Multi-port interconnection system, operation method and device and nonvolatile storage medium

Abstract

The invention discloses a multi-port interconnection system, an operation method and device and a nonvolatile storage medium. The system comprises a plurality of alternating-current and direct-current converters, a direct-current transformer, an alternating-current power distribution area, a direct-current power distribution area, a first direct-current bus and a second direct-current bus, the alternating-current power distribution area comprises a plurality of alternating-current lines, and the alternating-current lines are connected with the first direct-current bus through the alternating-current and direct-current converters respectively; the direct-current transformer is connected with the first direct-current bus and the second direct-current bus; the DC power distribution area is connected with the second DC bus. The technical problem that an alternating current power grid and a direct current power grid in an existing power distribution system are lack of flexibility and reliability when facing source load access, fault isolation and power mutual aid requirements of different voltage levels is solved.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a multi-port interconnection system, an operation method, a device and a non-volatile storage medium. Background Art

[0002] With the development of new energy power generation, power electronics technology, microelectronics technology, energy storage technology, power market technology, Internet technology, etc., more and more equipment in the power generation, transmission, transformation, distribution, and power consumption of the power system adopts power electronic converters as the control core, and the system integration, intelligence, and networking are becoming stronger and stronger. Multi-port interconnected systems from local to global, from control to scheduling, from hierarchy to coordination have become the development trend of the power system.

[0003] At present, the voltage regulation and energy conversion of DC and AC in multi-port AC / DC hybrid power grids usually adopt two independent systems, which increases the control complexity and requires multiple controllers. In addition, the two independent systems influence each other and cannot achieve automatic control at the same time. As a result, the AC and DC grids in the current distribution system lack flexibility and reliability when facing the needs of source and load access, fault isolation and power mutual assistance at different voltage levels.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present invention provide a multi-port interconnection system, an operation method, a device and a non-volatile storage medium to at least solve the technical problem that the AC power grid and the DC power grid in the current power distribution system lack flexibility and reliability when facing the needs of source-load access, fault isolation and power mutual assistance of different voltage levels.

[0006] According to one aspect of an embodiment of the present invention, a multi-port interconnection system is provided, comprising: a plurality of AC / DC converters, a DC transformer, an AC power distribution area, a DC power distribution area, a first DC bus and a second DC bus, wherein the AC power distribution area comprises a plurality of AC lines, and the plurality of AC lines are respectively connected to the first DC bus through a plurality of AC / DC converters; the DC transformer is connected to the first DC bus and the second DC bus; and the DC power distribution area is connected to the second DC bus.

[0007] Optionally, the system further includes: a DC circuit breaker and multiple AC circuit breakers, wherein the DC circuit breaker is arranged between the DC transformer and the second DC bus; and the multiple AC circuit breakers correspond one-to-one to the multiple AC / DC converters and are arranged between the corresponding AC / DC converters and the first DC bus.

[0008] According to another aspect of an embodiment of the present invention, there is also provided a method for operating a multi-port interconnection system, which is applied to any of the above-mentioned multi-port interconnection systems, and includes: detecting the operating state of the multi-port interconnection system; and adjusting the operating modes of multiple AC / DC converters and DC transformers based on the operating state.

[0009] Optionally, in a case where the multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, the operating modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: when the operating status is normal, controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0010] Optionally, in the case where multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, the operating modes of multiple AC / DC converters and DC transformers are adjusted, including: when the first AC / DC converter is abnormal, the first AC / DC converter is controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode; and / or, when the second AC / DC converter is abnormal, the second AC / DC converter is controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode; and / or, when the third AC / DC converter is abnormal, the three AC / DC converters are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the second AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode.

[0011] Optionally, in a case where the multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, the operating modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: in the case of an abnormality in the DC transformer, controlling the DC transformer to stop operating; controlling the first AC / DC converter to adopt a constant DC voltage control mode, and controlling the remaining AC / DC converters to adopt a constant power control mode.

[0012] Optionally, in the case where the multiple AC / DC converters are three AC / DC converters, the operating modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: when two AC / DC converters among the multiple AC / DC converters are abnormal, controlling the abnormal AC / DC converters to stop running; controlling the AC / DC converters among the multiple AC / DC converters except the abnormal AC / DC converters to adopt a fixed DC voltage control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0013] Optionally, in the case where multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, the working modes of the multiple AC / DC converters and DC transformers are adjusted based on the operating status, including: when the first AC / DC converter and the DC transformer are abnormal, the first AC / DC converter and the DC transformer are controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the second AC / DC converter and the DC transformer are abnormal, the second AC / DC converter and the DC transformer are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the third AC / DC converter and the DC transformer are abnormal, the third AC / DC converter and the DC transformer are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the second AC / DC converter adopts a constant power control mode.

[0014] According to another aspect of an embodiment of the present invention, there is also provided an operating device for a multi-port interconnection system, comprising: a detection module for detecting the operating state of the multi-port interconnection system; and an adjustment module for adjusting the operating modes of multiple AC / DC converters and DC transformers based on the operating state.

