Switching power supply

Abstract

To provide a switching power supply device capable of realizing large power by parallelizing resonant circuits without increasing complementary gate drive signals.SOLUTION: In a circuit element 10a, resonant circuits are arranged in parallel. One end of a resonant capacitor Crkq of a q-th parallelized resonant circuit is connected in series to a resonant reactor Lrq and the primary winding N1q of a transformer Trq. The other end of the resonant capacitor Crkq of the q-th resonant circuit parallelized is connected to the resonant capacitor Crkq of the q-th parallelized resonant circuit in another circuit element 10a so as to configure the k-dimensional multi-phase LLC converter with a phase difference of 360° / Pk using the Pk circuit elements.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a switching power supply device that converts an input voltage into an output voltage using a plurality of LLC converters connected in parallel.

Background Art

[0002] In recent years, in order to achieve large current and low ripple as the output load increases, a multi-phase switching power supply device is known that has a plurality of operating phases (number of phases) and drives each operating phase with a phase shift (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, as the number of phases increases, the complementary gate drive signals for the complementary switches to be prepared also increase. Therefore, the control associated with the increase in the number of phases becomes complicated, and the circuit related to the control becomes large-scale, etc., and power expansion by multi-phasing cannot be easily achieved.

[0005] One aspect of the present invention provides a switching power supply device that can achieve high power by paralleling resonance circuits without increasing the complementary gate drive signals.

Means for Solving the Problems

[0006] A switching power supply device according to one aspect of the present invention comprises a plurality of half-bridge LLC converters as circuit elements, each having parallel resonant circuits. The circuit element includes a first switch element and a second switch element connected in series to both ends of a DC power supply, and m parallel resonant circuits (m is a natural number of 2 or more) each containing a resonant reactor, the primary winding of a transformer, and n (n is a natural number of 2 or more) first-order resonant capacitors to the nth-order resonant capacitors, one end of which is connected to the connection point between the first and second switch elements. The k-th order resonant capacitor (k is a natural number of 1 to n) of the parallel q-th (q is a natural number of 1 to m) resonant circuit has one end connected in series to the resonant reactor and the primary winding of the transformer, and the other end connected to the k-th order resonant capacitor of the parallel q-th resonant circuit in the other circuit elements so as to constitute a k-dimensional multi-phase LLC converter with a phase difference of 360° / Pk by Pk (Pk is an arbitrary natural number) circuit elements. Furthermore, a switching power supply device according to one aspect of the present invention comprises a plurality of half-bridge LLC converters as circuit elements, each having resonant circuits (circuit portions excluding the resonant reactor) arranged in parallel. The circuit element includes a first switch element and a second switch element connected in series to both ends of a DC power supply, a resonant reactor with one end connected to the connection point between the first switch element and the second switch element, and the other end of the resonant reactor connected to the primary winding of a transformer and m parallel resonant circuits (m is a natural number of 2 or more) each containing n (n is a natural number of 2 or more) first-order resonant capacitors to nth-order resonant capacitors. The k-th resonant capacitor (k is a natural number from 1 to n) of the parallelized q-th (q is a natural number from 1 to m) resonant circuit is connected at one end in series with the resonant reactor and the primary winding of the transformer, and at the other end is connected to the k-th resonant capacitor of the parallelized q-th resonant circuit in other circuit elements so as to constitute a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk using Pk (Pk is an arbitrary natural number) circuit elements. [Effects of the Invention]

[0007] According to one aspect of the present invention, the complementary gate drive signal can be reduced to less than the total number of circuit elements, and high power can be achieved by parallelizing the resonant circuit without increasing the complementary gate drive signal. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram shows the circuit configuration of an embodiment of a switching power supply device. [Figure 2] Figure 1 illustrates the circuit that controls the operation of the switching power supply shown in the diagram. [Figure 3] This diagram illustrates the multidimensionalization (1 to 3 dimensions) of switching power supplies. [Figure 4] This diagram illustrates the multidimensionalization (4-6 dimensions) of switching power supplies. [Figure 5] This diagram illustrates the further multi-dimensionalization of switching power supply devices. [Figure 6] This figure shows other examples of circuit element configurations. [Figure 7] This figure shows other examples of circuit element configurations. [Figure 8] This figure shows other examples of circuit element configurations. [Figure 9] This figure shows other examples of circuit element configurations. [Figure 10] This diagram illustrates the parallel and multidimensional configuration of switching power supplies. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will now be described in detail with reference to the figures. In the following embodiments, components that have the same function are denoted by the same reference numerals and their descriptions are omitted as appropriate.

