Power distribution system control device, power distribution system control method

Abstract

To provide a power distribution system control device and a power distribution system control method which allow system configuration in which self accommodation is easy to be selected by using tolerance according to a constraint condition such as a facility capacity as an objective function.SOLUTION: A power distribution system derivation unit 11 of a power distribution system control device 10 derives a connection relation in a power distribution system. An opening / closing signal output unit 15 generates and outputs an opening / closing signal of opening / closing each of a plurality of switches in the power distribution system on the basis of the connection relation derived by the power distribution system derivation unit 11. The power distribution system derivation unit 11 comprises: a power distribution system candidate extraction part 111 which extracts a candidate that satisfies a constraint condition by breaking a loop after turning the opening / closing state of all the switches in the power distribution system into the close state; and a power distribution system selection part 112 which selects the connection relation in the power distribution system with the extracted candidate of the power distribution system candidate extraction part 111 as a target according to the objective function calculated from a single or a plurality of evaluation values. The evaluation value is set on the basis of tolerance of the voltage or current in each facility of the power distribution system.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for optimizing the distribution system configuration of power companies and the like.

Background Art

[0002] A technique for improving the transmission efficiency from a power supply source to a consumer by controlling the opening and closing states of a group of switches arranged between the power supply source and the consumer in a distribution system is widely known.

[0003] That is, the number of combinations of the opening and closing states of N switches increases exponentially as 2 , , ,

[0007] , , ,

[0005] , , , , , , , , , , ,

[0006] ways, and the number of combinations of the opening and closing states becomes enormous.

[0004] In the optimization of the distribution system configuration, an objective function is created from evaluation values such as voltage drop and loss, and the opening and closing states of the switches are determined so as to minimize or maximize the objective function while satisfying the system constraints. As an example of this optimization technique, the distribution system control device of Patent Document 1 has been proposed, which aims to optimize various objective functions such as voltage and current.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The distribution system control device of Patent Document 1 aims to "minimize the loss in the distribution system, minimize the voltage drop amount, minimize the passing current, optimize by specifying a predetermined period, optimize considering the power flow change by a distributed power source, or optimize for improving the imbalance by an imbalance calculation", and uses the values of current, voltage, and loss as the objective function.

[0007] Indeed, in normal operation of a power distribution system, as considered in the constraints of Patent Document 1, the open / closed state of switches is determined to satisfy the allowable current and voltage of power distribution equipment such as power lines and switches. However, if the margin (safety margin) of the current or voltage from the allowable value is small, it will not be possible to transfer power to healthy sections in the event of an accident, resulting in a large section and duration of power outage.

[0008] This invention was made to solve these conventional problems, and its objective is to propose a technology that allows for the selection of a power distribution system configuration that facilitates accident reconciliation by considering a margin according to constraints such as equipment capacity. [Means for solving the problem]

[0009] (1) One aspect of the present invention is a device for controlling a power distribution system, A power distribution system derivation unit for deriving the connection relationships within the aforementioned power distribution system, Based on the connection relationships derived by the power distribution system derivation unit, the power distribution signal output unit generates and outputs a switching signal to open and close each of the multiple switches in the power distribution system, Equipped with, The aforementioned power distribution system output section is, A power distribution system candidate extraction unit extracts candidates that satisfy the constraints by breaking the loop after closing the open / closed state of all switches in the aforementioned power distribution system, A distribution system selection unit selects connection relationships within the distribution system from the candidates extracted by the distribution system candidate extraction unit, according to an objective function calculated from one or more evaluation values. Equipped with, The aforementioned evaluation value is characterized by being set based on the voltage or current margin in each piece of equipment in the power distribution system.

[0010] (2) Another aspect of the present invention is a method for controlling a power distribution system that is the target of control, A distribution system derivation step for deriving the connection relationships within the aforementioned distribution system, Based on the connection relationships derived in the power distribution system derivation step, a switching signal output step generates and outputs switching signals to open and close each of the multiple switches in the power distribution system, It has, The aforementioned power distribution system derivation step is, A distribution system candidate extraction step involves closing the open / closed state of all switches in the aforementioned distribution system and then breaking the loop to extract candidates that satisfy the constraint conditions, A distribution system selection step in which, with respect to the candidates extracted in the distribution system candidate extraction step, a connection relationship within the distribution system is selected according to an objective function calculated from one or more evaluation values, It has, The aforementioned evaluation value is characterized by being set based on the voltage or current margin in each piece of equipment in the power distribution system. [Effects of the Invention]

