Charging and discharging circuit, control method thereof, high-voltage box and energy storage system

Abstract

The invention discloses a charging and discharging circuit, a high-voltage box, an energy storage system and a control method. The charging and discharging circuit comprises a main positive loop and a main negative loop. A charge-discharge control module is arranged on the main positive loop, one end of the charge-discharge control module is electrically connected with the positive electrode of the battery cluster, and the other end is electrically connected with the positive electrode of the power supply equipment. A main negative control module is arranged on the main negative loop, one end of the main negative control module is electrically connected with the cathode of the battery cluster, and the other end is electrically connected with the cathode of the power supply equipment. The charging and discharging control module and the main negative control module are configured to enable the main positive loop, the main negative loop, the battery cluster and the power supply equipment to jointly form one of a pre-charging loop, a charging loop, a charging-to-discharging loop, a discharging loop and a discharging-to-charging loop, and the charging loop is switched to the discharging loop after being transited by the charging-to-discharging loop; or the discharging loop is switched to the charging loop after being transited by the discharging-to-charging loop.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a charging and discharging circuit, a high-voltage box, an energy storage system, and a control method for the charging and discharging circuit. Background Technology

[0002] Currently, high-voltage boxes are typically used as circuit bridges between energy storage batteries and (uninterruptible) power supply (UPS) equipment. However, common high-voltage boxes usually only have one circuit for charging and discharging the energy storage battery. After the battery charging is cut off, the battery management module disconnects the main positive and negative relays on the high-voltage box circuit. If the battery needs to enter a discharging state, the battery management module needs to re-close the main positive and negative relays, which usually takes some time. But if the power supply equipment needs to power loads that cannot be interrupted, such as data centers, existing high-voltage boxes cannot support the immediate discharge of the battery after charging is cut off, thus failing to meet the requirements of this application. Summary of the Invention

[0003] This application provides a charging and discharging circuit, a high-voltage box, an energy storage system, and a control method for the charging and discharging circuit.

[0004] The charging and discharging circuit of this application includes a main positive circuit and a main negative circuit. A charging and discharging control module is provided on the main positive circuit. One end of the charging and discharging control module is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the positive terminal of the power supply device. A main negative control module is provided on the main negative circuit. One end of the main negative control module is electrically connected to the negative terminal of the battery cluster, and the other end is electrically connected to the negative terminal of the power supply device. The charging and discharging control module and the main negative control module are configured to: enable the main positive circuit, the main negative circuit, the battery cluster, and the power supply device to jointly form one of a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit, and a discharging-to-charging circuit; and switch from the charging circuit to the discharging circuit after transitioning through the charging-to-discharging circuit, or switch from the discharging circuit to the charging circuit after transitioning through the discharging-to-charging circuit.

[0005] In some embodiments, the charge / discharge control module includes a first contactor KM1, a second contactor KM2, a first diode D1, a second diode D2, and a pre-charge unit. The second contactor KM2 and the first contactor KM1 are connected in series between the positive terminal of the battery pack and the power supply device, forming a series combination with a first node N1 and a second node N2, where the current path from the second node N2 to the power supply device is shorter than that from the first node N1. The positive terminal of the first diode D1 is electrically connected to the first node N1, and the negative terminal of the first diode D1 is electrically connected to a third node N3 between the first contactor KM1 and the second contactor KM2; the positive terminal of the second diode D2 is electrically connected to the second node N2, and the negative terminal of the second diode D2 is electrically connected to the third node N3; the pre-charge unit is connected in parallel with the series combination.

[0006] In some embodiments, the pre-charging unit includes a third contactor KM3 connected in series with a pre-charging resistor R, one end of the third contactor KM3 being electrically connected to the first node N1, and one end of the pre-charging resistor R being electrically connected to the second node N2.

[0007] In some embodiments, a first current detection module is also provided on the main positive circuit. The first current detection module is used to detect the current on the main positive circuit. One end of the first current detection module is electrically connected to the positive electrode of the battery cluster, and the other end is electrically connected to the first node N1.

[0008] In some embodiments, a main positive circuit is also provided with a main positive fuse, one end of which is electrically connected to the first current detection module and the other end is electrically connected to the first node N1.

[0009] In some embodiments, the main negative control module includes a main negative contactor KM4, and a second current detection module is also provided on the main negative circuit. The second current detection module is used to detect the current in the main negative circuit. The second current detection module and the main negative contactor KM4 are connected in series between the negative terminal of the battery pack and the negative terminal of the power supply device. The charging and discharging circuit also includes a first circuit breaker QF1, which is connected in series between the power supply device and the second node N2 for switching the main positive circuit; the first circuit breaker QF1 is also connected in series between the power supply device and the main negative contactor KM4 for switching the main negative circuit.

[0010] In some embodiments, the charging and discharging circuit has a pre-charging stage, a charging stage, a charging-to-discharging stage, a discharging stage, and a discharging-to-charging stage. During the pre-charging phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device and connects the main negative contactor KM4 to the negative terminal of the power supply device to form the pre-charging circuit. During the charging phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device, and connects the main negative contactor KM4 to the negative terminal of the power supply device, thereby forming the charging circuit. During the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form the charging-to-discharging circuit. During the discharge phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment, thereby forming the discharge circuit. During the discharge-to-charge phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device, and connects the main negative contactor KM4 to the negative terminal of the power supply device, thereby forming the discharge-to-charge circuit.

[0011] In some embodiments, the battery cluster includes at least one battery pack, and the charging / discharging circuit further includes a battery management module, which includes a master control chip and at least one slave control chip. A first terminal of the master control chip is electrically connected to the first node N1, a second terminal of the master control chip is electrically connected to the second node N2, and a third terminal of the master control chip is electrically connected between the second current detection module and the main negative contactor KM4. Each battery pack corresponds to one slave control chip.

[0012] In some embodiments, the charging and discharging circuit further includes a circuit breaker status detection circuit, one end of which is electrically connected to the fourth terminal of the main control chip, and the other end of which is electrically connected to the fifth terminal of the main control chip. The circuit breaker status detection circuit is used to detect the open and closed state of the first circuit breaker QF1.

[0013] In some embodiments, the charging and discharging circuit further includes a first power supply circuit and a second power supply circuit. The first power supply circuit is electrically connected to both the master control chip and the slave control chip, and is used to supply power to both the master control chip and the slave control chip. The second power supply circuit is electrically connected to both the master control chip and the slave control chip, and is used to supply power to both the master control chip and the slave control chip.

[0014] In some embodiments, the first power supply circuit includes a second circuit breaker QF2, an AC / DC power supply, and a third diode D3. The first terminal of the AC / DC power supply is electrically connected to the live wire via the second circuit breaker QF2, and the second terminal of the AC / DC power supply is electrically connected to the neutral wire. The anode of the third diode D3 is electrically connected to the third terminal of the AC / DC power supply, and the cathode of the third diode D3 is connected to the anodes of both the master control chip and the slave control chip. The fourth terminal of the AC / DC power supply is connected to the cathodes of both the master control chip and the slave control chip.

[0015] In some embodiments, the second power supply circuit includes a third circuit breaker QF3, a DC / DC power supply, and a fourth diode D4. The first terminal of the DC / DC power supply is connected to the first node N1 via the third circuit breaker QF3, and the second terminal of the DC / DC power supply is connected to the negative terminal of the battery cluster via the third circuit breaker QF3. The anode of the fourth diode D4 is electrically connected to the third terminal of the DC / DC power supply, and the cathode of the fourth diode D4 is electrically connected to the anodes of both the master control chip and the slave control chip. The fourth terminal of the DC / DC power supply is electrically connected to the cathodes of both the master control chip and the slave control chip.