[0015] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, the non-volatile storage medium including a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute any one of the above-mentioned methods for operating a multi-port interconnection system.

[0016] According to another aspect of the embodiments of the present invention, a computer device is provided. The computer device includes a processor, and the processor is used to run a program. When the program is run, any one of the above-mentioned methods for operating a multi-port interconnection system is executed.

[0017] According to another aspect of the embodiments of the present invention, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, any one of the above-mentioned operating methods of the multi-port interconnection system is implemented.

[0018] In an embodiment of the present invention, a multi-port interconnection system is adopted, and the system includes: multiple AC / DC converters, DC transformers, AC power distribution areas, DC power distribution areas, a first DC bus and a second DC bus, wherein the AC power distribution area includes multiple AC lines, and the multiple AC lines are respectively connected to the first DC bus through multiple AC / DC converters; the DC transformer is connected to the first DC bus and the second DC bus; and the DC power distribution area is connected to the second DC bus. By detecting the operating status of the multi-port interconnection system; adjusting the working modes of multiple AC / DC converters and DC transformers based on the operating status, the purpose of setting multiple ports to access loads of multiple voltage levels is achieved, thereby achieving the technical effect of improving the flexibility and reliability of the system, and further solving the technical problem of the lack of flexibility and reliability of the AC power grid and the DC power grid in the current power distribution system when facing the source load access, fault isolation and power mutual assistance requirements of different voltage levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A hardware structure block diagram of a computer terminal for implementing an operation method of a multi-port interconnection system is shown;

[0021] Figure 2 is a system architecture diagram of a multi-port interconnection system provided according to an embodiment of the present invention;

[0022] Figure 3 is a flow chart of an operating method of a multi-port interconnection system provided according to an embodiment of the present invention;

[0023] Figure 4 is a control strategy block diagram of a UdcQ mode provided according to an optional embodiment of the present invention;

[0024] Figure 5 is a control strategy block diagram of a PQ mode provided according to an optional embodiment of the present invention;

[0025] Figure 6 It is a structural block diagram of an operating device of a multi-port interconnection system provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] According to an embodiment of the present invention, a method embodiment of a method for operating a multi-port interconnection system is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] The method embodiment provided in the first embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 The hardware structure block diagram of a computer terminal for implementing the operation method of a multi-port interconnection system is shown. Figure 1 As shown, the computer terminal 10 may include one or more (102a, 102b, ..., 102n are used to illustrate) processors (the processor may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0030] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 10. As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0031] The memory 104 can be used to store software programs and modules of application software, such as program instructions / data storage devices corresponding to the operating method of the multi-port interconnection system in the embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, the operating method of the multi-port interconnection system of the above-mentioned application program is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0032] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 .

[0033] Figure 2 is a system architecture diagram of a multi-port interconnection system provided according to an embodiment of the present invention, such as Figure 2 As shown, the system includes: multiple AC / DC converters, a DC transformer, an AC power distribution area, a DC power distribution area, a first DC bus and a second DC bus, wherein the AC power distribution area includes multiple AC lines, and the multiple AC lines are respectively connected to the first DC bus through multiple AC / DC converters; the DC transformer is connected to the first DC bus and the second DC bus; and the DC power distribution area is connected to the second DC bus.

[0034] The multiple AC / DC converters in the system are usually designed as bidirectional power electronic conversion devices, which can convert AC to DC, or convert DC to AC. They connect multiple AC lines in the AC distribution area with the first DC bus to achieve interconnection and power exchange between AC and DC. Among them, the first DC bus can be a medium-voltage DC bus, and the AC / DC converter can adopt different control modes according to system requirements, such as constant power control (PQ mode) or constant DC voltage control (UdcQ mode) to ensure the flexibility and stability of system operation. AC / DC converters can adopt various topological forms of devices according to requirements, such as half-bridge MMC, etc.

[0035] The direct current transformer (DC / DC transformer) is used for voltage conversion and power transmission between direct currents of different voltage levels while providing electrical isolation. It is connected to the first DC bus and the second DC bus, and is responsible for regulating the voltage level from the medium voltage DC bus (for example, the first DC bus connected to the AC distribution area) to the low voltage DC bus (for example, the second DC bus connected to the DC distribution area). The control mode of the DC transformer can include fixed low voltage port side voltage control to ensure the stable operation of various equipment in the power system. The DC / DC transformer can meet the needs of flexible access to sources and loads of various voltage levels such as photovoltaics, charging piles, etc.

[0036] The AC power distribution area contains multiple AC lines, which may be distribution lines from medium voltage to low voltage, responsible for providing AC power to users or loads. The AC-DC converter is connected to the first DC bus, so that the AC power can be converted into DC power to supply power to DC loads or participate in the power mutual assistance of the DC system.

[0037] The DC power distribution area can include DC loads, distributed power sources (such as photovoltaics, energy storage devices) and electric vehicle charging stations, which are directly powered by the second DC bus. The DC power distribution area is directly connected to the second DC bus and receives or transmits power to the first DC bus through a DC transformer.

