Power converter, power conversion method and shore-based power supply equipment
By employing a two-stage voltage conversion topology of DC-DC converter circuit and resonant transformer rectifier circuit in the shore power supply equipment, combined with PID voltage and current closed-loop control, the problem of low power conversion efficiency is solved, and efficient and stable power conversion and system safety are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FIBERHOME MARINE NETWORK EQUIP CO LTD
- Filing Date
- 2026-01-21
- Publication Date
- 2026-05-01
AI Technical Summary
In existing shore-based power supply equipment, the power converter adopts a topology of DC-DC converter circuit and phase-shifted full-bridge circuit, which results in low power conversion efficiency, making it difficult to reach more than 90%.
A two-stage voltage conversion topology, consisting of a DC-DC converter circuit and a resonant transformer rectifier circuit, combined with PID voltage and current closed-loop control, is used to achieve efficient driving and stable output of the power converter.
It significantly improves power conversion efficiency to over 92%, while ensuring the stability of output current and system safety, providing a natural fault isolation barrier.
Smart Images
Figure CN121966276A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of submarine cable power supply technology, and in particular to a power converter, a power conversion method, and shore-based power supply equipment. Background Technology
[0002] Shore-based power supply equipment (PFE) is a core component of submarine observation networks and relayed optical transmission networks. Typically housed in a shore-based equipment room, PFE converts 48V low-voltage DC power into 18KV constant-current high-voltage DC output to provide stable power to underwater equipment and submarine cables. The shore-based submarine cable power supply system comprises multiple power converters connected in series, outputting a total voltage (constant-current high-voltage DC) to the submarine cable. Existing shore-based power supply equipment for submarine cables primarily employs DC-DC converters (boost circuits) and phase-shifted full-bridge circuits in its power converter topologies. However, the phase-shifted full-bridge circuit significantly reduces switching losses, limiting the power conversion efficiency to a maximum of 88%, which falls short of the over 90% required for optimal efficiency. Therefore, improvements to the power converters in existing shore-based power supply equipment are urgently needed to enhance power conversion efficiency. Summary of the Invention
[0003] This invention provides a power converter, a power conversion method, and a shore-based power supply device to solve the technical problem of low power conversion efficiency in existing shore-based power supply devices that supply power to submarine cables, which use DC-DC converter circuits and phase-shifted full-bridge circuit topologies.
[0004] In a first aspect, a power converter is provided, comprising: a DC-DC converter circuit, a resonant transformer rectifier circuit, and a control circuit; The input terminal of the DC-DC converter is connected to a power supply, the output terminal of the DC-DC converter is connected to the input terminal of the resonant transformer rectifier circuit, the output terminal of the resonant transformer rectifier circuit is connected to a submarine cable, and the control circuit is connected to the DC-DC converter and the resonant transformer rectifier circuit. The control circuit is configured as follows: In response to the submarine cable power supply command, a first PWM signal and a second PWM signal are generated, and the DC-DC converter circuit and the resonant transformer rectifier circuit are driven accordingly based on the first PWM signal and the second PWM signal.
[0005] In some embodiments, the power converter further includes: The circuit includes a medium-voltage detection circuit and a high-voltage detection circuit. The medium-voltage detection circuit is connected to the output terminal of the DC-DC converter circuit and the control circuit. The high-voltage detection circuit is connected to the output terminal of the resonant transformer rectifier circuit and the control circuit. The control circuit is also configured to: The voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit are acquired in real time. The first PWM signal is adjusted according to the voltage and current at the output terminal of the DC-DC converter circuit, and the second PWM signal is adjusted according to the voltage and current at the output terminal of the resonant transformer rectifier circuit.
[0006] In some embodiments, adjusting the first PWM signal based on the voltage and current at the output of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the resonant transformer rectifier circuit.
[0007] In some embodiments, the DC-DC converter circuit is a BUCK-BOOST DC-DC converter circuit.
[0008] In some embodiments, the resonant transformer rectifier circuit includes multiple resonant transformer rectifier sub-circuits connected in series, each of which includes a resonant transformer circuit, an isolation transformer circuit, and a rectifier circuit connected in sequence.
[0009] In some embodiments, the resonant converter circuit is an LLC resonant converter circuit.
