TW201911719A - Interleaved high-step-up zero-voltage switching dc-dc converter - Google Patents

Abstract

The invention relates to an interleaved high-step-up zero-voltage switching DC-DC converter. Primarily, the secondary windings of two coupled inductors are connected in series and capacitance-diode voltage doubling circuit architecture is guided to achieve high voltage gain. The high voltage gain is achieved with two design degrees of freedom of a coupled inductor turns-ratio and a switch-on ratio. So the high voltage gain is achieved without operating at extreme duty ratio. An active clamp circuit is added into the secondary windings of two coupled inductors, thus all switches realize zero-voltage switching soft-switching performance to reduce the switching losses and improve the conversion efficiency. The two main switch stresses are much lower than the output voltage such that the low-voltage-rated MOSFETs with low RDS(ON) are available to reduce the conduction losses. Input current ripples can be canceled out to reduce the size of the input current ripples due to the interleaved operation. The energy of the leakage inductance of the coupled inductors can be recycled, thus it can not only improve the efficiency but not cause the switch voltage surge problem. Accordingly, it is suitable for high voltage gain, high efficiency and high power applications.

Description

Isolated Zero-Voltage Switching High-Boost DC-DC Converter

The invention relates to an isolated zero-voltage switching high-boost DC-DC converter, in particular to a function that not only enables all switches to achieve zero voltage switching performance, reduces switching loss, improves efficiency, and can reduce conduction loss, and at the same time Reduce the cost of the circuit, and increase the utility characteristics in its overall implementation.

According to the United Nations Framework Convention on Climate Change [UNFCCC] 21st Meeting of the Parties [COP21] referred to as the "Paris Climate Summit", in December 2015, a historic "Paris" to replace the "Kyoto Protocol" was reached. Agreement [Paris Agreement] to respond to global warming issues. Countries will be committed to drastically reducing greenhouse gas emissions. It is hoped that by the end of this century, the global average temperature rise will not exceed 2 degrees Celsius, and the pursuit of a higher target of no more than 1.5 degrees. It is hoped that through renewable energy, countries will achieve emission reduction targets in a more effective way and pursue the "green growth" of the economy. Therefore, renewable energy must be the focus of industrial development in various countries, including solar energy, wind energy, fuel cells, hydropower, geothermal energy, tidal energy and biomass energy.

After the announcement of China's "Renewable Energy Development Regulations", we will vigorously promote the use of solar photovoltaic renewable energy. In 2012, we will promote the "Sunshine Roofing Million Block Project". This year, the Executive Yuan has approved the "Sun Optoelectronics Two-Year Promotion Plan" with the goal of 2018. The solar energy installation is 1520MW, and the annual power generation is 1.9 billion kWh, which is equivalent to the reduction of carbon in 2085 Da'an Forest Park. The roof type has a target volume of 910MW and the plane type targets 610MW. Residential solar-powered grid-connected power systems installed in Japan, Europe, and the United States have recently become fast-growing markets. In addition, since the fuel cell generates current and water through chemical reaction using hydrogen and oxygen, it is not completely pollution-free, and avoids the problem of time-consuming charging of the conventional battery. It is a new energy mode with great development prospects and is applied to vehicles. And power generation systems will significantly improve air pollution and the greenhouse effect. Therefore, in the application of renewable energy power systems, the technological development of solar power generation systems and fuel cell power generation systems is becoming more and more mature, and often plays an important role in distributed generation systems.

In general, in the power system of solar cells or renewable energy applications based on fuel cell modules, the output voltage generated by the solar cell module and the fuel cell is low voltage due to safety and reliability problems. Not exceeding 40V, in order to meet the requirements of grid-connected power generation systems or DC microgrids, this low-voltage must first be boosted to a high-voltage DC-row using a high-boost DC-DC converter. For example, for a single-phase 220V _ac grid system, this high-voltage DC line is often 380-400V _dc for DC-AC power conversion of the full-bridge inverter. In theory, a conventional boost-type [boost] converter operating at very high turn-on ratio can achieve high voltage gain, but in practice it is affected by parasitic components, and the voltage conversion ratio is limited to about 5 times or less, so when the voltage gain is as high as Approximately 10 times the practical demand, the development of a new high-boost converter topology is necessary, making high-boost DC-DC converters one of the most common research topics in the field of power electronics engineering in recent years.

