A hybrid inverter anti-backflow control method, system, device and medium

Abstract

The present invention discloses a hybrid inverter anti-backflow control method and system, equipment, and medium, the method comprising: obtaining a load current and an output current of an inverter, performing differential operation on the output current and the load current to obtain a differential current; extracting a mutation current in the differential current, performing resonance analysis on the mutation current to obtain a current instruction, performing PI regulation on the current instruction to obtain a voltage deviation value; obtaining a grid-side current of a grid-side electric meter, adjusting the input voltage of a photovoltaic MPPT port of an inverter according to the grid-side current, performing maximum power tracking according to the input voltage to obtain a working voltage; performing integral regulation on the working voltage and the voltage deviation value, determining the regulation instruction input to the inner loop controller of the inverter to regulate the output current of the inverter. The grid-side current fed back to the grid is made zero to achieve the purpose of preventing backflow, enhance the anti-backflow control accuracy, and ensure the response accuracy of the grid current without backflow.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid control, and in particular to a hybrid inverter backflow prevention control method and system, equipment and medium. Background Art

[0002] However, in a photovoltaic system, when the power of the photovoltaic system is greater than the power of the local load, the unabsorbed electricity must be sent to the grid. Since the direction of this energy flow is photovoltaic components-inverter-load-grid, it is different from the current direction of the grid system and is called "reverse flow".

[0003] In the existing technology, when photovoltaic inverters convert the direct current generated by photovoltaic modules into alternating current, there will be DC components and harmonics, output power uncertainty, etc., and there is basically no effective control measure. Therefore, when the generated power is sent to the public power grid, it will cause harmonic pollution to the power grid, which is easy to cause grid voltage fluctuations and flicker. When too much power is sent to the grid at the same time, it will not only lead to a decline in power quality, but also cause some electrical faults due to the old wires. Summary of the invention

[0004] The purpose of the present invention is to provide a hybrid inverter anti-backflow control method and system, equipment, and medium to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0005] The solution of the present invention to solve the technical problem is to provide a hybrid inverter anti-backflow control method and system, equipment and medium.

[0006] According to an embodiment of the first aspect of the present invention, a hybrid inverter backflow prevention control method is provided, which is applied to a photovoltaic system, wherein the photovoltaic system includes an inverter, a photovoltaic module and a grid-side electric meter; the photovoltaic module is connected to the inverter, the inverter is connected to the grid through the grid-side electric meter, the grid-side electric meter is communicatively connected to the inverter, and the inverter is connected to the load, and the method includes:

[0007] Obtaining a load current and an output current of an inverter, performing a differential operation on the output current and the load current to obtain a differential current;

[0008] Extracting a sudden change current from the differential current, performing resonance analysis on the sudden change current to obtain a current instruction, performing PI adjustment on the current instruction to obtain a voltage deviation value;

[0009] Obtaining the grid-side current of the grid-side electric meter, adjusting the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current, performing maximum power tracking according to the input voltage, and obtaining the working voltage;

[0010] The operating voltage and the voltage deviation value are integrally regulated to determine a regulation instruction input to an inner loop controller of the inverter so as to regulate the output current of the inverter.

[0011] Further, the extracting the sudden change current in the differential current specifically includes:

[0012] Inputting the differential current into a bandpass notch filter to obtain a first current;

[0013] The first current is subtracted from the differential current to obtain a non-fundamental current component, and the non-fundamental current component is used as the mutation current.

[0014] Further, the analyzing the mutation current specifically includes:

[0015] Inputting the sudden change current into the photovoltaic system and obtaining an output test current;

[0016] According to the sudden current and the test current, determining whether the sudden current causes the photovoltaic system to resonate;

[0017] If not, the sudden change current is used as the current instruction.

[0018] Further, the determining whether the sudden current causes the photovoltaic system to resonate specifically includes:

[0019] When the test current is greater than 1.5 times the mutation current, it is considered that the mutation current causes the photovoltaic system to resonate.

[0020] Further, adjusting the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current specifically includes:

[0021] When the grid-side current is greater than a set threshold, the power of the maximum power tracking is reduced.

