A charging and discharging control method, device and charging system

Abstract

The application provides a charging and discharging control method and device and a charging system, and relates to the technical field of energy storage. The method comprises the following steps: acquiring preset configuration information corresponding to a current charging and discharging stage, wherein the preset configuration information at least comprises voltage configuration information of a first direct current terminal; and setting the voltage of the first direct current terminal according to the voltage configuration information of the first direct current terminal, so that the second power conversion module works in a unidirectional mode, and the unidirectional mode comprises a charging mode and a discharging mode. Thus, by controlling the output voltage of the second power conversion module, the second power conversion module works in the unidirectional mode, and the voltage of the second power conversion module is stable, which is more conducive to protecting the safety of V2G equipment and the upper distribution, and prolonging the service life of the equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a charging and discharging control method, device and charging system. BACKGROUND

[0002] With the large-scale development of new energy vehicles, vehicle-to-grid interaction is becoming more frequent, and power grid load is further increasing. In order to implement the strategy of "carbon peak" and "carbon neutral", support the construction of new energy system and new power system, and promote the integration and interaction of new energy vehicles and power grid, it is necessary to further expand the scale of vehicle-to-grid (V2G) projects, improve the intelligent development of charging and discharging facilities, and realize the collaborative innovation of V2G technology and mode.

[0003] V2G technology is based on the interaction between electric vehicles and power grids to realize the bidirectional flow of energy, and uses a large number of electric vehicle batteries as a buffer zone for renewable energy sources. Through V2G, when the power grid load is low and the electricity price is low, the battery needs to be charged by the electric vehicle to store excess energy, and vice versa. The electric vehicle can feed power to the power grid through the V2G device, and also create income for electric vehicle users.

[0004] In existing V2G products, in order to adapt to more scenarios (such as vehicle-to-grid V2G, off-grid power supply V2L, etc.), the three-phase four-wire design is often used in the selection of bidirectional ACDC (Alternating Current to Direct Current) modules. Therefore, during the charging process, when the PCS source fails suddenly, in order to prevent the relay from sticking, the envelope + relay current judgment method is often used as the shutdown condition (the relay changes from closed to open). However, during V2G charging operation, because the power remains during the charging process, the bidirectional DCDC (Direct Current to Direct Current) module has not been able to shut down, and the bidirectional ACDC can only be blocked while the relay cannot be opened, causing the bidirectional ACDC to work in a non-controlled rectification state. Due to the three-phase four-wire topology, the neutral line current is three times the phase current, which can cause the device operating current to exceed the design specifications of the upper power distribution, and if not handled in time, it can cause damage to the device and trigger the upper power distribution trip. SUMMARY

[0005] The present application provides a charging and discharging control method, device and charging system to solve the problem that the device is easily damaged by current impact in the prior art.

[0006] To achieve the above object, the technical scheme adopted by the embodiments of the present application is as follows:

[0007] In a first aspect, embodiments of this application provide a charging and discharging control method applied to a control module in a bidirectional power conversion device. The bidirectional power conversion device further includes: a first power conversion module and a second power conversion module. The control module is connected to the second power conversion module. The AC terminal of the first power conversion module is connected to a preset AC distribution network. The DC terminal of the first power conversion module is connected to a first DC terminal of the second power conversion module. The second DC terminal of the second power conversion module is connected to a battery in an energy storage module. The method includes:

[0008] Obtain the preset configuration information corresponding to the current charging and discharging stage, wherein the preset configuration information includes at least: the voltage configuration information of the first DC terminal;

[0009] The voltage of the first DC terminal is set according to the voltage configuration information of the first DC terminal, so that the second power conversion module operates in unidirectional mode, which includes charging mode and discharging mode.

[0010] Optionally, the voltage configuration information of the first DC terminal includes: a first voltage;

[0011] If the first voltage configuration is less than the DC bus voltage of the first power conversion module, then the second power conversion module operates in the charging mode;

[0012] If the first voltage configuration is greater than the DC bus voltage of the first power conversion module, then the second power conversion module operates in the discharge mode.

[0013] Optionally, the preset configuration information further includes: voltage configuration information of the second DC terminal, wherein the voltage configuration information of the second DC terminal includes: a second voltage; the step of setting the voltage of the first DC terminal according to the voltage configuration information of the first DC terminal includes:

[0014] Based on the first voltage and the second voltage, the voltages of the first DC terminal and the second DC terminal are set respectively.

