A distributed cooperative control method for reactive voltage of a photovoltaic power station

Abstract

The present application relates to power distribution network operation control technical field, especially to a kind of photovoltaic power station reactive power voltage distributed collaborative control method, comprising: in the process of distributed reactive power voltage control operation, each photovoltaic power station node is not under the condition that fixed collaborative control object or fixed neighborhood relationship is not set in advance, based on the operating state of each node independently participates in reactive power regulation;During reactive power regulation, the voltage change information of own node is continuously collected, and the voltage change information is associated with the operating state change information of other photovoltaic power station nodes in the operation process, to form operating response data;Based on operating response data, other photovoltaic power station nodes that affect the voltage of own node are identified, and a collaborative object set is formed locally;In the process of control operation, each photovoltaic power station node evaluates the collaborative relationship, and updates the collaborative object set when the evaluation result changes, and independently executes reactive power regulation decision based on the updated collaborative object set.

Description

Technical Field

[0001] This invention relates to the field of power distribution network operation control technology, and in particular to a distributed collaborative control method for reactive power and voltage in photovoltaic power plants. Background Technology

[0002] With the large-scale integration of distributed photovoltaic (PV) power stations into distribution networks, the participation of PV power stations in reactive power regulation via inverters has become an important technical means for voltage control in distribution networks. Existing distributed reactive power voltage control methods are usually based on the electrical topology of the distribution network or voltage sensitivity relationships obtained through offline calculations. In the control design stage, the cooperative control objects or fixed neighborhood relationships between each PV power station are pre-determined, and reactive power regulation is carried out according to the preset cooperative structure during operation to achieve regulation of the voltage at distribution network nodes.

[0003] In actual power distribution network operation, due to errors in line parameters, random fluctuations in load distribution, and frequent changes in power distribution network operation mode, the actual impact range of reactive power regulation of photovoltaic power plants on system voltage has significant uncertainty and time-varying characteristics. This makes it difficult for the pre-set cooperative relationship based on static topology or offline model to continuously reflect the real electrical impact relationship, thereby affecting the effectiveness of distributed reactive power voltage control. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides a distributed collaborative control method for reactive power and voltage in photovoltaic power plants. It aims to improve the problem that the collaborative relationships pre-set based on static topology or offline models are difficult to continuously reflect the real electrical influence relationships, thereby affecting the effectiveness of distributed reactive power and voltage control.

[0005] This invention provides the following technical solution: a distributed collaborative control method for reactive power and voltage in a photovoltaic power station, comprising the following steps:

[0006] S1. During the operation of distributed reactive power and voltage control, each photovoltaic power station node independently participates in reactive power regulation based on its own node's operating status without pre-setting a fixed collaborative control object or fixed neighborhood relationship.

[0007] S2. When implementing reactive power regulation, each photovoltaic power station node continuously collects its own voltage change information and correlates the voltage change information with the operating status change information of other photovoltaic power station nodes during operation to form operating response data.

[0008] S3. Based on the operation response data, each photovoltaic power station node identifies other photovoltaic power station nodes that affect its own node voltage and forms a set of collaborative objects locally.

[0009] S4. During the continuous operation of distributed reactive power and voltage control, each photovoltaic power station node evaluates the collaborative relationship of each collaborative object in the collaborative object set based on the latest operation response data, and participates in reactive power regulation decision-making based on the evaluation results.

[0010] S5. When the evaluation result of the collaboration relationship changes, update the collaboration object set so that the collaboration object set can be adjusted according to the change of the running status;

[0011] S6. During the continuous updating of the collaborative object set, each photovoltaic power station node independently executes reactive power regulation decisions based on its own collaborative object set.

[0012] By adopting the above technical solution, the distributed reactive power voltage control operation no longer relies on pre-set cooperative relationships based on static topology or offline models. Instead, each photovoltaic power station node dynamically identifies cooperative objects that affect its own node voltage based on the correlation between voltage changes after reactive power adjustment and changes in the operating status of other photovoltaic power stations, and forms a set of cooperative objects locally. This allows the cooperative relationships to be updated with changes in the operating status of the distribution network, so that the cooperative relationships on which the distributed reactive power voltage control is based can reflect the actual electrical influence relationships during operation, avoiding the problem of reactive power voltage control effect being affected by the deviation between the cooperative relationships and the actual electrical action relationships.

[0013] Preferably, in step S1, the step of independently participating in reactive power regulation based on the operating state of each node includes:

[0014] Obtain the operating status information of photovoltaic power station nodes, wherein the operating status information includes at least one of the following: active power output status, reactive power regulation margin, and node voltage level of photovoltaic power station nodes;

[0015] Based on the obtained operating status information, determine the available range of reactive power regulation for the current photovoltaic power station nodes;

[0016] Without relying on a centralized control unit, the photovoltaic power station nodes independently generate and execute corresponding reactive power regulation commands based on the determined available range of reactive power regulation.

[0017] Preferably, in step S2, the step of continuously collecting voltage change information of its own node includes:

[0018] During the operation of distributed reactive power and voltage control, the node voltage values ​​of the photovoltaic power station nodes are obtained within the current control cycle;

[0019] Obtain the node voltage value corresponding to the photovoltaic power station node before and after adjacent control cycles or reactive power regulation;

[0020] Based on the node voltage values ​​obtained at different times, the voltage change information of the photovoltaic power station nodes is determined.

[0021] Preferably, in step S2, the information on the changes in the operating status of the other photovoltaic power station nodes includes:

[0022] During the operation of distributed reactive power and voltage control, the range of photovoltaic power plant nodes used to participate in the construction of operation response data is determined based on the topology or operation mode of the distribution network.

[0023] From the determined range of photovoltaic power station nodes, obtain the information on the changes in the operating status of the corresponding photovoltaic power station nodes. The range of photovoltaic power station nodes includes at least one of the following: physically adjacent photovoltaic power station nodes, photovoltaic power station nodes located on the same feeder, or photovoltaic power station nodes that have a communication connection with the current photovoltaic power station node.

