JP2015008575A - Selection method and selection device of power interchange pattern of distribution system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a selection method of power interchange pattern of a distribution system capable of suppressing occurrence of trouble in the operation of the distribution system, by avoiding increase of calculation processing time in the power interchange calculation by a simple system.SOLUTION: A selection method of the power interchange pattern of a distribution system interchanging the power for a predetermined section of a distribution line includes a step for extracting a plurality of power interchange patterns of a distribution system capable of interchanging power for the predetermined section via a linkage switch, a step for calculating the resistance and reactance from a system power supply to the linkage switch for the power interchange patterns thus extracted, a step for calculating the voltage of the linkage switch, respectively, in the plurality of power interchange patterns, based on the resistance and reactance thus calculated and the effective power and reactive power in the predetermined section, a step for extracting a power interchange pattern satisfying the voltage conditions in a predetermined range among the plurality of power interchange patterns, based on the calculation results, and a step for selecting a suitable power interchange pattern among the power interchange patterns thus extracted.

Description

  The present invention relates to a method and an apparatus for selecting an interchange pattern of a power distribution system when switching the power distribution system at the time of an accident or work.

  In the conventional distribution automation system, when an accident in the distribution system occurs, the power supply to the sections other than the accident section is continued, and the interchange operation to the load side section (healthy power outage section) of the accident section is performed. . In the accommodation operation, a check is performed in the accommodation calculation so that voltage deviation and overload do not occur in the system state after accommodation.

  In general, in the voltage check of the interchange calculation, the voltage is calculated using the voltage drop calculation method on the premise that the voltage drops from the outlet of the distribution line toward the end, and the voltage in the distribution system is A check is made to ensure that the voltage lower limit is not deviated.

  On the other hand, there is a concern that the voltage upper limit value may be deviated in the distribution system due to the recent connection to the distribution line of photovoltaic power generation. Therefore, in the accommodation calculation, it is necessary to check not only the voltage lower limit value but also the voltage upper limit value in the system after accommodation.

  As a method for calculating the voltage of a distribution system in which reverse power flow from a distributed power source such as photovoltaic power generation occurs, it is conceivable to use the power flow calculation used for calculating the voltage and power flow of the transmission system.

  Japanese Patent Laying-Open No. 2006-246683 discloses a method for checking whether or not accommodation is possible by calculating power flow at the time of an accident or work.

JP 2006-246683 A

  On the other hand, in order to check whether there is a deviation of the upper and lower limit values of the voltage in the system state after the interchange, the presence of deviation of the lower limit value of the voltage is checked under the condition that the voltage drop occurs, and the voltage rises. Under certain conditions, it is necessary to check whether there is a deviation from the upper voltage limit. That is, in order to check the upper and lower limit values of the voltage, the voltage calculation must be performed in the load state of the two cross sections as described above, so that the calculation processing time may be longer than before.

  In the calculation of accommodation, in order to determine the system state after the accommodation, the voltage / current distribution of the load state of the two cross sections for all combinations of the interconnection point of the distribution system that is the accommodation source and the section to be accommodated. Since it is necessary to perform calculations, there is a concern that the calculation processing time will be longer than before and that the operation of the distribution system will be hindered.

  The present invention has been made to solve the above-described problems, and it is possible to avoid an increase in calculation processing time in a flexible calculation by a simple method and to prevent the operation of the distribution system from being hindered. It is an object of the present invention to provide a method and an apparatus for selecting an interchange pattern of a simple power distribution system.

  A power distribution system in which a plurality of distribution lines connected to a system power supply according to a certain aspect are divided into a plurality of sections by a plurality of switches, and at least one interconnection switch for electrically connecting the distribution lines to each other is provided In a system, a method for selecting an interchange pattern of a distribution system for selecting an interchange pattern for accommodating power from another distribution line via a connection switch for a predetermined section of the distribution line, the connection switch A step of extracting a plurality of distribution patterns of a distribution system capable of accommodating power for a predetermined section through the calculation of the resistance and reactance from the system power source to the interconnection switch for the extracted accommodation pattern And the voltage of the interconnection switch based on the calculated resistance and reactance and the active power and reactive power in a predetermined section in a plurality of interchange patterns. Based on the calculation results, a step for extracting an accommodation pattern satisfying a voltage condition within a predetermined range from a plurality of accommodation patterns, and a suitable accommodation pattern from the extracted accommodation patterns. Selecting.

Preferably, the predetermined range corresponds to a first range narrower than a specified upper and lower limit value.
In particular, the step of extracting an accommodation pattern that satisfies a voltage condition within a predetermined range is performed when the calculated voltage is included in a second range other than the first range that is narrower than a specified upper and lower limit value. The method further includes the step of analyzing the trend and the step of extracting the accommodation pattern based on the analysis result.

  A power distribution system in which a plurality of distribution lines connected to a system power supply according to a certain aspect are divided into a plurality of sections by a plurality of switches, and at least one interconnection switch for electrically connecting the distribution lines to each other is provided An apparatus for selecting an interchange pattern of a distribution system that selects an interchange pattern for accommodating power from another distribution line via a connection switch for a predetermined section of the distribution line. A first extraction unit for extracting a plurality of accommodation patterns of a distribution system capable of accommodating power to a predetermined section via a power supply, and a system power supply to open and close the interconnection patterns extracted by the first extraction unit A first calculation unit that calculates resistance and reactance up to the vessel, and a plurality of interchange patterns, the resistance and reactance calculated by the first calculation unit, and active power and no A second calculation unit that calculates the voltage of the interconnection switch based on the electric power, and a voltage condition within a predetermined range from a plurality of accommodation patterns based on the calculation result calculated by the second calculation unit A second extraction unit that extracts the accommodation pattern and a selection unit that selects a suitable accommodation pattern from the accommodation patterns extracted by the second extraction unit.

Preferably, the predetermined range corresponds to a first range narrower than a specified upper and lower limit value.
In particular, the second extraction unit includes an analysis unit that analyzes a voltage trend when the calculated voltage is included in a second range other than the first range, which is narrower than a specified upper and lower limit value, and an analysis result And a third extraction unit for extracting the accommodation pattern based on the above.

  With a simple method, it is possible to avoid an increase in calculation processing time in the accommodation calculation, and to prevent the operation of the distribution system from being hindered.

It is a figure explaining the whole structure of the power distribution system 1 according to this Embodiment. It is a figure explaining the structure of the protection relay according to this Embodiment. It is a schematic block diagram explaining the structure of the control apparatus 10 according to this Embodiment. It is a processing flowchart which performs the selection method of the interchange pattern of the distribution system according to this Embodiment. It is a figure explaining the range which selects the accommodation pattern candidate according to this Embodiment. It is a figure explaining the specific example of the determination method of the accommodation pattern in case the 2nd area of the distribution line 4b of FIG. 1 turns into an accident area. It is a processing flowchart which performs the selection method of the accommodation pattern of the distribution system according to the modification of this Embodiment. It is a figure explaining the range which selects the accommodation pattern candidate according to the modification of this Embodiment.

  The present embodiment will be described below with reference to the drawings. In the description of the embodiments, when the number and amount are referred to, the scope of the present invention is not necessarily limited to the number and amount unless otherwise specified. In the description of the embodiments, the same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated. Unless there is a restriction | limiting in particular, it is planned from the beginning to use suitably combining the structure shown to the structure shown to embodiment.

FIG. 1 is a diagram illustrating an overall configuration of a power distribution system 1 according to the present embodiment.
Referring to FIG. 1, a distribution system 1 includes transformers 2a to 2c provided at various locations of a distribution substation, and circuit breakers 3a to 3c provided corresponding to the transformers 2a to 2c, respectively. Distribution lines 4a-4c provided corresponding to circuit breakers 3a-3c, respectively. Moreover, the some division switch 15a-15f arranged in cascade with respect to the distribution line 4a, and the protection relays 5a-5f provided corresponding to the division switch 15a-15f, respectively are provided. In this example, the case where it is divided into 7 sections as a result of having arrange | positioned switch 15a-15f with respect to the distribution line 4a is shown. Similarly, a case is shown in which the section switches 16a to 16f are arranged with respect to the distribution line 4b and are divided into seven sections. Similarly, the case where it is divided into 7 sections as a result of the arrangement switches 17a to 17f being arranged with respect to the distribution line 4c is shown.

