AC / DC energy exchange system control method and device suitable for multiple scenes

Abstract

The invention relates to an AC / DC energy exchange system control method and device suitable for multiple scenes, and the method comprises the steps: setting a control strategy of a power electronic device adopted by an energy exchanger in an AC / DC energy exchange system; setting a coordination control strategy of an interface of an energy exchanger in the AC / DC energy exchange system; determining a starting control strategy of an energy exchanger in the AC / DC energy exchange system, and pre-charging a direct current side of a grid-connected converter to a set value by adopting the starting control strategy so as to start the energy exchanger in the AC / DC energy exchange system, and realizing power mutual assistance and system power balance control in various operation modes under the control of the control strategy and the coordination control strategy. According to the invention, power mutual assistance and system power balance control in various operation modes can be realized, and high flexibility, stability and reliability are provided for energy management.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a control method and device for an AC / DC energy exchange system suitable for multiple scenarios. Background Art

[0002] Traditional distribution networks mainly rely on centralized power plants to provide electricity, and transmit electricity to various places through high-voltage transmission lines. Although this method was able to effectively meet demand in the past, with the rapid development of distributed energy (such as wind power, photovoltaics, etc.) and the widespread access to new loads such as electric vehicles, the challenges faced by traditional distribution networks are increasing. Distributed energy generation has significant intermittent and random characteristics, making the supply and demand balance of the power grid more complicated. The open-loop operation mode of the traditional distribution network cannot quickly respond to the dynamic changes of distributed energy and loads, and it is difficult to achieve efficient distribution and real-time scheduling of electricity. With the extensive use of power electronic equipment, the power quality problems of the distribution network (such as voltage fluctuations, harmonics, etc.) have become more prominent. At the same time, the vulnerability of the power grid in emergencies (such as natural disasters) has become more obvious.

[0003] In order to meet the above challenges, AC / DC hybrid distribution system came into being. This system introduces DC distribution technology into the traditional AC distribution network, combines the advantages of both, and builds a flexible and efficient power distribution network. Its main advantages include reducing the power conversion links, fast response capability, and flexible power and voltage control. DC distribution reduces the number of AC-DC conversions and reduces energy loss. The application of power electronic devices enables the system to respond quickly to changes in load and distributed energy, improving power quality and system stability. The AC / DC hybrid system can achieve precise power and voltage regulation and adapt to changing power demand and supply.

[0004] In the AC / DC hybrid power distribution system, the energy exchange device is a key component. It realizes energy conversion and distribution in multiple ports, multiple voltage levels and AC / DC forms, and has functions such as bidirectional energy flow, flexible power flow regulation, harmonic and reactive power control, and port fault isolation. The energy exchange device connects the ports through a common DC bus to realize flexible energy exchange and distribution. Its topological structure includes string multi-port, star common DC bus multi-port and star high-frequency coupling multi-port. The converters of different ports (such as VSC converter, Boost converter, Buck converter, DAB converter, etc.) realize effective management of connected distributed energy and loads through precise control strategies. The energy management platform determines the power transfer value between devices based on the optimization algorithm to achieve maximum social welfare. This control strategy takes into account the different needs of power sources and loads after the marketization of electricity, and ensures the economy and stability of the system. The research on the optimization control strategy aims to achieve coordinated optimization management of distributed energy, energy storage equipment and loads in the distribution network through mathematical modeling and algorithm design. The main research contents include linearization methods for model optimization, operation cost models and simulation verification, which ensure the efficient and stable operation of the distribution network. The optimization control strategy of the emergency power supply system of the distribution network is of great significance in ensuring the stability of the power system, improving energy efficiency and responding to emergencies. However, most of the existing control strategies can only meet a single operation mode, lacking the design of power mutual assistance and system power balance control under different operation modes. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an AC / DC energy exchange system control method and device suitable for multiple scenarios, which can realize power mutual assistance and system power balance control in various operating modes, and provide high flexibility, stability and reliability for energy management.