[0010] Referring to Figure 1, the switching power supply unit 1 of this embodiment comprises a plurality (Σ) of half-bridge LLC converters (hereinafter referred to as circuit elements 10). Each of the 1 to n dimensions of the switching power supply unit 1 is configured as a multi-phase LLC converter. That is, the switching power supply unit 1 is a multi-phase multiplex LLC converter. Here, n is a natural number of 2 or more, and the switching power supply unit 1, which is composed of 2 or more multi-phase LLC converters, will be described below.

[0011] Circuit element 10 has a high-potential input terminal Tin connected to the positive terminal of the DC power supply Vin. + And the low-potential input terminal Tin is connected to the negative terminal of the DC power supply Vin. - It comprises a first switch element QH and a second switch element QL connected in series between them. The circuit element 10 comprises a resonant circuit including a resonant reactor Lr with one end connected to the connection point between a first switch element QH and a second switch element QL, a primary winding N1 of a transformer Tr, and n+1 resonant capacitors Cr0 to Crn. The circuit element 10 includes a rectifier and smoothing circuit that includes synchronous rectifier elements SR1 and SR2, and an output capacitor Cout, for rectifying and smoothing the voltage of the secondary winding N2 of the transformer Tr. In Figure 1, only the main circuit of circuit element 10 is shown within the solid line frame (corresponding to a module). The rectifier and smoothing circuit can employ rectification methods such as center-tap rectification, bridge rectification, voltage doubler rectification, and Cock-Walton rectification.

[0012] High potential input terminal Tin + and low-potential input terminal Tin - Between them, the input capacitor Cin is connected, and the ends of the output capacitor Cout are connected to the high-potential output terminal Vout. + and the low-potential output terminal Vout - Connected.

[0013] The resonant capacitor Cr0 has one end connected in series with the resonant reactor Lr and the primary winding N1 of the transformer Tr, and the other end connected to the low-potential input terminal Tin - Connected.

[0014] The resonance capacitors Cr1 to Crn are each connected in series at one end to the resonance reactor Lr and the primary winding N1 of the transformer Tr, and the other ends are respectively connected to the bypass terminals T1 to Tn. The other end (bypass terminal Tk) of the k-th (k is a natural number from 1 to n) resonance capacitor Crk is connected to the other end (bypass terminal Tk) of the k-th resonance capacitor Crk of the other circuit elements 10 by Pk (Pk is an arbitrary natural number) circuit elements 10 so as to constitute a k-dimensional multi-phase LLC converter with a phase difference of 360° / Pk. In this specification, regardless of the orthogonality of the dimensions, the n interconnected points of the bypass terminals T1 to Tn are each referred to as k-dimensional.

[0015] The total number Σ of the circuit elements 10 is expressed by the following formula (1) using Pk which is the number of phases of each k dimension.

[0016]

Equation

[0017] Referring to FIG. 2(a), the switching power supply device 1 includes a control circuit 20 and a selection signal generation circuit 30. The control circuit 20 alternately turns on and off the first switch element QH and the second switch element QL of the Σ circuit elements 10 by a complementary gate drive signal Gk Pk(k=1~n) Thereby. The selection signal generation circuit 30 controls the dimension selection circuit 42 by the dimension selection signal Yk to select the operation / stop of the circuit elements 10 for each dimension, and controls the phase selection circuit 41 by the phase selection signal Xk Pk(k=1~n) Thereby, the operation / stop of the Σ circuit elements 10 is selected for each dimension and each phase.

[0018] The number of phases P1 to Pn of each of the 1 to n dimensions may be different, but by making them all the same, the same complementary gate drive signal G Pk Can be used. The same complementary gate drive signal G PkBy using this, power expansion can be easily achieved through multiphase without increasing the size of the control circuitry. The number of phases Pk can be 2 or any other divisor of the number of phases Pk, and similarly, the complementary gate drive signal G of other dimensions Pk(1~n) You can use it.

[0019] For example, if the number of phases P1 to Pn for each of the 1st to nth dimensions is all set to 3, then, as shown in Figure 2(b), the complementary gate drive signals generated by the control circuit 20 are G1, G2, and G3 (3 signals), and the phase selection signals generated by the selection signal generation circuit 30 are also X1, X2, and X3 (3 signals).

[0020] A one-dimensional three-phase LLC converter, consisting of three circuit elements 10 each having a resonant capacitor Cr1, has a phase difference of 360° / 3 in each circuit element 10. Figure 3(a) represents these circuit elements 10 as three cubes of different densities, and the connection point where the other end (bypass terminal T1) of the resonant capacitor Cr1 is interconnected is represented by a single line passing through the three cubes.

[0021] To extend to the two-dimensional direction, one of the two resonant capacitors Cr1 and Cr2 in the circuit element 10 is connected in the one-dimensional direction, and the other resonant capacitor Cr2 is connected in the two-dimensional direction, so that the phases do not overlap at the connection points. As a result, as shown in Figure 3(b), three connection points are added in the two-dimensional direction, and a two-dimensional three-phase triple LLC converter is constructed with nine circuit elements 10 having six interconnection points. Figure 3(b) shows only the connection points in the two-dimensional direction.

[0022] Furthermore, to extend to the three-dimensional direction, the two resonant capacitors Cr1 and Cr2 of the circuit element 10, which has three resonant capacitors Cr1, Cr2, and Cr3, are connected in the one-dimensional and two-dimensional directions, respectively, and the third resonant capacitor Cr3 is interconnected in the three-dimensional direction so that the phases do not overlap at the connection points. As a result, as shown in Figure 3(c), nine interconnection points are added in the three-dimensional direction, and a three-dimensional three-phase nine-cooled LLC converter is constructed with 27 circuit elements 10 having 27 interconnection points. Figure 3(c) shows only the connection points in the three-dimensional direction.

[0023] Thus, the switching power supply 1 acts as a multiphase LLC converter at one connection point, and when comparing connection points, the multiphase LLC converters overlap, resulting in a multiple LLC converter. Therefore, the switching power supply of this embodiment can be called a multiphase multiple LLC converter.

[0024] Furthermore, if the three-dimensional three-phase nine-layer LLC converter shown in Figure 3(b) is represented as a single cube, then, as shown in Figure 4(a), the fourth dimension can be perceived in the same way as the first dimension. For the extension to the fourth dimension, the three resonant capacitors Cr1, Cr2, and Cr3 of the circuit element 10, which has four resonant capacitors Cr1, Cr2, Cr3, and Cr4, are connected in three dimensions as described above, and the fourth resonant capacitor Cr4 is connected in the fourth dimension. In this way, the four-dimensional three-phase twenty-seven-layer LLC converter is constructed with three cubes that make up the three-dimensional three-phase nine-layer LLC converter, for a total of 81 circuit elements 10. The connection points of the four-dimensional three-phase twenty-seven-layer LLC converter already contain 27 connection points in the cube of the three-dimensional three-phase nine-layer LLC converter, so there are 81 in total, and an additional 27 in the fourth dimension are added, for a total of 108 connection points. Figure 4(a) shows one of the connection points in the fourth dimension.

[0025] When extended to the 5th dimension, as shown in Figure 4(b), a 5-dimensional three-phase 81-fold LLC converter is constructed with 243 circuit elements 10 having 405 interconnection points. Figure 4(b) shows one of the connection points in the 5th dimension.

