Conversion device, photovoltaic system and control method

Abstract

The invention discloses a conversion device, a photovoltaic system and a control method. The conversion device provided by the invention can reversely transmit the voltage of the external direct-current power supply to the photovoltaic cell module under the first control signal, so that the photovoltaic cell module emits light for detection; and under the second control signal, the power generation voltage of the photovoltaic battery assembly is output at the maximum power, so that an inverter of a traditional detection circuit is omitted, and the cost of a photovoltaic circuit is further saved.

Description

Conversion device, photovoltaic system and control method Technical Field

[0001] The present application relates to the field of photovoltaic cell technology, and in particular to a conversion device, a photovoltaic system and a control method. Background Art

[0002] At present, new energy power generation methods such as photovoltaic power generation and wind power generation are emerging. Photovoltaic cell modules play a vital role in photovoltaic power generation. However, photovoltaic cell modules are prone to failure. Therefore, it is often necessary to perform fault detection on photovoltaic cell modules.

[0003] Regarding the method of checking photovoltaic cell module faults, the current conventional technology is to rectify the AC power from the power grid or AC energy storage device into DC power through an inverter, power the photovoltaic cell module, causing the photovoltaic cell module to emit light, and then use a mobile image acquisition device to capture images and send them to an EL (Electroluminescent) detection device (electroluminescent detection device) for fault detection.

[0004] However, the above method requires the photovoltaic cell modules to be powered by an inverter after rectification, which incurs the cost of the inverter and results in excessively high costs. In addition, the photovoltaic cell modules cannot be tested without an inverter.

[0005] Summary of the Invention

[0006] In view of the above problems, the present application provides a conversion device, a photovoltaic system and a control method, which can solve the current problem of high inverter cost and environmental limitations that only inverters can be used, which is caused by the need to use an inverter to rectify AC to DC and then power photovoltaic cell components to perform fault detection on photovoltaic cells.

[0007] In a first aspect, the present application provides a conversion device for connecting an energy storage device and a photovoltaic cell assembly; the conversion device is used to convert the supply voltage output by the energy storage power supply device into voltage in response to a first control signal and then supply power to the photovoltaic cell assembly; and to track the maximum output power of the photovoltaic cell assembly in response to a second control signal, and output the electric energy generated by the photovoltaic cell assembly at the maximum output power.

[0008] The conversion device designed as above can realize the reverse transmission of the voltage of the external DC power supply to the photovoltaic cell assembly under the first control signal, so that the photovoltaic cell assembly emits light for detection; and can realize the output of the photovoltaic cell assembly power generation voltage at maximum power under the second control signal. Thus, the traditional MPPT function and the reverse power supply to the photovoltaic cell assembly can be realized through the conversion device, thereby omitting the traditional detection circuit inverter and saving costs.

[0009] In an optional embodiment of the first aspect, the conversion device is an MPPT control device, comprising a first controllable semiconductor power device; the first controllable semiconductor power device is configured to, in response to a first control signal, conduct a path between the energy storage device and the photovoltaic cell assembly, thereby converting a supply voltage of the energy storage device into a first supply voltage and transmitting it to the photovoltaic cell assembly. This embodiment improves upon a conventional MPPT control device, enabling it to perform not only maximum power point tracking but also reverse power to the photovoltaic cell assembly, thereby omitting the conventional detection circuit inverter and saving costs.

[0010] In an optional embodiment of the first aspect, the MPPT control device further includes a first current acquisition module, which is connected to the passage; and / or the MPPT control device further includes a first voltage acquisition module, which is connected to the passage.

[0011] In an optional implementation of the first aspect, the MPPT control device includes a first current acquisition module, which is used to perform current detection on the first supply voltage to obtain a first detection current; the MPPT control device is also used to determine whether the photovoltaic cell assembly is faulty based on the first detection current.

[0012] In an optional embodiment of the first aspect, the MPPT control device includes a first voltage acquisition module configured to detect a first supply voltage to obtain a first detection voltage. The MPPT control device is further configured to determine whether the photovoltaic cell assembly is faulty based on the first detection voltage. The MPPT control device designed in this embodiment can determine whether the photovoltaic cell assembly is faulty based on the first detection voltage detected by the first voltage acquisition module, thereby increasing the number of methods for determining photovoltaic cell assembly faults and improving the reliability of the photovoltaic cell assembly.

[0013] In a second aspect, the present application provides a photovoltaic system, characterized in that the photovoltaic circuit includes a conversion device, a photovoltaic cell assembly, and an energy storage and power supply device described in any optional embodiment of the first aspect, and the photovoltaic cell assembly is electrically connected to the energy storage and power supply device through the conversion device.

[0014] In the technical solution of the embodiment of the present application, the conversion device can realize the reverse transmission of the voltage of the external DC power supply to the photovoltaic cell assembly under the first control signal, so that the photovoltaic cell assembly emits light for detection; and can realize the output of the power generation voltage of the photovoltaic cell assembly at maximum power under the second control signal, thereby omitting the inverter of the traditional detection circuit and saving the cost of the photovoltaic system.

