Inverter, rectifier, frequency converter and photovoltaic power generation system
By separating the connection methods of high-frequency ripple current and power frequency current in a two-layer architecture inverter, the problems of poor filtering effect and high cost of traditional inverters are solved, achieving more efficient filtering and lower cost design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2026-03-10
AI Technical Summary
The traditional AC filter layout of inverters results in poor filtering performance and high cost, and the design is complex, making it difficult to balance filtering performance and cost.
The inverter adopts a dual-layer architecture, connecting different filter circuits through different output terminals of the inverter inductor to separate high-frequency ripple current and power frequency current, simplifying wiring design, shortening filter circuits, and improving electromagnetic compatibility and power density.
It improves filtering performance, saves material costs, simplifies design, and enhances the electromagnetic compatibility and power density of the inverter.
Smart Images
Figure CN121643508A_ABST
Abstract
Description
[0001] This application is a divisional application. The original application has the application number 202411057897.1 and the original application date is August 2, 2024. The entire contents of the original application are incorporated herein by reference. Technical Field
[0002] This application relates to the field of power technology, and in particular to an inverter, rectifier, frequency converter and photovoltaic power generation system. Background Technology
[0003] An inverter (INV) is a device that converts direct current (DC) to alternating current (AC). For high-power inverters, to improve the overall power density, a dual-layer architecture is typically used (one layer primarily for power conversion, and the other for power output and sampling control). Traditional inverters often employ long AC filter loops, leading to poor filtering performance and high costs; alternatively, shortening the filter loops requires complex wiring methods, which are difficult to design and also expensive. Therefore, how to achieve a balance between effective filtering and cost in high-power inverters is a pressing issue that needs to be addressed. Summary of the Invention
[0004] This application provides an inverter, rectifier, frequency converter, and photovoltaic power generation system that can improve filtering effect and save material costs.
[0005] In a first aspect, an inverter is provided, including a first power board, a second power board, an inverter circuit, a first filter circuit, a second filter circuit, and a third filter circuit. The first power board is used to fix the inverter circuit and the first filter circuit, and the first filter circuit is electrically connected to the DC input terminal of the inverter circuit through the first power board. The second filter circuit includes one or more inverter inductors, and the output terminals of the inverter inductors are electrically connected to the input terminal of the first filter circuit sequentially through a first wire and the first power board. The second power board is used to fix the third filter circuit, and the third filter circuit is electrically connected to the output terminal of the inverter inductors through the second power board and a second wire. The third filter circuit is used to electrically connect to the power grid or a load. The inverter circuit converts DC power into AC power and transmits the AC power to the inverter inductors. The inverter inductors filter the AC power and transmit a portion of the filtered AC power to the first filter circuit through the first wire, and transmit the other portion of the filtered AC power to the third filter circuit through the second wire. In this design, the impedance of the electrical connection between the output terminal of the inverter inductor and the output terminal of the first filter circuit to the high-frequency ripple current is less than that between the output terminal of the inverter inductor and the output terminal of the third filter circuit. The frequency of the high-frequency ripple current is higher than the power frequency. This configuration allows the AC current filtered by the inverter inductor to automatically separate the high-frequency ripple current from the power frequency current, thus ensuring the quality of the inverter's output current. Simultaneously, since the high-frequency ripple current flows directly to the first filter circuit through the first conductor, the high-frequency ripple filtering loop can be shortened, improving the inverter's electromagnetic compatibility. Furthermore, since the power frequency current flows directly to the third filter circuit through the second conductor, the design of the first power board can be simplified, the wiring between the inverter inductor and the third filter circuit can be simplified, the inverter's wiring space can be reduced, and the inverter's power density can be increased.
[0006] In one possible implementation, the diameter of the first conductor is smaller than the diameter of the second conductor. Since the power frequency current is much larger than the high-frequency ripple current, this configuration can reduce the heat generated by the second conductor and improve the power conversion efficiency of the inverter.
[0007] In one possible implementation, the inverter inductor includes a coil, a magnetic core, and a package, with the coil wound around the magnetic core and the coil and magnetic core disposed within the package.
[0008] In one possible implementation, the first filter circuit includes a capacitor.
[0009] In one possible implementation, the third filter circuit includes a differential-mode inductor used to filter the differential-mode signal in another portion of the AC power after it has been filtered by the inverter inductor.
[0010] In one possible implementation, the third filter circuit includes a common-mode inductor used to filter common-mode signals in another portion of the AC power filtered by the inverter inductor.
