Inverter circuit, photovoltaic system and electric equipment

Abstract

The utility model relates to an inverter circuit, a photovoltaic system and electric equipment, the inverter circuit comprises a conversion circuit and an inverter, the conversion circuit comprises a first branch and a second branch, the first end of the first branch and the first end of the second branch are connected to a photovoltaic module, the first branch is provided with a DC / DC converter, and the second branch is provided with a DC / DC converter. The second end of the first branch circuit is also used for being connected to a storage battery; the first end of the first branch circuit and the second end of the second branch circuit are connected with the inverter, the inverter is further used for being electrically connected with the storage battery, the first MPPT controller is electrically connected with the inverter, and if the first branch circuit is switched on, the second end of the first branch circuit and the second end of the second branch circuit are connected with the inverter. The photovoltaic module supplies power to the inverter and / or the storage battery through the first branch; and if the first branch circuit is disconnected, the second branch circuit is connected, and the photovoltaic module supplies power to the inverter through the second branch circuit. The photovoltaic power generation system has the effects of adapting to different working environments and utilizing photovoltaic energy at the maximum efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic equipment, and in particular to an inverter circuit, a photovoltaic system and electrical equipment. Background Art

[0002] At present, with the growth of electricity demand, problems such as power shortage and high electricity prices are becoming more and more serious in some areas. For families with independent balconies, photovoltaic systems such as balcony photovoltaic products can reduce electricity costs and can also serve as emergency backup power to improve the reliability of home power supply.

[0003] In the related technology, the photovoltaic system usually has multiple photovoltaic panels connected in series or in series-parallel and then connected to the MPPT controller on the photovoltaic side to generate a DC bus, which is then inverted through an inverter or charged through a DC / DC module on the battery side. If you want to enable the energy storage battery to directly supply power to the grid without passing through the DC / DC module, you can set the DC / DC module on the photovoltaic side and add a branch so that the photovoltaic panel can power the inverter without the DC / DC module. However, the MPPT is only set on the photovoltaic side. This method cannot effectively control the output power of the photovoltaic panel and cannot meet the different power supply requirements under various working conditions. Utility Model Content

[0004] The present application is proposed to solve the above-mentioned problem. According to one aspect of the present application, an inverter circuit is provided, comprising: a conversion circuit, the conversion circuit comprising a first branch and a second branch, the first ends of the first branch and the second branch being connected to a photovoltaic component, a DC / DC converter being arranged on the first branch, and the second end of the first branch being also used to be connected to a battery; an inverter, the second ends of the first branch and the second branch being connected to the inverter, and the inverter being also used to be electrically connected to the battery, and a first MPPT controller, the first MPPT controller being electrically connected to the inverter to control the power outputted from the photovoltaic component to the inverter; if the first branch is turned on and the second branch is turned off, the photovoltaic component supplies power to the inverter and / or the battery through the first branch; if the first branch is turned off and the second branch is turned on, the photovoltaic component supplies power to the inverter through the second branch.

[0005] Exemplarily, the conversion circuit is connected to a first controller, which is electrically connected to the battery, and is used to control the conversion circuit to switch between a first state and a second state; wherein, when the conversion circuit is in the first state, the first branch is turned on and the second branch is turned off; when the conversion circuit is in the second state, the first branch is turned off and the second branch is turned on.

[0006] Exemplarily, the first controller is used to control the conversion circuit to switch between the first state and the second state according to the battery power of the battery and the power generation power of the photovoltaic assembly.

[0007] Exemplarily, when the generated power is between a first threshold and a second threshold and the battery power is greater than the first power threshold, the first controller is configured to control the first branch of the conversion circuit to be turned on and the second branch to be turned off; the photovoltaic assembly is configured to supply power to the inverter through the first branch, and the battery is configured to supply power to the inverter.

[0008] Exemplarily, when the generated power is not greater than a second threshold and the battery power is greater than a first power threshold, the first controller controls the first branch of the conversion circuit to be turned on and the second branch to be turned off; the photovoltaic component stops supplying power to the inverter, and the battery is configured to supply power to the inverter.

