An isolated AC-DC rectifier and high-voltage rectifier system

Abstract

This application provides an isolated AC-DC rectifier and a high-voltage rectifier system. The rectifier includes a DC output port, a high-frequency isolation transformer module, a second rectifier module, L groups of AC input ports, and L first conversion units. In the j-th first conversion unit, the first conversion unit includes a switching assembly, a first rectifier module, and an inverter module. The switching assembly controls the connection or disconnection of the j-th group of AC input ports with the first rectifier module. The first rectifier module outputs a pulsating DC voltage. The output terminal of the inverter module is electrically connected to the j-th group of input terminals of the high-frequency isolation transformer module. The output terminal of the high-frequency isolation transformer module is electrically connected to the input terminal of the second rectifier module. The output terminal of the second rectifier module is electrically connected to the DC output port. The device and system employ single-stage conversion, resulting in high energy efficiency, high power density, and facilitate standardized configuration, while also improving grid adaptability and voltage compatibility.

Description

Technical Field

[0001] This application relates to the field of power electronic conversion and power supply technology, and in particular to an isolated AC-DC rectifier and a high-voltage rectifier system. Background Technology

[0002] With the rapid development of artificial intelligence and big data technologies, AI data centers have experienced explosive growth. Compared with traditional data centers, AI data centers deploy a large number of high-power-density AI servers, liquid-cooled cabinets, and other equipment, placing stringent requirements on the energy efficiency, power density, operational stability, and PUE (Power Usage Effectiveness) of the power supply and distribution system. Traditional power supply and distribution architectures are no longer adequate to meet their development needs.

[0003] The traditional multi-stage conversion power distribution architecture widely used in current artificial intelligence data centers is the closest existing technology to this invention. Its core consists of a power frequency transformer, a low-voltage AC-DC rectifier module, and a terminal DC-DC converter module. The working process is as follows: the 10kV medium-voltage AC power from the power grid is stepped down to about 400V by the power frequency transformer, and then rectified into low-voltage DC power by AC-DC. For IT equipment with 800V high-voltage DC power supply, a DC-DC boost module is also required to complete the power supply.

[0004] The existing technology has many drawbacks: First, multi-stage energy conversion leads to low energy efficiency and high PUE, making it difficult to improve system energy efficiency and inconsistent with the green development orientation; second, the power frequency transformer is bulky, has low power density, and occupies a lot of space, which contradicts the high-density deployment requirements of artificial intelligence data centers; third, the compatibility of each conversion unit is poor, the degree of standardization is low, the operation and maintenance are difficult, and the reliability is poor; fourth, the grid adaptability is weak, it cannot independently adjust active and reactive power, and it is difficult to integrate distributed energy sources such as energy storage and photovoltaics; fifth, the voltage adaptability is poor, requiring the addition of a DC-DC conversion stage, which increases the system complexity and end-point losses. Summary of the Invention

[0005] This application discloses an isolated AC-DC rectifier and a high-voltage rectifier system, aiming to provide an isolated AC-DC rectifier and a high-voltage rectifier system that adopts a single-stage conversion, has high energy efficiency and power density, is conducive to standardized configuration, and can improve grid adaptability and voltage compatibility.

[0006] To achieve the above objectives, this application discloses an isolated AC-DC rectifier device, including a DC output port, a high-frequency isolation transformer module, a second rectifier module, L sets of AC input ports, and L first conversion units;

[0007] In the j-th first conversion unit, the first conversion unit includes a switching component, a first rectifier module, and an inverter module. The AC input port includes a first AC input port and a second AC input port. The switching component is electrically connected between the first AC input port and the second AC input port in the j-th group of AC input ports. The j-th group of AC input ports, the first rectifier module, and the inverter module are sequentially electrically connected. The switching component is used to control the j-th group of AC input ports to be connected to or blocked from the first rectifier module. The first rectifier module outputs a pulsating DC voltage. The output terminal of the inverter module is electrically connected to the j-th group of input terminals of the high-frequency isolation transformer module. The output terminal of the high-frequency isolation transformer module is electrically connected to the input terminal of the second rectifier module. The output terminal of the second rectifier module is electrically connected to the DC output port.

[0008] Where j is any integer from 1 to L.

[0009] In some embodiments, in the j-th first conversion unit, the switching component includes a first switching module and a second switching module. The second end of the first switching module is electrically connected to the first end of the second switching module. The first end of the first switching module is electrically connected to the first AC input port. The second end of the second switching module is electrically connected to the second AC input port. The switching component can be bidirectionally turned on or off to control the j-th group of AC input ports to be connected or blocked from the first rectifier module.

[0010] In some embodiments, the high-frequency isolation transformer module includes a secondary winding and L primary windings, wherein the first end of the j-th primary winding is electrically connected to the first output end of the inverter module in the j-th first conversion unit, and the second end of the j-th primary winding is electrically connected to the second output end of the inverter module in the j-th first conversion unit.

[0011] The first end of the secondary winding is electrically connected to the first input terminal of the second rectifier module, and the second end of the secondary winding is electrically connected to the second input terminal of the second rectifier module.

[0012] The L primary windings are magnetically coupled to the secondary windings, thereby coupling the L-phase high-frequency AC voltage output from the L first conversion units to output the converted high-frequency AC voltage.

[0013] In some embodiments, the first rectifier module includes a first single-phase bridge uncontrolled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module includes a second single-phase bridge uncontrolled rectifier circuit.

[0014] In the j-th first conversion unit, the first input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports; the second input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports; the first output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit; the second output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit; the first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding; and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding.

[0015] The first input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first terminal of the secondary winding, and the second input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second terminal of the secondary winding. The DC output port includes a first DC output port and a second DC output port. The first output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first DC output port, and the second output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second DC output port.

[0016] In some embodiments, the first rectifier module includes a first single-phase bridge fully controlled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module includes a second single-phase bridge fully controlled rectifier circuit.

[0017] In the j-th first conversion unit, the first input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports; the second input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports; the first output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit; the second output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit; the first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding; and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding.

[0018] The first input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first terminal of the secondary winding, and the second input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second terminal of the secondary winding. The DC output port includes a first DC output port and a second DC output port. The first output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first DC output port, and the second output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second DC output port.

[0019] In some embodiments, the device includes a first capacitor, a first terminal of which is electrically connected to a first output terminal of the second rectifier module, and a second terminal of which is electrically connected to a second output terminal of the second rectifier module.

[0020] In some embodiments, the device includes a second capacitor and a third capacitor, the second capacitor and the third capacitor being connected in series and then in parallel between the first output terminal and the second output terminal of the second rectifier module; the secondary winding is provided with a center tap, and the connection point of the second capacitor and the third capacitor is electrically connected to the center tap.

[0021] Secondly, this application provides a high-voltage rectification system, which includes a three-phase input terminal, namely an A-phase input terminal, a B-phase input terminal and a C-phase input terminal, wherein the number of each of the A-phase input terminal, the B-phase input terminal and the C-phase input terminal is set to two.

