Power supply connecting device, power utilization device and related system

Abstract

The embodiment of the utility model provides a power supply connecting device, a power utilization device and a related system. The power supply connecting device comprises a first branch circuit and a second branch circuit, the first branch comprises a first switch and a first resistor, two ends of the first switch are respectively connected to the anode of the battery device and the first end of the first resistor, and the second end of the first resistor is connected to the anode of the converter; the second branch comprises a second switch and a power supply which are connected in series; two ends of the second branch are respectively connected to the first end of the first resistor and the cathode of the converter. When the converter needs to be powered on, the second switch is closed firstly, so that a direct-current side capacitor of the converter is charged through the power supply; if the direct-current side voltage of the converter does not rise to the first voltage threshold value within the first preset duration, it is indicated that a short-circuit fault exists; if there is no short-circuit fault, the first switch is closed, the second switch is opened, charging is continued through the battery device, damage of the short-circuit fault to equipment such as the battery device is avoided, and the maintenance cost is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a power supply connection device, power consumption device and related system. Background Technology

[0002] With the development of new energy technologies, rechargeable battery systems are widely used in power systems, energy storage systems, electric vehicles, and many other fields. A converter is typically installed between the battery system and the connected power grid or load to convert electrical energy between the battery system and the grid or load, ensuring that the electrical energy output from the battery system meets the load's power demand, or that the electrical energy provided by the grid meets the battery system's charging needs.

[0003] In related technologies, DC power-on protection between the battery system and the inverter is typically achieved using only fuses. However, during power-on, if a short circuit fault occurs on the DC line between the battery system and the inverter, while the fuse can provide some protection by blowing, the blowing of the fuse requires certain conditions. During this process, it may also cause some damage to the battery system or related equipment, or even lead to serious consequences such as fire. Furthermore, after the fuse blows, maintenance personnel need to replace it, increasing the workload and cost of maintenance.

[0004] Therefore, how to proactively identify short-circuit faults on external circuits of the battery system in advance, improve the safety of the battery system and related electrical equipment, and reduce maintenance costs has become a technical problem that urgently needs to be solved in this field.

[0005] The above statements are for the purpose of providing background information in relation to this application only and do not necessarily constitute prior art. Utility Model Content

[0006] In view of the above problems, embodiments of this application provide a power supply connection device, an electrical device, and a related system.

[0007] In a first aspect, embodiments of this application provide a power supply connection device for controlling the connection and disconnection between a battery device and an inverter. The power supply connection device includes a first branch and a second branch. The first branch includes a first switch and a first resistor, with the two ends of the first switch connected to the positive terminal of the battery device and the first terminal of the first resistor, respectively. The second terminal of the first resistor is connected to the positive terminal of the inverter. The second branch includes a second switch and a power supply connected in series, with the two ends of the second branch connected to the first terminal of the first resistor and the negative terminal of the inverter, respectively. A DC-side capacitor is connected between the positive and negative terminals of the inverter. The output voltage of the power supply is related to the resistance value of the first resistor and the maximum current that the second switch can withstand, and the output voltage of the power supply is less than the output voltage of the battery device.

[0008] The aforementioned power supply connection device allows the power supply to charge the DC-side capacitor of the converter through the first resistor when the second switch is closed and the first switch is open. When the second switch is open and the first switch is closed, the battery device can charge the DC-side capacitor of the converter through the first resistor.

[0009] In the above embodiments, a first branch and a second branch are respectively provided in the power supply connection device. These two branches can charge the DC-side capacitor of the converter to ensure that the DC-side voltage of the converter meets its normal operating requirements, thus enabling the converter to power on. Based on this, when the converter needs to be powered on, the second switch can be closed and the first switch opened first to charge the DC-side capacitor of the converter through the power supply in the second branch. If there are no abnormalities in the charging through the second branch, the first switch can be closed and the second switch opened to continue charging the DC-side capacitor of the converter through the battery device until the normal operating requirements of the converter are met. Therefore, the above embodiments avoid directly charging the DC-side capacitor of the converter through the battery device, thus avoiding potential short-circuit faults on the DC side of the converter that could damage the battery device and related equipment. Furthermore, even when there are no short-circuit faults on the DC side of the converter, the charging process of its DC-side capacitor can be completed, enabling the converter to power on and operate normally.

[0010] Furthermore, based on the aforementioned power supply connection device, the charging process of the DC-side capacitor of the converter can be utilized through the power supply in the second branch to achieve active identification of short-circuit faults. That is, if the DC-side voltage can rise normally through the power supply in the second branch, it indicates that there is no short-circuit fault on the DC side of the converter; otherwise, it indicates that a short-circuit fault exists. Therefore, the power supply connection device provided in the above embodiment can not only complete the DC-side charging process of the converter normally when there is no short-circuit fault, but also promptly identify short-circuit faults, disconnect the charging circuit, and ensure that related equipment is not damaged due to short-circuit faults, thereby improving the safety of related equipment and systems and reducing maintenance costs.

[0011] In some optional embodiments, the power supply connection device further includes a third switch. The two ends of the third switch are respectively connected to the first end of the first resistor and the negative terminal of the converter. After the converter is powered off, the third switch closes to discharge the converter through the first resistor.

[0012] In the above embodiments, by setting a third switch in the power supply connection device, when the converter is powered off, both the first and second switches are disconnected, thereby disconnecting the battery device from the DC side of the converter. At this time, by closing the third switch, a discharge circuit is formed between the first resistor in the first branch and the DC side capacitor of the converter. The electrical energy stored in the DC side capacitor of the converter is quickly released by the first resistor, reducing the risk of electric shock to relevant personnel and reducing the difficulty of inspection and maintenance of the converter.

[0013] In some optional embodiments, the power supply connection device further includes a fourth switch. The two ends of the fourth switch are connected to the positive terminal of the battery and the positive terminal of the inverter, respectively. After the DC-side capacitor of the inverter is charged by the battery, the fourth switch is closed first, and then the first switch is opened, so that the positive terminal of the battery is directly connected to the positive terminal of the inverter. When the inverter needs to be powered down, the fourth switch is opened.

[0014] In the above embodiments, the fourth switch can be used as the main control switch on the positive line of the battery device. After the DC side capacitor of the inverter is charged, the first resistor can be short-circuited by closing the fourth switch. The first switch can also be further opened so that the battery device and the inverter can be directly connected without passing through the first resistor, thereby reducing the power consumption of the corresponding system during normal operation and improving the power utilization rate of the system.

[0015] In some optional embodiments, the power supply connection device further includes a fifth switch. The two ends of the fifth switch are connected to the negative terminal of the battery and the negative terminal of the inverter, respectively. The fifth switch is closed when at least one of the first and fourth switches is closed. The fifth switch is open when the inverter needs to be powered down.

[0016] In the above embodiments, the fifth switch can be used as the main control switch on the negative terminal line of the battery device. By disconnecting the fifth switch, multiple circuits related to the battery device can be quickly disconnected, thereby improving the power outage response efficiency and enhancing the safety of the related system.

[0017] In some optional embodiments, the power supply includes at least one of a DC voltage source, a switching power supply, a linear power supply, and a battery;

[0018] The first switch mentioned above includes at least one of a contactor, a relay, and a power switching transistor; the second switch mentioned above includes at least one of a contactor, a relay, and a power switching transistor.

[0019] In the above embodiments, the power supply, first switch, and second switch in the power supply connection device can be of multiple types to adapt to different application scenarios.

[0020] In some optional embodiments, the second switch is closed when the converter needs to be powered on, so that the power supply in the second branch can charge the DC-side capacitor of the converter in the first stage; the second switch is opened when the duration of the first stage charging is not less than a first preset duration and the target voltage is less than a first voltage threshold, so as to stop the first stage charging, wherein the target voltage is the voltage between the positive and negative terminals of the converter, that is, the voltage across the DC-side capacitor of the converter.

[0021] In the above embodiments, when the converter needs to be powered on, the second switch is closed first instead of the first switch. This allows the DC-side capacitor of the converter to be charged in the first stage through the power supply in the second branch, avoiding the direct connection of the battery device to the converter caused by directly closing the first switch. This can prevent short circuit faults on the DC side of the converter from damaging the battery device, improve the safety of related equipment and systems, and reduce maintenance costs.

[0022] Secondly, based on the power supply connection device provided in the above embodiment, during the process of closing the second switch and charging the DC side capacitor of the converter in the first stage through the voltage in the second branch, the change of the voltage across the DC side capacitor, i.e. the target voltage, can be used to identify whether there is a short circuit fault on the DC side of the converter.

[0023] That is, if the target voltage still has not reached the first voltage threshold when the duration of the first stage charging reaches the first preset duration, it indicates that there is a short circuit fault on the DC side of the converter. At this time, the second switch can be disconnected to stop the first stage charging so that relevant personnel can carry out maintenance. If the target voltage can reach the first voltage threshold, it indicates that there is no short circuit fault on the DC side of the converter. At this time, the second switch can be disconnected and the first switch closed, so that the DC side capacitor of the converter can continue to be charged in the second stage through the battery device until the normal operation requirements of the converter are met. Therefore, based on the power supply connection device provided in the above embodiment, it is possible to identify whether there is a short circuit fault on the DC side of the converter, thereby improving the safety of related equipment and systems and reducing maintenance costs.

[0024] In some optional embodiments, during the first stage of charging the DC-side capacitor of the converter via the power supply, when the target voltage reaches a first voltage threshold, the second switch is opened and the first switch is closed to perform a second stage of charging the DC-side capacitor of the converter via the battery device.

