Energy storage system and vehicle

Abstract

The utility model discloses an energy storage system and a vehicle. The energy storage system comprises a CLLC circuit; the full-bridge rectifying circuit is connected with the CLLC circuit; the battery is electrically connected with the full-bridge rectifier circuit; the photovoltaic power supply unit is connected with the CLLC circuit and the full-bridge rectification circuit; and the low-voltage output unit is connected with the CLLC circuit and the full-bridge rectification circuit. According to the energy storage system and the vehicle, the utilization rate of devices can be increased, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage devices, and more specifically to an energy storage system and a vehicle. Background Art

[0002] In order to achieve multiple types of energy input and multiple voltage output, current energy storage systems usually design multiple energy transmission branches in parallel, without considering the device reuse between these branches, resulting in low device utilization and high product cost.

[0003] For example, when the energy storage system adds photovoltaic input and low-voltage output functions, the traditional solution is to connect a Boost circuit in parallel at both ends of the energy storage battery to boost the voltage output by the photovoltaic panel. At the same time, a Buck circuit is connected in parallel at both ends of the energy storage battery to reduce the voltage of the energy storage battery according to the output voltage requirement. This solution of parallel Boost circuit and Buck circuit has low device utilization and high product cost.

[0004] Therefore, improvements are needed to at least partially solve the above problems. Utility Model Content

[0005] A series of simplified concepts are introduced in the utility model content section, which will be further described in detail in the detailed implementation section. The utility model content section of the utility model does not mean to attempt to define the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0006] In order to at least partially solve the above problems, according to a first aspect of the present utility model, an energy storage system is provided, comprising:

[0007] CLLC circuit;

[0008] A full-bridge rectifier circuit connected to the CLLC circuit;

[0009] a battery, electrically connected to the full-bridge rectifier circuit;

[0010] A photovoltaic power supply unit connected to the CLLC circuit and the full-bridge rectifier circuit;

[0011] A low voltage output unit is connected to the CLLC circuit and the full-bridge rectifier circuit.

[0012] Exemplarily, the full-bridge rectifier circuit includes a first bridge arm and a second bridge arm, and the CLLC circuit includes a first inductor, a transformer and a first switch;

[0013] Two ends of the first bridge arm are electrically connected to two ends of the battery, and a midpoint of the first bridge arm is electrically connected to a first end of the first inductor;

[0014] Two ends of the second bridge arm are electrically connected to two ends of the battery, and a midpoint of the second bridge arm is electrically connected to a first end of a winding on one side of the transformer;

[0015] The second end of the first inductor is electrically connected to the second end of the winding;

[0016] The first switch is arranged between the second end of the first inductor and the second end of the winding, or between the midpoint of the second bridge arm and the first end of the winding.

[0017] Exemplarily, the photovoltaic power supply unit includes a photovoltaic panel and a second switch;

[0018] The first end of the photovoltaic panel is electrically connected to the second end of the first inductor through the second switch, and the second end of the photovoltaic panel is electrically connected to one end of the first bridge arm.

[0019] Exemplarily, the low-voltage output unit includes a low-voltage output module and a third switch, wherein the low-voltage output module includes a battery and / or a load;

[0020] The first end of the low-voltage output module is electrically connected to the second end of the first inductor through the third switch, and the second end of the low-voltage output module is electrically connected to one end of the first bridge arm.

[0021] Exemplarily, the full-bridge rectifier circuit includes a first bridge arm and a second bridge arm, and the CLLC circuit includes a first inductor, a second inductor, a transformer, a first switch, and a second switch;

[0022] Two ends of the first bridge arm are electrically connected to two ends of the battery, and a midpoint of the first bridge arm is electrically connected to a first end of the first inductor;

[0023] Two ends of the second bridge arm are electrically connected to two ends of the battery, and a midpoint of the second bridge arm is electrically connected to a first end of the second inductor;

[0024] The second end of the first inductor is electrically connected to the first end of the winding on one side of the transformer through the first switch;

[0025] The second end of the second inductor is electrically connected to the second end of the winding through the second switch.

[0026] Exemplarily, the photovoltaic power supply unit includes a photovoltaic panel and a third switch;

[0027] The first end of the photovoltaic panel is electrically connected to the second end of the first inductor through the third switch, and the second end of the photovoltaic panel is electrically connected to one end of the first bridge arm.

[0028] Exemplarily, the low-voltage output unit includes a low-voltage output module and a fourth switch, wherein the low-voltage output module includes a battery and / or a load;

[0029] The first end of the low voltage output unit is electrically connected to the second end of the second inductor through the fourth switch, and the second end of the low voltage output module is electrically connected to one end of the second bridge arm.

