Split-phase inverter

Abstract

The utility model relates to a split-phase inverter, and the inverter comprises a first filter circuit which comprises a filter capacitor CX1, a filter capacitor CX2, and a filter inductor LX employing a magnetic integrated filter inductor structure; the second filter circuit comprises a filter inductor L; the split-phase inverter circuit comprises a direct current bus DC +, a direct current bus DC-, a first switch network, a second switch network, a direct current filter capacitor C1 and a direct current filter capacitor C2, the direct current filter capacitor C1 and the direct current filter capacitor C2 are connected in series, and the first switch network and the second switch network are electrically connected with the filter inductor LX. The size and the cost of the high-frequency filter inductor are effectively reduced based on the magnetic integrated structure, and the filter performance is improved.

Description

Technical Field

[0001] The present application relates to the field of power electronic converters, and in particular to a split-phase inverter. Background Art

[0002] The energy crisis and environmental problems brought about by industrial development have promoted the rapid development and utilization of renewable energy (new energy), especially solar energy and wind energy. Due to the intermittent nature of solar energy and wind energy, energy storage and power electronic converter technology have been continuously innovated. Among them, electrochemical energy storage such as lithium batteries has become the main means. In order to meet the energy transmission between DC energy storage and AC power grid or load, power electronic converters are needed to convert DC power into AC power and transmit it to the power grid or load, or convert AC power into DC power to charge energy storage equipment, thereby improving the regulation capacity of the power grid.

[0003] Faced with different power grid systems and voltage standards around the world, for example, my country's civil power grid uses a single-phase 220V and three-phase 380V system for AC power, while the 120V system of the civil power grid represented by North America (100V in Japan, 110 / 120V in North America, etc.) uses a single-phase transformer at the user end, and the output is a single-phase three-wire split-phase wiring method to achieve 240V to 120V split-phase power supply to meet the different power requirements of household appliances. Figure 1 As shown, the three wires of the existing single-phase three-wire split-phase connection method are live wire L1, live wire L2 and neutral wire N. The live wire L1 to neutral wire N and the live wire L2 to neutral wire N are both 120V, with a phase difference of 180 degrees, and the live wire L1 to live wire L2 is 240V; the adapted household appliances low-power loads such as lighting, refrigerators, etc. are powered by 120V AC of L1 / N or L2 / N, while high-power loads such as air conditioners, induction cookers IH, etc. are powered by 240V AC of L1 / L2.

[0004] For the off-grid system of photovoltaic energy storage inverter, when the system is in grid-connected operation, it outputs 240V voltage, and the user's low-power load is powered by 120V through the grid transformer auto-coupling voltage division / phase splitting; while when the system is in off-grid operation, it needs to meet the power demand of the above low-power load and high-power load, that is, it needs to provide 120V and 240V user loads. In other words, the system needs to output two independent 120V voltages with opposite phases to meet this requirement.

[0005] In order to achieve this requirement, the simplest solution is to connect a split-phase autotransformer to the output of a single-phase 240V inverter, such as Figure 1The off-grid split-phase autotransformer shown on the user side replaces the phase-splitting function of the grid transformer with a split-phase autotransformer. However, this solution is costly, bulky, and not very practical. Alternatively, two inverter bridge arms can be used to output two independently controlled 120V AC power to achieve simultaneous output of 120V and 240V or two 120V parallel outputs to meet the needs of various user load conditions. In order to ensure the quality of the output voltage, obtain clean low-frequency 50 / 60Hz AC power, reduce interference to the grid, and reduce load losses, it is necessary to add a high-frequency filter circuit to the output end of the inverter. The existing high-frequency filter circuit is usually composed of an inductor-capacitor network, and the inductor uses a discrete inductor. The large size and high cost of the inductor are technical challenges that need to be overcome. Utility Model Content

[0006] The embodiment of the present application provides a split-phase inverter to at least solve the problem that the existing high-frequency filter inductor has large volume and high cost.

