A power module and modular power supply

Abstract

The application discloses a power module and a modular power supply, comprising a multi-winding high-frequency transformer, a power frequency rectifier, a high-frequency converter, a diode rectifier bridge, an LC branch, a direct-current interface circuit and an equalization interface circuit; according to the port composition type, the application is divided into the following three parts: the first part is connected with the primary side high-frequency converter through the LC branch, the primary side high-frequency converter is connected with the power frequency rectifier, and the power frequency rectifier output constitutes an alternating current port; the second part is connected with the secondary side rectifier bridge through the LC branch, the secondary side rectifier bridge is connected with the direct-current interface circuit, and the direct-current interface circuit output constitutes a total direct-current port; the third part is connected with the equalization interface circuit through the LC branch, and an equalization port is constituted. The application greatly reduces the volume and weight of the magnetic element, improves the power density of the equipment, introduces the resonance technology to reduce the switching loss and improve the system efficiency, and is matched with independent AC accessories to construct a three-phase four-wire alternating current port, and provides multiple types and multiple functions of electrical interfaces.

Description

Technical Field

[0001] This invention relates to the field of power electronic power conversion technology, specifically to a power module and a modular power supply. Background Technology

[0002] In recent years, the data center industry has been expanding rapidly, with the number and scale of data centers increasing. Land area and energy costs are gradually accounting for a larger proportion of data center operating costs. Reducing the floor space and energy consumption of data center server rooms has become a pressing issue in this field. Currently, commonly used power supply solutions for data centers include uninterruptible power supplies (UPS), high-voltage DC systems, and Panamax power supplies. Traditional UPS and HVDC solutions involve multiple power conversion stages, resulting in low efficiency, large footprint, and poor flexibility and scalability. Panamax power supplies, compared to previous generations, eliminate many power conversion stages, offering advantages in energy consumption reduction. However, they use power frequency transformers, which, due to their low operating frequency and large core size and weight, severely limit the power density of the entire device. Furthermore, none of the above power supply solutions can provide a three-phase four-wire AC interface to meet the power needs of lighting, air conditioning, maintenance, and other systems, requiring additional auxiliary equipment distribution cabinets, increasing power supply costs.

[0003] The electric vehicle (EV) industry has experienced rapid growth in recent years due to its environmental advantages, driving continuous upgrades within the industry. New EVs boast longer driving ranges and larger battery capacities, requiring faster charging speeds. However, the charging infrastructure supporting the EV industry generally suffers from drawbacks such as complex structure, simple functionality, high cost, and low efficiency. Currently, EV charging stations are mainly divided into AC connection systems and DC connection systems. AC connection systems step down the medium-voltage distribution network using a power frequency transformer, then connect multiple AD / DC and DC / DC cascaded converters to the AC bus on the transformer's secondary side. This structure results in multiple conversion stages from the distribution network to the DC port, increasing system complexity and cost, and reducing system efficiency. DC connection systems connect AD / DC converters to the secondary side of the power frequency transformer to construct the DC bus. Compared to AC connection systems, this eliminates the AD / DC conversion stages of the cascaded converters, improving system efficiency to some extent. However, the power frequency transformer and numerous isolation transformers lead to low system power density, complex system structure, and low reliability. Furthermore, they cannot provide AC ports to meet the charging needs of EVs equipped with onboard chargers.

[0004] In summary, in fields such as data centers and electric vehicles, power supplies based on power electronic transformers generally suffer from common problems such as low efficiency, low power density, and limited port types. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, this invention provides a power module and a modular power supply. It replaces the traditional power frequency transformer or multiple two-winding transformers with a multi-winding high-frequency transformer, which greatly reduces the size and weight of magnetic components and improves the power density of the equipment. At the same time, it introduces resonance technology to reduce switching losses and improve system efficiency. Furthermore, it is equipped with independent AC accessories to construct a three-phase four-wire AC port, providing multiple types and functions of electrical interfaces.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A power module includes a multi-winding high-frequency transformer, a power frequency rectifier, a high-frequency converter, a secondary-side rectifier bridge, an LC branch, a DC interface circuit, and an equalization interface circuit.

[0008] The total number of windings n of the multi-winding high-frequency transformer is divided into the following three parts according to the port configuration type:

[0009] The first part is connected to the primary side high-frequency converter through the LC branch, the primary side high-frequency converter is connected to the power frequency rectifier, and the output of the power frequency rectifier forms an AC port.

[0010] The second part is connected to the secondary rectifier bridge through the LC branch. The secondary rectifier bridge is connected to the DC interface circuit, and the output of the DC interface circuit constitutes the DC port.

[0011] The third part connects to the equalization interface circuit via an LC branch, forming the equalization port.

[0012] The total number of windings of the multi-winding high-frequency transformer is n = n1 + n2 + n3; the frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz.

[0013] In the first part of the multi-winding high-frequency transformer, n1≥≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive terminal of the output side of the primary high-frequency converter, the negative terminal of the output side of the primary high-frequency converter is connected to the other terminal of the winding, the positive and negative terminals of the input side of the primary high-frequency converter are respectively connected to the positive and negative terminals of the input side of the power frequency rectifier, and the positive and negative terminals of the output side of the power frequency rectifier constitute an AC port;

[0014] In the second part of the multi-winding high-frequency transformer, among the n2≥≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive output terminal of the secondary rectifier bridge, the negative output terminal of the secondary rectifier bridge is connected to the other terminal of the winding, the positive and negative input terminals of the secondary rectifier bridge are connected to the positive and negative input terminals of the DC interface circuit, respectively, and the positive and negative output terminals of the DC interface circuit constitute a DC port. The n2 DC ports can be connected in parallel to form a total DC port.

