Optical storage converter and grid-connected and off-grid switching device, system and equipment thereof

Abstract

The utility model relates to an optical storage converter and a grid-connected and off-grid switching device, system and equipment thereof, and the grid-connected and off-grid switching device comprises an electric signal detection unit, a gear switching trigger unit, a grid-connected and off-grid gear switching switch and a control unit, and the control unit outputs a gear switching trigger signal corresponding to an electric signal. And a power-off protection mechanism of the optical storage converter is triggered under a power-off condition, so that the fault problem caused by sudden power-off due to a power grid fault in the prior art is solved; and outputting a control signal corresponding to the gear switching trigger signal through a gear switching trigger unit according to the gear switching trigger signal, so as to perform grid-connected and off-grid state switching on the optical storage converter through a grid-connected and off-grid gear switching switch according to the control signal, thereby realizing automatic switching of the grid-connected and off-grid states. Therefore, the problem caused by the fact that two independent interfaces are adopted to achieve grid-connected and off-grid separated design in the prior art is solved, and the operation stability and safety of the optical storage converter can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic energy storage, and particularly relates to a photovoltaic energy storage converter, a grid-connected and off-grid switching device, system and equipment thereof. BACKGROUND

[0002] With the rapid development of photovoltaic energy storage technology, photovoltaic energy storage integrated products are widely applied. Taking a micro photovoltaic energy storage system as an example, the micro photovoltaic energy storage system, as a mobile energy storage power supply system, has the characteristics of flexibility and portability, and is applied to various life scenes.

[0003] Specifically, the photovoltaic energy storage system power supply can meet the power supply demand of most household appliances, and the photovoltaic energy storage system uses solar clean energy as the highest priority criterion and maximally utilizes clean energy, which has good research and application value. At present, the grid-connected and off-grid alternating current interfaces of the photovoltaic energy storage system usually adopt two independent interfaces to realize separate design of grid connection and off-grid. However, since the grid-connected and off-grid alternating current interfaces of the photovoltaic energy storage system adopt two independent interfaces to realize separate design of grid connection and off-grid, in the case of sudden power failure of the power grid, the photovoltaic energy storage system may be affected by the sudden power failure of the whole machine to cause the photovoltaic energy storage inverter to fail, thereby affecting the safe and stable operation of the photovoltaic energy storage system. CONTENT OF THE INVENTION

[0004] The present application provides a photovoltaic energy storage converter and a grid-connected and off-grid switching device, system and equipment thereof to solve the problem of poor safe and stable operation performance of the photovoltaic energy storage system caused by power failure of the power grid in the prior art.

[0005] In a first aspect, the present application provides a grid-connected and off-grid switching device of a photovoltaic energy storage converter, comprising: an electric signal detection unit, a gear shift triggering unit, a grid-connected and off-grid gear shift switch and a control unit.

[0006] The first detection end of the electric signal detection unit is electrically connected with the detection end of the grid-connected and off-grid gear shift switch, the second detection end of the electric signal detection unit is electrically connected with the photovoltaic energy storage converter alternating current bus, the third detection end of the electric signal detection unit is electrically connected with the power grid alternating current bus, the first end of the grid-connected and off-grid gear shift switch is electrically connected with the photovoltaic energy storage converter alternating current bus, the second end of the grid-connected and off-grid gear shift switch is electrically connected with the power grid alternating current bus, the control end of the grid-connected and off-grid gear shift switch is electrically connected with the output end of the gear shift triggering unit, the control input end of the gear shift triggering unit is electrically connected with the switching output end of the control unit, and the detection input end of the control unit is electrically connected with the output end of the electric signal detection unit.

[0007] The electric signal detection unit is configured to detect an electric signal.

[0008] The control unit is configured to output a switching trigger signal corresponding to the electrical signal to the switching trigger unit based on the electrical signal, and to trigger the power-off protection mechanism of the optical-storage converter in the event of a power failure.

[0009] The shift triggering unit is used to output a control signal corresponding to the shift triggering signal to the grid-connected / off-grid shift switch according to the shift triggering signal;

[0010] The grid-connected / off-grid switching switch is used to switch the grid-connected / off-grid status of the optical-storage converter according to the control signal.

[0011] Optionally, the grid connection / disconnection switch includes a grid connection / disconnection contactor, the first end of which is electrically connected to the AC bus of the photovoltaic-storage converter, and the second end of which is electrically connected to the AC bus of the power grid.

[0012] The control signal is divided into a first control signal and a second control signal. The first control signal is used to control the grid-connected contactor to close, and the second control signal is used to control the grid-connected contactor to open.

[0013] When the grid-connected contactor is closed, the optical-storage converter enters the grid-connected state;

[0014] When the grid-connector is disconnected, the optical-storage converter enters the off-grid state.

[0015] Optionally, the electrical signal detection unit includes a current sampling circuit. The first sampling terminal of the current sampling circuit is electrically connected to the AC bus of the optical-storage converter, the second sampling terminal of the current sampling circuit is electrically connected to the DC bus of the optical-storage converter, and the output terminal of the current sampling circuit is electrically connected to the detection input terminal of the control unit. The first sampling terminal of the current sampling circuit is used to acquire the AC bus current signal, and the second sampling terminal of the current sampling circuit is used to acquire the DC bus current signal. The electrical signal includes the DC bus current signal and the AC bus current signal.

[0016] Optionally, the electrical signal detection unit includes a voltage sampling circuit. The first voltage sampling terminal of the voltage sampling circuit is electrically connected to the AC bus of the optical-storage converter, and the second voltage sampling terminal of the voltage sampling circuit is electrically connected to the DC bus of the optical-storage converter. The first voltage sampling terminal of the voltage sampling circuit is used to acquire the AC bus voltage signal, and the second voltage sampling terminal of the voltage sampling circuit is used to acquire the DC bus voltage signal. The electrical signal includes the DC bus voltage signal and the AC bus voltage signal.

[0017] Secondly, embodiments of this application provide an optical-storage converter, including a grid-connected / off-grid switching device as described in any of the first aspects of this application.

[0018] Optionally, the photovoltaic-storage converter further includes a bidirectional inverter module, which includes: a DC bus capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a first inductor, and a second inductor.

