Power distribution network balancing scheduling method and system considering three-phase balance of nodes

Abstract

This invention relates to the field of low-voltage distribution network technology, specifically to a distribution network balanced dispatching method and system that considers the three-phase balance of nodes. The method includes: (1) iteratively optimizing the phase sequence configuration scheme of the current distribution area to obtain the optimal phase sequence configuration scheme with the minimum comprehensive operating cost score of the current distribution area; the calculation method of the comprehensive operating cost score includes: determining the phase line to which each node in the current distribution area belongs based on the phase sequence configuration scheme, and calculating the power change of each phase in combination with the power change of each node; determining each waveform transformation interval of each phase based on the power change of each phase, calculating the fluctuation penalty characteristic index of each waveform transformation interval, and summing the fluctuation penalty characteristic index of all waveform transformation intervals of all phases to obtain the comprehensive operating cost score of the phase sequence configuration scheme; (2) controlling the nodes whose phase line affiliation changes to switch their respective phase lines according to the optimal phase sequence configuration scheme.

Description

Technical Field

[0001] This invention relates to the field of low-voltage distribution network technology, and specifically to a distribution network balancing dispatching method and system that considers the three-phase balance of nodes. Background Technology

[0002] Distribution network typically refers to low-voltage distribution network. In low-voltage distribution networks, the non-uniform connection of a high proportion of single-phase residential distributed photovoltaic equipment and single-phase equipment (such as electric heating, high-power air conditioners, etc.) can lead to frequent three-phase imbalance and power backflow in the distribution transformer area. To solve this problem, the common practice in existing technology is to detect the three-phase transient phase current range of the transformer in the low-voltage distribution network area. When the transient range exceeds a set threshold, the single-phase load node on the heavily loaded phase is immediately disconnected or switched by an automatic phase-switching switch installed on the distribution transformer area.

[0003] This approach only considers the instantaneous current range. As long as the instantaneous current range exceeds the set threshold, the automatic phase-switching switch will be switched. However, in actual operation, whether it is a short-term spike caused by noise or a long-term change in load power, the automatic phase-switching switch will be triggered, causing the automatic phase-switching switch to be triggered frequently and affecting its service life. Summary of the Invention

[0004] To address the technical problem of frequent triggering of automatic phase-switching switches in existing technologies, the present invention aims to provide a distribution network balancing dispatching method and system that considers the three-phase balance of nodes. The specific technical solution adopted is as follows:

[0005] In a first aspect, the present invention provides a distribution network balanced scheduling method considering the three-phase balance of nodes, comprising the following steps:

[0006] (1) Iteratively optimize the phase sequence configuration scheme of the current transformer area in the distribution network to obtain the optimal phase sequence configuration scheme with the minimum comprehensive operating cost score of the current transformer area;

[0007] For any phase sequence configuration scheme obtained in an iteration, the method for calculating the comprehensive operating cost score of the phase sequence configuration scheme includes:

[0008] Based on this phase sequence configuration scheme, the phase line to which each node in the current transformer area belongs is determined, and the power change of each phase is calculated in combination with the power change of each node.

[0009] Based on the power variation of each phase, the waveform transformation intervals of each phase are determined, the fluctuation penalty characteristic index of each waveform transformation interval is calculated, and the fluctuation penalty characteristic indexes of all waveform transformation intervals of all phases are summed to obtain the comprehensive operating cost score of the phase sequence configuration scheme.

[0010] (2) According to the optimal phase sequence configuration scheme, control the nodes in the current transformer area whose phase line affiliation changes to switch their respective phase lines.

[0011] In conjunction with the first aspect mentioned above, among some possible implementations, methods for calculating the fluctuation penalty characteristic index for each waveform transformation interval include:

[0012] Based on the degree of three-phase imbalance in each waveform transformation interval and the threshold of the degree of three-phase imbalance of the current transformer substation, the three-phase imbalance margin in each waveform transformation interval is calculated. The fluctuation penalty characteristic index of each waveform transformation interval is obtained by integrating the three-phase imbalance margin and the power fluctuation degree in each waveform transformation interval.

