CN114629349A - Improved high-frequency high step-up ratio SEPIC converter based on switching inductor - Google Patents

Improved high-frequency high step-up ratio SEPIC converter based on switching inductor Download PDF

Info

Publication number
CN114629349A
CN114629349A CN202111025037.6A CN202111025037A CN114629349A CN 114629349 A CN114629349 A CN 114629349A CN 202111025037 A CN202111025037 A CN 202111025037A CN 114629349 A CN114629349 A CN 114629349A
Authority
CN
China
Prior art keywords
diode
inductor
capacitor
mode
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202111025037.6A
Other languages
Chinese (zh)
Other versions
CN114629349B (en
Inventor
吴靖
郑伟彦
蒋燕萍
王志明
蒋涛
苏斌
胡锡幸
边巧燕
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang Dayou Industrial Co ltd Hangzhou Science And Technology Development Branch
Original Assignee
Zhejiang Dayou Industrial Co ltd Hangzhou Science And Technology Development Branch
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang Dayou Industrial Co ltd Hangzhou Science And Technology Development Branch filed Critical Zhejiang Dayou Industrial Co ltd Hangzhou Science And Technology Development Branch
Priority to CN202111025037.6A priority Critical patent/CN114629349B/en
Publication of CN114629349A publication Critical patent/CN114629349A/en
Application granted granted Critical
Publication of CN114629349B publication Critical patent/CN114629349B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses an improved high-frequency high step-up ratio SEPIC converter based on a switch inductor, which comprises a power supply V connected with an input endgAn inductor L2Switch tube Q and capacitor CsDiode D0Capacitance C0And a resistance R; also comprises an inductor L1Inductor L3Diode D1Diode D2And a capacitor C1A first boosting unit; also comprises a diode DMAnd a capacitor CMA second boosting unit; also comprises a capacitor CQCapacitor CQAnd an inductance L1An inductor L2Inductor L3Forming a resonant network; the SEPIC converter is arranged in a diode D1Diode D2Diode DMDiode D0And five working modes are provided under the combination of different on-off states of the switching tube Q; according to the scheme, the two-stage boosting unit is arranged, the boosting capacity and efficiency of the converter are improved, and the resonant network is designed to realize the converterThe soft switching characteristic of the switching tube reduces the switching loss of the switching tube and the voltage stress of the switching tube.

