A power converter

Abstract

The present invention discloses a power converter, which dynamically adjusts the current waveform by adjusting the duty cycle of the switching tube in the power correction circuit, compensates for the phase difference between the current and voltage signals, and outputs a constant DC voltage with small ripple. This compensates for the problem of reduced power conversion efficiency caused by the switching frequency deviating from the resonant frequency point when the input voltage or load changes too much. The converter can also be adjusted at any time according to the control signal output by the feedback circuit, thereby improving the quality of power conversion and being widely applicable to various electronic products.

Description

Technical Field

[0001] The present invention belongs to the field of direct current power conversion, and in particular relates to a power converter. Background Art

[0002] Under existing technical conditions, switching power supplies are widely used due to their good performance. Unlike linear power supplies, switching power supplies switch between fully on or fully off states, thereby minimizing wasted energy. However, when the input voltage or load of the half-bridge LLC in the switching power supply changes significantly, the switching frequency will deviate from the resonant frequency range, resulting in reduced efficiency, which restricts its use in application scenarios with a wide output voltage range or large load changes. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and provides a power converter.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] In an embodiment of the present invention, a power converter includes:

[0006] A power correction circuit, a half-bridge circuit, a resonant circuit, a transformer, and an output rectifier circuit connected in sequence;

[0007] The feedback circuit is connected to the output end of the output rectifier circuit, the feedback circuit is connected to the drive circuit, and the drive circuit is connected to the half-bridge circuit;

[0008] The power correction circuit is used to perform power factor correction on the external input voltage and then output a first DC voltage to the half-bridge circuit;

[0009] The half-bridge circuit is used to receive the first DC voltage output by the power correction circuit and output a pulse voltage to the resonant circuit;

[0010] The resonant circuit is used to receive the pulse voltage output by the half-bridge circuit and output a first AC voltage to the transformer;

[0011] The transformer is used to receive the first AC voltage output by the resonant circuit and output a second AC voltage to the output rectifier circuit;

[0012] The output rectifier circuit is used to receive the second AC voltage output by the transformer and output a second DC voltage;

[0013] The feedback circuit is used to output a control signal to the driving circuit according to the second DC voltage;

[0014] The driving circuit is used to adjust the pulse voltage output by the half-bridge circuit according to the control signal.

[0015] In one embodiment of the present invention, the feedback circuit is connected to the voltage sampling circuit, and the voltage sampling circuit is connected to the output end of the output rectifier circuit. The voltage sampling circuit is used to collect the second DC voltage output by the output rectifier circuit and send a corresponding signal to the feedback circuit.

[0016] In one embodiment of the present invention, the auxiliary power supply side of the transformer is connected to the auxiliary power supply circuit, the auxiliary power supply circuit is connected to the drive circuit, and the auxiliary power supply circuit is used to supply power to the drive circuit.

[0017] In one embodiment of the present invention, a power correction circuit includes: a first input filter circuit, an energy storage inductor, a first switching tube, a Schottky diode and a first output filter circuit; one end of the energy storage inductor is connected to the external input voltage and the first input filter circuit, and the other end is connected to the drain of the first switching tube and the positive electrode of the Schottky diode, and the negative electrode of the Schottky diode is connected to the first output filter circuit and the input end of the half-bridge circuit.

[0018] In one embodiment of the present invention, the half-bridge circuit includes: a second switching tube and a third switching tube; the drain of the second switching tube is connected to the negative electrode of the Schottky diode and the first output filter circuit, and the source of the second switching tube is connected to the drain of the third switching tube and the input end of the resonant circuit.

[0019] In one embodiment of the present invention, the output rectifier circuit includes: a fourth switching tube, a fifth switching tube, and a second output filter circuit; the drain of the fourth switching tube and the drain of the fifth switching tube are respectively connected to the first secondary side and the second secondary side of the transformer, and the source of the fourth switching tube and the source of the fifth switching tube are both connected to the negative electrode of the second output filter circuit and the secondary ground; the positive electrode of the second output filter circuit is connected to the first secondary side of the transformer and the voltage sampling circuit.

[0020] In one embodiment of the present invention, the feedback circuit includes: a subtractor, a voltage-frequency oscillator and a gate logic driver; the negative input terminal of the subtractor is connected to the voltage sampling circuit, the positive input terminal is connected to the reference frequency value, and the output terminal is connected to the input terminal of the voltage-frequency oscillator; the output terminal of the voltage-frequency oscillator is connected to the input terminal of the gate logic driver, and the output terminal of the gate logic driver is connected to the drive circuit.

