JP5960111B2 - Position estimating apparatus and position estimating method - Google Patents

Description

  The present invention relates to a position estimation device and a position estimation method.

  For example, a three-phase distribution line in which voltage imbalance occurs is known (for example, Patent Document 1).

JP 2012-228045 A

  Generally, when voltage imbalance occurs in a three-phase distribution line including the three-phase distribution line of Patent Document 1, a malfunction of a load connected to the three-phase distribution line may be caused depending on the degree of voltage imbalance. Therefore, in order to eliminate the voltage imbalance, it is necessary to estimate the position of the causative load that causes the voltage imbalance. The position of the causal load is estimated based on a voltage imbalance rate calculated from, for example, an actually measured voltage value at a position corresponding to the position where the load in the three-phase distribution line is connected. When multiple loads are connected to a three-phase distribution line, measurement of the voltage at the position corresponding to the position where each load is connected becomes complicated, and it may be difficult to estimate the position of the cause load .

The main present invention for solving the above-described problem is that the upstream side of the first and second loads connected to any two phases of the three phases in the section between the first and second positions of the three-phase distribution line. A first arithmetic unit that calculates a value of a negative-phase divided voltage at the first position as a first negative-phase divided voltage value based on a voltage value at the first position; and a first negative-phase divided current at the first position Value, the current value of the second negative phase at the second position downstream of the first and second loads, and the value of the line impedance of the three-phase distribution line in the section between the first and second positions And a second arithmetic unit that calculates the value of the negative phase divided voltage at the first position as the second negative phase divided voltage value based on the information indicating the position of the node to which the first and second loads are connected. And the cause of voltage imbalance in the three-phase distribution line based on the first and second negative phase divided voltage values An estimation device for estimating the position of the cause load that Tsu, a position estimation device characterized by comprising a.

  Other features of the present invention will become apparent from the accompanying drawings and the description of this specification.

  According to the present invention, the position of the causative load can be estimated.

It is a figure which shows the power distribution system in embodiment of this invention. It is a block diagram which shows the hardware of the position estimation apparatus in embodiment of this invention. It is a block diagram which shows the position estimation apparatus in embodiment of this invention. It is a figure which shows the voltage imbalance rate of the distribution line in embodiment of this invention. It is a figure which shows the electric current value of the distribution line in embodiment of this invention. It is a figure which shows a part of distribution system in embodiment of this invention. It is a flowchart which shows operation | movement of the position estimation apparatus in embodiment of this invention.

  At least the following matters will become apparent from the description of this specification and the accompanying drawings.

=== Distribution system ===
Hereinafter, the power distribution system in the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing a power distribution system in the present embodiment.

  The distribution system 100 is a power system for supplying power from the substation 200 to the loads R1 to R4. The distribution system 100 includes a substation 200, a position estimation device 3, a distribution line L100 (three-phase distribution line), switches LS1 to LS3, and loads R1 to R4.

  Note that although a plurality of switches are provided in the power distribution system 100, for example, three switches are provided for convenience of explanation. Further, although a plurality of loads are provided in the power distribution system 100, for example, four loads are provided for convenience of explanation. In the second switch section, three loads R1 to R3 are described. For example, only the loads R1 and R2 may be connected.

  The substation 200 is, for example, a distribution substation that steps down the power supplied from the upstream side and supplies the stepped down power to the distribution line L100. The substation 200 has a distribution transformer 101.

  The distribution transformer 101 is a device that transforms, for example, a primary side voltage at a predetermined transformation ratio and outputs the transformed voltage from the secondary side. The distribution transformer 101 is assumed to have a transformation ratio set so that, for example, a voltage of 66 kilovolts is transformed to a voltage of 6.6 kilovolts. The primary side of distribution transformer 101 is connected to one end of transmission line L200. The power transmission line L200 is a power transmission line for supplying a voltage of 66 kilovolts from an upstream primary substation (not shown) to the downstream substation 200, for example. The secondary side of distribution transformer 101 is connected to one end of distribution line L100.

  The distribution line L100 is a power line for supplying power from the substation 200 to the loads R1 to R4, and extends from the upstream substation 200 toward the downstream side. Distribution line L100 is a three-phase distribution line for supplying U-phase, V-phase, and W-phase three-phase AC power from substation 200. The distribution line L100 includes a distribution line L1 that supplies U-phase power, a distribution line L2 that supplies V-phase power, and a distribution line L3 that supplies W-phase power.

