Photovoltaic system and operation method thereof

Abstract

The invention relates to a photovoltaic system and an operation method thereof.The output end of a photovoltaic panel is connected with a load device and a switching device which are connected in series, and under the condition that a power supply instruction is received to start power supply for electric equipment, the ratio of an output power parameter to an output electric parameter of the photovoltaic panel is determined firstly; and then the connection state of the photovoltaic panel and the micro inverter is adjusted in combination with the ratio of the output power parameter to the output electrical parameter, that is, whether the micro inverter is connected to the photovoltaic panel is determined in combination with the ratio of the output power parameter to the output electrical parameter. According to the scheme, the output of the photovoltaic panel can be analyzed, and whether the photovoltaic panel is controlled to be connected to the micro inverter to operate or not is determined according to the actual output condition of the photovoltaic panel. Therefore, even if the specification of the photovoltaic panel is not known, or the moment of the photovoltaic panel is not known to be daytime or night, the access control of the micro inverter and the photovoltaic panel can still be accurately realized, so that the access reliability of the photovoltaic panel is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a photovoltaic system and an operating method thereof. Background Art

[0002] With the development of new energy technologies and the promotion of energy conservation and emission reduction, photovoltaic power generation has become widely used due to its clean and pollution-free environment, short construction period, long service life, and low maintenance costs. In photovoltaic power generation technology, photovoltaic panels are generally connected to the AC power grid through a micro photovoltaic grid-connected inverter to provide power to the AC grid.

[0003] However, in the related art, the micro photovoltaic grid-connected inverter does not know the specifications of the photovoltaic panels, resulting in poor access reliability of the photovoltaic panels. Summary of the Invention

[0004] Based on this, it is necessary to provide a photovoltaic system and an operating method thereof to solve the problem of poor access reliability of photovoltaic panels.

[0005] A method for operating a photovoltaic system, the photovoltaic system comprising a photovoltaic panel, a switching device, a load device, and a micro-inverter, wherein an output end of the photovoltaic panel is connected to a first end of the load device and the micro-inverter, a second end of the load device is connected to a first end of the switching device, and a second end of the switching device is grounded; upon receiving a power supply instruction, determining an output power parameter and an output electrical parameter ratio of the photovoltaic panel; and adjusting a connection state between the photovoltaic panel and the micro-inverter based on the output power parameter and the output electrical parameter ratio.

[0006] A photovoltaic system comprises: a load device, a microinverter, a photovoltaic panel, a voltage collector, a switch device, and a controller, wherein the microinverter is used to connect to an electrical device; the output end of the photovoltaic panel is connected to the first end of the load device and the microinverter; the voltage collector is arranged at the output end of the photovoltaic panel; the first end of the switch device is connected to the second end of the load device, and the second end of the switch device is grounded; and the controller is connected to the voltage collector and the third end of the switch device, and is used to implement the steps of the above-mentioned operating method.

[0007] The above-mentioned photovoltaic system and its operating method employ a series connection between a load device and a switching device at the output end of a photovoltaic panel. Upon receiving a power supply command to start powering a consumer, the system first determines the output power parameter and output electrical parameter ratio of the photovoltaic panel. Then, based on these parameters, the system adjusts the connection between the photovoltaic panel and the microinverter. Specifically, the system determines whether the microinverter is connected to the photovoltaic panel based on the output power parameter and output electrical parameter ratio. This solution analyzes the output of the photovoltaic panel and, based on the panel's actual output, determines whether the panel should be connected to the microinverter. This allows precise control of the microinverter's connection to the photovoltaic panel even without knowing the panel's specifications or whether the panel is operating during the day or at night, effectively improving panel connection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 This is a schematic diagram of the photovoltaic system structure in one embodiment of the present application;

[0010] Figure 2 This is a flow chart of a method for operating a photovoltaic system in one embodiment of the present application;

[0011] Figure 3 This is a schematic diagram of the process of analyzing the output power parameter and the output voltage ratio parameter in one embodiment of the present application;

[0012] Figure 4 Schematic diagram of the analysis process of the first power parameter, the second power parameter and the output voltage ratio parameter in one embodiment of the present application;

[0013] Figure 5 This is a flow chart of an operating method of a photovoltaic system in another embodiment of the present application;

[0014] Figure 6 This is a schematic diagram of a threshold determination process in an embodiment of the present application;

[0015] Figure 7 This is a schematic diagram of the output power parameter and output voltage ratio parameter analysis process in another embodiment of the present application;

[0016] Figure 8 This is a schematic diagram of the photovoltaic system structure in another embodiment of the present application. DETAILED DESCRIPTION