[0016] In some embodiments, the cathode of the third diode D3 and the cathode of the fourth diode D4 are electrically connected, and the fourth terminal of the AC / DC power supply is electrically connected to the fourth terminal of the DC / DC power supply; the charging and discharging circuit further includes a spare connector, which includes a positive terminal and a negative terminal. The positive terminal of the spare connector is connected between the cathode of the third diode D3 and the cathode of the fourth diode D4, and the negative terminal of the spare connector is connected between the fourth terminal of the AC / DC power supply and the fourth terminal of the DC / DC power supply.

[0017] In some embodiments, the charging and discharging circuit further includes an indicator light, one end of which is connected between the negative terminal of the third diode D3 and the negative terminal of the fourth diode D4, and the other end is connected between the fourth terminal of the AC / DC power supply and the fourth terminal of the DC / DC power supply.

[0018] This application also provides a high-voltage box, which includes the charging and discharging circuit described in any of the above embodiments.

[0019] This application also provides an energy storage system, which includes a battery cluster, a power supply device, and a high-voltage box as described in any of the above embodiments, wherein the high-voltage box is electrically connected to both the battery cluster and the power supply device.

[0020] This application also provides a control method for a charging and discharging circuit, the charging and discharging circuit including a main positive circuit and a main negative circuit. A charging and discharging control module is provided on the main positive circuit, one end of which is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the positive terminal of a power supply device. A main negative control module is provided on the main negative circuit, one end of which is electrically connected to the negative terminal of the battery cluster, and the other end is electrically connected to the negative terminal of the power supply device. The control method includes: utilizing the cooperation of the charging and discharging control module and the main negative control module to enable the main positive circuit, the main negative circuit, the battery cluster, and the power supply device to switch between a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit, and a discharging-to-charging circuit.

[0021] In some embodiments, the charging and discharging circuit further includes a first circuit breaker QF1, the positive terminal of which is connected to the positive terminal of the power supply device and the return terminal of the main positive circuit, and the negative terminal of which is connected to the negative terminal of the power supply device and the return terminal of the main negative circuit. The charging and discharging control module includes a first contactor KM1, a second contactor KM2, a first diode D1, and a second diode D2. The second contactor KM2 and the first contactor KM1 are connected in series between the positive terminal of the battery pack and the power supply device, forming a series combination with a first node N1 and a second node N2. The current path from the second node N2 to the power supply device is shorter than that from the first node N1. The positive terminal of the first diode D1 is electrically connected to the first node N1, and the negative terminal of the first diode D1 is electrically connected to a third node N3 between the first contactor KM1 and the second contactor KM2. The positive terminal of the second diode D2 is electrically connected to the second node N2, and the negative terminal of the second diode D2 is electrically connected to the third node N3; the pre-charging unit includes a third contactor KM3 and a pre-charging resistor R connected in series. One end of the third contactor KM3 is electrically connected to the first node N1, and one end of the pre-charging resistor R is electrically connected to the second node N2. A first current detection module is also provided on the main positive circuit. One end of the first current detection module is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the first node N1. A second current detection module is also provided on the main negative circuit. The main negative control module includes a main negative contactor KM4. The second current detection module and the main negative contactor KM4 are connected in series between the negative terminal of the battery cluster and the first circuit breaker QF1; the charging and discharging circuit has a pre-charging stage, a charging stage, a charging-to-discharging stage, a discharging stage, and a discharging-to-charging stage; the control method further includes: During the pre-charging phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device and connects the main negative contactor KM4 to the negative terminal of the power supply device to form the pre-charging circuit. During the charging phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device, and connects the main negative contactor KM4 to the negative terminal of the power supply device, thereby forming the charging circuit. During the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form the charging-to-discharging circuit. During the discharge phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment, thereby forming the discharge circuit. During the discharge-to-charge phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply device, and connects the main negative contactor KM4 to the negative terminal of the power supply device, thereby forming the discharge-to-charge circuit.

[0022] In some embodiments, the charging and discharging circuit further includes a battery management module, and the control method further includes: When the battery cluster is fully charged, the battery management module sends a charge-disable signal to the power supply device; When the mains power is disconnected, the battery pack switches from the charging stage to the discharging stage after passing through the charging-to-discharging stage. When the current obtained by the first current detection module is zero, the first contactor KM1 is disconnected until the current obtained by the first current detection module is not zero. When the current obtained by the first current detection module is not zero, the battery cluster enters the discharge stage, controls the first contactor KM1 to close, and controls the second contactor KM2 and the main negative contactor KM4 to remain closed.

[0023] In some embodiments, the charging and discharging circuit further includes a battery management module, and the control method further includes: When the battery cluster is depleted, the battery management module sends a kill signal to the power supply device; After the battery cluster switches from the discharge stage to the charging stage, it switches from the discharge stage to the charging stage. When the current obtained by the first current detection module is zero, the second contactor KM2 is disconnected until the current obtained by the first current detection module is not zero. When the current obtained by the first current detection module is not zero, the battery cluster enters the charging stage, controls the second contactor KM2 to close, and controls the main negative contactor KM4 and the first contactor KM1 to remain closed.

[0024] The charging / discharging circuit, high-voltage box, energy storage system, and control method of this application utilize the coordinated configuration of the charging / discharging control module and the main / negative control module. This allows the main positive circuit, main negative circuit, power supply equipment, and battery cluster to jointly form one of the following circuits: a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit, or a discharging-to-charging circuit. The circuit can switch from the charging circuit to the discharging circuit via the charging-to-discharging circuit, or vice versa. This allows a single hardware circuit to be dynamically adjusted to different current paths, achieving seamless and rapid switching from the charging circuit to the discharging circuit. When the battery cluster needs to be discharged immediately after charging is completed, the charging / discharging circuit does not need to completely disconnect the main circuit and then re-energize. Instead, the current flow direction can be instantly reversed through the state switching of the internal structures of the charging / discharging control module and the main / negative control module. This eliminates the time delay caused by the complete opening and closing of relays in traditional charging / discharging circuits, thus meeting the requirement of uninterruptible power supplies (UPS) to provide truly uninterrupted power to critical loads such as data centers.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein: Figure 1 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 2 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 3 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 4 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 5 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 6 This is a schematic diagram of the charging and discharging circuit of some embodiments of this application; Figure 7 This is a structural schematic diagram of a high-pressure box according to some embodiments of this application; and Figure 8This is a schematic diagram of the energy storage system according to some embodiments of this application. Detailed Implementation

[0027] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0028] In the description of this application, it should be understood that the terms "center", "length", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] Currently, high-voltage boxes are commonly used as circuit bridges between energy storage batteries and (uninterruptible) power supply (UPS) equipment. However, typical high-voltage boxes usually only have one circuit for charging and discharging the energy storage battery. After the battery charging is completed, the battery management module disconnects the main positive and negative relays on the high-voltage box circuit. If the battery needs to enter a discharging state, the battery management module needs to re-close the main positive and negative relays, which usually takes some time. However, if the UPS needs to power loads such as data centers that cannot be powered down, the existing high-voltage boxes cannot support immediate battery discharge after charging is completed, thus failing to meet this application requirement. To solve these problems, this application provides a charging and discharging circuit (such as...) Figure 1 As shown), high-voltage box ( Figure 7 As shown), energy storage system ( Figure 8 (as shown) and a control method for a charging and discharging circuit.

[0033] Please see Figure 1 The charging and discharging circuit includes a main positive circuit and a main negative circuit. A charging and discharging control module is installed on the main positive circuit. One end of the charging and discharging control module is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the positive terminal of the power supply device. A main negative control module is installed on the main negative circuit. One end of the main negative control module is electrically connected to the negative terminal of the battery cluster, and the other end is electrically connected to the negative terminal of the power supply device. The charging and discharging control module and the main negative control module are configured to form one of the following circuits: a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit, and a discharging-to-charging circuit. The circuit can switch from the charging circuit to the discharging circuit after a transition through the charging-to-discharging circuit, or from the discharging circuit to the charging circuit after a transition through the discharging-to-charging circuit.

