Device for performing safety function, and solar power generation system comprising same

Abstract

A device for performing a safety function, according to one aspect, comprises: an electronic circuit that includes a switching element, a first resistor, and a second resistor; and a processor that controls the operation of the electronic circuit so that, when a predetermined condition is satisfied, a first voltage applied to the electronic circuit is converted into a second voltage.

Description

Device performing safety function and solar power generation system including same

[0001] The present invention relates to a device performing a safety function and a solar power generation system including the same.

[0002] Solar power generation systems must ensure stability by identifying potential abnormalities and emergencies in real time during operation. In the event of an emergency, solar power generation systems must be equipped with safety features that shut off the output of photovoltaic (PV) modules and control the voltage below a safety voltage within a specified timeframe, tailored to the requirements of each country and product. In this regard, as global industrial safety standards diversify, rapid shutdown (RSD) functionality is increasingly required in solar power generation systems.

[0003] Meanwhile, module-level power conversion devices (or module-level power conditioning devices) (hereinafter referred to as 'MLPE') are being introduced to solar power generation systems to improve the performance of PV modules and increase power generation efficiency.

[0004] Meanwhile, there is a demand for the introduction of a device that performs safety functions while stably outputting a safe voltage even in emergency situations and is easy to implement.

[0005] The purpose is to provide a device that performs a safety function and a solar power generation system including the same, which can perform the safety function more stably in an emergency situation.

[0006] The present invention provides a device that performs a safety function and a solar power generation system including the same, which can easily perform a safety function without a complex configuration such as an integrated circuit.

[0007] A device for performing a safety function according to one aspect includes an electronic circuit including a switching element, a first resistor, and a second resistor; and a processor for controlling the operation of the electronic circuit such that a first voltage applied to the electronic circuit is converted to a second voltage when a predetermined condition is satisfied.

[0008] A solar power generation system according to another aspect includes a plurality of PV (Photovoltaic) modules; and a device connected to each of the plurality of PV modules; the device includes an electronic circuit including a switching element, a first resistor, and a second resistor; and a processor controlling the electronic circuit such that a first voltage applied to the electronic circuit is converted into a second voltage according to a state of the solar power generation system.

[0009] Since a safety voltage is output using a resistor, safety functions can be implemented safely without the need for complex circuit configurations.

[0010] The level of safety voltage can be easily adjusted or set according to the forward characteristics of the diode.

[0011] Devices that perform safety functions can operate stably without causing any burden, such as power loss, on the entire system.

[0012] A safe voltage can be output using simple semiconductor characteristics without the complex process of setting the safe voltage through control of a PWM controller.

[0013] By simply configuring a simple circuit, a safe voltage can be output, eliminating the instability of voltage control that arises from complex control algorithms and defects in semiconductor integrated circuits.

[0014] The level of safety voltage can be designed to match the simple diode forward characteristics, allowing for agile circuit changes according to the safety requirements of the user.

[0015] FIG. 1 is a diagram illustrating an example of a solar power generation system according to one embodiment.

[0016] FIG. 2 is a block diagram illustrating an example of a device performing a safety function according to one embodiment.

[0017] FIG. 3 is a diagram illustrating an example of an electronic circuit according to one embodiment.

[0018] FIG. 4 is a diagram illustrating another example of an electronic circuit according to one embodiment.

[0019] FIG. 5 is a diagram illustrating an example of how a device performing a safety function according to one embodiment operates.

[0020] A device for performing a safety function according to one aspect includes an electronic circuit including a switching element, a first resistor, and a second resistor; and a processor for controlling the operation of the electronic circuit such that a first voltage applied to the electronic circuit is converted to a second voltage when a predetermined condition is satisfied.

[0021] The terms used in the examples are selected from widely used, current terms, as much as possible. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, the applicant may arbitrarily select terms, in which case their meanings will be described in detail in the relevant description. Therefore, the terms used in the specification should be defined based on their intended meaning and the overall content of the specification, rather than simply their names.

[0022] When a part of a specification is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0023] Additionally, terms including ordinal numbers, such as "first" or "second," used in the specification may be used to describe various components, but the components should not be limited by the terms. The terms may be used to distinguish one component from another.

