A single-stage isolated three-phase rectifier device with ac-side dual-port collaborative compression and a control method thereof

Abstract

The application provides a single-stage isolated three-phase rectifier device with AC-side double-port cooperative voltage build-up and a control method, and belongs to the technical field of three-phase AC / DC rectification conversion. The device comprises an A-phase rectifier unit, a B-phase rectifier unit and a C-phase rectifier unit. The three-phase rectifier units are independent of each other and are coupled in parallel at the DC side. Each of the three-phase rectifier units comprises a main rectification port and an auxiliary voltage build-up port at the AC side, and an output port at the DC side. The main rectification port and the auxiliary voltage build-up port are located at the AC input side. The main rectification port and the auxiliary voltage build-up port are coupled with corresponding primary winding of a high-frequency isolation transformer through a high-frequency bridge conversion unit. The output port is coupled with a secondary winding of the high-frequency isolation transformer. The main rectification port, the auxiliary voltage build-up port and the output port jointly form a single-stage AC / DC power conversion link. The output ports of the three-phase rectifier units are connected in parallel at the DC side. The application reduces input current harmonic distortion, improves power factor and input side power quality.

Description

Technical Field

[0001] This application belongs to the field of three-phase AC / DC rectification and conversion technology, specifically relating to a single-stage isolated three-phase rectifier device and control method with AC-side dual-port cooperative voltage configuration. Background Technology

[0002] In new energy vehicle charging devices, energy storage converter interfaces, industrial high-voltage DC power supplies, and power conversion scenarios with high requirements for isolation and safety, three-phase AC / DC rectifiers are the core power conversion units, and must simultaneously meet the core requirements of high power factor, low current harmonics, electrical isolation, stable DC output, high efficiency, and high power density.

[0003] In existing three-phase rectification schemes, three-phase uncontrolled rectification suffers from severe current harmonic distortion, low power factor, and output voltage fluctuations with the power grid. Three-phase two-level / three-level PWM rectifiers face challenges such as difficulty in equalizing voltage of switching devices in high-voltage scenarios, a large number of devices, complex drive and control logic, and midpoint potential drift. Although the VIENNA rectifier simplifies the topology, it cannot achieve bidirectional energy flow and still requires a series isolated DC / DC stage to meet the isolation and wide-range output requirements.

[0004] Existing technologies generally employ a two-stage architecture consisting of a front-end rectifier, an intermediate bus, and a rear-end isolation converter. This results in a long power transmission link, reliance on large-capacity electrolytic capacitors for power buffering, leading to high system losses, low power density, and limited overall system lifespan. Furthermore, traditional rectifier topologies suffer from insufficient inductor drive voltage in the AC voltage zero-crossing range, easily causing current waveform distortion, which in turn increases total harmonic distortion and reduces the power factor. If the system also requires high-frequency isolation and a wide-range output, a series-connected rear-end isolation DC / DC converter is still necessary, resulting in complex system control, high hardware costs, and limited overall efficiency. Existing optimization solutions often rely on increasing the switching frequency, further exacerbating device losses. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems by providing a single-stage isolated three-phase rectifier and control method with dual-port cooperative voltage construction on the AC side. By introducing a dual-input port cooperative working mechanism on the AC side of each phase, an equivalent input voltage relationship with bias support is constructed, so that the main rectifier port maintains sufficient effective driving voltage near the zero crossing of the AC input voltage. This improves the rate of change of the input inductor current, enhances the current tracking capability in the zero-crossing interval, reduces input current harmonic distortion, and improves the power factor and input-side power quality.

[0006] In a first aspect, embodiments of this application provide a single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration, the device comprising: The three rectifier units are A-phase, B-phase, and C-phase. They are independent of each other and are coupled in parallel on the DC side. Each of the three rectifier units includes a main rectifier port on the AC side, an auxiliary rectifier port on the AC side, and an output port on the DC side. The main rectifier port and the auxiliary voltage conversion port are located on the AC input side and are connected in a common negative ground manner. The main rectifier port and the auxiliary voltage conversion port are coupled to the corresponding primary winding of the high-frequency isolation transformer through a high-frequency bridge converter unit. The output port is coupled to the secondary winding of the high-frequency isolation transformer, and together with the main rectifier port and the auxiliary voltage conversion port, it forms a single-stage AC-DC power conversion link. The DC side of the output ports of the three-phase rectifier units are connected in parallel to form a common DC output terminal.

[0007] Furthermore, the main rectifier port on the AC side and the auxiliary rectifier port on the AC side of each phase rectifier unit adopt a half-bridge high-frequency bridge converter structure. Each port includes two series-connected high-frequency power switches, freewheeling diodes connected in reverse parallel with each switch, voltage equalization capacitors connected in parallel with each switch, and port input filter capacitors connected in parallel at the half-bridge input terminal. Each phase rectifier unit is equipped with a high-frequency isolation transformer. The transformer includes two sets of independent primary windings and one set of secondary windings. The two sets of primary windings are connected in series with the midpoint of the half-bridge output of the main rectifier port and the auxiliary rectifier port, respectively. Primary power transmission inductors are provided in the series branches. The DC-side output port adopts a full-bridge high-frequency bridge converter structure, which includes four high-frequency power switches connected in series and then in parallel, freewheeling diodes connected in reverse parallel with each switch, and an output filter capacitor connected in parallel at the full-bridge output. The full-bridge input is connected in series with the transformer secondary winding and the secondary power transfer inductor to form a closed loop. The main rectifier port is used for main power transmission and power factor correction; the auxiliary voltage-constructing port is used to output a stable DC bias voltage, which is superimposed on the three-phase AC line voltage connected to the corresponding phase to construct a zero-crossing equivalent input voltage with DC bias for the main rectifier port; the output port is used for phase shift reference, output voltage regulation and energy collection.

[0008] Furthermore, the A-phase rectifier unit includes an A-phase AC source, an A-phase main rectifier port A-1, an A-phase auxiliary rectifier port A-2, and an A-phase output port A-3; The positive output terminal of the A-phase AC source is connected in series with the A-phase input filter inductor. L A Phase A input damping resistor R A Then, connect it to the positive input terminal of the main rectifier port A-1 of phase A; The negative grounding terminal of the phase A AC source is directly shorted to the negative input terminal of the phase A main rectifier port A-1 and the negative input terminal of the phase A auxiliary voltage-forming port A-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the A-phase auxiliary pressure port A-2 is connected to the B-phase rectifier unit; The high-frequency AC output terminal of the main rectifier port A-1 of phase A is connected in series with the first primary-side power transmission inductor of phase A, and then connected to the two ends of the first primary winding of the high-frequency isolation transformer of phase A. The high-frequency AC output terminal of the auxiliary pressure port A-2 of phase A is connected in series with the second primary power transmission inductor of phase A, and then connected to the two ends of the second primary winding of the high-frequency isolation transformer of phase A. The secondary winding of the high-frequency isolation transformer of phase A is connected in series with the secondary power transmission inductor of phase A, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port A-3 of phase A.

[0009] Furthermore, the B-phase rectifier unit includes a B-phase AC source, a B-phase main rectifier port B-1, a B-phase auxiliary rectifier port B-2, and a B-phase output port B-3; The positive output terminal of the B-phase AC source is connected in series with a B-phase input filter inductor. L B B-phase input damping resistor R B Then, connect to the positive input terminal of the B-1 main rectifier port of phase B; The negative grounding terminal of the phase B AC source is directly short-circuited with the negative input terminal of the main rectifier port B-1 and the negative input terminal of the auxiliary voltage-forming port B-2 of phase B, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the B-2 auxiliary pressure port of phase B is connected to the C-phase rectifier unit; The high-frequency AC output terminal of the B-phase main rectifier port B-1 is connected in series with the first primary-side power transmission inductor of the B-phase, and then connected to both ends of the first primary winding of the high-frequency isolation transformer of the B-phase. The high-frequency AC output terminal of the B-phase auxiliary pressure port B-2 is connected in series with the second primary-side power transmission inductor of the B-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the B-phase. The secondary winding of the high-frequency isolation transformer of phase B is connected in series with the secondary power transmission inductor of phase B, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port B-3 of phase B.

[0010] Furthermore, the C-phase rectifier unit includes a C-phase AC source, a C-phase main rectifier port C-1, a C-phase auxiliary rectifier port C-2, and a C-phase output port C-3; The positive output terminal of the C-phase AC source is connected in series with a C-phase input filter inductor.L C C-phase input damping resistor R C Then, connect it to the positive input terminal of the C-1 main rectifier port; The negative grounding terminal of the C-phase AC source is directly shorted to the negative input terminal of the C-phase main rectifier port C-1 and the negative input terminal of the C-phase auxiliary voltage-forming port C-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the C-phase auxiliary pressure port C-2 is connected to the A-phase rectifier unit; The high-frequency AC output terminal of the C-phase main rectifier port C-1 is connected in series with the first primary-side power transmission inductor of the C-phase, and then connected to the two ends of the first primary winding of the high-frequency isolation transformer of the C-phase. The high-frequency AC output terminal of the C-phase auxiliary pressure port C-2 is connected in series with the second primary-side power transmission inductor of the C-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the C-phase. The secondary winding of the high-frequency isolation transformer of phase C is connected in series with the secondary power transmission inductor of phase C, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port C-3 of phase C.

[0011] Furthermore, the line voltage connected to phase A rectifier unit is u AB ; The line voltage connected to the B-phase rectifier unit is u BC ; The line voltage connected to the C-phase rectifier unit is u CA ; The formula for the equivalent input voltage at the main rectifier port of each phase rectifier unit is:

[0012] in, for j The equivalent input voltage of the main rectifier port. for j The auxiliary bias DC voltage at the auxiliary voltage gate of the phase auxiliary structure. The three-phase input line voltages are, where, j =A, B, C; k =A, B, C; j ≠ k ; satisfy: .

[0013] Furthermore, the main rectifier port j-1, auxiliary rectifier port j-2, and output port j-3 of each phase rectifier unit constitute a three-port power transmission equivalent model, where j = A, B, and C; Energy exchange between the three ports is accomplished through a high-frequency isolation transformer and a power transfer inductor. The port voltage, which varies with the power frequency during a single switching cycle, is considered constant. The formula for the power transferred between the ports is as follows:

[0014] in, , , The first j Power transmission between the main rectifier port and the auxiliary rectifier port, between the main rectifier port and the output port, and between the auxiliary rectifier port and the output port; , , The first j Compared to the shifts between the main rectifier port and the auxiliary rectifier port, the main rectifier port and the output port, and the auxiliary rectifier port and the output port, and ; For the first j The turns ratio of a three-phase transformer; f s This refers to the switching frequency of the three-phase rectifier topology; , , The first j The equivalent inductance for power transfer between the main rectifier port and the auxiliary rectifier port, the main rectifier port and the output port, and the auxiliary rectifier port and the output port; The formula for the total transmission power of each port is:

[0015] With output port j The high-frequency bridge voltage of -3 is used as the phase-shift control reference. By controlling the phase shift... D j 13 and D j 23 Adjust the output power of the corresponding phase output port to perform single-stage isolation conversion of AC and DC energy.

[0016] Secondly, embodiments of this application also provide a control method for a single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration, the method comprising the following steps: S1. For three-phase AC input voltage u AB , u BC ,u CA Real-time sampling is performed and fed into the phase-locked loop (PLL) to extract the synchronization phase information of phases A, B, and C. θ A , θ B , θ C The sinusoidal signal of each phase is obtained through the sinusoidal signal generation stage. θ A sin θ B sin θ C , serving as a phase reference for the AC input current of each phase; S2. DC output voltage at each phase output port U o-A , U o-B , U o-C Perform real-time sampling and compare it with the preset output voltage setpoint. U ref The comparison results in an error signal that is then adjusted by an outer voltage loop PI controller to generate an amplitude setpoint signal for the inner loop of the AC input current for each phase. , and ; S3. Multiply the amplitude reference signal of the inner loop of the AC input current for each phase by the unit sine signal of each phase to generate the reference value of the AC input current for each phase. , , Compare the reference values ​​of the AC input current for each phase with the actual input current. i A , i B , i C The current error signal is obtained by subtraction, and then sent to the PIR controller for adjustment. An AC line voltage feedforward term is added to obtain the shift ratio D of each phase's main rectifier port relative to the output port. A-13 D B-13 D C-13 After being processed by the phase-shifting drive module, the phase-shifting phase generates drive signals for each power switching device inside the A-phase main rectifier port A-1, the B-phase main rectifier port B-1, and the C-phase main rectifier port C-1, so as to track the input current against the reference sinusoidal signal and correct the power factor on the AC input side. S4. Port voltages at the auxiliary voltage-suppressing ports of each phase. u A-2 , u B-2 ,u C-2 Real-time sampling is performed, compared with the preset auxiliary port voltage setpoint. U 2_ref The voltage error signal is obtained by comparison. After the error signal is adjusted by the respective PI controller, the voltage regulation control quantity of each phase auxiliary port is generated to maintain the voltage stability of the auxiliary voltage construction port and continuously provide the bias support required to construct the AC side non-zero equivalent input voltage. S5. Output current I at each phase output port OA I OB I OC Sampling is performed, and the output power P of each phase is calculated based on the corresponding DC output voltage. A P B P C The output power of each phase is compared with the total reference power P. ref The power error signal is compared with 1 / 3 of the power, and then adjusted by the power sharing PI controller to generate the power sharing compensation for each phase. d 1. d 2. d 3. Add the compensation amount to the corresponding phase's auxiliary port voltage regulation control amount to obtain the shift ratio D of each phase's auxiliary voltage regulation port relative to the output port. A-23 D B-23 D C-23 After being processed by the phase-shifting drive module, drive signals are generated for each power switching device inside the A-phase auxiliary pressure port A-2, the B-phase auxiliary pressure port B-2, and the C-phase auxiliary pressure port C-2, so as to realize the voltage regulation of the auxiliary pressure port and the power control of the three-phase parallel output. S6. The phase shift ratio of the output port of each phase rectifier unit is fixed at 0 as the phase shift control reference for the three-port power transmission of the corresponding phase. The power magnitude and direction of the main rectifier power channel are adjusted by adjusting the phase shift ratio between the main rectifier port and the output port of each phase. The power magnitude and direction of the auxiliary rectifier power channel are adjusted by adjusting the phase shift ratio between the auxiliary rectifier port and the output port.