[0025] In the above embodiments, during the first-stage charging of the DC-side capacitor of the converter via the power supply, if the DC-side voltage of the converter, i.e., the target voltage, reaches the first voltage threshold, it indicates that there is no short-circuit fault on the DC side of the converter. Therefore, the first switch can be closed and the second switch opened to connect the battery device to the converter, thereby continuing to charge the DC-side capacitor of the converter through the battery device until the DC-side voltage meets the normal operating requirements of the converter. Therefore, the power supply connection device provided in the above embodiments can both identify whether there is a short-circuit fault on the DC side of the converter, preventing damage to related equipment or systems, and can also complete the charging of the DC-side capacitor of the converter normally in the absence of a short-circuit fault, meeting the normal operating requirements of the converter.

[0026] In some alternative embodiments, when a fourth switch is connected in series between the positive terminal of the battery device and the positive terminal of the inverter, during the second stage of charging of the inverter by the battery device, the fourth switch closes when the target voltage reaches a second voltage threshold, wherein the second voltage threshold is greater than the first voltage threshold.

[0027] In the above embodiments, when the target voltage rises to the second voltage threshold, it indicates that the DC-side capacitor of the converter has been fully charged, which means that the normal operation requirements of the converter have been met. Therefore, by closing the fourth switch and short-circuiting the first resistor, the positive terminal of the battery device can be directly connected to the positive terminal of the converter, thereby reducing the power consumption of the corresponding system during normal operation and improving the power utilization rate of the system.

[0028] Secondly, embodiments of this application provide a power supply connection device for controlling the connection and disconnection between a battery device and an inverter. The power supply connection device includes a first branch and a second branch. The first branch includes a first switch and a first resistor connected in series, with its two ends connected to the positive terminal of the battery device and the positive terminal of the inverter, respectively. The second branch includes a second switch, a power supply, and a second resistor connected in series, with its two ends connected to the positive and negative terminals of the inverter, respectively. A DC-side capacitor is connected between the positive and negative terminals of the inverter. The output voltage of the power supply is related to the resistance value of the second resistor and the maximum current that the second switch can withstand, and the output voltage of the power supply is less than the output voltage of the battery device.

[0029] In the aforementioned power supply connection device, when the second switch is closed and the first switch is open, the power supply charges the DC-side capacitor of the converter through the second resistor; when the second switch is open and the first switch is closed, the battery device charges the DC-side capacitor of the converter through the first resistor.

[0030] Thirdly, embodiments of this application provide a battery management system, including: the power supply connection device described in the first or second aspect; the battery management system is used to control the charging and discharging of the battery device to external devices.

[0031] Fourthly, embodiments of this application provide a battery system, including: a battery device and the battery management system described in the third aspect.

[0032] Fifthly, embodiments of this application provide an electrical device, including: an electrical load, a converter, and the battery system described in the fourth aspect, wherein the battery system is used to supply power to the electrical load via the converter.

[0033] In a sixth aspect, embodiments of this application provide an energy conversion system, including: a converter and a power supply connection device connected to the converter; the power supply connection device is the power supply connection device described in the first or second aspect, and the power supply connection device is also connected to a battery device outside the energy conversion system for controlling the connection and disconnection between the converter and the battery device; the converter is also connected to external equipment such as a load or a power grid system for realizing the conversion of electrical energy between the battery device and the external equipment.

[0034] In a seventh aspect, embodiments of this application provide an energy storage system, which includes: a battery device, a power supply connection device, and a converter; the power supply connection device is connected to the battery device and the converter respectively, and is used to control the connection and disconnection between the battery device and the converter; the power supply connection device is the power supply connection device described in the first aspect or the second aspect; the converter is used to realize the conversion of electrical energy between the battery device and external devices of the energy storage system.

[0035] The battery management system, battery system, power device, energy conversion system, energy storage system, etc. provided in the above embodiments, by configuring the power supply connection device described in the first or second aspect, can identify short circuit faults, charging abnormalities, etc. that may exist during the power-on process, and quickly release the electrical energy stored in the relevant equipment when the power is off, under the premise of ensuring that the relevant system can be powered on and off normally, thereby improving the safety of the relevant system and reducing maintenance costs.

[0036] In the technical solutions provided in this application, when the converter needs to be powered on, short-circuit fault identification can be achieved through the second branch of the power supply connection device without connecting it to the battery device, preventing damage to the converter, battery device, and related systems due to short-circuit faults. If no short-circuit fault is identified, the first branch of the power supply connection device can be used to connect the battery device to the converter, completing the power supply to the converter and enabling the related systems to operate normally. Furthermore, after the converter is powered off, the discharge branch of the power supply connection device can be used to discharge the DC-side capacitor of the converter, quickly reducing its DC-side bus voltage and avoiding the risk of electric shock and maintenance difficulties. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an architectural diagram illustrating an application scenario based on one or more embodiments;

[0039] Figure 2 This is a structural block diagram of a power supply connection device for power-on control of a converter according to one or more embodiments;

[0040] Figure 3 This is a structural block diagram of another power supply connection device for implementing power-on control and discharge control of a converter, according to one or more embodiments.

[0041] Figure 4 This is a structural block diagram of another power supply connection device for implementing power-on control and discharge control of a converter, according to one or more embodiments.

[0042] Figure 5 This is a structural block diagram of another power supply connection device according to one or more embodiments;

[0043] Figure 6 This is a structural block diagram of another power supply connection device for implementing discharge control of a converter according to one or more embodiments;

[0044] Figure 7 This is a schematic diagram of a power supply control process based on a power supply connection device according to one or more embodiments;

[0045] Figure 8 This is a schematic diagram of another power supply control process based on a power supply connection device according to one or more embodiments;

[0046] Figure 9 This is a schematic diagram of another power supply control process based on a power supply connection device according to one or more embodiments;

[0047] Figure 10 This is a structural block diagram of a battery management system, battery system, and power consumption device according to one or more embodiments;

[0048] Figure 11 This is a structural block diagram of an energy conversion system according to one or more embodiments;

[0049] Figure 12 This is a structural block diagram of an energy storage system according to one or more embodiments. Detailed Implementation

[0050] The embodiments of the technical solution of this application are described below with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0051] It should be noted that the term "embodiment" as used in this application means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0052] Unless otherwise defined, the technical and scientific terms used in the embodiments of this application have the same meaning as understood by one of ordinary skill in the art to which this application belongs. The terminology used in the embodiments of this application is for the purpose of describing the embodiments only and is not intended to limit the application.

[0053] In the description of the embodiments in this application, the term "exemplary" means "serving as an example, embodiment, or illustration." Any embodiment illustrated as "exemplary" is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0054] The terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion. The terms “first,” “second,” “third,” etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, particular order, or primary or secondary relationship of the indicated technical features. The term “multiple” means two or more (including two), unless otherwise expressly and specifically defined.

[0055] The term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " in this text generally indicates that the preceding and following related objects are in an "or" relationship.

[0056] Unless otherwise explicitly stated and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a mechanical connection or an electrical connection; they can be 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. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] Furthermore, the terms "upper," "lower," "inner," "outer," "front," "back," "left," "right," "top," and "bottom," etc., indicate the orientation or positional relationship based on the working state of the embodiments of this application. They are only used to facilitate the description of the embodiments of this application and to simplify 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.

[0058] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates 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 indicates that the first feature is at a lower horizontal level than the second feature.

[0059] In the description of the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; at the same time, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0060] In the description of the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, and other dimensions of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0061] To facilitate understanding of the technical solutions of this application, the application scenarios of the technical solutions provided in the embodiments of this application will be described by way of example below.

[0062] With the development of new energy technologies, rechargeable battery systems are widely used in power systems, energy storage systems, electric vehicles, and many other fields. A converter is typically installed between the battery system and the connected power grid or load to convert electrical energy between the battery system and the grid or load, ensuring that the electrical energy output from the battery system meets the load's power demand, or that the electrical energy provided by the grid meets the battery system's charging needs.

[0063] Figure 1 A schematic diagram illustrating an application scenario for one or more embodiments. (Refer to...) Figure 1 The battery device 10 is connected to the inverter 20. Depending on the application requirements, the inverter 20 can be connected to the power grid system 30 or to the load 40.

[0064] For example, when the converter 20 is connected to the power grid system 30, it can convert the alternating current (AC) provided by the power grid system 30 into direct current (DC) and store it in the battery device 10, or convert the direct current (DC) output by the battery device 10 into alternating current (AC) and feed it back to the power grid system 30, thereby achieving peak shaving and valley filling for the power grid system 30 and improving the power supply stability of the power grid system 30.

[0065] For example, when the inverter 20 is connected to the load 40, it can convert the direct current (DC) output from the battery device 10 into alternating current (AC) or direct current (DC) required by the load 40 to maintain the normal operation of the load 40. The load 40 can be any type of electrical equipment such as power equipment or electronic equipment.

[0066] Because the converter 20 contains capacitors for suppressing voltage fluctuations, it needs to be powered on and its capacitors charged before it can operate normally. If a short circuit occurs in the connection line (DC line) between the battery device 10 and the converter 20 while the capacitors are being charged, it could damage the battery device 10, the converter 20, and other related equipment, and even lead to serious consequences such as fire.