[0010] Secondly, a power conversion method is provided, including the following steps: In response to the submarine cable power supply command, a first PWM signal and a second PWM signal are generated; The DC-DC converter circuit and the resonant transformer rectifier circuit are driven by the first PWM signal and the second PWM signal.
[0011] In some embodiments, after driving the DC-DC converter circuit and the resonant transformer rectifier circuit according to the first PWM signal and the second PWM signal respectively, the following steps are included: Real-time acquisition of the voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit, and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit; The first PWM signal is adjusted according to the voltage and current at the output of the DC-DC converter circuit, and the second PWM signal is adjusted according to the voltage and current at the output of the resonant transformer rectifier circuit.
[0012] In some embodiments, adjusting the first PWM signal based on the voltage and current at the output of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the output voltage and current of the resonant transformer rectifier circuit.
[0013] Thirdly, a shore-based power supply device is provided, comprising multiple of the aforementioned power converters.
[0014] The beneficial effects of the technical solution provided by this invention include: This invention provides a power converter, a power conversion method, and a shore-based power supply device. The power converter includes a DC-DC converter circuit, a resonant transformer-rectifier circuit, and a control circuit. The input terminal of the DC-DC converter circuit is connected to a power source, and the output terminal of the DC-DC converter circuit is connected to the input terminal of the resonant transformer-rectifier circuit. The output terminal of the resonant transformer-rectifier circuit is connected to a submarine cable. The control circuit is connected to the DC-DC converter circuit and the resonant transformer-rectifier circuit. The control circuit is configured to: generate a first PWM signal and a second PWM signal in response to a submarine cable power supply command; and drive the DC-DC converter circuit and the resonant transformer-rectifier circuit according to the first PWM signal and the second PWM signal. The power converter of this invention adopts a two-stage voltage conversion topology of a DC-DC converter circuit and a resonant transformer-rectifier circuit, which can effectively improve the power conversion efficiency. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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.
[0016] Figure 1 A schematic block diagram of a power converter provided in an embodiment of the present invention; Figure 2 Another schematic diagram of a power converter provided in an embodiment of the present invention; Figure 3 A closed-loop control flowchart of a DC-DC converter circuit for a power converter provided in an embodiment of the present invention; Figure 4 A closed-loop control flowchart of a resonant transformer rectifier circuit for a power converter provided in an embodiment of the present invention; Figure 5A circuit diagram of a DC-DC converter circuit and a resonant transformer rectifier circuit for a power converter provided in an embodiment of the present invention; Figure 6 This is a schematic flowchart of a power conversion method provided in an embodiment of the present invention; Figure 7 This is another schematic flowchart of a power conversion method provided in an embodiment of the present invention; Figure 8 A schematic diagram of a shore-based power supply device provided in an embodiment of the present invention; Figure 9 This is another structural schematic diagram of a shore-based power supply device provided in an embodiment of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] This invention provides a power converter that solves the technical problem of low power conversion efficiency in existing shore-based power supply equipment for supplying power to submarine cables, which uses a DC-DC converter circuit and a phase-shifting full-bridge circuit topology.
[0019] See Figure 1 As shown, an embodiment of the present invention provides a power converter, including: a DC-DC converter circuit, a resonant transformer rectifier circuit, and a control circuit.
[0020] The input terminal of the DC-DC converter is connected to a power supply, the output terminal of the DC-DC converter is connected to the input terminal of the resonant transformer rectifier circuit, the output terminal of the resonant transformer rectifier circuit is connected to a submarine cable, and the control circuit is connected to the DC-DC converter and the resonant transformer rectifier circuit. The control circuit is configured as follows: In response to the submarine cable power supply command, a first PWM signal and a second PWM signal are generated; The DC-DC converter circuit and the resonant transformer rectifier circuit are driven by the first PWM signal and the second PWM signal. Here, PWM signal refers to pulse width modulation signal.
[0021] Specifically, the control circuit includes a DC-DC converter drive circuit, a resonant converter drive circuit, and a controller. The DC-DC converter drive circuit is connected to both the DC-DC converter circuit and the controller, and the resonant converter drive circuit is connected to both the resonant transformer rectifier circuit and the controller. The controller generates a first PWM signal and a second PWM signal in response to the submarine cable power supply command, and inputs the first PWM signal and the second PWM signal to the DC-DC converter drive circuit and the resonant converter drive circuit, respectively. The DC-DC converter circuit can convert DC48V DC voltage to DC0V-DC270V DC voltage, and the resonant transformer rectifier circuit further converts the DC0V-DC270V DC voltage to DC3kV DC voltage for output.
