An energy storage system

Abstract

The application provides an energy storage system, belonging to the technical field of energy storage. The energy storage system comprises a control assembly, an alternating current source, an energy storage battery, a power unit and a switch. The control assembly comprises an auxiliary source and a controller connected with each other. The auxiliary source is connected with the alternating current source and the energy storage battery through the switch. The alternating current voltage output by the alternating current source is converted and then acts on the direct current voltage of the auxiliary source, and the direct current voltage is less than the direct current voltage output by the energy storage battery to the auxiliary source. The controller is connected with the power unit and the switch, and the power unit is connected with the alternating current source and the energy storage battery. The controller is used for controlling the power transmission direction of the switch and the power unit. By using the application, the power supply of the control assembly can be flexibly selected between the energy storage battery and the alternating current source, and the flexibility of the power supply of the control assembly can be improved.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an energy storage system. Background Technology

[0002] The energy storage system includes control components, energy storage batteries, AC power sources, and power units. The control components can switch the direction of power transmission between the energy storage batteries and the AC power sources by controlling the power units, thereby enabling peak shaving and valley filling of the power grid connected to the AC power sources.

[0003] Currently, the control components in energy storage systems can be powered by energy storage batteries or by AC power sources, which is a single and inflexible power supply method. Utility Model Content

[0004] This application provides an energy storage system that can solve the technical problems existing in related technologies. The technical solution is as follows:

[0005] The energy storage system provided in this application includes a control component, an AC power source, an energy storage battery, power units, and a switch. The control component includes an auxiliary power source and a controller connected together. The auxiliary power source is connected to the AC power source and, through the switch, to the energy storage battery. The AC voltage output from the AC power source is converted and applied as a DC voltage to the auxiliary power source, which is less than the DC voltage output from the energy storage battery to the auxiliary power source. The controller is connected to both the power units and the switch. The power units are connected to both the AC power source and the energy storage battery. The controller controls the direction of power transmission for the corresponding switches and power units.

[0006] Optionally, the control component may also include an auxiliary device connected to an auxiliary power source.

[0007] Optionally, auxiliary devices may include lighting devices, heat dissipation devices, fire-fighting devices, relays or contactors.

[0008] Optionally, the energy storage system also includes a first rectifier circuit, which is connected to both an AC source and an auxiliary source.

[0009] Optionally, the auxiliary power source includes a voltage comparison circuit and at least one voltage conversion circuit. The voltage comparison circuit includes a first comparison input terminal, a second comparison input terminal, and a power output terminal.

[0010] The first comparison input terminal is connected to the DC voltage output by the energy storage battery, and the second comparison input terminal is connected to the DC voltage converted from the AC voltage output by the AC source; the power output terminal is connected to at least one voltage conversion circuit; at least one voltage conversion circuit is connected to the controller.

[0011] Optionally, the auxiliary power source includes a second rectifier circuit, which is connected to the second comparator input and the AC source, respectively.

[0012] Optionally, the period when the switch is open corresponds to the period when the electricity price of the AC source connected to the power grid is high, and the period when the switch is closed corresponds to the period when the electricity price of the AC source connected to the power grid is low.

[0013] Optionally, the power unit is an energy storage converter.

[0014] Optionally, the AC source voltage is 380V, and the energy storage battery voltage is greater than 538V.

[0015] Optionally, the output voltage at the connection point between the auxiliary power source and the controller is 5V or 3.3V.

[0016] The technical solution provided in this application includes at least the following beneficial effects:

[0017] This application provides an energy storage system in which, when the switch between the auxiliary power source and the energy storage battery is open, the auxiliary power source in the control component draws power from the AC source to power the controller. When the switch between the auxiliary power source and the energy storage battery is closed, because the DC voltage applied to the auxiliary power source by the energy storage battery is greater than the DC voltage applied to the auxiliary power source by the AC source, the auxiliary power source draws power from the energy storage battery to power the controller. Therefore, by using the storage system provided in this application, the power supply for the control component can be flexibly selected between the energy storage battery and the AC source, improving the flexibility of powering the control component.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of the structure of an auxiliary source provided in an embodiment of this application;

[0024] Figure 5This is a schematic diagram of the structure of an auxiliary source provided in an embodiment of this application.