Description

Improved high-frequency high step-up ratio SEPIC converter based on switching inductor
Technical Field
The invention relates to the technical field of power electronics, in particular to an improved high-frequency high step-up ratio SEPIC converter based on a switching inductor.
Background
With the continuous development of social economy science and technology, the demand on energy is increasing day by day, the traditional energy is less and less reserved, and a series of problems such as environmental pollution, greenhouse effect and the like can be caused. The increasing prominence of energy crisis and environmental issues has made the development of new energy sources typified by photovoltaics, fuel cells, and the like urgent. However, the output voltage of these new energy grid-connected power generation systems is usually low, about 30-60V, and cannot reach the higher bus voltage required by the inverter, in order to reduce the number of photovoltaic series connections as much as possible and increase the system reliability, the high step-up ratio dc converter becomes an indispensable part in the new renewable energy grid-connected power generation system, and the conversion efficiency, stability and quick response performance of the dc converter are the keys for the good operation of the whole system.
The traditional Boost converter is simple in structure, but is easily influenced by parasitic parameters in practical application, the duty ratio reaches the limit, the turn-off current of a switching tube Q is large, and a diode has a serious reverse recovery problem; isolated boost converters are limited in application due to transformer size and cost. Therefore, the proposal of a new high step-up ratio converter topology is necessary; along with the increase of the working frequency of the converter, the requirements on power devices are also increased, and the physical characteristics of the traditional Si semiconductor device reach the limit and are not applicable any more; meanwhile, for the application occasions of high frequency and high voltage, the selection of power devices is also limited by the problems of higher voltage stress and hard switching of the switching tube Q, and the work efficiency of the system is not improved.
Chinese patent: the notice number is: CN111010031B, announcement date: the invention relates to an improved high-gain Boost-Sepic converter in 2021, 4 months and 27 days. Comprising a low-voltage DC power supply VinPower switch tube S1A first power diode D1A second power diode D2A third power diode D3A fourth power diode DoA fifth power diode DS1Independent inductor L1Independent inductor L2Independent inductor L3An intermediate capacitor C1An intermediate capacitor C2An output capacitor C3Output capacitor C4Output resistor Ro(ii) a The invention only needs to control one switching tube when in work, reduces the complexity of a control circuit, has the characteristics of continuous input current, easy control of current ripple, common input and output and improvement of time response characteristic of output voltage, has high voltage gain, and reduces the S of the power switching tube1And a power diode D3And DoVoltage stress of (d). The scheme can not realize the soft switching characteristic, and the switching loss of the switching tube is large.
Disclosure of Invention
The invention aims to provide an improved high-frequency high-boost-ratio SEPIC converter based on a switch inductor, the boost capacity and efficiency of the converter are improved by arranging two stages of boost units, a resonant network is designed to realize the soft switching characteristic of a switch tube of the converter, and the switching-on loss of the switch tube and the voltage stress of the switch tube are reduced.
In order to achieve the technical purpose, the invention provides a technical scheme that the improved high-frequency high step-up ratio SEPIC converter based on the switched inductor comprises a power supply V connected with an input endgInductor L2Switch tube Q and capacitor CsDiode D0Capacitor C0And a resistance R;
also comprises an inductor L1Inductor L3Diode D1Diode D2And a capacitor C1Composed first boost sheetElement;
also comprises a diode DMAnd a capacitor CMA second boosting unit;
also comprises a capacitor CQCapacitor CQAnd an inductance L1Inductor L2Inductor L3Forming a resonant network;
power supply VgRespectively connected with the inductor L1First terminal of and diode D1Is electrically connected to the anode terminal of the inductor L1Second terminals of the first and second capacitors are connected to the capacitor C1First terminal of and diode D2Is electrically connected to the anode terminal of the diode D1Respectively connected with the capacitor C1Second terminal and inductor L2Is electrically connected to the first terminal of the inductor L2Second terminals of the first and second diodes are connected to the diode D, respectively1Cathode terminal and capacitor CsFirst terminal of (1), diode DMAnode terminal, capacitor CQIs electrically connected with the drain electrode of the switching tube Q, and a capacitor CsRespectively with the inductor L3First terminal of and diode D0Is electrically connected with the anode terminal of the anode;
diode DMRespectively connected with the inductor L3Second terminal and capacitor CMIs electrically connected to the first terminal of diode D0Respectively connected with the capacitor C0Is electrically connected to a first terminal of a resistor R, a power supply VgThe positive terminal of the switch tube Q is respectively connected with the source electrode of the switch tube Q and the capacitor CQSecond terminal of (1), capacitor C0And a second end of the resistor R is electrically connected;
the SEPIC converter is arranged in a diode D1Diode D2Diode DMDiode D0And under the combination of different on-off states of the switching tube Q, five working modes are provided, wherein the mode is one: characterizing the energy transfer phase of the SEPIC converter to the load; a second mode: characterizing a parallel capacitance resonance stage; mode three: diode freewheeling stage; and a fourth mode: a switching tube Q is switched on; a fifth mode: and (5) charging the parallel capacitor.