  The switches LS1 to LS3 are switches with a measurement function, for example, provided at predetermined positions in the distribution line L100. Each of the switches LS1 to LS3 measures the line current, the line voltage, and the power factor of each phase of the distribution line L100 at positions where the switches LS1 to LS3 are provided, and shows the measurement results. Signals S1 to S3 are output at regular intervals. The distribution line L100 is divided into a plurality of switch sections by the switches LS1 to LS3. A section between the switches LS1 and LS2 is referred to as a first switch section, and a section between the switches LS2 and LS3 is also referred to as a second switch section.

  The loads R1 to R4 are power loads connected to the distribution line L100. The loads R1 to R4 are connected to positions corresponding to the nodes 71 to 74, respectively. The loads R1 to R4 are loads provided in, for example, factories or the like whose power consumption changes according to a time zone in one day. The loads R1 to R4 are connected to any two-phase (two) distribution lines among the distribution lines L1 to L3, respectively, and are supplied with electric power. That is, the loads R1 to R4 are connected to any of the UV phases of the distribution lines L1 and L2, the VW phases of the distribution lines L2 and L3, and the WU phases of the distribution lines L3 and L1, respectively.

  The position estimation device 3 is a device that estimates the position of a source load (cause load) that is a source of voltage imbalance in the distribution line L100. The generation source load is a degree of influence on the voltage unbalance rate of the distribution line L100 among loads (for example, loads R1 to R4) connected to the distribution line L100 (also referred to as “influence degree”). ) Indicates the largest load. That is, the generation source load indicates a load that causes the occurrence of voltage imbalance in the distribution line L100. For example, when the influence degree of the load R1 is the largest among the loads R1 to R4, the load R1 becomes the source load.

=== Voltage imbalance ===
Hereinafter, voltage imbalance in the present embodiment will be described with reference to FIG.

<Voltage imbalance and voltage imbalance ratio>
Voltage imbalance means that the amplitude of each phase voltage is different or the phase voltage is out of phase in a three-phase AC voltage in which the phase voltage has the same amplitude and the phase voltage has a phase difference of 120 °. .

  When voltage imbalance occurs in the distribution line L100, the amplitudes of the voltages of the distribution lines L1 to L3 become different from each other, or the phase difference of the voltages of the distribution lines L1 to L3 deviates from 120 °. When a voltage imbalance occurs in the distribution line L100, the loads R1 to R4 are not supplied to the loads R1 to R4 according to the degree of the voltage imbalance, for example, because the voltages at which the loads R1 to R4 are normally operated May cause malfunction. Therefore, when the voltage unbalance rate indicating the degree of voltage unbalance in the distribution line L100 becomes larger than a predetermined value, the factor causing the voltage unbalance rate to be larger than the predetermined value is grasped, and the voltage unbalance rate is decreased. Need to be renovated.

The voltage imbalance ratio ε is represented by the ratio of the negative phase voltage (also referred to as “negative phase divided voltage”) to the positive phase voltage, for example, as shown in Equation 1 below. In addition, a normal phase voltage and a negative phase voltage are calculated | required by the symmetrical coordinate method, for example using the phase voltage of the distribution line L100.

<Source of voltage imbalance>
The voltage imbalance occurs based on the phase to which the loads R1 to R4 are connected, the positions of the loads R1 to R4, and the power consumption of the loads R1 to R4. For example, among the loads R1 to R4, the power consumption of the load R1 is larger than the power consumption of the loads R2 to R4, the power consumption of the load R1 is relatively large, and the power consumption of the loads R2 to R4 When the amount is relatively small, a relatively large value of power is supplied from the distribution line L100 to the load R1. In this case, a voltage unbalance with a voltage unbalance rate corresponding to the power consumption of the load R1 occurs. In this case, for example, the load R1 becomes the source load.

=== Position estimation device ===
Hereinafter, with reference to FIG.2 and FIG.3, the position estimation apparatus in this embodiment is demonstrated. FIG. 2 is a block diagram showing hardware of the position estimation apparatus in the present embodiment. FIG. 3 is a block diagram showing the position estimation apparatus in the present embodiment.