[0025] Legend

[0026] 1. Control component; 11. Auxiliary power source; 111. Voltage comparison circuit; 1111. First comparison input terminal; 1112. Second comparison input terminal; 1113. Power output terminal; 112. Voltage conversion circuit; 113. Second rectifier circuit; 12. Controller; 13. Auxiliary device;

[0027] 2. AC power source; 3. Energy storage battery; 4. Power unit; 5. Switch; 6. First rectifier circuit. Detailed Implementation

[0028] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] The energy storage system includes control components, energy storage batteries, AC power sources, and power units. The control components can switch the direction of power transmission between the energy storage batteries and the AC power sources by controlling the power units, thereby enabling peak shaving and valley filling of the power grid connected to the AC power sources.

[0030] Peak shaving and valley filling refers to converting AC power from the power grid into DC power through the power units of an energy storage system and storing it in the energy storage batteries during periods of low electricity demand. During periods of high electricity demand, the power units convert the DC power from the energy storage batteries back into AC power and output it to the power grid.

[0031] Generally, electricity prices are relatively low during off-peak hours and relatively high during peak hours. Therefore, using energy storage systems to smooth out peak demand and fill valleys can not only achieve a balance between electricity supply and demand but also generate economic benefits and reduce the operating costs of energy storage systems.

[0032] Currently, energy storage manufacturers focus more on the efficiency of energy storage batteries or power units in energy storage systems to reduce energy loss during power transmission, thereby achieving energy savings and cost reduction in one step. However, the control components included in the energy storage system are often overlooked by energy storage manufacturers because their overall power consumption is relatively small compared to the energy loss caused by energy storage batteries or power units.

[0033] In energy storage systems, the auxiliary power sources for control components are typically either fixed to drawing power from the energy storage battery or vice versa. This means that the power supply methods for control components in energy storage systems are not flexible enough, and power supply costs could be further reduced.

[0034] This application provides an energy storage system in which the control component can flexibly select one of the energy storage battery and the AC power source to supply power, thereby improving the flexibility of the energy storage system in supplying power to the control component and reducing the power supply cost to the control component.

[0035] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application, as shown below. Figure 1 As shown, the energy storage system includes a control component 1, an AC power source 2, an energy storage battery 3, a power unit 4, and a switch 5.

[0036] The control component 1 can also be called a control system, which includes at least an auxiliary power source 11 and a controller 12. The auxiliary power source 11 includes multiple power input terminals and multiple power output terminals, one of which can be connected to the power input terminal of the controller 12 to provide operating voltage to the controller 12.

[0037] Auxiliary power source 11 includes a power input terminal that can be connected to AC source 2, which can be an AC source connected to the power grid. In one example, auxiliary power source 11 internally includes an AC / DC (alternating current to direct current) conversion circuit that can convert AC power input through the power input terminal into DC power. In another example, an AC / DC conversion circuit is connected between the power input terminal of auxiliary power source 11 and AC source 2, which can convert the AC power output from AC source 2 into DC power before inputting it to the power input terminal of auxiliary power source 11.

[0038] The auxiliary power source 11 includes another power input terminal that can be connected to the energy storage battery 3 via switch 5. When switch 5 is closed, the DC power output from the energy storage battery 3 can be input to the power input terminal of the auxiliary power source 11. The design voltage of the energy storage battery 3, that is, the DC voltage corresponding to the DC output point of the energy storage battery 3, is greater than the DC voltage converted from the AC voltage output of the AC source. For example, if the AC voltage output from the AC source is 380V, and the converted DC voltage is 537V, the DC voltage output by the energy storage battery can be greater than 537V. For instance, considering that the voltage of the AC source 2 or the energy storage battery 3 may fluctuate to some extent, the DC voltage output by the energy storage battery can be at least greater than 538V.

[0039] The controller 12 is connected to the power unit 4 and the switch 5. The controller 12 can be a control chip or a control board, etc.

[0040] Power unit 4 can be connected between AC source 2 and energy storage battery 3, enabling bidirectional transfer of electrical energy between the AC grid and the energy stored in energy storage battery 2. For example, it can be a power conversion system (PCS). Under the control of controller 12, power unit 4 can control the direction of electrical energy transfer between AC source 2 and energy storage battery 3, that is, it can transfer electrical energy from AC source 2 to energy storage battery 3, or transfer the electrical energy stored in energy storage battery 3 to the power grid connected to the AC source. For example, AC source 2, energy storage battery 3, and power unit 4 can also be connected in parallel with a DC bus capacitor to suppress voltage fluctuations between AC source 2 and energy storage battery 3.

