A zero-voltage-switching DC-DC boost converter

Abstract

A zero-voltage-switching DC-DC boost converter, comprising an input end and an output end, and including three switching tubes S 1 ‑ S 3 , a first inductor L 1 , a second inductor L 2 , an output capacitor c o , a power diode D O ; The input end includes a rechargeable energy storage battery V B and a DC source V in , and the battery and the DC source supply energy to the entire circuit; for the said output end, a resistive load R is connected in parallel with the output capacitor c o ; The converter proposed by the present invention uses fewer switches, can effectively reduce the switching loss, improve the conversion efficiency, has a simple and compact structure, fewer magnetic components, adopts the zero-voltage-switching technology, improves the efficiency of the circuit, and realizes the optimization of the overall function of the converter.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and particularly relates to a zero-voltage-switching DC-DC boost converter. Background Art

[0002] With the development of power electronics technology, multi-input DC-DC converters have attracted the attention of many researchers due to their advantages such as the ability to centrally control multiple power ports simultaneously, low cost, high power density, high efficiency, and compact structure. Traditional isolated DC-DC converters are generally obtained by combining magnetic coupling with full-bridge, half-bridge, and resonant topologies, etc., and often use multi-winding transformers. PWM secondary-side phase-shift control and zero-voltage switching on both the primary side and the secondary side can share improved power devices, with relatively high performance, but many power circuit components are used.

[0003] To further improve the system efficiency, non-isolated multi-input DC-DC converters have increasingly attracted people's attention. Non-isolated multi-input DC-DC converters are generally obtained by using a DC link or an integrated method. The proposed high-boost three-port DC-DC converter integrates new energy and battery energy through two auxiliary coupled inductors as voltage gain expansion units, but its switching converter cannot achieve soft switching, and there are many power electronic devices used in the circuit implementation. There is still room for improvement in terms of the size and economy of the converter structure. Summary of the Invention

[0004] To overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a zero-voltage-switching DC-DC boost converter, which can mix and utilize clean new energy, and combines a hybrid bidirectional boost converter and a unidirectional boost converter. The bidirectional boost converter is powered by a rechargeable battery V B and the unidirectional boost converter is powered by a DC source. The circuit includes three switching tubes, a power diode, two inductors, and an output filter capacitor. The realization of soft switching of the switching tubes can be achieved without using other auxiliary circuits; the topological structure adopted by the converter is simple and compact, with fewer power electronic devices used, and the power of the storage element ports can flow bidirectionally, with relatively high efficiency.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A zero-voltage-switching DC-DC boost converter, comprising an input terminal, an output terminal, a first switch S 1 , a second switch S 2 , a third switch S 3 , a first inductor L 1 , a second inductorL 2 , an output capacitor c o and a power diode D o ;

[0007] The input terminal mentioned above includes a storage battery V B and a DC power source V in ; The output terminal is connected with a resistive load R, Resistive load R is in parallel with the output capacitor c o ; The positive electrode of the storage battery V B is connected to the negative electrode of the DC power source L 1 through a first inductor V in ; The positive electrode of the DC power source V in is connected to the anode of the power diode L 2 through a second inductor D 0 ; The negative electrode of the storage battery V B is connected to the source electrode of the first switch S 1 ; The drain electrode of the first switch S 1 is connected to the source electrode of the second switch S 2 and then connected to the negative electrode of the DC power source V in ; The drain electrode of the second switch S 2 is connected to the cathode of the power diode D 0 ; The source electrode of the third switch S 3 is connected to the positive electrode of the storage battery V B ; The drain electrode of the third switch S 3 is connected to the anode of the power diode D 0 ; One end of the output capacitor c o is connected to the cathode of the power diode D 0 ; The other end of the output capacitor c o is connected to the negative electrode of the storage battery V B ; ResistorR In parallel with the output capacitor c o in parallel.

[0008] The first switch mentioned above S 1 and the second switch S 2 and the third switch S 3 are all MOS transistor switches.

[0009] The first switch mentioned above S 1 and the second switch S 2 and the third switch S 3 each have a parallel fast recovery diode and a parallel-connected capacitor; the model of the recovery diode is IDW100E60.

[0010] The first switch mentioned above S 1 and the second switch S 2 and the third switch S 3 have a switching frequency higher than their cut-off frequency.

[0011] The storage battery VB and the DC source mentioned above V in are two energy supply units that supply electrical energy to the entire circuit.

[0012] The storage battery mentioned above V B has a voltage level greater than that of the DC source V in in voltage level.

