KR100986183B1 - Device for converting dc/dc - Google Patents

Abstract

The present invention relates to a DC / DC converter.

An embodiment of the present invention includes a resonator including an input inductor, a resonant inductor connected to the input inductor, a first resonant capacitor connected to the input inductor, and a second resonant capacitor connected to the resonant inductor. A first switching element including a first switching element connected to the first switching element, and a first reverse diode connected in parallel to the first switching element in parallel to the first switching element, and a first diode connected between the first resonant capacitor and the first switching element. And a second diode connected between the first resonant capacitor and the resonant inductor, a second switching device connected to the first resonant capacitor, and a second reverse diode connected in parallel to the second switching device in a reverse direction. And a smoothing capacitor connected to the second switching unit and the second switching element.

DC / DC, soft switching, three phase

Description

DC / DC converters {DEVICE FOR CONVERTING DC / DC}

The present invention relates to a DC / DC converter.

In general, the DC / DC converter adjusts the level of the DC voltage, and a representative DC / DC converter includes a booster converter.

The booster converter accepts a small DC voltage and boosts it to a higher voltage level to provide the output voltage.

Such booster converters are used in power conditioning systems (PCS) of solar power generation.

However, the above-mentioned booster converter includes a switching element, and there is a problem that power loss occurs during turn-on and turn-off of the switching element, and electromagnetic interference (EMI) noise is caused.

The DC / DC converter according to the embodiment of the present invention can effectively reduce power loss and electromagnetic interference (EMI) noise.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above are provided to those skilled in the art (hereinafter, those skilled in the art) from the following description. It will be clearly understood.

According to an embodiment of the present invention, a DC / DC converter includes an input inductor, a resonant inductor connected to the input inductor, a first resonant capacitor connected to the input inductor, and a second resonant capacitor connected to the resonant inductor. A first switching unit including a resonator, a first switching element connected to the resonant inductor, and a first reverse diode connected in parallel to the first switching element in parallel with the first switching element; A first diode connected between the elements, a second diode connected between the first resonant capacitor and the resonant inductor, a second switching element connected to the first resonant capacitor, and a reverse connection in parallel to the second switching element A second switching unit including a second reverse diode and a smooth capacitance connected to the second switching element It includes.

According to the embodiments of the present invention, since all switching elements are soft switched, power loss and electromagnetic interference (EMI) noise may be effectively reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

1 is a circuit diagram of a DC / DC converter according to a first embodiment of the present invention, FIG. 2 is a circuit diagram of a DC / DC converter according to a second embodiment of the present invention, and FIG. 3 is FIGS. 1 and 2. 4 is a signal waveform diagram of the circuit diagram of FIG. 3, and FIGS. 5A to 5I are circuit diagrams showing the flow of current for each operation mode.

In the DC / DC converter according to the first embodiment of the present invention, the input inductor L, the resonator 300, the first switching unit 100, and the first diode D10 are illustrated in FIG. 1. , A second diode D20, a second switching unit 200, and a smoothing capacitor Co.

An input voltage Vin is applied to the input inductor L, and the resonator 300 is connected to a resonant inductor Lr connected to the input inductor L and a second switching element S2 to be described later. A first resonant capacitor Cr1 and a second resonant capacitor Cr2 are connected to the resonant inductor Lr.

In addition, the first switching unit 100 includes a first switching element S1 connected to the resonant inductor Lr and a first reverse diode D1 connected in parallel to the first switching element S1 in parallel. .

Here, the first switching element S1 may be configured as an Insulated Gate Bipolar Transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOS FET), and the first reverse diode D1 may be a first switching element. When (S1) is an IGBT, a separate diode is connected in parallel to the first switching element S1 in a reverse direction as shown in FIG. 1, and when the first switching element S1 is a MOS transistor, a body parasitic to the MOS transistor. Diodes can be used.

Meanwhile, the first diode D10 is connected between the second resonant capacitor Cr2 and the first switching element S1, and the second diode D20 is connected to the first resonant capacitor Cr1 and the second resonant capacitor Cr2. ) And a resonant inductor Lr.

In addition, the second switching unit 200 may include a second switching element S2 connected to the first resonant capacitor Cr1 and a second reverse diode D2 connected in parallel to the second switching element S2 in a reverse direction. The smoothing capacitor Co is connected to the second switching element S2.

Here, the second switching element S2 may be composed of an Insulated Gate Bipolar Transistor (IGBT) or a Metal Oxide Semiconductor Field Effect Transistor (MOS FET), and the second reverse diode D2 is the second switching element. When (S2) is an IGBT, a separate diode is connected in parallel to the second switching element (S2) in a reverse direction as shown in FIG. Diodes can be used.

