KR101333285B1 - Sllc resonant converter for bidirectional power conversion - Google Patents

Abstract

An SSL resonant converter for bidirectional power conversion is disclosed. The present invention comprises; a primary side end which is connected to a first direct current power source and induces the current change of a first wiring end of first and second resonant transformers in the operation of a forward direction operation and connects primary side first and second sub inductors to the first wiring end of the first and second resonant transformers in the operation of a reverse direction and makes the current change induced to the first wiring end of the first and second resonant transformers have an LLC resonant characteristic by the current change of a second wiring end of the first and second resonant transformers and charges the first direct current power source; and a secondary side end which is connected to a second direct current power source and induces the current change of the second wiring end of the first and second resonant transformers in the operation of a reverse direction ad connects secondary side first and second sub inductors to the second wiring end of the first and second resonant transformers and first and second capacitors and makes the current change induced to the second wiring end of the first and second resonant transformers have the LLC resonant characteristic by the current change of the first wiring end of the first and second resonant transformers and charges the second direct current power source.

Description

SLLC Resonant Converter for Bidirectional Power Conversion}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional power transferable DC-DC converter, and more particularly, to a bidirectional power transferable DC-DC converter that steps up from a low input voltage, a high current to a high voltage, and steps down from a high voltage to a low voltage.

Insulation type bidirectional DC / DC converters such as photovoltaic power system-related power control systems (PCS) and electric vehicles are being widely used as converters for energy storage systems. Since the energy storage system conversion system requires high efficiency and safety, there is a bi-directional power-receivable DC / DC converter using an insulated high-frequency transformer and a bidirectional power-capable DC / DC converter incorporating a voltage source converter or a current source converter Has been developed.

Recently, bi-directional power-supply DC / DC converters with soft switching LLC resonant converters have been applied to reduce size, switching losses, and electro-magnetic interference (EMI).

1 shows an example of a conventional bidirectional DC / DC converter.

The bidirectional DC / DC converter of FIG. 1 is implemented as a kind of LLC resonant converter, and the LLC resonant converter is capable of zero voltage switching (ZVS) and zero current switching (ZCS) operation. In addition, the step-down / step-down control is possible based on the standardized resonant frequency point (f _s / f _r = f _n = 1). Power control is possible.

However, in order to enable bidirectional power transfer, the bidirectional DC / DC converter of FIG. 2 applies resonant capacitors C _r1 , C _r2 (or C _B1 ) to the primary and secondary sides of the LLC resonant converter. Depending on the capacitance value of the secondary resonant capacitor, it has a different operating characteristic from that of the conventional LLC resonant converter gain.

2 to 4 show resonance characteristics of the bidirectional DC / DC converter of FIG. 1.

In the case of the forward or reverse power cane resonant capacitor to the bi-directional power cane possible LLC resonant converter the primary side and the secondary side (C _r1, C _r2) is, and the secondary-side resonant capacitor in comparison to the primary side is applied a resonance capacitor (C _r1) (C _r2 ) Has a large capacitance (C _B1 ) as a blocking capacitor, so the voltage variation of the secondary resonance capacitor is not large, and as seen from the input side, it appears as in the conventional LLC resonant converter gain characteristics as shown in FIG. 2.

However, when a small resonance capacitance (C _r2 ) is applied to the secondary resonance capacitor, the voltage variation of the secondary resonance capacitor (C _r2 ) increases, and is operated in conjunction with the primary resonance capacitor (C _r1 ). As shown, gain characteristics in which CCL resonance characteristics and LLC resonance characteristics are mixed appear, and in the region below the resonance frequency and in the case of heavy load, the slope of the gain is inclined to a slope having a value smaller than the gain at the resonance frequency point. Unlike the characteristics, it is easily operated in the hard switching area. In order to have the gain slope characteristic upward so that the gain slope due to the load fluctuation has a larger value than the gain at the resonance frequency point, the magnetization inductance L _m1 of the applied transformer is greatly reduced to obtain the gain characteristic at low input voltage or heavy load conditions. There is a need to improve the slope. However, a very large magnetization current (I _m1 ) flows according to the very reduced magnetization inductance (L _m1 ), so that a conduction loss is greatly increased in switching devices and applied parts.

5 and 6 show another example of a conventional bidirectional DC / DC converter.

The bidirectional DC / DC converters of FIGS. 5 and 6 are bi-directional DC / DC converters proposed to improve the problems of the bidirectional DC / DC converters of FIG. Bi-directional DC-DC converter, Applicant: Jeonju University) and Korean patent application (Patent Application No.:10-2012-0043433, Name: Bi-directional DC-DC converter, Applicant: Jeonju University, Kakonew Energy).

The bidirectional DC / DC converters of FIGS. 5 and 6 include bidirectional auxiliary switches S _A1 , S _A2 , S _A3 and S _A4 , blocking capacitors C _B1 , C _B2 , C _B3 , and C _B4 and auxiliary switches S _R1. We have proposed a resonant converter capable of two-way power transmission with auxiliary means consisting of, S _R2 , S _R3 , S _R4 ) and diodes (D _R1 , D _R2 , D _R3 , D _R4 ). However, the bidirectional DC / DC converter of FIG. 5 has a disadvantage in that the circuit components are complicated because the main switch and the blocking capacitor are applied to all main circuits, and the conduction loss increases because the resonant current flows through the auxiliary switch. In addition, since the bi-directional DC / DC converter of FIG. 6 adopts a full-bridging (FB) resonant converter method, it is possible to apply a switching element having a lower current rating than a half-bridging (HB) resonant converter method for the same output capacitance. It is easy to reduce the loss and expand it to medium and large capacity, but in the bi-directional power converter that boosts to high output voltage at low input voltage and high current, and reverses to low voltage and high current at high output voltage, The primary resonance capacitor has to bear a large resonance current, so a primary resonance capacitor with a large current resistance is used.In particular, when a large current resonance current flows over several tens of amperes, it is difficult to handle with one resonance capacitor. Since it must be increased in size, there is a disadvantage such as a unit price increase.

SUMMARY OF THE INVENTION An object of the present invention is to provide a SLLC resonant converter for bidirectional power transmission, which can simplify the circuit configuration and improve efficiency.

SLLC resonant converter according to an embodiment of the present invention for achieving the above object is connected to the first DC power source, induces a current change in the first winding end of each of the first and second resonant transformer in the forward operation, In the reverse operation, the first and second auxiliary inductors are connected to the first winding ends of the first and second resonant transformers, respectively, so that the first current is changed by the current change of the second winding ends of the first and second resonant transformers. And a primary side stage configured to charge the first DC power supply so that a current change induced in each of the first winding ends of the second resonant transformer has an LLC resonance characteristic. And a second DC power supply having a higher voltage level than the first DC power supply, inducing a current change in a second winding end of each of the first and second resonant transformers in a reverse operation, and a secondary side in a forward operation. The first and second auxiliary inductors are connected to the second winding ends of the first and second resonant transformers and the first and second resonant capacitors, respectively, to change the current of the first winding ends of the first and second resonant transformers. And a secondary side end configured to charge the second DC power supply so that a current change induced in each of the second winding ends of the first and second resonant transformers has an LLC resonance characteristic.

SLLC resonant converter according to another embodiment of the present invention for achieving the above object is connected to the first DC power source, induces a current change in the first winding end of the resonant transformer in the forward operation, the primary side in the reverse operation The auxiliary direct inductor is connected to the first winding end of the resonant transformer so that the current change induced in the first winding end of the resonant transformer by the current change of the second winding end of the resonant transformer has the LLC resonant characteristic, thereby providing the first DC power supply. Primary side charging; And a second DC power supply having a higher voltage level than the first DC power supply, inducing a current change in the second winding end of each of the resonant transformers in a reverse operation, and resonating the secondary auxiliary inductor in a forward operation. The second DC power supply is connected to the second winding end of the transformer and the resonant capacitor so that the current change induced in each of the second winding ends of the resonant transformer by the current change of the first winding end of the resonant transformer has an LLC resonance characteristic. It includes; secondary side charging.

Accordingly, the SLLC resonant converter for bidirectional power transfer of the present invention does not use a large current resonant capacitor at a low voltage stage, applies a resonant capacitor at a high voltage stage, and uses a resonant characteristic with a separate auxiliary inductor. Since the circuit configuration is simple, the size can be reduced, the manufacturing cost can be reduced, and the efficiency can be improved.

1 shows an example of a conventional bidirectional DC / DC converter.
2 to 4 show resonance characteristics of the bidirectional DC / DC converter of FIG. 1.
5 and 6 show another example of a conventional bidirectional DC / DC converter.
Figure 7 shows one embodiment of a bidirectional SLLC resonant converter in accordance with the present invention.
FIG. 8 is an operational waveform diagram in a forward operation of the bidirectional SLLC resonant converter of FIG.
9 and 10 are diagrams for explaining the forward operation of the bidirectional SLLC resonant converter of FIG.
FIG. 11 is an operational waveform diagram in a reverse operation of the bidirectional SLLC resonant converter of FIG.
12 and 13 are diagrams for explaining reverse operation of the bidirectional SLLC resonant converter of FIG.
14 and 15 show another embodiment of a bidirectional SLLC resonant converter according to the present invention.
16 shows resonance characteristics of a bidirectional SLLC resonant converter according to the present invention.
17 shows an application example of a bidirectional SLLC resonant converter according to the present invention.
Figure 18 shows another embodiment of a bidirectional SLLC resonant converter in accordance with the present invention.
FIG. 19 shows an equivalent circuit of the primary end in the forward operation of the bidirectional SLLC resonant converter of FIG.
20 is an operational waveform diagram in a forward operation of the bidirectional SLLC resonant converter of FIG.
21 and 22 are diagrams for explaining, in sections, the forward operation of the bidirectional SLLC resonant converter of FIG.
FIG. 23 shows an equivalent circuit of the secondary side stage in the reverse operation of the bidirectional SLLC resonant converter of FIG.
24 is an operational waveform diagram in the reverse operation of the bidirectional SLLC resonant converter of FIG.
25 and 26 are diagrams for explaining reverse operation of the bidirectional SLLC resonant converter of FIG.
27 shows another configuration of the bidirectional auxiliary switching element section in the bidirectional SLLC resonant converter according to the present invention.
28 and 29 show waveforms observed in the experimental results during the forward operation and the reverse operation of the bidirectional SLLC resonant converter according to the present invention, respectively.
30 shows efficiency characteristics for the primary input voltage range in the forward operation of the bidirectional SLLC resonant converter according to the present invention.
Figure 31 shows the efficiency characteristics for the control range of the primary input voltage in the reverse operation of the bidirectional SLLC resonant converter according to the present invention.

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 7 shows one embodiment of a bidirectional SLLC resonant converter in accordance with the present invention.

The bidirectional SLLC (Secondary Inductor (L) Inductor (L) Capacitor) resonant converter of FIG. 7 is a full bridge bidirectional SLLC resonant converter, and includes a first DC power supply (V _in ) and a second DC power supply ( V _o ) and the resonant converter unit 100 having the primary side and secondary side ends 110 and 120. Here, the first DC power supply V _in has a lower voltage level than the second DC power supply V _o .

The primary end 110 of the resonant converter unit 100 may include a first capacitor connected in parallel with the first DC power supply V _in between the primary side first node Nd11 and the primary side second node Nd12 ( C _in ), the primary first switching element portion and the primary second switching element portion connected in parallel with the first capacitor C _in between the primary side first node Nd11 and the primary side second node Nd12. 1 between the primary side switching unit and the primary side resonating unit connected between the primary side first switching element unit and the primary side second switching element unit and between the primary side first switching element unit and the primary side second switching element unit. And a primary side auxiliary circuit portion connected in parallel with the secondary side resonance portion.

The first capacitor C _in is connected in series between the primary side first node Nd11 and the primary side second node Nd12 to stabilize the first DC power supply V _in . The first capacitor C _in may be removed in some cases.

The primary side first switching element unit includes first and second switching elements Q ₁ and Q ₂ connected in series between the primary side first node Nd11 and the primary side second node Nd12, and the primary side The second switching element unit includes third and fourth switching elements Q ₃ and Q ₄ connected in series between the primary side first node Nd11 and the primary side second node Nd12.

The primary side resonator includes a primary side third node Nd13 between the first and second switching elements Q ₁ and Q ₂ and a primary side fourth node between the third and fourth switching elements Q ₃ and Q ₄ . It is arranged between Nd14. The primary resonator includes a primary winding end N ₁ of the resonant transformer TR between the primary third node Nd13 and the primary fourth node Nd14. In FIG. 7, L ₁₁ represents the leakage inductance of the primary winding end N ₁ .

The primary side auxiliary circuit is connected between the primary side third node Nd13 and the primary side fourth node Nd14 in parallel with the primary side resonator, and the primary side third node Nd13 and the primary side fourth node Nd14. Primary side inductor (L _A1 ) and the primary side bi-directional auxiliary switching element portion connected in series. The primary bidirectional auxiliary switching device unit includes first and second auxiliary switching devices S _A1 and S _A2 connected in parallel to each other. Therefore, the primary side auxiliary inductor L _A1 is connected in parallel with the primary side resonator according to the turn-on / off operations of the first and second auxiliary switching elements S _A1 and S _A2 .

On the other hand, the secondary end 120 of the resonant converter unit 100 is a second capacitor connected in parallel with the second DC power supply (V _o ) between the secondary side first node (Nd21) and the secondary side second node (Nd22) (C _o ), the secondary side first switching element portion and the secondary side second switching element connected in parallel with the second capacitor (C _o ) between the secondary side first node (Nd21) and the secondary side second node (Nd22) Between the secondary side switching portion having a secondary portion, the secondary side resonating portion connected between the secondary side first switching element portion and the secondary side second switching element portion, and between the secondary side first switching element portion and the secondary side second switching element portion. And a secondary side auxiliary circuit portion connected in parallel with the secondary side resonance portion.

Similar to the first capacitor C _in , the second capacitor C _o is connected in series between the second side first node Nd21 and the second side second node Nd22 to supply a second DC power source V _o . Stabilize. Similarly to the first capacitor C _in , the second capacitor _CO may also be removed.

The secondary side first switching element unit includes fifth and sixth switching elements Q ₅ and Q ₆ connected in series between the secondary side first node Nd21 and the secondary side second node Nd22, and the secondary side. The second switching element unit includes seventh and eighth switching elements Q ₇ and Q ₈ connected in series between the secondary side first node Nd21 and the secondary side second node Nd22.

The secondary side resonator includes the secondary side third node Nd23 between the fifth and sixth switching elements Q ₅ and Q ₆ and the secondary side fourth node between the seventh and eighth switching elements Q ₇ and Q ₈ . It is arranged between Nd24. The secondary resonator includes a resonant capacitor C _s and a secondary winding end N ₂ of the resonant transformer TR between the secondary third node Nd23 and the secondary fourth node Nd24. That is, unlike the primary side resonator, the secondary resonator includes a resonant capacitor C _s . And L ₁₂ represents the leakage inductance of the secondary winding end N ₂ . The ratio n of the first and secondary winding ends N ₁ and N ₂ of the resonant transformer TR is N ₂ / N ₁ .

The secondary side auxiliary circuit part is connected between the secondary side third node Nd23 and the secondary side fourth node Nd24 in parallel with the secondary side resonator and the secondary side third node Nd23 and the secondary side fourth node Nd24. The secondary side inductor (L _A2 ) and the secondary side bi-directional auxiliary switching element portion connected in series. The secondary bidirectional auxiliary switching device unit includes third and fourth auxiliary switching devices S _A3 and S _A4 connected in parallel to each other. Therefore, the secondary side inductor L _A1 is connected in parallel with the secondary side resonator according to the turn-on / off operations of the third and fourth auxiliary switching elements S _A3 and S _A4 .

FIG. 8 is an operation waveform diagram of a bidirectional SLLC resonant converter of FIG. 7 in a forward operation, and FIGS. 9 and 10 are diagrams for explaining a forward operation of the bidirectional SLLC resonant converter of FIG.

8 to 10, the forward operation of the bidirectional SLLC resonant converter of FIG. 7 is described. Referring to FIG. 8, the forward operation of the bidirectional SLLC resonant converter of FIG. 8 includes six time intervals (t ₀ to 6 th time interval). t ₁ ), (t ₁ to t ₂ ), (t ₂ to t ₃ ), (t ₃ to t ₄ ), (t ₄ to t ₅ ), and (t ₅ to t ₆ )).

In FIG. 8, the voltage V _ab indicates the voltage level between the primary third node Nd13 and the primary fourth node Nd14.

In the forward operation, switching in which the first and fourth switching elements Q ₁ and Q ₄ and the second and third switching elements Q ₂ and Q ₃ of the primary end 110 are applied corresponding to the respective gates. It is alternately turned on / off in response to the voltage levels of the signals V _GQ1 to V _GQ4 . The first to fourth switching elements Q ₁ to Q ₄ have alternating switching signals V _GQ1 and V _GQ4 and switching signals V _{GQ2 and} V respectively having a fixed duty ratio (for example, 50%). _GQ3 ) is turned on and off in response. However, the fifth to eighth switching elements Q ₅ to Q ₈ of the secondary side end 120 remain off in the forward operation. Therefore, the fifth to eighth switching elements Q ₅ to Q ₈ of the secondary side end 120 operate as rectifier diodes as antiparallel diodes. In the forward operation, the first and second auxiliary switching elements S _A1 and S _A2 of the primary side end 110 are always turned off, and the third and third portions of the secondary side end 120 are turned off. 4 The auxiliary switching elements S _A3 and S _A4 are always turned on. In the forward operation, since the first and second auxiliary switching elements S _A1 and S _A2 of the primary end 110 are all turned off to have the LLC resonance gain characteristic having the high gain characteristic, The primary auxiliary inductor L _A1 of the primary end is not connected to the primary third and fourth nodes Nd13 and Nd14, so that the primary resonator is not connected to the primary auxiliary inductor L _A1 . Instead, since the third and fourth auxiliary switching elements S _A3 and S _A4 at the secondary end are always turned on, the secondary side inductor L _A2 is connected to the secondary resonator.

Referring to the operation in the first time interval t ₀ to t ₁ during the forward operation, the first and fourth switching elements Q ₁ and Q ₄ are turned on in response to the switching signals V _GQ1 and V _GQ4 . The off state is maintained in the previous state, and the second and third switching elements Q ₂ and Q ₃ are turned off in response to the switching signals V _GQ2 and V _GQ3 . Since all of the first to fourth switching elements Q ₁ to Q ₄ are turned off, no current path is basically generated.

However, the primary winding terminal of the resonant transformer (TR) (N ₁₎ the primary side resonance current (I _T1) change occurs and, the primary side resonance current (I _T1) by the first and fourth switching elements (S _1, A current path is formed and flows through the antiparallel diode of S ₄ ).

As a result, a resonant current is induced in the secondary winding end N ₂ of the resonant transformer TR. Among the resonant currents induced in the secondary winding end N ₂ , the secondary resonant current I _T2 has all of the fifth to eighth switching elements Q ₅ to Q ₈ turned off, but the secondary side resonant current ( I _T2 ) has a current path formed through the anti-parallel diodes of the fifth and eighth switching elements S _{5 and} S ₈ to flow to the second DC power source _Vo . In addition, since the third and fourth auxiliary switching elements S _A3 and S _A4 are turned on in the secondary side exciting current I _A2 among the resonance currents induced in the secondary winding end N ₂ , the secondary side inductor It flows to L _A2 . That is, the resonance current induced by the secondary winding end N ₂ by the primary resonance current I _T1 is the sum of the secondary resonance current I _T2 and the secondary excitation current I _A2 , as shown in Equation 1 below. appear.

Where n is the winding ratio (n = N ₂ / N ₁ ) of the resonant transformer TR.

Referring to the operation in the second time interval t ₁ to t ₂ , the first and fourth switching elements Q ₁ conducted to the anti-parallel diode (body diode) during the first time interval t ₀ to t ₁ . _, Q ₄ ) is turned on in response to the switching signals V _GQ1 and V _GQ4 in the second time interval t ₁ to t ₂ , and the second and third switching elements Q ₂ and Q _{3 are turned on.} ) Is turned off in response to the switching signals V _GQ2 and V _GQ3 . While the second and third switching elements Q ₂ and Q ₃ and the first and second auxiliary switching elements S _A1 and S _A2 maintain a turn-off state, the first and fourth switching elements Q _{1 ,} Q ₄ is turned on, so that a current path is still formed through the first and fourth switching elements Q _{1 and} Q ₄ and the primary side resonator. However, in the second time interval t ₁ to t ₂ , the first and fourth switching elements Q _{1 and} Q ₄ operate as switches other than the antiparallel diode of the first time interval t ₀ to t ₁ . .

In the second time interval t ₁ to t ₂ , the secondary side terminal 120 includes fifth to eighth switching elements Q ₅ to Q ₈ , and third and fourth auxiliary switching elements S _A3 and S _A4 . and the forming the same current path as the first time interval (t ₀ ~ t ₁₎ and the first time interval according to maintain the same state (t ₀ ~ t _1). Therefore, according to Equation 1, a resonance current is generated at the secondary end.

In the third time period t ₂ to t ₃ , the first and fourth switching elements Q _{1 and} Q ₄ maintain a turn-on state in response to the switching signals V _GQ1 and V _GQ4 . And the third switching elements Q ₂ and Q ₃ remain turned off in response to the switching signals V _GQ2 and V _GQ3 . That is, the states of the first to fourth switching elements Q ₁ to Q ₄ are the same as the second time intervals t ₁ to t ₂ . However, as the time for which the first DC power supply V _in is applied increases, the primary side resonance current I _T1 and the primary side resonance flowing between the primary third node Nd13 and the primary fourth node Nd14 are increased. The value nI _A2 obtained by multiplying the winding ratio by the secondary side exciting current I _A2 induced by the current I _T1 and flowing through the secondary side inductor L _{A2 of the} secondary side 120 is equal. This means that the secondary resonant current I _T2 becomes 0 according to Equation 1. Therefore, no change in the amount of current occurs in the primary winding end N ₁ of the resonance transformer TR, and the secondary resonance current I _T2 is induced in the secondary winding end N ₂ of the resonance transformer TR. Not shown. Although the second power supply voltage V _o is connected to the secondary side terminal 120 of the resonant converter unit 100, the fifth to eighth switching elements Q ₅ to Q ₈ are all turned off so that the current No path is formed. Accordingly, the secondary side resonance current I _T2 does not flow.

In the fourth time interval t ₃ to t ₄ , the first and fourth switching elements Q ₁ and Q ₄ are turned off in response to the switching signals V _GQ1 and V _GQ4 , and the second and third The switching elements Q ₂ and Q ₃ remain in an off state before being turned on in response to the switching signals V _GQ2 and V _GQ3 . That is, in the fourth time intervals t ₃ to t ₄ , similarly to the first time intervals t ₀ to t ₂ , all of the first to fourth switching elements Q ₁ to Q ₄ are turned off. Therefore no current path is created. However, the primary winding terminal of the resonant transformer (TR) (N ₁₎ the primary side resonance current (I _T1) change occurs and, the primary side resonance current (I _T1) by the second and third switching devices (Q _2, Q ₃ ) through the antiparallel diode. The resonant current I _T2 is induced in the secondary winding end N ₂ of the resonant transformer TR, and a current path is formed through the antiparallel diodes of the sixth and seventh switching elements Q ₆ and Q ₇ . The secondary side resonance current I _T2 flows. In addition, since the third and fourth auxiliary switching elements S _A3 and S _A4 are turned on in the fourth time interval t ₃ to t ₄ , the secondary side excitation current I _A2 is the secondary side inductor L. _A2 ). Therefore, the resonance current induced in the secondary winding end N ₂ by the primary resonance current I _T1 is represented by Equation 1 below.

The operation in the fifth time interval t ₄ to t ₅ is conceptually the same as the second time interval t ₁ to t ₂ , and the operation in the sixth time interval t ₅ to t ₆ is conceptually Since it is the same as the 3 time intervals t ₂ to t ₃ , it will not be described.

As a result, the bidirectional SLLC resonant converter according to the present invention shown in FIG. 7 has a leakage inductance L _l1 and a secondary winding end N _{2 of the} primary winding end N ₁ of the resonance transformer TR in the forward power transfer operation. The LLC resonance characteristic of the secondary side 120 is improved by using the resonance characteristics of the leakage inductance L _l2 , the resonance capacitor C _s provided in the secondary side 120, and the secondary side inductor L _A2 . It is operated to appear. (Here, it is assumed that the magnetizing inductance of the resonant transformer TR is very large, and the description of the present invention ignores the magnetizing inductance.)

Therefore, the primary side resonant current I _T1 operated at a large current at the primary side end 110 corresponding to the low voltage of the first DC power supply V _in is turned off and the first and second auxiliary switches S _A1 are turned off. Primary winding end of the first to fourth switching elements Q ₁ , Q ₂ , Q ₃ and Q ₄ and the resonant transformer TR without flowing to the primary auxiliary inductor L _A1 by S _A2 . The resonant current I _T1 flows through the secondary side inductor L _A2 together with N ₁ ) to act as an LLC resonant converter having high gain characteristics.

FIG. 11 is an operation waveform diagram of a reverse operation of the bidirectional SLLC resonant converter of FIG. 7, and FIGS. 12 and 13 are diagrams for explaining the reverse operation of the bidirectional SLLC resonant converter of FIG.

Referring to the reverse operation of the bidirectional SLLC resonant converter of FIG. 11, the reverse operation of the bidirectional SLLC resonant converter of FIG. 11 is similar to the forward operation of six time periods (t ₀ to t ₁ ) of the first to sixth time intervals. (t ₁ ~ t ₂ ), (t ₂ ~ t ₃ ), (t ₃ ~ t ₄ ), (t ₄ ~ t ₅ ), (t ₅ ~ t ₆ )).

In FIG. 11, the voltage V _cd represents the voltage level between the secondary third node Nd23 and the secondary fourth node Nd24.

In the reverse operation, the switching in which the fifth and eighth switching elements Q ₅ and Q ₈ and the sixth and seventh switching elements Q ₆ and Q ₇ of the secondary side terminal 120 are applied corresponding to the respective gates. It is alternately turned on / off in response to the voltage levels of the signals V _GQ5 to V _GQ8 . The fifth to eighth switching elements Q ₅ to Q ₈ each have a fixed duty ratio (for example, 50%) and alternately operate switching signals V _GQ5 and V _GQ8 and switching signals V _{GQ6 and} V. _GQ7 ) is turned on and off in response. However, the first to fourth switching elements Q ₁ to Q ₄ of the primary side end 110 remain off in the reverse operation. Therefore, the first to fourth switching elements Q ₁ to Q ₄ of the primary side end 110 operate as rectifier diodes as antiparallel diodes. In the reverse operation, the third and fourth auxiliary switching elements S _A3 and S _A4 of the secondary end 120 are always turned off, and the first and the first ends of the primary end 110 are turned off. 2 The auxiliary switching elements S _A1 and S _A2 are always turned on. In the reverse operation, since the third and fourth auxiliary switching elements S _A3 and S _A4 of the secondary end 120 are all turned off to have the LLC resonance gain characteristic having the high gain characteristic, the third and fourth auxiliary switching elements S _A3 and S _A4 are turned off. The secondary auxiliary inductor L _{A2 at the} secondary end is not connected to the secondary third and fourth nodes Nd23 and Nd24, and the secondary resonator is not connected to the secondary auxiliary inductor L _A2 . Instead, since the first and second auxiliary switching elements S _A1 and S _A2 of the primary end are always turned on, the primary auxiliary inductor L _A1 is connected to the primary resonator.

As shown in Figs. 11 to 13, the reverse operation is also similar to the forward operation shown in Figs. Therefore, reverse operation will not be described in detail. However, in the reverse operation, a change in the secondary side resonant current I _T2 occurs at the secondary winding end N _{2 of the} resonant transformer TR, and thus resonates at the primary winding end N ₁ of the resonant transformer TR. Current is induced

The resonance current induced in the primary winding end N ₁ is represented by Equation 2 as a sum of the primary side resonance current I _T1 and the primary side exciting current I _A1 .

Where n is the winding ratio (n = N ₂ / N ₁ ) of the resonant transformer TR.

Therefore, when the low voltage stage of the primary side is viewed from the high voltage stage of the secondary side of the resonant converter, as shown in FIG. 2, it operates like an LLC resonant converter having high gain characteristics.

Therefore, in the reverse power transfer operation, the leakage inductance L _l2 of the secondary winding end N ₂ of the resonant transformer TR and the leakage inductance L _l1 and the secondary side 120 of the primary winding end N _{1 are} shown. The resonance characteristics of the resonant capacitor C _s and the primary auxiliary inductor L _{A1 included in} the second side 120 are operated to show the LLC resonance characteristics.

14 and 15 show another embodiment of a bidirectional SLLC resonant converter according to the present invention, FIG. 14 shows a half bridge bidirectional SLLC resonant converter, and FIG. 15 shows a push-pull bidirectional SLLC resonant converter. Represents a converter.

The configuration of the half bridge bidirectional SLLC resonant converter of FIG. 14 is similar to the full bridge bidirectional SLLC resonant converter of FIG. 7. The first DC power source V _in and the second DC power source V _o , and the primary side and secondary side ends ( The resonant converter unit 200 having the 210 and 220 is provided. Here, the first DC power supply V _in has a lower voltage level than the second DC power supply V _o .

The primary end 210 of the resonant converter 200 is a primary capacitor connected in parallel with the first DC power supply (V _in ) between the primary first node (Nd11) and the primary second node (Nd12). The primary side switching part connected in parallel with the primary capacitor part between the primary side first node Nd11 and the primary second node Nd12, and the primary side connected between the primary side capacitor part and the primary side switching part And a primary side auxiliary circuit portion connected in parallel with the primary side resonance portion between the resonator portion and the primary side first switching element portion and the primary side second switching element portion.

The primary capacitor unit includes first and second capacitors C ₁ and C ₂ connected in series between the primary side first node Nd11 and the primary side second node Nd12, and the primary side switching unit 1 includes: First and second switching elements Q ₁ and Q ₂ are connected in series between the first side node Nd11 and the second side node Nd12.

That is, the primary end 210 of the resonant converter unit 200 of FIG. 14 is compared with the primary end 110 of the resonant converter unit 100 of FIG. 7, instead of the first capacitor C _in . In contrast to FIG. 7, since the primary side capacitor unit includes two capacitors C ₁ and C ₂ , the primary side switching unit includes only the first and second switching elements Q ₁ and Q ₂ . With only.

The secondary end 220 also has a structure symmetrical with the primary end 210 as shown in FIG. 14, but similarly to the full bridge bidirectional SLLC resonant converter of FIG. Unlike the vehicle side resonator, a resonant capacitor C _s is provided. The reason why only the secondary resonator includes the resonant capacitor C _s is because the voltage level of the second DC power supply V _o is set higher than that of the first DC power supply V _in as in the full bridge bidirectional SLLC resonant converter. .

The push-pull bidirectional SLLC resonant converter of FIG. 15 also includes a resonant converter 300 having a first DC power supply V _in , a second DC power supply _Vo , and primary and secondary side ends 310 and 320. Equipped. Here, the first DC power supply V _in has a lower voltage level than the second DC power supply V _o .

The secondary end 320 of the push-pull bidirectional SLLC resonant converter of FIG. 15 has the same configuration as the secondary side 120 of the full bridge bidirectional SLLC resonant converter of FIG. 7. However, the primary side 310 has a separate configuration.

The primary end 310 of the push-pull bidirectional SLLC resonant converter may include a first capacitor connected in parallel with the first DC power supply V _in between the primary first node Nd11 and the primary second node Nd12. C _in ), between the primary side first node Nd11 and the primary side second node Nd12, the primary side first resonance switching unit and the primary side second resonance switching unit connected in parallel with the first capacitor C _in . And a primary auxiliary circuit unit connected between the primary resonance first switching unit and the primary secondary resonance switching unit.

The primary side first resonant switching unit is connected to the first winding end N ₁₁ and the primary side of the resonant transformer TR connected in series between the primary side first node Nd11 and the primary side second node Nd12. The second winding of the primary side of the resonant transformer TR having an element Q ₁ and connected in series between the primary side first node Nd11 and the primary side second node Nd12. A stage N ₁₂ and a second switching element Q ₂ are provided.

In addition, the primary side auxiliary circuit part includes the primary side third node Nd13 and the primary side second winding end N ₁₂ and the second switching between the primary side first winding end N ₁₁ and the first switching element Q ₁ . Primary secondary inductors L _A1 connected between the primary fourth node Nd14 between the elements Q ₂ and connected in series between the primary third node Nd13 and the primary fourth node Nd14. ) And primary side bidirectional auxiliary switching element. The primary bidirectional auxiliary switching device unit includes first and second auxiliary switching devices S _A1 and S _A2 connected in parallel to each other. Therefore, the primary side auxiliary inductor L _A1 is connected in parallel with the primary side resonator according to the turn-on / off operations of the first and second auxiliary switching elements S _A1 and S _A2 .

The bidirectional SLLC resonant converter of FIGS. 14 and 15 is a half bridge and push-pull bidirectional SLLC resonant converter compared to the bidirectional SLLC resonant converter of FIG. 7, but the basic operation principle is the same as that of the full bridge bidirectional SLLC resonant converter of FIG. 7. The operation of the bidirectional SLLC resonant converter of Figs. 14 and 15 is not described separately.

Fig. 16 shows the resonance characteristics of the bidirectional SLLC resonant converter according to the present invention, and Fig. 17 shows an application example of the bidirectional SLLC resonant converter according to the present invention.

Figure interactive two-way SLLC resonant converter 17 to the second DC power source (V _o), instead of comprising a PWM inverter unit 150 to the secondary side. The PWM inverter unit 150 is a system-linked power supply and is a DC-AC inverter (DAC). In addition, the PWM inverter unit 150 converts DC / DC from the primary end 110 to the DC voltage applied to the secondary end 120 to an AC voltage, or converts the AC voltage applied from the AC power supply voltage AC. It is converted to direct current and applied to the secondary side 120 of the bidirectional SLLC resonant converter.

In the forward operation mode of the SLLC resonant converter for bidirectional power transfer according to the present invention, it is set _in the input voltage condition of the highest first DC power supply (V _in ) when power is transferred from the primary side to the secondary side. When the output voltage (V _o ) of the second DC power supply is to be controlled, it is set to be switched at the normalized resonant frequency (f _s / f _r = f _n ) or slightly discontinuous section, and the primary side 110 of the input voltage of the first DC power source (V _in) is constant an output voltage of the second DC power to the lower voltage by increasing the secondary-side end a gain sikimeuro move the switching frequency at a low frequency which is (V _o) via a variable frequency control Control voltage and power. The reason for switching in the frequency range lower than the normalized resonant frequency (f _s / f _r = f _n ) during the forward operation mode is that firstly, the output voltage V _{o of the} secondary end is input to the primary end 110. Since it is higher than the voltage V _in , the resonance current I _T2 rectified through the antiparallel diode (or body diode) of the switching elements Q ₅ , Q ₆ , Q ₇ and Q ₈ of the secondary side terminal 120. This is to prevent the short circuit current that can be generated during the reverse recovery time of the anti-parallel diode (or body diode) of the secondary switching elements (Q ₅ , Q ₆ , Q ₇ , Q ₈ ) because it operates in the discontinuous mode. Secondly, since the gain change is not large in the frequency region higher than the normalized resonant frequency f _n , it is difficult to control the constant voltage and power.

In addition, in the reverse operation mode of the SLLC resonant converter for bidirectional power transfer according to the present invention, the low input voltage of the primary side 110 at the output voltage V _o of the secondary side 120 is reversed. Since the primary and secondary winding ratios of the transformer set by the input / output voltage conditions of the forward operation mode are determined at the time of power transfer to V _in ), as shown in FIG. 17, the reverse direction is determined according to the operation of the PWM inverter 150 connected to the power system. In the operation mode, the output voltage V _o of the secondary side terminal 120 is always set to a fixed voltage. In the reverse operation mode, the normalized resonance frequency (f _s / f) of the gain characteristic shown in FIG. _{At the} point _r = f _n ), the input voltage (V _in ) of the primary side 110 is set to the highest voltage, so the normalized resonant frequency (f _s / f _r = f _n to adjust the gain to a lower voltage) Switch to a frequency higher than the point Although the gain should be lowered, as shown in the gain characteristic of Fig. 16, there is no gain change at light loads above the normalized resonant frequency (f _s / f _r = f _n ), which limits the gain control through variable switching frequency control. There is a problem in that the efficiency is reduced such that the circulating resonance current increases with the continuous mode resonance current.

Although FIG. 17 shows only an application example for the full bridge bidirectional SLLC resonant converter of FIG. 7, the same applies to the half bridge and push-pull bidirectional SLLC resonant converters of FIGS. 14 and 15.

Figure 18 shows another embodiment of a bidirectional SLLC resonant converter in accordance with the present invention.

The bidirectional SLLC resonant converter of FIG. 18, like the other bidirectional SLLC resonant converters described above, includes a first DC power supply (V _in ) and a second DC power supply (V _o ), and primary and secondary side ends 410 and 420. The resonance converter 400 is provided. In addition, the first DC power supply V _in has a lower voltage level than the second DC power supply V _o .

The primary side end 410 is a primary side first resonant converter unit and a primary side connected in parallel with the first DC power supply V _in between the primary side first node Nd11 and the primary side second node Nd12. A primary side second resonant converter unit is connected between the primary node Nd11 and the primary side second node Nd12 in parallel with the primary side first resonant converter unit.

The primary side first resonant converter unit is connected to the first DC power supply V _in parallel between the primary side first node Nd11 and the primary side second node Nd12, and the primary side eleventh switching element unit and the primary side agent. A primary side first switching unit having a 12 switching element portion, a primary side first resonating portion and a primary side 11th switching element portion and a primary side connected between the primary side 11th switching element portion and the primary side 12th switching element portion; And a first side first auxiliary circuit part connected in parallel with the first side first resonator part between the twelfth switching element parts.

The primary side eleventh switching element unit includes primary side eleventh and twelfth switching elements Q ₁ and Q ₂ connected in series between the primary side first node Nd11 and the primary side second node Nd12. The primary side 12th switching element unit includes primary side 13th and 14th switching elements Q ₃ and Q ₄ connected in series between the primary side first node Nd11 and the primary side second node Nd12.

The primary side first resonator is between the primary side third node Nd13 between the primary side eleventh and twelfth switching elements Q ₁ and Q ₂ and the primary side 13th and 14th switching elements Q ₃ and Q ₄ . Is disposed between the primary side fourth node Nd14. The primary side first resonator includes a first winding end N ₁₁ of the first resonant transformer T ₁ between the primary side third node Nd13 and the primary side fourth node Nd14. L _l11 denotes a leakage inductance of the primary side first coil end (N _11).

The primary side auxiliary circuit is connected between the primary side third node Nd13 and the primary side fourth node Nd14 in parallel with the primary side first resonator, and the primary side third node Nd13 and the primary side first And a primary side first auxiliary inductor L _A11 and a primary side first bidirectional auxiliary switching element part connected in series between the four nodes Nd14. The primary side first bidirectional auxiliary switching element unit includes primary side eleventh and twelfth auxiliary switching elements S _A11 and S _A12 connected in parallel to each other. Accordingly, the primary side first auxiliary inductor L _A11 is connected to the primary side first resonator in parallel with the turn-on / off operations of the primary side eleventh and twelfth auxiliary switching elements S _A11 and S _A12 .

On the other hand, the primary side second resonant converter unit is connected to the primary DC power supply V _in parallel between the primary side first node Nd11 and the primary side second node Nd12 _in parallel with the primary 21st switching element unit and primary side. A primary second switching part including a twenty-second switching element part, a primary second resonator part and a primary 21st switching element part connected between the primary 21st switching element part and the primary 22nd switching element part; And a primary side second auxiliary circuit portion connected in parallel with the primary side second resonator portion between the secondary side 22nd switching element portions.

The primary 21st switching element unit includes primary 21st and 22nd switching elements S ₁ and S ₂ connected in series between the primary 1st node Nd11 and the primary 2nd node Nd12. The primary 22nd switching element unit includes primary 23rd and 24th switching elements S ₃ and S ₄ connected in series between the primary 1st node Nd11 and the primary 2nd node Nd12.

The primary second resonator is between the primary side fifth node Nd15 between the primary side 21st and 22nd switching elements S ₁ and S ₂ and the primary side 23rd and 24th switching elements S ₃ and S ₄ . Is disposed between the primary side sixth node Nd14. The primary second resonator includes a first winding end N ₂₁ of the second resonant transformer T ₂ between the primary side fifth node Nd15 and the primary side sixth node Nd16. L _l12 denotes a leakage inductance of the second winding end (N _21).

The primary second auxiliary circuit unit is connected between the primary side fifth node Nd15 and the primary side sixth node Nd16 in parallel with the primary side second resonator, and the primary side fifth node Nd15 and the primary side agent. And a second secondary auxiliary inductor L _A12 and a second secondary bidirectional auxiliary switching element part connected in series between the six nodes Nd16. The primary side second bidirectional auxiliary switching element unit includes primary side 21st and 22nd auxiliary switching elements S _A21 and S _A22 connected in parallel to each other. Accordingly, the primary secondary auxiliary inductor L _A12 is connected in parallel with the primary secondary resonator according to the turn-on / off operations of the primary 21st and 22nd auxiliary switching elements S _A21 and S _A22 .

That is, the primary side end 410 of the bidirectional SLLC resonant converter illustrated in FIG. 18 has a structure in which two primary side ends 110 of the full bridge bidirectional SLLC resonant converter illustrated in FIG. 7 are connected in parallel.

The primary end 410 further includes a first capacitor C _in that is connected in parallel with the first DC power supply V _in between the primary first node Nd11 and the primary second node Nd12. can do.

On the other hand, the secondary end 420 of the bidirectional SLLC resonant converter is connected to the secondary DC power source V _{o in} parallel between the secondary first node Nd21 and the secondary second node Nd22, respectively. and between the first resonant converter section and the secondary-side second resonant converter section and the outlet the first node (Nd21) and the secondary-side second node (Nd22) and a second DC power source (V _o) holding portion which is connected in parallel.

The rectifier includes first and second diodes D ₁ and D ₂ connected in series between the secondary side first node Nd21 and the secondary side second node Nd22. The first and second diodes D ₁ and D ₂ are both disposed such that the cathode faces the secondary first node Nd21.

Secondary side first resonant converter section corresponding to the primary side first resonant converter section secondary side 15th and 16th switching connected in series between the secondary side first node (Nd21) and the secondary side second node (Nd22) Between the secondary side first resonating portion and the secondary side first switching element portion having the elements Q ₅ , Q ₆ and between the secondary side first switching element portion and the rectifying portion And a secondary side first auxiliary circuit connected in parallel with the secondary side first resonator.

The secondary side first resonator is a secondary side between the secondary side third node Nd23 between the secondary side 15th and 16th switching elements Q ₅ and Q ₆ and the first and second diodes D ₁ and D ₂ . It is arranged between the fourth nodes Nd24. Second winding of the first resonant capacitor C s ₁ and the first resonant transformer T ₁ connected in series between the second side third node Nd23 and the second side fourth node Nd24. A stage N ₁₂ is provided. L _l21 denotes a leakage inductance of the second winding end (N _12).

The secondary side first auxiliary circuit part is connected between the secondary side third node Nd23 and the secondary side fourth node Nd24 in parallel with the secondary side first resonator, and the secondary side third node Nd23 and the secondary side third part are connected in parallel. And a secondary side first auxiliary inductor L _A21 and a secondary side first bidirectional auxiliary switching element part connected in series between the four nodes Nd24. The secondary side first bidirectional auxiliary switching element unit includes secondary side eleventh and twelfth auxiliary switching elements S _A31 and S _A32 connected in parallel to each other. Accordingly, the secondary side first auxiliary inductor L _A21 is connected to the secondary side first resonator in parallel with the turn-on / off operations of the secondary side 11th and twelfth auxiliary switching elements S _A31 and S _A32 .

On the other hand, the secondary-side second resonant converter unit has a configuration corresponding to the primary-side second resonant converter unit and is connected in series between the secondary-side first node Nd21 and the secondary-side second node Nd22. Secondary side second switching element portion having switching elements S ₅ , S ₆ , and secondary side second resonating portion connected between secondary side second switching element portion and rectifying portion and secondary side second switching element portion and rectifying portion And a secondary side second auxiliary circuit connected in parallel with the secondary side second resonator.

The secondary side second resonator is disposed between the secondary side fifth node Nd25 and the fourth node Nd24 between the secondary side 25th and 26th switching elements S ₅ and S ₆ . The second winding of the second resonant capacitor C _s2 and the second resonant transformer T ₂ connected in series between the secondary side fifth node Nd25 and the secondary side fourth node Nd24. A stage N ₂₂ is provided. L _l22 represents a leakage inductance of the second winding end N ₂₂ .

The secondary side secondary auxiliary circuit part is connected between the secondary side fifth node Nd25 and the secondary side fourth node Nd24 in parallel with the secondary side second resonator, and the secondary side fifth node Nd25 and the secondary side secondary part. A secondary side first auxiliary inductor (L _A22 ) and a secondary side second bidirectional auxiliary switching device portion connected in series between the four nodes (Nd24). The secondary side second bidirectional auxiliary switching element unit includes secondary side 21st and 22nd auxiliary switching elements S _A41 and S _A42 connected in parallel to each other. Accordingly, the secondary side secondary auxiliary inductor L _A22 is connected in parallel with the secondary side second resonator according to the turn-on / off operations of the secondary side 21 and 22nd auxiliary switching elements S _A41 and S _A42 .

The bidirectional auxiliary switching device part may be implemented by a bidirectional switching device configured in series or in parallel and a mechanical contact terminal. And applied to the secondary side, it is possible to have a high voltage gain characteristic in each forward and reverse operation by controlling the turn-on, turn-off of the bidirectional auxiliary switching element during forward and reverse power transfer.

And as with the primary stage (410) the outlet side end 420 is a secondary side first node (Nd21) and the secondary-side second node (Nd22) to a second direct current power source (V _o) to the first connected in parallel between the Capacitor _CO may be further provided.

That is, the bidirectional SLLC resonant converter of FIG. 18 has a structure in which the secondary side first resonant converter unit and the secondary side second resonant converter unit are basically connected in parallel, although the rectifiers are shared.

In FIG. 18, the polarities of the terminal voltages of the first and second transformers T ₁ and T ₂ are opposite to each other.

FIG. 19 shows an equivalent circuit of the primary end in the forward operation of the bidirectional SLLC resonant converter of FIG.

FIG. 19 is a simplified equivalent circuit seen from the secondary side in the forward operation. As described above, the bidirectional SLLC resonant converter of FIG. 18 includes a first resonant converter unit and a second resonance in which the primary side and the secondary side are connected in parallel with each other. A converter unit, the first resonant converter unit at the primary end and the first resonant converter unit at the secondary end are converted through the first resonant transformer T ₁ , and the second resonant converter unit and the secondary end at the primary end The second resonant converter unit converts through the second resonant transformer T ₂ . Thus, it operates with each individual SLLC resonance characteristic as in the simplified equivalent circuit diagram of FIG.

Therefore, when designing the transformer T ₁ and T ₂ and designing the voltage gain characteristics, the first and second resonances are operated such that the secondary constant output voltage V _o is operated at the highest pressure stage voltage V _in at the primary side at the resonance frequency point. Design the first winding end (N ₁₁ , N ₂₁ ) and the second winding end (N ₁₂ , N ₂₂ ) of the transformer (T ₁ , T ₂ ), and the constant output voltage when the primary input terminal voltage (V _in ) is lowered It is operated to increase the voltage gain by moving the switching frequency f _s to a lower frequency to maintain (V _o ).

FIG. 20 is an operation waveform diagram of the bidirectional SLLC resonant converter of FIG. 18 during forward operation, and FIGS. 21 and 22 are diagrams for explaining the forward operation of the bidirectional SLLC resonant converter of FIG.

Referring to FIGS. 20 to 22, the forward operation of the bidirectional SLLC resonant converter of FIG. 18 will be described. Similarly to FIG. 8, the sixth time intervals of the first to sixth time intervals ( (t ₀ ~ t ₁ ), (t ₁ ~ t ₂ ), (t ₂ ~ t ₃ ), (t ₃ ~ t ₄ ), (t ₄ ~ t ₅ ), (t ₅ ~ t ₆ )) Can be. However, since the forward operation of the bidirectional SLLC resonant converter of FIG. 18 is also similar to the forward operation of the bidirectional SLLC resonant converter of FIG. 8 illustrated in FIGS. 10 and 11, the first and fourth time periods (t ₀ to t _1). ), (t ₃ to t ₄ )) are omitted.

Voltage (V _a1b1) in Figure 18 is the primary side third node (Nd13) and the primary side fourth node (Nd14) indicates the voltage level between the voltage (V _a2b2) is the primary side fifth node (Nd15) and the primary side The voltage level between the sixth node Nd16 is shown.

In the forward operation, the primary side eleventh and fourteenth switching elements Q ₁ and Q ₄ and the primary side twelve and thirteenth switching elements Q ₂ and Q ₃ correspond to respective gates. They are alternately turned on / off in response to the voltage levels of the switching signals V _GQ1 to V _GQ4 . In addition, the primary side 21st and 24th switching elements S ₁ and S ₄ and the primary side 22nd and 23rd switching elements S ₂ and S ₃ are applied to the respective gates of the primary side second resonant converter unit. It is alternately turned on and off in response to the voltage levels of the switching signals V _GS1 to V _GS4 . The eleventh to fourteenth switching elements Q ₁ to Q ₄ and the twenty- _first to twenty- _fourth switching elements S ₁ to S ₄ each have a fixed duty ratio (for example, 50%) and alternately operate switching signals. It is turned on and off in response to (V _GQ1 , V _GQ4 , V _GS1 , V _GS4 ) and the switching signals (V _GQ2, V _GQ3 , V _GS2 , V _GS3 ). However, the secondary side of the first resonant converter section and the fifteenth and sixteenth switching elements (Q _5, Q ₆₎ and a secondary side of claim 25 and claim 26, the switching element 2, the resonant converter unit (S _5, S ₆₎ is during the forward motion Will remain off. Thus, the fifteenth and sixteenth switching elements Q _{5 and} Q ₆ and the 25 and 26th switching elements S _{5 and} S ₆ are antiparallel diodes and together with the rectifying diodes D ₁ and D ₂ . Perform commutation operation.

