Power transmission system and charging power supply converter

Abstract

A power transmission system and a charging power supply converter relate to the technical field of power supply. The power transmission system comprises a voltage reduction module and a multi-output DC-DC conversion module. The voltage reduction module comprises a voltage input end, a first power supply input end and a second power supply input end; the voltage input end is used for acquiring an input voltage so as to reduce the input voltage and generate a power supply voltage; a power supply voltage supplies power to a battery connected with the power transmission system through the first power supply input end; the second power supply input end is used for outputting node voltage. The multi-output DC-DC conversion module comprises an inductor and at least two output circuits, and the first end of the inductor is connected with the second power supply input end to obtain node voltage; and the input end of each output circuit is connected with the second end of the inductor and is used for carrying out voltage conversion on the node voltage so as to generate corresponding load voltage, and the load voltage supplies power to a load connected with the corresponding output circuit through the output end of the output circuit.

Description

Technical Field

[0001] The present invention relates to the field of power supply technology, and in particular to a power transmission system and a charging power supply converter. Background Art

[0002] In recent years, people have been increasing their demands for the performance and functions of portable electronic products such as mobile phones, tablets and laptops, and have also put forward higher and higher requirements for their charging speed, battery life and portability. In particular, the continuous upgrading of the power transmission protocol (Power Delivery, referred to as PD) has covered a higher voltage range to reduce the loss on the charging line, and provided functions such as adjustable voltage to make the charging process more flexible. However, higher input voltage also brings greater switching losses. In addition, the traditional power supply architecture often uses multiple discrete modules and multi-stage step-down to power the low-voltage load end. Taking a laptop as an example, first a charging chip is required to convert the charging line voltage to about 12V for charging its three-cell lithium battery, and then use multiple high-step-down converters to convert the 12V voltage rail to the low-voltage load end. This solution not only brings higher packaging costs and PCB area, but also limits the overall conversion efficiency and power density. Although the academic community has proposed some advanced converter topologies in recent years to achieve high-density charging and high-efficiency and high-step-down voltage conversion, the performance of the overall solution is still subject to the power supply architecture itself. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a power transmission system with higher power density and lower hardware cost and a charging and power supply converter integrating charging and power supply.

[0004] According to a first aspect, an embodiment provides a power transmission system, comprising:

[0005] A step-down module, the step-down module comprising a voltage input terminal, a first power supply input terminal and a second power supply input terminal; the voltage input terminal is used to obtain an input voltage to step down the input voltage to generate a power supply voltage; the power supply voltage is supplied to the battery connected to the power transmission system through the first power supply input terminal; the second power supply input terminal is used to output a node voltage;

[0006] A multi-output DC-DC conversion module, the multi-output DC-DC conversion module includes an inductor and at least two output circuits, the first end of the inductor is connected to the second power supply input end to obtain the node voltage; the input end of each output circuit is connected to the second end of the inductor, and is used to perform voltage conversion on the node voltage to generate a corresponding load voltage, and the load voltage supplies power to the load connected to the corresponding output circuit through the output end of the output circuit.

[0007] In one embodiment, each output circuit includes a switched capacitor voltage converter, and each output circuit uses the switched capacitor voltage converter to step down the node voltage to generate a load voltage corresponding to each output circuit.

[0008] In one embodiment, the switched capacitor voltage converter includes a switch tube module and a capacitor module, and the switch tube module is switched on and off in response to a control signal to realize the series connection of the load and the inductor, or to realize the switching of the load and the capacitor module in parallel.

[0009] In one embodiment, the switch module includes a switch tube S9, a switch tube S11, a switch tube S13 and a switch tube S15, and the capacitor module includes a capacitor C3 and a capacitor C 01 The first end of the switch tube S9 is connected to the input end of the output circuit, the second end of the switch tube S9 is connected to the first end of the switch tube S11, the second end of the switch tube S11 is connected to the first end of the switch tube S13, the second end of the switch tube S13 is connected to the first end of the switch tube S15, and the second end of the switch tube S15 is grounded; the first end of the capacitor C3 is connected to the second end of the switch tube S9, the second end of the capacitor C3 is connected to the first end of the switch tube S15; the second end of the switch tube S11 is used to output the load voltage, and the second end of the switch tube S11 is also connected to the capacitor C 01 The first end of the capacitor C 01 The second end is grounded.

[0010] In one embodiment, the voltage reduction module includes a switched capacitor converter, the switched capacitor converter includes a plurality of switches, and each switch in the switched capacitor converter is turned on and off in response to a control signal to perform pulse width modulation on the node voltage.

[0011] According to a second aspect, an embodiment provides a charging power supply converter, including a power transmission system, wherein the power transmission system includes:

[0012] A step-down module, the step-down module comprising a voltage input terminal, a first power supply input terminal and a second power supply input terminal; the voltage input terminal is used to obtain an input voltage to step down the input voltage to generate a power supply voltage; the power supply voltage is supplied to the battery connected to the power transmission system through the first power supply input terminal; the second power supply input terminal is used to output a node voltage;

[0013] A multi-output DC-DC conversion module, the multi-output DC-DC conversion module includes an inductor and at least two output circuits, the first end of the inductor is connected to the second power supply input end to obtain the node voltage; the input end of each output circuit is connected to the second end of the inductor, and is used to perform voltage conversion on the node voltage to generate a corresponding load voltage, and the load voltage supplies power to the load connected to the corresponding output circuit through the output end of the output circuit.

[0014] In one embodiment, each output circuit includes a switched capacitor voltage converter, and each output circuit uses the switched capacitor voltage converter to step down the node voltage to generate a load voltage corresponding to each output circuit.

[0015] In one embodiment, the switched capacitor voltage converter includes a switch tube module and a capacitor module, and the switch tube module is switched on and off in response to a control signal to realize the series connection of the load and the inductor, or to realize the switching of the load and the capacitor module in parallel.

[0016] In one embodiment, the switch module includes a switch tube S9, a switch tube S11, a switch tube S13 and a switch tube S15, and the capacitor module includes a capacitor C3 and a capacitor C 01 The first end of the switch tube S9 is connected to the input end of the output circuit, the second end of the switch tube S9 is connected to the first end of the switch tube S11, the second end of the switch tube S11 is connected to the first end of the switch tube S13, the second end of the switch tube S13 is connected to the first end of the switch tube S15, and the second end of the switch tube S15 is grounded; the first end of the capacitor C3 is connected to the second end of the switch tube S9, the second end of the capacitor C3 is connected to the first end of the switch tube S15; the second end of the switch tube S11 is used to output the load voltage, and the second end of the switch tube S11 is also connected to the capacitor C 01 The first end of the capacitor C 01 The second end is grounded.

[0017] In one embodiment, the voltage reduction module includes a switched capacitor converter, the switched capacitor converter includes a plurality of switches, and each switch in the switched capacitor converter is turned on and off in response to a control signal to perform pulse width modulation on the node voltage.

[0018] According to a power transmission system and a charging power supply converter of the above-mentioned embodiment, the power transmission system includes a step-down module, an inductor and a multi-output DC-DC conversion module. The charging output end of the step-down module is used to charge the battery, the power supply output end of the step-down module is connected to the first end of the inductor, and the second end of the inductor is connected to the input end of each output circuit in the multi-output DC-DC converter, and the output end of each output circuit is used to power the load connected to the corresponding output circuit. In the power transmission system provided in the present application, the step-down module of the charging stage and the low-voltage load power supply stage is reused at the first end of the inductor, and the charging function and the power supply function are combined in the step-down module, thereby saving hardware costs and passive device expenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A circuit diagram of a hybrid switched capacitor topology of a charging power converter in an embodiment;

[0020] Figure 2 A schematic diagram of the structure of a power transmission system in an embodiment;

[0021] Figure 3 A circuit diagram of a switched capacitor converter in one embodiment;

[0022] Figure 4 A schematic diagram of the structure of a switched capacitor voltage converter in an embodiment;

[0023] Figure 5 is a circuit diagram of a switched capacitor voltage converter in one embodiment;

[0024] Figure 6 is a schematic diagram of state 1 of a power transmission system in an embodiment;

[0025] Figure 7 is a schematic diagram of state 2 of a power transmission system in an embodiment;

[0026] Figure 8 is a schematic diagram of state 3 of a power transmission system in an embodiment;

[0027] Fig. 9 is a schematic diagram of state 4 of a power transmission system in one embodiment;