Among them, the commonly used high-boost DC-DC converter has the following disadvantages:

1. Existing non-isolated boost converters must achieve high switching ratios in order to achieve high boost ratios; however, very high turn-on ratios will generate large current ripples and severe The diode reverses the recovery current problem and produces severe power loss.

2. In order to achieve a high boost ratio, the existing method can also use a two-stage step-up converter to obtain a better boosting effect, but the secondary conversion of the power may cause inefficiency and non-compliance. Efficient practical needs.

3. Interleaved high-boost converters are also proposed using voltage multiplying modules and lifting capacitors; however, the main switches of such converters are hard switching, resulting in switching losses.

In view of this, the inventor has provided an isolated zero-voltage switching high-boost DC-DC converter with years of experience in the design, development and actual production of the relevant industry, and research and improvement on the existing structure and defects. In order to achieve better practical value.

The main object of the present invention is to provide an isolated zero-voltage switching high-boost DC-DC converter, which not only enables zero-voltage switching performance of all switches, reduces switching loss, improves efficiency, and can reduce conduction loss, and at the same time Reduce the cost of the circuit, and increase the utility characteristics in its overall implementation.

The main purpose and effect of the isolated zero-voltage switching high-boost DC-DC converter of the present invention are achieved by the following specific technical means:

Mainly to make the converter at the input voltage The positive pole is connected to the first clamp capacitor First end, first coupled inductor primary side First end, second clamp capacitance First end and second coupled inductor primary side The first end of the input voltage The negative pole is respectively connected with the first main switch Second end and second main switch The second end of the first clamp capacitor The second end is connected with a first auxiliary switch The first end, the first auxiliary switch The second end and the first side of the first coupled inductor The second end is simultaneously connected to the first main switch The first end of the second clamp capacitor a second auxiliary switch is connected to the second end The first end, the second auxiliary switch The second end and the second coupled inductor primary side The second end is simultaneously connected to the second main switch First end; first coupling inductor secondary side The first end is respectively connected to the first voltage doubled body Positive electrode, second voltage doubled body Negative electrode, first output capacitor Second end and second output capacitor The first end of the first coupling inductor is connected Second end and second coupled inductor secondary side The second end is connected, the second coupled inductor secondary side The first end is respectively connected to the first voltage doubled capacitor Second end and second voltage doubled capacitor The first end is connected, the first voltage doubled capacitor The first end is respectively connected to the first voltage doubled body Negative electrode and first output diode The positive pole is connected, the second voltage doubled capacitor The second end of the second voltage and the second voltage doubled body Positive electrode and second output diode The negative pole is connected, the first output diode The negative pole and the first output capacitor First end and load The positive pole is connected, the second output diode The positive pole and the second output capacitor Second end and the load The negative electrodes are connected.

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the first main switch Forming a first main switch parasitic capacitance .

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the second main switch Forming a second main switch parasitic capacitance .

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the first coupled inductor includes a first magnetizing inductance And first leakage inductance .

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the second coupled inductor includes a second magnetizing inductance And second leakage inductance .

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the first coupled inductor primary side Secondary side of the first coupled inductor Forming a first ideal transformer, the second side of the second coupled inductor Secondary side of the second coupled inductor Forms a second ideal transformer.

A preferred embodiment of the isolated zero voltage switching high step-up DC-DC converter of the present invention, wherein the first ideal transformer and the second ideal transformer have the same turns ratio.

