Optical-storage-charging collaborative management and high-quality power supply method under limited measurement of power distribution network

Abstract

This application provides a method for coordinated management and high-quality power supply of photovoltaic-energy storage-charging networks under limited measurement conditions. The method includes: acquiring system operating conditions and aggregated power; determining whether to update power control commands based on system operating conditions; if so, determining whether the current control level needs to be reset based on system operating conditions; if not, updating power control commands based on system operating conditions, aggregated power, and the current control level; correcting the power control commands to obtain corrected power control commands; allocating the corrected power control commands and performing corresponding control; determining whether the current control level has reached the maximum control level; if so, ending the update of power control commands. The method proposed in this application, through multi-level control and feedback correction, can manage both distribution network voltage and load rate under limited measurement information. Simultaneously, by setting control priorities for resources such as photovoltaics, energy storage, and charging piles, the utilization rate of photovoltaics is improved.

Description

Technical Field

[0001] This application relates to the field of power technology, and in particular to a method for coordinated management and control of photovoltaic-storage-charging systems and high-quality power supply under limited measurement conditions in distribution networks. Background Technology

[0002] Following the trend of reducing energy consumption and greenhouse gas emissions, the penetration rate of distributed photovoltaic (PV) and electric vehicles (EVs) in low-voltage distribution networks is rapidly increasing. However, the volatility of PV output, the spatiotemporal randomness of EV charging behavior, and the overlap of peak and off-peak loads are leading to increasingly prominent problems of transformer overload and node voltage exceeding limits in distribution substations, seriously threatening the safe and economical operation of the distribution network. To alleviate these problems, the coordinated management of distributed resources (DERs) such as PV, energy storage (ESS), and charging piles has become a key approach.

[0003] Existing research on the coordinated management and control of photovoltaic-storage-charging systems in low-voltage distribution networks mainly focuses on optimization modeling and data-driven approaches. However, in low-voltage distribution networks with incomplete measurement information, existing coordinated management and control methods face fundamental bottlenecks. 1) Optimization strategies based on physical models (such as model predictive control) require accurate network parameters to construct power flow equations, but low-voltage distribution networks are complex with missing measurements, making it difficult to establish accurate mathematical models. 2) Artificial intelligence (AI)-based control algorithms rely on massive amounts of historical data for training, but actual low-voltage distribution area measurement device coverage is insufficient, and topology changes are frequent, resulting in a lack of training samples and poor model generalization ability. In addition, while existing lightweight methods (such as rule-based control) reduce computational complexity, they neglect the dynamic coupling characteristics between resources, making it difficult to balance voltage safety and transformer load balancing. Summary of the Invention

[0004] This application provides a method for coordinated management and control of photovoltaic-storage-charging networks and high-quality power supply under limited measurement conditions in distribution networks. To solve the above-mentioned technical problems, this application adopts the following technical methods:

[0005] This application provides a method for coordinated management and control of photovoltaic-storage-charging systems and high-quality power supply under limited measurement conditions in distribution networks, including:

[0006] Step S101: Obtain system operating conditions and aggregated power;

[0007] Step S102: Based on the system operating conditions, determine whether to update the power control command;

[0008] If so, proceed to step S103;

[0009] Step S103: Based on the system operating conditions, determine whether the current control level needs to be reset;

[0010] If not, proceed to step S104;

[0011] Step S104: Update the power control command based on the system operating conditions, the aggregated power, and the current control level;

[0012] Step S105: Modify the power control command to obtain a modified power control command;

[0013] Step S106: Assign the corrected power control command and perform corresponding control;

[0014] Step S107: Determine whether the current control level has reached the maximum control level;

[0015] If so, then stop updating the power control command;

[0016] If not, increment the current control level by 1 and proceed to step S101.

[0017] Optionally, the process for determining the polymerization power is as follows:

[0018] Electrical information is collected from a limited number of monitoring points, including grid-connected nodes of photovoltaic, energy storage, and charging piles, as well as transformers; the electrical information includes the power generation capacity of photovoltaic, the maximum charging and discharging power of energy storage, and the maximum adjustable power of charging piles.

[0019] The electrical information is aggregated to obtain aggregated power, which includes the total photovoltaic power generation capacity, the total maximum chargeable and dischargeable power of energy storage, and the total maximum adjustable power of the charging pile.

[0020] Optionally, the system operating conditions include voltage operating conditions and transformer load operating conditions, and the process of determining the system operating conditions is as follows:

[0021] Collect operating condition assessment information from a limited number of monitoring points, including the output power of the transformer and the voltage at the photovoltaic grid connection point;

[0022] Based on the output power of the transformer, the operating conditions of the transformer load are determined, including normal operating conditions and abnormal operating conditions.

[0023] Based on the voltage at the photovoltaic grid connection point, the voltage operating conditions are determined, including normal voltage operating conditions and abnormal voltage operating conditions.

[0024] Optionally, determining whether to update the power control command based on the system's operating conditions includes:

[0025] Determine whether the system is operating under abnormal voltage or abnormal transformer load conditions.

[0026] If so, update the power control command and execute step S103;

[0027] If not, maintain the current output.

[0028] Optionally, the power regulation command includes a voltage over-limit power regulation command and a heavy overload power regulation command. The step of updating the power regulation command based on the system operating conditions, the aggregated power, and the current regulation level includes:

[0029] Step S201: Determine whether the system is operating under abnormal voltage conditions;

[0030] If so, proceed to step S202;

[0031] If not, proceed to step S203;

[0032] Step S202: Based on the abnormal voltage operation condition, the aggregated power, and the current control level, update the voltage over-limit power control command;

[0033] Step S203: Determine whether the system is operating under abnormal transformer load conditions;

[0034] If so, proceed to step S204;

[0035] If not, proceed to step S105;

[0036] Step S204: Based on the abnormal operating conditions of the transformer load, the aggregated power, and the current control level, update the heavy overload power control command;

[0037] Step S205: Overwrite the voltage over-limit power control command with the heavy overload power control command, and execute step S105.

[0038] Optionally, the abnormal voltage operating conditions include node voltage exceeding the lower limit and node voltage exceeding the upper limit, and the voltage exceeding the limit power control command includes a first active power control command and a first reactive power control command under the abnormal voltage operating conditions; the first active power control command includes a first photovoltaic active power control command, a first energy storage active power control command, and a first charging pile active power control command, and the first reactive power control command includes a first photovoltaic reactive power control command and a first energy storage reactive power control command; updating the voltage exceeding the limit power control command based on the abnormal voltage operating conditions, the aggregated power, and the current control level includes:

[0039] Step S301: Determine whether the abnormal voltage operation condition is due to the node voltage falling below the lower limit;

[0040] If so, proceed to step S302;

[0041] Step S302: Determine whether the current control level is less than 1;

[0042] If so, proceed to step S303;

[0043] If not, proceed to step S304;

[0044] Step S303: Update the first photovoltaic active power control command based on the total photovoltaic power generation capacity;

[0045] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0046] Step S304: Determine whether the energy storage meets the discharge constraints;

[0047] If so, proceed to step S305;

[0048] Step S305: Determine whether the current control level has reached the first control level, where the first control level is the maximum control level set for a single type of resource;

[0049] If not, proceed to step S306;

[0050] If so, proceed to step S307;

[0051] Step S306: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage.

[0052] Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command.

[0053] Step S307: Update the active power control command of the first charging pile based on the current control level, the maximum control level, and the total maximum adjustable power of the charging pile.

