Photovoltaic energy storage inverter circuit and photovoltaic energy storage device

Abstract

The utility model provides a kind of photovoltaic energy storage converter circuit and photovoltaic energy storage equipment. Among them, photovoltaic energy storage converter circuit includes: multiple boost circuits, the first end of each boost circuit is connected with photovoltaic module, multiple boost circuits are mutually parallel between;Multiple first switches, the first end of each first switch is connected with the anode of each photovoltaic module, the second end of each first switch is connected with the third end of each boost circuit;Buck circuit, the first end of buck circuit is connected with the second end of multiple boost circuits respectively, the second end of buck circuit is connected with battery;Bidirectional DCDC circuit, the first end of bidirectional DCDC circuit is connected with the second end of buck circuit;Inverter circuit, the first end of inverter circuit is connected with the second end of bidirectional DCDC circuit, the second end of inverter circuit is connected with power grid. The utility model reduces the number of switch tube, reduces system cost, improves system efficiency simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, and more specifically, to a photovoltaic energy storage converter circuit and a photovoltaic energy storage device. Background Technology

[0002] Driven by relevant policies and the market boom, there are higher requirements for the power efficiency, cost, and quality of balcony photovoltaic (PV) energy storage. The input ports of balcony PV energy storage have evolved from single panels to multiple panels connected in series and parallel. The operating voltage range of PV (Photovoltaic) has widened from 16V to 60V. The single-channel PV current has increased from 14A to 28A. The number of channels in balcony PV energy storage has increased from 2 to 4. The batteries used in balcony PV energy storage have evolved from 48V to 25.2V or even 16V. Each of these changes significantly impacts the internal design of balcony PV energy storage. However, in related technologies, each PV circuit consists of boost and buck circuits, resulting in a large number of switching transistors, leading to higher system costs and lower system efficiency. Utility Model Content

[0003] The present invention aims to solve the technical problems existing in the prior art or related technologies.

[0004] Therefore, the first aspect of this utility model proposes a photovoltaic energy storage converter circuit.

[0005] The second aspect of this utility model proposes a photovoltaic energy storage device.

[0006] In view of the above, according to the first aspect of this utility model, a photovoltaic energy storage converter circuit is proposed, wherein the photovoltaic energy storage converter circuit includes: multiple boost circuits, the first terminal of each boost circuit being connected to a photovoltaic module, and the multiple boost circuits being connected in parallel; multiple first switches, the first terminal of each first switch being connected to the positive terminal of each photovoltaic module, and the second terminal of each first switch being connected to the third terminal of each boost circuit; a buck circuit, the first terminal of the buck circuit being connected to the second terminal of each of the multiple boost circuits, and the second terminal of the buck circuit being connected to a battery; a bidirectional DC-DC circuit, the first terminal of the bidirectional DC-DC circuit being connected to the second terminal of the buck circuit; and an inverter circuit, the first terminal of the inverter circuit being connected to the second terminal of the bidirectional DC-DC circuit, and the second terminal of the inverter circuit being connected to the power grid.

[0007] In some technical solutions, optionally, the boost circuit includes: a first capacitor, the first terminal of which is connected to the positive terminal of the photovoltaic module, and the second terminal of which is connected to the negative terminal of the photovoltaic module; a first inductor, the first terminal of which is connected to the first terminal of the first capacitor; a first switch, the first terminal of which is connected to the second terminal of the first inductor, and the second terminal of which is connected to the first terminal of the buck circuit and the second terminal of the first switch; and a second switch, the first terminal of which is connected to the second terminal of the first inductor, and the second terminal of which is connected to the second terminal of the buck circuit and the second terminal of the first capacitor.

[0008] In some technical solutions, optionally, the step-down circuit includes: a third switching transistor, the first terminal of which is connected to the second terminal of the first switching transistor and the positive terminal of the battery; a fourth switching transistor, the first terminal of which is connected to the second terminal of the third switching transistor, and the second terminal of which is connected to the second terminal of the second switching transistor and the negative terminal of the battery; and a second inductor, the first terminal of which is connected to the second terminal of the third switching transistor and the first terminal of the fourth switching transistor, and the second terminal of which is connected to the positive terminal of the battery.

[0009] In some technical solutions, the step-down circuit may optionally include a second switch, the first terminal of which is connected to the first terminal of the third switch.

[0010] In some technical solutions, the photovoltaic energy storage converter circuit may optionally include: a second capacitor, the first terminal of which is connected to the first terminal of the first switching transistor and the first terminal of the third switching transistor respectively; and the second terminal of the second capacitor is connected to the second terminal of the second switching transistor and the second terminal of the fourth switching transistor respectively.