[0015] In the third part of the multi-winding high-frequency transformer, n3≥≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive terminal of the output side of the equalization interface circuit, the negative terminal of the output side of the equalization interface circuit is connected to the other terminal of the winding, and the positive and negative terminals of the input side of the equalization interface circuit are led out to form the equalization port.

[0016] The power frequency rectifier is a single-phase full-bridge circuit; the primary-side high-frequency converter is a single-phase full-bridge circuit or can be replaced by a single-phase half-bridge, with two-level, three-level, or multi-level voltage levels; the DC interface circuit is a Buck circuit or can be replaced by a direct-connect wire or other DC / DC converter; the equalization interface circuit is a single-phase full-bridge circuit or can be replaced by a direct-connect wire, a three-phase inverter, or a single-phase half-bridge, with two-level, three-level, or multi-level voltage levels.

[0017] The secondary rectifier bridge is a diode uncontrolled rectifier bridge or a fully controlled rectifier bridge;

[0018] When applied to data center power supply, power flows unidirectionally from the AC port to the DC port. The diodes have unidirectional conduction characteristics, and the secondary rectifier bridge is an uncontrolled rectifier bridge composed of diodes, thereby reducing costs.

[0019] When applied to electric vehicle charging, power flows bidirectionally between the AC and DC ports, requiring the secondary rectifier bridge to have bidirectional current carrying capacity. It is designed as a fully controlled rectifier bridge composed of fully controlled power switching transistors.

[0020] The LC branch is an LC series resonant branch, and the inductance in the LC branch is the leakage inductance of the transformer winding or the sum of the leakage inductance and the external series inductance.

[0021] The single-phase full-bridge circuit includes four power switching transistors S1, S2, S3 and S4. Power switching transistors S1 and S2, S3 and S4 are connected in series to form two half-bridges. The DC positive and negative terminals of the two half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two half-bridges are led out to form the positive and negative terminals on the output side.

[0022] The diode uncontrolled rectifier bridge includes four power diodes D1, D2, D3 and D4. Power diodes D1 and D2, D3 and D4 are connected in series to form two diode half-bridges. The DC positive and negative terminals of the two diode half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two diode half-bridges are led out to form the positive and negative terminals on the output side.

[0023] The Buck circuit includes two power switches Q1 and Q2 and an LC filter. The power switches Q1 and Q2 are connected in series to form a half-bridge. The DC positive and negative terminals of the half-bridge constitute the positive and negative terminals on the input side. The midpoint of the half-bridge is led out and connected to the LC filter to form the positive and negative terminals on the output side.

[0024] The power switching transistors of the power frequency rectifier, primary side high-frequency converter, secondary side rectifier bridge, DC interface circuit, and equalization interface circuit are one of diodes, silicon-based MOSFETs, silicon-based IGBTs, silicon carbide-based MOSFETs, silicon carbide-based IGBTs, or gallium nitride-based FETs.

[0025] The DC ports of the DC interface circuit are connected in parallel to form a multi-interleaved parallel Buck circuit. Carrier phase shift control is adopted. By controlling the phase difference of each Buck circuit, the ripple of its output current is canceled out, the equivalent switching frequency is increased, the current ripple is reduced, and the inductor volume is reduced. According to the technical requirements of the power module application field, the DC interface circuit operates in voltage regulation mode or current regulation mode.

[0026] When used for powering data centers, the output voltage does not require active control; the DC interface circuit achieves precise power control by controlling the output current. When used for charging electric vehicles, the DC interface circuit achieves constant voltage charging or constant current charging by controlling the output voltage or output current.

[0027] When the equalization interface circuit is a direct-connection wire, a single-phase half-bridge or a full-bridge circuit and a three-phase inverter, the configuration of the equalization port is divided into the following three cases;

[0028] When the equalization interface circuit is a direct-connection wire, the equalization port is a single-phase AC equalization port;

[0029] When the equalization interface circuit is a single-phase half-bridge or full-bridge circuit, the equalization port is a DC equalization port;

[0030] When the balancing interface circuit is a three-phase inverter, the balancing port is a three-phase four-wire balancing port;

[0031] A modular power supply includes one or more power modules; the AC input ports and DC output ports of each power module are connected in series and in parallel respectively; the modular power supply can be boosted or expanded; the modular power supply has a three-phase AC port, a DC port and an equalization port; the modular power supply is connected to an AC accessory circuit to provide a three-phase four-wire port.

[0032] The AC accessory circuit includes a DC input AC accessory circuit and an AC input AC accessory circuit;

[0033] The DC input type AC accessory circuit consists of four single-phase half-bridge circuits and a three-phase LC filter circuit. The positive and negative terminals of the input side of the four single-phase half-bridges are connected in parallel and led out to form the positive and negative terminals of the DC input side. The midpoints of three bridge arms are connected to the LC filter circuit and led out to form the three-phase AC output terminals. The midpoint of the fourth bridge arm is connected to the common terminal of the capacitor in the three-phase LC filter circuit and led out as the neutral line output terminal.

