Three-phase LLC resonant converter and power supply equipment

Abstract

This application relates to a three-phase LLC resonant converter and power supply device. The three-phase LLC resonant converter includes: an inverter switch module, the input of which is connected to a DC power supply, and the output of which outputs a three-phase AC voltage; an LLC resonant module, the input of which is connected to the output of the inverter switch module, the LLC resonant module including transformers, the secondary windings of each transformer being connected in a star configuration to convert the three-phase AC voltage into a secondary AC voltage; and a rectifier module, connected to the secondary windings of each transformer, for rectifying the secondary AC voltage and outputting a target electrical signal, the rectifier module including a high-voltage output mode and a high-current output mode. The three-phase LLC resonant converter of this application can meet the requirements of high-power, wide-range operation.

Description

Technical Field

[0001] This application relates to the field of resonant converter technology, and in particular to a three-phase LLC resonant converter and power supply device. Background Technology

[0002] With the rapid development of emerging fields such as new energy, electric vehicles, and energy storage systems, the charging voltage platform is trending towards 950V and is expected to exceed 1000V. Traditional converter structures can no longer meet the demands of this charging voltage platform for high power density, high efficiency, and bidirectional energy flow capabilities. To address this trend, higher output level power supply equipment is needed to achieve high-power charging while also catering to the charging needs of existing low-voltage vehicle models.

[0003] In the power conversion topology of power supply equipment, compared with the traditional series resonant converter, the LLC resonant converter has a wider frequency adjustment range and a flatter gain curve, and performs more stably under light load and wide input range.

[0004] However, existing LLC resonant converters are prone to uneven current due to differences in components, and are limited by many factors such as the withstand voltage of the components, thus restricting the output power range. Utility Model Content

[0005] Therefore, it is necessary to provide a three-phase LLC resonant converter and power supply device capable of high-power, wide-range operation to address the aforementioned technical problems.

[0006] In a first aspect, this application provides a three-phase LLC resonant converter, comprising:

[0007] The inverter switch module has its input terminal connected to a DC power supply and its output terminal outputting a three-phase AC voltage.

[0008] The LLC resonant module has its input terminal connected to the output terminal of the inverter switch module. The LLC resonant module includes a transformer, each transformer including multiple secondary windings. For each secondary winding, its first output terminal is connected to the rectifier module, and its second output terminal is connected together with the second output terminal of the corresponding winding in other transformers, for processing the three-phase AC voltage into a secondary AC voltage.

[0009] The rectifier module is connected to the secondary winding of each transformer and is used to rectify the secondary AC voltage and output the target electrical signal. The rectifier module includes a high voltage output mode and a high current output mode. The rectifier module includes multiple rectifier units, and the number of rectifier units is the same as the number of secondary windings.

[0010] In one embodiment, the three-phase AC voltage includes a first-phase voltage, a second-phase voltage, and a third-phase voltage;

[0011] The inverter switching module includes a first switching unit, a second switching unit, and a third switching unit. The first switching unit, the second switching unit, and the third switching unit are connected in parallel with the DC power supply. The first switching unit is used to output the first phase voltage; the second switching unit is used to output the second phase voltage; and the third switching unit is used to output the third phase voltage.

[0012] In one embodiment, the first switching unit includes switching elements Q1 and Q2; the second switching unit includes switching elements Q3 and Q4; and the third switching unit includes switching elements Q5 and Q6. A first terminal of switching element Q1 is connected to a second terminal of switching element Q2 and outputs a first phase voltage V1 as a first output terminal. A first terminal of switching element Q3 is connected to a second terminal of switching element Q4 and outputs a second phase voltage V2 as a second output terminal. A first terminal of switching element Q5 is connected to a second terminal of switching element Q6 and outputs a third phase voltage V3 as a third output terminal.

[0013] In one embodiment, the first switching unit, the second switching unit, and the third switching unit are all full-bridge inverter units, wherein:

[0014] The first switching unit includes switching elements Q7, Q8, Q9, and Q10. The first end of switching element Q7 and the second end of switching element Q9 are connected and serve as the midpoint of a positive phase. The first end of switching element Q8 and the second end of switching element Q10 are connected and serve as the midpoint of a negative phase. The second ends of output switching elements Q7 and Q8 are both connected to the positive terminal of the DC power supply, and the first ends of switching elements Q9 and Q10 are both connected to the negative terminal of the DC power supply. The voltage between the midpoint of a positive phase and the midpoint of a negative phase is the first phase voltage V1'.