[0011] In some technical solutions, optionally, the bidirectional DC-DC circuit includes: a first full-bridge circuit, the first terminal of which is connected to the second terminal of the step-down circuit; a transformer, the first terminal of which is connected to the second terminal of the first full-bridge circuit; a resonant cavity circuit, the first terminal of which is connected to the second terminal of the transformer; and a second full-bridge circuit, the first terminal of which is connected to the second terminal of the resonant cavity circuit, and the second terminal of which is connected to the first terminal of the inverter circuit.

[0012] In some technical solutions, the resonant cavity circuit may optionally include: a third inductor, the first end of which is connected to the second end of the transformer; and a third capacitor, the first end of which is connected to the second end of the third inductor, and the second end of which is connected to the first end of the second full-bridge circuit.

[0013] In some technical solutions, the inverter circuit may optionally include: a third full-bridge circuit, the first terminal of which is connected to the second terminal of the bidirectional DC-DC circuit; and an inverter inductor, the first terminal of which is connected to the second terminal of the third full-bridge circuit, and the second terminal of which is connected to the power grid.

[0014] In some technical solutions, the inverter circuit may optionally include a third switch, the first terminal of which is connected to the second terminal of the inverter inductor, and the second terminal of which is connected to the power grid.

[0015] According to a second aspect of the present invention, a photovoltaic energy storage device is provided, comprising a photovoltaic energy storage converter circuit as described in any of the above claims.

[0016] The photovoltaic energy storage device provided by this utility model includes a photovoltaic energy storage converter circuit as described above, which can achieve the technical effects of any of the above technical solutions, and will not be described in detail here.

[0017] Additional aspects and advantages of this invention will become apparent in the description that follows, or may be learned by practice of this invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This shows one of the structural schematic diagrams of a photovoltaic energy storage converter circuit related to the technology;

[0020] Figure 2 This is the second schematic diagram of the structure of a photovoltaic energy storage converter circuit based on related technologies;

[0021] Figure 3 One of the schematic diagrams of a photovoltaic energy storage converter circuit according to an embodiment of the present invention is shown;

[0022] Figure 4 A second schematic diagram of the structure of a photovoltaic energy storage converter circuit according to an embodiment of the present invention is shown;

[0023] Figure 5 A structural block diagram of a photovoltaic energy storage device according to an embodiment of the present invention is shown;

[0024] in, Figures 1 to 5 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0025] 100' Photovoltaic energy storage converter circuit, 102' First boost circuit, 104' Second boost circuit, 106' First buck circuit, 108' First bidirectional DC-DC circuit, 10 Photovoltaic energy storage device, 100 Photovoltaic energy storage converter circuit, 102 boost circuit, 104 buck circuit, 106 bidirectional DC-DC circuit, 108 inverter circuit, 110 First full-bridge circuit, T1 transformer, 112 resonant cavity circuit, 114 Second full-bridge circuit, 116 Third full-bridge circuit, Q1 First switch, Q2 Second switch, Q3 Third switch, Q4 Fourth switch, Q5 Fifth switch, Q6 Sixth switch, Q7 Seventh switch, Q8 Eighth switch, Q9 Ninth switch, Q10 Tenth switch, Q11 Eleventh switch, Q12 Twelfth switch, Q13 Thirteenth switch, Q14 Fourteenth switch, Q15 Fifteenth switch. Q16 is the sixteenth switch, Q17 is the seventeenth switch, Q18 is the eighteenth switch, Q19 is the nineteenth switch, Q20 is the twentieth switch, Q21 is the twenty-first switch, Q22 is the twenty-second switch, C1 is the first capacitor, C2 is the second capacitor, C3 is the third capacitor, C4 is the fourth capacitor, C5 is the fifth capacitor, C6 is the sixth capacitor, S1 is the first switch, S2 is the second switch, S3 is the third switch, S4 is the fourth switch, S5 is the fifth switch, S6 is the sixth switch, L1 is the first inductor, L2 is the second inductor, L3 is the third inductor, L4 is the fourth inductor, L5 is the fifth inductor, L6 is the sixth inductor, L7 is the inverter inductor, PV+ is the positive terminal of the photovoltaic module, PV- is the negative terminal of the photovoltaic module, BAT+ is the positive terminal of the battery, BAT- is the negative terminal of the battery, Grid_L is the live wire of the power grid, Grid_N is the neutral wire of the power grid, EPS_L is the live wire of the emergency power supply, EPS_N is the neutral wire of the emergency power supply. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of this utility model and the features thereof can be combined with each other.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0028] Figure 1 This shows one of the structural schematic diagrams of a photovoltaic energy storage converter circuit based on related technologies, such as... Figure 1As shown, the first boost circuit 102' in the photovoltaic energy storage converter circuit 100' is directly connected to the first bidirectional DC-DC circuit 108', that is, the photovoltaic voltage generated by the photovoltaic module is directly transmitted to the battery after being boosted. Figure 2 The second schematic diagram of the photovoltaic energy storage converter circuit of the relevant technology is shown, such as... Figure 2 As shown, each second boost circuit 104' is connected to a first buck circuit 106'. This means that each photovoltaic module needs to be boosted by the second boost circuit 104', then stepped down by the first buck circuit 106', and finally the voltage is combined to charge the battery. However, in related technologies, because each PV circuit consists of a second boost circuit 104' and a first buck circuit 106', the number of switching transistors is large, resulting in higher system cost and lower system efficiency.