[0030] Exemplarily, the CLLC circuit includes a first inductor, a second inductor, a transformer, a first switch and a second switch, and the full-bridge rectifier circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first capacitor and a third switch;

[0031] The first end of the first switch tube is electrically connected to the first end of the battery, the second end of the first switch tube is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the first end of the second switch tube, the second end of the second switch tube is electrically connected to the second end of the battery, and the third switch is connected in parallel to both ends of the first capacitor;

[0032] The first end of the third switch tube is electrically connected to the first end of the battery, the second end of the third switch tube is electrically connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is electrically connected to the second end of the battery;

[0033] The first end of the first inductor is electrically connected to the first end of the second switch tube, the second end of the first inductor is electrically connected to the first end of the first switch, the second end of the first switch is electrically connected to the first end of the winding on one side of the transformer, the third end of the first switch is electrically connected to the first end of the photovoltaic power supply unit, and the second end of the photovoltaic power supply unit is electrically connected to the second end of the second switch tube, wherein the first switch can selectively conduct its first end and the second end, or conduct its first end and the third end;

[0034] The first end of the second inductor is electrically connected to the second end of the third switch tube, the second end of the second inductor is electrically connected to the first end of the second switch, the second end of the second switch is electrically connected to the second end of the winding, and the third end of the second switch is electrically connected to the second end of the third switch tube, wherein the second switch can selectively turn on its first end and the second end, or turn on its first end and the third end.

[0035] Exemplarily, the low-voltage output unit includes a low-voltage output module and a fourth switch, wherein the low-voltage output module includes a battery and / or a load;

[0036] The first end of the low voltage output module is electrically connected to the second end of the second inductor through the fourth switch, and the second end of the low voltage output module is electrically connected to the first end of the third switch tube or the second end of the fourth switch tube.

[0037] Exemplarily, the energy storage system further includes a power factor correction circuit and a full-bridge inverter circuit, wherein the power factor correction circuit is connected to the full-bridge inverter circuit, and the full-bridge inverter circuit is connected to the CLLC circuit.

[0038] According to a second aspect of the present utility model, a vehicle is provided, which comprises the energy storage system as described above.

[0039] According to the energy storage system and vehicle of the utility model, by connecting the photovoltaic power supply unit and the low-voltage output unit to the CLLC circuit and the full-bridge rectifier circuit at the same time, the inductor in the CLLC circuit and the bridge arm in the full-bridge rectifier circuit can be reused to form a buck-boost circuit to achieve the boost of the photovoltaic power supply and the buck of the energy storage battery, without the need to additionally configure the Boost circuit and the Buck circuit, thereby significantly improving the device utilization rate and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The following drawings of the present application are hereby used as part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, and are used to explain the device and principle of the present application. In the drawings,

[0041] Figure 1 is a schematic structural block diagram of an energy storage system according to an embodiment of the present application;

[0042] Figure 2 is a schematic circuit diagram of an energy storage system according to an embodiment of the present application;

[0043] Figure 3 for Figure 2 A simplified schematic diagram of the energy storage system in the example of photovoltaic charging;

[0044] Figure 4 for Figure 2 A simplified schematic diagram of the energy storage system in the example of low voltage output;

[0045] Figure 5 for Figure 2 Schematic diagram of the working process of the energy storage system;

[0046] Figure 6 is a schematic partial circuit diagram of an energy storage system according to an embodiment of the present application;

[0047] Figure 7 is a schematic partial circuit diagram of an energy storage system according to an embodiment of the present application;

[0048] Figure 8 for Figure 7 A circuit diagram of the energy storage system in the case where the first switch and the second switch are both closed to contact ② and the third switch is open;

[0049] Fig. 9 for Figure 8 Schematic diagram of equivalent deformation of the circuit in;

[0050] Fig.10 for Figure 7 Schematic diagram of the working process of the energy storage system.

[0051] Description of reference numerals:

[0052] 100-power factor correction circuit, 200-DC-DC conversion circuit, 210-full-bridge inverter circuit, 220-CLLC circuit, 220'-CLLC circuit, 220"-CLLC circuit, 230-full-bridge rectifier circuit, 230'-full-bridge rectifier circuit, 230"-full-bridge rectifier circuit, 300-battery, 400-photovoltaic power supply unit, 410-photovoltaic panel, 500-low-voltage output unit, 510-low-voltage output module. DETAILED DESCRIPTION

[0053] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0054] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present application to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0055] It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as a second element, component, region, layer or part.

[0056] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used herein for convenience of description to describe the relationship of one element or feature to other elements or features shown in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation shown in the figures.

[0057] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0058] See attached Figure 1 An energy storage system according to an embodiment of the present application is exemplarily described. The energy storage system may be an energy storage system on a vehicle or other electrical equipment, and includes a power factor correction (PFC) circuit 100, a DC-DC conversion circuit 200, a battery 300, a photovoltaic power supply unit 400, and a low voltage output unit 500.

