An acdc circuit and power supply device

Abstract

The utility model relates to an ACDC circuit and power supply equipment, this ACDC circuit includes three -phase input voltage source, three -phase input filter inductance, first primary side conversion circuit, main transformer, output rectifier circuit and output filter circuit, adopts single -stage type's ACDC topology, reduces the device quantity of circuit use, is favorable to the cost saving, through setting up first switching circuit to switch the series -parallel connection of first rectifier circuit and second rectifier circuit, realizes wide voltage output.

Description

Technical Field

[0001] This utility model relates to the field of power supply charging, specifically to an ACDC circuit and power supply device. Background Technology

[0002] Currently, charging modules and AC / DC isolated power supplies generally employ a two-stage topology. The front-end uses a three-phase Vienna topology to achieve AC-to-DC rectification and input power factor correction. The rear-end topology uses an isolated DC-DC topology to achieve electrical safety isolation and voltage conversion from bus voltage to the required voltage. This rear-end topology typically uses an LLC resonant circuit or a phase-shifted full-bridge circuit. Using a two-stage AC-DC isolated topology requires adding a large bus capacitor between the two stages to decouple the control loops and allow for dynamic load following. This two-stage topology necessitates designing more components and a larger size, resulting in lower power density and lower conversion efficiency. Utility Model Content

[0003] This utility model provides an AC-CDC circuit and power supply device. The AC-CDC circuit adopts a single-stage AC-CDC topology, which reduces the number of components used in the circuit, helps to save costs, and achieves wide voltage output.

[0004] In a first aspect, this utility model embodiment provides an ACDC circuit, the ACDC circuit comprising: Three-phase input voltage source; A three-phase input filter inductor is connected to the three-phase input voltage source; The first primary-side conversion circuit includes a first bidirectional switching circuit, a second bidirectional switching circuit, a third bidirectional switching circuit, a fourth bidirectional switching circuit, a fifth bidirectional switching circuit, a sixth bidirectional switching circuit, a first inductor, and a first capacitor. The two ends of the first bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the second bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the third bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the fourth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The two ends of the fifth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The two ends of the sixth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The main transformer has a first end of its first primary winding connected to the other end of the first inductor, and a second end of its first primary winding connected to the other end of the first capacitor. An output rectifier circuit is connected to the secondary winding and the first switching circuit, respectively. An output filtering circuit is provided, which is connected to the first switching circuit and the first resistor.

[0005] Optionally, the three-phase input voltage source includes a first voltage source, a second voltage source, and a third voltage source, and the three-phase input filter inductor includes a first input filter inductor, a second input filter inductor, and a third input filter inductor; The two ends of the first input filter inductor are respectively connected to the first voltage source and the first bidirectional switching circuit, the two ends of the second input filter inductor are respectively connected to the second voltage source and the second bidirectional switching circuit, and the two ends of the third input filter inductor are respectively connected to the third voltage source and the third bidirectional switching circuit.

[0006] Optionally, the first bidirectional switching circuit includes a first switching transistor and a second switching transistor, the second bidirectional switching circuit includes a third switching transistor and a fourth switching transistor, the third bidirectional switching circuit includes a fifth switching transistor and a sixth switching transistor, the fourth bidirectional switching circuit includes a seventh switching transistor and an eighth switching transistor, the fifth bidirectional switching circuit includes a ninth switching transistor and a tenth switching transistor, and the sixth bidirectional switching circuit includes an eleventh switching transistor and a twelfth switching transistor. The two ends of the first switching transistor are respectively connected to the other end of the first input filter inductor and one end of the second switching transistor, and the other end of the second switching transistor is connected to one end of the first inductor; the two ends of the third switching transistor are respectively connected to the other end of the second input filter inductor and one end of the fourth switching transistor, and the other end of the fourth switching transistor is connected to one end of the first inductor; the two ends of the fifth switching transistor are respectively connected to the other end of the third input filter inductor and one end of the sixth switching transistor, and the other end of the sixth switching transistor is connected to one end of the first inductor. The two ends of the seventh switch are respectively connected to the other end of the first input filter inductor and one end of the eighth switch, and the other end of the eighth switch is connected to one end of the first capacitor; the two ends of the ninth switch are respectively connected to the other end of the second input filter inductor and one end of the tenth switch, and the other end of the tenth switch is connected to one end of the first capacitor; the two ends of the eleventh switch are respectively connected to the other end of the third input filter inductor and one end of the twelfth switch, and the other end of the twelfth switch is connected to one end of the first capacitor.

