Container energy storage system and power distribution device and power distribution method thereof

Abstract

The invention discloses a container energy storage system and a power distribution device and method thereof, and the device comprises a first electric energy conversion unit which is suitable for being connected with a power generation unit and converting the electric energy outputted by the power generation unit, so as to charge a battery energy storage unit in the container energy storage system; the second electric energy conversion unit is suitable for being connected with the battery energy storage unit and converting the electric energy output by the battery energy storage unit so as to discharge the power grid; the control unit is configured to control the first electric energy conversion unit to charge the battery energy storage unit when receiving a discharging instruction of the power grid and under the condition that the electric quantity of the battery energy storage unit does not meet the required power of the power grid, and control the second electric energy conversion unit to charge the battery energy storage unit when the electric quantity of the battery energy storage unit meets the required power of the power grid; and controlling the second electric energy conversion unit to output electric energy to discharge to the power grid. Therefore, electric energy generated by the power generation unit is stored in the energy storage battery unit, the energy storage battery unit participates in power grid power adjustment, and the energy utilization rate is increased.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a power distribution device of a container energy storage system, a power distribution method of a container energy storage system, and a container energy storage system. Background Art

[0002] At present, the combination of containers and new energy sources as energy storage systems has been widely used, for example, the combination of containers and solar energy. However, some related control schemes fail to fully utilize energy in energy storage and supply in energy storage systems, resulting in energy waste. Summary of the invention

[0003] In view of the above problems, the present application provides a container energy storage system and its power distribution device and power distribution method, wherein a first power conversion unit converts the power output by the power generation unit to charge the battery energy storage unit in the container energy storage system, and a second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid. When a discharge instruction from the power grid is received, if the power of the battery energy storage unit does not meet the power requirement of the power grid, the control unit controls the first power conversion unit to charge the battery energy storage unit first, and when the power of the battery energy storage unit meets the power requirement of the power grid, controls the second power conversion unit to output power to discharge to the power grid, and stores the power generated by the power generation unit in the energy storage battery unit. The energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy.

[0004] In a first aspect, the present application provides a power distribution device of a container energy storage system, comprising: a first power conversion unit, the first power conversion unit being suitable for connecting to a power generation unit and converting the power output by the power generation unit to charge a battery energy storage unit in the container energy storage system; a second power conversion unit, the second power conversion unit being suitable for connecting to the battery energy storage unit and converting the power output by the battery energy storage unit to discharge to a power grid; a control unit being configured to, upon receiving a discharge instruction from the power grid, control the first power conversion unit to charge the battery energy storage unit when the power of the battery energy storage unit meets the power requirement of the power grid, and control the second power conversion unit to output power to discharge to the power grid when the power of the battery energy storage unit meets the power requirement of the power grid, wherein the discharge instruction of the power grid includes the power requirement of the power grid.

[0005] In the technical solution of the embodiment of the present application, when the discharge instruction of the power grid is received, the power of the battery energy storage unit and the power demand of the power grid are obtained, and then the battery energy storage unit and the second power conversion unit are controlled according to the relationship between the power of the battery energy storage unit and the power demand of the power grid. For example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the control unit can first control the first power conversion unit to convert the power output by the power generation unit, and give priority to charging the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid, and the battery energy storage unit outputs power, and the second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid. For another example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the battery energy storage unit can be controlled to output power first, and the second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid, and the insufficient part is then controlled by the first power conversion unit to convert the power output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can make up for the insufficient part. Thus, the electric energy generated by the power generation unit is stored in the energy storage battery unit, and the energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy. For another example, when the power of the battery energy storage unit can meet the power demand of the power grid, the battery energy storage unit is controlled to output electric energy, and the second electric energy conversion unit converts the electric energy output by the battery energy storage unit, and the converted electric energy is discharged to the power grid.

[0006] In some embodiments, the second power conversion unit includes a first DC / AC converter, and the first DC / AC converter is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current, wherein the control unit is further configured to, when the power of the battery energy storage unit does not meet the power requirement of the power grid, control the first DC / AC converter to output the first alternating current to discharge the power grid, and when the power of the battery energy storage unit decreases to a preset power threshold, control the first power conversion unit to output electric energy to charge the battery energy storage unit until the power of the battery energy storage unit meets the power requirement of the power grid.

[0007] When receiving a discharge instruction from the power grid, if the power of the battery energy storage unit does not meet the power demand of the power grid, the battery energy storage unit is first controlled to output electric energy to discharge the power grid. Since the electric energy output by the battery energy storage unit cannot directly meet the power supply voltage of the power grid, it is necessary to convert the direct current output by the battery energy storage unit through the first DC / AC converter to output the first alternating current to discharge the power grid, so that the electric energy generated by the power generation unit can participate in the power regulation of the power grid and improve energy utilization. After the battery energy storage unit is discharged, the first electric energy conversion unit is controlled to convert the electric energy output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can meet the power demand of the power grid. For example, the power demand of the power grid is 1000W, and the power of the battery energy storage unit can only provide 700W of power. Then, after the battery energy storage unit is discharged, the electric energy output by the first power conversion unit is used to charge the battery energy storage unit. When the power of the battery energy storage unit can provide the remaining 300W of power, the charging is stopped, and the output power of the battery energy storage unit is controlled. The direct current output by the battery energy storage unit is converted by the first DC / AC converter to output the first alternating current to discharge to the power grid.

[0008] In some embodiments, the first power conversion unit includes a first DC / DC converter, and the first DC / DC converter is suitable for converting the direct current output by the power generation unit to output a first direct current, wherein the control unit is further configured to, when the power of the battery energy storage unit does not meet the power requirement of the power grid, control the first DC / DC converter to output the first direct current to charge the battery energy storage unit, and until the power of the battery energy storage unit meets the power requirement of the power grid, control the second power conversion unit to output electric energy to discharge the power grid.