In the forward operation, the primary side 11th and twelfth auxiliary switching elements S _A11 and S _A12 and the primary side 21st and 22nd auxiliary switching elements S _A21 and S _A22 of the primary end 410 are always turned. Turn-off, the secondary side 11th and twelfth auxiliary switching elements S _A31 and S _A32 of the secondary side end 420 and the secondary side 21st and 22nd auxiliary switching elements S _A41 and S _A42 ) Is always turned on. In the forward operation, the primary 11th and 12th auxiliary switching elements S _A11 and S _A12 of the primary end 410 and the primary 21st and 22nd auxiliary switching elements S _A21 and S _A22 have high gain characteristics. Since all are turned off to have the LLC resonance gain characteristic, the primary side secondary inductor L _{A11 of the} primary side 410, which is a low voltage stage, has the primary side third and fourth nodes Nd13 and Nd14. ) Is not connected. In addition, the primary secondary auxiliary inductor L _A12 of the primary end 410 is not connected to the primary fifth and sixth nodes Nd15 and Nd16. That is, the primary first auxiliary inductor L _A11 and the primary second auxiliary inductor L _A12 do not affect resonance in the forward operation.

Instead, the secondary 11th and 12th auxiliary switching elements S _A31 and S _A32 of the secondary side ends 420 and the secondary 21st and 22nd auxiliary switching elements S _A41 and S _A42 are always turned on. The secondary side first inductor L _A21 and the secondary side secondary inductor L _A22 are respectively the secondary side third node Nd23, the secondary side fourth node Nd24, and the secondary side fifth node Nd25. And a secondary side fourth node Nd24.

The primary end 410 and the secondary end 420 of the bidirectional SLLC resonant converter of FIG. 18 have a structure in which the primary end 110 and the secondary side 120 of the bidirectional SLLC resonant converter of FIG. Since the operation in the forward direction of the bidirectional SLLC resonant converter of FIG. 18 is similar to FIGS. 10 and 11. Therefore, the operation of the individual time intervals will not be described herein. For example, only the operations of the second time intervals t ₁ to t ₂ will be described.

The polarity of the terminal voltages of the first and second resonant transformers T ₁ and T ₂ are differently connected at the primary end 410, and the first resonant transformer T ₁ is connected in series at the secondary side 420. Since the first resonant capacitor C _s1 and the secondary side first inductor L _A21 are connected, a current generated by resonance with the equivalent leakage inductance of the first and second resonant transformers T ₁ and T ₂ The inverted parallel diode and the first diode (D ₁ ) of the 16th switching element (Q ₆ ) of the secondary side are rectified, and the second resonant transformer (T ₂ ) is connected in series with the resonant capacitor (C _s2 ) and the resonant capacitor connected in series. Since the secondary side secondary inductor L _A22 is connected in parallel with (C _s2 ), the secondary side 26th switching is performed through resonance with equivalent leakage inductances of the first and second resonant transformers T ₁ and T ₂ . Rectification is performed through the inverse parallel diode of the element S ₆ and the first diode D ₁ .

Therefore, the forward operation of the bidirectional SLLC resonant converter of FIG. 18 is equivalent to the secondary side secondary auxiliary inductor L _A21 , the secondary side secondary inductor L _A22 , and the first and second resonant transformers T ₁ and T ₂ . The leakage inductance and the resonance characteristics of the first and second resonant capacitors C _S1 and C _S2 have high voltage gain characteristics such as the LLC resonance characteristic.

FIG. 23 shows an equivalent circuit of the secondary side stage in the reverse operation of the bidirectional SLLC resonant converter of FIG.

Fig. 23 is a simplified equivalent circuit seen from the secondary side in the reverse operation, the secondary side 420 is operated in series, and the primary side 410 is operated in a parallel circuit configuration. Accordingly, as shown in the simplified equivalent circuit diagram, the secondary side stage 420 is connected in series with each of the resonant capacitors C s ₁ and C s ₂ according to the series connection configuration operation, and leakage of the first and second resonant transformers T ₁ and T ₂ is achieved. Inductance is also connected in series to operate with SLLC resonance.

FIG. 24 is a waveform diagram illustrating a reverse operation of the bidirectional SLLC resonant converter of FIG. 18, and FIGS. 25 and 26 are diagrams for explaining the reverse operation of the bidirectional SLLC resonant converter of FIG.

25 and 26, the drawings of the first and fourth time intervals (t ₀ to t ₁ ) and (t ₃ to t ₄ ) are omitted for convenience.

In FIG. 24, the voltage V _cd represents the voltage level between the secondary third node Nd23 and the secondary fourth node Nd24, and the voltage V _de represents the secondary fourth node Nd24 and the secondary side. The voltage level between the fifth node Nd25 is shown.

In the reverse operation, the secondary 11th and 22nd switching elements Q ₅ and S ₆ and the secondary 12th and 21st switching elements Q ₆ and S ₅ each have a fixed duty ratio (50%) and are turned-on. On, turn-off switching operation, the primary side 11th to 14th switching elements (Q ₁ , Q _2, Q _3, Q ₄ ) and the primary side 21st to 24th switching elements (S ₁ , S _2, S _{3) ,} S ₄ ) remains turned off to perform rectification as an inverse parallel diode. The secondary side 11th and twelfth auxiliary switching elements S _A31 and S _A32 and the secondary side 21st and 22nd auxiliary switching elements S _A41 and S _A42 are always turned off and do not operate. And the twelfth auxiliary switching elements S _A11 and S _A12 and the primary side 21st and 22nd auxiliary switching elements S _A21 and S _A22 are always turned on.

Since the operation of each time interval in the bidirectional SLLC resonant converter reverse operation is similar to that of FIG. 12 and 13 as the forward operation, it will not be described in detail here.

Therefore, in the reverse operation, the equivalent leakage inductance of the first and second auxiliary inductors L _A11 and L _A12 and the first and second resonant transformers T ₁ and T ₂ and the first and second resonant capacitors C _s1 , C _s2 ) has high voltage gain characteristics like LLC resonant characteristics.

At this time, the secondary terminal voltages of the first and second resonant transformers during the switching operation of the secondary 11th and 22nd switching elements Q ₅ and S ₆ and the secondary 12th and 21st switching elements Q ₆ and S ₅ are switched. As (1/2) V _o is applied to (V _cd , V _ed ), the voltage gain is lowered to 1/2 so that it operates during the discontinuous period through variable frequency control from the resonant frequency to the low frequency as in the forward operation.

27 shows another configuration of the bidirectional auxiliary switching element section in the bidirectional SLLC resonant converter according to the present invention.

In the present invention, the auxiliary switching elements of the bidirectional auxiliary switching element portion (S _A1 , S _A2 ), (S _A3 , S _A4 ), (S _A11 , S _A12 ), (S _A21 , S _A22 ), (S _A31 , S _A32 ), (S _A41 , S _A42 )) may be replaced by a solid state relay (SSR) or a relay and a contact, as well as switching elements such as Power Mosfet, IGBT, Power TR, and SCR, as shown in FIG. 27. . And the positions may change with each other. In addition, the auxiliary switching elements of the bidirectional auxiliary switching element part ((S _A1 , S _A2 ), (S _A3 , S _A4 ), (S _A11 , S _A12 ), (S _A21 , S _A22 ), (S _A31 , S _A32 ), (S _A41 , S _A42 )) may be a bidirectional auxiliary switching device without an anti-parallel diode (body diode) connected in parallel in opposite directions.

Although not shown, the first and eighth switching elements Q ₁ to Q ₄ , the primary side eleventh to fourteenth switching elements Q ₁ to Q ₄ , and the primary side 21st to 24th switching elements S ₁ to S ₄ ), secondary side 15th and 16th switching elements Q _{5 and} Q ₆ and secondary side 25th and 26th switching elements S ₅ and S ₆ are also implemented as one of Power Mosfet, IGBT, Power TR, SCR. It may be.

28 and 29 show waveforms observed in the experimental results during the forward operation and the reverse operation of the bidirectional SLLC resonant converter according to the present invention, respectively.

FIG. 28 is a test result of 1.5kW output capacity for the bidirectional SLLC resonant converter of FIG. 18. In the forward power transfer mode, the secondary output is constant _in the range of 41 V to 60 V _in the range of the primary input voltage V _in voltage (V _o) for 400V / 3.75A were tested for rated output 1.5kW, reverse mode, the secondary side constant output voltage (V _o) the range of the primary input control voltage (V _in) at 400V conditions (41V~ 63V / 25A ~ 36.59A) and rated power 1.5kW respectively. The experimental conditions and the main ratings are shown in Table 1 and Table 2.

Forward Power Transfer Mode Voltage (V _in ) 41V to 60V Forward output capacity ( _Po ) 400V / 3.75A (1.5kW) Switching frequency (f _s ) / resonant frequency (f _r ) 30.77 kHz to 42.26 kHz / 56.10 kHz Reverse power transfer mode Voltage (V _o ) 400V Reverse output capacity (P _in ) 41 V to 60 V / 25 A to 36.59 A (1.5 kW) Switching frequency (f _s ) / resonant frequency (f _r ) 41.29 kHz to 48.31 kHz / 57.68 kHz

Table 1 shows the experimental conditions of the bidirectional SLLC resonant converter.

Magnetic inductance (L _p / L _s ) 40.96uH / 1.539mH 1st and 2nd side leakage inductance in forward _direction (L _l11 / N ² L _1l12 ) 1.68uH / 3.47uH 1st and 2nd side leakage inductance in reverse direction (L _l11 / N ² / L _l12 ) 59.27uH / 123.7uH Equivalent Leakage Inductance (L _eq ) 4.868uH Turn ratio (N ₁ / N ₂ ) 0.1667 Resonant Capacitors (C _s1 , C _s2 ) 44 nF Auxiliary Inductors (L _A11 , L _A12 / L _A21 , L _A22 ) 14.49uH / 826.2uH Primary main switching element (Q _{1 to} Q ₄ , S _{1 to} S ₄ ) IRFP4468 (100V, 290A) Secondary main switching element (Q _{5 to} Q ₈ ) 47N60CFD (600V, 46A) The secondary side diodes (D _{1 to} D ₂ ) DSEP30-06 (600V, 30A) Primary side auxiliary switch (S _A11, S _A12, S _A21, S _A22 ) IRFP4468 (240V, 130A) Secondary auxiliary switch (S _A31, S _A32, S _A41, S _A42 ) H30R1602 (1600 V, 30 A) Applied Control IC MC34067

Table 2 shows the bidirectional SLLC resonant converter parameters and the devices used.

