Hybrid micro-grid operation control method and system based on centralized-decentralized architecture

Abstract

The invention discloses a hybrid micro-grid operation control method and system based on a centralized-decentralized architecture. The method comprises the following steps: establishing a grid-connected alternating-current and direct-current hybrid micro-grid system model; formulating a distributed power supply power regulation instruction for the grid-connected AC / DC hybrid micro-grid system model; designing a microgrid operation control strategy of a centralized-decentralized architecture for the grid-connected AC / DC hybrid microgrid system model based on the distributed power supply power regulation instruction; and carrying out operation control on the alternating current and direct current hybrid micro-grid according to the micro-grid operation control strategy of the centralized-distributed architecture. According to the invention, centralized control and distributed control are combined, the centralized controller can adjust the output power of the distributed power supply in real time according to the load power, and unapproved power is prevented from being reversely transmitted to the power grid while the utilization efficiency of renewable energy sources is improved. And each power conversion device adopts a master-slave control mode, so that the accurate distribution of renewable energy power can be realized under the condition of weakening communication, and the operation reliability of the micro-grid is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system dispatching automation, and particularly relates to a hybrid microgrid operation control method and system based on a centralized-decentralized architecture. Background Art

[0002] With the vigorous development of photovoltaics, due to the intermittency and volatility of renewable energy, its large-scale access poses a great challenge to the stable operation of the power grid. Microgrids provide an effective solution for the accommodation of renewable energy by integrating distributed power sources, energy storage units, power electronic devices, loads, monitoring and protection devices.

[0003] Microgrids have two operating modes: grid-connected operation and off-grid operation. In the grid-connected operation mode, the microgrid exchanges power with the distribution network through a common connection point to ensure the supply-demand balance within the microgrid and the stable operation of the system. In the off-grid operation mode, the microgrid relies on internal distributed power sources and energy storage units to maintain the stable operation of the system and ensure the power supply to critical loads. According to the type of microgrid bus voltage, microgrids can be divided into AC microgrids, DC microgrids, and AC-DC hybrid microgrids. Benefiting from the mature AC power system, AC microgrids have developed rapidly in recent years, and various technologies have become increasingly perfect. DC microgrids have a simpler topology structure, higher energy conversion efficiency, and do not require the adjustment of reactive power and frequency. However, a single type of bus voltage cannot meet the diverse needs of distributed power sources and loads within the microgrid. In contrast, AC-DC hybrid microgrids can combine the advantages of both, efficiently access different types of distributed energy and loads, and reduce the energy conversion link, thereby improving the flexibility and overall efficiency of the microgrid, and better meeting the actual engineering requirements.

[0004] With a large number of distributed power sources and loads connected to the AC-DC hybrid microgrid, and the continuous expansion of its scale, the requirements for the microgrid control strategy have become increasingly high. According to different communication condition requirements, the existing control methods are mainly divided into three types: centralized control, decentralized control, and distributed control. Under centralized control, each distributed power source collects the information of the corresponding system through the local controller and sends it to the centralized controller of the system. The centralized controller coordinates the power distribution and optimization management of each distributed power source. However, centralized control has excessive requirements for communication and is prone to "single-point failures". Once the communication facilities fail, the corresponding distributed power sources will no longer be controlled by the centralized controller, which will have a great impact on the stable operation of the system. In distributed control, the local controller of each distributed power source can communicate and interact with the controllers of other distributed power sources, and multiple local controllers cooperate for control. This can not only greatly reduce the computational pressure on a single controller, but also when a single communication line in the system fails, the remaining communication lines will not be affected, ensuring the stable operation of their respective systems, thereby improving the stability of the overall microgrid. However, distributed control has high requirements for the intelligence level of equipment and requires a high economic investment, and its control performance will also be affected by communication delays. In contrast, in decentralized control, each distributed power source can make independent decisions and coordinate operations, realizing a control architecture without a central node, thereby improving the reliability and fault tolerance of the system, reducing communication requirements, and enhancing the adaptability of the microgrid to dynamic changes. But there are also disadvantages such as the lack of global optimization ability and the difficulty in coordinating between distributed power sources, resulting in system instability.

