Large-transformation-ratio induction transformer hybrid converter

Abstract

The invention belongs to the technical field of power electronics, and relates to a large-transformation-ratio induction transformer hybrid converter, which comprises a four-stage special-phase power supply unit PS, an energy-storage capacitor is used for realizing the equalization of input voltage among all stages of each power supply unit, and the voltage stress of each switch tube is reduced; the four-stage special-phase power supply unit PS is electrically connected with the four-stage common-phase power supply units P1-P6 and the four-stage final-phase power supply unit PF respectively, the four-stage special-phase power supply unit PS, the four-stage common-phase power supply units P1-P6 and the four-stage final-phase power supply unit PF are electrically connected with the input end Vin of the converter respectively, and the four-stage final-phase power supply unit PF is electrically connected with the output end Vout of the converter. Therefore, on the basis of realizing the high conversion ratio of 48V-0.75 V, the driving waveform duty ratio is expanded, the inductive current ripple is reduced, and the high transformation ratio requirement is met.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics and relates to a large-ratio inductor transformer hybrid converter. Background Art

[0002] As core facilities for processing and storing large amounts of data, data centers bear the important responsibility of providing a large number of cloud computing services. With the ever-increasing business demands, the number of servers has increased dramatically and their scale has expanded, placing higher demands on the power supply of data centers and posing enormous challenges. Compared to a 12V bus, the 48V bus not only significantly reduces the conduction losses on the bus, but also greatly improves the conversion efficiency of the front-end AC-DC, simplifies the power conversion of the entire power supply chain, and has higher energy efficiency. The 48V bus brings three major technical challenges to the design of the subsequent voltage regulator module (VRM): high step-down ratio, low voltage and high current, and ultra-fast dynamic response.

[0003] However, the traditional use of a multi-phase buck converter to complete the conversion task from 12V to approximately 0.75V has large overall losses and the problem of uneven current between the phases of the multi-phase buck converter.

[0004] Therefore, a converter with direct voltage conversion from 48V to 0.75V, capable of achieving large current output of more than 1000A, and taking into account excellent performance such as high power density, high efficiency, and low device stress is needed to solve the above technical problems. Summary of the Invention

[0005] The technical solution adopted by the present invention to solve the technical problem is: a large transformation ratio inductor transformer hybrid converter, comprising:

[0006] A four-stage special phase power supply unit PS uses energy storage capacitors to evenly distribute the input voltage among each power supply unit, reducing the voltage stress of each switch tube;

[0007] Six four-level common phase power supply units P1 to P6 and one four-level final phase power supply unit PF are used to reduce the equivalent inductance of each power supply unit during dynamic load changes, and reduce the transformer volume of the common phase power supply unit through magnetic flux cancellation;

[0008] The four-level special phase power supply unit PS, the four-level common phase power supply units P1 to P6, and the four-level final phase power supply unit PF are each equipped with three energy storage capacitors. The energy storage capacitors are used to balance the current between each level of each power supply unit to keep the steady-state average voltage constant.

[0009] The four-level special phase power supply unit PS is electrically connected to the four-level common phase power supply units P1~P6 and the four-level last phase power supply unit PF respectively. The four-level special phase power supply unit PS, the four-level common phase power supply units P1~P6, and the four-level last phase power supply unit PF are all electrically connected to the input terminal Vin of the converter respectively, and the four-level last phase power supply unit PF is electrically connected to the output terminal Vout of the converter.

[0010] Preferably, the four-level special phase power supply unit PS includes: switch tubes S11, S21, S31, S41, S12, S22, S32, S42, energy storage capacitors Ct11, Ct21, Ct31, special phase inductors L1, L2, L3, L4; the circuit connection method of the four-level special phase power supply unit PS is: one end of the switch tube S11 is connected to the input terminal Vin of the converter, the other end of the switch tube S11 is connected to one end of the switch tube S21 and one end of the energy storage capacitor Ct11, the other end of the energy storage capacitor Ct11 is connected to one end of the switch tube S12 and one end of the special phase inductor L1, and the other end of the switch tube S12 is grounded The other end of the switch tube S21 is connected to one end of the switch tube S31 and one end of the energy storage capacitor Ct21, the other end of the energy storage capacitor Ct21 is connected to one end of the switch tube S22 and one end of the special phase inductor L2, and the other end of the switch tube S22 is grounded; the other end of the switch tube S31 is connected to one end of the switch tube S41 and one end of the energy storage capacitor Ct31, the other end of the energy storage capacitor Ct31 is connected to one end of the switch tube S32 and one end of the special phase inductor L3, and the other end of the switch tube S32 is grounded; the other end of the switch tube S41 is connected to one end of the low-side switch tube S42 and one end of the special phase inductor L4, and the other end of the switch tube S42 is grounded.

[0011] More preferably, the four-level common phase power supply units P1 to P6 include: switching tubes S1x, S2x, S3x, S4x, switching tubes S1y, S2y, S3y, S4y, energy storage capacitors Ct1z, Ct2z, Ct3z and common phase transformers Tr1w, Tr2w, Tr3w, Tr4w, where x is 3, 5, 7, 9, 11, 13, z is 2, 3, 4, 5, 6, 7 respectively, y=x+1, w=z-1;