[0015] In an optional embodiment of the second aspect, the photovoltaic circuit further includes a controller; the controller is electrically connected to each of the conversion devices; and the controller is configured to send a first control signal to the conversion devices. In this embodiment, by having the controller send the first control signal, the timing of sending the first control signal is controllable, thereby enabling controllable fault detection in the photovoltaic system.

[0016] In an optional embodiment of the second aspect, the energy storage device includes an energy storage battery and a DC voltage converter; the energy storage battery is electrically connected to the conversion device via the DC voltage converter; the controller is electrically connected to the DC voltage converter; the controller is further configured to send a third control signal to the DC voltage converter; the DC voltage converter is configured to boost the output voltage of the energy storage battery to a second supply voltage in response to the third control signal to obtain a supply voltage for the energy storage device; and the conversion device is specifically configured to step down the supply voltage of the energy storage power supply device to a first supply voltage. In this embodiment, DC power is supplied by the energy storage battery, and then the DC voltage converter and the conversion device perform voltage conversion so that the first supply voltage ultimately output to the photovoltaic cell assembly meets the voltage requirements of the photovoltaic cell assembly.

[0017] In an optional embodiment of the second aspect, the DC voltage converter includes a second controllable semiconductor power device, a second current acquisition module, and a second voltage acquisition module; the energy storage battery is electrically connected to the second current acquisition module via the second voltage acquisition module, and the second current acquisition module is electrically connected to the conversion device via the second controllable semiconductor power device; the second voltage acquisition module is used to acquire the output voltage of the energy storage battery; the second current acquisition module is used to acquire the output current corresponding to the output voltage of the energy storage battery; and the second controllable semiconductor power device is used to boost the output voltage of the energy storage battery to a second supply voltage in response to a third control signal.

[0018] In an optional embodiment of the second aspect, the controller is further configured to, after sending the first control signal, collect a first detection voltage and / or a first detection current, and determine whether the photovoltaic cell assembly is faulty based on the first detection voltage and / or the first detection current. In addition to conventional photovoltaic cell assembly fault detection by collecting images, this embodiment also uses the controller to detect whether the current and voltage of the photovoltaic cell assembly during reverse power supply are as expected based on the first detection voltage and / or the first detection current to determine whether the photovoltaic cell assembly is faulty, thereby ensuring the reliability of photovoltaic cell assembly fault detection through multiple means.

[0019] In an optional embodiment of the second aspect, the photovoltaic system further includes an AC voltage conversion device; the photovoltaic cell assembly is electrically connected to the AC voltage conversion device via the conversion device, and the AC voltage conversion device is configured to be electrically connected to a power grid; the AC voltage conversion device is configured to convert a received voltage corresponding to the maximum output power of the photovoltaic cell assembly into a corresponding AC output voltage, and transmit the AC output voltage to the power grid. The conversion device of this embodiment can also transmit the voltage generated by the photovoltaic cell assembly to the AC voltage conversion device, thereby outputting the electrical energy generated by the photovoltaic cell assembly to the power grid.

[0020] In an optional embodiment of the second aspect, the photovoltaic system also includes a fault detection device; the fault detection device is used to collect an image of the photovoltaic cell assembly after the conversion device converts the supply voltage output by the energy storage device according to the first control signal and supplies power to the photovoltaic cell assembly, and detect whether the photovoltaic cell assembly is faulty based on the collected image.

[0021] In a third aspect, the present application provides a control method for controlling a conversion device, which is used to connect an energy storage device and a photovoltaic cell assembly; the method includes: sending a first control signal to the conversion device, so that the conversion device converts the supply voltage output by the energy storage power supply device in response to the first control signal and then supplies power to the photovoltaic cell assembly; and sending a second control signal to the conversion device, so that the conversion device tracks the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmits the electric energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0022] In the technical solution of the embodiment of the present application, this solution can transmit different control signals to the conversion device in different scenarios, so that the conversion device converts the power supply voltage output by the energy storage power supply device under the first control signal and then supplies power to the photovoltaic cell assembly, and outputs the electric energy generated by the photovoltaic cell assembly at the maximum output power under the second control signal. In this way, the conversion device can realize the functions of the traditional MPPT control device and the two functions of reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving costs.

[0023] In an optional embodiment of the third aspect, before sending the first control signal to the conversion device, the method further includes: receiving a self-test result of the energy storage device, and sending the first modulated signal to the conversion device after the self-test result indicates no faults. In this embodiment, sending the first control signal to the conversion device is performed only after the self-test result indicates no faults, thereby avoiding circuit failures caused by faults in the energy storage device.

[0024] In an optional embodiment of the third aspect, the conversion device includes a first controllable semiconductor power device and a first current acquisition module. After sending a first control signal to the conversion device, the method further includes: obtaining a first detection current; wherein the first detection current is obtained by collecting the current corresponding to the first power supply voltage by the first current acquisition module, and the first power supply voltage is generated by reducing the power supply voltage of the energy storage device by the first controllable semiconductor power device; and determining whether the photovoltaic cell assembly is faulty based on the first detection current.

[0025] In an optional embodiment of the third aspect, determining whether the photovoltaic cell assembly is faulty is based on the first detection current, including: judging whether a first deviation value between the first detection current and the target current value is greater than a first preset threshold value; if the first deviation value between the first detection current and the target current value is greater than the first preset threshold value, determining that the photovoltaic cell assembly is faulty.

[0026] In an optional embodiment of the third aspect, the conversion device includes a first controllable semiconductor power device and a first voltage acquisition module. After sending a first control signal to the conversion device, the method further includes: obtaining a first detection voltage; wherein the first detection voltage is obtained by acquiring a voltage corresponding to a first power supply voltage by the first voltage acquisition module, and the first power supply voltage is generated by reducing the power supply voltage of the energy storage device by the first controllable semiconductor power device; and determining whether the photovoltaic cell assembly is faulty based on the first detection voltage.

[0027] In an optional embodiment of the third aspect, determining whether the photovoltaic cell assembly is faulty based on the first detection voltage includes: determining whether a second deviation between the first detection voltage and a target voltage value is greater than a second preset threshold; and determining that the photovoltaic cell assembly is faulty if the second deviation between the first detection voltage and the target voltage value is greater than the second preset threshold. The above-described embodiment, this solution, detects whether the current and voltage of the photovoltaic cell assembly during reverse power supply are as expected based on the first detection voltage and / or the first detection current to determine whether the photovoltaic cell assembly is faulty, thereby ensuring the reliability of fault detection for the photovoltaic cell assembly through multiple means.

[0028] In an optional embodiment of the third aspect, the energy storage device includes an energy storage battery and a DC voltage converter, and the conversion device is electrically connected to the energy storage battery through the DC voltage converter; the method also includes: sending a third control signal to the DC voltage converter, so that the DC voltage converter boosts the output voltage of the energy storage battery to a second supply voltage in response to the third control signal, thereby obtaining the supply voltage of the energy storage device.

[0029] In a fourth aspect, the present application provides a control device for controlling a conversion device, which is used to connect an energy storage power supply device and a photovoltaic cell assembly; the device includes: a sending module, which sends a first control signal to the conversion device, so that the conversion device converts the supply voltage output by the energy storage device according to the first control signal and then supplies power to the photovoltaic cell assembly; and sends a second control signal to the conversion device, so that the conversion device tracks the maximum output power of the photovoltaic cell assembly according to the second control signal, and transmits the electric energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0030] The control device designed above can transmit different control signals to the conversion device in different scenarios, so that the conversion device converts the power supply voltage output by the energy storage device under the first control signal and then supplies power to the photovoltaic cell assembly, and outputs the electric energy generated by the photovoltaic cell assembly at the maximum output power under the second control signal. In this way, the conversion device can realize the functions of the traditional MPPT control device and the two functions of reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving costs.

[0031] In a fifth aspect, the present application provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it executes the method in the third aspect or any optional implementation of the third aspect.

[0032] In a sixth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method in the third aspect or any optional implementation of the third aspect is executed.

[0033] In a seventh aspect, the present application provides a computer program product, which, when running on a computer, enables the computer to execute the method in the third aspect or any optional implementation of the third aspect.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0036] FIG1 is a first structural schematic diagram of a conversion device provided in this embodiment;

[0037] FIG2 is a second structural schematic diagram of the conversion device provided in this embodiment;

[0038] FIG3 is a third structural diagram of the conversion device provided in this embodiment;

[0039] FIG4 is a first structural diagram of a photovoltaic circuit provided in this embodiment;

[0040] FIG5 is a second structural diagram of a photovoltaic circuit provided in this embodiment;

[0041] FIG6 is a third structural diagram of the photovoltaic circuit provided in this embodiment;

[0042] FIG7 is a fourth structural diagram of a photovoltaic circuit provided in this embodiment;

[0043] FIG8 is a fifth structural diagram of a photovoltaic circuit provided in this embodiment;

[0044] FIG9 is a schematic diagram of a first flow chart of the control method provided in this embodiment;

[0045] FIG10 is a schematic diagram of a second flow chart of the control method provided in this embodiment;

[0046] FIG11 is a schematic diagram of a third flow chart of the control method provided in this embodiment;

[0047] FIG12 is a schematic structural diagram of a control device provided in this embodiment;

[0048] FIG13 is a schematic structural diagram of an electronic device provided in this embodiment.

[0049] The accompanying drawings in the specific implementation manner are as follows:

[0050] 10-conversion device; 110-first controllable semiconductor power device; 120-first current acquisition module; 130-first voltage acquisition module; A1-energy storage device; A10-energy storage battery; A11-DC voltage converter; A110-second controllable semiconductor power device; A111-second current acquisition module; A112-second voltage acquisition module; PD-photovoltaic cell assembly; Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8-controllable semiconductor power devices; 20-controller; 30-AC voltage conversion device; 1200-sending module; 1210-acquisition module; 1220-determination module; 13-electronic device; 1301-processor; 1302-memory; 1303-communication bus. DETAILED DESCRIPTION

[0051] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0053] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0054] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0056] With the rise of renewable energy sources such as photovoltaic and wind power, photovoltaic modules play a crucial role in this sector. However, failures are inevitable, and therefore, fault detection is often necessary. Conventional technology for detecting PV module faults involves converting AC power from the grid or AC energy storage devices into DC power through an inverter. This power is then supplied to the PV module, causing it to emit light. A mobile image acquisition device then captures images and transmits them to an EL detection device for fault detection.