[0006] The technical solution adopted by the present invention to solve the technical problem is: to provide an AC / DC energy exchange system control method applicable to multiple scenarios, comprising the following steps:

[0007] Setting a control strategy for a power electronic device used in an energy exchanger in the AC / DC energy exchange system;

[0008] Setting a coordinated control strategy for interfaces of energy exchangers in the AC / DC energy exchange system;

[0009] Determine the startup control strategy of the energy exchanger in the AC / DC energy exchange system, and use the startup control strategy to pre-charge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system, and realize power mutual assistance and system power balance control in various operating modes under the control of the control strategy and coordinated control strategy.

[0010] The power electronic device used in the energy exchanger in the AC / DC energy exchange system includes a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, an energy storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter and an internal dual active bridge converter of the energy exchanger.

[0011] The control strategy of setting the power electronic device used by the energy exchanger in the AC / DC energy exchange system specifically includes:

[0012] The control strategy of the distribution network interface voltage source converter is set as: constant DC voltage and constant reactive power control;

[0013] The control strategy of the AC load port voltage source converter is set as follows: adjusting the grid frequency on the load side to a nominal value, and maintaining the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system;

[0014] The control strategy of the photovoltaic power generation port boost converter is set as follows: using the maximum power point tracking mode to adjust the operating voltage to maximize the output; when the load demand is exceeded, switching to the constant voltage mode to limit the output, and stabilizing the output voltage according to the DC bus voltage through PI control and PWM control;

[0015] The control strategy of the bidirectional buck-boost converter of the energy storage port is set as follows: in the grid-connected mode, it works in the constant power mode; in the island mode or during a fault, it works in the constant voltage mode;

[0016] The control strategy of the DC load port buck converter is set to: constant voltage control;

[0017] The control strategies of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy switch are set to: constant voltage control, and power transmission is adjusted by adjusting the phase shift angle.

[0018] The coordinated control strategy for setting the interface of the energy exchanger in the AC / DC energy exchange system specifically includes:

[0019] The coordinated control strategy of the distribution network interface of the energy exchanger in the AC / DC energy exchange system is set to: fixed active power control and fixed reactive power control;

[0020] The coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system is set to: fixed frequency control and fixed Usm control;

[0021] The coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system is set as follows: fixed low-voltage side DC voltage control;

[0022] The coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system is set as follows: fixed active power control;

[0023] The coordinated control strategy of the energy storage port of the energy exchanger in the AC / DC energy exchange system is set as: fixed active power control;

[0024] The coordinated control strategy of the interconnection interface of the switch in the AC / DC energy exchange system is set as: fixed active power control;

[0025] The coordinated control strategy of the interface between the DC side bus of the grid-connected converter inside the energy exchanger of the AC / DC energy exchange system and the common DC bus is set as follows: fixed converter side DC voltage control;

[0026] The coordinated control strategy of the interface between the common DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system is set as follows: DC bus voltage control at the multi-energy DC interface is set;

[0027] The coordinated control strategy of the internal energy storage device interface of the energy exchanger in the AC / DC energy exchange system is set as: fixed common DC bus voltage control.

[0028] The startup control strategy of the energy exchanger in the AC / DC energy exchange system includes:

[0029] Disconnect the switch between the DC side busbar of the grid-connected converter and the rest of the parts, and only connect the grid-connected converter to the AC distribution network; lock all control and switch tubes, use the anti-parallel diode of the energy exchanger as a three-phase uncontrolled rectifier, and uncontrollably charge the DC side capacitor of the energy exchanger;

[0030] Setting the grid-connected converter to a power-quality mode to control the charging of the DC link capacitor to a DC voltage control value;

[0031] Close the switch between the DC side bus of the grid-connected converter and the rest, turn on all controls of the energy exchanger, and complete the startup of the energy exchanger.

[0032] The technical solution adopted by the present invention to solve the technical problem is: to provide an AC / DC energy exchange system control device suitable for multiple scenarios, including:

[0033] A determination module, used to determine a power electronic device used by an energy exchanger in an AC / DC energy exchange system, and use the power electronic device to connect the AC / DC energy exchange system to a power distribution network;

[0034] A first setting module, used to set a control strategy of a power electronic device used by an energy exchanger in the AC / DC energy exchange system;

[0035] A second setting module, used to set a coordinated control strategy of an interface of an energy exchanger in the AC / DC energy exchange system;

[0036] A startup control module is used to determine the startup control strategy of the energy exchanger in the AC / DC energy exchange system, and adopt the startup control strategy to pre-charge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system, and realize power mutual assistance and system power balance control in various operating modes under the control of the control strategy and the coordinated control strategy.