[0022] The DC-DC converter circuit transforms the unstable input voltage into a stable, adjustable intermediate DC bus voltage. This stage operates at a relatively low frequency without isolation and can employ mature soft-switching technologies (such as zero-voltage switching (ZVS) and zero-current switching (ZCS)) to significantly reduce the turn-on and turn-off losses of the switching devices. The resonant transformer rectifier circuit electrically isolates the intermediate bus voltage output from the previous stage through a high-frequency transformer and accurately converts it into the required load voltage. This resonant transformer rectifier circuit can also employ mature soft-switching technology, virtually eliminating switching losses, especially at high frequencies. In other words, the power converter in this embodiment of the invention uses a two-stage topology of DC-DC converter and resonant transformer rectifier circuit, which can effectively improve the power conversion efficiency. Furthermore, a pre-charge circuit can be provided between the input terminal of the DC-DC converter circuit and the power supply.
[0023] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 2 As shown, the power converter further includes a medium-voltage detection circuit and a high-voltage detection circuit. The medium-voltage detection circuit is connected to the output terminal of the DC-DC converter circuit and the control circuit, and the high-voltage detection circuit is connected to the output terminal of the resonant transformer rectifier circuit and the control circuit. The control circuit is also configured to: The voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit are acquired in real time. The first PWM signal (PWM1) is adjusted according to the voltage and current at the output terminal of the DC-DC converter circuit, and the second PWM signal (PWM2) is adjusted according to the voltage and current at the output terminal of the resonant transformer rectifier circuit.
[0024] The power converter in this embodiment of the invention acquires the voltage and current at the output terminals of the DC-DC converter circuit and the resonant transformer rectifier circuit in real time by setting up a medium-voltage detection circuit and a high-voltage detection circuit. Based on the voltage and current at the output terminals of the DC-DC converter circuit and the resonant transformer rectifier circuit, two closed-loop controls are performed. The first-stage closed-loop control can adjust the power and stabilize the intermediate bus, while the second-stage closed-loop control can accurately regulate the voltage and provide electrical isolation, thus maintaining the stability of the output current while ensuring power conversion efficiency.
[0025] As an optional implementation, in one embodiment of the invention, adjusting the first PWM signal based on the voltage and current at the output terminal of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output terminal of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the resonant transformer rectifier circuit.
[0026] Specifically, see Figure 3 As shown, the process of using PID voltage-current closed-loop control to regulate the first PWM signal to control the DC-DC converter circuit in the preceding stage is as follows: The voltage and current at the output terminal of the preceding DC-DC converter circuit are acquired from the output side of the DC-DC converter circuit. The acquired voltage V1 at the output terminal of the preceding DC-DC converter circuit is compared with a reference voltage. The voltage V_ref1 is compared to obtain the voltage error Vdif1 (which varies with time). This voltage error Vdif1 is then fed into the voltage loop PID controller (or typically a PI controller) in the preceding PID voltage-current closed-loop control system, which outputs a reference current I_ref1. The current I1 at the output of the resonant transformer rectifier circuit is then compared with the reference current I_ref1 to obtain the current error Idif1 (which varies with time). This current error Idif1 is then fed into the current loop PID controller (or typically a PI controller) in the preceding PID voltage-current closed-loop control system, which outputs a duty cycle reference value Duty_ref, generating the corresponding first PWM signal. This signal then controls the switching (transistor) of the preceding DC-DC converter circuit. Where: I_ref1(t)=Kp1×Vdif1(t)+Ki1×∫Vdif1(t)dt+Kd1×dVdif1(t) / dt; Duty_ref1(t)=Kp2×Idif1(t)+Ki2×∫Idif1(t)dt+Kd2×dIdif1(t) / dt; Kp1 and Kp2 are proportional coefficients, Ki1 and Ki2 are integral gains, and Kd1 and Kd2 are differential gains.
