Control method and control device of energy storage sub-module, and energy storage system

Abstract

The invention discloses a control method and a control device of an energy storage sub-module and an energy storage system, the energy storage sub-module comprises a power unit and a battery unit, a first bridge arm in the power unit is connected in parallel with at least one bypass switch, and whether the energy storage sub-module has a fault is detected; the energy storage sub-module is connected with the bypass switch, a sub-module fault detection signal is generated under the condition that the energy storage sub-module breaks down, the bypass switch and the first bridge arm are controlled to be connected according to the sub-module fault detection signal, so that the energy storage sub-module is bypassed, the first bridge arm and the bypass switch are connected in parallel, and at least two bypass paths are provided. The quick conduction characteristic of the first bridge arm is utilized to perform quick bypass on the energy storage sub-module, and the stability of the bypass switch is utilized to provide a stable and reliable bypass path for the energy storage sub-module, so that the potential safety hazards such as battery overcharge caused by the fact that the energy storage sub-module cannot be bypassed in time are avoided.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a control method, a control device, and an energy storage system for an energy storage submodule. Background Art

[0002] With the current application and development of power electronics and battery technologies in power systems, energy storage systems are widely used in the construction of new power systems due to their advantages, such as peak and frequency regulation, and facilitating the integration of renewable energy. However, the timeliness and unpredictability of clean energy affect the stability of the power grid. New energy storage systems using batteries as the energy storage medium can achieve peak and frequency regulation, and their response speed can provide rapid inertia support for power systems. Therefore, they are a key direction for future power system development.

[0003] However, when a fault is detected in an energy storage submodule of the energy storage system, the faulty energy storage submodule in the energy storage system needs to be bypassed. In current energy storage systems, reliable bypass cannot be achieved while protecting the battery. Summary of the Invention

[0004] In view of the above problems, the present application provides a control method, a control device, and an energy storage system for an energy storage submodule, aiming to provide a reliable control method when a failure occurs in the current energy storage submodule and to solve the problem of bypass refusal in the energy storage system.

[0005] In a first aspect, an embodiment of the present application provides a control method for an energy storage submodule, wherein the energy storage submodule includes a power unit and a battery unit, and a first bridge arm in the power unit is connected in parallel with at least one bypass switch; the control method includes:

[0006] Detecting whether the energy storage submodule fails, and generating a submodule failure detection signal when the energy storage submodule fails;

[0007] The bypass switch and the first bridge arm are controlled to be turned on according to the submodule fault detection signal, so as to bypass the energy storage submodule.

[0008] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel to the first bridge arm in the power unit, so that the bypass switch is connected in parallel to the output side of the power unit. After a fault in the energy storage submodule is detected, the corresponding bypass switch and the power unit can be controlled to perform corresponding actions to bypass the energy storage submodule. The fast conduction characteristics of the first bridge arm are utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch is utilized to provide a stable and reliable bypass path for the energy storage submodule, thereby improving the stability of the bypass solution of the energy storage submodule and avoiding safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0009] In some embodiments, controlling the conduction of the bypass switch and the first bridge arm according to the submodule fault detection signal includes: generating a bypass switch closing control signal according to the submodule fault detection signal to control the conduction of the bypass switch; generating a bridge arm conduction control signal according to the submodule fault detection signal to control the conduction of the first bridge arm.

[0010] In the technical solution of the embodiment of the present application, the first bridge arm in each power unit is connected in parallel with at least one bypass switch, and a bypass switch closing control signal and a bridge arm conduction control signal are generated according to the sub-module fault detection signal, so that the first bridge arm and the bypass switch are turned on at the same time, providing multiple bypass paths for the battery cell, and utilizing the fast conduction characteristics of the first bridge arm to quickly bypass the energy storage sub-module, and utilizing the stability of the bypass switch to provide a stable and reliable bypass path for the energy storage sub-module, and when the first bridge arm and the bypass switch refuse to operate at the same time, the battery cell can be bypassed by causing the first bridge arm to overvoltage and break down, thereby improving the stability of the bypass scheme of the energy storage sub-module.

[0011] In some embodiments, the control method further includes: detecting a state of the bypass switch, and controlling a battery switch unit between the battery unit and the power unit to disconnect when the bypass switch refuses to operate.

[0012] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel to the first bridge arm within each power unit, and the state of the bypass switch is detected. If the bypass switch receives a bypass switch closing control signal but fails to execute the closing action, it is determined that the bypass switch has refused to operate. If the bypass switch and the first bridge arm refuse to operate, the energy storage submodule can be bypassed by isolating the battery cell and continuously increasing the capacitor voltage in the charging state to cause overvoltage breakdown in the first bridge arm. This provides multiple bypass measures for the energy storage submodule, improves the stability of the bypass solution of the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0013] In some embodiments, the control method further includes: detecting a state of the first bridge arm, and controlling a battery switch unit between the battery unit and the power unit to disconnect when the first bridge arm refuses to operate.

[0014] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel to the first bridge arm in each power unit, and the state of the first bridge arm is detected. If the first bridge arm receives a bridge arm conduction control signal but fails to perform a conduction action, it is determined that the first bridge arm has refused to operate. If the bypass switch and the first bridge arm refuse to operate, the energy storage submodule can be bypassed by isolating the battery cell and continuously increasing the capacitor voltage in the charging state to cause overvoltage breakdown in the first bridge arm. This provides multiple bypass measures for the energy storage submodule, improves the stability of the bypass solution of the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0015] In some embodiments, the control method further includes: detecting the status of the first bridge arm and the bypass switch, and controlling the battery switch unit between the battery unit and the power unit to disconnect when the first bridge arm and the bypass switch refuse to operate.

[0016] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel with the first bridge arm in the power unit so that the bypass switch is connected in parallel with the output side of the power unit. After detecting that the first bridge arm and the bypass switch refuse to operate, the capacitor in the power unit can be charged while isolating the battery unit, thereby bypassing the energy storage submodule by causing the first bridge arm to overvoltage and break down due to a continuous increase in the capacitor voltage in the charging state, thereby improving the stability of the bypass scheme of the energy storage submodule.

[0017] In some embodiments, the control method further includes: detecting the state of the bypass switch and generating a bypass switch closing detection signal when the bypass switch is successfully closed; and controlling the first bridge arm to be disconnected according to the bypass switch closing detection signal.

[0018] In the technical solution of the embodiments of the present application, if the bypass switch receives a bypass switch closing control signal and successfully performs a conduction operation according to the bypass switch closing control signal, it indicates that the bypass switch has been successfully closed. If the bypass switch is successfully closed, the battery unit has been bypassed, and the first bridge arm can be controlled to be disconnected, thereby achieving the purpose of saving energy consumption.

[0019] In some embodiments, the control method further includes: detecting a state of the bypass switch, and controlling the first bridge arm to remain conductive when the bypass switch refuses to operate.

[0020] In the technical solution of the embodiments of the present application, if the bypass switch receives a bypass switch closing control signal and fails to perform a conduction operation according to the bypass switch closing control signal, then the bypass switch remains open despite receiving the bypass switch closing control signal, indicating that the bypass switch has failed to close and the bypass switch has refused to operate. In the event of a bypass switch refusal to operate, it is necessary to control the first bridge arm to remain conductive to provide a bypass path for the energy storage submodule, thereby avoiding safety hazards such as battery overcharging caused by the energy storage submodule's inability to bypass in a timely manner.

[0021] In some embodiments, before the battery switch unit is disconnected, the method further includes: controlling the branch current of the energy storage submodule to remain within a preset safety current range.

[0022] In the technical solution of the embodiment of the present application, since the current flowing through the energy storage sub-module is relatively large, by controlling the branch current of the energy storage sub-module to remain within a preset safe current range and then controlling the first bridge arm to disconnect, it is possible to avoid the current flowing through the first bridge arm being too large, which may cause a safety hazard in the disconnection operation.

[0023] In some embodiments, after the battery switch unit is disconnected, the method further includes: controlling the branch current of the energy storage submodule to recover to the operating current range before the first bridge arm is disconnected.

