Wide-gain direct-current converter and control method thereof

Abstract

The invention relates to the technical field of converters, and discloses a wide-gain direct-current converter with a soft switching characteristic, which comprises a voltage reduction module, a voltage transformation module and a voltage boosting module, the voltage reduction module is used for receiving a driving signal input by a main controller, and the voltage transformation module is used for receiving an electric signal generated by on-off control of the voltage reduction module; the boosting module is connected with the secondary winding of the voltage transformation module through the voltage input and output end of the boosting module, and the driving signal is used for adjusting the phase difference between the voltage reduction module and the boosting module so as to change the energy output size and the energy transmission direction.

Description

Technical Field

[0001] The present invention relates to the technical field of converters, and more particularly, to a wide-gain DC converter and its control method. Background Art

[0002] In a four-switch Buck-Boost circuit, there are two half-bridge circuits. The front side is the Buck bridge arm, and the rear side is the Boost bridge arm. During the operation of the circuit, the discharge currents of the switching junction capacitances of the lower side of the Buck bridge arm and the upper side of the Boost bridge arm are in the same direction as the power transmission direction, and soft switching can be automatically achieved. However, the discharge directions of the switching junction capacitances of the upper side of the Buck bridge arm and the lower side of the Boost bridge arm are opposite to the power transmission direction, so it is extremely difficult to achieve soft switching.

[0003] Therefore, how to achieve full-range soft switching of the Boost bridge arm in a four-switch Buck-Boost circuit has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a wide-gain DC converter and its control method that can achieve soft switching, aiming at the problem that the discharge directions of the switching junction capacitances of the upper side of the Buck bridge arm and the lower side of the Boost bridge arm in the prior art are opposite to the power transmission direction, resulting in difficulty in achieving soft switching.

[0005] The technical solution adopted by the present invention to solve its technical problems is to construct a wide-gain DC converter, comprising:

[0006] A buck module, whose signal input terminals are respectively used to receive the drive signals input by the main controller, and the drive signals are used to control its on / off state;

[0007] A transformer module, whose primary windings are respectively connected to the voltage input / output terminals of the buck module, and is used to receive the electrical signals formed when the buck module is controlled to be on / off;

[0008] A boost module, whose signal input terminals are respectively used to receive the drive signals input by the main controller, and the drive signals control its on / off state;

[0009] The voltage input / output terminals of the boost module are respectively connected to the secondary windings of the transformer module, and the drive signals are used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

[0010] In some embodiments, the buck module includes a first bridge arm and a second bridge arm connected in parallel,

[0011] The signal input terminals of the first bridge arm and the second bridge arm respectively receive the drive signals,

[0012] The drive signal is used to control the on / off states of the first arm and the second arm.

[0013] One end of the first arm is connected to one end of the primary winding of the transformer module.

[0014] One end of the second arm is connected to the other end of the primary winding of the transformer module.

[0015] In some embodiments, when the converter operates in the Boost mode, the first arm and the second arm are in the always-on state.

[0016] In some embodiments, it further includes a bus capacitor, and the bus capacitor is connected in parallel with the first arm and the second arm.

[0017] In some embodiments, the first arm includes a first MOS transistor and a second MOS transistor connected in series.

[0018] The second arm includes a third MOS transistor and a fourth MOS transistor connected in series.

[0019] The gates of the first MOS transistor, the second MOS transistor, the third MOS transistor, and the fourth MOS transistor respectively receive the drive signal.

[0020] The sources of the first MOS transistor and the third MOS transistor are respectively connected to one end of the primary winding of the transformer module.

[0021] The drains of the first MOS transistor and the third MOS transistor are respectively connected to one end of the bus capacitor.

[0022] The sources of the second MOS transistor and the fourth MOS transistor are respectively connected to the other end of the bus capacitor.

[0023] In some embodiments, it further includes a first inductor and a third inductor connected in series.

[0024] The connection ends of the first inductor and the third inductor are respectively connected to the source of the first MOS transistor and the drain of the second MOS transistor.