[0011] Secondly, an inverter is provided, including a first power board, a second power board, an inverter circuit, a first filter circuit, a second filter circuit, and a third filter circuit. The first power board is used to fix the inverter circuit and the first filter circuit, and the first filter circuit is electrically connected to the DC input terminal of the inverter circuit through the first power board. The second filter circuit includes one or more inverter inductors, and the first output terminal of the inverter inductor is electrically connected to the input terminal of the first filter circuit through a first wire. The second power board is used to fix the third filter circuit, and the third filter circuit is electrically connected to the second output terminal of the inverter inductor through the second power board and the second wire in sequence. The third filter circuit is used to electrically connect to the power grid or a load. The inverter circuit converts DC power into AC power and transmits the AC power to the inverter inductor. The inverter inductor filters the AC power and transmits a portion of the filtered AC power to the first filter circuit through the first wire, and transmits the other portion of the filtered AC power to the third filter circuit through the second wire. In this design, the impedance of the electrical connection line between the first output terminal of the inverter inductor and the output terminal of the first filter circuit to the high-frequency ripple current is less than that between the second output terminal of the inverter inductor and the output terminal of the third filter circuit. The frequency of the high-frequency ripple current is higher than the power frequency. This configuration allows the AC current filtered by the inverter inductor to automatically separate the high-frequency ripple current from the power frequency current, thus ensuring the quality of the inverter's output current. Simultaneously, since the high-frequency ripple current flows directly to the first filter circuit through the first conductor, the high-frequency ripple filtering loop can be shortened, improving the inverter's electromagnetic compatibility. Furthermore, since the power frequency current flows directly to the third filter circuit through the second conductor, the design of the first power board can be simplified, the wiring between the inverter inductor and the third filter circuit can be simplified, the inverter's wiring space can be reduced, and the inverter's power density can be increased.
[0012] In other possible implementations of the second aspect, please refer to the implementations of the first aspect described above, which will not be elaborated further. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of a power generation system provided in an embodiment of this application.
[0014] Figure 2 This application provides a schematic diagram of an inverter.
[0015] Figure 3 This application provides a schematic diagram of an inverter.
[0016] Figure 4This application provides a schematic diagram of an inverter.
[0017] Figure 5 This is a schematic diagram of the current applicable to the embodiments of this application.
[0018] Figure 6 This is a schematic diagram of an inductor applicable to embodiments of this application.
[0019] Figure 7 This is a schematic diagram of the structure of the first power board, the second power board, and the first filter provided in the embodiments of this application.
[0020] Figure 8 This is a schematic diagram of a power generation system provided in an embodiment of this application.
[0021] Figure 9 This is a schematic diagram of a power generation system provided in an embodiment of this application.
[0022] Figure label:
[0023] 100 - Inverter; 200 - First power board; 300 - Second power board; 400 - First filter; 210 - Inverter circuit; 220 - First filter circuit; 21 - First input terminal of the first power board; 22 - Second input terminal of the first power board; 23 - Output terminal of the first power board; 31 - Input terminal of the second power board; 32 - Output terminal of the second power board; 41 - Input terminal of the first filter; 42 - First output terminal of the first filter; 43 - Second output terminal of the first filter; 410 - Second filter circuit; 411 - Inverter inductor; 4111 - Coil; 4112 - Magnetic core; 4113 - Package. Detailed Implementation
[0024] The following explains the terminology that may appear in the embodiments of this application.
[0025] A dual-layer inverter is a power converter that transforms direct current (DC) to alternating current (AC). It primarily employs a dual-layer power board design, separating the control and power circuitry onto two different power boards. The control circuitry, located on the second power board, is responsible for controlling the inverter's operating status and output voltage parameters. This control circuitry typically includes a microprocessor or digital signal processor (DSP) to process input signals, monitor output voltage and current, and calculate control algorithms. Furthermore, the control circuitry includes protection circuitry to monitor the inverter's operating status and take timely protective measures in case of faults or abnormal conditions. The inverter circuitry, located on the first power board, controls the switching states of the switching devices according to the commands issued by the control circuitry, converting the DC power supply into AC power.
