TWI466423B - High boost power converter - Google Patents

Description

High boost power converter

The invention relates to a high-boost power converter, in particular to a high-boost power converter combined with a coupled inductor and a voltage boosting technique, which mainly adjusts the turns ratio of the coupled inductor and utilizes a voltage boosting technique and a voltage doubler circuit. Achieve a high boost ratio.

According to the High Step-up Ratio DC-DC Converter, it is widely used in industrial electrical appliances and commercially available products, such as computer peripheral power supply and uninterruptible power supply (Uninterruptible Power Supply, UPS) and High Intensity Discharge Lamp (HID Lamp) require a DC-DC power supply with high step-up ratio and high efficiency.

The traditional boost converter (Boost Converter) can not meet the required high boost ratio even when the operation is under a very high duty cycle. When the converter switch operates at a very high duty cycle. The high voltage of the input voltage relative to the output side makes the problem of reverse recovery of the output diode quite serious, reducing the converter stability.

In order to improve the reverse recovery of the diode, a booster inductor with a coupled inductor (Coupled Inductor with Boost Converter) is used to improve; when the turns ratio of the coupled inductor is increased, the boost ratio of the converter can be changed; However, the relative problem derived from the coupled inductor is that the leakage inductance energy is released on the parasitic capacitance on the switch, causing voltage surge on the switch, increasing switching loss and reducing converter efficiency.

In 2005, TJLiang and KCTseng proposed an integrated Boost-Flyback Converter (IBFC), which uses a coupled inductor technology to integrate a boost converter circuit with a flyback converter circuit to convert The circuit has high efficiency, low voltage stress power switches and output capacitors.

For example, the "power conversion device" of the Japanese Patent Publication No. TW201117540 A1, wherein the third embodiment

It can be seen that there are still many shortcomings in the above-mentioned household items, which is not a good designer and needs to be improved.

In view of the shortcomings derived from the above-mentioned conventional high-boost power converters, the inventors of the present invention have improved and innovated, and after years of painstaking research, finally successfully developed and completed this high-boost power converter.

The object of the present invention is to provide a high-boost power converter with a high-boost power converter with low switching voltage stress, which has the characteristics of high step-up ratio, high conversion efficiency and low switching voltage stress, mainly utilizing Coupled inductors, voltage boosting technology and voltage doubling circuit to achieve high boost ratio.

A second object of the present invention is to provide a high-boost power converter, so that the leakage inductance energy stored in the coupled inductor can be recovered and regenerated by the power switch during the cut-off period, thereby improving the conversion efficiency and effectively clamping Voltage surge on the power switch.

The high-boost power converter capable of achieving the above object includes: a high-boost power conversion circuit, wherein an input power source is connected in series with a power switch and a first coupled inductor, and the first coupled inductor is respectively connected in series with the first end The capacitor and the first diode are connected to an extended voltage gain circuit; an extended voltage gain circuit is connected by a clamp inductor to the second diode and the second capacitor, and is electrically connected to a filter circuit; The circuit is connected by a third diode to the first output capacitor and electrically connected to the double voltage circuit; the double voltage circuit is connected by the second coupled inductor to the fourth diode and the fifth The pole body is connected in series with the second and third output capacitors, and finally a load resistor is connected in parallel.

Referring to FIG. 1 , a high-boost power converter provided by the present invention mainly includes: a high-boost power conversion circuit 1 , wherein an input power source V _{in is} connected _in series with a power switch Q and a first coupled inductor N ₁ . The first coupling inductor N ₁ is connected in series with the first capacitor C ₁ and the first diode D ₁ , and is connected to an extended voltage gain circuit 2; an extended voltage gain circuit 2 is connected in series by a clamp inductor Lc. The second diode D ₂ and the second capacitor C ₂ are electrically connected to a filter circuit 4; a filter circuit 4 is connected in series with the first output capacitor C _o1 by a third diode D ₃ , and is electrically connected Connecting the double voltage circuit 3; the voltage doubler circuit 3 is connected in series with the fourth diode D ₄ and the fifth diode D ₅ by the second coupling inductor N ₂ , and then connected in series with the second and third outputs Capacitors C _o2 , C _o3 , and finally a parallel load resistor R _L .