[0028] Fig.10 A parameter waveform diagram of steady-state operation in a power transmission system in an embodiment;

[0029] Fig.11 It is a structural schematic diagram of a charging power supply converter in another embodiment;

[0030] Fig.12 FIG. 4 is a schematic diagram of the operation of a power transmission system according to a specific embodiment. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0032] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0033] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0034] Please refer to Figure 1 In one embodiment, a hybrid switched capacitor topology is used in the charging power converter. Figure 1It is a reconfigurable dual-path hybrid DC-DC converter, the basic principle of which is to use flying capacitors C31 and C32 to form a DC path in parallel with inductor L11 in a certain working state to reduce the DC current of inductor L11. Since the energy density of off-chip power capacitors is much greater than that of power inductors (the flying capacitors C33, flying capacitors C32 and inductor L11 in the dual-path hybrid DC-DC converter are all off-chip capacitors and off-chip inductors), the dual-path hybrid DC-DC converter can use smaller capacitors and inductors to increase power density. However, since the DC current reduction effect of the inductor in the converter is strongly related to the voltage conversion ratio, the converter uses a reconfigurable method to reconstruct different topological structures under different voltage conversion ratios to achieve a reduction in the inductor current level within a wide voltage range. Despite this, the reconstruction process can easily lead to output instability. In addition, finding an optimal critical point for reconstruction itself is also a complex problem.

[0035] The present application provides a power transmission system, which combines the charging function and the power supply function into one switched capacitor converter by multiplexing the switched capacitor converters of the charging stage and the low-voltage load power supply stage, thereby saving hardware costs and the overhead of passive components. In addition, the multi-output DC-DC conversion module proposed in the present application utilizes the alternating operation of the capacitor modules of each output circuit to achieve the optimal inductive DC current reduction effect in a single mode that is independent of the conversion ratio, so that the DC-DC conversion module can continuously output current, and eliminates the convergence effect of current on the power switch, further improving the overall power density, which is described in detail below.

[0036] Please refer to Figure 2 In one embodiment, a power transmission system 100 provided in the present application includes a step-down module 110 and a multi-output DC-DC conversion module 120 .

[0037] In one embodiment, the voltage reduction module 110 includes a voltage input terminal, a first power supply input terminal, and a second power supply output terminal. The voltage input terminal obtains an input voltage V BUS The first power supply input terminal is used to charge the lithium battery connected to the power transmission system 100, and the second power supply input terminal is used to output the node voltage.

[0038] In one embodiment, the buck module 110 includes a switched capacitor converter, which includes a plurality of switches. Each switch in the switched capacitor converter is turned on and off in response to a control signal to perform pulse width modulation on each node voltage.

[0039] It should be noted that the switched capacitor converter uses an N:1 switched capacitor converter, and the N:1 switched capacitor converter realizes voltage conversion by charging and discharging the capacitor. N:1 represents the conversion ratio, which refers to the ratio of the input voltage converted to the output voltage. For example, if N=2, the output voltage will be half of the input voltage. The conversion ratio of the switched capacitor converter is not limited in this application. According to actual practical needs, the switched capacitor converter can select the corresponding conversion ratio.

[0040] Please refer to Figure 3 In one embodiment, the switched capacitor converter in the present application includes a switch tube S1, a switch tube S3, a switch tube S5, a switch tube S7, a capacitor C1, a switch tube S2, a switch tube S4, a switch tube S6, a switch tube S8, a capacitor C2 and a capacitor C OHV . The first end of the switch tube S1 is connected to the voltage input end, the second end of the switch tube S1 is connected to the first end of the switch tube S3, the second end of the switch tube S3 is connected to the first end of the switch tube S5, the second end of the switch tube S5 is connected to the first end of the switch tube S7, and the second end of the switch tube S7 is grounded. The first end of the capacitor C1 is connected to the second end of the switch tube S1, and the second end of the capacitor C1 is connected to the first end of the switch tube S7. The first end of the switch tube S2 is also connected to the voltage input end, the second end of the switch tube S2 is connected to the first end of the switch tube S4, the second end of the switch tube S4 is connected to the first end of the switch tube S6, the second end of the switch tube S6 is connected to the first end of the switch tube S8, and the second end of the switch tube S8 is grounded. The first end of the capacitor C2 is connected to the second end of the switch tube S2, and the second end of the capacitor C2 is connected to the first end of the switch tube S8. The second end of the switch tube S3 is also connected to the second end of the switch tube S4, and the second end of the switch tube S3 and the second end of the switch tube S4 are connected to the capacitor C OHV The first end of the capacitor C OHV The second end of is a first power supply input end, used to supply power to the battery connected to the power transmission system. The second end of capacitor C2 is a second power supply input end, used to output the node voltage.