[0015] In one embodiment, the inverter switch module further includes: capacitor C4 and capacitor C5, wherein the first terminal of capacitor C4 is connected to the positive terminal of the DC power supply, the second terminal of capacitor C4 is connected to the first terminal of capacitor C5, and the second terminal of capacitor C5 is connected to the negative terminal of the DC power supply.

[0016] The first switching unit includes: switching element Q19, switching element Q20, switching element Q21, switching element Q22, diode D1, and diode D2; the first terminal of switching element Q19 is connected to the second terminal of switching element Q20 and to the first terminal of diode D1; the first terminal of switching element Q20 is connected to the second terminal of switching element Q21 and outputs the first phase voltage V1” as the first output terminal; the first terminal of switching element Q21 is connected to the second terminal of switching element Q22 and to the second terminal of diode D2; the second terminal of diode D1 is connected to the first terminal of diode D2 and is connected between capacitor C4 and capacitor C5.

[0017] In one embodiment, in high-voltage output mode, the rectifier units are connected in series.

[0018] In one embodiment, in high current output mode, the rectifier units are connected in parallel.

[0019] In one embodiment, a control switch group is provided between two adjacent rectifier units to control the rectifier units to be connected in series or in parallel.

[0020] In one embodiment, it further includes a filtering module, which is connected in parallel with the output of the rectifier module.

[0021] Secondly, this application also provides a power supply device, including a three-phase LLC resonant converter as described in the first aspect.

[0022] The aforementioned three-phase LLC resonant converter and power supply equipment, by connecting the secondary windings of the transformer in a star configuration, achieves balanced voltage across the secondary windings of the transformer, thus improving its ability to withstand unbalanced loads; the sum of the three-phase currents on the secondary side of the transformer is zero, achieving current sharing; and the rectifier module can switch between high-voltage output mode and high-current output mode, enabling the three-phase LLC resonant converter to meet the operating requirements of high power and a wide range. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a block diagram of a three-phase LLC resonant converter in one embodiment;

[0025] Figure 2This is a circuit diagram of an LLC resonant module in one embodiment;

[0026] Figure 3 This is a circuit diagram of a three-phase LLC resonant converter in one embodiment;

[0027] Figure 4 This is a circuit diagram of an inverter switch module in one embodiment;

[0028] Figure 5 This is a circuit diagram of the inverter switch module in another embodiment;

[0029] Figure 6 This is a circuit diagram of the inverter switch module in another embodiment;

[0030] Figure 7 This is a circuit diagram of a three-phase LLC resonant converter in high-current output mode in one embodiment;

[0031] Figure 8 This is a circuit diagram of a three-phase LLC resonant converter in another embodiment. Detailed Implementation

[0032] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0034] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0035] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0036] When used here, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “including / contains” or “having” specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0037] Figure 1 A block diagram of a three-phase LLC resonant converter according to an embodiment of this application is shown. (See also...) Figure 1 The three-phase LLC resonant converter in one embodiment of this application includes: an inverter switch module, the input terminal of which is connected to a DC power supply, and the output terminal of which outputs a three-phase AC voltage; an LLC resonant module, the input terminal of which is connected to the output terminal of the inverter switch module, the LLC resonant module including a transformer, each transformer including multiple secondary windings, for each secondary winding, its first output terminal is connected to a rectifier module, and its second output terminal is connected together with the second output terminals of the corresponding windings in other transformers, for processing the three-phase AC voltage into a secondary AC voltage; and a rectifier module, connected to the secondary windings of each transformer, for rectifying the secondary AC voltage and outputting a target electrical signal, the rectifier module including a high-voltage output mode and a high-current output mode, the rectifier module including multiple rectifier units, the number of rectifier units being the same as the number of secondary windings.

[0038] The inverter switch module converts the DC voltage output from the DC power supply into a controllable three-phase AC voltage by periodically switching on and off the semiconductor switching device. The three-phase AC voltage includes a first phase voltage, a second phase voltage, and a third phase voltage, with a phase difference of 120° between the first phase voltage, the second phase voltage, and the third phase voltage.