[0022] According to an embodiment of the second aspect of the present invention, a hybrid inverter backflow prevention system is provided, which is applied to a photovoltaic system, wherein the photovoltaic system includes an inverter, a photovoltaic module and a grid-side electric meter; the photovoltaic module is connected to the inverter, the inverter is connected to the grid through the grid-side electric meter, the grid-side electric meter is communicatively connected to the inverter, and the inverter is connected to the load, and the system includes:

[0023] A differential operation module, used for obtaining a load current and an output current of an inverter, performing a differential operation on the output current and the load current to obtain a differential current;

[0024] An extraction and analysis module is used to extract a sudden change current in the differential current, perform resonance analysis on the sudden change current to obtain a current instruction, perform PI regulation on the current instruction to obtain a voltage deviation value;

[0025] An MPPT adjustment module is used to obtain the grid-side current of the grid-side electric meter, adjust the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current, perform maximum power tracking according to the input voltage, and obtain the working voltage;

[0026] The integral regulation module is used to perform integral regulation on the working voltage and the voltage deviation value, and determine the regulation instruction input to the inner loop controller of the inverter to regulate the output current of the inverter.

[0027] Further, the extraction and analysis module includes:

[0028] A bandpass notch filter, used for processing the differential current to extract a first current;

[0029] The mutation current extraction unit is used to subtract the first current from the differential current to obtain a non-fundamental current component, and use the non-fundamental current component as the mutation current.

[0030] Furthermore, the extraction and analysis module also includes:

[0031] A test unit, used for inputting the sudden change current into the photovoltaic system and obtaining an output test current;

[0032] A resonance analysis unit, used for judging whether the sudden current causes the photovoltaic system to resonate according to the sudden current and the test current;

[0033] The current instruction confirmation unit is used to confirm that the sudden change current does not cause the photovoltaic system to resonate and then use the sudden change current as the current instruction.

[0034] According to an embodiment of a third aspect of the present invention, there is provided a computer device, comprising:

[0035] a memory storing a computer program;

[0036] A processor, wherein when executing the computer program, the processor implements a hybrid inverter backflow prevention control method as described in the embodiment of the first aspect.

[0037] According to an embodiment of a fourth aspect of the present invention, there is provided a storage medium comprising: storing computer executable instructions, wherein the computer executable instructions are used to execute a hybrid inverter backflow prevention control method as described in the embodiment of the first aspect of the present invention.

[0038] The beneficial effects of the present invention are: by differential control of the output current and the load current, the output current of the inverter is regulated so that the grid-side current fed back to the grid is zero, so as to achieve the purpose of preventing reverse flow. On the basis of the most anti-reverse flow of the grid-connected current, the differential control of the output current of the inverter and the load current is superimposed to obtain the voltage deviation value, and the voltage deviation value is used as the precise compensation of the MPPT control, and the integral link of the inner loop controller is used to superimpose it on the voltage loop control, so as to enhance the anti-reverse flow control accuracy and ensure the response accuracy of the grid current without reverse flow.

[0039] It solves the problem that the specified no-backflow control accuracy is limited by the communication speed, and also solves the resonance problem caused by the controller's anti-backflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic flow chart of a hybrid inverter anti-backflow control method provided by the present invention;

[0041] Figure 2 It is a partial framework schematic diagram of a photovoltaic system provided by the present invention;

[0042] Figure 3 It is a partial framework schematic diagram of a hybrid inverter backflow prevention system provided by the present invention;

[0043] Figure 4 It is a partial framework schematic diagram of an extraction and analysis module of a hybrid inverter backflow prevention system provided by the present invention;

[0044] Figure 5 The present invention provides an internal structure diagram of a computer device. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and cannot be understood as limiting the present invention.

[0046] It should be noted that although the functional modules are divided in the system diagram, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0048] EPS is also known as emergency power supply, the full name is Emergency Power Supply.

[0049] The full name of MPPT controller is "Maximum Power Point Tracking" solar controller.

[0050] Reference Figure 2 The present invention is applied to a photovoltaic system, which includes: an inverter, a photovoltaic module, a grid-side electric meter and a battery.

[0051] The photovoltaic module is connected to the photovoltaic MPPT port of the inverter, the inverter is connected to the battery, the grid port of the inverter is connected to the grid through the grid-side meter, the grid-side meter is connected to the inverter through communication, and the EPS port of the inverter is connected to the load.