[0059] A first end of the power factor correction circuit 100 is electrically connected to the AC charging port, and a second end of the power factor correction circuit 100 is electrically connected to a first end of the DC-DC conversion circuit 200. The power factor correction circuit 100 is used to perform power factor correction on the AC power input to the AC charging port.

[0060] The second end of the DC-DC conversion circuit 200 is electrically connected to the battery 300, and is used to convert the voltage of the direct current output by the power factor correction circuit 100 to provide it to the battery 300 to charge the battery 300. The DC-DC conversion circuit 200 includes a full-bridge inverter circuit 210 connected to the power factor correction circuit 100, a CLLC (capacitor-inductor-inductor-capacitor, capacitor-inductor-inductor-capacitor) circuit 220 connected to the full-bridge inverter circuit 210, and a full-bridge rectifier circuit 230 electrically connected to the CLLC circuit 220. Among them, the CLLC circuit 220 includes a transformer and inductors and capacitors on both sides thereof, and the full-bridge rectifier circuit 230 includes two bridge arms.

[0061] The battery 300 is electrically connected to the full-bridge rectifier circuit 230. Thus, the AC power supply can be received through the power factor correction circuit 100 and the DC-DC conversion circuit 200, and converted into DC power to charge the battery 300. Exemplarily, the battery 300 can be a power battery or an energy storage battery on the vehicle.

[0062] The photovoltaic power supply unit 400 is connected to the CLLC circuit 220 and the full-bridge rectifier circuit 230. Thus, the inductor in the CLLC circuit 220 and the bridge arm in the full-bridge rectifier circuit 230 can be reused to form a boost circuit to boost the direct current output by the photovoltaic power supply unit 400 to provide it to the battery 300 to charge the battery 300. Exemplarily, the photovoltaic power supply unit 400 includes a photovoltaic panel.

[0063] The low voltage output unit 500 is connected to the CLLC circuit 220 and the full bridge rectifier circuit 230. Thus, the inductor in the CLLC circuit 220 and the bridge arm in the full bridge rectifier circuit 230 can be reused to form a step-down circuit to step down the DC power output by the battery 300 to provide it to the low voltage output unit 500 and power the low voltage output unit 500. Exemplarily, the low voltage output unit 500 may include a battery and / or a load, and the load may be a low voltage electrical device on a vehicle.

[0064] According to the energy storage system of this embodiment, the inductor in the CLLC circuit 220 and the bridge arm in the full-bridge rectifier circuit 230 can be reused to form a buck-boost circuit to achieve the boost of photovoltaic power supply and the buck of the battery 300, without the need to additionally configure the Boost circuit and the Buck circuit, thereby significantly improving the device utilization and reducing costs.

[0065] See attached Figure 2 In one embodiment of the present application, the power factor correction circuit 100 is a three-phase power factor correction circuit, which includes three inductors (inductor Lr1, inductor Lr2 and inductor Lr3) and three bridge arms arranged in parallel (a bridge arm composed of a switch tube Q1 and a switch tube Q2 arranged in series, a bridge arm composed of a switch tube Q3 and a switch tube Q4 arranged in series, and a bridge arm composed of a switch tube Q5 and a switch tube Q6 arranged in series). The first ends of the three inductors are respectively electrically connected to the three live wire terminals in the AC charging port, and the three live wire terminals are respectively used to connect the first phase live wire L1, the second phase live wire L2 and the third phase live wire L3. The second ends of the three inductors are respectively electrically connected to the midpoints of the three bridge arms. One end of the three bridge arms is also electrically connected to the N line terminal in the AC charging port, and the N line terminal is used to connect the N line. In some other embodiments, the power factor correction circuit 100 can be a single-phase power factor correction circuit.

[0066] The full-bridge rectifier circuit 230 includes a first bridge arm and a second bridge arm, the CLLC circuit 220 includes a first inductor L1, a transformer, a first switch K1, a capacitor C1, an inductor L4, a capacitor C4 and an excitation inductor Lm, and the full-bridge inverter circuit 210 includes a third bridge arm and a fourth bridge arm.

[0067] The first bridge arm includes a first switch tube S1 and a second switch tube S2 arranged in series, the two ends of the first bridge arm are electrically connected to the two ends of the battery 300, and the midpoint of the first bridge arm is electrically connected to the first end of the first inductor L1. The second bridge arm includes a third switch tube S3 and a fourth switch tube S4 arranged in series, the two ends of the second bridge arm are electrically connected to the two ends of the battery 300, and the midpoint of the second bridge arm is electrically connected to the first end of the winding on the first side of the transformer T1. The second end of the first inductor L1 is electrically connected to the second end of the winding through the capacitor C1 and the first switch K1 arranged in series. In some other embodiments, the first switch K1 can be arranged between the midpoint of the second bridge arm and the first end of the winding on the first side of the transformer T1. In some other embodiments, the capacitor C1 can be arranged between the midpoint of the second bridge arm and the first end of the winding. The first switch K1 can be a relay or a switch tube.