For a more complete and clear disclosure of the technical content, the purpose of the invention and the effects thereof achieved by the present invention, it is explained in detail below, and please refer to the drawings and drawings:

First, referring to the first diagram of the circuit diagram of the present invention, the converter (1) of the present invention is mainly applied to an input voltage. The positive pole is connected to the first clamp capacitor First end, first coupled inductor primary side First end, second clamp capacitance First end and second coupled inductor primary side The first end of the input voltage The negative pole is respectively connected with the first main switch Second end and second main switch The second end, the first main switch Forming a first main switch parasitic capacitance The second main switch Forming a second main switch parasitic capacitance The first clamp capacitor The second end is connected with a first auxiliary switch The first end, the first auxiliary switch The second end and the first side of the first coupled inductor The second end is simultaneously connected to the first main switch The first end of the second clamp capacitor a second auxiliary switch is connected to the second end The first end, the second auxiliary switch The second end and the second coupled inductor primary side The second end is simultaneously connected to the second main switch First end; first coupling inductor secondary side The first end is respectively connected to the first voltage doubled body Positive electrode, second voltage doubled body Negative electrode, first output capacitor Second end and second output capacitor The first end of the first coupling inductor is connected Second end and second coupled inductor secondary side The second end is connected, the second coupled inductor secondary side The first end is respectively connected to the first voltage doubled capacitor Second end and second voltage doubled capacitor The first end is connected, the first voltage doubled capacitor The first end is respectively connected to the first voltage doubled body Negative electrode and first output diode The positive pole is connected, the second voltage doubled capacitor The second end of the second voltage and the second voltage doubled body Positive electrode and second output diode The negative pole is connected, the first output diode The negative pole and the first output capacitor First end and load The positive pole is connected, the second output diode The positive pole and the second output capacitor Second end and the load The negative electrodes are connected.

Please refer to the second diagram of the equivalent circuit diagram of the present invention. The first coupled inductor may include a first magnetizing inductance. And first leakage inductance , the primary side of the first coupled inductor Secondary side of the first coupled inductor Forming a first ideal transformer, and the second coupled inductor may include a second magnetizing inductance And second leakage inductance , making the second coupled inductor primary side Secondary side of the second coupled inductor Forming a second ideal transformer, the first ideal transformer and the second ideal transformer have the same turns ratio, and the turns ratio defined as Because of the primary side of the first coupled inductor Primary side of the second coupled inductor Parallel connection, so that the total input current can be shared, and the interleaved operation can reduce the input current chopping; the secondary side of the first coupled inductor Secondary side of the second coupled inductor The series is connected so that the voltage gain can be increased.

The converter (1) operates in a continuous conduction mode [CCM] during use, the conduction ratio is greater than 0.5, and the first main switch And the second main switch The first auxiliary switch is operated in an interleaved manner with a working phase difference of 180 ∘ And the second auxiliary switch With the first main switch And the second main switch Complementary operation. In steady state, the converter (1) can be divided into 16 operating phases in one switching cycle according to the ON/OFF states of the switches and the diodes, and since the converter (1) The symmetry of the circuit, the following only a brief circuit action analysis of the first 8 stages, assuming:

1. The turn-on voltage drop of each of the switch and each of the diodes is zero;

2. Each of the capacitors can ignore the voltage chopping so that its capacitance voltage can be regarded as a constant;

3. The first coupling inductor and the second coupled inductor have the same turns ratio ( And the first magnetizing inductance And the second magnetizing inductance The inductance values are equal ( ), the first leakage inductance And the second leakage inductance The inductance values are equal ( ), the first magnetizing inductance And the second magnetizing inductance Far greater than the first leakage inductance And the second leakage inductance;

4. The first magnetizing inductance of the first coupled inductor The second magnetizing inductance of the second coupled inductor The current is operated in continuous conduction mode [CCM].