[0054] Optionally, if the determination result of step S304 is negative, then the following step S308 is executed:

[0055] Step S308: Based on the current control level, the first control level, and the total maximum adjustable power of the charging pile, update the first charging pile active power control command and update the first energy storage active power control command to zero;

[0056] Based on the first energy storage active power control command which is zero and the current control level, update the first energy storage reactive power control command.

[0057] Optionally, if the determination result of step S301 is negative, then the following steps are performed:

[0058] Step S401: Determine whether the current control level is less than 1;

[0059] If so, proceed to step S402;

[0060] If not, proceed to step S403;

[0061] Step S402: Update the active power control command of the first charging pile based on the maximum adjustable power of the charging pile;

[0062] Step S403: Determine whether the energy storage meets the charging constraints;

[0063] If so, proceed to step S404;

[0064] If not, proceed to step S407;

[0065] Step S404: Determine whether the current control level has reached the first control level;

[0066] If not, proceed to step S405;

[0067] If so, proceed to step S406;

[0068] Step S405: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage.

[0069] Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command.

[0070] Step S406: Update the first photovoltaic active power control instruction based on the current control level, the maximum control level, and the total photovoltaic power generation capacity;

[0071] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0072] Step S407: Based on the current control level, the first control level, and the total photovoltaic power generation, update the first photovoltaic active power control command and update the first energy storage active power control command to zero;

[0073] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0074] Based on the first energy storage active power control command which is zero and the current control level, update the first energy storage reactive power control command.

[0075] Optionally, the abnormal operating conditions of the transformer load include forward heavy overload and reverse heavy overload, and the heavy overload power control command includes a second active power control command and a second reactive power control command under the abnormal operating conditions of the transformer load; the second active power control command includes a second photovoltaic active power control command, a second energy storage active power control command, and a second charging pile active power control command, and the second reactive power control command includes a second photovoltaic reactive power control command and a second energy storage reactive power control command; updating the heavy overload power control command based on the abnormal operating conditions of the transformer load, the aggregated power, and the current control level includes:

[0076] Step S501: Determine whether the abnormal operating condition of the transformer load is a positive heavy overload;

[0077] If so, proceed to step S502;

[0078] Step S502: Determine whether the current control level is less than 1;

[0079] If so, proceed to step S503;

[0080] If not, proceed to step S504;

[0081] Step S503: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity;

[0082] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0083] Step S504: Determine whether the energy storage meets the discharge constraint;

[0084] If so, proceed to step S505;

[0085] If not, proceed to step S508;

[0086] Step S505: Determine whether the current control level has reached the first control level;

[0087] If not, proceed to step S506;

[0088] If so, proceed to step S507;

[0089] Step S506: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage.

[0090] Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command;

[0091] Step S507: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile, the maximum control level, and the current control level;

[0092] Step S508: Based on the total maximum adjustable power of the charging pile, the current control level and the first control level, update the active power control command of the second charging pile and update the active power control command of the second energy storage to zero;

[0093] Based on the second energy storage active power control command which is zero, update the second energy storage reactive power control command.

[0094] Optionally, if the determination result of step S501 is negative, then the following steps are performed:

[0095] Step S601: Determine whether the current control level is less than 1;

[0096] If so, proceed to step S602;

[0097] If not, proceed to step S603;

[0098] Step S602: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile;

[0099] Step S603: Determine whether the energy storage meets the charging constraints;

[0100] If so, proceed to step S604;

[0101] If not, proceed to step S607;

[0102] Step S604: Determine whether the current control level has reached the first control level;

[0103] If not, proceed to step S605;

[0104] If so, proceed to step S606;

[0105] Step S605: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage, the current control level, and the first control level;

[0106] Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command;

[0107] Step S606: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity, the current control level, and the maximum control level;

[0108] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0109] Step S607: Based on the total photovoltaic power generation capacity, the current control level, and the first control level, determine the second photovoltaic active power control command and update the second energy storage active power control command to zero;

[0110] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0111] Based on the second energy storage active power control command which is zero and the current control level, update the second energy storage reactive power control command.

[0112] This application has the following beneficial effects:

[0113] The method proposed in this application, through multi-level regulation and feedback correction, can balance the control of distribution network voltage and load rate under limited measurement information. Simultaneously, by setting the regulation priorities for resources such as photovoltaics, energy storage, and charging piles, the utilization rate of photovoltaics is improved. Attached Figure Description

[0114] Figure 1 This is a flowchart illustrating the method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network provided in the embodiments of this application;

[0115] Figure 2 This is a flowchart illustrating the process of determining a specific updated power control command provided in an embodiment of this application;

[0116] Figure 3 This is a schematic diagram of the process of updating the power control command when the voltage of a distribution network node falls below the lower limit, as provided in the embodiments of this application.

[0117] Figure 4 This is a schematic diagram of the process of updating the power control command when the voltage of a distribution network node exceeds the upper limit, provided in an embodiment of this application.

[0118] Figure 5 This is a schematic diagram of the process of updating power control commands when the distribution network is under positive heavy overload, as provided in the embodiments of this application.

[0119] Figure 6 This is a flowchart illustrating the process of updating power control commands when a distribution network experiences reverse heavy overload, as provided in an embodiment of this application.

[0120] Figure 7 This is a waveform diagram of the load situation in the transformer area during the simulation stage provided in the embodiments of this application;

[0121] Figure 8 This is a waveform diagram of the photovoltaic predicted power during the simulation stage provided in the embodiments of this application;

[0122] Figure 9This is a waveform diagram of the charging load during the simulation stage provided in this application embodiment;

[0123] Figure 10 This is a simulation stage provided in this application, showing a comparison of the 24-hour load rate curves before and after adjustment;

[0124] Figure 11 This is a simulation stage provided in this application, showing a comparison of the output of each resource before and after adjustment; Figure 11 (a) is a comparison chart of photovoltaic power output. Figure 11 (b) is a comparison chart of energy storage output. Figure 11 (c) is a comparison chart of the charging pile output;

[0125] Figure 12 This is a simulation stage diagram showing the forward heavy overload control details provided in the embodiments of this application; Figure 12 (a) is a detailed diagram of load rate control. Figure 12 (b) is a detailed diagram of energy storage charging and discharging regulation;

[0126] Figure 13 This is a simulation stage diagram with detailed reverse overload control provided in the embodiments of this application; Figure 13 (a) is a detailed diagram of load rate control. Figure 13 (b) is a detailed diagram of energy storage charging and discharging regulation. Figure 13 (c) is a detailed diagram of photovoltaic power output regulation. Detailed Implementation

[0127] To facilitate understanding by those skilled in the art, the present application will be further described below in conjunction with embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present application.

[0128] To address the aforementioned technical problems, this application proposes the following... Figure 1 The illustrated method for coordinated management and high-quality power supply of photovoltaic-storage-charging networks under limited measurement conditions includes:

[0129] Step S101: Obtain system operating conditions and aggregated power;

[0130] The system operating conditions in this application include voltage operating conditions and transformer load operating conditions, and the corresponding determination process is as follows:

[0131] First, operational condition assessment information is collected from a limited number of monitoring points. When installing photovoltaic (PV), energy storage, and charging piles in a low-voltage distribution network, corresponding monitoring equipment (with data uploading and command receiving capabilities) is typically installed. Therefore, the limited monitoring points in this invention are the grid-connected nodes of the PV, energy storage, and charging piles, as well as the transformer. The operational condition assessment information includes the transformer's output power and the voltage at the PV grid-connected point. The output power of the transformer includes the active power output of the transformer. Transformer output active power .

