Grid-connected relay control circuit and device and energy storage inverter circuit

Abstract

The embodiment of the invention discloses a grid-connected relay control circuit and device and an energy storage inverter circuit. The grid-connected relay control circuit comprises a potential adjusting unit, a first switch unit, a second switch unit and a coil switch unit, the potential adjusting unit is used for inputting a first power supply voltage, the potential adjusting unit, the first switch unit and the second switch unit are respectively connected to a first node, and the first switch unit is used for generating a first coil control signal according to a first type control signal; the second switch unit is used for generating a second coil control signal according to the second type control signal under the first preset working condition; the coil switch unit is connected with the grounding end and the grid-connected relay, the control end of the coil switch unit is connected with the first node, and the coil switch unit is used for controlling the grid-connected relay to be closed or opened according to the first coil control signal and controlling the grid-connected relay to maintain the closed state or the opened state according to the second coil control signal under the first preset working condition. According to the technical scheme provided by the embodiment, the load power supply reliability is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of grid connection, and in particular, to a grid connection relay control circuit, a device, and an energy storage inverter circuit. Background Art

[0002] With the rapid development of the photovoltaic energy storage system, the installed capacity of the energy storage system has increased geometrically, and a large number of energy storage photovoltaic power stations have been established. Generally, the energy storage inverters used in the existing energy storage systems have both grid connection and off-grid functions, and can perform grid-connected / off-grid switching according to the real-time working conditions. When switching, inverter relays and grid connection relays are required to control grid-connected power generation or off-grid independent operation. When switching, when the inverter needs to shut down, or shuts down due to a fault, or needs to perform grid-connected / off-grid switching, or the DSP needs to perform program upgrade and reset, it will cause the grid connection relay to trip and the load to lose power. Usually, in on-site use, it is not desired that the load loses power when the power grid is normal and the energy storage inverter functions normally, which not only affects the operation of the load but also brings a very bad experience to the user.

[0003] The existing grid connection relay control circuit is prone to the situation of load power loss, reducing the reliability of load power supply and affecting the user experience. Summary of the Invention

[0004] The embodiments of the present invention provide a grid connection relay control circuit, a device, and an energy storage inverter circuit to solve the problem that the grid connection relay control circuit is prone to the situation of load power loss, reducing the reliability of load power supply and affecting the user experience.

[0005] To achieve the above technical problems, the present invention adopts the following technical solutions:

[0006] The embodiments of the present invention provide a grid connection relay control circuit, including: a potential regulation unit, a first switch unit, a second switch unit, and a coil switch unit;

[0007] The potential regulation unit is used to input a first power supply voltage. The potential regulation unit is respectively connected to the first switch unit and the second switch unit at a first node. The first switch unit is used to generate a first coil control signal according to a first type of control signal. The second switch unit is used to generate a second coil control signal according to a second type of control signal under a first preset working condition;

[0008] The coil switch unit is connected between the ground terminal and the grid-connected relay. The control terminal of the coil switch unit is connected to the first node. The coil switch unit is configured to control the grid-connected relay to close or open according to the first coil control signal; and under the first preset operating condition, control the grid-connected relay to maintain the closed state or open according to the second coil control signal.

[0009] According to the second aspect of the present invention, the present embodiment provides a grid-connected relay control device, including the grid-connected relay control circuit proposed in the first aspect; the grid-connected relay control device is connected to the control terminal of the grid-connected relay of the energy storage inverter circuit. The energy storage inverter circuit includes: a power source, a load, and a grid-connected relay. The power source is connected to the load and the first end of the grid-connected relay at a fifth node. The second end of the grid-connected relay is connected to the power grid at a sixth node;

[0010] The grid-connected relay control device further includes a sampling control module, which is connected to the sixth node and is configured to collect the first voltage of at least one phase of the three-phase voltage of the sixth node;

[0011] The grid-connected relay control circuit is connected to the sampling control module and the control terminal of the grid-connected relay. The grid-connected relay control circuit is configured to control the sub-switch unit of the grid-connected relay connected to the N phase of the sixth node to close, and according to the difference between the first voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line where the amplitude of the first voltage is less than or equal to the preset threshold voltage to close.

[0012] Optionally, the first voltage of at least one phase of the sixth node includes at least one of the A-phase voltage, B-phase voltage, and C-phase voltage of the power grid; the grid-connected relay control circuit is specifically configured to:

[0013] According to the difference between the absolute value of the amplitude of the A-phase voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line where the absolute value of the amplitude of the A-phase voltage is less than or equal to the preset threshold voltage to be powered on and closed;

[0014] According to the difference between the absolute value of the amplitude of the B-phase voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line where the absolute value of the amplitude of the B-phase voltage is less than or equal to the preset threshold voltage to be powered on and closed;

[0015] According to the difference between the absolute value of the amplitude of the C-phase voltage and the preset threshold voltage, control the grid-connected relay connected to the phase line where the absolute value of the amplitude of the C-phase voltage is less than or equal to the preset threshold voltage to be closed.

[0016] Optionally, the sampling control module includes a first sampling control unit. The first sampling control unit and the grid-connected relay are respectively connected to the fifth node and the sixth node; the first sampling control unit is connected to the grid-connected relay control circuit;

[0017] The first sampling control unit is configured to collect at least one phase of the second voltage at the fifth node and at least one phase of the first voltage at the sixth node. When the first voltage and the second voltage are not faulty, according to the difference between the first voltage and a preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line where the amplitude of the first voltage is less than or equal to the preset threshold voltage to be powered on and closed; wherein, the preset threshold voltage includes zero volts.

[0018] Optionally, the first sampling control unit includes:

[0019] A DSP sampling controller. The DSP sampling controller and the grid-connected relay are connected to the fifth node and the sixth node. The DSP sampling controller is configured to perform phase-locked loop operation after the voltage conversion module of the power supply operates in open loop for a first preset time. When the open-loop voltage and phase of the voltage conversion module are the same as the voltage and phase of the power grid, control the sub-switch unit of the grid-connected relay connected to the N phase of the sixth node to be closed, and when any one of the A-phase voltage, B-phase voltage, and C-phase voltage of the first voltage is equal to the preset threshold voltage, control the sub-switch unit of the grid-connected relay corresponding to the first voltage equal to the preset threshold voltage to be closed.

[0020] Optionally, the sampling control module further includes a second sampling control unit. The second sampling control unit is connected to the first sampling control unit. The second sampling control unit and the grid-connected relay are connected to the fifth node and the sixth node; the second sampling control unit is connected to the grid-connected relay control circuit;

[0021] The second sampling control unit is configured to collect at least one phase of the second voltage at the fifth node and at least one phase of the first voltage at the sixth node. When the first voltage and the second voltage are not faulty, maintain the grid-connected relay powered on and closed according to the first voltage. When the first voltage and / or the second voltage is faulty, control the grid-connected relay to be powered off.

[0022] Optionally, the second sampling control unit includes:

[0023] The MCU sampling controller is communicatively connected to the DSP sampling controller, and is respectively connected to the grid-connected relay at the fifth node and the sixth node; the MCU sampling controller is respectively connected to the load and the voltage conversion module of the power supply; the MCU sampling controller is configured to take over the control right of the DSP sampling controller when the DSP sampling controller performs reset and upgrade, shutdown, or grid connection / disconnection, and the energy storage inverter circuit is connected to a load, control the grid-connected relay to remain in the closed state, and control the grid-connected relay to disconnect when a fault occurs in the power supply, the load, and / or the grid-connected relay.

[0024] According to a third aspect of the present invention, the present embodiment provides an energy storage inverter circuit, including: a power supply, a load, and a grid-connected relay. The power supply is connected to the load and the first end of the grid-connected relay at a fifth node, the second end of the grid-connected relay is connected to the power grid at a sixth node, and the control end of the grid-connected relay is connected to the grid-connected relay control circuit proposed in any item of the first aspect, and / or, connected to the grid-connected relay control device proposed in any item of the second aspect.

[0025] The grid-connected relay control circuit provided by the embodiment of the present invention inputs a first power supply voltage by setting a potential adjustment unit. The potential adjustment unit is respectively connected to the first switch unit and the second switch unit at a first node. The first switch unit is configured to generate a first coil control signal according to a first type of control signal and output it to the first node. The second switch unit is configured to generate a second coil control signal according to a second type of control signal under a first preset working condition. The control end of the coil switch unit controls the grid-connected relay to close according to the first coil control signal to realize grid-connected operation. Under the first preset working condition, the grid-connected relay is controlled to maintain the closed state according to the second coil control signal, so that the power supply reliability of the load can be better improved. In addition, when a fault occurs in the energy storage inverter circuit, both the first control unit and the second control unit can control the grid-connected relay to disconnect in time, which can improve the grid connection safety and reliability of the energy storage inverter circuit. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0027] Figure 1 It is a schematic structural diagram of a grid-connected relay control circuit provided by an embodiment of the present invention;

[0028] Figure 2It is a schematic structural diagram of another grid-connected relay control circuit provided by an embodiment of the present invention;

[0029] Figure 3 It is a schematic structural diagram of yet another grid-connected relay control circuit provided by an embodiment of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a grid-connected relay provided by an embodiment of the present invention;

[0031] Figure 5 It is a schematic structural diagram of an energy storage inverter circuit provided by an embodiment of the present invention;

[0032] Figure 6 It is a schematic structural diagram of another energy storage inverter circuit provided by an embodiment of the present invention. Detailed implementation manners

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] Based on the above technical problems, the following solutions are proposed in this embodiment:

[0036] Figure 1 It is a schematic structural diagram of a grid-connected relay control circuit provided by an embodiment of the present invention. Refer to Figure 1, the grid-connected relay control circuit 100 provided by the embodiment of the present invention includes: a potential regulating unit 1, a first switch unit 2, a second switch unit 3, and a coil switch unit 4; the potential regulating unit 1 is used to input a first power supply voltage U1, and the potential regulating unit 1 is respectively connected to the first switch unit 2 and the second switch unit 3 at a first node N1. The first switch unit 2 is used to generate a first coil control signal according to a first type of control signal Grid_Rely_Ctrl K8 / 9 / 2 / 4 / 6; the second switch unit 3 is used to generate a second coil control signal according to a second type of control signal MCU_RlyHold under a first preset working condition; the coil switch unit 4 is connected between the ground terminal and the grid-connected relay, and the control end of the coil switch unit 4 is connected to the first node N1. The coil switch unit 4 is used to control the grid-connected relay to close or open according to the first coil control signal; and under the first preset working condition, control the grid-connected relay to maintain the closed state or open according to the second coil control signal.

[0037] Specifically, the first type of control signal can be a DSP control signal. The second type of control signal can be an MCU control signal. Or, the first type of control signal and the second type of control signal can be control signals generated by other digital or analog chips or circuits. The grid-connected relay can be a device that can implement a switching function such as a relay, a thyristor, or a controllable switch.

[0038] The first power supply voltage U1 can be a DC voltage, such as +12V. The potential regulating unit 1 is used to input the first power supply voltage U1, and the output end of the potential regulating unit 1 is respectively connected to the output ends of the first switch unit 2 and the second switch unit 3 at the first node N1. The control end of the first switch unit 2 inputs the first type of control signal. The first switch unit 2 generates a first coil control signal according to the first type of control signal Grid_Rely_Ctrl K8 / 9 / 2 / 4 / 6. The control end of the second switch unit 3 inputs the second type of control signal. The second switch unit 3 is used to generate a second coil control signal according to the second type of control signal MCU_RlyHold under the first preset working condition.

[0039] The control end of the coil switch unit 4 is connected to the first node N1, and the control end of the coil switch unit 4 is used to receive the first coil control signal or the second coil control signal. When the coil switch unit 4 controls the grid-connected relay to close according to the first coil control signal, the corresponding phase wire is connected to the grid. When there is a fault, the coil switch unit 4 can disconnect the grid-connected relay according to the first coil control signal. When a fault occurs in the energy storage inverter circuit, the second switch unit 3 can also generate a second coil control signal according to the second type of control signal to control the grid-connected relay to disconnect, thereby preventing the fault of the energy storage inverter circuit from spreading to the power grid.

[0040] The first preset operating condition means that the first type of control signal cannot be obtained. For example, the controller that generates the first type of control signal is in a scenario where it needs to be reset and upgraded, or shut down, or other scenarios where it needs to exit the working state. The control end of the second switch unit 3 is used to receive the second type of control signal and generate a second coil control signal. In the first preset operating condition, the coil switch unit 4 is used to control the grid-connected relay to maintain the closed state according to the second coil control signal. With this setting, the energy storage inverter circuit can be controlled by the first control unit and the second control unit respectively in the grid-connected or off-grid state. Therefore, when the first control unit does not work, the grid-connected relay can be maintained in the closed state through the first control unit, so that the load connected to the energy storage inverter circuit can be continuously powered, thereby improving the power supply reliability of the energy storage inverter circuit.

[0041] The grid-connected relay control circuit 100 provided in this embodiment inputs the first power supply voltage U1 by setting the potential adjustment unit 1. The potential adjustment unit 1 is respectively connected to the first switch unit 2 and the second switch unit 3 at the first node N1. The first switch unit 2 is used to generate a first coil control signal according to the first type of control signal Grid_Rely_Ctrl K8 / 9 / 2 / 4 / 6 and output it to the first node N1. The second switch unit 3 is used to generate a second coil control signal according to the second type of control signal MCU_RlyHold in the first preset operating condition. The control end of the coil switch unit 4 controls the grid-connected relay to close according to the first coil control signal to achieve grid-connected operation. In the first preset operating condition, the grid-connected relay is controlled to maintain the closed state according to the second coil control signal, so that the power supply reliability of the load can be better improved. In addition, when a fault occurs in the energy storage inverter circuit, both the first control unit and the second control unit can control the grid-connected relay to disconnect in time, which can improve the grid connection safety and reliability of the energy storage inverter circuit.

[0042] Optionally, Figure 2 is a schematic structural diagram of another grid-connected relay control circuit 100 provided by an embodiment of the present invention. On the basis of the above embodiment, see Figure 2 The grid-connected relay control circuit 100 provided by an embodiment of the present invention includes: the first end of the potential adjustment unit 1 is used to input the first power supply voltage U1, the second end of the potential adjustment unit 1 is connected to the ground terminal, the control end of the potential adjustment unit 1 is used to input the MCU power signal, and the output end of the potential adjustment unit 1 is used to output the first power supply voltage U1 when the MCU power signal MCU_Rly12V is a first-level signal.

[0043] Specifically, the control terminal of the potential regulating unit 1 is turned on or off according to the MCU power supply signal. When the MCU power supply signal is the first level signal, the potential regulating unit 1 outputs the first power supply voltage U1 to the first node N1. When the MCU power supply signal is the second level signal, the potential regulating unit 1 outputs the ground signal to the first node N1. The first level signal is, for example, a high level signal, and the second level signal is, for example, a low level signal. With such a setting, it is possible to control whether the potential regulating unit 1 outputs the first power supply voltage U1 to the first node N1 according to the MCU power supply signal.