[0015] Optionally, the current charging / discharging phase is a charging phase, and the first voltage and the second voltage are the first charging voltage and the second charging voltage, respectively;

[0016] The step of setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage respectively includes:

[0017] Based on the first charging voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference.

[0018] Based on the second charging voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is the required charging voltage of the energy storage module.

[0019] Optionally, the current charging / discharging phase is a discharging phase, and the first voltage and the second voltage are the first discharge voltage and the second discharge voltage, respectively.

[0020] The step of setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage respectively includes:

[0021] Based on the first discharge voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is higher than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a second preset voltage difference.

[0022] Based on the second discharge voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is the required discharge voltage of the energy storage module.

[0023] Optionally, the current charging and discharging stage is a preparation stage, and the first voltage and the second voltage are the first preparation voltage and the second preparation voltage, respectively;

[0024] The step of setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage respectively includes:

[0025] Based on the first preparation voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference.

[0026] Based on the second preparation voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is the preset preparation voltage value.

[0027] Optionally, the preparation stage includes: a self-test stage and an insulation test stage;

[0028] If the preparation stage is the self-test stage, the second preparation voltage is the self-test voltage, and the preset preparation voltage value is the preset self-test voltage value.

[0029] If the preparation stage is the insulation detection stage, the second preparation voltage is the insulation detection voltage, and the preset preparation voltage value is the preset insulation detection voltage value.

[0030] Optionally, the preset configuration information further includes: current configuration information of the first DC terminal and current configuration information of the second DC terminal;

[0031] The method further includes:

[0032] Based on the current configuration information of the first DC terminal and the current configuration information of the second DC terminal, the current of the first DC terminal and the second DC terminal are set respectively, so that the second power conversion module performs the operation of the unidirectional mode.

[0033] Optionally, if the current charging / discharging phase is the charging phase, the current at the first DC terminal is less than the preset maximum current limit value;

[0034] If the current charging / discharging stage is the discharging stage, the current at the first DC terminal is equal to the preset maximum current limit value.

[0035] Optionally, the method further includes:

[0036] If a fault signal is received from the first power conversion module, the second power conversion module is shut down, causing the second power conversion module to switch from the unidirectional mode to the bidirectional mode.

[0037] Secondly, this application provides a bidirectional power conversion device, which includes: a control module, a first power conversion module, and a second power conversion module. The control module is connected to the second power conversion module. The AC terminal of the first power conversion module is connected to a preset AC distribution network. The DC terminal of the first power conversion module is connected to the first DC terminal of the second power conversion module. The second DC terminal of the second power conversion module is connected to the battery of an energy storage module.

[0038] The control module is used to execute any of the charging and discharging control methods described in the first aspect above.

[0039] Thirdly, embodiments of this application provide a charging system, the charging system comprising: a bidirectional power conversion device and an energy storage module; the AC terminal of the bidirectional power conversion device is connected to the preset AC distribution network; the DC terminal of the bidirectional power conversion device is connected to the battery of the energy storage module;

[0040] The bidirectional power conversion device is the bidirectional power conversion device described in the second aspect above.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] This application provides a charging and discharging control method, device, and charging system. The method acquires preset configuration information corresponding to the current charging and discharging stage. This preset configuration information includes at least: voltage configuration information of a first DC terminal. Based on the voltage configuration information of the first DC terminal, the voltage of the first DC terminal is set, causing the second power conversion module to operate in unidirectional mode. The unidirectional mode includes: charging mode and discharging mode. Therefore, by controlling the output voltage of the second power conversion module, both unidirectional operation of the second power conversion module and voltage stability of the second power conversion module are achieved, which is more conducive to protecting the safety of V2G equipment and upstream power distribution, and improving the service life of the equipment. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the structure of a bidirectional power conversion device provided in an embodiment of this application;

[0045] Figure 2 This is a schematic diagram of a charging system provided in an embodiment of this application;

[0046] Figure 3 A schematic flowchart of a charging and discharging control method provided in an embodiment of this application;

[0047] Figure 4 A flowchart illustrating a control method for the charging stage provided in an embodiment of this application;

[0048] Figure 5 A schematic flowchart illustrating a discharge stage control method provided in an embodiment of this application;

[0049] Figure 6 A schematic flowchart illustrating a discharge stage control method provided in an embodiment of this application;

[0050] Figure 7 A schematic diagram of a charge / discharge control device provided in an embodiment of this application;

[0051] Figure 8 This is a schematic diagram of a control module provided in an embodiment of this application.

