energy storage device

Abstract

The present disclosure provides a kind of energy storage device, it is related to energy storage power supply technical field, specifically related to uninterrupted power supply technology field of data center.The energy storage device includes battery module, control system and energy storage bus: battery module is connected on the output bus of data center by energy storage bus, for obtaining electric energy from data center and providing electric energy to the load of data center for charging;Control system is connected battery module and energy storage bus, for controlling battery module charging and discharging.

Description

Technical Field

[0001] This disclosure relates to the field of energy storage power supply technology, specifically to the field of uninterruptible power supply technology for data centers. Background Technology

[0002] Data centers are the core areas for information integration, typically hosting critical storage or computing resources and requiring a reliable power supply. Typically, data center architectures are equipped with HVDC (High-Voltage Direct Current) and lead-acid batteries as backup power for data center servers, providing uninterrupted power to the load in the event of mains power failures.

[0003] Lead-acid batteries have a long history of use and relatively inert chemical properties, making them considered relatively safe by the industry. Therefore, they are generally placed inside data center buildings. However, lead-acid batteries have a short cycle life and are not suitable for energy storage applications. Summary of the Invention

[0004] This disclosure provides an energy storage device, including a battery module, a control system, and an energy storage bus: the battery module is connected to the output bus of a data center via the energy storage bus, and is used to obtain power from the data center for charging and to provide power to the load of the data center; the control system is connected to the battery module and the energy storage bus, and is used to control the charging and discharging of the battery module.

[0005] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0006] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0007] Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the energy storage device according to the present disclosure;

[0008] Figure 2 This is a circuit structure schematic diagram of another embodiment of the energy storage device according to the present disclosure;

[0009] Figure 3 This is a circuit diagram of another embodiment of the energy storage device according to the present disclosure;

[0010] Figure 4 This is an architecture diagram of a data center connected to energy storage devices;

[0011] Figure 5 This is a schematic diagram of the power supply circuit of a data center. Detailed Implementation

[0012] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0013] With the introduction of national dual-carbon goals, the government encourages electricity-consuming enterprises to build energy storage systems. Data centers can utilize energy storage to both assist the power grid in peak shaving and valley filling—indirectly by participating in local user-side response and allowing users to adjust their own peak electricity consumption—and generate revenue from peak-valley price differences. Currently, peak-valley price differences are widening across regions, and configuring energy storage allows for direct revenue generation from these price differences.

[0014] This application proposes a new energy storage implementation method for data centers, which can ensure a simple data center architecture, low initial investment, high reliability, and is suitable for both new data centers and the renovation of existing data centers.

[0015] Figure 1 A schematic circuit diagram of an embodiment of an energy storage device according to the present disclosure is shown.

[0016] like Figure 1 As shown, the energy storage device 1 may include a battery module 101, a control system 102, and an energy storage bus 103.

[0017] The battery module 101 can be connected to the output bus of the data center via the energy storage bus 103 to obtain power from the data center for charging and to provide power to the load of the data center.

[0018] In some embodiments, the battery module 101 may include N lithium battery clusters. Nx lithium battery clusters may be power supply lithium battery clusters, and the remaining X lithium battery clusters may be redundant lithium battery clusters. N and X are positive integers, and N > X.

[0019] Typically, the output bus of a data center is an HVDC output bus, and each HVDC output bus can selectively connect to an energy storage device based on its own load characteristics, requirements, and other factors.

[0020] Typically, energy storage device 1 can consist of N lithium battery clusters. Energy storage device 1 can be placed outside the data center in a separate space, such as a building or shipping container. This physically isolates the energy storage device from the data center, preventing the impact of lithium battery fires on the data center. The size and footprint of the energy storage device can be flexibly configured based on available space in the campus, physical location, and HVDC requirements. Furthermore, the number of lithium battery clusters N is unlimited. This allows for flexible configuration and modification of energy storage devices, especially in data center renovations or situations with very limited space, making its application scenarios very broad.

[0021] Here, the number N of lithium battery clusters included in battery module 101 can be different from the number of connected HVDC output buses. N can be flexibly combined according to the energy storage capacity, the age of the batteries, etc., and supports the use of mixed new and old batteries, which has great application prospects in scenarios such as cascaded batteries. The configuration of N can be redundantly designed. Among them, NX lithium battery clusters meet the full rated power of the load. X is generally configured with a certain number of redundancies according to the system capacity. In this way, it can be ensured that when 1 to X lithium battery clusters among the N lithium battery clusters fail, the energy storage device 1 can still guarantee the full load power. For example, battery module 101 includes ten lithium battery clusters and is connected to two HVDC output buses of a data center. Among them, eight lithium battery clusters are power supply lithium battery clusters. When powered by battery module 101, these eight lithium battery clusters provide power to the load to meet the full rated power of the load. The other two lithium battery clusters are redundant lithium battery clusters. When two of the eight power supply lithium battery clusters fail, these two redundant lithium battery clusters become power supply lithium battery clusters. At this point, the eight lithium battery clusters still provide power to the load, ensuring full load power.