[0067] Therefore, in related technologies, a fuse 11 is typically installed between the battery device 10 and the inverter 20, such as... Figure 1 As shown. If a short circuit fault exists on the DC line between the battery device 10 and the inverter 20 when power is applied, the current flowing through the fuse 11 will be very large, causing the fuse 11 to blow, thus providing a certain degree of short circuit protection.

[0068] However, since short-circuit protection based on fuse 11 is passive protection, the fuse 11 requires a certain amount of time to blow. During this period, it may cause some damage to the battery system or related equipment, or even lead to more serious consequences. In addition, after short-circuit protection is achieved by the fuse 11 blowing, relevant maintenance personnel need to replace fuse 11 or the fuse in fuse 11, which will increase the workload and maintenance cost.

[0069] In view of this, in order to improve the safety of battery systems and related electrical equipment and reduce maintenance costs, embodiments of this application provide a power supply connection device. The power supply connection device includes a first branch connected between the positive terminal of the battery device and the positive terminal of the inverter. The first branch includes a first switch and a first resistor connected in series. The power supply connection device also includes a second branch formed by a second switch and a power supply connected in series. One end of the second branch is connected to the common terminal of the first switch and the first resistor, and the other end is connected to the negative terminal of the inverter.

[0070] Based on the aforementioned power supply connection device, short-circuit fault identification can be achieved during the power-on process of the converter. Specifically, when powering on the converter is required, the second switch can be closed first, and the DC-side capacitor of the converter can be charged in the first stage using the aforementioned power supply and the first resistor. If the DC-side voltage of the converter fails to reach the first voltage threshold within a first preset time period, it indicates a short-circuit fault on the DC side of the converter. In this case, the second switch can be opened to stop the charging process. Conversely, if the DC-side voltage reaches the first voltage threshold within the first preset time period, it indicates that there is no short-circuit fault on the DC side of the converter. Therefore, the second switch can be opened, the first switch closed, and the DC-side capacitor of the converter can continue to be charged in the second stage using the battery device and the first resistor, thus completing the power-on of the converter.

[0071] As can be seen, with the power supply connection device provided in this application embodiment, when the converter needs to be powered on, the DC side capacitor of the converter is first charged through the power supply. Based on whether the DC side voltage of the converter reaches a first voltage threshold within a first preset time period, a short circuit fault on the DC side of the converter is identified. If a short circuit fault is identified, charging can be stopped, and the battery device does not need to be connected to the converter, thereby avoiding damage to the battery device and other related equipment caused by the short circuit fault, improving the safety of the battery device and related electrical equipment, and avoiding additional maintenance costs.

[0072] In addition, although the power supply connection device requires a first preset time to obtain the short circuit identification result, the battery device is not connected to the inverter during the first preset time. Therefore, even if there is a short circuit fault on the DC line, it will not damage the battery device. At the same time, by using a power supply with a smaller output voltage, the impact of short circuit faults on related equipment can be reduced, the service life of related equipment can be extended, and maintenance costs can be reduced.

[0073] The power supply connection device provided in this application embodiment can be applied to various devices or systems that utilize batteries for power supply or energy storage, such as energy storage systems, power equipment (e.g., electric vehicles, electric boats, spacecraft), electronic devices (e.g., mobile phones, tablets, laptops, bionic machines, digital cameras, electric toys, etc.), and wearable devices (e.g., watches, bracelets, VR glasses, etc.). It should be understood that the power supply connection device provided in this application embodiment can also be applied to other scenarios, which will not be listed here.

[0074] The following provides an exemplary description of the power supply connection device, power supply control process based thereon, related devices, and related systems provided in the embodiments of this application.

[0075] Figure 2 This is a schematic diagram of a power supply connection device according to one or more embodiments. Referring below... Figure 2 The power supply connection device provided in the embodiments of this application will be described by way of example.

[0076] like Figure 2 As shown, the power supply connection device 200 is connected to the battery device 10 and the inverter 20 respectively, and is used to control the connection and disconnection between the battery device 10 and the inverter 20. The power supply connection device 200 includes a first branch 210 and a second branch 220.

[0077] The first branch 210 includes a first switch K1 and a first resistor R. The two ends of the first switch K1 are connected to the positive terminal of the battery device 10 and the first end of the first resistor R, respectively, and the second end of the first resistor R is connected to the positive terminal of the inverter 20.

[0078] The second branch 220 includes a second switch K2 and a power supply Us connected in series; the two ends of the second branch 220 are respectively connected to the first end of the first resistor R and the negative terminal of the converter 20.

[0079] For example, the DC side of the converter 20 is the side of the converter 20 used to connect to the battery device 10; correspondingly, the other side opposite to the DC side can be the AC side for connecting to the power grid system or AC load, and the other side opposite to the DC side can also be another DC side for connecting to a DC load.

[0080] For example, the DC side of the converter 20 is configured with a positive DC bus 20a and a negative DC bus 20b; based on this, the second end of the first resistor R is connected to the positive terminal of the converter 20, that is, connected to the positive DC bus 20a of the converter 20, and the second branch 220 is connected to the negative terminal of the converter 20, that is, connected to the negative DC bus 20b of the converter 20.

[0081] For example, a bus capacitor C, i.e., the DC-side capacitor of the converter 20, is provided between the positive DC bus 20a and the negative DC bus 20b. Based on the characteristics of a capacitor, the voltage of the bus capacitor C cannot change abruptly, thereby suppressing voltage fluctuations on the DC side of the converter 20. Therefore, the power-on process of the converter 20 includes the charging process of this bus capacitor C.

[0082] A short circuit occurs on the DC line between the battery unit 10 and the inverter 20, specifically between the positive DC bus 20a and the negative DC bus 20b. Based on the aforementioned power supply connection device 200, this short circuit fault can be actively identified; see below for details. Figure 2 The working principle of the power supply connection device 200 is explained.

[0083] Reference Figure 2 When the converter 20 is not running, the first switch K1, the second switch K2, etc. are all in the open state. When the converter 20 needs to be powered on, the second switch K2 can be closed first, so that the power supply Us, the first resistor R and the converter 20 form the first charging circuit, which can charge the DC side capacitor of the converter 20, that is, the bus capacitor C, in the first stage.

[0084] If a short circuit fault exists between the positive DC bus 20a and the negative DC bus 20b, the bus capacitor C will be short-circuited and cannot be charged, and the voltage Uc across the bus capacitor C will not rise; conversely, if there is no short circuit fault, the voltage Uc will gradually rise during the first stage of charging.

[0085] The voltage Uc across the aforementioned bus capacitor C is also the DC side voltage or bus voltage of converter 20, which is the voltage between the positive and negative terminals of the DC side of converter 20. Based on this, Uc can be used as the target voltage to identify short-circuit faults. That is, if the target voltage Uc cannot rise to the first voltage threshold U1, it indicates that there is a short-circuit fault between the positive DC bus 20a and the negative DC bus 20b. In this case, the second switch K2 can be opened to stop the first stage of charging to avoid damage to the power supply Us, converter 20, and other related components. Conversely, if the target voltage Uc can rise to the first voltage threshold U1, it indicates that the bus capacitor C can be charged normally, there is no short-circuit fault between the positive DC bus 20a and the negative DC bus 20b, and the power-on of converter 20 can continue.

[0086] For example, during the first stage of charging, the DC side of the converter 20 can also be identified by combining the duration of the charging process. That is, if the duration T1 of the first stage of charging reaches the first preset duration Ts1, and the target voltage Uc has not yet reached the first voltage threshold U1, that is, the target voltage Uc has not risen to the first voltage threshold U1 within the first preset duration Ts1, i.e., Uc < U1 and T1 ≥ Ts1, then the DC side of the converter 20 is considered to have a short circuit fault; if the target voltage Uc reaches the first voltage threshold U1, and the duration T1 of the first charging stage has not yet reached the first preset duration Ts1, that is, the target voltage Uc has risen to the first voltage threshold U1 within the first preset duration Ts1, i.e., Uc ≥ U1 and T1 < Ts1, then the DC side of the converter 20 is considered not to have a short circuit fault.

[0087] Since the voltage rise of the bus capacitor C requires a certain amount of time, exceeding this time, even if the voltage of the bus capacitor C eventually reaches the first voltage threshold U1, indicates that there is another fault on the DC side of the converter 20, such as a fault in the bus capacitor C causing slow charging. Therefore, in the above embodiment, combining the charging duration for short-circuit fault identification can promptly identify DC side faults in the converter 20, avoiding long waiting times and improving the efficiency and accuracy of fault identification.

[0088] To ensure circuit safety when charging the inverter 20 using power supply Us, a power supply with a relatively low output voltage can be used for power supply Us. Consequently, the maximum value that the target voltage Uc can reach during charging via power supply Us is limited, potentially making it difficult to meet the normal operating requirements of the inverter 20. Therefore, based on the aforementioned power supply connection device 200, when the target voltage Uc rises to the first voltage threshold U1, the first switch K1 can be closed and the second switch K2 can be opened, thereby forming a second charging circuit with the battery device 10, the first resistor R, and the inverter 20. This allows the inverter 20 to be charged in a second stage via the battery device 10, causing the target voltage Uc to continue rising until the normal operating requirements of the inverter 20 are met.

