Power conversion device

Abstract

According to the power conversion device, the layout structure and the winding mode of the winding of the power conversion device are optimized, so that the thickness and the size of the power conversion device are further reduced; and on the other hand, by optimizing a control / driving mode, low-loss driving control of a plurality of switches is realized through four control signals.

Description

A power conversion device Technical Field

[0001] This invention belongs to the field of high-frequency power supply technology, and particularly relates to a power conversion device.

[0002] With the development of artificial intelligence, the power requirements of intelligent data processing chips, such as GPUs / CPUs / NPUs (collectively referred to as xPUs), are increasing, leading to a significant increase in server power consumption. Server input voltages are gradually shifting from 12V to 48V. Meanwhile, the operating voltage of xPUs is decreasing with advancements in manufacturing processes, moving from 0.8V to 0.65V. Therefore, the ratio of input voltage to output voltage is becoming increasingly larger, making the two-stage buck converter architecture the mainstream. This two-stage buck converter architecture includes a proportional converter in the front stage and a voltage regulator in the back stage.

[0003] This invention proposes a power conversion circuit for a front-stage proportional converter that converts a 48V input voltage into an intermediate bus voltage. By optimizing the winding method of the transformer windings and the layout of the power devices, and by using a low-loss drive circuit, the front-stage proportional converter achieves low-loss and small-size characteristics. Summary of the Invention

[0004] In view of this, one of the objectives of the present invention is to provide a power conversion device, including a substrate, a magnetic core assembly, a winding, a first sub-circuit, and a second sub-circuit. The first sub-circuit includes four first down switches, and the second sub-circuit includes four second down switches. The magnetic core assembly includes an upper magnetic cover, a lower magnetic cover, and four magnetic pillars disposed between the upper and lower magnetic covers, arranged in a 2x2 configuration. The substrate includes opposing upper and lower surfaces, and four slots penetrating the upper and lower surfaces, with each slot allowing one magnetic pillar to pass through. The upper and lower magnetic covers respectively fasten to the substrate from the upper and lower surfaces. The winding passes through the slots. The magnetic core assembly includes opposing first and second sides. Down switch groups are disposed along both the first and second sides, each down switch group including a first down switch, a second down switch, a second down switch, and a first down switch arranged sequentially. The first and second ends of the winding are disposed adjacent to the first and / or the second sides. Preferably, the first sub-circuit further includes a first upper switch and a first middle switch; the second sub-circuit further includes a second upper switch and a second middle switch; the power conversion device includes an input positive terminal, an input negative terminal, an output positive terminal, and an output negative terminal; the drain of each upper switch is electrically connected to the input positive terminal, the source of the first upper switch and the drain of the first middle switch are electrically connected to a first upper node, and the source of the second upper switch and the drain of the second middle switch are electrically connected to a second upper node; the first lower switch is connected between the first lower node and the output negative terminal, and the second lower switch is connected between the second lower node and the output negative terminal; the first upper switch, the second upper switch, the first middle switch, and the second middle switch are all disposed on the first side of the magnetic core assembly and are all disposed adjacent to the lower switch group; the source of the first middle switch is electrically connected to the first lower node or the input negative terminal, and the source of the second middle switch is electrically connected to the second lower node or the input negative terminal.

[0005] Preferably, the assembly further includes output capacitors, which are respectively disposed on the first and second sides of the magnetic core assembly, and are disposed adjacent to the lower switch group; the projections of the output capacitors disposed on the lower surface and the lower switch group disposed on the upper surface on the same horizontal plane at least partially overlap.

[0006] Preferably, the system further includes an input capacitor disposed on the lower surface of the substrate, and the first upper switch, the second upper switch, the first middle switch, and the second middle switch disposed on the upper surface of the substrate. The projection of the input capacitor onto at least one of the first upper switch, the second upper switch, the first middle switch, and the second middle switch on the same horizontal plane at least partially overlaps.

[0007] Preferably, the winding includes a high-voltage winding, a first low-voltage winding, and a second low-voltage winding; the power conversion device further includes a resonant capacitor, which is connected in series with the high-voltage winding and then spans between the first upper node and the second upper node; the first ends of the first low-voltage winding and the second low-voltage winding are electrically connected to the first lower node and the second lower node, respectively, and the second ends of the first low-voltage winding and the second low-voltage winding are shorted to the output positive terminal.

[0008] Preferably, the resonant capacitor is disposed on the lower surface of the substrate, and the resonant capacitor is disposed adjacent to the first upper switch and the second upper switch.

[0009] Preferably, it further includes two sets of output electrical connectors, each set of which is respectively disposed on the first side and the second side of the magnetic core assembly.

