A distributed regulation method and system applied to group control power of photovoltaic inverters

Abstract

The application discloses a kind of distributed regulation method and system applied to photovoltaic inverter group control power, it is related to photovoltaic inverter technical field, including obtaining the operating state data of multiple photovoltaic inverters, grid-connected point power data and the voltage data of multiple voltage measuring points, and based on the voltage data of the multiple voltage measuring points Determine controlled voltage point and controlled voltage data;According to grid-connected point power target and controlled voltage point voltage target, generate the basic power control instruction of each photovoltaic inverter;According to the operating state data and the basic power control instruction, determine the encoding adjustment margin that each photovoltaic inverter can be superimposed on the basic power control instruction in current control period.The application can improve the accuracy of grid-connected point active, reactive and voltage regulation, reduce invalid adjustment and repeated correction, improve the stability and adaptability of photovoltaic inverter group control power regulation.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic inverter technology, and in particular to a distributed regulation method and system for group control power of photovoltaic inverters. Background Technology

[0002] With the continuous increase in the scale of distributed photovoltaic (PV) grid connection, a large number of PV inverters are being connected to distribution networks, transformer substations, industrial and commercial parks, or distributed PV aggregation systems. In order to meet the requirements of grid connection point power control, voltage control, anti-reverse current control, and dispatch-side power regulation, existing systems typically issue active power commands, reactive power commands, or power factor commands to multiple PV inverters through group control devices or edge control devices, thereby achieving group control power regulation of PV inverters.

[0003] Existing photovoltaic inverter group control methods typically allocate the group control power target to each photovoltaic inverter based on the inverter's rated capacity, current output, adjustability margin, grid connection point power deviation, or preset allocation weights. Some schemes further adjust the allocation ratio of each inverter based on historical response data, voltage sensitivity, or line models. These methods can achieve, to some extent, regulation of active power, reactive power, or local voltage at the grid connection point.

[0004] However, in actual operation, multiple photovoltaic inverters are connected to different line nodes. Due to factors such as changes in sunlight, load fluctuations, differences in line impedance, inverter control modes, and communication delays, the actual regulation effect of the same power control command varies on different inverters. Especially when photovoltaic inverters are in different states, the actual contribution of a certain inverter to the active power, reactive power, and local voltage at the grid connection point may deviate significantly from the theoretical or historical contribution.

[0005] Furthermore, under normal operating conditions, the power and voltage response at the grid connection point are simultaneously affected by fluctuations in sunlight, load changes, and the actions of other regulating equipment, making it difficult to accurately distinguish the actual regulation contribution of a particular photovoltaic inverter's control command from the response changes caused by natural operating conditions. If additional test disturbances are applied to identify the actual regulation contribution of each photovoltaic inverter, it may affect the execution of normal group control objectives. Summary of the Invention

[0006] In view of the above problems, the present invention proposes the following technical solution.

[0007] Therefore, this invention provides a distributed regulation method for photovoltaic inverter group control power to solve the problem of how to obtain the actual regulation contribution of each photovoltaic inverter to the grid connection point power and the controlled voltage point voltage during the normal photovoltaic inverter group control power regulation process without significantly disturbing the grid connection point power and the controlled voltage point voltage, and to use the actual regulation contribution to update the subsequent group control power allocation.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a distributed regulation method for the group control power of photovoltaic inverters, comprising: acquiring operating status data of multiple photovoltaic inverters, grid-connected power data, and voltage data of multiple voltage measurement points; determining a controlled voltage point and controlled voltage data based on the voltage data of the multiple voltage measurement points; generating a basic power control command for each photovoltaic inverter according to the grid-connected power target and the controlled voltage point voltage target; determining, based on the operating status data and the basic power control command, the coded adjustment margin that each photovoltaic inverter can superimpose on the basic power control command within the current control cycle; and constructing a net efficiency ratio based on the grid-connected power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid-connected power and the controlled voltage point voltage. The following steps are taken: Based on the coding sequence, candidate coding quantities are generated. Under the constraint of the coding adjustment margin, the candidate coding quantities are corrected according to the net effect constraint to obtain coding adjustment components corresponding to each photovoltaic inverter. The predicted net changes of the coding adjustment components to the grid-connected power and the controlled voltage point are respectively within the corresponding threshold ranges. The coding adjustment components are superimposed on the basic power control command to generate a group control power command, which is then sent to the corresponding photovoltaic inverters. Response data of each photovoltaic inverter after executing the group control power command is obtained, and the actual adjustment contribution of each photovoltaic inverter is determined based on the coding adjustment components and the response data. The contribution relationship and group control power allocation for subsequent control cycles are updated based on the actual adjustment contribution. As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the operating status data includes the current active power, current reactive power, rated capacity, DC-side available power, active power ramp rate, and reactive power ramp rate of each photovoltaic inverter; the grid connection point power data includes grid connection point active power data and grid connection point reactive power data; the coded regulation margin includes active power forward coded margin, active power reverse coded margin, reactive power forward coded margin, and reactive power reverse coded margin; wherein, the active power forward coded margin and the active power reverse coded margin are determined based on the current active power, DC-side available power, active power ramp rate, and basic active power command, and the reactive power forward coded margin and the reactive power reverse coded margin are determined based on the current active power, current reactive power, rated capacity, reactive power ramp rate, and basic reactive power command.

