TW201644165A - High step-up DC power converter - Google Patents

Abstract

The present invention provides a high step-up DC power converter to overcome the circuit switching inefficiency and failure to provide a high step-up ratio when the conventional step-up converter operates at a high duty cycle. The high step-up DC power converter includes an input unit, a high-step-up DC-DC converter circuit and an output unit. The input unit inputs low-voltage DC power to the high-step-up DC-DC converter circuit. The high-step-up DC-DC converter circuit converts a low voltage level of the DC power received from the input unit to a high voltage level. The ratio of the voltage level at the output unit to the voltage level at the input unit is (1+2D)/(1-D), where D is the duty cycle and 0 < D < 1.

Description

High boost ratio DC power converter

The present invention relates to a high step-up ratio DC power converter, in particular to an input unit that inputs a low voltage DC power to a DC-DC converter circuit with a high step-up ratio for conversion to obtain a high voltage. The DC power has a voltage gain of (1+2D)/(1-D), where D is a duty cycle high step-up ratio DC power converter.

Boost Converter is widely used in various electrical appliances. At present, in order to respond to environmental protection, a green energy source such as a solar cell, a wind turbine, or a fuel cell is utilized. The power generated by the green energy source is a low voltage direct current. Therefore, in use, the low-voltage DC power is converted into a high-voltage DC power by a boost-type DC power converter.

First, please refer to the eleventh figure. The system is a conventional DC power converter (A), comprising an input terminal (A1), an inductor (A2), a switch (A3), an output diode (A4), and an output capacitor (A5). And a load (A6). Wherein one end of the input terminal (A1) is electrically connected to one end of the inductor (A2). The other end of the input terminal (A1) is electrically connected to one end of the switch (A3). The other end of the switch (A3) is electrically connected to the other end of the inductor (A2) and the anode end of the output diode (A4). The cathode end of the output diode (A4) is electrically connected to one end of the output capacitor (A5) and one end of the load (A6). The other end of the output capacitor (A5) and the other end of the load (A6) are electrically connected to the other end of the input terminal (A1). The voltage gain ratio is: 1/(1-D), where D is the duty cycle and D is between 0 and 1.

However, under higher duty cycle operation, high conversion ratios cannot be provided due to circuit conversion efficiency issues. Therefore, there is further provided a switching inductive step-up DC power converter (B) for improving the conventional DC power converter (A), as shown in Fig. 12. The switching inductive step-up DC power converter (B) includes an input terminal (B1), a first diode (B2), a second diode (B3), and a third diode. (B4), a switch (B5), a first inductor (B6), a second inductor (B7), an output diode (B8), an output capacitor (B9), and a load (B0) . One end of the input terminal (B1) is electrically connected to one end of the first inductor (B6) and the anode end of the third diode (B4). The other end of the first inductor (B6) is electrically connected to the anode end of the second diode (B3) and the anode end of the first diode (B2). The cathode end of the second diode (B3) is electrically connected to the cathode end of the third diode (B4) and one end of the second inductor (B7). The other end of the second inductor (B7) is electrically connected to the cathode end of the first diode (B2), one end of the switch (B5), and the anode end of the output diode (B8). The cathode end of the output diode (B8) is electrically connected to one end of the output capacitor (B9) and one end of the load (B0). The other end of the output capacitor (B9), the other end of the load (B0) and the other end of the switch (B5) are electrically connected to the other end of the input terminal (B1). The voltage gain ratio is: (1+D)/(1-D), where D is the duty cycle and D is between 0 and 1.

Furthermore, there is a patented high-boost ratio DC converter, such as the Republic of China Invention Patent Publication No. I429176 "High Boost Ratio DC Converter", in which the first and second switches are controlled by a control chip, and The first and second switches are both turned on, the first switch is turned on, the second switch is turned off, the first switch and the second switch are turned on, the first switch is turned off, and the second switch is turned on, so that a first and second inductors and a first The first and second clamp capacitors release energy to a first and second output capacitors, so that the first and second output capacitors are capable of releasing energy to a load after being stored. Thus, the power supply voltage output from the DC power supply to the load is boosted by the release of the first and second output capacitors, and the boost ratio is 4/(1-D).

In summary, the conventional system has the following deficiencies:

1. The conventional DC power converter of the eleventh figure has a voltage gain ratio of 1/(1-D). However, there is still a disadvantage that the high boost ratio cannot be improved due to the problem of circuit conversion efficiency under the higher duty cycle operation.