In the scheme, the third generation is selected because the switching loss of the power device under the high-frequency environment is increased along with the increase of the switching lossThe novel wide bandgap semiconductor device gallium nitride (GaN) is used as a switching tube, has the advantages of small parasitic parameters, high voltage resistance level, small volume size and the like, is more suitable for high-voltage and high-frequency application occasions, and can realize ZVS (soft switching characteristic) of the switching tube, reduce switching loss, reduce voltage stress of the switching tube and improve efficiency by combining a soft switching technology. The high-frequency converter has the advantages that the volume of passive elements such as inductors and capacitors is reduced, and the system miniaturization is further realized by using a planar magnetic structure and removing an electrolytic capacitor; meanwhile, a plurality of magnetic elements in the converter are integrated on a pair of magnetic cores by combining a magnetic integration technology, so that the size of the converter can be further reduced, and the power density is improved; according to the scheme, a two-stage boosting unit and a resonant network are designed on the basis of a traditional SEPIC converter, a novel topological structure is obtained, and high boosting capacity and soft switching characteristics of a switching tube Q can be realized at the same time; the first boosting unit is a switch inductor structure with a pump-up capacitor and composed of an inductor L1Inductor L3Diode D1Diode D2And a capacitor C1The second boost unit is composed of a diode DM and a capacitor CMA boosting unit; capacitor CQIs the sum of the internal parasitic capacitance and the external parallel capacitance of the switching tube Q. In addition, the inductance L2Operating in an interrupted state with a capacitor CQAnd resonance occurs, and the voltage stress of the switching tube Q is reduced to zero before a driving signal arrives through proper parameter design, so that zero voltage switching-on is realized. The Q voltage stress of the switching tube is a capacitor CMThe voltage at two ends is reduced compared with the traditional SEPIC converter. At the same time, the inductance L1，L3The size of the inductor L also influences the working mode of the converter, and in order to make the working modes of the two inductors consistent and facilitate analysis, the inductor L is used for1And L3The two are set to the same inductance value, and the current direction is not changed in the whole switching period, so that the two are required to work in a continuous state. Capacitor Cs，CMAnd C1Sufficiently large that the voltage across it can be considered constant; the capacitor Co is an output voltage stabilization capacitor.
Preferably, the circuit control logic of the mode one is as follows:
at t0At any moment, the parallel capacitor C at two ends of the switch tube QQThe voltage at both ends is equal to the capacitance CMVoltage, capacitance CQFinishing charging; diode DMAnd DoOn, D1，D2Cutting off; inductor L1And an inductance L3Through diode DMCapacitor CMCharging while passing energy through diode DoTo a capacitor CoAnd a load R;
inductor L2Operating in an intermittent state with stored energy via diode DoIs released to the load R when flowing through the diode DMAnd a diode DoLinearly decreases to zero, recording end time t1And the mode ends.
Preferably, the circuit control logic of the mode two is as follows:
at t1Time of day, diode DMAnd DoTurn off, shunt capacitance CQAnd an inductance L1An inductor L2Inductor L3Resonance, each inductor and capacitor C in the resonance processQThe voltage and the current at two ends change in a nonlinear way;
when the capacitor C is connected in parallelQAnd (4) when the voltage resonance at the two ends reaches zero, namely the voltage stress at the two ends of the switching tube Q is 0, the second mode is ended, so that the ZVS of the switching tube Q is realized, and the ending time t is recorded2。
Preferably, the circuit control logic of mode three is as follows:
at t2At the moment, according to the characteristic that the inductive current cannot change suddenly, the diode D1And a diode D2Opening; at this time, the inductance L1And L3The voltage stress at both ends is equal to the input supply voltage VgThe inductor current increases linearly to saturation.
Preferably, the circuit control logic of mode four is as follows:
at t3At the moment, the switch tube Q is switched on at zero voltage, and the diode DMAnd a diode DoKeep off state, inductance L2The current is first linearly decreased to 0 and then increased in the reverse direction, and the energy is increased by the capacitor CMProvided is a method.
Preferably, the circuit control logic of mode five is as follows:
t4at the moment, the switch tube Q is turned off and the diode D1And a diode D2Cut-off, shunt capacitance CQCharged by the input voltage, the voltage across it increases, while the inductance L1Inductor L2Inductor L3Voltage of (2) decreases nonlinearly, polarity changes to reverse, when CQThe voltage across the terminals increases to and CMWhen the voltages at the two ends are consistent, the fifth mode is ended, and the ending time t is recorded5。
Preferably, the circuit control logic in the five operation modes is realized by parameter setting of electric elements in the SEPIC converter, and the method comprises the following steps:
calculating a boost ratio M of the SEPIC converter according to a volt-second balance principle;
according to mode I medium inductance L1And L2The duration t of the capacitor charging phase in the current variation calculation mode fiver；
According to the step-up ratio M and the duration trCalculating the parallel capacitance CQ。
Preferably, the boost ratio M is calculated as follows:
Figure BDA0003243022630000041
wherein T is a switching period, and the time T for the mode four-switch tube to be switched onon＝t4-t3Time T of modal five gate voltage riser＝t5-t4＝DrT, time T of energy transfer from mode 1 to the load sided＝t1-t0＝DdResonant discharge stage T of Q parallel capacitor of T, mode 2 switching tubeδ＝t2-t1＝DδT, time T of freewheeling of mode 3 diodeb＝t3-t2＝DbT; wherein the coefficient D, Dr、Dd、Dδ、DbTime of each mode respectivelyRatio of occupation.
Preferably, the boost ratio M is calculated as follows: due to mode five-capacitor CQThe charging time is very short, the inductor voltage is regarded as a linear drop in this phase, and the charging current is considered as a constant value;
ICQ＝ΔiL1+ΔiL2
Figure BDA0003243022630000042
Figure BDA0003243022630000043
wherein, Δ iL1、ΔiL2Are respectively an inductance L1And L2An amount of current change in mode one; thus, the duration t of the modal five-capacitor charging phase can be obtainedrThe formula is expressed as follows:
Figure BDA0003243022630000044
wherein L iseqIs the equivalent inductance of the SEPIC converter.
Preferably, the inductance L1Both ends are pressed at (t)on+td+tr) Meet the volt-second balance equation in the phase and connect the capacitor C in parallelQThe formula is expressed as follows:
Figure BDA0003243022630000045
preferably, to realize reliable soft switching of the switch tube, the switch tube should be ensured to be turned on before the drain-source voltage resonates to 0 again when t isb＞tbmaxWhen, vdsSecondary resonance will occur and ZVS cannot be achieved, thus requiring duration t of mode threebThe following formula is satisfied:
0≤tb≤tbmax；
while satisfying the following formula during one switching period:
tb+td＜T-ton；
wherein, tbmax＝Tr-2tδ；
The duration D of three modal stages can be obtained by the formula of the boost ratio MbThe expression of (a) is as follows:
Figure BDA0003243022630000051
the following can be obtained: duration D of a mode phasedShould satisfy the following formula:
Figure BDA0003243022630000052
