Power converter capable of energy balancing and hybrid power supply, and power conversion method

Abstract

Provided in the present invention are a power converter capable of energy balancing and hybrid power supply, and a power conversion method. The power converter is coupled between a power source and a plurality of loads, and the power converter comprises a first switch module. The first switch module comprises an inductor, a first switch, a second switch, a third switch and a fourth switch, wherein the first switch, the second switch, the third switch and the fourth switch are configured to be switched on or off, such that the inductor performs energy storage or energy release, so as to convert the power source into a plurality of voltages to the plurality of loads.

Description

Power converter and power conversion method capable of balancing energy and hybrid power supply Technical Field

[0001] The present invention relates to an energy balancing circuit and a capacitor voltage adjustment method, and in particular to a power converter and a power conversion method capable of balancing energy and hybrid power supply. Background Art

[0002] In recent years, non-isolated power converters, such as bidirectional power converters and single-to-multi power converters, have been widely used in uninterruptible power supply systems, renewable energy systems, fuel cells, hybrid electric vehicles and other occasions. The power converter can provide a single power supply to multiple loads, or transfer the power from one load to another load to achieve the purpose of energy balance and hybrid power supply. In the above occasions, the design goals of the power converter include at least: (1) high conversion efficiency; (2) the ability to withstand large currents; (3) low input current ripple; (4) small size and low cost. Therefore, how to provide a single-to-multi power converter that can be applied to the above occasions and meet the design goals is one of the important issues in this field.

[0003] Summary of the Invention

[0004] One object of the present invention is to provide a power converter. The power converter is coupled between a power source and multiple loads. The power converter includes a first switch module. The first switch module includes an inductor, a first switch, a second switch, a third switch, and a fourth switch. The first switch includes a first end connected to a first input end, and a second end connected to the first end of the inductor. The second switch includes a first end connected to the second end of the inductor, and a second end connected to the second input end. The third switch includes a first end connected to the first output end, and a second end connected to the first end of the second switch and the second end of the inductor. The fourth switch includes a first end connected to the second end of the first switch and the first end of the inductor, and a second end connected to the second output end. The first switch, the second switch, the third switch, and the fourth switch are configured to be turned on or off, so that the inductor stores energy or releases energy, thereby converting the power source into multiple voltages for multiple loads.

[0005] Another object of the present invention is to provide a power conversion method. The power conversion method includes the steps of: detecting voltages of multiple loads to determine whether to operate in one of a first to a sixth operating mode; and controlling the on and off states of a first switch, a second switch, a third switch, and a fourth switch based on the operating mode to cause an inductor to store or release energy, thereby establishing a first voltage, a second voltage, and a third voltage for the multiple loads, respectively.

[0006] Therefore, the power converter and power conversion method proposed in the present invention have the following features and advantages: 1. By adjusting the duty cycle of the control switch, the voltage of the capacitor unit can be controlled, which can reduce the number of components and thus achieve advantages such as small size and low cost. 2. By storing and releasing energy in the inductor and controlling multiple switches, the energy transfer between the voltages of the capacitor units can be controlled, and the voltage of the capacitor units can be adjusted to meet different load requirements.

[0007] In order to further understand the techniques, means and effects adopted by the present invention to achieve the intended objectives, please refer to the following detailed description of the present invention and the accompanying drawings. It is believed that the objectives, features and characteristics of the present invention can be further understood in detail. However, the accompanying drawings are provided for reference and illustration only and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a circuit diagram of a power converter according to a first embodiment of the present invention;

[0009] FIG2 is a schematic diagram of a power converter according to the present invention in a first operating mode;

[0010] FIG3 is a schematic diagram of the power converter of the present invention in a second operation mode;

[0011] FIG4 is a schematic diagram of the power converter of the present invention in a third operating mode;

[0012] FIG5 is a schematic diagram of the power converter of the present invention in a fourth operating mode;

[0013] FIG6 is a schematic diagram of the power converter of the present invention in a fifth operating mode;

[0014] FIG7 is a schematic diagram of the power converter of the present invention in a sixth operating mode;

[0015] FIG8 is a circuit diagram of a power converter according to a second embodiment of the present invention;

[0016] FIG9 is a circuit diagram of a power converter according to a third embodiment of the present invention;

[0017] FIG10 is a circuit diagram of a power converter according to a fourth embodiment of the present invention;

[0018] FIG11 is a circuit diagram of a power converter according to a fifth embodiment of the present invention;

[0019] FIG12 is a circuit diagram of a power converter according to a sixth embodiment of the present invention;

[0020] FIG13 is a flow chart of a power conversion method according to the present invention.

