Master-slave identification system and method for photovoltaic inverter

Abstract

The embodiment of the present invention relates to the field of new energy technology, and discloses a master-slave identification system and method for a photovoltaic inverter, the system comprising at least two photovoltaic inverters and at least two master-slave identification modules; a target photovoltaic inverter is used to output a target input level signal; a target master-slave identification module outputs a target output level signal according to the target input level signal; the target photovoltaic inverter collects the target output level signal and determines whether it is higher than a preset level threshold, and when it is higher, the target photovoltaic inverter is determined as the master; the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; after the remaining photovoltaic inverters collect the output level signals of the remaining master-slave identification modules, they set themselves as slaves. Through the above method, the embodiment of the present invention realizes the ability to quickly locate the master and slave.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of new energy technology, and in particular to a master-slave identification system and method for a photovoltaic inverter. Background Art

[0002] Photovoltaic inverters are mainly used to convert the high-voltage direct current generated by the photovoltaic array into sinusoidal alternating current for use by AC loads. As the capacity of the AC load's demand for electrical energy increases, the power of the photovoltaic inverter also becomes larger and larger. Continuously increasing the power of the photovoltaic inverter will, on the one hand, cause the appearance to become larger and larger, making it inconvenient to move and transport the inverter; on the other hand, it will increase the difficulty of selecting internal electronic components. In order to meet this demand, the function of connecting the output ends of multiple photovoltaic inverters in parallel to jointly bear the AC load that exceeds its own power has become a necessary function of photovoltaic inverters.

[0003] There are four main methods for controlling inverter parallel connection: master-slave control, centralized control, wireless parallel droop control, and instantaneous average current control. Both the master-slave control and centralized control schemes require that a master be identified in the parallel inverters, and the rest are slaves, so as to execute the subsequent parallel control strategy to achieve load power sharing. Currently, the commonly used methods for determining the master and slave are the address competition method and the pre-defined method. The address competition method requires the user to set the address of each inverter in the parallel inverters in advance and they cannot be repeated. The pre-defined method requires the user to set one of the parallel inverters as the master and the rest as slaves in advance. The above two schemes are cumbersome to implement and are not convenient for users. Summary of the invention

[0004] In view of the above problems, an embodiment of the present invention provides a master-slave identification system and method for a photovoltaic inverter, which is used to solve the technical problem that the prior art cannot meet the requirements of each inverter module in the photovoltaic inverter parallel control strategy to quickly identify its own master and slave positioning.

[0005] According to one aspect of an embodiment of the present invention, a master-slave identification system of a photovoltaic inverter is provided, the system comprising at least two photovoltaic inverters and at least two master-slave identification modules; one photovoltaic inverter corresponds to one master-slave identification module;

[0006] The target photovoltaic inverter is used to output a target input level signal to a target master-slave identification module; the target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is a master-slave identification module corresponding to the target photovoltaic inverter;

[0007] The target master-slave identification module is used to output a target output level signal according to the target input level signal;

[0008] The target photovoltaic inverter is further used to collect the target output level signal and determine whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, determine the target photovoltaic inverter as the host;

[0009] The target master-slave identification module is further used to send a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules;

[0010] The remaining photovoltaic inverters are further used to set themselves as slaves after collecting the output level signals of the remaining master-slave identification modules; the remaining photovoltaic inverters are the photovoltaic inverters other than the target photovoltaic inverter among the at least two photovoltaic inverters.

[0011] In an optional manner, the target photovoltaic inverter includes a target processor, a target sampling module and a target driving module;

[0012] The target driving module is used to output a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on;

[0013] The target sampling module is used to collect the target output level signal;

[0014] The target processor is used to determine whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, determine the target photovoltaic inverter as the host.

[0015] In an optional manner, the target processor is used to output a control signal to the target drive module when the target photovoltaic inverter is powered on, so that the target drive module outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on;

[0016] The target processor is further used to control the target sampling module to collect the target output level signal output by the target master-slave identification module.

[0017] In an optional manner, the target processor is further used to send a bus signal to the remaining master-slave identification modules after the target photovoltaic inverter is determined to be the master, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal.