[0029] like Figure 3 and Figure 4 As shown, this utility model proposes a photovoltaic energy storage converter circuit 100, which includes: multiple boost circuits 102, each boost circuit 102 having a first terminal connected to a photovoltaic module, and the multiple boost circuits 102 being connected in parallel; multiple first switches S1, each first switch S1 having a first terminal connected to the positive electrode PV+ of each photovoltaic module, and each first switch S1 having a second terminal connected to the third terminal of each boost circuit 102; a buck circuit 104, the buck circuit 104 having a first terminal connected to the second terminal of each of the multiple boost circuits 102, and the buck circuit 104 having a second terminal connected to a battery; a bidirectional DC-DC converter circuit 106, the bidirectional DC-DC converter circuit 106 having a first terminal connected to the second terminal of the buck circuit 104; and an inverter circuit 108, the inverter circuit 108 having a first terminal connected to the second terminal of the bidirectional DC-DC converter circuit 106, and the inverter circuit 108 having a second terminal connected to the power grid.

[0030] The photovoltaic energy storage converter circuit 100 provided by this utility model mainly includes: multiple boost circuits 102, multiple first switches S1, a buck circuit 104, a bidirectional DC-DC (Direct Current to Direct Current Converter) circuit, and an inverter circuit 108. Each boost circuit 102 has its first terminal connected to a photovoltaic module, and the boost circuit 102 can boost the photovoltaic voltage output by the connected photovoltaic module. The multiple boost circuits 102 are connected in parallel. Each first switch S1 has its first terminal connected to the positive terminal PV+ of each photovoltaic module, and its second terminal connected to the third terminal of each boost circuit 102. The third terminal of the boost circuit 102 can be a low-voltage bus. In pure photovoltaic power generation mode without batteries, the first switch S1 is closed, allowing the photovoltaic module to be directly connected to the low-voltage bus, thereby reducing circuit losses and improving overall efficiency. The first terminal of the buck circuit 104 is connected to the second terminals of multiple boost circuits 102, and the second terminal of the buck circuit 104 is connected to the battery. That is, the photovoltaic voltage output from each photovoltaic module is boosted by the boost circuit 102, then the boosted photovoltaic voltages are aggregated, and the buck circuit 104 is used to step down the aggregated photovoltaic voltage so that the photovoltaic voltage matches the battery voltage, thereby charging the battery. The first terminal of the bidirectional DC-DC circuit 106 is connected to the second terminal of the buck circuit 104, and the second terminal of the bidirectional DC-DC circuit 106 is connected to the first terminal of the inverter circuit 108. The bidirectional DC-DC circuit 106 is used to achieve electrical isolation and bidirectional energy flow. The first terminal of the inverter circuit 108 is connected to the second terminal of the bidirectional DC-DC circuit 106, and the second terminal of the inverter circuit 108 is connected to the power grid. This invention utilizes multiple boost circuits 102 connected in parallel, which are then connected to a buck circuit 104. This reduces the number of buck circuits 104 compared to related technologies, thereby lowering system costs and improving system efficiency. Furthermore, by incorporating a first switch S1, this invention allows the photovoltaic modules to be directly connected to the low-voltage bus in pure photovoltaic power generation mode, further enhancing overall system efficiency.

[0031] In some embodiments, optionally, such as Figure 3 and Figure 4As shown, the boost circuit 102 includes: a first capacitor C1, the first end of which is connected to the positive terminal PV+ of the photovoltaic module, and the second end of which is connected to the negative terminal PV- of the photovoltaic module; a first inductor L1, the first end of which is connected to the first end of the first capacitor C1; a first switch Q1, the first end of which is connected to the second end of the first inductor L1, and the second end of which is connected to the first end of the buck circuit 104 and the second end of the first switch S1; and a second switch Q2, the first end of which is connected to the second end of the first inductor L1, and the second end of which is connected to the second end of the buck circuit 104 and the second end of the first switch S1; and a second switch Q2, the first end of which is connected to the second end of the first inductor L1, and the second end of which is connected to the second end of the buck circuit 104 and the second end of the first capacitor C1.