[0012] The circuit connection mode of the four-level common phase power supply units P1 to P6 is as follows: one end of the switch tube S1x is connected to the input terminal Vin of the converter, the other end of the switch tube S1x is connected to one end of the switch tube S2x and one end of the energy storage capacitor Ct1z, the other end of the energy storage capacitor Ct1z is connected to one end of the switch tube S1y and one end of the primary side of the common phase transformer Tr1w, the other end of the switch tube S1y is grounded, and the other end of the primary side of the common phase transformer Tr1w is connected to the output terminal Vout; the other end of the switch tube S2x is connected to one end of the switch tube S3x and one end of the energy storage capacitor Ct2z, and the other end of the energy storage capacitor Ct2z is connected to one end of the switch tube S2y and the primary side of the common phase transformer Tr2w. One end of the switch tube S22 is grounded, and the other end of the primary side of the common-phase transformer Tr2w is connected to the output terminal Vout; the other end of the switch tube S3x is connected to one end of the switch tube S4x and one end of the energy storage capacitor Ct3z, the other end of the energy storage capacitor Ct3z is connected to one end of the switch tube S3y and one end of the primary side of the common-phase transformer Tr3w, the other end of the switch tube S32 is grounded, and the other end of the primary side of the common-phase transformer Tr3w is connected to the output terminal Vout; the other end of the switch tube S4x is connected to one end of the switch tube S4y and one end of the primary side of the common-phase transformer Tr4w, the other end of the switch tube S4y is grounded, and the other end of the primary side of the common-phase transformer Tr4w is connected to the output terminal Vout;

[0013] The end of the special phase inductor Ln not connected to the switching tube is connected to one end of the secondary side of the normal phase transformer Trn1, where n=1, 2, 3, 4. The other end of the secondary side of the normal phase transformer Trn1 is connected in series with the secondary sides of the normal phase transformer Trn2, the secondary sides of the normal phase transformer Trn3, the secondary sides of the normal phase transformer Trn4, and the secondary sides of the normal phase transformer Trn5, and then connected to one end of the secondary side of the normal phase transformer Trn6.

[0014] More preferably, the four-stage final phase power supply unit PF includes: switch tubes S115, S215, S315, S415, switch tubes S116, S216, S316, S416, energy storage capacitors Ct18, Ct28, Ct38, and common phase transformers Tr17, Tr27, Tr37, Tr47;

[0015] The circuit connection method of the four-stage final phase power supply unit PF is as follows: one end of the switch tube S115 is connected to the input terminal Vin of the converter, the other end of the switch tube S115 is connected to one end of the switch tube S215 and one end of the energy storage capacitor Ct18, the other end of the energy storage capacitor Ct18 is connected to one end of the switch tube S116 and one end of the primary side of the common phase transformer Tr17, the other end of the switch tube S116 is grounded, and the other end of the primary side of the common phase transformer Tr17 is connected to the output terminal Vout; the other end of the switch tube S215 is connected to one end of the switch tube S315 and one end of the energy storage capacitor Ct28, and the other end of the energy storage capacitor Ct28 is connected to one end of the switch tube S216 and one end of the primary side of the common phase transformer Tr27. , the other end of the switch tube S22 is grounded, and the other end of the primary side of the common-phase transformer Tr27 is connected to the output terminal Vout; the other end of the switch tube S315 is connected to one end of the switch tube S415 and one end of the energy storage capacitor Ct38, the other end of the energy storage capacitor Ct38 is connected to one end of the switch tube S316 and one end of the primary side of the common-phase transformer Tr37, the other end of the switch tube S32 is grounded, and the other end of the primary side of the common-phase transformer Tr37 is connected to the output terminal Vout; the other end of the switch tube S415 is connected to one end of the switch tube S416 and one end of the primary side of the common-phase transformer Tr47, the other end of the switch tube S416 is grounded, and the other end of the primary side of the common-phase transformer Tr47 is connected to the output terminal Vout;

[0016] The other end of the secondary side of the common phase transformer Trn6 is connected to one end of the common phase transformer Trn7 , and the other end of the common phase transformer Trn7 is connected to the output end Vout.

[0017] More preferably, the driving waveforms of the switches S11, S31, S29, and S49 are the same; the driving waveforms of the switches S12, S32, S210, and S410 are the same; the driving waveforms of the switches S11 and S12 are complementary; and the duty cycle D of the switches during operation is related to the gain of the converter.

[0018] The driving waveforms of switches S13, S33, S211, and S411 are the same. The driving waveforms of switches S14, S34, S212, and S412 are the same. The driving waveforms of switches S13 and S14 are complementary. The driving waveform of switch S13 lags behind the driving waveform of switch S11 by 45°.

[0019] The driving waveforms of switches S15, S35, S213, and S413 are the same. The driving waveforms of switches S16, S36, S214, and S414 are the same. The driving waveforms of switches S15 and S16 are complementary. The driving waveform of switch S15 lags behind the driving waveform of switch S11 by 90°.

[0020] The driving waveforms of switches S17, S37, S215, and S415 are the same. The driving waveforms of switches S18, S38, S216, and S416 are the same. The driving waveforms of switches S17 and S18 are complementary. The driving waveform of switch S17 lags behind the driving waveform of switch S11 by 135°.

[0021] The driving waveforms of switches S19, S39, S21, and S41 are the same. The driving waveforms of switches S110, S310, S22, and S42 are the same. The driving waveforms of switches S19 and S110 are complementary. The driving waveform of switch S19 lags behind the driving waveform of switch S11 by 180°.

[0022] The driving waveforms of switches S111, S311, S23, and S43 are the same. The driving waveforms of switches S112, S312, S24, and S44 are the same. The driving waveforms of switches S111 and S112 are complementary. The driving waveform of switch S111 lags behind the driving waveform of switch S11 by 225°.

[0023] The driving waveforms of switches S113, S313, S25, and S45 are the same. The driving waveforms of switches S114, S314, S26, and S46 are the same. The driving waveforms of switches S113 and S114 are complementary, and the driving waveform of switch S113 lags behind the driving waveform of switch S11 by 270°.