[0022] M isolated AC-DC rectifiers, each of which includes three first conversion units. In the three first conversion units of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit are respectively set as Ai+ input port and Ai- input port; the first AC input port and the second AC input port of the second first conversion unit are respectively set as Bi+ input port and Bi- input port; the first AC input port and the second AC input port of the third first conversion unit are respectively set as Ci+ input port and Ci- input port; the Ai- input port is electrically connected to the A(i+1)+ input port; the AM- input port is electrically connected to one of the two A-phase input terminals; the Bi- input port is electrically connected to the B(i+1)+ input port; the BM- input port is electrically connected to one of the two B-phase input terminals; the Ci- input port is electrically connected to the C(i+1)+ input port; and the CM- input port is electrically connected to one of the two C-phase input terminals.

[0023] Three inductors, including an A-phase inductor, a B-phase inductor, and a C-phase inductor, wherein the other A-phase input terminal of the two A-phase input terminals is electrically connected to A1+ through the A-phase inductor, the other B-phase input terminal of the two B-phase input terminals is electrically connected to B1+ through the B-phase inductor, and the other C-phase input terminal of the two C-phase input terminals is electrically connected to C1+ through the C-phase inductor;

[0024] Where i is any integer from 1 to M, the DC output port of the isolated AC-DC rectifier includes a first DC output port and a second DC output port, M first DC output ports are electrically connected and the connection node constitutes the first system DC output terminal, and M second DC output ports of the isolated AC-DC rectifier are electrically connected and the connection node constitutes the second system DC output terminal.

[0025] In some embodiments, the system includes:

[0026] Three-phase input terminals and N input terminal, wherein the three-phase input terminals include A-phase input terminal, B-phase input terminal and C-phase input terminal;

[0027] M isolated AC-DC rectifiers, each of which includes three first conversion units. In the three first conversion units of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit are respectively set as Ai+ input port and Ai- input port, the first AC input port and the second AC input port of the second first conversion unit are respectively set as Bi+ input port and Bi- input port, and the first AC input port and the second AC input port of the third first conversion unit are respectively set as Ci+ input port and Ci- input port. The Ai- input port is electrically connected to the A(i+1)+ input port, the AM- input port is electrically connected to the N input terminal, the Bi- input port is electrically connected to the B(i+1)+ input port, the BM- input port is electrically connected to the N input terminal, the Ci- input port is electrically connected to the C(i+1)+ input port, and the CM- input port is electrically connected to the N input terminal.

[0028] Three inductors, including phase A inductor, phase B inductor and phase C inductor, the phase A input terminal is electrically connected to A1+ through phase A inductor, the phase B input terminal is electrically connected to B1+ through phase B inductor, and the phase C input terminal is electrically connected to C1+ through phase C inductor;

[0029] Where i is any integer from 1 to M, the DC output port of the isolated AC-DC rectifier includes a first DC output port and a second DC output port, M first DC output ports are electrically connected and the connection node constitutes the first system DC output terminal, and M second DC output ports of the isolated AC-DC rectifier are electrically connected and the connection node constitutes the second system DC output terminal.

[0030] In some embodiments, the switching assembly includes a first operating mode and a second operating mode;

[0031] When the switching components are operating in the first operating mode, in the M isolated AC-DC rectifiers, all switching components of at least one phase are turned on to store energy in the corresponding inductor on the path, or all switching components of the M isolated AC-DC rectifiers are turned off to control the corresponding AC input port to be connected to the first rectifier module.

[0032] When the switching components are operating in the second operating mode, all switching components in the faulty isolated AC-DC rectifier are turned on to control the corresponding AC input port to block the first rectifier module.

[0033] Compared with the prior art, the beneficial effects of this application are as follows:

[0034] Firstly, the isolated AC-DC rectifier in this application adopts a single-stage power conversion architecture. The power frequency AC voltage is output as a pulsating DC voltage by the first rectifier module. This pulsating DC voltage is directly fed into the inverter module and inverted into a high-frequency AC voltage. Then, it is magnetically coupled to the second rectifier module via a high-frequency isolated transformer module. After rectification by the second rectifier module, a DC voltage is output. The first rectifier module and the inverter module constitute an energy transmission channel without intermediate DC energy storage. The power is transferred in real time throughout the conversion process without intermediate energy storage, avoiding the energy storage loss and volume occupation of the DC bus capacitor in traditional two-stage converters, and significantly improving the system's energy efficiency and power density.

[0035] By setting up L first conversion units and sharing a high-frequency isolation transformer module and a second rectifier module, modularity is achieved and scalability is improved. The number L of first conversion units can be flexibly configured according to the target power level to adapt to different power requirements. When L≥2, the L first conversion units sharing the second rectifier module further improves power density; L sets of AC input ports can connect to different phases of the AC power supply, providing strong input adaptability. If a single first conversion unit fails, the remaining first conversion units can still operate normally. In addition, the collaborative operation of multiple first conversion units can reduce the DC voltage ripple output from the DC output port.

[0036] Secondly, cascading the aforementioned isolated AC-DC rectifiers into a high-voltage rectifier system enables energy collection from three-phase inputs, significantly improving the withstand voltage level and system power capacity. The M first DC output ports are electrically connected, and their connection nodes constitute the first system's DC output terminal. The M second DC output ports of the isolated AC-DC rectifiers are electrically connected, and their connection nodes constitute the second system's DC output terminal. This reduces the system's output voltage ripple. Even if any one of the devices fails, the remaining devices can continue to supply power to the load without system shutdown, thus significantly improving power supply reliability. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the isolated AC-DC rectifier device of this application;

[0039] Figure 2 This is a circuit diagram of an embodiment of the isolated AC-DC rectifier device of this application;

[0040] Figure 3 This is a circuit diagram of yet another embodiment of the isolated AC-DC rectifier device of this application;

[0041] Figure 4 This is a circuit diagram of another embodiment of the isolated AC-DC rectifier device of this application;

[0042] Figure 5 This is a schematic diagram of an embodiment of the high-voltage rectification system of this application;

[0043] Figure 6 This is a schematic diagram of yet another embodiment of the high-voltage rectifier system of this application;

[0044] Figure 7 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with the number of the first conversion units set to three and a three-phase four-wire connection.

[0045] Figure 8 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with the number of the first conversion units set to three and a three-phase three-wire connection.

[0046] Figure 9 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with phase A representing mode one;

[0047] Figure 10 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with phase A representing mode two;

[0048] Figure 11 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with phase A representing mode three;

[0049] Figure 12 This is a schematic diagram of the isolated AC-DC rectifier device of this application used alone, with phase A representing mode four;

[0050] Figure 13 This is a schematic diagram of the switching assembly of the isolated AC-DC rectifier of this application in the first operating mode;

[0051] in, Figure 9-13 The red lines in the diagram are used to indicate the direction of current flow. Detailed Implementation

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0055] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0056] It should be noted that the terms "first, second, third" used in the embodiments of this application are used to distinguish similar or different objects and do not represent a specific order of objects. It can be understood that "first, second, third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0057] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "at least two" means two or more.

