TWI459705B - Single - stage high - boost ratio DC - DC converter - Google Patents

Description

Single-stage high step-up ratio DC-DC converter

The present invention relates to a power converter, and more particularly to a single-stage high step-up ratio DC-DC converter.

According to environmental pollution and global warming effect, the issue of energy conservation and carbon reduction has been paid more and more attention. The application of green energy has become the focus of research and development in various countries. The electric energy generated by solar cells, fuel cells and wind power generators is a variable DC. Or AC low voltage, so it is necessary to boost the low voltage to a high voltage through a boost converter to the DC bus, and then convert it to the required AC voltage through the converter, and the conventional boost DC-DC The converter [as shown in Figure 7] theoretically yields a very high voltage gain as shown below: D is the duty cycle. In fact, due to factors such as the on-resistance of the switch, the forward voltage drop of the diode, the equivalent series resistance of the inductor and the capacitor, the converter cannot obtain a higher voltage-gain ratio. That is, the conversion efficiency of the converter is poor, and therefore, the inventors have devoted themselves to research and developed a single-stage high step-up ratio DC-DC converter.

The invention provides a single-stage high step-up ratio DC-DC converter, which comprises: The primary circuit includes an input voltage terminal, a first inductor, a first diode, a second diode, a primary side inductor, a first capacitor, a switch, and a first output. a diode and a first output capacitor, wherein one end of the first inductor is connected to one end of the input voltage terminal, and the other end of the first inductor is connected to the anode end of the first diode and connected to the anode of the second diode Extremely, the cathode end of the first diode is connected to one end of the primary side inductor to form a first node, and the cathode end of the second diode is connected to the other end of the primary side inductor to form a second node, the first node Connecting one end of the switch and an anode end of the first output diode, and the second node is connected to one end of the first capacitor, and the cathode end of the first output diode is connected to one end of the first output capacitor and forming a a third node, wherein the other end of the input voltage terminal, the other end of the first capacitor, the other end of the switch, and the other end of the first output capacitor are electrically connected to each other; and a secondary circuit, the secondary circuit is electrically connected to the foregoing Primary side circuit; A load side terminal of the output load line is electrically connected to the primary side circuit and a secondary side circuit.

Further, the secondary circuit includes a secondary side inductor, a second output diode, a third output diode, a second output capacitor, and a third output capacitor, wherein the second output capacitor has one end Connecting one end of the third output capacitor and one end of the second side inductor, and the other end of the second output capacitor is connected to the third node and the anode end of the second output diode, and the other end of the second side inductor is opposite to the first end The cathode end of the second output diode is connected to the anode end of the third output diode, and the cathode end of the third output diode is connected to the other end of the third output capacitor.

Further, the secondary circuit includes the secondary side inductor, the second output diode, the second output capacitor, a second capacitor, a third capacitor, and a second a diode body and a fourth diode, wherein one end of the secondary side inductor is connected to the anode end of the fourth diode and one end of the third capacitor, and the cathode end of the fourth diode is connected to the second One end of the capacitor and the anode end of the third diode, and the other end of the third capacitor is connected to the cathode end of the third diode and then connected to the anode end of the second output diode, the second output diode The cathode end of the body is connected to one end of the second output capacitor, and the other end of the second side inductor is electrically connected to the other end of the second capacitor and the other end of the second output capacitor.

Further, the primary side inductance and the secondary side inductance are coupled inductors.

The invention has the advantages that: 1. The invention can appropriately adjust the coil turns ratio of the primary side inductance and the secondary side inductance to be N ₂ /N ₁ , thereby obtaining a higher voltage gain ratio than the conventional one.

(1) ‧‧‧primary circuit

(2) ‧‧‧secondary circuit

(3)‧‧‧ Output load end

(S ₁ )‧‧‧Switch

(V _in )‧‧‧Input voltage terminal

(L ₁ )‧‧‧First inductance

(L _m )‧‧‧Magnetic inductance

(N ₁ )‧‧‧ primary side inductance

(N ₂ )‧‧‧secondary inductance

(ND ₁ ) ‧‧‧first node

(ND ₂ )‧‧‧second node

(ND ₃ ) ‧‧‧ third node

(D ₁ )‧‧‧First Diode

(D ₂ )‧‧‧Secondary

(D ₃ )‧‧‧ Third Dipole

(D ₄ )‧‧‧Fourth diode

(D _o1 )‧‧‧First output diode

(D _o2 )‧‧‧Second output diode

(D _o3 )‧‧‧ Third output diode

(C ₁ )‧‧‧First Capacitor

(C ₂ )‧‧‧second capacitance

(C ₃ )‧‧‧ third capacitor

(C _o1 )‧‧‧First output capacitor

(C _o2 )‧‧‧second output capacitor

(C _o3 )‧‧‧ Third Output Capacitor

(R)‧‧‧Load resistor

(L)‧‧‧Inductance

(S)‧‧‧Toggle switch

(D _o )‧‧‧ Output diodes

(C)‧‧‧ Capacitance

(V _o )‧‧‧ output voltage

(M) ‧ ‧ voltage gain ratio

(D) ‧ ‧ responsibility cycle

The first figure is a circuit diagram of a first embodiment of the present invention.