[0017] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0018] The photovoltaic system operation method provided in the embodiment of the present application is applied in the photovoltaic system. Figure 1 The photovoltaic system includes a photovoltaic panel 101 and a micro-inverter 102. The output end of the photovoltaic panel 101 is connected to the micro-inverter 102, which is in turn connected to electrical equipment. The direct current energy generated by the photovoltaic panel 101 through the photoelectric effect is converted by the micro-inverter 102 and supplied to the electrical equipment (such as various household load devices) in the form of alternating current. Furthermore, in one embodiment, a voltage collector 103 is provided at the output end of the photovoltaic panel 101, and a load device R1 and a switch device Q1 are sequentially connected to the output end of the photovoltaic panel 101. When the switch device Q1 is off, the load device R1 is not connected to the photovoltaic panel 101. At this time, the voltage of the photovoltaic panel 101 will not be divided by the load device R1. When the switch device Q1 is closed, the voltage of the photovoltaic panel 101 will be divided by the load device R1, and the voltage value at the output end of the photovoltaic panel 101 will change to a certain extent.

[0019] The controller of the photovoltaic system is connected to the switching device Q1 and the voltage collector 103 respectively. The controller can not only control the on and off of the switching device Q1, but also obtain the output of the photovoltaic panel 101 through the voltage collector 103 when the switching device Q1 is turned on or off, thereby realizing the operation method of the photovoltaic system provided in the embodiment of the present application.

[0020] The present application provides an operating method of a photovoltaic system, wherein the photovoltaic system includes a photovoltaic panel, a switch device, a load device, and a micro-inverter, wherein the output end of the photovoltaic panel is connected to the first end of the load device, the second end of the load device is connected to the first end of the switch device, and the second end of the switch device is grounded. Figure 2 , the method includes step 202 and step 204.

[0021] Step 202: upon receiving a power supply instruction, determining the output power parameter and the ratio of the output electrical parameter of the photovoltaic panel.

[0022] Specifically, a switch device is a device that can perform a switching function under the control of a controller or manual operation by the user. A photovoltaic panel is a photoelectric conversion device that can convert solar energy or light energy into electrical energy. A load device is a device that can consume electrical energy as a load.

[0023] Output power parameters refer to parameters related to the output power of a photovoltaic panel. These parameters can be the output power value or the change in output power when the panel is in different output states, with no specific restrictions. The output electrical parameter ratio is the ratio of electrical parameters collected from the output of the photovoltaic panel when the panel is in different output states. Specifically, the different output states of a photovoltaic panel are not unique and can be either connected to a load device or not connected to a load device. The output electrical parameter ratio can be the ratio of output voltages.

[0024] It is understood that the specific types of load devices and switching devices are not limited and can be selected based on actual needs. For example, in a more detailed embodiment, the load device can be a resistor, which can be a single resistor or a resistor assembly formed by multiple resistors connected in series and / or in parallel. In another embodiment, the load device can be an energy-consuming device such as an indicator light. The switching device can be a power switch (such as a triode or field-effect transistor) or a relay.

[0025] The output of the photovoltaic panel is connected to a microinverter, which in turn supplies power to the consumer. Furthermore, a series connection of a switch and a load device is placed at the output of the photovoltaic panel. During operation, the panel switches between different output states by controlling the disconnection and connection of the switch.

[0026] The operating method provided in the embodiments of this application essentially detects the output of the photovoltaic panel, so that after the photovoltaic panel is connected to the microinverter, it can provide appropriate power to the electrical equipment and maintain stable operation of the electrical equipment. Therefore, the controller needs to monitor the operating requirements of the photovoltaic system. When it detects and receives a power supply instruction, that is, the photovoltaic panel needs to charge or supply power to the electrical equipment, it is considered that the photovoltaic system has an output detection requirement. At this time, it will start to obtain the output power parameter and the output electrical parameter ratio.

[0027] Step 204 : adjusting the connection state between the photovoltaic panel and the micro-inverter according to the ratio of the output power parameter to the output electrical parameter.

[0028] Specifically, the connection between the PV panel and the microinverter can be in two different states: connected or disconnected. After determining the ratio of the output power parameter to the output electrical parameter, the controller uses this ratio as a basis for determining whether the microinverter can be connected to the PV panel.

[0029] The above-mentioned photovoltaic system operating method connects a load device and a switching device in series to the output end of the photovoltaic panel. Upon receiving a power supply command to start powering the electrical device, the system first determines the output power parameter and output electrical parameter ratio of the photovoltaic panel. Then, based on these parameters, the system adjusts the connection between the photovoltaic panel and the microinverter. Specifically, the system determines whether to connect the microinverter to the photovoltaic panel based on the output power parameter and output electrical parameter ratio. This solution analyzes the output of the photovoltaic panel and, based on the panel's actual output, determines whether to control the panel's connection to the microinverter. This allows precise control of the connection between the microinverter and the photovoltaic panel even without knowing the panel's specifications or whether the panel is operating during the day or at night, effectively improving the panel's connection reliability.

