Double-winding magnetic core resonant high-frequency soft switching DC / AC converter

Abstract

The invention discloses a dual-winding magnetic core resonant high-frequency soft switching DC / AC converter, which comprises a bridge-arm-free straight-through dual-channel architecture main power circuit, a current positive dual-winding magnetic integrated passive resonant circuit, a current negative dual-winding magnetic integrated passive resonant circuit, a dynamic potential equalization circuit and a harmonic suppression shaping circuit, according to the invention, the soft switching is realized without any additional switching tube, so that the design of the control circuit is greatly simplified, and the soft switching condition of the high-frequency switching tube is created by using a small number of elements, which is greatly helpful for improving the power density of the system. Due to the existence of the turn ratio of the energy injection side winding to the energy receiving side winding of the double-winding magnetic core mutual inductance element, the converter can easily reduce the voltage stress and the current stress of a switching tube, so that the switching loss is reduced, the efficiency is improved, the working frequency of a system is improved, and the system reliability is improved. Therefore, the element size of the harmonic suppression shaping part of the converter is reduced, and the power density of the converter is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inverters in power conversion devices, and particularly to a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter. Background Art

[0002] In recent years, the switching frequency of the switching tubes in DC / AC converters has been increasing. The advantage of the increasing switching frequency is that the volume of the harmonic suppression components of the converter can be greatly reduced, which is beneficial to improving the overall power density of the converter, and can also make the converter respond faster to load changes and improve the dynamic performance of the system. However, there is an inherent problem with the increasing switching frequency of the switching tubes, that is, their switching process is hard switching, resulting in relatively large switching losses and electromagnetic interference, which will limit the working efficiency of the converter, making the switching frequency of the switching tubes in the converter not too high. Therefore, soft-switching technology has become a research hotspot in recent years. Summary of the Invention

[0003] Technical Objective: Aiming at the defects of the full-bridge converter in the prior art, the present invention discloses a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter, proposes a bridge-arm-free direct-through dual-channel main power transmission architecture, and connects two high-frequency modulated power switching tubes in the bridge-arm-free direct-through dual-channel main power transmission architecture to a group of passive resonant circuits based on dual-winding magnetic core mutual inductance elements respectively. At the same time, a dynamic potential equalization circuit and a harmonic suppression and shaping circuit are introduced, and a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter is proposed, in which two high-frequency modulated power switching tubes in the bridge-arm-free direct-through dual-channel main power transmission architecture can achieve soft switching without additional switches and greatly simplify the control circuit.

[0004] Technical Solution: To achieve the above technical objective, the present invention adopts the following technical solutions.

[0005] A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter includes a bridge-arm-free direct-through dual-channel architecture main power circuit, a current-forward dual-winding magnetic integration passive resonant circuit, a current-backward dual-winding magnetic integration passive resonant circuit, a dynamic potential equalization circuit, and a harmonic suppression and shaping circuit;

[0006] Among them, the bridge-arm-free direct-through dual-channel architecture main power circuit is used to provide an appropriate main power transmission path for the positive and negative harmonic suppression inductor currents i L and perform high-frequency chopping on the input voltage; the bridge-arm-free direct-through dual-channel architecture main power circuit includes a positive harmonic suppression inductor current transmission path and a negative harmonic suppression inductor current transmission path. The positive harmonic suppression inductor current transmission path includes a first high-frequency modulated switch tube S1, a first current commutation power-frequency modulated switch tube Q L1, the first freewheeling diode D1; the negative harmonic suppression inductor current transmission path includes the second high-frequency modulation switch tube S2 and the second current commutation power-frequency modulation switch tube Q L2 and the second freewheeling diode D2;

[0007] The positive current double-winding magnetic integration passive resonant circuit is connected to the main power circuit of the bridge-arm-free direct-through dual-channel architecture, and is used to create soft-switching conditions for the first high-frequency modulation switch tube S1 during high-frequency switching operation, thereby reducing the switching loss and current-voltage stress of the high-frequency switch tube;

[0008] The negative current double-winding magnetic integration passive resonant circuit is connected to the main power circuit of the bridge-arm-free direct-through dual-channel architecture, and is used to create soft-switching conditions for the second high-frequency modulation switch tube S2 during high-frequency switching operation, thereby reducing the switching loss and current-voltage stress of the high-frequency switch tube;

[0009] The dynamic potential equalization circuit is connected to the harmonic suppression and shaping circuit, and is used for the dynamic regulation of the potential at the harmonic suppression capacitor end, so that the harmonic suppression and shaping circuit can correctly output a voltage in the appropriate direction;

[0010] The harmonic suppression and shaping circuit is connected to the main power circuit of the bridge-arm-free direct-through dual-channel architecture, and is used for rectifying the output voltage waveform and suppressing the generation of high-frequency harmonics.

[0011] Beneficial effects:

[0012] (1) The high-frequency modulation power switch tubes in the proposed topology can achieve soft switching, reduce switching losses, improve the overall efficiency of the converter, and can limit the influence of electromagnetic interference;

[0013] (2) The power switch tubes of the proposed topology can operate at a high switching frequency, which helps to reduce the volume of the harmonic suppression components, and soft switching can be achieved with only a small number of components, which is of great help for improving the power density of the system;

[0014] (3) The realization of soft switching does not require additional switches for assistance, which will greatly simplify the logic of the control circuit.

[0015] (4) The main power freewheeling diodes of this topology turn off under ZV and ZCS conditions, and the freewheeling diodes of the resonant module turn off under ZCS conditions, which avoids the generation of reverse recovery current of the diodes, so there is no reverse recovery problem.

