Three-phase coupling staggered DC-DC circuit and converter

Abstract

The utility model relates to the technical field of power circuits, and discloses a three-phase coupling staggered DC-DC circuit and a converter, and the circuit comprises a first primary side assembly, a second primary side assembly, a third primary side assembly, a first transformer, a second transformer, a third transformer, a first secondary side assembly, a second secondary side assembly, and a third secondary side assembly. Multiple working states are generated in the working process through working time sequence phase dislocation of the first primary side assembly, the second primary side assembly and the third primary side assembly, so that the equivalent relation of the circuit is changed for multiple times to reduce the difference of equivalent parameters of the circuit, and the influence caused by the difference of device parameters of the primary side assemblies is further weakened.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of power circuit, and particularly relates to a three-phase coupled interleaved DC-DC circuit and a converter. BACKGROUND

[0002] In a high-power application, a multi-parallel technology is usually used, that is, a plurality of same small-power circuits are connected in parallel to achieve the effect of multiplying the total power. However, due to the difference in device parameters, it is impossible to ensure that the device parameters, action logic timing, control and sampling of each circuit in the multi-parallel connection are exactly the same. Therefore, uneven current will inevitably occur, which will cause the power of a certain circuit in the multi-parallel connection to be greater than the power of other circuits, thereby causing the multi-parallel connection circuit to fail to work normally.

[0003] At present, the solutions for avoiding uneven current in multi-parallel connection mainly include passive current sharing and active current sharing. The passive current sharing mainly realizes current sharing by adding additional current sharing devices (for example, current sharing reactors, current sharing resistors, etc.), and the principle is that different currents flowing through the current sharing devices will produce different voltage drops. For example, the droop control method of passive current sharing is to connect a same current sharing reactor in series in each parallel circuit. The voltage drop generated on the reactor by the circuit with a larger current is higher, and the voltage drop generated on the reactor by the circuit with a smaller current is lower, so that the degree of uneven current can be reduced by voltage drop adjustment. The active current sharing mainly relies on a software control method, which collects the current of each circuit in multi-parallel connection and adjusts the current of each circuit in real time to reduce the degree of uneven current of each circuit. For example, the droop control method of active current sharing is to collect the output current of each circuit respectively and adjust the output voltage of each circuit according to the size of the output current. If the output current is large, the output voltage is lowered. The larger the output current of a circuit is, the smaller the output current of the circuit tends to be, thereby reducing the output and achieving the effect of current sharing.

[0004] However, the passive current sharing described above needs to add additional current sharing devices, and the active current sharing described above needs to rely on a complex control method. Therefore, the prior art still needs to be improved. CONTENT OF THE UTILITY MODEL

[0005] In view of the defects in the prior art, the present disclosure provides a three-phase coupled interleaved DC-DC circuit and a converter, which aims to solve the technical problems that the passive current sharing in the related art needs to add additional current sharing devices, and the active current sharing needs to rely on a complex control method.

[0006] The technical solution adopted by the present disclosure to solve the above technical problems is as follows:

[0007] The present disclosure discloses a three-phase coupled interleaved DC-DC circuit, comprising:

[0008] The first primary assembly includes a first DC connection end, a second DC connection end, and a first AC output end; the first DC connection end is connected to the positive pole of the DC input, and the second DC connection end is connected to the negative pole of the DC input;

[0009] The first transformer; the first end of the primary winding of the first transformer is connected to the first AC output end;

[0010] The second primary assembly is connected in parallel with the first primary assembly and includes a third DC connection end, a fourth DC connection end, and a second AC output end; the third DC connection end is connected to the positive pole of the DC input, and the fourth DC connection end is connected to the negative pole of the DC input;

[0011] The second transformer; the first end of the primary winding of the second transformer is connected to the second AC output end;

[0012] The third primary assembly is connected in parallel with the first primary assembly and the second primary assembly and includes a fifth DC connection end, a sixth DC connection end, and a third AC output end; the fifth DC connection end is connected to the positive pole of the DC input, and the sixth DC connection end is connected to the negative pole of the DC input;

[0013] The third transformer; the first end of the primary winding of the third transformer is connected to the third AC output end; the second end of the primary winding of the third transformer, the second end of the primary winding of the second transformer, and the second end of the primary winding of the first transformer are star-connected;

[0014] The first secondary assembly; the first secondary assembly is connected to the secondary winding of the first transformer and the DC output, respectively;

[0015] The second secondary assembly is connected in parallel with the first secondary assembly; the second secondary assembly is connected to the secondary winding of the second transformer and the DC output, respectively; and

[0016] The third secondary assembly is connected in parallel with the first secondary assembly and the second secondary assembly; the third secondary assembly is connected to the secondary winding of the third transformer and the DC output, respectively;

[0017] The working time sequence of the first primary assembly, the second primary assembly, and the third primary assembly is out of phase.