[0027] When the system requires a large dynamic response (e.g., a sudden load increase), the downstream resonant transformer rectifier circuit will instantly draw more power to maintain a stable high-voltage output, causing the intermediate bus voltage (the voltage at the output of the upstream DC-DC converter circuit) to drop. At this time, the voltage loop error of the upstream stage increases, which will immediately instruct the current loop to increase the input current, improve power delivery, and support the intermediate bus voltage.
[0028] See Figure 4 As shown, the process of using PID voltage and current closed-loop control to regulate the second PWM signal to control the subsequent resonant transformer rectifier circuit is as follows: The voltage and current at the output terminal of the resonant transformer rectifier circuit are acquired from the high-voltage output side. The acquired voltage V2 at the output terminal of the resonant transformer rectifier circuit is compared with the reference voltage V_ref2 to obtain the voltage error Vdif2 (which varies with time). The voltage error Vdif2 is sent to the voltage loop PID controller (generally, only a PI controller can be used) in the subsequent PID voltage-current closed-loop control to output a reference current I_ref2. The acquired current I2 at the output terminal of the resonant transformer rectifier circuit is then compared with the reference current I_ref2 to obtain the current error Idif2 (which varies with time). The current error Idif2 is sent to the current loop PID controller (generally, only a PI controller can be used) in the subsequent PID voltage-current closed-loop control to output the duty cycle reference value Duty_ref2, generating a corresponding second PWM signal. This signal then controls the switching (transistor) of the subsequent resonant transformer rectifier circuit. When the output voltage is low, the switching frequency is reduced and the gain is increased to raise the output voltage, and vice versa. Wherein: I_ref2(t)=Kp3×Vdif2(t)+Ki3×∫Vdif2(t)dt+Kd3×dVdif2(t) / dt; Duty_ref2(t)=Kp4×Idif2(t)+Ki4×∫Idif2(t)dt+Kd4×dIdif2(t) / dt; Kp3 and Kp4 are proportional coefficients, Ki3 and Ki4 are integral gains, and Kd3 and Kd4 are differential gains.
[0029] This invention, through ingenious topology combination and control logic, ensures both power conversion efficiency and stable output current. The front-stage DC-DC converter circuit effectively handles wide-range fluctuations in the input voltage of 48V (e.g., 38V-60V), operating stably regardless of whether the input voltage is below, equal to, or above the set value of the intermediate bus voltage. This ensures a stable input for the subsequent resonant transformer rectifier circuit. By controlling the bus voltage, input or output power can be actively limited, facilitating power management, overload protection, and sequential power-on. The subsequent resonant transformer rectifier circuit easily implements zero-voltage switching and zero-current switching in the switching power supply. For high-voltage rectifier circuits, it significantly reduces diode stress and improves reliability. Furthermore, the two-stage topology provides a natural fault isolation barrier; a fault in the front stage will not cause uncontrolled high-voltage output, and a fault in the subsequent stage will not directly impact the input. Protection strategies can be layered for greater precision and safety.
[0030] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 5 As shown, the DC-DC converter circuit is a BUCK-BOOST DC-DC converter circuit. Specifically, the DC-DC converter circuit adopts a BUCK-BOOST DC-DC converter circuit, including a first transistor Q1, a first inductor L1, a first capacitor C1, and a first diode D1. The first terminal of the first transistor Q1 is connected to the negative terminal of the power supply, and the second terminal of the first transistor Q1 is connected to the negative terminal of the first diode D1. The first terminal of the first inductor L1 is connected to the positive terminal of the power supply, and the second terminal of the first inductor L1 is connected to the second terminal of the first transistor Q1. The first terminal of the first capacitor C1 is connected to the first terminal of the first inductor L1, and the second terminal of the first capacitor C1 is connected to the second terminal of the first inductor L1. The first and second terminals of the first capacitor C1 are connected to the input terminal of the resonant transformer rectifier circuit. The BUCK-BOOST DC-DC converter circuit can use mature soft-switching technology, which significantly reduces the turn-on and turn-off losses of the switching devices.
[0031] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 5 As shown, the resonant transformer rectifier circuit includes multiple resonant transformer rectifier sub-circuits connected in series. Each resonant transformer rectifier sub-circuit includes a resonant converter circuit, an isolation transformer circuit, and a rectifier circuit connected in sequence. The resonant converter circuit is an LLC resonant converter circuit, and the rectifier circuit is a full-bridge rectifier circuit. The resonant converter circuit includes a second transistor Q2, a third transistor Q3, a second inductor L2, a second capacitor C2, and a third capacitor C3. The isolation transformer circuit includes a transformer T1.
