Three-phase single-stage isolation type three-interlaced AC / DC converter

Abstract

The utility model relates to the technical field of automobile chargers, in particular to a three-phase single-stage isolation type three-interlaced AC / DC converter, which comprises a power supply unit and a rectification unit, the power supply unit comprises a first power supply module and a second power supply module, the rectification unit comprises an adjusting module and a rectification module, the first power supply module is connected with the adjusting module and the rectification module, and the second power supply module is connected with the rectification module. The adjusting module and the rectification module are connected with the second power supply module. According to the utility model, the input current is accurately adjusted and isolated conversion is realized by adopting the three bridge arms of which the wave-emitting phase difference is 120 degrees, and the isolated conversion of the three-phase PFC and the DCDC can be simultaneously realized through the three-phase rectification and three-phase T-type staggered LLC conversion topology, so that the conversion efficiency during the charging of the automobile is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile chargers, in particular to a three-phase single-stage isolation type three-interleaved AC / DC converter. Background Art

[0002] A car charger is a device specially designed for charging the battery of an electric vehicle. It is an electric power conversion device with specific functions used when charging the battery. It includes components such as an input interface, a control unit, a low-voltage auxiliary unit, a power unit, and an output port.

[0003] The power unit is used to convert alternating current into direct current, such as an AC / DC converter involved in CN101728961B, including a front-stage PFC circuit and a rear-stage DC / DC converter, characterized in that the PFC circuit is a PFC circuit with midpoint clamping, and the DC / DC converter is an LLC converter with synchronous rectification. The AC / DC converter can realize the input PFC function, so that the input current follows the input voltage and outputs the required voltage. However, the charging efficiency of car chargers is increasingly required. In order to keep up with the development of electric vehicles and effectively promote the popularization of electric vehicles, these AC / DC conversion systems need to use a three-phase PFC topology at the front end to efficiently and effectively provide more than 10kW of power. Therefore, taking the above-mentioned AC / DC converter as an example, it needs to add an additional three-phase PFC topology when used for car charging. The structure is relatively bloated and the conversion efficiency of this two-stage circuit structure is not ideal.

[0004] In order to integrate the three-phase PFC topology and AC / DC converter, realize the three-phase PFC and isolation conversion functions at the same time and improve the conversion efficiency, a three-phase single-stage isolated three-interleaved AC / DC converter is proposed. Utility Model Content

[0005] The purpose of the utility model is to provide a three-phase single-stage isolated three-interleaved AC / DC converter to solve the problems raised in the above background technology.

[0006] To achieve the above object, the utility model provides a three-phase single-stage isolated three-interleaved AC / DC converter, including a power supply unit and a rectifier unit, the power supply unit includes a first power supply module and a second power supply module, the rectifier unit includes a regulating module and a rectifier module, the first power supply module is connected to the regulating module and the rectifier module, the regulating module and the rectifier module are both connected to the second power supply module;

[0007] The converter is connected to an external power supply through the first power module, and accurately adjusts the input current through the adjustment module and the rectification module to achieve isolated conversion and output through the second power module.

[0008] As a further improvement of the present technical solution, the first power module includes inductors LA, LB, and LC, the inductor LA is connected to the capacitor C7 and connected to point A, the inductor LB is connected to the capacitor C6 and connected to point B, and the inductor LC is connected to the capacitor C5 and connected to point C.

[0009] As a further improvement of the technical solution, the regulating module is three bridge arms with a wave transmission phase difference of 120°.