[0034] Specifically, the main positive circuit is connected between the positive terminal of the battery cluster and the power supply device, undertaking the main power transmission and integrating current detection, charge / discharge control, and protection functions. The main negative circuit is connected between the negative terminal of the battery cluster and the power supply device, serving as a common current return path and primarily responsible for the control and monitoring of the safe on / off switching of the entire charge / discharge circuit. The main negative circuit and the main positive circuit together form a complete current loop. In this embodiment, the battery cluster can store and release electrical energy; the power supply device is an uninterruptible power supply (UPS).

[0035] The charge / discharge control module is the core module of the charge / discharge circuit, integrating at least a charge control switch, a discharge control switch, and a current guiding unit. The charge and discharge control switches can be high-power DC contactors. The current guiding unit can be composed of power diodes, which utilize the unidirectional conductivity of the semiconductor PN junction to provide a unidirectional path for the current, effectively preventing reverse current flow. The charge / discharge control module can dynamically adjust the current path through the coordinated switching of its internal components.

[0036] In the main-negative circuit, the main-negative control module is responsible for controlling the circuit's on / off state. The main-negative control module contains at least one main-negative control switch. This main-negative control switch can be a high-power DC contactor.

[0037] The coordinated configuration of the charge / discharge control module and the main negative control module is essentially about controlling the state combination of the switching elements inside the charge / discharge control module and the main negative control module. By setting different switching state combinations, the current can be guided through different paths and elements, so that the main positive circuit and the main negative circuit together form five different functional circuits.

[0038] The charging and discharging circuit of this application utilizes the coordinated configuration of the charging and discharging control module and the main negative control module to enable the main positive circuit, main negative circuit, power supply equipment, and battery cluster to jointly form one of the following circuits: pre-charging circuit, charging circuit, charging-to-discharging circuit, discharging circuit, and discharging-to-charging circuit. It switches from the charging circuit to the discharging circuit via the charging-to-discharging circuit, or from the discharging circuit to the charging circuit via the discharging-to-charging circuit, allowing a single hardware circuit to be dynamically adjusted into different current paths, achieving seamless and rapid switching from the charging circuit to the discharging circuit. When the battery cluster needs to be discharged immediately after charging is completed, the charging and discharging circuit does not need to completely disconnect the main circuit and then re-energize it. Instead, the current flow direction can be instantly reversed through the state switching of the internal structures of the charging and discharging control module and the main negative control module. This eliminates the time delay caused by the complete opening and closing of relays in traditional charging and discharging circuits, thus meeting the requirement of uninterruptible power supply (UPS) equipment to provide truly uninterrupted power to critical loads such as data centers.

[0039] Please see Figure 1 The charging and discharging control module includes a first contactor KM1, a second contactor KM2, a first diode D1, a second diode D2, and a pre-charging unit. The first contactor KM1 and the second contactor KM2 are connected in series between the positive terminal of the battery pack and the power supply device, forming a series combination with a first node N1 and a second node N2. The current path from the second node N2 to the power supply device is shorter than that from the first node N1. The positive terminal of the first diode D1 is electrically connected to the first node N1, and the negative terminal of the first diode D1 is electrically connected to a third node N3 between the first contactor KM1 and the second contactor KM2. The positive terminal of the second diode D2 is electrically connected to the second node N2, and the negative terminal of the second diode D2 is electrically connected to the third node N3 between the first contactor KM1 and the second contactor KM2. The pre-charging unit is connected in parallel with the series combination.

[0040] The first contactor KM1 and the second contactor KM2 are high-power DC contactors. The first node N1 is located on the power supply side of the first contactor KM1, and the second node N2 is located on the load side of the second contactor KM2. The third node N3 is the connection point between the two contactor contacts.

[0041] The first diode D1 and the second diode D2 constitute an automatic current path selection and isolation unit. The cathodes of the first diode D1 and the second diode D2 are connected together at the third node N3. This connection method utilizes the unidirectional conductivity of the semiconductor PN junction to provide a natural, mechanically-free on / off logic for currents in different directions.

[0042] When current tends to flow from the first node N1 to the power supply device, the first diode D1 is forward biased and thus conducts; when current tends to flow from the power supply device to the second node N2, the second diode D2 becomes forward biased. The two diodes are electrically arranged in opposite directions, ensuring that only one path can be conducting at any given time, thus physically eliminating the possibility of a short circuit in the charging / discharging current path.

[0043] The pre-charge unit is connected in parallel with the above series combination. The pre-charge unit starts working when the charging and discharging circuit is started, and achieves a gradual voltage build-up by limiting the inrush current.

[0044] In the charging and discharging circuit of this application, the charging and discharging control module includes a first contactor KM1, a second contactor KM2, a first diode D1, a second diode D2, and a pre-charging unit. It utilizes the unidirectional conductivity of the diodes to achieve decoupling and automatic guidance of the charging and discharging current path, which not only provides a hardware foundation for rapid switching, but also effectively prevents the risk of current backflow or short circuit that may occur during the switching of charging and discharging states, ensuring the safety and reliability of the switching process.

[0045] Please see Figure 1 The pre-charging unit includes a third contactor KM3 connected in series and a pre-charging resistor R. One end of the third contactor KM3 is electrically connected to the first node N1, and one end of the pre-charging resistor R is electrically connected to the second node N2.

[0046] In the pre-charging unit, the third contactor KM3 is a medium-capacity DC contactor, whose contact current rating is typically lower than that of the first contactor KM1 and the second contactor KM2. The pre-charging resistor R is a current-limiting element with good impact resistance and thermal stability.

[0047] Please see Figure 2 When the charging and discharging circuit is activated, the third contactor KM3 closes first, and the current in the battery cluster forms a loop through the pre-charging resistor R. The pre-charging resistor R achieves smooth charging by limiting the inrush current within a safe range. As the capacitor voltage gradually rises, when the voltage difference between the pre-charging resistor R and the battery cluster voltage drops to a set threshold, it indicates that the pre-charging process is complete, and only then is the first contactor KM1 allowed to close.

[0048] In the charging and discharging circuit of this application, the pre-charging unit includes a third contactor KM3 connected in series and a pre-charging resistor R, providing a controlled, high-resistance pre-charging path, which can effectively limit the inrush current during startup, protect the relevant power devices at the downstream end, and improve the reliability and lifespan of the charging and discharging circuit.

[0049] Please see Figure 1 In some embodiments, a first current detection module is also provided on the main positive circuit. The first current detection module is used to detect the current on the main positive circuit. One end of the first current detection module is electrically connected to the positive electrode of the battery cluster, and the other end is electrically connected to the first node N1.

[0050] In the main positive circuit, the first current detection module is used to monitor the current value of the main positive circuit in real time. In some embodiments, the first current detection module can be a Hall current sensor. Hall current sensors are based on the Hall effect, calculating the current magnitude by detecting the magnetic field strength generated by the current. They have the advantage of electrical isolation from the circuit under test, improving monitoring safety and anti-interference capabilities. In other embodiments, the first current detection module can employ a structure of shunt resistor and isolation operational amplifier, obtaining the current value by measuring the voltage drop across a precision resistor.

[0051] Please refer to [link / reference] Figure 1 In some embodiments, a main positive fuse FU1 is also provided on the main positive circuit. One end of the main positive fuse FU1 is electrically connected to the first current detection module, and the other end is electrically connected to the first node N1.

[0052] The main positive fuse FU1 is connected in series between the positive terminal of the battery pack and the charge / discharge control module, forming an unavoidable overcurrent protection barrier. The rated current value of the main positive fuse FU1 is determined comprehensively based on the maximum continuous operating current of the charge / discharge circuit, the output capacity of the battery pack, and the withstand capability of subsequent wires and components, with a certain safety margin. When a severe overload or short-circuit fault occurs in the charge / discharge circuit, the fault current flowing through the main positive fuse FU1 will cause its internal special metal molten element to heat up and melt rapidly, thereby forcibly disconnecting the circuit within milliseconds.