[0037] The power electronic device used in the energy exchanger in the AC / DC energy exchange system includes a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, an energy storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter and an internal dual active bridge converter of the energy exchanger.

[0038] The first setting module includes:

[0039] A first setting unit, configured to set the control strategy of the distribution network interface voltage source converter to: constant DC voltage and constant reactive power control;

[0040] A second setting unit is used to set the control strategy of the AC load port voltage source converter to: adjust the grid frequency on the load side to a nominal value, and maintain the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system;

[0041] A third setting unit is used to set the control strategy of the photovoltaic power generation port boost converter to: use the maximum power point tracking mode to adjust the operating voltage to maximize the output; when the load demand is exceeded, switch to the constant voltage mode to limit the output, and stabilize the output voltage according to the DC bus voltage through PI control and PWM control;

[0042] A fourth setting unit is used to set the control strategy of the bidirectional buck-boost converter of the energy storage port to: operate in a constant power mode in a grid-connected mode; operate in a constant voltage mode in an island mode or during a fault;

[0043] A fifth setting unit, configured to set the control strategy of the DC load port buck converter to: constant voltage control;

[0044] The sixth setting unit is used to set the control strategy of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy exchanger to: constant voltage control, and adjust power transmission by adjusting the phase shift angle.

[0045] The second setting module includes:

[0046] A seventh setting unit, used to set the coordinated control strategy of the power distribution network interface of the energy exchanger in the AC / DC energy exchange system to: fixed active power control and fixed reactive power control;

[0047] An eighth setting unit, used to set the coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system to: fixed frequency control and fixed Usm control;

[0048] A ninth setting unit, used to set the coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system to: set low-voltage side DC voltage control;

[0049] A tenth setting unit is used to set the coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system to: fixed active power control;

[0050] an eleventh setting unit, for setting a coordinated control strategy of an energy storage port of an energy exchanger in the AC / DC energy exchange system to: fixed active power control;

[0051] A twelfth setting unit is used to set the coordinated control strategy of the switch interconnection interface in the AC / DC energy exchange system to: fixed active power control;

[0052] A thirteenth setting unit is used to set the coordinated control strategy of the interface between the DC side bus of the grid-connected converter inside the energy exchanger of the AC / DC energy exchange system and the common DC bus to: set the DC voltage control on the converter side;

[0053] A fourteenth setting unit is used to set the coordinated control strategy of the interface between the common DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system as follows: setting the DC bus voltage control at the multi-energy DC interface;

[0054] The fifteenth setting unit is used to set the coordinated control strategy of the internal energy storage device interface of the energy exchanger in the AC / DC energy exchange system to: set common DC bus voltage control.

[0055] The startup control strategy of the energy exchanger in the AC / DC energy exchange system includes:

[0056] Disconnect the switch between the DC side busbar of the grid-connected converter and the rest of the parts, and only connect the grid-connected converter to the AC distribution network; lock all control and switch tubes, use the anti-parallel diode of the energy exchanger as a three-phase uncontrolled rectifier, and uncontrollably charge the DC side capacitor of the energy exchanger;

[0057] Setting the grid-connected converter to a power-quality mode to control the charging of the DC link capacitor to a DC voltage control value;

[0058] Close the switch between the DC side bus of the grid-connected converter and the rest, turn on all controls of the energy exchanger, and complete the startup of the energy exchanger.

[0059] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the above-mentioned AC / DC energy exchange system control method applicable to multiple scenarios are implemented.

[0060] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned AC / DC energy exchange system control method applicable to multiple scenarios are implemented.