[0052] Reference Figure 1 According to some embodiments of the first aspect of the present invention, a hybrid inverter anti-reverse flow control method, using the above photovoltaic system, includes the following methods:

[0053] S100, obtaining a load current and an output current of an inverter, performing a differential operation on the output current and the load current to obtain a differential current.

[0054] In this embodiment, the output end of the inverter is sampled by Hall to obtain the output current, and the EPS port of the inverter is sampled by Hall to obtain the load current. The output current and the load current are differentially processed to obtain the differential current.

[0055] S200, extracting the sudden change current in the differential current, performing resonance analysis on the sudden change current to obtain a current instruction, performing PI adjustment on the current instruction to obtain a voltage deviation value.

[0056] In this embodiment, the differential current is extracted to obtain a sudden change current, and resonance analysis is performed on the sudden change current to determine that the sudden change current will not cause system resonance, thereby determining a current instruction to ensure that the photovoltaic system does not generate a higher resonance frequency.

[0057] The current command is PI-regulated, and after proportional-integral control, the voltage deviation value is output as precise compensation for MPPT control.

[0058] S300, obtaining the grid-side current of the grid-side electric meter, adjusting the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current, performing maximum power tracking according to the input voltage, and obtaining the working voltage.

[0059] In this embodiment, the grid-side electric meter is sampled to obtain the grid-side current, which is fed back to the inverter. The input voltage of the photovoltaic MPPT port is adjusted by the grid-side current.

[0060] By communicating the grid-side electric meter with the inverter and feeding the grid-side current back to the inverter, the problem that the prescribed non-reverse current control accuracy is limited by the communication speed is solved.

[0061] Through the adjusted input voltage, the maximum power of the current photovoltaic system is tracked to obtain the working voltage corresponding to the current maximum power.

[0062] S400, integrally adjusting the operating voltage and the voltage deviation value, and determining an adjustment instruction input to an inner loop controller of the inverter to adjust the output current of the inverter.

[0063] In this embodiment, the operating voltage obtained in S300 and the voltage deviation value obtained in S200 are used to perform integral regulation by utilizing the integral link of the controller to determine the regulation instruction.

[0064] Since the grid-connected control mainly uses the DC bus voltage control as the outer loop control and the grid-connected AC current control as the inner loop control, the adjustment command is input into the inner loop controller of the inverter, wherein the inner loop controller includes: a voltage PI controller and a current PI controller.

[0065] According to the regulation instruction, the voltage PI controller and the current PI controller operate in sequence to adjust the output current of the inverter so that the grid-side current fed back to the grid is zero to prevent reverse flow. This reduces the generation of extra power and ensures the response accuracy of the grid current without reverse flow.

[0066] In the scheme of the above-mentioned embodiment, this scheme achieves the purpose of preventing backflow by making the grid-side current fed back to the grid zero. On the basis of preventing the backflow of the grid-connected current, the differential control of the output current of the inverter and the load current is superimposed to obtain the voltage deviation value, and the voltage deviation value is used as the precise compensation of the MPPT control. The integral link of the inner loop controller is used to superimpose it on the voltage loop control to enhance the anti-backflow control accuracy and ensure the response accuracy of the grid current without backflow. It solves the problem that the prescribed non-backflow control accuracy is limited by the communication speed, and also solves the resonance problem caused by the controller's anti-backflow.

[0067] In some embodiments of the first aspect of the present invention, in S200, the process of extracting the sudden change current specifically includes:

[0068] S210, the differential current passes through a bandpass notch filter to obtain a first current.

[0069] S220, subtracting the first current from the differential current to obtain a non-fundamental current component, which is used as a mutation current.

[0070] In this embodiment, the differential current I delta That is the grid current I grid , after passing through the bandpass notch filter, the first current I is obtained grid_notch , and then with the grid current I grid Subtract the non-fundamental current component I harm =I grid_notch -I grid .

[0071] The non-fundamental current component is used as the mutation current to achieve extraction. Since the mutation component of the current is the most difficult to control and belongs to the high-order component, it is easy to cause system resonance.

[0072] In some embodiments of the first aspect of the present invention, in S200, the analysis process of the sudden change current specifically includes:

[0073] S230, inputting the sudden change current as a test instruction into the photovoltaic system, and obtaining the test current output corresponding to the sudden change current as the input.

