TW201332272A - High step-up DC-DC converter and method thereof - Google Patents

Abstract

The configuration of a step-up converter and method thereof are provided. The proposed converter includes a coupled inductor having a primary winding, a secondary winding and a tertiary winding, wherein the primary winding is a main inductor of the converter, a voltage doubler connected to the secondary winding, and a clamping capacitor connected to the tertiary winding.

Description

High-boost DC-DC converter and method thereof

The present invention relates to a high boost converter, and more particularly to a high boost DC-DC converter having a coupled inductor, a voltage doubler and a clamping capacitor.

Various types of converters, such as booster/buck/boost-buck converters, are becoming more widely used, and how to further improve their shortcomings to contribute to, for example, boost converter efficiency gains and loss reduction, and lower energy Consumption is a question worth pondering.

The above-mentioned problems of improving the efficiency of the boost converter and reducing the loss thereof can generally increase the boost ratio of the boost converter, reduce the number of components required for the boost converter, lower the rated voltage of the switching element, and reduce the input current ripple. And several aspects of the leakage inductance energy of the recovery circuit to improve efficiency, increase reliability, reduce costs and save energy.

As a result of the job, the inventor, in view of the lack of the prior art, thought of and improved the idea of invention, and finally invented the "high-boost DC-DC converter and its method" of the present invention.

The main purpose of the present invention is to provide a high-boost converter having a coupled inductor, a voltage doubler circuit and a clamp capacitor, which can achieve a high boost ratio without being limited by a duty ratio; the high rise proposed by the present invention The voltage converter can reduce the number of components required by the boost converter, reduce the rated voltage of the switching component, reduce the input current ripple, and recover the leakage inductance energy of the circuit to the output capacitor, thereby improving the efficiency of the converter.

Another main object of the present invention is to provide a DC-DC boost converter comprising a magnetizing inductor, a coupled inductor, a primary winding connected to the magnetizing inductor, a secondary winding and a tertiary winding. The primary side winding is a main inductor of the converter, a voltage doubler circuit is connected to the secondary side winding, and a clamp capacitor is connected to the tertiary side winding.

A main purpose of the present invention is to provide a boost converter comprising a coupled inductor having a primary winding, a secondary winding and a tertiary winding, wherein the primary winding is one of the converters. An inductor, a voltage doubler circuit connected to the secondary side winding, and a clamp capacitor are connected to the tertiary side winding.

A further object of the present invention is to provide a control method for a DC-DC boost converter, wherein the converter includes a magnetizing inductor, a switch, a magnetizing inductor connected to one of the switches, and a connection The switch and one of the coupled inductors and a voltage doubler circuit connected to the coupled inductor include the following steps: utilizing the coupled inductor and the voltage doubler circuit to boost a voltage boost of the converter Ratio, such that it is not limited by one duty cycle of the converter; and the clamp capacitor is used to reduce one of the voltage stress of the switch and one of the voltage surges of the switch, and reduce one of the switching losses and one conduction of the switch loss.

Another main object of the present invention is to provide a control method for a boost converter, wherein the converter includes a magnetizing inductor, a coupled inductor connected to the magnetizing inductor, and a piezoelectric connected to the coupled inductor. The circuit includes a step of utilizing the coupled inductor and the voltage doubling circuit to boost a voltage boost ratio of the converter from a duty cycle of the converter.

The above described objects, features, and advantages of the present invention will become more apparent and understood.

The high-boost DC-DC converter proposed by the present invention combines a three-winding coupled inductor and a voltage doubling circuit to increase a voltage boost ratio of the converter without being limited by one duty cycle of one switch; Include a clamping capacitor to clamp a switch across the voltage of the converter so that the voltage stress of one of the switches can be maintained at a lower level, so that a lower rated power and a lower on-resistance can be used. The switch can also reduce one of the voltage surges on the switch, thereby reducing one of the switching losses and a conduction loss of the converter; and operating the input current of the converter in a continuous conduction mode to reduce a current ripple At the same time, it also improves the reliability and lifetime of one of the input filters of the converter.