[0018] In some embodiments, the working time sequence of the first primary assembly, the second primary assembly, and the third primary assembly is out of phase by 120 degrees in turn.

[0019] In some embodiments, the first primary assembly, the second primary assembly, and / or the third primary assembly includes:

[0020] a first switch; a first terminal of the first switch is connected to a positive pole of the DC input;

[0021] a second switch; a first terminal of the second switch is connected to a negative pole of the DC input, and a second terminal of the second switch is connected to a second terminal of the first switch; and

[0022] an inductor; a first terminal of the inductor is connected between the second terminal of the first switch and the second terminal of the second switch, and a second terminal of the inductor is an AC output terminal of the primary side assembly.

[0023] In some embodiments, the first primary side assembly, the second primary side assembly, and / or the third primary side assembly comprises:

[0024] a first switch; a first terminal of the first switch is connected to a positive pole of the DC input;

[0025] a second switch; a first terminal of the second switch is connected to a second terminal of the first switch;

[0026] a third switch; a first terminal of the third switch is connected to a second terminal of the second switch;

[0027] an inductor; a first terminal of the inductor is connected between the second terminal of the second switch and the first terminal of the third switch, and a second terminal of the inductor is an AC output terminal of the primary side assembly.

[0028] a fourth switch; a first terminal of the fourth switch is connected to a second terminal of the third switch, and a second terminal of the fourth switch is connected to a negative pole of the DC input; and

[0029] a capacitor; a first terminal of the capacitor is connected between the second terminal of the first switch and the first terminal of the second switch, and a second terminal of the capacitor is connected between the second terminal of the third switch and the first terminal of the fourth switch.

[0030] In some embodiments, the first primary side assembly, the second primary side assembly, and / or the third primary side assembly comprises:

[0031] a first switch; a first terminal of the first switch is connected to a positive pole of the DC input;

[0032] a second switch; a first terminal of the second switch is connected to a second terminal of the first switch;

[0033] a third switch; a first terminal of the third switch is connected to a second terminal of the second switch;

[0034] an inductor; a first terminal of the inductor is connected between the second terminal of the second switch and the first terminal of the third switch, and a second terminal of the inductor is an AC output terminal of the primary side assembly.

[0035] a fourth switch, a first end of the fourth switch being connected to a second end of the third switch, and a second end of the fourth switch being connected to a negative pole of the DC input;

[0036] a first capacitor, a first end of the first capacitor being connected between a positive pole of the DC input and a first end of the first switch;

[0037] a second capacitor, a first end of the second capacitor being connected to a second end of the first capacitor, and a second end of the second capacitor being connected to a negative pole of the DC input;

[0038] a first diode, a cathode of the first diode being connected between a second end of the first switch and a first end of the second switch, and an anode of the first diode being connected between a second end of the first capacitor and a first end of the second capacitor; and

[0039] a second diode, a cathode of the second diode being connected between a second end of the first capacitor and a first end of the second capacitor, and an anode of the second diode being connected between a second end of the third switch and a first end of the fourth switch.

[0040] In some embodiments, the first end and the second end of the first secondary assembly are connected to a first end and a second end of a secondary winding of the first transformer, respectively, and the third end and the fourth end of the first secondary assembly are connected to a positive pole and a negative pole of the DC output, respectively;

[0041] the first end and the second end of the second secondary assembly are connected to a first end and a second end of a secondary winding of the second transformer, respectively, and the third end and the fourth end of the second secondary assembly are connected to a positive pole and a negative pole of the DC output, respectively;

[0042] the first end and the second end of the third secondary assembly are connected to a first end and a second end of a secondary winding of the third transformer, respectively, and the third end and the fourth end of the third secondary assembly are connected to a positive pole and a negative pole of the DC output, respectively;

[0043] the first secondary assembly, the second secondary assembly, and / or the third secondary assembly are the same full-bridge rectifier circuit.

[0044] In some embodiments, the full-bridge rectifier circuit comprises:

[0045] a first secondary switch, a first end of the first secondary switch being connected to a positive pole of the DC output;

[0046] a second secondary switch, a first end of the second secondary switch being connected to a second end of the first secondary switch, and a second end of the second secondary switch being connected to a negative pole of the DC output.

[0047] a third auxiliary switch, a first end of the third auxiliary switch being connected to a second end of the second auxiliary switch and a negative pole of the DC output, and

[0048] a fourth auxiliary switch, a first end of the fourth auxiliary switch being connected to a second end of the third auxiliary switch, and a second end of the fourth auxiliary switch being connected to a first end of the first auxiliary switch and a positive pole of the DC output;

[0049] wherein a first end of an auxiliary winding of the transformer is connected between a second end of the third auxiliary switch and a first end of the fourth auxiliary switch, and a second end of the auxiliary winding of the transformer is connected between a second end of the second auxiliary switch and a first end of the first auxiliary switch.

[0050] In some embodiments, the first auxiliary switch, the second auxiliary switch, the third auxiliary switch, and the fourth auxiliary switch are all the same transistor.

[0051] In some embodiments, the circuit further comprises:

[0052] a first capacitor connected between a first end of the primary winding of the first transformer and the first AC output terminal; and / or

[0053] a second capacitor connected between a first end of the primary winding of the second transformer and the second AC output terminal; and / or

[0054] a third capacitor connected between a first end of the primary winding of the third transformer and the third AC output terminal.

[0055] In addition, the present disclosure also provides a three-phase coupled interleaved DC-DC converter, comprising a DC input, a DC output, and the three-phase coupled interleaved DC-DC circuit as described above; the DC input and the DC output are both connected to the three-phase coupled interleaved DC-DC circuit.

[0056] Beneficial effects: the present disclosure can generate multiple working states during operation through the three-phase coupled interleaved DC-DC circuit, so that the equivalent relationship of the circuit changes multiple times to reduce the difference of the equivalent parameters of the circuit, and thus the influence of the difference of the device parameters of the primary side components is weakened. Therefore, the present disclosure does not need to increase additional current sharing devices, and can solve the problem of uneven current without relying on complex control methods. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present disclosure, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0058] Figure 1 is a circuit structure schematic diagram of a three-phase coupled interleaved DC-DC circuit provided by some embodiments of the present disclosure.

[0059] Figure 2 is a working period schematic diagram of a three-phase coupled interleaved DC-DC circuit provided by some embodiments of the present disclosure.

[0060] Figure 3 is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T1 time period provided by some embodiments of the present disclosure.

[0061] Figure 4 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T1 time period provided by some embodiments of the present disclosure.

[0062] Figure 5 is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T2 time period provided by some embodiments of the present disclosure.

[0063] Figure 6 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T2 time period provided by some embodiments of the present disclosure.

[0064] Figure 7 is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T3 time period provided by some embodiments of the present disclosure.

[0065] Figure 8 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T3 time period provided by some embodiments of the present disclosure.

[0066] Figure 9 is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T4 time period provided by some embodiments of the present disclosure.

[0067] Figure 10 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T4 time period provided by some embodiments of the present disclosure.

[0068] Figure 11is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T5 time period according to some embodiments of the present disclosure.

[0069] Figure 12 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T5 time period according to some embodiments of the present disclosure.

[0070] Figure 13 is a current loop state schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T6 time period according to some embodiments of the present disclosure.

[0071] Figure 14 is an equivalent current schematic diagram of a three-phase coupled interleaved DC-DC circuit in a T6 time period according to some embodiments of the present disclosure.

[0072] Figure 15 is a schematic diagram of a primary side component of a three-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure.

[0073] Figure 16 is another schematic diagram of a primary side component of a three-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure.

[0074] Figure 17 is yet another schematic diagram of a primary side component of a three-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure.

[0075] Figure 18 is another schematic diagram of a three-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure.

[0076] Figure 19 is a schematic diagram of a secondary side component of a three-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure.