[0007] To achieve the above object, an embodiment of the present application provides a split-phase inverter, comprising:

[0008] The first filter circuit includes a filter capacitor CX1, a filter capacitor CX2 and a filter inductor LX using a magnetic integrated filter inductor structure, wherein the filter capacitor CX1 and the filter capacitor CX2 are connected in series and then connected in parallel to both ends of the filter inductor LX;

[0009] A second filtering circuit includes a filtering inductor L, one end of the filtering inductor L is connected to the midpoint of the filtering capacitor CX1 and the filtering capacitor CX2 and the zero line N, one end of the filtering capacitor CX1 connected to the filtering inductor LX is also connected to the first live wire L1, one end of the filtering capacitor CX connected to the filtering inductor LX is also connected to the second live wire L2, and the filtering inductor L is combined with the filtering capacitor CX1 and the filtering capacitor CX2 to further improve the filtering performance;

[0010] A split-phase inverter circuit includes DC busbars DC+, DC-, a first switch network, a second switch network and a DC filter capacitor C1 and a DC filter capacitor C2 connected in series. The first switch network and the second switch network are electrically connected to the filter inductor LX, that is, the outputs of the first switch network and the second switch network are respectively connected to the first live wire L1 and the second live wire L2 via the first filter circuit, and the other end of the filter inductor L is connected to the midpoint of the DC filter capacitor C1 and the DC filter capacitor C2, that is, the first live wire L1 and the second live wire L2 are connected to the midpoint of the DC filter capacitor C1 and the DC filter capacitor C2 via the second filter circuit.

[0011] In some of the embodiments, the filter inductor LX adopts an EE-type magnetic core, an EI-type magnetic core or a UF-type magnetic core. The first winding and the second winding of the filter inductor LX are wound around the side columns of the magnetic core and are coupled with each other through the first magnetic circuit to form common-mode inductor LX1 and common-mode inductor LX2. The second magnetic circuit on the middle column of the magnetic core is connected in parallel with the first magnetic circuit to form differential-mode inductor LL1 and differential-mode inductor LL2.

[0012] In some embodiments, the output end of the first switch network is connected to the filter capacitor CX1 and the first live wire L1 via the common mode inductor LX1 and the differential mode inductor LL1 of the filter inductor LX;

[0013] The output end of the second switch network is connected to the filter capacitor CX1 and the second live wire L2 via the common-mode inductor LX2 and the differential-mode inductor LL2 of the filter inductor LX.

[0014] In some embodiments, the EE type magnetic core comprises:

[0015] A first E-type magnetic core and a second E-type magnetic core are disposed opposite to each other at the open ends, a first magnetic gap is formed between the first side columns and the second side columns of the first E-type magnetic core and the second E-type magnetic core, and a second magnetic gap is formed between the middle columns of the first E-type magnetic core and the second E-type magnetic core;

[0016] A first winding, wound around the first E-shaped magnetic core and the first side column of the second E-shaped magnetic core;

[0017] A second winding is wound around the first E-shaped magnetic core and the second side column of the second E-shaped magnetic core;

[0018] The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

[0019] In some embodiments, the EI type magnetic core comprises:

[0020] An E-type magnetic core and an I-type magnetic core, wherein the I-type magnetic core is arranged at the open end of the E-type magnetic core and forms a first magnetic gap between the first side column and the second side column of the E-type magnetic core, respectively, and forms a second magnetic gap between the I-type magnetic core and the middle column of the E-type magnetic core;

[0021] A first winding, wound around a first side column of the E-shaped magnetic core;

[0022] A second winding, wound around a second side column of the E-shaped magnetic core;

[0023] The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

[0024] In some embodiments, the UF-type magnetic core comprises: two U-shaped magnetic cores with openings arranged opposite to each other, an I-shaped magnetic core is arranged in the middle of the two U-shaped magnetic cores as a middle column, a first magnetic gap is formed between the first side columns and the second side columns of the two U-shaped magnetic cores, and a second magnetic gap is formed between the I-shaped magnetic core and the U-shaped magnetic core;