[0061] Beneficial Effects

[0062] Due to the adoption of the above-mentioned technical scheme, the present invention has the following advantages and positive effects compared with the prior art: the present invention designs the power electronic device, startup control strategy, control strategy of the power electronic device and coordinated control strategy of the interface adopted by the energy exchanger, realizes power mutual assistance and system power balance control in various operating modes, and provides a high degree of flexibility, stability and reliability for energy management. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a flow chart of a control method of an AC / DC energy exchange system applicable to multiple scenarios according to a first embodiment of the present invention;

[0064] Figure 2 is a control strategy block diagram of a voltage source converter at a distribution network interface in a first embodiment of the present invention;

[0065] Figure 3 is a control strategy block diagram of the AC load port voltage source converter in the first embodiment of the present invention;

[0066] Figure 4 is a control strategy block diagram of a photovoltaic power generation port boost converter in a first embodiment of the present invention;

[0067] Figure 5 is a control strategy block diagram of a bidirectional buck-boost converter at an energy storage port in a first embodiment of the present invention;

[0068] Figure 6 is a control strategy block diagram of a DC load port buck converter in a first embodiment of the present invention;

[0069] Figure 7 is a control strategy block diagram of a dual active bridge converter in a first embodiment of the present invention;

[0070] Figure 8 The common DC bus and DC side voltage waveforms of the grid-connected converter with and without a startup control strategy;

[0071] Fig. 9 It is a simulation diagram that simulates the buying and selling of electricity from the energy exchanger to the distribution system;

[0072] Fig.10 It is a simulation diagram of the interconnection of dual distribution systems. DETAILED DESCRIPTION

[0073] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0074] The first embodiment of the present invention relates to a control method for an AC / DC energy exchange system applicable to multiple scenarios, such as Figure 1 As shown, the following steps are included:

[0075] Step 1: determine the power electronic device used by the energy exchanger in the AC / DC energy exchange system, and use the power electronic device to connect the AC / DC energy exchange system to the power distribution network.

[0076] The power electronic devices used in the energy exchanger in this step include: a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, a storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter, and an internal dual active bridge converter of the energy exchanger.

[0077] Step 2: setting a control strategy for a power electronic device used by an energy exchanger in the AC / DC energy exchange system.

[0078] like Figure 2 As shown, in this step, the control strategy of the distribution network interface voltage source converter is set to: constant DC voltage and constant reactive power control.

[0079] like Figure 3 As shown, in this step, the control strategy of the AC load port voltage source converter is set to: adjust the grid frequency on the load side to the nominal value, and maintain the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system.

[0080] like Figure 4 As shown, in this step, the control strategy of the photovoltaic power generation port boost converter is set as follows: using the maximum power point tracking (MPPT) mode to adjust the operating voltage U PV To maximize the output; when the load demand is exceeded, it switches to constant voltage mode to limit the output, and controls the DC bus voltage U through PI control and PWM control. DC To stabilize the output voltage.

[0081] like Figure 5 As shown, in this step, the control strategy of the bidirectional buck-boost converter of the energy storage port is set as follows: in the grid-connected mode, it works in the constant power mode to meet the charging and discharging requirements of the grid; in the island mode or during a fault, it works in the constant voltage mode to maintain power balance and voltage stability.

[0082] like Figure 6 As shown, in this step, the control strategy of the DC load port buck converter is set to: constant voltage control, which can adopt a DC-DC buck circuit controlled by a voltage loop, specifically: ref As the load reference voltage, U o As the actual load voltage, the load reference voltage U is processed by the PI control and PWM unit ref and the actual load voltage U o The difference between them generates a control signal to achieve a constant output voltage.

[0083] like Figure 7 As shown, in this step, the control strategy of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy exchanger is set to: constant voltage control, and power transmission is adjusted by adjusting the phase shift angle.

[0084] Step 3: setting a coordinated control strategy for the interface of the energy exchanger in the AC / DC energy exchange system.

[0085] The coordinated control strategy of the interface of the energy exchanger in the AC / DC energy exchange system in this step is shown in Table 1.

