Double-half-wave high-frequency chained micro inverter and photovoltaic power generation system

Abstract

The utility model discloses a double-half-wave high-frequency chained micro inverter and a photovoltaic power generation system. The double-half-wave high-frequency chain type miniature inverter comprises a double-winding high-frequency transformer, a first half-wave type cycloconverter and a second half-wave type cycloconverter. The primary side of the double-winding high-frequency transformer is connected with the high-frequency inverter circuit, and the high-frequency inverter circuit is used for loading a generated signal waveform on the primary side of the double-winding high-frequency transformer; when the secondary side of the double-winding high-frequency transformer outputs a positive half wave, the first half-wave cycloconverter is used for transmitting the energy of the positive half wave to the output side; and when the secondary side of the double-winding high-frequency transformer outputs a negative half wave, the second half-wave cycloconverter is used for transmitting the energy of the negative half wave to the output side. According to the utility model, the efficiency of the inverter can be improved, and the output voltage is the voltage with completely equal amplitude.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation, in particular to a double half-wave high-frequency chain-type micro-inverter and a photovoltaic power generation system. Background Art

[0002] Figure 1 This is a circuit topology diagram of a traditional single-stage high-frequency chain inverter. Figure 1 ,In the traditional single-stage high-frequency link inverter, the principle of achieving output voltage ,phase balance is to separate the secondary transformer winding from the middle tap to ,achieve the magnetic balance of the transformer. Figure 2 It is an equivalent circuit diagram of a secondary side cycloconverter in the positive half-power frequency cycle. Figure 3 This is another equivalent circuit diagram of a secondary side cycloconverter in the positive half-power frequency cycle. Figure 2 and Figure 3 , the B phase load is open circuit. According to the working mode analysis, v an and v bn can be regarded as two high-frequency square wave voltage sources. Since the two secondary windings of the high-frequency transformer have the same number of turns, v an and v bn The amplitude is also the same, that is, v an =|v bn |≈nv in In addition, since the switching frequency is very large compared to the power frequency, v an and v bn The duty cycle of can be considered to be roughly equal. Therefore, v an and v bn The average value within a switching cycle can be considered the same. 1 ~Q 4 and Q 5 ~Q 8 The same modulation wave is used for modulation, so v an and v bn It can also be considered balanced within the power frequency cycle. Therefore, even if the load condition is extremely unbalanced, the output voltage can remain automatically balanced. At this time, v o1 =v o2 =0.5v o Alternatively, separate dual windings can be used to achieve the same purpose.

[0003] However, although this strategy achieves two voltage outputs with equal amplitudes and opposite phases, it has the following disadvantages: If the primary-secondary ratio is 1:n:n, the secondary side of the transformer needs to be wound 2n times as many turns as the primary side, and the corresponding core volume and core loss, transformer winding loss, parasitic parameters, and overall transformer volume will increase, and reduce inverter efficiency. If the number of turns of the two windings on the secondary side is not completely equal, the output voltage cannot be phased into voltages with completely equal amplitudes. Utility Model Content

[0004] The utility model provides a double half-wave high-frequency chain-type micro-inverter and a photovoltaic power generation system, which can improve the efficiency of the inverter, and the output voltage is a voltage with completely equal amplitude.

[0005] According to one aspect of the utility model, a double half-wave high-frequency chain-type micro-inverter is provided, and the double half-wave high-frequency chain-type micro-inverter comprises: a double-winding high-frequency transformer, a first half-wave type cycloconverter, and a second half-wave type cycloconverter;

[0006] The primary side of the dual-winding high-frequency transformer is connected to a high-frequency inverter circuit, and the high-frequency inverter circuit is used to load the generated signal waveform onto the primary side of the dual-winding high-frequency transformer;

[0007] The first end of the first half-wave cycloconverter is connected to the first end of the second half-wave cycloconverter and the first end of the secondary side of the dual-winding high-frequency transformer, and the second end of the first half-wave cycloconverter is connected to the second end of the second half-wave cycloconverter and the second end of the secondary side of the dual-winding high-frequency transformer;

[0008] When the secondary side of the dual-winding high-frequency transformer outputs a positive half-wave, the first half-wave type cycloconverter is used to transfer the energy of the positive half-wave to the output side; when the secondary side of the dual-winding high-frequency transformer outputs a negative half-wave, the second half-wave type cycloconverter is used to transfer the energy of the negative half-wave to the output side.