High-boost power converters are generally suitable for applications requiring higher output voltages, depending on the different boost ratios of the architecture. The boost ratio can usually only be adjusted by adjusting the coupling inductance turns ratio; when the required turns are large When the power is high or the number of copper wires is large, a larger coil bobbin and iron core are required. Therefore, a structure combining the coupled inductor and the voltage lift technology is proposed to overcome the above problem and improve the boost ratio of the circuit.

The architecture of the high-boost power converter of the present invention partially functions as a clamp switch voltage, and the voltage doubler circuit 3 stores energy through the coupled inductor in the output capacitor through the power switch Q or the diode conduction to improve the boost ratio. The output capacitor portion is formed by connecting the first, second, and third output capacitors C _o1 , C _o2 , and C _{o3 in} series to solve the conventional boost circuit architecture, and the output capacitor withstand voltage specifications are difficult to select. problem.

Figure 2 shows the main waveform of the high-boost power converter. According to each working state, the basic working principle can be divided into seven operating states:

Mode 1[t ₀ <t≦t ₁ ]:

When t=t ₀ , the power switch Q is turned on, and its circuit state is as shown in FIG. 3. At this time, the second diode D ₂ and the fourth diode D _{4 are} turned on, the first diode D ₁ , the first The triode D ₃ and the fifth diode D _{5 are turned} off, the input power source V _in is stored by the power switch Q to the leakage inductance L _k1 , and the input power source V _in is also passed through the second diode D ₂ The capacitor C ₁ and the clamp inductor L _c store energy, and the second capacitor C ₂ releases energy through the power switch Q; at this time, the excitation inductance L _m and the leakage inductance L _k2 energy release are stored in the second output capacitor C _o2 , i _Lm drops to Initially, the energy required to load R _L is provided by three output capacitors.

Mode 2[t ₁ <t≦t ₂ ]:

When t=t ₁ , the power switch Q is turned on, and its circuit state is as shown in FIG. 4 . At this time, the second diode D ₂ and the fifth diode D _{5 are} turned on, the first diode D ₁ , the first thirty-two diode D ₃ and the fourth diode D ₄ is turned off, the input power source via the power switch Q V _in the magnetizing inductance L _m of the leakage inductance L _k1 store energy while the power supply V _in is also input via a second diode D ₂ stores energy for the first capacitor C ₁ and the clamp inductor L _c , and the second capacitor C ₂ releases energy through the power switch Q; at this time, the input power source V _in transfers energy to the second coupling through the first coupled inductor N ₁ The inductor N ₂ stores energy to the leakage inductance L _k2 and the third output capacitor C _o3 , the magnetizing inductor current i _LM is increased by an initial value, and the energy required for the load R _L is provided by three output capacitors.

Mode 3[t ₂ <t≦t ₃ ]:

When t=t ₂ , the power switch Q is turned on, and its circuit state is as shown in FIG. 5 . At this time, the fifth diode D _{5 is} turned on, the first diode D ₁ , the second diode D ₂ , and the first The diode D ₃ and the fourth diode D _{4 are turned} off, and the input power source V _in is stored by the power switch Q for the magnetizing inductance L _m and the leakage inductance L _k1 , and the first capacitor C ₁ and the second capacitor C ₂ are The clamp inductor L _c cannot transfer energy due to the second diode D ₂ cutoff; at the same time, the input power source V _in transfers energy to the second coupled inductor N ₂ to the drain inductor L _k2 and the third output capacitor by the first coupled inductor N ₁ C _o3 stores energy, the magnetizing inductor current i _Lm increases to the highest value, and the energy required to load R _L is provided by the output capacitor.

Mode 4[t ₃ <t≦t ₄ ]:

When t=t ₃ , the power switch Q is turned off, and the circuit state thereof is as shown in FIG. 6. At this time, the first diode D ₁ , the third diode D ₃ and the fifth diode D _{5 are} turned on, two diode D ₂ and the fourth diode D ₄ is turned off, the first capacitor C ₁ via the first diode D ₁ the release of energy to the leakage inductance L _K1, input power V _in by the magnetizing inductance L _m and a leakage inductance L _K1 stores energy to the parasitic capacitance C _oss of the power switch Q, and also stores energy to the second capacitor C ₂ and the first output capacitor C _o1 via the third diode D ₃ ; the input power source V _{in is} coupled by the first coupled inductor N ₁ transfers energy to the second coupled inductor N ₂ to store energy to the leakage inductance L _k2 and the third output capacitor C _o3 , the magnetizing inductor current i _Lm is decreased by the highest value, and the energy required to load the R _L is provided by the output capacitor.