[0026] Furthermore, extending to the sixth dimension, as shown in Figure 4(c), a six-dimensional three-phase 243-layer LLC converter is constructed with 729 circuit elements 10 having 1458 interconnection points. Figure 4(c) shows one of the six-dimensional connection points.

[0027] Similarly, a 6-dimensional 3-phase 243-column LLC converter, extended to 6 dimensions, can be represented as a single cube, and the number of circuits can be increased to 7, 8, and 9 dimensions, as shown in Figure 5. Further dimensionality is achieved by adding dimensional axes to a multi-dimensional multiple LLC converter composed of 3N (where N is a natural number) dimensions, represented as a single cube. Therefore, if a 3-phase LLC converter is made n-dimensional, it becomes an n-dimensional 3-phase 3 n-1 This results in a heavy LLC converter. In this way, high power can be achieved without increasing the number of complementary gate drive signals from three phases.

[0028] Thus, the switching power supply 1 has a multidimensional, fractal structure obtained by overlapping three-dimensional orthogonal axes. Even when extended to three dimensions or more, it is not necessary to set the phase difference to 360° / Σ as in the conventional multi-phase method, depending on the total number Σ of circuit elements 10. Since it is not necessary to prepare complementary gate drive signal generation circuits that create Σ phase differences, the scaling up of the control circuits is suppressed. In particular, when the number of phases Pk in each dimension is the same, by configuring a multi-phase LLC converter with a phase difference of 360° / Pk for a certain connection point, it is possible to increase the power by increasing the number of circuits while balancing the current using circuits that generate Pk complementary gate drive signals. The switching power supply 1 of this embodiment can be configured as an integrated circuit (for example, a power supply IC or a system-on-a-chip (SoC)) in which semiconductors and magnetic components are mixed in a package of a limited size. As a simplified example, a switching power supply 1 with an output power of 1 kW (kilowatts) can be realized by connecting 10 circuit elements 10 that output 100 W of power each. A multiphase multiplex converter composed of integrated circuits may also be applied to a Micro Electro Mechanical System (MEMS).

[0029] The circuit element 10 of the switching power supply 1 has a low-potential input terminal Tin at the other end. - In addition to the resonant capacitor Cr0 connected to the first component, there are n resonant capacitors Cr1 to Crn. The other end (bypass terminal Tk) of the k-th (1 to n) resonant capacitor Crk is connected to the other end (bypass terminal Tk) of the k-th resonant capacitor Crk of another circuit element 10 so as to form a multiphase LLC converter with a phase difference of 360° / Pk using Pk circuit elements 10. In this case, the total number Σ of circuit elements 10 constituting the switching power supply 1 is expressed by equation (1) above, and the total number Σc of interconnection points by resonant capacitors Cr1 to Crn is expressed by equation (2) below.

[0030]

number

[0031] The resonant frequency ωr when all Σ of the circuit elements 10 of the switching power supply 1 are operating is as follows: It is expressed by equation (3).

[0032]

number

[0033] The resonant frequency ωr when the capacitances of resonant capacitors Cr0 to Crn are equal is as follows: It is expressed by equation (4).

[0034]

number

[0035] The total number of circuit elements 10 Σ and the number of interconnection points coincide under the condition shown in equation (5) below, derived from equations (1) and (2).

[0036]

number

[0037] In particular, when modularizing the circuit elements 10 as shown in Figure 1, the total number Σ of circuit elements 10 and the number of connection points can be limited to a 1:1 ratio.

[0038] The circuit element 10 can operate in single-phase mode under light load conditions (when the output power is low) due to the presence of the resonant capacitor Cr0. However, if single-phase operation is not required, the resonant capacitor Cr0 may be omitted. Omitting the resonant capacitor Cr0 makes it easier to balance the current between LLC converters even if the ground potentials of the LLC converters installed at different distances from each other are different.

[0039] If the resonant capacitor Cr0 is omitted, the resonant frequency ωr when all Σ of the circuit elements 10 of the switching power supply 1 are operating is expressed by the following equation (6).

[0040]

number

[0041] Furthermore, the resonant frequency ωr when the capacitances of the resonant capacitors Cr1 to Crn are equal is expressed by the following equation (7).