[0009] Optionally, the first half-wave cycloconverter and the second half-wave cycloconverter share the same terminal and use the same neutral line to form a parallel structure.

[0010] Optionally, the number of turns of the primary winding of the dual-winding high-frequency transformer is the same as the number of turns of the secondary winding of the dual-winding high-frequency transformer.

[0011] Optionally, the first half-wave cycloconverter comprises: a first switch unit and a first filter unit;

[0012] The first end of the first switch unit is connected to the first end of the secondary side of the dual-winding high-frequency transformer, the third end of the first switch unit is connected to the second end of the secondary side of the dual-winding high-frequency transformer, and the first filter unit is connected between the second end of the first switch unit and the third end of the first switch unit.

[0013] Optionally, the first switch unit includes: a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the first filter unit includes: a first inductor and a first capacitor;

[0014] The first end of the secondary side of the dual-winding high-frequency transformer is connected to the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the second end of the secondary side of the dual-winding high-frequency transformer in sequence, the first end of the first inductor is connected to the third switch tube, the second end of the first inductor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the fourth switch tube.

[0015] Optionally, the second half-wave cycloconverter comprises: a second switch unit and a second filter unit;

[0016] The first end of the second switch unit is connected to the first end of the secondary side of the dual-winding high-frequency transformer, the third end of the second switch unit is connected to the second end of the secondary side of the dual-winding high-frequency transformer, and the second filter unit is connected between the second end of the second switch unit and the third end of the second switch unit.

[0017] Optionally, the second switch unit includes: a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the second filter unit includes: a second inductor and a second capacitor;

[0018] The first end of the secondary side of the dual-winding high-frequency transformer is connected to the fifth switch tube, the sixth switch tube, the eighth switch tube, the seventh switch tube and the second end of the secondary side of the dual-winding high-frequency transformer in sequence, the first end of the second inductor is connected to the eighth switch tube, the second end of the second inductor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the seventh switch tube.

[0019] Optionally, the high-frequency inverter circuit includes: a photovoltaic module, a filter unit and a switch unit;

[0020] The first end of the photovoltaic component is connected to the first end of the filter unit and the first end of the switch unit, the second end of the photovoltaic component is connected to the second end of the filter unit and the second end of the switch unit, and the primary side of the dual-winding high-frequency transformer is connected between the third end of the switch unit and the fourth end of the switch unit.

[0021] Optionally, the filtering unit includes a filtering capacitor, and the switching unit includes an eleventh switching tube, a twelfth switching tube, a thirteenth switching tube, and a fourteenth switching tube;

[0022] The first end of the photovoltaic component is connected to the first end of the filter capacitor, the first end of the eleventh switch tube, and the first end of the twelfth switch tube. The second end of the photovoltaic component is connected to the second end of the filter capacitor, the second end of the thirteenth switch tube, and the second end of the fourteenth switch tube. The first end of the thirteenth switch tube is connected to the second end of the eleventh switch tube and the first end of the primary side of the dual-winding high-frequency transformer. The first end of the fourteenth switch tube is connected to the second end of the twelfth switch tube and the second end of the primary side of the dual-winding high-frequency transformer.

[0023] According to another aspect of the utility model, a photovoltaic power generation system is provided, which includes the double half-wave high-frequency chain micro-inverter described in any one of the above aspects.

