitor compensation cabinet 3, a first outgoing line cabinet 4, a second outgoing line cabinet 5, and a grid-connected cabinet 6. The power receiving cabinet 2 is connected to the transformer cabinet 1. The capacitor compensation cabinet 3, the first outgoing line cabinet 4, and the second outgoing line cabinet 5 are respectively connected to the power receiving cabinet 2. The aging cabinet B and other loads A are connected to the first outgoing line cabinet 4. The grid-connected cabinet 6 is connected to the second outgoing line cabinet 5. N energy storage cabinets are connected to the grid-connected cabinet 6. The anti-backflow meter transformer 204 is installed in the power receiving cabinet 2, the multi-functional meter transformer 403 is installed in the first outgoing line cabinet 4, the metering meter transformer 604 is installed in the grid-connected cabinet 6, and the alarm is installed in the room of the aging cabinet B. The invention compares the grid-side power sensed by the anti-reverse current meter transformer 204 with the start-charging and start-discharging power set in the EMS of each energy storage cabinet (the start-charging and start-discharging power set in the EMS of each energy storage cabinet are preset power thresholds). It also compares the battery SOC, highest single-cell voltage, lowest single-cell voltage with the upper and lower cut-off protection limits (these are the state parameters of the energy storage module). This allows the energy storage cabinet to automatically select between charging, discharging, and standby operation to absorb the electricity released by the aging cabinet B and prevent it from feeding back into the grid. Simultaneously, if the energy storage cabinet is unable to absorb the electricity released by the aging cabinet B, an alarm sounds, prompting manual intervention to control the aging cabinet. This invention eliminates the need for real-time manual monitoring and intervention during the charging and discharging testing of the aging cabinet B, and achieves the effect of preventing the aging cabinet B from feeding back into the grid without requiring strict matching of charging and discharging times.

[0069] like Figure 2 As shown, Embodiment 2 of the present invention discloses a control method for an aging cabinet storage and anti-feedback network system based on Embodiment 1, comprising the following steps:

[0070] S1: Monitor the power on the grid side and the power on the aging cabinet side, and determine the direction of the power on the aging cabinet side. If the power on the aging cabinet side is positive, proceed to step S2; if the power on the aging cabinet side is negative, proceed to step S4.

[0071] The power on the aging cabinet side is sensed by the multi-function meter transformer 403. When the power on the aging cabinet side is positive, it means that the power on the aging cabinet side is positive and the current is positive, and the aging cabinet B is charging. When the power on the aging cabinet side is negative, it means that the power on the aging cabinet side is negative and the current is reverse, and the aging cabinet B is discharging.

[0072] S2: Determine whether the grid-side power is greater than or equal to the starting discharge power of the energy storage module. If so, proceed to step S3; otherwise, the energy storage module enters standby mode.

[0073] S3: Determine whether the SOC or minimum single-cell voltage of each energy storage module is less than or equal to the corresponding cutoff protection lower limit. If so, the corresponding energy storage module enters standby mode; otherwise, the corresponding energy storage cabinet begins to discharge.

[0074] This step S3 specifically includes:

[0075] S31: Multiple energy storage modules discharge using grid-side power and distribute the discharge power according to the battery SOC ratio of each energy storage module.

[0076] The power allocation discharge according to the battery SOC ratio of each energy storage module includes: For the i-th energy storage module, its discharge power allocation value is:

[0077] ,

[0078] Among them, P f SOC(i) represents the SOC of the i-th energy storage module, SOC(j) represents the SOC of the j-th energy storage module, and N represents the number of energy storage modules.

[0079] S32: Determine whether there is an energy storage module whose battery SOC or lowest single-cell voltage is less than or equal to the corresponding cut-off protection lower limit. If so, the energy storage module whose battery SOC or lowest single-cell voltage is less than or equal to the corresponding cut-off protection lower limit enters the standby state. The remaining energy storage modules that have not entered the standby state will redistribute power and discharge according to the battery SOC of each energy storage module.

[0080] The power redistribution discharge based on the battery SOC of each energy storage module includes: For the p-th energy storage module, its discharge power allocation value is:

[0081] ,

[0082] Where SOC(p) represents the battery SOC of the p-th energy storage module that has not entered standby mode, SOC(q) represents the battery SOC of the q-th energy storage module that has not entered standby mode, and M represents the number of energy storage modules that have not entered standby mode.

[0083] S33: Determine whether the grid-side power is greater than or equal to the starting discharge power of each energy storage module. If so, all other energy storage modules that have not entered standby mode will discharge at rated power until the grid-side power is greater than or equal to the starting charging power of the energy storage module and less than or equal to the starting discharge power of the energy storage module, or until the battery SOC or the lowest single cell voltage of each energy storage module is less than or equal to the corresponding cutoff protection lower limit value. Then, all other energy storage modules that have not entered standby mode will enter standby mode.

[0084] S4: Determine whether the grid-side power is less than or equal to the starting charging power of the energy storage module. If yes, proceed to step S5; otherwise, proceed to step S2.

[0085] S5: Determine whether the battery SOC or the highest single-cell voltage of each energy storage module is greater than or equal to the corresponding cutoff protection upper limit. If so, the corresponding energy storage module enters standby mode; otherwise, the corresponding energy storage cabinet starts charging.

[0086] This step S5 specifically includes:

[0087] S51: Multiple energy storage modules are charged according to the required charging power, and the power is allocated according to the battery SOC ratio of each energy storage module. The required charging power is equal to the initial charging power of the energy storage module minus the grid-side power.

[0088] The power allocation charging according to the battery SOC ratio of each energy storage module includes: For the i-th energy storage module, its charging power allocation value is:

[0089] ,

[0090] Among them, P kc P is the initial charging power of the energy storage module. f SOC(i) represents the SOC of the i-th energy storage module, SOC(j) represents the SOC of the j-th energy storage module, and N represents the number of energy storage modules.

[0091] S52: Determine whether there is a battery SOC or the highest single cell voltage of an energy storage module that is greater than or equal to the corresponding cut-off protection upper limit. If so, the energy storage module where the battery SOC or the highest single cell voltage is greater than or equal to the corresponding cut-off protection upper limit enters the standby state. The remaining energy storage modules that have not entered the standby state are charged by redistributing power according to the battery SOC of each energy storage module.

[0092] The power redistribution charging based on the battery SOC of each energy storage module includes: For the p-th energy storage module, its charging power allocation value is:

[0093] ,

[0094] Where SOC(p) represents the battery SOC of the p-th energy storage module that has not entered standby mode, SOC(q) represents the battery SOC of the q-th energy storage module that has not entered standby mode, and M represents the number of energy storage modules that have not entered standby mode.

[0095] S53: Determine whether the remaining energy storage modules that have not entered standby mode are unable to absorb the required charging power. If so, control all remaining energy storage modules that have not entered standby mode to charge at the rated power. If they still cannot absorb the power, trigger an alarm.

[0096] The following detailed description of the control method for the aging cabinet storage and anti-feedback network system disclosed in Embodiment 2 of the present invention will be provided with reference to specific embodiments.

[0097] In this specific embodiment, a total of N energy storage cabinets (ES_1, ES_2, ..., ES_N, N=1, 2, 3...) are connected to the grid-connected cabinet 6, and their corresponding battery SOCs are SOC(1), SOC(2), ..., SOC(N), respectively. The starting charging power of the N energy storage cabinets EMS is set to P. kc The initial discharge power is P kf All are the same. In addition, the grid-side power detected by the anti-reverse current meter transformer 204 is set to P. f The power detected by the multi-functional meter transformer 403 on the aging cabinet side is P. d The energy storage side power detected by the meter transformer 604 is P. e In the aging cabinet storage and feedback network system of this case, P d The value could be positive or negative, requiring logical judgment. (P) kc P kf P f P e Negative values ​​will not occur.

[0098] First, the initial discharge power Pkf It always needs to be greater than the initial charging power P. kc Second, the initial charging power P kc The value must always be greater than or equal to 0. Generally, to maximize the utilization of the energy storage cabinet, a value between 5-10kW is selected to prevent backflow power P. f A negative value appears, so when P f Less than P kc When the power is 5-10kW, the energy storage cabinet should be started charging immediately; third, the discharge power P should begin. kf Generally, a power of 30kW or higher is chosen to avoid the energy storage cabinet from drying out easily.

