Charging and discharging control method and device and charging system

Abstract

The invention 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 end; and according to the voltage configuration information of the first DC end, voltage setting is carried out on the first DC end, so that the second power conversion module works in a one-way mode, and the one-way mode comprises a charging mode and a discharging mode. Therefore, by controlling the output voltage of the second power conversion module, the second power conversion module can work in a one-way mode, and the voltage stability of the second power conversion module is ensured, so that the V2G equipment and the safety of superior power distribution are protected, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a charging and discharging control method, device and charging system. Background Art

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

[0003] V2G technology is based on the interaction between electric vehicles and the power grid to achieve a two-way flow of energy, using a large number of electric vehicle batteries as a buffer zone with the renewable energy of the power grid. Through V2G, when the power grid load is low and the electricity price is low, the battery needs to be charged and the electric vehicle stores excess energy. Conversely, the electric vehicle feeds electricity to the power grid through the V2G device, which can also create income for electric vehicle users.

[0004] In existing V2G products, in order to apply to more scenarios (such as vehicle-grid interaction 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. Then, during the charging process, when the PCS source fails suddenly, in order to prevent the relay from sticking, the blocking wave + judging the relay current method is often used as the shutdown condition (the relay changes from closed to open). During the V2G charging operation, because the power is maintained during the charging process, the bidirectional DCDC (Direct Current to Direct Current) module has not been shut down in time, the bidirectional ACDC can only block the wave and the relay cannot be disconnected, causing the bidirectional ACDC to work in an uncontrolled rectification state. Due to the three-phase four-wire topology, the neutral line current is 3 times that of the phase line, which will cause the equipment to exceed the operating current and the upper-level power distribution design specifications. If not handled in time, it will cause equipment damage and trigger the upper-level power distribution to trip. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies in the above-mentioned prior art and provide a charge and discharge control method, device and charging system to solve the problems in the prior art that the equipment is easily damaged by current shocks.

[0006] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0007] In a first aspect, an embodiment of the present application provides a charge and discharge control method, which is applied to a control module in a bidirectional power conversion device, wherein the bidirectional power conversion device further includes: a first power conversion module and a second power conversion module, wherein the control module is connected to the second power conversion module, wherein 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, and a second DC end of the second power conversion module is connected to a battery of an energy storage module, wherein the method includes:

[0008] Acquire preset configuration information corresponding to the current charging and discharging stage, wherein the preset configuration information at least includes: 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 works in a unidirectional mode, and the unidirectional mode includes: a charging mode and a 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, 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, 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, the voltage configuration information of the second DC terminal includes: a second voltage; and setting the voltage of the first DC terminal according to the voltage configuration information of the first DC terminal includes:

[0014] The voltages of the first DC terminal and the second DC terminal are set according to the first voltage and the second voltage.

[0015] Optionally, the current charge and discharge stage is a charging stage, and the first voltage and the second voltage are a first charging voltage and a second charging voltage respectively;

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

[0017] According to the first charging voltage, setting the voltage of the first DC terminal 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] The voltage of the second DC terminal is set according to the second charging voltage so that the voltage of the second DC terminal is the required charging voltage of the energy storage module.

[0019] Optionally, the current charging and discharging stage is a discharging stage, and the first voltage and the second voltage are a first discharging voltage and a second discharging voltage respectively;

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

[0021] According to the first discharge voltage, setting the voltage of the first DC terminal 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] The voltage of the second DC terminal is set according to the second discharge voltage 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 a first preparation voltage and a second preparation voltage respectively;

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

[0025] According to the first preparation voltage, setting the voltage of the first DC terminal 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] 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.

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

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

[0029] If the preparation stage is the insulation detection stage, the second preparation voltage is an insulation detection voltage, and the preset preparation voltage value is a 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 comprises:

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

[0033] Optionally, if the current charging and discharging stage is a charging stage, the current of the first DC terminal is less than a preset maximum current limit value;

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

[0035] Optionally, the method further comprises:

[0036] If a 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 switches from the unidirectional mode to the bidirectional mode.

[0037] In a second aspect, an embodiment of the present application provides a bidirectional power conversion device, the bidirectional power conversion device comprising: 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 end of the first power conversion module is connected to a preset AC power distribution network, the DC end of the first power conversion module is connected to a first DC end of the second power conversion module, and the second DC end of the second power conversion module is connected to a battery of an energy storage module;

[0038] The control module is used to execute the charge and discharge control method described in any one of the first aspects above.