[0030] See also Figure 3 In one embodiment, determining the ratio of the output power parameter and the output electrical parameter of the photovoltaic panel includes: step 302, step 304 and step 306.

[0031] Step 302 : When the switch device is disconnected, obtain a first output voltage of a photovoltaic panel of the photovoltaic system.

[0032] Step 304 : When the switch device is closed, obtain a second output voltage of the photovoltaic panel.

[0033] Step 306 : Determine the output power parameter and the output electrical parameter ratio according to the first output voltage, the second output voltage, and the resistance value of the load device.

[0034] Specifically, the resistance value of the load device, i.e., the equivalent resistance value of the load device, may vary depending on the load device. This resistance value may be stored in a preset form in the controller. In the embodiment of the present application, the output end of the photovoltaic panel is connected to a microinverter, which is then connected to the electrical equipment for power supply. Furthermore, a series-connected switch device and a load device are provided at the output end of the photovoltaic panel. During operation of the photovoltaic panel, the first output voltage of the photovoltaic panel can be collected at the output end of the photovoltaic panel by controlling the disconnection of the switch device.

[0035] It should be noted that there is no single method for disconnecting a switching device; the corresponding operation varies depending on the type of switching device. In one embodiment, taking the switching device as a power switch or relay, the switching device is further connected to a controller. When the controller detects a need to monitor the output of the photovoltaic panel, the controller controls the switching device to turn on and off. In another embodiment, the switching device can also be a manual switch. When a need to monitor the output of the photovoltaic panel is detected, the user can manually control the switching device to turn on and off. This is not a specific limitation.

[0036] There are many ways to obtain the first output voltage. In one embodiment, a voltage collector can be provided at the output of the photovoltaic panel. This voltage collector is connected to the controller via wired or wireless communication and collects the voltage when the switching device is disconnected. The obtained first output voltage is then sent to the controller. In another embodiment, the controller can be integrated with a voltage collection function and directly connected to the output of the photovoltaic panel to implement voltage collection at the output of the photovoltaic panel.

[0037] As shown above, a switch device and a load device are provided at the output end of the photovoltaic panel. After the user manually opens the switch device, or the controller controls the switch device to open, and the first output voltage is collected, the switch device can be closed manually by the user or automatically by the controller. When the switch device is closed, the second output voltage of the photovoltaic panel can be collected by the voltage collector, or directly collected by the controller.

[0038] After obtaining the first output voltage and the second output voltage, the controller will retrieve the resistance value of the load device and analyze and calculate the three together to obtain the output power parameter and the output electrical parameter ratio.

[0039] The above solution obtains the first output voltage and the second output voltage of the photovoltaic panel according to the on-off state of the switching device, and calculates the ratio of the output power parameter and the output electrical parameter in combination with the resistance value of the load device, which has high calculation accuracy.

[0040] See also Figure 4 In one embodiment, step 306 includes step 402 , step 404 , and step 406 .

[0041] Step 402: Determine a first power parameter according to the second output voltage and the resistance value of the load device.

[0042] Step 404: Determine a second power parameter according to the first output voltage, the second output voltage, and the resistance value.

[0043] Step 406: Determine an output electrical parameter ratio based on the second output voltage and the first output voltage.

[0044] Specifically, after the switching device is opened and closed and the first output voltage and the second output voltage are respectively collected and obtained, the controller will analyze the first output voltage and the second output voltage to determine the first power parameter, the second power parameter and the output electrical parameter ratio required when the photovoltaic panel performs output detection.

[0045] Among them, the output power parameter refers to the parameter obtained by analyzing the first output voltage and / or the second output voltage, which is used to characterize the output power of the photovoltaic panel; the output electrical parameter ratio refers to the parameter used to characterize the change between the first output voltage and the second output voltage.

[0046] Furthermore, the first power parameter is determined in combination with the second output voltage and the resistance value of the load device, so as to characterize the power generated by the output of the photovoltaic panel in the load device after the load device is connected; the second power parameter is determined by analyzing the voltage difference between the first output voltage and the second output voltage, as well as the resistance value, so as to characterize the power change caused after the load device is connected.

[0047] During photovoltaic panel operation, the output voltage of the photovoltaic panel is divided by the load device through the on-off switching of the switching device, and the power at the photovoltaic panel output will also change accordingly. Therefore, the solution of this embodiment needs to combine the first output voltage, the second output voltage, and the resistance value of the load device to determine the output power parameter to ensure that the output power parameter can reasonably represent the output status of the photovoltaic panel.

