Photovoltaic panel edge strip embedded micro-grid-connected inverter

Abstract

This invention discloses a strip-shaped embedded micro grid-connected inverter at the edge of a photovoltaic panel, comprising a matching strip-shaped housing and internal circuitry. The strip-shaped housing is embedded within the metal frame of a single photovoltaic panel. The internal circuitry sequentially includes a PV-end filter, an isolated non-resonant high-frequency boost DC-DC converter, a full-bridge inverter, and a grid-connected filter. It employs a non-resonant linear soft-switching topology, configured to enable all internal switches to achieve non-resonant zero-current soft-conduction and all diodes to achieve non-resonant zero-current soft-turn-off. This invention discloses a strip-shaped embedded micro grid-connected inverter at the edge of a photovoltaic panel, achieving deep integration with the photovoltaic panel frame through a strip-shaped structure design and utilizing the linear variation characteristic of transformer leakage inductance current to achieve non-resonant linear soft-switching across the entire power range.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic power generation and power electronic conversion technology, specifically relating to a strip-embedded micro grid-connected inverter on the edge of a photovoltaic panel. Background Technology

[0002] With the popularization of distributed photovoltaic systems, microinverters have been widely used due to their advantages such as module-level maximum power point tracking (MPPT), elimination of shading effects, and high system security. However, most existing microinverters are independent cabinet structures installed on the back of photovoltaic modules, which not only increases the overall thickness of the system, making transportation and installation difficult, but also limits the heat dissipation environment.

[0003] In terms of circuit topology, microinverters typically need to boost low-voltage DC to high-voltage AC and convert it to AC. While traditional resonant soft-switching schemes (such as LLC) can reduce losses, their sinusoidal oscillation characteristics lead to severe current stress and sensitivity to parameter fluctuations. Non-resonant hard-switching circuits, on the other hand, suffer from significant switching losses and electromagnetic interference (EMI) problems. Furthermore, achieving high-efficiency, low-heat power conversion within a very small strip space is a core technological challenge in integrating the inverter with the photovoltaic panel frame.

[0004] Therefore, developing a micro-inverter that can be embedded in the frame of a photovoltaic panel to save space, and can improve efficiency and reduce stress through non-resonant linear soft-switching technology, has important clinical engineering value. Summary of the Invention

[0005] The main objective of this invention is to provide a strip-shaped embedded micro grid-connected inverter for photovoltaic panels. Through the strip structure design, it achieves deep integration with the photovoltaic panel frame and utilizes the linear variation characteristic of transformer leakage inductance current to achieve non-resonant linear soft switching across the entire power range.

[0006] To achieve the above objectives, the present invention provides a strip-shaped embedded micro grid-connected inverter for the edge of a photovoltaic panel, comprising a matching strip-shaped housing and internal circuitry. The strip-shaped housing is embedded within the metal frame of a single photovoltaic panel, and the internal circuitry comprises, in sequence, a PV-end filter, an isolated non-resonant high-frequency boost DC-DC converter, a full-bridge inverter, and a grid-connected filter. The isolated non-resonant high-frequency boost DC-DC converter includes an MPPT boost circuit module, an isolation transformer, and an isolation rectifier module. The isolated non-resonant high-frequency boost DC-DC converter adopts a non-resonant linear soft-switching topology, configured to enable all internal switching transistors to achieve non-resonant zero-current soft-conduction and all diodes to achieve non-resonant zero-current soft-turn-off.

[0007] As a further preferred embodiment of the above technical solution, the MPPT boost circuit module includes a first inductor. L 1. Second inductor L 2. First switching transistor S L1 Second switching transistor S L2 First Inductor L One end of 1 and the second inductor L One end of each of the two transistors is connected to the positive electrode of the photovoltaic source, and the first switching transistor... S L1 The source and the second switch S L2 The source electrodes are all connected to the negative electrode of the photovoltaic source, the first inductor L 1. The other end is connected to the first switching transistor. S L1 The drain of the second inductor is connected to node a. L 2. The other end is connected to the second switching transistor. S L2 The drain is connected to node b; Isolation transformers include leakage inductance L k and transformer T 1. Leakage inductance of primary and secondary windings L k Connect the end with the same name as the original edge to node a, and connect the end with the different name of the original edge to node b; The isolated rectifier module includes a first capacitor. C d First diode D 1. Second diode D 2. First capacitor C d One end is connected to the transformer T One end is a secondary diode with a different name, and the other end is connected to the first diode. D Anode of 1, second diode D The cathode of diode 2 is connected to node g; the second diode D 2's anode junction h and the first diode D 1. Cathode junction d; Isolated non-resonant high-frequency boost DC-DC converter utilizes transformer leakage inductance L k The linear ramp change of the current achieves zero-current soft turn-on by linearly increasing the leakage inductance current from zero when the switching transistor is turned on, and zero-current soft turn-off by linearly decreasing the current to zero when the diode is turned off.

[0008] As a further preferred embodiment of the above technical solution, the full-bridge inverter includes a second capacitor. C b Third switching transistor SH1 Up to the sixth switching transistor S H4 Second capacitor C b Connected between node e and node h; third switch S H1 The drain and the fourth switching transistor S H2 The drains of all three transistors are connected to node e, and the third switching transistor... S H1 The source and the fifth switch S H3 The drain connection and the fourth switching transistor S H2 The source and the sixth switch S H4 The drain connection, the fifth switching transistor S H3 The drain and the sixth switch S H4 The drains of all electrodes are connected to node h; The grid-connected filter is connected to the output of the full-bridge inverter and is used to output high-quality sinusoidal AC power. Nodes c, d, and e are combined into a common node.

[0009] As a further preferred technical solution to the above technical solution, the first switching transistor S L1 With the first switching transistor S L2 Employing a driving signal modulation scheme with the same duty cycle and a 180° phase difference, the isolated non-resonant high-frequency boost DC-DC converter forms five orderly switching operating modes. During the switching process of each mode, leakage inductance... L k It smooths current changes and eliminates voltage / current peaks in traditional resonant circuits.

[0010] As a further preferred technical solution to the above technical solution, the specific operating modes are as follows: First working mode: S L1 Turn off, S L2 Conduction, L The current of 1 is transferred to the leakage inductance. L k , T 1 secondary winding and C d Series, through D Discharge to the inverter output module 2, at this time D 2. The current decreases linearly with the primary current until it reaches zero, thus achieving non-resonant zero-current turn-off; Second operating mode: The switching state is maintained, but D 2 has naturally ended. C b Discharge to the inverter module; Third working mode: S L1 and S L2 All are conducting due to leakage inductance. L k The current cannot change abruptly; its current begins to decrease linearly, making... S L1 The current rises linearly from zero to achieve NRZCS conduction and avoid hard switching losses; Fourth working mode: S L1 Conduction, S L2 Turn off, L 1 Current transfer to L k , T 1 side pass D 1 direction C d Charge, D 1. The current decreases linearly until it reaches zero, thus achieving NRZCS turn-off; Fifth operating mode: The switching state is maintained, but... D 1 has naturally ended. L 2. The current continues to transmit energy to the secondary side through the transformer.

[0011] As a further preferred embodiment of the above technical solution, the length direction of the strip-shaped shell extends along the length direction of the metal frame of the photovoltaic panel, and the cross-sectional outline of the strip-shaped shell is adapted to the inner wall of the metal frame of the photovoltaic panel. The strip-shaped housing is fixedly connected to the metal frame of the photovoltaic panel by thermally conductive adhesive or fasteners, and the metal frame is used as a heat sink for auxiliary heat dissipation.

