Photovoltaic inverter system and negative reverse connection detection method thereof

Abstract

The invention discloses a photovoltaic inverter system and a negative reverse connection detection method thereof, the photovoltaic inverter system comprises n power converters and n photovoltaic panels, n is a positive integer greater than or equal to 2, each power converter comprises an input end, the input end is used for connecting the photovoltaic panels, the input end comprises a positive input terminal and a negative input terminal, the photovoltaic panel comprises a positive output terminal and a negative output terminal; the negative reverse connection detection method comprises the following steps: (a1) selecting one power converter as a to-be-detected power converter; (a2) controlling n-1 power converters except the power converter to be detected to stop outputting power; (a3) obtaining n-1 current values of the negative input terminals of the n-1 power converters; (a4) determining that the photovoltaic panel of the to-be-detected power converter is a negative reverse connection photovoltaic panel when determining that a current value in the n-1 current values is greater than a preset value; and (b) returning to the step (a1) until negative reverse connection detection of all the power converters is completed. According to the invention, the negative reverse connection photovoltaic panel in the power conversion system can be determined.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic inverter technology, and in particular to a photovoltaic inverter system and a negative reverse connection detection method thereof. Background Art

[0002] At present, photovoltaic inverter systems are generally equipped with multiple photovoltaic panel inputs, that is, multiple power converters can be set in the photovoltaic inverter system, and each power converter is used to connect a photovoltaic panel and track the maximum power point of the photovoltaic panel. However, when the appearance and structure of the connection terminals are the same, it is inevitable that the photovoltaic panel will be reversely connected, that is, the negative output of the photovoltaic panel is connected to the negative input of other power converters, so that the maximum power point tracking of the power converter corresponding to the photovoltaic panel will fail, thereby affecting the normal operation of the photovoltaic inverter system. Summary of the invention

[0003] In view of this, the present application provides a photovoltaic inverter system and a negative reverse connection detection method thereof, which are used to detect and determine all negative reverse connection photovoltaic panels in a power conversion system, so that the user can adjust the connection of the negative output terminal of the negative reverse connection photovoltaic panel to avoid abnormal MPPT tracking of the photovoltaic panel due to negative reverse connection, thereby affecting the normal operation of the photovoltaic inverter system. The technical solution of the present application is as follows: The first aspect of the present application provides a negative reverse connection detection method for a photovoltaic inverter system, wherein the photovoltaic inverter system comprises n power converters and n photovoltaic panels, where n is a positive integer greater than or equal to 2, the power converter comprises an input end, the input end is used to connect the photovoltaic panel, the input end comprises a positive input terminal and a negative input terminal, the photovoltaic panel comprises a positive output terminal and a negative output terminal, the positive input terminal is used to connect the positive output terminal, and the negative input terminal is used to connect the negative output terminal; the negative reverse connection detection method comprises: (a1) selecting one of the power converters as a power converter to be detected; (a2) controlling n-1 power converters other than the power converter to be detected to stop outputting power; (a3) ​​obtaining n-1 current values ​​of the negative input terminals of the n-1 power converters; (a4) determining that when there is a current value greater than a preset value among the n-1 current values, determining that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse connection photovoltaic panel; and (b) returning to step (a1) until negative reverse connection detection is completed for all the power converters.

[0004] In one embodiment of the present application, each of the power converters includes a current sampling circuit, and the current sampling circuit is arranged at the negative input terminal; step (a3) ​​includes: obtaining n-1 current values ​​through the current sampling circuits of n-1 power converters.

[0005] In one embodiment of the present application, all the negative input terminals are controlled in common, and the negative reverse connection detection method further includes: (a4) determining a target current sampling circuit corresponding to a current value greater than a preset value among the n-1 current sampling circuits, and associating the target current sampling circuit with the current negative reverse connection photovoltaic panel; wherein the target current sampling circuit is used to provide the target current sampling value required for MPPT calculation for the associated negative reverse connection photovoltaic panel.

[0006] In one embodiment of the present application, the negative reverse connection detection method also includes: (a5) determining the target negative input terminal corresponding to the current value in n-1 current sampling circuits being greater than a preset value, associating the target negative input terminal with the negative input terminal of the current power converter to be detected, and recording the associated information.

[0007] In an embodiment of the present application, the negative reverse connection detection method further includes: upon receiving a negative reverse connection self-test instruction, executing step (a1).

[0008] According to a second aspect of the present application, there is provided a photovoltaic inverter system, comprising n power converters, n photovoltaic panels and a controller, wherein n is a positive integer greater than or equal to 2, wherein the power converter comprises an input end, wherein the input end is used to connect the photovoltaic panel, wherein the input end comprises a positive input terminal and a negative input terminal, wherein the photovoltaic panel comprises a positive output terminal and a negative output terminal, wherein the positive input terminal is used to connect the positive output terminal, and the negative input terminal is used to connect the negative output terminal; wherein the controller is connected to the power converter, wherein the controller is used to select one of the power converters as a power converter to be detected after receiving a negative reverse connection self-test instruction, control n-1 power converters other than the power converter to be detected to stop outputting power, obtain n-1 current values ​​of the negative input terminals of the n-1 power converters, and when it is determined that there is a current value greater than a preset value among the n-1 current values, determine that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse connection photovoltaic panel, and return to selecting one of the power converters as the power converter to be detected until all the power converters are detected.

[0009] In one embodiment of the present application, each of the power converters includes a current sampling circuit and a power conversion circuit, and the negative input terminal is connected to the negative input terminal of the power conversion circuit through the current sampling circuit; the controller is connected to each of the current sampling circuits, and the controller is used to obtain n-1 current values ​​through the current sampling circuits of n-1 power converters.

[0010] In one embodiment of the present application, all the negative input terminals are commonly controlled, and the controller is also used to determine the target current sampling circuit corresponding to the current value of n-1 current sampling circuits that is greater than the preset value, and associate the target current sampling circuit with the current negative reverse-connected photovoltaic panel.

[0011] In one embodiment of the present application, the power converter further includes a voltage sampling circuit, which is connected to the negative input terminal and the positive input terminal of the power converter; the voltage sampling circuit is used to obtain a voltage sampling value.

[0012] In one embodiment of the present application, the controller is also used to obtain the target current sampling value of the target current sampling circuit associated with the negative reverse photovoltaic panel and the voltage sampling value after completing the negative reverse connection detection and restarting the photovoltaic inverter system, and perform MPPT tracking on the power conversion circuit corresponding to the negative reverse photovoltaic panel based on the target current sampling value and the voltage sampling value.

[0013] The present application selects one of the power converters in the photovoltaic inverter system as the power converter to be detected, and controls the remaining power converters to stop outputting power. When the power converter to be detected outputs power normally, the current values ​​of the negative input terminals of the remaining power converters that have stopped outputting power are obtained. If there is a current value greater than a preset value among the obtained current values, it means that the photovoltaic panel corresponding to the power converter to be detected is negatively reversed to other power converters. The detection process is repeated, and finally all the negatively reversed photovoltaic panels in the power conversion system can be determined, so that the user can adjust the connection of the negative output terminal of the negatively reversed photovoltaic panel to avoid abnormal MPPT tracking of the photovoltaic panel due to negative reverse connection, which affects the normal operation of the photovoltaic inverter system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic block diagram of a photovoltaic inverter system provided in an embodiment of the present application.

[0015] Figure 2 It is a schematic block diagram of a photovoltaic panel negative reverse connection provided in an embodiment of the present application.

[0016] Figure 3 It is a flow chart of a negative reverse connection detection method for a photovoltaic inverter system provided in an embodiment of the present application.

[0017] Figure 4 It is a schematic block diagram of another photovoltaic inverter system provided in an embodiment of the present application.

[0018] Figure 5 It is a flow chart of a second negative reverse connection detection method for a photovoltaic inverter system provided in an embodiment of the present application.

[0019] Figure 6 It is a flow chart of a third negative reverse connection detection method for a photovoltaic inverter system provided in an embodiment of the present application.

[0020] Figure 7 It is a flow chart of a fourth negative reverse connection detection method for a photovoltaic inverter system provided in an embodiment of the present application.