[0024] Preferably, in step S2, the step of associating the voltage change information with the operating status change information of other photovoltaic power station nodes during operation includes:

[0025] The voltage change information and the operating status change information are correlated according to the time correspondence within the same control cycle;

[0026] When performing reactive power regulation operations at photovoltaic power plant nodes, the voltage change information before and after the reactive power regulation operation is correlated with the operating status change information.

[0027] Based on the consistency of the changing trends of voltage change information and operating status change information over multiple control cycles, the two are correlated.

[0028] Preferably, in step S3, the step of identifying other photovoltaic power plant nodes that affect its own node voltage includes:

[0029] During the operation of distributed reactive power and voltage control, the characteristics of node voltage change corresponding to changes in the operating status of other photovoltaic power station nodes are determined based on the operation response data.

[0030] Within multiple control cycles, the characteristics of node voltage changes are compared to determine whether the characteristics of node voltage changes are consistent with the operating status changes of other photovoltaic power plant nodes.

[0031] When the voltage change characteristics of a node are consistent with the operating status changes of other corresponding photovoltaic power plant nodes over multiple control cycles, the other photovoltaic power plant node is identified as a photovoltaic power plant node that affects its own node voltage.

[0032] Preferably, in step S3, the step of forming a set of collaborative objects locally includes:

[0033] After identifying other photovoltaic power plant nodes that affect its own node voltage, the current photovoltaic power plant node maintains a list of collaborative objects locally to store the identified other photovoltaic power plant nodes.

[0034] Based on the continuous updates of the operation response data, the photovoltaic power station nodes in the collaborative object list are dynamically maintained, including adding newly identified photovoltaic power station nodes to the collaborative object list or removing photovoltaic power station nodes that no longer meet the identification conditions from the collaborative object list.

[0035] The dynamically maintained list of collaborative objects is used as the set of collaborative objects for the current photovoltaic power station node.

[0036] Preferably, in step S4, the step of evaluating the collaborative relationships corresponding to each collaborative object in the collaborative object set includes:

[0037] Based on the operational response data, the operational status change information of each collaborative object in the collaborative object set and the voltage change information of the current photovoltaic power station node are obtained respectively;

[0038] Within multiple control cycles, the operating status change information and voltage change information of each collaborative object are compared and analyzed to determine the correlation characteristics between the corresponding collaborative object and the current photovoltaic power station node;

[0039] Based on the identified association characteristics, the collaborative relationships corresponding to each collaborative object in the collaborative object set are evaluated.

[0040] Preferably, in step S5, the step of updating the set of collaborative objects includes:

[0041] Based on the evaluation results of the collaborative relationships corresponding to each collaborative object in the collaborative object set, it is determined whether the collaborative relationships have changed;

[0042] When the evaluation results indicate that the collaboration relationship corresponding to a certain collaboration object no longer meets the preset association conditions, the collaboration object is removed from the collaboration object set.

[0043] When the evaluation results show that the collaborative relationship corresponding to the new photovoltaic power station node meets the preset association conditions, the photovoltaic power station node will be added to the collaborative object set.

[0044] After the set of collaborative objects changes, the updated set of collaborative objects is continuously maintained, and the next control cycle begins.

[0045] Preferably, in step S6, the step of independently executing reactive power regulation decisions based on their respective sets of cooperative objects includes:

[0046] During the operation of distributed reactive power and voltage control, the current photovoltaic power station node obtains the operating status information of each collaborative object in the collaborative object set based on its locally maintained collaborative object set.

[0047] Based on the obtained collaborative object operation status information and combined with the current photovoltaic power station node's own operation status, the corresponding reactive power regulation decision quantity is calculated.

[0048] Without relying on a centralized control unit, the current photovoltaic power station node performs the corresponding reactive power regulation operation based on the reactive power regulation decision.

[0049] The present invention has the following beneficial effects:

[0050] 1. In this invention, by introducing a self-generating mechanism of cooperative relationship based on operation response correlation, the distributed reactive power voltage control operation does not rely on static electrical topology or offline sensitivity model, but dynamically generates a set of cooperative objects based on the voltage response characteristics after reactive power regulation of the photovoltaic power station. This enables the cooperative relationship to truly reflect the actual impact range of reactive power regulation of the photovoltaic power station on the system voltage during operation, thereby avoiding the problem of mismatch between the cooperative relationship and the actual electrical impact relationship.

[0051] 2. In this invention, the cooperative relationship is regarded as a dynamic control object that evolves with the operating state. By continuously evaluating and updating the effectiveness of the cooperative relationship, the set of cooperative objects can be adjusted according to changes in load level, photovoltaic power output structure and network operation mode. This avoids the long-term reliance of distributed reactive power control on the operation of failed cooperative structures and enhances the consistency between reactive power regulation strategy and real-time operating state.

[0052] 3. In this invention, distributed reactive power cooperative control allows each photovoltaic power station to form a local cooperative relationship based on its own observable information, without forcing the cooperative cognition to remain consistent across all nodes. This reduces the dependence on communication conditions and centralized coordination mechanisms. Even when communication is limited or information is incomplete, each photovoltaic power station can still participate in reactive power regulation independently, giving distributed reactive power voltage control good robustness and engineering adaptability. Attached Figure Description

[0053] Figure 1 This is a flowchart of a distributed collaborative control method for reactive power voltage in a photovoltaic power plant proposed in this invention. Detailed Implementation

[0054] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] In a first embodiment of the present invention, the present invention provides a distributed collaborative control method for reactive power and voltage in a photovoltaic power station, such as... Figure 1 As shown, it includes the following steps:

[0056] S1. During the operation of distributed reactive power and voltage control, each photovoltaic power station node independently participates in reactive power regulation based on its own node's operating status without pre-setting a fixed collaborative control object or fixed neighborhood relationship.

[0057] Furthermore, in step S1, the steps of independently participating in reactive power regulation based on the operating status of each node include:

[0058] Obtain the operating status information of photovoltaic power plant nodes. The operating status information includes at least one of the following: active power output status, reactive power regulation margin, and node voltage level.