[0041] It should be noted that the switch tube S1, the switch tube S3, the switch tube S5 and the switch tube S7 are switched on and off in response to the control signal, thereby adjusting the flow of the charge in the capacitor C1, determining when the charge in the capacitor C1 is charged and discharged, and thus controlling the voltage conversion. Among them, the switch tube S1, the switch tube S3, the switch tube S5 and the switch tube S7 work in a sequential or time-division multiplexing manner, and switch the state within a certain time period. For example, in the first half of a cycle, the switch tube S1 and the switch tube S5 are closed and the switch tube S3 and the switch tube S7 are disconnected, so that the capacitor C1 is charged, and in the second half of a cycle, the switch tube S1 and the switch tube S5 are disconnected and the switch tube S3 and the switch tube S7 are closed, so that the capacitor C1 is discharged.

[0042] Similarly, the switch tubes S2, S4, S6 and S8 work in a sequential or time-division multiplexing manner. In the first half of a cycle, the switch tubes S2 and S6 are closed and the switch tubes S4 and S8 are disconnected, so that the capacitor C2 is charged. In the second half of a cycle, the switch tubes S2 and S6 are disconnected and the switch tubes S4 and S8 are closed, so that the capacitor C2 is discharged.

[0043] The power transmission system 100 provided in the present application utilizes the adjustable voltage function in the power transmission protocol of version 3.1 and above (the power transmission protocol of version 3.1 and above specifies the output voltage range and power range), and adjusts the input voltage in real time to supply power to the capacitor C OHV The second end of the capacitor C2 provides a charging voltage for the lithium battery, and at the same time generates a node voltage V that can be pulse-width modulated at the second end of the capacitor C2. SWH , to provide to the multi-output DC-DC conversion module 120. In addition, the buck module 110 in the power transmission system 100 uses the capacitor topology in the switched capacitor converter to replace the inductor in the traditional power conversion circuit, and realizes energy transmission and conversion through the charging and discharging of the capacitor. In the present application, removing the inductor in the switched capacitor converter can reduce the volume and cost of the switched capacitor converter, and can also improve the power density of the power transmission system 100.

[0044] In one embodiment, the multi-output DC-DC conversion module 120 includes an inductor 121 and at least two output circuits 122. A first end of the inductor 121 is connected to a second power supply input end to obtain a node voltage V SWH The input end of each output circuit 122 is connected to the second end of the inductor 121, which is used to convert the node voltage V SWH Voltage conversion is performed to generate a corresponding load voltage, and the load voltage supplies power to a load connected to the corresponding output circuit 122 through the output end of the output circuit.

[0045] In one embodiment, the output circuit 122 includes a switched capacitor voltage converter, and the switched capacitor voltage converter includes an N:1 switched capacitor voltage converter. Each output circuit 122 can use a different ratio of N:1 switched capacitor voltage converters, and the ratio of the switched capacitor voltage converters of each output circuit can be set according to actual needs. Each output circuit 122 uses a switched capacitor voltage converter to convert the node voltage V SWH The voltage is stepped down to generate a load voltage corresponding to each output circuit 122 .

[0046] Please refer to Figure 4In one embodiment, the switched capacitor voltage converter includes a switch module and a capacitor module, and the switch module is switched on and off in response to a control signal to realize a series connection between the load and the inductor 121, or to realize a switching between a parallel connection between the load and the capacitor module.

[0047] In one embodiment, the number of output circuits in the multi-output DC-DC conversion module 120 can be set accordingly according to different requirements of actual engineering practice. The multi-output DC-DC conversion module 120 in the present application includes two output circuits, namely a first output circuit 122a and a second output circuit 122b, and both the first output circuit 122a and the second output circuit 122b use a 2:1 switched capacitor voltage converter.

