KR101492964B1 - SLLC Resonant Converter for Bidirectional Power Conversion using auxiliary switches and inductor - Google Patents

Abstract

Disclosed is an SLLC resonant converter for bidirectional power conversion in a DC-DC converter capable of bidirectional power conversion which boosts a low voltage to a high voltage and lowers a low voltage to a high voltage. The SLLC resonant converter of the present invention comprises: a primary side terminal connected to a primary side input terminal to apply the primary side input voltage to a first coil of a transformer in a forward operation and thereby inducing a current variation and connecting a primary side auxiliary inductor to the first coil in parallel in a backward operation to allow the current variation induced through the primary side auxiliary inductor to have an LLC resonance characteristic with a leakage inductance of the primary coil and a second coil of the transformer and a resonance capacitor connected to the second coil and thereby charging the primary side input voltage; and a secondary side terminal connected to a secondary side output voltage having a voltage level higher than that of the primary side input voltage to apply divided secondary side output voltage to each second coil of the transformer and the resonance capacitor, and a secondary side auxiliary inductor connected to the second coil of the transformer and the resonance capacitor in a backward operation to induce a current variation, and to connect the leakage inductance of the first coil and the second coil of the transformer, the resonance capacity connected to the second coil of the transformer, and the secondary side auxiliary inductor in a forward operation to allow the current variation induced in the second coil of the transformer to have the LLC resonance characteristic by the current variation of the first coil, thereby charging the secondary output voltage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an SLLC resonant converter for bidirectional power transfer,

The present invention relates to a bidirectional power-supplyable DC-DC converter, and more particularly to a bidirectional power-supplyable DC-DC converter that boosts a first voltage, a high voltage to a high voltage, and a low voltage to a high voltage.

In this paper, we propose a new method for the conversion of energy storage system into a DC / DC converter, such as PCS (Power Conditioning System) and electric vehicle. Since the energy storage system (ESS) requires a high efficiency and safety, it is required to use a bidirectional power supply with a voltage source converter or a current source converter in a bidirectional power-capable DC / DC converter using an insulated high frequency transformer A possible DC / DC converter has been developed.

In order to reduce the size, switching loss and EMI (Electro-Magnetic Interference), a bi-directional power-capable DC / DC converter incorporating a soft switching LLC resonant converter is being applied.

FIG. 1 is a diagram showing an example of a conventional LLC resonant converter. The LLC resonant converter at this time is capable of zero voltage switching (ZVS) and zero current switching (ZCS) operations, Up / down control can be performed based on the frequency point (fs / fr = Fn (f) = fn = 1), so output voltage control and power control can be performed through switching frequency operation control corresponding to a given input voltage control range and load range can do.

However, in order to enable bi-directional power transfer, resonant capacitors Cr1 and Cr2 (or CB1) are applied to the primary and secondary sides of the LLC resonant converter capable of bidirectional power transfer. As shown in FIGS. 3 and 4, The forward and reverse power transfer operations have different operation characteristics from the conventional LLC resonant converter gain characteristics of FIG. 2 according to the values of the secondary side resonance capacitor and the secondary side resonance capacitor.

Therefore, in order to have LLC resonance characteristics in an isolated bidirectional DC / DC converter in both bidirectional power conversion operations, Korean Patent Application No. 10-2012-0133728 (entitled SLLC for Bi- Modification of auxiliary inductor and auxiliary switch or circuit configuration such as resonant converter (Nov. 23, 2012) and Korean Patent Application No. 10-2013-0000730 (invention name: bi-directional power conversion DC-DC converter (2013, 01.03) A supplementary patent has been filed.

Particularly, Korean Patent Application No. 10-2012-0133728 discloses a method of controlling a resonant frequency of a resonant circuit, 6, the resonant capacitor Cs is applied to the high voltage end of the secondary side without applying the resonance capacitor at the low voltage end of the primary side, and the resonance capacitor Cs is connected to the primary side low voltage end converter terminal (a, b) Auxiliary circuit 1, in which a primary side of the transformer, a primary side auxiliary inductor L _A1 and a primary side bidirectional auxiliary switching device S _A1 , S _A2 are connected in series, is connected, and a primary side bidirectional auxiliary switching device The primary side auxiliary inductor L _A1 is connected in parallel with the primary side of the transformer in accordance with the turn-on / off operation of the _switches S _A1 and S _A2 .

An auxiliary circuit 2 connected in series with the secondary side auxiliary inductor L _A2 and the secondary side bidirectional auxiliary switches S _A3 and S _A4 is connected to the secondary side high voltage side converter terminals c and d, And the secondary side of the transformer and the resonance capacitor (C _s ) are connected in parallel with the secondary side resonance part connected in series. The secondary side auxiliary inductor L _A2 is connected in parallel with the converter terminals c and d and the secondary side resonance part in accordance with the turn-on / off operation of the secondary side bidirectional auxiliary switching elements S _A3 and S _A4 .

Therefore, during the forward power transfer operation, the primary side switching devices [Q ₁ , Q ₄ , Q ₂ , Q ₃ ] are alternately operated with a 50% duty and the secondary side switching devices [Q ₅ , Q ₈ ] , [Q ₆ , Q ₇ ]) are both turned off and operated as rectifier diodes through the secondary-side antiparallel diode. At this time, during the forward power transfer operation, the primary side auxiliary switching elements S _A1 and S _A2 are turned off It operated and the secondary-side auxiliary switch (S _A3, S _A4) is turned is turned on and operated, so the primary side resonance current to be operated with a large current at the primary side low voltage terminal (I _T1) is the primary side auxiliary switch (S _A1, S _A2 The resonance current I _T1 flows through the secondary side auxiliary circuit (Auxiliary circuit 2) together with the primary side switching elements Q ₁ , Q ₂ , Q ₃ and Q ₄ and the primary winding of the transformer T ₁ The leakage inductance of the primary side transformer leakage inductance and the secondary side winding transformer leakage inductance, the resonance capacitor (C _s ) located at the secondary side, the secondary side auxiliary inductor L _{A 2} ) are used to exhibit LLC resonance characteristics on the secondary side.

The secondary-side switching element when the reverse power transmission operation _{([Q 5, Q 8]} , [Q 6, Q 7]] is operated in alternation with a 50% duty, the primary side switching element _{([Q 1, Q 4]} , [Q ₂ , Q ₃ ]) are both turned off and operated as rectifier diodes through the primary side anti-parallel diodes.