[0089] The power supply connection device 200 provided in the above embodiment can divide the power-on process of the converter 20 into two stages. In the first stage, charging is performed through the power supply Us, and the presence of a short circuit fault on the DC side of the converter 20 is identified based on the change in the DC side voltage of the converter 20, i.e., the target voltage Uc. Since the first stage does not require the battery device 10 to be connected to the converter 20, even if a short circuit fault exists, it will not damage the battery device 10. Moreover, charging can be stopped in time when a short circuit fault is detected to avoid damage to related components. Relevant maintenance personnel only need to check the short circuit fault location, without replacing fuses, circuit breakers, etc., which can reduce maintenance workload and lower maintenance costs.

[0090] If no short circuit fault is detected during the first stage of charging, the second stage of charging can continue, i.e., the first switch K1 is closed, and the converter 20 is charged through the battery device 10 until the target voltage Uc meets the normal operating requirements of the converter 20.

[0091] Therefore, based on the aforementioned power supply connection device 200, the power-on process of the converter enables active identification of short-circuit faults. This allows for normal charging of the DC-side capacitor of the converter 20 and power-on of the converter 20 even in the absence of a short-circuit fault. It also enables timely identification of short-circuit faults and termination of charging, ensuring that related equipment is not damaged due to short-circuit faults, thereby improving the safety of related equipment and systems and reducing maintenance costs.

[0092] In some embodiments, the battery device 10 described above may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar. As an example, a battery cell assembly is typically formed by arranging multiple battery cells. As an example, a battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells into a single module; as an example, a battery module may be formed by bundling multiple battery cells together with cable ties.

[0093] In some embodiments, the battery device 10 described above can be a battery pack, which includes a housing and one or more battery cell assemblies housed within the housing. As an example, the battery cell assembly can be a battery module, which can be housed within the housing by fixing the battery module to the housing. Alternatively, the battery cell assembly can be housed within the housing by directly fixing multiple battery cells to the housing.

[0094] In some embodiments, the converter 20 may include at least one of an AC-DC converter, a DC-AC converter, and a DC-DC converter.

[0095] The aforementioned AC / DC converters, such as rectifiers, are used to convert alternating current (AC) to direct current (DC). The aforementioned DC / AC converters, such as inverters, are used to convert direct current (DC) to alternating current (AC). The aforementioned DC / DC converters are used to convert direct current of one voltage to direct current of another voltage.

[0096] For example, when applied to electric vehicles, the converter 20 may include the AC / DC converter to convert the AC power output from the charging pile into DC power to charge the battery device 10 in the electric vehicle; or, the converter 20 may also include the DC / AC converter to convert the DC power output from the battery device 10 into AC power required by AC loads such as AC motors in the electric vehicle; or, the converter 20 may also include the DC / DC converter to convert the DC power output from the battery device 10 into another type of DC power required by DC loads such as electronic control systems in the electric vehicle.

[0097] For example, in the case of an energy storage power station, the converter 20 is used to realize the conversion of electrical energy between the battery device 10 and the power grid system. Therefore, the converter 20 can be a power conversion system (PCS) that includes both DC / AC and AC / DC. The PCS, also known as an energy storage converter, is used for bidirectional conversion of electrical energy to achieve peak shaving and valley filling of the power grid system. For example, during the charging process of the battery device 10, the PCS can convert the AC power of the power grid system into the DC power required by the battery device 10; and during the discharging process of the battery device 10, the PCS can convert the DC power output by the battery device 10 into the AC power required by the power grid system.

[0098] In practical applications, if the relevant load needs to be shut down, or if the battery device 10 has completed charging and discharging, the connection between the battery device 10 and the inverter 20 can be disconnected, causing the inverter 20 to stop operating. However, due to the presence of the bus capacitor C, even if the battery device 10 is disconnected from the inverter 20, the electrical energy stored in the bus capacitor C will not disappear instantly. The bus capacitor C needs a considerable amount of time to dissipate the stored electrical energy through self-discharge. That is, after the battery device 10 is disconnected from the inverter 20, the voltage across the bus capacitor C will remain high for a long time, posing a threat to the personal safety of personnel performing maintenance and other related work.

[0099] In view of this, in some embodiments, reference is made to Figure 3 The power supply connection device 200 may also include a third switch K3. One end of the third switch K3 is connected to the first end of the first resistor R, that is, the common end of the first resistor R and the first switch K1; the other end of the third switch K3 is connected to the negative terminal of the converter 20, that is, connected to the negative DC bus 20b.

[0100] based on Figure 3 The power supply connection device 200 shown can close the third switch K3 when the inverter 20 is powered off and the battery device 10 is disconnected from the inverter 20, so that the first resistor R and the inverter 20 form a discharge circuit, thereby using the first resistor R to quickly release the electrical energy stored on the bus capacitor C and quickly reduce the voltage across the bus capacitor C.

[0101] In the above embodiment, a discharge branch is provided in the power supply connection device 200. The discharge branch includes a third switch K3. When the converter 20 is powered off, a discharge circuit is formed by closing the third switch K3. The electrical energy stored in the DC side capacitor of the converter 20 is quickly released by the first resistor R, reducing the risk of electric shock to relevant personnel and reducing the difficulty of inspection and maintenance of the converter 20.

[0102] In some embodiments, during the discharge of the converter 20 by closing the third switch K3, if the duration T3 of the discharge process reaches the third preset duration Ts3, i.e., T3 > Ts3, and the target voltage Uc has not yet dropped below the third voltage threshold U3, i.e., Uc > U3, then an abnormal discharge has occurred, and the third switch K3 can be opened to stop the discharge. Conversely, if the target voltage Uc drops below the third voltage threshold U3 within the third preset duration Ts3, i.e., Uc ≤ U3 and T3 ≤ Ts3, then the DC side voltage of the converter 20 has dropped to a safe range, the discharge is complete, and the third switch K3 can be opened.

[0103] In some embodiments, refer to Figure 2 and Figure 3 The power supply connection device 200 may also include a fourth switch K4. The two ends of the fourth switch K4 are respectively connected to the positive terminal of the battery device 10 and the positive terminal of the inverter 20 (i.e., the positive DC bus 20a).

[0104] Based on the previous embodiment, if there is no short-circuit fault during the power-on process of the converter 20, the second stage of charging can be entered by closing the first switch K1, so that the target voltage Uc continues to rise. When the target voltage Uc rises to the second voltage threshold U2, it can be regarded as the end of the charging process of the DC side capacitor of the converter 20, and the converter 20 can operate normally to meet the power conversion requirements of its system. Therefore, in this case, the fourth switch K4 can be closed to short-circuit the first resistor R, thereby reducing the power consumption of the corresponding system during normal operation and improving the power utilization rate of the system.

[0105] For example, the second voltage threshold U2 can be the DC-side voltage required for the normal operation of the converter 20, and can be configured according to parameters such as the power of the converter 20. The second voltage threshold U2 is greater than the first voltage threshold U1.

[0106] For example, after closing the fourth switch K4, the first switch K1 can also be opened to completely disconnect the first resistor R from the DC line, reducing unnecessary circuit connections in the line and avoiding system failures caused by unnecessary circuit connections; at the same time, in case of emergency power outage of the converter 20, only the fourth switch K4 needs to be opened, improving the power outage response efficiency.

[0107] In some embodiments, to improve the safety of the relevant system, when entering the second stage of charging by closing the first switch K1, it can be jointly determined whether charging is complete based on the second voltage threshold U2 and the second preset duration Ts2.

[0108] Specifically, if the target voltage Uc rises to the second voltage threshold U2, and the duration of the second stage of charging has not yet reached the second preset duration Ts2, i.e., Uc≥U2 and T2<Ts2, it indicates that the second stage of charging is completed, i.e. the entire charging process of the DC side capacitor of the converter 20 is completed. Therefore, under this condition, the fourth switch K4 can be closed to allow the converter 20 and the corresponding system to enter the normal working state.

[0109] Conversely, if the duration of the second stage of charging has reached the second preset duration Ts2, but the target voltage Uc has not yet risen to the second voltage threshold U2, i.e., Uc < U2 and T2 ≥ Ts2, it indicates that there are other faults in the relevant equipment or lines. Therefore, in this case, the first switch K1 can be disconnected and the fourth switch K4 can also remain open so that relevant personnel can carry out fault diagnosis and maintenance to ensure the safety of the equipment and system.

[0110] In some embodiments, the negative terminal of the battery device 10 can be directly connected to the negative terminal (i.e., the negative DC bus 20b) of the inverter 20.

[0111] In some embodiments, the power supply connection device 200 may further include a fifth switch K5, such as... Figure 2 and Figure 3 As shown. The two ends of the fifth switch K5 are connected to the negative terminal of the battery device 10 and the negative terminal of the inverter 20, respectively. Based on this, the connection and disconnection between the negative terminal of the battery device 10 and the negative terminal of the inverter 20 can be controlled by controlling the closing and opening of the fifth switch K5.

[0112] For example, since the connection and disconnection between the battery device 10 and the inverter 20 require synchronous control of the positive and negative terminals, the opening and closing states of the negative terminal switch can be synchronously controlled based on the opening and closing states of the positive terminal-related switches. For instance, the opening and closing states of the fifth switch K5 connected to the negative terminal of the battery device 10 can be synchronously controlled based on the opening and closing states of the first switch K1 and the fourth switch K4 connected to the positive terminal of the battery device 10.

[0113] For example, if at least one of the first switch K1 and the fourth switch K4 is closed, the fifth switch K5 is also closed; if both the first switch K1 and the fourth switch K4 are open, the fifth switch K5 is also open.