[0039] Figure 2 A circuit diagram of an LLC resonant module according to an embodiment of this application is shown; Figure 3 A circuit diagram of a three-phase LLC resonant converter according to one embodiment of this application is shown. See also... Figure 2The LLC resonant module includes a first resonant unit, a second resonant unit, and a third resonant unit, corresponding one-to-one with the first phase voltage, the second phase voltage, and the third phase voltage, respectively. Each resonant unit includes a transformer. Taking the first resonant unit as an example, it includes: a resonant capacitor C1, the first end of which is connected to the first output terminal of the inverter switch module, i.e., used to receive the first phase voltage; and a resonant inductor L1, the first end of which is connected to the second end of the resonant capacitor C1, and the second end of the resonant inductor L1 is connected to the primary winding of the first transformer T1. The second resonant unit includes a resonant capacitor C2, a resonant inductor L2, and a second transformer T2; the third resonant unit includes a resonant capacitor C3, a resonant inductor L3, and a third transformer T3. The second and third resonant units have the same structure as the first resonant unit.

[0040] For example, each transformer includes three secondary windings. For each secondary winding, its first output terminal is connected to the rectifier module, and its second output terminal is connected to the second output terminal of the corresponding winding in other transformers. See also Figure 2 and Figure 3 The secondary side of the first transformer T1 in the first resonant unit includes windings N11, N12, and N13; the secondary side of the second transformer in the second resonant unit includes windings N21, N22, and N23; and the secondary side of the third transformer in the third resonant unit includes windings N31, N32, and N33. The first output terminal of winding N11 is connected to the rectifier module, and its second output terminal is connected to the second output terminals of windings N21 and N31. The first output terminal of winding N12 is connected to the rectifier module, and its second output terminal is connected to the second output terminals of windings N22 and N32. The first output terminal of winding N13 is connected to the rectifier module, and its second output terminal is connected to the second output terminals of windings N23 and N33.

[0041] The three-phase LLC resonant converter provided in this embodiment connects the secondary windings of the transformer in a star configuration, thereby balancing the voltage of each secondary winding and improving the ability to withstand unbalanced loads. The sum of the three-phase currents on the secondary side of the transformer is zero, achieving current sharing. The rectifier module can switch between high-voltage output mode and high-current output mode to meet the high-power, wide-range operation requirements of the three-phase LLC resonant converter.

[0042] In an exemplary embodiment, the inverter switching module in the provided three-phase LLC resonant converter includes: a first switching unit, a second switching unit, and a third switching unit. The first switching unit, the second switching unit, and the third switching unit are respectively connected in parallel with a DC power supply. The first switching unit is used to output a first phase voltage; the second switching unit is used to output a second phase voltage; and the third switching unit is used to output a third phase voltage.

[0043] The first terminals of the first, second, and third switching units are all connected to the positive terminal of the DC power supply; the second terminals of the first, second, and third switching units are all connected to the negative terminal of the DC power supply.

[0044] In one possible implementation, see [reference] Figure 4 The first switching unit includes switching elements Q1 and Q2; the second switching unit includes switching elements Q3 and Q4; the third switching unit includes switching elements Q5 and Q6; the first terminal of switching element Q1 is connected to the second terminal of switching element Q2, and outputs the first phase voltage V1 as the first output terminal; the first terminal of switching element Q3 is connected to the second terminal of switching element Q4, and outputs the second phase voltage V2 as the second output terminal; the first terminal of switching element Q5 is connected to the second terminal of switching element Q6, and outputs the third phase voltage V3 as the third output terminal.

[0045] Optionally, the switching element in the embodiments of this application can be an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), or a GaN HEMT (GaN High Electron Mobility Transistor).

[0046] For example, switching elements Q1-Q6 are all MOSFETs, and the first terminal of each of switching elements Q1-Q6 is the source, and the second terminal is the drain. The drains of switching elements Q1, Q3, and Q5 are all connected to the positive terminal of the DC power supply, and the sources of switching elements Q2, Q4, and Q6 are all connected to the negative terminal of the DC power supply. In other embodiments of this application, when the switching elements are MOSFETs, the first terminal is the source, and the second terminal is the drain.