[0009] Exemplarily, when the generated power is greater than a first threshold and the battery power is less than a second power threshold, the first controller controls the first branch of the conversion circuit to be turned on and the second branch to be turned off; the photovoltaic assembly is configured to power the inverter through the first branch and charge the battery through the first branch.

[0010] Exemplarily, when the generated power is greater than a first threshold and the battery power is equal to the second power threshold, the first controller is configured to control the first branch of the conversion circuit to be disconnected and the second branch to be turned on; the photovoltaic assembly is configured to power the inverter through the second branch.

[0011] Exemplarily, the first MPPT controller is disposed on the inverter and electrically connected to the inverter.

[0012] Exemplarily, a control switch is provided on the second branch, and the first controller is configured to control the control switch to be closed so that the second branch is turned on.

[0013] Exemplarily, the first branch is also connected to a second MPPT controller. When the conversion circuit enters the first state, the first MPPT controller is turned off and the second MPPT controller is turned on to control the output power of the photovoltaic component; when the conversion circuit enters the second state, the first MPPT controller is turned on and the second MPPT controller is turned off.

[0014] Exemplarily, there are multiple conversion circuits, the first ends of the multiple conversion circuits are respectively used to connect to one photovoltaic component, the second ends of at least two of the conversion circuits are connected to the same inverter, and at least two of the conversion circuits are also used to connect to the same battery.

[0015] According to another aspect of the present application, a photovoltaic system is provided, the system comprising a photovoltaic component, a battery and the above inverter circuit.

[0016] According to another aspect of the present application, an electrical device is provided, wherein the electrical device includes the above-mentioned photovoltaic system.

[0017] The inverter circuit and photovoltaic system in the present application use a conversion circuit to realize the connection between the photovoltaic module, the battery and the inverter. The battery can directly power the inverter without passing through the DC / DC converter. When the second branch is turned on, the photovoltaic module can directly power the inverter without passing through the DC / DC converter to reduce power supply losses. When the first branch is turned on, the photovoltaic module can power both the inverter and the battery. The power of the photovoltaic panel can be controlled by the MPPT controller in different states to adapt to different working environments and achieve the effect of utilizing photovoltaic energy with maximum efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0019] Figure 1 The structure block diagram of the photovoltaic system in the related art is shown.

[0020] Figure 2 A schematic block diagram of a photovoltaic system in an embodiment of the present application is shown.

[0021] Figure 3 A circuit diagram of a photovoltaic system in an embodiment of the present application is shown.

[0022] Figure 4 A structural block diagram of a photovoltaic system in an embodiment of the present application is shown.

[0023] Figure 5 A state table of the photovoltaic system under different working conditions in an embodiment of the present application is shown.

[0024] Figure 6(a)-Figure 6(d) A block diagram showing the working status of the photovoltaic system under different working conditions in an embodiment of the present application.

[0025] Figure 7 A logic diagram of voltage conversion in a photovoltaic system in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0027] like Figure 1 The figure shows a photovoltaic system in the related art. In the related art, a photovoltaic system and multiple photovoltaic panels are connected in series or in series-parallel and then connected to an MPPT controller to generate a DC bus, and at the same time, they are inverted through an inverter or charged through a DC / DC module on the battery side. The photovoltaic panel needs to be connected to the MPPT controller on the photovoltaic side and then powered by an inverter. It is also difficult for the energy storage battery to directly power the grid without a DC / DC module, and photovoltaic energy cannot be efficiently utilized. When it is in the night state, it is difficult for the photovoltaic panel to be powered and it needs to be powered by a battery. However, the battery power supply needs to be boosted by a DC / DC module first, and then converted by an inverter, which will cause energy loss.

[0028] An embodiment of the present application provides an inverter circuit and a photovoltaic system. The inverter circuit includes a conversion circuit and an inverter. The photovoltaic system includes: a photovoltaic module, a battery and the inverter circuit.