[0021] In one embodiment of the present invention, the first switch is an N-channel silicon carbide field effect transistor.

[0022] In one embodiment of the present invention, the second switch tube and the third switch tube are both N-channel silicon carbide field effect transistors.

[0023] In one embodiment of the present invention, the fourth switch tube and the fifth switch tube are both N-channel silicon carbide field effect transistors.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention discloses a power converter, which dynamically adjusts the current waveform by adjusting the duty cycle of the switching tube in the power correction circuit, compensates for the phase difference between the current and voltage signals, and outputs a constant DC voltage with small ripple. This compensates for the problem of reduced power conversion efficiency caused by the switching frequency deviating from the resonant frequency point when the input voltage or load changes too much. The converter can also be adjusted at any time according to the control signal output by the feedback circuit, thereby improving the quality of power conversion and being widely applicable to various electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] In the attached figure:

[0028] Figure 1 This is a schematic diagram of a power converter according to an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a power correction circuit for a power converter according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a rectifier output circuit of a power converter according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of a voltage sampling circuit for a power converter according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of a power converter feedback circuit according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of a power converter driving circuit according to an embodiment of the present invention;

[0034] Figure 7 The figure is a schematic diagram of an auxiliary power supply circuit of a power converter according to an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1-Power correction circuit; 11-First input filter circuit; 12-Energy storage inductor; 13-First switching tube; 14-Schottky diode; 15-First output filter circuit; 2-Half-bridge circuit; 21-Second switching tube; 22-Third switching tube; 3-Resonant circuit; 31-Resonant capacitor; 32-Resonant inductor; 33-Magnetic inductor; 4-Transformer; 41-Primary side; 42-First secondary side; 43-Second secondary side; 44-Auxiliary power supply side; 5-Output rectifier circuit; 51-Fourth switching tube; 52-Fifth switching tube; 53-Second output filter circuit; 6-Auxiliary power supply circuit; 61-Third output filter circuit; 62-Anti- Reverse diode; 63-clamping diode; 7-voltage sampling circuit; 71-III-order compensation circuit; 72-three-terminal adjustable voltage regulator; 73-optocoupler isolation; 731-light-emitting diode; 732-phototransistor; 8-feedback circuit; 81-subtractor; 82-voltage-frequency oscillator; 83-gate logic drive; 831-dead time generation circuit; 832-high-voltage level shift circuit; 833-low-voltage level shift circuit; 9-drive circuit; 91-bootstrap circuit; 911-bootstrap diode; 912-bootstrap capacitor; 92-independent pull-up and pour-down circuit; 921-turn-on resistor; 922-turn-off resistor; 931-low-dropout linear regulator. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0040] In the description of the present invention, it should be further clarified that the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0042] In one embodiment of the present invention, Figure 1 As shown, a power converter includes:

[0043] The power correction circuit 1, the half-bridge circuit 2, the resonant circuit 3, the transformer 4 and the output rectifier circuit 5 are connected in sequence;

[0044] In this embodiment, the power correction circuit 1 is represented as PFC;

[0045] The feedback circuit 8 is connected to the output end of the output rectifier circuit 5, the feedback circuit 8 is connected to the drive circuit 9, and the drive circuit 9 is connected to the half-bridge circuit 2;

[0046] The power correction circuit 1 is used to perform power factor correction on the external input voltage and output a first DC voltage to the half-bridge circuit 2;

[0047] The half-bridge circuit 2 is used to receive the first DC voltage output by the power correction circuit 1 and output a pulse voltage to the resonant circuit 3;

[0048] The resonant circuit 3 is used to receive the pulse voltage output by the half-bridge circuit 2 and output a first AC voltage to the transformer 4;

[0049] The transformer 4 is used to receive the first AC voltage output by the resonant circuit 3 and output a second AC voltage to the output rectifier circuit 5;

[0050] The output rectifier circuit 5 is used to receive the second AC voltage output by the transformer 4 and output a second DC voltage;

[0051] The feedback circuit 8 is used to output a control signal to the drive circuit 9 according to the second DC voltage;

[0052] The driving circuit 9 is used to adjust the pulse voltage output by the half-bridge circuit 2 according to the control signal.