[0026] Inverter inductors are commonly used components in inverter circuits for filtering and stabilizing output voltage. They suppress current fluctuations through self-inductance, thereby reducing output voltage ripple and harmonic content. When the inverter's switching devices switch on and off, pulse currents at the switching frequency are generated. These pulse currents pass through the inverter inductor. Due to its self-inductance, the inverter inductor resists current changes, resulting in a smoother output current and reduced harmonic components. Simultaneously, the inverter inductor can store energy. When the switching devices are off, the inverter inductor releases the stored energy to maintain the continuity of the output current, thus stabilizing the output voltage. Furthermore, it can suppress electromagnetic interference and reduce electromagnetic radiation.
[0027] The first filter circuit is a commonly used circuit in inverters, used to further smooth the output current and reduce current ripple. The capacitor in the first filter circuit can store charge and provide electrical energy between the positive and negative half-cycles of the current, thereby reducing current ripple. The resistor in the first filter circuit mainly plays the role of dissipating current, making the output current more stable.
[0028] The input midpoint of an inverter circuit refers to the intermediate connection point between the two polarities of the inverter's input power supply. Typically, the inverter's input power supply is DC, and this midpoint is the connection point between the positive and negative terminals of the DC power supply. The input midpoint plays a role in balancing and stabilizing the current in the inverter, and also helps reduce current surges and voltage fluctuations, improving the inverter's stability and performance. When using an inverter in an AC power grid, the input midpoint can also be connected to ground (ground wire) for better electrical safety and electromagnetic compatibility.
[0029] The technical solutions in this application will now be described with reference to the accompanying drawings.
[0030] Figure 1 This is a schematic diagram of a photovoltaic (PV) power generation system, which includes PV modules, an AC power grid, and an inverter. The output ports of M PV modules are connected to the input ports of the inverter, and the output ports of the inverter are connected to the input ports of the AC power grid. The PV modules generate direct current (DC), and the inverter converts the DC power into AC power, which is then fed into the AC power grid to provide AC power to external systems.
[0031] It should be noted that the aforementioned photovoltaic modules refer to devices that directly convert solar energy into electrical energy using the photovoltaic effect that occurs in semiconductor materials under illumination. Photovoltaic modules can also be called photovoltaic arrays, solar panels, etc.
[0032] Inverters in photovoltaic power generation systems are typically divided into single-layer and double-layer architectures. In double-layer inverters, the wiring layout of the first filter circuit can be divided into two types. The first wiring layout is that the first filter circuit follows the second power board, such as... Figure 2 As shown, the output terminal of the first power board is electrically connected to the input terminal of the filter. The output terminal of the filter is directly electrically connected to the input terminal of the second power board. DC power is input from the first input terminal of the first power board to the inverter circuit, converting it to AC power. The AC power is then output from the output terminal of the first power board to the input terminal of the filter. The AC power is input from the input terminal of the second power board to the first filter circuit. After filtering by the first filter circuit, ripple current is filtered out, and the output AC power is output from the output terminal of the second power board to the AC mains or load. In the above wiring layout of the first filter circuit, the ripple current has a long filtering path, affecting the filtering effect. Furthermore, for electrical safety and electromagnetic compatibility, the output terminal of the first filter circuit is electrically connected to the midpoint of the input terminal of the inverter circuit, resulting in a long path between them, which is not conducive to cost savings.
[0033] The second wiring layout is that the first filter circuit follows the first power board, such as... Figure 3 As shown, the output of the filter receives the AC power processed by the inverter inductor and inputs it to the second input of the first power board. After the AC power passes through the first filter circuit to filter out the ripple current, a certain amount of wiring space is required on the first power board to connect the output of the filter to the output of the first power board, so that the AC power is output from the output of the first power board to the input of the second power board. In the wiring layout of the first filter circuit described above, the AC power needs to be transferred from the first power board to the second power board, which requires a large amount of wiring space on the first power board, thus increasing the design difficulty and cost.
[0034] Therefore, this application provides an inverter that enables a more reasonable wiring layout for the first filter circuit, improves the filtering effect, and saves material costs.
[0035] This application provides an inverter 100. Figure 4 This is a schematic diagram of an inverter 100, which includes a first power board 200, a second power board 300, and a first filter 400. The first power board 200 and the second power board 300 can be stacked, with the second power board 300 located above the first power board 200, or the first power board 200 and the second power board 300 can be placed horizontally. The first filter 400 is placed independently of the first power board 200 and the second power board 300.