[0017] Furthermore, in step S3: The AC line voltage feedforward term is: u jk * K ; in, j , k =A, B, C, and j ≠ k, K This is the preset AC line voltage scaling factor.

[0018] Furthermore, the method further includes the following steps: S7. Repeat steps S1-S6 during the AC input operating cycle to continuously update the shift ratio and drive signal of each power switching device, thereby achieving three-phase AC input power factor correction, auxiliary voltage port regulation, output port regulation, and three-phase parallel output power control until the converter operates stably in the set operating state.

[0019] As can be seen from the above technical solutions, the present invention has the following advantages: In the single-stage isolated three-phase rectifier device and control method of the present invention, the main rectifier port, the auxiliary voltage-forming port, and the DC output port of each phase are used to form a single-stage AC-DC power conversion link. This eliminates the need for large-capacity electrolytic capacitors for power buffering, shortens the power transmission link, reduces overall device losses, improves system conversion efficiency and power density, and extends the overall service life of the device. Furthermore, the connection structure of the main rectifier port and the auxiliary voltage-forming port on the AC side sharing a common negative ground allows the DC bias voltage provided by the auxiliary voltage-forming port to be used to construct a DC-band-enabled main rectifier port. The zero-crossing equivalent input voltage of the current bias solves the current distortion problem caused by insufficient inductor drive voltage in the zero-crossing range of AC voltage in traditional topologies, reduces the harmonic distortion rate of the input current, improves the grid-side power factor, eliminates the need to rely on ultra-high switching frequency to optimize waveforms, and reduces EMI design difficulty and hardware cost; the structure of the three-phase rectifier units being independent and parallel coupled on the DC side can achieve equal distribution of three-phase output power, avoid the problems of single-phase module overload and uneven heat distribution, improve system reliability, facilitate expansion to higher power levels, and retain high-frequency electrical isolation capability to meet safety insulation requirements. Attached Figure Description

[0020] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the single-stage isolated three-phase rectifier device with dual-port coordinated AC voltage configuration of this application. Figure 2 This is a schematic diagram of a single-stage isolated three-phase rectifier circuit with AC-side dual-port cooperative voltage configuration in a specific embodiment of this application; Figure 3 This is a schematic diagram of the dual-port collaborative pressure relationship on the AC side of this application; Figure 4 This is a schematic diagram of the phase-shift drive signal waveform of the AC A-phase three-port switch in this application; Figure 5 This is a schematic diagram of the equivalent power transmission model of the j-phase (j=A,B,C) three-port in this application. Figure 6 This is a logic diagram of the phase-shifting drive module in the control loop of this application; Figure 7 This is a schematic diagram of the power factor correction and output-side voltage regulation control strategy of this application; Figure 8 This is a schematic diagram of the phase-to-phase power sharing control strategy of this application; Figure 9 This is a flowchart illustrating the control method of the single-stage isolated three-phase rectifier device with dual-port coordinated AC voltage configuration according to this application. Detailed Implementation

[0022] In the following detailed description of the single-stage isolated three-phase rectifier and control method with AC-side dual-port cooperative voltage configuration, various embodiments of the present invention will be described more fully. The present invention may have various embodiments, and adjustments and modifications may be made therein. However, it should be understood that there is no intention to limit the various embodiments of the present invention to the specific embodiments disclosed herein, but rather the present invention should be understood to cover all modifications, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of the present invention.

[0023] It should be understood that, when used in this specification, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0024] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0025] To facilitate a clear description of the technical solutions of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" do not necessarily imply that they are different.

[0026] To make the objectives, features, and advantages of this invention more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solutions protected by this invention. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] Please see Figure 1 The diagram shows a connection schematic of a single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration. The device includes: The three rectifier units are A-phase, B-phase, and C-phase. They are independent of each other and are coupled in parallel on the DC side. Each of the three rectifier units includes a main rectifier port on the AC side, an auxiliary rectifier port on the AC side, and an output port on the DC side. The main rectifier port and the auxiliary voltage conversion port are located on the AC input side and are connected in a common negative ground manner. The main rectifier port and the auxiliary voltage conversion port are coupled to the corresponding primary winding of the high-frequency isolation transformer through a high-frequency bridge converter unit. The output port is coupled to the secondary winding of the high-frequency isolation transformer, and together with the main rectifier port and the auxiliary voltage conversion port, it forms a single-stage AC-DC power conversion link. The DC side of the output ports of the three-phase rectifier units are connected in parallel to form a common DC output terminal.

[0028] It should be noted that this embodiment, while optimizing power quality, organically integrates three-phase rectification, high-frequency isolation, and DC voltage regulation into a single-stage power conversion structure. This reduces the additional losses associated with traditional rectifier bridges, intermediate buses, and two-stage series structures, improving system efficiency and power density, and reducing the system's dependence on ultra-high switching frequencies and stringent parameter matching. Simultaneously, the three-phase output ports can achieve even power distribution across the three phases through control strategies, ensuring good power balance when each phase module is connected in parallel. This helps avoid reliability degradation caused by single-phase module overload, uneven heat distribution, and parameter deviations, facilitating system expansion to higher power levels.

