Method and device for controlling inverter

Abstract

The present disclosure relates to a method and a device for controlling an inverter. The method according to an embodiment of the disclosure may obtain first digital data for the AC output current of an inverter, second digital data for the AC output voltage of the inverter, third digital data for the DC input current of the inverter, and fourth digital data for the DC input voltage of the inverter on the basis of a plurality of sensors included in the inverter. In addition, the method may compare input power and output power on the basis of the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the method may determine whether there is an error in the inverter on the basis of the result of the comparison.

Description

Method and device for controlling an inverter

[0001] The present disclosure relates to a method and device for controlling an inverter.

[0002] An inverter is a device that converts direct current into alternating current. It is used in various industrial applications, such as electric motor drives, uninterruptible power supplies (UPS), and active power filters, as well as in renewable energy conversion systems and hybrid vehicles.

[0003] The internal safety diagnostic items for satisfying the Functional Safety (UL1998) standard certification for microcontrollers (Micro Controller Units; MCUs) connected to or included in inverters include the contents regarding the validity check of the A / D converter (Analog to Digital Converter). According to the prior art, in order to implement the validity check of the AC output voltage of the A / D converter, two AC current sensors are used and the values ​​sensed by the two AC current sensors are compared with each other to make a judgment.

[0004] However, if an error occurs in one of the two AC current sensors, there is a problem in that the values ​​sensed by the two AC current sensors cannot be compared with each other as in the prior art.

[0005] Therefore, there is a need for a technology that can implement a validity check of the AC output voltage of an A / D converter using a single AC current sensor.

[0006] The background technology described above is technical information that the inventor possessed for the purpose of deriving the present invention or acquired in the process of deriving the present invention, and cannot necessarily be considered as publicly known technology disclosed to the general public prior to the application for the present invention.

[0007] The present invention provides a method and device for controlling an inverter. Furthermore, the present invention provides a computer-readable recording medium having recorded thereon a program for executing the method on a computer.

[0008] The problems addressed by the present invention are not limited to those mentioned above. Other problems and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through embodiments of the present invention. Furthermore, it will be appreciated that the problems and advantages addressed by the present invention can be realized by the means and combinations thereof set forth in the claims.

[0009] As a technical means for achieving the above-described technical task, a first aspect of the present disclosure may provide a method, including the steps of: obtaining first digital data for an AC output current of an inverter, second digital data for an AC output voltage of the inverter, third digital data for a DC input current of the inverter, and fourth digital data for a DC input voltage of the inverter based on a plurality of sensors included in the inverter; comparing input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data; and determining whether there is an error in the inverter based on a result of the comparison.

[0010] A second aspect of the present disclosure may provide a device comprising at least one memory; and at least one processor; wherein the at least one processor obtains, based on a plurality of sensors included in the inverter, first digital data on AC output current of the inverter, second digital data on AC output voltage of the inverter, third digital data on DC input current of the inverter, and fourth digital data on DC input voltage of the inverter, and compares input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data, and determines whether there is an error in the inverter based on a result of the comparison.

[0011] A third aspect of the present disclosure can provide a computer-readable recording medium having recorded thereon a program for executing the method according to the first aspect on a computer.

[0012] In addition, other methods for implementing the present invention, other systems, and computer-readable recording media storing a computer program for executing the method may be further provided.

[0013] Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

[0014] According to the problem solving means of the present disclosure described above, the present disclosure acquires digital data on current and voltage of each of a grid and a PV module based on a plurality of sensors included in the inverter, compares input power and output power based on the acquired digital data, and determines whether there is an error in the inverter based on the comparison result, thereby making it possible to determine whether there is an error in the inverter using only one sensor for the output current of the inverter.

[0015] Additionally, the present disclosure can determine whether an inverter has a fault without incurring additional circuitry or additional costs.

[0016] Additionally, the present disclosure can determine whether an inverter has a fault by using an AC current sensor for the AC output of one inverter.

[0017] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0018] FIG. 1 is a drawing for explaining an example of a system for controlling an inverter according to one embodiment.

[0019] FIG. 2A is a configuration diagram illustrating an example of a user terminal according to one embodiment.

[0020] FIG. 2b is a configuration diagram illustrating an example of a server according to one embodiment.

[0021] FIG. 3 is a flowchart illustrating an example of a method for controlling an inverter according to one embodiment.

[0022] FIG. 4 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0023] FIG. 5 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0024] FIG. 6 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0025] According to one embodiment of the present disclosure, a method can obtain first digital data regarding AC output current of an inverter, second digital data regarding AC output voltage of the inverter, third digital data regarding DC input current of the inverter, and fourth digital data regarding DC input voltage of the inverter based on a plurality of sensors included in the inverter. In addition, the method can compare input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the method can determine whether an error occurs in the inverter based on the comparison result.

