AU2020220124B1 - Secondary parallel lcd forward converter capable of avoiding reverse charging of energy storage capacitor - Google Patents
Secondary parallel lcd forward converter capable of avoiding reverse charging of energy storage capacitor Download PDFInfo
- Publication number
- AU2020220124B1 AU2020220124B1 AU2020220124A AU2020220124A AU2020220124B1 AU 2020220124 B1 AU2020220124 B1 AU 2020220124B1 AU 2020220124 A AU2020220124 A AU 2020220124A AU 2020220124 A AU2020220124 A AU 2020220124A AU 2020220124 B1 AU2020220124 B1 AU 2020220124B1
- Authority
- AU
- Australia
- Prior art keywords
- diode
- capacitor
- forward converter
- inductance
- energy storage
- 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.)
- Active
Links
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
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0038—Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0051—Diode reverse recovery losses
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
- H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
-
- 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 present disclosure provides a secondary parallel LCD forward converter capable of
avoiding reverse charging of energy storage capacitor, comprising a forward converter
main circuit and an energy transfer and transmission circuit. The forward converter main
circuit includes a high-frequency transformer T, a switching tube S, a diode D1, a diode
D2, an inductance LI, and a capacitor C1. The energy transfer and transmission circuit
includes a diode D3, a capacitor C2, a diode D4, and an inductance L2. The circuit
structure of the present disclosure has simple circuit structure and high reliability. The
diode D4 ensures that the circuit will not be charged reverse by C2,which reduces the
reactive power loss of the converter, eliminates the reverse recovery problem of the diode
D4 and reduces the loss of switching tube. And the excitation energy could be transferred
to the load side, which improves the energy transmission efficiency, suitable for high
power transmission.
Description
[0001] This patent disclosure relates to afield of switching power supplies, in
particular to a secondary parallel LCD forward converter capable of avoiding reverse
charging of energy storage capacitor.
[0002] In the numerous isolated switching power supply conversion topologies,
compared with the flyback converter, the power of the forward converter is not limited
by the ability of the transformer to store energy; compared with half-bridge and
full-bridge converters, the forward converter uses fewer components, has simpler
circuits, lower costs, and higher reliability. Therefore, due to its relatively simple
structure, low cost, input and output isolation, and high operational reliability, the
forward converter circuit is more suitable for application in small and medium-power
power conversion occasions, and is highly concerned by the industry.
[0003] However, for the single-tube forward converter, because it works in the state of
forward excitation, its high-frequency transformer core is unidirectionally magnetized,
and itself has no magnetic reset function, which makes it very likely to cause problems
such as magnetic core saturation. The result of magnetic saturation will cause the current
flowing through the switching tube to increase sharply, or even damage the switching
tube, which to a large extent limits the promotion of the forward converter, so, a special
magnetic reset circuit or energy transfer circuit must be added to avoid magnetic core
saturation.
[0004] The main working mechanism of the magnetic reset circuit is to transfer the
excitation energy during the switch off time of each cycle, which could be consumed on
other devices or returned to the input power supply or transmitted to the load end. There
are many types of magnetic reset circuits used in existing forward converters, which are
roughly divided into three types. One is to insert a reset winding at the input end to
return energy to the input power; the second is to connect reset circuits such as RCD and
LCD on the primary side of the transformer to consume energy or return to the input end;
the third is to take reset measures on the secondary side to transfer energy to the output
end.
[0005] But, the traditional RCD clamping circuit is relatively simple, and its
shortcoming is that the excitation energy is consumed in the clamping resistor, which
makes it difficult to improve the overall efficiency of the system; active clamping
technology is a good method to achieve magnetic reset, but it increases the complexity,
design difficulty and cost of the converter circuit; the reset method of the magnetic reset
winding is mature and reliable, and the excitation energy could be returned to the input
power supply, but the magnetic reset winding increases the complexity of the
transformer structure and the voltage stress of the power switching tube.
[0006] The existing reset measures on the secondary side either need to increase the
reset winding or circuit complexity, which increases the difficulty and cost of the design
and manufacturing of the transformer or circuit; or need to use more diodes to realize
energy transfer, which increases circuit losses; or it will affect the working mode of
forward inductance or other electrical performance indicators, which is not conducive to
high power transmission.