[0044] Optionally, Figure 3 is a schematic structural diagram of another grid-connected relay control circuit 100 provided by an embodiment of the present invention. On the basis of the above embodiment, refer to Figure 3 , the potential regulating unit 1 includes: a first switching tube Q9, a second switching tube Q3, a first voltage dividing network, and a second voltage dividing network; the first end of the first voltage dividing network is used to input the MCU power supply signal MCU_Rly12V, the second end of the first voltage dividing network is connected to the control electrode of the first switching tube Q9, the third end of the first voltage dividing network is connected to the first electrode of the first switching tube Q9 and the ground terminal, the second end of the first switching tube Q9 is connected to the first end of the second voltage dividing network, the second end of the second voltage dividing network is connected to the control electrode of the second switching tube Q3, the third end of the second voltage dividing network is connected to the first electrode of the second switching tube Q3 and inputs the first power supply voltage U1, and the second electrode of the second switching tube Q3 is connected to the first node N1; when the MCU power supply signal MCU_Rly12V is the first level signal, such as a high level, the first switching tube Q9 is used to conduct according to the first level signal of the MCU power supply signal MCU_Rly12V, the second switching tube Q3 is used to conduct according to the ground signal, and the potential of the first node N1 is controlled to be the first power supply voltage U1; when the MCU power supply signal MCU_Rly12V is the second level signal, such as a low level, the first switching tube Q9 is used to turn off according to the second level signal of the MCU power supply signal MCU_Rly12V, control the second switching tube Q3 to turn off, and control the potential of the first node N1 to be zero.

[0045] Specifically, the first voltage dividing network includes a first voltage dividing resistor R18 and a second voltage dividing resistor R26. The first end of the first voltage dividing resistor R18 serves as the first end of the first voltage dividing network and is used to input the MCU power supply signal. The second end of the first voltage dividing resistor R18 is connected to the first end of the second voltage dividing resistor R26, serving as the second end of the first voltage dividing network. The second end of the second voltage dividing resistor R26 serves as the third end of the first voltage dividing network. When the MCU power supply signal MCU_Rly12V is a first level signal, the first switching transistor Q9 is used to conduct according to the first level signal of the MCU power supply signal MCU_Rly12V, and the ground signal is transmitted to the first end of the second voltage dividing network, causing the second switching transistor Q3 to conduct, and a first power supply voltage U1 is output at the first node N1. When the MCU power supply signal MCU_Rly12V is a second level signal, the first switching transistor Q9 is used to turn off according to the second level signal of the MCU power supply signal MCU_Rly12V, so that there is no ground signal at the control end of the second switching transistor Q3, controlling the second switching transistor Q3 to turn off, and there is no first power supply voltage U1 at the first node N1.

[0046] The second voltage dividing network includes a third voltage dividing resistor R11 and a fourth voltage dividing resistor R10. The first end of the third voltage dividing resistor R11 serves as the first end of the second voltage dividing network. The second end of the third voltage dividing resistor R11 is connected to the first end of the fourth voltage dividing resistor R10, serving as the second end of the second voltage dividing network. The second end of the fourth voltage dividing resistor R10 serves as the third end of the second voltage dividing network.

[0047] Exemplarily, the first switching transistor Q9 may include a triode or a MOS transistor, etc. The second switching transistor Q3 may include a triode or a MOS transistor. When the first switching transistor Q9 is an NPN type triode, the second switching transistor Q3 may be a PNP type triode. Alternatively, when the first switching transistor Q9 is a PNP type triode, the second switching transistor Q3 may be set as an NPN type triode.

[0048] Optionally, on the basis of the above embodiments, continue to refer to Figure 3, the first end of the first switching unit 2 is connected to the ground terminal, and the second end of the first switching unit 2 is connected to the output terminal of the potential adjustment unit 1 and the control terminal of the coil switching unit 4 at the first node N1; the control terminal of the first switching unit 2 is used to input the first type of control signal, and the first type of control signal includes the first type of control signal Grid_Rely_Ctrl K8 on the inverter side and the first type of control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6 on the grid side; the first switching unit 2 is used to adjust the potential of the first node N1 according to the first type of control signal Grid_Rely_Ctrl K8 on the inverter side, so as to adjust the conduction state of the inverter side sub-relay of the grid-connected relay through the coil switching unit 4; and adjust the potential of the first node N1 according to the first type of control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6 on the grid side, so as to adjust the conduction state of the grid side sub-relay of the grid-connected relay through the coil switching unit 4; the first coil control signal is the level signal output by the first switching unit 2.

[0049] Specifically, the grid-connected relay includes an inverter side sub-relay and a grid side sub-relay. The first switching unit 2 can adjust the potential of the first node N1 according to the first type of control signal on the inverter side. Since the first node N1 is connected to the control terminal of the coil switching unit 4, by adjusting the potential of the first node N1, when the coil switching unit 4 is turned on, the inverter side sub-relay is powered on and turned on, and the inverter side sub-relay of the grid-connected relay is closed.

[0050] The first switching unit 2 can adjust the potential of the first node N1 according to the first type of control signal on the grid side. Since the first node N1 is connected to the control terminal of the coil switching unit 4, by adjusting the potential of the first node N1, when the coil switching unit 4 is turned on, the grid side sub-relay is powered on and turned on, and the grid side sub-relay of the grid-connected relay is closed.

[0051] Optionally, on the basis of the above embodiments, continue to refer to Figure 3, the first switching unit 2 includes: a first DSP switching component 21 and a second DSP switching component 22; the output end of the first DSP switching component 21 is connected to the inverter-side sub-relay of the grid-connected relay through the coil switching unit 4, the first end of the first DSP switching component 21 is connected to the first node N1, the second end of the first DSP switching component 21 is connected to the ground end, and the control end of the first DSP switching component 21 is used to input the inverter-side first type of control signal Grid_Rely_Ctrl K8 of the first type of control signal. The first DSP switching component 21 is used to adjust the potential of the first node N1 according to the inverter-side first type of control signal Grid_Rely_Ctrl K8, and through the coil switching unit 4, adjust the conduction state of the inverter-side sub-relay of the grid-connected relay. The output end of the second DSP switching component 22 is connected to the grid-side sub-relay of the grid-connected relay through the coil switching unit 4, the first end of the second DSP switching component 22 is connected to the first node N1, the second end of the second DSP switching component 22 is connected to the ground end, and the control end of the second DSP switching component 22 is used to input the grid-side first type of control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6 of the first type of control signal. The second DSP switching component 22 is used to adjust the potential of the first node N1 according to the grid-side first type of control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6, and through the coil switching unit 4, adjust the conduction state of the grid-side sub-relay of the grid-connected relay.

[0052] Specifically, the input end of the first DSP switching component 21 is used to input the inverter-side first type of control signal. The first DSP switching component 21 adjusts the potential of the first node N1 according to the inverter-side first type of control signal input at its control end, and outputs an inverter-side first coil control signal. When the inverter-side first coil control signal controls the coil switching unit 4 to conduct, the inverter-side sub-relay of the grid-connected relay is powered on and conducts.

[0053] The control end of the second DSP switching component 22 is used to input the grid-side first type of control signal Grid_Rely_CtrlK9 / 2 / 4 / 6. The second DSP switching component 22 adjusts the potential of the first node N1 according to the grid-side first type of control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6 input at its control end, and through the coil switching unit 4, adjusts the conduction state of the grid-side sub-relay of the grid-connected relay.

[0054] Optionally, on the basis of the above embodiment, continue to refer to Figure 3, the first DSP switch component 21 includes: a third switch transistor Q10, a first resistor R3, and a third voltage dividing network; the first end of the third voltage dividing network is used to input the first type of control signal Grid_Rely_Ctrl K8 on the inverter side, the second end of the third voltage dividing network is connected to the control electrode of the third switch transistor Q10, the third end of the third voltage dividing network is connected to the first electrode of the third switch transistor Q10 and the ground terminal, and the second electrode of the third switch transistor Q10 is connected to the first node N1; the first resistor R3 is connected between the second electrode of the third switch transistor Q10 and the first node N1, and the second electrode of the third switch transistor Q10 serves as the output terminal of the first DSP switch component 21; the third switch transistor Q10 is used to conduct when the first type of control signal Grid_Rely_Ctrl K8 on the inverter side is a first level signal, adjust the potential of the output terminal of the first DSP switch component 21 to zero, and through the coil switch unit 4, adjust the inverter side sub-relay of the grid-connected relay to disconnect; the third switch transistor Q10 is also used to turn off when the first type of control signal Grid_Rely_Ctrl K8 on the inverter side is a second level signal, control the potential of the output terminal of the first DSP switch component 21 to maintain the first power supply voltage U1, and through the coil switch unit 4, adjust the inverter side sub-relay of the grid-connected relay to close.

[0055] Specifically, the third voltage dividing network includes a fifth voltage dividing resistor R17 and a sixth voltage dividing resistor R24. The first end of the fifth voltage dividing resistor R17 serves as the first end of the third voltage dividing network and is used to input the first type of control signal Grid_Rely_Ctrl K8 on the inverter side. The second end of the fifth voltage dividing resistor R17 is connected to the first end of the sixth voltage dividing resistor R24 and serves as the second end of the third voltage dividing network. The second end of the sixth voltage dividing resistor R24 serves as the third end of the third voltage dividing network. When the first type of control signal Grid_Rely_Ctrl K8 on the inverter side is a first level signal, the third switch transistor Q10 is used to conduct according to the first level signal of the first type of control signal Grid_Rely_Ctrl K8 on the inverter side, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the first DSP switch component 21 is zero, and through the coil switch unit 4, the inverter side sub-relay of the grid-connected relay is adjusted to disconnect.

[0056] When the first type of control signal Grid_Rely_Ctrl K8 on the inverter side is a second level signal, the third switch transistor Q10 is used to turn off according to the second level signal of the first type of control signal Grid_Rely_Ctrl K8 on the inverter side, and the first power supply voltage U1 is output from the first node N1 through the first resistor R3. Thereby, the potential of the output terminal of the first DSP switch component 21 is controlled to maintain the first power supply voltage U1, and through the coil switch unit 4, the inverter side sub-relay of the grid-connected relay is adjusted to close.

[0057] Exemplarily, the third switching transistor Q10 may include a bipolar transistor or a MOS transistor, etc. The third switching transistor Q10 may be of P-type or N-type, and no limitation is made here.

[0058] Optionally, based on the above embodiments, continue to refer to Figure 3 , the second DSP switching component 22 may include: an N-phase DSP switching circuit 221, an A-phase DSP switching circuit 222, a B-phase DSP switching circuit 223, and a C-phase DSP switching circuit 224; the first type of grid-side control signal Grid_Rely_Ctrl K9 / 2 / 4 / 6 includes: a first grid-side first type of control signal Grid_Rely_Ctrl K9, a second grid-side first type of control signal Grid_Rely_Ctrl K2, a third grid-side first type of control signal Grid_Rely_Ctrl K4, and a fourth grid-side first type of control signal Grid_Rely_Ctrl K6.

[0059] The control terminal of the N-phase DSP switching circuit 221 is used to input the first grid-side first type of control signal Grid_Rely_Ctrl K9. The first terminal of the N-phase DSP switching circuit 221 is connected to the ground terminal. The second terminal of the N-phase DSP switching circuit 221 is connected to the first node N1. The output terminal of the N-phase DSP switching circuit 221 is connected to the N-phase grid-side switching component of the coil switching unit 4. The N-phase DSP switching circuit 221 is configured to output a first level signal when the first grid-side first type of control signal is a second level signal, and control the N-phase grid-side switching component of the coil switching unit 4 to conduct, and control the N-phase grid-side sub-relay to close; when the first grid-side first type of control signal is a first level signal, output a second level signal, and control the N-phase grid-side switching component of the coil switching unit 4 to disconnect, and control the N-phase grid-side sub-relay to disconnect.

[0060] The A-phase DSP switching circuit 222 is used to input the second grid-side first type of control signal Grid_Rely_Ctrl K2. The first terminal of the A-phase DSP switching circuit 222 is connected to the ground terminal. The second terminal of the A-phase DSP switching circuit 222 is connected to the first node N1. The output terminal of the A-phase DSP switching circuit 222 is connected to the A-phase grid-side switching component of the coil switching unit 4. The A-phase DSP switching circuit 222 is configured to output a first level signal when the first grid-side first type of control signal is a second level signal, and control the A-phase grid-side switching component of the coil switching unit 4 to conduct, and control the A-phase grid-side sub-relay to close; when the second grid-side first type of control signal is a first level signal, output a second level signal, and control the A-phase grid-side switching component of the coil switching unit 4 to disconnect, and control the A-phase grid-side sub-relay to disconnect.

[0061] The B-phase DSP switch circuit 223 is used to input the first type of control signal Grid_Rely_Ctrl K4 on the third grid side. The first end of the B-phase DSP switch circuit 223 is connected to the ground terminal, the second end of the B-phase DSP switch circuit 223 is connected to the first node N1, and the output end of the B-phase DSP switch circuit 223 is connected to the B-phase grid-side switch component of the coil switch unit 4. The B-phase DSP switch circuit 223 is used to output a first-level signal and control the conduction of the B-phase grid-side switch component of the coil switch unit 4 when the first type of control signal on the third grid side is a second-level signal, and control the closing of the B-phase grid-side sub-relay; when the first type of control signal on the third grid side is a first-level signal, output a second-level signal and control the disconnection of the B-phase grid-side switch component of the coil switch unit 4, and control the disconnection of the B-phase grid-side sub-relay.

[0062] The C-phase DSP switch circuit 224 is used to input the first type of control signal Grid_Rely_Ctrl K6 on the fourth grid side. The first end of the C-phase DSP switch circuit 224 is connected to the ground terminal, the second end of the C-phase DSP switch circuit 224 is connected to the first node N1, and the output end of the C-phase DSP switch circuit 224 is connected to the C-phase grid-side switch component of the coil switch unit 4. The C-phase DSP switch circuit 224 is used to output a first-level signal and control the conduction of the C-phase grid-side switch component of the coil switch unit 4 when the first type of control signal on the fourth grid side is a second-level signal, and control the closing of the C-phase grid-side sub-relay; when the first type of control signal on the fourth grid side is a first-level signal, output a second-level signal and control the disconnection of the C-phase grid-side switch component of the coil switch unit 4, and control the disconnection of the C-phase grid-side sub-relay.

[0063] Specifically, since there is no current flowing through the N-phase line during grid connection, the N-phase grid-side sub-relay connected to the N-phase of the first node N1 can be closed first, which can not only achieve the closing of the N-phase grid-side sub-relay, but also prevent arcing or thermal runaway of the grid-side sub-relay connected to the N-phase. Without affecting the service life of the grid connection relay, the control efficiency of the grid connection relay is improved.

