Search

KR-102962831-B1 - Switching loss balancing circuit

KR102962831B1KR 102962831 B1KR102962831 B1KR 102962831B1KR-102962831-B1

Abstract

A balancing circuit according to one embodiment of the present invention includes a first resistor of a voltage sensing unit connected to a first terminal of an output terminal of a power converter and a second resistor connected to the same node as a third resistor of a voltage sensing unit connected to a second terminal of an output terminal of the power converter, and the second resistor and the fourth resistor are connected to an upper switch of the power converter.

Inventors

  • 윤동근
  • 공성재
  • 최상규

Assignees

  • 엘지이노텍 주식회사

Dates

Publication Date
20260511
Application Date
20210702

Claims (10)

  1. A second resistor, one end of which is connected to the same node as the first resistor of the voltage sensing unit connected to the first terminal of the output terminal of the power converter; and It includes a fourth resistor, one end of which is connected to the same node as the third resistor of the voltage sensing unit connected to the second terminal of the output terminal of the power converter, and The above power converter is, A first upper switch and a first lower switch connected in series with one end of the first upper switch; A second upper switch and a second lower switch connected in series with one end of the second upper switch; A first switch and a second switch connected in series between a first node between the first upper switch and the second lower switch and a second node between the second upper switch and the second lower switch; and It includes a diode connected between a third node connecting the other end of the first upper switch and the other end of the second upper switch, and a fourth node connecting between the first switch and the second switch. The first terminal of the output terminal of the power converter is a terminal connected to the second node, and The second terminal of the output terminal of the power converter is a terminal connected to the first node, and The other end of the second resistor and the other end of the fourth resistor are connected to the third node of the power converter, and The above voltage sensing unit is a balancing circuit connected to the same ground as the power converter.
  2. In paragraph 1, A balancing circuit in which the difference between the sum of the switching losses of the first upper switch and the second upper switch and the sum of the switching losses of the first lower switch and the second lower switch is within a predetermined range.
  3. In paragraph 1, The above power converter is, A balancing circuit that is an inverter operating at multiple levels according to the operation of the first upper switch, the second upper switch, the first lower switch, and the second lower switch.
  4. In paragraph 1, The values of the first resistor and the second resistor are the same, The values of the third resistor and the fourth resistor are the same in the balancing circuit.
  5. delete
  6. delete
  7. A switching unit including an upper switch and a lower switch; An output unit that outputs a multi-level voltage according to the operation of the above-mentioned switching unit; A voltage sensing unit that senses an output voltage by being connected to the first terminal and the second terminal of the output unit through a first resistor and a third resistor, respectively; A second resistor having one end connected to one end of the first resistor; and It includes a fourth resistor, one end of which is connected to one end of the third resistor, and The above switching unit is, A first upper switch and a first lower switch connected in series with one end of the first upper switch; A second upper switch and a second lower switch connected in series with one end of the second upper switch; A first switch and a second switch connected in series between a first node between the first upper switch and the second lower switch and a second node between the second upper switch and the second lower switch; and It includes a diode connected between a third node connecting the other end of the first upper switch and the other end of the second upper switch, and a fourth node connecting between the first switch and the second switch. The first terminal of the above output unit is a terminal connected to the second node, and The second terminal of the output section is a terminal connected to the first node, and The second resistor and the fourth resistor are connected to a plurality of upper switches, and The above voltage sensing unit is a power converter connected to the same ground as the lower switch.
  8. In Paragraph 7, A power converter in which the difference between the sum of the switching losses of the first upper switch and the second upper switch and the sum of the switching losses of the first lower switch and the second lower switch is within a predetermined range.
  9. In Paragraph 7, The values of the first resistor and the second resistor are the same, The power converter in which the values of the third resistor and the fourth resistor are the same.
  10. delete

Description

Switching loss balancing circuit The present invention relates to a balancing circuit and a power conversion device, and more specifically, to a balancing circuit and a power conversion device that balances the switching losses of a multi-level inverter. Solar power generation is an eco-friendly energy method that is becoming widely adopted as a replacement for conventional chemical or nuclear power generation. Solar power generation systems include standalone types, where batteries are connected to a converter, and grid-connected types, where they are linked to the power grid. Generally, standalone systems consist of solar cells, storage batteries, and power converters, while grid-connected systems are configured to connect to commercial power sources to exchange power with load grid lines. The power generated by photovoltaic (PV) power generation is transmitted to the grid, which is the power system, through an inverter. As shown in Fig. 1, the inverter converts the power to match the voltage of the power output from the photovoltaic panel with the voltage of the grid, and transmits it to the grid through a filter. At this time, when the inverter is in freewheeling switching mode, the (-) node of the DC-link is floating relative to the grid power, so the Vds voltage of each switch (S1, S2, S3, S4) is determined by the difference in impedance between the upper and lower sides. As the impedance of the lower side is reduced by the differential amplifier added for AC voltage sensing at the output terminal, the Vds voltage of switches (S1, S3) becomes the DC-link voltage and the Vds voltage of switches (S2, S4) is lowered to the 0V level. Since the Vds voltage of S1 and S3 is large, switching losses are concentrated on S1 and S3, causing the upper switches to generate more heat, which results in a problem where the operating temperature condition is limited under the same switching loss conditions. FIG. 1 illustrates an inverter according to a comparative embodiment of the present invention. FIG. 2 is a block diagram of a balancing circuit according to one embodiment of the present invention. FIGS. 3 to 5 are drawings for explaining a balancing circuit according to an embodiment of the present invention. FIG. 6 is a block diagram of a power conversion device according to one embodiment of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted. In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology. Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C. In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are used merely to distinguish the components from other components and are not intended to limit the essence, order, or sequence of the components. And, where it is stated that a component is 'connected', 'combined', or 'connected' to another component, this may include not only cases where the component is directly 'connected', 'combined', or 'connected' to the other component, but also cases where it is 'connected', 'combined', or 'connected' due to another component located between the component and the other component. Furthermore, when described as being formed or placed "above" or "below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above" or "below," it may include the meaning of a downward direction as well as an upward direction relative to a single component. FIG. 2 is a block diagram of a balancing circuit according to one embodiment of the present invention. A balancing circuit (100) according