[0025] A first winding, wound around the first side column of the second U-shaped magnetic core;

[0026] A second winding, wound around the second side column of the second U-shaped magnetic core;

[0027] The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

[0028] In some of the embodiments, the filter inductor L adopts a UF type magnetic core, which is arranged at one end of the filter inductor LX. A filter inductor winding is wound around the middle of the magnetic core arm of the UF type magnetic core, sharing a magnetic circuit with the filter inductor LX, thereby integrating the filter inductor L and the filter inductor LX into one, further reducing the volume of the inductor.

[0029] In some embodiments, the first winding and the second winding are in-phase coupled or reverse coupled. The in-phase coupling is suitable for enhancing the coupling effect between inductors to enable better energy transmission, and the reverse coupling is suitable for suppressing electromagnetic interference and reducing mutual inductance.

[0030] Based on the above structure, the embodiment of the present application uses magnetic integration technology to integrate the filter inductor into one, share part of the magnetic circuit, effectively reduce the volume of the inductor, and simultaneously obtain common mode filtering and differential mode filtering characteristics, effectively improve the filtering performance, and improve the driving ability of unbalanced loads.

[0031] In some embodiments, the split-phase inverter circuit further includes a third switch network electrically connected to the first switch network and the second switch network.

[0032] In some embodiments, the first switch network, the second switch network or the third switch network adopts any one of an H4 two-level topology structure, a HERIC topology structure or a T-NPC three-level topology structure.

[0033] In some of the embodiments, the split-phase inverter is connected to a single-phase three-wire split-phase power grid, and the split-phase voltage is configured to be any one of 100V, 110V, 115V, and 120V.

[0034] Compared with the related technology, the split-phase inverter provided in the embodiment of the present application effectively reduces the volume and cost of the high-frequency filter inductor based on the magnetic integrated structure and improves the filtering performance. The high-frequency filter inductor based on the present application also realizes a high-performance split-phase inverter.

[0035] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 It is a schematic diagram of the electrical structure of the split-phase grid end-user end according to the related technology;

[0038] Figure 2 is an electrical schematic diagram of a split-phase inverter according to an embodiment of the present application;

[0039] Figure 3 is another electrical schematic diagram of a split-phase inverter according to an embodiment of the present application;

[0040] Figure 4 is another electrical schematic diagram of a split-phase inverter according to an embodiment of the present application;

[0041] Figure 5 is a structural schematic diagram of a magnetic integrated filter inductor structure according to an embodiment of the present application;

[0042] Figure 6 is another structural schematic diagram of the magnetic integrated filter inductor structure according to an embodiment of the present application;

[0043] Figure 7 is another structural schematic diagram of the magnetic integrated filter inductor structure according to an embodiment of the present application.

[0044] In the figure:

[0045] 1-first filter circuit; 2-split phase inverter circuit; 3-first switch network; 4-second switch network;

[0046] 5-third switch network; 11-first winding; 12-second winding; 13-first magnetic circuit; 14-second magnetic circuit; 15-first magnetic gap; 16-second magnetic gap; 17-filter inductor winding; 18-inductor magnetic circuit. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0048] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0049] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0050] If the off-grid power supply demand of the user side is to be met, the photovoltaic energy storage split-phase inverter needs to output a single-phase three-wire split-phase voltage and have load balancing capability. To meet the above requirements, the embodiment of the present application provides a split-phase inverter. Figure 2-4 is an electrical schematic diagram of a split-phase inverter according to an embodiment of the present application. Figure 2-4 As shown, the split-phase inverter includes: a first filter circuit 1, a second filter circuit, a split-phase inverter circuit 2 and other components. Those skilled in the art can understand that Figure 2-4 The split-phase inverter structure shown in the figure does not constitute a limitation of the split-phase inverter, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0051] Combine the following Figure 2-4 A detailed introduction to the various components of the split-phase inverter:

