High-power LLC direct-current power supply device

Abstract

The utility model belongs to the field of LLC direct-current power supplies, and particularly relates to a high-power LLC direct-current power supply device, which comprises a plurality of LLC monomers which are connected in parallel, and each LLC monomer comprises a full-bridge Mosfet circuit, a resonant cavity and a diode rectifier bridge; the resonant transformers in each LLC single resonant cavity are divided into two resonant transformers, and the two resonant transformers are connected by adopting a series structure, so that the design difficulty and the overall size of the device can be reduced, meanwhile, two rectifier bridges are designed in the diode rectifier bridge, and the output sides of the two rectifier bridges are connected by adopting a series structure, so that the design difficulty and the overall size of the device can be reduced. According to the LLC module, the requirement for the voltage withstanding level of a rectifier bridge can be lowered, device type selection is facilitated, different numbers of LLC monomers can be selected for parallel connection according to actual needs, and the overall power level of the device can be improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to LLC direct current power supply technical field, specifically relates to a kind of high-power LLC direct current power supply device. BACKGROUND

[0002] With the proposal of the "double carbon" goal, hydrogen energy as a clean energy in the field of rail transit application becomes an important way to achieve zero carbon goal, compared to single stack fuel cell system used in fuel cell vehicle, hydrogen energy multi-stack hybrid system has higher power and greater energy storage capacity, more suitable for the application characteristics of rail transit, the urgent application of hydrogen energy battery proposes urgent demand for high-power, high-performance, high-efficiency isolation DCDC power supply device. LLC isolation resonant converter is widely used because of its high efficiency, but the power level of LLC isolation resonant converter currently used is relatively low, generally limited to small power application scenarios, cannot be applied to high-power scenarios. SUMMARY

[0003] To solve the technical problems in the above background art, the utility model provides a kind of high-power LLC direct current power supply device, to improve the power level of LLC isolation resonant converter, so that it can be applied to high-power scene.

[0004] To realize the above technical scheme, the utility model provides a kind of high-power LLC direct current power supply device includes: multiple parallelly connected LLC single bodies, each LLC single body includes: full-bridge Mosfet circuit, resonant cavity and diode rectifier bridge;

[0005] The resonant cavity is constituted by first capacitor Cr1, first inductor Lr1, first transformer Tm1 and second transformer Tm2 are mutually connected in series, wherein the first capacitor Cr1 is resonant capacitor;First inductor Lr1 is resonant inductor, first transformer Tm1 and second transformer Tm2 are resonant transformer;

[0006] The diode rectifier bridge includes two rectifier bridges, the input end of two rectifier bridges is respectively connected with the output end of secondary side of first transformer Tm1 and second transformer Tm2;The output end of two rectifier bridges is connected in series.

[0007] Further, the full-bridge Mosfet circuit comprises: a first input end Vin1, a second input end Vin2, a first output end Vout1 and a second output end Vout2; the first input end Vin1 is connected with the source of the first MOS tube V1 and the source of the third MOS tube V3; the drain of the first MOS tube V1 is connected with the source of the second MOS tube V2 and the first output end Vout1; the drain of the third MOS tube V3 is connected with the second output end Vout2 and the source of the fourth MOS tube; the drain of the second MOS tube is connected with the drain of the fourth MOS tube and the second input end Vin2.

[0008] Further, the rectifier bridge comprises: a first diode VD1, the positive electrode of the first diode VD1 is connected with the input Vin3 and the negative electrode of the second diode VD2; the negative electrode of the first diode VD1 is connected with the output Vout3 and the negative electrode of the third diode VD3; the positive electrode of the second diode VD2 is connected with the positive electrode of the fourth diode VD4 and the output Vout4; the negative electrode of the fourth diode VD4 is connected with the input Vin4 and the positive electrode of the third diode VD3.

[0009] Further, the device further comprises a second inductor L1, and the input ends of the plurality of LLC units are connected in parallel and then connected to the positive pole of the power supply through the second inductor L1.

[0010] Further, the device further comprises a control system, and the control system comprises: a soft start module, a reference voltage value adjustable module, a PI controller and a frequency modulation module.

[0011] The PI controller is connected with the output end of the LLC unit and the reference voltage value adjustable module, so as to obtain the voltage value U0 output by the LLC unit and the reference voltage value Uref set through the reference voltage value adjustable module, and the voltage value U0 and the reference voltage value Uref are subtracted to obtain a target frequency.

[0012] The PI controller is connected with the plurality of LLC units through the frequency soft start module, so that the frequency soft start module controls the working frequency of the plurality of LLC units to gradually increase or decrease to the target frequency based on the target frequency obtained by the PI controller, so as to achieve the purpose of adjusting the output voltage of the device.

[0013] The device has the advantages that:

[0014] (1) The utility model discloses a LLC monomer resonant cavity is divided into two through the resonant transformer, and two resonant transformers are connected with series structure, which helps to reduce the design difficulty and the overall size of the device, and two rectifier bridges are designed in the diode rectifier bridge, and the output side of two rectifier bridges is connected with series structure, which helps to reduce the requirement of rectifier bridge voltage resistance level, is more favorable to device selection, and different number of LLC monomers can be selected for parallel connection according to actual needs, which helps to improve the overall power level of the device.