[0058] like Figure 1-13 As shown, in order to achieve the above objectives, this application discloses an isolated AC-DC rectifier and a high-voltage rectifier system.

[0059] In a first aspect, this application provides an isolated AC-DC rectifier device, which includes a DC output port, a high-frequency isolation transformer module 2, a second rectifier module 3, L groups of AC input ports, and L first conversion units 1; in the j-th first conversion unit 1, the first conversion unit 1 includes a switching assembly, a first rectifier module, and an inverter module, and each group of AC input ports includes a first AC input port and a second AC input port. The switching assembly is electrically connected between the first AC input port and the second AC input port in the j-th group of AC input ports. The j-th group of AC input ports, the first rectifier module, and the inverter module are sequentially electrically connected. The switching assembly is used to control the j-th group of AC input ports to be connected or disconnected from the first rectifier module. The first rectifier module outputs a pulsating DC voltage. The output terminal of the inverter module is electrically connected to the j-th group of input terminals of the high-frequency isolation transformer module 2. The output terminal of the high-frequency isolation transformer module 2 is electrically connected to the input terminal of the second rectifier module 3. The output terminal of the second rectifier module 3 is electrically connected to the DC output port; wherein, j is any integer from 1 to L.

[0060] In some embodiments, the isolated AC-DC rectifier can be used independently, that is, power is supplied to the downstream load through one isolated AC-DC rectifier. It can be understood that L first conversion units 1 correspond to L phase input AC voltages, and a set of AC input ports is used to connect to one phase input AC voltage. The phase difference between the AC voltages input to each phase is set according to the actual situation; preferably, the phase difference between two adjacent phases is 360° / L. In some embodiments, a three-phase four-wire connection can be used. Taking L=3 as an example, that is, three first conversion units are set, and the three first conversion units 1 are respectively connected to the corresponding AC input ports. Phase A of the three-phase power supply is electrically connected to phase A through one input terminal of phase A. +The input ports are as follows: Phase B is electrically connected to the B+ input port through one input terminal of Phase B; Phase C is electrically connected to the C+ input port through one input terminal of Phase C; and the A-, B-, and C- input ports are all electrically connected to the N input terminal. It can be understood that the A+, B+, and C+ input ports are all first AC input ports, and the A-, B-, and C- input ports are all second AC input ports. It can also be understood that in some embodiments, a three-phase three-wire wiring system can be used, where each of the A, B, and C phases of the three-phase power supply is directly connected to its corresponding A+, B+, or C+ input port. That is, Phase A is connected to the A+ input port, Phase B is connected to the B+ input port, and Phase C is connected to the C+ input port. Simultaneously, the A- input port is electrically connected to Phase B through another input terminal of Phase B, the B- input port is electrically connected to Phase C through another input terminal of Phase C, and the C- input port is electrically connected to Phase A through another input terminal of Phase A. It should be noted that under normal operating conditions, the switching components of the isolated AC-DC rectifier switch back and forth between the on and off states, thereby controlling the input voltage of the isolated AC-DC converter module through current chopping. It can be understood that the three-phase power supply is a current source.

[0061] As can be seen, the isolated AC-DC converter module adopts a single-stage power conversion architecture. The first rectifier module outputs a pulsating DC voltage, and its output terminal is directly electrically connected to the input terminal of the inverter module. No capacitor for smoothing the DC voltage is provided between them. Furthermore, no capacitor for smoothing the DC voltage is provided on the side of the first rectifier module near the output terminal or on the side of the inverter module near the input terminal; that is, there is no DC bus capacitor. The power frequency AC voltage is directly output as a pulsating DC voltage by the first rectifier module. This pulsating DC voltage is directly fed into the inverter module and inverted into a high-frequency AC voltage. It is then magnetically coupled to the second rectifier module 3 via the high-frequency isolated transformer module 2. After rectification by the second rectifier module 3, a DC voltage is output. The entire conversion process involves real-time power transfer without intermediate energy storage, avoiding the energy storage loss and volume occupation of the DC bus capacitor in traditional two-stage converters, significantly improving system energy efficiency and power density.

[0062] As can be seen, by setting up L first conversion units 1 and sharing a high-frequency isolation transformer module 2 and a second rectifier module 3, modularity is achieved and scalability is improved. The number L of first conversion units 1 can be flexibly configured according to the target power level to adapt to different power requirements. When L≥2, the L first conversion units sharing the second rectifier module 3 further improves power density; L sets of AC input ports can connect to different phases of the AC power supply, providing strong input adaptability. Even if a single first conversion unit 1 fails, the remaining first conversion units 1 can still operate normally. In addition, the collaborative operation of multiple first conversion units can reduce the DC voltage ripple output from the DC output port.

[0063] In some embodiments, in the j-th first conversion unit 1, the switching component includes a first switching module and a second switching module. The second end of the first switching module is electrically connected to the first end of the second switching module. The first end of the first switching module is electrically connected to the first AC input port. The second end of the second switching module is electrically connected to the second AC input port. The switching component can be bidirectionally turned on or off to control the j-th group of AC input ports to be connected or blocked from the first rectifier module.

[0064] It is understandable that the first and second switching modules are controllable switching modules, which can be fully controllable devices such as MOSFETs, insulated-gate bipolar transistors, or integrated gate commutated thyristors. The two switching modules are connected in reverse series, enabling the switching assembly to bidirectionally block voltage and conduct current, thus adapting to both the positive and negative half-cycles of the AC input. By controlling the on and off states of the two switching modules, the current flow between the AC input port and the first rectifier module can be controlled, thereby achieving bidirectional power flow.

[0065] In some embodiments, the first switching module and the second switching module are respectively a first MOSFET Q1 and a second MOSFET Q2, which are connected in reverse series. That is, the source of the first MOSFET Q1 is electrically connected to the source of the second MOSFET Q2, the drain of the first MOSFET Q1 is electrically connected to the first AC input port, and the drain of the second MOSFET Q2 is electrically connected to the second AC input port. By controlling the gates of the two MOSFETs, the switching assembly can be turned on or off in both the positive and negative half-cycles of AC, thereby bidirectionally blocking voltage or bidirectionally conducting current.

[0066] In some embodiments, the high-frequency isolation transformer module 2 includes a secondary winding T2 and L primary windings T1. The first end of the j-th primary winding T1 is electrically connected to the first output end of the inverter module in the j-th first conversion unit 1, and the second end of the j-th primary winding T1 is electrically connected to the second output end of the inverter module in the j-th first conversion unit 1.

[0067] The first end of the secondary winding T2 is electrically connected to the first input terminal of the second rectifier module 3, and the second end of the secondary winding T2 is electrically connected to the second input terminal of the second rectifier module 3.

