Inverter grid-connected starting method and related equipment

Abstract

The invention relates to an inverter grid-connected starting method and related equipment. Wherein the bus input end of the inverter is connected with the direct current power supply, the bus input midpoint of the inverter is connected with the zero line input of the commercial power input through the zero line switch, and the three-phase output end of the inverter is connected with the three-phase input of the commercial power input through the three-phase switch; the method comprises the following steps: when a three-phase switch and a zero line switch are switched off, respectively obtaining first three-phase input parameters corresponding to commercial power input; when the first three-phase input parameter is in a normal range, a zero line switch is closed, so that the bus input midpoint of the inverter is connected with the zero line input of the commercial power input; acquiring a second three-phase input parameter corresponding to the commercial power input and adjusting the working state of the inverter; and when the output parameter corresponding to the three-phase output end of the inverter meets a preset condition, closing the three-phase switch to enable the inverter to complete grid connection. According to the invention, the impact current at the moment of starting grid connection of the inverter can be effectively reduced, and the reliability of a working circuit corresponding to the inverter is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter grid-connected technology, and more specifically, to an inverter grid-connected starting method and related equipment. Background Art

[0002] The three-phase hybrid inverter distributes the energy of batteries, photovoltaic panels and power grids according to different situations. The functions involving the power grid need to be connected to the grid. The grid connection process requires controlling the relays and inverters to contact the grid at a specific time to ensure that the city power can safely and effectively receive and release energy, and avoid generating large impact currents that burn out the circuit. Among the current common measures, it is necessary to consider the size of the inverter bus voltage in advance, and output the inverter voltage at a specific grid voltage zero point; or use an algorithm to phase-lock the grid voltage and control the voltage vector to output the inverter voltage, and only judge the line voltage, without considering the situation of the neutral line. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an inverter grid-connected starting method and related equipment in view of the above-mentioned technical defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing an inverter grid-connected starting method, wherein the bus input end of the inverter is connected to a DC power supply, the bus input midpoint of the inverter is connected to the neutral input of the mains input through a neutral switch, and the three-phase output ends of the inverter are respectively connected to the three-phase inputs of the mains input through three-phase switches; the method comprises:

[0005] S1. When the three-phase switch and the neutral line switch are both disconnected, respectively obtain first three-phase input parameters corresponding to the mains input;

[0006] S2. When the first three-phase input parameter is within a normal range, close the neutral line switch to connect the midpoint of the busbar input of the inverter to the neutral line input of the mains input;

[0007] S3, obtaining a second three-phase input parameter corresponding to the mains input, and adjusting the working state of the inverter according to the second three-phase input parameter;

[0008] S4. When the output parameters corresponding to the three-phase output terminals of the inverter meet preset conditions, the three-phase switch is closed to enable the inverter to be connected to the grid.

[0009] Preferably, in the inverter grid-connected startup method described in the embodiment of the present invention, the method further includes:

[0010] When the first three-phase input parameter is not within a normal range, a preset alarm message is generated.

[0011] Preferably, in the inverter grid-connected startup method described in the embodiment of the present invention, in the step S2, when the first three-phase input parameter is within a normal range, it includes:

[0012] The rated voltage corresponding to the AC power input is obtained, and when a voltage parameter among the first three-phase input parameters is within a preset range of the rated voltage, it is determined that the first three-phase input parameters are within a normal range.

[0013] Preferably, in the inverter grid-connected startup method described in the embodiment of the present invention, the preset range includes 80% to 120%.

[0014] Preferably, in the inverter grid-connected startup method described in the embodiment of the present invention, in the step S3, adjusting the working state of the inverter according to the second three-phase input parameter includes:

[0015] The working state of the inverter is adjusted according to the phase and frequency of the second three-phase input parameter, so that the output parameter of the inverter is synchronized with the second three-phase input parameter.