[0013] In conjunction with the first aspect mentioned above, in some possible implementation methods, the calculation method for the three-phase imbalance threshold of the current transformer substation is as follows:

[0014] The base power of the transformers in the current transformer area is obtained by multiplying the rated total capacity of the transformers in the current transformer area by the power factor of the current transformer area.

[0015] The threshold for the three-phase imbalance of the transformer in the current distribution area is obtained by multiplying the base power of the transformer in the current distribution area by the allowable ratio of three-phase imbalance.

[0016] In conjunction with the first aspect mentioned above, among some possible implementations, methods for calculating the degree of three-phase imbalance in each waveform transformation interval include:

[0017] Calculate the maximum value of the three-phase power range in each waveform transformation interval to obtain the degree of three-phase imbalance in each waveform transformation interval.

[0018] In conjunction with the first aspect mentioned above, among some possible implementations, methods for calculating the three-phase imbalance margin in each waveform transformation interval include:

[0019] For any waveform transformation interval of any phase, determine the time interval of the maximum value of the three-phase power range of the waveform transformation interval, determine the phase power of the time interval, and then determine whether the phase power of the time interval is consistent with the power polarity of the waveform transformation interval. If they are inconsistent, the three-phase imbalance degree of the waveform transformation interval is attenuated, and the difference of the attenuated three-phase imbalance degree is subtracted from the three-phase imbalance degree threshold of the current transformer substation to obtain the three-phase imbalance margin of the waveform transformation interval.

[0020] In conjunction with the first aspect mentioned above, among some possible implementations, methods for determining the waveform transformation intervals of each phase include:

[0021] The power change of each phase in a single cycle is spliced ​​together to obtain the power change of each phase in multiple cycles, and then the waveform transformation intervals of each phase are determined.

[0022] In conjunction with the first aspect mentioned above, in some possible implementations, the power variation of each node is the power variation of each node in a single cycle, and the methods for determining this include:

[0023] Based on the historical power data of each node for each period, a historical power sequence for each node for each period is constructed. Based on the statistical characteristics of the power at the same time interval in the historical power sequence of each node for each period, the power change of each node in a single period is obtained.

[0024] In conjunction with the first aspect mentioned above, among some possible implementation methods, the method of controlling the switching of the phase line belonging to nodes in the current transformer area when the phase line assignment changes according to the optimal phase sequence configuration scheme includes:

[0025] Based on the power changes of each phase, the change in the total load intensity of the current transformer area is determined, and then the safe time period with the minimum total load intensity of the current transformer area is determined. When the safe time period is reached, the nodes in the current transformer area whose phase line assignments have changed are controlled to switch their assigned phase lines according to the optimal phase sequence configuration scheme.

[0026] In conjunction with the first aspect mentioned above, among some possible implementation methods, the termination conditions for iterative optimization include: reaching the maximum number of iterations or the minimum value of the comprehensive operating cost score remaining unchanged after a set number of consecutive iterations.

[0027] Secondly, the present invention also provides a distribution network balancing dispatching system that considers the three-phase balance of nodes, including a distribution network balancing dispatching module and a distribution network transformer area power consumption information acquisition module. The distribution network transformer area power consumption information acquisition module is used to acquire the power change status of each node in each transformer area in the distribution network and send it to the distribution network balancing dispatching module.

[0028] The distribution network balancing scheduling module includes a processor, which is used to perform balancing scheduling on each distribution area based on the power changes of each node in each distribution area when executing a computer program. The balancing scheduling method for any distribution area in the distribution network adopts the distribution network balancing scheduling method of the present invention that considers the three-phase balance of the nodes.

