TWI516005B - DC - DC power conversion device with high step - down ratio - Google Patents

Description

DC-DC power conversion device with high step-down ratio

The invention relates to a DC-DC power conversion device with a high step-down ratio, in particular to a DC-DC power conversion device with a lower voltage conversion ratio.

At present, the DC-DC power conversion device is a circuit diagram of a conventional DC-DC step-down power conversion device, which includes an input voltage terminal (A1), a switch (A2), and a switch. a pole body (A3), an inductor (A4), an output capacitor (A5), and a load (A6), wherein one of the input voltage terminals (A1) is electrically connected to the switch (A2) One end of the switch (A2) is electrically connected to one end of the diode (A3) and one end of the inductor (A4), and the other end of the inductor (A4) is electrically connected to the output. a capacitor (A5) and one end of the load (A6), and one anode end of the diode (A3), the other end of the output capacitor (A5), and the other end of the load (A6) are electrically connected to the input voltage end (A1) one of the negative terminals to form a DC-DC and step-down power conversion device, the voltage conversion ratio M=D, D is the duty cycle, but if operating at a very low duty cycle, it can reach the pole Low step-down ratio function, but will result in poor conversion efficiency.

Further, as shown in FIG. 10, it is a circuit diagram of a quadratic DC-DC step-down power conversion device, which includes an input voltage terminal (B1), a first diode (B2), a second diode (B3), a first inductor (B4), a first capacitor (B5), a switching off (B6), a third diode (B7), and a second inductor (B8) An output capacitor (B9) and a load (B0), wherein one positive terminal of the input voltage terminal (B1) is electrically connected to one of the cathode ends of the first diode (B2) and One end of the first inductor (B4), the other end of the first inductor (B4) is electrically connected to one end of the first capacitor (B5) and one end of the switch (B6), and the first diode (B2) One of the anode ends is electrically connected to the other end of the first capacitor (B5) and one of the cathode ends of the second diode (B3), and the other end of the switch (B6) is electrically connected to the third diode One end of the body (B7) and one end of the second inductor (B8), and the other end of the second inductor (B8) is electrically connected to one end of the output capacitor (B9) and one end of the load (B0), and The other end of the load (B0), the output capacitor (B9) The anode end of one of the third diode (B7) and the anode end of the second diode (B3) are electrically connected to one of the negative terminals of the input voltage terminal (B1) to form a direct current - DC and step-down power conversion device, the voltage conversion ratio M=D ² , D is the duty cycle, although the above-mentioned conventional DC-DC step-down power conversion device can be improved, which can provide a lower step-down ratio, but still There is poor conversion efficiency, and the buck conversion ratio can be studied in a lower direction.

Accordingly, the inventors have continuously innovated and developed, and further proposed a DC-DC power conversion device having a high step-down ratio, comprising: a front half-stage conventional DC-DC step-down power conversion unit, including an input voltage terminal, and a a first diode, a second diode, an input inductor, a first capacitor, and a switch, wherein one of the input voltage terminals is electrically connected to one of the first diodes a cathode end and one end of the input inductor, one anode end of the first diode is electrically connected to one cathode end of the second diode, and the cathode end of the second diode is electrically connected to the first end One end of the capacitor, the other end of the first capacitor is electrically connected to the other end of the input inductor and one end of the switch, and one of the anode ends of the second diode is electrically connected to one of the input voltage terminals a rear half-coupled inductive DC-DC buck power conversion unit, the latter half-level coupling The inductive DC-DC step-down power conversion unit is connected to the first half-stage conventional DC-DC step-down power conversion unit, and includes a third diode, a fourth diode, a coupled inductor, and an output capacitor. An output load, wherein the coupled inductor includes a primary side winding and a secondary side winding, and one end of the primary side winding is electrically connected to one of the cathode ends of the fourth diode and the other end of the switch The other end of the primary side winding is electrically connected to one of the cathode ends of the third diode. The anode end of one of the third diodes is electrically connected to one end of the secondary winding and the negative end of the input voltage terminal. An anode end of the second diode, the cathode end of the third diode is electrically connected to one end of the output capacitor and one end of the output load, and the other end of the output capacitor is connected to the other end of the output load And connecting the anode end of the fourth diode and the other end of the secondary winding.

Wherein, the DC-DC power conversion device with high step-down ratio is operated in a continuous conduction mode, and its voltage conversion ratio is M=D ² /(2-D), where D is a duty cycle.

Further, in a single switching cycle, the switching on relationship is turned on or the switching on relationship is one of the cutoffs.