[0068] L primary windings T1 are magnetically coupled to secondary windings T2, thereby coupling the L-phase high-frequency AC voltages output from the L first conversion units 1 to output the converted high-frequency AC voltage.

[0069] In some embodiments, the magnetic coupling in this application includes, but is not limited to, an implementation where at least two primary windings T1 and secondary winding T2 share a single iron core, or an implementation where each primary winding T1 has its own independent iron core, and the secondary winding T2 is connected to the output via an external circuit. It is understood that having multiple windings share a single magnetic circuit can significantly reduce the size and weight of the transformer, improve magnetic circuit utilization and power density, and simultaneously, the natural superposition of magnetic flux can improve the uniformity of the contribution of each primary winding T1 to the secondary output voltage, thereby mitigating the problem of uneven power distribution caused by inconsistent magnetic circuits.

[0070] In some embodiments, the first rectifier module includes a first single-phase bridge uncontrolled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module 3 includes a second single-phase bridge uncontrolled rectifier circuit; in the j-th first conversion unit 1, the first input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports, the second input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports, the first output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit, and the second output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit. The first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding T1, and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding T1; the first input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first terminal of the secondary winding T2, and the second input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second terminal of the secondary winding T2; the DC output ports include a first DC output port DC+ and a second DC output port DC-; the first output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first DC output port DC+, and the second output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second DC output port DC-.

[0071] Specifically, the first single-phase bridge uncontrolled rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is electrically connected to the cathode of the second diode D2, and the connection point constitutes the first input terminal of the first rectifier module. The anode of the third diode D3 is electrically connected to the cathode of the fourth diode D4, and the connection point constitutes the second input terminal of the first rectifier module. The cathode of the first diode D1 is electrically connected to the cathode of the third diode D3, and the connection point constitutes the first output terminal of the first rectifier module. The anode of the second diode D2 is electrically connected to the anode of the fourth diode D4, and the connection point constitutes the second output terminal of the first rectifier module. It is understood that in some embodiments, the first input terminal of the first single-phase bridge uncontrolled rectifier circuit is also the first input terminal of the first rectifier module, the second input terminal of the first single-phase bridge uncontrolled rectifier circuit is also the second input terminal of the first rectifier module, the first output terminal of the first single-phase bridge uncontrolled rectifier circuit is also the first output terminal of the first rectifier module, and the second output terminal of the first single-phase bridge uncontrolled rectifier circuit is also the second output terminal of the first rectifier module.

[0072] By setting the first rectifier module as a single-phase bridge uncontrolled rectifier circuit, the overall cost and control complexity of the device can be significantly reduced. There is no need to configure a drive circuit and isolation power supply for the rectifier side, which simplifies the structure of the first conversion unit 1.

[0073] It is understandable that when both the first and second switch modules are closed, both the first and second switch modules are conducting, thereby blocking the electrical connection between the AC input terminal and the first rectifier module. When both the first and second switch modules are open, both the first and second switch modules are turned off, and the current can flow from the AC input terminal to the first rectifier module.

[0074] In some embodiments, the single-phase full-bridge inverter circuit includes a third switch module, a fourth switch module, a fifth switch module, and a sixth switch module; the first terminal of the third switch module is electrically connected to the first terminal of the fifth switch module, and the connection point constitutes the first input terminal of the inverter module; the second terminal of the fourth switch module is electrically connected to the second terminal of the sixth switch module, and the connection point constitutes the second input terminal of the inverter module; the second terminal of the third switch module is electrically connected to the first terminal of the fourth switch module, and the connection point constitutes the second output terminal of the inverter module; the second terminal of the fifth switch module is electrically connected to the first terminal of the sixth switch module, and the connection point constitutes the first output terminal of the inverter module. It is understood that in some embodiments, the first input terminal of the single-phase full-bridge inverter circuit is also the first input terminal of the inverter module, the second input terminal of the single-phase full-bridge inverter circuit is also the second input terminal of the inverter module, the first output terminal of the single-phase full-bridge inverter circuit is also the first output terminal of the inverter module, and the second output terminal of the single-phase full-bridge inverter circuit is also the second output terminal of the inverter module.

[0075] In some embodiments, the inverter module includes a third MOSFET Q3, a fourth MOSFET Q4, a fifth MOSFET Q5, and a sixth MOSFET Q6; the drain of the third MOSFET Q3 is electrically connected to the drain of the fifth MOSFET Q5, and the connection point constitutes the first input terminal of the inverter module; the drain of the fourth MOSFET Q4 is electrically connected to the drain of the sixth MOSFET Q6, and the connection point constitutes the second input terminal of the inverter module; the source of the third MOSFET Q3 is electrically connected to the drain of the fourth MOSFET Q4, and the connection point constitutes the second output terminal of the inverter module; the source of the fifth MOSFET Q5 is electrically connected to the drain of the sixth MOSFET Q6, and the connection point constitutes the first output terminal of the inverter module.

[0076] It is understandable that by controlling the turn-on timing of the third to sixth switch modules, a high-frequency AC voltage is generated between the first and second output terminals of the inverter module, thereby converting the input pulsating DC voltage into a high-frequency AC voltage.

[0077] Specifically, the second single-phase bridge uncontrolled rectifier circuit includes a fifth diode D5, a sixth diode D6, a seventh diode D7, and an eighth diode D8. The anode of the fifth diode D5 is electrically connected to the cathode of the sixth diode D6, and the connection point constitutes the first input terminal of the second rectifier module 3. The anode of the seventh diode D7 is electrically connected to the cathode of the eighth diode D8, and the connection point constitutes the second input terminal of the second rectifier module 3. The cathode of the fifth diode D5 is electrically connected to the cathode of the seventh diode D7, and the connection point constitutes the first output terminal of the second rectifier module 3. The anode of the sixth diode D6 is electrically connected to the anode of the eighth diode D8, and the connection point constitutes the second output terminal of the second rectifier module 3. It is understood that in some embodiments, the first input terminal of the second single-phase bridge uncontrolled rectifier circuit is also the first input terminal of the second rectifier module, the second input terminal of the second single-phase bridge uncontrolled rectifier circuit is also the second input terminal of the second rectifier module, the first output terminal of the second single-phase bridge uncontrolled rectifier circuit is also the first output terminal of the second rectifier module, and the second output terminal of the second single-phase bridge uncontrolled rectifier circuit is also the second output terminal of the second rectifier module.

[0078] By setting the second rectifier module 3 as a single-phase bridge uncontrolled rectifier circuit, the overall cost and control complexity of the device can be significantly reduced. There is no need to configure a drive circuit and isolation power supply for the rectifier side, which simplifies the structure of the second rectifier module 3.

[0079] In some embodiments, the isolated AC-DC rectifier further includes a first capacitor C1, the first end of which is electrically connected to the first output terminal of the second rectifier module 3, and the second end of which is electrically connected to the second output terminal of the second rectifier module 3.