[0021] Figure 8 It is a schematic block diagram of a photovoltaic inverter system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0023] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0024] At present, photovoltaic inverter systems are generally equipped with multiple photovoltaic panel inputs, that is, multiple power converters can be set in the photovoltaic inverter system, and each power converter is used to connect a photovoltaic panel and track the maximum power point of the photovoltaic panel. However, when the appearance and structure of the connection terminals are the same, it is inevitable that the photovoltaic panel will be reversely connected, that is, the negative output of the photovoltaic panel is connected to the negative input of other power converters, so that the maximum power point tracking of the power converter corresponding to the photovoltaic panel will fail, thereby affecting the normal operation of the photovoltaic inverter system.

[0025] The present application provides a photovoltaic inverter system and a negative reverse connection detection method thereof, which are used to detect and determine all negative reverse connected photovoltaic panels in a power conversion system, so as to facilitate the user to adjust the connection of the negative output terminal of the negative reverse connected photovoltaic panel, and avoid abnormal MPPT tracking of the photovoltaic panel due to negative reverse connection, thereby affecting the normal operation of the photovoltaic inverter system.

[0026] Please refer to Figure 1 , Figure 1Schematic block diagram of a photovoltaic inverter system provided in an embodiment of the present application, wherein the photovoltaic inverter system 100 includes n power converters 110 and n photovoltaic panels 120, where n is a positive integer greater than or equal to 2 ( Figure 1 Example n=2).

[0027] In the embodiment of the present application, each power converter 110 includes an input terminal, and the power converter 110 is connected to the photovoltaic panel 120 through the input terminal, and the input terminal includes a positive input terminal V+ and a negative input terminal V-. Each photovoltaic panel 120 includes a positive output terminal PV+ and a negative output terminal PV-, and the positive input terminal V+ is used to connect to the positive output terminal PV+, and the negative input terminal V- is used to connect to the negative output terminal PV-.

[0028] In some application scenarios, such as Figure 2 As shown, when the photovoltaic panel 120 of the photovoltaic inverter system 100 is connected to the power converter 110, there is a situation where the negative output terminal PV- and the negative input terminal V- are connected incorrectly, that is, the photovoltaic panel 120 and the power converter 110 are negatively reversed.

[0029] like Figure 2 As shown in , the photovoltaic inverter system 100 includes a power converter 110a, a power converter 110b, a photovoltaic panel 120a and a photovoltaic panel 120b, the positive output terminal PV1+ of the photovoltaic panel 120a is connected to the positive input terminal V1+ of the power converter 110a, the negative output terminal PV1- of the photovoltaic panel 120a is connected to the negative input terminal V2- of the power converter 110b, the positive output terminal PV2+ of the photovoltaic panel 120b is connected to the positive input terminal V2+ of the power converter 110b, and the negative output terminal PV2- of the photovoltaic panel 120b is connected to the negative input terminal V1- of the power converter 1101. That is, the power converter 110a, the power converter 110b, the photovoltaic panel 120a, and the photovoltaic panel 120b are negatively reversed, which causes the power converter 110a to be unable to obtain the correct current data of the photovoltaic panel 120a for MPPT tracking (maximum power point tracking), and causes the power converter 110b to be unable to obtain the correct current data of the photovoltaic panel 120b for MPPT tracking.

[0030] Next, combine Figure 1 and Figure 2 A negative reverse connection detection method for a photovoltaic inverter system provided in an embodiment of the present application is introduced. Figure 3 As shown, the following steps are included: Step S31: selecting one of the power converters as the power converter to be detected.

[0031] In an embodiment of the present application, the photovoltaic inverter system also includes a controller, and each power converter can be connected to the controller, which controls the power converter to work, so as to control the power converter to convert the electrical energy of the photovoltaic panel into a target voltage output, and control the power converter to track the maximum power point of the electrical energy of the photovoltaic panel.

[0032] Among them, the controller can enter the negative reverse connection detection state after receiving the user's instructions. After entering the negative reverse connection detection state, one of the power converters will be selected as the power converter to be detected, and then it will be detected whether the photovoltaic panel corresponding to the power converter to be detected is negatively reversed, that is, whether the negative output terminal of the corresponding photovoltaic panel is connected to the negative input terminal of another power converter.

