Conversion device, photovoltaic system and control method

Abstract

The application discloses a conversion device, a photovoltaic system and a control method. The conversion device provided by the application can realize the function of transmitting the voltage of an external direct-current power supply to a photovoltaic cell assembly reversely under a first control signal, so that the photovoltaic cell assembly emits light to perform detection; and the conversion device can realize the function of outputting the power generation voltage of the photovoltaic cell assembly with maximum power under a second control signal, so that the inverter of a traditional detection circuit is omitted, and the cost of the photovoltaic circuit is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cells, in particular to a conversion device, a photovoltaic system and a control method. BACKGROUND

[0002] At present, new energy power generation methods such as photovoltaic power generation and wind power generation are rising, and photovoltaic cell components play a crucial role in photovoltaic power generation. However, photovoltaic cell components are prone to failure, so it is often necessary to detect the failure of photovoltaic cell components.

[0003] For photovoltaic cell component failure inspection, the current conventional technology is to rectify the alternating current of the power grid or the alternating current energy storage device through an inverter to direct current, to power the photovoltaic cell component, to make the photovoltaic cell component emit light, and then to collect images through a mobile image collection device to perform failure detection on an EL (Electroluminescent) detection device.

[0004] However, the above method requires the photovoltaic cell component to be powered after rectification by an inverter, which requires the cost of the inverter, resulting in high cost; and the photovoltaic cell component cannot be detected without an inverter. SUMMARY

[0005] In view of the above problems, the present application provides a conversion device, a photovoltaic system and a control method, which can solve the problems of high inverter cost and environmental restrictions of using only inverters caused by the need to use an inverter to rectify alternating current to direct current to power the photovoltaic cell component for failure detection of the photovoltaic cell.

[0006] In a first aspect, the present application provides a conversion device for connecting an energy storage device and a photovoltaic cell component; the conversion device is used to power the photovoltaic cell component with the voltage converted by the energy storage power supply device in response to a first control signal; and to track the maximum output power of the photovoltaic cell component in response to a second control signal, and to output the power generated by the photovoltaic cell component at the maximum output power.

[0007] The conversion device designed above can realize the function of transmitting the voltage of an external direct current power supply to the photovoltaic cell component in reverse under the first control signal, so that the photovoltaic cell component emits light for detection; and can realize the function of outputting the photovoltaic cell component power at the maximum power under the second control signal, so that the conversion device can realize the functions of traditional MPPT and reverse power supply to the photovoltaic cell component, thereby omitting the traditional detection circuit inverter and saving costs.

[0008] In an optional implementation of the first aspect, the conversion device is an MPPT control device, the MPPT control device comprising a first controllable semiconductor power device; the first controllable semiconductor power device is configured to turn on a path between the energy storage device and the photovoltaic cell assembly in response to a first control signal, so that the power supply voltage of the energy storage device is transmitted to the photovoltaic cell assembly after being converted into a first power supply voltage. This implementation improves the traditional MPPT control device, so that the traditional MPPT control device has the functions of maximum power tracking and reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving costs.

[0009] In an optional implementation of the first aspect, the MPPT control device further comprises a first current acquisition module connected to the path; and / or, the MPPT control device further comprises a first voltage acquisition module connected to the path.

[0010] In an optional implementation of the first aspect, the MPPT control device comprises a first current acquisition module configured to detect the current of the first power supply voltage to obtain a first detection current; and the MPPT control device is further configured to determine whether the photovoltaic cell assembly is faulty according to the first detection current.

[0011] In an optional implementation of the first aspect, the MPPT control device comprises a first voltage acquisition module configured to detect the voltage of the first power supply voltage to obtain a first detection voltage; and the MPPT control device is further configured to determine whether the photovoltaic cell assembly is faulty according to the first detection voltage. This implementation designs an MPPT control device that can determine whether the photovoltaic cell assembly is faulty according to the first detection voltage detected by the first voltage acquisition module, thereby increasing the determination mode of the photovoltaic cell assembly fault and improving the reliability of the photovoltaic cell assembly.

[0012] In a second aspect, the application provides a photovoltaic system, characterized in that the photovoltaic circuit comprises the conversion device of any of the optional implementations of the first aspect, the photovoltaic cell assembly, and the energy storage power supply device, and the photovoltaic cell assembly is electrically connected to the energy storage power supply device through the conversion device.

[0013] In the technical solution of the embodiments of the application, the conversion device can realize the functions of 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 the function of maximum power output of the photovoltaic cell assembly under the second control signal, thereby omitting the inverter of the traditional detection circuit and saving the cost of the photovoltaic system.

[0014] In an optional implementation of the second aspect, the photovoltaic circuit further comprises a controller; the controller is electrically connected to the conversion device respectively; and the controller is configured to send a first control signal to the conversion device. In this implementation, the controller sends the first control signal, so that the sending time of the first control signal is controllable, and thus the fault detection of the photovoltaic system is controllable.