[0053] On the basis of the above embodiment, in another embodiment of the present invention, as Figure 1As shown, the feedback circuit 8 is connected to the voltage sampling circuit 7, and the voltage sampling circuit 7 is connected to the output end of the output rectifier circuit 5. The voltage sampling circuit 7 is used to collect the second DC voltage output by the output rectifier circuit 5 and send a corresponding signal to the feedback circuit 8.

[0054] On the basis of the above embodiment, in another embodiment of the present invention, as Figure 1 As shown, the auxiliary power side 44 of the transformer 4 is connected to the auxiliary power circuit 6 , and the auxiliary power circuit 6 is connected to the drive circuit 9 . The auxiliary power circuit 6 is used to supply power to the drive circuit 9 .

[0055] In one embodiment of the present invention, Figure 1 and Figure 2 As shown, the power correction circuit 1 includes: a first input filter circuit 11, an energy storage inductor 12, a first switching tube 13, a Schottky diode 14 and a first output filter circuit 15; one end of the energy storage inductor 12 is connected to the external input voltage and the first input filter circuit 11, and the other end is connected to the drain of the first switching tube 13 and the positive electrode of the Schottky diode 14, and the negative electrode of the Schottky diode 14 is connected to the first output filter circuit 15 and the input end of the half-bridge circuit 2.

[0056] When the gate signal of first switch 13 is low, it is turned off, effectively disconnecting the circuit. Energy storage inductor 12 discharges, and the current flows through Schottky diode 14, superimposing with the input voltage to power half-bridge circuit 2. Power correction circuit 1 controls the on-time of the switch to align the input current with the input voltage, thereby improving the power factor. When the gate signal of first switch 13 is high, it is turned on, effectively short-circuiting the circuit. The input voltage charges energy storage inductor 12, while first input filter circuit 11 supplies power to half-bridge circuit 2.

[0057] According to the average current in the power correction circuit 1 , select Schottky diode 14 model, the following relationship exists:

[0058] ;

[0059] in, is the output power of the power correction circuit 1, is the output voltage of the power correction circuit 1;

[0060] Furthermore, the energy storage inductor 12 in the power correction circuit 1 has the functions of energy storage and discharge. The energy storage inductor 12 is represented as L , the selection range is as follows:

[0061] ;

[0062] in, Indicates the switching frequency of the gate control signal of the first switch tube 13 in the power correction circuit 1; 、 are the minimum and maximum input voltages of the power correction circuit 1; represents the input power of the power correction circuit 1;

[0063] Furthermore, the first output filter circuit 15 is represented as C min1 , the selection calculation is as follows:

[0064] ;

[0065] in, It is the holding time after the power correction circuit 1 disconnects the output voltage. It is represented as the overall expected efficiency of the power correction circuit 1, which is 96%.

[0066] In one embodiment of the present invention, Figure 1 and 2 As shown, the half-bridge circuit 2 includes: a second switch tube 21 and a third switch tube 22; the drain of the second switch tube 21 is connected to the cathode of the Schottky diode 14 and the first output filter circuit 15, and the source of the second switch tube 21 is connected to the drain of the third switch tube 22 and the input end of the resonant circuit 3. connect The source of the second switch 21 and the resonant circuit 3 are connected to the power ground, and the source of the third switch 22 is connected to the power ground. The gates of the second and third switches 21 and 22 are both connected to the drive circuit 9. The second and third switches 21 and 22 are alternately turned on, generating a pulse wave at the midpoint SW, which then generates an AC signal through the resonant circuit 3.

[0067] In one embodiment of the present invention, Figure 1 and Figure 3 As shown, the output rectifier circuit 5 includes a fourth switching transistor 51, a fifth switching transistor 52, and a second output filter circuit 53. The drain of the fourth switching transistor 51 and the drain of the fifth switching transistor 52 are connected to the first secondary side 42 and the second secondary side 43 of the transformer 4, respectively. The source of the fourth switching transistor 51 and the source of the fifth switching transistor 52 are both connected to the negative electrode of the second output filter circuit 53 and the secondary ground. The positive electrode of the second output filter circuit 53 is connected to the first secondary side 42 and the second secondary side 43 of the transformer 4 and the voltage sampling circuit 7. The fourth switching transistor 51 and the fifth switching transistor 52 are used to rectify the AC signal output by the transformer 4 and obtain a rated output voltage with low voltage ripple through the second output filter circuit 53.