Mode 5[t ₄ <t≦t ₅ ]:

When t=t ₄ , the power switch Q is turned off, and the parasitic capacitance C _oss has been stored, and the circuit state is as shown in FIG. 7 . At this time, the first diode D ₁ and the third diode D ₃ are a fourth diode D ₄ is turned on, the second diode D ₂ and the fifth diode D ₅ is turned off, the first capacitor C ₁ via the first diode D ₁ the release of energy to the leakage inductance L _k1, the input power supply V _Is stored by the third diode D ₃ via the magnetizing inductance L _m and the leakage inductance L _k1 to the second capacitor C ₂ and the first output capacitor C _o1 ; while the excitation inductance L _m and the leakage inductance L _{k2 are} released in energy storage The second output capacitor C _o2 , the magnetizing inductor current i _Lm continues to drop, and the energy required to load R _L is provided by three output capacitors.

Mode 6[t ₅ <t≦t ₆ ]:

When t=t ₅ , the power switch Q is turned off, and the circuit state thereof is as shown in FIG. 8. At this time, the first diode D ₁ , the third diode D ₃ and the fourth diode D _{4 are} turned on, two diode D ₂ and the fifth diode D ₅ is turned off, the first capacitor C ₁ via the first diode D ₁ the release of energy to the leakage inductance L _k1, V _in the input power by a third diode D ₃ And the fourth diode D ₄ stores the energy to the second capacitor C ₂ and the second output capacitor C _o2 via the magnetizing inductance L _m and the leakage inductance L _k1 ; while the excitation inductance L _m and the leakage inductance L _{k2 are} released in energy and stored in the second The output capacitor C _o2 , the magnetizing inductor current i _Lm continues to drop, and the energy required to load R _L is provided by three output capacitors.

Mode 7[t ₆ <t≦t ₇ ]:

When t=t ₆ , the power switch Q is turned off, and its circuit state is as shown in FIG. 9 . At this time, the fourth diode D _{4 is} turned on, the first diode D ₁ , the second diode D ₂ , and the first The triode D ₃ and the fifth diode D _{5 are turned} off, so the input power source V _in and the leakage inductance L _k1 have no transmission path to provide energy; and the excitation inductance L _m and the leakage inductance L _k2 energy release are stored in the second output. Capacitor C _o2 , the magnetizing inductor current i _Lm continues to drop, and the energy required to load R _L is provided by three output capacitors.

When the power switch Q is turned on, the following relationship can be obtained by the equivalent circuit: V _M = V _Lm = V _in , V _C2 = V _C1 + V _in , V _N2 = V _o3 = (N ₂ / N ₁ ) V _Lm =(N ₂ /N ₁ )V _in

When the power switch Q is turned off, the following relationship can be obtained by the equivalent circuit: V _Lm = -V _C1 , V _o1 = V _C1 + V _C2 + V _in , V _N2 = -V _o2

It can be known from the above equation that the relationship between the output and the input voltage is: V _o /V _in =2+(N ₂ /N ₁ )/1-D

To verify the operation principle of the above, the embodiment of the proposed simulation and experimental results a preferred embodiment, the input voltage V _in is set to DC 12V, the output specifications of 200V / 150W, and the switching frequency is 50kHz: 10, for the implementation Measured power switch drive signal V _GS , power switch voltage V _DS and power switch current i _DS waveform diagram, as shown in the figure, when the output of the high-boost power converter with coupled inductor and voltage lift technology is full load, the measurement The switching frequency of the power switch Q is f _s = 50 kHz.

Among them, the magnitude of the power switch voltage measured by the implementation is V _DS =32V, the peak of the switching current is i _DS =24A high, and the converter duty cycle is D=0.56.

As shown in FIG. 11, the waveform diagram of the power switch drive signal V _GS , the first capacitor current i _{c1 ,} and the first diode current i _D1 measured for actual measurement, as shown in the figure, the power switch of the high-boost power converter when Q is turned on, due to energy flow from the input terminal of the first capacitor C _1, so the first current i _C1 is the storage capacitor, a first diode D At this time, _a reverse bias is turned off; when the power of the high-boost power converter switches Q when turned off, the first capacitor C ₁ by the first diode D ₁ forward conducting path is formed passing through the leakage inductance L _k1, when the first capacitor is released an amount of current i _c1.