[0024] In the technical solution of the embodiment of the present application, after the battery switch unit is disconnected, the power unit and the battery unit have been isolated, and the output side of the power unit has been bypassed. The branch current of the energy storage submodule can be restored to the operating current range before the first bridge arm is disconnected, so that the energy storage system is restored to a normal working state, ensuring the normal operation of the energy storage system.

[0025] A second aspect of the embodiments of the present application further provides a control device for an energy storage submodule, wherein the energy storage submodule includes a power unit and a battery unit, wherein a first bridge arm in the power unit is connected in parallel with at least one bypass switch; the control device includes:

[0026] A main control module is used to detect whether the energy storage submodule has a fault and generate a submodule fault detection signal when the energy storage submodule has a fault;

[0027] The switch driving module is used to control the bypass switch and the first bridge arm to be turned on according to the submodule fault detection signal, so as to bypass the energy storage submodule.

[0028] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel to the first bridge arm in the power unit, so that the bypass switch is connected in parallel to the output side of the power unit. The main control module detects the status of the energy storage submodule. After detecting a fault in the energy storage submodule, the corresponding bypass switch and the power unit can be controlled to perform corresponding actions to bypass the energy storage submodule, thereby providing multiple bypass measures for the energy storage submodule, improving the stability of the bypass solution of the energy storage submodule, and avoiding safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass the energy storage submodule in time.

[0029] In some embodiments, the switch driving module further includes: a battery switch driving unit, configured to control the battery switch unit between the battery unit and the power unit to be disconnected according to the submodule fault detection signal.

[0030] In the technical solution of the embodiment of the present application, the power unit is connected to the battery unit via the battery switch unit, and the bypass switch is connected in parallel with the output side of the power unit, so that after the main control module detects that the energy storage submodule has failed, it can control the corresponding bypass switch and power unit to perform corresponding actions to bypass the energy storage submodule, and control the battery switch unit between the battery unit and the power unit to disconnect. If the bypass switch and the first bridge arm refuse to operate and isolate the battery unit from the power unit, the energy storage submodule can be bypassed by continuously increasing the capacitor voltage in the charging state to cause one of the bridge arms to overvoltage and break down, thereby ensuring that the energy storage submodule has multiple bypass measures and realizing electrical isolation between the battery unit and the power unit in the event of a failure in the energy storage submodule, thereby protecting the battery unit.

[0031] In some embodiments, the switch driving module includes:

[0032] A bypass switch driving unit, configured to generate a bypass switch closing control signal according to the submodule fault detection signal, so as to control the bypass switch to be turned on;

[0033] The bridge arm driving unit is used to generate a bridge arm conduction control signal according to the submodule fault detection signal to control the first bridge arm to be conducted.

[0034] In the technical solution of the embodiment of the present application, the first bridge arm in each power unit is connected in parallel with at least one bypass switch, the bypass switch driving unit generates a bypass switch closing control signal according to the sub-module fault detection signal, and the bridge arm driving unit generates a bridge arm conduction control signal according to the sub-module fault detection signal, so that the first bridge arm and the bypass switch are turned on at the same time, providing multiple bypass paths for the battery cell, and when the first bridge arm and the bypass switch fail to operate at the same time, the battery cell is bypassed by causing the first bridge arm to overvoltage and break down, thereby improving the stability of the bypass scheme of the energy storage sub-module.

[0035] In some embodiments, the main control module includes: a bypass switch detection unit, which is used to detect the state of the bypass switch and generate a bypass switch refusal detection signal when the bypass switch refuses to operate; the bridge arm driving unit is also used to generate the bridge arm conduction control signal according to the bypass switch refusal detection signal to control the first bridge arm to remain conductive.

[0036] In the technical solution of the embodiments of the present application, the bypass switch detection unit is used to detect the state of the bypass switch. If the bypass switch receives a bypass switch closing control signal and the bypass switch fails to perform a conduction operation according to the bypass switch closing control signal, the bypass switch remains open despite receiving the bypass switch closing control signal. The bypass switch detection unit detects that the bypass switch has failed to close and the bypass switch has refused to operate. In the event of a bypass switch refusal to operate, the bridge arm drive unit controls the first bridge arm to remain conductive, providing a bypass path for the energy storage submodule, thereby preventing safety hazards such as battery overcharging caused by the energy storage submodule's inability to bypass in a timely manner.

[0037] In some embodiments, the bypass switch detection unit is further used to generate a bypass switch closing detection signal when the bypass switch is successfully closed; the bridge arm driving unit is further used to control the first bridge arm to be disconnected according to the bypass switch closing detection signal.

[0038] In the technical solution of the embodiments of the present application, the bypass switch detection unit detects the state of the bypass switch. If the bypass switch receives a bypass switch closing control signal and the bypass switch successfully performs a conduction operation according to the bypass switch closing control signal, it indicates that the bypass switch has been successfully closed. If the bypass switch is successfully closed, the battery unit has been bypassed, and the first bridge arm can be controlled to be disconnected, thereby achieving the purpose of energy consumption.

[0039] In some embodiments, the main control module also includes: a bridge arm detection unit, which is used to detect the state of the first bridge arm and generate a bridge arm refusal detection signal when the first bridge arm refuses to move; the battery switch drive unit is also used to control the battery switch unit between the battery unit and the power unit to disconnect according to the bridge arm refusal detection signal.

[0040] In the technical solution of the embodiment of the present application, the first bridge arm in each power unit is connected in parallel with at least one bypass switch, and the bridge arm detection unit detects the state of the first bridge arm. If the first bridge arm receives the bridge arm conduction control signal but fails to perform the conduction action, it is determined that the first bridge arm has refused to operate. If the bypass switch and the first bridge arm refuse to operate, the battery switch drive unit can control the battery switch unit between the battery unit and the power unit to disconnect according to the bridge arm refusal detection signal. In the case of isolating the battery unit, the capacitor voltage in the charging state continues to rise, causing the first bridge arm to overvoltage and break down to achieve bypass of the energy storage submodule, thereby providing multiple bypass measures for the energy storage submodule, improving the stability of the bypass solution of the energy storage submodule, and avoiding safety hazards such as battery overcharging caused by the energy storage submodule's failure to bypass in time.

[0041] In some embodiments, the control device further includes: a current regulating unit, configured to control the branch current of the energy storage submodule to remain within a preset safety current range before the first bridge arm is disconnected according to the bridge arm conduction control signal.

[0042] In the technical solution of the embodiment of the present application, since the current flowing through the energy storage sub-module is relatively large, the branch current of the energy storage sub-module is controlled by the current regulation unit to remain within a preset safe current range, and then the first bridge arm is controlled to be disconnected. This can avoid the problem of excessive current flowing through the first bridge arm, which may cause safety hazards in the disconnection operation.

[0043] In some embodiments, the current regulating unit is further configured to control the branch current of the energy storage submodule to recover to the operating current range before the first bridge arm is disconnected according to the bridge arm conduction control signal after the first bridge arm is disconnected.

[0044] In the technical solution of the embodiment of the present application, after the battery switch unit is disconnected, the power unit and the battery unit have been isolated, and the output side of the power unit has been bypassed. The branch current of the energy storage submodule is restored to the operating current range before the first bridge arm is disconnected through the current regulation unit, so that the energy storage system is restored to a normal working state, ensuring the normal operation of the energy storage system.

[0045] A third aspect of the embodiments of the present application further provides an energy storage system, the energy storage system comprising: a plurality of bypass switches, a plurality of energy storage submodules, and a main control module; the plurality of energy storage submodules are connected in series, and each energy storage submodule is connected in parallel with at least one bypass switch; the energy storage submodule comprises a power unit, a battery unit, and a battery switch unit, the power unit is connected to the battery unit via the battery switch unit, and the bypass switch is connected in parallel with one of the bridge arms of the power unit;

[0046] The main control module is used to execute the control method described in any of the above embodiments.