[0024] The driving waveforms of switches S115, S315, S27, and S47 are the same. The driving waveforms of switches S116, S316, S28, and S48 are the same. The driving waveforms of switches S115 and S116 are complementary. The driving waveform of switch S115 lags behind the driving waveform of switch S11 by 315°.

[0025] Preferably, the switching tubes in the converter are all gallium nitride switching tubes.

[0026] Preferably, a driving waveform of the switch tube in the converter is provided with a dead time.

[0027] Preferably, the duty cycle D of the driving waveform of the switching tube in the converter when it is working is less than 0.125.

[0028] Preferably, the gain of the converter is determined by the duty cycle of the driving waveform, and the calculation formula is:

[0029]

[0030] In formula (1), V in Indicates the input voltage, V out represents the output voltage, and D represents the duty cycle of the driving waveform.

[0031] Preferably, the total ripple value of the inductor current of the converter is determined by the duty cycle, the switching period, the special phase inductance, the common phase transformer excitation inductance, the input voltage, and the output voltage, and is calculated as follows:

[0032]

[0033] In formula (2), V in Indicates the input voltage, V out represents the output voltage, D represents the duty cycle of the driving waveform, T represents the switching period, L represents the special phase inductance value, L m Indicates the excitation inductance of the common phase transformer, ΔI Lsum Indicates the total ripple value of the inductor current.

[0034] Preferably, the converter's special phase inductors L1-L4 and common phase transformers Tr1w, Tr2w, Tr3w, Tr4w (where w is a positive integer from 1 to 7) form an inductor-transformer hybrid magnetic coupling structure.

[0035] Preferably, the topology of the converter has an automatic current balancing mechanism, and the converter does not require an additional inductor current balancing circuit, thereby simplifying the controller design.

[0036] The beneficial effects of the present invention are:

[0037] 1. Based on the realization of a high conversion ratio of 48V-0.75V, the present invention expands the duty cycle of the driving waveform, reduces the inductor current ripple, and meets the high conversion ratio requirements.

[0038] 2. The present invention reduces the core volume of ordinary phase transformers and meets high power density requirements.

[0039] 3. The present invention eliminates the need for intermediate bus capacitors, thus meeting power density requirements.

[0040] 4. The present invention reduces the current ripple of the special phase inductor, reduces the loss, and meets the requirements of high efficiency.

[0041] 5. The present invention can achieve a high current output of 1200A, meeting the demand for high current power supply.

[0042] 6. The automatic current balancing mechanism of the present invention does not require an additional inductor current balancing circuit for the converter, thereby simplifying the design of the controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a circuit diagram of a large-ratio inductor-transformer hybrid converter of the present invention;

[0044] Figure 2 It is a circuit timing diagram of the present invention;

[0045] Figure 3 is a circuit equivalent circuit diagram of the working mode of the present invention;

[0046] Figure 4 is an equivalent circuit diagram of the working mode 2 circuit of the present invention;

[0047] Figure 5 is the working mode three-circuit equivalent circuit diagram of the present invention;

[0048] Figure 6 is the equivalent circuit diagram of the four-circuit working mode of the present invention;

[0049] Figure 7 This is a simulation waveform diagram of the inductor current of each phase during dynamic load reduction of the present invention;

[0050] Figure 8 This is a simulated waveform diagram of output voltage and current during dynamic load reduction of the present invention;

[0051] Figure 9 This is a simulation waveform diagram of the inductor current of each phase during dynamic loading of the present invention;

[0052] Figure 10 This is a simulation waveform diagram of the output voltage and current during dynamic loading of the present invention. DETAILED DESCRIPTION