[0010] Preferably, the four slots include a first slot, a second slot, a third slot, and a fourth slot, which are arranged sequentially in the same direction. The first and second ends of the high-voltage winding are both located adjacent to the first side of the magnetic core assembly, and the substrate is a multilayer printed circuit board. From the first end to the second end, the high-voltage winding firstly winds clockwise around the first slot for half a turn on the first layer, passes through the second via to reach the second layer, then winds clockwise around the first slot for one turn, then winds counterclockwise around the fourth slot for one turn, passes through the fourth via to return to the first layer, then winds counterclockwise around the fourth slot for one turn, then winds clockwise around the third slot for one turn, passes through the third via to reach the second layer, then winds clockwise around the third slot for one turn, then winds counterclockwise around the second slot for one turn, passes through the first via to reach the first layer, winds counterclockwise around the second slot for one turn, and finally winds clockwise around the first slot for half a turn to return to the second end.

[0011] Preferably, each of the low-voltage windings includes four sub-windings, each of the sub-windings being wound around a slot once; the winding directions of each low-voltage winding are opposite in any two adjacent slots; on the first and second sides of the magnetic core assembly, the second end of the first low-voltage winding is disposed between the two first ends, and the first end of the second low-voltage winding is disposed between the two second ends.

[0012] The present invention also provides a power conversion device, including a first sub-circuit, a second sub-circuit, four control signals, a timing control / drive circuit, and a low-loss drive circuit; the first sub-circuit includes a first upper switch, a first middle switch, and a first lower switch, and the second sub-circuit includes a second upper switch, a second middle switch, and a second lower switch; the four control signals, via the timing control / drive circuit, generate two upper drive signals, two middle drive signals, a first intermediate signal, a second intermediate signal, a third intermediate signal, and a fourth intermediate signal; the two upper drive signals are used to control the opening and closing of the first upper switch and the second upper switch, respectively, and the two middle drive signals are used to control the opening and closing of the first middle switch and the second middle switch, respectively; the first intermediate signal, the second intermediate signal, the third intermediate signal, and the fourth intermediate signal, via the low-loss drive circuit, generate two lower drive signals, which are used to control the opening and closing of the first lower switch and the second lower switch, respectively; the four control signals are respectively a first control signal, a second control signal, a third control signal, and a fourth control signal.

[0013] Preferably, the first intermediate signal and the second intermediate signal are generated by the third control signal, and the third intermediate signal and the fourth intermediate signal are generated by the fourth control signal.

[0014] Preferably, the rising edge of the first intermediate signal coincides with the rising edge of the third control signal, and the falling edge of the first intermediate signal is delayed by the falling edge of the third control signal; the rising edge of the second intermediate signal is delayed by the rising edge of the third control signal, and the falling edge of the second intermediate signal coincides with the falling edge of the third control signal; the rising edge of the third intermediate signal coincides with the rising edge of the fourth control signal, and the falling edge of the third intermediate signal is delayed by the falling edge of the fourth control signal; the rising edge of the fourth intermediate signal is delayed by the rising edge of the fourth control signal, and the falling edge of the fourth intermediate signal coincides with the falling edge of the fourth control signal.

[0015] Preferably, the low-loss drive circuit includes an auxiliary positive terminal, an auxiliary negative terminal, a drive inductor, a first drive bridge arm, and a second drive bridge arm; both the first and second drive bridge arms are connected between the auxiliary positive terminal and the auxiliary negative terminal; the first drive bridge arm includes a first upper drive switch and a first lower drive switch, which are connected in series to a second drive point; the second drive bridge arm includes a second upper drive switch and a second lower drive switch, which are connected in series to a first drive point; the drive inductor is connected between the first and second drive points; the auxiliary negative terminal is electrically connected to the output negative terminal; the first intermediate signal is used to control the opening and closing of the first upper drive switch, the second intermediate signal is used to control the opening and closing of the first lower drive switch, the third intermediate signal is used to control the opening and closing of the second upper drive switch, and the fourth intermediate signal is used to control the opening and closing of the second lower drive switch.

[0016] Preferably, the first driving point is electrically connected to the gate of the first lower switch to drive the first lower switch to turn on and off; the second driving point is electrically connected to the gate of the second lower switch to drive the second lower switch to turn on and off; one switching cycle of the power conversion device includes a first interval, a second interval, a first dead zone, and a second dead zone; in the first interval, the first driving point is at a high potential relative to the negative output terminal, and the second driving point is at a low potential relative to the negative output terminal; in the second interval, the second driving point is at a high potential relative to the negative output terminal, and the first driving point is at a low potential relative to the negative output terminal; in the first dead zone, the voltage of the first driving point relative to the negative output terminal decreases from a high potential to a low potential, and the voltage of the second driving point relative to the negative output terminal increases from a low potential to a high potential; in the second dead zone, the voltage of the second driving point relative to the negative output terminal decreases from a high potential to a low potential, and the voltage of the first driving point relative to the negative output terminal increases from a low potential to a high potential.

[0017] Preferably, within the first dead zone, the interval in which the voltage of the first driving point to the negative output terminal decreases from a high potential to a low potential does not overlap with the interval in which the voltage of the second driving point to the negative output terminal increases from a low potential to a high potential; and within the second dead zone, the interval in which the voltage of the second driving point to the negative output terminal decreases from a high potential to a low potential does not overlap with the interval in which the voltage of the first driving point to the negative output terminal increases from a low potential to a high potential.