[0016] (5) Due to the existence of the turns ratio between the energy injection side winding and the energy receiving side winding of the double-winding magnetic core mutual inductance element, this topology can reduce the voltage and current stress of the switch tubes by selecting an appropriate turns ratio, which is beneficial for the cost control of the converter. Description of the drawings

[0017] Figure 1 Topological structure diagram of a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to the present invention;

[0018] Figure 2 Control and drive waveform diagram of each switching tube when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to the present invention operates in four quadrants;

[0019] Figure 3 Key waveform diagram of the proposed converter when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter circuit according to the present invention operates in the first quadrant;

[0020] Figures 4 to 9 Schematic diagrams of each switching mode when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter circuit according to the present invention operates in the first quadrant;

[0021] Figures 10 to 15 Schematic diagrams of each switching mode when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter circuit according to the present invention operates in the second quadrant;

[0022] Figures 16 to 21 Schematic diagrams of each switching mode when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter circuit according to the present invention operates in the third quadrant;

[0023] Figures 22 to 27 Schematic diagrams of each switching mode when a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter circuit according to the present invention operates in the fourth quadrant. Detailed implementation manners

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] As shown in the appendix Figure 1 A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter includes a main power circuit 1 with a non-bridge-arm direct-through dual-channel architecture, a positive-current dual-winding magnetic integrated passive resonant circuit 2, a negative-current dual-winding magnetic integrated passive resonant circuit 3, a dynamic potential equalization circuit 4, and a harmonic suppression and shaping circuit 5;

[0026] Among them, the main power circuit 1 with a non-bridge-arm direct-through dual-channel architecture is used to suppress the harmonic inductance currents i of the positive and negative directions LProvide an adapted main power transmission path and perform high-frequency chopping on the input voltage. The main power circuit 1 of the bridge-less direct-through dual-channel architecture includes a positive harmonic suppression inductor current transmission path and a negative harmonic suppression inductor current transmission path. Among them, the positive and negative in the positive harmonic suppression inductor current transmission path and the negative harmonic suppression inductor current transmission path refer to the positive and negative directions of the harmonic suppression inductor current i L L , and the same applies to the positive current double-winding magnetically integrated passive resonant circuit 2 and the negative current double-winding magnetically integrated passive resonant circuit 3; the positive harmonic suppression inductor current transmission path includes the first high-frequency modulation switch tube S1, the first current commutation power-frequency modulation switch tube Q L1 L1 , and the first freewheeling diode D1; the negative harmonic suppression inductor current transmission path includes the second high-frequency modulation switch tube S2, the second current commutation power-frequency modulation switch tube Q L2 L2 and the second freewheeling diode D2;

[0027] As shown in the appendix Figure 1 Figure 1 , the circuit connection structure is as follows:

[0028] The main power circuit 1 of the bridge-less direct-through dual-channel architecture includes the first high-frequency modulation switch tube S1 and the second high-frequency modulation switch tube S2, the first current commutation power-frequency modulation switch tube Q L1 L1 and the second current commutation power-frequency modulation switch tube Q 12 12 , as well as the first freewheeling diode D1 and the second freewheeling diode D2; among them, the source of the first high-frequency modulation switch tube S1 is connected to the drain of the first current commutation power-frequency modulation switch tube Q L1 L1 and the cathode of the first freewheeling diode D1. The anode of the first freewheeling diode D1 is connected to the negative pole of the input power supply V in in , jointly constituting the positive harmonic suppression inductor current transmission path and performing high-frequency chopping on the input voltage. The drain of the second high-frequency modulation switch tube S2 is connected to the source of the second current commutation power-frequency modulation switch tube Q L2 L2 and the anode of the second freewheeling diode D2. The cathode of the second freewheeling diode D2 is connected to the positive pole of the input power supply V in in , jointly constituting the negative harmonic suppression inductor current transmission path and performing high-frequency chopping on the input voltage. And the drain of the second current commutation power-frequency modulation switch tube Q L2 L2 is connected to the source of the first current commutation power-frequency modulation switch tube Q L1 L1 . The positive harmonic suppression inductor current transmission path and the negative harmonic suppression inductor current transmission path constitute the overall main power transmission path.

[0029] Among them, the current-forward dual-winding magnetically integrated passive resonant circuit 2 is connected to the main power circuit 1 of the non-bridge-arm direct-through dual-channel architecture, and is used to create soft-switching conditions for the first high-frequency modulation switch tube S1 during high-frequency switching operation, thereby reducing the switching loss and current-voltage stress of the high-frequency switch tube.

[0030] The current-forward dual-winding magnetically integrated passive resonant circuit 2 includes a first energy injection magnetic pole winding inductor L r1 , a first energy receiving magnetic pole winding inductor L r2 , a first resonant cavity energy interaction capacitor C r1 and a third freewheeling diode D a . Among them, the first energy injection magnetic pole winding inductor L r1 , the first energy receiving magnetic pole winding inductor L r2 form a group of dual-winding magnetic core mutual inductance elements. The first energy injection magnetic pole winding inductor L r1 serves as the primary side, and the first energy receiving magnetic pole winding inductor L r2 serves as the secondary side; when the dual-winding magnetic core resonates with the first resonant cavity energy interaction capacitor C r1 , the energy of the inductor and the capacitor will exchange reactive power. The magnetic pole synchronous terminal of the first energy injection magnetic pole winding inductor L r1 and the non-magnetic pole synchronous terminal of the first energy receiving magnetic pole winding inductor L r2 are connected to the positive pole of the input power supply V in . The non-magnetic pole synchronous terminal of the first energy injection magnetic pole winding inductor L r1 is connected to the drain of the first high-frequency modulation switch tube S1. The magnetic pole synchronous terminal of the first energy receiving magnetic pole winding inductor L r2 is connected to the cathode of the third freewheeling diode D a . The anode of the third freewheeling diode D a is connected to the cathode of the first freewheeling diode D1, the source of the first high-frequency modulation switch tube S1, and the drain of the first current commutation power-frequency modulation switch tube Q L1 , and is connected to one end of the first resonant cavity energy interaction capacitor C r1 . The other end of the first resonant cavity energy interaction capacitor C r1 is connected to the negative pole of the input power supply V in . Therefore, the first energy injection magnetic pole winding inductor L r1 , the first energy receiving magnetic pole winding inductor L r2 [[ID=D47]], the first resonant cavity energy interaction capacitor C r1 and the third freewheeling diode D a together constitute the current-forward dual-winding magnetically integrated passive resonant circuit, providing ZCS turn-on and ZVS turn-off conditions for the first high-frequency modulation switch tube S1.