[0007] Optionally, the ACDC circuit includes a second switching circuit, which includes a first switch and a second switch; The first switch is connected to the other end of the first inductor and the first end of the first primary winding of the main transformer, and the second switch is connected to the other end of the first inductor and the third end of the first primary winding.

[0008] Optionally, the output rectifier circuit includes a first rectifier circuit and a second rectifier circuit. The first rectifier circuit includes a first diode, a second diode, a third diode, and a fourth diode. The second rectifier circuit includes a fifth diode, a sixth diode, a seventh diode, and an eighth diode. The main transformer includes a first secondary winding and a second secondary winding. The first end of the first secondary winding is connected to the anode of the first diode and the cathode of the second diode, respectively; the second end of the first secondary winding is connected to the anode of the third diode and the cathode of the fourth diode, respectively; the first end of the second secondary winding is connected to the anode of the fifth diode and the cathode of the sixth diode, respectively; the second end of the second secondary winding is connected to the anode of the seventh diode and the cathode of the eighth diode, respectively.

[0009] Optionally, the first switching circuit includes a third switch, a fourth switch, and a fifth switch; One end of the third switch is connected to the anode of the second diode and the anode of the fourth diode, and the other end of the third switch is connected to the cathode of the fifth diode and the cathode of the seventh diode. One end of the fourth switch is connected to the cathode of the first diode and the cathode of the third diode, and the other end of the fourth switch is connected to the cathode of the fifth diode and the cathode of the seventh diode. One end of the fifth switch is connected to the anode of the second diode and the anode of the fourth diode, and the other end of the fifth switch is connected to the anode of the sixth diode and the anode of the eighth diode.

[0010] Optionally, the output filtering circuit includes a first output filtering inductor and a filtering capacitor; One end of the first output filter inductor is connected to one end of the fourth switch, and the other end of the first output filter inductor is connected to one end of the filter capacitor and one end of the first resistor, respectively. The other end of the filter capacitor is connected to the other end of the first resistor and the other end of the fifth switch, respectively.

[0011] Optionally, the ACDC circuit includes a second primary-side conversion circuit, the main transformer includes a second primary-side winding, and the second primary-side conversion circuit is connected to the three-phase input filter inductor and the second primary-side winding, respectively.

[0012] Optionally, the switching sequence in the first bidirectional switching circuit is as follows: when the input current corresponding to the first bidirectional switching circuit is greater than a preset current value, the first switch connected to the first input filter inductor is turned on according to the preset sequence, and the second switch is turned on a preset time period earlier than the preset sequence; when the input current corresponding to the first bidirectional switching circuit is less than or equal to the preset current value, the first switch and the second switch are turned on according to the preset sequence.

[0013] Secondly, embodiments of the present invention provide a power supply device, which includes the AC / DC circuit of the first aspect.

[0014] Implementing the embodiments of this utility model has the following beneficial effects: As can be seen, this utility model embodiment presents an ACDC circuit that adopts a single-stage ACDC topology, reducing the number of components used in the circuit and thus saving costs. By setting a first switching circuit to switch the series and parallel connection of the first rectifier circuit and the second rectifier circuit, a wide voltage output can be achieved. Furthermore, the zero-voltage turn-on of the switching transistor can be achieved through the timing control of the switching transistor. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 An architecture diagram of an ACDC circuit provided in an embodiment of this application; Figure 2 This is a circuit diagram of an ACDC circuit provided in an embodiment of this application; Figure 3 This application provides a timing waveform diagram of an input voltage according to an embodiment; Figure 4 This is a timing diagram of an input voltage provided in the embodiment itself; Figure 5 This is a circuit diagram of another ACDC circuit provided in the embodiment itself; Figure 6 This is a circuit diagram of yet another ACDC circuit provided in this application embodiment; Figure 7 This is an architectural diagram of a power supply device provided in an embodiment. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0018] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and drawings of this utility model are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0019] In this document, the term "embodiment" means that a particular feature, result, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] To facilitate understanding of the technical solution of this application, the relevant technologies involved in this application will be introduced first.

[0021] See Figure 1 and Figure 2 , Figure 1 This application provides an architecture diagram of an ACDC circuit. Figure 2 This is a circuit diagram of an ACDC circuit provided in an embodiment of this application.