[0025] The other end of the first inductor is connected to one end of the input capacitor, and the other end of the third inductor is coupled to one end of the primary winding of the transformer module.

[0026] In some embodiments, the boost module includes a third arm and a fourth arm connected in parallel.

[0027] The signal input terminals of the third bridge arm and the second bridge arm respectively receive the drive signal,

[0028] The drive signal is used to control the on / off states of the third bridge arm and the fourth bridge arm,

[0029] One end of the third bridge arm is connected to one end of the secondary winding of the transformer module,

[0030] One end of the fourth bridge arm is connected to the other end of the secondary winding of the transformer module.

[0031] In some embodiments, when the converter operates in the Buck mode, the third bridge arm and the fourth bridge arm are in the always-on state.

[0032] In some embodiments, the third bridge arm includes a fifth MOS transistor and a seventh MOS transistor connected in series,

[0033] The fourth bridge arm includes a sixth MOS transistor and an eighth MOS transistor connected in series,

[0034] The gates of the fifth MOS transistor and the sixth MOS transistor respectively receive the drive signal, and the gates of the seventh MOS transistor and the eighth MOS transistor also respectively receive the drive signal;

[0035] The sources of the fifth MOS transistor and the eighth MOS transistor are both connected to one end of the secondary winding of the transformer module.

[0036] The drain of the fifth MOS transistor and the drain of the sixth MOS transistor are respectively connected to one end of the output capacitor,

[0037] The sources of the seventh MOS transistor and the eighth MOS transistor are commonly connected to the other end of the output capacitor.

[0038] Second aspect, a control method for a wide-gain DC converter, applied to any of the above-mentioned wide-gain DC converters, includes:

[0039] S101, mode selection;

[0040] S102, controlling the on / off state of the buck module by adjusting the duty cycle of the drive signal;

[0041] S103, the transformer module is used to receive the electrical signal output when the buck module is controlled to be on / off;

[0042] S104, controlling the on / off state of the boost module by adjusting the duty cycle of the drive signal, and the drive signal is used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

[0043] In the wide-gain DC converter of the present invention, it includes a buck module, a transformer module, and a boost module for receiving the drive signal input by the master controller. Among them, the transformer module receives the electrical signal generated by the on-off control of the buck module, and the boost module is connected to the secondary winding of the transformer module through its voltage input and output terminals. The drive signal is used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction. Compared with the prior art, through the bridge arm multiplexing strategy, the traditional four-switch Buck-Boost topology is combined with the dual-active bridge circuit, effectively combining the advantages of the two circuit topologies. This circuit not only solves the problem that it is difficult for the four-switch Buck-Boost to achieve soft switching, but also overcomes the defect of the limited gain range of the dual-active bridge circuit. In addition, the quadrilateral inductor current modulation technology is applied, greatly broadening the soft-switching operating range of the converter and effectively improving the overall operating efficiency of the converter. Brief Description of the Drawings

[0044] The following will further illustrate the present invention in conjunction with the drawings and embodiments. In the drawings:

[0045] Figure 1 is the circuit topology diagram of an embodiment of the wide-gain DC converter provided by the present invention;

[0046] Figure 2 is the equivalent circuit diagram of the Boost mode of an embodiment of the wide-gain DC converter provided by the present invention;

[0047] Figure 3 is the control timing diagram of the Boost operating mode provided by the present invention;

[0048] Figure 4 is the modal diagram provided by the present invention;

[0049] Figure 5 is the control timing diagram of the quadrilateral inductor current modulation technology provided by the present invention;

[0050] Figure 6 is the working modal diagram of the four-switch Buck-Boost provided by the present invention;

[0051] Figure 7 is the control timing diagram of the Buck-Boost operating mode provided by the present invention. Detailed Embodiment

[0052] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described in detail with reference to the drawings.

[0053] As Figure 1 - Figure 7As shown, in the first embodiment of the wide-gain DC converter of the present invention, the wide-gain DC converter at least includes a buck module, a transformer module T, and a boost module.

[0054] The buck module is responsible for converting the input voltage into a lower output voltage.

[0055] The transformer module T has functions of boosting, bucking, and isolation.

