Boost circuit structure, inverter device and photovoltaic power generation system

Abstract

This invention relates to the field of electronic circuit technology, specifically providing a boost circuit structure, an inverter device, and a photovoltaic power generation system. The structure includes a switching circuit, a boost main circuit, a boost branch circuit, a first functional circuit, and a second functional circuit. This application uses the switching circuit, the boost main circuit, and the boost branch circuit to form the boost circuit structural framework. The first functional circuit connects the flying capacitor to the input terminals to charge the flying capacitor during power-on at the input side of the boost circuit, protecting the second controllable switch from overvoltage. The second functional circuit is connected in parallel with the second diode to charge the flying capacitor during power-on at the output side of the boost circuit, protecting the second diode from overvoltage.

Description

Technical Field

[0001] This invention belongs to the field of electronic circuit technology, and particularly relates to a boost circuit structure, an inverter device, and a photovoltaic power generation system. Background Technology

[0002] In a flying capacitor boost circuit, when the topology is initially powered on, the flying capacitor has no voltage, which can easily lead to overvoltage damage to other components. For example... Figure 1 As shown, a traditional boost circuit consists of inductor L1, switching devices T1 and T2, diodes D1 and D2, and a flying capacitor C1. When the input side Cin is powered on, if the flying capacitor C1 has no voltage, it will cause the voltage of switching device T2 to be too high. Furthermore, when boost circuits are used in parallel, if other circuits are powered on first, or if a subsequent circuit powers the output side Cout first, the lack of voltage across the flying capacitor C1 can easily lead to overvoltage in diode D2. In photovoltaic applications, the overvoltage situation is particularly severe when the PV (Photovoltaic) side switch is closed or the bus is powered on.

[0003] Existing solutions use active devices to disconnect the flying capacitor loop, clamp the device voltage to the corresponding capacitor voltage, and limit the power-on / off timing. However, disconnecting the corresponding loop with active devices and closing it again during normal topology operation increases overall operating losses, as well as control resources and costs. Clamping the corresponding device to the corresponding capacitor voltage requires using capacitors to divide the bus voltage or using the overall bus capacitance for voltage division, increasing system cost and coupling. Using external circuits or operation sequence control circuits to control the power-on / off timing, pre-charging the flying capacitor before the main topology powers on, increases control logic and system complexity. Summary of the Invention

[0004] This invention provides a boost circuit structure that solves the problems of high cost and operating cost, as well as high control logic and system complexity in existing flying capacitor boost circuit systems.

[0005] This invention is implemented as follows: a boost circuit structure, comprising:

[0006] The switching circuit includes a first controllable switch and a second controllable switch connected in series. One end of the first controllable switch is connected to one input end of the boost circuit through an inductor. The other end of the first controllable switch is connected to one end of the second controllable switch. The other end of the second controllable switch is connected to the two input ends and the two output ends of the boost circuit.

[0007] The boost main circuit includes a first diode and a second diode. The anode of the first diode is connected to one end of the first controllable switch, the cathode of the first diode is connected to the anode of the second diode, and the cathode of the second diode is connected to one end of the output of the boost circuit.

[0008] The boost circuit includes a flying capacitor, one end of which is connected to the other end of the first controllable switch, and the other end of which is connected to the cathode of the first diode.

[0009] The first functional circuit is connected to the flying capacitor and the two input terminals, and is used to charge the flying capacitor when the input side of the boost circuit is powered on.

[0010] The second functional circuit, connected in parallel with the second diode, is used to charge the flying capacitor when the output side of the boost circuit is powered on.

[0011] Furthermore, the first functional circuit includes a first Zener diode;

[0012] The cathode of the first Zener diode is connected to one end of the flying capacitor, and the anode of the first Zener diode is connected to both input terminals.

[0013] Furthermore, the second functional circuit includes a second Zener diode;

[0014] The anode of the second Zener diode is connected to the anode of the second diode, and the cathode of the second Zener diode is connected to the cathode of the second diode.

[0015] Furthermore, the first functional circuit also includes a third diode;

[0016] The cathode of the first Zener diode is connected to the cathode of the third diode, and is connected to one end of the flying capacitor through the third diode.