[0059] Based on the obtained operating status information, determine the available range of reactive power regulation for the current photovoltaic power station nodes;

[0060] Without relying on a centralized control unit, the photovoltaic power station nodes independently generate and execute corresponding reactive power regulation commands based on the determined available range of reactive power regulation.

[0061] Specifically, the distributed collaborative control of reactive power and voltage in photovoltaic power plants enters the distributed reactive power and voltage control operation state in the initial stage of operation. Each photovoltaic power plant node does not rely on the centralized control unit or the pre-configured collaborative control object relationship, but participates in the reactive power regulation process based on the real-time operation status of its own node. This operation mode enables each photovoltaic power plant node to maintain independence at the control level and to be connected to the distribution network operation system as a distributed control unit.

[0062] In the specific implementation process, each photovoltaic power station node is equipped with an operation status acquisition module to obtain the operation status information of the node in the current control cycle. The operation status information may include at least one of the active power output status, reactive power regulation margin, and node voltage level of the photovoltaic power station node. The specific acquisition method can be realized through the internal monitoring unit of the inverter, the node voltage measurement device, or the control interface. The active power output status is used to reflect the current power generation level of the photovoltaic power station, the reactive power regulation margin is used to characterize the range of reactive power regulation capabilities that the photovoltaic power station can provide under the current operation status, and the node voltage level is used to reflect the real-time voltage status of the photovoltaic power station connection point.

[0063] After acquiring the aforementioned operating status information, the photovoltaic power station nodes process the information to determine the available reactive power regulation range for the current photovoltaic power station node. The available reactive power regulation range can be calculated based on the rated capacity of the photovoltaic inverter, the current active power output, and operating constraints. In one possible implementation, the available reactive power regulation range can be determined through the following relationship:

[0064] ;

[0065] in, This indicates the available range of reactive power regulation at the current photovoltaic power station node. This indicates the rated apparent power of the photovoltaic inverter. This represents the active power output of the current photovoltaic power station node. All of the above parameters can be obtained or calculated locally by the photovoltaic power station node. In specific applications, this calculation method can be adjusted according to the equipment type or operating requirements.

[0066] After determining the available range of reactive power regulation, the photovoltaic power station nodes independently generate corresponding reactive power regulation instructions based on the determined available range of reactive power regulation without relying on the centralized control unit. The reactive power regulation instructions are used to indicate the reactive power output level of the photovoltaic inverter in the current control cycle. The generation of the reactive power regulation instructions can be completed based on the local control logic and can be adapted and adjusted in combination with the current node voltage level or operating constraints.

[0067] After generating a reactive power regulation command, the photovoltaic power station node sends the command to the corresponding photovoltaic inverter execution unit, which then performs the corresponding reactive power output operation, thereby completing the reactive power regulation process based on the node's own operating status. This process can be repeated in each control cycle, enabling the photovoltaic power station node to continuously participate in reactive power and voltage control operation in a distributed manner.

[0068] Through the above implementation methods, each photovoltaic power station node can independently generate and execute reactive power adjustment commands based on its own node's operating status during the distributed reactive power and voltage control operation, providing basic operating conditions for subsequent collaborative relationship identification and collaborative control processes based on operating response data.

[0069] S2. When implementing reactive power regulation, each photovoltaic power station node continuously collects its own voltage change information and correlates the voltage change information with the operating status change information of other photovoltaic power station nodes during operation to form operating response data.

[0070] Furthermore, in step S2, the step of continuously collecting voltage change information of its own node includes:

[0071] During the operation of distributed reactive power and voltage control, the node voltage values ​​of the photovoltaic power station nodes are obtained within the current control cycle;

[0072] Obtain the node voltage value corresponding to the photovoltaic power station node before and after adjacent control cycles or reactive power regulation;

[0073] Based on the node voltage values ​​obtained at different times, the voltage change information of the photovoltaic power station nodes is determined.

[0074] Furthermore, in step S2, the information on changes in the operating status of other photovoltaic power station nodes includes:

[0075] During the operation of distributed reactive power and voltage control, the range of photovoltaic power plant nodes used to participate in the construction of operation response data is determined based on the topology or operation mode of the distribution network.

[0076] From the determined range of photovoltaic power station nodes, obtain the information on the changes in the operating status of the corresponding photovoltaic power station nodes. The range of photovoltaic power station nodes includes at least one of the following: physically adjacent photovoltaic power station nodes, photovoltaic power station nodes located on the same feeder, or photovoltaic power station nodes that have a communication connection with the current photovoltaic power station node.

[0077] Furthermore, in step S2, the step of associating the voltage change information with the operating status change information of other photovoltaic power station nodes during operation includes:

[0078] The voltage change information and the operating status change information are correlated according to the time correspondence within the same control cycle;

[0079] When performing reactive power regulation operations at photovoltaic power plant nodes, the voltage change information before and after the reactive power regulation operation is correlated with the operating status change information.

[0080] Based on the consistency of the changing trends of voltage change information and operating status change information over multiple control cycles, the two are correlated.

[0081] Specifically, under the distributed reactive power and voltage control operation, each photovoltaic power station node simultaneously enters the process of collecting and constructing operation response data while performing reactive power regulation operations. The operation response data is used to reflect the correspondence between the reactive power regulation behavior of the photovoltaic power station node and the system voltage change, and serves as the basic data for subsequent identification and evaluation of collaborative relationships.

[0082] In the specific implementation process, each photovoltaic power station node is equipped with a voltage acquisition and time synchronization module, which is used to continuously acquire node voltage information during the operation of distributed reactive power and voltage control. The node voltage information can be acquired through inverter measurement interface, voltage transformer or station monitoring device. In one possible implementation, the photovoltaic power station node acquires the node voltage value once in the current control cycle, and acquires the corresponding node voltage value again before and after the adjacent control cycle or reactive power adjustment operation. By recording and comparing the node voltage values ​​at different times, the voltage change information in the current control cycle is determined.