[0013] The converter mentioned above further includes a DSP chip and a PWM driver; the DSP chip is connected to the PWM driver; the output port of the PWM driver is connected to the switching tube.

[0014] The control method of the converter mentioned above includes the following steps:

[0015] The first switch mentioned above S 1 and the second switch S 1 2 conduct complementarily, and when the first switch S 1 is turned off, the third switch S 3 conducts.

[0016] The control method of the converter mentioned above includes the following steps:

[0017] The first switch described above S 1 and the second switch S 2 and the third switch S 3 are all controlled for on / off by using the PWM pulse driving method.

[0018] For the converter described above, its control method includes the following steps:

[0019] The first switch described above S 1 and the second switch S 2 and the third switch S 3 are switched in the PWM mode. The PWM pulse wave has two independent duty cycles; the PWM pulse wave with the first duty cycle d 1 is used to adjust the output voltage of the converter V O , and the PWM pulse wave with the second duty cycle d 2 is used to control the desired power of the unidirectional input power storage battery V B .

[0020] For the converter described above, its control method includes the following steps:

[0021] By switching the switching tubes through the DSP chip and the PWM driver, the circuit can operate in two different cases: d 1 + d 2 > 1 or d 1 + d 2 < 1. Each case has a switching period composed of nine modes.

[0022] The beneficial effects of the present invention are:

[0023] Compared with the prior art, a zero-voltage-switching DC-DC boost converter of the present invention uses a Mosfet as a switching device to achieve high efficiency and reliability. This topology takes advantage of the merits of the Mosfet and an external fast-recovery diode, minimizing power loss to a great extent, achieving high efficiency, and improving the stability of the power converter system. The switching device of the proposed converter switches in a PWM manner and has two independent duty cycles, and the control requirements for the output voltage of the converter and the power extracted from the unidirectional input port are relatively simple. This converter has a simple and compact structure, uses fewer switching devices and inductors, and has high efficiency. Description of the Drawings

[0024] Figure 1 is the circuit diagram of the present invention.

[0025] Figure 2 is the equivalent circuit diagram of eight operating modes 1 of the present invention.

[0026] Figure 3 is the equivalent circuit diagram of eight operating modes 2 of the present invention.

[0027] Figure 4 is the equivalent circuit diagram of eight operating modes 3 of the present invention.

[0028] Figure 5 is the equivalent circuit diagram of eight operating modes 4 of the present invention.

[0029] Figure 6 is the equivalent circuit diagram of eight operating modes 5 of the present invention.

[0030] Figure 7 is the equivalent circuit diagram of eight operating modes 6 of the present invention.

[0031] Figure 8 is the equivalent circuit diagram of eight operating modes 7 of the present invention.

[0032] Figure 9 is the equivalent circuit diagram of eight operating modes 8 of the present invention.

[0033] Figure 10 is the equivalent circuit diagram of eight operating modes 9 of the present invention.

[0034] Figure 11 is the equivalent circuit diagram of eight operating modes 10 of the present invention.

[0035] Figure 12 is the equivalent circuit diagram of eight operating modes 11 of the present invention.

[0036] Figure 13 is the equivalent circuit diagram of eight operating modes 12 of the present invention.

[0037] Figure 14 is the equivalent circuit diagram of the eight operating modes 13 of the present invention.

[0038] Figure 15 is the equivalent circuit diagram of the eight operating modes 14 of the present invention.

[0039] Figure 16 is the equivalent circuit diagram of the eight operating modes 15 of the present invention.

[0040] Figure 17 is the equivalent circuit diagram of the eight operating modes 16 of the present invention.

[0041] Figure 18 is the equivalent circuit diagram of the eight operating modes 17 of the present invention.

[0042] Figure 19 is the equivalent circuit diagram of the eight operating modes 18 of the present invention. Detailed implementation manners

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present application.

[0044] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, products, or devices.

[0045] The embodiment of the present invention provides a zero-voltage-switching DC-DC boost converter, where the input DC source V in should have a voltage level lower than that of the storage battery V B voltage ( V B > V in ). The third switch S 3 turns on with zero voltage. At the same time, the converter power diode D0 turns off conduction at zero current to relieve its reverse recovery problem. The converter inductor current I L1 and I L2 is in continuous conduction mode. Refer to Figure 1 , a zero-voltage-switching DC-DC boost converter, comprising an input terminal and an output terminal, and including three switching transistors S 1 - S 3 , a first inductor L 1 , a second inductor L 2 , an output filter capacitor c o , and a power diode D o .