[0053] Compared to the first circuit breaker QF1, the main positive fuse FU1 has a faster response speed and generally stronger breaking capacity, but its operation is a one-time protection and requires manual replacement after blowing. Therefore, the main positive fuse FU1 is mainly used to deal with extreme short circuit situations that the first circuit breaker QF1 cannot effectively break, and the two together form a hierarchical protection for the entire charging and discharging circuit.

[0054] In the charging and discharging circuit of this application, a main positive fuse is added to the main positive circuit. As an irreversible hardware protection barrier, the main positive fuse can quickly melt when the current increases abnormally, preventing the fault from spreading and protecting the battery pack and subsequent circuits.

[0055] Please continue reading. Figure 1 In some embodiments, the charging and discharging circuit further includes a first circuit breaker QF1. The first circuit breaker QF1 is the overall protection device for the current loop and has an overcurrent tripping function. The first circuit breaker QF1 has at least two polarities to simultaneously open and close the main positive and main negative circuits. Specifically, the positive terminal of the first circuit breaker QF1 is connected to the positive terminal of the power supply equipment and the return terminal of the main positive circuit, respectively, and the negative terminal of the first circuit breaker QF1 is connected to the negative terminal of the power supply equipment and the return terminal of the main negative circuit, respectively.

[0056] The main-negative control module includes a main-negative contactor KM4. A second current detection module is also installed on the main-negative circuit. This second current detection module detects the current in the main-negative circuit and is connected in series with the main-negative contactor KM4 between the negative terminal of the battery pack and the negative terminal of the power supply device. More specifically, the second current detection module is connected in series with the main-negative contactor KM4 between the negative terminal of the battery pack and the first circuit breaker QF1.

[0057] The first and second current detection modules together form a bidirectional current monitoring system. The first current detection module is connected in series at the positive terminal outlet of the battery cluster to accurately measure the total current flowing through the main positive circuit. The second current detection module is connected in series in the main negative circuit, and its measurement results can be cross-validated with the data from the first current detection module, improving the redundancy and reliability of current monitoring. The real-time current data provided by the first and second current detection modules is transmitted to the main control chip of the battery management module. This current data is used not only to calculate the charging and discharging capacity of the battery cluster but also to provide a basis for determining the contactor's operating timing.

[0058] As the core on / off control element in the main negative circuit, the main negative contactor KM4 is typically a high-power DC contactor of the same specifications as the main positive circuit contactor. The main negative contactor KM4 serves as the main switch for the charging and discharging circuit. Upon receiving an emergency fault signal or disconnection command, the main negative contactor KM4 will immediately activate, physically cutting off the current path of the entire current circuit.

[0059] The charging and discharging circuit of this application incorporates current detection modules (Hall sensors) in both the main positive and main negative circuits, enabling precise monitoring of the total charging and discharging current and providing crucial data for battery cluster management, state switching, and safety protection. Using the main negative contactor KM4 as the main switch ensures rapid and reliable disconnection of the entire charging and discharging circuit in emergencies, thus enhancing the safety of the charging and discharging circuit.

[0060] Please see Figure 1 The charging and discharging circuit has a pre-charging stage, a charging stage, a charging-to-discharging stage, a discharging stage, and a discharging-to-charging stage.

[0061] Please see Figure 2 During the pre-charging phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a pre-charging circuit.

[0062] Please see Figure 3 During the charging phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a charging circuit.

[0063] Please see Figure 4During the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a charging-to-discharging circuit.

[0064] Please see Figure 5 During the discharge phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a discharge circuit.

[0065] Please see Figure 6 During the discharge-to-charge phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment, thus forming a discharge-to-charge circuit.

[0066] During the pre-charging phase, the charging and discharging circuit limits the inrush current through the pre-charging resistor R, which enables smooth charging of the downstream components.

[0067] The charging phase begins after pre-charging is complete. At this time, the third contactor KM3 is open, and the first contactor KM1 and the second contactor KM2 are both closed, forming a low-impedance charging path. The current path in this phase is: UPS positive terminal → QF1 → KM2 → KM1 → main positive fuse FU1 (if set, otherwise directly to the first current detection module) → first current detection module → battery cluster positive terminal → battery cluster negative terminal → second current detection module → KM4 → QF1 → UPS negative terminal, as follows. Figure 3 The current path is shown in bold.

[0068] The charging-to-discharging phase is a critical transition period for mode switching. When an abnormal mains power is detected and immediate discharging is required, the battery management module (or system) first controls the power supply to stop output (or sends a charging-disable signal), reducing the charging current to zero. After confirming that the first current detection module detects zero current, the first contactor KM1 is disconnected, while the second contactor KM2 and the main negative contactor KM4 remain closed. At this time, due to the unidirectional conductivity of the second diode D2, the reverse flow of UPS-side voltage to the battery pack side through the second contactor KM2 is blocked.

[0069] Once the battery cluster has fully entered the discharge phase, the first contactor KM1 is closed again, forming a complete discharge circuit. At this time, the current flows from the positive terminal of the battery cluster through the first current detection module, the first contactor KM1, the second contactor KM2, and the first circuit breaker QF1 to the UPS equipment, supplying power to the load.

[0070] The discharge-to-charge phase is another crucial transition period for mode switching. When mains power is restored and recharging is required, the battery management module first sends a discharge-off signal to the power supply or controls the load to disconnect, reducing the discharge current to zero. After confirming that the first current detection module detects zero current, the second contactor KM2 is disconnected, while the third contactor KM3 remains open and the first contactor KM1 and the main negative contactor KM4 remain closed, utilizing the unidirectional conductivity of the first diode D1 to ensure electrical isolation. Subsequently, the BMS controls the second contactor KM2 to close again, completing the mode switch, i.e., forming a connection with... Figure 3 The complete charging circuit is shown.

[0071] The timing of each contactor's operation is precisely controlled by the battery management module, and its opening and closing interval is usually set in the range of 10-50 milliseconds to ensure that the current decays naturally within the mechanical action time.

[0072] In this embodiment, the coordinated operation of the first contactor KM1, the second contactor KM2, the third contactor KM3, the main negative contactor KM4, and the first circuit breaker QF1 enables the main positive circuit, the main negative circuit, the battery cluster, and the power supply equipment to jointly form one of the following circuits: a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit, and a discharging-to-charging circuit. This allows for switching between the pre-charging stage, the charging stage, the charging-to-discharging stage, the discharging stage, and the discharging-to-charging stage, thereby achieving a "seamless switching" between charging and discharging. In particular, the design of the two transition states, "charging-to-discharging stage" and "discharging-to-charging stage," provides precise control logic for the smooth and rapid (zero-delay) switching of charging and discharging modes, ensuring that path switching is completed under conditions of zero current or safety, and avoiding the impact on the equipment caused by sudden changes in voltage and current.

[0073] In some implementations, please refer to Figure 1 The battery cluster includes at least one battery pack, and the charging and discharging circuit also includes a battery management module. The battery management module includes a master control chip and at least one slave control chip. The first terminal of the master control chip is electrically connected to the first node N1, the second terminal of the master control chip is electrically connected to the second node N2, and the third terminal of the master control chip is electrically connected between the second current detection module and the main negative contactor KM4. Each battery pack is electrically connected to one slave control chip.

[0074] Specifically, a battery pack is an energy storage unit composed of multiple battery cells connected in series or parallel. In the charging and discharging circuit, the battery cluster acts as the energy carrier, providing DC power to the power supply equipment in the event of a mains power outage. The battery management module is a battery monitoring system consisting of a master control chip and at least one slave control chip. The battery management module is used to monitor the battery status (voltage, temperature, current) in real time, achieving balanced control and safety protection.