[0018] Preferably, the first control signal and the second control signal have the same duty cycle and are out of phase by 180 degrees; the third control signal is complementary to the second control signal, and the fourth control signal is complementary to the first control signal.

[0019] Preferably, the first upper drive signal and the second middle drive signal are generated by the first control signal, and the second upper drive signal and the first middle drive signal are generated by the second control signal.

[0020] The beneficial effects of the present invention are: (1) The present invention further reduces the thickness and volume of the power conversion device by optimizing the layout structure and winding method of the power conversion device; (2) On the other hand, it provides a control / drive method for the power conversion device, and realizes low-loss drive control of multiple switches through four control signals. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1A shows the topology of a non-isolated power conversion circuit; Figure 1B shows the topology of an isolated power conversion circuit; Figures 2A to 2C show the drive circuit and timing diagram; Figures 3A to 3C show the three-dimensional structure diagram; Figures 4A to 4E show the winding diagram. Detailed Implementation

[0023] One of the core aspects of this invention is to provide a power conversion device, including the structure of the power conversion device and the control / drive method.

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The proportional converter circuit disclosed in this invention is shown in Figures 1A and 1B. Figure 1A shows a non-isolated power conversion circuit topology, and Figure 1B shows an isolated power conversion circuit topology. As shown in Figure 1A, the non-isolated power conversion circuit includes an input terminal, an output terminal, a first sub-circuit 1a, a second sub-circuit 2a, a magnetic component, and a resonant capacitor. The input terminal includes a positive input terminal Vin+ and a negative input terminal Vin-, and the output terminal includes a positive output terminal Vo+ and a negative output terminal Vo-. In this embodiment, the negative input terminal Vin- and the negative output terminal Vo- are short-circuited. Each sub-circuit includes an upper switch, a middle switch, and a lower switch connected in series. For example: the first sub-circuit 1a includes an upper switch Q1, a middle switch Q3, and a lower switch SR1 connected in series; the second sub-circuit 2a includes an upper switch Q2, a middle switch Q4, and a lower switch SR2 connected in series; wherein, the upper switch Q1 is connected between the positive input terminal Vin+ and the first upper node SWH1, the middle switch Q3 is connected between the first upper node SWH1 and the first lower node SWL1, and the lower switch SR1 is connected between the first lower node SWL1 and the negative input terminal Vin-. The upper switch Q2 is connected between the positive input terminal Vin+ and the second upper node SWH2, the middle switch Q4 is connected between the second upper node SWH2 and the second lower node SWL2, and the lower switch SR2 is connected between the second lower node SWL2 and the negative input terminal Vin-. The magnetic components include a high-voltage winding TW11, a first low-voltage winding TW12, and a second low-voltage winding TW13. The high-voltage winding TW11 and the resonant capacitor C1 are connected in series at connection point SWH1-1, forming a series branch that spans between the first upper node SWH1 and the second upper node SWH2. The second end of the first low-voltage winding TW12 and the second end of the second low-voltage winding TW13 are electrically connected to the positive output terminal Vo+. The first end of the first low-voltage winding TW12 is electrically connected to the first lower node SWL1, and the first end of the second low-voltage winding TW13 is electrically connected to the second lower node SWL2. The proportional converter circuit also includes an input capacitor Cin and an output capacitor Co. The input capacitor Cin is connected between the positive input terminal Vin+ and the negative input terminal Vin-, and the output capacitor Co is connected between the positive output terminal Vo+ and the negative output terminal Vo-. The second end of the high-voltage winding TW11 (i.e., the upper node SWH2), the first end of the first low-voltage winding TW12 (i.e., the lower node SWL1), and the second end of the second low-voltage winding TW13 (i.e., the output positive terminal Vo+) are the same-named terminals and are marked as point terminals.

[0026] Figure 1B shows an isolated power conversion circuit. The difference between this circuit and Figure 1A is that the input negative terminal Vin- and the output negative terminal Vo- are not shorted. It also includes a first sub-circuit and a second sub-circuit. Each sub-circuit includes an upper switch, a middle switch, and a lower switch connected in series. In the first sub-circuit, the upper switch Q1 is connected between the first upper node SWH1 and the input positive terminal Vin+; the middle switch Q3 is connected between the first upper node SWH1 and the input negative terminal Vin-; and the lower switch SR1 is connected between the first lower node SWL1 and the output negative terminal Vo-. In the second sub-circuit, the upper switch Q2 is connected between the input positive terminal Vin+ and the second upper node SWH2; the middle switch Q4 is connected between the second upper node SWH2 and the input negative terminal Vin-; and the lower switch SR2 is connected between the second lower node SWL2 and the output negative terminal Vo-. The input capacitor Cin is connected between the input positive terminal Vin+ and the input negative terminal Vin-. The connection methods of other components are the same as in Figure 1A and will not be described again.