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. In the drawings, portions irrelevant to the description may be omitted for clarity in describing the present invention, and the same reference numerals may be used throughout the specification for identical or similar components.

[0025] FIG. 1 is a diagram illustrating an example of a solar power generation system according to one embodiment.

[0026] Referring to Fig. 1, a solar power generation system (1) includes a PV module (110) and a device (120). Meanwhile, in addition to the components illustrated in Fig. 1, other general components may be further included in the system (1).

[0027] A PV module (110) is a module that generates electricity using solar energy. For example, a plurality of PV modules (110) may be included in the system (1).

[0028] The device (120) is a device that converts the output voltage of a connected PV module (110) into a predefined safety voltage when an emergency occurs. Examples of the safety function performing device (120) are described with reference to FIGS. 2 to 4.

[0029] For example, the device (120) may be an MLPE or a device connected to an MLPE. Alternatively, the device (120) may be a device included in an MLPE. Here, the MLPE may also be an optimizer.

[0030] For example, if the MLPE is an optimizer, the system (1) may include a single inverter. In this case, the single MLPE may be connected to a single PV module (110), and the MLPE may optimize the power output from the PV module (110) and output it to a single inverter (e.g., a string inverter). The current converted in the inverter (e.g., converting direct current to alternating current) may be output to a load or a grid.

[0031] As illustrated in FIG. 1, a single device (120) may be connected to a single PV module (110), but is not limited thereto. For example, depending on the structure adopted by the solar power generation system (1), PV modules (110) and devices may be connected in a many-to-one or many-to-many manner, and the connection form is not limited to any one. In another embodiment, the system (1) may be configured in a form in which a plurality of groups are connected in series, each group consisting of n PV modules (110) (where n is a natural number greater than or equal to 2) and n devices (120).

[0032] Additionally, although not shown in FIG. 1, the solar power generation system (1) may include an MLPE, an inverter, or a grid.

[0033] The device (120) can share resources such as a processor built into the MLPE. Accordingly, the MLPE can be connected to the PV module (110) in a one-to-one correspondence, but is not limited thereto. For example, depending on the structure adopted by the solar power generation system (1), the PV module (110) and the MLPE can be connected in a one-to-many or many-to-many manner, and the connection form is not limited to either one.

[0034] For example, if the MLPE is an optimizer, the inverter can be installed in a PCS (Power Conversion System) to perform power conversion to supply power generated from PV modules (110) to a load or grid.

[0035] The device (120), MLPE, or inverter analyzes various data received from the PV module (110), MLPE, load, grid, etc. to monitor the operating status of the system (1). If an abnormal situation occurs during monitoring, i.e., if switching to a safe mode is required, a safe voltage can be output through the device (120).

[0036] When the system (1) includes an MLPE, the output voltage of the PV module (110) can be converted to a safe voltage by controlling the switching element of the buck converter. In this case, a PWM (Pulse Width Modulation) controller must be provided to control the switching element. Therefore, if the PWM controller breaks down or an error occurs in the control algorithm, the safe voltage may not be accurately output or controlled. In addition, since the PWM controller and the switching element are generally implemented as a semiconductor integrated circuit (IC), their control or circuit implementation is not simple.

[0037] Meanwhile, if the system (1) does not include an MLPE, the output voltage of the PV module (110) can be converted to a safe voltage by the control of a separate regulator such as an LDO (Low Dropout). However, even in the case of a regulator, since it is implemented by a semiconductor integrated circuit (IC), the control or circuit implementation of the regulator is not simple.

[0038] In the present invention, a device (120) is proposed that can stably perform a safety function according to a standard and can easily perform a safety function without being complexly configured by an integrated circuit or the like.

[0039] Hereinafter, the configuration and operation of a device (120) according to one embodiment of the present invention will be specifically described with reference to the drawings.

[0040] FIG. 2 is a block diagram illustrating an example of a device performing a safety function according to one embodiment.

[0041] Referring to FIG. 2, the device (120) includes an electronic circuit (121) and a processor (122).

[0042] The electronic circuit (121) can convert the output voltage of the PV module (110) into a safe voltage. An example of the electronic circuit (121) is described with reference to FIGS. 3 and 4.

