Energy storage control method and system applied to intelligent computing center scenario

Abstract

The application relates to an energy storage control method and system applied to a smart center scene, wherein, compared with the prior art, the power grid is connected to a direct-current bus through a solid-state transformer, and the fixed transformer converts alternating current of the power grid into direct current; an energy storage system and a data center load are hung on the direct-current bus; wherein the energy storage system comprises multiple subsystems, each of which comprises an energy storage medium and a power electronic converter, and the energy storage medium is hung on the direct-current bus in parallel through the corresponding power electronic converter; the subsystems realize the bidirectional flow of the energy storage medium energy through the power electronic converters, and the two-end voltage or the state of charge of the energy storage medium of each subsystem is real-timely regulated through the synergistic effect of low-end power compensation and high-end regulation, so that the overall consistency of the energy state during the parallel operation of the multiple subsystems is effectively guaranteed, and the system reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, and in particular to an energy storage control method and system applied to intelligent computing center scenarios. Background Technology

[0002] The energy storage system applied in AIDC (AI Data Center) intelligent computing center scenarios consists of a solid-state transformer (SST), the energy storage system, and the data center load, with the energy storage system connected to the SST DC bus. The system operates according to the following power balance principle: when the load power exceeds the grid's power supply capacity, the energy storage system discharges to make up for the power shortfall; when the load power is lower than the grid's power supply capacity, the energy storage system charges to the target value of the difference between the grid power and the load power.

[0003] In practical engineering, due to cost constraints, grid capacity is usually configured based on the total installed capacity of loads such as data centers, with little margin, resulting in energy storage systems being able to charge with only a small differential power. Meanwhile, the overall capacity of energy storage systems is typically in the MW (megawatt) range, composed of multiple energy storage subsystems connected in parallel. The consistency of the terminal voltage or state of charge (SOC) of the energy storage medium among the subsystems directly affects the overall energy utilization efficiency and available depth of discharge of the system, and is a key factor affecting the economic efficiency and reliability of system operation.

[0004] During the low-power charging process of an energy storage system using the power difference between the grid and the load, multiple subsystems are simultaneously charging. Due to power distribution deviations or differences in response characteristics, the actual charging power obtained by each subsystem is often uneven, leading to inconsistencies in the terminal voltage or state of charge (SOC) of the energy storage medium among the subsystems. This inconsistency in terminal voltage or SOC not only directly restricts the overall energy utilization rate and usable depth of discharge of the energy storage system, but also triggers the "weakest link effect"—that is, the system performance is limited by the subsystem in the worst state, severely weakening the energy dispatch capability and operational consistency of the energy storage system throughout its entire lifecycle. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an energy storage control method and system applicable to intelligent computing center scenarios.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An energy storage control method for intelligent computing center scenarios provided by the present invention includes the following steps:

[0008] Connection steps: The power grid is connected to the DC bus via a solid-state transformer, which converts the AC power from the grid to DC power. The energy storage system and data center loads are connected to the DC bus. The energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter. The energy storage medium is connected in parallel to the DC bus via a corresponding power electronic converter. The subsystems achieve bidirectional energy flow through the energy storage medium via the power electronic converter.

[0009] Control steps: Through the synergistic effect of low-end power replenishment and high-end regulation, the voltage or state of charge of the energy storage medium at both ends of each subsystem is regulated in real time.

[0010] Compared with existing technologies, this invention adopts a control strategy that combines independent charging of a single subsystem with polling charging of multiple subsystems. Through the synergistic effect of low-end power replenishment and high-end regulation, the terminal voltage or state of charge (SOC) of the energy storage medium of each subsystem is controlled in real time to be close to the target value, thereby effectively ensuring the overall consistency of energy state when multiple subsystems are running in parallel and improving system reliability.

[0011] Preferably, the control steps include the following steps:

[0012] Low-end charging steps: The energy storage system polls the charging status, sequentially and controllably charging the subsystems. When the first subsystem... i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; when the voltage across the energy storage medium of each subsystem... If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging will stop; each subsystem will then sequentially begin polling charging until the target upper limit value is reached.

[0013] High-end charging steps: When the voltage across the energy storage medium of each subsystem... All values ​​are ≥ the low-end charging cutoff threshold. Subsystems are sequentially charged to the target upper limit. If the energy storage system enters high-end charging, subsystems are sequentially and controllably charged until the target upper limit is reached. j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

[0014] Preferably, in the connection step, each subsystem further includes a soft-start resistor and a switch, the negative terminal of each energy storage medium is connected to the negative output terminal of the corresponding power electronic converter; the positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch, and the other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal of the power electronic converter.

[0015] In the low-end charging step, if the energy storage system is starting charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging start threshold, the subsystem is ready for polling charging. The switches of all subsystems are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging. The energy storage system is in polling charging state.

[0016] Preferably, in the low-end charging step, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem is... From a high point, when the first j Voltage across the energy storage medium of the sleeve system ≤ Discharge cutoff threshold, only the j-th subsystem is charged, when the j-th subsystem is charged. j Voltage across the energy storage medium of the sleeve system When the low-end charging threshold is reached, charging of the j-th subsystem is stopped; when the low-end charging threshold is reached, charging of the j-th subsystem is stopped. j Voltage across the energy storage medium of the sleeve system ≤Low-end fast charging threshold, the j-th subsystem is charging, when the th j Voltage across the energy storage medium of the sleeve system If the low-end charging threshold is reached, charging stops, and simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the threshold. If the low-end charging threshold is reached or exceeded, stop low-end polling charging. The energy storage system switches to standby mode or polls for charging status.

[0017] Preferably, in the low-end charging step, if the energy storage system is in a discharging state, the voltage across the energy storage medium of the subsystem is... From a high point, when the first j Voltage across the energy storage medium of the sleeve system When the discharge cutoff threshold is ≤, the energy storage system stops discharging and switches to standby mode or polling charging mode.

[0018] Preferably, in the high-end charging step, the voltage across the energy storage medium of each subsystem is... After equalization charging reaches the upper limit threshold, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem... Or the remaining power of the energy storage medium SOC Falling from a high:

[0019] When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end energy replenishment threshold, only the j-th subsystem is charged, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium When the charging completion threshold is reached, charging will stop.

[0020] When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end fast charging threshold, the j-th subsystem is charging, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium Once the charging completion threshold is reached, charging stops; simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the maximum value. Or, if the remaining SOC of the energy storage medium is greater than or equal to the upper limit threshold for charging completion, stop polling for charging; The system enters standby mode.

[0021] Preferably, when the voltage across the energy storage medium of each subsystem... Alternatively, after the remaining state of charge (SOC) of the energy storage medium reaches the upper limit threshold for completion of charging, if the system is in a discharging state, the subsystem... Falling from a high point: When the j-th subsystem When the discharge threshold is ≤, the system stops discharging and begins the low-end charging process.

[0022] The present invention also provides an energy storage control system for intelligent computing center scenarios, comprising a power grid, a solid-state transformer, a DC bus, an energy storage system, a data center load, and a control module; The power grid is connected to the DC bus via a solid-state transformer, which converts the AC power of the grid into DC power. The energy storage system and data center loads are connected to the DC bus. The energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter. The energy storage medium is connected in parallel to the DC bus through the corresponding power electronic converter. The subsystems achieve bidirectional energy flow of the energy storage medium through the power electronic converter.

[0023] The control module uses the combined action of low-end power replenishment and high-end regulation to control the voltage or state of charge of the energy storage medium at both ends of each subsystem in real time.

[0024] Preferably, the control module includes the following modules:

[0025] Low-end charging module: The energy storage system uses a polling charging status to controllably charge the subsystems sequentially. When the charging status is polled, the subsystem is charged in turn. i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; when the voltage across the energy storage medium of each subsystem... If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging will stop; each subsystem will then sequentially begin polling charging until the target upper limit value is reached.

[0026] High-end charging module: When the voltage across the energy storage medium of each subsystem All values ​​are ≥ the low-end energy replenishment cutoff threshold, and the subsystems are sequentially polled and charged to the target upper limit value; if the energy storage system is charging at the high end for the first time, the subsystems are sequentially charged in a controllable manner, and when the first... j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

[0027] Preferably, each subsystem further includes a soft-start resistor and a switch, with the negative terminal of each energy storage medium connected to the negative output terminal of the corresponding power electronic converter; the positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch, and the other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal of the power electronic converter.

[0028] In the low-end charging module, if the energy storage system starts charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging start threshold, the subsystem is ready for polling charging. The switches of all subsystems are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging. The energy storage system is in polling charging state. Attached Figure Description

[0029] Figure 1 This is a topology diagram of the energy storage system applied to the AIDC intelligent computing center scenario of the present invention;

[0030] Figure 2 This is a diagram defining the threshold for the low-segment charging stage of the present invention;

[0031] Figure 3 This is a diagram defining the threshold for the high-end charging stage of the present invention.

[0032] Figure 4 This is a connection diagram of the converter of the present invention;

[0033] Figure 5 This is the equivalent model of the energy storage medium of the present invention. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0035] This specification presents an embodiment of an energy storage system control method applied to AIDC (AI Data Center) intelligent computing center scenarios, such as... Figure 1 , Figure 2 as well as Figure 3 As shown, it includes the following steps:

[0036] Connection steps: The power grid is connected to the DC bus through a solid-state transformer, and the solid-state transformer converts the AC power of the power grid into DC power; the energy storage system and data center load are connected to the DC bus; the energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter, and the energy storage medium is connected in parallel to the DC bus through the corresponding power electronic converter; the subsystem realizes the bidirectional flow of energy in the energy storage medium through the power electronic converter.

