Intelligent voltage control method for remote micro-grid based on power and information dual complex modulation strategy

Abstract

This invention provides a method for intelligent voltage control in remote microgrids based on a dual power and information modulation strategy, belonging to the field of power electronics and energy technology. Addressing the complex and challenging realities of constructing microgrids in remote mountainous areas, a novel power / information dual modulation strategy is proposed, utilizing the power conversion characteristics of power electronic converters to achieve "communication-free" communication. Specifically, advanced orthogonal frequency division multiplexing (OFDM) is employed to achieve data reception and transmission through signal modulation and demodulation. Furthermore, the potential for data transmission delays in practice is considered in the system modeling, thus more closely approximating the requirements of actual engineering projects. Finally, a corresponding dynamic voltage co-controller is designed to achieve intelligent voltage control, ensuring the stability of the microgrid.

Description

Technical Field

[0001] This invention relates to the field of power electronics and power technology, and in particular to a method for intelligent voltage control of remote microgrids based on a dual composite modulation strategy of power and information. Background Technology

[0002] Northwest China, particularly Inner Mongolia, Gansu, and Xinjiang, possesses abundant wind energy resources. These regions experience strong and stable winds, providing suitable conditions for large-scale wind farms. Xinjiang, Gansu, and Qinghai also enjoy long hours of sunshine and strong solar radiation, making them ideal for large-scale photovoltaic power plants. Furthermore, the abundance of land resources and relatively sparse populations in these areas provide ample space for the construction of large-scale new energy facilities.

[0003] However, renewable energy generation is characterized by randomness and volatility. To better absorb renewable energy, microgrids have become a focus of attention. However, due to the complex spatial environment and considering the actual economic and financial situation of the region, the common microgrid model with external communication lines is clearly unsuitable for the actual development requirements of the area. Therefore, designing appropriate data transmission strategies and corresponding intelligent control strategies to maintain the stability of the microgrid based on the actual requirements of local engineering projects is a crucial and challenging task. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a method for intelligent voltage control in remote microgrids based on a power / information dual composite modulation strategy. Addressing the complex and challenging realities of microgrid construction in remote mountainous areas, this invention proposes a novel, "communication-enabled" power and information dual composite modulation strategy, utilizing the power conversion characteristics of power electronic converters to achieve "communication-free" AC communication. A corresponding dynamic voltage co-controller is designed to achieve intelligent voltage control, ensuring the stability of the microgrid.

[0005] On the one hand, the present invention provides a method for intelligent voltage control of remote microgrids based on a dual composite modulation strategy of power and information, comprising the following steps:

[0006] Step 1: Design the microgrid model;

[0007] Step 1.1: Construct the overall framework of the microgrid physical model; specifically, construct a DC bus, connect it to a bidirectional DC / DC converter, and connect all users and public facilities to it;

[0008] Step 1.2: Establish a physical model of the islanded microgrid based on Kirchhoff's current and voltage laws, and obtain the following relationship:

[0009] ;

[0010] in, , and These are the resistors, inductors, and capacitors that make up the filter. It is the capacitor voltage. It is the output voltage of the power electronic converter; It is inductor current. It is a regional load;

[0011] Step 1.3: Design the voltage controller;

[0012] The voltage controller is shown below:

[0013] ;

[0014] in, , and It is the voltage proportional-integral controller coefficient in the design; This is the voltage reference value;

[0015] Step 1.4: Design a voltage droop controller to achieve voltage management by simulating the characteristics of a synchronous generator;

[0016] The voltage droop controller is shown below:

[0017] ;

[0018] in, Indicates the rated bus voltage; Indicates the first The droop gain of a voltage droop controller for a distributed power source; Indicates the first The reactive power of a distributed power source; This represents the voltage deviation value in an actual microgrid.