[0039] In a third aspect, an embodiment of the present application provides a charging system, the charging system comprising: a bidirectional power conversion device and an energy storage module; the AC end of the bidirectional power conversion device is connected to the preset AC distribution network; the DC end of the bidirectional power conversion device is connected to the battery of the energy storage module;

[0040] Wherein, 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] The present application provides a charge and discharge control method, device and charging system. The method obtains preset configuration information corresponding to the current charge and discharge stage, and the preset configuration information at least includes: voltage configuration information of the first DC terminal; 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 works in a unidirectional mode, and the unidirectional mode includes: charging mode and discharging mode. Therefore, by controlling the output voltage of the second power conversion module, the second power conversion module is realized to work in a unidirectional mode, and the voltage stability of the second power conversion module is also ensured, which is more conducive to protecting the safety of V2G equipment and upper power distribution, and improving the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

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

[0045] Figure 2 A schematic diagram of the structure of a charging system provided in an embodiment of the present application;

[0046] Figure 3 A flow chart of a charge and discharge control method provided in an embodiment of the present application;

[0047] Figure 4 A flow chart of a control method for a charging stage provided in an embodiment of the present application;

[0048] Figure 5 A flow chart of a control method for a discharge phase provided in an embodiment of the present application;

[0049] Figure 6 A flow chart of a control method for a discharge phase provided in an embodiment of the present application;

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

[0051] Figure 8 A schematic diagram of a control module provided in an embodiment of the present 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 DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0056] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0057] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0058] Before explaining a charge and discharge control method provided in the present application, a bidirectional power conversion device applied by the charge and discharge control method is first explained to facilitate a better understanding of the charge and discharge control method provided in the present application.

[0059] Figure 1 This is a schematic diagram of the structure of a bidirectional power conversion device provided in an embodiment of the present 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 end of the first power conversion module 12 is connected to a preset AC power distribution network, the DC end of the first power conversion module 12 is connected to a first DC end of the second power conversion module 13, and the second DC end 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 one of the charge and discharge control methods provided in this application.

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

[0062] Among them, 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 is used to convert the AC power transmitted by the preset AC distribution network into DC power, and transmit the converted DC power to the second power conversion module 13. The second power conversion module 13 is used to transform the DC power transmitted by the first power conversion module 12, and transmit the transformed DC power to the battery of the energy storage module. It should be noted that the above description is only a principle illustration of one working mode of the bidirectional power conversion device, and other working 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, the embodiment of the present application also provides a charging system. Figure 2 This is a schematic diagram of the structure of a charging system provided in an embodiment of the present application. Figure 2 As shown, the charging system includes: a bidirectional power conversion device 12 and an energy storage module 3; the AC end of the bidirectional power conversion device 1 is connected to a preset AC distribution network 2; and the DC end of the bidirectional power conversion device 1 is connected to the battery of the energy storage module 3.

[0064] The bidirectional power conversion device 1 is the bidirectional power conversion device in the above-mentioned embodiment.

[0065] For example, the charging system provided in the embodiments of the present application is applied to a V2G device.

[0066] Figure 3 A flow chart of a charge and discharge control method provided in an embodiment of the present application. Figure 3 As shown, the method is applied to a control module in a bidirectional power conversion device, the control module has a calculation and processing control function, and the method includes:

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

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

[0069] The preset configuration information is determined by the BMS according to the charge and discharge control requirements. The control module can control the working mode of the bidirectional power conversion device according to the preset configuration information to achieve charge / discharge.

[0070] S102 . Setting 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 a unidirectional mode.

[0071] Among them, the unidirectional mode includes: charging mode and discharging mode.

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

[0074] By controlling the output voltage of the second power conversion module, the second power conversion module is operated in a unidirectional mode and the voltage stability of the second power conversion module is ensured. Thus, when the first power conversion module of the V2G device suddenly fails during charging, the problem of large current impact on the neutral line of the V2G device and the neutral line of the upper power distribution is avoided because the second power conversion module is still outputting power. This is more conducive to protecting the safety of the V2G device and the upper power distribution, and further improving the service life of the equipment.

[0075] In summary, in this embodiment, the preset configuration information corresponding to the current charging and discharging stage is obtained, and the preset configuration information at least includes: the voltage configuration information of the first DC terminal; 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 works in a unidirectional mode, and the unidirectional mode includes: charging mode and discharging mode. Therefore, by controlling the output voltage of the second power conversion module, the second power conversion module is realized to work in a unidirectional mode, and the voltage stability of the second power conversion module is also ensured, which is more conducive to protecting the safety of V2G equipment and upper power distribution, and improving the service life of the equipment.