[0029] like Figure 2 As shown, it is a structural block diagram of the photovoltaic system in the embodiment of the present application. Among them, the conversion circuit includes a first branch and a second branch, the first end of the first branch and the second branch are connected to the photovoltaic module, the second end of the first branch and the second branch are connected to the inverter, a DC / DC converter is arranged on the first branch, the second end of the first branch is also connected to the battery, and the battery is also electrically connected to the inverter. The inverter is electrically connected to a first MPPT (Maximum Power Point Tracking) controller, and the first MPPT controller is used to control the power output from the photovoltaic module to the inverter.

[0030] If the first branch is on and the second branch is off, the photovoltaic assembly supplies power to the inverter and / or the battery through the first branch. If the first branch is off and the second branch is on, the photovoltaic assembly supplies power to the inverter through the second branch. In addition, when the first branch is on and the second branch is off, the battery can also supply power to the inverter.

[0031] The inverter circuit and photovoltaic system in the embodiments of the present application use a conversion circuit to realize the connection between the photovoltaic module, the battery and the inverter. The battery can directly power the inverter without passing through the DC / DC converter. When the second branch is turned on, the photovoltaic module can directly power the inverter without passing through the DC / DC converter to reduce power supply losses. When the first branch is turned on, the photovoltaic module can power both the inverter and the battery. The power of the photovoltaic panel can be controlled by the MPPT controller in different states to adapt to different working environments and achieve the effect of maximizing the efficiency of photovoltaic energy utilization.

[0032] Exemplarily, the inverter in the embodiment of the present application may be a micro-inverter. The first MPPT controller may be arranged on the inverter and electrically connected to the inverter, or the first MPPT controller may be independently arranged before the conversion circuit and the inverter and electrically connected to the inverter, or the first MPPT controller may be integrated in the control module of the inverter, and both are used to control the power outputted by the photovoltaic component to the inverter. In the photovoltaic system, there are multiple conversion circuits, the first ends of the multiple conversion circuits are respectively used to connect a photovoltaic component, the second ends of at least two conversion circuits are connected to the same micro-inverter, and at least two conversion circuits are also used to connect to the same battery. Among them, the number of photovoltaic components is at least one and at most four, and each photovoltaic component is configured with a conversion circuit. When a photovoltaic component has problems such as local overheating due to the spot effect, other photovoltaic components are not easily affected, which can avoid the overall short board effect of the photovoltaic system and reduce energy loss.

[0033] Exemplarily, the conversion circuit is connected to a first controller, the first controller is electrically connected to the battery, and the first controller is used to control the conversion circuit to switch between a first state and a second state. When the conversion circuit is in the first state, the first branch is turned on and the second branch is turned off; when the conversion circuit is in the second state, the first branch is turned off and the second branch is turned on. A control switch is provided on the second branch, and the first controller is configured to control the control switch to close so that the second branch is turned on. The control switch can be a single-pole double-throw switch. When the control switch is configured to different positions, it can correspond to the state where the first branch is turned on and the second branch is turned off (the first state of the conversion circuit), and the state where the first branch is turned off and the second branch is turned on (the second state of the conversion circuit).

[0034] like Figure 3As shown in FIG. 1 , it is a circuit diagram of a photovoltaic system in an embodiment of the present application. It should be noted that: Figure 3 A partial structure of a photovoltaic system is shown to illustrate the structure and state changes of a conversion circuit.

[0035] exist Figure 3 In the figure, two photovoltaic modules are provided, and their input and output are represented by PV1+, PV1-, PV2+ and PV2- respectively. The conversion circuit includes a first branch and a second branch. The first branch includes a DC / DC converter. The DC / DC converters of the two photovoltaic modules are represented by D11 and D12 respectively in the figure. A control switch (K1 and K2 respectively) is provided on the second branch. When the second branch is turned on, the first branch will be in a disconnected state, and the photovoltaic module cannot supply power to the micro-inverter through the first branch, nor can it charge the battery B1. When the second branch is disconnected, the first branch can be turned on to supply power to the micro-inverter through the first branch. In addition, the first branch is also connected to the battery B1, and the photovoltaic module can charge the battery B1 through the DC / DC converter. A switch is also provided on the battery B1. When the switch is turned on, the battery can be charged or discharged, and when the switch is disconnected, the battery cannot be charged or discharged.