[0077] Figure 20 is a schematic diagram of a multi-phase coupled interleaved DC-DC circuit according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0078] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further understood that the terms "comprise" (or comprise), "comprises" (or comprises) "comprising" (or comprising), "includes" (or include), "including" (or including), "has" (or have), "having" (or having) or variants thereof are open-ended, and include one or more entities discussed, but also contain the possibilities of adding one or more other entities to those discussed. It is to be understood that where the term "connected" or "coupled" is used herein, it is understood that, while items so connected or coupled can be directly connected or coupled, additional items can also be present. Additionally, reference to something being "connected" or "coupled" to something else can mean that the referenced items are either directly or indirectly connected or coupled. Further, use of "connection" or "coupling" herein also includes wireless connection or wireless coupling. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0079] It is to be understood that the terms so used are intended to encompass common and accepted meanings in the art, unless otherwise expressly specified. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0080] Reference is made to Figure 1 The present disclosure provides a three-phase coupled interleaved DC-DC circuit, comprising: a first primary component A1, a second primary component B1, a third primary component C1, a first transformer T1, a second transformer T2, a third transformer T3, a first secondary component A2, a second secondary component B2, and a third secondary component C2. The first primary component A1 comprises: a first DC connection end, a second DC connection end, and a first AC output end; the first DC connection end is connected to the positive pole of a DC input DC1, the second DC connection end is connected to the negative pole of the DC input DC1, and the first AC output end is connected to the first end of the primary winding of the first transformer T1 (see Figure 18 The first end of the primary winding of the first transformer T1 and the first AC output end can be connected to a first capacitor c61, i.e., the c61 is connected in series in the loop formed by the first primary component A1 and the primary winding of the first transformer T1, which functions to conduct AC isolation DC and prevents transformer saturation). The second primary component B1 comprises: a third DC connection end, a fourth DC connection end, and a second AC output end; the third DC connection end is connected to the positive pole of the DC input DC1, the fourth DC connection end is connected to the negative pole of the DC input DC1, and the second AC output end is connected to the first end of the primary winding of the second transformer T2 (see Figure 18, the first end of the primary winding of the second transformer T2 and the second AC output end can be connected with a second capacitor c62, that is, the c62 is connected in series in the loop composed of the second primary component B1 and the primary winding of the second transformer T2, which plays a role of conducting AC isolation DC and prevents transformer saturation. The third primary component C1 comprises a fifth DC connection end, a sixth DC connection end and a third AC output end; the fifth DC connection end is connected with the positive pole of the DC input DC1, the sixth DC connection end is connected with the negative pole of the DC input DC1, and the third AC output end is connected with the first end of the primary winding of the third transformer T3 (see Figure 18 , the first end of the primary winding of the third transformer T3 and the third AC output end can be connected with a third capacitor c63, that is, the c63 is connected in series in the loop composed of the third primary component C1 and the primary winding of the third transformer T3, which plays a role of conducting AC isolation DC and prevents transformer saturation. The first primary component A1, the second primary component B1 and the third primary component C1 are connected in parallel and are independent of each other without coupling. The second end of the primary winding of the third transformer T3, the second end of the primary winding of the second transformer T2 and the second end of the primary winding of the first transformer T1 are connected in star; wherein the transformer can be a common isolation transformer on the market, which is not limited here. The first secondary component A2, the second secondary component B2 and the third secondary component C2 are connected in parallel and are independent of each other without coupling. The two sides of the first secondary component A2 are respectively connected with the secondary winding of the first transformer T1 and the DC output DC2, the two sides of the second secondary component B2 are respectively connected with the secondary winding of the second transformer T2 and the DC output DC2, and the third secondary component C2 is respectively connected with the secondary winding of the third transformer T3 and the DC output DC2. Wherein, the working time sequence of the first primary component A1, the second primary component B1 and the third primary component C1 is out of phase, so that the three-phase coupled interleaved DC-DC circuit can produce multiple working states in the working process, so that the equivalent relationship of the circuit changes multiple times to reduce the difference of the equivalent parameters of the circuit, and then the influence of the difference of the device parameters of the primary component is weakened. Therefore, the disclosure does not need to increase additional current sharing devices, and can solve the problem of uneven current without relying on complex control methods.

[0081] In some embodiments, the working time sequence of the first primary component A1, the second primary component B1 and the third primary component C1 is out of phase by 120 degrees in turn, so that the three-phase coupled interleaved DC-DC circuit includes six working states as shown in Figure 2 in each complete period (the working state in one period and the working state in the next period are exactly the same).

[0082] The circuit working state in the T1 time period is shown in Figure 3, the first primary component A1 is positive polarity conduction, the second primary component B1 is negative polarity conduction, and the third primary component C1 is positive polarity conduction. The current flows out from the positive pole DC1+ of the direct current input DC1 and then is divided into two branches. The first branch is the A1 positive polarity loop, that is, the current first flows into the first transformer T1 and then flows into the second transformer T2. The second branch is the C1 positive polarity loop, that is, the current first flows into the third transformer T3 and then flows into the second transformer T2. Since the B1 is negative polarity conduction, the current flows into the negative pole DC1- of the direct current input DC1 through the negative polarity loop. From the current loop, the total current passes through the A-phase primary side and then flows to the B-phase and the C-phase. The equivalent circuit form is shown in Figure 4 , A1 and C1 are connected in parallel and then connected in series with B1.

[0083] The circuit working state in the T2 time period is shown in Figure 5 , the first primary component A1 is positive polarity conduction, the second primary component B1 is negative polarity conduction, and the third primary component C1 is negative polarity conduction; that is, compared with the circuit working state in T1, the C1 in T2 changes from positive polarity conduction to negative polarity conduction. The equivalent circuit form is shown in Figure 6 , B1 and C1 are connected in parallel and then connected in series with A1.

[0084] The circuit working state in the T3 time period is shown in Figure 7 , the first primary component A1 is positive polarity conduction, the second primary component B1 is positive polarity conduction, and the third primary component C1 is negative polarity conduction; that is, compared with the circuit working state in T2, the B1 in T3 changes from negative polarity conduction to positive polarity conduction. The equivalent circuit form is shown in Figure 8 , A1 and B1 are connected in parallel and then connected in series with C1.

[0085] The circuit working state in the T4 time period is shown in Figure 9 , the first primary component A1 is negative polarity conduction, the second primary component B1 is positive polarity conduction, and the third primary component C1 is negative polarity conduction; that is, compared with the circuit working state in T3, the A1 in T4 changes from positive polarity conduction to negative polarity conduction. The equivalent circuit form is shown in Figure 10 , A1 and C1 are connected in parallel and then connected in series with B1.

[0086] The circuit working state in the T5 time period is shown in Figure 11 , the first primary component A1 is negative polarity conduction, the second primary component B1 is positive polarity conduction, and the third primary component C1 is positive polarity conduction; that is, compared with the circuit working state in T4, the C1 in T5 changes from negative polarity conduction to positive polarity conduction. The equivalent circuit form is shown in Figure 12 , B1 and C1 are connected in parallel and then connected in series with A1.

[0087] The circuit working state in the T6 time period is shown inFigure 13 , the first primary component A1 is negative polarity conduction, the second primary component B1 is negative polarity conduction, and the third primary component C1 is positive polarity conduction; that is, compared with the circuit working state of T5, C1 of T6 changes from negative polarity conduction to positive polarity conduction. For equivalent circuit forms, please refer to Figure 14 , A1 and B1 are connected in parallel and then connected in series with C1.

[0088] In this embodiment, as can be seen from the equivalent circuit diagram, each primary component loop of the three-phase coupled interleaved DC-DC circuit is coupled with other primary component loops (for example, in the T2 time period, the current of A1 can only form a loop through B1 or C1), therefore, the equivalent parameters of the circuit also change (for example, in the T2 time period, the current in the A1 loop is determined by the device parameters in the single loop, which becomes that the current is determined by the device parameters in the three loops, because the current changes from single loop to multiple loops, so that the coupling between the three loops is generated). Moreover, the working timing of the first primary component A1, the second primary component B1, and the third primary component C1 is staggered by 120 degrees in turn, so that the three-phase coupled interleaved DC-DC circuit has six working states in each complete cycle, so that the equivalent relationship of the circuit changes six times. In the case that the device parameters of a certain primary component (for example, the first primary component A1) are greatly different, because A1 is connected in parallel with B1 and C1 respectively and also connected in series in the loop in a complete working cycle, the change of the multiple working states is equivalent to reducing the device parameter difference of A1, so as to weaken the influence of the large device parameter difference of A1. The difference of the equivalent parameters of the circuit will affect the current unbalance degree of the multiple parallel circuits, and reducing the difference of the equivalent parameters of the circuit can reduce the parallel unbalance degree; therefore, the disclosure actually reduces the difference of the equivalent parameters of the circuit through circuit coupling and interleaving, so as to solve the problem of parallel unbalance.

[0089] In some embodiments, the design idea of the three-phase coupled interleaved DC-DC circuit provided by the disclosure can also be applied to a coupled circuit with more than three phases, please refer to Figure 20 , which will not be described in detail.

[0090] In some embodiments, the first primary component A1, the second primary component A2, and the third primary component A3 can be the same or different.

[0091] In one implementation manner of this embodiment, please refer to Figure 15, the first primary side assembly A1, the second primary side assembly A2, and the third primary side assembly A3 can be a two-level chopper circuit, comprising: a first switch S1, a second switch S2, and an inductor L. A first end of the first switch S1 is connected to a positive pole of the direct current input DC1, a second end of the first switch S1 is connected to a second end of the second switch S2; a first end of the second switch S2 is connected to a negative pole of the direct current input DC1; a first end of the inductor L is connected between the second end of the first switch S1 and the second end of the second switch S2, and a second end of the inductor L is an alternating current output end of the primary side assembly. The first switch S1 and the second switch S2 can be selected from common transistors on the market, which are not limited here. The first switch and the second switch are complementary on and off, so that the positive pole and the negative pole of the direct current input power are connected to one end of the inductor, so that the inductor generates alternating current output to the alternating current output end of the primary side assembly.