[0005] In summary, the existing microgrid control strategies have their own advantages and disadvantages. The communication-based control strategy has high requirements for the computing power of the controller and communication conditions, while the communication-free decentralized control strategy has high requirements for the consistency between devices and the design of local control algorithms, and it is often difficult to achieve good control effects. Summary of the Invention

[0006] The purpose of the present invention is to provide a method and system for operating and controlling an AC-DC hybrid microgrid based on a centralized-decentralized architecture to improve the reliability, economy, and stability of the operation of the grid-connected AC-DC hybrid microgrid in view of the above problems in the existing technology.

[0007] To achieve the above purpose, the present invention has the following technical solutions:

[0008] In the first aspect, a method for operating and controlling an AC-DC hybrid microgrid based on a centralized-decentralized architecture is provided, including:

[0009] Establishing a system model of a grid-connected AC-DC hybrid microgrid;

[0010] Formulate distributed power adjustment instructions for the grid-connected AC-DC hybrid microgrid system model;

[0011] Based on the distributed power adjustment instructions, design a microgrid operation control strategy with a centralized-decentralized architecture for the grid-connected AC-DC hybrid microgrid system model;

[0012] Conduct the operation control of the AC-DC hybrid microgrid according to the microgrid operation control strategy with a centralized-decentralized architecture.

[0013] As a preferred solution, the grid-connected AC-DC hybrid microgrid system model includes two parts: a physical system and a control system;

[0014] The physical system consists of an AC microgrid system, an AC-DC interconnection conversion device, and a DC microgrid system;

[0015] The AC-DC interconnection conversion device is a DC / AC converter; the AC microgrid system has n lines. One side of the AC bus of each line is connected to the distribution network through a main transformer, and the other side is connected to the DC bus through an isolation transformer and a DC / AC converter to jointly supply power to the loads on the corresponding lines; the voltage and frequency of the AC bus are controlled by the distribution network; in the DC microgrid system, m groups of photovoltaic power generation systems and hydrogen fuel cell power generation systems respectively transmit power to the DC bus through DC / DC converters and all work as current sources without participating in the regulation of the DC bus voltage; the voltage of the DC bus is controlled by the distribution network through a DC / AC converter; an electrolytic water hydrogen production device and a hydrogen storage tank are also equipped to supply hydrogen to the hydrogen fuel cell;

[0016] The control system collects the operation data of the power generation system, DC / AC converter, and line load in real time and issues control instructions.

[0017] As a preferred solution, the step of formulating distributed power adjustment instructions for the grid-connected AC-DC hybrid microgrid system model realizes improving the utilization efficiency of renewable energy and avoiding unauthorized power backfeeding to the grid through the distributed power adjustment instructions.

[0018] As a preferred solution, the step of formulating distributed power adjustment instructions for the grid-connected AC-DC hybrid microgrid system model includes:

[0019] Collect the load power of each line and transmit it to the centralized controller to calculate the calculated load power of each line:

[0020]

[0021] where P Loadi is the load power of the i-th line, and P margin is the artificially set power margin, is the rated power of the AC-DC interconnected conversion device; when the load power Pi of the i-th line Loa minus the artificially set power margin P margin is less than the rated power of the AC-DC interconnected conversion device take it as Pi Load -P margin ; when the load power Pi of the i-th line Loadi minus the artificially set power margin P margin is greater than the rated power of the AC-DC interconnected conversion device take it as

[0022] Summarize the load powers of each line according to the following formula:

[0023]

[0024] where n is the number of lines of the AC microgrid in the microgrid system;

[0025] Do not perform real-time power regulation on the hydrogen fuel cell power generation system, and calculate the total power reference value of the photovoltaic power generation system according to the following formula:

[0026]

[0027] where Pi PEMFC is the real-time power of the hydrogen fuel cell power generation system;