[0026] Hereinafter, various embodiments of the present disclosure will be described in conjunction with the accompanying drawings. Various embodiments of the present disclosure may have various modifications and various embodiments, and thus specific embodiments are illustrated in the drawings and described in detail in connection therewith. However, this is not intended to limit the various embodiments of the present disclosure to specific embodiments, but should be understood to include all modifications and / or equivalents or alternatives falling within the spirit and technical scope of the various embodiments of the present disclosure. In connection with the description of the drawings, similar reference numerals have been used for similar components.

[0027] In various embodiments of the present disclosure, expressions such as “includes” or “may include” indicate the presence of the disclosed function, operation, or component, etc., and do not limit one or more additional functions, operations, or components, etc. In addition, in various embodiments of the present disclosure, terms such as “includes” or “has” should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] In various embodiments of the present disclosure, the expression "or" includes any and all combinations of the words listed together. For example, "A or B" may include A, may include B, or may include both A and B.

[0029] Expressions such as "first," "second," "first," or "second" used in various embodiments of the present disclosure may modify various components of the various embodiments, but do not limit the components. For example, the expressions do not limit the order and / or importance of the components. The expressions may be used to distinguish one component from another. For example, a first user device and a second user device are both user devices, and represent different user devices. For example, without departing from the scope of various embodiments of the present disclosure, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

[0030] In the embodiments of the present disclosure, terms such as "module," "unit," "part," etc. are terms used to refer to components that perform at least one function or operation, and such components may be implemented as hardware or software, or a combination of hardware and software. In addition, a plurality of "modules," "units," "parts," etc. may be integrated into at least one module or chip and implemented as at least one processor, except in cases where each needs to be implemented as a separate, specific hardware.

[0031] The terms used in the various embodiments of the present disclosure are used only to describe specific embodiments and are not intended to limit the various embodiments of the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0032] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present disclosure belong.

[0033] Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in various embodiments of the present disclosure.

[0034] Hereinafter, various embodiments of the present invention will be described in detail using the attached drawings.

[0035] FIG. 1 is a drawing for explaining an example of a system for controlling an inverter according to one embodiment.

[0036] Referring to FIG. 1, the system (1) includes a user terminal (10) and a server (20). For example, the user terminal (10) and the server (20) may be connected via wired or wireless communication to transmit and receive data between each other.

[0037] For convenience of explanation, FIG. 1 illustrates that the system (1) includes a user terminal (10) and a server (20), but is not limited thereto. For example, the system (1) may include other external devices (not shown), and the operations of the user terminal (10) and the server (20) described below may be implemented by a single device (e.g., the user terminal (10) or the server (20)) or multiple devices.

[0038] The user terminal (10) may be a device including memory and a processor. For example, the user terminal (10) may be a microcontroller (MCU) that controls the inverter based on the operation of the processor. Alternatively, the user terminal (10) may be a device included in the inverter. However, examples of the user terminal (10) are not limited to those described above. That is, the user terminal (10) may be a device configured separately from the inverter.

[0039] In addition, the user terminal (10) may be a computing device including a display device and a device for receiving user input (e.g., a keyboard, a mouse, etc.), and including a memory and a processor. For example, the display device may be implemented as a touch screen and may receive user input. For example, the user terminal (10) may be, but is not limited to, a notebook PC, a desktop PC, a laptop, a tablet computer, a smart phone, etc.

[0040] The server (20) may be a device that communicates with an external device (not shown) including a user terminal (10). As an example, the server (20) may be a device that stores various data including first digital data on the AC output current of the inverter, second digital data on the AC output voltage of the inverter, third digital data on the DC input current of the inverter, fourth digital data on the DC input voltage of the inverter, output power, input power, etc. Alternatively, the server (20) may be a computing device that includes a memory and a processor and has its own computing capability. As an example, the server (20) may perform at least some of the operations of the user terminal (10) that will be described later with reference to FIGS. 1 to 6. For example, the server (20) may be a cloud server, but is not limited thereto.

[0041] The user terminal (10) can obtain digital data on the current and voltage of each of the grid and PV modules. For example, the user terminal (10) can obtain first digital data on the AC output current of the inverter, second digital data on the AC output voltage of the inverter, third digital data on the DC input current of the inverter, and fourth digital data on the DC input voltage of the inverter based on a plurality of sensors included in the inverter.

[0042] A PV module (Photovoltaic Module) may refer to a device that converts sunlight energy into electrical energy. For example, a PV module may include at least one of a solar panel, a solar cell panel, and a solar electric panel.