[0032] The first terminal of the second transistor Q2 is connected to the first terminal of the first capacitor C1. The second terminal of the second transistor Q2 is connected to the first terminal of the third transistor Q3. The second terminal of the third transistor Q3 is connected to the second terminal of the first capacitor C1. The first terminal of the second capacitor C2 is connected to the first terminal of the first capacitor C1. The second terminal of the second capacitor C2 is connected to the first terminal of the third capacitor C3. The second terminal of the third capacitor C3 is connected to the second terminal of the first capacitor C1. The first terminal of the second inductor L2 is connected to the second terminal of the second transistor Q2 and the first terminal of the third transistor Q3. The first terminal of the second inductor L2 is connected to the first terminal of the primary coil of the transformer T1. The second terminal of the primary coil of the transformer T1 is connected to the second terminal of the second capacitor C2 and the first terminal of the third capacitor C3. The secondary coil of the transformer T1 is connected to a rectifier circuit. The resonant transformer rectifier circuit electrically isolates the intermediate bus voltage output from the front stage through a high-frequency transformer and accurately converts it into the required load voltage. Furthermore, the resonant transformer rectifier circuit utilizes the resonance between the inductor, capacitor, and transformer magnetizing inductor to enable the transistor to turn on or off under zero voltage / zero current conditions, thereby virtually eliminating switching losses.
[0033] This invention employs a two-stage conversion structure using a BUCK-BOOST DC-DC converter circuit and an LLC resonant transformer rectifier circuit. The DC 48V power supply first undergoes a buck-boost DC-DC converter circuit to achieve a step-up / buck conversion (low voltage to medium voltage), outputting DC 0V~DC 270V DC voltage. Then, a multi-stage series resonant transformer rectifier circuit (three stages in series in the diagram) transforms the DC 0V~DC 270V DC voltage through resonant conversion, isolation transformation, and rectification, outputting multiple stable DC 1kV DC voltages. In the diagram, the three DC 1kV DC voltages are connected in series and filtered by capacitors to output DC 3kV (medium voltage to high voltage). The conversion efficiency of the BUCK-BOOST circuit is approximately 94% (92%~96%), and the conversion efficiency of the LLC resonant converter circuit is approximately 98%, with an overall efficiency exceeding 92%.
[0034] See Figure 6 As shown, this embodiment of the invention provides a power conversion method, including the following steps: Step S10: Generate a first PWM signal and a second PWM signal in response to the submarine cable power supply command; Step S20: Drive the DC-DC converter circuit and the resonant transformer rectifier circuit according to the first PWM signal and the second PWM signal.
[0035] The power conversion method of this invention adopts a two-stage topology of DC-DC converter circuit and resonant transformer rectifier circuit, which can effectively improve the power conversion efficiency.
[0036] As an optional implementation, in one embodiment of the invention, see [link to relevant documentation]. Figure 7 As shown, after driving the DC-DC converter circuit and the resonant transformer rectifier circuit according to the first PWM signal and the second PWM signal respectively, the following steps are included: Step S30: Real-time acquisition of the voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit, and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit. Step S40: Adjust the first PWM signal according to the voltage and current at the output of the DC-DC converter circuit, and adjust the second PWM signal according to the voltage and current at the output of the resonant transformer rectifier circuit.
[0037] In this embodiment of the invention, the voltage and current at the output terminals of the DC-DC converter circuit and the resonant transformer rectifier circuit are acquired in real time. Based on the voltage and current at the output terminals of the DC-DC converter circuit and the resonant transformer rectifier circuit, two closed-loop controls are performed. The first-stage closed-loop control can adjust the power and stabilize the intermediate bus, while the second-stage closed-loop control can accurately regulate the voltage and provide electrical isolation, thus maintaining the stability of the output current while ensuring power conversion efficiency.
[0038] As an optional implementation, in one embodiment of the invention, adjusting the first PWM signal based on the voltage and current at the output terminal of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output terminal of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the output voltage and current of the resonant transformer rectifier circuit.
[0039] This invention provides a shore-based power supply device, including multiple power converters and a main control device as described above.