[0052] Icons: 11-Control module, 12-First power conversion module, 13-Second power conversion module, 1-Bidirectional power conversion device, 2-Preset AC distribution network, 3-Energy storage module, 701-Acquisition module, 702-Setting module, 801-Processor, 802-Storage medium. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0057] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0058] Before explaining the charging and discharging control method provided in this application, a bidirectional power conversion device used in the charging and discharging control method will be explained in order to better understand the charging and discharging control method provided in this application.

[0059] Figure 1 This is a schematic diagram of a bidirectional power conversion device provided in an embodiment of this application. Figure 1 As shown, the bidirectional power conversion device includes: a control module 11, a first power conversion module 12, and a second power conversion module 13. The control module 11 is connected to the second power conversion module 13. The AC terminal of the first power conversion module 12 is connected to a preset AC distribution network. The DC terminal of the first power conversion module 12 is connected to the first DC terminal of the second power conversion module 13. The second DC terminal of the second power conversion module 13 is connected to the battery of the energy storage module.

[0060] The control module 11 is used to execute any of the charging and discharging control methods provided in this application.

[0061] Furthermore, the control module 11 is also connected to the first power conversion module 12 to obtain the DC bus voltage of the first power conversion module. The control module 11 is also connected to the BMS (Battery Management System) to obtain charging and discharging configuration information.

[0062] The first power conversion module 12 is an AC-DC converter, and the second power conversion module 13 is a DC-DC converter. The first power conversion module 12 converts AC power transmitted from a preset AC distribution network into DC power and transmits the converted DC power to the second power conversion module 13. The second power conversion module 13 transforms the DC power transmitted from the first power conversion module 12 and transmits the transformed DC power to the battery of the energy storage module. It should be noted that the above description is only a schematic diagram of one operating mode of the bidirectional power conversion device; other operating modes of the bidirectional power conversion device are described in the following embodiments.

[0063] In the above Figure 1 Based on the bidirectional power conversion device of the corresponding embodiment, this application also provides a charging system. Figure 2 This is a schematic diagram of a charging system provided in an embodiment of this application. Figure 2 As shown, the charging system includes: a bidirectional power conversion device 12 and an energy storage module 3; the AC terminal of the bidirectional power conversion device 12 is connected to a preset AC distribution network 2; the DC terminal of the bidirectional power conversion device 12 is connected to the battery of the energy storage module 3.

[0064] Among them, the bidirectional power conversion device 1 is the bidirectional power conversion device in the above embodiment.

[0065] For example, the charging system provided in this application embodiment is applied to V2G devices.

[0066] Figure 3 This is a schematic flowchart illustrating a charge / discharge control method provided in an embodiment of this application. Figure 3 As shown, this method is applied to the control module in a bidirectional power conversion device. The control module has calculation, processing, and control functions. The method includes:

[0067] S101. Obtain the preset configuration information corresponding to the current charging and discharging stage.

[0068] The preset configuration information includes at least the voltage configuration information of the first DC terminal.

[0069] The preset configuration information is determined by the BMS based on charging and discharging control requirements. The control module can control the operating mode of the bidirectional power conversion device according to the preset configuration information to achieve charging / discharging.

[0070] S102. Set the voltage of the first DC terminal according to the voltage configuration information of the first DC terminal, so that the second power conversion module operates in unidirectional mode.

[0071] The unidirectional modes include: charging mode and discharging mode.

[0072] By setting the voltage at the first DC terminal, the current flow direction of the second power conversion module can be controlled, thereby controlling the operating mode of the second power conversion module.

[0073] For example, if the current flow direction of the second power conversion module is controlled to be from the second power conversion module to the first power conversion module, then the second power conversion module operates in discharge mode. If the current flow direction of the second power conversion module is controlled to be from the first power conversion module to the second power conversion module, then the second power conversion module operates in charging mode.