[0010] As a further improvement of the technical solution, the rectifier module includes a first rectifier circuit and a second rectifier circuit, and the first rectifier circuit includes diodes D1, D2, D3, D4, D5, D6 and MOS tubes S1, S2, S3, S4, S5, S6, wherein,

[0011] The cathode end of the diode D1 is connected to the cathode end of the diode D3, the cathode end of the diode D5 is connected in parallel to the MOS tubes S1, S2, and S3, the anode end of the diode D1 is connected to the cathode end of the diode D2 and connected to point A, the anode end of the diode D2 is connected to the anode end of the diode D4, the anode end of the diode D6 is connected in parallel to the MOS tubes S4, S5, and S6;

[0012] The positive terminal of the diode D3 is connected to the negative terminal of the diode D4 and connected to point B;

[0013] The positive terminal of the diode D5 is connected to the negative terminal of the diode D6 and connected to point C;

[0014] The other end of the MOS tube S1 is connected to the other end of the MOS tube S4 and connected to points D, E, F, and G;

[0015] The other end of the MOS transistor S2 is connected to the other end of the MOS transistor S5 and connected to points H, I, J, and M;

[0016] The other end of the MOS transistor S3 is connected to the other end of the MOS transistor S6 and is connected to points K, L, N, and O.

[0017] As a further improvement of the technical solution, the second rectifier circuit includes diodes D7, D8, D9, D10, D11, D12, capacitor C4 and load resistor R1, wherein:

[0018] The cathode terminal of the diode D7 is connected to the cathode terminal of the diode D8, the cathode terminal of the diode D9 is connected in parallel to the capacitor C4 and the load resistor R1, and the anode terminal of the diode D7 is connected to the cathode terminal of the diode D10 and in parallel to point R;

[0019] The positive terminal of the diode D10 is connected to the positive terminal of the diode D11, and the positive terminal of the diode D12 is connected in parallel to the other end of the capacitor C4 and the other end of the load resistor R1;

[0020] The positive terminal of the diode D8 is connected to the negative terminal of the diode D11 and connected to the Q point;

[0021] The anode terminal of the diode D9 is connected to the cathode terminal of the diode D12 and connected to point P.

[0022] As a further improvement of the technical solution, the second power supply module includes transformers T1, T2, and T3, wherein:

[0023] One end of the main winding of the transformer T1 is connected to the inductor L1, the inductor L1 is connected to the capacitor C1, the capacitor C1 is connected to point G, and one end of the secondary winding of the transformer T1 is connected to point P;

[0024] One end of the main winding of the transformer T2 is connected to the inductor L2, the inductor L2 is connected to the capacitor C2, the capacitor C2 is connected to the M point, and one end of the secondary winding of the transformer T2 is connected to the Q point;

[0025] One end of the main winding of the transformer T3 is connected to the inductor L3, the inductor L3 is connected to the capacitor C3, the capacitor C3 is connected to the point O, and one end of the secondary winding of the transformer T2 is connected to the point R;

[0026] The other end of the main winding of the transformer T2 and the other end of the main winding of T3 are both connected to the other end of the main winding of the transformer T1, and the other end of the secondary winding of the transformer T2 and the other end of the secondary winding of T3 are both connected to the other end of the secondary winding of the transformer T1.

[0027] Compared with the prior art, the utility model has the following beneficial effects:

[0028] In this three-phase single-stage isolated three-interleaved AC / DC converter, three bridge arms with a 120° phase difference are used to accurately adjust the input current to achieve isolated conversion. Through the three-phase rectification plus three-phase T-type interleaved LLC conversion topology, the isolated conversion of three-phase PFC and DCDC can be achieved simultaneously, thereby improving the conversion efficiency when the car is charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the circuit diagram of the existing SWISS rectifier;

[0030] Figure 2 Waveform diagram Figure 1 ;

[0031] Figure 3 Waveform diagram Figure 2 ;

[0032] Figure 4Waveform diagram Figure 3 ;

[0033] Figure 5 It is a schematic diagram of the overall structure of the utility model;

[0034] Figure 6 It is the overall circuit diagram of the utility model. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] like Figure 1 As shown, the SWISS rectifier compares the values ​​of Ua, Ub, and Uc, selects the middle phase switch to turn on, and selects the middle value of Ua, Ub, and Uc at low frequency to select the middle MOS tube to turn on and off. Figure 2-4 The waveform shown, where Upy, Upn, and Uyn are Figure 1 The potential difference between the three points P, Y and N in the equation;

[0037] The SWISS rectifier is a new type of step-down rectifier with power factor correction function. It is often used as a core component of fast-charging equipment such as electric vehicles. However, when used for car charging, it requires an additional three-phase PFC topology structure. The structure is relatively bloated and the conversion efficiency of this two-stage circuit structure is not ideal.

[0038] Therefore, please refer to Figure 5-Figure 6 As shown, this embodiment provides a three-phase single-stage isolated three-interleaved AC / DC converter, including a power supply unit and a rectifier unit, the power supply unit includes a first power supply module and a second power supply module, the rectifier unit includes a regulating module and a rectifier module, the first power supply module is connected to the regulating module and the rectifier module, and the regulating module and the rectifier module are both connected to the second power supply module;

[0039] The converter is connected to an external power supply through the first power module, and accurately adjusts the input current through the adjustment module and the rectification module to achieve isolated conversion and output through the second power module.

[0040] The first power module includes inductors LA, LB, and LC. The inductor LA is connected to the capacitor C7 and connected to point A. The inductor LB is connected to the capacitor C6 and connected to point B. The inductor LC is connected to the capacitor C5 and connected to point C.

[0041] The regulating module is composed of three bridge arms with a 120° phase difference. The first bridge arm includes high-frequency action MOS tubes S7, S8, S9, S10, S11, and S12.

[0042] High-frequency action MOS tubes S7, S9, and S11 are all connected to point A;

[0043] The other end of the high-frequency action MOS tube S7 is connected to the high-frequency action MOS tube S8, and the high-frequency action MOS tube S8 is connected to the D point;

[0044] The other end of the high-frequency action MOS tube S9 is connected to the high-frequency action MOS tube S10, and the high-frequency action MOS tube S10 is connected to the H point;

[0045] The other end of the high-frequency action MOS tube S11 is connected to the high-frequency action MOS tube S12, and the high-frequency action MOS tube S12 is connected to the K point;

[0046] The second bridge arm includes high-frequency action MOS tubes S13, S14, S15, S16, S17, and S18.

[0047] High-frequency action MOS tubes S13, S15, and S17 are all connected to point B;

[0048] The other end of the high-frequency action MOS tube S13 is connected to the high-frequency action MOS tube S14, and the high-frequency action MOS tube S14 is connected to the F point;

[0049] The other end of the high-frequency action MOS tube S15 is connected to the high-frequency action MOS tube S16, and the high-frequency action MOS tube S16 is connected to the J point;

[0050] The other end of the high-frequency action MOS tube S17 is connected to the high-frequency action MOS tube S18, and the high-frequency action MOS tube S18 is connected to the L point;

[0051] The third bridge arm includes high-frequency action MOS tubes S19, S20, S21, S22, S23, and S24;

[0052] The other end of the high-frequency action MOS tube S19 is connected to the high-frequency action MOS tube S20, and the high-frequency action MOS tube S20 is connected to the F point;

[0053] The other end of the high-frequency action MOS tube S21 is connected to the high-frequency action MOS tube S22, and the high-frequency action MOS tube S22 is connected to the J point;

[0054] The other end of the high-frequency action MOS transistor S23 is connected to the high-frequency action MOS transistor S24, and the high-frequency action MOS transistor S24 is connected to the L point.

[0055] The rectifier module includes a first rectifier circuit and a second rectifier circuit, and the first rectifier circuit includes diodes D1, D2, D3, D4, D5, D6 and MOS tubes S1, S2, S3, S4, S5, S6, wherein:

[0056] The cathode end of the diode D1 is connected to the cathode end of the diode D3, the cathode end of the diode D5 is connected in parallel to the MOS tubes S1, S2, and S3, the anode end of the diode D1 is connected to the cathode end of the diode D2 and connected to point A, the anode end of the diode D2 is connected to the anode end of the diode D4, the anode end of the diode D6 is connected in parallel to the MOS tubes S4, S5, and S6;

[0057] The positive terminal of the diode D3 is connected to the negative terminal of the diode D4 and connected to point B;

[0058] The positive terminal of the diode D5 is connected to the negative terminal of the diode D6 and connected to point C;

[0059] The other end of the MOS tube S1 is connected to the other end of the MOS tube S4 and connected to points D, E, F, and G;

[0060] The other end of the MOS transistor S2 is connected to the other end of the MOS transistor S5 and connected to points H, I, J, and M;

[0061] The other end of the MOS transistor S3 is connected to the other end of the MOS transistor S6 and connected to points K, L, N, and O;

[0062] The second rectifier circuit includes diodes D7, D8, D9, D10, D11, D12, capacitor C4 and load resistor R1, wherein:

[0063] The cathode terminal of the diode D7 is connected to the cathode terminal of the diode D8, the cathode terminal of the diode D9 is connected in parallel to the capacitor C4 and the load resistor R1, and the anode terminal of the diode D7 is connected to the cathode terminal of the diode D10 and in parallel to point R;

[0064] The positive terminal of the diode D10 is connected to the positive terminal of the diode D11, and the positive terminal of the diode D12 is connected in parallel to the other end of the capacitor C4 and the other end of the load resistor R1;

[0065] The positive terminal of the diode D8 is connected to the negative terminal of the diode D11 and connected to the Q point;

[0066] The positive terminal of the diode D9 is connected to the negative terminal of the diode D12 and connected to point P;

[0067] The second power supply module includes transformers T1, T2, and T3, wherein:

[0068] One end of the main winding of the transformer T1 is connected to the inductor L1, the inductor L1 is connected to the capacitor C1, the capacitor C1 is connected to point G, and one end of the secondary winding of the transformer T1 is connected to point P;

[0069] One end of the main winding of the transformer T2 is connected to the inductor L2, the inductor L2 is connected to the capacitor C2, the capacitor C2 is connected to the M point, and one end of the secondary winding of the transformer T2 is connected to the Q point;

[0070] One end of the main winding of the transformer T3 is connected to the inductor L3, the inductor L3 is connected to the capacitor C3, the capacitor C3 is connected to the point O, and one end of the secondary winding of the transformer T2 is connected to the point R;

[0071] The other end of the main winding of the transformer T2 and the other end of the main winding of T3 are both connected to the other end of the main winding of the transformer T1, and the other end of the secondary winding of the transformer T2 and the other end of the secondary winding of T3 are both connected to the other end of the secondary winding of the transformer T1.

[0072] In the utility model, a high-frequency switch tube is used to replace the low-frequency selection switch in the SWISS rectifier;

[0073] When Ua>Ub>Uc and Upy>Uyn, the working process is briefly described as follows: the phase difference between the starting wave of the upper tube corresponding to the three bridge arms is 120°, and the phase difference between the starting wave of the lower tube corresponding to the three bridge arms is 120°. The middle MOS tube S13-S18 high-frequency switching action corresponding to the phase of Ub is selected. Since Upy>Uyn, the current flows into point Y, so the size of the current flowing into point Y is adjusted by adjusting the size of the duty cycle of MOS tubes S14, S16, and S18.

[0074] When Ua>Ub>Uc and Uyn>Upy, the working process is briefly described as follows: the phase difference between the starting wave of the upper tube corresponding to the three bridge arms is 120°, and the phase difference between the starting wave of the lower tube corresponding to the three bridge arms is 120°. The middle MOS tube S13-S18 high-frequency switching action corresponding to the phase of Ub is selected. Since Uyn>Upy, the current flows out of point Y, so the size of the current flowing out of point Y is adjusted by adjusting the size of the duty cycle of MOS tubes S13, S15, and S17.

[0075] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A three-phase single-stage isolated three-interleaved AC / DC converter, characterized in that: It includes a power supply unit and a rectifier unit, the power supply unit includes a first power supply module and a second power supply module, the rectifier unit includes a regulating module and a rectifier module, the first power supply module is connected to the regulating module and the rectifier module, and the regulating module and the rectifier module are both connected to the second power supply module; The converter is connected to an external power supply through the first power module, and accurately adjusts the input current through the adjustment module and the rectification module to achieve isolated conversion and output through the second power module.