[0024] The technical solution of the utility model proposes a double half-wave high-frequency chain micro-inverter with double frequency decoupling capability. The inputs of the first half-wave type cycloconverter and the second half-wave type cycloconverter share the same-name end of the secondary side of the double-winding high-frequency transformer. The first half-wave type cycloconverter and the second half-wave type cycloconverter share the lower end of the double-winding high-frequency transformer as the neutral line to form a parallel structure. The double half-wave cycloconverter uses the positive and negative half-waves of the secondary side of the transformer for phase-splitting output respectively, and the two-phase output voltage can achieve automatic balance, thereby realizing energy transfer. Compared with the existing transformer, the double half-wave high-frequency chain micro-inverter in the utility model uses a double-winding high-frequency transformer, cancels the transformer connected to the lower half-wave type converter, and the output voltage phase is a voltage with completely equal amplitude; the number of turns required for the secondary side of the transformer is n times that of the primary side, and the corresponding magnetic core volume and magnetic core loss, transformer winding loss, parasitic parameters, and the overall volume of the transformer are reduced, and the inverter efficiency is improved. In summary, the utility model solves the problem that the number of turns required for the secondary side of the existing transformer is 2n times that of the primary side, the corresponding core volume and core loss, transformer winding loss, parasitic parameters, and the overall volume of the transformer will increase, and the inverter efficiency is low. It can also solve the problem that the output voltage of the transformer cannot be phased into voltages with completely equal amplitudes.

[0025] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the utility model, nor is it intended to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 It is a circuit topology diagram of a traditional single-stage high-frequency chain inverter;

[0028] Figure 2 It is an equivalent circuit diagram of a secondary side cycloconverter in the positive half power frequency cycle;

[0029] Figure 3 It is another equivalent circuit diagram of a secondary side cycloconverter in the positive half power frequency cycle;

[0030] Figure 4 It is a structural schematic diagram of a double half-wave high-frequency chain-link micro-inverter provided according to an embodiment of the utility model;

[0031] Figure 5 It is a waveform diagram of a secondary side modulation strategy switch of a transformer provided according to an embodiment of the utility model;

[0032] Figure 6 It is a circuit principle diagram of a double half-wave high-frequency chain-link micro-inverter provided according to an embodiment of the utility model;

[0033] Figure 7 It is a circuit principle diagram of another double half-wave high-frequency chain-link micro-inverter provided according to an embodiment of the utility model;

[0034] Figure 8 It is a curve diagram of a photovoltaic characteristic provided according to an embodiment of the utility model;

[0035] Fig. 9 It is a schematic diagram of simulation results after improving the transformer structure according to an embodiment of the utility model. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Figure 4 is a schematic diagram of a double half-wave high frequency chain micro inverter according to an embodiment of the utility model, referring to Figure 4 The embodiment of the utility model provides a double half-wave high-frequency chain micro-inverter, which includes: a double-winding high-frequency transformer 10, a first half-wave cycloconverter 20 and a second half-wave cycloconverter 30; the primary side of the double-winding high-frequency transformer 10 is connected to the high-frequency inverter circuit, and the high-frequency inverter circuit is used to load the generated signal waveform on the primary side of the double-winding high-frequency transformer 10; the first end of the first half-wave cycloconverter 20 and the first end of the second half-wave cycloconverter 30 are connected to each other. The first end of the secondary side of the dual-winding high-frequency transformer 10 is connected, and the second end of the first half-wave type cycloconverter 20 is connected to the second end of the second half-wave type cycloconverter 30 and the second end of the secondary side of the dual-winding high-frequency transformer 10; when the secondary side of the dual-winding high-frequency transformer 10 outputs a positive half-wave, the first half-wave type cycloconverter 20 is used to transfer the energy of the positive half-wave to the output side; when the secondary side of the dual-winding high-frequency transformer 10 outputs a negative half-wave, the second half-wave type cycloconverter 30 is used to transfer the energy of the negative half-wave to the output side.

[0039] Specifically, Figure 5 is a waveform diagram of a secondary side modulation strategy switch of a transformer provided according to an embodiment of the utility model, with reference to Figure 5 The cycloconverter connected to the secondary side of the transformer is composed of two half-wave cycloconverters. Figure 5 The secondary modulation strategy shown in the figure shows that the upper and lower half-waves of the high-frequency square wave voltage output by the secondary side of the transformer are used by the upper and lower half-wave cycloconverters respectively. Under the transformer secondary modulation strategy, the modulation strategies of the switch tubes Q6 and Q2 are also exchanged at the same time after the positive and negative half-waves of the modulation wave are exchanged, that is, v ab Using v s1 is positive and v s2 The voltage output is negative.