[0064] With such a setting, it is convenient to first close the N-phase grid-side sub-relay of the grid connection relay connected to the N-phase of the first node N1, and then obtain the first voltage of at least one of the ABC three-phase voltages of the second node N2. According to the difference between the first voltage and the zero voltage, control the closing of the grid-side sub-relay at the zero crossing. With such a setting, the grid-side sub-relay of the grid connection relay whose phase line where the amplitude of the first voltage is equal to the zero voltage can be closed separately when there is no current flowing through the contact, thus avoiding arcing when the grid-side sub-relay of the grid connection relay is closed, improving the thermal stability of the grid connection relay, and thus extending the service life of the grid connection relay.

[0065] Optionally, based on the above embodiments, continue to refer to Figure 3 , the N-phase DSP switch circuit 221 includes a fourth switching transistor Q13, a fourth voltage dividing network, and a second resistor R4; the first end of the fourth voltage dividing network is used to input the first type of control signal Grid_Rely_Ctrl K9 of the first grid side, the second end of the fourth voltage dividing network is connected to the control electrode of the fourth switching transistor Q13, the third end of the fourth voltage dividing network is connected to the first electrode of the fourth switching transistor Q13 and the ground terminal, the second electrode of the fourth switching transistor Q13 serves as the output terminal of the N-phase DSP switch circuit 221, and the second resistor R4 is connected between the second electrode of the fourth switching transistor Q13 and the first node N1.

[0066] The A-phase DSP switch circuit 222 includes a fifth switching transistor Q14, a fifth voltage dividing network, and a third resistor R5; the first end of the fifth voltage dividing network is used to input the first type of control signal Grid_Rely_Ctrl K2 of the second grid side, the second end of the fifth voltage dividing network is connected to the control electrode of the fifth switching transistor Q14, the third end of the fifth voltage dividing network is connected to the first electrode of the fifth switching transistor Q14 and the ground terminal, the second electrode of the fifth switching transistor Q14 serves as the output terminal of the A-phase DSP switch circuit 222, and the third resistor R5 is connected between the second electrode of the fifth switching transistor Q14 and the first node N1.

[0067] The B-phase DSP switch circuit 223 includes a sixth switching transistor Q15, a sixth voltage dividing network, and a fourth resistor R6; the first end of the sixth voltage dividing network is used to input the first type of control signal Grid_Rely_Ctrl K4 of the third grid side, the second end of the sixth voltage dividing network is connected to the control electrode of the sixth switching transistor Q15, the third end of the sixth voltage dividing network is connected to the first electrode of the sixth switching transistor Q15 and the ground terminal, the second electrode of the sixth switching transistor Q15 serves as the output terminal of the B-phase DSP switch circuit 223, and the fourth resistor R6 is connected between the second electrode of the sixth switching transistor Q15 and the first node N1.

[0068] The C-phase DSP switch circuit 224 includes a seventh switching transistor Q16, a seventh voltage dividing network, and a fifth resistor R7; the first end of the seventh voltage dividing network is used to input the first type of control signal Grid_Rely_Ctrl K6 of the fourth grid side, the second end of the seventh voltage dividing network is connected to the control electrode of the seventh switching transistor Q16, the third end of the seventh voltage dividing network is connected to the first electrode of the seventh switching transistor Q16 and the ground terminal, the second electrode of the seventh switching transistor Q16 serves as the output terminal of the C-phase DSP switch circuit 224, and the fifth resistor R7 is connected between the second electrode of the seventh switching transistor Q16 and the first node N1.

[0069] Specifically, the fourth voltage dividing network includes a seventh voltage dividing resistor R31 and an eighth voltage dividing resistor R36. The first end of the seventh voltage dividing resistor R31 serves as the first end of the fourth voltage dividing network and is used to input the first type of control signal Grid_Rely_Ctrl K9 on the first grid side. The second end of the seventh voltage dividing resistor R31 is connected to the first end of the eighth voltage dividing resistor R36, serving as the second end of the fourth voltage dividing network. The second end of the eighth voltage dividing resistor R36 serves as the third end of the fourth voltage dividing network. The second end of the fourth voltage dividing network is connected to the control electrode of the fourth switching transistor Q13, and the third end of the fourth voltage dividing network is connected to the first electrode of the fourth switching transistor Q13 and the ground terminal. The second electrode of the fourth switching transistor Q13 serves as the output terminal of the N-phase DSP switching circuit 221, and the second resistor R4 is connected between the second electrode of the fourth switching transistor Q13 and the first node N1. When the first type of control signal Grid_Rely_Ctrl K9 on the first grid side is a first level signal, the fourth switching transistor Q13 is used to conduct according to the first level signal of the first type of control signal Grid_Rely_Ctrl K9 on the first grid side, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the N-phase DSP switching circuit 221 is zero, and the N-phase grid side sub-relay of the grid connection relay is adjusted to be disconnected through the coil switching unit 4. When the first type of control signal Grid_Rely_Ctrl K9 on the first grid side is a second level signal, the fourth switching transistor Q13 is used to turn off according to the second level signal of the first type of control signal Grid_Rely_Ctrl K9 on the first grid side, and the first power supply voltage U1 outputs from the first node N1 through the second resistor R4. Thus, the potential of the output terminal of the N-phase DSP switching circuit 221 of the second DSP switching component 22 is controlled to maintain the first power supply voltage U1, such as 12V, and the N-phase grid side sub-relay of the grid connection relay is adjusted to be closed through the corresponding coil switching unit 4.

[0070] Exemplarily, the fourth switching transistor Q13 may include a triode or a MOS transistor, etc. The fourth switching transistor Q13 may include a P-type or an N-type, and no limitation is made here.

[0071] Further, the fifth voltage dividing network includes a ninth voltage dividing resistor R32 and a tenth voltage dividing resistor R37. The first end of the ninth voltage dividing resistor R32 serves as the first end of the fifth voltage dividing network and is used to input the first type of control signal Grid_Rely_Ctrl K2 on the second grid side. The second end of the ninth voltage dividing resistor R32 is connected to the first end of the tenth voltage dividing resistor R37, serving as the second end of the fifth voltage dividing network. The second end of the tenth voltage dividing resistor R37 serves as the third end of the fifth voltage dividing network. The second end of the fifth voltage dividing network is connected to the control electrode of the fifth switching transistor Q14, and the third end of the fifth voltage dividing network is connected to the first electrode of the fifth switching transistor Q14 and the ground terminal. The second electrode of the fifth switching transistor Q14 serves as the output terminal of the A-phase DSP switching circuit 222. The third resistor R5 is connected between the second electrode of the fifth switching transistor Q14 and the first node N1. When the first type of control signal Grid_Rely_Ctrl K2 on the second grid side is a first level signal, the fifth switching transistor Q14 is used to conduct according to the first level signal of the first type of control signal Grid_Rely_Ctrl K2 on the second grid side, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the A-phase DSP switching circuit 222 is zero, and the A-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switching unit 4. When the first type of control signal Grid_Rely_Ctrl K2 on the second grid side is a second level signal, the fifth switching transistor Q14 is used to turn off according to the second level signal of the first type of control signal Grid_Rely_Ctrl K2 on the second grid side, and the first power supply voltage U1 is output from the first node N1 through the third resistor R5. Thus, the potential of the output terminal of the A-phase DSP switching circuit 222 of the second DSP switching component 22 is controlled to maintain the first power supply voltage U1, and the A-phase grid-side sub-relay of the grid-connected relay is adjusted to be closed through the corresponding coil switching unit 4.

[0072] Exemplarily, the fifth switching transistor Q14 may include a triode or a MOS transistor, etc. The type of the fifth switching transistor Q14 may include P-type or N-type, and no limitation is made here.

[0073] Further, the sixth voltage dividing network includes the eleventh voltage dividing resistor R33 and the twelfth voltage dividing resistor R38. The first end of the eleventh voltage dividing resistor R33 serves as the first end of the sixth voltage dividing network for inputting the first type of control signal Grid_Rely_Ctrl K2 on the third grid side. The second end of the eleventh voltage dividing resistor R33 is connected to the first end of the twelfth voltage dividing resistor R38, serving as the second end of the sixth voltage dividing network. The second end of the twelfth voltage dividing resistor R38 serves as the third end of the sixth voltage dividing network. The second end of the sixth voltage dividing network is connected to the control electrode of the sixth switching transistor Q15, and the third end of the sixth voltage dividing network is connected to the first electrode of the sixth switching transistor Q15 and the ground terminal. The second electrode of the sixth switching transistor Q15 serves as the output terminal of the B-phase DSP switching circuit 223, and the fourth resistor R6 is connected between the second electrode of the sixth switching transistor Q15 and the first node N1. When the first type of control signal Grid_Rely_Ctrl K2 on the third grid side is a first-level signal, the sixth switching transistor Q15 is used to conduct according to the first-level signal of the first type of control signal Grid_Rely_Ctrl K2 on the third grid side, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the B-phase DSP switching circuit 223 is zero, and the B-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switching unit 4. When the first type of control signal Grid_Rely_Ctrl K4 on the third grid side is a second-level signal, the sixth switching transistor Q15 is used to turn off according to the second-level signal of the first type of control signal Grid_Rely_Ctrl K4 on the third grid side, and the first power supply voltage U1 is output from the first node N1 through the fourth resistor R6. Thus, the potential of the output terminal of the B-phase DSP switching circuit 223 of the second DSP switching component 22 is controlled to maintain the first power supply voltage U1, and the B-phase grid-side sub-relay of the grid-connected relay is adjusted to be closed through the corresponding coil switching unit 4.

[0074] Exemplarily, the sixth switching transistor Q15 may include a triode or a MOS transistor, etc. The type of the sixth switching transistor Q15 may include P-type or N-type, and no limitation is made here.

[0075] Further, the seventh voltage dividing network includes a thirteenth voltage dividing resistor R34 and a fourteenth voltage dividing resistor R39. The first end of the thirteenth voltage dividing resistor R34 serves as the first end of the seventh voltage dividing network and is used to input a fourth grid-side first type of control signal Grid_Rely_Ctrl K6. The second end of the thirteenth voltage dividing resistor R34 is connected to the first end of the fourteenth voltage dividing resistor R39 and serves as the second end of the seventh voltage dividing network. The second end of the fourteenth voltage dividing resistor R39 serves as the third end of the seventh voltage dividing network. The second end of the seventh voltage dividing network is connected to the control electrode of the seventh switching transistor Q16. The third end of the seventh voltage dividing network is connected to the first electrode of the seventh switching transistor Q16 and the ground terminal. The second electrode of the seventh switching transistor Q16 serves as the output terminal of the C-phase DSP switching circuit 224. The fifth resistor R7 is connected between the second electrode of the seventh switching transistor Q16 and the first node N1. When the fourth grid-side first type of control signal Grid_Rely_Ctrl K6 is a first level signal, the seventh switching transistor Q16 is used to conduct according to the first level signal of the fourth grid-side first type of control signal Grid_Rely_Ctrl K6, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the C-phase DSP switching circuit 224 is zero, and the C-phase grid-side sub-relay of the grid connection relay is adjusted to be disconnected through the coil switching unit 4. When the fourth grid-side first type of control signal Grid_Rely_Ctrl K6 is a second level signal, the seventh switching transistor Q16 is used to turn off according to the second level signal of the fourth grid-side first type of control signal Grid_Rely_Ctrl K6, and the first power supply voltage U1 is output from the first node N1 through the fifth resistor R7. Thus, the potential of the output terminal of the C-phase DSP switching circuit 224 of the second DSP switching component 22 is controlled to maintain the first power supply voltage U1, and the C-phase grid-side sub-relay of the grid connection relay is adjusted to be closed through the corresponding coil switching unit 4.

[0076] Exemplarily, the seventh switching transistor Q16 may include a triode or a MOS transistor, etc. The type of the seventh switching transistor Q16 may include P-type or N-type, and no limitation is made here.

[0077] Optionally, on the basis of the above embodiments, continue to refer to Figure 3 , the control terminal of the second switching unit 3 is used to input an MCU hold signal MCU_RlyHold. The first end of the second switching unit 3 is used to input the first power supply voltage U1. The second end of the second switching unit 3 is connected to the ground terminal. The third end of the second switching unit 3 is connected to the first node N1. The second switching unit 3 is used to generate a first level signal when the MCU hold signal is the second level signal MCU_RlyHold, and generate a second level signal when the MCU hold signal output by the MCU sampling controller is the first level signal MCU_RlyHold; the second coil control signal is the level signal output by the second switching unit 3.

[0078] Specifically, the second switch unit 3 is used to maintain the grid-connected relay in a closed state when the first switch unit 2 is in a preset operating condition. The first switch unit 2 or the second switch unit 3 is also used to control the grid-connected relay to cut off power according to the fault state of the grid-connected relay control device or the energy storage inverter circuit when the grid-connected relay control device or the energy storage inverter circuit fails.

[0079] Optionally, on the basis of the above embodiments, continue to refer to Figure 3 , the second switch unit 3 may include: an MCU potential regulating component 31, an inverter-side relay control component 32, and a grid-side relay control component 33; a control signal MCU_RlyHold of the second type is input to the control end of the MCU potential regulating component 31, a first power supply voltage U1 is input to the first end of the MCU potential regulating component 31, the second end of the MCU potential regulating component 31 is connected to the ground terminal, and the output end of the MCU potential regulating component 31 is connected to the control ends of the inverter-side relay control component 32 and the grid-side relay control component 33 at a second node N2; the MCU potential regulating component 31 is used to generate a second-level signal when the second-level control signal MCU_RlyHold is a second-level signal under a first preset operating condition; and generate a first-level signal when the second-level control signal MCU_RlyHold is a first-level signal.

[0080] The first end of the inverter-side relay control component 32 is connected to the ground terminal, the second end of the inverter-side relay control component 32 is connected to a first node N1, and the output end of the inverter-side relay control component 32 is connected to an inverter-side switch component 411 of the coil switch unit 4; the inverter-side relay control component 32 is used to control the inverter-side relay to conduct through the inverter-side switch component 411 according to the first-level signal of the second node N2, and control the inverter-side relay to disconnect through the inverter-side switch component 411 according to the second-level signal of the second node N2.

[0081] The first end of the grid-side relay control component 33 is connected to the ground terminal, the second end of the grid-side relay control component 33 is connected to a first node N1, and the output end of the grid-side relay control component 33 is connected to a grid-side switch component of the coil switch unit 4; the grid-side relay control component 33 is used to control the grid-side relay to conduct through the grid-side switch component according to the first-level signal of the second node N2, and control the grid-side relay to disconnect through the grid-side switch component according to the second-level signal of the second node N2.

[0082] Specifically, the MCU potential regulating component 31 outputs the first power supply voltage U1 input at the first end of the MCU potential regulating component 31 or the ground signal at the second end of the MCU potential regulating component 31 to the second node N2 according to the second type of control signal MCU_RlyHold input at its control end, and then outputs it to the control ends of the inverter-side relay control component 32 and the grid-side relay control component 33. The first preset working condition refers to the working condition when active shutdown is required or shutdown is necessary due to a fault, or when grid-connected and off-grid switching is required, or when the DSP control unit connected to the first switch unit 2 needs program upgrade and reset, and at this time the grid is normal and the energy storage inverter circuit is connected to a load. Under the first preset working condition, when the second type of control signal MCU_RlyHold is a second-level signal, the MCU potential regulating component 31 outputs a second-level signal; when the second type of control signal MCU_RlyHold is a first-level signal, the MCU potential regulating component 31 outputs a first-level signal. The control signal output by the MCU potential regulating component 31 to the second node N2 is MCU_GridRlyCtr_Hold.

[0083] The control end of the inverter-side relay control component 32 is connected to the output end of the MCU potential regulating component 31. The first end of the inverter-side relay control component 32 is connected to the ground end, the second end of the inverter-side relay control component 32 is connected to the first node N1, and the output end of the inverter-side relay control component 32 is connected to the inverter-side switch component 411 of the coil switch unit 4. The inverter-side relay control component 32 controls the conduction of the inverter-side relay through the inverter-side switch component 411 according to the first-level signal of the second node N2 to control the power-on of the inverter-side relay. The inverter-side relay control component 32 also controls the disconnection of the inverter-side relay through the inverter-side switch component 411 according to the second-level signal of the second node N2.

[0084] The control end of the grid-side relay control component 33 is connected to the output end of the MCU potential regulating component 31. The first end of the grid-side relay control component 33 is connected to the ground end. The second end of the grid-side relay control component 33 is connected to the first node N1, and the output end of the grid-side relay control component 33 is connected to the grid-side switch component of the coil switch unit 4. The grid-side relay control component 33 controls the conduction of each grid-side relay respectively through the corresponding grid-side switch component according to the first-level signal of the second node N2. The grid-side relay control component 33 controls the disconnection of the grid-side relay through the grid-side switch component according to the second-level signal of the second node N2.

[0085] Optionally, on the basis of the above embodiments, continue to refer to Figure 3, the structure of the MCU potential regulation component 31 is the same as that of the potential regulation unit 1. The structure of the inverter-side relay control component 32 is the same as that of the first DSP switch component 21. Such an arrangement simplifies the circuit structure and saves design and manufacturing costs.

[0086] An optionally implemented manner. Based on the above embodiments, continue to refer to Figure 3 , this embodiment provides a structure of the MCU potential regulation component 31. The MCU potential regulation component 31 may include: a sixteenth switch tube Q17, a seventeenth switch tube Q12, a sixteenth voltage division network, and a seventeenth voltage division network; the first end of the sixteenth voltage division network is used to input the MCU hold signal MCU_RlyHold, the second end of the sixteenth voltage division network is connected to the control electrode of the sixteenth switch tube Q17, the third end of the sixteenth voltage division network is connected to the first electrode of the sixteenth switch tube Q17 and the ground terminal, the second end of the sixteenth switch tube Q17 is connected to the first end of the seventeenth voltage division network, the second end of the seventeenth voltage division network is connected to the control electrode of the seventeenth switch tube Q12, the third end of the seventeenth voltage division network is connected to the first electrode of the seventeenth switch tube Q12 and inputs the first power supply voltage U1, and the second electrode of the seventeenth switch tube Q12 is connected to the second node N2; when the MCU hold signal MCU_RlyHold is a first-level signal, the sixteenth switch tube Q17 is used to conduct according to the first-level signal of the MCU hold signal MCU_RlyHold, the seventeenth switch tube Q12 is used to conduct according to the ground signal, and the potential of the second node N2 is controlled to be the first power supply voltage U1; when the MCU hold signal MCU_RlyHold is a second-level signal, the sixteenth switch tube Q17 is used to turn off according to the second-level signal of the MCU hold signal MCU_RlyHold, control the seventeenth switch tube Q12 to turn off, and control the potential of the second node N2 to be zero.

[0087] Specifically, the sixteenth voltage dividing network includes a thirty-first voltage dividing resistor R35 and a thirty-second voltage dividing resistor R40. The first end of the thirty-first voltage dividing resistor R35 serves as the first end of the sixteenth voltage dividing network and is used to input the MCU power supply signal. The second end of the thirty-first voltage dividing resistor R35 is connected to the first end of the thirty-second voltage dividing resistor R40 and serves as the second end of the sixteenth voltage dividing network. The second end of the thirty-second voltage dividing resistor R40 serves as the third end of the sixteenth voltage dividing network. When the MCU holding signal MCU_RlyHold is at the first level signal, the sixteenth switching transistor Q17 is used to conduct according to the first level signal of the MCU holding signal MCU_RlyHold, and the ground signal is transmitted to the first end of the seventeenth voltage dividing network, causing the seventeenth switching transistor Q12 to conduct, and a first power supply voltage U1 is output at the second node N2. When the MCU holding signal MCU_RlyHold is at the second level signal, the sixteenth switching transistor Q17 is used to turn off according to the second level signal of the MCU holding signal MCU_RlyHold, so that there is no ground signal at the control end of the seventeenth switching transistor Q12, controlling the seventeenth switching transistor Q12 to turn off, and there is no first power supply voltage U1 at the second node N2.

[0088] The seventeenth voltage dividing network includes a thirty-third voltage dividing resistor R30 and a thirty-fourth voltage dividing resistor R28. The first end of the thirty-third voltage dividing resistor R30 serves as the first end of the seventeenth voltage dividing network. The second end of the thirty-third voltage dividing resistor R30 is connected to the first end of the thirty-fourth voltage dividing resistor R28 and serves as the second end of the seventeenth voltage dividing network. The second end of the thirty-fourth voltage dividing resistor R28 serves as the third end of the seventeenth voltage dividing network.

[0089] Exemplarily, the sixteenth switching transistor Q17 may include a triode or a MOS transistor, etc. The seventeenth switching transistor Q12 may include a triode or a MOS transistor. When the sixteenth switching transistor Q17 is an NPN type triode, the seventeenth switching transistor Q12 may be a PNP type triode. Or, when the sixteenth switching transistor Q17 is a PNP type triode, the seventeenth switching transistor Q12 may be set as an NPN type triode.

[0090] Another alternative implementation manner, on the basis of the above embodiments, continue to refer to Figure 3, this embodiment provides a structure of the inverter-side relay control component 32. The inverter-side relay control component 32 may include: the eighteenth switching tube Q8, the first resistor R3, and the eighteenth voltage dividing network; the first end of the eighteenth voltage dividing network is used to input the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, the second end of the eighteenth voltage dividing network is connected to the control electrode of the eighteenth switching tube Q8, the third end of the eighteenth voltage dividing network is connected to the first pole of the eighteenth switching tube Q8 and the ground terminal, and the second pole of the eighteenth switching tube Q8 is connected to the first node N1; the first resistor R3 is connected between the second pole of the eighteenth switching tube Q8 and the first node N1, and the second pole of the eighteenth switching tube Q8 serves as the output terminal of the inverter-side relay control component 32; the eighteenth switching tube Q8 is used to conduct when the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first-level signal, adjust the potential of the output terminal of the inverter-side relay control component 32 to zero, and through the coil switching unit 4, adjust the inverter-side sub-relay of the grid-connected relay to disconnect; the eighteenth switching tube Q8 is further used to disconnect when the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a second-level signal, control the potential of the output terminal of the inverter-side relay control component 32 to maintain the first power supply voltage U1, and through the coil switching unit 4, adjust the inverter-side sub-relay of the grid-connected relay to close.

[0091] Specifically, the eighteenth voltage dividing network includes the thirty-fifth voltage dividing resistor R16 and the thirty-sixth voltage dividing resistor R23. The first end of the thirty-fifth voltage dividing resistor R16 serves as the first end of the eighteenth voltage dividing network and is used to input the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2. The second end of the thirty-fifth voltage dividing resistor R16 is connected to the first end of the thirty-sixth voltage dividing resistor R23 and serves as the second end of the eighteenth voltage dividing network. The second end of the thirty-sixth voltage dividing resistor R23 serves as the third end of the eighteenth voltage dividing network. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first-level signal, the eighteenth switching tube Q8 is used to conduct according to the first-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the ground signal is transmitted to the first node N1, so that the potential of the output terminal of the inverter-side relay control component 32 is zero, and through the coil switching unit 4, the inverter-side sub-relay of the grid-connected relay is adjusted to disconnect.

[0092] When the control signal MCU_GridRlyCtr_Hold output from the MCU potential regulating component 31 to the second node N2 is a second-level signal, the eighteenth switching transistor Q8 is used to turn off according to the second-level signal of the control signal MCU_GridRlyCtr_Hold output from the MCU potential regulating component 31 to the second node N2, and the first power supply voltage U1 outputs from the first node N1 through the first resistor R3. Thereby, the potential at the output end of the inverter-side relay control component 32 is maintained at the first power supply voltage U1, and the inverter-side sub-relay of the grid-connected relay is adjusted to close through the coil switching unit 4.

[0093] Exemplarily, the eighteenth switching transistor Q8 may include a triode, a MOS transistor, etc. The eighteenth switching transistor Q8 may include a P-type or an N-type, and no limitation is made here.

[0094] Optionally, based on the above embodiments, continue to refer to Figure 3 , the grid-side relay control component 33 includes an N-phase MCU switching circuit 331, an A-phase MCU switching circuit 332, a B-phase MCU switching circuit 333, and a C-phase MCU switching circuit 334.

[0095] The first end of the N-phase MCU switching circuit 331 is connected to the ground terminal, the second end of the N-phase MCU switching circuit 331 is connected to the first node N1, and the output end of the N-phase MCU switching circuit 331 is connected to the N-phase grid-side switching component 412 of the coil switching unit 4; the N-phase MCU switching circuit 331 is used to control the N-phase grid-side sub-relay K9 of the grid-side relay to conduct according to the first-level signal of the second node N2 through the N-phase grid-side switching component 412, and control the N-phase grid-side sub-relay K9 to disconnect according to the second-level signal of the second node N2 through the N-phase grid-side switching component 412.

[0096] The first end of the A-phase MCU switching circuit 332 is connected to the ground terminal, the second end of the A-phase MCU switching circuit 332 is connected to the first node N1, and the output end of the A-phase MCU switching circuit 332 is connected to the N-phase grid-side switching component 412 of the coil switching unit 4; the A-phase MCU switching circuit 332 is used to control the A-phase grid-side sub-relay K2 of the grid-side relay to conduct according to the first-level signal of the second node N2 through the A-phase grid-side switching component 413, and control the A-phase grid-side sub-relay K2 to disconnect according to the second-level signal of the second node N2 through the A-phase grid-side switching component 413.

[0097] The first end of the B-phase MCU switch circuit 333 is connected to the ground terminal, the second end of the B-phase MCU switch circuit 333 is connected to the first node N1, and the output end of the B-phase MCU switch circuit 333 is connected to the B-phase grid-side switch component 414 of the coil switch unit 4; the B-phase MCU switch circuit 333 is configured to control the B-phase grid-side sub-relay K4 of the grid-side relay to conduct according to the first level signal of the second node N2 through the B-phase grid-side switch component 414, and control the B-phase grid-side sub-relay K4 to disconnect according to the second level signal of the second node N2 through the B-phase grid-side switch component 414.

[0098] The first end of the C-phase MCU switch circuit 334 is connected to the ground terminal, the second end of the C-phase MCU switch circuit 334 is connected to the first node N1, and the output end of the C-phase MCU switch circuit 334 is connected to the C-phase grid-side switch component 415 of the coil switch unit 4; the C-phase MCU switch circuit 334 is configured to control the C-phase grid-side sub-relay K6 of the grid-side relay to conduct according to the first level signal of the second node N2 through the C-phase grid-side switch component 415, and control the C-phase grid-side sub-relay K6 to disconnect according to the second level signal of the second node N2 through the C-phase grid-side switch component 415.

[0099] Specifically, since there is no current flowing through the N-phase line during grid connection, the N-phase grid-side sub-relay connected to the N-phase of the first node N1 can be closed first, which can not only achieve the closing of the N-phase grid-side sub-relay, but also prevent arcing or thermal runaway of the grid-side sub-relay connected to the N-phase. Without affecting the service life of the grid connection relay, the control efficiency of the grid connection relay is improved. The closing sequence of the grid-side sub-relay is to first close the N-phase grid-side sub-relay of the grid connection relay connected to the N-phase of the first node N1, and then obtain the first voltage of at least one of the ABC three-phase voltages of the second node N2. According to the difference between the first voltage and the zero voltage, the grid-side sub-relay at the zero crossing point is controlled to close.

[0100] With such a setting, when the grid-side sub-relays close different grid-side sub-relays respectively, they can be correspondingly controlled to remain closed, thereby avoiding arcing when the grid-side sub-relays of the grid connection relay close, further improving the thermal stability of the grid connection relay, and thus extending the service life of the grid connection relay.

[0101] Optionally, on the basis of the above embodiments, continue to refer to Figure 3, the structures of the N-phase MCU switch circuit 331, the A-phase MCU switch circuit 332, the B-phase MCU switch circuit 333, and the C-phase MCU switch circuit 334 are the same. The N-phase MCU switch circuit 331 may include an eighth switching transistor Q4, an eighth voltage dividing network, and a second resistor R4; the first end of the eighth voltage dividing network is connected to the second node N2, serving as the second end of the MCU switch circuit, the second end of the eighth voltage dividing network is connected to the control electrode of the eighth switching transistor Q4, the third end of the eighth voltage dividing network is connected to the first electrode of the eighth switching transistor Q4 and the ground terminal, serving as the first end of the MCU switch circuit, the second electrode of the eighth switching transistor Q4 is connected to the first end of the second resistor R4, serving as the output end of the MCU switch circuit, and the second end of the second resistor R4 is connected to the first node N1, serving as the third end of the MCU switch circuit.

[0102] Specifically, the eighth voltage dividing network includes a fifteenth voltage dividing resistor R12 and a sixteenth voltage dividing resistor R19. The first end of the fifteenth voltage dividing resistor R12 serves as the first end of the eighth voltage dividing network and is connected to the second node N2, serving as the second end of the MCU switch circuit, for inputting the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2. The second end of the fifteenth voltage dividing resistor R12 is connected to the first end of the sixteenth voltage dividing resistor R19, serving as the second end of the eighth voltage dividing network. The second end of the sixteenth voltage dividing resistor R19 serves as the third end of the eighth voltage dividing network. The second end of the eighth voltage dividing network is connected to the control electrode of the eighth switching tube Q4, and the third end of the eighth voltage dividing network is connected to the first electrode of the eighth switching tube Q4 and the ground terminal. The second electrode of the eighth switching tube Q4 serves as the output end of the N-phase MCU switch circuit 331, and the second resistor R4 is connected between the second electrode of the eighth switching tube Q4 and the first node N1. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first level signal, the eighth switching tube Q4 is used to conduct according to the first level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the ground signal is transmitted to the first node N1, so that the potential of the output end of the N-phase MCU switch circuit 331 is zero, and the N-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switch unit 4. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a second level signal, the eighth switching tube Q4 is used to turn off according to the second level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the first power supply voltage U1 is output from the first node N1 through the second resistor R4. Thus, the potential of the output end of the N-phase MCU switch circuit 331 is controlled to maintain the first power supply voltage U1, and the N-phase grid-side sub-relay of the grid-connected relay is adjusted to maintain the closed state through the corresponding coil switch unit 4.