[0029] The present invention has the following beneficial effects: For any phase sequence configuration scheme, the present invention determines the phase line to which each node in the current transformer area belongs based on the phase sequence configuration scheme, and calculates the power change of each phase by combining the power change of each node, thereby determining the waveform transformation interval of each phase. By determining the waveform transformation interval, the long-cycle data of each power polarity reversal is extracted, and the fluctuation penalty characteristic index is calculated based on the long-cycle historical data to evaluate the long-cycle fluctuation. It is no longer limited to the load fluctuation of a single instant, but performs equalization configuration on a longer time scale, avoiding the problem of frequent switching of configuration schemes and affecting automatic phase switching caused by equalization configuration based on instantaneous data in the prior art. Attached Figure Description

[0030] Figure 1 This is a structural diagram of a distribution network balancing and scheduling system considering the three-phase balance of nodes, according to an embodiment of the present invention.

[0031] Figure 2 This is a flowchart of a distribution network balancing scheduling method considering the three-phase balance of nodes, according to an embodiment of the present invention. Detailed Implementation

[0032] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0033] The structure of the distribution network balancing dispatch system considering the three-phase balance of nodes in this invention is as follows: Figure 1 As shown, it includes a distribution network balancing and dispatching module and a distribution network transformer area power consumption information acquisition module. The distribution network transformer area power consumption information acquisition module is used to acquire historical power data of each node in each transformer area of ​​the distribution network, equipment models of each node in each transformer area, topology of each transformer area, and transformer capacity data of each transformer area, and send them to the distribution network balancing and dispatching module.

[0034] The distribution network balancing scheduling module includes a processor. When executing a computer program, the processor performs balancing scheduling on each distribution area based on the power changes of each node in each distribution area. The method for balancing scheduling any distribution area adopts the distribution network balancing scheduling method of the present invention that considers the three-phase balance of the nodes.

[0035] This embodiment uses the current transformer area as an example for explanation. The specific process of the distribution network balancing scheduling method considering the three-phase balance of nodes in this invention is as follows: Figure 2 As shown, it includes the following steps:

[0036] Step 1: Determine the type of each node in the current distribution area based on the equipment model of each node; determine the power change of each node based on the historical power data of each node in the current distribution area.

[0037] (1.1) Determine the type of each node in the current distribution area based on the equipment model of each node in the current distribution area.

[0038] In this embodiment, the method for determining the type of each node includes: based on the equipment model of each node in the current distribution area, determining whether each node is equipped with an automatic phase-change switch that can be remotely controlled; identifying nodes with automatic phase-change switches as adjustable nodes; and identifying nodes without automatic phase-change switches and whose physical wiring is fixed and cannot be remotely switched as fixed-attachment nodes.

[0039] (1.2) Based on the current transformer capacity data of the current distribution area, determine the three-phase unbalanced power threshold (also known as the three-phase unbalance degree threshold) of the current distribution area transformer.

[0040] Based on the current rated total capacity of transformers in the distribution area and the preset allowable ratio of three-phase imbalance The three-phase unbalanced power threshold of the transformer is calculated. Specific calculation methods include:

[0041]

[0042] In the formula, This is the transformer unbalanced power threshold. This represents the total rated capacity of the transformers in the current distribution area. The current power factor of the transformer area. This is the reference power of the transformer. The preset allowable three-phase imbalance ratio, based on power industry standards, is typically 0.15 or 0.20. In this embodiment, 0.20 is used, meaning the three-phase power range cannot exceed 20% of the transformer's base power. Currently, the power factor range for the front-end area is [0.85, 0.95]. In this embodiment, =0.9.

[0043] (1.3) Based on the historical power data of each node in the current transformer area, determine the power change of each node in a single cycle.

[0044] Since the historical power data for a single cycle of each node is relatively small and prone to extreme outliers, this embodiment addresses this issue by utilizing historical power data for a predetermined number of cycles for each node to determine the power variation for a single cycle. Therefore, in this embodiment, the historical power data for each node includes historical power data for a predetermined number of cycles. As the optimal implementation, the historical power data for the predetermined number of cycles is the historical power data for the cycle most recent to the current time.

[0045] Since users' electricity consumption habits may be the same at the same time on different natural days, the power of each node will change periodically with natural days as the cycle. Therefore, in this embodiment, one natural day is taken as one cycle.