The linear equivalent circuit and the main component waveforms of each linear phase are as follows. Please refer to the third diagram for the steady-state waveform diagram of the main components of the present invention as shown in the following figure:

The first stage[ ]:[First main switch :ON, the second main switch :ON, the first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :OFF, first output diode :OFF, second output diode :OFF]: Please refer to the fourth diagram for the first phase of the invention, as shown in the equivalent circuit diagram. The first phase begins with The first main switch With the second main switch All are ON [on], the first auxiliary switch And the second auxiliary switch All are OFF [cutoff]. The first voltage doubled body The second voltage doubled body And the first output diode The second output diode Both are reverse biased and turned OFF. The input voltage Across the primary side of the first coupled inductor The second side of the second coupled inductor Crossing the first magnetizing inductance And the first leakage inductance And the second magnetizing inductance And the second leakage inductance Above, the current rises linearly. On the output side, the first output capacitor And the second output capacitor The load Discharge. when The first main switch When switching to OFF, this phase ends.

second stage[ ]:[First main switch :OFF, second main switch :OFF, first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :OFF, first output diode :OFF, second output diode :OFF]: Please refer to the fifth diagram for the second operational phase of the present invention as shown in the equivalent circuit diagram. The second phase begins with the first main switch. Switch to OFF. The first leakage inductance Current The first main switch The first main switch parasitic capacitance Charging, the first main switch Cross pressure Starting from zero voltage because of the parasitic capacitance of the first main switch Very small, so this time is very short. when The first main switch Cross pressure Rise to input voltage Plus the first clamp capacitor Voltage The first auxiliary switch The body diode is turned on, the first main switch Cross pressure Clamp in This phase ends.

The third phase[ ]:[First main switch :ON, the second main switch :OFF, first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :OFF, first output diode :OFF, second output diode :OFF]: Please refer to the sixth diagram for the third phase of the invention, as shown in the equivalent circuit diagram. The third phase begins with the first auxiliary switch. The body diode is turned on, the first leakage inductance Current Falling, the first leakage inductance Current Via the first auxiliary switch The body diode of the first clamp capacitor Charging. when The first clamp capacitor Voltage Rising to make the second voltage doubled body And the first output diode The second voltage doubled body when the reverse bias voltage is reduced to zero And the first output diode The transition state is ON and the phase ends.

Fourth stage [ ]:[First main switch :OFF, second main switch :ON, the first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :ON, the first output diode :ON, second output diode :OFF]: Please refer to the seventh diagram for the fourth operational phase of the present invention as shown in the equivalent circuit diagram. The fourth phase begins with the second voltage doubled diode. And the first output diode The transition state is ON. Stored in the first magnetizing inductance Energy transferred to the secondary side of the first coupled inductor The current is shunted to two paths, one of which flows through the second voltage doubled body And the second voltage doubled capacitor Another path is via the first voltage doubled capacitor The first output diode And the first output capacitor . At this time, the current is applied to the second voltage doubled capacitor Charging, the first voltage doubled capacitor Discharge and the first output capacitor Charging. On the other hand, because the secondary side current is reflected to the ideal transformer primary side of the second coupled inductor, the second leakage inductance is made. Current rise rapidly. When the first auxiliary switch When switching to ON, this phase ends.

Fifth stage [ ]:[First main switch :OFF, second main switch :ON, the first auxiliary switch :ON, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :ON, the first output diode :ON, second output diode :OFF]: Please refer to the eighth circuit diagram of the fifth operation stage of the present invention as shown in the equivalent circuit diagram. The fifth stage begins with the first auxiliary switch. Switch to ON. Because of this first auxiliary switch The body diode is turned on, so the first auxiliary switch The cross pressure is zero, so the first auxiliary switch Achieve zero voltage switching [ZVS] performance, which originally flows through the first auxiliary switch The current of the body diode is transferred to the first auxiliary switch For the first clamp capacitor Charging, the first leakage inductance Current Continue to drop when the first leakage inductance Current After falling to 0, the first leakage inductance Current Change the direction of the current. When the first auxiliary switch When switching to OFF, this phase ends.