[0047] In the technical solution of the embodiment of the present application, at least one bypass switch is connected in parallel to the first bridge arm in the power unit, so that the bypass switch is connected in parallel to the output side of the power unit, and the power unit is connected to the battery unit via the battery switch unit. After a fault in the energy storage submodule is detected, the corresponding bypass switch and the power unit can be controlled to perform corresponding actions to bypass the energy storage submodule, thereby providing multiple bypass measures for the energy storage submodule, improving the stability of the bypass solution of the energy storage submodule, and avoiding safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0048] In some embodiments, the power unit includes at least a first bridge arm, a second bridge arm, and a bus capacitor. The first bridge arm and the second bridge arm are connected in series to form a bridge arm circuit. The first bridge arm is connected in parallel with the bypass switch, and the bus capacitor is connected in parallel with the bridge arm circuit.

[0049] In the technical solution of the embodiment of the present application, the first bridge arm and the second bridge arm are connected in series to form a bridge arm circuit, the bridge arm circuit is connected in parallel with the bus capacitor, the bridge arm circuit can be controlled by the main control module to charge or discharge the battery unit, and the bypass switch is connected in parallel with the first bridge arm. With such a design, two bypass paths can be set for the energy storage submodule, and after detecting that the energy storage submodule has a fault, the corresponding bypass switch and power unit can be controlled to perform corresponding actions, and the battery unit and the power unit can be isolated. If the bypass switch and the first bridge arm refuse to operate, the energy storage submodule can be bypassed by continuously increasing the capacitor voltage in the charging state to cause overvoltage breakdown of the first bridge arm while isolating the battery unit, thereby ensuring that the energy storage submodule has multiple bypass measures and realizing electrical isolation of the battery unit and the power unit in the event of a fault in the energy storage submodule.

[0050] In some embodiments, the energy storage submodule further includes: an overvoltage protection unit, which is connected in parallel with the first bridge arm and is used to bypass the first bridge arm when the voltage at both ends of the first bridge arm is overvoltage.

[0051] In the technical solution of the embodiments of this application, when the voltage across the first bridge arm reaches a certain level, the overvoltage protection unit is passively triggered to reliably short-circuit the overvoltage protection unit, preventing the first bridge arm from overvoltage breakdown. By providing the overvoltage protection unit in parallel with the first bridge arm, the first bridge arm can be short-circuited at a voltage threshold significantly lower than the breakdown voltage of the first bridge arm, thereby bypassing the energy storage submodule.

[0052] In the technical solution of the embodiment of the present application, the energy storage submodule includes a power unit and a battery unit. The first bridge arm in the power unit is connected in parallel with at least one bypass switch to detect whether the energy storage submodule has a fault and generate a submodule fault detection signal when the energy storage submodule has a fault. The bypass switch and the first bridge arm are controlled to be turned on according to the submodule fault detection signal to bypass the energy storage submodule. The energy storage submodule is quickly bypassed by utilizing the fast conduction characteristics of the first bridge arm, and the stability of the bypass switch is utilized to provide a stable and reliable bypass path for the energy storage submodule, thereby improving the stability of the bypass solution of the energy storage submodule and avoiding safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0053] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0055] Figure 1 Schematic diagram of the control method provided in this embodiment Figure 1 ;

[0056] Figure 2 Schematic diagram of the control method provided in this embodiment Figure 2 ;

[0057] Figure 3 Schematic diagram of the control method provided in this embodiment Figure 3 ;

[0058] Figure 4 Schematic diagram of the control method provided in this embodiment Figure 4 ;

[0059] Figure 5 Schematic diagram of the control method provided in this embodiment Figure 5 ;

[0060] Figure 6 Schematic diagram of the control method provided in this embodiment Figure 6 ;

[0061] Figure 7 Schematic diagram of the control method provided in this embodiment Figure 7;

[0062] Figure 8 Schematic diagram of the control method provided in this embodiment Figure 8 ;

[0063] Figure 9 Schematic diagram of the control method provided in this embodiment Figure 9 ;

[0064] Figure 10 Schematic diagram of the structure of the energy storage submodule provided in the embodiment of the present application Figure 1 ;

[0065] Figure 11 Schematic diagram of the structure of the energy storage submodule provided in the embodiment of the present application Figure 2 ;

[0066] Figure 12 A schematic diagram of the structure of the energy storage system provided in an embodiment of the present application;

[0067] Figure 13 Schematic diagram of the structure of the energy storage submodule provided in the embodiment of the present application Figure 3 ;

[0068] Figure 14 Schematic diagram of the structure of the energy storage submodule provided in the embodiment of the present application Figure 4 . DETAILED DESCRIPTION

[0069] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0071] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0072] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. References to the phrase "second connection port" at various locations in the specification do not necessarily refer to the same embodiment, nor do they constitute independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0073] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0074] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0075] As power systems continue to evolve towards sustainability and greener energy under existing policies, the proportion of clean energy sources such as wind power and photovoltaics in power grids continues to increase, placing higher demands on traditional power grids. Flexible DC transmission provides a reliable solution for large-scale, long-distance power transmission and the integration of clean energy into the grid. However, the time-sensitive and unpredictable nature of clean energy impacts grid stability. New energy storage systems using batteries as storage media can provide peak and frequency regulation, and their response speed can provide rapid inertia support for power systems, making them a key area of ​​future power system development.

[0076] Because new energy storage systems are often used in conjunction with flexible direct current transmission projects, their structure is similar to flexible direct current converter valves. The addition of high-energy-density energy storage units to flexible direct currents places higher demands on equipment reliability. Energy storage systems typically consist of a cascade of half-bridge or full-bridge submodules containing energy storage modules and power units. These systems are typically equipped with a certain number of redundant submodules, relying on internal bypass devices to effectively bypass faulty submodules, preventing the impact of a single faulty submodule on the entire energy storage system and ensuring the safety of the internal battery cells. This requires the bypass device to be able to achieve electrical isolation from the battery cells in the event of a fault, while also ensuring the reliability and long-term flow capacity of the submodule bypass.

[0077] Typically, in the event of a submodule failure, the submodule closes the bypass switch to maintain access to the entire link and isolates the faulty submodule by short-circuiting. Furthermore, the energy storage submodule also needs to isolate the power unit and battery cells within the faulty submodule to ensure battery safety. For these common submodule failures, bypass can ideally achieve the desired results. However, in the event of a bypass device failure, the bypass device becomes ineffective and cannot be closed, necessitating a redundant bypass solution to ensure long-term backup power flow capacity.

[0078] In order to solve the above technical problems, the present application provides a control method for an energy storage submodule. Figure 1 As shown, the energy storage submodule includes a power unit 210 and a battery unit 240. The first bridge arm in the power unit 210 is connected in parallel with at least one bypass switch 100. Figure 2 As shown, the control method includes step S110 and step S120.

[0079] In step S110 , it is detected whether the energy storage submodule fails, and a submodule failure detection signal is generated if the energy storage submodule fails.

[0080] In step S120 , the bypass switch 100 and the first bridge arm are controlled to be turned on according to the submodule fault detection signal, so as to bypass the energy storage submodule.

[0081] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm in the power unit 210, so that the bypass switch 100 is connected in parallel to the output side of the power unit 210. Upon detecting a fault in the energy storage submodule, the corresponding bypass switch 100 and the power unit 210 can be controlled to perform corresponding actions to bypass the energy storage submodule. The fast conduction characteristics of the first bridge arm are utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch 100 is utilized to provide a stable and reliable bypass path for the energy storage submodule. This provides multiple bypass measures for the energy storage submodule, improves the stability of the bypass solution for the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass the energy storage submodule in a timely manner.

[0082] In some embodiments, the power unit 210 may be a half-bridge circuit or a full-bridge circuit.

[0083] In some embodiments, the power unit 210 may be a bridge circuit formed by connecting a plurality of half-bridge circuits in parallel, wherein at least one bridge arm in the bridge circuit may serve as a first bridge arm.

[0084] In some embodiments, the power unit 210 may be a bridge circuit formed by connecting a plurality of half-bridge circuits in parallel, wherein at least one bridge arm in each half-bridge circuit is connected in parallel with at least one bypass switch 100 .