[0046] In this embodiment, the power variation of each node in a single period is quantitatively evaluated using the daily reference power sequence of each node. The specific method for constructing the daily reference power sequence of each node includes:

[0047] Based on the historical power data of each node for each natural day, a historical power sequence for each node for each natural day is constructed.

[0048] Based on the historical power sequences of each node for each natural day, a daily baseline power sequence for each node is constructed.

[0049] With the first Taking the nth node as an example, construct the nth node. The method for obtaining the historical power sequence of each natural day for each node includes: for the node ( The value range of is [1, D], where D is a set number of natural days. These natural days are divided into K time intervals according to a set interval, based on the ... The node of the first Historical power data for the first natural day, calculate the [number]th [day]. The node of the first The first day of the calendar Historical power over a time interval And thus obtain the first The node of the first Historical power sequence of 1 natural day .in Indicates the first 1 node Indicates the first One natural day. Indicates the first A time interval.

[0050] In this embodiment, the number is set to 30, D=30, the interval is set to 15 minutes, and a natural day is divided into 96 time intervals, K=96.

[0051] In this embodiment, the method for calculating the historical power of each time interval includes calculating the first... The node of the first The first day of the calendar day The average of the historical power over the nth time interval is used to obtain the nth The node of the first The first day of the calendar day Historical power over a time interval .

[0052] With the first Taking a node as an example, the method for constructing the daily reference power sequence for that node includes: based on the first node... The historical power sequence of each natural day for each node is used to calculate the power of the node. The node of the first The reference power of the first time interval is obtained, and then the first time interval is obtained. The daily baseline power sequence of the nth node. Where the calculation of the nth node... The node of the first Methods for determining the reference power over a time interval include:

[0053] Based on the The historical power sequence of each natural day of the node is extracted. The first day of each natural day of each node The historical power of the nth time interval is obtained. The node of the first The historical power sequence of the nth time interval is used to determine its statistical characteristics (in this embodiment, the median; in other embodiments, it can also be the mean, root mean square, or other statistical characteristics) to obtain the nth time interval. The node of the first The reference power for each time interval.

[0054] Step 2: Based on the current transformer area topology, iteratively optimize the phase sequence configuration scheme of the current transformer area to obtain the optimal phase sequence configuration scheme of the current transformer area.

[0055] A phase sequence configuration scheme includes the phase lines to which each node in the current transformer area belongs. During the iterative optimization process, the phase lines to which adjustable nodes belong can be adjusted and changed, while the phase lines to which fixed nodes belong are fixed and cannot be adjusted or changed.

[0056] The phase line to which the fixed docking node belongs is obtained based on the current transformer area topology.

[0057] In this embodiment, a genetic algorithm is used to iteratively optimize the phase sequence configuration scheme of the current transformer area, with the optimization objective being to minimize the overall operating cost score. In this embodiment, the iteration termination condition is: reaching the preset maximum number of iterations or the minimum overall operating cost score remaining unchanged for a set number of consecutive iterations. The maximum number of iterations is less than the theoretical number of phase sequence configuration schemes for the current transformer area, and in this embodiment, it is set to 1000 iterations. The set number of iterations is 50; if the minimum overall operating cost score remains unchanged for 50 consecutive iterations, the iteration terminates.

[0058] For any given phase sequence configuration scheme, the methods for calculating its comprehensive operating cost score include:

[0059] (2.1) Based on the phase sequence configuration scheme, determine the phase line to which each node belongs, sum the reference power of all nodes belonging to the same phase line in the same time interval, and obtain the daily power sequence of the three phases ABC of the phase sequence configuration scheme (characterizing the power change of each phase and the power change of each phase in a single cycle), and then calculate the power range of different phases in the same time interval to obtain the power range sequence.

[0060] For any given time interval, sum the reference power of all nodes in phase A within that time interval to obtain the power for that time interval. Repeat this step to obtain the daily power sequence of phase A. .

[0061] For any given time interval, sum the reference power of all nodes in phase B for that time interval to obtain the power for that time interval. Repeat this step to obtain the daily power sequence of phase B. .

[0062] For any given time interval, sum the reference power of all nodes in phase C for that time interval to obtain the power for that time interval. Repeat this step to obtain the daily power sequence of phase C. .