Wherein, the primary side winding and the secondary side winding have the same number of turns.

Moreover, the present invention is a DC-DC power conversion device with a high step-down ratio, comprising: a front half-stage conventional DC-DC buck power conversion unit; and a second half-stage coupled inductor DC-DC buck power conversion a unit, the latter half-coupled inductive DC-DC step-down power conversion unit is connected to the first half-stage conventional DC-DC step-down power conversion unit; and the latter half-coupled inductive DC-DC step-down power conversion unit comprises A coupled inductor reduces the voltage conversion ratio.

The effect of the invention is:

1. The first half of the power conversion device of the present invention is a conventional DC-DC step-down power conversion device, and the second half is a DC-DC step-down power conversion device with a coupled inductor, which can be integrated with the first half by a switch. The latter half of the DC-DC step-down power conversion circuit.

2. The present invention reduces the voltage conversion ratio by including a coupled inductor in the second half.

3. The invention can achieve the high step-down ratio without operating at a very low duty cycle.

(1) ‧‧‧High-voltage ratio DC-DC power conversion device

(10) ‧‧‧First-class traditional DC-DC step-down power conversion unit

(101)‧‧‧Input voltage terminal

(102)‧‧‧First Diode

(103)‧‧‧Secondary diode

(104)‧‧‧Input inductance

(105)‧‧‧first capacitor

(106)‧‧‧Switch

(11)‧‧‧After half-stage coupled inductive DC-DC step-down power conversion unit

(111)‧‧‧ Third Dipole

(112)‧‧‧Fourth diode

(113)‧‧‧coupled inductor

(1131) ‧‧‧ primary winding

(1132)‧‧‧Secondary winding

(114)‧‧‧ Output capacitance

(115)‧‧‧ Output load

(A1)‧‧‧Input voltage terminal

(A2)‧‧‧Switch

(A3) ‧ ‧ Diodes

(A4)‧‧‧Inductance

(A5)‧‧‧ Output capacitance

(A6) ‧ ‧ load

(B1)‧‧‧Input voltage terminal

(B2) ‧ ‧ first diode

(B3) ‧ ‧ second diode

(B4)‧‧‧First inductance

(B5) ‧‧‧first capacitor

(B6)‧‧‧Toggle switch

(B7)‧‧‧ Third Dipole

(B8)‧‧‧second inductance

(B9)‧‧‧ Output capacitance

(B0) ‧ ‧ load

[First figure] is a circuit diagram of the present invention.

[Second image] is a waveform diagram of the present invention in a single switching cycle.

[Third Figure] is a schematic diagram of the first mode current path for the operation of the present invention.

[Fourth figure] is a schematic diagram of a second mode current path for the operation of the present invention.

[Fifth diagram] is one of the computer simulation waveform diagrams of the present invention.

[Sixth figure] is one of the computer simulation waveform diagrams of the present invention.

[Seventh figure] is one of the computer simulation waveform diagrams of the present invention.

[Eighth image] is one of the computer simulation waveform diagrams of the present invention.

[Ninth Diagram] is a circuit diagram of a conventional conventional DC-DC step-down power conversion device.

[Tenth] is a circuit diagram of a conventional quadratic DC-DC step-down power conversion device.

[11th] is a comparison diagram of voltage conversion ratios between the present invention and a conventional DC-DC step-down power conversion device.

Combining the above technical features, the main effects of the present invention will be clearly shown in the following embodiments.

Please refer to the first figure, the DC-DC power conversion device (1) with high step-down ratio of the present invention includes: a front half-stage conventional DC-DC step-down power conversion unit (10), The first half of the conventional DC-DC step-down power conversion unit (10) includes an input voltage terminal (101), a first diode (102), a second diode (103), and an input inductor (104). a first capacitor (105) and a switch (106), wherein one of the input voltage terminals (101) is electrically connected to one of the cathode ends of the first diode (102) One end of the input inductor (104), one anode end of the first diode (102) is electrically connected to one cathode end of the second diode (103), and the second diode (103) The cathode end is electrically connected to one end of the first capacitor (105), and the other end of the first capacitor (105) is electrically connected to the other end of the input inductor (104) and one end of the switch (106), the first One of the anode ends of the diode (103) is electrically connected to one of the negative ends of the input voltage terminal (101).