[0019] The control terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are electrically connected to the drive control terminal of the control unit. The first terminal of the DC bus capacitor, the first terminal of the first transistor, the first terminal of the third transistor, and the first DC bus of the photovoltaic energy storage converter are electrically connected. The second terminal of the DC bus capacitor, the second terminal of the second transistor, the second terminal of the fourth transistor, and the second DC bus of the photovoltaic energy storage converter are electrically connected.

[0020] The second terminal of the first transistor, the first terminal of the second transistor, and the first terminal of the first inductor are electrically connected. The second terminal of the third transistor, the first terminal of the fourth transistor, and the first terminal of the second inductor are electrically connected. The second terminal of the first inductor is electrically connected to the grid-connected contactor in the grid-connected switching device through the first AC bus of the photovoltaic-storage converter. The second terminal of the second inductor is electrically connected to the grid-connected contactor in the grid-connected switching device through the second AC bus of the photovoltaic-storage converter.

[0021] Optionally, the above-mentioned photovoltaic-storage converter also includes: a DC-DC conversion module and a photovoltaic module;

[0022] The input terminal of the DC-DC converter module is electrically connected to the output terminal of the photovoltaic module. The first output terminal of the DC-DC converter module is electrically connected to the first terminal of the DC bus capacitor through the first DC bus. The second output terminal of the DC-DC converter module is electrically connected to the second terminal of the DC bus capacitor through the second DC bus.

[0023] Optionally, the above-mentioned photovoltaic-energy storage converter further includes: an energy storage module and a display control module, wherein the DC conversion module includes a first DC conversion module and a second DC conversion module;

[0024] The input terminal of the first DC-DC converter module is electrically connected to the output terminal of the photovoltaic module. The first output terminal of the first DC-DC converter module, the first terminal of the second DC-DC converter module, the first terminal of the display control module, and the first terminal of the DC bus capacitor are electrically connected. The second output terminal of the first DC-DC converter module, the second terminal of the second DC-DC converter module, and the second terminal of the DC bus capacitor are electrically connected. The third terminal of the second DC-DC converter module is connected to the power supply terminal of the energy storage module.

[0025] The second end of the display control module is electrically connected to the AC bus of the optical storage converter. The first transmission end of the display control module establishes a communication connection with the communication end of the first DC-DC converter through a first communication link. The second transmission end of the display control module establishes a communication connection with the communication end of the second DC-DC converter through a second communication link.

[0026] Thirdly, embodiments of this application provide a mobile energy storage power supply system, including a photovoltaic-energy storage converter as described in any of the second aspects of this application.

[0027] Fourthly, embodiments of this application provide an electrical device including a photoelectric energy storage converter as described in any of the second aspects of this application.

[0028] Fifthly, embodiments of this application provide a method for switching between grid-connected and off-grid locations using an optical-storage converter, applied to the grid-connected and off-grid switching device described in any of the first aspects of this application. The method for switching between grid-connected and off-grid locations using the optical-storage converter includes:

[0029] The electrical signal is detected by the electrical signal detection unit;

[0030] Based on the electrical signal, the control unit outputs a switching trigger signal corresponding to the electrical signal, and triggers the power failure protection mechanism of the optical-storage converter in the event of a power failure;

[0031] Based on the gear shift trigger signal, the gear shift trigger unit outputs a control signal corresponding to the gear shift trigger signal;

[0032] According to the control signal, the grid connection / offline status of the optical storage converter is switched via the grid connection / offline switching switch.

[0033] In summary, the photovoltaic-storage converter and its grid-connected / off-grid switching device, system, and equipment provided in this application embodiment detect electrical signals through an electrical signal detection unit. Based on the detected electrical signals, the control unit outputs a switching trigger signal corresponding to the electrical signals, triggering the power outage protection mechanism of the photovoltaic-storage converter in the event of a power outage. This solves the fault problem caused by sudden power outages due to grid faults in existing related technologies. Furthermore, based on the switching trigger signal, the switching trigger unit outputs a control signal corresponding to the switching trigger signal. Based on the control signal, the grid-connected / off-grid switching switch switches the photovoltaic-storage converter to switch between grid-connected and off-grid states, achieving automatic switching between grid-connected and off-grid states. This solves the problem caused by using two independent interfaces to achieve separate grid-connected and off-grid designs in existing related technologies, effectively improving the stability and safety of the photovoltaic-storage converter operation. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0037] Figure 1 A schematic diagram of a grid-connected / off-grid switching device for an optical-storage converter provided in an embodiment of this application;

[0038] Figure 2 A connection diagram of an off-grid contactor is provided as an example of this application;

[0039] Figure 3 A schematic diagram illustrating current and voltage detection via an electrical signal detection unit, provided as an optional embodiment of this application;

[0040] Figure 4 This is a schematic diagram of the connection between a current sampling circuit and a control unit, provided in an optional embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the connection between a voltage sampling circuit and a control unit, provided in an optional embodiment of this application;

[0042] Figure 6 A structural block diagram of an optical-storage converter provided in an embodiment of this application;

[0043] Figure 7 A schematic diagram of the structure of an optical-storage converter is provided as an example of this application;

[0044] Figure 8 A schematic diagram illustrating the overall operation and fault detection self-protection process of an optical-storage converter provided as an example in this application;

[0045] Figure 9 A structural block diagram of a mobile energy storage power supply system provided in an embodiment of this application;

[0046] Figure 10 This is a schematic diagram of the structure of an electrical device provided in an embodiment of this application;

[0047] Figure 11 A flowchart illustrating the steps of a grid-to-offline switching method for an optical-storage converter provided in this application embodiment. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0050] In existing related technologies, the design requirements for photovoltaic-storage converters are small size, high efficiency, low standby power consumption and safety and reliability, and they also have the functions of bidirectional power supply and grid-connected and off-grid operation. That is, the photovoltaic-storage converter can reliably start and operate in any mode, whether off-grid or grid-connected. This requires that the photovoltaic-storage converter can operate normally off-grid after the grid is cut off, and can be connected to the grid normally after the grid power supply is restored.

[0051] Based on the above, this application provides a photovoltaic-storage converter and its grid-connected / off-grid switching device, system, and equipment. By adding a grid-connected / off-grid switching device to the photovoltaic-storage converter, automatic grid-connected / off-grid switching is achieved, enabling the photovoltaic-storage converter to promptly trigger its own protection mechanism in the event of a power outage due to a grid fault or power restoration without warning, thus preventing itself from malfunctioning.

[0052] Figure 1 This is a structural block diagram of a grid-connected / off-grid switching device for a photovoltaic-storage inverter provided in an embodiment of this application. In a specific implementation, the grid-connected / off-grid switching device provided in this embodiment can be configured to connect the photovoltaic-storage inverter to the power grid, allowing the inverter to be connected to the AC power grid via this device. Figure 1 As shown, the grid-connected / off-grid switching device of the photovoltaic-storage converter may specifically include: an electrical signal detection unit 110, a switching trigger unit 120, a grid-connected / off-grid switching switch 130, and a control unit 140; wherein, the first detection terminal of the electrical signal detection unit 110 is electrically connected to the detection terminal of the grid-connected / off-grid switching switch 130, so that the electrical signal detection unit 110 can detect the grid-connected / off-grid switching switch 130 through the first detection terminal of the electrical signal detection unit 110, and the second detection terminal of the electrical signal detection unit 110 is electrically connected to the AC bus 150 of the photovoltaic-storage converter. The connection allows the electrical signal detection unit 110 to detect the AC bus 150 of the photovoltaic-storage converter through its second detection terminal. The third detection terminal of the electrical signal detection unit 110 is electrically connected to the AC bus 160 of the power grid, allowing the electrical signal detection unit 110 to detect the AC bus 160 of the power grid through its third detection terminal. This enables the switching of the grid-connected and off-grid switching devices based on the electrical signals detected by the electrical signal detection unit 110, thereby realizing the grid-connected and off-grid switching of the photovoltaic-storage converter.

[0053] Specifically, in this embodiment, the electrical signal detection unit 110 is used to detect electrical signals, and the detection input terminal of the control unit 140 is electrically connected to the output terminal of the electrical signal detection unit 110, so that the control unit 140 can acquire the electrical signal detected by the electrical signal detection unit 110. Furthermore, the control input terminal of the switching trigger unit 120 is electrically connected to the switching output terminal of the control unit 140, so that the control unit 140 can output a switching trigger signal corresponding to the electrical signal to the switching trigger unit 120 based on the electrical signal detected by the electrical signal detection unit 110, and trigger the power outage protection mechanism of the photovoltaic energy storage converter in the event of a power outage. This effectively avoids faults caused by sudden power outages from the power grid, thus solving the problem of faults caused by sudden power outages due to power grid faults in existing related technologies.

[0054] As can be seen, the control unit 140 in this embodiment is used to output a switching trigger signal corresponding to the electrical signal to the switching trigger unit 120 according to the electrical signal, and to trigger the power failure protection mechanism of the photovoltaic energy storage converter in the event of a power failure, thereby solving the fault problem caused by sudden power failure due to grid fault in the existing related technologies.

[0055] Furthermore, the grid-connected / off-grid switching device in this embodiment can achieve grid-connected / off-grid switching via the grid-connected / off-grid switching switch 130. Specifically, when the first terminal of the grid-connected / off-grid switching switch 130 is electrically connected to the AC bus 150 of the photovoltaic-storage converter, and the second terminal of the grid-connected / off-grid switching switch 130 is electrically connected to the AC bus 160 of the power grid, if the first terminal and the second terminal of the grid-connected / off-grid switching switch 130 are in a closed conducting state, then the AC bus 150 of the photovoltaic-storage converter and the AC bus 160 of the power grid... When line 160 is in the connected state, the photovoltaic-storage converter enters the grid-connected state and can then operate in the grid-connected working mode. If the first and second ends of the grid-connected / off-grid switching switch 130 are in the disconnected state, the AC bus 150 of the photovoltaic-storage converter is disconnected from the AC bus 160 of the power grid, that is, the AC bus 150 of the photovoltaic-storage converter and the AC bus 160 of the power grid enter the disconnected state, causing the photovoltaic-storage converter to enter the off-grid state and thus enter the off-grid working mode.

[0056] In a specific implementation, the control terminal of the grid-connected / off-grid switching switch 130 is electrically connected to the output terminal of the switching trigger unit 120, enabling the grid-connected / off-grid switching switch 130 to switch the optical-storage converter between grid-connected and off-grid states based on the control signal output by the switching trigger unit 120. Specifically, the switching trigger unit 120 outputs a control signal corresponding to the switching trigger signal to the grid-connected / off-grid switching switch 130; the grid-connected / off-grid switching switch 130 then switches the optical-storage converter between grid-connected and off-grid states based on the control signal.

[0057] For example, when the control signal output by the grid-connected triggering unit 120 is divided into a first control signal and a second control signal, the first control signal can trigger the first and second terminals of the grid-connected / off-grid-connected switch 130 to close, causing the first and second terminals of the grid-connected / off-grid switch 130 to enter a closed conducting state. This allows the AC bus 150 of the photovoltaic-storage converter to enter a connected conducting state with the AC bus 160 of the power grid, controlling the photovoltaic-storage converter to enter a grid-connected state, i.e., the grid-connected / off-grid switch 130... The photovoltaic-storage converter is switched to grid-connected state according to the first control signal; similarly, the first terminal of the grid-connected / off-grid switching switch 130 can be disconnected from the second terminal of the grid-connected / off-grid switching switch 130 by the second control signal, so that the first terminal of the grid-connected / off-grid switching switch 130 and the second terminal of the grid-connected / off-grid switching switch 130 enter the disconnected state, thereby disconnecting the AC bus 150 of the photovoltaic-storage converter from the AC bus 160 of the power grid, and controlling the photovoltaic-storage converter to enter the off-grid state. That is, the grid-connected / off-grid switching switch 130 controls the photovoltaic-storage converter to switch to the off-grid state according to the second control signal.

[0058] Of course, in this embodiment, the first control signal can be used to control the photovoltaic-storage converter to enter the grid-connected state, and the second control signal can be used to control the photovoltaic-storage converter to enter the off-grid state. That is, the first control signal can be used to control the first terminal of the grid-connected / off-grid switching switch 130 to disconnect from the second terminal of the grid-connected / off-grid switching switch 130, and the second control signal can be used to control the first terminal of the grid-connected / off-grid switching switch 130 to close from the second terminal of the grid-connected / off-grid switching switch 130. This embodiment does not limit this.