[0015] In an optional implementation of the second aspect, the energy storage device comprises 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 configured to boost the output voltage of the energy storage battery to a second power supply voltage in response to the third control signal, so as to obtain the power supply voltage of the energy storage device; and the conversion device is configured to step down the power supply voltage of the energy storage device to the first power supply voltage. In this implementation, the energy storage battery supplies DC power, and then the DC voltage converter and the conversion device convert the voltage, so that the first power supply voltage output to the photovoltaic cell assembly meets the voltage requirement of the photovoltaic cell assembly.

[0016] In an optional implementation of the second aspect, the DC voltage converter comprises 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 through the second voltage acquisition module, and the second current acquisition module is electrically connected to the conversion device through the second controllable semiconductor power device; the second voltage acquisition module is configured to acquire the output voltage of the energy storage battery; the second current acquisition module is configured to acquire the output current corresponding to the output voltage of the energy storage battery; and the second controllable semiconductor power device is configured to boost the output voltage of the energy storage battery to the second power supply voltage in response to the third control signal.

[0017] In an optional implementation of the second aspect, the controller is further configured to, after sending the first control signal, acquire the first detection voltage and / or the 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 this implementation, in addition to the conventional image acquisition method for photovoltaic cell assembly fault detection, the controller is used to detect whether the current and voltage of the photovoltaic cell assembly during the reverse power supply process are as expected based on the first detection voltage and / or the first detection current, so as to determine whether the photovoltaic cell assembly is faulty, and thus the reliability of the photovoltaic cell assembly fault detection is ensured through multiple methods.

[0018] In an optional implementation of the second aspect, the photovoltaic system further comprises an alternating voltage conversion device; the photovoltaic cell assembly is electrically connected to the alternating voltage conversion device through the conversion device, and the alternating voltage conversion device is configured to be electrically connected to the power grid; the alternating voltage conversion device is configured to convert the voltage corresponding to the maximum output power of the photovoltaic cell assembly received into a corresponding alternating output voltage, and transmit the alternating output voltage to the power grid. The conversion device of the embodiment can also transmit the voltage generated by the photovoltaic cell assembly to the alternating voltage conversion device, and then output the electrical energy generated by the photovoltaic cell assembly to the power grid.

[0019] In an optional implementation of the second aspect, the photovoltaic system further comprises a fault detection device; the fault detection device is configured to collect images of the photovoltaic cell assembly after the conversion device supplies power to the photovoltaic cell assembly after voltage conversion of the power supply voltage output by the energy storage device according to the first control signal, and detect whether the photovoltaic cell assembly is faulty according to the collected images.

[0020] In a third aspect, the application provides a control method for controlling a conversion device, the conversion device being configured to connect an energy storage device and a photovoltaic cell assembly; the method comprises: sending a first control signal to the conversion device to make the conversion device supply power to the photovoltaic cell assembly after voltage conversion of the power supply voltage output by the energy storage device in response to the first control signal; and sending a second control signal to the conversion device to make the conversion device track the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmit the electrical energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0021] In the technical solution of the embodiments of the application, different control signals can be transmitted to the conversion device in different scenarios, so that the conversion device supplies power to the photovoltaic cell assembly after voltage conversion of the power supply voltage output by the energy storage device in response to the first control signal, and outputs the electrical energy generated by the photovoltaic cell assembly at the maximum output power in response to the second control signal, so that 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.

[0022] In an optional embodiment of the third aspect, before sending the first control signal to the conversion device, the method further comprises: receiving a self-check result of the energy storage device, and performing the step of sending the first control signal to the conversion device after the self-check result is fault-free. In this implementation, the step of sending the first control signal to the conversion device is performed only after the self-check result is fault-free, thereby avoiding the circuit failure problem caused by the fault of the energy storage device.

[0023] In an optional embodiment of the third aspect, the conversion device comprises a first controllable semiconductor power device and a first current acquisition module, and after the first control signal is sent to the conversion device, the method further comprises: acquiring a first detection current; wherein the first detection current is obtained by the first current acquisition module from a current corresponding to the first supply voltage, and the first supply voltage is generated by the first controllable semiconductor power device by stepping down the supply voltage of the energy storage device; and determining whether the photovoltaic cell module is faulty according to the first detection current.

[0024] In an optional embodiment of the third aspect, determining whether the photovoltaic cell module is faulty according to the first detection current comprises: determining whether a first deviation value of the first detection current from a target current value is greater than a first preset threshold value; and if the first deviation value of the first detection current from the target current value is greater than the first preset threshold value, determining that the photovoltaic cell module is faulty.

[0025] In an optional embodiment of the third aspect, the conversion device comprises a first controllable semiconductor power device and a first voltage acquisition module, and after the first control signal is sent to the conversion device, the method further comprises: acquiring a first detection voltage; wherein the first detection voltage is obtained by the first voltage acquisition module from a voltage corresponding to the first supply voltage, and the first supply voltage is generated by the first controllable semiconductor power device by stepping down the supply voltage of the energy storage device; and determining whether the photovoltaic cell module is faulty according to the first detection voltage.

[0026] In an optional embodiment of the third aspect, determining whether the photovoltaic cell module is faulty according to the first detection voltage comprises: determining whether a second deviation value of the first detection voltage from a target voltage value is greater than a second preset threshold value; and if the second deviation value of the first detection voltage from the target voltage value is greater than the second preset threshold value, determining that the photovoltaic cell module is faulty. The above embodiment determines whether the current and voltage of the photovoltaic cell module during the reverse power supply process are as expected based on the first detection voltage and / or the first detection current, to determine whether the photovoltaic cell module is faulty, and further ensures the reliability of the fault detection of the photovoltaic cell module through various ways.

[0027] In an optional embodiment of the third aspect, the energy storage device comprises an energy storage battery and a direct current voltage converter, and the conversion device is electrically connected to the energy storage battery through the direct current voltage converter; and the method further comprises: sending a third control signal to the direct current voltage converter, so that the direct current voltage converter steps up 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.

[0028] In a fourth aspect, the present application provides a control device for controlling a conversion device, the conversion device being used to connect an energy storage power supply device and a photovoltaic cell assembly; the device comprises: a sending module, which sends a first control signal to the conversion device, so that the conversion device converts the power supply voltage output by the energy storage device and 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 electrical energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0029] The control device designed as 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 and supplies power to the photovoltaic cell assembly when receiving the first control signal, and outputs the electrical energy generated by the photovoltaic cell assembly at the maximum output power when receiving the second control signal, so that 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.

[0030] 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 the processor executes the computer program to execute the method in the third aspect or any optional implementation manner of the third aspect.

[0031] In a sixth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to execute the method in the third aspect or any optional implementation manner of the third aspect.

[0032] In a seventh aspect, the present application provides a computer program product, which, when running on a computer, causes the computer to execute the method in the third aspect or any optional implementation manner of the third aspect.

[0033] The above description is only a summary of the technical solutions of the present application, in order to enable the technical solutions of the present application to be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Moreover, the same reference numerals in all the drawings represent the same or similar elements. In the drawings:

[0035] Figure 1 A first structural schematic view of a conversion device provided for the embodiment;

[0036] Figure 2 A second structural schematic view of a conversion device provided for the embodiment;

[0037] Figure 3 A third structural schematic view of a conversion device provided for the embodiment;

[0038] Figure 4 A first structural schematic view of a photovoltaic circuit provided for the embodiment;

[0039] Figure 5 A second structural schematic view of a photovoltaic circuit provided for the embodiment;

[0040] Figure 6 A third structural schematic view of a photovoltaic circuit provided for the embodiment;

[0041] Figure 7 A fourth structural schematic view of a photovoltaic circuit provided for the embodiment;

[0042] Figure 8 A fifth structural schematic view of a photovoltaic circuit provided for the embodiment;

[0043] Figure 9 A first flowchart of a control method provided for the embodiment;

[0044] Figure 10 A second flowchart of a control method provided for the embodiment;

[0045] Figure 11 A third flowchart of a control method provided for the embodiment;

[0046] Figure 12 A structural schematic view of a control device provided for the embodiment;

[0047] Figure 13 A structural schematic view of an electronic device provided for the embodiment.

[0048] The reference signs in the detailed description are as follows:

[0049] 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 device; 20 - controller; 30 - AC voltage conversion device; 1200 - sending module; 1210 - obtaining module; 1220 - determining module; 13 - electronic device; 1301 - processor; 1302 - memory; 1303 - communication bus. DETAILED DESCRIPTION

[0050] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill 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 the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0053] In this paper, "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0055] At present, new energy power generation methods such as photovoltaic power generation and wind power generation are rising, and photovoltaic cell components play a crucial role in photovoltaic power generation. However, photovoltaic cell components are prone to failure, so photovoltaic cell components often need to be detected for failure. For photovoltaic cell component failure inspection methods, the current conventional technology is to convert the alternating current of the power grid or the alternating current energy storage device into direct current through an inverter to power the photovoltaic cell component, so that the photovoltaic cell component emits light, and then the image acquisition device is moved to collect images for the EL detection device to detect failures.

[0056] The inventor has noticed that this way of detecting light by converting alternating current to direct current to power the photovoltaic cell component to make it emit light requires an inverter for power conversion, resulting in the cost of the inverter, leading to high costs. Without an inverter, photovoltaic cell components cannot be detected.

[0057] The Maximum Power Point Tracking (MPPT) control device is commonly used to detect the power generation voltage of the photovoltaic cell component in real time and track the highest voltage and current value (VI) to make the system output maximum power to charge the battery or the power grid. Therefore, MPPT is commonly configured with photovoltaic cell components, that is, photovoltaic cell components are commonly used with MPPT.

[0058] To solve the above problems, the inventor has designed a conversion device, a photovoltaic system and a control method, so that the designed conversion device can realize the reverse transmission of the voltage of the external direct current power supply to the photovoltaic cell component under the first control signal, so that the photovoltaic cell component emits light for detection. And under the second control signal, the photovoltaic cell component generates voltage with maximum power output, so that one device design includes two functions, thereby omitting the traditional detection circuit inverter and saving costs.

