transformer

Abstract

The application provides a transformer, which realizes seamless switching of wide-range high-voltage multi-path input source by network competition of multi-path high-voltage input source, and improves power supply reliability; the transformer adopts a PCB, has high efficiency, high space utilization and simple peripheral circuit, realizes high efficiency and high integration under the premise of ensuring power level, greatly reduces voltage stress of the primary side switch tube by constructing a virtual bus midpoint and adopting a primary side double-winding structure to form two reverse flyback inputs, and makes the whole device have lower cost and more switch tubes for selection; synchronous rectification is used for output, which can reduce on-state loss and improve overall conversion efficiency, so that the whole device is comprehensively improved in cost, energy efficiency, space utilization and reliability.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically to a transformer. Background Technology

[0002] Faced with the exponential growth in power demand for data centers, the urgent need to reduce energy consumption, and the requirements for green environmental protection, unprecedented requirements have been placed on the power distribution architecture of data centers. Currently, the power distribution needs of data centers are mainly met through high-voltage DC power distribution architecture.

[0003] As data center rack power consumption climbs from kilowatts and hundreds of kilowatts to megawatts, the currently prevalent 48VDC power distribution architecture is gradually approaching its physical and economic limits. Simultaneously, the increasing power consumption of GPUs (Graphics Processing Units) in data centers leads to increased current flowing through power lines, resulting in higher transmission losses and heat generation. To address these challenges, there is a shift towards higher voltage DC power distribution solutions, with SST solid-state transformer power distribution architecture becoming a mainstream solution.

[0004] Solid State Transformers (SSTs) can handle input voltage levels up to 10kV, and some even reach 35kV. However, such high input voltages require cascading modules to distribute voltage across units. But the more modules cascaded, the higher the cost. Therefore, considering market demands, power distribution architectures need to comprehensively consider energy efficiency, cost, space utilization, and reliability. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the first objective of this invention is to provide a transformer.

[0006] The technical solution adopted in this invention is as follows:

[0007] An embodiment of the present invention proposes a transformer, comprising: a multi-channel high-voltage input source network, wherein the multi-channel high-voltage input source network is used to provide multiple input source voltages, the multiple input source voltages competing for power supply, and the input source voltages including AC voltages of different voltage levels, power module bus voltages, and battery voltages; a power pooling BUS network, wherein the power pooling BUS network is connected to the multi-channel high-voltage input source network, and the power pooling BUS network is used to construct a virtual bus midpoint BUSN; and a low-side input winding network, wherein the first input terminal of the low-side input winding network is connected to the virtual bus midpoint BUSN. The second input terminal is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network. The low-side input winding network is used to transmit the energy source from the virtual bus midpoint BUSN to the negative output terminal BUS-. The high-side input winding network has one end connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network and the other end connected to the virtual bus midpoint BUSN. The high-side input winding network is used to transmit the energy source from the positive output terminal BUS+ to the virtual bus midpoint BUSN. The PCB transformer network... The first primary winding of the PCB transformer network is connected to the output terminal of the low-side input winding network, and the second primary winding is connected to the output terminal of the high-side input winding network. This is used to transmit the energy source output by the low-side input winding network and the high-side input winding network to the secondary winding. The output synchronous rectifier winding network is connected to the secondary winding of the PCB transformer network. This is used to receive the energy source received by the secondary winding, rectify it, and output it to the load.

[0008] The transformer proposed above in this invention may also have the following additional technical features:

[0009] According to one embodiment of the present invention, the transformer further includes: a flyback control chip network, the flyback control chip network being connected to the control terminals of the low-side input winding network and the high-side input winding network, for outputting a first control signal to the low-side input winding network and the high-side input winding network, so that current flows from the virtual bus midpoint BUSN into the low-side input winding network and from the positive output terminal BUS+ into the high-side input winding network, to charge and store energy in the primary winding of the PCB transformer network, and outputting a second control signal to the low-side input winding network and the high-side input winding network, so as to transfer the energy stored in the primary winding of the PCB transformer network to the secondary winding of the PCB transformer network.

[0010] According to one embodiment of the present invention, the transformer further includes: a primary-side auxiliary winding network, one end of which is connected to the third primary winding of the PCB transformer network, and the other end of which is connected to the power supply terminal of the flyback control chip network and the virtual bus midpoint BUSN, for providing power supply voltage to the flyback control chip network; and a feedback network, which is connected between the primary-side auxiliary winding network and the voltage feedback terminal of the flyback control chip network, for feeding back the power supply voltage to the flyback control chip network.