[0048] Please refer to Figure 5 In one embodiment, the switch module in the first output circuit 122a includes a switch tube S9, a switch tube S11, a switch tube S13 and a switch tube S15, and the capacitor module in the first output circuit 122a includes a capacitor C3 and a capacitor C 01 The first end of the switch tube S9 is the input end of the first output circuit 122a, the second end of the switch tube S9 is connected to the first end of the switch tube S11, the second end of the switch tube S11 is connected to the first end of the switch tube S13, the second end of the switch tube S13 is connected to the first end of the switch tube S15, and the second end of the switch tube S15 is grounded. The first end of the capacitor C3 is connected to the second end of the switch tube S9, the second end of the capacitor C3 is connected to the first end of the switch tube S15. The second end of the switch tube S11 is the second end of the third switch module 131a, the second end of the switch tube S11 is connected to the capacitor C 01 The first end of the capacitor C 01 The first end of the capacitor C is the output end of the first output circuit 122a. 01 The second end is grounded.

[0049] Please refer to Figure 5 In one embodiment, the switch module in the second output circuit 122b includes switch tube S10, switch tube S12, switch tube S14 and switch tube S16, and the capacitor module in the second output circuit 122b includes capacitor C4 and capacitor C 02 The first end of the switch tube S10 is the input end of the second output circuit 122b, the second end of the switch tube S10 is connected to the first end of the switch tube S12, the second end of the switch tube S12 is connected to the first end of the switch tube S14, the second end of the switch tube S14 is connected to the first end of the switch tube S16, and the second end of the switch tube S16 is grounded. The first end of the capacitor C4 is connected to the second end of the switch tube S10, and the second end of the capacitor C4 is connected to the first end of the switch tube S16. The second end of the switch tube S12 is the second end of the third switch module 131b, and the second end of the switch tube S12 is connected to the capacitor C02 The first end of the capacitor C 02 The first end of the capacitor C is the output end of the second output circuit 122b. 02 The second end is grounded.

[0050] It should be noted that the multi-output DC-DC conversion module 120 can generate multiple low voltages, wherein the first output circuit 122a and the second output circuit 122b respectively generate low voltages to the capacitor C 01 and capacitor C 02 , to supply the load connected to the power transmission system 100.

[0051] The power transmission system of the present application uses a 2:1 switched capacitor converter and a hybrid single-inductor dual-output DC-DC converter (i.e., a multi-output DC-DC conversion module). The 2:1 switched capacitor converter is responsible for converting the 15-28V adjustable voltage range defined in the power transmission protocol version 3.1 and above into a voltage of 8.4-12.6V to charge the three-cell lithium battery. The hybrid single-inductor dual-output DC-DC converter converts the switch node voltage V SWH The hybrid single-inductor dual-output DC-DC converter forms a 2V 01 or 2V 02 The low voltage of the inductor can halve the DC current of the inductor under any conversion ratio. In addition, due to the alternating operation of the flying capacitor C3 and the flying capacitor C4, there can be at least one power supply path of the inductor 120 or the flying capacitor in the first output circuit 122a and the second output circuit 122b, which ensures the continuity of the output current of the first output circuit 122a and the second output circuit 122b, and reduces the output ripple and the corresponding output capacitor capacitance requirements. In addition, during the operation of the hybrid single-inductor dual-output DC-DC converter, there is no parallel connection between the inductor 120 and the flying capacitor C3 / flying capacitor C4, so there is no effect of current convergence on the power switch, which further reduces the conduction loss and output ripple of the power switch.

[0052] Please refer to Figure 6-Figure 9 In one embodiment, Figures 6 to 9 Specifically describe the working mode of one implementation of the circuit connection diagram of the power transmission system provided by the present application. S Including Figure 6 Status 1. Figure 7 Status 2, Figure 8 State 3 and Fig. 9The four states of state 1-state 2-state 3-state 4 are used as a complete cycle. For the inductor 121, state 1 and state 2 are two magnetization states, during which the current of the inductor 121 increases, and state 3 and state 4 are two demagnetization states, during which the current of the inductor 121 decreases. For the two low-voltage outputs, V O1 In state 2 and state 3, it is connected in series with the flying capacitor C3 and the inductor 121 to obtain the current directly from the inductor 121; in state 1 and state 4, it is connected in parallel with the flying capacitor C3 to obtain the current from C3. O2 In state 1 and state 4, it is connected in series with the flying capacitor C4 and the inductor 121 to obtain the current directly from the inductor 121; in state 2 and state 3, it is connected in parallel with the flying capacitor C4 to obtain the current from C4. For the output on the high-voltage side used to charge the three-cell lithium battery, its voltage mainly depends on the input voltage V BUS The adjustable voltage function provided by the PD3.1 protocol can be used to adjust the input voltage V BUS Real-time adjustment to meet the charging needs of lithium batteries.