[0043] The user terminal (10) can compare input power and output power based on the acquired digital data. For example, the user terminal (10) can compare input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data.

[0044] The user terminal (10) can determine an error in the inverter based on the comparison result. For example, the user terminal (10) can determine whether an error exists in the inverter based on whether the comparison result falls outside a preset error range.

[0045] Meanwhile, for convenience of explanation, throughout the specification, it has been described that the user terminal (10) obtains first digital data for the AC output current of the inverter, second digital data for the AC output voltage of the inverter, third digital data for the DC input current of the inverter, and fourth digital data for the DC input voltage of the inverter based on a plurality of sensors included in the inverter, compares the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data, and determines whether there is an error in the inverter based on the comparison result, but the present invention is not limited thereto. For example, at least some of the operations performed by the user terminal (10) may be performed by the server (20).

[0046] In other words, at least some of the operations of the user terminal (10) described below with reference to FIGS. 1 to 6 may be performed by the server (20). For example, the server (20) may obtain first digital data on the AC output current of the inverter, second digital data on the AC output voltage of the inverter, third digital data on the DC input current of the inverter, and fourth digital data on the DC input voltage of the inverter based on a plurality of sensors included in the inverter, compare input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data, and determine whether there is an error in the inverter based on the comparison result.

[0047] FIG. 2A is a configuration diagram illustrating an example of a user terminal according to one embodiment.

[0048] Referring to FIG. 2A, the user terminal (100) includes a processor (110), a memory (120), an input / output interface (130), and a communication module (140). For convenience of explanation, only components related to the present invention are illustrated in FIG. 2A. Therefore, in addition to the components illustrated in FIG. 2A, other general-purpose components may be further included in the user terminal (100). In addition, it will be apparent to those skilled in the art that the processor (110), memory (120), input / output interface (130), and communication module (140) illustrated in FIG. 2A may be implemented as independent devices.

[0049] The processor (110) can process computer program commands by performing basic arithmetic, logic, and input / output operations. Here, the commands can be provided from memory (120) or an external device (e.g., a server (20), etc.). In addition, the processor (110) can generally control the operations of other components included in the user terminal (100).

[0050] First, the processor (110) can obtain first digital data for AC output current of the inverter, second digital data for AC output voltage of the inverter, third digital data for DC input current of the inverter, and fourth digital data for DC input voltage of the inverter based on a plurality of sensors included in the inverter. Specifically, the processor (110) can sense first analog data for AC output current of the inverter, second analog data for AC output voltage of the inverter, third analog data for DC input current of the inverter, and fourth analog data for DC input voltage of the inverter, respectively, based on a plurality of sensors. Then, the processor (110) can convert each of the first analog data, the second analog data, the third analog data, and the fourth analog data into a digital form based on an A / D converter, thereby obtaining the first digital data, the second digital data, the third digital data, and the fourth digital data, respectively.

[0051] The plurality of sensors may include one or more DC input voltage sensors, one or more DC input current sensors, one or more AC output voltage sensors, and one AC output current sensor. For example, the plurality of sensors may include one or more PV module voltage sensors, one or more PV module current sensors, one or more grid voltage sensors, and one grid current sensor. The PV module voltage sensor may refer to a DC voltage sensor for a DC input of the inverter. The PV module current sensor may refer to a DC current sensor for a DC input of the inverter. The grid voltage sensor may refer to an AC voltage sensor for an AC output of the inverter. The grid current sensor may refer to an AC current sensor for an AC output of the inverter.

[0052] In other words, the first analog data for the AC output current of the inverter may be sensed based on one grid current sensor.

[0053] In addition, the processor (110) can compare the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. Specifically, the processor (110) can calculate the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the processor (110) can compare the input power and the output power based on a preset ratio.

[0054] In addition, the processor (110) can determine whether there is an error in the inverter based on the comparison result. For example, the processor (110) can determine whether there is an error in the inverter based on whether the comparison result falls outside a preset error range.

[0055] Meanwhile, the processor (110) can control the operation of the inverter based on whether there is an error. Specifically, the processor (110) can transmit a PWM control signal to the gate driver based on whether there is an error. In addition, the processor (110) can control the operation of the inverter based on the operation of the gate driver according to the PWM control signal.

[0056] An inverter may be a device that converts power generated by one or more PV modules included in a solar power generation system to supply power to a load or the grid. For example, the inverter may include a microinverter connected to one or more PV modules. However, examples of inverters are not limited to those described above and may include string inverters, hybrid inverters, battery inverters, central inverters, and the like. For example, the processor (110) may control the string inverters based on frequency.