[0040] See Figure 8 and Figure 9As shown, multiple power converters are connected in series at the 48V input terminal to achieve a 18KV high-voltage output. Each power converter communicates with the main control unit of the shore-based power supply equipment via a CAN bus. The main control unit simultaneously monitors the current and voltage status of the total output and handles alarm management. The main control unit can employ a digital signal processing (DSP) controller for communication control with each power converter and submarine cable output unit. Alternatively, a high-performance ARM controller can interact with the DSP controller via an SPI bus. Simultaneously, the ARM controller communicates with the host computer via an Ethernet bus or RS485 bus to achieve human-machine interaction.
[0041] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.
[0042] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0043] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement 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 present 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 of the invention herein.
Claims
1. A power converter, characterized in that, include: DC-DC converter circuit, resonant transformer rectifier circuit and control circuit; The input terminal of the DC-DC converter is connected to a power supply, the output terminal of the DC-DC converter is connected to the input terminal of the resonant transformer rectifier circuit, the output terminal of the resonant transformer rectifier circuit is connected to a submarine cable, and the control circuit is connected to the DC-DC converter and the resonant transformer rectifier circuit. The control circuit is configured as follows: In response to the submarine cable power supply command, a first PWM signal and a second PWM signal are generated; The DC-DC converter circuit and the resonant transformer rectifier circuit are driven according to the first PWM signal and the second PWM signal respectively.
2. The power converter according to claim 1, characterized in that, Also includes: The circuit includes a medium-voltage detection circuit and a high-voltage detection circuit. The medium-voltage detection circuit is connected to the output terminal of the DC-DC converter circuit and the control circuit. The high-voltage detection circuit is connected to the output terminal of the resonant transformer rectifier circuit and the control circuit. The control circuit is also configured to: The voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit are acquired in real time. The first PWM signal is adjusted according to the voltage and current at the output terminal of the DC-DC converter circuit, and the second PWM signal is adjusted according to the voltage and current at the output terminal of the resonant transformer rectifier circuit.
3. The power converter according to claim 2, characterized in that, The step of adjusting the first PWM signal based on the voltage and current at the output terminal of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output terminal of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the resonant transformer rectifier circuit.
4. The power converter according to claim 1, characterized in that: The DC-DC converter circuit is a BUCK-BOOST DC-DC converter circuit.
5. The power converter according to claim 1, characterized in that: The resonant transformer rectifier circuit includes multiple resonant transformer rectifier sub-circuits connected in series. Each resonant transformer rectifier sub-circuit includes a resonant transformer circuit, an isolation transformer circuit, and a rectifier circuit connected in sequence.
6. The power converter according to claim 5, characterized in that: The resonant converter circuit is an LLC resonant converter circuit.
7. A power conversion method, using the power converter of claim 1, characterized in that, Includes the following steps: In response to the submarine cable power supply command, a first PWM signal and a second PWM signal are generated; The DC-DC converter circuit and the resonant transformer rectifier circuit are driven by the first PWM signal and the second PWM signal.
8. The power conversion method according to claim 7, characterized in that, After driving the DC-DC converter circuit and the resonant transformer rectifier circuit according to the first PWM signal and the second PWM signal respectively, the following steps are included: Real-time acquisition of the voltage and current at the output terminal of the DC-DC converter circuit detected by the medium-voltage detection circuit, and the voltage and current at the output terminal of the resonant transformer rectifier circuit detected by the high-voltage detection circuit; The first PWM signal is adjusted according to the voltage and current at the output of the DC-DC converter circuit, and the second PWM signal is adjusted according to the voltage and current at the output of the resonant transformer rectifier circuit.
9. The power conversion method according to claim 8, characterized in that, The step of adjusting the first PWM signal based on the voltage and current at the output of the DC-DC converter circuit, and adjusting the second PWM signal based on the voltage and current at the output of the resonant transformer rectifier circuit, includes: The first PWM signal is adjusted using PID voltage and current closed-loop control based on the voltage and current at the output of the DC-DC converter circuit. The second PWM signal is adjusted using PID voltage and current closed-loop control based on the output voltage and current of the resonant transformer rectifier circuit.
10. A shore-based power supply device, characterized in that, Includes multiple power converters as described in claim 1.