[0092] In another implementation manner of the embodiment, referring to Figure 16 , the first primary side assembly A1, the second primary side assembly A2, and the third primary side assembly A3 can be a flying capacitor three-level chopper circuit, comprising: a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a capacitor C, and an inductor L. A first end of the first switch S1 is connected to a positive pole of the direct current input DC1, and a second end of the first switch S1 is connected to a first end of the second switch S2. A second end of the second switch S2 is connected to a first end of the third switch S3. A second end of the third switch S3 is connected to a first end of the fourth switch S4. A second end of the fourth switch S4 is connected to a negative pole of the direct current input DC1. A first end of the inductor L is connected between the second end of the second switch S2 and the first end of the third switch S3, and a second end of the inductor L is an alternating current output end of the primary side assembly. A first end of the capacitor C is connected between the second end of the first switch S1 and the first end of the second switch S2, and a second end of the capacitor C is connected between the second end of the third switch S3 and the first end of the fourth switch S4. The first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 can be selected from common transistors on the market, which are not limited here. The first switch, the second switch, the third switch, and the fourth switch are complementary on and off, so that the positive pole and the negative pole of the direct current input power are connected to one end of the inductor, so that the inductor generates alternating current output to the alternating current output end of the primary side assembly.

[0093] In still another implementation manner of the embodiment, referring to Figure 17The first primary side assembly A1, the second primary side assembly A2, and the third primary side assembly A3 can be a diode clamped three-level chopper circuit, comprising a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first capacitor C1, a second capacitor C2, an inductor L, a first diode D1, and a second diode D2. The first end of the first switch S1 is connected to the positive pole of the DC input DC1, and the second end of the first switch S1 is connected to the first end of the second switch S2. The second end of the second switch S2 is connected to the first end of the third switch S3. The second end of the third switch S3 is connected to the first end of the fourth switch S4. The second end of the fourth switch S4 is connected to the negative pole of the DC input DC1. The first end of the inductor L is connected between the second end of the second switch S2 and the first end of the third switch S3, and the second end of the inductor L is the AC output end of the primary side assembly. The first end of the first capacitor C1 is connected between the positive pole of the DC input DC1 and the first end of the first switch S1, and the second end of the first capacitor C1 is connected to the first end of the second capacitor C2. The second end of the second capacitor C2 is connected to the negative pole of the DC input DC1. The cathode of the first diode D1 is connected between the second end of the first switch S1 and the first end of the second switch S2, and the anode of the first diode D1 is connected between the second end of the first capacitor C1 and the first end of the second capacitor C2. The cathode of the second diode D2 is connected between the second end of the first capacitor C1 and the first end of the second capacitor C2, and the anode of the second diode D2 is connected between the second end of the third switch S3 and the first end of the fourth switch S4. The first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 can be selected from commonly used transistors on the market, which are not limited here. The first switch, the second switch, the third switch, and the fourth switch are complementary on and off, so that the positive pole and the negative pole of the DC input power supply are connected to one end of the inductor, so that the inductor generates an AC output to the AC output end of the primary side assembly; moreover, the two midpoint clamping diodes play a role in preventing voltage from being too high and protecting the circuit.

[0094] In some embodiments, the first end and the second end of the first secondary side assembly A2 are respectively connected to the first end and the second end of the secondary side winding of the first transformer T1, the third end and the fourth end of the first secondary side assembly A2 are respectively connected to the first end and the second end of the secondary side winding of the third transformer T3, and the third end and the fourth end of the third secondary side assembly C2 are respectively connected to the positive pole and the negative pole of the DC output DC2. The first secondary side assembly A2, the second secondary side assembly B2, and the third secondary side assembly C3 can be the same or different; in one implementation, the first secondary side assembly A2, the second secondary side assembly B2, and the third secondary side assembly C3 are the same full-bridge rectifier circuit.

[0095] In one implementation of the present embodiment, please refer to Figure 19The first primary side component A1, the second primary side component A2, and the third primary side component A3 are the same two-level chopper circuit, and the first secondary side component A2, the second secondary side component B2, and the third secondary side component C3 are the same full-bridge rectifier circuit. The full-bridge rectifier circuit comprises a first secondary side switch S01, a second secondary side switch S02, a third secondary side switch S02, and a fourth secondary side switch S04. The first end of the first secondary side switch S01 is connected to the positive pole of the direct current output DC2, and the second end of the first secondary side switch S01 is connected to the first end of the second secondary side switch S02. The second end of the second secondary side switch S02 is connected to the negative pole of the direct current output DC2. The first end of the third secondary side switch S03 is connected to the second end of the second secondary side switch S02 and the negative pole of the direct current output DC2. The first end of the fourth secondary side switch S04 is connected to the second end of the third secondary side switch S03, and the second end of the fourth secondary side switch S04 is connected to the first end of the first secondary side switch S01 and the positive pole of the direct current output DC2. The first end of the secondary side winding of the transformer is connected between the second end of the third secondary side switch S03 and the first end of the fourth secondary side switch S04, and the second end of the secondary side winding of the transformer is connected between the second end of the first secondary side switch S01 and the first end of the second secondary side switch S02. The first secondary side switch S01, the second secondary side switch S02, the third secondary side switch S03, and the fourth secondary side switch S04 can be selected from the same transistors commonly seen on the market, which are not limited here.

[0096] In addition, the disclosure also provides a three-phase coupled interleaved DC-DC converter, comprising a direct current input, a direct current output, and the three-phase coupled interleaved DC-DC circuit described above; the direct current input and the direct current output are connected with the three-phase coupled interleaved DC-DC circuit described above.

[0097] It can be understood that the terms "long", "wide", "high", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "side", "bottom", "inner", and "outer" and the like in the disclosure indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the disclosure.

[0098] It can be understood that the terms "first" and "second" in the disclosure are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the disclosure, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited.

[0099] It can be understood that, unless specifically and expressly defined otherwise, the terms "set", "mounted", "connected", "linked", "fixed" and the like in the disclosure should be understood in a broad sense, for example, can be fixedly connected, can also be detachably connected, or integrated; can be mechanically connected, can also be electrically connected; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the disclosure can be understood according to the specific circumstances.

[0100] The above examples are only used to illustrate the disclosure, but not to limit the scope of the disclosure. Any modification or change made without departing from the spirit of the disclosure shall fall within the protection scope of the disclosure.

Claims

1. A three-phase coupled interleaved DC-DC circuit, characterized by, include: The first primary-side component includes a first DC connection terminal, a second DC connection terminal, and a first AC output terminal; the first DC connection terminal is connected to the positive terminal of the DC input, and the second DC connection terminal is connected to the negative terminal of the DC input; First transformer; the first end of the primary winding of the first transformer is connected to the first AC output terminal; The second primary-side component, connected in parallel with the first primary-side component, includes a third DC connection terminal, a fourth DC connection terminal, and a second AC output terminal; the third DC connection terminal is connected to the positive terminal of the DC input, and the fourth DC connection terminal is connected to the negative terminal of the DC input; The second transformer; the first end of the primary winding of the second transformer is connected to the second AC output terminal; The third primary-side component, connected in parallel with the first and second primary-side components, includes a fifth DC connection terminal, a sixth DC connection terminal, and a third AC output terminal; the fifth DC connection terminal is connected to the positive terminal of the DC input, and the sixth DC connection terminal is connected to the negative terminal of the DC input; The third transformer; the first end of the primary winding of the third transformer is connected to the third AC output terminal; the second end of the primary winding of the third transformer, the second end of the primary winding of the second transformer, and the second end of the primary winding of the first transformer are connected in a star configuration. The first secondary winding assembly is connected to the secondary winding and DC output of the first transformer, respectively. The second secondary winding assembly is connected in parallel with the first secondary winding assembly; the second secondary winding assembly is connected to the secondary winding of the second transformer and the DC output respectively; as well as The third secondary winding assembly is connected in parallel with the first and second secondary winding assemblies; the third secondary winding assembly is connected to the secondary winding of the third transformer and the DC output, respectively. The operating timing of the first primary edge component, the second primary edge component, and the third primary edge component is out of phase.

2. The three-phase coupled interleaved DC-DC circuit of claim 1, wherein, The operating timing of the first primary edge component, the second primary edge component, and the third primary edge component is staggered by 120 degrees.

3. The three-phase coupled interleaved DC-DC circuit of claim 1, wherein, The first primary edge component, the second primary edge component, and / or the third primary edge component include: A first switch; the first terminal of the first switch is connected to the positive terminal of the DC input; A second switch; the first terminal of the second switch is connected to the negative terminal of the DC input, and the second terminal of the second switch is connected to the second terminal of the first switch; and Inductor; the first end of the inductor is connected between the second end of the first switch and the second end of the second switch, and the second end of the inductor is the AC output terminal of the primary side component.