[0032] In this embodiment, the boost circuit 102 includes a first capacitor C1, a first inductor L1, a first switch Q1, and a second switch Q2. The first terminal of the first capacitor C1 is connected to the positive terminal PV+ of the photovoltaic module, and the second terminal of the first capacitor C1 is connected to the negative terminal PV- of the photovoltaic module. The first capacitor C1 smooths out fluctuations in the photovoltaic voltage output by the photovoltaic module, ensuring the stability of subsequent circuit operation. The first terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1. The second terminal of the first inductor L1 is connected to the first terminal of both the first switch Q1 and the first terminal of the second switch Q2. The second terminal of the first switch Q1 is connected to both the first terminal of the buck circuit 104 and the second terminal of the first switch S1, meaning the second terminal of the first switch Q1 is connected to the positive bus. The second terminal of the second switch Q2 is connected to both the second terminal of the buck circuit 104 and the second terminal of the first capacitor C1, meaning the second terminal of the second switch Q2 is connected to the negative bus. By employing high-frequency alternating switching operations of the first inductor L1, the first switch Q1, and the second switch Q2, energy storage and release are achieved in the inductors, thereby boosting the photovoltaic voltage output by the photovoltaic module to a bus voltage higher than the battery voltage, creating conditions for subsequent buck or direct-drive modes. In boost mode, when the second switch Q2 is turned on, the first inductor L1 stores energy; when the first switch Q1 is turned on, the first inductor L1 releases energy to the bus. Compared to related technologies, this invention, by setting the boost circuit 102 including the first capacitor C1, the first inductor L1, the first switch Q1, and the second switch Q2, reduces the number of power devices and lowers switching losses.

[0033] In some embodiments, optionally, such as Figure 3 and Figure 4As shown, the step-down circuit 104 includes: a third switch Q3, the first terminal of which is connected to the second terminal of the first switch Q1 and the positive terminal of the battery; a fourth switch Q4, the first terminal of which is connected to the second terminal of the third switch Q3, and the second terminal of which is connected to the second terminal of the second switch Q2 and the negative terminal of the battery; and a second inductor L2, the first terminal of which is connected to the second terminal of the third switch Q3 and the first terminal of the fourth switch Q4, and the second terminal of which is connected to the positive terminal of the battery.

[0034] In this embodiment, the step-down circuit 104 includes a third switch Q3, a fourth switch Q4, and a second inductor L2. The first terminal of the third switch Q3 is connected to the second terminal of the first switch Q1 and the positive terminal of the battery, i.e., the first terminal of the third switch Q3 is connected to the positive bus. The second terminal of the third switch Q3 is connected to the first terminal of the fourth switch Q4 and the first terminal of the second inductor L2. The first terminal of the fourth switch Q4 is connected to the second terminal of the third switch Q3, and the second terminal of the fourth switch Q4 is connected to the second terminal of the second switch Q2 and the negative terminal of the battery, i.e., the second terminal of the fourth switch Q4 is connected to the negative bus. The first terminal of the second inductor L2 is connected to the second terminals of both the third switch Q3 and the fourth switch Q4, and the second terminal of the second inductor L2 is connected to the positive terminal of the battery, i.e., the second terminal of the second inductor L2 is connected to the positive bus. This invention achieves efficient energy conversion and voltage adaptation by setting a third switch Q3, a fourth switch Q4, and a second inductor L2 in the step-down circuit 104.

[0035] In some embodiments, optionally, such as Figure 3 and Figure 4 As shown, the step-down circuit 104 also includes a second switch S2, the first end of which is connected to the first end of the third switch Q3.

[0036] In this embodiment, the step-down circuit 104 further includes a second switch S2. The first terminal of the second switch S2 is connected to the first terminal of the third switch Q3, and the second terminal of the second switch S2 is connected to both the second terminal of the second inductor L2 and the positive terminal of the battery. When the photovoltaic voltage is higher than the battery voltage, the second switch S2 can be in a closed state, thus forming a DC channel with the battery. This allows energy to bypass the switch in the step-down circuit 104 and be directly transferred to the battery, thereby reducing switching losses and core losses. This invention, by adding a second switch S2 to the step-down circuit 104, achieves a direct-through function, thereby significantly improving system efficiency and reducing energy consumption.

[0037] In some embodiments, optionally, such as Figure 3 and Figure 4As shown, the photovoltaic energy storage converter circuit 100 further includes: a second capacitor C2, the first end of which is connected to the first end of the first switch Q1 and the first end of the third switch Q3 respectively; and the second end of the second capacitor C2 is connected to the second end of the second switch Q2 and the second end of the fourth switch Q4 respectively.