[0075] In some implementations, please refer to Figure 1 The charging and discharging circuit also includes a circuit breaker status detection circuit. One end of the circuit breaker status detection circuit is electrically connected to the fourth terminal of the main control chip, and the other end of the circuit breaker status detection circuit is electrically connected to the fifth terminal of the main control chip. The circuit breaker status detection circuit is used to detect the open and closed status of the first circuit breaker QF1.

[0076] Specifically, the circuit breaker status detection circuit is a low-power monitoring circuit connected between the fourth and fifth terminals of the main control chip. This circuit breaker status detection circuit is used to detect the mechanical switch contact status (closed / open) of the first circuit breaker QF1 in real time and feeds the signal back to the main control chip.

[0077] In some implementations, please refer to Figure 1 The charging and discharging circuit also includes a first power supply circuit and a second power supply circuit. The first power supply circuit is electrically connected to both the master control chip and the slave control chip and is used to supply power to both the master control chip and the slave control chip. The second power supply circuit is electrically connected to both the master control chip and the slave control chip and is used to supply power to both the master control chip and the slave control chip.

[0078] Specifically, the first power supply circuit is a DC power input circuit independent of the main charging and discharging circuit, directly connected to the power input pins of the master and slave control chips. The first power supply circuit provides the basic operating voltage (e.g., 5V / 3.3V) for all battery management chips (master and slave control chips), ensuring normal operation of data acquisition, communication, and logic control. The second power supply circuit is a backup DC power input circuit connected in parallel with the first power supply circuit, also connected to the power pins of the master and slave control chips.

[0079] In some implementations, please refer to Figure 1 The first power supply circuit includes a second circuit breaker QF2, an AC / DC power supply, and a third diode D3. The first terminal of the AC / DC power supply is electrically connected to the live wire via the second circuit breaker QF2, and the second terminal is electrically connected to the neutral wire. The anode of the third diode D3 is electrically connected to the third terminal of the AC / DC power supply, and the cathode of the third diode D3 is connected to the anodes of both the master control chip and the slave control chip. The fourth terminal of the AC / DC power supply is connected to the cathodes of both the master control chip and the slave control chip.

[0080] Specifically, the second circuit breaker QF2 is an overcurrent protection switch connected in series between the live wire and the first terminal of the AC / DC power supply. The second circuit breaker QF2 can control the AC input of the first power supply circuit, provide short-circuit or overload protection, and also serve as a maintenance isolation point to ensure safe maintenance during AC / DC power outages.

[0081] Specifically, an AC / DC power supply is a power conversion module that converts alternating current (live wire - neutral wire input) into direct current. An AC / DC power supply contains four functional terminals. The third diode, D3, is a unidirectional conducting device whose positive terminal is connected to the third terminal of the AC / DC power supply, and whose negative terminal is connected to the positive terminals of both the master and slave control chips. The third diode D3 prevents reverse voltage flow from the chip side into the AC / DC power supply, thus avoiding damage to the AC / DC power supply.

[0082] In some implementations, please refer to Figure 1 The second power supply circuit includes a third circuit breaker QF3, a DC / DC power supply, and a fourth diode D4. The first terminal of the DC / DC power supply is connected to the first node N1 via the third circuit breaker QF3, and the second terminal of the DC / DC power supply is connected to the negative terminal of the battery cluster via the third circuit breaker QF3. The positive terminal of the fourth diode D4 is electrically connected to the third terminal of the DC / DC power supply, and the negative terminal of the fourth diode D4 is electrically connected to the positive terminals of both the master control chip and the slave control chip. The fourth terminal of the DC / DC power supply is electrically connected to the negative terminals of both the master control chip and the slave control chip.

[0083] Specifically, the third circuit breaker QF3 is a double-ended protective switch connected in series between the battery pack output and the DC / DC power supply. Users can manually / automatically disconnect the input side of the second power supply circuit using the third circuit breaker QF3, safely isolating high voltage during maintenance. The DC / DC power supply is a power module that converts the high-voltage DC from the battery pack into low-voltage DC. The DC / DC power supply has four functional terminals. The fourth diode D4 is a unidirectional conducting device with its positive terminal connected to the third terminal of the DC / DC power supply and its negative terminal connected to the positive terminals of both the master and slave control chips. The fourth diode D4 prevents reverse current from flowing into the DC / DC power supply from the chip side, protecting the converter output stage.

[0084] Furthermore, by Figure 1 As can be seen on the left side, the charging and discharging circuit provided in this application is equipped with both AC / DC power supply to power the master control chip and slave control chip, and DC / DC power supply to power the master control chip and slave control chip.

[0085] In some implementations, please refer to Figure 1The cathodes of the third diode D3 and the fourth diode D4 are electrically connected, and the fourth terminal of the AC / DC power supply is electrically connected to the fourth terminal of the DC / DC power supply. The charging and discharging circuit also includes a spare connector, which has a positive and a negative terminal. The positive terminal of the spare connector is connected between the cathodes of the third diode D3 and the fourth diode D4, and the positive terminal of the spare connector is connected between the fourth terminal of the AC / DC power supply and the fourth terminal of the DC / DC power supply.

[0086] Specifically, the spare connector is the interconnection node connecting the negative terminals of the third diode D3 and the fourth diode D4. This spare connector provides a power source for external devices (such as maintenance instruments and extended sensors), outputting a stable low voltage from the same source as the BMS chip. When the main control chip fails, this external power supply can maintain the operation of the slave control chip.

[0087] In some implementations, please refer to Figure 1 The charging and discharging circuit also includes an indicator light. One end of the indicator light is connected between the negative terminal of the third diode D3 and the negative terminal of the fourth diode D4, and the other end is connected between the fourth terminal of the AC / DC power supply and the fourth terminal of the DC / DC power supply.

[0088] Specifically, the indicator light is a visual status indication device that is connected between the positive terminal of the power supply bus (D3 / D4 negative terminal interconnection point) and the common ground (AC / DC, DC / DC fourth terminal interconnection point).

[0089] The following describes the working process of the charging and discharging circuit of this application. Please refer to... Figures 2 to 6 , Figures 2 to 6 The direction of current flow is indicated by arrows. Figure 2 This is a schematic diagram of the current flow during the pre-charging phase of the battery cluster. Figure 2 The arrows and bold lines in the diagram indicate the direction of current flow, starting with... Figure 2 For example, after the charging and discharging circuit is powered on, the user manually closes the first circuit breaker QF1, the AC / DC power supply, the second circuit breaker QF2, the DC / DC power supply, and the third circuit breaker QF3, and the battery management module (BMS, i.e., Figure 2 The main control chip (in the circuit) is powered on and executes a self-test program. This self-test program typically checks for hardware faults and whether the sampled voltage and current values ​​are within appropriate ranges. After the self-test passes, the BMS first controls the closure of the main negative contactor KM4, connecting the battery pack (to...) Figure 2 The negative terminal of the slave control chip (connected in the circuit) is connected to the negative terminal of the mains power, establishing a complete potential reference for the subsequent circuit. Then, the third contactor KM3 is closed, at which point the positive terminal of the battery cluster is connected to the load capacitor (not shown in the diagram) through a pre-charge resistor. Current flows from... Figure 2The P+ input circuit flows sequentially through the pre-charge resistor R, the third contactor KM3, the main positive fuse FU1, the first current detection module, the battery pack, the second current detection module, and the main negative contactor KM4 to reach P-. At the instant the high-voltage system is powered on, if the battery pack is directly connected to the high-voltage mains power using the first contactor KM1, the second contactor KM2, and the main negative contactor KM4... Figure 2 A huge instantaneous current, or surge current, will be generated on P+ and P- in the battery pack. The current-limiting function of the pre-charge resistor prevents the surge current impact caused by directly connecting the battery pack to the high voltage. For example, the load capacitor is gradually charged to more than 95% of the total voltage of the battery pack. If the load voltage reaches the standard within 10 seconds, the BMS control automatically closes the second contactor KM2 and the first contactor KM1 to form a low-impedance main circuit, while simultaneously opening the third contactor KM3 to complete the smooth connection of the high-voltage system. If the pre-charge timeout or the voltage does not reach the threshold, the BMS determines it as a pre-charge fault, locks the contactor and triggers an alarm to prevent damage to the high-voltage box equipment.