[0099] like Figure 3 As shown, the control method for the aging cabinet storage and anti-feedback network system in this specific embodiment includes the following steps:

[0100] A1: When the aging cabinet B starts running, first determine the power P on the aging cabinet side. d If the value is positive, it indicates a positive current and aging cabinet B is charging. At this time, step A2 is executed. If the value is negative, it indicates a reverse current and aging cabinet B is discharging. At this time, step A4 is executed.

[0101] Among them, the grid-side power P f A positive value indicates power is drawn from the grid, while a negative value indicates power is fed back to the grid. However, in this case, the grid-side power P... f Negative values ​​will not occur; aging cabinet side power P d A positive value indicates that aging cabinet B is charging (drawing power from the system or the grid), and a negative value indicates that aging cabinet B is discharging (supplying power to the system or feeding power back to the grid).

[0102] A2: Determine the grid-side power P f Is it higher than the starting discharge power P set by EMS? kf If yes, proceed to step A3; otherwise, all energy storage modules enter standby mode.

[0103] A3: Determine whether the SOC and minimum single-cell voltage of the batteries in the N energy storage cabinets have reached the corresponding cutoff protection lower limit. If not, the energy storage cabinet starts discharging; otherwise, the energy storage cabinet enters standby mode.

[0104] Among them, the lower limit of the cutoff protection for battery SOC is about 5% to 10%, and the lower limit of the cutoff protection for the lowest single cell voltage is about 2.5V to 2.9V.

[0105] Combination Figure 4 There are N energy storage cabinets, and the discharge power of each energy storage cabinet is calculated as follows:

[0106] The discharge power of the first energy storage cabinet is: P f *SOC(1) / (SOC(1)+SOC(2)+…+SOC(N));

[0107] The discharge power of the second energy storage cabinet is: P f *SOC(2) / (SOC(1)+SOC(2)+…+SOC(N)); ......

[0108] The discharge power of the Nth energy storage cabinet is: P f *SOC(N) / (SOC(1)+SOC(2)+…+SOC(N)).

[0109] If any one of the energy storage cabinets reaches the discharge cutoff protection lower limit, that cabinet will directly enter standby mode, and the discharge power of the remaining cabinets will be redistributed according to the calculation method described above. If multiple energy storage cabinets enter standby mode due to reaching the discharge cutoff protection lower limit, condition P... f ≥P kf The condition remains valid; all remaining energy storage cabinets discharge at rated power until P... kc ≤P f ≤P kf If the condition is met, all remaining energy storage cabinets will enter standby mode; however, if all remaining energy storage cabinets discharge at rated power and still cannot meet P... kc ≤P f ≤P kf The remaining energy storage cabinets continue to discharge at their rated power until all energy storage cabinets reach the discharge cutoff protection lower limit and enter standby mode.

[0110] Furthermore, if one energy storage cabinet reaches the discharge cutoff protection lower limit (i.e., the battery SOC or the lowest single-cell voltage of that energy storage cabinet reaches the cutoff protection lower limit), the discharge power of the remaining energy storage cabinets is calculated as follows (the remaining N-1 energy storage cabinets are renumbered, i.e., 1#, 2#, 3#, ..., (N-1)#):

[0111] The discharge power of the first energy storage cabinet is: P f *SOC(1) / (SOC(1)+SOC(2)+…+SOC(N-1));

[0112] The discharge power of the second energy storage cabinet is: P f *SOC(2) / (SOC(1)+SOC(2)+…+SOC(N-1)); ......

[0113] The discharge power of the (N-1)th energy storage cabinet is: P kf *SOC(N-1) / (SOC(1)+SOC(2)+…+SOC(N-1)).

[0114] In a specific example, there are a total of 10 energy storage cabinets (N=10), each with a rated power of 100kW, and the set initial discharge power P... kf =400kW, starting charging power P kc =50kW, the grid-side power P detected by the anti-reverse current meter transformer 204 f =500kW, satisfying condition P f ≥P kf At this point, assuming 5 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 5 energy storage cabinets will all discharge at a power of 100kW; assuming 6 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 4 energy storage cabinets will all discharge at a power of 100kW, and the grid-side power P... f =500kW minus 4 energy storage cabinets * rated power 100kW, the remaining 100kW is supplemented by the grid; assuming 7 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 3 energy storage cabinets will each discharge at 100kW power, and the grid-side power P f =500kW minus 3 energy storage cabinets * rated power 100kW, the remaining 200kW is supplemented by the grid.