[0018] In an optional manner, the target processor is further used to send a bus signal to the remaining master-slave identification modules after the target photovoltaic inverter is determined to be the master, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal.

[0019] In an optional manner, the target master-slave identification module includes an optical coupling module U6, an optical coupling module U8, a transistor Q3, a transistor Q4, a diode D7, a diode D8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16 and a capacitor C8;

[0020] Among them, the positive electrode of the light-emitting diode of the optocoupler module U8 is connected to the negative electrode of the diode D7 and the diode D8, and the positive electrode of the diode D7 is connected to the power supply of 15 volts; the negative electrode of the light-emitting diode of the optocoupler module U8 is connected to the positive electrode of the diode D8 and the 1-pin of the resistor R16, the negative electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the capacitor C8 and the power ground, the positive electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the resistor R9 and the resistor R10, the 1-pin of the resistor R9 is connected to the power supply of 3.3 volts, the 1-pin of the resistor R10 is connected to the 1-pin of the capacitor C8 and the photovoltaic inverter, the positive electrode of the light-emitting diode of the optocoupler module U6 is connected to the 2-pin of the resistor R11, and the 1-pin of the resistor R11 is connected to the Pin 1 and the power supply of 3.3 volts, the cathode of the light-emitting diode of the optocoupler module U6 is connected to pin 2 of the resistor R14, pin 1 of the resistor R14 is connected to the emitter of the transistor Q3, the base of the transistor Q3 is connected to pin 2 of the resistor R12 and the photovoltaic inverter, the collector of the transistor Q3 is connected to the power ground, the anode of the photosensitive diode of the optocoupler module U6 is connected to the power supply of 15 volts, the cathode of the photosensitive diode of the optocoupler module U6 is connected to pin 1 of R15, pin 2 of the resistor R15 is connected to pin 1 of the resistor R13 and the base of the transistor Q4, pin 2 of the resistor R13 is connected to the emitter of the transistor Q4 and the power ground, the collector of the transistor Q4 is connected to pin 2 of the resistor R16 and the remaining master-slave identification modules.

[0021] In an optional manner, the preset level threshold is 1.6V; and the target input level signal is a high level signal.

[0022] According to another aspect of an embodiment of the present invention, a method for identifying a master and a slave of a photovoltaic inverter is provided. The method is based on the master and slave identification system of the photovoltaic inverter described above; the method comprises:

[0023] When the target photovoltaic inverter is powered on and initialized, the target photovoltaic inverter outputs a target input level signal to a target master-slave identification module; the target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is a master-slave identification module corresponding to the target photovoltaic inverter;

[0024] The target photovoltaic inverter collects the target output level signal of the target master-slave identification module, and determines whether the target output level signal is higher than a preset level threshold;

[0025] When the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master, and the target master-slave identification module sends a bus signal to the remaining master-slave identification modules to make the output level signals of the remaining master-slave identification modules lower than the preset level threshold; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules;

[0026] After collecting the output level signal of the remaining master-slave identification module, the remaining photovoltaic inverter sets itself as a slave; the remaining photovoltaic inverter is the photovoltaic inverter other than the target photovoltaic inverter among the at least two photovoltaic inverters.

[0027] In an optional manner, the target driving module of the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on;

[0028] The target photovoltaic inverter collects the target output level signal of the target master-slave identification module and determines whether the target output level signal is higher than a preset level threshold, further comprising:

[0029] The target sampling module of the target photovoltaic inverter collects the target output level signal;

[0030] The target processor of the target photovoltaic inverter determines whether the target output level signal is higher than a preset level threshold, and determines the target photovoltaic inverter as a host when the target output level signal is higher than the preset level threshold.

[0031] In an optional manner, after the sampling modules of the remaining photovoltaic inverters collect the output level signals of the remaining master-slave identification modules and set themselves as slaves, the method further includes:

[0032] The target master-slave identification module acts as a host and executes a host program;

[0033] The remaining photovoltaic inverters serve as slaves and execute slave programs.

[0034] The embodiment of the present invention is provided with at least two photovoltaic inverters and at least two master-slave identification modules; one photovoltaic inverter corresponds to one master-slave identification module, and the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module; the target master-slave identification module outputs a target output level signal according to the target input level signal; the target photovoltaic inverter collects the target output level signal and determines whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master; the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules; after the remaining photovoltaic inverter collects the output level signal of the remaining master-slave identification module, it sets itself as a slave, so that the photovoltaic inverter as the master can be quickly identified, and the rapid positioning of the master and slave is realized.

[0035] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0037] Figure 1 A schematic diagram of the structure of a master-slave identification system for a photovoltaic inverter provided by an embodiment of the present invention is shown;

[0038] Figure 2 A schematic diagram of the circuit structure of a master-slave identification module in a master-slave identification system of a photovoltaic inverter provided by an embodiment of the present invention is shown;

[0039] Figure 3 A schematic diagram of the judgment logic flow of a processor of a photovoltaic inverter in a master-slave identification system of a photovoltaic inverter provided by an embodiment of the present invention is shown;

[0040] Figure 4 A schematic flow chart of a method for identifying a master and a slave of a photovoltaic inverter provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0041] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0042] Figure 1 The schematic diagram of the structure of the master-slave identification system of the photovoltaic inverter provided by the embodiment of the present invention is shown. The system includes at least two photovoltaic inverters and at least two master-slave identification modules. Among them, one photovoltaic inverter corresponds to one master-slave identification module.

[0043] In an embodiment of the present invention, the target photovoltaic inverter is used to output a target input level signal to a target master-slave identification module. The target output level signal is a high level. The target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is a master-slave identification module corresponding to the target photovoltaic inverter. Specifically, the target photovoltaic inverter includes a target processor, a target sampling module and a target drive module electrically connected to each other. When the target photovoltaic inverter is powered on, the target processor outputs a control signal to the target drive module so that the target drive module outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on. The target drive module is connected to the signal input terminal (HOST_TXD) of the target master-slave identification module, and is used to output the target input level signal to the target master-slave identification module according to the control signal when the target photovoltaic inverter is powered on.

[0044] The target master-slave identification module is used to output a target output level signal according to the target input level signal. The target photovoltaic inverter collects the target output level signal and determines whether the target output level signal is higher than a preset level threshold. When the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the host. Specifically, the target sampling module is connected to the signal input terminal (HOST_RXD) of the target master-slave identification module for collecting the target output level signal. The target processor is used to determine whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the host. When the target processor determines that the target output level signal is higher than the preset level threshold, it sets the target photovoltaic inverter itself as the host and controls the target drive module to output a low level to execute the corresponding host program.

[0045] The target master-slave identification module is also used to send a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal. The remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules. The remaining photovoltaic inverters are also used to set themselves as slaves after collecting the output level signals of the remaining master-slave identification modules. Among them, the remaining photovoltaic inverters are photovoltaic inverters other than the target photovoltaic inverter among the at least two photovoltaic inverters. Among them, at the beginning, the driving modules of each photovoltaic inverter all output a high level. After the driving module of the first photovoltaic inverter outputs a high level and is first determined as the master, the output end of the master-slave identification module connected to the driving module of the other remaining photovoltaic inverters is controlled by controlling the high and low of the bus signal to output a voltage lower than the preset level threshold, so that the acquisition module of the remaining photovoltaic inverter collects a voltage lower than the preset level threshold, thereby setting itself as a slave. After the remaining PV inverters are set as slaves, they control their own drive modules to output a low level and execute the slave program.