[0038] In this embodiment, the photovoltaic energy storage converter circuit 100 further includes a second capacitor C2. The first terminal of the second capacitor C2 is connected to the first terminal of the first switch Q1 and the first terminal of the third switch Q3, respectively. The second terminal of the second capacitor C2 is connected to the second terminal of the second switch Q2 and the second terminal of the fourth switch Q4, respectively. That is, the first terminal of the second capacitor C2 is connected to the positive bus, and the second terminal of the second capacitor C2 is connected to the negative bus. By setting the second capacitor C2, the voltage input to the buck circuit 104 and the boost circuit 102 can be filtered, thereby improving system stability and efficiency.

[0039] In some embodiments, optionally, such as Figure 3 and Figure 4 As shown, the bidirectional DC-DC circuit 106 includes: a first full-bridge circuit 110, the first terminal of which is connected to the second terminal of the step-down circuit 104; a transformer T1, the first terminal of which is connected to the second terminal of the first full-bridge circuit 110; a resonant cavity circuit 112, the first terminal of which is connected to the second terminal of the transformer T1; and a second full-bridge circuit 114, the first terminal of which is connected to the second terminal of the resonant cavity circuit 112, and the second terminal of which is connected to the first terminal of the inverter circuit 108.

[0040] In this embodiment, the bidirectional DC-DC circuit 106 includes: a first full-bridge circuit 110, a transformer T1, a resonant cavity circuit 112, and a second full-bridge circuit 114. The first terminal of the first full-bridge circuit 110 is connected to the second terminal of the step-down circuit 104, and is also connected to a battery. The second terminal of the first full-bridge circuit 110 is connected to the transformer T1. The first full-bridge circuit 110 can increase the DC voltage frequency. The first terminal of the transformer T1 is connected to the second terminal of the first full-bridge circuit 110, and the second terminal of the transformer T1 is connected to the resonant cavity circuit 112. The transformer T1 provides electrical isolation and energy transfer, effectively ensuring system safety. The first terminal of the resonant cavity circuit 112 is connected to the second terminal of the transformer T1, and the second terminal of the resonant cavity circuit 112 is connected to the second full-bridge circuit 114. The resonant cavity circuit 112 can adjust its impedance characteristics at the switching frequency to operate in a soft-switching state, significantly reducing switching losses. The first terminal of the second full-bridge circuit 114 is connected to the second terminal of the resonant cavity circuit 112, and the second terminal of the second full-bridge circuit 114 is connected to the first terminal of the inverter circuit 108. The second full-bridge circuit 114 can rectify and / or invert the output voltage of the transformer T1, supporting bidirectional energy flow to the inverter circuit 108 or the battery. This invention achieves efficient bidirectional energy transmission and electrical isolation between the high and low voltage sides by setting the first full-bridge circuit 110, the transformer T1, the resonant cavity circuit 112, and the second full-bridge circuit 114 in the bidirectional DC-DC circuit 106.

[0041] In some embodiments, optionally, such as Figure 3 and Figure 4 As shown, the resonant cavity circuit 112 includes: a third inductor L3, the first end of which is connected to the second end of the transformer T1; a third capacitor C3, the first end of which is connected to the second end of the third inductor L3, and the second end of which is connected to the first end of the second full-bridge circuit 114.

[0042] In this embodiment, the resonant cavity circuit 112 includes a third inductor L3 and a third capacitor C3. The first terminal of the third inductor L3 is connected to the second terminal of the transformer T1, the second terminal of the third inductor L3 is connected to the first terminal of the third capacitor C3, and the second terminal of the third capacitor C3 is connected to the first terminal of the second full-bridge circuit 114. By configuring the resonant cavity circuit 112 to consist of the third inductor L3 and the third capacitor C3 connected in series, efficient soft-switching operation and precise power regulation of the bidirectional DC-DC circuit 106 are achieved.

[0043] In some embodiments, optionally, such as Figure 3 and Figure 4As shown, the inverter circuit 108 includes: a third full-bridge circuit 116, the first terminal of which is connected to the second terminal of the bidirectional DC-DC circuit 106; and an inverter inductor L7, the first terminal of which is connected to the second terminal of the third full-bridge circuit 116, and the second terminal of which is connected to the power grid.

[0044] In this embodiment, the inverter circuit 108 includes a third full-bridge circuit 116 and an inverter inductor L7. The first terminal of the third full-bridge circuit 116 is connected to the second terminal of the bidirectional DC-DC converter 106, the second terminal of the third full-bridge circuit 116 is connected to the first terminal of the inverter inductor L7, and the second terminal of the inverter inductor L7 is connected to the power grid. This invention, by incorporating the third full-bridge circuit 116 and the inverter inductor L7 into the inverter circuit 108, achieves efficient and stable conversion of direct current to alternating current.