[0048] Specifically, the power parameter of the photovoltaic system's load device in an operating state when the switch device is on can be calculated by combining the second output voltage and the resistance value of the load device, i.e., the first power parameter. The change in photovoltaic system power when the switch device is on relative to when the switch device is off can be calculated by combining the first output voltage, the second output voltage, and the resistance value of the load device, i.e., the second power parameter.

[0049] The above solution uses the first power parameter, the second power parameter and the ratio of the output electrical parameter to detect the output of the photovoltaic panel, effectively improving the accuracy of the photovoltaic panel connection judgment.

[0050] See also Figure 5 , in one embodiment, step 204 includes step 502 .

[0051] Step 502 : When the ratio of the output power parameter to the output electrical parameter meets the preset parameter conditions, and the first output voltage and the second output voltage meet the preset output conditions, control the photovoltaic panel to connect to the micro-inverter for operation.

[0052] Specifically, the preset parameter conditions are preset conditions that must be met for the ratio of the output power parameter to the output electrical parameter when the photovoltaic panel is connected to the microinverter to power the electrical device. The preset output conditions are preset conditions that must be met for the first output voltage and the second output voltage when the photovoltaic panel is connected to the microinverter to power the electrical device.

[0053] The controller pre-stores preset parameter conditions and preset output conditions. After analyzing the first and second output voltages to determine the ratio of the output power parameter to the output electrical parameter, the controller determines whether the ratio of the output power parameter to the output electrical parameter meets the preset parameter conditions. Furthermore, after obtaining the first and second output voltages, the controller further determines whether the first and second output voltages meet the preset output conditions. Ultimately, if the ratio of the output power parameter to the output electrical parameter meets the preset parameter conditions, and the first and second output voltages meet the preset output conditions, the controller controls the photovoltaic panel to connect to the microinverter, which then provides electrical energy to the electrical device. If the ratio of the output power parameter to the output electrical parameter does not meet the preset parameter conditions, and / or the first and second output voltages do not meet the preset output conditions, the controller will not control the photovoltaic panel to connect to the microinverter for operation.

[0054] Through the above scheme, the output power parameter and the output electrical parameter ratio are determined based on the first output voltage, the second output voltage and the resistance value of the load device. When the output power parameter and the output electrical parameter ratio, as well as the first output voltage and the second output voltage, respectively meet certain conditions, the photovoltaic panel is controlled to be connected to the micro-inverter for operation, which has high access control accuracy.

[0055] It should be noted that, in one embodiment, the controller's determination of whether the first and second output voltages meet the preset output condition can be performed after the controller determines whether the ratio of the output power parameter to the output electrical parameter meets the preset parameter condition. In this case, the determination can be performed only if the controller determines that the ratio of the output power parameter to the output electrical parameter meets the preset parameter condition; otherwise, there is no need to determine whether the first and second output voltages meet the preset output condition.

[0056] In another embodiment, the process may be performed before the controller determines whether the ratio of the output power parameter to the output electrical parameter satisfies the preset parameter condition. Accordingly, in this case, the controller needs to determine whether the first output voltage and the second output voltage satisfy the preset output condition before determining whether the ratio of the output power parameter to the output electrical parameter satisfies the preset parameter condition. Otherwise, there is no need to determine whether the ratio of the output power parameter to the output electrical parameter satisfies the preset parameter condition.

[0057] Furthermore, in other embodiments, the process may be performed before the controller determines the ratio of the output power parameter to the output electrical parameter based on the first output voltage and the second output voltage. Accordingly, in this case, the controller needs to determine the ratio of the output power parameter to the output electrical parameter only if the first output voltage and the second output voltage meet the preset output conditions. Otherwise, there is no need to determine the ratio of the output power parameter to the output electrical parameter.

[0058] It should be noted that the calculation method of the first power parameter and the second power parameter is not unique. In a more detailed embodiment, the calculation method of the first power parameter is: b^2 / R1=f, where f represents the first power parameter, b represents the second output voltage, and R1 represents the resistance value of the load device. That is, the first power parameter is obtained by dividing the square of the second output voltage by the resistance value.

[0059] The second power parameter is calculated as follows: (ab)^2 / R1=g, where g represents the second power parameter, a represents the first output voltage, b represents the second output voltage, and R1 represents the resistance value of the load device. That is, the second power parameter is obtained by dividing the square of the voltage difference between the first output voltage and the second output voltage by the resistance value.

[0060] In more detail, in one embodiment, the output electrical parameter ratio is calculated as: b / a=h, where represents the output electrical parameter ratio, a represents the first output voltage, and b represents the second output voltage, that is, the ratio of the second output voltage to the first output voltage is used as the output electrical parameter ratio.

[0061] In one embodiment, the output power parameter and the output electrical parameter ratio meet preset parameter conditions, including: the first power parameter meets the first parameter condition, the second power parameter meets the second power parameter condition, and the output electrical parameter ratio meets the third parameter condition.