[0057] The inventors have noticed that this method of converting AC to DC to power the photovoltaic cell assembly for light detection requires an inverter for power conversion, which incurs the cost of the inverter and leads to excessively high costs; and the photovoltaic cell assembly cannot be detected without an inverter.

[0058] Maximum Power Point Tracking (MPPT) solar control devices typically monitor the voltage generated by photovoltaic modules in real time and track the maximum voltage and current (V1) to ensure the system charges the battery or grid at maximum power output. Therefore, MPPT and photovoltaic modules are a common configuration, meaning that photovoltaic modules are typically used in conjunction with MPPT.

[0059] In response to the above problems, the inventors have researched and designed a conversion device, a photovoltaic system and a control method, so that the designed conversion device can, under a first control signal, reversely transmit the voltage of an external DC power supply to the photovoltaic cell assembly, so that the photovoltaic cell assembly emits light for detection; and under a second control signal, output the generated voltage of the photovoltaic cell assembly at maximum power, thereby including two functions through a single device design, thereby omitting the traditional detection circuit inverter and saving costs.

[0060] Specifically, the present application provides a conversion device, as shown in FIG1 , wherein the conversion device 10 is used to connect an energy storage device A1 and a photovoltaic cell assembly PD. The conversion device 10 can be used to convert the supply voltage Ve output by the energy storage power supply device A1 according to a first control signal and then output it to the photovoltaic cell assembly PD to power the photovoltaic cell assembly PD, so that the photovoltaic cell assembly PD emits light and then performs fault detection. The photovoltaic cell assembly PD can also be called a solar photovoltaic cell assembly, and its function is to convert solar energy into electrical energy, or send it to a battery for storage, or drive a load to work; the photovoltaic cell assembly PD can be composed of a plurality of single photovoltaic cells connected in series and / or in parallel; the energy storage device A1 can be an energy storage device that can provide a certain supply voltage, including but not limited to a battery, an energy storage system, etc.

[0061] The conversion device 10 is further configured to track the maximum output power of the photovoltaic cell assembly PD according to a second control signal and output the electrical energy generated by the photovoltaic cell assembly PD at the maximum output power. The electrical energy output at the maximum output power can be supplied to a power grid or a battery, thereby achieving electrical energy output from the photovoltaic cell assembly PD. The conversion device 10 may include a maximum power point tracking (MPPT) solar control device or other conversion device having both of the aforementioned functions.

[0062] The conversion device designed as above can realize the reverse transmission of the voltage of the external DC power supply to the photovoltaic cell assembly under the first control signal, so that the photovoltaic cell assembly emits light for detection; and can realize the output of the photovoltaic cell assembly power generation voltage at maximum power under the second control signal. Thus, the conversion device can realize the two functions of the traditional MPPT control device and reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter, saving costs while simplifying the circuit structure.

[0063] As a possible implementation, the conversion device is an MPPT control device, which includes a first controllable semiconductor power device 110, a first current acquisition module 120, and a first voltage acquisition module 130. Specifically, as shown in FIG2 , the input end of the first controllable semiconductor power device 110 is electrically connected to the energy storage device A1, the output end of the first controllable semiconductor power device 110 is electrically connected to the first current acquisition module 120, and the first current acquisition module 120 is electrically connected to the first voltage acquisition module 130 after being connected to the photovoltaic cell assembly PD.

[0064] The first controllable semiconductor power device 110 is used to connect the path between the energy storage device A1 and the photovoltaic cell assembly PD in response to the first control signal, so that the output voltage Ve of the energy storage device A1 is converted into the first supply voltage V1 and then transmitted to the photovoltaic cell assembly PD through the first current acquisition module 120 and the first voltage acquisition module 130. In this case, the first current acquisition module is used to perform current detection on the first supply voltage V1 to obtain a first detection current I1, and the first voltage acquisition module is used to perform voltage detection on the first supply voltage V1 to obtain a first detection voltage V11.

[0065] When used to output power from a photovoltaic cell assembly PD, the first current acquisition module 120 and the first voltage acquisition module 130 detect the main circuit DC voltage and output current of the photovoltaic cell assembly PD. The MPPT control device can calculate the output power of the photovoltaic cell assembly PD based on the main circuit DC voltage and output current. When the output voltage is substantially stable, the duty cycle of the first controllable semiconductor power device 110 is altered via a second control signal, thereby generating a current perturbation. Simultaneously, the output current and voltage of the photovoltaic cell assembly PD also change accordingly. The first voltage acquisition module 130 and the first current acquisition module 120 measure the changes in the photovoltaic cell output power and voltage before and after the perturbation to determine the perturbation direction for the next cycle. If the perturbation direction is correct, the solar panel output power increases, and the perturbation continues in the same direction in the next cycle. Otherwise, the perturbation is reversed. This perturbation and observation cycle is repeated until the solar panel output reaches its maximum power point. Similarly, the control process for outputting power from the photovoltaic cell assembly PD at maximum output power is consistent with that of a conventional MPPT control device and will not be further described here.