[0086] Table 1 Coordinated control strategy table of the interface of the energy exchanger in the AC / DC energy exchange system

[0087]

[0088]

[0089] It can be seen from Table 1 that in this step, the coordinated control strategy of the distribution network interface of the energy exchanger in the AC / DC energy exchange system is set to: fixed active power control and fixed reactive power control; the coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system is set to: fixed frequency control and fixed AC port voltage amplitude (Usm) control; the coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system is set to: fixed low-voltage side DC voltage control; the coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system is set to: fixed active power control; the energy storage port of the energy exchanger in the AC / DC energy exchange system is set to: fixed frequency control and fixed AC port voltage amplitude (Usm) control. The coordinated control strategy of the interface is set to: fixed active power control; the coordinated control strategy of the interconnection interface of the switch in the AC / DC energy exchange system is set to: fixed active power control; the coordinated control strategy of the interface between the DC side bus of the grid-connected converter and the public DC bus in the energy exchanger in the AC / DC energy exchange system is set to: fixed converter side DC voltage control; the coordinated control strategy of the interface between the public DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system is set to: fixed DC bus voltage control at the multi-energy DC interface; the coordinated control strategy of the energy storage device interface in the energy exchanger in the AC / DC energy exchange system is set to: fixed public DC bus voltage control. Among them, the converter type of each interface is consistent with the power electronic device used in step 1.

[0090] Step 4, determining a startup control strategy for the energy exchanger in the AC / DC energy exchange system, and using the startup control strategy to precharge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system.

[0091] The startup control strategy of the energy exchanger in the AC / DC energy exchange system in this step includes the following three stages:

[0092] In the first stage, the switch between the DC side busbar of the grid-connected converter and the rest is disconnected, and only the grid-connected converter is connected to the AC distribution network; all control and switch tubes are locked, and the anti-parallel diode of the energy exchanger is used as a three-phase uncontrolled rectifier to uncontrollably charge the DC side capacitor of the energy exchanger;

[0093] In the second stage, the grid-connected converter is set to the power-quality mode to control the charging of the DC side capacitor to the DC voltage control value;

[0094] In the third stage, the switch between the DC busbar of the grid-connected converter and the rest is closed, all controls of the energy exchanger are turned on, and the startup of the energy exchanger is completed.

[0095] Figure 8 The common DC bus and DC side voltage waveforms of the grid-connected converter with and without the startup control strategy are given. It is not difficult to find that the startup control strategy in this step significantly reduces the transient impact by precharging the DC side of the grid-connected converter to the set value, thereby enhancing the stable operation of the converter and the system.

[0096] Fig. 9 This is a simulation diagram for simulating the purchase and sale of electricity from the energy exchanger to the distribution system, where (a) is the active power exchange waveform between the energy exchanger and the AC distribution network, (b) is the reactive power exchange waveform between the energy exchanger and the AC distribution network, (c) is the common DC bus voltage waveform, and (d) is the DC side voltage waveform of the grid-connected converter. It can be seen from the above waveforms that the energy exchanger can accurately adjust the transmission of active power to the distribution network and skillfully respond to changes in power commands while demonstrating minimal transient response and promoting flow optimization.

[0097] Fig.10 This is a simulation diagram of the interconnection of a dual distribution system, where (a) is the active power exchange waveform at the interconnection interface, (b) is the common DC bus voltage waveform, and (c) is the DC bus voltage waveform of the multi-energy DC interface. It can be seen from the above waveforms that the energy exchanger can adjust the transmission power according to the command value, and can quickly and accurately control the power even if the command value sign changes, thereby maintaining system voltage stability, demonstrating the power control and system stability of the energy exchanger in various scenarios.

[0098] A second embodiment of the present invention relates to an AC / DC energy exchange system control device applicable to multiple scenarios, comprising:

[0099] A determination module, used to determine a power electronic device used by an energy exchanger in an AC / DC energy exchange system, and use the power electronic device to connect the AC / DC energy exchange system to a power distribution network;

[0100] A first setting module, used to set a control strategy of a power electronic device used by an energy exchanger in the AC / DC energy exchange system;

[0101] A second setting module, used to set a coordinated control strategy of an interface of an energy exchanger in the AC / DC energy exchange system;

[0102] A startup control module is used to determine the startup control strategy of the energy exchanger in the AC / DC energy exchange system, and adopt the startup control strategy to pre-charge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system, and realize power mutual assistance and system power balance control in various operating modes under the control of the control strategy and the coordinated control strategy.