[0076] In the above Figure 1 On the basis of the corresponding embodiment, in another embodiment of the present application, the voltage configuration information of the first DC terminal includes: a first voltage. The first voltage is a configuration 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 the charging mode.

[0078] If the first voltage configuration is less than the DC bus voltage of the first power conversion module, 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 the 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 a discharge mode.

[0080] If the first voltage configuration is greater than the DC bus voltage of the first power conversion module, 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 the 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 a 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 a discharging mode. Thus, 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 embodiment, in another embodiment of the present application, the preset configuration information further includes: voltage configuration information of the second DC terminal, and the voltage configuration information of the second DC terminal includes: a second voltage. The second voltage is a configuration voltage value of the second DC terminal.

[0083] In S102, the voltage of the first DC terminal is set according to the voltage configuration information of the first DC terminal, including:

[0084] The voltages of the first DC terminal and the second DC terminal are set according to the first voltage and the second voltage.

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

[0086] In summary, in this embodiment, the preset configuration information further includes: voltage configuration information of the second DC terminal, and the voltage configuration information of the second DC terminal includes: the second voltage; and voltage settings are performed on the first DC terminal and the second DC terminal respectively according to the first voltage and the second voltage. Thus, by setting voltages on both the first DC terminal and the second DC terminal, the control accuracy is improved.

[0087] Based on the above embodiments, the embodiments of the present application also provide a control method for the charging stage. Figure 4A flow chart of a control method for a charging stage provided in an embodiment of the present application. Figure 4 As shown, the current charge and discharge stage is the charging stage, and the first voltage and the second voltage are the first charging voltage and the second charging voltage respectively.

[0088] According to the first voltage and the second voltage, the voltage of the first DC terminal and the second DC terminal are set respectively, including:

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

[0090] For example, the DC bus voltage of the first power conversion module is obtained in real time, and the voltage of the first DC terminal is kept lower than the DC bus voltage of the first power conversion module, so that the working mode of the bidirectional power conversion device is in the charging mode, but the voltage difference with the DC bus voltage is relatively small, ensuring that the voltage of the first DC terminal is kept stable when a fault occurs. For example, the first preset voltage difference is 30V.

[0091] S202: Setting the voltage of the second DC terminal according to the second charging voltage so that the voltage of the second DC terminal is the required charging voltage of the energy storage module.

[0092] The voltage of the second DC terminal is used for charging, and the voltage of 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 the bus voltage of the second power conversion module in a short time through the above-mentioned voltage control method, ensuring that the second power conversion module will not drop due to the instantaneous drop of the DC bus, and can achieve smooth shutdown. After shutdown, the second power conversion module switches from the charging mode to the bidirectional working mode. Among them, the bidirectional working mode means that it can be switched to both the charging mode and the discharging mode.

[0094] In summary, in this embodiment, the current charge-discharge stage is the charging stage, and the first voltage and the second voltage are the first charging voltage and the second charging voltage respectively; according to 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 with the DC bus voltage is the first preset voltage difference; according to 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. Thus, by setting the first voltage and the second voltage, it is ensured that the voltage of the first DC terminal is always stable under the premise of realizing the charging function, and even if a sudden fault occurs, a smooth shutdown can be achieved.

[0095] Based on the above embodiments, the embodiments of the present application also provide a control method for the discharge phase. Figure 5 A flow chart of a control method for the discharge phase provided in an embodiment of the present application. Figure 5 As shown, the current charging and discharging stage is the discharging stage, and the first voltage and the second voltage are respectively the first discharging voltage and the second discharging voltage.

[0096] According to the first voltage and the second voltage, the voltage of the first DC terminal and the second DC terminal are set respectively, including:

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

[0098] For example, the DC bus voltage of the first power conversion module is obtained 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, so that the working mode of the bidirectional power conversion device is in the discharge mode, but the voltage difference with the DC bus voltage is relatively small, ensuring that the voltage of the first DC terminal is kept stable when a fault occurs. For example, the second preset voltage difference is 15V.

[0099] S302: Setting the voltage of the second DC terminal according to the second discharge voltage so that the voltage of the second DC terminal is the required discharge voltage of the energy storage module.

[0100] The voltage at the second DC terminal is kept consistent with the required discharge voltage of the energy storage module to ensure smooth discharge of the energy storage module.

[0101] In this embodiment, even if the first power conversion module fails suddenly and there is no current fluctuation, the second power conversion module can stabilize the bus voltage of the second power conversion module in a short time through the above voltage control method to achieve smooth shutdown. After shutdown, the second power conversion module switches from the discharge mode to the bidirectional working mode.