[0019] Step 1.5: Design about The controller is as follows:

[0020] ;

[0021] in, and Represents parameters of a traditional PI controller; Represents the input of the microgrid system;

[0022] Step 1.6: Based on steps 1.2-1.5, the constructed microgrid model is shown below:

[0023] ;

[0024] in, Representing the first in the microgrid The state variables of a distributed power source For the first The derivatives of the state variables of a distributed power source; Representing the The integral of the voltage deviation of a distributed power source; Representing the The product of the input integral of a distributed power source and the PI controller parameters; This represents disturbances caused by distributed generation in a microgrid. Representing the first in a microgrid The output variables of each distributed power source are also the system output voltages. State parameter matrix. Input parameter matrix Output parameter matrix and perturbation parameter matrix They are as follows:

[0025] , , , ;

[0026] in, , These are the parameters of the PI controller; For auxiliary matrix, Indicates the first The droop gain of the voltage droop controller for a distributed power source; auxiliary matrix of state parameters. Input parameter auxiliary matrix Output parameter auxiliary matrix As shown below:

[0027] ;

[0028] Step 2: For novel power electronic converters in islanded microgrids, a dual composite modulation strategy for power and information is proposed.

[0029] Step 2.1: Use a fixed duty cycle power converter and select two degrees of freedom: switching frequency and initial phase.

[0030] Step 2.2: Select a switching frequency of... The data carrier frequency is ;

[0031] Step 2.3: Modulate the data onto a low-frequency data carrier, and then modulate it onto a power carrier using PWM; then, set the system's output voltage as the target signal, modulate the data into an output voltage ripple, and transmit it through the power line;

[0032] Step 2.4: Use Orthogonal Frequency Division Multiplexing (OFDM) to achieve data reception and transmission through signal modulation and demodulation;

[0033] Specifically, this includes: first, performing serial-to-parallel data conversion: serial baseband data is sequentially converted into four sets of parallel baseband data, and then distributed to four channel subcarriers; then, each carrier is modulated based on the dual-carrier differential phase shift keying method.

[0034] Step 3: Incorporate the data transmission delay issue into the system modeling and construct a microgrid physical model that takes into account the actual data transmission delay. Specifically, serial data is transmitted through continuous harmonics to calculate the delay time, thus obtaining the microgrid physical model that takes into account the actual data transmission delay.

[0035] The physical model of the microgrid is as follows:

[0036] ;

[0037] in, Represents the state error of the microgrid system; Distributed power sources representing neighbors; This represents the input time delay in the system and satisfies... ; Represents the number of neighboring distributed power sources; It is a vector that can be known based on the actual set voltage.

[0038] Step 4: Design a corresponding dynamic voltage coordination controller to meet the voltage quality requirements of the actual microgrid;

[0039] Step 4.1: Based on the physical model of the microgrid with actual input delay, the output voltage control problem is transformed into a problem of consistency or inclusion of the output of a multi-agent system, so as to design a corresponding dynamic cooperative output feedback controller;

[0040] For microgrids that are single-bus systems, a corresponding dynamic cooperative output feedback controller is designed as follows:

[0041] ;

[0042] in, and It is about controlling the gain. It is the state vector estimated for the power system; It is the first A dynamic observer for a distributed power source; This represents the number of distributed power sources.

[0043] Step 4.2: The designed power system state estimator is shown below:

[0044] ;

[0045] Step 4.3: Based on multi-agent graph theory, design the first... A dynamic observer for a distributed power source is shown below:

[0046] ;

[0047] in, , Representing the Dynamic observation vectors of a distributed power source; It is a positive number; Represents a known matrix; Represents the adjacency matrix in multi-agent graph theory; This represents the leader adjacency matrix in multi-agent graph theory.

[0048] Step 4.4: Calculate the unknown state matrix according to the following formula. :

[0049] ;

[0050] Step 4.5: Calculate the unknown state matrix according to the following formula. :

[0051] ;

[0052] Step 4.6: Based on the calculated matrix and The positive definite matrix is ​​obtained by using LMI. Then, the control gain is obtained according to the following formula. and :

[0053] ;

[0054] Step 4.7: Use the designed power and information dual composite modulation strategy, as well as the dynamic cooperative output feedback controller, to make the output voltage of each distributed power unit consistent and maintain the stability of the power system bus voltage.