[0042]

number

[0043] Figure 6 shows circuit element 10a, which is a module formed by parallelizing m components other than the first switch element QH and the second switch element QL. In Figure 6, only the main circuit of circuit element 10a is shown within the solid line frame (corresponding to the module).

[0044] Circuit element 10a has one end connected to the connection point between the first switch element QH and the second switch element QL, and is a resonant reactor Lr1~Lr m It is equipped with the following: Here, m is a natural number greater than or equal to 2. Circuit element 10a is a resonant reactor Lr q (q is a natural number from 1 to m), Trans Tr q Primary winding N1 q , and n+1 resonant capacitors Cr0 q ~Crn q It comprises m resonant circuits, including [the specified element]. Circuit element 10a is a transformer Tr q Secondary winding N2 q Synchronous rectifier element SR1 rectifies and smooths the voltage. q , SR2 q NH and NH output capacitor Cout q It includes m rectifier and smoothing circuits. The rectifier and smoothing circuits can employ rectification methods such as center-tap rectification, bridge rectification, voltage doubler rectification, and Cock-Walton rectification.

[0045] Resonant capacitor Cr0 q One end is a resonant reactor Lr q , TransTr q Primary winding N1 q It is connected in series with the other end being the low-potential input terminal Tin - Connected.

[0046] Resonant capacitor Cr1 q ~Crn q Each end is a resonant reactor Lr q , TransTr q Primary winding N1 q It is connected in series with the other end to the bypass terminal T1. q ~Tn qIt is connected to the k-th (k is a natural number from 1 to n) resonant capacitor Crk q The other end (bypass terminal Tk q ) is the k-th resonant capacitor Crk of the other circuit element 10 so that Pk (where Pk is any natural number) circuit elements 10a constitute a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk. q The other end (bypass terminal Tk q It connects to ).

[0047] If single-phase operation is not required, the resonant capacitors Cr01~Cr0 of circuit element 10a m This may be omitted. Figure 7 shows the resonant capacitors Cr01~Cr0 from circuit element 10a. m This is circuit element 10b with the part omitted.

[0048] The circuit elements 10a and 10b will have their power amplified by m resonant circuits. Here, the resonant reactors Lr1~Lr m Assuming the same capacitance Lr and the current flowing through it is i, the resonant reactor Lr q The magnetic flux Φ is expressed by the following equation (8).

[0049]

number

[0050] Figures 8 and 9 show the resonant reactor Lr1~Lr m These are circuit elements 10c and 10d, which combine these into a single resonant reactor represented by the reference symbol "Lr / m". Resonant reactor Lr1~Lr m When the capacitance Lr is the same, the capacitance of the resonant reactor "Lr / m" is 1 / m of the aforementioned Lr. Circuit element 10c is the resonant reactor Lr1~Lr of circuit element 10a shown in Figure 6. m These are combined into a single resonant reactor "Lr / m". Circuit element 10d is the resonant reactor Lr1~Lr of circuit element 10b shown in Figure 7. m These are combined into a resonant reactor "Lr / m".

[0051] The current flowing through the resonant reactor "Lr / m" is the current flowing through the resonant reactor Lr1~Lr m Since it is the sum of the currents i flowing through it, it is mi. Therefore, the magnetic flux Φ of the resonant reactor "Lr / m" is expressed by the following equation (9), and is the same as the magnetic flux Φ obtained by equation (8).

[0052]

number

[0053] In other words, the resonant reactor at the unit level of circuit element 10c and circuit element 10d is the same as the resonant reactor Lr of circuit element 10. Therefore, in a switching power supply 1 composed of circuit element 10c, the resonant frequency ωr when all Σ circuit elements 10c are operating is the same as that given by equations (3) and (4) above. In a switching power supply 1 composed of circuit element 10d, the resonant frequency ωr when all Σ circuit elements 10d are operating is the same as that given by equations (6) and (7) above.