[0046] Specifically, the input terminal includes a storage battery V B and a DC source V in ; the output terminal is connected to a resistive load R , and the resistive load R is connected in parallel with the output capacitor c o ; the positive electrode of the storage battery V B is connected to the negative electrode of the DC source L 1 through the first inductor V in ; the positive electrode of the DC source V in is connected to the anode of the power diode L 2 through the second inductor D 0 ; the negative electrode of the storage battery V B is connected to the source of the first switch S 1 ; the drain of the first switch S 1 is connected to the source of the second switch S 2 and then connected to the negative electrode of the DC source V in ; the drain of the second switch S 2 is connected to the cathode of the power diode D 0 ; the third switch S 3 ​The source electrode is connected to the storage battery V B , and the third switch S 3 has its drain electrode connected to the anode of the power diode D 0 . One end of the output capacitor c o is connected to the cathode of the power diode, and the other end of the output capacitor c o is connected to the negative electrode of the storage battery V B . The resistor R is in parallel with the output capacitor c o .

[0047] Preferably, the first switch S 1 , the second switch S 2 , and the third switch S 3 are all MOS transistor switches.

[0048] Preferably, the first switch S 1 , the second switch S 2 , and the third switch S 3 are all provided with a fast recovery diode of model IDW100E60 connected in parallel externally and a capacitor connected in parallel.

[0049] Preferably, the switching frequencies of the first switch S 1 , the second switch S 2 , and the third switch S 3 are all higher than their cut-off frequencies.

[0050] Specifically, there are two energy supply units in the entire circuit, namely the storage battery V B and the DC power source V in .

[0051] Preferably, the voltage level of the storage battery VB in the entire circuit is greater than that of the DC power source V in .

[0052] The described zero-voltage-switching DC-DC boost converter includes a DSP chip and a PWM driver; the DSP chip is connected to the PWM driver; the output port of the PWM driver is connected to the switching tube. The on / off of the switching tube is controlled by the DSP chip and the PWM driver.

[0053] Specifically, the first switch S 1 and the second switch S 2 conduct complementarily, and when the first switch S 1 is turned off, the third switch S 3 is turned on.

[0054] The first switch S 1 and the second switch S 2 and the third switch S 3 switch in a PWM manner, and the PWM pulse wave has two independent duty cycles. The PWM pulse wave with the first duty cycle d 1 is used to regulate the output voltage V O of the converter, and the PWM pulse wave with the second duty cycle d 2 is used to control the desired power of the unidirectional input power storage battery V B .

[0055] It can be understood that in the proposed zero-voltage-switching DC-DC boost converter, the control of all switching tubes adopts the PWM scheme and is switched through two independent duty cycles d 1 and d 2 . The first switch S 1 and the second switch S 2 are turned on and off complementarily with a certain dead zone and conduct according to the pulse waveform of the first duty cycle d 1 . At the same time, the third switch S 3 is controlled by the pulse wave of the second duty cycle d 2 of the converter. At the same time, the power extracted by the converter from the DC source V in is regulated. The third switch S 3 is turned on when the first switch S1 Connect at the moment of disconnection.

[0056] Specifically, according to the value of the duty cycle of the drive pulse wave received by the converter switch, the proposed converter can operate under two different operating conditions, namely d 1 + d 2 > 1 or d 1 + d 2 < 1. In addition, the switching period of each operating condition consists of nine operating modes. Specifically, it includes eighteen operating modes.

[0057] See Figures 2 to 19 , the zero - voltage - switched DC - DC boost converter of this embodiment includes eighteen operating modes.

[0058] At the beginning d 1 + d 2 > 1 before the first operating condition, the first switch S 1 conducts, the second switch S 2 and the third switch S 3 turn off, and the body diode of the third switch S 3 is conducting the negative current flowing through the second inductor I L2 .

[0059] Mode 1: d 1 + d 2 The first operating mode under the condition of > 1. In this mode, the third switch S 3 turns on with zero voltage, the first switch S 1 , the second switch S 2 turn off. At this time, the converter obtains a higher power level from the DC source V in , the positive current flowing through the first inductor L 1 and the positive current flowing through the second inductor I L1 charge the first capacitor I L2 1, and discharge the second capacitor c 2 at the same time. This process continues until the second switch c 2 S ​The second diode D 2 The moment when the forward bias conducts current. Mode 1 circuit is as follows Figure 2 shown.