[0029] As a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, another single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration is provided. This device includes: The three rectifier units are A-phase, B-phase, and C-phase. They are independent of each other and are coupled in parallel on the DC side. Each of the three rectifier units includes a main rectifier port on the AC side, an auxiliary rectifier port on the AC side, and an output port on the DC side. The main rectifier port and the auxiliary voltage conversion port are located on the AC input side and are connected in a common negative ground manner. The main rectifier port and the auxiliary voltage conversion port are coupled to the corresponding primary winding of the high-frequency isolation transformer through a high-frequency bridge converter unit. The output port is coupled to the secondary winding of the high-frequency isolation transformer, and together with the main rectifier port and the auxiliary voltage conversion port, it forms a single-stage AC-DC power conversion link. The DC side of the output ports of the three-phase rectifier units are connected in parallel to form a common DC output terminal.

[0030] In some embodiments, the main rectifier port on the AC side and the auxiliary rectifier port on the AC side of each phase rectifier unit adopt a half-bridge high-frequency bridge converter structure. Each port includes two high-frequency power switches connected in series, freewheeling diodes connected in reverse parallel with each switch, voltage equalization capacitors connected in parallel with each switch, and port input filter capacitors connected in parallel at the half-bridge input terminal. Each phase rectifier unit is equipped with a high-frequency isolation transformer. The transformer includes two sets of independent primary windings and one set of secondary windings. The two sets of primary windings are connected in series with the midpoint of the half-bridge output of the main rectifier port and the auxiliary rectifier port, respectively. Primary power transmission inductors are provided in the series branches. The DC-side output port adopts a full-bridge high-frequency bridge converter structure, which includes four high-frequency power switches connected in series and then in parallel, freewheeling diodes connected in reverse parallel with each switch, and an output filter capacitor connected in parallel at the full-bridge output. The full-bridge input is connected in series with the transformer secondary winding and the secondary power transfer inductor to form a closed loop. The main rectifier port is used for main power transmission and power factor correction; the auxiliary voltage-constructing port is used to output a stable DC bias voltage, which is superimposed on the three-phase AC line voltage connected to the corresponding phase to construct a zero-crossing equivalent input voltage with DC bias for the main rectifier port; the output port is used for phase shift reference, output voltage regulation and energy collection.

[0031] It should be noted that in the following text, port 1 represents the main rectifier port, port 2 represents the auxiliary rectifier port, and port 3 represents the output port.

[0032] Please see Figure 2 The diagram shown is a schematic of a single-stage three-phase rectifier circuit based on AC-side dual-port cooperative voltage conversion in a specific embodiment, including a three-phase AC input side and a DC output side.

[0033] The three-phase AC input side consists of an A-phase AC input unit (ports A-1 and A-2), a B-phase AC input unit (ports B-1 and B-2), and a C-phase AC input unit (ports C-1 and C-2); the DC output side consists of an A-phase output unit (port A-3), a B-phase output unit (port B-3), and a C-phase output unit (port C-3). The DC sides of the three output units are connected in parallel to form a common DC output terminal.

[0034] The phase A AC input unit includes a phase A AC source and an input current. Input resistance Input filter inductor AC side main input port A-1, AC side auxiliary input port A-2, input filter capacitors for ports A-1 and A-2 Two switches in port A-1 , Corresponding voltage equalization capacitor , Port A-2 two switches , Corresponding voltage equalization capacitor , Primary-side power transmission inductor , And the corresponding primary winding of the high-frequency isolation transformer. The voltage across port A-1 is The voltage across port A-2 is The line voltage connected to phase A rectifier unit is u AB The high-frequency voltages corresponding to ports A-1 and A-2 are respectively and ; The B-phase AC input unit includes a B-phase AC source and an input current. Input resistance Input filter inductor AC side main input port B-1, AC side auxiliary input port B-2, input filter capacitors for ports B-1 and B-2 Two switches in port B-1 , Corresponding voltage equalization capacitor , Port B-2 two switches , Corresponding voltage equalization capacitor , Primary-side power transmission inductor , And the corresponding primary winding of the high-frequency isolation transformer. The voltage across port B-1 is The voltage across port B-2 is The line voltage connected to the B-phase rectifier unit is u BC The high-frequency voltages corresponding to ports B-1 and B-2 are respectively and ; The C-phase AC input unit includes a C-phase AC source and an input current. Input resistance Input filter inductor AC side main input port C-1, AC side auxiliary input port C-2, input filter capacitors for ports C-1 and C-2 Two switches in port C-1 , Corresponding voltage equalization capacitor , Port C-2 two switches , Corresponding voltage equalization capacitor , Primary-side power transmission inductor , And the corresponding primary winding of the high-frequency isolation transformer. The voltage across port C-1 is The voltage across port C-2 is The line voltage connected to the C-phase rectifier unit is u CA The high-frequency voltages corresponding to ports C-1 and C-2 are respectively and ; On the DC output side, the A-phase output unit includes output port A-3 and a full-bridge power switch. , , , Secondary power transmission inductor Output filter capacitor load resistance and the output voltage of port A-3 The B-phase output unit includes output port B-3 and a full-bridge power switch. , , , Secondary power transmission inductor Output filter capacitor Load resistance and port B-3 output voltage The C-phase output unit includes output port C-3 and a full-bridge power switch. , , , Secondary power transmission inductor Output filter capacitor load resistance and output voltage The DC sides of the three output ports A-3, B-3, and C-3 are connected in parallel to form a common DC output terminal.

[0035] In some embodiments, the A-phase rectifier unit includes an A-phase AC source, an A-phase main rectifier port A-1, an A-phase auxiliary rectifier port A-2, and an A-phase output port A-3; The positive output terminal of the A-phase AC source is connected in series with the A-phase input filter inductor. L A Phase A input damping resistor R A Then, connect it to the positive input terminal of the main rectifier port A-1 of phase A; The negative grounding terminal of the phase A AC source is directly shorted to the negative input terminal of the phase A main rectifier port A-1 and the negative input terminal of the phase A auxiliary voltage-forming port A-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the A-phase auxiliary pressure port A-2 is connected to the B-phase rectifier unit; The high-frequency AC output terminal of the main rectifier port A-1 of phase A is connected in series with the first primary-side power transmission inductor of phase A, and then connected to the two ends of the first primary winding of the high-frequency isolation transformer of phase A. The high-frequency AC output terminal of the auxiliary pressure port A-2 of phase A is connected in series with the second primary power transmission inductor of phase A, and then connected to the two ends of the second primary winding of the high-frequency isolation transformer of phase A. The secondary winding of the high-frequency isolation transformer of phase A is connected in series with the secondary power transmission inductor of phase A, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port A-3 of phase A.

