Self-adaptive energy storage device with neutral line, judgment method and power supply system

Abstract

The invention discloses a method for judging whether a neutral line exists in an energy storage device and a converter device connected with the energy storage device and a power supply system, the energy storage device is provided with a positive electrode output end, a negative electrode output end and a neutral line output end, and the method comprises the following steps: completing wiring of the energy storage device and the converter device; when the energy storage device is in a turn-off state and the converter device is in a state of charging the energy storage device, obtaining two port voltages when the energy storage device meets a preset condition, and judging whether a voltage difference change of the two port voltages when the preset condition is met is within a preset range; if the result is yes, judging that the connected converter device has a center line, otherwise, judging that the connected converter device has no center line; and the port voltage is the voltage between the neutral line output end and the positive pole output end or the negative pole output end. Whether the converter device has the center line or not can be detected through the energy storage device side, so that conditions are created for automatic operation of the energy storage device.

Description

Technical Field

[0001] This invention relates to the field of power supply, and specifically to an adaptive energy storage device with or without a neutral line, a method for determining this, and a power supply system. Background Technology

[0002] An uninterruptible power supply (UPS) is a power supply system that connects an energy storage device to a converter. When the mains power is normal, the converter charges the energy storage device. When the mains power is abnormal, the converter converts the DC power from the energy storage device into mains power.

[0003] There are two models of power converters: one with a neutral wire and one without. To match different models of power converters, energy storage devices are generally equipped with a neutral wire output terminal. When the power converter has a neutral wire, the positive terminal, negative terminal, and neutral wire terminal of the power converter are connected to the positive output terminal, negative output terminal, and neutral wire output terminal of the energy storage device, respectively. When the power converter does not have a neutral wire, the positive terminal and negative terminal of the power converter are connected to the positive output terminal and negative output terminal of the energy storage device, respectively. Therefore, the operation of the energy storage device will change when the power converter has a neutral wire and when it does not. In actual applications, the cables of the power converter and the energy storage device are pre-connected, but the energy storage device cannot automatically identify whether the power converter has a neutral wire. On-site users need to manually turn on the energy storage device and control its operation after determining whether a neutral wire is present, which cannot achieve automated operation and is time-consuming and labor-intensive. Summary of the Invention

[0004] The purpose of this invention is to overcome the aforementioned defects or problems in the prior art and to provide an adaptive energy storage device with or without a neutral line, a method for determining whether a converter connected to it has or does not have a neutral line, and a power supply system. This system can detect whether a converter connected to it has a neutral line from the energy storage device side, thereby creating conditions for the automated operation of the energy storage device.

[0005] To achieve the above objectives, the present invention and its related embodiments adopt the following technical solutions, but are not limited to the following solutions:

[0006] The first technical solution and its related embodiments relate to a method for determining whether an energy storage device and its connected converter have a neutral line. The energy storage device is provided with connection terminals, including a positive output terminal, a negative output terminal, and a neutral line output terminal. The method involves: completing the wiring between the energy storage device and the converter; when the energy storage device is in a turned-off state and the converter is charging the energy storage device, acquiring the two port voltages of the energy storage device when a preset condition is met, and determining whether the voltage difference change of the two port voltages when the preset condition is met is within a preset range; if the result is yes, it is determined that the converter connected to it has a neutral line; otherwise, it is determined that the converter connected to it has no neutral line; the port voltage is the voltage between the neutral line output terminal and the positive output terminal or the negative output terminal.

[0007] The second technical solution is based on the first technical solution and is a preferred embodiment of the first technical solution. It further includes a voltage acquisition device; it defines either the positive output terminal or the negative output terminal as the detection output terminal; the voltages of the two ports are the maximum voltage value and the minimum voltage value detected by the voltage acquisition device between the neutral output terminal and the detection output terminal within a set period; if the difference between the maximum voltage value and the minimum voltage value is within a preset range, it is determined that the converter connected to it has a neutral line; otherwise, it is determined that the converter connected to it has no neutral line.

[0008] The third technical solution is based on the first technical solution and is a preferred embodiment of the first technical solution. It further includes a voltage acquisition unit and a voltage divider unit; either the positive output terminal or the negative output terminal is defined as a detection output terminal; either the positive output terminal or the negative output terminal is defined as a connection output terminal; the voltage divider unit is connected in series between the neutral output terminal and the connection output terminal and is adapted to establish a path between them; the two port voltages are respectively the first voltage when a path exists between the neutral output terminal and the detection output terminal, and the second voltage when no path exists; if the difference between the first voltage and the second voltage is within a preset range, it is determined that the converter connected to it has a neutral line; otherwise, it is determined that the converter connected to it has no neutral line.

[0009] The fourth technical solution is based on the third technical solution and is a preferred embodiment of the third technical solution. In this solution, the voltage divider unit includes a voltage divider resistor and a voltage divider switch connected in series. When the voltage divider switch is closed, a path is established between the neutral output terminal and the connected output terminal. When the voltage divider switch is open, there is no path between the neutral output terminal and the connected output terminal.

[0010] The fifth technical solution is based on the fourth technical solution and is a preferred embodiment of the fourth technical solution. Specifically, when the detected output terminal is a positive output terminal, if the connected output terminal is a positive output terminal, the first voltage is less than the second voltage, and the difference between the two is not within a preset range, the control unit controls the neutral line switch to open; otherwise, it is determined that the converter connected to it has a neutral line. If the connected output terminal is a negative output terminal, the first voltage is greater than the second voltage, and the difference between the two is greater than a first threshold, it is determined that the converter connected to it has no neutral line; otherwise, it is determined that the converter connected to it has a neutral line. Similarly, when the detected output terminal is a negative output terminal, if the connected output terminal is a positive output terminal, the first voltage is greater than the second voltage, and the difference between the two is greater than a first threshold, it is determined that the converter connected to it has no neutral line; otherwise, it is determined that the converter connected to it has a neutral line. If the connected output terminal is a negative output terminal, the first voltage is less than the second voltage, and the difference between the two is greater than a first threshold, it is determined that the converter connected to it has no neutral line; otherwise, it is determined that the converter connected to it has a neutral line.