[0115] After a period of discharge, the grid-side power P detected by the anti-reverse current meter transformer 204 f =300kW, satisfying condition P kc ≤P f ≤P kf At this point: Assuming 3 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 7 energy storage cabinets all enter standby mode; assuming 4 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 6 energy storage cabinets all enter standby mode; assuming 8 energy storage cabinets reach the lower limit of the cutoff protection, the remaining 2 energy storage cabinets all enter standby mode. That is, as long as P is satisfied... kc ≤P f ≤P kf If the deadline condition is not met, the device will enter standby mode; if the deadline condition is met, the device is already in standby mode.

[0116] A4: Determine the grid-side power P f Is it higher than the starting charging power P set by EMS? kc If the value is small, proceed to step A5; otherwise, return to step A2.

[0117] A5: Determine whether the SOC and highest single-cell voltage of the batteries in N energy storage cabinets have reached the corresponding cutoff protection limit. If so, all energy storage cabinets will enter standby mode, and the EMS will power on the alarm through the DO port inside the EMS, causing the alarm to sound. At this time, manual intervention is required, and the aging cabinet will stop discharging. If not, the energy storage cabinet will start charging.

[0118] Among them, the upper limit of the cutoff protection for battery SOC is about 90%~95%, and the upper limit of the cutoff protection for the lowest single cell voltage is about 3.5V~3.6V.

[0119] Combination Figure 5 There are N energy storage cabinets, and the charging power of each energy storage cabinet is calculated as follows:

[0120] The charging power of the first energy storage cabinet is: (P) kc -P f )*(1-SOC(1)) / [(1-SOC(1))+(1-SOC(2))+…+(1-SOC(N))];

[0121] The charging power of the second energy storage cabinet is: (P) kc -P f )*(1-SOC(2)) / [(1-SOC(1))+(1-SOC(2))+…+(1-SOC(N))]; ......

[0122] The charging power of the Nth energy storage cabinet is: (P kc -P f )*(1-SOC(N)) / [(1-SOC(1))+(1-SOC(2))+…+(1-SOC(N))].

[0123] If any one of the energy storage cabinets reaches the charging cutoff protection limit, the energy storage cabinet will directly enter standby mode, and the power will be redistributed according to the calculation method described above. If multiple energy storage cabinets enter standby mode due to reaching the charging cutoff protection limit, the remaining energy storage cabinets cannot be utilized using the above method (P). kc -P f ) power, that is, all remaining energy storage cabinets are charged at their rated power; and if even if all remaining energy storage cabinets are charged at their rated power, the energy cannot be absorbed (P kc -P f The remaining energy storage cabinets are in standby mode. The EMS controls the DO port inside the EMS to power the alarm, causing the alarm to sound. At this time, manual intervention is required to stop the aging cabinet from discharging.

[0124] In step A3 above, during discharge, the energy storage cabinets with larger SOCs discharge with higher power, and those with smaller SOCs discharge with lower power, to ensure that the SOCs of each energy storage cabinet are as close as possible in the later stages. In step A5, during charging, the energy storage cabinets with larger SOCs charge with lower power, and those with smaller SOCs charge with higher power, to ensure that the SOCs of each energy storage cabinet are as close as possible in the later stages. This avoids inconsistent charging or discharging currents within each energy storage cabinet, preventing extremely large or small currents. By calculating the discharge or charging power as described above, the SOC of each energy storage cabinet is made as uniform as possible in the later stages (or, the discharge capacity is made as close to uniform as possible in the later stages), thereby increasing the lifespan of the energy storage cabinets.

[0125] The aging cabinet storage and anti-feedback network system and its control method disclosed in Embodiments 1 and 2 of this invention have the following advantages:

[0126] (1) It can effectively prevent the electricity released by the aging cabinet from being fed back to the grid.

