Inverter and main controller for photovoltaic system and method for operating solar system

Abstract

The invention provides a photovoltaic system. The photovoltaic system comprises a photovoltaic panel, a module-level power electronic device (MLPE) and a main controller, the MLPE sequentially stores N pieces of data in a first buffer (where N is a natural number greater than or equal to 2), the N pieces of data being obtained by accumulating energy output of the photovoltaic panel within each first set time; the main controller requests N pieces of data from the MLPE at each second set time, receives the N pieces of data from the MLPE, and stores the received data in a second buffer, the master controller updates a set of N pieces of second data by comparing the set of N pieces of second data previously stored in the second buffer with a set of N pieces of first data currently received from the MLPE.

Description

Technical Field

[0001] The present disclosure relates to an inverter and a main controller of a photovoltaic power generation system, and a photovoltaic power generation method. Background Art

[0002] Generally speaking, a photovoltaic power generation system is a system that uses photovoltaic cells to convert solar energy into electrical energy and transmits the electrical energy to a commercial power grid. This process does not cause environmental pollution and enables the photovoltaic power generation system to be used semi-permanently.

[0003] This photovoltaic power generation system includes multiple photovoltaic panels, multiple module-level power electronic devices (MLPE), a main controller and a server.

[0004] The plurality of photovoltaic panels may be connected in at least one of a series connection and a parallel connection, and each of the plurality of MLPEs may be provided for each of the plurality of photovoltaic panels.

[0005] Here, multiple MLPEs are set for multiple photovoltaic panels, the power generation efficiency of the photovoltaic panels is optimized, and power generation information (including power generation, temperature and fault information of the photovoltaic panels) is sent to a main controller or an inverter including the main controller.

[0006] The main controller controls the plurality of MLPEs, collects power generation information received from the plurality of MLPEs, and transmits the collected information to a server.

[0007] The server uses the power generation information of the plurality of photovoltaic panels to monitor the power generation status of the plurality of photovoltaic panels.

[0008] At the same time, cumulative power generation data is needed to quantitatively determine the power generation of photovoltaic panels.

[0009] To this end, the MLPE sequentially stores the cumulative power generation data of the photovoltaic panels in a buffer at preset time intervals, and responds to a request from the main controller by periodically sending the data stored in the buffer to the main controller.

[0010] If a communication failure occurs between the MLPE and the main controller, resulting in no communication for a certain period of time, the main controller may be unable to receive some data. Furthermore, due to system failures, the same data may be redundantly transmitted to the main controller. This can reduce data reliability. Furthermore, data reliability can vary depending on the communication environment, making it difficult to accurately monitor the cumulative power generation of the photovoltaic panels. Summary of the Invention

[0011] Technical issues

[0012] In order to solve the above-mentioned problems of the prior art, the present disclosure aims to prevent data loss even when a communication failure occurs and no communication is performed for a certain period of time, and to prevent duplicate data from being stored due to a system failure.

[0013] The technical problems to be solved by the present disclosure are not limited to the above-mentioned problems, and those skilled in the art to which the present disclosure belongs will clearly understand any other technical problems not mentioned herein from the following description.

[0014] Technical Solution

[0015] According to an embodiment of the present disclosure, a method for operating a photovoltaic power generation system is provided, the method comprising: generating power generation data, the power generation data being obtained by accumulating the power generation of the photovoltaic panel at each first set time; storing the power generation data in a first buffer in sequence; obtaining N power generation data stored in the first buffer as a first data set at each second set time, wherein N is a natural number greater than or equal to 2; comparing the second data set with the most recently obtained first data set, wherein the second data set is a set of M data previously stored in the second buffer, and M is a natural number greater than or equal to 2; and updating the second buffer based on the first data set in response to the comparison.

[0016] In the present disclosure, the comparison may include: searching whether the latest non-zero data (hereinafter referred to as the second cache latest data) exists in the second data set in an order opposite to the storage order of the second cache (hereinafter referred to as reverse order); and when the second cache latest data exists, searching whether the second cache latest data exists in the first data set according to the storage order of the first cache.

[0017] In the present disclosure, in updating, when the second buffer latest data exists in the first data set, at least one new data stored after the second buffer latest data may be stored in the second buffer.

[0018] In the present disclosure, during an update, when the number of at least one new data stored in the first data set after the latest data in the second cache is Nnew, the Nnew data can be stored in sequence in the (M-Nnew+1)th to Mth spaces in the storage space of the second cache.

[0019] In the present disclosure, in an update, data previously stored in the first to (M-Nnew)th cache spaces of the second cache may be deleted, and data stored in the (M-Nnew+1)th to Mth cache spaces may be newly stored in the first to (M-Nnew)th spaces.

[0020] In the present disclosure, during updating, when the latest data in the second buffer does not exist in the first data set, the first data set may be completely stored in the second buffer.

[0021] In the present disclosure, during the update, the first data set may be completely stored in sequence in the (M-N+1)th to Mth cache spaces of the second cache.

[0022] In the present disclosure, during updating, when the second data set does not contain the latest data of the second buffer, the first data set may be completely stored in the second buffer.