[0011] The sixth technical solution relates to an adaptive energy storage device with or without a neutral line. The energy storage device includes a first DC power supply module and a second DC power supply module with equal voltage. The energy storage device also includes a neutral line switch and a control unit. The control unit performs any one of the solutions one to five. The first DC power supply module and the second DC power supply module are adapted to be connected in series or in parallel. The neutral line switch is connected in series between the negative terminal of the first DC power supply module or the positive terminal of the second DC power supply module and the neutral line output terminal. The control unit is also adapted to close the neutral line switch when the first DC power supply module and the second DC power supply module are connected in series and it is determined that the converter connected to them has a neutral line.

[0012] The seventh technical solution is based on the sixth technical solution and is a preferred embodiment of the sixth technical solution. The energy storage device further includes a series-parallel switching module. The series-parallel switching module includes a first switch for connecting the first DC power supply module and the second DC power supply module in series, a second switch for connecting the positive terminals of the first DC power supply module and the second DC power supply module in parallel, and a third switch for connecting the negative terminals of the first DC power supply module and the second DC power supply module in parallel. The control unit is adapted to acquire the operating voltage and operating current of the converter, and when the operating voltage is greater than a first set value and the energy storage device is in a discharging state, it controls the first switch to close so that the first DC power supply module and the second DC power supply module are connected in series. The control unit also controls the second and third switches to close so that the first DC power supply module and the second DC power supply module are connected in parallel when the operating current is greater than a second set value and the energy storage device is in a discharging state.

[0013] The eighth technical solution is based on the seventh technical solution and is a preferred embodiment of the seventh technical solution. The first DC power supply module includes N first DC power supply modules, and the second DC power supply module includes M second DC power supply modules; where N and M are both positive integers. The series-parallel switching module includes a fourth switching unit for connecting the first DC power supply modules in series and a fifth switching unit for connecting the first DC power supply modules in parallel when N is greater than 1; and a seventh switching unit for connecting the second DC power supply modules in series and an eighth switching unit for connecting the second DC power supply modules in parallel when M is greater than 1. The control unit... When the operating voltage is greater than a first set value, the energy storage device is in a discharging state, and N is greater than 1, the control unit controls the number of the first and second DC power supply modules connected according to the operating voltage; when the operating current is greater than a first set value, the energy storage device is in a discharging state, and M is greater than 1, the control unit controls the number of the first and second DC power supply modules connected according to the operating current; the control unit is adapted to shut down the energy storage device when the operating demand of the converter changes, and after a set time, switch the connection mode of the first and second DC power supply modules and the neutral line switch according to the acquired information.

[0014] The ninth technical solution and its related embodiments relate to a power supply system, including an energy storage device as described in any one of technical solutions six to eight, and a converter device, which is a first converter device or a second converter device electrically coupled to the energy storage device, wherein the first converter device includes a neutral potential point and the second converter device does not include a neutral potential point.

[0015] As can be seen from the above description of the present invention and its specific embodiments, compared with the prior art, the technical solution of the present invention and its related embodiments have the following beneficial effects due to the adoption of the following technical means:

[0016] Through continuous observation, experimentation, and research, the applicant has come to the conclusion that the reason why the energy storage device cannot operate automatically in the existing technical solution is that the energy storage device cannot determine whether the converter has a neutral line, and therefore manual intervention is required after determining whether the converter has a neutral line.

[0017] In the first technical solution and related embodiments, the wiring between the energy storage device and the converter is first completed. At this time, the energy storage device is in a turned-off state because it is unaware whether the converter has a neutral wire, in order to ensure the output safety of the energy storage device. The converter charges the energy storage device, and the output terminal of the energy storage device is also energized. The voltages of the two ports of the energy storage device when the preset conditions are met are obtained, and it is determined whether the voltage difference change of the two port voltages when the preset conditions are met is within a preset range. If the result is yes, it is determined that the converter has a neutral wire; otherwise, the converter does not have a neutral wire, and the port voltage is the voltage between the neutral wire output terminal and the positive output terminal or the negative output terminal. This is because when the converter has a neutral wire... The positive and negative voltages of the converter are controlled independently, and the port voltage remains essentially unchanged. When the converter has no neutral wire, the difference between the positive and negative voltages is stable. Therefore, under different detection conditions, the port voltage will change to varying degrees. Thus, the presence of a neutral wire in the converter can be determined by detecting changes in the port voltage under different conditions. Once a neutral wire is detected, the neutral wire switch is closed, making the neutral wire output terminal of the energy storage device conductive. Otherwise, the neutral wire output terminal is not conductive. This allows the energy storage device to be matched with both converters with and without neutral wires, enabling it to automatically adapt to different types of converters after operation. Those skilled in the art will understand that when the neutral wire switch is closed, the voltage between the positive and neutral wire output terminals is equal to the voltage between the neutral wire and negative output terminals.

[0018] In the second technical solution and related embodiments, when the converter has a neutral line, the port voltage between the neutral line output terminal and the detection output terminal remains basically unchanged, that is, the maximum voltage value and the minimum voltage value are basically equal within the set period. When the converter does not have a neutral line, the voltage between the neutral line output terminal and the detection output terminal fluctuates, that is, there will be a maximum voltage value and a minimum voltage value within the set period, and the difference between the two will exceed the preset range. Therefore, it can be determined that the converter does not have a neutral line and the neutral line switch is disconnected. This judgment method is simple and easy to implement.