[0022] The control system 102 can be connected to the battery module 101 and the energy storage bus 103 to control the charging and discharging of the battery module 101.

[0023] In some embodiments, the control system 102 can control the battery module 101 to discharge during peak and / or flat electricity price periods and charge during off-peak periods, based on the set peak and off-peak electricity price periods, so as to obtain revenue through the peak-valley price difference.

[0024] Typically, the energy storage device 1 has a control system 102, which can control the energy storage device 1 and has no communication with other devices such as HVDC.

[0025] Continue to refer to Figure 2 The diagram shows a circuit structure schematic of yet another embodiment of the energy storage device according to the present disclosure.

[0026] like Figure 2As shown, the energy storage device 1 may include a battery module 101, a control system 102, an energy storage bus 103, a first DC / DC converter (Direct Current) 104, and a second DC / DC converter 105.

[0027] The battery module 101 can be connected to the output bus of the data center via the energy storage bus 103, for charging by obtaining power from the data center and for supplying power to the load of the data center. Furthermore, the battery module 101 may include N lithium battery clusters.

[0028] The control system 102 can be connected to the battery module 101, the energy storage bus 103 and the first DC / DC 104, and is used to control the charging and discharging of the battery module 101 and the first DC / DC 104.

[0029] In some embodiments, the control system 102 can collect the status information, total discharge current and total charging current of N lithium battery clusters, and control the charging current and discharging current of the second DC / DC 105 among the N second DC / DC 105s, as well as the output voltage of the first DC / DC 104, based on the status information, total discharge current and total charging current of the N lithium battery clusters.

[0030] Typically, the energy storage device 1 has a control system 102. The control system 102 controls the energy storage device 1 and the first DC / DC converter, but does not communicate with other devices such as the HVDC converter. The control system 102 is responsible for collecting lithium battery cluster information, collecting bus current, and controlling the second DC / DC converter. The lithium battery cluster has an internal battery management system responsible for collecting battery information and managing battery balancing. The battery management system transmits the status information and charging / discharging capabilities of the lithium battery cluster to the control system 102. The control system 102 can collect the total discharge current and charging current of the energy storage device 1 through battery sensors on the bus. Based on the total current and the status information of each lithium battery cluster, the control system 102 can control the charging and discharging currents of the second DC / DC converter 105 of each lithium battery cluster, as well as the output voltage of the first DC / DC converter 104 on the HVDC side.

[0031] The first DC / DC converter 104 can be connected between the energy storage bus 103 and the output bus to charge and discharge the battery module 101, and to isolate the battery module 101 in case of failure.

[0032] Typically, each HVDC can be connected to the energy storage device 1 via a first DC / DC 104. This first DC / DC 104 is an isolated DC / DC, meaning that any failure of the energy storage device 1 will not affect the original power supply system. Furthermore, the first DC / DC 104 is a bidirectional DC / DC, capable of both charging the energy storage device 1 and supplying power from the energy storage device 1 to the load. The first DC / DC 104 can convert the power from the energy storage device 1 into the HVDC output bus voltage, for example, converting a 1500V energy storage voltage into a 272V bus voltage.

[0033] The energy storage device 1 may further include N second DC / DC converters 105. Each lithium battery cluster corresponds to one of the second DC / DC converters 105, and the second DC / DC converters 105 are connected between the corresponding lithium battery cluster and the energy storage bus 103 to manage the charging and discharging of the lithium battery cluster.

[0034] Typically, each of the N lithium battery clusters within the energy storage device 1 is also equipped with a bidirectional, non-isolated second DC / DC converter 105, primarily used for charging and discharging management of each lithium battery cluster. The second DC / DC converter 105 can convert the varying battery voltage range into a stable voltage output, the specific voltage of which is set according to the actual application, such as 1500V.