[0053] The following will provide a clear and complete description of the relevant technologies in the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0054] refer to Figures 1 to 10In this embodiment, a large-ratio inductor-transformer hybrid converter includes: a four-level special phase power supply unit PS, six four-level common phase power supply units P1-P6, a four-level final phase power supply unit PN, an input terminal Vin, an output terminal Vout, and a ground terminal; the four-level special phase power supply unit PS includes four high-side switching tubes S11, S21, S31, and S41, four low-side switching tubes S12, S22, S32, and S42, energy storage capacitors Ct11, Ct21, and Ct31, and special phase inductors L1, L2, L3, and L4; one end of the high-side switching tube S11 is connected to the input terminal Vin, and the other end of the high-side switching tube S11 is simultaneously connected to one end of the high-side switching tube S21 and one end of the energy storage capacitor Ct11; the other end of the energy storage capacitor Ct11 is simultaneously connected to one end of the low-side switching tube S12, One end of the special phase inductor L1; the other end of the low-side switch tube S12 is grounded; the other end of the high-side switch tube S21 is simultaneously connected to one end of the high-side switch tube S31 and one end of the energy storage capacitor Ct21, and the other end of the energy storage capacitor Ct21 is simultaneously connected to one end of the low-side switch tube S22 and one end of the special phase inductor L2; the other end of the low-side switch tube S22 is grounded; the other end of the high-side switch tube S31 is simultaneously connected to one end of the high-side switch tube S41 and one end of the energy storage capacitor Ct31, and the other end of the energy storage capacitor Ct31 is simultaneously connected to one end of the low-side switch tube S32 and one end of the special phase inductor L3; the other end of the low-side switch tube S32 is grounded; the other end of the high-side switch tube S41 is simultaneously connected to one end of the low-side switch tube S42 and one end of the special phase inductor L4; the other end of the low-side switch tube S42 is grounded.Each of the four-level common phase power supply units P1-P6 includes four high-side switch tubes S1x, S2x, S3x, S4x, four low-side switch tubes S1y, S2y, S3y, S4y, energy storage capacitors Ct1z, Ct2z, Ct3z and common phase transformers Tr1w, Tr2w, Tr3w, Tr4w (where x is 3, 5, 7, 9, 11, 13, z is 2, 3, 4, 5, 6, 7 respectively, y = x + 1, w = z-1); high-side switch One end of the transistor S1x is connected to the input terminal Vin, and the other end of the high-side switch transistor S1x is simultaneously connected to one end of the high-side switch transistor S2x and one end of the energy storage capacitor Ct1z; the other end of the energy storage capacitor Ct1z is simultaneously connected to one end of the low-side switch transistor S1y and one end of the primary side of the common phase transformer Tr1w; the other end of the low-side switch transistor S1y is grounded; the other end of the primary side of the common phase transformer Tr1w is connected to the output terminal Vout; the other end of the high-side switch transistor S2x is simultaneously connected to the high-side One end of the switching tube S3x and one end of the energy storage capacitor Ct2z, and the other end of the energy storage capacitor Ct2z are simultaneously connected to one end of the low-side switching tube S2y and one end of the primary side of the common-phase transformer Tr2w; the other end of the low-side switching tube S22 is grounded; the other end of the primary side of the common-phase transformer Tr2w is connected to the output terminal Vout; the other end of the high-side switching tube S3x is simultaneously connected to one end of the high-side switching tube S4x and one end of the energy storage capacitor Ct3z, and the other end of the energy storage capacitor Ct3z is simultaneously connected to one end of the low-side switching tube S3y and one end of the primary side of the common-phase transformer Tr3w; the other end of the low-side switching tube S32 is grounded; the other end of the primary side of the common-phase transformer Tr3w is connected to the output terminal Vout; the other end of the high-side switching tube S4x is simultaneously connected to one end of the low-side switching tube S4y and one end of the primary side of the common-phase transformer Tr4w; the other end of the low-side switching tube S4y is grounded; the other end of the primary side of the common-phase transformer Tr4w is connected to the output terminal Vout.The four-stage final phase power supply unit PN includes four high-side switching tubes S115, S215, S315, and S415, four low-side switching tubes S116, S216, S316, and S416, energy storage capacitors Ct18, Ct28, and Ct38, and common phase transformers Tr17, Tr27, Tr37, and Tr47; one end of the high-side switching tube S115 is connected to the input terminal Vin, and the other end of the high-side switching tube S115 is simultaneously connected to one end of the high-side switching tube S215 and one end of the energy storage capacitor Ct18; the other end of the energy storage capacitor Ct18 is simultaneously connected to one end of the low-side switching tube S116 and one end of the primary side of the common phase transformer Tr17; the other end of the low-side switching tube S116 is grounded; the other end of the primary side of the common phase transformer Tr17 is connected to the output terminal Vout; the other end of the high-side switching tube S215 is simultaneously connected to one end of the high-side switching tube S315 and one end of the energy storage capacitor Ct28, and the energy storage capacitor Ct18 is connected to the output terminal Vout. The other end of the energy storage capacitor Ct28 is simultaneously connected to one end of the low-side switch tube S216 and one end of the primary side of the common-phase transformer Tr27; the other end of the low-side switch tube S22 is grounded; the other end of the primary side of the common-phase transformer Tr27 is connected to the output terminal Vout; the other end of the high-side switch tube S315 is simultaneously connected to one end of the high-side switch tube S415 and one end of the energy storage capacitor Ct38, and the other end of the energy storage capacitor Ct38 is simultaneously connected to one end of the low-side switch tube S316 and one end of the primary side of the common-phase transformer Tr37; the other end of the low-side switch tube S32 is grounded; the other end of the primary side of the common-phase transformer Tr37 is connected to the output terminal Vout; the other end of the high-side switch tube S415 is simultaneously connected to one end of the low-side switch tube S416 and one end of the primary side of the common-phase transformer Tr47; the other end of the low-side switch tube S416 is grounded; the other end of the primary side of the common-phase transformer Tr47 is connected to the output terminal Vout. The ends of the four special phase inductors Ln (n=1, 2, 3, 4) not connected to the low-side switching tube are respectively connected to one end of the secondary side of the common phase transformer Trn1, the other end of the secondary side of the common phase transformer Trn1 is connected to one end of the secondary side of the common phase transformer Trn2, the other end of the secondary side of the common phase transformer Trn2 is connected to one end of the secondary side of the common phase transformer Trn3, the other end of the secondary side of the common phase transformer Trn3 is connected to one end of the secondary side of the common phase transformer Trn4, the other end of the secondary side of the common phase transformer Trn4 is connected to one end of the secondary side of the common phase transformer Trn5, the other end of the secondary side of the common phase transformer Trn5 is connected to one end of the secondary side of the common phase transformer Trn6, the other end of the secondary side of the common phase transformer Trn6 is connected to one end of the secondary side of the common phase transformer Trn7, and the other end of the secondary side of the common phase transformer Trn7 is connected to the output terminal Vout; the primary and secondary sides of the above-mentioned common phase transformers need to be connected in a reverse coupling relationship.