[0027] To reduce drive losses, this invention also discloses a lossless drive circuit that can be used in power conversion devices employing the circuits shown in Figures 1A and 1B, as detailed in Figures 2A to 2C. Figure 2A shows a schematic diagram of the control signals, Figure 2B shows a schematic diagram of the lossless drive circuit, and Figure 2C shows the timing sequence of the control and drive signals. As shown in Figure 2A, the lossless drive circuit includes a first control signal PWM1, a second control signal PWM2, a third control signal PWM3, and a fourth control signal PWM4. Referring to Figure 2C, the first control signal PWM1 and the second control signal PWM2 have the same duty cycle and are out of phase by 180 degrees, with a dead time TD1 between them. The third control signal PWM3 is complementary to the second control signal PWM2, and a dead time TD2 exists between them. The fourth control signal PWM4 is complementary to the first control signal PWM1, and a dead time TD2 exists between them.

[0028] Four control signals, transmitted via a timing and driving circuit, generate upper drive signals GQ1 and GQ2, middle drive signals GQ3 and GQ4, a first intermediate signal GQD1, a second intermediate signal GQD2, a third intermediate signal GQD3, and a fourth intermediate signal GQD4. The upper drive signals GQ1 and GQ2 are used to turn the upper switches Q1 and Q2 on and off, respectively; the middle drive signals GQ3 and GQ4 are used to turn the middle switches Q3 and Q4 on and off, respectively. The upper drive signals GQ1 and GQ4 are generated by the first control signal PWM1; the upper drive signals GQ2 and GQ3 are generated by the second control signal PWM2. The presence of a dead time TD1 prevents shoot-through of the upper and middle switches.

[0029] As shown in Figure 2B, the lossless drive circuit includes an auxiliary positive terminal Vaux+, an auxiliary negative terminal (i.e., the output negative terminal Vo-), a drive inductor L1, an auxiliary capacitor Caux, a first drive bridge arm 1b, and a second drive bridge arm 2b. The first drive bridge arm 1b includes an upper drive switch QD3 and a lower drive switch QD4 connected in series, and the second drive bridge arm 2b includes an upper drive switch QD1 and a lower drive switch QD2 connected in series. Both drive bridge arms 1b and 2b are connected across the auxiliary positive terminal Vaux+ and the output negative terminal Vo-. The upper drive switches QD1 and QD3 are PMOS, and the lower drive switches QD2 and QD4 are NMOS. The sources of the upper drive switches QD1 and QD3 are electrically connected to the auxiliary positive terminal Vaux+, and the sources of the lower drive switches QD2 and QD4 are electrically connected to the output negative terminal Vo-. The drain of the upper drive switch QD3 and the drain of the lower drive switch QD4 are electrically connected to the first drive point SWD1, and the drain of the upper drive switch QD1 and the drain of the lower drive switch QD2 are electrically connected to the second drive point SWD2. The drive inductor L1 is connected between the first drive point SWD1 and the second drive point SWD2. The auxiliary capacitor Caux is connected between the auxiliary positive terminal Vaux and the output negative terminal Vo-.

[0030] The first intermediate signal GQD1 and the second intermediate signal GQD2 are generated by the third control signal PWM3. Through a timing control / drive circuit, the rising edge of the first intermediate signal GQD1 coincides with the rising edge of the third control signal PWM3, and the falling edge of the first intermediate signal GQD1 is delayed by TD5 compared to the falling edge of the third control signal PWM3, i.e., the interval between time t3 and time t4. The rising edge of the second intermediate signal GQD2 is delayed by TD3 compared to the rising edge of the third control signal PWM3, i.e., the interval between time t5 and t6; the falling edge of the second intermediate signal GQD2 coincides with the falling edge of the third control signal PWM3.

[0031] The third intermediate signal GQD3 and the fourth intermediate signal GQD4 are generated by the fourth control signal PWM4. Through a timing control / drive circuit, the rising edge of the third intermediate signal GQD3 coincides with the rising edge of the fourth control signal PWM4, and the falling edge of the third intermediate signal GQD3 is delayed by TD6 compared to the falling edge of the fourth control signal PWM4, i.e., the interval between time t6 and time t7. The rising edge of the fourth intermediate signal GQD4 is delayed by TD4 compared to the rising edge of the fourth control signal PWM4, i.e., the interval between time t2 and time t3; the falling edge of the fourth intermediate signal GQD4 coincides with the falling edge of the fourth control signal PWM4. Here, it is optimal for the delay TD3 to equal the delay TD4, and optimal for the delay TD5 to equal the delay TD6.

[0032] The first intermediate signal GQD1 is used to control the opening and closing of the upper drive switch QD1; the second intermediate signal GQD2 is used to control the opening and closing of the lower drive switch QD2; the third control signal GQD3 is used to control the opening and closing of the upper drive switch QD3; and the fourth intermediate signal GQD4 is used to control the opening and closing of the lower drive switch QD4.