[0035] Further reference Figure 3 , Figure 3 This is a circuit diagram of another embodiment of the energy storage device according to the present disclosure;

[0036] like Figure 3 As shown, the energy storage device 1 may include a battery module 101, a control system 102, an energy storage bus 103, a first DC / DC converter 104, a second DC / DC converter 105, a first switch 106, and a second switch 107.

[0037] The battery module 101 can be connected to the output bus of the data center via the energy storage bus 103, for charging by obtaining power from the data center and for supplying power to the load of the data center. Furthermore, the battery module 101 may include N lithium battery clusters.

[0038] The control system 102 can be connected to the battery module 101, the energy storage bus 103 and the first DC / DC 104, and is used to control the charging and discharging of the battery module 101 and the first DC / DC 104.

[0039] The first DC / DC converter 104 can be connected between the energy storage bus 103 and the output bus to charge and discharge the battery module 101, and to isolate the battery module 101 in case of failure.

[0040] The energy storage device 1 may further include N second DC / DC converters 105. The second DC / DC converters 105 of the N second DC / DC converters 105 are connected between the lithium battery clusters of the N lithium battery clusters and the energy storage bus 103, and are used to manage the charging and discharging of the lithium battery clusters.

[0041] The first switch 106 can be connected between the first DC / DC 104 and the output bus to control the connection and disconnection between the battery module 101 and the output bus.

[0042] Typically, the HVDC output bus can be connected to the first DC / DC 104 via the first switch 106 (usually a circuit breaker). The first switch 106 allows the HVDC output bus to be easily disconnected from the energy storage device 1 for maintenance and other operations.

[0043] The energy storage device 1 may also include N second switches 107, each of which corresponds to a second DC / DC converter. The second switches 107 can be connected between the corresponding second DC / DC converter 105 and the energy storage bus 103 for mutual decoupling between the N lithium battery clusters.

[0044] Typically, each lithium battery cluster is connected to the energy storage bus 103 via a second switch 107 (usually a circuit breaker) for power-off switching during maintenance or repair of each lithium battery cluster. The lithium battery clusters are decoupled from each other; that is, a failure or power outage of any one lithium battery cluster does not affect the operation of the other lithium battery clusters.

[0045] Further reference Figure 4 It shows the architecture diagram of a data center that connects to energy storage devices.

[0046] like Figure 4 As shown, the data center is supplied with two 10kV mains power sources (i.e., the first mains power and the second mains power). These two 10kV mains power sources are connected to two 10kV busbars (i.e., the first 10kV busbar and the second 10kV busbar), linked by a bus tie switch. Each 10kV busbar is connected to the same diesel generator. The 10kV busbar voltage is converted to 380V AC power (i.e., the first 380V busbar and the second 380V busbar) by transformers (i.e., the first 380V busbar and the second 380V busbar), and then converted to DC power (e.g., 270V) via a distributed HVDC output busbar to power the load. Under normal power conditions, each mains power source supplies 50% of the load. When one mains power source fails, the other supplies 100% of the load; when both mains power sources fail, the diesel generator starts and supplies 100% of the load. Since the diesel generator requires time to start, lead-acid batteries are connected to the HVDC output busbar as a backup power system. Power is supplied to the load after both mains power lines fail and before the diesel generator starts successfully.

[0047] However, lead-acid batteries have a short cycle life and cannot be used for energy storage applications, so an energy storage device is also connected to the HVDC output bus.

[0048] Each HVDC output bus can be selectively connected to an energy storage device based on its load characteristics and requirements. Each HVDC can be connected to the energy storage device via a DC / DC converter. This DC / DC converter is isolated, meaning that any failure of the energy storage device will not affect the original power supply system. Simultaneously, this DC / DC converter is bidirectional, capable of both charging the energy storage device and supplying power from the energy storage device to the load. The HVDC output bus can be connected to this DC / DC converter via a switch (usually a circuit breaker), which allows for easy disconnection between the HVDC bus and the energy storage device for maintenance and other operations. This DC / DC converter can convert the energy storage device's power supply to the HVDC bus voltage, for example, converting 1500V energy storage voltage to 272V bus voltage.

[0049] The energy storage device can consist of N lithium battery clusters. It can be placed outside the data center in a separate space, such as a building or shipping container. This physically isolates the lithium batteries from the data center, preventing the impact of fires or other hazards from the lithium batteries. The size and footprint of the energy storage device can be flexibly configured based on available space, physical location, and HVDC requirements within the campus, and the number of lithium battery clusters N is unlimited. This allows for flexible configuration and modification of energy storage devices, especially in data center renovations or situations with very limited space, making its application scenarios very broad. Furthermore, the number of lithium battery clusters N can differ from the number of connected HVDC output buses. N can be flexibly combined based on the energy storage capacity, battery age, etc., and supports the mixing of new and old batteries, showing great application potential in scenarios such as secondary batteries. The configuration of N can be redundantly designed, with N lithium battery clusters meeting the full rated power of the load, and X typically configured with a certain redundancy based on system capacity. This ensures that even if 1 to X of the N lithium battery clusters fail, the system can still guarantee the full load power.