[0040] Therefore, only a double-winding high-frequency transformer can be used, and the transformer connected to the lower half-wave converter can be eliminated. The double-winding high-frequency transformer can be used in all topologies using double half-wave cycloconverters. The first half-wave cycloconverter 20 can be an upper half-wave cycloconverter, and the second half-wave cycloconverter 30 can be a lower half-wave cycloconverter. The two half-wave cycloconverters share the same end and use the same neutral line to form a parallel structure, which can also obtain the same effect as the three-winding transformer. Compared with the traditional three-winding transformer, it has a smaller volume, fewer turns and lower loss. That is, when the secondary side of the double-winding high-frequency transformer 10 outputs a positive half-wave, it is output by the first half-wave cycloconverter 20; when the secondary side of the double-winding high-frequency transformer 10 outputs a negative half-wave, it is output by the second half-wave cycloconverter 30. The output ends of the first half-wave cycloconverter 20 and the second half-wave cycloconverter 30 can be loaded separately or jointly, and the output voltage can be naturally balanced; the output ends of the first half-wave cycloconverter 20 and the second half-wave cycloconverter 30 can also be connected to the power grid.

[0041] The technical solution of the utility model proposes a double half-wave high-frequency chain micro-inverter with double frequency decoupling capability. The inputs of the first half-wave type cycloconverter and the second half-wave type cycloconverter share the same-name end of the secondary side of the double-winding high-frequency transformer. The first half-wave type cycloconverter and the second half-wave type cycloconverter share the lower end of the double-winding high-frequency transformer as the neutral line to form a parallel structure. The double half-wave cycloconverter uses the positive and negative half-waves of the secondary side of the transformer for phase-splitting output respectively, and the two-phase output voltage can achieve automatic balance, thereby realizing energy transfer. Compared with the existing transformer, the double half-wave high-frequency chain micro-inverter in the utility model uses a double-winding high-frequency transformer, cancels the transformer connected to the lower half-wave type converter, and the output voltage phase is a voltage with completely equal amplitude; the number of turns required for the secondary side of the transformer is n times that of the primary side, and the corresponding magnetic core volume and magnetic core loss, transformer winding loss, parasitic parameters, and the overall volume of the transformer are reduced, and the inverter efficiency is improved. In summary, the utility model solves the problem that the number of turns required for the secondary side of the existing transformer is 2n times that of the primary side, the corresponding core volume and core loss, transformer winding loss, parasitic parameters, and the overall volume of the transformer will increase, and the inverter efficiency is low. It can also solve the problem that the output voltage of the transformer cannot be phased into voltages with completely equal amplitudes.

[0042] Continue to refer Figure 4 Optionally, the first half-wave cycloconverter 20 and the second half-wave cycloconverter 30 share the same terminal and use the same neutral line to form a parallel structure.

[0043] Specifically, compared with the traditional single-stage high-frequency link inverter, the first half-wave cycloconverter 20 and the second half-wave cycloconverter 30 share the same terminal and use the same neutral line to form a parallel structure, which can achieve the same equivalent effect as the three-winding transformer. It can also provide room for improvement in the selection of transformers, which is conducive to reducing the volume, reducing the core loss, improving the efficiency and energy density, and providing room for improvement in improving efficiency and project establishment. The improved transformer structure can avoid problems such as phase imbalance and bias or electromagnetic coupling caused by the error in the number of turns of the three windings. Selecting the transformer according to this scheme can improve efficiency, volume and energy density.

[0044] Optionally, the number of turns of the primary winding of the double-winding high-frequency transformer is the same as the number of turns of the secondary winding of the double-winding high-frequency transformer.

[0045] Specifically, the primary and secondary windings of the dual-winding high-frequency transformer have the same number of turns, and the secondary output adopts the form of a combination of two half-wave type cycloconverters, so that the energy of the positive and negative half-cycles of the primary high-frequency square wave (it should be noted that in addition to the high-frequency square wave, it can also be an AC waveform such as a triangular wave and a sine wave) can be transmitted to the output side, thereby improving the voltage utilization.