[0052] The first filter circuit 1 includes a filter capacitor CX1, a filter capacitor CX2, and a filter inductor LX using a magnetic integrated filter inductor structure. The filter capacitor CX1 and the filter capacitor CX2 are connected in series and then connected in parallel to both ends of the filter inductor LX. Figure 5-Figure 7 As shown, the filter inductor LX adopts an EE type magnetic core, an EI type magnetic core or a UF type magnetic core, the first winding 11 and the second winding 12 of the filter inductor LX are wound on the side columns of the magnetic core, and are coupled to each other through the first magnetic circuit 13 to form common mode inductors LX1 and common mode inductors LX2, and the second magnetic circuit 14 on the center column of the magnetic core is connected in parallel with the first magnetic circuit 13 to form differential mode inductors LL1 and differential mode inductors LL2;

[0053] The second filtering circuit includes a filtering inductor L, one end of which is connected to the midpoint of the filtering capacitor CX1 and the filtering capacitor CX2 and the zero line N, the filtering inductor L is combined with the filtering capacitor CX1 and the filtering capacitor CX2 to further improve the filtering performance, one end of the filtering capacitor CX1 connected to the filtering inductor LX is also connected to the first live wire L1, one end of the filtering capacitor CX connected to the filtering inductor LX is also connected to the second live wire L2, and the other end of the filtering inductor L is connected to the midpoint of the DC filtering capacitor C1 and the DC filtering capacitor C2, that is, the first live wire L1 and the second live wire L2 are connected to the midpoint of the DC filtering capacitor C1 and the DC filtering capacitor C2 via the second filtering circuit;

[0054] The split-phase inverter circuit 2 includes DC busbars DC+, DC-, a first switch network 3, a second switch network 4, and a DC filter capacitor C1 and a DC filter capacitor C2 connected in series. The DC filter capacitors C1 and C2 divide the voltage of the DC busbar and output the split-phase voltage through the first and second switch networks.

[0055] The first switch network 3 and the second switch network 4 are electrically connected to the filter inductor LX, that is, the outputs of the first switch network 3 and the second switch network 4 are respectively connected to the first live wire L1 and the second live wire L2 via the first filter circuit 1. Figure 2-4 As shown, the output end of the first switch network 3 is connected to the filter capacitor CX1 and the first live wire L1 via the common-mode inductor LX1 and the differential-mode inductor LL1 of the filter inductor LX; the output end of the second switch network 4 is connected to the filter capacitor CX1 and the second live wire L2 via the common-mode inductor LX2 and the differential-mode inductor LL2 of the filter inductor LX, thereby utilizing the filter circuit to filter the high-frequency component output.

[0056] When applied, the split-phase inverter output is preferably configured as split-phase 120V, 240V and parallel output single-phase 120V, wherein the parallel output single-phase 120V can be used to meet the power needs of low-voltage high-power single loads when the photovoltaic energy storage inverter off-grid system is in off-grid operation. When the split-phase inverter is connected to a single-phase three-wire split-phase power grid, the split-phase voltage can be configured to any one of 100V, 110V, 115V, and 120V.

[0057] When the split-phase inverter of the embodiment of the present application is off-grid, a controller is used to automatically detect whether the first live wire L1 and the second live wire L2 are output in parallel. When parallel operation is detected, the mode is automatically switched to parallel output mode. At this time, the output voltage phase and amplitude of the first live wire L1 and the second live wire L2 are the same, so as to improve the inverter's load capacity for low-voltage and high-power electrical appliances. It is especially suitable for household applications without 240V electrical appliance requirements. The controller's detection method for the live wire is an existing solution and will not be described in detail here.

[0058] In some of these embodiments, reference Figure 4 As shown, the split-phase inverter circuit 2 further includes a third switch network 5 electrically connected to the first switch network 3 and the second switch network 4 .