the invention has the beneficial effects that: according to the improved high-frequency high step-up ratio SEPIC converter based on the switch inductor, the step-up capacity and efficiency of the converter are improved by arranging the two-stage step-up units, the soft switching characteristic of a switch tube of the converter is realized by designing the resonant network, and the switching-on loss of the switch tube and the voltage stress of the switch tube are reduced.
Drawings
Fig. 1 is a circuit structure diagram of the improved high-frequency high step-up ratio SEPIC converter based on the switched inductor.
Fig. 2 is a circuit control diagram of mode one according to the present invention.
Fig. 3 is a circuit control diagram of mode two according to the present invention.
Fig. 4 is a circuit control diagram of mode three of the present invention.
Fig. 5 is a circuit control diagram of mode four of the present invention.
Fig. 6 is a circuit control diagram of mode five of the present invention.
FIG. 7 is a waveform diagram of circuit parameters under various modes of the present invention.
FIG. 8 shows a capacitor C according to the present inventionQVoltage gain M and time tdA three-dimensional relationship diagram of (2).
FIG. 9 is a graph of the voltage waveforms across the drain and source of the Q-switch of the present invention.
FIG. 10 shows the output voltage V of the present inventionoInput voltage VgAnd an output current IoAnd (4) waveform diagrams.
FIG. 11 shows the output voltage V of the present inventionoDrive signal vgsAnd the voltage v at the two ends of the drain and the source of the switch tubedsAnd (4) waveform diagrams.
Detailed Description
For the purpose of better understanding the objects, technical solutions and advantages of the present invention, the following detailed description of the present invention with reference to the accompanying drawings and examples should be understood that the specific embodiment described herein is only a preferred embodiment of the present invention, and is only used for explaining the present invention, and not for limiting the scope of the present invention, and all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the scope of the present invention.
Example (b): as shown in figure 1, the circuit structure diagram of the improved high-frequency high step-up ratio SEPIC converter based on the switch inductance comprises a power supply V connected with an input endgInductor L2Switch tube Q and capacitor CsDiode D0Capacitance C0And a resistance R; also comprises an inductor L1Inductor L3Diode D1Diode D2And a capacitor C1A first boosting unit; also comprises a diode DMAnd a capacitor CMA second boosting unit; also comprises a capacitor CQCapacitor CQAnd an inductance L1An inductor L2Inductor L3Forming a resonant network; power supply VgRespectively connected with the inductor L1First terminal of and diode D1Is electrically connected to the anode terminal of the inductor L1Second terminals of the first and second capacitors are connected to the capacitor C1First terminal of and diode D2Is electrically connected to the anode terminal of the diode D1Respectively connected with the capacitor C1Second terminal and inductor L2Is electrically connected to the first terminal of the inductor L2Second terminals of the first and second diodes are connected to the diode D, respectively1Cathode terminal and capacitor CsFirst terminal of (1), diode DMAnode terminal, capacitor CQIs electrically connected with the drain electrode of the switching tube Q, and a capacitor CsSecond terminals of the first and second inductors are connected to the inductor L3First terminal of and diode D0The anode terminal of the anode is electrically connected; diode DMRespectively connected with the inductor L3Second terminal and capacitor CMIs electrically connected to the first terminal of diode D0Respectively connected with the capacitor C0Is electrically connected to a first terminal of a resistor R, a power supply VgThe positive terminal of the switch tube Q is respectively connected with the source electrode of the switch tube Q and the capacitor CQSecond terminal of (1), capacitor C0And a second end of the resistor R is electrically connected; the SEPIC converter is arranged in a diode D1Diode D2Diode DMDiode D0And under the combination of different on-off states of the switching tube Q, five working modes are provided, wherein the mode I is as follows: characterizing the energy transfer phase of the SEPIC converter to the load; a second mode: characterizing a parallel capacitance resonance stage; mode three: diode freewheeling stage; and a fourth mode: a switching tube Q is switched on; a fifth mode: and (5) charging the parallel capacitor.
In this embodiment, because the switching loss of the power device increases in the high-frequency environment, the third generation of the wide bandgap semiconductor device gallium nitride (GaN) is selected as the switching tube, which has the advantages of small parasitic parameter, high voltage-withstanding level, small size and the like, and is more suitable for the high-voltage and high-frequency application occasions. The high-frequency converter has the advantages that the volume of passive elements such as inductors and capacitors is reduced, and the miniaturization of the system is further realized by using a planar magnetic structure and removing an electrolytic capacitor; meanwhile, a plurality of magnetic elements in the converter are integrated on a pair of magnetic cores by combining a magnetic integration technology, so that the size of the converter can be further reduced, and the power density is improved; according to the scheme, a two-stage boosting unit and a resonant network are designed on the basis of a traditional SEPIC converter, a novel topological structure is obtained, and high boosting capacity and soft switching characteristics of a switching tube Q can be realized at the same time; first booster unitThe switch inductor structure with pump-up capacitor is composed of inductor L1Inductor L3Diode D1Diode D2And a capacitor C1The second boost unit is composed of a diode DM and a capacitor CMA boosting unit; capacitor CQIs the sum of the internal parasitic capacitance and the external parallel capacitance of the switching tube Q. In addition, the inductance L2Operating in an interrupted state with a capacitor CQAnd resonance occurs, and the voltage stress of the switching tube Q is reduced to zero before a driving signal arrives through proper parameter design, so that zero voltage switching-on is realized. The Q voltage stress of the switching tube is capacitance CMThe voltage at two ends is reduced compared with the traditional SEPIC converter. At the same time, the inductance L1，L3The magnitude of the inductance L also influences the working mode of the converter, and in order to make the working modes of the two inductors consistent and convenient to analyze, the inductance L is used1And L3The two are set to the same inductance value, and the current direction is not changed in the whole switching period, so that the two are required to work in a continuous state. Capacitor Cs，CMAnd C1Sufficiently large that the voltage across it can be considered constant; the capacitor Co is an output voltage stabilization capacitor, and is a waveform diagram in each mode as shown in fig. 7.