[0074] By controlling the output voltage of the second power conversion module, both unidirectional operation of the second power conversion module and voltage stability are ensured. This avoids the problem of large current surges on the V2G device's neutral line and the upstream power distribution neutral line when the first power conversion module fails during V2G device charging, as the second power conversion module is still outputting power. This is more conducive to protecting the safety of the V2G device and the upstream power distribution, and further extends the equipment's lifespan.

[0075] In summary, in this embodiment, preset configuration information corresponding to the current charging and discharging stage is obtained. This preset configuration information includes at least: voltage configuration information of the first DC terminal. The voltage of the first DC terminal is set according to this voltage configuration information, causing the second power conversion module to operate in unidirectional mode. Unidirectional mode includes: charging mode and discharging mode. Therefore, by controlling the output voltage of the second power conversion module, both unidirectional operation of the second power conversion module and voltage stability are ensured, which is more conducive to protecting the safety of V2G equipment and upstream power distribution, and improving the service life of the equipment.

[0076] In the above Figure 1 Based on the corresponding embodiments, in another embodiment of this application, the voltage configuration information of the first DC terminal includes: a first voltage. The first voltage is the configured voltage value of the first DC terminal.

[0077] If the first voltage configuration is less than the DC bus voltage of the first power conversion module, the second power conversion module operates in charging mode.

[0078] If the first voltage configuration is less than the DC bus voltage of the first power conversion module, then the current direction of the bidirectional power conversion device is from the first power conversion module to the second power conversion module, and the second power conversion module operates in charging mode.

[0079] If the first voltage configuration is greater than the DC bus voltage of the first power conversion module, the second power conversion module operates in discharge mode.

[0080] If the first voltage configuration is greater than the DC bus voltage of the first power conversion module, then the current direction of the bidirectional power conversion device is from the second power conversion module to the first power conversion module, and the second power conversion module operates in discharge mode.

[0081] In summary, in this embodiment, the voltage configuration information of the first DC terminal includes: a first voltage; if the first voltage configuration is less than the DC bus voltage of the first power conversion module, the second power conversion module operates in charging mode; if the first voltage configuration is greater than the DC bus voltage of the first power conversion module, the second power conversion module operates in discharging mode. Therefore, the first voltage is controlled according to the DC bus voltage of the first power conversion module, thereby controlling the operating mode of the second power conversion module.

[0082] Based on the above embodiments, in another embodiment of this application, the preset configuration information further includes: voltage configuration information of the second DC terminal, which includes: a second voltage. The second voltage is the configured voltage value of the second DC terminal.

[0083] In S102, setting the voltage of the first DC terminal based on the voltage configuration information of the first DC terminal includes:

[0084] Based on the first voltage and the second voltage, the voltages of the first DC terminal and the second DC terminal are set respectively.

[0085] The voltage value of the first DC terminal is set to a first voltage, and the voltage value of the second DC terminal is set to a second voltage. Therefore, by setting the voltages of both the first and second DC terminals, the control accuracy is improved.

[0086] In summary, in this embodiment, the preset configuration information further includes: voltage configuration information for the second DC terminal, which includes: a second voltage; and voltage settings are performed on the first DC terminal and the second DC terminal based on the first voltage and the second voltage, respectively. Therefore, by setting the voltages for both the first and second DC terminals, control accuracy is improved.

[0087] Based on the above embodiments, this application also provides a control method for the charging stage. Figure 4This is a flowchart illustrating a control method for the charging stage provided in an embodiment of this application. Figure 4 As shown, the current charging and discharging phase is the charging phase, and the first voltage and the second voltage are the first charging voltage and the second charging voltage, respectively.

[0088] Based on the first voltage and the second voltage, the voltages of the first DC terminal and the second DC terminal are set respectively, including:

[0089] S201. Based on the first charging voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is the first preset voltage difference.

[0090] For example, the DC bus voltage of the first power conversion module is acquired in real time, and the voltage at the first DC terminal is kept lower than the DC bus voltage of the first power conversion module. This ensures that the bidirectional power conversion device operates in charging mode, but with a small voltage difference from the DC bus voltage, thus ensuring that the voltage at the first DC terminal remains stable in the event of a fault. For example, the first preset voltage difference is 30V.

[0091] S202. Based on the second charging voltage, set the voltage of the second DC terminal so that the voltage of the second DC terminal is the required charging voltage of the energy storage module.