[0056] The boost module adjusts the input voltage to the required output by controlling the on / off of the switching transistor. When the switching transistor is on, the inductor is charged; when it is off, the inductor discharges to the load through the diode to achieve voltage boost.

[0057] Specifically, the signal input terminals of the buck module are respectively used to receive multiple drive signals input by a main controller (not shown), and the input drive signals are used to control the on / off state of the buck module.

[0058] For example, when the input voltage Vin is greater than the output voltage Vo, the four-switch buck-boost converter operates in the Buck mode. At this time, the duty cycle of the main control switch transistor of the Boost unit is set to 0, and the output voltage Vo is maintained stable by only controlling the duty cycle of the main control switch transistor of the Buck unit, that is, one switching transistor is always off and the other is always on, and the two switching transistors do not turn on each other according to the value of the duty cycle.

[0059] In addition, the primary winding of the transformer module T is connected to the voltage input / output terminals of the buck module, responsible for receiving the electrical signals generated during the on / off control process of the buck module, and coupling and transmitting these signals to the boost module.

[0060] The signal input terminals of the boost module are respectively used to receive multiple drive signals input by a main controller (not shown), and the input drive signals are used to control the on / off state of the boost module.

[0061] For example, when the input voltage Vin is less than or equal to the output voltage Vo, the four-switch buck-boost converter operates in the Boost mode. At this time, the duty cycle of the main control switch transistor of the Buck unit is set to 1, and the output voltage Vo is maintained stable by controlling the duty cycle of the main control switch transistor of the Boost unit, that is, one switching transistor is always on and the other is always off, and the two switching transistors do not turn on each other according to the value of the duty cycle.

[0062] Among them, the voltage input / output terminals of the boost module are respectively connected to the secondary winding of the transformer module T, and the drive signal is used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

[0063] Using this technical solution, through the bridge arm multiplexing strategy, the traditional four-switch Buck-Boost topology is combined with the dual active bridge circuit, effectively combining the advantages of the two circuit topologies. The circuit not only improves the drawback of the four-switch Buck-Boost being difficult to achieve soft switching, but also improves the shortcoming of the dual active bridge circuit being difficult to achieve a wide gain range. Additionally, the quadrilateral inductor current modulation technology is applied, greatly broadening the soft switching operating range of the converter and effectively improving the overall operating efficiency of the converter.

[0064] In some embodiments, the buck module includes a first bridge arm and a second bridge arm connected in parallel, where

[0065] The signal input ends of the first bridge arm and the second bridge arm respectively receive multiple drive signals input by a main controller (not shown),

[0066] The main function of these multiple drive signals is to precisely control the on / off states of the first bridge arm and the second bridge arm,

[0067] One end of the first bridge arm is connected to one end (corresponding to a) of the primary winding of the transformer module T,

[0068] One end of the second bridge arm is connected to the other end (corresponding to b) of the primary winding of the transformer module T.

[0069] In some embodiments, in the Boost operating mode, the first bridge arm and the second bridge arm will remain in a continuously conducting state.

[0070] In some embodiments, in order to improve the matching accuracy of the output voltage, a bus capacitor Cbus can be added to the converter, and this capacitor is connected in parallel with the first bridge arm and the second bridge arm.

[0071] In some embodiments, in order to ensure the reliability of bucking, a first MOS transistor S 2a and a second MOS transistor S2 connected in series can be provided in the first bridge arm,

[0072] The second bridge arm includes a third MOS transistor S 4a and a fourth MOS transistor S4 connected in series,

[0073] Wherein, the gate of the first MOS transistor S 2a , the gate of the second MOS transistor S2, the gate of the third MOS transistor S 4a , and the gate of the fourth MOS transistor S4 respectively receive multiple drive signals input by a main controller (not shown),

[0074] The source of the first MOS transistor S 2a and the source of the third MOS transistor S 4a are respectively connected to one end of the primary winding of the transformer module T,

[0075] The drain of the first MOS transistor S 2a and the drain of the third MOS transistor S 4a are respectively connected to one end of the bus capacitor C bus .