[0009] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the method for determining the controlled voltage point is as follows: calculating the voltage deviation between the voltage value of each voltage measurement point and the preset voltage reference value; determining the voltage measurement point with the largest voltage deviation as the controlled voltage point; when there are two voltage measurement points with the same voltage deviation, determining the voltage measurement point with the lower voltage value as the controlled voltage point.

[0010] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the contribution relationship includes: the contribution relationship of the active power regulation and reactive power regulation of each photovoltaic inverter to the active power of the grid connection point; the contribution relationship of the active power regulation and reactive power regulation of each photovoltaic inverter to the reactive power of the grid connection point; and the contribution relationship of the active power regulation and reactive power regulation of each photovoltaic inverter to the voltage of the controlled voltage point. When the method is executed for the first time, the contribution relationship is determined based on the power distribution line model, the inverter connection location, and the line parameters. After completing one coding window, the contribution relationship is updated based on the actual regulation contribution determined in that coding window.

[0011] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the generation of candidate codes based on the coding sequence includes: assigning coding sequences with a correlation less than a preset correlation threshold to the active power regulation channel and reactive power regulation channel of each photovoltaic inverter; generating active power code candidate quantities and reactive power code candidate quantities corresponding to each photovoltaic inverter according to the coding sequence and the coding amplitude of each photovoltaic inverter; wherein, the coding amplitude is determined according to the coding regulation margin.

[0012] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the correction of the coded candidate quantity according to the net effect constraint includes: calculating the predicted net change of the coded candidate quantity on the active power, reactive power and controlled voltage point of the grid connection point based on the contribution relationship; when the predicted net change exceeds the corresponding threshold range, determining the net effect compensation amount to offset the predicted net change; allocating the net effect compensation amount to the active power regulation channel and reactive power regulation channel that still have coded regulation margin to obtain the coded regulation component; when the predicted net change does not exceed the corresponding threshold range, determining the coded candidate quantity as the coded regulation component.

[0013] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the coding sequence is generated by an orthogonal coding matrix; within a coding window, the active power regulation channel and reactive power regulation channel of each photovoltaic inverter correspond to a coding sequence in the orthogonal coding matrix; within the same coding window, the correlation between the coding sequences corresponding to different regulation channels is less than a preset correlation threshold.

[0014] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the response data includes the actual active power and actual reactive power of each photovoltaic inverter, the active power at the grid connection point, the reactive power at the grid connection point, and the voltage value of the controlled voltage point; determining the actual regulation contribution of each photovoltaic inverter based on the coded regulation component and the response data includes: time aligning the response data; subtracting the reference response without the superimposed coded regulation component from the time-aligned response data; and performing correlation decoding between the subtracted response data and the coded sequence corresponding to the coded regulation component to obtain the actual regulation contribution of each photovoltaic inverter.

[0015] As a preferred embodiment of the distributed regulation method for group control power of photovoltaic inverters described in this invention, the following steps are included: updating the contribution relationship and group control power allocation of subsequent control cycles based on the actual regulation contribution: updating the contribution relationship of each photovoltaic inverter to the active power, reactive power and controlled voltage point of the grid connection point, based on the actual regulation contribution; determining the power allocation weight of each photovoltaic inverter in subsequent control cycles based on the updated contribution relationship; and generating the basic power control command for subsequent control cycles based on the power allocation weight.

[0016] Secondly, the present invention provides a distributed regulation system for group control power of photovoltaic inverters, comprising: a data acquisition module for acquiring operating status data of multiple photovoltaic inverters, grid-connected power data, and voltage data of multiple voltage measurement points, and determining a controlled voltage point and controlled voltage data based on the voltage data of the multiple voltage measurement points; a basic instruction module for generating basic power control instructions for each photovoltaic inverter based on the grid-connected power target and the controlled voltage point voltage target; an encoding margin module for determining the encoding adjustment margin that each photovoltaic inverter can superimpose on the basic power control instructions within the current control cycle based on the operating status data and the basic power control instructions; and a net effect constraint module for constructing a net effect constraint based on the grid-connected power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid-connected power and the controlled voltage point voltage. The system comprises the following modules: a coding component module, used to generate coding candidate quantities based on the coding sequence, and, under the constraint of the coding adjustment margin, to modify the coding candidate quantities according to the net effect constraint to obtain coding adjustment components corresponding to each photovoltaic inverter, wherein the predicted net changes of the coding adjustment components to the grid-connected power and the controlled voltage point voltage are respectively within the corresponding threshold ranges; an instruction issuance module, used to superimpose the coding adjustment components onto the basic power control instruction to generate a group control power instruction, and to issue the group control power instruction to the corresponding photovoltaic inverter; a contribution determination module, used to obtain the response data of each photovoltaic inverter after executing the group control power instruction, and to determine the actual adjustment contribution of each photovoltaic inverter according to the coding adjustment components and the response data; and an allocation module, used to update the contribution relationship and group control power allocation for subsequent control cycles according to the actual adjustment contribution.

[0017] Thirdly, the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program, wherein when the computer program is executed by the processor, it implements any step of the distributed regulation method for group control power of photovoltaic inverters as described in the first aspect of the present invention.

[0018] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of the distributed regulation method for group control power of photovoltaic inverters as described in the first aspect of the present invention.

[0019] The beneficial effects of this invention are as follows: This invention superimposes coded adjustment components that satisfy net effect constraints onto the basic power control command, enabling the group control system to identify the actual adjustment contribution of each photovoltaic inverter without significantly disturbing the grid-connected power and the controlled voltage point voltage; and updates the subsequent group control power allocation based on the actual adjustment contribution, thereby improving the accuracy of active power, reactive power and voltage regulation at the grid-connected point, reducing ineffective regulation and repeated corrections, and enhancing the stability and adaptability of photovoltaic inverter group control power regulation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram illustrating an application scenario of an embodiment of the present invention. Figure 2 This is a flowchart of the distributed adjustment method according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the generation process of the encoding adjustment component in an embodiment of the present invention.

[0022] Figure 4 This is a flowchart illustrating the response decoding and contribution update process in an embodiment of the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in an implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0026] Reference Figures 1-4 This is one embodiment of the present invention, which provides a distributed regulation method for the group control power of photovoltaic inverters, comprising the following steps: S1. Acquire operating status data of multiple photovoltaic inverters, grid connection point power data, and voltage data of multiple voltage measurement points. Based on the voltage data of the multiple voltage measurement points, determine the controlled voltage point and the controlled voltage data. The operating status data of the photovoltaic inverters is collected by the inverter communication interface or the inverter agent; the grid connection point power data is collected by the grid connection point energy meter or the measurement and control device; the voltage data of the voltage measurement points is collected by the line voltage sensor, smart meter, or distribution automation terminal. The collected data has a control cycle number or timestamp. S2. Generate basic power control commands for each photovoltaic inverter based on the grid connection point power target and the controlled voltage point voltage target; S3. Based on the operating status data and the basic power control command, determine the coding adjustment margin that each photovoltaic inverter can superimpose on the basic power control command within the current control cycle; S4. Based on the grid connection point power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid connection point power and the controlled voltage point voltage, construct a net effect constraint. In this embodiment, the contribution relationship can be a linearized contribution relationship, a piecewise linear contribution relationship, or a contribution relationship that can be approximated by a linear matrix near the current operating point. S5. Generate coding candidate quantities based on the coding sequence, and under the limitation of the coding adjustment margin, modify the coding candidate quantities according to the net effect constraint to obtain the coding adjustment components corresponding to each photovoltaic inverter, wherein the predicted net change of the coding adjustment components on the grid connection point power and the controlled voltage point voltage is within the corresponding threshold range. S6. The encoded adjustment component is superimposed on the basic power control command to generate a group control power command, and the group control power command is sent to the corresponding photovoltaic inverter; S7. Obtain the response data of each photovoltaic inverter after executing the group control power command, and determine the actual regulation contribution of each photovoltaic inverter based on the coded regulation component and the response data; S8. Update the contribution relationship and group control power allocation for subsequent control cycles based on the actual adjustment contribution.

[0027] Specifically, in step S1, the operating status data includes the current active power, current reactive power, rated capacity, DC-side available power, active power ramp rate, and reactive power ramp rate of each photovoltaic inverter. The grid connection point power data includes the grid connection point active power data and the grid connection point reactive power data.

[0028] For the The control cycle is _____, let the _____ control cycle be _____. The voltage value at each voltage measurement point is The preset voltage reference value is Then the first The voltage deviation at each voltage measurement point is: ; The controlled voltage point number is determined by the following formula: ; The controlled voltage data at the controlled voltage point is: ; in, Indicates the current control cycle number; This represents the number of voltage measurement points and is a dimensionless integer. Indicates the voltage measurement point number; Indicates the first The voltage measurement point at the first The voltage value for each control cycle, in V; This indicates a preset voltage reference value, which can be set manually. The unit is... same; Indicates voltage deviation, unit: same; Indicates the controlled voltage point number; Indicates the controlled voltage point voltage value, unit: (The rest of the text appears to be incomplete and contains errors. A more accurate translation would require the full context.) same.

[0029] When the voltage deviations of two voltage measurement points are the same, the voltage measurement point with the lower voltage value is selected as the controlled voltage point to prioritize the handling of low voltage risks; when both the deviation and the voltage value are the same, the controlled voltage points can be selected according to the preset numbering order.

[0030] In step S2, the basic power control command is the command required for normal group control, and it does not contain the coded adjustment component used for contribution identification.

[0031] Let the target active power at the grid connection point be... The reactive power target for grid connection points is The actual measured active power at the grid connection point was The actual measured reactive power at the grid connection point was The target voltage at the controlled voltage point is The active power deviation at the grid connection point is: ; The reactive power regulation target increment after considering the voltage deviation at the controlled voltage point can be expressed as: ; in, and The unit is kW; and The unit is kvar; For conversion factors, the unit is kvar / V.

[0032] In one alternative implementation, weight allocation is used to obtain the first... Basic power control commands for a photovoltaic inverter: ; ; in, and They represent the first The current active power and current reactive power of the photovoltaic inverter are shown in kW and kvar, respectively. and They represent the first The basic active power command and basic reactive power command of the photovoltaic inverter are in kW and kvar respectively. and Let represent the active power allocation weight and reactive power allocation weight, respectively. Both are dimensionless quantities and satisfy the following conditions: in, The number of photovoltaic inverters participating in the group control is represented by a dimensionless integer. The basic power control command can also be generated using existing AGC, AVC, or anti-reverse current group control algorithms. This invention is not limited to a specific basic allocation algorithm.

[0033] In step S3, the coding adjustment margin includes active forward coding margin, active reverse coding margin, reactive forward coding margin, and reactive reverse coding margin.

[0034] For the first The active power forward physical margin of this photovoltaic inverter is: ; The active reverse physical margin is: ; After considering the active power ramp-up rate, the active power forward coding margin and the active power reverse coding margin are respectively: ; ; in, and The unit is kW; Indicates the first The available DC-side power of a photovoltaic inverter, in kW; and These represent the upper and lower limits of active power, respectively, in kW; This indicates the active power ramp rate, measured in kW / s. This indicates the length of the control cycle, measured in seconds (s).

[0035] For reactive power regulation margin, based on the inverter's apparent capacity constraint: ; The basic active power instruction is At that time, the first The upper limit of reactive power amplitude allowed by a photovoltaic inverter is derived from the above formula as follows: ; The above derivation comes from the apparent capacity circle constraint. Because... The unit is kVA. The unit is kW. In engineering calculations, kVA, kW, and kvar can be converted to a consistent power standard according to a unified capacity standard. Therefore, the square root of the value corresponds to the power squared. The unit is kvar.

[0036] The forward reactive power margin and the reverse reactive power margin are respectively: ; ; After considering the reactive power ramp rate, the reactive power forward coding margin and the reactive power reverse coding margin are respectively: ; ; in, This indicates the basic reactive power instruction, with the unit being kvar; , , and The units are all kvar; This represents the reactive ramp rate, measured in kvar / s.

[0037] To ensure that the coded adjustment components can be superimposed in both positive and negative forms, the active power coded amplitude and reactive power coded amplitude are further determined: ; ; in, The unit is kW. The unit is kvar; and These are the encoding amplitude coefficients, all dimensionless quantities greater than 0 and less than 1, used to reserve a safety margin. If or If the value is 0, the corresponding active power regulation channel or reactive power regulation channel will not participate in the coding in the current coding window.

[0038] In step S4, first define the first The adjustment increment of the photovoltaic inverter is: ; Arrange the active and reactive power regulation increments of all photovoltaic inverters sequentially to form a control increment vector: ; The controlled variable increment vector is defined as: ; When the adjustment increment at the current operating point does not exceed ±10% of the current operating point, a linearized contribution relationship can be used to represent the predicted impact: ; in, The unit is kW. The unit is kvar; The unit is kW. The unit is kvar. The unit is V; For the contribution relationship matrix. The columns corresponding to the active power channel represent the contribution of a unit of active power regulation to the active power, reactive power, and controlled voltage at the grid connection point; the columns corresponding to the reactive power channel represent the contribution of a unit of reactive power regulation to the aforementioned controlled quantities.

[0039] When performing the method described in this invention for the first time, It can be determined based on the power distribution line model, inverter connection location, and line parameters; after completing one coding window, Based on the actual adjustment contribution update, before the initial coding window, a baseline power flow calculation is performed on the distribution line model; a unit disturbance is applied to the active and reactive power commands of the i-th photovoltaic inverter respectively, and the changes in active power, reactive power and controlled voltage at the grid connection point are calculated. The ratio of the changes to the unit disturbance is used as the corresponding element in the contribution relationship matrix.

[0040] To construct dimensionally consistent net effect constraints, a control threshold matrix is ​​defined: ; in, The net active power effect threshold at the grid connection point, in kW; The net reactive power effect threshold at the grid connection point, in kvar; The net voltage effect threshold at the controlled voltage point, in units of 1 / 2π. same.

[0041] Define the encoded magnitude matrix: ; in, The diagonal elements have units of kW or kvar respectively; in matrix operations, each diagonal element has the same unit as the corresponding encoded channel.

[0042] To avoid inconsistencies in dimensions caused by mixing different controlled quantity units, the contribution relationship is normalized as follows: ; in, Divide the change in the controlled quantity by the corresponding threshold. The dimensionless encoded variable is converted into the actual power regulation, therefore It is a dimensionless matrix. The net effect constraint can be expressed as: ; in, Indicates the first Dimensionless coding vector for each coding control cycle Indicates the control cycle number within the encoding window; This represents a three-dimensional vector consisting of 1s, which is a dimensionless vector. This formula indicates that the predicted net changes of the coded regulation component on the active power, reactive power, and controlled voltage at the grid connection point are within the corresponding threshold ranges. The net effect constraint is used to limit the combined effect of the coded regulation component on the group control target side, but does not limit its decodeability on the local response side of each inverter.

[0043] In step S5, within a coding window, coding sequences with correlation less than a preset correlation threshold are assigned to the active power regulation channel and reactive power regulation channel of each photovoltaic inverter. Let the first... The adjustment channel is in the first The coded value for each control cycle is ,in The encoded sequence satisfies: ; Within an encoding window, the correlation between the encoded sequences corresponding to different adjustment channels satisfies the following: ; in, This represents the number of control cycles within a coding window and is a dimensionless integer. This represents a preset relevance threshold, which is a dimensionless quantity. and All are dimensionless encoded values. If an orthogonal encoding matrix is ​​used, then under ideal conditions... It can take a value of 0 or close to 0.

[0044] The encoded values ​​are combined to form a dimensionless encoded candidate vector: ; The corresponding physical coding candidate quantities are: ; in, It is a dimensionless vector; The units of the diagonal elements are kW or kvar; therefore The unit for the active power channel is kW, and the unit for the reactive power channel is kvar.

[0045] Furthermore, the coding candidate quantities are adjusted based on the net effect constraint. First, the normalized net change in prediction corresponding to the coding candidate quantities is calculated: ; in, It is a dimensionless three-dimensional vector, whose three elements represent the normalized predicted net change relative to the net active power effect threshold, the net reactive power effect threshold, and the net voltage effect threshold at the controlled voltage point, respectively.

[0046] when When the absolute value of each element is not greater than 1, it indicates that the coding candidate quantity has satisfied the net effect constraint, and at this time... As the corrected encoding vector. That is: ; when When the absolute value of any element is greater than 1, it indicates that the net change in the prediction of the encoded candidate exceeds the corresponding threshold range. To obtain the net effect compensation amount to offset the net change in prediction, the encoded candidate vector can be modified to a vector that satisfies zero or close to zero net effect. This embodiment adopts the following constraint minimum correction problem: ; ; Using the above method, while keeping the encoding vector as close as possible to the original encoding candidate vector, the net change in the prediction of the normalized controlled variable of the encoding vector is zero.

[0047] Construct the Lagrangian function for this constrained problem: ; in, Let be a Lagrange multiplier vector, which is dimensionless. For Taking the partial derivative and setting it to zero, we get: ; Therefore, we can conclude that: ; Substitution constraints ,get: ; Therefore, using the Moore-Penrose generalized inverse, we can obtain: ; The corrected encoding vector is: ; in, This represents the identity matrix, which is a dimensionless matrix. Represents the Moore-Penrose generalized inverse; This represents the dimensionless encoded vector after projection correction. The above formula essentially projects the candidate encoded vector onto the null space or approximately null space corresponding to the net effect constraint.

[0048] To satisfy the coding adjustment margin, for Limit the amplitude of each element: ; in, Indicates the adjustment channel number; and All are dimensionless quantities; Indicates when When, take 1, when Use -1 in the first case, and take the value of 1 in the other cases. It itself. It will be by The vector formed is denoted as and will As the final dimensionless coding vector, the coding adjustment component obtained after clipping is: ; in, The corresponding number in the middle The photovoltaic inverter has two elements: active power coded regulation component and reactive power coded regulation component. If the net effect constraint exceeds the threshold range again after limiting, the corresponding coded amplitude is reduced or the remaining predicted net change is allocated to the regulation channel that still has coded regulation margin, until the predicted net change of the coded regulation component on the grid-connected power and the controlled voltage point voltage is within the corresponding threshold range.

[0049] In step S6, for the first Taiwan photovoltaic inverter, the first The group control power command for each coding control cycle is: ; in, Indicates the first Taiwan photovoltaic inverter in the first The control cycle corresponds to the first control cycle within the encoding window. Group control power command for each coding control cycle; Indicates the first The active power coded regulation component of the photovoltaic inverter, in kW; Indicates the first The reactive power coded regulation component of the photovoltaic inverter, in kvar.

[0050] In step S7, after executing the group control power command, the actual active power and actual reactive power of each photovoltaic inverter are collected, along with the active power and reactive power at the grid connection point, and the voltage value at the controlled voltage point. The response vector is defined as: ; in, The three element units are kW, kvar, and V. Within an encoding window, according to The response vectors form the response matrix: ; To subtract the baseline response caused by the basic power control command and the slow variation trends of load and irradiance, a baseline response matrix without superimposed coded adjustment components is constructed: ; in, The response can be predicted based on the trend of controlled variable changes in the control cycles before the coding window (without superimposed coded adjustment components), or based on the model response corresponding to the basic power control command. When trend extrapolation is used, the controlled variables in the control cycles before the coding window (without superimposed coded adjustment components) are taken, and a linear fit is performed in chronological order. The predicted value of the fitted curve within the coding window is used as the baseline response. The coded response matrix is ​​as follows: ; in, Each column corresponds to the encoding response of an encoding control cycle, and the units of its three row elements are kW, kvar and V, respectively.

[0051] The actual regulation contribution of each photovoltaic inverter is determined based on the coded regulation components and response data. The physical coded regulation components within a coding window are then arranged into a matrix. ; in, The active power channel element is measured in kW, and the reactive power channel element is measured in kvar. To ensure consistency in the decoding calculation units, normalization is performed using the encoded amplitude matrix. ; in, This is a dimensionless encoding execution matrix; for channels with an encoded amplitude of 0, these channels do not participate in decoding and updating within the current encoding window.

[0052] The encoded response and the dimensionless encoded execution matrix satisfy the following linear relationship: ; in, This represents the response matrix of a dimensionless coded variable to a controlled variable, where each column represents the response of the controlled variable caused by variations in the corresponding coded channel from -1 to +1. The row units are kW, kvar, and V, respectively; This represents unmodeled disturbances and measurement noise, in units of... same.

[0053] For estimation Solve the following least squares problem: ; in, Let Frobenius norm be denoted. The normal equation for this least squares problem is: ; The generalized inverse method is used to solve for: ; because It is a dimensionless matrix. Units and The same. In order to obtain the actual regulation contribution of unit active or unit reactive power regulation to the controlled variable, the following will be used: Converted into a physical contribution matrix: ; in, This represents the actual modulation contribution matrix obtained by decoding the current encoding window.

[0054] In step S8, the contribution relationship is updated as follows: ; in, This represents the contribution matrix used by the current encoding window; This represents the contribution matrix used in the next encoding window; is the forgetting factor, a dimensionless quantity greater than 0 and less than 1.

[0055] In subsequent control cycles, power allocation weights can be determined based on the updated contribution relationships. One specific approach is to construct the target increment of the controlled variable for subsequent control cycles: ; in, The unit is kW. The unit is kvar. The unit is V. The corresponding normalized objective increment is: ; in, It is a dimensionless vector. A normalized contribution matrix is ​​constructed using the updated contribution relation and the encoded magnitude matrix: ; The subsequent base power allocation can be obtained through the following normalized optimization problem: ; in, Assign incremental vectors to dimensionless bases; is the regularization coefficient, which is a dimensionless quantity. We obtain... Afterwards, the physical power allocation increment is: ; in, The unit for the active power channel is kW, and the unit for the reactive power channel is kvar. Therefore, the system updates the contribution relationship and group control power allocation for subsequent control cycles based on the actual adjustment contribution.

[0056] This embodiment also provides a distributed regulation system for the group control power of photovoltaic inverters. The system includes a data acquisition module, a basic instruction module, an encoding margin module, a net effect constraint module, an encoding component module, an instruction issuance module, a contribution determination module, and an allocation module. This distributed regulation system can be deployed in a transformer substation edge controller, a photovoltaic group control gateway, or a park energy management server. Each module can be executed by the same processor or distributed across multiple edge nodes for collaborative execution.

[0057] Specifically, the data acquisition module acquires the operating status data of multiple photovoltaic inverters, the power data at the grid connection point, and the voltage data of multiple voltage measurement points, and determines the controlled voltage point and the controlled voltage data based on the voltage data of the multiple voltage measurement points. The basic instruction module is used to generate basic power control instructions for each photovoltaic inverter based on the grid connection point power target and the controlled voltage point voltage target. The coding margin module is used to determine the coding adjustment margin that each photovoltaic inverter can superimpose on the basic power control command within the current control cycle based on the operating status data and the basic power control command. The net effect constraint module is used to construct net effect constraints based on the grid connection point power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid connection point power and the controlled voltage point voltage. The coding component module is used to generate coding candidate quantities based on the coding sequence, and under the limitation of the coding adjustment margin, to modify the coding candidate quantities according to the net effect constraint to obtain the coding adjustment components corresponding to each photovoltaic inverter, wherein the predicted net changes of the coding adjustment components to the grid connection point power and the controlled voltage point voltage are respectively within the corresponding threshold range. The instruction issuing module is used to superimpose the coded adjustment component onto the basic power control instruction to generate a group control power instruction, and issue the group control power instruction to the corresponding photovoltaic inverter; The contribution determination module is used to obtain the response data of each photovoltaic inverter after executing the group control power command, and to determine the actual regulation contribution of each photovoltaic inverter based on the coded adjustment component and the response data. The allocation module is used to update the contribution relationship and group control power allocation for subsequent control cycles based on the actual adjustment contribution.

[0058] This embodiment also provides a computer device applicable to a distributed regulation method for group control power of photovoltaic inverters, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to realize the distributed regulation method for group control power of photovoltaic inverters as proposed in the above embodiment.

[0059] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0060] This embodiment also provides a storage medium storing a computer program. When executed by a processor, the program implements the distributed regulation method for group control power of photovoltaic inverters as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0061] In summary, this invention superimposes coded regulation components that satisfy net effect constraints onto the basic power control command, enabling the group control system to identify the actual regulation contribution of each photovoltaic inverter without significantly disturbing the grid-connected power and controlled voltage. Based on this actual regulation contribution, subsequent group control power allocation is updated, thereby improving the accuracy of active, reactive, and voltage regulation at the grid-connected point, reducing ineffective regulation and redundant corrections, and enhancing the stability and adaptability of photovoltaic inverter group control power regulation.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A distributed regulation method for group control power of photovoltaic inverters, characterized in that, include: The system acquires operating status data of multiple photovoltaic inverters, grid connection point power data, and voltage data from multiple voltage measurement points, and determines the controlled voltage point and controlled voltage data based on the voltage data from the multiple voltage measurement points. Based on the grid connection point power target and the controlled voltage point voltage target, generate basic power control commands for each photovoltaic inverter; Based on the operating status data and the basic power control command, determine the coding adjustment margin that each photovoltaic inverter can superimpose on the basic power control command within the current control cycle; Based on the grid connection point power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid connection point power and the controlled voltage point voltage, a net effect constraint is constructed. Based on the coding sequence, candidate coding quantities are generated, and under the constraint of the coding adjustment margin, the candidate coding quantities are corrected according to the net effect constraint to obtain the coding adjustment components corresponding to each photovoltaic inverter. The coded adjustment component is superimposed on the basic power control command to generate a group control power command, and the group control power command is sent to the corresponding photovoltaic inverter. Obtain the response data of each photovoltaic inverter after executing the group control power command, and determine the actual regulation contribution of each photovoltaic inverter based on the coded regulation component and the response data; The contribution relationship and group control power allocation for subsequent control cycles are updated based on the actual adjustment contribution.

2. The distributed regulation method for group control power of photovoltaic inverters as described in claim 1, characterized in that: The operating status data includes the current active power, current reactive power, rated capacity, DC side available power, active power ramp rate, and reactive power ramp rate of each photovoltaic inverter; The grid connection point power data includes grid connection point active power data and grid connection point reactive power data; The coding adjustment margin includes active forward coding margin, active reverse coding margin, reactive forward coding margin, and reactive reverse coding margin; The active power forward coding margin and the active power reverse coding margin are determined based on the current active power, DC side available power, active power ramp rate and basic active power command, while the reactive power forward coding margin and the reactive power reverse coding margin are determined based on the current active power, current reactive power, rated capacity, reactive power ramp rate and basic reactive power command.

3. The distributed regulation method for group control power of photovoltaic inverters as described in claim 1, characterized in that, The method for determining the controlled voltage point is as follows: Calculate the voltage deviation between the voltage value at each voltage measurement point and the preset voltage reference value; The voltage measurement point with the largest voltage deviation is determined as the controlled voltage point; When there are two voltage measurement points with the same voltage deviation, the voltage measurement point with the lower voltage value is determined as the controlled voltage point.

4. The distributed regulation method for group control power of photovoltaic inverters as described in claim 2, characterized in that, The contribution relationships include: The contribution relationship between the active power regulation and reactive power regulation of each photovoltaic inverter to the active power at the grid connection point; The contribution relationship between the active power regulation and reactive power regulation of each photovoltaic inverter to the reactive power at the grid connection point; The contribution relationship between the active power regulation and reactive power regulation of each photovoltaic inverter to the voltage at the controlled voltage point; When the method is executed for the first time, the contribution relationship is determined based on the power distribution line model, the inverter connection location, and the line parameters; after a coding window is completed, the contribution relationship is updated based on the actual adjustment contribution determined in the coding window.