[0012] As a further preferred technical solution of the above technical solution, the input end of the PV end filter is electrically connected to the junction box or busbar of the photovoltaic panel through a wire embedded in the metal frame of the photovoltaic panel, and the output end of the grid-connected filter is led out to the outside of the metal frame.

[0013] As a further preferred embodiment of the above technical solution, the MPPT boost circuit module includes interleaved parallel boost branches, and the full-bridge inverter is controlled by an SPWM signal to output a sinusoidal current.

[0014] The beneficial effects of this invention are: 1. High integration and space utilization: The strip-shaped shell is compatible with the metal frame of the photovoltaic panel, and the inverter is embedded in the frame, which does not occupy additional installation space for the photovoltaic panel and protects the inverter from sun and rain, extending the service life of the device; the flexible flat wires of the PV end filter are hidden in the frame, realizing the integrated design of the photovoltaic panel and the inverter, simplifying the photovoltaic system installation process.

[0015] 2. Excellent heat dissipation performance: The strip-shaped outer shell of the thermally conductive profile is in close contact with the metal frame of the photovoltaic panel. The large-area metal frame is used as a natural heat sink, which solves the heat dissipation problem of high power density components in the compact strip space and ensures the long-term stable operation of the inverter.

[0016] 3. Low loss and high conversion efficiency: Non-resonant linear soft switching is achieved across the entire power range through transformer leakage inductance. The current of both the switching transistor and the diode changes linearly with a ramp, without resonance spikes, which greatly reduces switching losses and electromagnetic interference (EMI). The thermal stress of the power devices is significantly reduced, and combined with natural heat dissipation from the frame, the inverter has high power conversion efficiency.

[0017] 4. Low electrical stress and high reliability: During the switching of various operating modes, leakage inductance... L k Smoothing current changes eliminates voltage / current peaks in traditional resonant circuits and reduces electrical stress on power devices; at the same time, it avoids transient thermal stress from hard switching, improving the inverter's operational reliability and lifespan.

[0018] 5. Excellent grid compatibility: The MPPT boost circuit module enables module-level MPPT control, eliminating the impact of shading on photovoltaic power generation; the grid-connected filter outputs high-quality sinusoidal AC power, meeting grid connection standards, and the inverter can achieve single-panel AC output for a single photovoltaic panel, adapting to the networking requirements of distributed photovoltaic systems. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the physical structure, installation method, and main electrical units of a photovoltaic panel edge-embedded micro grid-connected inverter provided in this embodiment.

[0020] Figure 2 This embodiment shows the topology of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0021] Figure 3 This embodiment presents the modulation timing and key theoretical waveform diagrams of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter circuit in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0022] Figure 4 This embodiment provides a schematic diagram of the first operating mode of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0023] Figure 5 This embodiment provides a schematic diagram of the second operating mode of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0024] Figure 6 This embodiment provides a schematic diagram of the isolated non-resonant high-frequency boost DC-DC converter and the third working mode of the full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0025] Figure 7 This embodiment provides a schematic diagram of the fourth operating mode of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0026] Figure 8 This embodiment provides a schematic diagram of the fifth operating mode of an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter.

[0027] Figure 9 This embodiment provides the first switching transistor in an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter within a photovoltaic panel edge-embedded miniature grid-connected inverter. S L1 Second switching transistor S L2 Simulation waveform of the driving signal.

[0028] Figure 10 This embodiment provides the first switching transistor in an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter within a photovoltaic panel edge-embedded miniature grid-connected inverter. S L1 Second switching transistor S L2 The simulated waveform of the drain-source current.

[0029] Figure 11 This embodiment provides an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-mounted strip-embedded micro grid-connected inverter, specifically the first diode within them. D 1 and second diodes D Current simulation waveform diagram of 2.

[0030] Figure 12This embodiment provides an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded miniature grid-connected inverter, which includes leakage inductance. L k and the first capacitor C d The current simulation waveform diagram.