[0036] The B-phase rectifier unit includes a B-phase AC source, a B-phase main rectifier port B-1, a B-phase auxiliary rectifier port B-2, and a B-phase output port B-3. The positive output terminal of the B-phase AC source is connected in series with a B-phase input filter inductor. L B B-phase input damping resistor R B Then, connect to the positive input terminal of the B-1 main rectifier port of phase B; The negative grounding terminal of the phase B AC source is directly short-circuited with the negative input terminal of the main rectifier port B-1 and the negative input terminal of the auxiliary voltage-forming port B-2 of phase B, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the B-2 auxiliary pressure port of phase B is connected to the C-phase rectifier unit; The high-frequency AC output terminal of the B-phase main rectifier port B-1 is connected in series with the first primary-side power transmission inductor of the B-phase, and then connected to both ends of the first primary winding of the high-frequency isolation transformer of the B-phase. The high-frequency AC output terminal of the B-phase auxiliary pressure port B-2 is connected in series with the second primary-side power transmission inductor of the B-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the B-phase. The secondary winding of the high-frequency isolation transformer of phase B is connected in series with the secondary power transmission inductor of phase B, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port B-3 of phase B.

[0037] The C-phase rectifier unit includes a C-phase AC source, a C-phase main rectifier port C-1, a C-phase auxiliary rectifier port C-2, and a C-phase output port C-3; The positive output terminal of the C-phase AC source is connected in series with a C-phase input filter inductor. L C C-phase input damping resistor R C Then, connect it to the positive input terminal of the C-1 main rectifier port; The negative grounding terminal of the C-phase AC source is directly shorted to the negative input terminal of the C-phase main rectifier port C-1 and the negative input terminal of the C-phase auxiliary voltage-forming port C-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The positive input terminal of the C-phase auxiliary pressure port C-2 is connected to the A-phase rectifier unit; The high-frequency AC output terminal of the C-phase main rectifier port C-1 is connected in series with the first primary-side power transmission inductor of the C-phase, and then connected to the two ends of the first primary winding of the high-frequency isolation transformer of the C-phase. The high-frequency AC output terminal of the C-phase auxiliary pressure port C-2 is connected in series with the second primary-side power transmission inductor of the C-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the C-phase. The secondary winding of the high-frequency isolation transformer of phase C is connected in series with the secondary power transmission inductor of phase C, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port C-3 of phase C.

[0038] In some embodiments, the line voltage of phase A rectifier unit is u AB ; The line voltage connected to the B-phase rectifier unit is u BC ; The line voltage connected to the C-phase rectifier unit is u CA ; like Figure 3As shown, taking any phase as an example, the formula for the equivalent input voltage of the main rectifier port of each phase rectifier unit is:

[0039] in, for j The equivalent input voltage of the main rectifier port. for j The auxiliary bias DC voltage at the auxiliary voltage gate of the phase auxiliary structure. The three-phase input line voltages are, where, j =A, B, C; k =A, B, C; j ≠ k ; satisfy: .

[0040] For 380V three-phase AC power The range of variation is [-537, 537]. =600V. At this time, by It can be seen that, The range of variation is [63, 1137], and there is no AC zero-crossing point. Since the auxiliary port 2 is controlled at a set voltage value, as shown in the figure as 600V, the input voltage of port 1 is no longer just a simple three-phase AC line voltage, but an equivalent input voltage formed by the superposition of the line voltage and the auxiliary port voltage. The result of this construction is that the input voltage seen by the main port 1 remains a pulsating voltage with DC bias throughout the entire AC cycle, and its amplitude can avoid crossing the zero point. Since the rate of change of the input inductor current is directly related to the voltage applied across the inductor, when the input voltage is close to the traditional line voltage zero point, the present invention can still maintain a high effective driving voltage with the help of the auxiliary port voltage. Therefore, the input current can still maintain good tracking capability in the zero-crossing range, fundamentally improving the current distortion problem that easily occurs in three-phase rectifiers near the zero point.

[0041] Figure 4 The diagram shows the waveforms of phase-shifting operation at the three ports of phase A; the same applies to phases B and C. For each phase, the port... j -1( j The voltage across points A, B, and C is applied to the input capacitor and bridge arm of this port, and the switching device at this port operates according to... Figure 6 , Figure 7 , Figure 8 The phase-shift control strategy alternately turns the circuit on, forming a high-frequency bridge voltage on the primary winding. ( j =A,B,C); Port j -2( jSimilarly, a high-frequency bridge voltage is formed on the second set of primary windings (A,B,C). ( j =A,B,C); the ports connected to the secondary winding of the transformer. j -3( j The high-frequency bridge voltage formed by (A,B,C) This serves as the reference bridge voltage for phase-shift control. Each phase's AC input side utilizes a port... j -1( j =A,B,C) and port j -2( j The four-switch high-frequency bridge voltage network consisting of A, B, and C directly converts AC power energy into high-frequency pulse energy, which is then fed into the high-frequency transformer. Through transformer energy coupling and phase shift control, single-stage isolation conversion of AC and DC energy is achieved.

[0042] In some embodiments, the main rectifier port j-1, auxiliary rectifier port j-2, and output port j-3 of each phase rectifier unit constitute a three-port power transmission equivalent model, where j = A, B, and C. From an energy transfer perspective, ports 1 and 2 together serve as the input side of this phase, while port 3 serves as the DC output side of this phase. Energy exchange between the three ports is achieved through a high-frequency isolation transformer and a power transfer inductor. The port voltages, which vary with the power frequency within a single switching cycle, are considered constant. Figure 5 The equivalent model for power transmission yields the following formula for the power transmitted between ports:

[0043] in, , , The first j Power transmission between the main rectifier port and the auxiliary rectifier port, between the main rectifier port and the output port, and between the auxiliary rectifier port and the output port; , , The first j Compared to the shifts between the main rectifier port and the auxiliary rectifier port, the main rectifier port and the output port, and the auxiliary rectifier port and the output port, and ; For the first j The turns ratio of a three-phase transformer; f s This refers to the switching frequency of the three-phase rectifier topology; , , The first j The equivalent inductance for power transfer between the main rectifier port and the auxiliary rectifier port, the main rectifier port and the output port, and the auxiliary rectifier port and the output port; The formula for equivalent inductance is:

[0044] The formula for the total transmission power of each port is:

[0045] With output port j The high-frequency bridge voltage of -3 is used as the phase-shift control reference. By controlling the phase shift... D j 13 and D j 23 Adjust the output power of the corresponding phase output port to perform single-stage isolation conversion of AC and DC energy.

[0046] Figure 6 This demonstrates the process by which the phase-shift signal output from the control loop, after carrier modulation, zero-crossing comparison, SR triggering, and dead-time insertion, generates complementary drive signals for the upper and lower bridge arm switches. This corresponds to the process described in this invention. Figure 7 , Figure 8 The phase-shift drive generation module at each port is used to convert the phase shift calculated by the control loop into a phase shift value in the D phase shift driver. j-13 D j-23 ( j =A, B, C) are converted into actual gate drive signals. The control method is also shown, where the output ports 3 of phases A, B, and C are used as phase shift reference ports and their shift ratios are set to zero.