  The position estimation device 3 is a device that estimates the position of the source load. The position estimation device 3 includes a CPU (Central Processing Unit) 31, a communication device 32, a storage device 33, a display device 34, and an input device 35. The CPU 31 implements various functions of the position estimation device 3 by executing a program stored in the storage device 33 and controls the position estimation device 3 in an integrated manner. The storage device 33 stores the above-described program and various types of information. The display device 34 is a display that displays information of the position estimation device 3. The input device 35 is, for example, a keyboard or a mouse for inputting information to the position estimation device 3. The communication device 32 communicates with the switches LS1 to LS3 via the network 300.

  The position estimation device 3 further includes a detection unit 36 (detection device), an estimation unit 37 (first to fifth arithmetic devices, estimation device), and a notification unit 38 (also referred to as “various functions of the position estimation device 3”). The various functions of the position estimation device 3 are realized by the CPU 31 executing programs stored in the storage device 33.

  The detection part 36 detects the switch area estimated that the source load is connected.

  The estimation unit 37 estimates the position of the source load in the switch section indicated in the detection result of the detection unit 36.

  The notification unit 38 (notification device) notifies information about the source load based on the estimation result of the estimation unit 37.

=== Detector ===
Hereinafter, the detection unit in the present embodiment will be described with reference to FIGS. 1, 4, and 5.

  FIG. 4 is a diagram illustrating the voltage imbalance rate of the distribution lines in the present embodiment. In FIG. 4, the voltage imbalance rate at each position where the switches LS1 to LS3 are provided in the distribution line L100 is indicated by a solid line, a broken line, and a one-dot chain line. FIG. 4 is shown based on the calculation result of the detection unit 36.

  FIG. 5 is a diagram illustrating a current value of the distribution line in the present embodiment. In FIG. 5, current values at positions where the switches LS <b> 1 to LS <b> 3 are provided in the distribution line L <b> 100 are indicated by solid lines, broken lines, and alternate long and short dash lines. In FIG. 5, for example, the value of the line current in the U phase is shown. FIG. 5 is shown based on the measurement results of the switches LS1 to LS3.

<Detection of voltage imbalance>
The detector 36 applies the information shown in the measurement signals S1 to S3 to Equation 1, and calculates the voltage imbalance rate at each position where the switches LS1 to LS3 are provided. Note that a symmetric coordinate method may be used in calculating the voltage imbalance rate. The detection unit 36 calculates a voltage unbalance rate every time the measurement signals S1 to S3 output at regular time intervals are received, for example, calculates a voltage unbalance rate at each time in one day.

  The detection unit 36 determines whether or not the calculated voltage imbalance rate exceeds a predetermined value (for example, 3%). When the voltage imbalance rate exceeds a predetermined value, the detection unit 36 detects that a voltage imbalance has occurred in the distribution line L100. On the other hand, when the voltage unbalance rate does not exceed the predetermined value, the detection unit 36 does not detect that the voltage unbalance has occurred in the distribution line L100.

<Detection of switch section>
Based on information (for example, the value of the line current) indicated in the measurement signals S1 to S3, the detection unit 36 is a switch section ("source estimation section") estimated to be connected to the source load. Detected).

  Specifically, the detection unit 36 is a difference value (also referred to as “first current difference value”) between the value of the line current indicated in the measurement signal S1 and the value of the line current indicated in the measurement signal S2. ) Is larger than a determination current threshold value. Further, the detection unit 36 has a difference value (also referred to as “second current difference value”) between the value of the line current indicated in the measurement signal S2 and the value of the line current at the position where the switch LS3 is provided. Is greater than the determination current threshold.

  Note that the value of the line current indicated in each of the measurement signals S1 to S3 may be, for example, an effective value or a peak peak value. The determination current threshold is a value compared with the first and second current difference values, and may be, for example, about 20% of the rated current value of the distribution line L100, or a predetermined value other than 20%. It may be a value. Further, the determination current threshold value may be determined based on a predetermined simulation. In this case, for example, when the load having the maximum capacity among the loads R1 to R4 is connected to the first switch section, the line current value and distribution at the position where the switch LS1 is provided in the distribution line L100. A value corresponding to a difference value (also referred to as “first calculation value”) with the value of the line current at the position where the switch LS2 is provided in the electric wire L100 may be determined as the determination current threshold value. In this case, for example, the value of the line current at the position where the switch LS1 is provided in the distribution line L100 when the load having the maximum capacity among the loads R1 to R4 is connected to the second switch section. And a value corresponding to a difference value (also referred to as “second calculation value”) between the line current value at the position where the switch LS <b> 2 is provided in the distribution line L <b> 100 may be determined as the determination current threshold value. . Further, a value corresponding to the average value of the first and second calculation values may be determined as the determination current threshold value.