[0050] Each of the N lithium battery clusters within the energy storage device is equipped with a bidirectional non-isolated DC / DC converter, primarily used for charging and discharging management of each cluster. The DC / DC converter transforms the varying battery voltage range into a stable output voltage, the specific voltage of which is set according to the actual application, such as 1500V. Each lithium battery cluster is connected to the energy storage bus via a switch (usually a circuit breaker) for power-off switching during maintenance or repair of each cluster. The lithium battery clusters are decoupled from each other, meaning that a fault or power outage in any one cluster does not affect the operation of the others.

[0051] The energy storage device has a control system that only controls the energy storage device and the DC / DC converter on the HVDC side, without communicating with other devices such as the HVDC converter. The control system is responsible for collecting information from the lithium battery clusters, collecting bus current, and controlling the DC / DC converter. Each lithium battery cluster has an internal battery management system (BMS) responsible for collecting battery information and managing battery balancing. The BMS transmits the status information and charging / discharging capabilities of the lithium battery clusters to the control system. The control system can collect the total discharge and charging current of the energy storage device through battery sensors on the bus. Based on the total current and the status information of each lithium battery cluster, the control system can control the charging and discharging currents of each lithium battery cluster's DC / DC converter, as well as the output voltage of the HVDC converter. Simultaneously, the control system can also set peak and off-peak times, allowing for discharge during peak and / or flat periods, and discharge during off-peak periods.

[0052] It should be noted that, Figure 4 The diagram in the middle is a simplified illustration. The number of devices configured at each level in the actual system will vary, and conventional switches directly configured at each level are not shown.

[0053] Further reference Figure 5 It shows a schematic diagram of the power supply circuit of the data center.

[0054] like Figure 5 As shown, the lead-acid batteries in the data center are connected to the output bus. When the energy storage device is in standby mode, the lead-acid batteries are float-charged, and the output bus provides power to the load. When the energy storage device is discharging, the lead-acid batteries are float-charged, and the energy storage device provides power to the load. When the energy storage device is charging, the charging current required by each of the N lithium battery clusters is calculated. Based on the charging current required by the N lithium battery clusters, the total charging current is calculated. The first DC / DC converter limits the charging based on the total charging current, and the control system distributes the current to the N second DC / DC converters based on the charging current required by the N lithium battery clusters. When the mains power fails, if the energy storage device has power, it discharges through the first DC / DC converter; if the energy storage device has no power, the lead-acid batteries discharge. When the energy storage device malfunctions, the first DC / DC converter disconnects.

[0055] Taking the connection of the HVDC output bus of two data centers to an energy storage device as an example, the HVDC output voltage is a constant 270V. Lead-acid batteries are directly connected to bus M1 and are in float charging mode during normal operation. That is, they are charged with a very small trickle charge, which can be considered as a non-charging and non-discharging state. The energy storage device consists of three lithium battery clusters. Each lithium battery cluster consists of 420 cells connected in series. The operating voltage of each cell is set to 2.5V to 3.5V, so the output voltage range of the lithium battery cluster is 1050V to 1470V. This is converted to a constant 1500V by a DC / DC converter (such as D1) on the lithium battery cluster side, meaning bus M2 is at a constant 1500V. The HVDC-side DC / DC converter (such as C1) converts the 1500V voltage to different output voltages, such as 268V and 272V.

[0056] In standby mode, the lead-acid battery is float-charged, with the HVDC output voltage at 270V. The energy storage device controls the voltage adjustment of C1 and C2 to 268V. At this time, since the HVDC output power is at its highest, the load is powered by the HVDC.

[0057] During energy storage discharge, the lead-acid battery remains in float charge, with an HVDC output voltage of 270V. The energy storage device controls the voltage of C1 and C2 to be adjusted to 272V. At this time, the lead-acid battery continues to float charge at 272V. Because the output voltage of the energy storage device is higher than the HVDC voltage, the energy storage device performs the discharge.