[0080] It is understandable that the first capacitor C1 is electrically connected between the first output terminal and the second output terminal of the second rectifier module 3 to filter out the high-frequency voltage ripple after rectification and smooth the output DC voltage, thereby providing a stable and low-ripple DC voltage for the load; at the same time, the capacitor can also provide transient energy support and improve the dynamic response capability of the system.

[0081] In some embodiments, the isolated AC-DC rectifier further includes a second capacitor C2 and a third capacitor C3. The second capacitor C2 and the third capacitor C3 are connected in series and electrically connected between the first output terminal and the second output terminal of the second rectifier module 3. The secondary winding T2 is provided with a center tap, and the connection point of the second capacitor C2 and the third capacitor C3 is electrically connected to the center tap.

[0082] The second capacitor C2, the third capacitor C3, and the center tap can form a common-mode filter path at the DC output terminal, effectively suppressing the common-mode interference coupled from the secondary winding T2 to the DC bus. At the same time, the center tap is connected to the midpoint of the capacitor, which helps to balance the voltage of the positive and negative DC buses, reduce output ripple, and improve DC power quality.

[0083] It should be noted that the power frequency AC power comes from the power grid. In some embodiments, the frequency of the power frequency AC power is 50Hz to 60Hz. The high-frequency AC power is generated by the inverter module. In some embodiments, the frequency of the high-frequency AC power is several kHz to hundreds of kHz. When there are three first conversion units 1, the three first conversion units 1 are connected to the corresponding phases of the three-phase power supply through corresponding first AC input ports. Taking one of the first conversion units 1 in an isolated AC-DC rectifier as an example, refer to... Figure 7-10 This describes four power supply modes in the isolated AC-DC rectifier device of the present invention when only one first conversion unit 1 is working and the AC input port is connected to phase A of a three-phase power supply. It should be noted that, for ease of explanation, Figure 7-10 The other two first conversion units and their corresponding primary coils L1 are omitted. The four modes are divided based on the polarity of the power frequency voltage, i.e., the instantaneous polarity of the power frequency AC power received at the AC input port, which is either the positive or negative half-cycle; and the polarity of the primary voltage of the high-frequency isolation transformer module 2, i.e., the direction of the high-frequency AC voltage generated by the inverter module, which is either the high-frequency positive or negative half-cycle. Different combinations of these two polarities constitute four typical operating modes.

[0084] Mode 1: Power frequency positive half-cycle, high frequency positive half-cycle. At this time, the switching components are off, and current flows from the A+ input port into the first diode D1 in the first rectifier module and the fifth MOSFET Q5 in the inverter module, flowing in the positive direction through the primary winding T1 of the high-frequency isolation transformer module 2, then through the fourth MOSFET Q4 in the inverter module, the fourth diode D4 in the first rectifier module, and the A- input port. The high-frequency AC current in the primary winding T1 is magnetically coupled to the secondary winding T2. The current generated by the high-frequency AC voltage output from the secondary winding T2 is converted into a positive DC voltage after passing through the fifth diode D5 in the second rectifier module 3. The current generated by this DC voltage returns to the secondary winding through the first DC output port DC+, the load, the second DC output port DC-, and the eighth diode D8 in the second rectifier module 3.

[0085] Mode 2: Power frequency positive half-cycle, high frequency negative half-cycle. When the switching components are off, current flows from the A+ input port into the first diode D1 in the first rectifier module and the third MOSFET Q3 in the inverter module. The inverter module causes the current to flow in the reverse direction through the primary winding T1 of the high-frequency isolation transformer module 2, then through the sixth MOSFET Q6 in the inverter module, the fourth diode D4 in the first rectifier module, and the A- input port. The high-frequency AC current in the primary winding T1 is magnetically coupled to the secondary winding T2. The current generated by the high-frequency AC voltage output from the secondary winding T2, after passing through the seventh diode D7 in the second rectifier module 3, still outputs a positive DC voltage. The current generated by this DC voltage returns to the secondary winding T2 through the first DC output port DC+, the load, the second DC output port DC-, and the sixth diode D6 in the second rectifier module 3.

[0086] Mode 3: Negative half-cycle of power frequency, positive half-cycle of high frequency. During the negative half-cycle of power frequency, the potential of the A+ input port is lower than that of the A- input port. The switching assembly is turned off. Current flows from the A- input port sequentially through the third diode D3 in the first rectifier module, the fifth MOSFET Q5 in the inverter module, and then flows in the positive direction through the primary winding T1 of the high-frequency isolation transformer module 2, and then through the fourth MOSFET Q4 in the inverter module, the second diode D2 in the first rectifier module, and the A+ input port. The high-frequency AC current in the primary winding T1 is magnetically coupled to the secondary winding T2. The current generated by the high-frequency AC voltage output from the secondary winding T2 is output as a positive DC voltage through the fifth diode D5 in the second rectifier module 3. The current generated by this DC voltage returns to the secondary winding T2 through the first DC output port DC+, the load, the second DC output port DC-, and the eighth diode D8 in the second rectifier module 3.

[0087] Mode 4: Power frequency negative half-cycle, high frequency negative half-cycle. When the switching assembly is off, current flows from the A- input port through the third diode D3 in the first rectifier module, the third MOSFET Q3 in the inverter module, and in the reverse direction through the primary winding T1 of the high-frequency isolation transformer module 2. It then flows through the sixth MOSFET Q6 in the inverter module, the second diode D2 in the first rectifier module, and the A+ input port. The high-frequency AC current in the primary winding T1 is magnetically coupled to the secondary winding T2. The current generated by the high-frequency AC voltage output from the secondary winding T2 passes through the seventh diode D7 in the second rectifier module 3 and outputs a positive DC voltage. The current generated by this DC voltage returns to the secondary winding T2 through the first DC output port DC+, the load, the second DC output port DC-, and the sixth diode D6 in the second rectifier module 3.

[0088] Understandably, regardless of whether the power frequency voltage is in the positive or negative half-cycle, and regardless of whether the inverter module outputs a high-frequency positive or negative half-cycle, as long as the switching components are turned off, the current can be transmitted to the DC output terminal through the continuous path formed by the first rectifier module, the inverter module, the high-frequency isolation transformer module 2, and the second rectifier module 3. The four modes alternately cover the entire power frequency cycle in time, and with the high-frequency PWM control, single-stage isolation boost and real-time power output can be achieved.

[0089] In some embodiments, the controller selects the optimal switching state and high-frequency direction in real time based on the instantaneous value of the three-phase input voltage, enabling the input current to follow the voltage waveform and achieving unity power factor operation while ensuring continuous and stable DC output. The switching frequency between different switching states is much higher than the power frequency, thereby ensuring sinusoidal input current and low ripple of the output DC voltage.