[0007] Therefore, in order to further promoting the application of forward converters, solving the problem of magnetic reset, improving its comprehensive performance, and addressing the shortcomings of other reset methods, researching on new magnetic reset methods is a subject that needs to be continuously discussed.
[0008] An object of the present disclosure is to provide a secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor. Then problems of the existing magnetic reset circuit can be solved, such as low excitation energy utilization rate, complex circuit composition, large loss, low efficiency.
[0009] The present disclosure provides a secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor to solve technical problems of the present disclosure, comprising a forward converter main circuit (1); and an energy transfer and transmission circuit (2) connected to the forward converter main circuit (1); the forward converter main circuit (1) includes a high-frequency transformer T, a switching tube S, a diode D1, a diode D2, an inductance LI; and a capacitor C1; the same-named end of the primary side of the high-frequency transformer T is the positive voltage input end IN+ of the forward converter main circuit (1), which is connected to the positive output end of the external power supply, and the different-named end of the primary side of the high--frequency transformer T is connected to the drain of the switching tube S; the source of the switching tube S is the negative voltage input end IN of the forward converter main circuit (1), which is connected to the negative output end of the external power supply; the gate of the switching tube S is connected to the output end of the external controller; the same-named end of the secondary side of the high-frequency transformer T is connected to the anode of the diode Dl, the cathode of the diode D Iis connected to the cathode of the diode D2 and one end of the inductance
LI; the other end of the inductance Li is connected to one end of the capacitor C Iand is
the positive voltage output end OUT+ of forward converter main circuit (1); the
different-named end of the secondary side of the high-frequency transformer T is
connected to the anode of the diode D2 and the other end of the capacitor C1 and is the
negative voltage output end OUT- of the forward converter main circuit (1); the negative
voltage output end OUT- of the forward converter main circuit (1) is grounded; the
energy transfer and transmission circuit (2) includes a diode D3, a capacitor C2, an
inductance L2, and a diode D4; the anode of the diode D3 is connected to the anode of
the diode D2, the cathode of the diode D3 is connected to the second end of the
capacitor C2, the first end of the capacitor C2 is connected to the anode of the diode D1,
one end of the inductance L2 is connected to the cathode of the diode D3, the other end
of the inductance L2 is connected to the positive voltage output end OUT+ of forward
converter main circuit (1), the anode of the diode D4 is connected to the first end of the
capacitor C2 of the energy transfer and transmission circuit (2), the cathode of the diode
D4 is connected to the second end of the capacitor C2.
[0010] In one embodiment, the diodes Di and D2 are fast recovery diodes.
[0011] In one embodiment, the switching tube S is a fully-controlled power
semiconductor device.
[0012] In one embodiment, the capacitor C2 is selected according to the first selection
step; wherein the steps of the first selection step include: step 101, selecting the
capacitance C2 of the capacitor C2 of energy storage; step 102, calculating the withstand voltageVC2. 1 0of the capacitor C2 of energy storage; step 103, selecting the capacitor of energy storage with a capacitance C2 and a withstand voltage greater than VC2.on
[0013] In one embodiment, the inductance L2 is selected according to the second
selection step; wherein the steps of the second selection step include: step 201, obtaining
the average value of the change in current flowing through the inductance L2 and the
average current of the inductance LI during the entire period; step 202, determining the
value range of the inductance L2 of the inductance L2; step 203, determining the
maximum current I.,max flowing through the inductance L2 according to the steps 201
and 202.
[0014] In one embodiment, the diode D3 and the diode D4 are selected according to
the third selection step; wherein the steps of the third selection step include: step 301,
calculating the maximum current ID3.maxflowing through the diode D3; step 302,
calculating the maximum withstand voltage VD3.maxof the diode D3; step 303, selecting
the diode according to the maximum current ID3.max flowing through the diode and the
maximum withstand voltage VD3.maxof the diode; step 304, calculating the maximum
current ID4.maxflowing through the diode D4; step 305, calculating the maximum
withstand voltage VD4.max of the diode D4; step 306, selecting the diode according to the
maximum current ID4.maxflowing through the diode and the maximum withstand voltage
VD4.maxof the diode.