[0103] Exemplarily, the eighth switching tube Q4 may include a triode or a MOS tube, etc. The eighth switching tube Q4 may include a P-type or an N-type, and no limitation is made here.

[0104] An optional implementation manner, continue to refer to Figure 3, exemplarily, the phase-A MCU switch circuit 332 may include a nineteenth switching transistor Q5, a nineteenth voltage dividing network, and a third resistor R5; a first end of the nineteenth voltage dividing network is connected to the second node N2 and serves as the second end of the phase-A MCU switch circuit 332, a second end of the nineteenth voltage dividing network is connected to the control electrode of the nineteenth switching transistor Q5, a third end of the nineteenth voltage dividing network is connected to the first electrode of the nineteenth switching transistor Q5 and the ground terminal and serves as the first end of the phase-A MCU switch circuit 332, a second electrode of the nineteenth switching transistor Q5 is connected to a first end of the third resistor R5 and serves as the output end of the phase-A MCU switch circuit 332, and a second end of the third resistor R5 is connected to the first node N1 and serves as the third end of the phase-A MCU switch circuit 332.

[0105] Specifically, the nineteenth voltage-dividing network includes a thirty-seventh voltage-dividing resistor R13 and a thirty-eighth voltage-dividing resistor R20. The first end of the thirty-seventh voltage-dividing resistor R13 serves as the first end of the nineteenth voltage-dividing network and is connected to the second node N2, serving as the second end of the A-phase MCU switch circuit 332 for inputting the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2. The second end of the thirty-seventh voltage-dividing resistor R13 is connected to the first end of the thirty-eighth voltage-dividing resistor R20, serving as the second end of the nineteenth voltage-dividing network. The second end of the thirty-eighth voltage-dividing resistor R20 serves as the third end of the nineteenth voltage-dividing network. The second end of the nineteenth voltage-dividing network is connected to the control electrode of the nineteenth switching transistor Q5. The third end of the nineteenth voltage-dividing network is connected to the first electrode of the nineteenth switching transistor Q5 and the ground terminal. The second electrode of the nineteenth switching transistor Q5 serves as the output end of the A-phase MCU switch circuit 332. The third resistor R5 is connected between the second electrode of the nineteenth switching transistor Q5 and the first node N1. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first-level signal, the nineteenth switching transistor Q5 is used to conduct according to the first-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the ground signal is transmitted to the first node N1, so that the potential of the output end of the A-phase MCU switch circuit 332 is zero, and the A-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switch unit 4. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a second-level signal, the nineteenth switching transistor Q5 is used to turn off according to the second-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the first power supply voltage U1 is output from the first node N1 through the third resistor R5. Thereby, the potential of the output end of the A-phase MCU switch circuit 332 is controlled to maintain the first power supply voltage U1, and the A-phase grid-side sub-relay of the grid-connected relay is adjusted to maintain the closed state through the corresponding coil switch unit 4.

[0106] Exemplarily, the nineteenth switching transistor Q5 may include a triode or a MOS transistor, etc. The nineteenth switching transistor Q5 may include a P-type or an N-type, and no limitation is made here.

[0107] Another alternative implementation manner, continue to refer to Figure 3Exemplarily, the B-phase MCU switching circuit 333 may include a twentieth switching transistor Q6, a twentieth voltage dividing network, and a fourth resistor R6; the first end of the twentieth voltage dividing network is connected to the second node N2, serving as the second end of the B-phase MCU switching circuit 333, the second end of the twentieth voltage dividing network is connected to the control electrode of the twentieth switching transistor Q6, the third end of the twentieth voltage dividing network is connected to the first electrode of the twentieth switching transistor Q6 and the ground terminal, serving as the first end of the B-phase MCU switching circuit 333, the second electrode of the twentieth switching transistor Q6 is connected to the first end of the fourth resistor R6, serving as the output end of the B-phase MCU switching circuit 333, and the second end of the fourth resistor R6 is connected to the first node N1, serving as the third end of the B-phase MCU switching circuit 333.

[0108] Specifically, the second voltage dividing network includes a thirty-ninth voltage dividing resistor R14 and a fortieth voltage dividing resistor R21. The first end of the thirty-ninth voltage dividing resistor R14 serves as the first end of the second voltage dividing network and is connected to the second node N2, serving as the second end of the B-phase MCU switch circuit 333, for inputting the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2. The second end of the thirty-ninth voltage dividing resistor R14 is connected to the first end of the fortieth voltage dividing resistor R21, serving as the second end of the second voltage dividing network. The second end of the fortieth voltage dividing resistor R21 serves as the third end of the second voltage dividing network. The second end of the second voltage dividing network is connected to the control electrode of the twentieth switching transistor Q6, and the third end of the second voltage dividing network is connected to the first electrode of the twentieth switching transistor Q6 and the ground terminal. The second electrode of the twentieth switching transistor Q6 serves as the output end of the B-phase MCU switch circuit 333, and the fourth resistor R6 is connected between the second electrode of the twentieth switching transistor Q6 and the first node N1. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first-level signal, the twentieth switching transistor Q6 is used to conduct according to the first-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the ground signal is transmitted to the first node N1, so that the potential of the output end of the B-phase MCU switch circuit 333 is zero, and the B-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switch unit 4. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a second-level signal, the twentieth switching transistor Q6 is used to turn off according to the second-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the first power supply voltage U1 is output from the first node N1 through the fourth resistor R6. Thus, the potential of the output end of the B-phase MCU switch circuit 333 is controlled to maintain the first power supply voltage U1, and the B-phase grid-side sub-relay of the grid-connected relay is adjusted to maintain a closed state through the corresponding coil switch unit 4.

[0109] Exemplarily, the twentieth switching transistor Q6 may include a triode or a MOS transistor, etc. The twentieth switching transistor Q6 may include a P-type or an N-type, and no limitation is made here.

[0110] Another optional implementation manner is continued to refer to Figure 3, Exemplarily, the C-phase MCU switching circuit 334 may include a twenty-first switching transistor Q6, a twenty-first voltage dividing network, and a fifth resistor R7; a first end of the twenty-first voltage dividing network is connected to the second node N2 and serves as the second end of the C-phase MCU switching circuit 334, a second end of the twenty-first voltage dividing network is connected to the control electrode of the twenty-first switching transistor Q6, a third end of the twenty-first voltage dividing network is connected to the first electrode of the twenty-first switching transistor Q6 and the ground terminal and serves as the first end of the C-phase MCU switching circuit 334, a second electrode of the twenty-first switching transistor Q6 is connected to the first end of the fifth resistor R7 and serves as the output end of the C-phase MCU switching circuit 334, and a second end of the fifth resistor R7 is connected to the first node N1 and serves as the third end of the C-phase MCU switching circuit 334.

[0111] Specifically, the twenty-first voltage dividing network includes a forty-first voltage dividing resistor R15 and a forty-second voltage dividing resistor R22. The first end of the forty-first voltage dividing resistor R15 serves as the first end of the twenty-first voltage dividing network and is connected to the second node N2, serving as the second end of the C-phase MCU switch circuit 334, for inputting the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2. The second end of the forty-first voltage dividing resistor R15 is connected to the first end of the forty-second voltage dividing resistor R22, serving as the second end of the twenty-first voltage dividing network. The second end of the forty-second voltage dividing resistor R22 serves as the third end of the twenty-first voltage dividing network. The second end of the twenty-first voltage dividing network is connected to the control electrode of the twenty-first switching transistor Q6, and the third end of the twenty-first voltage dividing network is connected to the first electrode of the twenty-first switching transistor Q6 and the ground terminal. The second electrode of the twenty-first switching transistor Q6 serves as the output end of the C-phase MCU switch circuit 334, and the fifth resistor R7 is connected between the second electrode of the twenty-first switching transistor Q6 and the first node N1. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a first-level signal, the twenty-first switching transistor Q6 is used to conduct according to the first-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the ground signal is transmitted to the first node N1, so that the potential of the output end of the C-phase MCU switch circuit 334 is zero, and the C-phase grid-side sub-relay of the grid-connected relay is adjusted to be disconnected through the coil switch unit 4. When the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2 is a second-level signal, the twenty-first switching transistor Q6 is used to turn off according to the second-level signal of the control signal MCU_GridRlyCtr_Hold output by the MCU potential regulating component 31 to the second node N2, and the first power supply voltage U1 is output from the first node N1 through the fifth resistor R7. Thus, the potential of the output end of the C-phase MCU switch circuit 334 is controlled to maintain the first power supply voltage U1, and the C-phase grid-side sub-relay of the grid-connected relay is adjusted to maintain the closed state through the corresponding coil switch unit 4.

[0112] Exemplarily, the twenty-first switching transistor Q6 may include a triode or a MOS transistor, etc. The twenty-first switching transistor Q6 may include a P-type or an N-type, and no limitation is made here.

[0113] Optionally, on the basis of the above embodiment, continue to refer to Figure 3 , the coil switch unit 4 may include: a negative coil switch unit 41 and a positive coil switch unit 42.

[0114] The first end of the negative - coil switch unit 41 is connected to the ground terminal, the second end of the negative - coil switch unit 41 is connected to the first end of the coil of the grid - connection relay, and the control end of the negative - coil switch unit 41 is connected to the first node N1; the negative - coil switch unit 41 is used to conduct the connection between the coil of the grid - connection relay and the ground terminal according to the first - level signal of the first node N1, and turn off according to the second - level signal of the first node N1.

[0115] The first end of the positive - coil switch unit 42 inputs the first power - supply voltage U1, the second end of the positive - coil switch unit 42 inputs the second power - supply voltage, such as +8V, and is connected to the second end of the coil of the grid - connection relay, the third end of the positive - coil switch unit 42 is connected to the ground terminal, the control end of the positive - coil switch unit 42 inputs the DSP hold signal Dsp_RlyHold, and the positive - coil switch unit 42 is used to adjust the voltage at the second end of the coil of the grid - connection relay to the first power - supply voltage U1, such as +12V when the DSP hold signal is the first - level signal; and adjust the voltage at the second end of the coil of the grid - connection relay to the second power - supply voltage when the DSP hold signal is the second - level signal; where the first power - supply voltage U1 is greater than the second power - supply voltage.

[0116] Specifically, the positive - coil switch unit 42 is used to control the positive - pole of each coil of the grid - connection relay to input the first power - supply voltage U1 or the second power - supply voltage. The negative - coil unit is used to control the negative - pole of each coil of the grid - connection relay to be conductively connected or disconnected from the ground terminal. When the positive - pole of the coil of the grid - connection relay inputs the first power - supply voltage U1 or the second power - supply voltage and its negative - pole is conductively connected to the ground terminal, the coil is powered on and closed. When the positive - pole of the coil of the grid - connection relay inputs the first power - supply voltage U1 or the second power - supply voltage and its negative - pole is disconnected from the ground terminal, the coil is powered off and disconnected.

[0117] Optionally, Figure 4 is a schematic structural diagram of a grid - connection relay provided by an embodiment of the present invention. On the basis of the above - mentioned embodiment, refer to Figure 4 , the grid - connection relay includes an N - phase inverter - side sub - relay K8, an A - phase inverter - side sub - relay K1, a B - phase inverter - side sub - relay K3, a C - phase inverter - side sub - relay K5, an N - phase grid - side sub - relay K9, an A - phase grid - side sub - relay K2, a B - phase grid - side sub - relay K4, and a C - phase grid - side sub - relay K6.

[0118] It should be noted that the inverter-side sub-relays of the grid-connected relay may include an N-phase inverter-side sub-relay K8, an A-phase inverter-side sub-relay K1, a B-phase inverter-side sub-relay K3, and a C-phase inverter-side sub-relay K5. The grid-side sub-relays of the grid-connected relay may include an N-phase grid-side sub-relay K9, an A-phase grid-side sub-relay K2, a B-phase grid-side sub-relay K4, and a C-phase grid-side sub-relay K6, without any limitation here.

[0119] The normally open contacts of the N-phase inverter-side sub-relay K8, the A-phase inverter-side sub-relay K1, the B-phase inverter-side sub-relay K3, and the C-phase inverter-side sub-relay K5 are respectively connected in series with the normally open contacts of the N-phase grid-side sub-relay K9, the A-phase grid-side sub-relay K2, the B-phase grid-side sub-relay K4, and the C-phase grid-side sub-relay K6 corresponding to the respective phase lines between the power inverter circuit and the grid.

[0120] The coils of the N-phase inverter-side sub-relay K8, the A-phase inverter-side sub-relay K1, the B-phase inverter-side sub-relay K3, and the C-phase inverter-side sub-relay K5 are connected in parallel between the third node AC Rly POWER and the fourth node; the first ends of the coils of the N-phase grid-side sub-relay K9, the A-phase grid-side sub-relay K2, the B-phase grid-side sub-relay K4, and the C-phase grid-side sub-relay K6 are all connected to the third node AC Rly POWER, and the third node AC Rly POWER is connected to the output end of the positive coil switch unit 42.

[0121] Continue to refer to Figure 3 , the negative coil switch unit 41, may include: an inverter-side switch component 411, an N-phase grid-side switch component 412, an A-phase grid-side switch component 413, a B-phase grid-side switch component 414, and a C-phase grid-side switch component 415.

[0122] The first end of the inverter-side switch component 411 is connected to the fourth node, the second end of the inverter-side switch component 411 is connected to the ground end, and the control end of the inverter-side switch component 411 is connected to the output end of the first DSP switch component 21 and the output end of the inverter-side relay control component 32. The inverter-side switch component 411 is used to control the N-phase inverter-side sub-relay K8, the A-phase inverter-side sub-relay K1, the B-phase inverter-side sub-relay K3, and the C-phase inverter-side sub-relay K5 to be powered on simultaneously when it is turned on according to the first coil control signal output by the first DSP switch component 21 or the second coil control signal output by the inverter-side relay control component 32, and to control the N-phase inverter-side sub-relay K8, the A-phase inverter-side sub-relay K1, the B-phase inverter-side sub-relay K3, and the C-phase inverter-side sub-relay K5 to be powered off simultaneously when it is turned off according to the first coil control signal output by the first DSP switch component 21 or the second coil control signal output by the inverter-side relay control component 32.