As shown in fig. 2, the circuit control logic of mode one is as follows:
at t0At any moment, the parallel capacitor C at two ends of the switch tube QQThe voltage at both ends is equal to the capacitance CMVoltage, capacitance CQFinishing charging; diode DMAnd DoOn, D1，D2Cutting off; inductor L1And an inductance L3Through diode DMCapacitor CMCharging while passing energy through diode DoTo a capacitor CoAnd a load R;
inductor L2Operating in discontinuous state with stored energy passing through diode DoIs released to the load R when flowing through the diode DMAnd a diode DoLinearly decreases to zero, recording end time t1And the mode ends.
As shown in fig. 3, the circuit control logic of mode two is as follows:
at t1Time of day, diode DMAnd DoTurn-off, shunt capacitance CQAnd an inductance L1Inductor L2An inductor L3Resonance, each inductor and capacitor C in the resonance processQThe voltage and the current at two ends change in a nonlinear way;
when the capacitor C is connected in parallelQWhen the voltage resonance at two ends reaches zero, namely the voltage stress at two ends of the switching tube Q is 0, the second mode is ended, so that the ZVS of the switching tube Q is realized, and the ending time t is recorded2。
As shown in fig. 4, the circuit control logic of mode three is as follows:
at t2At the moment, according to the characteristic that the inductive current cannot change suddenly, the diode D1And a diode D2Opening; at this time, the inductance L1And L3The voltage stress at both ends is equal to the input supply voltage VgThe inductor current increases linearly to saturation.
As shown in fig. 5, the circuit control logic of mode four is as follows:
at t3At the moment, the switch tube Q is switched on at zero voltage, and the diode DMAnd a diode DoKeep off state, inductance L2The current is first linearly decreased to 0 and then increased in the reverse direction, and the energy is increased by the capacitor CMProvided is a method.
As shown in fig. 6, the circuit control logic of mode five is as follows:
t4at the moment, the switch tube Q is turned off and the diode D1And a diode D2Cut-off, shunt capacitance CQCharged by the input voltage, the voltage across it increases, while the inductance L1Inductor L2Inductor L3Voltage of (2) decreases nonlinearly, polarity changes to reverse, when CQThe voltage across the terminals increases to and CMWhen the voltages at the two ends are consistent, the fifth mode is ended, and the ending time t is recorded5。
The circuit control logic under the five working modes is realized through parameter setting of electric elements in the SEPIC converter, and the method comprises the following steps:
SEPIC converter for calculation according to volt-second balance principleThe step-up ratio M of (1); the inductance voltage of two stages of a mode two and a mode five is approximately linearized and replaced by average voltage, and the inductance L can be processed according to the volt-second balance principle1The two-end voltage is in a column volt-second balance equation in one switching period, so that the boost ratio of the converter is obtained, and the calculation formula of the boost ratio M is as follows:
Figure BDA0003243022630000071
wherein T is the switching period, and the time T for switching on the modal four-switch tubeon＝t4-t3Time T of modal five gate voltage riser＝t5-t4＝DrT, time T of energy transfer from mode 1 to the load sided＝t1-t0＝DdResonant discharge stage T of Q parallel capacitor of T, mode 2 switching tubeδ＝t2-t1＝DδTime T of freewheeling in a mode 3 diodeb＝t3-t2＝DbT; wherein the coefficient D, Dr、Dd、Dδ、DbRespectively, the time ratio of each mode.
According to a mode-neutral inductance L1And L2The duration t of the capacitor charging phase in the current variation calculation mode fiver(ii) a Due to mode five-capacitor CQThe charging time is very short, the inductor voltage is regarded as a linear drop in this phase, and the charging current is considered as a constant value;
ICQ＝ΔiL1+ΔiL2
Figure BDA0003243022630000081
Figure BDA0003243022630000082
wherein, Δ iL1、ΔiL2Are respectively an inductance L1And L2The amount of current change in mode one; thus, the duration t of the modal five-capacitor charging phase can be obtainedrThe formula is expressed as follows:
Figure BDA0003243022630000083
wherein L iseqIs the equivalent inductance of the SEPIC converter.
According to FIG. 7, the inductance L is approximately considered1Inductor L2The current is equal in magnitude at the end of the first mode and the third mode according to the step-up ratio M and the duration trCalculating the parallel capacitance CQ(ii) a Inductor L1Both ends are pressed at (t)on+td+tr) Satisfy volt-second balance equation, capacitance C in phaseQWith voltage gain M and modal duration tdAs shown in FIG. 8, the capacitance C is connected in parallelQThe formula is expressed as follows:
Figure BDA0003243022630000084
to realize reliable soft switching of the switch tube, it should be ensured that the switch tube is turned on before the drain-source voltage resonates to 0 again, as shown in fig. 9, when tb＞tbmaxWhen, vdsSecondary resonance will occur and ZVS cannot be achieved, thus requiring duration t of mode threebThe following formula is satisfied:
0≤tb≤tbmax；
while satisfying the following formula during one switching period:
tb+td＜T-ton；
wherein, tbmax＝Tr-2tδ；
The duration D of three stages of modes can be obtained by a boost ratio M formulabThe expression of (a) is as follows:
Figure BDA0003243022630000091
the following can be obtained: duration D of a mode phasedShould satisfy the following formula:
Figure BDA0003243022630000092
one embodiment is suitable for the improved high-frequency high step-up ratio SEPIC converter designed by the scheme: according to a laboratory prototype with the rated power of 200W, the SEPIC converter designed by the scheme is subjected to simulation analysis, and the measured input voltage VgOutput voltage VoOutput current IoThe waveform of (2) is shown in fig. 10. The improved SEPIC converter can realize 400V direct current output, 13.3 times of boosting capacity and 500mA output current under the condition of 30V input; the designed SEPIC converter adds a parallel capacitor CQA resonance stage exists, so that ZVS of the switching tube is realized, and the switching loss is reduced; meanwhile, the voltage stress at the two ends of the switch tube is reduced. Measured drive signal vgsVoltage v across the drain and source of the switch tubedsAnd an output voltage VoThe waveform is shown in fig. 11.
The above-mentioned embodiments are preferred embodiments of the improved high-frequency high step-up ratio SEPIC converter based on switched inductor, and the scope of the present invention is not limited thereto, and the scope of the present invention includes and is not limited to the embodiments, and all equivalent changes in shape and structure according to the present invention are within the protection scope of the present invention.