[0059] The first switch network 3, the second switch network 4 or the third switch network 5 adopts any one of the H4 two-level topology structure, the HERIC topology structure or the T-NPC three-level topology structure, for example but not limited to:

[0060] refer to Figure 2 As shown, the first switch network 3 and the second switch network 4 adopt an H4 two-level topology. The first switch network 3 includes switch tubes Q1 and Q2, and the second switch network 4 includes switch tubes Q3 and Q4. The first switch network 3 and the second switch network 4 form a full-bridge inverter circuit, which is alternately turned on under the control of the inverter to convert the electric energy of the DC bus into the required AC electric energy output, and the connected filter inductors and filter capacitors are used to reduce high-frequency harmonics, smooth the output voltage waveform, and reduce the impact on the power grid or load.

[0061] refer to Figure 3 As shown, the first switch network 3 and the second switch network 4 adopt a T-NPC (T-type neutral point clamp) three-level topology structure, the second switch network 3 includes switch tubes Q1, Q2, Q5, and Q6, and the second switch network 4 includes switch tubes Q3, Q4, Q7, and Q8. The switch tubes Q1, Q2, Q3, and Q4 form two traditional H-bridge arms, and the additional switch tubes Q5, Q6, Q7, and Q8 are used to generate a neutral point voltage.

[0062] When the switch tubes Q1 and Q4 are turned on and the other switches are turned off, the voltage across the load is equal to the positive DC voltage. When the switch tubes Q2 and Q3 are turned on and the other switches are turned off, the voltage across the load is equal to the negative DC voltage. When the switch tubes Q1 and Q2 or the switch tubes Q3 and Q4 are turned on at the same time, the voltage across the load is zero, and both ends of the load are connected to the midpoint of the DC power supply. By turning on and off the switch tubes Q5 to Q8, it is possible to convert between zero potential and positive / negative DC potential, thereby realizing three-level output, significantly improving output waveform distortion, reducing filter inductance and capacitance, and having a high cost-effectiveness ratio.

[0063] refer to Figure 4 As shown, the first switch network 3, the second switch network 4, and the third switch network 5 adopt the HERIC topology. The first switch network 3 includes switch tubes Q1 and Q2, the second switch network 4 includes switch tubes Q3 and Q4, and the third switch network 5 includes switch tubes Q5 and Q6 to form a HERIC inverter. The lateral bridge arm composed of switch tubes Q5 and Q6 is used to realize three-level, reduce output distortion, improve common-mode suppression capability, and improve the efficiency and reliability of the inverter. The HERIC topology reduces switching losses, thereby improving the efficiency of the entire system, especially under partial load conditions, and is suitable for solar photovoltaic systems. In addition, since energy circulates through capacitors instead of being dissipated in switches, HERIC inverters can also achieve higher reliability.

[0064] The switch tubes Q1 - Q8 are usually power transistors with body diodes, such as IGBT, MOSFET or other types of power semiconductor devices.

[0065] refer to Figure 5-Figure 7 As shown, the specific structure of the filter inductor LX using the magnetic integrated filter inductor structure in the above embodiment is described as follows:

[0066] refer to Figure 5 As shown, the EE-type magnetic core includes: a first E-type magnetic core and a second E-type magnetic core that are arranged opposite to each other at open ends; a first magnetic gap 15 is formed between the first side columns and the second side columns of the first E-type magnetic core and the second E-type magnetic core, respectively; a second magnetic gap 16 is formed between the middle columns of the first E-type magnetic core and the second E-type magnetic core; a first winding 11 is wound around the first side columns of the first E-type magnetic core and the second E-type magnetic core; a second winding 12 is wound around the second side columns of the first E-type magnetic core and the second E-type magnetic core; the common-mode inductance LX1, the common-mode inductance LX2, the differential-mode inductance LL1, and the differential-mode inductance LL2 are adjusted by the magnetic gap sizes and size ratios of the first magnetic gap 15 and the second magnetic gap 16 to flexibly meet the output filtering performance requirements.