[0021] Explanation of Reference Numerals 10, 20, 30, 40, 50, 60: power converter 11: power supply 12: first switch module 12-1: first switch module 12-2: second switch module 12-3: first switch module 12-4: second switch module S1, S2, S3, S4: first to fourth switches L1: inductor IN1: first input terminal IN2: second input terminal OUT1: first output terminal OUT2: second output terminal OUT3: third output terminal 51, 52, 53: first to third power sources C1, C2, C3, C4: first to fourth capacitors V1, V2, V3, V4: first to fourth voltages 91, 92, 93, 94: first to fourth loads Ps1 to Ps6: first to sixth energy storage paths Pr1 to Pr6: first to sixth energy release paths DETAILED DESCRIPTION

[0022] The technical content and detailed description of the present invention are described as follows with reference to the accompanying drawings.

[0023] Please refer to FIG. 1 , which is a circuit diagram of a power converter according to a first embodiment of the present invention. A power converter 10 is coupled between a power source 11 and multiple loads (including a first load 91, a second load 92, and a third load 93). The power converter 10 includes a first switching module 12. As shown in FIG. 1 , the first switching module 12 includes an inductor L1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. Furthermore, a first load 91 among the multiple loads is connected between a first input terminal IN1 and a first output terminal OUT1, a second load 92 among the multiple loads is connected between the first output terminal OUT1 and the second output terminal OUT2, and a third load 93 among the multiple loads is connected between a second input terminal IN2 and a second output terminal OUT2.

[0024] The first switch S1 includes a first end and a second end, wherein the first end of the first switch S1 is connected to the first input terminal IN1; the second end of the first switch S1 is connected to the first end of the inductor L1. The second switch S2 includes a first end and a second end, wherein the first end of the second switch S2 is connected to the second end of the inductor L1; the second end of the second switch S2 is connected to the second input terminal IN2. The third switch S3 includes a first end and a second end, wherein the first end of the third switch S3 is connected to the first output terminal OUT1; the second end of the third switch S3 is connected to the first end of the second switch S2 and the second end of the inductor L1. The fourth switch S4 includes a first end and a second end, wherein the first end of the fourth switch S4 is connected to the second end of the first switch S1 and the first end of the inductor L1; the second end of the fourth switch S4 is connected to the second output terminal OUT2.

[0025] The first switch S1 , the second switch S2 , the third switch S3 and the fourth switch S4 are configured to be turned on or off, so that the inductor L1 stores or releases energy, thereby converting the power source 11 into multiple voltages for multiple loads 91 , 92 , 93 .

[0026] As shown in FIG1 , the power converter 10 further includes a first capacitor C1, a second capacitor C2, and a third capacitor C3. The first capacitor C1 is connected between the first input terminal IN1 and the first output terminal OUT1 and is configured to establish a first voltage V1 of a plurality of voltages. The second capacitor C2 is connected between the first output terminal OUT1 and the second output terminal OUT2 and is configured to establish a second voltage V2 of a plurality of voltages. The third capacitor C3 is connected between the second input terminal IN2 and the second output terminal OUT2 and is configured to establish a third voltage V3 of a plurality of voltages.

[0027] In one embodiment, the power source 11 may be a DC power source connected between the first input terminal IN1 and the second input terminal IN2 , and the first switch S1 , the second switch S2 , the third switch S3 and the fourth switch S4 are N-type synchronous rectification switches.

[0028] In one embodiment, the power converter 10 is controlled by a controller (not shown), such as a digital signal processor, a programmable logic controller, a microcontroller, etc. The controller is configured to detect the voltage change rate of multiple loads (or capacitors) to determine whether the power converter 10 executes one of the first to sixth operating modes. Specifically, when the energy drop rate of one load is significantly lower than the energy drop rate of other loads, the energy stored in the load with the lowest energy drop rate needs to be transferred to the load with the highest energy drop rate. In other words, transferring the energy stored in the least power-consuming load to the most power-consuming load can achieve energy balance and mixed power supply. In other embodiments, the controller receives user instructions to control which operating mode the power converter 10 executes to achieve energy scheduling.