[0074] S240, using the sudden current and the test current, determining whether the sudden current will cause system resonance.

[0075] S241, if not, the sudden change current is used as the current command to perform PI regulation.

[0076] In this embodiment, since the photovoltaic system is a closed-loop control, the entire control gain is 1. Therefore, the judgment basis for the resonance of the photovoltaic system is to convert the sudden change current (i.e., the non-fundamental current component I harm ) is brought into the photovoltaic system control as a test instruction to obtain the output current component, namely the test current.

[0077] The sudden current and the test current are used to analyze whether the sudden current will cause system resonance. In some embodiments, the determination process of system resonance in S240 specifically includes:

[0078] If the test current is greater than the sudden change current (i.e. the non-fundamental current component I harm ) is 1.5 times, then the sudden change current (i.e. the non-fundamental current component I harm ) causes the photovoltaic system to resonate, otherwise, the photovoltaic system is normal.

[0079] When the sudden current (i.e. the non-fundamental current component I harm ) cannot cause system resonance. When the photovoltaic system is normal, the sudden current (i.e., the non-fundamental current component I harm) is used as the current command output to perform PI adjustment on the current command. After proportional integral control, the voltage deviation value is output as the precise compensation for MPPT control.

[0080] Through S210 to S241, the sudden change current is extracted and analyzed to determine whether it will cause system resonance, thereby solving the resonance problem caused by the controller's anti-backflow function.

[0081] In some embodiments of the first aspect of the present invention, in S300, the input voltage adjustment process specifically includes:

[0082] S310: If the grid-side current is greater than the set threshold, it is necessary to reduce the maximum power tracking power.

[0083] In this embodiment, since the inverter cannot be directly regulated, the inverter control closed loop controls the inverter's own output current as a closed loop. Therefore, if the grid-side current is greater than the set threshold, the MPPT power needs to be reduced, and the input voltage of the photovoltaic MPPT port is increased, otherwise the input voltage of the photovoltaic MPPT port is reduced. To achieve regulation of the inverter, the threshold is set to zero.

[0084] Reference Figure 3 According to some embodiments of the second aspect of the present invention, a hybrid inverter backflow prevention system, applying the above-mentioned photovoltaic system, the backflow prevention system includes: a differential operation module, an extraction and analysis module, an MPPT regulation module and an integral regulation module.

[0085] The differential operation module performs Hall sampling on the output end of the inverter to obtain the output current, and performs Hall sampling on the EPS port of the inverter to obtain the load current; and performs differential operation processing using the output current and the load current to obtain the differential current.

[0086] The extraction and analysis module extracts the differential current to obtain the mutation current, performs resonance analysis on the mutation current, determines that the mutation current will not cause system resonance, and determines the current command. The current command is PI-regulated, and after proportional-integral control, the voltage deviation value is output as precise compensation for MPPT control.

[0087] The MPPT adjustment module samples the grid-side meter to obtain the grid-side current and feeds the grid-side current back to the inverter. The input voltage of the photovoltaic MPPT port is adjusted through the grid-side current. The maximum power of the current photovoltaic system is tracked through the adjusted input voltage to obtain the working voltage corresponding to the current maximum power.

[0088] By communicating the grid-side electric meter with the inverter and feeding the grid-side current back to the inverter, the problem that the prescribed non-reverse current control accuracy is limited by the communication speed is solved.

[0089] The integral regulation module uses the operating voltage obtained by the MPPT regulation module and the voltage deviation value obtained in the extraction and analysis module, and uses the integral link of the controller to perform integral regulation, determine the regulation instruction, and adjust the output current of the inverter through the regulation instruction.

[0090] In some embodiments, since the grid-connected control mainly uses the DC bus voltage control as the outer loop control and the grid-connected AC current control as the inner loop control, the adjustment instruction is input into the inner loop controller of the inverter, wherein the inner loop controller includes: a voltage PI controller and a current PI controller.

[0091] According to the regulation instruction, the voltage PI controller and the current PI controller operate in sequence to adjust the output current of the inverter so that the grid-side current fed back to the grid is zero to prevent reverse flow. This reduces the generation of extra power and ensures the response accuracy of the grid current without reverse flow.