[0009] When receiving a discharge instruction from the power grid, if the power of the battery energy storage unit cannot meet the power demand of the power grid, the battery energy storage unit will be charged first until the power of the battery energy storage unit can meet the demand of the power grid. At this time, the second power conversion unit is controlled to convert the electric energy output by the battery energy storage unit to discharge to the power grid.

[0010] In some embodiments, the first power conversion unit includes a second DC / AC converter, and the second DC / AC converter is suitable for converting the second direct current output by the first DC / DC converter to output a second alternating current, wherein the control unit is further configured to control the second DC / AC converter to output the second alternating current to power the AC load when the power of the battery energy storage unit meets the required power of the power grid and the power generation power of the power generation unit is greater than or equal to the required power of the AC load.

[0011] Prioritize charging the battery energy storage unit. When the power of the battery energy storage unit can meet the power demand of the power grid, it also supplies power to the AC load, thereby improving energy utilization and reducing the power consumption of the system auxiliary power supply.

[0012] In some embodiments, the control unit is further configured to control the first DC / DC converter to output the first direct current to charge the battery energy storage unit when the power generation power of the power generation unit is less than the required power of the AC load.

[0013] When the power generated by the power generation unit cannot meet the power demand of the AC load, the electric energy generated by the power generation unit is converted into the electric energy of the battery energy storage unit to minimize the abandoned light and improve the energy utilization rate.

[0014] In some embodiments, the above-mentioned power distribution device also includes: a third power conversion unit, which is suitable for connecting to an auxiliary power supply and converting the electric energy provided by the auxiliary power supply to supply power to a target DC load in the container energy storage system, and the supply voltage of the target DC load is less than a first preset voltage; the control unit is also configured to control the third power conversion unit to output electric energy to supply power to the target DC load according to the required power of the target DC load.

[0015] An auxiliary power supply is used to supply power to the target DC load (low-voltage DC load) to ensure the stable operation of the electrical equipment.

[0016] In some embodiments, the third power conversion unit includes a first AC / DC converter, which is suitable for converting the electric energy provided by the auxiliary power supply to output a third direct current, wherein the control unit is further configured to control the first AC / DC converter to output the third direct current to power the target DC load according to the required power of the target DC load.

[0017] Since the electric energy provided by the auxiliary power supply is AC power, it needs to be converted into DC power before supplying power to the target DC load. Therefore, the AC power provided by the auxiliary power supply needs to be converted by a first AC / DC converter to output a third DC power to supply power to the target DC load, wherein the supply voltage of the target DC load is generally 12V / 24V.

[0018] In some embodiments, the control unit includes at least one of an EMS controller of the power grid, a controller of the first power conversion unit, a controller of the second power conversion unit, and a controller of the third power conversion unit.

[0019] By integrating the various controllers in the container energy storage system into an energy storage domain controller (control unit), a smart energy management system is formed, which can intelligently adjust the power generation unit, battery energy storage unit and load conditions. Such an energy storage domain controller architecture reduces the complexity of the energy storage system controller and communication delay, and reduces the system failure rate.

[0020] In a second aspect, an embodiment of the present application provides a power distribution method for a container energy storage system, wherein the container energy storage system comprises a first power conversion unit and a second power conversion unit, wherein the first power conversion unit is suitable for connecting to a power generation unit and converting the power output by the power generation unit to charge a battery energy storage unit in the container energy storage system, and the second power conversion unit is suitable for connecting to the battery energy storage unit and converting the power output by the battery energy storage unit to discharge to a power grid, wherein the method comprises: upon receiving a discharge instruction from the power grid, obtaining the power of the battery energy storage unit and the required power of the power grid, wherein the discharge instruction of the power grid comprises the required power of the power grid; when the power of the battery energy storage unit does not meet the required power of the power grid, controlling the first power conversion unit to charge the battery energy storage unit, and when the power of the battery energy storage unit meets the required power of the power grid, controlling the second power conversion unit to output power to discharge to the power grid.

[0021] In the technical solution of the embodiment of the present application, when the discharge instruction of the power grid is received, the power of the battery energy storage unit and the power demand of the power grid are obtained, and then the battery energy storage unit and the second power conversion unit are controlled according to the relationship between the power of the battery energy storage unit and the power demand of the power grid. For example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the control unit can first control the first power conversion unit to convert the power output by the power generation unit, and give priority to charging the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid, and the battery energy storage unit outputs power, and the second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid. For another example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the battery energy storage unit can be controlled to output power first, and the second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid, and the insufficient part is then controlled by the first power conversion unit to convert the power output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can make up for the insufficient part. Thus, the electric energy generated by the power generation unit is stored in the energy storage battery unit, and the energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy. For another example, when the power of the battery energy storage unit can meet the power demand of the power grid, the battery energy storage unit is controlled to output electric energy, and the second electric energy conversion unit converts the electric energy output by the battery energy storage unit, and the converted electric energy is discharged to the power grid.

[0022] In some embodiments, the second power conversion unit includes a first DC / AC converter, and the first DC / AC converter is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current. The method also includes: when the power of the battery energy storage unit does not meet the power demand of the power grid, controlling the first DC / AC converter to output the first alternating current to discharge to the power grid, and when the power of the battery energy storage unit decreases to a preset power threshold, controlling the first power conversion unit to output electric energy to charge the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid. In this way, the electric energy generated by the power generation unit can participate in the power regulation of the power grid. When the power of the energy storage unit is insufficient, the electric energy generated by the power generation unit is used to charge the battery energy storage unit first to meet the power demand of the power grid and improve energy utilization.

[0023] In some embodiments, the first power conversion unit includes a first DC / DC converter, the first DC / DC converter is suitable for converting the direct current output by the power generation unit to output the first direct current, and the method further includes: when the power of the battery energy storage unit cannot meet the power demand of the power grid, controlling the first DC / DC converter to output the first direct current to charge the battery energy storage unit, until the power of the battery energy storage unit meets the power demand of the power grid, controlling the second power conversion unit to output electric energy to discharge the power grid. Thus, the electric energy generated by the power generation unit is used to charge the battery energy storage unit first to meet the power demand of the power grid.