Figure 30 shows the efficiency characteristics for the primary input voltage range in the forward operation of the bidirectional SLLC resonant converter according to the present invention, Figure 31 shows the control range of the primary input voltage in the reverse operation of the bidirectional SLLC resonant converter according to the present invention. Efficiency characteristics.

As shown in Figs. 30 and 31, the bidirectional SLLC resonant converter of Fig. 18 has a secondary constant control output voltage (V _o ) of 400 V at a primary input voltage (V _in ) of 45 V _{in the} forward operation mode, and a maximum load (1.5 kW). Efficiency was measured at 94.34%, and the constant output voltage (V _o ) in the reverse operation mode was 400 V at 93 V, and the maximum load (1.5 kW) was applied at 50 V at the primary input control voltage (V _in ) during the secondary switching operation. Showed efficiency characteristics. In other words, it exhibits high efficiency characteristics.

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 can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

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.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (53)

Connected to a first DC power source to induce a change in current at the first winding end of each of the first and second resonant transformers in the forward operation, and to the first and second auxiliary inductors in the reverse operation; The current change induced in the first winding ends of the first and second resonant transformers by the current change of the second winding ends of the first and second resonant transformers respectively connected to the first winding ends of the second resonant transformers, respectively. A primary side end configured to charge the first DC power supply to have an LLC resonance characteristic; And
It is connected to a second DC power supply having a higher voltage level than the first DC power supply, induces a current change in the second winding end of each of the first and second resonant transformers in the reverse operation, and in the forward operation, The first and second auxiliary inductors are connected to the second winding ends of the first and second resonant transformers and the first and second resonant capacitors, respectively, so that the first and second auxiliary inductors And a secondary side end configured to charge the second DC power so that a current change induced in each of the first and second winding ends of the first and second resonant transformers has an LLC resonance characteristic.
The method of claim 1, wherein the primary end
A primary side first resonant converter unit connected in parallel with the first DC power source between a primary side first node and a primary side second node; And
And a primary side second resonant converter unit connected in parallel with the primary side first resonant converter unit between the primary side first node and the primary side second node.
The method of claim 2, wherein the primary side first resonant converter unit
A primary side first switching unit including a primary side eleventh switching element unit and a primary side twelfth switching element unit connected in parallel with the first DC power source, respectively, between the primary side first node and the primary side second node;
A primary side first resonator connected between the primary side eleventh switching element portion and the primary side twelfth switching element portion; And
And a primary side first auxiliary circuit unit connected in parallel with the primary side first resonator between the primary side eleventh switching element portion and the primary side twelfth switching element portion.
The method of claim 3, wherein the primary side eleventh switching element portion
A primary side eleventh and twelfth switching elements connected in series between the primary side first node and the primary side second node,
The first side 12th switching device unit
And a primary side thirteenth and fourteenth switching elements connected in series between the primary side first node and the primary side second node.
The method of claim 3, wherein the primary side first resonator
A first winding end of the first resonant transformer between the primary third node between the primary side eleventh and twelfth switching elements and the primary fourth node between the primary side thirteenth and fourteenth switching elements; Bidirectional SLLC resonant converter, characterized in that.
The method of claim 5, wherein the primary side first auxiliary circuit portion
A primary side first auxiliary inductor and a primary side first bidirectional auxiliary switching device unit connected in series between the primary side third node and the primary side fourth node in parallel with the primary side first resonator;
The primary side first bidirectional auxiliary switch element unit
A bidirectional SLLC resonant converter having a primary side eleventh and twelfth auxiliary switching elements, wherein the primary side eleventh and twelfth auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 2, wherein the primary side second resonant converter unit
A primary side second switching unit including a primary side 21 switching element unit and a primary side 22 switching element unit connected in parallel with the first DC power source respectively between the primary side first node and the primary side second node;
A second secondary resonance part connected between the primary 21st switching element part and the primary 22nd switching element part; And
And a second secondary auxiliary circuit unit connected in parallel with the primary second resonator unit between the primary 21st switching element unit and the primary 22nd switching element unit.
The method of claim 7, wherein the primary-side 21 switching element portion
And primary side twenty-first and twenty-second switching elements connected in series between the primary side first node and the primary side second node,
The 22nd switching element portion of the primary side
And a primary 23rd and a 24th switching element connected in series between the primary side first node and the primary side second node.
The method of claim 8, wherein the primary side second resonator
A first winding end of the second resonant transformer between the primary fifth node between the primary 21st and 22nd switching elements and the primary 6th node between the primary 23rd and 24th switching elements Bidirectional SLLC resonant converter, characterized in that.
The method of claim 9, wherein the secondary side secondary circuit portion
And a primary side second auxiliary inductor and a primary side second bidirectional auxiliary switching element part connected in series between the primary side fifth node and the primary side sixth node in parallel with the primary side second resonator,
The primary side second bidirectional auxiliary switch element unit
And a primary 21st and 22nd auxiliary switching elements, wherein the primary 21st and 22nd auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 10, wherein the secondary side end
A secondary side first resonant converter unit connected in parallel with the second DC power source between a secondary side first node and a secondary side second node;
A secondary side second resonant converter unit connected in parallel with the secondary side first resonant converter unit between the secondary side first node and the secondary side second node; And
A rectifier connected in parallel with the second DC power source between the secondary side first node and the secondary side second node; Bidirectional SLLC resonant converter comprising: a.
The method of claim 11, wherein the rectifying unit
And a first diode and a second diode connected in series between the secondary side first node and the secondary side second node.
The method of claim 12, wherein the secondary side first resonant converter unit
A secondary side first switching element unit having secondary side 15th and 16th switching elements connected in series between the secondary side first node and the secondary side second node;
A secondary side first resonator connected between a secondary side third node between the secondary side 15th and secondary side 16th switching elements and a secondary side fourth node between the first and second diodes; And
And a secondary side first auxiliary circuit connected between the secondary side third node and the secondary side fourth node in parallel with the secondary side first resonator.
The method of claim 13, wherein the secondary side first resonator
And a second winding end of the first resonant capacitor and the first resonant transformer connected in series between the secondary third node and the secondary fourth node.
The method of claim 14, wherein the secondary side first auxiliary circuit portion
A secondary side first auxiliary inductor and a secondary side first bidirectional auxiliary switching element part connected in series between the secondary side third node and the secondary side fourth node in parallel with the secondary side first resonator;
The secondary side first bi-directional auxiliary switch element unit
And a secondary side eleventh and twelfth auxiliary switching elements, wherein the secondary side eleventh and twelfth auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 15, wherein the secondary side second resonant converter unit
A secondary side second switching element unit having secondary side 25 and 26th switching elements connected in series between the secondary side first node and the secondary side second node;
A secondary side second resonator connected between the secondary side fifth node and the secondary side fourth node between the secondary side 25th and secondary side 26th switching elements; And
And a secondary side second auxiliary circuit unit connected in parallel with the secondary side second resonator between the secondary side fifth node and the secondary side fourth node.
The method of claim 16, wherein the secondary side second resonator
And a second winding end of the second resonant capacitor and the second resonant transformer connected in series between the secondary fifth node and the secondary fourth node.
The method of claim 17, wherein the secondary side second auxiliary circuit portion
And a secondary side second auxiliary inductor and a secondary side second bidirectional auxiliary switching device unit connected in series between the secondary side fifth node and the secondary side fourth node in parallel with the secondary side second resonator.
The secondary side second bidirectional auxiliary switch element unit
A bidirectional SLLC resonant converter having secondary 21st and 22nd auxiliary switching elements, wherein the secondary 21st and 22nd auxiliary switching elements are connected to each other in parallel or in series in different current directions.
19. The bidirectional SLLC resonant converter according to claim 18, wherein the first and second winding ends of each of the first and second resonant transformers are connected with opposite polarities of terminal voltages.
The method of claim 19, wherein the primary side 11th to 14th switching element and the primary side 21st to 24th switching element
The primary side 11th and primary side 14th switching elements and the primary side 12th and primary side 13th switching elements alternately in response to a voltage level of a switching signal applied corresponding to each gate when the forward power is received. On / off, the primary 21st and primary 24th switching elements and the primary 22nd and primary 23rd switching elements are alternately turned on / off,
When receiving the reverse power, all of the primary side eleventh to fourteenth switching elements and the primary side 21st to 24th switching elements are turned off.
The secondary side 15th and 16th switching elements and the secondary side 25th and 26th switching elements
The secondary side 15th and 25th switching elements and the secondary side 16th and 26th switching elements are alternately turned on / off in response to a voltage level of a switching signal applied corresponding to each gate when the reverse power is received. ,
And the secondary side 15th and 16th switching elements and the secondary side 25th and 26th switching elements are turned off when the forward power is received.
21. The auxiliary switching device of claim 20, wherein the primary side 11th, 12th, 21st and 22nd auxiliary switching elements
All off in forward power delivery, all on in reverse power delivery,
The secondary side 11th, 12th, 21st and 22nd auxiliary switching elements
A bidirectional SLLC resonant converter characterized in that both are turned off when receiving reverse power and are turned on when receiving forward power.
22. The method of claim 21, wherein the primary side 11th to 14th switching elements and the primary side 21st to 24th switching elements
Performing rectification operation by an anti-parallel diode (body diode) when receiving the reverse power,
The secondary side 15th and 16th switching elements and the secondary side 25th and 26th switching elements
And a rectifying operation is performed by an anti-parallel diode (body diode) when the forward power is received.
23. The method of claim 22, wherein the primary side 11th to 14th switching elements, the primary side 21st to 24th switching elements, the secondary side 15th and 16th switching elements, and the secondary side 25th and 26th switching elements
Bi-directional SLLC resonant converter, characterized in that implemented by one of Power Mosfet, IGBT, Power TR, SCR.
23. The auxiliary switch according to claim 22, wherein the primary side eleventh and twelfth auxiliary switching elements, the primary side twenty-first and twenty-second auxiliary switching elements, the secondary side eleventh and twelfth auxiliary switching elements, and the secondary side twenty-first and twenty-second auxiliary switching elements. Each one
Bi-directional SLLC resonant converter, characterized in that implemented as one of Power Mosfet, IGBT, Power TR, SCR, Solid State Relay (SSR), relay and contact.