[0068] In one embodiment of the present invention, Figure 1 and Figure 5 As shown, feedback circuit 8 includes a subtractor 81, a voltage-frequency oscillator 82, and a gate logic driver 83. Subtractor 81 has a negative input connected to voltage sampling circuit 7, a positive input connected to a reference frequency value, and an output connected to the input of voltage-frequency oscillator 82. The output of voltage-frequency oscillator 82 is connected to the input of gate logic driver 83, and the output of gate logic driver 83 is connected to driver circuit 9. Gate logic driver 83 includes a dead-time generation circuit 831, a high-voltage level shift circuit 832, and a low-voltage level shift circuit 833. The input of dead-time generation circuit 831 is connected to the output of voltage-frequency oscillator 82; the input of high-voltage level shift circuit 832 and the input of low-voltage level shift circuit 833 are connected to the output of dead-time generation circuit 831; and the output of high-voltage level shift circuit 832 and the output of low-voltage level shift circuit 833 are connected to driver circuit 9.

[0069] The pulse frequency modulation method is to subtract the reference frequency from the voltage sampling signal to obtain a driving signal through the voltage-frequency oscillator 82, and generate two complementary pulse signals with a certain dead time through the dead time generation circuit 831. The pulse signals are supplied to the second switch tube 21 and the third switch tube 22 through the high-voltage level shift circuit 832 and the low-voltage level shift circuit 833, thereby completing the closed-loop feedback to achieve the purpose of stabilizing the output voltage.

[0070] In one embodiment of the present invention, the first switch tube 13 is an N-channel silicon carbide field effect transistor; the second switch tube 21 and the third switch tube 22 are both N-channel silicon carbide field effect transistors; the fourth switch tube 51 and the fifth switch tube 52 are both N-channel silicon carbide field effect transistors.

[0071] In this embodiment, the half-bridge circuit 2 and the resonant circuit 3 form an LLC circuit;

[0072] like Figure 1 As shown, the design process of transformer 4 is as follows:

[0073] Calculate the theoretical turns ratio of the transformer primary side 41, the secondary side including the first secondary side 42 and the second secondary side 43, and the auxiliary power supply side 44 :

[0074] ;

[0075] in, is the input voltage of the LLC circuit, is the output voltage of the LLC circuit;

[0076] Calculate the minimum and maximum input voltage gains, expressed as 、 :

[0077] ;

[0078] ;

[0079] in, 、 are the maximum and minimum input voltages of the LLC circuit.

[0080] Calculate the resistive load rating of the LLC circuit system and reflected resistance ,as follows:

[0081] ;

[0082] ;

[0083] in, is the output power of the LLC circuit;

[0084] Calculate the key parameters of transformer 4, including: 、 、 as well as ; Q represents the quality factor, Represents the resonant capacitor 31, Represents the resonant inductance 32, represents the magnetizing inductance 33, and the relationship is as follows:

[0085] ;

[0086] ;

[0087] ;

[0088] ;

[0089] in, k1 Indicates the gain value, ranging from 2 to 10; express and Oscillation frequency;

[0090] Furthermore, the area product method AP is used to select the transformer core, and the relationship is as follows:

[0091] ;

[0092] in, is the cross-sectional area of ​​the transformer core; is the effective area of ​​the transformer core window; K2is a constant, usually taken as 0.017; is the change in magnetic flux density;

[0093] Furthermore, the number of turns on the primary side of transformer 4 is calculated ,as follows:

[0094] ;

[0095] in, is the rated frequency of the LLC circuit, is the maximum duty cycle of the second switch tube 21 and the third switch tube 22, The maximum magnetic induction intensity of the core of transformer 4;

[0096] Furthermore, the number of turns on the secondary side of the transformer 4 and the number of turns on the auxiliary power circuit 6 are calculated. ,as follows:

[0097] ;

[0098] in, is the ideal turns ratio of transformer 4;

[0099] In the embodiment of the present invention, the effective current value of the second switch tube 21 and the third switch tube 22 is expressed as , expressed as:

[0100] ;

[0101] in, is the output voltage of the LLC circuit, is the ideal turns ratio of transformer 4, is the load resistance value of the LLC circuit, according to In practical situations, when selecting a switching transistor, the rated current should be greater than the effective value of the current flowing through the switching transistor, preferably with a margin of more than double. A certain safety margin should also be left for the rated voltage to prevent the switching transistor from being broken down by instantaneous voltage spikes during operation.

