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

Abstract

The invention provides a power converter capable of balancing energy and hybrid power supply and a power conversion method, the power converter is coupled between a power supply 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. The first switch, the second switch, the third switch and the fourth switch are configured to be switched on or switched off, so that the inductor stores energy or releases energy, and the power supply is converted into a plurality of voltages to be supplied to the loads.

Description

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 topics in this field. Summary of the invention

[0003] One object of the present invention is to provide a power converter. The power converter is coupled between a power source and a plurality of 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 a first end of the inductor. The second switch includes a first end connected to a second end of the inductor, and a second end connected to a second input end. The third switch includes a first end connected to a first output end, and a second end connected to a first end of the second switch and a second end of the inductor. The fourth switch includes a first end connected to a second end of the first switch and a first end of the inductor, and a second end connected to a 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 to convert the power source into multiple voltages for multiple loads.

[0004] Another object of the present invention is to provide a power conversion method. The power conversion method includes the steps of: detecting the voltage of multiple loads to determine whether to perform one of the first operation mode to the sixth operation mode; according to one of the first operation mode to the sixth operation mode, controlling the conduction and disconnection of the first switch, the second switch, the third switch and the fourth switch to make the inductor store energy or release energy, thereby respectively establishing the first voltage, the second voltage and the third voltage for the multiple loads.

[0005] Therefore, the power converter and power conversion method proposed in the present invention have the following characteristics 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 achieve the advantages of small size and low cost; 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 unit can be adjusted to meet different load requirements.

[0006] In order to further understand the technology, means and effects adopted by the present invention to achieve the predetermined purpose, please refer to the following detailed description and drawings of the present invention. It is believed that the purpose, characteristics and features of the present invention can be understood in depth and in detail. However, the attached drawings are only provided for reference and explanation and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a circuit diagram of a power converter according to a first embodiment of the present invention;

[0008] Figure 2 is a schematic diagram of a power converter of the present invention in a first operation mode;

[0009] Figure 3 is a schematic diagram of the power converter of the present invention in a second operation mode;

[0010] Figure 4 is a schematic diagram of the power converter of the present invention in a third operation mode;

[0011] Figure 5 is a schematic diagram of the power converter of the present invention in a fourth operation mode;

[0012] Figure 6 is a schematic diagram of the power converter of the present invention in a fifth operation mode;

[0013] Figure 7 is a schematic diagram of the power converter of the present invention in a sixth operation mode;

[0014] Figure 8 is a circuit diagram of a power converter according to a second embodiment of the present invention;

[0015] Fig. 9 is a circuit diagram of a power converter according to a third embodiment of the present invention;

[0016] Fig.10 is a circuit diagram of a power converter according to a fourth embodiment of the present invention;

[0017] Fig.11 is a circuit diagram of a power converter according to a fifth embodiment of the present invention;

[0018] Fig.12is a circuit diagram of a power converter according to a sixth embodiment of the present invention;

[0019] Fig.13 is a flow chart of a power conversion method of the present invention.

[0020] Description of Reference Numerals

[0021] 10,20,30,40,50,60: Power converter

[0022] 11: Power supply

[0023] 12: First switch module

[0024] 12-1: First switch module

[0025] 12-2: Second switch module

[0026] 12-3: First switch module

[0027] 12-4: Second switch module

[0028] S1, S2, S3, S4: 1st to 4th switches

[0029] L1: Inductor

[0030] IN1: First input terminal

[0031] IN2: Second input terminal

[0032] OUT1: First output terminal

[0033] OUT2: Second output terminal

[0034] OUT3: The third output terminal

[0035] 51,52,53: First to third power supply

[0036] C1, C2, C3, C4: first to fourth capacitors

[0037] V1, V2, V3, V4: First to fourth voltage

[0038] 91,92,93,94: First load to fourth load

[0039] Ps1~Ps6: The first to sixth energy storage paths

[0040] Pr1~Pr6: The first to sixth energy release paths DETAILED DESCRIPTION

[0041] The technical content and detailed description of the present invention are described as follows with reference to the accompanying drawings.

[0042] See also Figure 1, which is a circuit diagram of a power converter according to a first embodiment of the present invention. The power converter 10 is coupled between a power source 11 and a plurality of loads (including a first load 91, a second load 92 and a third load 93), and the power converter 10 includes a first switch module 12. Figure 1 The first switch module 12 shown includes an inductor L1, a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4. In addition, 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, and a third load 93 among the multiple loads is connected between the second input terminal IN2 and the second output terminal OUT2.

[0043] 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.

[0044] 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 energy or releases energy, so as to convert the power source 11 into a plurality of voltages for the plurality of loads 91 , 92 , 93 .

[0045] like Figure 1 As shown, 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.

[0046] 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.