[0024] In some embodiments, the first power conversion unit includes a second DC / AC converter, the second DC / AC converter is suitable for converting the second direct current output by the first DC / DC converter to output a second alternating current, and further includes: when the power of the battery energy storage unit meets the power demand of the power grid, if the power generation power of the power generation unit is greater than or equal to the power demand of the AC load, then the second DC / AC converter is controlled to output the second alternating current to supply power to the AC load; if the power generation power of the power generation unit is less than the power demand of the AC load, then the first DC / DC converter is controlled to output the first direct current to charge the battery energy storage unit. In the case of charging the battery energy storage unit first, if the power of the battery energy storage unit can meet the power demand of the power grid, then the AC load is supplied with power; if the power of the battery energy storage unit cannot meet the power demand of the power grid, then the battery energy storage unit is charged, thereby improving energy utilization and reducing power consumption of the system auxiliary power supply.

[0025] In some embodiments, the container energy storage system further includes a third power conversion unit, the third power conversion unit is suitable for connecting to an auxiliary power supply, and converting the power provided by the auxiliary power supply to supply power to a target DC load, the power supply voltage of the target DC load is less than a first preset voltage, and the method further includes: according to the required power of the target DC load, controlling the third power conversion unit to output power to supply power to the target DC load. Thus, when the power generation power of the power generation unit cannot meet the required power of the AC load, the power generated by the power generation unit is converted into the power of the battery energy storage unit, thereby minimizing the abandoned light and improving the energy utilization rate.

[0026] In a third aspect, an embodiment of the present application provides a container energy storage system, including a power generation unit and a power distribution device of the above-mentioned container energy storage system.

[0027] In some embodiments, the power generation unit includes at least one of a photovoltaic power generation component and a wind power generation component.

[0028] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0030] Figure 1 is a block diagram of a power distribution device of a container energy storage system according to some embodiments;

[0031] Figure 2 is a schematic diagram of a power distribution device of a container energy storage system according to some embodiments;

[0032] Figure 3 is a schematic diagram of the position of photovoltaic components according to some embodiments;

[0033] Figure 4 is a flow chart of a power distribution method for a container energy storage system according to some embodiments;

[0034] Figure 5 is a flow chart of a power distribution method for a container energy storage system according to some embodiments;

[0035] Figure 6is a block diagram of a container energy storage system according to some embodiments. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0038] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0039] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0041] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0042] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0043] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0044] In order to make the container energy storage system operate normally, the control system, battery management system, fire protection system and other electrical equipment are configured in the container energy storage system, so the container needs to be equipped with an auxiliary power supply for power distribution. Usually, the power supply of the entire energy storage system is taken from the power grid, and the external energy is not fully utilized. Therefore, when the container energy storage system uses external energy to power the load, it is necessary to consider the reasonable allocation of energy required for powering each load (low-voltage load and high-voltage load), and maximize the use of external energy (such as solar energy, wind energy, etc.) to reduce the power consumption of the mains while enabling the load to work normally.

[0045] Therefore, in an embodiment of the present application, the first power conversion unit converts the electric energy output by the power generation unit to charge the battery energy storage unit in the container energy storage system, and the second power conversion unit converts the electric energy output by the battery energy storage unit to discharge to the power grid. When a discharge instruction from the power grid is received, if the power of the battery energy storage unit does not meet the power requirement of the power grid, the control unit controls the first power conversion unit to charge the battery energy storage unit first, and when the power of the battery energy storage unit meets the power requirement of the power grid, controls the second power conversion unit to output electric energy to discharge to the power grid, and stores the electric energy generated by the power generation unit in the energy storage battery unit. The energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy.

[0046] For the convenience of explanation, the following embodiments are combined Figure 1 The power distribution device of the container energy storage system according to the embodiment of the present application is described.

[0047] Reference Figure 1 and Figure 2 As shown, the power distribution device of the container energy storage system in the embodiment of the present application may include a first power conversion unit 10 , a second power conversion unit 20 and a control unit 30 .

[0048] Among them, the first power conversion unit 10 is suitable for connecting to the power generation unit and converting the power output by the power generation unit to charge the battery energy storage unit in the container energy storage system. The second power conversion unit 20 is suitable for connecting to the battery energy storage unit and converting the power output by the battery energy storage unit to discharge to the power grid. The control unit 30 is configured to control the first power conversion unit to charge the battery energy storage unit when receiving a discharge instruction from the power grid, if the power of the battery energy storage unit meets the power demand of the power grid, and control the second power conversion unit to output power to discharge to the power grid when the power of the battery energy storage unit meets the power demand of the power grid, wherein the discharge instruction of the power grid includes the power demand of the power grid.

[0049] Specifically, when the energy storage power station needs the battery energy storage unit to discharge and participate in the peak and frequency regulation characteristics of the power grid, the electric energy generated by the power generation unit is first charged to the battery energy storage unit so that the battery energy storage unit has enough power to participate in the regulation of the power grid. When receiving the discharge instruction of the power grid, the control unit 30 obtains the power of the battery energy storage unit and the power demand of the power grid, and then controls the battery energy storage unit and the second power conversion unit according to the relationship between the power of the battery energy storage unit and the power demand of the power grid. For example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the control unit 30 can first control the first power conversion unit 10 to convert the power output by the power generation unit, and give priority to charging the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid, and the battery energy storage unit outputs the power, and the second power conversion unit 20 converts the power output by the battery energy storage unit to discharge to the power grid. For another example, the power generation unit may include at least one of a photovoltaic component and a wind power component. Due to the instability and volatility of the power generation unit, taking the photovoltaic component as an example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, if the external environment light and temperature are not good, the battery energy storage unit can be controlled to output electric energy first, and the second electric energy conversion unit 20 converts the electric energy output by the battery energy storage unit to discharge to the power grid. For the insufficient part, the first electric energy conversion unit 10 is controlled to convert the electric energy output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can make up for the insufficient part. Thus, the electric energy generated by the power generation unit is stored in the energy storage battery unit, and the energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy. For another example, when the power of the battery energy storage unit can meet the power demand of the power grid, the control unit 30 controls the battery energy storage unit to output electric energy, and the second electric energy conversion unit 20 converts the electric energy output by the battery energy storage unit, and the converted electric energy is discharged to the power grid.