[0034] The AC input type AC accessory circuit is composed of six single-phase half-bridge circuits connected in parallel. The positive and negative terminals of the input side of the six single-phase half-bridges are connected in parallel. The midpoints of the first and second bridge arms are led out to form the positive and negative terminals of the single-phase AC input, respectively. The midpoints of the third, fourth, and fifth bridge arms are connected to the three-phase LC filter circuit and led out to form the three-phase AC output terminals. The midpoint of the sixth bridge arm is connected to the common terminal of the capacitor in the three-phase LC filter circuit and led out as the neutral line output terminal.

[0035] The connection methods for the three-phase AC ports of the modular power supply include:

[0036] The AC input ports of each power module constitute a three-phase circuit, and each module constitutes A0≥(A 0+ A 0- The positive and negative terminals of the ≥) port are connected in series between modules to form phase A circuit; each module constitutes phase B0 (B 0+ B 0- The positive and negative terminals of the port are connected in series between modules to form a phase B circuit; each module constitutes a C0(C) phase circuit. 0+ C 0- The positive and negative terminals of the port are connected in series between the modules to form the C-phase circuit; the negative terminals of the A, B, and C phase circuits are connected together to form the neutral point N.

[0037] The modular power supply DC port configuration includes:

[0038] The DC ports (h0, l0) of each power module are connected in parallel to form the total DC port (h, l) of the modular power supply.

[0039] The power module balancing port configuration includes:

[0040] When the equalization port of the power module is a single-phase AC equalization port, the single-phase AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common high-frequency AC bus. At this time, the positive and negative terminals of the input side of the AC input type AC accessory circuit can be connected to the common high-frequency AC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory.

[0041] When the equalization port of the power module is a DC equalization port, the DC equalization ports of the k modules that constitute the modular power supply are connected in parallel to form a common DC bus. At this time, the positive and negative terminals of the input side of the DC input type AC accessory circuit can be connected to the common DC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory.

[0042] When the equalization port of the power module is a three-phase four-wire AC equalization port, the three-phase four-wire AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common three-phase four-wire AC bus. At this time, there is no need to connect the AC accessory circuit, and the three-phase four-wire terminal can be directly led out.

[0043] The common high-frequency AC bus, common DC bus, and common three-phase four-wire AC bus enable the self-flowing balance of power and achieve self-balancing of DC capacitor voltage in each module.

[0044] The three-phase four-wire port has different functions depending on the application field of the modular power supply. When used for data center power supply, the three-phase four-wire port supplies power to lighting systems, air conditioning systems, maintenance systems and other systems. When used for electric vehicle charging, the three-phase four-wire port meets the charging needs of electric vehicles equipped with on-board chargers, realizing AC and DC integrated charging.

[0045] The beneficial effects of this invention are:

[0046] (1) The modular power supply of the present invention uses a multi-winding high-frequency transformer to replace the traditional power frequency transformer or multiple two-winding transformers, which makes it smaller in size and weight, greatly reduces the size and weight of magnetic components, and improves the power density of the equipment.

[0047] (2) The modular power supply of the present invention integrates multi-stage power conversion equipment into one device, avoiding line losses between multi-stage equipment. At the same time, the introduction of resonance technology ensures that the quasi-sinusoidal current of the winding is almost in phase with the square wave voltage, so that the switching devices in the high-frequency converter bear very small current stress when turning on and off, and even when operating at a high switching frequency, it still generates small turn-on and turn-off losses, thus improving system efficiency.

[0048] (3) The modular power supply of the present invention can be used for power supply of data centers and electric vehicle charging. The number of windings n2 constituting the DC port can be set according to specific circumstances. Moreover, the DC interface circuit can work in voltage regulation mode or current regulation mode, so that the DC port can meet the technical requirements of different application fields and has high practicality and flexibility.

[0049] (4) The modular power supply of this invention has diverse electrical interfaces and more functions. The common AC bus or DC bus can be connected to compatible AC accessories, providing three-phase four-wire ports with different functions in different application fields. When used for data center power supply, the three-phase four-wire ports can supply power to lighting systems, air conditioning systems, maintenance systems and other systems without the need for additional auxiliary equipment distribution cabinets, reducing power supply costs; when used for electric vehicle charging, the three-phase four-wire ports can meet the charging needs of electric vehicles equipped with on-board chargers, realizing integrated AC and DC charging.

[0050] (5) The power fluctuation between the three phases of the AC port of the modular power supply of the present invention can be partially or completely canceled by the coupled transformer magnetic circuit to greatly reduce the capacitance of the DC side capacitor used to buffer the power fluctuation in the module. In this way, the traditional electrolytic capacitor can be replaced by a thin film capacitor, which reduces the volume and weight and overcomes the defects in lifespan. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the power module of the present invention.

[0052] Figure 2 This is a structural schematic diagram of the AC component of the modular power supply of the present invention.

[0053] Figure 3 This is a schematic diagram of the three-phase AC port and DC port configuration of the modular power supply of the present invention.

[0054] Figure 4 This is a schematic diagram of the balanced bus configuration and AC accessory connection of the modular power supply of the present invention.

[0055] Figure 5 This is a schematic diagram of the modular power supply structure according to an embodiment of the present invention.

[0056] Figure 6 This is a simulation waveform diagram of an embodiment of the present invention. Detailed Implementation

[0057] The present invention will now be described in further detail with reference to the accompanying drawings.

[0058] like Figure 1As shown, a power module includes a multi-winding high-frequency transformer, a power frequency rectifier, a high-frequency converter, a diode rectifier bridge, an LC branch, a DC interface circuit, and an equalization interface circuit.

