Marine energy storage system and charging method thereof

Abstract

The embodiment of the invention discloses a marine energy storage system and a charging method thereof. The charging method of the marine energy storage system comprises the following steps: receiving a charging instruction for charging the marine energy storage system; obtaining the branch voltage of each power supply branch; determining a power-on strategy of the power supply branch according to the branch voltage, and closing a charging switch in the second high-voltage box according to the power-on strategy so as to power on the power supply branch; and if all the power supply branches are electrified, a charging switch in the first high-voltage box is closed, so that the battery pack in each power supply branch is charged through the first high-voltage box, the voltage consistency of each power supply branch in the charging stage can be ensured, and the problem that the power supply branches cannot be charged after the marine energy storage system is charged is avoided. Therefore, the problem that the consistency of the voltage between the power supply branches is poor is solved, and the reliability and the safety of the marine energy storage system are greatly improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a marine energy storage system and a charging method thereof. Background Art

[0002] With the maturity of electric propulsion technology, all-electric ships have become the main direction of future ship design. In this context, as an important part of modern ship design, the ship energy storage system has gradually developed from auxiliary load energy supply to energy supply for multiple types of ship loads, especially as an important part of the ship power system, it cooperates with various types of ship main / auxiliary engines to improve the economic / environmental characteristics of the ship while meeting the various load requirements of the ship. However, the existing ship energy storage system usually follows the architecture of the land-based energy storage system, which is not optimized for the actual use environment of the ship, resulting in poor reliability of the ship energy storage system. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present application provides a ship energy storage system and a charging method thereof, aiming to solve the technical problem of poor reliability of ship energy storage systems in the prior art.

[0004] In order to solve the above problems, in the first aspect, the present application provides a charging method for a marine energy storage system, wherein the marine energy storage system comprises a plurality of power supply branches and a first high-voltage box, wherein the plurality of power supply branches are connected in parallel, each power supply branch comprises at least one battery pack and a second high-voltage box, and the first high-voltage box is provided with a charging and discharging interface, and the first high-voltage box is electrically connected to the second high-voltage box; the charging method comprises:

[0005] receiving a charging instruction for charging the marine energy storage system;

[0006] Obtaining the branch voltage of each power supply branch;

[0007] Determine a power-on strategy for the power supply branch according to the branch voltage, and close the charging switch in the second high-voltage box according to the power-on strategy to power on the power supply branch;

[0008] If all power supply branches are powered on, the charging switch in the first high-voltage box is closed to charge the battery pack in each power supply branch through the first high-voltage box.

[0009] In a second aspect, the present application further provides a marine energy storage system, which includes a plurality of power supply branches and a first high-voltage box, wherein the power supply branches include:

[0010] at least one battery pack;

[0011] A second high-voltage box, one end of which is electrically connected to the battery pack;

[0012] Among them, the first high-voltage box is provided with a charging and discharging interface, one end of the charging and discharging interface is electrically connected to the other end of the second high-voltage box, and the other end of the charging and discharging interface is electrically connected to the ship power distribution system and / or the charging and discharging device.

[0013] The present application provides a charging method for a marine energy storage system. After receiving a charging instruction to charge the marine energy storage system, the method determines a power-on strategy for the power supply branch by obtaining the branch voltage of each power supply branch, so as to ensure the voltage consistency of each power supply branch during the charging stage, thereby avoiding the problem of poor voltage consistency between the power supply branches after the marine energy storage system is charged, and greatly improving the reliability and safety of the marine energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A first schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0016] Figure 2 A second schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0017] Figure 3 A third schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0018] Figure 4 A fourth schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0019] Figure 5 A fifth schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0020] Figure 6 A sixth schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0021] Figure 7 A seventh schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0022] Figure 8 An eighth schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0023] Fig. 9 A ninth schematic block diagram of a marine energy storage system provided in an embodiment of the present application;

[0024] Fig.10A schematic flow chart of a charging method for a marine energy storage system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0027] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0028] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0029] In addition, in this application, unless otherwise clearly specified or limited in the embodiments, the terms "installed", "connected", "connected" and "fixed" etc. appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integrated connection. It can be understood that it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements, or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific implementation situation.

[0030] The embodiments of the present application provide a marine energy storage system and a charging method thereof.

[0031] For ease of understanding, the ship energy storage system is first introduced, and the charging method of the ship energy storage system is introduced in detail based on the ship energy storage system. Among them, the ship energy storage system can be a three-level energy storage system or a two-level energy storage system. When the ship energy storage system is a two-level energy storage system, the ship energy storage system may include at least one power supply branch, and a second high-voltage box 100 may be provided in the power supply branch; when the ship energy storage system is a three-level energy storage system, the ship energy storage system may include at least one power supply branch and a first high-voltage box, and a second high-voltage box may be provided in the power supply branch.

[0032] See also Figure 1 , Figure 1 The first schematic block diagram of the marine energy storage system provided in the embodiment of the present application. Figure 1 As shown, the present application provides a marine energy storage system, which includes at least one power supply branch, and the power supply branch includes:

[0033] A second high-voltage box 100;

[0034] The energy storage device 200 is electrically connected to the second high-voltage box 100;

[0035] The second high-voltage box 100 is provided with a charging and discharging interface, which is electrically connected to a shipboard power distribution system or a charging and discharging device.

[0036] In this embodiment, the charging and discharging of the marine energy storage system are integrated into one interface, namely, the charging and discharging interface, which can be provided on the second high-voltage box 100. At the same time, the second high-voltage box 100 is also provided with a first interface 110 and a second interface 120, and the energy storage device 200 is provided with a positive battery electrode and a negative battery electrode, the positive battery electrode is electrically connected to the first interface 110, and the negative battery electrode is electrically connected to the second interface 120; the second high-voltage box 100 includes a first switch circuit 170 and a second switch circuit 180, and the charging and discharging interface includes a charging and discharging positive electrode 101 and a charging and discharging negative electrode 102, the first switch circuit 170 is provided between the first interface 110 and the charging and discharging positive electrode, and the second switch circuit 180 is provided between the second interface 120 and the charging and discharging negative electrode, and the first switch circuit 170 and the second switch circuit 180 are both provided with a switch for controlling the on-off of the main circuit of the power supply branch, and the switch can be a relay.

[0037] The ship can adopt the ship energy storage system mentioned in the above embodiment. When the ship energy storage system needs to be charged, the ship energy storage system needs to be separated from the ship, that is, the charging and discharging interface is separated from the ship power distribution system, and electrically connected to the charging and discharging device to realize charging of the ship energy storage system.

[0038] When the marine energy storage system is separated from the ship and electrically connected to the charging and discharging device, the second switch circuit 180 can be turned on first, and then the first switch circuit 170 can be turned on to complete the power supply branch. After the power supply branch is powered on, the battery pack 201 in the power supply branch can be charged.

[0039] See also Figure 2 , Figure 2 This is a second schematic block diagram of a marine energy storage system provided in an embodiment of the present application. Figure 2 As shown, the present application provides a marine energy storage system, which includes at least one power supply branch, and the power supply branch includes:

[0040] The second high-voltage box 100 is provided with a first interface 110 and a second interface 120;

[0041] The energy storage device 200 is provided with a positive battery electrode and a negative battery electrode, wherein the positive battery electrode is electrically connected to the first interface 110 and the negative battery electrode is electrically connected to the second interface 120;

[0042] The second high-voltage box 100 is also provided with a charging and discharging interface, which includes a charging interface 160 and a discharging interface 150 . The charging interface 160 is electrically connected to the charging and discharging device, and the discharging interface 150 is electrically connected to the ship's power distribution system.

[0043] In this embodiment, the ship energy storage system can be a ship container energy storage system, which includes at least one power supply branch, in which a second high-voltage box 100 and an energy storage device 200 are provided, and a charging interface 160 and a discharging interface 150 are separately provided on the second high-voltage box 100. The charging interface 160 is electrically connected to the charging and discharging device to charge the power supply branch on the energy storage system, and the discharging interface 150 is electrically connected to the ship power distribution system to distribute the electric energy output by the power supply branch for use by the ship, thereby achieving better independent control and protection of the battery charging and discharging process, and greatly improving the safety and reliability of the ship energy storage system.

[0044] At the same time, the ship energy storage system provided in the present application may include multiple power supply branches, each power supply branch is provided with a second high-voltage box 100 and an energy storage device 200, and the second high-voltage box 100 is separately provided with a charging interface 160 and a discharging interface 150. After the power supply branches are connected in parallel, the multiple charging interfaces 160 on each second high-voltage box 100 can be integrated into an interface for charging, and the multiple discharge interfaces 150 on each second high-voltage box 100 can be integrated into an interface for discharging.

[0045] Specifically, the marine energy storage system mentioned in the present application is a two-level structure energy storage system, which can also be expanded to a three-level structure energy storage system. When it is expanded to a three-level structure energy storage system, a junction cabinet can be connected to the rear end of the second high-voltage box 100, and the circuit inside the junction cabinet can be designed to be similar to the circuit inside the second high-voltage box 100, thereby realizing a three-level structure marine energy storage system.

[0046] The energy storage device 200 mentioned in the present application may include multiple battery packs 201, and multiple battery packs 201 are connected in series to form a battery cluster of a marine energy storage system. The present application sets multiple battery packs 201 in each power supply branch, and each battery pack 201 is connected in series, and a fuse or / and a relay can also be connected in series, which can not only increase the voltage of the power supply branch, but also enhance the safety performance of the power supply branch. In addition, when the energy storage device 200 may include multiple battery packs 201, multiple battery packs 201 can also be connected in parallel to form a battery cluster of a marine energy storage system.

[0047] At the same time, each battery pack 201 may also include a fuse and at least one battery cell. The fuse and the at least one battery cell are connected in series and are respectively connected to the input and output ends of the battery pack 201, or each battery pack 201 includes at least one fuse and at least one battery cell. The fuse and the battery cell are connected in series one by one and are respectively electrically connected to the input and output ends to achieve parallel connection. Therefore, when a short circuit occurs in the battery pack 201, a second fuse can be used to promptly cut off the circuit where the battery pack 201 is located to ensure the safety of the battery pack 201.

[0048] The marine energy storage system provided in the present application includes at least one power supply branch, which includes a second high-voltage box 100 and an energy storage device 200. The high-voltage box 100 is provided with a first interface 110, a second interface 120, a charging interface 160 and a discharging interface 150. The energy storage device 200 is provided with a battery positive electrode and a battery negative electrode. The battery positive electrode is electrically connected to the first interface 110, the battery negative electrode is electrically connected to the second interface 120, the charging interface 160 is electrically connected to the charging and discharging device, and the discharging interface 150 is electrically connected to the marine power distribution system, thereby realizing the separation of the charging interface 160 and the discharging interface 150 of the marine energy storage system, thereby better realizing independent control and protection of the battery charging and discharging process, and at the same time, when the marine energy storage system needs to be charged, it is possible to avoid separating the marine energy storage system from the ship, thereby greatly improving the safety, reliability and practicality of the marine energy storage system.

[0049] In some embodiments, Figure 3As shown, the second high-voltage box 100 includes a first switch circuit 170 and a second switch circuit 180, the charging interface 160 includes a charging positive electrode 161 and a charging negative electrode 162, and the discharging interface 150 includes a discharging positive electrode 151 and a discharging negative electrode 152; wherein, one end of the first switch circuit 170 is electrically connected to the first interface 110, and the other end of the first switch circuit 170 is electrically connected to the charging positive electrode 161 and the discharging positive electrode 151 respectively; one end of the second switch circuit 180 is electrically connected to the second interface 120, and the other end of the second switch circuit 180 is electrically connected to the charging negative electrode 162 and the discharging negative electrode 152 respectively.

[0050] In this embodiment, by setting the first switch circuit 170 and the second switch circuit 180 in the first high-voltage box 100, the discharge positive electrode 151 of the discharge interface 150 and the charging positive electrode 161 of the charging interface 160 are both electrically connected to the first interface 110 through the first switch circuit 170 to realize the electrical connection with the battery positive electrode of the energy storage device 200; the discharge negative electrode 152 of the discharge interface 150 and the charging negative electrode 162 of the charging interface 160 are both electrically connected to the second interface 120 through the second switch circuit 180 to realize the electrical connection with the battery negative electrode of the energy storage device 200, so that when the marine energy storage system needs to be discharged, the first switch circuit 1 The first switch circuit 170 and the second switch circuit 180 respectively disconnect the path between the charging positive electrode 161 and the first interface 110 and the path between the charging negative electrode 162 and the second interface 120 to ensure the normal discharge of the marine energy storage system; when the marine energy storage system needs to be charged, the first switch circuit 170 and the second switch circuit 180 respectively disconnect the path between the discharge positive electrode 151 and the first interface 110 and the path between the discharge negative electrode 152 and the second interface 120 to ensure the normal charging of the marine energy storage system, thereby better realizing independent control and protection of the battery charging and discharging process, greatly improving the safety and reliability of the marine energy storage system.

[0051] Furthermore, in some embodiments, Figure 3 As shown, the first switch circuit 170 includes a first discharge switch 171 and a first charging switch 172; wherein, one end of the first discharge switch 171 and one end of the first charging switch 172 are both electrically connected to the first interface 110, the other end of the first discharge switch 171 is electrically connected to the discharge positive electrode 151, and the other end of the first charging switch 172 is electrically connected to the charging positive electrode 161.

[0052] In this embodiment, the on and off of the first discharge switch 171 and the first charging switch 172 can be controlled by the battery management system of the marine energy storage system, and the first discharge switch 171 and the first charging switch 172 can both be relays.

[0053] Among them, the battery management system is responsible for the battery charge and discharge management, status monitoring and analysis, power management and protection of the marine energy storage system. Specifically, the battery management system can prevent the battery of the marine energy storage system from being overcharged, over-discharged, overheated, etc. through systematic management, thereby improving the battery performance and service life of the marine energy storage system.

[0054] At the same time, in marine energy storage systems, the battery management system usually includes a domain management unit, a cluster management unit, a module management unit and a safety module, which can then communicate with the integrated control system to achieve more efficient battery management. In addition, the battery management system can also adopt a modular design and can be expanded according to the battery composition to adapt to different application scenarios.

[0055] Furthermore, in some embodiments, Figure 3 As shown, the second switch circuit 180 includes a second discharge switch 181 and a second charge switch 182; wherein, one end of the second discharge switch 181 and one end of the second charge switch 182 are both electrically connected to the second interface 120, the other end of the second discharge switch 181 is electrically connected to the discharge cathode 152, and the other end of the second charge switch 182 is electrically connected to the charge cathode 162.

[0056] In this embodiment, the on and off of the second discharge switch 181 and the second charging switch 182 can be controlled by the battery management system of the marine energy storage system, and the second discharge switch 181 and the second charging switch 182 can both be relays.

[0057] In addition, the first discharge switch 171, the second discharge switch 181, the first charging switch 172 and the second charging switch 182 can also be controlled by the ship management system. The on-off control method of the first discharge switch 171, the second discharge switch 181, the first charging switch 172 and the second charging switch 182 mentioned in this application can be selected according to actual applications, and this application does not make specific limitations.

[0058] In some embodiments, Figure 4 As shown, the second high-voltage box 100 further includes a balancing circuit 190 ; wherein one end of the balancing circuit 190 is electrically connected to the first interface 110 , and the other end of the balancing circuit 190 is electrically connected to the discharge positive electrode 151 and / or the charging positive electrode 161 .

[0059] Since the voltage internal resistance of each battery cell in the marine energy storage system is different, the difference is more significant after the battery cells are integrated into a battery cluster. Therefore, before discharging, the marine energy storage system also needs to balance the batteries on each power supply branch to ensure voltage consistency between the power supply branches.

[0060] In this embodiment, a balancing circuit 190 can be set between the first interface 110 and the discharge positive electrode 151, so that when the marine energy storage system needs to discharge, the balancing circuit 190 can be used for balancing to ensure the voltage consistency between the power supply branches. At the same time, it can also avoid the impact current when the marine energy storage system is charged and discharged. Specifically, when the power supply branch is powered on, the main negative switch in the first high-voltage box 20, that is, the fourth switch 520, can be closed first, and then the balancing circuit 190 can be turned on. After a preset time, the main positive switch in the first high-voltage box 20, that is, the third switch 510, can be closed, and then the balancing circuit 190 can be disconnected, thereby significantly improving the startup performance and safety of the marine energy storage system.

[0061] Furthermore, in some embodiments, Figure 4 As shown, the balancing circuit 190 includes a balancing switch 191 and a balancing resistor 192; wherein one end of the balancing switch 191 is electrically connected to the first interface 110, the other end of the balancing switch 191 is electrically connected to one end of the balancing resistor 192, and the other end of the balancing resistor 192 is electrically connected to the discharge positive electrode 151.

[0062] In this embodiment, the on-off of the balancing switch 191 can be controlled by the battery management system, and the balancing switch 191 can be a relay. At the same time, the on-off of the balancing switch 191 can also be controlled by the ship management system. The on-off control of the balancing switch 191 can be selected according to the actual application, and this application does not make specific limitations.

[0063] In some embodiments, the energy storage device 200 and the second high-voltage box 100 communicate with each other using a communication interface.

[0064] In this embodiment, the energy storage device 200 may include a plurality of battery packs 201, each of which may be provided with a communication interface, and the communication interfaces between the battery packs 201 may be electrically connected for communication. At the same time, the second high-voltage box 100 may also be provided with a communication interface, and the communication interface between the battery pack 201 and the second high-voltage box 100 may be electrically connected for communication, and then the battery management system or the ship management system may manage the second high-voltage box 100 and the battery pack 201 through the communication interface of the battery pack 201 and the second high-voltage box 100, so as to better realize the independent control and protection of the battery charging and discharging process, and greatly improve the safety and reliability of the marine energy storage system.

[0065] In some embodiments, the charging and discharging device is a charger or a charging pile.

[0066] Specifically, a charger is a device used to provide electrical energy to a battery. It adopts high-frequency power supply technology and uses advanced intelligent dynamic adjustment charging technology. It has the characteristics of high charging efficiency, simple operation, light weight, and small size. Chargers are widely used in various fields, including electric vehicles, electric motorcycles, electric forklifts, etc. The charger mentioned in this application is mainly used in the field of ships, and it can be installed on ships. Charging piles are important infrastructure for providing electrical energy to electric vehicles, and their functions are similar to those of gas pumps at gas stations. The charging piles mentioned in this application are mainly used to provide electrical energy for ship energy storage systems.

[0067] In some embodiments, the discharge interface 150 is electrically connected to a shipboard power distribution system, which includes a DC / AC converter or an energy storage converter or a DC distribution board.

[0068] The shipboard power distribution system can be a part of the ship's electrical system. The switchboard in the shipboard power distribution system can be a main switchboard, an emergency switchboard, and other types of switchboards. Among them, the shipboard main switchboard can be used in various ship power stations to control, monitor and protect generator sets and distribution grids.

[0069] In this embodiment, a DC / AC converter, an energy storage converter and a DC distribution board can be arranged in a marine power distribution system. Among them, a DC / AC converter, also known as an inverter, is a device that converts direct current (DC) into alternating current (AC). The DC / AC converter mainly realizes the conversion of direct current to alternating current through power semiconductor devices (such as IGBT or MOSFET). The energy storage converter can control the charging and discharging process of the power supply branch and perform AC-DC conversion. At the same time, it can also directly supply power to AC loads without a power grid. A DC distribution board is a device for distributing and managing direct current power, which is widely used in various industries, ships and new energy fields.

[0070] In some embodiments, in order to improve the safety performance of the marine energy storage system. Figure 5 As shown, the present application also provides a marine energy storage system, which includes at least one power supply branch 10 and a first high-voltage box 20; the power supply branch 10 includes:

[0071] The energy storage device 200 is provided with a positive battery electrode and a negative battery electrode;

[0072] The second high-voltage box 100 is provided with a first interface 110, a second interface 120, a third interface 130 and a fourth interface 140, the first interface 110 is electrically connected to the positive electrode of the battery, and the second interface 120 is electrically connected to the negative electrode of the battery;

[0073] Among them, the first high-voltage box 20 includes a third switch circuit 300, the first end of the third switch circuit 300 is electrically connected to the third interface 130, the second end of the third switch circuit 300 is electrically connected to the fourth interface 140, and the third end and the fourth end of the third switch circuit 300 are both electrically connected to the ship power distribution system.

[0074] In this embodiment, the ship energy storage system can be a ship container energy storage system, which includes at least one power supply branch 10 and a first high-voltage box 20. The power supply branch 10 is provided with a second high-voltage box 100 and an energy storage device 200. The energy storage device 200 is provided with a battery positive electrode and a battery negative electrode. The high-voltage box is provided with a first interface 110, a second interface 120, a third interface 130 and a fourth interface 140. The first interface 110 is electrically connected to the battery positive electrode, and the second interface 120 is electrically connected to the battery negative electrode. At the same time, a third switch circuit 300 is provided between the second high-voltage box 100 and the ship power distribution system, which not only realizes the monitoring and management of the high-voltage circuit of the ship energy storage system, but also realizes the three-level protection of the energy storage system, thereby improving the safety and reliability of the ship energy storage system.

[0075] Among them, the first high-voltage box 20 can be a group high-voltage box, the second high-voltage box 100 can be a cluster high-voltage box, and a power supply branch 10 can be understood as a battery cluster. A group high-voltage box generally refers to a high-voltage box used when multiple battery clusters are connected in parallel to form a battery stack. The group high-voltage box can be composed of a high-voltage power supply board (such as a DC / DC converter, a pre-charge module, a fuse, a sensor, a high-voltage acquisition and communication module), a main switch and a contactor. The main function of the group high-voltage box is to aggregate the outputs of multiple battery clusters and provide a unified high-voltage output interface. Group high-voltage boxes are often used in larger-scale energy storage systems, such as energy storage systems above 6MWh, which not only require different grouping methods, but also put forward higher requirements for the battery management system. The group high-voltage box can support the parallel connection of multiple clusters of batteries, thereby improving the overall efficiency and reliability of the system. At the same time, the group high-voltage box usually has a larger capacity and a higher voltage level, which is suitable for large-scale energy storage applications. Its design needs to take into account the parallel connection requirements of multiple clusters of batteries, as well as the corresponding heat dissipation and protection measures. In addition, the group high-voltage box also needs to have flexible customized design capabilities to adapt to different installation and wiring requirements.

[0076] The cluster high-voltage box is mainly used to manage the power circuit of the battery cluster. The cluster high-voltage box can integrate components such as circuit breakers, contactors, fuses, shunts, pre-charge circuits, switching power supplies, and battery cluster management modules, which together constitute a complete battery cluster management system responsible for the voltage acquisition, current acquisition, temperature monitoring, and data communication functions of the battery cluster. The cluster high-voltage box is usually used to connect a single or multiple battery clusters and connect them to energy storage inverters or other control devices. For example, in a large energy storage power station, a cluster high-voltage box can connect two battery clusters to achieve a two-input and two-output configuration. In addition, the cluster high-voltage box is also suitable for various energy storage scenarios, including source, grid, load, shared energy storage, etc. At the same time, the design of the cluster high-voltage box needs to consider factors such as explosion-proof, fire-proof, and anti-theft to ensure the safe operation of the system. Its internal structure is complex and integrates a variety of electronic controllers and sensors to achieve comprehensive management of the battery cluster.

[0077] The marine energy storage system provided in the present application includes at least one power supply branch 10 and a first high-voltage box 20, the power supply branch 10 includes an energy storage device 200 and a second high-voltage box 100, the energy storage device 200 is provided with a battery positive electrode and a battery negative electrode, the second high-voltage box 100 is provided with a first interface 110, a second interface 120, a third interface 130 and a fourth interface 140, the first interface 110 is electrically connected to the battery positive electrode, the second interface 120 is electrically connected to the battery negative electrode, the first high-voltage box 20 includes a third switch circuit 300, a first end of the third switch circuit 300 is electrically connected to the third interface 130, a second end of the third switch circuit 300 is electrically connected to the fourth interface 140, and the third end and the fourth end of the third switch circuit 300 are both electrically connected to the marine power distribution system, so that not only the high-voltage circuit of the marine energy storage system can be monitored and managed through the first high-voltage box 20, but also the third switch circuit 300 in the first high-voltage box 20 can be used to achieve three-level protection of the energy storage system, which greatly improves the safety and reliability of the marine energy storage system.

[0078] In some embodiments, Figure 6 and Figure 7 As shown, the third switch circuit 300 includes a first switch 310 and a second switch; wherein, one end of the first switch 310 is electrically connected to the third interface 130, and the other end of the first switch 310 is electrically connected to the ship power distribution system; one end of the second switch is electrically connected to the fourth interface 140, and the other end of the second switch is electrically connected to the ship power distribution system.

[0079] In this embodiment, the on and off of the first switch 310 and the second switch 320 can be controlled by a battery management system of the marine energy storage system, and the first switch 310 and the second switch 320 can both be relays.

[0080] Among them, the battery management system is responsible for the battery charge and discharge management, status monitoring and analysis, power management and protection of the marine energy storage system. Specifically, the battery management system can prevent the battery of the marine energy storage system from being overcharged, over-discharged, overheated, etc. through systematic management, thereby improving the battery performance and service life of the marine energy storage system.

[0081] At the same time, in marine energy storage systems, the battery management system usually includes a domain management unit, a cluster management unit, a module management unit and a safety module, which can then communicate with the integrated control system to achieve more efficient battery management. In addition, the battery management system can also adopt a modular design and can be expanded according to the battery composition to adapt to different application scenarios.

[0082] In some embodiments, the third switch circuit 300 includes an isolating switch; wherein a first end of the isolating switch is electrically connected to the third interface 130, a second end of the isolating switch is electrically connected to the fourth interface 140, and a third end and a fourth end of the isolating switch are both electrically connected to the ship power distribution system.

[0083] Specifically, an isolating switch is a switching device used to ensure safe isolation of circuits in electrical systems. Its main function is to physically disconnect the circuit to ensure that the circuit is completely de-energized during maintenance and repair to prevent electric shock or other dangers. When the isolating switch is in the open position, there is an insulation distance that meets the specified requirements and an obvious disconnection mark between the contacts; when it is in the closed position, it can carry the current under normal circuit conditions and the current under abnormal conditions (such as short circuit) within a specified time. In this embodiment, the on and off of the isolating switch can be controlled by the battery management system of the marine energy storage system, which can replace the first switch 310 and the second switch 320 mentioned in the above embodiment.

[0084] In some embodiments, Figure 7 As shown, the first high-voltage box 20 also includes a pre-charging circuit 400; wherein, one end of the pre-charging circuit 400 is electrically connected to the third interface 130 and the first end of the third switch circuit 300, respectively, and the other end of the pre-charging circuit 400 is electrically connected to the shipboard power distribution system and the second end of the third switch circuit 300, respectively.

[0085] In this embodiment, the pre-charging circuit 400 can prevent the inrush current from occurring during the charging and discharging of the marine energy storage system. Specifically, after the power supply branch 10 is powered on, pre-charging is performed through the pre-charging circuit 400. After pre-charging is completed, the third switch circuit 300 in the first high-voltage box 20 is turned on and the pre-charging circuit 400 is turned off, thereby significantly improving the startup performance and safety of the marine energy storage system.

[0086] Furthermore, in some embodiments, Figure 7As shown, the pre-charging circuit 400 includes a pre-charging switch 410 and a pre-charging resistor 420; wherein, one end of the pre-charging switch 410 is electrically connected to the third interface 130 and the first end of the third switch circuit 300, respectively, and the other end of the pre-charging switch 410 is electrically connected to one end of the pre-charging resistor 420, and the other end of the pre-charging resistor 420 is electrically connected to the ship power distribution system and the second end of the third switch circuit 300, respectively.

[0087] Specifically, after the power supply branch 10 is powered on, the main negative switch in the third switch circuit 300, that is, the second switch 320, can be closed first, and then the pre-charging switch 410 can be closed. After a preset time, that is, after the pre-charging is completed, the main positive switch in the third switch circuit 300, that is, the first switch 310, can be closed again, and then the pre-charging switch 410 can be disconnected to achieve normal power-on of the marine energy storage system.

[0088] In some embodiments, the first high-voltage box 20 is provided with a charging and discharging interface, which includes a charging and discharging positive electrode and a charging and discharging negative electrode; wherein, one end of the charging and discharging positive electrode is electrically connected to the third end of the third switching circuit 300 and the other end of the pre-charging circuit 400, respectively, and the other end of the charging and discharging positive electrode is electrically connected to the ship power distribution system; one end of the charging and discharging negative electrode is electrically connected to the fourth end of the third switching circuit 300, and the other end of the charging and discharging negative electrode is electrically connected to the ship power distribution system.

[0089] In some embodiments, Figure 8 and Fig. 9 As shown, the second high-voltage box 100 includes a fourth switch circuit 500; wherein, the first end of the fourth switch circuit 500 is electrically connected to the first interface 110, the second end of the fourth switch circuit 500 is electrically connected to the second interface 120, the third end of the fourth switch circuit 500 is electrically connected to the third interface 130, and the fourth end of the fourth switch circuit 500 is electrically connected to the fourth interface 140.

[0090] In this embodiment, the second high-voltage box 100 uses the fourth switch circuit 500 to control the on and off of the power supply branch 10 where the second high-voltage box 100 is located. When the main circuit of the power supply branch 10 needs to be disconnected, it can be achieved by disconnecting the fourth switch circuit 500; when the main circuit of the power supply branch 10 needs to be turned on, it can be achieved by turning on the fourth switch circuit 500.

[0091] Furthermore, in some embodiments, Figure 8 and Fig. 9 As shown, the fourth switch circuit 500 includes a third switch 510 and a fourth switch 520; wherein, one end of the third switch 510 is electrically connected to the first interface 110, and the other end of the third switch 510 is electrically connected to the third interface 130; one end of the fourth switch 520 is electrically connected to the second interface 120, and the other end of the fourth switch 520 is electrically connected to the fourth interface 140.

[0092] In this embodiment, the on and off of the third switch 510 and the fourth switch 520 can be controlled by a battery management system of the marine energy storage system, and the third switch 510 and the fourth switch 520 can both be relays.

[0093] In addition, the first switch 310, the second switch 320, the third switch 510 and the fourth switch 520 can also be controlled by the ship management system. The on-off control method of the first switch 310, the second switch 320, the third switch 510 and the fourth switch 520 mentioned in this application can be selected according to actual applications, and this application does not make specific limitations.

[0094] In some embodiments, Fig. 9 As shown, the second high-voltage box 100 also includes a balancing circuit 190; wherein one end of the balancing circuit 190 is electrically connected to the first interface 110 and the first end of the fourth switch circuit 500, and the other end of the balancing circuit 190 is electrically connected to the third interface 130 and the second end of the fourth switch circuit 500.

[0095] Since the voltage internal resistance of each battery cell in the marine energy storage system is different, the difference is more significant after the battery cells are integrated into a battery cluster. Therefore, before discharging, the marine energy storage system also needs to balance the batteries on each power supply branch 10 to ensure voltage consistency between the power supply branches 10.

[0096] In this embodiment, a balancing circuit 190 can be set between the positive electrode of the battery and the positive electrode 151 of the discharge, so that when the marine energy storage system needs to discharge, the balancing circuit 190 can be used for balancing to ensure the voltage consistency between the power supply branches 10. At the same time, it can also avoid the impact current when the marine energy storage system is charged and discharged. Specifically, when the power supply branch 10 is powered on, the main negative switch in the second high-voltage box 100, that is, the fourth switch 520, can be closed first, and then the balancing circuit 190 can be turned on. After a preset time, the main positive switch in the second high-voltage box 100, that is, the third switch 510, can be closed, and then the balancing circuit 190 can be disconnected, thereby significantly improving the startup performance and safety of the marine energy storage system.