[0031] The negative current dual-winding magnetically integrated passive resonant circuit 3 is connected to the main power circuit 1 with a non-bridge-arm direct-through dual-channel architecture, and is used to create soft-switching conditions for the second high-frequency modulation switch tube S2 during high-frequency switching operation, thereby reducing the switching loss and current-voltage stress of the high-frequency switch tube.

[0032] The negative current dual-winding magnetically integrated passive resonant circuit 3 includes a second energy injection magnetic pole winding inductor L r3 , a second energy receiving magnetic pole winding inductor L r4 , a second resonant cavity energy interaction capacitor C r2 and a fourth freewheeling diode D b . Among them, the second energy injection magnetic pole winding inductor L r3 and the second energy receiving magnetic pole winding inductor L r4 form a set of dual-winding magnetic core mutual inductance elements. The second energy injection magnetic pole winding inductor L r3 serves as the primary side, and the second energy receiving magnetic pole winding inductor L r4 serves as the secondary side; when the dual-winding magnetic core resonates with the second resonant cavity energy interaction capacitor C r2 , the energy of the inductor and the capacitor will perform reactive power exchange. Among them, the non-magnetic pole synchronous terminal of the second energy injection magnetic pole winding inductor L r3 and the anode of the fourth freewheeling diode D b are connected to the negative pole of the input power supply V in . The magnetic pole synchronous terminal of the second energy injection magnetic pole winding inductor L r3 is connected to the source electrode of the second high-frequency modulation switch tube S2. The magnetic pole synchronous terminal of the second energy receiving magnetic pole winding inductor L r4 is connected to the cathode of the fourth freewheeling diode D b . The non-magnetic pole synchronous terminal of the second energy receiving magnetic pole winding inductor L r4 is connected to the anode of the second freewheeling diode D2, the drain of the second high-frequency modulation switch tube S2, and the source electrode of the second current commutation power frequency modulation switch tube Q L2 , and is connected to one end of the second resonant cavity energy interaction capacitor C r2 . The other end of the second resonant cavity energy interaction capacitor C r2 is connected to the positive pole of the input power supply V in . Therefore, the second energy injection magnetic pole winding inductor L r3 , the second energy receiving magnetic pole winding inductor L r4 , the second resonant cavity energy interaction capacitor C r2 and the fourth freewheeling diode D b together constitute the negative current dual-winding magnetically integrated passive resonant circuit, providing ZCS turn-on and ZVS turn-off conditions for the second high-frequency modulation switch tube S2.

[0033] The dynamic potential equalization circuit 4 is connected to the harmonic suppression and shaping circuit 5, and is used for dynamically adjusting the potential at the harmonic suppression capacitor terminal, so that the harmonic suppression and shaping circuit can correctly output a voltage suitable for the direction. The dynamic potential equalization circuit 4 includes a first dynamic potential regulating power frequency switching transistor Q1 and a second dynamic potential regulating power frequency switching transistor Q2. Among them, the source of the first dynamic potential regulating power frequency switching transistor Q1 is connected to the negative pole of the input power supply V in ; the drain of the first dynamic potential regulating power frequency switching transistor Q1 is connected to the source of the second dynamic potential regulating power frequency switching transistor Q2 and grounded, and the drain of the second dynamic potential regulating power frequency switching transistor Q2 is connected to the positive pole of the input power supply V in . Therefore, the first dynamic potential regulating power frequency switching transistor Q1 and the second dynamic potential regulating power frequency switching transistor Q2 together constitute a dynamic potential equalization circuit to perform a commutation operation on the output voltage.

[0034] The harmonic suppression and shaping circuit 5 is connected to the bridge-free direct-through dual-channel architecture main power circuit 1 and is used for rectifying the output voltage waveform and suppressing the generation of high-frequency harmonics. The harmonic suppression and shaping circuit 5 includes a harmonic suppression inductor L f and a harmonic suppression capacitor C f . Among them, one end of the harmonic suppression inductor L f is connected to the drain of the second current commutation power frequency modulation switching transistor Q L2 and the source of the first current commutation power frequency modulation switching transistor Q L1 . The other end of the harmonic suppression inductor L f is connected to one end of the output harmonic suppression capacitor C f . The other end of the harmonic suppression capacitor C f is connected to the drain of the first dynamic potential regulating power frequency switching transistor Q1 and the source of the second dynamic potential regulating power frequency switching transistor Q2 and grounded; the current on the harmonic suppression inductor L f is denoted as the inductor current i L . The voltage across the harmonic suppression capacitor C f is the output voltage V O . It is defined that the direction of the inductor current i L flowing to the positive terminal of the harmonic suppression capacitor C f is the positive direction, as shown in the appendix Figure 1 . Therefore, the harmonic suppression inductor LA f and the harmonic suppression capacitor C f together constitute a harmonic suppression and shaping circuit to rectify the output waveform and suppress the generation of high-frequency harmonics.