[0059] The total number of windings n of the multi-winding high-frequency transformer is divided into the following three parts according to the port configuration type:

[0060] The first part is connected to the primary side high-frequency converter through the LC branch, the primary side high-frequency converter is connected to the power frequency rectifier, and the output of the power frequency rectifier forms an AC port.

[0061] The second part is connected to the secondary rectifier bridge through the LC branch. The secondary rectifier bridge is connected to the DC interface circuit, and the output of the DC interface circuit constitutes the DC port.

[0062] The third part connects to the equalization interface circuit via an LC branch, forming the equalization port.

[0063] In the multi-winding high-frequency transformer with n1≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive output terminal of the primary high-frequency converter, the negative output terminal of the primary high-frequency converter is connected to the other terminal of the winding, the positive and negative input terminals of the primary high-frequency converter are connected to the positive and negative input terminals of the power frequency rectifier, and the positive and negative output terminals of the power frequency rectifier constitute an AC port;

[0064] In the multi-winding high-frequency transformer with n2≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive output terminal of the secondary rectifier bridge, the negative output terminal of the secondary rectifier bridge is connected to the other terminal of the winding, the positive and negative input terminals of the secondary rectifier bridge are connected to the positive and negative input terminals of the DC interface circuit, respectively, and the positive and negative output terminals of the DC interface circuit constitute a DC port. The n2 DC ports can be connected in parallel to form a total DC port.

[0065] In the multi-winding high-frequency transformer with n3≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive terminal of the output side of the equalization interface circuit, the negative terminal of the output side of the equalization interface circuit is connected to the other terminal of the winding, and the positive and negative terminals of the input side of the equalization interface circuit are led out to form the equalization port.

[0066] The total number of windings of the multi-winding high-frequency transformer is n = n1 + n2 + n3; the frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz.

[0067] The power frequency rectifier is a single-phase full-bridge circuit; the primary-side high-frequency converter is a full-bridge circuit, which can be replaced by a single-phase half-bridge, and the voltage levels can be two-level, three-level, or multi-level; the DC interface circuit is a Buck circuit, which can be replaced by a direct-connect wire or other DC / DC converter; the equalization interface circuit is a full-bridge circuit, which can be replaced by a direct-connect wire, a three-phase inverter, or a single-phase half-bridge, and the voltage levels can be two-level, three-level, or multi-level.

[0068] The secondary-side rectifier bridge is designed as a diode or a fully controlled transistor according to the technical requirements of the power module application field. For example, when applied to data center power supply, power flows unidirectionally from the AC port to the DC port. Diodes have unidirectional conduction characteristics, so the secondary-side rectifier bridge can be designed as follows: Figure 1 (b) shows an uncontrolled rectifier bridge composed of diodes, thereby reducing costs. When applied to electric vehicle charging, power flows bidirectionally between the AC and DC ports, requiring the secondary-side rectifier bridge to have bidirectional current carrying capacity; therefore, it needs to be designed as follows: Figure 1 (c) and (d) show fully controlled rectifier bridges composed of fully controlled power switching transistors.

[0069] The LC branch is an LC series resonant branch, and the inductance in the LC branch is the leakage inductance of the transformer winding or the sum of the leakage inductance and the external series inductance.

[0070] The single-phase full-bridge circuit includes four power switching transistors S1, S2, S3 and S4. Power switching transistors S1 and S2, S3 and S4 are connected in series to form two half-bridges. The DC positive and negative terminals of the two half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two half-bridges are led out to form the positive and negative terminals on the output side.

[0071] The diode uncontrolled rectifier bridge includes four power diodes D1, D2, D3 and D4. Power diodes D1 and D2, D3 and D4 are connected in series to form two diode half-bridges. The DC positive and negative terminals of the two diode half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two diode half-bridges are led out to form the positive and negative terminals on the output side.

[0072] The Buck circuit includes two power switches Q1 and Q2 and an LC filter. The power switches Q1 and Q2 are connected in series to form a half-bridge. The DC positive and negative terminals of the half-bridge constitute the positive and negative terminals on the input side. The midpoint of the half-bridge is led out and connected to the LC filter to form the positive and negative terminals on the output side.

[0073] The power switching transistors of the power frequency rectifier, primary side high-frequency converter, secondary side rectifier bridge, DC interface circuit, and equalization interface circuit are one of diodes, silicon-based MOSFETs, silicon-based IGBTs, silicon carbide-based MOSFETs, silicon carbide-based IGBTs, or gallium nitride-based FETs.

[0074] The number of windings n2 that constitute the DC port of the power module is determined by the technical requirements of the application field of the power module, the rated power of the module, and the voltage and current withstand capability of the switching devices. It can be flexibly set according to specific circumstances. The following example illustrates the selection basis.

[0075] (1) When the power module is used for power supply in data centers, the input is required to be three-phase AC, so the number of windings forming the AC port is n1 = 3; the rated power of the module is 80kW, and the output DC voltage is required to be 200V~280V. The DC side voltage of the diode rectifier bridge is 300V. The switching transistor of model IPW65R018CFD7 (650V / 106A) produced by Infineon is selected. Due to the current withstand limit of the switching transistor, n2 = 6 windings are required to form the DC port and connect them in parallel for current shunting; the power module also needs n3 ≥ = 1 equalization port to be connected to the equalization port of other modules to achieve self-balancing of power and capacitor voltage of multiple power modules. At this time, the total number of windings is n = 10.