[0059] In summary, the off-grid switching device provided in this application includes an electrical signal detection unit 110, a switching trigger unit 120, a grid-connected / off-grid switching switch 130, and a control unit 140. The electrical signal detection unit 110 detects the electrical signal and feeds it back to the control unit 140, allowing the control unit 140 to output a switching trigger signal corresponding to the electrical signal to the switching trigger unit 120. This triggers the power outage protection mechanism of the photovoltaic-storage converter in the event of a power outage, thereby solving the fault problems caused by sudden grid power outages in existing related technologies; and enabling grid-connected / off-grid switching... The control terminal of the grid-connected switch 130 is electrically connected to the output terminal of the grid-connected trigger unit 120, so that the grid-connected trigger unit 120 can output a control signal corresponding to the grid-connected trigger signal output by the control unit 140 to the grid-connected / off-grid-connected switch 130. The grid-connected / off-grid-connected switch 130 can switch the photovoltaic-storage converter between grid-connected and off-grid states according to the control signal, thereby realizing automatic switching between grid-connected and off-grid states. This solves the problem caused by the use of two independent interfaces to achieve separate grid-connected and off-grid designs in existing related technologies, and can effectively improve the stability and safety of photovoltaic-storage converter operation.

[0060] Optionally, the grid connection / off-grid switching switch 130 in this embodiment may include a grid connection / off-grid contactor, such as... Figure 2 As shown, the first end of the grid-connected contactor is electrically connected to the AC bus 150 of the photovoltaic-storage converter, and the second end of the grid-connected contactor is electrically connected to the AC bus 160 of the power grid. This allows the grid-connected contactor to serve as a single AC grid-connected interface for the photovoltaic-storage converter, enabling automatic grid-connected / off-grid switching. The DC-DC converter module can be used to implement maximum power output control of photovoltaic power generation, i.e., maximum power point tracking (MPPT) control. The DC / AC module can serve as a bidirectional inverter module in the photovoltaic-storage converter, specifically a DC-to-AC bidirectional module supporting grid-connected / off-grid switching functionality.

[0061] Optionally, the control signal output by the grid-connection trigger unit 120 can be divided into a first control signal and a second control signal. The first control signal is used to control the grid-connection contactor to close, and the second control signal is used to control the grid-connection contactor to open. When the grid-connection contactor is closed, the photovoltaic-storage converter can be connected to the grid interface through the closed grid-connection contactor, that is, the photovoltaic-storage converter enters the grid-connected state. When the grid-connection contactor is open, the connection between the photovoltaic-storage converter and the grid interface can be disconnected, that is, the photovoltaic-storage converter enters the off-grid state.

[0062] Optionally, the electrical signal detection unit 110 in this embodiment may include a current sampling circuit 111 to detect current signals, thereby achieving current signal detection. The detected current signal can be transmitted to the control unit 140 as an electrical signal detected by the electrical signal detection unit 110, so that the control unit 140 can obtain the current signal detected by the current sampling circuit 111 and process it based on the current signal to make a judgment based on the signal processing result. For example, a switching trigger signal can be generated based on the detected electrical signal and sent to the switching trigger unit 120 to trigger the switching trigger unit 120 to control the grid-connected / off-grid switching switch 130, thereby achieving grid-connected / off-grid state switching.

[0063] In some optional embodiments of this application, the first sampling terminal of the current sampling circuit 111 is electrically connected to the AC bus 150 of the optical-storage converter, so that the electrical signal detection unit 110 can collect the current of the AC bus 150 of the optical-storage converter through the first sampling terminal of the current sampling circuit 111, such as... Figure 3As shown, this enables AC bus current sampling, and the collected AC bus current signal can be used as a detected electrical signal and transmitted to the control unit 140. The second sampling terminal of the current sampling circuit 111 is electrically connected to the DC bus of the photovoltaic-storage converter, so that the electrical signal detection unit 110 can collect the current of the DC bus of the photovoltaic-storage converter through the second sampling terminal of the current sampling circuit 111, thereby realizing DC bus current sampling, and the collected DC bus current signal can be used as a detected electrical signal and transmitted to the control unit 140. Furthermore, the output terminal of the current sampling circuit 111 is electrically connected to the detection input terminal of the control unit 140, so that the control unit 140 can obtain various current signals collected by the current sampling circuit 111 as detected electrical signals. Subsequently, the control unit 140 can process the current signal to generate a switching trigger signal corresponding to the electrical signal, and trigger the power-off protection mechanism of the photovoltaic-storage converter in the event of a power failure to prevent itself from malfunctioning. The first sampling terminal of the current sampling circuit 111 is used to acquire the AC bus current signal, and the second sampling terminal of the current sampling circuit 111 is used to acquire the DC bus current signal. The electrical signal includes the DC bus current signal and the AC bus current signal.

[0064] For example, when the self-protection mechanism of the photovoltaic-storage converter is set as its power-off protection mechanism, in the event of a grid fault or a power outage followed by unannounced power restoration, the control unit 140 can process the electrical signals detected by the electrical signal detection unit 110, such as the DC bus current signal and AC bus current signal collected by the current sampling circuit 111. Based on the processing result, the control unit 140 triggers the self-protection mechanism of the photovoltaic-storage converter to prevent itself from malfunctioning due to grid faults. This effectively ensures the normal operation of the photovoltaic-storage converter and improves its operational stability and safety. Here, the DC bus current signal refers to the current signal of the DC bus, and the AC bus current signal refers to the current signal of the AC bus.

[0065] In some optional embodiments of this application, the electrical signal detection unit 110 may be implemented using a detection circuit such as an electrical signal detection amplifier circuit or an integrated electrical signal detection circuit. This application does not impose specific limitations on this.

[0066] As an example of this application, the current sampling circuit 111 included in the electrical signal detection unit 110 serves as a current signal detection circuit and can be composed of resistors, capacitors, and amplifiers. In a specific implementation, the electrical signal detection unit 110 may include one or more current sampling circuits 111. Each current sampling circuit 111 may include a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a first amplifier OP1, as shown below. Figure 4 As shown, the first end of the first resistor R1 is used to connect to the first connection point of the current detection point. The second end of the first resistor R1, the non-inverting input of the first amplifier OP1, the second end of the third resistor R3, and the second end of the first capacitor C1 are electrically connected. The first end of the third resistor R3 and the first end of the first capacitor C1 are electrically connected to the power supply terminal of the current sampling circuit 111. This power supply terminal can be used to provide a 1.5V voltage to power the first amplifier OP1. The first end of the second resistor R2 is used to connect to the second connection point of the current detection point. The second end of the second resistor R2, the inverting input of the first amplifier OP1, the first end of the fourth resistor R4, and the first end of the second capacitor C2 are electrically connected. The second end of the fourth resistor R4 is electrically connected to the second end of the second capacitor C2. The output terminal of the first amplifier OP1 is electrically connected to the first end of the third capacitor C3 and the current detection output terminal Iout of the current sampling circuit 111 through the fifth resistor R5, so that the detected current signal is transmitted to the control unit 140 through the current detection output terminal Iout, so that the control unit 140 can obtain the current signal detected by the current sampling circuit 111 and realize current detection. The second terminal of the third capacitor C3 can be connected to the reference ground of the current sampling circuit 111, so that the current sampling circuit 111 can be filtered by the third capacitor C3 to ensure the stability of the output current signal. The current detection point refers to the current detection point. The current detection point can be any connection point on the AC bus 150 of the optical energy storage converter or any connection point on the DC bus of the optical energy storage converter. This application example does not limit this.