[0036] like Figure 4 As shown, it is a block diagram of the photovoltaic system in the embodiment of the present application. Exemplarily, the first controller connected to the conversion circuit can be an MCU, and the battery is connected to a battery management system (BMS). The battery management system can collect battery information including voltage and power of the battery, and send it to the first controller, and the first controller obtains the battery power of the battery through the battery management system. In addition, the first controller can also obtain the current PV power of the photovoltaic module (the power generation power of the photovoltaic module), and the first controller is also used to control the conversion circuit to switch between the first state and the second state according to the battery power of the battery and the power generation power of the photovoltaic module, so as to adapt to different working conditions. Among them, the first controller can be connected to the corresponding current sampler and voltage sampler, so as to obtain the voltage and current of the photovoltaic module through the sampler, and obtain the power generation power of the photovoltaic module through the voltage and current. For the photovoltaic module, its power generation power is mainly related to the light intensity, and the size of the light intensity at the current moment can be obtained by the size of the power generation power. In addition, the first controller can also control the opening and closing of the switch on the battery, so as to control whether the battery is charged (discharged) or not.

[0037] Exemplarily, the first branch is also connected to a second MPPT controller, and when the conversion circuit enters the first state, the second MPPT controller is turned on to control the output power of the photovoltaic module. When the conversion circuit enters the second state, the second MPPT controller is turned off. The microinverter is connected to the first MPPT controller, and when the second MPPT controller is turned on, the first MPPT controller is turned off, and when the second MPPT controller is turned off, the first MPPT controller is turned on. When the second MPPT controller and the first MPPT controller are working, they can detect the power generation voltage of the photovoltaic module in real time and track the maximum voltage and current value (VI), so that the system outputs at maximum power and realizes the control of the output power of the photovoltaic module.

[0038] For example, in the embodiment of the present application, only one of the second MPPT controller and the first MPPT controller participates in the operation at the same time. When the conversion circuit is in the second state, the second branch is turned on, the second MPPT controller no longer participates in the operation, and the output power can be controlled by the first MPPT controller in the micro-inverter.

[0039] like Figure 5 As shown in the figure, it is a working state table of the photovoltaic system under different working conditions. The table divides the photovoltaic system into four different states.

[0040] After obtaining the battery power and the power generation power of the photovoltaic module, the first controller will compare them with the set threshold. For example, for the power generation power, a first threshold and a second threshold are set, where the first threshold is greater than the second threshold. For the photovoltaic module, the power generation power is mainly related to the light intensity. When the light is sufficient, the power of the photovoltaic module is greater than the first threshold X1.

[0041] When the power generation is between the first threshold and the second threshold, that is, the power of the photovoltaic module is 0-X1, indicating insufficient light. When the power generation is less than or equal to the second threshold, it means that the photovoltaic module is at night or the light intensity is extremely weak, and it is difficult to supply power, wherein the second threshold can be 0. For the battery power, a first power threshold and a second power threshold are set. The first power threshold can be represented by X2%. When the battery power is greater than the first power threshold, it means that the battery power is not empty. When the battery power is less than or equal to the first power threshold, it means that the battery power is empty and can only be charged instead of discharged. In order to ensure the service life of the battery, the first power threshold will not be set to 0%. Exemplarily, the first power threshold can be set to a value between 2%-10%, or it can be adjusted according to usage habits or actual conditions, and a suitable first power threshold is adopted. When the battery power is less than the second power threshold, it means that the battery is full, and the second power threshold can be 100%. When the battery power is equal to the second power threshold, it means that the battery is full and no further charging is required.

[0042] When the conversion circuit is in the first state, the DC / DC converter is in operation. When the conversion circuit is in the second state, the photovoltaic assembly is connected to the micro-inverter through the second branch, and the DC / DC converter is not in operation.

[0043] The ɑ in the table is the photovoltaic panel power allocation factor, which ranges from 0 to 1. The larger the value of a, the higher the proportion of power used to charge the battery in the output power of the photovoltaic module. η represents the overall efficiency of the microinverter for inversion. Its value ranges from 0 to 1. In actual use, the value of η is generally not 1 or 0. The battery power in the table refers to the power used to charge or discharge the battery. When the battery is fully charged, the battery power is 0. When the sunlight is insufficient and the battery power is low, the battery will be charged first, and the battery power is the power generation power of the photovoltaic module. The inverter power represents the power converted by the microinverter. When the photovoltaic module only charges the battery, the inverter power is 0. When the battery is full, the photovoltaic module only supplies power to the inverter. The inverter power is the product of the power generation power (PV power) of the photovoltaic module and η.