Claims (10)

1. Improved generation high frequency high step-up ratio SEPIC converter based on switched inductor, its characterized in that: comprising a power supply V connected to an inputgInductor L2Switch tube Q and capacitor CsDiode D0Capacitor C0And a resistance R;
also comprises an inductor L1Inductor L3Diode D1Diode D2And a capacitor C1A first boosting unit;
also comprises a diode DMAnd a capacitor CMA second boosting unit;
also comprises a capacitor CQCapacitor CQAnd an inductance L1Inductor L2Inductor L3Forming a resonant network;
power supply VgRespectively connected with the inductor L1First terminal of and diode D1Is electrically connected to the anode terminal of the inductor L1Second terminals of the first and second capacitors are connected to the capacitor C1First terminal of and diode D2Is electrically connected to the anode terminal of the diode D1Respectively connected with the capacitor C1Second terminal and inductor L2Is electrically connected to the first terminal of the inductor L2Second terminals of the first and second diodes are connected to the diode D, respectively1Cathode terminal and capacitor CsFirst terminal of (1), diode DMAnode terminal, capacitor CQIs electrically connected with the drain electrode of the switching tube Q, and a capacitor CsSecond terminals of the first and second inductors are connected to the inductor L3First terminal of and diode D0The anode terminal of the anode is electrically connected;
diode DMRespectively connected with the inductor L3Second terminal and capacitor CMIs electrically connected to the first terminal of diode D0Respectively connected with the capacitor C0Is electrically connected to a first terminal of a resistor R, a power supply VgThe positive terminal of the switch tube Q is respectively connected with the source electrode of the switch tube Q and the capacitor CQSecond terminal of (1), capacitor C0And a second end of the resistor R is electrically connected;
the SEPIC converter is arranged in a diode D1Diode D2Diode DMDiode D0And under the combination of different on-off states of the switching tube Q, five working modes are provided, wherein the mode is one: characterizing the energy transfer phase of the SEPIC converter to the load; mode two: characterizing a parallel capacitance resonance stage; mode three: diode freewheeling stage; and a fourth mode: a switching-on stage of a switching tube Q; a fifth mode: and (5) charging the parallel capacitor.
2. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 1, wherein: the circuit control logic of the mode one is as follows:
at t0At any moment, the parallel capacitor C at two ends of the switch tube QQThe voltage at both ends is equal to the capacitance CMVoltage, capacitance CQFinishing charging;
diode DMAnd DoOn, D1，D2Cutting off; inductor L1And an inductance L3Through diode DMCapacitor CMCharging while passing energy through diode DoTo a capacitor CoAnd a load R;
inductor L2Operating in an intermittent state with stored energy via diode DoIs released to the load R when flowing through the diode DMAnd a diode DoIs linearly reduced to zero and the recording ends at time t1And the mode ends.
3. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 1, wherein: the circuit control logic of the mode two is as follows:
at t1Time of day, diode DMAnd DoTurn off, shunt capacitance CQAnd an inductance L1Inductor L2Inductor L3Resonance, each inductor and capacitor C in the resonance processQThe voltage and the current at two ends change in a nonlinear way;
when the capacitor C is connected in parallelQWhen the voltage resonance at two ends reaches zero, namely the voltage stress at two ends of the switching tube Q is 0, the second mode is ended, so that the ZVS of the switching tube Q is realized, and the ending time t is recorded2。
4. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 1, wherein: the circuit control logic of the mode three is as follows:
at t2At the moment, according to the characteristic that the inductive current cannot change suddenly, the diode D1And a diode D2Opening; at this time, the inductance L1And L3The voltage stress at both ends is equal to the input supply voltage VgThe inductor current increases linearly to saturation.
5. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 1, wherein: the circuit control logic of the mode four is as follows:
at t3At the moment, the switch tube Q is switched on at zero voltage, and the diode DMAnd a diode DoKeep off state, inductance L2The current is first linearly decreased to 0 and then increased in the reverse direction, and the energy is increased by the capacitor CMProvided is a method.
6. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 1, wherein: the circuit control logic of the mode five is as follows:
t4at the moment, the switch tube Q is turned off and the diode D1And a diode D2Cut-off, shunt capacitance CQCharged by the input voltage, the voltage across it increases and the inductance L1Inductor L2Inductor L3Voltage of (2) decreases nonlinearly, polarity changes to reverse, when CQThe voltage at both ends increases to and CMWhen the voltages at the two ends are consistent, the fifth mode is ended, and the ending time t is recorded5。
7. The improved high frequency high step-up ratio SEPIC converter based on switched inductors according to claim 1 or 2 or 3 or 4 or 5 or 6, wherein:
the circuit control logic under the five working modes is realized through parameter setting of electric elements in the SEPIC converter, and the method comprises the following steps:
calculating the boost ratio M of the SEPIC converter according to a volt-second balance principle;
according to mode I medium inductance L1And L2The current variation quantity calculation mode five, the duration t of the capacitor charging phaser；
According to the step-up ratio M and the duration trCalculating the parallel capacitance CQ。
8. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 7, wherein: the boost ratio M is calculated as follows:
Figure FDA0003243022620000021
wherein T is a switching period, and the time T for switching on the switching tube Q in the mode IVon＝t4-t3Time T of rise of gate voltage in mode fiver＝t5-t4＝DrT, time T of energy transfer to load side in mode oned＝t1-t0＝DdT, Q parallel capacitor resonant discharge stage T of mode two switching tubeδ＝t2-t1＝DδT, time T of diode freewheeling in mode IIIb＝t3-t2＝DbT; wherein the coefficient D, Dr、Dd、Dδ、DbRespectively, the time ratio of each mode.
9. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 8, wherein: the boost ratio M is calculated as follows: due to mode five-capacitor CQThe charging time is very short, the inductor voltage is regarded as a linear drop in this phase, and the charging current is considered as a constant value;
ICQ＝ΔiL1+ΔiL2
Figure FDA0003243022620000031
Figure FDA0003243022620000032
wherein, Δ iL1、ΔiL2Are respectively an inductance L1And L2The amount of current change in mode one; thus, the duration t of the modal five-capacitor charging phase can be obtainedrThe formula is expressed as follows:
Figure FDA0003243022620000033
wherein L iseqIs the equivalent inductance of the SEPIC converter.
10. The improved high frequency high step-up ratio SEPIC converter based on switched inductor as claimed in claim 9, wherein: inductor L1Both ends are pressed at (t)on+td+tr) Meet the volt-second balance equation in the phase and connect the capacitor C in parallelQThe formula is expressed as follows:
Figure FDA0003243022620000034
CN202111025037.6A 2021-09-02 2021-09-02 Improved high-frequency high-step-up ratio SEPIC converter based on switching inductance Active CN114629349B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111025037.6A CN114629349B (en) 2021-09-02 2021-09-02 Improved high-frequency high-step-up ratio SEPIC converter based on switching inductance

