Control device, intelligent photovoltaic system and control method therefor

Abstract

A control device, an intelligent photovoltaic system and a control method therefor. The control device (4) comprises: a microcontroller unit, a driver, a square-wave generator circuit, a resonant cavity circuit and a current sensor coupling circuit, wherein the microcontroller unit outputs a square wave to the driver, so that the driver performs amplitude and current amplification on the waveform of the square wave and then transmits the square wave to the square-wave generator circuit; the square-wave generator circuit sends the square wave to the resonant cavity circuit, and the square wave is then input into a filter circuit; and the square wave is filtered by the filter circuit and then coupled to a power line between each quick turn-off unit and an inverter by means of the current sensor coupling circuit, so as to turn on or off each quick turn-off unit.

Description

A control device, intelligent photovoltaic system and control method thereof

[0001] Related applications

[0002] This application claims priority to Chinese patent application number 2023110389532, filed on August 17, 2023, entitled “A control device, an intelligent photovoltaic system and a control method thereof,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application belongs to the technical field of intelligent photovoltaic systems, and specifically relates to a control device, an intelligent photovoltaic system and a control method thereof. Background Art

[0004] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0005] Figure 1 shows a traditional photovoltaic module protection circuit, which uses diodes connected in parallel to photovoltaic modules to protect the modules. Under certain conditions, some modules in the photovoltaic system may be blocked by surrounding objects, causing local shadows and hot spots on the modules. This device is used to protect the modules, but it has a slow response speed and is prone to safety accidents.

[0006] At the same time, conventional module circuit breakers need to be networked with control equipment. If the module circuit breakers and control equipment are networked wirelessly, the stability of the wireless signal cannot be guaranteed. If the module circuit breakers and control equipment are networked through a separate control line, the signal transmission rate of the control line is slower than that of the power line. At the same time, the cost of the control line is also higher, and there is a certain delay in early warning, which will affect the rescue speed of abnormal accidents in the power station.

[0007] Therefore, there is an urgent need to develop a new control device, an intelligent photovoltaic system and a control method thereof to solve the above problems.

[0008] Summary of the Invention

[0009] According to various embodiments of the present application, a control device, an intelligent photovoltaic system, and a control method thereof are provided.

[0010] A control device comprises: a microcontroller unit, a driver, a square wave generator circuit, a resonant cavity circuit, and a current sensor coupling circuit; wherein the current sensor coupling circuit is coupled to the power line between each fast disconnect and the inverter; the microcontroller unit outputs a square wave to the driver, so that the driver amplifies the amplitude and current of the square wave waveform and transmits it to the square wave generator circuit; the square wave generator circuit sends the square wave to the resonant cavity circuit, so that the resonant cavity circuit converts the square wave into a resonant sine wave and then inputs it into the current sensor coupling circuit; the current sensor coupling circuit couples the resonant sine wave to the power line between each fast disconnect and the inverter to shut down or open each fast disconnect.

[0011] Furthermore, the control device also includes: a filtering circuit; the filtering circuit connects the resonant cavity circuit and the current sensor coupling circuit; the resonant cavity circuit changes the square wave into a resonant sine wave and inputs it into the filtering circuit, and the resonant sine wave is filtered by the filtering circuit and then output to the current sensor coupling circuit.

[0012] Furthermore, the microcontroller unit generates a corresponding square wave.

[0013] Furthermore, the square wave generator circuit includes: a P-channel MOS transistor and an N-channel MOS transistor; the P-channel MOS transistor and the N-channel MOS transistor are connected in series to form a half-bridge square wave generator; the square wave after the amplitude and current are amplified by the driver is input into the P-channel MOS transistor and the N-channel MOS transistor to generate a corresponding square wave and then sent to the resonant cavity circuit.

[0014] Furthermore, the resonant cavity circuit includes: a series resonant inductor and a series resonant capacitor; the series resonant inductor and the series resonant capacitor are connected in series to form a resonant cavity circuit; the resonant cavity circuit generates a resonant sine wave with symmetrical amplitude through Fourier transformation of the square wave generated by the square wave generator circuit and sends it to the filter circuit.

[0015] Furthermore, the filtering circuit includes: a first filtering capacitor and a second filtering capacitor; the resonant sine wave is filtered by the first filtering capacitor and the second filtering capacitor and then sent to the current sensor coupling circuit.

[0016] Furthermore, the current sensor coupling circuit includes: a current sensor; the current sensor couples and transmits the resonant sine wave to the power line between each fast shutdown device and the inverter.

[0017] The present application provides an intelligent photovoltaic system, comprising: a control device as described above and a plurality of photovoltaic modules; wherein the control device is coupled to a power line between each photovoltaic module and an inverter; the control device is coupled to send a control signal to the power line between each photovoltaic module and the inverter to shut down or open a corresponding fast disconnector.

[0018] The present application also provides a method for controlling a fast shutdown device, which comprises: using the control device as described above to control each fast shutdown device.

[0019] Furthermore, when the control device is coupled to the power line between each photovoltaic module and the inverter, the control device is coupled to send a control signal to the power line between each photovoltaic module and the inverter to turn off or turn on the corresponding fast disconnector.

[0020] Other features and advantages of the present application will be set forth in the following description and, in part, will become apparent from the description or may be understood by practicing the present application.

[0021] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] FIG1 is a schematic diagram of the prior art;

[0024] FIG2 is a circuit diagram of the control device of the present application;

[0025] FIG3 is a schematic diagram of the control device of the present application when it is installed in the power line between each fast shutdown device and the inverter;

[0026] FIG4 is an output waveform diagram of the microcontroller unit of the present application;

[0027] FIG5 is an output waveform diagram of the driver of the present application;

[0028] FIG6 is an output waveform diagram of the square wave generator circuit of the present application;

[0029] FIG7 is an output waveform diagram of the resonant cavity circuit of the present application;

[0030] FIG8 is a comparison diagram of the output waveform of the square wave generator circuit and the output waveform of the filter circuit of the present application;

[0031] FIG9 is a schematic diagram of the smart photovoltaic system of the present application.

[0032] Explanation of the accompanying symbols: 1. Inverter; 2. Photovoltaic module; 3. Fast shutdown device; 4. Control device; Q1. P-channel MOS transistor; Q2. N-channel MOS transistor; L1. Series resonant inductor; CA1. Series resonant capacitor; CA2. First filter capacitor; CA3. Second filter capacitor; TR1. Current sensor. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] To make the implementation cases, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] Example 1

[0036] In some embodiments, as shown in Figures 2 to 8, a control device 4 is provided, which includes: a microcontroller unit, a driver, a square wave generator circuit, a resonant cavity circuit and a current sensor coupling circuit; wherein the current sensor coupling circuit is coupled to the power line between each fast shut-off device 3 and the inverter 1; the microcontroller unit outputs a square wave to the driver, so that the driver amplifies the waveform of the square wave in amplitude and current and transmits it to the square wave generator circuit; the square wave generator circuit sends the square wave to the resonant cavity circuit, so that the resonant cavity circuit changes the square wave into a resonant sine wave and then inputs it into the current sensor coupling circuit, and the current sensor coupling circuit couples the resonant sine wave to the power line between each fast shut-off device 3 and the inverter 1 to turn off or turn on each fast shut-off device 3.

[0037] In some embodiments, the microcontroller unit adopts an MCU controller.

[0038] In some embodiments, as shown in FIG2 , a microcontroller unit and a driver are connected to the Vin terminal, the microcontroller unit sends a square wave signal to the Vin terminal through the driver, and the microcontroller unit outputs an output waveform diagram; illustratively, the output waveform diagram is shown in FIG4 .

[0039] In some embodiments, this embodiment can achieve coupling access to the power line by setting up a current sensor coupling circuit, and uses power carrier wireless communication to achieve rapid switching on and off of any fast disconnector 3, saving material costs and labor maintenance costs, and compared with traditional component protection devices, it has faster shutdown and better protection effect.

[0040] In some embodiments, the control device 4 further includes: a filtering circuit; the filtering circuit connects the resonant cavity circuit and the current sensor coupling circuit; the resonant cavity circuit changes the square wave into a resonant sine wave and inputs it into the filtering circuit, and the resonant sine wave is filtered by the filtering circuit and then output to the current sensor coupling circuit.

[0041] In some embodiments, the microcontroller unit generates the corresponding square wave.

[0042] In some embodiments, the microcontroller unit can monitor the status of the photovoltaic module 2 in real time, promptly detect problems and faults of the photovoltaic module 2, further improve the intelligence and reliability of the photovoltaic module 2, and can quickly respond to abnormal situations, and quickly shut down the fast shutdown device 3 through the power carrier signal. Therefore, it is very suitable for photovoltaic power station power generation systems, and can effectively solve fires caused by hot spots of photovoltaic modules 2, string loss of control, cable damage, etc., or quickly reduce the string voltage during maintenance, to ensure the safety of rescue or operation and maintenance personnel.

[0043] In some embodiments, the microcontroller unit generates a specific pattern of codes, which will generate square waves with two carrier frequencies of FM=131.25 kHz and FS=143.75 kHz.