[0067] refer to Figure 6As shown, the EI type magnetic core includes: an E type magnetic core and an I type magnetic core. The I type magnetic core is arranged at the open end of the E type magnetic core and forms a first magnetic gap 15 between the first side column and the second side column of the E type magnetic core respectively, and forms a second magnetic gap 16 between the I type magnetic core and the middle column of the E type magnetic core. The first winding 11 is wound around the first side column of the E type magnetic core, and the second winding 12 is wound around the second side column of the E type magnetic core. The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by the magnetic gap sizes and size ratios of the first magnetic gap 15 and the second magnetic gap 16 to flexibly meet the output filtering performance requirements.

[0068] refer to Figure 7 As shown, the UF type magnetic core includes: two U-shaped magnetic cores with openings arranged opposite to each other, an I-shaped magnetic core is arranged in the middle of the two U-shaped magnetic cores as a middle column, a first magnetic gap 15 is formed between the first side columns and the second side columns of the two U-shaped magnetic cores, a second magnetic gap 16 is formed between the I-shaped magnetic core and the U-shaped magnetic core, a first winding 11 is wound around the first side columns of the two U-shaped magnetic cores, and a second winding 12 is wound around the second side columns of the two U-shaped magnetic cores, and the common mode inductance LX1, the common mode inductance LX2, the differential mode inductance LL1, and the differential mode inductance LL2 are adjusted by the magnetic gap sizes and size ratios of the first magnetic gap 15 and the second magnetic gap 16 to flexibly meet the output filtering performance requirements.

[0069] Based on the above Figure 7 The structure of the filter inductor LX shown in the figure, the embodiment of the present application can also integrate the filter inductor L. Specifically, the filter inductor L adopts a UF type magnetic core, which is arranged at one end of the filter inductor LX, and the filter inductor winding 17 is wound in the middle of the magnetic core arm of the UF type magnetic core. The inductor magnetic circuit 18 of the filter inductor L shares part of the magnetic circuit with the filter inductor LX, such as Figure 7 The first magnetic circuit of the middle filter inductor LX and the magnetic circuit at the open end of the filter inductor L both use the magnetic core body of the right U-shaped magnetic core of the filter inductor LX, thereby integrating the filter inductor L and the filter inductor LX into one, further reducing the inductor volume.

[0070] In the above embodiments, the first winding 11 and the second winding 12 are in-phase coupled or reverse coupled. The in-phase coupling is suitable for enhancing the coupling effect between inductors to enable better energy transmission, and the reverse coupling is suitable for suppressing electromagnetic interference and reducing mutual inductance.

[0071] Optionally, the magnetic core includes ferrite, alloy magnetic powder core and silicon steel sheet.

[0072] Based on the above structure, the embodiment of the present application uses magnetic integration technology to integrate the filter inductor into one, share part of the magnetic circuit, effectively reduce the volume of the inductor, and simultaneously obtain common mode filtering and differential mode filtering characteristics, effectively improve the filtering performance, and improve the driving ability of unbalanced loads.

[0073] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A split-phase inverter, characterized in that: include: The first filter circuit includes a filter capacitor CX1, a filter capacitor CX2 and a filter inductor LX using a magnetic integrated filter inductor structure, wherein the filter capacitor CX1 and the filter capacitor CX2 are connected in series and then connected in parallel to both ends of the filter inductor LX; A second filtering circuit includes a filtering inductor L, one end of the filtering inductor L is connected to the midpoint of the filtering capacitor CX1 and the filtering capacitor CX2 and the zero line N, one end of the filtering capacitor CX1 connected to the filtering inductor LX is also connected to the first live wire L1, and one end of the filtering capacitor CX connected to the filtering inductor LX is also connected to the second live wire L2; The split-phase inverter circuit includes DC busbars DC+, DC-, a first switch network, a second switch network and a DC filter capacitor C1 and a DC filter capacitor C2 connected in series. The first switch network and the second switch network are electrically connected to the filter inductor LX, and the other end of the filter inductor L is connected to the midpoint of the DC filter capacitor C1 and the DC filter capacitor C2.

