METHOD FOR SETTING A POWER CLASS OF AN INVERTER AND INVERTER

Description

[0001] The invention relates to a method for setting a power class of an inverter and to an inverter.

[0002] Inverters are power electronic devices designed to convert direct current to alternating current and vice versa. Inverters of a given type are generally available in different power classes. Inverters of different power classes are designed for different power outputs. This simplifies the selection of an inverter with the right power for a specific application.

[0003] Inverters can, for example, convert the direct current from solar modules into alternating current for feeding into the power grid. The inverter, also called a PV inverter, is therefore part of a photovoltaic (PV) system. A PV system can comprise multiple PV generators. By providing different power classes, a customer request for an inverter with the appropriate power for different PV systems and / or PV generators can be met.

[0004] However, to simplify production organization and component procurement, the smallest possible number of different inverter variants of a particular type may be desired. Customers' desire for the widest possible selection of power classes and efficient device production may therefore be in conflict. This problem can be solved, for example, by determining device power as late as possible in production or, if necessary, later during installation or commissioning. Inverters of a given type can be largely or completely identical in terms of technology and differ in their power settings, e.g., via software, and the nameplate corresponding to the set power. Setting the power and attaching the nameplate can be performed at the end of production, so that most production steps can be identical for all power classes.

[0005] For storage purposes at the manufacturer, wholesaler, and / or installer, devices can still be available in different power classes. The advantages of the technical similarity of the power classes are thus primarily utilized in production. This is because the device power is determined at the end of production. Delaying the power setting until the time of installation would further simplify logistics for the wholesaler, installer, and manufacturer.

[0006] Safety standards for PV inverters require a nameplate to indicate the power rating and related parameters, such as the maximum grid current. The device's power rating is essential for the design of the cables and fuses in the system and is also the basis for the grid operator's approval for feeding the power into the grid. Therefore, it is necessary to ensure that the power rating on the nameplate matches the actual power rating of the device, even if the power rating is determined at the time of installation. Protection against misuse is also required.

[0007] DE 10 2015 101 684 A1 proposes the use of RFID labels as part of a variable nameplate. The power rating is encoded in the RFID label and corresponds to the printed information. This label is affixed during installation. The inverter contains an RFID reader that reads the data from the RFID label each time the inverter is started and adjusts the output. This ensures that the power rating displayed on the nameplate matches the actual power rating of the device.

[0008] A disadvantage of this method is the technical complexity of the RFID reader integrated into the inverter. Furthermore, the use of this technology limits the choice of housing material. RFID is radio-based, and the housing must not shield the RFID communication frequency.

[0009] Document EP 3 438 009 A1 discloses a method in which an already packaged inverter can be commissioned by enclosing a type plate and a device for configuring the inverter after installation in the packaging.

[0010] Furthermore, document DE 10 2014 226 620 A1 describes an electro-hydraulic drive in which an attached type identifier is read via a smartphone, and a parameter set uniquely assigned to the type identifier is transmitted to the drive for operation. The goal is to prevent incorrect parameter transmission and the resulting damage.

[0011] The invention is based on the object of efficiently handling the setting of the power class of inverters.

[0012] The object is achieved by a method having the features of patent claim 1 and an inverter having the features of patent claim 14. Preferred embodiments are specified in the dependent claims.

[0013] An inverter has a device nameplate that contains device-specific information about the inverter, independent of the selected power class. The inverter also has a class nameplate selected from a number of power class-specific class names, each assigned to a power class of a plurality of power classes. The class nameplate contains information about the power class assigned to the inverter. The assigned power class is the power class to which the inverter should be set.

[0014] The procedure for setting the inverter power class includes the following steps: Visually capturing the device type plate and the class plate and reading out the device-specific information and the information about the assigned power class from the image-captured data, i.e. from the captured image or images, transmitting a setting sequence to the inverter, wherein the setting sequence contains the information about the assigned power class, setting the power class of the inverter based on the setting sequence after authenticating the read-out information.

[0015] Preferably, the device type plate and the class plate are captured together, i.e., using an optical image. The image capture can be performed, for example, using a camera on a mobile device, such as a smartphone.

[0016] In one embodiment, the inverter has a controller that controls power electronic switches, via which the input-side DC voltage can be converted into AC voltage or vice versa. The controller is preferably configured to set the power class of the inverter after receiving the setting sequence, for example, by software-based configuration of the program code executable on the controller's computing device.

[0017] The setting sequence can be transmitted to the inverter acoustically, mechanically, optically, directly electrically, or by other means, especially wirelessly. Examples of possible transmission methods include: RFID, a camera in the inverter, a barcode scanner in the inverter, a microphone, a shock sensor, a photodiode, Bluetooth, Wi-Fi, Ethernet, RS485, a USB stick, a memory card, etc. The setting sequence is preferably transmitted to the inverter after checking whether a combination of device-specific information and information about the assigned power class is a permissible combination.

[0018] The invention makes it possible to set the power class of an inverter, selected from a plurality of power classes in which the inverter can be operated, during installation, in particular to set it permanently in such a way that it is ensured that the set power class conforms to the standards and corresponds clearly to the information on the labeling affixed to the inverter. This is done using a two-part plate for the inverter. The two-part plate comprises a device type plate as one part and a class plate as the other. The device type plate is preferably permanently affixed during production. It contains all non-power-variable information about the inverter, preferably also in human-readable form, e.g., plain text. In addition, the device type plate contains a visually readable code, preferably a visually computer-readable code, e.g.,QR code or barcode that identifies the device. The device's identification can include, for example, the serial number and / or the type designation.

[0019] The class label contains variable performance information about the inverter and is preferably included in several versions with the inverter. The information on the class label is readable visually, e.g., in the form of a QR code, and includes information about the inverter's performance class. The variable performance information on the class label is preferably also available in a human-readable format, e.g., in plain text.

[0020] The class label is preferably attached to the inverter during installation. In one embodiment, the selection of the class label from the plurality of class labels and the attachment, in particular permanent attachment, of the class label to the inverter can take place before the image readout. These steps of selection and attachment can be performed, for example, by the installer during installation of the inverter and before its commissioning. The attachment of the class label can be done, for example, by gluing it on. Permanent attachment means that the label cannot be removed without causing damage.

[0021] This procedure ensures that the inverter bearing a label indicating a specific power rating actually meets that rating. The proposed solution is more reliable than adjustment by the installer because it better ensures that the rating shown on the rating plate matches the actual rating. This avoids the risk of the installer applying the wrong label and thus accidentally producing a device that is not approved by the standards. Furthermore, it can ensure that a PV system, including the inverter, matches the specifications with which it was registered with the grid operator.

[0022] According to the invention, the information read out via images is authenticated before the inverter's power class is set. Authentication in this context means verifying the correct origin and / or correctness of the content. Authentication can be verified, for example, using cryptographic methods, e.g., via the app, by verifying a signature of the information read out via images. For example, the setting sequence can be generated only after authentication. Authentication can optionally include querying a database via a remote data connection, where the image-captured information can be verified, e.g., using a database query.In particular, the database may contain a list of permissible combinations of device-specific information and information on the assigned performance class, so that it can be ensured that an impermissible combination of nameplate and class plate is detected, in which case no setting sequence is generated.

[0023] The setting sequence preferably includes additional security features that cannot be determined, or cannot be directly determined, from the device nameplate and the class label. The inverter can preferably check these security features. These security features can, for example, serve for authentication and include encryption and / or a signature. This further increases security.

[0024] In the event of successful authentication, the setting sequence can then be transmitted to the inverter, comprising an authentication section, an inverter identification section, and a power class section. The inverter checks the authentication section and the inverter identification section before a power class contained in the power class section is set, in particular permanently set. The authentication section can, in particular, contain a signature that is checked by the inverter.

[0025] According to the invention, the setting sequence is generated from the device-specific information and the information on the assigned power class before being transmitted to the inverter. The generation can, for example, take place on the same device as the image capture of the device type plate and the class plate. Alternatively or additionally, the generation of the setting sequence can take place in a central unit that communicates with the device via a remote data connection, e.g. via the Internet and / or mobile communications. A central unit can, for example, be a data center operated by the manufacturer of the inverter and preferably has a database and is located, for example, in the cloud. In a further development, the mobile device, e.g. smartphone, can transmit the data, and the central unit can, for example,An encrypted and / or signed device-specific setting sequence can be generated based on knowledge of a non-public secret. Preferably, access to the control center's facilities is only possible after previously established identity and authorization. Alternatively or additionally, the encrypted and / or signed setting sequence can be generated directly on the mobile device.

[0026] In one embodiment, the inverter has structures to prevent tampering with the attached class plate. This can be done, for example, by mechanically attaching the class plate to the inverter in such a way that removal would result in visible damage. This makes tampering detectable. Such mechanical attachment can be achieved, for example, using non-removable locking hooks. It can also be achieved by already having information on all power classes on the device type plate and removing the non-applicable parts, for example by breaking them off at predetermined breaking points. It can also be achieved by already having information on all power classes on the device type plate and covering up the non-applicable parts, for example by using cover plates with non-removable locking hooks.

[0027] It is advantageous to capture images on a mobile device equipped with cryptographic functions. This can be achieved, for example, by using a smartphone with an app and cryptography. This can prevent misuse in countries where, for example, the requirements for inverters and the costs for grid access increase with the inverter output. It can also prevent unauthorized increases in output. In particular, this should prevent unauthorized increases in output after the system has been accepted by the grid operator.

[0028] In one embodiment, after installing the inverter and attaching the class plate, the installer scans the codes on the device type plate and the class plate with the app using their smartphone's camera. The app checks that both parts of the type plate are present and are in the correct position relative to each other. In one embodiment, the app can then use the information about the inverter type on the device type plate and the information about the power class on the class plate to create the encrypted, secure setting sequence for power activation for the inverter, which can be checked for validity by the inverter, and sends this to the inverter. The inverter checks this setting sequence and, if the check is successful, sets the appropriate power. Preferably, the power is set permanently, which means that it can only be changed by the manufacturer and not by the user or system operator.This ensures that the power on the label corresponds to the actual power of the inverter.

[0029] In a preferred embodiment, the inverter reports the successful power setting back to the sender of the setting sequence. It can also report back that a power setting was not successful, and if necessary, the reason for the failure can also be communicated.

[0030] In a preferred embodiment of the invention, the image capture and transmission of the setting sequence are carried out using the same device, in particular the mobile device, preferably a smartphone. This ensures ease of use.

[0031] One embodiment may include checking the status of the tamper-evident structures in the captured image. For example, the mobile device may detect the tamper-evident structures of the class label attached to the inverter. For example, the app may be configured to detect an incorrectly attached class label that was protected from tampering, for example, by the aforementioned mechanical measures on the inverter. For example, the setting sequence may not be generated if checking the status of the structures in the captured image reveals that tampering has occurred.

[0032] In one embodiment, authentication may include capturing and verifying information about the person performing the image capture. For example, information about the person performing the image capture may be captured and verified to determine whether the person is authorized. Information about the person performing the image capture may, for example, be an image capture of the person or, for example, the reading of an authorization card. For example, the generation of the setting sequence may be linked to this and only occur if the person has been identified as an authorized person.

[0033] In one embodiment, authentication can include checking whether the prerequisites for setting the inverter's power class are met. The generation of the setting sequence would advantageously only occur after the validation of a contractual relationship. Such validation could be performed by querying a remote database and could include, for example, whether payment has been made, whether a valid framework agreement exists, authorization for activation has been obtained, etc. For validation purposes, this information could be linked to information about the requester, e.g., the identity of the PV system, the role of the requester and / or their identity, or similar. In particular, it can also be checked whether the power class to be set corresponds to the one ordered and thus paid for. When the setting sequence is generated in the central unit with the database, a check can be carried out to determine whether payment for the set power class has been made.If the price for an inverter depends on the power output and the payment for the set power output, this can be checked before its release and before the setting code is generated. A separate code can be used for this purpose, which is transmitted from the control center to the inverter, e.g., via remote data transmission. All of this can be checked as part of the admissibility check for the combination of device-specific information and information about the assigned power class. In a variant of the process, a payment process can also be triggered automatically when the setting sequence is generated, with the price corresponding to the power class contained in the setting sequence.

[0034] This process allows for cost-effective and reliable power adjustment after production and during installation of the inverter, simplifying logistics.

[0035] In a further development, to further increase safety, it can be provided that the inverter does not output any electrical power without the power class being set.

[0036] In a further embodiment, after setting the power class, it can advantageously not be subsequently changed by the installer, but only by the manufacturer of the inverter, for example.