[0019] In the second technical solution and related embodiments, the first voltage between the neutral output terminal and the detection output terminal of the energy storage device when there is a path between the neutral output terminal and the connection output terminal, and the second voltage when there is no path, are detected. If the difference between the first voltage and the second voltage exceeds a preset range, it is determined that the converter connected to it has no neutral line; otherwise, the converter has a neutral line. This is because when the converter has a neutral line, the positive and negative voltages of the converter are controlled separately. Therefore, the voltage between the neutral output terminal and the detection output terminal will not change whether there is a path between the neutral output terminal and the connection output terminal. When the converter has no neutral line, the difference between the positive and negative voltages of the converter is stable. After a path is formed between the neutral output terminal and the connection output terminal, a leakage current will be formed, causing the voltage corresponding to the detection output terminal to change. Therefore, the energy storage device can determine whether the converter connected to it has a neutral line by comparing the change in the difference between the first voltage and the second voltage, thereby controlling the neutral line switch to close or open. This judgment method is simple to calculate and easy to implement. When comparing the difference between the first voltage and the second voltage, both the first voltage and the second voltage correspond to the detection output terminal. However, the connection output terminal and the detection output terminal can be the same or different. This is because when the converter has no neutral line, the change in the voltage at the positive output terminal will inevitably be accompanied by the change in the voltage at the negative output terminal. Therefore, even if the detection output terminal and the connection output terminal are different, it can be determined whether there has been a change in the path corresponding to the connection output terminal. The voltage divider unit establishes a path between the neutral line output terminal and the connection output terminal, which is low in cost, easy to operate, and safe to use.

[0020] In the fourth technical solution and related embodiments, a path is formed by closing the voltage divider switch, and the path is disconnected by opening the voltage divider switch, which is easy to control.

[0021] In the fifth technical solution and related embodiments, several judgment scenarios are described when the connection output terminal and the detection output terminal are the same and different, and voltage changes can be detected in each scenario. Specifically, when the detection output terminal is a positive output terminal, if the connection output terminal is also a positive output terminal, the positive voltage decreases due to leakage current after the path is formed, thus the first voltage is less than the second voltage. If the connection output terminal is a negative output terminal, the negative voltage decreases due to leakage current after the path is formed, thus the voltage between the neutral output terminal and the negative output terminal decreases, and the difference between the positive and negative voltages... The value remains unchanged, the positive voltage increases, therefore the first voltage is greater than the second voltage; when the detection output terminal is the negative output terminal, if the connected output terminal is the positive output terminal, after the circuit is formed, the positive voltage decreases due to the leakage current. Since the difference between the positive and negative voltages remains unchanged, the voltage between the neutral output terminal and the negative output terminal increases, therefore the first voltage is greater than the second voltage; if the connected output terminal is the negative output terminal, after the circuit is formed, the negative voltage decreases due to the leakage current, therefore the voltage between the neutral output terminal and the negative output terminal decreases, therefore the first voltage is less than the second voltage.

[0022] In the sixth technical solution and related embodiments, the control unit is also adapted to close the neutral line switch when the first DC power supply module and the second DC power supply module are connected in series and it is determined that the converter has a neutral line, thereby ensuring the automated operation of the energy storage device.

[0023] In the seventh technical solution and related embodiments, the control unit controls the series-parallel switching of the first DC power supply module and the second DC power supply module according to the operating voltage and operating current of the converter, so that the energy storage device can also adapt to the operating requirements of the converter. Compared with manually adjusting the series-parallel connection of the first DC power supply module and the second DC power supply module, the energy storage device can switch in real time, making its operation more flexible. Specifically, when the converter requires a large voltage, controlling the first switch to close and connecting the first DC power supply module and the second DC power supply module in series can enable the energy storage device to output a large output voltage. When the converter not only requires a large voltage but also has a neutral line, controlling the first switch to close and connecting the first DC power supply module and the second DC power supply module in series and closing the neutral line switch can enable the energy storage device to output a large output voltage and have a neutral line. When the converter requires a large current, controlling the second switch and the third switch to close and connecting the first DC power supply module and the second DC power supply module in parallel can enable the energy storage device to output a large output current.

[0024] In the eighth technical solution and related embodiments, to address different operational requirements of the converter, such as the converter requiring high voltage but with varying values, or the converter requiring high current but with varying values, as long as the voltages of the first DC power supply module and the second DC power supply module are equal, the first DC power supply module can achieve different output currents and voltages by combining the first DC power supply modules within the first DC power supply module in series. Similarly, the second DC power supply module can achieve different output currents and voltages by combining the second DC power supply modules within the second DC power supply module in series and parallel. For example, when the first DC power supply module includes four first DC power supply modules, the four first DC power supply modules can be connected in series to output a first voltage value through the fourth switching unit, or the fourth switching unit and the fifth switching unit can be used to achieve the same output current and voltage. The switching unit coordinates to connect two of the four first DC power supply modules in series as a group, and the two groups are then connected in parallel to form a first DC power supply module with a second voltage value; or, depending on the requirements of the converter, only one or two first DC power supply modules are connected. Therefore, technical solution eight can further meet the various operating requirements of the converter. When the converter is replaced, the requirements of the converter will change. At this time, the energy storage device is first turned off, and the control unit determines the configuration and requirements of the converter before controlling the switching of the connection methods of the first DC power supply module, the second DC power supply module, each first DC power supply module, each second DC power supply module, and the neutral line switch. This avoids confusion between the previous and next operating modes of the energy storage device, making the switching of the connection methods of the first DC power supply module and the second DC power supply module safe and reliable.

[0025] The ninth technical solution is equivalent to any of the sixth to eighth technical solutions in terms of technical effect. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments are briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the power supply system of Embodiment 1 of the present invention, wherein the converter is a first converter.

[0028] Figure 2 This is a schematic diagram of the power supply system of Embodiment 1 of the present invention, wherein the converter is a second converter.

[0029] Figure 3 This is a schematic diagram of the energy storage unit according to Embodiment 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of the power supply system of Embodiment 2 of the present invention, wherein the converter is a first converter.

[0031] Figure 5 This is a schematic diagram of the power supply system of Embodiment 3 of the present invention, wherein the converter is a first converter.