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111025037.6A CN114629349B (en) 2021-09-02 2021-09-02 Improved high-frequency high-step-up ratio SEPIC converter based on switching inductance

Publications (2)

Publication Number Publication Date
CN114629349A true CN114629349A (en) 2022-06-14
CN114629349B CN114629349B (en) 2023-08-18

Family

ID=81897291

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111025037.6A Active CN114629349B (en) 2021-09-02 2021-09-02 Improved high-frequency high-step-up ratio SEPIC converter based on switching inductance

Country Status (1)

Country Link
CN (1) CN114629349B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116599343A (en) * 2023-07-19 2023-08-15 深圳市恒运昌真空技术有限公司 High-gain Sepic converter and control method thereof
CN116667666A (en) * 2023-07-28 2023-08-29 深圳市恒运昌真空技术有限公司 High-gain Boost converter and control method thereof
CN116780898A (en) * 2023-08-14 2023-09-19 深圳市恒运昌真空技术有限公司 High-gain Cuk converter and control method thereof
CN116805840B (en) * 2023-08-24 2023-11-10 深圳市恒运昌真空技术有限公司 Soft switching high-gain converter and control method thereof

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010200519A (en) * 2009-02-26 2010-09-09 Shindengen Electric Mfg Co Ltd Boosting chopper circuit
CN105186866A (en) * 2015-09-23 2015-12-23 三峡大学 Non-isolated soft switch high-gain DC/DC converter
CN105515377A (en) * 2016-01-26 2016-04-20 上海电力学院 Soft switch high gain direct current converter based on coupling inductances and voltage doubling capacitors
TWI569566B (en) * 2015-12-24 2017-02-01 遠東科技大學 High voltage gain power converter
CN106602872A (en) * 2016-12-14 2017-04-26 华南理工大学 Cascaded voltage lifting quasi-Z source converter
CN109951072A (en) * 2019-03-26 2019-06-28 哈尔滨工业大学 Novel Soft Switching high step-up ratio converter and its working method based on Sepic circuit
CN110011543A (en) * 2019-04-26 2019-07-12 哈尔滨工业大学 Based on the high step-up ratio DC/DC converter for improving SEPIC circuit
CN112736999A (en) * 2020-11-30 2021-04-30 浙江大有实业有限公司杭州科技发展分公司 Series battery equalization device with multiple flyback converters