[0085] In some embodiments, step S120 includes: generating a bypass switch closing control signal according to the submodule fault detection signal to control the bypass switch 100 to be turned on; generating a bridge arm conduction control signal according to the submodule fault detection signal to control the first bridge arm to be turned on.

[0086] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm in each power unit 210. A bypass switch closing control signal and a bridge arm conduction control signal are generated based on the submodule fault detection signal, so that the first bridge arm and the bypass switch 100 are turned on at the same time. The fast conduction characteristic of the first bridge arm is utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch 100 is utilized to provide a stable and reliable bypass path for the energy storage submodule, thereby achieving the purpose of providing multiple bypass paths for the battery unit 240. In addition, when the first bridge arm and the bypass switch 100 fail to operate at the same time, the battery unit 240 is bypassed by causing the first bridge arm to overvoltage and break down, thereby improving the stability of the bypass scheme of the energy storage submodule.

[0087] In some embodiments, see Figure 3 As shown, the control method in this embodiment further includes step S130. In step S130, the state of the bypass switch 100 is detected, and the battery switch unit 220 between the battery unit 240 and the power unit 210 is controlled to be disconnected when the bypass switch 100 fails to operate.

[0088] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm within each power unit 210. The state of the bypass switch 100 is detected. If the bypass switch 100 receives a bypass switch closing control signal but fails to close, it is determined that the bypass switch 100 has failed to operate. In the event of a bypass switch 100 failing to operate, the probability of bypassing the energy storage submodule by relying on the first bridge arm and the bypass switch 100 to be turned on is greatly reduced. In this case, the battery switch unit 220 can be directly controlled to be turned off. If the bypass switch 100 and the first bridge arm fail to operate, the energy storage submodule can be bypassed by isolating the battery unit 240 by continuously increasing the capacitor voltage in the charging state to cause overvoltage breakdown in the first bridge arm. This provides multiple bypass measures for the energy storage submodule, improves the stability of the bypass solution of the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in a timely manner.

[0089] In some embodiments, see Figure 4As shown, the control method in this embodiment further includes step S140. In step S140, the state of the first bridge arm is detected, and the battery switch unit 220 between the battery unit 240 and the power unit 210 is controlled to be disconnected when the first bridge arm fails to operate.

[0090] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm within each power unit 210. The state of the first bridge arm is detected. If the first bridge arm receives a bridge arm conduction control signal but fails to conduct, it is determined that the first bridge arm has failed to operate. In the event of a first bridge arm failure, the probability of bypassing the energy storage submodule by relying on the first bridge arm and bypass switch 100 to conduct is greatly reduced. In this case, the battery switch unit 220 can be directly controlled to shut down. If both the bypass switch 100 and the first bridge arm within the power unit 210 fail to operate, the energy storage submodule can be bypassed by isolating the battery unit 240 and causing the first bridge arm to overvoltage and break down due to the continuous increase in the capacitor voltage in the charging state. This not only provides multiple bypass measures for the energy storage submodule, but also greatly improves the bypass speed of the energy storage submodule, improves the stability of the bypass solution of the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in a timely manner.

[0091] In some embodiments, see Figure 5 As shown, the control method in this embodiment further includes step S150. In step S150, the states of the first bridge arm and the bypass switch 100 are detected, and if the first bridge arm and the bypass switch 100 fail to operate, the battery switch unit 220 between the battery unit 240 and the power unit 210 is controlled to be disconnected.

[0092] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm in the power unit 210, so that the bypass switch 100 is connected in parallel to the output side of the power unit 210. After detecting that the first bridge arm and the bypass switch 100 have failed to operate, the capacitor in the power unit 210 can be charged while isolating the battery unit 240. In this way, the capacitor voltage continues to increase in the charging state, causing the first bridge arm to overvoltage and break down, thereby bypassing the energy storage submodule, thereby improving the stability of the bypass scheme of the energy storage submodule.

[0093] In some embodiments, see Figure 6 As shown, the control method in this embodiment further includes step S161 and step SS162.

[0094] In step S161 , the state of the bypass switch 100 is detected, and a bypass switch 100 closing detection signal is generated when the bypass switch 100 is successfully closed.

[0095] In step S162 , the first bridge arm is controlled to be disconnected according to the closing detection signal of the bypass switch 100 .

[0096] In this embodiment, upon detecting a fault in the energy storage submodule, the corresponding bypass switch 100 and power unit 210 can be controlled to perform corresponding actions to bypass the energy storage submodule. The fast conduction characteristics of the first bridge arm are utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch 100 is utilized to provide a stable and reliable bypass path for the energy storage submodule. If the bypass switch 100 receives a bypass switch closing control signal and the bypass switch 100 successfully performs a conduction operation according to the bypass switch closing control signal, it indicates that the bypass switch 100 has been successfully closed and a stable and reliable bypass path has been provided for the energy storage submodule. Therefore, if the bypass switch 100 is successfully closed, the battery unit 240 has been bypassed, and the first bridge arm can be controlled to be disconnected, thereby preventing the first bridge arm from being in a long-term conductive state and causing damage to the device, thereby achieving the purpose of saving energy consumption.

[0097] In some embodiments, see Figure 7 As shown, the control method in this embodiment further includes step S170. In step S170, the state of the bypass switch 100 is detected, and the first bridge arm is controlled to remain turned on when the bypass switch 100 refuses to operate.

[0098] In this embodiment, if the bypass switch 100 receives a bypass switch closing control signal and fails to perform a conduction operation according to the bypass switch closing control signal, then the bypass switch 100 remains open despite receiving the bypass switch closing control signal. This indicates that the bypass switch 100 has failed to close and has failed to operate. If the bypass switch 100 fails to operate, it is necessary to control the first bridge arm to remain conductive to provide a bypass path for the energy storage submodule, thereby preventing safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass the energy storage submodule in a timely manner.

[0099] In some embodiments, in step S150 , before the battery switch unit 220 is disconnected, the method further includes: controlling the branch current of the energy storage submodule to remain within a preset safety current range.

[0100] In this embodiment, since the current flowing through the energy storage submodule is relatively large, by controlling the branch current of the energy storage submodule to remain within a preset safe current range and then controlling the first bridge arm to disconnect, it is possible to avoid the current flowing through the first bridge arm being too large, which may cause a safety hazard in the disconnection operation.

[0101] In some embodiments, in step S150 , after the battery switch unit 220 is disconnected, the method further includes: controlling the branch current of the energy storage submodule to recover to the operating current range before the first bridge arm is disconnected.

[0102] In this embodiment, after the battery switch unit 220 is disconnected, the power unit 210 and the battery unit 240 have been isolated, and the output side of the power unit 210 has been bypassed. The branch current of the energy storage submodule can be restored to the operating current range before the first bridge arm is disconnected, so that the energy storage system returns to a normal working state, ensuring the normal operation of the energy storage system.

[0103] In one embodiment, combined Figure 8 As shown, in the event of a failure in the energy storage submodule 200, a bypass switch closing control signal is sent to the corresponding bypass switch 100, and a bridge arm conduction control signal is sent to the first bridge arm. At this time, the first bridge arm and bypass switch 100 can simultaneously perform a conduction operation, utilizing the fast conduction characteristics of the first bridge arm to quickly bypass the energy storage submodule, and utilizing the stability of the bypass switch 100 to provide a stable and reliable bypass path for the energy storage submodule, thereby providing multiple bypass measures for the energy storage submodule. After the first bridge arm and bypass switch 100 can simultaneously perform the conduction operation, the bypass switch 100 is detected to be closed. If the bypass switch 100 is successfully closed, it indicates that the bypass switch 100 has been successfully bypassed, and the first bridge arm can be controlled to be disconnected. Furthermore, in order to ensure the safety of the battery unit 240, the battery switch unit 220 can be controlled to disconnect after the bypass switch 100 successfully bypasses the energy storage submodule 200, that is, the battery unit 240 is isolated from the energy storage system by setting the battery switch unit 220 to be disconnected, thereby avoiding the impact of the faulty submodule on the energy storage system and improving the stability of the energy storage system.