[0055] Figure 2 for Figure 1The circuit timing diagram of the high-ratio inductor transformer hybrid converter shows the drive waveforms G1 and G2 of the switching tubes and the current I on the special phase inductor L1. L1 , the primary current I of the normal phase transformer Tr11 Tr11 The primary current waveforms of the common phase transformers Tr12, Tr13, Tr14, Tr15, Tr16, and Tr17 lag behind I Tr11 The angles are: 45°, 90°, 135°, 180°, 225°, 270°, 315°; the current waveforms on the special phase inductors L2, L3, and L4 are related to I L1The primary current waveforms of the common-phase transformers Tr21, Tr22, Tr23, Tr25, Tr26, and Tr27 are respectively the same as the primary current waveforms of the common-phase transformers Tr15, Tr16, Tr17, Tr11, Tr12, and Tr13. The primary current waveform of the common-phase transformer Tr24 lags the primary current waveform of the common-phase transformer Tr14 by 180°. The waveform of the common-phase transformer Tr1a is the same as that of Tr3a, and the waveform of the common-phase transformer Tr2a is the same as that of Tr4a (where a is a positive integer from 1 to 7). The control terminals of the switching tubes are respectively used to input drive signals. When the drive signal G1 is at a high level, the switching tubes S11, S31, S29, and S49 are turned on. When the drive signal G1 is at a low level, the switching tubes S11, S31, S29, and S49 are turned off. When the drive signal G2 is at a high level, the switching tubes S13, S29, and S49 are turned off. 33, the switch tube S211, and the switch tube S411 are turned on; when the drive signal G2 is at a low level, the switch tubes S13, S33, S211, and S411 are turned off; the drive signals not shown in the figure include the drive signals G3, G4, G5, G6, G7, and G8, which lag the drive signal G2 by 45°, 90°, 135°, 180°, 225°, and 270°, respectively; when the drive signal G3 is at a high level, the switch tubes S15, S35, S213, and S413 are turned on; when the drive signal G3 is at a low level, the switch tubes S15, S35, S213, and S413 are turned on. 35, the switch tube S213 and the switch tube S413 are turned off; when the drive signal G4 is at a high level, the switch tubes S17, the switch tube S37, the switch tube S215 and the switch tube S415 are turned on; when the drive signal G4 is at a low level, the switch tubes S17, the switch tube S37, the switch tube S215 and the switch tube S415 are turned off; when the drive signal G5 is at a high level, the switch tubes S19, the switch tube S39, the switch tube S21 and the switch tube S41 are turned on; when the drive signal G5 is at a low level, the switch tubes S19, the switch tube S39, the switch tube S21 and the switch tube S41 are turned off; when the drive signal G6 is at a high level, the switch tubes S111, the switch tube S311, the switch tube S23, The switch S43 is turned on. When the drive signal G6 is at a low level, the switch tubes S111, S311, S23, and S43 are turned off. When the drive signal G7 is at a high level, the switch tubes S113, S313, S25, and S45 are turned on. When the drive signal G7 is at a low level, the switch tubes S113, S313, S25, and S45 are turned off. When the drive signal G8 is at a high level, the switch tubes S115, S315, S27, and S47 are turned on. When the drive signal G8 is at a low level, the switch tubes S115, S315, S27, and S47 are turned off.The switch transistors S12, S32, S210, and S410 work in complement with the switch transistors S11, S31, S29, and S49, respectively. The switch transistors S14, S34, S212, and S412 work in complement with the switch transistors S13, S33, S211, and S411, respectively. The switch transistors S16, S36, S214, and S414 work in complement with the switch transistors S15, S35, S213, and S413, respectively. The switch transistors S18, S38, S216, and S416 work in complement with the switch transistors S17, S37, S215, and S415, respectively. Switches S110, S310, S22, and S42 complement each other with switches S19, S39, S21, and S41, respectively. Switches S112, S312, S24, and S44 complement each other with switches S111, S311, S23, and S43, respectively. Switches S114, S314, S26, and S46 complement each other with switches S113, S313, S25, and S45, respectively. Switches S116, S316, S28, and S48 complement each other with switches S115, S315, S27, and S47, respectively. Dead time is provided to prevent commonality among the complementary switches.

[0056] Figure 3 for Figure 1 Equivalent circuit diagram when the drive signal G1 is high and the drive signals G2-G8 are all low. The input terminal Vin charges the energy storage capacitor Ct11 and the special phase inductor L1. The voltage on the energy storage capacitor Ct11 is stabilized at 3Vin / 4, and the common phase transformers Tr11-Tr17 discharge to the output terminal; the energy storage capacitor Ct25 and the energy storage capacitor Ct15 are connected in series, and the equivalent voltage Vin / 4 charges the primary side of the common phase transformer Tr24. The common phase transformers Tr21, Tr22, Tr23, Tr25, Tr26, and Tr27 discharge to the output terminal; the energy storage capacitor Ct 21 is connected in series with the energy storage capacitor Ct31, with an equivalent voltage of Vin / 4, charging the special phase inductor L3, and discharging the common phase transformers Tr31-Tr37 to the output end; the energy storage capacitor Ct35, with an equivalent voltage of Vin / 4, charges the primary side of the common phase transformer Tr44, and discharges the common phase transformers Tr41, Tr42, Tr43, Tr45, Tr46, and Tr47 to the output end; the output end Vout voltage is 0.75V, achieving a 48V-0.75V voltage conversion. Ignoring the influence of dead time, in steady state, Equation (3) can be derived:

[0057]

[0058] Among them, V in is the input voltage, V o is the output voltage, L is the special phase inductance value, L m is the excitation inductance of the common phase transformer.

[0059] After finishing, we can get:

[0060]

[0061] Where T is the switching period.

[0062] For the total inductor current ripple value ΔI Lsum , as shown in formula (5):

[0063]

[0064] Figure 4 for Figure 1 Equivalent circuit diagram when drive signals G1-G8 are all low. Special phase inductors L1-L4 and common phase transformers Tr11-Tr17, Tr21-Tr27, Tr31-Tr37, and Tr41-Tr47 all discharge to the output terminal; the output terminal Vout voltage is 0.75V, achieving a 48V-0.75V voltage conversion. Ignoring the effect of dead time, in steady-state conditions, equation (6) can be derived:

[0065]

[0066] Where j = 1, 2, 3, 4, n = 1, 2, 3, 4, 5, 6, 7.

[0067] After finishing, we can get:

[0068]

[0069] Among them, V in is the input voltage, V o is the output voltage, L is the special phase inductance value, L m is the excitation inductance of the common phase transformer, T off The duration that G1-G8 are all low.