[0044] In some embodiments, the square wave generator circuit includes: a P-channel MOS transistor Q1 and an N-channel MOS transistor Q2; the P-channel MOS transistor Q1 and the N-channel MOS transistor Q2 are connected in series to form a half-bridge square wave generator; the square wave after the amplitude and current are amplified by the driver is input into the P-channel MOS transistor Q1 and the N-channel MOS transistor Q2 to generate a corresponding square wave and then sent to the resonant cavity circuit.

[0045] In some embodiments, the output waveform of the driver is shown in FIG5 . After the square wave output by the driver is processed by the P-channel MOS transistor Q1 and the N-channel MOS transistor Q2 , the output waveform of the square wave generator circuit is finally output as shown in FIG6 .

[0046] In some embodiments, as shown in FIG2 , the resonant cavity circuit includes: a series resonant inductor L1 and a series resonant capacitor CA1; the series resonant inductor L1 and the series resonant capacitor CA1 are connected in series to form a resonant cavity circuit; the resonant cavity circuit generates a resonant sine wave with symmetrical amplitude through Fourier transformation of the square wave generated by the square wave generator circuit and sends it to the filter circuit.

[0047] In some embodiments, the output waveform of the resonant cavity circuit is shown in FIG7 .

[0048] In some embodiments, the square wave in FIG8 represents the square wave waveform at the midpoint P of the half-bridge in a half-bridge square wave generator. The sinusoidal wave waveform represents the frequency-selective resonant waveform at point Q. The voltage between point P and ground represents the input voltage within the resonant cavity. The actual input voltage waveform within the resonant cavity is a square wave. Let the input power supply voltage of the resonant cavity be Vin. The Vin voltage signal resonates through the series resonant capacitor CA1 and the series resonant inductor L1. The series resonant capacitor CA1 can only pass the AC component but not the DC component. The DC component can only be stored in the series resonant capacitor CA1. When the P-channel MOS transistor Q1 is on and the N-channel MOS transistor Q2 is off, the actual voltage applied to the resonant cavity is only Vin / 2. When the N-channel MOS transistor Q2 is on and the P-channel MOS transistor Q1 is off, the actual voltage source applied to the resonant cavity is the series resonant capacitor CA1. The energy in the series resonant capacitor CA1 powers the subsequent circuits.

[0049] In some embodiments, the series resonant inductor L1 and the series resonant capacitor CA1 are selected based on the parameters of two frequency points (FM=131.25kHz, FS=143.75kHz) to achieve the purpose of resonant frequency-selective carrier coupling communication.

[0050] In some embodiments, the filtering circuit includes: a first filtering capacitor CA2 and a second filtering capacitor CA3; the resonant sine wave is filtered by the first filtering capacitor CA2 and the second filtering capacitor CA3 and then fed into the current sensor coupling circuit.

[0051] In some embodiments, as shown in FIG. 2 , the current sensor coupling circuit includes: a current sensor TR1 ; the current sensor TR1 couples and transmits the resonant sine wave to the power lines of each fast disconnector 3 and the inverter 1 .

[0052] In some embodiments, signal transmission is implemented in a power carrier manner through the current sensor TR1, which can reduce the installation cost of the photovoltaic assembly 2 and also facilitate subsequent maintenance by operation and maintenance personnel.

[0053] In some embodiments, the sinusoidal waveform in FIG8 is a resonant sine wave with symmetrical amplitude generated by Fourier transform of a square wave in a resonant cavity. The resonant sine wave is filtered by the first filter capacitor CA2 and the second filter capacitor CA3, and then coupled to the power line through the current sensor TR1. After receiving the coupled signal, the fast circuit breaker 3 performs signal processing such as filtering and amplification to control the shutdown or opening operation of the fast circuit breaker 3.

[0054] How it works

[0055] After the PWM wave generated by the microcontroller unit is sent to the driver and the half-bridge square wave generator, the resonant cavity circuit generates a resonant sine wave of the required specific frequency from the square wave generated by the half-bridge square wave generator. The generated resonant sine wave is then filtered by the filter circuit and then generated into a resonant sine wave of a specific frequency through the current sensor coupling circuit. The resonant sine wave is transmitted to the fast shutdown device 3 through coupling to control the on and off of the fast shutdown device 3.

[0056] Example 2

[0057] Based on Example 1, as shown in Figures 2 to 9, this embodiment provides an intelligent photovoltaic system, which includes: a control device 4 and a plurality of photovoltaic components 2 as provided in Example 1; wherein the control device 4 is coupled to the power line between each photovoltaic component 2 and the inverter 1; the control device 4 is coupled to send a control signal to the power line between each photovoltaic component 2 and the inverter 1 to turn off or turn on the corresponding fast disconnector 3.

[0058] In some embodiments, one photovoltaic assembly 2 and one rapid shutoff device 3 form a group, and each rapid shutoff device 3 can be individually controlled by the control device 4 . At the same time, each rapid shutoff device 3 controls the on and off of the corresponding photovoltaic assembly 2 .