[0023] In the present disclosure, during the update, the first data set may be completely stored in sequence in the (M-N+1)th to Mth cache spaces of the second cache.

[0024] In the present disclosure, the first buffer may have a size configured to store up to N power generation amount data, and the second buffer may have a size configured to store up to M power generation amount data, where N is less than or equal to M.

[0025] According to an embodiment of the present disclosure, a main controller of a photovoltaic power generation system is provided, wherein the main controller is configured to: request a first data set stored in a first buffer of a module-level power electronic device (MLPE) of the photovoltaic power generation system from the MLPE; obtain the first data set from the MLPE; compare a second data set with a first data set most recently received from the MLPE, wherein the second data set is a set of M data previously stored in a second buffer of the main controller (where M is a natural number greater than or equal to 2); and update the second buffer based on the first data set in response to the comparison.

[0026] In the present disclosure, the first data set can be a set of N data (N is a natural number greater than or equal to 2), each of the N data is obtained by accumulating the power generation of the photovoltaic panel at each first set time, and the main controller can also be configured to request the first data set from the MLPE at each second set time.

[0027] In the present disclosure, the main controller can also be configured to: search whether there is the latest non-zero data (hereinafter referred to as the second cache latest data) in the second data in an order opposite to the storage order of the second cache (hereinafter referred to as reverse order); based on the existence of the second cache latest data, search whether there is the second cache latest data in the first data set according to the storage order of the first cache; and based on the existence of the second cache latest data in the first data set, store at least one new data stored after the second cache latest data in the second cache.

[0028] In the present disclosure, the main controller may be further configured to: search the second data set in reverse order for the presence of the second buffer's latest data; and based on the absence of the latest data in the second buffer, completely store the first data set in the second buffer.

[0029] In the present disclosure, the main controller can also be configured to: search in reverse order whether the latest data of the second cache exists in the second data set; based on the existence of the latest data of the second cache, search in the storage order of the first cache whether the latest data of the second cache exists in the first data set; and based on the absence of the second cache data in the first data set, completely store the first data set of N data in the second cache.

[0030] In the present disclosure, the first buffer may have a size configured to store up to N power generation amount data, and the second buffer may have a size configured to store up to M power generation amount data, where N may be a number less than or equal to M.

[0031] In the present disclosure, the MLPE may be configured to: after storing N power generation amount data in the first buffer, sequentially delete the power generation amount data according to the storage order of the first buffer, and sequentially store new data.

[0032] In the present disclosure, the main controller may be further configured to: after storing the second data set including M power generation data in the second buffer, sequentially delete the power generation data according to the storage order of the second buffer, and sequentially store new data.

[0033] According to an embodiment of the present disclosure, an inverter is provided, which includes a main controller of a photovoltaic power generation system, wherein the inverter is configured to: request a first data set stored in a first buffer of a module-level power electronic device MLPE of the photovoltaic power generation system from the MLPE; obtain the first data set from the MLPE; compare a second data set with a first data set most recently received from the MLPE, wherein the second data set is a set of M data previously stored in a second buffer of the main controller (where M is a natural number greater than or equal to 2); and update the second buffer based on the first data set in response to the comparison.

[0034] In the present disclosure, the first data set may be a set of N data (where N is a natural number greater than or equal to 2), each of the N data being obtained by accumulating the power generation of the photovoltaic panel at each first set time, and the main controller may be configured to request the first data set from the MLPE at each second set time.

[0035] Beneficial effects

[0036] According to the present disclosure, even if a communication failure occurs between the module-level power electronics (MLPE) and the main controller and no communication occurs for a certain period of time, data loss can be prevented, and duplicate data storage due to system failures can be prevented. This improves data reliability and enables accurate monitoring of the cumulative power generation of photovoltaic panels.

[0037] Effects obtained from the present disclosure are not limited to the above-mentioned effects, and any other effects not mentioned herein will be clearly understood from the following description by those skilled in the art to which the present disclosure pertains. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1A and Figure 1B is a schematic diagram illustrating a photovoltaic power generation system according to an embodiment of the present disclosure.

[0039] Figure 2 is a detailed block diagram of a module-level power electronics (MLPE) and a main controller according to an embodiment of the present disclosure.

[0040] Figure 3 is a flowchart illustrating a method of operating a photovoltaic power generation system according to an embodiment of the present disclosure.

[0041] Figure 4 A method in which MLPE stores data in a first buffer according to an embodiment of the present disclosure is shown.

[0042] Figure 5A and Figure 5B An example of updating the second buffer according to an embodiment of the present disclosure is shown.

[0043] Figure 6A and Figure 6B An example of updating the second buffer according to another embodiment of the present disclosure is shown.

[0044] Figure 7 An example of updating the second buffer according to another embodiment of the present disclosure is shown.

[0045] Figure 8 is a flowchart illustrating a method of updating cumulative power generation data of an MLPE according to an embodiment of the present disclosure.