[0114] In the above embodiments, by disconnecting the fifth switch K5, multiple circuits related to the battery device 10 can be quickly disconnected, improving power outage response efficiency and enhancing the safety of the related systems.

[0115] like Figure 2 and Figure 3 The power supply connection device 200 shown has a first resistor R reused in multiple circuits, such as a first charging circuit that charges the bus capacitor C through the power supply Us, a second charging circuit that charges the bus capacitor C through the battery device 10, and a discharge circuit that discharges the bus capacitor C by closing the third switch K3. This can simplify the components required for the power supply connection device 200 and reduce costs.

[0116] In some embodiments, refer to Figure 4 In the second branch 220 of the power supply connection device 200, in addition to the power supply Us and the second switch K2, a second resistor R' can also be connected in series, and the two ends of the second branch 220 are respectively connected to the positive terminal (i.e., positive DC bus 20a) and the negative terminal (i.e., negative DC bus 20b) of the converter.

[0117] based on Figure 4The power supply connection device 200 shown, when the second switch K2 is closed, forms a first charging circuit with the power supply Us, the second resistor R', and the bus capacitor C, allowing the capacitor Us to charge the bus capacitor C in the first stage as described above. When the first switch K1 is closed, the circuit formed by the battery device 10, the first resistor R, and the bus capacitor C forms a second charging circuit, allowing the battery device 10 to charge the bus capacitor C in the second stage as described above. When the third switch K3 is closed, the circuit formed by the second resistor R' and the bus capacitor C forms a discharge circuit, allowing the bus capacitor C to be discharged. Figure 4 The working principle of the power supply connection device 200 shown can also be referred to Figure 2 and Figure 3 The similarities will not be repeated here.

[0118] In addition, such as Figure 4 As shown, the power supply connection device 200 can be installed between the battery device 10 and the disconnect switch K. T Between, that is: the second terminal of the first resistor R is connected to the isolating switch K T It is connected to the positive terminal of converter 20 (i.e., positive DC bus 20a); at the same time, the third switch K3, the second branch 220, etc., are connected through the isolating switch K T It is connected to the negative terminal (i.e., negative DC bus 20b) of converter 20. Based on this, it can be connected via disconnect switch K. T This achieves isolation between the battery device 10 and the inverter 20, improving circuit safety.

[0119] In some embodiments, the power supply Us may include at least one of a DC voltage source, a switching power supply, a linear power supply, and a battery.

[0120] It is understandable that, since the bus capacitor C and the first resistor R are connected in series during the first stage of charging through the power supply Us, the maximum value that the target voltage Uc can reach during the first stage of charging is also less than the output voltage of the power supply Us. Therefore, in order to ensure that the above-mentioned power supply connection device 200 can accurately identify short circuit faults, the configured first voltage threshold U1 should be less than the output voltage of the power supply Us.

[0121] In some embodiments, the output voltage of the power supply Us, the first voltage threshold U1, the first preset duration Ts1, etc., can be configured based on factors such as the size of the first resistor R, the size of the second resistor R', and the relevant performance parameters of the second switch K2.

[0122] For example, based on Figure 2In the power supply connection device 200 shown, if a short-circuit fault exists on the DC side of the converter 20, after the second switch K2 is closed, the power supply Us, the second switch K2, and the first resistor R will be directly connected in series. The current flowing through the second switch K2 is I = Us / R. This current I must not exceed the maximum current I' that the second switch K2 can withstand. This is necessary so that in the event of a short-circuit fault, the fault can be detected during the first stage of charging without damaging the second switch K2 or incurring additional maintenance costs. Therefore, the output voltage of the power supply Us can be determined based on the value of the first resistor R and the maximum current I' that the second switch K2 can withstand, ensuring that Us < I' × R.

[0123] For example, if the second switch K2 is a relay, the output voltage of the power supply Us can be determined by referring to the welding capability of the relay contacts; if the second switch K2 is a fuse, the output voltage of the power supply Us, the first voltage threshold U1, the first preset duration Ts1, etc. can be determined by referring to the melting time of the fuse under different currents.

[0124] In addition, a second voltage threshold U2 and a second preset duration Ts2 can be configured based on factors such as the DC side voltage required for normal operation of the converter 20 and the size of the first resistor R; and a third voltage threshold U3 and a third preset duration Ts3 can be configured based on factors such as the size of the first resistor R and electrical system safety specifications. This embodiment does not limit the above circuit parameters, and those skilled in the art can configure the above circuit parameters according to actual application requirements.

[0125] In some embodiments, each of K1 to K5 in the power supply connection device 200 can be a controllable switch of any type, such as a contactor, relay, or power switching transistor. The specific configuration can be made according to the actual application requirements such as the voltage level and current carrying capacity of the corresponding switch point. This embodiment does not limit this.

[0126] In some embodiments, the power supply connection device 200 can control the closing and opening of its individual switches K1 to K5 through the relevant control unit of its system, such as the Battery Management System (BMS).

[0127] In some embodiments, the opening and closing states of each switch K1 to K5 in the power supply connection device 200 can also be controlled by hardware circuitry.

[0128] For example, such as Figure 5As shown, the power supply connection device 200 can be equipped with a voltage sampling circuit 230, a voltage comparison circuit 240, a timing circuit 250, etc., to control the second switch K2 and the first switch K1 during the first stage of charging.

[0129] The voltage sampling circuit 230 has its input terminals connected to the positive and negative terminals of the converter 20, respectively, to detect the voltage across the bus capacitor C, i.e., the target voltage Uc. The output terminal of the voltage sampling circuit 230 is connected to one input terminal of the voltage comparison circuit 240, and the other input terminal of the voltage comparison circuit 240 receives a first voltage threshold U1. The voltage comparison circuit 240 compares the magnitudes of the voltages received at its two input terminals, i.e., compares Uc and U1, and outputs a signal S1 indicating the voltage comparison result. The timing circuit 250 uses the moment when the second switch K2 closes as the start time of timing and compares it with a first preset duration Ts1 pre-configured in the timing circuit 250, outputting a signal S2 indicating the duration comparison result.

[0130] For example, the signals S1 and S2 mentioned above can be used as control signals for the first switch K1 and the second switch K2. When the signals S1 and S2 meet the corresponding conditions, they can respectively control the first switch K1 and the second switch K2 to produce corresponding actions, thereby achieving the control effects described in some of the previous embodiments. For example, in the case of a short circuit fault, the second switch K2 is opened to stop charging, and in the case of no short circuit fault, the second switch K2 is opened and the first switch K1 is closed to start the second stage of charging.

[0131] In the second stage of charging and discharging as described in some of the preceding embodiments, the control of the relevant switches can also be based on... Figure 5 The voltage sampling circuit 230, voltage comparison circuit 240, timing circuit 250, etc. shown can be configured by those skilled in the art according to application requirements, and will not be described in detail here.

[0132] One or more embodiments of this application also provide a power supply connection device 200 with another structure, such as Figure 6 As shown, the power supply connection device 200 includes a first branch 210 and a discharge branch 260.

[0133] The first branch 210 mentioned above includes a first switch K1 and a first resistor R. The two ends of the first switch K1 are respectively connected to the positive terminal of the battery device 10 and the first end of the first resistor R, and the second end of the first resistor R is connected to the positive terminal of the inverter 20, that is, connected to the positive DC bus 20a.

[0134] The aforementioned discharge branch 260 includes a third switch K3. One end of the third switch K3 is connected to the first end of the first resistor R, which is the common end of the first resistor R and the first switch K1. The other end of the third switch K3 is connected to the negative terminal of the converter 20, which is connected to the negative DC bus 20b.

[0135] In some embodiments, such as Figure 6 As shown, the power supply connection device 200 may further include: a fourth switch K4; the two ends of the fourth switch K4 are respectively connected to the positive terminal of the battery device 10 and the positive terminal of the converter 20 (i.e., the positive DC bus 20a).

[0136] In some embodiments, such as Figure 6 As shown, the power supply connection device 200 may further include a fifth switch K5; the two ends of the fifth switch K5 are respectively connected to the negative terminal of the battery device 10 and the negative terminal of the inverter 20.

[0137] based on Figure 6 The power supply connection device 200 shown can close the first switch K1 and the fifth switch K5 when the converter 20 needs to be powered on, and charge the bus capacitor C through the battery device 10. After charging is completed, the fourth switch K4 can be closed and the first switch K1 can be opened, and the converter 20 and its system can enter the normal working state.

[0138] based on Figure 6 The power supply connection device 200 shown can disconnect the connection between the battery device 10 and the converter 20 when the converter 20 needs to be powered down. That is, after disconnecting the fourth switch K4 and the fifth switch K5, the third switch K3 is closed. This allows the electrical energy stored in the DC side capacitor (i.e., bus capacitor C) of the converter 20 to be quickly released through the discharge branch 260 and the first resistor R, thereby reducing the DC side voltage of the converter 20, reducing the risk of electric shock to relevant personnel, and reducing the difficulty of inspection and maintenance of the converter 20.

[0139] Figure 7 This is a schematic diagram illustrating the power-on control process of a converter 20 implemented based on a power supply connection device 200, provided for one or more embodiments of this application. See below for reference. Figure 2 and Figure 7 The power-on control process based on the power supply connection device 200 during the power-on process of the converter 20 is illustrated by way of example.

[0140] Step S701: When the converter 20 needs to be powered on, close the second switch K2 in the power supply connection device 200.