[0041] Switch 5 can be implemented using devices such as Insulated-Gate Bipolar Transistors (IGBTs) and Field-Effect Transistors (FETs). The control terminal of switch 5 can be connected to controller 12, which controls the opening and closing of switch 5. When controller 12 controls switch 5 to open, the power input terminal of auxiliary power source 11 is only connected to AC source 2. Therefore, when switch 5 is open, auxiliary power source 11 draws power from AC source 2, thus supplying power to control component 1 through AC source 2. When controller 12 controls switch 5 to close, the two power input terminals of auxiliary power source 11 are connected to AC source 2 and energy storage battery 3 respectively. Since the DC voltage of energy storage battery 3 is designed to be greater than the DC voltage converted from the AC voltage of AC source 2, auxiliary power source 11 draws power from energy storage battery 3, thus supplying power to control component 1 through energy storage battery 3.

[0042] As can be seen, in this embodiment of the application, by setting a switch 5 between the auxiliary power source 11 and the energy storage power source 3, the AC power source 2 and the energy storage power source 3 can be flexibly switched to supply power to the control component 1, thereby improving the flexibility of supplying power to the control component 1.

[0043] In some embodiments, the control component 1 further includes an auxiliary device 13, such as... Figure 2 As shown, the auxiliary power source 11 includes a power output terminal that can be connected to the power input terminal of the auxiliary device 13 to supply power to the auxiliary device 13. The auxiliary device can be a hardware device that assists in the operation of the energy storage system or the operation of the controller 12. For example, the auxiliary device 13 can be at least one of a lighting device, a heat dissipation device, a fire-fighting device, a relay, and a contactor. When the auxiliary device 13 includes multiple devices, the auxiliary power source 11 can supply power to each of them separately. In this way, flexible control can be achieved for the power supply to the auxiliary device 13 in the control assembly 1, thereby reducing the power cost of the auxiliary device 13.

[0044] In one feasible implementation, the energy storage system includes a first rectifier circuit 6 for converting the alternating current output from the alternating current source 2 into direct current to supply power to the control system. For example... Figure 3 As shown, the input terminal of the first rectifier circuit 6 can be connected to the output terminal of the AC source 2, and the output terminal of the first rectifier circuit 6 can be connected to the power input terminal of the auxiliary source 11. The first rectifier circuit 6 can be an AC / DC converter circuit, which can convert the AC power output from the AC source 2 into DC power and input it to the auxiliary source 11.

[0045] In one possible implementation, the auxiliary source 11 includes a voltage comparison circuit 111 and at least one voltage conversion circuit 112. For example... Figure 4 As shown, the voltage comparison circuit 111 includes a first comparison input terminal 1111, a second comparison input terminal 1112, and a power output terminal 1113. The first comparison input terminal 1111 is connected to the DC voltage output from the energy storage battery 3, and the second comparison input terminal 1112 is connected to the DC voltage converted from the AC voltage output from the AC source 2. Figure 4 As shown, a first rectifier circuit 6 can be connected between the second comparison input terminal 1112 and the AC source. The first rectifier circuit 6 converts the AC power input from the AC source 2 into DC power, which is then input to the second comparison input terminal 1112. In this way, the voltage comparison circuit 111 can compare the DC voltage at the first comparison input terminal 1111 with the DC voltage at the second comparison input terminal 1112, and conduct the side with the larger DC voltage to the power output terminal 1113. In one example, this voltage comparison circuit 111 can be implemented using a diode clamping circuit.

[0046] Since the voltage of the energy storage battery 3 and the AC power source is relatively large compared to the operating voltage of the control component 1 or the auxiliary device 13, the power output terminal 1113 of the voltage comparison circuit 111 can be connected to at least one voltage conversion circuit 112, thereby reducing the DC voltage value output from the power output terminal 1113 through the voltage conversion circuit 112. Figure 4 As shown, at least one voltage conversion circuit 112 is connected to the power supply terminal of the controller 12 to provide a stable operating voltage for the controller 12. For example, the voltage conversion circuit 112 can convert the DC voltage corresponding to the AC source 2 or the energy storage battery 3 into a 5V or 3.3V DC voltage, thereby providing the operating voltage for the controller 12. In one example, when there are multiple voltage conversion circuits 112, the output voltage values ​​of different voltage conversion circuits 112 can be different, thus meeting the operating voltage requirements of different devices.

