A power supply system and a power supply scheduling method

Abstract

The embodiment of the application discloses a power supply system and a power supply scheduling method, wherein the controller can control the second DC-DC conversion circuit to make the lithium battery or lithium battery group in the energy storage device in a charging state or a discharging state according to the output total power of at least one photovoltaic component and the total DC load power. Furthermore, the first state of charge value at the end of this time is dynamically adjusted according to the second state of charge value at the end of the last time and the charging threshold range, and the energy storage device is discharged to the first state of charge value at the end of this time to stop discharging, so that solar energy is fully utilized and resource waste is avoided.

Description

Technical Field

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

[0002] With societal development and rising living standards, people have become inseparable from the internet. Internet connectivity requires the assistance of communication base stations, which are ubiquitous. Therefore, how to provide more energy-efficient power to these base stations has become a key concern. Consequently, there is a demand for photovoltaic (PV) upgrades to communication base stations. PV upgrades refer to adding photovoltaic power to the basic power supply system by installing photovoltaic modules that meet or exceed the load power requirements, forming a photovoltaic power supply system that prioritizes PV power. With the increasing maturity of the technology and the decreasing cost of related photovoltaic modules, photovoltaic power supply has been widely adopted. Solar energy is a typical representative of renewable energy, and using PV power upgrades can reduce power supply costs.

[0003] However, existing photovoltaic power supply systems used in communication base stations have certain drawbacks. They cannot make reasonable and full use of solar energy, resulting in a waste of resources and failing to meet people's requirements. Summary of the Invention

[0004] This application provides a power supply system and power supply scheduling method to make reasonable and full use of solar energy and avoid resource waste.

[0005] In a first aspect, embodiments of this application provide a power supply system, comprising: a controller, a DC bus, at least one photovoltaic module, a first DC-DC conversion circuit, a second DC-DC conversion circuit, and an energy storage device; wherein, a first terminal of the first DC-DC conversion circuit is connected to the at least one photovoltaic module, a second terminal of the first DC-DC conversion circuit is connected to the DC bus, a first terminal of the second DC-DC conversion circuit is connected to the energy storage device, and a second terminal of the second DC-DC conversion circuit is connected to the DC bus. Furthermore, the first DC-DC conversion circuit is used to convert the initial DC voltage of each of the at least one photovoltaic module into a target DC voltage and output it to the DC bus. The second DC-DC conversion circuit is used to put the energy storage device into a charging state or a discharging state. The controller is configured to determine the first state of charge (SOC) value at the end of the current discharge based on the second SOC value of the energy storage device at the end of the previous charge and the charging threshold range; and to control the second DC-DC conversion circuit to put the energy storage device in the charging state or the discharging state based on the total output power of the at least one photovoltaic module and the total DC load power, and to stop discharging the energy storage device when it discharges to the determined first SOC value, that is, when the SOC value of the energy storage device during discharge decreases to the determined first SOC value at the end of the current discharge, the controller controls the second DC-DC conversion circuit to end the discharge of the energy storage device.

[0006] In this embodiment, the controller can control the second DC-DC conversion circuit to put the energy storage device into a charging or discharging state based on the total output power of at least one photovoltaic module and the total power of the DC load. Thus, based on the relationship between the total output power of the photovoltaic module and the total power of the DC load, the controller can achieve the effect of charging the energy storage device through solar photovoltaic power generation and controlling the energy storage device to discharge and supply power to the load on the DC bus.

[0007] Furthermore, the controller can determine the first state of charge (SOC) at the end of the current discharge based on the second SOC value of the energy storage device at the end of the previous charge and the charging threshold range. This allows for dynamic adjustment of the SOC at the end of the current discharge based on the relationship between the second SOC value and the charging threshold range. When the SOC value of the energy storage device decreases to the determined SOC at the end of the current discharge, the second DC-DC conversion circuit is controlled to terminate the discharge. This allows for control of the discharge of the lithium battery or lithium battery pack within the energy storage device based on the dynamically adjusted SOC value, thus maximizing solar energy utilization and avoiding resource waste. Additionally, this maintains a shallow charge / discharge state for the lithium battery or lithium battery pack, reducing the risk of over-discharge and extending its lifespan. It also avoids the risk of site downtime due to insufficient backup power.

[0008] The power supply system described in this application embodiment can be applied to communication base stations to supply power to the DC loads within the base stations. This enables the communication base stations to undergo solar power upgrades and to make reasonable and full use of solar energy, avoiding resource waste.

[0009] In this embodiment, the charging and discharging of the lithium battery or lithium battery pack is controlled by a controller to store excess solar energy. When photovoltaic power generation is insufficient to power the communication equipment, the energy generated by charging the lithium battery or lithium battery pack is used first, maximizing the utilization of solar energy. Furthermore, by determining a first state of charge value, the lithium battery or lithium battery pack can reserve backup capacity during discharge, reducing the risk of over-discharge and avoiding the risk of site failure due to insufficient backup power. This ensures maximum utilization of photovoltaic power generation while maximizing the reserve capacity of the lithium battery or lithium battery pack, guaranteeing the power supply security of the communication equipment.

[0010] For example, a first terminal of the first DC-DC conversion circuit is connected to at least one photovoltaic module 1, meaning the first terminal of the first DC-DC conversion circuit is connected to one or more photovoltaic modules. When there is only one photovoltaic module, it can be connected to the first terminal of the first DC-DC conversion circuit, and the second terminal of the first DC-DC conversion circuit is connected to a DC bus. Alternatively, when there are multiple photovoltaic modules, they can be connected to the first terminal of the first DC-DC conversion circuit in series and / or parallel, and the second terminal of the first DC-DC conversion circuit is connected to a DC bus.

[0011] For example, the first DC-DC conversion circuit can be a Buck circuit, i.e., a step-down circuit, to realize the process of energy transfer from the photovoltaic module to the DC bus. This application does not impose many restrictions on the specific type of step-down circuit.

[0012] This application does not limit the rated voltage on the DC bus. For example, if the DC load includes a -48V communication device, the rated voltage on the DC bus can be set to -48V, then the DC bus can be a -48V DC bus.

[0013] For example, in this embodiment of the application, the target DC voltage converted by the first DC-DC converter circuit can be approximately equal to the rated voltage on the DC bus. Alternatively, the target DC voltage converted by the first DC-DC converter circuit can also be higher than the rated voltage on the DC bus, further stabilizing the input voltage to the DC bus. Of course, the specific value by which the target DC voltage converted by the first DC-DC converter circuit is higher than the rated voltage on the DC bus can be determined according to the actual application requirements, and is not limited here.

[0014] For example, in the embodiments of this application, there may be one or more first DC-DC conversion circuits, and each first DC-DC conversion circuit is connected to at least one photovoltaic module.

[0015] For example, the second DC-DC conversion circuit can be a circuit that can perform both boost and buck functions. Furthermore, the second DC-DC conversion circuit also includes a switching transistor, which can be controlled by a pulse width modulation (PWM) signal. The controller controls the switching frequency of the switching transistor in the second DC-DC conversion circuit by setting PWM signals with different duty cycles, thereby adjusting the voltage across the second DC-DC conversion circuit to either boost or buck, thus realizing the discharge or charging process of the energy storage device.

[0016] For example, an energy storage device may include one or more lithium batteries. When the energy storage device includes one lithium battery, a first terminal of a second DC-DC converter is connected to the lithium battery, and the second DC-DC converter adjusts the voltage of its first terminal (i.e., the voltage at the port where the second DC-DC converter is connected to the lithium battery) to put the lithium battery into a charging or discharging state. Alternatively, when the energy storage device includes multiple lithium batteries, the multiple lithium batteries may be connected in series and / or parallel to form a lithium battery pack. In this case, a first terminal of the second DC-DC converter is connected to the lithium battery pack, and the second DC-DC converter adjusts the voltage of its first terminal (i.e., the voltage at the port where the second DC-DC converter is connected to the lithium battery pack) to put the lithium battery pack into a charging or discharging state.

