JP2014233154A - Distribution system monitoring system and distribution system monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to inexpensively and accurately monitor voltage of a high-voltage distribution line by using measurement information from a smart meter on the user side.SOLUTION: A distribution system monitoring system according to an embodiment comprises: a plurality of smart meters for measuring electric energy of users; a measurement apparatus for measuring electric energy and voltage of the secondary side of a distribution substation; collection means for collecting the electric energy of the users measured by the smart meters, and the electric energy and voltage of the secondary side of the distribution substation measured by the measurement apparatus on the secondary side of the distribution substation; high-voltage distribution line voltage estimation means for estimating voltage of a high-voltage distribution line by performing power flow calculation on the basis of impedance of a high-voltage distribution line from the distribution substation to an observation point, which is an installation location of a pole transformer, a total value of electric energy of the users at the observation point, and electric energy and voltage on the secondary side of the distribution substation.

Description

  Embodiments described herein relate generally to a distribution system monitoring system and a distribution system monitoring apparatus that monitor the state of a distribution system.

  Generally, a distribution system is composed of a plurality of high-voltage distribution lines drawn from a distribution substation, and supplies power to consumers by dropping the voltage from the high-voltage distribution line to the low-voltage distribution line via a pole transformer. . Multiple customers are connected to the pole transformer. Conventionally, in order to ensure the reliability of the distribution system, maintain appropriate voltage, maintain power quality, and smoothly operate the system, system monitoring is performed to grasp the system status such as substation voltage and feeder current.

  However, in recent years, the introduction of renewable energy into the distribution system has progressed, and the maintenance and management of the operation targets of the distribution system have become complicated. In particular, the introduction of in-house power generators such as solar power generation to the distribution system is progressing, and the system voltage rises due to reverse power flow from the distributed power supply, and the voltage may deviate from the appropriate range. .

  Therefore, Non-Patent Document 1 discusses a method of estimating a voltage distribution of a distribution system by installing a switch with a sensor on a high-voltage side distribution line.

  In the future, if smart meters are installed at each consumer, it may be used to monitor the distribution system instead of installing expensive switches with sensors. For example, Patent Literature 1 and Patent Literature 2 propose a method for determining a distribution system voltage based on meter data.

JP 2012-182990 A Special table 2012-515521 gazette JP 09-46935 A

Report of the Central Research Institute of Electric Power Industry Report No. R04011 “Voltage Estimation Method for Distribution System Based on Sensor Switch Information” Toshihiko Komukai, Shoichi Irokawa, Masakazu Kato, “Lecture on Power System Engineering at Semester University”, Maruzen Co., Ltd., September 1999, pp. 35-44 Central Research Laboratory Report: 102 “Development of Power System State Estimation Method” Electrical Engineering Handbook 6th edition, edition 30 Power distribution, p.1378 Table 37

  However, these proposals determine the voltage on the primary side using the synchronized phasor amount of the voltage and current on the secondary side of the pole transformer. In order to measure the amount of synchronized phasors, it is necessary to add a high-accuracy synchronization signal, GPS (Global Positioning System), etc., and high-speed sampling measurement, which is more expensive than a general smart meter.

  On the other hand, general smart meters whose main purpose is to automate meter reading work have low time resolution and time synchronism due to communication infrastructure limitations. Furthermore, since the measurement data is measured at the customer end on the low voltage side, there is a problem that a difference occurs between the state of the high voltage distribution line to be monitored due to the loss of the lead-in line, the low voltage distribution line, and the pole transformer. is there.

  An object of the present embodiment is to provide a distribution system monitoring system and a distribution system monitoring apparatus that can accurately monitor the voltage of a high-voltage distribution line at low cost by using measurement information of a smart meter on the customer side.

  The distribution system monitoring system according to the present embodiment is a system for monitoring a distribution system that supplies electric power to a plurality of consumers from a high-voltage distribution line drawn out from a distribution substation via a pole transformer, A plurality of smart meters that measure the amount of power of the consumer, a measuring device that measures the amount of power and voltage on the secondary side of the distribution substation, the amount of power of the consumer that is measured by the smart meter, Collecting means for collecting the electric energy and voltage on the secondary side of the distribution substation measured by the secondary side measuring instrument of the distribution substation, and the distribution point using the installation location of the pole transformer as an observation point Power flow based on the impedance of the high-voltage distribution line from the power substation to the observation point, the total amount of power of the customer at the observation point, and the power and voltage on the secondary side of the distribution substation Calculate the voltage of the high-voltage distribution line Those comprising a high-voltage distribution line voltage estimating means for estimating.