[0132] Based on the above operating condition assessment information, the system operating condition can be determined as follows:

[0133] First, based on the transformer's output power, the transformer's load operating condition can be determined. The transformer's load operating condition includes normal operating condition and abnormal operating condition. Abnormal operating condition includes forward overload and reverse overload. Based on the transformer's output power, the transformer load rate can be determined, as shown in equation (1):

[0134] (1)

[0135] In the formula, For the load factor of the transformer, For transformer port capacity;

[0136] Then, based on the transformer load rate, the transformer load operating condition is determined, as shown in equation (2):

[0137] (2)

[0138] In the formula, and These are the lower and upper bounds of the transformer load rate, respectively.

[0139] Furthermore, this application is based on the voltage of the photovoltaic grid connection point. The voltage operating conditions are determined by the following method: normal voltage operating conditions and abnormal voltage operating conditions. Abnormal voltage operating conditions include node voltage exceeding the lower limit and node voltage exceeding the upper limit. The specific determination process is shown in equation (3).

[0140] (3)

[0141] In the formula, and These are the lower and upper voltage limits for the photovoltaic grid connection point, respectively.

[0142] The aggregated power in this application includes the total photovoltaic power that can be generated. Total maximum chargeable and dischargeable power of energy storage Total maximum adjustable power of charging pile The process of determining it is as follows:

[0143] Obtain electrical information from a limited number of monitoring points, including the photovoltaic power generation capacity. Maximum charging and discharging power of energy storage and the maximum adjustable power of the charging station Then, the electrical information from each monitoring point is summarized by type to obtain the total photovoltaic power generation capacity. Total maximum chargeable and dischargeable power of energy storage Total maximum adjustable power of charging pile As shown in equation (4):

[0144] (4)

[0145] In the formula, , and These represent the number of photovoltaic, energy storage, and charging piles within the transformer substation area.

[0146] Step S102: Based on the system operating conditions, determine whether to update the power control command;

[0147] If so, proceed to step S103;

[0148] Here, it is necessary to determine whether to update the power control command based on whether the system is operating under abnormal voltage or abnormal transformer load conditions. In other words, if the system is currently operating under either abnormal voltage or abnormal transformer load conditions, then the power control command needs to be updated, i.e., step S103 should be executed. If the system is not operating under any of the above abnormal conditions, then the system is operating stably and there is no need to update the power control command.

[0149] The power control commands include voltage over-limit power control commands and heavy overload power control commands. The updated power control commands differ depending on the abnormal operating conditions described in this application. When the system operates under abnormal voltage conditions, the power control command is the voltage over-limit power control command; when the system operates under transformer load power control commands, the power control command is the heavy overload power control command.

[0150] Step S103: Based on the system operating conditions, determine whether the current control level needs to be reset;

[0151] If not, proceed to step S104;

[0152] G is set as the current regulation level, with an initial value of 0. The algorithm gradually strengthens the regulation through a multi-level feedback mechanism until the abnormal operating conditions (voltage exceeding limits, heavy overload) are eliminated or the maximum regulation level 2N is reached, at which point the power regulation command is no longer updated. Since the corresponding updated power regulation command also changes when the system operating conditions change, if the newly detected abnormal operating condition type is inconsistent with the abnormal operating condition type detected in the previous round, the current regulation level needs to be reset, as shown in the following formula:

[0153] (5)

[0154] In the formula, A is the reset flag received by the algorithm, where 1 indicates a reset and 0 indicates no reset. In the first System abnormal status category upon first entry This indicates abnormal operating condition category 1, including positive heavy overload and voltage below the lower limit. This indicates abnormal operating condition category 2, including reverse overload and voltage exceeding the upper limit.

[0155] In addition to the reset determination condition in formula (5) above, the reset determination condition of this application also includes receiving a reset signal based on a fixed time scale.

[0156] In other words, as long as any of the above reset judgment conditions are met, a reset operation will be performed, that is, the current adjustment level G will be initialized, as shown in equation (6):

[0157] (6)

[0158] Step S104: Update the power control command based on the system operating conditions, the aggregated power, and the current control level;

[0159] Combination Figure 2 The following is a detailed explanation of the process of updating the power control command in this step:

[0160] Step S201: Determine whether the system is operating under abnormal voltage conditions;

[0161] If so, proceed to step S202;

[0162] If not, proceed to step S203;

[0163] Because abnormal system operating conditions may occur, such as only abnormal voltage operation, simultaneous abnormal voltage and transformer load operation, or only abnormal transformer load operation, the subsequent steps differ depending on the specific condition. Therefore, the first step is to determine whether the system is operating under abnormal voltage conditions. If so, step S202 is executed to update the power control command under abnormal voltage conditions. If not, step S203 is executed to determine whether the system is operating under abnormal transformer load conditions.

[0164] Step S202: Based on the abnormal voltage operation condition, the aggregated power, and the current control level, update the voltage over-limit power control command;

[0165] The voltage over-limit power control command includes the first active power control command and the first reactive power control command under abnormal voltage conditions. The first active power control command includes the first photovoltaic active power control command, the first energy storage active power control command and the first charging pile active power control command. The first reactive power control command includes the first photovoltaic reactive power control command and the first energy storage reactive power control command.

[0166] Because the update methods for power regulation commands differ depending on whether the node voltage is below the lower limit or above the upper limit, therefore, combining... Figure 3 Let's first explain in detail the process of updating the power control command when the node voltage falls below the lower limit:

[0167] Step S301: Determine whether the system operating condition is that the node voltage has exceeded the lower limit;

[0168] If so, proceed to step S302;

[0169] If not, proceed to step S401;

[0170] According to formula (3), it is determined whether the system operating condition is that the node voltage is below the lower limit. If the system operating condition is that the node voltage is below the lower limit, then step S302 is executed. If not, it means that the system operating condition is that the node voltage is above the upper limit. At this time, step 401 is executed, and the step of updating the power control command when the node voltage is above the upper limit is entered.

[0171] Step S302: Determine whether the current control level is less than 1;

[0172] If so, proceed to step S303;

[0173] If not, proceed to step S304;

[0174] Because the current control level is different, the update method of the corresponding power control command will also be different. If the current control level G is less than 1, it means that the corresponding control for the node voltage falling below the lower limit has just begun. At this time, step S303 is executed. If the current control level G is greater than or equal to 1, it means that multiple rounds of control for the node voltage falling below the lower limit have been performed. At this time, step S304 is executed.

[0175] Step S303: Update the first photovoltaic active power control command based on the total photovoltaic power generation capacity;

[0176] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0177] When initially regulating the node voltage below the lower limit, it is necessary to first remove the photovoltaic limitation to maintain full photovoltaic power generation. The specific process of updating the power regulation command is as follows:

[0178] Update the first photovoltaic active power control instruction based on the total photovoltaic power generation capacity. As shown in equation (7):

[0179] (7)

[0180] After receiving the first photovoltaic active power control instruction, the first photovoltaic reactive power control instruction can be updated based on the first photovoltaic active power control instruction and the current control level G, specifically as follows:

[0181] According to the first photovoltaic active power control instruction and the photovoltaic rated capacity Determine the current adjustable reactive power capacity of photovoltaic systems. As shown in equation (8):

[0182] (8)

[0183] Then, based on the current adjustable reactive power capacity of the photovoltaic system and the current control level, the first photovoltaic reactive power control instruction is determined. As shown in equation (9):

[0184] (9)

[0185] After determining the first photovoltaic active power control command and the first photovoltaic reactive power control command, step S105 can be executed.