The second A diagram is a current path diagram of mode 1 of the first embodiment of the present invention.

The second B diagram is a current path diagram of mode 1 of the first embodiment of the present invention, illustrating the current path on each element when the switching switch (S ₁ ) is turned on.

The third A diagram is a current path diagram of mode 2 of the first embodiment of the present invention.

The third B diagram is a current path diagram of mode 2 of the first embodiment of the present invention, illustrating the current path on each element when the switching switch (S ₁ ) is turned off.

The fourth figure is a circuit diagram of a second embodiment of the present invention.

Figure 5A is a current path diagram of mode 1 of the second embodiment of the present invention.

FIG fifth B embodiment of the system mode of the second embodiment of the present invention, the current path of FIG. 1, a switch when (S ₁₎ on the respective current paths when the element is turned on.

Figure 6A is a current path diagram of mode 2 of the second embodiment of the present invention.

The sixth mode of the second line B in FIG embodiment of the present invention a current path of FIG. 2, when the switch described (S ₁₎ on the respective current paths when the element is turned off.

The seventh diagram is a circuit diagram of a conventional step-up DC-DC converter.

The eighth graph is a graph showing the voltage gain ratios of the converter 1, the converter 2 of the second embodiment, and the conventional converter of the first embodiment of the present invention.

The present invention is a single-stage high-boost DC-DC converter, as shown in the first figure, in accordance with the preferred embodiment of the present invention. The first embodiment of the present invention, that is, the converter 1 includes a primary side circuit (1), a secondary side circuit (2), and an output load end (3), wherein the primary side The circuit (1) includes an input voltage terminal (V _in ), a first inductor (L ₁ ), a first diode (D ₁ ), a second diode (D ₂ ), and a primary side inductor. (N ₁ ), a first capacitor (C ₁ ), a switch (S ₁ ), a first output diode (D _o1 ), and a first output capacitor (C _o1 ), wherein the first inductor ( One end of the L ₁ ) is connected to one end of the input voltage terminal (V _in ), and the other end of the first inductor (L ₁ ) is connected to the anode end of the first diode (D ₁ ) and is connected to the second diode (D ₂ ) an anode end, a cathode end of the first diode (D ₁ ) is connected to one end of the primary side inductance (N ₁ ) to form a first node (ND ₁ ), and the second diode (D ₂ ) The cathode end is connected to the other side of the primary side inductor (N ₁ ) Forming a second node (ND ₂ ), the first node (ND ₁ ) connecting one end of the switch (S ₁ ) and an anode end of the first output diode (D _o1 ), the second node (ND _{2 )} Connected to one end of the first capacitor (C ₁ ), and the cathode end of the first output diode (D _o1 ) is connected to one end of the first output capacitor (C _o1 ) and forms a third node (ND ₃ ), and The other end of the input voltage terminal (V _in ), the other end of the first capacitor (C ₁ ), the other end of the switch (S ₁ ), and the other end of the first output capacitor (C _o1 ) are electrically connected to each other; and the secondary side The circuit includes a secondary side inductance (N ₂ ), a second output diode (D _o2 ), a third output diode (D _o3 ), a second output capacitor (C _o2 ), and a third output capacitance (C _o3), wherein the second output capacitor (C _o2) having one end connected to the third output capacitor (C _o3) and the end of the secondary side inductor (N ₂₎ at one end, and the second output capacitor (C _o2 The other end is connected to the third node and the anode end of the second output diode (D _o2 ), the other end of the secondary side inductor (N ₂ ) and the cathode end of the second output diode (D _o2 ) connected to the third output diode (D _o3) The male terminal and the female terminal of the third output diode (D _o3) of connecting the third output capacitor (C _o3) and the other end, the load and the output terminal of the load resistor (R) is electrically connected to the primary system side circuit (1) and secondary side circuit (2).