[0063] For any given time interval, determine the maximum and minimum power values ​​among the three phases A, B, and C, and calculate the absolute value of the difference between them to obtain the power range for that time interval. This leads to the power range sequence. .

[0064] (2.2) Based on the daily power sequence of the three phases ABC according to the phase sequence configuration scheme, the first and last phases are repeatedly spliced ​​to obtain the multi-day power sequence of the three phases ABC, and then the waveform transformation intervals of the three phases ABC are determined, and the peak-valley difference of each waveform transformation interval is calculated.

[0065] Because long-period power fluctuations can span multiple calendar days (e.g., high load starting in the evening of the previous day and continuing until the early morning of the next day), directly using single-day data would truncate the complete fluctuation, leading to inaccurate identification. To address this issue, this embodiment performs a first-to-last repetition splicing of the daily power sequence of the ABC three-phase configuration scheme, ensuring continuous fluctuations in the middle portion of the spliced ​​sequence. Specific methods include:

[0066] The daily power sequence of the three A phases By splicing the first and last parts together, we obtain the multi-day (multi-period) power sequence of phase A. The daily power sequence of phase A Repeat three times. Similarly, use the daily power sequences of the three B phases. By splicing the first and last phases together, the multi-day power sequence of phase B is obtained. The daily power sequence of the three C phases By splicing the first and last phases together, the multi-day power sequence of phase C is obtained. In this embodiment, the multi-day power sequence of the ABC three phases... , and Each data point consists of 96*3=288 time intervals.

[0067] In this embodiment, the method for determining the waveform transformation intervals of the three phases A, B, and C uses the rainflow counting algorithm. For a multi-day power sequence of any single phase, the specific steps include:

[0068] To eliminate false peaks and valleys caused by noise in the multi-day power sequence, this embodiment first performs hysteresis filtering on the multi-day power sequence of the phase to filter out data with power below a set power threshold. Then, local peak points and local valley points are determined, followed by the determination of waveform transformation bands, and the start time interval of each band is recorded. and end time interval Forming waveform transformation interval ,in For the first Each waveform transformation interval The first of the multi-day power series The data point, that is, the first data point. A time interval, The value range is [1, 288]. The peak and valley values ​​of each waveform transformation interval are determined, and then the peak-valley difference of each waveform transformation interval is calculated. This characterizes the degree of power fluctuation in each waveform transformation interval.

[0069] In this embodiment, the power threshold is set to 3% to 5% of the transformer's base power. This threshold level covers the typical short-term power fluctuation amplitude caused by the random start-stop superposition of a few single-phase household appliances (such as several air conditioners, electric water heaters, etc.) in the distribution substation area. By filtering out the underlying disturbances below this threshold, it is possible to prevent high-frequency small-amplitude spikes from being misjudged as independent alternating cycles by the algorithm, ensuring that what is retained are the long-period macroscopic peaks and troughs caused by photovoltaic daytime backfeeding and concentrated nighttime loads.

[0070] The peak-to-valley difference of each waveform transformation interval was calculated. The specific calculation methods include:

[0071]

[0072] In the formula, For the first The power of the starting time interval of each waveform transformation interval For the first The power at the end time interval of each waveform transformation interval It represents the absolute value.

[0073] The above steps extract long-cycle data of each power polarity (power direction) reversal by determining the waveform transformation interval. This facilitates subsequent evaluation of each long-cycle power polarity reversal, enabling rating of long-cycle macro load fluctuations, rather than being limited to instantaneous load fluctuations at a single moment.

[0074] (2.3) Calculate the degree of three-phase imbalance in each waveform transformation interval of the three phases ABC; calculate the comprehensive operating cost score of the phase sequence configuration scheme based on the degree of three-phase imbalance in each waveform transformation interval of the three phases ABC and the peak-valley difference in each waveform transformation interval of the three phases ABC.

