Combined charging and discharging structure and energy storage DC cabinet

Abstract

This invention belongs to the technical field of electrical energy storage, specifically relating to a combined charging and discharging structure, including a separately configured BMS module and multiple battery packs connected in series. Each battery pack contains a main positive contactor, a bypass contactor, and a cell module. The BMS module has multiple pairs of first and second control terminals. The main positive contactor is electrically connected to both the cell module and the first control terminal, and the bypass contactor is electrically connected to both the cell module and the second control terminal. The bypass contactors are connected in parallel with the cell module. This invention can disconnect the circuit of a faulty battery pack through the control of the BMS module and the bypass contactor without affecting the normal operation of other battery packs, offering extremely high safety, operational flexibility, and controllability. Furthermore, this invention also provides an energy storage DC cabinet.

Description

Technical Field

[0001] This utility model belongs to the technical field of electrical energy storage, specifically relating to a combined charging and discharging structure and an energy storage DC cabinet. Background Technology

[0002] Energy storage cabinets can store the required electrical energy in a limited space. Currently, commercial and industrial energy storage cabinets will shut down due to a power outage caused by a malfunction in one of the battery cells or a battery pack. This severely reduces the time utilization rate of the energy storage cabinet and can cause significant losses to users' revenue. Therefore, there is an urgent need to propose a new technical solution to address these problems. Utility Model Content

[0003] One of the objectives of this invention is to provide a combined charging and discharging structure that addresses the shortcomings of existing technologies and effectively solves the problem of battery pack malfunctions affecting the normal operation of the entire circuit.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A combined charging and discharging structure includes a separately configured BMS module and multiple battery packs connected in series. Each battery pack contains a main positive contactor, a bypass contactor, and a cell module. The BMS module has multiple pairs of first control terminals and second control terminals. In a single battery pack, the main positive contactor is electrically connected to the cell module and the first control terminal, and the bypass contactor is electrically connected to the cell module and the second control terminal. The bypass contactor is connected in parallel with the cell module.

[0006] As an improvement to the combined charging and discharging structure of this utility model, in a single battery pack, the bypass contactor is connected in series with the first fuse, one end of the first fuse is electrically connected to the cell module and the MSD maintenance switch respectively, and the main positive contactor, the cell module and the MSD maintenance switch are connected in series in sequence.

[0007] As an improvement to the combined charging and discharging structure of this utility model, the battery cell module has multiple battery cells connected in series.

[0008] As an improvement to the combined charging and discharging structure of this utility model, the number of cells in each of the battery packs may be the same or different.

[0009] The second objective of this utility model is to provide an energy storage DC cabinet, which has a PDU high-voltage box and a combined charging and discharging structure. The BMS module is set in the PDU high-voltage box, and multiple battery packs are connected in series to the main circuit of the PDU high-voltage box.

[0010] As an improvement to the energy storage DC cabinet of this utility model, it also has a DC-DC module, and the electrical output terminal of the PDU high-voltage box is connected to the DC-DC module.

[0011] As an improvement of the energy storage DC cabinet of this utility model, the main circuit is connected to the positive output terminal of the PDU high-voltage box through a first contactor, the main circuit is connected to the negative output terminal of the PDU high-voltage box through a second contactor, the DC-DC module is connected to the positive output terminal and the negative output terminal of the power supply respectively, and the BMS module is connected to the main circuit through the first contactor and the second contactor.

[0012] As an improvement of the energy storage DC cabinet of this utility model, the main circuit has a circuit breaker switch.

[0013] As an improvement of the energy storage DC cabinet of this utility model, the main circuit also has a second fuse, and the battery pack, the circuit breaker switch and the second fuse are connected in sequence.

[0014] As an improvement of the energy storage DC cabinet of this utility model, the main circuit also has a Hall sensor. The battery pack, the circuit breaker switch and the Hall sensor are connected in sequence. The Hall sensor is mainly used in the high-voltage box to monitor electrical parameters such as current and voltage in real time, and to assist in realizing functions such as overcurrent protection and short circuit protection, so as to ensure that the high-voltage box can cut off the circuit in time under abnormal operating conditions.

