DC / DC power converters

Abstract

The present disclosure is a DC / DC power converter, comprising: a high-voltage side, comprising a high-voltage positive electrode and a high-voltage negative electrode; a low-voltage side, comprising a low-voltage positive electrode and a low-voltage negative electrode, wherein the low-voltage negative electrode is electrically connected to the high-voltage negative electrode; a high-voltage side capacitor, wherein a first end of the high-voltage side capacitor is electrically connected to the high-voltage positive electrode, and a second end of the high-voltage side capacitor is electrically connected to the low-voltage positive electrode; and a power conversion circuit, electrically connected between the high-voltage side and the low-voltage side, and comprising at least one switch and at least one magnetic component.

Description

Technical Field

[0001] The present invention discloses a power converter, and more particularly relates to a DC / DC power converter. Background Art

[0002] In existing applications of non-isolated, high-current DC / DC power converters, a resonant-type scalable-duty-cycle circuit topology may be employed, wherein the resonant-type scalable-duty-cycle DC / DC power converter may further include symmetrical and asymmetrical power conversion circuits.

[0003] The power conversion circuit of a conventional DC / DC power converter, whether symmetrical or asymmetrical, typically includes multiple switches. These switches can be divided into two groups, each conducting 180 degrees out of phase. Furthermore, a conventional DC / DC power converter includes magnetic components and two capacitors. One capacitor is connected across the input of the DC / DC power converter to form a high-voltage side capacitor, and the other capacitor is connected across the output of the DC / DC power converter to form a low-voltage side capacitor.

[0004] However, when the multiple switches of a conventional DC / DC power converter are turned on 180 degrees out of phase, the other electronic components and magnetic components within the conventional DC / DC power converter, along with the turned-on switches, form multiple AC circuits. Furthermore, the AC current flowing in at least one of these multiple AC circuits flows through both the high-side capacitor and the low-side capacitor. This results in significant power loss in the Equivalent Series Resistance (ESR) formed by the low-side and high-side capacitors.

[0005] Furthermore, due to space limitations, traditional DC / DC power converters typically use multilayer ceramic capacitors (MLCCs) for the high-voltage side capacitors. However, since MLCCs have the characteristic that their equivalent capacitance decreases as the DC voltage across the capacitor increases, once the voltage across the high-voltage side capacitor is high, the DC voltage bias of the high-voltage side capacitor increases, causing the equivalent capacitance of the high-voltage side capacitor to decrease.

[0006] Therefore, developing a DC / DC power converter that overcomes the above-mentioned shortcomings is an urgent need. Summary of the Invention

[0007] The present disclosure aims to provide a DC / DC power converter that can reduce the number of capacitors through which AC current flows, thereby reducing power loss due to parasitic resistance, and can reduce the DC bias of the high-voltage side capacitor, thereby increasing the equivalent capacitance value of the high-voltage side capacitor.

[0008] To achieve the above-mentioned objectives, a broader embodiment of the present disclosure is to provide a DC / DC power converter, comprising: a high-voltage side, comprising a high-voltage positive electrode and a high-voltage negative electrode; a low-voltage side, comprising a low-voltage positive electrode and a low-voltage negative electrode, wherein the low-voltage negative electrode is electrically connected to the high-voltage negative electrode; a high-voltage side capacitor, wherein a first end of the high-voltage side capacitor is electrically connected to the high-voltage positive electrode, and a second end of the high-voltage side capacitor is electrically connected to the low-voltage positive electrode; and a power conversion circuit, electrically connected between the high-voltage side and the low-voltage side, and comprising at least one switch and at least one magnetic component. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of the circuit principle of the DC / DC power converter disclosed in the present invention;

[0010] Figure 2A Schematic diagram of the circuit structure of a DC / DC power converter according to a first preferred embodiment of the present disclosure;

[0011] Figure 2B for Figure 2A Operation timing diagram of switches in the power conversion circuit shown;

[0012] Figure 2C for Figure 2A The power conversion circuit shown in Figure 2B The AC circuit diagram generated at time t0-t1 is shown;

[0013] Figure 2D for Figure 2A Schematic diagram of an AC circuit generated by the power conversion circuit shown in FIG2b at time t2-t3;

[0014] Figure 3 Schematic diagram of the circuit structure of a DC / DC power converter according to a second preferred embodiment of the present disclosure;

[0015] Figure 4 Schematic diagram of the circuit structure of a DC / DC power converter according to a third preferred embodiment of the present disclosure;

[0016] Figure 5 Schematic diagram of the circuit structure of a DC / DC power converter according to the fourth preferred embodiment of the present disclosure.