[0015] Compared with the prior art, the present disclosure has the following advantages:
[0016] 1. the excitation energy is transferred to the load side, which improves the overall efficiency of the converter;
[0017] 2. the present disclosure has high working stability and reliability, and the circuit is simple, which not need for complex control schemes and has a wide promotion value;
[0018] 3. compared with reset of the auxiliary winding, secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor reduces the difficulty of transformer design;
[0019] 4.The capacitor of the energy transfer and transmission circuit of the present disclosure is provided with a unidirectional conductive diode in parallel, which could prevent C2 from being charged reverse, reduce reactive power, and further improve efficiency;
[0020] 5. the reverse recovery problem of diode D4 coule be eliminated, and the loss of diode could be reduced;
[0021] 6. inductance L2 can work in CCM, which is suitable for high power transmission;
[0022] 7. the energy transfer and transmission circuit of the present disclosure could
also transmit forward energy, distribute power transmission, further improve reliability,
and is more suitable for high-power applications.
[0023] 8. after the present disclosure being used in a switching power supply, the
working safety and reliability of the switching power supply are higher, the energy
transfer and transmission circuit could improve the energy utilization rate, which could
be widely used in the fields of computers, medical communications, industrial control,
aerospace equipment, etc. Therefore, the present invention has a higher value of
promotion and application;
[0024] In summary, the circuit structure of the present disclosure is simple, the
implementation is convenient and the cost is low. And, the working mode of the present
disclosure is simple, the working stability and reliability are high, the service life is long.
Moreover, the power consumption is low, the transformer utilization rate is high, the
energy transmission efficiency is high. Furthermore, the working safety and reliability of
the power supply of the switch could be improved, and the value of promotion and
application is high.
[0025] The above and other features, examples and their implementations are described
in greater detail in the description, the drawings, and the claims.
[0026] FIG. 1 is a circuit schematic diagram of the secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor of the present disclosure.
[0027] In the drawings:
[0028] 1: forward converter main circuit; 2: energy transfer and transmission circuit.
[0029] As shown in FIG. 1, in one embodiment, the present disclosure provides a secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor, comprising a forward converter main circuit 1; and an energy transfer and transmission circuit 2 connected to the forward converter main circuit 1; the forward converter main circuit 1 includes a high-frequency transformer T, a switching tube S, a diode D1, a diode D2, an inductance LI; and a capacitor C; the same-named end of the primary side of the high-frequency transformer T is the positive voltage input end IN+ of the forward converter main circuit 1, which is connected to the positive output end of the external power supply, and the different-named end of the primary side of the high--frequency transformer T is connected to the drain of the switching tube S; the source of the switching tube S is the negative voltage input end IN- of the forward converter main circuit 1, which is connected to the negative output end of the external power supply; the gate of the switching tube S is connected to the output end of the external controller; the same-named end of the secondary side of the high-frequency transformer T is connected to the anode of the diode D1, the cathode of the diode Dl is connected to the cathode of the diode D2 and one end of the inductance LI; the other end of the inductance LI is connected to one end of the capacitor Cl and is the positive voltage output end OUT+ of forward converter main circuit 1; the different-named end of the secondary side of the high-frequency transformer T is connected to the anode of the diode D2 and the other end of the capacitor C1 and is the negative voltage output end OUT- of the forward converter main circuit 1; the negative voltage output end OUT- of the forward converter main circuit 1 is grounded; the energy transfer and transmission circuit 2 includes a diode D3, a capacitor C2, an inductance L2, and a diode D4; the anode of the diode D3 is connected to the anode of the diode D2, the cathode of the diode D3 is connected to the second end of the capacitor C2, the first end of the capacitor C2 is connected to the anode of the diode D1, one end of the inductance L2 is connected to the cathode of the diode D3, the other end of the inductance L2 is connected to the positive voltage output end OUT+ of forward converter main circuit 1, the anode of the diode D4 is connected to the first end of the capacitor C2 of the energy transfer and transmission circuit 2, the cathode of the diode D4 is connected to the second end of the capacitor C2.
[0030] Specifically, the load RL is connected between the positive voltage output end OUT+ and the negative voltage output end OUT- of the forward converter main circuit 1. In the forward converter main circuit 1, both the inductance Li and the capacitor Cl are used for filtering.
[0031] In one embodiment, the diode D is a rectifier diode, and the diode D2 is a fast recovery diode. The diode D2 is used for freewheeling.
[0032] In one embodiment, the switching tube S is an NMOS switching tube.