[0015] The beneficial effects of this utility model are as follows: When all battery packs of this utility model are operating normally without faults, the BMS module controls the electromagnetic coils of the main positive contactors of each battery pack through multiple pairs of first control terminals, so that each main positive contactor is in the energized state. At the same time, the BMS module controls the electromagnetic coils of the bypass contactors of each battery pack through multiple pairs of second control terminals, so that each bypass contactor is in the energized state. At this time, the cell modules of multiple battery packs are connected in series in the power circuit and can all participate in charging / discharging operation. When one of the battery packs fails, the BMS module controls the electromagnetic coil of the main positive contactor of that battery pack through the first control terminal, so that the corresponding main positive contactor is in the energized state. The BMS module controls the electromagnetic coil of the bypass contactor of that battery pack through the second control terminal, so that the corresponding bypass contactor is in the energized state. That is, the circuit of the faulty battery pack can be disconnected in a timely and rapid manner without affecting the normal charging / discharging operation of other battery packs, effectively solving the problem that battery pack abnormalities affect the normal operation of the entire circuit. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0017] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this utility model.

[0018] The components include: 1. BMS module; 2. Battery pack; 20. Cell module; 3. PDU high-voltage box; 4. DC-DC module. Detailed Implementation

[0019] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0020] Furthermore, the terms "first," "second," etc., are used solely for descriptive purposes to distinguish different objects, not to describe a specific order or primary / secondary relationship, and should not be construed as indicating or implying relative importance. The term "and / or" in this application merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "or" relationship.

[0021] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] The inventors discovered that in existing energy storage cabinets, when a single cell or battery pack malfunctions, the entire energy storage cabinet will stop operating, affecting the time utilization rate of the energy storage cabinet. Furthermore, the output voltage of the DC energy storage cabinet is unstable, and when multiple DC energy storage cabinets are connected to the grid, circulating current problems will occur, affecting the operating efficiency of the energy storage cabinet.

[0023] The following is in conjunction with the appendix Figures 1-2 The present invention will be further described in detail with reference to specific embodiments, but this is not intended to limit the present invention.

[0024] Example 1

[0025] A combined charge-discharge structure, such as Figure 1 As shown, the system includes a BMS module 1, which has multiple pairs of first and second control terminals, and a battery pack 2. The battery pack 2 has a main positive contactor, a bypass contactor, and a cell module 20 inside. The main positive contactor is electrically connected to the cell module 20 and the first control terminal, respectively. The bypass contactor is electrically connected to the cell module 20 and the second control terminal, respectively. The bypass contactor is connected in parallel with the cell module 20. Multiple battery packs 2 are connected in series and are set separately from the BMS module 1. The BMS module 1 can be installed on multiple stacked battery packs 2 to form a combined charging and discharging structure.

[0026] Preferably, in a single battery pack 2, a bypass contactor is connected in series with a first fuse, one end of which is electrically connected to the cell module 20 and the MSD maintenance switch, respectively, and the main positive contactor, the cell module 20 and the MSD maintenance switch are connected in series in sequence.

[0027] The cell module 20 has multiple cells connected in series, and the number of cells in each battery pack 2 may be the same or different.

[0028] Since the BMS module is actually a battery management module, it has a BMS main control board containing a main control circuit. This main control circuit has multiple pairs of first and second control terminals. The main control circuit can apply a required voltage signal to the contactor coil as needed, thereby controlling the contactor's electromagnetic coil to achieve the engaged or disengaged state. When the voltage value of the electrical signal reaches the required value, the electromagnetic coil engages; when the voltage value drops to a preset value, the electromagnetic coil disengages, thus effectively controlling the charging and discharging safety of the battery pack.