Connected to a first DC power source to induce a current change in the first winding end of the resonant transformer in the forward operation, and connect the primary auxiliary inductor with the first winding end of the resonant transformer in the reverse operation to A primary side stage configured to charge the first DC power supply such that a current change induced in the first winding end of the resonant transformer by the current change of the second winding end has an LLC resonance characteristic; And
It is connected to a second DC power supply having a higher voltage level than the first DC power supply, induces a current change in the second winding end of each of the resonant transformer in the reverse operation, and the secondary auxiliary inductor in the forward operation to the secondary transformer The second DC power supply is connected to the second winding end of the resonant capacitor and the current change induced in the second winding end of the resonant transformer by the current change of the first winding end of the resonant transformer to have the LLC resonance characteristic. Bidirectional SLLC resonant converter comprising; secondary side charging.
The method of claim 25, wherein the primary end
A primary side switching unit including a primary side first switching element unit and a primary side second switching element unit respectively connected in parallel with the first DC power source between the primary side first node and the primary side second node;
A primary side resonance part connected between the primary side first switching element part and the primary side second switching element part; And
And a primary side auxiliary circuit part connected in parallel with the primary side resonance part between the primary side first switching element part and the primary side second switching element part.
The method of claim 26, wherein the primary side switching device unit
First and second switching elements connected in series between the primary side first node and the primary side second node,
The primary side second switching element portion
And third and fourth switching elements connected in series between the primary side first node and the primary side second node.
28. The method of claim 27, wherein the primary side resonator
And a first winding end of the resonant transformer between the primary third node between the first and second switching elements and the primary fourth node between the primary third and fourth switching elements. Bidirectional SLLC resonant converter.
29. The circuit of claim 28, wherein the primary side auxiliary circuit unit
A primary auxiliary inductor and a primary bidirectional auxiliary switching element part connected in series between the primary third node and the primary fourth node in parallel with the primary resonator;
The primary side bidirectional auxiliary switch element unit
A bidirectional SLLC resonant converter having first and second auxiliary switching elements, wherein the first and second auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 29, wherein the secondary side end
A secondary side switching unit including a secondary side first switching element unit and a secondary side second switching element unit respectively connected in parallel with the first DC power source between the secondary side first node and the secondary side second node;
A secondary side resonance part connected between the secondary side first switching element part and the secondary side second switching element part; And
And a secondary side auxiliary circuit part connected in parallel with the secondary side resonance part between the secondary side first switching element part and the secondary side second switching element part.
The method of claim 30, wherein the secondary switching element portion
Fifth and sixth switching elements connected in series between the secondary side first node and the secondary side second node,
The secondary side second switching element portion
And a seventh and eighth switching elements connected in series between the secondary side first node and the secondary side second node.
32. The method of claim 31, wherein the secondary side resonator
A second winding end of the resonant capacitor and the resonant transformer connected in series between the second side third node between the fifth and sixth switching elements and the second side fourth node between the seventh and eighth switching elements; Bidirectional SLLC resonant converter characterized in that it comprises.
33. The method of claim 32, wherein the secondary side auxiliary circuit portion
A secondary side auxiliary inductor and a secondary side bidirectional auxiliary switching element part connected in series between the secondary side third node and the secondary side fourth node in parallel with the secondary side resonator;
The secondary side bi-directional auxiliary switch element unit
And a third and fourth auxiliary switching elements, wherein the third and fourth auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 33, wherein the first to fourth switching device
The first and fourth switching elements and the second and third switching elements are alternately turned on / off in response to a voltage level of a switching signal applied corresponding to each gate when the forward power is received;
When the reverse power is received, all of the first to fourth switching devices are turned off.
The fifth to eighth switching elements
The fifth and eighth switching elements and the fifth and seventh switching elements are alternately turned on / off in response to a voltage level of a switching signal applied corresponding to each gate when the reverse power is received;
Both of the fifth to eighth switching elements are turned off when the forward power is received.
The method of claim 34, wherein the first and second auxiliary switching device
All off in forward power delivery, all on in reverse power delivery,
The third and fourth auxiliary switching device
A bidirectional SLLC resonant converter characterized in that both are turned off when receiving reverse power and are turned on when receiving forward power.
The method of claim 35, wherein the first to fourth switching device
Performing rectification operation by an anti-parallel diode (body diode) when receiving the reverse power,
The fifth to eighth switching elements
And a rectifying operation is performed by an anti-parallel diode (body diode) when the forward power is received.
The method of claim 36, wherein the first to eighth switching device
Bi-directional SLLC resonant converter, characterized in that implemented by one of Power Mosfet, IGBT, Power TR, SCR.
The method of claim 36, wherein each of the first to fourth auxiliary switching elements
Bi-directional SLLC resonant converter, characterized in that implemented as one of Power Mosfet, IGBT, Power TR, SCR, Solid State Relay (SSR), relay and contact.
The method of claim 25, wherein the primary end
A primary side switching unit including first and second switching elements connected in series between the primary side first node and the primary side second node;
A primary capacitor unit having first and second capacitors connected in series between the primary side first node and the primary side second node;
A primary side resonator having a first winding end of the resonant transformer connected between a primary side third node between the first and second switching elements and a primary side fourth node between the first and second capacitors; And
And a secondary side auxiliary circuit unit connected in parallel with the primary side resonance unit between the primary side third node and the primary side fourth node.
40. The method of claim 39, wherein the secondary side auxiliary circuit portion
A primary auxiliary inductor and a primary bidirectional auxiliary switching element part connected in series between the primary third node and the primary fourth node in parallel with the primary resonator;
The primary side bidirectional auxiliary switch element unit
A bidirectional SLLC resonant converter having first and second auxiliary switching elements, wherein the first and second auxiliary switching elements are connected to one another in parallel or in series in different current directions.
41. The method of claim 40, wherein the secondary side end
A secondary side switching unit including third and fourth switching elements connected in series between the secondary side first node and the secondary side second node;
A secondary capacitor unit including third and fourth capacitors connected in series between the secondary side first node and the secondary side second node;
A first winding end of the resonant capacitor and the resonant transformer connected in series between a second side third node between the third and fourth switching elements and a second side fourth node between the third and fourth capacitors; A secondary side resonator; And
And a secondary side auxiliary circuit unit connected in parallel with the secondary side resonator between the secondary side third node and the secondary side fourth node.
42. The method of claim 41, wherein the secondary side auxiliary circuit portion
A secondary side auxiliary inductor and a secondary side bidirectional auxiliary switching element part connected in series between the secondary side third node and the secondary side fourth node in parallel with the secondary side resonator;
The secondary side bi-directional auxiliary switch element unit
And a third and fourth auxiliary switching elements, wherein the third and fourth auxiliary switching elements are connected to one another in parallel or in series in different current directions.
43. The method of claim 42, wherein the first to fourth switching elements
Bi-directional SLLC resonant converter, characterized in that implemented by one of Power Mosfet, IGBT, Power TR, SCR.
43. The method of claim 42, wherein each of the first to fourth auxiliary switching elements
Bi-directional SLLC resonant converter, characterized in that implemented as one of Power Mosfet, IGBT, Power TR, SCR, Solid State Relay (SSR), relay and contact.
45. The method of claim 44, wherein the primary end
A first capacitor connected in parallel with the first DC power source between the primary side first node and the primary side second node;
A resonance switching unit including a primary side first resonance switching unit and a primary side second resonance switching unit connected in parallel with the first capacitor between the primary side first node and the primary side second node; And
And a secondary side auxiliary circuit connected between the primary side first resonant switching unit and the primary side second resonant switching unit.
46. The method of claim 45, wherein the first side first resonance switching unit
A first winding end and a first switching element of the primary side of the resonant transformer connected in series between the primary side first node and the primary side second node,
The primary side second resonant switching unit includes a first side winding side of the resonant transformer and a second switching element connected in series between the primary side first node and the primary side second node. Resonant converter.
47. The apparatus of claim 46, wherein the primary side auxiliary circuit portion
A primary side connected in series between a primary side third node between the primary side first winding end and the first switching element and a primary side fourth node Nd14 between the primary side second winding end and the second switching element Auxiliary inductor and primary side bidirectional auxiliary switching element portion,
The primary side bidirectional auxiliary switch element unit
A bidirectional SLLC resonant converter having first and second auxiliary switching elements, wherein the first and second auxiliary switching elements are connected to one another in parallel or in series in different current directions.
48. The method of claim 47, wherein the secondary end
A secondary side switching unit including a secondary side first switching element unit and a secondary side second switching element unit respectively connected in parallel with the first DC power source between the secondary side first node and the secondary side second node;
A secondary side resonance part connected between the secondary side first switching element part and the secondary side second switching element part; And
And a secondary side auxiliary circuit part connected in parallel with the secondary side resonance part between the secondary side first switching element part and the secondary side second switching element part.
The method of claim 48, wherein the secondary switching element portion
Fifth and sixth switching elements connected in series between the secondary side first node and the secondary side second node,
The secondary side second switching element portion
And a seventh and eighth switching elements connected in series between the secondary side first node and the secondary side second node.
The method of claim 49, wherein the secondary side resonator
A second winding end of the resonant capacitor and the resonant transformer connected in series between the second side third node between the fifth and sixth switching elements and the second side fourth node between the seventh and eighth switching elements; Bidirectional SLLC resonant converter characterized in that it comprises.
51. The method of claim 50, wherein the secondary side auxiliary circuit portion
A secondary side auxiliary inductor and a secondary side bidirectional auxiliary switching element part connected in series between the secondary side third node and the secondary side fourth node in parallel with the secondary side resonator;
The secondary side bi-directional auxiliary switch element unit
And a third and fourth auxiliary switching elements, wherein the third and fourth auxiliary switching elements are connected to one another in parallel or in series in different current directions.
The method of claim 51, wherein the first, second and fifth to eighth switching device
Bi-directional SLLC resonant converter, characterized in that implemented by one of Power Mosfet, IGBT, Power TR, SCR.
The method of claim 51, wherein each of the first to fourth auxiliary switching elements
Bi-directional SLLC resonant converter, characterized in that implemented as one of Power Mosfet, IGBT, Power TR, SCR, Solid State Relay (SSR), relay and contact.

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