[0037] like Figure 5 As shown, the energy storage medium can be equivalent to a series internal resistance R and open-circuit voltage U0 model. During the charging process, the actual voltage across the energy storage medium is U=U0+iR, and during the discharging process, the actual voltage across the medium is U=U0-iR.

[0038] Control Procedure: Through the coordinated action of low-end power replenishment and high-end regulation, the voltage or state of charge (SOC) at both ends of the energy storage medium in each subsystem is adjusted in real time to near the target value. The target value can be the charging completion threshold. The charging completion threshold is 1117V or 98% SOC. The charging completion threshold is the target voltage, which is generally the upper limit of the recommended voltage for the energy storage medium.

[0039] Low-end charging occurs when the energy storage system discharges to the end, triggering a relevant threshold and initiating charging. High-end regulation occurs after the energy storage system is fully charged, triggering a relevant threshold and initiating regulation; or after the energy storage system is fully charged, in standby or quiescent mode, due to self-discharge of the energy storage medium or the consumption of energy by the DC-side power supply, the energy storage medium voltage or SOC decreases, triggering a relevant threshold and initiating high-end regulation. dc The voltage across the energy storage medium is detected by a voltage sensor; the SOC assessment is mainly obtained by using the OCV-SOC curve (the curve showing the relationship between the battery's open-circuit voltage and SOC) or the ampere-hour integration method (current integration).

[0040] Energy storage system topology for AIDC intelligent computing center scenarios, such as Figure 1 As shown, the system consists of a solid-state transformer (SST), an energy storage system, and a data center load. The SST converts medium-voltage AC power into low-voltage DC power; the energy storage system and the data center load are connected to the DC bus. When the data center load power P... 负载 >Grid power P 电网 The energy storage system discharges, for example, the energy storage system discharges with the absolute value of the power difference; when the load power P 负载 <Grid power P 电网 The energy storage system uses a power difference ΔP=P 电网 -P 负载 Charge.

[0041] The energy storage system consists of n energy storage subsystems connected in parallel to the DC bus. The subsystems achieve bidirectional energy flow through the energy storage medium via power electronic converters; resistor R is used for current-limited charging of the energy storage medium. Currently, the SST power ratings applied to AIDC are all in the MW range. If 314Ah cells are used, the highest operating voltage of a 104-cell liquid-cooled PACK (battery pack) is 3.6V * 104 * 3 (3 PACKs in series per cluster) = 1123V, and the maximum power of a single cluster is 1123 * 157A (0.5C charge / discharge) = 176kW. To meet load requirements, a subsystem consisting of multiple battery clusters and converters is needed.

[0042] If 314Ah cells are used, the cell operating voltage range is 3.2-3.6V. The highest operating voltage of a 104-cell liquid-cooled PACK is 3.6V * 104 * 3 (3 PACKs in series per cluster) = 1123V, and the lowest operating voltage is 3.2 * 104 * 3 = 998.4V. If the DC bus voltage is less than 998V, such as 800V or lower, the converter is a BOOST boost DC-DC converter (DC-DC converter); if the DC bus voltage is greater than 998V, such as 1500V, the converter is a BUCK buck DC-DC converter.

[0043] definition DC bus voltage For the first i Voltage across the energy storage medium of each subsystem Let the remaining charge of the energy storage medium in the i-th subsystem be . For the first j Voltage across the energy storage medium of each subsystem Let Rn be the remaining charge of the energy storage medium in the j-th subsystem. Let n be the n-th subsystem of the energy storage system, Rn be the n-th soft-start resistor, and KMn be the n-th switch.

[0044] In one embodiment, the control steps include the following steps:

[0045] Low-end charging steps: When the energy storage system is in polling charging state and is controlling the charging of subsystems sequentially, when the first... i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; when the voltage across the energy storage medium of each subsystem... If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging stops; each subsystem then sequentially begins polling charging until it reaches the target upper limit. The low-end charging cutoff threshold is, for example, 1040V. The target upper limit can be the upper limit threshold for charging completion.

[0046] The upper limit threshold for charging completion is, for example, 1123V or 100% SOC. Due to the equivalent internal resistance R of the energy storage medium, current flows through the voltage divider iR during charging. When the cluster voltage reaches the charging completion threshold and charging stops, the cluster open-circuit voltage will drop back to iR. Therefore, the upper limit threshold for charging completion should be greater than or equal to the charging completion threshold + iR to ensure that the cluster open-circuit voltage is greater than or equal to the charging completion threshold after charging stops.