[0062] Specifically, the solution of this embodiment corresponds to the output power parameters including the first power parameter and the second power parameter. A corresponding parameter condition is set for each parameter in the controller. When determining whether the output power parameter and the output electrical parameter ratio meet the preset parameter condition, it is necessary to sequentially determine whether the first power parameter meets the first parameter condition, whether the second power parameter meets the second power parameter condition, and whether the output electrical parameter ratio meets the third parameter condition. Ultimately, if all three parameters meet the corresponding parameter conditions simultaneously, it is considered that the output power parameter and the output electrical parameter ratio meet the preset parameter condition; otherwise, it is considered that the output power parameter and the output electrical parameter ratio do not meet the preset parameter condition.

[0063] This solution determines whether the output power parameter and the output electrical parameter ratio meet the preset parameter conditions by respectively judging whether the first power parameter meets the first parameter condition, whether the second power parameter meets the second power parameter condition, and whether the output electrical parameter ratio meets the third parameter condition, and has high judgment accuracy.

[0064] In one embodiment, the operating method includes at least one of the following:

[0065] Item 1: The first power parameter satisfies a first parameter condition, including: the first power parameter is greater than or equal to a first preset power threshold.

[0066] The second item: the second power parameter satisfies a second power parameter condition, including: the second power parameter is less than or equal to a second preset power threshold.

[0067] Item 3: The output electrical parameter ratio satisfies a third parameter condition, including: the output electrical parameter ratio is greater than or equal to a preset ratio threshold.

[0068] Specifically, the solution of this embodiment sets a first preset power threshold, a second preset power threshold, and a preset ratio threshold for the first power parameter, the second power parameter, and the output electrical parameter ratio, respectively. Therefore, during actual operation, it is possible to determine whether the first power parameter satisfies the first parameter condition by determining whether the first power parameter is greater than or equal to the first preset power threshold. And / or, it is possible to determine whether the second power parameter satisfies the second power parameter condition by determining whether the second power parameter is less than or equal to the second preset power threshold. And / or, it is possible to determine whether the output electrical parameter ratio satisfies the third parameter condition by determining whether the output electrical parameter ratio is greater than or equal to the preset ratio threshold.

[0069] In more detail, in one embodiment, after the controller obtains the first power parameter, the second power parameter and the output electrical parameter ratio, it compares and analyzes the first power parameter with the first preset power threshold, compares and analyzes the second power parameter with the second preset power threshold, and compares and analyzes the output electrical parameter ratio with the preset ratio threshold, so as to realize the analysis and judgment of whether the output power parameter and the output electrical parameter ratio meet the preset parameter conditions.

[0070] The above scheme sets different thresholds for the first power parameter, the second power parameter and the output electrical parameter ratio, respectively, and determines whether the corresponding parameter conditions are met by comparing with the thresholds. This scheme has the advantages of simple judgment method and high judgment efficiency, and can effectively improve the operating efficiency of photovoltaic panels.

[0071] See also Figure 6 In one embodiment, before step 204 , the method further includes steps 602 , 604 , 606 and 608 .

[0072] Step 602 : Acquire the minimum system power consumption and the minimum load power consumption of the photovoltaic system, as well as the open circuit voltage and the operating voltage of the photovoltaic panel.

[0073] Step 604: Determine a first preset power threshold according to the system minimum power consumption and the load minimum power consumption.

[0074] Step 606: Determine a second preset power threshold according to the open circuit voltage.

[0075] Step 608: Determine a preset ratio threshold value according to the open circuit voltage and the operating voltage.

[0076] Specifically, steps 602-608 may be executed between steps 202-204, or before step 202, without specific limitation. It should be noted that, in a more detailed embodiment, since the photovoltaic system is connected and the electrical equipment is fixed, the system minimum power consumption and the load minimum power consumption of the photovoltaic system, as well as the open-circuit voltage and the operating voltage of the photovoltaic panel, will remain substantially consistent. Therefore, when the operating method of the present application is first executed, the operations of steps 602-608 may be executed, and the determined first preset power threshold, second preset power threshold, and preset ratio threshold may be stored in the controller, which can then be directly called upon subsequent executions of the operating method. Accordingly, when the electrical equipment or photovoltaic panel in the photovoltaic system changes, the operations of steps 602-608 need to be re-executed to update the first preset power threshold, second preset power threshold, and preset ratio threshold.

[0077] When the controller has an output detection requirement for the photovoltaic panel, the controller retrieves the system minimum power consumption and the load minimum power consumption of the photovoltaic system, as well as the open circuit voltage and the operating voltage of the photovoltaic panel, and analyzes the system minimum power consumption and the load minimum power consumption to determine a first preset power threshold, determines a second preset power threshold in combination with the open circuit voltage, and determines a preset ratio threshold in combination with the open circuit voltage and the operating voltage.