[0054] Thus, the m resonant reactors Lr1~Lr of the circuit elements 10a and 10b m This is a resonant capacitor Cr01~Cr0 m Regardless of their presence or absence, the resonant reactors can be consolidated into a single resonant reactor "Lr / m", as in circuit elements 10c and 10d. The capacitance of the resonant reactors "Lr / m" of circuit elements 10c and 10d can be 1 / m of the capacitance of the resonant reactor Lr of circuit element 10. Therefore, the switching power supply unit 1 composed of circuit elements 10c and 10d can have a total size of resonant reactors that is 1 / m and a total weight that is 1 / m compared to the switching power supply unit 1 of the same number of dimensions composed of circuit element 10. In other words, when increasing power, the switching power supply unit 1 can reduce the size of the resonant reactor Lr as it is parallelized, and the resonant capacitor Cr can be reduced as it becomes more multidimensional. When the power is specified, the switching power supply unit 1 can reduce the size of the transformers Tr1~T as it is parallelized. m It can be made smaller, suitable for integration, and allows for smaller component sizes.

[0055] Figure 10 shows a two-dimensional three-phase triple LLC converter where each resonant circuit of circuit elements 10a to 10d is represented by a cube, and cubes with different phases are represented by three different densities, with m being the number of parallelized elements. Referring to Figure 10, it can be seen that parallelizing the resonant circuits in circuit elements 10a to 10d is equivalent to increasing the number of dimensions by one.

[0056] As described above, this embodiment includes multiple (Σ) half-bridge LLC converters, each with resonant circuits arranged in parallel, as circuit elements 10a and 10b. Circuit elements 10a and 10b each include a first switch element QH and a second switch element QL connected in series between the positive and negative terminals of a DC power supply Vin, a resonant reactor Lr with one end connected to the connection point between the first switch element QH and the second switch element QL, a primary winding N1 of a transformer Tr, and m parallel resonant circuits (m is a natural number of 2 or more) each containing n (n is a natural number of 2 or more) first-order resonant capacitors (resonant capacitor Cr1) to nth-order resonant capacitors (resonant capacitor Crn). The resonant capacitor Crk of the q-th (q is a natural number of 1 to m) parallel resonant circuit. q (where k is a natural number from 1 to n) is a resonant reactor Lr at one end. q , TransTr q Primary winding N1 q It is connected in series with the q-th resonant circuit in parallel. q The other end constitutes a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk, with the other end comprising Pk circuit elements (where Pk is any natural number), and the resonant capacitor Crk of the q-th resonant circuit parallelized in the other circuit elements 10a and 10b. q Connected. With this configuration, this embodiment can reduce the number of complementary gate drive signals to less than the total number Σ of circuit elements 10a and 10b, without increasing the number of complementary gate drive signals. This embodiment can achieve high power output of circuit elements 10a and 10b by parallelizing the resonant circuits. This embodiment can achieve high power output by increasing the total number Σ of circuit elements 10 and balancing the current between each circuit element 10.

[0057] Furthermore, the circuit elements 10c and 10d of this embodiment include multiple (Σ) half-bridge LLC converters as circuit elements 10a and 10b, in which the resonant circuits (circuit portions excluding the resonant reactor "Lr / m") are connected in parallel. The circuit elements 10c and 10d have a first switch element QH and a second switch element QL connected in series between the positive and negative terminals of a DC power supply Vin, a resonant reactor "Lr / m" with one end connected to the connection point between the first switch element QH and the second switch element QL, and the primary winding N1 of a transformer Tr connected to the other end of the resonant reactor "Lr / m", and m parallel resonant circuits (m is a natural number of 2 or more) each containing n (n is a natural number of 2 or more) first-order resonant capacitors (resonant capacitor Cr1) to the nth-order resonant capacitor (resonant capacitor Crn). The resonant capacitor Crk of the q-th (q is a natural number of 1 to m) resonant circuit in the parallel resonant circuit. q (where k is a natural number from 1 to n) is a resonant reactor Lr at one end. q , TransTr q Primary winding N1 q It is connected in series with the q-th resonant circuit in parallel. q The other end constitutes a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk, with the other end comprising Pk circuit elements (where Pk is any natural number), and the resonant capacitor Crk of the q-th resonant circuit parallelized in the other circuit elements 10a and 10b. q Connected. With this configuration, the switching power supply unit 1 composed of circuit elements 10c and 10d can reduce the total size of the resonant reactor to 1 / m and the total weight to 1 / m compared to the switching power supply unit 1 of the same number of dimensions composed of circuit element 10. In other words, when increasing power, the switching power supply unit 1 can reduce the size of the resonant reactor Lr as it is parallelized, and reduce the size of the resonant capacitor Cr as it becomes more multidimensional.