[0047] High-end charging steps: When the voltage across the energy storage medium of each subsystem... When all values ​​are greater than or equal to the low-end charging cutoff threshold, and the subsystems are sequentially charged to the target upper limit, the energy storage system enters high-end charging, sequentially and controllably charging the subsystems until the target upper limit is reached. j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

[0048] In one embodiment, such as Figure 4As shown, in the connection step, each subsystem further includes a soft-start resistor and a switch. The negative terminal of each energy storage medium is connected to the negative output terminal (output terminal-) of the corresponding power electronic converter; the positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch, and the other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal (output terminal+) of the power electronic converter; the positive input terminal (input terminal+) of the power electronic converter is connected to the positive terminal of the DC bus, and the negative input terminal (input terminal-) of the power electronic converter is connected to the negative terminal of the DC bus.

[0049] In the low-end charging step, if the energy storage system is starting charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging activation threshold, the subsystem is ready for polling charging. All subsystem switches are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging mode, placing the energy storage system in polling charging state. The polling charging activation threshold is, for example, 1020V.

[0050] If there is a voltage difference between the two ends of the soft-start resistor (the voltage across the energy storage medium and the voltage across the DC side of the converter), such as >10V, the voltage difference between these two voltages should first be reduced to the required range, such as <10V, through the soft-start resistor.

[0051] A supporting capacitor C is connected in parallel across the DC side of the converter, forming an RC circuit with the soft-start resistor R1. The value of R1 can be approximated using the following formula:

[0052]

[0053] in, U c To support the capacitor voltage, U s The voltage across the energy storage medium. C To support the capacitance value, R1 The value of the soft-start resistor is t, and t is the design time for the differential pressure to reach the required range, which is usually in the range of seconds.

[0054] The subsystem controller and energy storage management system (such as the battery management system) draw power from the energy storage medium, consuming power P. When the subsystem terminal voltage reaches the discharge cutoff threshold, the subsystem's standby time is t4. During this process, the energy supplied by the energy storage medium is... Then, the polling charging start threshold is obtained based on the OCV curve of the energy storage medium (the curve showing the relationship between open-circuit voltage (OCV) and state of charge (SOC)). When the subsystem voltage drops to the polling charging start threshold, the subsystem standby time should be ≥t4.

[0055] In one embodiment, during the low-end charging step, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem is... When it falls from a high point, when the first j Voltage across the energy storage medium of the sleeve system ≤Discharge cutoff threshold and >Low-end fast charging threshold, only for the first j The casing system is charging when the first j Voltage across the energy storage medium of the sleeve system When the low-end charging threshold is reached, charging of the j-th subsystem is stopped; when the low-end charging threshold is reached, charging of the j-th subsystem is stopped. j Voltage across the energy storage medium of the sleeve system ≤Low-end fast charging threshold, the j-th subsystem is charging, when the th j Voltage across the energy storage medium of the sleeve system If the low-end charging threshold is reached, charging stops, and simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the threshold. When the low-end charging threshold is reached or exceeded, low-end polling charging will stop. The discharge cutoff threshold is, for example, 1035V. The low-end fast charging threshold is, for example, 1030V.

[0056] The discharge cutoff threshold is the system target voltage, typically 1.1 times the minimum operating range of the converter's DC side voltage plus a margin. Due to the equivalent internal resistance R of the energy storage medium, current flows through the voltage divider iR during charging. When the cluster voltage reaches the discharge cutoff threshold and charging stops, the cluster open-circuit voltage will drop back to iR. Therefore, the low-side charging cutoff threshold should be greater than or equal to the discharge cutoff threshold + iR to ensure that the cluster open-circuit voltage is greater than or equal to the discharge cutoff threshold after charging stops.

[0057] The subsystem controller and energy storage management system (such as the battery management system) draw power from the energy storage medium, consuming power P. When the subsystem terminal voltage reaches the discharge cutoff threshold, the subsystem's standby time is t3. During this process, the energy supplied by the energy storage medium is... Then, based on the OCV curve (the curve showing the relationship between open-circuit voltage (OCV) and state of charge (SOC)) of the energy storage medium, the low-end fast charging threshold is obtained. When the subsystem voltage drops to the low-end fast charging threshold, the subsystem standby time should be ≥t3.

[0058] The energy storage system switches to standby mode or polls for charging status.

[0059] In one embodiment, during the low-end charging step, if the energy storage system is in a discharging state, the voltage across the energy storage medium of the subsystem is... When it falls from a high point, when the first j Voltage across the energy storage medium of the sleeve system When the discharge cutoff threshold is ≤, the energy storage system stops discharging and switches to standby mode or polling charging mode.

[0060] In one embodiment, during the high-end charging step, the voltage across the energy storage medium of each subsystem is... After equalization charging reaches the upper limit threshold, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem... Or the remaining power of the energy storage medium SOC It fell from a high level.