5. The distributed regulation method for group control power of photovoltaic inverters as described in claim 2, characterized in that, Generating candidate codes based on the encoded sequence includes: Assign coding sequences with correlation less than a preset correlation threshold to the active power regulation channel and reactive power regulation channel of each photovoltaic inverter; Based on the coding sequence and the coding amplitude of each photovoltaic inverter, active power coding candidate quantities and reactive power coding candidate quantities corresponding to each photovoltaic inverter are generated; The encoding amplitude is determined based on the encoding adjustment margin.

6. The distributed regulation method for group control power of photovoltaic inverters as described in claim 5, characterized in that, The modification of the coding candidate quantity based on the net effect constraint includes: Based on the contribution relationship, calculate the predicted net change of the coded candidate quantity on the active power, reactive power and controlled voltage point of the grid connection point. When the predicted net change exceeds the corresponding threshold range, a net effect compensation amount is determined to offset the predicted net change. The net effect compensation amount is allocated to the active power regulation channel and the reactive power regulation channel, which still have coding regulation margin, to obtain the coding regulation component; When the predicted net change does not exceed the corresponding threshold range, the coding candidate quantity is determined as the coding adjustment component.

7. The distributed regulation method for group control power of photovoltaic inverters as described in claim 5, characterized in that: The encoded sequence is generated by an orthogonal encoding matrix; Within a coding window, the active power regulation channel and reactive power regulation channel of each photovoltaic inverter correspond to a coding sequence in the orthogonal coding matrix, respectively. Within the same encoding window, the correlation between the encoding sequences corresponding to different adjustment channels is less than the preset correlation threshold.

8. The distributed regulation method for group control power of photovoltaic inverters as described in claim 2, characterized in that: The response data includes the actual active power and actual reactive power of each photovoltaic inverter, the active power at the grid connection point, the reactive power at the grid connection point, and the voltage value of the controlled voltage point. The actual regulation contribution of each photovoltaic inverter is determined based on the coded regulation component and the response data, including: The response data is time-aligned; Subtract the baseline response without superimposed coded adjustment components from the time-aligned response data; The subtracted response data is correlated with the encoded sequence corresponding to the encoded adjustment component to obtain the actual adjustment contribution of each photovoltaic inverter.

9. The distributed regulation method for group control power of photovoltaic inverters as described in claim 2, characterized in that, The contribution relationship and group control power allocation for subsequent control cycles are updated based on the actual adjustment contribution, including: The contribution relationship between each photovoltaic inverter to the active power, reactive power and controlled voltage point of the grid connection point is updated based on the actual adjustment contribution. Based on the updated contribution relationship, the power allocation weight of each photovoltaic inverter in subsequent control cycles is determined; The basic power control command for subsequent control cycles is generated based on the power allocation weights.

10. A distributed regulation system for group control power of photovoltaic inverters, based on the distributed regulation method for group control power of photovoltaic inverters as described in any one of claims 1-9, characterized in that, include: The data acquisition module acquires the operating status data of multiple photovoltaic inverters, the power data of the grid connection point, and the voltage data of multiple voltage measurement points, and determines the controlled voltage point and the controlled voltage data based on the voltage data of the multiple voltage measurement points. The basic instruction module is used to generate basic power control instructions for each photovoltaic inverter based on the grid connection point power target and the controlled voltage point voltage target. The coding margin module is used to determine the coding adjustment margin that each photovoltaic inverter can superimpose on the basic power control command within the current control cycle based on the operating status data and the basic power control command. The net effect constraint module is used to construct net effect constraints based on the grid connection point power data, the controlled voltage data, and the contribution relationship of each photovoltaic inverter to the grid connection point power and the controlled voltage point voltage. The coding component module is used to generate coding candidate quantities based on the coding sequence, and under the limitation of the coding adjustment margin, to modify the coding candidate quantities according to the net effect constraint to obtain the coding adjustment components corresponding to each photovoltaic inverter, wherein the predicted net changes of the coding adjustment components to the grid connection point power and the controlled voltage point voltage are respectively within the corresponding threshold range. The instruction issuing module is used to superimpose the coded adjustment component onto the basic power control instruction to generate a group control power instruction, and issue the group control power instruction to the corresponding photovoltaic inverter; The contribution determination module is used to obtain the response data of each photovoltaic inverter after executing the group control power command, and to determine the actual regulation contribution of each photovoltaic inverter based on the coded adjustment component and the response data. The allocation module is used to update the contribution relationship and group control power allocation for subsequent control cycles based on the actual adjustment contribution.

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