2. The switching inductive step-up DC power converter of the twelfth figure has a voltage gain ratio of (1+D)/(1-D). However, there is still a disadvantage that the high boost ratio cannot be improved due to the problem of circuit conversion efficiency under the higher duty cycle operation.

3. The conventional "high step-up ratio DC converter" has a voltage gain ratio of 4/(1-D). However, this converter uses two toggle switches and is costly.

Therefore, in order to improve the conventional conventional DC power converter and the switching inductive step-up DC power converter, under the higher duty cycle operation, the high conversion ratio cannot be improved due to the circuit conversion efficiency problem. Disadvantages. Therefore, the present invention provides a high step-up ratio DC power converter, comprising: an input unit, which is a continuous input current; a DC-DC conversion circuit with a high step-up ratio, the DC-DC with a high step-up ratio One side of the conversion circuit is electrically connected to the input unit, wherein the DC-DC conversion circuit with a high step-up ratio includes a first inductor, a second inductor, a third inductor, and a first diode a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, and a switch; wherein the first inductor is terminated Electrically connecting one end of the input unit, the anode end of the third diode and the anode end of the sixth diode, and the other end of the first inductor is electrically connected to the anode end of the second diode An anode end of the first diode, a cathode end of the second diode is electrically connected to a cathode end of the third diode and one end of the second inductor, and the other end of the second inductor is electrically connected Connecting an anode end of the fourth diode and an anode end of the fifth diode, the fifth The cathode end of the body is electrically connected to the cathode end of the sixth diode and one end of the third inductor, and the other end of the third inductor is electrically connected to the cathode end of the fourth diode, the first two a cathode end of the pole body and one end of the switch, the other end of the switch is electrically connected to the other end of the input unit; and an output unit electrically connected to the DC with a high boost ratio The other side of the DC conversion circuit includes an output diode, an output capacitor, and a load, wherein a cathode end of the first diode is electrically connected to an anode end of the output diode, and the output is The cathode end of the pole body is electrically connected to one end of the output capacitor and one end of the load, and the other end of the output capacitor is electrically connected to the other end of the load to the other end of the switch and the other end of the input unit; The DC power is input to the DC-DC conversion circuit with a high boost ratio by the input unit, and when the switch is turned on, one of the DC power is stored in the first inductor, the second inductor, and the third Inductance; When the switch is turned off, the first inductor, the second inductor, and the third inductor respectively release the energy to the output capacitor and the load, so that the DC current on the load is due to the first inductor and the second The energy of the inductor and the third inductor is released and boosted, wherein a voltage gain ratio of the output unit to the input unit is (1+2D)/(1-D), wherein D is a duty cycle, and the D system is Between 0 and 1.

The inductance values of the first inductor, the second inductor, and the third inductor are the same.

Among them, a pulse width modulation technique is used to control the on and off of the switch.

The direct current input by the input unit is one of a solar battery or a fuel battery.

The switching relationship is an N-type metal oxide semiconductor field effect transistor.

The effect of the invention is:

1. The invention mainly inputs a low direct current to a high step-up ratio DC-DC conversion circuit by one input unit of a high step-up ratio DC power converter, and the high step-up ratio DC power converter One of the output units has a high DC power. Wherein, when the switching switch of the DC-DC conversion circuit with the high step-up ratio is turned on, the first inductor, the second inductor and the third inductor of the DC-DC converter circuit having the high step-up ratio Storing energy; and when the switch is turned off, the first inductor, the second inductor, and the third inductor respectively transmit the stored energy to an output capacitor of the DC-DC conversion circuit with a high step-up ratio A load. The ratio of the voltage of the output unit to the voltage of the input unit is (1+2D)/(1-D), where D is the duty cycle and D is between 0 and 1. That is, the present invention has a high voltage gain ratio.

2. The present invention converts a low direct current to a DC-to-DC conversion circuit with a high step-up ratio to obtain a high direct current. That is, the high step-up ratio DC power converter of the present invention has a high boost ratio.

3. The high boost ratio DC power converter of the present invention only needs to use one switch. Therefore, it has the effect of low cost.

In summary of the above technical features, the main effects of the high step-up ratio DC power converter of the present invention will be apparent from the following embodiments.

First, referring to the first figure, which is a circuit diagram of the present invention, the high step-up ratio DC power converter (1) includes:

An input unit (11), the input unit (11) includes an input terminal (111), which is mainly an input current. In this embodiment, the DC power input by the input unit (11) is one of a solar cell or a fuel cell. Wherein, the solar cell and the fuel cell are both a green energy source, and both are a low voltage direct current.