[0141] For example, based on the relevant control signals sent by the central control unit in the relevant application scenario, such as the energy management system (EMS) in the energy storage scenario, or the vehicle control unit (VCU) in the electric vehicle, such as the power-on command, it can be determined whether the converter 20 needs to be powered on, that is, whether to execute step S701 and start the power-on control process.

[0142] When the converter 20 needs to be powered on, by executing the above step S701, the second switch K2 is closed, which can enable the power supply Us in the power supply connection device 200 and the first resistor R to form a first charging circuit with the converter 20, and perform the first stage of charging on the DC side capacitor (i.e. bus capacitor C) of the converter 20.

[0143] Step S702: Obtain the duration T1 of the first stage of charging and the target voltage Uc between the positive and negative terminals of the converter 20, and determine whether the first preset condition is met.

[0144] The aforementioned first preset condition includes that the target voltage Uc is not less than the first voltage threshold U1, and the duration T1 of the first stage of charging is less than the first preset duration Ts1, i.e., Uc≥U1 and T1<Ts1.

[0145] Step S703: If the first preset condition is not met, i.e., Uc < U1 and T1 ≥ Ts1, disconnect the second switch K2 and generate the first fault signal.

[0146] The aforementioned first fault signal indicates that there is a short circuit fault on the connection line between the power supply connection device 200 and the converter 20, that is, there is a short circuit fault on the DC side of the converter 20.

[0147] If the above preset conditions cannot be met during the first stage of charging, it means that the target voltage Uc has failed to rise to the first voltage threshold U1 within the first preset time Ts1, which means that there is a short circuit fault between the positive and negative terminals of the converter 20, thus realizing the identification of the short circuit fault. In this case, the power-on process of the converter can be ended by disconnecting K2 to ensure the safety of related equipment and systems.

[0148] For example, the aforementioned first fault signal can be reported to a control system such as a BMS so that the relevant control system or personnel can promptly investigate the short circuit fault.

[0149] Step S704: Under the condition that the first preset condition is met, i.e. Uc≥U1 and T1<Ts1, disconnect the second switch K2 and close the first switch K1 in the power supply connection device 200.

[0150] Through the above step S704, the battery device 10, the first resistor R and the inverter 20 can form a second charging circuit to charge the DC side capacitor of the inverter 20 in the second stage until the target voltage Uc meets the normal operation requirements of the inverter 20.

[0151] The power supply control process provided in the above embodiment, based on the power supply connection device 200, allows the power supply Us to charge the converter 20 in the first stage by closing the second switch K2 when the converter 20 needs to be powered on. By monitoring the target voltage Uc and the duration T1 of the first stage charging, a short circuit fault in the DC side of the converter 20 is identified. If a short circuit fault is detected, the second switch K2 is opened, the charging process stops, and a first fault signal is generated to prompt relevant personnel for timely maintenance. If no short circuit fault is detected, the first switch K1 is closed and the second switch K2 is opened, allowing the battery device 10 to continue charging the DC side capacitor of the converter 20 in the second stage until the target voltage Uc meets the normal operating requirements of the converter 20. Therefore, the above embodiment avoids connecting the battery device 10 and the converter 20 in the presence of a short circuit fault, improving the safety of related equipment and systems and reducing maintenance costs.

[0152] In some embodiments, based on Figure 3 The power supply connection device 200 shown can also be used during the power-on process of the converter 20. Figure 8 The power-on control process is shown below.

[0153] in, Figure 8 Steps S701 to S703 in the process Figure 7 The same applies here, so it will not be repeated. Corresponding to Figure 7 In step S704, Figure 8 In the process shown, if the first preset condition is met, step S704' is executed, that is, the second switch K2 is disconnected and the first switch K1 and the fifth switch K5 are closed. If the first preset condition is met, it means that the first stage of charging is completed and there is no short circuit fault. Therefore, the second stage of charging can be performed on the DC side capacitor of the inverter 20 by disconnecting K2 and closing K1 and K5 through the battery device 10.

[0154] Continue to refer to Figure 8 The above power-on control process may also include the following steps:

[0155] Step S705: During the second stage of charging, determine whether the second preset condition is met.

[0156] The aforementioned second preset conditions include: the target voltage Uc is not less than the second voltage threshold U2, and the duration T2 of the second stage charging is less than the second preset duration Ts2, i.e., Uc≥U2 and T2<Ts2.

[0157] Step S706: If the above-mentioned second preset condition is not met, disconnect the first switch K1 and the fifth switch K5, and generate a second fault signal indicating abnormal charging of the DC side capacitor of the converter 20.

[0158] If the second preset condition cannot be met during the second stage of charging, it means that the target voltage Uc cannot rise to the second voltage threshold U2 within the second preset time Ts2, which means that a charging abnormality has occurred. This indicates that there may be other faults in the relevant equipment or lines. Therefore, the second stage of charging can be ended by disconnecting K1 and K5 and generating a second fault signal to prompt relevant personnel to troubleshoot the fault and ensure the safety of the relevant equipment and system.

[0159] Step S707: Under the condition that the second preset condition is met, close the fourth switch K4 in the power supply connection device 200 and open the first switch K1 to end the second stage of charging and enable the converter 20 to operate normally.

[0160] During the second stage of charging, if the above-mentioned second preset condition is met, that is, if the target voltage Uc rises to the second voltage threshold U2 within the second preset time Ts2, which meets the normal operation requirements of the converter 20 and there is no charging abnormality, then the battery device 10 can be directly connected to the converter 20 by closing the fourth switch K4 and opening the first switch K1, and the converter 20 can start to perform power conversion.

[0161] In the above embodiment, the power-on process of the converter 20 is divided into two stages. In the first stage, by closing the second switch K2, the power supply Us charges the DC-side capacitor of the converter 20 in the first stage, and the presence of a short-circuit fault on the DC side of the converter 20 is identified based on the change in the bus voltage of the converter 20, i.e., the target voltage Uc. If no short-circuit fault is found, the process proceeds to the second stage, which involves closing the first switch K1 and the fifth switch K5 and opening the second switch K2, allowing the battery device 10 to continue charging the DC-side capacitor of the converter 20 in the second stage.

[0162] During the first stage of charging, since the battery device 10 does not need to be connected to the inverter 20, even if a short circuit fault exists, it will not damage the battery device 10. Moreover, if a short circuit fault is detected, charging can be stopped in time to avoid damage to related components. The relevant maintenance personnel only need to check the short circuit fault location, without having to replace fuses, circuit breakers, etc., which can reduce the workload of maintenance and reduce maintenance costs.

[0163] During the second stage of charging, the DC-side capacitor of the converter 20 can continue to be charged through the battery device 10. The charging abnormality can be identified based on the change of the target voltage Uc. If the charging abnormality occurs, the charging can be stopped in time to ensure the safety of related equipment and systems. If the charging abnormality does not occur, the target voltage Uc can rise to the second voltage threshold U2 to meet the normal operation requirements of the converter 20.

[0164] Therefore, based on the above power-on control process, the charging of the DC-side capacitor of the converter 20 and fault identification can be carried out simultaneously during the power-on process of the converter 20, ensuring the safety of related equipment and systems.

[0165] In some embodiments, based on Figure 3 The power supply connection device 200 shown can also achieve the following control: after the converter 20 is powered off, the third switch K3 in the power supply connection device 200 is closed to discharge the DC side capacitor of the converter 20 through the first resistor R.

[0166] In the above embodiment, a third switch K3 is provided in the power supply connection device 200. After the converter 20 is powered off, that is, after the battery device 10 is disconnected from the converter 20, that is, after the fourth switch K4 and the fifth switch K5 are both disconnected, the third switch K3 can be closed to form a discharge circuit with the converter 20. The electrical energy stored in the DC side capacitor of the converter 20 can be quickly released by the first resistor R, reducing the risk of electric shock to relevant personnel and reducing the difficulty of inspection and maintenance of the converter 20.

[0167] Figure 9 A schematic diagram of the power-down control process of the converter 20 based on the power supply connection device 200, provided for one or more embodiments. Figure 9 The power-down control flow shown is based on Figure 3 The power supply connection device 200 shown enables relevant control after the converter 20 is powered off.

[0168] For example, Figure 9 The steps shown can be used as Figure 8 The subsequent steps of step S707 shown can also be executed independently to realize the power-off control of converter 20. This embodiment does not limit this.

[0169] Reference Figure 3 and Figure 9 In some embodiments, the power-down control process described above further includes the following steps:

[0170] Step S901: When the converter 20 needs to be powered down, disconnect the fourth switch K4 and the fifth switch K5, and close the third switch K3 to discharge the DC side capacitor of the converter 20.

[0171] For example, based on the relevant control signals sent by the central control unit in the relevant application scenario, such as EMS, VCU, etc., such as power-off command, it can be determined whether the converter 20 needs to be powered off, that is, whether to execute step S901 and start the power-off control process.

[0172] When the inverter 20 needs to be powered down, the battery device 10 can be disconnected from the inverter 20 by opening the fourth switch K4 and the fifth switch K5. Furthermore, by closing the third switch K3, the first resistor R and the DC-side capacitor of the inverter 20 can form a discharge circuit, quickly releasing the electrical energy stored in the DC-side capacitor of the inverter 20.

[0173] Step S902: During the discharge process, determine whether the third preset condition is met.

[0174] The aforementioned third preset condition includes: the duration T3 of discharging the DC-side capacitor of the converter 20 is not greater than the third preset duration Ts3, and the target voltage Uc is not greater than the third voltage threshold U3, that is, T3≤Ts3 and Uc≤U3.