[0022] like Figure 1 As shown, the ACDC circuit includes a three-phase input voltage source 10, a three-phase input filter inductor 20, a first primary-side conversion circuit 30, a main transformer 40, an output rectifier circuit 50, a first switching circuit 60, an output filter circuit 70, and a first resistor Ro.

[0023] The three-phase input filter inductor 20 is connected to the three-phase input voltage source 10. The first primary-side conversion circuit 30 includes a first bidirectional switching circuit, a second bidirectional switching circuit, a third bidirectional switching circuit, a fourth bidirectional switching circuit, a fifth bidirectional switching circuit, a sixth bidirectional switching circuit, a first inductor, and a first capacitor. The two ends of the first bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first inductor L1. The two ends of the second bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first inductor L1. The two ends of the third bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first inductor L1. The fourth bidirectional switching circuit... The two ends of the circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first capacitor C1. The two ends of the fifth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first capacitor C1. The two ends of the sixth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor 20 and one end of the first capacitor C1. The first end of the first primary winding of the main transformer is connected to the other end of the first inductor L1. The second end of the first primary winding of the main transformer 40 is connected to the other end of the first capacitor C1. The output rectifier circuit 50 is respectively connected to the secondary winding and the first switching circuit 60. The output filter circuit 70 is respectively connected to the first switching circuit 60 and the first resistor Ro.

[0024] In one possible example, the three-phase input voltage source 10 includes a first voltage source Va, a second voltage source Vb, and a third voltage source Vc, and the three-phase input filter inductor 20 includes a first input filter inductor La, a second input filter inductor Lb, and a third input filter inductor Lc; the two ends of the first input filter inductor La are respectively connected to the first voltage source Va and the first bidirectional switching circuit, the two ends of the second input filter inductor Lb are respectively connected to the second voltage source Vb and the second bidirectional switching circuit, and the two ends of the third input filter inductor Lc are respectively connected to the third voltage source Vc and the third bidirectional switching circuit.

[0025] Where ia represents the input current corresponding to the first voltage source Va, ib represents the input current corresponding to the second voltage source Vb, ic represents the input current corresponding to the third voltage source Vc, io represents the output current, Cia represents the input filter capacitor corresponding to the first voltage source Va, Cib represents the input filter capacitor corresponding to the second voltage source Vb, Cic represents the input filter capacitor corresponding to the third voltage source Vc, Vo+ represents the positive terminal of the output voltage, and Vo- represents the negative terminal of the output voltage.

[0026] Among them, the first voltage source Va, the second voltage source Vb, and the third voltage source Vc are the voltage sources corresponding to phase A, phase B, and phase C, respectively.

[0027] In one possible example, the first bidirectional switching circuit includes a first switch Q1 and a second switch Q2; the second bidirectional switching circuit includes a third switch Q3 and a fourth switch Q4; the third bidirectional switching circuit includes a fifth switch Q5 and a sixth switch Q6; the fourth bidirectional switching circuit includes a seventh switch Q7 and an eighth switch Q8; the fifth bidirectional switching circuit includes a ninth switch Q9 and a tenth switch Q10; and the sixth bidirectional switching circuit includes an eleventh switch Q11 and a twelfth switch Q12; the two ends of the first switch Q1 are respectively connected to... The other end of the first input filter inductor La is connected to one end of the second switch Q2, and the other end of the second switch Q2 is connected to one end of the first inductor L1; the two ends of the third switch Q3 are respectively connected to the other end of the second input filter inductor Lb and one end of the fourth switch Q4, and the other end of the fourth switch Q4 is connected to one end of the first inductor L1; the two ends of the fifth switch Q5 are respectively connected to the other end of the third input filter inductor Lc and one end of the sixth switch Q6, and the other end of the sixth switch Q6 is connected to one end of the first inductor L1; The two ends of the seventh switch Q7 are respectively connected to the other end of the first input filter inductor La and one end of the eighth switch Q8, and the other end of the eighth switch Q8 is connected to one end of the first capacitor C1; the two ends of the ninth switch Q9 are respectively connected to the other end of the second input filter inductor Lb and one end of the tenth switch Q10, and the other end of the tenth switch Q10 is connected to one end of the first capacitor C1; the two ends of the eleventh switch Q11 are respectively connected to the other end of the third input filter inductor Lc and one end of the twelfth switch Q12, and the other end of the twelfth switch Q12 is connected to one end of the first capacitor C1.

[0028] Where Vp and Vn are both point voltages, and Vp1 and Vn1 are both point voltages.