[0104] If it is detected that the bypass switch fails to close, that is, it is determined that the bypass switch 100 has refused to operate, the first bridge arm is kept turned on and it is detected whether the first bridge arm is driven normally. If the first bridge arm cannot be driven normally, it is determined that the first bridge arm has refused to operate. At this time, the battery switch unit 220 is controlled to be disconnected. When the battery unit 240 is isolated, the bus capacitor in the power unit 210 can be continuously charged to gradually increase the voltage across its two ends, causing the first bridge arm to overvoltage and break down, thereby achieving the purpose of bypassing the energy storage submodule 200, ensuring that the energy storage submodule 200 has multiple bypass measures, and realizing electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure of the energy storage submodule 200.

[0105] If it is detected that the first bridge arm can be driven normally, the first bridge arm is kept turned on, and the first bridge arm is used to bypass the energy storage submodule 200. The battery unit 240 can also be isolated from the energy storage system by controlling the battery switch unit 220 to be disconnected, thereby avoiding the impact of the faulty submodule on the energy storage system and improving the stability of the energy storage system.

[0106] In some embodiments, combined Figure 9As shown, if the battery switch unit 220 includes an isolating switch, in the solution where the isolating switch is used as the switch, the current needs to be controlled within a safe range before the isolating switch can be disconnected. Therefore, in the solution where the isolating switch is used as the switch between the battery unit 240 and the power unit 210, the bypass strategy of this solution differs from the above-mentioned bypass strategy in that the submodule controller needs to add a step of reducing the current before disconnecting the isolating switch. That is, if the first bridge arm is abnormally disconnected, the main control module 300 controls the branch current of the energy storage submodule 200 to remain within a preset safe current range, and then controls the battery switch unit 220 to disconnect. At this time, when the battery switch unit 220 is controlled to disconnect, in the case of isolating the battery unit 240, the bus capacitor in the power unit 210 can be continuously charged to gradually increase the voltage across its two ends, causing the first bridge arm to overvoltage and break down, thereby achieving the purpose of bypassing the energy storage submodule 200. This ensures that the energy storage submodule 200 has multiple bypass measures and achieves electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure in the energy storage submodule 200.

[0107] In some specific application embodiments, the final bypass state of the energy storage submodule 200 is determined by comprehensively analyzing the results of various bypass measures, and the results of this comprehensive determination are uploaded to a host computer, which can be a valve control center. If the bypass switch 100 is closed (i.e., the bypass switch 100 is on) or the first bridge arm IGBT1 is in the on state, the energy storage submodule 200 is considered to have been successfully bypassed. Even if the energy storage submodule 200 is successfully bypassed, the battery unit 240 can be isolated from the energy storage system by controlling the battery switch unit 220 to be disconnected, thereby preventing the impact of the faulty submodule on the energy storage system and improving the stability of the energy storage system.

[0108] If the bypass switch 100 is in the open position (i.e., the bypass switch 100 is disconnected) and a drive fault occurs in the first bridge arm IGBT1, the bypass state of the energy storage submodule 200 is determined based on the switch state of the battery switch unit 220. If the battery switch unit 220 is in the closed position, it is determined that the bypass has failed. If the battery switch unit 220 is in the open position, the bypass is successful after the branch current reaches a preset voltage at both ends of the faulty submodule, triggering the overvoltage protection and short-circuiting the output end of the energy storage submodule 200.

[0109] The present application embodiment provides a control device for an energy storage submodule. Figure 10As shown, the energy storage submodule includes a power unit 210 and a battery unit 240. At least one bypass switch 100 is connected in parallel to the first bridge arm within the power unit 210. The control device includes a main control module 300 and a switch driver module 400. The main control module 300 is used to detect whether the energy storage submodule has a fault and generate a submodule fault detection signal if the energy storage submodule has a fault. The switch driver module 400 is used to control the bypass switch 100 and the first bridge arm to conduct according to the submodule fault detection signal, thereby bypassing the energy storage submodule.

[0110] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm in the power unit 210, so that the bypass switch 100 is connected in parallel to the output side of the power unit 210. The main control module 300 detects the status of the energy storage submodule. Upon detecting a fault in the energy storage submodule, the corresponding bypass switch 100 and the power unit 210 can be controlled to perform corresponding actions to bypass the energy storage submodule. The fast conduction characteristics of the first bridge arm are utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch 100 is utilized to provide a stable and reliable bypass path for the energy storage submodule. This achieves the purpose of providing multiple bypass measures for the energy storage submodule, improves the stability of the bypass solution for the energy storage submodule, and avoids safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass the energy storage submodule in a timely manner.

[0111] In some embodiments, see Figure 11 As shown, the switch driving module 400 includes a battery switch driving unit 430 , which is used to control the battery switch unit 220 between the battery unit 240 and the power unit 210 to be disconnected according to the submodule fault detection signal.

[0112] In this embodiment, the power unit 210 is connected to the battery unit 240 via the battery switch unit 220, and the bypass switch 100 is connected in parallel with the output side of the power unit 210, so that after detecting a fault in the energy storage submodule, the main control module 300 can control the corresponding bypass switch 100 and the power unit 210 to perform corresponding actions to bypass the energy storage submodule, utilize the fast conduction characteristics of the first bridge arm to quickly bypass the energy storage submodule, and utilize the stability of the bypass switch 100 to provide a stable and reliable bypass path for the energy storage submodule, thereby achieving the purpose of providing multiple bypass paths for the battery unit 240.

[0113] In some embodiments, upon detecting a failure in the energy storage submodule, the main control module 300 can control the disconnection of the battery switch unit 220 between the corresponding battery cell 240 and the power unit 210. If the bypass switch 100 and the first bridge arm fail to operate, the battery cell 240 and the power unit 210 are isolated. With the battery cell 240 isolated, the energy storage submodule can be bypassed by continuously increasing the capacitor voltage in a charged state, causing an overvoltage breakdown in one of the bridge arms. This ensures that the energy storage submodule has multiple bypass measures and, in the event of a failure in the energy storage submodule, electrically isolates the battery cell 240 from the power unit 210, protecting the battery cell 240.

[0114] In some embodiments, see Figure 11 As shown, the switch driving module 400 includes a bypass switch driving unit 410 and a bridge arm driving unit 420. The bypass switch driving unit 410 is used to generate a bypass switch closing control signal according to the submodule fault detection signal to control the bypass switch 100 to be turned on; the bridge arm driving unit 420 is used to generate a bridge arm conduction control signal according to the submodule fault detection signal to control the first bridge arm to be turned on.

[0115] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm in each power unit 210. The bypass switch driving unit 410 generates a bypass switch closing control signal based on the submodule fault detection signal, and the bridge arm driving unit 420 generates a bridge arm conduction control signal based on the submodule fault detection signal, so that the first bridge arm and the bypass switch 100 are turned on at the same time. The fast conduction characteristic of the first bridge arm is utilized to quickly bypass the energy storage submodule, and the stability of the bypass switch 100 is utilized to provide a stable and reliable bypass path for the energy storage submodule, thereby achieving the purpose of providing multiple bypass paths for the battery unit 240. In addition, when the first bridge arm and the bypass switch 100 fail to operate at the same time, the battery unit 240 is bypassed by causing the first bridge arm to overvoltage and break down, thereby improving the stability of the bypass scheme of the energy storage submodule.

[0116] In some embodiments, the main control module 300 includes a bypass switch detection unit, which is used to detect the state of the bypass switch 100 and generate a bypass switch 100 refusal detection signal when the bypass switch 100 refuses to operate; the bridge arm drive unit 420 is also used to generate a bridge arm conduction control signal based on the bypass switch 100 refusal detection signal to control the first bridge arm to remain conductive.

[0117] In this embodiment, the bypass switch detection unit is used to detect the status of the bypass switch 100. If the bypass switch 100 receives a bypass switch closing control signal and fails to perform a conduction operation according to the bypass switch closing control signal, the bypass switch 100 remains open despite receiving the bypass switch closing control signal. The bypass switch detection unit detects that the bypass switch 100 has failed to close and that the bypass switch 100 has failed to operate. If the bypass switch 100 fails to operate, the bridge arm driving unit 420 controls the first bridge arm to remain conductive, providing a bypass path for the energy storage submodule, thereby preventing safety hazards such as battery overcharging caused by the energy storage submodule's inability to bypass the energy storage submodule in a timely manner.

[0118] In some embodiments, the bypass switch detection unit is further used to generate a bypass switch 100 closing detection signal when the bypass switch 100 is successfully closed; the bridge arm driving unit 420 is further used to control the first bridge arm to be disconnected according to the bypass switch 100 closing detection signal.

[0119] In this embodiment, after detecting that a fault has occurred in the energy storage submodule, the corresponding bypass switch 100 and power unit 210 can be controlled to perform corresponding actions to bypass the energy storage submodule, utilizing the fast conduction characteristics of the first bridge arm to quickly bypass the energy storage submodule, and utilizing the stability of the bypass switch 100 to provide a stable and reliable bypass path for the energy storage submodule. The bypass switch detection unit detects the state of the bypass switch 100. If the bypass switch 100 receives a bypass switch closing control signal and the bypass switch 100 successfully performs a conduction operation according to the bypass switch closing control signal, it indicates that the bypass switch 100 has been successfully closed. In the case where the bypass switch 100 is successfully closed, the battery unit 240 has been bypassed, and the first bridge arm can be controlled to be disconnected to prevent the first bridge arm from being in a long-term conductive state and causing damage to the device, thereby achieving the purpose of saving energy consumption.

[0120] In some embodiments, the main control module 300 also includes a bridge arm detection unit, which is used to detect the state of the first bridge arm and generate a bridge arm refusal detection signal when the first bridge arm refuses to move; the battery switch drive unit 430 is also used to control the battery switch unit 220 between the battery unit 240 and the power unit 210 to disconnect according to the bridge arm refusal detection signal.

[0121] In this embodiment, at least one bypass switch 100 is connected in parallel to the first bridge arm within each power unit 210. The bridge arm detection unit detects the status of the first bridge arm. If the first bridge arm receives a bridge arm conduction control signal but fails to perform a conduction action, it is determined that the first bridge arm has failed to operate. If the bypass switch 100 and the first bridge arm fail to operate, the battery switch drive unit 430 can control the battery switch unit 220 between the battery unit 240 and the power unit 210 to disconnect according to the bridge arm failure detection signal. When the battery unit 240 is isolated, the first bridge arm is bypassed by overvoltage breakdown due to the continuous increase in the capacitor voltage in the charging state, thereby providing multiple bypass measures for the energy storage submodule, improving the stability of the bypass solution of the energy storage submodule, and avoiding safety hazards such as battery overcharging caused by the failure of the energy storage submodule to bypass in time.

[0122] In some embodiments, the control device further includes a current regulating unit, which is configured to control the branch current of the energy storage submodule to remain within a preset safety current range before the first bridge arm is disconnected according to the bridge arm conduction control signal.

[0123] In this embodiment, since the current flowing through the energy storage submodule is relatively large, the branch current of the energy storage submodule is controlled by the current regulating unit to remain within a preset safe current range, and then the first bridge arm is controlled to be disconnected. This can avoid the problem of excessive current flowing through the first bridge arm, which may cause a safety hazard in the disconnection operation.

[0124] In some embodiments, the current regulating unit is further configured to control the branch current of the energy storage submodule to recover to the operating current range before the first bridge arm is disconnected according to the bridge arm conduction control signal after the first bridge arm is disconnected.

[0125] In this embodiment, after the battery switch unit 220 is disconnected, the power unit 210 and the battery unit 240 are isolated, and the output side of the power unit 210 is bypassed. The branch current of the energy storage submodule is restored to the operating current range before the first bridge arm is disconnected through the current regulation unit, so that the energy storage system is restored to a normal working state, ensuring the normal operation of the energy storage system.

[0126] The present application provides an energy storage system. Figure 12As shown, the energy storage system includes: multiple bypass switches 100, multiple energy storage submodules 200, and a main control module 300. The multiple energy storage submodules 200 are connected in series, and the multiple bypass switches 100 are connected in parallel with the multiple energy storage submodules 200 in a one-to-one correspondence. The energy storage submodule 200 includes a power unit 210, a battery unit 240, and a battery switch unit 220. The power unit 210 is connected to the battery unit 240 via the battery switch unit 220, and the bypass switch 100 is connected in parallel with one of the bridge arms of the power unit 210. After detecting a fault in the energy storage submodule 200, the main control module 300 controls the energy storage submodule 200 to bypass and disconnects the corresponding battery unit 240 from the power unit 210.

[0127] In this embodiment, by providing a bypass switch 100 in parallel with one of the bridge arms of the power unit 210, multiple bypass paths can be provided for the energy storage submodule 200, achieving reliable bypass redundancy for the failed submodule. In the event that any bypass path fails to operate, the energy storage submodule 200 can be bypassed through other bypass measures without affecting the normal operation of the entire energy storage system. On the other hand, by providing a power unit 210 connected to the battery unit 240 via the battery switch unit 220, the main control module 300 can control the corresponding battery unit 240 to be disconnected from the power unit 210 after detecting a failure in the energy storage submodule 200. This not only prevents the impact of failures in individual energy storage submodules 200 from being amplified, but also allows the energy storage submodule 200 to be bypassed by causing an overvoltage breakdown of one of the bridge arms when the battery unit 240 is isolated, thereby ensuring that the energy storage submodule 200 has multiple bypass measures and achieving electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure in the energy storage submodule 200.

[0128] In some embodiments, the energy storage system in this embodiment may be an energy storage valve system, which may be connected to an AC power grid or a DC power grid.

[0129] In some embodiments, see Figure 13 As shown, the power unit 210 includes at least a first bridge arm IGBT1, a second bridge arm IGBT2, and a bus capacitor C1. The first bridge arm IGBT1 and the second bridge arm IGBT2 are connected in series to form a bridge arm circuit. The bus capacitor C1 is connected in parallel with the bridge arm circuit. Both sides of the first bridge arm IGBT1 can serve as the output side of the power unit 210, and the bypass switch 100 is connected in parallel with the output side of the power unit 210.

[0130] In this embodiment, the first bridge arm IGBT1 and the second bridge arm IGBT2 are connected in series to form the power unit 210. The power unit 210 can be controlled by the main control module 300 to charge or discharge the battery unit 240. The bypass switch 100 is connected in parallel with the first bridge arm IGBT1. This design provides two bypass paths for the energy storage submodule 200. Upon detecting a failure in the energy storage submodule 200, the corresponding battery unit 240 can be disconnected from the power unit 210. Thus, while isolating the battery unit 240, the energy storage submodule 200 can be bypassed by causing an overvoltage breakdown in one of the bridge arms due to the continuous increase in the capacitor voltage under charge. This ensures that the energy storage submodule 200 has multiple bypass measures and, in the event of a failure in the energy storage submodule 200, electrically isolates the battery unit 240 from the power unit 210.

[0131] In some embodiments, the first bridge arm IGBT1 can be a lower bridge arm, and the second bridge arm IGBT2 can be an upper bridge arm. The first bridge arm IGBT1 and the second bridge arm IGBT2 are connected in series to form a bridge arm circuit. The two ends of the bridge arm circuit are respectively connected to the two ends of the bus capacitor C1, and the common node of the first bridge arm IGBT1 and the second bridge arm IGBT2 is connected to other energy storage sub-modules 200 or other functional circuits.

[0132] In some embodiments, the first bridge arm IGBT1 can be an upper bridge arm, and the second bridge arm IGBT2 can be a lower bridge arm. The first bridge arm IGBT1 and the second bridge arm IGBT2 are connected in series to form a bridge arm circuit. The two ends of the bridge arm circuit are respectively connected to the two ends of the bus capacitor C1, and the common node of the first bridge arm IGBT1 and the second bridge arm IGBT2 is connected to other energy storage sub-modules 200 or other functional circuits.