  When detecting that the voltage imbalance has occurred in the distribution line L100, the detection unit 36 generates a section corresponding to a difference value larger than the determination current threshold value among the first current difference value and the second current difference value. Detect as source estimation interval.

  Specifically, when it is detected that a voltage imbalance has occurred in the distribution line L100, the first current difference value is larger than the determination current threshold value, and the second current difference value is smaller than the determination current threshold value The detecting unit 36 detects the first switch section as the source estimation section. Further, when it is detected that a voltage imbalance has occurred in the distribution line L100, if the second current difference value is larger than the determination current threshold value and the first current difference value is smaller than the determination current threshold value, the detection unit 36 detects the second switch section as the source estimation section. In addition, when the detection part 36 does not detect that voltage imbalance has occurred in the distribution line L100, regardless of the comparison result between the first current difference value and the second current difference value and the determination current threshold value, in the distribution line L100. The source estimation section is not detected on the assumption that no voltage imbalance has occurred.

  Note that the detection unit 36 detects the source estimation section based on the first current difference value, the second current difference value, and the like for the U-phase, V-phase, and W-phase line currents.

  For example, in the case of the voltage unbalance rate and the line current value shown in FIGS. 4 and 5, the detection unit 36 detects the second switch section as the source estimation section.

=== Estimation unit, Notification unit ===
Hereinafter, with reference to FIG.1 and FIG.6, the estimation part and alerting | reporting part in this embodiment are demonstrated. FIG. 6 is a diagram illustrating a part of the power distribution system in the present embodiment. The switch LSi corresponds to the switch LS2, and the switch LSj corresponds to the switch LS3 on the downstream side of the switch LS2. The loads RA, RB, and RC correspond to the loads R1, R2, and R3, respectively, and the nodes 7A, 7B, and 7C correspond to the nodes 71, 72, and 73, respectively.

= Estimator =
The estimation unit 37 selects a load estimated as the source load from among the loads provided in the source estimation section detected by the detection unit 36. In addition, it demonstrates as the 2nd switch area between switches LS2 and LS3 being detected as a generation source estimation area.

  The estimation unit 37 calculates the value of the reverse phase voltage at the position where the switch LSi is provided by using the first calculation method and the second calculation method as different calculation methods, Based on this, the position of the source load is estimated.

<First calculation method>
The estimation unit 37 reverses the position where the switch LSi is provided based on the information (for example, the value of the line voltage) indicated in the measurement signal S2 output from the switch LS2 as the switch LSi. A first negative phase divided voltage value V2i is calculated as the phase divided voltage value. The estimation unit 37 may calculate the first negative phase voltage value V2i using, for example, a symmetric coordinate method, or may be a predetermined value indicating the relationship between the line voltage value and the negative phase voltage value. The first negative phase divided voltage value V2i may be calculated based on the relational expression.

<Second calculation method>
Based on the system information included in the various types of information stored in the storage device 33 and Equations 2 to 4, the estimation unit 37 uses the second inverse as the value of the reverse phase voltage at the position where the switch LSi is provided. The phase voltage value is calculated.

  The system information includes, for example, information indicating the positions of the switches LS1 to LS3, information indicating the positions to which the loads R1 to R4 are connected (positions of the nodes 71 to 74), and the lines per unit length of the distribution line L100. Information indicating the impedance value, information indicating the length of the distribution line L100, and the like are included. Further, the system information includes information indicating the nominal voltage of the distribution line L100, the capacities of the loads R1 to R4, and the power consumption amounts of the loads R1 to R4. In the system information, in addition to the above information, the first negative phase current value as the value of the negative phase current at the position where the switch LSi is provided, and the negative phase at the position where the switch LSj is provided. Other information for calculating the second negative phase current value as the current value and the third negative phase voltage value as the negative phase voltage value at the position where the switch LSj is provided is also included. Suppose that The system information may be input from the input device 35 based on the design specifications of the power distribution system 100, the field survey of the power distribution system 100, and the like.

  The estimation unit 37 calculates the first and second negative phase current values and the third negative phase voltage value based on the system information. In addition, the estimation part 37 is good also as calculating these values, for example using a symmetrical coordinate method. Thereafter, the estimation unit 37 applies the calculated first and second negative phase divided current values and the third negative phase divided voltage value to Equations 2 to 4 to obtain the second negative phase divided voltage value V2i (A ), V2i (B), V2i (C) are calculated.

  The second negative phase divided voltage value V2i (A) indicates the second negative phase divided voltage value when the load RA is assumed to be the source load. The second negative phase divided voltage value V2i (B) indicates the second negative phase divided voltage value when the load RB is assumed to be the source load. The second negative phase divided voltage value V2i (C) indicates the second negative phase divided voltage value when the load RC is assumed to be the source load.

V2i (A) = V2j + I2j * Z (Li-La) + I2i * Z (La) (Formula 2)
V2i (B) = V2j + I2j * Z (Li-Lb) + I2i * Z (Lb) (Formula 3)
V2i (C) = V2j + I2j * Z (Li-Lc) + I2i * Z (Lc) (Formula 4)
Note that Z (La) and Z (Li-La) are values of the line impedance between the node 7A and the position where the switch LSi is provided in the distribution line L100, respectively, and the node 7A and the switch LSj are provided. The line impedance value between the two positions is shown. Z (Lb) and Z (Li-Lb) are values of the line impedance between the node 7B and the position where the switch LSi is provided in the distribution line L100, respectively, and the node 7B and the switch LSj are provided. The value of the line impedance between the positions is shown. Z (Lc) and Z (Li-Lc) are values of the line impedance between the node 7C and the position where the switch LSi is provided in the distribution line L100, respectively, and the node 7C and the switch LSj are provided. The value of the line impedance between the positions is shown. These line impedance values indicate information indicating the positions of the switches LSi and LSj indicated in the system information, information indicating the positions of the nodes 7A to 7C, and the value of the line impedance per unit length of the distribution line L100. It is calculated by the estimation unit 37 based on information, information indicating the length of the distribution line L100, and the like. Further, V2j represents a third negative phase voltage value, I2i represents a first negative phase current value, and I2j represents a second negative phase current value.

<Estimation of source load position>
The estimating unit 37 calculates the second negative phase divided voltage value V2i (A), V2i (B), V2i (C), and the second negative phase divided voltage value calculated without using the equations 2 to 4. A difference value from V2i (also referred to as “reverse phase divided voltage difference value”) is calculated. The estimation unit 37 calculates the second negative phase divided voltage having the smallest difference value from the first negative phase divided voltage value V2i among the second negative phase divided voltage values V2i (A), V2i (B), and V2i (C). The load corresponding to the value is selected as the source load. Thereafter, the estimation unit 37 estimates the position of the load selected as the source load as the position of the source load.

  For example, the difference value between the second negative phase voltage value V2i (A) and the first negative phase voltage value V2i is the difference between the second negative phase voltage value V2i (B) and the first negative phase voltage value V2i. When the difference value and the difference value between the second negative phase divided voltage value V2i (C) and the first negative phase divided voltage value V2i are smaller than each other, the estimation unit 37 selects the load RA as the source load. Thereafter, the estimation unit 37 estimates that the position where the load RA in the distribution line L100 is connected is the position of the source load.

  The estimation unit 37 assumes that the loads RA to RC are connected to the two phases of the distribution line L100, calculates nine negative phase voltage difference values, and then selects the source load. To do. Specifically, the estimation unit 37 considers that the loads RA to RC are connected to the respective sets of the distribution lines L1 and L2, the distribution lines L2 and L3, and the distribution lines L3 and L1, and thus the nine reverse phases. A voltage difference value is calculated. Thereafter, the load corresponding to the minimum difference value is selected from the nine negative phase divided voltage difference values as the source load.

= Notification unit =
The notification unit 38 notifies information about the position of the source load estimated by the estimation unit 37. The notification unit 38 displays, for example, information indicating the position of the source load estimated by the estimation unit 37 on the display unit 34 or outputs the information from an output device (not shown). The notification unit 38 may notify the consumer having the load selected as the source load by the estimation unit 37. For example, when the load R1 is estimated as the source load, the notification unit 38 causes the consumer having the load R1 to cause the load R1 to increase the voltage unbalance rate in the distribution line L100 to be greater than a predetermined value. For example, an e-mail or the like is notified. The consumer who received the notification from the notification unit 38 adjusts the operation of the load R1 based on, for example, the daily load curve of the load R1, the content of the contract with the electric power company, etc. Also good.