[0092] In the scheme of the above-mentioned embodiment, this scheme achieves the purpose of preventing backflow by making the grid-side current fed back to the grid zero. On the basis of preventing the backflow of the grid-connected current, the differential control of the output current of the inverter and the load current is superimposed to obtain the voltage deviation value, and the voltage deviation value is used as the precise compensation of the MPPT control. The integral link of the inner loop controller is used to superimpose it on the voltage loop control to enhance the anti-backflow control accuracy and ensure the response accuracy of the grid current without backflow. It solves the problem that the prescribed non-backflow control accuracy is limited by the communication speed, and also solves the resonance problem caused by the controller's anti-backflow.

[0093] Reference Figure 4 According to some embodiments of the second aspect of the present invention, the extraction and analysis module includes: a bandpass notch filter, a sudden current extraction unit, a testing unit, a resonance analysis unit, a current instruction confirmation unit and a current PI regulator.

[0094] The bandpass notch filter processes the differential current to obtain a first current.

[0095] The sudden change current extraction unit subtracts the first current from the differential current to obtain the non-fundamental current component I harm , the non-fundamental current component is taken as the mutation current to achieve extraction.

[0096] In this embodiment, the differential current I delta That is the grid current I grid , after passing through the bandpass notch filter, the first current I is obtained grid_notch , and then with the grid current I grid Subtract the non-fundamental current component I harm =I grid_notch -I grid .

[0097] The non-fundamental current component is used as the mutation current to achieve extraction. Since the mutation component of the current is the most difficult to control and belongs to the high-order component, it is easy to cause system resonance.

[0098] The test unit will change the sudden current (i.e. the non-fundamental current component I harm ) is brought into the photovoltaic system control as a test instruction to obtain the test current output by the photovoltaic system.

[0099] The resonance analysis unit uses the sudden current and the test current to determine whether the sudden current will cause system resonance.

[0100] In this embodiment, if the test current is greater than the sudden change current (ie, the non-fundamental current component I harm ) is 1.5 times, then the sudden change current (i.e. the non-fundamental current component I harm ) causes the photovoltaic system to resonate, otherwise, the photovoltaic system is normal.

[0101] The current command confirmation unit determines the sudden change current (i.e. the non-fundamental current component I harm ) cannot cause system resonance. When the photovoltaic system is normal, the sudden current (i.e., the non-fundamental current component I harm ) is used as the current command output.

[0102] The current command passes through the current PI regulator and, after proportional-integral control, the output voltage deviation value is used as precise compensation for MPPT control.

[0103] In the solution of the above embodiment, the resonance problem caused by the controller's anti-backflow is solved by extracting the sudden change current and analyzing it to determine whether it will cause system resonance.

[0104] According to an embodiment of a third aspect of the present invention, a computer device is provided.

[0105] See also Figure 5 , Figure 5 FIG. 1 is an internal structure diagram of a computer device according to an embodiment. Figure 5 As shown, the computer device includes a processor, a memory and a database connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. When the computer program is executed by the processor, a hybrid inverter anti-backflow control method described in the first aspect is implemented.

[0106] The memory and the processor components are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The processor includes at least one software function module that can be stored in the memory in the form of software or firmware or solidified in the operating system (OS) of the server. The processor is used to execute the executable module stored in the memory.

[0107] The memory may be a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc. The memory is used to store programs and voice data, and the processor executes the program after receiving the execution instruction.

[0108] The processor may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0109] The processor couples various input / output devices to the processor and the memory. In some embodiments, the processor and the memory can be implemented in a single chip. In some other examples, they can be implemented by separate chips respectively.

[0110] The peripheral interface couples various input / output devices to the processor and the memory. In some embodiments, the peripheral interface, the processor and the memory can be implemented in a single chip. In some other examples, they can be implemented by separate chips respectively.

[0111] According to an embodiment of the fourth aspect of the present invention, a computer storage medium is further provided, wherein a computer program is stored in the computer storage medium, and the computer storage medium may be a magnetic random access memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a flash memory, a magnetic surface memory, an optical disk, or a read-only optical disk, etc.; or may be various devices including one or any combination of the above memories, such as a mobile phone, a computer, a tablet device, a personal digital assistant, etc. When the computer program is executed by a processor, a hybrid inverter anti-backflow control method described in the first aspect is implemented.