[0186] Step S304: Determine whether the energy storage meets the discharge constraints;

[0187] If so, proceed to step S305;

[0188] When performing multiple rounds of regulation on node voltages below the lower limit, the energy storage is monitored. Subsequent operations are determined based on whether the energy storage meets the discharge constraint, as shown in the following equation:

[0189] (10)

[0190] That is, whether the state of charge (SOC) of the energy storage is greater than or equal to the lower threshold of the energy storage SOC. If SOC is greater than or equal to If the energy storage meets the discharge constraint, then the energy storage will be used first, i.e., step S305 will be executed.

[0191] If the energy storage does not meet the discharge constraint, then... In this case, the energy storage system neither charges nor discharges; instead, it directly controls the charging pile. Specifically, it updates the active power control command of the first charging pile based on the current control level G, the first control level N, and the total maximum adjustable power of the charging pile. and the first energy storage active power control command Update to zero, as shown in equation (11):

[0192] (11)

[0193] The first regulation level N is the maximum regulation level designed for a single type of resource.

[0194] Then, based on the zero-valued active power control command of the first energy storage system and the current control level, the reactive power control command of the first energy storage system can be updated, as follows:

[0195] According to the first energy storage active power control command and the rated capacity of the energy storage Calculate the current adjustable reactive capacity of energy storage. As shown in the following formula:

[0196] (12)

[0197] Then, based on the current adjustable reactive power capacity of the energy storage and the current control level G, update the first energy storage reactive power control command. As shown in the following formula:

[0198] (13)

[0199] After updating the active power control command of the first charging pile, the active power control command of the first energy storage, and the reactive power control command of the first energy storage, step S105 can be executed.

[0200] Step S305: Determine whether the current control level is greater than the first control level, where the first control level is the maximum control level set for a single type of resource;

[0201] If not, proceed to step S306;

[0202] If so, proceed to step S307;

[0203] However, to achieve better control effects, the current control level needs to be assessed again. Specifically, it needs to be determined whether the current control level G is greater than the first control level N. If the result is negative, it means that photovoltaic control cannot restore the node voltage to the normal range, and step S306 is executed. If it is greater than N, it means that after N control operations, the voltage still cannot reach the normal level, meaning that even with maximum energy storage discharge power, the control effect cannot be achieved. In this case, the control level continues to increase to begin controlling the charging pile, i.e., step S307 is executed.

[0204] Step S306: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage.

[0205] Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command.

[0206] At this point, energy storage is prioritized for regulation, and the discharge intensity is increased step by step according to the G / N ratio. That is, the first energy storage active power regulation command is updated based on the current regulation level G, the first regulation level N, and the total maximum chargeable and dischargeable power of the energy storage. As shown in the following formula:

[0207] (14)

[0208] After receiving the first active power control command for energy storage, the first active power control command can be updated according to the first active power control command and the current control level G, as shown in formulas (12)-(13). .

[0209] Step S307: Update the active power control command of the first charging pile based on the current control level, the maximum control level, and the total maximum adjustable power of the charging pile.

[0210] At this point, the charging pile reduces the charging load in stages according to the ratio of remaining power (2N-G) / N, until the voltage returns to the normal range or the charging load is completely reduced. This is based on the current control level G, the maximum control level 2N, and the total maximum adjustable power of the charging pile. Update the active power control command of the first charging pile. As shown in the following formula:

[0211] (15)

[0212] By updating the power control command as described above, when the node voltage falls below the lower limit, multiple levels of fine-grained adjustment can be performed, taking into account the priority of each resource control, so that the system operation condition can be restored to normal.

[0213] Combination Figure 4 The following is a detailed explanation of the process of updating the power regulation command when the node voltage exceeds the upper limit:

[0214] Step S401: Determine whether the current control level is less than 1;

[0215] If so, proceed to step S402;

[0216] If not, proceed to step S403;

[0217] When a node voltage exceeds its upper limit, fine-grained regulation is implemented according to three tiers: charging piles, energy storage, and photovoltaics. Therefore, the current regulation level G is first determined. If it is less than 1, the charging pile restriction is lifted, maintaining power supply without reduction, and step S402 is executed. If the determination result is negative, it indicates that energy storage or photovoltaic regulation will be implemented, and step S403 is executed.

[0218] Step S402: Update the active power control command of the first charging pile based on the maximum adjustable power of the charging pile;

[0219] First, the charging station needs to be adjusted, that is, according to the maximum adjustable power of the charging station. To update the active power control instructions of the first charging pile. As shown in the following formula:

[0220] (16)

[0221] Step S403: Determine whether the energy storage meets the charging constraints;

[0222] If so, proceed to step S404;

[0223] If not, proceed to step S407;

[0224] At this point, it is necessary to determine whether the energy storage meets the charging constraints. If the energy storage SOC meets the charging constraints, as shown in the following formula:

[0225] (17)

[0226] In the formula, If the threshold value is the upper limit of the energy storage state of charge (SOC), then step 404 is executed. If the energy storage SOC does not meet the charging constraints, then step S407 is executed.

[0227] Step S404: Determine whether the current control level is greater than the first control level;

[0228] If not, proceed to step S405;

[0229] If so, proceed to step S406;

[0230] Different current control levels correspond to different power control command methods. If the judgment result is negative, energy storage is prioritized for control, i.e., step S405 is executed. If the judgment result is positive, it means that the energy storage has reached its maximum charging power and still cannot achieve the control effect, in which case step S406 is executed.

[0231] Step S405: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage.

[0232] Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command.

[0233] Prioritize the use of energy storage, and gradually increase the charging intensity according to the G / N ratio. That is, update the first energy storage active power control command based on the current control level G, the first control level N, and the total maximum chargeable and dischargeable power of the energy storage. As shown in the following formula:

[0234] (18)

[0235] After receiving the first active power control command for energy storage, the first reactive power control command for energy storage can be updated based on the first active power control command and the current control level G. The specific process is as follows:

[0236] Using formula (12), the current reactive power adjustable capacity of energy storage can be calculated. Then, based on the adjustable reactive power capacity... Update the first energy storage reactive power control command according to the current control level. As shown in the following formula:

[0237] (19)

[0238] Step S406: Update the first photovoltaic active power control instruction based on the current control level, the maximum control level, and the total photovoltaic power generation capacity;

[0239] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0240] At this point, photovoltaic (PV) power is regulated. PV output is reduced in stages according to the ratio of remaining power (2N-G) / N until the voltage returns to normal or the PV output is completely reduced. Specifically, the first PV active power regulation command is updated based on the current regulation level G, the maximum regulation level 2N, and the total renewable PV power. As shown in the following formula:

[0241] (20)

[0242] Then, based on the first photovoltaic active power control command and the current control level G, the first photovoltaic reactive power control command is updated, specifically as follows:

[0243] The current adjustable reactive power capacity of photovoltaic power is calculated using formula (8). Then, based on the adjustable reactive power capacity and the current control level, the first photovoltaic reactive power control instruction is updated and obtained. As shown in the following formula:

[0244] (twenty one)

[0245] This completes the updating of power control commands at different control levels when energy storage meets charging constraints.

[0246] Step S407: Based on the current control level, the first control level, and the total photovoltaic power generation, update the first photovoltaic active power control command and update the first energy storage active power control command to zero;

[0247] Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction;

[0248] Based on the first energy storage active power control command which is zero and the current control level, update the first energy storage reactive power control command.