[0076] The source of the second MOS transistor S2 and the source of the fourth MOS transistor S4 are respectively connected to the other end of the bus capacitor C bus .

[0077] In some embodiments, it further includes a first inductor L1 and a third inductor Lr connected in series,

[0078] The connection terminals of the first inductor L1 and the third inductor Lr are respectively connected to the source of the first MOS transistor S 2a and the drain of the second MOS transistor,

[0079] The other end of the first inductor L1 is connected to one end of the input capacitor,

[0080] The other end of the third inductor Lr is coupled to one end of the primary winding of the transformer module T.

[0081] In some embodiments, the boost module includes a third bridge arm and a fourth bridge arm connected in parallel,

[0082] wherein, the signal input terminals of the third bridge arm and the second bridge arm respectively receive a plurality of drive signals input by a main controller (not shown),

[0083] The drive signals are used to control the on / off states of the third bridge arm and the fourth bridge arm,

[0084] One end of the third bridge arm is connected to one end of the secondary winding of the transformer module T (corresponding to c),

[0085] One end of the fourth bridge arm is connected to the other end of the secondary winding of the transformer module T (corresponding to d).

[0086] In some embodiments, when the converter is in the Buck operating mode, the third bridge arm and the fourth bridge arm remain in the always-on state.

[0087] In some embodiments, as Figure 2 shown, in order to ensure the reliability of boosting, a fifth MOS transistor S5 and a seventh MOS transistor S7 connected in series can be provided in the third bridge arm,

[0088] The fourth bridge arm includes a sixth MOS transistor S6 and an eighth MOS transistor S8 connected in series,

[0089] The gates of the fifth MOS transistor S5 and the sixth MOS transistor S6, the gates of the seventh MOS transistor S7 and the eighth MOS transistor S8 respectively receive drive signals,

[0090] The source electrodes of the fifth MOS transistor S5 and the eighth MOS transistor S8 are respectively connected to one end of the secondary winding of the transformer module T.

[0091] The drain electrodes of the fifth MOS transistor S5 and the sixth MOS transistor S6 are respectively connected to one end of the output capacitor Co.

[0092] The source electrodes of the seventh MOS transistor S7 and the eighth MOS transistor S8 are respectively connected to the other end of the output capacitor Co.

[0093] As Figure 2 shown, in the buck mode, the fifth MOS transistor S5 and the sixth MOS transistor S6 are constantly conducting, the seventh MOS transistor S7 and the eighth MOS transistor S8 are constantly non-conducting, and the first MOS transistor S 2a and the fourth MOS transistor S4 or the second MOS transistor S2 and the third MOS transistor S 4a conduct with complementary duty cycles;

[0094] In the buck-boost mode, the fifth MOS transistor S5 and the eighth MOS transistor S8 or the sixth MOS transistor S6 and the seventh MOS transistor S7, the first MOS transistor S 2a and the fourth MOS transistor S4 or the second MOS transistor S2 and the third MOS transistor S 4a conduct with complementary duty cycles;

[0095] In the boost mode, the first MOS transistor S 2a or the third MOS transistor S 4a is constantly conducting, the second MOS transistor S2 or the fourth MOS transistor S4 is constantly non-conducting, and the fifth MOS transistor S5 and the seventh MOS transistor S7 or the sixth MOS transistor S6 and the eighth MOS transistor S8 conduct with complementary duty cycles;

[0096] When the inverter switches from the buck mode to the buck-boost mode, or from the boost mode to the buck-boost mode, both the output voltage and current can smoothly transition;

[0097] Specifically, as Figure 1 shown, when the circuit is in the Boost operating mode, the Buck bridge arm in the front-stage four-switch Buck-Boost circuit remains constantly conducting, and the gain is fixed at 1. At this time, if the duty cycles of the MOS transistors S3 and S4 are set to d2, and the transformer turns ratio is N, then the total gain of the entire circuit can be expressed as

[0098]

[0099] As Figure 2As shown, the control scheme of this circuit combines PWM (Pulse Width Modulation) and phase shift (PWM Plus Phase Shift, PPS) technologies. By adjusting the duty cycle d2 of MOS transistors S2 and S4, the matching between the bus capacitor C bus and the output voltage is achieved. Further, by adjusting the phase difference φ among MOS transistors S4, S5, and S8, the magnitude and transfer direction of the output energy can be controlled.