[0057] A PWM (Pulse Width Modulation) control signal may refer to a signal that controls power or data by changing the width of a signal with a constant cycle. For example, the processor (110) may control the operation of an inverter by outputting a PWM control signal to turn on or off an FET. In this case, the processor (110) may be a microcontroller.

[0058] A gate driver may refer to a device used to efficiently control a switching element such as a FET. For example, the gate driver may amplify a PWM control signal output from a processor (110) and supply an appropriate voltage and / or current required for the gate of the FET.

[0059] A FET (Field Effect Transistor) can refer to a semiconductor device that controls current using a voltage applied to the gate. For example, FETs can include converter FETs, HB FETs (Half-Bridge FETs), and inverter FETs.

[0060] Specific examples of how the processor (110) operates according to one embodiment are described with reference to FIGS. 3 to 6.

[0061] The processor (110) may be implemented as an array of a plurality of logic gates, or may be implemented as a combination of a general-purpose microprocessor and a memory storing a program that can be executed on the microprocessor. For example, the processor (110) may include a general-purpose processor, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a controller, a microcontroller, a state machine, etc. In some environments, the processor (110) may include an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc. For example, the processor (110) may refer to a combination of processing devices, such as a combination of a digital signal processor (DSP) and a microprocessor, a combination of a plurality of microprocessors, a combination of one or more microprocessors coupled with a digital signal processor (DSP) core, or any other such combination of configurations.

[0062] Meanwhile, the processor (110) may be included in a microcontroller (MCU). The microcontroller (MCU) may control the inverter based on the operation of the processor (110). However, examples of the processor (110) are not limited to those described above.

[0063] The memory (120) may include any non-transitory computer-readable recording medium. As an example, the memory (120) may include a non-permanent mass storage device such as a random access memory (RAM), a read only memory (ROM), a disk drive, a solid state drive (SSD), a flash memory, etc. As another example, the non-permanent mass storage device such as a ROM, an SSD, a flash memory, a disk drive, etc. may be a separate permanent storage device distinct from the memory. In addition, the memory (120) may store an operating system (OS) and at least one program code (e.g., code for the processor (110) to perform an operation to be described later with reference to FIGS. 3 to 6).

[0064] Meanwhile, the memory (120) may be a buffer that temporarily stores input / output data. The buffer may be included in a microcontroller (MCU) or an inverter. However, examples of the memory (120) are not limited to those described above.

[0065] These software components may be loaded from a computer-readable recording medium separate from the memory (120). This separate computer-readable recording medium may be a recording medium that can be directly connected to the user terminal (100), and may include, for example, a computer-readable recording medium such as a floppy drive, a disk, a tape, a DVD / CD-ROM drive, a memory card, etc. Alternatively, the software components may be loaded into the memory (120) through a communication module (140) other than a computer-readable recording medium. For example, at least one program may be loaded into the memory (120) based on a computer program (e.g., a computer program for the processor (110) to perform the operations described below with reference to FIGS. 3 to 6) that is installed by files provided by developers or a file distribution system that distributes installation files of applications through the communication module (140).

[0066] The input / output interface (130) may be a means for interfacing with a device (e.g., a keyboard, a mouse, etc.) for input or output that may be connected to or included in the user terminal (100). The input / output interface (130) may be configured separately from the processor (110), but is not limited thereto, and the input / output interface (130) may also be configured to be included in the processor (110).

[0067] The communication module (140) may provide a configuration or function for the server (20) and the user terminal (100) to communicate with each other via a network. In addition, the communication module (140) may provide a configuration or function for the user terminal (100) to communicate with other external devices. For example, control signals, commands, data, etc. provided under the control of the processor (110) may be transmitted to the server (20) and / or the external device via the communication module (140) and the network.

[0068] FIG. 2b is a configuration diagram illustrating an example of a server according to one embodiment.

[0069] Referring to FIG. 2B, the server (200) includes a processor (210), a memory (220), and a communication module (230). For convenience of explanation, only components related to the present invention are illustrated in FIG. 2B. Therefore, in addition to the components illustrated in FIG. 2B, other general-purpose components may be further included in the server (200). Furthermore, it will be apparent to those skilled in the art that the processor (210), memory (220), and communication module (230) illustrated in FIG. 2B may be implemented as independent devices.

[0070] The processor (210) can obtain first digital data on the AC output current of the inverter, second digital data on the AC output voltage of the inverter, third digital data on the DC input current of the inverter, and fourth digital data on the DC input voltage of the inverter based on a plurality of sensors included in the inverter. In addition, the processor (110) can compare the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the processor (210) can determine whether there is an error in the inverter based on the comparison result.

[0071] In other words, at least one of the operations of the processor (110) described above with reference to FIG. 2A may be performed by the processor (210). In this case, the user terminal (100) may output information transmitted from the server (200) through a separate display device (not shown).