[0031] Figure 13 This embodiment provides the first switching transistor in an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter within a photovoltaic panel edge-embedded miniature grid-connected inverter. S L1 Second switching transistor S L2 The voltage and current simulation waveforms.

[0032] Figure 14 This embodiment provides an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-mounted strip-embedded micro grid-connected inverter, specifically the first diode within them. D 1 and second diodes D Voltage and current simulation waveforms for 2.

[0033] Figure 15 This embodiment provides an isolated non-resonant high-frequency boost DC-DC converter and a full-bridge inverter in a photovoltaic panel edge-embedded micro grid-connected inverter, with output voltage... V o and input voltage V pv The simulation waveform diagram. Detailed Implementation

[0034] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0035] In a preferred embodiment of the present invention, those skilled in the art should note that the metal frame of the photovoltaic panel involved in the present invention can be regarded as prior art.

[0036] Preferred embodiment.

[0037] like Figure 1-15 As shown, this invention discloses a strip-embedded micro grid-connected inverter on the edge of a photovoltaic panel, such as... Figure 1 As shown, it includes a matching strip-shaped housing and internal circuitry, the strip-shaped housing being embedded within the metal frame of a single photovoltaic panel, as... Figure 2 As shown, the internal circuitry includes, in sequence, a PV-terminal filter, an isolated non-resonant high-frequency boost DC-DC converter, a full-bridge inverter, and a grid-connected filter. The isolated non-resonant high-frequency boost DC-DC converter includes an MPPT boost circuit module, an isolation transformer, and an isolation rectifier module. The isolated non-resonant high-frequency boost DC-DC converter adopts a non-resonant linear soft-switching topology, configured to enable all internal switching transistors to achieve non-resonant zero-current soft-conduction and all diodes to achieve non-resonant zero-current soft-turn-off.

[0038] Specifically, the MPPT boost circuit module includes a first inductor. L 1. Second inductor L 2. First switching transistor S L1 Second switching transistor S L2 First Inductor L One end of 1 and the second inductor L One end of each of the two transistors is connected to the positive electrode of the photovoltaic source, and the first switching transistor... S L1 The source and the second switch S L2 The source electrodes are all connected to the negative electrode of the photovoltaic source, the first inductor L 1. The other end is connected to the first switching transistor. S L1 The drain of the second inductor is connected to node a. L 2. The other end is connected to the second switching transistor. S L2 The drain is connected to node b; Isolation transformers include leakage inductance L k and transformer T 1. Leakage inductance of primary and secondary windings L k Connect the end with the same name as the original edge to node a, and connect the end with the different name of the original edge to node b; The isolated rectifier module includes a first capacitor. C d First diode D 1. Second diode D 2. First capacitor C d One end is connected to the transformer T One end of the secondary side is at the opposite end (node ​​f), and the other end is connected to the first diode. D Anode of 1, second diode D The cathode of diode 2 is connected to node g; the second diode D 2's anode junction h and the first diode D 1. Cathode junction d; Isolated non-resonant high-frequency boost DC-DC converter utilizes transformer leakage inductance L k The linear ramp change of the current (rather than sinusoidal resonance) achieves zero-current soft turn-on (ZCS) by linearly increasing the leakage inductance current from zero when the switch is turned on and zero-current soft turn-off (ZCS) by linearly decreasing the current to zero when the diode is turned off.

[0039] More specifically, the full-bridge inverter includes a second capacitor. C b Third switching transistor S H1 Up to the sixth switching transistor S H4 Second capacitor C b Connected between node e and node h; third switch S H1 The drain and the fourth switching transistor S H2 The drains of all three transistors are connected to node e, and the third switching transistor... S H1 The source and the fifth switch S H3 The drain connection and the fourth switching transistor S H2 The source and the sixth switch S H4 The drain connection, the fifth switching transistor S H3 The drain and the sixth switch S H4 The drains of all electrodes are connected to node h; The grid-connected filter is connected to the output of the full-bridge inverter to output high-quality sinusoidal AC power, at node c ( T 1. The same-named ends of the secondary edge), node d and node e are combined into a common node.