[0067] Of course, in addition to detecting the current signal through the current sampling circuit 111 as the detected electrical signal, the electrical signal detection unit 110 in this application embodiment can also detect the voltage signal through the voltage sampling circuit 112 and transmit the detected voltage signal as the detected electrical signal to the control unit 140. This application embodiment does not limit this.

[0068] Optionally, the electrical signal detection unit 110 in this embodiment includes a voltage sampling circuit 112 to detect voltage signals, thereby achieving voltage signal detection. The detected voltage signal can be transmitted to the control unit 140 as an electrical signal detected by the electrical signal detection unit 110, so that the control unit 140 can obtain the voltage signal detected by the voltage sampling circuit 112 and process it based on the voltage signal to make a judgment based on the signal processing result. For example, a switching trigger signal can be generated based on the detected electrical signal and sent to the switching trigger unit 120 to trigger the switching trigger unit 120 to control the grid-connected / off-grid switching switch 130, thereby achieving grid-connected / off-grid state switching.

[0069] In some optional embodiments of this application, the first voltage sampling terminal of the voltage sampling circuit 112 is electrically connected to the AC bus 150 of the photovoltaic-storage converter, so that the electrical signal detection unit 110 can collect the voltage of the AC bus 150 of the photovoltaic-storage converter through the first voltage sampling terminal of the voltage sampling circuit 112, and can transmit the collected AC bus voltage signal as a detected electrical signal to the control unit 140; the second voltage sampling terminal of the voltage sampling circuit 112 is electrically connected to the DC bus of the photovoltaic-storage converter, so that the electrical signal detection unit 110 can collect the voltage of the DC bus of the photovoltaic-storage converter through the second voltage sampling terminal of the voltage sampling circuit 112, and can transmit the collected DC bus voltage signal as a detected electrical signal to the control unit 140. The voltage sampling circuit 112 has a first voltage sampling terminal for acquiring AC bus voltage signals and a second voltage sampling terminal for acquiring DC bus voltage signals. The electrical signals include both the DC bus voltage signals and the AC bus voltage signals. The DC bus voltage signals refer to the voltage signals of the DC bus and the AC bus voltage signals refer to the voltage signals of the AC bus.

[0070] Optionally, the electrical signal detection unit 110 in this embodiment may include one or more voltage sampling circuits 112 to detect DC bus voltage signals and AC bus voltage signals. This embodiment does not impose a specific limit on the number of voltage sampling circuits 112.

[0071] For example, the electrical signal detection unit 110 may include two voltage sampling circuits 112; wherein, the voltage sampling terminal of one voltage sampling circuit 112 serves as the first voltage sampling terminal, which is electrically connected to the AC bus 150 of the optical-storage converter, and is used to collect the voltage of the AC bus 150 of the optical-storage converter and output the AC bus voltage signal to the control unit 140; the voltage sampling terminal of the other voltage sampling circuit 112 serves as the second voltage sampling terminal, which is electrically connected to the DC bus of the optical-storage converter, and is used to collect the voltage of the DC bus of the optical-storage converter and output the DC bus voltage signal to the control unit 140.

[0072] In a specific implementation, the voltage sampling circuit 112 can be implemented using resistors, capacitors, and amplifiers. This application embodiment does not impose specific limitations on the specific structure of the voltage sampling circuit 112. For example, each voltage sampling circuit 112 may include a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fourth capacitor C4, a fifth capacitor C5, and a second amplifier OP2, as shown below. Figure 5 As shown, the non-inverting input of the second amplifier OP2 is electrically connected to the first terminal Vin(+) of the voltage detection point through a series connection of the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9. The inverting input of the second amplifier OP2 is electrically connected to the second terminal Vin(-) of the voltage detection point through a series connection of the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12. The non-inverting input of the second amplifier OP2, the second terminal of the thirteenth resistor R13, and the second terminal of the fourth capacitor C4 are also electrically connected. The first terminal of the thirteenth resistor R13 and the first terminal of the fourth capacitor C4 are connected to the power supply of the voltage sampling circuit 112. The power supply terminal is electrically connected; this power supply terminal can be used to provide a 1.5V voltage to power the second amplifier OP2; the inverting input terminal of the second amplifier OP2, the first terminal of the fourteenth resistor R14, and the first terminal of the fifth capacitor C5 are electrically connected, and the second terminal of the fourteenth resistor R14 is electrically connected to the second terminal of the second capacitor; the output terminal of the second amplifier OP2 is electrically connected to the voltage detection output terminal Vout of the voltage sampling circuit 112, so that the detected voltage signal is transmitted to the control unit 140 through the voltage detection output terminal Vout, so that the control unit 140 can obtain the voltage signal detected by the voltage sampling circuit 112 and realize voltage detection. Here, the voltage detection point refers to the voltage detection point, which can be any voltage detection point on the AC bus 150 of the photovoltaic energy storage converter or any voltage detection point on the DC bus of the photovoltaic energy storage converter. This application example does not limit this.

[0073] In specific implementation, the grid-connected / off-grid switching device provided in this application embodiment can be integrated into the photovoltaic-storage converter, enabling the photovoltaic-storage converter to automatically switch between grid-connected and off-grid states through the grid-connected / off-grid switching device. This solves the problem caused by the separate design of grid-connected and off-grid states using two independent interfaces in the existing related technologies. Furthermore, it automatically triggers its own protection mechanism and terminates operation in the event of a grid power outage, so that the photovoltaic-storage converter can resume normal operation by manual reactivation by the user after the grid power supply is restored. This effectively improves the stability and safety of the photovoltaic-storage converter operation.