[0035] Taking the output voltage V O as the abscissa and the inductor current i L as the ordinate, the converter of the present invention can be divided into four quadrants during operation. The following takesFigure 1 The main circuit structure is shown, and its control drive waveforms and output waveforms in the four quadrants are as Figure 2 shown. The control signals are connected to the gates of the respective switching tubes to provide conduction and turn-off of the respective switching tubes. Combining Figures 4 - 27 Specifically discussed is the working principle and working mode of a dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter of the present invention during the working process in the four quadrants under PWM control, i.e., unipolar SPWM modulation mode. The specific electrical components involved include: two high-frequency main power switching tubes, two current-commutating power-frequency main power switching tubes, two dynamic potential-regulating power-frequency switching tubes, four freewheeling diodes, two dual-winding magnetic core mutual inductance elements, two resonant cavity energy interaction capacitors, a harmonic suppression inductor, a harmonic suppression capacitor, and an external power supply. The present invention does not require any additional switching tubes to achieve soft switching, which greatly simplifies the design of the control circuit, and creates soft-switching conditions for high-frequency switching tubes with only a small number of components, which is extremely helpful for improving the power density of the system. In addition, due to the existence of the turns ratio between the energy injection side winding and the energy receiving side winding of the dual-winding magnetic core mutual inductance element, the converter can easily reduce the voltage stress and current stress of the switching tubes, thereby reducing the switching loss and improving the efficiency, which is beneficial to increasing the operating frequency of the system, and further reducing the component volume of the harmonic suppression and shaping part of the converter, and improving the power density of the converter.

[0036] When the dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter operates in the first quadrant (V O > 0, i L > 0):

[0037] When the circuit operates in the first quadrant, the first dynamic potential-regulating power-frequency switching tube Q1 in the dynamic potential equalization circuit and the first current-commutating power-frequency modulation switching tube Q L1 in the non-bridge-arm direct-through dual-channel architecture main power circuit are turned on, and the first high-frequency modulation switching tube S1 in the non-bridge-arm direct-through dual-channel architecture main power circuit performs high-frequency switching operations, and the remaining switching tubes are all turned off. Before working mode 1, it is assumed that the first high-frequency modulation switching tube S1 is turned off and the harmonic suppression inductor current i L flows through the first freewheeling diode D1. The key waveforms during the operation in this quadrant are as Figure 3 shown. Since the key waveforms during the operation in other quadrants are similar, they will not be listed again when discussing the working modes in other quadrants. The respective working modes during the operation in this quadrant are as Figures 4 - 9 shown.

[0038] Working mode 1: As Figure 4 shown, the first high-frequency modulation switching tube S1 is turned on. Due to the inductance of the energy injection magnetic pole winding of the dual-winding magnetic core, i.e., the first energy injection magnetic pole winding inductance L r1Due to the existence of L , the current flowing through the first high-frequency modulation switch tube S1 will slowly rise linearly. Therefore, the first high-frequency modulation switch tube S1 conducts under ZCS conditions. At this time, the current in the first freewheeling diode D1 will decrease linearly. When the current of the first high-frequency modulation switch tube S1 rises to the harmonic suppression inductor current i

[0039] Working mode 2: As shown in Figure 5 , since the current of the first high-frequency modulation switch tube S1 has risen to the harmonic suppression inductor current i L , the first freewheeling diode D1 is turned off, and it is turned off under ZCS conditions. The first energy injection magnetic pole winding inductor L r1 of the double-winding magnetic core and the first resonant cavity energy interaction capacitor C r1 start to resonate. Due to the existence of the first resonant cavity energy interaction capacitor C r1 , the rise of the voltage of the first freewheeling diode D1 can be considered slow. Therefore, the turn-off of the first freewheeling diode D1 is ZCZVS. When the voltage of the first resonant cavity energy interaction capacitor C r1 rises to the input voltage V in , this working mode ends.

[0040] Working mode 3: As shown in Figure 6 , when the voltage of the first resonant cavity energy interaction capacitor C r1 rises to the input voltage V in , the current starts to conduct through the third freewheeling diode D a in the positive direction of the double-winding magnetic integrated passive resonant circuit, and the conduction is ZVS. The voltage of the first resonant cavity energy interaction capacitor C r1 is clamped at the input voltage V in , and the total ampere-turns of the first energy injection magnetic pole winding inductor L r1 and the first energy receiving magnetic pole winding inductor L r2 of the double-winding magnetic core should remain constant. When the first high-frequency modulation switch tube S1 is turned off, this working mode ends.

[0041] Working mode 4: As shown in Figure 7 , at this time, the first high-frequency modulation switch tube S1 is turned off under ZVS conditions. However, in actual situations, due to the leakage of the energy of the double-winding magnetic core mutual inductance element, the characteristics of leakage inductance will be shown. Therefore, small voltage spikes will appear at both ends of the switch, but the peak value of the spikes is usually much smaller than the maximum voltage of the switch. Therefore, the first high-frequency modulation switch tube S1 can also be turned off under nearly ZVS conditions. The ampere-turns of the first energy injection magnetic pole winding inductor L r1 of the double-winding magnetic core are transferred to the first energy receiving magnetic pole winding inductor L r2 , and the first resonant cavity energy interaction capacitor Cr1 Discharge together with the current of the harmonic suppression inductance current i L and the inductance L of the first energy receiving magnetic pole winding r2 until its voltage drops to zero, and this operating mode ends.

[0042] Operating mode 5: As Figure 8 shown, when the voltage of the first resonant cavity energy interaction capacitor C r1 drops to zero, this operating mode starts. At this time, the first freewheeling diode D1 conducts under the condition of ZVS. In this operating mode, the current of the inductance L of the first energy receiving magnetic pole winding r2 decreases linearly. When the current of the inductance L of the first energy receiving magnetic pole winding r2 drops to zero, this operating mode ends. At this time, the current flows through the third freewheeling diode D a in the current positive double-winding magnetic integrated passive resonant circuit and turns off under the condition of ZCS.

[0043] Operating mode 6: As Figure 9 shown, the harmonic suppression inductance current i L flows through the first freewheeling diode D1 for freewheeling, and the current through the double-winding magnetic core mutual inductance element remains 0. The voltage of the first resonant cavity energy interaction capacitor C r1 remains at 0. When the first high-frequency modulation switch tube S1 conducts, this operating mode ends and thus switches to the next operating mode 1, and so on in a cycle.

[0044] When the double-winding magnetic core resonant high-frequency soft-switching DC / AC converter operates in the second quadrant (V O > 0, i L < 0):

[0045] When the circuit operates in the second quadrant, the first dynamic potential regulating power frequency switch tube Q1 in the dynamic potential equalizing circuit and the second current commutation power frequency modulation switch tube Q L2 in the non-bridge-arm direct-through dual-channel architecture main power circuit conduct, and the second high-frequency modulation switch tube S2 in the non-bridge-arm direct-through dual-channel architecture main power circuit performs high-frequency switching operations, and the rest of the switch tubes are all turned off. Before operating mode 1, it is assumed that the second high-frequency modulation switch tube S2 is disconnected and the harmonic suppression inductance current i L flows through the second freewheeling diode D2. The operating modes during the operation in this quadrant are as Figures 10 - 15 shown.

[0046] Operating mode 1: As Figure 10 shown, the second high-frequency modulation switch tube S2 conducts. Due to the second energy injection magnetic pole winding inductance L of the double-winding magnetic core r3In the presence of..., the current flowing through the second high-frequency modulation switch tube S2 will slowly rise linearly. Therefore, the second high-frequency modulation switch tube S2 conducts under ZCS conditions. At this time, the current in the second freewheeling diode D2 will decrease linearly. When the current of the second high-frequency modulation switch tube S2 rises to the harmonic suppression inductor current i L this operating mode ends.

[0047] Operating mode 2: As Figure 11 shown, since the current of the second high-frequency modulation switch tube S2 has risen to the harmonic suppression inductor current i L , the second freewheeling diode D2 turns off, and it turns off under ZCS conditions. The second energy injection pole winding inductor L r3 of the dual-winding magnetic core and the second resonant cavity energy interaction capacitor C r2 start to resonate. Due to the existence of the second resonant cavity energy interaction capacitor C r2 , the rise of the voltage of the second freewheeling diode D2 can be considered slow. Therefore, the turn-off of the second freewheeling diode D2 is ZCZVS. When the voltage of the second resonant cavity energy interaction capacitor C r2 rises to the input voltage V in , this operating mode ends.

[0048] Operating mode 3: As Figure 12 shown, when the voltage of the second resonant cavity energy interaction capacitor C r2 rises to the input voltage V in , the fourth freewheeling diode D b in the current negative dual-winding magnetic integrated passive resonant circuit starts to conduct, and the conduction is ZVS. The voltage of the second resonant cavity energy interaction capacitor C r2 is clamped at the input voltage V in , and the total ampere-turns of the second energy injection pole winding inductor L r3 and the second energy receiving pole winding inductor L r4 of the dual-winding magnetic core should remain constant. When the second high-frequency modulation switch tube S2 turns off, this operating mode ends.

[0049] Operating mode 4: As Figure 13 shown, at this time, the second high-frequency modulation switch tube S2 turns off under ZVS conditions. However, in actual situations, due to the energy leakage of the dual-winding magnetic core mutual inductance element, which exhibits the characteristics of leakage inductance, small voltage spikes appear across the switch, but the peak value of the spikes is usually much smaller than the maximum voltage of the switch. Therefore, the second high-frequency modulation switch tube S2 can also turn off under nearly ZVS conditions. The ampere-turns of the second energy injection pole winding inductor L r3 of the dual-winding magnetic core are transferred to the second energy receiving pole winding inductor L r4 , and the second resonant cavity energy interaction capacitor Cr2 Discharge together with the current of the harmonic suppression inductance current i L and the inductance L of the second energy receiving magnetic pole winding r4 until its voltage drops to zero, and this operating mode ends.

[0050] Operating mode 5: As Figure 14 shown, when the voltage of the second resonant cavity energy interaction capacitor C r2 drops to zero, this operating mode starts. At this time, the second freewheeling diode D2 conducts under the condition of ZVS. In this operating mode, the current of the inductance L of the second energy receiving magnetic pole winding r4 decreases linearly. When the current of the inductance L of the second energy receiving magnetic pole winding r4 drops to zero, this operating mode ends. At this time, the fourth freewheeling diode D b in the current negative double-winding magnetic integration passive resonant circuit turns off under the condition of ZCS.

[0051] Operating mode 6: As Figure 15 shown, the harmonic suppression inductance current i L flows through the second freewheeling diode D2 for freewheeling, and the current through the double-winding magnetic core mutual inductance element remains 0. The voltage of the second resonant cavity energy interaction capacitor C r2 remains at 0. When the second high-frequency modulation switch tube S2 conducts, this operating mode ends.

[0052] When the double-winding magnetic core resonant high-frequency soft-switching DC / AC converter operates in the third quadrant (V O < 0, i L < 0):

[0053] When the circuit operates in the third quadrant, the second dynamic potential regulating power frequency switch tube Q2 in the dynamic potential equalizing circuit and the second current commutation power frequency modulation switch tube Q L2 in the main power circuit of the bridge-free direct-through dual-channel architecture conduct, and the second high-frequency modulation switch tube S2 in the main power circuit of the bridge-free direct-through dual-channel architecture performs high-frequency switching operations, and the rest of the switch tubes are turned off. Before operating mode 1, it is assumed that the second high-frequency modulation switch tube S2 is turned off and the harmonic suppression inductance current i L flows through the second freewheeling diode D2. The operating modes during the operation in this quadrant are as Figures 16 - 21 shown.

[0054] Operating mode 1: As Figure 16 shown, the second high-frequency modulation switch tube S2 conducts. Due to the second energy injection magnetic pole winding inductance L of the double-winding magnetic core r3In the presence of..., the current flowing through the second high-frequency modulation switch tube S2 will slowly rise linearly. Therefore, the second high-frequency modulation switch tube S2 conducts under ZCS conditions. At this time, the current in the second freewheeling diode D2 will linearly decrease. When the current of the second high-frequency modulation switch tube S2 rises to the harmonic suppression inductor current i L This operating mode ends.