[0033] During the interval t0-t1, the second intermediate signal GQD2 is high, controlling the lower drive switch QD2 to conduct, making the voltage of the second drive point SWD2 low (i.e., 0). At this time, because the first drive point SWD1 is electrically connected to the gate of the lower switch SR1, the gate capacitance of the lower switch SR1 resonates with the drive inductor L1, causing the voltage of the first drive point SWD1 to change from 0 to Vaux+ (i.e., high). During the interval t1-t2, the third intermediate signal GQD3 is low, controlling the upper drive switch QD3 to conduct, making the voltage of the first drive point SWD1 Vaux+. The first drive point SWD1 is electrically connected to the gate of the lower switch SR1, therefore the lower switch SR1 conducts. During the interval t2-t3, the third intermediate signal GQD3 is high, the upper switch QD3 is off, causing the drive inductor L1 to resonate with the gate capacitance of the lower switch SR1, changing the voltage of the first drive point SWD1 from Vaux+ to 0, and the lower switch SR1 is off. In the interval t3-t4: the fourth intermediate signal GQD4 is high, the lower drive switch QD4 is turned on, making the voltage of the first drive point SWD1 0. At this time, the lower drive switch QD2 is off, and the drive inductor L1 resonates with the gate capacitance of the lower switch SR2, raising the voltage of the second drive point SWD2 from 0 to Vaux+. In the interval t4-t5: the first intermediate signal GQD1 is low, the upper drive switch QD1 is turned on, making the voltage of the second drive point SWD2 Vaux+, and the lower switch SR2 is turned on. In the interval t5-t6: the first intermediate signal GQD1 is high, the upper drive switch QD1 is turned off, making the drive inductor L1 resonate with the gate capacitance of the lower switch SR2, changing the voltage of the second drive point SWD2 from Vaux+ to 0. The interval from time t0 to time t6 is one complete switching cycle Ts.

[0034] The voltage waveforms of the first drive point SWD1 and the second drive point SWD2 are shown in Figure 2C. When delay TD3 equals delay TD4 and delay TD5 equals delay TD6, the voltage waveforms of the first drive point SWD1 and the second drive point SWD2 are the same, but out of phase by 180 degrees. The first drive point SWD1 is electrically connected to the gate of the lower switch SR1 to control the opening and closing of the lower switch SR1; the second drive point SWD2 is electrically connected to the gate of the lower switch SR2 to control the opening and closing of the lower switch SR2. The current waveform flowing through the drive inductor L1 is shown in Figure 2C. By applying the drive circuit shown in Figure 2B, the drive loss of the lower switch can be further reduced, and the conversion efficiency of the power conversion device can be improved.

[0035] The present invention also discloses the layout of a power conversion device. Referring to Figures 3A to 3C, the power conversion device further includes a substrate 10 and a magnetic core assembly 20. The substrate 10 includes an upper surface 101 and a lower surface 102. The magnetic core assembly 20 includes an upper magnetic cover 21, a lower magnetic cover 22, and four magnetic pillars 23, 24, 25, and 26. The substrate includes four slots 13, 14, 15, and 16, each slot through which a corresponding magnetic pillar passes. The upper magnetic cover 21 and the lower magnetic cover 22 fasten the substrate 10 from the upper surface 101 and the lower surface 102, respectively. The four slots 13, 14, 15, and 16 are arranged in a 2x2 array. The interior or surface of the substrate between adjacent slots is used to accommodate high-voltage windings and low-voltage windings. Multiple lower switches SR1 and SR2 are respectively disposed on opposite sides of the magnetic core assembly 20, as shown in Figure 3A. One set of lower switches is disposed along the first side 201 of the magnetic core assembly 20 in the order SR1-SR2-SR2-SR1, and another set of lower switches is disposed along the second side 202 of the magnetic core assembly 20 in the order SR1-SR2-SR2-SR1. In this embodiment, the lower switches are disposed on the upper surface 101 of the substrate; in other embodiments, the lower switches may be disposed on both the upper surface 101 and the lower surface 102 of the substrate, as long as they are disposed adjacent to the side of the magnetic core assembly and the projections of the lower switches disposed on the upper and lower surfaces on the same horizontal plane at least partially overlap. Upper switches Q1 and Q2 and middle switches Q3 and Q4 are arranged adjacent to a set of lower switches. The drains of upper switches Q1 and Q2 are electrically connected to the positive input terminal Vin+. The source of upper switch Q1 is electrically connected to the drain of middle switch Q3, the source of upper switch Q2 is electrically connected to the drain of middle switch Q4, the source of middle switch Q3 is electrically connected to the drain of lower switch SR1 and the first end of low-voltage winding TW12, and the source of middle switch Q4 is electrically connected to the drain of lower switch SR2 and the first end of low-voltage winding TW13. In this embodiment, the height difference between the upper surface of the switches and the upper surface of the magnetic components is less than 1 mm, which is beneficial for assembling heat dissipation components.