[0090] In some embodiments, the first rectifier module includes a first single-phase bridge fully controlled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module 3 includes a second single-phase bridge fully controlled rectifier circuit; in the j-th first conversion unit 1, the first input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports, the second input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports, the first output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit, and the second output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit. The first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding T1, and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding T1; the first input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first terminal of the secondary winding T2, and the second input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second terminal of the secondary winding T2; the DC output ports include a first DC output port DC+ and a second DC output port DC-; the first output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first DC output port DC+, and the second output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second DC output port DC-.

[0091] Specifically, the first single-phase bridge fully controlled rectifier circuit includes a seventh switch module, an eighth switch module, a ninth switch module, and a tenth switch module. The second terminal of the seventh switch module is electrically connected to the first terminal of the eighth switch module, and the connection point constitutes the first input terminal of the first rectifier module. The second terminal of the ninth switch module is electrically connected to the first terminal of the tenth switch module, and the connection point constitutes the second input terminal of the first rectifier module. The first terminal of the seventh switch module is electrically connected to the first terminal of the ninth switch module, and the connection point constitutes the first output terminal of the first rectifier module. The second terminal of the eighth switch module is electrically connected to the second terminal of the tenth switch module, and the connection point constitutes the second output terminal of the first rectifier module. It is understood that in some embodiments, the first input terminal of the first single-phase bridge fully controlled rectifier circuit is also the first input terminal of the first rectifier module, the second input terminal of the first single-phase bridge fully controlled rectifier circuit is also the second input terminal of the first rectifier module, the first output terminal of the first single-phase bridge fully controlled rectifier circuit is also the first output terminal of the first rectifier module, and the second output terminal of the first single-phase bridge fully controlled rectifier circuit is also the second output terminal of the first rectifier module.

[0092] Specifically, the second single-phase bridge fully controlled rectifier circuit includes an eleventh switch module, a twelfth switch module, a thirteenth switch module, and a fourteenth switch module. The second terminal of the eleventh switch module is electrically connected to the first terminal of the twelfth switch module, and the connection point constitutes the first input terminal of the second rectifier module 3. The second terminal of the thirteenth switch module is electrically connected to the first terminal of the fourteenth switch module, and the connection point constitutes the second input terminal of the second rectifier module 3. The first terminal of the eleventh switch module is electrically connected to the first terminal of the thirteenth switch module, and the connection point constitutes the first output terminal of the second rectifier module 3. The second terminal of the twelfth switch module is electrically connected to the second terminal of the fourteenth switch module, and the connection point constitutes the second output terminal of the second rectifier module 3. It is understood that in some embodiments, the first input terminal of the second single-phase bridge fully controlled rectifier circuit is also the first input terminal of the second rectifier module, the second input terminal of the second single-phase bridge fully controlled rectifier circuit is also the second input terminal of the second rectifier module, the first output terminal of the second single-phase bridge fully controlled rectifier circuit is also the first output terminal of the second rectifier module, and the second output terminal of the second single-phase bridge fully controlled rectifier circuit is also the second output terminal of the second rectifier module.

[0093] By setting both the first rectifier module and the second rectifier module 3 as single-phase bridge fully controlled rectifier circuits, i.e., active rectifier bridges composed of fully controlled switching devices, bidirectional energy flow can be achieved by adjusting the control logic. That is, when power flows from the AC side to the DC side, the first rectifier module operates in rectification mode, and the second rectifier module 3 operates in uncontrolled or synchronous rectification mode. When power needs to be fed back from the DC side to the AC side, the second rectifier module 3 operates in inverter mode, inverting the DC power into high-frequency AC current, which is then transmitted to the primary side via the high-frequency isolation transformer module 2. The first rectifier module operates in synchronous rectification mode, rectifying the high-frequency AC current into AC current to feed back to the grid.

[0094] In some embodiments, the first single-phase bridge fully controlled rectifier circuit includes a seventh MOSFET Q7, an eighth MOSFET Q8, a ninth MOSFET Q9, and a tenth MOSFET Q10. The source of the seventh MOSFET Q7 is electrically connected to the drain of the eighth MOSFET Q8, and the connection point constitutes the first input terminal of the first rectifier module; the source of the ninth MOSFET Q9 is electrically connected to the drain of the tenth MOSFET Q10, and the connection point constitutes the second input terminal of the first rectifier module; the drain of the seventh MOSFET Q7 is electrically connected to the drain of the ninth MOSFET Q9, and the connection point constitutes the first output terminal of the first rectifier module; the source of the eighth MOSFET Q8 is electrically connected to the source of the tenth MOSFET Q10, and the connection point constitutes the second output terminal of the first rectifier module.

[0095] The second single-phase bridge fully controlled rectifier circuit includes an eleventh MOSFET Q11, a twelfth MOSFET Q12, a thirteenth MOSFET Q13, and a fourteenth MOSFET Q14. The source of the eleventh MOSFET Q11 is electrically connected to the drain of the twelfth MOSFET Q12, and the connection point forms the first input terminal of the second rectifier module. The source of the thirteenth MOSFET Q13 is electrically connected to the drain of the fourteenth MOSFET Q14, and the connection point forms the second input terminal of the second rectifier module. The drain of the eleventh MOSFET Q11 is electrically connected to the drain of the thirteenth MOSFET Q13, and the connection point forms the first output terminal of the second rectifier module. The source of the twelfth MOSFET Q12 is electrically connected to the source of the fourteenth MOSFET Q14, and the connection point forms the second output terminal of the second rectifier module.

[0096] Secondly, this application discloses a high-voltage rectification system, which includes:

[0097] The three-phase input terminals include phase A, phase B, and phase C input terminals, with two phase A, two phase B, and two phase C input terminals.

[0098] M isolated AC-DC rectifiers, each of which includes three first conversion units 1. In the three first conversion units 1 of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit 1 are respectively set as Ai+ input port and Ai- input port, the first AC input port and the second AC input port of the second first conversion unit 1 are respectively set as Bi+ input port and Bi- input port, and the first AC input port and the second AC input port of the third first conversion unit 1 are respectively set as Ci+ input port and Ci- input port. The Ai- input port is electrically connected to the A(i+1)+ input port, the AM- input port is electrically connected to one of the two A-phase input terminals, the Bi- input port is electrically connected to the B(i+1)+ input port, the BM- input port is electrically connected to one of the two B-phase input terminals, the Ci- input port is electrically connected to the C(i+1)+ input port, and the CM- input port is electrically connected to one of the two C-phase input terminals.

[0099] Three inductors, including phase A inductor L1, phase B inductor L2, and phase C inductor L3. The other phase A input terminal is electrically connected to the A1+ input port through phase A inductor L1. The other phase B input terminal is electrically connected to the B1+ input port through phase B inductor L2. The other phase C input terminal is electrically connected to the C1+ input port through phase C inductor L3.