[0070] Figure 5 for Figure 1Equivalent circuit diagram when the drive signal G2 is high and the drive signals G1, G3-G8 are all low. The input terminal Vin charges the energy storage capacitor Ct12 and the primary side of the common phase transformer Tr11. The voltage on the energy storage capacitor Ct12 is stabilized at 3Vin / 4, and the common phase transformers Tr12-Tr17 discharge to the output terminal; the energy storage capacitor Ct26 and the energy storage capacitor Ct16 are connected in series, with an equivalent voltage of Vin / 4, charging the primary side of the common phase transformer Tr25, and the common phase transformers Tr21, Tr22, Tr23, Tr24, Tr26, and Tr27 discharge to the output terminal; the energy storage capacitor C t22 is connected in series with the energy storage capacitor Ct32, with an equivalent voltage of Vin / 4, charging the common phase transformer Tr31, and the common phase transformers Tr32-Tr37 discharge to the output end; the energy storage capacitor Ct36, with an equivalent voltage of Vin / 4, charges the primary side of the common phase transformer Tr45, and the common phase transformers Tr41, Tr42, Tr43, Tr44, Tr46, and Tr47 discharge to the output end; the output end Vout voltage is 0.75V, achieving a 48V-0.75V voltage conversion. Ignoring the influence of dead time, in steady state, equation (8) can be derived:

[0071]

[0072] By rearranging the formula, we can obtain the current ripple value of each special phase inductor and the common phase transformer:

[0073]

[0074] For the total inductor current ripple value ΔI Lsum , as shown in formula (10):

[0075]

[0076] According to the relationship between the total inductor current ripple, it can be found that the total inductor current ripple of mode three is greater than the total inductor current ripple of mode one.

[0077] akin, Figure 1 In the following six operating modes, the operating characteristics are similar to those in mode three, and the relationship between the total inductor current ripple is consistent with that in mode three:

[0078] (1) When the driving signal G2 is at a high level and the driving signals G1, G3-G8 are all at a low level;

[0079] (2) When the driving signal G3 is at a high level and the driving signals G1, G2, G4-G8 are all at a low level;

[0080] (3) When the driving signal G4 is at a high level and the driving signals G1-G3 and G5-G8 are all at a low level;

[0081] (4) When the driving signal G6 is at a high level and the driving signals G1-G5, G7, and G8 are all at a low level;

[0082] (5) When the driving signal G7 is at a high level and the driving signals G1-G6 and G8 are all at a low level;

[0083] (6) When the driving signal G8 is at a high level and the driving signals G1-G7 are all at a low level;

[0084] Figure 6 for Figure 1 Equivalent circuit diagram when the drive signal G5 is high and the drive signals G1-G4, G6-G8 are all low. The input terminal Vin charges the energy storage capacitor Ct15 and the primary side of the common phase transformer Tr14. The voltage on the energy storage capacitor Ct15 is stabilized at 3Vin / 4. The common phase transformers Tr11, Tr12, Tr13, Tr15, Tr16, and Tr17 discharge to the output terminal. The energy storage capacitor Ct21 and the energy storage capacitor Ct11 are connected in series, and the equivalent voltage Vin / 4 charges the special phase inductor L2. The common phase transformers Tr21-Tr27 discharge to the output terminal. The energy storage capacitor Ct 25 is connected in series with the energy storage capacitor Ct35, generating an equivalent voltage of Vin / 4, charging the primary side of the common phase transformer Tr34. The common phase transformers Tr31, Tr32, Tr33, Tr35, Tr36, and Tr37 discharge to the output terminal. The energy storage capacitor Ct31 generates an equivalent voltage of Vin / 4, charging the special phase inductor L4, and the common phase transformers Tr41-Tr47 discharge to the output terminal. The output terminal Vout voltage is 0.75V, achieving a 48V-0.75V voltage conversion. Ignoring the influence of dead time, in steady state, it can be derived that:

[0085]

[0086] Among them, V in is the input voltage, V o is the output voltage, L is the special phase inductance value, L m is the excitation inductance of the common phase transformer.

[0087] After finishing, we can get:

[0088]

[0089] Where T is the switching period.

[0090] For the total inductor current ripple value ΔI Lsum , as shown in formula (5):

[0091]

[0092] It can be seen that Figure 6 The modal four and Figure 3 The conclusion of mode 1 is the same and the working mode is similar.

[0093] Figure 7 Figure 8 The dynamic response simulation waveform of the converter is given when the load current decreases from 1200A to 1000A at a rate of 1000A / μs. It can be seen that the output voltage overshoot is only 13.98mV, about 1.86%.

[0094] Figure 9 Figure 10 The dynamic response simulation waveform of the converter is given when the load current increases from 1000A to 1200A at a rate of 1000A / μs. It can be seen that the output voltage drops by only 27.52mV, about 3.67%.

[0095] The above analysis shows that the current waveforms of the special-phase inductors L1-L4 are consistent and have small ripple. The primary current waveforms of the ordinary-phase transformers have phase differences, and the ripple is greater than that of the special-phase inductors. This hybrid converter can meet the high-current power supply requirements of 1200A from a 48V bus to 0.75V.

[0096] according to Figure 1 From the connection relationship between the primary and secondary sides of the common phase transformer, it can be found that the current on the special phase inductor flows through the secondary side of the common phase transformer, so that the DC component of the magnetic flux generated by the primary current of the transformer and the current on the special phase inductor flowing through the secondary side can cancel each other, leaving only the AC component to cause core saturation. Therefore, the core volume of the common phase transformer can be significantly reduced and core saturation is not easy to occur.

