Search

EP-4465513-B1 - MAGNETIC INTEGRATED INDUCTOR AND INVERTER

EP4465513B1EP 4465513 B1EP4465513 B1EP 4465513B1EP-4465513-B1

Inventors

  • WANG, TAO
  • DONG, Kehong
  • HU, WENHAO
  • YI, DEGANG

Dates

Publication Date
20260506
Application Date
20230919

Claims (7)

  1. An inverter circuit comprising a three-phase bridge arm module, a bus capacitor module (C p , C n ), an output filter module (L 1 , L 2 , L 3 , C 1 , C 2 , C 3 ), and for each phase a respective signal processing circuit and a respective magnetic integrated inductor, said three-phase bridge arm module comprising three one-phase bridge arms, each consisting of parallelconnected first and second bridge arms (R1, R2, S1, S2, T1, T2), the three-phase bridge arm module being connected to the bus capacitor module and each of the magnetic integrated inductors, each of the magnetic integrated inductors being also connected to the output filter module and serving for connection with the signal processing circuit, the bus capacitor module being used for DC input, and the output filter module being used for AC output; each of the magnetic integrated inductors being configured to suppress common-mode current ripple and differential-mode current ripple when the inverter converts DC to AC, and is adapted to measure the current difference between the first bridge arm and the second bridge arm in each one-phase bridge arm of the three-phase bridge arm module; wherein each of the magnetic integrated inductors comprises: a first winding (N1), a second winding (N2), a third winding (N3), a central column magnetic core (C4), an upper magnetic core (C3), a lower magnetic core (C5), a left column magnetic core (C1) and a right column magnetic core (C2); the upper magnetic core and the lower magnetic core being symmetrically arranged up and down; the central column magnetic core, the left column magnetic core and the right column magnetic core all being vertically arranged with respect to the upper magnetic core and the lower magnetic core; the upper magnetic core, the lower magnetic core, the left column magnetic core and the right column magnetic core are all made of a first type of material, and the central column magnetic core is made of a second type of material; and the magnetic permeability of the first type of material is lower than that of the second type of material; the first winding being wound on the left column magnetic core, the second winding being wound on the right column magnetic core, and the third winding being wound on the central column magnetic core; wherein an input terminal (L1) of the first winding is connected with the output terminal of the first bridge arm, an input terminal (L3) of the second winding is connected with the output terminal of the second bridge arm, an output terminal of the first winding (L2) and an output terminal (L4) of the second winding are both connected to the output filter module; the first winding having the same number of turns as the second winding; wherein an input terminal (L5) and an output terminal (L6) of the third winding are respectively connected with the respective signal processing circuit; wherein, the third winding is configured to obtain the magnetic flux of the first winding and the magnetic flux of the second winding in order for the signal processing circuit to calculate the induced voltage of the third winding and to integrate it thereby obtaining the center column magnetic flux, and based on the center column magnetic flux, to calculate the current difference between the first winding and the second winding.
  2. The inverter circuit according to Claim 1, wherein in each of the magnetic integrated inductors the left column magnetic core has the same shape as the right column magnetic core, and the first winding has the same number of turns as the second winding.
  3. The inverter circuit according to Claim 1, wherein in each of the magnetic integrated inductors the first type of material is one of iron silicon, iron silicon aluminum and iron nickel or a combination thereof; and the second type of material is one of ferrite, amorphous substance and nanocrystalline or a combination thereof.
  4. The inverter circuit according to any of Claims 1 to 3, wherein in each of the magnetic integrated inductors the tops of the central column magnetic core, the left column magnetic core and the right column magnetic core are all flush with the bottom of the upper magnetic core, and the bottoms of the central column magnetic core, the left column magnetic core and the right column magnetic core are all flush with the top of the lower magnetic core.
  5. The inverter circuit according to any of Claims 1 to 3, wherein in each of the magnetic integrated inductors the upper magnetic core comprises two parts, and the two parts of the upper magnetic core are symmetrically arranged left and right with respect to the central column magnetic core; the top of the central column magnetic core is flush with the top of the upper magnetic core, and the bottom of the central column magnetic core is flush with the top of the lower magnetic core; both the tops of the left column magnetic core and the right column magnetic core are flush with the bottom of the upper magnetic core, and both the bottoms of the left column magnetic core and the right column magnetic core are flush with the top of the lower magnetic core.
  6. The inverter circuit according to any of Claims 1 to 3, wherein in each of the magnetic integrated inductors each of the upper magnetic core and the lower magnetic core comprises two parts, wherein the two parts of the upper magnetic core are symmetrically arranged left and right with respect to the central column magnetic core, and the two parts of the lower magnetic core are symmetrically arranged left and right with respect to the central column magnetic core; the top of the central column magnetic core is flush with the top of the upper magnetic core, the bottom of the central column magnetic core is flush with the bottom of the lower magnetic core; both the tops of the left column magnetic core and the right column magnetic core are flush with the bottom of the upper magnetic core, and both the bottoms of the left column magnetic core and the right column magnetic core are flush with the top of the lower magnetic core.
  7. An inverter comprising: an inverter circuit according to any of Claims 1 to 6.