  Moreover, the some division switch 16a-16f arrange | positioned in series with respect to the distribution line 4b, and the protection relays 6a-6f provided corresponding to the division switches 16a-16f, respectively are provided. Moreover, the some division switch 17a-17f arranged in cascade with respect to the distribution line 4c and the protection relays 7a-7f provided corresponding to the division switches 17a-17f, respectively are provided. Furthermore, a connection switch SW1 is provided between the distribution line 4a and the distribution line 4b, and a protective relay 8a is provided corresponding to the connection switch SW1. In addition, an interconnection switch SW2 is provided between the distribution line 4b and the distribution line 4c, and a protective relay 8b is provided corresponding to the interconnection switch SW2. The protective relays 5a to 5f, 6a to 6f, 7a to 7f, 8a and 8b (hereinafter also collectively referred to as protective relays 5, 6, 7 and 8) are provided so as to be able to communicate with the control device 10, respectively. In accordance with an instruction from the control device 10, the corresponding switch is provided to be able to open and close.

  Note that the transformers 2a to 2c may be connected to a single system power supply, or may be independent. In this example, although not illustrated, it is assumed that a distributed power source is also provided so as to be connected to the distribution lines 4a to 4c. In this example, in the initial state, it is assumed that the interconnection switch SW1 provided between the distribution line 4a and the distribution line 4b is in an open state. In addition, it is assumed that the interconnection switch SW2 provided between the distribution line 4b and the distribution line 4c is in an open state.

FIG. 2 is a diagram illustrating the configuration of the protective relay according to the present embodiment.
Referring to FIG. 2, here, protective relays 5, 6, 7, and 8 have the same configuration, and include an open / close control unit 9a and a communication unit 9b.

  The opening / closing control unit 9a is a part that controls the opening / closing operation of the corresponding switch. The communication unit 9b executes communication processing with the control device 10 provided to be communicable. Specifically, the communication unit 9b receives an open / close control signal from the control device 10 and outputs the open / close control signal to the open / close control unit 9a. The open / close control unit 9a performs an open / close operation on the switch according to the open / close control signal. Run.

FIG. 3 is a schematic block diagram illustrating a configuration of control device 10 according to the present embodiment.
Referring to FIG. 3, control device 10 includes a communication unit 12, a CPU (Central Processing Unit) 14, a memory 19, an input unit 18, and an internal bus 20. Each unit is connected to the internal bus 20.

The communication unit 12 is provided so as to be able to communicate with the communication unit 9b of the protective relays 5, 6, 7, and 8.
The CPU 14 executes processing to be described later by executing a program stored in the memory 19. The memory 19 is also used as a work area for the CPU 14.

  The input unit 18 is a part where an operator (administrator) inputs data or the like via a mouse or a keyboard.

  FIG. 4 is a process flow diagram for executing the distribution pattern selection method for the distribution system according to the present embodiment.

  The processing flow is realized by the CPU 14 of the control device 10 executing a program stored in the memory 19. In this example, a description will be given of a method of selecting an accommodation pattern that allows power to be interchanged for sections other than the accident section when an accident section occurs in a certain distribution line. In addition, the present invention can be similarly applied to a work section when work other than an accident needs to be performed.

  Referring to FIG. 4, first, the voltage / tidal current distribution of all distribution lines connected to the interchange section (healthy power outage section) that accommodates the distribution line where the accident has occurred is calculated by tidal calculation (step) S1).

  Next, the interchange pattern candidates to be calculated are sequentially extracted from all the interchange pattern candidates that can be transmitted to the interchange section (step S2).

  Next, the resistance R and reactance X from the circuit breaker of the distribution source distribution line to the interconnection switch serving as the accommodation point are calculated (step S3).