[0076] (2) When the power module is used for electric vehicle charging, the input is required to be three-phase AC, so the number of windings forming the AC port is n1 = 3. In order to ensure compatibility with various electric vehicle batteries, the output DC voltage is required to be 200V~850V, the module power is 80kW, the DC side voltage of the diode rectifier bridge is 850V, and the switching transistor of model IDWD100E120D7 (1200V / 100A) produced by Infineon is selected. Due to the current withstand limit of the switching transistor, n2 = 3 windings are required to form the DC port and connect them in parallel to shunt the current. The power module also needs n3 ≥ = 1 equalization port to be connected to the equalization port of other modules to achieve self-balancing of power and capacitor voltage of multiple power modules. At this time, the total number of windings is n = 7.

[0077] The DC ports of the DC interface circuit are connected in parallel to form a multi-layered interleaved parallel Buck circuit. Using carrier phase-shift control, the output current ripples of each Buck circuit are canceled out by controlling the phase difference, thus increasing the equivalent switching frequency and reducing current ripple, thereby reducing the inductor size. Depending on the technical requirements of the power module application, the DC interface circuit can operate in voltage regulation or current regulation mode. For example, when used in data center power supply, the output voltage does not require active control; the DC interface circuit achieves precise power control by controlling the output current. When used in electric vehicle charging, the DC interface circuit achieves constant voltage charging or constant current charging by controlling the output voltage or output current.

[0078] When the equalization interface circuit is a direct-connection wire, a single-phase half-bridge or a full-bridge circuit and a three-phase inverter, the configuration of the equalization port is divided into the following three cases;

[0079] When the equalization interface circuit is a direct-connection wire, the equalization port is a single-phase AC equalization port;

[0080] When the equalization interface circuit is a single-phase half-bridge or full-bridge circuit, the equalization port is a DC equalization port;

[0081] When the balancing interface circuit is a three-phase inverter, the balancing port is a three-phase four-wire balancing port.

[0082] A modular power supply includes one or more power modules; the AC input ports and DC output ports of each power module are connected in series and in parallel to realize the voltage boosting or capacity expansion of the modular power supply; the modular power supply has a three-phase AC port, a DC port and an equalization port; the modular power supply can be connected to an AC accessory circuit to provide a three-phase four-wire port.

[0083] like Figure 2 The AC accessory circuit shown includes DC input type AC accessory circuit and AC input type AC accessory circuit; such as Figure 2 As shown in (a), the DC input type AC accessory circuit includes eight power switches S1, S2, S3, S4, S5, S6, S7, and S8, and a three-phase LC filter circuit. Power switches S1 and S2, S3 and S4, S5 and S6, and S7 and S8 are connected in series to form four single-phase half-bridge circuits. The positive and negative DC terminals of the four single-phase half-bridges are connected in parallel and led out to form the positive and negative terminals (H) of the DC input side. dc+ H dc- The midpoints of the three half-bridges are connected to LC filter circuits and then led out to form three-phase AC output terminals (H). a H b H c The midpoint of the fourth half-bridge is connected to the common terminal of the capacitors in the three-phase LC filter circuit, and is led out as the neutral output terminal (H). n DC input side positive and negative terminals (H) dc+ H dc- It can be connected to the DC port or DC bus of the power module to invert DC to three-phase AC, and after filtering, lead out a three-phase four-wire port.

[0084] like Figure 2 As shown in (b), the AC input type AC accessory circuit includes 12 power switching transistors S1, S2, S3, S4, S5, S6, S7, S8, S9, S12, S23, S4, S5, S6, S7, S8, S9, S12, S13, S14, S15, S16, S17, S18, S19, S10, S10, S11, S12, S13, S 10 S 11 S 12 And a three-phase LC filter circuit, power switches S1 and S2, S3 and S4, S5 and S6, S7 and S8, S9 and S 10 S 11and S 12 Six single-phase half-bridge circuits are connected in series to form six single-phase half-bridge circuits. The positive and negative DC terminals of the six single-phase half-bridges are connected in parallel. The midpoints of the first and second half-bridges are led out to form the positive and negative terminals of the single-phase AC input (G). ac+ G ac- The midpoints of the 3rd, 4th, and 5th half-bridges are connected to a three-phase LC filter circuit, and then led out to form a three-phase AC output terminal (G). a G b G c The midpoint of bridge arm 6 is connected to the common terminal of the capacitor in the three-phase LC filter circuit, and is led out as the neutral output terminal (G). n Single-phase AC input positive and negative terminals (G) ac+ G ac- ≥) can be connected to the AC port or AC bus of the power module to rectify AC into DC and then invert it into three-phase AC. After filtering, a three-phase four-wire port is led out.

[0085] like Figure 3 As shown, the connection methods of the three-phase AC ports of the modular power supply include:

[0086] The AC input ports of each power module constitute a three-phase circuit, and each module constitutes A0≥(A 0+ A 0- The positive and negative terminals of the ≥) port are connected in series between modules to form phase A circuit; each module constitutes phase B0 (B 0+ B 0- The positive and negative terminals of the port are connected in series between modules to form a phase B circuit; each module constitutes a C0(c) phase circuit. 0+ C 0- The positive and negative terminals of the port are connected in series between modules to form a C-phase circuit; the negative terminals of the A, B, and C phase circuits are connected together to form the neutral point N; through series connection for voltage division, the three-phase AC ports of the modular power supply can be connected to a medium-voltage or higher-voltage three-phase power grid, improving its practical application flexibility.

[0087] The modular power supply DC port configuration includes:

[0088] The DC ports (h0, l0) of each power module are connected in parallel to form the total DC port (h, l) of the modular power supply. By connecting in parallel, the power supply can be split, making it easier to expand the capacity of the modular power supply and output higher power at the DC port to meet different power requirements in practical applications.