[0092] The voltage at the second DC terminal is used for charging, and the voltage at the second DC terminal is set to the required charging voltage of the energy storage module.

[0093] In this embodiment, even if the first power conversion module suddenly fails and can no longer provide power to the second power conversion module, the second power conversion module can stabilize its bus voltage for a short time through the aforementioned voltage control method. This ensures that the second power conversion module will not experience a sudden drop in DC bus voltage, allowing for a smooth shutdown. After shutdown, the second power conversion module switches from charging mode back to bidirectional operating mode. Bidirectional operating mode means that it can switch to either charging or discharging mode.

[0094] In summary, in this embodiment, the current charging / discharging phase is the charging phase, and the first voltage and the second voltage are the first charging voltage and the second charging voltage, respectively. Based on the first charging voltage, the voltage of the first DC terminal is set so that its voltage is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference. Based on the second charging voltage, the voltage of the second DC terminal is set so that its voltage is the required charging voltage for the energy storage module. Therefore, by setting the first and second voltages, it is ensured that the voltage of the first DC terminal remains stable while achieving the charging function, and even in the event of a sudden fault, a smooth shutdown can be achieved.

[0095] Based on the above embodiments, this application also provides a method for controlling the discharge stage. Figure 5 This is a flowchart illustrating a control method for the discharge stage provided in an embodiment of this application. Figure 5 As shown, the current charging and discharging stage is the discharging stage, and the first voltage and the second voltage are the first discharge voltage and the second discharge voltage, respectively.

[0096] Based on the first voltage and the second voltage, the voltages of the first DC terminal and the second DC terminal are set respectively, including:

[0097] S301. Based on the first discharge voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is higher than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is the second preset voltage difference.

[0098] For example, the DC bus voltage of the first power conversion module is acquired in real time, and the voltage of the first DC terminal is kept higher than the DC bus voltage of the first power conversion module. This ensures that the bidirectional power conversion device operates in discharge mode, but with a relatively small voltage difference from the DC bus voltage, thus ensuring that the voltage of the first DC terminal remains stable in the event of a fault. For example, the second preset voltage difference is 15V.

[0099] S302. Based on the second discharge voltage, set the voltage of the second DC terminal so that the voltage of the second DC terminal is the required discharge voltage of the energy storage module.

[0100] To ensure that the voltage at the second DC terminal is consistent with the required discharge voltage of the energy storage module, the energy storage module can discharge smoothly.

[0101] In this embodiment, even if the first power conversion module experiences a sudden failure and there is no current fluctuation, the second power conversion module can stabilize its bus voltage for a short time through the aforementioned voltage control method, achieving a smooth shutdown. After shutdown, the second power conversion module switches back from discharge mode to bidirectional operating mode.

[0102] In summary, in this embodiment, the current charging / discharging stage is the discharging stage, and the first voltage and the second voltage are the first discharge voltage and the second discharge voltage, respectively. Based on the first discharge voltage, the voltage of the first DC terminal is set so that its voltage is higher than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a second preset voltage difference. Based on the second discharge voltage, the voltage of the second DC terminal is set so that its voltage is the required discharge voltage of the energy storage module. Therefore, by setting the first and second voltages, it is ensured that the voltage of the first DC terminal remains stable while achieving the discharge function, and even in the event of a sudden fault, a smooth shutdown can be achieved.

[0103] Based on the above embodiments, this application also provides a control method for the preparation stage. Figure 6 This is a flowchart illustrating a control method for the discharge stage provided in an embodiment of this application. Figure 6 As shown, the current charging and discharging stage is the preparation stage, and the first voltage and the second voltage are the first preparation voltage and the second preparation voltage, respectively.

[0104] Based on the first voltage and the second voltage, the voltages of the first DC terminal and the second DC terminal are set respectively, including:

[0105] S401. Based on the first preparation voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is the first preset voltage difference.

[0106] For example, the DC bus voltage of the first power conversion module is acquired in real time, and the voltage of the first DC terminal is kept higher than the DC bus voltage of the first power conversion module. This ensures that the current flow of the bidirectional power conversion device is from the second DC terminal to the first DC terminal, but the voltage difference with the DC bus voltage is relatively small, so as to ensure that the voltage of the first DC terminal remains stable in the event of a fault.