[0103] The power electronic device used in the energy exchanger in the AC / DC energy exchange system includes a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, an energy storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter and an internal dual active bridge converter of the energy exchanger.

[0104] The first setting module includes:

[0105] A first setting unit, configured to set the control strategy of the distribution network interface voltage source converter to: constant DC voltage and constant reactive power control;

[0106] A second setting unit is used to set the control strategy of the AC load port voltage source converter to: adjust the grid frequency on the load side to a nominal value, and maintain the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system;

[0107] A third setting unit is used to set the control strategy of the photovoltaic power generation port boost converter to: use the maximum power point tracking mode to adjust the operating voltage to maximize the output; when the load demand is exceeded, switch to the constant voltage mode to limit the output, and stabilize the output voltage according to the DC bus voltage through PI control and PWM control;

[0108] A fourth setting unit is used to set the control strategy of the bidirectional buck-boost converter of the energy storage port to: operate in a constant power mode in a grid-connected mode; operate in a constant voltage mode in an island mode or during a fault;

[0109] A fifth setting unit, configured to set the control strategy of the DC load port buck converter to: constant voltage control;

[0110] The sixth setting unit is used to set the control strategy of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy exchanger to: constant voltage control, and adjust power transmission by adjusting the phase shift angle.

[0111] The second setting module includes:

[0112] A seventh setting unit, used to set the coordinated control strategy of the power distribution network interface of the energy exchanger in the AC / DC energy exchange system to: fixed active power control and fixed reactive power control;

[0113] An eighth setting unit, used to set the coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system to: fixed frequency control and fixed Usm control;

[0114] A ninth setting unit, used to set the coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system to: set low-voltage side DC voltage control;

[0115] A tenth setting unit is used to set the coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system to: fixed active power control;

[0116] an eleventh setting unit, for setting a coordinated control strategy of an energy storage port of an energy exchanger in the AC / DC energy exchange system to: fixed active power control;

[0117] A twelfth setting unit is used to set the coordinated control strategy of the switch interconnection interface in the AC / DC energy exchange system to: fixed active power control;

[0118] A thirteenth setting unit is used to set the coordinated control strategy of the interface between the DC side bus of the grid-connected converter inside the energy exchanger of the AC / DC energy exchange system and the common DC bus to: set the DC voltage control on the converter side;

[0119] A fourteenth setting unit is used to set the coordinated control strategy of the interface between the common DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system as follows: setting the DC bus voltage control at the multi-energy DC interface;

[0120] The fifteenth setting unit is used to set the coordinated control strategy of the internal energy storage device interface of the energy exchanger in the AC / DC energy exchange system to: set common DC bus voltage control.

[0121] The startup control strategy of the energy exchanger in the AC / DC energy exchange system includes:

[0122] Disconnect the switch between the DC side busbar of the grid-connected converter and the rest of the parts, and only connect the grid-connected converter to the AC distribution network; lock all control and switch tubes, use the anti-parallel diode of the energy exchanger as a three-phase uncontrolled rectifier, and uncontrollably charge the DC side capacitor of the energy exchanger;

[0123] Setting the grid-connected converter to a power-quality mode to control the charging of the DC link capacitor to a DC voltage control value;

[0124] Close the switch between the DC side bus of the grid-connected converter and the rest, turn on all controls of the energy exchanger, and complete the startup of the energy exchanger.

[0125] A third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the first embodiment of the AC / DC energy exchange system control method applicable to multiple scenarios when executing the computer program.

[0126] A fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the AC / DC energy exchange system control method applicable to multiple scenarios of the first embodiment.

[0127] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0128] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0129] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0130] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0131] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A control method for an AC / DC energy exchange system applicable to multiple scenarios, characterized in that: The following steps are involved: Setting a control strategy for a power electronic device used in an energy exchanger in the AC / DC energy exchange system; Setting a coordinated control strategy for interfaces of energy exchangers in the AC / DC energy exchange system; Determine the startup control strategy of the energy exchanger in the AC / DC energy exchange system, and use the startup control strategy to pre-charge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system, and realize power mutual assistance and system power balance control in various operating modes under the control of the control strategy and coordinated control strategy.