Description

Technical Field The present application relates to the technical field of power electronics, and in particular, relates to an inverter circuit. Background of the Invention In the fields of photovoltaic power generation, electrochemical energy storage or the like, requirements for power of grid-connected inverters are increasing gradually, but the existing single-tube devices cannot meet the requirements of high power, so it is necessary to use power modules. However, the price of the power modules is high, which increases the system cost. Therefore, single-tube devices are usually used to build inverter bridge arms, and then multiple inverter bridge arms are connected in parallel for use. However, this will increase the number of inductors and current sensors, and thus increase the cost and complexity of the system. US2008/080106 discloses an integrated DC link inductor and current sensor winding having a core that includes at least two primary legs and at least one secondary leg, two direct current (DC) link windings each wound around one of the two primary legs, and a common mode current sensor winding wound around the secondary leg. Resistors coupled to the common mode current sensor winding may damp the common mode current oscillations. CN107196547 discloses a three-phase dual buck grid inverter which has double buck bridge arm composed of positive buck unit and negative buck unit, and each phase composed of two comparators output, positive and negative buck units and two driving signals. CN204188695U discloses a High voltage unbalanced electric current detecting transformer has preset secondary winding and specific secondary winding that are electrically connected with low voltage end of alternate/direct current high voltage filter capacitor. CN105024571 discloses a three-phase inverter circuit which has transformer whose primary winding is connected with alternating current output connection terminal, where secondary winding of transformer is connected with three-phase filter capacitor unit output end. Summary of the Invention The technical problem mainly to be solved by embodiments of the present application is to provide a magnetic integrated inductor and an inverter, which can effectively reduce the current ripple, reduce the volume of the whole circuit and reduce the cost. In order to solve the above technical problem, a technical solution adopted by an embodiment of the present application is to provide an inverter circuit according to claim 1. Further embodiments are defined by the dependent claims. The magnetic integrated inductor provided according to the embodiments of the present application can perform differential-mode current sampling while suppressing differential-mode current ripple and common-mode current ripple, thereby reducing the volume of the circuit and reducing the cost. Brief description of the Drawings One or more embodiments are exemplarily described with reference to pictures in corresponding attached drawings, and these exemplary descriptions are not intended to limit the embodiments. In the attached drawings, elements with the same reference numerals represent the similar elements, and unless otherwise stated, the pictures in the attached drawings are not intended to limit the scale. FIG. 1 is a schematic structural diagram of a three-phase bridge arm parallel inverter circuit.FIG. 2 is a schematic structural diagram of a magnetic integrated inductor provided according to an embodiment of the present application.FIG. 3 is a schematic structural diagram of an inverter provided according to an embodiment of the present application.FIG. 4 is a schematic structural diagram when the magnetic integrated inductor provided according to the embodiment of the present application is in operation.FIG. 5 is a schematic structural diagram of five kinds of structures of one bridge arm in the inverter.FIG. 6 is a schematic structural diagram of another magnetic integrated inductor provided according to an embodiment of the present application.FIG. 7 is a schematic structural diagram of yet another magnetic integrated inductor provided according to an embodiment of the present application. Detailed Description of Embodiments In order to make objectives, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the attached drawings and embodiments. It shall be appreciated that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application. It shall be noted that, various features in the embodiment of the present application may be combined with each other if there is no conflict therebetween. In addition, although functional modules are divided in the schematic diagram of the device and the logical order is shown in the flowchart diagram, in some cases, the steps shown or described may be executed in a module divisi