[0066] As a possible embodiment, the structure of the conversion device 10 may be specifically shown in FIG3 . The first controllable semiconductor power device 110 may specifically include four controllable semiconductor power devices, namely, a controllable semiconductor power device Q1, a controllable semiconductor power device Q2, a controllable semiconductor power device Q3, and a controllable semiconductor power device Q4. The emitter of the controllable semiconductor power device Q1 is connected to the bus N1, the collector of the controllable semiconductor power device Q1 is connected to the emitter of the controllable semiconductor power device Q2, the collector of the controllable semiconductor power device Q2 is connected to the emitter of the controllable semiconductor power device Q3, and the collector of the controllable semiconductor power device Q2 is electrically connected to the first voltage acquisition module 130 via the first current acquisition module 120. The emitter of the controllable semiconductor power device Q4 is connected to the collector of the controllable semiconductor power device Q3, and the collector of the controllable semiconductor power device Q4 is connected to the bus N2. Each controllable semiconductor power device may be an insulated gate bipolar transistor (IGBT) or other controllable switch such as a thyristor.

[0067] As a possible implementation, the MPPT control device can also determine whether the photovoltaic cell assembly PD is faulty based on the first detection voltage collected by the first voltage acquisition module 139 and / or the first detection current collected by the first current acquisition module 120. Specifically, the first detection voltage can be compared with a preset voltage interval and / or the first detection current can be compared with a preset current interval to determine whether the photovoltaic cell assembly PD is faulty.

[0068] The present application provides a photovoltaic system, as shown in FIG4 , which includes a conversion device 10 , a photovoltaic cell assembly PD, and an energy storage device A1 as described in any of the aforementioned embodiments, wherein the photovoltaic cell assembly PD is electrically connected to the energy storage device A1 through the conversion device 10 .

[0069] In the photovoltaic system designed as described above, the conversion device 10 can realize the reverse transmission of the voltage of the external DC power supply to the photovoltaic cell assembly PD under the first control signal, so that the photovoltaic cell assembly PD emits light for detection; and can realize the output of the generated voltage of the photovoltaic cell assembly PD at maximum power under the second control signal, thereby omitting the inverter of the traditional detection circuit and saving the cost of the photovoltaic circuit.

[0070] In an optional implementation of this embodiment, as shown in FIG5 , the photovoltaic system further includes a controller 20 , which is electrically connected to the conversion device 10 , and is configured to send a first control signal or a second control signal to the conversion device 10 .

[0071] Specifically, the controller 20 can be connected to the control terminal of each controllable semiconductor power device of the first controllable semiconductor power device 110 in the conversion device 10. For example, the controller 20 can be connected to the gates of the controllable semiconductor power devices Q1 to Q4, and send a first control signal or a second control signal to control the duty cycle of the controllable semiconductor power devices Q1 to Q4. In addition, the controller 20 can also be electrically connected to the first current acquisition module 120 and the first voltage acquisition module 130 in the conversion device 10. After sending the first control signal, the controller 20 can obtain the first detection current I1 collected by the first current acquisition module 120 and the first detection voltage V11 collected by the first voltage acquisition module 130, and determine whether the photovoltaic cell assembly PD is faulty based on the first detection voltage V11 and / or the first detection current I1.

[0072] In an optional implementation of this embodiment, as shown in Figure 6, the energy storage device A1 includes an energy storage battery A10 and a DC voltage converter A11; the energy storage battery A10 is electrically connected to the conversion device 10 through the DC voltage converter A11; the controller 20 is electrically connected to the DC voltage converter A11; the controller 20 is further used to send a third control signal to the DC voltage converter A11; the DC voltage converter A11 operates in a boost mode according to the third control signal, thereby boosting the output voltage Va of the energy storage battery to a second supply voltage V2 to obtain the supply voltage Ve of the energy storage power supply device A1, that is, V2=Ve; the conversion device 10 is specifically used to operate in a buck mode according to the first control signal, and step down the supply voltage Ve of the energy storage power supply device A1 to the first supply voltage V1.

[0073] Based on the above, the DC voltage converter A11 may include a second controllable semiconductor power device A110, a second current acquisition module A111 and a second voltage acquisition module A112; the energy storage battery A10 is electrically connected to the second current acquisition module A111 through the second voltage acquisition module A112, and the second current acquisition module A111 is electrically connected to the conversion device 10 through the second controllable semiconductor power device A110; the second voltage acquisition module A112 is used to acquire the output voltage of the energy storage battery A1; the second current acquisition module A111 is used to acquire the output current corresponding to the output voltage of the energy storage battery A1; the second controllable semiconductor power device A110 is used to boost the output voltage Va of the energy storage battery A10 to a second supply voltage V2 according to a third control signal.

[0074] Specifically, as shown in FIG7 , the second controllable semiconductor power device A110 may also include four controllable semiconductor power devices, namely controllable semiconductor power devices Q5 to Q8, similar to the first controllable semiconductor power device 110. The emitter of controllable semiconductor power device Q5 and the emitter of controllable semiconductor power device Q1 are both electrically connected to bus N1, and the collector of controllable semiconductor power device Q8 and the collector of controllable semiconductor power device Q4 are both electrically connected to bus N2. In this topology, based on the duty cycle of the first control signal, controllable semiconductor power devices Q1 and Q3 are first controlled to be closed, and then controllable semiconductor power devices Q2 and Q4 are controlled to be closed, thereby reducing the supply voltage Ve of the energy storage device A1 to the first supply voltage V1. Based on the duty cycle of the third control signal, controllable semiconductor power devices Q5 and Q7 are first controlled to be closed, and then controllable semiconductor power devices Q6 and Q8 are controlled to be closed, thereby increasing the output voltage Va of the energy storage battery to the second supply voltage V2.