[0061] When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end energy replenishment threshold, only the j-th subsystem is charged, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium When the charging completion threshold is reached, charging will stop; the high-end charging threshold is, for example, 1113V or 95% SOC.

[0062] The subsystem controller and energy storage management system (such as the battery management system) draw power from the energy storage medium, consuming power P. After the subsystem terminal voltage reaches the charging completion threshold, the subsystem idles for a period t1. During this process, the energy supplied by the energy storage medium is... Then, the high-end energy replenishment threshold is obtained based on the OCV curve (the curve showing the relationship between open-circuit voltage (OCV) and state of charge (SOC)) of the energy storage medium. When the subsystem voltage drops to the high-end energy replenishment threshold, the subsystem standby time should be ≥t1.

[0063] When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end fast charging threshold, the j-th subsystem is charging, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium Once the charging completion threshold is reached, charging stops; simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the maximum value. Alternatively, if the remaining SOC (State of Charge) of the energy storage medium is greater than or equal to the upper limit threshold for completion of charging, polling for charging will stop. High-end fast charging thresholds are, for example, 1107V or 93% SOC.

[0064] The subsystem controller and energy storage management system (such as the battery management system) draw power from the energy storage medium, consuming power P. After the subsystem terminal voltage reaches the charging completion threshold, the subsystem's standby time is t2. During this process, the energy supplied by the energy storage medium is... Then, the high-end fast charging threshold is obtained based on the OCV curve (the curve showing the relationship between open-circuit voltage (OCV) and state of charge (SOC)) of the energy storage medium. When the subsystem voltage drops to the high-end fast charging threshold, the subsystem standby time should be ≥t2.

[0065] The system enters standby mode.

[0066] In one embodiment, when the voltage across the energy storage medium of each subsystem... Alternatively, after the remaining state of charge (SOC) of the energy storage medium reaches the upper limit threshold for completion of charging, if the system is in a discharging state, the subsystem... Falling from a high point: When the j-th subsystem When the discharge threshold is ≤, the system stops discharging and begins the low-end charging process.

[0067] This invention also provides an energy storage control system for intelligent computing center scenarios, including a power grid, a solid-state transformer, a DC bus, an energy storage system, a data center load, and a control module; The power grid is connected to the DC bus via a solid-state transformer, which converts the AC power of the grid into DC power. The energy storage system and data center loads are connected to the DC bus. The energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter. The energy storage medium is connected in parallel to the DC bus through the corresponding power electronic converter. The subsystems achieve bidirectional energy flow of the energy storage medium through the power electronic converter.

[0068] The control module uses the combined action of low-end power replenishment and high-end regulation to control the voltage or state of charge of the energy storage medium at both ends of each subsystem in real time.

[0069] In one embodiment, the control module includes the following modules:

[0070] Low-end charging module: The energy storage system uses a polling charging status to controllably charge the subsystems sequentially. When the charging status is polled, the subsystem is charged in turn. i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; when the voltage across the energy storage medium of each subsystem... If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging will stop; each subsystem will then sequentially begin polling charging until the target upper limit value is reached. High-end charging module: When the voltage across the energy storage medium of each subsystem If all values ​​are greater than or equal to the low-end energy replenishment cutoff threshold, the subsystems will sequentially begin polling and charging until the target upper limit is reached; if the energy storage system is undergoing its first high-end charging, the subsystems will be charged in a controlled manner sequentially, until the first subsystem is charged. j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

[0071] In one embodiment, in the connection module, each subsystem further includes a soft-start resistor and a switch, the negative terminal of each energy storage medium is connected to the negative output terminal of the corresponding power electronic converter; the positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch, and the other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal of the power electronic converter.

[0072] In the low-end charging module, if the energy storage system starts charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging start threshold, the subsystem is ready for polling charging. The switches of all subsystems are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging. The energy storage system is in polling charging state.

[0073] This invention employs a control strategy that combines independent charging of a single subsystem with polling charging of multiple subsystems. Through the synergistic effect of low-end replenishment and high-end regulation, the terminal voltage or state of charge (SOC) of the energy storage medium of each subsystem is controlled in real time to be near the target value, i.e. near the charging completion threshold, thereby effectively ensuring the overall consistency of the energy state when multiple subsystems are running in parallel.

[0074] The energy storage system charging and discharging control method is divided into two stages: the low-end charging stage and the high-end charging stage.

[0075] During the low-end charging stage, such as Figure 2 As shown.

[0076] 1) The system starts charging for the first time.

[0077] ① Disconnect all subsystems KM. The DC bus charges all energy storage subsystems through a power electronic converter and a soft-start resistor R. The voltage across the energy storage medium of the subsystem... Ascend. When all subsystems When the polling charging start threshold is greater than or equal to the threshold value, the subsystem is ready for polling charging.