[0016] Preferably, in the inverter grid-connected startup method described in the embodiment of the present invention, in the step S3, the step of adjusting the working state of the inverter according to the second three-phase input parameter further includes:

[0017] The inverter is slowly started by outputting a PWM duty cycle through open-loop control, so that the absolute difference between the voltage amplitude of the output parameter of the inverter and the voltage parameter of the second three-phase input parameter is smaller than a preset value.

[0018] The present invention also constructs an inverter grid-connected startup control system, wherein the bus input end of the inverter is connected to a DC power supply, the midpoint of the bus input of the inverter is connected to the neutral input of the mains input via a neutral switch, and the three-phase output ends of the inverter are respectively connected to the three-phase inputs of the mains input via three-phase switches; the control system comprises:

[0019] A first sampling unit, used for respectively acquiring first three-phase input parameters corresponding to the mains input when the three-phase switch and the neutral line switch are both disconnected;

[0020] A first execution unit is used to close the neutral line switch when the first three-phase input parameter is within a normal range, so that the midpoint of the bus input of the inverter is connected to the neutral line input of the mains input;

[0021] A second sampling unit, used for acquiring a second three-phase input parameter corresponding to the mains input, and adjusting the working state of the inverter according to the second three-phase input parameter;

[0022] The second execution unit is used to close the three-phase switch when the output parameters corresponding to the three-phase output terminals of the inverter meet preset conditions, so that the inverter can be connected to the grid.

[0023] Preferably, in an inverter grid-connected startup control system of the present invention, it also includes:

[0024] The alarm information generating unit is used to generate preset alarm information when the first three-phase input parameter is not within a normal range.

[0025] The present invention also constructs an electronic device, comprising a memory and a processor;

[0026] The memory is used to store computer programs;

[0027] The processor is configured to execute the computer program to implement the method described above.

[0028] The present invention also constructs a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0029] The inverter grid-connected starting method and related equipment of the present invention have the following beneficial effects: the impact current at the moment of inverter starting and grid-connected can be effectively reduced, and the reliability of the corresponding working circuit of the inverter can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0031] Figure 1 It is a structural schematic diagram of the inverter networking in the present invention;

[0032] Figure 2 is a program flow chart of an embodiment of an inverter grid-connected startup method of the present invention;

[0033] Figure 3 is a program flow chart of another embodiment of the inverter grid-connected startup method of the present invention;

[0034] Figure 4 It is a logic block diagram of an embodiment of an inverter grid-connected startup control system of the present invention. DETAILED DESCRIPTION

[0035] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0036] like Figure 1As shown, in the first embodiment of the inverter grid-connected startup method of the present invention, the bus input end of the inverter 200 is connected to a DC power supply, the bus input midpoint of the inverter 200 is connected to the neutral input of the mains input 300 via a neutral switch 420, and the three-phase output ends of the inverter 200 are connected to the three-phase input of the mains input 300 via a three-phase switch 410. The bus input end of the inverter 200 can be connected to a photovoltaic charging circuit or a battery power supply circuit, and the three-phase output end of the inverter 200 is connected to the three-phase input of the mains input 300 via a three-phase switch 410. During operation, the load can be powered by the three-phase output end of the inverter 200, or by the three-phase input of the mains input 300. It can also be connected to the grid when necessary, and the load can be powered by the three-phase output end of the inverter 200 and the three-phase input of the mains input 300 at the same time. When only the three-phase input of the mains input 300 supplies power to the load or only the three-phase input of the inverter 200 supplies power to the load, the three-phase output of the inverter 200 and the three-phase input of the mains input 300 can be connected to the grid so that the load is powered at the same time. Wherein, the DC power supply may include a photovoltaic power generation circuit 110, and the photovoltaic power generation circuit 110 provides a DC input to the inverter 200, and the inverter 200 converts the DC input to obtain a three-phase inverter output to power the load. In another embodiment, when the DC power supply includes an energy storage battery 120, the three-phase input of the mains input 300 can be connected to the grid so that the energy storage battery 120 is powered. Wherein, the three-phase switch 410 and the neutral line switch 420 include and are not limited to being formed by a relay circuit. In a specific embodiment, the R line relay, the S line relay and the T line relay correspond to one phase of the three-phase switch 410 respectively, and the N line relay corresponds to the neutral line switch 420. During the inverter grid connection process, it is necessary to consider that before the three-phase switch 410 is closed, the voltage difference between the two sides of each phase in the three-phase switch 410 must be small enough to avoid the impact current generated after the three-phase switch 410 is closed, causing faults or even burning out the circuit.