[0040] Furthermore, the first switching transistor S L1 With the first switching transistor S L2 Using a driving signal modulation method with the same duty cycle and a phase difference of 180°, such as... Figure 3 As shown, based on this modulation method, the isolated non-resonant high-frequency boost DC-DC converter forms five orderly switching operating modes. During the switching process of each mode, the leakage inductance... L k It smooths current changes and eliminates voltage / current peaks in traditional resonant circuits.

[0041] Furthermore, the specific working modes are as follows: like Figure 4As shown, the first working mode: S L1 Turn off, S L2 Conduction, L The current of 1 is transferred to the leakage inductance. L k , T 1 secondary winding and C d Series, through D Discharge of the two inverter output modules (full-bridge inverter) at this time. D 2. The current decreases linearly with the primary current until it reaches zero, thus achieving non-resonant zero-current (NRZCS) turn-off; like Figure 5 As shown, the second operating mode: the switching state is maintained, but... D 2 has naturally ended. C b Discharge to the inverter module (full-bridge inverter and grid-connected filter); like Figure 6 As shown, the third working mode: S L1 and S L2 All are conducting due to leakage inductance. L k The current cannot change abruptly; its current begins to decrease linearly, making... S L1 The current rises linearly from zero, enabling NRZCS (non-resonant zero-current switch) to be turned on, thus avoiding hard switching losses. like Figure 7 As shown, the fourth working mode: S L1 Conduction, S L2 Turn off, L 1 Current transfer to L k , T 1 side pass D 1 direction C d Charge, D 1. The current decreases linearly until it reaches zero, thus achieving NRZCS turn-off; like Figure 8 As shown, the fifth operating mode: the switching state is maintained, but... D 1 has naturally ended. L 2. The current continues to transmit energy to the secondary side through the transformer.

[0042] Preferably, the length direction of the strip-shaped shell extends along the length direction of the metal frame of the photovoltaic panel, and the cross-sectional outline of the strip-shaped shell is adapted to the inner wall of the metal frame of the photovoltaic panel (its cross-sectional dimensions are adapted to the inner profile groove of the metal frame of the standard photovoltaic panel, thus forming an AC output photovoltaic module). The strip-shaped shell is fixedly connected to the metal frame of the photovoltaic panel by thermally conductive adhesive or fasteners. The metal frame is used as a heat sink for auxiliary heat dissipation. The strip-shaped shell is made of thermally conductive profile, and its outer surface is in close contact with the metal frame of the photovoltaic panel, using the large area of ​​the metal frame as a natural heat sink.

[0043] Preferably, the input end of the PV-end filter is electrically connected to the junction box or busbar of the photovoltaic panel through a wire embedded in the metal frame of the photovoltaic panel (high integration), and the output end of the grid-connected filter is led out to the outside of the metal frame.

[0044] Preferably, the MPPT boost circuit module includes interleaved parallel boost branches, and the full-bridge inverter is controlled by an SPWM signal to output a sinusoidal current.

[0045] To verify the performance of the photovoltaic panel edge-embedded micro grid-connected inverter described in this invention in actual operation, especially the linear soft-switching characteristics of its isolated non-resonant high-frequency boost DC-DC converter section, a simulation platform was built for verification in this embodiment. The key circuit parameters used in the simulation are shown in Table 1.

[0046] Table 1 like Figure 9 As shown, this is the first switching transistor in the present invention. S L1 Second switching transistor S L2 The simulation waveform of the drive control signal is shown in the figure. As can be seen from the figure, the duty cycles of the two control signals are the same and the phase difference is 180°. This interleaved parallel drive method helps to reduce the ripple of the input current in the strip structure and reduce the size requirements of the front-stage PV end filter.