4. The three-phase coupled interleaved DC-DC circuit of claim 1, wherein, The first primary edge component, the second primary edge component, and / or the third primary edge component include: A first switch; the first terminal of the first switch is connected to the positive terminal of the DC input; A second switch; the first end of the second switch is connected to the second end of the first switch; A third switch; the first end of the third switch is connected to the second end of the second switch; Inductor; the first end of the inductor is connected between the second end of the second switch and the first end of the third switch, and the second end of the inductor is the AC output terminal of the primary side component; a fourth switch, a first end of the fourth switch being connected to a second end of the third switch, a second end of the fourth switch being connected to a negative pole of the direct current input; and a capacitor, a first end of the capacitor being connected between a second end of the first switch and a first end of the second switch, a second end of the capacitor being connected between a second end of the third switch and a first end of the fourth switch.

5. The three-phase coupled interleaved DC-DC circuit of claim 1, wherein, the first primary assembly, the second primary assembly, and / or the third primary assembly comprise: a first switch, a first end of the first switch being connected to a positive pole of the direct current input; a second switch, a first end of the second switch being connected to a second end of the first switch; a third switch, a first end of the third switch being connected to a second end of the second switch; an inductor, a first end of the inductor being connected between a second end of the second switch and a first end of the third switch, a second end of the inductor being an alternating current output end of a primary assembly; a fourth switch, a first end of the fourth switch being connected to a second end of the third switch, a second end of the fourth switch being connected to a negative pole of the direct current input; a first capacitor, a first end of the first capacitor being connected between the positive pole of the direct current input and a first end of the first switch; a second capacitor, a first end of the second capacitor being connected to a second end of the first capacitor, a second end of the second capacitor being connected to a negative pole of the direct current input; a first diode, a cathode of the first diode being connected between the second end of the first switch and the first end of the second switch, an anode of the first diode being connected between the second end of the first capacitor and the first end of the second capacitor; and a second diode, a cathode of the second diode being connected between the second end of the first capacitor and the first end of the second capacitor, an anode of the second diode being connected between a second end of the third switch and a first end of the fourth switch.

6. The three-phase coupled interleaved DC-DC circuit according to claim 1 or 3, characterized in that, a first end and a second end of the first secondary assembly are connected to a first end and a second end of a secondary winding of the first transformer respectively, a third end and a fourth end of the first secondary assembly are connected to a positive pole and a negative pole of the direct current output respectively; a first end and a second end of the second secondary assembly are connected to a first end and a second end of a secondary winding of the second transformer respectively, a third end and a fourth end of the second secondary assembly are connected to a positive pole and a negative pole of the direct current output respectively; a first end and a second end of the third secondary assembly are connected to a first end and a second end of a secondary winding of the third transformer respectively, a third end and a fourth end of the third secondary assembly are connected to a positive pole and a negative pole of the direct current output respectively; the first secondary assembly, the second secondary assembly, and / or the third secondary assembly are identical full-bridge rectifier circuits.

7. The three-phase coupled interleaved DC-DC circuit of claim 6, wherein, the full-bridge rectifier circuit comprises: a first secondary switch, a first end of the first secondary switch being connected to a positive pole of the direct current output; a second secondary switch, a first end of the second secondary switch being connected to a second end of the first secondary switch, a second end of the second secondary switch being connected to a negative pole of the direct current output; a third auxiliary switch, a first end of the third auxiliary switch being connected to a second end of the second auxiliary switch and a negative pole of the DC output, and a fourth auxiliary switch, a first end of the fourth auxiliary switch being connected to a second end of the third auxiliary switch, and a second end of the fourth auxiliary switch being connected to a first end of the first auxiliary switch and a positive pole of the DC output; wherein a first end of an auxiliary winding of the transformer is connected between a second end of the third auxiliary switch and a first end of the fourth auxiliary switch, and a second end of the first auxiliary switch and a first end of the second auxiliary switch are connected to a second end of the auxiliary winding of the transformer.

8. The three-phase coupled interleaved DC-DC circuit of claim 7, wherein, The first auxiliary switch, the second auxiliary switch, the third auxiliary switch, and the fourth auxiliary switch are all the same transistor.

9. The three-phase coupled interleaved DC-DC circuit of claim 1, wherein, Further comprising: a first capacitor connected between a first end of the primary winding of the first transformer and the first AC output end; and / or a second capacitor connected between a first end of the primary winding of the second transformer and the second AC output end; and / or a third capacitor connected between a first end of the primary winding of the third transformer and the third AC output end.

10. A three-phase coupled interleaved DC-DC converter, characterized in that, A three-phase coupled interleaved DC-DC circuit according to any one of claims 1-9, a DC input and a DC output, the DC input and the DC output being connected to the three-phase coupled interleaved DC-DC circuit.

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