[0011] According to the present invention, by considering a margin corresponding to constraints such as equipment capacity, it becomes possible to select a power distribution system configuration that facilitates accident resupply. [Brief explanation of the drawing]

[0012] [Figure 1] A block diagram showing an example configuration of a power distribution system control device according to an embodiment of the present invention. [Figure 2] Configuration diagram of the same power distribution system example. [Figure 3] Figure 2 shows an example of a feeder configuration. [Modes for carrying out the invention]

[0013] The following describes a power distribution system control device according to an embodiment of the present invention. This power distribution system control device is composed of a computer and is used to optimize the power distribution system configuration of a power company or the like, as described above.

[0014] <<Example Configuration>> (1) Based on FIG. 1, the power distribution system control device 10 will be described. Here, the power distribution system control device 10 is configured substantially the same as that in Patent Document 1, and includes a power distribution system derivation unit 11, a power demand data storage unit 12, a power distribution system configuration data storage unit 13, a power generation output data storage unit 14, and an opening / closing signal output unit 15, and controls the opening / closing states of switches in the power distribution system that is the control target.

[0015] The power distribution system derivation unit 11 is realized by a processor (such as an MPU or a CPU), and includes a power distribution system candidate extraction unit 111 and a power distribution system selection unit 112. The power distribution system candidate extraction unit 111 extracts candidates that satisfy the constraint conditions from combinations of the opening / closing states of switches in the power distribution system.

[0016] The power distribution system selection unit 112 selects a connection relationship according to the objective function for the candidates extracted by the power distribution system candidate extraction unit 111. However, the power distribution system selection unit 112 in the present embodiment can select a connection relationship not only according to the connection relationship that suppresses the objective function (evaluation function) in Patent Document 1, but also according to the objective function calculated from the evaluation value regarding the margin of voltage or current, which is different from Patent Document 1 in this regard.

[0017] Each of the storage units 12 to 14 is realized by a storage medium (such as a semiconductor memory or a magnetic disk). The storage unit 12 stores power demand data in the power distribution system. The storage unit 13 stores data on the connection configuration of demand points and supply points in the power distribution system. The data on this connection configuration includes the opening / closing information of each of a plurality of switches included in the power distribution system.

[0018] The storage unit 14 stores power generation output data in the power distribution system. The opening / closing signal output unit 15 is realized by a processor and an external interface, and generates and outputs an opening / closing signal for opening / closing each of a plurality of switches in the power distribution system based on the connection relationship derived by the power distribution system derivation unit 11.

[0019] (2) An example of the configuration of the power distribution system to be controlled will be explained based on Figure 2. Here, the same example of the power distribution system configuration as in Patent Document 1 is shown, where 21a, 21b, and 21c indicate the power supply points, and the dotted (dashed) lines 23a, 23b, 23d, 23e, and 23f indicate the parts (sections) that can be controlled by switches.

[0020] At this time, the distribution system candidate extraction unit 111 enumerates and extracts candidate distribution systems based on the combination of the open / closed states of 23a, 23b, 23d, 23e, and 23f. The demand points of the distribution system are indicated as (2) to (20).

[0021] ≪About the objective function≫ The power distribution system selection unit 112 selects the power distribution system candidates extracted and enumerated by the power distribution system candidate extraction unit 111 as the target of selection. It can obtain not only the objective function of Patent Document 1 but also an evaluation value indicating the margin, and selects a power distribution system candidate based on the obtained evaluation value.

[0022] (1) To explain in detail, first, the calculation period is set using power demand data and power output data as input data, and the state in which the power supplied from the distribution system flows to each consumer through transmission lines and transformers is determined by various power flow calculations, thereby obtaining not only the objective function of Patent Document 1, but also the following evaluation values ​​for 23a, 23b, 23d, 23e, and 23f which are switched on and off by switches.

[0023] • Current usage rate: Current / Allowable current • Current tolerance: Allowable current - current • Current margin: Current margin of adjacent feeders / Total demand within the feeders • Voltage usage rate: Voltage / Rated voltage • Voltage tolerance: Allowable voltage - Voltage • Voltage tolerance: Voltage tolerance / (Total demand (current) within the feeder × Impedance) The current margin and voltage margin will be explained based on Figure 3. Figure 3 shows the case where 23e and 23b are in the closed state, and the closed state of 23e and 23b is represented by solid lines. In the same figure, A to C indicate the supply range from supply points 21a, 21b, and 21c, respectively, and 23a, 23f, and 23d indicate the interlocking switches between feeders.