The first figure is a circuit diagram showing a high step-up DC-DC converter in accordance with a preferred embodiment of the present invention. In the first figure, the DC-DC boost converter includes a magnetizing inductance L _m , a coupled inductor 11 having a primary winding N ₁ connected to the magnetizing inductance L _m and a secondary winding N ₂ and a tertiary side winding N ₃ , wherein the primary side winding N ₁ is a main inductor of the converter, a voltage doubler circuit 12 is connected to the secondary side winding N ₂ , and a clamping capacitor C _{c is} connected In the tertiary side winding N ₃ .

The boost converter as shown in the first figure further includes a DC input power supply (providing an input voltage V _in ), an output capacitor C ₃ , a leakage inductance L _k , a first diode D ₁ and a first a main circuit, wherein the main circuit includes the main inductor N ₁ , a switch S and a second diode D ₂ , the DC input power source, the clamp capacitor C _c , the output capacitor C ₃ , and the main inductor N ₁ The magnetizing inductance L _m , the leakage inductance L _k and the switch S each have a first end and a second end, and the first diode D ₁ and the second diode D ₂ each have an anode and a first end of the magnetizing inductance L _m is connected to the first end of the primary side winding N ₁ and the first end of the DC input power source, and the second end of the magnetizing inductance L _m is connected to the primary side The second end of the winding N ₁ and the first end of the leakage inductance L _k , the second end of the leakage inductance L _k is connected to the first end of the switch S, the first end of the tertiary side winding N ₃ The first end of the third side winding N ₃ is connected to the anode of the first diode D ₁ , and the cathode of the first diode D ₁ is connected to the first end of the clamping capacitor C _c The clamp capacitor C _c and the second end of the second diode D ₂ of the anode, the second cathode of the diode D ₂ of the capacitor C is connected to the output of the first terminal _3, the output of the _third capacitor C The second end is connected to the second end of the DC input power source, the second end of the switch S is connected to a ground, and the clamp capacitor Cc is used to clamp a voltage across the switch S to maintain a voltage stress of the switch S. At a relatively low level, to reduce one of the voltage stress of the switch S and one of the voltage surges of the switch S, to reduce the switching loss and the conduction loss of the switch S, and the coupling inductor 11 and the multiple The voltage circuit 12 is configured to increase a boost ratio of the boost converter such that the boost ratio is not limited by a duty cycle of the boost converter. The coupled inductor 11 is a three-winding coupled inductor.

In the first figure, the boost converter further includes a load R _L , wherein the voltage doubler circuit 12 further includes a third diode D ₃ and a fourth diode D ₄ and a first capacitor C. ₁ and a second capacitor C ₂ , the load R _L , the first capacitor C ₁ and the second capacitor C ₂ each have a first and a second end, the third diode D ₃ and the fourth The diode D ₄ has an anode and a cathode, and the first end of the secondary winding N ₂ is connected to the second end of the first capacitor C ₁ and the first end of the second capacitor C ₂ , The second end of the secondary winding N ₂ is connected to the cathode of the third diode D ₃ and the anode of the fourth diode D ₄ , and the cathode of the fourth diode D ₄ is connected to the anode The first end of the first capacitor C ₁ and the first end of the load R _L , the anode of the third diode D ₃ is connected to the second end of the second capacitor C ₂ and the output capacitor C ₃ The first end of the load R _L is connected to the second end of the output capacitor C ₃ .

The following is a circuit operation mode analysis of the high-boost DC-DC converter shown in the first figure (a total of five modes).

A. Mode 1 [t ₀ -t ₁ ]

The second figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 1 as shown in the first figure. When t = t ₀ , the switch S is turned on, and the voltage across the magnetizing inductance L _m is equal to the input voltage V _in , so the magnetizing inductance L _m starts to store energy, and the current linearly increases with the slope V _in / L _m while the leakage inductance L _k Energy storage is also started with the same slope.