=== Operation of Position Estimation Device ===
Hereinafter, with reference to FIG. 1 and FIG. 7, the operation of the position estimation apparatus in the present embodiment will be described. FIG. 7 is a flowchart showing the operation of the position estimation apparatus in the present embodiment.

  A description will be given from the start of execution of the program stored in the storage device 33 and the CPU 31 starting the overall control of the position estimation device 3.

  The position estimation device 3 receives the system information and the measurement signals S1 to S3 (step St11). The position estimation device 3 calculates the voltage imbalance rate of the distribution line L100 based on the information indicated in the measurement signals S1 to S3 (step St12). The position estimation device 3 determines whether or not the voltage imbalance rate calculated in step St12 exceeds a predetermined value (step St13). When it is determined that the voltage imbalance rate exceeds the predetermined value (YES in step St13), the position estimation device 3 detects the source estimation section (step St14). The position estimation device 3 selects a source load from among the loads provided in the detected source estimation section, and estimates the position of the source load (step St15). The position estimation device 3 notifies the information about the position of the source load (step St16), and then ends the operation. In Step St13, when it is determined that the voltage imbalance rate does not exceed the predetermined value (NO in Step St13), the position estimation device 3 ends the operation.

  As described above, the position estimation device 3 includes the estimation unit 37. The estimation unit 37 is indicated by the measurement signal S2 output from the switch LS2 upstream of the loads R1 to R3 connected to any two phases of the three phases of the distribution line L100, for example, in the second switch section. Based on the value of the applied voltage, the value of the negative phase voltage at the position where the switch LS2 is provided is calculated as the first negative phase voltage value. The estimation unit 37 includes a first negative phase current value at a position where the switch LS2 is provided and a second negative phase current value at a position where the switch LS3 downstream of the loads R1 to R3 is provided. Then, based on the value of the line impedance of the distribution line L100 in the second switch section, the value of the negative phase voltage at the position where the switch LS2 is provided is calculated as the second negative phase voltage value. The estimation unit 37 estimates the position of the source load that causes the voltage imbalance in the distribution line L100 based on the first and second reversed-phase voltage values. With these configurations, the position estimation device 3 can estimate the position of the source load without using, for example, the actual measurement value of the voltage at the position where the loads R1 to R3 in the second switch section are connected. Accordingly, it is not necessary to measure the voltage at the position where the loads R1 to R3 are connected to estimate the position of the source load, and even in a distribution system where the number of loads connected to the distribution line L100 is relatively large. Thus, the position of the source load can be reliably estimated.

  The estimation unit 37 estimates the position of the source load based on the difference value between the first negative phase voltage value and the second negative phase voltage value. With this configuration, the position estimation device 3 can estimate the position of the source load based on a relatively simple calculation. Therefore, it is possible to prevent erroneous calculation in the calculation for estimating the position of the source load, and to improve the estimation accuracy of the position of the source load.

  Further, for example, when only the load R1 as the load RA and the load R2 as the load RB are connected to the second switch section, the estimation unit 37 outputs the second negative phase voltage values V2i (A), V2i ( B) Estimate the position of the source load based on the difference value between the second negative phase divided voltage value V2i. Specifically, the estimation unit 37 determines the line impedance value Z (La) between the position where the load RA (FIG. 6) of the distribution line L100 is connected and the position of the switch LSi and the first antiphase component. The product of the current value I2i and the product of the second line impedance value Z (Li-La) between the position where the load RA is connected and the position of the switch LSj and the second negative phase current value I2j Based on the total, the second negative phase divided voltage value V2i (A) when the load RA is assumed to be the source load is calculated. The estimation unit 37 calculates the product of the line impedance value Z (Lb) between the position where the load RB in the distribution line L100 is connected and the position of the switch LSi and the first negative phase current value I2i, Based on the sum of the product of the second line impedance value Z (Li-Lb) between the position where the RB is connected and the position of the switch LSj and the second negative-phase current value I2j, the load RB Is calculated as a second negative phase divided voltage value V2i (B). The estimation unit 37 determines that the first difference value between the second negative phase voltage value V2i (A) and the first negative phase voltage value V2i is the second negative phase voltage value V2i (B) and the first negative phase component. When it is smaller than the second difference value with the voltage value V2i, the position corresponding to the position where the load RA is connected is estimated to be the position of the source load, and the first difference value described above is the second difference value described above. When the value is larger than the value, the position corresponding to the position where the load RB is connected is estimated as the position of the source load. With these configurations, the position estimation device 3 reflects the line impedance value of the distribution line L100, which is considered to be a factor affecting the voltage imbalance of the distribution line L100, and the first and second reversed-phase voltage values. Thus, the position of the source load can be estimated. Therefore, the estimation accuracy of the position of the source load can be improved.