[0046] Figure 9 is a detailed flowchart illustrating a method of updating the cumulative power generation amount data of the MLPE according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] The terms used in the examples are selected from commonly used terms as much as possible, but may vary depending on the intention of a person skilled in the art, precedents, or the emergence of new technologies. In addition, the applicant may arbitrarily select terms in specific circumstances, in which case the meaning of the terms will be described in detail in the corresponding sections. Therefore, the terms used herein should be defined according to their meaning and content throughout the specification, rather than by their names.

[0048] Throughout the specification, when a part is referred to as “comprising” a certain component, unless particularly stated otherwise, it means that it can further include other components rather than excluding other components.

[0049] In addition, terms including ordinal numbers used herein (such as "first" or "second") may be used to describe various components, but these components are not limited by the terms, and these terms are only used to distinguish one component from another. These terms may only be used to distinguish one component from another.

[0050] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. However, the embodiments may be implemented in many different forms and are not limited to the embodiments described below.

[0051] Figure 1A and Figure 1B is a schematic diagram illustrating a photovoltaic power generation system according to an embodiment of the present disclosure.

[0052] like Figure 1A As shown, the photovoltaic power generation system according to the embodiment of the present disclosure may include a plurality of photovoltaic panels 10, an inverter 400, a plurality of module-level power electronic devices (MLPE) 200 and a server 300, wherein the inverter 400 includes a main controller 100. Optionally, as Figure 1B As shown, a photovoltaic power generation system according to another embodiment of the present disclosure may include a plurality of photovoltaic panels 10 , a main controller 100 , a plurality of MLPEs 200 , an inverter 400 and a server 300 .

[0053] That is to say, if Figure 1A As shown, according to one embodiment, the photovoltaic power generation system may be configured such that the inverter 400 includes a main controller 100, and optionally, according to another embodiment, as shown Figure 1B As shown, the photovoltaic power generation system can be configured such that an inverter 400 is included between the main controller 100 and the grid 20. Here, the inverter 400 can convert the direct current (DC) power generated by the plurality of photovoltaic panels 10 into alternating current (AC) power and send the converted AC power to the grid 20. Figure 1AThe embodiment in which the main controller 100 is included in the inverter 400 is described as an example. In addition, in the following description, the plurality of photovoltaic panels 10 and the plurality of MLPEs 200 will be described together, but the photovoltaic panels 10 and the MLPEs 200 may also be independent of each other and configured as different types or models.

[0054] According to one embodiment, each of the plurality of photovoltaic panels 10 may be a photovoltaic power generation panel in a module unit. Furthermore, the plurality of photovoltaic panels 10 may be connected in at least one of a series connection and a parallel connection, and each of the plurality of MLPEs 200 may be provided for each of the plurality of photovoltaic panels 10. Furthermore, one MLPE 200 may be connected to one photovoltaic panel 10, or one MLPE 200 may be connected to multiple photovoltaic panels 10. The MLPE 200 may transmit power generation information (including power generation, temperature, and fault information of the photovoltaic panels 10) to the main controller 100, and may receive operation commands from the main controller 100 to optimize power efficiency.

[0055] Here, the information transmission and reception between the plurality of MLPEs 200 and the main controller 100 may be performed via power line communication (PLC).

[0056] The main controller 100 may collect power generation information received from the plurality of MLPEs 200 and transmit the collected information to the server 300 , and the server 300 may monitor power generation status of the plurality of photovoltaic panels 10 using the power generation information of the plurality of photovoltaic panels 10 .

[0057] Here, information transmission and reception between the main controller 100 and the server 300 can be performed in a wired manner or a wireless manner.

[0058] The main controller 100 may control the plurality of MLPEs 200 according to the power generation status of the photovoltaic panel 10 .

[0059] To monitor the power generation status of the plurality of photovoltaic panels 10, the main controller 100 may send command data to the plurality of MLPEs 200, and the plurality of MLPEs 200 may send response data to the main controller 100 in response to the command data, the response data including power generation information of the photovoltaic panels 10. In addition, the main controller 100 collects the power generation information of the plurality of photovoltaic panels 10 and transmits the collected information to the server 300.

[0060] In addition, according to an embodiment of the present disclosure, the inverter 400 is a component installed in a power conversion system (PCS) and configured to perform power conversion to supply the power generated by the photovoltaic panel 10 to a load or a grid. Figure 1AAs shown, the inverter 400 may include a main controller 100, or as shown in FIG. Figure 1B As shown, the inverter 400 can be set separately from the main controller 100. In the following description, for the convenience of description, Figure 1A The illustrated embodiment in which the inverter 100 includes the main controller 400 is described as a reference, and the operation of the inverter 400 may be understood as the operation of the main controller 100 .

[0061] Meanwhile, the accumulated power generation data is required to quantitatively determine the power generation of the photovoltaic panel 10 .

[0062] To this end, the MLPE 200 sequentially stores the accumulated power generation data of the photovoltaic panel 10 in a buffer at preset time intervals, and periodically transmits the data stored in the buffer to the main controller 100 in response to a request from the main controller 100 .

[0063] Here, if a communication failure occurs between the MLPE 200 and the main controller 100 and no communication occurs for a certain period of time, the main controller 100 may be unable to receive some data. Furthermore, due to system failures, the same data may be redundantly transmitted to the main controller 100. In this case, the reliability of the data may be reduced. Furthermore, the reliability of the data may vary depending on the communication environment, which may result in an inability to accurately monitor the cumulative power generation of the photovoltaic panel 10.