[0089] The power module balancing port configuration includes:

[0090] like Figure 4As shown in (a), when the equalization port of the power module is a single-phase AC equalization port, the single-phase AC equalization ports of the k modules constituting the modular power supply are connected in parallel to form a common high-frequency AC bus. At this time, the positive and negative terminals of the input side of the AC input type AC accessory circuit can be connected to the common high-frequency AC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory.

[0091] like Figure 4 As shown in (b), when the equalization port of the power module is a DC equalization port, the DC equalization ports of the k modules constituting the modular power supply are connected in parallel to form a common DC bus. At this time, the positive and negative terminals of the input side of the DC input type AC accessory circuit can be connected to the common DC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory.

[0092] like Figure 4 As shown in (c), when the equalization port of the power module is a three-phase four-wire AC equalization port, the three-phase four-wire AC equalization ports of the k modules constituting the modular power supply are connected in parallel to form a common three-phase four-wire AC bus. At this time, there is no need to connect the AC accessory circuit, and the three-phase four-wire terminal can be directly led out.

[0093] The common high-frequency AC bus, common DC bus, and common three-phase four-wire AC bus enable the self-flowing balance of power and achieve self-balancing of DC capacitor voltage in each module.

[0094] The three-phase four-wire port has different functions depending on the application field of the modular power supply. For example, when used for data center power supply, the three-phase four-wire port can supply power to lighting systems, air conditioning systems, maintenance systems, and other systems; when used for electric vehicle charging, the three-phase four-wire port can meet the charging needs of electric vehicles equipped with on-board chargers, realizing integrated AC / DC charging. In summary, the power module of this invention uses a multi-winding high-frequency transformer to replace the traditional power frequency transformer or multiple two-winding transformers, significantly reducing the size and weight of magnetic components; at the same time, it introduces resonant technology, so that the power switching devices still produce small turn-on and turn-off losses even when operating at high switching frequencies; and it has diverse electrical interfaces and more functions. Figure 1As shown, n1 windings in the multi-winding high-frequency transformer are used to construct the AC port. When connected to a three-phase AC power grid, the fluctuating power between the three phases can be partially or completely canceled by the coupled transformer magnetic circuit, significantly reducing the capacitance value of the DC-side capacitor used to buffer fluctuating power within the module. n2 windings are used to construct the DC port. The number of windings and different control modes can be flexibly set according to specific application areas, making the modular power supply suitable for both data center power supply and electric vehicle charging. n3 windings are used to construct the balancing port. When one or more power modules are selected to construct a modular power supply according to voltage and power level requirements, the interconnection of the balancing ports can achieve self-balancing of power and capacitor voltage among the modules. The common DC or AC bus formed by the interconnection of the balancing ports can also be connected to DC input type or AC input type AC accessory circuits to provide a three-phase four-wire port, with different functions in different application areas. The power module and modular power supply of this invention aim to solve the common problems of low efficiency, low power density, and limited port types in data center power supply, electric vehicle charging, and other fields.

[0095] Please see Figure 5 , Figure 5 This is a modular power supply topology diagram according to an embodiment of the present invention. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0096] Specifically, such as Figure 5 As shown in (a), in a power supply module, the high-frequency transformer has ten windings, with the three primary windings forming three AC ports A0 (A 0+ A 0- ), B0(B 0+ B 0- ), C0(C 0+ C 0- The six secondary windings form six DC ports, which are then connected in parallel to form the total DC port (h0, l0) of the power module; one secondary winding forms one equalization port. The power frequency rectifier and high-frequency converter are single-phase full-bridge circuits, the DC voltage regulation circuit is a Buck circuit, and the equalization interface circuit is a single-phase full-bridge circuit. In this embodiment of the invention, which is applied to data center power supply, the secondary rectifier bridge is a diode uncontrolled rectifier bridge.

[0097] Specifically, such as Figure 5 As shown in (b), the A0(A) of each of the ten power modules 0+ A 0- The positive and negative terminals of the port are connected in series between modules to form phase A circuit; at the same time, the B0 (B) of each module 0+ B 0- ), C0(C 0+ C 0-The positive and negative terminals of the ports are connected in series between modules to form phase B and phase C circuits, respectively; the negative terminals of phases A, B, and C are connected together to form the neutral point N. The DC ports (h0, l0) of the ten power modules are connected in parallel to form the total DC port (h, l). The equalization ports (dc+, dc-) of the ten power modules are connected in parallel to form a common DC bus. The three-phase AC ports (A, B, C) are connected in series with an inductor and then connected to a three-phase medium-voltage AC source, and the DC ports (h, l) are connected to a DC load. The common DC bus of the modular power supply is connected to a DC input type AC accessory, and the output side of the DC input type AC accessory is connected to a three-phase four-wire load.

[0098] The simulation parameters of the modular power supply model designed in this embodiment are summarized in Table 1. Based on this, the modular power supply simulation model built using Matlab / Simulink achieved the expected design goals and implemented the control function. Simulation waveforms are summarized in... Figure 6 middle.

[0099] Table 1 ≥ Data Center Power Simulation Parameters

[0100]

[0101] Figure 6 This is a simulation waveform diagram of an embodiment of the present invention. For example... Figure 6 As shown, (a) is the three-phase grid voltage waveform; (b) is the three-phase grid current waveform; (c) is the low-voltage DC output voltage waveform; (d) is the low-voltage DC output current waveform; (e) is the output power waveform; (f) is the A-phase voltage modulation waveform; (g) is the DC side capacitor voltage waveform; and (h) is the three-phase four-wire port output voltage waveform.