[0033] The working principle of this embodiment is:
[0034] Before analyzing the working principle of this embodiment, it is assumed that
the forward inductance Li works in CCM, the auxiliary inductance L2 and the
transformer secondary inductance Lw2 work in DCM. The working principle of this
embodiment is analyzed in the present disclosure, which is divided into the off period
and the on period of the switching tube. In order to facilitate the introduction of the
principle, the convention is as follows: for C2, the voltage is assumed to be a forward
voltage when the left voltage of C2 is negative and the right voltage of C2 is positive,
the voltage is assumed to be a reverse voltage when the left voltage of C2 is positive and
the right voltage of C2 is negative.
[0035] 1. The working principle during the on period of the switching tube S
[0036] It is assumed that before the switching tube is switched on, the forward voltage
of C2 is the maximum value, the current of w2 and L2 is dropped to the minimum, the
current of Li is remained at zero. D3 is switched on, while D1, D2 and 4 is switched off.
[0037] Stage 1: D4 is switched off, the forward energy storage is released by C2
[0038] After the switching tube is switched on, the input voltage Vi is applied to across
the primary winding of the transformer. The input voltage coupled to the secondary
winding w2, the voltage at the top of secondary winding w2 of the transformer is positive and the voltage at the bottom of the secondary winding w2 of the transformer is negative. D1 is switched on, the forward energy is transmitted to the load through two loops: one is that the forward energy is transmitted to the load through D1 and L1, the current of Li is risen linearly; the other is that the forward energy is transmitted to the load through C2, D4 and L2, the forward energy storage of C2 is released from the maximum value, and the current curve of L2 is risen until the forward voltage of C2 is dropped to zero, and this stage is over. At this stage, D2, D3, and D4 is remained off.
[0039] Stage 2: D4 is switched on, the energy is transferred to the load through D4 and
L2
[0040] After the forward voltage of C2 being dropped to zero, D4 is switched on
naturally, C2 is short-circuited, and energy is transferred to the load through D4 and L2,
the current of L2 is kept increasing linearly. At the same time, D1 is remained on, and
the current of Li continues to be risen linearly until the next switch-off cycle arrives,
and the currents of Li and L2 are reached their maximum values. This stage is over. At
this stage, D4 is switched on at zero voltage.
[0041] 2. The working principle during the off period of the switching tube S
[0042] Stage 1: energy is provided to the load by the continuous flow of Li and L2 at
the same time
[0043] After the switching tube S is switched off, D3 is switched on, and the positive energy storage is provided to C2 by the secondary winding through D3, and the voltage across C2 is increased positively from zero. At the same time, the inductance L2 is freewheeled through D3, and the current of inductance L2 is dropped linearly. In this stage, D2 is switched on, L is freewheeled through D2 and provided energy to the load, and the current of inductance Li is decreased linearly until the current of Li is dropped to zero. This stage is over.
[0044] Stage 2: energy is provided to the load by the continuous flow of L2
[0045] After the current of inductance LI being dropped to zero, D2 is switched off,
D3 is remained on, excitation energy continues to be stored by C2, the forward voltage
of C2 is gradually increased, and the current coupled to the secondary winding is
decreased slowly. At the same time, the inductance L2 continues to be freewheeled
through D3. Until the next switch-on period comes, the current of L2 and the current
coupled to the secondary winding are both dropped to the minimum value, and the
voltage of C2 is reached the maximum value. This stage is over.