[0017] Furthermore, the second functional circuit also includes a fourth diode;

[0018] The anode of the second Zener diode is connected to the anode of the fourth diode, and the anode of the second diode is connected through the fourth diode.

[0019] Furthermore, the boost circuit also includes a first resistor, and the first functional circuit also includes a second resistor;

[0020] The first resistor is connected in parallel with the flying capacitor;

[0021] The second resistor is connected in parallel with the first Zener diode.

[0022] Furthermore, the second functional circuit also includes a third resistor, which is connected in parallel with the second diode.

[0023] Furthermore, the boost circuit also includes a fourth resistor and a switch. One end of the switch is connected to one end of the flying capacitor through the fourth resistor, and the other end of the switch is connected to the input terminals.

[0024] Secondly, this application also provides an inverter device, including the boost circuit structure described above.

[0025] Thirdly, this application also provides a photovoltaic power generation system, including the inverter device as described above.

[0026] The beneficial effects of this invention are that the present application forms a boost circuit structure framework by means of a switching circuit, a boost main circuit and a boost branch circuit, and then connects the flying capacitor and the two input terminals through the first functional circuit to charge the flying capacitor during the power-on process of the boost circuit input side, thereby protecting the second controllable switch from overvoltage; while the second functional circuit is connected in parallel with the second diode to charge the flying capacitor during the power-on process of the boost circuit output side, thereby protecting the second diode from overvoltage. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the circuit structure of one embodiment of a prior art boost circuit structure;

[0028] Figure 2 This is a schematic diagram of a circuit module of one embodiment of the boost circuit structure provided in this application;

[0029] Figure 3 This is a schematic diagram of a circuit module of another embodiment of the boost circuit structure provided in this application;

[0030] Figure 4 This is a schematic diagram of the circuit structure of one embodiment of the boost circuit structure provided in this application;

[0031] Figure 5 This is a schematic diagram of a further improvement of the first functional circuit of one embodiment of the boost circuit structure provided in this application;

[0032] Figure 6 This is a schematic diagram of a further improved second functional circuit of one embodiment of the boost circuit structure provided in this application;

[0033] Figure 7 yes Figure 6 A schematic diagram of another embodiment of the circuit structure shown;

[0034] Figure 8 This is a schematic diagram of the circuit structure of another embodiment of the boost circuit structure provided in this application;

[0035] Figure 9 yes Figure 8 A schematic diagram of another embodiment of the circuit structure shown;

[0036] Figure 10 This is a schematic diagram of the current flow in one embodiment of the boost circuit structure provided in this application;

[0037] Figure 11 yes Figure 8 A schematic diagram of the current flow in another embodiment of the circuit structure shown;

[0038] Figure 12 This is a schematic diagram of the current flow of another embodiment of the boost circuit structure provided in this application;

[0039] Figure 13 yes Figure 12 A schematic diagram of the current flow in another embodiment of the circuit structure shown;

[0040] Figure 14 This is a schematic diagram of the current flow in another embodiment of the boost circuit structure provided in this application;

[0041] Figure 15 yes Figure 14 A schematic diagram of the current flow in another embodiment of the circuit structure shown. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] In this embodiment of the invention, a boost circuit structure framework is formed by a switching circuit, a boost main circuit, and a boost branch circuit. Then, a first functional circuit is connected to the flying capacitor and the two input terminals to charge the flying capacitor during the power-on process on the input side of the boost circuit, thus protecting the second controllable switch from overvoltage. The second functional circuit is connected in parallel with the second diode to charge the flying capacitor during the power-on process on the output side of the boost circuit, thus protecting the second diode from overvoltage.

[0044] Example 1

[0045] like Figures 2 to 15 As shown, this embodiment provides a boost circuit structure, including:

[0046] The switching circuit includes a first controllable switch T1 and a second controllable switch T2 connected in series. One end of the first controllable switch T1 is connected to one input end of the boost circuit through an inductor L1. The other end of the first controllable switch T1 is connected to one end of the second controllable switch T2. The other end of the second controllable switch T2 is connected to the two input ends and the two output ends of the boost circuit.

[0047] The boost main circuit includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to one end of the first controllable switch T1, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to one end of the output of the boost circuit.