[0074] like Figure 6 As shown, this application provides an optical-storage converter 600, which includes a grid-connected / off-grid switching device 610. The grid-connected / off-grid switching device 610 can be any of the grid-connected / off-grid switching devices described in the above embodiments of this application. This allows the optical-storage converter 600 to detect electrical signals via an electrical signal detection unit 110, and based on these signals, output a switching trigger signal corresponding to the electrical signal to the switching trigger unit 120 via a control unit 140. Furthermore, in the event of a power outage, the optical-storage converter's own power-off protection mechanism is triggered, thereby resolving the power outage. This invention addresses the fault problems caused by sudden power outages in existing related technologies. Furthermore, based on the switching trigger signal, the switching trigger unit 120 outputs a control signal corresponding to the switching trigger signal to the grid-connected / off-grid switching switch 130. According to the control signal, the grid-connected / off-grid switching switch 130 switches the photovoltaic-storage converter between grid-connected and off-grid states, thereby achieving automatic switching between grid-connected and off-grid states. This solves the problems caused by using two independent interfaces to achieve separate grid-connected and off-grid designs in existing related technologies, effectively improving the stability and safety of the photovoltaic-storage converter operation.

[0075] In specific implementations, the photovoltaic-storage converter provided in this application embodiment may include not only a grid-connected / off-grid switching device, but also other circuit modules, such as a bidirectional inverter module, a DC-DC conversion module, a photovoltaic module, etc. This application embodiment does not impose specific limitations on this.

[0076] Optionally, based on the above embodiments, the photoelectric energy storage converter provided in this application embodiment further includes a bidirectional inverter module, which includes: a DC bus capacitor, a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a first inductor L1, and a second inductor L2; as shown Figure 2 or Figure 3As shown, the control terminals of the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 are electrically connected to the drive control terminal of the control unit 140. The first terminal of the DC bus capacitor, the first terminal of the first transistor Q1, the first terminal of the third transistor Q3, and the first DC bus of the photovoltaic-storage converter are electrically connected. The second terminal of the DC bus capacitor, the second terminal of the second transistor Q2, the second terminal of the fourth transistor Q4, and the second DC bus of the photovoltaic-storage converter are electrically connected. The second terminal of the first transistor Q1, the first terminal of the second transistor Q2, and the first terminal of the first inductor L1 are electrically connected. The second terminal of the third transistor Q3, the first terminal of the fourth transistor Q4, and the first terminal of the second inductor L2 are electrically connected. The second terminal of the first inductor L1 is electrically connected to the grid-connected / off-grid contactor in the grid-connected / off-grid switching device through the first AC bus of the photovoltaic-storage converter. The second terminal of the second inductor L2 is electrically connected to the grid-connected / off-grid contactor in the grid-connected / off-grid switching device through the second AC bus of the photovoltaic-storage converter. In this module, transistors Q1, Q2, Q3, and Q4 serve as switches in the bidirectional inverter module. The control unit 140 can adjust the duty cycle by controlling these switches, thereby regulating the output voltage. A DC bus capacitor refers to a capacitor on the DC bus. If the DC bus is divided into a first DC bus and a second DC bus, and one end of a capacitor is connected to the first DC bus while the other end is connected to the second DC bus, then that capacitor can be identified as a DC bus capacitor.

[0077] Optionally, the photovoltaic-storage converter in this embodiment further includes: a DC-DC conversion module and a photovoltaic module; the input terminal of the DC-DC conversion module is electrically connected to the output terminal of the photovoltaic module, the first output terminal of the DC-DC conversion module is electrically connected to the first terminal of the DC bus capacitor through the first DC bus, and the second output terminal of the DC-DC conversion module is electrically connected to the second terminal of the DC bus capacitor through the second DC bus.

[0078] Optionally, the photovoltaic-energy storage converter further includes: an energy storage module and a display control module. The DC-DC conversion module includes a first DC-DC conversion module and a second DC-DC conversion module. The input terminal of the first DC-DC conversion module is electrically connected to the output terminal of the photovoltaic module. The first output terminal of the first DC-DC conversion module, the first terminal of the second DC-DC conversion module, the first terminal of the display control module, and the first terminal of the DC bus capacitor are electrically connected. The second output terminal of the first DC-DC conversion module, the second terminal of the second DC-DC conversion module, and the second terminal of the DC bus capacitor are electrically connected. The third terminal of the second DC-DC conversion module is connected to the power supply terminal of the energy storage module. The second terminal of the display control module is electrically connected to the AC bus of the photovoltaic-energy storage converter. The first transmission terminal of the display control module establishes a communication connection with the communication terminal of the first DC-DC conversion module through a first communication link. The second transmission terminal of the display control module establishes a communication connection with the communication terminal of the second DC-DC conversion module through a second communication link. The energy storage module can serve as the energy storage battery management system (BMS) module of the photovoltaic-energy storage converter, enabling bidirectional charging and discharging of the energy storage battery.

[0079] As an example of this application, the AC / DC power supply device of the photovoltaic-storage converter can be composed of a photovoltaic module, a first DC conversion module, a second DC conversion module, an auxiliary power supply circuit, a DC bus, a bidirectional inverter module, an AC grid, an AC / DC auxiliary power supply module, and a battery management system (BMS) module. The photovoltaic module can serve as a photovoltaic MPPT module in the photovoltaic-storage converter, specifically providing access for photovoltaic power generation to the first DC conversion module in the photovoltaic-storage converter, such as... Figure 7 As shown; the first DC-DC conversion module, as the DC / DC module in the photovoltaic-storage converter, is used to realize the maximum power output control of photovoltaic power generation, i.e., MPPT control; the bidirectional inverter module, as the DC / AC module in the photovoltaic-storage converter, is a bidirectional module that realizes DC-to-AC conversion and supports grid-connected / off-grid switching; in order to increase the power of the machine through parallel expansion, the second DC-DC conversion module serves as a reserved photovoltaic DC-DC module in the photovoltaic-storage converter; the display control module is an external module for manually issuing commands, and this display control module can establish a communication connection with the first DC-DC conversion module, the second DC-DC conversion module, and the bidirectional inverter module through the 485 communication bus to form a 485 communication loop and realize communication control; the energy storage battery BMS module serves as the bidirectional charging and discharging module of the energy storage battery in the photovoltaic-storage converter, realizing bidirectional charging and discharging of the energy storage battery; the AC / DC auxiliary power supply module supports simultaneous access to AC and DC buses, and can convert high voltage isolation to low voltage DC to power the system control circuit, chips, etc., thereby meeting the power supply requirements of the system control circuit and chips.