2. The split-phase inverter according to claim 1, characterized in that: The filter inductor LX adopts an EE-type magnetic core, an EI-type magnetic core or a UF-type magnetic core. The first winding and the second winding of the filter inductor LX are wound on the side columns of the magnetic core and are coupled with each other through the first magnetic circuit to form common-mode inductors LX1 and LX2. The second magnetic circuit on the center column of the magnetic core is connected in parallel with the first magnetic circuit to form differential-mode inductors LL1 and LL2.

3. The split-phase inverter according to claim 2, characterized in that: The output end of the first switch network is connected to the filter capacitor CX1 and the first live wire L1 via the common mode inductor LX1 and the differential mode inductor LL1 of the filter inductor LX; The output end of the second switch network is connected to the filter capacitor CX1 and the second live wire L2 via the common-mode inductor LX2 and the differential-mode inductor LL2 of the filter inductor LX.

4. The split-phase inverter according to claim 3, characterized in that: The EE type magnetic core comprises: A first E-type magnetic core and a second E-type magnetic core are disposed opposite to each other at the open ends, a first magnetic gap is formed between the first side columns and the second side columns of the first E-type magnetic core and the second E-type magnetic core, and a second magnetic gap is formed between the middle columns of the first E-type magnetic core and the second E-type magnetic core; A first winding, wound around the first E-shaped magnetic core and the first side column of the second E-shaped magnetic core; A second winding is wound around the first E-shaped magnetic core and the second side column of the second E-shaped magnetic core; The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

5. The split-phase inverter according to claim 3, characterized in that: The EI type magnetic core comprises: An E-type magnetic core and an I-type magnetic core, wherein the I-type magnetic core is arranged at the open end of the E-type magnetic core and forms a first magnetic gap between the first side column and the second side column of the E-type magnetic core, respectively, and forms a second magnetic gap between the I-type magnetic core and the middle column of the E-type magnetic core; A first winding, wound around a first side column of the E-shaped magnetic core; A second winding, wound around a second side column of the E-shaped magnetic core; The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

6. The split-phase inverter according to claim 3, characterized in that: The UF-type magnetic core comprises: two U-shaped magnetic cores with openings arranged opposite to each other, an I-shaped magnetic core is arranged in the middle of the two U-shaped magnetic cores as a middle column, a first magnetic gap is formed between the first side columns and the second side columns of the two U-shaped magnetic cores, and a second magnetic gap is formed between the I-shaped magnetic core and the U-shaped magnetic core; A first winding, wound around the first side column of the second U-shaped magnetic core; A second winding, wound around the second side column of the second U-shaped magnetic core; The common mode inductor LX1, the common mode inductor LX2, the differential mode inductor LL1, and the differential mode inductor LL2 are adjusted by adjusting the magnetic gap sizes and size ratios of the first magnetic gap and the second magnetic gap.

7. The split-phase inverter according to any one of claims 4 to 6, characterized in that: The filter inductor L adopts a UF type magnetic core, which is arranged at one end of the filter inductor LX. A filter inductor winding is wound around the middle of the magnetic core arm of the UF type magnetic core, sharing a magnetic circuit with the filter inductor LX, thereby integrating the filter inductor L and the filter inductor LX into one.

8. The split-phase inverter according to claim 1, characterized in that: The split-phase inverter circuit further includes a third switch network electrically connected to the first switch network and the second switch network.

9. The split-phase inverter according to claim 8, characterized in that: The first switch network, the second switch network or the third switch network adopts any one of an H4 two-level topology structure, a HERIC topology structure or a T-NPC three-level topology structure, and the first switch network, the second switch network or the third switch network respectively includes a power transistor with a body diode.

10. The split-phase inverter according to claim 7, characterized in that: The split-phase inverter is connected to a single-phase three-wire split-phase power grid, and the split-phase voltage is configured to be any one of 100V, 110V, 115V, and 120V.

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