[0029] In one possible example, the ACDC circuit includes a second switching circuit, which includes a first switch S1 and a second switch S2; the first switch S1 is connected to the other end of the first inductor L1 and the first end of the first primary winding of the main transformer 40, respectively, and the second switch S2 is connected to the other end of the first inductor L1 and the third end of the first primary winding, respectively.

[0030] In one possible example, the output rectifier circuit 50 includes a first rectifier circuit and a second rectifier circuit. The first rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The second rectifier circuit includes a fifth diode D5, a sixth diode D6, a seventh diode D7, and an eighth diode D8. The main transformer includes a first secondary winding and a second secondary winding. The first end of the first secondary winding is connected to the anode of the first diode D1 and the cathode of the second diode D2, respectively. The second end of the first secondary winding is connected to the anode of the third diode D3 and the cathode of the fourth diode D4, respectively. The first end of the second secondary winding is connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6, respectively. The second end of the second secondary winding is connected to the anode of the seventh diode D7 and the cathode of the eighth diode D8, respectively.

[0031] In one possible example, the first switching circuit includes a third switch S3, a fourth switch S4, and a fifth switch S5; One end of the third switch S3 is connected to the anode of the second diode D2 and the anode of the fourth diode D4, respectively. The other end of the third switch S3 is connected to the cathode of the fifth diode D5 and the cathode of the seventh diode D7, respectively. One end of the fourth switch S4 is connected to the cathode of the first diode D1 and the cathode of the third diode D3, respectively. The other end of the fourth switch S4 is connected to the cathode of the fifth diode D5 and the cathode of the seventh diode D7, respectively. One end of the fifth switch S5 is connected to the anode of the second diode D2 and the anode of the fourth diode D4, respectively. The other end of the fifth switch S5 is connected to the anode of the sixth diode D6 and the anode of the eighth diode D8, respectively.

[0032] In one possible example, the output filter circuit includes a first output filter inductor Lf1, a second output filter inductor Lf2, and a filter capacitor Co; One end of the first output filter inductor Lf1 is connected to one end of the fourth switch S4, and the other end of the first output filter inductor Lf1 is connected to one end of the filter capacitor Co and one end of the first resistor Ro, respectively. One end of the second output filter inductor Lf2 is connected to the anode of the eighth diode D8, and the other end of the second output filter inductor Lf2 is connected to the other end of the fifth switch S5. The other end of the filter capacitor Co is connected to the other end of the first resistor Ro and the other end of the fifth switch S5, respectively.

[0033] Please see Figure 3 , Figure 3This is a timing waveform diagram of an input voltage provided in an embodiment of this application. The timing waveform diagram shows a total of 12 working sectors from t0 to t12. Taking t11-t12 as an example, the phase voltage relationship is Vc>0>Va>Vb. At this time, the five level states of the Vpn voltage obtained through six sets of bidirectional switches are Vcb, Vab, 0V, -Vab, and -Vcb, respectively. The specific driving timing of the bidirectional switches is as follows: Figure 4 As shown, the overall wave generation control logic is as follows: First, select the phase voltage with the highest absolute value among Vc, Va, and Vb to obtain Vc. Then, the two line voltages Vcb and Vca associated with Vc can be obtained. The five levels for five-level energy transmission wave generation are Vcb, Vab, 0V, -Vab, and -Vcb. To ensure maximum energy transmission capability, in a single switching cycle, when Vcb > Vca, the energy transmission sequence of the CB two-phase line voltage precedes the energy transmission sequence of the CA two-phase line voltage. The 0-level energy transmission is obtained by closing the two bidirectional switches of the upper and lower phases of phase C to ensure the continuous flow of the energy transmission circuit. To ensure zero-voltage turn-on of the bidirectional switch, the following logic needs to be executed. When the current direction from the AC input port to the converter is defined as positive, the three-phase currents ia, ib, and ic can be obtained. In the current timing sequence, ic > 0 > ia > ib. When the current of phase x (x is any one of phases A, B, and C) is greater than 0 (preset current value), the turn-on timing of the upper bidirectional switch corresponding to phase x should be such that the switch directly connected to the first input filter inductor turns on tf (preset time period) in advance, while the other switch turns on normally according to the current preset timing sequence of the bidirectional switch, ensuring that this switch can achieve zero-voltage turn-on. Similarly, the turn-on timing of the lower bidirectional switch corresponding to phase x should be such that the switch directly connected to the first input filter inductor turns on tf in advance, while the other switch turns on normally according to the current preset timing sequence of the bidirectional switch, ensuring that this switch can achieve zero-voltage turn-on.