[0046] Figure 6 This is a circuit diagram of a double half-wave high-frequency chain-link micro-inverter provided according to an embodiment of the utility model, referring to Figure 6 Optionally, the first half-wave cycloconverter 20 includes: a first switch unit 21 and a first filter unit 22; the first end of the first switch unit 21 is connected to the first end of the secondary side of the dual-winding high-frequency transformer 10, the third end of the first switch unit 21 is connected to the second end of the secondary side of the dual-winding high-frequency transformer 10, and the first filter unit 22 is connected between the second end of the first switch unit 21 and the third end of the first switch unit 21.

[0047] Continue to refer Figure 6 Optionally, the first switch unit 21 includes: a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4, and the first filter unit 22 includes: a first inductor L f1 And the first capacitor C O1 The first end of the secondary side of the dual-winding high-frequency transformer 10 is connected to the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the second end of the secondary side of the dual-winding high-frequency transformer 10 in sequence, and the first inductor L f1 The first end of the first inductor L is connected to the third switch tube Q3. f1 The second end of the first capacitor C O1 The first end of the first capacitor C O1 The second end of is connected to the fourth switch tube Q4.

[0048] Continue to refer Figure 6 Optionally, the second half-wave cycloconverter 30 includes: a second switch unit 31 and a second filter unit 32; the first end of the second switch unit 31 is connected to the first end of the secondary side of the dual-winding high-frequency transformer 10, the third end of the second switch unit 31 is connected to the second end of the secondary side of the dual-winding high-frequency transformer 10, and the second filter unit 32 is connected between the second end of the second switch unit 31 and the third end of the second switch unit 31.

[0049] Continue to refer Figure 6 Optionally, the second switch unit 31 includes: a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7 and an eighth switch tube Q8, and the second filtering unit 32 includes: a second inductor L f2 And the second capacitor C O2 The first end of the secondary side of the dual-winding high-frequency transformer 10 is connected in sequence to the fifth switch tube Q5, the sixth switch tube Q6, the eighth switch tube Q8, the seventh switch tube Q7 and the second end of the secondary side of the dual-winding high-frequency transformer 10, and the second inductor L f2 The first end of the second inductor L is connected to the eighth switch tube Q8. f2 The second end of the second capacitor C O2 The first end of the second capacitor C O2 The second end is connected to the seventh switch tube Q7.

[0050] Continue to refer Figure 6 Optionally, the high-frequency inverter circuit includes: a photovoltaic component 101, a filter unit 102 and a switch unit 103; the first end of the photovoltaic component 101 is connected to the first end of the filter unit 102 and the first end of the switch unit 103, the second end of the photovoltaic component 101 is connected to the second end of the filter unit 102 and the second end of the switch unit 103, and the primary side of the dual-winding high-frequency transformer 10 is connected between the third end of the switch unit 103 and the fourth end of the switch unit 103.

[0051] Continue to refer Figure 6 Optionally, the filter unit 102 includes a filter capacitor C in The switch unit 103 includes an eleventh switch tube T1, a twelfth switch tube T2, a thirteenth switch tube T3 and a fourteenth switch tube T4; the first end of the photovoltaic component 101 is connected to the filter capacitor C in The first end of the photovoltaic module 101 is connected to the first end of the eleventh switch tube T1 and the first end of the twelfth switch tube T2, and the second end of the photovoltaic module 101 is connected to the filter capacitor C inThe second end of the first switch tube T3 is connected to the second end of the thirteenth switch tube T3 and the second end of the fourteenth switch tube T4, the first end of the thirteenth switch tube T3 is connected to the second end of the eleventh switch tube T1 and the first end of the primary side of the dual-winding high-frequency transformer 10, and the first end of the fourteenth switch tube T4 is connected to the second end of the twelfth switch tube T2 and the second end of the primary side of the dual-winding high-frequency transformer 10.