[0107] S402. Based on the second preparation voltage, set the voltage of the second DC terminal so that the voltage of the second DC terminal is the preset preparation voltage value.

[0108] For example, the preset preparation voltage can be 300V to enable power-on with a smaller preparation voltage.

[0109] In this embodiment, if the first power conversion module suddenly fails, the second power conversion module can stabilize the bus voltage of the second power conversion module in a short time through the above-mentioned voltage control method, without large current surge, thereby achieving a smooth shutdown.

[0110] In summary, in this embodiment, the current charging / discharging stage is the preparation stage, and the first voltage and the second voltage are the first preparation voltage and the second preparation voltage, respectively. Based on the first preparation voltage, the voltage of the first DC terminal is set so that its voltage is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference. Based on the second preparation voltage, the voltage of the second DC terminal is set so that its voltage is the preset preparation voltage value. Therefore, by setting the first and second voltages, it is ensured that the voltage of the first DC terminal remains stable while achieving the preparation function, and even in the event of a sudden fault, a smooth shutdown can be achieved.

[0111] In another embodiment of this application, the preparation stage includes: a self-test stage and an insulation test stage.

[0112] If the preparation stage is a self-test stage, the second preparation voltage is the self-test voltage, and the preset preparation voltage value is the preset self-test voltage value.

[0113] If the preparation stage is the insulation detection stage, the second preparation voltage is the insulation detection voltage, and the preset preparation voltage value is the preset insulation detection voltage value.

[0114] In another embodiment of this application, the preset configuration information further includes: current configuration information of the first DC terminal and current configuration information of the second DC terminal.

[0115] The method also includes:

[0116] Based on the current configuration information of the first DC terminal and the current configuration information of the second DC terminal, the current of the first DC terminal and the second DC terminal are set respectively, so that the second power conversion module performs unidirectional mode operation.

[0117] Add current configuration information for the first DC terminal and the second DC terminal to control the current and prevent overcurrent when the second power conversion module is working.

[0118] In another embodiment of this application, if the current charging / discharging stage is the charging stage, the current at the first DC terminal is less than the preset maximum current limit value.

[0119] If the current charging / discharging phase is the discharging phase, the current at the first DC terminal is equal to the preset maximum current limit value.

[0120] The current at the first DC terminal is controlled by referencing a preset maximum current limit value to prevent overcurrent.

[0121] In another embodiment of this application, the method further includes:

[0122] If a fault signal is received from the first power conversion module, the second power conversion module is shut down, switching it from unidirectional mode to bidirectional mode.

[0123] With the voltage control method described above, regardless of the operating stage, if the first power conversion module suddenly fails, the second power conversion module can stabilize the bus voltage of the second power conversion module in a short time, thereby achieving a smooth shutdown.

[0124] In summary, in this embodiment, if a fault signal is received from the first power conversion module, the second power conversion module is shut down, switching it from unidirectional to bidirectional mode. This ensures a smooth shutdown of the second power conversion module in the event of a sudden failure in the first power conversion module.

[0125] The following describes a charge / discharge control device, equipment, and storage medium provided in this application for implementation. The specific implementation process and technical effects are described above and will not be repeated below.

[0126] Figure 7 This is a schematic diagram of a charge / discharge control device provided in an embodiment of this application, as shown below. Figure 7 As shown, the device includes:

[0127] The acquisition module 701 is used to acquire the preset configuration information corresponding to the current charging and discharging stage. The preset configuration information includes at least the voltage configuration information of the first DC terminal.

[0128] The setting module 702 is used to set the voltage of the first DC terminal according to the voltage configuration information of the first DC terminal, so that the second power conversion module operates in unidirectional mode, including charging mode and discharging mode.

[0129] Furthermore, the setting module 702 is also used to configure the voltage information of the first DC terminal, including: a first voltage; if the first voltage configuration is less than the DC bus voltage of the first power conversion module, then the second power conversion module operates in charging mode; if the first voltage configuration is greater than the DC bus voltage of the first power conversion module, then the second power conversion module operates in discharging mode.

[0130] Furthermore, the setting module 702, specifically used for preset configuration information, also includes: voltage configuration information of the second DC terminal, the voltage configuration information of the second DC terminal including: second voltage; and setting the voltage of the first DC terminal and the second DC terminal respectively according to the first voltage and the second voltage.

[0131] Furthermore, the setting module 702 is specifically used to set the current charging and discharging stage as the charging stage, where the first voltage and the second voltage are the first charging voltage and the second charging voltage, respectively; based on the first charging voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference; based on the second charging voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is lower than the required charging voltage of the energy storage module.

[0132] Furthermore, the setting module 702 is specifically used so that the current charging and discharging stage is the discharging stage, and the first voltage and the second voltage are the first discharge voltage and the second discharge voltage, respectively; according to the first discharge voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is higher than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is the second preset voltage difference; according to the second discharge voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is the required discharge voltage of the energy storage module.

[0133] Furthermore, the setting module 702 is specifically used for the current charging and discharging stage to be a preparation stage, where the first voltage and the second voltage are respectively the first preparation voltage and the second preparation voltage; according to the first preparation voltage, the voltage of the first DC terminal is set so that the voltage of the first DC terminal is lower than the DC bus voltage of the first power conversion module, and the voltage difference between the first DC terminal and the DC bus voltage is a first preset voltage difference; according to the second preparation voltage, the voltage of the second DC terminal is set so that the voltage of the second DC terminal is a preset preparation voltage value.

[0134] Furthermore, the setting module 702 is specifically used for the preparation stage, which includes: a self-test stage and an insulation detection stage; if the preparation stage is a self-test stage, the second preparation voltage is the self-test voltage, and the preset preparation voltage value is the preset self-test voltage value; if the preparation stage is an insulation detection stage, the second preparation voltage is the insulation detection voltage, and the preset preparation voltage value is the preset insulation detection voltage value.

[0135] Furthermore, the setting module 702, specifically used for preset configuration information, also includes: current configuration information of the first DC terminal and current configuration information of the second DC terminal; based on the current configuration information of the first DC terminal and the current configuration information of the second DC terminal, the current of the first DC terminal and the second DC terminal are set respectively, so that the second power conversion module performs unidirectional mode operation.

[0136] Furthermore, the setting module 702 is specifically used to ensure that if the current charging / discharging stage is the charging stage, the current at the first DC terminal is less than the preset maximum current limit value; and if the current charging / discharging stage is the discharging stage, the current at the first DC terminal is equal to the preset maximum current limit value.

[0137] Furthermore, the setting module 702 is specifically used to shut down the second power conversion module if a fault signal is received from the first power conversion module, thereby switching the second power conversion module from unidirectional mode to bidirectional mode.

[0138] Figure 8 This is a schematic diagram of a control module provided in an embodiment of this application. The control module may be a device with computing processing capabilities.

[0139] The control module includes a processor 801 and a storage medium 802. The processor 801 and the storage medium 802 are connected via a bus.

[0140] Storage medium 802 is used to store programs, and processor 801 calls the programs stored in storage medium 802 to execute the above method embodiments. The specific implementation and technical effects are similar, and will not be described in detail here.

[0141] Optionally, the present invention also provides a storage medium including a program, which, when executed by a processor, is used to perform the above-described method embodiments. In the several embodiments provided by the present invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for example, the division of units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0142] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0143] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0144] The integrated units implemented as software functional units described above can be stored in a storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. 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.

Claims

1. A charge and discharge control method characterized by comprising: The application relates to a control module applied to a bidirectional power conversion device, wherein the bidirectional power conversion device further comprises a first power conversion module and a second power conversion module; the control module is connected to the second power conversion module; an alternating current end of the first power conversion module is connected to a preset alternating current power distribution network; a direct current end of the first power conversion module is connected to a first direct current end of the second power conversion module; a second direct current end of the second power conversion module is connected to a battery of an energy storage module; and the method comprises the following steps: obtaining preset configuration information corresponding to a current charging and discharging stage, wherein the preset configuration information at least comprises voltage configuration information of the first direct current end, and the voltage configuration information of the first direct current end comprises a first voltage, which is a configuration voltage value of the first direct current end; performing voltage setting on the first direct current end according to the voltage configuration information of the first direct current end, so as to control the current flow direction of the bidirectional power conversion device, and make the second power conversion module work in a unidirectional mode, wherein the unidirectional mode comprises a charging mode and a discharging mode; the preset configuration information further comprises voltage configuration information of the second direct current end, and the voltage configuration information of the second direct current end comprises a second voltage; and performing voltage setting on the first direct current end and the second direct current end respectively according to the first voltage and the second voltage.