  Next, the total values P and Q of the active power and reactive power in the accommodation section of the accommodation pattern candidate are calculated (step S4).

  Next, the voltage after accommodation of the interconnection switch of the accommodation pattern candidate is evaluated (step S5). Specifically, the voltage change of the interconnection switch that is the interconnection point when the active power P and the reactive power Q in the interchange section are connected is calculated.

  Next, it is determined whether or not the voltage after interchange of the interconnection switch is within a range for selecting an interchange pattern candidate (step S6).

  If it is determined in step S6 that the voltage after the interchange of the interconnection switch is within the range for selecting an accommodation pattern candidate (YES in step S6), the accommodation pattern candidate is registered as an accommodation pattern (step S7). ).

  On the other hand, if it is determined in step S6 that the voltage after interchange of the interconnection switch is not within the range for selecting an accommodation pattern candidate (NO in step S6), step S7 is skipped.

Next, it is determined whether or not there is another accommodation pattern candidate (step S8).
If it is determined in step S8 that there is another accommodation pattern candidate (YES in step S8), another accommodation pattern candidate is extracted (step S9). And it returns to step S5 and the voltage after the interchange of the interconnection switch of the said accommodation pattern candidate is evaluated again, and it is judged whether it registers as an accommodation pattern candidate.

  If it is determined in step S8 that there is no other accommodation pattern candidate (NO in step S8), detailed voltage / tidal current distribution calculation after accommodation is obtained by tidal calculation for the registered accommodation pattern (step S8). S10). The detailed tidal current calculation is performed in the load state of two cross sections as described above in consideration of the distance of the distribution line at the time of interchange and the variation of the load.

  And the best accommodation pattern is determined from the accommodation patterns registered based on the calculation result in step S10 (step S11).

Then, the process ends (END).
FIG. 5 is a diagram for explaining a range for selecting an accommodation pattern candidate according to the present embodiment.

  Referring to FIG. 5, here, a case where an upper limit value VU and a lower limit value VL are defined is shown. The upper limit value VU and the lower limit value VL are values obtained by converting the upper limit value 107V determined by the Electric Power Business Act into a high voltage, and VL is a value obtained by converting the lower limit value 95V into a high voltage.

  In this example, when the upper limit value VU1 of the accommodation pattern candidate selection criterion and the lower limit value VL1 of the accommodation pattern candidate selection criterion are set with some margin to the upper limit value VU and the lower limit value VL, It is shown. A range between the upper limit value VU1 and the lower limit value VL1 is a first range in this example.

  Further, regarding the range between the upper limit value VU and the lower limit value VL, the region other than the first range, that is, the range between the upper limit value VU and the upper limit value VU1, and between the lower limit value VL1 and the lower limit value VL. Let the range be the second range.

  In this example, three states A to C are shown as an example, and when the interchanged voltage is determined as states A and C as selection criteria for the interchange pattern candidate, it is not registered as an interchange pattern. On the other hand, when the voltage after accommodation is determined as the state B, it is registered as an accommodation pattern.

  FIG. 6 is a diagram illustrating a specific example of a method for determining an accommodation pattern when the second section of the distribution line 4b in FIG. 1 is an accident section.

  Referring to FIG. 1, in this case, sections 3 to 7 of distribution line 4b are accommodation sections, and distribution lines 4a and 4c connected to the accommodation section by interconnection switches SW1 and SW2 serve as accommodation sources. It becomes the distribution line.

  Then, according to the flowchart shown in FIG. 4, in the process of step S <b> 1, the voltage / tidal current distribution of the distribution lines 4 a and 4 c that become the distribution source distribution lines is calculated by tidal calculation. It is assumed that the memory 19 of the control device 10 stores in advance various data necessary for calculating the voltage / power flow distribution. Specifically, it is assumed that data of information such as a connection relationship of the power distribution system 1 in FIG. The accident section may be automatically determined and detected, or the accident section may be detected by input via the input unit 18.

Then, in the process of step S2, an accommodation pattern candidate is extracted.
With reference to FIG. 6A, in the case of this example, the accommodation pattern candidates are the following six patterns. In addition, in this example, the case where electric power is interchanged as an example will be described as an example for all the three to seven sections of the distribution line 4b.

  Interchange pattern candidate 1: For the distribution line 4a, power is transmitted from the interconnection switch SW1 to the sections 3 to 7 of the distribution line 4b, and for the distribution line 4c, no power is transmitted from the interconnection switch SW2 to the distribution line 4b (interconnection switch) The switch SW1, the section switches 16c to 16f are closed, and the interconnection switch SW2 is opened).

  Interchange pattern candidate 2: For the distribution line 4a, power is transmitted from the interconnection switch SW1 to the sections 3 to 6 of the distribution line 4b, and for the distribution line 4c, transmission is performed from the interconnection switch SW2 to the seven sections of the distribution line 4b (interconnection) The switches SW1 and SW2 and the section switches 16c to 16e are closed and the section switch 16f is opened).

  Conformity pattern candidate 3: For the distribution line 4a, power is transmitted from the interconnection switch SW1 to the third to fifth sections of the distribution line 4b, and for the distribution line 4c, power is transmitted from the interconnection switch SW2 to the sixth and seventh sections of the distribution line 4b ( The interconnection switches SW1 and SW2 and the division switches 16c to 16d and 16f are closed, and the division switch 16e is opened.

  Conformity pattern candidate 4: For the distribution line 4a, power is transmitted from the interconnection switch SW1 to the sections 3 and 4 of the distribution line 4b, and for the distribution line 4c, power is transmitted from the interconnection switch SW2 to the sections 5 to 7 of the distribution line 4b ( The interconnection switches SW1 and SW2, the section switches 16c, 16e, and 16f are closed, and the section switch 16d is opened).

  Candidate pattern 5: For the distribution line 4a, power is transmitted from the interconnection switch SW1 to the three sections of the distribution line 4b, and for the distribution line 4c, power is transmitted from the interconnection switch SW2 to the four to seven sections of the distribution line 4b. The switches SW1 and SW2 and the section switches 16d to 16f are closed and the section switch 16c is opened).

  Interchange pattern candidate 6: No power is transmitted from the interconnection switch SW1 to the distribution line 4b with respect to the distribution line 4a, and power is transmitted from the interconnection switch SW2 to the section 3-7 of the distribution line 4b with respect to the distribution line 4c (interconnection switch) SW2, the division switches 16c to 16f are closed, and the interconnection switch SW1 is opened).

  Next, in the process of step S3, the resistance R and reactance X from the distribution line 4a of the interchange source to the interconnection switch SW1 are calculated. Moreover, the resistance R and reactance X from the distribution line 4c of the interchange source to the interconnection switch SW2 are calculated.

  FIG. 6B shows the calculated resistance R and the calculated reactance X for the interconnection switches SW1 and SW2. Further, the voltage V1 in the interconnection switch before interchange calculated by the power flow calculation of the voltage / power flow distribution is also shown.

Next, in the process of step S4, the total values P and Q of the active power and reactive power in the accommodation section are calculated. For example, in the case of the accommodation pattern candidate 1, the total values P and Q are as follows.
P = P3 + P4 + P5 + P6 + P7
Q = Q3 + Q4 + Q5 + Q6 + Q7

Next, in the process of step S5, a voltage is calculated when the voltage V1 of the interconnection switch SW1 before accommodation calculated in step S1 and the total values P and Q of the accommodation sections obtained in step S4 are connected. To do. The voltage V2 when P and Q are connected is as follows.
V2 = V1-ΔV
ΔV = (R · P + X · Q) / V1

  Next, in step S6, it is determined whether or not the voltage V2 calculated in step S5 is within a range for selecting an accommodation pattern candidate.

  That is, it is determined whether or not the voltage V2 is included in the first range described with reference to FIG.

