Power supply system and power supply control method

Abstract

The application provides a power supply system and a power supply control method, and belongs to the technical field of power electronics. The power supply system supplies power to an alternating current load by a DC / AC converter through an energy storage device in a first target period (for example, a power consumption peak period). In a second target period (for example, a power consumption flat period and a power consumption valley period), or when the residual power of the energy storage device is less than or equal to a threshold value, the alternating current load is supplied with power by a power grid. Compared with the mode that the alternating current load can only take power from the power grid, the above scheme effectively improves the flexibility of supplying power to the alternating current load. Moreover, by configuring the first target period as the power consumption peak period and configuring the second target period as the power consumption flat period and the power consumption valley period, the power grid load can be effectively balanced, the stability of the power grid can be improved, and the power consumption cost of the alternating current load in the power consumption peak period can be effectively reduced.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power supply system and power supply control method. Background Technology

[0002] The power supply system for communication equipment rooms and base stations typically includes energy storage devices and alternating current / direct current (AC / DC) converters. The AC terminal of the AC / DC converter is connected to the power grid, while the DC terminal is connected to the energy storage device via a DC bus. Furthermore, the AC terminal of the AC / DC converter is also connected to AC loads, such as air conditioning and lighting equipment. The DC bus is also connected to DC loads, such as baseband units (BBUs) and remote radio units (RRUs).

[0003] In the aforementioned power supply system, AC loads are powered by the power grid. An AC / DC converter is used to convert the AC power from the grid into DC power and output it to the DC bus to power the DC loads and charge the energy storage devices. When the power grid fails, the energy storage devices can discharge and power the DC loads. This power supply system offers limited flexibility. Summary of the Invention

[0004] This application provides a power supply system and a power supply control method, which can solve the technical problem of power supply flexibility in the power supply system.

[0005] In a first aspect, a power supply system is provided, comprising: an AC / DC converter, a DC / AC converter, a switching circuit, an energy storage device, and a controller. The AC terminal of the AC / DC converter is connected to the power grid, and the DC terminal is connected to the energy storage device. The DC terminal of the DC / AC converter is connected to the energy storage device, and the AC terminal is connected to both the power grid and an AC load. The controller is used to control the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load during a first target time period, and to enable the power grid to supply power to the AC load during a second target time period, or when the remaining charge of the energy storage device is less than or equal to a threshold. The first and second target time periods do not overlap.

[0006] The power supply system provided in this application enables energy storage devices to supply power to AC loads via DC / AC converters during a first target period (e.g., peak electricity consumption period). Furthermore, it enables the grid to supply power to the AC loads during a second target period (e.g., a consumption buffer period and an off-peak period), or when the remaining power of the energy storage devices is less than or equal to a threshold (for clarity, this threshold is referred to as the first threshold). Compared to methods where AC loads can only draw power from the grid, the solution provided in this application effectively improves the flexibility of supplying power to AC loads. Moreover, by configuring the first target period as a peak electricity consumption period and the second target period as a consumption buffer period and an off-peak period, it not only effectively balances the grid load and improves grid stability but also effectively reduces the electricity cost of the AC load during peak electricity consumption periods.

[0007] In one embodiment, the power supply system further includes a switching circuit. Both the AC terminal of the DC / AC converter and the AC load are used to connect to the power grid via the switching circuit. The controller is also configured to control the switching circuit to open during a first target time period and to control the switching circuit to close during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold (i.e., the first threshold).

[0008] By adding a switching circuit, the AC load can be disconnected from the grid during the first target time period, and the DC / AC converter can also be disconnected from the grid. In other words, the DC / AC converter can operate offline during the first target time period. Therefore, the DC / AC converter does not need to have grid-connection capabilities, reducing the performance requirements for the DC / AC converter. Furthermore, since the DC / AC converter does not feed power into the grid, there is no need to apply for grid connection with the grid company, avoiding the registration process for grid connection applications.

[0009] In one embodiment, the controller is further configured to: send a start command to the DC / AC converter during a first target time period to instruct the DC / AC converter to start; and send a shutdown command to the DC / AC converter during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold, to instruct the DC / AC converter to shut down.

[0010] When the AC load is powered by the grid, shutting down the DC / AC converter can prevent the AC output of the DC / AC converter from impacting the grid and the AC load, and can also prevent unnecessary power consumption waste caused by the DC / AC converter continuing to run.

[0011] In one embodiment, the DC / AC converter is configured to report an alarm signal to the controller if startup fails. The controller is also configured to supply power to the AC load from the grid based on the alarm signal. For example, the controller may control a switching circuit to close, and / or control the DC / AC converter to remain off, thereby allowing the grid to supply power to the AC load.

[0012] Understandably, in scenarios such as base stations or communication equipment rooms, the AC load is mainly air conditioning. Since air conditioners are motor-induced loads, their starting inrush current is large and varied. Therefore, the DC / AC converter bears this inrush current, which may lead to overcurrent protection during startup. In the solution provided in this application, the DC / AC converter can report an alarm signal to the controller when startup fails. The controller can then use this alarm signal to ensure the AC load continues to be powered by the grid, thus ensuring its normal operation.

[0013] In one embodiment, the controller is configured to, during a first target time period, if the remaining power of the energy storage device is greater than a threshold (i.e., a first threshold), control the DC / AC converter to convert the DC power of the energy storage device into AC power to supply AC load.

[0014] The aforementioned threshold (i.e., the first threshold) can refer to the minimum amount of electricity required for the energy storage device to be in a discharging state, and this first threshold can be determined based on the energy storage device's charge level when fully charged. It is understood that if the remaining charge of the energy storage device is less than or equal to this first threshold, it cannot effectively supply power to the AC load. To ensure the normal operation of the AC load, the controller can first detect the remaining charge of the energy storage device. Once it is determined that the remaining charge is greater than the first threshold, the controller then controls the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load. This ensures that the energy storage device can effectively supply power to the AC load, avoiding repeated switching of the AC load's power supply mode.

[0015] It is also understandable that, during the first target period, if the remaining power of the energy storage device is greater than the first threshold, the energy storage device can also supply power to the DC load. That is, during the first target period, and when the remaining power of the energy storage device is relatively large, the energy storage device can supply power to both DC and AC loads simultaneously.

[0016] In one embodiment, the controller is further configured to, upon detecting a power outage, control a DC / AC converter to convert the DC power from the energy storage device into AC power to supply the AC load. This ensures that the AC load can continue to operate even after a power outage.

[0017] For example, when a power outage is detected, the controller can, if it determines that the remaining power of the energy storage device is greater than a second threshold, control the DC / AC converter to convert the DC power from the energy storage device into AC power to supply AC loads. This second threshold can be greater than or equal to the first threshold mentioned above. Specifically, if the second threshold is greater than the first threshold, it indicates that after a power outage, when the remaining power of the energy storage device is greater than the second threshold, the energy storage device can supply power to both DC and AC loads simultaneously. If the remaining power of the energy storage device is greater than the first threshold but not greater than the second threshold, the energy storage device can stop supplying power to AC loads and only supply power to DC loads. That is, after a power outage, the energy storage device can prioritize supplying power to DC loads.