[0046] In this embodiment, the capacitor C2 is selected according to the first selection
step; the steps of the first selection step include:
[0047] step 101, selecting the capacitance C2 of the capacitor C2 of energy storage
4(1- d) 2 n 2 <C, < n2(1- d)2
according to the formula: L,,rc 2 2 Lf 2 (arcsin2)2
[0048] step 102, calculating the withstand voltageVC2,T.O of the capacitor C2 of energy
L( VC2,Ton - 'lni Lnun storage according to the formula: C2
[0049] In the formula above, the d is the duty ratio of the switching tube S, the n is the
turns ratio of the primary winding and the secondary winding of the high-frequency
transformer T, L,, is the excitation inductance of the primary winding of the
high-frequency transformer T, f is the operating frequency of the forward converter
main circuit 1, A is generally takes 0-8 2A:! 1 , the maximum excitation current of
excitation inductance Lm in a cycle isILm,max,and the minimum excitation current of
excitation inductance Lm isLm,min. The specific formulas are as follows:
I Lrn,rnx ~mta VidT L0,[i - cos(w(1- d)T)] S VdT i/~ Iid co(w(1 -d)T) L,,[1- Lnnrtn cos(w(1- d)T)]Cos n Lj C2
[0050] In the formula above, Vi is the input voltage of the forward converter main
circuit 1;
[0051] step 103, selecting the capacitor of energy storage with a capacitanceC 2 and a
withstand voltage greater thanVc2,Ton
[0052] In this embodiment, the inductance L2 is selected according to the second
selection step; wherein the steps of the second selection step include:
[0053] step 201, determining the value range of the inductance L2 of the inductance L2
according to the formulas as follows: - 72
L > 1VVT -dT C2 V-nVJ2V-nV (nV -V )- arecos " + Vc2 + 2Vc,2 r n nV 2 ,Ton+V- nV,) n
- 72
L2 1 dT C2 arccos V -nV 7 (nVc2,Tnl+V-nVO)/]
[0054] In the formula above, V is the output voltage of the forward converter main
circuit 1;
[0055] step 202, determining the maximum current TI2maxpassing through the
inductance L2 according to the following formula:
V V IL2,max I- + °v (1-d)T RL L2
[0056] The time for the voltage across capacitor C2 to be dropped to zero is calculated
according to the following formula:
tI =jL 2 C 2 arcos n I(n Vc2,ron + Vi - n VO
[0057] Before the voltage across the capacitor C2 has not been dropped to zero, the
expression of the current of inductance L2 is calculated according to the following
formula:
V -nVo 11 2 (t)= VC 2 Ton + V 0 2 n2 LC2
[0058] During the entire period, the average value of the change in current flowing
through the inductance L2 is calculated according to the following formula:
1 71 V V AILa =- iL 2 (t)dt+ I1-d T(dT -t) ° (1-d)2 T T 2L0 ] 2L1
[0059] The average current of the inductance Li is calculated according to the
following formula:
1 (V - nV )'LL In=+ V - nVo d7T 2T IL 1 2 2v 2 n2 n
[0060] step 203, determining the maximum current I2mm flowing through the inductance L2 according to the steps 201 and 202.
[0061] In this embodiment, the diode D3 and the diode D4 are selected according to the third selection step; the steps of the third selection step include:
[0062] step 301, calculating the maximum current ID3,max flowing through the diode D3
according to the following formula: D3,max - L2,max Lm,max
V V = - I -Al + °"(1-d)T RL L2
+ VidT L, [1- cos(w(1- d)T)]
[0063] In the formula above, ILI, is the maximum current flowing through the
primary winding of the high-frequency transformer T, 'L2 is the current flowing
through inductance L2;
[0064] step 302, calculating the maximum withstand voltageVD3,max of the diode D3
according to the following formula:
VD 3 =V + '' - = -"(I2, _J2 +''"" n CT 2 n
[0065] step 303, selecting the diode according to the maximum current ID3,maxflowing through the diode and the withstand voltageVD3.maxof the diode;
[0066] step 304, calculating the maximum current ID4,max flowing through the diode D4
according to the following formula:
D4,max - L2,max
L IL-AL2 +(1 d)T RL L2
[0067] step 305, calculating the maximum withstand voltage V4,max of the diode D4
according to the following formula:
VD4,max C2,Ton Lm,max Lm,min
[0068] step 306, selecting the diode according to the maximum current D4,max flowing
through the diode and the withstand voltage V4,max of the diode.
[0069] It should be understood that the above description is merely to illustrate the
feasibility of the technical solution of the present disclosure, and the principles and
corresponding formulas of one of the listed working modes are not the only and limited
descriptions, and are only used for reference.
[0070] It should be particularly noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, not to limit them. For those skilled in the art, the technical solutions described in the above embodiments may be modified, or some of the technologies features are equivalently replaced; and all these modifications and replacements should fall within the scope of protection of the appended claims of the present disclosure.