[0080] In practical implementation, the overall operation of the optical-storage converter and the fault detection and self-protection process are as follows: Figure 8As shown, the photovoltaic-storage converter can detect whether it is connected to the grid through a program, i.e., determine whether there is power on the grid. This allows it to utilize the energy stored in the battery when not connected to the grid or when the grid is depleted. When there is power on the grid, the auxiliary power module receives power through the bidirectional inverter module input. Specifically, when the photovoltaic-storage converter is not connected to the grid or the grid is depleted, the electrical signal detected by the electrical signal detection unit can determine whether the energy storage battery has power. If the energy storage battery has power, it can receive power through the energy storage module input, i.e., through the energy storage battery BMS module acting as the energy storage module, enabling the auxiliary power module to receive power. When the energy storage battery also has no power, the electricity converted by the photovoltaic panels can be used to power the auxiliary power supply. This involves determining whether the photovoltaic module is working. If the photovoltaic module is working, the auxiliary power module receives power through the photovoltaic module input. Based on the power received by the auxiliary power module, the control unit, electrical signal detection unit, and switching trigger unit of the off-grid switching device are activated. In other words, the electrical signal detection unit, control unit, and switching trigger unit are activated, ensuring the normal operation of the entire unit. For example, if the control unit includes an MCU control driver chip, the voltage of the electrical energy can be converted into a voltage to power the MCU control driver chip through an auxiliary power supply module. This allows the MCU control driver chip to control the switching transistors to adjust the duty cycle, regulate the output voltage, and output it to the BMS module or bidirectional inverter module, thereby enabling the photovoltaic energy storage converter to work normally.

[0081] The MCU control driver chip can be integrated into the control unit 140 of the grid-connected switching device, enabling the control unit 140 to detect whether the power grid is interrupted in real time. If no power grid interruption is detected, the photovoltaic-storage converter will operate normally. If no power grid interruption is detected, the photovoltaic-storage converter can be triggered to activate its own protection mechanism and terminate operation according to the detected power grid interruption. After the power grid is restored, it can determine whether a user has manually closed the circuit breaker, and restart the photovoltaic-storage converter by manually closing the circuit breaker, so that the photovoltaic-storage converter can resume normal operation.

[0082] In one embodiment of this application, the photovoltaic-energy storage converter provided in this embodiment can be applied to a mobile energy storage power supply system, so that the mobile energy storage power supply system can be powered by the photovoltaic-energy storage converter.

[0083] like Figure 9 As shown, this application provides a mobile energy storage power supply system 900, which includes a photovoltaic energy storage converter 910. The photovoltaic energy storage converter 910 can be any of the photovoltaic energy storage converters described in the above embodiments of this application.

[0084] like Figure 10As shown, this application provides an electrical device 100, which includes a photovoltaic-storage converter 910. The photovoltaic-storage converter 910 may include the grid-connected / off-grid switching device described in any of the above embodiments of this application. This allows the electrical device 100 to detect electrical signals via an electrical signal detection unit 110 and feed these signals back to a control unit 140. The control unit 140 then outputs a switching trigger signal corresponding to the electrical signal to the switching trigger unit 120 based on the electrical signal, and triggers the power outage protection mechanism of the photovoltaic-storage converter in the event of a power outage. This solves the problem of power outages caused by sudden grid power failures in existing related technologies. The system addresses the issue of grid connection failures. Furthermore, the control terminal of the grid-connected / off-grid switching switch 130 is electrically connected to the output terminal of the switching trigger unit 120. This allows the switching trigger unit 120 to output a control signal corresponding to the switching trigger signal output by the control unit 140 to the grid-connected / off-grid switching switch 130. The grid-connected / off-grid switching switch 130 then switches the photovoltaic-storage converter between grid-connected and off-grid states based on the control signal, thus achieving automatic switching between grid-connected and off-grid states. This solves the problems caused by using two independent interfaces for separate grid-connected and off-grid designs in existing related technologies, effectively improving the stability and safety of the photovoltaic-storage converter operation. The electrical equipment 100 may include, but is not limited to, air conditioning equipment, refrigerators, and other electrical appliances; this embodiment does not impose such limitations.

[0085] like Figure 11 As shown in the diagram, this application provides a step-by-step flowchart of a grid-connected / off-grid switching method for an optical-storage converter. The grid-connected / off-grid switching method for an optical-storage converter provided in this application can be applied to any of the grid-connected / off-grid switching devices described in the above embodiments of this application, and specifically may include the following steps:

[0086] Step 1110: Detect the electrical signal using the electrical signal detection unit;

[0087] Step 1120: Based on the electrical signal, the control unit outputs a switching trigger signal corresponding to the electrical signal, and triggers the power-off protection mechanism of the optical-storage converter in the event of a power failure;

[0088] Step 1130: Based on the gear shift trigger signal, the gear shift trigger unit outputs a control signal corresponding to the gear shift trigger signal;

[0089] Step 1140: According to the control signal, the grid-connected / off-grid-connected state of the optical-storage converter is switched via the grid-connected / off-grid switching switch.

[0090] Specifically, the grid-connected / off-grid switching method for the photovoltaic-storage converter provided in this application embodiment can be applied to the grid-connected / off-grid switching device described in any of the above embodiments of this application. The device detects electrical signals through an electrical signal detection unit, processes these signals through a control unit, and outputs a switching trigger signal corresponding to the electrical signal. In the event of a power outage, the device triggers the power outage protection mechanism of the photovoltaic-storage converter, effectively preventing faults caused by sudden grid outages and solving the problem of sudden power outages due to grid faults in existing related technologies. Based on the switching trigger signal, and by outputting a control signal corresponding to the switching trigger signal through the switching trigger unit, the photovoltaic-storage converter is switched between grid-connected and off-grid states via a grid-connected / off-grid switching switch according to the control signal, thereby achieving automatic switching between grid-connected and off-grid states. This solves the problem caused by using two independent interfaces to achieve separate grid-connected and off-grid designs in existing related technologies, effectively improving the stability and safety of the photovoltaic-storage converter operation.

[0091] The device embodiments described above are merely illustrative. 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 modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, it can be implemented using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0093] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0094] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A grid-connected / off-grid switching device for an optical-storage converter, characterized in that, include: Electrical signal detection unit, switching trigger unit, and on-grid / off-grid switching switch and control unit; Specifically, the first detection terminal of the electrical signal detection unit is electrically connected to the detection terminal of the grid-connected / off-grid switching switch; the second detection terminal of the electrical signal detection unit is electrically connected to the AC bus of the photovoltaic-storage converter; the third detection terminal of the electrical signal detection unit is electrically connected to the AC bus of the power grid; the first terminal of the grid-connected / off-grid switching switch is electrically connected to the AC bus of the photovoltaic-storage converter; the second terminal of the grid-connected / off-grid switching switch is electrically connected to the AC bus of the power grid; the control terminal of the grid-connected / off-grid switching switch is electrically connected to the output terminal of the switching trigger unit; the control input terminal of the switching trigger unit is electrically connected to the switching output terminal of the control unit; and the detection input terminal of the control unit is electrically connected to the output terminal of the electrical signal detection unit. The electrical signal detection unit is used to detect electrical signals; The control unit is configured to output a switching trigger signal corresponding to the electrical signal to the switching trigger unit based on the electrical signal, and to trigger the power-off protection mechanism of the optical-storage converter in the event of a power failure. The shift triggering unit is used to output a control signal corresponding to the shift triggering signal to the grid-connected / off-grid shift switch according to the shift triggering signal; The grid-connected / off-grid switching switch is used to switch the grid-connected / off-grid status of the optical-storage converter according to the control signal.

2. The grid-connected / off-grid switching device according to claim 1, characterized in that, The grid connection / off-grid switching switch includes a grid connection / off-grid contactor, the first end of which is electrically connected to the AC bus of the photovoltaic-storage converter, and the second end of which is electrically connected to the AC bus of the power grid. The control signal is divided into a first control signal and a second control signal. The first control signal is used to control the grid-connected contactor to close, and the second control signal is used to control the grid-connected contactor to open. When the grid-connected contactor is closed, the optical-storage converter enters the grid-connected state; When the grid-connector is disconnected, the optical-storage converter enters the off-grid state.

3. The grid-connected / off-grid switching device according to claim 1, characterized in that, The electrical signal detection unit includes a current sampling circuit. The first sampling terminal of the current sampling circuit is electrically connected to the AC bus of the optical-storage converter, and the second sampling terminal of the current sampling circuit is electrically connected to the DC bus of the optical-storage converter. The output terminal of the current sampling circuit is electrically connected to the detection input terminal of the control unit. The first sampling terminal of the current sampling circuit is used to acquire the AC bus current signal, and the second sampling terminal of the current sampling circuit is used to acquire the DC bus current signal. The electrical signal includes the DC bus current signal and the AC bus current signal.

4. The grid-connected / off-grid switching device according to claim 1, characterized in that, The electrical signal detection unit includes a voltage sampling circuit. The first voltage sampling terminal of the voltage sampling circuit is electrically connected to the AC bus of the optical-storage converter, and the second voltage sampling terminal of the voltage sampling circuit is electrically connected to the DC bus of the optical-storage converter. The first voltage sampling terminal of the voltage sampling circuit is used to acquire the AC bus voltage signal, and the second voltage sampling terminal of the voltage sampling circuit is used to acquire the DC bus voltage signal. The electrical signal includes the DC bus voltage signal and the AC bus voltage signal.

5. An optical-storage converter, characterized in that, The optical-storage converter includes the on-grid / off-grid switching device as described in any one of claims 1 to 4.

6. The optical-storage converter according to claim 5, characterized in that, The photovoltaic-storage converter also includes a bidirectional inverter module, which comprises: a DC bus capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a first inductor, and a second inductor. The control terminals of the first transistor, the second transistor, the third transistor, and the fourth transistor are electrically connected to the drive control terminal of the control unit. The first terminal of the DC bus capacitor, the first terminal of the first transistor, the first terminal of the third transistor, and the first DC bus of the photovoltaic energy storage converter are electrically connected. The second terminal of the DC bus capacitor, the second terminal of the second transistor, the second terminal of the fourth transistor, and the second DC bus of the photovoltaic energy storage converter are electrically connected. The second terminal of the first transistor, the first terminal of the second transistor, and the first terminal of the first inductor are electrically connected. The second terminal of the third transistor, the first terminal of the fourth transistor, and the first terminal of the second inductor are electrically connected. The second terminal of the first inductor is electrically connected to the grid-connected contactor in the grid-connected switching device through the first AC bus of the photovoltaic-storage converter. The second terminal of the second inductor is electrically connected to the grid-connected contactor in the grid-connected switching device through the second AC bus of the photovoltaic-storage converter.

7. The optical-storage converter according to claim 6, characterized in that, Also includes: DC-DC conversion modules and photovoltaic modules; The input terminal of the DC-DC converter module is electrically connected to the output terminal of the photovoltaic module. The first output terminal of the DC-DC converter module is electrically connected to the first terminal of the DC bus capacitor through the first DC bus. The second output terminal of the DC-DC converter module is electrically connected to the second terminal of the DC bus capacitor through the second DC bus.

8. The optical-storage converter according to claim 7, characterized in that, Also includes: The battery storage module and the display control module, wherein the DC-DC conversion module includes a first DC-DC conversion module and a second DC-DC conversion module; The input terminal of the first DC-DC converter module is electrically connected to the output terminal of the photovoltaic module. The first output terminal of the first DC-DC converter module, the first terminal of the second DC-DC converter module, the first terminal of the display control module, and the first terminal of the DC bus capacitor are electrically connected. The second output terminal of the first DC-DC converter module, the second terminal of the second DC-DC converter module, and the second terminal of the DC bus capacitor are electrically connected. The third terminal of the second DC-DC converter module is connected to the power supply terminal of the energy storage module. The second end of the display control module is electrically connected to the AC bus of the optical storage converter. The first transmission end of the display control module establishes a communication connection with the communication end of the first DC-DC converter through a first communication link. The second transmission end of the display control module establishes a communication connection with the communication end of the second DC-DC converter through a second communication link.

9. A mobile energy storage power supply system, characterized in that, include: The optical-storage converter as described in any one of claims 5 to 8.

10. An electrical appliance, characterized in that, It includes the optical-storage converter as described in any one of claims 5 to 8.

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