The figure which shows the power distribution system monitoring system which concerns on 1st Embodiment. The figure which shows an example of the power distribution system which concerns on 1st Embodiment. The flowchart which shows the process sequence of the power distribution system monitoring apparatus which concerns on 1st Embodiment. The figure which shows an example of the power distribution system which concerns on 2nd Embodiment. The flowchart which shows the process sequence of the power distribution system monitoring apparatus which concerns on 2nd Embodiment. The flowchart which shows the process sequence of the power distribution system monitoring apparatus which concerns on 3rd Embodiment. The figure which shows an example of the power distribution system which concerns on 4th Embodiment. The flowchart which shows the process sequence of the power distribution system monitoring apparatus which concerns on 4th Embodiment.

  Hereinafter, a distribution system monitoring system and a distribution system monitoring apparatus according to the present embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a power distribution system monitoring system according to the first embodiment.
The distribution system monitoring system shown in FIG. 1 distributes power from a plurality of high-voltage distribution lines 3 drawn out from a distribution substation 2 to a plurality of low-voltage customers 5 via pole transformers 4. Monitor system status. The distribution system monitoring system monitors the state of the measuring device 7 that measures the amount of power on the secondary side of the distribution substation 2, the smart meter 6 that measures the amount of power of each consumer 5, and the high-voltage distribution line 3. A distribution system monitoring device 1;

  The distribution system monitoring device 1 collects the measurement information of the smart meter 6 and the substation measuring instrument 7 via the communication infrastructure 8, the distribution system facility information including the connection information and impedance of the high-voltage distribution line, and the collection Storage unit 102 that stores measurement information collected by unit 101, and high-voltage distribution line voltage estimation unit that estimates voltages V1, V2, V3,... (High-voltage distribution line voltage Vi) at each observation point i of high-voltage distribution line 3 103 and a display unit 104 for displaying the estimation result of the high-voltage distribution line voltage.

  FIG. 2 shows an example of the power distribution system according to the first embodiment. The electric power transmitted from the host system is transformed into a voltage of 6.6 kV at the distribution substation 2 and distributed to the load via the high-voltage distribution line 3 and the pole transformer 4. FIG. 2 shows a smart meter 6 installed for each consumer as a load group below the pole transformer 4. The measuring instrument 7 collects the power P and voltage V0 on the 6.6 kV side of the distribution substation for each control period. Impedances Z1, Z2, and Z3 from the distribution substation 2 to the voltage observation points V1, V2, and V3 of the high-voltage distribution line are held in the storage unit 102 in advance. As shown in FIG. 2, each smart meter 6 measures the electric energy Pm11, Pm12, Pm13 and power factor Pf1 for every consumer for every predetermined time.

The operation of the distribution system monitoring apparatus 1 according to the first embodiment will be described. FIG. 3 is a flowchart illustrating an example of a processing procedure of the power distribution system monitoring apparatus according to the first embodiment.
In the distribution system monitoring apparatus 1 configured as shown in FIG. 1, the collection unit 101 uses the power amount and power factor measured by the smart meter 6 of the consumer 5 and the power measured by the measuring instrument 7 of the distribution substation 2. The quantity and voltage are collected via the communication infrastructure 8 (step S101). Next, the high voltage distribution line voltage estimation unit 103 stores the connection information and impedance of the high voltage distribution line in the storage unit 102, the power amount and voltage of the distribution substation 2 collected in step S101, and the power amount and power of each consumer. The high-voltage side distribution line voltage Vi is estimated using the rate (step S201).

  In addition, when the measurement data on the secondary side of the distribution substation 2 and the measurement data of the smart meter 6 are the integrated electric energy [Wh] for a predetermined time, the power is converted into the electric power [W] averaged over the predetermined time. That's fine. The installation location of the pole transformer 4 is a voltage observation point i, and the power collected by each smart meter 6 is used in total for each pole transformer (for example, in FIG. 2, P1 = Pm11 + Pm12 + Pm13). When the power factor or reactive power cannot be collected from the smart meter 6, the reactive power is calculated using the assumed value of the power factor. The power Pi and Qi of this voltage observation point are given as PQ designation, the power P0 and voltage V0 of the distribution substation 2 are given as PV designation, and the voltage of each voltage observation point Vi can be solved by power flow calculation (for example, Non-patent document 2).