[0055] Step 4.8: Set the voltage deviation value The voltage reference value is obtained by feeding it into the voltage droop controller. Then, based on the voltage obtained by the controller, the duty cycle required by the power electronic controller is obtained through PWM modulation, thus realizing intelligent voltage control in the absence of communication.

[0056] The beneficial effects of adopting the above technical solution are as follows:

[0057] This invention provides a method for intelligent voltage control in remote microgrids based on a dual composite modulation strategy of power and information. This method is primarily applied to islanded microgrids with power converters, addressing the issue that the common microgrid model with external communication lines is unsuitable for the actual development requirements of such regions due to complex spatial environments and economic constraints. This scheme utilizes the power conversion characteristics of power electronic converters to achieve "communication-free" AC transmission. By combining orthogonal frequency division multiplexing (OFDM) and frequency shift keying (FSK) methods, data reception and transmission are achieved through signal modulation and demodulation. Furthermore, the potential for data transmission delays in practice is considered in the system modeling, thus more closely approximating the requirements of actual engineering projects. Attached Figure Description

[0058] Figure 1 This is the overall control block diagram of the microgrid system of the present invention;

[0059] Figure 2 This is a block diagram of the signal modulation and demodulation process in the power and information dual composite modulation strategy of the present invention;

[0060] Figure 3 The power and data harmonic results in the power and information dual composite modulation strategy of this invention;

[0061] Figure 4 The output voltage amplitude of each distributed power unit in the microgrid system of this invention is given. Detailed Implementation

[0062] The specific implementation methods of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0063] Example 1:

[0064] On the one hand, this invention provides a method for intelligent voltage control of remote microgrids based on a dual composite modulation strategy of power and information, such as... Figure 1 As shown, it includes the following steps:

[0065] Step 1: In this embodiment, a stable microgrid model that meets the electricity needs of remote areas (northwest) in China is designed.

[0066] Step 1.1: Construct the overall framework of a smart "self-production and self-sales" microgrid physical model that is suitable for remote areas of China (mainly the northwest); specifically, construct a DC bus, connect it to a bidirectional DC / DC converter, and connect all users and public facilities to it;

[0067] Northwest China (including Gansu, Xinjiang, and Qinghai) is characterized by vast deserts and pastures, sparse population, abundant wind and solar resources, and harsh climate. Microgrids in this region cannot simply replicate urban or rural models in eastern China; instead, a highly resilient, easily scalable, and entirely green physical system should be established. A village-level DC bus should be constructed, connecting all households and public facilities. Each household connects to the bus via a bidirectional DC / DC converter, achieving "individual self-governance and village-level mutual assistance."

[0068] Step 1.2: Establish a physical model of the islanded microgrid based on Kirchhoff's current and voltage laws, and obtain the following relationship:

[0069] ;

[0070] in, , and These are the resistors, inductors, and capacitors that make up the filter; in practice, the resistors are chosen to be very small. It is the capacitor voltage, and also the system output voltage; It is the output voltage of the power electronic converter; It is both inductor current and system current; It is a regional load, usually represented by an unknown current source.

[0071] Step 1.3: To achieve the goal of "autonomy" in remote areas, a "plug-and-play" voltage controller needs to be designed at the underlying primary control level to enable flexible adjustment of distributed power sources (mainly photovoltaic and wind turbines) and various loads.

[0072] The voltage controller is shown below:

[0073] ;

[0074] in, , and It is the voltage proportional-integral controller coefficient in the design; This is the voltage reference value. This is typically provided by the voltage droop controller designed.

[0075] Step 1.4: Design a voltage droop controller to achieve voltage management by simulating the characteristics of a synchronous generator;

[0076] The voltage droop controller is shown below:

[0077] ;

[0078] in, Indicates the rated bus voltage; Indicates the first The droop gain of a voltage droop controller for a distributed power source; Indicates the first The reactive power of a distributed power source; This represents the voltage deviation value in an actual microgrid.