[0059] Specifically, the present application provides a conversion device, as shown in Figure 1 The conversion device 10 is used to connect the energy storage device A1 and the photovoltaic cell component PD. The conversion device 10 can be used to output the power supply voltage Ve output by the energy storage power supply device A1 to the photovoltaic cell component PD after voltage conversion according to the first control signal, to power the photovoltaic cell component PD, so that the photovoltaic cell component PD emits light and further detects failures. The photovoltaic cell component PD can also be called a solar photovoltaic cell component, which converts solar energy into electrical energy, or stores it in a battery, or drives the load to work. The photovoltaic cell component PD can be composed of a plurality of single photovoltaic cells in series and / or parallel combination. The energy storage device A1 can be an energy storage device that can provide a certain power supply voltage, including but not limited to a battery, an energy storage system, etc.

[0060] The conversion device 10 is also used for tracking the maximum output power of the photovoltaic cell assembly PD according to the second control signal, and outputting the electric energy generated by the photovoltaic cell assembly PD at the maximum output power, and the electric energy output at the maximum output power can be output to the power grid or the storage battery, so as to realize the electric energy output of the photovoltaic cell assembly PD. Wherein, the conversion device 10 can include a maximum power point tracking (MPPT) control device or other conversion device with the above two functions.

[0061] The conversion device designed above can realize the function of transmitting the voltage of the external DC power supply to the photovoltaic cell assembly in reverse under the first control signal, so that the photovoltaic cell assembly emits light for detection; and realize the function of outputting the photovoltaic cell assembly power generation voltage at the maximum power under the second control signal, so that the conversion device can realize the two functions of the traditional MPPT control device and the reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter, saving costs and simplifying the structure of the circuit.

[0062] 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 the figure, the input end of the first controllable semiconductor power device 110 is used for electrical connection with the energy storage device A1, the output end of the first controllable semiconductor power device 110 is electrically connected with the first current acquisition module 120, and the first current acquisition module 120 is connected with the first voltage acquisition module 130 and used for electrical connection with the photovoltaic cell assembly PD. Figure 2

[0063] The first controllable semiconductor power device 110 is used for turning on 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 power 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 for current detection of the first power supply voltage V1 to obtain the first detection current I1, and the first voltage acquisition module is used for voltage detection of the first power supply voltage V1 to obtain the first detection voltage V11.

[0064] ​When used to output the electric energy of the photovoltaic cell assembly PD, the first current acquisition module 120 and the first voltage acquisition module 130 detect the main loop direct current voltage and the output current of the photovoltaic cell assembly PD, and the MPPT control device can calculate the output power of the photovoltaic cell assembly PD according to the main loop direct current voltage and the output current. In the case that the output voltage is basically stable, the duty cycle of the first controllable semiconductor power device 110 is changed through the second control signal, so as to generate current perturbation. At the same time, the output current voltage of the photovoltaic cell assembly PD will also change. The changes of the output power and voltage of the photovoltaic cell before and after the perturbation are measured through the first voltage acquisition module 130 and the first current acquisition module 120, so as to determine the perturbation direction of the next period. When the perturbation direction is correct, the output power of the solar panel increases, and the next period continues to perturb in the same direction. Otherwise, perturb in the opposite direction. In this way, the perturbation and observation are repeatedly performed to make the output of the solar panel reach the maximum power point. Similarly, the control process of outputting the electric energy of the photovoltaic cell assembly PD with the maximum output power is consistent with the control process of the conventional MPPT control device, which will not be described here.

[0065] As a possible implementation, the structure of the conversion device 10 can be specifically as shown in the figure Figure 3 The first controllable semiconductor power device 110 can specifically include four controllable semiconductor power devices, namely controllable semiconductor power device Q1, controllable semiconductor power device Q2, controllable semiconductor power device Q3 and controllable semiconductor power device Q4. The emitter of the controllable semiconductor power device Q1 is connected with the bus N1. The collector of the controllable semiconductor power device Q1 is connected with the emitter of the controllable semiconductor power device Q2. The collector of the controllable semiconductor power device Q2 is connected with the emitter of the controllable semiconductor power device Q3, and the collector of the controllable semiconductor power device Q2 is electrically connected with the first current acquisition module 120 and the first voltage acquisition module 130. The emitter of the controllable semiconductor power device Q4 is connected with the collector of the controllable semiconductor power device Q3. The collector of the controllable semiconductor power device Q4 is connected with the bus N2. The emitter of the controllable semiconductor power device Q2 is connected with the positive electrode of the capacitor C1. The collector of the controllable semiconductor power device Q3 is connected with the negative electrode of the capacitor C1. The cathode of the diode D1 is connected with the positive electrode of the capacitor C1. The anode of the diode D1 is connected with the cathode of the diode D2. The anode of the diode D2 is connected with the negative electrode of the capacitor C1. The positive electrode of the capacitor C2 is connected with the bus N1. The negative electrode of the capacitor C2 is connected with the positive electrode of the capacitor C3 and the anode of the diode D1. The negative electrode of the capacitor C3 is connected with the bus N2. Each controllable semiconductor power device can be an insulated gate bipolar transistor IGBT or other controllable form of switch such as thyristor and the like.

[0066] 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 collection module 139 and / or the first detection current collected by the first current collection 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, so as to determine whether the photovoltaic cell assembly PD is faulty.