[0068] The third bridge arm includes a switch tube Q7 and a switch tube Q8 arranged in series, the two ends of the third bridge arm are electrically connected to the two ends of the bridge arm in the power factor correction circuit 100, and the midpoint of the third bridge arm is electrically connected to the first end of the inductor L4. The fourth bridge arm includes a switch tube Q9 and a switch tube Q10 arranged in series, the two ends of the fourth bridge arm are electrically connected to the two ends of the third bridge arm, and the midpoint of the fourth bridge arm is electrically connected to the first end of the winding on the second side of the transformer T1. The second end of the inductor L4 is electrically connected to the second end of the winding on the second side of the transformer T1 through the capacitor C4, and the two ends of the excitation inductor Lm are electrically connected to the two ends of the winding on the second side of the transformer T1.

[0069] Among them, the values ​​of the first inductor L1, the capacitor C1, the inductor L4 and the capacitor C4 must satisfy:

[0070]

[0071] Wherein fs is the resonant frequency of the CLLC circuit 220, which is also the operating frequency of the aforementioned full-bridge inverter circuit 210. Operating at this frequency allows the CLLC circuit 220 to maintain high efficiency.

[0072] The photovoltaic power supply unit 400 includes a photovoltaic panel 410 and a second switch K2, wherein the first end of the photovoltaic panel 410 is electrically connected to the second end of the first inductor L1 through the second switch K2, and the second end of the photovoltaic panel 410 is electrically connected to one end of the first bridge arm (i.e., to one end of the switch tube S2 and the battery 300). The second switch K2 may be a relay or a switch tube.

[0073] The low voltage output unit 500 includes a low voltage output module 510 and a third switch K3. The low voltage output module 510 includes a battery and / or a load, a first end of the low voltage output module 510 is electrically connected to a second end of the first inductor L1 through the third switch K3, and a second end of the low voltage output module 510 is electrically connected to one end of the first bridge arm (that is, to the switch tube S2 and one end of the battery 300). The third switch K3 can be a relay or a switch tube.

[0074] When the first switch K1 is closed, and the second switch K2 and the third switch K3 are opened, the mains electricity charges the battery 300. Figure 2 At this time, the city power is provided to the battery 300 through the power factor correction circuit 100 and the DC-DC conversion circuit 200 to charge the battery 300.

[0075] When the second switch K2 is closed and the first switch K1 and the third switch K3 are opened, the photovoltaic power supply unit 400 charges the battery 300. Figure 2 At this time, the photovoltaic panel 410 is connected to the battery 300 through the first inductor L1, the first switch tube S1 and the second switch tube S2. The simplified circuit is as follows Figure 3 As shown, the first inductor L1, the first switch tube S1 and the second switch tube S2 form a Boost circuit. The driving signals of the first switch tube S1 and the second switch tube S2 are complementary. The Boost function can be realized by changing the duty cycle of the driving signal to increase the voltage output by the photovoltaic panel 410.

[0076] When the third switch K3 is closed and the first switch K1 and the second switch K2 are opened, the battery 300 supplies power to the low voltage output module 510. Figure 2 As shown by the green arrow in FIG. 3 . At this time, the battery 300 is connected to the low voltage output module 510 through the first inductor L1, the first switch tube S1 and the second switch tube S2. The simplified circuit is as follows Figure 4 The first inductor L1, the first switch tube S1 and the second switch tube S2 form a Buck circuit, the driving signals of the first switch tube S1 and the second switch tube S2 are complementary, and the Buck function can be realized by changing the duty cycle of the driving signal to reduce the voltage of the DC power output by the battery 300.

[0077] After adopting the energy storage system of this embodiment, there is no need to add additional Boost circuits and Buck circuits. The photovoltaic injection and low-voltage output transformation functions can be achieved by simply switching the connection mode of the original devices.

[0078] See attached Figure 5 , the working process of the energy storage system of this embodiment is as follows:

[0079] Step 1: All components of the energy storage system are initialized and enter the self-inspection stage before work;

[0080] Step 2: The energy storage system detects the remaining SOC (State of Charge) of the battery 300 during the self-checking stage and the entire operation, and determines whether the remaining SOC is greater than 5%. If it is not greater than 5%, the energy storage device turns off the low-voltage output function. At the same time, the user chooses whether the energy storage system uses mains power or photovoltaic power replenishment, and enters the third step. If it is greater than 5%, it enters the fourth step.