  For example, when the voltage V2 is included in the first range as in the state B, it is registered as an accommodation pattern. In this example, as an example, it is assumed that the lower limit value VL1 is set to 6400V and the upper limit value VU1 is set to 6700V.

  With respect to the distribution line 4a, the voltage V2 of the accommodation pattern candidate 1 is 6545V and is included in the first range.

  Regarding the distribution line 4c, the voltage V2 of the accommodation pattern candidate 1 has the same value as the voltage V1 because it does not accommodate. Accordingly, both the distribution lines 4a and 4c are registered in the accommodation pattern because they are both within the range for selecting the accommodation pattern candidate.

The other procedure pattern candidates are determined in the same procedure.
In the case of the accommodation pattern candidates 2 and 3, as with the accommodation pattern candidate 1, the voltage V2 is included in the first range. Therefore, it is registered in the accommodation pattern.

  On the other hand, in the case of the accommodation pattern candidates 4 to 6, the voltage V2 of the interconnection switch SW1 on the distribution line 4a side is included in the first range, but the voltage V2 of the interconnection switch SW2 on the distribution line 4c side. Is not included in the first range. Therefore, the accommodation pattern candidate is not registered as an accommodation pattern.

  And in the process of step S10, in order to evaluate whether or not the deviation of the upper and lower limits of the voltage occurs in the distribution system after the accommodation for the registered accommodation pattern, there is a possibility that the deviation of the upper limit value of the voltage occurs. The calculation process is executed with two cross sections of a load condition in which there is a possibility that a deviation from the lower limit value of the voltage may occur. Note that the load state where the deviation of the upper limit value of the voltage may occur is a light load and the amount of power generation is large, and the load condition where the deviation of the lower limit value of the voltage may occur is This is the case where the power generation amount is small at the load.

  Then, in the process of step S11, the best accommodation pattern is determined from the registered accommodation patterns that have been confirmed not to deviate. As the determination method of the best accommodation pattern, as an example, a case where a pattern having a large margin value from the upper limit value VU1 and the lower limit value VL1 is determined as an accommodation pattern with a low possibility of deviation. Has been. In addition, as the determination method, it is also possible to perform the comparative evaluation based on evaluation criteria such as the number of switch operations and the minimum distribution line loss, and to determine the best accommodation pattern.

  The method of selecting the interchange pattern of the distribution system according to the present invention uses the power flow calculation in the voltage / current distribution check when selecting the best interchange pattern from among the interchange pattern candidates, and for the interchange pattern candidate, Based on the active power and reactive power, an accommodation pattern candidate that may cause a deviation of the upper and lower limits of the voltage after accommodation is excluded from the accommodation pattern in advance. For the accommodation pattern that is unlikely to deviate from the upper and lower voltage limits after accommodation, the best accommodation pattern is determined after calculating the voltage and current distribution by power flow calculation. Therefore, it is possible to efficiently derive an interchange pattern of the distribution system that does not cause the deviation of the upper and lower voltage limits in the system power supply with a processing time that does not hinder the operation.

(Modification)
FIG. 7 is a process flow diagram for executing the method for selecting the interchange pattern of the distribution system according to the modification of the present embodiment.

  Referring to FIG. 7, the difference from the flow of FIG. 4 is that steps S12 to S14 are further added.

  Specifically, when it is determined in step S6 whether the voltage after accommodation is within the pattern selection reference value and it is determined that the voltage after accommodation of the interconnection switch is not within the range for selecting the accommodation pattern candidate ( In step S6, it is determined whether or not the voltage after accommodation is within a specified range (step S12).

  Next, when it is determined that the voltage after accommodation is within the specified range (YES in step S12), the voltage tendency is analyzed (step S13).

Next, it is determined whether or not there is a possibility of exceeding the specified range (step S14).
If it is determined in step S14 that there is a possibility of exceeding the specified range (YES in step S14), the process proceeds to step S8 without registering the accommodation pattern candidate.

  On the other hand, if it is determined in step S14 that there is no possibility of exceeding the specified range (NO in step S14), the accommodation pattern candidate is registered as an accommodation pattern (step S7).