[0045] In some embodiments, optionally, such as Figure 3 and Figure 4 As shown, the inverter circuit 108 also includes a third switch S3, the first end of which is connected to the second end of the inverter inductor L7, and the second end of which is connected to the power grid.

[0046] In this embodiment, the inverter circuit 108 further includes a third switch S3. The first terminal of the third switch S3 is connected to the second terminal of the inverter inductor L7, and the second terminal of the third switch S3 is connected to the power grid. The third switch S3 can control the connection between the photovoltaic energy storage converter circuit 100 and the power grid, realizing safe and reliable switching between grid-connected and off-grid operating modes of the photovoltaic energy storage converter circuit 100. For example, the third switch S3 can be connected to the grid's live wire Grid_L, the grid's neutral wire Grid_N, the emergency power supply's live wire EPS_L, and the emergency power supply's neutral wire EPS_N, respectively.

[0047] For example, such as Figure 3 and Figure 4As shown, this utility model comprises three main parts: a PV circuit, a bidirectional DC-DC circuit 106, and an inverter circuit 108. The PV circuit includes four boost circuits 102 and a buck circuit 104. The boost circuit 102 includes a first switch Q1, a second switch Q2, a first inductor L1, and a first capacitor C1 in branch 1; a fifth switch Q5, a sixth switch Q6, a fourth inductor L4, and a fourth capacitor C4 in branch 2; a seventh switch Q7, an eighth switch Q8, a fifth inductor L5, and a fifth capacitor C5 in branch 3; and a ninth switch Q9, a tenth switch Q10, a sixth inductor L6, and a sixth capacitor C6 in branch 4. The buck circuit 104 includes a third switch Q3, a fourth switch Q10, and a second inductor L2. The PV circuit also includes bypass switches, which include a first switch S1, a second switch S2, a fourth switch S4, a fifth switch S5, and a sixth switch S6, reducing circuit losses and improving overall efficiency. The boost circuit 102 serves to boost the voltage. High-frequency switching transistors Q1, Q2, Q5, Q6, Q7, Q8, Q9, and Q10 amplify the input voltage, storing energy in inductors L1, L4, L5, and L6. When transistors Q2, Q6, Q7, and Q10 are on, transistors Q1, Q5, Q8, and Q9 are off, and inductors L1, L4, L5, and L6 store energy. When the first switch Q1, the fifth switch Q5, the eighth switch Q8, and the ninth switch Q9 are turned on, and the second switch Q2, the sixth switch Q6, the seventh switch Q7, and the tenth switch Q10 are turned off, the first inductor L1, the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 release energy. The step-down circuit 104 serves to reduce the voltage. When the third switch Q3 is turned on and the fourth switch Q4 is turned off, the second inductor L2 stores energy. When the third switch Q3 is turned off and the fourth switch Q4 is turned on, the second inductor L2 releases energy.

[0048] The bidirectional DC-DC circuit 106 includes a first full-bridge circuit 110 on the battery side, which consists of an eleventh switch Q11, a twelfth switch Q12, a thirteenth switch Q13, a fourteenth switch Q14, and a seventh capacitor. Switches Q1 and Q13 switch simultaneously, as do Q12 and Q14. This circuit primarily provides the input voltage at a higher frequency to the high-frequency transformer T1. The high-frequency transformer T1 serves to transfer energy between the two sides and provide electrical isolation. The resonant cavity circuit 112 consists of a third inductor L3 and a third capacitor C3, serving to store energy and adjust the circuit impedance. The second full-bridge circuit 114 on the high-voltage side includes a fifteenth switch Q15, a sixteenth switch Q16, a seventeenth switch Q17, and an eighteenth switch Q18. The sixteenth switch Q16 and the seventeenth switch Q17 switch simultaneously, and the fifteenth switch Q15 and the eighteenth switch Q18 switch simultaneously, to make the voltage on the high-voltage side more frequent and complete the energy transfer between the high-voltage and low-voltage sides.

[0049] The inverter circuit 108 comprises a third full-bridge circuit 116, an inverter inductor L7, and a third switch S3. The third full-bridge circuit 116 converts the DC voltage to a high frequency to store and release energy in the inverter inductor L7. The nineteenth switch Q19 and the twentieth switch Q20 are power frequency transistors. The switching signals of the nineteenth switch Q19 and the twentieth switch Q20 are complementary. During the positive half-cycle of the output, the twentieth switch Q20 is on and the nineteenth switch Q19 is off; during the negative half-cycle of the output, the twentieth switch Q20 is off and the nineteenth switch Q19 is on. The twenty-first switch Q21 and the twenty-second switch Q22 are high-frequency transistors, switching at high frequency at any given time, and their switching signals are complementary. The output switch is responsible for connecting and disconnecting the inverter output from the off-grid port and the grid-connected port.