Sixth stage [ ]:[First main switch :OFF, second main switch :ON, the first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :ON, the first output diode :ON, second output diode :OFF]: Please refer to the ninth diagram of the sixth operational phase of the present invention as shown in the equivalent circuit diagram. The sixth phase begins with the first auxiliary switch. Switch to OFF. The first leakage inductance And the first main switch parasitic capacitance Start to generate resonance and store the parasitic capacitance of the first main switch The energy is transferred to the first leakage inductance by resonance The first main switch Cross pressure Start resonance drop and store the parasitic capacitance of the first main switch Energy transfer to the first leakage inductance on. When, the second main switch Cross pressure Down to zero, the first main switch The body diode begins to conduct and this phase ends.

Seventh stage [ ]:[First main switch :OFF, second main switch :ON, the first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :ON, the first output diode :ON, second output diode :OFF]: Please refer to the tenth figure. The equivalent circuit diagram of the seventh operation stage of the present invention is shown in the seventh stage. The seventh stage starts from the first main switch. The body diode is turned on, the first main switch Cross pressure Zero, the first main switch The condition of zero voltage switching [ZVS] is established. When, the first main switch When switching to ON, the first main switch The ZVS performance is achieved and this phase ends.

The eighth stage [ ]:[First main switch :ON, the second main switch :ON, the first auxiliary switch :OFF, second auxiliary switch :OFF, first voltage doubled body :OFF, second voltage doubled body :ON, the first output diode :ON, second output diode :OFF]: Please refer to the eleventh figure. The equivalent circuit diagram of the eighth operation stage of the present invention is shown in the eighth stage. The first main switch Switch to ON, and the second main switch Keep ON, the first leakage inductance Current Rising, when the first leakage inductance Current Less than the first magnetizing inductance Current , which is The first magnetizing inductance The stored energy is transferred to the secondary side by the coupled inductor. Therefore the second voltage doubled body And the first output diode Still conducting, the second voltage doubled body Current Falling, the second voltage doubled capacitor Charging, the first output diode Current Falling, the first output capacitor Charging. when , the leakage inductance current rises to At this time, the second voltage doubled body Current And the first output diode Current Down to zero, the second voltage doubled body And the first output diode Switching to zero with zero current switching [ZCS], the first magnetizing inductance And the first leakage inductance It is charged again by the input voltage, and this phase ends and enters the next half of the switching cycle.

In the 8 stages of the second half of the switching period of the converter (1), due to the symmetry of the circuit, the analysis of the operation of the last 8 stages is similar [please refer to the twelfth to the nineteenth pictures together], detail The analysis is omitted here.

The steady-state characteristic analysis of the converter (1) is performed as follows: In order to simplify the analysis, the transient characteristics of each switch and each of the diodes and the extremely short time are ignored. At the same time, ignore the transient phase with very short time, including the second, third, fourth, sixth, seventh, ten, eleventh, twelfth, fourteenth, fifteenth and sixteenth phases, only considering the first, fifth, eighth and ninth Thirteen stages. All capacitors are large enough to ignore capacitive voltage chopping so that the capacitor voltage can be considered constant.

Voltage gain:

In the first, eighth, ninth, and thirteenth stages, the first magnetizing inductance Cross pressure

(1)

In the fifth stage, the first magnetizing inductance Cross pressure

(2)

According to the principle of volt-second balance, the average voltage of the inductor voltage in a switching cycle is zero, ignoring the blind time with a small proportion of the cycle, so

(3)

Finishing (3) is available

(4)

In the interleaved mode of operation, the circuit action analysis of the lower half of the converter is similar to the above, for the second magnetizing inductance , applying the volt-second balance theorem is equally available

(5)