[0064] Figure 2 is a detailed block diagram of an MLPE and a main controller according to an embodiment of the present disclosure.

[0065] refer to Figure 2 , the MLPE 200 may include a communication unit 210, a processor 220, and a first buffer 230, and the main controller 100 may include a communication unit 110, a processor 120, and a second buffer 130. The main controller 100 may be implemented as a device configured to update the accumulated power generation data of the MLPE 200.

[0066] Figure 3 is a flowchart illustrating a method of operating a photovoltaic power generation system according to an embodiment of the present disclosure.

[0067] refer to Figure 2 and Figure 3 , the MLPE 200 generates power generation data ( 301 ) by accumulating power generation of the photovoltaic panel at each first set time.

[0068] Furthermore, the MLPE 200 sequentially stores the power generation amount data in the first buffer ( 302 ).

[0069] Furthermore, the main controller 100 acquires N pieces of power generation amount data stored in the first buffer as a first data set at every second set time ( 303 ).

[0070] Furthermore, the main controller 100 compares the second data set, which is a set of M data previously stored in the second buffer, with the most recently acquired first data set ( 304 ).

[0071] Furthermore, the main controller 100 updates the second buffer based on the first data set ( 305 ).

[0072] The following will describe in more detail Figure 2 and Figure 3 The present invention provides a main controller and an inverter for a photovoltaic power generation system, and a method for operating the photovoltaic power generation system.

[0073] Figure 4 A method in which MLPE stores data in a first buffer according to an embodiment of the present disclosure is shown.

[0074] refer to Figure 4 The processor 220 of the MLPE 200 sequentially stores N (where N is a natural number greater than or equal to 2) power generation data in the first buffer 230, each power generation data being obtained by accumulating the power generation of the photovoltaic panel 10 at each first set time T.

[0075] Here, the first buffer 230 has a size capable of storing up to N pieces of power generation amount data.

[0076] Specifically, the first buffer 230 is configured with first to Nth buffer spaces, and data can be stored in each buffer space. In addition, N data are sequentially stored from the first buffer space to the Nth buffer space according to the order of input data.

[0077] For example, in the initial operation of the MLPE 200, no data is stored in each buffer space of the first buffer 230. Thereafter, when the MLPE 200 is running and a first set time T has elapsed, data 1 is stored in the first buffer space. The data 1 is obtained by accumulating the power generation amount of the photovoltaic panel 10 during the first set time T. The above process is repeated until data N is stored in the first buffer 230. Therefore, data 1 to data N are sequentially stored in the first to Nth buffer spaces of the first buffer 230.

[0078] Here, the storage period of N data may be defined as the product of the first set time T and the size N of the first buffer 230 .

[0079] From the time when the N data are stored in the first buffer 230 until the storage period and the first set time T have passed again, the N data are stored in the first buffer 230 and then deleted from the first buffer 230. That is, after the N data are stored in the first buffer 230, the N data are deleted from the first buffer 230 in the order in which the N data were stored.

[0080] Specifically, refer to Figure 3 After data 1 to data N are sequentially stored in the first to Nth buffer spaces of the first buffer 230, when a first set time T elapses, new data 1 needs to be stored in the first buffer 230. However, since the first buffer 230 can only store N data at most, the previously stored data 1, which is the first of the N data, is deleted and the new data is stored. This process is repeated each time new data is stored.

[0081] Here, data 1 may be deleted by overwriting data 1 to data (N-1) stored from the first cache space to the (N-1)th cache space with data 2 to data N stored in the second cache space to the Nth cache space, respectively.

[0082] Furthermore, new data may be stored in the Nth cache space by overwriting data N stored in the Nth cache space with the new data.

[0083] Therefore, data is sequentially stored in the first to N-th buffer spaces of the first buffer 230 .

[0084] The processor 120 of the main controller 100 requests N power generation data as a first set from the processor 220 of the MLPE 200 at every second set time. Here, the communication unit 110 of the main controller 100 may transmit command data for requesting the first set of data to the communication unit 210 of the MLPE 200. Furthermore, the second set time may be shorter than the period (TxN) during which the MLPE 200 stores N data.

[0085] Regardless of whether the main controller 100 issues a data request, the processor 220 of the MLPE 200 sequentially stores N data in the first buffer 230 at each first set time T. Each of the N data is obtained by accumulating the power generation of the photovoltaic panel 10 .

[0086] In response to the data request, the processor 220 of the MLPE 200 transmits the N power generation amount data stored in the first buffer 230 as a first data set to the communication unit 110 of the main controller 100 through the communication unit 210 .

[0087] The communication unit 110 of the main controller 100 receives the first data set from the MLPE 200 , and the processor 120 of the main controller 100 selects new data based on the received first data set and stores the selected new data in the second buffer 130 .

[0088] Such a process of requesting and receiving data is sequentially performed for each of the plurality of MLPEs 200 .