[0060] Mode 2: d 1 + d 2 >1, the second operation mode. In this mode, the third switch S 3 Open, first switch S 1 Completely turned off, no device involved in current transfer, flows through the first inductor L 1 Positive current I L1 and the positive current flowing through the second inductor I L2 Flow through the second switch S 2 The second diode D 2 The last moment of this process is the second switch S 2 Zero voltage switching is ready, and the second switch S 2 There is no voltage at both ends. Mode 2 circuit is as follows Figure 3 shown.

[0061] Mode 3: d 1 + d 2 >1, the third operating mode. In this mode, the third switch S 3 Still on, second switch S 2 Zero voltage turn-on, first inductor L 1 Energy stored in batteries V B , First Inductor L 1 , Second switch S 2 and output capacitor c o The series circuit discharges. At the same time, the second inductor L 2 Through the battery V B , the third switch S 3 , the second inductor L 2 , DC sourceV in and the second switch S 2 and the output capacitor are connected in series to charge the loop. At the last moment of this mode, the current flowing through the first inductor c o reaches the minimum value I L1 . The current flowing through the second inductor I L1min reaches the maximum value I L2 . The second switch I L2max carries current S 2 . The circuit of Mode 3 is as shown in I 2 . Figure 4 shown

[0062] Mode 4: d 1 + d 2 > 1. In the fourth operating mode under this condition, the third switch S 3 is turned on, and the first switch S 1 , the second switch S 2 are turned off. The combined current of the current IL2 flowing through the second inductor and the current IL1 flowing through the first inductor charges the external second capacitor S 2 of the second switch until the external first diode c 2 S 1 of the first switch D 2 becomes forward-biased and starts to conduct. This process lasts for a very short time. The circuit of Mode 4 is as shown in Figure 5 shown

[0063] Mode 5: d 1 + d 2 > 1. In the fifth operating mode under this condition, the third switch S 3 is turned on, and the external first diode S 1 of the first switch D 1 conducts the current flowing through the second inductor I L2 and the current flowing through the first inductor I L1The synthetic current is for the first switch S 1 provides the condition for the early zero-voltage turn-on of the second switch. At this moment, the second switch S 2 and the first switch S 1 The dead-time interval between them has passed. The mode 5 circuit is as Figure 6 shown.

[0064] Mode 6: d 1 + d 2 The sixth operating mode under the condition of >1. In this mode, the first switch S 1 conducts with zero voltage, and the first inductor L 1 charges in the circuit loop composed of the battery V B the first inductor L 1 and the first switch S 1 in series. The second inductor L 2 slowly discharges through the circuit loop composed of the battery V B the third switch S 3 the second inductor L 2 the DC source V in and the first switch S 1 The mode 6 circuit is as Figure 7 shown.

[0065] Mode 7: d 1 + d 2 The seventh operating mode under the condition of >1. In this mode, the third switch S 3 is turned off, and the current I L2 flowing through the second inductor c charges the third capacitor D O The anode voltage of the power diode D O rises until the power diode I S3 becomes forward-biased and the current Figure 8 shown.

[0066] Mode 8: d 1 + d 2 The eighth operating mode under the condition of >1. In this mode, the second switch S 2 and the third switch S 3 are turned off, and the first switch S 1 is turned on. The power diode D O conducts the current flowing through the second inductor L 2 . The second inductor I L2 discharges through the circuit loop composed of the first switch L 2 , the DC source S 1 , the second inductor V in , the power diode L 2 and the output capacitor D O . At the same time, the first inductor c o is charged in the circuit loop including the battery L 1 , the first inductor V B and the first switch L 1 . This operating mode continues until the current flowing through the power diode S 1 reaches zero, at which time the diode I DO turns off with zero current. The circuit of Mode 8 is as shown in D O . Figure 9 as shown

[0067] Mode 9: d 1 + d 2 The ninth operating mode under the condition of >1. In this mode, the second switch S 2 and the third switch S 3 are turned off, the first switch S 1 is turned on. At this time, the externally added third diode of the third switch S 3 D 3 ​By including a storage battery V B , a third diode D 3 , a second inductor L 2 , a DC source V in and a first switch S 1 , a circuit loop conducts a negative current flowing through the second inductor L 2 to prepare for the zero-voltage turn-on of the third switch S 3 in advance. At the same time, the current L 1 flowing through the first inductor I L1 still increases through the circuit loop formed by the series connection of the storage battery V B , the first inductor L 1 and the first switch S 1 . The mode 9 circuit is as shown in Figure 10 .