[0052] Specifically, the connection method of the double-winding high-frequency transformer 10 can achieve the following improvements: providing room for improvement in transformer selection, reducing volume, reducing core loss, and improving efficiency and energy density; providing room for improvement in efficiency. The improved transformer structure can avoid problems such as phase imbalance and bias or electromagnetic coupling caused by the error in the number of turns of the three windings. Selecting a transformer according to this scheme can improve efficiency, volume, and energy density.

[0053] Figure 7 This is a circuit diagram of another double half-wave high-frequency chain-type micro-inverter provided according to an embodiment of the utility model, referring to Figure 7 , Figure 7 The equivalent topology transformation of the double half-wave high-frequency chain-type micro-inverter circuit is shown as an example. Figure 6 compared to, Figure 7 The main method is to change the positions of the first switch tube Q1, the second switch tube Q2, the fifth switch tube Q5, and the sixth switch tube Q6, so that the first switch tube Q1 and the second switch tube Q2 are aligned with the fourth switch tube Q4 and the third switch tube Q3, respectively, and the fifth switch tube Q5 and the sixth switch tube Q6 are aligned with the seventh switch tube Q7 and the eighth switch tube Q8, respectively. The first switch tube Q1 and the second switch tube Q2 connected in series are arranged in parallel with the fourth switch tube Q4 and the third switch tube Q3 connected in series, the fifth switch tube Q5 and the sixth switch tube Q6 connected in series are arranged in parallel with the seventh switch tube Q7 and the eighth switch tube Q8 connected in series, and the positions and connection methods of other components are the same as those of the first switch tube Q1 and the second switch tube Q2 connected in series are arranged in parallel with the fourth switch tube Q4 and the third switch tube Q3 connected in series, and ... Figure 6 It should be noted that the dual-winding high-frequency transformer structure can be used in all topologies using dual half-wave cycloconverters.

[0054] The above control strategy is simulated and verified. At this time, the input capacitor used in the simulation circuit is reduced from 18.8mF used in the previous topology to 100uF, the bus average is 65V, the voltage bus decoupling capacitor is 4000uF, the inductor used in the integrated pre-stage Boost circuit is 280uH, its equivalent series resistance is 0.005Ω, and the high-frequency transformer ratio is 7. Except for special marks, the grid impedance is not considered. The selected photovoltaic parameters are shown in Table 1:

[0055] Table 1 Photovoltaic parameters used in simulation (light 1000W / m 2 , temperature 25℃)

[0056]

[0057] Figure 8 is a schematic diagram of a photovoltaic characteristic curve provided according to an embodiment of the utility model, with reference to Figure 8 , Figure 8 The corresponding photovoltaic characteristic curves are shown.

[0058] Since the extreme unbalanced split-phase load conditions of the two solutions are similar, that is, one phase is not loaded and the other phase is loaded with 200 ohms, the total output is also loaded with 200 ohms. It is necessary to note again that: vo1 = vo2 = 0.5vo. Fig. 9 is a schematic diagram of simulation results after improving the transformer structure according to an embodiment of the utility model, referring to Fig. 9 , Fig. 9 The figure shows the situation where only the output waveform after the improved transformer connection method is displayed.

[0059] The embodiment of the utility model further provides a photovoltaic power generation system, which includes the double half-wave high-frequency chain micro-inverter provided by any embodiment of the utility model.

[0060] Since the photovoltaic power generation system includes the double half-wave high-frequency chain micro-inverter provided by any embodiment of the utility model, the above photovoltaic power generation system has the same beneficial effects as the double half-wave high-frequency chain micro-inverter, which will not be repeated here.

[0061] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A double half-wave high frequency chain micro inverter, characterized in that: include: A double-winding high-frequency transformer, a first half-wave cycloconverter, and a second half-wave cycloconverter; The primary side of the dual-winding high-frequency transformer is connected to a high-frequency inverter circuit, and the high-frequency inverter circuit is used to load the generated signal waveform onto the primary side of the dual-winding high-frequency transformer; The first end of the first half-wave cycloconverter is connected to the first end of the second half-wave cycloconverter and the first end of the secondary side of the dual-winding high-frequency transformer, and the second end of the first half-wave cycloconverter is connected to the second end of the second half-wave cycloconverter and the second end of the secondary side of the dual-winding high-frequency transformer; When the secondary side of the dual-winding high-frequency transformer outputs a positive half-wave, the first half-wave type cycloconverter is used to transfer the energy of the positive half-wave to the output side; when the secondary side of the dual-winding high-frequency transformer outputs a negative half-wave, the second half-wave type cycloconverter is used to transfer the energy of the negative half-wave to the output side.