Wherein, the measured peak current of the first capacitor current is i _c1 =2.3A, and the peak value of the first diode current is i _D1 =9A.

As shown in FIG. 12, the waveform diagram of the power switch drive signal V _GS , the clamp inductor current i _Lc and the second diode current i _D2 for actual measurement is shown in the figure, when the power switch of the high boost power converter is shown When Q is turned on, the clamp inductor L _C forms a path through the power switch Q due to the second diode D ₂ flowing forward. At this time, the clamp inductor Lc is the clamped power switch voltage V _Ds and the second diode current i _D2 .

Among them, the measured second diode current is i _D2 = 2.5A, and the clamped inductor current is i _Lc = 2.5A, which are very close.

As shown in FIG. 13, the power switch drive signal V _GS , the second capacitor current i _{c2 ,} and the third diode current i _D3 waveform are actually measured. As can be seen from the figure, when the power of the high boost power converter is when the switch Q is turned on, because the second diode D ₂ is formed along a second conducting capacitor C ₂ Q path flowing through the power switch, the second capacitor _C2 is discharging current I, now the third diode D ₃ Reverse bias cutoff; when the power switch Q of the high boost power converter is turned off, the second capacitor C ₂ forms a path through the first output capacitor C _o1 due to the third diode D ₃ flowing forward, and the second capacitor Current i _C2 is energy storage.

Wherein, the measured peak value of the second capacitor current is i _C2 = 5A, and the peak value of the third diode current is i _D3 = 5A.

As shown in FIG. 14, the waveform diagram of the power switch drive signal V _GS , the diode current i _{D4 ,} and the diode current i _D5 for actual measurement is shown in the figure, when the power switch Q of the high boost power converter is shown. When turned on, the fifth diode D _{5 is} stored in the third output capacitor C _o3 by the conduction of the fifth diode D ₅ , and the fourth diode D _{4 is} reverse biased off; when the power switch Q of the high boost power converter is turned off, Because the fourth diode D _{4 stores the} energy to the second output capacitor C _o2 , the fifth diode D _{5 is} reverse biased.

Among them, the measured peak value of the fourth diode current is i _D4 = 2.4A, and the peak value of the power switch current is i _DS = 1.6A.

As shown in Figure 15, the high-boost power converter achieves a conversion efficiency of 86.83% at 10W light load, and the high-boost power converter enters continuous conduction mode at approximately 29W converter. The maximum conversion efficiency can be achieved when the output power is about 60W. 99.01%, but as the output power increases, the current of the power switch Q also increases.

As shown in Figure 10, when the converter is fully loaded (150W), the current of the power switch Q is up to 24A, so the conversion efficiency is also reduced, but the output power is full load (150W), still 90.16% High efficiency.

The detailed description of the preferred embodiments of the present invention is intended to be limited to the scope of the invention, and is not intended to limit the scope of the invention. The patent scope of this case.

In summary, this case is not only innovative in terms of space type, but also can enhance the above-mentioned multiple functions compared with the customary items. It should fully meet the statutory invention patent requirements of novelty and progressiveness, and apply for it according to law. This invention patent application, in order to invent invention, to the sense of virtue.

1. . . High boost power conversion circuit

2. . . Extended voltage gain circuit

3. . . Voltage doubling circuit

4. . . Filter circuit

V _in . . . Input power

V _GS . . . Power switch drive signal

V _DS . . . Power switch voltage

Q. . . Power switch

N ₁ . . . First coupled inductor

N ₂ . . . Second coupled inductor

C ₁ . . . First capacitor

C ₂ . . . Second capacitor

C _o1 . . . First output capacitor

C _o2 . . . Second output capacitor

C _o3 . . . Third output capacitor

C _oss . . . Parasitic capacitance

D ₁ . . . First diode

D ₂ . . . Second diode

D ₃ . . . Third diode

D ₄ . . . Fourth diode

D ₅ . . . Fifth diode

L _m . . . Magnetizing inductance

Lc. . . Clamping inductance

L _k1 , L _k2 . . . Leakage inductance

i _LM . . . Magnetizing inductor current

i _DS . . . Power switch current

R _L . . . load

1 is a circuit diagram of a high boost power converter of the present invention;

2 is a waveform diagram of the high boost power converter;

3 is a circuit state diagram of t ₀ <t≦t _{1 of} the high-boost power converter;

4 is a circuit diagram of the circuit of t ₁ <t≦t _{2 of} the high-boost power converter;