[0036] The power conversion device also includes an output capacitor Co, an input capacitor Cin, and an output electrical connector. In this embodiment, the output capacitor Co is disposed on the upper surface 101 and the lower surface 102. On the upper surface 101, the output capacitor Co is disposed adjacent to each set of lower switches, i.e., the lower switches are disposed between the output capacitor and the magnetic core. On the lower surface 102, the output capacitor Co is disposed on the first side 201 and the second side 202 of the magnetic core assembly, and the projections of the output capacitor Co on the lower surface 102 and the lower switches on the upper surface 101 on the same horizontal plane overlap by at least 30%. The sources of lower switches SR1 and SR2 are short-circuited, the second ends of the low-voltage windings TW12 and TW13 are short-circuited, and the output capacitor Co is connected across the source of the lower switches and the second end of the low-voltage windings. The resonant capacitor C1 is disposed on the lower surface 102 of the substrate and is disposed adjacent to the upper and middle switches. An input capacitor Cin is disposed on the lower surface 102 of the substrate and adjacent to the upper switch and the middle switch. The projections of the input capacitor Cin disposed on the lower surface 102 and the upper switch or middle switch disposed on the upper surface 101 overlap by at least 30% on the same horizontal plane. Output electrical connectors 110 are disposed adjacent to the first side 201 and the second side 202 opposite to the magnetic core assembly, respectively. The power conversion device also includes an input electrical connector disposed on the lower surface 102 of the substrate. The input and output electrical connectors are used for fixing and electrically connecting with other components, which may be adapter boards or client system boards.

[0037] This invention also discloses the winding methods of the high-voltage winding and the low-voltage winding, as shown in Figures 4A to 4E. The winding method of the high-voltage winding is shown in Figure 4A. Starting from node SWH1_1 (i.e., the short-circuit point between the resonant capacitor C1 and the high-voltage winding, i.e., the first end of the high-voltage winding), firstly, half a turn is wound clockwise around the first slot 13 in the first layer 111, and then the winding reaches the second layer 112 through the second through hole VH2. Next, one turn is wound clockwise around the first slot 13, and then one turn is wound counterclockwise around the fourth slot 16, and then the winding reaches the second layer 112 through the fourth through hole VH2. The winding returns to the first layer 111 via VH4, then winds counterclockwise around the fourth slot 16 once, then clockwise around the third slot 15 once, then through the third via VH3 to the second layer 112, then clockwise around the third slot 15 once, then counterclockwise around the second slot 14 once, then through the first via VH1 to the first layer 111, then counterclockwise around the second slot 14 once, and finally clockwise around the first slot 13 half a turn back to SWH2 (i.e., the second end of the high-voltage winding).

[0038] As shown in Figures 4B and 4C, one winding method for low-voltage windings TW12 and TW13 is provided. The first and second ends of low-voltage winding TW12 are both located on the first side 201 and the second side 202 of the magnetic core assembly. Specifically, low-voltage winding TW12 is located on the third layer 113 and includes four sub-windings. Each sub-winding is wound once around a slot, and the winding directions on any two adjacent slots are opposite. For example, the low-voltage winding winds from the first end (SWL1) to the second end (Vo+) are wound around the first slot... The first slot 13 is wound counterclockwise once, and from the first end (SWL1) to the second end (Vo+), it is wound clockwise once around the second slot 14. From the first end (SWL1) to the second end (Vo+), it is wound counterclockwise once around the third slot 15. From the first end (SWL1) to the second end (Vo+), it is wound clockwise once around the fourth slot 16. Furthermore, on the first side 201 and the second side 202 of the magnetic core assembly, the second end of the low-voltage winding TW12 is positioned between the two first ends. The low-voltage winding TW13 is located in the fourth layer 114 and includes four sub-windings. Each sub-winding is wound once around a slot, and the winding directions on any two adjacent slots are opposite. On the first side 201 and the second side 202 of the magnetic core assembly, the first end (SWL2) of the low-voltage winding TW13 is positioned between the two second ends (Vo+). In this embodiment, each low-voltage winding can also be implemented using multiple layers in parallel. The first, second, third, and fourth layers here simply represent different layers, not the order in which they are arranged. This winding arrangement reduces the number of connection vias and the winding impedance. The opposite winding directions of adjacent low-voltage windings mean that the magnetic flux of adjacent magnetic cores is also opposite, which helps to reduce the thickness of the upper and lower covers of the magnetic core and decrease thermal resistance.

[0039] In another embodiment, adjacent wirings with the same potential in the low-voltage winding can be short-circuited, or a single sheet of copper can be used. As shown in Figures 4D and 4E, wiring between any two adjacent slots can be short-circuited. This can further reduce parasitic parameters on or between windings, improving the performance of the power conversion device.

[0040] The switching transistor disclosed in this invention can be a Si MOSFET, SiC MOSFET, GaN device, or IGBT, etc., all of which can realize the switching function disclosed in this invention.

[0041] The power module described in the above embodiments can also be part of an electronic device, as long as it meets the technical features and benefits disclosed in this invention.