[0055] Operating mode 2: As Figure 17 shown, since the current of the second high-frequency modulation switch tube S2 has risen to the harmonic suppression inductor current i L , the second freewheeling diode D2 disconnects and turns off under ZCS conditions. The second energy injection pole winding inductor L r3 of the dual-winding magnetic core and the second resonant cavity energy interaction capacitor C r2 start to resonate. Due to the existence of the second resonant cavity energy interaction capacitor C r2 , the rise of the voltage of the second freewheeling diode D2 can be considered slow. Therefore, the turn-off of the second freewheeling diode D2 is ZCZVS. When the voltage of the second resonant cavity energy interaction capacitor C r2 rises to the input voltage V in , this operating mode ends.

[0056] Operating mode 3: As Figure 18 shown, when the voltage of the second resonant cavity energy interaction capacitor C r2 rises to the input voltage V in , the fourth freewheeling diode D b in the current negative dual-winding magnetic integrated passive resonant circuit starts to conduct, and the conduction is ZVS. The voltage of the second resonant cavity energy interaction capacitor C r2 is clamped at the input voltage V in , and the total ampere-turns of the second energy injection pole winding inductor L r3 and the second energy receiving pole winding inductor L r4 of the dual-winding magnetic core should remain constant. When the second high-frequency modulation switch tube S2 turns off, this operating mode ends.

[0057] Operating mode 4: As Figure 19 shown, at this time, the second high-frequency modulation switch tube S2 turns off under ZVS conditions. However, in actual situations, due to the leakage of the energy of the dual-winding magnetic core mutual inductance element, the leakage inductance characteristic is exhibited, and small voltage spikes appear at both ends of the switch. However, the peak value of the spike is usually much smaller than the maximum voltage of the switch. Therefore, the second high-frequency modulation switch tube S2 can also turn off under nearly ZVS conditions. The ampere-turns of the second energy injection pole winding inductor L r3 of the dual-winding magnetic core are transferred to the second energy receiving pole winding inductor L r4 , and the second resonant cavity energy interaction capacitor Cr2 Discharge together with the harmonic suppression inductor current i L and the inductance L of the second energy receiving magnetic pole winding r4 until its voltage drops to zero, and this operating mode ends.

[0058] Operating mode 5: As Figure 20 shown, when the voltage of the second resonant cavity energy interaction capacitor C r2 drops to zero, this operating mode starts. At this time, the second freewheeling diode D2 conducts under the condition of ZVS. In this operating mode, the current of the inductance L of the second energy receiving magnetic pole winding r4 decreases linearly. When the current of the inductance L of the second energy receiving magnetic pole winding r4 drops to zero, this operating mode ends. At this time, the fourth freewheeling diode D b in the current negative double-winding magnetic integration passive resonant circuit turns off under the condition of ZCS.

[0059] Operating mode 6: As Figure 21 shown, the harmonic suppression inductor current i L flows through the second freewheeling diode D2 for freewheeling, and the current passing through the double-winding magnetic core mutual inductance element remains 0. The voltage of the second resonant cavity energy interaction capacitor C r2 remains at 0. When the second high-frequency modulation switch tube S2 conducts, this operating mode ends and thus switches to the next operating mode 1, and so on in a cycle.

[0060] When the double-winding magnetic core resonant high-frequency soft-switching DC / AC converter operates in the fourth quadrant (V O < 0, i L > 0):

[0061] When the circuit operates in the fourth quadrant, the second dynamic potential regulating power frequency switch tube Q2 in the dynamic potential equalization circuit and the first current commutation power frequency modulation switch tube Q L1 in the non-bridge-arm direct-through dual-channel architecture main power circuit conduct. The first high-frequency modulation switch tube S1 in the non-bridge-arm direct-through dual-channel architecture main power circuit performs high-frequency switching operations, and the rest of the switch tubes are all turned off. Before operating mode 1, it is assumed that the first high-frequency modulation switch tube S1 is off and the harmonic suppression inductor current i L flows through the first freewheeling diode D1. The operating modes during the operation in this quadrant are as Figures 22 - 27 shown.

[0062] Operating mode 1: As Figure 22 shown, the first high-frequency modulation switch tube S1 conducts. Due to the first energy injection magnetic pole winding inductance L of the double-winding magnetic core r1Due to the existence of L , the current flowing through the first high-frequency modulation switch tube S1 will slowly rise linearly. Therefore, the first high-frequency modulation switch tube S1 conducts under ZCS conditions. At this time, the current in the first freewheeling diode D1 will decrease linearly. When the current of the first high-frequency modulation switch tube S1 rises to the harmonic suppression inductor current i

[0063] Working mode 2: As Figure 23 shown, since the current of the first high-frequency modulation switch tube S1 has risen to the harmonic suppression inductor current i L , the first freewheeling diode D1 is turned off, and it is turned off under ZCS conditions. The first energy injection magnetic pole winding inductor L r1 of the dual-winding magnetic core and the first resonant cavity energy interaction capacitor C r1 start to resonate. Due to the existence of the first resonant cavity energy interaction capacitor C r1 , the rise of the voltage of the first freewheeling diode D1 can be considered slow. Therefore, the turn-off of the first freewheeling diode D1 is ZCZVS. When the voltage of the first resonant cavity energy interaction capacitor C r1 rises to the input voltage V in , this working mode ends.

[0064] Working mode 3: As Figure 24 shown, when the voltage of the first resonant cavity energy interaction capacitor C r1 rises to the input voltage V in , the current starts to conduct through the third freewheeling diode D a in the positive direction of the dual-winding magnetic integrated passive resonant circuit, and the conduction is ZVS. The voltage of the first resonant cavity energy interaction capacitor C r1 is clamped at the input voltage V in , and the total ampere-turns of the first energy injection magnetic pole winding inductor L r1 and the first energy receiving magnetic pole winding inductor L r2 of the dual-winding magnetic core should remain constant. When the first high-frequency modulation switch tube S1 is turned off, this working mode ends.