In this mode, the diodes D ₁ , D ₂ and D ₃ are all reverse biased, and only the diode D ₄ is forward biased. In this mode, capacitors C ₁ , C _{2 ,} and C ₃ release energy to the output load terminal, and when the main switch S is turned on, the next mode is entered.

B. Mode ₂ [t ₁ -t 2]

The third figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 2 as shown in the first figure. When t = t ₁ , the switch S is turned off, and a small amount of leakage current i _Lk starts to store the parasitic capacitance on the switch, so the voltage V _ds across the switch S increases. During this time, diodes D ₁ , D ₂ and D ₃ are reverse biased and diode D ₄ is forward biased (same as mode 1). The load energy is provided by capacitors C ₁ , C ₂ and C ₃ . When the current i _D4 through the diode D ₄ is reduced to zero, the next mode is entered.

C. Mode 3 [t ₂ -t ₃ ]

The fourth figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 3 as shown in the first figure. In this mode, the magnetizing inductance L _m releases energy to the secondary side winding N ₂ and the tertiary side winding N _{3 of the} coupled inductor 11. Therefore, the diode D _{3 is} turned on, the energy is transferred to the second capacitor C ₂ , and the diode D _{4 on the} secondary side is reverse biased. The diode D _{1 is} turned on, and the clamp capacitor C _c starts to be charged.

In mode 3, the leakage inductance energy of L _K starts to discharge the output capacitor C ₃ through the clamp capacitor C _c . Since the leakage inductance L _K releases energy, D _{2 is} turned on, and the current i _D2 through D ₂ starts to decrease slowly. . Therefore, the first and second capacitors C ₁ and C ₂ and the output capacitor C ₃ continue to supply energy to the load R _L . When the current i _Cc through the clamp capacitor C _c is released to zero, it will enter the next mode.

D. Mode 4 [t ₃ -t ₄ ]

The fifth figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 4 as shown in the first figure. In this mode, the clamp capacitor C _c begins to store the energy released by the magnetizing inductance L _m through the coupled inductor 11 , and the leakage inductance L _k continuously releases the energy to the output capacitor C ₃ , while the diode D ₄ remains in this mode. bias.

In mode 4, the diodes D ₁ , D ₂ and D _{3 are} turned on, and the currents i _D1 , i _D2 and i _D3 flowing through the three diodes gradually decrease. Furthermore, the first and second capacitors C ₁ and C ₂ and C ₃ the output capacitor supplies energy to the load continuously. In this mode, the leakage current i _Lk and the second diode current i _{D2 are} naturally reduced to zero. Therefore, the problem of reverse recovery of the second diode D ₂ can be avoided. When the energy of the leakage inductance L _k is released to zero, the next mode is entered.

E. Mode 5 [t ₄ -t ₅ ]

The sixth figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 5 as shown in the first figure. In this mode, the magnetizing inductance L _m sustained release its energy to the secondary side of the three inductors 11 via a coupling. At this time, the diodes D ₁ and D _{3 are} still turned on, but i _D1 and i _{D3 are} gradually reduced. L _m is released by the coupling inductor 11 to the clamp capacitor C _c . When the switch S is turned on again, the operation mode returns to the mode 1 to start the cycle.

The seventh diagram is a timing waveform diagram showing the high-boost DC-DC converter as shown in the first figure. In the seventh figure, the voltage V _gs between the gate and the source of the switch S, the voltage between the drain and the source V _{ds of} the switch S, the voltage across the clamp capacitor C _c V _{Cc ,} and the flow through the inductor are shown. Currents of L _m and L _k , diodes D ₁ -D ₄ and clamp capacitor C _c : i _Lm , i _Lk , i _D1 -i _D4 and i _Cc .