The first embodiment includes a single phase inverter 1100 including inverter switching elements S11, S12, S13, S14 and reverse diodes D11, D12, D13, D14, an inductor Lf and a capacitor Cf. The output filter 1200 is connected.

The second embodiment will be described with respect to the difference from the first embodiment.

The second embodiment includes a three-phase inverter 2100 including inverter switching elements S21, S22, S23, S24, S25, and S26, reverse diodes D21, D22, D23, D24, D25, and D26, and an inductor. An output filter 2200 including La, Lb, Lc and capacitors Ca, Cb, Cc is connected.

As shown in FIG. 3, the first and second embodiments may be equivalent to include an inverter switching element Sinv, a reverse diode DINv, and a current source Io.

Specific operations will be described with reference to FIGS. 4 and 5A to 5I.

In mode 1, the first switching element S1 is turned on under a zero current condition to form a current path as shown in FIG. 5A, and the current iLr of the resonant inductor Lr increases linearly.

In mode 2, the current iL of the resonant inductor Lr and the current iLr of the input inductor L are equal, and a current path as shown in FIG. 5B is formed, and the resonant inductor Lr and the first resonance are formed. The capacitor Cr1 resonates so that the voltage Vcr1 of the first resonant capacitor Cr1 is reduced to zero at the output voltage Vo.

In mode 3, the current iL of the input inductor L linearly rises, a current path as shown in FIG. 5C is formed, and the current iLr of the resonant inductor Lr is the first diode D10. And a reflux through the second diode D20, and the inverter switching element Sinv is turned on under a zero voltage condition.

In mode 4, the first switching element S1 is turned off, a current path as shown in FIG. 5D is formed, and the resonant inductor Lr and the second resonant capacitor Cr2 resonate. The voltage Vcr2 of the second resonant capacitor Cr2 is increased to the peak.

In the mode 5, when the direction of the current iLr of the resonant inductor Lr is changed, the resonance is performed as shown in FIG. 5E. The first diode D10, the second resonant capacitor Cr2, the resonant inductor Lr, and the inverter switching element are shown in FIG. Proceed to the path of (Sinv). The voltage Vcr2 of the second resonant capacitor Cr2 is reduced to zero.

In mode 6, the first reverse diode D1 is turned on, a current path as shown in FIG. 5F is formed, and the current of the resonant inductor Lr is the first reverse diode D1, the resonant inductor Lr, and the inverter. It is refluxed in the path of the switching element Sinv.

In mode 7, a current path as shown in FIG. 5G is formed, and the voltage of the inverter switching element Sinv rises from zero to the output voltage Vo.

In mode 8, a current path as shown in FIG. 5H is formed. When the voltage Vcr1 of the first resonant capacitor Cr1 is equal to the output voltage Vo, current flows through the second reverse diode D2 and resonates. The current iLr of the inductor Lr decreases linearly. The second switching element S2 is turned on under the zero voltage condition.

In mode 0, a current path as shown in FIG. 5I is formed and energy is transferred to the load.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Rather, it will be apparent to those skilled in the art that many changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims.

Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

1 is a circuit diagram of a DC / DC converter according to a first embodiment of the present invention.

2 is a circuit diagram of a DC / DC converter according to a second embodiment of the present invention.

3 is a common equivalent circuit diagram of FIGS. 1 and 2.

4 is a signal waveform diagram of the circuit diagram of FIG.

5A-5I are circuit diagrams showing the flow of current for each mode of operation.

<Description of Signs of Major Parts of Drawings>

100: first switching unit

200: second switching unit

300: resonator

Claims (7)

Input inductor; A resonator including a resonant inductor connected to the input inductor, a first resonant capacitor connected to the input inductor, and a second resonant capacitor connected to the resonant inductor; A first switching unit including a first switching element connected to the resonant inductor and a first reverse diode connected in parallel to the first switching element in parallel; A first diode connected between the first resonant capacitor and the first switching element; A second diode connected between the first resonant capacitor and the resonant inductor; A second switching unit including a second switching element connected to the first resonant capacitor and a second reverse diode connected in parallel to the second switching element in parallel; And DC / DC converter comprising a smoothing capacitor connected to the second switching element. The method of claim 1, The first switching element is an Insulated Gate Bipolar Transistor (IGBT). The method of claim 1,  The first switching device is a metal oxide semiconductor field effect transistor (MOS FET) DC / DC converter. The method of claim 3, And the first reverse diode is a body diode parasitic in the MOS transistor. The method of claim 1, The second switching device is an Insulated Gate Bipolar Transistor (IGBT). The method of claim 1,  The second switching device is a metal oxide semiconductor field effect transistor (MOS FET) DC / DC converter. The method of claim 6, And the second reverse diode is a body diode parasitic to the MOS transistor.

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