[0100] As Figure 3 shown, the control timing diagram of the circuit and the final modal diagram of the circuit are as Figure 4 shown

[0101] Mode 0 [0, t0]: As Figure 4 shown in (a), MOS transistors S2 and MOS transistor S 4a turn on,

[0102] i Lr = -I0

[0103] Mode 1 [t0, t1]: As Figure 4 shown in (b), at time t0, MOS transistor S 4a turns off, and the body capacitors of MOS transistor S 4a and MOS transistor S4 resonate, and MOS transistor S4 achieves ZVS;

[0104]

[0105] Mode 2 [t1, t2]: As Figure 4 (c) shown, at time t1, MOS transistor S2 turns off, and the body capacitor of MOS transistor S 2a resonates with the body capacitor of MOS transistor S2, and MOS transistor S 2a achieves ZVS;

[0106]

[0107] Mode 3 [t2, t3]: As Figure 4 (d) shown, at time t2, MOS transistors S6 and S7 turn off, and then their body capacitors resonate with the body capacitors of MOS transistors S5 and S8, enabling MOS transistors S5 and S8 to achieve zero voltage switching (ZVS).

[0108] i Lr = -I0

[0109] Mode 4 [t3, t4]: As Figure 4 (e) shown, at time t3, MOS transistor S 2a turns off, and MOS transistor S 2a resonates with MOS transistor S 4aThe body capacitance resonates, and the MOS transistor S2 achieves ZVS;

[0110]

[0111] Mode 5 [t4, t5]: As Figure 4 (f) shows that at time t4, the MOS transistor S4 turns off, and the MOS transistor S 4a resonates with the body capacitance of the MOS transistor S4, and the MOS transistor S 4a achieves ZVS;

[0112]

[0113]

[0114] Mode 6 [t5, t6]: As Figure 4 (g) shows, but note that here it should be at time t5, the MOS transistors S5 and S8 turn off, and their body capacitances then resonate with the body capacitances of the MOS transistors S6 and S7, resulting in the MOS transistors S6 and S7 achieving zero-voltage switching (ZVS);

[0115] By adjusting the phase difference φ2 and the duty cycle d2 of the MOS transistors S4, S5, and S8, the direction and magnitude of the energy transfer in the circuit can be controlled. The relationship between the output power P and the phase difference φ2 and the duty cycle d2 can be expressed by the following formula: P = f(φ2, d2), where f represents a specific functional relationship.

[0116]

[0117] Since d2 participates in and determines the magnitude of the final output power, the maximum output power under a fixed d2 can be obtained, which is the maximum output power limit of the circuit

[0118]

[0119] Buck - Boost operating mode

[0120] During the circuit operating cycle, there is no mutual influence on the gain between the four-switch Buck - Boost and the dual-active-bridge circuit. Therefore, in terms of gain, it can be regarded as the cascade of the four-switch Buck - Boost and the dual-active-bridge circuit. Refer to Figure 1 , in the four-switch Buck - Boost converter, if the duty cycle of the MOS transistor S1 is d1, the duty cycle of the MOS transistor S4 is d2, and the transformer turns ratio is N, then the total gain G can be expressed as G = N * (d1 / (1 - d2));

[0121]

[0122] Adopt the PWM plus phase shift (PPS) control scheme. By adjusting the duty cycles d1 and d2 of MOS transistors S3 and S4, the matching between the bus capacitor C bus and the output voltage is achieved;

[0123] Modulate the inductor current by adjusting the phase angle φ1 and the duty cycles d1 and d2. Adjusting the phase difference φ2 among MOS transistors S4, S5, and S8 can change the energy output and transfer direction;

[0124] The control timing of the circuit is relatively complex. Therefore, the circuit is divided into two levels for analysis. For the front-stage four-switch Buck-Boost, the quadrilateral inductor current modulation technology is adopted;