The eighth figure is a comparison chart showing the correspondence between the voltage boost ratio and the duty cycle of the high-boost DC-DC converter and references 1-4 as shown in the first figure. As can be seen from the eighth figure, the high boost converter proposed by the present invention is compared with reference 1 (JW Baek, MH Ryoo, TJ Kim, DW Yoo, and JS Kim, "High Boost Converter Using Voltage Multiplier Voltage," Industrial Electronics Society, 2005. IECON 2005. 31st Annual Conference of IEEE , 2005.), Reference 2 (GV Torrico-Bascope, SA Vasconcelos, RP Torrico-Bascope, FLM Antunes, DS de Oliveira, and CGC Branco, "A High Step-Up DC -C Converter Based on Three-State Switching Cell," IEEE International Symposium on Industrial Electronics , vol. 2, pp. 998-1003, July, 2006.), Reference 3 (JM Kwon and BH Kwon, "High Step-Up Active-Clamp Converter With Input-Current Doubler and Output-Voltage Doubler for Fuel Cell Power Systems," IEEE Transactions on Power Electronic , vol. 24, no. 1, pp. 108-115, Jan. 2009.), Reference 4 (KC Tseng and TJ Laing, "Novel high-efficiency step-up converter," in Proceedings IEEE Electric Power Application , vol. 151, no. 2, pp. 182-190, Mar. 2004.) and traditional flyback conversion Flyback converter The voltage step-up ratio characteristics.

The ninth figure is a comparison diagram showing the correspondence between the voltage stress and the duty cycle of the high-boost DC-DC converter and the references 1, 2 and 4 as shown in the first figure (wherein the coupling inductor 11 is followed) The number ratio is n = n ₁ = 3 and n ₂ = 1.5, where n ₁ = N ₁ / N ₂ and n ₂ = N ₃ / N ₂ ). As can be seen from the ninth figure, the voltage stress of the high-boost DC-DC converter proposed by the present invention is lower than that of Reference 1, Reference 2, Reference 4, and the conventional flyback converter.

Example:

A DC-DC boost converter comprising: a magnetizing inductor; a coupled inductor having a primary winding connected to the magnetizing inductance, a secondary winding and a tertiary winding, wherein the primary winding One of the main inductors of the converter; a voltage doubler circuit connected to the secondary side winding; and a clamp capacitor connected to the tertiary side winding.

2. The boost converter according to embodiment 1, further comprising a DC input power source, an output capacitor, a leakage inductance, a first diode and a main circuit, wherein the main circuit includes the main inductor, a switch and a second diode, the DC input power, the clamp capacitor, the output capacitor, the main inductor, the magnetizing inductance, the leakage inductance and the switch each have a first end and a second end, The first and the second diodes each have an anode and a cathode, and the first end of the magnetizing inductor is connected to the first end of the primary winding and the first end of the DC input power source, and the magnetizing inductance The second end is connected to the second end of the primary side winding and the first end of the leakage inductance, and the second end of the leakage inductance is connected to the first end of the switch, the first end of the tertiary side winding And the first end of the clamping capacitor, the second end of the tertiary winding is connected to the anode of the first diode, and the cathode of the first diode is connected to the second end of the clamping capacitor And the anode of the second diode, the cathode of the second diode is connected to the first of the output capacitors The second end of the output capacitor is connected to the second end of the DC input power source, the second end of the switch is connected to a ground, and the clamp capacitor is used to clamp one of the switches across the voltage, so that one of the switches The voltage stress is maintained at a relatively low level to reduce a voltage stress of the switch and a voltage surge of the switch, and reduce a switching loss and a conduction loss of the switch, and the coupled inductor and the voltage doubled The circuit is configured to increase a boost ratio of the boost converter such that the boost ratio is not limited by a duty cycle of the boost converter.

3. The boost converter of embodiment 1 or 2, further comprising a load, wherein the voltage doubling circuit further comprises a third and a fourth diode and a first and a second capacitor, The first and second capacitors have a first and a second end, and the third and fourth diodes each have an anode and a cathode, and the first end of the secondary winding is connected The second end of the first capacitor and the first end of the second capacitor, the second end of the secondary winding is connected to the cathode of the third diode and the anode of the fourth diode The cathode of the fourth diode is connected to the first end of the first capacitor and the first end of the load, and the anode of the third diode is connected to the second end of the second capacitor The first end of the output capacitor, and the second end of the load is coupled to the second end of the output capacitor.

