JP2011217465A - Detection system of influence to three-phase distribution line of photovoltaic power generation equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an influence to a three-part distribution line caused by photovoltaic power generation equipment installed at a single-phase low-voltage distribution line of a general home and an individual consumer on assumption that the photovoltaic power generation equipment may rapidly be diffused to the general home and the individual consumer in future.SOLUTION: This detection system for influence to the three-phase distribution line of the photovoltaic power generation equipment comprises an each-phase current measurement device 5 which detects a current of each phase of a power distribution line at the three-phase side of a distribution line transformer 2 which converts three phases to a single phase, and an estimation part 11 which discriminates trends of a magnitude and a change of the each-phase current at each prescribed time on the basis of the each-phase current measured by the each-phase current measurement device and estimates that the imbalance of the each-phase current of the distribution line at the three-phase side is caused by the photovoltaic power generation equipment installed at the single-phase side low-voltage distribution line of the distribution line transformer.

Description

  The present invention relates to a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line, and more particularly to a system for detecting an influence on a three-phase distribution line due to an increase in the number of photovoltaic power generation facilities connected to a single-phase low-voltage distribution line. It can contribute to planning, operation, control, etc. in the system.

  Systems have been developed that discriminate between interconnection and disconnection of a distributed power source such as a micro gas turbine or wind power generation. (See, for example, Japanese Patent Application Laid-Open No. 2007-110829)

  By the way, if it is assumed that solar power generation equipment will rapidly spread to households and small-lot customers in the future, measures to detect the influence on the distribution line and countermeasures to the influence on the distribution line should be examined in advance. It is preferable to keep it.

Japanese Patent Laying-Open No. 2007-110829 (FIG. 5 and description thereof)

  If the number of photovoltaic power generation equipment installed in households and small consumers will increase rapidly in the future, the number of solar power generation equipment installed in the households and small consumers, capacity, connection points to distribution lines, etc. will be grasped as numerical values. Although it is possible, the photovoltaic power generation equipment installed in homes and small consumers will be installed in single-phase low-voltage distribution lines, so it may have an impact on three-phase distribution lines. No policy has been proposed yet.

  The present invention assumes that solar power generation equipment will rapidly spread to households and small consumers in the future, and that the three-phase distribution lines by solar power generation equipment installed in single-phase low-voltage distribution lines of homes and small consumers The purpose is to detect the influence.

  The system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line according to the present invention is a phase current measurement for detecting a current of each phase of a distribution line on the three-phase side of a distribution line transformer that converts three phases into a single phase. Device, and the phase current measured by each phase current measuring device, the magnitude and change tendency of each phase current every predetermined time are determined, and the current imbalance of each phase of the three-phase distribution line is This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line, which includes an estimation unit that estimates that it is caused by the photovoltaic power generation facility installed on the single-phase low-voltage distribution line of the distribution line transformer.

  The present invention relates to each phase current measuring device that detects a current of each phase of a distribution line on the three-phase side of a distribution line transformer that converts three phases into a single phase, and each phase current measured by each phase current measuring device. The current of each phase of the three-phase distribution line is unbalanced and the current of each phase of the three-phase distribution line is unbalanced on the single-phase low-voltage distribution line of the distribution line transformer. Because it is a system for detecting the impact on the three-phase distribution line of the photovoltaic power generation facility with an estimation unit that estimates that it is caused by the photovoltaic power generation facility, the solar system installed on the single-phase low-voltage distribution line of homes and small consumers There is an effect that it becomes possible to detect the influence of the photovoltaic power generation facility on the three-phase distribution line.

It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the system configuration | structure of the influence detection system to the three-phase distribution line of the photovoltaic power generation equipment connected to a single phase low voltage distribution line. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the connection relation of the distribution line transformer which converts a three phase into a single phase, and photovoltaic power generation equipment. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the time change of the a phase current data of the three-phase distribution line in FIG. 2, and its long-term variation data and short-term variation data. It is a figure which shows Embodiment 1 of this invention, and is a figure which compares and illustrates the time change of the short-term fluctuation data of each phase current of the a phase of the three-phase distribution line in FIG. 2, b phase, and c phase. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example which plotted the value for every minute of each phase short-term fluctuation data in FIG. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows the other example of the system configuration | structure of the influence detection system to the three-phase distribution line of the photovoltaic power generation equipment connected to a single phase low voltage distribution line.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS.