[0043] The processor (122) controls the electronic circuit (121) according to the status of the solar power generation system (1). For example, the processor (122) can control the electronic circuit (121) when a predetermined condition is satisfied. Here, when the predetermined condition is satisfied, it means that the output voltage of the PV module (110) is not properly output as is. For example, when the predetermined condition is satisfied, it may be a state requiring a transition to a safe mode.

[0044] For example, the processor (122) may be a processor separately provided for the purpose of performing a safety function, but is not limited thereto. For example, the processor (122) may be a processor included in an MLPE. If the processor (122) is a processor included in an MLPE, the configuration of the device (120) may be simplified and production costs may be reduced. Hereinafter, for convenience of explanation, the processor (122) is described as a processor included in an MLPE.

[0045] For example, the processor (122) may include a microcontroller unit (MCU) for power control. The processor (122) may execute software such as a program to control components (e.g., hardware or software components) included in the device (120) or MLPE, and may process various data or perform operations.

[0046] For example, the processor (122) may perform serial communication with the inverter or power line communication (PLC) to receive control signals, shutdown signals, etc. required for power optimization.

[0047] For example, the processor (122) may receive a shutdown signal from an inverter that monitors the overall operating status of the solar power generation system (1), but is not limited thereto.

[0048] For example, the processor (122) may monitor the operating status of the MLPE, etc., and generate a shutdown signal when an abnormal situation is detected. Specifically, the processor (122) may analyze various data received from the operating data of the MLPE or the PV module (110), load, grid, etc., to monitor the operating status, and generate a shutdown signal when an abnormal situation occurs.

[0049] FIG. 3 is a diagram illustrating an example of an electronic circuit according to one embodiment.

[0050] Referring to Figure 3, when switching to safe mode, the electronic circuit (1211) outputs the voltage (V) of the PV module (110). pv ) to the safety voltage (V safety voltage ) and output it.

[0051] The electronic circuit (1211) may include a switching element (SW), a first resistor (R1), and a second resistor (R2). For example, the switching element (SW) and the first resistor (R1) may be connected in parallel, and the second resistor (R2) may be connected in series with the parallel connection of the switching element (SW) and the first resistor (R1).

[0052] At this time, the position between the parallel connection of the switching element (SW) and the first resistor (R1) and the second resistor (R2) is not limited to any one. For example, in addition to the electronic circuit (1211) illustrated in FIG. 3, the parallel connection of the switching element (SW) and the first resistor (R1) may be placed on a line connected to the positive (+) output terminal of the PV module (110).

[0053] For example, the switching element (SW) may be implemented as a FET (Field Effect Transistor), BJT (Bipolar Junction Transistor), etc., but is not limited thereto. In other words, anything that can be turned on or off under the control of the processor (122) can be considered a switching element (SW) without limitation.

[0054] The processor (122) can control the electronic circuit (1211) depending on the status of the solar power generation system (1). For example, the processor (122) can control the electronic circuit (121) when a predetermined condition is satisfied. For example, when a transition to a safe mode is required, the processor (122) can input an off signal to the switching element (SW) (i.e., turn it off).

[0055] When the switching element (SW) is turned off, the output voltage (V) of the PV module (110) applied to the electronic circuit (1211) pv) is distributed in proportion to the resistance values ​​of the first resistor (R1) and the second resistor (R2). Therefore, the electronic circuit (1211) can output a safety voltage applied to the second resistor (R2) as the switching element (SW) operates off.

[0056] That is, the voltage applied to the second resistor (R2) is the safety voltage (V safety voltage ), the resistance values ​​of the first resistor (R1) and the second resistor (R2) can be determined in consideration of the specifications for the safety voltage output of the system (1) and the structure of the system (1). Here, the resistance value of the first resistor (R1) can be greater than or equal to the resistance value of the second resistor (R2). For example, the resistance value of the first resistor (R1) can have a value much greater than the resistance value of the second resistor (R2).

[0057] As described above, the processor (122) outputs a safe voltage through a simple principle called the voltage distribution law using a resistor, so that the safety function can be safely performed even if the electronic circuit (1211) is not configured as a complex circuit.