[0029] Please refer to Figure 2, which is a schematic diagram of the power converter of the present invention in the first operating mode. As shown in Figure 2, when the first switch S1 is turned on, the energy stored in the first capacitor C1 stores energy in the inductor L1 (shown as the first energy storage path Ps1 in the figure). At this time, the voltage across the inductor L1 is a first voltage V1. When the first switch S1 is turned off, the energy stored in the inductor L1 is released to the second capacitor C2 (shown as the first energy release path Pr1 in the figure), thereby establishing a second voltage V2 across the second capacitor C2. In the first operating mode, the power converter can transfer energy from the first capacitor C1 to the second capacitor C2 and regulate the voltage of the second capacitor C2. In one embodiment, the conditions for the power converter 10 to operate in the first operating mode include at least one of: E1>E3>E2; and E1>>E2, where E1, E2, and E3 represent the energy stored in the first load 91, the second load 92, and the third load 93, respectively. In the first operation mode, because the first energy storage path Ps1 and the first energy release path Pr1 pass through the body diode of the third switch S3 , the third switch S3 can be replaced by a synchronous rectification switch or a diode.

[0030] Please refer to Figure 3, which is a schematic diagram of the power converter of the present invention in the second operating mode. As shown in Figure 3, when the third switch S3 and the fourth switch S4 are turned on, the energy stored in the second capacitor C2 stores energy in the inductor L1 (shown as the second energy storage path Ps2). At this time, the voltage across the inductor L1 is the second voltage V2. When the fourth switch S4 is turned off while the third switch S3 remains on, the energy stored in the inductor L1 is released to the first capacitor C1 (shown as the second energy release path Pr2). As a result, a first voltage V1 is established across the first capacitor C1. In the second operating mode, the power converter can transfer energy from the second capacitor C2 to the first capacitor C1 and regulate the voltage of the first capacitor C1. In one embodiment, the conditions for the power converter 10 to operate in the second operating mode include at least one of: E2>E3>E1; and E2>>E1. In the second mode, because the second energy release path Pr2 passes through the body diode of the first switch S1, the first switch S1 can be replaced with a synchronous rectifier switch or diode.

[0031] Please refer to Figure 4, which is a schematic diagram of the power converter of the present invention in the third operating mode. As shown in Figure 4, when the third switch S3 and the fourth switch S4 are both on, the energy stored in the second capacitor C2 stores energy in the inductor L1 (shown as the third energy storage path Ps3). At this time, the voltage across the inductor L1 is the second voltage V2. When the third switch S3 is off and the fourth switch S4 remains on, the energy stored in the inductor L1 is released to the third capacitor C3 (shown as the third energy release path Pr3). This establishes a third voltage V3 across the third capacitor C3. In the third operating mode, the power converter can transfer energy from the second capacitor C2 to the third capacitor C3 and regulate the voltage of the third capacitor C3. In one embodiment, the conditions for the power converter 10 to operate in the third operating mode include at least one of: E2 > E1 > E3; and E2 >> E3. In the third mode, because the third energy release path Pr3 passes through the body diode of the second switch S2, the second switch S2 can be replaced with a synchronous rectifier switch or diode.

[0032] Please refer to Figure 5, which is a schematic diagram of the power converter of the present invention in the fourth operating mode. As shown in Figure 5, when the second switch S2 is turned on, the energy stored in the third capacitor C3 stores energy in the inductor L1 (shown as the fourth energy storage path Ps4 in the figure). At this time, the voltage across the inductor L1 is the third voltage V3. When the second switch S2 is turned off, the energy stored in the inductor L1 is released to the second capacitor C2 (shown as the fourth energy release path Pr4 in the figure), thereby establishing a second voltage V2 across the second capacitor C2. In the fourth operating mode, the power converter can transfer energy from the third capacitor C3 to the second capacitor C2 and regulate the voltage of the second capacitor C2. In one embodiment, the conditions for the power converter 10 to operate in the fourth operating mode include at least one of: E3>E1>E2; and E3>>E2. In the fourth mode, because the fourth energy storage path Ps4 and the fourth energy release path Pr4 pass through the body diode of the fourth switch S4, the fourth switch S4 can be replaced with a synchronous rectification switch or diode.