[0065] Working mode 4: As Figure 25 shown, at this time, the first high-frequency modulation switch tube S1 is turned off under ZVS conditions. However, in actual situations, due to the leakage of the energy of the dual-winding magnetic core mutual inductance element, the characteristics of leakage inductance are shown, and small voltage spikes appear at both ends of the switch. However, the peak value of its spike is usually much smaller than the maximum voltage of the switch. Therefore, the first high-frequency modulation switch tube S1 can also be turned off under nearly ZVS conditions. The ampere-turns of the first energy injection magnetic pole winding inductor L r1 of the dual-winding magnetic core are transferred to the first energy receiving magnetic pole winding inductor L r2 , and the first resonant cavity energy interaction capacitor Cr1 Discharges together with the harmonic suppression inductor current i L and the inductance L of the first energy receiving magnetic pole winding r2 until its voltage drops to zero, and this operating mode ends.

[0066] Operating mode 5: As Figure 26 shown, when the voltage of the first resonant cavity energy interaction capacitor C r1 drops to zero, this operating mode starts. At this time, the first freewheeling diode D1 conducts under the condition of ZVS. In this operating mode, the current of the inductance L of the first energy receiving magnetic pole winding r2 decreases linearly. When the current of the inductance L of the first energy receiving magnetic pole winding r2 drops to zero, this operating mode ends. At this time, the current is positively commutated to the third freewheeling diode D a in the current positive double-winding magnetic integrated passive resonant circuit and turns off under the condition of ZCS.

[0067] Operating mode 6: As Figure 27 shown, the harmonic suppression inductor current i L flows through the first freewheeling diode D1 for freewheeling, and the current through the double-winding magnetic core mutual inductance element remains 0. The voltage of the first resonant cavity energy interaction capacitor C r1 remains at 0. When the first high-frequency modulation switch tube S1 conducts, this operating mode ends.

[0068] As can be seen from the above description, the present invention proposes a double-winding magnetic core resonant high-frequency soft-switching DC / AC converter that can greatly reduce the switching loss of the high-frequency modulation power switch tube of the DC / AC converter. This converter has the following advantages:

[0069] (1) The high-frequency modulation power switch tube in the proposed topology can achieve soft switching, reduce the switching loss, improve the overall efficiency of the converter, and can limit the influence of electromagnetic interference;

[0070] (2) The power switch tube of the proposed topology can operate at a high switching frequency, which helps to reduce the volume of the harmonic suppression shaping element, and only a small number of components can be used to achieve soft switching, which is extremely helpful for improving the power density of the system;

[0071] (3) The realization of soft switching does not require additional switches for assistance, which will greatly simplify the logic of the control circuit.

[0072] (4) The main power freewheeling diode of this topology turns off under the conditions of ZV and ZCS, and the freewheeling diode of the passive resonant circuit turns off under the condition of ZCS, which avoids the generation of the reverse recovery current of the diode, so there is no reverse recovery problem.

[0073] (5) In the present invention, in each group of double-winding magnetic core mutual inductance elements, the inductance values of the primary side and the secondary side are different, so the number of turns wound is different, thus generating a turns ratio. The turns ratio n is defined as the ratio of the number of turns of the secondary side to the primary side, and the turns ratio n of the two groups of double-winding magnetic core mutual inductance elements is set to be the same; due to the existence of the turns ratio between the energy injection side winding and the energy reception side winding of the double-winding magnetic core type mutual inductance element, different n will result in different amplitudes of stress reduction. By selecting an appropriate turns ratio in this topology, such as when n > 1, the voltage and current stresses of the switching tube can be reduced, which is beneficial to the cost control of the converter.

[0074] In the embodiments of this application, the "first", "second", etc. in the names such as "the first" and "the second" are only used as name identifiers and do not represent their importance rankings.

[0075] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter, characterized in that, It includes a main power circuit with a non-bridge-arm direct-through dual-channel architecture, a positive-current dual-winding magnetically integrated passive resonant circuit, a negative-current dual-winding magnetically integrated passive resonant circuit, a dynamic potential equalization circuit, and a harmonic suppression and shaping circuit; Among them, the main power circuit of the bridge-arm-free direct-through dual-channel architecture is used to suppress the harmonic currents i of the positive and negative harmonic suppression inductors, L provide an appropriate main power transmission path and perform high-frequency chopping on the input voltage; the main power circuit of the bridge-arm-free direct-through dual-channel architecture includes a positive harmonic suppression inductor current transmission path and a negative harmonic suppression inductor current transmission path. The positive harmonic suppression inductor current transmission path includes a first high-frequency modulation switch tube S1 and a first current commutation power-frequency modulation switch tube Q L1 , and a first freewheeling diode D1; the negative harmonic suppression inductor current transmission path includes a second high-frequency modulation switch tube S2 and a second current commutation power-frequency modulation switch tube Q L2 and a second freewheeling diode D2; The positive-current dual-winding magnetically integrated passive resonant circuit is connected to the main power circuit with a non-bridge-arm direct-through dual-channel architecture and is used to create soft-switching conditions for the first high-frequency modulation switch tube S1 during high-frequency switching operations, thereby reducing the switching losses and current-voltage stresses of the high-frequency switch tube; The negative-current dual-winding magnetically integrated passive resonant circuit is connected to the main power circuit with a non-bridge-arm direct-through dual-channel architecture and is used to create soft-switching conditions for the second high-frequency modulation switch tube S2 during high-frequency switching operations, thereby reducing the switching losses and current-voltage stresses of the high-frequency switch tube; The dynamic potential equalization circuit is connected to the harmonic suppression and shaping circuit and is used for the dynamic regulation of the potential at the harmonic suppression capacitor end, enabling the harmonic suppression and shaping circuit to correctly output a voltage in the appropriate direction; The harmonic suppression and shaping circuit is connected to the main power circuit with a non-bridge-arm direct-through dual-channel architecture and is used to rectify the output voltage waveform and suppress the generation of high-frequency harmonics.

2. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to claim 1, characterized in that: The source of the first high-frequency modulation switch tube S1 is connected to the drain of the first current-commutating power-frequency modulation switch tube Q L1 and the cathode of the first freewheeling diode D1. The anode of the first freewheeling diode D1 is connected to the negative pole of the input power supply V in , jointly forming a forward harmonic suppression inductive current transmission path and performing high-frequency chopping on the input voltage; the drain of the second high-frequency modulation switch tube S2 is connected to the source of the second current-commutating power-frequency modulation switch tube Q L2 and the anode of the second freewheeling diode D2. The cathode of the second freewheeling diode D2 is connected to the positive pole of the input power supply V in , jointly forming a negative harmonic suppression inductive current transmission path and performing high-frequency chopping on the input voltage, and the drain of the second current-commutating power-frequency modulation switch tube Q L2 is connected to the source of the first current-commutating power-frequency modulation switch tube Q L1 .

3. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to claim 1, wherein: The forward current double-winding magnetic integration passive resonant circuit includes a first energy injection magnetic pole winding inductor L r1 、a first energy receiving magnetic pole winding inductor L r2 、a first resonant cavity energy interaction capacitor C r1 and a third freewheeling diode D a . Among them, the first energy injection magnetic pole winding inductor L r1 and the first energy receiving magnetic pole winding inductor L r2 constitute a group of double-winding magnetic core mutual inductance elements. The first energy injection magnetic pole winding inductor L r1 serves as the primary side, and the first energy receiving magnetic pole winding inductor L r2 serves as the secondary side. When the double-winding magnetic core resonates with the first resonant cavity energy interaction capacitor C r1 , the energy of the inductor and the capacitor will perform reactive power exchange. The magnetic pole synchronous terminal of the first energy injection magnetic pole winding inductor L r1 and the non-magnetic pole synchronous terminal of the first energy receiving magnetic pole winding inductor L r2 are connected to the positive pole of the input power supply V in . The non-magnetic pole synchronous terminal of the first energy injection magnetic pole winding inductor L r1 is connected to the drain of the first high-frequency modulation switch tube S1. The magnetic pole synchronous terminal of the first energy receiving magnetic pole winding inductor L r2 is connected to the cathode of the third freewheeling diode D a . The anode of the third freewheeling diode D a is connected to the cathode of the first freewheeling diode D1, the source of the first high-frequency modulation switch tube S1, and the drain of the first current commutation power frequency modulation switch tube Q L1 , and is connected to one end of the first resonant cavity energy interaction capacitor C r1 . The other end of the first resonant cavity energy interaction capacitor C r1 is connected to the negative pole of the input power supply V in .

4. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to claim 1, characterized in that: The current negative double-winding magnetic integration passive resonant circuit includes a second energy injection magnetic pole winding inductor L r3 、a second energy receiving magnetic pole winding inductor L r4 、a second resonant cavity energy interaction capacitor C r2 and a fourth freewheeling diode D b ; wherein, the second energy injection magnetic pole winding inductor L r3 and the second energy receiving magnetic pole winding inductor L r4 constitute a set of double-winding magnetic core mutual inductance elements, with the second energy injection magnetic pole winding inductor L r3 as the primary side and the second energy receiving magnetic pole winding inductor L r4 as the secondary side; when the double-winding magnetic core resonates with the second resonant cavity energy interaction capacitor C r2 , reactive energy exchange occurs between the inductor and the capacitor; among them, the non-pole synchronous terminal of the second energy injection magnetic pole winding inductor L r3 and the anode of the fourth freewheeling diode D b are connected to the negative pole of the input power supply V in , the pole synchronous terminal of the second energy injection magnetic pole winding inductor L r3 is connected to the source of the second high-frequency modulation switch tube S2, the pole synchronous terminal of the second energy receiving magnetic pole winding inductor L r4 is connected to the cathode of the fourth freewheeling diode D b , the non-pole synchronous terminal of the second energy receiving magnetic pole winding inductor L r4 is connected to the anode of the second freewheeling diode D2, the drain of the second high-frequency modulation switch tube S2, and the source of the second current commutation power frequency modulation switch tube Q L2 and is connected to one end of the second resonant cavity energy interaction capacitor C r2 , and the other end of the second resonant cavity energy interaction capacitor C r2 is connected to the positive pole of the input power supply V in .

5. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to claim 1, wherein: The dynamic potential equalization circuit includes a first dynamic potential regulating power frequency power switch tube Q1 and a second dynamic potential regulating power frequency power switch tube Q2. Among them, the source of the first dynamic potential regulating power frequency power switch tube Q1 is connected to the negative pole of the input power supply V in and the drain of the first dynamic potential regulating power frequency power switch tube Q1 is connected to the source of the second dynamic potential regulating power frequency power switch tube Q2 and grounded, and the drain of the second dynamic potential regulating power frequency power switch tube Q2 is connected to the positive pole of the input power supply V in .

6. A dual-winding magnetic core resonant high-frequency soft-switching DC / AC converter according to claim 5, characterized in that: The harmonic suppression and shaping circuit includes a harmonic suppression inductor L f and a harmonic suppression capacitor C f . Among them, one end of the harmonic suppression inductor L f is connected to the drain of the second current commutation power frequency modulation switch tube Q L2 and the source of the first current commutation power frequency modulation switch tube Q L1 . The other end of the harmonic suppression inductor L f is connected to one end of the output harmonic suppression capacitor C f . The other end of the harmonic suppression capacitor C f is connected to the drain of the first dynamic potential regulation power frequency switch tube Q1 and the source of the second dynamic potential regulation power frequency switch tube Q2 and is grounded; the voltage across the two ends of the harmonic suppression capacitor C f is the output voltage V O .

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