[0083] Voltage change information can be represented as the difference or change in node voltage values ​​at adjacent time points. In one possible implementation, voltage change information can be characterized by the following relationship:

[0084] ;

[0085] in, This indicates the node voltage change information within the current control cycle. This represents the node voltage value acquired at the current moment. This represents the node voltage value obtained before the previous control cycle or reactive power regulation. The time interval between adjacent control cycles is indicated by the above parameters, which can all be obtained by local measurement or calculation at the photovoltaic power plant nodes.

[0086] To construct complete operational response data, in addition to collecting its own node voltage change information, photovoltaic power plant nodes also acquire operational status change information of other photovoltaic power plant nodes during operation. The selection of other photovoltaic power plant nodes is not fixed or preset, but dynamically determined based on the distribution network topology or operation mode. In one possible implementation, the range of photovoltaic power plant nodes used to participate in the construction of operational response data can be determined according to feeder structure, switch status, or communication connection relationship.

[0087] From the determined range of photovoltaic power station nodes, the photovoltaic power station nodes obtain the corresponding photovoltaic power station node operation status change information. The operation status change information may include changes in the active power output, reactive power output, or operation status switching information of the photovoltaic power station nodes. The range of photovoltaic power station nodes includes at least one of the following: photovoltaic power station nodes that are physically adjacent, photovoltaic power station nodes that are located on the same feeder, or photovoltaic power station nodes that have a communication connection with the current photovoltaic power station node. This selection method helps to ensure that there is a potential electrical correlation between the obtained operation status change information and the voltage change of the current photovoltaic power station node.

[0088] After acquiring voltage change information and other photovoltaic power station node operation status change information, the photovoltaic power station node performs correlation processing on the above information to form operation response data. In one possible implementation, the correlation processing can be carried out according to the time correspondence between voltage change information and operation status change information within the same control cycle, so that the reactive power regulation behavior within the same control cycle is correlated with voltage change.

[0089] The correlation processing can also be combined with the timing of reactive power regulation operations. When a photovoltaic power station node performs a reactive power regulation operation, the voltage change information before and after the reactive power regulation operation is correlated with the operating status change information of other photovoltaic power station nodes in the same time period, thereby reflecting the relationship between reactive power regulation behavior and system voltage response.

[0090] To avoid the impact of random fluctuations on the construction of operational response data, correlation processing can also be performed over multiple control cycles. In one possible implementation, the changing trends of voltage change information and operational status change information over multiple control cycles are analyzed. When the two show a consistent changing trend over multiple control cycles, the corresponding data pairs are incorporated into the operational response data, thereby constructing an operational response dataset with time continuity.

[0091] The operational response data generated in the above manner is stored or cached locally at the photovoltaic power plant nodes and continuously updated in subsequent control cycles, providing basic data support for the identification of collaborative objects, assessment of collaborative relationships, and collaborative control decisions in subsequent steps.

[0092] S3. Based on the operation response data, each photovoltaic power station node identifies other photovoltaic power station nodes that affect its own node voltage and forms a set of collaborative objects locally.

[0093] Furthermore, in step S3, the step of identifying other photovoltaic power plant nodes that affect its own node voltage includes:

[0094] During the operation of distributed reactive power and voltage control, the characteristics of node voltage change corresponding to changes in the operating status of other photovoltaic power station nodes are determined based on the operation response data.

[0095] Within multiple control cycles, the characteristics of node voltage changes are compared to determine whether the characteristics of node voltage changes are consistent with the operating status changes of other photovoltaic power plant nodes.

[0096] When the voltage change characteristics of a node are consistent with the operating status changes of other corresponding photovoltaic power plant nodes over multiple control cycles, the other photovoltaic power plant node is identified as a photovoltaic power plant node that affects its own node voltage.

[0097] Furthermore, in step S3, the step of forming a set of collaborative objects locally includes:

[0098] After identifying other photovoltaic power plant nodes that affect its own node voltage, the current photovoltaic power plant node maintains a list of collaborative objects locally to store the identified other photovoltaic power plant nodes.

[0099] Based on the continuous updates of the operation response data, the photovoltaic power station nodes in the collaborative object list are dynamically maintained, including adding newly identified photovoltaic power station nodes to the collaborative object list or removing photovoltaic power station nodes that no longer meet the identification conditions from the collaborative object list.

[0100] The dynamically maintained list of collaborative objects is used as the set of collaborative objects for the current photovoltaic power station node.

[0101] Specifically, under the distributed reactive power and voltage control operation, after the photovoltaic power station nodes complete the construction and update of the operation response data, they enter the process of identifying collaborative objects and forming a collaborative object set based on the operation response data. This process can be repeated in each control cycle and is completed independently by each photovoltaic power station node locally, without relying on the centralized control unit.

[0102] In the specific implementation process, the photovoltaic power station nodes use the operation response data as the input data source. The operation response data includes at least the node voltage change information of the current photovoltaic power station node and the operation status change information of other photovoltaic power station nodes. For each other photovoltaic power station node in the operation response data, the photovoltaic power station node extracts the node voltage change feature corresponding to its operation status change information, which is used to characterize the correspondence between the operation status change of the other photovoltaic power station node and the voltage change of the current photovoltaic power station node. In one possible implementation, the node voltage change feature can be composed of node voltage change information within multiple control cycles and can be represented by a change trend sequence.