[0033] Please refer to FIG. 6, which is a schematic diagram of the power converter of the present invention in the fifth operation mode. As shown in FIG. 5, based on the conduction of the third switch S3 and the conduction of the fourth switch S4, the energy stored in the second capacitor C2 stores energy in the inductor L1 (the fifth energy storage path Ps5 as shown in the figure). At this time, the voltage across the inductor L1 is the second voltage V2. Based on the turn-off of the third switch S3 and the turn-off of the fourth switch S4, the energy stored in the inductor L1 is released to the first capacitor C1, the second capacitor C2, and the third capacitor C3 (the fifth energy release path Pr5 as shown in the figure). Therefore, the first voltage V1 is established on the first capacitor C1, the second voltage V2 is established on the second capacitor C2, and the third voltage V3 is established on the third capacitor C3. And a voltage magnitude of V1 + V2 + V3 is established on the series path of the three capacitors. This capacitor energy transfer third operation mode can realize the energy transfer of the second capacitor C2 to the first capacitor C1 and the third capacitor C3, and stabilize the voltage of the first capacitor C1 and the third capacitor C3. In an embodiment, the conditions for the power converter 10 to execute the fifth operation mode include at least one of: E2 > E1 ≒ E3; and E2 >> E1 ≒ E3. In the fifth mode, since the third energy release path Pr3 passes through the body diodes of the first switch S1 and the second switch S2, the first switch S1 and the second switch S2 can be replaced with synchronous rectifier switches or diodes.

[0034] Please refer to FIG. 7, which is a schematic diagram of the power converter of the present invention in the sixth operation mode. As shown in FIG. 7, based on the conduction of the first switch S1 and the conduction of the second switch S2, the energy stored in the first capacitor C1, the energy stored in the second capacitor C2, and the energy stored in the third capacitor C3 store energy in the inductor L1 (the sixth energy storage path Ps6 as shown in the figure). At this time, the voltage across the inductor L1 is the voltage magnitude of V1 + V2 + V3. Based on the turn-off of the first switch S1 or the turn-off of the second switch S2, the energy stored in the inductor L1 is released to the second capacitor C2 (the sixth energy release path Pr6 as shown in the figure). Therefore, the second voltage V2 is established on the second capacitor C2. This capacitor energy transfer sixth operation mode can realize the energy transfer of the first capacitor C1, the second capacitor C2, and the third capacitor C3 to the second capacitor C2, and stabilize the voltage of the second capacitor C2. In an embodiment, the conditions for the power converter 10 to execute the sixth operation mode include at least one of: E2 < E1 ≒ E3; and E2 << E1 ≒ E3. In the sixth mode, since the sixth energy release path Pr6 passes through the body diodes of the third switch S3 and the fourth switch S4, the third switch S3 and the fourth switch S4 can be replaced with synchronous rectifier switches or diodes.

[0035] Please refer to FIG8 , which is a circuit diagram of a power converter according to a second embodiment of the present invention. The biggest difference between the second embodiment shown in FIG8 and the first embodiment shown in FIG1 is that the second embodiment is a multi-capacitor stacking (i.e., multi-capacitor string connection) architecture. In this embodiment, the multi-capacitor string architecture includes a first capacitor string, a second capacitor string, and a third capacitor string. The first capacitor string is connected between the first input terminal IN1 and the first output terminal OUT1, and is configured to establish multiple voltages (e.g., voltage V 11 ,V 12 ) of the first voltage V1, and includes a plurality of first capacitors C connected in series with each other 11 ,C 12 The second capacitor string is connected between the first output terminal OUT1 and the second output terminal OUT2 and is configured to establish a plurality of voltages (eg, voltage V 21 ,V 22 ) of the second voltage V2, and includes a plurality of second capacitors C connected in series with each other 21 ,C 22 The third capacitor string is connected between the second input terminal IN2 and the second output terminal OUT2 and is configured to establish a plurality of voltages (eg, voltage V 31 ,V 32 ) of the third voltage V3, and includes a plurality of third capacitors C connected in series with each other 31 ,C 32 . In this circuit architecture, the power supply 11 is a DC power supply, connected between the first input terminal IN1 and the second input terminal IN2; and the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are N-type synchronous rectifier switches. Please refer to Figure 9, which is a circuit diagram of the power converter 30 according to the third embodiment of the present invention. In this embodiment, the power supply 11 can be an AC power supply, so the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are back-to-back bidirectional switches. Therefore, for the different polarities of the positive and negative half-cycles of the AC power supply, the purpose of capacitor voltage adjustment can be achieved through the bidirectional conduction characteristics of the back-to-back bidirectional switches.

[0036] Please refer to Figure 10, which is a circuit diagram of a power converter 40 according to a fourth embodiment of the present invention. The major difference between this embodiment and the first embodiment shown in Figure 1 is that the power converter of the fourth embodiment has two switch modules, namely a first switch module 12-1 and a second switch module 12-2. The number of capacitor units C1, C2, C3, and C4 is four, which means that a fourth capacitor C4 is added. In this embodiment, the first switch module 12-1 corresponds to the first switch module 12 of the first embodiment. Furthermore, the first end of the third switch S3 of the second switch module 12-2 is connected to the second output terminal OUT2, and the second end of the fourth switch S4 of the second switch module 12-2 is connected to the third output terminal OUT3. The fourth capacitor C4 is connected between the third output terminal OUT3 and the second input terminal IN2 and is configured to establish a fourth voltage V4 of the plurality of voltages. A fourth load 94 of the plurality of loads is connected between the third output terminal OUT3 and the second input terminal IN2.

[0037] Please refer to Figure 11, which is a circuit diagram of a power converter 50 according to a fifth embodiment of the present invention. The power converter 50 shown in Figure 11 is coupled between a power source 11 and multiple loads (including a first load 91, a second load 92, a third load 93, and a fourth load 94). The power converter 50 includes a first switch module 12-3. The first switch module 12-3 includes an inductor L1, a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The first switch S1 includes a first end connected to the first output terminal OUT1 and a second end connected to the first end of the inductor L1. The second switch S2 includes a first end connected to the second end of the inductor L1 and a second end connected to the second input terminal IN2. The third switch S3 includes a first end connected to the second output terminal OUT2 and a second end connected to the first end of the second switch S2 and the second end of the inductor L1. The fourth switch S4 includes a first end connected to the second end of the first switch S1 and the first end of the inductor L1, and a second end connected to the third output terminal OUT3.

[0038] The power converter 50 shown in FIG11 further includes a first capacitor C1, a second capacitor C2, and a third capacitor C3. The first capacitor C1 is connected between the first input terminal IN1 and the first output terminal OUT1 and is configured to establish a first voltage V1 of a plurality of voltages. The second capacitor C2 is connected between the first output terminal OUT1 and the second output terminal OUT2 and is configured to establish a second voltage V2 of a plurality of voltages. The third capacitor C3 is connected between the second input terminal IN2 and the second output terminal OUT2 and is configured to establish a third voltage V3 of a plurality of voltages. The power supply 11 is a DC power supply connected between the first input terminal IN1 and the second input terminal IN2, and the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are N-type synchronous rectifier switches.

[0039] The power converter 50 shown in FIG11 further includes a second switch module 12-4 and a fourth capacitor C4. The second switch module 12-4 includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The first end of the first switch S1 is connected to the first input terminal IN1, the second end of the second switch S2 is connected to the third output terminal OUT3, the first end of the third switch S3 is connected to the first output terminal OUT1, and the second end of the fourth switch S4 is connected to the second output terminal OUT2. The fourth capacitor C4 is connected between the third output terminal OUT3 and the second input terminal IN2.

[0040] A first load 91 among the multiple loads is connected between the first input terminal IN1 and the first output terminal OUT1. A second load 92 among the multiple loads is connected between the first output terminal OUT1 and the second output terminal OUT2. A third load 93 among the multiple loads is connected between the second output terminal OUT2 and the third output terminal OUT3. A fourth load 94 among the multiple loads is connected between the third output terminal OUT3 and the second input terminal IN2.

[0041] In different embodiments, the power supply 11 may be an AC power supply, and thus the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are back-to-back bidirectional switches. Therefore, for the different polarities of the positive and negative half-cycles of the AC power supply, the purpose of capacitor voltage adjustment can be achieved through the bidirectional conduction characteristics of the back-to-back bidirectional switches.

[0042] Please refer to Figure 12, which is a circuit diagram of a power converter 60 according to a sixth embodiment of the present invention. When multiple loads supply power to the power supply 11: one of the multiple loads serves as the first power supply 51, connected between the first input terminal IN1 and the first output terminal OUT1. One of the multiple loads serves as the second power supply 52, connected between the first output terminal OUT1 and the second output terminal OUT2. One of the multiple loads serves as the third power supply 53, connected between the second input terminal IN2 and the second output terminal OUT2. In this embodiment, the power supply 11 serves as a load 90, connected between the first input terminal IN1 and the second input terminal IN2. The first power supply 51 and the first capacitor C1 can be batteries, such as but not limited to supercapacitors, lithium batteries, or lead-acid batteries. Similarly, the second power supply 52 and the second capacitor C2, as well as the third power supply 53 and the third capacitor C3, are all batteries. By providing a stable input voltage from the battery and controlling the switches S1, S2, S3, and S4 of the switch module 12 as described above, bidirectional power flow can be achieved, stabilizing the battery voltage for charging and discharging to meet the needs of the power supply 11 (i.e., the load 90).

[0043] Please refer to FIG. 13 , which is a flow chart of a power conversion method according to the present invention. This method is described in conjunction with one of the aforementioned different power converter embodiments. The power converter includes a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, an inductor L1, a first capacitor C1, a second capacitor C2, and a third capacitor C3. The power conversion method includes the steps of detecting voltages of multiple loads to determine whether to operate in one of the first to sixth operating modes (step S10). Then, based on the operating mode, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are controlled to turn on and off, causing the inductor L1 to store or release energy, thereby establishing a first voltage V1, a second voltage V2, and a third voltage V3 for the multiple loads (step S20).

[0044] In the first operating mode, the steps include: turning on the first switch S1 so that the energy stored in the first capacitor C1 stores energy in the inductor L1 to establish a first voltage V1 on the inductor L1; and turning off the first switch S1 so that the first voltage V1 stored in the inductor L1 releases energy to the second capacitor C2 to establish a second voltage V2 on the second capacitor C2.

[0045] In the second operating mode, the steps include: turning on the third switch S3 and the fourth switch S4, so that the energy stored in the second capacitor C2 stores energy in the inductor L1, thereby establishing a second voltage V2 on the inductor L1; and turning off the fourth switch S4 and turning on the third switch S3, so that the second voltage V2 stored in the inductor L1 releases energy to the first capacitor C1, thereby establishing a first voltage V1 on the first capacitor C1.

[0046] In the third operating mode, the steps include: turning on the third switch S3 and the fourth switch S4 so that the energy stored in the second capacitor C2 is stored in the inductor L1 to establish a second voltage V2 on the inductor L1; and turning off the third switch S3 and turning on the fourth switch S4 so that the second voltage V2 stored in the inductor L1 is released to the third capacitor C3 to establish a third voltage V3 on the third capacitor C3.

[0047] In the fourth operating mode, the steps include: turning on the second switch S2 so that the energy stored in the third capacitor C3 stores energy in the inductor L1 to establish a third voltage V3 on the inductor L1; and turning off the second switch S2 so that the third voltage V3 stored in the inductor L1 releases energy to the second capacitor C2 to establish a second voltage V2 on the second capacitor C2.

[0048] In the fifth operating mode, the steps include: turning on the third switch S3 and the fourth switch S4 so that the energy stored in the second capacitor C2 stores energy in the inductor L1, thereby establishing a second voltage V2 on the inductor L1; and turning off the third switch S3 and the fourth switch S4 so that the energy stored in the inductor L1 is released to the first capacitor C1, the second capacitor C2, and the third capacitor C3, thereby establishing a first voltage V1 on the first capacitor C1, a second voltage V2 on the second capacitor C2, and a third voltage V3 on the third capacitor C3.

[0049] In the sixth operating mode, the steps include: turning on the first switch S1 and the second switch S2 so that the energy stored in the first capacitor C1, the second capacitor C2, and the third capacitor C3 are stored in the inductor L1, thereby establishing a total voltage V1+V2+V3 (i.e., the sum of the first voltage V1, the second voltage V2, and the third voltage V3) on the inductor L1; and turning off the first switch S1 or the second switch S2 so that the total voltage stored in the inductor L1 is released to the second capacitor C2, thereby establishing a second voltage V2 on the second capacitor C2.

[0050] In summary, the present invention has the following features and advantages:

[0051] 1. The power converter proposed in the present invention controls the voltage of the capacitor unit by adjusting the duty cycle of the control switch, thereby reducing the number of components and achieving advantages such as small size and low cost.

[0052] 2. Through the energy storage and release of the inductor and the control of multiple switches, the energy transfer between the voltages of the capacitor units can be controlled, and the voltage of the capacitor units can be adjusted to meet different load requirements.

[0053] The above description is merely a detailed description and drawings of preferred specific embodiments of the present invention. However, the features of the present invention are not limited thereto and are not intended to limit the present invention. The full scope of the present invention shall be subject to the following claims. All embodiments that conform to the spirit of the claims of the present invention and similar variations thereof shall be included in the scope of the present invention. Any changes or modifications that can be easily conceived by any person skilled in the art within the scope of the present invention shall be covered by the following claims of this case.

Claims

1. A power converter coupled between a power source and a plurality of loads, comprising: The first switch module comprises: inductance; A first switch includes a first end connected to the first input end; and a second end connected to the first end of the inductor; A second switch including a first end connected to the second end of the inductor; and a second end connected to the second input end; a third switch including a first end connected to the first output end; and a second end connected to the first end of the second switch and the second end of the inductor; and a fourth switch, comprising a first end connected to the second end of the first switch and the first end of the inductor; and a second end connected to the second output end; The first switch, the second switch, the third switch and the fourth switch are configured to be turned on or off, so that the inductor stores energy or releases energy, so as to convert the power source into a plurality of voltages for the plurality of loads.

2. The power converter according to claim 1, further comprising: A first capacitor connected between the first input terminal and the first output terminal, configured to establish a first voltage of the plurality of voltages; A second capacitor connected between the first output terminal and the second output terminal, configured to establish a second voltage of the plurality of voltages; as well as a third capacitor connected between the second input terminal and the second output terminal, configured to establish a third voltage of the plurality of voltages; The power supply is a direct current power supply connected between the first input terminal and the second input terminal; and the first switch, the second switch, the third switch and the fourth switch are N-type synchronous rectification switches.

3. The power converter according to claim 1, further comprising: A first capacitor string, connected between the first input terminal and the first output terminal, configured to establish a first voltage of the plurality of voltages, and comprising a plurality of first capacitors connected in series with each other; A second capacitor string, connected between the first output terminal and the second output terminal, configured to establish a second voltage of the plurality of voltages, and comprising a plurality of second capacitors connected in series with each other; as well as a third capacitor string connected between the second input terminal and the second output terminal, configured to establish a third voltage of the plurality of voltages, and comprising a plurality of third capacitors connected in series with each other; The power supply is a direct current power supply connected between the first input terminal and the second input terminal; and the first switch, the second switch, the third switch and the fourth switch are N-type synchronous rectification switches.

4. The power converter according to claim 1, wherein a first load among the plurality of loads is connected between the first input terminal and the first output terminal, a second load among the plurality of loads is connected between the first output terminal and the second output terminal, and a third load among the plurality of loads is connected between the second input terminal and the second output terminal. 5 . The power converter according to claim 1 , wherein the power source is an AC power source; and the first switch, the second switch, the third switch, and the fourth switch are back-to-back bidirectional switches.

6. The power converter according to claim 1, further comprising: A second switch module, wherein a first end of a third switch of the second switch module is connected to the second output end, and a second end of a fourth switch of the second switch module is connected to the third output end; as well as a fourth capacitor connected between the third output terminal and the second input terminal, and configured to establish a fourth voltage of the plurality of voltages; The fourth load among the plurality of loads is connected between the third output terminal and the second input terminal.

7. The power converter according to claim 1, wherein: When the multiple loads supply power to the power supply: One of the plurality of loads is used as a first power source and is connected between the first input terminal and the first output terminal; One of the plurality of loads is used as a second power source and is connected between the first output terminal and the second output terminal; One of the plurality of loads is used as a third power source and is connected between the second input terminal and the second output terminal; and The power supply serves as a load and is connected between the first input terminal and the second input terminal.

8. A power converter coupled between a power source and a plurality of loads, comprising: The first switch module comprises: inductance; A first switch includes a first end connected to the first output end; and a second end connected to the first end of the inductor; A second switch including a first end connected to the second end of the inductor; and a second end connected to the second input end; a third switch including a first end connected to the second output end; and a second end connected to the first end of the second switch and the second end of the inductor; and The fourth switch includes a first end connected to the second end of the first switch and the first end of the inductor; and a second end connected to the third output end.

9. The power converter according to claim 8, further comprising: A first capacitor connected between the first input terminal and the first output terminal, configured to establish a first voltage of the plurality of voltages; A second capacitor connected between the first output terminal and the second output terminal, configured to establish a second voltage of the plurality of voltages; A third capacitor connected between the second input terminal and the second output terminal, configured to establish a third voltage of the plurality of voltages; and The power supply is a direct current power supply connected between the first input terminal and the second input terminal; and the first switch, the second switch, the third switch and the fourth switch are N-type synchronous rectification switches.

10. The power converter according to claim 9, further comprising: a second switch module, wherein a first end of a first switch of the second switch module is connected to the first input end, a second end of a second switch of the second switch module is connected to the third output end, a first end of a third switch of the second switch module is connected to the first output end, and a second end of a fourth switch of the second switch module is connected to the second output end; as well as A fourth capacitor is connected between the third output terminal and the second input terminal.

11. The power converter according to claim 9, wherein A first load among the plurality of loads is connected between the first input terminal and the first output terminal, A second load among the plurality of loads is connected between the first output terminal and the second output terminal, A third load among the plurality of loads is connected between the second output terminal and the third output terminal, and A fourth load among the plurality of loads is connected between the third output terminal and the second input terminal. 12 . The power converter according to claim 8 , wherein the power source is an AC power source; and the first switch, the second switch, the third switch, and the fourth switch are back-to-back bidirectional switches.

13. A power conversion method, used in the power converter according to claim 1, wherein the power converter comprises a first switch, a second switch, a third switch, a fourth switch, an inductor, a first capacitor, a second capacitor and a third capacitor, and the power conversion method comprises the steps of: Detecting voltages of a plurality of loads to determine whether to perform one of a first operation mode to a sixth operation mode; According to one of the first operation mode to the sixth operation mode, the first switch, the second switch, the third switch and the fourth switch are controlled to be turned on and off, so that the inductor stores energy or releases energy, thereby respectively establishing a first voltage, a second voltage and a third voltage for the multiple loads.

14. The power conversion method according to claim 13, in the first operation mode, comprising the steps of: Turning on the first switch so that the energy stored in the first capacitor stores energy in the inductor to establish the first voltage on the inductor; and The first switch is turned off, so that the first voltage stored in the inductor releases energy to the second capacitor, so as to establish the second voltage on the second capacitor.

15. The power conversion method according to claim 13, in the second operation mode, comprises the steps of: Turning on the third switch and the fourth switch so that the energy stored in the second capacitor stores energy in the inductor to establish the second voltage on the inductor; and The fourth switch is turned off and the third switch is turned on, so that the second voltage stored in the inductor releases energy to the first capacitor to establish the first voltage on the first capacitor.

16. The power conversion method according to claim 13, in the third operation mode, comprising the steps of: Turning on the third switch and the fourth switch so that the energy stored in the second capacitor stores energy in the inductor to establish the second voltage on the inductor; and The third switch is turned off and the fourth switch is turned on, so that the second voltage stored in the inductor releases energy to the third capacitor to establish the third voltage on the third capacitor.

17. The power conversion method according to claim 13, in the fourth operation mode, comprises the steps of: Turning on the second switch allows the energy stored in the third capacitor to store energy in the inductor, so as to establish the third voltage on the inductor; and The second switch is turned off to release the third voltage stored in the inductor to the second capacitor, so as to establish the second voltage on the second capacitor.

18. The power conversion method according to claim 13, in the fifth operation mode, comprising the steps of: Turning on the third switch and the fourth switch so that the energy stored in the second capacitor stores energy in the inductor to establish the second voltage on the inductor; and The third switch and the fourth switch are turned off to release the energy stored in the inductor to the first capacitor, the second capacitor and the third capacitor to establish the first voltage on the first capacitor, the second voltage on the second capacitor and the third voltage on the third capacitor.

19. The power conversion method according to claim 13, in the sixth operation mode, comprising the steps of: Turning on the first switch and the second switch so that energy stored in the first capacitor, energy stored in the second capacitor, and energy stored in the third capacitor stores energy in the inductor to establish a total voltage on the inductor; and The first switch or the second switch is turned off, so that the total voltage stored in the inductor releases energy to the second capacitor, so as to establish the second voltage on the second capacitor.

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