[0050] In some embodiments, the second power conversion unit 20 may include a first DC / AC converter 21, which is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current, wherein the control unit 30 is further configured to control the first DC / AC converter 21 to output the first alternating current to discharge the grid when the power of the battery energy storage unit does not meet the power demand of the grid, and to control the first power conversion unit to output electric energy to charge the battery energy storage unit when the power of the battery energy storage unit decreases to a preset power threshold, until the power of the battery energy storage unit meets the power demand of the grid. The preset power threshold can be calibrated according to actual conditions, for example, the preset power threshold can be 0.

[0051] Specifically, when receiving the discharge instruction from the power grid, if the power of the battery energy storage unit does not meet the power demand of the power grid, the control unit 30 first controls the battery energy storage unit to output electric energy to discharge the power grid. Since the electric energy output by the battery energy storage unit cannot directly meet the power supply voltage of the power grid, it is necessary to convert the direct current output by the battery energy storage unit through the first DC / AC converter 21 to output the first alternating current and discharge it to the power grid, so that the electric energy generated by the power generation unit can participate in the power regulation of the power grid and improve the energy utilization rate. After the power of the battery energy storage unit is discharged, the first electric energy conversion unit 10 is controlled to convert the electric energy output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can meet the power demand of the power grid. For example, if the power demand of the power grid is 1000W, and the power of the battery energy storage unit can only provide 700W of power, then after the battery energy storage unit is discharged, the power output by the first power conversion unit 10 is used to charge the battery energy storage unit. When the power of the battery energy storage unit can provide the remaining 300W of power, the charging is stopped, and the power output of the battery energy storage unit is controlled. The direct current output by the battery energy storage unit is converted by the first DC / AC converter 21 to output the first alternating current and discharge to the power grid. In this way, the power generated by the power generation unit is used to charge the battery energy storage unit first, without affecting the battery energy storage unit's participation in the regulation of the power grid.

[0052] In some embodiments, the first power conversion unit 10 may include a first DC / DC converter 11, which is suitable for converting the direct current output by the power generation unit to output the first direct current, wherein the control unit 30 is further configured to control the first DC / DC converter 11 to output the first direct current to charge the battery energy storage unit when the power of the battery energy storage unit does not meet the power demand of the power grid, and control the second power conversion unit 20 to output electric energy to discharge the power grid when the power of the battery energy storage unit meets the power demand of the power grid. The voltage of the first direct current can generally be 1200V-1800V.

[0053] Specifically, upon receiving the discharge instruction from the power grid, the control unit 30 first determines whether the power of the battery energy storage unit can meet the power demand of the power grid. If the power of the battery energy storage unit cannot meet the power demand of the power grid, the battery energy storage unit can be charged first through the power generation unit. For example, the first DC / DC converter 11 is controlled to convert the electric energy output by the power generation unit to output the first direct current to charge the battery energy storage unit. In the process of charging the battery energy storage unit, the power of the battery energy storage unit is obtained in real time. When the power of the battery energy storage unit can meet the power demand of the power grid, the first DC / DC converter 11 is controlled to stop outputting the first direct current. Then the second power conversion unit 20 (i.e., the first DC / AC converter 21) is controlled to convert the electric energy output by the battery energy storage unit to output the first alternating current to discharge to the power grid.

[0054] In some embodiments, the first power conversion unit 10 may include a second DC / AC converter 12, and the second DC / AC converter 12 is suitable for converting the second direct current output by the first DC / DC converter 11 to output a second alternating current, wherein the control unit 30 is further configured to control the second DC / AC converter 12 to output the second alternating current to power the AC load if the power of the battery energy storage unit meets the power demand of the power grid and the power generation power of the power generation unit is greater than or equal to the power demand of the AC load.

[0055] Specifically, when the power generation power of the power generation unit is relatively large, the power demand of the AC load is also obtained while the power of the battery energy storage unit can meet the power demand of the power grid. Among them, when the power generation power of the power generation unit can meet the power demand of the AC load, it can also supply power to the AC load. The AC load generally includes a water cooling unit, etc., and its power supply voltage is a relatively large AC voltage. Therefore, it is necessary to control the second DC / AC converter 12 to convert the second direct current output by the first DC / DC converter 11 to output the second alternating current to supply power to the AC load, thereby improving energy utilization and reducing the power consumption of the system auxiliary power supply.

[0056] In some embodiments, the control unit 30 is further configured to control the first DC / DC converter 11 to output the first direct current to charge the battery energy storage unit when the power generation power of the power generation unit is less than the power demand of the AC load.

[0057] That is to say, when the power generated by the power generation unit cannot meet the power demand of the AC load, the auxiliary power supply can be controlled to supply power to the AC load so that the device can operate normally. In addition, in order to make full use of energy, the electric energy generated by the power generation unit is converted into the electric energy of the battery energy storage unit, that is, the first DC / DC converter 11 is controlled to convert the electric energy output by the power generation unit into the first direct current to charge the battery energy storage unit, thereby minimizing the abandoned light and improving the energy utilization rate.

[0058] In some embodiments, continue to refer to Figure 2 As shown, the above-mentioned power distribution device may further include: a third power conversion unit 40, which is suitable for connecting to an auxiliary power supply and converting the power provided by the auxiliary power supply to supply power to a target DC load in the container energy storage system, and the power supply voltage of the target DC load is less than the first preset voltage; the control unit 30 is also configured to control the third power conversion unit 40 to output power to supply power to the target DC load according to the required power of the target DC load. The first preset voltage can be calibrated according to actual conditions, for example, the first preset voltage is 12V or 24V.