[0053] It should be noted that in any working state, the right end of the inductor 121 is always 2V 01 or 2V 02 , for the same power transmission, the DC current of inductor 121 can be halved, which is equivalent to reducing the power consumption of the DC resistance of inductor 121 to 1 / 4 of the traditional solution. Therefore, the power transmission system in this application can use an inductor with a large DC resistance but a small volume to improve the overall power density. That is:

[0054]

[0055] Among them, I L,DC represents the DC current of the inductor 121, I O1 Indicates that 2V in the first output circuit 122a O1 The corresponding current, I O2 Indicates that 2V in the second output circuit 122b O2 The corresponding current.

[0056] In one embodiment, Fig.10 : is a waveform diagram of each voltage and current in the power transmission system 100 when working in a steady state, wherein Φ1, Φ2, Φ3 and Φ4 represent state 1, state 2, state 3 and state 4 respectively, V SWH is the switch node voltage at the left end of the inductor 121, V SWL is the voltage at the right end of the inductor 121, I L represents the current of the inductor 121, I C3 Represents the current of capacitor C3, IC4 Represents the current of capacitor C4. For the low-voltage output of each output circuit, a flying capacitor and a low-voltage output are alternately connected in series and parallel. O1 When the flying capacitor C3 is connected in series, the inductor 121 is also connected in series with it, and the current of the inductor 121 is smoothly transferred to the capacitor C just like a normal Buck converter. 01 At the same time, the inductor 121 also stores part of the energy in the flying capacitor C3 connected in series with it. O2 When connected in series, V O2 The inductor 121 receives the current provided by the inductor 121, so the inductor 121 can no longer supply current to V O1 Provide current, at this time, the flying capacitor C3 that has been charged in the previous state is connected to V O1 parallel, and to V O1 Provide current. In this alternating operation, it can be ensured that any low-voltage output has current provided by the inductor or flying capacitor in any state, ensuring the continuity of current to the two output ends, reducing the output voltage ripple and the corresponding output capacitor requirements. In addition, in any state, for any output end, there is also one and only one current transmission path, and there is no situation where the inductor and flying capacitor currents converge on one switch, which further ensures lower switch conduction losses.

[0057] In one embodiment, a 2:1 switched capacitor converter with a 180-degree phase shift is used in the switched capacitor converter of the present application, and a voltage V SWH Only the circuits where the switch tubes S2, S4, S6, S8 and capacitor C2 are located are needed, so the switch tubes S1, S3, S5, S7 and capacitor C1 can work independently with a 50% duty cycle without being restricted by the low-voltage load effect and PWM modulation. In addition, in the multi-output DC-DC conversion module 120, since the inductor 121 separates the high-voltage and low-voltage voltage domains, all low-voltage switches with good quality can be used on the low-voltage side, thereby improving the overall conversion efficiency and power density.

[0058] Please refer to Fig.11 Another embodiment further provides a charging power supply converter 10 , which includes a power transmission system 100 , and the power transmission system 100 includes a step-down module 110 and a multi-output DC-DC conversion module 120 .

[0059] In one embodiment, the voltage reduction module 110 includes a voltage input terminal, a first power supply input terminal, and a second power supply output terminal. The voltage input terminal obtains an input voltage V BUSThe first power supply input terminal is used to charge the lithium battery connected to the power transmission system 100, and the second power supply input terminal is used to output the node voltage. The buck module 110 includes a switched capacitor converter, and the switched capacitor converter includes a plurality of switches. Each switch in the switched capacitor converter is turned on and off in response to a control signal to perform pulse width modulation on each node voltage.