[0175] Step S903: If the above-mentioned third preset condition is not met, a third fault signal indicating abnormal discharge of the DC side capacitor of the converter 20 is generated.

[0176] If the third preset condition is not met, that is, during the discharge of the DC side capacitor of the converter 20, the target voltage Uc fails to drop to the third voltage threshold U3 within the third preset time Ts3, it indicates that there is a fault factor in the circuit that affects the discharge. Therefore, a third fault signal can be generated to prompt relevant personnel to troubleshoot and repair, so as to prevent the DC side from maintaining a high voltage after the converter 20 is powered off.

[0177] For example, in step S903, in addition to generating the third fault signal, the third switch K3 can also be disconnected to avoid affecting subsequent maintenance, power-on and other operations.

[0178] Step S904: If the above-mentioned third preset condition is met, disconnect the third switch K3 to end the discharge.

[0179] If the third preset condition is met, that is, during the discharge of the DC side capacitor of the converter 20, the target voltage Uc has dropped to the third voltage threshold U3 within the third preset time Ts3, it means that there are no fault factors in the circuit that affect the discharge, and the DC side voltage of the converter 20 has dropped to a safe range, so the discharge can be ended.

[0180] In the above embodiments, during the discharge of the DC-side capacitor of the converter 20 based on the third switch K3, the circuit can be identified as to whether there is a discharge abnormality or whether the discharge is completed, based on the change of the target voltage Uc. This allows the third switch K3 to be disconnected in time and the discharge to be automatically ended without human intervention, thereby improving control efficiency and the safety of related equipment and operators.

[0181] Below, refer to Figure 3 , Figure 8 and Figure 9 The power supply connection device and the converter power-on and power-off control process implemented thereon provided in this application are illustrated by way of an optional embodiment.

[0182] like Figure 3 As shown, one side of the power supply connection device 200 is connected to the battery device 10, and the other side is connected to the inverter 20. It can be used to control the connection or disconnection of the DC line between the battery device 10 and the inverter 20. A bus capacitor C is provided on the DC side of the inverter 20 for connection with the battery device 10.

[0183] The power supply connection device 200 includes a fourth switch K4 connected in series between the positive terminal of the battery device 10 and the positive terminal of the inverter 20, and a fifth switch K5 connected in series between the negative terminal of the battery device 10 and the negative terminal of the inverter 20. The fourth switch K4 and the fifth switch K5 can be regarded as the main circuit switches of the power supply connection device 200.

[0184] The power supply connection device 200 also includes a first branch 210 connected in parallel with the fourth switch K4. The first branch 210 includes a first switch K1 and a first resistor R connected in series.

[0185] The power supply connection device 200 also includes a second branch 220. One end of the second branch 220 is connected to the common terminal of the first switch K1 and the first resistor R, and the other end is connected to the negative terminal of the converter 20. The second branch 220 includes a second switch K2 and a power supply Us connected in series.

[0186] The power supply connection device 200 also includes a discharge branch, which includes a third switch K3, one end of which is connected to the common terminal of the first switch K1 and the first resistor R, and the other end is connected to the negative terminal of the converter 20. That is, this discharge branch is connected in parallel with the second branch 220.

[0187] Based on the aforementioned power supply connection device 200, when the converter 20 needs to be powered on, the following can be performed: Figure 8 The power-on control process is shown below:

[0188] Close the second switch K2 (i.e. step S701) so that the power supply Us can use the first resistor R to charge the DC side capacitor of the converter 20, i.e. the bus capacitor C, in the first stage.

[0189] During the first stage of charging, monitor whether the duration T1 of the first stage of charging exceeds the first preset duration Ts1, and detect whether the voltage across the bus capacitor C, i.e. the target voltage Uc, reaches the first voltage threshold U1 (i.e. step S702).

[0190] If the duration T1 of the first stage of charging is detected to exceed the first preset duration Ts1, but the target voltage Uc does not rise or rises very little and does not reach the first voltage threshold U1, then the second switch K2 is disconnected, charging is stopped, and a first fault signal indicating that there is a short circuit fault is generated. This signal is reported to the relevant control system or to the relevant maintenance personnel to indicate that there is a short circuit fault on the DC side of the converter 20 (i.e., step S703).

[0191] If Uc≥U1 and T1<Ts1 is detected, that is, through the first stage of charging, the voltage across the bus capacitor C can rise to the first voltage threshold U1 within the first preset time Ts1, indicating that there is no short circuit fault on the DC side of the converter 20; therefore, the second switch K2 can be opened, and the first switch K1 and the fifth switch K5 can be closed, so that the battery device 10 can continue to charge the bus capacitor C using the first resistor R for the second stage of charging (i.e., step S704').

[0192] During the second stage of charging, it is possible to monitor whether the duration T2 of the second stage of charging exceeds the second preset duration Ts2, and whether the target voltage Uc reaches the second voltage threshold U2 (i.e., step S705).

[0193] If it is detected that T2 exceeds the second preset time Ts2, but the target voltage Uc has not yet reached the second voltage threshold U2, the first switch K1 and the fifth switch K5 can be disconnected to end charging and generate a second fault signal indicating charging abnormality, which is reported to the relevant control system or alerts the relevant maintenance personnel that a charging abnormality fault has occurred (i.e., step S706).

[0194] If Uc≥U2 and T2<Ts2 is detected, it indicates that the second stage of charging is complete. Therefore, the fourth switch K4 can be closed and the first switch K1 can be opened to end the charging and allow the converter 20 to enter the normal working state (i.e., step S707).

[0195] Based on the aforementioned power supply connection device 200, when the converter 20 needs to be powered down, the following can be performed: Figure 9 The power-down control process is shown below:

[0196] Disconnect the fourth switch K4 and the fifth switch K5 to disconnect the DC line between the battery device 10 and the inverter 20, and close the third switch K3 to quickly discharge the DC side capacitor of the inverter 20 using the first resistor R, that is, quickly release the electrical energy stored on the bus capacitor C (i.e., step S901).

[0197] During the discharge process, it is possible to monitor whether the duration T3 of the discharge process exceeds the third preset duration Ts3, and whether the target voltage Uc drops to the third voltage threshold U3 (i.e., step S902).

[0198] If it is detected that T3 exceeds the third preset time Ts3, but the target voltage Uc has not dropped to the third voltage threshold U3, it indicates that there is a discharge abnormality. Therefore, a third fault signal indicating the discharge abnormality can be generated and reported to the relevant control system or alerted to relevant personnel.

[0199] If T3≤Ts3 and Uc≤U3 are detected, it indicates that there is no discharge abnormality and the target voltage Uc has dropped to a safe range. Therefore, the third switch K3 can be disconnected to end the discharge.

[0200] As can be seen, the power supply connection device 200 and the control flow implemented thereon provided in the above embodiments can identify short-circuit faults through the second branch 220 when the converter 20 needs to be powered on, without being connected to the battery device 10, so that the converter 20 and related systems will not be damaged due to short-circuit faults. If no short-circuit fault is identified, the first branch 210 can continue to charge the DC-side capacitor of the converter 20, so that the related systems can operate normally. In addition, after the converter 20 is powered off, that is, after the fourth switch K4 and the fifth switch K5 are both open, the discharge branch can be used to discharge the DC-side capacitor of the converter 20, quickly reducing its DC-side bus voltage and avoiding the risk of electric shock and maintenance difficulties.

[0201] It should be noted that in practical application scenarios, the above-described power-on and power-off control procedures for converter 20, i.e. Figures 7-9 The control process described above can be implemented through the voltage sampling circuit 230, voltage comparison circuit 240, timing circuit 250, etc. in the power supply connection device 200, or through a related controller or control system (such as BMS). This embodiment does not limit this.

[0202] It is understood that the above embodiments are merely examples, and modifications can be made to the above embodiments in actual implementation. Those skilled in the art will understand that any modifications to the above embodiments that do not require creative effort fall within the protection scope of this application, and will not be described in detail in the embodiments.

[0203] Based on the same inventive concept, this application also provides a battery management system, referring to... Figure 10 The battery management system 1011 includes the power supply connection device 200 described in any of the above embodiments. The battery management system 1011 can connect to the battery device 10 and the inverter 20 via the power supply connection device 200. It can control the connection and disconnection between the battery device 10 and the inverter 20 based on control signals sent by the upper-level control system (such as the vehicle controller in an electric vehicle or the energy management system in an energy storage system) for the corresponding application scenario. It can also detect and report the status information of the battery device 10, such as temperature and remaining charge, thereby managing the battery device 10.

[0204] Based on the same inventive concept, this application also provides a battery system. (Refer to...) Figure 10 The battery system 1010 may include: a battery device 10, and a battery management system 1011 connected to the battery device 10.

[0205] In some embodiments, the battery management system 1011 may further include a controller, which may be configured to execute the power-on or power-off control process provided in any of the above embodiments, for controlling the power supply connection device 200 according to the power-on or power-off command to the external device (such as the inverter 20), so as to realize the safe connection and disconnection between the battery system 1010 and the external device (such as the inverter 20).

[0206] Based on the same inventive concept, this application also provides an electrical device, referring to... Figure 10 The electrical device 1000 may include an electrical load 1020, a converter 20 and the aforementioned battery system 1010. The battery system 1010 is connected to the electrical load 1020 through the converter 20, thereby supplying power to the electrical load 1020.