[0102] After the simulation model started normally, the output power was 1MW (rated). The three-phase grid voltage and current were in phase to ensure high power factor operation, and the output voltage stabilized at 270VDC. At t=0.2s, the output voltage dropped to 220VDC. The Buck circuit operated in current regulation mode, and the current at the DC port changed rapidly with the control command to maintain the rated output power. The three-phase grid current and DC capacitor voltage remained basically unchanged before and after the voltage drop. The three-phase four-wire port output voltage was normal, proving that the modular power supply simulation model was working normally and had good dynamic performance.

Claims

1. A modular power supply, characterized in that, Includes one or more power modules; The power module includes a multi-winding high-frequency transformer, a power frequency rectifier, a high-frequency converter, a secondary-side rectifier bridge, an LC branch, a DC interface circuit, and an equalization interface circuit. The total number of windings of the multi-winding high-frequency transformer According to the port configuration type, it is divided into the following three parts: The first part is connected to the primary side high-frequency converter through the LC branch, the primary side high-frequency converter is connected to the power frequency rectifier, and the output of the power frequency rectifier forms an AC port. The second part is connected to the secondary rectifier bridge through the LC branch. The secondary rectifier bridge is connected to the DC interface circuit, and the output of the DC interface circuit constitutes the DC port. The third part connects to the equalization interface circuit via the LC branch, forming the equalization port; The DC ports of the DC interface circuit are connected in parallel to form a multi-interleaved parallel Buck circuit. Carrier phase shift control is used to control the phase difference of each Buck circuit so that the ripple of its output current cancels each other out. The DC interface circuit operates in voltage regulation mode or current regulation mode. When used for powering data centers, the output voltage does not require active control; the DC interface circuit achieves precise power control by controlling the output current. When used for charging electric vehicles, the DC interface circuit achieves constant voltage charging or constant current charging by controlling the output voltage or output current. When the equalization interface circuit is a direct-connection wire, a single-phase half-bridge or a full-bridge circuit and a three-phase inverter, the configuration of the equalization port is divided into the following three cases; When the equalization interface circuit is a direct-connection wire, the equalization port is a single-phase AC equalization port; When the equalization interface circuit is a single-phase half-bridge or full-bridge circuit, the equalization port is a DC equalization port; When the equalization interface circuit is a three-phase inverter, the equalization port is a three-phase four-wire equalization port; The power module balancing port configuration includes: When the equalization port of the power module is a single-phase AC equalization port, the single-phase AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common high-frequency AC bus. At this time, the positive and negative terminals of the input side of the AC input type AC accessory circuit can be connected to the common high-frequency AC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory. When the equalization port of the power module is a DC equalization port, the DC equalization ports of the k modules that constitute the modular power supply are connected in parallel to form a common DC bus. At this time, the positive and negative terminals of the input side of the DC input type AC accessory circuit can be connected to the common DC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory. When the equalization port of the power module is a three-phase four-wire AC equalization port, the three-phase four-wire AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common three-phase four-wire AC bus. At this time, there is no need to connect the AC accessory circuit, and the three-phase four-wire terminal can be directly led out. The common high-frequency AC bus, common DC bus, and common three-phase four-wire AC bus enable the self-flow balance of power and achieve self-balancing of DC capacitor voltage in each module. The secondary rectifier bridge is a diode uncontrolled rectifier bridge or a fully controlled rectifier bridge; When applied to power data centers, power flows unidirectionally from the AC port to the DC port. The diodes have unidirectional conduction characteristics, and the secondary rectifier bridge is an uncontrolled rectifier bridge composed of diodes. When applied to electric vehicle charging, power flows bidirectionally between the AC and DC ports, and the secondary rectifier bridge needs to have bidirectional current carrying capacity. It is designed as a fully controlled rectifier bridge composed of fully controlled power switching transistors. The LC branch is an LC series resonant branch, and the inductance in the LC branch is the leakage inductance of the transformer winding or the sum of the leakage inductance and the external series inductance. The AC input ports and DC output ports of each power module are connected in series and in parallel, respectively; the modular power supply can be boosted or expanded; the power module has a three-phase AC port, a DC port, and an equalization port; the power module is connected to an AC accessory circuit to provide a three-phase four-wire port; The AC accessory circuit includes DC input AC accessory circuit and AC input AC accessory circuit: The DC input type AC accessory circuit consists of four single-phase half-bridge circuits and a three-phase LC filter circuit. The positive and negative terminals of the input side of the four single-phase half-bridges are connected in parallel and led out to form the positive and negative terminals of the DC input side. The midpoints of three bridge arms are connected to the LC filter circuit and led out to form the three-phase AC output terminals. The midpoint of the fourth bridge arm is connected to the common terminal of the capacitor in the three-phase LC filter circuit and led out as the neutral line output terminal. The AC input type AC accessory circuit is composed of six single-phase half-bridge circuits connected in parallel. The positive and negative terminals of the input side of the six single-phase half-bridges are connected in parallel. The midpoints of the first and second bridge arms are led out to form the positive and negative terminals of the single-phase AC input. The midpoints of the third, fourth and fifth bridge arms are connected to the three-phase LC filter circuit and led out to form the three-phase AC output terminals. The midpoint of the sixth bridge arm is connected to the common terminal of the capacitor in the three-phase LC filter circuit and led out as the neutral line output terminal. The total number of windings of the multi-winding high-frequency transformer The frequency of the multi-winding high-frequency transformer is any frequency in the range of several hundred hertz to several hundred kilohertz.