[0103] To facilitate comparative analysis of node voltage variation characteristics, photovoltaic power plant nodes can construct voltage variation sequences and state variation sequences over multiple consecutive control cycles; the voltage variation sequence can be represented as:

[0104] ;

[0105] The state change sequence can be represented as:

[0106] ;

[0107] in, Indicates the current photovoltaic power station node at time [time]. Information on node voltage changes within the corresponding control cycle. Indicates continuous The voltage change sequence formed within each control cycle Indicates the first Other photovoltaic power station nodes at time Information on changes in operating status within the corresponding control cycle. Indicates the first Other photovoltaic power station nodes are in continuous The state change sequence formed within each control cycle Indicates the number of control cycles used for comparative analysis. Indicates the first The sampling time corresponding to each control cycle;

[0108] The photovoltaic power plant nodes compare their voltage change characteristics over multiple control cycles to determine whether these characteristics are consistent with the operating status changes of other corresponding photovoltaic power plant nodes. This consistency judgment can be based on the consistency of the change trends. One possible implementation is to use a sign consistency criterion, i.e., comparing the characteristics of each control cycle. and Check whether the signs are consistent, and count the number of control cycles with consistent signs; the sign consistency ratio can be expressed as:

[0109] ;

[0110] in, Indicates the first The consistency ratio corresponding to each of the other photovoltaic power station nodes. This indicates an indicator function that takes the value 1 if the condition within the parentheses is true, and 0 otherwise. Indicates during the control cycle The symbols for internal node voltage change information and operating status change information are consistent.

[0111] When the consistency judgment result meets the preset consistency judgment condition, the corresponding other photovoltaic power station nodes are identified as photovoltaic power station nodes that affect the voltage of the current photovoltaic power station node. The preset consistency judgment condition can be set in the form of a threshold. In one possible implementation, when the consistency ratio... Not less than the consistency threshold At that time, identify the first Other photovoltaic power station nodes are considered as influencing nodes, among which The consistency threshold can be selected as an empirical value or determined by on-site debugging. In another possible implementation, the consistency judgment condition can also be judged based on the trend of change and the consistency within a number of consecutive control cycles, thereby combining the consistency judgment condition with the runtime sequence characteristics.

[0112] After identifying other photovoltaic power plant nodes that affect the voltage of the current photovoltaic power plant node, the current photovoltaic power plant node maintains a list of collaborating objects locally. The list of collaborating objects is used to store the identification information of the identified affected nodes. The identification information of the affected nodes may include at least one of the following: photovoltaic power plant node number, communication address, or equipment identification information. The list of collaborating objects may be stored in the local controller, inverter control unit, or on-site control terminal.

[0113] As the operational response data is continuously updated in subsequent control cycles, the current photovoltaic power plant node dynamically maintains the list of collaborative objects. Dynamic maintenance includes re-performing consistency judgment on candidate photovoltaic power plant nodes based on the latest operational response data and consistency judgment conditions, adding newly identified affected nodes to the list of collaborative objects, and removing affected nodes that no longer meet the consistency judgment conditions from the list of collaborative objects. To ensure the continuity of the dynamic maintenance process, the list of collaborative objects can retain the time information or control cycle index information of the node's most recent fulfillment of the consistency judgment conditions, which can be used to support subsequent removal judgments.

[0114] The current photovoltaic power plant node uses the dynamically maintained list of collaborative objects as the collaborative object set, and participates in the data processing related to reactive power regulation decision-making in subsequent steps based on the collaborative object set. The collaborative object set is formed locally and updated with the control cycle. The composition of the collaborative object set depends on the operation response data and consistency judgment results, so that the collaborative object set maintains a corresponding relationship with the voltage response during operation.

[0115] S4. During the continuous operation of distributed reactive power and voltage control, each photovoltaic power station node evaluates the collaborative relationship of each collaborative object in the collaborative object set based on the latest operation response data, and participates in reactive power regulation decision-making based on the evaluation results.

[0116] Furthermore, in step S4, the step of evaluating the collaborative relationships corresponding to each collaborative object in the collaborative object set includes:

[0117] Based on the operational response data, the operational status change information of each collaborative object in the collaborative object set and the voltage change information of the current photovoltaic power station node are obtained respectively;

[0118] Within multiple control cycles, the operating status change information and voltage change information of each collaborative object are compared and analyzed to determine the correlation characteristics between the corresponding collaborative object and the current photovoltaic power station node;

[0119] Based on the identified association characteristics, the collaborative relationships corresponding to each collaborative object in the collaborative object set are evaluated.

[0120] Specifically, under the continuous operation of distributed reactive power and voltage control, after the photovoltaic power station node completes the local formation and dynamic maintenance of the collaborative object set, it enters the collaborative relationship evaluation process. The collaborative relationship evaluation process uses the latest updated operation response data as the data source and runs in conjunction with the reactive power regulation decision process in each control cycle, so that the operation association between each collaborative object in the collaborative object set and the current photovoltaic power station node is in a calculable and updatable state.

[0121] In the specific implementation process, for each collaborative object in the collaborative object set, the current photovoltaic power station node extracts the corresponding operating status change information and the voltage change information of the current photovoltaic power station node based on the operation response data. The operating status change information may include at least one of the active power output change, reactive power output change, or operating status switching information of the collaborative object node, and the voltage change information is the node voltage change information of the current photovoltaic power station node within the control cycle. To ensure the comparability of the data, the operating status change information and the voltage change information can be stored in alignment according to the control cycle in the data structure, and the control cycle index or timestamp is used as the matching basis.

[0122] To generate correlation features that can be used for evaluation, the current photovoltaic power plant node compares and analyzes the changes in the operating status of the cooperating object with the voltage changes of the current node over multiple control cycles. The comparison and analysis process can be based on a time window, which can consist of multiple consecutive control cycles. The window length can be selected as an empirical value or determined by on-site commissioning. In one possible implementation, the comparison and analysis includes a joint analysis of the consistency of the direction of change, the correlation of the magnitude of change, and the persistence of change between the operating status change information and the voltage change information, thereby obtaining correlation features that characterize the degree of correlation between the cooperating object and the current node.

[0123] The correlation characteristics can be characterized using quantitative indicators for processing in reactive power regulation decisions. In one possible implementation, the current photovoltaic power station node can construct a correlation coefficient for each cooperating object to characterize the statistical correlation between the operating state changes of that cooperating object and the voltage changes of the current node. The correlation coefficient can be calculated using the Pearson correlation coefficient, a statistical measure used to assess the degree of linear correlation between two sets of sequences, with a value range of [missing value]. Within a time window, for the first For a group of collaborative objects, the correlation coefficient can be expressed as:

[0124] ;

[0125] in, Indicates the first The association coefficient corresponding to each collaborative object Indicates the first Each collaborative object at time Information on changes in operating status within the corresponding control cycle. Indicates the current photovoltaic power station node at time [time]. Voltage change information within the corresponding control cycle. Indicates the number of control cycles within the time window. Indicates the first time within the time window The average value of the runtime status change information of each collaborative object. This represents the average value of the voltage change information of the current photovoltaic power station nodes within the time window. The average value can be obtained by averaging the corresponding sequence within the time window.