[0097] Furthermore, in some embodiments, Fig. 9 As shown, the balancing circuit 190 includes a balancing switch 191 and a balancing resistor 192; wherein one end of the balancing switch 191 is electrically connected to the first interface 110 and the first end of the fourth switch circuit 500, respectively, the other end of the balancing switch 191 is electrically connected to one end of the balancing resistor 192, and the other end of the balancing resistor 192 is electrically connected to the third interface 130 and the second end of the fourth switch circuit 500, respectively.

[0098] In this embodiment, the on-off of the balancing switch 191 can be controlled by the battery management system, and the balancing switch 191 can be a relay. At the same time, the on-off of the balancing switch 191 can also be controlled by the ship management system. The on-off control of the balancing switch 191 can be selected according to the actual application, and this application does not make specific limitations.

[0099] In some embodiments, the energy storage device 200 , the first high-voltage box 20 , and the second high-voltage box 100 communicate with each other using their own communication interfaces.

[0100] In this embodiment, the energy storage device 200 may include a plurality of battery packs 201, each of which may be provided with a communication interface, and the communication interfaces between the battery packs 201 may be electrically connected for communication. At the same time, the first high-voltage box 20 and the second high-voltage box 100 are provided with communication interfaces, and the communication interfaces between the battery pack 201 and the second high-voltage box 100 and between the first high-voltage box 20 and the second high-voltage box 100 may also be electrically connected for communication, and then the battery management system or the ship management system may manage the first high-voltage box 20, the second high-voltage box 100 and the battery pack 201 through the communication interface of the battery pack 201 and the communication interface of the high-voltage box, which greatly improves the safety and reliability of the marine energy storage system.

[0101] In some embodiments, the third terminal and the fourth terminal of the third switch circuit 300 are both electrically connected to a shipboard power distribution system, and the shipboard power distribution system includes a DC / AC converter or an energy storage converter or a DC distribution board.

[0102] In this embodiment, the shipboard power distribution system may be a part of the ship's electrical system, and the switchboard in the shipboard power distribution system may be a main switchboard, an emergency switchboard, and other types of switchboards. Among them, the shipboard main switchboard may be applicable to various ship power stations to control, monitor and protect generator sets and distribution grids.

[0103] DC / AC converters, energy storage converters and DC distribution boards can be installed in the ship power distribution system. Among them, the DC / AC converter, also known as the inverter, is a device that converts direct current (DC) into alternating current (AC). The DC / AC converter mainly uses power semiconductor devices (such as IGBT or MOSFET) to realize the conversion of direct current to alternating current. The energy storage converter can control the charging and discharging process of the power supply branch 10 and perform AC-DC conversion. At the same time, it can also directly supply power to AC loads without a power grid. The DC distribution board is a device for distributing and managing direct current power, which is widely used in various industries, ships and new energy fields.

[0104] It can be understood that the marine energy storage system provided in the above embodiment is only an example. The marine energy storage system described in the embodiment of the present application is to more clearly illustrate the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided in the embodiment of the present application. It is known to those skilled in the art that with the evolution of the system and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems. The following are detailed descriptions.

[0105] It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments. The charging method of the marine energy storage system is described in detail below. At the same time, the charging method of the marine energy storage system provided in this application can be executed by a battery management system.

[0106] See also Fig.10 , Fig.10 A schematic diagram of a charging method for a marine energy storage system provided in an embodiment of the present application. Fig.10 As shown, the method includes steps S110 to S140.

[0107] S110: Receive a charging instruction for charging the marine energy storage system.

[0108] In this embodiment, the charging instruction is instruction information requesting charging of the ship energy storage system. The charging instruction can be issued by the ship management system, the automated manifest system, the planned maintenance system, the ship energy management system, etc. to the battery management system of the ship energy storage system.

[0109] In some embodiments, after receiving a charging instruction to charge the marine energy storage system and before obtaining the branch voltage of each power supply branch, it also includes: obtaining charging information of the marine energy storage system; and determining whether there is a separate charging interface and discharging interface for the charging and discharging interface based on the charging information; if there is a separate charging interface and discharging interface for the charging and discharging interface, obtaining the on-off information of the discharge switch corresponding to the discharge interface; if the on-off information shows that the discharge switch is in a closed state, disconnecting the discharge switch; closing the charging switch corresponding to the charging interface, and charging the battery pack in the power supply branch where the charging switch is located.

[0110] In this embodiment, the charging information is the configuration information of the marine energy storage system. Since the charging and discharging interface of the marine energy storage system can be the same charging and discharging interface or different charging and discharging interface, the different charging and discharging interface means that the charging and discharging interface of the marine energy storage system includes two independent charging interfaces and discharging interfaces. Therefore, after receiving the charging instruction for charging the marine energy storage system, the battery management system needs to determine whether there is a separate charging interface and discharging interface on the charging and discharging interface according to the charging information of the marine energy storage system. If there is a separate charging interface and discharging interface on the charging and discharging interface, the strategy of different charging and discharging interfaces can be adopted to charge the marine energy storage system; if there is no separate charging interface and discharging interface on the charging and discharging interface, the strategy of the same charging and discharging interface can be adopted to charge the marine energy storage system. Among them, different charging and discharging interfaces means that the marine energy storage system includes a separate charging interface and a discharging interface, and the same charging and discharging interface means that the charging interface and the discharging interface of the marine energy storage system are integrated into one interface.

[0111] At the same time, after determining whether there are separate charging and discharging interfaces for the charging and discharging interfaces, the charging device electrically connected to the charging and discharging interfaces may be on the ship, and at this time, the ship's energy storage system may still be supplying power to the ship. For this reason, after determining whether there are separate charging and discharging interfaces for the charging and discharging interfaces, this application also needs to determine whether the ship's energy storage system is still supplying power to the ship. If the on-off information shows that the discharge switch is closed, the discharge switch needs to be disconnected at this time, and then the charging switch corresponding to the discharge interface needs to be closed to supply power to the ship's energy storage system.

[0112] The discharge switch may be a first discharge switch of the first switch circuit and a second discharge switch of the second switch circuit in the second high-voltage box. Specifically, if the first discharge switch and the second discharge switch are in a closed state, the first discharge switch and the second discharge switch need to be opened in sequence to ensure that the ship power distribution system and the ship energy storage system are in a disconnected state.

[0113] In addition, after the ship energy storage system and the ship power distribution system are in a disconnected state, the charging switch in the second high-voltage box can be closed to charge the power supply branch. The charging switch can be a first charging switch of the first switch circuit and a second charging switch of the second switch circuit in the second high-voltage box. Specifically, after the ship energy storage system and the ship power distribution system are in a disconnected state, the second charging switch and the first charging switch can be closed in sequence.

[0114] S120: Obtain the branch voltage of each power supply branch.

[0115] Specifically, the present application can obtain the branch voltage of each power supply branch in the ship energy storage system, and then sort the power supply branches in the ship energy storage system from low to high according to the voltage, and power them on in sequence from low to high for equalization, thereby avoiding the problem of poor voltage consistency of each power supply branch during the charging process.

[0116] In some embodiments, before obtaining the branch voltage of each power supply branch, it also includes: obtaining charging information of the ship energy storage system; if the charging information is the preset first information, determining whether the communication connection between the charging and discharging interface and the charging pile is successful; if the communication connection between the charging and discharging interface and the charging pile is successful, performing fault detection on the ship energy storage system to obtain fault detection information of the ship energy storage system.

[0117] Specifically, the first information may be a charging connection confirmation signal. Since the marine energy storage system may be charged by a charging pile when it is being charged, the battery management system needs to confirm whether the charging pile is used for charging after receiving the charging instruction for charging the marine energy storage system. If the charging pile is used for charging, it is necessary to determine whether the charging connection confirmation signal sent by the charging pile at the charging and discharging interface to the battery management system of the marine energy storage system is received, that is, the first information. If the charging connection confirmation signal sent by the charging pile is received, it can be determined whether the communication connection between the charging and discharging interface and the charging pile is successful. At this time, the battery management system can run a self-test program to perform fault detection on the marine energy storage system, thereby obtaining information on whether there is a fault in the marine energy storage system.