[0058] Furthermore, according to this embodiment, the total number Σ of circuit elements 10a to 10d is the product of the number of phases included in each dimension (Σ = P1 × P2 × ... × Pn). This configuration allows for an exponential increase in the total number Σ of circuit elements 0a to 10d by increasing the dimension, thus enabling support for higher power requirements.

[0059] Although the present invention has been described above with reference to specific embodiments, it goes without saying that these embodiments are merely examples and can be modified and implemented without departing from the spirit of the present invention. In the above embodiment, a resonant reactor Lr is physically provided for each circuit element 10, but alternatively, the resonant reactor Lr may utilize the leakage inductance of the transformer. [Explanation of symbols]

[0060] 1. Switching power supply 10, 10a, 10b, 10c, 10d Circuit elements (half-bridge LLC converter) 20 Control circuits 30. Selected signal generation circuit 41 Phase Select Circuit 42-dimensional selection circuit Cin input capacitor Cout output capacitor Cr0~Crn Resonant Capacitor Lr resonant reactor N1 Primary winding N2 secondary winding QH First Switch Element QL Second Switch Element SR1, SR2 Synchronous Rectifiers Tr transformer T1~Tn Bypass Terminals Tin + High-potential input terminal Tin - Low-voltage input terminal VOUT + High-potential output terminal VOUT - Low-voltage output terminal Vin DC power supply

Claims

1. A first switch element and a second switch element are connected in series to both ends of a DC power supply, The circuit comprises multiple half-bridge LLC converters, each having a resonant reactor with one end connected to the connection point between the first and second switching elements, a primary winding of a transformer, and m parallel resonant circuits (m being a natural number of 2 or more) each containing n (n being a natural number of 2 or more) first-order to n-th-order resonant capacitors. A switching power supply device in which the k-th resonant capacitor (k is a natural number from 1 to n) of the parallelized q-th (q is a natural number from 1 to m) resonant circuit is connected at one end in series with the resonant reactor and the primary winding of the transformer, and the other end is connected to the k-th resonant capacitor of the parallelized q-th resonant circuit in other circuit elements so as to constitute a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk using Pk (Pk is an arbitrary natural number) circuit elements.

2. A first switch element and a second switch element are connected in series to both ends of a DC power supply, A resonant reactor, with one end connected to the connection point between the first and second switching elements, The circuit comprises multiple half-bridge LLC converters, each having a primary winding of a transformer connected to the other end of the resonant reactor, and m parallel resonant circuits (m being a natural number of 2 or more) each containing n (n being a natural number of 2 or more) first-order to n-th-order resonant capacitors. A switching power supply device in which the k-th resonant capacitor (k is a natural number from 1 to n) of the parallelized q-th (q is a natural number from 1 to m) resonant circuit is connected at one end in series with the resonant reactor and the primary winding of the transformer, and the other end is connected to the k-th resonant capacitor of the parallelized q-th resonant circuit in other circuit elements so as to constitute a k-dimensional multiphase LLC converter with a phase difference of 360° / Pk using Pk (Pk is an arbitrary natural number) circuit elements.

3. The switching power supply device according to claim 1 or claim 2, wherein the total number of circuit elements is the product of the number of phases included in each dimension.

4. The switching power supply device according to claim 3, wherein the total number of resonant circuits is the product of the number of phases included in each dimension and the number of parallel circuits m (where m is a natural number of 2 or more).

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