[0047] 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.

[0048] See also Figure 2 , which is a schematic diagram of the power converter of the present invention in the first operation mode. Figure 2 As shown, based on the first switch S1 being turned on, the energy stored in the first capacitor C1 stores energy in the inductor L1 (the first energy storage path Ps1 shown in the figure), and the voltage across the inductor L1 is the first voltage V1. Based on the first switch S1 being turned off, the energy stored in the inductor L1 is released to the second capacitor C2 (the first energy release path Pr1 shown in the figure), so that the second voltage V2 is established on the second capacitor C2. In the first operation mode, the power converter can realize the energy transfer from the first capacitor C1 to the second capacitor C2 and stabilize the voltage of the second capacitor C2. In one embodiment, the conditions for the power converter 10 to perform the first operation mode include: E1>E3>E2; and at least one of E1>>E2, wherein E1, E2, and E3 are 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.

[0049] See also Figure 3 , which is a schematic diagram of the power converter of the present invention in the second operation mode. Figure 3As shown, based on the third switch S3 being turned on and the fourth switch S4 being turned on, the energy stored in the second capacitor C2 stores energy in the inductor L1 (the second energy storage path Ps2 shown in the figure), and the voltage across the inductor L1 is the second voltage V2. Based on the fourth switch S4 being turned off and the third switch S3 remaining turned on, the energy stored in the inductor L1 is released to the first capacitor C1 (the second energy release path Pr2 shown in the figure), thereby establishing a first voltage V1 on the first capacitor C1. In the second operation mode, the power converter can realize the second capacitor C2 transferring energy to the first capacitor C1 and stabilizing the voltage of the first capacitor C1. In one embodiment, the conditions for the power converter 10 to perform the second operation mode include: E2>E3>E1; and at least one of 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 by a synchronous rectification switch or a diode.

[0050] See also Figure 4 , which is a schematic diagram of the power converter of the present invention in the third operation mode. Figure 4 As shown, based on the third switch S3 being turned on and the fourth switch S4 being turned on, the energy stored in the second capacitor C2 stores energy in the inductor L1 (the third energy storage path Ps3 shown in the figure), and the voltage across the inductor L1 is the second voltage V2. Based on the third switch S3 being turned off and the fourth switch S4 being kept turned on, the energy stored in the inductor L1 is released to the third capacitor C3 (the third energy release path Pr3 shown in the figure), thereby establishing a third voltage V3 on the third capacitor C3. In the third operation mode, the power converter can realize the energy transfer from the second capacitor C2 to the third capacitor C3 and stabilize the voltage of the third capacitor C3. In one embodiment, the conditions for the power converter 10 to perform the third operation mode include: E2>E1>E3; and at least one of 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 by a synchronous rectification switch or a diode.

[0051] See also Figure 5 , which is a schematic diagram of the power converter of the present invention in the fourth operation mode. Figure 5As shown, based on the conduction of the second switch S2, the energy stored in the third capacitor C3 stores energy in the inductor L1 (the fourth energy storage path Ps4 shown in the figure), and the voltage across the inductor L1 is the third voltage V3. Based on the turn-off of the second switch S2, the energy stored in the inductor L1 is released to the second capacitor C2 (the fourth energy release path Pr4 shown in the figure), so that the second voltage V2 is established on the second capacitor C2. This power converter can realize the third capacitor C3 to transfer energy to the second capacitor C2 and stabilize the voltage of the second capacitor C2 in the fourth operation mode. In one embodiment, the conditions for the power converter 10 to perform the fourth operation mode include: E3>E1>E2; and at least one of 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 by a synchronous rectification switch or a diode.

[0052] See also Figure 6 , which is a schematic diagram of the power converter of the present invention in the fifth operation mode. Figure 5 As shown, based on the third switch S3 being turned on and the fourth switch S4 being turned on, the energy stored in the second capacitor C2 stores energy in the inductor L1 (the fifth energy storage path Ps5 shown in the figure), and the voltage across the inductor L1 is the second voltage V2. Based on the third switch S3 being turned off and the fourth switch S4 being turned off, 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 shown in the figure), so that 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 the voltage magnitude of V1+V2+V3 is established on the series path of the three capacitors. This third capacitor energy transfer operation mode can realize the second capacitor C2 transferring energy 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 one 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, because the third energy release path Pr3 passes through the body diode of the first switch S1 and the body diode of the second switch S2, the first switch S1 and the second switch S2 can be replaced by synchronous rectification switches or diodes.

[0053] See also Figure 7 , which is a schematic diagram of the power converter of the present invention in the sixth operation mode. Figure 7As shown, 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 are used to 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 magnitude of the voltage 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, a second voltage V2 is established across the second capacitor C2. This sixth operation mode of capacitor energy transfer can achieve the transfer of energy from 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 one 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.