  Furthermore, as an estimation method that takes into account uncertain factors such as time resolution of the measurement data of the smart meter 6, time asynchronousness, and low-voltage distribution line loss, state estimation conventionally used in a backbone system can be applied (for example, non-patent literature) 3, see Patent Document 3).

When the state variable x of the power distribution system is defined as the voltage magnitude and the phase angle at all observation points, it is represented by the vector of Expression (1).

When the power P0, the voltage V0 of the distribution substation 2 and the power collected by the smart meter 6 totaled for each pole transformer are assumed to be an observation variable z, it can be expressed by a vector of equation (2).

The relationship between the state variable x and the observation variable z is expressed by equation (3), where v is the error associated with the observation.

Assuming that the statistical property of the error vector v is white noise, the optimum estimated value of the state variable x can be solved by the weighted least square method as x that minimizes the equation (4).

  The display unit 104 displays the high-voltage distribution line voltage Vi estimated as described above (step S301).

  As described above, according to the first embodiment, even if an expensive high-precision sensor is not newly installed on the high-voltage distribution line, the voltage distribution of the distribution system can be obtained by utilizing the measurement information of each customer's smart meter. Can be used for voltage management of the entire distribution system.

(Second Embodiment)
A power distribution system monitoring system according to the second embodiment will be described with reference to FIGS. 4 and 5. Since the system configuration of the second embodiment is the same as that of the first embodiment, FIG. 1 is used. 4 and 5, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 4 shows an example of a power distribution system according to the second embodiment. In 2nd Embodiment, as shown in FIG. 4, each smart meter 6 measures electric energy Pm11, Pm12, Pm13, voltage Vm1, and power factor Pf1 for every consumer for every predetermined time. In addition, the storage unit 102 stores low-voltage-side facility information (post transformer impedance, low-voltage distribution line impedance, and lead-in line impedance) in advance. In the calculation of the high-voltage distribution line voltage Vi in the first embodiment, when the low-voltage distribution line loss Ploss is further considered, it can be expressed as P1 = Pm11 + Pm12 + Pm13 + Ploss1. Therefore, in the second embodiment, the voltage drop VL due to the low-voltage distribution line loss Ploss is obtained using the measurement data of the smart meter 6 and the low-voltage side equipment information, and the low-voltage side voltage drop from the high-voltage distribution line 3 to the consumer. Is used to correct the high-voltage distribution line voltage Vi.

  FIG. 5 is a flowchart illustrating an example of a processing procedure of the power distribution system monitoring apparatus according to the second embodiment. In the distribution system monitoring apparatus 1 configured as shown in FIG. 1, the collection unit 101 includes the power amount, voltage, and power factor measured by the smart meter 6 of the consumer 5 and the measuring device 7 of the distribution substation 2. The measured electric energy and voltage are collected via the communication infrastructure 8 (step S101).

  Similarly to step S201, the high-voltage distribution line voltage estimation unit 103 is configured to connect the high-voltage distribution line connection information and impedance in the storage unit 102, the power amount and voltage of the distribution substation 2 collected in step S101, and the power of each customer. The high-voltage distribution line voltage Vi is estimated using the quantity and the power factor (step S202).

Next, the low-voltage side from the high-voltage distribution line to the consumer using the power amount and voltage and low-voltage equipment information (post transformer impedance, low-voltage distribution line impedance, lead-in line impedance) collected in step S101. A voltage Vi ′ based on the voltage drop is calculated (step S203). When the low-pressure side equipment information is unknown, it can be calculated using general data. As an example of distribution of a general voltage drop, there are a pole transformer 2%, a low voltage distribution line 3%, and a lead-in line 3% (see Non-Patent Document 4). Alternatively, if it is possible to obtain the low-voltage side impedance Z ′, the voltage drop VL due to the low-voltage distribution line loss is obtained from the equation (5).

  An assumed value may be used when the power factor cannot be collected from the smart meter 6. When the current I can be collected from the smart meter 6, the measurement data of the smart meter 6 is used.

Therefore, the voltage Vi ′ based on the low-voltage side voltage drop from the high-voltage side distribution line 3 to the consumer is expressed by equation (6).