4. A boost converter comprising: a coupled inductor having a primary side winding, a secondary side winding and a tertiary side winding, wherein the primary side winding is a primary inductance of the converter; a circuit connected to the secondary winding; and a clamping capacitor connected to the tertiary winding.

5. The boost converter of embodiment 4, further comprising a magnetizing inductor, a DC input power source, an output capacitor, a leakage inductance, a first diode and a main circuit, wherein the main circuit includes the a main inductor, a switch and a second diode, the DC input power, the clamp capacitor, the output capacitor, the main inductor, the magnetizing inductance, the leakage inductance and the switch each have a first end and a first The first end and the second diode each have an anode and a cathode, and the first end of the magnetizing inductance is connected to the first end of the primary winding and the first end of the DC input power source, The second end of the magnetizing inductance is connected to the second end of the primary side winding and the first end of the leakage inductance, and the second end of the leakage inductance is connected to the first end of the switch, the tertiary side winding The first end is connected to the first end of the clamping capacitor, the second end of the tertiary winding is connected to the anode of the first diode, and the cathode of the first diode is connected to the clamping capacitor The second end is connected to the anode of the second diode, and the cathode of the second diode is connected to the output The first end of the output capacitor is connected to the second end of the DC input power source, the second end of the switch is connected to a ground, and the clamp capacitor is used to clamp one of the switches across the voltage Maintaining a voltage stress of the switch at a relatively low level to reduce a voltage stress of one of the switches and a voltage surge of the switch, and reducing a switching loss and a conduction loss of the switch, and the The coupled inductor and the voltage doubling circuit are configured to increase a boost ratio of the boost converter such that the boost ratio is not limited by a duty cycle of the boost converter.

6. The boost converter of embodiment 4 or 5, further comprising a load, wherein the voltage doubling circuit further comprises a third and a fourth diode and a first and a second capacitor, The first and second capacitors have a first and a second end, and the third and fourth diodes each have an anode and a cathode, and the first end of the secondary winding is connected The second end of the first capacitor and the first end of the second capacitor, the second end of the secondary winding is connected to the cathode of the third diode and the anode of the fourth diode The cathode of the fourth diode is connected to the first end of the first capacitor and the first end of the load, and the anode of the third diode is connected to the second end of the second capacitor The first end of the output capacitor, and the second end of the load is coupled to the second end of the output capacitor.

7. A control method for a DC-DC boost converter, wherein the converter includes a magnetizing inductor, a switch, a coupled inductor coupled to the magnetizing inductor and the switch, and a coupling to the switch and the coupling The clamp capacitor of the inductor and a voltage doubler circuit connected to the coupled inductor include the steps of: utilizing the coupled inductor and the voltage doubler circuit to boost a voltage boost ratio of the converter from the Limiting the duty cycle of one of the converters; and utilizing the clamp capacitor to reduce one of the voltage stresses of the switch and one of the voltage surges of the switch, and reducing one of the switching losses and one conduction loss of the switch.

8. The method of embodiment 7, wherein the step of using the clamp capacitor further comprises the step of: clamping the voltage across the switch by the clamp capacitor to maintain the voltage stress of the switch at a relative At a lower level, the voltage stress of the switch and the voltage surge of the switch are reduced to reduce the switching loss and the conduction loss of the switch.

9. A control method for a boost converter, wherein the converter includes a magnetizing inductor, a coupled inductor coupled to the magnetizing inductor, and a voltage doubler circuit coupled to the coupled inductor, including a step of utilizing The coupled inductor and the voltage doubling circuit boost a voltage boost ratio of the converter from a duty cycle of the converter.