[0102] In summary, in this embodiment, the current charging and discharging stage is the discharging stage, and the first voltage and the second voltage are the first discharging voltage and the second discharging voltage respectively; according to the first discharging 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 with the DC bus voltage is the second preset voltage difference; according to the second discharging 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. Thus, by setting the first voltage and the second voltage, it is ensured that the voltage of the first DC terminal is always stable under the premise of realizing the discharging function, and a smooth shutdown can be achieved even in case of sudden failure.

[0103] Based on the above embodiments, the embodiments of the present application also provide a control method for the preparation stage. Figure 6 A flow chart of a control method for the discharge phase provided in an embodiment of the present application. Figure 6 As shown, the current charging and discharging stage is a preparation stage, and the first voltage and the second voltage are respectively a first preparation voltage and a second preparation voltage.

[0104] According to the first voltage and the second voltage, the voltage of the first DC terminal and the second DC terminal are set respectively, including:

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

[0106] For example, the DC bus voltage of the first power conversion module is obtained 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, so that the current of the bidirectional power conversion device flows from the second DC terminal to the first DC terminal, but the voltage difference with the DC bus voltage is relatively small, ensuring that the voltage of the first DC terminal is kept stable when a fault occurs.

[0107] S402: Setting the voltage of the second DC terminal according to the second preparation voltage so that the voltage of the second DC terminal is a preset preparation voltage value.

[0108] For example, the preset preparation voltage value may be 300V, and the power-on is achieved with a smaller preparation voltage.

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

[0110] In summary, in this embodiment, 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; 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 with the DC bus voltage is the 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 the preset preparation voltage value. Thus, by setting the first voltage and the second voltage, it is ensured that the voltage of the first DC terminal is always stable under the premise of realizing the preparation function, and even if a sudden fault occurs, a smooth shutdown can be achieved.

[0111] In another embodiment of the present 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 a self-test voltage, and the preset preparation voltage value is a preset self-test voltage value.

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

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

[0115] The method further includes:

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

[0117] The current configuration information of the first DC terminal and the current configuration information of the second DC terminal are added to control the current and avoid overcurrent when the second power conversion module is working.

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

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

[0120] By using the preset maximum current limit value as a reference, the current at the first DC terminal is controlled to avoid overcurrent.

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

[0122] If a 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 the bidirectional mode.

[0123] Through the above voltage control method, no matter in which working stage, if the first power conversion module fails suddenly, the second power conversion module can stabilize the bus voltage of the second power conversion module in a short time, thereby achieving smooth shutdown.

[0124] In summary, in this embodiment, if a 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 the bidirectional mode. Thus, when the first power conversion module suddenly fails, the second power conversion module is smoothly shut down.

[0125] The following is a description of a charge and discharge control device, equipment, storage medium, etc. provided by the present application for execution. The specific implementation process and technical effects are described above and will not be repeated below.

[0126] Figure 7 A schematic diagram of a charge and discharge control device provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, the device comprises:

[0127] The acquisition module 701 is used to acquire preset configuration information corresponding to the current charging and discharging stage, and the preset configuration information at least includes: 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 works in a unidirectional mode, and the unidirectional mode includes: a charging mode and a discharging mode.

[0129] Furthermore, the setting module 702 is also used for the voltage configuration information of the first DC end, including: 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 a 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 a discharging mode.

[0130] Furthermore, the setting module 702 is specifically used to preset the configuration information further including: voltage configuration information of the second DC terminal, the voltage configuration information of the second DC terminal including: the 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 for the current charge and discharge stage to be the charging stage, the first voltage and the second voltage are respectively the first charging voltage and the second charging voltage; according to 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 with the DC bus voltage is a first preset voltage difference; according to 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 for the current charging and discharging stage to be the discharging stage, the first voltage and the second voltage are respectively the first discharging voltage and the second discharging voltage; according to the first discharging 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 with the DC bus voltage is the second preset voltage difference; according to the second discharging 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 the preparation stage, 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 with 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 the preset preparation voltage value.

[0134] Furthermore, module 702 is set up, which is specifically used for the preparation stage including: a self-test stage and an insulation detection stage; 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; 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.

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

[0136] Furthermore, module 702 is set, which is specifically used to, if the current charging and discharging stage is the charging stage, the current of the first DC terminal is less than the preset maximum current limit value; if the current charging and discharging stage is the discharging stage, the current of the first DC terminal is equal to the preset maximum current limit value.