Then, the time resolution and time asynchronousness of the measurement data of the smart meter 6 are minimized so that the difference between the high-voltage side distribution line voltage Vi obtained in step S202 and the voltage Vi ′ based on the low-voltage side voltage drop obtained in step S203 is minimized. Then, correction is performed in consideration of uncertain factors such as low-voltage distribution line loss (step S401). For example, the power flow equation, the power factor of each consumer, and contract capacity if available, using the power flow equation (7) as a constraint, the low-voltage side equipment information (pole transformer impedance, low-voltage distribution line) Impedance, lead-in line impedance) or low-voltage side impedance Z ′ is corrected, and voltage drop VL due to low-voltage distribution line loss Ploss and low-voltage distribution line loss is corrected.

  As described above, according to the second embodiment, the voltage distribution of the distribution system can be obtained using the measurement information of each customer's smart meter without newly installing an expensive high-precision sensor on the high-voltage distribution line. Can be used for voltage management of the entire distribution system. In many cases, it is difficult to collect low-voltage distribution line information with sufficient accuracy that can determine the voltage drop VL due to the low-voltage distribution line loss Ploss and the low-voltage distribution line loss. The accuracy can be improved by correcting uncertain elements such as time resolution, asynchronous time, and low-voltage distribution line loss.

(Third embodiment)
A distribution system monitoring system according to the third embodiment will be described with reference to FIG. In the third embodiment, since the load actually changes every moment, the correction for the load fluctuation is considered. In addition, since the system configuration | structure and power distribution system of 3rd Embodiment are the same as that of 2nd Embodiment, it shall use FIG.1 and FIG.4. Moreover, in FIG. 6, the same code | symbol is attached | subjected to the part same as 2nd Embodiment, and the overlapping description is abbreviate | omitted.

FIG. 6 is a flowchart illustrating an example of a processing procedure of the distribution system monitoring apparatus according to the third embodiment. Similar to the second embodiment, the processing from step S101 to step S202 and step S203 is performed for a predetermined plurality of time sections, and the high voltage distribution line voltage estimated value Vi and the low voltage side voltage drop from the high voltage distribution line to the consumer And a voltage Vi ′ based on the above. Then, a correction amount that minimizes the difference between Vi and Vi ′ for a plurality of time sections is obtained (step S402). For example, adjust the low-voltage distribution line loss Ploss by adjusting the power flow equation, the power factor of each customer, and contract capacity if available, so that Eq. (8) is minimized. To do.

  As described above, according to the third embodiment, even if an expensive high-precision sensor is not newly installed, the measurement information of each customer's smart meter at a plurality of time sections including load fluctuations is utilized to A voltage distribution can be obtained and used for voltage management of the entire distribution system. In many cases, it is difficult to collect low-voltage distribution line information with sufficient accuracy that can determine the voltage drop VL due to the low-voltage distribution line loss Ploss and the low-voltage distribution line loss. The accuracy can be improved by correcting uncertain elements such as time resolution, time asynchronization, low-voltage distribution line loss, and load fluctuation.

(Fourth embodiment)
A distribution system monitoring system according to the fourth embodiment will be described with reference to FIGS. 7 and 8. In 4th Embodiment, when there exists unmeasured electric power which is not measured with a smart meter by theft etc., the point which has the unmeasured electric power is estimated. Since the system configuration of the fourth embodiment is the same as that of the second embodiment, FIG. 1 is used. Moreover, in FIG.7 and FIG.8, the same code | symbol is attached | subjected to the part same as 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 7 shows an example of a power distribution system according to the fourth embodiment. In the fourth embodiment, as shown in FIG. 7, each smart meter 6 measures the power amounts Pm11, Pm12, Pm13, voltage Vm1, and power factor Pf1 for each consumer every predetermined time. In the calculation of the high-voltage distribution line voltage Vi in the second embodiment, when the unmeasured power Ptheft is further considered, it can be expressed as P1 = Pm11 + Pm12 + Pm13 + Ploss1 + Ptheft. Therefore, in the fourth embodiment, the unmeasured power Ptheft is assigned to each observation point i to obtain the high voltage distribution line voltage estimated value Vi, and the correction amount that minimizes the difference from the voltage Vi ′ based on the low voltage drop is obtained. Thus, a point with unmeasured power is estimated.