[0125] Figure 5 The control timing diagram is shown as follows, Figure 6 which is the four working mode diagrams of the four-switch Buck-Boost:

[0126] By changing and the duty cycles d1 and d2, the working time of the four working modes can be changed, thereby achieving the modulation of the inductor current;

[0127] Mode 1 [t0, t1]: As Figure 6 (a) shows, at time t0, MOS transistor S3 is turned off. With the help of the reverse inductor current, MOS transistor S1 achieves ZVS. After that, MOS transistors S1 and S4 remain on

[0128] v L = V in

[0129]

[0130] Mode 2 [t1, t2]: As Figure 6 (b) shows, at time t1, MOS transistor S4 is turned off. Subsequently, MOS transistor S2 achieves zero-voltage switching (ZVS). After that, MOS transistors S1 and S2 remain on

[0131] v L = V in - V o

[0132]

[0133] Mode 3 [t2, t3]: As Figure 6 (c) shows, at time t2, MOS transistor S1 is turned off. Then, MOS transistor S3 achieves zero-voltage switching (ZVS). After that, MOS transistors S3 and S2 remain on

[0134] v L = - V o

[0135]

[0136] Mode 4 [t3, t4]: As Figure 6 (d) shows that at time t3, MOS transistor S2 is turned off. Finally, MOS transistor S4 achieves zero-voltage switching (ZVS), and then MOS transistors S3 and S4 remain on.

[0137] v L = 0

[0138]

[0139] For the subsequent dual-active-bridge circuit, its control timing is as Figure 3 shown, and the circuit mode diagram is as Figure 4 shown. Therefore, combining the control timings of the front and rear stages gives the control timing diagram of the Buck-Boost operating mode, as Figure 7 shown;

[0140] For the quadrilateral inductor current modulation, referring to Figure 6 , the operating times of its direct power transfer modes 2 and 3 are limited, and as the soft-switching difficulty increases, the operating time is further reduced. Therefore, there is a maximum input power limit (V b refers to the bus capacitor voltage);

[0141]

[0142] For the overall circuit, by adjusting the phase difference between MOS transistors S1, S5, and S8 to change the energy transfer direction and magnitude, the relationship between the output power P with respect to and the duty cycle d2 can be obtained as

[0143]

[0144] Since d2 participates in and determines the final output power magnitude, the maximum output power under a fixed d2 can be obtained, which is the maximum output power limit of the circuit

[0145]

[0146] Considering that there are power upper limits on both the input and output sides of the circuit, therefore, the final output power of the circuit will be affected by these limitations.

[0147] P ≤ max{P Omax , P Imax}

[0148] Second aspect, a control method for a wide-gain DC converter, which is applied to any of the above wide-gain DC converters, includes:

[0149] S101. Mode selection;

[0150] S102. Control the on / off state of the buck module by adjusting the duty cycle of the drive signal;

[0151] S103. The transformer module T is used to receive the electrical signal output when the buck module is controlled to be on / off;

[0152] S104. Control the on / off state of the boost module by adjusting the duty cycle of the drive signal. The drive signal is used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

[0153] In this technical solution, through the bridge arm multiplexing strategy, the traditional four-switch Buck-Boost topology is combined with the dual-active bridge circuit, and the advantages of the two circuit topologies are effectively combined. The circuit not only improves the drawback that it is difficult to achieve soft switching in the four-switch Buck-Boost, but also improves the disadvantage that it is difficult to achieve a wide gain range in the dual-active bridge circuit. This application also applies the quadrilateral inductor current modulation technology, which greatly broadens the soft-switching operating range of the converter and can effectively improve the overall operating efficiency of the converter.

[0154] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims. All of these fall within the protection scope of the present invention.