[0059] That is to say, an auxiliary power supply is used to supply power to the target DC load (low-voltage DC load). At the same time, when the power generation power of the power generation unit cannot meet the required power of the AC load, the control unit 30 also controls the auxiliary power supply to directly supply power to the AC load to maintain the normal operation of the electrical equipment.

[0060] In some embodiments, the third power conversion unit includes a first AC / DC converter, which is suitable for converting the power provided by the auxiliary power supply to output a third direct current, wherein the control unit is also configured to control the first AC / DC converter to output the third direct current to power the target DC load according to the required power of the target DC load.

[0061] Specifically, since the electric energy provided by the auxiliary power supply is AC power, it is necessary to convert the AC power into DC power before supplying power to the target DC load. The AC power provided by the auxiliary power supply can be converted by a first AC / DC converter to output a third DC power to supply power to the target DC load, wherein the power supply voltage of the target DC load is generally 12V / 24V.

[0062] In some embodiments, the control unit 30 may include at least one of an EMS controller of the power grid, a controller of the first power conversion unit, a controller of the second power conversion unit, and a controller of the third power conversion unit.

[0063] Specifically, in order to reasonably distribute the electric energy generated by the power generation unit, the various controllers in the container energy storage system (including the controller of the first DC / DC converter, the controller of the first AC / DC converter, the controller of the first DC / AC converter, the controller of the second DC / AC converter, etc.) and the EMS controller of the power grid can be integrated into an energy storage domain controller (control unit) to form a smart energy management system, which can perform intelligent adjustments to the power generation unit, battery energy storage unit and load conditions. Such an energy storage domain controller architecture reduces the complexity of the energy storage system controller and communication delay, and reduces the system failure rate.

[0064] As a specific example, a power generation unit including a photovoltaic module is taken as an example for explanation.

[0065] In common photovoltaic energy storage power stations, photovoltaic modules and container energy storage systems are placed separately in different areas, occupying a huge area. In order to solve the problem of large floor space, this application integrates photovoltaic modules and energy storage containers into a physical setting, and prevents photovoltaic modules from being placed on the top of the container through brackets, such as Figure 3 As shown, the space of the energy storage container can be well utilized, effectively saving the floor space of the container energy storage system. The photovoltaic module is a slope design structure, which can reduce the risk of water and snow accumulation on the top. Placing the photovoltaic module on the energy storage container can not only reduce the use of the occupied area, but also the top of the energy storage container is affected by the solar radiation. Due to the difference in the three-dimensional temperature field, the temperature of the top is about 2°C higher than the temperature of other parts on average. After placing the photovoltaic circuit board on the top, it can absorb the heat of solar radiation, prevent the sun from directly shining on the container battery system, reduce the heat infiltration from the outside of the container, reduce the temperature of the battery cells in the container, reduce the energy consumption of the battery temperature management system, and increase the service life of the battery system.

[0066] In addition, the bracket of the photovoltaic module also has a retractable function. For example, when the light intensity is >1000W / m 2 , and the ambient temperature is >25℃, the photovoltaic modules on the top of the energy storage box can be spread out to increase the collection capacity of the photovoltaic modules and improve energy collection; when the light intensity is <1000W / m 2 Or when the ambient temperature is less than 25℃, collect the sagging photovoltaic panels.

[0067] The photovoltaic module is used as the energy source of the battery energy storage unit participating in the grid regulation. The electric energy generated by the photovoltaic module is converted by the first DC / DC converter and then charged to the battery energy storage unit, so that the power of the battery energy storage unit is sufficient to participate in the grid regulation and improve the energy utilization rate. When the power generation power of the photovoltaic module can still meet the power demand of the AC load, the second DC power output by the first DC / DC converter is converted by the second DC / AC converter to output the second AC power to power the AC load, so as to maximize the use of energy and reduce the energy consumption of the system.

[0068] In some embodiments, the power distribution device of the container energy storage system is integrated in the container and pre-connected to the electrical equipment through a wiring harness. It is only necessary to reserve an interface for connection with the photovoltaic module, which can reduce external wiring harness connections and facilitate installation and debugging.

[0069] Photovoltaic power generation is unstable and volatile. When photovoltaic power generation is insufficient, the electrical equipment in the container still needs to operate normally. Therefore, a control unit needs to be set up in the system to collect the power generation power of the photovoltaic components, the power of the battery energy storage unit and the power demand of the power grid in real time, and to determine in real time whether the power of the battery energy storage unit can meet the power demand of the power grid. When the power demand of the power grid cannot be met, the photovoltaic components will charge the battery energy storage unit so that the battery energy storage unit can meet the regulation of the power grid.

[0070] In summary, in the technical solution of the embodiment of the present application, the first power conversion unit is suitable for connecting to the power generation unit and converting the power output by the power generation unit to charge the battery energy storage unit in the container energy storage system; the second power conversion unit is suitable for connecting to the battery energy storage unit and converting the power output by the battery energy storage unit to discharge to the power grid; the control unit is configured to control the first power conversion unit to charge the battery energy storage unit when receiving the discharge instruction from the power grid, if the power of the battery energy storage unit does not meet the power demand of the power grid, and control the second power conversion unit to output power to discharge to the power grid when the power of the battery energy storage unit meets the power demand of the power grid. Thereby, the power generated by the power generation unit is stored in the energy storage battery unit, and the energy storage battery unit participates in the power regulation of the power grid to improve energy utilization.

[0071] Corresponding to the above embodiment, the embodiment of the present application further proposes a power distribution method for a container energy storage system.