[0024] Here, three feeders are shown with supply points 21a, 21b, and 21c as output points. If a power outage occurs in one feeder, power needs to be supplied (shared) by the interconnection switches 23a, 23f, and 23d.

[0025] In this case, it is desirable that the amount of power that can be exchanged (saturation) be large relative to the total power demand within the feeder, and from this perspective, indicators for current saturation and voltage saturation have been established.

[0026] In other words, the current margin and voltage margin are indicators of the ease of exchange from the perspective of adjacent feeders, and are determined for each interconnection switch from the interconnection switch to the supply point using the current and voltage of the path.

[0027] For example, the interlocking switch 23a is adjacent to a feeder supplied at 21a and a feeder supplied at 21c, and its current margin and voltage margin can be determined as follows.

[0028] • Current margin for supply from 21a = Minimum current margin of 22d, 22c, and 22a / Total demand of feeders supplied at 21c The current margin for current supplied from 21c = the minimum current margin of 22e, 22b, 22f, and 22g / the total demand of the feeder supplying 21a. Voltage margin from 21a = Minimum voltage margin of demand points (5), (4), (2) / Total demand of feeders with 21c as the supply point × Impedance from the demand point with the minimum voltage margin among demand points (5), (4), (2) to the supply point Voltage tolerance from 21c = Minimum voltage tolerance of demand points (6), (7), (8), (9) / Total demand of feeders with 21a as the supply point × Impedance from the demand point with the minimum voltage tolerance among demand points (6), (7), (8), (9) to the supply point (2) Next, group the obtained evaluation values ​​as follows:

[0029] • Evaluation Value A: Current usage rate, voltage usage rate (a higher value indicates a smaller margin of error) • Evaluation Value B: Current Tolerance, Current Tolerance Ratio, Voltage Tolerance, Voltage Tolerance Ratio (A smaller value indicates a smaller tolerance) In this case, since the open / closed state of the switches differs for each candidate distribution system, the evaluation values ​​(current utilization rate, current margin, etc.) for each demand point, power line, and interconnection switch equipment in Figure 2 will be different for each.

[0030] Then, the optimal distribution system is selected from the distribution system candidate extraction unit 111 using the following criteria.

[0031] Criterion 1: Select the system (combination of open / closed states) that minimizes the maximum value of evaluation value A across multiple pieces of equipment. Criterion 2: Select the system (combination of open / closed states) that maximizes the minimum value B across multiple pieces of equipment. Criterion 3: Select the system (combination of open / closed states) that maximizes the minimum value of evaluation value A across multiple pieces of equipment. • Criterion 4: Select the system (combination of open / closed states) that minimizes the maximum value of evaluation value B across multiple pieces of equipment. • Criterion 5: Select the system (combination of open / closed states) that minimizes the average value of evaluation value A across multiple pieces of equipment. • Criterion 6: Select the system (combination of open / closed states) that maximizes the average value of evaluation value B across multiple pieces of equipment. Criterion 7: Select the system (combination of open / closed states) that minimizes the median value of evaluation A across multiple pieces of equipment. Criterion 8: Select the system (combination of open / closed states) that maximizes the median value of evaluation value B across multiple pieces of equipment. Criterion 9: Select the system (combination of open / closed states) that minimizes the variance of evaluation value A across multiple pieces of equipment. Criterion 10: Select the system (combination of open / closed states) that minimizes the variance of evaluation value B across multiple pieces of equipment. In this case, the "variance (V)" in criteria 9 and 10 can be calculated using equation (1).

[0032]

number

[0033] Furthermore, when using criteria 1 to 10, one criterion may be used, or a combination of multiple criteria may be used, and when using multiple criteria, each criterion may be weighted. However, from the viewpoint of sharing power between feeders as described above, it is preferable to use either criterion 1 or 2, or a combination of criteria 1 and 2.

[0034] By selecting the optimal distribution system using this distribution system selection unit 112, the current and voltage margins, considering constraints such as equipment capacity, are used as evaluation values, making it possible to select a distribution system configuration that facilitates fault handling.

[0035] As a result, it becomes possible to select the appropriate open / closed state of the switch in the event of an accident in the power distribution system, thereby improving the stability of the power distribution system. Furthermore, by adopting a power distribution system configuration with greater margin, it becomes possible to select a power distribution system configuration that facilitates the linkage of distributed power sources.