The second voltage doubled capacitor on the secondary side of the coupled inductor Voltage It can be obtained by decoupling the primary side voltage of the coupled inductor to the secondary side voltage. In the fifth stage, the first main switch :OFF, second main switch :ON, the second voltage doubled body And the first output diode Conduction, the second voltage doubled capacitor Voltage for

(6)

In the thirteenth stage, the first main switch: ON, the second main switch :OFF, and the first voltage doubled body And the second output diode Conduction, the first voltage doubled capacitor Voltage for

(7)

The first output capacitor Voltage for

(8)

The second output capacitor Voltage for

(9)

The load Total output voltage for

(10)

Therefore the voltage gain of the converter (1) for

(11)

when Voltage gain Coupling coefficient with different coupled inductors [k=1, 0.95, 0.9] The influence between each other is very small [please refer to the graph of voltage gain and conduction ratio and coupling coefficient of the present invention as shown in the twenty-fifth figure). If the leakage inductance is ignored, the coupling coefficient , the ideal voltage gain is

(12)

From the above formula, the voltage gain is known, and the coupled inductor turns ratio And conduction ratio Two design degrees of freedom. The converter (1) can achieve a high step-up ratio by appropriately designing the turns ratio of the coupled inductor without having to operate at a very large turn-on ratio. Corresponding to the coupled inductor turns ratio And conduction ratio The voltage gain curve is a graph of the voltage gain and the turn-on ratio and the coupled inductor turns ratio of the present invention as shown in the twenty-first embodiment. When the ratio is , When the voltage gain is 10 times; , At the time, the voltage gain is 30 times.

Voltage stress of the switching element:

The first main switch The second main switch Voltage stress is

(13)

Since the power switching stress of the conventional interleaved boost converter is V _o and the switching voltage stress of the converter (1) is relatively small, only 1/4 n times the output voltage, the low rated withstand voltage can be used. Lower R _{ds (ON)} MOSFETs reduce switch conduction losses.

According to the above circuit action analysis results, the IsSpice simulation software and the implementation results are verified. Set the relevant parameters of the converter (1): input power 36V, output voltage 380V, maximum output power 1000W, switching frequency 50kHz, The following is an examination of the characteristics of the converter (1) with analog waveforms and actual results [please refer to the twenty-second diagram of the analog circuit diagram of the present invention again]:

A. Verification of steady-state characteristics: Please refer to the analog waveform diagram of the switch drive signal, input voltage and output voltage of the present invention as shown in the twenty-third figure to verify the steady-state characteristic of the converter (1), full load 500W When you know , , the conduction ratio is approximately , in accordance with the formula of (12) voltage gain.

B. Verifying the switch voltage stress: Please refer to the twenty-fourth figure for the analog switch waveform diagram of the main switch across the present invention and the twenty-fifth figure. The fuzzy waveform diagram of the auxiliary switch across the voltage of the present invention is shown in the figure. Converter (1) output voltage The first main switch The second main switch The voltage stress is 100V, the first auxiliary switch The second auxiliary switch The voltage stress is 98V. Verify that the converter (1) switch has the advantage of low voltage stress.

C. Verify that both the main switch and the auxiliary switch can achieve ZVS operation: Please refer to the twenty-sixth drawing of the main switch of the present invention for driving signals and voltage across the analog waveform diagram, and the twenty-seventh figure. The analog waveform enlarged view of the switch switching instant, the twenty-eighth figure shows the enlarged view of the analog waveform of the second main switch switching instant of the present invention, and the first main switch can be known when the full load is 1000W. And the second main switch The first main switch before switching to ON Cross pressure And the second main switch Cross pressure All have been reduced to zero, so the ZVS operation is achieved; please refer to the twenty-ninth aspect of the present invention, the driving signal and the cross-voltage analog waveform diagram of the auxiliary switch, and the thirty-first diagram of the first auxiliary switch of the present invention. Analog waveform enlargement diagram, FIG. 31 is an enlarged view of the analog waveform of the second auxiliary switch switching instant of the present invention, and the first auxiliary switch can be known when the load is 1000 W at full load. And the second auxiliary switch The first auxiliary switch before switching to ON Cross pressure And the second auxiliary switch Cross pressure Both have dropped to zero, so ZVS operation is achieved.