[0118] Among them, the charging connection confirmation signal can be a CC2 signal. After the charging pile is electrically connected to the charging interface of the marine energy storage system, the battery management system of the marine energy storage system can detect the CC2 signal and be awakened. After being awakened by the CC2 signal, the battery management system can run a self-test program to perform fault detection on the marine energy storage system, thereby obtaining information on whether there is a fault in the marine energy storage system.

[0119] In some embodiments, after acquiring the charging information of the ship energy storage system, it also includes: if the charging information is the preset second information, determining whether the charging instruction is valid; if the charging instruction is valid, determining whether the ship energy storage system is successfully connected to the ship management system in communication; if the ship energy storage system is successfully connected to the ship management system in communication, performing fault detection on the ship energy storage system to obtain fault detection information.

[0120] In this embodiment, the second information is that there is no charging connection confirmation signal in the charging information. When the battery management system does not detect the charging connection signal, that is, the charging information contains the second information, it can be confirmed that the marine energy storage system is not charged by a charging pile, and it may be charged by a charger. To this end, after the battery management system fails to detect the charging connection signal, it needs to confirm whether the charging instruction sent by the ship management system to the battery management system is valid. If the charging instruction is valid, the battery management system is awakened and runs a self-test program to perform fault detection on the marine energy storage system, thereby obtaining information on whether there is a fault in the marine energy storage system; if the charging instruction is invalid, the marine energy storage system needs to be charged and protected, and a charging failure alarm is generated.

[0121] At the same time, before the battery management system runs the self-test program, if the charging and discharging interface is not electrically connected to the charging pile but to the charging device, it is necessary to further determine whether the battery management system and the ship management system are successfully connected in communication. If the communication connection is successful, the self-test program can be run to perform fault detection on the ship energy storage system.

[0122] In some embodiments, after acquiring the charging information of the marine energy storage system, it also includes: if the charging information contains preset third information, determining whether the current at the charging and discharging interface flows from the charging and discharging interface to the battery pack; if the current at the charging and discharging interface flows from the charging and discharging interface to the battery pack, performing fault detection on the marine energy storage system to obtain fault detection information.

[0123] In this embodiment, after failing to detect a charging connection signal, the battery management system can also determine whether the marine energy storage system needs to be charged by determining whether the current at the charge and discharge interface flows from the charge and discharge interface to the battery pack, that is, determining the current direction at the charge and discharge interface. If the current at the charge and discharge interface flows from the charge and discharge interface to the battery pack, it can be determined that the marine energy storage system needs to be charged, and then the battery management system is awakened and runs a self-test program to perform fault detection on the marine energy storage system, thereby obtaining information on whether there is a fault in the marine energy storage system.

[0124] At the same time, the present application can also determine whether the current at the charge and discharge interface flows from the charge and discharge interface to the battery pack after the charging instruction is invalid; if the current at the charge and discharge interface flows from the charge and discharge interface to the battery pack, it can be determined that the marine energy storage system needs to be charged, and then the battery management system is awakened and runs a self-test program to perform fault detection on the marine energy storage system, thereby obtaining information on whether there is a fault in the marine energy storage system.

[0125] In some embodiments, before performing fault detection on the marine energy storage system and obtaining fault detection information of the marine energy storage system, it also includes: obtaining the current temperature of the battery pack.

[0126] Specifically, after the battery management system determines that the marine energy storage system needs to be charged, the battery temperature in the marine energy storage system may be low due to the water environment in which the ship is located. If the self-test program is directly run to detect the fault of the marine energy storage system, a fault may be displayed due to the low battery temperature. To this end, after the battery management system determines that the marine energy storage system needs to be charged, it needs to first obtain the current temperature of the battery pack in the marine energy storage system and determine whether the current temperature of the battery pack meets the charging requirements, that is, the current temperature of the battery pack is not less than the first temperature and not greater than the second temperature. At this time, the self-test program can be run to detect the fault of the marine energy storage system; if the current temperature of the battery pack does not meet the charging requirements, that is, the current temperature of the battery pack is less than the first temperature, the battery pack needs to be heated at this time so that the temperature of the battery pack is not less than the first temperature and not greater than the second temperature; if the current temperature of the battery pack is greater than the second temperature, the battery pack needs to be cooled down at this time until the temperature of the battery pack is not less than the first temperature and not greater than the second temperature, and then the self-test program can be run to detect the fault of the marine energy storage system.

[0127] The first temperature may be a critical temperature for determining whether the marine energy storage system needs to be heated, and the second temperature may be a critical temperature for determining whether the marine energy storage system needs to be cooled. The first temperature and the second temperature may be determined based on the battery pack itself, and this application does not make any specific limitations.

[0128] In some embodiments, after obtaining the current temperature of the battery pack, it also includes: if the current temperature is less than the first temperature, generating a heating instruction to heat the battery pack; after a preset first time, detecting the temperature of the battery pack again to determine whether there is a heating fault in the marine energy storage system.

[0129] In this embodiment, when the current temperature of the battery pack in the marine energy storage system is less than the first temperature, it can be determined that the temperature of the battery pack is too low. At this time, the battery management system generates a heating instruction to heat the battery pack. The device for heating the battery pack in the marine energy storage system, such as closing the heating relay to heat the battery pack, detects the temperature of the battery pack after a preset first time. If the temperature of the battery pack is between the first temperature and the second temperature, the heating relay can be disconnected, and the self-test program can be run to perform fault detection on the marine energy storage system; if the temperature of the battery pack still does not reach the first temperature, it can be determined that a heating fault has occurred in the marine energy storage system. At this time, the heating relay needs to be disconnected, and the marine energy storage system needs to be charged and protected, and an alarm message of charging failure is generated.

[0130] In addition, before the battery management system runs the self-test program, if the charging and discharging interface of the marine energy storage system is not electrically connected to the charging pile but to the charging device, it is necessary to further determine whether the communication connection between the battery management system and the ship management system is successful. If the communication connection is successful, the self-test program can be run to perform fault detection on the marine energy storage system.

[0131] S130, determining a power-on strategy for the power supply branch according to the branch voltage, and closing a charging switch in the second high-voltage box according to the power-on strategy to power on the power supply branch.

[0132] In this embodiment, the power-on strategy is the rule information for powering on each power supply branch of the marine energy storage system before charging the marine energy storage system. For example, when there are multiple parallel power supply branches in the marine energy storage system, in order to ensure the consistency of the charging voltage of each power supply branch, the power supply branch with low voltage can be powered on first, and after the power supply branch with low voltage is powered on, the other power supply branches can be powered on in sequence; when there are two power supply branches in the energy storage system, the power supply branch with low voltage can be powered on first, and after the power supply branch with low voltage is powered on, the other power supply branch can be powered on.

[0133] In some embodiments, a power-on strategy for a power supply branch is determined according to the branch voltage, and a charging switch in a second high-voltage box is closed according to the power-on strategy to power on the power supply branch, including: determining a first power supply branch with a first branch voltage and a second power supply branch with a second branch voltage from a marine energy storage system according to the branch voltage; wherein the first branch voltage is less than or equal to the second branch voltage; closing the charging switch of the second high-voltage box in the first power supply branch to power on the first power supply branch; after powering on the first power supply branch is completed, obtaining the bus voltage of the marine energy storage system; generating a voltage difference between the second power supply branch and the bus of the marine energy storage system according to the second branch voltage and the bus voltage; closing the charging switch of the second high-voltage box in the second power supply branch with a voltage of the second branch according to the voltage difference to power on the second power supply branch.

[0134] In this embodiment, after obtaining the branch voltage of each power supply branch in the marine energy storage system, at least the first power supply branch of the first branch voltage and the second power supply branch of the second branch voltage can be determined from the branch voltage, and then the magnitude of the first branch voltage and the second branch voltage can be determined. If the first branch voltage is less than the second branch voltage, the first power supply branch can be closed to power on first, and after the first branch voltage is powered on, the second power supply branch can be powered on.