[0037] like Figure 2 As shown, the specific grid-connected startup method may include the following steps: S1. When the three-phase switch 410 and the neutral switch 420 are both disconnected, respectively obtain the first three-phase input parameters corresponding to the mains input 300. S2. When the first three-phase input parameter is within the normal range, close the neutral switch 420 so that the bus input midpoint of the inverter 200 is connected to the neutral input of the mains input 300. S3. Obtain the second three-phase input parameter corresponding to the mains input 300, and adjust the working state of the inverter 200 according to the second three-phase input parameter. S4. When the output parameters corresponding to the three-phase output terminal of the inverter 200 meet the preset conditions, close the three-phase switch 410 so that the inverter 200 completes the grid connection.

[0038] Based on step S1, before the grid connection, the mains input 300 and the inverter 200 are completely disconnected. That is, by setting the three-phase switch 410 to the off state, the three-phase input of the mains input 300 and the three-phase output of the inverter 200 are in a disconnected state. It can be understood that the three-phase switch 410 includes but is not limited to three groups of phase switches, which correspond to the three phases of the mains input 300 respectively, and are used to control one phase input of the mains input 300 and one phase output of the inverter 200 to be turned on or off respectively. By setting the neutral line switch 420 to the off state, the bus input midpoint of the inverter 200 and the neutral line input of the mains input 300 are turned off. When the inverter 200 needs to be connected to the grid, the voltage condition of the mains input 300 is first confirmed, that is, the current three-phase input parameter of the mains input 300, that is, the first three-phase input parameter, is obtained. In one embodiment, the first three-phase input parameter includes a three-phase mains input 300 voltage of the mains input 300 .

[0039] Based on step S2, after obtaining the first three-phase input parameter, the obtained first three-phase input parameter is judged to confirm whether the current third input parameter is within the normal range. Among them, the normal range is a known range set in advance. When it can be determined that the first three-phase input parameter is within the normal range, the zero line switch 420 is triggered to close. At this time, the bus input midpoint of the inverter 200 is connected to the zero line input of the mains input 300. Finally, the potential of the middle point of the inverter 200 is consistent with the zero line of the power grid, ensuring that the output voltage reference of the inverter 200 is consistent with the voltage reference of the power grid.

[0040] Based on step S3 and step S4, on the basis of the above, the three-wire input parameter corresponding to the mains input 300, i.e., the second three-phase input parameter, is continued to be obtained, and the working state of the inverter 200 is adjusted according to the second three-phase input parameter, so that the input parameter of the mains input 300 is consistent with the output parameter of the inverter 200. It can be understood that, with the three-phase input parameter of the mains input 300 as the target value, the working state of the inverter 200 is adjusted so that the output parameter of each phase output terminal of the inverter 200 is consistent with the phase input parameter of the mains input 300 to be connected. It should be pointed out here that the consistency of the output parameter of the inverter 200 and the input parameter of the mains input 300 is not limited to being completely consistent. When the difference is within the allowed range set in advance, the above two can also be determined to be consistent. That is, when the output parameter of the three-phase output terminal of the inverter 200 meets the preset condition, it can be determined that the above two are consistent. At this time, the three-phase switch 410 can be closed, so that the inverter 200 forms a connection relationship with the mains input 300, and finally the grid connection of the inverter 200 is realized.

[0041] like Figure 3As shown, in one embodiment of the inverter grid-connected startup method of the present invention, the step is further included: S21, when the first three-phase input parameter is not within the normal range, a preset alarm message is generated. That is, before the inverter is grid-connected, if the input parameters of the power grid do not meet the grid-connected conditions, it can be determined that the inverter cannot be grid-connected at this time, and correspondingly, a corresponding alarm message can be generated to prompt the grid-connected operation, such as prompting that the grid-connected action cannot be performed, to avoid abnormal grid connection causing abnormality of the entire working circuit.

[0042] In one embodiment, in the step S2, when the first three-phase input parameter is within the normal range, it includes: obtaining the rated voltage corresponding to the mains input 300, and when the voltage parameter in the first three-phase input parameter is within the preset range of the rated voltage, it is determined that the first three-phase input parameter is within the normal range. Specifically, the first three-phase input parameter may include the voltage parameter of the mains input 300, that is, when it is determined that the voltage parameter of the mains input 300 is within the normal voltage range of the mains input 300, it can be determined that the first three-phase input parameter of the mains input 300 is within the normal range. Among them, the normal voltage range of the mains input 300 can be determined according to the rated voltage of the mains input 300. That is, the preset range of the rated voltage is set as the normal voltage range of the mains input 300. In one embodiment, it includes but is not limited to setting the normal voltage range of the mains input 300 to 80% to 120% of the rated voltage. In a specific embodiment, when the rated voltage of the mains input 300 is 220V, the normal voltage range of the mains input 300 can be set to 180V to 250V. That is, if the voltage parameter of the mains input 300 is between 180V and 250V at this time, it can be determined that the first three-phase input parameter of the mains input 300 is within the normal range. When the voltage parameter of the mains input 300 is not between 180V and 250V, it can be determined that the first three-phase input parameter of the mains input 300 is not within the normal range, and a corresponding voltage abnormality alarm can be generated at this time. In a specific embodiment, different alarm information can also be generated according to the voltage being too high or too low to indicate the specific abnormal cause.

[0043] In one embodiment, in the step S3, adjusting the working state of the inverter 200 according to the second three-phase input parameter includes: adjusting the working state of the inverter 200 according to the phase and frequency of the second three-phase input parameter, so that the output parameters of the inverter 200 are synchronized with the second three-phase input parameter. Specifically, adjusting the working state of the inverter 200 so that the output parameters of the inverter 200 are synchronized with the input parameters of the mains input 300 includes making the phase and frequency in the output parameters of the inverter 200 consistent with the phase and frequency of the mains input 300. It should be pointed out here that the consistency of the phase and frequency in the output parameters of the inverter 200 with the phase and frequency of the mains input 300 is not limited to being completely consistent, and when the difference is within a pre-set allowable range, it can also be determined that the above two are consistent.

[0044] In one embodiment, in the step S3, the adjusting the working state of the inverter 200 according to the second three-phase input parameter further includes: slowly starting the inverter 200 by outputting a PWM duty cycle through open-loop control, so that the absolute difference between the voltage amplitude of the output parameter of the inverter 200 and the voltage parameter of the second three-phase input parameter is less than a preset value. Specifically, the PWM duty cycle of the inverter 200 can also be open-loop controlled so that the difference between the three-phase inverter voltage of the inverter 200 and the grid voltage of the corresponding phase is less than a preset value. The preset value can be set according to different requirements.

[0045] Through the above process, when the three phases of the power grid are unbalanced, the impact current generated when the three-phase switch 410 is closed can be reduced, and the whole process does not need to judge in advance whether the bus voltage of the inverter 200 is greater than the peak voltage of the power grid, because in some scenarios, if the bus voltage of the inverter 200 is too small, the inverter voltage of the open-loop output of the inverter 200 cannot reach the condition of closing the three-phase switch 410, that is, when the bus voltage of the inverter 200 is too small, the inverter grid connection cannot be achieved. Moreover, in the method of the present invention, there is no need to increase the hardware cost, and it is realized through the software process. The whole processing process is fast and simple, and can be applied to a variety of different scenarios.