[0017] The following are the descriptions of the reference numerals:

[0018] 1, 2: DC / DC power converter

[0019] Vin: input voltage

[0020] Vo: output voltage

[0021] C1: High-voltage side capacitor

[0022] C2: low voltage side capacitor

[0023] 10, 20, 30, 40, 50: Power conversion circuit

[0024] V1+: high voltage positive electrode

[0025] V1-: high voltage negative electrode

[0026] V2+: low voltage positive electrode

[0027] V2-: low voltage negative electrode

[0028] 11: First switch group

[0029] 12: Second switch group

[0030] 13, 23, 33, 41: Magnetic components

[0031] t1~t4: time

[0032] S1A, S1a, S1: First switch

[0033] S2B, S1b, S2: Second switch

[0034] S2C, S2c: The third switch

[0035] S2A, S1c: fourth switch

[0036] S1B: Fifth switch

[0037] S1C: Sixth switch

[0038] Cr1: First flying capacitor

[0039] Cr2: Second flying capacitor

[0040] T21, T22: transformer windings

[0041] Lr1, Lr2, L0: inductance DETAILED DESCRIPTION

[0042] Some typical embodiments that embody the features and advantages of the present disclosure will be described in detail in the following description. It should be understood that the present disclosure can have various variations in different embodiments without departing from the scope of the present disclosure, and the descriptions and illustrations therein are essentially for illustrative purposes and are not intended to limit the present disclosure.

[0043] Figure 1The following is a schematic diagram of the circuit principle of the DC / DC power converter disclosed herein. As shown in the figure, the DC / DC power converter 1 disclosed herein receives an input voltage Vin and converts the input voltage Vin into an output voltage Vo. The DC / DC power converter 1 includes a high-voltage side, a low-voltage side, a high-voltage side capacitor C1, a low-voltage side capacitor C2, and a power conversion circuit 10. The high-voltage side includes a high-voltage positive electrode V1+ and a high-voltage negative electrode V1-. The DC / DC power converter 1 receives the input voltage Vin via the high-voltage positive electrode V1+ and the high-voltage negative electrode V1-. The low-voltage side includes a low-voltage positive electrode V2+ and a low-voltage negative electrode V2-. The DC / DC power converter 1 outputs the output voltage Vo via the low-voltage positive electrode V2+ and the low-voltage negative electrode V2-. In addition, the low-voltage negative electrode V2- is electrically connected to the high-voltage negative electrode V1-, so the DC / DC power converter 1 is a non-isolated DC / DC power converter.

[0044] The first end of the high-voltage side capacitor C1 is electrically connected to the high-voltage positive electrode V1+ on the high-voltage side, and the second end of the high-voltage side capacitor C1 is electrically connected to the low-voltage positive electrode V2+ on the low-voltage side. The first end of the low-voltage side capacitor C2 is electrically connected to the low-voltage positive electrode V2+ on the low-voltage side, and the second end of the low-voltage side capacitor C2 is electrically connected to the low-voltage negative electrode V2- on the low-voltage side. The high-voltage side capacitor C1 and the low-voltage side capacitor C2 are connected in series to filter voltage ripple on the high-voltage side, and the low-voltage side capacitor C2 is used to filter voltage ripple on the low-voltage side. In some embodiments, the high-voltage side capacitor C1 may be, but is not limited to, composed of a multilayer ceramic capacitor.

[0045] The power conversion circuit 10 is electrically connected between the high-voltage side and the low-voltage side, and includes a first switch group 11, a second switch group 12, and at least one magnetic component 13. The first switch group 11 and the second switch group 12 are electrically connected to the high-voltage positive electrode V1+ and the high-voltage negative electrode V1- of the high-voltage side, respectively, and each includes at least one switch, wherein the at least one switch of the first switch group 11 and the at least one switch of the second switch group 12 are further turned on 180 degrees out of phase. The magnetic component 13 may include at least one magnetic component constituting a transformer and / or an inductor, and is electrically connected to the first switch group 11 and the second switch group 12. The power conversion circuit 10 converts the input voltage Vin into the output voltage Vo through the switching operation of the first switch group 11 and the second switch group 12 in conjunction with the magnetic component 13.

[0046] In some embodiments, the power conversion circuit 10 may adopt a resonant type circuit topology with scalable duty cycle. Under the condition of the resonant type circuit topology with scalable duty cycle, the power conversion circuit 10 may also be symmetrical or asymmetrical, but is not limited thereto.

[0047] In the present disclosure, since the first end of the high-voltage side capacitor C1 is electrically connected to the high-voltage positive electrode V1+ on the high-voltage side, and the second end of the high-voltage side capacitor C1 is electrically connected to the low-voltage positive electrode V2+ on the low-voltage side, the paths of multiple AC circuits within the DC / DC power converter 1 can be changed, thereby causing the AC current in each AC circuit to flow only through one of the high-voltage side capacitor C1 and the low-voltage side capacitor C2. In this way, the number of capacitors in the path through which the AC current flows can be reduced, shortening the AC current loop, thereby reducing power loss caused by parasitic resistance. Furthermore, compared to conventional DC / DC power converters in which the high-voltage side capacitors are electrically connected between the high-voltage positive and high-voltage negative electrodes, such that the voltage across the high-voltage side capacitors is equal to the input voltage, the DC voltage across the high-voltage side capacitor C1 of the DC / DC power converter 1 disclosed herein is the difference between the input voltage Vin and the output voltage Vo, i.e., the DC voltage across the high-voltage side capacitor C1 is Vin-Vo. Therefore, the DC voltage across the high-voltage side capacitor C1 is reduced compared to the input voltage Vin. This reduces the DC bias of the high-voltage side capacitor C1, allowing a capacitor with a large equivalent capacitance value to be selected as the high-voltage side capacitor C1. In this embodiment, the high-voltage side capacitor C1 and the low-voltage side capacitor C2 are connected in series to filter out voltage ripple on the high-voltage side, while the low-voltage side capacitor C2 is used to filter out voltage ripple on the low-voltage side.