Figure 5 is a circuit diagram of the t ₂ <t≦t ₃ circuit of the high-boost power converter;

6 is a circuit diagram of the circuit of t ₃ <t≦t _{4 of} the high-boost power converter;

7 is a circuit state diagram of the t ₄ <t≦t _{5 of} the high-boost power converter;

Figure 8 is a circuit diagram of the circuit of t ₅ <t≦t _{6 of} the high-boost power converter;

Figure 9 is a circuit diagram of the circuit of t ₆ <t≦t _{7 of} the high-boost power converter;

10 is a waveform diagram of a power switch drive signal V _GS , a power switch voltage V _{DS ,} and a power switch current i _{DS of} the high-boost power converter;

11 is a waveform diagram of the power switch drive signal V _GS , the first capacitor current i _{c1 ,} and the first diode current i _{D1 of} the high-boost power converter;

12 is a waveform diagram of the power switch driving signal V _GS , the clamped inductor current i _{Lc ,} and the second diode current i _{D2 of} the high-boost power converter;

13 is a waveform diagram of the power switch drive signal V _GS , the second capacitor current i _{c2 ,} and the third diode current i _{D3 of} the high-boost power converter;

14 is a waveform diagram of a power switch driving signal V _GS , a diode current i _{D4 ,} and a diode current i _{D5 of} the high-boost power converter; and

Figure 15 is a graph showing the measurement efficiency of the high-boost power converter.

1‧‧‧High boost power conversion circuit

2‧‧‧Extended voltage gain circuit

3‧‧‧ double voltage circuit

4‧‧‧Filter circuit

V _in ‧‧‧Input power supply

Q‧‧‧Power switch

N ₁ ‧‧‧First coupled inductor

N ₂ ‧‧‧Second coupled inductor

C ₁ ‧‧‧first capacitor

C ₂ ‧‧‧second capacitor

C _o1 ‧‧‧first output capacitor

C _o2 ‧‧‧second output capacitor

C _o3 ‧‧‧ third output capacitor

D ₁ ‧‧‧First Diode

D ₂ ‧‧‧Secondary

D ₃ ‧‧‧third diode

D ₄ ‧‧‧fourth dipole

D ₅ ‧‧‧ fifth dipole

Lc‧‧‧Clamping Inductors

R _L ‧‧‧load

Claims (3)

A high-boost power converter includes: a high-boost power conversion circuit: an input power supply is connected in series with a power switch and a first coupled inductor, and the first coupled inductor is connected in series with a first capacitor and a first a diode body is connected to an extended voltage gain circuit; the extended voltage gain circuit is connected by a clamp inductor to a second diode and a second capacitor, and is electrically connected to a filter circuit; a filter circuit a third diode is connected in series with a first output capacitor and electrically connected to a voltage doubler circuit; the voltage doubler circuit is connected by a second coupled inductor to a fourth diode and a a fifth diode, a second output capacitor and a third output capacitor are connected in series, and finally a load resistor is connected in parallel; after the power switch is turned on, the second diode is electrically connected to the fourth diode, The first diode, the third diode, and the fifth diode are turned off, and the input power source stores energy to the leakage inductance via the power switch, and the input power source is also passed through the second diode. a capacitor is stored with the clamped inductor, and the second capacitor is Energy release the power switch, then magnetizing inductance and leakage inductance energy stored in the second release output, the magnetizing inductor current drops to the initial value, the energy provided by the three required output capacitive load. The high-boost power converter of claim 1 , wherein the first diode, the third diode, and the fifth diode are turned on, the second diode and the fourth The pole body is cut off, the first capacitor releases energy to the leakage inductance of the first coupled inductor via the first diode, and the input power source stores energy of the parasitic capacitance of the power switch through the excitation inductor and the leakage inductance. The triode stores energy to the second capacitor and the first output capacitor, and recovers energy of the leakage inductance, thereby improving conversion efficiency. The high-boost power converter according to claim 1 , wherein when the power switch is turned on, the second diode flows in a path to form a path of the second capacitor flowing through the power switch, so the second The capacitor current is the release energy, and the third diode is reverse biased off; when the power switch of the high-boost power converter is turned off, the second capacitor flows through the third diode due to the conduction of the third diode A path of the output capacitor, at which time the second capacitor current is energy storage, thereby achieving voltage surges that clamp the power switch.