[0060] In one embodiment, the multi-output DC-DC conversion module 120 includes an inductor 121 and at least two output circuits 122. A first end of the inductor 121 is connected to a second power supply input end to obtain a node voltage V SWH The input end of each output circuit 122 is connected to the second end of the inductor 121, which is used to convert the node voltage V SWH Voltage conversion is performed to generate a corresponding load voltage, and the load voltage supplies power to a load connected to the corresponding output circuit 122 through the output end of the output circuit.

[0061] In one embodiment, the switched capacitor voltage converter includes a switch module and a capacitor module, and the switch module is switched on and off in response to a control signal to achieve series connection of the load and the inductor 121, or to achieve switching of the load and the capacitor module in parallel.

[0062] It should be noted that the power transmission system 100 in the charging power converter 10 has been clearly explained in the embodiment of the power transmission system 100 and will not be described again here.

[0063] Please refer to Fig.12 , the working process of the power transmission system 100 of the present application is described with a specific embodiment. In addition to the power transmission system 100, it also includes a gate driver 11, a control module 12, a non-overlapping clock generator 13 and a controller 14. Taking the branch where the switch S22, the switch S24, the switch S26, the switch S28 and the capacitor C22 are located as an example, there are two working states in total. In one state, the switch S22 and the switch S26 are turned on, the switch S24 and the switch S28 are turned off, and the input terminal VIN charges the capacitor C22. The output voltage of the high-voltage charging side is:

[0064] V CHG =V IN -V C22

[0065] In another state, the switch S24 and the switch S28 are turned on, the switch S22 and the switch S26 are turned off, and the capacitor C2 discharges to the high-voltage charging side output capacitor, which is:

[0066] V CHG =V C22

[0067] therefore:

[0068]

[0069] A similar conclusion is obtained for the branch where capacitor C21 is located:

[0070]

[0071] From the above, it can be obtained that the output voltage on the high-voltage charging side is half of the input voltage. Since the voltage range of the three-cell lithium battery in the laptop is 8.4-12.6V, even considering certain losses, the 15-28V input voltage provided by the adjustable voltage function in the PD 3.1 protocol is sufficient to cover this range. It should be noted that since this application shares the switch node on the high-voltage charging side, the inductor power supply circuit connected to the inductor needs to meet the pulse width modulation requirements of the low-voltage end for the switch node. However, the battery power supply circuit that is not connected to the inductor can still operate at a 50% duty cycle, and can also operate at different frequencies.

[0072] The charging voltage generation process of the low-voltage side of the power transmission system 100 is mainly determined by the volt-second balance of the inductor L22 and the load size of the load end. Specifically, the voltage V SWH The amplitude and duty cycle of will affect the energy stored in the inductor per cycle, and the time of access to each output in a single cycle is determined by the charge demand of each output terminal, that is, the load current. Therefore, if peak current mode control is adopted, the control module 12 will collect the current from the inductor L22 and the two output voltages V O21 and V O22 information, in order to maintain the two output voltages V O21 and V O22 Stable, generating CLK H and CLK L Two control clock signals are used to adjust the on-time of each switch to ensure V O21 and V O22 Stable. CLK H Responsible for controlling the switch of the branch connecting the high voltage end and the inductor L22, CLK L Responsible for controlling the low-voltage side switch. The two clock control signals are then used by the non-overlapping clock generator to generate 16 clock signals, which then pass through the corresponding level shifter and gate driver 11 to control the 16 power switches of the power stage. The specific power stage behavior is as follows: L When V O21 The switches S29 and S33 on the side are turned on, the switches S31 and S35 are turned off, and the inductor L22 charges the capacitor C23 while transferring the current to V O21 ; The other side V O22On the other side, switches S32 and S36 are turned on, switches S30 and S34 are turned off, capacitors C24 and V O22 Connect in parallel to V O22 Provides current. L When it is 0, the low voltage power stage switching action is opposite to the above.

[0073] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0074] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A power transmission system, characterized in that: include: A step-down module, the step-down module comprising a voltage input terminal, a first power supply input terminal and a second power supply input terminal; the voltage input terminal is used to obtain an input voltage to step down the input voltage to generate a power supply voltage; The power supply voltage is used to supply power to the battery connected to the power transmission system through the first power supply input terminal; the second power supply input terminal is used to output the node voltage; A multi-output DC-DC conversion module, the multi-output DC-DC conversion module includes an inductor and at least two output circuits, the first end of the inductor is connected to the second power supply input end to obtain the node voltage; the input end of each output circuit is connected to the second end of the inductor, and is used to perform voltage conversion on the node voltage to generate a corresponding load voltage, and the load voltage supplies power to the load connected to the corresponding output circuit through the output end of the output circuit.