At this time, the auxiliary switches S _A3 and S _A4 located on the secondary side of the resonant converter are not operated to turn off the primary side auxiliary switches S _A1 and S _A2 in order to have the LLC resonance gain characteristic of FIG. And the secondary side resonant current I _T2 during the alternating switching operation of the secondary side switching elements Q ₅ , Q ₈ , Q ₆ and Q ₇ is generated by the resonant capacitor C _s , the transformer T _{1) 1,} 2-side leakage inductance and the primary-side auxiliary inductor (L _A2) and the primary auxiliary switch (S _A3, the current flowing through the S _A4) (I _A1) and a power supply (resonance current flowing to the V _in) (I _T1 ), the LLC resonance characteristics at the secondary side are obtained by using the resonance characteristics between the leakage inductance of the secondary winding transformer and the leakage inductance of the primary winding transformer, the resonant capacitor C _s located at the secondary side, and the primary side auxiliary inductor L _A1 Lt; / RTI >

In the Forward Operation Mode of the proposed SLLC resonant converter for bidirectional power transfer, the output voltage V (V _in ) set at the highest input voltage (V _in ) during power transfer from the primary input to the secondary output _o) the normalized screen with the resonant frequency of 7 when you want to control _{(f s / f r = f} n (f) = f n) set so that the switching from the discrete interval of the point or slightly below, and enter the primary voltage (V _in) and the low voltage that is by increasing the gain sikimeuro move the switching frequency at a low frequency of the secondary side output voltage (V _o) via a variable frequency control controls the constant voltage, and power.

In the reverse operation mode, when the power is transferred from the secondary side output voltage (V _o ) to the primary side input voltage (V _in ), the input voltage of the transformer set by the input / output voltage condition of the forward power transfer operation mode , The secondary side output voltage (V _o ) is always set to a fixed voltage in the reverse operation mode according to the operation of the PWM inverter connected to the power system as shown in FIG. 8, so that the reverse power transmission In the operation mode, the primary side input voltage V _in is set to the highest voltage at the normalized resonance frequency f _s / f _r = F _n (f) = f _n of the gain characteristic shown in FIG. 7 For gain adjustment at a lower voltage, the gain should be lowered by switching to a frequency higher than the normalized resonant frequency (f _s / f _r = F _n (f) = f _n ). However, as shown in the gain characteristic of FIG. 7 measure The gain control is limited by the variable switching frequency control because the gain change is not particularly large at the resonant frequency (f _s / f _r = F _n (f) = f _n ) There is a problem that the efficiency is reduced, for example, the circulating resonance current increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an auxiliary switch having a simplified structure and an SLLC resonance converter for bidirectional power transfer applied to an inductor while performing gain control more easily and improving efficiency.

According to an aspect of the present invention, there is provided an auxiliary switch and an inductor-applied SLLC resonant converter for receiving bidirectional power, the auxiliary switch being connected to a primary input voltage, A first auxiliary inductor connected in parallel to a first winding end of the transformer in a reverse direction to apply a current change to the first winding end of the transformer, And a primary side terminal for charging the primary side input voltage by having a resonance capacitor and a LLC resonance characteristic connected to the second winding end of the transformer and the leakage inductance of the second winding end, And a secondary side output voltage having a voltage level higher than that of the primary side input voltage. The secondary side output voltage of the secondary side is connected to the second winding end of the transformer, the second winding end of the transformer, And a resonance capacitor connected to a first winding end and a second winding end leakage inductance of the transformer and a second winding end of the transformer in a forward operation mode; and a resonance capacitor connected between the first winding end and the second winding end leakage inductance of the transformer, A secondary side end connected to the secondary side auxiliary inductor to charge the secondary side output voltage by changing the current induced in the second winding end of the transformer by the current change of the first winding end of the transformer to have an LLC resonance characteristic; .

In accordance with another aspect of the present invention, there is provided an auxiliary switch and an inductor-applied SLLC resonant converter for receiving bidirectional power, the auxiliary switch being connected to a primary input voltage, Wherein a current change induced by a first winding stage and a magnetization inductance of the transformer during a reverse operation is determined by a leakage inductance of a first winding end and a second winding end of the transformer, A resonance capacitor connected to a second winding end of the transformer and a primary side end charged with the primary side input voltage by having an LLC resonance characteristic; And a secondary side output voltage having a voltage level higher than that of the primary side input voltage. The secondary side output voltage of the secondary side is connected to the second winding end of the transformer, the second winding end of the transformer, And a resonance capacitor connected to a first winding end and a second winding end leakage inductance of the transformer and a second winding end of the transformer in a forward operation mode; and a resonance capacitor connected between the first winding end and the second winding end leakage inductance of the transformer, A secondary side end connected to the secondary side auxiliary inductor to charge the secondary side output voltage by changing the current induced in the second winding end of the transformer by the current change of the first winding end of the transformer to have an LLC resonance characteristic; And the transformer has an air gap for reducing the magnetization inductance.

The auxiliary switch of the present invention and the inductor-applied SLLC resonant converter for bidirectional power transfer enable simplified bi-directional power transfer using the bidirectional auxiliary switch and the inductor at the secondary side, thereby reducing the size and lowering the manufacturing cost .

1 shows an example of a conventional bidirectional DC / DC converter.
FIGS. 2 to 4 show resonance characteristics of the bidirectional DC / DC converter of FIG. 1. FIG.
5 shows an example of a conventional SLLC resonant converter.
6 shows another example of a conventional bidirectional DC / DC converter.
7 shows the gain characteristics of an SLLC resonant converter according to a conventional bidirectional DC / DC converter.
FIG. 8 is a diagram illustrating a conventional bidirectional power-supplyable SLLC resonant converter and a power grid-connected PWM inverter main circuit.
9A and 9B show an embodiment of a bidirectional SLLC resonant converter according to the present invention.
10 is a waveform diagram for the forward operation of the bidirectional SLLC resonant converter of FIG. 9A.
11 is a diagram for explaining the forward operation of the bidirectional SLLC resonant converter of FIG.
FIG. 12 is a waveform diagram for the reverse operation of the bidirectional SLLC resonant converter of FIG. 9A.
13 is a diagram for explaining the reverse operation of the bidirectional SLLC resonant converter of FIG.
Figure 14 shows another embodiment of a bidirectional SLLC resonant converter according to the present invention.
15 is a waveform diagram for the forward operation of the bidirectional SLLC resonant converter of Fig.
16 is a diagram for explaining the forward operation of the bi-directional SLLC resonant converter of FIG.
Fig. 17 is a waveform diagram for the reverse operation of the bidirectional SLLC resonant converter of Fig. 14; Fig.
FIG. 18 is a diagram for explaining the backward operation of the bi-directional SLLC resonant converter of FIG.
Figs. 19-21 illustrate still another embodiment of a bidirectional SLLC resonant converter according to the present invention.
22 shows structural examples of a bidirectional auxiliary switching element part in a bi-directional SLLC resonant converter according to the present invention.
Figures 23-25 illustrate the waveforms and efficiencies observed in the forward and reverse operation of the bidirectional SLLC resonant converter of Figure 9A.
Figs. 26 and 27 show waveforms observed in the forward operation of the bidirectional SLLC resonant converter of another embodiment of Fig. 14 and in the experimental results in the reverse operation.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. However, the present invention can be implemented in various different forms, and is not limited to the embodiments described. In order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals in the drawings denote the same members.

Throughout the specification, when an element is referred to as "including" an element, it does not exclude other elements unless specifically stated to the contrary. The terms "part", "unit", "module", "block", and the like described in the specification mean units for processing at least one function or operation, And a combination of software.

Figure 9A illustrates one embodiment of a bi-directional SLLC resonant converter in accordance with the present invention.

9A is a full bridge bidirectional SLLC resonant converter that includes a primary side input voltage V _in and a secondary side output voltage V _in . V _o ), a primary side end 110, and a secondary side end 120. [ Here, the primary side input voltage V _in and the secondary side output voltage V _o may be implemented by a battery, a DC voltage, etc., and the primary side input voltage V _in may be higher than the secondary side output voltage _Vo by a voltage level .

The primary side 110 is connected in parallel with the primary side input voltage V _in and the primary side capacitor C _in connected in parallel with the primary side input voltage V _in and acts as a full bridge converter during forward operation. A primary side converter 111 having first to fourth switching elements Q ₁ , Q ₂ , Q ₃ and Q ₄ which are turned off in the reverse direction and both ends of the primary side converter 111 (A) of the first and second switching elements Q1 and Q2 and a contact b of the third and fourth switching elements Q3 and Q4) and is connected between both ends of the primary side converter a primary side auxiliary circuit part 112 for connecting the primary side auxiliary inductor L _A1 in parallel to the primary side inductor a and b and a rectifier circuit connected between both ends a and b of the primary side converter 111, the first coil end (a first winding of the transformer (TR) during the induction current change through the N ₁₎ and the reverse motion stage (N ₁₎ and the primary current is derived from the auxiliary inductor (L _A1) of TR) Change And a primary resonance part 113 for charging the primary side input voltage V _in so as to have the LLC resonance characteristic.

However, the first to fourth switching elements Q ₁ , Q ₂ , Q ₃ and Q ₄ of the primary side converter 111 are all turned off in the reverse direction and the first to fourth switching elements Q ₁ and Q ₂ , Q ₃ , and Q ₄ ), and charges the primary side input voltage. However, when the rectifying operation is performed using the anti-parallel diode, the power efficiency is unnecessarily reduced Problems can arise.

In the present invention, when current flows through the anti-parallel diodes of the first through fourth switching devices Q ₁ , Q ₂ , Q ₃ and Q ₄ , the first through fourth switching devices Q ₁ , Q ₂ and Q ₃ , Q ₄ ) operate in the form of a synchronous rectifier that is momentarily turned on in synchronization with the current flowing through its anti-parallel diode, thereby preventing the occurrence of such a problem in advance.

The primary side capacitor C _in is connected in parallel with the primary side input voltage V _in between the primary side first node Nd 11 and the primary side second node Nd 12 to stabilize the primary side input voltage V _in do. The primary capacitor C _in may be removed as the case may be.

The primary side converter 111 is connected in parallel with the primary input voltage V _in between the primary side first node Nd11 and the primary side second node Nd12 and is connected in parallel to the primary side input voltage V _in , And switching elements Q ₁ , Q ₂ , Q ₃ , and Q ₄ . More specifically, the first and second switching devices Q ₁ and Q ₂ and the first and second switching devices Q ₁ and Q ₂ connected between the primary side first node Nd 11 and the primary side second node Nd ₁₂ , Q may be of a _second) and the first node (Nd11 primary side parallel to) the primary-side second node (the third and fourth switching elements (Q _3, Q ₄₎ coupled between Nd12).

The primary side auxiliary circuit part 112 is connected between the contact point a of the first and second switching elements Q1 and Q2 and the contact point b of the third and fourth switching elements Q3 and Q4, And the primary side auxiliary inductor L _A1 is connected to both ends a and b of the primary side converter 111 only in the reverse direction to the primary side auxiliary inductor L _A1 Directional auxiliary switching elements (S _A1 , S _A2 ). The bidirectional auxiliary switching elements S _A1 and S _A2 have opposite polarities and can be implemented by two switches connected in parallel, but this can be modified in various ways as shown in FIG. 9B). In some cases (for example, when the primary side auxiliary inductor L _A1 desires to connect the both ends a and b of the primary side converter 111 even in the reverse direction as well as in the forward direction) The bidirectional auxiliary switching elements S _A1 and S _A2 of the primary side 100 may be removed.

1 resonance unit 113 at both ends (a, b) to be connected in parallel with the primary winding a secondary circuit (112) between the primary winding ends of the transformer (TR), (N ₁₎ of the primary converter 111, Respectively. At this time, L _l1 in Figure 9a represents the leakage inductance of the primary winding stage (N _1). (Note that the transformer magnetization inductance Lm1 is not assumed to be large).

The secondary side 120 includes secondary side first and second capacitors C _o1 and C _o2 connected in parallel to the secondary side output voltage V _o and secondary side first and second capacitors C _o1 and C _o2 A secondary side converter 121 connected in parallel to the first and second switching elements Q ₅ and Q ₆ connected in a full bridge structure and first and second diodes D ₇ and D ₈ , (D) of the first and second diodes D ₇ and D ₈ and the contact e of the secondary side first and second capacitors C _o1 and C _o2 , and a second diode (d _7, d _8), the contact (d)) and the secondary side first and second capacitors (C _o1, the secondary-side converter (121 to release the connection of the contact (e) of C _o2) a) is (D) of the first and second diodes D ₇ and D ₈ and the contacts e of the secondary side first and second capacitors C _o1 and C _o2 during the reverse operation, Side secondary switch 121 to be switched to a half-wave resonance circuit by connecting the secondary side converter 121 Unit 122, a secondary-side converter 121, the ends (c, d) on two ends of the secondary side resonance part 123 and the secondary side auxiliary inductor connected in parallel (L _A2), the secondary-side converter (121) between (c and d in the forward direction and the change in current induced through the second winding end N ₂ of the transformer TR, the resonant capacitor C _S , and the secondary side inductor L _A2 , to have the secondary side output voltage (V _o) charge and the reverse during operation, the second winding of the partial pressure of the secondary side output voltage (V _o / 2) the transformer (TR) stage to (N ₂₎ and the resonant capacitor (C _S Side secondary inductor L _A2 connected in parallel to the second winding end N ₂ of the transformer TR and the resonance capacitor C _S to apply a current change to the secondary side resonance unit 123 Respectively.

The secondary side first and second capacitors C _o1 and C _o2 are connected in parallel with the second voltage V _o between the secondary side first node Nd21 and the secondary side second node Nd22, And divides the output voltage (V _o ).

The secondary side converter 121 includes fifth and sixth switching elements Q ₅ and Q ₆ connected in a full bridge structure between the secondary side first node Nd 21 and the secondary side second node Nd ₂₂ , 2 diodes D ₇ and D ₈ . More specifically, the fifth and sixth switching elements Q ₅ and Q ₆ connected in series between the secondary side first node Nd 21 and the secondary side second node Nd ₂₂ , the secondary side first node Nd 21, And first and second diodes D ₇ and D ₈ connected in parallel with the fifth and sixth switching elements Q ₅ and Q ₆ between the secondary side second node Nd 22. That is, it can be seen that the secondary side converter 121 of the present invention is constituted by replacing some of the four switching elements constituting the full bridge converter with diodes.

The secondary side bidirectional auxiliary switching unit 122 is connected between the contact d of the first and second diodes D ₇ and D ₈ and the contact e of the secondary side first and second capacitors C _o1 and C _o2 Directional auxiliary switching elements S _A3 and S _A4 connected to the secondary side bi-directional auxiliary switching elements S _A3 and S _A4 . The bidirectional auxiliary switching devices S _A3 and S _A4 may be implemented by two switches having opposite polarities and connected in parallel, but this may be modified as shown in FIG.

A secondary side resonance part 123 is the resonance capacitor (C _s) and the first and second diodes (D _7, D ₈₎ and the secondary-side winding stage (N ₂₎ of the transformer (TR) is connected between the contact point (d) of And a resonance capacitor C _s connected to the contact c of the fifth and sixth switching elements Q ₅ and Q ₆ . Ratio (n) of L _l2 in Figure 9a represents the leakage inductance of the secondary winding end (N _2), first and second winding ends of the transformer _{(TR) (N 1, N} 2) are N ₂ / N ₁ to be.

As described above, in the present invention, the high current resonance capacitor C _s is applied to the high voltage end of the secondary side without using the high current resonance capacitor C _s at the low input voltage end of the primary side. To obtain the LLC resonant voltage gain characteristic, a secondary side auxiliary inductor (L _A2 ) is added to the secondary side 120 so that the LLC resonance characteristic appears on the secondary side, which is the high voltage side.

FIG. 10 is a waveform diagram for a forward operation of a bidirectional SLLC resonant converter according to an embodiment of the present invention, and FIG. 11 is a diagram for explaining a forward operation of the bidirectional SLLC resonant converter according to an embodiment of the present invention.

Referring to FIG. 10, in the forward operation of the bidirectional SLLC resonant converter, the first and fourth switching devices Q ₁ and Q ₄ and the second and third switching devices Q ₂ and Q ₃ have a duty ratio of 50% And turns off the primary side bidirectional auxiliary switching devices S _A1 and S _A2 . That is, the resonant current does not flow to the primary side auxiliary inductor L _A1 in accordance with the switching operation of the first to fourth switching devices Q ₁ to Q ₄ , and only the primary side coil N ₁ of the transformer TR Let it flow.

At the same time, the fifth and sixth switching elements Q ₅ and Q ₆ are also turned off, the secondary side bidirectional auxiliary switching elements S _A3 and S _A4 are turned off, Side resonant current through the full-wave rectifying circuit composed of the anti-parallel diodes of the switching elements Q ₅ and Q ₆ and the first and second diodes D ₇ and D ₈ .

Hereinafter, the forward operation of the bidirectional SLLC resonant converter of the present invention will be described with reference to FIG. 11 as follows.

The first and fourth switching elements Q _{1 and} Q ₄ of the first side 100 are turned on and the second and third switching elements Q _{2 and} Q ₃ are turned on in the operating mode t ₁ to t ₂ The primary side resonance current I _T1 flows through the first switching device Q ₁ , the primary winding N ₁ of the transformer TR and the fourth switching device Q ₄ .

The second side end 100 in the resonance current in the secondary winding end (N ₂₎ of the transformer (TR) is derived, the secondary side is guided to the winding end (N _2), a resonance capacitor (C _S) flowing through the resonance current through the The secondary side resonance current I _T2 flows to the second voltage V _o through the current path formed through the anti-parallel diode of the fifth switching device Q ₅ and the second diode D ₈ .

In addition, the secondary-side winding stage (N ₂₎ downstream of the excitation current induced in the resonant current (I _A2) to flow into the secondary-side auxiliary inductor (L _A2). That is, the resonant current is induced corresponding to the sum of the secondary-side winding stage (N _2), the secondary side resonant current (I _T2) and a secondary side excitation current (I _A2) by a primary-side resonant current (I _T1) [I _T1 = n (I _A2 + I _T2 ), n = (N ₂ / N ₁ )].

In the mode of operation (t ₂ ~ t ₃₎ the first to fourth switching elements _{(Q 1, Q 2, Q} 3, Q 4) is, but maintains a previous state, the longer the time that is a resonant current (I _T1) the primary winding ends of the transformer (TR) (N ₁₎ there is not a change in current occurs, the secondary winding ends of the transformer (TR) (N _2), the secondary side resonance current further (I _T2) according to the Induced.

Although the secondary side output voltage V _o is connected to the secondary side 120 of the resonance converter unit 100, the reverse parallel diode of the fifth switching device Q ₅ and the second diode D ₈ The current path formed through the secondary side auxiliary inductor L _A2 disappears, and only the current path formed through the secondary side auxiliary inductor L _A2 remains.

In the secondary side to the excitation current (I _A2), only a secondary side auxiliary inductor flows to the (L _A2), the resonant current induced in the secondary winding ends of the transformer (TR) (N ₂₎ is a secondary side excitation current (I _A2) Lt; / RTI >

In the operation mode (t ₄ to t ₅ ), the first and fourth switching devices Q _{1 and} Q ₄ are turned off again, and the second and third switching devices Q _{2 and} Q ₃ are turned on, The current I _T1 flows through the second and third switching elements Q _{2 and} Q ₃ instead of the first and fourth switching elements Q ₁ and Q ₄ .

The secondary winding ends of the transformer (TR) by a primary-side resonant current (I _T1) having a changed orientation (N ₂₎ there are resonant current is induced, is induced in the secondary winding end (N ₂₎ a resonance capacitor (C _S ) the secondary side resonant current (I _T2 of the flowing resonance current through) the sixth switching element (the second voltage through a current path formed of the antiparallel diode of Q ₆₎ and via a first diode (D _7), (V _o) And the secondary-side exciting current I _A2 flows to the secondary-side auxiliary inductor L _A2 .

That is, it is susceptible to the sum of the primary-side resonant current (I _T1) the secondary side winding stage (N ₂₎ the resonant current back to the secondary-side resonant current (I _T2) and a secondary side excitation current (I _A2) induced by the.

In the operation mode t ₅ to t ₆ , the second to third switching devices Q ₂ and Q ₃ maintain the previous states similarly to the operation mode (t ₂ to t ₃ ) only to be a state (N ₁₎ that does not occur in the amount of current change, and thus along the secondary winding of the transformer stage (TR) (N _2), the secondary side resonant current (I _T2) can no longer be induced.

Then, the sixth switching element current path formed through the antiparallel diode of the first diode (D ₇₎ of the (Q ₆₎ has been lost again, and only the current path formed through the secondary side auxiliary inductor (L _A2) remains. This resonant current induced in the secondary winding of the transformer stage (TR) (N ₂₎ is again determined by a secondary side excitation current (I _A2).

As described above, the bidirectional SLLC resonant converter of the present invention has a primary winding transformer leakage inductance ( _L11 ) and a secondary winding transformer leakage inductance ( _L12 ) during forward power transfer from the primary side low voltage end to the secondary side high voltage end. , The resonant capacitor C _s located on the secondary side, and the resonance characteristics of the secondary side auxiliary inductor L _A2 .

FIG. 12 is a waveform diagram for operating the bidirectional SLLC resonant converter of FIG. 9A in the reverse operation, and FIG. 13 is a diagram for explaining the reverse operation of the bidirectional SLLC resonant converter of FIG.

12, in the reverse operation of the bidirectional SLLC resonant converter, the fifth and sixth switching elements Q ₅ and Q ₆ are alternately switched to 50% duty and the first and second diodes D ₇ and D ₈ Side auxiliary switching elements S _A3 and S _A4 connected between the contact d of the secondary side first and second capacitors C _o1 and C _o2 and the contact e of the secondary side first and second capacitors C _o1 and C _o2 , (121) is switched to a half-wave resonance circuit.

Since the first to fourth switching elements Q ₁ , Q ₂ , Q _{3 and} Q ₄ are turned off and the primary side bidirectional auxiliary switching elements S _A1 and S _A2 are turned on, So that the current flows not only through the primary winding N1 but also through the primary auxiliary inductor L _A1 .

Hereinafter, the reverse operation of the bidirectional SLLC resonant converter of the present invention will be described below with reference to FIGS. 13A to 13D.

The fifth switching element Q ₅ is turned on to turn on the fifth switching element Q ₅ and the resonance capacitor C _S and the secondary winding N ₂ of the transformer TR in the operation mode t ₁ to t ₂ , And the secondary side auxiliary inductor L _A2 , the secondary side first capacitor C _o1 and the second capacitor C _o2 .

Then, the divided voltage [(1/2) V _o ] of the secondary side first and second capacitors C _o1 and C _o2 is applied to the resonance capacitor C _s connected in series with the secondary side of the transformer TR, Current is applied to the secondary side inductor L _A2 connected in parallel to the secondary side inductor L _{A2 and} is also applied to the secondary side inductor L _A2 . However, the auxiliary inductor current I _A2 ).

In the first and fourth switching elements (Q _1, Q ₄₎ the primary side resonance current flowing through the antiparallel diode of (I _T1) and a primary side auxiliary inductor connected to the primary side in parallel with the transformer (TR) (L _A1 And the primary-side excitation current I _A1 flowing through the primary-side bidirectional auxiliary switching elements S _A1 and S _A2 become the secondary-induced resonance current. At this time, the secondary side resonance current I _T2 is a sum current [I _T2 = (1 / n) (I _A1 + I _T1 ) + I _A2 / 2) of the resonance current induced in the secondary side and the secondary side auxiliary inductor current, is a _{n = (N 2 / N 1} )].

In the operation mode (t ₂ to t ₃ ), as the time for applying the secondary-side resonance current becomes longer, the amount of current does not change at the secondary winding N ₂ of the transformer TR, The further resonance current I _T1 is not induced in the primary winding N _{1 of the} transformer N1.

Then the first and fourth switching elements (Q _1, Q ₄₎ reverse current path formed through the parallel diode disappears, the primary auxiliary inductor (L _A1) and the primary side two-way auxiliary switching element (S _A1, S _A2) And the secondary side resonance current I _T2 is determined by the secondary side auxiliary inductor current.

In the operation mode (t ₄ to t ₅ ), the fifth switching element Q ₅ is turned off again, the sixth switching element Q ₆ is turned on, and the sixth switching element Q ₆ , the resonant capacitor C _s , the current path is formed via the secondary-side winding stage (N ₂₎ and the secondary-side auxiliary inductor (L _A2), the secondary-side second capacitor (C _o2) a first capacitor (C _o1) of the transformer (TR).

Resonance current flows through the resonance capacitor C _s and the secondary side auxiliary inductor L _A2 and the primary side resonance current flowing through the antiparallel diode of the second and third switching devices Q ₂ and Q ₃ I _T1) and a primary side auxiliary inductor connected to the primary side in parallel with the transformer (TR) (L _A1) and the primary side two-way auxiliary switching element (S _A1, the primary exciting current flowing through the S _A2) (I _A1) is Resulting in a resonance current induced in the secondary side.

As a result, the secondary-side resonance current I _T2 is the total sum of the resonance current induced in the secondary side and the secondary-side auxiliary inductor current [I _T2 = (1 / n) (I _A1 + I _T1 ) + I _A2 / 2 , n = is an _{(N 2 / N 1)]} .

In the mode of operation (t ₅ ~ t ₆₎ in accordance with the longer the time that is a secondary side resonance current, and not the secondary winding ends of the transformer (TR) (N ₂₎ is not a change in current occurs, the transformer (TR) The further resonance current I _T1 is not induced in the primary winding N _{1 of the} transformer N1.

In the first and fourth switching elements (Q _1, Q ₄₎ reverse current path formed through the parallel diode disappears, the primary auxiliary inductor (L _A1) and the primary side two-way auxiliary switching element (S _A1, S _A2) And the secondary side resonance current I _T2 is again determined by the secondary side auxiliary inductor current.

As described above, in the present invention, the leakage inductance L _{l2 of the} secondary side winding transformer and the leakage inductance L _{l1 of the} primary side winding transformer in the reverse power transfer operation from the high voltage end of the secondary side to the low voltage end of the primary side are located on the secondary side The LLC resonant characteristics are generated on the secondary side using the resonance characteristics with the resonant capacitor C _s and the primary side auxiliary inductor L _A1

In addition, the secondary-side first and second capacitors (C _o1, C _o2) a voltage divider of [(1/2) V _o] is the secondary side to be applied by the auxiliary inductor (L _A2), secondary-side auxiliary inductor (L _A2 The auxiliary inductor current I _A2 flowing through the secondary side auxiliary inductor L _A2 can be reduced to ½ so that the bidirectional switching elements S _A1 and S _A2 connected to the secondary side auxiliary inductor L _A2 need not be separately provided.

Figure 14 shows another embodiment of a bidirectional SLLC resonant converter according to the present invention.

The bidirectional SLLC resonant converter of Fig. 14 is similar to the bidirectional SLLC resonant converter of Fig. 14 except that instead of inserting the primary side auxiliary circuit portion 112 between both ends a and b of the first converter of Fig. 9a, an air- TR to reduce the primary magnetization inductance L _m1 and flow a large magnetizing current Im 1 thereby to have a high gain LLC resonance characteristic even in the transmission of reverse power.

15 to 18, in the forward power transfer operation, the secondary side bidirectional auxiliary switching devices S _A3 and S _A4 are turned off, and the secondary side resonance current I _T2 is turned off in the fifth and sixth Is rectified through the anti-parallel diodes of the switching elements (Q ₅ , Q ₆ ) and the first and second diodes (D ₇ , D ₈ ), and flows into the load.

9A, the secondary side bidirectional auxiliary switching devices S _A3 and S _A4 are turned on and the fifth and sixth switching devices Q ₅ and Q ₆ are turned on in the reverse power transfer operation, So that the secondary converter 121 can be operated as a half-wave resonance circuit by alternately switching to 50% duty. Then, the divided voltage [(1/2) V _o ] of the secondary side first and second capacitors C _o1 and C _o2 is applied to the resonance capacitor C _s connected in series with the secondary side of the transformer TR, current flows, on the other secondary-side in parallel with the auxiliary inductor (L _A2) at both ends to the secondary-side auxiliary inductor (L _A2) in the current is the secondary side auxiliary inductor reduced 1/2 in accordance with the voltage divider only flow _(A2 L) current (I _A2 ) flows.

And the resonance current induced in the primary side is converted into the resonance current I _T1 flowing through the antiparallel diode of the primary side switching devices Q ₁ , Q _2, Q _{3 and} Q ₄ and the transformer TR ) Due to the large primary magnetizing current (I _m1 ) flowing through the primary magnetizing inductance (L _m1 ) of the reduced transformer (TR) .

(At this time, the resonance current (I _T1 ) flowing through the antiparallel diode of the primary side switching devices (Q ₁ , Q _2, Q _3, Q ₄ ) at the primary side input terminal of the low voltage high current is very large, because when the current in the antiparallel diode of the primary side switching element _{(Q 1, Q 2, Q} 3, Q 4) to minimize the conduction loss to flow the primary switching elements _{(Q 1, Q 2, Q} 3, Q 4) And can operate as a synchronous rectifier that can minimize the conduction loss by lowering the conduction voltage)

Figures 19 and 21 show further embodiments of a bidirectional SLLC resonant converter according to the present invention.

The bidirectional SLLC resonant converter of Fig. 19 further includes first and second auxiliary inductors L _r1 and L _r2 respectively inserted into the first and second side ends 110 and 120 respectively, or a second auxiliary inductor L _A2 and a couple The inductor of the ringed auxiliary winding can be used to convert the gain so that the switching operating frequency is operated near the resonant frequency.

The first auxiliary inductor L _{r1 is} connected between the contact point a of the first and second switching elements Q1 and Q2 and the primary winding N ₁ of the transformer TR, L _r2 may be located between the contact c of the fifth and sixth switching elements Q ₅ and Q ₆ and the resonant capacitor C _s of the transformer TR.

Of course, the full-bridge bidirectional SLLC resonant converter of FIG. 14 may also be provided with additional auxiliary inductors L _r1 and L _r2 inserted into the primary side and the secondary side 210 and 220, respectively, as in the bidirectional SLLC resonant converter of FIG. , The gain can be converted so that the switching operating frequency is operated near the resonant frequency.

Although the bidirectional SLLC resonant converter of Figs. 19 to 21 has a difference in that the switching operation frequency is variable, the basic operation principle is the same as that of the full bridge bidirectional SLLC resonant converter of Figs. 9A and 14, The operation of the second embodiment is not described separately.

The full bridge bidirectional SLLC resonant converter of Figs. 9A and 14 includes first to fourth switching elements Q ₁ and Q ₂ (Q ₁ , Q ₂ ) constituting the primary side converter 111 of the primary side 110, , Q _3, Q ₄₎ by replacing a portion (Q _1, Q ₂₎ of the capacitor (C _1, C _2), it may be converted to a half bridge (Bridge Harf) bidirectional SLLC resonant converter.

Since the basic operation principle of such a half bridge bidirectional SLLC resonant converter is the same as that of the bidirectional SLLC resonant converter of Figs. 9A and 14, the operation of the bidirectional SLLC resonant converter of Figs. 14 and 15 is not described separately.

22 shows structural examples of a bidirectional auxiliary switching element part in a bi-directional SLLC resonant converter according to the present invention.

22, the bidirectional switching elements S _A1 , S _A2 , S _A3 , and S _A4 have opposite polarities and include two switches S _Aux1 connected in series, two switches S _aux1 having opposite polarities, The switch S _Aux2 and the mechanical contact terminal S _Aux3 may be implemented in various forms such as a power MOSFET, an IGBT, a power TR, an SCR, an SSR, a relay, a contact, .

Each of the first to sixth switching elements Q ₁ , Q ₂ , Q ₃ , Q ₄ , Q ₅ and Q ₆ may be implemented not only as a power MOSFET but also as a switching element such as an IGBT, a Power TR, or an SCR .

Although not shown, the first and eighth switching elements Q ₁ to Q ₄ , the first to eleventh to fourteenth switching elements Q ₁ to Q ₄ , the first to twenty _first to twenty-fourth switching elements S ₁ to S _4, S ₄ ), the secondary side fifteenth and sixteenth switching devices Q _{5 and} Q ₆ and the secondary side twenty-fifth and twenty-sixth switching devices S ₅ and S ₆ are implemented as one of a power MOSFET, an IGBT, a power TR, and an SCR It can be done.

Figures 23-25 illustrate waveforms observed in the forward and backward operation of the bidirectional SLLC resonant converter of Figure 9A.

This is achieved by applying an auxiliary switch and an inductor-applied bidirectional DC-DC converter having a rated output capacity of 1 kW to the bidirectional SLLC resonant converter of FIG. 9A to generate a constant secondary output (V _in : 41 V to 60 V) voltage (V _o: 400V), and an experimental result for the maximum rated capacity of 1kW, the reverse mode when the secondary side constant output voltage (V _o: 400V) 1 side control voltage range (41V~60V) and up to the rated capacity under the conditions 1kW The results are shown in Fig. The parameters of the bidirectional SLLC resonant converter are shown in Table 1.

Forward (as seen from the primary) / reverse (as seen from the secondary) Transformer parameters The primary side magnetic inductance (L _p ) 83.75uH Equivalent leakage inductance ( _Leq ) / ( _Leq ) 5.213 uH / 158.3 uH The secondary side magnetic inductance (L _s ) 2.582mH The primary side leakage inductance (L _l1 ) / (L _l1 / N ² ) 1.875uH / 55.476uH Secondary side leakage inductance (N ² L ₁₂ ) / (L ₁₂ ) 3.48 uH / 104.039 uH Magnetizing inductance _{(L m) / (L m} / N 2) 81.875uH / 2.478mH Turn ratio N (N ₁ / N ₂ ) 0.182 (6: 33) The primary side auxiliary inductor (L _A1 ) / (L _A2 ) 9.757uH / 385.2uH The resonance capacitor (C _r3 ) 44 nF

Fig. 23 is an experimental waveform for the bidirectional SLLC resonant converter of Fig. 9A. In the forward mode, the primary side input control voltage (V _in ) is 41V, 60V (V _ab , V _cd ) and current (I _T1 , I _T2 ) when the secondary side constant output voltage (V _o ) is 400 kV and 1 kW, respectively.

FIG. 24 is an experimental waveform for the bidirectional SLLC resonant converter of FIG. 9A. In the case of the primary side input control voltage (V _in ) of 41 V and 60 V at 1 kW when the secondary side constant output voltage (V _o ) Terminal voltages V _ab and V _cd , and currents I _T1 and I _T2 .

Referring to FIG. 25, the bidirectional SLLC resonant converter of FIG. 9A has a maximum efficiency of 94.53% at a primary side input control voltage (V _in ) of 60V, a secondary side constant output voltage and a load capacity of 400V / 1kW _{in the} forward mode, (V _o ) 400V at the primary side, and 89.2% at the primary input control voltage and load capacity of 41V / 1kW. That is, it exhibits high efficiency characteristics.

Figures 26 and 27 show waveforms observed in the forward and backward operation of the bidirectional SLLC resonant converter of Figure 14 and in experimental results.

The bidirectional SLLC resonant converter of FIG. 14 includes an auxiliary inductor L _A1 and a bi-directional switching device S _A1 , S _{A2 in} parallel with the primary T _{1 of the} transformer T ₁ as shown in FIG. 9A to obtain a high voltage gain characteristic in a reverse power transfer operation. A large primary magnetizing current I (I) flowing through the primary side magnetizing inductance L _m1 , which is reduced by placing an air-gap in the transformer T ₁ instead of using the auxiliary means 1 constituted by the transformer T ₁ , _lt ; _{RTI ID} = 0.0 &_gt; _m1 ) &_lt; / _RTI >

In this embodiment, 1kW were experiments to produce a SLLC two-way DC / DC converter has a rated output capacity, 26 is the input voltage is 41V _DC, constant output terminal an output voltage from 60V _DC 400V control the output capacity of the forward when at the 1kW conditions FIG. 27 is an experimental waveform when the input voltage is 400 V _{DC and the} output voltage is 950 W when the input voltage is constantly controlled at 41 V _DC and 60 V _DC , and the same experimental result as that of the conventional LLC resonant converter is obtained I could.

The efficiency characteristics in the forward power transfer operation are as low as 89% ~ 91.1% due to the large magnetizing current (I _m1 ) and the current (I _A2 ) flowing in the secondary ancillary inductor according to the application of the transformer having a large gap, The efficiency characteristic in the transfer operation is that 90% ~ 92.14% efficiency is obtained because the voltage applied to the secondary side auxiliary inductor (L _A2 ) is less than that of the forward power transfer operation when 1/2 of the output voltage (V _o ) I have. That is, it can be seen that the bidirectional SLLC resonant converter of FIG. 14 has the same high efficiency characteristics as the bidirectional SLLC resonant converter of FIG. 9A.

The method according to the present invention can be implemented as a computer-readable code on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and a carrier wave (for example, transmission via the Internet). The computer-readable recording medium may also be distributed over a networked computer system so that computer readable code can be stored and executed in a distributed manner.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (22)

delete A first to a third synchronous rectifier which is connected in parallel to the primary side input voltage and which operates as a synchronous rectifier which is switched by a full bridge converter in the forward operation and is turned off in synchronism with the current flowing through the anti- A primary side converter having four switching elements; A primary side auxiliary circuit part connected between both ends of the primary side converter and connected in parallel to the primary side auxiliary inductor at both ends of the primary side converter in a reverse direction operation; And a switch connected between both ends of the primary side converter for inducing a current change through the first winding end of the transformer during forward operation and guided through a first winding end of the transformer and the primary side auxiliary inductor during reverse operation A primary side end having a primary resonance part for charging the primary side input voltage according to a change in current; And
A secondary side first and second capacitors connected in parallel with the secondary side output voltage; A secondary side converter connected in parallel to the secondary side first and second capacitors and having fifth and sixth switching elements connected in a full bridge structure and first and second diodes; And the secondary side converter is switched to the half-wave resonance circuit by connecting the contacts of the first and second diodes to the contacts of the secondary side first and second capacitors in the reverse direction operation, A secondary side bidirectional auxiliary switching unit for releasing the connection between the contact of the first diode and the second diode and the contact of the secondary side first and second capacitors so that the secondary side converter operates as a full wave rectification circuit; A secondary side auxiliary inductor connected in parallel between both ends of the secondary side converter; And a rectifier circuit connected in parallel between both ends of the secondary side converter for charging the secondary side output voltage in accordance with a change in current induced through a second winding end of the transformer and a secondary side inductor during a forward operation, An auxiliary switch including a secondary side end having a secondary winding end of the transformer and a secondary side resonance part for inducing a current change through the secondary side auxiliary inductor, and an SLLC resonance converter for inductor application bidirectional power reception.
3. The resonator of claim 2, wherein the primary resonator comprises:
And a first winding end of the transformer connected between both ends of the primary side converter. The auxiliary switch and the inductor apply SLLC resonance converter for bidirectional power transfer.
3. The apparatus according to claim 2, wherein the primary side auxiliary circuit portion
And a primary side auxiliary inductor and a primary side bi-directional auxiliary switching device connected in parallel with the primary resonance part between both ends of the primary side converter. The auxiliary switch and the inductor-applied SLLC resonance converter for bi- .
5. The switching device according to claim 4, wherein the primary side bidirectional auxiliary switching device
Wherein the at least one of the two switching elements has a polarity opposite to that of the at least one switching element, the at least one of the two switching elements having opposite polarities, the two switching elements having opposite polarities, and the mechanical contact terminal. .
A first to a third synchronous rectifier which is connected in parallel to the primary side input voltage and which operates as a synchronous rectifier which is switched by a full bridge converter in the forward operation and is turned off in synchronism with the current flowing through the anti- A primary side converter having four switching elements; A primary side auxiliary circuit part having a primary side auxiliary inductor connected between both ends of the primary side converter; And a switch connected between both ends of the primary side converter for inducing a change in current through the primary side of the primary side auxiliary inductor and the transformer during a forward operation and forwarding a current change through the primary side of the transformer, A primary side end having a primary resonance part for charging the primary side input voltage according to a change in current induced through the auxiliary inductor; And
A secondary side first and second capacitors connected in parallel with the secondary side output voltage; A secondary side converter connected in parallel to the secondary side first and second capacitors and having fifth and sixth switching elements connected in a full bridge structure and first and second diodes; And the secondary side converter is switched to the half-wave resonance circuit by connecting the contacts of the first and second diodes to the contacts of the secondary side first and second capacitors in the reverse direction operation, A secondary side bidirectional auxiliary switching unit for releasing the connection between the contact of the first diode and the second diode and the contact of the secondary side first and second capacitors so that the secondary side converter operates as a full wave rectification circuit; A secondary side auxiliary inductor connected in parallel between both ends of the secondary side converter; And a rectifier circuit connected in parallel between both ends of the secondary side converter for charging the secondary side output voltage in accordance with a change in current induced through a second winding end of the transformer and a secondary side inductor during a forward operation, An auxiliary switch including a secondary side end having a secondary winding end of the transformer and a secondary side resonance part for inducing a current change through the secondary side auxiliary inductor, and an SLLC resonance converter for inductor application bidirectional power reception.
A first to a third synchronous rectifier which is connected in parallel to the primary side input voltage and which operates as a synchronous rectifier which is switched by a full bridge converter in the forward operation and is turned off in synchronism with the current flowing through the anti- A primary side converter having four switching elements; A primary side auxiliary circuit part having a primary side auxiliary inductor connected between both ends of the primary side converter; Wherein the primary side auxiliary transformer is connected between both ends of the primary side converter and induces a current change through the primary side of the primary side auxiliary inductor and the transformer during forward operation, A primary resonance unit for charging the primary side input voltage according to a change in current induced through the inductor; And a first auxiliary inductor connected between a contact of the first and second switching elements and a leakage inductance of a first winding end of the transformer; And
A secondary side first and second capacitors connected in parallel with the secondary side output voltage; A secondary side converter connected in parallel to the secondary side first and second capacitors and having fifth and sixth switching elements connected in a full bridge structure and first and second diodes; And the secondary side converter is switched to the half-wave resonance circuit by connecting the contacts of the first and second diodes to the contacts of the secondary side first and second capacitors in the reverse direction operation, A secondary side bidirectional auxiliary switching unit for releasing the connection between the contact of the first diode and the second diode and the contact of the secondary side first and second capacitors so that the secondary side converter operates as a full wave rectification circuit; A secondary side auxiliary inductor connected in parallel between both ends of the secondary side converter; And a rectifier circuit connected in parallel between both ends of the secondary side converter for charging the secondary side output voltage in accordance with a change in current induced through a second winding end of the transformer and a secondary side inductor during a forward operation, An auxiliary switch including a secondary side end having a secondary winding end of the transformer and a secondary side resonance part for inducing a current change through the secondary side auxiliary inductor, and an SLLC resonance converter for inductor application bidirectional power reception.
delete The secondary-side converter according to any one of claims 2, 6, and 7, wherein the secondary-
Fifth and sixth switching elements connected in parallel to the secondary side first and second capacitors; And
And a first and a second diode connected in parallel to the fifth and sixth switching elements. The auxiliary switch and the inductor apply SLLC resonant converter for bidirectional power transfer.
10. The resonator of claim 9, wherein the secondary resonator comprises:
A resonance capacitor connected to the contacts of the fifth and sixth switching elements; And
And a secondary side winding end of the transformer connected between the resonant capacitor and the contacts of the first and second diodes. 2. The SLLC resonant converter for bidirectional power transfer according to claim 1,
8. A method according to any one of claims 2, 6, and 7,
Further comprising a second auxiliary inductor located between the contacts of the fifth and sixth switching elements and a secondary winding end of the transformer or an inductor of an auxiliary winding coupled to the secondary auxiliary inductor. SLLC resonant converter for bidirectional power transfer.
The apparatus as claimed in any one of claims 2, 6, and 7, wherein the secondary side bidirectional auxiliary switching unit
Wherein the secondary side bidirectional auxiliary switching unit is connected between the contacts of the first and second diodes and the contacts of the secondary side first and second capacitors and the secondary side bidirectional auxiliary switching unit comprises two switching elements having opposite polarity and connected in series, And a bidirectional auxiliary switching element implemented with at least one of two switching elements having a first terminal and a second terminal connected in parallel, and a mechanical contact terminal. The auxiliary switch and the inductor-applied SLLC resonant converter for bidirectional power transfer.
delete A first to a third synchronous rectifier which is connected in parallel to the primary side input voltage and which operates as a synchronous rectifier which is switched by a full bridge converter in the forward operation and is turned off in synchronism with the current flowing through the anti- A primary side converter having four switching elements; And a switch circuit coupled between both ends of the primary side converter for inducing a current change through the first winding stage and the magnetizing inductance of the transformer during forward operation and a current induced through the first winding stage and magnetizing inductance of the transformer during reverse operation, A primary side having a primary resonance part for charging the primary side input voltage according to a change; And
A secondary side first and second capacitors connected in parallel with the secondary side output voltage; A secondary side converter connected in parallel to the secondary side first and second capacitors and having fifth and sixth switching elements connected in a full bridge structure and first and second diodes; And the secondary side converter is switched to the half-wave resonance circuit by connecting the contacts of the first and second diodes to the contacts of the secondary side first and second capacitors in the reverse direction operation, A secondary side bidirectional auxiliary switching unit for releasing the connection between the contact of the first diode and the second diode and the contact of the secondary side first and second capacitors so that the secondary side converter operates as a full wave rectification circuit; A secondary side auxiliary inductor connected in parallel between both ends of the secondary side converter; And a rectifier circuit connected in parallel between both ends of the secondary side converter for charging the secondary side output voltage in accordance with a change in current induced through a second winding end of the transformer and a secondary side inductor during a forward operation, And a secondary side end having a secondary winding end of the transformer and a secondary side resonance part for inducing a current change through the secondary side auxiliary inductor,
Wherein the transformer has a gap for reducing the magnetizing inductance. The auxiliary switch and the inductor apply the SLLC resonant converter for bi-directional power transfer.
15. The apparatus of claim 14, wherein the primary side
And a first auxiliary inductor connected between a contact of the first and second switching elements and a leakage inductance of a first winding end of the transformer. The auxiliary switch and the inductor apply SLLC resonance for bi- Converter.
15. The apparatus of claim 14, wherein the primary side
First and second switching elements connected in parallel to the primary side input voltage and first and second capacitors connected in parallel to the first and second switching elements, wherein the first and second switching elements A primary-side converter operating as a hub bridge converter; And
Wherein the transformer is connected between both ends of the primary side converter and induces a current change through a first winding stage and a magnetizing inductance of the transformer during forward operation and a current induced through the first winding stage and magnetization inductance of the transformer during reverse operation, And a primary side resonance unit for charging the primary side input voltage in accordance with the change of the primary side resonance frequency. The auxiliary switch and the inductor-applied SLLC resonance converter for bi-directional power transmission.
17. The resonator according to any one of claims 14 to 16, wherein the primary resonance portion
And a first winding end of the transformer connected between both ends of the primary side converter. The auxiliary switch and the inductor apply SLLC resonance converter for bidirectional power transfer.
delete 15. The system of claim 14, wherein the secondary side converter
Fifth and sixth switching elements connected in parallel to the secondary side first and second capacitors; And
And a first and a second diode connected in parallel to the fifth and sixth switching elements. The auxiliary switch and the inductor apply SLLC resonant converter for bidirectional power transfer.
15. The apparatus of claim 14, wherein the secondary resonator comprises:
A resonance capacitor connected to the contacts of the fifth and sixth switching elements; And
And a secondary side winding end of the transformer connected between the resonant capacitor and the contacts of the first and second diodes. 2. The SLLC resonant converter for bidirectional power transfer according to claim 1,
15. The apparatus of claim 14, wherein the secondary side bidirectional auxiliary switching unit
A bidirectional auxiliary switching element having at least one of two switching elements having opposite polarities and connected in series, two switching elements having opposite polarities and parallel connection, and a mechanical contact terminal. SLLC resonant converter for power transfer.
15. The apparatus of claim 14, wherein the secondary side
Further comprising a second auxiliary inductor located between the contacts of the fifth and sixth switching elements and a secondary winding end of the transformer or an inductor of an auxiliary winding coupled to the secondary auxiliary inductor. SLLC resonant converter for bidirectional power transfer.

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