[0038] The connection between DC buses is achieved through DC transformers, which can effectively manage DC power of different voltage levels and ensure efficient distribution and conversion of power. The design goal of the entire system is to achieve seamless connection between AC and DC power, and improve the flexibility, reliability and energy efficiency of the power system. The system can adjust the control strategy of each device according to the operating mode and power demand. For example, in multi-terminal networking operation, three-terminal networking operation, dual-terminal operation or non-networking operation, the AC / DC converter and DC transformer work together to maintain the stable operation of the system and achieve optimal power distribution. This design is particularly suitable for modern power systems that contain a large amount of renewable energy and DC loads, and can effectively improve the energy absorption capacity and the operating efficiency of the distribution network.

[0039] like Figure 2 As shown, three AC / DC converters are used to exchange energy with the AC system, and one DC transformer is used to solve problems such as low-voltage side energy storage, charging piles, and distributed photovoltaic grid connection.

[0040] The medium-voltage DC bus voltage of the multi-terminal interconnected system is controlled by a constant voltage of the converter at one end, and the remaining converters are backup for each other and can take over the constant voltage control of the medium-voltage DC bus at any time. During normal operation, the output voltage and power of the voltage source converter at each end can be given according to the dispatching instructions, and the power flow distribution of the distribution system can be adjusted in real time to improve the operation efficiency; when a converter at one or both ends stops operating due to a fault, the remaining converters can maintain the normal operation of the system.

[0041] As an optional embodiment, the system also includes: a DC circuit breaker and multiple AC circuit breakers, wherein the DC circuit breaker is arranged between the DC transformer and the second DC bus; and multiple AC circuit breakers correspond one-to-one to multiple AC / DC converters and are arranged between the corresponding AC / DC converters and the first DC bus.

[0042] In the design of the AC / DC multi-port flexible interconnection system, the DC circuit breaker and AC circuit breaker are set to achieve system protection, control and safe operation. They are located at the key nodes of the system and are used to control the on and off of the current in normal operation and fault conditions to ensure the stability of the system and the safety of each component. The DC circuit breaker is set between the DC transformer and the second DC bus. In the system, the DC circuit breaker is mainly responsible for protecting the second DC bus and the DC distribution area connected to it. When the system detects overcurrent, short circuit or other abnormal conditions on the DC side, the DC circuit breaker will quickly disconnect, isolate the faulty part, and prevent the fault current from affecting the entire system, especially on the low-voltage DC side, which helps to protect sensitive DC loads and distributed energy systems, such as electric vehicle charging piles, energy storage systems, and photovoltaic power stations. The AC circuit breaker corresponds to multiple AC / DC converters one by one and is set between the corresponding AC / DC converter and the first DC bus. The AC circuit breaker is used to protect the AC line and AC / DC converter connected to the first DC bus. In the event of a fault, the AC circuit breaker can be disconnected quickly to isolate the faulty AC line or AC / DC converter, preventing the fault from spreading to the AC grid and the first DC bus, and ensuring the normal operation of other parts of the system. In addition, when the system needs maintenance or overhaul, the on-off operation of the AC circuit breaker can be used to safely isolate related equipment and provide work safety.

[0043] The setting and control of circuit breakers are crucial to ensure the stable operation of multi-terminal flexible interconnection systems. In normal operating mode, the circuit breaker is in a closed state, allowing current to flow freely between the AC and DC networks. When a fault occurs, the circuit breaker needs to respond quickly and disconnect the faulty line or equipment to avoid damage to other components in the system. Through sophisticated control strategies, the circuit breaker can automatically adjust its state when the system operation mode changes, such as switching from a four-terminal networking mode to a three-terminal or two-terminal operation mode, to ensure the safe and efficient operation of the power system. The circuit breaker in this configuration not only provides electrical isolation and protection, but also supports flexible reorganization of the system. Even if one or some components fail or require maintenance, the system can be reconfigured by adjusting the state of other circuit breakers to maintain the normal operation of the rest, thereby improving the reliability and availability of the system.

[0044] Figure 3 is a flow chart of an operation method of a multi-port interconnection system according to an embodiment of the present invention. Figure 3 As shown, the method comprises the following steps:

[0045] Step S302, detecting the operating status of the multi-port interconnection system.

[0046] In this step, the operating status of the detection system is to detect the status of each device in the system. High-precision voltage and current sensors can be used to monitor the input and output voltages and currents of each device in the system in real time, including converters, DC transformers, busbars, circuit breakers, etc., to identify abnormal electrical parameters. The temperature of the device can be monitored by built-in or external temperature sensors. Overheating is usually a precursor to equipment failure. For example, the voltage and current of key points in the system are continuously monitored, including the medium-voltage AC bus, the low-voltage AC bus, the medium-voltage DC bus, the low-voltage DC bus, and both ends of each AC / DC converter and DC transformer. By analyzing abnormal changes in voltage and current, faults in the system, such as overvoltage, overcurrent, short circuit, etc., can be detected in time. According to changes in system load conditions, identify devices that need to increase or decrease power.

[0047] Step S304: adjusting the operating modes of the plurality of AC / DC converters and the DC transformer based on the operating status.

[0048] In this step, adjusting the working modes of multiple AC / DC converters and DC transformers based on the operating status is a key strategy to ensure efficient and stable operation of the AC / DC multi-port flexible interconnection system. This process is usually implemented by the system's central control unit or distributed intelligent control mechanism to respond to different operating requirements and fault conditions. The following are some basic principles and steps for adjusting the working mode:

[0049] Determine the control mode of each device based on the real-time needs and operating objectives of the system (such as power balance, voltage stability, fault isolation, etc.). When a fault is detected, quickly analyze the scope of the fault, decide to isolate the faulty device and adjust the working mode of other devices to maintain system stability. There are several control modes for AC / DC converters:

[0050] Constant DC voltage control mode (UdcQ mode): When the system requires a stable DC voltage, the converter is set to UdcQ (constant DC voltage and reactive power) mode, which is responsible for maintaining the DC bus voltage and controlling the reactive power. Figure 4 It is a control strategy block diagram of the UdcQ mode provided according to an optional embodiment of the present invention. The control strategy of the UdcQ mode is used to ensure the stability of the DC bus voltage and the reasonable distribution of the system reactive power. It mainly includes the following key components: DC voltage control (Udc control) is used to ensure that the DC bus voltage is stable near the set value. Usually a voltage source converter (VSC) is responsible for the control of the DC voltage. The DC voltage sensor is used to measure the actual voltage of the DC bus. The PID (proportional-integral-differential) controller or the PI (proportional-integral) controller is used to compare the set DC voltage value with the actual measured value and generate a control signal. Reactive power control (Q control) is used to control the output of the converter reactive power to support the reactive balance of the AC system. Together with the Udc control, the voltage source converter also participates in the regulation of reactive power. The reactive power sensor is used to measure the reactive power actually output by the converter. The PID or PI controller is used to compare the set reactive power value with the actual measured value and generate a corresponding control signal. Current control (id and iq control) is used to adjust the d-axis and q-axis currents output by the converter in response to the instructions generated by the DC voltage and reactive power controllers. A PI controller is usually used for closed-loop control of the current. The abc to dq converter is used to convert the three-phase AC current into the dq coordinate system for comparison with the output signal of the controller. The PWM (pulse width modulation) signal generation is used to generate a PWM signal for driving the converter switching device according to the current control signal to achieve real-time control of the input and output currents. The PWM signal generation module receives the signal output from the current controller and generates a switching signal for controlling the IGBT (insulated gate bipolar transistor) or other power electronic switches in the converter. The feedback signal is used to achieve closed-loop control by feeding back the actual output current and voltage of the converter to ensure the accuracy of the control signal. The current sensor and voltage sensor are used to monitor the output state of the converter in real time. The feedback signal is sent to the controller, compared with the reference signal, and a control error signal is generated for adjusting the control strategy. The filter is used to filter out the high-frequency components in the PWM signal and generate a smooth voltage signal. The filter is integrated in the output circuit of the inverter to improve the quality of the output current and voltage.

[0051] The entire control strategy is based on advanced control technologies of power electronic equipment, such as current closed-loop control, PWM modulation technology, and PI controller in modern control theory, to achieve precise control of DC voltage and reactive power. Figure 4 In the process, starting from the difference between the DC voltage set value and the actual measured value, the DC voltage controller generates a modulation signal, then the reactive power control, and finally the current controller generates a PWM signal. The whole process forms a closed-loop control system to ensure that the system operates stably in the UdcQ mode and provides high-quality electric energy. This control strategy is particularly important in multi-terminal flexible DC interconnection systems because it can effectively respond to dynamic changes in the power grid and ensure the stability and reliability of the system under various operating conditions.

[0052] Fixed power control mode (PQ mode): When flexible power control is required, the converter is adjusted to PQ (fixed active and reactive power) mode, and the power output is dynamically adjusted according to system scheduling instructions or load requirements to achieve flexible power regulation. Figure 5 is a control strategy block diagram of the PQ mode provided according to an optional embodiment of the present invention, such as Figure 5 As shown, PQ mode refers to the active power (P) and reactive power (Q) control mode. In this mode, the converter is set to simultaneously control the output active power and reactive power to meet the system scheduling requirements or achieve optimal power distribution. Figure 5Key components of the PQ mode control strategy: Active power control (P control) is used to ensure that the active power output of the converter matches the set reference value to achieve accurate energy distribution and control. It is usually a power electronic switch device in the converter, using a PI (proportional-integral) controller, which receives the set active power reference value and the actual measured active power value, and generates an active power control signal through comparison and integration. Reactive power control (Q control) is used to control the reactive power output of the converter to maintain the voltage level of the AC system and improve the efficiency of power transmission. It also uses a PI controller, which compares the set reactive power reference value and the actual measured reactive power value to generate a reactive power control signal. The current control in the dq coordinate system is used to adjust the current (id and iq) of the converter in the dq coordinate system based on the instructions generated by the P control and Q control to achieve accurate control of active and reactive power. The current control on each coordinate axis uses an independent PI controller to process the instructions related to active power and reactive power control and generate current regulation signals. The inverse transformation to the control signal in the abc coordinate system is used to convert the control signal in the dq coordinate system into a signal in the three-phase AC coordinate system (abc) to drive the three-phase power electronic switch. Using the dq to abc coordinate transformation algorithm, the modulated current control signal is converted into an abc coordinate system signal suitable for driving the converter. The PWM signal generates a PWM (pulse width modulation) signal for controlling the power electronic switch to realize the conversion between the control signal and the actual switching action. The PWM modulation module receives the control signal in the abc coordinate system and generates an appropriate PWM signal for controlling the IGBT (insulated gate bipolar transistor) or other power electronic switch in the converter. The feedback signal is used to feed back the actual output active power, reactive power and current to the controller to realize closed-loop control and ensure the stability and accuracy of the system operation. The power and current sensors are used to measure the active power, reactive power and current respectively and provide feedback signals.

[0053] The entire control strategy requires close coordination between the P control module and the Q control module, as well as interaction with the current control module and the PWM signal generation module to achieve precise control of the converter and dynamic regulation of the system power. In PQ mode, the converter can dynamically adjust its output active power and reactive power according to system dispatch instructions or real-time power demand, thereby achieving flexible control of the system power. This control mode is particularly suitable for scenarios that require precise power regulation, such as optimizing power distribution in a multi-port system or responding to the fluctuating power input of new energy. The system can effectively respond to various power demands and ensure the stability and efficiency of power transmission.

[0054] Statcom mode: When a converter at one end cannot be connected to the AC or DC network, or the system requires additional reactive power support, the converter can be switched to Statcom mode to provide reactive power compensation.

[0055] There are several control modes for DC transformers:

[0056] Fixed low-voltage port side voltage control: According to the needs of the low-voltage side equipment (such as charging piles, energy storage systems, distributed photovoltaics, etc.), adjust the output voltage of the DC transformer to ensure the stable operation of these devices.

[0057] Power conversion control: When the system power demand changes, adjust the power conversion capacity of the DC transformer to adapt to the power requirements of different equipment and achieve power mutual assistance between medium and low voltage DC distribution areas.

[0058] The central control unit or intelligent control mechanism sends the adjusted working mode as a control signal to each AC / DC converter and DC transformer. The equipment adjusts its operating parameters according to the received control signal and enters the specified working mode. The adjusted equipment status and system operation data are fed back to the control center for verification of the adjustment effect and further decision-making. The system continuously monitors the adjusted operating status to respond to subsequent load changes or fault conditions. According to the new operating status, the system automatically or by the operator adjusts the control strategy to optimize the equipment working mode to ensure that the system still operates stably under changing conditions.

[0059] Through the above process, the AC / DC multi-port flexible interconnection system can flexibly respond to various operating conditions, whether it is fluctuations in power demand, isolation of equipment failures, or changes in system topology, and can maintain system stability and power supply quality by adjusting the operating modes of converters and DC transformers in real time, thereby improving the overall performance and reliability of the system. This dynamic adjustment strategy based on operating conditions is a key component of modern smart grids and new power systems, and helps to achieve efficient use of energy and stable operation of the power grid.

[0060] Through the above steps, the purpose of setting up multiple ports to access loads of various voltage levels is achieved, thereby achieving the technical effect of improving the flexibility and reliability of the system, and further solving the technical problem of lack of flexibility and reliability of AC power grid and DC power grid in the current distribution system when facing the needs of source load access, fault isolation and power mutual assistance of different voltage levels.

[0061] As an optional embodiment, in the case where multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, the operating modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: when the operating status is normal, controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0062] Optionally, when all devices in the system are normal, the system supplies power to the DC distribution network through multiple AC and DC and realizes flexible power transfer. The DC transformer adopts constant DC voltage control to provide a stable low-voltage grid-connected interface for energy storage, loads and distributed photovoltaics on the low-voltage side. In this operating mode, the first AC / DC converter in the system (designated as VSC1) adopts constant DC voltage control (UdcQ mode), and the other two ends, namely the second AC / DC converter and the third AC / DC converter (VSC2, VSC3), adopt constant power control (PQ mode). For the DC transformer connecting the DC load and the distributed power source with a DC interface, a constant low-voltage port side voltage control is adopted to ensure the stable operation of each device.

[0063] As an optional embodiment, in the case where multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, the operating modes of multiple AC / DC converters and DC transformers are adjusted, including: when the first AC / DC converter is abnormal, the first AC / DC converter is controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode; and / or, when the second AC / DC converter is abnormal, the second AC / DC converter is controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode; and / or, when the third AC / DC converter is abnormal, the three AC / DC converters are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the second AC / DC converter adopts a constant power control mode, and the DC transformer adopts a fixed low-voltage port side voltage control mode.