2. The double half-wave high frequency chain micro inverter according to claim 1, characterized in that: The first half-wave cycloconverter and the second half-wave cycloconverter share the same terminal and use the same neutral line to form a parallel structure.

3. The double half-wave high frequency chain micro inverter according to claim 1, characterized in that: The number of turns of the primary winding of the double-winding high-frequency transformer is the same as the number of turns of the secondary winding of the double-winding high-frequency transformer.

4. The double half-wave high frequency chain micro-inverter according to claim 1, characterized in that: The first half-wave cycloconverter comprises: a first switch unit and a first filter unit; The first end of the first switch unit is connected to the first end of the secondary side of the dual-winding high-frequency transformer, the third end of the first switch unit is connected to the second end of the secondary side of the dual-winding high-frequency transformer, and the first filter unit is connected between the second end of the first switch unit and the third end of the first switch unit.

5. The double half-wave high frequency chain micro inverter according to claim 4, characterized in that: The first switch unit includes: a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the first filter unit includes: a first inductor and a first capacitor; The first end of the secondary side of the dual-winding high-frequency transformer is connected to the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the second end of the secondary side of the dual-winding high-frequency transformer in sequence, the first end of the first inductor is connected to the third switch tube, the second end of the first inductor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the fourth switch tube.

6. The double half-wave high frequency chain micro inverter according to claim 1, characterized in that: The second half-wave cycloconverter comprises: a second switch unit and a second filter unit; The first end of the second switch unit is connected to the first end of the secondary side of the dual-winding high-frequency transformer, the third end of the second switch unit is connected to the second end of the secondary side of the dual-winding high-frequency transformer, and the second filter unit is connected between the second end of the second switch unit and the third end of the second switch unit.

7. The double half-wave high frequency chain micro-inverter according to claim 6, characterized in that: The second switch unit includes: a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the second filter unit includes: a second inductor and a second capacitor; The first end of the secondary side of the dual-winding high-frequency transformer is connected to the fifth switch tube, the sixth switch tube, the eighth switch tube, the seventh switch tube and the second end of the secondary side of the dual-winding high-frequency transformer in sequence, the first end of the second inductor is connected to the eighth switch tube, the second end of the second inductor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the seventh switch tube.

8. The double half-wave high frequency chain micro inverter according to claim 1, characterized in that: The high-frequency inverter circuit includes: a photovoltaic component, a filter unit and a switch unit; The first end of the photovoltaic component is connected to the first end of the filter unit and the first end of the switch unit, the second end of the photovoltaic component is connected to the second end of the filter unit and the second end of the switch unit, and the primary side of the dual-winding high-frequency transformer is connected between the third end of the switch unit and the fourth end of the switch unit.

9. The double half-wave high frequency chain micro-inverter according to claim 8, characterized in that: The filter unit includes a filter capacitor, and the switch unit includes an eleventh switch tube, a twelfth switch tube, a thirteenth switch tube and a fourteenth switch tube; The first end of the photovoltaic component is connected to the first end of the filter capacitor, the first end of the eleventh switch tube, and the first end of the twelfth switch tube. The second end of the photovoltaic component is connected to the second end of the filter capacitor, the second end of the thirteenth switch tube, and the second end of the fourteenth switch tube. The first end of the thirteenth switch tube is connected to the second end of the eleventh switch tube and the first end of the primary side of the dual-winding high-frequency transformer. The first end of the fourteenth switch tube is connected to the second end of the twelfth switch tube and the second end of the primary side of the dual-winding high-frequency transformer.

10. A photovoltaic power generation system, characterized in that: It comprises the double half-wave high frequency chain micro inverter as described in any one of claims 1 to 9.

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