[0249] If the State of Charge (SOC) is insufficient, the energy storage system will neither charge nor discharge, and will directly regulate the photovoltaic (PV) system, reducing power output in stages according to the ratio of remaining power (NG) / N, until the voltage returns to the normal range or the PV output is completely reduced. This means that based on the current regulation level G, the first regulation level N, and the total renewable PV power, the first PV active power regulation command will be updated. and the first energy storage active power control command Updated to zero, as shown in the following formula:

[0250] (twenty two)

[0251] After obtaining the first photovoltaic active power control command, the first photovoltaic reactive power control command can be calculated using formulas (8) and (20). The first energy storage reactive power control command can be calculated using formulas (12) and (18).

[0252] In addition, for equipment safety and to reflect the tiered control, the active power output commands of each resource (photovoltaic, energy storage, and charging) need to meet upper and lower power limits, as shown below:

[0253] (twenty three)

[0254] Based on the aforementioned steps, the specific methods for updating the power control command when the node voltage exceeds the lower limit and the node voltage exceeds the upper limit can be obtained.

[0255] Step S203: Determine whether the system is operating under abnormal transformer load conditions;

[0256] If so, proceed to step S204;

[0257] If not, proceed to step S105;

[0258] At this point, if step S202 was not executed and step S203 was executed directly, it means that the abnormal operating condition of the system does not involve abnormal voltage operation, and voltage regulation only needs to maintain the current output. However, it is necessary to further determine whether the system operating condition is an abnormal transformer load operation. If so, step S204 is executed to calculate the update of the power regulation command under the abnormal transformer load operation condition. If not, the current processing continues, and step S105 is executed.

[0259] If step S202 has been executed, it indicates that there is an abnormal voltage operation in the system. However, to ensure that there is no abnormal transformer load operation, step S203 needs to be executed to determine whether there is such an operation. If so, step S204 is executed to calculate the update of the power control command under the abnormal transformer load operation. If not, the current processing continues, and step S105 is executed.

[0260] Step S204: Based on the abnormal operating conditions of the transformer load, the aggregated power, and the current control level, update the heavy overload power control command;

[0261] The heavy overload power control command includes a second active power control command and a second reactive power control command under abnormal operating conditions of transformer load; the second active power control command includes a second photovoltaic active power control command, a second energy storage active power control command, and a second charging pile active power control command, and the reactive power control command includes a second photovoltaic reactive power control command and a second energy storage reactive power control command.

[0262] Because abnormal operating conditions of the transformer load include both forward heavy overload and reverse heavy overload, the corresponding power control command update methods differ under these two different conditions. (Combined with...) Figure 5 The update process of power control commands under positive heavy overload conditions is explained in detail, specifically as follows:

[0263] Step S501: Determine whether the abnormal operating condition of the transformer load is a positive heavy overload;

[0264] If so, proceed to step S502;

[0265] Here, it is necessary to determine the abnormal operating condition of the load at the station edge. If it is a positive heavy overload, then step S502 can be executed. If it is not a positive heavy overload, then it is a reverse heavy overload, and step S601 can be executed.

[0266] Step S502: Determine whether the current control level is less than 1;

[0267] If so, proceed to step S503;

[0268] If not, proceed to step S504;

[0269] First, the current control level G is determined. If the current control level is less than 1, it means that a positive heavy overload has just occurred. In this case, the update power command operation in step S503 is executed. If the determination result is negative, the update power command operation in step S504 is executed.

[0270] Step S503: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity;

[0271] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0272] When a positive heavy overload occurs, the photovoltaic (PV) limit is lifted to maintain full PV power generation. Specifically, the second PV active power control command is updated based on the total PV power output. As shown in the following formula:

[0273] (twenty four)

[0274] After receiving the second photovoltaic active power control instruction, the second photovoltaic reactive power control instruction can be updated based on the second photovoltaic active power control instruction and the current control level. The specific process is as follows:

[0275] First, based on the second photovoltaic active power regulation instruction and the photovoltaic rated capacity... Calculate the current adjustable reactive power capacity of photovoltaic systems. As shown in the following formula:

[0276] (25)

[0277] Then, based on the current reactive power control capacity and current control level of the photovoltaic system, the second photovoltaic reactive power control instruction is updated. As shown in the following formula:

[0278] (26)

[0279] After receiving the second photovoltaic active power control command and the second photovoltaic reactive power control command, you can directly proceed to step S105 to modify the power control command.

[0280] Step S504: Determine whether the energy storage meets the discharge constraint;

[0281] If so, proceed to step S905;

[0282] If not, proceed to step S908;

[0283] At this point, it means that other power control commands need to be updated to restore the system to normal. However, it is necessary to first determine whether the energy storage meets the discharge constraints, and then take the corresponding update method based on the result of the determination. If the determination result is yes, then the operation of prioritizing the use of energy storage in step S505 is executed; if the determination result is no, then the charging pile control in step S508 is executed.

[0284] Step S505: Determine whether the current control level is greater than the first control level;

[0285] If not, proceed to step S506;

[0286] If so, proceed to step S507;

[0287] When performing energy storage regulation, the current regulation level needs to be judged again. If the current regulation level is higher than the first regulation level, it means that the energy storage has reached its maximum discharge power and still cannot achieve the regulation effect. In this case, the charging pile regulation in step S507 is executed. If the judgment result is negative, the energy storage regulation operation in step S506 is executed.

[0288] Step S506: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage.

[0289] Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command;

[0290] At this point, energy storage is prioritized, and the discharge intensity is increased step by step according to the G / N ratio. That is, the second energy storage active power control command is updated based on the total maximum chargeable and dischargeable power of the energy storage. As shown in the following formula:

[0291] (27)

[0292] After receiving the second active power control command for energy storage, the second reactive power control command can be updated based on the second active power control command and the current control level, specifically as follows:

[0293] According to the second energy storage active power control command and the rated capacity of energy storage Calculate the current adjustable reactive capacity of energy storage. As shown in the following formula:

[0294] (28)

[0295] Then, based on the current adjustable reactive power capacity of the energy storage and the current control level G, the reactive power control command of the second energy storage is updated. As shown in the following formula:

[0296] (29)

[0297] Then step S105 can be executed to modify the above-mentioned second energy storage active power control command and second energy storage reactive power control command.

[0298] Step S507: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile, the maximum control level, and the current control level;

[0299] Currently, the charging piles are being regulated. At this time, the charging load is being reduced in stages according to the ratio of remaining power (2N-G) / N until the load rate returns to the normal range or the charging load is completely reduced. This involves updating the active power regulation command for the second charging pile based on the total maximum adjustable power, maximum regulation level, and current regulation level of the charging pile. As shown in the following formula:

[0300] (30)

[0301] After receiving the active power control command for the second charging pile, step S105 can be executed to update the active power control command for the second charging pile.

[0302] Step S508: Based on the total maximum adjustable power of the charging pile, the current control level and the first control level, update the active power control command of the second charging pile and update the active power control command of the second energy storage to zero;

[0303] Based on the second energy storage active power control command which is zero, update the second energy storage reactive power control command.

[0304] If the energy storage SOC is insufficient, the energy storage will neither charge nor discharge, and regulation will begin directly from the charging pile. The charging pile will reduce the charging load in stages according to the ratio of remaining power (NG) / N until the load rate returns to the normal range or the charging load is completely reduced. That is, based on the total maximum adjustable power of the charging pile, the current regulation level G, and the first regulation level N, the active power regulation command of the second charging pile will be updated. And will issue the second energy storage active power control command Updated to zero, as shown in the following formula:

[0305] (31)

[0306] After receiving the second active energy storage control command, the second reactive energy storage control command can be calculated according to formulas (28) and (29) based on the current control level G.