[0048] The boost circuit includes a flying capacitor C1, one end of which is connected to the other end of the first controllable switch T1, and the other end of which is connected to the cathode of the first diode D1.

[0049] The first functional circuit 100 is connected to the flying capacitor C1 and the two input terminals, and is used to charge the flying capacitor C1 when the input side of the boost circuit is powered on.

[0050] The second functional circuit 200 is connected in parallel with the second diode D2 and is used to charge the flying capacitor C1 when the output side of the boost circuit is powered on.

[0051] In implementation, the first controllable switch T1 and the second controllable switch T2 can be power switching transistors. For example, the first controllable switch T1 is a first MOSFET, and the second controllable switch T2 is a second MOSFET. The drain of the first MOSFET is connected to one end of the inductor L1, the source of the first MOSFET is connected to the drain of the second MOSFET, the source of the second MOSFET is connected to the input terminals and the output terminals of the boost circuit, and the other end of the inductor L1 is connected to one input terminal of the boost circuit.

[0052] Optionally, the input terminal one and input terminal two of the boost circuit are the two ends of the input side Cin of the boost circuit. For example, the input side Cin of the boost circuit includes a positive input and a negative input, wherein when the input terminal one is a positive input, the input terminal two is a negative input; and when the input terminal one is a negative input, the input terminal two is a positive input.

[0053] Optionally, the anode of the first diode D1 is connected to the drain of the first MOSFET, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to one output terminal of the boost circuit.

[0054] Optionally, the output terminals one and two of the boost circuit are the two ends of the output side Cout of the boost circuit. For example, the output side Cout of the boost circuit includes a positive output and a negative output, wherein when the output terminal one is a positive output, the output terminal two is a negative output; and when the output terminal one is a negative output, the output terminal two is a positive output.

[0055] Optionally, one end of the flying capacitor C1 is connected to the source of the first MOSFET, that is, one end of the flying capacitor C1 is connected to the line between the first MOSFET and the second MOSFET. The other end of the flying capacitor C1 is connected to the cathode of the first diode D1, that is, the other end of the flying capacitor C1 is connected to the line between the first diode D1 and the second diode D2.

[0056] Optionally, the first functional circuit 100 connects one end of the flying capacitor C1 and the two input terminals. In some possible embodiments, the first functional circuit 100 can be a passive or active device to charge the flying capacitor C1 during the power-on process of the input side Cin, thereby protecting the second controllable switch T2 from overvoltage.

[0057] Optionally, the second functional circuit 200 is connected in parallel with the second diode D2. In some possible embodiments, the second functional circuit 200 can be a passive or active device used to charge the flying capacitor C1 during the power-on process of the output side Cout, thereby protecting the second diode D2 from overvoltage.

[0058] In some embodiments, the boost circuit structure provided in this application can also be adapted to meet actual needs and the usage environment, for example... Figure 3 The circuit structure shown is not limited here.

[0059] In this embodiment, a boost circuit structure framework is formed by a switching circuit, a boost main circuit, and a boost branch circuit. Then, a first functional circuit 100 is connected to the flying capacitor C1 and the two input terminals to charge the flying capacitor C1 during the power-on process on the input side of the boost circuit, thus protecting the second controllable switch T2 from overvoltage. The second functional circuit 200 is connected in parallel with the second diode D2 to charge the flying capacitor C1 during the power-on process on the output side of the boost circuit, thus protecting the second diode D2 from overvoltage.

[0060] Example 2

[0061] In some alternative embodiments, such as Figure 4 As shown, the first functional circuit 100 includes a first Zener diode ZD1;

[0062] The cathode of the first Zener diode ZD1 is connected to one end of the flying capacitor C1, and the anode of the first Zener diode ZD1 is connected to the two input terminals.

[0063] Furthermore, the second functional circuit 200 includes a second Zener diode ZD2;

[0064] The anode of the second Zener diode ZD2 is connected to the anode of the second diode D2, and the cathode of the second Zener diode ZD2 is connected to the cathode of the second diode D2.

[0065] In implementation, when the input side Cin is powered on, the voltage of the flying capacitor C1 is 0. The input side Cin forms a circuit through the inductor L1, the first diode D1, the flying capacitor C1, and the first Zener diode ZD1 to charge the flying capacitor C1. During the breakdown and discharge process of the first Zener diode ZD1, it can clamp the voltage of the second controllable switch T2 to the preset voltage to avoid damage to the second controllable switch T2 due to overvoltage. The power of the first Zener diode ZD1 is related to the capacitance value of the flying capacitor C1.