[0028] If the photovoltaic power generation system consists of multiple photovoltaic arrays, the power reference value of a single photovoltaic array is calculated according to the following formula:

[0029]

[0030] where m is the number of photovoltaic arrays;

[0031] Calculate the actual output power command of each photovoltaic power generation system according to the following formula:

[0032]

[0033] where is the maximum output power of the i-th group of photovoltaic arrays operating in the maximum power point tracking (MPPT) mode; when the output power of the photovoltaic array operating in the MPPT mode is greater than the power reference value of the photovoltaic array take the actual output power Pi of the photovoltaic array as PVi take it as When is less than the power reference value of the photovoltaic array take the actual output power Pi of the photovoltaic array as PV take it as

[0034] As a preferred solution, the microgrid operation control strategy with a centralized - decentralized architecture designed for the grid - connected AC - DC hybrid microgrid system model based on the distributed power regulation instruction includes:

[0035] The DC power generated by the photovoltaic power generation system and the hydrogen fuel cell power generation system is converted into alternating current through the AC - DC interconnection and conversion devices of each line to supply the load, and the insufficient power is supplemented by the distribution network;

[0036] The power balance inside the microgrid satisfies the following relational expression:

[0037]

[0038] In the formula, P PVi is the real - time power of the i - th photovoltaic array, and there are m photovoltaic arrays in total; P PdNi is the power transmitted from the i - th distribution network to the i - th AC bus, and there are n AC bus lines in total, P loadi is the real - time load power of the i - th line;

[0039] For the i - th AC bus, the power balance of the AC bus satisfies the following relational expression:

[0040] P BICi +P PDNi =P loadi

[0041] In the formula, P BICi is the real - time power transmitted by the i - th AC - DC interconnection and conversion device.

[0042] As a preferred solution, the microgrid operation control strategy with a centralized - decentralized architecture designed for the grid - connected AC - DC hybrid microgrid system model based on the distributed power regulation instruction includes:

[0043] For l AC - DC interconnection and conversion devices, a droop control strategy is adopted, and the voltage reference value corresponding to the AC - DC interconnection and conversion device is calculated according to the following formula:

[0044]

[0045] In the formula, is the DC voltage tracking value of the i - th AC - DC interconnection and conversion device, is the DC bus reference value, k i is the droop coefficient, i BICi is the DC current value of the AC - DC interconnection and conversion device;

[0046] Considering the voltage drop generated by the line impedance on the DC bus voltage, there is the following relational expression:

[0047] v DC = v BIC - R i × i BICi

[0048] Wherein, v BIC is the terminal voltage value of the i-th AC-DC interconnected conversion device, and R i is the line impedance value;

[0049] The voltage values at the connection points of each AC-DC interconnected conversion device and the DC bus are:

[0050]

[0051] There is the following relational expression:

[0052]

[0053] The power distribution ratio of the AC-DC interconnected conversion device is inversely proportional to the line impedance R i and the designed droop coefficient k i inverse ratio:

[0054]

[0055] Set the droop coefficient k i to be much greater than the line impedance R1:

[0056] k i >> R i

[0057] The following current distribution ratio is obtained:

[0058]

[0059] By designing the droop coefficient k i , the power distribution ratio of the selected l AC-DC interconnected conversion devices is achieved without communication;

[0060] For the remaining n-l AC-DC interconnected conversion devices operating in the constant power mode, calculate the load power through the obtained lines, and the centralized controller sends the corresponding power commands:

[0061]

[0062] In a second aspect, a hybrid microgrid operation control system based on a centralized-decentralized architecture is provided, including:

[0063] A system model establishment module for establishing a grid-connected AC-DC hybrid microgrid system model;

[0064] A distributed power generation power regulation instruction formulation module, which is used to formulate distributed power generation power regulation instructions for a grid-connected AC-DC hybrid microgrid system model;

[0065] A microgrid operation control strategy design module, which is used to design a microgrid operation control strategy with a centralized-decentralized architecture for the grid-connected AC-DC hybrid microgrid system model based on the distributed power generation power regulation instructions;

[0066] A microgrid operation control strategy execution module, which is used to perform the operation control of the AC-DC hybrid microgrid according to the microgrid operation control strategy with a centralized-decentralized architecture.

[0067] In a third aspect, an electronic device is provided, including a processor and a memory. The processor is used to execute a computer program stored in the memory to implement the hybrid microgrid operation control method based on the centralized-decentralized architecture.

[0068] In a fourth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores at least one instruction, and when the at least one instruction is executed by a processor, the hybrid microgrid operation control method based on the centralized-decentralized architecture is implemented.

[0069] In a fifth aspect, a computer program product is provided, including a computer program stored in a non-volatile storage medium. When the computer program is executed by a processor, the hybrid microgrid operation control method based on the centralized-decentralized architecture is implemented.

[0070] Compared with the prior art, the present invention has at least the following beneficial effects:

[0071] By establishing a grid-connected AC-DC hybrid microgrid system model, formulating distributed power generation power regulation instructions for the grid-connected AC-DC hybrid microgrid system model, and designing a microgrid operation control strategy with a centralized-decentralized architecture for the grid-connected AC-DC hybrid microgrid system model, combining centralized control and decentralized control, the centralized controller can adjust the output power of distributed power generation in real time according to the load power, which can improve the utilization efficiency of renewable energy while avoiding unauthorized power backfeeding to the grid. Each power conversion device adopts a master-slave control mode. The master is responsible for adjusting the system power, and the slave transmits power according to the line load power collected in real time, which can achieve precise allocation of renewable energy power and improve the operation reliability of the microgrid under the condition of weakening communication. The hybrid microgrid operation control method based on the centralized-decentralized architecture of the present invention truly realizes the integration of information technology into the microgrid centralized control system, enables the microgrid centralized control system to have advanced intelligent decision-making capabilities, and helps to improve the reliability, economy and stability of the grid-connected AC-DC hybrid microgrid. Description of the Drawings

[0072] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for use in the embodiments or the description of the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0073] Figure 1 Schematic diagram of the electrical topology of the grid-connected AC-DC hybrid microgrid system in the embodiments of the present invention;

[0074] Figure 2 Flowchart for formulating the power regulation instructions of distributed power sources in the embodiments of the present invention;

[0075] Figure 3 Schematic diagram of the DC bus voltage drop caused by the line impedance in the embodiments of the present invention. Detailed implementation manners

[0076] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should understand that the present application can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0077] Please refer to Figure 1 , the method for operating and controlling a hybrid microgrid based on a centralized-decentralized architecture in the embodiments of the present invention includes:

[0078] S1. Establish a grid-connected AC-DC hybrid microgrid system model;

[0079] S2. Formulate power regulation instructions for distributed power sources for the grid-connected AC-DC hybrid microgrid system model;

[0080] S3. Based on the power regulation instructions of distributed power sources, design a microgrid operation control strategy with a centralized-decentralized architecture for the grid-connected AC-DC hybrid microgrid system model;

[0081] S4. Perform the operation control of the AC-DC hybrid microgrid according to the microgrid operation control strategy with a centralized-decentralized architecture.

[0082] In a possible implementation manner, the grid-connected AC-DC hybrid microgrid system model described in step S1 includes two parts: a physical system and a control system;

[0083] Among them, the physical system is composed of an AC microgrid system, an AC-DC interconnection and conversion device, and a DC microgrid system;

[0084] The AC-DC interconnected conversion device is a DC / AC converter; the AC microgrid system has a total of n lines. One side of the AC bus of each line is connected to the distribution network through a main transformer, and the other side is connected to the DC bus through an isolation transformer and a DC / AC converter to jointly supply power to the loads on the corresponding lines; the voltage and frequency of the AC bus are controlled by the distribution network;

[0085] The distribution network in the embodiment of the present invention is 10 kV;

[0086] In the DC microgrid system, m groups of photovoltaic power generation systems and hydrogen fuel cell power generation systems respectively transmit power to the DC bus through DC / DC converters and all work as current sources without participating in the regulation of the DC bus voltage; the voltage of the DC bus is controlled by the 10 kV distribution network through a DC / AC converter; in addition, to ensure the hydrogen supply of the hydrogen fuel cell, the system is also equipped with an electrolytic water hydrogen production device and a hydrogen storage tank.