[0100] Where i is any integer from 1 to M, the DC output ports of the isolated AC-DC rectifier include a first DC output port DC+ and a second DC output port DC-, M first DC output ports DC+ are electrically connected and the connection nodes constitute the first system DC output terminal DC1+, and M second DC output ports DC- of the isolated AC-DC rectifier are electrically connected and the connection nodes constitute the second system DC output terminal DC1-.

[0101] Understandably, this system uses a three-phase three-wire connection method, which is suitable for power supply applications without a neutral wire. It can save on conductor materials, has a simple structure, and has low power transmission loss over long distances.

[0102] In some embodiments, the high-voltage rectifier system includes a three-phase input terminal and an N input terminal, wherein the three-phase input terminal includes an A-phase input terminal, a B-phase input terminal and a C-phase input terminal;

[0103] M isolated AC-DC rectifiers, each of which includes three first conversion units 1. In the three first conversion units 1 of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit 1 are respectively set as Ai+ input port and Ai- input port, the first AC input port and the second AC input port of the second first conversion unit 1 are respectively set as Bi+ input port and Bi- input port, and the first AC input port and the second AC input port of the third first conversion unit 1 are respectively set as Ci+ input port and Ci- input port. The Ai- input port is electrically connected to the A(i+1)+ input port, the AM- input port is electrically connected to the N input terminal, the Bi- input port is electrically connected to the B(i+1)+ input port, the BM- input port is electrically connected to the N input terminal, the Ci- input port is electrically connected to the C(i+1)+ input port, and the CM- input port is electrically connected to the N input terminal.

[0104] Three inductors, including phase A inductor L1, phase B inductor L2 and phase C inductor L3. The phase A input terminal is electrically connected to the A1+ input port through phase A inductor L1, the phase B input terminal is electrically connected to the B1+ input port through phase B inductor L2, and the phase C input terminal is electrically connected to the C1+ input port through phase C inductor L3.

[0105] Where i is any integer from 1 to M, the DC output ports of the isolated AC-DC rectifier include a first DC output port DC+ and a second DC output port DC-, M first DC output ports DC+ are electrically connected and the connection nodes constitute the first system DC output terminal DC1+, and M second DC output ports DC- of the isolated AC-DC rectifier are electrically connected and the connection nodes constitute the second system DC output terminal DC1-.

[0106] Understandably, the system uses a three-phase four-wire connection method, which can provide both line voltage and phase voltage simultaneously, making it easy to connect to single-phase loads and highly adaptable.

[0107] In some embodiments, the first system DC output terminal DC1+ and the second system DC output terminal DC1- are electrically connected to a fourth capacitor C4 for filtering.

[0108] It should be noted that by cascading M isolated AC-DC rectifiers, with each device's three-phase input ports connected in series to the three-phase power grid, each device withstands a portion of the input voltage, thus increasing the overall withstand voltage rating to M times that of a single device. Simultaneously, the DC output ports of all devices are connected in parallel, achieving power aggregation and providing a stable DC power supply for high-power DC loads. This system cascades the AC inputs of M isolated AC-DC rectifiers (i.e., Ai- and A(i+1)+ are connected in series), and the DC outputs of all isolated AC-DC rectifiers are connected in parallel. This allows each device to withstand only about 1 / M of the input voltage, thus flexibly matching different voltage levels and power requirements by simply increasing or decreasing the number of devices by M, achieving modular expansion and adapting to a wide input voltage range. Furthermore, the parallel connection of the DC outputs of the M devices aggregates multiple energy sources, significantly reducing the output voltage ripple at the system's DC output due to the mutual cancellation of each phase. Moreover, in the event of a single device failure, the system can be isolated while the remaining devices continue to operate normally, thereby greatly improving system reliability.

[0109] It should be noted that, in some embodiments, the third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth, thirteenth, and fourteenth switch modules can be fully controllable devices such as insulated gate bipolar transistors or integrated gate commutated thyristors, as long as they can achieve high-frequency switching functions.

[0110] In some embodiments, the switching component includes a first operating mode and a second operating mode;

[0111] When the switching components are operating in the first operating mode, in the M isolated AC-DC rectifiers, all switching components of at least one phase are turned on to store energy in the corresponding inductor on the path, or all switching components of the M isolated AC-DC rectifiers are turned off to control the corresponding AC input port to be connected to the first rectifier module.

[0112] When the switching components are operating in the second operating mode, all switching components in the faulty isolated AC-DC rectifier are turned on to control the corresponding AC input port to block the first rectifier module.

[0113] In a high-voltage rectification system, in the first operating mode, all switching components connected to phase A simultaneously conduct to charge the phase A inductor L1, and then simultaneously disconnect to supply power to the corresponding first rectifier module, thereby meeting the voltage conversion requirements of subsequent circuits. The operating principle of other phases is similar and will not be elaborated here. When one of the isolated AC-DC rectifiers malfunctions, the switching components operate in the second operating mode. All switching components in the malfunctioning AC-DC rectifier remain in the conducting state, thereby isolating the faulty isolated AC-DC rectifier. This isolated AC-DC rectifier allows for flexible system expansion. In some embodiments, all switching modules in the inverter module can be closed, thereby preventing isolation failure when switching components malfunction, and improving isolation reliability.

[0114] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or at least two embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0115] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0116] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0117] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across at least two network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0118] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0119] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0120] The above are merely embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An isolated AC-DC rectifier, characterized in that, It includes a DC output port, a high-frequency isolation transformer module, a second rectifier module, L groups of AC input ports, and L first conversion units; In the j-th first conversion unit, the first conversion unit includes a switching component, a first rectifier module, and an inverter module. The AC input port includes a first AC input port and a second AC input port. The switching component is electrically connected between the first AC input port and the second AC input port in the j-th group of AC input ports. The j-th group of AC input ports, the first rectifier module, and the inverter module are sequentially electrically connected. The switching component is used to control the j-th group of AC input ports to be connected to or blocked from the first rectifier module. The first rectifier module outputs a pulsating DC voltage. The output terminal of the inverter module is electrically connected to the j-th group of input terminals of the high-frequency isolation transformer module. The output terminal of the high-frequency isolation transformer module is electrically connected to the input terminal of the second rectifier module. The output terminal of the second rectifier module is electrically connected to the DC output port. Where j is any integer from 1 to L.

2. The isolated AC-DC rectifier according to claim 1, characterized in that, In the j-th first conversion unit, the switching assembly includes a first switching module and a second switching module. The second end of the first switching module is electrically connected to the first end of the second switching module. The first end of the first switching module is electrically connected to the first AC input port. The second end of the second switching module is electrically connected to the second AC input port. The switching assembly can be bidirectionally turned on or off to control the j-th group of AC input ports to be connected or blocked from the first rectifier module.