[0075] In an optional implementation of this embodiment, as shown in FIG8 , the photovoltaic system further includes an AC voltage conversion device 30. The photovoltaic cell assembly PD is electrically connected to the AC voltage conversion device 30 via the conversion device 10. The AC voltage conversion device 30 is configured to be electrically connected to the power grid B1. The AC voltage conversion device 30 is configured to convert the voltage corresponding to the maximum output power of the photovoltaic cell assembly PD received into a corresponding AC output voltage, and transmit the AC output voltage to the power grid B1. Specifically, the AC voltage conversion device 30 may be a DC-AC converter or other currently available DC-to-AC conversion device.

[0076] In an optional implementation of this embodiment, the photovoltaic system may further include a fault detection device (not shown); the fault detection device is configured to capture an image of the photovoltaic cell assembly PD after the conversion device 10 converts the supply voltage output by the energy storage power supply device A1 according to the first control signal and supplies power to the photovoltaic cell assembly PD, and detect whether the photovoltaic cell assembly PD is faulty based on the captured image. The method for detecting whether the photovoltaic cell assembly PD is faulty based on the captured image is consistent with conventional detection methods and will not be further described here.

[0077] The present application provides a control method, which can be applied to the aforementioned controller 20, and can also be used in controllers known in the art that can perform similar functions. As shown in FIG9 , the control method may include the following steps:

[0078] Step S900: sending a first control signal to the conversion device, so that the conversion device converts the supply voltage output by the energy storage power supply device in response to the first control signal and then supplies power to the photovoltaic cell assembly.

[0079] Step S910: Sending a second control signal to the conversion device so that the conversion device tracks the maximum output power of the photovoltaic cell assembly in response to the second control signal and transmits the electric energy generated by the photovoltaic cell assembly to the grid at a voltage corresponding to the maximum output power.

[0080] In the control method designed above, the controller of this solution can transmit different control signals to the conversion device in different scenarios, so that the conversion device converts the supply voltage output by the energy storage power supply device into voltage and then supplies power to the photovoltaic cell assembly when receiving the first control signal, and outputs the electric energy generated by the photovoltaic cell assembly at the maximum output power when receiving the second control signal. In this way, the conversion device can realize the two functions of the traditional MPPT control device and reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving costs.

[0081] In an optional implementation of this embodiment, before sending the first control signal, the controller may also receive the self-test results of the energy storage device. Only after the self-test results indicate a fault-free state will the controller execute the step of sending the first control signal to the conversion device, thereby avoiding circuit failures caused by a fault in the energy storage device. Furthermore, it should be noted that in addition to receiving the self-test results of the energy storage device, this solution may also receive the self-test results of the conversion device. Only after the self-test results indicate a fault-free state will the controller execute the step of sending the first control signal to the conversion device. The aforementioned energy storage device is energy storage device A1 described above and will not be described in detail here.

[0082] In an optional implementation of this embodiment, when a photovoltaic cell assembly fails, the current transmitted by the conversion device to the photovoltaic cell assembly will change. Therefore, based on the aforementioned conversion device including the first current acquisition module, as shown in FIG10 , the control method may further include the following steps:

[0083] Step S1000: obtaining a first detection current, and determining whether the photovoltaic cell assembly is faulty based on the first detection current.

[0084] Specifically, the controller can determine whether the first deviation value between the first detection current and the target current value is greater than the first preset threshold value. If the first deviation value between the first detection current and the target current value is greater than the first preset threshold value, it means that the first detection current undergoes a large change after passing through the photovoltaic component. Therefore, it is determined that the photovoltaic cell component has a fault.

[0085] In an optional implementation of this embodiment, when a photovoltaic cell assembly fails, the voltage transmitted by the conversion device to the photovoltaic cell assembly will also change. Therefore, based on the aforementioned conversion device including the first voltage acquisition module, as shown in FIG11 , the control method may further include the following steps:

[0086] Step S1100: obtaining a first detection voltage, and determining whether the photovoltaic cell assembly is faulty based on the first detection voltage.

[0087] Specifically, the controller can determine whether the first deviation value between the first detection voltage and the target voltage value is greater than the second preset threshold value. If the first deviation value between the first detection voltage and the target current value is greater than the second preset threshold value, it means that the first detection voltage undergoes a large change after passing through the photovoltaic component. Therefore, it is determined that the photovoltaic cell component has a fault.

[0088] It should be noted that this solution can use current alone to determine if a photovoltaic cell assembly is faulty, voltage alone, or both current and voltage simultaneously. Furthermore, in addition to detecting the first detection current and / or the first detection voltage after sending a first control signal to determine if a photovoltaic cell assembly is faulty, this solution can also detect data collected by the first current acquisition module and the first voltage acquisition module, respectively, after sending a second control signal, to determine if a photovoltaic cell assembly is faulty.