[0048] The following will be based on Figure 1 The circuit principle of the DC / DC power converter 1 is shown to further illustrate various possible implementations of the DC / DC power converter. The multiple implementations described below are only examples and are not limited thereto. In other words, all non-isolated DC / DC power converters are applicable to the technical solutions disclosed above. Figure 2A Schematic diagram of the circuit structure of the DC / DC power converter of the first preferred embodiment of the present disclosure. Figure 2B for Figure 2A The operating timing diagram of the switch in the power conversion circuit is shown. Figure 2C for Figure 2A The power conversion circuit shown in Figure 2B The AC circuit diagram generated at time t0-t1 is shown. Figure 2D for Figure 2A The power conversion circuit shown in Figure 2B The AC circuit diagram generated at time t2-t3 is shown. The DC / DC power converter 2 of this embodiment is a non-isolated DC / DC power converter and includes a high-voltage side, a low-voltage side, a high-voltage side capacitor C1, a low-voltage side capacitor C2, and a power conversion circuit 20. The connection relationship and component operation of the high-voltage side, the low-voltage side, the high-voltage side capacitor C1, and the low-voltage side capacitor C2 are similar. Figure 1 The connection relationship between the high-voltage side, the low-voltage side, the high-voltage side capacitor C1 and the low-voltage side capacitor C2 of the DC / DC power converter 1 and the operation of the components are not described in detail here.

[0049] The power conversion circuit 20 has a symmetrical circuit topology and includes a first flying capacitor Cr1, a second flying capacitor Cr2, a first switch group, a second switch group, and a magnetic component 23. The first switch group includes a first switch S1A, a second switch S2B, and a third switch S2C. The second switch group has a similar structure to the first switch group, namely, includes a fourth switch S2A, a fifth switch S1B, and a sixth switch S1C. A first end of the first switch S1A is electrically connected to a high-voltage positive electrode V1+. A second end of the first switch S1A is electrically connected to a first end of a fifth switch S1B. A second end of the fifth switch S1B is electrically connected to a first end of a sixth switch S1C. A second end of the sixth switch S1C is electrically connected to a high-voltage negative electrode V1-. A first end of the fourth switch S2A is electrically connected to the high-voltage positive electrode V1+ and is electrically connected in parallel with the first switch S1A. A second end of the fourth switch S2A is electrically connected to a first end of the second switch S2B. A second end of the second switch S2B is electrically connected to a first end of the third switch S2C. A second end of the third switch S2C is electrically connected to a high-voltage negative electrode V1-. One end of the first flying capacitor Cr1 is electrically connected to the second end of the first switch S1A, and the other end is electrically connected between the second end of the second switch S2B and the first end of the third switch S2C. One end of the second flying capacitor Cr2 is electrically connected to the second end of the fourth switch S2A, and the other end is electrically connected between the second end of the fifth switch S1B and the first end of the sixth switch S1C. Furthermore, the first switch S1A, the second switch S2B, the third switch S2C, the fourth switch S2A, the fifth switch S1B, and the sixth switch S1C are periodically switched within a switching cycle.

[0050] In the embodiment of the present disclosure, the magnetic component 23 may include a transformer and two inductors Lr1 and Lr2, wherein the transformer includes two transformer windings T21 and T22, and the inductors Lr1 and Lr2 may be the leakage inductance of the transformer and / or the parasitic inductance of the circuit, or may be an external inductor independent of the transformer, but is not limited thereto. Figure 2A The second end of transformer winding T21 and the second end of transformer winding T22 are opposite-name terminals and are both electrically connected to the low-voltage positive terminal V2+. The first end of transformer winding T21 is electrically connected to the first end of inductor Lr1, and the first end of transformer winding T22 is electrically connected to the first end of inductor Lr2. The second end of inductor Lr1 is electrically connected to the second end of second switch S2B and the first end of third switch S2C. The second end of inductor Lr2 is electrically connected to the second end of fifth switch S1B and the first end of sixth switch S1C. In another embodiment, magnetic component 23 may include only two inductors, Lr1 and Lr2.

[0051] In addition, the switching state of the first switch S1A, the switching state of the second switch S2B and the switching state of the sixth switch S1C are the same, and the switching state of the fourth switch S2A, the switching state of the fifth switch S1B and the switching state of the third switch S2C are the same. Figure 2B As shown, in a switching cycle of the time period t0-t4, the first switch S1A, the second switch S2B and the sixth switch S1C are in the on state during the time period t0-t1 and in the off state during the time period t2-t3; while the fourth switch S2A, the fifth switch S1B and the third switch S2C are in the on state during the time period t2-t3 and in the off state during the time period t0-t1. The time period t0-t4 is the switching cycle Ts of the power conversion circuit 20, and the time periods t1-t2 and t3-t4 are the dead time. In addition, the control signal of the first switch S1A and the control signal of the fourth switch S2A are 180 degrees out of phase, and the on time Ton of the first switch S1A is 0. (S1A) and the on-time Ton of the fourth switch S2A (S2A) If the dead time is not considered, the duty cycle of each switch is close to 50%.