[0046] In the embodiment of the present invention, Figure 2As shown, the target master-slave identification module includes an optical coupling module U6, an optical coupling module U8, a transistor Q3, a transistor Q4, diodes D7, D8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16 and a capacitor C8. Among them, the positive electrode of the light-emitting diode of the optocoupler module U8 is connected to the negative electrode of the diode D7 and the diode D8, and the positive electrode of the diode D7 is connected to the power supply of 15 volts; the negative electrode of the light-emitting diode of the optocoupler module U8 is connected to the positive electrode of the diode D8 and the 1-pin of the resistor R16, the negative electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the capacitor C8 and the power ground, the positive electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the resistor R9 and the resistor R10, the 1-pin of the resistor R9 is connected to the power supply of 3.3 volts, the 1-pin of the resistor R10 is connected to the 1-pin of the capacitor C8 and the photovoltaic inverter, the positive electrode of the light-emitting diode of the optocoupler module U6 is connected to the 2-pin of the resistor R11, and the 1-pin of the resistor R11 is connected to the Pin 1 and the power supply of 3.3 volts, the cathode of the light-emitting diode of the optocoupler module U6 is connected to pin 2 of the resistor R14, pin 1 of the resistor R14 is connected to the emitter of the transistor Q3, the base of the transistor Q3 is connected to pin 2 of the resistor R12 and the photovoltaic inverter, the collector of the transistor Q3 is connected to the power ground, the anode of the photosensitive diode of the optocoupler module U6 is connected to the power supply of 15 volts, the cathode of the photosensitive diode of the optocoupler module U6 is connected to pin 1 of R15, pin 2 of the resistor R15 is connected to pin 1 of the resistor R13 and the base of the transistor Q4, pin 2 of the resistor R13 is connected to the emitter of the transistor Q4 and the power ground, the collector of the transistor Q4 is connected to pin 2 of the resistor R16 and the remaining master-slave identification modules.

[0047] Among them, when the target photovoltaic inverter is powered on, the target drive module is initialized to output the target input level signal to the HOST_TXD of the master-slave identification module. The target input level signal is a high level signal, so that the transistor Q3 is in the cut-off state. At this time, the two diodes inside the optocoupler of the optocoupler module U6 are in the cut-off state, the transistor Q4 is in the cut-off state, HOST_BUS+ is pulled up to 15 volts, the two diodes inside the U8 optocoupler are in the cut-off state, HOST_RXD is pulled up to 3.3 volts, and the target sampling module of the target photovoltaic inverter samples HO The voltage of the target output level signal on ST_RXD is recorded as V1, and compared with the preset voltage threshold, which can be set to 1.65V. If the voltage of the target output level signal is greater than the set voltage of 1.65V, the target photovoltaic inverter determines that the machine is the host to execute the host program, controls the target drive module to output a low level to the HOST_TXD of the master-slave identification module, the transistor Q3 is in the on state, the two diodes inside the optocoupler module U6 are in the on state, Q4 is in the on state, and HOST_BUS+ is pulled down to the ground. When the photovoltaic inverter is powered on later, HOST_RXD will be pulled down to the ground, and the voltage V1 collected by the inverter is smaller than the set voltage of 1.65V, and it sets itself as a slave to execute the slave program, thereby realizing its own master-slave positioning.

[0048] Among them, Figure 3 As shown, in the embodiment of the present invention, the logic flow of the target photovoltaic inverter executing the master-slave judgment includes the following steps:

[0049] start;

[0050] S1: Power-on initialization controls the drive module to output a high level;

[0051] S2: voltage V1 of the target output level signal on the sampling module HOST_RXD;

[0052] S3: The processor determines whether V1 is less than 1.65V: if it is greater than or equal to 1.65V, execute step S4; if it is less than 1.65V, execute step S6;

[0053] S4: Set this machine as the host and make the driver module output low level;

[0054] S5: Execute host program;

[0055] S6: Set this machine as a slave;

[0056] S7: execute slave program;

[0057] Finish.

[0058] The embodiment of the present invention is provided with at least two photovoltaic inverters and at least two master-slave identification modules; one photovoltaic inverter corresponds to one master-slave identification module, and the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module; the target master-slave identification module outputs a target output level signal according to the target input level signal; the target photovoltaic inverter collects the target output level signal and determines whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master; the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules; after the remaining photovoltaic inverter collects the output level signal of the remaining master-slave identification module, it sets itself as a slave, so that the photovoltaic inverter as the master can be quickly identified, and the rapid positioning of the master and slave is realized.

[0059] Figure 4 FIG. 2 is a flow chart of a master-slave identification method of a photovoltaic inverter provided by another embodiment of the present invention, which is based on the master-slave identification system of the photovoltaic inverter of the aforementioned embodiment. Figure 4 As shown, the method comprises the following steps:

[0060] Step 110: When the target photovoltaic inverter is powered on and initialized, the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module. Wherein, the target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is the master-slave identification module corresponding to the target photovoltaic inverter. Wherein, the target drive module of the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on.