[0097] according to Figure 1 Each of the four-level special phase power supply unit PS, the six four-level normal phase power supply units P1-P6, and the four-level final phase power supply unit PN contains three energy storage capacitors. Their presence balances the current between each power supply unit's stages. Current balance is achieved because the charge of the energy storage capacitors must remain balanced, meaning their steady-state average voltage is constant. For example, if the current in special phase inductor L1 is greater than the current in special phase inductor L2, the voltage across Ct11 and Ct12 will rise, thereby reducing the average voltage at the phase switch node where special phase inductor L1 resides and simultaneously increasing the average voltage at the phase switch node where special phase inductor L2 resides. This reduces the current in special phase inductor L1 and increases the current in special phase inductor L2. Similarly, if there is a current imbalance between any two adjacent stages of the power supply unit, automatic current balancing will be achieved according to this mechanism.

[0098] In summary, the present invention not only achieves a high conversion ratio of 48V-0.75V, but also expands the duty cycle of the driving waveform, reduces the inductor current ripple, and meets the high conversion ratio requirement.

[0099] It should be emphasized that the above are only preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications made to the above embodiments based on the technical essence of the present invention also fall within the scope of protection of the present invention. Other equivalent changes and modifications still fall within the scope of the technical solution of the present invention.

Claims

1. A large transformation ratio inductor transformer hybrid converter, characterized in that: include: A four-stage special phase power supply unit (PS) is used to evenly distribute the input voltage among each power supply unit through energy storage capacitors, reducing the voltage stress of each switch tube; Six four-level common phase power supply units P1 to P6 and one four-level final phase power supply unit PF are used to reduce the equivalent inductance of each power supply unit during dynamic load changes, and reduce the transformer volume of the common phase power supply unit through magnetic flux cancellation; The four-level special phase power supply unit PS, the four-level common phase power supply units P1 to P6, and the four-level final phase power supply unit PF are each provided with three energy storage capacitors, and the energy storage capacitors are used to balance the current between each level of each power supply unit so that the steady-state average voltage is constant; The four-level special phase power supply unit PS is electrically connected to the four-level common phase power supply units P1~P6 and the four-level last phase power supply unit PF respectively. The four-level special phase power supply unit PS, the four-level common phase power supply units P1~P6, and the four-level last phase power supply unit PF are all electrically connected to the input end Vin of the converter respectively, and the four-level last phase power supply unit PF is electrically connected to the output end Vout of the converter.

2. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The four-level special phase power supply unit PS includes: switch tubes S11, S21, S31, S41, S12, S22, S32, S42, energy storage capacitors Ct11, Ct21, Ct31, special phase inductors L1, L2, L3, L4; the circuit connection mode of the four-level special phase power supply unit PS is: one end of the switch tube S11 is connected to the input terminal Vin of the converter, the other end of the switch tube S11 is connected to one end of the switch tube S21 and one end of the energy storage capacitor Ct11, the other end of the energy storage capacitor Ct11 is connected to one end of the switch tube S12 and one end of the special phase inductor L1, and the other end of the switch tube S12 is connected to the input terminal Vin of the converter. The other end of the switch tube S21 is connected to one end of the switch tube S31 and one end of the energy storage capacitor Ct21, the other end of the energy storage capacitor Ct21 is connected to one end of the switch tube S22 and one end of the special phase inductor L2, and the other end of the switch tube S22 is grounded; the other end of the switch tube S31 is connected to one end of the switch tube S41 and one end of the energy storage capacitor Ct31, the other end of the energy storage capacitor Ct31 is connected to one end of the switch tube S32 and one end of the special phase inductor L3, and the other end of the switch tube S32 is grounded; the other end of the switch tube S41 is connected to one end of the switch tube S42 and one end of the special phase inductor L4, and the other end of the switch tube S42 is grounded.

3. The large transformation ratio inductor transformer hybrid converter according to claim 2, characterized in that: The four-level common phase power supply units P1-P6 include: switches S1x, S2x, S3x, S4x, switches S1y, S2y, S3y, S4y, energy storage capacitors Ct1z, Ct2z, Ct3z and common phase transformers Tr1w, Tr2w, Tr3w, Tr4w, where x is 3, 5, 7, 9, 11, 13, z is 2, 3, 4, 5, 6, 7 respectively, y=x+1, w=z-1; The circuit connection mode of the four-level common phase power supply units P1 to P6 is as follows: one end of the switch tube S1x is connected to the input terminal Vin of the converter, the other end of the switch tube S1x is simultaneously connected to one end of the switch tube S2x and one end of the energy storage capacitor Ct1z, the other end of the energy storage capacitor Ct1z is connected to one end of the switch tube S1y and one end of the primary side of the common phase transformer Tr1w, the other end of the switch tube S1y is grounded, and the other end of the primary side of the common phase transformer Tr1w is connected to the output terminal Vout; the other end of the switch tube S2x is connected to one end of the switch tube S3x and one end of the energy storage capacitor Ct2z, the other end of the energy storage capacitor Ct2z is connected to one end of the switch tube S2y and the primary side of the common phase transformer Tr2w one end of the switch tube S22, the other end of the switch tube S22 is grounded, and the other end of the primary side of the common-phase transformer Tr2w is connected to the output terminal Vout; the other end of the switch tube S3x is connected to one end of the switch tube S4x and one end of the energy storage capacitor Ct3z, the other end of the energy storage capacitor Ct3z is connected to one end of the switch tube S3y and one end of the primary side of the common-phase transformer Tr3w, the other end of the switch tube S32 is grounded, and the other end of the primary side of the common-phase transformer Tr3w is connected to the output terminal Vout; the other end of the switch tube S4x is connected to one end of the switch tube S4y and one end of the primary side of the common-phase transformer Tr4w, the other end of the switch tube S4y is grounded, and the other end of the primary side of the common-phase transformer Tr4w is connected to the output terminal Vout; One end of the special phase inductor Ln not connected to the switching tube is respectively connected to one end of the secondary side of the normal phase transformer Trn1, where n=1, 2, 3, 4; the other end of the secondary side of the normal phase transformer Trn1 is connected in series with the secondary side of the normal phase transformer Trn2, the secondary side of the normal phase transformer Trn3, the secondary side of the normal phase transformer Trn4, and the secondary side of the normal phase transformer Trn5, and then connected to one end of the secondary side of the normal phase transformer Trn6.