[0123] The first end of the N-phase grid-side switch component 412 is connected to the second end of the coil of the N-phase grid-side sub-relay K9. The second end of the N-phase grid-side switch component 412 is connected to the ground terminal. The control end of the N-phase grid-side switch component 412 is connected to the output end of the N-phase DSP switch circuit 221 of the second DSP switch component 22 and the output end of the N-phase MCU switch circuit 331 of the grid-side relay control component 33.

[0124] The first end of the A-phase grid-side switch component 413 is connected to the second end of the coil of the A-phase grid-side sub-relay K2. The second end of the A-phase grid-side switch component 413 is connected to the ground terminal. The control end of the A-phase grid-side switch component 413 is connected to the output end of the A-phase DSP switch circuit 222 of the second DSP switch component 22 and the output end of the A-phase MCU switch circuit 332 of the grid-side relay control component 33.

[0125] The first end of the B-phase grid-side switch component 414 is connected to the second end of the coil of the B-phase grid-side sub-relay K4. The second end of the B-phase grid-side switch component 414 is connected to the ground terminal. The control end of the B-phase grid-side switch component 414 is connected to the output end of the B-phase DSP switch circuit 223 of the second DSP switch component 22 and the output end of the B-phase MCU switch circuit 333 of the grid-side relay control component 33.

[0126] The first end of the C-phase grid-side switch component 415 is connected to the second end of the coil of the C-phase grid-side sub-relay K6. The second end of the C-phase grid-side switch component 415 is connected to the ground terminal. The control end of the C-phase grid-side switch component 415 is connected to the output end of the C-phase DSP switch circuit 224 of the second DSP switch component 22 and the output end of the C-phase MCU switch circuit 334 of the grid-side relay control component 33.

[0127] Specifically, such a setting enables the inverter-side relays on the inverter side to be disconnected or closed simultaneously, improving the control efficiency. On the other hand, the closing and disconnection requirements of the grid-side relays at different times can be better controlled separately, improving the control accuracy, preferably avoiding the arcing problem of the grid-side inverter, and improving the thermal stability and lifespan of the grid-connected relay.

[0128] Optionally, on the basis of the above embodiment, continue to refer to Figure 3 , the structures of the inverter-side switch component 411, the N-phase grid-side switch component 412, the A-phase grid-side switch component 413, the B-phase grid-side switch component 414, and the C-phase grid-side switch component 415 are the same. Such a setting facilitates the simplification of the design and cost savings.

[0129] The inverter-side switching component 411 may include a ninth switching transistor Q20 and a ninth voltage-dividing network; the first pole of the ninth switching transistor Q20 serves as the first terminal K8-G of the inverter-side switching component 411; the second pole of the ninth switching transistor Q20 is connected to the ground terminal and the first end of the ninth voltage-dividing network, serving as the second terminal of the inverter-side switching component 411; the control pole of the ninth switching transistor Q20 is connected to the second end of the ninth voltage-dividing network, and the third end of the ninth voltage-dividing network serves as the control terminal K8-Ctrl of the inverter-side switching component 411.

[0130] Specifically, the ninth voltage-dividing network includes a seventeenth voltage-dividing resistor R45 and an eighteenth voltage-dividing resistor R47. The first end of the seventeenth voltage-dividing resistor R45 serves as the first end of the ninth voltage-dividing network, the second end of the seventeenth voltage-dividing resistor R45 is connected to the first end of the eighteenth voltage-dividing resistor R47 and the control pole of the ninth switching transistor Q20, serving as the second end of the ninth voltage-dividing network, and the second end of the eighteenth voltage-dividing resistor R47 serves as the third end of the ninth voltage-dividing network.

[0131] Optionally, based on the above embodiments, continue to refer to Figure 3 , the positive coil switching unit 42 includes: a tenth switching transistor Q19, a tenth voltage-dividing network, an eleventh switching transistor Q21, and an eleventh voltage-dividing network.

[0132] The first pole of the tenth switching transistor Q19 is connected to the first end of the tenth voltage-dividing network, serving as the first end of the positive coil switching unit 42, and the first power supply voltage U1 is input. The second pole of the tenth switching transistor Q19 serves as the second end of the positive coil switching unit 42 to input the second power supply voltage and is connected to the third node AC Rly POWER; the control pole of the tenth switching transistor Q19 is connected to the second end of the tenth voltage-dividing network, the third end of the tenth voltage-dividing network is connected to the first pole of the eleventh switching transistor Q21, and the second pole of the eleventh switching transistor Q21 is connected to the first end of the eleventh voltage-dividing network and the ground terminal, serving as the third end of the positive coil switching unit 42; the second end of the eleventh voltage-dividing network is connected to the second pole of the eleventh switching transistor Q21, and the third end of the eleventh voltage-dividing network serves as the control terminal of the positive coil switching unit 42 to input the DSP hold signal Dsp_Rly Hold.

[0133] Specifically, the tenth voltage-dividing network includes a nineteenth voltage-dividing resistor R43 and a twentieth voltage-dividing resistor R44. The first end of the nineteenth voltage-dividing resistor R43 serves as the first end of the tenth voltage-dividing network, the second end of the nineteenth voltage-dividing resistor R43 is connected to the first end of the twentieth voltage-dividing resistor R44 and the control pole of the tenth switching transistor Q19, serving as the second end of the tenth voltage-dividing network, and the second end of the twentieth voltage-dividing resistor R44 serves as the third end of the tenth voltage-dividing network.

[0134] The eleventh voltage dividing network includes a twenty-first voltage dividing resistor R48 and a twenty-second voltage dividing resistor R46. The first end of the twenty-first voltage dividing resistor R48 serves as the first end of the eleventh voltage dividing network. The second end of the twenty-first voltage dividing resistor R48 is connected to the first end of the twenty-second voltage dividing resistor R46 and the control electrode of the eleventh switching transistor Q21, serving as the second end of the eleventh voltage dividing network. The second end of the twenty-second voltage dividing resistor R46 serves as the third end of the eleventh voltage dividing network.

[0135] An optionally implemented manner. On the basis of the above embodiments, continue to refer to Figure 3 , the N-phase grid-side switching component 412 may include a twelfth switching transistor Q18 and a twelfth voltage dividing network; the first pole of the twelfth switching transistor Q18 serves as the first end K9-G of the N-phase grid-side switching component 412; the second pole of the twelfth switching transistor Q18 is connected to the ground terminal and the first end of the twelfth voltage dividing network, serving as the second end of the N-phase grid-side switching component 412; the control electrode of the twelfth switching transistor Q18 is connected to the second end of the twelfth voltage dividing network, and the third end of the twelfth voltage dividing network serves as the control end K9-Ctrl of the N-phase grid-side switching component 412.

[0136] Among them, the twelfth voltage dividing network includes a twenty-third voltage dividing resistor R41 and a twenty-fourth voltage dividing resistor R42. The first end of the twenty-third voltage dividing resistor R41 serves as the first end of the twelfth voltage dividing network. The second end of the twenty-third voltage dividing resistor R41 is connected to the first end of the twenty-fourth voltage dividing resistor R42 and the control electrode of the twelfth switching transistor Q18, serving as the second end of the twelfth voltage dividing network. The second end of the twenty-fourth voltage dividing resistor R42 serves as the third end of the twelfth voltage dividing network.

[0137] Another optionally implemented manner Figure 5 is a schematic structural diagram of an energy storage inverter circuit provided by an embodiment of the present invention. Figure 6 is a schematic structural diagram of another energy storage inverter circuit provided by an embodiment of the present invention. On the basis of the above embodiments, continue to combine Figures 3 to 6 , the A-phase grid-side switching component 413 may include a thirteenth switching transistor Q11 and a thirteenth voltage dividing network; the first pole of the thirteenth switching transistor Q11 serves as the first end K2-G of the A-phase grid-side switching component 413; the second pole of the thirteenth switching transistor Q11 is connected to the ground terminal and the first end of the thirteenth voltage dividing network, serving as the second end of the A-phase grid-side switching component 413; the control electrode of the thirteenth switching transistor Q11 is connected to the second end of the thirteenth voltage dividing network, and the third end of the thirteenth voltage dividing network serves as the control end K2-Ctrl of the A-phase grid-side switching component 413.

[0138] Among them, the thirteenth voltage dividing network includes a twenty-fifth voltage dividing resistor R25 and a twenty-sixth voltage dividing resistor R27. The first end of the twenty-fifth voltage dividing resistor R25 serves as the first end of the thirteenth voltage dividing network. The second end of the twenty-fifth voltage dividing resistor R25 is connected to the first end of the twenty-sixth voltage dividing resistor R27 and the control electrode of the thirteenth switching transistor Q11, serving as the second end of the thirteenth voltage dividing network. The second end of the twenty-sixth voltage dividing resistor R27 serves as the third end of the thirteenth voltage dividing network.

[0139] Another optional implementation manner. On the basis of the above embodiments, continue to refer to Figure 3 , the B-phase grid-side switching component 414 may include a fourteenth switching transistor Q2 and a fourteenth voltage dividing network; the first pole of the fourteenth switching transistor Q2 serves as the first end K4-G of the B-phase grid-side switching component 414; the second pole of the fourteenth switching transistor Q2 is connected to the ground terminal and the first end of the fourteenth voltage dividing network, serving as the second end of the B-phase grid-side switching component 414; the control electrode of the fourteenth switching transistor Q2 is connected to the second end of the fourteenth voltage dividing network, and the third end of the fourteenth voltage dividing network serves as the control end K4-Ctrl of the B-phase grid-side switching component 414.

[0140] Among them, the fourteenth voltage dividing network includes a twenty-seventh voltage dividing resistor R8 and a twenty-eighth voltage dividing resistor R9. The first end of the twenty-seventh voltage dividing resistor R8 serves as the first end of the fourteenth voltage dividing network. The second end of the twenty-seventh voltage dividing resistor R8 is connected to the first end of the twenty-eighth voltage dividing resistor R9 and the control electrode of the fourteenth switching transistor Q2, serving as the second end of the fourteenth voltage dividing network. The second end of the twenty-eighth voltage dividing resistor R9 serves as the third end of the fourteenth voltage dividing network.

[0141] Another optional implementation manner. On the basis of the above embodiments, continue to refer to Figure 3 , the C-phase grid-side switching component 415 may include a fifteenth switching transistor Q1 and a fifteenth voltage dividing network; the first pole of the fifteenth switching transistor Q1 serves as the first end K6-G of the C-phase grid-side switching component 415; the second pole of the fifteenth switching transistor Q1 is connected to the ground terminal and the first end of the fifteenth voltage dividing network, serving as the second end of the C-phase grid-side switching component 415; the control electrode of the fifteenth switching transistor Q1 is connected to the second end of the fifteenth voltage dividing network, and the third end of the fifteenth voltage dividing network serves as the control end K6-Ctrl of the C-phase grid-side switching component 415.

[0142] Among them, the fifteenth voltage dividing network includes the twenty-ninth voltage dividing resistor R8 and the thirtieth voltage dividing resistor R9. The first end of the twenty-ninth voltage dividing resistor R8 serves as the first end of the fifteenth voltage dividing network. The second end of the twenty-ninth voltage dividing resistor R8 is connected to the first end of the thirtieth voltage dividing resistor R9 and the control electrode of the fifteenth switching transistor Q1, serving as the second end of the fifteenth voltage dividing network. The second end of the thirtieth voltage dividing resistor R9 serves as the third end of the fifteenth voltage dividing network.

[0143] Optionally, based on the above embodiments, continue to combine Figure 5 and Figure 6 , this embodiment provides a grid-connected relay control device 200, including the grid-connected relay control circuit 100 provided in any of the above embodiments. The grid-connected relay control device is connected to the control terminal of the grid-connected relay of the energy storage inverter circuit. The energy storage inverter circuit includes: a power source, a load, and a grid-connected relay. The power source is connected to the load and the first end of the grid-connected relay at the fifth node N5. The second end of the grid-connected relay is connected to the power grid at the sixth node N6. The grid-connected relay control device further includes a sampling control module 300. The sampling control module is connected to the sixth node N6 and is used to collect the first voltage of at least one phase of the three-phase voltage of the sixth node N6. The grid-connected relay control circuit 100 is connected to the sampling control module and the control terminal of the grid-connected relay. The grid-connected relay control circuit 100 is used to control the sub-switching unit of the grid-connected relay connected to the N phase of the sixth node N6 to close, and according to the difference between the first voltage and the preset threshold voltage, control the sub-switching unit of the grid-connected relay connected to the phase line where the amplitude of the first voltage is less than or equal to the preset threshold voltage to close.

[0144] Specifically, by first closing the grid-connected relay connected to the N phase of the sixth node N6, and then obtaining the first voltage of at least one phase of the three-phase voltage of the sixth node N6. According to the difference between the first voltage and the preset threshold voltage, control the target relay to close. With such a setting, the grid-connected relay connected to the phase line where the amplitude of the first voltage is equal to the preset threshold voltage can close when there is no current flowing through the contact, thereby avoiding arcing when the grid-connected relay closes, improving the thermal stability of the grid-connected relay, and thus prolonging the service life of the grid-connected relay.

[0145] Optionally, combine Figure 5 and Figure 6, the first voltage of at least one phase of the sixth node N6 includes at least one of the A-phase voltage, B-phase voltage, and C-phase voltage of the power grid; the grid-connected relay control circuit 100 is specifically configured to: according to the difference between the absolute value of the amplitude of the A-phase voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line whose absolute value of the amplitude of the A-phase voltage is less than or equal to the preset threshold voltage to be powered on and closed; according to the difference between the absolute value of the amplitude of the B-phase voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line whose absolute value of the amplitude of the B-phase voltage is less than or equal to the preset threshold voltage to be powered on and closed; according to the difference between the absolute value of the amplitude of the C-phase voltage and the preset threshold voltage, control the grid-connected relay connected to the phase line whose absolute value of the amplitude of the C-phase voltage is less than or equal to the preset threshold voltage to be powered on and closed.

[0146] Optionally, on the basis of the above embodiment, combined with Figure 5 and Figure 6 , the sampling control module may include a first sampling control unit 301, and the first sampling control unit 301 and the grid-connected relay are respectively connected to the fifth node N5 and the sixth node N6; the first sampling control unit 301 is connected to the grid-connected relay control circuit 100; the first sampling control unit 301 is configured to collect the second voltage of at least one phase of the fifth node N5, and collect the first voltage of at least one phase of the sixth node N6, and when the first voltage and the second voltage are not faulty, according to the difference between the first voltage and the preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line whose amplitude of the first voltage is less than or equal to the preset threshold voltage to be powered on and closed; wherein, the preset threshold voltage includes zero volts.

[0147] Specifically, it is possible to judge which phase line's phase voltage passes through the zero point first according to the A-phase voltage, B-phase voltage, and C-phase voltage of the power grid of the sixth node N6, and then close the grid-connected relay of the corresponding phase first. With this setting, the energy storage inverter circuit temporarily operates in a single-phase mode. Since the grid-connected relay is closed at the zero crossing point, there will be no voltage across the contacts of the relay, and no current will flow through the contacts. In this way, there will be no arcing between the contacts of the grid-connected relay, and no thermal failure phenomenon will occur. Similarly, then detect which phase line's phase voltage of the remaining two phases reaches the zero crossing point first, and close the grid-connected relay of the corresponding phase first, and so on, until all three-phase grid-connected relays are closed to achieve three-phase grid-connected operation.