[0017] For example, in this embodiment of the application, when the energy storage device is in a discharging state, the voltage at the first terminal of the adjusted second DC-DC conversion circuit can be higher than the voltage at its second terminal, thereby stabilizing the input voltage to the DC bus. Of course, the specific value by which the voltage at the first terminal of the adjusted second DC-DC conversion circuit is higher than the rated voltage on the DC bus can be determined according to the actual application requirements, and is not limited here.

[0018] For example, in this embodiment of the application, when the energy storage device is in a charging state, the voltage at the first terminal of the adjusted second DC-DC conversion circuit can be lower than the voltage at its second terminal, thereby stably charging the energy storage device using the voltage on the DC bus. Of course, the specific value by which the voltage at the first terminal of the adjusted second DC-DC conversion circuit is lower than the rated voltage on the DC bus can be determined according to the actual application requirements, and is not limited here.

[0019] For example, the second DC-DC conversion circuit can be a standalone device or a device or module integrated with an energy storage device. This application does not limit the specific form of the second DC-DC conversion circuit.

[0020] For example, in the embodiments of this application, there may be one or more second DC-DC conversion circuits, and each second DC-DC conversion circuit is connected to an energy storage device.

[0021] In this embodiment, the total power of the DC load includes the sum of the power of the loads connected to the DC bus. Exemplarily, the sum of the power of the loads connected to the DC bus can be the sum of the rated power of all DC loads connected to the DC bus. Alternatively, the sum of the power of the loads connected to the DC bus can also be the sum of the peak / maximum power of all DC loads connected to the DC bus; no specific limitation is made here.

[0022] In some possible implementations, the controller is further configured to: acquire the first state of charge (SOC) value of the energy storage device at the end of the previous discharge. Specifically, the controller is configured to, when the second SOC value at the end of the previous charge is within the charging threshold range, determine the first SOC value at the end of the previous discharge as the first SOC value at the end of the current discharge. Thus, when the second SOC value of the energy storage device at the end of the previous charge meets the charging threshold range (i.e., the second SOC value of the energy storage device at the end of the previous charge is within the charging threshold range), it indicates that the lithium battery or lithium battery pack in the energy storage device is operating in an optimal charging state. In this case, there is no need to additionally adjust the first SOC value of the lithium battery or lithium battery pack in the energy storage device at the end of the current discharge to ensure that the second SOC value after the next charge does not change significantly and remains within the charging threshold range. Therefore, the first SOC value of the lithium battery or lithium battery pack in the energy storage device at the end of the previous discharge can be directly used as the first SOC value at the end of the current discharge, thereby reducing the number of adjustments and reducing power consumption.

[0023] In some possible implementations, the controller is specifically used to adjust the first state of charge (SOC) at the end of the previous discharge and determine it as the first SOC at the end of the current discharge when the second SOC at the end of the previous charge is not within the charging threshold range. Thus, when the second SOC of the lithium battery or lithium battery pack in the energy storage device does not meet the charging threshold range at the end of the previous charge (i.e., the second SOC is not within the charging threshold range), it indicates that the lithium battery or lithium battery pack is not operating in an optimal charging state. In this case, it is necessary to adjust the first SOC of the lithium battery or lithium battery pack at the end of the current discharge so that the second SOC also changes after the next charge. This allows for dynamic adjustment of the first SOC to adjust the second SOC, enabling efficient utilization of solar energy while ensuring backup power and shallow charging / discharging.

[0024] In some possible implementations, the controller is specifically configured to, when the second state of charge (SBC) value at the end of the previous charging cycle is less than a value within the charging threshold range, increase the first SBC value at the end of the previous discharging cycle and determine it as the first SBC value at the end of the current discharging cycle. Conversely, when the second SBC value at the end of the previous charging cycle is greater than a value within the charging threshold range, decrease the first SBC value at the end of the previous discharging cycle and determine it as the first SBC value at the end of the current discharging cycle. This allows the controller to adjust the first SBC value based on the relationship between the second SBC value at the end of the previous charging cycle and a value within the charging threshold range, thereby increasing or decreasing the adjusted first SBC value.

[0025] In some possible implementations, the controller is specifically configured to increase the first state of charge value at the end of the previous discharge by a first adjustment step to determine the first state of charge value at the end of the current discharge. Furthermore, it may decrease the first state of charge value at the end of the previous discharge by a second adjustment step to determine the first state of charge value at the end of the current discharge. This allows the first state of charge value to be adjusted according to a set adjustment step, thereby increasing or decreasing the adjusted first state of charge value.

[0026] In some possible implementations, the first adjustment step size and the second adjustment step size are the same. Of course, the first adjustment step size and the second adjustment step size can also be different; for example, the first adjustment step size can be greater than or less than the second adjustment step size.

[0027] In some possible implementations, the second DC-DC conversion circuit is also used to put the energy storage device into a static state. Specifically, the controller is used to control the second DC-DC conversion circuit to put the energy storage device into the discharge state when the total output power of at least one photovoltaic module is less than the total power of the DC load, and to control the second DC-DC conversion circuit to put the energy storage device into the static state when the state of charge value of the energy storage device during discharge decreases to a first state of charge value determined at the end of this discharge. This allows the energy storage device to be in a state of neither charging nor discharging.

[0028] In some possible implementations, the controller is further configured to, after controlling the second DC-DC conversion circuit to bring the energy storage device into the static state, and when the total output power of at least one photovoltaic module is greater than the total power of the DC load, control the second DC-DC conversion circuit to bring the energy storage device into the charging state. This allows the energy storage device to begin charging and enter the charging state.

[0029] In some possible implementations, the power supply system further includes an AC bus and a communication power supply. The AC bus is connected to the AC power grid, and the communication power supply is connected to both the AC bus and the DC bus. Furthermore, the communication power supply is used to convert the AC power on the AC bus into DC power and output it to the DC bus when the total output power of at least one photovoltaic module is less than the total power of the DC load after the energy storage device is in the static state. Thus, when the solar energy is insufficient to independently power the DC load after the energy storage device discharges to the first state of charge value, the DC load is powered by connecting to the AC power grid, either through mains power or a combination of mains power and solar energy.

[0030] In some possible implementations, the controller is further configured to, after controlling the second DC-DC conversion circuit to bring the energy storage device to the static state, and when the total output power of at least one photovoltaic module is less than the total DC load power, control the communication power supply to convert the AC power on the AC bus to DC power and output it to the DC bus. This allows the controller to control the connection to the mains power.

[0031] In some possible implementations, the power supply system further includes a maximum power point tracking (MPPT) controller connected to each of the at least one photovoltaic module. The MPPT controller is configured to track the output voltage of each photovoltaic module and adjust the power of each photovoltaic module to its maximum power point. For example, the MPPT controller may be connected to a connection port between a first DC-DC conversion circuit and the photovoltaic module. In this case, the MPPT controller tracks the output voltage of that port and adjusts the power of the photovoltaic module to its maximum power point.

[0032] Among them, maximum power point tracking (MPPT) is achieved by detecting the input voltage and current in real time, calculating the input power, and using certain pre-set algorithms to enable the system to track the maximum power point of the input, thereby allowing the photovoltaic module 103 to output more electrical energy to the downstream stage and increase power generation.

[0033] For example, the maximum power point tracking controller can be a standalone device or a device or module integrated with the first DC-DC conversion circuit. For instance, the device or module integrating the maximum power point tracking controller with the first DC-DC conversion circuit can be a superimposed optical controller. This application does not limit the specific form of the maximum power point tracking controller.

[0034] Secondly, embodiments of this application also provide a power supply scheduling method, which includes: determining a first state of charge (SOC) value at the end of the current discharge based on a second SOC value of the energy storage device at the end of the previous charging and a charging threshold range; controlling the energy storage device to be in a discharging state based on the total output power of at least one photovoltaic module and the total DC load power, and stopping the discharge when the energy storage device discharges to the determined first SOC value; and controlling the energy storage device to be in a charging state based on the total output power of the at least one photovoltaic module and the total DC load power. Specifically, controlling a second DC-DC converter circuit to put the energy storage device in either the charging state or the discharging state based on the total output power of the at least one photovoltaic module and the total DC load power. When the SOC value of the energy storage device during discharge decreases to the determined first SOC value at the end of the current discharge, the second DC-DC converter circuit is controlled to end the discharge of the energy storage device.

[0035] In some possible implementations, the power supply scheduling method further includes: acquiring the first state of charge (SOC) value of the energy storage device at the end of the previous discharge. Furthermore, determining the first SOC value at the end of the current discharge based on the second SOC value of the energy storage device at the end of the previous charge and a charging threshold range includes: if the second SOC value at the end of the previous charge is within the charging threshold range, determining the first SOC value at the end of the previous discharge as the first SOC value at the end of the current discharge; if the second SOC value at the end of the previous charge is not within the charging threshold range, adjusting the first SOC value at the end of the previous discharge and determining it as the first SOC value at the end of the current discharge.

[0036] In some possible implementations, determining the first state of charge (SOC) value at the end of the previous discharge as the first SOC value at the end of the current discharge includes: when the second SOC value at the end of the previous charge is less than a value within the charging threshold range, increasing the first SOC value at the end of the previous discharge and determining it as the first SOC value at the end of the current discharge; when the second SOC value at the end of the previous charge is greater than a value within the charging threshold range, decreasing the first SOC value at the end of the previous discharge and determining it as the first SOC value at the end of the current discharge.

[0037] In some possible implementations, the step of increasing the first state of charge value at the end of the previous discharge and determining it as the first state of charge value at the end of the current discharge includes: increasing the first state of charge value at the end of the previous discharge by a first adjustment step and then determining it as the first state of charge value at the end of the current discharge.

[0038] In some possible implementations, determining the first state of charge value at the end of the current discharge after reducing the first state of charge value at the end of the previous discharge includes: determining the first state of charge value at the end of the current discharge after reducing the first state of charge value at the end of the previous discharge by a second adjustment step.

[0039] In some possible implementations, the first adjustment step size and the second adjustment step size are the same.

[0040] These or other aspects of this application will become more apparent from the description of the following embodiments. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of another power supply system provided in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the structure of a first DC-DC conversion circuit provided in an embodiment of this application;

[0044] Figure 4 An adjustment relationship diagram of a first state of charge value and a second state of charge value is provided for embodiments of this application;

[0045] Figure 5 This is a schematic diagram of a first state of charge value provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The specific operational methods in the method embodiments can also be applied to the device embodiments or system embodiments. It should be noted that in the description of this application, "at least one" refers to one or more, where "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "And / or" describes 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, and B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, it should be understood that in the description of this application, words such as "first" and "second" are only used for distinguishing the purpose of description and should not be construed as indicating or implying relative importance or order.

[0047] It should be noted that in the embodiments of this application, "connection" refers to electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components, such as the connection between A and B. Alternatively, A can be directly connected to C, and C can be directly connected to B, with A and B connected through C. In the embodiments of this application, "coupling" can refer to the coupling between two windings through electromagnetic fields, that is, the transmission of electrical energy between the two windings through electromagnetic fields, mainly including the energy conversion process of electrical energy - magnetic potential energy - electrical energy.

[0048] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0049] The power supply system described in this application embodiment can be applied to communication base stations to supply power to the DC loads within the base stations. This enables the communication base stations to undergo solar power upgrades and to make reasonable and full use of solar energy, avoiding resource waste.

[0050] The following is based on Figure 1 and Figure 2 Taking the illustrated power supply system as an example, the power supply system provided in the embodiments of this application will be described first. See [link to relevant documentation]. Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of this application. Figure 2This is a schematic diagram of another power supply system provided in an embodiment of this application. The power supply system may include: a controller 101, a DC bus 102, at least one photovoltaic module 103, a first DC-DC conversion circuit 104, a second DC-DC conversion circuit 105, an energy storage device 106, and a DC load 107.

[0051] In some embodiments of this application, see Figure 1 and Figure 2 As shown, the first terminal (e.g., the input terminal) of the first DC-DC converter circuit 104 is connected to at least one photovoltaic module 103, meaning the first terminal (e.g., the input terminal) of the first DC-DC converter circuit 104 is connected to one or more photovoltaic modules 103. When there is only one photovoltaic module 103, it can be connected to the first terminal (e.g., the input terminal) of the first DC-DC converter circuit 104, and the second terminal (e.g., the output terminal) of the first DC-DC converter circuit 104 is connected to the DC bus 102. Alternatively, when there are multiple photovoltaic modules 103, they can be connected to the first terminal (input terminal) of the first DC-DC converter circuit 104 in series and / or parallel, and the second terminal (e.g., the output terminal) of the first DC-DC converter circuit 104 is connected to the DC bus 102.

[0052] For example, in this embodiment of the application, the photovoltaic module 103 is used to convert solar energy into DC power for output. Furthermore, the first DC-DC conversion circuit 104 can be used to convert the initial DC voltage of each of the at least one connected photovoltaic module 103 into a target DC voltage and then output it to the DC bus 102.

[0053] For example, see Figure 3 As shown, the first DC-DC conversion circuit 104 can be a Buck circuit, i.e., a step-down circuit, to realize the process of energy transfer from the photovoltaic module 103 to the DC bus 102. This application embodiment does not impose many restrictions on the specific type of step-down circuit. The step-down circuit is used to reduce and adjust the input voltage; optionally... Figure 3 This is a schematic diagram of a Buck circuit. See also... Figure 3 As shown, the step-down circuit of the first DC-DC converter circuit 104 includes a first capacitor C1, a first switch Q1, a second switch Q2, an inductor L, and a second capacitor C2. The first switch Q1 is a switching transistor, and the second switch Q2 can be either a switching transistor or a diode. Figure 3Taking the second switch Q2 as an example, the first terminal of the first capacitor C1 is connected to the first terminal of the first switch Q1, the second terminal of the first switch Q1 is connected to the first terminal of the inductor L and the first terminal of the second switch Q2, the third terminal of the first switch Q1 is used to input a signal to control the state of the first switch Q1, the second terminal of the second switch Q2 is connected to the second terminal of the first capacitor C1 and the first terminal of the second capacitor C2, the third terminal of the second switch Q2 is used to input a signal to control the state of the second switch Q2, and the second terminal of the inductor L is connected to the second terminal of the second capacitor C2.

[0054] Optionally, the aforementioned switching transistor can be controlled by a pulse width modulation (PWM) signal. The controller 101 controls the switching frequency of the aforementioned switching transistor by setting PWM signals with different duty cycles, and inputs the DC voltage output by the photovoltaic module 103 to the DC bus 102 after step-down adjustment. Exemplarily, the aforementioned switching transistor can be one or more of various types of switching devices, such as relays, metal oxide semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), insulated gate bipolar transistors (IGBTs), and silicon carbide (SiC) power transistors. These types will not be listed individually in this embodiment.

[0055] This application does not limit the rated voltage on the DC bus 102. For example, if the DC load 107 includes a -48V communication device, the rated voltage on the DC bus 102 can be set to -48V, then the DC bus 102 can be a -48V DC bus.

[0056] For example, in this embodiment of the application, the target DC voltage converted by the first DC-DC converter 104 can be approximately equal to the rated voltage on the DC bus 102. Alternatively, the target DC voltage converted by the first DC-DC converter 104 can also be higher than the rated voltage on the DC bus 102, further stabilizing the input voltage to the DC bus 102. Of course, the specific value by which the target DC voltage converted by the first DC-DC converter 104 is higher than the rated voltage on the DC bus 102 can be determined according to the needs of the actual application, and is not limited here.

[0057] In the embodiments of this application, see Figure 2As shown, the power supply system may further include a maximum power point tracking (MPPT) controller 111, which is connected to each of at least one photovoltaic module 103. The MPPT controller 111 tracks the output voltage of each photovoltaic module 103 and adjusts the power of each photovoltaic module 103 to its maximum power point. For example, the MPPT controller 111 is connected to the connection port of the first DC-DC conversion circuit 104 and the photovoltaic module 103. The MPPT controller 111 then tracks the output voltage of that port and adjusts the power of the photovoltaic module 103 to its maximum power point.

[0058] Among them, maximum power point tracking (MPPT) is achieved by detecting the input voltage and current in real time, calculating the input power, and using certain pre-set algorithms to enable the system to track the maximum power point of the input, thereby allowing the photovoltaic module 103 to output more electrical energy to the downstream stage and increase power generation.

[0059] For example, the maximum power point tracking controller 111 can be a standalone device or a device or module integrated with the first DC-DC conversion circuit 104. For instance, the device or module integrating the maximum power point tracking controller 111 with the first DC-DC conversion circuit 104 can be a superimposed light controller 101. This application does not limit the specific form of the maximum power point tracking controller 111.

[0060] For example, in the embodiments of this application, there may be one or more first DC-DC conversion circuits, and each first DC-DC conversion circuit is connected to at least one photovoltaic module.

[0061] In some embodiments of this application, see Figure 1 and Figure 2 As shown, the first terminal of the second DC-DC converter circuit 105 is connected to the energy storage device 106, and the second terminal of the second DC-DC converter circuit 105 is connected to the DC bus 102. Furthermore, the second DC-DC converter circuit 105 can be used to adjust the voltage of its first terminal (i.e., the first terminal of the second DC-DC converter circuit 105) to put the energy storage device 106 into a charging or discharging state.

[0062] For example, the second DC-DC conversion circuit 105 can be a circuit that can perform both boost and buck functions. Furthermore, the second DC-DC conversion circuit 105 also includes a switching transistor, which can be controlled by a pulse width modulation (PWM) signal. The controller 101 controls the switching frequency of the switching transistor in the second DC-DC conversion circuit 105 by setting PWM signals with different duty cycles, thereby adjusting the voltage across the second DC-DC conversion circuit 105 by boosting or bucking it to achieve the discharge or charging process of the energy storage device 106. For example, the type of the switching transistor can be one or more of various switching devices such as a relay, a metal-oxide-semiconductor field-effect transistor (MOSFET), a bipolar junction transistor (BJT), an insulated-gate bipolar transistor (IGBT), and a silicon carbide (SiC) power transistor; these will not be listed exhaustively in this embodiment.

[0063] For example, see Figure 2 As shown, the energy storage device 106 may include one or more lithium batteries 1061. When the energy storage device 106 includes one lithium battery, the first terminal of the second DC-DC converter 105 is connected to the lithium battery, and the second DC-DC converter 105 adjusts the voltage of its first terminal (i.e., the voltage at the port where the second DC-DC converter 105 is connected to the lithium battery) to keep the lithium battery in a charging or discharging state. Alternatively, when the energy storage device 106 includes multiple lithium batteries, these multiple lithium batteries may be connected in series and / or parallel to form a lithium battery pack. In this case, the first terminal of the second DC-DC converter 105 is connected to the lithium battery pack, and the second DC-DC converter 105 adjusts the voltage of its first terminal (i.e., the voltage at the port where the second DC-DC converter 105 is connected to the lithium battery pack) to keep the lithium battery pack in a charging or discharging state.

[0064] For example, in this embodiment of the application, when the energy storage device 106 is in a discharging state, the voltage at the first terminal of the adjusted second DC-DC conversion circuit 105 can be higher than the voltage at its second terminal, thereby stabilizing the input voltage to the DC bus 102. Of course, the specific value by which the voltage at the first terminal of the adjusted second DC-DC conversion circuit 105 is higher than the rated voltage on the DC bus 102 can be determined according to the actual application requirements, and is not limited here.

[0065] For example, in this embodiment of the application, when the energy storage device 106 is in a charging state, the voltage at the first terminal of the adjusted second DC-DC conversion circuit 105 can be lower than the voltage at its second terminal, thereby stably charging the energy storage device 106 with the voltage on the DC bus 102. Of course, the specific value by which the voltage at the first terminal of the adjusted second DC-DC conversion circuit 105 is lower than the rated voltage on the DC bus 102 can be determined according to the actual application requirements, and is not limited here.

[0066] For example, the second DC-DC conversion circuit 105 can be a standalone device or a device or module integrated with the energy storage device 106. This application does not limit the specific form of the second DC-DC conversion circuit 105.

[0067] For example, in the embodiments of this application, there may be one or more second DC-DC conversion circuits, and each second DC-DC conversion circuit is connected to an energy storage device.

[0068] In some embodiments of this application, the controller 101 is used to determine the first state of charge value at the end of the current discharge based on the second state of charge value of the energy storage device 106 at the end of the previous charging and the charging threshold range; and to control the second DC-DC conversion circuit 105 to put the energy storage device 106 into a charging state or a discharging state based on the total output power of at least one photovoltaic module 103 and the total power of the DC load, and to stop discharging the energy storage device 106 when it discharges to the determined first state of charge value, that is, when the energy storage device 106 discharges to the determined first state of charge value at the end of the current discharge, the controller controls the second DC-DC conversion circuit 105 to end the discharge of the energy storage device 106. For example, the controller 101 is configured to determine the first state of charge (SOC) value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the current discharge based on the second SOC value and charging threshold range at the end of the previous charge; and to control the second DC-DC converter circuit 105 to put the lithium battery or lithium battery pack in the energy storage device 106 into a charging state or a discharging state based on the total output power of at least one photovoltaic module 103 and the total DC load power, and to control the second DC-DC converter circuit 105 to end the discharge of the lithium battery or lithium battery pack in the energy storage device 106 when the SOC value of the lithium battery or lithium battery pack in the energy storage device 106 decreases to the determined first SOC value at the end of the current discharge.

[0069] In this embodiment, the controller 101 can control the second DC-DC conversion circuit 105 to keep the lithium battery or lithium battery pack in the energy storage device 106 in a charging or discharging state based on the total output power of at least one photovoltaic module 103 and the total power of the DC load. This allows the controller to charge the lithium battery or lithium battery pack using solar photovoltaic power generation and control the discharge of the lithium battery or lithium battery pack to supply power to the load on the DC bus 102, based on the relationship between the total output power of the photovoltaic module 103 and the total power of the DC load.

[0070] Furthermore, the controller 101 can determine the first state of charge (SOC) at the end of the current discharge based on the second SOC and the charging threshold range of the energy storage device 106 at the end of the previous charge. This allows for dynamic adjustment of the SOC at the end of the current discharge based on the relationship between the second SOC and the charging threshold range. When the SOC of the energy storage device 106 decreases to the determined SOC at the end of the current discharge, the second DC-DC converter circuit 105 is controlled to terminate the discharge of the energy storage device 106. This allows for control of the discharge of the lithium battery or lithium battery pack in the energy storage device 106 based on the dynamically adjusted SOC, thus fully utilizing solar energy and avoiding resource waste. Furthermore, this maintains the lithium battery or lithium battery pack in a shallow charge / discharge state, reducing the risk of over-discharge and extending its lifespan. It also avoids the risk of site failure due to insufficient backup power.

[0071] In this embodiment, the controller 101 controls the charging and discharging of the lithium battery or lithium battery pack, storing excess solar energy. When photovoltaic power generation is insufficient to power the communication equipment, the energy from charging the lithium battery or lithium battery pack is used first, maximizing the utilization of solar energy. Furthermore, by determining a first state of charge value, the lithium battery or lithium battery pack can reserve backup capacity during discharge, reducing the risk of over-discharge and avoiding the risk of site failure due to insufficient backup power. This ensures maximum utilization of photovoltaic power generation while maximizing the reserve capacity of the lithium battery or lithium battery pack, guaranteeing the power supply security of the communication equipment.

[0072] In this embodiment, the total power of the DC load includes the sum of the power of the loads connected to the DC bus 102. Exemplarily, the sum of the power of the loads connected to the DC bus 102 can be the sum of the rated power of all DC loads 107 connected to the DC bus 102. Alternatively, the sum of the power of the loads connected to the DC bus 102 can also be the sum of the peak / maximum power of all DC loads 107 connected to the DC bus 102; no specific limitation is made here.

[0073] Exemplarily, controller 101 may be a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing unit (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The controller 101 may also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0074] For example, in this embodiment, the controller 101 can directly sample the operating data and total output power of at least one photovoltaic module 103, as well as the total DC load power. For instance, the controller 101 can establish a communication connection with at least one photovoltaic module 103 and the energy storage device 106 using wired or wireless transmission. For example, wired transmission can include: wired local area network (LAN), serial bus, controller area network (CAN), and power line communication (PLC); wireless transmission can include 6G / 5G / 4G / 3G / 2G, general packet radio service (GPRS), wireless network (WiFi), Bluetooth, Zigbee, and infrared, etc.

[0075] For example, the controller 101 may acquire the total output power of at least one photovoltaic module 103 and the total DC load power at regular intervals. For instance, the controller 101 may be connected to the port where at least one photovoltaic module 103 is connected to the first DC-DC conversion circuit 104, and determine the total output power of at least one photovoltaic module 103 based on the output current and output voltage of at least one photovoltaic module 103.

[0076] For example, controller 101 is communicatively connected to energy storage device 106 to enable communication of control signals and data signals between controller 101 and energy storage device 106. For example, controller 101 can obtain the first State of Charge (SOC) value of energy storage device 106 at the end of discharge and the second SOC value of energy storage device 106 at the end of each charge cycle. For instance, controller 101 has a communication component, and energy storage device 106 further includes an SOC determination device and a communication component. The SOC determination device can detect the first SOC value of the lithium battery or lithium battery pack at the end of discharge and the second SOC value of the lithium battery or lithium battery pack at the end of charge. The communication component in controller 101 can communicate with the communication component in energy storage device 106. The communication component in energy storage device 106 can send the first and second SOC values ​​detected by the SOC determination device to the communication component in controller 101, thereby enabling controller 101 to obtain these two SOC values.

[0077] For example, controller 101 is communicatively connected to DC load 107 to acquire the total DC load power of DC load 107.

[0078] For example, the controller 101 is communicatively connected to the first DC-DC converter circuit 104 to control the switching frequency of the switching transistor in the first DC-DC converter circuit 104 through a PWM signal, thereby controlling the first DC-DC converter circuit 104 to perform a step-down operation.

[0079] For example, the controller 101 is communicatively connected to the second DC-DC converter circuit 105 to control the switching frequency of the switching transistor in the second DC-DC converter circuit 105 through a PWM signal, thereby controlling the second DC-DC converter circuit 105 to perform buck or boost operation.

[0080] In some embodiments of this application, the controller 101 is further configured to obtain the first SOC value of the energy storage device 106 at the end of the previous discharge. For example, the first SOC value of the energy storage device 106 at the end of the previous discharge can be stored in a memory, and the controller 101 can obtain the first SOC value of the energy storage device 106 at the end of the previous discharge from the memory. Optionally, the memory and the controller 101 can be integrated on a single circuit board. Alternatively, through a communication connection between the controller 101 and the energy storage device 106, the controller 101 can obtain the first SOC value of the energy storage device 106 at the end of the previous discharge.

[0081] For example, the SCO value is typically in the form of a percentage, and the charging threshold range can be 85% to 95%. This application does not limit the charging threshold range; it can be determined according to the needs of the actual application.

[0082] In some embodiments of this application, when the second SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the previous charge meets the charging threshold range, that is, when the second SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the previous charge is within the charging threshold range, it can be said that the lithium battery or lithium battery pack is working in a better charging state. At this time, it is not necessary to adjust the first SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of this discharge so that the second SOC value after the next charge does not change much and is also within the charging threshold range. Therefore, the first SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the previous discharge can be directly used as the first SOC value at the end of this discharge, thereby reducing the number of adjustments and reducing power consumption. Specifically, the controller 101 can be used to determine the first SOC value at the end of the previous discharge as the first SOC value at the end of the current discharge when the second SOC value at the end of the previous charge is within the charging threshold range.

[0083] In some embodiments of this application, when the second SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the previous charge does not meet the charging threshold range, that is, when the second SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of the previous charge is not within the charging threshold range, it indicates that the lithium battery or lithium battery pack is not working in an optimal charging state. At this time, it is necessary to adjust the first SOC value of the lithium battery or lithium battery pack in the energy storage device 106 at the end of this discharge so that the second SOC value after the next charge also changes. This allows for dynamic adjustment of the first SOC value to adjust the second SOC value, which can both make reasonable use of solar energy and ensure backup power and shallow charging and discharging. Specifically, the controller 101 can be used to adjust the first SOC value at the end of the previous discharge and determine it as the first SOC value at the end of the current discharge when the second SOC value at the end of the previous charge is not within the charging threshold range.

[0084] For example, the first SOC value can be adjusted based on the relationship between the second SOC value at the end of the previous charging and the values ​​within the charging threshold range, so that the adjusted first SOC value increases. Specifically, the controller 101 is specifically configured to: when the second SOC value at the end of the previous charging is less than the values ​​within the charging threshold range, increase the first SOC value at the end of the previous discharging and determine it as the first SOC value at the end of the current discharging. That is, when the second SOC value at the end of the previous charging is less than all values ​​or the minimum value within the charging threshold range, increase the first SOC value at the end of the previous discharging and determine it as the first SOC value at the end of the current discharging. Optionally, the first SOC value at the end of the previous discharging is increased by a first adjustment step and then determined as the first SOC value at the end of the current discharging. That is, the adjusted and increased first SOC value is the first SOC value at the end of the current discharging, and this first SOC value satisfies the following formula: SOC11 m =SOC11 m-1 +ΔSOC11. Where SOC11 m SOC11 represents the first SOC value at the end of the m-th discharge (i.e., the first SOC value at the end of this discharge). m-1 ΔSOC11 represents the first SOC value at the end of the (m-1)th discharge (i.e., the first SOC value at the end of the previous discharge), and ΔSOC11 represents the first adjustment step size. This can reduce the discharge of energy storage device 106, ensure backup power duration, ensure shallow discharge of energy storage device 106, and improve the service life of energy storage device 106.

[0085] For example, ΔSOC11 is a percentage, and this application does not limit the specific value of ΔSOC11. For example, ΔSOC11 can be predetermined, for example, it can be a value obtained based on experience, or it can be a value obtained in the experimental stage.

[0086] For example, the corresponding ΔSOC11 can be the same each time the first SOC value is adjusted, so that the first SOC value can be increased based on the same amount of change, thus improving uniformity.

[0087] For example, the ΔSOC11 corresponding to each adjustment of the first SOC value can also be different, or partially the same and partially different. This allows for the use of different amounts of change to increase the first SOC value, thereby improving the adaptive capability.

[0088] For example, the first SOC value can be adjusted based on the relationship between the second SOC value at the end of the previous charging and the values ​​within the charging threshold range, so that the adjusted first SOC value is lowered. Specifically, the controller 101 is specifically configured to: when the second SOC value at the end of the previous charging is greater than the values ​​within the charging threshold range, lower the first SOC value at the end of the previous discharging and determine it as the first SOC value at the end of the current discharging. That is, when the second SOC value at the end of the previous charging is greater than all values ​​or the maximum value within the charging threshold range, lower the first SOC value at the end of the previous discharging and determine it as the first SOC value at the end of the current discharging. Optionally, the first SOC value at the end of the previous discharging is lowered by a second adjustment step and then determined as the first SOC value at the end of the current discharging. That is, the adjusted and lowered first SOC value is the first SOC value at the end of the current discharging, and this first SOC value satisfies the following formula: SOC12 m =SOC12 m-1 -ΔSOC12. Where SOC12 m SOC12 represents the first SOC value at the end of the m-th discharge (i.e., the first SOC value at the end of this discharge). m-1 ΔSOC12 represents the first SOC value at the end of the (m-1)th discharge (i.e., the first SOC value at the end of the previous discharge), and ΔSOC12 represents the second adjustment step size. This allows for full utilization of solar energy.

[0089] For example, ΔSOC12 is a percentage, and this application does not limit the specific value of ΔSOC12. For example, ΔSOC12 can be predetermined, for example, it can be a value obtained based on experience, or it can be a value obtained in the experimental stage.

[0090] For example, the corresponding ΔSOC12 can be the same each time the first SOC value is adjusted, so that the first SOC value can be reduced based on the same amount of change, thus improving uniformity.

[0091] For example, the corresponding ΔSOC12 can be different each time the first SOC value is adjusted, or it can be partially the same and partially different. This allows different amounts of change to be used to reduce the first SOC value and improve the adaptive capability.

[0092] Optionally, the first adjustment step size ΔSOC11 and the second adjustment step size ΔSOC12 can be the same. Of course, the first adjustment step size ΔSOC11 and the second adjustment step size ΔSOC12 can also be different, for example, the first adjustment step size ΔSOC11 can be greater than or less than the second adjustment step size ΔSOC12.

[0093] For example, see Figure 4 , Figure 4This diagram illustrates the adjustment relationship between the first and second SOC values. Typically, the lithium battery or lithium battery pack in the energy storage device 106 initially has a certain amount of charge, which is the second SOC value SOC20 at the end of the 0th charge. Subsequently, the processor controls the second DC-DC conversion circuit 105 to discharge the lithium battery or lithium battery pack in the energy storage device 106 from SOC20, stopping the discharge when it reaches the predetermined first SOC value SOC11 at the end of the first discharge. Then, the processor controls the second DC-DC conversion circuit 105 to charge the lithium battery or lithium battery pack in the energy storage device 106, and at the end of charging, obtains the second SOC value, which is the second SOC value SOC21 at the end of the first charge. The controller 101 determines that SOC21 is less than the minimum value in the charging threshold range, and then increases SOC11 by ΔSOC11, determining it as the first SOC value SOC12 at the end of the second discharge.

[0094] Subsequently, the processor controls the second DC-DC conversion circuit 105 to discharge the lithium battery or lithium battery pack in the energy storage device 106 from SOC 22, and stops discharging when SOC 12 is reached. Then, the processor controls the second DC-DC conversion circuit 105 to charge the lithium battery or lithium battery pack in the energy storage device 106, and at the end of charging, acquires a second SOC value, which is the second SOC value SOC 22 at the end of the second charging. The controller 101 determines that SOC 22 is less than the minimum value in the charging threshold range, and then increases SOC 12 by ΔSOC 11, determining it as the first SOC value SOC 13 at the end of the third discharge.

[0095] Subsequently, the processor controls the second DC-DC conversion circuit 105 to discharge the lithium battery or lithium battery pack in the energy storage device 106 from SOC 22, and stops discharging when it reaches SOC 13. Then, the processor controls the second DC-DC conversion circuit 105 to charge the lithium battery or lithium battery pack in the energy storage device 106, and at the end of charging, obtains a second SOC value. This second SOC value is the second SOC value SOC 23 at the end of the third charging. The controller 101 determines that SOC 23 is within the charging threshold range, and therefore sets SOC 12 as the first SOC value SOC 14 at the end of the fourth discharge, i.e., SOC 14 = SOC 12.

[0096] Subsequently, the processor controls the second DC-DC conversion circuit 105 to discharge the lithium battery or lithium battery pack in the energy storage device 106 from SOC 23, and stops discharging when it reaches SOC 14. Then, the processor controls the second DC-DC conversion circuit 105 to charge the lithium battery or lithium battery pack in the energy storage device 106, and at the end of charging, acquires a second SOC value, which is the second SOC value SOC 24 at the end of the fourth charging. The controller 101 determines that SOC 24 is higher than the maximum value in the charging threshold range, and then reduces SOC 14 by ΔSOC 12, determining it as the first SOC value SOC 15 at the end of the fifth discharge.

[0097] Next, the processor controls the second DC-DC conversion circuit 105 to discharge the lithium battery or lithium battery pack in the energy storage device 106 from SOC 24, and stops discharging when it reaches SOC 15. Then, the processor controls the second DC-DC conversion circuit 105 to charge the lithium battery or lithium battery pack in the energy storage device 106, and at the end of charging, obtains a second SOC value, which is the second SOC value SOC 25 at the end of the fourth charging. The controller 101 determines that SOC 25 is within the charging threshold range, and then sets SOC 15 as the first SOC value SOC 16 at the end of the sixth discharge. This process is then repeated.

[0098] In this embodiment, after the lithium battery or lithium battery pack in the energy storage device 106 has finished discharging, it can directly enter the charging state or enter a non-charging and non-discharging state (i.e., a static state). However, in practical applications, for example, between time A1 and time A2 of a day, the sunlight is relatively strong. At this time, the electrical energy converted by the photovoltaic module 103 using solar energy is sufficient to independently power the DC load 107, and there is still excess electricity to charge the lithium battery or lithium battery pack in the energy storage device 106, so that the energy storage can be charged to the second SOC value. Between time A2 of the day and time A1 of the next day, there is no sunlight or the sunlight is not particularly strong. When there is sunlight, the photovoltaic module 103 can use the electrical energy converted by solar energy to power the DC load 107, but it is not enough to independently power the DC load 107. When there is no sunlight, the photovoltaic module 103 cannot power the DC load 107. At this time, the lithium battery or lithium battery pack in the energy storage device 106 can be controlled to discharge to power the DC load 107. However, in practical applications, it's possible that the lithium battery or lithium battery pack in energy storage device 106 is in a discharging state and has discharged to the first SOC value determined at the end of this discharge. If, between time A1 and time A2 of the next day, it can not only supply power to the DC load 107 via solar energy, but also charge the lithium battery or lithium battery pack in energy storage device 106 using the electrical energy converted from solar energy by photovoltaic module 103. Alternatively, it's also possible that the lithium battery or lithium battery pack in energy storage device 106 is in a discharging state and has discharged to the first SOC value determined at the end of this discharge, but before time A1 and time A2 of the next day, it has been between time A2 and time A1 of the next day. During this time, there is no sunlight or the sunlight is not strong, so it's impossible to charge the lithium battery or lithium battery pack in energy storage device 106 via solar energy. In this case, the lithium battery or lithium battery pack in energy storage device 106 can be controlled to enter a static state. This static state is the state where the lithium battery or lithium battery pack in energy storage device 106 is neither charging nor discharging. In other words, the second DC-DC conversion circuit 105 is used not only to adjust the lithium battery or lithium battery pack in the energy storage device 106 to be in a charging or discharging state, but also to adjust the lithium battery or lithium battery pack in the energy storage device 106 to be in a static state. Furthermore, the controller 101 is specifically used to control the second DC-DC conversion circuit 105 to put the energy storage device 106 into a discharging state when the total output power of at least one photovoltaic module 103 is less than the total power of the DC load, and to control the second DC-DC conversion circuit 105 to put the energy storage device 106 into a static state when the SOC value of the energy storage device 106 during discharge decreases to a determined first SOC value at the end of this discharge. The time points A1 and A2 mentioned above are only illustrative examples and are not specific time points in actual applications.

[0099] For example, the controller 101 can control the switching frequency of the switching transistor in the second DC-DC conversion circuit 105 through the PWM signal, so that the voltage at the first terminal and the voltage at the second terminal of the second DC-DC conversion circuit 105 are the same, thereby putting the lithium battery or lithium battery pack in the energy storage device 106 in a static state.

[0100] For example, after the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, if solar energy can charge the lithium battery or lithium battery pack in the energy storage device 106 between time A1 and time A2 on the next day, the lithium battery or lithium battery pack in the energy storage device 106 can be controlled to enter the charging state. Specifically, the controller 101 is also used to control the second DC-DC conversion circuit 105 to put the energy storage device 106 into the charging state after controlling the second DC-DC conversion circuit 105 to put the energy storage device 106 into a static state, when the total output power of at least one photovoltaic module 103 is greater than the total DC load power.

[0101] For example, when the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, solar energy cannot supply power to the DC load 107, or it can supply power to the DC load 107 but is insufficient to supply power to the DC load 107 independently. In this case, mains power can be connected to supply power to the DC load 107 through a combination of mains power and solar energy. See specifically... Figure 1 and Figure 2 The power supply system may further include an AC bus 109 and a communication power supply 108. The AC bus 109 is connected to the AC power grid 110, and the communication power supply 108 is connected to both the AC bus 109 and the DC bus 102. The communication power supply 108 is used to convert the AC power on the AC bus 109 into DC power and output it to the DC bus 102 when the energy storage device 106 is in a static state and the total output power of at least one photovoltaic module 103 is less than the total DC load power.

[0102] For example, the mains power connection can be controlled by the controller 101. Specifically, the controller 101 is also used to: after controlling the second DC-DC conversion circuit 105 to put the energy storage device 106 into a static state, when the total output power of at least one photovoltaic module 103 is less than the total DC load power, control the communication power supply to convert the AC power on the AC bus into DC power and output it to the DC bus 102. That is, the controller 101 can control the communication power supply to work so that the communication power supply converts the AC power on the AC bus into DC power and outputs it to the DC bus 102.

[0103] For example, the voltage on the DC bus 102 can also be detected by the communication power supply to determine whether to connect the mains power. Specifically, when the communication power supply detects that the voltage on the DC bus 102 is less than the rated voltage, it converts the AC power on the AC bus into DC power and outputs it to the DC bus 102.

[0104] For example, see Figure 1 and Figure 2 The communication power supply includes, but is not limited to, a power management unit (PMU) 1081, a power supply unit (PSU) 1082, and a battery 1083. The PMU 1081 and PSU 1082 work together to convert AC power on the AC bus into DC power, which is then output to the DC bus 102. Furthermore, the battery 1083 can serve as a backup battery. In the event of a mains power outage and after the energy storage device 106 has discharged, the battery 1083 can be activated to supply power to the DC load 107. For example, the PMU 1081 and PSU 1082 work together to convert the charge in the battery 1083 and output it to the DC bus 102.

[0105] For example, the processor can be a standalone device. Alternatively, the processor can be a device or module integrated with the first DC-DC conversion circuit 104; for example, the controller 101 can be disposed in the superimposed optical controller 101. Alternatively, the processor can be a device or module integrated with the communication power supply; this application does not limit the specific form of the processor.

[0106] This application embodiment also provides a power supply scheduling method applied to the power supply system provided in the above embodiments. The power supply scheduling method includes: determining a first SOC value at the end of the current discharge based on the second SOC value of the energy storage device 106 at the end of the previous charging and the charging threshold range; controlling the energy storage device 106 to be in a discharging state based on the total output power of at least one photovoltaic module 103 and the total DC load power, and stopping the discharging when the energy storage device 106 discharges to the determined first state of charge value; controlling the energy storage device 106 to be in a charging state based on the total output power of at least one photovoltaic module 103 and the total DC load power, that is, controlling the second DC-DC conversion circuit 105 to make the energy storage device 106 be in a charging state or a discharging state. Wherein, when the SOC value of the energy storage device 106 during discharge decreases to the determined first SOC value at the end of the current discharge, the second DC-DC conversion circuit 105 is controlled to end the discharge of the energy storage device 106.

[0107] As one possible implementation, the power supply scheduling method further includes: obtaining the first SOC value of the energy storage device 106 at the end of the previous discharge; and determining the first SOC value at the end of the current discharge based on the second SOC value of the energy storage device 106 at the end of the previous charge and a charging threshold range, including: if the second SOC value at the end of the previous charge is within the charging threshold range, determining the first SOC value at the end of the previous discharge as the first SOC value at the end of the current discharge; if the second SOC value at the end of the previous charge is not within the charging threshold range, adjusting the first SOC value at the end of the previous discharge and determining it as the first SOC value at the end of the current discharge.

[0108] As one possible implementation, the first SOC value at the end of the previous discharge is adjusted and then determined as the first SOC value at the end of the current discharge. This includes: if the second SOC value at the end of the previous charge is less than a value within the charging threshold range, increasing the first SOC value at the end of the previous discharge and then determining it as the first SOC value at the end of the current discharge; if the second SOC value at the end of the previous charge is greater than a value within the charging threshold range, decreasing the first SOC value at the end of the previous discharge and then determining it as the first SOC value at the end of the current discharge.

[0109] As one possible implementation, the first SOC value at the end of the previous discharge is increased and then determined as the first SOC value at the end of the current discharge, which includes: increasing the first SOC value at the end of the previous discharge by a first adjustment step and then determining it as the first SOC value at the end of the current discharge.

[0110] As one possible implementation, the first SOC value at the end of the previous discharge is reduced and then determined as the first SOC value at the end of the current discharge, which includes: reducing the first SOC value at the end of the previous discharge by a second adjustment step and then determining it as the first SOC value at the end of the current discharge.

[0111] For example, the first adjustment step size and the second adjustment step size are the same.

[0112] For example, based on Figure 2 The power supply system architecture shown is combined with Figure 5 The diagram showing the first SOC value illustrates a power supply scheduling method provided in this application embodiment. See also... Figure 5 As shown, curve LS1 represents the variation of the first SOC value.

[0113] For example, during the time period from day 0 to time A2' on day m, solar power is available to charge lithium batteries or lithium battery packs, while mains power is not output, meaning the total output power of the photovoltaic module 103 is greater than the total DC load power. Specifically, the maximum power point tracking controller 111 tracks the output voltage of each photovoltaic module 103 and adjusts the power of each photovoltaic module 103 to the maximum power point, so that the photovoltaic module 103 outputs power at the maximum power point. The controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage across its terminals, charging the lithium batteries or lithium battery packs in the energy storage device 106 through the DC bus 102. When the charging of the lithium batteries or lithium battery packs in the energy storage device 106 is completed, its second SOC value is determined to be SOC2. m-1 Then the processor, based on this SOC2... m-1 Determine the first SOC value (SOC1) at the end of this discharge. m .

[0114] During the period from time A2' to time A3' on day m, solar power is available, but it is insufficient to independently power the DC load 107; that is, the total output power of the photovoltaic module 103 is less than the total power of the DC load. Specifically, the controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage across its terminals, discharging the lithium battery or lithium battery pack in the energy storage device 106 to the DC bus 102. This may cause the lithium battery or lithium battery pack in the energy storage device 106 to discharge to SOC1. m This could also cause the lithium battery or lithium battery pack in the energy storage device 106 to discharge above SOC1. m In this application, the lithium battery or lithium battery pack in the energy storage device 106 is discharged to a state of charge (SOC) higher than 1. m For example.