[0090] Further, please refer to Figure 3 , Figure 3 This is a schematic diagram showing the current flow when the battery cluster completes the pre-charge stage and enters the charging stage. Figure 3 The arrows and bold lines indicate the direction of current flow. When the external charger is ready and there is no need for discharge, the first contactor KM1 remains closed, and the charging current flows through the second contactor KM2, the first contactor KM1, the main positive fuse FU1, the first current detection module, the battery cluster, the second current detection module, and the main negative contactor KM4. The two first current detection modules monitor the charging current in real time. In addition, if the battery cell voltage or temperature reaches the second-level alarm threshold during charging (e.g., battery cell voltage > 4.25V, or battery cell temperature > 50℃, indicating that the battery is fully charged or the battery temperature is too high, and the charging current needs to be disconnected), the BMS immediately sends a charging prohibition signal to the UPS equipment (the power supply / grid is connected to the P+ and P- terminals of the UPS equipment circuit to charge the battery cluster; the UPS equipment is also connected to the external load to provide power to the external load) to force the charger to stop outputting. After the first current detection module detects that the charging current has returned to zero, the BMS disconnects the first contactor KM1, physically isolating the charging circuit and avoiding the risk of floating high voltage.

[0091] Further, please refer to Figure 4 , Figure 4 This is a schematic diagram of the current flow during the battery cluster's transition from charging to discharging. Figure 4The arrows and bold lines indicate the direction of current flow. When the mains power is abnormally disconnected, to ensure that the external load connected to the UPS remains powered on, the battery pack automatically switches to discharge mode, supplying power to the external load through the UPS. The positive current from the battery pack flows through the first current detection module, the main positive fuse FU1, the reverse protection diode D1, and the second contactor KM2 to the positive terminal P+ of the UPS, then returns to the negative terminal P- via the load connected to the UPS, and finally flows through the main negative contactor KM4 and the second current detection module to the negative terminal of the battery pack. At this time, the second contactor KM2 is closed, while the first contactor KM1 remains open due to the charging prohibition signal. The current path consists of the first diode D1, the second contactor KM2, and the main negative contactor KM4. This allows the battery pack to supply power to the UPS while waiting for the first contactor KM1 to close, ensuring that the load connected to the UPS receives uninterrupted power. If charging needs to be resumed during the discharge process, for example, when the UPS equipment detects that the mains power has been restored, the BMS confirms the presence of discharge current (the load has not been disconnected) through the current detection module, and then removes the charging prohibition flag and closes the first contactor KM1. After the first contactor KM1 is closed, the charging current preferentially passes through the low-impedance first contactor KM1 circuit, and the first diode D1 is completely turned off due to reverse bias, realizing a rapid switching of the charging path.

[0092] Further, please refer to Figure 5 , Figure 5 This is a schematic diagram showing the current flow when the battery is fully discharged. Figure 5 The arrows and bold lines indicate the direction of current flow. In discharge mode, the discharge current of the battery cluster sequentially supplies power to the load through the first current detection module, the main positive fuse FU1, the first contactor KM1, and the second contactor KM2. The current then flows from the negative interface P- through the main negative contactor KM4 and the second current detection module to the negative terminal of the battery cluster. Both current detection modules continuously monitor the discharge current intensity. When the battery cell voltage or temperature reaches the lower limit of the secondary alarm (e.g., cell voltage < 2.8V), it indicates that the battery cluster's charge is too low. The BMS sends a discharge-prohibited signal to the UPS equipment, commanding the load to disconnect the power supply request. If the system needs to be completely stopped, the BMS waits until the two current detection modules report that the discharge current has dropped to zero before controlling the second contactor KM2 and the main negative contactor KM4 to disconnect, completely cutting off the discharge circuit. If the system needs to switch from discharge to charging, the BMS first checks the charger's ready status and, after the second contactor KM2 disconnects, re-establishes the charging path through a pre-charging process.

[0093] Further, please refer to Figure 6 , Figure 6 This is a schematic diagram of the current flow when a battery switches from the discharge stage to the charging stage; specifically, it is a schematic diagram of the current flow during the discharge to charge transition. Figure 6 The arrows and bold lines indicate the direction of current flow. If an emergency charging demand is encountered during the discharge process, the system first enters the discharge-to-charge phase (i.e., the load is stopped, the current crosses zero, and the second contactor KM2 is disconnected). At this time, the current enters from the positive terminal P+ of the mains power, flows sequentially through the second diode D2, the first contactor KM1, the main positive fuse FU1, the first current detection module, and finally to the positive terminal of the battery cluster, thus achieving charging. The second diode D2 enables the battery cluster to start charging immediately after the second contactor KM2 is disconnected and before it is re-closed.

[0094] In summary, the charging and discharging circuit of this application includes a main positive circuit and a main negative circuit. One end of the main positive circuit is electrically connected to the positive terminal of the battery pack, and the other end is electrically connected to the power supply device through the first circuit breaker QF1. The main positive circuit is equipped with a first current detection module, a main positive fuse FU1, a first contactor KM1, a second contactor KM2, a third contactor KM3, a pre-charge resistor R, a first diode D1, and a second diode D2. The first current detection module, the main positive fuse, the first contactor KM1, and the second contactor KM2 are connected in series between the positive terminal of the battery pack and the first circuit breaker QF1. The third contactor KM3 and the pre-charge resistor R are connected in series and then in parallel across the two ends of the first contactor KM1 and the second contactor KM2. The positive terminal of the first diode D1 is electrically connected between the main positive fuse FU1 and the first contactor KM1, and the negative terminal of the first diode D1 is electrically connected between the first contactor KM1 and the second contactor KM2. The positive terminal of the second diode D2 is electrically connected between the second contactor KM2 and the first circuit breaker QF1, and the negative terminal of the second diode D2 is electrically connected between the first contactor KM1 and the second contactor KM2. One end of the main negative circuit is electrically connected to the negative terminal of the battery pack, and the other end is electrically connected to the power supply equipment through the first circuit breaker QF1. The main negative circuit includes a second current detection module and a main negative contactor KM4, which are connected in series between the negative terminal of the battery pack and the first circuit breaker QF1. When the battery cluster switches between charging and discharging states, if the first contactor KM1 or the second contactor KM2 cannot switch in time, the charging and discharging circuit of this application can allow the current to flow through the first diode D1 or the second diode D2, so that the battery cluster can discharge immediately after charging is cut off, thus meeting the power supply needs of load equipment such as data centers that cannot be powered off.

[0095] Please see Figure 7 The present application also provides a high-voltage box, which includes the charging and discharging circuit described in any of the above embodiments.

[0096] Please see Figure 8The present application also provides an energy storage system, which includes a battery cluster, a power supply device, and a charging and discharging circuit of any of the above embodiments. The high-voltage box is electrically connected to both the battery cluster and the power supply device.

[0097] This application also provides a control method for a charging and discharging circuit. The control method is applicable to the charging and discharging circuit described in any of the above embodiments, and the control method includes: By utilizing the cooperation between the charge / discharge control module and the main negative control module, the main positive circuit, the main negative circuit, the battery cluster, and the power supply equipment can switch between the pre-charge circuit, the charging circuit, the charging-to-discharge circuit, the discharging circuit, and the discharging-to-charge circuit.