[0067] The present application provides a photovoltaic system, as shown in the drawings, which comprises the conversion device 10 described in any of the foregoing embodiments, a photovoltaic cell assembly PD, and an energy storage device A1. The photovoltaic cell assembly PD is electrically connected to the energy storage device A1 through the conversion device 10. Figure 4

[0068] The photovoltaic system designed as above, the conversion device 10 can realize the function of transmitting the voltage of the external DC power source to the photovoltaic cell assembly PD reversely under the first control signal, so that the photovoltaic cell assembly PD emits light for detection; and realize the function of outputting the photovoltaic cell assembly PD power voltage with maximum power under the second control signal, thereby omitting the inverter of the traditional detection circuit, and further saving the cost of the photovoltaic circuit.

[0069] In an optional embodiment of the present embodiment, as shown in the drawings, the photovoltaic system further comprises a controller 20 electrically connected to the conversion device 10. The controller 20 is configured to send the first control signal or the second control signal to the conversion device 10. Figure 5

[0070] Specifically, the controller 20 can be connected to the control end of each controllable semiconductor power device in the conversion device 10, for example, the controller 20 is connected to the gate of the controllable semiconductor power devices Q1 to Q4, and sends the first control signal or the 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 collection module 120 and the first voltage collection module 130 in the conversion device 10, so as to obtain the first detection current I1 collected by the first current collection module 120 and the first detection voltage V11 collected by the first voltage collection module 130 after sending the first control signal, and determine whether the photovoltaic cell assembly PD is faulty according to the first detection voltage V11 and / or the first detection current I1.

[0071] In an optional embodiment of the present embodiment, as shown in the drawings, the photovoltaic system further comprises a controller 20 electrically connected to the conversion device 10. The controller 20 is configured to send the first control signal or the second control signal to the conversion device 10. Figure 6 ​​As shown, 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 also used to send a third control signal to the DC voltage converter A11; the DC voltage converter A11 operates in 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, so as to obtain the supply voltage Ve of the energy storage power supply device A1, i.e., V2=Ve; the conversion device 10 is specifically used to operate in buck mode according to the first control signal, and to step down the supply voltage Ve of the energy storage power supply device A1 to a first supply voltage V1.

[0072] Based on the above, the DC-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 the second supply voltage V2 according to the third control signal.

[0073] Specifically, such as Figure 7 As shown, the second controllable semiconductor power device A110 can also include four controllable semiconductor power devices, namely controllable semiconductor power devices Q5 to Q8, just like the first controllable semiconductor power device 110. The emitters of controllable semiconductor power devices Q5 and Q1 are both electrically connected to bus N1, and the collectors of controllable semiconductor power devices Q8 and 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 closed, and then controllable semiconductor power devices Q2 and Q4 are closed to reduce the supply voltage Ve of 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 closed, and then controllable semiconductor power devices Q6 and Q8 are closed to boost the output voltage Va of energy storage battery to the second supply voltage V2.

[0074] In an optional implementation of this embodiment, such as Figure 8As shown, the photovoltaic system further comprises an alternating voltage conversion device 30, the photovoltaic cell assembly PD is electrically connected with the conversion device 10 and the alternating voltage conversion device 30, the alternating voltage conversion device 30 is used to be electrically connected with the power grid B1; the alternating voltage conversion device 30 is used to convert the voltage corresponding to the maximum output power of the received photovoltaic cell assembly PD into a corresponding alternating output voltage, and transmit the alternating output voltage to the power grid B1. Wherein, the alternating voltage conversion device 30 can be a direct current- alternating current converter and other direct current- alternating current conversion devices currently available.

[0075] In an optional embodiment of the present embodiment, the photovoltaic system can further comprise a fault detection device (not shown in the figure); the fault detection device is used to collect images of the photovoltaic cell assembly PD after the conversion device 10 converts the power supply voltage output by the energy storage power supply device A1 according to the first control signal to supply power to the photovoltaic cell assembly PD, and detects whether the photovoltaic cell assembly PD is faulty according to the collected images. Wherein, the way of detecting whether the photovoltaic cell assembly PD is faulty according to the collected images is consistent with the traditional detection method, which will not be described here.

[0076] The present application provides a control method, which can be applied to the controller 20 described above, and can also be applied to the controller known in the art which can perform similar functions, such as Figure 9 As shown, the control method can comprise the following steps:

[0077] Step S900: sending a first control signal to the conversion device to make the conversion device supply power to the photovoltaic cell assembly after converting the power supply voltage output by the energy storage power supply device in response to the first control signal.

[0078] Step S910: sending a second control signal to the conversion device to make the conversion device track the maximum output power of the photovoltaic cell assembly and transmit the electrical energy generated by the photovoltaic cell assembly to the power grid at the voltage corresponding to the maximum output power in response to the second control signal.

[0079] In the control method designed above, the controller of the present scheme can transmit different control signals to the conversion device under different scenarios, so that the conversion device supplies power to the photovoltaic cell assembly after converting the power supply voltage output by the energy storage power supply device in response to the first control signal, and outputs the electrical energy generated by the photovoltaic cell assembly at the maximum output power in response to the second control signal, so that the conversion device can realize the functions of the traditional MPPT control device and the reverse power supply to the photovoltaic cell assembly, thereby omitting the traditional detection circuit inverter and saving cost.