A rear half-stage coupled inductive DC-DC step-down power conversion unit (11), the latter half-coupled inductive DC-DC step-down power conversion unit (11) is connected to the first half-stage conventional DC-DC step-down power conversion The unit (10), the latter half-coupled inductive DC-DC step-down power conversion unit (11) includes a third diode (111), a fourth diode (112), and a coupled inductor (113). An output capacitor (114) and an output load (115), wherein the coupled inductor (113) includes a primary side winding (1131) and a secondary side winding (1132), the primary side winding (1131) One end of electricity Optionally, one end of the fourth diode (112) and the other end of the switch (106), the other end of the primary winding (1131) is electrically connected to the third diode (111) a cathode end, one anode end of the third diode (111) is electrically connected to one end of the secondary winding (1132) and the negative end of the input voltage terminal (101) and the second diode (103) The anode end of the third diode (111) is electrically connected to one end of the output capacitor (114) and one end of the output load (115), and the other end of the output capacitor (114) The other end of the output load (115) is connected and connected to the anode end of the fourth diode (112) and the other end of the secondary winding (1132).

Furthermore, please refer to the second figure, which is a waveform diagram mainly for a single switching period, and the present invention operates in a continuous conduction mode.

Furthermore, referring to the third and fourth figures, and in conjunction with the second figure, the present invention uses the pulse width modulation technique to control the duty cycle D of the switch (106), and the present invention operates in In the continuous conduction mode, the voltage conversion ratio is M=D ² /(2-D), and the operation principle is as follows:

(1) Mode 1: In the interval [t0, t1] [as shown in the second figure], when the switch (106) is turned on, the current path is as shown in the third figure, and the input power is transmitted to the input inductor (104). The coupled inductor (113), the output capacitor (114), and the output load (115), and the energy stored in the first capacitor (105) is also transmitted to the coupled inductor (113), the output capacitor (114), and the output load ( 115), and in this interval, the primary side winding (1131) and the secondary side winding (1132) of the coupled inductor (113) store energy in series, and when the switch (106) is turned off, the operation mode ends.

(2) Mode 2: In the interval [t1, t2] [as shown in the second figure], when the switch (106) is turned off, the current path is as shown in the fourth figure, and the energy stored in the input inductor (104) is transmitted. To the first capacitor (105), at the same time, the energy stored in the coupled inductor (113) is also transmitted to the output capacitor (114) and the output load (115). In this interval, the primary winding of the coupled inductor (113) (1131) And the secondary winding (1132) releases energy in parallel. When the switching switch (106) is turned on again, the operation mode ends and the next switching cycle begins.

Furthermore, please refer to the fifth to eighth figures, which are computer simulation waveforms when the input voltage is 200 volts (V), the output voltage is 24 volts (V), and the output power is 200 watts (W). Among them, the waveform value of the fifth figure is: i _Lin /i _D1 : 0.5A / div, i _s1 : 1A / div, Time: 50μs / div; and the waveform value of the sixth figure is: i _L1 / i _L2 : 1A /div,i _LL :2A/div,Time:50μs/div; the waveform value of the seventh figure is: i _D2 /i _D3 /i _D4 :1A/div,Time:50μs/div; the waveform value of the eighth figure is :V _in :50V/div, V _c1 :20V/div, V _o :5V/div, Time:50μs/div, and the DC-DC power conversion device with high step-down ratio of the present invention can be seen from the drawing (1) The function of high step-down ratio can be achieved without operating at a very low duty cycle.

Furthermore, please refer to FIG. 11 , which is a conventional DC-DC step-down power conversion device of the present invention and a conventional one [as shown in FIG. 9], and one of the secondary types of the prior art. The voltage conversion ratio graph of the (quadratic) DC-DC step-down power conversion device [shown in FIG. 10] shows that the present invention has its advantages when a higher step-down conversion ratio is required.

In view of the above description of the embodiments, the operation and use of the present invention and the effects produced by the present invention can be fully understood, but the above embodiments are merely the present invention. The preferred embodiments are to be construed as limiting the scope of the invention and the scope of the invention.