[0089] The processor 120 of the main controller 100 compares the second data set previously stored in the second buffer 130 with the first data set most recently received from the MLPE 200, and updates the data in the second buffer. In this case, the size of the first buffer is capable of storing a maximum of N power generation data, and the size of the second buffer is capable of storing a maximum of M power generation data, where M may be greater than or equal to N.

[0090] Here, because the second set time is shorter than the period (TxN) during which the main controller 100 receives data from the MLPE 200 and the period (TxN) is a period during which the MLPE 200 stores N data, the first data set may include data that overlaps with the second data set. That is, the first data set may include data previously stored in the second buffer 130 and new data.

[0091] Therefore, the processor 120 of the main controller 100 determines whether the latest data recently stored in the second data set is included in the first data set. Here, when the latest data exists in the first data set, the processor 120 stores new data stored after the latest data in the second buffer 130.

[0092] Specifically, the processor 120 can search for the latest non-zero data (hereinafter referred to as "second cache latest data") in the second data set in an order opposite to the storage order of the second cache 130, and based on the existence of the second cache latest data, the latest data can be searched in the first data set according to the storage order in the first cache 230, and based on the existence of the latest data in the first cache 230, at least one new data stored after the latest data can be stored in the second cache 130.

[0093] That is, the processor 120 searches the second buffer for the second-buffer latest data in reverse order, and when the second-buffer latest data exists in the second data set, the processor 120 searches the first data set for the second-buffer latest data in the order in which the data is stored. When the second-buffer latest data exists in the first data set, at least one new data stored after the second-buffer latest data may be stored in the second buffer.

[0094] When the latest data in the second buffer does not exist in the first data set, the processor 120 stores the entire first data set in the second buffer. Alternatively, when the latest data in the second buffer does not exist in the second data set, the entire first data set may be stored in the second buffer.

[0095] Figure 5A and Figure 5B An example of updating the second buffer according to an embodiment of the present disclosure is shown.

[0096] According to an embodiment of the present disclosure, Figure 5A Assume the case where N is equal to M (ie, the number of cache spaces in the second cache is the same as the number of cache spaces in the first cache), and Figure 5B Assume that M is greater than N (ie, the number of cache spaces in the second cache is greater than the number of cache spaces in the first cache).

[0097] For example, reference Figure 5A The second buffer 130 of the main controller 100 sequentially stores data 1 to data N as a second data set of N data. In addition, the main controller 100 receives data 3 to data N, new data 1 and new data 2 from the MLPE 200 as a first data set of N data.

[0098] Here, since the first data set includes data N, the first data set may be considered to be received within a period (TxN) in which the MLPE 200 stores N data starting from the time point when the second data set is received.

[0099] The processor 120 of the main controller 100 determines whether there is the latest non-zero data (hereinafter referred to as "second buffer latest data") in the second data set in the reverse order of the storage order of the second buffer 130. Here, when the accumulated data N (latest data) exists in the second data set, the processor 120 searches for the accumulated data N in the first data set stored in the first buffer 230 in the storage order. Here, when the accumulated data N exists in the first buffer 230, the new data 1 and the new data 2 stored after the accumulated data N in the first data set of N data are stored in the second buffer 130.

[0100] The second buffer 130 of the main controller 100 may have a size capable of storing up to N data, but is not limited thereto and may have a larger size. The number of second buffers 130 may be provided in accordance with the number of MLPEs 200 .

[0101] Specifically, the second buffer 130 is configured with first to Nth buffer spaces, and can store separate power generation data in each buffer space. In addition, the first data set of N data is sequentially stored in the first to Nth buffer spaces according to the order of input data.

[0102] After the first data set is stored in the second buffer 130 , the first data sets are deleted from the second buffer 130 in sequence according to the storage order of the first data sets of the N data.

[0103] For example, reference Figure 4 , when data 1 to data N are received from the MLPE 200 as a first data set, the second buffer 130 stores data 1 to data N in the first to Nth buffer spaces in sequence.

[0104] In addition, new data 1 and new data 2 (stored in the first data set after data N) need to be stored in the second buffer 130. However, since the second buffer 130 can only store N data at most, data 1 and data 2 stored first among the previously stored N data are deleted and replaced with new data 1 and new data 2. This process is repeated every time new data is stored.

[0105] Here, accumulated data 1 and accumulated data 2 may be deleted by overwriting data 1 to data (N-2) stored in 1 to (N-2)th cache spaces with data 3 to data N stored in the 3rd to Nth cache spaces, respectively.

[0106] Furthermore, new data 1 and new data 2 may be stored in the (N-1)th cache space and the Nth cache space by overwriting data N-1 and data N stored in the (N-1)th cache space and the Nth cache space, respectively.

[0107] Therefore, the power generation amount data in the first data set are sequentially stored in the first to Nth buffer spaces of the second buffer 130 .

[0108] As mentioned above, Figure 5B Assume that M is greater than N (ie, the amount of buffer space in the second buffer is greater than the amount of buffer space in the first buffer). Figure 5A ,exist Figure 5B In an embodiment, the previous accumulated data 1 to accumulated data (MN) can be pre-stored in the first to (MN)th cache spaces of the second cache, and the accumulated data 1 to accumulated data N can be stored in the (M-N+1)th to Mth cache spaces.

[0109] In this case, if Figure 5AAs shown, when a first data set including new data 1 and new data 2 is obtained, the previous accumulated data 3 to accumulated data (MN) are stored in the first to (MN-2)th cache spaces, the accumulated data 1 to accumulated data N are stored in the (MN-1)th to (M-2)th cache spaces, and the new accumulated data 1 and the new accumulated data 2 are stored in the (M-1)th and Mth cache spaces, respectively.

[0110] That is, according to an embodiment, when there is at least one new data (stored after the latest data in the second buffer) in the first data set and the number of the at least one new data is Nnew, the processor 120 may sequentially store the Nnew data in the (M-Nnew+1)th to Mth spaces in the storage space of the second buffer. To this end, the processor 120 may delete the data previously stored in the first to (M-Nnew)th cache spaces of the second buffer, and newly store the data previously stored in the (M-Nnew+1)th to Mth cache spaces in the first to (M-Nnew)th spaces.

[0111] As described above, according to the present disclosure, even if a communication failure occurs between the MLPE 200 and the main controller 100 and no communication is performed for a certain period of time, as long as at least one communication is performed within the period (TxN) (in which the MLPE 200 stores N data from the time of receiving the second data set of N data), the main controller 100 can prevent data loss without the need for a separate communication integrity check. Furthermore, duplicate data storage due to system failures can be prevented. This improves data reliability, enabling accurate monitoring of the cumulative power generation of the photovoltaic panel 10.

[0112] The processor 120 of the main controller 100 may compare the latest data stored in the second buffer 130 with the first data set in the order in which the first data set of the N data is stored.

[0113] When the latest data does not exist in the first data set, the processor 120 of the main controller 100 deletes the second data set of the N data and stores the first data set of the N data in the second buffer 130 .

[0114] Figure 6A and Figure 6B An example of updating the second buffer according to another embodiment of the present disclosure is shown.

[0115] According to an embodiment of the present disclosure, Figure 6A Assume the case where N is equal to M (ie, the number of cache spaces in the second cache is the same as the number of cache spaces in the first cache), and Figure 6BAssume that M is greater than N (ie, the number of cache spaces in the second cache is greater than the number of cache spaces in the first cache).

[0116] For example, reference Figure 6A , the second buffer 130 of the main controller 100 sequentially stores data 1 to data N as a second data set. In addition, the main controller 100 receives new data 1 to data N from the MLPE 200 as a first data set.

[0117] Here, since the first data set does not include data N (which is the latest non-zero data in the second data set (the latest data in the second buffer)), the first data set can be considered to be received after the period (TxN), in which the MLPE 200 stores N data from the time point of receiving the second data set.

[0118] The processor 120 of the main controller 100 searches whether the latest non-zero data in the second data set exists in the first data set of N data in the reverse order of the storage order of the second buffer 130. Here, conversely, if the latest non-zero data exists in the second data set, the processor 120 searches whether the latest data exists in the first data set according to the storage order of the second buffer 130, and if the data N (the latest data in the first data set) does not exist, the processor 120 stores the new data 1 to data N in the second buffer 130.

[0119] Here, new data 1 to data N may be stored by overwriting data 1 to data N stored in the first to Nth cache spaces, respectively.

[0120] As mentioned above, Figure 6B Assume that M is greater than N (ie, the amount of buffer space in the second buffer is greater than the amount of buffer space in the first buffer). Figure 6A ,exist Figure 6B In an embodiment, the previous accumulated data 1 to accumulated data (MN) can be pre-stored in the first to (MN)th cache spaces of the second cache, and the accumulated data 1 to accumulated data N can be stored in the (M-N+1)th to Mth cache spaces.

[0121] In this case, if Figure 6A As shown, when a first data set including new data 1 to new data N is obtained, the previous accumulated data (N+1) to accumulated data (MN) can be stored in the 1st to (M-2N)th cache spaces, the accumulated data 1 to accumulated data N can be stored in the (M-2N+1)th to (MN)th cache spaces, and the new accumulated data 1 to new accumulated data N can be stored in the (M-N+1)th to Mth cache spaces respectively.

[0122] That is, according to an embodiment, when the latest data of the second buffer does not exist in the first data set, the processor 120 may sequentially store the entire first data set in the (M-N+1)th to Mth cache spaces of the second buffer.

[0123] Therefore, new data 1 to new data N are sequentially stored in the first to Nth buffer spaces of the second buffer 130 .

[0124] The processor 120 of the main controller 100 searches whether there is the latest non-zero data in the second data set of N data stored in the second buffer 130 in the reverse storage order, and when the search result is that no data is stored in the second buffer 130 (that is, when all data of the second data set stored in the second buffer 130 are zero), the processor stores all the first data sets of N data received from the MLPE 200 in the second buffer 130.

[0125] Figure 7 An example of updating the second buffer according to another embodiment of the present disclosure is shown.