[0036] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented with modifications within the scope of each claim. For example, the device configuration is not limited to Figure 1, and each storage unit 12 to 13 may be constructed on the same storage medium, or it may be configured as a power distribution system control method executed by the power distribution system control device 10. [Explanation of symbols]

[0037] 10... Power distribution system control device 11...Power distribution system lead-out section 12…Power demand data storage unit 13…Distribution system configuration data storage unit 14…Power generation output data storage unit 15...Open / Close Signal Output Section 21a~21c…supply point 22a~22n…Electric wire 23a~23f…Switch 111…Distribution system candidate extraction unit 112... Power distribution system selection section

Claims

1. A device that controls the power distribution system that is the target of control, A power distribution system derivation unit for deriving the connection relationships within the aforementioned power distribution system, Based on the connection relationships derived by the power distribution system derivation unit, the power distribution signal output unit generates and outputs a switching signal to open and close each of the multiple switches in the power distribution system, Equipped with, The aforementioned power distribution system output section is, A power distribution system candidate extraction unit extracts candidates that satisfy the constraints by breaking the loop after closing the open / closed state of all switches in the aforementioned power distribution system, A distribution system selection unit selects connection relationships within the distribution system from the candidates extracted by the distribution system candidate extraction unit, according to an objective function calculated from one or more evaluation values. Equipped with, The aforementioned evaluation value is, It is set based on the voltage or current margin in each piece of equipment in the aforementioned power distribution system. The evaluation values ​​were divided into groups A and B. The aforementioned evaluation value A uses at least one of the following: current usage rate (current / allowable current) and voltage usage rate (voltage / allowable voltage), The evaluation value B includes at least one of the following: current margin (allowable current - current), current margin ratio (current margin of adjacent feeders / demand within the feeder), voltage margin (allowable voltage - voltage), and voltage margin ratio (voltage margin / demand within the feeder × impedance). The power distribution system control device according to claim 1, characterized in that it is as described above.

2. The maximum, minimum, mean, median, or variance of at least one of the evaluation values ​​A and B in the multiple aforementioned devices is The power distribution system control device according to claim 1, characterized by selecting the minimum or maximum connection state.

3. The power distribution system control device according to claim 2, characterized in that it selects the connection state using at least one of the following criteria. Criterion 1: The connection state in which the maximum value of evaluation value A across multiple pieces of equipment is minimized. Criterion 2: The connection state in which the minimum value B of evaluation value B across multiple pieces of equipment is maximized. Criterion 3: The connection state in which the minimum value of evaluation value A across multiple pieces of equipment is maximized. Criterion 4: Connection state that minimizes the maximum value of evaluation value B across multiple pieces of equipment. Criterion 5: The connection state that minimizes the average value of evaluation value A across multiple pieces of equipment. Criterion 6: The connection state that maximizes the average value of evaluation value B across multiple pieces of equipment. Criterion 7: Connection state that minimizes the median value of evaluation value A across multiple pieces of equipment. Criterion 8: The connection state that maximizes the median value of evaluation value B across multiple pieces of equipment. Criterion 9: Connection state that minimizes the variance of evaluation value A across multiple pieces of equipment. Criterion 10: Connection state that minimizes the variance of evaluation value B across multiple pieces of equipment.

4. A method for controlling a power distribution system that is the target of control, A distribution system derivation step for deriving the connection relationships within the aforementioned distribution system, Based on the connection relationships derived in the power distribution system derivation step, a switching signal output step generates and outputs switching signals to open and close each of the multiple switches in the power distribution system, It has, The aforementioned power distribution system derivation step is, A distribution system candidate extraction step involves closing the open / closed state of all switches in the aforementioned distribution system and then breaking the loop to extract candidates that satisfy the constraint conditions, A distribution system selection step in which, with respect to the candidates extracted in the distribution system candidate extraction step, a connection relationship within the distribution system is selected according to an objective function calculated from one or more evaluation values, It has, The aforementioned evaluation value is, It is set based on the voltage or current margin in each piece of equipment in the aforementioned power distribution system. The evaluation values ​​were divided into groups A and B. The aforementioned evaluation value A uses at least one of the following: current usage rate (current / allowable current) and voltage usage rate (voltage / allowable voltage), The evaluation value B includes at least one of the following: current margin (allowable current - current), current margin ratio (current margin of adjacent feeders / demand within the feeder), voltage margin (allowable voltage - voltage), and voltage margin ratio (voltage margin / demand within the feeder × impedance). A power distribution system control method characterized by the following:

Images