2. The power transmission system according to claim 1, characterized in that: Each output circuit includes a switched capacitor voltage converter, and each output circuit uses the switched capacitor voltage converter to step down the node voltage to generate a load voltage corresponding to each output circuit.

3. The power transmission system according to claim 2, characterized in that: The switched capacitor voltage converter includes a switch tube module and a capacitor module. The switch tube module is switched on and off in response to a control signal to achieve series connection of the load and the inductor, or to achieve switching of the load and the capacitor module in parallel.

4. The power transmission system according to claim 3, characterized in that: The switch module includes switch tubes S9, S11, S13 and S15, and the capacitor module includes capacitors C3 and C 01 The first end of the switch tube S9 is connected to the input end of the output circuit, the second end of the switch tube S9 is connected to the first end of the switch tube S11, the second end of the switch tube S11 is connected to the first end of the switch tube S13, the second end of the switch tube S13 is connected to the first end of the switch tube S15, and the second end of the switch tube S15 is grounded; the first end of the capacitor C3 is connected to the second end of the switch tube S9, the second end of the capacitor C3 is connected to the first end of the switch tube S15; the second end of the switch tube S11 is used to output the load voltage, and the second end of the switch tube S11 is also connected to the capacitor C 01 The first end of the capacitor C 01 The second end is grounded.

5. The power transmission system according to claim 1, characterized in that: The voltage reduction module includes a switched capacitor converter, and the switched capacitor converter includes a plurality of switches. Each switch in the switched capacitor converter is switched on and off in response to a control signal to perform pulse width modulation on the node voltage.

6. A charging power supply converter, characterized in that: A power transmission system is provided, wherein the power transmission system comprises: A step-down module, the step-down module comprising a voltage input terminal, a first power supply input terminal and a second power supply input terminal; the voltage input terminal is used to obtain an input voltage to step down the input voltage to generate a power supply voltage; the power supply voltage is supplied to the battery connected to the power transmission system through the first power supply input terminal; the second power supply input terminal is used to output a node voltage; A multi-output DC-DC conversion module, the multi-output DC-DC conversion module includes an inductor and at least two output circuits, the first end of the inductor is connected to the second power supply input end to obtain the node voltage; the input end of each output circuit is connected to the second end of the inductor, and is used to perform voltage conversion on the node voltage to generate a corresponding load voltage, and the load voltage supplies power to the load connected to the corresponding output circuit through the output end of the output circuit.

7. The charging power converter according to claim 6, wherein: Each output circuit includes a switched capacitor voltage converter, and each output circuit uses the switched capacitor voltage converter to step down the node voltage to generate a load voltage corresponding to each output circuit.

8. The charging power converter according to claim 7, wherein: The switched capacitor voltage converter includes a switch tube module and a capacitor module. The switch tube module is switched on and off in response to a control signal to achieve series connection of the load and the inductor, or to achieve switching of the load and the capacitor module in parallel.

9. The charging power converter according to claim 8, characterized in that: The switch module includes switch tubes S9, S11, S13 and S15, and the capacitor module includes capacitors C3 and C 01 The first end of the switch tube S9 is connected to the input end of the output circuit, the second end of the switch tube S9 is connected to the first end of the switch tube S11, the second end of the switch tube S11 is connected to the first end of the switch tube S13, the second end of the switch tube S13 is connected to the first end of the switch tube S15, and the second end of the switch tube S15 is grounded; the first end of the capacitor C3 is connected to the second end of the switch tube S9, the second end of the capacitor C3 is connected to the first end of the switch tube S15; the second end of the switch tube S11 is used to output the load voltage, and the second end of the switch tube S11 is also connected to the capacitor C 01 The first end of the capacitor C 01 The second end is grounded.

10. The charging power converter according to claim 6, wherein: The voltage reduction module includes a switched capacitor converter, and the switched capacitor converter includes a plurality of switches. Each switch in the switched capacitor converter is switched on and off in response to a control signal to perform pulse width modulation on the node voltage.

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