[0034] For example, when the input current corresponding to the first bidirectional switching circuit is greater than 0, the first switch Q1 connected to the first input filter inductor turns on according to a preset timing sequence, the second switch Q2 turns on a preset time period earlier than the preset timing sequence, the third switch Q3 connected to the first input filter inductor turns on according to a preset timing sequence, and the fourth switch Q4 turns on a preset time period earlier than the preset timing sequence; when the input current corresponding to the first bidirectional switching circuit is less than or equal to a preset current value, the first switch Q1 and the second switch Q2 turn on according to a preset timing sequence, and the third switch Q3 and the fourth switch Q4 turn on according to a preset timing sequence.

[0035] The preset timing sequence and preset time period can be set manually or by system default, and no restrictions are imposed here.

[0036] Among them, the working range of the four transformer energy transfer voltage ratios is realized by controlling the switches S1 / S2 / S3 / S4 / S5, namely the parallel low voltage range, the parallel high voltage range, the series low voltage range, and the series high voltage range, thereby realizing the output capability of a wide output voltage range. Taking the transformer design turns ratio (i:j is 1:1) as an example: (1) Parallel low voltage range, the method is to close S1, open S2, close S4 and S5, and open S3. The output voltage gain ratio of this working range is: Gv=1 / (i+j). The current output capability is the largest and the voltage output capability is the largest in this working range. (1) Small, suitable for low voltage and high current output; (2) Parallel high voltage range, the method is to close S2, open S1, close S4 and S5, open S3, the output voltage gain ratio in this working range is: Gv=1 / j; (3) Series low voltage range, the method is to close S1, open S2, open S4 and S5, open S3, the output voltage gain ratio in this working range is: Gv=2 / (i+j); (4) Series low voltage range, the method is to close S2, open S1, open S4 and S5, open S3, the output voltage gain ratio in this working range is: Gv=2 / j.

[0037] Please see Figure 5 and Figure 6 , Figure 5 This is a circuit diagram of another ACDC circuit provided in the embodiment itself; Figure 6 This application provides a circuit diagram of another ACDC circuit, which includes a second primary-side conversion circuit and a second primary-side winding of the main transformer. The second primary-side conversion circuit is connected to the three-phase input filter inductor 20 and the second primary-side winding, respectively.

[0038] The second primary-side conversion circuit includes a seventh bidirectional switching circuit, an eighth bidirectional switching circuit, a ninth bidirectional switching circuit, a tenth bidirectional switching circuit, an eleventh bidirectional switching circuit, a twelfth bidirectional switching circuit, a second inductor L2, and a second capacitor C2.

[0039] The seventh bidirectional switching circuit includes the thirteenth switch Q13 and the fourteenth switch Q14; the second bidirectional switching circuit includes the fifteenth switch Q15 and the sixteenth switch Q16; the third bidirectional switching circuit includes the seventeenth switch Q17 and the eighteenth switch Q18; the fourth bidirectional switching circuit includes the nineteenth switch Q19 and the twentieth switch Q20; the fifth bidirectional switching circuit includes the twenty-first switch Q21 and the twenty-second switch Q22; and the sixth bidirectional switching circuit includes the twenty-third switch Q23 and the twenty-fourth switch Q24. The two ends of the thirteenth switch Q13 are connected to the other end of the first input filter inductor La and one end of the fourteenth switch Q14, respectively. The other end of the fourteenth switch Q14 is connected to one end of the second inductor L2. The two ends of the fifteenth switch Q15 are connected to the other end of the second input filter inductor Lb and one end of the sixteenth switch Q16, respectively. The other end of switch Q16 is connected to one end of the second inductor L2; the two ends of the seventeenth switch Q17 are respectively connected to the other end of the third input filter inductor Lc and one end of the eighteenth switch Q18, and the other end of the eighteenth switch Q18 is connected to one end of the second inductor L2; the two ends of the nineteenth switch Q19 are respectively connected to the other end of the first input filter inductor La and one end of the twentieth switch Q20, and the other end of the twentieth switch Q20 is connected to one end of the second capacitor C2; the two ends of the twenty-first switch Q21 are respectively connected to the other end of the second input filter inductor Lb and one end of the twenty-second switch Q22, and the other end of the twenty-second switch Q22 is connected to one end of the second capacitor C2; the two ends of the twenty-third switch Q23 are respectively connected to the other end of the third input filter inductor Lc and one end of the twenty-fourth switch Q24, and the other end of the twenty-fourth switch Q24 is connected to one end of the second capacitor C2.

[0040] The other end of the second inductor L2 is connected to the first end of the second primary winding, and the second capacitor C2 is connected to the second end of the second primary winding.

[0041] As can be seen, this ACDC circuit can be expanded to multiple channels, expanding the input filter circuit to two channels, and connecting the inputs in parallel through two high-efficiency isolation circuits with wide output voltage.

[0042] Please see Figure 6 , Figure 6 The ACDC circuit shown includes a third switching circuit, which includes a sixth switch S6 and a seventh switch S7. The sixth switch S6 is connected to the other end of the second inductor L2 and the first end of the second primary winding of the main transformer, respectively. The seventh switch S7 is connected to the other end of the second inductor L2 and the third end of the second primary winding, respectively.

[0043] As can be seen, this utility model embodiment presents an ACDC circuit that adopts a single-stage ACDC topology, reducing the number of components used in the circuit and thus saving costs. By setting a first switching circuit to switch the series and parallel connection of the first rectifier circuit and the second rectifier circuit, a wide voltage output can be achieved. Furthermore, the zero-voltage turn-on of the switching transistor can be achieved through the timing control of the switching transistor.

[0044] Please see Figure 7 , Figure 7 This application provides a power supply device, which includes the aforementioned ACDC circuit.

[0045] Optionally, the three-phase input voltage source 10 includes a first voltage source Va, a second voltage source Vb, and a third voltage source Vc, and the three-phase input filter inductor 20 includes a first input filter inductor La, a second input filter inductor Lb, and a third input filter inductor Lc; the two ends of the first input filter inductor La are respectively connected to the first voltage source Va and the first bidirectional switching circuit, the two ends of the second input filter inductor Lb are respectively connected to the second voltage source Vb and the second bidirectional switching circuit, and the two ends of the third input filter inductor Lc are respectively connected to the third voltage source Vc and the third bidirectional switching circuit.

[0046] Optionally, the first bidirectional switching circuit includes a first switching transistor Q1 and a second switching transistor Q2; the second bidirectional switching circuit includes a third switching transistor Q3 and a fourth switching transistor Q4; the third bidirectional switching circuit includes a fifth switching transistor Q5 and a sixth switching transistor Q6; the fourth bidirectional switching circuit includes a seventh switching transistor Q7 and an eighth switching transistor Q8; the fifth bidirectional switching circuit includes a ninth switching transistor Q9 and a tenth switching transistor Q10; and the sixth bidirectional switching circuit includes an eleventh switching transistor Q11 and a twelfth switching transistor Q12. The two ends of the first switching transistor Q1 are respectively connected to the first input... The other end of the input filter inductor La is connected to one end of the second switch Q2, and the other end of the second switch Q2 is connected to one end of the first inductor L1; the two ends of the third switch Q3 are respectively connected to the other end of the second input filter inductor Lb and one end of the fourth switch Q4, and the other end of the fourth switch Q4 is connected to one end of the first inductor L1; the two ends of the fifth switch Q5 are respectively connected to the other end of the third input filter inductor Lc and one end of the sixth switch Q6, and the other end of the sixth switch Q6 is connected to one end of the first inductor L1; The two ends of the seventh switch Q7 are respectively connected to the other end of the first input filter inductor La and one end of the eighth switch Q8, and the other end of the eighth switch Q8 is connected to one end of the first capacitor C1; the two ends of the ninth switch Q9 are respectively connected to the other end of the second input filter inductor Lb and one end of the tenth switch Q10, and the other end of the tenth switch Q10 is connected to one end of the first capacitor C1; the two ends of the eleventh switch Q11 are respectively connected to the other end of the third input filter inductor Lc and one end of the twelfth switch Q12, and the other end of the twelfth switch Q12 is connected to one end of the first capacitor C1.

[0047] Optionally, the ACDC circuit includes a second switching circuit, which includes a first switch S1 and a second switch S2; the first switch S1 is connected to the other end of the first inductor L1 and the first end of the first primary winding of the main transformer 40, and the second switch S2 is connected to the other end of the first inductor L1 and the third end of the first primary winding.