[0078] In more detail, in one embodiment, the first preset power threshold is: the minimum power consumption of the system + the minimum power consumption of the load + the fixed power value, wherein the value of the fixed power value is not unique, and 10W, 20W or 30W can be selected based on actual needs, without specific limitation.

[0079] The second preset power threshold is determined in combination with the open circuit voltage as follows: (kk*0.5)^2 / R1, where * represents multiplication, ^ represents square, k represents the open circuit voltage, and R1 represents the resistance value of the load device. That is, the square of (kk*0.5) is divided by the resistance value to obtain the second preset power threshold.

[0080] The preset ratio threshold is related to the open circuit voltage and the operating voltage, and can be obtained by multiplying the open circuit voltage and the operating voltage by a corresponding ratio. The ratio can be set according to actual needs. For example, in a more detailed embodiment, the threshold ratio threshold is 0.7, 0.8, or 0.9, etc., which is not limited to this.

[0081] The above scheme combines the minimum power consumption of the system, the minimum power consumption of the load, the open-circuit voltage and the operating voltage to determine the first preset power threshold, the second preset power threshold and the preset ratio threshold. The analysis and judgment of the output power parameter and the output electrical parameter ratio are combined with the actual state of the photovoltaic system to ensure the accuracy of the preset parameter conditions.

[0082] In one embodiment, the first output voltage and the second output voltage meet a preset output condition, including: the first output voltage and the second output voltage are both within a preset input voltage range.

[0083] Specifically, the preset input voltage range is a preset voltage range required for normal operation of electrical equipment connected to the photovoltaic system. In this embodiment, after obtaining the first and second output voltages, the controller compares and analyzes the first and second output voltages with the preset input voltage range. If both the first and second output voltages are within the preset input voltage range, the controller determines that the first and second output voltages meet the preset output conditions.

[0084] It should be noted that the preset input voltage range is not unique. Depending on the type of electrical equipment connected to the microinverter in actual scenarios, the preset input voltage range may also vary. Therefore, the preset input voltage range can be set based on the actual scenario. For example, in a more detailed embodiment, the preset input voltage range can be set to 80V-100V.

[0085] In this way, when the first output voltage and the second output voltage are both within the preset input voltage range, it is considered that the preset output condition is met, thereby ensuring that the output voltage of the photovoltaic panel can meet the power demand of the electrical equipment.

[0086] See also Figure 7 In one embodiment, before step 302 , the method further includes steps 702 and 704 .

[0087] Step 702: Obtain the output voltage of the photovoltaic panel.

[0088] Step 704 : When the output voltage meets the preset working condition, verify the working state of the switch device.

[0089] Specifically, if the power supply command analysis indicates a need for photovoltaic panel output detection, the controller first obtains and analyzes the panel's output voltage. If the output voltage meets preset operating conditions (specifically, the output voltage may be greater than or equal to a preset operating voltage threshold), the controller further detects the operating status of the switching device. Finally, based on the operating status of the switching device, it obtains a first output voltage and a second output voltage, respectively, to determine whether the photovoltaic panel is connected.

[0090] In the above solution, after the controller receives the power supply instruction, it performs analysis and judgment on whether the photovoltaic panel is connected, ensuring that the photovoltaic panel supplies power in a state that matches the electrical equipment, thereby improving the power supply reliability of the photovoltaic panel.

[0091] In one embodiment, controlling the photovoltaic panel to connect to the micro-inverter for operation includes: controlling switch devices respectively connected to the photovoltaic panel and the micro-inverter to turn on.

[0092] Specifically, the microinverter is used to connect to electrical devices. In this embodiment, a switch device is provided between the photovoltaic panel and the microinverter. This switch device is connected to a controller, which controls the switching device to connect and disconnect the photovoltaic panel from the microinverter. When the photovoltaic panel is connected to the microinverter, the microinverter can output power to the electrical device. When the photovoltaic panel is not connected to the microinverter, the electrical device is de-energized and ceases operation.

[0093] It should be noted that the specific type of switching device is not unique, and the selection of the corresponding switching device may vary depending on the model of the photovoltaic panel. For example, in one embodiment, a DC converter can be used as the switching device, and the connection between the photovoltaic panel and the microinverter can be controlled by controlling the start and stop of the DC converter. In other embodiments, a power switch or relay can also be used as the switching device. The selection can be based on the actual scenario and is not limited here.

[0094] The above solution realizes access control of the photovoltaic panel and the microinverter by controlling the switch device provided between the photovoltaic panel and the microinverter, thereby effectively improving the access control reliability of the photovoltaic panel.

[0095] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with more detailed embodiments.