[0066] Optionally, when the output side Cout is powered on, the voltage of the flying capacitor C1 is 0. The output side Cout forms a circuit through the second Zener diode ZD2, the flying capacitor C1, the first controllable switch T1, the anti-parallel diode, and the inductor L1 to charge the flying capacitor C1. During the breakdown and discharge process of the second Zener diode ZD2, the voltage of the second diode D2 can be clamped to a preset voltage to avoid damage to the second diode D2 due to overvoltage. The power of the second Zener diode ZD2 is related to the capacitance value of the flying capacitor C1.

[0067] Example 3

[0068] In some alternative embodiments, such as Figure 5 As shown, the first functional circuit 100 also includes a third diode D3;

[0069] The cathode of the first Zener diode ZD1 is connected to the cathode of the third diode D3, and is connected to one end of the flying capacitor C1 through the third diode D3.

[0070] Furthermore, such as Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the second functional circuit 200 also includes a fourth diode D4;

[0071] The anode of the second Zener diode ZD2 is connected to the anode of the fourth diode D4, and is connected to the anode of the second diode D2 through the fourth diode D4.

[0072] In practice, the third diode D3 and the fourth diode D4 can be clamping diodes, and the first Zener diode ZD1 and the second Zener diode ZD2 can be transient voltage suppression TVS diodes, Zener diodes or other similar discharge devices, which are not limited here.

[0073] During implementation, when the input side Cin is powered on, the voltage across the flying capacitor C1 is 0, such as... Figure 10As shown, on the input side, Cin forms a circuit through inductor L1, first diode D1, flying capacitor C1, third diode D3, and first Zener diode ZD1 to charge the flying capacitor C1. During the breakdown and discharge process of the first Zener diode ZD1, it can clamp the voltage of the second controllable switch T2 to a preset voltage to avoid damage to the second controllable switch T2 due to overvoltage. The power of the first Zener diode ZD1 is related to the capacitance value of the flying capacitor C1.

[0074] Optionally, when the output side Cout is powered on, the voltage across the flying capacitor C1 is 0, such as... Figure 11 As shown, on the output side, Cout forms a circuit through the second Zener diode ZD2, the fourth diode D4, the flying capacitor C1, the first controllable switch T1, the anti-parallel diode, and the inductor L1 to charge the flying capacitor C1. During the breakdown and discharge process of the second Zener diode ZD2, the voltage of the second diode D2 can be clamped to a preset voltage to avoid damage to the second diode D2 due to overvoltage. The power of the second Zener diode ZD2 is related to the capacitance value of the flying capacitor C1.

[0075] Using passive devices such as discharge clamps can reduce the use of capacitors, simplify the topology operation, and reduce system costs.

[0076] Example 4

[0077] In some alternative embodiments, such as Figure 12 and Figure 13 As shown, the boost circuit also includes a first resistor R1, and the first functional circuit 100 also includes a second resistor R2.

[0078] The first resistor R1 is connected in parallel with the flying capacitor C1;

[0079] The second resistor R2 is connected in parallel with the first Zener diode ZD1.

[0080] Furthermore, the second functional circuit 200 also includes a third resistor R3, which is connected in parallel with the second diode ZD2.

[0081] In implementation, the secondary pre-charge process of the flying capacitor C1 can be completed through impedance voltage division, which reduces system complexity. For example... Figure 12 As shown, during the power-on process on the input side Cin, the first resistor R1 and the second resistor R2 divide the voltage, and the voltage of the flying capacitor C1 is charged to the preset voltage through the circuit composed of inductor L1, first diode D1, first resistor R1, third diode D3, and second resistor R2.

[0082] Optionally, when the input-side Cin voltage is low, the flying capacitor C1 voltage is low, while the output-side Cout voltage is high, the energy of the output-side Cout needs to be used to precharge the flying capacitor C1 a second time. Figure 13As shown, the voltage of the flying capacitor C1 is charged to the preset voltage through two circuits: the third resistor R3, the first resistor R1, the first controllable switch T1, the anti-parallel diode, the inductor L1, the input side Cin, and the third resistor R3, the first resistor R1, the third diode D3, and the second resistor R2.

[0083] Example 5

[0084] In some alternative embodiments, such as Figure 14 and Figure 15 As shown, the boost circuit also includes a fourth resistor R4 and a switch K1. One end of the switch K1 is connected to one end of the flying capacitor C1 through the fourth resistor R4, and the other end of the switch K1 is connected to the input terminals.

[0085] In practice, because the secondary pre-charge start-up time of impedance grouping is relatively slow, the secondary pre-charge process of flying capacitor C1 can be completed by active device switching element K1. Figure 14 As shown, during the power-on process on the input side Cin, the voltage of the flying capacitor C1 is charged to the preset voltage through the circuit of inductor L1, first diode D1, flying capacitor C1, fourth resistor R4, and switch K1. However, when the voltage on the output side Cout is higher, as... Figure 15 As shown, the voltage of the flying capacitor C1 can be charged to a preset voltage through the second Zener diode ZD2, the fourth diode D4, the flying capacitor C1, the fourth resistor R4, and the switch K1 circuit. After the voltage of the flying capacitor C1 reaches the preset voltage, the switch K1 disconnects from the main circuit.

[0086] It should be noted that the functional unit devices in the above circuit do not participate in the operation during normal topology operation, and only operate during power-on or abnormal circuit operation, and have no impact on the circuit operation status and system heat.

[0087] Example 6

[0088] In some embodiments, this application also provides an inverter device, including the boost circuit structure described above.

[0089] In implementation, an inverter is a device that converts direct current (DC) into alternating current (AC), and can be used with various AC power sources. Optionally, the inverter includes a switching circuit, a boost main circuit, a boost branch circuit, a first functional circuit 100, and a second functional circuit 200. The switching circuit includes a first controllable switch T1 and a second controllable switch T2 connected in series. One end of the first controllable switch T1 is connected to the input end of the boost circuit through an inductor L1, and the other end of the first controllable switch T1 is connected to one end of the second controllable switch T2. The other end of the second controllable switch T2 is connected to both the input and output ends of the boost circuit. The boost main circuit includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the first controllable switch T1. One end of the circuit is connected to the first diode D1, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to the output end of the boost circuit. The boost circuit includes a flying capacitor C1, one end of which is connected to the other end of the first controllable switch T1, and the other end of which is connected to the cathode of the first diode D1. The first functional circuit 100 is connected to the flying capacitor C1 and the input end, and is used to charge the flying capacitor C1 when the input side of the boost circuit is powered on. The second functional circuit 200 is connected in parallel with the second diode D2, and is used to charge the flying capacitor C1 when the output side of the boost circuit is powered on.

[0090] In implementation, the first and second controllable switches can be power switching transistors. For example, the first controllable switch T1 is a first MOSFET, and the second controllable switch T2 is a second MOSFET. The drain of the first MOSFET is connected to one end of the inductor L1, the source of the first MOSFET is connected to the drain of the second MOSFET, the source of the second MOSFET is connected to the input and output terminals of the boost circuit, and the other end of the inductor L1 is connected to one input terminal of the boost circuit.

[0091] Optionally, the input terminal one and input terminal two of the boost circuit are the two ends of the input side Cin of the boost circuit. For example, the input side Cin of the boost circuit includes a positive input and a negative input, wherein when the input terminal one is a positive input, the input terminal two is a negative input; and when the input terminal one is a negative input, the input terminal two is a positive input.

[0092] Optionally, the anode of the first diode D1 is connected to the drain of the first MOSFET, the cathode of the first diode D1 is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to one output terminal of the boost circuit.

[0093] Optionally, the output terminals one and two of the boost circuit are the two ends of the output side Cout of the boost circuit. For example, the output side Cout of the boost circuit includes a positive output and a negative output, wherein when the output terminal one is a positive output, the output terminal two is a negative output; and when the output terminal one is a negative output, the output terminal two is a positive output.

[0094] Optionally, one end of the flying capacitor C1 is connected to the source of the first MOSFET, that is, one end of the flying capacitor C1 is connected to the line between the first MOSFET and the second MOSFET. The other end of the flying capacitor C1 is connected to the cathode of the first diode D1, that is, the other end of the flying capacitor C1 is connected to the line between the first diode D1 and the second diode D2.