[0044] MPPT control refers to the state of the first MPPT controller connected to the micro-inverter. Only one of the second MPPT controller and the first MPPT controller is involved in the work at the same time. When the conversion circuit is in the second state, the second branch is turned on, and the second MPPT controller is no longer involved in the work. The output power can be controlled by the first MPPT controller in the micro-inverter. Similarly, when the second branch is disconnected, the first MPPT controller is turned on and enters the working state.

[0045] like Figure 6(a)-Figure 6(d) , which are the working states under different working conditions in the embodiments of this application. Figure 5 and Figure 6 , which illustrate the working status under different working conditions.

[0046] As shown in FIG6(a), it is a state where the light is insufficient and the battery is not discharged. The first controller confirms that the power generation is between the first threshold and the second threshold, and the battery power is greater than the first power threshold, and the first controller is configured to control the conversion circuit to enter the first state, the second branch is disconnected and the first branch is turned on.

[0047] The photovoltaic assembly is configured to supply power to the micro-inverter through the first branch, and the storage battery is configured to supply power to the micro-inverter. The photovoltaic assembly supplies power to the micro-inverter through the DC / DC converter, and the storage battery can supply power to the inverter through the DC bus.

[0048] In this state, the power of the photovoltaic module is between 0 and X1, and the battery power is greater than the first power threshold value X2%. The battery power of the storage battery is the maximum dischargeable current * battery voltage. The inverter power in the micro-inverter is PV power * η + battery power.

[0049] Exemplarily, the micro-inverter is connected with a plug-in terminal, which is convenient for the user to connect it to the power grid or power-consuming equipment.

[0050] As shown in Figure 6(b), the photovoltaic module is at night and the battery is not discharged. The first controller confirms that the power generation is not greater than the second threshold value, and the battery power is greater than the first power threshold value, and the first controller controls the conversion circuit to enter the first state, the first branch is turned on and the second branch is disconnected. Exemplarily, when the power generation is not greater than the second threshold value, it means that the photovoltaic module is at night or other conditions where the light intensity is extremely weak and the photovoltaic module is difficult to power.

[0051] The PV panels stop supplying power to the micro-inverter, and the battery is configured to supply power to the micro-inverter. The PV panels are difficult to supply power, and can only supply power to the micro-inverter through the battery. The battery can supply power without passing through a DC / DC converter, which can reduce energy loss.

[0052] In this state, the PV power is 0, the battery power is the maximum dischargeable current * battery voltage, and the inverter power of the microinverter is the battery power.

[0053] As shown in FIG6(c), the photovoltaic module is in a state where the illumination is sufficient and the battery is not fully charged. When the first controller confirms that the generated power is greater than the first threshold and the battery power is less than the second power threshold, the first controller controls the conversion circuit to enter the first state. The first branch is turned on and the second branch is turned off.

[0054] The photovoltaic assembly is configured to supply power to the micro-inverter through the first branch and to charge the battery through the first branch; wherein the battery power is less than the second power threshold, indicating that the battery power is not fully charged. That is, in this case, the photovoltaic assembly not only charges the battery through the DC / DC converter, but also supplies power to the micro-inverter.

[0055] In this state, the PV power is greater than X1, and the battery is not fully charged. The battery is in a charging state and the battery power is the minimum of PV power*a and the maximum chargeable current*battery voltage. The inverter power of the microinverter is PV power*η-battery power.

[0056] As shown in FIG6(d), it is a state where the sunlight is sufficient and the battery is fully charged. When the power generation is greater than the first threshold and the battery charge is equal to the second charge threshold, the first controller is configured to control the conversion circuit to enter the second state, with the second branch being turned on and the first branch being turned off. When the battery charge is equal to the second charge threshold, it means that the battery is fully charged.