[0127] (2) It can eliminate the need for real-time human monitoring and intervention during the charging and discharging test of the aging cabinet, thus avoiding time-consuming and labor-intensive phenomena. Specifically, in the prior art, no energy storage cabinet is configured. At this time, when the aging cabinet releases electricity, an alarm needs to be triggered and human intervention is required. Otherwise, it is impossible to control whether the electricity released by the aging cabinet is less than the electricity consumed by the load. If it is greater, it means that the load cannot absorb the electricity released by the aging cabinet, resulting in the phenomenon of discharge to the grid. However, this invention configures multiple energy storage cabinets, which can absorb the electricity released by the aging cabinet after it has been absorbed by the load, preventing the unabsorbed electricity from feeding back to the grid. As long as the power of the configured energy storage cabinet is large enough, the phenomenon of feeding back to the grid will basically not occur.

[0128] (3) It can automatically coordinate the balance between the charging and discharging power of the energy storage cabinet and the aging cabinet, eliminating the need for a strict ratio of charging and discharging power for the aging cabinet. Specifically, in the prior art, an alarm and manual intervention are required when the aging cabinet discharges electricity. Therefore, in the absence of an energy storage cabinet, the general practice is to strictly configure the power of the charging and discharging components inside the aging cabinet, that is, only requiring the charging power of the internal charging components to be greater than or equal to the power of the discharging components. However, in this invention, after configuring an energy storage cabinet, it is not necessary to implement such a strict ratio. Moreover, after the energy storage cabinet is programmed, the EMS can automatically coordinate the energy storage cabinet to absorb excess electricity between the aging cabinet and the load, preventing excess electricity from being fed back to the grid.

[0129] Embodiment 3 of the present invention discloses a computer-readable storage medium storing a computer program, wherein the computer program is configured to be run by a processor to perform the steps of the control method for the aging cabinet distribution and anti-feedback network system in the preferred embodiment 2 described above.

[0130] Optionally, the aforementioned computer-readable storage media may include, but are not limited to, various media capable of storing computer programs, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0131] The background section of this invention may include background information about the problems or circumstances surrounding the invention, rather than a description of prior art by others. Therefore, the content included in the background section is not an admission of prior art by the applicant.

[0132] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification without contradiction. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope defined by the appended claims.

Claims

1. An aging cabinet with a storage anti-feedthrough network system, characterized in that, The system comprises a grid connection device, an electric energy distribution device, a first switch device, a second switch device, an aging cabinet, a load and an energy storage device. The grid connection device is used for connecting to a power grid, the electric energy distribution device is connected to the grid connection device for distributing electric energy, the electric energy distribution device is provided with a grid-side power detection module for monitoring grid-side power; the first switch device and the second switch device are connected to the electric energy distribution device, the aging cabinet and the load are connected to the first switch device, and the first switch device is provided with an aging cabinet-side power detection module for monitoring aging cabinet-side power; the energy storage device comprises at least one energy storage module, each energy storage module is connected to the second switch device, and each energy storage module is provided with a control unit, the control unit is in communication connection with the grid-side power detection module and the aging cabinet-side power detection module, so as to control the working state of each energy storage module based on the flow direction relationship of the grid-side power and the aging cabinet-side power, and the preset power threshold and the state parameters of the energy storage module, so that the grid-side power is maintained within a preset range, and the power generated by the aging cabinet is prevented from flowing reversely to the grid side.

2. The system of claim 1, wherein, The system further comprises a capacitor compensation device connected to the electric energy distribution device.

3. The system of claim 1, wherein the system further comprises a feedback network. The system further comprises an alarm in communication connection with the control unit, and the control unit is further configured to control the alarm to issue an alarm when the grid-side power cannot be maintained within a preset range.

4. The system of claim 1, wherein, The energy storage device further comprises a grid-connected cabinet connected to the second switch device, and each energy storage module is connected to the grid-connected cabinet, and the grid-connected cabinet is provided with an energy storage-side detection module for detecting energy storage-side power.

5. A control method for the anti-feedant net system of the aging cabinet, as claimed in any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1: monitoring the grid-side power and the aging cabinet-side power, judging the direction of the aging cabinet-side power, if the aging cabinet-side power is positive, executing step S2, if the aging cabinet-side power is negative, executing step S4; S2: judging whether the grid-side power is greater than or equal to the start discharging power of the energy storage module, if yes, executing step S3; otherwise, each energy storage module enters a standby state; S3: judging whether the battery SOC or the lowest single cell voltage of each energy storage module is less than or equal to the corresponding lower limit value of the cut-off protection, if yes, the corresponding energy storage module enters a standby state, otherwise, the corresponding energy storage module starts discharging; S4: judging whether the grid-side power is less than or equal to the start charging power of the energy storage module, if yes, executing step S5, otherwise, executing step S2; S5: judging whether the battery SOC or the highest single cell voltage of each energy storage module is greater than or equal to the corresponding upper limit value of the cut-off protection, if yes, the corresponding energy storage module enters a standby state, otherwise, the corresponding energy storage module starts charging.