[0102] In one embodiment of the present invention, Figure 1 and Figure 7 As shown, the auxiliary power supply circuit 6 includes a third output filter circuit 61, an anti-reverse polarity diode 62, and a clamping diode 63. The third output filter circuit 61 is connected to the cathode of the anti-reverse polarity diode 62 and the power ground. The anti-reverse polarity diode 62 has one end connected to the transformer 4 and the other end connected to the third output filter circuit 61. The clamping diode 63 has one end connected to the transformer 4 and the other end connected to the power ground. The anti-reverse polarity diode 62 and the clamping diode 63 limit voltage fluctuations and, in conjunction with the third output filter circuit 61, suppress ripple, thereby effectively protecting the drive circuit 9.

[0103] In one embodiment of the present invention, as 1 and Figure 7 As shown, the voltage sampling circuit 7 includes: a III-order compensation circuit 71, a three-terminal adjustable voltage regulator 72, and an optocoupler isolator 73. The input end of the III-order compensation circuit 71 is connected to the reference end of the three-terminal adjustable voltage regulator 72 and the output rectifier circuit 5, and the other end is connected to the input end of the optocoupler isolator 73 and the negative end of the three-terminal adjustable voltage regulator 72. The input end of the optocoupler isolator 73 is connected to the output end of the III-order compensation circuit 71 and the negative end of the three-terminal adjustable voltage regulator 72, and the output end is connected to the input end of the feedback circuit 8. The negative end of the three-terminal adjustable voltage regulator 72 is connected to the input end of the III-order compensation circuit 71 and the input end of the optocoupler isolator 73, the positive end is connected to the secondary ground, and the reference end is connected to the input end of the III-order compensation circuit 71 and the output rectifier circuit 5. The reference end of the three-terminal adjustable voltage regulator 72 receives the feedback voltage signal obtained by the output voltage of the entire system through resistor voltage division, and compares it with the built-in reference voltage. According to the change of the feedback voltage signal, the current from the negative pole to the positive pole of the three-terminal adjustable voltage regulator 72 is changed accordingly to control the current size of the light-emitting diode 731, that is, the brightness of the light. At the same time, the phototransistor 732 on the other side determines whether it is turned on by the brightness of the light-emitting diode 731. The optocoupler isolator 73 can isolate the electrical signals on the primary and secondary sides to prevent electrical collisions.

[0104] In one embodiment of the present invention, Figure 1 and Figure 6 As shown, the driving circuit 9 includes: a bootstrap circuit 91 and an independent pull-up and pouring circuit 92; the bootstrap circuit 91 includes: a bootstrap diode 911 and a bootstrap capacitor 912, one end of the bootstrap capacitor 912 is connected to the cathode of the bootstrap diode 911, and the other end is connected to the source of the second switch tube 21, the drain of the third switch tube 22 and the input end of the resonant circuit 3; the positive electrode of the bootstrap diode 911 is connected to the low voltage difference linear regulator 931, and the negative electrode is connected to the bootstrap capacitor 912.

[0105] The independent pull-up and pouring circuit 92 includes: an on-resistor 921 and an off-resistor 922; by adjusting the on-resistor 921 and the off-resistor 922 separately, the on-off time can be flexibly controlled, and the two paths do not affect each other, avoiding the problem of shutdown failure caused by a large voltage drop in the discharge circuit, and optimizing the problem of excessive on-off loss of the device.

[0106] like Figures 1 to 7As shown, the present invention provides a power converter with the characteristics of a wide input voltage range, small size and high efficiency. The current waveform is dynamically adjusted by the duty cycle of the switching tube in the power correction circuit 1, the phase difference between the current and voltage signals is compensated, and a constant DC voltage with small ripple is output. This compensates for the problem that the existing circuit-based power conversion circuit deviates from the resonant frequency point due to excessive changes in the input voltage or load, resulting in a decrease in the efficiency of the entire machine. In addition, the resonant inductor 32 is integrated into the transformer 4, which reduces the size of the entire machine and is suitable for various electronic products.