[0072] Meanwhile, since the implementation example of the processor (210) is the same as the implementation example of the processor (110) described above with reference to FIG. 2a, a detailed description thereof is omitted.

[0073] The memory (220) may store various data, such as data required for the operation of the processor (210) and data generated according to the operation of the processor (210). In addition, the memory (220) may store an operating system (OS) and at least one program (e.g., a program required for the operation of the processor (210).

[0074] Meanwhile, the implementation example of the memory (220) is the same as the implementation example of the memory (120) described above with reference to FIG. 2a, so a detailed description is omitted.

[0075] The communication module (230) may provide a configuration or function for the server (200) and the user terminal (100) to communicate with each other via a network. In addition, the communication module (140) may provide a configuration or function for the server (200) to communicate with other external devices. For example, control signals, commands, data, etc. provided under the control of the processor (210) may be transmitted to the user terminal (100) and / or the external device via the communication module (230) and the network.

[0076] FIG. 3 is a flowchart illustrating an example of a method for controlling an inverter according to one embodiment.

[0077] Referring to FIG. 3, the method for controlling an inverter is composed of steps that are processed in time series in the user terminal (10, 100) or processor (110) illustrated in FIGS. 1 and 2A. Therefore, even if the content is omitted below, the content described above with respect to the user terminal (10, 100) or processor (110) illustrated in FIGS. 1 and 2A can also be applied to the method for controlling the inverter of FIG. 3.

[0078] Additionally, as described above with reference to FIGS. 1 and 2b, at least one of the steps of the method for controlling the inverter of FIG. 3 may be processed in the server (20, 200) or the processor (210).

[0079] At step S310, the processor (110) obtains first digital data on AC output current of the inverter, second digital data on AC output voltage of the inverter, third digital data on DC input current of the inverter, and fourth digital data on DC input voltage of the inverter based on a plurality of sensors included in the inverter.

[0080] The plurality of sensors may include one or more DC input voltage sensors, one or more DC input current sensors, one or more AC output voltage sensors, and one AC output current sensor. For example, the plurality of sensors may include one or more PV module voltage sensors, one or more PV module current sensors, one or more grid voltage sensors, and one grid current sensor.

[0081] A DC input voltage sensor may refer to a device that senses the voltage input to an inverter. For example, a DC input voltage sensor may include a device that senses the voltage output from a PV module and input to an inverter.

[0082] A DC input current sensor may refer to a device that senses the current input to an inverter. For example, a DC input current sensor may include a device that senses the current output from a PV module and input to an inverter.

[0083] An AC output voltage sensor may refer to a device that senses the voltage output from an inverter. For example, the AC output voltage sensor may include a device that senses the voltage output from the inverter and input to the grid or load.

[0084] An AC output current sensor may refer to a device that senses the current output from an inverter. For example, an AC output current sensor may include a device that senses the current output from an inverter and input to a grid or a load.

[0085] For example, each of the plurality of sensors may sense first analog data for AC output current of the inverter, second analog data for AC output voltage of the inverter, third analog data for DC input current of the inverter, and fourth analog data for DC input voltage of the inverter, respectively. In addition, the A / D converter may convert each of the first analog data, the second analog data, the third analog data, and the fourth analog data into digital form to generate each of the first digital data, the second digital data, the third digital data, and the fourth digital data. Here, the first analog data may refer to data sensed based on one AC output current sensor.

[0086] At step S320, the processor (110) compares the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data.

[0087] Specifically, the processor (110) can calculate input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the processor (110) can compare the input power and the output power based on a preset ratio.

[0088] For example, the processor (110) can obtain first digital data including a current value of 1.463 A and second digital data including a voltage value of 240.520 V. In addition, the processor (110) can obtain third digital data including a current value of 9.272 A and fourth digital data including a voltage value of 39.686 V. In addition, the processor (110) can calculate an output power including a power value of 1.463 x 240.520 = 351.88076 W based on the first digital data and the second digital data. In addition, the processor (110) can calculate an input power including a power value of 9.272 x 39.686 = 367.968592 W based on the third digital data and the fourth digital data. In addition, the processor (110) can calculate an efficiency value based on the output power and the input power. The processor (110) can calculate an efficiency value of 95.63% by multiplying the value obtained by dividing the output power by the input power by 100. Then, the processor (110) can compare the preset ratio value of 95% with the efficiency value of 95.63%.

[0089] The preset ratio may include the expected ratio of the output power generated relative to the input power. The processor (110) may calculate a ratio value based on the preset ratio, which may refer to a preset efficiency value. For example, the preset ratio may be set considering the performance of the inverter. However, examples of preset ratios are not limited to those described above.