[0032] Figure 6 This is a schematic diagram of the power supply system of Embodiment 4 of the present invention, wherein the converter is a first converter.

[0033] Figure 7 This is a schematic diagram of the power supply system of Embodiment 5 of the present invention, wherein the converter is the first converter.

[0034] Explanation of key figure labels:

[0035] Energy storage device 100; positive output terminal 11; negative output terminal 12; neutral output terminal 13; energy storage unit 20; first DC power supply module 21; first DC power supply module 211; second DC power supply module 22; second DC power supply module 221; first switch S1; second switch S2; third switch S3; neutral switch S0; voltage divider unit 30; voltage divider resistor R; voltage divider switch Sr; control unit 40; voltage acquisition device 50; converter 200. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Unless otherwise expressly defined, the use of terms such as "first," "second," or "third" in the claims, description, and accompanying drawings of this invention is for distinguishing different objects and not for describing a specific order.

[0038] Unless otherwise expressly defined, in the claims, description, and accompanying drawings of this invention, the use of directional terms such as "center," "lateral," "longitudinal," "horizontal," "vertical," "top," "bottom," "inner," "outer," "upper," "lower," "front," "rear," "left," "right," "clockwise," and "counterclockwise" to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific scope of protection of this invention.

[0039] Unless otherwise expressly defined, the terms "fixed connection" or "fixed connection" used in the claims, description and drawings of this invention should be interpreted broadly to refer to any connection in which there is no displacement or relative rotation relationship between the two parties, including non-removable fixed connection, detachable fixed connection, integral connection and fixed connection by other means or components.

[0040] In the claims, description and accompanying drawings of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0041] Example 1

[0042] See Figure 1-2 , Figure 1-2 A power supply system is shown, including an energy storage device 100 and a converter 200. The energy storage device 100 has a positive output terminal 11, a negative output terminal 12, and a neutral output terminal 13. The converter 200 is either a first converter 200 or a second converter 200 electrically coupled to the energy storage device 100. See [reference needed]. Figure 1 The first converter 200 includes a neutral potential point and is used to connect to the positive output terminal 11, the negative output terminal 12, and the neutral output terminal 13. See [link to relevant documentation]. Figure 2 The second converter 200 does not include a neutral potential point and is used to connect only to the positive output terminal 11 and the negative output terminal 12.

[0043] See Figure 1-2 The energy storage device 100 includes a connection terminal, an energy storage unit 20, a neutral line switch S0, a voltage acquisition unit 50, and a control unit 40.

[0044] The connection terminals include a positive output terminal 11, a negative output terminal 12, and a neutral output terminal 13; either the positive output terminal 11 or the negative output terminal 12 is defined as the connection output terminal. Either the positive output terminal 11 or the negative output terminal 12 is defined as the detection output terminal. The connection terminals serve as the external power connection ports for the entire energy storage device 100.

[0045] The energy storage unit 20 is adapted to be connected to the positive output terminal 11 and the negative output terminal 12, and is also adapted to be connected to the neutral output terminal 13 through the neutral line switch S0; specifically, the energy storage unit 20 includes a first DC power supply module 21 and a second DC power supply module 22 with equal voltage; the first DC power supply module 21 and the second DC power supply module 22 are adapted to be connected in series or in parallel, and the neutral line switch S0 is connected in series between the negative terminal of the first DC power supply module 21 or the positive terminal of the second DC power supply module 22 and the neutral output terminal 13.

[0046] The energy storage unit 20 also includes a series-parallel switching module; the series-parallel switching module includes a first switch S1 for connecting the first DC power supply module 21 and the second DC power supply module 22 in series, a second switch S2 for connecting the positive terminals of the first DC power supply module 21 and the second DC power supply module 22 in parallel, and a third switch S3 for connecting the negative terminals of the first DC power supply module 21 and the second DC power supply module 22 in parallel.

[0047] The first DC power supply module 21 includes N first DC power supply modules 211, and the second DC power supply module 22 includes M second DC power supply modules 221; where N and M are both positive integers.

[0048] The energy storage unit 20 can be in the form of an energy storage box including a battery pack, a first DC / DC converter unit, and a second DC / DC converter unit. Each energy storage unit 20 is provided with a positive terminal, a negative terminal, and a neutral terminal for connecting to the positive output terminal 11, the negative output terminal 12, and the neutral output terminal 13, respectively. The low-voltage side of the first DC / DC converter unit and the second DC / DC converter unit is connected to the battery pack. The high-voltage side of the first DC / DC converter unit and the second DC / DC converter unit are provided with positive and negative terminals, forming a first DC power supply module 21 and a second DC power supply module 22, respectively. In this case, one converter device 200 can correspond to multiple energy storage units 20. Multiple energy storage units 20 are connected in parallel. The series-parallel switching module and the neutral switch S0 are all located in the energy storage box. The number of neutral switches S0 corresponds to the number of energy storage units 20.

[0049] Of course, in other embodiments, the energy storage unit 20 can be in the form of an energy storage cabinet including multiple parallel energy storage modules. Each energy storage module is in the form of an energy storage box including a battery pack, a first DC / DC conversion unit, and a second DC / DC conversion unit. The low-voltage side of the first DC / DC conversion unit and the second DC / DC conversion unit is connected to the battery pack. The positive terminals of the corresponding first DC / DC conversion unit and the corresponding second DC / DC conversion unit in each energy storage module are connected in parallel to form the positive terminals of the first DC power supply module 21 and the second DC power supply module 22, respectively. The negative terminals of the corresponding first DC / DC conversion unit and the corresponding second DC / DC conversion unit in each energy storage module are connected in parallel to form the negative terminals of the first DC power supply module 21 and the second DC power supply module 22, respectively. In this case, the number of energy storage units 20 corresponds to the number of converter devices 200. The series-parallel switching module and the neutral line switch S0 are both located outside the energy storage box, and only one set of each series-parallel switching module and neutral line switch S0 needs to be set. Figure 1-2 The energy storage unit 20 is in the form of an energy storage cabinet.