[0015] (2) The inductance Lr1 is arranged before the plurality of LLC monomers connected in parallel is connected with the direct current power supply, which helps to prevent interference to the external power supply.

[0016] (3) The working frequency of the plurality of LLC monomers is controlled by the control system, so that the overall gain of the device can be changed, thereby helping to achieve the purpose of outputting different voltage values.

[0017] The advantages of the additional aspects of the utility model will be partially given in the following description, some will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the utility model form a part of the utility model and serve to provide further understanding of the utility model, and the illustrative embodiments of the utility model and the description thereof serve to explain the utility model, and do not constitute improper limitation on the utility model.

[0019] Figure 1 It is a schematic diagram of a high-power LLC direct current power supply device of the utility model.

[0020] Figure 2 It is a circuit diagram of a full-bridge Mosfet circuit of the utility model;

[0021] Figure 3 It is a circuit diagram of a diode rectifier bridge of the utility model;

[0022] Figure 4 It is a principle diagram of a control system of the utility model. DETAILED DESCRIPTION

[0023] The utility model will be further described below in combination with the drawings and embodiments.

[0024] It should be pointed out that the following detailed description is all exemplary, and aims to provide further description of the utility model. Unless otherwise specified, each technical and scientific term used in the embodiments has the same meaning as that generally understood by ordinary maintenance personnel in the technical field to which the utility model belongs.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] In this utility model, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0027] In this utility model, terms such as "fixed connection," "connected," and "joined" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For researchers or maintenance personnel in this field, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0028] Example 1:

[0029] like Figure 1 As shown, this embodiment provides a high-power LLC DC power supply device, including: multiple LLC (Inductor-Inductor-Capacitor resonant circuit) units 1, which are connected in parallel; after the multiple LLC units are connected in parallel, the input terminal is connected to the DC power supply and the output is connected to the load. The number of LLC units can be set according to actual needs, thereby helping to improve the overall power level of the device.

[0030] Each LLC unit 1 includes a full-bridge MOSFET circuit 2, a resonant cavity 3, and a diode rectifier bridge 4. The input terminal of the full-bridge MOSFET circuit is connected in parallel with the input terminals of the full-bridge MOSFET circuits in other LLC units and then connected to a DC power supply. The output terminal of the full-bridge MOSFET circuit is connected to the input terminal of the resonant cavity. The output terminal of the resonant cavity is connected to the input terminal of the diode rectifier bridge. The output terminal of the diode rectifier is connected in parallel with the output terminals of the diode rectifiers in other LLC units and then connected to the load.

[0031] like Figure 2As shown, the full-bridge Mosfet circuit 2 includes: a first input end Vin1, a second input end Vin2, a first output end Vout1 and a second output end Vout2; the first input end Vin1 is connected with the source of the first MOS tube V1 and the source of the third MOS tube V3; the drain of the first MOS tube V1 is connected with the source of the second MOS tube V2 and the first output end Vout1; the drain of the third MOS tube V3 is connected with the second output end Vout2 and the source of the fourth MOS tube; the drain of the second MOS tube is connected with the drain of the fourth MOS tube and the second input end Vin2.

[0032] The resonant cavity is composed of the first capacitor Cr1, the first inductor Lr1, the first transformer Tm1 and the second transformer Tm2 in series with each other, wherein the first capacitor Cr1 is a resonant capacitor; the first inductor Lr1 is a resonant inductor; the first transformer Tm1 and the second transformer Tm2 are resonant transformers.

[0033] In this embodiment, the first transformer Tm1 and the second transformer Tm2 are connected in series with each other, which can reduce the design difficulty and the overall volume.

[0034] As shown in the figure, Figure 3 The diode rectifier bridge 3 includes two rectifier bridges, which are referred to as the first rectifier bridge and the second rectifier bridge for the convenience of description and understanding; the input end of the first rectifier bridge is connected with the secondary side of the first transformer Tm1 and the input end of the second rectifier bridge is connected with the secondary side of the second transformer Tm2, and the output ends of the first rectifier bridge and the second rectifier bridge are connected in series.

[0035] Specifically, the first rectifier bridge includes input ends Vin3 and Vin4 and output ends Vout3 and Vout4; the second rectifier bridge includes input ends Vin5 and Vin6 and output ends Vout5 and Vout6; the input ends Vin3 and Vin4 are connected with the secondary side of the first transformer Tm1; the input ends Vin5 and Vin6 are connected with the secondary side of the second transformer Tm2; the input end Vin4 is connected with the input end Vin5.

[0036] It should be noted that the first rectifier bridge and the second rectifier bridge have the same structure.