[0011] According to one embodiment of the present invention, the multi-channel high-voltage input source network includes: first to sixth bridge arms connected in parallel, each bridge arm consisting of two diodes connected in series, the midpoints of the first and second bridge arms being connected to the positive and negative terminals of the AC voltage, the midpoints of the second and third bridge arms being connected to the positive and negative terminals of the power module bus voltage, the midpoints of the fourth and fifth bridge arms being connected to the positive and negative terminals of the battery voltage, one end of the first to sixth bridge arms being connected to the anode of a first diode, the cathode of the first diode serving as the positive output terminal BUS+ of the multi-channel high-voltage input source network, the other end of the first to sixth bridge arms being connected to the cathode of a second diode, and the anode of the second diode serving as the negative output terminal BUS- of the multi-channel high-voltage input source network.

[0012] According to one embodiment of the present invention, the power aggregation BUS network includes: a first capacitor, one end of which is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network; a second capacitor, one end of which is connected to the other end of the first capacitor, and the connection point between the other end of the first capacitor and one end of the second capacitor serves as the virtual bus midpoint BUSN, and the other end of the second capacitor is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network.

[0013] According to one embodiment of the present invention, the power pooling BUS network further includes a high-voltage buck network, the high-voltage buck network including a pre-start resistor and a third diode, one end of the pre-start resistor being connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network, the other end of the pre-start resistor being connected to the anode of the third diode, and the cathode of the third diode being connected to the power supply terminal of the flyback control chip network.

[0014] According to an embodiment of the present invention, the low-side input winding network includes: a first magnetizing inductor, the two ends of which are respectively connected to the two ends of the first primary winding; a first leakage inductor, one end of which is connected to one end of the first magnetizing inductor; a fourth diode, the anode of which is connected to the other end of the first leakage inductor, and the cathode of which is connected to the midpoint BUSN of the virtual bus; a first absorption network, one end of which is connected to the other end of the first leakage inductor, and the other end of which is connected to the other end of the first magnetizing inductor; a first switching transistor, the first end of which is connected to the other end of the first magnetizing inductor, the second end of which is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network, and the control terminal of which is connected to the flyback control chip network.

[0015] According to one embodiment of the present invention, the high-side input winding network includes: a second magnetizing inductor, the two ends of which are respectively connected to the two ends of the second primary winding; a second leakage inductor, one end of which is connected to one end of the second magnetizing inductor; a fifth diode, the anode of which is connected to the other end of the second leakage inductor, and the cathode of which is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network; a second absorption network, one end of which is connected to the other end of the second leakage inductor, and the other end of which is connected to the other end of the second magnetizing inductor; a second switching transistor, the first end of which is connected to the other end of the second magnetizing inductor, the second end of which is connected to the virtual bus midpoint BUSN through a current sampling network, and the control terminal of which is connected to the flyback control chip network.

[0016] According to an embodiment of the present invention, the output synchronous rectifier winding network includes: a third switching transistor, the first end of which is connected to one end of the secondary winding of the PCB transformer network; a third absorption network, which is connected between the first end and the second end of the third switching transistor; a third capacitor, one end of which is connected to the second end of the third switching transistor, and the other end of which is connected to the other end of the secondary winding of the PCB transformer network, the two ends of which serve as the output terminals of the transformer and are connected in parallel with the load; and a synchronous rectification control chip, which is connected to the control terminal of the third switching transistor, and the synchronous rectification control chip is used to output a control signal to the control terminal of the third switching transistor according to the voltage signal between the first end and the second end of the third switching transistor.

[0017] The beneficial effects of this invention are:

[0018] This invention achieves seamless switching between multiple high-voltage input sources over a wide range through competitive power supply via a multi-channel high-voltage input source network, thereby improving power supply reliability. It employs a PCB transformer, which boasts high efficiency, high space utilization, and simple peripheral circuitry, achieving high efficiency and high integration while maintaining power ratings. By constructing a virtual bus midpoint and using a primary-side dual-winding structure to form two flyback inputs, the voltage stress on the primary-side switching transistors is significantly reduced, resulting in lower overall device cost and a wider range of selectable switching transistors. Synchronous rectification at the output reduces conduction losses and improves overall conversion efficiency. Thus, the entire device achieves comprehensive improvements in cost, energy efficiency, space utilization, and reliability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a transformer according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of a transformer according to another embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a multi-channel high-voltage input source network competing for power supply according to the first embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of a multi-channel high-voltage input source network competing for power supply according to the second embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of a multi-channel high-voltage input source network competing for power supply according to the third embodiment of the present invention;