[0307] Execute step S105 to correct the active power control command for the second charging pile, the active power control command for the second energy storage, and the reactive power control command for the second energy storage obtained at this time.

[0308] Combination Figure 6 This section will provide a detailed explanation of the power control command update process under reverse heavy overload conditions, specifically as follows:

[0309] Step S601: Determine whether the current control level is less than 1;

[0310] If so, proceed to step S602;

[0311] If not, proceed to step S603;

[0312] At this point, the current control level must also be judged. If the current control level is less than 1, it means that a reverse overload has just occurred. In this case, the charging pile control in step S602 is executed. If the judgment result is negative, the control in step S603 is executed.

[0313] Step S602: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile;

[0314] At this point, the charging pile restrictions are lifted, maintaining the charging pile's load without reduction. Specifically, the active power control command for the second charging pile is updated based on the total maximum adjustable power of the charging piles. As shown in the following formula:

[0315] (32)

[0316] Step S105 is executed to correct the active power control command for the second charging pile. If the load rate returns to normal, the current power control command is maintained; if it is still a reverse overload, the corresponding update is executed.

[0317] Step S603: Determine whether the energy storage meets the charging constraints;

[0318] If so, proceed to step S604;

[0319] If not, proceed to step S607;

[0320] At this point, the energy storage needs to be tested. If the energy storage SOC can meet the charging constraints, the update operation in step S604 is executed. If the energy storage cannot meet the charging constraints, the update operation in step S607 is executed.

[0321] Step S604: Determine whether the current control level is greater than the first control level;

[0322] If not, proceed to step S605;

[0323] If so, proceed to step S606;

[0324] When energy storage meets charging constraints, the power control command update method varies depending on the current control level. If the judgment result of this step is negative, it means that the priority update operation of energy storage in step S605 is executed. If the judgment result of this step is positive, it means that even if energy storage reaches the maximum charging power, it still cannot achieve the control effect, and the update operation of photovoltaic power in step S606 is executed.

[0325] Step S605: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage, the current control level, and the first control level;

[0326] Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command;

[0327] This step prioritizes the use of energy storage, gradually increasing the charging intensity according to the G / N ratio. Once the load rate returns to a normal range, the regulation ends; that is, based on the total maximum chargeable / dischargeable power of the energy storage, the current regulation level G, and the first regulation level N, the second energy storage active power regulation command is updated. As shown in the following formula:

[0328] (33)

[0329] Then, based on the active power control command of the second energy storage system and the current control level, the reactive power control command of the second energy storage system is updated, specifically as follows:

[0330] First, based on the second energy storage active power control command and the current control level G, the second energy storage reactive power control command is calculated using formulas (28) and (29). .

[0331] Then, perform step S105 to modify the second energy storage active power control command and the second energy storage reactive power control command.

[0332] Step S606: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity, the current control level, and the maximum control level;

[0333] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0334] At this point, the photovoltaic (PV) output is reduced in stages according to the ratio of remaining power (2N-G) / N until the load factor returns to the normal range or the PV output is completely reduced. That is, the second PV active power control command is updated based on the total PV power generation capacity, the current control level G, and the maximum control level 2N. As shown in the following formula:

[0335] (34)

[0336] Then, based on the second photovoltaic active power control instruction and the current control level G, the second photovoltaic reactive power control instruction is updated, specifically as follows:

[0337] Based on the second photovoltaic active power control command and the current control level G, the second photovoltaic reactive power control command is calculated using formulas (25) and (26).

[0338] Perform step S105 to modify the second photovoltaic active power control command and the second photovoltaic reactive power control command accordingly.

[0339] Step S607: Based on the total photovoltaic power generation capacity, the current control level, and the first control level, determine the second photovoltaic active power control command and update the second energy storage active power control command to zero;

[0340] Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction;

[0341] Based on the second energy storage active power control command which is zero, update the second energy storage reactive power control command.

[0342] At this point, the energy storage SOC is insufficient, meaning the energy storage neither charges nor discharges. Regulation begins directly from the photovoltaic (PV) system, with power reduction implemented in stages according to the ratio of remaining power (NG) / N, until the load factor returns to normal or PV output is completely reduced. Specifically, based on the total renewable PV power, the current regulation level G, and the first regulation level N, the second PV active power regulation command is determined. And will issue the second energy storage active power control command Updated to zero, as shown in the following formula:

[0343] (35)

[0344] Then, based on the second photovoltaic active power control command and the current control level G, the second photovoltaic reactive power control command is updated using formulas (25) and (26);

[0345] Based on the second energy storage active power control command and the current control level G, the second energy storage reactive power control command is updated using formulas (26) and (27).

[0346] Then, the control command updated in this step is used to perform the correction operation in step S105.

[0347] It should be noted that under abnormal operating conditions of the transformer load, the received instructions must also meet the upper and lower power limits:

[0348] (36)

[0349] Step S205: Overwrite the voltage over-limit power control command with the heavy overload power control command, and execute step S105.

[0350] Since the core logic of power regulation is to prioritize equipment safety and then pursue stable operating indicators, heavy overload directly threatens the physical safety of equipment, while voltage exceeding limits has a greater impact on operational quality. These two have different priorities. Therefore, if the system simultaneously experiences abnormal voltage operation and abnormal transformer load operation, heavy overload regulation will be implemented first, and voltage regulation will not be executed.

[0351] It should be noted that, regardless of whether the voltage is abnormal or the transformer load is abnormal, when updating a certain power control command, although other control commands are not updated at the same time, the control commands after the last update will be maintained, and the power control command that has been updated will be sent together to step S105 for correction.

[0352] Step S105: Modify the power control command to obtain a modified power control command;

[0353] Based on the aforementioned logical judgment, the corresponding power control command needs to be modified, as follows:

[0354] When the voltage is abnormal or the transformer load is abnormal, the first and second energy storage active power control commands are modified. The energy storage active power control commands need to conform to the current energy storage state of charge. If the energy storage SOC is lower than the threshold and the control command is to discharge, the modified energy storage control command is to neither charge nor discharge. If the energy storage SOC is higher than the threshold and the control command is to charge, the modified energy storage control command is to neither charge nor discharge, as shown in the following formula (37):

[0355] (37)

[0356] In the formula, This is the revised active power command for energy storage. The original active energy storage command (either the first active energy storage control command or the second active energy storage control command) is the corrected active energy storage command.

[0357] Furthermore, if the power regulation command for energy storage is higher than the corresponding maximum power, then the regulation command for that type of equipment is corrected to the corresponding maximum power. If the regulation command for photovoltaic, energy storage, and charging piles is higher than the corresponding maximum power, then the regulation command for that type of equipment is corrected to the corresponding minimum power. This is illustrated in the following formula:

[0358] (38)

[0359] (39)

[0360] (40)

[0361] In the formula, , and These are the revised active power control instructions for energy storage, photovoltaics, and charging piles, respectively.

[0362] Furthermore, the first reactive power control command under abnormal voltage operating conditions will not be modified accordingly. The second reactive power control command under abnormal transformer load operating conditions will be modified accordingly.