[0050] In practical applications, the first DC / DC conversion unit includes N first DC / DC converters, and the second DC / DC conversion unit includes M second DC / DC converters. The input terminals of the first DC / DC converters and the input terminals of each second DC / DC converter are connected to the battery pack. The high-voltage side is provided with a positive terminal and a negative terminal. The first DC / DC converters and the second DC / DC converters respectively form the first DC power supply module 211 and the second DC power supply module 221.

[0051] See Figure 3 When N is greater than 1, the series-parallel switching module includes a fourth switching unit for implementing the series connection of each of the first DC power supply modules 211. Figure 3 (Switching unit S4), and the fifth switching unit used to realize the parallel connection of each of the first DC power supply modules 211. Figure 3 (Switches S5 and S6), when M is greater than 1, include a seventh switch unit for implementing the series connection of each second DC power supply module 221. Figure 3 The middle switch S7) and the eighth switch unit (for realizing the parallel connection of each second DC power supply module 221) Figure 3 (Switches S8 and S9). It should be understood that in other embodiments, the first DC power supply module 21 may include N (N>1) first DC power supply modules 211, while the second DC power supply module 22 may include one second DC power supply module 221, or the first DC power supply module 21 may include one first DC power supply module, while the second DC power supply module 22 may include M (M>1) second DC power supply modules.

[0052] The control unit 40 is adapted to acquire the two port voltages of the energy storage device 100 when the energy storage device 100 is in the off state and the converter 200 is in the state of charging the energy storage device 100, and determine whether the voltage difference change of the two port voltages when the preset conditions are met is within a preset range; if the result is yes, the control unit controls the neutral line switch S0 to close, otherwise the control unit controls the neutral line switch S0 to open; the port voltage is the voltage between the neutral line output terminal 13 and the positive output terminal 11 or the negative output terminal 12.

[0053] In this embodiment, the voltages at the two ports are the maximum and minimum voltage values ​​detected by the voltage acquisition device 50 between the neutral output terminal 13 and the detection output terminal within a set period. If the difference between the maximum and minimum voltage values ​​is within a preset range, the neutral switch S0 is closed; otherwise, the neutral switch S0 is opened.

[0054] In addition to the difference between having and not having a neutral line, the converter 200 also has different operating requirements. Some converters 200 require large current, while others require large voltage. Therefore, the energy storage device 100 in this embodiment is optimally adapted to the operating requirements of the converter 200.

[0055] The control unit 40 is adapted to acquire the operating voltage and operating current of the converter 200, and controls the first switch S1 to close when the operating voltage is greater than a first set value and the energy storage device 100 is in a discharging state, so that the first DC power supply module 21 and the second DC power supply module 22 are connected in series; the control unit 40 also controls the second switch S2 and the third switch S3 to close when the operating current is greater than a second set value and the energy storage device 100 is in a discharging state, so that the first DC power supply module 21 and the second DC power supply module 22 are connected in parallel. A conductive connecting piece can be used instead of a switch; when both connection terminals are connected to the same conductive connecting piece, the effect is the same as closing a switch.

[0056] When both N and M are greater than 1, the control unit 40 controls the number of the first DC power supply module 211 and the second DC power supply module 221 connected according to the operating voltage when the operating voltage is greater than the first set value, the energy storage device 100 is in a discharging state, and N is greater than 1. When the operating current is greater than the first set value, the energy storage device 100 is in a discharging state, and M is greater than 1, the control unit 40 controls the number of the first DC power supply module 211 and the second DC power supply module 221 connected according to the operating current. If the converter 200 requires a large voltage, but the values ​​of the large voltages are not the same, or the converter 200 requires a large current, but the values ​​of the large currents are not the same, then as long as the voltages of the first DC power supply module 21 and the second DC power supply module 22 are equal, the first DC power supply module 21 can be made to have different output currents and output voltages by combining the first DC power supply modules 211 in the first DC power supply module 21 in series, and the second DC power supply module 22 can be made to have different output currents and output voltages by combining the second DC power supply modules 221 in series and parallel.

[0057] For example, although both the first converter 200 and the second converter 200 require a large voltage, the required large voltage value is less than the voltage value when each of the first DC power supply modules 211 is connected in series, each of the second DC power supply modules 221 is connected in series, and the first DC power supply module 21 and the second DC power supply module 22 are connected in series. At this time, the fourth switch unit and the fifth switch unit can cooperate to make two of the four first DC power supply modules 211 connected in series as a group, and the two groups are then connected in parallel to form the first DC power supply module 21 with the second voltage value. Similarly, the second DC power supply module 22 can output the second voltage value.

[0058] The control unit 40 is adapted to shut down the energy storage unit 20 when the operating requirements of the converter 200 change, and after a set time, based on the acquired information (whether the converter has a neutral line, the operating voltage and operating current of the converter), switch the connection mode of the first DC power supply module 21 and the second DC power supply module 22, the connection mode of each first DC power supply module 211, the connection mode of each second DC power supply module 221, and shut down the neutral line switch S0.

[0059] In this embodiment, the method by which the energy storage device 100 determines whether the converter 200 connected to it has a neutral line specifically includes the following steps:

[0060] S1: Complete the wiring between the energy storage device 100 and the converter 200, and put the energy storage device 100 in the off state and the converter 200 in the state of charging the energy storage device 100.

[0061] In this step, the wiring between the energy storage device 100 and the converter 200 is completed first. At this time, the energy storage device 100 is in a turned-off state because it does not know whether the converter 200 has a neutral wire, so as to ensure the output safety of the energy storage device 100. The converter 200 charges the energy storage device 100, and the output terminal of the energy storage device 100 is also energized.

[0062] S2: Obtain the voltages at the two ports of the energy storage device 100 when the preset conditions are met, and determine whether the voltage difference change between the two ports when the preset conditions are met is within the preset range; if the result is yes, control the neutral line switch to close, otherwise control the neutral line switch to open.

[0063] In this step, the voltage acquisition device 50 detects the voltage values ​​between the neutral output terminal 13 and the positive output terminal 11 of the energy storage device 100 within a set period and sends them to the control unit 40. The voltage acquisition device 50 continuously acquires the voltage between the neutral output terminal 13 and the positive output terminal 11. The largest voltage value is the maximum voltage value, and the smallest voltage value is the minimum voltage value. The control unit 40 receives the voltage values ​​and compares the difference between the maximum and minimum voltage values. It determines whether the difference is within a preset range. If it is, it determines that the converter 200 connected to it has no neutral line and disconnects the neutral line switch S0. Otherwise, the converter 200 has a neutral line and closes the neutral line switch S0.

[0064] In this embodiment, when the converter 200 has a neutral line, the positive and negative voltages of the converter 200 are controlled independently, and the port voltage between the neutral line output terminal 13 and the detection output terminal remains basically unchanged. That is, the maximum and minimum voltage values ​​within the set period are basically equal. When the converter 200 has no neutral line, the difference between the positive and negative voltages of the converter 200 is stable, and the voltage between the neutral line output terminal 13 and the detection output terminal fluctuates. Therefore, there will be a maximum voltage value and a minimum voltage value within the set period, and the difference between the two will exceed the preset range. Thus, it can be determined that the converter 200 has no neutral line, and the neutral line switch S0 is disconnected. This judgment method is simple and easy to implement. Once a neutral line is detected, the neutral line switch S0 is closed, thus making the neutral line output terminal 13 of the energy storage device 100 conductive. Otherwise, the neutral line output terminal 13 is not conductive, so that the energy storage device 100 can be matched with both the converter 200 with and without a neutral line, and the energy storage device 100 can automatically adapt to different types of converters 200 after it is in operation.

[0065] In this embodiment, the control unit 40 controls the series-parallel switching of the first DC power supply module 21 and the second DC power supply module 22 according to the operating voltage and operating current of the converter 200, so that the energy storage device 100 can also adapt to the operating requirements of the converter 200. Compared with manually adjusting the series-parallel connection of the first DC power supply module 21 and the second DC power supply module 22, the energy storage device 100 can switch in real time, making its operation more flexible.

[0066] When the converter 200 is replaced, the requirements of the converter 200 will change. At this time, the energy storage unit 20 is turned off first. The control unit 40 determines the configuration and requirements of the converter and then controls the switching of the connection mode of the first DC power supply module 21 and the second DC power supply module 22, the connection mode of each first DC power supply module 211, the connection mode of each second DC power supply module 221, and the turn-off of the neutral line switch S0. This avoids confusion between the previous working mode and the next working mode of the energy storage unit 20, and makes the switching of the connection mode of each DC power supply module 21 safe and reliable.

[0067] Example 2

[0068] Example 2 is basically the same as Example 1, except that, see [link to example]. Figure 4 It also includes a voltage divider unit 30 and a voltage acquisition unit 50.

[0069] The voltage divider unit 30 is connected in series between the neutral output terminal 13 and the connection output terminal and is adapted to establish a path between the two. In this embodiment, both the connection output terminal and the detection output terminal are positive output terminals 11. The voltage divider unit 30 includes a voltage divider resistor R and a voltage divider switch Sr connected in series. When the voltage divider switch Sr is closed, a path is established between the neutral output terminal 13 and the connection output terminal. When the voltage divider switch Sr is open, there is no path between the neutral output terminal 13 and the connection output terminal.

[0070] The voltage acquisition unit 50 acquires the voltage between the neutral output terminal 13 and the positive output terminal 11 and transmits it to the control unit 40. The control unit 40 communicates with the series-parallel switching module, the neutral switch S0, the voltage divider switch Sr, the voltage acquisition unit 50, and the converter 200.

[0071] The control unit 40 is adapted to detect, when the energy storage unit 20 and the converter 200 are connected, the energy storage unit 20 is in the off state and the converter 200 is charging the energy storage unit 20, the control unit 40 detects the first voltage between the neutral output terminal 13 and the positive output terminal 11 of the energy storage unit 20 when there is a path between the neutral output terminal 13 and the positive output terminal 11 and the second voltage when there is no path. If the difference between the first voltage and the second voltage exceeds the first threshold, it is determined that the converter 200 connected to it has no neutral line, that is, the converter 200 is determined to be the second converter 200, thereby controlling the neutral line switch S0 to open; otherwise, the converter 200 has a neutral line, that is, the converter 200 is determined to be the first converter 200, thereby controlling the neutral line switch S0 to close.

[0072] The method by which the energy storage device 100 determines whether the converter 200 connected to it has a neutral line specifically includes the following steps:

[0073] S1: Complete the wiring between the energy storage device 100 and the converter 200, and put the energy storage device 100 in the off state and the converter 200 in the state of charging the energy storage device 100.

[0074] In this step, the wiring between the energy storage device 100 and the converter 200 is completed first. At this time, the energy storage device 100 is in a turned-off state because it does not know whether the converter 200 has a neutral wire, so as to ensure the output safety of the energy storage device 100. The converter 200 charges the energy storage device 100, and the output terminal of the energy storage device 100 is also energized.

[0075] S2: The voltage acquisition unit 50 detects the first voltage when there is a connection between the neutral output terminal 13 and the positive output terminal 11 of the energy storage device 100 and the second voltage when there is no connection, and sends it to the control unit 40.

[0076] In this step, the voltage acquisition unit 50 continuously acquires the voltage between the neutral output terminal 13 and the positive output terminal 11. When the control unit 40 controls the voltage divider switch Sr to close, a path is established between the neutral output terminal 13 and the positive output terminal 11. When the control unit 40 controls the voltage divider switch Sr to open, the path between the neutral output terminal 13 and the positive output terminal 11 is broken.

[0077] S3: The control unit 40 receives the first voltage and the second voltage, and compares the difference between the first voltage and the second voltage. If the first voltage is less than the second voltage and the difference between the first voltage and the second voltage exceeds the first threshold, it is determined that the converter 200 connected to it has no neutral line; otherwise, the converter 200 has a neutral line.

[0078] This is because when the converter 200 has a neutral line, the positive and negative voltages of the converter 200 are controlled independently. Therefore, the voltage between the neutral line output terminal 13 and the positive output terminal 11 will not change whether a path exists between the neutral line output terminal 13 and the connected output terminal. When the converter 200 has no neutral line, the difference between the positive and negative voltages of the converter 200 is stable. After a path is formed between the neutral line output terminal 13 and the connected output terminal, a leakage current will be generated, causing the voltage corresponding to the connected output terminal to change. Corresponding to the connected output terminal being the positive output terminal 11 in this embodiment, after the path is formed between the positive output terminal 11 and the neutral line output terminal 13, the positive voltage drops due to the leakage current, resulting in the first voltage being less than the second voltage. Therefore, the energy storage device 100 can determine whether the converter 200 connected to it has a neutral line by comparing the change in the difference between the first voltage and the second voltage. It can be seen that this judgment method is simple to calculate and easy to implement.

[0079] Based on the above method, the energy storage device 100 closes the neutral line switch S0 when it determines that the converter 200 has a neutral line, and opens the neutral line switch S0 when it determines that the converter 200 does not have a neutral line. Therefore, the energy storage device 100 can adapt to both converters 200 with and without a neutral line in a series configuration.

[0080] Example 3

[0081] The power supply system of Example 3 is basically the same as that of Example 2, except that, see [link to example 2] Figure 5 The output terminal is the negative output terminal 12. The voltage divider unit 30 of the energy storage device 100 is connected in series between the neutral output terminal 13 and the negative output terminal 12. When the first voltage is greater than the second voltage and the difference between the two is greater than the first threshold, the control unit 40 determines that the converter 200 connected to it has no neutral line and controls the neutral line switch S0 to open; otherwise, the converter 200 has a neutral line and controls the neutral line switch S0 to close.

[0082] In this embodiment, after the voltage divider unit 30 forms a path between the neutral output terminal 13 and the negative output terminal 12, the negative voltage decreases due to leakage current, and thus the voltage between the neutral output terminal 13 and the negative output terminal 12 decreases. Since the difference between the positive voltage and the negative voltage remains unchanged, the positive voltage increases, and therefore the first voltage is greater than the second voltage.

[0083] Example 4

[0084] The power supply system of Example 4 is basically the same as that of Example 2, see [link / reference]. Figure 6 The difference is that the detection output terminal is the negative output terminal 12. That is, the voltage acquisition device 50 of the energy storage device 100 collects the first voltage when there is a path between the neutral output terminal 13 and the negative output terminal 12 and the second voltage when there is no path. When the first voltage is greater than the second voltage and the difference between the two is greater than the first threshold, the control unit 40 determines that the converter 200 connected to it has no neutral line and controls the neutral line switch S0 to open. Otherwise, the converter 200 has a neutral line and controls the neutral line switch S0 to close.

[0085] In this embodiment, after the voltage divider unit 30 forms a path between the neutral output terminal 13 and the positive output terminal 11, the positive voltage decreases due to leakage current. Since the difference between the positive and negative voltages remains unchanged, the voltage between the neutral output terminal 13 and the negative output terminal 12 increases. Therefore, the first voltage is greater than the second voltage.

[0086] Example 5

[0087] The power supply system of Example 5 is basically the same as that of Example 4, except that, see [link to example 4] Figure 7 The output terminal is the negative output terminal, and the voltage divider unit 30 of the energy storage device 100 is connected in series between the neutral output terminal 13 and the negative output terminal 12. When the first voltage is less than the second voltage and the difference between the two is greater than the first threshold, the control unit 40 determines that the converter 200 connected to it has no neutral line and controls the neutral line switch S0 to open; otherwise, the converter 200 has a neutral line and controls the neutral line switch S0 to close.

[0088] In this embodiment, after the voltage divider unit 30 forms a path between the neutral output terminal 13 and the negative output terminal 12, the negative voltage decreases due to leakage current, and thus the voltage between the neutral output terminal 13 and the negative output terminal 12 decreases, so the first voltage is less than the second voltage.

[0089] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A method for determining whether an energy storage device (100) and its connected converter (200) have a neutral line, wherein the energy storage device (100) is provided with connection terminals, including a positive output terminal (11), a negative output terminal (12), and a neutral line output terminal (13); characterized in that, The method is as follows: Complete the wiring between the energy storage device (100) and the converter (200); When the energy storage device (100) is in the off state and the converter (200) is in the state of charging the energy storage device (100), the voltages of the two ports of the energy storage device (100) when the preset conditions are met are obtained, and it is determined whether the voltage difference change of the two ports when the preset conditions are met is within the preset range. If the result is yes, it is determined that the converter (200) connected to it has a neutral line; otherwise, it is determined that the converter (200) connected to it has no neutral line. The port voltage is the voltage between the neutral output terminal (13) and the positive output terminal (11) or the negative output terminal (12).

2. The method for determining whether there is a neutral line between an energy storage device (100) and its connected converter (200) as described in claim 1, characterized in that, It also includes a voltage acquisition unit (50); Define either the positive output terminal (11) or the negative output terminal (12) as the detection output terminal; The two port voltages are the maximum and minimum voltage values ​​detected by the voltage acquisition unit (50) between the neutral output terminal (13) and the detection output terminal during the set period; If the difference between the maximum voltage value and the minimum voltage value is within the preset range, it is determined that the converter (200) connected to it has a neutral line; otherwise, it is determined that the converter (200) connected to it has no neutral line.

3. The method for determining whether there is a neutral line between the energy storage device (100) and its connected converter (200) as described in claim 1, characterized in that, It also includes a voltage acquisition unit (50) and a voltage divider unit (30); Define either the positive output terminal (11) or the negative output terminal (12) as the detection output terminal; define either the positive output terminal (11) or the negative output terminal (12) as the connection output terminal; the voltage divider unit (30) is connected in series between the neutral output terminal (13) and the connection output terminal and is adapted to establish a path between the two; The two port voltages are the first voltage when there is a path between the neutral output terminal (13) and the detection output terminal of the voltage acquisition unit (50) and the connection output terminal, and the second voltage when there is no path. If the difference between the first voltage and the second voltage is within a preset range, it is determined that the converter (200) connected to it has a neutral line; otherwise, it is determined that the converter (200) connected to it has no neutral line.

4. The method for determining whether an energy storage device and its connected converter (200) have a neutral line as described in claim 3, characterized in that, The voltage divider unit (30) includes a voltage divider resistor (R) and a voltage divider switch (Sr) connected in series; when the voltage divider switch (Sr) is closed, a path is established between the neutral output terminal (13) and the connection output terminal; when the voltage divider switch (Sr) is open, there is no path between the neutral output terminal (13) and the connection output terminal.

5. The method for determining whether an energy storage device and its connected converter (200) have a neutral line as described in claim 4, characterized in that, When the detection output terminal is the positive output terminal (11), if the connected output terminal is the positive output terminal (11), the first voltage is less than the second voltage and the difference between the two is not within the preset range, then it is determined that the converter (200) connected to it has no neutral line; otherwise, it is determined that the converter (200) connected to it has a neutral line. If the connected output terminal is the negative output terminal (12), the first voltage is greater than the second voltage and the difference between the two is greater than the first threshold, then it is determined that the converter (200) connected to it has no neutral line; otherwise, it is determined that the converter (200) connected to it has a neutral line. When the detection output terminal is the negative output terminal (12), if the connected output terminal is the positive output terminal (11), the first voltage is greater than the second voltage and the difference between the two is greater than the first threshold, then it is determined that the converter (200) connected to it has no neutral line; otherwise, it is determined that the converter (200) connected to it has a neutral line. If the connected output terminal is the negative output terminal (12), the first voltage is less than the second voltage and the difference between the two is greater than the first threshold, then it is determined that the converter (200) connected to it has no neutral line; otherwise, it is determined that the converter (200) connected to it has a neutral line.

6. An adaptive energy storage device with or without a centerline (100), characterized in that, The energy storage device (100) includes a first DC power supply module (21) and a second DC power supply module (22) with equal voltage. The energy storage device (100) also includes a neutral line switch (S0) and a control unit (40). The control unit (40) performs the judgment method as described in any one of claims 1-5. The first DC power supply module (21) and the second DC power supply module (22) are adapted to be connected in series or in parallel, and the neutral line switch (S0) is connected in series between the negative terminal of the first DC power supply module (21) or the positive terminal of the second DC power supply module (22) and the neutral line output terminal (13). The control unit (40) is also adapted to close the neutral line switch (S0) when the first DC power supply module (21) and the second DC power supply module (22) are connected in series and it is determined that the converter (200) connected to it has a neutral line.

7. The adaptive energy storage device (100) with or without a centerline as described in claim 6, characterized in that, The energy storage device (100) also includes a series-parallel switching module; The series-parallel switching module includes a first switch (S1) for connecting the first DC power supply module (21) and the second DC power supply module (22) in series, a second switch (S2) for connecting the positive terminals of the first DC power supply module (21) and the second DC power supply module (22) in parallel, and a third switch (S3) for connecting the negative terminals of the first DC power supply module (21) and the second DC power supply module (22) in parallel. The control unit (40) is also adapted to acquire the operating voltage and operating current of the converter (200), and control the first switch (S1) to close so that the first DC power supply module (21) and the second DC power supply module (22) are connected in series when the operating voltage is greater than the first set value and the energy storage device (100) is in a discharging state; the control unit (40) also controls the second switch (S2) and the third switch (S3) to close so that the first DC power supply module (21) and the second DC power supply module (22) are connected in parallel when the operating current is greater than the second set value and the energy storage device (100) is in a discharging state.

8. The adaptive energy storage device (100) with or without a centerline as described in claim 7, characterized in that, The first DC power supply module (21) includes N first DC power supply modules (211), and the second DC power supply module (22) includes M second DC power supply modules (221); where N and M are both positive integers; the series-parallel switching module includes a fourth switching unit for realizing the series connection of each first DC power supply module (211) and a fifth switching unit for realizing the parallel connection of each first DC power supply module (211) when N is greater than 1, and a seventh switching unit for realizing the series connection of each second DC power supply module (221) and an eighth switching unit for realizing the parallel connection of each DC power supply module when M is greater than 1; When the operating voltage is greater than the first set value, the energy storage device (100) is in a discharging state, and N is greater than 1, the control unit (40) controls the number of the first DC power supply module (211) and the second DC power supply module (221) connected according to the operating voltage. When the operating current is greater than the first set value, the energy storage device (100) is in a discharging state, and M is greater than 1, the control unit (40) controls the number of the first DC power supply module (211) and the second DC power supply module (221) connected according to the operating current. The control unit (40) is adapted to shut down the energy storage device (100) when the operating requirements of the converter (200) change, and after a set time, switch the connection mode of the first DC power supply module (21) and the second DC power supply module (22), the connection mode of each first DC power supply module (211), the connection mode of each second DC power supply module (221), and the shutdown of the neutral line switch (S0) according to the information obtained.

9. A power supply system, characterized in that, include Energy storage device (100), as described in any one of claims 6-8; and A converter (200) is a first converter or a second converter electrically coupled to an energy storage device (100), wherein the first converter includes a neutral potential point and the second converter does not include a neutral potential point.

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