[0096] First, when the controller receives a power supply command, it checks whether the output voltage of the photovoltaic panel meets the preset operating conditions, that is, whether the output voltage is greater than the preset operating voltage threshold. If the preset operating conditions are met, the controller further checks the status of the switching device. If the switching device is open, the controller obtains the current first output voltage a of the photovoltaic panel. Then, the controller controls the switching device to close and obtain the second output voltage b of the photovoltaic panel.

[0097] After that, the controller calculates the first power parameter f, the second power parameter g and the output electrical parameter ratio h based on the first output voltage a, the second output voltage b and the resistance value R1 of the load device (which can be a resistor), specifically: b^2 / R1=f; (ab)^2 / R1=g; b / a=h.

[0098] The system then determines whether f is greater than or equal to a first preset power threshold (which can be the system's minimum power consumption + the load's minimum power consumption + a fixed power value); whether g is less than or equal to a second preset power threshold, which can be (kk*0.5)^2 / R1; whether the output electrical parameter ratio is greater than or equal to a preset ratio threshold (derived by multiplying the open-circuit voltage and the operating voltage by the corresponding ratio, which can be 0.8); and whether the first output voltage a and the second output voltage b are both within a preset input voltage range. If all of these determinations are positive, the output power parameter and the output electrical parameter ratio are deemed to meet the preset parameter conditions, and the first output voltage and the second output voltage meet the preset output conditions. The controller then controls the switch device to conduct or turn on, and the electrical energy output by the photovoltaic panel is transmitted to the power-consuming device through the switch device and the microinverter.

[0099] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0100] See also Figure 1 The present application also provides a photovoltaic system, including: a load device R1, a micro-inverter 102, a photovoltaic panel 101, a voltage collector 103, a switching device Q1 and a controller (not shown), wherein the micro-inverter 102 is used to connect to an electrical device; the output end of the photovoltaic panel 101 is connected to the first end of the load device R1 and the micro-inverter 102; the voltage collector 103 is arranged at the output end of the photovoltaic panel 101; the first end of the switching device Q1 is connected to the second end of the load device R1, and the second end of the switching device Q1 is grounded; the controller is connected to the voltage collector 103 and the third end of the switching device Q1, and is used to implement the steps of the above-mentioned operating method.

[0101] Specifically, the specific implementation of the operating method is as described in the various embodiments above and will not be further elaborated here. The photovoltaic system described above has a load device R1 and a switch device Q1 connected in series at the output end of the photovoltaic panel 101. Upon receiving a power supply instruction to start powering the electrical device, the system first determines the output power parameter and output electrical parameter ratio of the photovoltaic panel 101. Then, based on the output power parameter and output electrical parameter ratio, the system adjusts the connection between the photovoltaic panel 101 and the microinverter 102. Specifically, based on the output power parameter and output electrical parameter ratio, the system determines whether the microinverter 102 is connected to the photovoltaic panel 101. This solution analyzes the output of the photovoltaic panel 101 and, based on the actual output of the photovoltaic panel 101, determines whether the photovoltaic panel 101 is connected to the microinverter 102 for operation. In this way, even if the specifications of the photovoltaic panel are unknown or whether the photovoltaic panel 101 is located during the day or at night, the connection between the microinverter 102 and the photovoltaic panel 101 can still be accurately controlled, thereby effectively improving the reliability of the photovoltaic panel 101 connection.

[0102] In one embodiment, the load device R1 is a resistor.

[0103] Specifically, the specific type of load device R1 is not limited; any device capable of consuming electrical energy as a load may be used. In the embodiment of the present invention, load device R1 may be a resistor, specifically a single resistor, or a resistor assembly formed by connecting multiple resistors in series and / or in parallel. In another embodiment, load device R1 may be an energy-consuming device such as an indicator light.

[0104] Likewise, the specific type of the switch device Q1 is not limited. In one embodiment, the switch device Q1 is a power switch tube or a relay. The power switch tube can be a transistor, a field effect transistor, or an insulated gate bipolar transistor, etc., without specific limitation.

[0105] See also Figure 8 In one embodiment, the photovoltaic system further includes a switch device 801 , and the output end of the photovoltaic panel 101 is connected to the micro-inverter 102 through the switch device 801 .

[0106] Specifically, in this embodiment, a switch device 801 is further provided between the photovoltaic panel 101 and the microinverter 102. The switch device 801 is connected to a controller, which controls the switching device 801 to connect or disconnect the photovoltaic panel 101 from the microinverter 102. When the photovoltaic panel 101 is connected to the microinverter 102, the microinverter 102 can output electrical energy to the electrical device. When the photovoltaic panel 101 is not connected to the microinverter 102, the electrical device is not powered and stops operating.