[0047] In this embodiment, each switching unit has an output terminal connected to the resonant capacitor, resonant inductor and the first terminal of the primary winding of the transformer in the corresponding resonant unit. The second terminals of the primary windings of each transformer in the resonant unit are connected together, resulting in low hardware cost and low insulation pressure on the primary windings of the transformer.

[0048] In one possible implementation, see [reference] Figure 5The first, second, and third switching units are all full-bridge inverter units, each comprising four switching elements. Specifically, the first switching unit includes switching elements Q7, Q8, Q9, and Q10. The first terminal of switching element Q7 is connected to the second terminal of switching element Q9, serving as the midpoint of a positive phase. The first terminal of switching element Q8 is connected to the second terminal of switching element Q10, serving as the midpoint of a negative phase. The second terminals of output switching elements Q7 and Q8 are both connected to the positive terminal of the DC power supply, and the first terminals of switching elements Q9 and Q10 are both connected to the negative terminal of the DC power supply. The voltage between the midpoint of a positive phase and the midpoint of a negative phase is the first phase voltage V1'.

[0049] The positive terminal of one phase is connected to the first terminal of the resonant capacitor C1 in the first resonant unit; the negative terminal of one phase is connected to the second terminal of the primary winding of the first transformer T1. The second switching unit includes switching elements Q11-Q14 for outputting the second phase voltage V2'; the third switching unit includes switching elements Q15-Q18 for outputting the third phase voltage V3'. The structures of the second and third switching units are similar to those of the first switching unit and will not be described in detail here.

[0050] The inverter switching module in this embodiment has greater flexibility, with each switching unit being relatively independent. Even if one module fails, the other switching units can continue to operate. It also facilitates power expansion and parallel connection of multiple modules, making it suitable for high-power, distributed, or modular power systems.

[0051] In one possible implementation, such as Figure 6 As shown, the inverter switch module in this embodiment further includes: capacitor C4 and capacitor C5. The first end of capacitor C4 is connected to the positive terminal of the DC power supply, and the second end of capacitor C4 is connected to the first end of capacitor C5. The second end of capacitor C5 is connected to the negative terminal of the DC power supply. The first switch unit includes: switch element Q19, switch element Q20, switch element Q21, switch element Q22, diode D1, and diode D2. The first end of switch element Q19 is connected to the second end of switch element Q20 and to the first end of diode D1. The first end of switch element Q20 is connected to the second end of switch element Q21 and outputs the first phase voltage V1” as the first output terminal. The first end of switch element Q21 is connected to the second end of switch element Q22 and to the second end of diode D2. The second end of diode D1 is connected to the first end of diode D2 and is connected between capacitor C4 and capacitor C5.

[0052] In this embodiment, the second terminals of switching elements Q19, Q23, and Q27 are connected to the positive terminal of the DC power supply, while the first terminals of switching elements Q22, Q26, and Q30 are connected to the negative terminal of the DC power supply. The voltage at the first terminal of capacitor C4 is the positive terminal voltage of the DC power supply, the voltage at the second terminal of capacitor C5 is the negative terminal voltage of the DC power supply, and the voltage between capacitors C4 and C5 is the midpoint voltage. In this embodiment, diodes D1 and D2 introduce the midpoint voltage into the bridge arm composed of the switching elements in the first switching unit, thereby achieving mid-level control.

[0053] The second switching unit includes: switching elements Q23-Q26, diode D3 and diode D4, with switching element Q24 and switching element Q25 serving as the second output terminal to output the second phase voltage V2”; the third switching unit includes: switching elements Q27-Q30, diode D5 and diode D6, with switching element Q28 and switching element Q29 serving as the third output terminal to output the third phase voltage V3”. The structures of the second and third switching units are the same as those of the first switching unit.

[0054] In this embodiment, each switching unit of the inverter switching module supports complex control algorithms and unbalanced loads, enabling it to provide higher quality output waveforms and higher efficiency.

[0055] In one exemplary embodiment, see further... Figure 3 In high-voltage output mode, the rectifier module includes multiple rectifier units connected in series.

[0056] In the case where the secondary side of the transformer has three windings, the rectifier module may include a first rectifier unit, a second rectifier unit, and a third rectifier unit. The first rectifier unit includes diodes D7, D8, D9, D10, D11, and D12. The first ends of diodes D7-D9 are connected to the first target output terminal, and the second ends of diodes D10-D12 are connected to the second rectifier unit. The first output terminal of the winding N11 of the first transformer is connected between diodes D7 and D10, the first output terminal of the winding N21 of the second transformer is connected between diodes D8 and D11, and the first output terminal of the winding N31 of the third transformer is connected between diodes D9 and D12.

[0057] The second rectifier unit includes diodes D13-D18, and the third rectifier unit includes diodes D19-D24. The structures of the second and third rectifier units are the same as those of the first rectifier unit. The second terminals of diodes D22-D24 in the third rectifier unit are connected to the second target output terminal. The target electrical signal is located between the first target output terminal and the second target output terminal.

[0058] It is understandable that in the LLC resonant module, the secondary AC voltage output by the first transformer is output to the first rectifier unit from the first output terminal of winding N11, the second rectifier unit from the first output terminal of winding N12, and the third rectifier unit from the first output terminal of winding N13; the secondary AC voltage output by the second transformer is output to the first rectifier unit from the first output terminal of winding N21, the second rectifier unit from the first output terminal of winding N22, and the third rectifier unit from the first output terminal of winding N23; and the secondary AC voltage output by the third transformer is output to the first rectifier unit from the first output terminal of winding N31, the second rectifier unit from the first output terminal of winding N32, and the third rectifier unit from the first output terminal of winding N33.

[0059] In conjunction with the foregoing embodiments, Figure 3 In the three-phase LLC resonant converter shown, the inverter switching module adopts... Figure 4 The structure shown can also be adopted Figure 3 or Figure 5 The structure in.

[0060] In one possible implementation, see [reference] Figure 7 In high current output mode, the rectifier module includes multiple rectifier units, which are connected in parallel.

[0061] In conjunction with the foregoing embodiments, Figure 7 In the three-phase LLC resonant converter shown, the inverter switching module adopts... Figure 3 The structure shown can also be adopted Figure 4 or Figure 5 The structure in.

[0062] Optionally, each rectifier unit in the embodiments of this application can be Figure 6 The three-phase full-wave rectifier circuit shown can also be a rectifier circuit formed by two three-phase full-wave rectifier circuits connected in parallel or in series, or it can be a semi-controlled rectifier circuit composed of three thyristors and three diodes. This application does not limit this.

[0063] In one possible implementation, see [reference] Figure 8 The rectifier module includes multiple rectifier units, and a control switch group is set between two adjacent rectifier units to control the rectifier units to be connected in series or in parallel.

[0064] The control switch group between the first and second rectifier units may include control switches K1, K2, and K3; the control switch group between the second and third rectifier units may include control switches K4, K5, and K6. When control switches K1 and K4 are closed, and the others are open, the first, second, and third rectifier units are connected in series, and the rectifier module enters a high-voltage output mode, with each rectifier unit capable of outputting up to 500V. At this time, the three-phase LLC resonant converter can output a higher voltage, with the target electrical signal output reaching 1500V. When control switches K2, K3, K5, and K6 are closed, and control switches K1 and K4 are open, the first, second, and third rectifier units are connected in parallel, and the rectifier module enters a high-current output mode. At this time, the three-phase LLC resonant converter can output a higher current.

[0065] Optionally, the secondary side of the transformer may have four windings or other numbers of windings connected in a star configuration; this application does not limit this. The number of rectifier units in the rectifier module is the same as the number of windings on the secondary side of the transformer.

[0066] In this embodiment, connecting the rectifier units in series can achieve high voltage output, while connecting them in parallel can achieve high current output. Thus, by switching between series and parallel connections of the rectifier units, the output voltage or current range can be widened, achieving greater output power and meeting higher-demand application scenarios.

[0067] In an exemplary embodiment, the provided three-phase LLC resonant converter further includes a filter module, which is connected in parallel with the output of the rectifier module.

[0068] The filtering module may include a filter capacitor C6, and the target electrical signal is located between the first and second terminals of the filter capacitor C6. In this embodiment, the filtering module is used to filter out the high-frequency ripple after rectification, making the output target electrical signal more stable.