[0064] Optionally, when one end fails or is out of network operation due to maintenance, the system enters the three-terminal network operation mode. In this operation mode, both the AC circuit breaker and the DC circuit breaker are in the open state to isolate the exit station. One end of the system (VSC1 is preferred, and VSC2 is used if VSC1 is out of operation) adopts constant DC voltage control (UdcQ mode), and the other end adopts constant power control (PQ mode). For the DC transformer connecting the DC load and the distributed power source with a DC interface, the low-voltage port side voltage control is adopted to ensure the stable operation of each device.

[0065] As an optional embodiment, in the case where multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, respectively, the operating modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: in the case of an abnormality in the DC transformer, controlling the DC transformer to stop operating; controlling the first AC / DC converter to adopt a constant DC voltage control mode, and controlling the remaining AC / DC converters to adopt a constant power control mode.

[0066] Optionally, when the DC transformer fails or is taken out of network operation due to maintenance, the first AC / DC converter in the system (designated as VSC1) adopts constant DC voltage control (UdcQ mode), and the other two ends, namely the second AC / DC converter and the third AC / DC converter (VSC2, VSC3), adopt constant power control (PQ mode).

[0067] As an optional embodiment, in the case where the multiple AC / DC converters are three AC / DC converters, the working modes of the multiple AC / DC converters and the DC transformer are adjusted based on the operating status, including: when two AC / DC converters among the multiple AC / DC converters are abnormal, controlling the abnormal AC / DC converters to stop running; controlling the AC / DC converters among the multiple AC / DC converters except the abnormal AC / DC converters to adopt a fixed DC voltage control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0068] Optionally, two of the three-terminal AC / DC converters and DCTs (DC transformers) connected to the AC grid in the entire AC / DC hybrid distribution network are out of operation, and the system is interconnected by the remaining two-terminal devices through DC cables, thus forming a double-terminal operation mode. If both of the two devices out of operation are AC / DC converters, that is, the double-terminal system is an AC / DC converter and a DC transformer, the remaining AC / DC converters adopt the UdcQ mode, and the DCT operates in a fixed low-voltage side DC voltage control mode.

[0069] As an optional embodiment, in the case where multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, the operating modes of the multiple AC / DC converters and DC transformers are adjusted, including: when the first AC / DC converter and the DC transformer are abnormal, the first AC / DC converter and the DC transformer are controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the second AC / DC converter and the DC transformer are abnormal, the second AC / DC converter and the DC transformer are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the third AC / DC converter and the DC transformer are abnormal, the third AC / DC converter and the DC transformer are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the second AC / DC converter adopts a constant power control mode.

[0070] Optionally, when the three-terminal AC / DC converter and the DCT (DC transformer) connected to the AC power grid in the entire AC / DC hybrid distribution network and one AC / DC converter are out of operation, both ends of the double-end interconnected system are AC / DC converters, then VSC1 is preferably selected as UdcQ mode, and if VSC1 is not connected to the grid, VSC2 is selected as UdcQ mode, and the other station works in PQ mode.

[0071] Specifically, Table 1 is a table showing the system operation mode division and main equipment operation status. As shown in Table 1, the system operation mode division and main equipment operation status are shown, where VSC1, VSC2, and VSC3 are three AC / DC converters, and DCT is a DC transformer.

[0072]

[0073] Table 1 System operation mode division and main equipment operation status table

[0074] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0075] Through the description of the above implementation methods, those skilled in the art can clearly understand that the operation method of the multi-port interconnection system according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0076] According to an embodiment of the present invention, there is also provided an operating device of a multi-port interconnection system for implementing the operating method of the multi-port interconnection system. Figure 6 is a structural block diagram of an operating device of a multi-port interconnection system provided according to an embodiment of the present invention, such as Figure 6 As shown, the operating device of the multi-port interconnection system includes: a detection module 62 and an adjustment module 64. The operating device of the multi-port interconnection system is described below.

[0077] The detection module 62 is used to detect the operating status of the multi-port interconnection system.

[0078] The adjustment module 64 is connected to the detection module 62 and is used to adjust the working modes of the multiple AC / DC converters and the DC transformer based on the operating status.

[0079] It should be noted that the detection module 62 and the adjustment module 64 correspond to steps S302 to S304 in the embodiment, and the examples and application scenarios implemented by the multiple modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the above modules, as part of the device, can be run in the computer terminal 10 provided in the embodiment.

[0080] An embodiment of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one network device among multiple network devices of a computer network. The computer device includes a memory and a processor.

[0081] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the operating method and device of the multi-port interconnection system in the embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, realizing the operating method of the multi-port interconnection system mentioned above. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0082] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: detecting the operating status of the multi-port interconnection system; and adjusting the operating modes of multiple AC / DC converters and DC transformers based on the operating status.