[0047] Figure 7 The power factor correction control for each phase port 1 and the voltage regulation control strategy for each phase port 3 are demonstrated. Taking phase A as an example, the DC output voltage at output port A-3 is first detected. U o-A and with a given reference voltage U ref In comparison, the error signal, after being adjusted by the PI (proportional-integral) controller, generates a reference amplitude for the input current of phase A. Similarly, phases B and C can be obtained respectively. and At the same time, the three-phase line voltages were collected respectively. u AB , u BC , u CA The synchronization phase angle of each phase is extracted via a phase-locked loop (PLL). θ A , θ B , θ CThen, a corresponding unit sine signal sin is generated through a sine circuit. θ A sin θ B sin θ C Multiply the current amplitude command for each phase by the corresponding sinusoidal signal to obtain the input current reference. , , Subsequently, the reference current was compared with the actual current of each phase AC source. i A , i B , i C The difference current error signal, after being adjusted by a PIR (proportional-integral-resonant) controller, forms the shift ratio D between port 1 and port 3 of each phase. A-13 D B-13 D C-13 Simultaneously, an AC input voltage feedforward term can be superimposed. u jk * K ( K (This is an AC line voltage scaling factor) to enhance the system's dynamic response and disturbance rejection performance. Finally, the phase-shift modulator generates the switching drive signals for ports A-1, B-1, and C-1. This control strategy enables port 1 to accurately track the reference current in phase with the AC voltage, achieving high power factor rectification; while the outer loop of port 3 ensures stable output voltage by adjusting the input power requirements of each phase.

[0048] Figure 8 The voltage regulation control for each port 2 and the power sharing control strategy for each phase port 3 are demonstrated. First, the voltage at each phase auxiliary port is... u A-2 , u B-2 , u C-2 Samples were taken and compared with the set reference values ​​respectively. U 2_ref After comparison, the error signals of each phase are sent to a PI (proportional-integral) controller. The purpose of this control loop is to maintain the stability of the voltage at port 2 of each phase, ensuring it continuously provides the bias support voltage required to construct the AC side zero-crossing equivalent input voltage. Because the port voltage is stably controlled, port 1 can maintain a relatively high effective input voltage in the AC input zero-crossing range, thereby improving the input current waveform. Furthermore, when the three-phase module's ports 3 operate in parallel, power sharing control needs to be introduced. Specifically, the parallel output voltage of phase A is used... U o-A With the output current I of each phase OA I OB IOC The output power P of each phase was calculated. A P B P C and compare it with the total given power P ref One-third of the power is compared. The power deviation of each phase is adjusted by another PI (proportional-integral) controller to generate a compensation amount. d 1. d 2. d 3. Add the compensation amount to the corresponding control amount generated by the previous PI controller, and inject them together into the control channel of port 2 to coordinate the power distribution of each phase. This power-sharing control mechanism ensures that the three phase modules maintain a basic power balance when outputting in parallel, preventing any one phase from bearing an excessive load due to parameter differences or control deviations, thus improving the stability and reliability of the system's parallel operation. Finally, the shift ratio D of port 2 relative to port 3 is generated. A-23 D B-23 D C-23 After being modulated by the phase-shifting module, the drive signals for each switch transistor at ports A-2, B-2, and C-2 are generated.

[0049] Please see Figure 9 The diagram shows a control method for a single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration. The method includes the following steps: S1. For three-phase AC input voltage u AB , u BC , u CA Real-time sampling is performed and fed into the phase-locked loop (PLL) to extract the synchronization phase information of phases A, B, and C. θ A , θ B , θ C The sinusoidal signal of each phase is obtained through the sinusoidal signal generation stage. θ A sin θ B sin θ C , serving as a phase reference for the AC input current of each phase; S2. DC output voltage at each phase output port U o-A , U o-B , U o-C Perform real-time sampling and compare it with the preset output voltage setpoint. U refThe comparison results in an error signal that is then adjusted by an outer voltage loop PI controller to generate an amplitude setpoint signal for the inner loop of the AC input current for each phase. , and ; S3. Multiply the amplitude reference signal of the inner loop of the AC input current for each phase by the unit sine signal of each phase to generate the reference value of the AC input current for each phase. , , Compare the reference values ​​of the AC input current for each phase with the actual input current. i A , i B , i C The current error signal is obtained by subtraction, and then sent to the PIR controller for adjustment. An AC line voltage feedforward term is added to obtain the shift ratio D of each phase's main rectifier port relative to the output port. A-13 D B-13 D C-13 After being processed by the phase-shifting drive module, the phase-shifting phase generates drive signals for each power switching device inside the A-phase main rectifier port A-1, the B-phase main rectifier port B-1, and the C-phase main rectifier port C-1, so as to track the input current against the reference sinusoidal signal and correct the power factor on the AC input side. In step S3: The AC line voltage feedforward term is: u jk * K ; in, j , k =A, B, C, and j ≠ k, K This is the preset AC line voltage scaling factor.

[0050] S4. Port voltages at the auxiliary voltage-suppressing ports of each phase. u A-2 , u B-2 , u C-2 Real-time sampling is performed, compared with the preset auxiliary port voltage setpoint. U 2_ref The voltage error signal is obtained by comparison. After the error signal is adjusted by the respective PI controller, the voltage regulation control quantity of each phase auxiliary port is generated to maintain the voltage stability of the auxiliary voltage construction port and continuously provide the bias support required to construct the AC side non-zero equivalent input voltage. S5. Output current I at each phase output port OA I OB I OCSampling is performed, and the output power P of each phase is calculated based on the corresponding DC output voltage. A P B P C The output power of each phase is compared with the total reference power P. ref The power error signal is compared with 1 / 3 of the power, and then adjusted by the power sharing PI controller to generate the power sharing compensation for each phase. d 1. d 2. d 3. Add the compensation amount to the corresponding phase's auxiliary port voltage regulation control amount to obtain the shift ratio D of each phase's auxiliary voltage regulation port relative to the output port. A-23 D B-23 D C-23 After being processed by the phase-shifting drive module, drive signals are generated for each power switching device inside the A-phase auxiliary pressure port A-2, the B-phase auxiliary pressure port B-2, and the C-phase auxiliary pressure port C-2, so as to realize the voltage regulation of the auxiliary pressure port and the power control of the three-phase parallel output. S6. The phase shift ratio of the output port of each phase rectifier unit is fixed at 0 as the phase shift control reference for the three-port power transmission of the corresponding phase. The power magnitude and direction of the main rectifier power channel are adjusted by adjusting the phase shift ratio between the main rectifier port and the output port of each phase. The power magnitude and direction of the auxiliary rectifier power channel are adjusted by adjusting the phase shift ratio between the auxiliary rectifier port and the output port.