D. Verification of low input chopping current performance and CCM operation: Please refer to the thirty-second diagram of the leakage inductance current and total input current analog waveform diagram of the present invention, and the first leakage inductance can be known. Current And the second leakage inductance Current The chopping current is about 48A, and the input current The chopping current is only about 20.8A, so the interleaved operation has the effect of reducing the input chopping current.

E. Verifying the output capacitor voltage: Please refer to the thirty-third figure for the voltage waveform of the voltage doubling capacitor and the output capacitor of the present invention. The first voltage doubling capacitor is shown. Voltage And the second voltage doubled capacitor Voltage Approximately equal to 95V, the first output capacitor Voltage And the second output capacitor Voltage Approximately equal to 190V, the simulation and implementation results are consistent with the analysis results. Verify the correctness of the theoretical analysis. Please refer to the voltage waveform diagram of the clamp capacitor of the present invention as shown in the thirty-fourth figure, the first clamp capacitor Voltage And the second clamp capacitor Voltage It is approximately equal to 55V, which is in accordance with the derivation result of formula (4).

From the above, the implementation description of the present invention shows that the present invention has the following advantages in comparison with the prior art means:

1. This case utilizes the active clamp circuit to achieve zero voltage switching performance for all switches, reducing switching losses and improving efficiency.

2. In this case, the voltage multiplying module composed of the coupled inductor is used to increase the voltage gain. The switching voltage stress is much lower than the output voltage. A power switch with a small on-resistance can be used to reduce the conduction loss and improve the efficiency.

3. This case uses interleaved operation to make the input current ripple cancel and reduce the input current ripple, which can reduce the number of capacitors at the power supply terminal and reduce the circuit cost.

However, the above-described embodiments or drawings are not intended to limit the structure or the use of the present invention, and any suitable variations or modifications of the invention will be apparent to those skilled in the art.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific structure disclosed therein has not been seen in similar products, nor has it been disclosed before the application, and has completely complied with the provisions of the Patent Law. And the request, the application for the invention of a patent in accordance with the law, please forgive the review, and grant the patent, it is really sensible.

(1)‧‧‧ converter

First picture: circuit diagram of the invention

Second figure: equivalent circuit diagram of the present invention

Third figure: Steady-state waveform diagram of the main components of the present invention

Fourth figure: equivalent circuit diagram of the first operation stage of the present invention

Figure 5: Equivalent circuit diagram of the second operation stage of the present invention

Figure 6: Equivalent circuit diagram of the third operation stage of the present invention

Figure 7: Equivalent circuit diagram of the fourth operation stage of the present invention

Figure 8: Equivalent circuit diagram of the fifth operation stage of the present invention

Ninth diagram: equivalent circuit diagram of the sixth operation stage of the present invention

Figure 11: Equivalent circuit diagram of the seventh operation stage of the present invention

Eleventh figure: equivalent circuit diagram of the eighth operation stage of the present invention

Twelfth figure: equivalent circuit diagram of the ninth operation stage of the present invention

Thirteenth figure: equivalent circuit diagram of the tenth operation stage of the present invention

Figure 14: Equivalent circuit diagram of the eleventh operation stage of the present invention

Figure 15: Equivalent circuit diagram of the twelfth operation stage of the present invention

Figure 16: Equivalent circuit diagram of the thirteenth operation stage of the present invention

Figure 17: Equivalent circuit diagram of the fourteenth operation stage of the present invention

Figure 18: Equivalent circuit diagram of the fifteenth operation stage of the present invention

Figure 19: Equivalent circuit diagram of the sixteenth operation stage of the present invention

Figure 20: Graph of voltage gain and conduction ratio and coupling coefficient of the present invention