[0363] After receiving the reactive power control instructions for photovoltaic and energy storage, the instructions need to be modified according to the actual reactive load characteristics and magnitude of the distribution area to avoid overcompensation. Under forward heavy overload conditions, if it is a capacitive load, photovoltaic and energy storage are prohibited from generating reactive power; if it is an inductive load, the reactive power generated by photovoltaic and energy storage is limited to not exceeding the reactive load demand to avoid overcompensation. Under reverse heavy overload conditions, if it is an inductive load, photovoltaic and energy storage are prohibited from absorbing reactive power; if it is a capacitive load, the reactive power absorbed by photovoltaic and energy storage is limited to not exceeding the reactive load demand to avoid overcompensation. The modification instructions are shown in the following formulas (41)-(42):

[0364] (41)

[0365] (42)

[0366] Step S106: Assign the corrected power control command and perform corresponding control;

[0367] The revised active / reactive power commands for photovoltaic, energy storage, and charging piles will be allocated according to the equipment capacity ratio:

[0368] (43)

[0369] In the formula, and The first Taiwan's solar power active and reactive power control commands, and The first Taiwan's energy storage system's active and reactive power control commands. For the first Active power control commands for the charging piles.

[0370] Step S107: Determine whether the current control level has reached the maximum control level;

[0371] If so, then stop updating the power control command;

[0372] If not, increment the current control level by 1 and proceed to step S101.

[0373] After each adjustment, the current adjustment level must be judged. If the current adjustment level G is greater than or equal to 2N, it means that even if the power adjustment command is updated, the system's operating condition will not return to normal or will change. In this case, the operation of updating the power adjustment command ends. If the judgment result is negative, it means that the next round of adjustment can be carried out. In this case, the current adjustment level is incremented by 1 so that when the system operating condition in the next round is the same as the current system operating condition, the corresponding power adjustment command can be updated.

[0374] Simulation Experiment

[0375] This invention utilizes a simulation model built based on the following facility parameters for verification. The simulation parameters are shown in Table 1:

[0376] ;

[0377] Load, photovoltaic data, and charging load data, such as Figures 7-9 As shown:

[0378] (1) Display of the effect of regulation throughout the day

[0379] The comparison chart of the 24-hour load rate curves of the transformer substation before and after regulation is shown below. Figure 10 As shown, after approximately 6 PM, the photovoltaic (PV) system ceases operation, making the distribution area prone to forward heavy overload conditions. Conversely, during midday, high solar intensity and increased PV output can easily lead to reverse heavy overload conditions. After regulation, the heavy overload situation was significantly improved. In each regulation cycle (15 minutes), when the load rate is detected to exceed the threshold, regulation measures are immediately triggered to restore the load rate to the normal range. This current command is maintained until the end of the regulation cycle, triggering a reset and initiating a new regulation cycle for re-evaluation and regulation. The figure demonstrates that the logic control algorithm significantly shortens the time when the load rate exceeds the threshold, effectively improving the reliability of the distribution network.

[0380] Comparison of the output before and after resource regulation, for example Figure 11 As shown, under positive heavy overload conditions, the algorithm will first regulate the energy storage to gradually increase the discharge, such as the energy storage... SOC If the forward heavy overload cannot be resolved even after reaching the lower limit or the maximum discharge power of the energy storage, the charging load should be gradually reduced. Under reverse heavy overload conditions, the energy storage should be gradually increased in stages. SOC If the reverse overload cannot be resolved even after reaching the upper limit or the maximum charging power of energy storage, the photovoltaic power will be gradually reduced.

[0381] 2) Details of regulation and control

[0382] Each complete control cycle (i.e., reset interval) is 15 minutes, and the logic control algorithm runs ten rounds per cycle, meaning one round of the logic algorithm lasts 90 seconds. At the beginning of each control cycle, the algorithm is fed with information such as the current cycle's load status, predicted photovoltaic output, and charging load to make logical judgments and control operations. Furthermore, within each control cycle, the logic algorithm updates the transformer load rate, node voltages, and energy storage state of charge in real time during each round of operation, thereby updating the appropriate control operations based on the real-time status.

[0383] 1) Positive heavy overload

[0384] The typical control cycle from 20:00 to 20:15 is used to illustrate the control details of positive heavy overload, such as... Figure 12 As shown:

[0385] At 20:00, a load factor of 0.93 was detected, exceeding the threshold of 0.8, thus triggering regulation. The energy storage discharge rate was gradually increased in stages according to a 1 / 3, 2 / 3, and 3 / 3 ratio until the load factor returned to normal. Since the current reactive load is capacitive, to avoid overcompensation, the reactive power output commands for both energy storage and photovoltaic systems were corrected to 0. Figure 12 As shown in (a) and (b), when the energy storage discharge power reaches 6.67kW, the load rate drops to around 0.71, returning to the normal range. Afterwards, all resources maintain their current commands until 20:15, when a new control cycle begins. The energy storage is reset, and information such as the load status, predicted photovoltaic output, and charging load for the new control cycle is input to the algorithm for a new round of logical judgment and control operations.

[0386] 2) Reverse heavy overload

[0387] The typical control cycle from 10:15 to 10:30 is used to illustrate the control details of reverse heavy overload, such as... Figure 13 As shown:

[0388] At 10:15, a load factor of approximately -1.05 was detected, below the threshold of -0.8, thus triggering regulation. The energy storage charging intensity was gradually increased in stages, at 1 / 3, 2 / 3, and 3 / 3 ratios, until the load factor returned to the normal range. Furthermore, since the reactive load in the current regulation cycle is inductive, to avoid overcompensation, the reactive power commands for both photovoltaic and energy storage were corrected to 0. Figure 13 (a) Figure 13 (b) It can be seen that when the maximum charging power of energy storage reaches 10kW, the load rate rises to -0.71 and returns to the normal range. After that, all resources maintain the current command unchanged.

[0389] However, around 10:23, the charging operation during the previous control cycle caused energy storage... SOCThe load factor has been reached, so the energy storage system stopped charging, causing it to drop back to around -1.05. At this point, the energy storage system can no longer charge, so the installation of photovoltaic systems will be phased out in stages at 1 / 3, 2 / 3, and 3 / 3 ratios. Figure 13 As shown in (a) and (c), after the output of each of the four photovoltaic systems was reduced by one-third, the load factor rose to around -0.52, returning to the normal range. The current output of each resource was maintained until 10:30, when a new control cycle began. A reset operation was performed, the photovoltaic system was unrestricted, and information such as the load situation, predicted photovoltaic output, and charging load for the new control cycle was input into the algorithm for a new round of logical judgment and control operations.

[0390] In summary, the method proposed in this application, through multi-level regulation and feedback correction, can balance the control of distribution network voltage and load rate under limited measurement information. Simultaneously, by setting the regulation priorities for resources such as photovoltaics, energy storage, and charging piles, the utilization rate of photovoltaics is improved.

[0391] The above embodiments are preferred implementations of this application. In addition, this application can be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this application.

[0392] To facilitate understanding by those skilled in the art of the improvements made by this application compared to the prior art, some of the accompanying drawings and descriptions have been simplified, and for clarity, some other elements have been omitted from this application. Those skilled in the art should realize that these omitted elements may also constitute the content of this application.