[0148] Optionally, on the basis of the above embodiment, continue to combine Figure 5 and Figure 6, the first sampling control unit 301 may include: a DSP sampling controller. The DSP sampling controller is connected to the grid-connected relay at the fifth node N5 and the sixth node N6. The DSP sampling controller is configured to perform phase-locked loop operation after the voltage conversion module of the power supply operates in open loop for a first preset time. When the open-loop voltage and phase of the voltage conversion module are the same as those of the grid voltage and phase, it controls the sub-switch unit of the grid-connected relay connected to the N phase of the sixth node N6 to close, and when any one of the A-phase voltage, B-phase voltage, and C-phase voltage of the first voltage is equal to a preset threshold voltage, it controls the sub-switch unit of the grid-connected relay corresponding to the first voltage equal to the preset threshold voltage to close.

[0149] Specifically, when there is a fault in the grid-connected relay control device, the grid-connected relay needs to be disconnected to prevent the fault of the grid-connected relay control device from spreading to the grid. When a fault occurs in the energy storage inverter circuit, the grid-connected relay needs to be disconnected to prevent the fault of the energy storage inverter circuit from spreading to the grid. Only when it is ensured that both the energy storage inverter circuit and the grid-connected relay control device are free of faults can the grid-connected relay be controlled to close.

[0150] Optionally, on the basis of the above embodiments, continue to combine Figure 5 and Figure 6 , the sampling control module further includes a second sampling control unit 302. The second sampling control unit 302 is connected to the first sampling control unit 301. The second sampling control unit 302 is connected to the grid-connected relay at the fifth node N5 and the sixth node N6; the second sampling control unit 302 is connected to the grid-connected relay control circuit 100; the second sampling control unit 302 is configured to collect at least one phase of the second voltage at the fifth node N5 and collect at least one phase of the first voltage at the sixth node N6, and when the first voltage and the second voltage are free of faults, maintain the grid-connected relay powered on and closed according to the first voltage, and when the first voltage and / or the second voltage has a fault, control the grid-connected relay to power off.

[0151] Optionally, on the basis of the above embodiments, continue to refer to Figure 5 , the second sampling control unit 302 may include: an MCU sampling controller, which is communicatively connected to the DSP sampling controller and is respectively connected to the grid-connected relay at the fifth node N5 and the sixth node N6; the MCU sampling controller is respectively connected to the load and the voltage conversion module of the power supply; the MCU sampling controller is configured to take over the control right of the DSP sampling controller when the DSP sampling controller performs reset and upgrade or shutdown or grid connection and disconnection, and the energy storage inverter circuit is connected to the load, control the grid-connected relay to maintain the suction state, and when a fault occurs in the power supply, the load, and / or the grid-connected relay, control the grid-connected relay to disconnect.

[0152] Specifically, during the grid connection process, if a fault occurs, the DSP sampling control unit and the MCU sampling control unit will disconnect all grid connection relays through the grid connection relay control circuit 100. And control the inverter relay to disconnect for protective shutdown. Among them, Grid_Rely_Ctrl_K8, Grid_Rely_Ctrl_K9, Grid_Rely_Ctrl_K2, Grid_Rely_Ctrl_K4, Grid_Rely_Ctrl_K6, and Dsp_RlyHold are control signals output by the DSP sampling control unit. MCU_RlyHold and MCU_Rly12V are control signals output by the MCU sampling control unit.

[0153] When active shutdown is required, or there is a fault that requires shutdown, or grid connection / disconnection switching is needed, or the DSP control unit needs program upgrade and reset. If the power grid is normal at this time and the energy storage inverter circuit is connected to a load. The DSP sampling control unit first communicates with the MCU sampling control unit and transfers the control right to maintain the on state of the grid connection relay to the MCU sampling control unit. That is, Grid_Rely_Ctrl_K8 is set to 0, Grid_Rely_Ctrl_K9 is set to 0, Grid_Rely_Ctrl_K2 is set to 0, Grid_Rely_Ctrl_K4 is set to 0, Grid_Rely_Ctrl_K6 is set to 0, MCU_RlyHold is set to 0, Dsp_RlyHold is set to 0, and MCU_Rly12V is set to 1. The MCU sampling control unit is used to keep the grid connection relay in the closed state. At this time, the DSP sampling control unit can be reset and upgraded without causing the load to lose power, effectively ensuring the normal operation of the load and improving the user experience.

[0154] During the period when the MCU sampling control unit keeps the grid connection relay in the closed state, if a fault occurs or emergency off-grid operation is required, the MCU sampling control unit can also actively disconnect the grid connection relay, cut off the connection between the load and the power grid, and perform protection operations. When the MCU sampling control unit is used to keep the grid connection relay in the closed state, the DSP sampling control unit can also actively communicate with the MCU sampling control unit to take back the control right of the grid connection relay, that is, perform a series of operations. Exemplarily, the MCU sampling control unit and the DSP sampling control unit can communicate through SCI, but it is not limited to SCI communication.

[0155] Optionally, on the basis of the above embodiments, in combination with Figure 5 and Figure 6, the energy storage inverter circuit 400 provided in this embodiment includes: a power supply 21, a load 22, and a grid-connected relay 23. The power supply 21, the load 22, and the first end of the grid-connected relay 23 are connected to a fifth node N5. The second end of the grid-connected relay 23 is connected to the power grid at a sixth node N6. The control end of the grid-connected relay 23 is connected to the grid-connected relay control circuit 100 provided in any of the above embodiments, and / or connected to the grid-connected relay control device 200 provided in any of the above embodiments. The energy storage inverter circuit 400 provided in this embodiment has the beneficial effects of the grid-connected relay control device 200 provided in any of the above embodiments, which will not be elaborated here.

[0156] Note that the above is only a preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A grid-connected relay control circuit, characterized in that Including: A potential regulation unit, a first switch unit, a second switch unit, and a coil switch unit; The potential regulation unit is used to input a first power supply voltage. The potential regulation unit is respectively connected to the first switch unit and the second switch unit at a first node. The first switch unit is used to generate a first coil control signal according to a first type of control signal. The second switch unit is used to generate a second coil control signal according to a second type of control signal under a first preset working condition; The coil switch unit is connected between the ground terminal and the grid-connected relay. The control end of the coil switch unit is connected to the first node. The coil switch unit is used to control the grid-connected relay to close or open according to the first coil control signal; and under the first preset working condition, control the grid-connected relay to maintain the closed state or open according to the second coil control signal.

2. The grid-connected relay control circuit according to claim 1, wherein The first end of the potential regulation unit is used to input a first power supply voltage. The second end of the potential regulation unit is connected to the ground terminal. The control end of the potential regulation unit is used to input an MCU power supply signal. The output end of the potential regulation unit is used to output the first power supply voltage when the MCU power supply signal is a first level signal.

3. The grid-connected relay control circuit according to claim 1 or 2, characterized in that The potential regulation unit includes: A first switch transistor, a second switch transistor, a first voltage division network, and a second voltage division network; The first end of the first voltage division network is used to input an MCU power supply signal. The second end of the first voltage division network is connected to the control electrode of the first switch transistor. The third end of the first voltage division network is connected to the first electrode of the first switch transistor and the ground terminal. The second end of the first switch transistor is connected to the first end of the second voltage division network. The second end of the second voltage division network is connected to the control electrode of the second switch transistor. The third end of the second voltage division network is connected to the first electrode of the second switch transistor and inputs the first power supply voltage. The second electrode of the second switch transistor is connected to the first node; When the MCU power supply signal is a first level signal, the first switch transistor is used to conduct according to the first level signal of the MCU power supply signal. The second switch transistor is used to conduct according to the ground signal and control the potential of the first node to be the first power supply voltage; When the MCU power supply signal is a second level signal, the first switch transistor is used to turn off according to the second level signal of the MCU power supply signal, control the second switch transistor to turn off, and control the potential of the first node to be zero.

4. The grid-connected relay control circuit according to claim 1 or 2, wherein The first end of the first switch unit is connected to the ground terminal. The second end of the first switch unit is connected to the output end of the potential regulation unit and the control end of the coil switch unit at a first node. The control end of the first switch unit is used to input a first type of control signal. The first type of control signal includes a first type of control signal on the inverter side and a first type of control signal on the grid side; The first switching unit is configured to adjust the potential of the first node according to the first type of control signal on the inverter side, so as to adjust the conduction state of the inverter-side sub-relay of the grid-connected relay through the coil switching unit; and adjust the potential of the first node according to the first type of control signal on the grid side, so as to adjust the conduction state of the grid-side sub-relay of the grid-connected relay through the coil switching unit; the first coil control signal is a level signal output by the first switching unit.

5. The grid-connected relay control circuit according to claim 4, wherein, The first switching unit includes: a first DSP switching component and a second DSP switching component; The output end of the first DSP switching component is connected to the inverter-side sub-relay of the grid-connected relay through the coil switching unit. The first end of the first DSP switching component is connected to the first node, the second end of the first DSP switching component is connected to the ground terminal, and the control end of the first DSP switching component is used to input the inverter-side first type of control signal of the first type of control signal. The first DSP switching component is configured to adjust the potential of the first node according to the inverter-side first type of control signal, and adjust the conduction state of the inverter-side sub-relay of the grid-connected relay through the coil switching unit; The output end of the second DSP switching component is connected to the grid-side sub-relay of the grid-connected relay through the coil switching unit. The first end of the second DSP switching component is connected to the first node, the second end of the second DSP switching component is connected to the ground terminal, and the control end of the second DSP switching component is used to input the grid-side first type of control signal of the first type of control signal. The second DSP switching component is configured to adjust the potential of the first node according to the grid-side first type of control signal, and adjust the conduction state of the grid-side sub-relay of the grid-connected relay through the coil switching unit.

6. The grid-connected relay control circuit according to claim 5, wherein, The first DSP switching component includes: a third switching tube, a first resistor, and a third voltage-dividing network; The first end of the third voltage-dividing network is used to input the inverter-side first type of control signal. The second end of the third voltage-dividing network is connected to the control electrode of the third switching tube. The third end of the third voltage-dividing network is connected to the first pole of the third switching tube and the ground terminal. The second pole of the third switching tube is connected to the first node; the first resistor is connected between the second pole of the third switching tube and the first node, and the second pole of the third switching tube serves as the output end of the first DSP switching component; The third switching tube is configured to conduct when the inverter-side first type of control signal is a first level signal, adjust the potential of the output end of the first DSP switching component to zero, and adjust the inverter-side sub-relay of the grid-connected relay to be disconnected through the coil switching unit; the third switching tube is further configured to disconnect when the inverter-side first type of control signal is a second level signal, control the potential of the output end of the first DSP switching component to maintain the first power supply voltage, and adjust the inverter-side sub-relay of the grid-connected relay to be closed through the coil switching unit.

7. The grid-connected relay control circuit according to claim 5, wherein, The second DSP switch component includes: an N-phase DSP switch circuit, an A-phase DSP switch circuit, a B-phase DSP switch circuit, and a C-phase DSP switch circuit; the first type of grid-side control signals include: a first grid-side first type of control signal, a second grid-side first type of control signal, a third grid-side first type of control signal, and a fourth grid-side first type of control signal; The control terminal of the N-phase DSP switch circuit is used to input the first grid-side first type of control signal. The first terminal of the N-phase DSP switch circuit is connected to the ground terminal. The second terminal of the N-phase DSP switch circuit is connected to the first node. The output terminal of the N-phase DSP switch circuit is connected to the N-phase grid-side switch component of the coil switch unit. The N-phase DSP switch circuit is configured to output a first level signal when the first grid-side first type of control signal is a second level signal, and control the N-phase grid-side switch component of the coil switch unit to conduct, and control the N-phase grid-side sub-relay of the grid connection relay to close; when the first grid-side first type of control signal is a first level signal, output a second level signal, and control the N-phase grid-side switch component of the coil switch unit to disconnect, and control the N-phase grid-side sub-relay to disconnect; The A-phase DSP switch circuit is used to input the second grid-side first type of control signal. The first terminal of the A-phase DSP switch circuit is connected to the ground terminal. The second terminal of the A-phase DSP switch circuit is connected to the first node. The output terminal of the A-phase DSP switch circuit is connected to the A-phase grid-side switch component of the coil switch unit. The A-phase DSP switch circuit is configured to output a first level signal when the first grid-side first type of control signal is a second level signal, and control the A-phase grid-side switch component of the coil switch unit to conduct, and control the A-phase grid-side sub-relay of the grid connection relay to close; when the second grid-side first type of control signal is a first level signal, output a second level signal, and control the A-phase grid-side switch component of the coil switch unit to disconnect, and control the A-phase grid-side sub-relay to disconnect; The B-phase DSP switch circuit is used to input the third grid-side first type of control signal. The first terminal of the B-phase DSP switch circuit is connected to the ground terminal. The second terminal of the B-phase DSP switch circuit is connected to the first node. The output terminal of the B-phase DSP switch circuit is connected to the B-phase grid-side switch component of the coil switch unit. The B-phase DSP switch circuit is configured to output a first level signal when the third grid-side first type of control signal is a second level signal, and control the B-phase grid-side switch component of the coil switch unit to conduct, and control the B-phase grid-side sub-relay of the grid connection relay to close; when the third grid-side first type of control signal is a first level signal, output a second level signal, and control the B-phase grid-side switch component of the coil switch unit to disconnect, and control the B-phase grid-side sub-relay to disconnect; The C-phase DSP switch circuit is used to input the first type of control signal on the fourth grid side. The first end of the C-phase DSP switch circuit is connected to the ground terminal. The second end of the C-phase DSP switch circuit is connected to the first node. The output end of the C-phase DSP switch circuit is connected to the C-phase grid-side switch component of the coil switch unit. The C-phase DSP switch circuit is configured to output a first-level signal and control the conduction of the C-phase grid-side switch component of the coil switch unit when the first type of control signal on the fourth grid side is a second-level signal, and control the closing of the C-phase grid-side sub-relay of the grid-connected relay. When the first type of control signal on the fourth grid side is a first-level signal, it outputs a second-level signal, controls the disconnection of the C-phase grid-side switch component of the coil switch unit, and controls the disconnection of the C-phase grid-side sub-relay.