[0078] ②When all subsystems When the threshold for polling charging is ≥<, all subsystem KMs are closed, the soft-start resistor is bypassed, and polling charging at the low end of the subsystem is initiated.

[0079] ③ Charge the first subsystem when If the low-end power replenishment cutoff threshold is reached, charging of the first subsystem will be stopped.

[0080] Then charge the second subsystem, when If the low-end charging threshold is ≥<, stop charging the second subsystem;

[0081] The remaining subsystems are charged in a controlled manner in sequence, when If the low-end energy replenishment cutoff threshold is greater than or equal to the threshold value, stop charging the i-th subsystem.

[0082] ④ All subsystems If the low-end charging threshold is ≥<low-end charging cutoff threshold>, stop low-end polling charging.

[0083] ⑤ The system will sequentially start polling and charging until the target upper limit is reached.

[0084] 2) The system is in standby mode, and the subsystem voltage is... It fell from a high level.

[0085] ① When the j-th subsystem ≤<discharge cutoff threshold>, only the j-th subsystem is charged, when If the low-end charging cutoff threshold is ≥<, charging will stop.

[0086] ②When the j-th subsystem ≤<low-end fast charging threshold>, the j-th subsystem is charging, when Charge will stop if the low-end charging threshold is ≥<.

[0087] Simultaneously, the charging of all subsystems except the j-th subsystem begins in a round-robin fashion, until all subsystems are charged. If the low-end charging threshold is ≥<low-end charging cutoff threshold>, stop low-end polling charging.

[0088] ③The system switches to standby mode.

[0089] ④ If the system switches to charging mode, the system executes steps ③-⑤ of 1) and sequentially starts polling to charge to the target upper limit value, i.e., the upper limit threshold for charging completion.

[0090] 3) The system is in a discharging state, and the subsystem voltage is... It fell from a high level.

[0091] ① When the j-th subsystem If the discharge threshold is less than or equal to the discharge cutoff threshold, the system stops discharging.

[0092] ②If the system is in standby mode, the system executes steps ①-③ of 2).

[0093] ③If the system switches to charging mode, the system executes steps ③-⑤ of 1).

[0094] In the high-end charging stage, such as Figure 3 As shown.

[0095] When all subsystems If the low-end energy replenishment cutoff threshold is reached, the subsystem will sequentially start polling and charging until the target upper limit voltage is reached, which is the upper limit threshold for charging completion.

[0096] 1) The system's first high-end charging.

[0097] ① For the first subsystem, when or If the charging completion threshold is greater than or equal to the maximum threshold value, stop charging the first subsystem.

[0098] Controllable charging of the second subsystem, when or If the charging completion threshold is greater than or equal to the upper limit, stop charging the second subsystem.

[0099] The remaining subsystems are charged in a controlled manner in sequence, when or If the charging completion threshold is greater than or equal to the upper limit threshold, stop charging the i-th subsystem.

[0100] ②All subsystems If SOC is greater than or equal to the upper limit threshold for charging completion, stop polling for charging.

[0101] ③The system is in standby or discharging state.

[0102] 2) After all subsystems have charged to the <charging completion upper limit threshold>, if the system state is in standby mode, Or the SOC may fall from a high level:

[0103] ① When the j-th subsystem or ≤<high-end energy replenishment threshold>, only the j-th subsystem is charged, when or If the charging completion threshold is greater than or equal to the maximum charging threshold, charging will stop.

[0104] ②When the j-th subsystem or ≤<high-end fast charging threshold>, the j-th subsystem is charging, when or If the charging completion threshold is ≥<the upper limit threshold>, charging will stop.

[0105] Simultaneously, sequential polling and charging are performed on all subsystems except the j-th subsystem, until all subsystems are charged. If SOC is greater than or equal to the upper limit threshold for charging completion, stop polling for charging.

[0106] ③The system enters standby mode.

[0107] 3) All subsystems Alternatively, if the system is in a discharge state after the SOC has been charged to the <charging completion upper limit threshold>, the subsystem... Falling from a high:

[0108] ① When the j-th subsystem If the discharge threshold is less than or equal to the discharge cutoff threshold, the system stops discharging.

[0109] ②The system begins to enter the low-end charging phase.

[0110] In one embodiment, the OCV curve can be obtained by requesting curve data from the manufacturer and consulting a table for lithium batteries; for overcapacity batteries, the formula 0.5*C*U^ can be used. 2 To obtain.

[0111] The 11000F lithium supercapacitor cell has a voltage operating range of 0-4V, a rated operating current of 100A, and an equivalent DC internal resistance of 0.53mΩ. The lithium supercapacitor cluster is configured as a 1P288S, with a cluster voltage operating range of 0-1152V, an equivalent DC internal resistance of 152.64mΩ, and a cluster capacitance of 11000F / 288 = 38.19F.