However, the operation mode of the first embodiment of the present invention is as shown in the second A diagram, the second B diagram, and the third A diagram and the third B diagram, which are described as follows:

Mode 1: The switch (S ₁ ) is turned on, and its current path is as shown in the second A diagram and the second B diagram, and the energy of the input voltage terminal (V _in ) is released to the first inductor (L ₁ ), and The first capacitor (C ₁ ) is divided into two paths to release energy, wherein one path releases energy to the magnetizing inductance (L _m ) of the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )] And the other path transmits energy to the secondary side to the third output capacitor (C _o3 ) via the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )], and the An output capacitor (C _o1 ), a second output capacitor (C _o2 ), and a third output capacitor (C _o3 ) supply energy in series to the load resistor (R) at the output load terminal.

Mode 2: the switch (S ₁ ) is turned off, and the current path is as shown in the third A and third B, and the energy of the input voltage terminal (V _in ) and the first inductor (L ₁ ) is released to the a first capacitor (C ₁ ), and a partial energy release of the first capacitor (C ₁ ) and the magnetizing inductance (L _m ) of the coupled inductor [primary side inductor (N ₁ ) and secondary side inductor (N ₂ )] To the first output capacitor (C _o1 ), and a portion of the energy of the magnetizing inductance (L _m ) of the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )] is released via its secondary side to The second output capacitor (C _o2 ), and the first output capacitor (C _o1 ), the second output capacitor (C _o2 ), and the third output capacitor (C _o3 ) supply energy to the load resistor of the output load terminal in series ( R).

Therefore, at steady state, the voltage drop across the first capacitor (C ₁ ), the first output capacitor (C _o1 ), the second output capacitor (C _o2 ), and the third output capacitor (C _o3 ) is as follows:

Where n is the coupled inductor [primary inductance (N ₁ ) and secondary inductance (N ₂ )], the turns ratio is N ₂ /N ₁ , and its output voltage (V _o ) and voltage gain ratio (M) are as follows Show:

Moreover, the circuit diagram of the second embodiment of the present invention is shown in the fourth figure, that is, the converter 2 includes the primary side circuit (1), the secondary side circuit (2), and the output load end (3). The primary side circuit (1) and the output load terminal (3) are the same as the first embodiment, and will not be described here, but the second side circuit (2) includes the aforementioned secondary side inductance. (N ₂ ), the second output diode (D _o2 ), the second output capacitor (C _o2 ), a second capacitor (C ₂ ), a third capacitor (C ₃ ), and a third diode a body (D ₃ ) and a fourth diode (D ₄ ), wherein one end of the secondary side inductor (N ₂ ) is connected to the anode terminal of the fourth diode (D ₄ ) and the third capacitor (C _{3 )} One end, and the cathode end of the fourth diode (D ₄ ) is connected to one end of the second capacitor (C ₂ ) and the anode end of the third diode (D ₃ ), and the third capacitor (C _{3 )} ) and the other end connected to the third diode (D ₃₎ connected to the cathode terminal and the anode terminal and then the second output diode (D _o2), the cathode terminal of the second output diode (D _o2) of the connector the second output capacitor (C _o2) one end of the secondary side inductor (N ₂₎ and the other end The second capacitor (C ₂₎ and the other end of the second output capacitor (C _o2) are electrically connected to the other end.

However, the operation mode of the second embodiment of the present invention is as shown in the fifth A diagram, the fifth B diagram, and the sixth diagram A and the sixth diagram B, which are described as follows:

Mode 1: the switch (S ₁₎ is turned on, the current path as shown in FIG V A and V B in FIG., The voltage input terminal (V _in) of energy release to the first inductor (L _1), and The first capacitor (C ₁ ) is divided into two paths to release energy, wherein one path releases energy to the magnetizing inductance (L _m ) of the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )] And the other path transmits energy to the secondary side and the second capacitor (C ₂ ) in series to the third via the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )] The capacitor (C ₃ ), and the first output capacitor (C _o1 ) and the second output capacitor (C _o2 ) supply energy in series to the load resistor (R) of the output load terminal.

Mode 2: the switch (S ₁ ) is turned off, and the current path thereof is as shown in FIG. 6A and FIG. 6B, and the energy of the input voltage terminal (V _in ) and the first inductor (L ₁ ) is released to the a first capacitor (C _1), and the first capacitor (C ₁₎ and the coupling inductor [primary side inductor (N ₁₎ and a secondary side inductor (N _2)] of the magnetizing inductance (L _m) part of the energy released To the first output capacitor (C _o1 ), and a part of the energy of the magnetizing inductance (L _m ) of the coupled inductor [primary side inductance (N ₁ ) and secondary side inductance (N ₂ )] is via a secondary side thereof The path is released to the second capacitor (C ₂ ), and the other path is released in series with the third capacitor (C ₃ ) to the second output capacitor (C _o2 ), and the first output capacitor (C _o1 ) and the The second output capacitor (C _o2 ) supplies energy in series to the load resistor (R) at the output load terminal.