[0059] Example 3

[0060] On the basis of the above embodiment, this embodiment provides a method for controlling a fast disconnector 3 , which includes: using the control device 4 provided in embodiment 1 to control each fast disconnector 3 .

[0061] In some embodiments, when the control device 4 is coupled to the power line between each photovoltaic component 2 and the inverter 1, the control device 4 is coupled to send a control signal to the power line between each photovoltaic component 2 and the inverter 1 to turn off or turn on the corresponding fast disconnector 3.

[0062] To sum up, the present application can realize coupling access to the power line by setting up a current sensor coupling circuit, and realizes rapid switching on and off of any rapid disconnector 3 by adopting power carrier wireless communication, saving material costs and labor maintenance costs, and compared with traditional component protection devices, it can shut down faster and have better protection effect.

[0063] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0064] In the description of the embodiments of this application, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0065] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0067] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0068] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0069] Based on the above-described ideal embodiments of this application, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

[0070] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A control device, comprising: a microcontroller unit, a driver, a square wave generator circuit, a resonant cavity circuit, and a current sensor coupling circuit; The current sensor coupling circuit is coupled to the power line between each fast shut-off device and the inverter; The microcontroller unit outputs a square wave to the driver, so that the driver amplifies the waveform of the square wave in amplitude and current and transmits it to the square wave generator circuit; as well as The square wave generator circuit sends the square wave to the resonant cavity circuit, so that the resonant cavity circuit changes the square wave into a resonant sine wave and then inputs it into the current sensor coupling circuit. The current sensor coupling circuit couples the resonant sine wave to the power line between each fast switch and the inverter to turn off or turn on each fast switch.

2. The control device according to claim 1, wherein The control device also includes: Filter circuit; The filter circuit connects the resonant cavity circuit and the current sensor coupling circuit; The resonant cavity circuit changes the square wave into a resonant sine wave and then inputs it into the filter circuit. The filter circuit filters the resonant sine wave and then outputs it to the current sensor coupling circuit.

3. The control device according to claim 1, wherein The microcontroller unit generates a corresponding square wave.

4. The control device according to claim 1, wherein The square wave generator circuit comprises: P-channel MOS tube and N-channel MOS tube; The P-channel MOS tube and the N-channel MOS tube are connected in series to form a half-bridge square wave generator; The square wave whose amplitude and current are amplified by the driver is input into the P-channel MOS tube and the N-channel MOS tube to generate the corresponding square wave and then sent into the resonant cavity circuit.

5. The control device according to claim 1, wherein The resonant cavity circuit comprises: Series resonant inductor and series resonant capacitor; The series resonant inductor and the series resonant capacitor are connected in series to form a resonant cavity circuit; The resonant cavity circuit transforms the square wave generated by the square wave generator circuit into a resonant sine wave with symmetrical amplitude through Fourier transformation and sends it to the filter circuit.

6. The control device according to claim 5, wherein the series resonant inductor and the series resonant capacitor are selected according to the parameters of the two frequency points.

7. The control device according to claim 1, wherein The filtering circuit comprises: a first filter capacitor and a second filter capacitor; The resonant sine wave is filtered by the first filter capacitor and the second filter capacitor and then sent to the current sensor coupling circuit.

8. The control device according to claim 1, wherein The current sensor coupling circuit comprises: Current sensor; The current sensor couples the resonant sine wave into the power line between each fast switch and the inverter.

9. The control device as claimed in claim 8, wherein the signal transmission is implemented by means of a power carrier through a current sensor.

10. The control device as claimed in claim 1, wherein the microcontroller unit adopts an MCU controller.

11. The control device of claim 1, wherein the microcontroller unit is capable of monitoring the status of the photovoltaic assembly in real time.

12. An intelligent photovoltaic system, comprising: A control device and a plurality of photovoltaic modules as claimed in any one of claims 1 to 11; The control device is coupled to the power line between each photovoltaic assembly and the inverter; and The control device is coupled to send a control signal to the power line between each photovoltaic module and the inverter to turn off or turn on the corresponding fast disconnector.

13. The control device as claimed in claim 12, wherein one photovoltaic module and one rapid switch form a group, each rapid switch can be controlled by the control device individually, and each rapid switch controls the on and off of the photovoltaic module corresponding thereto.

14. A method for controlling a fast shut-off device, comprising: The control device according to any one of claims 1 to 11 is used to control each rapid shutdown device.

15. The method for controlling a fast shutdown device according to claim 14, wherein When the control device is coupled to the power line between each photovoltaic component and the inverter, the control device is coupled to send a control signal to the power line between each photovoltaic component and the inverter to turn off or turn on the corresponding fast disconnector.

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