[0072] In some embodiments, the container energy storage system includes a first power conversion unit and a second power conversion unit. The first power conversion unit is suitable for connecting to a power generation unit and converting the power output by the power generation unit to charge a battery energy storage unit in the container energy storage system. The second power conversion unit is suitable for connecting to a battery energy storage unit and converting the power output by the battery energy storage unit to discharge to a power grid.

[0073] like Figure 4 As shown, the power distribution method of the container energy storage system in the embodiment of the present application may include the following steps:

[0074] S1, upon receiving a discharge instruction from the power grid, obtaining the power of the battery energy storage unit and the power demand of the power grid, wherein the discharge instruction of the power grid includes the power demand of the power grid.

[0075] S2, when the power of the battery energy storage unit does not meet the power demand of the power grid, control the first power conversion unit to charge the battery energy storage unit, and when the power of the battery energy storage unit meets the power demand of the power grid, control the second power conversion unit to output electric energy to discharge to the power grid.

[0076] Specifically, when the energy storage power station needs the battery energy storage unit to discharge and participate in the peak and frequency regulation characteristics of the power grid, the electric energy generated by the power generation unit is used to charge the battery energy storage unit first, so that the battery energy storage unit has enough power to participate in the regulation of the power grid. When the discharge instruction of the power grid is received, the power of the battery energy storage unit and the power demand of the power grid are obtained, and then the battery energy storage unit and the second power conversion unit are controlled according to the relationship between the power of the battery energy storage unit and the power demand of the power grid. For example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, the first power conversion unit can be controlled to convert the power output by the power generation unit, and the battery energy storage unit can be charged first until the power of the battery energy storage unit meets the power demand of the power grid, and the battery energy storage unit outputs power, and the second power conversion unit converts the power output by the battery energy storage unit to discharge to the power grid. For another example, the power generation unit may include at least one of a photovoltaic module and a wind power module. Due to the instability and volatility of the power generation unit, taking the photovoltaic module as an example, when the power of the battery energy storage unit cannot meet the power demand of the power grid, if the light and temperature of the external environment are not good, the battery energy storage unit can be controlled to output electric energy first, and the second electric energy conversion unit converts the electric energy output by the battery energy storage unit to discharge to the power grid. For the insufficient part, the first electric energy conversion unit is controlled to convert the electric energy output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can make up for the insufficient part. Thus, the electric energy generated by the power generation unit is stored in the energy storage battery unit, and the energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy. For another example, when the power of the battery energy storage unit can meet the power demand of the power grid, the battery energy storage unit is controlled to output electric energy, and the second electric energy conversion unit converts the electric energy output by the battery energy storage unit, and the converted electric energy is discharged to the power grid.

[0077] In some embodiments, the second power conversion unit includes a first DC / AC converter, and the first DC / AC converter is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current. The method also includes: when the power of the battery energy storage unit does not meet the power demand of the power grid, controlling the first DC / AC converter to output the first alternating current to discharge to the power grid, and when the power of the battery energy storage unit decreases to a preset power threshold, controlling the first power conversion unit to output electric energy to charge the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid. The preset power threshold can be calibrated according to actual conditions, for example, the preset power threshold can be 0.

[0078] Specifically, when receiving a discharge instruction from the power grid, if the power of the battery energy storage unit does not meet the power demand of the power grid, the battery energy storage unit is first controlled to output electric energy to discharge the power grid. Since the electric energy output by the battery energy storage unit cannot directly meet the power supply voltage of the power grid, it is necessary to convert the direct current output by the battery energy storage unit through the first DC / AC converter to output the first alternating current to discharge to the power grid, so that the electric energy generated by the power generation unit can participate in the power regulation of the power grid and improve energy utilization. After the power of the battery energy storage unit is discharged, the first electric energy conversion unit is controlled to convert the electric energy output by the power generation unit to charge the battery energy storage unit until the power of the battery energy storage unit can meet the power demand of the power grid. For example, if the power demand of the power grid is 1000W, and the power of the battery energy storage unit can only provide 700W of power, then after the battery energy storage unit is discharged, the power output by the first power conversion unit is used to charge the battery energy storage unit. When the power of the battery energy storage unit can provide the remaining 300W of power, the charging is stopped, and the power output of the battery energy storage unit is controlled. The direct current output by the battery energy storage unit is converted by the first DC / AC converter to output the first alternating current and discharge to the power grid. In this way, the power generated by the power generation unit is used to charge the battery energy storage unit first, without affecting the battery energy storage unit's participation in the regulation of the power grid.

[0079] In some embodiments, the first power conversion unit includes a first DC / DC converter, which is suitable for converting the direct current output by the power generation unit to output a first direct current. The method also includes: when the power of the battery energy storage unit cannot meet the power requirement of the power grid, controlling the first DC / DC converter to output the first direct current to charge the battery energy storage unit, until the power of the battery energy storage unit meets the power requirement of the power grid, controlling the second power conversion unit to output electric energy to discharge to the power grid.

[0080] Specifically, when receiving the discharge instruction from the power grid, first determine whether the power of the battery energy storage unit can meet the power demand of the power grid. If the power of the battery energy storage unit cannot meet the power demand of the power grid, the battery energy storage unit can be charged through the power generation unit first. For example, the first DC / DC converter is controlled to convert the electric energy output by the power generation unit to output the first direct current to charge the battery energy storage unit. In the process of charging the battery energy storage unit, the power of the battery energy storage unit is obtained in real time. When the power of the battery energy storage unit can meet the power demand of the power grid, the first DC / DC converter is controlled to stop outputting the first direct current. Then the second power conversion unit (i.e., the first DC / AC converter) is controlled to convert the electric energy output by the battery energy storage unit to output the first alternating current to discharge to the power grid.

[0081] In some embodiments, the first power conversion unit includes a second DC / AC converter, which is suitable for converting the second direct current output by the first DC / AC converter to output a second alternating current, and also includes: when the power of the battery energy storage unit meets the power demand of the power grid, if the power generation power of the power generation unit is greater than or equal to the power demand of the AC load, then the second DC / AC converter is controlled to output the second alternating current to power the AC load; if the power generation power of the power generation unit is less than the power demand of the AC load, then the first DC / DC converter is controlled to output the first direct current to charge the battery energy storage unit.