[0095] Optionally, the first functional circuit 100 connects one end of the flying capacitor C1 and the two input terminals. In some possible embodiments, the first functional circuit 100 can be a passive or active device to charge the flying capacitor C1 during the power-on process of the input side Cin, thereby protecting the second controllable switch T2 from overvoltage.

[0096] Optionally, the second functional circuit 200 is connected in parallel with the second diode D2. In some possible embodiments, the second functional circuit 200 can be a passive or active device used to charge the flying capacitor C1 during the power-on process of the output side Cout, thereby protecting the second diode D2 from overvoltage.

[0097] In this embodiment, a boost circuit structure framework is formed by a switching circuit, a boost main circuit, and a boost branch circuit. Then, a first functional circuit 100 is connected to the flying capacitor C1 and the two input terminals to charge the flying capacitor C1 during the power-on process on the input side of the boost circuit, thus protecting the second controllable switch T2 from overvoltage. The second functional circuit 200 is connected in parallel with the second diode D2 to charge the flying capacitor C1 during the power-on process on the output side of the boost circuit, thus protecting the second diode D2 from overvoltage.

[0098] Those skilled in the art will clearly understand that, for the sake of convenience and indirectness, the structure and implementation principle of the inverter device described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments one to five, and will not be repeated here.

[0099] Example 7

[0100] In some embodiments, this application also provides a photovoltaic power generation system, including the inverter device as described above.

[0101] Those skilled in the art will clearly understand that, for the sake of convenience and indirectness, the structure and implementation principle of the photovoltaic power generation system described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments one to six, and will not be repeated here.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A boost circuit structure, characterized in that, include: A switching circuit includes a first controllable switch and a second controllable switch connected in series. One end of the first controllable switch is connected to one input end of a boost circuit through an inductor. The other end of the first controllable switch is connected to one end of the second controllable switch. The other end of the second controllable switch is connected to both input ends and both output ends of the boost circuit. The boost main circuit includes a first diode and a second diode. The anode of the first diode is connected to one end of the first controllable switch, the cathode of the first diode is connected to the anode of the second diode, and the cathode of the second diode is connected to one output end of the boost circuit. The boost circuit includes a flying capacitor, one end of which is connected to the other end of the first controllable switch, and the other end of which is connected to the cathode of the first diode. The first functional circuit is connected to one end of the flying capacitor and the two input terminals, and is used to charge the flying capacitor when the input side of the boost circuit is powered on. The second functional circuit, connected to the first functional circuit and in parallel with the second diode, is used to charge the flying capacitor when the output side of the boost circuit is powered on. The first functional circuit includes a first Zener diode and a third diode; The cathode of the first Zener diode is connected to the cathode of the third diode, and is connected to one end of the flying capacitor through the third diode; the anode of the first Zener diode is connected to the two input terminals. The second functional circuit includes a second Zener diode; The anode of the second Zener diode is connected to the anode of the second diode and the cathode of the first Zener diode, and the cathode of the second Zener diode is connected to the cathode of the second diode.

2. The boost circuit structure as described in claim 1, characterized in that, The second functional circuit also includes a fourth diode; The anode of the second Zener diode is connected to the anode of the fourth diode, and is also connected to the anode of the second diode through the fourth diode.

3. The boost circuit structure as described in claim 2, characterized in that, The boost circuit further includes a first resistor, and the first functional circuit further includes a second resistor; The first resistor is connected in parallel with the flying capacitor; The second resistor is connected in parallel with the first Zener diode.

4. The boost circuit structure as described in claim 3, characterized in that, The second functional circuit also includes a third resistor, which is connected in parallel with the second diode.

5. The boost circuit structure as described in claim 2, characterized in that, The boost circuit also includes a fourth resistor and a switch. One end of the switch is connected to one end of the flying capacitor through the fourth resistor, and the other end of the switch is connected to the input terminals.

6. An inverter device, characterized in that, Includes the boost circuit structure as described in claim 1.

7. A photovoltaic power generation system, characterized in that, Including the inverter device as described in claim 6.

Images