[0048] Optionally, the output rectifier circuit 50 includes a first rectifier circuit and a second rectifier circuit. The first rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The second rectifier circuit includes a fifth diode D5, a sixth diode D6, a seventh diode D7, and an eighth diode D8. The main transformer includes a first secondary winding and a second secondary winding. The first end of the first secondary winding is connected to the anode of the first diode D1 and the cathode of the second diode D2, respectively. The second end of the first secondary winding is connected to the anode of the third diode D3 and the cathode of the fourth diode D4, respectively. The first end of the second secondary winding is connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6, respectively. The second end of the second secondary winding is connected to the anode of the seventh diode D7 and the cathode of the eighth diode D8, respectively.

[0049] Optionally, the first switching circuit includes a third switch S3, a fourth switch S4, and a fifth switch S5; One end of the third switch S3 is connected to the anode of the second diode D2 and the anode of the fourth diode D4, respectively. The other end of the third switch S3 is connected to the cathode of the fifth diode D5 and the cathode of the seventh diode D7, respectively. One end of the fourth switch S4 is connected to the cathode of the first diode D1 and the cathode of the third diode D3, respectively. The other end of the fourth switch S4 is connected to the cathode of the fifth diode D5 and the cathode of the seventh diode D7, respectively. One end of the fifth switch S5 is connected to the anode of the second diode D2 and the anode of the fourth diode D4, respectively. The other end of the fifth switch S5 is connected to the anode of the sixth diode D6 and the anode of the eighth diode D8, respectively.

[0050] Optionally, the output filtering circuit includes a first output filtering inductor Lf1, a second output filtering inductor Lf2, and a filtering capacitor Co; One end of the first output filter inductor Lf1 is connected to one end of the fourth switch S4, and the other end of the first output filter inductor Lf1 is connected to one end of the filter capacitor Co and one end of the first resistor Ro, respectively. One end of the second output filter inductor Lf2 is connected to the anode of the eighth diode D8, and the other end of the second output filter inductor Lf2 is connected to the other end of the fifth switch S5. The other end of the filter capacitor Co is connected to the other end of the first resistor Ro and the other end of the fifth switch S5, respectively.

[0051] Optionally, the ACDC circuit includes a second primary-side conversion circuit, the main transformer includes a second primary-side winding, and the second primary-side conversion circuit is connected to the three-phase input filter inductor and the second primary-side winding, respectively.

[0052] Optionally, the switching sequence in the first bidirectional switching circuit is as follows: when the input current corresponding to the first bidirectional switching circuit is greater than a preset current value, the first switch connected to the first input filter inductor is turned on according to the preset sequence, and the second switch is turned on a preset time period earlier than the preset sequence; when the input current corresponding to the first bidirectional switching circuit is less than or equal to the preset current value, the first switch and the second switch are turned on according to the preset sequence.

[0053] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0054] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0055] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0056] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0057] If the aforementioned integrated units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0058] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory, a random access memory, a magnetic disk, or an optical disk, etc.

[0059] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An AC-CDC circuit, characterized in that, The ACDC circuit includes: Three-phase input voltage source; A three-phase input filter inductor is connected to the three-phase input voltage source; The first primary-side conversion circuit includes a first bidirectional switching circuit, a second bidirectional switching circuit, a third bidirectional switching circuit, a fourth bidirectional switching circuit, a fifth bidirectional switching circuit, a sixth bidirectional switching circuit, a first inductor, and a first capacitor. The two ends of the first bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the second bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the third bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first inductor. The two ends of the fourth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The two ends of the fifth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The two ends of the sixth bidirectional switching circuit are respectively connected to one end of the three-phase input filter inductor and one end of the first capacitor. The main transformer has a first end of its first primary winding connected to the other end of the first inductor, and a second end of its first primary winding connected to the other end of the first capacitor. An output rectifier circuit is connected to the secondary winding and the first switching circuit, respectively. An output filtering circuit is provided, which is connected to the first switching circuit and the first resistor.

2. The ACDC circuit according to claim 1, characterized in that, The three-phase input voltage source includes a first voltage source, a second voltage source, and a third voltage source, and the three-phase input filter inductor includes a first input filter inductor, a second input filter inductor, and a third input filter inductor; The two ends of the first input filter inductor are respectively connected to the first voltage source and the first bidirectional switching circuit, the two ends of the second input filter inductor are respectively connected to the second voltage source and the second bidirectional switching circuit, and the two ends of the third input filter inductor are respectively connected to the third voltage source and the third bidirectional switching circuit.