  FIG. 8 is a flowchart illustrating an example of a processing procedure of the power distribution system monitoring apparatus according to the fourth embodiment. As in the second embodiment, the collection unit 101 uses the power amount, voltage, and power factor measured by the smart meter 6 of the consumer 5 and the power amount and voltage measured by the measuring device 7 of the distribution substation 2. Collect via the communication infrastructure 8 (step S101).

Next, the high voltage distribution line voltage estimation unit 103 subtracts the total value of the electric energy of all the consumer smart meters 6 and the total distribution line loss from the distribution substation power P0 as shown in the equation (9), and is set in advance. Compare with threshold. If Ptheft in equation (9) is greater than the threshold, it is determined that there is unmeasured power such as stealing (step S501).

  When there is unmeasured data, the unmeasured power Ptheft of the equation (9) is assigned to an arbitrary observation point i (step S502), and power flow calculation is performed to estimate the high-voltage distribution line voltage estimated value Vi (step S202). Then, similarly to the second embodiment, the voltage Vi ′ based on the low voltage drop from the high voltage distribution line 3 to the consumer is obtained, and the correction amount that minimizes the difference between Vi and Vi ′ is obtained (step S401). The correction amount can be obtained by the method shown in the second embodiment. When the allocation of the unmeasured power Ptheft to all nodes is completed (step S503), the allocation point with the smallest correction amount is estimated as a point with unmeasured power (step S504).

  As described above, according to the fourth embodiment, it is possible to obtain the voltage distribution of the distribution system by utilizing the measurement information of each customer's smart meter without newly installing an expensive high-precision sensor. It can be used for voltage management of the entire distribution system. In addition, when there is a power theft, it is possible to estimate a power theft point.

  Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Distribution system monitoring apparatus, 2 ... Distribution substation, 3 ... High voltage distribution line, 4 ... Pole transformer, 5 ... Consumer, 6 ... Smart meter, 7 ... Distribution substation measuring instrument, 8 ... Communication infrastructure DESCRIPTION OF SYMBOLS 101 ... Collecting part 102 ... Memory | storage part 103 ... High voltage distribution line voltage estimation part 104 ... Display part.

Claims (12)