[0137] Furthermore, a module 702 is provided, which is specifically configured to shut down the second power conversion module if a fault signal of the first power conversion module is received, so that the second power conversion module switches from the unidirectional mode to the bidirectional mode.

[0138] Figure 8 A schematic diagram of a control module provided in an embodiment of the present application, the control module may be a device with computing and processing functions.

[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] The storage medium 802 is used to store programs, and the processor 801 calls the programs stored in the storage medium 802 to execute the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0141] Optionally, the present invention also provides a storage medium, including a program, which is used to execute the above-mentioned method embodiment when executed by a processor. In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

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

[0143] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0144] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to perform some steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, abbreviated: ROM), random access memory (English: Random Access Memory, abbreviated: RAM), disk or optical disk and other media that can store program codes.

Claims

1. A charge and discharge control method, characterized in that: A control module applied to a bidirectional power conversion device, the bidirectional power conversion device further comprising: a first power conversion module and a second power conversion module, the control module being connected to the second power conversion module, the AC end of the first power conversion module being connected to a preset AC power distribution network, the DC end of the first power conversion module being connected to a first DC end of the second power conversion module, and the second DC end of the second power conversion module being connected to a battery of an energy storage module, the method comprising: Acquire preset configuration information corresponding to the current charging and discharging stage, wherein the preset configuration information at least includes: voltage configuration information of the first DC terminal; 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 works in a unidirectional mode, and the unidirectional mode includes: a charging mode and a discharging mode.

2. The method according to claim 1, characterized in that 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 the 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 the discharge mode.

3. The method according to claim 2, characterized in that The preset configuration information further includes: voltage configuration information of the second DC terminal, the voltage configuration information of the second DC terminal includes: a second voltage; and setting the voltage of the first DC terminal according to the voltage configuration information of the first DC terminal includes: The voltages of the first DC terminal and the second DC terminal are set according to the first voltage and the second voltage.

4. The method according to claim 3, characterized in that 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 step of respectively setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage includes: According to the first charging voltage, setting the voltage of the first DC terminal 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; The voltage of the second DC terminal is set according to the second charging voltage so that the voltage of the second DC terminal is the required charging voltage of the energy storage module.

5. The method according to claim 3, characterized in that: 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 step of respectively setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage includes: According to the first discharge voltage, setting the voltage of the first DC terminal 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; The voltage of the second DC terminal is set according to the second discharge voltage so that the voltage of the second DC terminal is the required discharge voltage of the energy storage module.

6. The method according to claim 3, characterized in that The current charging and discharging stage is a preparation stage, and the first voltage and the second voltage are respectively a first preparation voltage and a second preparation voltage; The step of respectively setting the voltages of the first DC terminal and the second DC terminal according to the first voltage and the second voltage includes: According to the first preparation voltage, setting the voltage of the first DC terminal 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.

7. The method according to claim 6, characterized in that The preparation stage includes: a self-test stage and an insulation test stage; If the preparation stage is the self-test stage, the second preparation voltage is a self-test voltage, and the preset preparation voltage value is a preset self-test voltage value; If the preparation stage is the insulation detection stage, the second preparation voltage is an insulation detection voltage, and the preset preparation voltage value is a preset insulation detection voltage value.

8. The method according to claim 1, characterized in that The preset configuration information also includes: current configuration information of the first DC terminal, and current configuration information of the second DC terminal; The method further comprises: According to the current configuration information of the first DC terminal and the current configuration information of the second DC terminal, currents of the first DC terminal and the second DC terminal are set respectively, so that the second power conversion module performs the operation in the unidirectional mode.

9. The method according to claim 8, characterized in that If the current charging and discharging stage is a charging stage, the current at the first DC terminal is less than a preset maximum current limit value; If the current charging and discharging stage is a discharging stage, the current of the first DC terminal is equal to a preset maximum current limit value.

10. The method according to claim 9, characterized in that The method further comprises: If a 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 switches from the unidirectional mode to the bidirectional mode.

11. A bidirectional power conversion device, characterized in that: The bidirectional power conversion device comprises: a control module, a first power conversion module, and a second power conversion module, wherein 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, and a second DC end of the second power conversion module is connected to a battery of an energy storage module; The control module is used to execute the charge and discharge control method described in any one of claims 1 to 10.

12. A charging system, characterized in that: The charging system comprises: a bidirectional power conversion device and an energy storage module; the AC end of the bidirectional power conversion device is connected to a preset AC power distribution network; the DC end of the bidirectional power conversion device is connected to the battery of the energy storage module; Wherein, the bidirectional power conversion device is the bidirectional power conversion device described in claim 11 above.

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