[0081] Step 3: If the user chooses to use the mains to replenish energy, the first switch K1 is closed, and the second switch K2 and the third switch K3 are disconnected. The system configures parameters according to the normal isolated DCDC working mode, and energy flows from the power grid to the battery 300. If the user chooses photovoltaic replenishment, the second switch K2 is closed, and the first switch K1 and the third switch K3 are disconnected. Configure the complementary synchronous drive mode of the first switch tube S1 and the second switch tube S2, adjust the duty cycle of the drive signal of the first switch tube S1 and the second switch tube S2, and complete the corresponding Boost boost requirement.

[0082] Step 4: When the user needs the low-voltage output function, the third switch K3 is manually closed, the first switch K1 is correspondingly disconnected, and the second switch K2 can be disconnected according to the user's choice. The complementary synchronous driving mode of the third switch tube S3 and the fourth switch tube S4 is configured, and the duty cycle of the driving signal of the third switch tube S3 and the fourth switch tube S4 is adjusted to complete the Buck voltage reduction requirement of the battery 300.

[0083] Step 5: Feedback the remaining SOC of the battery 300 through the host computer. If the remaining SOC drops to 5%, the energy storage device disconnects K3 and prompts the user to replenish energy, and returns to the second step.

[0084] Refer to the attached Figure 7 An energy storage system of another embodiment of the present application is exemplarily described. The energy storage system includes a power factor correction circuit (not shown in the figure), a DC-DC conversion circuit, a battery 300, a photovoltaic power supply unit and a low-voltage output unit. The DC-DC conversion circuit includes a full-bridge inverter circuit (not shown in the figure), a CLLC circuit 220' and a full-bridge rectifier circuit 230'. The power factor correction circuit and the full-bridge inverter circuit are the same as the power factor correction circuit 100 and the full-bridge inverter circuit 210 of the above embodiment, and will not be repeated here.

[0085] The full-bridge rectifier circuit 230' includes a first bridge arm and a second bridge arm, and the CLLC220' includes a first inductor L1, a second inductor, a transformer T1, a first switch K1, a second switch K2, an inductor L4 (not shown in the figure), a capacitor C4 (not shown in the figure) and an excitation inductor Lm (not shown in the figure).

[0086] The first bridge arm includes a first switch tube S1 and a second switch tube S2 arranged in series, the two ends of the first bridge arm are electrically connected to the two ends of the battery 300, and the midpoint of the first bridge arm is electrically connected to the first end of the first inductor L1. The second bridge arm includes a third switch tube S3 and a fourth switch tube S4 arranged in series, the two ends of the second bridge arm are electrically connected to the two ends of the battery 300, and the midpoint of the second bridge arm is electrically connected to the first end of the second inductor L2. The second end of the first inductor L1 is electrically connected to the first end of the winding on the first side of the transformer T1 through the capacitor C1 and the first switch K1 arranged in series, and the second end of the second inductor L2 is electrically connected to the second end of the winding on the first side of the transformer T1 through the second switch K2. In some other embodiments, the capacitor C1 can be arranged between the second end of the second inductor L2 and the second end of the winding. The first switch K1 and the second switch K2 can be relays or switch tubes.

[0087] The connection mode of the inductor L4, the capacitor C4 and the excitation inductor Lm with the full-bridge inverter circuit and the transformer T1 is the same as that in the above embodiment, and will not be repeated here.

[0088] The photovoltaic power supply unit includes a photovoltaic panel 410 and a third switch K3, wherein the first end of the photovoltaic panel 410 is electrically connected to the second end of the first inductor L1 through the third switch K3, and the second end of the photovoltaic panel 410 is electrically connected to one end of the first bridge arm (i.e., to one end of the switch tube S2 and the battery 300). The third switch K3 may be a relay or a switch tube.

[0089] The low voltage output unit includes a low voltage output module 510 and a fourth switch K4. The low voltage output module 510 includes a battery and / or a load, a first end of the low voltage output module 510 is electrically connected to a second end of the second inductor L2 through the fourth switch K4, and a second end of the low voltage output module 510 is electrically connected to one end of the second bridge arm (that is, to the switch tube S4 and one end of the battery 300). The fourth switch K4 can be a relay or a switch tube.

[0090] When the first switch K1 and the second switch K2 are closed, and the third switch K3 and the fourth switch K4 are opened, the mains electricity charges the battery 300. Figure 7 At this time, the city power is provided to the battery 300 through the power factor correction circuit and the DC-DC conversion circuit to charge the battery 300.

[0091] When the third switch K3 is closed, and the first switch K1, the second switch K2, and the third switch K3 are opened, the photovoltaic power supply unit charges the battery 300. Figure 7As shown by the red arrow in the figure. At this time, the photovoltaic panel 410 is connected to the battery 300 through the first inductor L1, the first switch tube S1 and the second switch tube S2. The first inductor L1, the first switch tube S1 and the second switch tube S2 form a Boost circuit. The driving signals of the first switch tube S1 and the second switch tube S2 are complementary. The Boost function can be realized by changing the duty cycle of the driving signal to boost the voltage output by the photovoltaic panel 410.