[0061] Step 120: The target photovoltaic inverter collects the target output level signal of the target master-slave identification module, and determines whether the target output level signal is higher than a preset level threshold. The target sampling module of the target photovoltaic inverter collects the target output level signal, and the target processor of the target photovoltaic inverter determines whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master.

[0062] Step 130: When the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master, and the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the output level signals of the remaining master-slave identification modules are lower than the preset level threshold. The remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules.

[0063] Step 140: After collecting the output level signal of the remaining master-slave identification module, the remaining photovoltaic inverters set themselves as slaves; the remaining photovoltaic inverters are the photovoltaic inverters of the at least two photovoltaic inverters except the target photovoltaic inverter.

[0064] The method further includes: the target master-slave identification module acts as a host to control the target drive module to output a low-level signal and execute a host program; and the remaining photovoltaic inverters act as slaves to execute slave programs.

[0065] Among them, the specific implementation steps of the method are generally consistent with the functions performed by each module or device in the above-mentioned system embodiment, and will not be repeated here.

[0066] The embodiment of the present invention is provided with at least two photovoltaic inverters and at least two master-slave identification modules; one photovoltaic inverter corresponds to one master-slave identification module, and the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module; the target master-slave identification module outputs a target output level signal according to the target input level signal; the target photovoltaic inverter collects the target output level signal and determines whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master; the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification signal among the at least two master-slave identification modules; after the remaining photovoltaic inverter collects the output level signal of the remaining master-slave identification module, it sets itself as a slave, so that the photovoltaic inverter as the master can be quickly identified, and the rapid positioning of the master and slave is realized.

[0067] The algorithm or display provided herein is not inherently related to any particular computer, virtual system or other equipment. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious to construct the structure required for this type of system. In addition, the embodiment of the present invention is not directed to any specific programming language yet. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the description made to specific languages ​​above is for disclosing the best mode of the present invention.

[0068] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0069] Similarly, it should be understood that in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than those expressly recited in each claim.

[0070] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and set in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0071] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A master-slave identification system for a photovoltaic inverter, characterized in that: The system includes at least two photovoltaic inverters and at least two master-slave identification modules; one photovoltaic inverter corresponds to one master-slave identification module; A target photovoltaic inverter, used to output a target input level signal to a target master-slave identification module; the target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is a master-slave identification module corresponding to the target photovoltaic inverter; The target master-slave identification module is used to output a target output level signal according to the target input level signal; The target photovoltaic inverter is further used to collect the target output level signal and determine whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, determine the target photovoltaic inverter as the host; The target master-slave identification module is further used to send a bus signal to the remaining master-slave identification modules, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification module among the at least two master-slave identification modules; The remaining photovoltaic inverters are further used to set themselves as slaves after collecting the output level signals of the remaining master-slave identification modules; the remaining photovoltaic inverters are the photovoltaic inverters other than the target photovoltaic inverter among the at least two photovoltaic inverters.

2. The system according to claim 1, characterized in that The target photovoltaic inverter includes a target processor, a target sampling module and a target driving module; The target driving module is used to output a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on; The target sampling module is used to collect the target output level signal; The target processor is used to determine whether the target output level signal is higher than a preset level threshold, and when the target output level signal is higher than the preset level threshold, determine the target photovoltaic inverter as the host.

3. The system according to claim 2, characterized in that The target processor is used to output a control signal to the target drive module when the target photovoltaic inverter is powered on, so that the target drive module outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on; The target processor is further used to control the target sampling module to collect the target output level signal output by the target master-slave identification module.

4. The system according to claim 2, characterized in that The target processor is further configured to send a bus signal to the remaining master-slave identification modules after the target photovoltaic inverter is determined to be the master, so that the remaining master-slave identification modules output an output level signal lower than the preset level threshold according to the bus signal.

5. The system according to claim 2, characterized in that The target photovoltaic inverter is further used to control the target driving module to output a low-level signal after determining the target photovoltaic inverter as a host, so that the target photovoltaic inverter executes a host program.