[0057] The PV panels are configured to supply power to the microinverter through the second branch. Because there is sufficient sunlight, the battery does not discharge, and because the battery is already fully charged, there is no need to charge it.

[0058] In this state, the PV power is greater than X1, and the battery is fully charged, so the power used to charge the battery is 0. The inverter power of the microinverter is PV power*η. At this time, the first MPPT controller is in the on state, which is used to control the power of the photovoltaic module.

[0059] In addition, when the light is insufficient and the battery power is insufficient (this state is not shown in FIG. 6 ), the battery power is less than or equal to the first power threshold value X2%. The PV power of the photovoltaic module is between 0 and X1. At this time, the power of the photovoltaic module is mainly used to charge the battery, and the battery power is the PV power. Neither the battery nor the photovoltaic module supplies power to the micro-inverter, and the inverter power of the micro-inverter is 0.

[0060] Based on the above introduction, the photovoltaic system in the embodiment of the present application uses a conversion circuit to realize the connection between the photovoltaic module, the battery and the micro-inverter. The battery can directly power the micro-inverter without passing through the DC / DC converter. When the conversion circuit is in the second state, the photovoltaic module can directly power the micro-inverter without passing through the DC / DC converter to reduce the power supply loss. When the conversion circuit is in the first state, both the photovoltaic module and the battery can power the micro-inverter. This system can adapt to different working environments, has different power supply modes under different working conditions, and can achieve the effect of utilizing photovoltaic energy with maximum efficiency.

[0061] like Figure 7 As shown, it is a logic diagram of voltage conversion in the photovoltaic system in the embodiment of the present application. The figure illustrates the adaptive adjustment of voltage during the process of photovoltaic components charging the battery. For example, the DC / DC converter in the present application adopts Buck-Boost (step-up and step-down converter), and the process of voltage adjustment is:

[0062] After the conversion circuit is powered on for the first time, the first controller detects the open circuit voltage Vpv_ocv of the photovoltaic module and the open circuit voltage Vbatt_ocv of the battery.

[0063] According to the relationship between Vpv_ocv and Vbatt_ocv, it is determined whether the DC / DC enters the boost mode, buck mode or buck-boost mode, and the initial duty cycle D is calculated. The preset threshold of Vbatt_ocv is: 0.7Vpv_ocv-1.3Vpv_ocv.

[0064] If the open circuit voltage of the battery exceeds 1.3 times the open circuit voltage of the photovoltaic module, it means that the voltage provided by the photovoltaic module is insufficient and the voltage output by the photovoltaic module needs to be boosted. On the contrary, if the open circuit voltage of the battery is less than 0.7 times the open circuit voltage of the photovoltaic module, it means that the voltage provided by the photovoltaic module is too high and the voltage output by the photovoltaic module needs to be stepped down. This allows the value of Vbatt to be between 0.9Vpv-1.1Vpv (the voltage output by the photovoltaic module after adjustment).

[0065] Based on the second MPPT controller, the MPPT algorithm is used to adjust the duty cycle D so that the photovoltaic module can output maximum power.

[0066] During operation, the voltage of the battery may change in real time, and Vpv and Vbatt need to be detected in real time for updating. For example, if after adjustment, Vbatt is still not less than 1.2Vpv or not more than 0.8Vpv, it is necessary to adjust again. Ultimately, the voltage of the photovoltaic module charging the battery after the DC / DC change is maintained within a suitable range. It should be noted that the above-mentioned preset thresholds such as 0.9Vpv-1.1Vpv are all examples. They can be adjusted according to actual conditions.

[0067] An embodiment of the present application further provides an electrical device, which includes the above-mentioned photovoltaic system.

[0068] The electrical equipment in the embodiment of the present application samples the above-mentioned photovoltaic system for power supply, uses a conversion circuit to realize the connection between the photovoltaic module, the battery and the micro-inverter, and the battery can directly power the micro-inverter without passing through the DC / DC converter. When the conversion circuit is in the second state, the photovoltaic module can directly power the micro-inverter without passing through the DC / DC converter to reduce the power supply loss, and when the conversion circuit is in the first state, the photovoltaic module and the battery can both power the micro-inverter. It can adapt to different working environments, has different power supply modes under different working conditions, and can achieve the effect of utilizing photovoltaic energy with maximum efficiency.