8. The grid-connected relay control circuit according to claim 7, wherein the N-phase DSP switch circuit includes a fourth switch tube, a fourth voltage-dividing network, and a second resistor. The first end of the fourth voltage-dividing network is used to input the first type of control signal on the first grid side. The second end of the fourth voltage-dividing network is connected to the control electrode of the fourth switch tube. The third end of the fourth voltage-dividing network is connected to the first electrode of the fourth switch tube and the ground terminal. The second electrode of the fourth switch tube serves as the output end of the N-phase DSP switch circuit. The second resistor is connected between the second electrode of the fourth switch tube and the first node. the A-phase DSP switch circuit includes a fifth switch tube, a fifth voltage-dividing network, and a third resistor. The first end of the fifth voltage-dividing network is used to input the first type of control signal on the second grid side. The second end of the fifth voltage-dividing network is connected to the control electrode of the fifth switch tube. The third end of the fifth voltage-dividing network is connected to the first electrode of the fifth switch tube and the ground terminal. The second electrode of the fifth switch tube serves as the output end of the A-phase DSP switch circuit. The third resistor is connected between the second electrode of the fifth switch tube and the first node. the B-phase DSP switch circuit includes a sixth switch tube, a sixth voltage-dividing network, and a fourth resistor. The first end of the sixth voltage-dividing network is used to input the first type of control signal on the third grid side. The second end of the sixth voltage-dividing network is connected to the control electrode of the sixth switch tube. The third end of the sixth voltage-dividing network is connected to the first electrode of the sixth switch tube and the ground terminal. The second electrode of the sixth switch tube serves as the output end of the B-phase DSP switch circuit. The fourth resistor is connected between the second electrode of the sixth switch tube and the first node. The C-phase DSP switching circuit includes a seventh switching transistor, a seventh voltage-dividing network, and a fifth resistor; the first end of the seventh voltage-dividing network is used to input a fourth grid-side first-type control signal, the second end of the seventh voltage-dividing network is connected to the control electrode of the seventh switching transistor, the third end of the seventh voltage-dividing network is connected to the first electrode of the seventh switching transistor and the ground terminal, the second electrode of the seventh switching transistor serves as the output terminal of the C-phase DSP switching circuit, and the fifth resistor is connected between the second electrode of the seventh switching transistor and the first node.

9. The grid-connected relay control circuit according to claim 5, wherein the control terminal of the second switching unit is used to input an MCU hold signal, the first end of the second switching unit is used to input a first power supply voltage, the second end of the second switching unit is connected to the ground terminal, the third end of the second switching unit is connected to the first node, and the second switching unit is configured to generate a first level signal when the MCU hold signal is a second level signal, and generate a second level signal when the MCU hold signal output by the MCU sampling controller is a first level signal; the second coil control signal is the level signal output by the second switching unit.

10. The grid-connected relay control circuit according to claim 8, characterized in that, The second switching unit includes: an MCU potential regulating component, an inverter-side relay control component, and a grid-side relay control component; the control terminal of the MCU potential regulating component inputs a second-type control signal, the first end of the MCU potential regulating component inputs a first power supply voltage, the second end of the MCU potential regulating component is connected to the ground terminal, and the output terminal of the MCU potential regulating component is connected to the control terminals of the inverter-side relay control component and the grid-side relay control component at a second node; the MCU potential regulating component is configured to generate a second level signal when the second-type control signal is a second level signal under a first preset working condition; and generate a first level signal when the second-type control signal is a first level signal; the first end of the inverter-side relay control component is connected to the ground terminal, the second end of the inverter-side relay control component is connected to the first node, and the output terminal of the inverter-side relay control component is connected to the inverter-side switching component of the coil switching unit; the inverter-side relay control component is configured to control the inverter-side relay to conduct through the inverter-side switching component according to the first level signal at the second node, and control the inverter-side relay to disconnect through the inverter-side switching component according to the second level signal at the second node; The first end of the grid-side relay control component is connected to the grounding end, the second end of the grid-side relay control component is connected to the first node, and the output end of the grid-side relay control component is connected to the grid-side switch component of the coil switch unit; the grid-side relay control component is configured to control the grid-side relay to conduct through the grid-side switch component according to the first level signal of the second node, and control the grid-side relay to disconnect through the grid-side switch component according to the second level signal of the second node.

11. The grid-connected relay control circuit according to claim 10, wherein the structure of the MCU potential regulation component is the same as that of the potential regulation unit; the structure of the inverter-side relay control component is the same as that of the first DSP switch component; the grid-side relay control component includes an N-phase MCU switch circuit, an A-phase MCU switch circuit, a B-phase MCU switch circuit, and a C-phase MCU switch circuit; the first end of the N-phase MCU switch circuit is connected to the grounding end, the second end of the N-phase MCU switch circuit is connected to the first node, and the output end of the N-phase MCU switch circuit is connected to the N-phase grid-side switch component of the coil switch unit; the N-phase MCU switch circuit is configured to control the N-phase grid-side relay of the grid-side relay to conduct through the N-phase grid-side switch component according to the first level signal of the second node, and control the N-phase grid-side relay of the grid-side relay to disconnect through the N-phase grid-side switch component according to the second level signal of the second node; the first end of the A-phase MCU switch circuit is connected to the grounding end, the second end of the A-phase MCU switch circuit is connected to the first node, and the output end of the A-phase MCU switch circuit is connected to the N-phase grid-side switch component of the coil switch unit; the A-phase MCU switch circuit is configured to control the A-phase grid-side relay of the grid-side relay to conduct through the A-phase grid-side switch component according to the first level signal of the second node, and control the A-phase grid-side relay of the grid-side relay to disconnect through the A-phase grid-side switch component according to the second level signal of the second node; the first end of the B-phase MCU switch circuit is connected to the grounding end, the second end of the B-phase MCU switch circuit is connected to the first node, and the output end of the B-phase MCU switch circuit is connected to the B-phase grid-side switch component of the coil switch unit; the B-phase MCU switch circuit is configured to control the B-phase grid-side relay of the grid-side relay to conduct through the B-phase grid-side switch component according to the first level signal of the second node, and control the B-phase grid-side relay of the grid-side relay to disconnect through the B-phase grid-side switch component according to the second level signal of the second node; The first end of the C-phase MCU switch circuit is connected to the ground terminal, the second end of the C-phase MCU switch circuit is connected to the first node, and the output end of the C-phase MCU switch circuit is connected to the C-phase grid-side switch component of the coil switch unit; the C-phase MCU switch circuit is configured to control the conduction of the C-phase grid-side relay of the grid-side relay through the C-phase grid-side switch component according to the first level signal of the second node, and control the disconnection of the C-phase grid-side relay through the C-phase grid-side switch component according to the second level signal of the second node; The structures of the N-phase MCU switch circuit, the A-phase MCU switch circuit, the B-phase MCU switch circuit, and the C-phase MCU switch circuit are the same; The N-phase MCU switch circuit includes an eighth switching tube, an eighth voltage-dividing network, and a second resistor; the first end of the eighth voltage-dividing network is connected to the second node, serving as the second end of the MCU switch circuit, the second end of the eighth voltage-dividing network is connected to the control electrode of the eighth switching tube, the third end of the eighth voltage-dividing network is connected to the first electrode of the eighth switching tube and the ground terminal, serving as the first end of the MCU switch circuit, the second electrode of the eighth switching tube is connected to the first end of the second resistor, serving as the output end of the MCU switch circuit, and the second end of the second resistor is connected to the first node, serving as the third end of the MCU switch circuit.

12. The grid-connected relay control circuit according to claim 5, characterized in that, The coil switch unit includes a negative coil switch unit and a positive coil switch unit; The first end of the negative coil switch unit is connected to the ground terminal, the second end of the negative coil switch unit is connected to the first end of the coil of the grid-connected relay, and the control end of the negative coil switch unit is connected to the first node; the negative coil switch unit is configured to conduct the connection between the coil of the grid-connected relay and the ground terminal according to the first level signal of the first node, and turn off according to the second level signal of the first node; The first end of the positive coil switch unit inputs a first power supply voltage, the second end of the positive coil switch unit 42 inputs a second power supply voltage and is connected to the second end of the coil of the grid-connected relay, the third end of the positive coil switch unit 42 is connected to the ground terminal, and the control end of the positive coil switch unit 42 inputs a DSP hold signal; the positive coil switch unit 42 is configured to adjust the voltage at the second end of the coil of the grid-connected relay to the first power supply voltage when the DSP hold signal is the first level signal; and adjust the voltage at the second end of the coil of the grid-connected relay to the second power supply voltage when the DSP hold signal is the second level signal; wherein, the first power supply voltage is greater than the second power supply voltage; The grid-connected relay includes an N-phase inverter-side sub-relay, an A-phase inverter-side sub-relay, a B-phase inverter-side sub-relay, a C-phase inverter-side sub-relay, an N-phase grid-side sub-relay, an A-phase grid-side sub-relay, a B-phase grid-side sub-relay, and a C-phase grid-side sub-relay; The normally open contacts of the N-phase inverter-side sub-relay, the A-phase inverter-side sub-relay, the B-phase inverter-side sub-relay, and the C-phase inverter-side sub-relay are respectively connected in series with the normally open contacts of the N-phase grid-side sub-relay, the A-phase grid-side sub-relay, the B-phase grid-side sub-relay, and the C-phase grid-side sub-relay of the corresponding phase lines between the power inverter circuit and the grid; The coils of the N-phase inverter-side sub-relay, the A-phase inverter-side sub-relay, the B-phase inverter-side sub-relay, and the C-phase inverter-side sub-relay are connected in parallel between the third node and the fourth node; the first ends of the coils of the N-phase grid-side sub-relay, the A-phase grid-side sub-relay, the B-phase grid-side sub-relay, and the C-phase grid-side sub-relay are all connected to the third node, and the third node is connected to the output end of the positive coil switch unit 42; The negative coil switch unit includes: an inverter-side switch component, an N-phase grid-side switch component, an A-phase grid-side switch component, a B-phase grid-side switch component, and a C-phase grid-side switch component; The first end of the inverter-side switch component is connected to the fourth node, the second end of the inverter-side switch component is connected to the ground end, and the control end of the inverter-side switch component is connected to the output end of the first DSP switch component and the output end of the inverter-side relay control component of the second switch unit. The inverter-side switch component is used to control the N-phase inverter-side sub-relay, the A-phase inverter-side sub-relay, the B-phase inverter-side sub-relay, and the C-phase inverter-side sub-relay to be powered on simultaneously when it is turned on according to the first coil control signal output by the first DSP switch component or the second coil control signal output by the inverter-side relay control component, and to control the N-phase inverter-side sub-relay, the A-phase inverter-side sub-relay, the B-phase inverter-side sub-relay, and the C-phase inverter-side sub-relay to be powered off simultaneously when it is turned off according to the first coil control signal output by the first DSP switch component or the second coil control signal output by the inverter-side relay control component; The first end of the N-phase grid-side switch component is connected to the second end of the coil of the N-phase grid-side sub-relay, the second end of the N-phase grid-side switch component is connected to the ground end, and the control end of the N-phase grid-side switch component is connected to the output end of the N-phase DSP switch circuit of the second DSP switch component and the output end of the N-phase MCU switch circuit of the grid-side relay control component of the second switch unit; The first end of the A-phase grid-side switch component is connected to the second end of the coil of the A-phase grid-side sub-relay, the second end of the A-phase grid-side switch component is connected to the ground end, and the control end of the A-phase grid-side switch component is connected to the output end of the A-phase DSP switch circuit of the second DSP switch component and the output end of the A-phase MCU switch circuit of the grid-side relay control component; The first end of the B-phase grid-side switch component is connected to the second end of the coil of the B-phase grid-side sub-relay. The second end of the B-phase grid-side switch component is connected to the ground terminal. The control end of the B-phase grid-side switch component is connected to the output end of the B-phase DSP switch circuit of the second DSP switch component and the output end of the B-phase MCU switch circuit of the grid-side relay control component. The first end of the C-phase grid-side switch component is connected to the second end of the coil of the C-phase grid-side sub-relay. The second end of the C-phase grid-side switch component is connected to the ground terminal. The control end of the C-phase grid-side switch component is connected to the output end of the C-phase DSP switch circuit of the second DSP switch component and the output end of the C-phase MCU switch circuit of the grid-side relay control component.

13. The grid-connected relay control circuit according to claim 12, wherein the inverter-side switch component, the N-phase grid-side switch component, the A-phase grid-side switch component, the B-phase grid-side switch component, and the C-phase grid-side switch component have the same structure; the inverter-side switch component includes a ninth switch tube and a ninth voltage-dividing network. The first pole of the ninth switch tube serves as the first end of the inverter-side switch component. The second pole of the ninth switch tube is connected to the ground terminal and the first end of the ninth voltage-dividing network, serving as the second end of the inverter-side switch component. The control pole of the ninth switch tube is connected to the second end of the ninth voltage-dividing network, and the third end of the ninth voltage-dividing network serves as the control end of the inverter-side switch component; The positive coil switch unit includes: a tenth switch tube, a tenth voltage-dividing network, an eleventh switch tube, and an eleventh voltage-dividing network; The first pole of the tenth switch tube is connected to the first end of the tenth voltage-dividing network, serving as the first end of the positive coil switch unit and inputting a first power supply voltage. The second pole of the tenth switch tube serves as the second end of the positive coil switch unit and inputs a second power supply voltage, and is connected to the third node. The control pole of the tenth switch tube is connected to the second end of the tenth voltage-dividing network. The third end of the tenth voltage-dividing network is connected to the first pole of the eleventh switch tube. The second pole of the eleventh switch tube is connected to the first end of the eleventh voltage-dividing network and the ground terminal, serving as the third end of the positive coil switch unit. The second end of the eleventh voltage-dividing network is connected to the second pole of the eleventh switch tube, and the third end of the eleventh voltage-dividing network serves as the control end of the positive coil switch unit and inputs a DSP hold signal.

14. A grid-connected relay control device, characterized in that It includes the grid-connected relay control circuit according to any one of claims 1 to 13. The grid-connected relay control device is connected to the control end of the grid-connected relay of the energy storage inverter circuit. The energy storage inverter circuit includes: a power supply, a load, and a grid-connected relay. The power supply is connected to the load and the first end of the grid-connected relay at a fifth node. The second end of the grid-connected relay is connected to the power grid at a sixth node; The grid-connected relay control device further includes a sampling control module, which is connected to the sixth node and is used to collect a first voltage of at least one phase of the three-phase voltage of the sixth node; The grid-connected relay control circuit is connected to the sampling control module and the control end of the grid-connected relay. The grid-connected relay control circuit is used to control the sub-switch unit of the grid-connected relay connected to the N phase of the sixth node to close, and according to the difference between the first voltage and a preset threshold voltage, control the sub-switch unit of the grid-connected relay connected to the phase line where the amplitude of the first voltage is less than or equal to the preset threshold voltage to close.

15. A energy storage inverter circuit, characterized in that, Comprising: A power supply, a load and a grid-connected relay. The power supply is connected to the load and the first end of the grid-connected relay at a fifth node. The second end of the grid-connected relay is connected to the power grid at a sixth node. The control end of the grid-connected relay is connected to the grid-connected relay control circuit according to any one of claims 1 to 13, and / or, connected to the grid-connected relay control device according to claim 14.

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