[0098] More specifically, during the pre-charging phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment, so as to form a pre-charging circuit. During the charging phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a charging circuit. During the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are open, and the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a charging-to-discharging circuit. During the discharge phase, the main negative contactor KM4, the first contactor KM1, and the second contactor KM2 are closed, the third contactor KM3 is open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment to form a discharge circuit. During the discharge-to-charge phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are open, the first circuit breaker QF1 connects the second node N2 to the positive terminal of the power supply equipment, and connects the main negative contactor KM4 to the negative terminal of the power supply equipment, thus forming a discharge-to-charge circuit.

[0099] In some embodiments, the battery cluster includes at least one, the charging and discharging circuit further includes a battery management module, and the control method further includes: When the battery pack is fully charged, the battery management module sends a charge-disable signal to the power supply device; When the mains power is disconnected, the battery pack switches from the charging stage to the discharging stage and then to the discharging stage. When the current obtained by the first current detection module is zero, the first contactor KM1 is disconnected until the current obtained by the first current detection module is not zero. If the current obtained by the first current detection module is not zero, the battery cluster enters the discharge stage, controls the first contactor KM1 to close, and controls the second contactor KM2 and the main negative contactor KM4 to remain closed.

[0100] In some implementations, the control method further includes: When the battery cluster is depleted, the battery management module sends a kill signal to the power supply device; After the battery cluster transitions from the discharge stage to the charging stage, it switches to the charging stage. If the current obtained by the first current detection module is zero, the second contactor KM2 is disconnected until the current obtained by the first current detection module is not zero. If the current detected by the first current detection module is not zero, the battery cluster enters the charging stage, controls the second contactor KM2 to close, and controls the main negative contactor KM4 and the first contactor KM1 to remain closed.

[0101] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. At the same time, other implementation methods can be derived from the above embodiments, so that structural and logical substitutions and changes can be made without departing from the scope of this disclosure.

[0102] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A charge-discharge circuit characterized by comprising: include: A main positive circuit, wherein a charge / discharge control module is provided on the main positive circuit, one end of the charge / discharge control module is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the positive terminal of the power supply device; and A main negative circuit is provided, and a main negative control module is provided on the main negative circuit. One end of the main negative control module is used to be electrically connected to the negative terminal of the battery cluster, and the other end is used to be electrically connected to the negative terminal of the power supply device. The charging and discharging control module and the main negative control module are configured to make the main positive circuit, the main negative circuit, the battery cluster and the power supply device jointly form one of a pre-charging circuit, a charging circuit, a charging-to-discharging circuit, a discharging circuit and a discharging-to-charging circuit. The circuit can switch from the charging circuit to the discharging circuit after transitioning through the charging-to-discharging circuit, or switch from the discharging circuit to the charging circuit after transitioning through the discharging-to-charging circuit.

2. The charge and discharge circuit according to claim 1, characterized by, The charge / discharge control module includes: First contactor KM1; The second contactor KM2 is connected in series with the first contactor KM1 between the positive terminal of the battery pack and the power supply device, forming a series combination with a first node N1 and a second node N2, wherein the current path from the second node N2 to the power supply device is shorter than that from the first node N1. The first diode D1, the positive terminal of the first diode D1 is electrically connected to the first node N1, and the negative terminal of the first diode D1 is electrically connected to the third node N3 between the first contactor KM1 and the second contactor KM2. The second diode D2, with its positive terminal electrically connected to the second node N2 and its negative terminal electrically connected to the third node N3; and The pre-charge unit is connected in parallel with the series combination.

3. The charge and discharge circuit according to claim 2, wherein The pre-charging unit includes: A third contactor KM3 and a pre-charge resistor R are connected in series. One end of the third contactor KM3 is electrically connected to the first node N1, and one end of the pre-charge resistor R is electrically connected to the second node N2.

4. The charge and discharge circuit according to claim 3, wherein The main positive circuit is also equipped with: The first current detection module is used to detect the current in the main positive circuit. One end of the first current detection module is electrically connected to the positive terminal of the battery cluster, and the other end is electrically connected to the first node N1.

5. The charge and discharge circuit according to claim 4, wherein The main positive circuit is also equipped with: The main positive fuse has one end electrically connected to the first current detection module and the other end electrically connected to the first node N1.

6. The charge and discharge circuit according to claim 4, wherein The main negative control module includes a main negative contactor KM4. A second current detection module is also provided on the main negative circuit. The second current detection module is used to detect the current on the main negative circuit. The second current detection module and the main negative contactor KM4 are connected in series between the negative terminal of the battery pack and the negative terminal of the power supply device. The charging and discharging circuit also includes a first circuit breaker QF1, which is connected in series between the power supply device and the second node N2 to switch the main positive circuit; the first circuit breaker QF1 is also connected in series between the power supply device and the main negative contactor KM4 to switch the main negative circuit.

7. The charge and discharge circuit according to claim 6, wherein The charging and discharging circuit has a pre-charging phase, a charging phase, a charging-to-discharging phase, a discharging phase and a discharging-to-charging phase. In the pre-charging phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are opened, the first breaker QF1 connects the second node N2 with the positive pole of the power supply device and connects the main negative contactor KM4 with the negative pole of the power supply device to form the pre-charging loop. In the charging phase, the main negative contactor KM4, the first contactor KM1 and the second contactor KM2 are closed, the third contactor KM3 is opened, the first breaker QF1 connects the second node N2 with the positive pole of the power supply device and connects the main negative contactor KM4 with the negative pole of the power supply device to form the charging loop. In the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are opened, the first breaker QF1 connects the second node N2 with the positive pole of the power supply device and connects the main negative contactor KM4 with the negative pole of the power supply device to form the charging-to-discharging loop. In the discharging phase, the main negative contactor KM4, the first contactor KM1 and the second contactor KM2 are closed, the third contactor KM3 is opened, the first breaker QF1 connects the second node N2 with the positive pole of the power supply device and connects the main negative contactor KM4 with the negative pole of the power supply device to form the discharging loop. In the discharging-to-charging phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are opened, the first breaker QF1 connects the second node N2 with the positive pole of the power supply device and connects the main negative contactor KM4 with the negative pole of the power supply device to form the discharging-to-charging loop.

8. The charge and discharge circuit according to claim 6, characterized by, The battery cluster includes at least one battery pack, and the charging and discharging circuit further includes a battery management module, which includes: a master control chip, a first end of the master control chip being electrically connected to the first node N1, a second end of the master control chip being electrically connected to the second node N2, and a third end of the master control chip being electrically connected between the second current detection module and the main negative contactor KM4; and at least one slave control chip, one slave control chip being electrically connected to each battery pack.

9. The charge and discharge circuit according to claim 8, wherein Further including: an air-break state detection loop, one end of the air-break state detection loop being electrically connected to a fourth end of the master control chip, and the other end of the air-break state detection loop being electrically connected to a fifth end of the master control chip, the air-break state detection loop being used for detecting the on-off state of the first breaker QF1.

10. The charge and discharge circuit according to claim 8, characterized by, Further including: a first power supply loop, which is electrically connected to the master control chip and the slave control chip and is used for supplying power to the master control chip and the slave control chip; and ​ A second power supply circuit is electrically connected with the master chip and the slave chip, and is used for supplying power to the master chip and the slave chip.

11. The charge and discharge circuit according to claim 10, wherein The first power supply circuit comprises: A second breaker QF2; An AC / DC power supply, a first end of the AC / DC power supply is electrically connected with a live wire through the second breaker QF2, and a second end of the AC / DC power supply is electrically connected with a zero line; A third diode D3, a positive electrode of the third diode D3 is electrically connected with a third end of the AC / DC power supply, and a negative electrode of the third diode D3 is electrically connected with a positive electrode of the master chip and a positive electrode of the slave chip, and a fourth end of the AC / DC power supply is electrically connected with a negative electrode of the master chip and a negative electrode of the slave chip.