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010200519A (en) * 2009-02-26 2010-09-09 Shindengen Electric Mfg Co Ltd Boosting chopper circuit
CN105186866A (en) * 2015-09-23 2015-12-23 三峡大学 Non-isolated soft switch high-gain DC/DC converter
TWI569566B (en) * 2015-12-24 2017-02-01 遠東科技大學 High voltage gain power converter
CN105515377A (en) * 2016-01-26 2016-04-20 上海电力学院 Soft switch high gain direct current converter based on coupling inductances and voltage doubling capacitors
CN106602872A (en) * 2016-12-14 2017-04-26 华南理工大学 Cascaded voltage lifting quasi-Z source converter
CN109951072A (en) * 2019-03-26 2019-06-28 哈尔滨工业大学 Novel Soft Switching high step-up ratio converter and its working method based on Sepic circuit
CN110011543A (en) * 2019-04-26 2019-07-12 哈尔滨工业大学 Based on the high step-up ratio DC/DC converter for improving SEPIC circuit
CN112736999A (en) * 2020-11-30 2021-04-30 浙江大有实业有限公司杭州科技发展分公司 Series battery equalization device with multiple flyback converters

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116599343A (en) * 2023-07-19 2023-08-15 深圳市恒运昌真空技术有限公司 High-gain Sepic converter and control method thereof
CN116599343B (en) * 2023-07-19 2024-03-15 深圳市恒运昌真空技术股份有限公司 High-gain Sepic converter and control method thereof
CN116667666A (en) * 2023-07-28 2023-08-29 深圳市恒运昌真空技术有限公司 High-gain Boost converter and control method thereof
CN116667666B (en) * 2023-07-28 2024-04-26 深圳市恒运昌真空技术股份有限公司 High-gain Boost converter and control method thereof
CN116780898A (en) * 2023-08-14 2023-09-19 深圳市恒运昌真空技术有限公司 High-gain Cuk converter and control method thereof
CN116780898B (en) * 2023-08-14 2023-11-21 深圳市恒运昌真空技术有限公司 High-gain Cuk converter and control method thereof
CN116805840B (en) * 2023-08-24 2023-11-10 深圳市恒运昌真空技术有限公司 Soft switching high-gain converter and control method thereof

Also Published As

Publication number Publication date
CN114629349B (en) 2023-08-18

Similar Documents

Publication Publication Date Title
CN114629349B (en) Improved high-frequency high-step-up ratio SEPIC converter based on switching inductance
CN107517003B (en) Output-floating-input parallel high-gain Boost conversion circuit and switching method
CN112583252B (en) High-power-density high-gain converter and control method thereof
CN107896059B (en) Capacitor clamp type high-gain boost converter based on staggered parallel connection
CN113394975B (en) High-voltage gain DC-DC direct current converter
CN106487226B (en) Tri- level Buck converter of IPOP, cascade system and its control method
CN107919797A (en) The fuel cell efficient voltage boosting dc converter of wide input range crisscross parallel type
CN103066841A (en) Voltage-multiplying DC converter based on charge pump capacitor
CN113541486B (en) Interleaved diode capacitor network high-gain ZVT (zero voltage zero volt) direct current converter and auxiliary circuit
CN114583953A (en) Zero-ripple energy storage bidirectional converter and control method thereof
CN109672332A (en) A kind of zero ripple DC-DC converter of single tube high-gain
CN110943617B (en) Circuit topological structure of double-switch type DC/DC converter
CN205356155U (en) Single tube buck -Boost -flyback voltage step -up and step -down typed circuit
Li et al. A Full Soft-Switching High Step-Up DC/DC Converter With Active Switched Inductor and Three-Winding Coupled Inductor
CN217087767U (en) Ultrahigh-gain DC/DC boost converter
CN110611425A (en) Current sharing method based on series-parallel Boost converter
CN113630009B (en) High-performance non-isolated bidirectional direct current converter and control method thereof
CN111786558B (en) High-efficiency converter with high boosting capacity
CN113364294B (en) Low-voltage stress and low-input current ripple high-gain converter and control method
TWI752579B (en) Interleaved high voltage conversion ratio dc/dc converter
CN105827110A (en) Three-winding coupled inductor voltage-doubling type single switch tube boost direct-current converter
TWI762396B (en) High voltage conversion ratio dc converter
CN110011543A (en) Based on the high step-up ratio DC/DC converter for improving SEPIC circuit
TW202112044A (en) High voltage gain dc/dc converter
CN113346743B (en) Non-isolated high-gain direct current converter

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant