Microgrid power control method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to a micro-grid power control method and device, computer equipment, a readable storage medium and a program product, and relates to the technical field of micro-grid control, and the method comprises the steps: obtaining the working parameters of each distributed power supply of a micro-grid, so as to determine the initial active power and reactive power of each distributed power supply; determining a first output frequency based on the first active power droop coefficient and the initial active power corresponding to each distributed power supply, and determining a first output voltage based on the corresponding first reactive power droop coefficient and the initial reactive power; adjusting and controlling the amplitude and the phase of the impedance of the line resistor between each distributed power supply and the common connection point, monitoring the active power change value and the reactive power change value, determining the corresponding second active and reactive power droop coefficients, and further determining the second output frequency and the output voltage corresponding to each distributed power supply; and target active power and reactive power corresponding to each distributed power supply are determined based on the second output frequency and the output voltage, so that stable operation of the micro-grid is controlled.

Description

Technical Field

[0001] The present application relates to the field of microgrid control technology, and in particular to a microgrid power control method, apparatus, computer equipment, readable storage medium, and program product. Background Art

[0002] With the profound transformation of the global energy structure, the efficient integration and utilization of distributed renewable energy has become an important development direction for modern power systems. As an independently operating local power network, the island microgrid can provide continuous power guarantee for critical loads in the event of a main grid failure or power outage. Its flexible on-grid and off-grid switching capabilities and efficient energy management features have shown significant advantages in power supply in remote areas, emergency disaster relief, and high-proportion renewable energy consumption scenarios. However, the stable operation of the island microgrid is highly dependent on the coordinated power distribution among distributed power sources. If the power distribution is unbalanced, it will not only cause some equipment to overload, but also disrupt the system supply and demand balance, causing voltage fluctuations, frequency drift, and harmonic pollution, seriously threatening the normal operation of sensitive equipment.

[0003] Therefore, it is urgent to provide a method for coordinating power distribution among distributed power sources for the operation of an island microgrid. Summary of the Invention

[0004] Based on this, it is necessary to provide a microgrid power control method, device, computer equipment, computer-readable storage medium and computer program product that can effectively control the power between distributed power sources in the operation of an isolated microgrid in order to solve the above technical problems.

[0005] In a first aspect, the present application provides a microgrid power control method, the method comprising:

[0006] Obtaining operating parameters of preselected types of distributed power sources in the microgrid during the current period, and determining initial active power and initial reactive power of each of the distributed power sources based on the operating parameters;

[0007] Obtaining a first active power droop coefficient and a first reactive power droop coefficient corresponding to each of the distributed power sources, and determining a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each of the distributed power sources, and determining a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each of the distributed power sources;

[0008] Regulating the amplitude and phase of the line impedance between each of the distributed power sources and the corresponding common connection point, and monitoring the active power change value and the reactive power change value of each of the distributed power sources to determine a second active power droop coefficient corresponding to each of the first active power droop coefficients, and a second reactive power droop coefficient corresponding to each of the first reactive power droop coefficients;

[0009] Determining a second output frequency and a second output voltage corresponding to each of the distributed power sources based on each of the second active power droop coefficients and each of the second reactive power droop coefficients, and determining a target active power and a target reactive power corresponding to each of the distributed power sources based on the second output frequency and the second output voltage;

[0010] The operation of the microgrid is controlled by the target active power and the target reactive power.

[0011] In one embodiment, the method further comprises:

[0012] Obtain the current output frequency of each distributed power source in the microgrid, as well as the corresponding reference frequency and reference active power;

[0013] Determining the corresponding first active power droop coefficient based on the current output frequency, reference frequency, reference active power and initial active power of each of the distributed power sources;

[0014] Obtaining a current maximum output current value of a load electrically connected to each of the distributed power sources, as well as an initial value of a line impedance, a reference reactive power, a reference voltage, and a current output voltage corresponding to each of the distributed power sources;

[0015] Based on the current maximum output current value of each distributed power source, the initial value of the line impedance, the reference reactive power, the reference voltage, the current output voltage and the initial reactive power, the corresponding first reactive power droop coefficient is determined.

[0016] In one embodiment, the method further comprises:

[0017] Obtaining the line inductance between each of the distributed power sources and the corresponding common connection point, and the current output voltage of each distributed power source;

[0018] The reference voltage is determined based on the line inductance, the current output voltage, and the initial reactive power of each of the distributed power sources.

[0019] In one embodiment, the method further comprises:

[0020] Based on the preset positive-sequence resistance, positive-sequence inductance, positive-sequence current group, negative-sequence resistance, negative-sequence inductance, negative-sequence current group, harmonic resistance of the h-th harmonic component, harmonic inductance of the h-th harmonic component, harmonic current group of the h-th harmonic component, the angular frequency of the microgrid and the angle operator associated with the positive-sequence current group, the amplitude of the line resistance impedance used to regulate each of the distributed power sources is determined; h is a positive integer.

[0021] In one embodiment, the method further comprises:

[0022] Obtaining a first proportional coefficient of the voltage controller corresponding to each of the distributed power sources, a first harmonic coefficient for the hth harmonic component, and a second proportional coefficient of the corresponding current controller, a second harmonic coefficient for the hth harmonic component, and obtaining a preset cutoff frequency, pi, fundamental frequency, value of h, and Laplace operator;

[0023] Modeling a voltage resonance controller based on the first proportional coefficient, the first harmonic coefficient, the cutoff frequency, the pi, the fundamental frequency, the value of h, and the Laplace operator corresponding to each of the distributed power sources;

[0024] Modeling a current resonant controller based on the second proportional coefficient, the second harmonic coefficient, the cutoff frequency, the pi, the fundamental frequency, the value of h, and the Laplace operator corresponding to each of the distributed power sources;

[0025] The resonant frequency corresponding to each of the hth harmonics is determined based on the voltage resonant controller and the current resonant controller.

[0026] In one embodiment, obtaining operating parameters of preselected types of distributed power sources in the microgrid during the current period, and determining initial active power and initial reactive power of each distributed power source based on the operating parameters, includes:

[0027] The output voltage data and the output current data of each distributed power source in the microgrid in the current period are obtained, so as to determine the initial active power and the initial reactive power of each distributed power source based on the output voltage data and the output current data.

[0028] In a second aspect, the present application further provides a microgrid power control device, the device comprising:

[0029] A parameter acquisition module is used to obtain the operating parameters of the preselected types of distributed power sources in the microgrid during the current period, and determine the initial active power and initial reactive power of each of the distributed power sources based on the operating parameters;

[0030] a data processing module, configured to obtain a first active power droop coefficient and a first reactive power droop coefficient corresponding to each of the distributed power sources, and determine a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each of the distributed power sources, and determine a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each of the distributed power sources;

[0031] an impedance adjustment module, configured to regulate the amplitude and phase of the line impedance between each of the distributed power sources and the corresponding common connection point, and monitor the active power change value and the reactive power change value of each of the distributed power sources to determine a second active power droop coefficient corresponding to each of the first active power droop coefficients, and a second reactive power droop coefficient corresponding to each of the first reactive power droop coefficients;

[0032] a target parameter determination module, configured to determine a second output frequency and a second output voltage corresponding to each of the distributed power sources based on each of the second active power droop coefficients and each of the second reactive power droop coefficients, and determine a target active power and a target reactive power corresponding to each of the distributed power sources based on the second output frequency and the second output voltage;

[0033] An operation control module is used to control the operation of the microgrid through each of the target active powers and each of the target reactive powers.

[0034] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in the first aspect when executing the computer program.

[0035] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the steps in the first aspect when executed by a processor.

[0036] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements the steps in the first aspect when executed by a processor.

[0037] In the microgrid power control method, device, computer equipment, computer-readable storage medium and computer program product provided by the above-mentioned application, the microgrid power control method obtains the operating parameters of the preselected types of each distributed power source in the current period in the microgrid, and determines the initial active power and initial reactive power of each distributed power source based on the operating parameters; obtains the first active power droop coefficient and the first reactive power droop coefficient corresponding to each distributed power source, and determines the corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each distributed power source, and determines the corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each distributed power source; regulates the amplitude and phase of the line impedance between each distributed power source and the corresponding common connection point, and monitors the active power change value of each distributed power source. and reactive power change values to determine the second active power droop coefficient corresponding to each first active power droop coefficient, and the second reactive power droop coefficient corresponding to each first reactive power droop coefficient, so that dynamic adjustment of the active power droop coefficient and the reactive power droop coefficient can be achieved; based on each second active power droop coefficient and each second reactive power droop coefficient, the second output frequency and the second output voltage corresponding to each distributed power source are determined, and based on the second output frequency and the second output voltage, the target active power and the target reactive power corresponding to each distributed power source are determined, that is, dynamic adjustment of the active power and reactive power of each distributed power source is achieved. Finally, the operation of each distributed power source in the microgrid is controlled by the target active power and the target reactive power corresponding to each distributed power source, which is conducive to ensuring the continuous and stable operation of the microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 2. A diagram showing an application environment of a microgrid power control method according to an embodiment;

[0040] Figure 2 1 is a flow chart of a microgrid power control method according to an embodiment;

[0041] Figure 3 Schematic diagram of a flow chart of a microgrid power control method according to another embodiment;

[0042] Figure 4 FIG1 is an experimental diagram of a microgrid power control method in one embodiment;

[0043] Figure 5 is a structural block diagram of a microgrid power control device in one embodiment;

[0044] Figure 6 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0046] It should be noted that the terms "first", "second", etc. used in this application may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "including" and "having" used in this application and any variations thereof are intended to cover non-exclusive inclusions. The term "plurality" used in this application refers to two or more. The term "and / or" used in this application refers to one of the solutions or any combination of multiple solutions.

[0047] Traditional island microgrids often use a droop control strategy to achieve power distribution. This approach establishes a voltage / frequency and power droop characteristic curve, enabling each inverter to dynamically adjust its reference voltage based on real-time power, thereby achieving equal power distribution. While droop control offers the advantages of requiring no communication and responsiveness, its inherent drawbacks are particularly pronounced under complex operating conditions. First, variations in line impedance can distort power distribution accuracy. Because the resistance and reactance of actual lines are significantly affected by the routing, material, and load type, the traditional droop control assumption that power is proportional to impedance is untenable. Second, nonlinear loads and single-phase unbalanced loads generate harmonic currents and negative-sequence components. Traditional droop control, based solely on fundamental power calculations, cannot effectively compensate for these harmonics and negative-sequence power, leading to excessive harmonic distortion and even localized voltage violations or equipment failures. Furthermore, the power distribution results of droop control are susceptible to sudden load changes and frequency fluctuations, potentially causing transient power oscillations during the dynamic response process, exacerbating the risk of system instability.

[0048] In summary, power distribution technology for island microgrids still faces multiple challenges, including line impedance mismatch, insufficient harmonic suppression, and strong communication dependency. A new control scheme that combines speed, robustness, and cost-effectiveness is urgently needed to address issues such as inverter power distribution imbalance, circulating current losses caused by line impedance differences, voltage and frequency instability caused by nonlinear loads, and harmonic pollution in island microgrids.

[0049] Based on this, it is necessary to provide a microgrid power control method that can solve the relevant technical problems in response to the above technical problems, specifically including obtaining the working parameters of the preselected types of each distributed power source in the current period in the microgrid, and determining the initial active power and initial reactive power of each distributed power source based on the working parameters; obtaining the first active power droop coefficient and the first reactive power droop coefficient corresponding to each distributed power source, and determining the corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each distributed power source, and determining the corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each distributed power source; regulating the voltage between each distributed power source and the corresponding common connection point The amplitude and phase of the line resistance impedance are measured, and the active power change value and the reactive power change value of each distributed power source are monitored to determine the second active power droop coefficient corresponding to each first active power droop coefficient, and the second reactive power droop coefficient corresponding to each first reactive power droop coefficient; based on each second active power droop coefficient and each second reactive power droop coefficient, the second output frequency and the second output voltage corresponding to each distributed power source are determined, and based on the second output frequency and the second output voltage, the target active power and the target reactive power corresponding to each distributed power source are determined, and the operation of each distributed power source in the microgrid is controlled by the target active power and the target reactive power corresponding to each distributed power source, thereby ensuring the stable operation of the microgrid.

[0050] The microgrid power control method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. The terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The data storage system can be used to store, for example, relevant operating parameters of each distributed power source during operation, such as relevant output voltage, output current, output frequency and other parameters. The terminal 102 can be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, etc., and specifically, for example, a microgrid control terminal. The server 104 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services.

[0051] In an exemplary embodiment, Figure 2 As shown, a microgrid power control method is provided, which is applied to Figure 1 The terminal 102 in the example is used as an example to illustrate the process, including the following steps 201 to 205. Among them:

[0052] Step 201: Obtain operating parameters of preselected types of distributed power sources in the microgrid during the current period, and determine initial active power and initial reactive power of each distributed power source based on the operating parameters.

[0053] The current time period may be based on the current operating time of the microgrid and at least the previous operating time corresponding to the current operating time.

[0054] The operating parameters may be determined based on preselected types, such as current, voltage, and frequency. The acquired operating parameters for each distributed power source during the current time period may include multiple parameters corresponding to multiple time periods for each type, and there is no limitation on a single number of parameters of a given type. Because the operating parameters are subsequently used to determine at least the initial active power and initial reactive power of each distributed power source, the type of operating parameter may be determined based on the need to determine the initial active power and initial reactive power.

[0055] Exemplarily, at least operating parameters that can be used to determine the initial active power and initial reactive power of each distributed power source can be obtained to achieve the determination of the initial active power and initial reactive power of each distributed power source in the microgrid.

[0056] Step 202: Obtain a first active power droop coefficient and a first reactive power droop coefficient corresponding to each distributed power source, and determine a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each distributed power source, and determine a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each distributed power source.

[0057] The first active power droop coefficient and the first reactive power droop coefficient can be implemented based on the relevant droop coefficient determination formulas provided later in this application. The first output frequency and the first output voltage can also be implemented based on the relevant output frequency and voltage determination formulas provided later in this application. For related details, please refer to the following.

[0058] For example, after determining the initial active power and initial reactive power of each distributed power source by executing step 201, the first active power droop coefficient and the first reactive power droop coefficient corresponding to each distributed power source can be further combined to determine the first output frequency and the first output voltage corresponding to each distributed power source through relevant calculation methods.

[0059] Step 203: Regulate the amplitude and phase of the line impedance between each distributed power source and the corresponding common connection point, and monitor the active power change value and reactive power change value of each distributed power source to determine the second active power droop coefficient corresponding to each first active power droop coefficient, and the second reactive power droop coefficient corresponding to each first reactive power droop coefficient.

[0060] Among them, the public connection point refers to the connection point where the user system (power generation or consumption) is connected to the public power grid; it is usually the first point of access to the network after the grid connection point, involving the connection of multiple customers.

[0061] The magnitude and phase of impedance are important parameters that describe the relationship between current and voltage in AC circuits. The magnitude of impedance (|Z|) can be calculated using the formula: |Z|=√(R²+X²), where R is resistance and X is reactance (the impedance of an inductor or capacitor). The phase angle (φ) is calculated using the formula φ=atan(X / R), which represents the phase difference between current and voltage. It should be noted that both the magnitude and phase of impedance are frequency-dependent.

[0062] Exemplarily, by dynamically adjusting the amplitude and phase of the line impedance between each distributed power source and the corresponding common connection point based on demand, while continuously monitoring the active power change value and reactive power change value of each distributed power source, then based on the relevant output frequency and voltage determination formula provided later in this application, by monitoring the active power and reactive power and other parameters of each distributed power source, the first active power droop coefficient of each distributed power source can be updated to obtain the related second active power droop coefficient, and the first reactive power droop coefficient of each distributed power source can be updated to obtain the corresponding second reactive power droop coefficient.

[0063] That is, the above method can realize the dynamic update of the active power droop coefficient and the reactive power droop coefficient.

[0064] Step 204: Determine the second output frequency and the second output voltage corresponding to each distributed power source based on each second active power droop coefficient and each second reactive power droop coefficient, and determine the target active power and the target reactive power corresponding to each distributed power source based on the second output frequency and the second output voltage.

[0065] For example, when the updated active power droop coefficient and reactive power droop coefficient corresponding to each distributed power source are obtained, the updated output frequency and output voltage corresponding to each distributed power source can be further obtained based on the relevant output frequency and voltage determination formula provided later in this application, and the updated target active power and target reactive power corresponding to each distributed power source can be determined based on the updated output frequency and output voltage, thereby realizing the supply update of the active power and reactive power corresponding to each distributed power source, thereby realizing the dynamic correction of the working power of each distributed power source, so as to improve the operating stability of the microgrid including the relevant distributed power sources.

[0066] Step 205 : Control the operation of the microgrid by using the target active power and the target reactive power.

[0067] Specifically, the operation of each distributed power source in the microgrid is controlled by the target active power and target reactive power corresponding to each distributed power source, thereby realizing the operation control of the microgrid, which is conducive to ensuring the continuous and stable operation of the microgrid.

[0068] In the above-mentioned microgrid power control method, the operating parameters of the preselected types of distributed power sources in the current period of the microgrid are obtained, and the initial active power and initial reactive power of each distributed power source are determined based on the operating parameters; the first active power droop coefficient and the first reactive power droop coefficient corresponding to each distributed power source are obtained, and the corresponding first output frequency is determined based on the first active power droop coefficient and the initial active power corresponding to each distributed power source, and the corresponding first output voltage is determined based on the first reactive power droop coefficient and the initial reactive power corresponding to each distributed power source; the amplitude and phase of the line resistance impedance between each distributed power source and the corresponding common connection point are regulated, and the active power change value and reactive power change value of each distributed power source are monitored to determine each first active power droop The second active power droop coefficient corresponding to the first reactive power droop coefficient and the second reactive power droop coefficient corresponding to each first reactive power droop coefficient are determined. In this way, dynamic adjustment of the active power droop coefficient and the reactive power droop coefficient can be achieved. Based on each second active power droop coefficient and each second reactive power droop coefficient, the second output frequency and the second output voltage corresponding to each distributed power source are determined, and based on the second output frequency and the second output voltage, the target active power and the target reactive power corresponding to each distributed power source are determined, that is, dynamic adjustment of the active power and the reactive power of each distributed power source is achieved. Finally, the operation of each distributed power source in the microgrid is controlled by the target active power and the target reactive power corresponding to each distributed power source, which is conducive to ensuring the continuous and stable operation of the microgrid.

[0069] In an exemplary embodiment, the microgrid power control method provided in the present application also includes: obtaining the current output frequency of each distributed power source in the microgrid, as well as the corresponding reference frequency and reference active power; based on the current output frequency, reference frequency, reference active power and initial active power of each distributed power source, determining the corresponding first active power droop coefficient.

[0070] For example, the first active power droop coefficient corresponding to each distributed power source can be based on the formula The calculation is performed, and the four data after the equal sign in the formula can be the reference frequency, the current output frequency, the reference active power and the initial active power in sequence, so as to realize the calculation of the first active power droop coefficient.

[0071] Among them, each distributed power source can be pre-set with a different reference frequency and reference active power, and the current output frequency and initial active power of each distributed power source can be obtained based on the monitored operating parameters, or obtained by performing relevant operations on the monitored operating parameters.

[0072] In an exemplary embodiment, the microgrid power control method provided in the present application also includes: obtaining the current maximum output current value of the load electrically connected to each distributed power source, as well as the initial value of the line resistance impedance, reference reactive power, reference voltage and current output voltage corresponding to each distributed power source; based on the current maximum output current value, initial value of the line resistance impedance, reference reactive power, reference voltage, current output voltage and initial reactive power of each distributed power source, determining the corresponding first reactive power droop coefficient.

[0073] For example, the first reactive power droop coefficient corresponding to each distributed power source can be based on the formula To calculate, the six data after the equal sign in the formula can be the reference voltage, current output voltage, current maximum output current value, initial value of line impedance, reference reactive power and initial reactive power; among them, Specifically, it refers to the maximum load current connected to each distributed power source.

[0074] Among them, each distributed power supply can be pre-set with a different reference voltage and reference reactive power, and the current output voltage, current maximum output current value, line impedance initial value and initial reactive power of each distributed power supply can be obtained based on monitoring working parameters and performing related calculations.

[0075] In an exemplary embodiment, the microgrid power control method provided in the present application also includes: obtaining the line inductance between each distributed power source and the corresponding common connection point, and the current output voltage of each distributed power source; determining the reference voltage based on the line inductance, current output voltage and initial reactive power of each distributed power source.

[0076] For example, the formula for determining the reference voltage may be: , where the three data after the equal sign can be the initial reactive power of each distributed power source, the line inductance between the distributed power source and the corresponding public connection point, and the current output voltage.

[0077] The line inductance between the distributed power source and the corresponding common connection point can be obtained by detecting the inductance of the relevant line resistance. The initial reactive power and the current output voltage can be obtained by monitoring the operating parameters and performing relevant calculations.

[0078] In an exemplary embodiment, the microgrid power control method provided herein further includes determining the magnitude of the line impedance used to control each distributed power source based on preset positive-sequence resistance, positive-sequence inductance, positive-sequence current group, negative-sequence resistance, negative-sequence inductance, negative-sequence current group, the harmonic resistance of the hth harmonic component, the harmonic inductance of the hth harmonic component, the harmonic current group of the hth harmonic component, the angular frequency of the microgrid, and an angle operator (hereinafter referred to as j) associated with the positive-sequence current group; h is a positive integer. The value of h can be, for example, 1, 5, 7, etc., and is not specifically limited in this application.

[0079] For example, the technical solution to be described here is to reduce harmonics and distribute circulating currents between distributed generation units through virtual impedance. The relationship between the voltage of the virtual impedance and the impedance components of the positive sequence, negative sequence and each harmonic is as follows:

[0080]

[0081] Where, 、 、( , ) represent the resistance, inductance and current in the positive-sequence, negative-sequence and h-th harmonic components respectively (i.e. corresponding to the positive-sequence resistance, positive-sequence inductance, positive-sequence current group, negative-sequence resistance, negative-sequence inductance, negative-sequence current group, harmonic resistance of h-th harmonic component, harmonic inductance of h-th harmonic component, and harmonic current group of h-th harmonic component mentioned above), It is the angular frequency, specifically refers to the fundamental angular frequency of the entire microgrid system. represents the voltage of the virtual impedance, and the subscripts α and β represent the components of the voltage and current on the α and β axes. j is the imaginary unit, which is equivalent to an operator rotated 90°. α and β are orthogonal, and the angular relationship between them is shown here. The "+" represents "positive sequence" and the "-" represents "negative sequence".

[0082] In an exemplary embodiment, the microgrid power control method provided in the present application also includes: obtaining the first proportional coefficient of the voltage controller corresponding to each distributed power source, the first harmonic coefficient of the h-th harmonic component, and the second proportional coefficient of the corresponding current controller, the second harmonic coefficient of the h-th harmonic component, and obtaining the preset cutoff frequency, pi, fundamental frequency, h value and Laplace operator; based on the first proportional coefficient, first harmonic coefficient, cutoff frequency, pi, fundamental frequency, h value and Laplace operator corresponding to each distributed power source, modeling to form a voltage resonance controller; based on the second proportional coefficient, second harmonic coefficient, cutoff frequency, pi, fundamental frequency, h value and Laplace operator corresponding to each distributed power source, modeling to form a current resonance controller; determining the resonant frequency corresponding to each h-th harmonic based on the voltage resonance controller and the current resonance controller.

[0083] For example, the technical solution to be described here is to use a resonant controller and model the voltage resonant controller and the current resonant controller according to the following formula:

[0084]

[0085]

[0086] Where, and are the proportional coefficients of the voltage and current controllers (corresponding to the first and second proportional coefficients mentioned above), and are the coefficients of the voltage and current controllers for the h-order harmonic component (corresponding to the first harmonic coefficient and the second harmonic coefficient mentioned above), is the cutoff frequency, is pi, is the fundamental frequency, h is the harmonic number, and s is the Laplace operator.

[0087] In an exemplary embodiment, the microgrid power control method provided in the present application comprises: obtaining the operating parameters of the preselected types of each distributed power source in the current period in the microgrid, and determining the initial active power and initial reactive power of each distributed power source based on the operating parameters, including: obtaining the output voltage data and output current data of each distributed power source in the current period in the microgrid, and determining the initial active power and initial reactive power of each distributed power source based on the output voltage data and the output current data.

[0088] The microgrid power control method provided in this application is actually a microgrid power distribution control method suitable for island operation mode. It mainly improves the power distribution accuracy of distributed power sources in island microgrids by integrating droop control and virtual impedance hierarchical control method, suppresses harmonic distortion and circulating current problems caused by nonlinear loads, and enhances system voltage / frequency stability. The specific steps can be summarized as follows: Steps S1 to S3, please refer to Figure 3 .

[0089] S1: Real-time acquisition of output voltage and current signals of distributed power sources in the microgrid; specifically:

[0090] The output voltage, current, and frequency of each distributed generation unit within the microgrid are sampled in real time. The three-phase current is decomposed into positive and negative sequence components in the α-β stationary coordinate system (αβ coordinate system) using the Clarke Transformation. The main active and reactive power values are extracted after filtering out high-frequency noise with a low-pass filter. The αβ coordinate system is a two-phase stationary coordinate system used to represent voltages and currents in rotating electrical machines and power electronics systems, and is often used to simplify the analysis and control of three-phase systems. The αβ coordinate system is defined as: obtained by transforming the three-phase stationary coordinate system (ABC coordinate system); it consists of two orthogonal axes, the α-axis and the β-axis, with the α-axis typically coinciding with phase A. This coordinate system is introduced primarily to better represent and analyze space vectors in rotating electrical machines, particularly in motor control and power electronics applications, simplifying calculations and control strategy design.

[0091] S2: Primary control achieves precise power distribution of distributed power sources through droop control and dynamic impedance matching; specifically:

[0092] Based on the real-time collected power data, the droop control equation is used to generate the reference voltage and frequency of each distributed power source. At the same time, multi-sequence virtual impedance is introduced to actively compensate for line impedance differences and suppress circulating current and harmonic interference. The estimated value of the feeder voltage drop is superimposed on the reference voltage output end to correct the reactive power distribution deviation and ensure that power sources of different capacities share the load proportionally.

[0093] S3: The secondary control layer corrects voltage and frequency deviations; specifically:

[0094] The voltage amplitude and angular frequency at the common connection point are detected in real time, compared with the reference value, and then input into the PI controller to generate a compensation signal. The compensation signal is fed back to the primary control layer via a low-bandwidth communication link to dynamically correct the reference voltage and frequency of the droop controller, eliminate the accumulated deviation of the primary control, and achieve stable recovery of the voltage and frequency of the island microgrid.

[0095] Furthermore, in the above step S1, the collected data may include voltage, current and frequency, which are converted into the αβ coordinate system to obtain power by the following formula:

[0096]

[0097]

[0098] In the above formula, P and Q are active and reactive power in the reference coordinate system; 、 and 、 are the voltage and current corresponding to the αβ coordinate system respectively.

[0099] Among them, it needs to be explained that the core mechanism of droop control is to adjust the power output through frequency deviation, and the frequency can be used in droop control. and They are projections of the same phasor on different orthogonal axes. There is no physical independence and they are two data corresponding to a distributed power source.

[0100] Furthermore, in step S2, the power distribution adopts droop control, and its formula is:

[0101]

[0102]

[0103] The droop coefficient 、 Determined by the following formula:

[0104]

[0105]

[0106] Where, and is the droop coefficient, and are the output frequency and voltage, and are the reference frequency and voltage, and is the reference active power and reactive power, P and Q are the measured active power and reactive power, is the impedance of the positive imaginary sequence, The output current of the load specifically refers to the maximum load current connected to each distributed power source, and the subscript i represents different distributed power sources.

[0107] It should be explained that active power distribution mainly depends on frequency regulation, while virtual impedance has little effect on active power. The formula does not require additional compensation terms. The initial value of is determined by measuring the line impedance from the distributed generation to the PCC (Point of Common Coupling), and the amplitude and phase of the virtual impedance are adjusted according to the design requirements.

[0108] Furthermore, in step S2, the voltage drop is estimated by the following formula and incorporated into the voltage reference generation process of the droop controller to achieve voltage compensation:

[0109]

[0110] Where, is the voltage drop, Q is the reactive power, U1 is the inverter output voltage, X L It is the line inductance from the distributed generation to the PCC and can be measured.

[0111] It should be added that the voltage drop ΔV is estimated in real time and added to the voltage reference value of the droop controller (i.e. ) to correct the reactive power distribution error.

[0112] Furthermore, in step S2, harmonics are reduced and circulating currents between distributed generation units are distributed through virtual impedance. The relationship between the voltage of the virtual impedance and the impedance components of the positive sequence, negative sequence and each harmonic is as follows:

[0113]

[0114] Where, 、 、 、 Represent the resistance, inductance and current in the positive sequence, negative sequence and hth harmonic components respectively, It is the angular frequency, specifically refers to the fundamental angular frequency of the entire microgrid system. represents the voltage of the virtual impedance, and the subscripts α and β represent the components of the voltage and current on the α and β axes. j is the imaginary unit, which is equivalent to an operator rotated 90°. α and β are orthogonal, and the angular relationship between them is shown here. The "+" represents "positive sequence" and the "-" represents "negative sequence".

[0115] It's important to note that by simulating the equivalent positive-sequence impedance, the equivalent output impedance of each DG (Distributed Generation) is forced to be consistent, eliminating circulating currents caused by line impedance differences. By designing the impedance components of each harmonic, harmonic currents of specific frequencies are specifically suppressed.

[0116] Furthermore, in step S2, a resonant controller is used to model the voltage and current resonant controller according to the following equations:

[0117]

[0118]

[0119] Where, and are the proportional coefficients of the voltage and current controllers, respectively, and are the coefficients of the voltage and current controllers for the h-order harmonic components, is the cutoff frequency, is pi, is the fundamental frequency, h is the harmonic number, and s is the Laplace operator.

[0120] It should be added that by designing frequency bands for the h=1, 5, and 7 harmonics, the ability to regulate specific frequency harmonics is enhanced and the harmonic distortion rate is reduced.

[0121] like Figure 4 The experimental diagram of the microgrid power control method provided by the present application is shown. In the diagram, the capacity of DG1 (the first distributed power source) is twice that of DG2 (the second distributed power source), the load is a combination of nonlinear, time-varying and unbalanced loads, and the active power demand increases from 1.9 kW (kilowatt-hours) to 3.4 kW in 1 second. The method proposed in the present application can well distribute the active power between the power sources even in the case of sudden changes in nonlinear and unbalanced loads. Figure 4 The "W" in watt-hours stands for "watt-hours".

[0122] It can be seen that the microgrid power distribution control method suitable for island operation mode provided in this application is to improve the power distribution accuracy of distributed power sources in the island microgrid by integrating droop control and virtual impedance hierarchical control method, suppress harmonic distortion and circulating current problems caused by nonlinear loads, and enhance the system voltage / frequency stability.

[0123] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of the steps or stages in other steps or other steps. It is understandable that the various steps in different embodiments can be freely combined as needed, and the various non-contradictory schemes formed by the combination all fall within the scope of protection of this application.

[0124] Based on the same inventive concept, embodiments of the present application also provide a microgrid power control device for implementing the aforementioned microgrid power control method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more microgrid power control device embodiments provided below can be found in the above-described limitations of the microgrid power control method and will not be further elaborated here.

[0125] In an exemplary embodiment, Figure 5 As shown, a microgrid power control device 500 is provided, comprising: a parameter acquisition module 51, a data processing module 52, an impedance adjustment module 53, a target parameter determination module 54 and an operation control module 55, wherein:

[0126] A parameter acquisition module 51 is configured to acquire operating parameters of a preselected type of distributed power source in the microgrid during the current period, and determine the initial active power and initial reactive power of each of the distributed power sources based on the operating parameters;

[0127] a data processing module 52 configured to obtain a first active power droop coefficient and a first reactive power droop coefficient corresponding to each of the distributed power sources, and determine a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each of the distributed power sources, and determine a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each of the distributed power sources;

[0128] an impedance adjustment module 53, configured to adjust the amplitude and phase of the line impedance between each of the distributed power sources and the corresponding common connection point, and monitor the active power change value and reactive power change value of each of the distributed power sources to determine a second active power droop coefficient corresponding to each of the first active power droop coefficients, and a second reactive power droop coefficient corresponding to each of the first reactive power droop coefficients;

[0129] a target parameter determination module 54, configured to determine a second output frequency and a second output voltage corresponding to each of the distributed power sources based on each of the second active power droop coefficients and each of the second reactive power droop coefficients, and to determine a target active power and a target reactive power corresponding to each of the distributed power sources based on the second output frequency and the second output voltage;

[0130] The operation control module 55 is used to control the operation of the microgrid through each of the target active powers and each of the target reactive powers.

[0131] In an exemplary embodiment, the data processing module 52 is also used to obtain the current output frequency of each distributed power source in the microgrid, as well as the corresponding reference frequency and reference active power; determine the corresponding first active power droop coefficient based on the current output frequency, reference frequency, reference active power and initial active power of each distributed power source; and to obtain the current maximum output current value of the load electrically connected to each distributed power source, as well as the initial value of the line resistance impedance, reference reactive power, reference voltage and current output voltage corresponding to each distributed power source; determine the corresponding first reactive power droop coefficient based on the current maximum output current value, initial value of the line resistance impedance, reference reactive power, reference voltage, current output voltage and initial reactive power of each distributed power source.

[0132] In an exemplary embodiment, the data processing module 52 is also used to obtain the line inductance between each distributed power source and the corresponding common connection point, as well as the current output voltage of each distributed power source; and determine the reference voltage based on the line inductance, current output voltage and initial reactive power of each distributed power source.

[0133] In an exemplary embodiment, the impedance adjustment module 53 is also used to determine the amplitude of the line resistance impedance used to regulate each distributed power source based on the preset positive-sequence resistance, positive-sequence inductance, positive-sequence current group, negative-sequence resistance, negative-sequence inductance, negative-sequence current group, harmonic resistance of the h-th harmonic component, harmonic inductance of the h-th harmonic component, harmonic current group of the h-th harmonic component, the angular frequency of the microgrid and the angle operator associated with the positive-sequence current group; h is a positive integer.

[0134] In an exemplary embodiment, the impedance adjustment module 53 is also used to obtain the first proportional coefficient of the voltage controller corresponding to each distributed power source, the first harmonic coefficient of the h-th harmonic component, and the second proportional coefficient of the corresponding current controller, the second harmonic coefficient of the h-th harmonic component, and obtain the preset cutoff frequency, pi, fundamental frequency, h value and Laplace operator; based on the first proportional coefficient, first harmonic coefficient, cutoff frequency, pi, fundamental frequency, h value and Laplace operator corresponding to each distributed power source, a voltage resonance controller is modeled; based on the second proportional coefficient, second harmonic coefficient, cutoff frequency, pi, fundamental frequency, h value and Laplace operator corresponding to each distributed power source, a current resonance controller is modeled; and the resonance frequency corresponding to each h-th harmonic is determined based on the voltage resonance controller and the current resonance controller.

[0135] In an exemplary embodiment, the above-mentioned parameter acquisition module 51 is used to obtain the operating parameters of the preselected types of each distributed power source in the current period in the microgrid, and determine the initial active power and initial reactive power of each distributed power source based on the operating parameters. Specifically, it is used to: obtain the output voltage data and output current data of each distributed power source in the current period in the microgrid, and determine the initial active power and initial reactive power of each distributed power source based on the output voltage data and output current data.

[0136] Each module in the aforementioned microgrid power control device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0137] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal (eg, a microgrid control terminal). The internal structure diagram thereof may be as follows: Figure 6 As shown. The computer device includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operating system and computer programs stored in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via wired or wireless communication. The wireless communication method can be achieved via Wi-Fi (wireless network communication technology), a mobile cellular network, near-field communication (NFC), or other technologies. When executed by the processor, the computer program implements a microgrid power control method. The display unit of the computer device is used to produce a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

[0138] Those skilled in the art will understand that Figure 6The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0139] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements relevant steps in a microgrid power control method when executing the computer program.

[0140] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the computer program implements relevant steps in the microgrid power control method.

[0141] In one embodiment, a computer program product is provided, comprising a computer program, which implements relevant steps in a microgrid power control method when executed by a processor.

[0142] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0143] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0144] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0145] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A microgrid power control method, characterized in that: The method comprises: Obtaining operating parameters of preselected types of distributed power sources in the microgrid during the current period, and determining initial active power and initial reactive power of each of the distributed power sources based on the operating parameters; Obtaining a first active power droop coefficient and a first reactive power droop coefficient corresponding to each of the distributed power sources, and determining a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each of the distributed power sources, and determining a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each of the distributed power sources; Regulating the amplitude and phase of the line impedance between each of the distributed power sources and the corresponding common connection point, and monitoring the active power change value and the reactive power change value of each of the distributed power sources to determine a second active power droop coefficient corresponding to each of the first active power droop coefficients, and a second reactive power droop coefficient corresponding to each of the first reactive power droop coefficients; Determining a second output frequency and a second output voltage corresponding to each of the distributed power sources based on each of the second active power droop coefficients and each of the second reactive power droop coefficients, and determining a target active power and a target reactive power corresponding to each of the distributed power sources based on the second output frequency and the second output voltage; The operation of the microgrid is controlled by the target active power and the target reactive power.

2. The method according to claim 1, characterized in that The method further comprises: Obtain the current output frequency of each distributed power source in the microgrid, as well as the corresponding reference frequency and reference active power; Determining the corresponding first active power droop coefficient based on the current output frequency, reference frequency, reference active power and initial active power of each of the distributed power sources; Obtaining a current maximum output current value of a load electrically connected to each of the distributed power sources, as well as an initial value of a line impedance, a reference reactive power, a reference voltage, and a current output voltage corresponding to each of the distributed power sources; Based on the current maximum output current value of each distributed power source, the initial value of the line impedance, the reference reactive power, the reference voltage, the current output voltage and the initial reactive power, the corresponding first reactive power droop coefficient is determined.

3. The method according to claim 2, characterized in that The method further comprises: Obtaining the line inductance between each of the distributed power sources and the corresponding common connection point, and the current output voltage of each distributed power source; The reference voltage is determined based on the line inductance, the current output voltage, and the initial reactive power of each of the distributed power sources.

4. The method according to claim 1, wherein The method further comprises: Based on the preset positive-sequence resistance, positive-sequence inductance, positive-sequence current group, negative-sequence resistance, negative-sequence inductance, negative-sequence current group, harmonic resistance of the h-th harmonic component, harmonic inductance of the h-th harmonic component, harmonic current group of the h-th harmonic component, the angular frequency of the microgrid and the angle operator associated with the positive-sequence current group, the amplitude of the line resistance impedance used to regulate each of the distributed power sources is determined; h is a positive integer.

5. The method according to claim 4, characterized in that The method further comprises: Obtaining a first proportional coefficient of the voltage controller corresponding to each of the distributed power sources, a first harmonic coefficient for the hth harmonic component, and a second proportional coefficient of the corresponding current controller, a second harmonic coefficient for the hth harmonic component, and obtaining a preset cutoff frequency, pi, fundamental frequency, value of h, and Laplace operator; Modeling a voltage resonance controller based on the first proportional coefficient, the first harmonic coefficient, the cutoff frequency, the pi, the fundamental frequency, the value of h, and the Laplace operator corresponding to each of the distributed power sources; Modeling a current resonant controller based on the second proportional coefficient, the second harmonic coefficient, the cutoff frequency, the pi, the fundamental frequency, the value of h, and the Laplace operator corresponding to each of the distributed power sources; The resonant frequency corresponding to each of the hth harmonics is determined based on the voltage resonant controller and the current resonant controller.

6. The method according to any one of claims 1 to 5, characterized in that The obtaining of operating parameters of preselected types of distributed power sources in the microgrid during the current period, and determining initial active power and initial reactive power of each distributed power source based on the operating parameters, includes: The output voltage data and the output current data of each distributed power source in the microgrid in the current period are obtained, so as to determine the initial active power and the initial reactive power of each distributed power source based on the output voltage data and the output current data.

7. A microgrid power control device, characterized in that: The device comprises: A parameter acquisition module is used to obtain the operating parameters of the preselected types of distributed power sources in the microgrid during the current period, and determine the initial active power and initial reactive power of each of the distributed power sources based on the operating parameters; a data processing module, configured to obtain a first active power droop coefficient and a first reactive power droop coefficient corresponding to each of the distributed power sources, and determine a corresponding first output frequency based on the first active power droop coefficient and the initial active power corresponding to each of the distributed power sources, and determine a corresponding first output voltage based on the first reactive power droop coefficient and the initial reactive power corresponding to each of the distributed power sources; an impedance adjustment module, configured to regulate the amplitude and phase of the line impedance between each of the distributed power sources and the corresponding common connection point, and monitor the active power change value and the reactive power change value of each of the distributed power sources to determine a second active power droop coefficient corresponding to each of the first active power droop coefficients, and a second reactive power droop coefficient corresponding to each of the first reactive power droop coefficients; a target parameter determination module, configured to determine a second output frequency and a second output voltage corresponding to each of the distributed power sources based on each of the second active power droop coefficients and each of the second reactive power droop coefficients, and determine a target active power and a target reactive power corresponding to each of the distributed power sources based on the second output frequency and the second output voltage; An operation control module is used to control the operation of the microgrid through each of the target active powers and each of the target reactive powers.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. 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 method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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