[0083] Optionally, the processor may also execute program code of the following steps: when the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: when the operating status is normal, controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0084] Optionally, the processor may also execute program code of the following steps: in a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter respectively, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: when the first AC / DC converter is abnormal, controlling the first AC / DC converter to stop running, the second AC / DC converter to adopt a constant DC voltage control mode, the third AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a fixed low-voltage port side voltage control mode; and / or, when the second AC / DC converter is abnormal, controlling the second AC / DC converter to stop running, the first AC / DC converter to adopt a constant DC voltage control mode, the third AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a fixed low-voltage port side voltage control mode; and / or, when the third AC / DC converter is abnormal, controlling the three AC / DC converters to stop running, the first AC / DC converter to adopt a constant DC voltage control mode, the second AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0085] Optionally, the processor may also execute program code of the following steps: when the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: when the DC transformer is abnormal, controlling the DC transformer to stop operating; controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode.

[0086] Optionally, the processor may also execute program code of the following steps: in the case where the multiple AC / DC converters are three AC / DC converters, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: in the case where two AC / DC converters among the multiple AC / DC converters are abnormal, controlling the abnormal AC / DC converters to stop running; controlling the AC / DC converters among the multiple AC / DC converters except the abnormal AC / DC converters to adopt a fixed DC voltage control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0087] Optionally, the processor may also execute program code of the following steps: in a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter respectively, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and DC transformers, including: when the first AC / DC converter and the DC transformer are abnormal, controlling the first AC / DC converter and the DC transformer to stop running, the second AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the second AC / DC converter and the DC transformer are abnormal, controlling the second AC / DC converter and the DC transformer to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, when the third AC / DC converter and the DC transformer are abnormal, controlling the third AC / DC converter and the DC transformer to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the second AC / DC converter adopts a constant power control mode.

[0088] According to an embodiment of the present invention, a multi-port interconnection system is provided, which includes: multiple AC / DC converters, DC transformers, AC power distribution areas, DC power distribution areas, a first DC bus and a second DC bus, wherein the AC power distribution area includes multiple AC lines, and the multiple AC lines are respectively connected to the first DC bus through multiple AC / DC converters; the DC transformer is connected to the first DC bus and the second DC bus; and the DC power distribution area is connected to the second DC bus. By detecting the operating status of the multi-port interconnection system and adjusting the working modes of multiple AC / DC converters and DC transformers based on the operating status, the purpose of setting multiple ports to access loads of multiple voltage levels is achieved, thereby achieving the technical effect of improving the flexibility and reliability of the system, and further solving the technical problem of the lack of flexibility and reliability of the AC power grid and the DC power grid in the current power distribution system when facing the requirements of source-load access, fault isolation and power mutual assistance of different voltage levels.

[0089] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a non-volatile storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0090] The embodiment of the present invention further provides a non-volatile storage medium. Optionally, in this embodiment, the non-volatile storage medium can be used to store the program code executed by the operation method of the multi-port interconnection system provided by the above embodiment.

[0091] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0092] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: detecting an operating state of the multi-port interconnection system; and adjusting operating modes of multiple AC / DC converters and DC transformers based on the operating state.

[0093] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: when the multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: when the operating status is normal, controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0094] Optionally, in this embodiment, the non-volatile storage medium is configured to store a program code for executing the following steps: in a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter, and a third AC / DC converter, respectively, adjusting the operating modes of the multiple AC / DC converters and the DC transformer based on the operating status, including: in a case where the first AC / DC converter is abnormal, controlling the first AC / DC converter to stop operating, the second AC / DC converter to adopt a constant DC voltage control mode, the third AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a constant low voltage control mode. Port side voltage control mode; and / or, in the event of an abnormality in the second AC / DC converter, controlling the second AC / DC converter to stop running, the first AC / DC converter to adopt a constant DC voltage control mode, the third AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a constant low-voltage port side voltage control mode; and / or, in the event of an abnormality in the third AC / DC converter, controlling the three AC / DC converters to stop running, the first AC / DC converter to adopt a constant DC voltage control mode, the second AC / DC converter to adopt a constant power control mode, and the DC transformer to adopt a constant low-voltage port side voltage control mode.

[0095] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: when the multiple AC / DC converters respectively include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: in the event of an abnormality in the DC transformer, controlling the DC transformer to stop operating; controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode.

[0096] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: in a case where the multiple AC / DC converters are three AC / DC converters, based on the operating status, adjusting the operating modes of the multiple AC / DC converters and the DC transformer, including: in a case where two AC / DC converters among the multiple AC / DC converters are abnormal, controlling the abnormal AC / DC converters to stop running; controlling the AC / DC converters among the multiple AC / DC converters except the abnormal AC / DC converters to adopt a fixed DC voltage control mode; controlling the DC transformer to adopt a fixed low-voltage port side voltage control mode.

[0097] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: in a case where multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter and a third AC / DC converter, respectively, based on the operating status, adjusting the operating modes of multiple AC / DC converters and DC transformers, including: in the case where the first AC / DC converter and the DC transformer are abnormal, controlling the first AC / DC converter and the DC transformer to stop running, the second AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, in the case where the second AC / DC converter and the DC transformer are abnormal, controlling the second AC / DC converter and the DC transformer to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, in the case where the third AC / DC converter and the DC transformer are abnormal, controlling the third AC / DC converter and the DC transformer to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the second AC / DC converter adopts a constant power control mode.