[0082] Specifically, when the power generation power of the power generation unit is relatively large, the power demand of the AC load is also obtained while the power of the battery energy storage unit can meet the power demand of the power grid. Among them, when the power generation power of the power generation unit can meet the power demand of the AC load, it can also supply power to the AC load. The AC load generally includes a water cooling unit, etc., and its power supply voltage is a relatively large AC voltage. Therefore, it is necessary to control the second DC / AC converter to convert the second direct current output by the first DC / DC converter to output the second alternating current to supply power to the AC load, thereby improving energy utilization and reducing the power consumption of the system auxiliary power supply.

[0083] When the power generated by the power generation unit cannot meet the power demand of the AC load, the auxiliary power supply can be controlled to supply power to the AC load to enable the normal operation of the equipment. In addition, in order to make full use of energy, the electric energy generated by the power generation unit is converted into the electric energy of the battery energy storage unit, that is, the first DC / DC converter is controlled to convert the electric energy output by the power generation unit into the first direct current to charge the battery energy storage unit, thereby minimizing the abandoned light and improving the energy utilization rate.

[0084] In some embodiments, the container energy storage system also includes a third power conversion unit, which is suitable for connecting to an auxiliary power supply and converting the power provided by the auxiliary power supply to power a target DC load, and the power supply voltage of the target DC load is less than a first preset voltage. The method also includes: according to the required power of the target DC load, controlling the third power conversion unit to output power to power the target DC load.

[0085] That is to say, an auxiliary power supply is used to supply power to the target DC load (low-voltage DC load). At the same time, when the power generation power of the power generation unit cannot meet the required power of the AC load, the auxiliary power supply is controlled to directly supply power to the AC load to maintain the normal operation of the electrical equipment.

[0086] In some embodiments, the third power conversion unit may include a first AC / DC converter, which is suitable for converting the power provided by the auxiliary power supply to output a third direct current. The above method also includes: controlling the first AC / DC converter to output the third direct current to power the target DC load according to the required power of the target DC load.

[0087] Specifically, since the electric energy provided by the auxiliary power supply is AC power, it is necessary to convert the AC power into DC power before supplying power to the target DC load. The AC power provided by the auxiliary power supply can be converted by a first AC / DC converter to output a third DC power to supply power to the target DC load, wherein the power supply voltage of the target DC load is generally 12V / 24V.

[0088] As an example, Figure 5 As shown, the power distribution method of the container energy storage system of the present invention may include the following steps:

[0089] S101, receiving a discharge instruction from a power grid.

[0090] S102, obtaining the power of the battery energy storage unit.

[0091] S103, determine whether the power of the battery energy storage unit meets the power demand of the power grid. If yes, execute step S104; if not, execute step S105.

[0092] S104: Control the first DC / AC converter to output a first alternating current to discharge to a power grid.

[0093] S105, controlling the first DC / DC converter to output a first direct current to charge the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid.

[0094] S106, judging whether the power generated by the power generation unit can meet the power demand of the AC load. If yes, executing step S107; if no, executing step S108.

[0095] S107, controlling the second DC / AC converter to output a second alternating current to supply power to the AC load.

[0096] S108, controlling the first DC / DC converter to output a first direct current to charge the battery energy storage unit.

[0097] It should be noted that the above example takes the example of first determining whether the power of the battery energy storage unit can meet the power demand of the power grid. It is also possible to first discharge to the power grid when receiving the discharge instruction from the power grid, and then determine whether the discharge amount meets the power demand of the power grid after the battery energy storage unit is discharged. This will not be described in detail here.

[0098] In addition, for details not disclosed in the power distribution method of the container energy storage system in the embodiment of the present application, please refer to the details disclosed in the power distribution device of the container energy storage system in the embodiment of the present application, and the details will not be repeated here.

[0099] In summary, in the power supply method of the container energy storage system of some embodiments of the present application, when a discharge instruction from the power grid is received, when the power of the battery energy storage unit does not meet the power requirement of the power grid, the control unit controls the first power conversion unit to preferentially charge the battery energy storage unit, and when the power of the battery energy storage unit meets the power requirement of the power grid, controls the second power conversion unit to output electric energy to discharge to the power grid, and stores the electric energy generated by the power generation unit in the energy storage battery unit. The energy storage battery unit participates in the power regulation of the power grid, thereby improving the utilization rate of the system energy.

[0100] Corresponding to the above embodiments, the present application also proposes a container energy storage system.

[0101] like Figure 6 As shown, the container energy storage system 100 of some embodiments of the present application includes a power generation unit 130 and the power distribution device 140 of the container energy storage system described above.

[0102] In some embodiments, the power generation unit 130 may include at least one of a photovoltaic power generation component and a wind power generation component.

[0103] For details not disclosed in the container energy storage system of some embodiments of the present application, please refer to the details disclosed in the distribution device of the container energy storage system of some embodiments of the present application, and the details will not be repeated here.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A power distribution device for a container energy storage system, characterized in that: include: A first electric energy conversion unit, wherein the first electric energy conversion unit is adapted to be connected to a power generation unit and to convert electric energy output by the power generation unit to charge a battery energy storage unit in the container energy storage system; a second electric energy conversion unit, the second electric energy conversion unit being adapted to be connected to the battery energy storage unit and to convert the electric energy output by the battery energy storage unit so as to discharge to the power grid; The control unit is configured to, upon receiving a discharge instruction from the power grid, control the first power conversion unit to charge the battery energy storage unit when the power of the battery energy storage unit does not meet the power demand of the power grid, and control the second power conversion unit to output electric energy to discharge the power grid when the power of the battery energy storage unit meets the power demand of the power grid, wherein the discharge instruction of the power grid includes the power demand of the power grid.