[0033] In some embodiments, the controller may select one of the power converters in sequence according to the numbers of the power converters as the power converter to be detected.

[0034] Step S32: controlling n-1 power converters except the power converter to be detected to stop outputting power.

[0035] In an embodiment of the present application, after selecting the power converter to be detected, the controller controls the remaining power converters except the power converter to be detected to stop outputting power. For example, the controller can control the output ends of n-1 power converters to disconnect from the lower-level circuits, or the controller can also use software to block the power conversion circuits in the n-1 power converters, or the controller can also disconnect the power conversion circuits in the n-1 power converters from the input terminals.

[0036] Step S33: Obtain n-1 current values ​​of the negative input terminals of n-1 power converters.

[0037] In the embodiment of the present application, after the controller controls n-1 power converters other than the power converter to be detected to stop outputting power, it will obtain n-1 current values ​​of the negative input terminals of the n-1 power converters. It can be understood that the n-1 power converters have stopped outputting power. If there is a larger current value among the obtained n-1 current values, it means that the photovoltaic panel corresponding to the power converter to be detected is negatively reversed, that is, the negative output terminal of the corresponding photovoltaic panel is connected to the negative input terminal of one of the n-1 power converters.

[0038] Step S34: when it is determined that there is a current value greater than a preset value among the n-1 current values, it is determined that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse photovoltaic panel.

[0039] In an embodiment of the present application, after obtaining n-1 current values, the controller can use the n-1 current values ​​to compare with the preset values ​​one by one. When it is determined that one of the current values ​​is greater than the preset value, it is determined that the photovoltaic panel corresponding to the power converter to be detected is negatively reversed to other power converters.

[0040] In some embodiments, the controller can mark the negatively connected photovoltaic panel and the corresponding power converter, for example, mark the negatively connected photovoltaic panel and the correct corresponding power converter, and mark the reversely connected power converter, record and output the corresponding marking information, so that the user can connect the negative output terminal of the negatively connected photovoltaic panel to the negative input terminal of the correct power converter according to the marking information.

[0041] In order to prevent the zero drift of the current of the power converter from affecting the current value, the preset value needs to be set to a larger value. And because the power generation power of the photovoltaic panel is related to the light intensity, taking a larger preset value may result in a shorter time period for negative reverse connection detection, so the preset value can be obtained according to the corresponding photovoltaic panel and power converter test. In some embodiments, the preset value can be 1.5A (ampere) to 3.0A.

[0042] Step S35: Return to step S31 until negative reverse connection detection is completed for all power converters.

[0043] In an embodiment of the present application, after determining whether the photovoltaic panel corresponding to the current power converter to be detected is reversely connected, the controller will select another power converter as the next power converter to be detected, and repeat the above steps until the negative reverse connection detection of all power converters is completed.

[0044] It can be understood that the present application selects one of the power converters in the photovoltaic inverter system as the power converter to be detected, and controls the remaining power converters to stop outputting power. When the power converter to be detected outputs power normally, the current value of the negative input terminal of the remaining power converters that stop outputting power is obtained. If there is a current value greater than the preset value among the obtained current values, it means that the photovoltaic panel corresponding to the power converter to be detected is negatively reverse connected to other power converters. The detection process is repeated, and finally all the negatively reversed photovoltaic panels in the power conversion system can be determined, so that the user can adjust the connection of the negative output terminal of the negatively reversed photovoltaic panel to avoid abnormal MPPT tracking of the photovoltaic panel due to negative reverse connection, which affects the normal operation of the photovoltaic inverter system.

[0045] In some embodiments, Figure 4As shown, each power converter 110 of the photovoltaic inverter system 100a includes a current sampling circuit 111, and the current sampling circuit 111 is arranged at the negative input terminal V-, that is, the current sampling circuit 111 is respectively connected to the negative input terminal V- and the input negative pole of the power converter 110, so that the current sampling circuit 111 is arranged before the wire of the negative output terminal PV1- of the photovoltaic panel 120 and the common control ground, so that the common mode noise is smaller. The current sampling circuit 111 can be used to collect the input current of the photovoltaic panel 120. All negative input terminals V- are controlled to the common ground.

[0046] Please refer to Figure 5 , Figure 5 A schematic flow chart of a second method for detecting negative reverse connection of a photovoltaic inverter system provided in an embodiment of the present application, wherein: Figure 5 The negative reverse connection detection method shown includes steps S51-S52, S54-S55, and Figure 3 Steps S31-S32 and S34-S35 of the negative reverse connection detection method shown in the figure are the same and will not be repeated here. The difference is that: Figure 5 The negative reverse detection method shown includes: Step S53: obtaining n-1 current values ​​through the current sampling circuits of n-1 power converters.

[0047] In an embodiment of the present application, the controller may be connected to the current sampling circuits of each power converter. When performing negative reverse connection detection, the controller obtains n-1 current values ​​through the current sampling circuits of n-1 power converters.

[0048] Please refer to Figure 6 , Figure 6 A schematic flow chart of a third method for detecting negative reverse connection of a photovoltaic inverter system provided in an embodiment of the present application, wherein: Figure 6 The negative reverse connection detection method shown includes steps S61 to S64, S66, and Figure 5 Steps S51 to S55 of the negative reverse connection detection method shown in the figure are the same and will not be repeated here. The difference is that: Figure 6 The negative reverse connection detection method shown also includes: Step S65: determining a target current sampling circuit whose current value among the n-1 current sampling circuits is greater than the preset value, and associating the target current sampling circuit with the current negative reverse-connected photovoltaic panel.

[0049] The target current sampling circuit is used to provide the target current sampling value required for MPPT calculation for the associated negative reverse photovoltaic panel. It can be understood that after associating the target current sampling circuit with the current negative reverse photovoltaic panel, the controller can record the corresponding association information.

[0050] In an embodiment of the present application, after the negative reverse connection detection is completed, when the controller controls the power conversion circuit to perform MPPT tracking of the corresponding photovoltaic panel, it is determined that the photovoltaic panel is a negative reverse connection photovoltaic panel, and the corresponding associated information is obtained. According to the associated information, the current sampling value of the corresponding target current sampling circuit is obtained as the current data required for the negative reverse connection photovoltaic panel MPPT calculation, so that the user does not need to manually adjust the connection of the negative output terminal of the negative reverse connection photovoltaic panel, and the normal operation of the photovoltaic inverter system can be ensured.

[0051] Please refer to Figure 7 , Figure 7 A schematic flow chart of a fourth method for detecting negative reverse connection of a photovoltaic inverter system provided in an embodiment of the present application includes the following steps: Step S71: When receiving the negative reverse connection self-test instruction, execute step S72.

[0052] In the embodiment of the present application, the controller can be connected to the user's mobile device or network platform through remote communication, and the user can send a negative reverse connection self-test instruction to the photovoltaic inverter system by operating the mobile device or network platform.

[0053] Step S72: Select one of the power converters as the power converter to be detected.

[0054] Step S73: Control n-1 power converters except the power converter to be detected to stop outputting power.

[0055] Step S74: Obtain n-1 current values ​​of the negative input terminals of n-1 power converters.

[0056] Step S75: When it is determined that there is a current value greater than a preset value among the n-1 current values, it is determined that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse photovoltaic panel.

[0057] Step S76: determining the target negative input terminal corresponding to the current value greater than the preset value in the n-1 current sampling circuits, associating the target negative input terminal with the negative input terminal of the current power converter to be detected, and recording the associated information.

[0058] In an embodiment of the present application, the controller can also associate the target negative input terminal with the negative input terminal of the current power converter to be detected, and record the associated information. After the negative reverse connection detection is completed, the user can remove the connecting wire on the target negative input terminal according to the associated information, and connect the connecting wire to the negative input terminal of the correct power converter, thereby connecting the negative output terminal of the negative reverse connection photovoltaic panel to the correct negative input terminal.

[0059] Step S77: Return to step S72 until negative reverse connection detection is completed for all power converters.

[0060] In some embodiments, after completing the negative reverse connection detection for all power converters and determining all negative reverse connected photovoltaic panels, the controller of the photovoltaic inverter system can also directly replace the current sampling channel of the negative reverse connected photovoltaic panel, that is, obtain the correct current sampling value of the current sampling circuit to perform MPPT tracking to ensure that the photovoltaic inverter system continues to operate normally. At the same time, the user is notified of the information related to the replacement of the current sampling channel so that the user can also restore the factory settings of the photovoltaic inverter system and adjust the connection of the negative output terminal of the negative reverse connected photovoltaic panel.

[0061] Please refer to Figure 8 , Figure 8 Schematic block diagram of a photovoltaic inverter system provided in an embodiment of the present application, the photovoltaic inverter system 800 includes n power converters 810, n photovoltaic panels 820 and a controller 830, where n is a positive integer greater than or equal to 2 ( Figure 8 Example is 2).

[0062] In an embodiment of the present application, the power converter 810 includes an input end, which is used to connect to the photovoltaic panel 820. The input end includes a positive input terminal and a negative input terminal. The photovoltaic panel 820 includes a positive output terminal and a negative output terminal. The positive input terminal is used to connect to the positive output terminal, and the negative input terminal is used to connect to the negative output terminal.

[0063] The controller 830 is connected to the power converter 810. The controller 830 is used to select one of the power converters 810 as the power converter 810 to be detected after receiving the negative reverse connection self-test instruction, control n-1 power converters 810 except the power converter 810 to be detected to stop outputting power, obtain n-1 current values ​​of the negative input terminals of the n-1 power converters 810, and when it is determined that there is a current value greater than a preset value among the n-1 current values, determine that the photovoltaic panel 820 corresponding to the power converter 810 to be detected is a negative reverse connection photovoltaic panel 820, and return to selecting one of the power converters 810 as the power converter 810 to be detected until all power converters 810 are detected.

[0064] Each power converter 810 includes a current sampling circuit 811 and a power conversion circuit 812, and the negative input terminal is connected to the negative input terminal of the power conversion circuit 812 through the current sampling circuit 811. The controller 830 is connected to each current sampling circuit 811, and the controller 830 is used to obtain n-1 current values ​​through the current sampling circuits 811 of n-1 power converters 810.

[0065] In some embodiments, all negative input terminals are controlled together, and the controller 830 is also used to determine the target current sampling circuit 811 whose current value among n-1 current sampling circuits 811 is greater than the preset value, and associate the target current sampling circuit 811 with the current negative reverse photovoltaic panel 820.

[0066] In some embodiments, the power converter 810 further includes a voltage sampling circuit 813, and the voltage sampling circuit 813 is connected to the negative input terminal and the positive input terminal of the power converter 810. The voltage sampling circuit 813 is used to obtain a voltage sampling value.

[0067] Among them, the controller 830 is also used to obtain the target current sampling value of the target current sampling circuit 811 associated with the negative reverse connection photovoltaic panel 820 and obtain the voltage sampling value after completing the negative reverse connection detection and restarting the photovoltaic inverter system 800, and perform MPPT tracking on the power conversion circuit 812 corresponding to the negative reverse connection photovoltaic panel 820 according to the target current sampling value and the voltage sampling value.

[0068] An embodiment of the present application further provides a computer storage medium, which stores a computer program. When the computer program is executed by a processor, the processor executes the above-mentioned negative reverse connection detection method.

[0069] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer storage medium or transmitted through a computer storage medium. The computer instructions can be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer storage medium can be any available medium that can be accessed by the computer or a data storage device such as a server or a data center that contains one or more available media integrated. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, digital versatile discs (DVD)), or semiconductor media (eg, solid state disks (SSD)), etc.

[0070] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes. In the absence of conflict, the technical features in this embodiment and the implementation scheme can be combined arbitrarily.

[0071] The above embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope of the claims of the present application.

Claims

1. A method for detecting negative reverse connection of a photovoltaic inverter system, characterized in that: The photovoltaic inverter system includes n power converters and n photovoltaic panels, where n is a positive integer greater than or equal to 2, the power converter includes an input end, the input end is used to connect the photovoltaic panel, the input end includes a positive input terminal and a negative input terminal, the photovoltaic panel includes a positive output terminal and a negative output terminal, the positive input terminal is used to connect the positive output terminal, and the negative input terminal is used to connect the negative output terminal; Negative reverse connection detection methods include: (a1) selecting one of the power converters as the power converter to be tested; (a2) controlling n-1 of the power converters except the power converter to be detected to stop outputting power; (a3) obtaining n-1 current values ​​of the negative input terminals of n-1 power converters; (a4) when it is determined that there is a current value greater than a preset value among the n-1 current values, determining that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse photovoltaic panel; (b) Return to step (a1) until negative reverse connection detection is completed for all the power converters.

2. The negative reverse connection detection method according to claim 1, characterized in that: Each of the power converters comprises a current sampling circuit, and the current sampling circuit is arranged at the negative input terminal; Step (a3) ​​comprises: The n-1 current values ​​are obtained through the current sampling circuits of the n-1 power converters.

3. The negative reverse connection detection method according to claim 2, characterized in that: All the negative input terminals are controlled to a common ground, and the negative reverse connection detection method further includes: (a4) determining a target current sampling circuit corresponding to a current value greater than a preset value among the n-1 current sampling circuits, and associating the target current sampling circuit with the current negative reverse-connected photovoltaic panel; The target current sampling circuit is used to provide the target current sampling value required for MPPT calculation for the associated negative reverse photovoltaic panel.

4. The negative reverse connection detection method according to claim 1, characterized in that: The negative reverse connection detection method further includes: (a5) Determine the target negative input terminal corresponding to the current value greater than the preset value in the n-1 current sampling circuits, associate the target negative input terminal with the negative input terminal of the current power converter to be detected, and record the association information.

5. The negative reverse connection detection method according to claim 1, characterized in that: The negative reverse connection detection method further includes: When a negative reverse connection self-test instruction is received, step (a1) is executed.

6. A photovoltaic inverter system, characterized in that: The invention comprises n power converters, n photovoltaic panels and a controller, wherein n is a positive integer greater than or equal to 2, wherein the power converter comprises an input end, wherein the input end is used to connect the photovoltaic panel, wherein the input end comprises a positive input terminal and a negative input terminal, wherein the photovoltaic panel comprises a positive output terminal and a negative output terminal, wherein the positive input terminal is used to connect the positive output terminal, and wherein the negative input terminal is used to connect the negative output terminal; The controller is connected to the power converter, and is used to select one of the power converters as the power converter to be detected after receiving a negative reverse connection self-test instruction, control n-1 power converters except the power converter to be detected to stop outputting power, obtain n-1 current values ​​of the negative input terminals of the n-1 power converters, and when it is determined that there is a current value greater than a preset value among the n-1 current values, determine that the photovoltaic panel corresponding to the power converter to be detected is a negative reverse connection photovoltaic panel, and return to selecting one of the power converters as the power converter to be detected until all the power converters are tested.

7. The photovoltaic inverter system according to claim 6, characterized in that: Each of the power converters comprises a current sampling circuit and a power conversion circuit, and the negative input terminal is connected to the negative input terminal of the power conversion circuit through the current sampling circuit; The controller is connected to each of the current sampling circuits, and is used to obtain n-1 current values ​​through the current sampling circuits of n-1 power converters.

8. The photovoltaic inverter system according to claim 7, characterized in that: All the negative input terminals are controlled in common, and the controller is also used to determine the target current sampling circuit corresponding to the current value greater than the preset value in the n-1 current sampling circuits, and associate the target current sampling circuit with the current negative reverse-connected photovoltaic panel.

9. The photovoltaic inverter system according to claim 8, characterized in that: The power converter further comprises a voltage sampling circuit, wherein the voltage sampling circuit is connected to the negative input terminal and the positive input terminal of the power converter; The voltage sampling circuit is used to obtain a voltage sampling value.

10. The photovoltaic inverter system according to claim 9, characterized in that: The controller is also used to obtain the target current sampling value of the target current sampling circuit associated with the negative reverse photovoltaic panel and the voltage sampling value after completing the negative reverse connection detection and restarting the photovoltaic inverter system, and perform MPPT tracking on the power conversion circuit corresponding to the negative reverse photovoltaic panel according to the target current sampling value and the voltage sampling value.

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