[0079] Step 1.5: Design about The controller is as follows:

[0080] ;

[0081] in, and Represents parameters of a traditional PI controller; Represents the input of the microgrid system;

[0082] Step 1.6: Based on steps 1.2-1.5, the constructed microgrid model for remote areas in Northwest China is shown below:

[0083] ;

[0084] in, Representing the first in a microgrid The state variables of a distributed power source For the first The derivatives of the state variables of a distributed power source; Representing the The integral of the voltage deviation of a distributed power source; Representing the The product of the input integral of a distributed power source and the PI controller parameters; This represents disturbances caused by distributed generation in a microgrid. Representing the first in a microgrid The output variables of each distributed power source are also the system output voltages. State parameter matrix. Input parameter matrix Output parameter matrix and perturbation parameter matrix They are as follows:

[0085] , , , ;

[0086] in, , These are the parameters of the PI controller; For auxiliary matrix, Indicates the first The droop gain of the voltage droop controller for a distributed power source; auxiliary matrix of state parameters. Input parameter auxiliary matrix Output parameter auxiliary matrix As shown below:

[0087] ;

[0088] Step 2: For novel power electronic converters in islanded microgrids, a new power and information dual composite modulation strategy that can "communicate" is proposed.

[0089] In the remote Northwest region, due to its vast territory, constructing communication lines is typically very difficult, and communication is often highly unstable, while also increasing the financial burden on local governments. To address these challenging issues, a novel dual-modulation strategy for power and information that enables "communication" was designed.

[0090] Step 2.1: Use a fixed duty cycle power converter and select two degrees of freedom: switching frequency and initial phase.

[0091] Step 2.2: Select a switching frequency of... The data carrier frequency is In actual engineering, the data carrier frequency is selected to be between 1 / 50 and 1 / 5 of the switching frequency.

[0092] Step 2.3: Modulate the data onto a low-frequency data carrier, and then modulate it onto a power carrier using PWM; then, set the system's output voltage as the target signal, modulate the data into an output voltage ripple, and transmit it through the power line;

[0093] Step 2.4: Use Orthogonal Frequency Division Multiplexing (OFDM) to achieve data reception and transmission through signal modulation and demodulation;

[0094] In this embodiment, as shown Figure 2 As shown, the specific steps include: first, performing serial-to-parallel data conversion: serial baseband data is sequentially converted into four sets of parallel baseband data, and then distributed to four channel subcarriers; then, each carrier is modulated based on the dual-carrier differential phase shift keying method.

[0095] An OFDM system consisting of N subcarrier signals can be represented by its communication carrier and each subcarrier as follows:

[0096] ;

[0097] ;

[0098] in, For communication carrier; For the first Road communication subcarrier; For the first The amplitude of the sinusoidal wave of the subcarrier in the communication path; For the first The carrier frequency of the communication subcarrier; For the first The sinusoidal phase of the communication subcarrier.

[0099] To achieve orthogonal frequency division multiplexing, the requirements of each communication subcarrier must be met. carrier frequency They are mutually orthogonal according to the following formula.

[0100] ;

[0101] in, ,and ; The symbol period is given. Therefore, the frequencies of each subcarrier can be obtained. satisfy:

[0102] , It is a positive integer;

[0103] Phase of a sine wave and baseband data The relationship satisfies the following formula: the phase difference between the current symbol period and the carrier of the previous symbol period is determined by the data.

[0104] ;

[0105] When a serial data segment consisting of 16 quaternion codes "0132 1320 3120 1302" is transmitted, it is then converted into modulation for each subcarrier. The baseband data transmitted on the third channel subcarrier is "3120". Within each symbol period, each quaternion data segment is converted into a continuous set of sine waves. Simultaneously, the phase difference between each set of sine waves and the previous set is... ;

[0106] The information receiving converter detects the voltage ripple at the microgrid bus port and retains the signal within the communication band after passing it through a bandpass filter. Ignoring noise, the resulting signal and each subcarrier are shown below:

[0107] ;

[0108] ;

[0109] in, To receive communication carriers; For the first The path receives communication subcarriers; For the first The amplitude of the sinusoidal wave received by the communication subcarrier; For the first The path receives the sinusoidal phase of the communication subcarrier.