2. The power distribution device according to claim 1, characterized in that: The second power conversion unit includes a first DC / AC converter, and the first DC / AC converter is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current, wherein the control unit is further configured to: When the power of the battery energy storage unit does not meet the power demand of the power grid, the first DC / AC converter is controlled to output the first alternating current to discharge the power grid, and when the power of the battery energy storage unit is reduced to a preset power threshold, the first power conversion unit is controlled to output electric energy to charge the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid.

3. The power distribution device according to claim 1, characterized in that: The first power conversion unit includes a first DC / DC converter, and the first DC / DC converter is suitable for converting the direct current output by the power generation unit to output a first direct current, wherein the control unit is further configured to: When the power of the battery energy storage unit does not meet the power requirement of the power grid, the first DC / DC converter is controlled to output the first direct current to charge the battery energy storage unit. When the power of the battery energy storage unit meets the power requirement of the power grid, the second power conversion unit is controlled to output electric energy to discharge the power grid.

4. The power distribution device according to claim 3, characterized in that: The first power conversion unit includes a second DC / AC converter, and the second DC / AC converter is suitable for converting the second direct current output by the first DC / DC converter to output a second alternating current, wherein the control unit is further configured to: When the power of the battery energy storage unit meets the power demand of the power grid, if the power generation power of the power generation unit is greater than or equal to the power demand of the AC load, the second DC / AC converter is controlled to output a second AC power to power the AC load.

5. The power distribution device according to claim 4, characterized in that: The control unit is further configured to control the first DC / DC converter to output the first direct current to charge the battery energy storage unit when the power generation power of the power generation unit is less than the required power of the AC load.

6. The power distribution device according to claim 1, characterized in that: Also includes: a third power conversion unit, the third power conversion unit being adapted to be connected to an auxiliary power supply and converting power provided by the auxiliary power supply to supply power to a target DC load in the container energy storage system, wherein a supply voltage of the target DC load is less than a first preset voltage; The control unit is further configured to control the third power conversion unit to output electric energy according to the required power of the target DC load, so as to supply power to the target DC load.

7. The power distribution device according to claim 6, characterized in that: The third power conversion unit includes a first AC / DC converter, and the first AC / DC converter is suitable for converting the power provided by the auxiliary power supply to output a third direct current, wherein the control unit is further configured to: According to the required power of the target DC load, the first AC / DC converter is controlled to output the third DC power to supply power to the target DC load.

8. The power distribution device according to claim 6, characterized in that: The control unit includes at least one of an EMS controller of the power grid, a controller of the first power conversion unit, a controller of the second power conversion unit, and a controller of the third power conversion unit.

9. A power distribution method for a container energy storage system, characterized in that: The container energy storage system comprises a first power conversion unit and a second power conversion unit, wherein the first power conversion unit is adapted to be connected to a power generation unit and convert the power outputted by the power generation unit to charge a battery energy storage unit in the container energy storage system, and the second power conversion unit is adapted to be connected to the battery energy storage unit and convert the power outputted by the battery energy storage unit to discharge to a power grid, and the method comprises: Upon receiving a discharge instruction from the power grid, acquiring the power of the battery energy storage unit and the power demand of the power grid, wherein the discharge instruction from the power grid includes the power demand of the power grid; When the power of the battery energy storage unit does not meet the power demand of the power grid, the first power conversion unit is controlled to charge the battery energy storage unit; and when the power of the battery energy storage unit meets the power demand of the power grid, the second power conversion unit is controlled to output electric energy to discharge to the power grid.

10. The power distribution method according to claim 9, characterized in that: The second power conversion unit includes a first DC / AC converter, and the first DC / AC converter is suitable for converting the direct current output by the battery energy storage unit to output a first alternating current. The method also includes: When the power of the battery energy storage unit does not meet the power demand of the power grid, the first DC / AC converter is controlled to output the first alternating current to discharge the power grid, and when the power of the battery energy storage unit is reduced to a preset power threshold, the first power conversion unit is controlled to output electric energy to charge the battery energy storage unit until the power of the battery energy storage unit meets the power demand of the power grid.

11. The power distribution method according to claim 9, characterized in that: The first power conversion unit includes a first DC / DC converter, and the first DC / DC converter is suitable for converting the direct current output by the power generation unit to output a first direct current. The method further includes: When the power of the battery energy storage unit cannot meet the power demand of the power grid, the first DC / DC converter is controlled to output the first direct current to charge the battery energy storage unit. When the power of the battery energy storage unit meets the power demand of the power grid, the second power conversion unit is controlled to output electric energy to discharge the power grid.

12. The power distribution method according to claim 11, characterized in that: The first power conversion unit includes a second DC / AC converter, the second DC / AC converter is suitable for converting the second direct current output by the first DC / DC converter to output a second alternating current, and further includes: When the power of the battery energy storage unit meets the power requirement of the power grid, if the power generation power of the power generation unit is greater than or equal to the power requirement of the AC load, control the second DC / AC converter to output a second AC power to supply power to the AC load; If the power generated by the power generation unit is less than the power required by the AC load, the first DC / DC converter is controlled to output the first direct current to charge the battery energy storage unit.

13. The power distribution method according to claim 9, characterized in that: The container energy storage system further includes a third power conversion unit, which is adapted to be connected to an auxiliary power supply and convert the power provided by the auxiliary power supply to supply power to a target DC load, wherein the power supply voltage of the target DC load is less than a first preset voltage, and the method further includes: According to the required power of the target DC load, the third power conversion unit is controlled to output electric energy to supply power to the target DC load.

14. A container energy storage system, characterized in that: include: A power generation unit and a power distribution device of a container energy storage system as claimed in any one of claims 1 to 8.

15. The container energy storage system according to claim 14, characterized in that: The power generation unit includes at least one of a photovoltaic power generation component and a wind power generation component.

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