[0092] When the fourth switch K4 is closed, and the first switch K1, the second switch K2, and the third switch K3 are opened, the battery 300 supplies power to the low voltage output module 510. Figure 7 As shown by the green arrow in . At this time, the battery 300 is connected to the low voltage output module 510 through the second inductor L2, the third switch tube S3 and the fourth switch tube S4. The second inductor L2, the third switch tube S3 and the fourth switch tube S4 form a Buck circuit. The driving signals of the third switch tube S3 and the fourth switch tube S4 are complementary. The Buck function can be realized by changing the duty cycle of the driving signal to reduce the voltage of the DC power output by the battery 300.

[0093] When the third switch K3 and the fourth switch K4 are closed and the first switch K1 and the second switch K2 are open, the photovoltaic power supply unit charges the battery 300 and supplies power to the low voltage output module 510. The photovoltaic injection and low voltage output transformation functions are performed simultaneously.

[0094] After adopting the energy storage system of this embodiment, there is no need to add additional Boost circuits and Buck circuits. The photovoltaic injection and low-voltage output transformation functions can be realized by simply switching the connection mode of the original devices. Moreover, since the energy paths do not overlap, the photovoltaic injection and low-voltage output transformation functions can be performed simultaneously.

[0095] See attached Figure 8 The CLLC circuit in the energy storage system of another embodiment of the present application is exemplarily described. The energy storage system includes a power factor correction circuit (not shown in the figure), a DC-DC conversion circuit, a battery 300 and a photovoltaic power supply unit. The DC-DC conversion circuit includes a full-bridge inverter circuit (not shown in the figure), a CLLC circuit 220" and a full-bridge rectifier circuit 230". The power factor correction circuit and the full-bridge inverter circuit are the same as the power factor correction circuit 100 and the full-bridge inverter circuit 210 in the above-mentioned embodiment, and will not be repeated here.

[0096] The CLLC circuit 220" includes a first inductor L1, a second inductor L2, a transformer T1, a first switch K1 and a second switch K2, a capacitor C2, an inductor L4 (not shown in the figure), a capacitor C4 (not shown in the figure) and an excitation inductor Lm (not shown in the figure), and the full-bridge rectifier circuit 230" includes a first switch tube S1, a second switch tube S2, a third switch S3, a fourth switch tube S4, a first capacitor C1 and a third switch K3.

[0097] The first end of the first switch tube S1 is electrically connected to the first end of the battery 300, the second end of the first switch tube S1 is electrically connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is electrically connected to the first end of the second switch tube S2, the second end of the second switch tube S2 is electrically connected to the second end of the battery 300, and the third switch K3 is connected in parallel to both ends of the first capacitor C1.

[0098] A first end of the third switch tube S3 is electrically connected to a first end of the battery 300 , a second end of the third switch tube S3 is electrically connected to a first end of the fourth switch tube S4 , and a second end of the fourth switch tube S4 is electrically connected to a second end of the battery 300 .

[0099] The first end of the first inductor L1 is electrically connected to the first end of the second switch tube S2, and the second end of the first inductor L2 is electrically connected to the first end of the first switch K1. The first switch K1 can be a single-pole double-throw switch or a relay. The second end of the first switch K1 (i.e., contact ①) is electrically connected to the first end of the winding on the first side of the transformer T1 through the capacitor C2, and the third end of the first switch K3 (i.e., contact ②) is electrically connected to the first end of the photovoltaic power supply unit (i.e., photovoltaic panel 410). The second end of the photovoltaic power supply unit (i.e., photovoltaic panel 410) is electrically connected to the second end of the second switch tube S2. Among them, the first switch K1 can selectively conduct its first end and the second end (i.e., close to contact ①), or conduct its first end and the third end (i.e., close to contact ②).

[0100] The first end of the second inductor L2 is electrically connected to the second end of the third switch tube S3, and the second end of the second inductor L2 is electrically connected to the first end of the second switch K2. The second switch K2 may be a single-pole double-throw switch or a relay, the second end of the second switch K2 (i.e., contact ①) is electrically connected to the second end of the winding on the first side of the transformer T1, and the third end of the second switch K2 (i.e., contact ②) is electrically connected to the second end of the third switch tube S3, wherein the second switch K2 can selectively conduct its first end and second end (i.e., contact ②), or conduct its first end and third end (i.e., close to contact ②).

[0101] When the first switch K1 and the second switch K2 are both closed to contact ①, and the third switch K3 is closed, the energy storage system works in the normal charging mode, the photovoltaic input is disconnected, and the mains power charges the battery 300. At this time, the mains power is provided to the battery 300 through the power factor correction circuit and the DC-DC conversion circuit to charge the battery 300.

[0102] See attached Fig. 9 When the first switch K1 and the second switch K2 are both closed to contact ② and the third switch K3 is opened, the original circuit is reconstructed into a single-ended primary inductor converter (SEPIC) to complete the buck-boost of the photovoltaic output. Its equivalent circuit is as follows: Fig.10 As shown. The input and output voltage relationship of the SEPIC circuit is:

[0103]

[0104] Where U o is the output voltage, U in is the output voltage, D is the duty cycle of the S2 drive signal of the second switch tube, and the first switch tube S1 drive signal is complementary to the second switch tube S2. The SEPIC circuit is used as the power conversion circuit for photovoltaic input. Compared with the commonly used Boost circuit, the SEPIC circuit has the ability to adjust the voltage and step up at the same time, which is more suitable for occasions where the photovoltaic output is unstable in practice. Compared with the Buck-Boost circuit, the input and output voltage polarities of the SEPIC circuit are the same, which will not cause grounding difficulties or drive suspension problems caused by the reverse polarity of the output voltage.

[0105] See attached Fig.10 , the working process of the energy storage system of this embodiment is as follows:

[0106] Step 1: The energy storage system accepts a charging request, where the charging request can be a detected plug-in signal, or a signal sent by the system itself when the battery 300 power level is lower than a certain threshold without plugging in the battery;

[0107] Step 2: Initialize all components of the energy storage system and enter the self-check stage before work;

[0108] Step 3: Determine whether the charging request signal is a plug-in signal. If so, proceed to step 4 to start plug-in charging (i.e., receiving AC power for charging); if not, proceed to step 5 to start photovoltaic charging;

[0109] Step 4: The first switch K1 and the second switch K2 are both closed to contact ①, the third switch K3 is closed, and the first switch tube S1 to the fourth switch tube S4 are configured in a synchronous rectification drive mode. At this time, the control method is consistent with that of a traditional on-board charger.

[0110] Step 5: The first switch K1 and the first switch K2 are both closed to contact ②, the third switch K3 is opened, the first switch tube S1 and the second switch tube S2 are configured in a complementary driving mode, the driving signal of the third switch tube S3 is set to a low level, the driving waveform is closed, the driving signal of the fourth switch tube S4 is set to a high level, and the duty ratio of the driving signals of the first switch tube S1 and the second switch tube S2 is adjusted to meet the corresponding step-up and step-down requirements.

[0111] Step 6: Feedback the remaining SOC of the battery 300 through the host computer, and detect whether the user issues a stop signal. The stop signal here can be a detected gun-pulling signal, or it can be a signal issued by the photovoltaic panel 410 itself when the SOC reaches a certain threshold or the output is lower than a certain threshold due to insufficient illumination. If a stop signal is detected, the charging process is terminated. If a stop signal is not detected, the charging process remains unchanged. Once a gun-plugging signal is detected, the charging is immediately turned off and returns to step 3.

[0112] In this embodiment, the energy storage system may further include a low-voltage output unit, which includes a low-voltage output module 510 and a fourth switch K4, wherein the low-voltage output module 510 may include a battery and / or a load. The first end of the low-voltage output module 510 is electrically connected to the second end of the second inductor L2 through the fourth switch K4, and the second end of the low-voltage output module 510 is electrically connected to the second end of the fourth switch tube S4. In some other embodiments, the second end of the low-voltage output module 510 may also be electrically connected to the first end of the third switch tube S3.

[0113] Thus, when the fourth switch K4 is closed, the battery 300 is connected to the low voltage output module 510 through the second inductor L2, the third switch tube S3 and the fourth switch tube S4. The second inductor L2, the third switch tube S3 and the fourth switch tube S4 can form a Buck circuit, the driving signals of the third switch tube S3 and the fourth switch tube S4 are complementary, and the Buck function can be realized by changing the duty cycle of the driving signal to reduce the voltage of the DC power output by the battery 300.

[0114] The present application also provides a vehicle, which includes the energy storage system as described above.

[0115] 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 to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0116] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0117] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various utility model 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 interpreted as reflecting the following intention: the claimed application requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features that are less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0118] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0119] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0120] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. An energy storage system, characterized in that: include: CLLC circuit; A full-bridge rectifier circuit connected to the CLLC circuit; a battery, electrically connected to the full-bridge rectifier circuit; A photovoltaic power supply unit connected to the CLLC circuit and the full-bridge rectifier circuit; A low voltage output unit is connected to the CLLC circuit and the full-bridge rectifier circuit.