2. The method of claim 1, wherein, the voltage setting on the first direct current end according to the voltage configuration information of the first direct current end, so as to control the current flow direction of the bidirectional power conversion device, and make the second power conversion module work in a unidirectional mode, comprises: if the first voltage configuration is less than the direct current bus voltage of the first power conversion module, the second power conversion module works in the charging mode; if the first voltage configuration is greater than the direct current bus voltage of the first power conversion module, the second power conversion module works in the discharging mode.

3. The method of claim 1, wherein, the current charging and discharging stage is a charging stage, and the first voltage and the second voltage are respectively a first charging voltage and a second charging voltage; the voltage setting on the first direct current end and the second direct current end respectively according to the first voltage and the second voltage, comprises: performing voltage setting on the first direct current end according to the first charging voltage, so that the voltage of the first direct current end is lower than the direct current bus voltage of the first power conversion module, and the voltage difference between the direct current bus voltage and the voltage of the first direct current end is a first preset voltage difference; performing voltage setting on the second direct current end according to the second charging voltage, so that the voltage of the second direct current end is a required charging voltage of the energy storage module.

4. The method of claim 1, wherein, the current charging and discharging stage is a discharging stage, and the first voltage and the second voltage are respectively a first discharging voltage and a second discharging voltage; the voltage setting on the first direct current end and the second direct current end respectively according to the first voltage and the second voltage, comprises: According to the first discharge voltage, the first DC end is set to have a voltage higher than a DC bus voltage of the first power conversion module by a second preset voltage difference; According to the second discharge voltage, the second DC end is set to have a voltage as a required discharge voltage of the energy storage module.

5. The method of claim 1, wherein, The current charging and discharging phase is a preparation phase, and the first voltage and the second voltage are a first preparation voltage and a second preparation voltage, respectively. The method further comprises: According to the first preparation voltage, the first DC end is set to have a voltage lower than the DC bus voltage of the first power conversion module by a first preset voltage difference; According to the second preparation voltage, the second DC end is set to have a voltage as a preset preparation voltage value.

6. The method of claim 5, wherein, The preparation phase comprises a self-check phase and an insulation detection phase. If the preparation phase is the self-check phase, the second preparation voltage is a self-check voltage, and the preset preparation voltage value is a preset self-check voltage value. If the preparation phase is the insulation detection phase, the second preparation voltage is an insulation detection voltage, and the preset preparation voltage value is a preset insulation detection voltage value.

7. The method of claim 1, wherein, The preset configuration information further comprises current configuration information of the first DC end and current configuration information of the second DC end. The method further comprises: According to the current configuration information of the first DC end and the current configuration information of the second DC end, the first DC end and the second DC end are respectively set to have currents, so that the second power conversion module performs the operation in the unidirectional mode.

8. The method of claim 7, wherein, If the current charging and discharging phase is a charging phase, the current of the first DC end is less than a preset maximum current limit value. If the current charging and discharging phase is a discharging phase, the current of the first DC end is equal to the preset maximum current limit value.

9. The method of claim 8, wherein, The method further comprises: If the fault signal of the first power conversion module is received, the second power conversion module is turned off, so that the second power conversion module is switched from the unidirectional mode to a bidirectional mode.

10. A bidirectional power conversion device, characterized by, The bidirectional power conversion device comprises a control module, a first power conversion module, and a second power conversion module. The control module is connected to the second power conversion module. An AC end of the first power conversion module is connected to a preset AC power distribution network. A DC end of the first power conversion module is connected to a first DC end of the second power conversion module. A second DC end of the second power conversion module is connected to a battery of an energy storage module. The control module is configured to perform the charging and discharging control method according to any one of claims 1-9.

11. A charging system, characterized by The charging system comprises a bidirectional power conversion device and an energy storage module. An AC end of the bidirectional power conversion device is connected to a preset AC power distribution network. A DC end of the bidirectional power conversion device is connected to a battery of the energy storage module. The bidirectional power conversion device is the bidirectional power conversion device in claim 10. The bidirectional power conversion device is the bidirectional power conversion device in claim 10.

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