[0042] The terms "equal to," "identical to," or "equal to" disclosed in this invention must take into account the parameter distribution of the engineering process, with an error distribution within ±30%. "Parallel" is defined as the angle between two line segments or lines being less than or equal to 45 degrees. "Perpendicular" is defined as the angle between two line segments or lines being within the range of [60, 120] degrees. The definition of "phase misalignment" also needs to consider the parameter distribution of the engineering process, with an error distribution of the phase misalignment degree within ±30%.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power conversion device, characterized in that, The device includes a substrate, a magnetic core assembly, a winding, a first sub-circuit, and a second sub-circuit. The first sub-circuit includes four first lower switches, and the second sub-circuit includes four second lower switches. The magnetic core assembly includes an upper magnetic cover, a lower magnetic cover, and four magnetic pillars. The four magnetic pillars are disposed between the upper and lower magnetic covers and are arranged in a 2x2 configuration. The substrate includes opposing upper and lower surfaces and four slots that penetrate the upper and lower surfaces, with each slot allowing one magnetic pillar to pass through. The upper and lower magnetic covers fasten to the substrate from the upper and lower surfaces, respectively. The winding passes through the slots. The magnetic core assembly includes opposing first and second sides. Lower switch groups are disposed along both the first and second sides, each lower switch group including a first lower switch, a second lower switch, a second lower switch, and a first lower switch arranged sequentially. The first and second ends of the winding are disposed adjacent to the first and / or the second sides.

2. The power conversion device according to claim 1, characterized in that, The first sub-circuit further includes a first upper switch and a first middle switch; the second sub-circuit further includes a second upper switch and a second middle switch; the power conversion device includes an input positive terminal, an input negative terminal, an output positive terminal, and an output negative terminal; the drain of each upper switch is electrically connected to the input positive terminal, the source of the first upper switch and the drain of the first middle switch are electrically connected to a first upper node, and the source of the second upper switch and the drain of the second middle switch are electrically connected to a second upper node; the first lower switch is connected between the first lower node and the output negative terminal, and the second lower switch is connected between the second lower node and the output negative terminal; the first upper switch, the second upper switch, the first middle switch, and the second middle switch are all disposed on the first side of the magnetic core assembly and are all disposed adjacent to the lower switch group; the source of the first middle switch is electrically connected to the first lower node or the input negative terminal, and the source of the second middle switch is electrically connected to the second lower node or the input negative terminal.

3. The power conversion device according to claim 1, characterized in that, It also includes output capacitors, which are respectively disposed on the first and second sides of the magnetic core assembly, and are all disposed adjacent to the lower switch group; the projections of the output capacitors disposed on the lower surface and the lower switch group disposed on the upper surface on the same horizontal plane at least partially overlap.

4. The power conversion device according to claim 2, characterized in that, It also includes an input capacitor disposed on the lower surface of the substrate, and the first upper switch, the second upper switch, the first middle switch and the second middle switch disposed on the upper surface of the substrate. The projection of the input capacitor on at least one of the first upper switch, the second upper switch, the first middle switch and the second middle switch on the same horizontal plane at least partially overlaps.

5. The power conversion device according to claim 2, characterized in that, The winding includes a high-voltage winding, a first low-voltage winding, and a second low-voltage winding; the power conversion device also includes a resonant capacitor, which is connected in series with the high-voltage winding and then spans between the first upper node and the second upper node; the first ends of the first low-voltage winding and the second low-voltage winding are electrically connected to the first lower node and the second lower node, respectively, and the second ends of the first low-voltage winding and the second low-voltage winding are shorted to the output positive terminal.

6. The power conversion device according to claim 5, characterized in that, The resonant capacitor is disposed on the lower surface of the substrate, and is disposed adjacent to the first upper switch and the second upper switch.

7. The power conversion device according to claim 1, characterized in that, It also includes two sets of output electrical connectors, each set of which is respectively disposed on the first side and the second side of the magnetic core assembly.

8. The power conversion device according to claim 5, characterized in that, The four slots include a first slot, a second slot, a third slot, and a fourth slot, which are arranged sequentially in the same direction. The first and second ends of the high-voltage winding are both located adjacent to the first side of the magnetic core assembly. The substrate is a multilayer printed circuit board. From the first end to the second end, the high-voltage winding firstly winds clockwise around the first slot for half a turn on the first layer, passes through the second via to reach the second layer, then winds clockwise around the first slot for one turn, then winds counterclockwise around the fourth slot for one turn, passes through the fourth via to return to the first layer, then winds counterclockwise around the fourth slot for one turn, then winds clockwise around the third slot for one turn, passes through the third via to reach the second layer, then winds clockwise around the third slot for one turn, then winds counterclockwise around the second slot for one turn, passes through the first via to reach the first layer, winds counterclockwise around the second slot for one turn, and finally winds clockwise around the first slot for half a turn to return to the second end.