[0051] S7. Repeat steps S1-S6 during the AC input operating cycle to continuously update the shift ratio and drive signal of each power switching device, thereby achieving three-phase AC input power factor correction, auxiliary voltage port regulation, output port regulation, and three-phase parallel output power control until the converter operates stably in the set operating state.

[0052] It should be understood that the sequence number of each step in the above embodiments does not imply the 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 the present invention.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration, characterized in that, The device includes: The three rectifier units are A-phase, B-phase, and C-phase. They are independent of each other and are coupled in parallel on the DC side. Each of the three rectifier units includes a main rectifier port on the AC side, an auxiliary rectifier port on the AC side, and an output port on the DC side. The main rectifier port and the auxiliary voltage conversion port are located on the AC input side and are connected in a common negative ground manner. The main rectifier port and the auxiliary voltage conversion port are coupled to the corresponding primary winding of the high-frequency isolation transformer through a high-frequency bridge converter unit. The output port is coupled to the secondary winding of the high-frequency isolation transformer, and together with the main rectifier port and the auxiliary voltage conversion port, it forms a single-stage AC-DC power conversion link. The DC sides of the output ports of the three-phase rectifier units are connected in parallel to form a common DC output terminal; The A-phase rectifier unit includes an A-phase AC source, an A-phase main rectifier port A-1, an A-phase auxiliary rectifier port A-2, and an A-phase output port A-3; the B-phase rectifier unit includes a B-phase AC source, a B-phase main rectifier port B-1, a B-phase auxiliary rectifier port B-2, and a B-phase output port B-3; the C-phase rectifier unit includes a C-phase AC source, a C-phase main rectifier port C-1, a C-phase auxiliary rectifier port C-2, and a C-phase output port C-3; the positive input terminal of the A-phase auxiliary rectifier port A-2 is connected to the B-phase AC source. The rectifier unit has its phase B auxiliary voltage port B-2 connected to the phase C rectifier unit, and its phase C auxiliary voltage port C-2 connected to the phase A rectifier unit. The auxiliary voltage ports are used to output a stable DC bias voltage, which is superimposed on the corresponding three-phase AC line voltage to construct a DC bias-free equivalent input voltage for the main rectifier port. The shift ratio of phase A auxiliary voltage port A-2, phase B auxiliary voltage port B-2, and phase C auxiliary voltage port C-2 relative to their corresponding output ports is D. A-23 D B-23 D C-23 ;D A-23 D B-23 D C-23 The voltage regulation control quantity of the corresponding phase's auxiliary port and the power sharing compensation quantity of the corresponding phase. d 1. d 2. d The power sharing compensation amount is obtained by adding the three together. d 1. d 2. d 3. By comparing the output power of each phase with the total reference power P ref The power error signal is compared with 1 / 3 of the average power and then adjusted by a power PI controller; the power error signal is generated by shifting the ratio D. A-23 D B-23 D C-23 This enables voltage stabilization at the auxiliary pressure port and power equalization control of the three-phase parallel output.

2. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 1, characterized in that, The main rectifier port on the AC side and the auxiliary rectifier port on the AC side of each phase rectifier unit adopt a half-bridge high-frequency bridge converter structure. Each port includes two high-frequency power switching transistors connected in series, freewheeling diodes connected in reverse parallel with each switching transistor, voltage equalization and balancing capacitors connected in parallel with each switching transistor, and port input filter capacitors connected in parallel at the half-bridge input terminal. Each phase rectifier unit is equipped with a high-frequency isolation transformer. The transformer includes two sets of independent primary windings and one set of secondary windings. The two sets of primary windings are connected in series with the midpoint of the half-bridge output of the main rectifier port and the auxiliary rectifier port, respectively. Primary power transmission inductors are provided in the series branches. The DC-side output port adopts a full-bridge high-frequency bridge converter structure, which includes four high-frequency power switches connected in series and then in parallel, freewheeling diodes connected in reverse parallel with each switch, and an output filter capacitor connected in parallel at the full-bridge output. The full-bridge input is connected in series with the transformer secondary winding and the secondary power transfer inductor to form a closed loop. The main rectifier port is used for main power transmission and power factor correction; the output port is used for phase shift reference, output voltage regulation and energy collection.

3. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 2, characterized in that, The positive output terminal of the A-phase AC source is connected in series with the A-phase input filter inductor. L A Phase A input damping resistor R A Then, connect it to the positive input terminal of the main rectifier port A-1 of phase A; The negative grounding terminal of the phase A AC source is directly shorted to the negative input terminal of the phase A main rectifier port A-1 and the negative input terminal of the phase A auxiliary voltage-forming port A-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The high-frequency AC output terminal of the main rectifier port A-1 of phase A is connected in series with the first primary-side power transmission inductor of phase A, and then connected to the two ends of the first primary winding of the high-frequency isolation transformer of phase A. The high-frequency AC output terminal of the auxiliary pressure port A-2 of phase A is connected in series with the second primary power transmission inductor of phase A, and then connected to the two ends of the second primary winding of the high-frequency isolation transformer of phase A. The secondary winding of the high-frequency isolation transformer of phase A is connected in series with the secondary power transmission inductor of phase A, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port A-3 of phase A.

4. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 2, characterized in that, The positive output terminal of the B-phase AC source is connected in series with a B-phase input filter inductor. L B B-phase input damping resistor R B Then, connect to the positive input terminal of the B-1 main rectifier port of phase B; The negative grounding terminal of the phase B AC source is directly shorted to the negative input terminal of the main rectifier port B-1 and the negative input terminal of the auxiliary voltage-forming port B-2 of phase B, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The high-frequency AC output terminal of the B-phase main rectifier port B-1 is connected in series with the first primary-side power transmission inductor of the B-phase, and then connected to both ends of the first primary winding of the high-frequency isolation transformer of the B-phase. The high-frequency AC output terminal of the B-phase auxiliary pressure port B-2 is connected in series with the second primary-side power transmission inductor of the B-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the B-phase. The secondary winding of the high-frequency isolation transformer of phase B is connected in series with the secondary power transmission inductor of phase B, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port B-3 of phase B.

5. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 2, characterized in that, The positive output terminal of the C-phase AC source is connected in series with a C-phase input filter inductor. L C C-phase input damping resistor R C Then, connect it to the positive input terminal of the C-1 main rectifier port; The negative grounding terminal of the C-phase AC source is directly shorted to the negative input terminal of the C-phase main rectifier port C-1 and the negative input terminal of the C-phase auxiliary voltage-forming port C-2, forming a connection structure with the negative terminals of the same phase dual ports sharing a common ground. The high-frequency AC output terminal of the C-phase main rectifier port C-1 is connected in series with the first primary-side power transmission inductor of the C-phase, and then connected to both ends of the first primary winding of the high-frequency isolation transformer of the C-phase. The high-frequency AC output terminal of the C-phase auxiliary pressure port C-2 is connected in series with the second primary-side power transmission inductor of the C-phase, and then connected to the two ends of the second primary-side winding of the high-frequency isolation transformer of the C-phase. The secondary winding of the high-frequency isolation transformer of phase C is connected in series with the secondary power transmission inductor of phase C, and then connected to the AC input terminal of the full-bridge high-frequency bridge converter structure at the DC output port C-3 of phase C.

6. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 1, characterized in that, The line voltage connected to phase A rectifier unit is u AB ; The line voltage connected to the B-phase rectifier unit is u BC ; The line voltage connected to the C-phase rectifier unit is u CA ; The formula for the equivalent input voltage at the main rectifier port of each phase rectifier unit is: in, for j The equivalent input voltage of the main rectifier port. for j The auxiliary bias DC voltage at the auxiliary voltage gate of the phase auxiliary structure. The three-phase input line voltages are, where, j =A, B, C; k =A, B, C; j ≠ k ; satisfy: 。 7. The single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 1, characterized in that, The main rectifier port j-1, auxiliary rectifier port j-2, and output port j-3 of each phase rectifier unit constitute a three-port power transmission equivalent model, where j = A, B, and C. Energy exchange between the three ports is accomplished through a high-frequency isolation transformer and a power transfer inductor. The port voltage, which varies with the power frequency during a single switching cycle, is considered constant. The formula for the power transferred between the ports is as follows: in, for j The equivalent input voltage of the main rectifier port. for j The auxiliary bias DC voltage at the auxiliary voltage gate of the phase auxiliary structure. , , The first j Power transmission between the main rectifier port and the auxiliary rectifier port, between the main rectifier port and the output port, and between the auxiliary rectifier port and the output port; , , The first j Compared to the shifts between the main rectifier port and the auxiliary rectifier port, the main rectifier port and the output port, and the auxiliary rectifier port and the output port, and ; For the first j The turns ratio of a three-phase transformer; f s This refers to the switching frequency of the three-phase rectifier topology; , , The first j The equivalent inductance for power transfer between the main rectifier port and the auxiliary voltage-converting port, the main rectifier port and the output port, and the auxiliary voltage-converting port and the output port; the formula for the total power transferred at each port is: With output port j The high-frequency bridge voltage of -3 is used as the phase-shift control reference. By controlling the phase shift... D j 13 and D j 23 Adjust the output power of the corresponding phase output port to perform single-stage isolation conversion of AC and DC energy.

8. A control method for a single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration, characterized in that, The method is based on the apparatus according to any one of claims 1-7, and the method includes the following steps: S1. For three-phase AC input voltage u AB , u BC , u CA Real-time sampling is performed and fed into the phase-locked loop (PLL) to extract the synchronization phase information of phases A, B, and C. θ A , θ B , θ C The sinusoidal signal of each phase is obtained through the sinusoidal signal generation stage. θ A sin θ B sin θ C , serving as a phase reference for the AC input current of each phase; S2. DC output voltage at each phase output port U o-A , U o-B , U o-C Perform real-time sampling and compare it with the preset output voltage setpoint. U ref The comparison results in an error signal that is then adjusted by an outer voltage loop PI controller to generate an amplitude setpoint signal for the inner loop of the AC input current for each phase. , and ; S3. Multiply the amplitude reference signal of the inner loop of the AC input current for each phase by the unit sine signal of each phase to generate the reference value of the AC input current for each phase. , , Compare the reference values ​​of the AC input current for each phase with the actual input current. i A , i B , i C The current error signal is obtained by subtraction, and then sent to the PIR controller for adjustment. An AC line voltage feedforward term is added to obtain the shift ratio D of each phase's main rectifier port relative to the output port. A-13 D B-13 D C-13 After being processed by the phase-shifting drive module, the phase-shifting phase generates drive signals for each power switching device inside the A-phase main rectifier port A-1, the B-phase main rectifier port B-1, and the C-phase main rectifier port C-1, so as to track the input current against the reference sinusoidal signal and correct the power factor on the AC input side. S4. Port voltages at the auxiliary voltage-suppressing ports of each phase. u A-2 , u B-2 , u C-2 Real-time sampling is performed, compared with the preset auxiliary port voltage setpoint. U 2_ref The voltage error signal is obtained by comparison. After the error signal is adjusted by the respective PI controller, the voltage regulation control quantity of each phase auxiliary port is generated to maintain the voltage stability of the auxiliary voltage construction port and continuously provide the bias support required to construct the AC side non-zero equivalent input voltage. S5. Output current I at each phase output port OA I OB I OC Sampling is performed, and the output power P of each phase is calculated based on the corresponding DC output voltage. A P B P C The output power of each phase is compared with the total reference power P. ref The power error signal is compared with 1 / 3 of the power, and then adjusted by the power sharing PI controller to generate the power sharing compensation for each phase. d 1. d 2. d 3. Add the compensation amount to the corresponding phase's auxiliary port voltage regulation control amount to obtain the shift ratio D of each phase's auxiliary voltage regulation port relative to the output port. A-23 D B-23 D C-23 After being processed by the phase-shifting drive module, drive signals are generated for each power switching device inside the A-phase auxiliary pressure port A-2, the B-phase auxiliary pressure port B-2, and the C-phase auxiliary pressure port C-2, so as to realize the voltage regulation of the auxiliary pressure port and the power control of the three-phase parallel output. S6. The phase shift ratio of the output port of each phase rectifier unit is fixed at 0 as the phase shift control reference for the three-port power transmission of the corresponding phase. The power magnitude and direction of the main rectifier power channel are adjusted by adjusting the phase shift ratio between the main rectifier port and the output port of each phase. The power magnitude and direction of the auxiliary rectifier power channel are adjusted by adjusting the phase shift ratio between the auxiliary rectifier port and the output port.

9. The control method for the single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 8, characterized in that, In step S3: The AC line voltage feedforward term is: u jk K ; in, j , k =A, B, C, and j ≠ k, K This is the preset AC line voltage scaling factor.

10. The control method for the single-stage isolated three-phase rectifier with AC-side dual-port cooperative voltage configuration according to claim 8, characterized in that, The method further includes the following steps: S7. Repeat steps S1-S6 during the AC input operating cycle to continuously update the shift ratio and drive signal of each power switching device, thereby achieving three-phase AC input power factor correction, auxiliary voltage port regulation, output port regulation, and three-phase parallel output power control until the converter operates stably in the set operating state.

Images