2. The AC / DC energy exchange system control method applicable to multiple scenarios according to claim 1 is characterized in that: The power electronic device used in the energy exchanger in the AC / DC energy exchange system includes a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, an energy storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter and an internal dual active bridge converter of the energy exchanger.

3. The AC / DC energy exchange system control method applicable to multiple scenarios according to claim 2 is characterized in that: The control strategy of setting the power electronic device used by the energy exchanger in the AC / DC energy exchange system specifically includes: The control strategy of the distribution network interface voltage source converter is set as: constant DC voltage and constant reactive power control; The control strategy of the AC load port voltage source converter is set as follows: adjusting the grid frequency on the load side to a nominal value, and maintaining the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system; The control strategy of the photovoltaic power generation port boost converter is set as follows: using the maximum power point tracking mode to adjust the operating voltage to maximize the output; when the load demand is exceeded, switching to the constant voltage mode to limit the output, and stabilizing the output voltage according to the DC bus voltage through PI control and PWM control; The control strategy of the bidirectional buck-boost converter of the energy storage port is set as follows: in the grid-connected mode, it works in the constant power mode; in the island mode or during a fault, it works in the constant voltage mode; The control strategy of the DC load port buck converter is set to: constant voltage control; The control strategies of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy switch are set to: constant voltage control, and power transmission is adjusted by adjusting the phase shift angle.

4. The AC / DC energy exchange system control method applicable to multiple scenarios according to claim 1, characterized in that: The setting of the coordinated control strategy of the interface of the energy exchanger in the AC / DC energy exchange system specifically includes: setting the coordinated control strategy of the distribution network interface of the energy exchanger in the AC / DC energy exchange system to: fixed active power control and fixed reactive power control; The coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system is set to: fixed frequency control and fixed Usm control; The coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system is set as follows: fixed low-voltage side DC voltage control; The coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system is set as follows: fixed active power control; The coordinated control strategy of the energy storage port of the energy exchanger in the AC / DC energy exchange system is set as: fixed active power control; The coordinated control strategy of the interconnection interface of the exchanger in the AC / DC energy exchange system is set to: fixed active power control; the coordinated control strategy of the interface between the DC side bus of the grid-connected converter inside the energy exchanger in the AC / DC energy exchange system and the common DC bus is set to: fixed converter side DC voltage control; The coordinated control strategy of the interface between the common DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system is set as follows: DC bus voltage control at the multi-energy DC interface is set; The coordinated control strategy of the internal energy storage device interface of the energy exchanger in the AC / DC energy exchange system is set as: fixed common DC bus voltage control.

5. The AC / DC energy exchange system control method applicable to multiple scenarios according to claim 1, characterized in that: The startup control strategy of the energy exchanger in the AC / DC energy exchange system includes: Disconnect the switch between the DC side busbar of the grid-connected converter and the rest of the parts, and only connect the grid-connected converter to the AC distribution network; lock all control and switch tubes, use the anti-parallel diode of the energy exchanger as a three-phase uncontrolled rectifier, and uncontrollably charge the DC side capacitor of the energy exchanger; Setting the grid-connected converter to a power-quality mode to control the charging of the DC link capacitor to a DC voltage control value; Close the switch between the DC side bus of the grid-connected converter and the rest, turn on all controls of the energy exchanger, and complete the startup of the energy exchanger.

6. An AC / DC energy exchange system control device suitable for multiple scenarios, characterized in that: include: A first setting module, used to set a control strategy of a power electronic device used by an energy exchanger in the AC / DC energy exchange system; A second setting module, used to set a coordinated control strategy of an interface of an energy exchanger in the AC / DC energy exchange system; A startup control module is used to determine the startup control strategy of the energy exchanger in the AC / DC energy exchange system, and adopt the startup control strategy to pre-charge the DC side of the grid-connected converter to a set value to start the energy exchanger in the AC / DC energy exchange system, and realize power mutual assistance and system power balance control in various operating modes under the control of the control strategy and the coordinated control strategy.

7. The AC / DC energy exchange system control device applicable to multiple scenarios according to claim 6, characterized in that: The power electronic device used in the energy exchanger in the AC / DC energy exchange system includes a distribution network interface voltage source converter, an AC load port voltage source converter, a photovoltaic power generation port boost converter, an energy storage port bidirectional buck-boost converter, a DC load port buck converter, a switch interconnection interface dual active bridge converter and an internal dual active bridge converter of the energy exchanger.