  In addition, in the estimation unit 37, for example, the loads R1 to R3 in the second switch section are connected to the first set of two phases (for example, the distribution lines L1 and L2) of the three sets of two phases in the distribution line L100. Therefore, the second negative phase divided voltage values V2i (A), V2i (B), and V2i (C) are calculated. For example, the estimation unit 37 considers that the loads R1 to R3 in the second switch section are connected to the second set of two phases (for example, the distribution lines L2 and L3) of the three sets of two phases in the distribution line L100. Thus, the second negative phase divided voltage values V2i (A), V2i (B), and V2i (C) are calculated. For example, the estimation unit 37 considers that the loads R1 to R3 in the second switch section are connected to the third set of two phases (for example, the distribution lines L3 and L1) of the three sets of two phases in the distribution line L100. Thus, the second negative phase divided voltage values V2i (A), V2i (B), and V2i (C) are calculated. The estimation unit 37 estimates the position of the source load based on, for example, nine second antiphase voltage values calculated. With these configurations, for example, the position of the source load can be estimated in a state in which the information of the connection destination phase of the loads R1 to R3 in the second switch section is reflected. Therefore, the estimation accuracy of the position of the source load can be improved.

  Moreover, the detection part 36 is based on the measurement result of the switch LS1 thru | or LS3 which measures the electric current value of each of several positions (for example, three places) in the distribution line L100, and the difference value of the electric current value in several positions is judgment electric current. A section between two positions larger than the threshold is detected as a source estimation section. That is, the detection unit 36 detects the source estimation section from the first and second switch sections. The estimation unit 37 calculates the first negative phase voltage value V2i and the second negative phase voltage value in the switch section detected by the detection unit 36 as the generation source estimation period. With these configurations, it is possible to narrow down the loads that are candidates to be selected as the source load. Therefore, the position of the source load can be quickly estimated by reducing the amount of calculation for estimating the position of the source load. Also, by reducing the amount of calculation for estimating the position of the source load, it is possible to prevent erroneous calculation in the calculation and improve the estimation accuracy of the position of the source load. it can.

  Further, the notification unit 38 notifies information about the position of the source load estimated by the estimation unit 37. With this configuration, for example, for a consumer having a load that is estimated (selected) as a source load, the load R1 may be a factor that causes the voltage unbalance rate in the distribution line L100 to be greater than a predetermined value. I can let you know. Therefore, the voltage unbalance rate of the distribution line L100 can be reduced by urging the customer to change the operation plan of the load for causing the voltage unbalance rate based on the notification by the notification unit 38.

  In addition, the said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

  In the above embodiment, the estimation unit 37 has been described for calculating the first and second negative phase current values and the third negative phase voltage value based on the system information and the like. However, the present invention is not limited to this. Absent. For example, the estimation unit 37 calculates the first negative phase current value based on the value of the line current indicated in the measurement signal S2, and the second value based on the value of the line current indicated in the measurement signal S3. A negative phase component current value may be calculated, and a third negative phase component voltage value may be calculated based on the value of the line voltage indicated in the measurement signal S3. In this case, since the measurement results of the switches LS2 and LS3 are reflected on both the first and second negative phase divided voltage values, the estimation accuracy of the position of the source load by the position estimation device 3 is improved. Can be made.