[0058] In addition, when using an electronic circuit (1211), the instability of safety voltage control caused by the existing complex control algorithm and defects in semiconductor integrated circuits (ICs) can be resolved.

[0059] In addition, even when the range of the output voltage of the PV module (110) is high, it is possible to sufficiently control the safe voltage by only distributing the resistance of the processor (122).

[0060] FIG. 4 is a diagram illustrating another example of an electronic circuit according to one embodiment.

[0061] Comparing FIGS. 3 and 4, the electronic circuit (1212) of FIG. 4 differs from the electronic circuit (1211) of FIG. 3 in that it further includes a diode (D). Therefore, the first resistor (R1), the second resistor (R2), and the switching element (SW) of the electronic circuit (1212) are the same as those of the electronic circuit (1211) of FIG. 3, and thus a detailed description thereof will be omitted.

[0062] The diode (D) is connected in parallel with the switching element (SW) and the first resistor (R1) and in series with the second resistor (R2).

[0063] Similar to FIG. 3, the positions between the parallel connection of the switching element (SW) and the first resistor (R1) and the series connection of the second resistor (R2) and the diode (D) are not limited to either one. For example, in addition to the electronic circuit (1212) illustrated in FIG. 4, the parallel connection of the switching element (SW) and the first resistor (R1) may be arranged on a line connected to the positive (+) output terminal of the PV module (110). In addition, the positions of the second resistor (R2) and the diode (D) are not limited to FIG. 4, and the arrangements may be interchanged.

[0064] As described above with reference to FIG. 3, when switching to a safe mode is required, the processor (122) can input an off signal to the switching element (SW) (i.e., turn it off).

[0065] When the switching element (SW) is turned off, the output voltage (V) of the PV module (110) applied to the electronic circuit (1212) pv ) is distributed in proportion to the resistance values ​​of the first resistor (R1), the second resistor (R2), and the diode (D).

[0066] At this time, the safety voltage (V safety voltage) is the sum of the forward voltage of the diode (D) and the voltage distributed to the second resistor (R2). That is, the electronic circuit (1212) can output a safety voltage across the second resistor (R2) and the diode (D) when the switching element (SW) is turned off.

[0067] Accordingly, the resistance value of the first resistor (R1) and the resistance value of the second resistor (R2) can be determined by considering the resistance value of the diode (D), the specification for the safety voltage output of the system (1), and the structure of the system (1). In addition, the resistance value of the first resistor (R1) can be greater than or equal to the resistance value of the second resistor (R2). For example, the resistance value of the first resistor (R1) can have a value much greater than the resistance value of the second resistor (R2).

[0068] Meanwhile, the PV module (110) has an output voltage (V) depending on the characteristics of the product, such as the manufacturer and material. pv )(In particular, the maximum output voltage (V oc )) may be different. Therefore, depending on the type of PV module (110), the output voltage (V) of the PV module (110) applied to the device (120) pv ) may have different scopes.

[0069] When a diode (D) is included in the device (120), since the forward voltage of the diode (D) is constant, the performing device (120) can operate at the required safety voltage (V) regardless of the manufacturer or product characteristics of the PV module (110). safety voltage ) can be output stably.

[0070] As described above, since the electronic circuit (1212) is a circuit implemented using the simple semiconductor characteristics of a diode, the safety voltage level can be easily adjusted and set according to the forward characteristics of the diode (D).

[0071] In addition, since the voltage applied to the diode (D) has a constant value, a safe voltage can be easily output regardless of the type of PV module (110).

[0072] In addition, a safe voltage can be output using simple semiconductor characteristics without the complex process of setting the safe voltage through control of a PWM controller.

[0073] Additionally, the level of required safety voltage can be designed to match the simple diode forward characteristics, allowing for agile circuit changes according to the safety requirements of the user.

[0074] FIG. 5 is a diagram illustrating an example of how a device performing a safety function according to one embodiment operates.

[0075] At step S10, the processor (122) determines whether a transition to safe mode is required. In other words, the processor (122) determines whether a predetermined condition is satisfied.

[0076] For example, the processor (122) can monitor the status of the system (1) to identify whether a transition to a safe mode is required depending on whether an abnormal situation occurs. Here, the safe mode can include an RSD mode.