[0133] In some embodiments, the first bridge arm IGBT1 and the second bridge arm IGBT2 may be IGBT devices or MOS devices.

[0134] In some embodiments, see Figure 13 As shown, the bypass switch 100 may include one or more sub-switches K0 . In the case where the bypass switch 100 includes multiple sub-switches K0 , the multiple sub-switches K0 may be arranged in parallel.

[0135] In some embodiments, see Figure 13 As shown, the battery switch unit 220 includes a first switch K1 and a second switch K2, wherein the two ends of the first switch K1 are respectively connected to the first end of the power unit 210 and the first end of the battery unit 240, and the two ends of the second switch K2 are respectively connected to the second end of the power unit 210 and the second end of the battery unit 240.

[0136] In some embodiments, the battery unit 240 may be composed of one or more battery cells BAT.

[0137] In some embodiments, the main control module 300 may include multiple sub-module controllers, which are respectively connected to multiple energy storage sub-modules 200, and each sub-module controller is used to control the working status of the corresponding power unit 210, bypass switch 100 and battery switch unit 220.

[0138] In some embodiments, after detecting that a fault has occurred in the energy storage submodule 200, the main control module 300 sends a bypass switch closing control signal to the corresponding bypass switch 100 and sends a bridge arm conduction control signal to the first bridge arm IGBT1; wherein, the bypass switch 100 is used to perform a closing operation according to the bypass switch closing control signal, and the first bridge arm IGBT1 performs a conduction operation according to the bridge arm conduction control signal.

[0139] In this embodiment, the bypass switch 100 and the first bridge arm IGBT1 can set two bypass paths for the energy storage sub-module 200. After detecting that a fault has occurred in the energy storage sub-module 200, a bypass switch closing control signal is sent to the corresponding bypass switch 100, and a bridge arm conduction control signal is sent to the first bridge arm IGBT1. At this time, the first bridge arm IGBT1 and the bypass switch 100 can perform the conduction operation at the same time, providing multiple bypass paths for the energy storage sub-module 200.

[0140] In this embodiment, if the bypass switch 100 cannot be normally disconnected after receiving the bypass switch closing control signal, it indicates that the bypass switch 100 has a refusal to operate. If the bypass switch 100 refuses to operate, the bypass switch 100 is in the open position and the first bridge arm IGBT1 cannot be normally turned on. At this time, the battery switch unit 220 is disconnected, and the battery unit 240 is disconnected from the power unit 210. When the battery unit 240 is isolated, the bus capacitor C1 can be continuously charged to gradually increase the voltage across its two ends, causing the first bridge arm IGBT1 to overvoltage and break down, thereby achieving the purpose of bypassing the energy storage submodule 200. This ensures that the energy storage submodule 200 has multiple bypass measures and realizes electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure of the energy storage submodule 200.

[0141] In some embodiments, the main control module 300 can monitor the branch current of the bypass switch 100 or the branch current on the power unit 210 to determine whether the bypass switch 100 or the first bridge arm IGBT1 has a refusal to operate. For example, if the branch current of the bypass switch 100 is greater than the first preset current, it indicates that the bypass switch 100 has refused to operate. If the current flowing through the first bridge arm IGBT1 is greater than the second preset current, it indicates that the first bridge arm IGBT1 has a refusal to operate.

[0142] In some embodiments, the main control module 300 is further configured to control the corresponding battery switch unit 220 to be disconnected when the bypass switch 100 or the first bridge arm IGBT1 fails to operate.

[0143] In this embodiment, the bypass switch 100 and the first bridge arm IGBT1 can set two bypass paths for the energy storage submodule 200. If the bypass switch 100 or the first bridge arm IGBT1 fails to operate, the main control module 300 controls the corresponding battery switch unit 220 to disconnect, and isolates the battery unit 240. In the charging state, the capacitor voltage across the bus capacitor C1 continues to increase, causing the first bridge arm IGBT1 to overvoltage and break down, thereby bypassing the energy storage submodule 200. This ensures that the energy storage submodule 200 has multiple bypass measures and realizes electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure in the energy storage submodule 200.

[0144] If the first bridge arm IGBT1 refuses to operate, the bypass switch 100 is in the open position, and the first bridge arm IGBT1 cannot be turned on normally. At this time, the battery switch unit 220 is disconnected, and the battery unit 240 is disconnected from the power unit 210. When the battery unit 240 is isolated, the bus capacitor C1 can be continuously charged to gradually increase the voltage across its two ends, causing the first bridge arm IGBT1 to overvoltage and break down, thereby achieving the purpose of bypassing the energy storage submodule 200, ensuring that the energy storage submodule 200 has multiple bypass measures, and realizing electrical isolation between the battery unit 240 and the power unit 210 in the event of a failure of the energy storage submodule 200.

[0145] In some embodiments, the main control module 300 is further configured to control the first bridge arm IGBT1 to be disconnected and the battery switch unit 220 to be disconnected when the bypass switch 100 is successfully closed.

[0146] In this embodiment, the main control module 300 is also used to control the first bridge arm IGBT1 to be disconnected and the battery switch unit 220 to be disconnected when the bypass switch 100 is successfully closed. At this time, the bypass switch 100 can successfully bypass the energy storage submodule 200. In order to avoid the impact of the faulty submodule on the energy storage system, the battery unit 240 can be isolated from the energy storage system by setting the battery switch unit 220 to be disconnected, thereby improving the stability of the energy storage system.

[0147] In some embodiments, the main control module 300 is further configured to control the first bridge arm IGBT1 to remain turned on when the bypass switch 100 fails to close, and to control the battery switch unit 220 to be turned off when the first bridge arm IGBT1 is successfully turned on.

[0148] In this embodiment, when the bypass switch 100 fails to close, the energy storage submodule 200 can still be successfully bypassed by keeping the first bridge arm IGBT1 turned on. When the first bridge arm IGBT1 is turned on successfully, the battery switch unit 220 is controlled to be disconnected, and the battery unit 240 is isolated from the energy storage system, thereby avoiding the impact of the faulty submodule on the energy storage system and improving the stability of the energy storage system.

[0149] In some embodiments, if the first bridge arm IGBT1 is abnormally disconnected, the main control module 300 controls the branch current of the energy storage submodule 200 to remain within a preset safety current range and controls the battery switch unit 220 to be disconnected.

[0150] In this embodiment, if the first bridge arm IGBT1 is abnormally disconnected and cannot be driven normally, the main control module 300 controls the branch current of the energy storage sub-module 200 to remain within a preset safety current range, and then controls the battery switch unit 220 to disconnect, so as to avoid excessive current flowing through the battery switch unit 220, which may cause a safety hazard in the disconnection operation.

[0151] In some embodiments, the first switch K1 or the second switch K2 in the battery switch unit 220 can be selected from switches with different breaking capacities. For example, the first switch K1 and the second switch K2 can be isolating switches or circuit breakers. The types of the first switch K1 and the second switch K2 mainly depend on the protection level of the battery unit 240 and the application scenario of the energy storage submodule 200.

[0152] In this embodiment, because the circuit breaker has the ability to interrupt current, in a bypass strategy using a circuit breaker as a switch, the submodule controller of the energy storage submodule 200 can directly control the circuit breaker to disconnect. However, in some cases, when an isolating switch is used as a switch, the current must be controlled within a safe range before the isolating switch can be disconnected. Therefore, in a solution using an isolating switch as a switch between the battery unit 240 and the power unit 210, the submodule controller needs to add a current reduction step before controlling the battery switch unit 220 to disconnect. Specifically, the submodule controller controls the branch current of the energy storage submodule 200 to remain within a preset safe current range before controlling the battery switch unit 220 to disconnect. This avoids excessive current flowing through the battery switch unit 220, which could lead to safety hazards during the disconnection operation.