2. The three-phase single-stage isolated three-interleaved AC / DC converter according to claim 1, characterized in that: The first power module includes inductors LA, LB, and LC. The inductor LA is connected to the capacitor C7 and connected to point A. The inductor LB is connected to the capacitor C6 and connected to point B. The inductor LC is connected to the capacitor C5 and connected to point C.

3. The three-phase single-stage isolated three-interleaved AC / DC converter according to claim 1, characterized in that: The regulating module is composed of three bridge arms with a wave transmission phase difference of 120°.

4. The three-phase single-stage isolated three-interleaved AC / DC converter according to claim 1, characterized in that: The rectifier module includes a first rectifier circuit and a second rectifier circuit, and the first rectifier circuit includes diodes D1, D2, D3, D4, D5, D6 and MOS tubes S1, S2, S3, S4, S5, S6, wherein: The cathode end of the diode D1 is connected to the cathode end of the diode D3, the cathode end of the diode D5 is connected in parallel to the MOS tubes S1, S2, and S3, the anode end of the diode D1 is connected to the cathode end of the diode D2 and connected to point A, the anode end of the diode D2 is connected to the anode end of the diode D4, the anode end of the diode D6 is connected in parallel to the MOS tubes S4, S5, and S6; The positive terminal of the diode D3 is connected to the negative terminal of the diode D4 and connected to point B; The positive terminal of the diode D5 is connected to the negative terminal of the diode D6 and connected to point C; The other end of the MOS tube S1 is connected to the other end of the MOS tube S4 and connected to points D, E, F, and G; The other end of the MOS transistor S2 is connected to the other end of the MOS transistor S5 and connected to points H, I, J, and M; The other end of the MOS transistor S3 is connected to the other end of the MOS transistor S6 and is connected to points K, L, N, and O.

5. The three-phase single-stage isolated three-interleaved AC / DC converter according to claim 4, characterized in that: The second rectifier circuit includes diodes D7, D8, D9, D10, D11, D12, a capacitor C4 and a load resistor R1, wherein: The cathode terminal of the diode D7 is connected to the cathode terminal of the diode D8, the cathode terminal of the diode D9 is connected in parallel to the capacitor C4 and the load resistor R1, and the anode terminal of the diode D7 is connected to the cathode terminal of the diode D10 and in parallel to point R; The positive terminal of the diode D10 is connected to the positive terminal of the diode D11, and the positive terminal of the diode D12 is connected in parallel to the other end of the capacitor C4 and the other end of the load resistor R1; The positive terminal of the diode D8 is connected to the negative terminal of the diode D11 and connected to the Q point; The anode terminal of the diode D9 is connected to the cathode terminal of the diode D12 and connected to point P.

6. The three-phase single-stage isolated three-interleaved AC / DC converter according to claim 1, characterized in that: The second power supply module includes transformers T1, T2, and T3, wherein: One end of the main winding of the transformer T1 is connected to the inductor L1, the inductor L1 is connected to the capacitor C1, the capacitor C1 is connected to point G, and one end of the secondary winding of the transformer T1 is connected to point P; One end of the main winding of the transformer T2 is connected to the inductor L2, the inductor L2 is connected to the capacitor C2, the capacitor C2 is connected to the M point, and one end of the secondary winding of the transformer T2 is connected to the Q point; One end of the main winding of the transformer T3 is connected to the inductor L3, the inductor L3 is connected to the capacitor C3, the capacitor C3 is connected to the point O, and one end of the secondary winding of the transformer T2 is connected to the point R; The other end of the main winding of the transformer T2 and the other end of the main winding of T3 are both connected to the other end of the main winding of the transformer T1, and the other end of the secondary winding of the transformer T2 and the other end of the secondary winding of T3 are both connected to the other end of the secondary winding of the transformer T1.

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