[0036] Specifically, the first power board 200 includes a first input terminal 21, a second input terminal 22, and an output terminal 23, used to fix the inverter circuit 210 and the first filter circuit 220. The first input terminal 21 of the first power board 200 is used to input DC power from a DC system or rectifier, the inverter circuit 210 is used to convert the DC power to AC power, and the output terminal 23 of the first power board is used to output AC power. The first filter 400 includes an input terminal 41, a second filter circuit 410, a first output terminal 42, and a second output terminal 43. The first output terminal 42 and the second output terminal 43 are collectively referred to as the output terminals of the inverter inductor 411. The second filter circuit 410 may include one or more inverter inductors 411 connected in series; the following description uses one inverter inductor 411 as an example.
[0037] The input terminal 41 of the first filter 400 is electrically connected to the output terminal 23 of the first power board 200. Alternating current is input from the input terminal 41 of the first filter 400 to the inverter inductor 411. The inverter inductor 411 is used to filter the alternating current output by the inverter circuit 210. A portion of the alternating current processed by the inverter inductor 411 is output from the first output terminal 42, and another portion of the alternating current processed by the inverter inductor 411 is output from the second output terminal 43.
[0038] It should be noted that, as Figure 5 As shown, after processing by inverter inductor 411, the high-frequency ripple current is superimposed on the power frequency current on the time T and current I coordinate axis. High-frequency ripple current is a current fluctuation or ripple caused by alternating or periodically changing voltage sources in the circuit. It easily causes electronic components to periodically absorb and release energy, leading to component heating, increased energy consumption, and potentially shortened component lifespan. It also generates electromagnetic interference, affecting the performance of other electronic devices or circuits. In some cases, ripple current may cause oscillation problems in the circuit, leading to unstable operating conditions and affecting system performance and reliability. The frequency of the high-frequency ripple current is greater than the frequency of the power frequency current.
[0039] To ensure a stable power frequency current output from inverter 100, the high-frequency ripple current of the AC output from inverter inductor 411 needs to be eliminated. For further details, please refer to... Figure 4The inverter inductor 411 is electrically connected to the first power board 200 via the first conductor 51, thereby allowing a portion of the AC power filtered by the inverter inductor 411 to be transmitted to the first power board 200 via the first conductor 51. The first power board 200 then transmits a portion of the AC power filtered by the inverter inductor 411 to the first filter circuit 220 via internal wiring. Further, the inverter inductor 411 is electrically connected to the second power board 300, which carries the third filter circuit 310, via the second conductor 52, thereby allowing another portion of the AC power filtered by the inverter inductor 411 to be transmitted to the second power board 300 via the second conductor 52. The second power board 300 then transmits another portion of the AC power filtered by the inverter inductor 411 to the third filter circuit 310 via internal wiring. The third filter circuit 310 is used to connect to the power grid or a load. The impedance of the electrical connection line between the output terminal of the inverter inductor 411 and the output terminal of the first filter circuit 220 to the high-frequency ripple current is less than the impedance of the electrical connection line between the output terminal of the inverter inductor 411 and the output terminal of the third filter circuit 310 to the high-frequency ripple current.
[0040] Specifically, high-frequency ripple current is output from the first output terminal 42 to the first input terminal 22 of the first power board 200. The input terminal of the first filter circuit 220 is electrically connected to the first input terminal 22 of the first power board, and the output terminal of the first filter circuit 220 is connected to the midpoint of the input terminal of the inverter circuit. The high-frequency ripple current is filtered by the first filter circuit 220. The second power board 300 includes an input terminal 31, a third filter circuit 310, and an output terminal 32. The third filter circuit 310 is connected in series between the input terminal 31 and the output terminal 32 of the second power board 300. After the AC power is output from the second output terminal 43 of the first filter 400 to the input terminal 31 of the second power board, it is filtered by the third filter circuit 310 and then output from the output terminal 32 of the second power board to the AC power grid or the load.
[0041] This configuration allows the AC current filtered by the inverter inductor 411 to automatically separate high-frequency ripple current and mains frequency current, thereby ensuring the quality of the inverter 100's output current. Simultaneously, since the high-frequency ripple current flows directly to the first filter circuit 220 through the first conductor 51, the high-frequency ripple filtering loop is shortened, improving the electromagnetic compatibility of the inverter 100. Furthermore, since the mains frequency current flows directly to the third filter circuit 310 through the second conductor 52, the design of the first power board 200 is simplified, the wiring between the inverter inductor 411 and the third filter circuit 310 is simplified, the wiring space of the inverter 100 is reduced, and the power density of the inverter 100 is increased.