10. The method of embodiment 9, further comprising the step of: utilizing the clamping capacitor to reduce a voltage stress of one of the switches and a voltage surge of the switch, and reducing one of the switching losses and a conduction loss of the switch .

In summary, the present invention provides a high boost converter having a coupled inductor, a voltage doubler circuit and a clamp capacitor, which can achieve a high boost ratio without being limited by the duty cycle; the high boost proposed by the present invention The converter can reduce the number of components required for the boost converter, reduce the rated voltage of the switching component, reduce the input current ripple, and recover the leakage inductance energy of the circuit to the output capacitor, thereby improving the efficiency of the converter, so it is indeed progressive. With novelty.

Therefore, even though the present invention has been described in detail by the above-described embodiments, it can be modified by those skilled in the art, and is not intended to be protected as claimed.

11. . . Coupled inductor

12. . . Voltage doubling circuit

First: a circuit diagram showing a high-boost DC-DC converter according to a preferred embodiment of the present invention;

The second figure shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 1 as shown in the first figure;

The third figure shows the equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 2 as shown in the first figure;

Figure 4: shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 3 as shown in the first figure;

Figure 5: shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 4 as shown in the first figure;

Figure 6: shows an equivalent circuit diagram of the high-boost DC-DC converter operating in circuit operation mode 5 as shown in the first figure;

Figure 7: shows the timing waveform of the high-boost DC-DC converter as shown in the first figure;

Figure 8 is a comparison diagram showing the correspondence between the voltage boost ratio and the duty cycle of the high-boost DC-DC converter and references 1-4 as shown in the first figure;

Ninth diagram: This shows a comparison of the correspondence between the voltage stress and the duty cycle of the high-boost DC-DC converter and the references 1, 2 and 4 as shown in the first figure.

11. . . Coupled inductor

12. . . Voltage doubling circuit

Claims (10)