[0068] Second operating condition d 1 + d 2 <1This operating condition occurs at a lower power level extracted from the DC source V in . At the starting moment of this operating condition, the first switch S 1 conducts, the second switch S 2 and the third switch S 3 are turned off, and the externally added third diode S 3 of the third switch D 3 conducts the current L 2 flowing through the second inductor I L2 .

[0069] Mode 10: d 1 + d 2 <1The first operating mode under the operating condition. In this mode, the first switch S 1 , the second switch S 2 are turned off, and the third switch S3 Zero-voltage turn-on, current flowing through the first inductor L 1 current I L1 and the current flowing through the second inductor L 2 current I L2 The combined current of flows charges the first capacitor c 1, while discharging the second capacitor c 2. This process continues until the externally applied second diode of the second switch S 2 is forward-biased. This process lasts for a very short time. The circuit diagram of Mode 10 is as D 2 shown Figure 11 shown

[0070] Mode 11: d 1 + d 2 The second operating mode under the condition of <1. In this mode, the second switch S 2 is not turned on, and the externally applied second diode of the second switch S 2 starts to conduct the current flowing through the first inductor D 2 current L 1 current I L1 and the current flowing through the second inductor L 2 current I L2 combined current. This process continues until after the dead-time interval when the first switch S 1 and the second switch S 2 alternately conduct, preparing for the zero-voltage turn-on of the second switch S 2 The circuit of Mode 11 is as Figure 12 shown

[0071] Mode 12: d 1 + d 2 The third operating mode under the condition of <1. In this mode, the first switch S 1 is turned off, the third switch S 3 is still turned on, and the second switch S 2 is zero-voltage turned on, and the first inductorL 1 The stored energy is released through a circuit loop composed of a storage battery V B , a first inductor L 1 , a second switch S 2 and an output capacitor c o . At the same time, the storage battery V B , a third switch S 3 , a second inductor L 2 , a DC source V in , a second switch S 2 and an output capacitor c o form a circuit loop to charge the second inductor L 2 . At the end of this time interval, the current L 1 flowing through the first inductor I L1 and the current L 2 flowing through the second inductor I L2 become positive and are conducted by the second switch S 2 . The mode 12 circuit is as shown in Figure 13 .

[0072] Mode 13: d 1 + d 2 The fourth operating mode under the condition of <1. In this mode, the first switch S 1 , the third switch S 3 is turned off, the second switch S 2 is turned on, the current L 2 flowing through the second inductor I L2 charges the externally added third capacitor of the third switch c 3, the anode voltage of the power diode D O rises, and this process continues until the power diode D O becomes forward-biased and the current I S3Reach zero, and then start the next operating mode. The circuit of Mode 13 is as Figure 14 shown.

[0073] Mode 14: d 1 + d 2 The fifth operating mode under the condition of <1. In this mode, only the second switch S 2 turns on, and the power diode D O starts to conduct the current flowing through the second inductor V in in the circuit loop including the DC source L 2 the second inductor D O and the second switch S 2 . The current L 2 flowing through the second inductor I L2 makes the voltage L 2 across the second inductor V L2 negative. In addition, the circuit loop composed of the battery V B , the first inductor L 1 , the second switch S 2 and the output capacitor c o charges the first inductor L 1 . The circuit of Mode 14 is as Figure 15 shown.

[0074] Mode 15: d 1 + d 2 The sixth operating mode under the condition of <1. In this mode, the first switch S 1 , the second switch S 2 , and the third switch S 3 are all turned off. The combined current of the current L 1 flowing through the first inductor I L1 and the current L 2 flowing through the second inductor I L2 turns on the second switchS 2 The second capacitor c 2 Charging, the charging process continues until the first switch S 1 The first diode D 1 forward biased and begins to conduct. Mode 15 circuit is as follows Figure 16 shown.

[0075] Mode 16: d 1 + d 2 <1. In this mode, all switches are not conducting. At the start of this mode, the first switch S 1 The first diode D 1 Start conducting current through the first inductor L 1 Current I L1 and flows through the second inductor L 2 Current I L2 The forward composite current is the first switch S 1 Mode 16 circuit is as follows Figure 17 shown.