[0069] In one exemplary embodiment, a three-phase LLC resonant converter is provided, comprising:

[0070] The inverter switch module has its input terminal connected to a DC power supply and its output terminal outputting a three-phase AC voltage, including a first-phase voltage, a second-phase voltage, and a third-phase voltage. The inverter switch module includes a first switch unit, a second switch unit, and a third switch unit, which are connected in parallel with the DC power supply. The first switch unit is used to output the first-phase voltage; the second switch unit is used to output the second-phase voltage; and the third switch unit is used to output the third-phase voltage.

[0071] The LLC resonant module has its input terminal connected to the output terminal of the inverter switch module. The LLC resonant module includes a transformer, each transformer including multiple secondary windings. For each secondary winding, its first output terminal is connected to the rectifier module, and its second output terminal is connected together with the second output terminal of the corresponding winding in other transformers, for processing the three-phase AC voltage into a secondary AC voltage.

[0072] The rectifier module, connected to the secondary windings of each transformer, is used to rectify the secondary AC voltage and output the target electrical signal. The rectifier module includes high-voltage output mode and high-current output mode, and comprises multiple rectifier units, the number of which matches the number of secondary windings. In high-voltage output mode, the rectifier units are connected in series; in high-current output mode, they are connected in parallel. A control switch group is provided between adjacent rectifier units to control whether the rectifier units are connected in series or in parallel.

[0073] The filter module is connected in parallel with the output of the rectifier module.

[0074] In one embodiment, the first switching unit includes switching elements Q1 and Q2; the second switching unit includes switching elements Q3 and Q4; and the third switching unit includes switching elements Q5 and Q6. A first terminal of switching element Q1 is connected to a second terminal of switching element Q2 and outputs a first phase voltage V1 as a first output terminal. A first terminal of switching element Q3 is connected to a second terminal of switching element Q4 and outputs a second phase voltage V2 as a second output terminal. A first terminal of switching element Q5 is connected to a second terminal of switching element Q6 and outputs a third phase voltage V3 as a third output terminal.

[0075] In one embodiment, the first switching unit, the second switching unit, and the third switching unit are all full-bridge inverter units, wherein: the first switching unit includes switching elements Q7, Q8, Q9, and Q10; the first end of switching element Q7 and the second end of switching element Q9 are connected and serve as the midpoint of a positive phase; the first end of switching element Q8 and the second end of switching element Q10 are connected and serve as the midpoint of a negative phase; the second ends of output switching elements Q7 and Q8 are both connected to the positive terminal of the DC power supply, and the first ends of switching elements Q9 and Q10 are both connected to the negative terminal of the DC power supply; the voltage between the midpoint of a positive phase and the midpoint of a negative phase is the first phase voltage V1'.

[0076] In one embodiment, the inverter switching module further includes: capacitor C4 and capacitor C5, the first end of capacitor C4 is connected to the positive terminal of the DC power supply, and the second end of capacitor C4 is connected to the first end of capacitor C5; the second end of capacitor C5 is connected to the negative terminal of the DC power supply; the first switching unit includes: switching element Q19, switching element Q20, switching element Q21, switching element Q22, diode D1, and diode D2; the first end of switching element Q19 is connected to the second end of switching element Q20 and to the first end of diode D1; the first end of switching element Q20 is connected to the second end of switching element Q21 and outputs the first phase voltage V1” as the first output terminal; the first end of switching element Q21 is connected to the second end of switching element Q22 and to the second end of diode D2; the second end of diode D1 is connected to the first end of diode D2 and is connected between capacitor C4 and capacitor C5.

[0077] In one exemplary embodiment, a power supply device is provided, including the three-phase LLC resonant converter described in the above embodiments.

[0078] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A three-phase LLC resonant converter, characterized in that, include: An inverter switch module, wherein the input terminal of the inverter switch module is connected to a DC power supply, and the output terminal of the inverter switch module outputs a three-phase AC voltage; The LLC resonant module has its input terminal connected to the output terminal of the inverter switch module. The LLC resonant module includes a transformer, each transformer including multiple secondary windings. For each secondary winding, its first output terminal is connected to the rectifier module, and its second output terminal is connected together with the second output terminal of the corresponding winding in other transformers, for processing the three-phase AC voltage into a secondary AC voltage. The rectifier module is connected to the secondary winding of each transformer and is used to rectify the secondary AC voltage to output a target electrical signal. The rectifier module includes a high-voltage output mode and a high-current output mode. The rectifier module includes multiple rectifier units, the number of which is the same as the number of secondary windings. In the high-voltage output mode, the rectifier units are connected in series; in the high-current output mode, the rectifier units are connected in parallel. A control switch group is provided between two adjacent rectifier units to control the series or parallel connection of the rectifier units.