[0069] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0070] The above is only a specific implementation method or description of a specific implementation method of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An inverter circuit, characterized in that: include: A conversion circuit, the conversion circuit comprising a first branch and a second branch, the first ends of the first branch and the second branch are connected to a photovoltaic assembly, a DC / DC converter is provided on the first branch, and the second end of the first branch is also used to be connected to a storage battery; An inverter, the second ends of the first branch and the second branch are connected to the inverter, and the inverter is also used to be electrically connected to the battery; a first MPPT controller, the first MPPT controller being electrically connected to the inverter and used for controlling the power outputted from the photovoltaic assembly to the inverter; If the first branch is turned on and the second branch is turned off, the photovoltaic assembly supplies power to the inverter and / or the battery through the first branch; If the first branch is disconnected and the second branch is turned on, the photovoltaic assembly supplies power to the inverter through the second branch.

2. The inverter circuit according to claim 1, characterized in that: The conversion circuit is connected to a first controller, the first controller is electrically connected to the battery, and the first controller is used to control the conversion circuit to switch between a first state and a second state; When the conversion circuit is in the first state, the first branch is turned on and the second branch is turned off; when the conversion circuit is in the second state, the first branch is turned off and the second branch is turned on.

3. The inverter circuit according to claim 2, characterized in that: The first controller is used to control the conversion circuit to switch between the first state and the second state according to the battery power of the battery and the power generation power of the photovoltaic component.

4. The inverter circuit according to claim 3, characterized in that: When the generated power is between a first threshold and a second threshold, and the battery power is greater than the first power threshold, the first controller is configured to control the first branch of the conversion circuit to be turned on and the second branch to be turned off; The photovoltaic assembly is configured to supply power to the inverter through the first branch, and the battery is configured to supply power to the inverter.

5. The inverter circuit according to claim 3, characterized in that: When the generated power is not greater than the second threshold value and the battery power is greater than the first power threshold value, the first controller controls the first branch of the conversion circuit to be turned on and the second branch to be turned off; The photovoltaic assembly stops supplying power to the inverter, and the battery is configured to supply power to the inverter.

6. The inverter circuit according to claim 3, characterized in that: When the generated power is greater than a first threshold and the battery power is less than a second power threshold, the first controller controls the first branch of the conversion circuit to be turned on and the second branch to be turned off; The photovoltaic assembly is configured to supply power to the inverter through the first branch and to charge the battery through the first branch.

7. The inverter circuit according to claim 6, characterized in that: When the generated power is greater than a first threshold and the battery power is equal to the second power threshold, the first controller is configured to control the first branch of the conversion circuit to be disconnected and the second branch to be connected; The photovoltaic assembly is configured to supply power to the inverter through the second branch.

8. The inverter circuit according to any one of claims 1 to 7, characterized in that: The first MPPT controller is disposed on the inverter and is electrically connected to the inverter.

9. The inverter circuit according to any one of claims 2 to 7, characterized in that: The second branch is provided with a control switch, and the first controller is configured to control the control switch to be closed so that the second branch is turned on.

10. The inverter circuit according to any one of claims 2 to 7, characterized in that: The first branch is also connected to a second MPPT controller, and when the conversion circuit enters the first state, the first MPPT controller is turned off and the second MPPT controller is turned on to control the output power of the photovoltaic assembly; When the conversion circuit enters the second state, the first MPPT controller is turned on and the second MPPT controller is turned off.

11. The inverter circuit according to any one of claims 1 to 7, characterized in that: There are multiple conversion circuits, and the first ends of the multiple conversion circuits are respectively used to connect to one photovoltaic component, and the second ends of at least two conversion circuits are connected to the same inverter, and at least two conversion circuits are also used to connect to the same battery.

12. A photovoltaic system, characterized in that: The system comprises a photovoltaic component, a battery and an inverter circuit as claimed in any one of claims 1 to 11.

13. An electrical equipment, characterized in that: The electrical equipment comprises the photovoltaic system according to claim 12.

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