3 Position Estimation Device 36 Detection Unit 37 Estimation Unit 38 Notification Unit 100 Distribution System L1, L2, L3, L100 Distribution Line LS1, LS2, LS3 Switch R1, R2, R3, R4 Load

Claims (7)

Based on the voltage value of the first position upstream of the first and second loads connected to any two phases of the three phases in the section between the first and second positions of the three-phase distribution line, A first arithmetic unit that calculates a value of a negative phase divided voltage at the first position as a first negative phase divided voltage value;
Between the first negative phase current value at the first position, the second negative phase current value at the second position downstream of the first and second loads, and the first and second positions. Based on the value of the line impedance of the three-phase distribution line in the section and the information indicating the position of the node to which the first and second loads are connected , the value of the reverse phase voltage at the first position is set to the second reverse A second arithmetic unit that calculates the phase voltage value;
An estimation device that estimates the position of the causative load that is the cause of the occurrence of voltage imbalance in the three-phase distribution line, based on the first and second negative phase divided voltage values;
A position estimation apparatus comprising: The position according to claim 1, wherein the estimation device estimates the position of the causal load based on a difference value between the first negative phase divided voltage value and the second negative phase divided voltage value. Estimating device. The second arithmetic unit is
The product of the value of the first line impedance as the line impedance between the third position to which the first load is connected in the three-phase distribution line and the first position, and the first reverse-phase current value. , Based on the sum of the product of the value of the second line impedance as the line impedance between the third position and the second position and the second negative phase current value, the first load is A third arithmetic unit that calculates a third negative phase divided voltage value as the second negative phase divided voltage value when it is assumed to be a causal load;
The product of the value of the third line impedance as the line impedance between the fourth position to which the second load is connected in the three-phase distribution line and the first position, and the first reverse-phase current value , Based on the sum of the product of the value of the fourth line impedance as the line impedance between the fourth position and the second position and the second negative phase current value, the second load is A fourth arithmetic unit that calculates a fourth negative phase divided voltage value as the second negative phase divided voltage value when it is assumed to be a causal load;
In the estimation device, the first difference value between the third negative phase voltage value and the first negative phase voltage value based on the calculation result of the third calculation device is based on the calculation result of the fourth calculation device. The position corresponding to the position where the first load is connected is the position of the cause load when the fourth differential voltage value is smaller than the second difference value between the first negative phase voltage value and the first negative phase voltage value. When the first difference value is larger than the second difference value, the position corresponding to the position where the second load is connected is estimated as the position of the cause load. The position estimation apparatus according to claim 1. The second arithmetic unit is
Assuming that the first and second loads are connected to a first set of two phases of the three sets of two phases in the three-phase distribution line, a third negative phase as the second negative phase divided voltage value A third arithmetic unit for calculating a divided voltage value;
Assuming that the first and second loads are connected to a second set of two phases different from the first set of the three sets of two phases, the second negative phase divided voltage value A fourth arithmetic unit for calculating four negative phase divided voltage values;
Assuming that the first and second loads are connected to two phases of a third set different from the first set and the second set of the three sets of two phases, A fifth arithmetic unit that calculates a fifth negative phase divided voltage value as a voltage value,
2. The position estimation according to claim 1, wherein the estimation device estimates a position of the causative load based on the third to fifth negative phase divided voltages as the second negative phase divided voltage value. apparatus. Based on the measurement result of the measuring device that measures the current value at each of the plurality of positions in the three-phase distribution line, each of the two positions at which the difference value between the current values at the plurality of positions is greater than a predetermined value And a detection device that detects the second position,
The first arithmetic device calculates the first negative phase divided voltage value based on the voltage value of the first position detected by the detection device,
The second arithmetic device is based on a first negative phase current value at the first position detected by the detection device and a second negative phase current value at the second position detected by the detection device. The position estimation device according to claim 1, wherein the second negative phase divided voltage value is calculated. The position estimation device according to claim 1, further comprising: a notification device that notifies information about the position of the causal load estimated by the estimation device. Based on the voltage value of the first position upstream of the first and second loads connected to any two phases of the three phases in the section between the first and second positions of the three-phase distribution line, A first step of calculating a negative phase divided voltage value at the first position as a first negative phase divided voltage value;
Between the first negative phase current value at the first position, the second negative phase current value at the second position downstream of the first and second loads, and the first and second positions. Based on the value of the line impedance of the three-phase distribution line in the section and the information indicating the position of the node to which the first and second loads are connected , the negative phase voltage value of the first position is determined as the second negative phase. A second step of calculating as a divided voltage value;
A third step of estimating a position of a causative load that is a cause of occurrence of voltage imbalance in the three-phase distribution line based on the first and second reverse-phase divided voltage values. Estimation method.

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