[0126] In addition to linear correlation measurement, correlation features can also include indicators such as the consistency ratio of change trend, the number of consistency in change direction, or the range of change magnitude ratio. The current photovoltaic power station node can select one or more of these indicators to form a correlation feature vector according to the engineering application conditions, and store the correlation feature vector and the collaborative object identification information locally for subsequent use in the control cycle iteration.

[0127] After obtaining the association characteristics between the collaborative objects and the current photovoltaic power station node, the current photovoltaic power station node evaluates the collaborative relationships corresponding to each collaborative object in the collaborative object set based on the association characteristics. The evaluation process may include determining the effectiveness level, association strength level, or association direction attribute of the collaborative relationship. In one possible implementation, the collaborative relationships can be classified according to the sign and absolute value range of the association coefficient, where the sign of the association coefficient is used to characterize the association direction attribute, the absolute value of the association coefficient is used to characterize the association strength level, and the classification threshold can be selected as an empirical value or determined by on-site debugging.

[0128] After the assessment is completed, the current photovoltaic power station node will save the assessment results corresponding to each collaborative object in the form of a local data structure. The assessment results may include collaborative object identification information, associated characteristic parameters and corresponding assessment classification information. The assessment results can be recalculated as the operation response data is updated in subsequent control cycles and interact with the reactive power regulation decision-making process in the same control cycle, so that the reactive power regulation decision-making process can process based on the assessment information of the collaborative object set.

[0129] S5. When the evaluation result of the collaboration relationship changes, update the collaboration object set so that the collaboration object set can be adjusted according to the change of the running status;

[0130] Furthermore, in step S5, the step of updating the set of collaborative objects includes:

[0131] Based on the evaluation results of the collaborative relationships corresponding to each collaborative object in the collaborative object set, it is determined whether the collaborative relationships have changed;

[0132] When the evaluation results indicate that the collaboration relationship corresponding to a certain collaboration object no longer meets the preset association conditions, the collaboration object is removed from the collaboration object set.

[0133] When the evaluation results show that the collaborative relationship corresponding to the new photovoltaic power station node meets the preset association conditions, the photovoltaic power station node will be added to the collaborative object set.

[0134] After the set of collaborative objects changes, the updated set of collaborative objects is continuously maintained, and the next control cycle begins.

[0135] Specifically, under the continuous operation of distributed reactive power and voltage control, after the photovoltaic power station nodes complete the collaborative relationship assessment and obtain the corresponding assessment results, they enter the collaborative object set update process. The collaborative object set update process is matched with the control cycle iteration and is triggered at the end of each control cycle or at a preset update time, so as to map the changes in the collaborative relationship assessment results to the composition of the collaborative object set.

[0136] In the specific implementation process, the photovoltaic power station node maintains a set of collaborative objects and its associated evaluation result cache locally. The evaluation result cache can include collaborative object identification information, associated feature parameters, and evaluation classification information. After the photovoltaic power station node completes the collaborative relationship evaluation based on the latest operation response data in the current control cycle, it compares the evaluation result obtained in the current control cycle with the evaluation result stored in the previous control cycle or the previous update cycle to determine whether the collaborative relationship has changed. The change in the collaborative relationship can be manifested as the associated feature parameters crossing the preset threshold range, the evaluation classification switching, or the associated direction attribute changing. The photovoltaic power station node can use one or more of the above change types as change criteria.

[0137] To facilitate a unified determination of changes in collaborative relationships, photovoltaic power station nodes set preset association conditions locally. These preset association conditions define the rules for retaining collaborative objects in the collaborative object set. These preset association conditions can be based on the association coefficients output during the collaborative relationship evaluation process. The threshold rules are defined, where For the first The correlation coefficients between each collaborating object and the current photovoltaic power station node are calculated in the collaborative relationship evaluation process, and the collaborative object set update process directly reads the evaluation output. And without double counting;

[0138] In one possible implementation, the preset association condition can be defined as the absolute value of the association coefficient satisfying a threshold constraint, which can be expressed as:

[0139] ;

[0140] in, This represents the correlation threshold, the value of which can be selected as an empirical value or determined by on-site debugging. Time to determine the first If the collaboration relationship between a number of collaboration objects does not meet the preset association conditions, when Time to determine the first Each collaborative object corresponds to a collaborative relationship that satisfies the preset association conditions;

[0141] When the evaluation results indicate that the collaborative relationship corresponding to a certain collaborative object no longer meets the preset association conditions, the photovoltaic power station node performs a removal process locally. The removal process includes deleting the identification information of the collaborative object from the collaborative object set and synchronously updating the data structure index corresponding to the collaborative object set. The data structure index may include at least one of the collaborative object list index, communication connection information, or historical evaluation record pointer, so as to ensure that the traversal and calling process of the collaborative object set in the subsequent control cycle is consistent with the updated set.

[0142] When the evaluation results show that the collaborative relationship of the new photovoltaic power station node meets the preset association conditions, the photovoltaic power station node performs the joining process locally. The joining process includes writing the identification information of the photovoltaic power station node into the collaborative object set and establishing a corresponding evaluation result record item for the node. The new photovoltaic power station node can come from the candidate node in the operation response data that has obtained the operation status change information but has not yet been included in the collaborative object set, or it can come from the node that newly enters the node range in the subsequent control cycle.