[0037] In one embodiment, the setting sequence can be transmitted via a transmission path independent of a device used for image capture, e.g., from the control center to the inverter via remote data communication.

[0038] In a preferred embodiment, the setting sequence is encrypted before being transmitted to the inverter to ensure confidentiality and / or signed to ensure authenticity. The inverter thereby authenticates the transmitted setting sequence. This ensures that the setting sequence is only accepted by the designated inverter for setting a power class.

[0039] An inverter with an adjustable power class has a device nameplate containing device-specific information about the inverter that is independent of the power class. The inverter further has a class nameplate that is selected from a plurality of power-class-specific class names, each assigned to a power class of the plurality of power classes, and that contains information about the assigned power class. Preferably, the device nameplate and the class nameplate are arranged on the inverter such that they can be read out together as an image. The inverter further has a receiver configured to receive an encrypted and / or signed setting sequence containing the information about the assigned power class.A controller of the inverter is configured to decrypt the encrypted setting sequence and / or authenticate the signed setting sequence and to set the power class of the inverter based on the setting sequence.

[0040] In the following, the invention is further explained and described with reference to embodiments shown in the figures. Fig. 1 shows schematically a method for setting a power class of an inverter; Fig. 2 shows schematically the inverter with mobile device and Fig. 3 shows a schematic diagram of a device type plate and several class plates.

[0041] Fig. 1 shows schematically steps of a method for setting a power class of an inverter.

[0042] In step S1, a class plate 14 ( Fig. 2 ) from a plurality of class plates 14.1, 14.2, 14.3, 14.4 ( Fig. 2 ) and connected to an inverter 10 ( Fig. 2 ) is attached.

[0043] In step S2, a device type plate 12 attached to the inverter 10 ( Fig. 2 ) and the class plate 14 ( Fig. 2 ) is captured visually and device-specific information and information about the assigned performance class is read from the captured data, i.e. the captured image or images.

[0044] In step S3, the read information is authenticated. Authentication preferably includes checking whether the prerequisites for setting the power class of the inverter 10 are met. This check may, for example, involve querying a database 24 located remotely from the inverter via remote data transmission 26. For example, the database query can be used to determine whether payment has actually been made for the power class indicated on the class label 14.

[0045] In step S4, a setting sequence is transmitted to the inverter 10, wherein the setting sequence includes the information about the power class assigned to the inverter 10 that is to be set.

[0046] In step S5, the power class of the inverter 10 is set using the setting sequence.

[0047] In Fig. 2 An inverter 10 with an adjustable power class is shown schematically. The inverter 10 has a device type plate 12 containing device-specific information about the inverter 10 that is independent of the power class. The inverter 10 also has a class plate 14 consisting of a plurality of power class-specific class plates 14.1, 14.2, 14.3, 14.4 ( Fig. 3 ) is selected and contains information about the assigned power class. The device type plate 12 and the class plate 14 of the inverter 10 are image-readable. The information on the device type plate is preferably applied to the plates 12, 14 in the form of machine-readable image codes, such as barcodes or QR codes. Alternatively or additionally, the same information can be applied to the plates in human-readable form.

[0048] Preferably, the device type plate 12 and the class plate 14 are arranged on the inverter 10 such that they can be read together visually. The inverter 10 has a receiver 16 configured to receive an encrypted and / or signed setting sequence containing information about the assigned power class. The inverter 10 has a controller 18 configured to decrypt the encrypted setting sequence and / or authenticate the signed setting sequence and set the power class of the inverter 10 based on the setting sequence.

[0049] A mobile device 20 has a camera 22 configured to capture images of the device type plate 12 and the class plate 14, preferably together. Codes such as barcodes and / or QR codes can be read for this purpose. Alternatively or additionally, human-readable information can be captured and recorded by a programmed circuit, e.g., using an app, of the mobile device 20. One example of this is OCR (Optical Character Recognition) for text recognition.

[0050] The mobile device is connected to a database 24 via a remote data connection 26, e.g., a mobile phone network and / or the Internet. The database can be used, for example, to authenticate and thus verify the image-captured information.