8. The AC / DC energy exchange system control device applicable to multiple scenarios according to claim 7, characterized in that: The first setting module includes: A first setting unit is used to set the control strategy of the power distribution network interface voltage source converter to: constant DC voltage and constant reactive power control; A second setting unit is used to set the control strategy of the AC load port voltage source converter to: adjust the grid frequency on the load side to a nominal value, and maintain the voltage amplitude on the load side at the nominal voltage of the AC / DC energy exchange system; A third setting unit is used to set the control strategy of the photovoltaic power generation port boost converter to: use the maximum power point tracking mode to adjust the operating voltage to maximize the output; when the load demand is exceeded, switch to the constant voltage mode to limit the output, and stabilize the output voltage according to the DC bus voltage through PI control and PWM control; A fourth setting unit is used to set the control strategy of the bidirectional buck-boost converter of the energy storage port to: operate in a constant power mode in a grid-connected mode; operate in a constant voltage mode in an island mode or during a fault; A fifth setting unit, configured to set the control strategy of the DC load port buck converter to: constant voltage control; The sixth setting unit is used to set the control strategy of the dual active bridge converter of the switch interconnection interface and the dual active bridge converter inside the energy exchanger to: constant voltage control, and adjust power transmission by adjusting the phase shift angle.

9. The AC / DC energy exchange system control device applicable to multiple scenarios according to claim 6, characterized in that: The second setting module includes: A seventh setting unit, used to set the coordinated control strategy of the power distribution network interface of the energy exchanger in the AC / DC energy exchange system to: fixed active power control and fixed reactive power control; An eighth setting unit, used to set the coordinated control strategy of the AC load port of the energy exchanger in the AC / DC energy exchange system to: fixed frequency control and fixed Usm control; A ninth setting unit, used to set the coordinated control strategy of the DC load port of the energy exchanger in the AC / DC energy exchange system to: set low-voltage side DC voltage control; A tenth setting unit is used to set the coordinated control strategy of the photovoltaic power generation port of the energy exchanger in the AC / DC energy exchange system to: fixed active power control; an eleventh setting unit, for setting a coordinated control strategy of an energy storage port of an energy exchanger in the AC / DC energy exchange system to: fixed active power control; A twelfth setting unit is used to set the coordinated control strategy of the switch interconnection interface in the AC / DC energy exchange system to: fixed active power control; A thirteenth setting unit is used to set the coordinated control strategy of the interface between the DC side bus of the grid-connected converter inside the energy exchanger of the AC / DC energy exchange system and the common DC bus to: set the DC voltage control on the converter side; A fourteenth setting unit is used to set the coordinated control strategy of the interface between the common DC bus and the multi-energy DC interface in the energy exchanger in the AC / DC energy exchange system as follows: setting the DC bus voltage control at the multi-energy DC interface; The fifteenth setting unit is used to set the coordinated control strategy of the internal energy storage device interface of the energy exchanger in the AC / DC energy exchange system to: set common DC bus voltage control.

10. The AC / DC energy exchange system control device applicable to multiple scenarios according to claim 6, characterized in that: The startup control strategy of the energy exchanger in the AC / DC energy exchange system includes: Disconnect the switch between the DC side busbar of the grid-connected converter and the rest of the parts, and only connect the grid-connected converter to the AC distribution network; lock all control and switch tubes, use the anti-parallel diode of the energy exchanger as a three-phase uncontrolled rectifier, and uncontrollably charge the DC side capacitor of the energy exchanger; Setting the grid-connected converter to a power-quality mode to control the charging of the DC link capacitor to a DC voltage control value; Close the switch between the DC side bus of the grid-connected converter and the rest, turn on all controls of the energy exchanger, and complete the startup of the energy exchanger.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the AC / DC energy exchange system control method applicable to multiple scenarios as described in any one of claims 1-5 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the AC / DC energy exchange system control method applicable to multiple scenarios as described in any one of claims 1 to 5 are implemented.

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