[0047] Under the above driving sequence, the non-resonant linear soft-switching characteristics of the core circuit of this invention are demonstrated as follows: Verification of the NRZCS conduction of the switching transistor: as follows... Figure 10 As shown, this is the first switching transistor. S L1 Second switching transistor S L2 The current simulation waveform shows that the switching current rises linearly from zero at the moment of conduction, without any resonant spikes, achieving non-resonant zero-current (NRZCS) turn-on, which effectively reduces the turn-on loss and transient thermal stress of the switching transistor.

[0048] Diode NRZCS turn-off verification: such as Figure 11 As shown in the simulation waveform of the diode current in the isolation rectifier module, the current exhibits a clear linear change characteristic as it drops to zero, achieving natural turn-off of NRZCS. This solves the reverse recovery interference problem caused by high-frequency commutation in a compact strip space.

[0049] Physical mechanism demonstration: To further prove that the NRZCS characteristic is realized by the linear change of leakage inductance under the node KCL constraint, Figure 12 Provides leakage sensing L k and the first capacitor C d The simulated current waveform is shown in the figure. As can be seen from the figure, the leakage inductance... L k With capacitor C d The current change trends are highly consistent, and all exhibit linear slope characteristics as the current drops to zero. Figure 13-14 The voltage and current overlap between the switching transistor and the diode was further comprehensively demonstrated, clearly proving the zero-current characteristic across the entire operating domain. Finally, system-level verification was conducted to demonstrate the functionality of this invention as an AC output module for a single photovoltaic panel. Figure 15 As shown, the simulation waveforms demonstrate the complete process by which the system achieves high-gain boost from a 30V low-voltage DC input (simulating the output of a single photovoltaic panel) to a 400V high-voltage DC bus, and finally transforms it into a 220V standard sinusoidal AC current.

[0050] Experimental Conclusions: The simulation results above demonstrate that the inverter described in this invention not only achieves high-gain and high-efficiency conversion (effectively suppressing switching losses and EMI) through non-resonant linear soft-switching technology in electrical engineering, but also verifies its feasibility of operation under limited heat dissipation conditions through a strip-embedded design in physical structure. This proves that this invention can perfectly meet the stringent requirements of distributed photovoltaic systems for high power density, long lifespan, and integrated operation.

[0051] It is worth mentioning that the technical features of the photovoltaic panel, such as the metal frame, involved in this patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0052] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A strip-embedded micro grid-connected inverter with a photovoltaic panel edge, characterized in that, It includes a matching strip-shaped housing and internal circuitry. The strip-shaped housing is embedded in the metal frame of a single photovoltaic panel. The internal circuitry includes, in sequence, a PV-end filter, an isolated non-resonant high-frequency boost DC-DC converter, a full-bridge inverter, and a grid-connected filter. The isolated non-resonant high-frequency boost DC-DC converter includes an MPPT boost circuit module, an isolation transformer, and an isolation rectifier module. The isolated non-resonant high-frequency boost DC-DC converter adopts a non-resonant linear soft-switching topology, configured to enable all internal switching transistors to achieve non-resonant zero-current soft-conduction and all diodes to achieve non-resonant zero-current soft-turn-off.

2. The photovoltaic panel edge-embedded micro grid-connected inverter according to claim 1, characterized in that, The MPPT boost circuit module includes a first inductor. L 1. Second inductor L 2. First switching transistor S L1 Second switching transistor S L2 First Inductor L One end of 1 and the second inductor L One end of each of the two transistors is connected to the positive electrode of the photovoltaic source, and the first switching transistor... S L1 The source and the second switch S L2 The source electrodes are all connected to the negative electrode of the photovoltaic source, the first inductor L 1. The other end is connected to the first switching transistor. S L1 The drain of the second inductor is connected to node a. L 2. The other end is connected to the second switching transistor. S L2 The drain is connected to node b; Isolation transformers include leakage inductance L k and transformer T 1. Leakage inductance of primary and secondary windings L k Connect the end with the same name as the original edge to node a, and connect the end with the different name of the original edge to node b; The isolated rectifier module includes a first capacitor. C d First diode D 1. Second diode D 2. First capacitor C d One end is connected to the transformer T One end is a secondary diode with a different name, and the other end is connected to the first diode. D Anode of 1, second diode D The cathode of diode 2 is connected to node g; the second diode D 2's anode junction h and the first diode D 1. Cathode junction d; Isolated non-resonant high-frequency boost DC-DC converter utilizes transformer leakage inductance L k The linear ramp change of the current achieves zero-current soft turn-on by linearly increasing the leakage inductance current from zero when the switching transistor is turned on, and zero-current soft turn-off by linearly decreasing the current to zero when the diode is turned off.

3. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 2, characterized in that, The full-bridge inverter includes a second capacitor. C b Third switching transistor S H1 Up to the sixth switching transistor S H4 Second capacitor C b Connected between node e and node h; third switch S H1 The drain and the fourth switching transistor S H2 The drains of all three transistors are connected to node e, and the third switching transistor... S H1 The source and the fifth switch S H3 The drain connection and the fourth switching transistor S H2 The source and the sixth switch S H4 The drain connection, the fifth switching transistor S H3 The drain and the sixth switch S H4 The drains of all electrodes are connected to node h; The grid-connected filter is connected to the output of the full-bridge inverter and is used to output high-quality sinusoidal AC power. Nodes c, d, and e are combined into a common node.

4. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 3, characterized in that, The first switching transistor S L1 With the first switching transistor S L2 Employing a driving signal modulation scheme with the same duty cycle and a 180° phase difference, the isolated non-resonant high-frequency boost DC-DC converter forms five orderly switching operating modes. During the switching process of each mode, leakage inductance... L k It smooths current changes and eliminates voltage / current peaks in traditional resonant circuits.

5. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 4, characterized in that, The specific working modes are as follows: First working mode: S L1 Turn off, S L2 Conduction, L The current of 1 is transferred to the leakage inductance. L k , T 1 secondary winding and C d Series, through D Discharge to the inverter output module 2, at this time D 2. The current decreases linearly with the primary current until it reaches zero, thus achieving non-resonant zero-current turn-off; Second operating mode: The switching state is maintained, but D 2 has naturally ended. C b Discharge to the inverter module; Third working mode: S L1 and S L2 All are conducting due to leakage inductance. L k The current cannot change abruptly; its current begins to decrease linearly, making... S L1 The current rises linearly from zero to achieve NRZCS conduction and avoid hard switching losses; Fourth working mode: S L1 Conduction, S L2 Turn off, L 1 Current transfer to L k , T 1 side pass D 1 direction C d Charge, D 1. The current decreases linearly until it reaches zero, thus achieving NRZCS turn-off; Fifth operating mode: The switching state is maintained, but... D 1 has naturally ended. L 2. The current continues to transmit energy to the secondary side through the transformer.

6. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 1, characterized in that, The length of the strip-shaped shell extends along the length of the metal frame of the photovoltaic panel, and the cross-sectional outline of the strip-shaped shell is adapted to the inner wall of the metal frame of the photovoltaic panel. The strip-shaped housing is fixedly connected to the metal frame of the photovoltaic panel by thermally conductive adhesive or fasteners, and the metal frame is used as a heat sink for auxiliary heat dissipation.

7. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 1, characterized in that, The input end of the PV-end filter is electrically connected to the junction box or busbar of the photovoltaic panel through a wire embedded in the metal frame of the photovoltaic panel, and the output end of the grid-connected filter is led out to the outside of the metal frame.

8. A photovoltaic panel edge-embedded micro grid-connected inverter according to claim 1, characterized in that, The MPPT boost circuit module includes interleaved parallel boost branches, and the full-bridge inverter is controlled by an SPWM signal to output a sinusoidal current.

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