[0098] An embodiment of the present invention further provides a computer program product, including a computer program. Optionally, in this embodiment, when the computer program is executed by a processor, it can achieve: detecting the operating status of the multi-port interconnection system; and adjusting the operating modes of multiple AC / DC converters and DC transformers based on the operating status.

[0099] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0100] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0101] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0102] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0103] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-port interconnection system, characterized in that: include: A plurality of AC / DC converters, a DC transformer, an AC power distribution area, a DC power distribution area, a first DC bus and a second DC bus, wherein: The AC power distribution area includes a plurality of AC lines, and the plurality of AC lines are respectively connected to the first DC bus through the plurality of AC / DC converters; The DC transformer is connected to the first DC bus and the second DC bus; The DC power distribution area is connected to the second DC bus.

2. The system according to claim 1, characterized in that Also includes: A DC circuit breaker and a plurality of AC circuit breakers, wherein: The DC circuit breaker is arranged between the DC transformer and the second DC bus; The multiple AC circuit breakers correspond one-to-one to the multiple AC / DC converters and are arranged between the corresponding AC / DC converters and the first DC bus.

3. A method for operating a multi-port interconnection system, characterized in that: A multi-port interconnection system as applied to any one of claims 1 to 2 above, comprising: Detect the operating status of the multi-port interconnection system; Based on the operating status, the operating modes of the plurality of AC / DC converters and the DC transformer are adjusted.

4. The method according to claim 3, characterized in that In a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter, and a third AC / DC converter, respectively, adjusting the working modes of the multiple AC / DC converters and the DC transformer based on the operating state includes: When the operating state is normal, controlling the first AC / DC converter to adopt a constant DC voltage control mode, and the remaining AC / DC converters to adopt a constant power control mode; The DC transformer is controlled to adopt a fixed low voltage port side voltage control mode.

5. The method according to claim 3, characterized in that: In a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter, and a third AC / DC converter, respectively, adjusting the working modes of the multiple AC / DC converters and the DC transformer based on the operating state includes: In the case of an abnormality in the first AC / DC converter, the first AC / DC converter is controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a constant low-voltage port side voltage control mode; and / or, in the event of an abnormality in the second AC / DC converter, controlling the second AC / DC converter to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the third AC / DC converter adopts a constant power control mode, and the DC transformer adopts a constant low-voltage port side voltage control mode; And / or, in the event of an abnormality in the third AC / DC converter, the three AC / DC converters are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, the second AC / DC converter adopts a constant power control mode, and the DC transformer adopts a constant low-voltage port side voltage control mode.

6. The method according to claim 3, characterized in that In a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter, and a third AC / DC converter, respectively, adjusting the working modes of the multiple AC / DC converters and the DC transformer based on the operating state includes: When the DC transformer is abnormal, controlling the DC transformer to stop running; The first AC / DC converter is controlled to adopt a constant DC voltage control mode, and the remaining AC / DC converters are controlled to adopt a constant power control mode.

7. The method according to claim 3, characterized in that In the case where the plurality of AC / DC converters are three AC / DC converters, adjusting the working modes of the plurality of AC / DC converters and the DC transformer based on the operating state includes: When two AC / DC converters among the plurality of AC / DC converters are abnormal, controlling the abnormal AC / DC converters to stop running; Controlling the AC / DC converters among the plurality of AC / DC converters except the abnormal AC / DC converter to adopt a constant DC voltage control mode; The DC transformer is controlled to adopt a fixed low voltage port side voltage control mode.

8. The method according to claim 3, characterized in that In a case where the multiple AC / DC converters include a first AC / DC converter, a second AC / DC converter, and a third AC / DC converter, respectively, adjusting the working modes of the multiple AC / DC converters and the DC transformer based on the operating state includes: In the case that the first AC / DC converter and the DC transformer are abnormal, the first AC / DC converter and the DC transformer are controlled to stop running, the second AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; and / or, in the event of an abnormality in the second AC / DC converter and the DC transformer, controlling the second AC / DC converter and the DC transformer to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the third AC / DC converter adopts a constant power control mode; And / or, in the event of an abnormality in the third AC / DC converter and the DC transformer, the third AC / DC converter and the DC transformer are controlled to stop running, the first AC / DC converter adopts a constant DC voltage control mode, and the second AC / DC converter adopts a constant power control mode.

9. An operating device for a multi-port interconnection system, characterized in that: include: A detection module, used for detecting the operation status of the multi-port interconnection system; The adjustment module is used to adjust the working modes of multiple AC / DC converters and DC transformers based on the operating status.

10. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored program, wherein when the program is executed, the device where the non-volatile storage medium is located is controlled to execute the operating method of the multi-port interconnection system according to any one of claims 3 to 8.

11. A computer device, characterized in that: include: Memory and processor, The memory stores a computer program; The processor is used to execute the computer program stored in the memory, and when the computer program is run, the processor executes the operating method of the multi-port interconnection system according to any one of claims 3 to 8.

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the operating method of the multi-port interconnection system described in any one of claims 3 to 8 is implemented.

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