Claims (7)
1. A secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor, comprising: a forward converter main circuit (1); and an energy transfer and transmission circuit (2) connected to the forward converter main circuit (1); wherein, the forward converter main circuit (1) includes: a high-frequency transformer T; a switching tube S; a diode D1; a diode D2; an inductance LI; and a capacitor C1; and wherein, the same-named end of the primary side of the high-frequency transformer T is the positive voltage input end IN+ of the forward converter main circuit (1), which is connected to the positive output end of the external power supply, and the different-named end of the primary side of the high--frequency transformer T is connected to the drain of the switching tube S; the source of the switching tube S is the negative voltage input end IN- of the forward converter main circuit (1), which is connected to the negative output end of the external power supply; the gate of the switching tube S is connected to the output end of the external controller; the same-named end of the secondary side of the high-frequency transformer T is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the cathode of the diode D2 and one end of the inductance LI; the other end of the inductance LI is connected to one end of the capacitor Cl and is the positive voltage output end OUT+ of forward converter main circuit (1); the different-named end of the secondary side of the high-frequency transformer T is connected to the anode of the diode D2 and the other end of the capacitor Cl and is the negative voltage output end OUT- of the forward converter main circuit (1); the negative voltage output end OUT- of the forward converter main circuit (1) is grounded; wherein, the energy transfer and transmission circuit (2) includes: a diode D3; a capacitor C2; an inductance L2; and a diode D4; and wherein, the anode of the diode D3 is connected to the anode of the diode D2, the cathode of the diode D3 is connected to the second end of the capacitor C2, the first end of the capacitor C2 is connected to the anode of the diode D1, one end of the inductance L2 is connected to the cathode of the diode D3, the other end of the inductance L2 is connected to the positive voltage output end OUT+ of forward converter main circuit (1), the anode of the diode D4 is connected to the first end of the capacitor C2 of the energy transfer and transmission circuit (2), the cathode of the diode D4 is connected to the second end of the capacitor C2.
2. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 1, wherein the diodes D1 and D2 are fast recovery diodes.
3. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 1, wherein the switching tube S is a fully controlled power semiconductor device.
4. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 1, wherein the capacitor C2 is selected according to the first selection step; wherein the steps of the first selection step include:
step 101, selecting the capacitance C2 of the capacitor C2 of energy storage;
step 102, calculating the withstand voltage VC2,on of the capacitor C2 of energy
storage;
step 103, selecting the capacitor of energy storage with a capacitance C2 and a
withstand voltage greater than Vc2,on .
5. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 4, wherein the inductance L2 is selected according to the second selection step; wherein the steps of the second selection step include: step 201, obtaining the average value of the change in current flowing through the inductance L2 and the average current of the inductance Li during the entire period; step 202, determining the value range of the inductance L2 of the inductance L2; step 203, determining the maximum current I2max flowing through the inductance
L2 according to the steps 201 and 202.
6. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 4, wherein the diode D3 and the diode D4 are selected according to the third selection step; wherein the steps of the third selection step include:
step 301, calculating the maximum current ID3.max flowing through the diode D3;
step 302, calculating the maximum withstand voltage VD 3 .ax of the diode D3;
step 303, selecting the diode according to the maximum current IsD3max flowing
through the diode and the maximum withstand voltage VD3.max of the diode;
step 304, calculating the maximum current ID4max flowing through the diode D4;
step 305, calculating the maximum withstand voltage VD 4 Iax of the diode D4;
step 306, selecting the diode according to the maximum current ID4max flowing
through the diode and the maximum withstand voltage VD4max of the diode.