[0126] For example, reference Figure 7 , the second buffer 130 of the main controller 100 does not store data in the first to M-th buffer spaces. In addition, the main controller 100 receives data 3 to data N, new data 1, and new data 2 from the MLPE 200.

[0127] Here, since no data is stored in the second buffer 130 , it may be regarded as an initial operation state of the MLPE 200 .

[0128] As described above, since no data is stored in the second buffer 130 , the processor 120 sequentially stores data 3 to data N, new data 1 and new data 2 forming the first data set in the first to Nth buffer spaces of the second buffer 130 .

[0129] That is, when the second data set does not contain the latest data in the second buffer, the processor 120 may sequentially store the entire first data set in the (M-N+1)th to Mth cache spaces of the second buffer.

[0130] Figure 8 is a flowchart illustrating a method of updating cumulative power generation data of an MLPE according to an embodiment of the present disclosure.

[0131] refer to Figure 8 , the MLPE 200 stores the power generation data in the first buffer in sequence (801).

[0132] Then, the main controller 100 acquires N pieces of power generation amount data stored in the first buffer as a first data set ( 802 ).

[0133] Then, the main controller 100 compares the second data set, which includes M data previously stored in the second buffer, with the most recently acquired first data set ( 803 ).

[0134] Then, when searching the second data set in reverse order, the main controller 100 determines whether the second buffer latest data exists (804), and when the second buffer latest data exists, the main controller 100 stores the entire first data set in the second buffer (805).

[0135] Alternatively, when the second buffer latest data does not exist, it is determined whether the first data set includes the second buffer latest data (806), and when the second buffer latest data exists, the entire first data set is stored in the second buffer (805).

[0136] In addition, when the second buffer latest data does not exist in the first data set, the memory stores at least one new data in the second buffer, the at least one new data being stored in the first data set after the second buffer latest data (807).

[0137] Figure 9 is a detailed flowchart illustrating a method of updating the cumulative power generation amount data of the MLPE according to an embodiment of the present disclosure.

[0138] refer to Figure 9 In the method for updating the accumulated power generation data of the MLPE according to an embodiment of the present disclosure, first, the MLPE 200 sequentially stores N data in the first buffer 230, each data being obtained by accumulating the power generation of the photovoltaic panel 10 at each first set time (S10).

[0139] Then, the main controller 100 requests a second data set of N data from the MLPE 200 , receives the second data set of N data from the MLPE 200 , and stores the second data set of N data in the second buffer 130 ( S20 ).

[0140] Then, it is determined whether a second set time has passed ( S30 ), and when the second set time has passed, the main controller 100 requests a first data set of N data from the MLPE 200 ( S40 ), and receives the first data set of N data from the MLPE 200 ( S50 ).

[0141] Then, the main controller 100 compares the second data set of N data previously stored in the second buffer 130 with the first data set of N data currently received from the MLPE 200 and updates the second data set of N data.

[0142] Here, the operation of updating the second data set of N data includes searching whether there is the latest non-zero data in the second data set of N data in the reverse order of the storage order of the second buffer 130 ( S60 ).

[0143] When the latest data does not exist in the second buffer 130 , the first data set of N data is completely stored in the second buffer 130 based on the absence of the latest data in the second buffer 130 ( S72 ).

[0144] Then, when the latest data exists in the second data set of the N data ( S70 ), the first data set is searched in the first buffer 230 in the order of storage based on the existence of the latest data in the second buffer 130 ( S71 ).

[0145] Next, when the latest data exists in the first data set of N data (S80), based on the existence of the latest data in the first buffer 230, at least one new data is stored in the second buffer 130, and the at least one new data is stored in the first data set of N data after the latest data (S81).

[0146] On the other hand, when the latest data does not exist in the first data set of N data, the second data set of N data in the second buffer 130 is deleted and the first data set of N data is stored in the second buffer 130 (S82).

[0147] As described above, in the method for updating the accumulated power generation data of the MLPE according to an embodiment of the present disclosure, even if a communication failure occurs between the MLPE 200 and the main controller 100 and no communication occurs for a certain period of time, as long as at least one communication is performed within the period (TxN) (the time point at which the MLPE 200 receives the second data set of N data from the main controller 100 in this period (TxN) and stores N data), data loss can be prevented. In addition, duplicate data storage due to system failure can be prevented. As a result, the reliability of the data can be improved, thereby accurately monitoring the accumulated power generation of the photovoltaic panel 10.

[0148] While specific embodiments are described in the detailed description of the present disclosure, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the appended claims, but also by the scope of the claims and their equivalents.

[0149] Description of Reference Numerals Representing Main Elements of the Drawings

[0150] 100: Main controller

[0151] 200:MLPE

[0152] 300: Server.

Claims

1. A method for operating a photovoltaic power generation system, the method comprising: generating power generation data obtained by accumulating power generation of the photovoltaic panel at each first set time; storing the power generation data in a first buffer in sequence; At each second set time, acquiring N power generation data stored in the first buffer as a first data set, where N is a natural number greater than or equal to 2; Comparing a second data set with a most recently acquired first data set, wherein the second data set is a set of M data previously stored in the second buffer, where M is a natural number greater than or equal to 2; and In response to the comparison, the second buffer is updated based on the first data set.