[0087] The control system collects the operation data of the power generation systems (photovoltaic, hydrogen fuel cell), DC / AC converters, and line loads in real time and issues control instructions.

[0088] In a possible implementation manner, step S2 realizes improving the utilization efficiency of renewable energy and avoiding unauthorized power inversion to the grid through the distributed power regulation instruction, and the power instruction calculation process of the distributed power source is as Figure 2 shown.

[0089] First, the load power of each line is collected through an intelligent electricity meter and transmitted to the centralized controller to calculate the calculated load power of each line:

[0090]

[0091] In the formula, P Loadi is the load power of the i-th line, P margin is the artificially set power margin, is the rated power of the AC-DC interconnected conversion device; when the load power P Loadi of the i-th line minus the artificially set power margin P margin is less than the rated power of the AC-DC interconnected conversion device, take it as P Loadi -P margin , when the load power P Loadi of the i-th line minus the artificially set power margin P margin is greater than the rated power of the AC-DC interconnected conversion device, take it as

[0092] Subsequently, summarize the load power of each line according to the following formula:

[0093]

[0094] In the formula, n is the number of lines of the AC microgrid in the microgrid system;

[0095] Considering that the hydrogen fuel cell power generation system involves complex electrochemical reactions, resulting in slow dynamic response, its real-time power adjustment is not performed. The total power reference value of the photovoltaic power generation system is calculated according to the following formula:

[0096]

[0097] In the formula, P PEMFC is the real-time power of the hydrogen fuel cell power generation system;

[0098] The photovoltaic power generation system is composed of multiple photovoltaic arrays. Then, the power reference value of a single photovoltaic array is calculated according to the following formula:

[0099]

[0100] In the formula, m is the number of photovoltaic arrays;

[0101] Thus far, the actual output power command of each photovoltaic power generation system can be calculated according to the following formula:

[0102]

[0103] In the formula, is the maximum output power of the i-th group of photovoltaic arrays operating in the MPPT (Maximum Power Point Tracking) mode; when the output power of the photovoltaic array operating in the MPPT mode is greater than the power reference value of the photovoltaic array at this time, the actual output power P of the photovoltaic array PVi is taken as When is less than the power reference value of the photovoltaic array at this time, the actual output power P of the photovoltaic array PV is taken as

[0104] In a possible implementation manner, step S3 is that the microgrid operation control strategy for designing a centralized-decentralized architecture in the grid-connected AC-DC hybrid microgrid system model includes:

[0105] The DC power generated by the photovoltaic power generation system and the hydrogen fuel cell power generation system is converted into alternating current through the AC-DC interconnection conversion devices of each line and supplied to the load, and the insufficient power is supplemented by the distribution network;

[0106] The power balance inside the microgrid satisfies the following relational expression:

[0107]

[0108] Wherein, P PV is the real-time power of the i-th photovoltaic array, and there are m photovoltaic arrays in total; P PDNi is the power transmitted from the i-th distribution network to the i-th AC bus, and there are n AC bus lines in total, P load is the real-time load power of the i-th line;

[0109] For the i-th AC bus, the power balance of the AC bus satisfies the following relationship:

[0110] P BICi +P PDNi =P loadi (7)

[0111] Wherein, P BICi is the real-time power transmitted by the i-th AC-DC interconnection conversion device.