3. The ACDC circuit according to claim 2, characterized in that, The first bidirectional switching circuit includes a first switching transistor and a second switching transistor; the second bidirectional switching circuit includes a third switching transistor and a fourth switching transistor; the third bidirectional switching circuit includes a fifth switching transistor and a sixth switching transistor; the fourth bidirectional switching circuit includes a seventh switching transistor and an eighth switching transistor; the fifth bidirectional switching circuit includes a ninth switching transistor and a tenth switching transistor; and the sixth bidirectional switching circuit includes an eleventh switching transistor and a twelfth switching transistor. The two ends of the first switching transistor are respectively connected to the other end of the first input filter inductor and one end of the second switching transistor, and the other end of the second switching transistor is connected to one end of the first inductor; the two ends of the third switching transistor are respectively connected to the other end of the second input filter inductor and one end of the fourth switching transistor, and the other end of the fourth switching transistor is connected to one end of the first inductor; the two ends of the fifth switching transistor are respectively connected to the other end of the third input filter inductor and one end of the sixth switching transistor, and the other end of the sixth switching transistor is connected to one end of the first inductor. The two ends of the seventh switch are respectively connected to the other end of the first input filter inductor and one end of the eighth switch, and the other end of the eighth switch is connected to one end of the first capacitor; the two ends of the ninth switch are respectively connected to the other end of the second input filter inductor and one end of the tenth switch, and the other end of the tenth switch is connected to one end of the first capacitor; the two ends of the eleventh switch are respectively connected to the other end of the third input filter inductor and one end of the twelfth switch, and the other end of the twelfth switch is connected to one end of the first capacitor.

4. The ACDC circuit according to claim 3, characterized in that, The ACDC circuit includes a second switching circuit, which includes a first switch and a second switch. The first switch is connected to the other end of the first inductor and the first end of the first primary winding of the main transformer, and the second switch is connected to the other end of the first inductor and the third end of the first primary winding.

5. The AC-CDC circuit according to claim 1, characterized in that, The output rectifier circuit includes a first rectifier circuit and a second rectifier circuit. The first rectifier circuit includes a first diode, a second diode, a third diode, and a fourth diode. The second rectifier circuit includes a fifth diode, a sixth diode, a seventh diode, and an eighth diode. The main transformer includes a first secondary winding and a second secondary winding. The first end of the first secondary winding is connected to the anode of the first diode and the cathode of the second diode, respectively; the second end of the first secondary winding is connected to the anode of the third diode and the cathode of the fourth diode, respectively; the first end of the second secondary winding is connected to the anode of the fifth diode and the cathode of the sixth diode, respectively; the second end of the second secondary winding is connected to the anode of the seventh diode and the cathode of the eighth diode, respectively.

6. The ACDC circuit according to claim 5, characterized in that, The first switching circuit includes a third switch, a fourth switch, and a fifth switch; One end of the third switch is connected to the anode of the second diode and the anode of the fourth diode, and the other end of the third switch is connected to the cathode of the fifth diode and the cathode of the seventh diode. One end of the fourth switch is connected to the cathode of the first diode and the cathode of the third diode, and the other end of the fourth switch is connected to the cathode of the fifth diode and the cathode of the seventh diode. One end of the fifth switch is connected to the anode of the second diode and the anode of the fourth diode, and the other end of the fifth switch is connected to the anode of the sixth diode and the anode of the eighth diode.

7. The AC-CDC circuit according to claim 6, characterized in that, The output filtering circuit includes a first output filtering inductor and a filtering capacitor; One end of the first output filter inductor is connected to one end of the fourth switch, and the other end of the first output filter inductor is connected to one end of the filter capacitor and one end of the first resistor, respectively. The other end of the filter capacitor is connected to the other end of the first resistor and the other end of the fifth switch, respectively.

8. The ACDC circuit according to claim 1, characterized in that, The ACDC circuit includes a second primary-side conversion circuit, and the main transformer includes a second primary-side winding. The second primary-side conversion circuit is connected to the three-phase input filter inductor and the second primary-side winding, respectively.

9. The ACDC circuit according to claim 8, characterized in that, The ACDC circuit includes a third switching circuit, which is connected to the second primary winding and the second primary transformation circuit respectively.

10. A power supply device, characterized in that, The power supply device includes the AC / DC circuit as described in any one of claims 1-9.

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