9. The power conversion device according to claim 8, characterized in that, Each of the low-voltage windings includes four sub-windings, each of the sub-windings being wound once around a slot; the winding directions of each low-voltage winding are opposite in any two adjacent slots; on the first and second sides of the magnetic core assembly, the second end of the first low-voltage winding is disposed between the two first ends, and the first end of the second low-voltage winding is disposed between the two second ends.

10. A power conversion device, characterized in that, The system includes a first sub-circuit, a second sub-circuit, four control signals, a timing control / drive circuit, and a low-loss drive circuit. The first sub-circuit includes a first upper switch, a first middle switch, and a first lower switch. The second sub-circuit includes a second upper switch, a second middle switch, and a second lower switch. The four control signals, via the timing control / drive circuit, generate two upper drive signals, two middle drive signals, a first intermediate signal, a second intermediate signal, a third intermediate signal, and a fourth intermediate signal. The two upper drive signals are used to control the opening and closing of the first upper switch and the second upper switch, respectively. The two middle drive signals are used to control the opening and closing of the first middle switch and the second middle switch, respectively. The first intermediate signal, the second intermediate signal, the third intermediate signal, and the fourth intermediate signal generate two down-drive signals via the low-loss drive circuit. The two down-drive signals are used to control the opening and closing of the first down switch and the second down switch, respectively. The four control signals are the first control signal, the second control signal, the third control signal, and the fourth control signal, respectively.

11. The power conversion device according to claim 10, characterized in that, The first intermediate signal and the second intermediate signal are generated by the third control signal, and the third intermediate signal and the fourth intermediate signal are generated by the fourth control signal.

12. The power conversion device according to claim 11, characterized in that, The rising edge of the first intermediate signal coincides with the rising edge of the third control signal, and the falling edge of the first intermediate signal is delayed by the falling edge of the third control signal; the rising edge of the second intermediate signal is delayed by the rising edge of the third control signal, and the falling edge of the second intermediate signal coincides with the falling edge of the third control signal; the rising edge of the third intermediate signal coincides with the rising edge of the fourth control signal, and the falling edge of the third intermediate signal is delayed by the falling edge of the fourth control signal; the rising edge of the fourth intermediate signal is delayed by the rising edge of the fourth control signal, and the falling edge of the fourth intermediate signal coincides with the falling edge of the fourth control signal.

13. The power conversion device according to claim 12, characterized in that, The low-loss drive circuit includes an auxiliary positive terminal, an auxiliary negative terminal, a drive inductor, a first drive bridge arm, and a second drive bridge arm. Both the first and second drive bridge arms are connected between the auxiliary positive and auxiliary negative terminals. The first drive bridge arm includes a first upper drive switch and a first lower drive switch, which are connected in series to a second drive point. The second drive bridge arm includes a second upper drive switch and a second lower drive switch, which are connected in series to a first drive point. The drive inductor is connected between the first and second drive points. The auxiliary negative terminal is electrically connected to the output negative terminal. A first intermediate signal is used to control the on / off state of the first upper drive switch, a second intermediate signal is used to control the on / off state of the first lower drive switch, a third intermediate signal is used to control the on / off state of the second upper drive switch, and a fourth intermediate signal is used to control the on / off state of the second lower drive switch.

14. The power conversion device according to claim 13, characterized in that, The first driving point is electrically connected to the gate of the first lower switch and is used to drive the first lower switch to turn on and off; the second driving point is electrically connected to the gate of the second lower switch and is used to drive the second lower switch to turn on and off; one switching cycle of the power conversion device includes a first interval, a second interval, a first dead zone, and a second dead zone; in the first interval, the first driving point is at a high potential relative to the negative output terminal, and the second driving point is at a low potential relative to the negative output terminal; in the second interval, the second driving point is at a high potential relative to the negative output terminal, and the first driving point is at a low potential relative to the negative output terminal; in the first dead zone, the voltage of the first driving point relative to the negative output terminal decreases from a high potential to a low potential, and the voltage of the second driving point relative to the negative output terminal increases from a low potential to a high potential; in the second dead zone, the voltage of the second driving point relative to the negative output terminal decreases from a high potential to a low potential, and the voltage of the first driving point relative to the negative output terminal increases from a low potential to a high potential.

15. The power conversion device according to claim 14, characterized in that, Within the first dead zone, the interval where the voltage of the first driving point to the negative output terminal decreases from a high potential to a low potential does not overlap with the interval where the voltage of the second driving point to the negative output terminal increases from a low potential to a high potential; within the second dead zone, the interval where the voltage of the second driving point to the negative output terminal decreases from a high potential to a low potential does not overlap with the interval where the voltage of the first driving point to the negative output terminal increases from a low potential to a high potential.

16. The power conversion device according to claim 10, characterized in that, The first control signal and the second control signal have the same duty cycle and are out of phase by 180 degrees; the third control signal is complementary to the second control signal, and the fourth control signal is complementary to the first control signal.

17. The power conversion device according to claim 16, characterized in that, The first upper drive signal and the second middle drive signal are generated by the first control signal, and the second upper drive signal and the first middle drive signal are generated by the second control signal.

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