[0112] In the designed centralized-decentralized architecture control strategy, in order to maintain the stability of the DC bus voltage and achieve power distribution under the condition of no communication, a droop control strategy is adopted for l AC-DC interconnection conversion devices, and the voltage reference value corresponding to the AC-DC interconnection conversion device is calculated according to the following formula:

[0113]

[0114] Wherein, is the DC voltage tracking value of the i-th AC-DC interconnection conversion device, is the DC bus reference value, k i is the droop coefficient, i BICi is the DC current value of the AC-DC interconnection conversion device;

[0115] In addition, the voltage drop generated by the line impedance on the DC bus voltage needs to be considered, as shown in Figure 3 as follows:

[0116] v DC =v BICi -R i ×i BICi (9)

[0117] Wherein, v BICi is the terminal voltage value of the i-th AC-DC interconnection conversion device, R i is the line impedance value;

[0118] Combining formulas (8) and (9), the voltage value at the connection point of each AC-DC interconnection conversion device and the DC bus can be obtained as:

[0119]

[0120] There is the following relational expression:

[0121]

[0122] It can be seen from formula (10) that the power distribution ratio of the AC-DC interconnected conversion device is inversely proportional to the line impedance R i and the designed droop coefficient k i inverse ratio of:

[0123]

[0124] Set the droop coefficient k i much greater than the line impedance R1:

[0125] k i >> R i (13)

[0126] The following current distribution ratio is obtained:

[0127]

[0128] This indicates that under condition (12), the current distribution ratio (13) is determined by the designed droop coefficient k i That is to say, by designing the droop coefficient k i , the power distribution ratio of the selected l AC-DC interconnected conversion devices is achieved without communication conditions;

[0129] For the remaining n-l AC-DC interconnected conversion devices operating in the constant power mode, calculate the load power through the obtained lines, and the centralized controller sends the corresponding power command to it, so as to achieve precise power distribution:

[0130]

[0131] The operation control method of the hybrid microgrid based on the centralized-decentralized architecture in the embodiment of the present invention formulates the power regulation command of the distributed power supply through step S2, which can improve the utilization efficiency of renewable energy while avoiding unauthorized power inversion to the power grid; by designing the operation control strategy of the microgrid with the centralized-decentralized architecture in step S3, it can achieve precise distribution of renewable energy power and improve the operation reliability of the microgrid under the condition of weakening communication. The operation control method of the hybrid microgrid based on the centralized-decentralized architecture in the embodiment of the present invention truly integrates information technology into the microgrid centralized control system, enabling the microgrid centralized control system to have advanced intelligent decision-making capabilities.

[0132] Another embodiment of the present invention also proposes a hybrid microgrid operation control system based on a centralized-decentralized architecture, including:

[0133] A system model establishment module, configured to establish a grid-connected AC-DC hybrid microgrid system model;

[0134] A distributed power source power regulation instruction formulation module, configured to formulate distributed power source power regulation instructions for the grid-connected AC-DC hybrid microgrid system model;

[0135] A microgrid operation control strategy design module, configured to design a microgrid operation control strategy with a centralized-decentralized architecture for the grid-connected AC-DC hybrid microgrid system model based on the distributed power source power regulation instructions;

[0136] A microgrid operation control strategy execution module, configured to perform the operation control of the AC-DC hybrid microgrid according to the microgrid operation control strategy with a centralized-decentralized architecture.

[0137] Another embodiment of the present invention further provides an electronic device, including a processor and a memory, where the processor is configured to execute a computer program stored in the memory to implement the hybrid microgrid operation control method based on the centralized-decentralized architecture.

[0138] Another embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores at least one instruction, and when the at least one instruction is executed by a processor, the hybrid microgrid operation control method based on the centralized-decentralized architecture is implemented.

[0139] Another embodiment of the present invention further provides a computer program product, including a computer program stored in a non-volatile storage medium, where when the computer program is executed by a processor, the hybrid microgrid operation control method based on the centralized-decentralized architecture is implemented.

[0140] The computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable storage medium may include: any entity or device, medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals. For the convenience of description, only the parts related to the embodiments of the present invention are shown above. For the specific technical details not disclosed, please refer to the method part of the embodiments of the present invention. This computer-readable storage medium is non-transitory and can be stored in a storage device formed by various electronic devices, and can implement the execution process recorded in the method of the embodiments of the present invention.