[0029] Example 2

[0030] A type of energy storage DC cabinet, such as Figure 2 As shown, the cabinet contains a PDU high-voltage box 3 and a combined charging and discharging structure of Embodiment 1. The BMS module 1 is installed in the PDU high-voltage box 3. Multiple battery packs 2 are connected in series to the main circuit of the PDU high-voltage box 3. In a single battery pack 2, the cell module, the main positive contactor, and the MSD maintenance switch are connected in series to form the main power circuit of the battery pack 2. Furthermore, the B+ signal terminal of the battery pack 2 is directly connected to the main positive contactor, and the B- signal terminal of the battery pack 2 is directly connected to the MSD maintenance switch. The bypass contactor and the first fuse FU1 in the battery pack 2 are connected in series to form a bypass power circuit. The bypass power circuit is connected in parallel to the main power circuit. One end of the first fuse FU1 is connected to the circuit area between the cell module and the MSD maintenance switch, and one end of the bypass contactor is connected to the circuit area between the main positive contactor and the B+ signal terminal of the battery pack.

[0031] Specifically, the BMS module controls the electromagnetic coil of the main positive contactor KMn1 of battery pack 2 through pins KMn1+ and KMn1- in its main control circuit. The BMS module controls the electromagnetic coil of the bypass contactor KMn2 of battery pack 2 through pins KMn2+ and KMn2- in its main control circuit. Each pair of KMn1+ and KMn1- control pins is connected to the positive and negative terminals of the coil of the main positive contactor KMn1, and each pair of KMn2+ and KMn2- control pins is connected to the positive and negative terminals of the coil of the bypass contactor KMn2, and so on. The BMS module can control all the main positive contactors and bypass contactors.

[0032] Preferably, the energy storage DC cabinet has multiple battery packs 2, the number of battery packs 2 can be at least 2 to 8, and the cabinet also has a PDU high-voltage box 3 and a DC-DC module 4.

[0033] Specifically, the main circuit of the PDU high-voltage box 3 includes a circuit breaker switch QS, a second fuse FU2, a main positive contactor KMA, a Hall sensor hall, and a main negative contactor KMB. The BMS module 1, the main positive contactor KMA, and the main negative contactor KMB can control the electrical output of the PDU high-voltage box 3. The main positive contactor KMA can be the first contactor, and the main negative contactor KMB can be the second contactor. The main circuit is connected to the positive power output terminal P+ of the PDU high-voltage box 3 through the first contactor, and the main circuit is connected to the negative power output terminal P- of the PDU high-voltage box 3 through the second contactor. The DC-DC module 4 is connected to the positive power output terminal P+ and the negative power output terminal P-, respectively. The BMS module 1 is connected to the main circuit through the first and second contactors. The positive and negative terminals of the contactor coils are connected to the corresponding pins in the main control circuit of the BMS module, so that the BMS module 1 can effectively control the operation of the first and second contactors.

[0034] Inside the cabinet, the B+ and B- signal terminals of the n battery packs between battery pack-1 and battery pack-n are connected in series. Then, the B+ signal terminal of battery pack-1 and the B- signal terminal of battery pack-n are connected to the B+ and B- contacts of PDU high-voltage box 3, respectively. The P+ and P- contacts of PDU high-voltage box 3 are connected to the IN+ and IN- signal terminals of DC-DC module 4, respectively. Finally, the voltage / current output of the energy storage DC cabinet is completed by the OUT+ and OUT- signal terminals of DC-DC module 4.

[0035] When all battery packs 2 are operating normally without faults, BMS module 1 controls the electromagnetic coil of the main positive contactor KMn1 of battery pack-n through pins KMn1+ and KMn1-, so that the main positive contactor KMn1 is in the energized state; and controls the electromagnetic coil of the bypass contactor KMn2 of battery pack-n through pins KMn2+ and KMn2-, so that the bypass contactor KMn2 of battery pack-n is in the open state; at this time, the cell modules 20 of n battery packs 2 are connected in series in the power circuit and can all participate in charging / discharging operation.