[0046] In addition, in an inverter grid-connected startup control system disclosed in an embodiment of the present invention, Figure 1As shown, the bus input end of the inverter 200 is connected to a DC power supply, the midpoint of the bus input of the inverter 200 is connected to the neutral input of the mains input 300 via a neutral switch 420, and the three-phase output ends of the inverter 200 are connected to the three-phase input of the mains input 300 via a three-phase switch 410. The bus input end of the inverter 200 can be connected to a photovoltaic charging circuit or a battery power supply circuit, and the three-phase output end of the inverter 200 is connected to the three-phase input of the mains input 300 via a three-phase switch 410. During operation, the load can be powered by the three-phase output end of the inverter 200, or by the three-phase input of the mains input 300. It can also be connected to the grid when necessary, and the load can be powered by the three-phase output end of the inverter 200 and the three-phase input of the mains input 300 at the same time. When only the three-phase input of the mains input 300 supplies power to the load or only the three-phase input of the inverter 200 supplies power to the load, the three-phase output of the inverter 200 and the three-phase input of the mains input 300 can be connected to the grid so that the load is powered at the same time. Wherein, the DC power supply may include a photovoltaic power generation circuit 110, and the photovoltaic power generation circuit 110 provides a DC input to the inverter 200, and the inverter 200 converts the DC input to obtain a three-phase inverter output to power the load. In another embodiment, when the DC power supply includes an energy storage battery 120, the three-phase input of the mains input 300 can be connected to the grid so that the energy storage battery 120 is powered. Wherein, the three-phase switch 410 and the neutral line switch 420 include and are not limited to being formed by a relay circuit. In a specific embodiment, the R line relay, the S line relay and the T line relay correspond to one phase of the three-phase switch 410 respectively, and the N line relay corresponds to the neutral line switch 420.

[0047] like Figure 4 As shown, the control system includes: a first sampling unit 401, which is used to obtain the first three-phase input parameters corresponding to the mains input 300 when the three-phase switch 410 and the neutral switch 420 are both disconnected. A first execution unit 402 is used to close the neutral switch 420 when the first three-phase input parameter is within the normal range, so that the bus input midpoint of the inverter 200 is connected to the neutral input of the mains input 300. A second sampling unit 403 is used to obtain the second three-phase input parameters corresponding to the mains input 300, and adjust the working state of the inverter 200 according to the second three-phase input parameters. A second execution unit 404 is used to close the three-phase switch 410 when the output parameters corresponding to the three-phase output end of the inverter 200 meet the preset conditions, so that the inverter 200 completes the grid connection. Specifically, the specific coordination operation process between the various units of the inverter grid connection start control system here can be specifically referred to the above-mentioned inverter grid connection start method, that is, the specific process of implementing the above-mentioned method through the coordination of various units, which will not be repeated here.

[0048] In one embodiment, the control system further includes: an alarm information generation unit, which is used to generate a preset alarm information when the first three-phase input parameter is not within a normal range. That is, the corresponding alarm information can be generated by the alarm information generation unit. For example, before the inverter is connected to the grid, if the input parameters of the power grid do not meet the grid connection conditions, it can be determined that the inverter cannot be connected to the grid at this time, and accordingly, the alarm information generation unit can generate corresponding alarm information to prompt the grid connection operation, such as prompting that the grid connection action cannot be performed, to avoid abnormal grid connection causing abnormality of the entire working circuit.

[0049] In one embodiment, the second sampling unit includes an inverter adjustment unit; the inverter adjustment unit is used to adjust the working state of the inverter according to the phase and frequency of the second three-phase input parameter, so that the output parameter of the inverter is synchronized with the second three-phase input parameter. Specifically, the inverter can be controlled by the inverter adjustment unit to adjust the working state, and the specific adjustment process can refer to the process described in the above method.

[0050] In addition, in an electronic device disclosed in an embodiment of the present invention, a memory and a processor are included; the memory is used to store a computer program; the processor is used to execute the computer program to implement the method described above. Specifically, according to an embodiment of the present invention, the process described with reference to the flowchart above can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed by an electronic device and when executed, it performs the above functions defined in the method of the embodiment of the present invention.