2. The three-phase LLC resonant converter according to claim 1, characterized in that, The three-phase AC voltage includes the first phase voltage, the second phase voltage, and the third phase voltage; The inverter switching module includes a first switching unit, a second switching unit, and a third switching unit. The first switching unit, the second switching unit, and the third switching unit are connected in parallel with the DC power supply. The first switching unit is used to output the first phase voltage; the second switching unit is used to output the second phase voltage; and the third switching unit is used to output the third phase voltage.

3. The three-phase LLC resonant converter according to claim 2, characterized in that, The first switching unit includes switching elements Q1 and Q2; the second switching unit includes switching elements Q3 and Q4; the third switching unit includes switching elements Q5 and Q6; the first end of switching element Q1 is connected to the second end of switching element Q2 and outputs a first phase voltage V1 as a first output terminal; the first end of switching element Q3 is connected to the second end of switching element Q4 and outputs a second phase voltage V2 as a second output terminal; the first end of switching element Q5 is connected to the second end of switching element Q6 and outputs a third phase voltage V3 as a third output terminal.

4. The three-phase LLC resonant converter according to claim 2, characterized in that, The first switching unit, the second switching unit, and the third switching unit are all full-bridge inverter units, wherein: The first switching unit includes switching elements Q7, Q8, Q9, and Q10. The first end of switching element Q7 and the second end of switching element Q9 are connected and serve as the midpoint of a positive phase. The first end of switching element Q8 and the second end of switching element Q10 are connected and serve as the midpoint of a negative phase. The second ends of output switching elements Q7 and Q8 are both connected to the positive terminal of the DC power supply, and the first ends of switching elements Q9 and Q10 are both connected to the negative terminal of the DC power supply. The voltage between the midpoint of the positive phase and the midpoint of the negative phase is the first phase voltage V1'.

5. The three-phase LLC resonant converter according to claim 2, characterized in that, The inverter switch module further includes: capacitor C4 and capacitor C5, wherein the first end of capacitor C4 is connected to the positive terminal of the DC power supply, the second end of capacitor C4 is connected to the first end of capacitor C5, and the second end of capacitor C5 is connected to the negative terminal of the DC power supply. The first switching unit includes: switching element Q19, switching element Q20, switching element Q21, switching element Q22, diode D1, and diode D2; the first end of switching element Q19 is connected to the second end of switching element Q20 and to the first end of diode D1; the first end of switching element Q20 is connected to the second end of switching element Q21 and outputs the first phase voltage V1” as the first output terminal; the first end of switching element Q21 is connected to the second end of switching element Q22 and to the second end of diode D2; the second end of diode D1 is connected to the first end of diode D2 and is connected between capacitor C4 and capacitor C5.

6. The three-phase LLC resonant converter according to claim 2, characterized in that, The LLC resonant module includes a first resonant unit, a second resonant unit, and a third resonant unit, which correspond one-to-one with the first phase voltage, the second phase voltage, and the third phase voltage, respectively. Each resonant unit includes a transformer; the secondary winding of the transformer is connected in a star configuration.

7. The three-phase LLC resonant converter according to claim 1, characterized in that, The rectifier module may include a first rectifier unit, a second rectifier unit, and a third rectifier unit.

8. The three-phase LLC resonant converter according to claim 7, characterized in that, The control switch group between the first rectifier unit and the second rectifier unit includes control switch K1, control switch K2 and control switch K3; the control switch group between the second rectifier unit and the third rectifier unit includes control switch K4, control switch K5 and control switch K6; Close the control switch K1 and the control switch K4, and disconnect the others. The first rectifier unit, the second rectifier unit, and the third rectifier unit are connected in series. Close the control switches K2, K3, K5, and K6, and open the control switches K1 and K4. The first rectifier unit, the second rectifier unit, and the third rectifier unit are connected in parallel.

9. The three-phase LLC resonant converter according to claim 1, characterized in that, Also includes: A filtering module is connected in parallel with the output terminal of the rectifier module.

10. A power supply device, characterized in that, The three-phase LLC resonant converter includes any one of claims 1-9.

Images