[0112] The total power consumption of the inverter controller and lithium supercapacitor management system is 150W.

[0113] I. In the high-end charging stage:

[0114] 1. Charging completion threshold: Considering lifespan, lithium supercapacitor manufacturers generally recommend using a single cell voltage of 3.8V and a cluster voltage of 1094.4V. The charging completion threshold is set at 1094.4V.

[0115] 2. Upper limit threshold for charging completion: When the lithium supercapacitor is charged at the rated current of 100A, the voltage difference caused by the equivalent internal resistance is 152.64mΩ*100A=15.3V. The upper limit threshold for charging completion is set to 1094.4+15.3=1109.7V.

[0116] 3. High-end charging threshold: Standby time 2 hours, total power consumption of inverter controller + lithium supercapacitor management system 150W, energy consumption 1.08MJ. The lithium supercapacitor voltage drops from the charging completion threshold of 1094.4V to 1.08MJ, 1.08MJ = 0.5 * 38.19F * (1094.4^ 2 -x^ 2 ), and we get x = 1068.2V. The high-end power replenishment threshold is set to 1068.2V.

[0117] 4. High-end fast charging threshold: Standby time 3 hours, total power consumption of inverter controller + lithium supercapacitor management system 150W, energy consumption 1.62MJ. The lithium supercapacitor voltage drops from the charging completion threshold of 1094.4V to 1.62MJ, 1.62MJ = 0.5 * 38.19F * (1094.4^ 2 -x^ 2 ), and we get x = 1054.9V. The high-end fast charging threshold is set to 1054.9V.

[0118] II. During the low-end charging phase:

[0119] 1. Discharge cutoff threshold: The DC side voltage of a certain converter operates in the range of 800-1200V. Considering the margin, the discharge cutoff threshold can be set to 830V.

[0120] 2. The settings for the three values—low-end charging cutoff threshold, low-end fast charging threshold, and polling charging activation threshold—can refer to the method for obtaining the high-end threshold.

[0121] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An energy storage control method applied to intelligent computing center scenarios, characterized in that, Includes the following steps: Connection steps: The power grid is connected to the DC bus via a solid-state transformer, which converts the AC power from the grid to DC power. The energy storage system and data center loads are connected to the DC bus. The energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter. The energy storage medium is connected in parallel to the DC bus via a corresponding power electronic converter. The subsystems achieve bidirectional energy flow through the energy storage medium via the power electronic converter. Control steps: Through the synergistic effect of low-end power replenishment and high-end regulation, the voltage or state of charge of the energy storage medium at both ends of each subsystem is regulated in real time.

2. The energy storage control method for intelligent computing center scenarios according to claim 1, characterized in that, The control steps include the following: Low-end charging steps: The energy storage system polls the charging status, sequentially and controllably charging the subsystems. When the first subsystem... i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; When the voltage across the energy storage medium of each subsystem If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging will stop; each subsystem will then sequentially begin polling charging until the target upper limit value is reached. High-end charging steps: When the voltage across the energy storage medium of each subsystem... All values ​​are greater than or equal to the low-end energy replenishment cutoff threshold. The subsystems will sequentially poll and charge until the target upper limit value is reached. If the energy storage system enters high-end charging, the subsystems will be charged in a controlled manner sequentially. When the first... j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

3. The energy storage system control method for intelligent computing center scenarios according to claim 2, characterized in that, In the connection step, each subsystem also includes a soft-start resistor and a switch. The negative terminal of each energy storage medium is connected to the negative output terminal of the corresponding power electronic converter. The positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch. The other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal of the power electronic converter. In the low-end charging step, if the energy storage system is starting charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging start threshold, the subsystem is ready for polling charging. The switches of all subsystems are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging. The energy storage system is in polling charging state.

4. The energy storage control method for intelligent computing center scenarios according to claim 2, characterized in that, In the low-end charging step, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem is... From a high point, when the first j Voltage across the energy storage medium of the sleeve system ≤ Discharge cutoff threshold, only the j-th subsystem is charged, when the j-th subsystem is charged. j Voltage across the energy storage medium of the sleeve system When the low-end charging threshold is reached, charging of the j-th subsystem is stopped; when the low-end charging threshold is reached, charging of the j-th subsystem is stopped. j Voltage across the energy storage medium of the sleeve system ≤Low-end fast charging threshold, the j-th subsystem is charging, when the th j Voltage across the energy storage medium of the sleeve system If the low-end charging threshold is reached, charging stops, and simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the threshold. If the low-end charging threshold is reached or exceeded, stop low-end polling charging. The energy storage system switches to standby mode or polls for charging status.