[0135] At the same time, after the first power supply branch is powered on, there is voltage on the busbar of the marine energy storage system. At this time, if the charging switch of the second high-voltage box in the second power supply branch is directly closed, it may cause the voltage difference between the power supply branches to be too large. For this reason, after the first power supply branch is powered on, the present application also needs to close the charging switch of the second high-voltage box in the second power supply branch according to the voltage difference between the second power supply branch and the busbar of the marine energy storage system to power on the second power supply branch.

[0136] In some embodiments, the charging switch in the second high-voltage box includes a first charging switch and a second charging switch, and the second high-voltage box is also provided with a balancing switch, which is connected in parallel with the first charging switch; wherein, closing the charging switch of the second high-voltage box in the first power supply branch includes: closing the second charging switch and the balancing switch of the second high-voltage box in the first power supply branch in sequence; closing the first charging switch after a preset second time, and disconnecting the balancing switch after a preset third time.

[0137] In this embodiment, the first charging switch and the second charging switch can be the main positive relay and the main negative relay in the second high-voltage box, respectively. At the same time, in order to avoid excessive voltage difference during the power-on process of the first power supply branch, the second high-voltage box is also provided with a balancing switch in parallel with the main positive relay. When it is necessary to close the charging switch of the second high-voltage box in the first power supply branch, the main negative relay, that is, the second charging switch, can be closed first, and then the balancing switch can be closed. After the preset second time, the main positive relay, that is, the first charging switch, is closed, and the balancing switch is disconnected after the preset third time, so that the power-on of the first power supply branch can be completed. Among them, the second time and the third time can be selected according to the actual application, and this application does not make specific restrictions.

[0138] In some embodiments, closing the charging switch of the second high-voltage box in the second power supply branch according to the voltage difference includes: if the voltage difference is less than a preset first voltage, closing the second charging switch and the first charging switch of the second high-voltage box in the second power supply branch in sequence; if the voltage difference is greater than or equal to the first voltage, and less than or equal to the preset second voltage, closing the second charging switch and the balancing switch of the second high-voltage box in the second power supply branch in sequence; after a preset fourth time, closing the first charging switch, and after a preset fifth time, disconnecting the balancing switch; if the voltage difference is greater than the second voltage, generating a charging protection instruction for the marine energy storage system.

[0139] Specifically, in order to avoid the voltage difference between the branch voltage and the busbar being too large during the power-on process of the high-voltage power supply branch, the present application can perform balancing through the balancing circuit of the second high-voltage box in the second power supply branch after determining the voltage difference between the second power supply branch and the busbar of the ship energy storage system. The balancing circuit includes a balancing switch and a balancing resistor connected in series.

[0140] In this embodiment, if the voltage difference is less than the first voltage, such as 5V, the second charging switch and the first charging switch of the second high-voltage box in the second power supply branch are closed in sequence; if the voltage difference is greater than or equal to the first voltage and less than or equal to the second voltage, such as 20V, the second charging switch and the equalizing switch of the second high-voltage box in the second power supply branch are closed in sequence; after the preset fourth time, the first charging switch is closed, and after the preset fifth time, the equalizing switch is disconnected; if the voltage difference is greater than the second voltage, a charging protection instruction of the marine energy storage system is generated to charge and protect the marine energy storage system. Among them, the fourth time and the fifth time can be selected according to the actual application, and this application does not make specific limitations.

[0141] In addition, there may be a situation where, after the fourth time, the voltage difference is still between the first voltage and the second voltage, and at this time, there may be a fault in the marine energy storage system, so it is necessary to power off all power supply branches of the marine energy storage system for charging protection. The fourth time may be 5 hours.

[0142] S140: If all power supply branches are powered on, close the charging switch in the first high-voltage box to charge the battery pack in each power supply branch through the first high-voltage box.

[0143] Specifically, if the shipboard energy storage system is a three-level energy storage system, there is a first high-voltage box in the shipboard energy storage system. When all power supply branches in the shipboard energy storage system are powered on, the charging switch of the first high-voltage box in the shipboard energy storage system can be closed to make the shipboard energy storage system enter the charging stage; if the shipboard energy storage system is a two-level energy storage system, when all power supply branches in the shipboard energy storage system are powered on, there is no first high-voltage box in the shipboard energy storage system. When all power supply branches in the shipboard energy storage system are powered on, the shipboard energy storage system directly enters the charging stage.

[0144] In some embodiments, the charging method of the ship energy storage system also includes: if the ship energy storage system in the charging state is abnormal, obtaining abnormal information of the ship energy storage system; if the abnormal information does not trigger the ship energy storage system to power off, determining whether to trigger the reduction of the charging current of the ship energy storage system; if the reduction of the charging current of the ship energy storage system is triggered, using a preset first current to charge the ship energy storage system.

[0145] Specifically, when the marine energy storage system is in the formal charging stage, that is, the stage when the first charging switch and the second charging switch in the second high-voltage box are both in the closed state, the battery management system can monitor the key parameters of the marine energy storage system, such as voltage, current, temperature, SOC, SOH, internal resistance, etc. When a key parameter of the marine energy storage system is detected to be abnormal, the abnormal information of the marine energy storage system can be obtained, and the abnormal information can be used to determine whether it is triggered to stop charging the marine energy storage system. If it is not triggered to stop charging the marine energy storage system, for example, if a power supply branch of the marine energy storage system is abnormal, the main circuit of the power supply branch where the battery pack is located can be disconnected, and the charging current of the marine energy storage system can be adjusted, that is, other power supply branches that have not abnormalities continue to be charged. Among them, when adjusting the charging current of the marine energy storage system, the first current can be determined according to the number of power supply branches in the energy storage system and the number of power supply branches with abnormalities, and the marine energy storage system can be charged according to the first current.

[0146] In addition, during the charging process of the marine energy storage system, the battery pack may have a low temperature due to the low water temperature in the area where the ship is located, causing the marine energy storage system to malfunction. At this time, there is no need to disconnect the main circuit of the power supply branch where the battery pack is located, and it is sufficient to reduce the charging current of the marine energy storage system.

[0147] In some embodiments, the charging method of the marine energy storage system also includes: when the marine energy storage system is in a charging state, obtaining the single cell voltage of the battery cell in the battery pack; if the single cell voltage is greater than or equal to a preset third voltage, adjusting the charging current of the marine energy storage system to a preset second current; after a preset sixth time, adjusting the charging current of the marine energy storage system to a preset third current; wherein the third current is less than the second current; after a preset seventh time, adjusting the charging current of the marine energy storage system to a preset fourth current; wherein the fourth current is less than the third current.

[0148] Specifically, in order to avoid excessive voltage difference between the terminal voltages of each power supply branch after the marine energy storage system is charged, the charging current can be reduced at least once at the charging terminal of the marine energy storage system. The charging terminal can be understood as the SOH of the marine energy storage system reaching 80% or above, and the charging terminal can also be understood as the single cell voltage of the battery cell in the marine energy storage system being not less than the preset third voltage, such as 3.48V. It should be noted that the specific value of the charging terminal can be selected according to the actual application, and this application does not make specific limitations here.

[0149] In this embodiment, if the single cell voltage is greater than or equal to the preset third voltage, the charging current of the battery pack is reduced to the second current, and after the sixth time, the charging current of the marine energy storage system is reduced from the second current to the third current, and then after the seventh time, the charging current of the marine energy storage system is reduced from the third current to the fourth current, thereby avoiding excessive voltage differences between the terminal voltages of each power supply branch.

[0150] In some embodiments, after adjusting the charging current of the marine energy storage system to a preset fourth current, it also includes: if the single cell voltage is greater than or equal to the preset fourth voltage, generating a stop charging instruction for the marine energy storage system; wherein the fourth voltage is greater than the third voltage; after a preset eighth time, obtaining the loop current of the marine energy storage system; if the loop current is less than or equal to the preset fifth current, powering off the marine energy storage system; if the loop current is greater than the fifth current, generating charging fault information of the marine energy storage system.