[0024] Figure 6 This is a circuit topology diagram of a transformer according to an embodiment of the present invention;

[0025] Figure 7 This is a simulation diagram of the output of a multi-channel high-voltage input source in standby / fault mode according to a specific example of the present invention;

[0026] Figure 8 This is a simulation diagram of the output of a multi-channel high-voltage input source in normal operation mode according to a specific example of the present invention;

[0027] Figure 9 This is a simulation diagram of the output of a multi-channel high-voltage input source in black-start mode according to a specific example of the present invention;

[0028] Figure 10 This is a simulation diagram of the energy storage stage of a transformer according to a specific example of the present invention;

[0029] Figure 11 This is a simulation diagram of the energy transmission stage of a transformer according to a specific example of the present invention. Detailed Implementation

[0030] 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.

[0031] Figure 1 This is a schematic diagram of the structure of a transformer according to an embodiment of the present invention, as shown below. Figure 1 As shown, the transformer includes: a multi-channel high-voltage input source network 1, a power aggregation BUS network 2, a low-side input winding network 3, a high-side input winding network 4, a PCB transformer network 5, and an output synchronous rectifier winding network 6.

[0032] Among them, the multi-channel high-voltage input source network 1 is used to provide multiple input source voltages, which compete for power supply. The input source voltages include AC voltage VAC, power module bus voltage VBUS, and battery voltage VBAT at different voltage levels. The power aggregation BUS network 2 is connected to the multi-channel high-voltage input source network 1 and is used to construct the virtual bus midpoint BUSN. The first input terminal of the low-side input winding network 3 is connected to the virtual bus midpoint BUSN, and the second input terminal of the low-side input winding network 3 is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network. The low-side input winding network 3 is used to transmit energy from the virtual bus midpoint BUSN to the negative output terminal BUS-. The high-side input... One end of the winding network 4 is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network, and the other end of the high-side input winding network 4 is connected to the virtual bus midpoint BUSN. The high-side input winding network 4 is used to transmit the energy source from the positive output terminal BUS+ to the virtual bus midpoint BUSN. The first primary winding of the PCB transformer network 5 is connected to the output terminal of the low-side input winding network 3, and the second primary winding is connected to the output terminal of the high-side input winding network 4. It is used to transmit the energy source output from the low-side input winding network 3 and the high-side input winding network 4 to the secondary winding. The output synchronous rectifier winding network 6 is connected to the secondary winding of the PCB transformer network 5. It is used to rectify the energy source received by the secondary winding and output it to the load R0.

[0033] Specifically, the AC voltage VAC, power module bus voltage VBUS, and battery voltage VBAT are the voltages of multiple high-voltage input sources. VAC is high-voltage AC, with a phase voltage level exceeding 1000VAC, providing energy during standby (when the power module is not working). VBUS is the high-voltage power module bus voltage, with a power module bus voltage level exceeding 2000VDC, providing energy during normal operation (when the power module is working). VBAT is the battery voltage, with a voltage level of approximately 500VDC, providing black-start functionality. The three input sources are rectified or cut off by diodes, with energy provided by the input source with the highest voltage at any given time. This constitutes a multi-input source competition power supply, achieving seamless switching of high-voltage multiple input sources over a wide range through this competitive power supply network, improving power supply reliability. The positive output terminal BUS+, the virtual bus midpoint BUSN, and the negative output terminal BUS- of the multi-high-voltage input source network are the energy collection points. By constructing a virtual BUSN, the bus voltage level of the power module is reduced by half, achieving decoupling of energy between the upper and lower bus levels. The low-side input winding network 3 and the high-side input winding network 4 form two flyback inputs that transfer energy to the load through the PCB transformer network 5. This significantly reduces the voltage stress on the primary-side switching transistors, resulting in lower overall device cost and a wider range of selectable switching transistors. The PCB transformer network 5 consists of the primary-side winding ( Figure 1 Taking two primary windings as an example, the secondary winding and the magnetic core together form a flyback transformer, thereby realizing energy transfer and voltage isolation between the primary and secondary sides. The output synchronous rectifier winding network 6 can synchronously rectify the energy source received by the secondary winding of the PCB transformer network 5 and output it to the load, which can reduce conduction losses and improve the overall conversion efficiency. As a result, the entire device is comprehensively improved in terms of cost, energy efficiency, space utilization and reliability.