[0051] In Fig. 3 A device type plate 12 and a class plate 14 are shown schematically, as they may be arranged, for example, on an inverter 10. If they are arranged as shown, they can be read out together visually, which accelerates the process and further increases the reliability of the process. The device type plate 12 contains device-specific information of the inverter 10, which is independent of the power class. In step S1 of the process ( Fig. 1) the class plate 14 is selected from a plurality of class plates 14.1, 14.2, 14.3, 14.4. Each of the class plates 14.1, 14.2, 14.3, 14.4 is power class-specific, i.e. it is assigned to a power class to which the inverter 10 can be set. Preferably, the inverter 10 has an assigned class plate 14.1, 14.2, 14.3, 14.4 for each power class to which it can be set. Preferably, the plurality of class plates 14.1, 14.2, 14.3, 14.4 are included in the scope of delivery of the inverter so that during installation, the one corresponding to the power class to be set can be selected and attached to the inverter 10.

Claims

1. A method for setting a power class of an inverter (10), wherein the inverter (10) comprises a device type plate (12) containing device-specific information of the inverter (10), which information is independent of the selected power class, and wherein the inverter (10) comprises a class plate (14) selected from a plurality of power class-specific class plates (14.1, 14.2, 14.3, 14.4) each assigned to one power class from a plurality of power classes and containing information about the assigned power class, wherein the method comprises the steps: - capturing in image form the device type plate (12) and the class plate (14) and reading out the device-specific information and the information about the assigned power class from the data captured as an image, - communicating a setting sequence to the inverter (10), wherein the setting sequence comprises the information about the assigned power class, - setting the power class of the inverter (10) on the basis of the setting sequence after authentication of the information read out, wherein the setting sequence, before being communicated to the inverter (10), is generated from the device-specific information and the information about the assigned power class..

2. The method as claimed in claim 1, wherein the reading out in image form is preceded by selecting the class plate (14) from the plurality of class plates (14.1, 14.2, 14.3, 14.4) and attaching, in particular permanently attaching, the class plate (14) to the inverter (10).

3. The method as claimed in claim 1 or 2, wherein the inverter (10) comprises structures for preventing the manipulation of the attached class plate (14).

4. The method as claimed in any of the preceding claims, further comprising authenticating the communicated setting sequence before setting the power class of the inverter (10).

5. The method as claimed in claim 5, wherein the authenticating comprises capturing and checking information about the person conducting the capturing in image form.

6. The method as claimed in claim 5 or 6, wherein the authenticating comprises checking whether there are preconditions for setting the power class of the inverter (10).

7. The method as claimed in claim 7, wherein the authenticating comprises checking the state of the structures in the captured image.

8. The method as claimed in any of claims 5 to 8, wherein the authenticating comprises a query of a database (24) via a remote data connection (26).

9. The method as claimed in any of claims 5 to 9, wherein, in the case of a successful authentication, the setting sequence is transmitted with an authentication section, an inverter identification section and a power class section to the inverter (10), wherein the inverter (10) checks the authentication section and the inverter identification section before a power class contained in the power class section is set, in particular set permanently.

10. The method as claimed in claim 10, wherein the capturing in image form and the transmitting of the setting sequence are effected by one and the same device (20), in particular a smartphone.

11. The method as claimed in claim 10, wherein the setting sequence is transmitted by way of a transmission means which is independent of a device (20) used for the capturing in image form.

12. The method as claimed in any of the preceding claims, characterized in that the setting sequence is encrypted and / or signed before being communicated to the inverter.

13. The method as claimed in any of the preceding claims, wherein the communication of the setting sequence is effected after checking whether a combination of the device-specific information and the information about the assigned power class is a permissible combination.

14. An inverter (10) with a settable power class, wherein the inverter comprises a device type plate (12) containing device-specific information of the inverter (10), which information is independent of the power class, and wherein the inverter (10) comprises a class plate (14) selected from a plurality of power class-specific class plates (14.1, 14.2, 14.3, 14.4) each assigned to one power class from the plurality of power classes and containing information about the assigned power class, wherein the device type plate (12) and the class plate (14) are readable in image form and wherein the inverter (10) comprises a receiver (16) configured to receive an encrypted and / or signed setting sequence based on the device-specific information and the information about the assigned power class, and wherein the inverter (10) comprises a controller (18) configured to decrypt the encrypted setting sequence and / or to authenticate the signed setting sequence and to set the power class of the inverter (10) on the basis of the setting sequence.