3. The isolated AC-DC rectifier according to claim 2, characterized in that, The high-frequency isolation transformer module includes a secondary winding and L primary windings. The first end of the j-th primary winding is electrically connected to the first output end of the inverter module in the j-th first conversion unit, and the second end of the j-th primary winding is electrically connected to the second output end of the inverter module in the j-th first conversion unit. The first end of the secondary winding is electrically connected to the first input terminal of the second rectifier module, and the second end of the secondary winding is electrically connected to the second input terminal of the second rectifier module. The L primary windings are magnetically coupled to the secondary windings, thereby coupling the L-phase high-frequency AC voltage output from the L first conversion units to output the converted high-frequency AC voltage.

4. The isolated AC-DC rectifier according to claim 3, characterized in that, The first rectifier module includes a first single-phase bridge uncontrolled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module includes a second single-phase bridge uncontrolled rectifier circuit. In the j-th first conversion unit, the first input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports; the second input terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports; the first output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit; the second output terminal of the first single-phase bridge uncontrolled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit; the first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding; and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding. The first input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first terminal of the secondary winding, and the second input terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second terminal of the secondary winding. The DC output port includes a first DC output port and a second DC output port. The first output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the first DC output port, and the second output terminal of the second single-phase bridge uncontrolled rectifier circuit is electrically connected to the second DC output port.

5. The isolated AC-DC rectifier according to claim 3, characterized in that, The first rectifier module includes a first single-phase bridge fully controlled rectifier circuit, the inverter module includes a single-phase full-bridge inverter circuit, and the second rectifier module includes a second single-phase bridge fully controlled rectifier circuit. In the j-th first conversion unit, the first input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first AC input port in the j-th group of AC input ports; the second input terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second AC input port in the j-th group of AC input ports; the first output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the first input terminal of the single-phase full-bridge inverter circuit; the second output terminal of the first single-phase bridge fully controlled rectifier circuit is electrically connected to the second input terminal of the single-phase full-bridge inverter circuit; the first output terminal of the single-phase full-bridge inverter circuit is electrically connected to the first terminal of the j-th primary winding; and the second output terminal of the single-phase full-bridge inverter circuit is electrically connected to the second terminal of the j-th primary winding. The first input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first terminal of the secondary winding, and the second input terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second terminal of the secondary winding. The DC output port includes a first DC output port and a second DC output port. The first output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the first DC output port, and the second output terminal of the second single-phase bridge fully controlled rectifier circuit is electrically connected to the second DC output port.

6. The isolated AC-DC rectifier according to claim 1, characterized in that, It includes a first capacitor, the first end of which is electrically connected to the first output terminal of the second rectifier module, and the second end of which is electrically connected to the second output terminal of the second rectifier module.

7. An isolated AC-DC rectifier according to claim 3, characterized in that, It includes a second capacitor and a third capacitor. The second capacitor and the third capacitor are connected in series and then connected in parallel between the first output terminal and the second output terminal of the second rectifier module. The secondary winding is provided with a center tap, and the connection point of the second capacitor and the third capacitor is electrically connected to the center tap.

8. A high-voltage rectification system, characterized in that, include: The three-phase input terminal includes an A-phase input terminal, a B-phase input terminal, and a C-phase input terminal, and the number of each of the A-phase input terminal, the B-phase input terminal, and the C-phase input terminal is set to two. M isolated AC-DC rectifiers as described in any one of claims 2 to 7, each of the isolated AC-DC rectifiers comprising three first conversion units, wherein in the three first conversion units of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit are respectively configured as Ai+ input port and Ai- input port, the first AC input port and the second AC input port of the second first conversion unit are respectively configured as Bi+ input port and Bi- input port, and the first AC input port and the second AC input port of the third first conversion unit are respectively configured as Ci+ input port and Ci- input port, the Ai- input port is electrically connected to the A(i+1)+ input port, the AM- input port is electrically connected to one of the two A-phase input terminals, the Bi- input port is electrically connected to the B(i+1)+ input port, the BM- input port is electrically connected to one of the two B-phase input terminals, the Ci- input port is electrically connected to the C(i+1)+ input port, and the CM- input port is electrically connected to one of the two C-phase input terminals; Three inductors, including an A-phase inductor, a B-phase inductor, and a C-phase inductor, wherein the other A-phase input terminal of the two A-phase input terminals is electrically connected to A1+ through the A-phase inductor, the other B-phase input terminal of the two B-phase input terminals is electrically connected to B1+ through the B-phase inductor, and the other C-phase input terminal of the two C-phase input terminals is electrically connected to C1+ through the C-phase inductor; Where i is any integer from 1 to M, the DC output port of the isolated AC-DC rectifier includes a first DC output port and a second DC output port, M first DC output ports are electrically connected and the connection node constitutes the first system DC output terminal, and M second DC output ports of the isolated AC-DC rectifier are electrically connected and the connection node constitutes the second system DC output terminal.

9. A high-voltage rectifier system, characterized in that, include: Three-phase input terminals and N input terminal, wherein the three-phase input terminals include A-phase input terminal, B-phase input terminal and C-phase input terminal; M isolated AC-DC rectifiers as described in any one of claims 2 to 7, each of the isolated AC-DC rectifiers comprising three first conversion units, wherein in the three first conversion units of the i-th isolated AC-DC rectifier, the first AC input port and the second AC input port of the first first conversion unit are respectively configured as Ai+ input port and Ai- input port, the first AC input port and the second AC input port of the second first conversion unit are respectively configured as Bi+ input port and Bi- input port, and the first AC input port and the second AC input port of the third first conversion unit are respectively configured as Ci+ input port and Ci- input port, the Ai- input port is electrically connected to the A(i+1)+ input port, the AM- input port is electrically connected to the N input terminal, the Bi- input port is electrically connected to the B(i+1)+ input port, the BM- input port is electrically connected to the N input terminal, the Ci- input port is electrically connected to the C(i+1)+ input port, and the CM- input port is electrically connected to the N input terminal; Three inductors, including phase A inductor, phase B inductor and phase C inductor, the phase A input terminal is electrically connected to A1+ through phase A inductor, the phase B input terminal is electrically connected to B1+ through phase B inductor, and the phase C input terminal is electrically connected to C1+ through phase C inductor; Where i is any integer from 1 to M, the DC output port of the isolated AC-DC rectifier includes a first DC output port and a second DC output port, M first DC output ports are electrically connected and the connection node constitutes the first system DC output terminal, and M second DC output ports of the isolated AC-DC rectifier are electrically connected and the connection node constitutes the second system DC output terminal.

10. A high-voltage rectification system according to claim 8 or 9, characterized in that, The switching assembly includes a first operating mode and a second operating mode; When the switching components are operating in the first operating mode, in the M isolated AC-DC rectifiers, all switching components of at least one phase are turned on to store energy in the corresponding inductor on the path, or all switching components of the M isolated AC-DC rectifiers are turned off to control the corresponding AC input port to be connected to the first rectifier module. When the switching components are operating in the second operating mode, all switching components in the faulty isolated AC-DC rectifier are turned on to control the corresponding AC input port to block the first rectifier module.

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