[0034] In one embodiment of the present invention, such as Figure 2 As shown, the transformer described above may further include: a flyback control chip network 7, which is connected to the control terminals of the low-side input winding network 3 and the high-side input winding network 4. The flyback control chip network 7 is used to output a first control signal to the low-side input winding network 3 and the high-side input winding network 4, so that current flows from the virtual bus midpoint BUSN into the low-side input winding network 3 and from the positive output terminal BUS+ into the high-side input winding network 4, so as to charge and store energy in the first primary winding and the second primary winding of the PCB transformer network, respectively. The second control signal is also output to the low-side input winding network 3 and the high-side input winding network 4 to transfer the energy stored in the first primary winding and the second primary winding of the PCB transformer network to the secondary winding of the PCB transformer network 5.

[0035] Specifically, the flyback control chip network 7 outputs a signal that is passed through a drive transformer to generate two drive signals, which are simultaneously output to the low-side input winding network 3 and the high-side input winding network 4. When the flyback control chip network 7 outputs a first control signal to the low-side input winding network 3 and the high-side input winding network 4, the low-side input winding network 3 and the high-side input winding network 4 are turned on. Current flows from the virtual bus midpoint BUSN into the low-side input winding network 3 to charge and store energy in the first primary winding of the PCB transformer network 5. At the same time, current flows from the positive output terminal BUS+ into the high-side input winding network 4 to charge and store energy in the second primary winding of the PCB transformer network 5, thus achieving energy storage. When the flyback control chip network 7 outputs the second control signal to the low-side input winding network 3 and the high-side input winding network 4, the low-side input winding network 3 and the high-side input winding network 4 are turned off. The sudden change in the resistive current of the low-side input winding network 3 and the high-side input winding network 4 reverses the polarity of the windings. The change in polarity of the first primary winding and the second primary winding of the PCB transformer network causes the polarity of the secondary winding to reverse. The PCB transformer transfers the energy stored in the first primary winding and the second primary winding to the secondary winding of the PCB transformer network, thus realizing energy transfer.

[0036] In one embodiment of the present invention, such as Figure 2 As shown, the transformer described above may further include: a primary-side auxiliary winding network 8 and a feedback network 9. One end of the primary-side auxiliary winding network 8 is connected to the third primary winding of the PCB transformer network, and the other end of the primary-side auxiliary winding network 8 is connected to the power supply terminal VIN and the virtual bus midpoint BUSN of the flyback control chip network 7, for providing power supply voltage to the flyback control chip network 7. The feedback network 9 is connected between the primary-side auxiliary winding network 8 and the voltage feedback terminal COMP of the flyback control chip network 7, for feeding back the power supply voltage to the flyback control chip network 7.

[0037] Specifically, the primary-side auxiliary winding network 8 provides power supply voltage to the flyback control chip network 7 and also serves as a voltage sample value fed into the feedback network 9. The feedback network 9 may include a resistor divider, a capacitor, and a reference voltage regulator to form a negative feedback network for feedback control of the output voltage signal.

[0038] In one embodiment of the present invention, such as Figure 3-5As shown, the multi-channel high-voltage input source network 1 may include: first to sixth bridge arms connected in parallel, each bridge arm consisting of two diodes connected in series. The midpoints of the first and second bridge arms are connected to the positive and negative terminals VAC+ and VAC- of the AC voltage, respectively. The midpoints of the second and third bridge arms are connected to the positive and negative terminals VBUS+ and VBUS- of the power module bus voltage, respectively. The midpoints of the fourth and fifth bridge arms are connected to the positive and negative terminals VBAT+ and VBAT- of the battery voltage, respectively. One end of the first to sixth bridge arms is connected to the anode of the first diode D1, and the cathode of the first diode serves as the positive output terminal BUS+ of the multi-channel high-voltage input source network. The other end of the first to sixth bridge arms is connected to the cathode of the second diode D2, and the anode of the second diode D2 serves as the negative output terminal BUS- of the multi-channel high-voltage input source network.

[0039] Specifically, for input source contention in a multi-channel high-voltage input source network, see [link to relevant documentation]. Figure 3-5 ,like Figure 3 As shown, when the system containing the transformer is in standby / fault mode, the power module does not work, the power module bus voltage VBUS has no output, and VAC (1000VAC) and VBAT (500VDC) compete for the output. The input source is the rectified value of VAC. Figure 4 As shown, when the system containing the transformer is in normal operating mode, the power module operates, and VAC (1000VAC), VBUS (2000VDC), and VBAT (500VDC) compete for output, while the input source is from the 2000VDC VBUS. Figure 5 As shown, when the system containing the transformer is in black-start mode, VAC and VBUS have no output, VBAT is in an off-grid state, and outputs 500VDC. Due to diode competition for output, the input source comes from the 500VDC VBAT. Therefore, multiple input sources such as AC voltage, BUS voltage, and battery voltage can be connected in parallel through diodes, enabling seamless switching of input sources to provide power to subsequent circuits. This avoids the need to design multiple flyback circuits to achieve output competition for power supply, simplifies circuit design, saves component costs, and improves circuit reliability. The diodes used have high voltage ratings, low on-state current, are easy to select, and are low in cost.

[0040] In one embodiment of the present invention, such as Figure 3-5 As shown, the power aggregation BUS network 2 may include: a first capacitor C1 and a second capacitor C2. One end of the first capacitor C1 is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network; one end of the second capacitor C2 is connected to the other end of the first capacitor C1, and the connection point between the other end of the first capacitor C1 and one end of the second capacitor C2 serves as the virtual bus midpoint BUSN; the other end of the second capacitor C2 is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network.

[0041] In one embodiment of the present invention, such as Figure 3-5 As shown, the power collection BUS network 2 may also include: a high-voltage buck network 21, which includes a pre-start resistor R1 and a third diode D3. One end of the pre-start resistor R1 is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network, and the other end of the pre-start resistor R1 is connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the power supply terminal VIN of the flyback control chip network 7.

[0042] Specifically, BUS+, BUSN, and BUS- are the input source energy collection points, connected in series by two thin-film capacitors. By constructing a virtual bus midpoint BUSN, the bus voltage level of the BUS power module is reduced by half, achieving decoupling of the energy between the upper and lower BUS. Simultaneously, a high-voltage buck network generates a supply voltage to power the VIN terminal of the flyback control chip network 7.

[0043] In one embodiment of the present invention, such as Figure 6 As shown, the low-side input winding network 3 includes: a first magnetizing inductor Lm1, a first leakage inductance Lr1, a fourth diode D4, a first absorption network 31, and a first switching transistor S1.

[0044] Among them, the two ends of the first magnetizing inductor Lm1 are respectively connected to the two ends of the first primary winding; one end of the first leakage inductor Lr1 is connected to one end of the first magnetizing inductor Lm1; the anode of the fourth diode D4 is connected to the other end of the first leakage inductor Lr1, and the cathode of the fourth diode D4 is connected to the midpoint BUSN of the virtual bus; one end of the first absorption network 31 is connected to the other end of the first leakage inductor Lr1, and the other end of the first absorption network 31 is connected to the other end of the first magnetizing inductor Lm1; the first end of the first switch S1 is connected to the other end of the first magnetizing inductor Lm1, the second end of the first switch S1 is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network, and the control terminal of the first switch S1 is connected to the flyback control chip network 7.

[0045] Specifically, a low-side current transformer (CT) can also be set in the low-side input winding network 3. The low-side current transformer (CT) samples the peak current of the low-side primary side through the turns ratio. The first switch S1 can be a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) switch (including a parasitic diode and capacitor). The first absorption network 31 (including an absorption resistor, an absorption capacitor, and a diode) is used to suppress voltage spikes. The low-side input winding network 3 transfers energy to the secondary side of the BUS-energy source through the BUSN.

[0046] In one embodiment of the present invention, such as Figure 6As shown, the high-side input winding network 4 includes: a second magnetizing inductor Lm2, a second leakage inductance Lr2, a fifth diode D5, a second absorption network 41, and a second switching transistor S2.

[0047] Among them, the two ends of the second magnetizing inductor Lm2 are respectively connected to the two ends of the second primary winding; one end of the second leakage inductor Lr2 is connected to one end of the second magnetizing inductor Lm2; the anode of the fifth diode D5 is connected to the other end of the second leakage inductor Lr2, and the cathode of the fifth diode D5 is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network; one end of the second absorption network 41 is connected to the other end of the second leakage inductor Lr2, and the other end of the second absorption network D5 is connected to the other end of the second magnetizing inductor Lm2; the first end of the second switch S2 is connected to the other end of the second magnetizing inductor Lm2, the second end of the second switch S2 is connected to the virtual bus midpoint BUSN through the current sampling network 42, and the control terminal of the second switch S2 is connected to the flyback control chip network 7.

[0048] Specifically, the values ​​sampled by the current sampling network 42 and the low-side current transformer CT of the low-side input winding network 3 are used to sample the primary-side peak current through competition. The second switch S2 can be a MOSFET switch (including a parasitic diode and capacitor). At the same time, the second absorption network 41 (absorption resistor, absorption capacitor and diode) is used to suppress voltage spikes. The current sampling network 42 sends the flyback high and low-side primary winding current to the CS pin of the flyback control chip network 7 through the diode to realize peak current control at any time. The high-side input winding network 4 transfers energy to the secondary side through the BUSN energy source via BUS+.

[0049] In one embodiment of the present invention, such as Figure 6 As shown, the output synchronous rectification winding network 6 may include: a third switch S3, a third snubber network 61, a third capacitor C3, and a synchronous rectification control chip 62. The first terminal of the third switch S3 is connected to one end of the secondary winding of the PCB transformer network 5; the third snubber network 61 is connected between the first and second terminals of the third switch S3; one end of the third capacitor C3 is connected to the second terminal of the third switch S3, and the other end of the third capacitor C3 is connected to the other end of the secondary winding of the PCB transformer network 5. The two ends of the third capacitor C3 serve as the output terminals of the transformer and are connected in parallel with the load R0; the synchronous rectification control chip 62 is connected to the control terminal of the third switch S3, and the synchronous rectification control chip 62 is used to output a control signal to the control terminal of the third switch S3 based on the voltage signal between the first and second terminals of the third switch S3. The third switch S3 can be a MOSFET. Therefore, using synchronous rectification at the output reduces conduction losses and improves overall conversion efficiency.

[0050] Specifically, when the flyback control chip network 7 controls the first switch S1 and the second switch S2 to conduct, a loop is formed from BUSN→D4→Lr1→Lm1→S1→BUS-, and current flows from BUSN to the BUS- side, storing energy in the low-side input winding network 3. Simultaneously, a loop is formed from BUS+→D5→Lr2→Lm2→S2→BUSN, and current flows from BUS+ to the BUSN side, storing energy in the high-side input winding network 4. These two paths charge and store energy in the first and second primary windings of the PCB transformer network 5, respectively, thus performing energy storage. During this period, because the output-side switches are reverse-biased, no current flows in the secondary winding, and the load R0 demand is supplied by the third capacitor C3.

[0051] When the flyback control chip network 7 controls the first switch S1 and the second switch S2 to turn off, the BUS-low-side input winding will resist sudden changes in current and reverse the polarity of the winding. Simultaneously, the low-side input winding network 3 will resist sudden changes in current and reverse the polarity of the winding. The change in polarity of the primary winding of the PCB transformer network causes a reversal in the polarity of the secondary winding, which will result in forward bias of S3. Current flows through the secondary winding of the PCB transformer network. When the drain-source voltage drop of the third switch S3 reaches the conduction threshold, the drive signal for the output third switch S3 begins to drive it, and the current in the output synchronous rectifier winding network flows through the third switch S3. This avoids the problem of high losses due to large voltage drops in the rectifier diodes. The energy stored in the first and second primary windings will be transferred to the load R0 through the third switch S3, thus performing energy transfer. During this period, the output third capacitor C3 will replenish its charge.

[0052] To more clearly describe the effect of the transformer described above in this invention, a detailed simulation will be performed below based on the circuit scheme described above:

[0053] See the simulation diagram for the input source contention stage. Figure 7-9 , Figure 7 This is a simulation diagram of the output of the multi-channel high-voltage input source in standby / fault mode; Figure 8 This is a simulation diagram of the output of a multi-channel high-voltage input source during normal operation. Figure 9 This is a simulation diagram of the output of multiple high-voltage input sources in black start mode. Figure 7-9 In the figure, the horizontal axis represents time, and the vertical axis from top to bottom are: VBUS_total, VBUS, VBAT, VAC, and Vout_ARM. VBUS_total is the total BUS voltage, and Vout_ARM (12V) is the flyback output voltage.

