Balanced isolation type hybrid charging circuit

Abstract

The utility model provides a balanced isolation type hybrid charging circuit, which comprises a lithium battery module BT1 and a high-voltage charging module, the high-voltage charging module comprises a bus inductor L1 and four sub-modules, and the four sub-modules share a bus for input parallel connection and output parallel connection. Each sub-module comprises a bus capacitor Ci, an H full-bridge unit Qi, a resonant inductor Lri, a resonant capacitor Cri and an isolation boost rectification unit Ti, i = 1, 2, 3 and 4, the positive electrode and the negative electrode of the lithium battery module are respectively connected with two input ends of the H full-bridge unit in each sub-module, and two input ends and two output ends of the four sub-modules are connected in a staggered manner. According to the utility model, a series resonance power topology and an interleaving parallel control technology are adopted, so that the high-power charging system has remarkable superiority and is suitable for a high-power charging system which has high requirements on charging precision, relatively high system safety and low requirements on battery capacity.

Description

Technical Field

[0001] The utility model relates to the field of high-voltage high-power charging, and more specifically, to a balanced isolation type hybrid charging circuit. Background Art

[0002] Due to its characteristics such as high voltage, high power, and high power density, it is difficult to implement a high-voltage high-power charging power supply. At present, the technology of high-voltage high-power charging power supplies has developed rapidly. Common power topologies include sequential series boost charging schemes, multiple BUCK charging schemes, etc.

[0003] However, these schemes have limitations to varying degrees in terms of usage cost, control accuracy, system reliability, and safety. Therefore, there is an urgent need for a new type of high-voltage high-power charging system topology scheme that can overcome the above disadvantages. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the utility model provides a balanced isolation type hybrid charging circuit, which has the advantages of high charging accuracy, high efficiency, high reliability, good load adaptability, and easy expansion, so as to meet the requirements of modern high-voltage high-power charging.

[0005] According to a first aspect of the utility model, there is provided a balanced isolation type hybrid charging circuit, including a lithium battery module BT1 and a high-voltage charging module. The high-voltage charging module includes a bus inductor L1 and four sub-modules. The four sub-modules share a DC bus input in parallel and are output in parallel. Each sub-module includes a bus capacitor Ci, an H full-bridge unit Qi, a resonant inductor Lri, a resonant capacitor Cri, and an isolation boost rectification unit Ti, where i = 1, 2, 3, 4;

[0006] The positive electrode of the lithium battery module BT1 is respectively connected to the first input end of the H full-bridge unit Qi in each sub-module through the bus inductor L1, and the negative electrode of the lithium battery module is respectively connected to the second input end of the H full-bridge unit Qi in each sub-module. A bus capacitor Ci is connected between the first input end and the second input end of the H full-bridge unit Qi in each sub-module. The first output end of the H full-bridge unit Qi in each sub-module is connected to the first end of the primary coil of the isolation boost rectification unit Ti through the resonant inductor Lri, and the second output end of the H full-bridge unit Qi in each sub-module is connected to the second end of the primary coil of the isolation boost rectification unit Ti through the resonant capacitor Cri. The first ends of the secondary coils of each isolation boost rectification unit Ti are all connected together, and the second ends of the secondary coils of each isolation boost rectification unit Ti are all connected together. The first end and the second end of the secondary coil of each isolation boost rectification unit Ti are used as the output end of the high-voltage charging module.

[0007] A balanced isolation type hybrid charging circuit provided by the present utility model adopts a series resonance power topology and an interleaved parallel control technology, has significant advantages, and is applicable to high-power charging systems with high requirements for charging accuracy, high system safety, and small battery capacity requirements. Brief Description of the Drawings

[0008] Figure 1 It is a schematic structural diagram of a balanced isolation type hybrid charging circuit provided by the present utility model. Detailed Embodiment

[0009] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model. In addition, the technical features in the various embodiments provided by the present utility model or in a single embodiment can be combined with each other arbitrarily to form a feasible technical solution. This combination is not restricted by the order of steps and / or the mode of structural composition, but must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0010] Figure 1 A balanced isolation type hybrid charging circuit provided by the present utility model, the charging circuit includes a lithium battery module BT1 and a high-voltage charging module. The high-voltage charging module includes a bus inductor L1 and four sub-modules. Among them, the four sub-modules share the bus input in parallel and the output in parallel. Each sub-module includes a bus capacitor Ci, an H full-bridge unit Qi, a resonant inductor Lri, a resonant capacitor Cri, and an isolation boost rectification unit Ti, where i = 1, 2, 3, 4. Each sub-module adopts a modular design and has a high integration level.