6. The system according to claim 1, characterized in that The target master-slave identification module includes an optical coupling module U6, an optical coupling module U8, a transistor Q3, a transistor Q4, a diode D7, a diode D8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16 and a capacitor C8; Among them, the positive electrode of the light-emitting diode of the optocoupler module U8 is connected to the negative electrode of the diode D7 and the diode D8, and the positive electrode of the diode D7 is connected to the power supply of 15 volts; the negative electrode of the light-emitting diode of the optocoupler module U8 is connected to the positive electrode of the diode D8 and the 1-pin of the resistor R16, the negative electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the capacitor C8 and the power ground, the positive electrode of the photosensitive diode of the optocoupler module U8 is connected to the 2-pin of the resistor R9 and the resistor R10, the 1-pin of the resistor R9 is connected to the power supply of 3.3 volts, the 1-pin of the resistor R10 is connected to the 1-pin of the capacitor C8 and the photovoltaic inverter, the positive electrode of the light-emitting diode of the optocoupler module U6 is connected to the 2-pin of the resistor R11, and the 1-pin of the resistor R11 is connected to the Pin 1 and the power supply of 3.3 volts, the cathode of the light-emitting diode of the optocoupler module U6 is connected to pin 2 of the resistor R14, pin 1 of the resistor R14 is connected to the emitter of the transistor Q3, the base of the transistor Q3 is connected to pin 2 of the resistor R12 and the photovoltaic inverter, the collector of the transistor Q3 is connected to the power ground, the anode of the photosensitive diode of the optocoupler module U6 is connected to the power supply of 15 volts, the cathode of the photosensitive diode of the optocoupler module U6 is connected to pin 1 of R15, pin 2 of the resistor R15 is connected to pin 1 of the resistor R13 and the base of the transistor Q4, pin 2 of the resistor R13 is connected to the emitter of the transistor Q4 and the power ground, the collector of the transistor Q4 is connected to pin 2 of the resistor R16 and the remaining master-slave identification modules.

7. The system according to claim 6, characterized in that The target input level signal is a high level signal; the preset level threshold is 1.6V.

8. A method for identifying a master and a slave of a photovoltaic inverter, characterized in that: The method is based on the master-slave identification system of the photovoltaic inverter according to any one of claims 1 to 7; the method comprises: When the target photovoltaic inverter is powered on and initialized, the target photovoltaic inverter outputs a target input level signal to a target master-slave identification module; the target photovoltaic inverter is any one of at least two photovoltaic inverters, and the target master-slave identification module is a master-slave identification module corresponding to the target photovoltaic inverter; The target photovoltaic inverter collects the target output level signal of the target master-slave identification module, and determines whether the target output level signal is higher than a preset level threshold; When the target output level signal is higher than the preset level threshold, the target photovoltaic inverter is determined as the master, and the target master-slave identification module sends a bus signal to the remaining master-slave identification modules, so that the output level signals of the remaining master-slave identification modules are lower than the preset level threshold; the remaining master-slave identification modules are the master-slave identification modules other than the target master-slave identification module among the at least two master-slave identification modules; After collecting the output level signal of the remaining master-slave identification module, the remaining photovoltaic inverter sets itself as a slave; the remaining photovoltaic inverter is the photovoltaic inverter other than the target photovoltaic inverter among the at least two photovoltaic inverters.

9. The method according to claim 8, characterized in that When the target photovoltaic inverter is powered on and initialized, the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module, further comprising: The target driving module of the target photovoltaic inverter outputs a target input level signal to the target master-slave identification module when the target photovoltaic inverter is powered on; The target photovoltaic inverter collects the target output level signal of the target master-slave identification module and determines whether the target output level signal is higher than a preset level threshold, further comprising: The target sampling module of the target photovoltaic inverter collects the target output level signal; The target processor of the target photovoltaic inverter determines whether the target output level signal is higher than a preset level threshold, and determines the target photovoltaic inverter as a host when the target output level signal is higher than the preset level threshold.

10. The method according to claim 8 or 9, characterized in that: After the sampling modules of the remaining photovoltaic inverters collect the output level signals of the remaining master-slave identification modules and set themselves as slaves, the method further includes: The target master-slave identification module acts as a host, controls the target drive module to output a low-level signal, and executes the host program; The remaining photovoltaic inverters serve as slaves and execute slave programs.

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