[0151] Specifically, after the charging current of the marine energy storage system is reduced multiple times, when the single cell voltage is greater than or equal to the preset fourth voltage, such as 3.5V, the corresponding battery pack can be determined to have completed charging, and its SOC is calibrated to 100%, and a stop charging instruction for the marine energy storage system is generated. After that, the loop current of the marine energy storage system is obtained after the preset eighth time, and it is determined whether the loop current is less than or equal to the preset fifth current, such as 5A. If the loop current is less than or equal to the fifth current, the charging switch in the first high-voltage box, such as an isolating switch, can be disconnected first, and then the charging switch in the second high-voltage box can be disconnected; if the loop current is greater than the fifth current, it can be determined that the power supply branch has a fault, and the marine energy storage system needs to be charged and protected at this time, and charging fault information of the energy storage system is generated. Among them, the eighth time can be 5s.

[0152] In addition, at any time during the charging of the marine energy storage system, if the ship management system sends a stop charging instruction to the battery management system, the battery management system can control the marine energy storage system to stop charging.

[0153] The present application provides a charging method for a marine energy storage system. After receiving a charging instruction to charge the marine energy storage system, the method determines a power-on strategy for the power supply branch by obtaining the branch voltage of each power supply branch, so as to ensure the voltage consistency of each power supply branch during the charging stage, thereby avoiding the problem of poor voltage consistency between the power supply branches after the marine energy storage system is charged, and greatly improving the reliability and safety of the marine energy storage system.

[0154] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for charging a marine energy storage system, characterized in that: The marine energy storage system comprises a plurality of power supply branches and a first high-voltage box, the plurality of power supply branches are connected in parallel, each of the power supply branches comprises at least one battery pack and a second high-voltage box, the first high-voltage box is provided with a charging and discharging interface, and the first high-voltage box is electrically connected to the second high-voltage box; the charging method comprises: receiving a charging instruction for charging the marine energy storage system; Obtaining the branch voltage of each power supply branch; Determining a power-on strategy for the power supply branch according to the branch voltage, and closing a charging switch in the second high-voltage box according to the power-on strategy to power on the power supply branch; If all the power supply branches are powered on, the charging switch in the first high-voltage box is closed to charge the battery pack in each of the power supply branches through the first high-voltage box.

2. The method for charging a marine energy storage system according to claim 1, characterized in that: Before obtaining the branch voltage of each power supply branch, the method further includes: Obtaining charging information of the marine energy storage system; If the charging information is the preset first information, determining whether the communication connection between the charging and discharging interface and the charging pile is successful; If the communication connection between the charging and discharging interface and the charging pile is successful, a fault detection is performed on the marine energy storage system to obtain fault detection information of the marine energy storage system.

3. The method for charging a marine energy storage system according to claim 2, characterized in that: After acquiring the charging information of the marine energy storage system, the method further includes: If the charging information is the preset second information, determining whether the charging instruction is valid; If the charging instruction is valid, determining whether the marine energy storage system is successfully connected to the ship management system; If the marine energy storage system is successfully connected to the ship management system for communication, a fault detection is performed on the marine energy storage system to obtain the fault detection information.

4. The method for charging a marine energy storage system according to claim 2, characterized in that: After acquiring the charging information of the marine energy storage system, the method further includes: If the charging information is the preset third information, determining whether the current at the charging and discharging interface flows from the charging and discharging interface to the battery pack; If the current flows from the charging and discharging interface to the battery pack, a fault detection is performed on the marine energy storage system to obtain the fault detection information.

5. The method for charging a marine energy storage system according to any one of claims 2 to 4, characterized in that: Before performing fault detection on the marine energy storage system, the method further includes: Obtaining the current temperature of the battery pack; If the current temperature is lower than a preset first temperature, generating a heating instruction to heat the battery pack; After a preset first time, the temperature of the battery pack is detected again to determine whether there is a heating fault in the marine energy storage system.

6. The method for charging a marine energy storage system according to any one of claims 1 to 4, characterized in that: The step of determining a power-on strategy for the power supply branch according to the branch voltage, and closing a charging switch in the second high-voltage box according to the power-on strategy to power on the power supply branch, comprises: According to the branch voltages, determining a first power supply branch with a first branch voltage and a second power supply branch with a second branch voltage from the marine energy storage system; wherein the first branch voltage is less than or equal to the second branch voltage; Closing the charging switch of the second high-voltage box in the first power supply branch to power on the first power supply branch; After the first power supply branch is powered on, obtaining the bus voltage of the marine energy storage system; generating a voltage difference between the second power supply branch and the busbar of the marine energy storage system according to the second branch voltage and the busbar voltage; A charging switch of a second high-voltage box in the second power supply branch is closed according to the voltage difference to power on the second power supply branch.

7. The method for charging a marine energy storage system according to claim 6, characterized in that: The charging switch in the second high-voltage box includes a first charging switch and a second charging switch, and the second high-voltage box is further provided with a balancing switch, and the balancing switch is connected in parallel with the first charging switch; Wherein, closing the charging switch of the second high-voltage box in the first power supply branch includes: Sequentially closing the second charging switch and the balancing switch; After a preset second time, the first charging switch is closed, and after a preset third time, the balancing switch is opened.

8. The method for charging a marine energy storage system according to claim 6, characterized in that: The charging switch in the second high-voltage box includes a first charging switch and a second charging switch, and the second high-voltage box is further provided with a balancing switch, and the balancing switch is connected in parallel with the first charging switch; Wherein, closing the charging switch of the second high-voltage box in the second power supply branch according to the voltage difference includes: If the voltage difference is less than a preset first voltage, closing the second charging switch and the first charging switch in sequence; If the voltage difference is greater than or equal to the first voltage and less than or equal to a preset second voltage, the second charging switch and the balancing switch are closed in sequence; After a preset fourth time, closing the first charging switch, and after a preset fifth time, opening the balancing switch; If the voltage difference is greater than the second voltage, a charging protection instruction for the marine energy storage system is generated.

9. The method for charging a marine energy storage system according to any one of claims 1 to 4, characterized in that: The method further comprises: If the marine energy storage system in a charging state is abnormal, obtaining abnormal information of the marine energy storage system; If the abnormal information does not trigger the power-off of the marine energy storage system, determining whether to trigger the reduction of the charging current of the marine energy storage system; If the charging current of the marine energy storage system is triggered to be reduced, the marine energy storage system is charged with a preset first current.

10. The method for charging a marine energy storage system according to any one of claims 1 to 4, characterized in that: The method further comprises: When the marine energy storage system is in a charging state, obtaining the single cell voltage of the battery cell in the battery pack; If the cell voltage is greater than or equal to a preset third voltage, adjusting the charging current of the marine energy storage system to a preset second current; After a preset sixth time, adjusting the charging current of the marine energy storage system to a preset third current; wherein the third current is less than or equal to the second current; After a preset seventh time, the charging current of the marine energy storage system is adjusted to a preset fourth current; wherein the fourth current is less than or equal to the third current.

11. The method for charging a marine energy storage system according to claim 10, characterized in that: After adjusting the charging current of the marine energy storage system to a preset fourth current, the method further includes: If the single cell voltage is greater than or equal to a preset fourth voltage, a stop charging instruction for the marine energy storage system is generated; wherein the fourth voltage is greater than the third voltage; After a preset eighth time, obtaining a loop current of the marine energy storage system; If the loop current is less than or equal to a preset fifth current, powering off the marine energy storage system; If the loop current is greater than the fifth current, charging fault information of the marine energy storage system is generated.

12. A marine energy storage system, characterized in that: It includes a plurality of power supply branches and a first high-voltage box, each of the power supply branches includes: at least one battery pack; A second high-voltage box, one end of which is electrically connected to the battery pack; Wherein, the first high-voltage box is provided with a charging and discharging interface, one end of the charging and discharging interface is electrically connected to the other end of the second high-voltage box, and the other end of the charging and discharging interface is electrically connected to the ship power distribution system and / or the charging and discharging device.

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