A DC-DC conversion circuit (12) having a high step-up ratio is electrically connected to the input unit (11) on one side of the DC-DC conversion circuit (12) having a high step-up ratio. The DC-DC conversion circuit (12) having a high step-up ratio includes a first inductor (121), a second inductor (122), a third inductor (123), and a first diode. (124), a second diode (125), a third diode (126), a fourth diode (127), a fifth diode (128), and a sixth diode (129) and a switch (120). One end of the first inductor (121) is electrically connected to one end of the input end (111) [positive end], the anode end of the third diode (126) and the sixth diode (129) The anode end of the). The other end of the first inductor (121) is electrically connected to the anode end of the second diode (125) and the anode end of the first diode (124). The cathode end of the second diode (125) is electrically connected to the cathode end of the third diode (126) and one end of the second inductor (122). The other end of the second inductor (122) is electrically connected to the anode end of the fourth diode (127) and the anode end of the fifth diode (128). The cathode end of the fifth diode (128) is electrically connected to the cathode end of the sixth diode (129) and one end of the third inductor (123). The other end of the third inductor (123) is electrically connected to the cathode end of the fourth diode (127), the cathode end of the first diode (124), and one end of the switch (120). The other end of the switch (120) is electrically connected to the other end [negative terminal] of the input terminal (111). In this embodiment, the switch (120) is an N-type metal oxide semiconductor field effect transistor.

An output unit (13) electrically connected to the other side of the DC-DC conversion circuit (12) having a high step-up ratio. The output unit (13) includes an output diode (131), an output capacitor (132), and a load (133). The cathode end of the first diode (124) is electrically connected to the anode end of the output diode (131). The cathode end of the output diode (131) is electrically connected to one end of the output capacitor (132) and one end of the load (133). The other end of the output capacitor (132) is electrically connected to the other end of the switch (120) and the other end of the input terminal (111) [negative terminal].

Again, please see the second picture. It is the main waveform diagram of the invention in a single switching cycle. Moreover, the present invention employs a pulse width modulation technique and controls the on and off of the switch (120) [as shown in the first figure].

In addition, when operating, please refer to the third and fourth figures. Wherein, the invention controls the on and off of the switch (120) by using the pulse width modulation technology, and is divided into the following two operation modes:

Mode 1: Its operating interval is [t ₀ , t ₁ ]. When the switch (120) is turned on, its current path is indicated by the arrow of the third figure. In this interval, the input terminal (111) transmits an energy to the first inductor (121), the second inductor (122), and the third inductor (123). The output capacitor (132) releases the energy and supplies the load (133). At this time, the voltage across the first inductor (121), the second inductor (122), and the third inductor (123) is all Vin. The first inductor (121), the second inductor (122), and the third inductor (123) store energy in parallel. Therefore, the currents on the first inductor (121), the second inductor (122), and the third inductor (123) increase linearly, as shown in the second figure. Mode 1 ends at t=t1, and the switch (120) is turned off.

Mode 2: Its operating interval is [t ₁ , t ₂ ]. When the switch (120) is turned off, its current path is as indicated by the arrow in the fourth figure. In this interval, the input terminal (111) releases energy in series with the first inductor (121), the second inductor (122), and the third inductor (123), and is released to the output capacitor (132). The load (133). At this time, the voltage across the first inductor (121), the second inductor (122), and the third inductor (123) is (Vin - Vo) / 3. Therefore, the currents on the first inductor (121), the second inductor (122), and the third inductor (123) linearly decrease, as shown in the second figure. Mode 2 ends at the beginning of the next switching cycle, ie the switching switch (120) is conducting.

However, according to the voltage-second balance of the first inductor (121), a voltage gain M = (1 + 2D) / (1-D) is obtained. Where D is the duty cycle and the D is between 0 and 1.

Again, please see the fifth picture. It is an analog waveform diagram of the input voltage and output voltage of the input voltage 24V, the output voltage 200V, and the full load output power 200W. The scale value of the waveform diagram is: V _in /V _o : 50V/div, time: 2ms/div. It can be seen from the figure that the present invention inputs a low voltage direct current, and a high voltage direct current can be obtained after being converted by the power converter. That is, the present invention can provide a high boost ratio effect.

Again, please see the sixth picture. The simulation of the voltage [V _L1 ] of the first inductor (121) with the input voltage of 24V, the output voltage of 200V, the full-load output power of 200W, and the gate-source output voltage [V _GS1 ] of the switch (120) Waveform diagram. The scale value of the waveform diagram is: V _L1 : 20V/div, time: 10μs/div. Wherein, when the switch (120) is turned on, V _L1 = V _in = 24 V. When the switch (120) is turned off, V _L1 = (V _in - V _o ) / 3 = -58.7 V.