[0076] Mode 17: d 1 + d 2 The eighth operating mode under the condition of <1. In this mode, the second switch S 2 , the third switch S 3 Turn off, first switch S 1 Zero voltage turn-on. Second inductor L 2 Through the first switch S 1 , DC source V in , the second inductor L 2 , Power diode D O and output capacitor c o The circuit loop is discharged, and at the same time, the first inductor L 1 In the battery VB , First Inductor L 1 and the first switch S 1 The circuit of mode 17 is as follows: Figure 18 shown.

[0077] Mode 18: d 1 + d 2 The ninth operating mode under the condition of <1. In this mode, only the first switch S 1 At the beginning of this operating mode, the third switch S 3 The third diode D 3 Start by including the battery V B , the third diode D 3 , the second inductor L 2 , DC source V in and the first switch S 1 The circuit loop is the second inductor L 2 Conducting negative current I L2 , for the third switch S 3 In the next operation mode, zero voltage switching is prepared. At the same time, the current flowing through the first inductor I L1 Still passing the battery V B , First Inductor L 1 and the first switch S 1 The circuit of mode 18 is as follows Figure 19 shown.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A zero-voltage-switching DC-DC boost converter, characterized in that, Including an input terminal, an output terminal, and a first switch S 1 , a second switch S 2 , a third switch S 3 , a first inductor L 1 , a second inductor L 2 , an output capacitor c o and a power diode D o ; The input terminal includes a storage battery V B and a DC power source V in ; the output terminal is connected to a resistive load R , the resistive load R is in parallel with the output capacitor c o ; the positive electrode of the storage battery V B is connected to the negative electrode of the DC power source L 1 through a first inductor V in ; the positive electrode of the DC power source V in is connected to the anode of the power diode L 2 through a second inductor D 0 ; the negative electrode of the storage battery V B is connected to the source electrode of the first switch S 1 ; the drain electrode of the first switch S 1 is connected to the source electrode of the second switch S 2 and then connected to the negative electrode of the DC power source V in ; the drain electrode of the second switch S 2 is connected to the cathode of the power diode D 0 ; the source electrode of the third switch S 3 is connected to the positive electrode of the storage battery V B ; the drain electrode of the third switch S 3 is connected to the anode of the power diode D 0 ; one end of the output capacitor c o is connected to the cathode of the power diode D 0 ; the other end of the output capacitor c o is connected to the negative electrode of the storage battery V B ; the resistor R is in parallel with the output capacitor c o ; The first switch described S 1 , the second switch S 2 , the third switch S 3 are all provided with a parallel-connected fast recovery diode and a parallel-connected capacitor.

2. The zero-voltage-switching DC-DC boost converter according to claim 1, characterized in that, The first switch described S 1 , the second switch S 2 , and the third switch S 3 are all MOS transistor switches.

3. The zero-voltage-switching DC-DC boost converter according to claim 2, characterized in that, The model of the recovery diode mentioned above is IDW100E60.

4. The zero-voltage-switching DC-DC boost converter according to claim 3, characterized in that, The first switch S 1 , the second switch S 2 , and the third switch S 3 all have a switching frequency higher than their cut-off frequency.

5. The zero-voltage-switching DC-DC boost converter according to claim 1, characterized in that, The battery VB and the DC power source described above V in Two power supply units supply electrical energy to the entire circuit.

6. The zero-voltage-switching DC-DC boost converter according to claim 5, characterized in that, The battery described above V B has a voltage level greater than that of the DC source V in .

7. The zero-voltage-switching DC-DC boost converter according to claim 1, characterized in that, It also includes a DSP chip and a PWM driver; the DSP chip is connected to the PWM driver; the output port of the PWM driver is connected to the switching tube.

8. The zero-voltage-switching DC-DC boost converter according to claim 4, characterized in that, The control method of the converter includes the following steps: The first switch described S 1 , the second switch S 1 2 conduct complementarily. When the first switch S 1 is turned off, the third switch S 3 is turned on.

9. The zero-voltage-switching DC-DC boost converter according to claim 6, characterized in that, The control method of the converter includes the following steps: The first switch described S 1 , the second switch S 2 , and the third switch S 3 are all controlled for on / off by using a PWM pulse drive method for their on / off.

10. The zero-voltage-switching DC-DC boost converter according to claim 8, characterized in that, The control method of the converter includes the following steps: The first switch S 1 , the second switch S 2 , the third switch S 3 are switched in a PWM manner, and the PWM pulse wave has two independent duty cycles; the output voltage of the converter is regulated by the PWM pulse wave with the first duty cycle d 1 , and the desired power of the unidirectional input power storage battery V O is controlled by the PWM pulse wave with the second duty cycle d 2 . V B ​

Images