[0141] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems) and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram can be realized by computer program instructions, and the combination of flows and / or blocks in the flowchart and / or block diagram can also be realized. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0143] These computer program instructions can also be stored in a computer-readable memory capable of guiding the computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device realizes the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0144] These computer program instructions can also be loaded onto the computer or other programmable data processing devices, so that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process, and the instructions executed on the computer or other programmable devices provide steps for realizing the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: still can modify the specific implementation manners of the present invention or make equivalent replacements, and any modification or equivalent replacement without departing from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A hybrid microgrid operation control method based on a centralized-decentralized architecture, characterized in that: include: Establish a grid-connected AC / DC hybrid microgrid system model; Formulate distributed power generation power regulation instructions for the grid-connected AC / DC hybrid microgrid system model; Based on the power regulation instructions of distributed power sources, a centralized-decentralized microgrid operation control strategy is designed for the grid-connected AC / DC hybrid microgrid system model; The operation control of the AC / DC hybrid microgrid is carried out according to the microgrid operation control strategy of the centralized-decentralized architecture.

2. The hybrid microgrid operation control method based on centralized-decentralized architecture according to claim 1 is characterized in that: The grid-connected AC / DC hybrid microgrid system model includes two parts: a physical system and a control system; The physical system consists of an AC microgrid system, an AC / DC interconnection conversion device, and a DC microgrid system; The AC / DC interconnection conversion device is a DC / AC converter; the AC microgrid system has a total of n lines, one side of the AC bus of each line is connected to the distribution network through the main transformer, and the other side is connected to the DC bus through the isolation transformer and DC / AC converter, which jointly supply power to the load on the corresponding line; the voltage and frequency of the AC bus are controlled by the distribution network; in the DC microgrid system, m groups of photovoltaic power generation systems and hydrogen fuel cell power generation systems transmit power to the DC bus through DC / DC converters respectively, and both work as current sources and do not participate in the regulation of the DC bus voltage; the voltage of the DC bus is controlled by the distribution network through the DC / AC converter; it is also equipped with a water electrolysis hydrogen production device and a hydrogen storage tank to supply hydrogen to the hydrogen fuel cell; The control system collects the operating data of the power generation system, DC / AC converter and line load in real time and issues control instructions.

3. The hybrid microgrid operation control method based on centralized-decentralized architecture according to claim 1 is characterized in that: The step of formulating distributed power supply power regulation instructions for the grid-connected AC / DC hybrid microgrid system model can improve the utilization efficiency of renewable energy and avoid unauthorized power backflow to the power grid through the distributed power supply power regulation instructions.

4. The hybrid microgrid operation control method based on centralized-decentralized architecture according to claim 3 is characterized in that: The step of formulating a distributed power supply power regulation instruction for the grid-connected AC / DC hybrid microgrid system model comprises: Collect the load power of each line and transmit it to the centralized controller to calculate the calculated load power of each line: Where P Loadi is the load power of the ith line, P margin is an artificially set power margin. is the rated power of the AC / DC interconnection conversion device; when the load power P of the i-th line Loadi Subtract the artificially set power margin P margin Less than the rated power of the AC / DC interconnection conversion device When P Loadi -P margin , when the load power P of the i-th line Loadi Subtract the artificially set power margin P margin Greater than the rated power of the AC / DC interconnection conversion device When The load power of each line is summarized as follows: Where n is the number of AC microgrid lines in the microgrid system; Without real-time power regulation of the hydrogen fuel cell power generation system, the total power reference value of the photovoltaic power generation system is calculated as follows: Where P PEMFC Real-time power for hydrogen fuel cell power generation system; The photovoltaic power generation system consists of multiple photovoltaic arrays, and the power reference value of a single photovoltaic array is calculated as follows: Where m is the number of photovoltaic arrays; The actual output power command of each photovoltaic power generation system is calculated as follows: In the formula, is the maximum output power of the ith photovoltaic array working in the maximum power point tracking MPPT mode; when the photovoltaic array works in the MPPT mode, the output power Greater than the power reference value of the photovoltaic array When the actual output power of the photovoltaic array is P PV Take when Less than the power reference value of the photovoltaic array When the actual output power of the photovoltaic array is P PV Take 5. The hybrid microgrid operation control method based on centralized-decentralized architecture according to claim 1 is characterized in that: The microgrid operation control strategy of designing a centralized-decentralized architecture for a grid-connected AC / DC hybrid microgrid system model based on distributed power supply power regulation instructions includes: The DC power generated by the photovoltaic power generation system and the hydrogen fuel cell power generation system is converted into AC power to supply the load through the AC / DC interconnection conversion devices of each line, and the insufficient power is supplemented by the distribution network; The power balance inside the microgrid satisfies the following relationship: Where P PVi is the real-time power of the i-th photovoltaic array, there are m photovoltaic arrays in total; P PDNi is the power transmitted from the ith distribution network to the ith AC bus. There are n AC bus lines in total. P load is the real-time load power of the i-th line; For the i-th AC bus, the power balance of the AC bus satisfies the following relationship: P BICi +P PDNi =P loadi Where P BICi is the real-time power transmitted by the i-th AC / DC interconnection conversion device.