7. The secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor as in claim 5, wherein the diode D3 and the diode D4 are selected according to the third selection step; wherein the steps of the third selection step include:
step 301, calculating the maximum current IsD3max flowing through the diode D3;
step 302, calculating the maximum withstand voltage VD 3 .ax of the diode D3;
step 303, selecting the diode according to the maximum current IsD3max flowing
through the diode and the maximum withstand voltage VD3.max of the diode; step 304, calculating the maximum current ID4,max flowing through the diode D4; step 305, calculating the maximum withstand voltageVD4,.maX of the diode D4; step 306, selecting the diode according to the maximum current ID4,.max flowing through the diode and the maximum withstand voltageVD4,.maX of the diode.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010490672.0 | 2020-06-02 | ||
| CN202010490672.0A CN111682777B (en) | 2020-06-02 | 2020-06-02 | Secondary parallel LCD forward converter capable of avoiding reverse charging of energy storage capacitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU2020220124B1 true AU2020220124B1 (en) | 2021-08-12 |
Family
ID=72453844
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2020220124A Active AU2020220124B1 (en) | 2020-06-02 | 2020-08-19 | Secondary parallel lcd forward converter capable of avoiding reverse charging of energy storage capacitor |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111682777B (en) |
| AU (1) | AU2020220124B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113037093B (en) * | 2021-03-16 | 2022-12-09 | 西安科技大学 | Forward converter with secondary rectifier diode connected with capacitor in parallel and system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5641769A (en) * | 1979-09-12 | 1981-04-18 | Nippon Telegr & Teleph Corp <Ntt> | One transistor type converter |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6333861B1 (en) * | 2000-06-06 | 2001-12-25 | Astec International Limited | Low loss snubber and transformer reset circuit for forward converters |
| US6947297B2 (en) * | 2003-10-04 | 2005-09-20 | Delta Electronics, Inc. | Active resonant snubber for DC-DC converter |
| CN102497106A (en) * | 2011-12-05 | 2012-06-13 | 北京新雷能科技股份有限公司 | Single-end forward power inverter |
| CN105703627B (en) * | 2016-05-03 | 2018-05-08 | 西安科技大学 | The design method of secondary simplex winding Self-resetting forward conversion circuit |
| JP2018121390A (en) * | 2017-01-23 | 2018-08-02 | Ntn株式会社 | Switching power supply |
| JP6840032B2 (en) * | 2017-05-22 | 2021-03-10 | Ntn株式会社 | Insulated switching power supply |
-
2020
- 2020-06-02 CN CN202010490672.0A patent/CN111682777B/en active Active
- 2020-08-19 AU AU2020220124A patent/AU2020220124B1/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5641769A (en) * | 1979-09-12 | 1981-04-18 | Nippon Telegr & Teleph Corp <Ntt> | One transistor type converter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111682777A (en) | 2020-09-18 |
| CN111682777B (en) | 2022-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106169873A (en) | It is applicable to mixing connection in series-parallel full-bridge circuit and the control method thereof of high pressure or High-current output | |
| CN102237799A (en) | Three-level resonant converter clamped by resonant capacitor and transformer primary side | |
| CN103840670A (en) | Energy-saving type high-frequency switching power source | |
| CN101478252B (en) | X-high frequency chain inverter without DC filtering stage | |
| US20140192562A1 (en) | Single stage ac/dc converter | |
| CN112087140B (en) | Multi-mode automatic switching two-stage resonance DC-DC converter | |
| US11323037B2 (en) | Forward converter with secondary LCD connected in series to realize excitation energy transfer | |
| CN106533181A (en) | Double transformer parallel series LLC resonant DC-DC converter and control method of the same | |
| CN114884365A (en) | Three-phase converter | |
| CN108347174B (en) | Boost full-bridge isolated converter and composite active clamping circuit thereof | |
| AU2020220124B1 (en) | Secondary parallel lcd forward converter capable of avoiding reverse charging of energy storage capacitor | |
| CN111181411B (en) | Variable/fixed bus voltage ultra-wide gain range bidirectional dc/dc converter | |
| US11342850B2 (en) | Forward converter with secondary LCD connected in parallel to realize forward and backward energy transmission | |
| CN111193421A (en) | Three-phase isolation AC-DC converter | |
| CN111682776B (en) | Secondary-side parallel LCD forward converter capable of inhibiting output energy from flowing backwards | |
| EP3920401A1 (en) | Secondary series lcd excitation energy transfer forward converter capable of suppressing output energy backflow | |
| CN115459605A (en) | Three-phase DC-DC converter | |
| CN114884346A (en) | High-frequency isolation three-phase bidirectional converter | |
| CN114900048A (en) | Three-phase bidirectional DC-DC converter | |
| CN103701330B (en) | A kind of large-power boost circuit with high transformation ratio | |
| CN113691141A (en) | Topological structure of DC-DC converter | |
| CN208445496U (en) | A kind of super high power narrow-pulse semiconductor Laser Power Devices | |
| CN111245250A (en) | High-performance flyback switching power supply circuit and working method thereof | |
| CN112202334A (en) | Two-stage DC/DC converter for wide-input high-efficiency ultrathin module power supply | |
| CN111371195A (en) | Power conversion circuit for LCC-S wireless power transmission system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) |