[0018] In one embodiment, the DC / AC converter is a bidirectional power converter, meaning it can convert both direct current (DC) and alternating current (AC). The controller is further configured to, during a third target time period, control the AC / DC converter to convert AC power from the grid to DC power to charge the energy storage device, and also control the DC / AC converter to convert AC power from the grid to DC power to charge the energy storage device. The first target time period and the third target time period do not overlap. Furthermore, the third target time period may partially overlap with the aforementioned second target time period.

[0019] For example, the third target period may include off-peak electricity demand. During the third target period (such as off-peak electricity demand), the power supply system charges the energy storage device through the power grid. On the one hand, this can achieve peak-shifting electricity consumption, effectively balance the grid load, and improve grid stability. On the other hand, it can effectively reduce the charging cost of the energy storage device, thereby reducing the electricity cost of subsequent DC and AC loads.

[0020] Secondly, a power supply control method is provided, applicable to a power supply system, such as the power supply system provided in the first aspect above. The power supply system includes: an AC / DC converter, a DC / AC converter, and an energy storage device. The AC terminal of the AC / DC converter is connected to the power grid, and the DC terminal of the AC / DC converter is connected to the energy storage device. The DC terminal of the DC / AC converter is connected to the energy storage device, and the AC terminal of the DC / AC converter is connected to both the power grid and an AC load. The method includes: during a first target time period, controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load; and during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold, causing the power grid to supply power to the AC load. The first target time period and the second target time period do not overlap.

[0021] In one embodiment, the power supply system further includes a switching circuit; both the AC terminal of the DC / AC converter and the AC load are used to connect to the power grid through the switching circuit. Furthermore, during a first target time period, the process of controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load includes: during the first target time period, controlling the switching circuit to open; during a second target time period, or when the remaining charge of the energy storage device is less than or equal to a threshold, the process of enabling the power grid to supply power to the AC load includes: during the second target time period, or when the remaining charge of the energy storage device is less than or equal to the threshold, controlling the switching circuit to close.

[0022] In one embodiment, during a first target time period, the process of controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply AC load includes: during the first target time period, sending a start command to the DC / AC converter to instruct the DC / AC converter to start; during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold, the process of enabling the grid to supply AC load includes: during the second target time period, or when the remaining power of the energy storage device is less than or equal to the threshold, sending a shutdown command to the DC / AC converter to instruct the DC / AC converter to shut down.

[0023] In one embodiment, the method further includes: if the DC / AC converter fails to start, then supplying power to the AC load from the grid. For example, if the DC / AC converter detects a startup failure after receiving a startup command, it can report an alarm signal to the controller in the power supply system. The controller can then control the closing of a switching circuit based on the alarm signal, and / or control the DC / AC converter to remain in a shutdown state so that the grid supplies power to the AC load.

[0024] In one embodiment, during a first target time period, the process of controlling the DC / AC converter to convert the DC power of the energy storage device into AC power to supply AC load includes: during the first target time period, if the remaining power of the energy storage device is greater than a threshold (i.e., a first threshold), then controlling the DC / AC converter to convert the DC power of the energy storage device into AC power to supply AC load.

[0025] In one embodiment, the method further includes: if a power grid outage is detected, controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load.

[0026] For example, the above steps may include: if a power outage is detected and the remaining power of the energy storage device is greater than a second threshold, then controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply AC loads. The second threshold may be greater than or equal to the first threshold described above.

[0027] In one embodiment, the DC / AC converter is a bidirectional power converter. Furthermore, the method further includes: during a third target time period, controlling the AC / DC converter to convert the AC power from the grid into DC power to charge the energy storage device, and controlling the DC / AC converter to convert the AC power from the grid into DC power to charge the energy storage device. The first target time period and the third target time period do not overlap.

[0028] In summary, this application provides a power supply system and a power supply control method. During a first target period (e.g., peak electricity consumption), the power supply system uses an energy storage device to supply power to the AC load via a DC / AC converter. Furthermore, during a second target period (e.g., a consumption buffer period and a low-consumption period), or when the remaining power in the energy storage device is less than or equal to a threshold, the power grid supplies power to the AC load. Compared to methods where AC loads can only draw power from the grid, the solution provided in this application effectively improves the flexibility of supplying power to AC loads. Moreover, by configuring the first target period as a peak electricity consumption period and the second target period as a consumption buffer period and a low-consumption period, not only can the grid load be effectively balanced and grid stability improved, but the electricity cost of AC loads during peak electricity consumption periods can also be effectively reduced. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a peak-valley electricity pricing scheme provided in an embodiment of this application;

[0030] Figure 2 These are schematic diagrams of the power supply system in some embodiments;

[0031] Figure 3 This is a schematic diagram of a power supply system provided in an embodiment of this application;

[0032] Figure 4 This is a schematic diagram of another power supply system provided in an embodiment of this application;

[0033] Figure 5 This is a schematic diagram of another power supply system provided in the embodiments of this application;

[0034] Figure 6 This is a flowchart of an AC staggered discharge method provided in an embodiment of this application;

[0035] Figure 7 This is another flowchart of AC staggered discharge provided in the embodiments of this application;

[0036] Figure 8 This is a flowchart of a power supply control method provided in an embodiment of this application. Detailed Implementation

[0037] The power supply system and power supply control method provided in the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0038] To alleviate peak-hour power supply pressure on the power grid, peak-valley pricing (also known as time-of-use pricing) is typically used to encourage electricity users to stagger their electricity consumption times, thereby balancing the grid load and improving grid stability. Peak-valley pricing refers to applying different electricity prices at different times of the day. Figure 1 This is a schematic diagram of a peak-valley electricity pricing scheme provided in an embodiment of this application. Figure 1 The horizontal axis represents time, specifically 24 hours in a day, and the vertical axis represents electricity price. (Reference) Figure 1 As can be seen, the peak-valley electricity pricing scheme divides electricity consumption periods into peak periods, lull periods, and off-peak periods. For example, the peak periods are from 8:00 to 11:00 and from 18:00 to 20:00 each day, during which higher electricity prices are applied. The off-peak period is from 22:00 to 6:00 the next day, during which lower electricity prices are applied. The remaining periods are lull periods, during which flat prices are applied. This effectively guides some of the load from peak periods to off-peak periods.

[0039] like Figure 2 As shown, the power supply system in some embodiments includes an AC / DC converter, a controller, and an energy storage device. In areas implementing peak-valley electricity pricing, for businesses or users, the controller can control the AC / DC converter to draw power from the grid and charge the energy storage device (i.e., energy storage battery) and supply power to DC loads during off-peak or low-demand periods. During peak periods, the energy storage device directly supplies power to the DC loads, thereby reducing or eliminating grid power consumption during peak hours. This not only improves grid load factor and equipment utilization but also allows for reduction of electricity costs and the acquisition of peak-shifting benefits by utilizing the peak-valley price difference.

[0040] However, the above solution only manages the power consumption of DC loads, meaning this peak-shaving power supply scheme only applies to DC loads, while AC loads are always powered by the grid, resulting in low flexibility. Furthermore, it's understandable that in scenarios like communication equipment room power supply and base station power supply, the air conditioning in these rooms or base stations is powered by AC. Since the equipment in the equipment room generates a large amount of heat, air conditioning is needed to maintain a suitable operating temperature to ensure stable operation and extend the lifespan of the equipment. Therefore, air conditioning accounts for a significant proportion of the total power consumption in the equipment room. For example, air conditioning accounts for approximately 50% of the total power consumption in the equipment room. Thus, AC loads such as air conditioners are among the main power-consuming devices in equipment rooms, accounting for a considerable proportion of energy consumption. If AC loads (such as air conditioners and lighting equipment) could participate in peak-shaving power supply along with DC loads, it could effectively improve the overall peak-shaving benefits in areas implementing peak-valley electricity pricing.

[0041] Figure 3 This is a schematic diagram of a power supply system provided in an embodiment of this application. This system can supply power to AC loads in different ways at different times, effectively improving power supply flexibility, grid load factor, and equipment utilization. Furthermore, in areas implementing peak-valley electricity pricing, this system can effectively increase the benefits of off-peak electricity consumption. Figure 3 As shown, the power supply system provided in this application embodiment includes: an AC / DC converter 10, a DC / AC converter 20, an energy storage device 30, and a controller 40.

[0042] In this design, the AC terminal of AC / DC converter 10 is connected to the power grid, and the DC terminal of AC / DC converter 10 is connected to energy storage device 30. The DC terminal of DC / AC converter 20 is connected to energy storage device 30, and the AC terminals of DC / AC converter 20 are used to connect to the power grid and AC loads respectively. For example, refer to... Figure 3 The power supply system also includes a DC busbar (also called a DC bus), to which the DC terminals of the AC / DC converter 10, the DC terminals of the DC / AC converter 20, and the energy storage device 30 are all connected. Here, AC load refers to a load powered by AC electricity, which may include air conditioning and / or lighting equipment, etc.

[0043] It is understood that the AC / DC converter 10 in the power supply system can be used to convert AC power from the power grid into DC power and output it to the DC bus. This AC / DC converter 10 can also be called an AC / DC rectifier or an AC / DC rectifier unit. The DC / AC converter 20 is used to convert DC power from the DC bus into AC power and output it, for example, to an AC load. This DC / AC converter 20 is also called a DC / AC inverter or a DC / AC inverter unit.

[0044] The controller 40 in this power supply system is used to control the DC / AC converter 20 to convert the DC power from the energy storage device 30 into AC power to supply AC loads during a first target time period, and to enable the power grid to supply AC loads during a second target time period, or when the remaining power of the energy storage device 30 is less than or equal to a threshold (for ease of distinction, this threshold is referred to as the first threshold). The first target time period and the second target time period do not overlap.

[0045] In this embodiment, the first target time period can refer to the time period during which the energy storage device 30 is preferentially used to supply power to the AC load, and the second target time period can refer to the time period during which the power grid is preferentially used to supply power to the AC load. Furthermore, both the first and second target time periods can be pre-configured time periods in the controller 40, and the ranges of both the first and second target time periods can be flexibly adjusted according to the needs of the application scenario.

[0046] For example, in areas implementing peak-valley electricity pricing, the first target period can be a period with higher electricity prices, and the second target period can be a period with lower electricity prices. For instance, the first target period could be the peak electricity consumption period. Alternatively, the first target period could include the peak electricity consumption period, meaning the first target period could be slightly larger than the peak electricity consumption period to ensure that AC loads are powered by the energy storage device 30 during the peak electricity consumption period. The second target period could include a period of reduced electricity consumption and a period of low electricity consumption.

[0047] It is understood that the remaining power of the energy storage device 30 can be characterized by its state of charge (SOC). The aforementioned first threshold can refer to the minimum amount of power required for the energy storage device 30 to be in a discharging state (i.e., the lower limit of the power required for discharging), and this first threshold can be determined based on the power of the energy storage device 30 in a fully charged state. For example, the first threshold can be equal to the product of the power of the energy storage device 30 in a fully charged state and a first proportionality coefficient, which can be a number greater than 0 and less than 1. For example, the first proportionality coefficient can be 0.2 or 0.25, etc.

[0048] It is also understandable that when the first target period is in effect, the energy storage device 30 supplies power to the AC load, which not only effectively balances the grid load and improves grid stability, but also effectively reduces the electricity cost of the AC load during peak consumption periods. When the second target period is in effect, the benefit of continuing to supply power to the AC load through the energy storage device 30 is lower. Therefore, when the controller 40 detects that the current time is in the second target period, it can enable the grid to supply power to the AC load. Alternatively, when the remaining power of the energy storage device 30 is not greater than the first threshold, the controller 40 can determine that the energy storage device 30 can no longer effectively supply power to the AC load. Therefore, the controller 40 can also enable the grid to supply power to the AC load, thereby ensuring that the AC load can operate normally.

[0049] In summary, the solution provided in this application can control the DC / AC converter to convert the DC power from the energy storage device into AC power to supply AC loads during the first target period (e.g., peak electricity consumption period) to ensure the normal operation of the AC loads. Furthermore, the power grid can supply AC loads during the second target period (e.g., a power slack period and a power off-peak period), or when the remaining power of the energy storage device is less than or equal to a first threshold. Compared to the method where AC loads can only draw power from the grid, the solution provided in this application effectively improves the flexibility of supplying power to AC loads. Moreover, by configuring the first target period as a peak electricity consumption period and the second target period as a power slack period and a power off-peak period, not only can the grid load be effectively balanced and grid stability improved, but the electricity costs of AC loads during peak electricity consumption periods can also be effectively reduced, i.e., the electricity cost of AC loads is reduced.

[0050] Figure 4 This is a schematic diagram of another power supply system provided in an embodiment of this application. For example... Figure 4 As shown, the power supply system also includes a switching circuit 50. Furthermore, both the AC terminal of the DC / AC converter 20 and the AC load are connected to the power grid through this switching circuit 50. That is, one end of the switching circuit 50 is connected to the power grid, and the other end is connected to the AC terminal of the DC / AC converter 20 and the AC load, respectively.

[0051] The controller 40 is also used to control the switching circuit 50 to open during the first target time period, and to control the switching circuit 50 to close during the second target time period, or when the remaining power of the energy storage device 30 is less than or equal to the first threshold.

[0052] Based on the connection relationship of the aforementioned switching circuit 50, it can be seen that when the controller 40 controls the switching circuit 50 to open, the AC load is disconnected from the power grid. That is, the AC load is prevented from drawing power from the power grid. At this time, the DC / AC converter 20 converts the DC power from the energy storage device 30 into AC power to supply power to the AC load, ensuring the normal operation of the AC load. When the controller 40 controls the switching circuit 50 to close, the AC load is connected to the power grid. At this time, the AC load can directly draw power from the power grid.

[0053] By adding a switching circuit 50, the AC load can be disconnected from the power grid during the first target time period, and the AC terminal of the DC / AC converter 20 can also be disconnected from the power grid. In other words, the DC / AC converter 20 can operate offline during the first target time period. Therefore, the DC / AC converter 20 does not need to have grid-connection capabilities, reducing the performance requirements for the DC / AC converter 20. Furthermore, since the DC / AC converter 20 does not feed power to the grid during operation, there is no need to apply for grid connection with the power grid company, avoiding the registration process for grid connection applications.

[0054] In one embodiment, the controller 40 is further configured to send a start command to the DC / AC converter 20 during a first target time period to instruct the DC / AC converter 20 to start. For example, the controller 40 may send a start command to the DC / AC converter 20 at the start of the first target time period (such as peak electricity consumption period) if it is determined that the remaining power of the energy storage device 30 is greater than a first threshold.

[0055] Furthermore, the controller 40 is also configured to send a shutdown command to the DC / AC converter 20 during a second target time period, or when the remaining power of the energy storage device 30 is less than or equal to a first threshold, to instruct the DC / AC converter 20 to shut down. For example, the controller 40 may send a shutdown command to the DC / AC converter 20 at the start of the second target time period, or when it detects that the remaining power of the energy storage device 30 has dropped to the first threshold.

[0056] "DC / AC converter 20 startup" can refer to the DC / AC converter 20 performing power conversion operations, that is, the DC / AC converter 20 converts the DC power on the DC bus into AC power and outputs it. "DC / AC converter 20 shutdown" can refer to the DC / AC converter 20 ceasing to perform power conversion operations, that is, the DC / AC converter 20 not outputting AC power to the AC load.

[0057] In this embodiment, when an AC load needs to draw power from the energy storage device 30, the DC / AC converter 20 must be in the startup state to achieve power conversion from DC to AC. When the AC load draws power from the grid, the DC / AC converter 20 can be shut down. This not only avoids impacting the grid or AC load but also prevents unnecessary power consumption waste.

[0058] For example, such as Figure 4 As shown, a communication connection is established between the controller 40 and the DC / AC converter 20 via a signal line. The controller 40 can send start or shutdown commands to the DC / AC converter 20 through this signal line. This signal line can be an RS-485 bus or a controller area network (CAN) bus, etc.

[0059] In one embodiment, the DC / AC converter 20 may not have grid-connection capability, meaning it does not support grid-connection operation. Correspondingly, a switching circuit 50 can be provided in the power supply system. Furthermore, in this scenario, if the DC / AC converter 20 is also running when the switching circuit 50 is closed, it may impact the power grid or AC load. Therefore, in this embodiment, when the energy storage device 30 needs to supply power to the AC load through the DC / AC converter 20, for example during the first target time period, the controller 40 can first control the switching circuit 50 to open, and then control the DC / AC converter 20 to start. When the AC load needs to be supplied power through the power grid, for example during the second target time period, or when the remaining power of the energy storage device 30 is less than or equal to a first threshold, the controller 40 can first control the DC / AC converter 20 to shut down, and then control the switching circuit 50 to close. This effectively avoids the DC / AC converter 20 impacting the power grid or AC load, ensuring stable operation of both the power grid and the AC load.

[0060] In one embodiment, the DC / AC converter 20 can have grid-connection capability, meaning it supports grid-connected operation. In this scenario, a switching circuit 50 can also be included in the power supply system. Furthermore, there is no need to limit the control sequence of the switching circuit 50 and the DC / AC converter 20. That is, when the energy storage device 30 needs to supply power to the AC load through the DC / AC converter 20, the controller 40 can first control the DC / AC converter 20 to start, and then control the switching circuit 50 to open. When the AC load needs to be supplied with power from the grid, the controller 40 can first control the switching circuit 50 to close, and then control the DC / AC converter 20 to shut down. This ensures that the power supply system can continuously supply power to the AC load, preventing operation interruption due to AC load power failure.

[0061] Alternatively, when AC loads need to be powered from the mains, controller 40 can simply close switch circuit 50 without shutting down DC / AC converter 20. Furthermore, controller 40 can adjust the output power of DC / AC converter 20 to keep it in an unloaded state. That is, controller 40 can adjust the output power of DC / AC converter 20 so that the AC load draws power only from the mains and not from DC / AC converter 20.

[0062] In one embodiment, for scenarios where the DC / AC converter 20 has grid-connection capabilities, the power supply system may not require the switching circuit 50. Correspondingly, when the energy storage device 30 needs to supply power to the AC load through the DC / AC converter 20, the controller 40 can directly control the DC / AC converter 20 to start, at which point the DC / AC converter 20 operates in grid-connected mode. When the AC load needs to be supplied with power through the grid, the controller 40 can directly control the DC / AC converter 20 to shut down.

[0063] Figure 5 This is a schematic diagram of another power supply system provided in an embodiment of this application. For example... Figure 5 As shown, the power supply system may also include an electricity meter 60, one end of which is connected to the power grid, and the other end is connected to the AC terminal of the AC / DC converter 10, the AC terminal of the DC / AC converter 20, and the AC load, respectively. Furthermore, a communication connection is established between the controller 40 and the electricity meter 60 via a signal line.

[0064] The electricity meter 60 can be a bidirectional meter, meaning it can detect both power flowing out of and into the grid. When the DC / AC converter 20 is operating in grid-connected mode, the controller 40 can adjust the output power of the DC / AC converter 20 based on the power detected by the meter 60, thus achieving closed-loop control of the DC / AC converter 20's output power. For example, during the first target period (such as peak electricity consumption), if the controller 40 detects power flowing into the grid through the meter 60, it can control the DC / AC converter 20 to reduce its output power, enabling zero-power grid feeding.

[0065] In one embodiment, the DC / AC converter 20 is further configured to report an alarm signal to the controller 40 if startup fails. The controller 40 is also configured to enable the power grid to supply power to the AC load based on the alarm signal. For example, in a scenario where the power supply system also includes a switching circuit 50, the controller 40 can control the switching circuit 50 to close based on the alarm signal, thereby enabling the power grid to supply power to the AC load. In a scenario where the power supply system does not include the switching circuit 50, the controller 40 can control the DC / AC converter 20 to remain in a powered-off state based on the alarm signal, thereby enabling the power grid to supply power to the AC load.

[0066] For example, the DC / AC converter 20 can start up and begin timing after receiving a start command from the controller 40. If the DC / AC converter 20 fails to start within the target time, or fails to start after N attempts, it can report an alarm signal to the controller 40. Here, N can be an integer greater than 1, for example, N can be 3.

[0067] It is understood that the aforementioned target duration can be a pre-configured normal startup duration in the DC / AC converter 20, for example, the target duration can be 1 minute. After receiving a startup command, the DC / AC converter 20 can execute the startup command. If the DC / AC converter 20 fails to start and the timed duration has not reached the target duration, the DC / AC converter 20 can attempt to start again. If startup fails within the target duration, or if the number of startup failures reaches N, the DC / AC converter 20 can report an alarm signal to the controller 40 to indicate a fault in the DC / AC converter 20. For example, the DC / AC converter 20 can report an alarm signal to the controller 40 via a signal line.

[0068] For example, DC / AC converter 20 can determine whether it has started successfully by detecting the voltage at its AC terminals. If the voltage at the AC terminals of DC / AC converter 20 reaches a preset range, DC / AC converter 20 can determine that it has started successfully. If the voltage at the AC terminals of DC / AC converter 20 does not reach the preset range, DC / AC converter 20 can determine that it has failed to start.

[0069] It's also understandable that in scenarios like base stations or communication equipment rooms, AC loads mainly consist of air conditioners and lighting equipment. Air conditioners account for the majority of the load power, and as motor-induced loads, they have large and varied starting inrush currents. The DC / AC converter 20 bears these inrush currents, which may lead to overcurrent triggering protection during startup. Therefore, a protection or shutdown mechanism must be implemented during the startup phase of the DC / AC converter 20 to prevent startup failures and abnormal AC load power supply.

[0070] In this embodiment, since the DC / AC converter 20 can report an alarm signal to the controller 40 when it fails to start up, the controller 40 can control the switching circuit 50 to close again based on the alarm signal, and / or control the DC / AC converter 20 to remain in the off state. Therefore, it can be ensured that the power grid can continue to supply power to the AC load, thereby ensuring that the AC load can operate normally.

[0071] In one embodiment, the controller 40 is configured to, during a first target time period, if the remaining power of the energy storage device 30 is greater than a first threshold, control the DC / AC converter 20 to convert the DC power of the energy storage device 30 into AC power to supply power to the AC load.

[0072] It is understandable that if the remaining power of the energy storage device 30 is less than or equal to the first threshold, it cannot effectively supply power to the AC load. To ensure the normal operation of the AC load, the controller 40 also needs to restore the power supply from the grid to the AC load. For example, the controller 40 also needs to control the switching circuit 50 to close again, and / or control the DC / AC converter 20 to shut down. In this embodiment, the controller 40 determines that the remaining power of the energy storage device 30 is greater than the first threshold during the first target time period before controlling the DC / AC converter 20 to supply power to the AC load. This ensures that the AC load can operate normally and avoids repeatedly switching the power supply mode of the AC load.

[0073] In one embodiment, the DC / AC converter 20 is a bidirectional power converter, meaning it can convert both direct current (DC) and alternating current (AC). Correspondingly, the controller 40 is also configured to, during a third target time period, control the AC / DC converter 10 to convert the AC power from the grid to DC to charge the energy storage device 30, and control the DC / AC converter 20 to convert the AC power from the grid to DC to charge the energy storage device 30. This third target time period does not overlap with the aforementioned first target time period.

[0074] In this embodiment, the aforementioned third target time period can refer to the time period during which the power grid charges the energy storage device 30. Furthermore, the third target time period can be a pre-configured time period in the controller 40, and its range can be flexibly adjusted according to the needs of the application scenario. For example, in areas implementing peak-valley electricity pricing, the third target time period can be a period with lower electricity prices. For instance, the third target time period may include: a low-consumption period, and / or, a period of reduced consumption.

[0075] It is understood that the third target period may partially overlap with the aforementioned second target period. For example, the third target period may belong to the second target period, meaning the second target period includes the third target period. For instance, the second target period may include both a flat period and a trough period, and the third target period may at least include the trough period.

[0076] It is also understood that the controller 40 can control the AC / DC converter 10 and DC / AC converter 20 to prioritize charging the energy storage device 30 during off-peak hours. If the energy storage device 30 is not fully charged during the off-peak period, the controller 40 can control the AC / DC converter 10 and DC / AC converter 20 to continue charging the energy storage device 30 during the off-peak period. Alternatively, if there is only an off-peak period between two adjacent peak periods, after the energy storage device 30 discharges during the first peak period, the controller 40 can control the AC / DC converter 10 and DC / AC converter 20 to charge the energy storage device 30 during the off-peak period between the two peak periods. This ensures that the energy storage device 30 can continue discharging after the second peak period arrives.

[0077] Based on the above analysis, the solution provided in this application embodiment allows the power supply system to charge the energy storage device 30 via the power grid during the third target period (e.g., off-peak electricity period, and / or, a period of reduced electricity consumption), and then discharge the energy storage device 30 during the first target period (e.g., peak electricity period) to supply power to the AC load. Therefore, on the one hand, it enables peak-shifting electricity consumption, effectively improving the load factor and equipment utilization of the power grid; on the other hand, it effectively reduces the electricity cost of AC loads and increases peak-shifting benefits.

[0078] It is also understood that the DC / AC converter 20 in this embodiment can also be a unidirectional converter, meaning that the DC / AC converter 20 may not need to have the function of converting AC power to DC power. Accordingly, during the aforementioned third target time period, the energy storage device 30 can be charged solely by the AC / DC converter 10.

[0079] like Figure 4 and Figure 5 As shown, the DC bus in the power supply system is also connected to a DC load, which refers to a load powered by DC electricity. For example, the power supply system provided in this application embodiment can be applied to power supply scenarios such as communication equipment rooms or base stations, and correspondingly, the DC load may include BBU and RRU, etc.

[0080] In one embodiment, the controller 40 is further configured to control the energy storage device 30 to supply power to the DC load during a first target time period. For example, the controller 40 may control the energy storage device 30 to supply power to the DC load during the first target time period, and when the remaining power of the energy storage device 30 is greater than a first threshold. Furthermore, the controller 40 is also configured to control the AC / DC converter 10 to convert the AC power from the grid into DC power to supply power to the DC load during a second target time period, or when the remaining power of the energy storage device 30 is less than or equal to the first threshold.

[0081] Therefore, the solution provided in this application embodiment can not only realize peak-shifting power consumption for AC loads, but also peak-shifting power consumption for DC loads, thereby effectively improving the load factor and equipment utilization rate of the power grid, and effectively increasing the peak-shifting benefits of power-consuming units.

[0082] In one embodiment, the controller 40 is further configured to control the output voltage of the energy storage device 30 to be higher than the voltage of the DC terminal of the AC / DC converter 10 during a first target time period. This enables the energy storage device 30 to discharge power to the DC bus, thereby supplying power to DC loads and, via the DC / AC converter 20, to AC loads.

[0083] For example, the controller 40 can control the output voltage of the energy storage device 30 to be higher than the voltage of the DC terminal of the AC / DC converter 10 during a first target period and when the remaining power of the energy storage device 30 is greater than a first threshold.

[0084] In one embodiment, the controller 40 can control the energy storage device 30 to raise its output voltage and / or control the AC / DC converter 10 to lower its DC terminal voltage, so that the output voltage of the energy storage device 30 is higher than the DC terminal voltage of the AC / DC converter 10. For example, assume that the initial values ​​of the output voltage of the energy storage device 30 and the DC terminal voltage of the AC / DC converter 10 are both 53.5V. When the energy storage device 30 needs to discharge, the controller 40 can control the energy storage device 30 to raise its output voltage to 54.5V or 55V, or the controller 40 can control the AC / DC converter 10 to lower its DC terminal voltage to 50V or 48V. After the energy storage device 30 begins to discharge, the AC / DC converter 10 enters an unloaded state.

[0085] like Figure 4 and Figure 5 As shown, a communication connection is established between the controller 40 and the energy storage device 30 via a signal line. A communication connection is also established between the controller 40 and the AC / DC converter 10 via a signal line. The controller 40 can send voltage adjustment commands to the energy storage device 30 and / or the AC / DC converter 10 via these signal lines, causing the energy storage device 30 and / or the AC / DC converter 10 to adjust the voltage on their DC bus side. The aforementioned signal lines can be RS-485 buses or CAN buses, etc.

[0086] Understandably, the controller 40 is also used to control the output voltage of the energy storage device 30 to be lower than or equal to the voltage of the DC terminal of the AC / DC converter 10 during the second and third target periods, or when the remaining power of the energy storage device 30 is less than or equal to the first threshold. This allows the energy storage device 30 to stop discharging power to the DC bus, thereby enabling the AC / DC converter 10 to draw power from the grid and supply power to the DC load.

[0087] For example, controller 40 can control energy storage device 30 to reduce its output voltage and / or control AC / DC converter 10 to raise its DC terminal voltage, so that the output voltage of energy storage device 30 is lower than or equal to the DC terminal voltage of AC / DC converter 10. For example, controller 40 can control energy storage device 30 and / or control AC / DC converter 10 to restore its initial voltage.

[0088] In one embodiment, the controller 40 is also configured to, if a power grid outage (i.e., a mains power outage) is detected, control the DC / AC converter 20 to convert the DC power from the energy storage device 30 into AC power to supply power to the AC load. That is, in the event of a mains power outage, the energy storage device 30 can provide backup power to the AC load.

[0089] For example, when a power grid outage is detected and the remaining power of the energy storage device 30 is greater than a second threshold, the controller 40 can control the DC / AC converter 20 to convert the DC power of the energy storage device 30 into AC power to supply power to the AC load.

[0090] It is understood that the second threshold can be equal to or greater than the first threshold. Specifically, if the second threshold is equal to the first threshold, then after a power outage, if the remaining power in the energy storage device 30 is greater than the first threshold, the energy storage device 30 can simultaneously supply power to both DC and AC loads.

[0091] If the second threshold is greater than the first threshold, then after a power outage, the energy storage device 30 can simultaneously supply power to both DC and AC loads when the remaining power is greater than the second threshold. When the remaining power is greater than the first threshold but less than or equal to the second threshold, the energy storage device 30 can stop supplying power to the AC load and supply power only to the DC load. That is, the energy storage device 30 can prioritize supplying power to the DC load to ensure that the DC load can continue to operate.

[0092] For example, the second threshold can be equal to the product of the energy storage device 30's charge level when fully charged and a second proportionality coefficient, which can be a number greater than the first proportionality coefficient and less than 1. For example, the second proportionality coefficient can be 0.5 or 0.6, etc.

[0093] In one embodiment, after a power grid outage, the energy storage device 30 may only supply power to the DC load without supplying power to the AC load, so as to ensure that the DC load can continue to operate.

[0094] In one embodiment, the switching circuit 50 in the power supply system includes a relay or a switching transistor. The relay may be an automatic transfer switch (ATS). The switching transistor may be a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT), etc.

[0095] Since the switching circuit 50 is used to control the switching on and off of AC power, it can also be called an AC switch or an AC bypass switch. Alternatively, it can also be called a changeover switch.

[0096] It is understood that the switching circuit 50 may also include a drive circuit for a relay (or a switching transistor), and the controller 40 can establish a communication connection with this drive circuit via a signal line. The controller 40 can send a closing command or a closing command to the drive circuit via the signal line. The drive circuit can control the relay (or switching transistor) to close based on the closing command, thereby closing the switching circuit 50. The drive circuit can also control the relay (or switching transistor) to turn off based on the closing command, thereby turning off the switching circuit 50.

[0097] In one embodiment, the controller 40 may be a microcontroller unit (MCU), a complex programmable logic device (CPLD), or a field programmable gate array (FPGA), etc. Furthermore, the controller 40 may also be referred to as a monitoring unit.

[0098] refer to Figures 3 to 5 It can be seen that controller 40 is also connected to the DC bus, meaning that controller 40 is also powered by the DC bus. Alternatively, it can be understood that controller 40 is also a type of DC load. Therefore, when energy storage device 30 is discharging, controller 40 is powered by energy storage device 30; after energy storage device 30 stops discharging, controller 40 is powered by AC / DC converter 10, or by both AC / DC converter 10 and DC / AC converter 20.

[0099] In one embodiment, reference continues... Figure 5 The power supply system also includes an AC distribution unit 70. One end of the AC distribution unit 70 is connected to the power grid, for example, via a meter 60. The other end of the AC distribution unit 70 is connected to the AC terminal of the AC / DC converter 10. If the power supply system does not include a switching circuit 50, the other end of the AC distribution unit 70 is also connected to the AC load and the AC terminal of the DC / AC converter 20. If the power supply system includes a switching circuit 50, the other end of the AC distribution unit 70 is connected to the switching circuit 50. The AC distribution unit 70 is used to split the AC power from the power grid into two paths: one path is transmitted to the AC / DC converter 10, and the other path is transmitted to the AC load and the AC terminal of the DC / AC converter 20, or the other path is transmitted to the switching circuit 50.

[0100] The following text is in the format of Figure 4 Taking the power supply system shown as an example, the process of AC load off-peak discharge (hereinafter referred to as AC off-peak discharge) for energy storage devices in this power supply system will be introduced. (Reference) Figure 6 The process of this AC staggered discharge is as follows:

[0101] First, after the AC peak discharge begins, that is, after the first target period (such as the peak electricity consumption period) begins, the controller 40 controls the switching circuit 50 to disconnect and starts the DC / AC converter 20 so that the energy storage device 30 supplies power to the AC load through the DC / AC converter 20.

[0102] Understandably, after the AC peak-shaving discharge begins, the controller 40 can control the voltage of the energy storage device 30 to rise, and / or control the DC terminal voltage of the AC / DC converter 10 to fall, so that the energy storage device 30 can discharge. Furthermore, the discharge energy of the energy storage device 30 can supply power to both the DC load and the AC load.

[0103] Continue to refer to Figure 6 The controller 40 can time the duration of the peak-shaving discharge. When the peak-shaving discharge duration reaches the set duration, i.e., the end of the first target period, or when the SOC of the energy storage device 30 drops to the threshold (i.e., the first threshold mentioned above), the controller 40 can control the DC / AC converter 20 to shut down and control the switching circuit 50 to close. At this time, the AC peak-shaving discharge process ends, and the AC load is powered by the grid.

[0104] After the AC peak-shaving discharge ends, the energy storage device 30 enters either a charging waiting phase or a charging phase. For example, the energy storage device 30 can prioritize charging during off-peak electricity demand periods, and then charge during periods of moderate electricity demand. During the charging waiting phase, the energy storage device 30 does not charge.

[0105] Figure 7 This is another flowchart of AC peak-shaving discharge provided in the embodiments of this application, and Figure 7 Also Figure 4 The power supply system shown is used as an example for explanation. Figure 7 As shown, the process of AC staggered discharge is as follows:

[0106] First, after the AC peak-shaving discharge begins, i.e., after the first target time period (such as peak electricity consumption period) starts, the controller 40 first checks whether the SOC of the energy storage device 30 is higher than the threshold. If the SOC of the energy storage device 30 is not higher than the threshold, the controller 40 can determine that the energy storage device 30 cannot continue to discharge, and therefore will not execute the subsequent AC peak-shaving discharge process. If the SOC of the energy storage device 30 is higher than the threshold, the control switch circuit 50 is disconnected, and the DC / AC converter 20 is started.

[0107] Continue to refer to Figure 7The DC / AC converter 20 checks whether the startup was successful. If it fails to start and the timeout period has not exceeded the target duration, the DC / AC converter 20 attempts to start again. If the DC / AC converter 20 fails to start due to timeout, it can report a fault alarm (i.e., the alarm signal mentioned above) to the controller 40. The controller 40 can then control the DC / AC converter 20 to shut down and control the switching circuit 50 to close, so that the power grid can supply power to the AC load.

[0108] Continue to refer to Figure 7 If the DC / AC converter 20 starts successfully, it can convert the DC power from the energy storage device 30 into AC power to supply the AC load. Furthermore, the controller 40 can time the duration of the peak-shifting discharge, continuously monitoring the SOC of the energy storage device 30 during this time. If the SOC of the energy storage device 30 drops to a threshold (i.e., the first threshold mentioned above), the controller 40 can shut down the DC / AC converter 20 and close the switching circuit 50. Alternatively, if the SOC of the energy storage device 30 is higher than the threshold, but the peak-shifting discharge duration reaches the set duration (i.e., the first target time period ends), the controller 40 can also shut down the DC / AC converter 20 and close the switching circuit 50. At this point, the AC peak-shifting discharge process ends, and the AC load is powered by the grid.

[0109] It is understood that the power supply system provided in this application embodiment may include one or more AC / DC converters 10 and one or more DC / AC converters 20. The DC terminals of the multiple AC / DC converters 10 and the multiple DC / AC converters 20 are all connected in parallel to a DC bus. Furthermore, the power supply system may include one or more energy storage devices 30, which may also be connected in parallel to the DC bus. The energy storage devices 30 may include lithium batteries or accumulators.

[0110] In summary, this application provides a power supply system in which, during a first target period (e.g., peak electricity consumption), an energy storage device supplies power to the AC load via a DC / AC converter. Furthermore, during a second target period (e.g., a consumption buffer period and an off-peak period), or when the remaining power in the energy storage device is less than or equal to a threshold, the power grid supplies power to the AC load. Compared to methods where AC loads can only draw power from the grid, the solution provided in this application effectively improves the flexibility of supplying power to AC loads. Moreover, by configuring the first target period as a peak electricity consumption period and the second target period as a consumption buffer period and an off-peak period, not only can the grid load be effectively balanced and grid stability improved, but the electricity cost of AC loads during peak electricity consumption periods can also be effectively reduced.

[0111] This application also provides a power supply control method, which can be applied to the power supply system provided in the above embodiments, for example, it can be applied to systems such as... Figure 3 or Figure 4 The power supply system is shown. Furthermore, this method can be executed by a controller within the power supply system. (See reference...) Figure 3 and Figure 4 The power supply system also includes: an AC / DC converter 10, a DC / AC converter 20, and an energy storage device 30. For example... Figure 8 As shown, the power supply control method includes:

[0112] Step 101: During the first target time period, control the DC / AC converter to convert the DC power of the energy storage device into AC power to supply AC load.

[0113] For example, the first target period mentioned above could be the peak electricity consumption period. During this peak period, energy storage devices can supply power to AC loads, which can not only effectively balance the grid load and improve grid stability, but also effectively reduce the electricity cost of AC loads.

[0114] In one embodiment, step 101 may include: during a first target time period, if the remaining power of the energy storage device is detected to be greater than a first threshold, then controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load. This ensures that the energy storage device can effectively supply power to the AC load, avoiding repeated switching of the AC load's power supply mode.

[0115] Step 102: In the second target time period, or when the remaining power of the energy storage device is less than or equal to the first threshold, the power grid supplies power to the AC load.

[0116] The first target time period and the second target time period do not overlap. For example, the second target time period may include a power level easing period and a low power consumption period.

[0117] In one embodiment, the power supply system further includes a switching circuit; both the AC terminal of the DC / AC converter and the AC load are used to connect to the power grid through the switching circuit. Accordingly, step 101 may further include: controlling the switching circuit to open during a first target time period. Step 102 may further include: controlling the switching circuit to close during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold.

[0118] In one embodiment, step 101 may include: sending a start command to the DC / AC converter during a first target time period to instruct the DC / AC converter to start. Step 102 may include: sending a shutdown command to the DC / AC converter during a second target time period, or when the remaining power of the energy storage device is less than or equal to a first threshold, to instruct the DC / AC converter to shut down.

[0119] For example, the above-mentioned start and shutdown commands can both be sent from the controller to the DC / AC converter via signal lines (such as CAN bus or RS-485 bus).

[0120] In one embodiment, after step 101 above, the power supply control method may further include: if the DC / AC converter fails to start, then the power grid supplies power to the AC load.

[0121] Understandably, after receiving a start command from the controller, the DC / AC converter can perform a start-up operation, that is, it can perform a power conversion operation from DC to AC. If the DC / AC converter fails to start within the target time after receiving the start command, it can report an alarm signal to the controller. The controller can then use this alarm signal to allow the grid to supply power to the AC load. For example, the controller can control the switching circuit to close, and / or control the DC / AC converter to remain in a powered-off state so that the grid can supply power to the AC load. Here, a DC / AC converter start-up failure could mean that the voltage at the AC terminal of the DC / AC converter has not reached a preset range.

[0122] In one embodiment, the DC / AC converter in this power supply system is a bidirectional power converter. Furthermore, continuing to refer to... Figure 8 The power supply control method provided in this application embodiment may further include:

[0123] Step 103: During the third target time period, control the AC / DC converter to convert the AC power from the grid into DC power to charge the energy storage device, and control the DC / AC converter to convert the AC power from the grid into DC power to charge the energy storage device.

[0124] The third target time period does not overlap with the first target time period. However, the third target time period may partially overlap with the second target time period; for example, the third target time period may belong to the second target time period. For instance, the third target time period could be a low-demand period. By charging energy storage devices during this low-demand period, not only can the charging cost of energy storage devices be effectively reduced, but the grid load can also be effectively balanced, improving grid stability.

[0125] It is understandable that the DC / AC converter in the power supply system can also be a unidirectional converter. Accordingly, in step 103 above, the AC / DC converter can simply convert the AC power from the grid into DC power to charge the energy storage device.

[0126] Continue to refer to Figure 8 The power supply control provided in this application embodiment may further include:

[0127] Step 104: If a power outage is detected, control the DC / AC converter to convert the DC power from the energy storage device into AC power to supply AC loads.

[0128] For example, step 104 above may include: if a power grid outage is detected and the remaining power of the energy storage device is greater than a second threshold, then controlling the DC / AC converter to convert the DC power of the energy storage device into AC power to supply AC load.

[0129] The second threshold is greater than the first threshold. This means that after a power outage, if the remaining power of the energy storage device is greater than the second threshold, the device can simultaneously supply power to both DC and AC loads. If the remaining power of the energy storage device is greater than the first threshold but not greater than the second threshold, it can stop supplying power to the AC load and continue supplying power to the DC load. This ensures the continuous operation of the DC load.

[0130] In one embodiment, after a power grid outage, the energy storage device may only supply power to the DC load without supplying power to the AC load, in order to ensure that the DC load can continue to operate.

[0131] It is understood that the above power supply control method has essentially the same implementation method and technical effect as the power supply system provided in the foregoing embodiments. Therefore, for the sake of brevity, the implementation method and technical effect of the power supply control method will not be described again here.

[0132] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "at least one" refers to one or more, and "multiple" refers to two or more.

[0133] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0134] The above description is merely an optional implementation of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power supply system, characterized in that, The power supply system includes: an AC / DC converter, a DC / AC converter, an energy storage device, and a controller; The AC terminal of the AC / DC converter is used to connect to the power grid, and the DC terminal of the AC / DC converter is connected to the energy storage device. The DC terminal of the DC / AC converter is connected to the energy storage device, and the AC terminal of the DC / AC converter is used to connect to the power grid and the AC load. The controller is configured to, during a first target time period, control the DC / AC converter to convert the DC power of the energy storage device into AC power to supply the AC load, and during a second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold, enable the power grid to supply power to the AC load. The first target time period and the second target time period do not overlap.

2. The power supply system according to claim 1, characterized in that, The power supply system further includes a switching circuit; the AC terminal of the DC / AC converter and the AC load are used to connect to the power grid through the switching circuit. The controller is configured to control the switching circuit to open during the first target time period, and to control the switching circuit to close during the second target time period, or when the remaining power of the energy storage device is less than or equal to the threshold.

3. The power supply system according to claim 1 or 2, characterized in that, The controller is used for: During the first target time period, a start command is sent to the DC / AC converter to instruct the DC / AC converter to start. During the second target time period, or when the remaining power of the energy storage device is less than or equal to the threshold, a shutdown command is sent to the DC / AC converter to instruct the DC / AC converter to shut down.

4. The power supply system according to claim 3, characterized in that, The DC / AC converter is used to report an alarm signal to the controller if the startup fails. The controller is also configured to enable the power grid to supply power to the AC load based on the alarm signal.

5. The power supply system according to any one of claims 1 to 4, characterized in that, The controller is configured to, during the first target time period, if the remaining power of the energy storage device is greater than the threshold, control the DC / AC converter to convert the DC power of the energy storage device into AC power to supply power to the AC load.

6. The power supply system according to any one of claims 1 to 5, characterized in that, The controller is also configured to, if a power outage is detected in the power grid, control the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load.

7. The power supply system according to any one of claims 1 to 6, characterized in that, The DC / AC converter is a bidirectional power converter; The controller is further configured to, during a third target time period, control the AC / DC converter to convert the AC power of the power grid into DC power to charge the energy storage device, and control the DC / AC converter to convert the AC power of the power grid into DC power to charge the energy storage device; wherein the first target time period and the third target time period do not overlap.

8. A power supply control method, characterized in that, The method is applied to a power supply system, which includes an AC / DC converter, a DC / AC converter, and an energy storage device. The AC terminal of the AC / DC converter is connected to the power grid, the DC terminal of the AC / DC converter is connected to the energy storage device, the DC terminal of the DC / AC converter is connected to the energy storage device, and the AC terminal of the DC / AC converter is connected to the power grid and an AC load. During the first target time period, the DC / AC converter is controlled to convert the DC power of the energy storage device into AC power to supply power to the AC load. During the second target time period, or when the remaining power of the energy storage device is less than or equal to a threshold, the power grid supplies power to the AC load. The first target time period and the second target time period do not overlap.

9. The method according to claim 8, characterized in that, The power supply system further includes a switching circuit; the AC terminal of the DC / AC converter and the AC load are used to connect to the power grid through the switching circuit. The step of controlling the DC / AC converter to convert the DC power of the energy storage device into AC power to supply power to the AC load during the first target time period includes: controlling the switching circuit to disconnect during the first target time period; The step of supplying power to the AC load by the power grid during the second target period, or when the remaining power of the energy storage device is less than or equal to the threshold, includes: controlling the switching circuit to close during the second target period, or when the remaining power of the energy storage device is less than or equal to the threshold.

10. The method according to claim 8 or 9, characterized in that, The step of controlling the DC / AC converter to convert the DC power of the energy storage device into AC power to supply power to the AC load during the first target time period includes: sending a start command to the DC / AC converter during the first target time period to instruct the DC / AC converter to start. The step of supplying power to the AC load by the power grid during the second target period, or when the remaining power of the energy storage device is less than or equal to a threshold, includes: sending a shutdown command to the DC / AC converter during the second target period, or when the remaining power of the energy storage device is less than or equal to a threshold, to instruct the DC / AC converter to shut down.

11. The method according to claim 10, characterized in that, The method further includes: If the DC / AC converter fails to start, the power grid will supply power to the AC load.

12. The method according to any one of claims 8 to 11, characterized in that, The step of controlling the DC / AC converter to convert the DC power from the energy storage device into AC power to supply power to the AC load during the first target time period includes: During the first target time period, if the remaining power of the energy storage device is greater than the threshold, the DC / AC converter is controlled to convert the DC power of the energy storage device into AC power to supply power to the AC load.

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