[0037] In this embodiment, the first rectifier bridge is taken as an example, which includes the first diode VD1, the positive electrode of the first diode VD1 is connected with the input Vin3 and the negative electrode of the second diode VD2; the negative electrode of the first diode VD1 is connected with the output Vout3 and the negative electrode of the third diode VD3; the positive electrode of the second diode VD2 is connected with the positive electrode of the fourth diode VD4 and the output Vout4; the negative electrode of the fourth diode VD4 is connected with the input Vin4 and the positive electrode of the third diode VD3.

[0038] The embodiment helps to reduce the withstand voltage level of the diodes in the diode bridge by connecting the output terminals of the first rectifier bridge and the second rectifier bridge in series.

[0039] In another embodiment, the high-power LLC DC power supply device further comprises a second inductor L1, and the input terminals of the plurality of LLC units are connected in parallel and then connected to the positive pole of the power supply through the second inductor L1, thereby helping to prevent interference from the external power supply.

[0040] In yet another embodiment, the device further comprises a control system, such as Figure 4 As shown, the control system comprises a reference voltage value adjustable module, a PI controller, and a frequency modulation module.

[0041] The PI controller is connected to the output terminal of the LLC unit and the reference voltage value adjustable module to obtain the voltage value U0 output by the LLC unit and the reference voltage value Uref set by the reference voltage value adjustable module, and to perform a difference operation on the voltage value U0 and the reference voltage value Uref to obtain a target frequency.

[0042] The PI controller is connected to the plurality of LLC units through the frequency modulation module, so that the frequency modulation module controls the working frequency of the plurality of LLC units to gradually increase or decrease to the target frequency based on the target frequency obtained by the PI controller, thereby achieving the purpose of adjusting the output voltage of the device.

[0043] The embodiment can change the overall gain of the device by adjusting the size of the reference voltage value, thereby achieving the purpose of outputting different voltage values. Moreover, the working frequency of the LLC unit is gradually increased or decreased through the frequency soft start module, thereby helping to improve the stability of the device.

[0044] The same and similar parts among the various embodiments in the specification can be referred to each other. In particular, for the terminal embodiment, since it is basically similar to the method embodiment, the description is simple, and the relevant part can be referred to the description in the method embodiment.

[0045] The units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment.

[0046] The above merely describes preferred embodiments of the present utility model and is not intended to limit the present utility model. For maintenance personnel in the field, the present utility model can be variously changed and varied. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A high-power LLC DC power supply device, characterized by, The device comprises: a plurality of parallelly connected LLC units, each LLC unit comprising: a full-bridge Mosfet circuit, a resonant cavity and a diode rectifier bridge; the resonant cavity is composed of a first capacitor Cr1, a first inductor Lr1, a first transformer Tm1 and a second transformer Tm2 connected in series with each other, wherein the first capacitor Cr1 is a resonant capacitor; the first inductor Lr1 is a resonant inductor; the first transformer Tm1 and the second transformer Tm2 are resonant transformers; the diode rectifier bridge comprises two rectifier bridges, the input ends of the two rectifier bridges are connected with the secondary side output ends of the first transformer Tm1 and the second transformer Tm2 respectively; the output ends of the two rectifier bridges are connected in series.

2. The high power LLC DC power supply device of claim 1, wherein, the full-bridge Mosfet circuit comprises: a first input end Vin1, a second input end Vin2, a first output end Vout1 and a second output end Vout2; the first input end Vin1 is connected with the source of a first MOS transistor V1 and the source of a third MOS transistor V3; the drain of the first MOS transistor V1 is connected with the source of a second MOS transistor V2 and the first output end Vout1; the drain of the third MOS transistor V3 is connected with the second output end Vout2 and the source of a fourth MOS transistor; the drain of the second MOS transistor is connected with the drain of the fourth MOS transistor and the second input end Vin2.

3. The high power LLC DC power supply device of claim 1, wherein, the rectifier bridge comprises: a first diode VD1, the anode of the first diode VD1 is connected with an input Vin3 and the cathode of a second diode VD2; the cathode of the first diode VD1 is connected with an output Vout3 and the anode of a third diode VD3; the anode of the second diode VD2 is connected with the anode of a fourth diode VD4 and an output Vout4; the cathode of the fourth diode VD4 is connected with an input Vin4 and the cathode of the third diode VD3.

4. The high power LLC DC power supply device of claim 1, wherein, The device further comprises a second inductor L1, the input ends of the plurality of LLC units are connected in parallel and then connected to the positive pole of a power supply through the second inductor L1.

5. The high power LLC DC power supply device of claim 1, wherein, The device further comprises a control system, the control system comprises: a soft start module, a reference voltage value adjustable module, a PI controller and a frequency modulation module; the PI controller is connected with the output end of the LLC unit and the reference voltage value adjustable module to obtain the voltage value U0 output by the LLC unit and the reference voltage value Uref set by the reference voltage value adjustable module, and to obtain a target frequency by subtracting the voltage value U0 from the reference voltage value Uref; the PI controller is connected with the plurality of LLC units through the frequency soft start module, so that the frequency soft start module controls the working frequency of the plurality of LLC units to gradually increase or decrease to the target frequency based on the target frequency obtained by the PI controller, thereby achieving the purpose of adjusting the output voltage of the device.

Images