(1) ‧‧‧High-voltage ratio DC-DC power conversion device

(10) ‧‧‧First-class traditional DC-DC step-down power conversion unit

(101)‧‧‧Input voltage terminal

(102)‧‧‧First Diode

(103)‧‧‧Secondary diode

(104)‧‧‧Input inductance

(105)‧‧‧first capacitor

(106)‧‧‧Switch

(11)‧‧‧After half-stage coupled inductive DC-DC step-down power conversion unit

(111)‧‧‧ Third Dipole

(112)‧‧‧Fourth diode

(113)‧‧‧coupled inductor

(1131) ‧‧‧ primary winding

(1132)‧‧‧Secondary winding

(114)‧‧‧ Output capacitance

(115)‧‧‧ Output load

Claims (9)

A DC-DC power conversion device with a high step-down ratio includes: a front half-stage conventional DC-DC step-down power conversion unit, comprising an input voltage terminal, a first diode, and a second diode An input inductor, a first capacitor, and a switch, wherein a positive end of the input voltage terminal is electrically connected to one of the cathode ends of the first diode and one end of the input inductor, One anode end of one diode is electrically connected to one cathode end of the second diode, and a cathode end of the second diode is electrically connected to one end of the first capacitor, and the other end of the first capacitor is electrically The other end of the input inductor and one end of the switch, the anode end of the second diode is electrically connected to one of the input voltage terminals; the second half of the coupled inductor type DC-DC step-down a power conversion unit, the latter half-coupled inductive DC-DC step-down power conversion unit is connected to the first half-stage conventional DC-DC step-down power conversion unit, and includes a third diode, a fourth diode, a coupled inductor, An output capacitor and an output load, wherein the coupled inductor includes a primary side winding and a secondary side winding, and one end of the primary side winding is electrically connected to one of the cathode ends of the fourth diode and the switch is further One end of the first side winding is electrically connected to one of the cathode ends of the third diode, and one anode end of the third diode is electrically connected to one end of the secondary winding and the input voltage end a negative end and an anode end of the second diode, a cathode end of the third diode is electrically connected to one end of the output capacitor and one end of the output load, and the other end of the output capacitor and the output load are One end is connected and connected to the anode end of the fourth diode and the other end of the secondary winding. The DC-DC power conversion device with high step-down ratio according to claim 1, wherein the DC-DC power conversion device with a high step-down ratio is operated in a continuous conduction mode, and the voltage conversion ratio thereof is M = D ² / (2-D), where D is the duty cycle. For example, the DC-DC power conversion device with high step-down ratio according to claim 1 is further claimed that, in a single switching cycle, the switching-on relationship is turned on or the switching-off relationship is one of the cutoffs. The DC-DC power conversion device with high step-down ratio according to claim 1, wherein the primary winding and the secondary winding are the same number of turns. A DC-DC power conversion device with high step-down ratio includes: a front half stage conventional DC-DC step-down power conversion unit; a second half stage coupled inductor type DC-DC step-down power conversion unit, the second half The coupled inductive DC-DC step-down power conversion unit is connected to the first half-stage conventional DC-DC step-down power conversion unit; the latter half-coupled inductive DC-DC step-down power conversion unit includes a coupled inductor to make the voltage The conversion ratio is reduced. The DC-DC power conversion device with a high step-down ratio according to claim 5, wherein the first-stage conventional DC-DC buck power conversion unit comprises an input voltage terminal and a first diode a second diode, an input inductor, a first capacitor, and a switch, wherein one of the input voltage terminals is electrically connected to one of the cathode ends of the first diode One end of the input inductor, one anode end of the first diode is electrically connected to one cathode end of the second diode, and the cathode end of the second diode is electrically connected to one end of the first capacitor, The other end of the first capacitor is electrically connected to the other end of the input inductor and one end of the switch, and one of the anode ends of the second diode is electrically connected to one of the negative ends of the input voltage end, and the second half The stage-coupled inductive DC-DC step-down power conversion unit includes a third diode, a fourth diode, the coupled inductor, an output capacitor, and an output load, wherein the coupled inductor includes a primary winding And a secondary winding One end of the primary winding is electrically connected to one end of the fourth diode and the other end of the switch, and the other end of the primary winding is electrically connected to one of the cathodes of the third diode. One anode end of the third diode is electrically connected to one end of the secondary winding and the negative end of the input voltage terminal and the second An anode end of the diode, the cathode end of the third diode is electrically connected to one end of the output capacitor and one end of the output load, and the other end of the output capacitor is connected to the other end of the output load and connected The anode end of the fourth diode and the other end of the secondary winding. The DC-DC power conversion device with high step-down ratio according to claim 5, wherein the DC-DC power conversion device with a high step-down ratio is operated in a continuous conduction mode. For example, in the DC-DC power conversion device with high step-down ratio according to Item 5 of the patent application, further, in a single switching cycle, the switching-on relationship is turned on or the switching-off relationship is one of the cutoffs. The DC-DC power conversion device with high step-down ratio according to claim 6, wherein the primary side winding and the secondary side winding have the same number of turns.