[0050] like Figure 3 and Figure 4 As shown, in boost mode, when the second switch Q2, the sixth switch Q6, the seventh switch Q7, and the tenth switch Q10 are turned on, the first inductor L1, the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 store energy, while the first switch Q1, the fifth switch Q5, the eighth switch Q8, and the ninth switch Q9 are turned off. When the first switch Q1, the fifth switch Q5, the eighth switch Q8, and the ninth switch Q9 are turned on, the first inductor L1, the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 release energy, while the second switch Q2, the sixth switch Q6, the seventh switch Q7, and the tenth switch Q10 are turned off; the third switch Q3 and the fourth switch Q4 are turned off, and the second switch S2 is closed; simultaneously, the fourth switch S4, the first switch S1, the fifth switch S5, and the sixth switch S6 are turned off.

[0051] In buck mode, when the second switch Q2, the sixth switch Q6, the seventh switch Q7, and the tenth switch Q10 are turned on, the first inductor L1, the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 store energy, while the first switch Q1, the fifth switch Q5, the eighth switch Q8, and the ninth switch Q9 are turned off. When the first switch Q1, the fifth switch Q5, the eighth switch Q8, and the ninth switch Q9 are turned on, the first inductor L1, the fourth inductor L4, the fifth inductor L5, and the sixth inductor L6 release energy, while the second switch Q2, the sixth switch Q6, the seventh switch Q7, and the tenth switch Q10 are turned off. The third switch Q3 and the fourth switch Q4 switch at high frequency, and the second switch S2 is turned off. At the same time, the fourth switch S4, the first switch S1, the fifth switch S5, and the sixth switch S6 are turned off. When the third switch Q3 is turned on and the fourth switch Q4 is turned off, the second inductor L2 stores energy; when the third switch Q3 is turned off and the fourth switch Q4 is turned on, the second inductor L2 releases energy.

[0052] In the direct-through mode: the second switch S2, the fourth switch S4, the first switch S1, the fifth switch S5 and the sixth switch S6 are closed, and the first switch Q1, the second switch Q2, the fifth switch Q5, the sixth switch Q6, the third switch Q3, the fourth switch Q4, the seventh switch Q7, the eighth switch Q8, the ninth switch Q9 and the tenth switch Q10 are open.

[0053] The bidirectional DC-DC circuit 106 operates as follows: When the eleventh switch Q11, twelfth switch Q12, thirteenth switch Q13, and fourteenth switch Q14 are switched at high frequency, the eleventh switch Q11 and the thirteenth switch Q13 switch simultaneously, the twelfth switch Q12 and the fourteenth switch Q14 switch simultaneously, the drive signals of the thirteenth switch Q13 and the fourteenth switch Q14 are complementary, and the drive signals of the eleventh switch Q11 and the twelfth switch Q12 are complementary. The eleventh switch Q11, the twelfth switch Q12, the thirteenth switch Q13, and the fourteenth switch Q14 transmit the input voltage at a high frequency to the high-frequency transformer T1, which then delivers it to the high-voltage side. When the fifteenth switch Q15, the sixteenth switch Q16, the seventeenth switch Q17, and the eighteenth switch Q18 are switched at high frequency, the seventeenth switch Q17 and the sixteenth switch Q16 switch simultaneously, the fifteenth switch Q15 and the eighteenth switch Q18 switch simultaneously, and the drive signals of the seventeenth switch Q17 and the eighteenth switch Q18 are complementary. The high-frequency DC square wave of the fifteenth switch Q15, the sixteenth switch Q16, the seventeenth switch Q17, and the eighteenth switch Q18 is rectified into DC. The impedance of the third inductor L3 and the third capacitor C3 in the resonant cavity circuit 112 changes with the switching frequency, directly affecting the output voltage and power.

[0054] The inverter circuit 108 operates as follows: during the positive half-cycle of the output AC voltage, the twentieth switch Q20 is turned on, and the nineteenth switch Q19 is turned off. Switches Q19 and Q20 switch on and off according to the power frequency cycle. The twenty-first and twenty-second high-frequency switches Q21 and Q22 perform high-frequency switching. When Q21 is on and Q22 is off, the inverter inductor L7 stores energy; when Q22 is on and Q21 is off, the inverter inductor L7 releases energy.

[0055] During the negative half-cycle of the output AC voltage: the nineteenth switch Q19 is on, and the twentieth switch Q20 is off. Switches Q19 and Q20 switch according to the power frequency cycle. The twenty-first and twenty-second high-frequency switches Q21 and Q22 switch frequently. When Q22 is on and Q21 is off, the inverter inductor L7 stores energy; when Q21 is on and Q22 is off, the inverter inductor L7 releases energy.