[0107] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described above separately, this does not mean that the measures in each embodiment cannot be advantageously used in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A power converter, characterized in that: include: A power correction circuit (1), a half-bridge circuit (2), a resonant circuit (3), a transformer (4), and an output rectifier circuit (5) connected in sequence; The feedback circuit (8) is connected to the output end of the output rectifier circuit (5), the feedback circuit (8) is connected to the drive circuit (9), and the drive circuit (9) is connected to the half-bridge circuit (2); The power correction circuit (1) is used to perform power factor correction on the external input voltage and then output a first DC voltage to the half-bridge circuit (2); The half-bridge circuit (2) is used to receive the first DC voltage output by the power correction circuit (1) and output a pulse voltage to the resonant circuit (3); The resonant circuit (3) is used to receive the pulse voltage output by the half-bridge circuit (2) and output a first AC voltage to the transformer (4); The transformer (4) is used to receive the first AC voltage output by the resonant circuit (3) and output a second AC voltage to the output rectifier circuit (5); The output rectifier circuit (5) is used to receive the second AC voltage output by the transformer (4) and output a second DC voltage; The feedback circuit (8) is used to output a control signal to the drive circuit (9) according to the second DC voltage; The driving circuit (9) is used to adjust the pulse voltage output by the half-bridge circuit (2) according to the control signal; The energy storage inductor (12) in the power correction circuit (1) has the functions of energy storage and discharge. The energy storage inductor (12) is expressed as L , the selection range is as follows: < L < ； in, Indicates the switching frequency of the gate control signal of the first switch tube (13) in the power correction circuit (1); 、 are the minimum and maximum input voltages of the power correction circuit (1); represents the input power of the power correction circuit (1); is the output voltage of the power correction circuit (1).

2. A power converter according to claim 1, characterized in that: The feedback circuit (8) is connected to the voltage sampling circuit (7), and the voltage sampling circuit (7) is connected to the output end of the output rectifier circuit (5). The voltage sampling circuit (7) is used to collect the second DC voltage output by the output rectifier circuit (5) and send a corresponding signal to the feedback circuit (8).

3. The power converter according to claim 1, wherein: The auxiliary power supply side (44) of the transformer (4) is connected to the auxiliary power supply circuit (6), the auxiliary power supply circuit (6) is connected to the drive circuit (9), and the auxiliary power supply circuit (6) is used to supply power to the drive circuit (9).

4. The power converter according to claim 2, wherein: The power correction circuit (1) comprises: a first input filter circuit (11), an energy storage inductor (12), a first switch tube (13), a Schottky diode (14) and a first output filter circuit (15); one end of the energy storage inductor (12) is connected to an external input voltage and the first input filter circuit (11), and the other end is connected to the drain of the first switch tube (13) and the positive electrode of the Schottky diode (14); the negative electrode of the Schottky diode (14) is connected to the first output filter circuit (15) and the input end of the half-bridge circuit (2).

5. The power converter according to claim 4, characterized in that: The half-bridge circuit (2) comprises: a second switch tube (21) and a third switch tube (22); the drain of the second switch tube (21) is connected to the negative electrode of the Schottky diode (14) and the first output filter circuit (15), and the source of the second switch tube (21) is connected to the drain of the third switch tube (22) and the input end of the resonant circuit (3).

6. The power converter according to claim 5, characterized in that: The output rectifier circuit (5) comprises: a fourth switch tube (51), a fifth switch tube (52), and a second output filter circuit (53); the drain of the fourth switch tube (51) and the drain of the fifth switch tube (52) are respectively connected to the first secondary side (42) and the second secondary side (43) of the transformer (4); the source of the fourth switch tube (51) and the source of the fifth switch tube (52) are both connected to the negative electrode of the second output filter circuit (53) and the secondary ground; the positive electrode of the second output filter circuit (53) is connected to the first secondary side (42) of the transformer (4) and the voltage sampling circuit (7).

7. The power converter according to claim 2, wherein: The feedback circuit (8) includes: a subtractor (81), a voltage-frequency oscillator (82) and a gate logic driver (83); the negative input terminal of the subtractor (81) is connected to the voltage sampling circuit (7), the positive input terminal is connected to the reference frequency value, and the output terminal is connected to the input terminal of the voltage-frequency oscillator (82); the output terminal of the voltage-frequency oscillator (82) is connected to the input terminal of the gate logic driver (83), and the output terminal of the gate logic driver (83) is connected to the drive circuit (9).

8. The power converter according to claim 4, wherein: The first switch tube (13) is an N-channel silicon carbide field effect transistor.

9. The power converter according to claim 5, wherein: The second switch tube (21) and the third switch tube (22) are both N-channel silicon carbide field effect transistors.

10. The power converter according to claim 6, characterized in that: The fourth switch tube (51) and the fifth switch tube (52) are both N-channel silicon carbide field effect transistors.

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