[0080] In an optional implementation of the embodiment, before sending the first control signal, the controller can also receive a self-checking result of the energy storage device, and only after the self-checking result is fault-free, the step of sending the first control signal to the conversion device is performed, thereby avoiding the circuit failure problem caused by the fault of the energy storage device. In addition, it should be noted that in addition to receiving the self-checking result of the energy storage device, the present solution can also receive a self-checking result of the conversion device, and only when the self-checking result is fault-free, the step of sending the first control signal to the conversion device is performed. The aforementioned energy storage device is the energy storage device A1 described above, and will not be described here.

[0081] In an optional implementation of the embodiment, when the photovoltaic cell assembly is in a fault condition, the current transmitted by the conversion device to the photovoltaic cell assembly will change, and therefore, on the basis of the aforementioned conversion device comprising a first current acquisition module, the control method can further comprise the following steps as shown in Figure 10

[0082] Step S1000: Obtain a first detection current, and determine whether the photovoltaic cell assembly is faulty according to the first detection current.

[0083] Specifically, the controller can determine whether a first deviation value of the first detection current and a target current value is greater than a first preset threshold value. If the first deviation value of the first detection current and the target current value is greater than the first preset threshold value, it indicates that the first detection current produces a large change after passing through the photovoltaic assembly, and therefore, it is determined that the photovoltaic cell assembly is in a fault condition.

[0084] In an optional implementation of the embodiment, when the photovoltaic cell assembly is in a fault condition, the voltage transmitted by the conversion device to the photovoltaic cell assembly will also change, and therefore, on the basis of the aforementioned conversion device comprising a first voltage acquisition module, the control method can further comprise the following steps as shown in Figure 11

[0085] Step S1100: Obtain a first detection voltage, and determine whether the photovoltaic cell assembly is faulty according to the first detection voltage.

[0086] Specifically, the controller can determine whether a first deviation value of the first detection voltage and a target voltage value is greater than a second preset threshold value. If the first deviation value of the first detection voltage and the target current value is greater than the second preset threshold value, it indicates that the first detection voltage produces a large change after passing through the photovoltaic assembly, and therefore, it is determined that the photovoltaic cell assembly is in a fault condition.

[0087] ​​It should be noted that the present scheme can be used to determine the fault of the photovoltaic cell assembly by using the current alone, or by using the voltage alone, or by using both the current and the voltage. In addition, in addition to detecting the first detection current and / or the first detection voltage after sending the first control signal to determine whether the photovoltaic cell assembly is faulty, the present scheme can also detect the data collected by the first current collection module and the first voltage collection module after sending the second control signal to determine whether the photovoltaic cell assembly is faulty.

[0088] Figure 12 The schematic structural block diagram of the control device provided in the present application is shown, and it should be understood that the device corresponds to the method embodiment performed by the controller in Figure 9 and Figure 11 corresponding to the method embodiment performed by the controller in the foregoing, and can perform the steps involved in the foregoing method. The specific functions of the device can be referred to the description in the foregoing, and the detailed description is appropriately omitted here to avoid repetition. The device includes at least one software function module that can be stored in the memory in the form of software or firmware or solidified in the operating system (OS) of the device. Specifically, the device includes a sending module 1200 that sends a first control signal to the conversion device to make the conversion device supply power to the photovoltaic cell assembly after the conversion device converts the power supply voltage output by the energy storage power supply device in response to the first control signal, and sends a second control signal to the conversion device to make the conversion device track the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmit the electrical energy generated by the photovoltaic cell assembly to the power grid at the voltage corresponding to the maximum output power.

[0089] In the technical scheme of the embodiments of the present application, the present scheme can transmit different control signals to the conversion device in different scenarios, so that the conversion device supplies power to the photovoltaic cell assembly after converting the power supply voltage output by the energy storage power supply device in response to the first control signal, and outputs the electrical energy generated by the photovoltaic cell assembly at the maximum output power in response to the second control signal, so that 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.

[0090] According to some embodiments of the present application, the device further includes an acquisition module 1210 configured to acquire a first detection current, wherein the first detection current is obtained by the first current collection module collecting the current corresponding to the first power supply voltage, and the first power supply voltage is generated by the first controllable semiconductor power device stepping down the power supply voltage of the energy storage power supply device; and a determination module 1220 configured to determine whether the photovoltaic cell assembly is faulty according to the first detection current.

[0091] According to some embodiments of the present application, the determining module 1220 is specifically configured to determine whether the first deviation value of the first detection current from the target current value is greater than a first preset threshold value; and if the first deviation value of the first detection current from the target current value is greater than the first preset threshold value, it is determined that the photovoltaic cell assembly is faulty.

[0092] According to some embodiments of the present application, the obtaining module 1210 is further configured to obtain a first detection voltage, wherein the first detection voltage is obtained by a first voltage collection module collecting a voltage corresponding to the first power supply voltage, and the first power supply voltage is generated by a first controllable semiconductor power device stepping down a power supply voltage of the energy storage power supply device; and the determining module 1220 is configured to determine whether the photovoltaic cell assembly is faulty according to the first detection voltage.