[0056] like Figure 5 As shown, this utility model proposes a photovoltaic energy storage device 10, including a photovoltaic energy storage converter circuit 100 as described in any of the above claims.

[0057] The photovoltaic energy storage device 10 provided by this utility model includes a photovoltaic energy storage converter circuit 100 as described in any of the above embodiments, and can achieve the technical effects of any of the above embodiments, which will not be repeated here.

[0058] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, unless otherwise expressly specified and limited. The terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0059] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A photovoltaic energy storage converter circuit, characterized in that, include: Multiple boost circuits, each of which has its first terminal connected to a photovoltaic module, and the multiple boost circuits are connected in parallel with each other; Multiple first switches, each first switch having a first terminal connected to the positive terminal of each photovoltaic module, and each first switch having a second terminal connected to the third terminal of each boost circuit; A step-down circuit, wherein the first terminal of the step-down circuit is connected to the second terminal of a plurality of boost circuits respectively, and the second terminal of the step-down circuit is connected to a battery; A bidirectional DC-DC circuit, wherein the first terminal of the bidirectional DC-DC circuit is connected to the second terminal of the step-down circuit; An inverter circuit, wherein the first terminal of the inverter circuit is connected to the second terminal of the bidirectional DC-DC circuit, and the second terminal of the inverter circuit is connected to the power grid.

2. The photovoltaic energy storage converter circuit according to claim 1, characterized in that, The boost circuit includes: A first capacitor, wherein a first terminal of the first capacitor is connected to the positive terminal of the photovoltaic module, and a second terminal of the first capacitor is connected to the negative terminal of the photovoltaic module; The first inductor, the first end of the first inductor is connected to the first end of the first capacitor; The first switching transistor has a first terminal connected to the second terminal of the first inductor, and the second terminal of the first switching transistor is connected to the first terminal of the step-down circuit and the second terminal of the first switch, respectively. The second switching transistor has its first terminal connected to the second terminal of the first inductor, and its second terminal connected to the second terminal of the step-down circuit and the second terminal of the first capacitor.

3. The photovoltaic energy storage converter circuit according to claim 2, characterized in that, The step-down circuit includes: The third switch is connected at its first end to the second end of the first switch and the positive terminal of the battery. A fourth switch transistor, the first end of which is connected to the second end of the third switch transistor, and the second end of the fourth switch transistor is connected to the second end of the second switch transistor and the negative terminal of the battery, respectively; The second inductor has its first end connected to the second end of the third switch and the first end of the fourth switch, respectively, and its second end connected to the positive terminal of the battery.

4. The photovoltaic energy storage converter circuit according to claim 3, characterized in that, The step-down circuit also includes: The second switch has its first end connected to the first end of the third switch tube.

5. The photovoltaic energy storage converter circuit according to claim 4, characterized in that, The photovoltaic energy storage converter circuit also includes: The second capacitor has its first terminal connected to the first terminal of the first switch and the first terminal of the third switch, respectively; and its second terminal connected to the second terminal of the second switch and the second terminal of the fourth switch, respectively.

6. The photovoltaic energy storage converter circuit according to any one of claims 1 to 5, characterized in that, The bidirectional DC-DC circuit includes: A first full-bridge circuit, wherein the first terminal of the first full-bridge circuit is connected to the second terminal of the buck circuit; A transformer, wherein the first terminal of the transformer is connected to the second terminal of the first full-bridge circuit; A resonant cavity circuit, wherein the first end of the resonant cavity circuit is connected to the second end of the transformer; The second full-bridge circuit has its first terminal connected to the second terminal of the resonant cavity circuit, and its second terminal connected to the first terminal of the inverter circuit.

7. The photovoltaic energy storage converter circuit according to claim 6, characterized in that, The resonant cavity circuit includes: The third inductor, the first end of which is connected to the second end of the transformer; The third capacitor has its first terminal connected to the second terminal of the third inductor, and its second terminal connected to the first terminal of the second full-bridge circuit.

8. The photovoltaic energy storage converter circuit according to any one of claims 1 to 5, characterized in that, The inverter circuit includes: The third full-bridge circuit, wherein the first terminal of the third full-bridge circuit is connected to the second terminal of the bidirectional DC-DC circuit; An inverter inductor, the first end of which is connected to the second end of the third full-bridge circuit, and the second end of which is connected to the power grid.

9. The photovoltaic energy storage converter circuit according to claim 8, characterized in that, The inverter circuit also includes: The third switch has its first terminal connected to the second terminal of the inverter inductor, and its second terminal connected to the power grid.

10. A photovoltaic energy storage device, characterized in that, include: The photovoltaic energy storage converter circuit as described in any one of claims 1 to 9.

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