[0090] At step S330, the processor (110) determines whether there is an error in the inverter based on the comparison result. Specifically, the processor (110) can determine whether there is an error in the inverter based on whether the comparison result falls outside a preset error range.

[0091] The processor (110) may determine whether there is an error in the inverter based on the efficiency value being greater than or equal to a preset ratio value. For example, the processor (110) may determine that there is no error in the inverter based on the efficiency value of 95.63% being greater than or equal to the preset ratio value of 95%.

[0092] Alternatively, the processor (110) may determine whether there is an error in the inverter based on whether the difference between the efficiency value and the preset ratio value is outside the preset error range. For example, if the difference between the efficiency value and the preset ratio value is 0.63% and the preset error range is 1%, the processor (110) may determine that there is no error in the inverter because the difference between the efficiency value and the preset ratio value does not exceed the preset error range.

[0093] However, the example in which the processor (110) determines whether there is an error in the inverter based on the comparison result is not limited to the above-described example.

[0094] Meanwhile, the processor (110) can control the operation of the inverter based on whether there is an error. Specifically, the processor (110) can transmit a PWM control signal to the gate driver based on whether there is an error. In addition, the processor (110) can control the operation of the inverter based on the operation of the gate driver according to the PWM control signal. For example, if the processor (110) determines that an error has occurred in the inverter, it can transmit a PWM OFF signal to the gate driver. In addition, the gate driver can stop the operation of the inverter by turning off the FET (e.g., converter FET, HB FET, inverter FET, etc.) based on the PWM OFF signal.

[0095] An inverter may be a device that converts power generated by one or more PV modules included in a solar power generation system to supply power to a load or the grid. For example, the inverter may include a microinverter connected to the PV module. However, examples of inverters are not limited to those described above. That is, the inverter may include not only a microinverter, but also a string inverter, a hybrid inverter, a battery inverter, a central inverter, and the like.

[0096] FIG. 4 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0097] Referring to FIG. 4, a system for controlling an inverter can be configured to include a PV module (4), a string (40), and a micro inverter (400).

[0098] A string (40) can be configured by connecting multiple PV modules (4) in series via a power line. A plurality of such strings (40) can be provided and connected in parallel.

[0099] A micro inverter (400) can be provided in each of a plurality of PV modules (4), and can convert direct current power generated in the PV module (4) into alternating current and output it to the grid (41).

[0100] Meanwhile, the micro inverter (400) may be controlled based on the operation of the processor (110) described above. The processor (110) may be a device included in the micro inverter (400) or a device included in a microcontroller (MCU) constituting the micro inverter (400). Alternatively, the processor (110) may be a device configured separately from the micro inverter (400).

[0101] Meanwhile, the inverter included in the system for controlling the inverter has been described as including a micro inverter (400), but is not limited thereto. In other words, the inverter included in the system for controlling the inverter may include a string inverter.

[0102] Another example of a system for controlling an inverter according to one embodiment is described with reference to FIG. 4, but examples of a system for controlling an inverter are not limited to those described above.

[0103] FIG. 5 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0104] Referring to FIG. 5, the system (2) includes a PV module (510), a DC-DC converter (521), a DC-AC converter (522), a grid (530), a PV module current sensor (523), a PV module voltage sensor (524), a grid current sensor (525), a grid voltage sensor (526), ​​an A / D converter (527), a controller (528), and a gate driver (529). The controller (528) may refer to a device including a memory and a processor. For example, the controller (528) may include a microcontroller (MCU).

[0105] For convenience of explanation, FIG. 5 illustrates that the system (1) includes a PV module (510), a DC-DC converter (521), a DC-AC converter (522), a grid (530), a PV module current sensor (523), a PV module voltage sensor (524), a grid current sensor (525), a grid voltage sensor (526), ​​an A / D converter (527), a controller (528), and a gate driver (529), but is not limited thereto. For example, the system (2) may include other external devices (not shown).

[0106] The inverter may include a DC-DC converter (521), a DC-AC converter (522), a PV module current sensor (523), a PV module voltage sensor (524), a grid current sensor (525), a grid voltage sensor (526), ​​an A / D converter (527), a controller (528), and a gate driver (529).

[0107] Here, the inverter may be a microinverter, but examples of inverters are not limited to those described above.