5. The energy storage control method for intelligent computing center scenarios according to claim 4, characterized in that, In the low-end charging step, if the energy storage system is in a discharging state, the voltage across the energy storage medium of the subsystem is... From a high point, when the first j Voltage across the energy storage medium of the sleeve system When the discharge cutoff threshold is ≤, the energy storage system stops discharging and switches to standby mode or polling charging mode.

6. The energy storage control method for intelligent computing center scenarios according to claim 2, characterized in that, In the high-end charging step, the voltage across the energy storage medium of each subsystem is... After equalization charging reaches the upper limit threshold, if the energy storage system is in standby mode, the voltage across the energy storage medium of the subsystem... Or the remaining power of the energy storage medium SOC Falling from a high: When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end energy replenishment threshold, only the j-th subsystem is charged, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium When the charging completion threshold is reached, charging will stop. When the voltage across the energy storage medium of the j-th subsystem Or the remaining power of the energy storage medium ≤High-end fast charging threshold, the j-th subsystem is charging, when the voltage across the energy storage medium of the j-th subsystem is... Or the remaining power of the energy storage medium Once the charging completion threshold is reached, charging stops; simultaneously, sequential polling charging of the remaining subsystems begins until the voltage across the energy storage medium of each subsystem reaches the maximum value. Or, if the remaining SOC of the energy storage medium is greater than or equal to the upper limit threshold for charging completion, stop polling for charging; The system enters standby mode.

7. The energy storage control method for intelligent computing center scenarios according to claim 2, characterized in that, When the voltage across the energy storage medium of each subsystem Alternatively, after the remaining state of charge (SOC) of the energy storage medium reaches the upper limit threshold for completion of charging, if the system is in a discharging state, the subsystem... Falling from a high point: When the j-th subsystem When the discharge threshold is ≤, the system stops discharging and begins the low-end charging process.

8. An energy storage control system for intelligent computing center scenarios, characterized in that, This includes power grids, solid-state transformers, DC buses, energy storage systems, data center loads, and control modules; The power grid is connected to the DC bus via a solid-state transformer, which converts the AC power of the grid into DC power. The energy storage system and data center loads are connected to the DC bus. The energy storage system includes multiple subsystems, each of which includes an energy storage medium and a power electronic converter. The energy storage medium is connected in parallel to the DC bus through the corresponding power electronic converter. The subsystems achieve bidirectional energy flow of the energy storage medium through the power electronic converter. The control module uses the combined action of low-end power replenishment and high-end regulation to control the voltage or state of charge of the energy storage medium at both ends of each subsystem in real time.

9. The energy storage control system for intelligent computing center scenarios according to claim 8, characterized in that, The control module includes the following modules: Low-end charging module: The energy storage system uses a polling charging status to controllably charge the subsystems sequentially. When the charging status is polled, the subsystem is charged in turn. i Voltage across the energy storage medium of each subsystem ≥Low-end power supply cutoff threshold, stop supplying power to the first i Each subsystem is charged; When the voltage across the energy storage medium of each subsystem If all values ​​are greater than or equal to the low-end charging cutoff threshold, low-end polling charging will stop; each subsystem will then sequentially begin polling charging until the target upper limit value is reached. High-end charging module: When the voltage across the energy storage medium of each subsystem All values ​​are ≥ the low-end energy replenishment cutoff threshold, and the subsystems are sequentially polled and charged to the target upper limit value; if the energy storage system is charging at the high end for the first time, the subsystems are sequentially charged in a controllable manner, and when the first... j Voltage across the energy storage medium of the sleeve system Or the j Remaining power of the energy storage medium in the subsystem ≥Charging completion upper limit threshold, stop the first charge. j Subsystem charging; voltage across the energy storage medium of each subsystem Alternatively, if the remaining charge (SOC) of the energy storage medium in the subsystem is greater than or equal to the upper limit threshold for charging completion, polling for charging will stop.

10. The energy storage system control system applied to intelligent computing center scenarios according to claim 9, characterized in that, Each subsystem also includes a soft-start resistor and a switch. The negative terminal of each energy storage medium is connected to the negative output terminal of the corresponding power electronic converter. The positive terminal of each energy storage medium is connected to one end of the corresponding soft-start resistor and one end of the switch. The other end of the soft-start resistor and the other end of the switch are connected to the positive output terminal of the power electronic converter. In the low-end charging module, if the energy storage system starts charging for the first time, the switches of each subsystem are disconnected. The DC bus charges each subsystem through a power electronic converter and a corresponding soft-start resistor. The soft-start resistor is used for current-limited charging of the energy storage medium. The voltage across the energy storage medium of the subsystem is... Rise; when the voltage across the energy storage medium of each subsystem increases. When all values ​​are greater than or equal to the polling charging start threshold, the subsystem is ready for polling charging. The switches of all subsystems are closed, the soft-start resistor is bypassed, and the subsystem enters low-end polling charging. The energy storage system is in polling charging state.

Images