12. The charge and discharge circuit according to claim 11, wherein The second power supply circuit comprises: A third breaker QF3; A DC / DC power supply, a first end of the DC / DC power supply is electrically connected with the first node N1 through the third breaker QF3, and a second end of the DC / DC power supply is electrically connected with a negative electrode of the battery cluster through the third breaker QF3; A fourth diode D4, a positive electrode of the fourth diode D4 is electrically connected with a third end of the DC / DC power supply, and a negative electrode of the fourth diode D4 is electrically connected with a positive electrode of the master chip and a positive electrode of the slave chip, and a fourth end of the DC / DC power supply is electrically connected with a negative electrode of the master chip and a negative electrode of the slave chip.

13. The charge and discharge circuit according to claim 12, wherein The negative electrode of the third diode D3 and the negative electrode of the fourth diode D4 are electrically connected, and the fourth end of the AC / DC power supply and the fourth end of the DC / DC power supply are electrically connected; the charge and discharge circuit further comprises: A backup joint comprising a positive electrode and a negative electrode, the positive electrode of the backup joint is electrically connected between the negative electrode of the third diode D3 and the negative electrode of the fourth diode D4, and the negative electrode of the backup joint is electrically connected between the fourth end of the AC / DC power supply and the fourth end of the DC / DC power supply.

14. The charge and discharge circuit according to claim 12, wherein Further comprising: An indicator light, one end of the indicator light is connected between the negative electrode of the third diode D3 and the negative electrode of the fourth diode D4, and the other end of the indicator light is connected between the fourth end of the AC / DC power supply and the fourth end of the DC / DC power supply.

15. A high pressure tank characterized by, Comprise: The charge and discharge circuit of any one of claims 1-14.

16. An energy storage system characterized by, Comprise: A battery cluster; A power supply device; And The high-voltage box of claim 15, the high-voltage box is electrically connected with the battery cluster and the power supply device.

17. A control method of a charge-discharge circuit, characterized by, The charge and discharge circuit comprises: A main positive circuit, a charge and discharge control module is arranged on the main positive circuit, one end of the charge and discharge control module is used for being electrically connected with a positive electrode of a battery cluster, and the other end of the charge and discharge control module is used for being electrically connected with a positive electrode of a power supply device; and A main negative circuit, a main negative control module is arranged on the main negative circuit, one end of the main negative control module is used for being electrically connected with a negative electrode of the battery cluster, and the other end of the main negative control module is used for being electrically connected with a negative electrode of the power supply device. The control method comprises: by cooperation of the charge-discharge control module and the main negative control module, the main positive loop, the main negative loop, the battery cluster and the power supply device are switched in a pre-charge loop, a charge loop, a charge-to-discharge loop, a discharge loop and a discharge-to-charge loop.

18. The control method according to claim 17, characterized by The charge-discharge circuit further comprises a first circuit breaker QF1, positive passage terminals of the first circuit breaker QF1 are connected to a positive electrode of the power supply device and a return end of the main positive loop respectively, negative passage terminals of the first circuit breaker QF1 are connected to a negative electrode of the power supply device and a return end of the main negative loop respectively; the charge-discharge control module comprises a first contactor KM1, a second contactor KM2, a first diode D1 and a second diode D2, the second contactor KM2 and the first contactor KM1 are connected in series between the positive electrode of the battery cluster and the power supply device, and form a series combination with a first node N1 and a second node N2, the second node N2 is shorter than the first node N1 in the current path to the power supply device; a positive electrode of the first diode D1 is electrically connected to the first node N1, a negative electrode of the first diode D1 is electrically connected to a third node N3 between the first contactor KM1 and the second contactor KM2; a positive electrode of the second diode D2 is electrically connected to the second node N2, a negative electrode of the second diode D2 is electrically connected to the third node N3; the pre-charge unit comprises a third contactor KM3 and a pre-charge resistor R connected in series, one end of the third contactor KM3 is electrically connected to the first node N1, one end of the pre-charge resistor R is electrically connected to the second node N2, the main positive loop further comprises a first current detection module, one end of the first current detection module is electrically connected to the positive electrode of the battery cluster, and the other end is electrically connected to the first node N1, the main negative loop further comprises a second current detection module, the main negative control module comprises a main negative contactor KM4, the second current detection module and the main negative contactor KM4 are connected in series between the negative electrode of the battery cluster and the first circuit breaker QF1; The charge-discharge circuit has a pre-charge phase, a charge phase, a charge-to-discharge phase, a discharge phase and a discharge-to-charge phase; The control method further comprises: In the pre-charge phase, the main negative contactor KM4 and the third contactor KM3 are closed, the first contactor KM1 and the second contactor KM2 are disconnected, and the first circuit breaker QF1 conducts the second node N2 and the positive electrode of the power supply device, and conducts the main negative contactor KM4 and the negative electrode of the power supply device, to form the pre-charge loop; In the charge phase, the main negative contactor KM4, the first contactor KM1 and the second contactor KM2 are closed, the third contactor KM3 is disconnected, the first circuit breaker QF1 conducts the second node N2 and the positive electrode of the power supply device, and conducts the main negative contactor KM4 and the negative electrode of the power supply device, to form the charge loop; In the discharge phase, the main negative contactor KM4, the first contactor KM1 and the second contactor KM2 are disconnected, the third contactor KM3 is closed, and the first circuit breaker QF1 conducts the second node N2 and the positive electrode of the power supply device, and conducts the main negative contactor KM4 and the negative electrode of the power supply device, to form the discharge loop; In the charging-to-discharging phase, the main negative contactor KM4 and the second contactor KM2 are closed, the first contactor KM1 and the third contactor KM3 are opened, the first breaker QF1 connects the second node N2 to the positive pole of the power supply device and the negative pole of the power supply device to the main negative contactor KM4 to form the charging-to-discharging loop; In the discharging phase, the main negative contactor KM4, the first contactor KM1 and the second contactor KM2 are closed, the third contactor KM3 is opened, the first breaker QF1 connects the second node N2 to the positive pole of the power supply device and the negative pole of the power supply device to the main negative contactor KM4 to form the discharging loop; In the discharging-to-charging phase, the main negative contactor KM4 and the first contactor KM1 are closed, the second contactor KM2 and the third contactor KM3 are opened, the first breaker QF1 connects the second node N2 to the positive pole of the power supply device and the negative pole of the power supply device to the main negative contactor KM4 to form the discharging-to-charging loop.

19. The control method according to claim 18, characterized by, The charging and discharging circuit further comprises a battery management module, and the control method further comprises: When the battery cluster is fully charged, the battery management module sends a charging prohibition signal to the power supply device; When the mains power is disconnected, the battery cluster switches from the charging phase to the discharging phase through the charging-to-discharging phase, and when the current obtained by the first current detection module is zero, the first contactor KM1 is opened until the current obtained by the first current detection module is not zero; When the current obtained by the first current detection module is not zero, the battery cluster enters the discharging phase, the first contactor KM1 is controlled to be closed, and the second contactor KM2 and the main negative contactor KM4 are controlled to remain closed.

20. The control method according to claim 18, wherein The charging and discharging circuit further comprises a battery management module, and the control method further comprises: When the battery cluster is fully charged, the battery management module sends a charging prohibition signal to the power supply device; When the mains power is disconnected, the battery cluster switches from the charging phase to the discharging phase through the charging-to-discharging phase, and when the current obtained by the first current detection module is zero, the first contactor KM1 is opened until the current obtained by the first current detection module is not zero; When the current obtained by the first current detection module is not zero, the battery cluster enters the discharging phase, the first contactor KM1 is controlled to be closed, and the second contactor KM2 and the main negative contactor KM4 are controlled to remain closed.

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