[0108] The inverter can convert input power generated from the PV module (510) into output power and output it to the grid (530). In this process, the inverter can determine whether there is an error in the inverter based on the input power and the output power, and control the operation of the inverter based on the error. Specifically, the DC-DC conversion unit (521) and the DC-AC conversion unit (522) included in the inverter can convert input power generated from the PV module (510) into output power and output it to the grid (530). In addition, the PV module current sensor (523), the PV module voltage sensor (524), the grid current sensor (525), and the grid voltage sensor (526) can each sense first analog data for the AC output current of the inverter, second analog data for the AC output voltage of the inverter, third analog data for the DC input current of the inverter, and fourth analog data for the DC input voltage of the inverter, respectively. And, the A / D converter (527) can convert the first analog data, the second analog data, the third analog data, and the fourth analog data into digital form, respectively, to generate the first digital data, the second digital data, the third digital data, and the fourth digital data, respectively. And, the controller (528) can obtain the first digital data, the second digital data, the third digital data, and the fourth digital data. The controller (528) can compare the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. And, the controller (528) can determine whether there is an error in the inverter based on the comparison result.

[0109] In addition, the controller (528) can control the operation of the inverter based on whether there is an error. Specifically, the controller (528) can transmit a PWM control signal to the gate driver (529) based on whether there is an error. In addition, the gate driver (529) can control the operation of one or more of the converter FET, HB FET, and inverter FET included in the inverter based on the PWM control signal.

[0110] FIG. 6 is a diagram illustrating another example of a system for controlling an inverter according to one embodiment.

[0111] Referring to FIG. 6, the system (3) includes a PV module (610), a grid (620), a converter FET (631), a transformer (632), an HB FET (633), a DC link (634), an inverter FET (635), a PV module current sensor (636), a PV module voltage sensor (637), a grid current sensor (638), a grid voltage sensor (639), a DC link voltage sensor (640), an A / D converter (643), a controller (641), and a gate driver (642). The controller (641) may refer to a device including a memory and a processor. For example, the controller (641) may include a microcontroller (MCU).

[0112] For convenience of explanation, FIG. 6 illustrates that the system (3) includes a PV module (610), a grid (620), a converter FET (631), a transformer (632), an HB FET (633), a DC link (634), an inverter FET (635), a PV module current sensor (636), a PV module voltage sensor (637), a grid current sensor (638), a grid voltage sensor (639), a DC link voltage sensor (640), an A / D converter (643), a controller (641), and a gate driver (642), but is not limited thereto. For example, the system (3) may include other external devices (not shown).

[0113] The inverter may include a converter FET (631), a transformer (632), an HB FET (633), a DC link (634), an inverter FET (635), a PV module current sensor (636), a PV module voltage sensor (637), a grid current sensor (638), a grid voltage sensor (639), a DC link voltage sensor (640), an A / D converter (643), a controller (641), and a gate driver (642). The converter FET (631), the transformer (632), the HB FET (633), and the DC link (634) may be included in a DC-DC conversion unit. The inverter FET (635) may be included in a DC-AC conversion unit.

[0114] Here, the inverter may be a microinverter, but examples of inverters are not limited to those described above.

[0115] The inverter can convert input power generated from the PV module (610) into output power and output it to the grid (620). In this process, the inverter can determine whether there is an error in the inverter based on the input power and the output power, and control the operation of the inverter based on the error. Specifically, the converter FET (631), the transformer (632), the HB FET (633), the DC link (634), and the inverter FET (635) included in the inverter can convert input power generated from the PV module (610) into output power and output it to the grid (620). In addition, the PV module current sensor (636), the PV module voltage sensor (637), the grid current sensor (638), and the grid voltage sensor (639) can each sense first analog data for the AC output current of the inverter, second analog data for the AC output voltage of the inverter, third analog data for the DC input current of the inverter, and fourth analog data for the DC input voltage of the inverter, respectively. Meanwhile, the DC link voltage sensor (640) can sense fifth analog data regarding the voltage of the DC link. In addition, the A / D converter (643) can convert the first analog data, the second analog data, the third analog data, and the fourth analog data into digital form, respectively, to generate first digital data, second digital data, third digital data, and fourth digital data, respectively. In addition, the controller (641) can obtain the first digital data, the second digital data, the third digital data, and the fourth digital data. The controller (641) can compare the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data. In addition, the controller (641) can determine whether there is an error in the inverter based on the comparison result.

[0116] In addition, the controller (641) can control the operation of the inverter based on whether there is an error. Specifically, the controller (641) can transmit a PWM control signal to the gate driver (642) based on whether there is an error. In addition, the gate driver (642) can control the operation of one or more of the converter FET (631), the HB FET (633), and the inverter FET (635) included in the inverter based on the PWM control signal.

[0117] As described above, in the present disclosure, digital data on current and voltage of each of a grid and a PV module is acquired based on a plurality of sensors included in an inverter, input power and output power are compared based on the acquired digital data, and an error in the inverter is determined based on the comparison result, thereby making it possible to determine whether an error in the inverter exists using only one sensor for the output current of the inverter. In addition, the present disclosure can determine whether an error in the inverter exists without incurring additional circuits and additional costs. In addition, the present disclosure can determine whether an error in the inverter exists using an AC current sensor for the AC output of one inverter.