[0042] It should be noted that in practical applications, the first output terminal 42 and the second output terminal 43 can be either two independent terminals or combined into one terminal. When the first output terminal 42 and the second output terminal 43 are two independent terminals, the first output terminal 42 is electrically connected to the first power board 200 through the first wire 51, and the internal wiring of the first power board 200 further connects the first output terminal 42 to the first filter circuit 220. The second output terminal 43 is electrically connected to the second power board 300 through the second wire 52, and the internal wiring of the second power board 300 further connects the second output terminal 43 to the third filter circuit 310. When the first output terminal 42 and the second output terminal 43 are combined into a single terminal, the first wire 51 and the second wire 52 are wrapped with insulation to form a single wire. One end of the wire is connected to the terminal formed by the first output terminal 42 and the second output terminal 43. There is a gap in the insulation in the middle of the wire, which is used to lead out the first wire 51, thereby electrically connecting the first wire 51 to the first power board 200 and electrically connecting the second wire 52 to the second power board 300.
[0043] For embodiments where the first output terminal 42 and the second output terminal 43 are two independent terminals, please refer to [link to documentation]. Figure 6 .like Figure 6 As shown, the inverter inductor 411 includes a coil 4111, a magnetic core 4112, and a package 4113. The coil 4111 is wound around the magnetic core 4112, and the coil 4111 and the magnetic core 4112 are disposed within the package 4113. The end of the coil 4111 is divided into two independent terminals, namely a first output terminal 42 and a second output terminal 43. The first output terminal 42 is used to electrically connect to the first power board 200 through a first wire 51, and the second output terminal 43 is used to electrically connect to the second power board 300 through a second wire 52. It is worth mentioning that, for display purposes, Figure 6 The housing of the first filter is concealed. In practical applications, a housing for housing the inverter inductor 411 can be provided to ensure the structural stability of the inverter inductor 411. The first filter 400 also includes a third wire (not shown). The inverter inductor 411 is connected to the input terminal 41 of the first filter 400 through the third wire. The third wire can be led out from the coil 4111 of the inverter inductor 411, or the third wire can be connected to the wire of the coil.
[0044] See Figure 7 , Figure 7This is a schematic diagram of the structure of the first power board 200, the second power board 300, and the first filter 400. In this embodiment, the first output terminal 42 and the second output terminal 43 are combined into a single terminal. The first wire 51 and the second wire 52 are wrapped with insulation to form a single wire. At the middle of this wire, the first wire 51 extends from a notch in the insulation, thus electrically connecting the first wire 51 to the first power board 200. The diameter of the first wire 51 is smaller than the diameter of the second wire 52. As described above, since the power frequency current is much larger than the high-frequency ripple current, this arrangement reduces the heat generated by the second wire 52 and improves the power conversion efficiency of the inverter 100.
[0045] Furthermore, the first filter 400 includes a housing 420 and a second filter circuit 410, the second filter circuit 410 including three inverter inductors 411. It is worth noting that in practical applications, the number of inverter inductors 411 can be set as needed, and is not limited to three.
[0046] Optionally, the first output terminal 42 and the second output terminal 43 can be amplified and processed by superimposed switching circuits such as multiplexers, or by using amplifiers and other related circuits to improve the decoupling effect of ripple current and power current. This application embodiment does not specifically limit this.
[0047] The inverter provided in this application embodiment connects the first filter 400 to two output lines with different impedances to high-frequency ripple current, changing the direction of the ripple current in the AC power. This allows the high-frequency ripple current to be decoupled from the AC power at the first output terminal 42 and the second output terminal 43 of the first filter 400, thereby improving the filtering effect. At the same time, it avoids the high-frequency ripple current from following the AC power input to the second power board 300 for filtering, effectively shortening the ripple current filtering path and reducing the instability in the AC power earlier. In addition, it also avoids the transfer process where the high-frequency ripple current follows the AC power input to the first power board 200, is filtered by the first filter circuit 220, and then outputs from the first power board 200 to the second power board 300, reducing the wiring space of the first power board 200 and saving costs.
[0048] In some embodiments, the inverter circuit 210 includes a drive control circuit, a DC-DC converter circuit, a drive circuit, a protection and detection circuit, a resonant capacitor, an output current sampling circuit, etc. The drive control circuit may include an oscillator and a modulator, and the drive circuit may include a power output transistor and a high-voltage transformer. This application embodiment does not specifically limit these aspects.
[0049] In some embodiments, the first filter circuit includes a capacitor, through which high-frequency ripple current is input to the capacitor of the first filter circuit 220 and filtered. The first filter circuit 220 may also include bipolar transistors, unipolar transistors, and integrated operational amplifiers, etc.