[0075] Specific methods include:

[0076] Based on the start and end time intervals of each waveform transformation interval of the three phases ABC, the corresponding sequence segment is determined in the power range sequence, and then the maximum range value of the corresponding sequence segment is determined to measure the degree of three-phase imbalance in each waveform transformation interval.

[0077] Based on the maximum range of the corresponding sequence segment and the peak-to-valley difference of the waveform transformation interval, the fluctuation penalty characteristic index of the waveform transformation interval is obtained. The fluctuation penalty characteristic indices of all waveform transformation intervals of phases A, B, and C are summed to obtain the operating cost score of phases A, B, and C. The operating cost scores of each phase are then summed to obtain the comprehensive operating cost score of the phase sequence configuration scheme.

[0078] In this embodiment, since the waveform transformation interval is a multi-day power sequence including data from multiple natural days, while the power range sequence only contains data from a single natural day, the number of time intervals between the two is not equal, making a one-to-one correspondence impossible. Therefore, it is necessary to replace the start and end time intervals of each waveform transformation interval with data from a single natural day, and then determine the corresponding sequence segment from the range of the power range sequence. Specific methods include:

[0079] First, determine Is it greater than or equal to the total number of time intervals per day? ,like Then the entire power range sequence is directly taken as the corresponding sequence segment. The corresponding sequence segment is determined using the following method:

[0080]

[0081]

[0082] In the formula, For the first The waveform transformation interval corresponds to the start time interval of the corresponding sequence segment in the power range sequence. For the first The time interval between the end of the corresponding sequence segment of the power range sequence for each waveform transformation interval; Indicates the independent variable Divide by The remainder. If Then, the sequence segment between the start and end time intervals of the power range sequence is directly [ ,…, ] can be used as the corresponding sequence segment, if Then the starting time interval will be... and maximum time interval (In this embodiment) Sequence segments between =96) and from the smallest time interval ( ) and end time interval By splicing the sequence segments from one another, a sequence segment is obtained. ,…, , ,…, ],in For the first The power range of the starting time interval of the corresponding sequence segments in each waveform transformation interval. The power range is the power range of the last time interval in the power range sequence. The power range is the power range of the first time interval in the power range sequence. For the first The power range of the end time interval of the corresponding sequence segments in each waveform transformation interval.

[0083] To address the issue that the waveform transformation interval is a multi-day power sequence containing data from multiple natural days, while the power range sequence only contains data from a single natural day, resulting in unequal time intervals and the inability to correspond one-to-one, in other implementations, the power range sequence can also be repeatedly spliced ​​together to obtain a multi-day power range sequence, thus ensuring that the number of time intervals between the two sequences is equal.

[0084] For any waveform transformation interval of any phase, the methods for calculating the fluctuation penalty characteristic index of that waveform transformation interval include:

[0085] The maximum range of the corresponding sequence segment in the power range sequence for the waveform transformation interval. The polarity of the time interval is verified to determine whether the power polarity of this time interval is consistent with the power polarity of the entire waveform transformation range. If they are inconsistent, for example, if the entire waveform transformation range is dominated by reverse power supply to the distribution network (negative power), but the power polarity of the time interval corresponding to the maximum range is positive (caused by short-term spikes), it indicates that the three-phase imbalance in this time interval is an isolated disturbance unrelated to the main fluctuation. A polarity consistency attenuation coefficient is set to a preset minimum value to attenuate the maximum range, thereby reducing the interference of short-term spikes on the evaluation results. If they are consistent, it indicates that the three-phase imbalance in this time interval is related to the main fluctuation, and the polarity consistency attenuation coefficient is set to 1 (i.e., no attenuation). The polarity consistency attenuation coefficient and the maximum range are then compared. Multiplying them yields the updated maximum range. The preset minimum value range is [0.1, 0.2], and in this embodiment, it is 0.1.

[0086] Based on the updated maximum range Subtract the current three-phase unbalanced power threshold of the transformer in the distribution area. The three-phase imbalance margin is obtained. The three-phase imbalance margin and the waveform transformation range are integrated. The fluctuation penalty characteristic index of the waveform transformation range is obtained. The calculation formula is as follows:

[0087]

[0088] In the formula, To calculate the maximum value, the fluctuation penalty characteristic index is used when the maximum value of the range after decay does not exceed the limit. Set to 0. The larger the three-phase imbalance margin and the larger the peak-to-valley difference in the waveform transformation range, the larger the fluctuation penalty characteristic index.