[0110] Based on the orthogonality of trigonometric functions, within a certain symbol period, the first trigonometric function can be obtained from the signal of that symbol period. co-directional components of the subcarrier and orthogonal components They are respectively:

[0111] ;

[0112] in, For the first The amplitude of the sinusoidal wave received by the communication subcarrier; For the first The carrier frequency of the communication subcarrier; For the first The path receives the sinusoidal phase of the communication subcarrier.

[0113] Then the first symbol within that symbol period can be demodulated. Received communication subcarrier sine wave phase:

[0114] ;

[0115] Based on the relationship between the demodulated phase and the phase of the sine wave and the baseband data, the data within that symbol period can be demodulated. Then, by performing an inverse parallel-to-serial conversion on all received subcarrier data, the required data can be decoded.

[0116] Step 3: Incorporate the actual data transmission delay issue into the system modeling, and construct a microgrid physical model that takes into account the actual data transmission delay; thus, it is closer to the requirements of actual engineering.

[0117] When using this new "communication" method in microgrids in remote areas, the slower transmission rate will cause a certain degree of latency to the system, which is a factor that must be taken into account.

[0118] Specifically, serial data is emitted through continuous harmonics to calculate the delay time, thereby obtaining a microgrid physical model that takes into account the actual data transmission delay.

[0119] The physical model of the microgrid is as follows:

[0120] ;

[0121] in, Represents the state error of the microgrid system; Distributed power sources representing neighbors; This represents the input time delay in the system and satisfies... ; Represents the number of neighboring distributed power sources; It is a vector that can be known based on the actual set voltage.

[0122] In this embodiment, 16 quaternary serial data are emitted every 50 consecutive harmonics. The serial data represents the transmitted output voltage signal. The calculated delay time is 0.01s. The delay time of different distributed power supply units is different, but the order of magnitude is the same.

[0123] Step 4: Design a corresponding dynamic voltage coordination controller to obtain the ideal voltage, based on the voltage quality requirements of the actual microgrid;

[0124] Voltage stability is a key factor in assessing the stability of microgrids in remote mountainous areas. The required voltage level for a microgrid will vary depending on the application scenario, but the actual voltage quality should be controlled within a certain range. To achieve coordination and stability among multiple distributed power units, a corresponding controller needs to be designed to accomplish the goal when using a novel modulation strategy that can "communicate".

[0125] Step 4.1: Based on the physical model of a remote mountain microgrid with actual input delay, the output voltage control problem is transformed into a problem of consistency or inclusion of the output of a multi-agent system, thereby designing a corresponding dynamic cooperative output feedback controller;

[0126] For microgrids that are single-bus systems, a corresponding dynamic cooperative output feedback controller is designed as follows:

[0127] ;

[0128] in, and It is the control gain, a matrix obtained by solving based on the power system parameters and LMI; It is the state vector estimated for the power system; It is the first A dynamic observer for a distributed power source; This represents the number of distributed power sources.

[0129] Step 4.2: The designed power system state estimator is shown below:

[0130] ;

[0131] Step 4.3: Based on multi-agent graph theory, design the first... A dynamic observer for a distributed power source is shown below:

[0132] ;

[0133] in, , Representing the Dynamic observation vectors of a distributed power source; It is a positive number; Represents a known matrix; Represents the adjacency matrix in multi-agent graph theory; This represents the leader adjacency matrix in multi-agent graph theory. It connects the units of a distributed power source, and through a designed communication method, it can obtain information about its neighbors via circuit lines, thereby dynamically maintaining the stability of the bus voltage.