[0011] The positive electrode of the lithium battery module BT1 is respectively connected to the first input end of the H full-bridge unit Qi in each sub-module through the bus inductor L1. The negative electrode of the lithium battery module is respectively connected to the second input end of the H full-bridge unit Qi in each sub-module. A bus capacitor Ci is connected between the first input end and the second input end of the H full-bridge unit Qi in each sub-module. The first output end of the H full-bridge unit Qi in each sub-module is connected to the first end of the primary coil of the isolation boost rectification unit Ti through the resonant inductor Lri. The second output end of the H full-bridge unit Qi in each sub-module is connected to the second end of the primary coil of the isolation boost rectification unit Ti through the resonant capacitor Cri. The first ends of the secondary coils of each isolation boost rectification unit Ti are all connected together. The second ends of the secondary coils of each isolation boost rectification unit Ti are all connected together. The first end and the second end of the secondary coil of each isolation boost rectification unit Ti serve as the output end of the high-voltage charging module.

[0012] Each sub-module adopts a full-bridge LC series resonance power topology (hereinafter referred to as the series resonance topology). An interleaved parallel control mode is adopted among the four sub-modules, and finally they are paralleled as a whole to achieve high-power output.

[0013] The sub-module operates in a high-frequency mode and cooperates with the interleaved parallel control mode among sub-modules, which can further improve the equivalent input and output operating frequencies of the power supply.

[0014] Among them, a single lithium battery cluster is used for the lithium battery, reducing the capacity of a single set of batteries, improving the safety of the lithium battery, and improving the maintainability.

[0015] Specifically, refer to Figure 1 The lithium battery module BT1 includes a switch S0, a switch S1, and a switch S2. The positive electrode of the lithium battery module BT1 is connected to the bus inductor L1 through the switch S1. The switch S0 and the resistor R1 are connected in parallel across the switch S1. The negative electrode of the lithium battery module BT1 is connected to the second input end of the H full-bridge unit Qi in each sub-module through the switch S2.

[0016] Among them, the four sub-modules include a first sub-module, a second sub-module, a third sub-module, and a fourth sub-module. The first sub-module includes a bus capacitor C1, an H full-bridge unit Q1, a resonant inductor Lr1, a resonant capacitor Cr1, and an isolation boost rectification unit T1. The second sub-module includes a bus capacitor C2, an H full-bridge unit Q2, a resonant inductor Lr2, a resonant capacitor Cr2, and an isolation boost rectification unit T2. The third sub-module includes a bus capacitor C3, an H full-bridge unit Q3, a resonant inductor Lr3, a resonant capacitor Cr3, and an isolation boost rectification unit T3. The fourth sub-module includes a bus capacitor C4, an H full-bridge unit Q4, a resonant inductor Lr4, a resonant capacitor Cr4, and an isolation boost rectification unit T4.

[0017] The bus capacitor C1 is connected between the first input terminal and the second input terminal of the H full-bridge unit Q1 of the first sub-module. The bus capacitor C2 is connected between the first input terminal and the second input terminal of the H full-bridge unit Q2 of the second sub-module. The bus capacitor C3 is connected between the first input terminal and the second input terminal of the H full-bridge unit Q3 of the third sub-module. The bus capacitor C4 is connected between the first input terminal and the second input terminal of the H full-bridge unit Q4 of the first sub-module.

[0018] Wherein, when the switch S1 and the switch S2 are pressed, the positive pole of the lithium battery module is connected to the first end of the bus inductor L1 through the switch S1. When the switch S0 is pressed, the positive pole of the lithium battery module BT1 is connected to the first end of the bus inductor through the switch S0 and the resistor R1. The second end of the bus inductor L1 is respectively connected to the first input terminal of the H full-bridge unit Q1 in the first sub-module, the first input terminal of the H full-bridge unit Q2 in the second sub-module, the first input terminal of the H full-bridge unit Q3 in the third sub-module, and the first input terminal of the H full-bridge unit Q4 in the fourth sub-module. The negative pole of the lithium battery module BT1 is respectively connected to the second input terminal of the H full-bridge unit Q1 in the first sub-module, the second input terminal of the H full-bridge unit Q2 in the second sub-module, the second input terminal of the H full-bridge unit Q3 in the third sub-module, and the second input terminal of the H full-bridge unit Q4 in the fourth sub-module through the switch S2.

[0019] The first output terminal of the H full-bridge unit Q1 in the first sub-module is connected to the first end of the primary coil of the first isolated boost rectification unit T1 through the resonant inductor Lr1. The second output terminal of the H full-bridge unit Q1 is connected to the second end of the primary coil of the first isolated boost rectification unit T1 through the resonant capacitor Cr1.

[0020] The first output terminal of the H full-bridge unit Q2 in the second sub-module is connected to the first end of the primary coil of the second isolated boost rectification unit T2 through the resonant inductor Lr2. The second output terminal of the H full-bridge unit Q2 is connected to the second end of the primary coil of the second isolated boost rectification unit T2 through the resonant capacitor Cr2.