  If it is determined in step S12 that the voltage after accommodation is not within the specified range (NO in step S12), the process proceeds to step S8 without registering the accommodation pattern candidate.

  Since the subsequent processing is the same as that described in the flowchart of FIG. 4, detailed description thereof will not be repeated.

  FIG. 8 is a diagram for explaining a range for selecting accommodation pattern candidates according to a modification of the present embodiment.

  Referring to FIG. 8, here, a case where an upper limit value VU and a lower limit value VL are defined is shown. The upper limit value VU and the lower limit value VL are values obtained by converting the upper limit value 107V determined by the Electric Power Business Act into a high voltage, and VL is a value obtained by converting the lower limit value 95V into a high voltage.

  In this example, when the upper limit value VU1 of the accommodation pattern candidate selection criterion and the lower limit value VL1 of the accommodation pattern candidate selection criterion are set with some margin to the upper limit value VU and the lower limit value VL, It is shown. A range between the upper limit value VU1 and the lower limit value VL1 is a first range in this example.

  Further, regarding the range between the upper limit value VU and the lower limit value VL, the region other than the first range, that is, the range between the upper limit value VU and the upper limit value VU1, and between the lower limit value VL1 and the lower limit value VL. Let the range be the second range.

When the voltage of the accommodation pattern candidate is included in the second range, the voltage tendency is analyzed.
In this modification, as a method of analyzing the voltage trend, the resistance R calculated for the interconnection switches SW1 and SW2, the calculated value of the reactance X, and the total values P and Q of the active power and reactive power in the interchange section are given. Is used.

Specifically, (R · P + X · Q) is calculated and its sign is determined.
When the voltage V2 of the accommodation pattern candidate is within the second range between the upper limit value VU and the upper limit value VU1, if (R · P + X · Q) is positive, the accommodation pattern candidate is registered as the accommodation pattern. To do. On the other hand, if (R · P + X · Q) is negative, the accommodation pattern candidate is excluded from the accommodation pattern.

  With respect to the interconnecting switches SW1 and SW2, it is determined whether the voltage fluctuation of the interconnecting switch approaches or moves away from the upper limit value of the voltage by connecting P and Q in the interchange section. If there is an increasing tendency according to the sign, the accommodation pattern candidate is excluded, and if there is a downward tendency, the accommodation pattern candidate is registered.

  Similarly, when the voltage V2 of the accommodation pattern candidate is within the second range between the lower limit value VL and the lower limit value VL1, if (R · P + X · Q) is negative, the accommodation pattern candidate is accommodated. Register as a pattern. On the other hand, if (R · P + X · Q) is positive, the accommodation pattern candidate is excluded from the accommodation pattern.

  With respect to the interconnection switches SW1 and SW2, it is determined whether the voltage fluctuation of the interconnection switch approaches or moves away from the lower limit value of the voltage by connecting P and Q in the interchange section. If there is a downward trend according to the sign, the accommodation pattern candidate is excluded, and if there is an upward trend, the accommodation pattern candidate is registered.

  According to the method, as a selection criterion for an accommodation pattern candidate, a voltage tendency is analyzed even for a voltage exceeding the first range between the upper limit value VU1 and the lower limit value VL1, that is, a voltage included in the second range. The accommodation pattern candidates that are determined not to exceed the upper limit value VU or the lower limit value VL are registered as accommodation patterns.

  As a result, when there are few accommodation pattern candidates selected in the first range, it is possible to determine the best accommodation pattern using the accommodation pattern candidates selected in the second range. It is possible to take more flexible measures regarding the selection method of the system accommodation pattern.

  As described above, the method for selecting the interchange pattern of the distribution system according to the present invention is based on the active power and reactive power in the section to be accommodated, and the voltage change in the interconnected switch after the interchange and the voltage in the section to be accommodated tend to increase. By checking whether there is a tendency to decrease or not, the candidate for the accommodation pattern is narrowed down, and the distribution of voltage and power flow after accommodation is calculated by power flow calculation. Therefore, there is an effect that it is possible to calculate the voltage and power flow of the distribution system connected to the distributed power source such as photovoltaic power generation with high accuracy and efficiency.