[0143] To avoid frequent additions and subtractions of the set of collaborative objects within adjacent control cycles, photovoltaic power station nodes can introduce persistent constraints on preset association conditions. These persistent constraints limit the number of consecutive control cycles in which the preset association conditions are met or not met. In one possible implementation, removing the decision condition can be expressed as:

[0144] ;

[0145] The inclusion of the judgment condition can be expressed as:

[0146] ;

[0147] in, Indicates the first The first collaborative object in the... The correlation coefficient corresponding to each control cycle This indicates the number of consecutive control cycles required to make a removal decision. This indicates the number of consecutive control cycles required to add a decision. This indicates an indicator function. It takes a value of 1 when the condition in parentheses is met, and a value of 0 otherwise. The above parameters can be selected as empirical values ​​or determined by on-site commissioning. When the photovoltaic power station node meets the corresponding judgment condition, it will be removed or added.

[0148] After the set of collaborative objects changes, the photovoltaic power station nodes maintain the updated set of collaborative objects continuously, including the synchronous update of collaborative object identification information, communication connection information and evaluation result cache. When entering the next control cycle, the nodes perform subsequent collaborative relationship evaluation and reactive power regulation decision-making based on the updated set of collaborative objects, so that the collaborative object set update process and control cycle iteration form a closed-loop operation logic.

[0149] S6. During the continuous updating of the collaborative object set, each photovoltaic power station node independently executes reactive power regulation decisions based on its own collaborative object set.

[0150] Furthermore, in step S6, the step of independently executing reactive power regulation decisions based on their respective sets of cooperative objects includes:

[0151] During the operation of distributed reactive power and voltage control, the current photovoltaic power station node obtains the operating status information of each collaborative object in the collaborative object set based on its locally maintained collaborative object set.

[0152] Based on the obtained collaborative object operation status information and combined with the current photovoltaic power station node's own operation status, the corresponding reactive power regulation decision quantity is calculated.

[0153] Without relying on a centralized control unit, the current photovoltaic power station node performs the corresponding reactive power regulation operation based on the reactive power regulation decision.

[0154] Specifically, under the continuous operation of distributed reactive power and voltage control, after the photovoltaic power station node completes the formation and update of the collaborative object set, it enters the reactive power regulation decision execution stage based on the collaborative object set. This stage runs synchronously with the control cycle and is completed independently by each photovoltaic power station node locally, without relying on the centralized control unit or global unified scheduling.

[0155] In the specific implementation process, the current photovoltaic power station node obtains the operating status information of each collaborative object in the collaborative object set based on its locally maintained collaborative object set. The operating status information may include at least one of the following: active power output change, reactive power output status, voltage level or operating mode switching information of the collaborative object node. The acquisition of operating status information can be achieved through inter-node communication interface, data caching or status broadcasting mechanism. The acquisition process is consistent with the aforementioned operation response data construction process in time to ensure the temporal consistency of decision input data.

[0156] While acquiring the operating status information of the cooperating objects, the nodes of the current photovoltaic power station also acquire the operating status information of their own nodes. The operating status information of their own nodes can include the current active power output level, reactive power regulation margin, and node voltage status, which are used to characterize the adjustable capability range and operating constraints of the current node within the control cycle. The operating status information of the cooperating objects and the operating status information of the nodes are collected locally to form the input dataset for reactive power regulation decision.

[0157] The current photovoltaic power plant node calculates the corresponding reactive power regulation decision quantity based on the input dataset. The reactive power regulation decision quantity is used to indicate the magnitude or direction of reactive power output adjustment of the photovoltaic power plant node within the current control cycle. In one possible implementation, the reactive power regulation decision quantity can be calculated using a weighted superposition model. This model obtains the decision result by comprehensively processing the changes in the operating state of the cooperating object and its own operating state. The reactive power regulation decision quantity can be expressed as:

[0158] ;

[0159] in, This represents the reactive power regulation decision quantity of the current photovoltaic power plant node within the control cycle. This represents the basic reactive power adjustment determined based on its own operating status. This represents the set of collaborative objects corresponding to the current photovoltaic power station node. Indicates the index of the collaborative object. Indicates the first The weight coefficients corresponding to each collaborative object can be determined from the collaborative relationship evaluation results. Indicates the first Information on the changes in the operating status of each collaborative object within the current control cycle. This represents a mapping function that maps information about changes in operating status to reactive power regulation contribution. The mapping function can be implemented using a linear function, a piecewise linear function, or a lookup table.

[0160] Basic reactive power regulation The base reactive power regulation can be determined based on the current operating status of the photovoltaic power plant nodes. In one possible implementation, the base reactive power regulation can be calculated by combining the node voltage deviation and reactive power regulation margin, with a weighting factor... The correlation coefficient or correlation level obtained during the assessment of the collaborative relationship can be set to make the influence of different collaborative objects in reactive power regulation decisions different;

[0161] After obtaining the reactive power regulation decision amount, the current photovoltaic power station node performs constraint verification on the reactive power regulation decision amount. The constraint verification is used to ensure that the reactive power regulation decision amount does not exceed the node's available reactive power regulation range. The constraint verification can be implemented through saturation limitation or interval pruning. In one possible implementation, the reactive power regulation decision amount is constrained as follows:

[0162] ;

[0163] in, This represents the final output reactive power regulation. and These represent the lower and upper limits of the reactive power output allowed by the current photovoltaic power station node within the control cycle, respectively. The above limits can be determined by the reactive power adjustment margin or equipment operation constraints.

[0164] After completing the calculation and constraint verification of the reactive power regulation decision quantity, the current photovoltaic power station node sends the reactive power regulation command to the corresponding inverter control unit for execution without relying on the centralized control unit. The inverter adjusts the reactive power output level according to the reactive power regulation command to complete the reactive power regulation operation within the current control cycle. The execution result is fed back to the operation response data construction process again in the subsequent control cycle through the node voltage change information, thus forming a complete distributed collaborative control operation process with the aforementioned collaborative object identification, evaluation and update process.