[0089] FIG12 shows a schematic block diagram of a control device provided by the present application. It should be understood that the device corresponds to the method embodiment executed by the controller in FIG9 and FIG11 and is capable of executing the steps involved in the aforementioned method. The specific functions of the device can be found in the description above. To avoid repetition, a detailed description is omitted here. The device includes at least one software function module that can be stored in a memory in the form of software or firmware or embedded in the operating system (OS) of the device. Specifically, the device includes: a sending module 1200 that sends a first control signal to a conversion device so that the conversion device converts the supply voltage output by the energy storage power supply device in response to the first control signal and then supplies power to the photovoltaic cell assembly; and sends a second control signal to the conversion device so that the conversion device tracks the maximum output power of the photovoltaic cell assembly in response to the second control signal and transmits the electrical energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0090] In the technical solution of the embodiment of the present application, this solution can transmit different control signals to the conversion device in different scenarios, so that the conversion device converts the supply voltage output by the energy storage power supply device under the first control signal and then supplies power to the photovoltaic cell assembly, and outputs the electric energy generated by the photovoltaic cell assembly at the maximum output power under the second control signal. In this way, the conversion device can realize the two functions of the traditional MPPT control device and reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving costs.

[0091] According to some embodiments of the present application, the device also includes an acquisition module 1210 for acquiring a first detection current, wherein the first detection current is obtained by collecting the current corresponding to the first supply voltage by the first current acquisition module, and the first supply voltage is generated by reducing the supply voltage of the energy storage power supply device by the first controllable semiconductor power device; a determination module 1220 is used to determine whether the photovoltaic cell assembly is faulty based on the first detection current.

[0092] According to some embodiments of the present application, the determination module 1220 is specifically used to determine whether the first deviation value between the first detection current and the target current value is greater than the first preset threshold value; if the first deviation value between the first detection current and the target current value is greater than the first preset threshold value, it is determined that the photovoltaic cell assembly has a fault.

[0093] According to some embodiments of the present application, the acquisition module 1210 is also used to obtain a first detection voltage, wherein the first detection voltage is obtained by acquiring a voltage corresponding to a first supply voltage by a first voltage acquisition module, and the first supply voltage is generated by stepping down the supply voltage of the energy storage power supply device by a first controllable semiconductor power device; the determination module 1220 is used to determine whether the photovoltaic cell assembly is faulty based on the first detection voltage.

[0094] According to some embodiments of the present application, the determination module 1220 is also specifically used to determine whether the second deviation value between the first detection voltage and the target voltage value is greater than the second preset threshold value; if the second deviation value between the first detection voltage and the target voltage value is greater than the second preset threshold value, it is determined that the photovoltaic cell assembly has a fault.

[0095] According to some embodiments of the present application, as shown in Figure 13, the present application provides an electronic device 13, including: a processor 1301 and a memory 1302, the processor 1301 and the memory 1302 are interconnected and communicate with each other through a communication bus 1303 and / or other forms of connection mechanisms (not marked), and the memory 1302 stores a computer program executable by the processor 1301. When the computing device is running, the processor 1301 executes the computer program to execute the method executed by the external terminal in any optional implementation method, such as steps S900 to S910: sending a first control signal to the conversion device, so that the conversion device converts the supply voltage output by the energy storage power supply device in response to the first control signal and then supplies power to the photovoltaic cell assembly; sending a second modulation signal to the conversion device, so that the conversion device tracks the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmits the electric energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0096] The present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method in any of the aforementioned optional implementations is executed.

[0097] Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0098] The present application provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the method in any optional implementation manner.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above. For the sake of simplicity, they are not provided in detail. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A conversion device, characterized in that: The conversion device is used to connect the energy storage device and the photovoltaic cell assembly; The conversion device is used to convert the power supply voltage output by the energy storage device in response to the first control signal and then supply power to the photovoltaic cell assembly; And in response to a second control signal, the maximum output power of the photovoltaic cell assembly is tracked, and the electric energy generated by the photovoltaic cell assembly is output at the maximum output power.

2. The conversion device according to claim 1, characterized in that The conversion device is an MPPT control device, and the MPPT control device includes a first controllable semiconductor power device; The first controllable semiconductor power device is used to open the path between the energy storage device and the photovoltaic cell assembly in response to the first control signal, so that the supply voltage of the energy storage device is converted into a first supply voltage and then transmitted to the photovoltaic cell assembly.

3. The conversion device according to claim 2, characterized in that The MPPT control device further includes a first current acquisition module, which is connected to the path; and / or, The MPPT control device further includes a first voltage acquisition module connected to the passage.

4. The conversion device according to claim 3, characterized in that The MPPT control device includes a first current acquisition module, which is used to perform current detection on the first supply voltage to obtain a first detection current; The MPPT control device is further configured to determine whether the photovoltaic cell assembly is faulty based on the first detection current.

5. The conversion device according to claim 3, characterized in that: The MPPT control device includes the first voltage acquisition module, which is used to perform voltage detection on the first supply voltage to obtain a first detection voltage; The MPPT control device is further configured to determine whether the photovoltaic cell assembly is faulty based on the first detection voltage.

6. A photovoltaic system, characterized in that: The photovoltaic system comprises the conversion device according to any one of claims 1 to 3, the photovoltaic cell assembly, and the energy storage device, wherein the photovoltaic cell assembly is electrically connected to the energy storage device via the conversion device.