2. The method according to claim 1, wherein The comparison includes: Searching the second data set for the latest non-zero data in an order opposite to the storage order of the second buffer, hereinafter the order opposite to the storage order of the second buffer is referred to as reverse order, and the latest non-zero data is referred to as the second buffer latest data; and When the latest data in the second buffer exists, the first data set is searched according to the storage order of the first buffer to see whether the latest data in the second buffer exists.

3. The method according to claim 2, wherein: In the updating, when the latest data of the second buffer exists in the first data set, at least one new data stored after the latest data of the second buffer is stored in the second buffer.

4. The method according to claim 3, wherein: In said update, When the number of the at least one new data stored in the first data set after the latest data in the second buffer is Nnew, The Nnew data are sequentially stored in the M-Nnew+1th to Mth spaces in the storage space of the second buffer.

5. The method according to claim 4, wherein In said update, deleting the data previously stored in the first to M-Nnewth cache spaces of the second cache, and The data stored in the M-Nnew+1th to M-th cache spaces are newly stored in the first to M-Nnew+1th spaces.

6. The method according to claim 2, wherein: In the updating, when the latest data in the second buffer does not exist in the first data set, the first data set is completely stored in the second buffer.

7. The method according to claim 6, wherein: In the updating, the first data set is completely stored in sequence in the M-N+1th to Mth cache spaces of the second cache.

8. The method according to claim 2, wherein: In the updating, when the second data set does not contain the latest data of the second buffer, the first data set is completely stored in the second buffer.

9. The method according to claim 8, wherein In the updating, the first data set is completely stored in sequence in the M-N+1th to Mth cache spaces of the second cache.

10. The method according to claim 1, wherein The first buffer has a size configured to store up to N pieces of the power generation amount data, and The second buffer has a size configured to store up to M pieces of the power generation amount data, Here, N is a number less than or equal to M.

11. A main controller of a photovoltaic power generation system, wherein: The main controller is configured to: Requesting a first data set stored in a first buffer of a module-level power electronic device MLPE of the photovoltaic power generation system from the MLPE; Obtaining the first data set from the MLPE; comparing a second data set with the first data set most recently received from the MLPE, the second data set being a set of M data previously stored in a second buffer of the master controller, where M is a natural number greater than or equal to 2; as well as In response to the comparison, the second buffer is updated based on the first data set.

12. The main controller according to claim 11, wherein: The first data set is a set of N data, each of the N data is obtained by accumulating the power generation of the photovoltaic panel at each first set time, wherein N is a natural number greater than or equal to 2, and The main controller is further configured to request the first data set from the MLPE at every second set time.

13. The main controller according to claim 11, wherein: The main controller is further configured to: search the second data for the latest non-zero data in an order opposite to the storage order of the second buffer, hereinafter the order opposite to the storage order of the second buffer is referred to as reverse order, and the latest non-zero data is referred to as the second-buffer latest data; based on the existence of the second-buffer latest data, search the first data set for the latest second-buffer data in the storage order of the first buffer; And based on the existence of the latest data of the second buffer in the first data set, at least one new data stored after the latest data of the second buffer is stored in the second buffer.

14. The main controller according to claim 11, wherein: The main controller is further configured to: search the second data set in reverse order for the presence of the second buffer's latest data; and based on the absence of the latest data in the second buffer, completely store the first data set in the second buffer.

15. The main controller according to claim 11, wherein: The main controller is further configured to: search the second data set in reverse order for the presence of the second buffer's latest data; and based on the presence of the second buffer's latest data, search the first data set in the storage order of the first buffer for the presence of the second buffer's latest data; And based on the absence of the second buffer data in the first data set, completely storing the first data set of the N data in the second buffer.

16. The main controller according to claim 11, wherein: The first buffer has a size configured to store up to N power generation amount data, and The second buffer has a size configured to store up to M power generation amount data, Here, N is a number less than or equal to M.

17. The main controller according to claim 11, wherein: The MLPE is configured to, after storing the N power generation amount data in the first buffer, sequentially delete the power generation amount data according to the storage order of the first buffer, and sequentially store new data.

18. The main controller according to claim 11, wherein: The main controller is further configured to, after storing the second data set including M power generation data in the second buffer, sequentially delete the power generation data according to the storage order of the second buffer and sequentially store new data.

19. An inverter comprising a main controller of a photovoltaic power generation system, wherein: The inverter is configured as follows: Requesting a first data set stored in a first buffer of a module-level power electronic device MLPE of the photovoltaic power generation system; Obtaining the first data set from the MLPE; comparing a second data set with the first data set most recently received from the MLPE, the second data set being a set of M data previously stored in a second buffer of the master controller, where M is a natural number greater than or equal to 2; as well as In response to the comparison, the second buffer is updated based on the first data set.

20. The inverter according to claim 19, wherein: The first data set is a set of N data, each of the N data is obtained by accumulating the power generation of the photovoltaic panel at each first set time, wherein N is a natural number greater than or equal to 2, and The main controller is configured to request the first data set from the MLPE at every second set time.

Images