[0165] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A distributed collaborative control method for reactive power and voltage in a photovoltaic power station, characterized in that, Includes the following steps: S1. During the operation of distributed reactive power and voltage control, each photovoltaic power station node independently participates in reactive power regulation based on its own node's operating status without pre-setting a fixed collaborative control object or fixed neighborhood relationship. S2. When implementing reactive power regulation, each photovoltaic power station node continuously collects its own voltage change information and correlates the voltage change information with the operating status change information of other photovoltaic power station nodes during operation to form operating response data. S3. Based on the operation response data, each photovoltaic power station node identifies other photovoltaic power station nodes that affect its own node voltage and forms a set of collaborative objects locally. In step S3, the step of identifying other photovoltaic power plant nodes that affect its own node voltage includes: During the operation of distributed reactive power and voltage control, the characteristics of node voltage change corresponding to changes in the operating status of other photovoltaic power station nodes are determined based on the operation response data. Within multiple control cycles, the characteristics of node voltage changes are compared to determine whether the characteristics of node voltage changes are consistent with the operating status changes of other photovoltaic power plant nodes. When the voltage change characteristics of a node are consistent with the operating status changes of other corresponding photovoltaic power station nodes over multiple control cycles, the other photovoltaic power station node is identified as a photovoltaic power station node that affects its own node voltage. S4. During the continuous operation of distributed reactive power and voltage control, each photovoltaic power station node evaluates the collaborative relationship of each collaborative object in the collaborative object set based on the latest operation response data, and participates in reactive power regulation decision-making based on the evaluation results. In step S4, the step of evaluating the collaborative relationships corresponding to each collaborative object in the collaborative object set includes: Based on the operational response data, the operational status change information of each collaborative object in the collaborative object set and the voltage change information of the current photovoltaic power station node are obtained respectively; Within multiple control cycles, the operating status change information and voltage change information of each collaborative object are compared and analyzed to determine the correlation characteristics between the corresponding collaborative object and the current photovoltaic power station node; Based on the identified association characteristics, the collaborative relationships corresponding to each collaborative object in the collaborative object set are evaluated; S5. When the evaluation result of the collaboration relationship changes, update the collaboration object set so that the collaboration object set can be adjusted according to the change of the running status; S6. During the continuous updating of the collaborative object set, each photovoltaic power station node independently executes reactive power regulation decisions based on its own collaborative object set.

2. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S1, the step of independently participating in reactive power regulation based on the operating state of each node includes: Obtain the operating status information of photovoltaic power station nodes, wherein the operating status information includes at least one of the following: active power output status, reactive power regulation margin, and node voltage level of photovoltaic power station nodes; Based on the obtained operating status information, determine the available range of reactive power regulation for the current photovoltaic power station nodes; Without relying on a centralized control unit, the photovoltaic power station nodes independently generate and execute corresponding reactive power regulation commands based on the determined available range of reactive power regulation.

3. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S2, the step of continuously collecting voltage change information of its own node includes: During the operation of distributed reactive power and voltage control, the node voltage values ​​of the photovoltaic power station nodes are obtained within the current control cycle; Obtain the node voltage value corresponding to the photovoltaic power station node before and after adjacent control cycles or reactive power regulation; Based on the node voltage values ​​obtained at different times, the voltage change information of the photovoltaic power station nodes is determined.

4. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S2, the information on the changes in the operating status of the other photovoltaic power station nodes includes: During the operation of distributed reactive power and voltage control, the range of photovoltaic power plant nodes used to participate in the construction of operation response data is determined based on the topology or operation mode of the distribution network. From the determined range of photovoltaic power station nodes, obtain the information on the changes in the operating status of the corresponding photovoltaic power station nodes. The range of photovoltaic power station nodes includes at least one of the following: physically adjacent photovoltaic power station nodes, photovoltaic power station nodes located on the same feeder, or photovoltaic power station nodes that have a communication connection with the current photovoltaic power station node.

5. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S2, the step of associating the voltage change information with the operating status change information of other photovoltaic power station nodes during operation includes: The voltage change information and the operating status change information are correlated according to the time correspondence within the same control cycle; When performing reactive power regulation operations at photovoltaic power plant nodes, the voltage change information before and after the reactive power regulation operation is correlated with the operating status change information. Based on the consistency of the changing trends of voltage change information and operating status change information over multiple control cycles, the two are correlated.

6. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S3, the step of forming a set of collaborative objects locally includes: After identifying other photovoltaic power plant nodes that affect its own node voltage, the current photovoltaic power plant node maintains a list of collaborative objects locally to store the identified other photovoltaic power plant nodes. Based on the continuous updates of the operation response data, the photovoltaic power station nodes in the collaborative object list are dynamically maintained, including adding newly identified photovoltaic power station nodes to the collaborative object list or removing photovoltaic power station nodes that no longer meet the identification conditions from the collaborative object list. The dynamically maintained list of collaborative objects is used as the set of collaborative objects for the current photovoltaic power station node.

7. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S5, the step of updating the set of collaborative objects includes: Based on the evaluation results of the collaborative relationships corresponding to each collaborative object in the collaborative object set, it is determined whether the collaborative relationships have changed; When the evaluation results indicate that the collaboration relationship corresponding to a certain collaboration object no longer meets the preset association conditions, the collaboration object is removed from the collaboration object set. When the evaluation results show that the collaborative relationship corresponding to the new photovoltaic power station node meets the preset association conditions, the photovoltaic power station node will be added to the collaborative object set. After the set of collaborative objects changes, the updated set of collaborative objects is continuously maintained, and the next control cycle begins.

8. The distributed collaborative control method for reactive power and voltage in a photovoltaic power station according to claim 1, characterized in that, In step S6, the step of independently executing reactive power regulation decisions based on their respective sets of cooperative objects includes: During the operation of distributed reactive power and voltage control, the current photovoltaic power station node obtains the operating status information of each collaborative object in the collaborative object set based on its locally maintained collaborative object set. Based on the obtained collaborative object operation status information and combined with the current photovoltaic power station node's own operation status, the corresponding reactive power regulation decision quantity is calculated. Without relying on a centralized control unit, the current photovoltaic power station node performs the corresponding reactive power regulation operation based on the reactive power regulation decision.

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