[0021] The first output terminal of the H full-bridge unit Q3 in the third sub-module is connected to the first end of the primary coil of the third isolated boost rectification unit T3 through the resonant inductor Lr3. The second output terminal of the H full-bridge unit Q3 is connected to the second end of the primary coil of the third isolated boost rectification unit T3 through the resonant capacitor Cr3.

[0022] The first output terminal of the H full-bridge unit Q4 in the fourth sub-module is connected to the first end of the primary coil of the fourth isolated boost rectification unit T4 through the resonant inductor Lr4. The second output terminal of the H full-bridge unit Q4 is connected to the second end of the primary coil of the first isolated boost rectification unit T4 through the resonant capacitor Cr4.

[0023] The first ends of the secondary coils of the first isolation boost rectification unit T1, the second isolation boost rectification unit T2, the third isolation boost rectification unit T3, and the fourth isolation boost rectification unit T4 are all connected together. The second ends of the secondary coils of the first isolation boost rectification unit T1, the second isolation boost rectification unit T2, the third isolation boost rectification unit T3, and the fourth isolation boost rectification unit T4 are all connected together.

[0024] The first and second ends of the secondary coils of all the isolation boost rectification units Ti serve as the output terminals of the high-voltage charging module and can supply power to the device.

[0025] When the present utility model uses the balanced isolation type hybrid charging circuit for charging, it uses the PFM control mode. By continuously adjusting the switching frequency of the switching tubes in the H full-bridge unit, the output voltage is stabilized near the preset value. The PFM control mode enables the main switching devices of the series resonance power topology to operate in the soft-switching state.

[0026] During the charging process, first set the maximum power that the battery can receive, and then the battery management system (BMS) is responsible for real-time monitoring and control of the current and voltage for charging the battery. When the output power is less than the maximum power, the power supply charges at the maximum charging current; when the output power is greater than the maximum power, the system operating frequency is reduced to make the power supply operate in the constant power mode.

[0027] An equalization isolation type hybrid charging circuit provided by an embodiment of the present utility model has the following beneficial effects:

[0028] (1) Adopting series resonance soft-switching charging, it has the characteristics of strong anti-output short-circuit ability, parallel connection ability, and high efficiency;

[0029] (2) Adopting interleaved parallel control technology, each sub-module has an independent connection path, which can disperse the load during the charging process, can greatly improve the equivalent operating frequency of the power supply, reduce the input and output current ripples, and greatly reduce the battery requirements; the power device selection is friendly;

[0030] (3) On the premise of the same charging rate, adopting lithium battery limited power charging can further reduce the discharge rate of the battery, reduce the battery capacity requirement, and reduce the battery volume and cost.

[0031] It should be noted that in the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0032] Obviously, those skilled in the art can make various modifications and variations to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalent technologies, the present utility model also intends to include these modifications and variations.

Claims

1. A balanced isolation type hybrid charging circuit, characterized in that, It includes a lithium battery module BT1 and a high-voltage charging module. The high-voltage charging module includes a bus inductor L1 and four sub-modules. The four sub-modules share a bus input in parallel and output in parallel. Each sub-module includes a bus capacitor Ci, an H full-bridge unit Qi, a resonant inductor Lri, a resonant capacitor Cri, and an isolation boost rectification unit Ti, where i = 1, 2, 3, 4; The positive electrode of the lithium battery module BT1 is respectively connected to the first input end of the H full-bridge unit Qi in each sub-module through the bus inductor L1. The negative electrode of the lithium battery module is respectively connected to the second input end of the H full-bridge unit Qi in each sub-module. A bus capacitor Ci is connected between the first input end and the second input end of the H full-bridge unit Qi in each sub-module. The first output end of the H full-bridge unit Qi in each sub-module is connected to the first end of the primary coil of the isolation boost rectification unit Ti through a resonant inductor Lri. The second output end of the H full-bridge unit Qi in each sub-module is connected to the second end of the primary coil of the isolation boost rectification unit Ti through a resonant capacitor Cri. The first ends of the secondary coils of each isolation boost rectification unit Ti are all connected together. The second ends of the secondary coils of each isolation boost rectification unit Ti are all connected together. The first end and the second end of the secondary coil of each isolation boost rectification unit Ti serve as the output end of the high-voltage charging module.

2. The balanced isolation type hybrid charging circuit according to claim 1, wherein The lithium battery module BT1 includes a switch S0, a switch S1, and a switch S2. The positive electrode of the lithium battery module BT1 is connected to the bus inductor L1 through the switch S1. The switch S0 and the resistor R1 are connected in parallel across the switch S1. The negative electrode of the lithium battery module BT1 is connected to the second input end of the H full-bridge unit Qi in each sub-module through the switch S2.

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