[0089] The three-phase imbalance margin is used to assess the differences between different phases in the same transformer area at the same time, and belongs to the evaluation factor of the same time but different space. The peak-valley difference of the waveform transformation interval is the fluctuation of the same phase line at different times, and belongs to the evaluation factor of the same space but different times. In this embodiment, these two evaluation factors are integrated to form a spatiotemporal comprehensive evaluation factor. The fluctuation situation of the current transformer area is evaluated from two dimensions.

[0090] In this embodiment, the method for determining the power polarity of the waveform transformation interval includes: calculating the power mean within the entire waveform transformation interval, determining the polarity of the power mean (positive or negative; in this embodiment, load power consumption is positive, and power supply to the distribution network is negative), and using this as the power polarity of the entire waveform transformation interval; the method for determining the power polarity of the time interval of the maximum range includes: determining the maximum range of the corresponding sequence segment. The time interval is determined, and the power of that time interval is determined in the daily power sequence of that phase, thereby determining the polarity of the power of that time interval.

[0091] Step 3: Based on the optimal phase sequence configuration scheme determined through iteration, control the switching of the phase line to which each node whose phase line affiliation changes.

[0092] (3.1) Compare the optimal phase sequence configuration scheme with the current actual phase sequence configuration scheme of the current transformer area, filter out the nodes whose phase line ownership has changed, generate the corresponding node's phase switching control message according to the power line carrier communication protocol format, which includes the original phase line and target phase line information, and store it in the transmission buffer to wait for it to be sent.

[0093] (3.2) Based on the daily power sequence of the three phases ABC, calculate the daily total load intensity sequence of the current transformer area, determine the time interval with the minimum total load intensity, and map this time interval to the actual time period to obtain the safe time period.

[0094] Specific methods for calculating the daily total load intensity sequence of the current transformer area include:

[0095] For any given time interval, sum the absolute values ​​of the power of phases A, B, and C during that time interval to obtain the total load intensity for that time interval.

[0096] Repeat the above steps for each time interval to obtain the daily total load intensity sequence for the current transformer area.

[0097] (3.3) When the actual time reaches the safe period, the phase switching control message in the buffer is uniformly sent to each automatic phase switching switch through the power line carrier channel; the switch completes the phase line switching under low load conditions, and finally realizes the global static balance adjustment of the three-phase load of the current transformer area.

[0098] In summary, this invention abandons the traditional high-frequency real-time response mechanism for transient ranges in distribution network monitoring systems. Instead, it constructs a long-period phase sequence configuration method that considers both the time-domain band span and the spatial three-phase range, using a combined weighted average. This method incorporates long-period amplitude into the evaluation, suppressing thermal fatigue damage caused by large-scale alternating switching of transformers throughout the day, and achieving a global, one-time static equilibrium deployment. Furthermore, this invention filters short-term spike interference to avoid frequent operation of commutation switches due to transient ranges, thus reducing mechanical lifespan losses. By performing switching during the period of lowest absolute power throughout the day, it avoids the risk of arc burnout caused by high-current disconnection, ensuring equipment safety.

Claims

1. A distribution network balanced scheduling method considering the three-phase balance of nodes, characterized in that, Includes the following steps: (1) Iteratively optimize the phase sequence configuration scheme of the current transformer area in the distribution network to obtain the optimal phase sequence configuration scheme with the minimum comprehensive operating cost score of the current transformer area; For any phase sequence configuration scheme obtained in an iteration, the method for calculating the comprehensive operating cost score of the phase sequence configuration scheme includes: Based on this phase sequence configuration scheme, the phase line to which each node in the current transformer area belongs is determined, and the power change of each phase is calculated in combination with the power change of each node. Based on the power variation of each phase, the waveform transformation intervals of each phase are determined, the fluctuation penalty characteristic index of each waveform transformation interval is calculated, and the fluctuation penalty characteristic indexes of all waveform transformation intervals of all phases are summed to obtain the comprehensive operating cost score of the phase sequence configuration scheme. (2) According to the optimal phase sequence configuration scheme, control the nodes in the current transformer area whose phase line affiliation changes to switch their respective phase lines.

2. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 1, characterized in that, Methods for calculating the fluctuation penalty characteristic index for each waveform transformation interval include: Based on the degree of three-phase imbalance in each waveform transformation interval and the threshold of the degree of three-phase imbalance of the current transformer substation, the three-phase imbalance margin in each waveform transformation interval is calculated. The fluctuation penalty characteristic index of each waveform transformation interval is obtained by integrating the three-phase imbalance margin and the power fluctuation degree in each waveform transformation interval.

3. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 2, characterized in that, The current method for calculating the three-phase imbalance threshold of the transformer in the front area is as follows: The base power of the transformers in the current transformer area is obtained by multiplying the rated total capacity of the transformers in the current transformer area by the power factor of the current transformer area. The threshold for the three-phase imbalance of the transformer in the current distribution area is obtained by multiplying the base power of the transformer in the current distribution area by the allowable ratio of three-phase imbalance.

4. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 2, characterized in that, Methods for calculating the degree of three-phase imbalance in each waveform transformation interval include: Calculate the maximum value of the three-phase power range in each waveform transformation interval to obtain the degree of three-phase imbalance in each waveform transformation interval.

5. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 4, characterized in that, Methods for calculating the three-phase unbalance margin in each waveform transformation interval include: For any waveform transformation interval of any phase, determine the time interval of the maximum value of the three-phase power range of the waveform transformation interval, determine the phase power of the time interval, and then determine whether the phase power of the time interval is consistent with the power polarity of the waveform transformation interval. If they are inconsistent, the three-phase imbalance degree of the waveform transformation interval is attenuated, and the difference of the attenuated three-phase imbalance degree is subtracted from the three-phase imbalance degree threshold of the current transformer substation to obtain the three-phase imbalance margin of the waveform transformation interval.

6. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 1, characterized in that, Methods for determining the waveform transformation intervals of each phase include: The power change of each phase in a single cycle is spliced ​​together to obtain the power change of each phase in multiple cycles, and then the waveform transformation intervals of each phase are determined.

7. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 1, characterized in that, The power variation of each node refers to the power variation of each node in a single cycle, and the methods for determining this include: Based on the historical power data of each node for each period, a historical power sequence for each node for each period is constructed. Based on the statistical characteristics of the power at the same time interval in the historical power sequence of each node for each period, the power change of each node in a single period is obtained.

8. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 1, characterized in that, The methods for controlling the switching of the phase line of nodes whose phase line affiliation changes in the current transformer area according to the optimal phase sequence configuration scheme include: Based on the power changes of each phase, the change in the total load intensity of the current transformer area is determined, and then the safe time period with the minimum total load intensity of the current transformer area is determined. When the safe time period is reached, the nodes in the current transformer area whose phase line assignments have changed are controlled to switch their assigned phase lines according to the optimal phase sequence configuration scheme.

9. The distribution network balanced scheduling method considering the three-phase balance of nodes according to claim 1, characterized in that, Termination conditions for iterative optimization include: reaching the maximum number of iterations or the minimum value of the comprehensive operating cost score remaining unchanged after a set number of consecutive iterations.

10. A distribution network balanced dispatching system considering the three-phase balance of nodes, characterized in that, It includes a distribution network balancing dispatch module and a distribution network transformer area power consumption information acquisition module. The distribution network transformer area power consumption information acquisition module is used to obtain the power change information of each node in each transformer area in the distribution network and send it to the distribution network balancing dispatch module. The distribution network balancing scheduling module includes a processor, which is used to perform balancing scheduling on each distribution area based on the power change of each node in each distribution area when executing a computer program, and the balancing scheduling method for any distribution area in the distribution network is as described in any one of claims 1-9.

Images