[0051] In addition, a computer storage medium of the present invention stores a computer program thereon, and when the computer program is executed by a processor, any of the above methods is implemented. Specifically, it should be noted that the above-mentioned computer-readable medium of the present invention may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, device or device. In the present invention, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer readable signal media may also be any computer readable medium other than computer readable storage media, which may send, propagate, or transmit programs for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0052] The computer-readable medium may be included in the electronic device, or may exist independently without being incorporated into the electronic device.

[0053] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A method for starting an inverter in grid connection, characterized in that: in, The bus input end of the inverter is connected to a DC power supply, the bus input midpoint of the inverter is connected to the neutral input of the mains input via a neutral switch, and the three-phase output ends of the inverter are connected to the three-phase inputs of the mains input via three-phase switches; the method comprises the following steps: S1. When the three-phase switch and the neutral line switch are both disconnected, respectively obtain first three-phase input parameters corresponding to the mains input; S2. When the first three-phase input parameter is within a normal range, close the neutral line switch to connect the midpoint of the busbar input of the inverter to the neutral line input of the mains input; S3, obtaining a second three-phase input parameter corresponding to the mains input, and adjusting the working state of the inverter according to the second three-phase input parameter; S4. When the output parameters corresponding to the three-phase output terminals of the inverter meet preset conditions, the three-phase switch is closed to enable the inverter to be connected to the grid.

2. The inverter grid-connected startup method according to claim 1, characterized in that: The method further comprises: When the first three-phase input parameter is not within a normal range, a preset alarm message is generated.

3. The inverter grid-connected startup method according to claim 1, characterized in that: In the step S2, when the first three-phase input parameter is within a normal range, the step includes: The rated voltage corresponding to the AC power input is obtained, and when a voltage parameter among the first three-phase input parameters is within a preset range of the rated voltage, it is determined that the first three-phase input parameters are within a normal range.

4. The inverter grid-connected startup method according to claim 3, characterized in that: The preset range includes 80% to 120%.

5. The inverter grid-connected startup method according to claim 1, characterized in that: In the step S3, adjusting the working state of the inverter according to the second three-phase input parameter includes: The working state of the inverter is adjusted according to the phase and frequency of the second three-phase input parameter, so that the output parameter of the inverter is synchronized with the second three-phase input parameter.

6. The inverter grid-connected startup method according to claim 5, characterized in that: In the step S3, adjusting the working state of the inverter according to the second three-phase input parameter further includes: The inverter is slowly started by outputting a PWM duty cycle through open-loop control, so that the absolute difference between the voltage amplitude of the output parameter of the inverter and the voltage parameter of the second three-phase input parameter is smaller than a preset value.

7. An inverter grid-connected startup control system, characterized in that: The bus input end of the inverter is connected to a DC power supply, the midpoint of the bus input of the inverter is connected to the neutral input of the mains input via a neutral switch, and the three-phase output ends of the inverter are connected to the three-phase inputs of the mains input via three-phase switches; the control system includes: A first sampling unit, used for respectively acquiring first three-phase input parameters corresponding to the mains input when the three-phase switch and the neutral line switch are both disconnected; A first execution unit is used to close the neutral line switch when the first three-phase input parameter is within a normal range, so that the midpoint of the bus input of the inverter is connected to the neutral line input of the mains input; A second sampling unit, used for acquiring a second three-phase input parameter corresponding to the mains input, and adjusting the working state of the inverter according to the second three-phase input parameter; The second execution unit is used to close the three-phase switch when the output parameters corresponding to the three-phase output terminals of the inverter meet preset conditions, so that the inverter can be connected to the grid.

8. The inverter grid-connected startup control system according to claim 7, characterized in that: The control system further comprises: The alarm information generating unit is used to generate preset alarm information when the first three-phase input parameter is not within a normal range.

9. An electronic device, characterized in that: including memory and processor; The memory is used to store computer programs; The processor is configured to execute the computer program to implement the method according to any one of claims 1 to 6.

10. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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