[0036] When battery pack-n fails, BMS module 1 controls the electromagnetic coil of the main positive contactor KMn1 of battery pack-n through pins KMn1+ and KMn1-, causing the main positive contactor KMn1 to be in the open state; and controls the electromagnetic coil of the bypass contactor KMn2 of battery pack-n through pins KMn2+ and KMn2-, causing the bypass contactor KMn2 of battery pack-n to be in the closed state. At this time, the cell module of the faulty battery pack is isolated and protected in the power circuit, but the bypass power circuit is connected, so the current of the energy storage system composed of normal battery packs in the cabinet can still flow normally.

[0037] Preferably, the DC-DC module 4 can ensure that the energy storage DC cabinet is not affected by the voltage and current fluctuations of the battery pack, and outputs a stable voltage / current, thus preventing circulating current problems when multiple energy storage DC cabinets are connected to the grid. In a single battery pack 2, the first fuse FU1 of the bypass power circuit can prevent the cell module 20 from being continuously short-circuited and damaged when the bypass contactor experiences thermal adhesion (inability to disconnect).

[0038] Clearly, when one of the battery packs in the energy storage DC cabinet malfunctions, it ensures that the faulty battery pack is isolated and protected, while also guaranteeing the normal charging and discharging operation of the entire energy storage DC cabinet, greatly improving the time utilization rate of the energy storage DC cabinet. In addition, the introduced DC-DC module can avoid the circulating current problem when multiple cabinets combine, which promotes the safety and operating efficiency of the energy storage DC cabinet.

[0039] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the utility model are within the protection scope of the utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the utility model.

Claims

1. A combined charging and discharging structure, characterized in that, include: The BMS module (1) has multiple pairs of first control terminals and second control terminals; The battery pack (2) has a main positive contactor, a bypass contactor and a cell module (20) inside. The main positive contactor is electrically connected to the cell module (20) and the first control terminal respectively. The bypass contactor is electrically connected to the cell module (20) and the second control terminal respectively. The bypass contactor is connected in parallel with the cell module (20). Multiple battery packs (2) are connected in series and are set separately from the BMS module (1).

2. The combined charging and discharging structure as described in claim 1, characterized in that: The bypass contactor is connected in series with the first fuse, one end of which is electrically connected to the cell module (20) and the MSD maintenance switch respectively. The main positive contactor, the cell module (20) and the MSD maintenance switch are connected in series in sequence.

3. The combined charging and discharging structure as described in claim 1 or 2, characterized in that: The battery cell module (20) has multiple battery cells connected in series.

4. The combined charging and discharging structure as described in claim 3, characterized in that: The number of cells in each of the battery packs (2) may be the same or different.

5. A DC energy storage cabinet, characterized in that: The device has a PDU high-voltage box (3) and a combined charging and discharging structure as described in any one of claims 1 to 4. The BMS module (1) is disposed in the PDU high-voltage box (3), and multiple battery packs (2) are connected in series to the main circuit of the PDU high-voltage box (3).

6. The energy storage DC cabinet as described in claim 5, characterized in that: It also has a DC-DC module (4), and the electrical output terminal of the PDU high-voltage box (3) is connected to the DC-DC module (4).

7. The energy storage DC cabinet as described in claim 6, characterized in that: The main circuit is connected to the positive power output terminal of the PDU high voltage box (3) through the first contactor, and the main circuit is connected to the negative power output terminal of the PDU high voltage box (3) through the second contactor. The DC-DC module (4) is connected to the positive power output terminal and the negative power output terminal respectively, and the BMS module (1) is connected to the main circuit through the first contactor and the second contactor.

8. The energy storage DC cabinet as described in any one of claims 5 to 7, characterized in that: The main circuit has a circuit breaker switch.

9. The energy storage DC cabinet as described in claim 8, characterized in that: The main circuit also has a second fuse, and the battery pack (2), the circuit breaker switch and the second fuse are connected in sequence.

10. The energy storage DC cabinet as described in claim 8, characterized in that: The main circuit also has a Hall sensor, and the battery pack (2), the circuit breaker switch and the Hall sensor are connected in sequence.

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