7. The photovoltaic system according to claim 6, characterized in that: The photovoltaic system further includes a controller; The controller is electrically connected to the conversion device; The controller is configured to send the first modulation signal to the conversion device.

8. The photovoltaic system according to claim 6, characterized in that: in, The energy storage device includes an energy storage battery and a DC voltage converter; The energy storage battery is electrically connected to the conversion device through the DC voltage converter; the controller is electrically connected to the DC voltage converter; The controller is further configured to send a third control signal to the DC voltage converter; The DC voltage converter is used to boost the output voltage of the energy storage battery to a second supply voltage in response to the third control signal to obtain the supply voltage of the energy storage device; The conversion device is specifically used to step down the supply voltage of the energy storage device to the first supply voltage.

9. The photovoltaic system according to claim 8, characterized in that: The DC voltage converter includes a second controllable semiconductor power device, a second current acquisition module and a second voltage acquisition module; The energy storage battery is electrically connected to the second current acquisition module via the second voltage acquisition module, and the second current acquisition module is electrically connected to the conversion device via the second controllable semiconductor power device; The second voltage acquisition module is used to acquire the output voltage of the energy storage battery; The second current acquisition module is used to acquire the output current corresponding to the output voltage of the energy storage battery; The second controllable semiconductor power device is configured to boost the output voltage of the energy storage battery to the second supply voltage in response to the third control signal.

10. The photovoltaic system according to claim 7, characterized in that: The controller is further configured to collect the first detection voltage and / or the first detection current after sending the first modulation signal, and determine whether the photovoltaic cell assembly is faulty based on the first detection voltage and / or the first detection current.

11. The photovoltaic system according to claim 6, characterized in that: The photovoltaic system further includes an AC voltage conversion device; the photovoltaic cell assembly is electrically connected to the AC voltage conversion device via the conversion device, and the AC voltage conversion device is used to be electrically connected to the power grid; The AC voltage conversion device is used to convert the voltage corresponding to the maximum output power of the received photovoltaic cell assembly into a corresponding AC output voltage, and transmit the AC output voltage to the power grid.

12. The photovoltaic system according to claim 6, characterized in that: The photovoltaic system also includes a fault detection device, which is used to collect an image of the photovoltaic cell assembly after the conversion device converts the supply voltage output by the energy storage power supply device according to the first control signal to power the photovoltaic cell assembly, and detect whether the photovoltaic cell assembly is faulty based on the collected image.

13. A control method, characterized in that: The control method is used to control a conversion device, which is used to connect an energy storage power supply device and a photovoltaic cell assembly; the method includes: Sending a first control signal to the conversion device, so that the conversion device performs voltage conversion on the supply voltage output by the energy storage and power supply device in response to the first control signal and then supplies power to the photovoltaic cell assembly; And sending a second control signal to the conversion device so that the conversion device tracks the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmits the electric energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

14. The method according to claim 13, characterized in that Before sending the first control signal to the conversion device, the method further includes: A self-test result of the energy storage device is received, and after the self-test result is no fault, a step of sending a first control signal to the conversion device is performed.

15. The method according to claim 13, characterized in that The conversion device includes a first controllable semiconductor power device and a first current acquisition module. After sending a first control signal to the conversion device, the method further includes: Obtaining the first detection current; wherein the first detection current is obtained by the first current acquisition module acquiring a current corresponding to a first supply voltage, and the first supply voltage is generated by stepping down the supply voltage of the energy storage device by the first controllable semiconductor power device; Determine whether the photovoltaic cell assembly is faulty based on the first detection current.

16. The method according to claim 15, characterized in that The determining whether the photovoltaic cell assembly is faulty according to the first detection current includes: Determining whether a first deviation between the first detection current and the target current value is greater than a first preset threshold; If a first deviation between the first detection current and the target current value is greater than a first preset threshold, it is determined that the photovoltaic cell assembly has a fault.

17. The method according to claim 13, characterized in that The conversion device includes a first controllable semiconductor power device and a first voltage acquisition module. After sending a first control signal to the conversion device, the method further includes: Obtaining the first detection voltage; wherein the first detection voltage is obtained by the first voltage acquisition module acquiring a voltage corresponding to a first supply voltage, and the first supply voltage is generated by stepping down the supply voltage of the energy storage device by the first controllable semiconductor power device; Determine whether the photovoltaic cell assembly is faulty based on the first detection voltage.

18. The method according to claim 17, characterized in that The determining whether the photovoltaic cell assembly is faulty according to the first detection voltage includes: Determining whether a second deviation between the first detection voltage and the target voltage is greater than a second preset threshold; If a second deviation between the first detection voltage and the target voltage is greater than a second preset threshold, it is determined that the photovoltaic cell assembly has a fault.

19. The method according to claim 13, wherein The energy storage device includes an energy storage battery and a DC voltage converter, and the conversion device is electrically connected to the energy storage battery via the DC voltage converter; the method further includes: A third control signal is sent to the DC voltage converter, so that the DC voltage converter boosts the output voltage of the energy storage battery to a second supply voltage according to the third control signal, thereby obtaining the supply voltage of the energy storage device.

20. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 13 to 19 is implemented.

21. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 13 to 19 is implemented.

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