[0093] According to some embodiments of the present application, the determining module 1220 is specifically configured to determine whether the second deviation value of the first detection voltage from the target voltage value is greater than a second preset threshold value; and if the second deviation value of the first detection voltage from the target voltage value is greater than the second preset threshold value, it is determined that the photovoltaic cell assembly is faulty.

[0094] According to some embodiments of the present application, as shown in Figure 13 The present application provides an electronic device 13, which includes 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 mechanism (not shown), 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 performed by the external terminal in any optional implementation manner, for example, steps S900 to S910: sending a first control signal to the conversion device to make the conversion device supply power to the photovoltaic cell assembly after voltage conversion of the power supply voltage output by the energy storage power supply device in response to the first control signal; and sending a second control signal to the conversion device to make the conversion device track the maximum output power of the photovoltaic cell assembly in response to the second control signal, and transmit the electrical energy generated by the photovoltaic cell assembly to the power grid at a voltage corresponding to the maximum output power.

[0095] The present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to execute the method in any optional implementation manner.

[0096] The storage medium can be implemented by any type of volatile or nonvolatile storage devices 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 storage, flash memory, magnetic disk or optical disk.

[0097] The present application provides a computer program product which, when running on a computer, causes the computer to perform the method in any of the optional implementation manners.

[0098] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; under the idea of the present application, the technical features in the above examples or different examples can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in detail for simplicity; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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 module; 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 module. And in response to a second control signal, it tracks the maximum output power of the photovoltaic cell module and outputs the electrical energy generated by the photovoltaic cell module at the maximum output power; 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 conduct the path between the energy storage device and the photovoltaic cell module in response to the first control signal, so that the power supply voltage of the energy storage device is converted into a first power supply voltage and transmitted to the photovoltaic cell module; the MPPT control device further includes a first current acquisition module connected to the path; the MPPT control device further includes a first voltage acquisition module connected to the path. The first controllable semiconductor power device includes four controllable semiconductor power devices, namely controllable semiconductor power device Q1, controllable semiconductor power device Q2, controllable semiconductor power device Q3, and controllable semiconductor power device Q4. The emitter of controllable semiconductor power device Q1 is connected to bus N1, the collector of controllable semiconductor power device Q1 is connected to the emitter of controllable semiconductor power device Q2, the collector of controllable semiconductor power device Q2 is connected to the emitter of controllable semiconductor power device Q3, and the collector of controllable semiconductor power device Q2 is electrically connected to the first voltage acquisition module through the first current acquisition module. The emitter of controllable semiconductor power device Q4 is connected to the collector of controllable semiconductor power device Q3, and the collector of controllable semiconductor power device Q4 is connected to bus N2. The emitter of the controllable semiconductor power device Q2 is connected to the positive terminal of capacitor C1, the collector of the controllable semiconductor power device Q3 is connected to the negative terminal of capacitor C1, the cathode of diode D1 is connected to the positive terminal of capacitor C1, the anode of diode D1 is connected to the cathode of diode D2, and the anode of diode D2 is connected to the negative terminal of capacitor C1. The positive terminal of capacitor C2 is connected to bus N1, the negative terminal of capacitor C2 is connected to the positive terminal of capacitor C3 and the anode of diode D1, and the negative terminal of capacitor C3 is connected to bus N2.

2. The conversion device according to claim 1, characterized in that, The first current acquisition module is used to detect the current of the first power supply voltage to obtain a first detection current; The MPPT control device is also used to determine whether the photovoltaic cell module is faulty based on the first detection current.

3. The conversion device according to claim 1, characterized in that, The first voltage acquisition module is used to detect the first power supply voltage and obtain the first detection voltage; The MPPT control device is also used to determine whether the photovoltaic cell module is faulty based on the first detection voltage.

4. A photovoltaic system, characterized in that, The photovoltaic system includes the conversion device according to any one of claims 1-3, the photovoltaic cell module, and the energy storage device, wherein the photovoltaic cell module is electrically connected to the energy storage device through the conversion device.

5. The photovoltaic system according to claim 4, characterized in that, The photovoltaic system also includes a controller; The controller is electrically connected to the conversion device; The controller is used to send the first control signal to the conversion device.

6. The photovoltaic system according to claim 5, characterized in that, in, The energy storage device includes an energy storage battery and a DC-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 also used to send a third control signal to the DC voltage converter; The DC-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, so as to obtain the supply voltage of the energy storage device; The conversion device is specifically used to step down the power supply voltage of the energy storage device to the first power supply voltage.

7. The photovoltaic system according to claim 6, characterized in that, The DC-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 through the second voltage acquisition module, and the second current acquisition module is electrically connected to the conversion device through 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 used to boost the output voltage of the energy storage battery to the second supply voltage in response to the third control signal.