Claims

1. A method for coordinated management and high-quality power supply of photovoltaic-storage-charging systems under limited measurement conditions in distribution networks, characterized in that: include: Step S101: Obtain system operating conditions and aggregated power; Step S102: Based on the system operating conditions, determine whether to update the power control command; If so, proceed to step S103; Step S103: Based on the system operating conditions, determine whether the current control level needs to be reset; If not, proceed to step S104; Step S104: Based on the system operating conditions, the aggregated power, and the current control level, update the power control command, which includes a voltage over-limit power control command and a heavy overload power control command; Step S105: Modify the power control command to obtain a modified power control command; Step S106: Assign the corrected power control command and perform corresponding control; Step S107: Determine whether the current control level has reached the maximum control level; If so, then end the update of the power control command; If not, increment the current control level by 1 and proceed to step S101; The step of updating the power control command based on the system operating conditions, the aggregated power, and the current control level includes: Step S201: Determine whether the system is operating under abnormal voltage conditions; the abnormal voltage conditions include node voltages falling below the lower limit and node voltages falling above the upper limit. If so, proceed to step S202; If not, proceed to step S203; Step S202: Based on the abnormal voltage operating condition, the aggregated power, and the current control level, update the voltage over-limit power control instruction; the voltage over-limit power control instruction includes a first active power control instruction and a first reactive power control instruction under the abnormal voltage operating condition; the first active power control instruction includes a first photovoltaic active power control instruction, a first energy storage active power control instruction, and a first charging pile active power control instruction, and the first reactive power control instruction includes a first photovoltaic reactive power control instruction and a first energy storage reactive power control instruction; Step S203: Determine whether the system operating condition is an abnormal transformer load operating condition; the abnormal transformer load operating condition includes forward heavy overload and reverse heavy overload; If so, proceed to step S204; If not, proceed to step S105; Step S204: Based on the abnormal operating conditions of the transformer load, the aggregated power, and the current control level, update the heavy overload power control command; the heavy overload power control command includes a second active power control command and a second reactive power control command under the abnormal operating conditions of the transformer load; the second active power control command includes a second photovoltaic active power control command, a second energy storage active power control command, and a second charging pile active power control command, and the second reactive power control command includes a second photovoltaic reactive power control command and a second energy storage reactive power control command; Step S205: Overwrite the voltage over-limit power control command with the heavy overload power control command, and execute step S105.

2. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 1, characterized in that, The process for determining the polymerization power is as follows: Electrical information is collected from a limited number of monitoring points, including grid-connected nodes of photovoltaic, energy storage, and charging piles, as well as transformers; the electrical information includes the power generation capacity of photovoltaic, the maximum charging and discharging power of energy storage, and the maximum adjustable power of charging piles. The electrical information is aggregated to obtain aggregated power, which includes the total photovoltaic power generation capacity, the total maximum chargeable and dischargeable power of energy storage, and the total maximum adjustable power of the charging pile.

3. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution networks according to claim 2, characterized in that, The system operating conditions include voltage operating conditions and transformer load operating conditions. The process for determining the system operating conditions is as follows: Collect operating condition assessment information from a limited number of monitoring points, including the output power of the transformer and the voltage at the photovoltaic grid connection point; Based on the output power of the transformer, the operating conditions of the transformer load are determined, including normal operating conditions and abnormal operating conditions. Based on the voltage at the photovoltaic grid connection point, the voltage operating conditions are determined, including normal voltage operating conditions and abnormal voltage operating conditions.

4. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 3, characterized in that, The step of determining whether to update the power control command based on the system operating conditions includes: Determine whether the system is operating under abnormal voltage or abnormal transformer load conditions. If so, update the power control command and execute step S103; If not, maintain the current output.

5. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 4, characterized in that, The step of updating the voltage over-limit power control command based on the abnormal voltage operating condition, the aggregated power, and the current control level includes: Step S301: Determine whether the abnormal voltage operation condition is due to the node voltage falling below the lower limit; If so, proceed to step S302; Step S302: Determine whether the current control level is less than 1; If so, proceed to step S303; If not, proceed to step S304; Step S303: Update the first photovoltaic active power control command based on the total photovoltaic power generation capacity; Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction; Step S304: Determine whether the energy storage meets the discharge constraints; If so, proceed to step S305; Step S305: Determine whether the current control level has reached the first control level, where the first control level is the maximum control level set for a single type of resource; If not, proceed to step S306; If so, proceed to step S307; Step S306: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage. Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command. Step S307: Update the active power control command of the first charging pile based on the current control level, the maximum control level, and the total maximum adjustable power of the charging pile.

6. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 5, is characterized in that, If the judgment result of step S304 is negative, then the following step S308 is executed: Step S308: Based on the current control level, the first control level, and the total maximum adjustable power of the charging pile, update the first charging pile active power control command and update the first energy storage active power control command to zero; Based on the first energy storage active power control command which is zero and the current control level, update the first energy storage reactive power control command.

7. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 6, characterized in that, If the judgment result of step S301 is negative, then the following steps are executed: Step S401: Determine whether the current control level is less than 1; If so, proceed to step S402; If not, proceed to step S403; Step S402: Update the active power control command of the first charging pile based on the maximum adjustable power of the charging pile; Step S403: Determine whether the energy storage meets the charging constraints; If so, proceed to step S404; If not, proceed to step S407; Step S404: Determine whether the current control level has reached the first control level; If not, proceed to step S405; If so, proceed to step S406; Step S405: Update the first energy storage active power control command based on the current control level, the first control level, and the total maximum chargeable and dischargeable power of the energy storage. Based on the first energy storage active power control command and the current control level, update the first energy storage reactive power control command. Step S406: Update the first photovoltaic active power control instruction based on the current control level, the maximum control level, and the total photovoltaic power generation capacity; Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction; Step S407: Based on the current control level, the first control level, and the total photovoltaic power generation, update the first photovoltaic active power control command and update the first energy storage active power control command to zero; Based on the first photovoltaic active power control instruction and the current control level, update the first photovoltaic reactive power control instruction; Based on the first energy storage active power control command which is zero and the current control level, update the first energy storage reactive power control command.

8. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 7, characterized in that, The update of the heavy overload power control command based on the abnormal operating conditions of the transformer load, the aggregated power, and the current control level includes: Step S501: Determine whether the abnormal operating condition of the transformer load is a positive heavy overload; If so, proceed to step S502; Step S502: Determine whether the current control level is less than 1; If so, proceed to step S503; If not, proceed to step S504; Step S503: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity; Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction; Step S504: Determine whether the energy storage meets the discharge constraint; If so, proceed to step S505; If not, proceed to step S508; Step S505: Determine whether the current control level has reached the first control level; If not, proceed to step S506; If so, proceed to step S507; Step S506: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage. Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command. Step S507: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile, the maximum control level, and the current control level; Step S508: Based on the total maximum adjustable power of the charging pile, the current control level and the first control level, update the active power control command of the second charging pile and update the active power control command of the second energy storage to zero; Based on the second energy storage active power control command which is zero, update the second energy storage reactive power control command.

9. The method for coordinated control and high-quality power supply of photovoltaic-storage-charging under limited measurement of distribution network as described in claim 8, characterized in that, If the judgment result of step S501 is negative, then the following steps are executed: Step S601: Determine whether the current control level is less than 1; If so, proceed to step S602; If not, proceed to step S603; Step S602: Update the active power control command of the second charging pile based on the total maximum adjustable power of the charging pile; Step S603: Determine whether the energy storage meets the charging constraints; If so, proceed to step S604; If not, proceed to step S607; Step S604: Determine whether the current control level has reached the first control level; If not, proceed to step S605; If so, proceed to step S606; Step S605: Update the second energy storage active power control command based on the total maximum chargeable and dischargeable power of the energy storage, the current control level, and the first control level; Based on the second energy storage active power control command and the current control level, update the second energy storage reactive power control command. Step S606: Update the second photovoltaic active power control command based on the total photovoltaic power generation capacity, the current control level, and the maximum control level; Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction; Step S607: Based on the total photovoltaic power generation capacity, the current control level, and the first control level, determine the second photovoltaic active power control command and update the second energy storage active power control command to zero; Based on the second photovoltaic active power control instruction and the current control level, update the second photovoltaic reactive power control instruction; Based on the second energy storage active power control command which is zero and the current control level, update the second energy storage reactive power control command.

Images