[0054] from Figure 7-9 It can be seen that in different modes, multiple input sources will compete for output, thereby ensuring that the auxiliary input source will continuously provide energy and guarantee the energy supply to the load.

[0055] Figure 10 This is a simulation diagram of the energy storage stage of a transformer. Figure 10 In the graph, the horizontal axis represents time, and the vertical axis, from top to bottom, represents: Ids_H, Vds_H, Vg_L, Vg_h, Ids_L, Vds_L. Here, Ids_H is the peak current of the high-side input winding network, Vds_H is the drain-source voltage of the high-side input winding network, Vg_L is the drive voltage of the low-side input winding network, Vg_h is the drive voltage of the high-side input winding network, Ids_L is the peak current of the low-side input winding network, and Vds_L is the drain-source voltage of the low-side input winding network. Figure 10 It can be seen that the dual-winding architecture of the primary side of the PCB transformer, along with the construction of a virtual bus midpoint BUSN, allows the switching transistor on the flyback input side to bear only half of the BUS voltage stress, while the energy stored in the winding is doubled. This is suitable for the application of high voltage and low current in the primary winding and is more friendly to the working state of the switching devices.

[0056] Figure 11 This is a simulation diagram of the energy transfer stage of a transformer. Figure 11 The horizontal axis represents time, and the vertical axis from top to bottom is as follows: VBUS_P, VBUS_N, VBUS, VBAT, VAC, Vout_ARM (12V). VBUS_P is the input voltage of the high-side input winding network, VBUS_N is the input voltage of the low-side input winding network, VBUS is the power module bus voltage, VBAT is the battery voltage, VAC is the AC voltage, and Vout_ARM (12V) is the flyback output voltage.

[0057] from Figure 11 As can be seen, with multiple input sources, the one with the highest voltage provides energy. The wide-range high-voltage multi-input transformer of this invention has a stable output voltage and low ripple voltage, thereby providing energy to the downstream load.

[0058] In summary, the transformer according to the embodiments of the present invention achieves seamless switching of multiple high-voltage input sources over a wide range through competitive power supply via a multi-channel high-voltage input source network, thereby improving power supply reliability. The use of a PCB transformer offers high efficiency, high space utilization, and simple peripheral circuitry, achieving high efficiency and high integration while ensuring power rating. By constructing a virtual bus midpoint and employing a primary-side dual-winding structure to form two flyback inputs, the voltage stress on the primary-side switching transistors is significantly reduced, resulting in lower overall device cost and a wider selection of switching transistors. Synchronous rectification at the output reduces conduction losses and improves overall conversion efficiency. Therefore, the entire device achieves comprehensive improvements in cost, energy efficiency, space utilization, and reliability.

[0059] In the description of this invention, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A transformer, characterized in that, include: A multi-channel high-voltage input source network is used to provide multiple input source voltages, which compete for power supply. The input source voltages include AC voltages of different voltage levels, power module bus voltages, and battery voltages. A power aggregation BUS network is connected to the multi-channel high-voltage input source network. The power aggregation BUS network is used to construct a virtual bus midpoint (BUSN). A low-side input winding network, wherein the first input terminal of the low-side input winding network is connected to the virtual bus midpoint BUSN, and the second input terminal of the low-side input winding network is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network. The low-side input winding network is used to transmit the energy source from the virtual bus midpoint BUSN to the negative output terminal BUS-. A high-side input winding network, one end of which is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network, and the other end of which is connected to the virtual bus midpoint BUSN. The high-side input winding network is used to transmit the energy source from the positive output terminal BUS+ to the virtual bus midpoint BUSN. A PCB transformer network, wherein the first primary winding of the PCB transformer network is connected to the output terminal of the low-side input winding network and the second primary winding is connected to the output terminal of the high-side input winding network, for transmitting the energy source output by the low-side input winding network and the high-side input winding network to the secondary winding; An output synchronous rectifier winding network is provided, which is connected to the secondary winding of the PCB transformer network, and is used to rectify the energy source received by the secondary winding and output it to the load.

2. The transformer according to claim 1, characterized in that, Also includes: A flyback control chip network, connected to the control terminals of the low-side input winding network and the high-side input winding network, is used to output a first control signal to the low-side input winding network and the high-side input winding network, so that current flows from the virtual bus midpoint BUSN into the low-side input winding network and from the positive output terminal BUS+ into the high-side input winding network, respectively, to charge and store energy in the first primary winding and the second primary winding of the PCB transformer network, and to output a second control signal to the low-side input winding network and the high-side input winding network, so as to transfer the energy stored in the first primary winding and the second primary winding of the PCB transformer network to the secondary winding of the PCB transformer network.