8. The photovoltaic system according to claim 5, characterized in that, The controller is further configured to, after sending the first control signal, acquire a first detection voltage and / or a first detection current, wherein the first detection current is obtained by the first current acquisition module acquiring the current corresponding to the first power supply voltage, and the first detection voltage is obtained by the first voltage acquisition module acquiring the voltage corresponding to the first power supply voltage; and determine whether the photovoltaic cell module is faulty based on the first detection voltage and / or the first detection current.

9. The photovoltaic system according to claim 4, characterized in that, The photovoltaic system also includes an AC voltage conversion device; the photovoltaic cell module is electrically connected to the AC voltage conversion device through 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 module into a corresponding AC output voltage, and transmit the AC output voltage to the power grid.

10. The photovoltaic system according to claim 4, characterized in that, The photovoltaic system also includes a fault detection device, which is used to collect an image of the photovoltaic cell module after the conversion device converts the power supply voltage output by the energy storage device according to the first control signal and supplies power to the photovoltaic cell module, and to detect whether the photovoltaic cell module is faulty based on the collected image.

11. A control method, characterized in that, The control method is used to control a conversion device, which is used to connect an energy storage device and a photovoltaic cell module; the method includes: A first control signal is sent to the conversion device so that the conversion device, in response to the first control signal, performs voltage conversion on the power supply voltage output by the energy storage device to supply power to the photovoltaic cell module; The system sends a second control signal to the conversion device, causing the conversion device to track the maximum output power of the photovoltaic module in response to the second control signal, and transmit the electrical energy generated by the photovoltaic module to the grid at the voltage corresponding to the maximum output power; wherein, 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 conduct the path between the energy storage device and the photovoltaic module in response to the first control signal, so that the supply voltage of the energy storage device is converted to a first supply voltage and transmitted to the photovoltaic module; the MPPT control device also includes a first current acquisition module connected to the path; the MPPT control device also includes a first voltage acquisition module connected to the path; the first controllable semiconductor power device includes four controllable semiconductor power devices, namely controllable semiconductor power device Q1, controllable semiconductor power device Q2, controllable semiconductor power device Q3 and controllable semiconductor power device Q4, and the... The emitter of controllable semiconductor power device Q1 is connected to bus N1. The collector of controllable semiconductor power device Q1 is connected to the emitter of controllable semiconductor power device Q2. The collector of controllable semiconductor power device Q2 is connected to the emitter of controllable semiconductor power device Q3. The collector of controllable semiconductor power device Q2 is electrically connected to the first voltage acquisition module through the first current acquisition module. The emitter of controllable semiconductor power device Q4 is connected to the collector of controllable semiconductor power device Q3. The collector of the power device Q4 is connected to bus N2; the emitter of the controllable semiconductor power device Q2 is connected to the positive terminal of capacitor C1; the collector of the controllable semiconductor power device Q3 is connected to the negative terminal of capacitor C1; the cathode of diode D1 is connected to the positive terminal of capacitor C1; the anode of diode D1 is connected to the cathode of diode D2; the anode of diode D2 is connected to the negative terminal of capacitor C1; the positive terminal of capacitor C2 is connected to bus N1; the negative terminal of capacitor C2 is connected to the positive terminal of capacitor C3 and the anode of diode D1; and the negative terminal of capacitor C3 is connected to bus N2.

12. The method according to claim 11, characterized in that, Before sending the first control signal to the conversion device, the method further includes: The self-test result of the energy storage device is received, and after the self-test result is that there is no fault, the step of sending a first control signal to the conversion device is executed.

13. The method according to claim 11, characterized in that, After sending a first control signal to the conversion device, the method further includes: A first detection current is obtained; wherein, the first detection current is obtained by the first current acquisition module by acquiring the current corresponding to the first supply voltage, and the first supply voltage is generated by the first controllable semiconductor power device after stepping down the supply voltage of the energy storage device; The photovoltaic cell module is determined to be faulty based on the first detection current.

14. The method according to claim 13, characterized in that, The step of determining whether the photovoltaic cell module is faulty based on the first detected current includes: Determine whether the first deviation value between the first detected current and the target current value is greater than a first preset threshold; If the first deviation between the first detected current and the target current value is greater than the first preset threshold, then the photovoltaic cell module is determined to be faulty.

15. The method according to claim 11, characterized in that, After sending a first control signal to the conversion device, the method further includes: A first detection voltage is obtained; wherein the first detection voltage is obtained by the first voltage acquisition module by acquiring the voltage corresponding to the first power supply voltage, and the first power supply voltage is generated by the first controllable semiconductor power device after stepping down the power supply voltage of the energy storage device. The photovoltaic cell module is determined to be faulty based on the first detection voltage.

16. The method according to claim 15, characterized in that, The step of determining whether the photovoltaic cell module is faulty based on the first detection voltage includes: Determine whether the second deviation value between the first detected voltage and the target voltage value is greater than a second preset threshold; If the second deviation between the first detected voltage and the target voltage value is greater than the second preset threshold, then the photovoltaic cell module is determined to be faulty.

17. The method according to claim 11, characterized in that, The energy storage device includes an energy storage battery and a DC-DC voltage converter, the conversion device being electrically connected to the energy storage battery via the DC-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.

18. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 11 to 17.

19. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 11 to 17.

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