[0054] Please refer to Figure 8 As shown, it is a circuit diagram of a power converter according to the second embodiment of the present invention. Figure 8 The second embodiment shown and Figure 1 The biggest difference between the first embodiment shown is that the second embodiment is a multi-capacitor stacked (i.e., multi-capacitor series-connected) architecture. In this embodiment, the multi-capacitor series 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 a first voltage V1 of multiple voltages (such as voltages V 11 , V 12 ) and includes a plurality of first capacitors C 11 , C 12 connected in series with each other. The second capacitor string is connected between the first output terminal OUT1 and the second output terminal OUT2 and is configured to establish a second voltage V2 of multiple voltages (such as voltages V 21 , V 22 ) and includes a plurality of second capacitors C 21 , C 22 connected in series with each other. The third capacitor string is connected between the second input terminal IN2 and the second output terminal OUT2 and is configured to establish a third voltage V3 of multiple voltages (such as voltages V 31 , V 32 ) and includes a plurality of third capacitors C 31 , C 32In this circuit architecture, the power source 11 is 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. Fig. 9 , which is a circuit diagram of a power converter 30 according to a third embodiment of the present invention. In this embodiment, the power source 11 may be an AC power source, so the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are back-to-back bidirectional switches, so that for the different polarities of the positive and negative half-cycles of the AC power source, the purpose of adjusting the capacitor voltage can be achieved through the bidirectional conduction characteristics of the back-to-back bidirectional switches.

[0055] See also Fig.10 FIG. 4 is a circuit diagram of a power converter 40 according to a fourth embodiment of the present invention. Figure 1 The biggest difference between the first embodiment shown is that the power converter of the fourth embodiment has two switch modules, namely the first switch module 12-1 and the second switch module 12-2, and the number of capacitor units C1, C2, C3, C4 is four, which means that there is an additional fourth capacitor C4. 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 a plurality of voltages. Among the plurality of loads, a fourth load 94 is connected between the third output terminal OUT3 and the second input terminal IN2.

[0056] See also Fig.11 , which is a circuit diagram of a power converter 50 according to a fifth embodiment of the present invention. Fig.11 The power converter 50 shown is coupled between the power source 11 and a plurality of loads (including a first load 91, a second load 92, a third load 93 and a fourth load 94), and 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.

[0057] Fig.11 The power converter 50 shown also 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 rectification switches.

[0058] Fig.11 The power converter 50 shown also 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.

[0059] Among them, 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.

[0060] In different embodiments, the power supply 11 may be an AC power supply, and therefore 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.

[0061] See also Fig.12As shown, it 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 a first power supply 51, connected between the first input terminal IN1 and the first output terminal OUT1. One of the multiple loads serves as a second power supply 52, connected between the first output terminal OUT1 and the second output terminal OUT2. One of the multiple loads serves as a 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. Among them, the first power supply 51 and the first capacitor C1 can be batteries, such as but not limited to supercapacitors or lithium batteries or lead-acid batteries. Similarly, the second power supply 52 and the second capacitor C2 and 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, a bidirectional power flow can be achieved, the battery voltage is stabilized for charging and discharging, and the power supply 11 (ie, the load 90) is provided.

[0062] See also Fig.13 As shown, it is a flow chart of the power conversion method of the present invention. It is explained in conjunction with one of the embodiments of the above-mentioned different power converters. 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 the voltage of multiple loads to determine whether to perform one of the first operation mode to the sixth operation mode (step S10). Then, according to one of the first operation mode to the sixth operation mode, the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are controlled to be turned on and off, so that the inductor L1 is energy storage or energy release, thereby respectively establishing a first voltage V1, a second voltage V2 and a third voltage V3) for multiple loads (step S20).

[0063] Wherein, in the first operation 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.

[0064] In the second operation 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 to establish 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 to establish a first voltage V1 on the first capacitor C1.

[0065] Among them, in the third operation 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 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 releases energy to the third capacitor C3 to establish a third voltage V3 on the third capacitor C3.

[0066] Among them, in the fourth operation 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.

[0067] Among them, in the fifth operation mode, the steps are included: 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 to establish 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, so as to establish 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.

[0068] In the sixth operation 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 energy in the second capacitor C2 and the energy in the third capacitor C3 store energy in the inductor L1, so as to establish 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 releases energy to the second capacitor C2, so as to establish a second voltage V2 on the second capacitor C2.

[0069] In summary, the present invention has the following features and advantages:

[0070] 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.

[0071] 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.

[0072] The above description is only a detailed description and drawings of the preferred specific embodiments of the present invention, but the features of the present invention are not limited thereto and are not used to limit the present invention. The entire 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 field 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, 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 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, comprising 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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