  In FIG. 1 showing an example of the system configuration of an influence detection system for a three-phase distribution line of a photovoltaic power generation facility connected to a single-phase low-voltage distribution line, the power system includes, for example, a large number of three-phase high-voltage distribution lines 1 to 1n of 6600V. Each of the three-phase high-voltage distribution lines 1 to 1n has a number of distribution line transformers 2 with the three-phase high-voltage distribution lines as the primary side, and the secondary side of the distribution line transformer 2 has 110V / 220V There is a single-phase three-wire low-voltage distribution line, and the low-voltage distribution customers 3, 3,... However, as a distributed power source of the power system, it tends to spread rapidly in the future, and the number of photovoltaic power generators connected to a single-phase low-voltage distribution line tends to increase rapidly.

  The three-phase high-voltage distribution line 1 is appropriately divided by a well-known division switch SW, and each phase current measuring device 5 for measuring the current value of each phase of the three-phase high-voltage distribution line 1 is provided in this division switch. The output of each phase current measuring device 5 is transmitted from the transmitter 6 to the monitoring terminal (personal computer, server, monitoring device, monitoring device, etc.) via the communication network 7.

  The monitoring terminal 8 includes a measurement data reception / storage unit 9 that receives and stores each phase current value data transmitted from the transmitter 6, and each phase current change that separates each phase current value into a long-term fluctuation part and a short-term fluctuation part. The detection unit 10, the unbalance factor estimation unit 11 that analyzes and estimates the bias of the connected phase from the long-term variation data and the short-term variation data of each phase current value, and the analysis result in the unbalance factor estimation unit 11 is a human or other device The connection phase estimation result presenting unit 12 for providing information to is provided. Further, the measurement data examination / storage unit 9, each phase current change detection unit 10, the unbalance factor estimation unit 11, and the connected phase estimation result presentation unit 12 estimate the unbalance factor that estimates the photovoltaic power generation facility as an unbalance factor. It is a partial device that is a part of a component of the processing device or the unbalance factor estimation processing system.

  In addition, in FIG. 1, other than the three-phase high-voltage distribution line 1, other three-phase high-voltage distribution lines also include a large number of the distribution line transformer, the general household, the small consumer, the section switch, and each phase current detection device. The transmitter is connected, but is not shown for the sake of simplicity. In the following description, the three-phase high-voltage distribution line 1 will be described as a representative.

For example, as shown in FIG. 2, the distribution line transformer 2 has a primary-side three-phase high-voltage distribution line of 6600V, a primary winding a-phase, and a secondary winding electromagnetically coupled to a b-phase winding. Both ends are connected to a single-phase low-voltage distribution line, 110V ordinary household photovoltaic power generation equipment 4 is an AC output end is a 110V single-phase low-voltage distribution line, 220V small-scale consumer photovoltaic power generation equipment is the AC output Each end is connected to a 110V single-phase low-voltage distribution line.

  The photovoltaic power generation facility 4 converts direct current into direct current / alternating current with an inverter, supplies the alternating current output to a load of ordinary households and small consumers, and supplies surplus power to the single-phase low-voltage distribution line. When a single-phase low-voltage distribution line fails due to an accident or the like, supply of the surplus power to the single-phase low-voltage distribution line is stopped, and supply of the surplus power to the single-phase low-voltage distribution line is resumed. It is performed after a predetermined time from the start of energization from the commercial power source, and from the start of energization from the commercial power source of the single-phase low-voltage distribution line to the start of supply of the surplus power to the single-phase low-voltage distribution line, Power is supplied to each load exclusively from a commercial power source, and during this time, an extra amount of power corresponding to the amount of surplus power supplied to the single-phase low-voltage distribution line is supplied from the commercial power source side.

  In addition, when the distribution line is interrupted due to an accident or the like, depending on the type of load, there is a load that stops until it is restarted. However, when the photovoltaic power generation facility 4 starts supplying the surplus power to the single-phase low-voltage distribution line, the surplus power amount of the photovoltaic power generation facility 4 is reduced to the load. Oversupply.

  Further, the output of the solar power generation equipment 4 is constant in the case of rainy weather, cloudy weather, and clear weather, but in the weather other than rainy weather, cloudy weather, and clear weather, that is, in a sunny state where clouds exist, