Optical storage and charging system and charging station

Abstract

The utility model discloses an optical storage and charging system and a charging station. The system comprises a power grid, a bus, an energy storage battery, a first DC-DC converter, a second DC-DC converter and an on-off device, the bus is connected to the power grid; a first end of the first DC-to-DC converter is connected to the energy storage battery, a second end of the first DC-to-DC converter is connected to the bus, and the second end of the first DC-to-DC converter is connected to a load terminal through the on-off device; the first end of the second DC-to-DC converter is connected to the load terminal, and the second end of the second DC-to-DC converter is connected to the bus. According to the optical storage and charging system, the cost and the size of the system can be effectively reduced, and the conversion efficiency of charging the load terminal by the energy storage battery is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery energy storage and charging, and more particularly to a photovoltaic energy storage and charging system and a charging station. Background Art

[0002] In a photovoltaic energy storage and charging system, when the charging power required by the load is greater than the grid power, energy storage batteries are needed to supplement the energy. In the current photovoltaic energy storage and charging system, when the grid and energy storage batteries charge an electric vehicle simultaneously, the power of the DC-DC converter connected to the load will be very large, which will result in its large volume and high cost. Moreover, when the energy storage battery supplements energy to the electric vehicle, it needs to go through two levels of DC-DC, with large losses and low conversion efficiency. Summary of the Utility Model

[0003] The present application is proposed to solve at least one of the above problems. According to one aspect of the present application, a photovoltaic energy storage and charging system is provided. The system includes: a power grid, a bus, an energy storage battery, a first DC-DC converter, a second DC-DC converter, and a switchable device; the bus is connected to the power grid; a first end of the first DC-DC converter is connected to the energy storage battery, a second end of the first DC-DC converter is connected to the bus, and the second end of the first DC-DC converter is connected to a load terminal via the switchable device; a first end of the second DC-DC converter is connected to the load terminal, and a second end of the second DC-DC converter is connected to the bus.

[0004] In an embodiment of the present application, the system includes a plurality of the second DC-DC converters, wherein:

[0005] A first end of each of the second DC-DC converters is respectively connected to a load terminal;

[0006] A second end of each of the second DC-DC converters is connected to the bus.

[0007] In an embodiment of the present application, the system further includes a plurality of first switches, wherein:

[0008] A first end of each of two adjacent second DC-DC converters is connected to each other via a first switch.

[0009] When the first switch connecting two adjacent second DC-DC converters is closed, the bus supplies power to the load terminal via the two adjacent second DC-DC converters.

[0010] In one embodiment of the present application, when the first switch connecting two adjacent second DC-DC converters is turned off and the switchable device is turned on, the energy storage battery supplies power to the load terminal via the first DC-DC converter, and the bus supplies power to the load terminal via the adjacent second DC-DC converter.

[0011] In one embodiment of the present application, the system further includes a second switch, and the second terminal of the first DC-DC converter is connected to the bus via the second switch.

[0012] In one embodiment of the present application, the system includes a plurality of the second DC-DC converters, a plurality of the switchable devices, and a plurality of the second switches, wherein: the first terminal of each first DC-DC converter is connected to the energy storage battery; the second terminal of each first DC-DC converter is connected to the bus through a respective second switch; the second terminal of each first DC-DC converter is connected to the load terminal through a respective switchable device.

[0013] In one embodiment of the present application, the system includes a plurality of the first DC-DC converters, a plurality of the switchable devices, and a plurality of the second switches, and the energy storage battery includes a plurality of energy storage battery clusters, wherein: the first terminal of each first DC-DC converter is respectively connected to an energy storage battery cluster; the second terminal of each first DC-DC converter is connected to the bus through a respective second switch; the second terminal of each first DC-DC converter is connected to the load terminal through a respective switchable device.

[0014] In one embodiment of the present application, the system further includes a plurality of third switches, wherein: the first terminal of each second DC-DC converter is respectively connected to a load terminal through a respective third switch.

[0015] In one embodiment of the present application, the system further includes an AC-DC converter and a transformer, the first terminal of the AC-DC converter is connected to the first terminal of the transformer, the second terminal of the AC-DC converter is connected to the bus, and the second terminal of the transformer is connected to the power grid.

[0016] According to another aspect of the present application, a charging station is provided, and the charging station includes the above-mentioned optical storage charging system.

[0017] The optical storage charging system of the present application can effectively reduce the system cost and volume, and effectively improve the conversion efficiency of the energy storage battery for charging the load terminal. Description of the Drawings

[0018] The above and other objects, features, and advantages of the present application will become more apparent by describing the embodiments of the present application in more detail with reference to the accompanying drawings. The drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0019] Figure 1 The schematic structural diagram of an existing optical storage and charging system is shown.

[0020] Figure 2 The schematic structural diagram of an optical storage and charging system according to an embodiment of the present application is shown.

[0021] Figure 3 The schematic structural diagram of an optical storage and charging system according to another embodiment of the present application is shown.

[0022] Figure 4 The schematic structural diagram of an optical storage and charging system according to still another embodiment of the present application is shown. Detailed implementation manners

[0023] In order to make the objectives, technical solutions, and advantages of the present application more apparent, exemplary embodiments according to the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein. Based on the embodiments of the present application described herein, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0024] Figure 1 The schematic topological structure diagram of the existing optical storage and charging system 100 is shown. As Figure 1As shown, the photovoltaic energy storage charging system 100 includes an AC-DC converter, a bus, photovoltaic modules, energy storage batteries, a first DC-DC converter DC-DC2, a second DC-DC converter DC-DC3, and a third DC-DC converter DC-DC1. Among them, the three-phase alternating current of the power grid is converted into high-voltage direct current through a transformer and AC-DC. The photovoltaic modules are connected to the bus through DC-DC1, the energy storage batteries are connected to the bus through DC-DC2, and loads such as electric vehicles are connected to the bus through DC-DC3. With the rapid development of electric vehicle ultra-fast charging technology, the charging power is getting larger and larger. When the charging power exceeds the grid capacity, energy storage batteries are needed to supplement the energy. When the power grid and energy storage batteries supply energy to the electric vehicle at the same time, the power flowing through DC-DC3 is equal to the sum of the powers of AC-DC and DC-DC2. The rated power of DC-DC3 is also the maximum charging power. Thus, the power of DC-DC3 is very large, the volume of the product is very large, and the cost is very high. Moreover, when the energy storage battery supplies energy to the electric vehicle, it needs to go through two-stage conversions of DC-DC2 and DC-DC3, resulting in large losses and low conversion efficiency. In addition, the energy storage battery is connected to the bus through a DC-DC. As the battery pack decays, the energy storage battery can only be derated as a whole and cannot be utilized to the maximum extent.

[0025] To solve at least one of the above problems, the present application provides a new photovoltaic energy storage charging system. This will be described below with reference to the accompanying drawings.

[0026] Figure 2 The structural schematic diagram of a photovoltaic energy storage charging system 200 according to an embodiment of the present application is shown. As Figure 2 shown, the photovoltaic energy storage charging system 200 includes: a power grid, a bus, photovoltaic modules, energy storage batteries, a first DC-DC converter DC-DC2, a second DC-DC converter DC-DC3, and a switchable device.

[0027] Among them, the bus is connected to the power grid; the first end of the first DC-DC converter DC-DC2 is connected to the energy storage battery, the second end of the first DC-DC converter DC-DC2 is connected to the bus, and the second end of the first DC-DC converter DC-DC2 is connected to the load terminal via a first switch (i.e., Figure 2 the electric vehicle shown in, and the electric vehicle is an example of a load); the first end of the second DC-DC converter DC-DC3 is connected to the load terminal, and the second end of the second DC-DC converter DC-DC3 is connected to the bus.

[0028] In the embodiment of the present application, the energy storage battery is connected to the load terminal via the first DC-DC converter DC-DC2 and then through the switchable device. When the power consumption of the load terminal is too large, the switchable device is closed, and the energy storage battery can charge the load terminal via the first DC-DC converter DC-DC2 without the need toFigure 1 Unlike the energy storage charging system 100 shown, which passes through two levels of DC-DC converters, namely the first DC-DC converter DC-DC2 and the second DC-DC converter DC-DC3, it only needs to pass through the first DC-DC converter DC-DC2 to charge the load terminal. Therefore, the conversion loss can be reduced and the conversion efficiency can be improved. In addition, since the energy storage battery does not need to pass through the second DC-DC converter DC-DC3 like the energy storage charging system 100 shown in Figure 1 , the rated power of the second DC-DC converter DC-DC3 in the energy storage charging system 200 does not need to be very large, which can reduce its volume and manufacturing cost. Therefore, the energy storage charging system 200 according to the embodiment of the present application can effectively reduce the system cost and volume, and effectively improve the conversion efficiency of the energy storage battery to charge the load terminal.

[0029] In a further embodiment of the present application, the energy storage charging system 200 may include a plurality of second DC-DC converters DC-DC3 (not shown in Figure 2 , and will be shown later in Figure 3 and Figure 4 ), where: the first end of each second DC-DC converter DC-DC3 is respectively connected to a load terminal; the second end of each second DC-DC converter DC-DC3 is connected to the bus. In addition, the energy storage charging system 200 further includes a plurality of first switches (not shown in Figure 2 , and will be shown later in Figure 3 and Figure 4 ), where: the respective first ends of two adjacent second DC-DC converters DC-DC3 are connected to each other via a first switch. In this embodiment, at least two second DC-DC converters DC-DC3 can be connected in parallel via the first switch to jointly charge the load terminal, so as to more fully meet the power demand of the load terminal, and the volume of DC-DC3 can be further reduced (because it does not need to be made into a large volume to meet a large power, and a large power can be achieved by connecting multiple DC-DC3 in parallel), thereby further reducing the cost.

[0030] In a further embodiment of the present application, when the first switch connecting two adjacent second DC-DC converters DC-DC3 is closed, the bus supplies power to the load terminal via the two adjacent second DC-DC converters DC-DC3. In a specific embodiment, taking the load terminal as an electric vehicle as an example, it can be that the power grid charges the electric vehicle alone. When one path of the second DC-DC converter DC-DC3 cannot meet the charging power requirement of the electric vehicle, the first switch is closed. At this time, the two adjacent second DC-DC converters DC-DC3 connected by the first switch can charge the electric vehicle simultaneously, so as to meet the power requirement for charging a high-power electric vehicle.

[0031] In a further embodiment of the present application, when the first switch connecting two adjacent second DC-DC converters DC-DC3 is opened and the switchable device is turned on, the energy storage battery supplies power to the load terminal via the first DC-DC converter DC-DC2, and the bus supplies power to the load terminal via the adjacent second DC-DC converter DC-DC3. Taking the load terminal as an electric vehicle as an example, when the energy storage battery and the power grid jointly charge the electric vehicle, the switchable device is turned on, and the energy storage battery charges the electric vehicle through one path of the second DC-DC converter DC-DC2. At the same time, the first switch is opened, and one path of the second DC-DC converter DC-DC3 also charges the electric vehicle. In order to obtain a greater charging power, the first switch can also be closed, so that the two adjacent second DC-DC converters DC-DC3 connected by the first switch charge the electric vehicle simultaneously. The specific power supply method can be selected by combining factors such as the charging power required by the vehicle, the power of the energy storage battery, and the operation mode of peak-valley electricity prices, so as to reduce costs.

[0032] In a further embodiment of the present application, the optical storage charging system 200 may further include a second switch (not shown in Figure 2 , and will be described later in combination with Figure 4 . The second terminal of the first DC-DC converter DC-DC2 is connected to the bus via the second switch. In addition, the optical storage charging system 200 may include a plurality of first DC-DC converters DC-DC2, a plurality of switchable switches, and a plurality of second switches (not shown in Figure 2 , and will be described later in combination with Figure 4(to be described later), where: the first end of each first DC-DC converter DC-DC2 is connected to the energy storage battery; the second end of each first DC-DC converter DC-DC2 is respectively connected to the bus through a second switch; the second end of each first DC-DC converter DC-DC2 is respectively connected to the load terminal through a switchable device. In this embodiment, since the energy storage battery is respectively connected to the bus through multiple DC-DC2s, and each DC-DC2 is respectively connected to one or more load terminals through a first switch, when the performance of one or more of the DC-DC2s deteriorates, the energy storage battery can supply power to the load through other DC-DC2s, which can improve the utilization rate of the energy storage battery.

[0033] In another embodiment of the present application, the optical storage charging system 200 includes a second switch (not shown in Figure 2 and will be described later in combination with Figure 3 ), and the second end of the first DC-DC converter DC-DC2 is connected to the bus through the second switch. In addition, the optical storage charging system 200 includes multiple first DC-DC converters DC-DC2, multiple switchable devices, and multiple second switches. The energy storage battery includes multiple energy storage battery clusters, where: the first end of each first DC-DC converter DC-DC2 is respectively connected to an energy storage battery cluster; the second end of each first DC-DC converter DC-DC2 is respectively connected to the bus through a second switch; the second end of each first DC-DC converter DC-DC2 is respectively connected to the load terminal through a switchable device. Compared with the previous embodiment, the energy storage battery is not only respectively connected to the bus through multiple DC-DC2s, but also the energy storage battery is divided into multiple energy storage battery clusters. When the performance of one energy storage battery cluster deteriorates, it can charge the load terminal through other energy storage battery clusters and their corresponding DC-DC2s and first switches, so as to ensure that the overall function of the energy storage battery is not affected too much and realize the maximum utilization of the energy storage battery.

[0034] In a further embodiment of the present application, the optical storage charging system 200 may further include multiple third switches (not shown in Figure 2 and will be shown later in Figure 3 and Figure 4 ), where the first end of each second DC-DC converter DC-DC3 is respectively connected to a load terminal through a third switch. In this embodiment, through the third switch, the load terminal to be charged can be freely selected, so that multiple DC-DC3s can be connected in parallel to charge a load terminal, thereby providing a greater charging power for the load terminal and meeting the greater charging demand of the load terminal.

[0035] In a further embodiment of the present application, the photovoltaic energy storage charging system 200 further includes an AC-DC converter and a transformer. The first end of the AC-DC converter is connected to the first end of the transformer, the second end of the AC-DC converter is connected to the bus, and the second end of the transformer is connected to the power grid. In addition, the photovoltaic energy storage charging system 200 further includes a photovoltaic module and a third DC-DC converter DC-DC1. The first end of the third DC-DC converter DC-DC1 is connected to the photovoltaic module, and the second end of the third DC-DC converter DC-DC1 is connected to the bus. In the embodiment of the present application, the photovoltaic module of the photovoltaic energy storage charging system 200 (the photovoltaic module can be a solar panel, which is a device that converts light energy into electrical energy. It is mainly composed of photovoltaic cells, which are usually connected in series and parallel to form a complete circuit and can independently generate direct current) converts solar energy into electrical energy, which is connected to the bus through the third DC-DC converter DC-DC1, and supplies power to the energy storage battery and the load terminal through the first DC-DC converter DC-DC2 and the second DC-DC converter DC-DC3 respectively. The external power grid converts the voltage through the transformer and is connected to the bus through the AC-DC converter, and supplies power to the energy storage battery and the load terminal through the first DC-DC converter DC-DC2 and the second DC-DC converter DC-DC3 respectively. The transformer can also be a component of the photovoltaic energy storage charging system 200, or it can be located outside the photovoltaic energy storage charging system 200. In addition, the photovoltaic energy storage charging system 200 may further include a control unit (not shown), which is used to control the opening and closing states of the switches in the photovoltaic energy storage charging system 200 to meet different charging requirements.

[0036] Based on the above description, the photovoltaic energy storage charging system 200 according to the embodiment of the present application can effectively reduce the system cost and volume, and effectively improve the conversion efficiency of the energy storage battery for charging the load terminal.

[0037] The following combines Figure 3 and Figure 4 to describe the more specific structural topology diagrams of the above photovoltaic energy storage charging system 200 in different embodiments.

[0038] Figure 3 FIG. shows a schematic structural diagram of a photovoltaic energy storage charging system 300 according to another embodiment of the present application. As Figure 3As shown in the figure, the photovoltaic energy storage charging system 300 includes: an AC-DC converter, a bus, a photovoltaic module, a third DC-DC converter DC-DC1, a plurality of energy storage battery clusters 1 to n (collectively referred to as energy storage battery clusters), a plurality of first DC-DC converters DC-DCa1 to DC-DCan (collectively referred to as DC-DCa), a plurality of switchable devices km1 to kmn-1 (collectively referred to as switchable device km), a plurality of second switches kj1 to kjn (collectively referred to as second switch kj), a plurality of second DC-DC converters DC-DCb1 to DC-DCbn (collectively referred to as DC-DCb), a plurality of first switches kh1 to khn-1 (collectively referred to as first switch kgh), and a plurality of third switches kg1 to kgn-1 (collectively referred to as third switch kg).

[0039] Among them, the energy storage battery cluster is directly connected to the load terminal through the first DC-DC converter DC-DCa and the corresponding switchable device km; the energy storage battery cluster is directly connected to the bus through the first DC-DC converter DC-DCa and the corresponding second switch kj. When the switchable device km is turned off, the electric energy of the corresponding energy storage battery cluster is converted by the first DC-DC converter DC-DCa to charge the load terminal. The output end of the second DC-DC converter DC-DCb is provided with a first switch kh, and the respective first ends of two adjacent second DC-DC converters DC-DCb are connected to each other via a first switch kh, and the first switch kh connects the plurality of second DC-DC converters DC-DCb in parallel. The input end of the load terminal is provided with a third switch kg, and the first end of each second DC-DC converter DC-DCb is connected to a load terminal through a third switch, and the third switch kg controls the charging condition of the corresponding load terminal.

[0040] When a certain energy storage battery cluster needs to be charged (such as energy storage battery cluster 1), the connected kj switch is closed (such as kj1), and the electric energy of the bus is converted by DC-DC a (such as DC-DC a1) to charge the energy storage battery cluster. The charging path at this time is: bus - Kj1 - DC-DC a1 - energy storage battery cluster 1.

[0041] When a certain energy storage battery cluster needs to charge the load terminal (such as energy storage battery cluster 1), the connected km switch is closed (such as km1), and the electric energy of the energy storage battery cluster is converted by DC-DC (such as DC-DC a1) to charge the load terminal (such as electric vehicle 1). The charging path at this time is: energy storage battery cluster 1 - DC-DC a1 - Km1 - electric vehicle.

[0042] When the power of a single DC-DC b module is less than the charging power requested by the load terminal (such as DC-DC b1), one method is to close multiple Kh switches, and multiple DC-DC b modules are connected in parallel to charge the load terminal together. For example, 3 DC-DC b modules are required to meet the power demand of charging pile 1. Kh1 and Kh2 are closed, and DC-DC b1, DC-DC b2, and DC-DC b3 are connected in parallel to charge the load terminal.

[0043] When the power of a single DC-DC b module is less than the charging power requested by the load terminal (such as DC-DC b1), another method is to close the km switch, and the energy storage battery cluster supplies electric energy to the load terminal. For example, the DC-DC b module and a group of energy storage battery clusters are required to meet the power demand of charging pile 1. Km1 is closed, and DC-DCb1 and energy storage battery cluster 1 charge the load terminal together.

[0044] When the power of a single DC-DC b module is less than the charging power requested by the load terminal (such as DC-DC b1), another method is to close the km and kh switches, including closing 1 km switch and 1 kh switch, closing multiple km switches and 1 kh switch, closing 1 km switch and multiple kh switches, and closing multiple km switches and multiple kh switches. For example, when km1, km2, and kh1 are closed, energy storage battery cluster 1, energy storage battery cluster 2, DC-DC b1, and DC-DC b2 charge the load terminal together.

[0045] In an embodiment of the present application, a control unit is further added, which is used to control the opening and closing states of each switching unit to achieve precise control over the charging and discharging of the energy storage battery cluster and the charging of the load terminal. The control unit is a centralized control center that precisely controls the opening and closing states of all switching elements, such as the first, second, and third switches and the switchable devices, by detecting the working states of each component and according to a preset control algorithm. Specifically, the control unit needs to collect real-time data as follows: the power generation of the photovoltaic modules, the power supply from the power grid, the power, voltage, temperature, and other parameters of each energy storage battery cluster, the input and output power of each boost converter, and the real-time power demand of the load terminal. Based on this data, the control unit will calculate the optimal power supply mode and path according to the built-in control algorithm and issue corresponding switch control instructions to automatically achieve: the recharge management of the storage cluster, the seamless switching power supply between the photovoltaic / grid and the energy storage cluster / load, the single or parallel operation mode of the DC-DC converter, and the coordinated combination of the energy storage battery cluster and the converter output. The optimization of the control algorithm is the key to the control unit, and it is necessary to balance parameters such as energy loss, battery aging, component efficiency, and load response time to seek the overall optimal control strategy. The control unit runs through the entire optical storage system, and its automation level directly determines the efficient operation of the system. With the continuous innovation of control technology, the system will also exhibit more performance advantages and application potential.