[0077] Alternatively, the processor (122) may identify that a transition to safe mode is required when receiving a shutdown signal from the inverter.

[0078] Additionally, the device (120) can be used to check for a failure in the MLPE. In this case, the system (1) can be switched to a safe mode through the operation of an administrator, such as an installer, and the failure in the MLPE can be checked through the safe voltage output from the device (120).

[0079] When the processor (122) identifies that the system (1) needs to switch to safe mode (Yes in S10), the processor (122) inputs an off signal to the switching element (SW).

[0080] As the switching element (SW) is turned off, the electronic circuit (1211) outputs a safety voltage across the second resistor (R2), or the electronic circuit (1212) outputs a safety voltage across both terminals of the second resistor (R2) and the diode (D).

[0081] If the processor (122) determines that the system (1) does not require transition to safe mode (No in S10), the algorithm terminates. In other words, if the system (1) operates normally, the switching elements (SW) of the electronic circuits (1211, 1212) can be turned on.

[0082] When the switching element (SW) is turned on, the switching element (SW) has an ON resistance (RDS(ON)), which is the resistance between the drain and the source.

[0083] Since the first resistor (R1) and the switching element (SW) are connected in parallel, the composite resistance has a value smaller than the ON resistance (RDS(ON)), so the output voltage of the PV module (110) is applied directly to both terminals of the second resistor (R2). That is, when the switching element (SW) operates in the ON position, the safety function performing device (120) does not affect the system (1).

[0084] According to the above, the device (120) can be operated stably without causing a burden such as power loss to the system (1).

[0085] 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.).

[0086] 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. An electronic circuit including a switching element, a first resistor, and a second resistor; and A device for performing a safety function, comprising a processor that controls the operation of the electronic circuit so that a first voltage applied to the electronic circuit is converted to a second voltage when a predetermined condition is satisfied.

2. In paragraph 1, The above processor, A device that converts the first voltage into the second voltage by turning off the switching element.

3. In paragraph 1, A device wherein the first voltage includes an output voltage of at least one PV (photovoltaic) module included in a solar power generation system.

4. In paragraph 1, The above switching element and the first resistor are connected in parallel, A device in which the second resistor is connected in series with the parallel connection of the switching element and the first resistor.

5. In paragraph 1, The electronic circuit further includes a diode connected in series with the second resistor, The above processor, By turning off the switching element, the first voltage is converted into the second voltage, A device wherein the second voltage includes voltages across the two terminals of the second resistor and the diode.

6. In paragraph 1, The above processor, A device that monitors the status of the above solar power generation system and identifies whether the above-mentioned conditions are satisfied.

7. In paragraph 1, The above-mentioned conditions are a device that includes conditions that require the solar power generation system to switch to a safe mode.

8. In paragraph 1, A device in which the resistance value of the first resistor is greater than or equal to the resistance value of the second resistor.

9. Multiple PV (Photovoltaic) modules; and A device connected to each of the plurality of PV modules; The above device, An electronic circuit comprising a switching element, a first resistor, and a second resistor; and A solar power generation system comprising a processor that controls the electronic circuit so that a first voltage applied to the electronic circuit is converted into a second voltage according to the state of the solar power generation system.

10. In paragraph 9, The above processor, A system that converts the first voltage into the second voltage by turning off the switching element.

11. In paragraph 9, A system wherein the first voltage includes an output voltage of at least one PV (photovoltaic) module included in a solar power generation system.

12. In paragraph 9, The above switching element and the first resistor are connected in parallel, A system wherein the second resistor is connected in series with the parallel connection of the switching element and the first resistor.

13. In paragraph 9, The electronic circuit further includes a diode connected in series with the second resistor, The above processor, By turning off the switching element, the first voltage is converted into the second voltage, A system wherein the second voltage includes voltages across the second resistor and the diode.

14. In paragraph 9, The above processor, A system that monitors the status of the above solar power generation system and identifies whether the above-mentioned conditions are satisfied.

15. In paragraph 9, A system in which the resistance value of the first resistor is greater than or equal to the resistance value of the second resistor.

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