[0115] During the period from time A3' on day m to time A4 on day m+1, there is no solar power supply, and the lithium batteries or lithium battery packs in the energy storage device 106 continue to discharge, meaning the total output power of the photovoltaic module 103 is less than the total DC load power. Specifically, the controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage across its terminals, discharging the lithium batteries or lithium battery packs in the energy storage device 106 to the DC bus 102, causing the lithium batteries or lithium battery packs in the energy storage device 106 to discharge to SOC1. m At this time, the controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage at its two ends, so that the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, that is, the lithium battery or lithium battery pack is in a state of not charging and not discharging.

[0116] During this stage, after the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, the mains power is applied. The communication power supply converts the AC power on the AC bus into DC power and outputs it to the DC bus 102 to supply power to the DC load 107 connected to the DC bus 102 through the AC power grid.

[0117] During the period from time A4 on day m+1 to time A1 on day m+1, solar power is available, but insufficient to independently power DC load 107, thus requiring mains power connection. That is, the total output power of the photovoltaic modules 103 is less than the total power of the DC load. Specifically, the maximum power point tracking controller 111 tracks the output voltage of each photovoltaic module 103 and adjusts the power of each photovoltaic module 103 to its maximum power point, so that the photovoltaic modules 103 output power at their maximum power point. The controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage across it, so that the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, i.e., the lithium battery or lithium battery pack is in a state of neither charging nor discharging.

[0118] During this stage, after the lithium battery or lithium battery pack in the energy storage device 106 is in a static state, the mains power is applied. The communication power supply converts the AC power on the AC bus into DC power and outputs it to the DC bus 102 to supply power to the DC load 107 connected to the DC bus 102 through the AC power grid.

[0119] During the period from time A1 to time A2 on day m+1, solar power is available to charge the lithium batteries or lithium battery packs, while mains power is not output. That is, the total output power of the photovoltaic modules 103 is greater than the total power of the DC load. Specifically, the maximum power point tracking controller 111 tracks the output voltage of each photovoltaic module 103 and adjusts the power of each photovoltaic module 103 to its maximum power point, so that the photovoltaic modules 103 output power at their maximum power point. The controller 101 controls the second DC-DC conversion circuit 105 to adjust the voltage across its terminals, charging the lithium batteries or lithium battery packs in the energy storage device 106 through the DC bus 102. When the charging of the lithium batteries or lithium battery packs in the energy storage device 106 is completed, its second SOC value is determined to be SOC2. m Then the processor, based on this SOC2... m Determine the first SOC value (SOC1) at the end of the next discharge. m+1 .

[0120] The above process is then repeated, and will not be elaborated upon here.

[0121] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0122] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0123] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0124] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0125] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A power supply system, characterized in that, The power supply system includes: a controller, a DC bus, at least one photovoltaic module, a first DC-DC conversion circuit, a second DC-DC conversion circuit, and an energy storage device; The first terminal of the first DC-DC converter is connected to the at least one photovoltaic module, the second terminal of the first DC-DC converter is connected to the DC bus, the first terminal of the second DC-DC converter is connected to the energy storage device, and the second terminal of the second DC-DC converter is connected to the DC bus. The first DC-DC conversion circuit is used to: convert the initial DC voltage of each photovoltaic module in the at least one photovoltaic module into a target DC voltage and then output it to the DC bus; The second DC-DC conversion circuit is used to: put the energy storage device into a charging state or a discharging state; The controller is used for: Obtain the first state of charge value of the energy storage device at the end of the previous discharge; If the second state of charge value of the energy storage device at the end of the previous charging is within the charging threshold range, the first state of charge value at the end of the previous discharging is determined as the first state of charge value at the end of the current discharging. If the second state of charge value at the end of the previous charging is less than a value within the charging threshold range, the first state of charge value at the end of the previous discharging is increased and then determined as the first state of charge value at the end of the current discharging. If the second state of charge value at the end of the previous charging is greater than a value within the charging threshold range, the first state of charge value at the end of the previous discharging is reduced and then determined as the first state of charge value at the end of the current discharging. Based on the total output power of the at least one photovoltaic module and the total DC load power, the second DC-DC conversion circuit is controlled to put the energy storage device into the charging state or the discharging state, and the energy storage device stops discharging when it reaches the determined first state of charge value.

2. The power supply system according to claim 1, characterized in that, The controller is specifically used for: The first state of charge value at the end of the previous discharge is increased by a first adjustment step and then determined as the first state of charge value at the end of this discharge. The first state of charge value at the end of the previous discharge is reduced by a second adjustment step and then determined as the first state of charge value at the end of the current discharge.

3. The power supply system according to claim 2, characterized in that, The first adjustment step size and the second adjustment step size are the same.

4. The power supply system according to any one of claims 1-3, characterized in that, The second DC-DC conversion circuit is also used to: put the energy storage device into a static state; The controller is specifically used for: When the total output power of at least one photovoltaic module is less than the total power of the DC load, the second DC-DC conversion circuit is controlled to put the energy storage device into the discharge state, and when the state of charge value of the energy storage device during discharge decreases to the first state of charge value determined at the end of this discharge, the second DC-DC conversion circuit is controlled to put the energy storage device into the static state.

5. The power supply system according to claim 4, characterized in that, The controller is also used for: After controlling the second DC-DC conversion circuit to put the energy storage device into the static state, when the total output power of at least one photovoltaic module is greater than the total power of the DC load, the second DC-DC conversion circuit is controlled to put the energy storage device into the charging state.

6. The power supply system according to claim 4, characterized in that, The power supply system also includes: an AC bus and a communication power supply; The AC bus is connected to the AC power grid, the communication power supply is connected to the AC bus, and the communication power supply is also connected to the DC bus; The communication power supply is used to: after the energy storage device is in the static state, when the total output power of at least one photovoltaic module is less than the total power of the DC load, convert the AC power on the AC bus into DC power and output it to the DC bus.

7. The power supply system according to claim 6, characterized in that, The controller is also used for: After controlling the second DC-DC conversion circuit to put the energy storage device into the static state, when the total output power of at least one photovoltaic module is less than the total power of the DC load, the communication power supply is controlled to convert the AC power on the AC bus into DC power and output it to the DC bus.

8. The power supply system according to any one of claims 1-3, characterized in that, The power supply system further includes: a maximum power point tracking controller, which is connected to each of the at least one photovoltaic module; The maximum power point tracking controller is used to: track the output voltage of each photovoltaic module and adjust the power of each photovoltaic module to the maximum power point.

9. A power supply dispatching method, characterized in that, include: Obtain the first state of charge value of the energy storage device at the end of the last discharge; If the second state of charge value of the energy storage device at the end of the previous charging is within the charging threshold range, the first state of charge value at the end of the previous discharging is determined as the first state of charge value at the end of the current discharging. If the second state of charge value at the end of the previous charging is less than a value within the charging threshold range, the first state of charge value at the end of the previous discharging is increased and then determined as the first state of charge value at the end of the current discharging. If the second state of charge value at the end of the previous charging is greater than a value within the charging threshold range, the first state of charge value at the end of the previous discharging is reduced and then determined as the first state of charge value at the end of the current discharging. Based on the total output power of at least one photovoltaic module and the total DC load power, the energy storage device is controlled to be in a discharge state, and the discharge is stopped when the energy storage device discharges to the determined first state of charge value. The energy storage device is controlled to be in a charging state based on the total output power of the at least one photovoltaic module and the total DC load power.

10. The power supply dispatching method according to claim 9, characterized in that, The step of increasing the first state of charge value at the end of the previous discharge and determining it as the first state of charge value at the end of the current discharge includes: The first state of charge value at the end of the previous discharge is increased by a first adjustment step and then determined as the first state of charge value at the end of this discharge. The step of reducing the first state of charge value at the end of the previous discharge and determining it as the first state of charge value at the end of the current discharge includes: The first state of charge value at the end of the previous discharge is reduced by a second adjustment step and then determined as the first state of charge value at the end of the current discharge.

11. The power supply dispatching method according to claim 10, characterized in that, The first adjustment step size and the second adjustment step size are the same.

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