A system for monitoring a distribution system that supplies power from a high-voltage distribution line drawn from a distribution substation to a plurality of consumers via a transformer,
A plurality of smart meters for measuring the electric energy of the consumer;
A measuring instrument for measuring the amount of electricity on the secondary side of the distribution substation;
Collecting means for collecting the amount of electric power of the consumer measured by the smart meter and the amount of electricity on the secondary side of the distribution substation measured by the secondary side measuring instrument of the distribution substation;
With the installation location of the transformer as an observation point, the impedance of the high-voltage distribution line from the distribution substation to the observation point, the total value of the electric energy of the consumer at the observation point, and the secondary of the distribution substation A distribution system monitoring system comprising: a high voltage distribution line voltage estimating means for calculating a power flow based on the amount of electricity on the side and estimating a voltage of the high voltage distribution line.   The high-voltage distribution line voltage estimation means uses the voltage magnitude and phase angle at the observation point as state variables, and the total value of the electric energy of the consumer at the observation point and the electric power on the secondary side of the distribution substation. The distribution system monitoring system according to claim 1, further comprising: solving the optimum value of the state variable by state estimation assuming that the quantity is an observation variable and an error associated with the observation is white noise. The collecting means further collects the consumer voltage measured by the smart meter,
The voltage drop from the observation point to the consumer is calculated from the impedance of the low-voltage distribution line from the observation point to the consumer and the total amount of power of the consumer at the observation point, and the voltage drop and the Low voltage side voltage drop calculating means for calculating a voltage based on the voltage of the consumer;
The impedance of the low-voltage distribution line at the observation point or the power of the consumer so as to minimize the difference between the voltage estimated by the high-voltage distribution line voltage estimation means and the voltage calculated by the low-voltage side voltage drop calculation means The distribution system monitoring system according to claim 1, further comprising correction means for correcting the total value of the quantities. The collection means, for a plurality of times, collects the amount of electricity of the consumer measured by the smart meter and the amount of electricity on the secondary side of the distribution substation measured by the measuring instrument,
The correction unit is configured to minimize the integrated value of the difference between the voltage estimated by the high-voltage distribution line voltage estimation unit and the voltage calculated by the low-voltage side voltage drop calculation unit at a plurality of times. The distribution system monitoring system according to claim 3, wherein an impedance of the low-voltage distribution line or a total value of electric power of the consumer is corrected. The high-voltage distribution line voltage estimation means subtracts a total value of the customer's power amount of the entire distribution substation and a distribution line loss of the entire distribution system from the secondary side energy amount of the distribution substation. If the measured value is greater than the threshold value,
Unmeasured power amount point estimation that assigns the unmeasured power amount to a point that minimizes the difference between the voltage estimated by the high-voltage distribution line voltage estimation unit and the voltage calculated by the low-voltage side voltage drop calculation unit The distribution system monitoring system according to claim 3, further comprising means. A system for monitoring a distribution system that supplies power from a high-voltage distribution line drawn from a distribution substation to a plurality of consumers via a transformer,
A plurality of smart meters for measuring the amount of electricity of the consumer;
A collecting means for collecting the amount of electricity of the consumer measured by the smart meter;
From the observation point to the consumer as the observation point of the installation location of the transformer equipment, from the impedance of the low-voltage distribution line from the observation point to the consumer and the total value of the power of the consumer at the observation point A power distribution system monitoring system comprising: a low voltage side voltage drop calculating means for calculating a voltage drop and calculating a voltage based on the voltage drop and the voltage of the consumer. A device for monitoring a distribution system that supplies power to a plurality of consumers via a transformer from a high-voltage distribution line drawn from a distribution substation,
Collecting means for collecting the amount of electric power of the consumer measured by the smart meter for each consumer and the amount of electricity on the secondary side of the distribution substation measured by the secondary side measuring instrument of the distribution substation When,
With the installation location of the transformer as an observation point, the impedance of the high-voltage distribution line from the distribution substation to the observation point, the total value of the electric energy of the consumer at the observation point, and the secondary of the distribution substation A distribution system monitoring apparatus comprising: high-voltage distribution line voltage estimation means for performing power flow calculation based on the amount of electricity on the side and estimating a voltage of the high-voltage distribution line.   The high-voltage distribution line voltage estimation means uses the voltage magnitude and phase angle at the observation point as state variables, and the total value of the electric energy of the consumer at the observation point and the electric power on the secondary side of the distribution substation. The distribution system monitoring apparatus according to claim 7, further comprising: solving the optimum value of the state variable by state estimation assuming that the quantity is an observation variable and an error associated with the observation is white noise. The smart meter further measures the voltage of the consumer,
The collecting means collects the voltage of the consumer measured by the smart meter,
Low voltage side voltage drop calculating means for calculating the voltage of the high voltage distribution line based on the voltage drop from the transformer to the consumer;
The impedance of the low-voltage distribution line at the observation point or the power of the consumer so as to minimize the difference between the voltage estimated by the high-voltage distribution line voltage estimation means and the voltage calculated by the low-voltage side voltage drop calculation means The distribution system monitoring apparatus according to claim 7, further comprising a correction unit that corrects the total value of the quantities. The collection means, for a plurality of times, collects the amount of electricity of the consumer measured by the smart meter and the amount of electricity on the secondary side of the distribution substation measured by the measuring instrument,
The correction unit is configured to reduce the difference between the voltage estimated by the high-voltage distribution line voltage estimation unit and the voltage calculated by the low-voltage side voltage drop calculation unit at a plurality of times. The distribution system monitoring apparatus according to claim 9, wherein an impedance of a distribution line or a total value of electric power of the customer is corrected. The high-voltage distribution line voltage estimation means subtracts a total value of the customer's power amount of the entire distribution substation and a distribution line loss of the entire distribution system from the secondary side energy amount of the distribution substation. If the measured value is greater than the threshold value,
Unmeasured power amount point estimation that assigns the unmeasured power amount to a point that minimizes the difference between the voltage estimated by the high-voltage distribution line voltage estimation unit and the voltage calculated by the low-voltage side voltage drop calculation unit The distribution system monitoring apparatus according to claim 9, further comprising means. A device for monitoring a distribution system that supplies power to a plurality of consumers via a transformer from a high-voltage distribution line drawn from a distribution substation,
A collecting means for collecting the amount of electricity of the consumer measured by the smart meter on the consumer side;
From the observation point to the consumer as the observation point of the installation location of the transformer equipment, from the impedance of the low-voltage distribution line from the observation point to the consumer and the total value of the power of the consumer at the observation point A power distribution system monitoring apparatus comprising: a low voltage side voltage drop calculating means for calculating a voltage drop and calculating a voltage based on the voltage drop and the voltage of the consumer.

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