  As an application example of the present invention, the calculation of interchange at the time of an accident or at the time of switching the distribution system at the time of working has been described, but even at the stage of the distribution system planning to examine the configuration of the distribution system, etc. It can also be used to evaluate the distribution of voltage and power flow in the distribution system plan when checking for possible inconvenience during work.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Distribution system system, 2a-2c transformer, 3a-3c circuit breaker, 4a-4c distribution line, 5a-5f, 6a-6f, 7a-7f, 8a, 8b Protection relay, 9a Opening / closing control part 9b, 12 Communication part DESCRIPTION OF SYMBOLS 10 Control apparatus, 14 CPU, 15a-15f, 16a-16f, 17a-17f Division switch, 18 input part, 19 Memory, 20 Internal bus, SW1, SW2 Linkage switch.

Claims (6)

In the distribution system in which a plurality of distribution lines connected to the system power supply are divided into a plurality of sections by a plurality of switches, and at least one interconnection switch for electrically connecting the distribution lines to each other is provided. For a predetermined section of the distribution line, a method for selecting an interchange pattern of a distribution system for selecting an interchange pattern for accommodating power from another distribution line via the interconnection switch,
Extracting a plurality of accommodation patterns of the power distribution system capable of accommodating power to the predetermined section via the interconnection switch;
Regarding the extracted accommodation pattern, calculating a resistance and reactance from the system power supply to the interconnection switch;
Calculating the voltage of the interconnection switch based on the calculated resistance and reactance and the active power and reactive power in the predetermined section in the plurality of accommodation patterns;
Extracting an accommodation pattern that satisfies a voltage condition within a predetermined range from the plurality of accommodation patterns based on the calculation result; and
Selecting a suitable accommodation pattern from among the extracted accommodation patterns.   The method for selecting an interchange pattern of a power distribution system according to claim 1, wherein the predetermined range corresponds to a first range narrower than a prescribed upper and lower limit value. Extracting an accommodation pattern that satisfies a voltage condition within the predetermined range,
Analyzing the voltage tendency when the calculated voltage is included in a second range other than the first range, which is narrower than the prescribed upper and lower limit values;
The method for selecting an interchange pattern of a distribution system according to claim 2, further comprising: extracting an interchange pattern based on the analysis result. In the distribution system in which a plurality of distribution lines connected to the system power supply are divided into a plurality of sections by a plurality of switches, and at least one interconnection switch for electrically connecting the distribution lines to each other is provided. An apparatus for selecting an accommodation pattern for a distribution system for selecting an accommodation pattern for accommodating power from another distribution line via the interconnection switch for a predetermined section of the distribution line,
A first extraction unit for extracting a plurality of accommodation patterns of the power distribution system capable of accommodating power with respect to the predetermined section via the interconnection switch;
A first calculation unit that calculates a resistance and reactance from the system power supply to the interconnection switch with respect to the accommodation pattern extracted by the first extraction unit;
A second calculation unit that calculates the voltage of the interconnection switch based on the resistance and reactance calculated by the first calculation unit and active power and reactive power in the predetermined section in the plurality of accommodation patterns; ,
A second extraction unit that extracts an accommodation pattern satisfying a voltage condition within a predetermined range from the plurality of accommodation patterns based on the calculation result calculated by the second calculation unit;
An apparatus for selecting an accommodation pattern of a distribution system, comprising: a selection unit that selects a suitable accommodation pattern from the accommodation patterns extracted by the second extraction unit.   The apparatus for selecting an interchange pattern of a power distribution system according to claim 4, wherein the predetermined range corresponds to a first range narrower than a prescribed upper and lower limit value. The second extraction unit includes
An analyzer that analyzes a voltage trend when the calculated voltage is included in a second range other than the first range, which is narrower than the prescribed upper and lower limit values;
The distribution pattern selection device for a power distribution system according to claim 5, further comprising a third extraction unit that extracts the accommodation pattern based on the analysis result.

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