A DC-DC boost converter comprising: a magnetizing inductor; a coupled inductor having a primary winding connected to the magnetizing inductance, a secondary winding and a tertiary winding, wherein the primary winding is One of the main inductors of the converter; a voltage doubler circuit connected to the secondary side winding; and a clamp capacitor connected to the tertiary side winding. The boost converter of claim 1, further comprising a DC input power source, an output capacitor, a leakage inductance, a first diode and a main circuit, wherein the main circuit includes a main inductor, a switch and a second diode, the DC input power, the clamp capacitor, the output capacitor, the main inductor, the magnetizing inductance, the leakage inductance and the switch each have a first end and a second end, The first and the second diodes each have an anode and a cathode, and the first end of the magnetizing inductance is connected to the first end of the primary winding and the first end of the DC input power source, the magnetizing inductance The second end is connected to the second end of the primary side winding and the first end of the leakage inductance, and the second end of the leakage inductance is connected to the first end of the switch, the first end of the tertiary side winding And the first end of the clamping capacitor, the second end of the tertiary winding is connected to the anode of the first diode, and the cathode of the first diode is connected to the second of the clamping capacitor And the anode of the second diode, the cathode of the second diode is connected to the output capacitor The second end of the output capacitor is connected to the second end of the DC input power source, the second end of the switch is connected to a ground, and the clamp capacitor is used to clamp a crossover of the switch. The voltage stress of one of the switches is maintained at a relatively low level to reduce one of the voltage stress of the switch and one of the voltage surges of the switch, and reduce one of the switching losses and a conduction loss of the switch, and the coupled inductor And the voltage doubling circuit is configured to increase a boost ratio of the boost converter such that the boost ratio is not limited by a duty cycle of the boost converter. The boost converter of claim 2, further comprising a load, wherein the voltage multiplying circuit further comprises a third and a fourth diode and a first and a second capacitor, the load The first and the second capacitors each have a first end and a second end, the third and the second diodes each have an anode and a cathode, and the first end of the secondary winding is connected to the first end The second end of the first capacitor and the first end of the second capacitor, the second end of the secondary winding is connected to the cathode of the third diode and the anode of the fourth diode The cathode of the fourth diode is connected to the first end of the first capacitor and the first end of the load, the anode of the third diode is connected to the second end of the second capacitor and the output The first end of the capacitor, and the second end of the load is coupled to the second end of the output capacitor. A boost converter includes: a coupled inductor having a primary side winding, a secondary side winding, and a tertiary side winding, wherein the primary side winding is a primary inductance of the converter; a voltage doubler circuit Connected to the secondary winding; and a clamp capacitor connected to the tertiary winding. The boost converter of claim 4, further comprising a magnetizing inductor, a DC input power source, an output capacitor, a leakage inductance, a first diode and a main circuit, wherein the main circuit includes The main inductor, a switch and a second diode, the DC input power, the clamp capacitor, the output capacitor, the main inductor, the magnetizing inductance, the leakage inductance and the switch each have a first end and a The first end and the second diode each have an anode and a cathode, and the first end of the magnetizing inductance is connected to the first end of the primary winding and the first end of the DC input power The second end of the magnetizing inductor is connected to the second end of the primary side winding and the first end of the leakage inductance, and the second end of the leakage inductance is connected to the first end of the switch, the tertiary side winding The first end is connected to the first end of the clamping capacitor, the second end of the tertiary winding is connected to the anode of the first diode, and the cathode of the first diode is connected to the clamping capacitor The second end is connected to the anode of the second diode, and the cathode of the second diode The first end of the output capacitor, the second end of the output capacitor is connected to the second end of the DC input power source, the second end of the switch is connected to a ground, and the clamp capacitor is used to clamp one of the switches Cross-voltage, maintaining a voltage stress of the switch at a relatively low level to reduce one of the voltage stress of the switch and one of the voltage surges of the switch, and reducing one of the switch switching loss and one conduction loss, And the coupled inductor and the voltage doubling circuit are configured to increase a boost ratio of the boost converter such that the boost ratio is not limited by a duty cycle of the boost converter. The boost converter of claim 5, further comprising a load, wherein the voltage doubler circuit further comprises a third and a fourth diode and a first and a second capacitor, the load The first and the second capacitors each have a first end and a second end, the third and the second diodes each have an anode and a cathode, and the first end of the secondary winding is connected to the first end The second end of the first capacitor and the first end of the second capacitor, the second end of the secondary winding is connected to the cathode of the third diode and the anode of the fourth diode The cathode of the fourth diode is connected to the first end of the first capacitor and the first end of the load, the anode of the third diode is connected to the second end of the second capacitor and the output The first end of the capacitor, and the second end of the load is coupled to the second end of the output capacitor. A control method for a DC-DC boost converter, wherein the converter includes a magnetizing inductor, a switch, a coupled inductor coupled to the magnetizing inductor and the switch, and a connection between the switch and the coupled inductor A clamp capacitor and a voltage doubler circuit coupled to the coupled inductor include the steps of: utilizing the coupled inductor and the voltage doubler circuit to boost a voltage boost ratio of the converter from the converter Limiting one of the duty cycles; and utilizing the clamp capacitor to reduce one of the voltage stresses of the switch and one of the voltage surges of the switch, and reducing one of the switching losses and one conduction loss of the switch. The method of claim 7, wherein the step of using the clamp capacitor further comprises the step of: clamping the voltage across the switch by the clamp capacitor to maintain the voltage stress of the switch At a relatively low level, the voltage stress of the switch and the voltage surge of the switch are reduced to reduce the switching loss and the conduction loss of the switch. A control method for a boost converter, wherein the converter includes a magnetizing inductor, a coupled inductor coupled to the magnetizing inductor, and a voltage doubler circuit coupled to the coupled inductor, including a step of utilizing the coupling The inductor and the voltage doubling circuit increase the voltage boost ratio of the converter such that it is not limited by one duty cycle of the converter. The method of claim 9, further comprising the step of: using the clamp capacitor to reduce a voltage stress of one of the switches and a voltage surge of the switch, and reducing a switching loss and a conduction of the switch loss.