Claims

1. A wide-gain DC converter, characterized in that, Comprising: A buck module, whose signal input terminals are respectively used to receive the drive signals input by the main controller, and the drive signals are used to control its on / off state; A transformer module, whose primary windings are respectively connected to the voltage input / output terminals of the buck module, and are used to receive the electrical signals formed when the buck module is controlled to be on / off; A boost module, whose signal input terminals are respectively used to receive the drive signals input by the main controller, and the drive signals control its on / off state; The voltage input / output terminals of the boost module are respectively connected to the secondary windings of the transformer module, and the drive signals are used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

2. The wide-gain DC converter according to claim 1, wherein The buck module includes a first bridge arm and a second bridge arm connected in parallel, The signal input terminals of the first bridge arm and the second bridge arm respectively receive the drive signals, The drive signals are used to control the on / off states of the first bridge arm and the second bridge arm, One end of the first bridge arm is connected to one end of the primary winding of the transformer module, One end of the second bridge arm is connected to the other end of the primary winding of the transformer module.

3. The wide-gain DC converter according to claim 2, wherein When the converter is in the Boost operating mode, the first bridge arm and the second bridge arm remain in the always-on state.

4. The wide-gain DC converter according to claim 2 or 3, characterized in that, It further includes a bus capacitor, and the bus capacitor is arranged in parallel with the first bridge arm and the second bridge arm.

5. The wide-gain DC converter according to claim 4, wherein The first bridge arm includes a first MOS transistor and a second MOS transistor connected in series, The second bridge arm includes a third MOS transistor and a fourth MOS transistor connected in series, The gates of the first MOS transistor, the second MOS transistor, the third MOS transistor, and the fourth MOS transistor respectively receive the drive signals, The sources of the first MOS transistor and the third MOS transistor are respectively connected to one end of the primary winding of the transformer module, The drains of the first MOS transistor and the third MOS transistor are respectively connected to one end of the bus capacitor, The sources of the second MOS transistor and the fourth MOS transistor are respectively connected to the other end of the bus capacitor.

6. The wide-gain DC converter according to claim 5, wherein It further includes a first inductor and a third inductor connected in series, The connection terminals of the first inductor and the third inductor are respectively connected to the source of the first MOS transistor and the drain of the second MOS transistor, The other end of the first inductor is connected to one end of the input capacitor, The other end of the third inductor is coupled to one end of the primary winding of the transformer module.

7. The wide-gain DC converter according to claim 1, wherein The boost module includes a third bridge arm and a fourth bridge arm connected in parallel, The signal input terminals of the third bridge arm and the second bridge arm respectively receive the drive signals, The drive signals are used to control the on / off states of the third bridge arm and the fourth bridge arm, One end of the third bridge arm is connected to one end of the secondary winding of the transformer module. One end of the fourth bridge arm is connected to the other end of the secondary winding of the transformer module.

8. The wide-gain DC converter according to claim 7, wherein when the converter operates in the Buck mode, the third bridge arm and the fourth bridge arm are in a constantly-conducting state.

9. The wide-gain DC converter according to claim 8, wherein the third bridge arm includes a fifth MOS transistor and a seventh MOS transistor connected in series, the fourth bridge arm includes a sixth MOS transistor and an eighth MOS transistor connected in series, the gates of the fifth MOS transistor and the sixth MOS transistor respectively receive drive signals, and the gates of the seventh MOS transistor and the eighth MOS transistor also respectively receive drive signals; the sources of the fifth MOS transistor and the eighth MOS transistor are both connected to one end of the secondary winding of the transformer module. The drain of the fifth MOS transistor and the drain of the sixth MOS transistor are respectively connected to one end of the output capacitor, the sources of the seventh MOS transistor and the eighth MOS transistor are commonly connected to the other end of the output capacitor.

10. A control method for a wide-gain DC converter, applied to the wide-gain DC converter according to any one of claims 1-9, characterized in that, including: S101, mode selection; S102, controlling the on / off state of the buck module by adjusting the duty ratio of the drive signal; S103, the transformer module is configured to receive the electrical signal output when the buck module is controlled to be on / off; S104, controlling the on / off state of the boost module by adjusting the duty ratio of the drive signal, and the drive signal is used to adjust the phase difference between the buck module and the boost module to change the energy output magnitude and the energy transfer direction.

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