2. The modular power supply according to claim 1, characterized in that, The first part of the multi-winding high-frequency transformer In ≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive terminal of the output side of the primary high-frequency converter, the negative terminal of the output side of the primary high-frequency converter is connected to the other terminal of the winding, the positive and negative terminals of the input side of the primary high-frequency converter are connected to the positive and negative terminals of the input side of the power frequency rectifier, and the positive and negative terminals of the output side of the power frequency rectifier constitute an AC port; The second part of the multi-winding high-frequency transformer In a winding with ≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, and the other terminal of the LC branch is connected to the positive output terminal of the secondary rectifier bridge. The negative output terminal of the secondary rectifier bridge is connected to the other terminal of the winding. The positive and negative input terminals of the secondary rectifier bridge are connected to the positive and negative input terminals of the DC interface circuit, respectively. The positive and negative output terminals of the DC interface circuit constitute the DC port. The DC ports can be connected in parallel to form a total DC port; The third part of the multi-winding high-frequency transformer In ≥0 windings, one terminal of each winding is connected to one terminal of an LC branch, the other terminal of the LC branch is connected to the positive terminal of the output side of the equalization interface circuit, the negative terminal of the output side of the equalization interface circuit is connected to the other terminal of the winding, and the positive and negative terminals of the input side of the equalization interface circuit are led out to form the equalization port.

3. A modular power supply according to claim 1, characterized in that, The power frequency rectifier is a single-phase full-bridge circuit; the primary-side high-frequency converter is a single-phase full-bridge circuit or can be replaced by a single-phase half-bridge, with two-level, three-level, or multi-level voltage levels; the DC interface circuit is a Buck circuit or can be replaced by a direct-connect wire or other DC / DC converter; the equalization interface circuit is a single-phase full-bridge circuit or can be replaced by a direct-connect wire, a three-phase inverter, or a single-phase half-bridge, with two-level, three-level, or multi-level voltage levels.

4. A modular power supply according to claim 3, characterized in that, The single-phase full-bridge circuit includes four power switching transistors. and Power switching transistor and , and The two half-bridges are connected in series to form two half-bridges. The positive and negative DC terminals of the two half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two half-bridges are led out to form the positive and negative terminals on the output side. The diode rectifier bridge includes four power diodes. and Power diodes and , and Two diode half-bridges are connected in series to form two diode half-bridges. The positive and negative DC terminals of the two diode half-bridges are connected in parallel to form the positive and negative terminals on the input side. The midpoints of the two diode half-bridges are led out to form the positive and negative terminals on the output side. The Buck circuit includes two power switching transistors. A LC filter, a power switch The two components are connected in series to form a half-bridge. The positive and negative DC terminals of the half-bridge constitute the positive and negative terminals on the input side, and the midpoint of the half-bridge is led out and connected to an LC filter to form the positive and negative terminals on the output side. The power switching transistors of the power frequency rectifier, primary side high-frequency converter, secondary side rectifier bridge, DC interface circuit, and equalization interface circuit are one of diodes, silicon-based MOSFETs, silicon-based IGBTs, silicon carbide-based MOSFETs, silicon carbide-based IGBTs, or gallium nitride-based FETs.

5. A modular power supply according to claim 4; characterized in that, The connection methods for the three-phase AC ports of the modular power supply include: The AC input ports of each power module constitute a three-phase circuit, and each module constitutes... ( The positive and negative terminals of the port are connected in series between modules to form phase A circuit; each module constitutes ( The positive and negative terminals of the port are connected in series between modules to form a phase B circuit; each module constitutes... ( The positive and negative terminals of the port are connected in series between the modules to form the C-phase circuit; the negative terminals of the A, B, and C phase circuits are connected together to form the neutral point N. The modular power supply DC port configuration includes: DC port of each power module They are connected in parallel to form the main DC port of the modular power supply. ; The power module balancing port configuration includes: When the equalization port of the power module is a single-phase AC equalization port, the single-phase AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common high-frequency AC bus. At this time, the positive and negative terminals of the input side of the AC input type AC accessory circuit can be connected to the common high-frequency AC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory. When the equalization port of the power module is a DC equalization port, the DC equalization ports of the k modules that constitute the modular power supply are connected in parallel to form a common DC bus. At this time, the positive and negative terminals of the input side of the DC input type AC accessory circuit can be connected to the common DC bus, and the three-phase four-wire port is led out from the output side terminal of the AC accessory. When the equalization port of the power module is a three-phase four-wire AC equalization port, the three-phase four-wire AC equalization ports of k modules constituting the modular power supply are connected in parallel to form a common three-phase four-wire AC bus. At this time, there is no need to connect the AC accessory circuit, and the three-phase four-wire terminal can be directly led out. The common high-frequency AC bus, common DC bus, and common three-phase four-wire AC bus enable the self-flowing balance of power and achieve self-balancing of DC capacitor voltage in each module.

6. A modular power supply according to claim 5; characterized in that, The three-phase four-wire port has different functions depending on the application field of the modular power supply. When used for data center power supply, the three-phase four-wire port supplies power to lighting systems, air conditioning systems, maintenance systems and other systems. When used for electric vehicle charging, the three-phase four-wire port meets the charging needs of electric vehicles equipped with on-board chargers, realizing AC and DC integrated charging.

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