[0134] Step 4.4: Calculate the unknown state matrix according to the following formula. :

[0135] ;

[0136] Step 4.5: Calculate the unknown state matrix according to the following formula. :

[0137] ;

[0138] Step 4.6: Based on the calculated matrix and The positive definite matrix is ​​obtained by using LMI. Then, the control gain is obtained according to the following formula. and :

[0139] ;

[0140] Step 4.7: Use the designed power and information dual composite modulation strategy, as well as the dynamic cooperative output feedback controller, to make the output voltage of each distributed power unit consistent and maintain the stability of the power system bus voltage.

[0141] Step 4.8: Set the voltage deviation value The voltage reference value is obtained by feeding it into the voltage droop controller. Then, the voltage is obtained by the "plug-and-play" controller designed in step 1.5. After PWM modulation, the duty cycle required by the power electronic controller is obtained, and finally, intelligent voltage control of the microgrid in remote areas is realized in the case of "no communication".

[0142] In this embodiment, further precise control and adjustment are implemented to achieve intelligent management and control of the voltage in the microgrid.

[0143] To compensate for deviations in the system bus voltage and keep it within the standard range, a proportional-integral controller was designed as follows:

[0144] ;

[0145] in, and The control gain of the designed proportional-integral controller.

[0146] The voltage deviation value obtained above is fed into the voltage droop controller to obtain the voltage reference value. Then, the voltage obtained through the designed "plug-and-play" controller is further modulated by PWM to obtain the duty cycle required by the power electronic controller. Ultimately, intelligent voltage control of microgrids in remote areas is achieved in the absence of communication.

[0147] In this embodiment, as shown Figure 3 As shown, this illustrates the power and data harmonics of the power / information dual composite modulation strategy in this embodiment. The power harmonics are generated by the power electronic devices themselves, while the data harmonics carry the transmission voltage. This enables simultaneous power and data transmission. The output voltages of each distributed power unit in the microgrid system are as follows: Figure 4 As shown, the output voltage can achieve consistency, verifying the effectiveness of the proposed method.

[0148] Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a computer program product.

[0149] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0150] The scope of protection of this application is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from the scope and spirit of this disclosure. If such modifications and variations fall within the scope of the methods disclosed herein and their equivalents, then the intent of this disclosure also includes such modifications and variations.

Claims

1. A method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy, characterized in that, Includes the following steps: Step 1: Design the microgrid model; Step 2: For novel power electronic converters in islanded microgrids, a dual composite modulation strategy for power and information is proposed; Step 3: Incorporate the data transmission delay issue into the system modeling and construct a microgrid physical model that takes into account the actual data transmission delay. Specifically, serial data is transmitted through continuous harmonics to calculate the delay time, thus obtaining the microgrid physical model that takes into account the actual data transmission delay. Step 4: Design a corresponding dynamic voltage coordination controller to meet the voltage quality requirements of the actual microgrid and realize intelligent control of the microgrid model.

2. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 1, characterized in that, Step 1 specifically includes the following steps: Step 1.1: Construct the overall framework of the microgrid physical model; specifically, construct a DC bus, connect it to a bidirectional DC / DC converter, and connect all users and public facilities to it; Step 1.2: Establish a physical model of the islanded microgrid based on Kirchhoff's current and voltage laws, and obtain the following relationship: ； in, , and These are the resistors, inductors, and capacitors that make up the filter. It is the capacitor voltage. It is the output voltage of the power electronic converter; It is inductor current. It is a regional load; Step 1.3: Design the voltage controller; The voltage controller is shown below: ； in, , and It is the voltage proportional-integral controller coefficient in the design; This is the voltage reference value; Step 1.4: Design a voltage droop controller to achieve voltage management by simulating the characteristics of a synchronous generator; The voltage droop controller is shown below: ； in, Indicates the rated bus voltage; Indicates the first The droop gain of a voltage droop controller for a distributed power source; Indicates the first The reactive power of a distributed power source; This represents the voltage deviation value in an actual microgrid; Step 1.5: Design about The controller is as follows: ； in, and Represents parameters of a traditional PI controller; Represents the input of the microgrid system; Step 1.6: Based on steps 1.2-1.5, the constructed microgrid model is shown below: ； in, Representing the first in a microgrid The state variables of a distributed power source For the first The derivatives of the state variables of a distributed power source; Representing the The integral of the voltage deviation of a distributed power source; Representing the The product of the input integral of a distributed power source and the PI controller parameters; This represents disturbances caused by distributed generation in a microgrid. Representing the first in a microgrid The output variables of each distributed power source are also the system output voltage; state parameter matrix Input parameter matrix Output parameter matrix and perturbation parameter matrix They are as follows: ， ， ， ； in, , These are the parameters of the PI controller; For auxiliary matrix, Indicates the first The droop gain of the voltage droop controller for a distributed power source; auxiliary matrix of state parameters. Input parameter auxiliary matrix Output parameter auxiliary matrix As shown below: ， 。 3. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 2, characterized in that, Step 2 specifically includes the following steps: Step 2.1: Use a fixed duty cycle power converter and select two degrees of freedom: switching frequency and initial phase; Step 2.2: Select a switching frequency of... The data carrier frequency is ; Step 2.3: Modulate the data onto a low-frequency data carrier, and then modulate it onto a power carrier using PWM; then, set the system's output voltage as the target signal, modulate the data into an output voltage ripple, and transmit it through the power line; Step 2.4: Use Orthogonal Frequency Division Multiplexing (OFDM) to achieve data reception and transmission through signal modulation and demodulation; Specifically, this includes: first, performing serial-to-parallel data conversion: serial baseband data is sequentially converted into four sets of parallel baseband data, and then distributed to four channel subcarriers; then, each carrier is modulated based on the dual-carrier differential phase shift keying method.

4. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 3, characterized in that, The microgrid physical model described in step 3 is as follows: ； in, Represents the state error of the microgrid system; Distributed power sources representing neighbors; This represents the input time delay in the system and satisfies... ; Represents the number of neighboring distributed power sources; It is a vector that can be known based on the actual set voltage.

5. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 4, characterized in that, Step 4 specifically includes the following steps: Step 4.1: Based on the physical model of the microgrid with actual input delay, the output voltage control problem is transformed into a problem of consistency or inclusion of the output of a multi-agent system, so as to design a corresponding dynamic cooperative output feedback controller; Step 4.2: The designed power system state estimator is shown below: ； Step 4.3: Based on multi-agent graph theory, design the first... A dynamic observer for a distributed power source; Step 4.4: Calculate the unknown state matrix according to the following formula. : ； Step 4.5: Calculate the unknown state matrix according to the following formula. : ； Step 4.6: Based on the calculated matrix and The positive definite matrix is ​​obtained by using LMI. Then, the control gain is obtained according to the following formula. and : ； Step 4.7: Use the designed power and information dual composite modulation strategy, as well as the dynamic cooperative output feedback controller, to make the output voltage of each distributed power unit consistent and maintain the stability of the power system bus voltage; Step 4.8: Set the voltage deviation value The voltage reference value is obtained by feeding it into the voltage droop controller. Then, based on the voltage obtained by the controller, the duty cycle required by the power electronic controller is obtained through PWM modulation, thus realizing intelligent voltage control in the absence of communication.

6. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 5, characterized in that, In step 4.1, for the case where the microgrid is a single-bus system, the corresponding dynamic cooperative output feedback controller is designed as follows: ； in, and It is about controlling the gain. It is the state vector estimated for the power system; It is the first A dynamic observer for a distributed power source; This represents the number of distributed power sources.

7. The method for intelligent voltage control of remote microgrids based on a dual power and information modulation strategy according to claim 6, characterized in that, In step 4.3, the first The dynamic observer for a distributed power source is shown below: ； in, , Representing the Dynamic observation vectors of a distributed power source; It is a positive number; Represents a known matrix; Represents the adjacency matrix in multi-agent graph theory; This represents the leader adjacency matrix in multi-agent graph theory.

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