[0207] For example, the electrical device 1000 can be, but is not limited to, power equipment (such as electric vehicles, electric boats, spacecraft), electronic equipment (such as mobile phones, tablets, laptops, bionic machines, digital cameras, electric toys, etc.), wearable devices (such as watches, bracelets, VR glasses, etc.), energy storage power stations, etc.

[0208] Based on the same inventive concept, embodiments of this application also provide an energy conversion system. (Refer to...) Figure 11 The energy conversion system 1100 may include a converter 20 and a power supply connection device 200 connected to the converter 20; the power supply connection device 200 may be any of the power supply connection devices described in the preceding embodiments. The energy conversion system 1100 is also connected to the battery device 10 through the power supply connection device 200 for controlling the connection and disconnection between the converter 20 and the battery device 10.

[0209] For example, the energy conversion system 1100 also connects to external devices (such as inverters) via the inverter 20. Figure 1 The load 40 or power grid system 30 shown is connected to realize the conversion of electrical energy between the battery device 10 and external devices.

[0210] In some embodiments, the energy conversion system 1100 further includes a control unit for controlling the inverter 20. The control unit may be configured with the power supply control process provided in any of the above embodiments to control the power supply connection device 200 according to the power-on command or power-off command of the inverter 20, so as to realize the connection and disconnection between the inverter 20 and the external battery device 10.

[0211] Based on the same inventive concept, embodiments of this application also provide an energy storage system. (Refer to...) Figure 12 The energy storage system 1200 may include a battery device 10, a power supply connection device 200, and a converter 20. The power supply connection device 200 may be any of the power supply connection devices described in the preceding embodiments. The power supply connection device 200 is connected to both the battery device 10 and the converter 20, and is used to control the connection and disconnection between the battery device 10 and the converter 20. The converter 20 is used to realize the conversion of electrical energy between the battery device 10 and external devices (such as the power grid system or load) of the energy storage system 1200.

[0212] The specific connection methods and control processes between the battery devices, power supply connection devices and converters involved in the above systems can be referred to the relevant embodiments above, and will not be repeated here.

[0213] The battery management system, battery system, power device, energy conversion system, energy storage system, etc. provided in the above embodiments, can identify short circuit faults, charging abnormalities, etc. that may exist during the power-on process, and quickly release the electrical energy stored in the relevant equipment when the power is off, under the premise of ensuring that the relevant system can be powered on and off normally, thereby improving the safety of the relevant system and reducing maintenance costs.

[0214] Based on the same inventive concept, embodiments of this application also provide an electronic device, which includes a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so as to cause the electronic device to perform... Figure 7 , Figure 8 and Figure 9 The control flow shown in any one of the options controls the state of each switch in the power supply connection device 200 to realize the power-on or power-off control of the converter.

[0215] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when run on an electronic device, causes the electronic device to perform... Figure 7 , Figure 8 and Figure 9 The control flow shown in any one of the options controls the state of each switch in the power supply connection device 200 to realize the power-on or power-off control of the converter.

[0216] Based on the same inventive concept, this application also provides a computer program product, which includes a computer program that, when run on an electronic device, causes the electronic device to perform... Figure 7 , Figure 8 and Figure 9 The control flow shown in any one of the options controls the state of each switch in the power supply connection device 200 to realize the power-on or power-off control of the converter.

[0217] Those skilled in the art will recognize that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0218] If these functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the power supply control process described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0219] In the several embodiments provided in this application, it should be understood that the disclosed devices, systems, and electronic devices can be implemented in other ways. For example, the embodiments of devices, systems, and electronic devices described above are merely illustrative; multiple components may be combined or integrated into another system, or some features may be omitted or not performed. Furthermore, the mutual couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections between devices or units through some interfaces, and may be electrical, mechanical, or other forms.

[0220] It should be understood that in the various embodiments of this application, the execution order of each step should be determined by its function and internal logic, and the size of each step number does not mean the order of execution, and does not constitute a limitation on the implementation process of the embodiments.

[0221] The various parts of this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on the differences from other embodiments. For relevant parts, please refer to the description in the test system embodiment.

[0222] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Those skilled in the art will understand the specific meaning of the above terms in this application according to the specific circumstances. It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or substitution of these aspects and / or embodiments. Moreover, each aspect and / or embodiment of this application can be used alone or in combination with one or more other aspects and / or embodiments thereof.

[0223] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of this application.

Claims

1. A power supply connection device, characterized in that, The power supply connection device is used to control the connection and disconnection between the battery device and the inverter. The power supply connection device includes: a first branch and a second branch. The first branch includes a first switch and a first resistor. The two ends of the first switch are respectively connected to the positive terminal of the battery device and the first end of the first resistor, and the second end of the first resistor is connected to the positive terminal of the inverter. The second branch includes a second switch and a power supply connected in series. The two ends of the second branch are respectively connected to the first end of the first resistor and the negative terminal of the converter. The output voltage of the power supply is related to the resistance value of the first resistor and the maximum current that the second switch can withstand. The output voltage of the power supply is less than the output voltage of the battery device. Specifically, when the second switch is closed and the first switch is open, the power supply charges the DC-side capacitor of the converter through the first resistor, and the two ends of the DC-side capacitor are respectively connected to the positive and negative terminals of the converter; when the second switch is open and the first switch is closed, the battery device charges the DC-side capacitor through the first resistor.

2. The apparatus according to claim 1, characterized in that, Also includes: The third switch is connected at both ends to the first end of the first resistor and the negative terminal of the converter, respectively. When the converter is powered off, the first switch and the second switch are open, and the third switch is closed, so as to discharge the DC-side capacitor through the first resistor.

3. The apparatus according to claim 1 or 2, characterized in that, Also includes: The fourth switch has its two ends connected to the positive terminal of the battery device and the positive terminal of the inverter, respectively. The fourth switch closes when the DC-side capacitor has finished charging. The fourth switch is disconnected when the converter needs to be powered off.

4. The apparatus according to claim 3, characterized in that, Also includes: The fifth switch has its two ends connected to the negative terminal of the battery device and the negative terminal of the inverter, respectively. The fifth switch is closed if at least one of the first and fourth switches is closed; The fifth switch is disconnected when the converter needs to be powered down.

5. The apparatus according to claim 1 or 2, characterized in that, The power source includes at least one of a DC voltage source, a switching power supply, a linear power supply, and a battery; The first switch includes at least one of a contactor, a relay, and a power switching transistor; The second switch includes at least one of a contactor, a relay, and a power switching transistor.

6. The apparatus according to claim 1 or 2, characterized in that, The second switch closes when the converter needs to be powered on, so that the power supply can charge the DC-side capacitor in the first stage. The second switch is turned off to stop the first stage of charging when the duration of the first stage of charging is not less than a first preset duration and the target voltage is less than a first voltage threshold. The target voltage is the voltage between the positive and negative terminals of the converter.

7. The apparatus according to claim 6, characterized in that, During the first stage of charging of the DC-side capacitor by the power supply, if the target voltage is not less than the first voltage threshold, the second switch is opened and the first switch is closed, so that the battery device can charge the DC-side capacitor in the second stage.

8. The apparatus according to claim 6, characterized in that, When a fourth switch is connected in series between the positive terminal of the battery device and the positive terminal of the inverter, during the second stage of charging of the DC-side capacitor by the battery device, the fourth switch closes when the target voltage is not less than a second voltage threshold, wherein the second voltage threshold is greater than the first voltage threshold.

9. A power supply connection device, characterized in that, The power supply connection device is used to control the connection and disconnection between the battery device and the inverter. The power supply connection device includes: a first branch and a second branch. The first branch includes a first switch and a first resistor connected in series, and the two ends of the first branch are respectively connected to the positive terminal of the battery device and the positive terminal of the inverter; The second branch includes a second switch, a power supply, and a second resistor connected in series. The two ends of the second branch are respectively connected to the positive terminal and the negative terminal of the converter. The output voltage of the power supply is related to the resistance value of the second resistor and the maximum current that the second switch can withstand. The output voltage of the power supply is less than the output voltage of the battery device. Specifically, when the second switch is closed and the first switch is open, the power supply charges the DC-side capacitor of the converter through the second resistor, and the two ends of the DC-side capacitor are respectively connected to the positive and negative terminals of the converter; when the second switch is open and the first switch is closed, the battery device charges the DC-side capacitor through the first resistor.

10. A battery management system, characterized in that, include: The power supply connection device according to any one of claims 1 to 9, wherein the battery management system is used to control the charging and discharging of the battery device to external devices.

11. A battery system, characterized in that, include: The battery device and the battery management system of claim 10.

12. An electrical appliance, characterized in that, include: An electrical load, a converter, and the battery system of claim 11, the battery system being used to supply power to the electrical load via the converter.

13. An energy conversion system, characterized in that, include: A converter and a power supply connection device connected to the converter; The power supply connection device is the power supply connection device according to any one of claims 1 to 9, and the power supply connection device is also connected to the battery device for controlling the connection and disconnection between the inverter and the battery device; The converter is also connected to an external device to enable the conversion of electrical energy between the battery device and the external device.

14. An energy storage system, characterized in that, The energy storage system includes: a battery device, a power supply connection device, and a converter; The power supply connection device is connected to the battery device and the inverter respectively, and is used to control the connection and disconnection between the battery device and the inverter; the power supply connection device is the power supply connection device according to any one of claims 1 to 9; The converter is used to realize the electrical energy conversion between the battery device and the external equipment of the energy storage system.

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