[0046] In the embodiments of the present application, a single energy storage battery cluster corresponds to a single second switch kj. When the input of a single energy storage battery cluster is lower than the current output of the bus, at least one second switch kj is turned off so that the energy storage battery cluster meets the current input demand. The single energy storage battery cluster is connected to the bus through the second switch kj. The control unit monitors the working state of each energy storage battery cluster in real time, including the remaining power, voltage, temperature, etc., and calculates the current available output power of the energy storage battery cluster according to these parameters. At the same time, the control unit also monitors the current total power demand of the bus. When the available output power of a certain storage cluster is lower than the current output of the bus, the control unit will issue an instruction to turn off the second switch kj corresponding to the cluster and cut off its connection with the bus. This can avoid the adverse impact of the low-power cluster on the power output of the bus. On the contrary, for other storage clusters with available output power above, the control unit keeps their second switches kj in the off state and starts to continuously provide power output to the bus. Through this dynamic connection control strategy, it can be ensured that the energy storage battery clusters connected to the bus are always in a high power output state, thus meeting the power demand of the system operation and improving the utilization efficiency of electric energy. In addition, this control strategy is adjusted according to the requirements of different working modes. For example, in the system remaining mode, the energy storage battery cluster with the highest aging degree can be preferentially cut off to extend the remaining life; in the charging mode, the energy storage battery cluster with a lower bottom layer can be preferentially connected to achieve equal charging. The realization of refined module management of the energy storage battery clusters not only improves the reliability and reset of the system, but also maximizes the performance potential of the energy storage battery clusters and realizes the efficient utilization of battery resources.

[0047] In an embodiment of the present application, when the output power of the second DC-DC converter DC-DCb is less than the current charging power demand of the load terminal, multiple first switches kh can be turned off to achieve parallel output of multiple second DC-DC converters DC-DCb for charging the load terminal. Multiple third switches kg are also provided at the input end of the load terminal, and the output end of each second DC-DC converter DC-DCb is connected to the load terminal through a corresponding third switch kg. The control unit monitors the current charging power demand of the load terminal in real time and compares the demand value with the rated output power of a single second DC-DC converter DC-DCb. Once it is detected that the output power of the converter meets the current demand, the control unit first calculates and determines the number of second DC-DC converters DC-DCb that need to be paralleled. At the same time, it issues an instruction to turn off the corresponding number of first switches kh, so that the output ends of the second DC-DC converters DC-DCb are paralleled together. At the same time, for these paralleled second DC-DC converters DC-DCb, the control unit also turns off the corresponding third switches kg respectively, and only one switch remains in the on state as a connection supplement to the load terminal for parallel output. This strategy can dynamically adjust the number of paralleled converters, thereby providing sufficient total output power, avoiding inefficient use of energy and conversion loss. At the same time, separately controlling the third switches kg is also beneficial to controlling the current distribution of parallel output and preventing individual overload. In addition to meeting the high-power load demand, this parallel design drawing is used in low-power scenarios to improve efficiency by paralleling a small number of individual converters. For example, in the case of low power, paralleling 2 for parallel operation can reduce the load efficiency and avoid the inefficient operation of a large-power converter with a single one. For the optimization of the parallel control strategy, advanced control schemes such as an active parallel algorithm based on load power prediction and a hybrid parallel mode that takes into account both efficiency and reliability can be explored in the future to improve the flexibility of the system and further utilization rate of energy. In short, this parallel output design fully demonstrates the customization and customization concept of this optical storage system in power conversion and efficient load response, can adapt to changes in power demand under different working conditions, and shows great application potential.

[0048] In an embodiment of the present application, when the output power of a single second DC-DC converter DC-DCb is less than the current charging power demand of the load terminal, the corresponding switchable device km can be turned off to enable the corresponding energy storage battery cluster to charge the load terminal through the corresponding first DC-DC converter DC-DCa. The control unit monitors the output power of each second DC-DC converter DC-DCb in real time and compares it with the current charging power demand of the load terminal. Once it is found that the output power of a certain second DC-DC converter DC-DCb meets the demand, the control unit will execute according to the following several strategies: determine whether there are other second DC-DC converters DC-DCb in parallel. If so, start multiple second DC-DC converters DC-DCb to output in parallel according to the third parallel strategy. If the total power after parallel connection is still insufficient, or there are no other second DC-DC converters DC-DCb that can be paralleled, the control unit will check the current state of the energy storage battery cluster. Calculate the available output power of each cluster based on parameters such as the remaining capacity, voltage, and temperature of each energy storage battery cluster. Select one or more energy storage battery clusters with the highest available output power, switch to the power supply mode by turning off the corresponding switchable device km. At the same time, start the first DC-DC converters DC-DCa of these clusters as the connection corresponding to the energy storage battery cluster and the load terminal. So many power sources can supply power to the load in parallel at the same time, and the combined total output power can meet the current demand. Based on the principle of "converter first, battery assistance", first use the parallel converters to provide the main output power, and supplement the battery output when there is a shortage, giving full play to the advantages of the two power sources. In addition to the basic strategy, further optimization of the future state of the control algorithm, such as predicting the power demand curve to achieve active switching, the above output based on battery health allocation, etc., to further improve the energy utilization efficiency of the system and the battery cycle life. In short, this backup battery power supply design not only provides backup energy for the system, but also realizes seamless switching of multiple efficient power supply modes, can cope with various workload scenarios, and is the guarantee for improving the flexibility and reliability of the overall system.

[0049] In an embodiment of the present application, when the output power of a single second DC-DC converter DC-DCb is lower than the current charging power demand of the load terminal, at least one switchable device km and at least one first switch kh can be turned off, so that an energy storage battery cluster charges the load terminal through the corresponding first DC-DC converter DC-DCa and two parallel second DC-DC converters DC-DCb. The control unit monitors the power state of the entire system at all times, including the output power of each power supply terminal, the power demand of the load terminal, etc. Once it is found that the total output of a single or parallel second DC-DC converter DC-DCb still cannot meet the charging power demand of the current load, the control unit will execute the following hybrid parallel power supply strategy: according to the current state of the energy storage battery cluster, select one or more energy storage battery clusters corresponding to the available output power. Turn off the switchable devices km corresponding to these energy storage battery clusters to cut off their connection to the load. At the same time, start the corresponding first DC-DC converter DC-DCa and connect it to the output terminal of the already parallel second DC-DC converter DC-DCb. The control unit will reasonably distribute the output current of the two paths to supply power to the load terminal. If the sum of the two paths of power is still insufficient, the number of second DC-DC converters DC-DCb and the number of energy storage battery clusters that are connected in parallel will continue to be increased until the demand is met.

[0050] Based on the above description, the optical storage charging system 300 according to the embodiment of the present application can effectively reduce the system cost and volume, effectively improve the conversion efficiency of the energy storage battery for charging the load terminal, and can also maximize the utilization of the energy storage battery.

[0051] Figure 4 The structural schematic diagram of an optical storage charging system 400 according to another embodiment of the present application is shown. Figure 4 Similar to Figure 3 in general, the difference is that Figure 4 the energy storage battery is not divided into multiple energy storage battery clusters. Compared with the Figure 3 embodiment shown, the cost can be reduced, which is applicable to the scenario where the power demand of the load terminal is not too large. Figure 4 Other content in Figure 3 is similar to that in

[0052] For the sake of brevity, it will not be elaborated here. According to another aspect of the present application, a charging station is also provided, and the charging station includes the above-mentioned optical storage charging system. The optical storage charging system of the present application has been described in detail above, and those skilled in the art can understand its structure and principle in combination with the foregoing. For the sake of brevity, it will not be elaborated here.

[0053] Based on the above description, the optical storage charging system according to the embodiments of the present application can effectively reduce the system cost and volume, effectively improve the conversion efficiency of the energy storage battery for charging the load terminal, and also maximize the utilization of the energy storage battery.

[0054] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0055] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0056] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0057] In the specification provided herein, a large number of specific details are set forth. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and technologies have not been shown in detail so as not to obscure the understanding of this specification.

[0058] Similarly, it should be understood that, in order to streamline the present application and assist in understanding one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be construed as reflecting the intention that the claimed present application requires more features than are expressly recited in each claim. Rather, as reflected by the corresponding claims, the inventive point lies in that the corresponding technical problems can be solved by features less than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present application.

[0059] Those skilled in the art will appreciate that, except where features are mutually exclusive, any combination can be employed to combine all the features disclosed in this specification (including the accompanying claims, abstract, and drawings), as well as all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0060] In addition, those skilled in the art will understand that, although some of the embodiments described herein include certain features included in other embodiments but not others, combinations of features of different embodiments are meant to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0061] Each component embodiment of this application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some of the modules according to the embodiments of this application. This application can also be implemented as a program (e.g., a computer program and a computer program product) for performing part or all of the methods described herein. Such a program implementing this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or in any other form.

[0062] It should be noted that the above embodiments illustrate rather than limit this application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several vehicle-mounted refrigerator control devices, several of these vehicle-mounted refrigerator control devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0063] As described above, it is only the specific implementation manner of this application or the description of the specific implementation manner. The protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. The protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A solar storage and charging system, characterized in that: The system comprises a power grid, a busbar, an energy storage battery, a first DC-to-DC converter, a second DC-to-DC converter and a switchable device, wherein: The busbar is connected to the power grid; A first end of the first DC-to-DC converter is connected to the energy storage battery, a second end of the first DC-to-DC converter is connected to the bus, and a second end of the first DC-to-DC converter is connected to a load terminal via the switchable device; A first end of the second DC-to-DC converter is connected to the load terminal, and a second end of the second DC-to-DC converter is connected to the bus.

2. The system according to claim 1, characterized in that The system comprises a plurality of the second DC-DC converters, wherein: The first end of each of the second DC-DC converters is respectively connected to one of the load terminals; The second end of each of the second DC-to-DC converters is connected to the bus.

3. The system according to claim 2, characterized in that The system further comprises a plurality of first switches, wherein: The first ends of two adjacent second DC-to-DC converters are connected to each other via one first switch.

4. The system according to claim 3, characterized in that When the first switch connecting two adjacent second DC-to-DC converters is closed, the bus supplies power to the load terminal via the two adjacent second DC-to-DC converters.

5. The system according to claim 3, characterized in that When the first switch connecting two adjacent second DC-to-DC converters is disconnected and the switchable device is turned on, the energy storage battery supplies power to the load terminal via the first DC-to-DC converter, and the busbar supplies power to the load terminal via the adjacent second DC-to-DC converter.

6. The system according to claim 1, characterized in that The system further includes a second switch, and the second end of the first DC-to-DC converter is connected to the bus via the second switch.

7. The system according to claim 6, characterized in that The system comprises a plurality of the first DC-DC converters, a plurality of the switchable devices and a plurality of the second switches, wherein: The first end of each of the first DC-to-DC converters is connected to the energy storage battery; The second end of each of the first DC-DC converters is connected to the busbar via a second switch; The second end of each of the first DC-to-DC converters is connected to the load terminal via one of the switchable devices.

8. The system according to claim 6, characterized in that The system comprises a plurality of the first DC-DC converters, a plurality of the switchable devices and a plurality of the second switches, and the energy storage battery comprises a plurality of energy storage battery clusters, wherein: The first end of each of the first DC-DC converters is respectively connected to one of the energy storage battery clusters; The second end of each of the first DC-DC converters is connected to the busbar via a second switch; The second end of each of the first DC-to-DC converters is connected to the load terminal via one of the switchable devices.

9. The system according to claim 1, characterized in that The system further comprises a plurality of third switches, wherein: The first end of each of the second DC-to-DC converters is connected to one of the load terminals via one of the third switches.

10. The system according to claim 1, characterized in that The system further comprises an AC-to-DC converter and a transformer, wherein a first end of the AC-to-DC converter is connected to a first end of the transformer, a second end of the AC-to-DC converter is connected to the bus, and a second end of the transformer is connected to a power grid.

11. The system according to claim 1, characterized in that The system also includes a photovoltaic component and a third DC-to-DC converter, wherein a first end of the third DC-to-DC converter is connected to the photovoltaic component, and a second end of the third DC-to-DC converter is connected to the busbar.

12. A charging station, characterized in that: The charging station comprises the solar storage and charging system according to any one of claims 1 to 11.

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