6. The control method according to claim 5, characterized by Step S3 comprises: S31: a plurality of energy storage modules discharge with the grid-side power, and the power is distributed and discharged according to the battery SOC proportion of each energy storage module; S32: determining whether there is a battery SOC or a lowest single cell voltage of the energy storage module less than or equal to the corresponding lower limit of the cutoff protection, if so, the energy storage module with the battery SOC or the lowest single cell voltage less than or equal to the corresponding lower limit of the cutoff protection enters the standby state, and the rest of the energy storage modules not entering the standby state respectively perform power redistribution discharge according to the battery SOC of each energy storage module; S33: determining whether the grid-side power is greater than or equal to the starting discharge power of each energy storage module, if so, all the rest of the energy storage modules not entering the standby state discharge at the rated power until the grid-side power is greater than or equal to the starting charge power of the energy storage module and less than or equal to the starting discharge power of the energy storage module, or until the battery SOC or the lowest single cell voltage of each energy storage module is less than or equal to the corresponding lower limit of the cutoff protection, respectively, then all the rest of the energy storage modules not entering the standby state enter the standby state.

7. The control method according to claim 6, wherein, the power distribution discharge according to the battery SOC proportion of each energy storage module in step S31 comprises that for the i-th energy storage module, the distribution value of the discharge power is: ， where P f is the grid-side power, SOC(i) represents the battery SOC of the i-th energy storage module, SOC(j) represents the battery SOC of the j-th energy storage module, and N represents the number of energy storage modules. the power redistribution discharge according to the battery SOC of each energy storage module in step S32 comprises that for the p-th energy storage module, the distribution value of the discharge power is: ， wherein SOC(p) represents the battery SOC of the p-th energy storage module not entering the standby state, SOC(q) represents the battery SOC of the q-th energy storage module not entering the standby state, and M represents the number of the energy storage modules not entering the standby state.

8. The control method according to claim 5, characterized by, Step S5 comprises: S51: charging a plurality of energy storage modules according to the required charging power, and distributing the charging power according to the battery SOC proportion of each energy storage module, wherein the required charging power is equal to the starting charging power of the energy storage module minus the grid-side power; S52: determining whether there is a battery SOC or a highest single cell voltage of the energy storage module greater than or equal to the corresponding upper limit of the cutoff protection, if so, the energy storage module with the battery SOC or the highest single cell voltage greater than or equal to the corresponding upper limit of the cutoff protection enters the standby state, and the rest of the energy storage modules not entering the standby state respectively perform power redistribution charging according to the battery SOC of each energy storage module; S53: determining whether the rest of the energy storage modules not entering the standby state cannot accommodate the required charging power, if so, controlling all the rest of the energy storage modules not entering the standby state to charge at the rated power, and if still cannot accommodate, triggering an alarm.

9. The control method according to claim 8, wherein, the power distribution charging according to the battery SOC proportion of each energy storage module in step S51 comprises that for the i-th energy storage module, the distribution value of the charging power is: ， wherein P kc is the initial charging power of the energy storage module, P f is the grid-side power, SOC(i) represents the battery SOC of the i-th energy storage module, SOC(j) represents the battery SOC of the j-th energy storage module, and N represents the number of energy storage modules. The power re-distribution charging according to the battery SOC of each of the energy storage modules in step S52 includes: for the pth energy storage module, the allocated value of the charging power is: ， wherein SOC(p) represents the battery SOC of the pth energy storage module which does not enter the standby state, SOC(q) represents the battery SOC of the qth energy storage module which does not enter the standby state, and M represents the number of the energy storage modules which do not enter the standby state.

10. A computer readable storage medium characterized by, The computer readable storage medium stores a computer program, wherein the computer program is configured to be run by a processor to execute the steps of the control method in any one of claims 5 to 9.

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