Again, please see the seventh picture. Is the simulation of the current [i _L1 ] of the first inductor (121) with the input voltage of 24V, the output voltage of 200V, the full load output power of 200W, and the gate-source output voltage [V _GS1 ] of the switch (120). Waveform diagram. The scale value of the waveform diagram is: i _L1 : 1 A / div, time: 10 μs / div.

Again, please see the eighth picture. The present invention is an analog waveform of the current [i _S1 ] of the switch (120) with the input voltage of 24V, the output voltage of 200V, the full load output power of 200W, and the gate-source output voltage [V _GS1 ] of the switch (120). Figure. The scale values of the waveform diagram are: i _S1 : 3A/div, time: 10 μs/div.

Again, please see the ninth figure. The current [i _D1 ] of the first diode (124) with an input voltage of 24V, an output voltage of 200V, a full-load output power of 200W, and the gate-source output voltage of the switch (120) [V _GS1 ] Analog waveform diagram. The scale value of the waveform diagram is: i _D1 : 1 A / div, time: 10 μs / div.

Again, please see the tenth figure. Is the current [i _D2 ] of the second diode (125) with an input voltage of 24V, an output voltage of 200V, a full-load output power of 200W, and the gate-source output voltage of the switch (120) [V _GS1 ] Analog waveform diagram. The scale value of the waveform diagram is: i _D2 : 1 A / div, time: 10 μs / div.

Furthermore, the eleventh picture shows a conventional boost converter (A). The twelfth picture shows a switched inductive DC power converter (B). The thirteenth figure is a voltage gain diagram of the high boost ratio DC power converter (1) of the present invention compared with the conventional boost converter (A) and the switched inductive DC power converter (B). Curve A is the voltage gain of the high boost ratio DC power converter (1) with the duty cycle of the present invention; curve B is the voltage gain of the switched inductive DC power converter (B) with the duty cycle. Curve C is the voltage gain that the conventional boost converter (A) increases with the duty cycle. As can be seen from the thirteenth figure, the voltage gain of the high step-up ratio DC power converter (1) of the present invention is significantly higher than that of the conventional boost converter (A) and the switching inductive DC power converter (B). That is, the present invention has the effect of having a high step-up ratio.

In view of the above description of the embodiments, the operation, use, and effects of the present invention can be fully understood. The above described embodiments are merely preferred embodiments of the invention, and are not intended to limit the scope of the invention. That is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are within the scope of the invention.

(1)‧‧‧High boost ratio DC power converter (11)‧‧‧ Input unit (111)‧‧‧ Input (12)‧‧‧ DC-DC converter circuit with high boost ratio (121) ‧‧‧First Inductance (122)‧‧‧Second Inductance (123)‧‧ Third Inductor (124)‧‧‧First Diode (125)‧‧‧Second Dipole (126)‧ ‧‧Third diode (127)‧‧4th diode (128)‧‧‧5th diode (129)‧‧6th diode (120)‧‧‧Switch switch (13 )‧‧‧Output unit (131)‧‧‧ Output diode (132)‧‧‧ Output capacitance (133)‧‧‧Load (A)‧‧‧ Traditional boost converter (A1)‧‧‧ input Terminal (A2)‧‧‧Inductor (A3)‧‧‧Switching switch (A4)‧‧‧Output diode (A5)‧‧‧ Output capacitance (A6)‧‧‧ Load (B)‧‧‧Switching inductance DC Power Converter (B1)‧ ‧ Inputs (B2) ‧ ‧ First diode (B3) ‧ ‧ Second diode (B4) ‧ ‧ Third diode (B5) ‧ ‧ Switch (B6) ‧ ‧ First Inductor (B7)‧‧‧Second Inductor (B8)‧‧‧Output Diode (B9)‧‧‧ Output Capacitor (B0)‧‧‧ Load