2. The energy storage system according to claim 1, characterized in that: The full-bridge rectifier circuit includes a first bridge arm and a second bridge arm, and the CLLC circuit includes a first inductor, a transformer and a first switch; Two ends of the first bridge arm are electrically connected to two ends of the battery, and a midpoint of the first bridge arm is electrically connected to a first end of the first inductor; Two ends of the second bridge arm are electrically connected to two ends of the battery, and a midpoint of the second bridge arm is electrically connected to a first end of a winding on one side of the transformer; The second end of the first inductor is electrically connected to the second end of the winding; The first switch is arranged between the second end of the first inductor and the second end of the winding, or between the midpoint of the second bridge arm and the first end of the winding.

3. The energy storage system according to claim 2, characterized in that: The photovoltaic power supply unit includes a photovoltaic panel and a second switch; The first end of the photovoltaic panel is electrically connected to the second end of the first inductor through the second switch, and the second end of the photovoltaic panel is electrically connected to one end of the first bridge arm.

4. The energy storage system according to claim 2, characterized in that: The low-voltage output unit includes a low-voltage output module and a third switch, wherein the low-voltage output module includes a battery and / or a load; The first end of the low-voltage output module is electrically connected to the second end of the first inductor through the third switch, and the second end of the low-voltage output module is electrically connected to one end of the first bridge arm.

5. The energy storage system according to claim 1, characterized in that: The full-bridge rectifier circuit includes a first bridge arm and a second bridge arm, and the CLLC circuit includes a first inductor, a second inductor, a transformer, a first switch and a second switch; Two ends of the first bridge arm are electrically connected to two ends of the battery, and a midpoint of the first bridge arm is electrically connected to a first end of the first inductor; Two ends of the second bridge arm are electrically connected to two ends of the battery, and a midpoint of the second bridge arm is electrically connected to a first end of the second inductor; The second end of the first inductor is electrically connected to the first end of the winding on one side of the transformer through the first switch; The second end of the second inductor is electrically connected to the second end of the winding through the second switch.

6. The energy storage system according to claim 5, characterized in that: The photovoltaic power supply unit includes a photovoltaic panel and a third switch; The first end of the photovoltaic panel is electrically connected to the second end of the first inductor through the third switch, and the second end of the photovoltaic panel is electrically connected to one end of the first bridge arm.

7. The energy storage system according to claim 5, characterized in that: The low-voltage output unit includes a low-voltage output module and a fourth switch, wherein the low-voltage output module includes a battery and / or a load; The first end of the low voltage output unit is electrically connected to the second end of the second inductor through the fourth switch, and the second end of the low voltage output module is electrically connected to one end of the second bridge arm.

8. The energy storage system according to claim 1, characterized in that: The CLLC circuit includes a first inductor, a second inductor, a transformer, a first switch and a second switch, and the full-bridge rectifier circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first capacitor and a third switch; The first end of the first switch tube is electrically connected to the first end of the battery, the second end of the first switch tube is electrically connected to the first end of the first capacitor, the second end of the first capacitor is electrically connected to the first end of the second switch tube, the second end of the second switch tube is electrically connected to the second end of the battery, and the third switch is connected in parallel to both ends of the first capacitor; The first end of the third switch tube is electrically connected to the first end of the battery, the second end of the third switch tube is electrically connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is electrically connected to the second end of the battery; The first end of the first inductor is electrically connected to the first end of the second switch tube, the second end of the first inductor is electrically connected to the first end of the first switch, the second end of the first switch is electrically connected to the first end of the winding on one side of the transformer, the third end of the first switch is electrically connected to the first end of the photovoltaic power supply unit, and the second end of the photovoltaic power supply unit is electrically connected to the second end of the second switch tube, wherein the first switch can selectively conduct its first end and the second end, or conduct its first end and the third end; The first end of the second inductor is electrically connected to the second end of the third switch tube, the second end of the second inductor is electrically connected to the first end of the second switch, the second end of the second switch is electrically connected to the second end of the winding, and the third end of the second switch is electrically connected to the second end of the third switch tube, wherein the second switch can selectively turn on its first end and the second end, or turn on its first end and the third end.

9. The energy storage system according to claim 8, characterized in that: The low-voltage output unit includes a low-voltage output module and a fourth switch, wherein the low-voltage output module includes a battery and / or a load; The first end of the low voltage output module is electrically connected to the second end of the second inductor through the fourth switch, and the second end of the low voltage output module is electrically connected to the first end of the third switch tube or the second end of the fourth switch tube.

10. The energy storage system according to claim 1, characterized in that: The energy storage system also includes a power factor correction circuit and a full-bridge inverter circuit. The power factor correction circuit is connected to the full-bridge inverter circuit, and the full-bridge inverter circuit is connected to the CLLC circuit.

11. A vehicle, characterized in that: Comprising the energy storage system as described in any one of claims 1-10.

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