4. The large transformation ratio inductor transformer hybrid converter according to claim 3, characterized in that: The four-stage final phase power supply unit PF includes: switch tubes S115, S215, S315, S415, switch tubes S116, S216, S316, S416, energy storage capacitors Ct18, Ct28, Ct38, and common phase transformers Tr17, Tr27, Tr37, Tr47; The circuit connection mode of the four-stage final phase power supply unit PF is as follows: one end of the switch tube S115 is connected to the input terminal Vin of the converter, the other end of the switch tube S115 is connected to one end of the switch tube S215 and one end of the energy storage capacitor Ct18, the other end of the energy storage capacitor Ct18 is connected to one end of the switch tube S116 and one end of the primary side of the common phase transformer Tr17, the other end of the switch tube S116 is grounded, and the other end of the primary side of the common phase transformer Tr17 is connected to the output terminal Vout; the other end of the switch tube S215 is connected to one end of the switch tube S315 and one end of the energy storage capacitor Ct28, the other end of the energy storage capacitor Ct28 is connected to one end of the switch tube S216 and one end of the primary side of the common phase transformer Tr27 end, the other end of the switch tube S22 is grounded, and the other end of the primary side of the common-phase transformer Tr27 is connected to the output terminal Vout; the other end of the switch tube S315 is connected to one end of the switch tube S415 and one end of the energy storage capacitor Ct38, the other end of the energy storage capacitor Ct38 is connected to one end of the switch tube S316 and one end of the primary side of the common-phase transformer Tr37, the other end of the switch tube S32 is grounded, and the other end of the primary side of the common-phase transformer Tr37 is connected to the output terminal Vout; the other end of the switch tube S415 is connected to one end of the switch tube S416 and one end of the primary side of the common-phase transformer Tr47, the other end of the switch tube S416 is grounded, and the other end of the primary side of the common-phase transformer Tr47 is connected to the output terminal Vout; The other end of the secondary side of the common phase transformer Trn6 is connected to one end of the common phase transformer Trn7, and the other end of the common phase transformer Trn7 is connected to the output end Vout.

5. The large transformation ratio inductor transformer hybrid converter according to claim 4, characterized in that: The driving waveforms of the switches S11, S31, S29, and S49 are the same; the driving waveforms of the switches S12, S32, S210, and S410 are the same; the driving waveforms of the switches S11 and S12 are complementary. The driving waveforms of the switches S13, S33, S211, and S411 are the same; the driving waveforms of the switches S14, S34, S212, and S412 are the same; the driving waveforms of the switches S13 and S14 are complementary; the driving waveform of the switch S13 lags behind the driving waveform of the switch S11 by 45°; The driving waveforms of the switches S15, S35, S213, and S413 are the same; the driving waveforms of the switches S16, S36, S214, and S414 are the same; the driving waveforms of the switches S15 and S16 are complementary; the driving waveform of the switch S15 lags behind the driving waveform of the switch S11 by 90°; The driving waveforms of the switches S17, S37, S215, and S415 are the same. The driving waveforms of the switches S18, S38, S216, and S416 are the same. The driving waveforms of the switches S17 and S18 are complementary. The driving waveform of the switch S17 lags behind the driving waveform of the switch S11 by 135°. The driving waveforms of the switches S19, S39, S21, and S41 are the same. The driving waveforms of the switches S110, S310, S22, and S42 are the same. The driving waveforms of the switches S19 and S110 are complementary. The driving waveform of the switch S19 lags behind the driving waveform of the switch S11 by 180°. The driving waveforms of the switches S111, S311, S23, and S43 are the same. The driving waveforms of the switches S112, S312, S24, and S44 are the same. The driving waveforms of the switches S111 and S112 are complementary. The driving waveform of the switch S111 lags behind the driving waveform of the switch S11 by 225°. The driving waveforms of the switches S113, S313, S25, and S45 are the same. The driving waveforms of the switches S114, S314, S26, and S46 are the same. The driving waveforms of the switches S113 and S114 are complementary. The driving waveform of the switch S113 lags behind the driving waveform of the switch S11 by 270°. The driving waveforms of the switches S115, S315, S27, and S47 are the same. The driving waveforms of the switches S116, S316, S28, and S48 are the same. The driving waveforms of the switches S115 and S116 are complementary. The driving waveform of the switch S115 lags behind the driving waveform of the switch S11 by 315°.

6. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The switch tubes in the converter are all gallium nitride switch tubes.

7. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The driving waveform of the switch tube in the converter is provided with a dead time.

8. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The duty cycle D of the driving waveform of the switch tube in the converter when working is less than 0.

125.

9. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The gain calculation formula of the converter is: In formula (1), V in Indicates the input voltage, V out represents the output voltage, and D represents the duty cycle of the driving waveform.

10. The large transformation ratio inductor transformer hybrid converter according to claim 1, characterized in that: The total ripple value of the inductor current of the converter is calculated as follows: In formula (2), V in Indicates the input voltage, V out represents the output voltage, D represents the duty cycle of the driving waveform, T represents the switching period, L represents the special phase inductance value, L m Indicates the excitation inductance of the common phase transformer, ΔI Lsum Indicates the total ripple value of the inductor current.

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