Twenty-first graph: graph of voltage gain and conduction ratio and coupled inductor turns ratio of the present invention

Twenty-second diagram: schematic diagram of the analog circuit of the present invention

Twenty-third graph: analog waveform diagram of the switch drive signal, input voltage and output voltage of the present invention

Figure 24: Analog waveform diagram of the main switch cross-over voltage of the present invention

Figure 25: Fuzzy waveform diagram of the auxiliary switch across the pressure of the present invention

Figure 26: Driving signal and cross-voltage analog waveform diagram of the main switch of the present invention

Figure 27: enlarged waveform of the analog waveform of the first main switch switching instant of the present invention

Twenty-eighth drawing: an enlarged view of the analog waveform of the second main switch switching instant of the present invention

Twenty-ninth figure: driving signal and cross-voltage analog waveform diagram of the auxiliary switch of the present invention

Thirty-fifth: enlarged waveform of the analog waveform of the first auxiliary switch switching instant of the present invention

The thirty-first figure: an enlarged view of the analog waveform of the second auxiliary switch switching instant of the present invention

Figure 32: Analog waveform diagram of leakage inductance current and total input current of the present invention

Thirty-third figure: simulation diagram of voltage waveform of double voltage capacitor and output capacitor of the present invention

Figure 34: Simulation diagram of the voltage waveform of the clamp capacitor of the present invention

Claims (7)

An isolated zero-voltage switching high-boost DC-DC converter, which mainly causes the converter to input voltage The positive pole is connected to the first clamp capacitor First end, first coupled inductor primary side First end, second clamp capacitance First end and second coupled inductor primary side The first end of the input voltage The negative pole is respectively connected with the first main switch Second end and second main switch The second end of the first clamp capacitor The second end is connected with a first auxiliary switch The first end, the first auxiliary switch The second end and the first side of the first coupled inductor The second end is simultaneously connected to the first main switch The first end of the second clamp capacitor a second auxiliary switch is connected to the second end The first end, the second auxiliary switch The second end and the second coupled inductor primary side The second end is simultaneously connected to the second main switch First end; first coupling inductor secondary side The first end is respectively connected to the first voltage doubled body Positive electrode, second voltage doubled body Negative electrode, first output capacitor Second end and second output capacitor The first end of the first coupling inductor is connected Second end and second coupled inductor secondary side The second end is connected, the second coupled inductor secondary side The first end is respectively connected to the first voltage doubled capacitor Second end and second voltage doubled capacitor The first end is connected, the first voltage doubled capacitor The first end is respectively connected to the first voltage doubled body Negative electrode and first output diode The positive pole is connected, the second voltage doubled capacitor The second end of the second voltage and the second voltage doubled body Positive electrode and second output diode The negative pole is connected, the first output diode The negative pole and the first output capacitor First end and load The positive pole is connected, the second output diode The positive pole and the second output capacitor Second end and the load The negative electrodes are connected. The isolated zero voltage switching high-boost DC-DC converter according to claim 1, wherein the first main switch Forming a first main switch parasitic capacitance . The isolated zero voltage switching high-boost DC-DC converter according to claim 1, wherein the second main switch Forming a second main switch parasitic capacitance . The isolated zero voltage switching high-boost DC-DC converter according to claim 1, wherein the first coupled inductor includes a first magnetizing inductance And first leakage inductance . The isolated zero voltage switching high-boost DC-DC converter according to claim 1, wherein the second coupled inductor includes a second magnetizing inductance And second leakage inductance . The isolated zero-voltage switching high-boost DC-DC converter according to claim 1, wherein the first coupled inductor primary side Secondary side of the first coupled inductor Forming a first ideal transformer, the second side of the second coupled inductor Secondary side of the second coupled inductor Forms a second ideal transformer. The isolated zero-voltage switching high-boost DC-DC converter according to claim 6, wherein the first ideal transformer and the second ideal transformer have the same turns ratio.