[0107] It should be noted that the specific type of switch device 801 is not limited to a single type. The selection of the corresponding switch device 801 may also vary depending on the model of the photovoltaic panel 101. For example, in one embodiment, a DC converter may be used as the switch device 801. By controlling the start and stop of the DC converter, the connection between the photovoltaic panel 101 and the microinverter 102 is controlled. In other embodiments, a power switch or a relay may also be used as the switch device 801. The selection can be based on the actual scenario and is not limited here.

[0108] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0109] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for operating a photovoltaic system, characterized in that: The photovoltaic system includes a photovoltaic panel, a switch device, a load device and a micro-inverter, wherein the output end of the photovoltaic panel is connected to the first end of the load device and the micro-inverter, the second end of the load device is connected to the first end of the switch device, and the second end of the switch device is grounded; The operating method comprises: Upon receiving a power supply instruction, determining an output power parameter and an output electrical parameter ratio of the photovoltaic panel; The connection state between the photovoltaic panel and the micro-inverter is adjusted according to the ratio of the output power parameter to the output electrical parameter.

2. The operating method according to claim 1, characterized in that: Determining the ratio of the output power parameter and the output electrical parameter of the photovoltaic panel includes: When the switch device is disconnected, obtaining a first output voltage of the photovoltaic panel; When the switch device is closed, obtaining a second output voltage of the photovoltaic panel; An output power parameter and an output electrical parameter ratio are determined according to the first output voltage, the second output voltage, and the resistance value of the load device.

3. The operating method according to claim 2, characterized in that: The output power parameter includes a first power parameter and a second power parameter, and determining the ratio of the output power parameter to the output electrical parameter according to the first output voltage, the second output voltage, and the resistance value of the load device includes: determining the first power parameter according to the second output voltage and the resistance value of the load device; determining the second power parameter according to the first output voltage, the second output voltage, and the resistance value; An output electrical parameter ratio is determined according to the second output voltage and the first output voltage.

4. The operating method according to claim 3, characterized in that: The adjusting the connection state between the photovoltaic panel and the micro-inverter according to the ratio of the output power parameter to the output electrical parameter includes: When the ratio of the output power parameter to the output electrical parameter meets a preset parameter condition, and the first output voltage and the second output voltage meet a preset output condition, the photovoltaic panel is controlled to be connected to the micro-inverter for operation.

5. The operating method according to claim 4, characterized in that: The ratio of the output power parameter to the output electrical parameter satisfies a preset parameter condition, including: The first power parameter satisfies a first parameter condition, the second power parameter satisfies a second parameter condition, and the output electrical parameter ratio satisfies a third parameter condition.

6. The operating method according to claim 5, characterized in that: Include at least one of the following: Item 1: The first power parameter satisfies a first parameter condition, including: the first power parameter is greater than or equal to a first preset power threshold; Item 2: The second power parameter satisfies a second parameter condition, including: the second power parameter is less than or equal to a second preset power threshold; Item 3: The output electrical parameter ratio satisfies a third parameter condition, including: the output electrical parameter ratio is greater than or equal to a preset ratio threshold.

7. The operating method according to any one of claims 1 to 6, characterized in that: Before adjusting the access state of the photovoltaic panel and the micro-inverter according to the output power parameter and the output electrical parameter ratio, the method further includes: Obtaining the minimum system power consumption and the minimum load power consumption of the photovoltaic system, as well as the open circuit voltage and the operating voltage of the photovoltaic panel; Determining a first preset power threshold according to the system minimum power consumption and the load minimum power consumption; determining the second preset power threshold according to the open circuit voltage; A preset ratio threshold is determined according to the open circuit voltage and the operating voltage.

8. The operating method according to any one of claims 4 to 6, characterized in that: The first output voltage and the second output voltage satisfy a preset output condition, including: The first output voltage and the second output voltage are both within a preset input voltage range.

9. The operating method according to any one of claims 4 to 6, characterized in that: Before obtaining the first output voltage of the photovoltaic panel when the switch device is disconnected, the method further includes: obtaining the output terminal voltage of the photovoltaic panel; and verifying the working state of the switch device when the output terminal voltage meets a preset working condition; And / or, controlling the photovoltaic panel to connect to the micro-inverter for operation includes: controlling switch devices respectively connected to the photovoltaic panel and the micro-inverter to turn on; wherein the micro-inverter is used to connect to electrical equipment.

10. A photovoltaic system, characterized in that: include: load devices; Microinverter, used to connect power-consuming equipment; a photovoltaic panel, wherein an output end of the photovoltaic panel is connected to the first end of the load device and the micro-inverter; A voltage collector is provided at the output end of the photovoltaic panel; a switching device, wherein a first terminal of the switching device is connected to a second terminal of the load device, and a second terminal of the switching device is grounded; A controller is connected to the voltage collector and the third end of the switching device, and is used to implement the steps of the operating method according to any one of claims 1 to 9.

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