[0052] Please refer to Figure 2C In the time period t0-t1, when the first switch S1A, the second switch S2B and the sixth switch S1C are turned on at the same time, there are three AC current loops in the DC / DC power converter 2. The first AC loop ( Figure 2C The circuit marked as A) is composed of the high-voltage side capacitor C1, the first switch S1A, the first flying capacitor Cr1, the inductor Lr1 and the transformer winding T21. The second AC circuit ( Figure 2C The circuit marked as B) is composed of the sixth switch S1C, the second flying capacitor Cr2, the second switch S2B, the inductor Lr1, the transformer winding T21 and the low-voltage side capacitor C2. The third AC circuit ( Figure 2C The circuit marked with C) is composed of the sixth switch S1C, the inductor Lr2, the transformer winding T22 and the low-voltage side capacitor C2.

[0053] See Figure 2D In the time period t2-t3, when the fourth switch S2A, the fifth switch S1B and the third switch S2C are turned on at the same time, there are also three AC current loops in the DC / DC power converter 2. The first AC loop ( Figure 2D The circuit marked as D) is composed of the high-voltage side capacitor C1, the fourth switch S2A, the second flying capacitor Cr2, the inductor Lr2 and the transformer winding T22. The second AC circuit ( Figure 2DThe circuit marked as E) is composed of the third switch S2C, the first flying capacitor Cr1, the fifth switch S1B, the inductor Lr2, the transformer winding T22 and the low-voltage side capacitor C2. The third AC circuit ( Figure 2D The circuit marked with F) is composed of the third switch S2C, the inductor Lr1, the transformer winding T21 and the low-voltage side capacitor C2.

[0054] according to Figure 2C and Figure 2D As can be seen from the AC circuit, compared to conventional DC / DC power converters in which the AC current flowing in at least one AC circuit simultaneously flows through both the high-voltage side capacitor and the low-voltage side capacitor, the DC / DC power converter 2 of this embodiment electrically connects one end of the high-voltage side capacitor to the high-voltage positive electrode V1+ and the other end to the low-voltage positive electrode V2+. This allows the AC current in the first AC circuit to flow only through the high-voltage side capacitor C1 and not through the low-voltage side capacitor C2 during any time interval. This reduces the AC current flowing into the low-voltage side capacitor C2, thereby reducing the power loss caused by the parasitic resistance on the capacitor C2. Furthermore, the AC current in other AC current circuits does not simultaneously flow through both the high-voltage side capacitor C1 and the low-voltage side capacitor C2, thereby reducing the parasitic resistance in the AC current circuit. As a result, the power loss of the DC / DC power converter 2 of this embodiment can be reduced. In addition, compared to a conventional DC / DC power converter in which the voltage across the high-side capacitor is equal to the input voltage, the voltage across the high-side capacitor C1 of the DC / DC power converter 2 of this embodiment is equal to the difference between the input voltage Vin and the output voltage Vo. Therefore, the DC voltage offset of the high-side capacitor C1 is reduced, and a capacitor with a larger capacitance value can be selected as the high-side capacitor C1.

[0055] In the above embodiment, during the time period t0-t1, when the first switch S1A, the second switch S2B, and the sixth switch S1C are simultaneously turned on, the first AC circuit of the DC / DC power converter 2 includes, in addition to the first flying capacitor Cr1, the inductor Lr1, and the high-side capacitor C1, an equivalent capacitor C2' and an equivalent inductor Lr2'. The multiple equivalent capacitors C2' and equivalent inductors Lr2' are obtained by equivalently converting the low-side capacitor C2 and the inductor Lr2 to one side of the transformer (i.e., the side where the inductor Lr1 and the transformer winding T1 are located). In the second AC circuit of the DC / DC power converter 2, in addition to the second flying capacitor Cr2, the inductor Lr1, and the low-side capacitor C2, the equivalent capacitor C2' and equivalent inductor Lr2' are obtained by equivalently converting the low-side capacitor C2 and the inductor Lr2 to the first side of the transformer. Similarly, during the time period t2-t3, when the fourth switch S2A, the fifth switch S1B, and the third switch S2C are simultaneously turned on, the first AC circuit of the DC / DC power converter 2 includes, in addition to the second flying capacitor Cr1, the inductor Lr2, and the high-side capacitor C1, an equivalent capacitance C2′ and an equivalent inductance Lr1′ obtained by equivalently connecting the low-voltage side capacitor C2 and the inductor Lr1 to one side of the transformer (i.e., the side where the inductor Lr2 and the transformer winding T2 are located); and the second AC circuit of the DC / DC power converter 2 includes, in addition to the first flying capacitor Cr1, the inductor Lr2, and the low-voltage side capacitor C2, an equivalent capacitance C2′ and an equivalent inductance Lr2′ obtained by equivalently connecting the low-voltage side capacitor C2 and the inductor Lr2 to the first side of the transformer. In this embodiment, regardless of the conduction interval of the DC / DC power converter 2 of this embodiment, the simplified mathematical formula of the resonant frequency in the first AC circuit is 1 / (2·π·sqrt((Cr1 / / (C2 / 3) / / C1)*(2·Lr))), and the simplified mathematical formula of the resonant frequency in the second AC circuit is 1 / (2·π·sqrt((Cr1 / / (C2 / 3) / / (C2 / 3))·(2·Lr))). Therefore, in this embodiment, the capacitance values of the high-voltage side capacitor C1 and the low-voltage side capacitor C2 are selected to satisfy C1=C2 / 3, thereby achieving equal equivalent capacitance values in the first AC circuit and the second AC circuit, thereby making the resonant frequencies of the two AC circuits the same, the currents of the two resonant circuits can simultaneously satisfy a sine waveform, and the switching devices of the two resonant circuits can be simultaneously turned off with zero current.

[0056] Figure 3This is a schematic diagram of the circuit structure of a DC / DC power converter according to a second preferred embodiment of the present disclosure. In some embodiments, the DC / DC power converter 2 is a non-isolated DC / DC power converter. The power conversion circuit 30 of the DC / DC power converter 2 can be modified to an asymmetric circuit topology and includes a first switch group, a second switch group, a first flying capacitor Cr1, and a magnetic component 33. The first switch group includes a first switch S1a and a third switch S2c electrically connected in series. The second switch group includes a second switch S1b and a fourth switch S1c electrically connected in series. The first switch S1a, the second switch S1b, the third switch S2c, and the fourth switch S1c are periodically switched within a switching cycle. Furthermore, the first end of the first switch S1a is electrically connected to the high-voltage positive electrode V1+, the second end of the first switch S1a is electrically connected to the first end of the second switch S1b, the second end of the second switch S1b is electrically connected to the first end of the fourth switch S1c, and the second end of the third switch S2c and the second end of the fourth switch S1c are electrically connected and electrically connected to the high-voltage negative electrode V1-. One end of the first flying capacitor Cr1 is electrically connected to the second end of the first switch S1a, and the other end thereof is electrically connected between the first end of the second switch S1b and the first end of the third switch S2c. In another embodiment, the magnetic component 23 may include only two inductors Lr1 and Lr2.

[0057] In addition, the switching state of the first switch S1a is the same as the switching state of the fourth switch S1c, the switching state of the second switch S1b is the same as the switching state of the third switch S2c, and the control signal of the first switch S1a and the control signal of the second switch S1b are 180 degrees out of phase, and the on-time of the first switch S1a and the on-time of the second switch S1b are both less than or equal to half of the switching period Ts and greater than or equal to 0.4 times the switching period Ts.

[0058] Magnetic assembly 33 is similar to magnetic assembly 23 and includes a transformer (including two transformer windings T21 and T22) and two inductors Lr1 and Lr2. Inductors Lr1 and Lr2 can be, but are not limited to, the transformer's leakage inductance and / or parasitic inductance of the circuit, or can be external inductors independent of the transformer. The second ends of the two transformer windings T21 and T22 are opposite-terminal terminals and electrically connected to the low-voltage positive terminal V2+. The first end of the transformer winding T21 is electrically connected to the first end of the inductor Lr1, and the first end of the transformer winding T22 is electrically connected to the first end of the inductor Lr2. The second end of the inductor Lr1 is electrically connected to the first end of the third switch S2c, and the second end of the inductor Lr2 is electrically connected to the second end of the second switch S1b and the first end of the fourth switch S1c.

[0059] In this embodiment, the DC / DC power converter 2 of this embodiment can achieve effects similar to those of the DC / DC power converter 2 of the first embodiment. Specifically, the DC / DC power converter 2 of this embodiment electrically connects one end of the high-voltage side capacitor C1 to the high-voltage positive electrode V1+ and the other end to the low-voltage positive electrode V2+, so that within any conduction interval, the current in any AC circuit flows only through one of the high-voltage side capacitor C1 and the low-voltage side capacitor C2. Therefore, the power loss of the DC / DC power converter 2 of this embodiment can be reduced. In addition, the DC voltage offset of the high-voltage side capacitor C1 of the DC / DC power converter 2 of this embodiment is reduced, thereby increasing the equivalent capacitance value of the high-voltage side capacitor C1. Similarly, the high-voltage side capacitor C1 and the low-voltage side capacitor C2 are connected in series to filter out voltage ripple on the high-voltage side, while the low-voltage side capacitor C2 is used to filter out voltage ripple on the low-voltage side. Other principles are not further described here.

[0060] Figure 4 This is a schematic diagram of the circuit structure of a DC / DC power converter according to the third preferred embodiment of the present disclosure. In some embodiments, the DC / DC power converter 2 is a non-isolated DC / DC power converter. The power conversion circuit 40 of the DC / DC power converter 2 can be a hard-switching buck circuit topology and includes a first switch group, a second switch group, and a magnetic component 41. The first switch group includes a first switch S1, and the second switch group includes a second switch S2. The first end of the first switch S1 is electrically connected to the high-voltage positive electrode V1+, the second end of the first switch S1 is electrically connected to the first end of the second switch S2, and the second end of the second switch S2 is electrically connected to the high-voltage negative electrode V1-. The magnetic component 41 includes an inductor L0, the first end of the inductor L0 is electrically connected between the second end of the first switch S1 and the first end of the second switch S2, and the second end of the inductor L0 is electrically connected to the low-voltage positive electrode V2+.

[0061] In this embodiment, the DC / DC power converter 2 has two AC circuits: a first AC circuit formed by an inductor Lo and a high-voltage side capacitor C1, and a second AC circuit formed by an inductor Lo and a low-voltage side capacitor C2. Similar to the technical effects achieved by the aforementioned embodiments, the DC / DC power converter 2 of this embodiment electrically connects one end of the high-voltage side capacitor C1 to the high-voltage positive electrode V1+ and the other end to the low-voltage positive electrode V2+. This ensures that, within any conduction interval, the current in each AC circuit flows only through either the high-voltage side capacitor C1 or the low-voltage side capacitor C2. Consequently, the power loss of the DC / DC power converter 2 of this embodiment is reduced. Furthermore, the DC voltage offset of the high-voltage side capacitor C1 of the DC / DC power converter 2 of this embodiment is reduced, thereby increasing the equivalent capacitance of the high-voltage side capacitor C1. The principles underlying this are not further elaborated here.

[0062] Figure 5Schematic diagram of the circuit structure of the DC / DC power converter of the fourth preferred embodiment of the present disclosure. In some embodiments, the DC / DC power converter 2 is a non-isolated DC / DC power converter, and the power conversion circuit 50 of the DC / DC power converter 2 can be a symmetrical scalable duty cycle hard-switching buck circuit topology, and its circuit structure is similar to Figure 2A The DC / DC power converter 2 shown here is only labeled with the same symbols to represent that the features and operations of the components are similar and no further description is given. Figure 2A The magnetic component 23 of the DC / DC power converter 2 shown includes two transformer windings T21 and T22 and two inductors Lr1 and Lr2. In this embodiment, the DC / DC power converter 2 only includes two inductors Lr1 and Lr2. Therefore, the first end of inductor Lr1 and the first end of inductor Lr2 are respectively electrically connected to the low-voltage positive terminal V2+. In another embodiment, the two inductors Lr1 and Lr2 can form a coupled inductor.

[0063] When the first switch S1A, the second switch S2B, and the sixth switch S1C are simultaneously turned on, there are three AC current loops in the DC / DC power converter 2. The first AC loop is formed by the high-voltage side capacitor C1, the first switch S1A, the first flying capacitor Cr1, and the inductor Lr1. The second AC loop is formed by the sixth switch S1C, the second flying capacitor Cr2, the second switch S2B, the inductor Lr1, and the low-voltage side capacitor C2. The third AC loop is formed by the sixth switch S1C, the inductor Lr2, and the low-voltage side capacitor C2. When the fourth switch S2A, the fifth switch S1B, and the third switch S2C are turned on simultaneously, three AC current loops are also formed in the DC / DC power converter 2. The first AC loop is formed by the high-voltage side capacitor C1, the fourth switch S2A, the second flying capacitor Cr2, and the inductor Lr2. The second AC loop is formed by the third switch S2C, the first flying capacitor Cr1, the fifth switch S1B, the transformer winding T22, and the low-voltage side capacitor C2. The third AC loop is formed by the third switch S2C, the inductor Lr1, and the low-voltage side capacitor C2. Similar to the technical effects achieved by the aforementioned embodiments, the DC / DC power converter 2 of this embodiment electrically connects one end of the high-voltage side capacitor C1 to the high-voltage positive electrode V1+ and the other end to the low-voltage positive electrode V2+. This ensures that, within any conduction interval, the current in any AC circuit flows only through one of the high-voltage side capacitor C1 and the low-voltage side capacitor C2. Consequently, the power loss of the DC / DC power converter 2 of this embodiment is reduced. Furthermore, the DC voltage offset of the high-voltage side capacitor C1 of the DC / DC power converter 2 of this embodiment is reduced, thereby increasing the equivalent capacitance of the high-voltage side capacitor C1. The principles behind this are not further elaborated here.

[0064] like Figure 2A 、 Figure 3 、 Figure 4 as well as Figure 5 The DC / DC power converter shown is used in reverse, that is, when the low-voltage side is the voltage input side and the high-voltage side is the voltage output side, one end of the high-voltage side capacitor C1 is electrically connected to the high-voltage positive electrode V1+, and the other end is electrically connected to the low-voltage positive electrode V2+. This can also reduce the power loss of the DC / DC power converter and reduce the DC voltage bias of the high-voltage side capacitor C1, thereby increasing the equivalent capacitance value of the high-voltage side capacitor C1.

[0065] In summary, the present disclosure provides a DC / DC power converter, wherein the first end of the high-voltage side capacitor of the DC / DC power converter is electrically connected to the high-voltage positive electrode of the high-voltage side, and the second end of the high-voltage side capacitor is electrically connected to the low-voltage positive electrode of the low-voltage side. This allows the paths of multiple AC circuits within the DC / DC power converter to be changed, thereby causing the current in each AC circuit to flow through only one of the high-voltage side capacitor and the low-voltage side capacitor. This reduces the number of capacitors along the path through which the AC current flows, shortens the AC current loop, and thereby reduces power loss due to parasitic resistance. Furthermore, the DC voltage across the high-voltage side capacitor of the DC / DC power converter of the present disclosure is the difference between the input voltage and the output voltage. This reduces the DC bias of the high-voltage side capacitor, thereby increasing the equivalent capacitance of the high-voltage side capacitor. Furthermore, the high-voltage side capacitor C1 and the low-voltage side capacitor C2 are connected in series to filter out voltage ripple on the high-voltage side, while the low-voltage side capacitor C2 is used to filter out voltage ripple on the low-voltage side.

[0066] It should be noted that the above description is merely a preferred embodiment for the purpose of illustrating the present disclosure. The present disclosure is not limited to the described embodiment. The scope of the present disclosure is determined by the appended claims. Those skilled in the art may make various modifications and variations to the present disclosure without departing from the scope of the appended claims.

Claims

1. A DC / DC power converter, comprising: a high-voltage side, comprising a high-voltage positive electrode and a high-voltage negative electrode; A low-voltage side, comprising a low-voltage positive electrode and a low-voltage negative electrode, wherein the low-voltage negative electrode is electrically connected to the high-voltage negative electrode; a high-voltage side capacitor, wherein a first end of the high-voltage side capacitor is electrically connected to the high-voltage positive electrode, and a second end of the high-voltage side capacitor is electrically connected to the low-voltage positive electrode; and a power conversion circuit electrically connected between the high-voltage side and the low-voltage side and comprising at least one switch and at least one magnetic component; The power conversion circuit includes a first switch group, a second switch group and at least one magnetic component, the magnetic component includes two inductors and two transformer windings constituting a transformer, wherein the two inductors are coupled inductors of the transformer and / or parasitic inductors of the line, or the two inductors are two external inductors independent of the transformer, wherein the second ends of the transformer windings are opposite-name ends and are electrically connected to the low-voltage positive pole, wherein a first end of one of the transformer windings is electrically connected to a first end of one of the inductors, a first end of the other transformer winding is electrically connected to a first end of the other inductor, and a second end of the two inductors is electrically connected to the first switch group and the second switch group.

2. The DC / DC power converter according to claim 1 , further comprising a low-voltage side capacitor, a first end of the low-voltage side capacitor being electrically connected to the low-voltage positive electrode, a second end of the low-voltage side capacitor being electrically connected to the low-voltage negative electrode, and the low-voltage side capacitor being configured to filter voltage ripple on the low-voltage side, and the low-voltage side capacitor being electrically connected in series with the high-voltage side capacitor to filter voltage ripple on the high-voltage side. 3 . The DC / DC power converter as claimed in claim 2 , wherein the capacitance of the high-voltage side capacitor is equal to one-third of the capacitance of the low-voltage side capacitor. 4 . The DC / DC power converter as claimed in claim 1 , wherein the first switch group and the second switch group are electrically connected to the high voltage positive electrode and the high voltage negative electrode respectively, and each includes at least one switch.

5. The DC / DC power converter as claimed in claim 4 , wherein the magnetic component comprises an inductor, a first end of the inductor is electrically connected to the second end of the first switch and to the first switch group and the second switch group, and a second end of the inductor is electrically connected to the low voltage positive electrode.

6. The DC / DC power converter as claimed in claim 4 , wherein the magnetic component comprises two inductors, wherein a first end of one of the inductors and a first end of the other of the inductors are respectively electrically connected to the low voltage positive electrode, and a second end of the two inductors are electrically connected to the first switch group and the second switch group. 7 . The DC / DC power converter as claimed in claim 6 , wherein the two inductors of the magnetic component are coupled to each other to form a coupled inductor.

8. The DC / DC power converter according to claim 4, wherein the power conversion circuit comprises: The first switch group includes a first switch, a second switch, and a third switch, wherein a first end of the first switch is electrically connected to the high-voltage positive electrode, a second end of the second switch is electrically connected to a first end of the third switch, and a second end of the third switch is electrically connected to the high-voltage negative electrode; the second switch group, the second switch group comprising a fourth switch, a fifth switch, and a sixth switch, wherein a first end of the fourth switch is electrically connected to the high-voltage positive electrode, a second end of the fourth switch is electrically connected to a first end of the second switch, a first end of the fifth switch is electrically connected to a second end of the first switch, a second end of the fifth switch is electrically connected to a first end of the sixth switch, and a second end of the sixth switch is electrically connected to the high-voltage negative electrode, wherein the first switch, the second switch, the third switch, the fourth switch, the fifth switch, and the sixth switch are periodically operated according to a switching cycle; a first flying capacitor, one end of which is electrically connected to the second end of the first switch, and the other end of which is electrically connected between the second end of the second switch and the first end of the third switch; a second flying capacitor, one end of which is electrically connected to the second end of the fourth switch, and the other end of which is electrically connected between the second end of the fifth switch and the first end of the sixth switch; and A second end of one inductor of the magnetic component is electrically connected to the second end of the second switch and the first end of the third switch, and a second end of another inductor is electrically connected to the second end of the fifth switch and the first end of the sixth switch.

9. The DC / DC power converter of claim 8, wherein the switching state of the first switch, the switching state of the second switch, and the switching state of the sixth switch are the same, the switching state of the fourth switch, the switching state of the fifth switch, and the switching state of the third switch are the same, and the control signal of the first switch and the control signal of the fourth switch are 180 degrees out of phase, and the on-time of the first switch and the on-time of the fourth switch are both less than or equal to half of the switching period and greater than or equal to 0.4 times the switching period.

10. The DC / DC power converter of claim 4, wherein the power conversion circuit comprises: The first switch group includes a first switch and a third switch electrically connected in series; The second switch group includes a second switch and a fourth switch electrically connected in series, wherein a first end of the first switch is electrically connected to the high-voltage positive electrode, a second end of the first switch is electrically connected to a first end of the second switch, a second end of the second switch is electrically connected to a first end of the fourth switch, a second end of the third switch and two first ends of the fourth switch are electrically connected to the high-voltage negative electrode, and the first switch, the second switch, the third switch and the fourth switch are periodically operated according to a switching cycle; a flying capacitor, one end of which is electrically connected to the second end of the first switch, and the other end of which is electrically connected between the first end of the second switch and a first end of the third switch; and In the magnetic component, a second end of one inductor is electrically connected to the first end of the third switch, and a second end of another inductor is electrically connected to the second end of the second switch and the first end of the fourth switch.

11. The DC / DC power converter of claim 10, wherein the switching state of the first switch is the same as the switching state of the fourth switch, the switching state of the second switch is the same as the switching state of the third switch, the control signal of the first switch and the control signal of the second switch are 180 degrees out of phase, and the on-time of the first switch and the on-time of the second switch are both less than or equal to half of a switching period and greater than or equal to 0.4 times the switching period.

12. The DC / DC power converter as claimed in claim 5, wherein the power conversion circuit comprises: The first switch group includes a first switch, a first end of the first switch is electrically connected to the high-voltage positive electrode; The second switch group includes a second switch, a second end of the first switch is electrically connected to a first end of the second switch, and a second end of the second switch is electrically connected to the high-voltage negative electrode; and The magnetic component has a first end of the inductor electrically connected between the second end of the first switch and the first end of the second switch, and a second end of the inductor electrically connected to the low-voltage positive electrode.

13. The DC / DC power converter as claimed in claim 6, wherein the power conversion circuit comprises: The first switch group includes a first switch, a second switch, and a third switch, wherein a first end of the first switch is electrically connected to the high-voltage positive electrode, a second end of the second switch is electrically connected to a first end of the third switch, and a second end of the third switch is electrically connected to the high-voltage negative electrode; the second switch group, the second switch group comprising a fourth switch, a fifth switch, and a sixth switch, wherein a first end of the fourth switch is electrically connected to the high-voltage positive electrode, a second end of the fourth switch is electrically connected to a first end of the second switch, a first end of the fifth switch is electrically connected to a second end of the first switch, a second end of the fifth switch is electrically connected to a first end of the sixth switch, and a second end of the sixth switch is electrically connected to the high-voltage negative electrode, wherein the first switch, the second switch, the third switch, the fourth switch, the fifth switch, and the sixth switch are periodically operated according to a switching cycle; a first flying capacitor, one end of which is electrically connected to the second end of the first switch, and the other end of which is electrically connected between the second end of the second switch and the first end of the third switch; a second flying capacitor, one end of which is electrically connected to the second end of the fourth switch, and the other end of which is electrically connected between the second end of the fifth switch and the first end of the sixth switch; and A second end of one inductor of the magnetic component is electrically connected to the second end of the second switch and the first end of the third switch, and a second end of another inductor is electrically connected to the second end of the fifth switch and the first end of the sixth switch.

14. The DC / DC power converter as claimed in claim 6, wherein the power conversion circuit comprises: The first switch group includes a first switch and a third switch electrically connected in series; The second switch group includes a second switch and a fourth switch electrically connected in series, wherein a first end of the first switch is electrically connected to the high-voltage positive terminal, a second end of the first switch is electrically connected to a first end of the second switch, a second end of the second switch is electrically connected to a first end of the fourth switch, a second end of the third switch and two first ends of the fourth switch are electrically connected to the high-voltage negative terminal, and the first switch, the second switch, the third switch and the fourth switch are periodically operated according to a switching cycle; a flying capacitor, one end of which is electrically connected to the second end of the first switch, and the other end of which is electrically connected between the first end of the second switch and a first end of the third switch; and In the magnetic component, a second end of one inductor is electrically connected to the first end of the third switch, and a second end of another inductor is electrically connected to the second end of the second switch and the first end of the fourth switch.

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