Therefore, in the steady state, the first capacitor (C ₁ ), the second capacitor (C ₂ ), the third capacitor (C ₃ ), the first output capacitor (C _o1 ), and the second output capacitor (C _o2 ) The voltage drop is as follows:

Its output voltage (V _o ) and voltage gain ratio (M) are as follows:

Further, a graph of the voltage gain ratio (M) of the converter 1 of the first embodiment of the present invention, the converter 2 of the second embodiment, and the conventional conventional boost converter is as shown in the eighth diagram. The axis is the duty cycle (D) and the vertical axis is the voltage gain ratio (M). It can be seen from the figure that the converter 1 of the first embodiment of the present invention and the converter 2 of the second embodiment are conventionally known to have a conventional boost type conversion. The voltage gain of the device is higher than (M).

As described above, the embodiments and drawings of the present invention are set forth in the preferred embodiments of the present invention and are not intended to limit the invention.

In combination with the description of the above embodiments, the operation and use of the present invention can be fully understood. And the effects of the present invention, but the above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the simple scope of the invention and the description of the invention. Modifications and modifications are within the scope of the invention.

(1) ‧‧‧primary circuit

(2) ‧‧‧secondary circuit

(3)‧‧‧ Output load end

(S ₁ )‧‧‧Switch

(V _in )‧‧‧Input voltage terminal

(L ₁ )‧‧‧First inductance

(N ₁ )‧‧‧ primary side inductance

(N ₂ )‧‧‧secondary inductance

(ND ₁ ) ‧‧‧first node

(ND ₂ )‧‧‧second node

(ND ₃ ) ‧‧‧ third node

(D ₁ )‧‧‧First Diode

(D ₂ )‧‧‧Secondary

(D _o1 )‧‧‧First output diode

(D _o2 )‧‧‧Second output diode

(D _o3 )‧‧‧ Third output diode

(C ₁ )‧‧‧First Capacitor

(C _o1 )‧‧‧First output capacitor

(C _o2 )‧‧‧second output capacitor

(C _o3 )‧‧‧ Third Output Capacitor

(R)‧‧‧Load resistor

(V _o )‧‧‧ output voltage

(V _o1 )‧‧‧First output voltage

(V _o2 )‧‧‧second output voltage

(V _o3 )‧‧‧ Third output voltage

Claims (2)

A single-stage high step-up ratio DC-DC converter includes: a primary side circuit including an input voltage terminal, a first inductor, a first diode, a second diode, and a a primary side inductor, a first capacitor, a switch, a first output diode, and a first output capacitor, wherein the first inductor is connected to one end of the input voltage terminal, and the other end of the first inductor is connected to the first inductor An anode end of the first diode is connected to the anode end of the second diode, and a cathode end of the first diode is connected to one end of the primary side inductor to form a first node, and the second diode is negative The other end of the primary side is connected to form a second node, the first node is connected to one end of the switching switch and the anode end of the first output diode, and the second node is connected to one end of the first capacitor, and the first node A cathode end of an output diode is connected to one end of the first output capacitor and forms a third node, and the other end of the input voltage terminal, the other end of the first capacitor, the other end of the switch, and the other end of the first output capacitor are electrically connected to each other. Connection; one secondary side The circuit is electrically connected to the primary side circuit, wherein the secondary circuit includes the secondary side inductor, the second output diode, the second output capacitor, a second capacitor, a third capacitor, and a second capacitor a third diode and a fourth diode, wherein one end of the secondary side inductor is connected to the anode end of the fourth diode and one end of the third capacitor, and the cathode end of the fourth diode is connected to the first One end of the second capacitor and the anode end of the third diode, and the other end of the third capacitor is connected to the cathode end of the third diode and then connected to the anode end of the second output diode, the second output two The cathode end of the pole body is connected to one end of the second output capacitor, and the other end of the second side inductor is electrically connected to the other end of the second capacitor and the other end of the second output capacitor; An output load terminal is electrically connected to the primary side circuit and the secondary side circuit. The single-stage high step-up ratio DC-DC converter according to claim 1, wherein the primary side inductance and the secondary side inductance are coupled inductors.