[0153] In some embodiments, the submodule controller within the energy storage system can control the branch current of the energy storage submodule 200 through valve control. When the branch current is within a preset safety current range, the submodule controller issues a sub-isolating switch instruction to control the battery switch unit 220 to disconnect. After isolating the battery unit 240, the valve control re-controls the branch current to restore the working state. By continuously increasing the capacitor voltage at both ends of the control point unit in the charging state, the device overvoltage breakdown is caused to achieve bypass of the submodule.

[0154] In some embodiments, see Figure 14 As shown, the energy storage submodule 200 further includes an overvoltage protection unit 250 , which is connected in parallel with the first bridge arm IGBT1 .

[0155] In some embodiments, the overvoltage protection unit 250 includes a thyristor or a breakdown diode.

[0156] In this embodiment, when the voltage across the first bridge arm IGBT 1 reaches a certain level, the overvoltage protection unit 250 is passively triggered, causing it to reliably short-circuit, thereby preventing overvoltage breakdown of the first bridge arm IGBT 1. By providing the overvoltage protection unit 250 in parallel with the first bridge arm IGBT 1, the first bridge arm IGBT 1 can be short-circuited at a voltage threshold significantly lower than the breakdown voltage of the first bridge arm IGBT 1, thereby bypassing the energy storage submodule 200.

[0157] In some embodiments, the energy storage system includes multiple bypass switches 100, multiple energy storage submodules, and a main control module 300. The multiple energy storage submodules are connected in series, and the multiple bypass switches 100 are connected in parallel with the multiple energy storage submodules in a one-to-one correspondence. The energy storage submodules include a power unit 210, a battery unit 240, and a battery switch unit 220. The power unit 210 is connected to the battery unit 240 via the battery switch unit 220, and the bypass switch 100 is connected in parallel with the output side of the power unit 210. Upon detecting a failure in an energy storage submodule, the main control module 300 controls the disconnection between the corresponding battery unit 240 and the power unit 210. When isolating the battery unit 240, the energy storage submodule is bypassed by continuously increasing the capacitor voltage in a charged state, causing one of the bridge arms to overvoltage and break down. This ensures that the energy storage submodule has multiple bypass measures and electrically isolates the battery unit 240 from the power unit 210 in the event of an energy storage submodule failure.

[0158] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0159] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0160] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the electronic device embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0161] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0162] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0163] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A control method for an energy storage submodule, characterized in that: The energy storage submodule includes a power unit and a battery unit, and the first bridge arm in the power unit is connected in parallel with at least one bypass switch; the control method includes: Detecting whether the energy storage submodule fails, and generating a submodule failure detection signal when the energy storage submodule fails; The bypass switch and the first bridge arm are controlled to be turned on according to the submodule fault detection signal, so as to bypass the energy storage submodule.

2. The control method according to claim 1, characterized in that: The controlling the bypass switch and the first bridge arm to be turned on according to the submodule fault detection signal includes: generating a bypass switch closing control signal according to the submodule fault detection signal to control the bypass switch to be turned on; A bridge arm conduction control signal is generated according to the submodule fault detection signal to control the first bridge arm to be conducted.

3. The control method according to claim 1, wherein: The control method further includes: The state of the bypass switch is detected, and when the bypass switch refuses to operate, the battery switch unit between the battery unit and the power unit is controlled to be disconnected.

4. The control method according to claim 1, wherein: The control method further includes: The state of the first bridge arm is detected, and when the first bridge arm refuses to operate, the battery switch unit between the battery unit and the power unit is controlled to be disconnected.

5. The control method according to claim 1, characterized in that: The control method further includes: The states of the first bridge arm and the bypass switch are detected, and when the first bridge arm and the bypass switch refuse to operate, the battery switch unit between the battery unit and the power unit is controlled to be disconnected.

6. The control method according to claim 1, characterized in that: The control method further includes: detecting a state of the bypass switch and generating a bypass switch closing detection signal when the bypass switch is successfully closed; The first bridge arm is controlled to be disconnected according to the bypass switch closing detection signal.

7. The control method according to claim 1, characterized in that: The control method further includes: The state of the bypass switch is detected, and the first bridge arm is controlled to remain turned on when the bypass switch refuses to operate.

8. The control method according to claim 5, characterized in that: Before the battery switch unit is disconnected, the method further includes: The branch current of the energy storage submodule is controlled to remain within a preset safe current range.

9. The control method according to claim 8, characterized in that: After the battery switch unit is disconnected, the method further comprises: The branch current of the energy storage submodule is controlled to recover to the operating current range before the first bridge arm is disconnected.

10. A control device for an energy storage submodule, characterized in that: The energy storage submodule includes a power unit and a battery unit. The first bridge arm in the power unit is connected in parallel with at least one bypass switch. The control device includes: A main control module is used to detect whether the energy storage submodule has a fault and generate a submodule fault detection signal when the energy storage submodule has a fault; The switch driving module is used to control the bypass switch and the first bridge arm to be turned on according to the submodule fault detection signal, so as to bypass the energy storage submodule.

11. The control device according to claim 10, characterized in that: The switch driving module further includes: A battery switch driving unit is used to control the battery switch unit between the battery unit and the power unit to be disconnected according to the submodule fault detection signal.

12. The control device according to claim 10, characterized in that The switch driving module includes: A bypass switch driving unit, configured to generate a bypass switch closing control signal according to the submodule fault detection signal, so as to control the bypass switch to be turned on; The bridge arm driving unit is used to generate a bridge arm conduction control signal according to the submodule fault detection signal to control the first bridge arm to be conducted.

13. The control device according to claim 12, characterized in that: The main control module includes: a bypass switch detection unit, configured to detect a state of the bypass switch and generate a bypass switch refusal detection signal when the bypass switch refuses to operate; The bridge arm driving unit is further configured to generate the bridge arm conduction control signal according to the bypass switch refusal detection signal, so as to control the first bridge arm to remain conductive.

14. The control device according to claim 13, characterized in that The bypass switch detection unit is further configured to generate a bypass switch closing detection signal when the bypass switch is successfully closed; The bridge arm driving unit is further configured to control the first bridge arm to be disconnected according to the bypass switch closing detection signal.

15. The control device according to claim 11, characterized in that The main control module also includes: a bridge arm detection unit, configured to detect a state of the first bridge arm and generate a bridge arm refusal detection signal when the first bridge arm refuses to move; The battery switch driving unit is further configured to control the battery switch unit between the battery unit and the power unit to be disconnected according to the bridge arm refusal detection signal.

16. The control device according to claim 12, characterized in that The control device further comprises: A current regulating unit is used to control the branch current of the energy storage submodule to remain within a preset safe current range before the first bridge arm is disconnected according to the bridge arm conduction control signal.

17. The control device according to claim 16, characterized in that The current regulating unit is further configured to control the branch current of the energy storage submodule to recover to the operating current range before the first bridge arm is disconnected after the first bridge arm is disconnected according to the bridge arm conduction control signal.

18. An energy storage system, characterized in that: The energy storage system includes: a plurality of bypass switches, a plurality of energy storage submodules and a main control module; A plurality of the energy storage submodules are connected in series, and each energy storage submodule is connected in parallel with at least one bypass switch; The energy storage submodule includes a power unit, a battery unit and a battery switch unit, the power unit is connected to the battery unit via the battery switch unit, and the bypass switch is connected in parallel with one of the bridge arms of the power unit; The main control module is used to execute the control method according to any one of claims 1 to 9.

19. The energy storage system according to claim 18, characterized in that: The power unit includes at least a first bridge arm, a second bridge arm, and a bus capacitor. The first bridge arm and the second bridge arm are connected in series to form a bridge arm circuit. The first bridge arm is connected in parallel with the bypass switch, and the bus capacitor is connected in parallel with the bridge arm circuit.

20. The energy storage system according to any one of claims 19, characterized in that: The energy storage submodule further includes: An overvoltage protection unit is connected in parallel with the first bridge arm, and is used to bypass the first bridge arm when the voltage at both ends of the first bridge arm is overvoltage.

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