[0118] Meanwhile, the above-described method can be written as a program that can be executed on a computer, and can be implemented on a general-purpose digital computer that runs the program using a computer-readable recording medium. In addition, the structure of the data used in the above-described method can be recorded on a computer-readable recording medium through various means. The computer-readable recording medium includes storage media such as magnetic storage media (e.g., ROM, RAM, USB, floppy disk, hard disk, etc.) and optical reading media (e.g., CD-ROM, DVD, etc.).

[0119] Meanwhile, the above-described method may be provided as a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloading or uploading) through an application store (e.g., Play Store™) or directly between two user devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0120] Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from the essential characteristics of the above-described invention. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the claims, not the foregoing description, is defined by the scope of the patent, and should be interpreted to encompass all differences within the scope equivalent thereto.

Claims

1. A step of obtaining first digital data on AC output current of the inverter, second digital data on AC output voltage of the inverter, third digital data on DC input current of the inverter, and fourth digital data on DC input voltage of the inverter based on a plurality of sensors included in the inverter; A step of comparing input power and output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data; and A method comprising a step of determining whether there is an error in the inverter based on the comparison result.

2. In paragraph 1, The above multiple sensors are, A method comprising at least one DC input voltage sensor, at least one DC input current sensor, at least one AC output voltage sensor and one AC output current sensor.

3. In paragraph 1, The above acquisition steps are: A step of sensing first analog data for AC output current of the inverter, second analog data for AC output voltage of the inverter, third analog data for DC input current of the inverter, and fourth analog data for DC input voltage of the inverter, based on the plurality of sensors; A step of converting each of the first analog data, the second analog data, the third analog data and the fourth analog data into a digital form to obtain each of the first digital data, the second digital data, the third digital data and the fourth digital data, The above first analog data is, A method of sensing based on one AC output current sensor.

4. In paragraph 1, The above comparing steps are: A step of calculating the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data; and A method comprising the step of comparing the input power and the output power based on a preset ratio.

5. In paragraph 1, The above decision step is, A method comprising a step of determining whether there is an error in the inverter based on whether the comparison result is outside a preset error range.

6. In paragraph 1, A step of transmitting a PWM control signal to a gate driver based on whether or not the above error is present; and A method further comprising a step of controlling the operation of the inverter based on the operation of the gate driver according to the PWM control signal.

7. In paragraph 1, The above inverter, A method for converting power generated from at least one PV module included in a solar power generation system to supply power to a load or grid.

8. In paragraph 7, The above inverter, A method comprising at least one micro-inverter connected to at least one PV module.

9. At least one memory; and comprising at least one processor; At least one processor, Based on a plurality of sensors included in the inverter, first digital data on AC output current of the inverter, second digital data on AC output voltage of the inverter, third digital data on DC input current of the inverter, and fourth digital data on DC input voltage of the inverter are acquired, Comparing the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data, A device that determines whether there is an error in the inverter based on the results of the comparison.

10. In paragraph 9, The above multiple sensors are, A device comprising at least one DC input voltage sensor, at least one DC input current sensor, at least one AC output voltage sensor, and one AC output current sensor.

11. In paragraph 9, The above multiple sensors are, Sensing first analog data for AC output current of the inverter, second analog data for AC output voltage of the inverter, third analog data for DC input current of the inverter, and fourth analog data for DC input voltage of the inverter, respectively, The above inverter, Converting each of the first analog data, the second analog data, the third analog data and the fourth analog data into a digital form to generate each of the first digital data, the second digital data, the third digital data and the fourth digital data, The above first analog data is, A device sensed based on a single current sensor.

12. In paragraph 9, At least one processor, Calculate the input power and the output power based on the first digital data, the second digital data, the third digital data, and the fourth digital data, A device that compares the input power and the output power based on a preset ratio.

13. In paragraph 9, At least one processor, A device that determines whether there is an error in the inverter based on whether the comparison result is outside a preset error range.

14. In paragraph 9, further comprising a gate driver that operates based on a PWM control signal; At least one processor, Based on the above error, a PWM control signal is transmitted to the gate driver, A device that controls the operation of the inverter based on the operation of the gate driver according to the PWM control signal.

15. In paragraph 9, The above inverter, A device that performs power conversion to supply power generated from at least one PV module included in a solar power generation system to a load or grid.

16. In paragraph 15, The above inverter, A device comprising at least one micro-inverter connected to at least one PV module.

17. A computer-readable recording medium recording a program for executing the method according to paragraph 1 on a computer.

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