3. The transformer according to claim 2, characterized in that, Also includes: A primary-side auxiliary winding network, one end of which is connected to the third primary winding of the PCB transformer network, and the other end of which is connected to the power supply terminal of the flyback control chip network and the virtual bus midpoint BUSN, for providing power supply voltage to the flyback control chip network. A feedback network is connected between the voltage feedback terminal of the primary-side auxiliary winding network and the flyback control chip network, and is used to feed the power supply voltage back to the flyback control chip network.

4. The transformer according to claim 1, characterized in that, The multi-channel high-voltage input source network includes: The first to sixth bridge arms are connected in parallel. Each bridge arm consists of two diodes connected in series. The midpoints of the first and second bridge arms are connected to the positive and negative terminals of the AC voltage, respectively. The midpoints of the second and third bridge arms are connected to the positive and negative terminals of the power module bus voltage, respectively. The midpoints of the fourth and fifth bridge arms are connected to the positive and negative terminals of the battery voltage, respectively. One end of the first to sixth bridge arms is connected to the anode of the first diode. The cathode of the first diode serves as the positive output terminal BUS+ of the multi-channel high-voltage input source network. The other end of the first to sixth bridge arms is connected to the cathode of the second diode. The anode of the second diode serves as the negative output terminal BUS- of the multi-channel high-voltage input source network.

5. The transformer according to claim 2, characterized in that, The power aggregation bus network includes: The first capacitor, one end of which is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network; The second capacitor has one end connected to the other end of the first capacitor, and the connection point between the other end of the first capacitor and one end of the second capacitor serves as the midpoint BUSN of the virtual bus. The other end of the second capacitor is connected to the negative output terminal BUS- of the multi-channel high-voltage input source network.

6. The transformer according to claim 5, characterized in that, The power-aggregating bus network also includes: A high-voltage step-down network is provided, comprising a pre-start resistor and a third diode. One end of the pre-start resistor is connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network, and the other end of the pre-start resistor is connected to the anode of the third diode. The cathode of the third diode is connected to the power supply terminal of the flyback control chip network.

7. The transformer according to claim 2, characterized in that, The low-side input winding network includes: The first magnetizing inductor has its two ends connected to the two ends of the first primary winding, respectively. The first leakage inductance, one end of which is connected to one end of the first magnetizing inductance; The fourth diode has its anode connected to the other end of the first leakage inductor and its cathode connected to the midpoint BUSN of the virtual busbar. A first absorption network, one end of which is connected to the other end of the first leakage inductor, and the other end of which is connected to the other end of the first magnetizing inductor. The first switching transistor has its first end connected to the other end of the first magnetizing inductor, its second end connected to the negative output terminal BUS- of the multi-channel high-voltage input source network, and its control terminal connected to the flyback control chip network.

8. The transformer according to claim 2, characterized in that, The high-side input winding network includes: The second magnetizing inductor has its two ends connected to the two ends of the second primary winding, respectively. The second leakage inductor is connected at one end to the second magnetizing inductor. The fifth diode has its anode connected to the other end of the second leakage inductor and its cathode connected to the positive output terminal BUS+ of the multi-channel high-voltage input source network. A second absorption network, one end of which is connected to the other end of the second leakage inductance, and the other end of which is connected to the other end of the second magnetizing inductance; The second switch has its first end connected to the other end of the second magnetizing inductor, and its second end connected to the virtual bus midpoint BUSN through a current sampling network. The control terminal of the second switch is connected to the flyback control chip network.

9. The transformer according to claim 2, characterized in that, The output synchronous rectifier winding network includes: The third switch is connected at one end to one end of the secondary winding of the PCB transformer network. A third absorption network is connected between the first and second ends of the third switching transistor. The third capacitor has one end connected to the second end of the third switching transistor, and the other end connected to the other end of the secondary winding of the PCB transformer network. The two ends of the third capacitor are connected in parallel with the load as the output terminals of the transformer. A synchronous rectification control chip is provided, which is connected to the control terminal of the third switching transistor. The synchronous rectification control chip is used to output a control signal to the control terminal of the third switching transistor based on the voltage signal between the first terminal and the second terminal of the third switching transistor.

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