[First figure] is a circuit diagram of the present invention. [Second picture] is a waveform diagram of a high step-up ratio DC power converter of the present invention in a single switching period. [Third image] is a current path diagram of the high boost ratio DC power converter operating in the mode of the present invention. [Fourth diagram] is a current path diagram of the high boost ratio DC power converter operating in mode 2 of the present invention. [Fifth diagram] is an analog waveform diagram of an input voltage and an output voltage of an input voltage of 24V, an output voltage of 200V, and a full-load output power of 200W. [Sixth] is an analog waveform diagram of the voltage of the first inductor operating at the input voltage of 24V, the output voltage of 200V, and the full-load output power of 200W, and the gate-source voltage of the switch. [Seventh figure] is an analog waveform diagram of the current of the first inductor operating at the input voltage of 24V, the output voltage of 200V, and the full-load output power of 200W, and the gate-source voltage of the switch. [Eighth image] is an analog waveform diagram of the current of the switch of the input voltage of 24V, the output voltage of 200V, and the full load output of 200W, and the gate-source voltage of the switch. [Ninth diagram] is an analog waveform diagram of the current of the first diode operating at the input voltage of 24V, the output voltage of 200V, and the full-load output power of 200W, and the gate-source voltage of the switch. [Tenth Graph] is an analog waveform diagram of the current of the second diode of the input voltage of 24V, the output voltage of 200V, and the full load output of 200W, and the gate-source voltage of the switch. [11th] is a circuit diagram of a conventional conventional step-up DC power converter. [Twelfth Figure] is a circuit diagram of a conventional switched inductive step-up DC power converter. [Thirteenth Diagram] is a voltage gain diagram of a conventional conventional step-up DC power converter, a conventional switched inductive step-up DC power converter, and a high step-up DC power converter of the present invention.

(1)‧‧‧High boost ratio DC power converter

(11)‧‧‧ Input unit

(111)‧‧‧ Input

(12) ‧‧‧DC-DC converter circuit with high boost ratio

(121)‧‧‧First inductance

(122)‧‧‧second inductance

(123)‧‧‧ Third inductance

(124)‧‧‧First Diode

(125)‧‧‧Secondary diode

(126)‧‧‧ Third Dipole

(127)‧‧‧Fourth diode

(128) ‧‧‧ fifth diode

(129)‧‧‧ Sixth diode

(120)‧‧‧Switch

(13)‧‧‧Output unit

(131)‧‧‧ Output diodes

(132)‧‧‧ Output capacitance

(133)‧‧‧ Load

Claims (5)

A high step-up ratio DC power converter comprising: an input unit for inputting a continuous current; a DC-DC conversion circuit with a high step-up ratio, one side of the DC-DC conversion circuit with a high step-up ratio Electrically connecting the input unit, wherein the DC-DC conversion circuit with a high step-up ratio includes a first inductor, a second inductor, a third inductor, a first diode, and a second a diode, a third diode, a fourth diode, a fifth diode, a sixth diode, and a switch; wherein one end of the first inductor is electrically connected to the input One end of the unit, an anode end of the third diode, and an anode end of the sixth diode, the other end of the first inductor is electrically connected to the anode end of the second diode and the first diode The cathode end of the second diode is electrically connected to the cathode end of the third diode and one end of the second inductor, and the other end of the second inductor is electrically connected to the fourth The anode end of the pole body and the anode end of the fifth diode, the cathode end of the fifth diode The cathode end of the sixth diode is electrically connected to one end of the third inductor, and the other end of the third inductor is electrically connected to the cathode end of the fourth diode, the cathode end of the first diode, and One end of the switch, the other end of the switch is electrically connected to the other end of the input unit; and an output unit electrically connected to the DC-DC converter circuit with a high step-up ratio One side includes an output diode, an output capacitor, and a load, wherein a cathode end of the first diode is electrically connected to an anode end of the output diode, and a cathode end of the output diode Electrically connecting one end of the output capacitor to one end of the load, and the other end of the output capacitor is electrically connected to the other end of the load to the other end of the switch and the other end of the input unit; The DC power is applied to the DC-DC conversion circuit with a high step-up ratio. When the switch is turned on, one of the DC power is stored in the first inductor, the second inductor, and the third inductor; Toggle switch The first inductor, the second inductor, and the third inductor respectively release the energy to the output capacitor and the load, so that the DC current on the load is due to the first inductor, the second inductor, and the first The energy of the three inductors is released and boosted, wherein the voltage gain ratio of the output unit to the input unit is (1+2D)/(1-D), where D is the duty cycle and the D system is between 0 and 1. between. The high step-up ratio DC power converter of claim 1, wherein the inductances of the first inductor, the second inductor, and the third inductor are the same. The high step-up ratio DC power converter according to claim 1, wherein the switch is turned on and off by a pulse width modulation technique. The high step-up ratio DC power converter according to claim 1, wherein the input unit is DC power inputted by one of a solar cell or a fuel cell. The high step-up ratio DC power converter according to claim 1, wherein the switching-on relationship is an N-type metal oxide semiconductor field effect transistor.