[0112] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0114] The preferred embodiments of the present invention are described in detail above, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A hybrid inverter anti-backflow control method, characterized in that: Applied to a photovoltaic system, the photovoltaic system includes an inverter, a photovoltaic module and a grid-side electric meter; the photovoltaic module is connected to the inverter, the inverter is connected to the power grid through the grid-side electric meter, the grid-side electric meter is communicatively connected to the inverter, and the inverter is connected to the load, the method includes: Obtaining a load current and an output current of an inverter, performing a differential operation on the output current and the load current to obtain a differential current; Extracting a sudden change current from the differential current, performing resonance analysis on the sudden change current to obtain a current instruction, performing PI adjustment on the current instruction to obtain a voltage deviation value; Obtaining the grid-side current of the grid-side electric meter, adjusting the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current, performing maximum power tracking according to the input voltage, and obtaining the working voltage; Integrally regulating the operating voltage and the voltage deviation value to determine a regulation instruction input to an inner loop controller of the inverter to regulate the output current of the inverter; The extracting the sudden change current in the differential current specifically includes: Inputting the differential current into a bandpass notch filter to obtain a first current; The first current is subtracted from the differential current to obtain a non-fundamental current component, and the non-fundamental current component is used as the mutation current.

2. A hybrid inverter backflow prevention control method according to claim 1, characterized in that: The analyzing the sudden change current specifically includes: Inputting the sudden change current into the photovoltaic system and obtaining an output test current; According to the sudden current and the test current, determining whether the sudden current causes the photovoltaic system to resonate; If not, the sudden change current is used as the current instruction.

3. A hybrid inverter anti-backflow control method according to claim 2, characterized in that: The determining whether the sudden current causes the photovoltaic system to resonate specifically includes: When the test current is greater than 1.5 times the mutation current, it is considered that the mutation current causes the photovoltaic system to resonate.

4. The method for controlling backflow prevention of a hybrid inverter according to claim 1, characterized in that: The step of adjusting the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current specifically includes: When the grid-side current is greater than a set threshold, the power of the maximum power tracking is reduced.

5. A hybrid inverter backflow prevention system, characterized in that: Applied to a photovoltaic system, the photovoltaic system includes an inverter, a photovoltaic module and a grid-side electric meter; the photovoltaic module is connected to the inverter, the inverter is connected to the power grid through the grid-side electric meter, the grid-side electric meter is connected to the inverter in communication, and the inverter is connected to the load. The system includes: A differential operation module, used for obtaining a load current and an output current of an inverter, performing a differential operation on the output current and the load current to obtain a differential current; An extraction and analysis module is used to extract a sudden change current in the differential current, perform resonance analysis on the sudden change current to obtain a current instruction, perform PI regulation on the current instruction to obtain a voltage deviation value; An MPPT adjustment module is used to obtain the grid-side current of the grid-side electric meter, adjust the input voltage of the photovoltaic MPPT port of the inverter according to the grid-side current, perform maximum power tracking according to the input voltage, and obtain the working voltage; An integral regulation module, used for performing integral regulation on the operating voltage and the voltage deviation value, and determining a regulation instruction input to an inner loop controller of the inverter to regulate the output current of the inverter; The extraction and analysis module comprises: A bandpass notch filter, used for processing the differential current to extract a first current; The mutation current extraction unit is used to subtract the first current from the differential current to obtain a non-fundamental current component, and use the non-fundamental current component as the mutation current.

6. A hybrid inverter backflow prevention system according to claim 5, characterized in that: The extraction and analysis module also includes: A test unit, used for inputting the sudden change current into the photovoltaic system and obtaining an output test current; A resonance analysis unit, used for judging whether the sudden current causes the photovoltaic system to resonate according to the sudden current and the test current; The current instruction confirmation unit is used to confirm that the sudden change current does not cause the photovoltaic system to resonate and then use the sudden change current as the current instruction.

7. A computer device, characterized in that: include: a memory storing a computer program; A processor, wherein when executing the computer program, the processor implements the hybrid inverter anti-backflow control method as described in any one of claims 1 to 4.

8. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a hybrid inverter backflow prevention control method as claimed in any one of claims 1 to 4 is implemented.

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