[0058] During energy storage charging, the energy storage device calculates the required charging current for each lithium battery cluster based on the current time period and the state of the lithium battery clusters, for example, A1, A2, and A3 respectively. At this time, the system assumes that C1 and C2 require a current of (A1+A2+A3) / 2 respectively, and simultaneously controls the charging circuits of C1 and C2 to be connected. If the load is small at this time, each HVDC can provide sufficient current. In this case, C1 and C2 are charged with current-limited current according to (A1+A2+A3) / 2 respectively. The control system then distributes the current to D1, D2, and D3 based on the obtained total current. If C1 cannot provide the maximum current, the HVDC on C1 will provide the maximum current it can (HVDC itself is controlled). At this time, the system controls C2 to request current limiting for the remaining current. If the load on C2 is also large, the HVDC on C2 will provide the maximum current it can (HVDC itself is controlled). At this point, after bus M1 receives the total current, the system continues to dynamically distribute the current according to the state of each lithium battery cluster to ensure that the charging state of each lithium battery cluster remains consistent and is fully charged as simultaneously as possible.

[0059] When the mains power fails, if the energy storage device still has power, it can discharge through C1 and C2. If the energy storage device has no power, the output voltage will gradually decrease, and the lead-acid battery will discharge.

[0060] When the energy storage fails, C1 and C2 disconnect, and since C1 and C2 are isolated devices, there is no circuit connection, so it has no impact on the original power supply system.

[0061] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An energy storage device, characterized in that, Includes battery modules, control systems, and energy storage buses: The battery module is connected to the output bus of the data center through the energy storage bus. It is used to obtain power from the data center for charging and to provide power to the load of the data center. The battery module includes N lithium battery clusters, of which Nx lithium battery clusters are power supply lithium battery clusters and the remaining X lithium battery clusters are redundant lithium battery clusters. N and X are positive integers, and N>X. The control system is connected to the battery module and the energy storage bus, and is used to control the charging and discharging of the battery module; The energy storage device also includes a first DC-to-DC power supply connected between the energy storage bus and the output bus, used for charging and discharging the battery module, and for isolating the battery module when the battery module fails. The energy storage device also includes N second DC / DC converters, with each lithium battery cluster corresponding to one of the second DC / DC converters. The second DC / DC converters are connected between the corresponding lithium battery cluster and the energy storage bus to manage the charging and discharging of the lithium battery cluster. The energy storage device includes N second switches, each corresponding to a second DC / DC converter, and the second switches are connected between the corresponding second DC / DC converter and the energy storage bus, for decoupling between the N lithium battery clusters.

2. The apparatus according to claim 1, characterized in that, The energy storage device also includes a first switch connected between the first DC / DC converter and the output bus, used to control the connection and disconnection between the battery module and the output bus.

3. The apparatus according to claim 1, characterized in that, The control system is also connected to the first DC / DC converter and is used to control the first DC / DC converter.

4. The apparatus according to claim 3, characterized in that, The control system collects the status information, total discharge current, and total charging current of the N lithium battery clusters, and controls the charging current and discharge current of the second DC / DC converter among the N second DC / DC converters, as well as the output voltage of the first DC / DC converter, based on the status information, total discharge current, and total charging current of the N lithium battery clusters.

5. The apparatus according to any one of claims 1-4, characterized in that, The control system controls the battery module to discharge during peak and / or flat electricity price periods and charge during off-peak periods, based on the set time intervals for peak and off-peak electricity price periods.

6. The apparatus according to any one of claims 1-4, characterized in that, The lithium battery clusters among the N lithium battery clusters are equipped with a battery management system, which is used to transmit the status information and charging / discharging capacity of the lithium battery clusters to the control system.

7. The apparatus according to claim 1, characterized in that, The lead-acid battery of the data center is connected to the output bus; When the energy storage device is in standby mode, the lead-acid battery is float charged, and the output bus provides power to the load. When the energy storage device discharges, the lead-acid battery is float charged, and the energy storage device provides electrical energy to the load. When the energy storage device is charging, the charging current required by the lithium battery clusters in the N lithium battery clusters is calculated, the total charging current is calculated based on the charging current required by the lithium battery clusters in the N lithium battery clusters, the first DC / DC converter limits the charging according to the total charging current, and the control system distributes the current of the second DC / DC converters in the N second DC / DC converters according to the charging current required by the lithium battery clusters in the N lithium battery clusters. When the mains power fails, if the energy storage device is powered, it discharges through the first DC / DC converter; if the energy storage device is de-powered, it discharges through the lead-acid battery. When the energy storage device fails, the first DC / DC converter is disconnected.

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