[0047] In some embodiments, the auxiliary power source 11 may contain a second rectifier circuit 113, such as Figure 5 As shown, the input terminal of the second rectifier circuit 113 can be connected to the output terminal of the AC source 2, and the output terminal of the second rectifier circuit 113 can be connected to the second comparison input terminal 1112 of the voltage comparator circuit 111. The second rectifier circuit 113 can be an AC / DC converter circuit, thus converting the AC power output from the AC source 2 into DC power, which is then input to the voltage comparator circuit 111. Therefore, by integrating the second rectifier circuit 113 inside the auxiliary source 11, there is no need to connect the first rectifier circuit 6 between the AC source 2 and the auxiliary source 11, thereby improving the device integration density.

[0048] In one feasible approach, the period when switch 5 is open corresponds to the period when the electricity price of the grid to which AC source 2 is connected is high, and the period when switch 5 is closed corresponds to the period when the electricity price of the grid to which AC source 2 is connected is low.

[0049] In implementation, the controller can store periods with low electricity prices and periods with high electricity prices separately. When the controller determines that a period with low electricity prices has begun, it can control switch 5 to open, thereby using a lower-priced AC source to power control component 1. When the controller 12 determines that a period with high electricity prices has begun, it can control switch 5 to open, using the energy storage battery to power control component 1. In this way, compared to control component 1 being constantly powered by AC source 2, periods with high grid electricity prices for the AC source can be avoided, thus saving on the electricity cost of the energy storage system. Conversely, compared to control component 1 being constantly powered by the energy storage battery, energy loss caused by the transfer of electricity from the AC source to the energy storage battery and then from the energy storage battery to control component 1 can be avoided. Therefore, the energy storage system provided in this application can reduce the power supply cost of the control component, thereby further reducing the overall cost of the energy storage system.

[0050] For example, the energy storage system provided in this application embodiment can be an outdoor energy storage cabinet system or a containerized energy storage system. Using this application can reduce the electricity costs of outdoor energy storage cabinet systems or containerized energy storage systems.

[0051] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An energy storage system, characterized in that, The energy storage system includes a control component (1), an AC power source (2), an energy storage battery (3), a power unit (4), and a switch (5); The control component (1) includes a connected auxiliary power source (11) and a controller (12); The auxiliary power source (11) is connected to the AC power source (2) and connected to the energy storage battery (3) through the switch (5). The AC voltage output by the AC power source (2) is converted and applied to the auxiliary power source (11) to a DC voltage that is less than the DC voltage output by the energy storage battery (3) to the auxiliary power source (11). The controller (12) is connected to the power unit (4) and the switch (5) respectively. The power unit (4) is connected to the AC source (2) and the energy storage battery (3) respectively. The controller (12) is used to control the power transmission direction corresponding to the switch (5) and the power unit (4).

2. The energy storage system according to claim 1, characterized in that, The control component (1) further includes an auxiliary device (13) connected to the auxiliary source (11).

3. The energy storage system according to claim 2, characterized in that, The auxiliary device (13) includes a lighting device, a heat dissipation device, a fire-fighting device, a relay or a contactor.

4. The energy storage system according to claim 1, characterized in that, The energy storage system also includes a first rectifier circuit (6), which is connected to the AC source (2) and the auxiliary source (11) respectively.

5. The energy storage system according to claim 1, characterized in that, The auxiliary power source (11) includes a voltage comparison circuit (111) and at least one voltage conversion circuit (112). The voltage comparison circuit (111) includes a first comparison input terminal (1111), a second comparison input terminal (1112), and a power output terminal (1113). The first comparison input terminal (1111) is connected to the DC voltage output by the energy storage battery (3), and the second comparison input terminal (1112) is connected to the DC voltage after converting the AC voltage output by the AC source (2); The power output terminal (1113) is connected to the at least one voltage conversion circuit (112); The at least one voltage conversion circuit (112) is connected to the controller (12).

6. The energy storage system according to claim 5, characterized in that, The auxiliary power source (11) includes a second rectifier circuit (113), which is connected to the second comparison input terminal (1112) and the AC power source (2).

7. The energy storage system according to any one of claims 1 to 6, characterized in that, The period when the switch (5) is open is the period when the electricity price of the power grid to which the AC source (2) is connected is high, and the period when the switch (5) is closed is the period when the electricity price of the power grid to which the AC source (2) is connected is low.

8. The energy storage system according to any one of claims 1 to 6, characterized in that, The power unit (4) is an energy storage converter.

9. The energy storage system according to any one of claims 1 to 6, characterized in that, The voltage of the AC source (2) is 380V, and the voltage of the energy storage battery (3) is greater than 538V.

10. The energy storage system according to any one of claims 1 to 6, characterized in that, The output voltage of the connection between the auxiliary power source (11) and the controller (12) is 5V or 3.3V.

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