[0050] In some embodiments, the third filter circuit 310 includes a differential-mode inductor for filtering differential-mode signals in the AC power supply. The input terminal of the differential-mode inductor is electrically connected to the input terminal 31 of the second power board, and the output terminal of the differential-mode inductor is electrically connected to the output terminal 32 of the second power board. The AC power supply is input from the input terminal 31 of the second power board to the differential-mode inductor for further filtering of differential-mode signals. The filtered AC power supply is then output to the output terminal 32 of the second power board. In other embodiments, the third filter circuit 310 includes a common-mode inductor for filtering common-mode signals in the AC power supply. The input terminal of the common-mode inductor is electrically connected to the input terminal 31 of the second power board, and the output terminal of the common-mode inductor is electrically connected to the input terminal of the differential-mode inductor. The output terminal of the differential-mode inductor is electrically connected to the output terminal 32 of the second power board, further filtering both common-mode and differential-mode signals in the AC power supply. In these embodiments, the stability of the AC power supply is further improved by using a differential-mode inductor or a common-mode inductor.
[0051] In some embodiments, the inverter 100 further includes a first switch, the output terminal of which is connected to the output terminal of the inverter circuit 210 and the output terminal 23 of the first power board. The first switch is used to control the disconnection or connection of the AC power output by the inverter circuit 210. By setting the first switch, signals or power supplies between different circuits can be effectively isolated, preventing a problem in one circuit from affecting another, which is beneficial to improving the stability and safety of the inverter circuit.
[0052] This application also provides a wind power generation system, such as... Figure 8 As shown, the inverter of this embodiment can be applied to the wind power generation system, which includes a wind turbine, a rectifier, and an inverter. The inverter is used to convert direct current (DC) from the wind turbine into alternating current (AC) and transmit it to the power grid.
[0053] This application also provides an energy storage grid-connected power generation system, such as... Figure 9 As shown, the inverter in this embodiment can be applied to the energy storage grid-connected power generation system, which consists of an energy storage system, an inverter, and an AC power grid. In this energy storage grid-connected power generation system, the inverter converts the DC power output from the energy storage system into AC power and transmits the converted AC power to the AC power grid.
[0054] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An inverter, characterized by, The inverter circuit, the first filter circuit, the second filter circuit and the third filter circuit are included. The first filter circuit is electrically connected with a direct current input end of the inverter circuit. The second filter circuit includes one or more inverter inductors, which are electrically connected between the inverter circuit and the first filter circuit, and are electrically connected between the inverter circuit and the third filter circuit. The third filter circuit is electrically connected with the inverter inductor, and is further used for electrically connecting a power grid or a load. The inverter circuit is used for converting direct current into alternating current and transmitting the alternating current to the inverter inductor, the inverter inductor is used for filtering the alternating current and transmitting a part of the filtered alternating current to the first filter circuit, the first filter circuit further filters a part of the alternating current, and transmits a part of the further filtered alternating current to the direct current input end of the inverter circuit. The inverter inductor is used for filtering the alternating current and transmitting another part of the filtered alternating current to the third filter circuit, and the third filter circuit further filters another part of the alternating current, and outputs another part of the further filtered alternating current to the power grid or the load. Impedance of an electric connection line between the inverter inductor and the direct current input end of the inverter circuit to a high-frequency ripple current is smaller than impedance of an electric connection line between the inverter inductor and an output end of the third filter circuit to the high-frequency ripple current, and the high-frequency ripple current has a frequency greater than a power frequency.
2. The inverter of claim 1, wherein, The inverter inductor is electrically connected with the first filter circuit at least partially through a first wire, and is electrically connected with the third filter circuit at least partially through a second wire, wherein a diameter of the first wire is smaller than a diameter of the second wire.
3. The inverter of claim 1, wherein, The inverter inductor includes a coil, a magnetic core and a packaging body, the coil is wound on the magnetic core, and the coil and the magnetic core are arranged in the packaging body.
4. The inverter of claim 1, wherein, The first filter circuit includes a capacitor.
5. The inverter according to any one of claims 1 to 4, characterized by, The third filter circuit includes a differential mode inductor, which is used for filtering a differential mode signal in another part of the alternating current filtered by the inverter inductor.
6. The inverter of any one of claims 1 to 4, wherein, The third filter circuit includes a common mode inductor, which is used for filtering a common mode signal in another part of the alternating current filtered by the inverter inductor.