6. The hybrid microgrid operation control method based on centralized-decentralized architecture according to claim 5 is characterized in that: The microgrid operation control strategy of designing a centralized-decentralized architecture for a grid-connected AC / DC hybrid microgrid system model based on distributed power supply power regulation instructions includes: The droop control strategy is adopted for one AC / DC interconnection conversion device, and the voltage reference value of the corresponding AC / DC interconnection conversion device is calculated as follows: In the formula, is the DC voltage tracking value of the i-th AC / DC interconnection conversion device, is the DC bus reference value, k i is the droop coefficient, i BICi is the DC current value of the AC / DC interconnection conversion device; Considering the voltage drop caused by line impedance on the DC bus voltage, the following relationship exists: v DC =v BICi -R i ×i BICi In the formula, v BICi is the terminal voltage value of the i-th AC / DC interconnection conversion device, R i is the line impedance value; The voltage value of each AC / DC interconnection conversion device and the DC bus connection point is: The following relationship exists: The power distribution ratio of the AC / DC interconnection conversion device is inversely proportional to the line impedance R i and the designed droop coefficient k i The inverse of: Set the droop coefficient k i Much larger than the line impedance R1: k i >>R i The following current distribution ratio is obtained: By designing the droop coefficient k i , so that the power distribution ratio of the selected l AC / DC interconnection conversion device can be realized without the need for communication; The remaining nl AC / DC interconnection conversion devices work in constant power mode, and the load power is calculated through each line, and the corresponding power command is sent by the centralized controller:

7. A hybrid microgrid operation control system based on a centralized-decentralized architecture, characterized in that: include: System model building module, used to build a grid-connected AC / DC hybrid microgrid system model; A distributed power source power regulation instruction formulation module is used to formulate distributed power source power regulation instructions for a grid-connected AC / DC hybrid microgrid system model; Microgrid operation control strategy design module, which is used to design a centralized-decentralized microgrid operation control strategy for the grid-connected AC / DC hybrid microgrid system model based on the distributed power source power regulation instructions; The microgrid operation control strategy execution module is used to perform operation control of the AC / DC hybrid microgrid according to the microgrid operation control strategy of the centralized-decentralized architecture.

8. An electronic device, characterized in that: It comprises a processor and a memory, wherein the processor is used to execute a computer program stored in the memory to implement a hybrid microgrid operation control method based on a centralized-decentralized architecture as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one instruction, and when the at least one instruction is executed by a processor, the hybrid microgrid operation control method based on a centralized-decentralized architecture as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program stored in a non-volatile storage medium, characterized in that: When the computer program is executed by a processor, the hybrid microgrid operation control method based on a centralized-decentralized architecture as described in any one of claims 1 to 6 is implemented.

Images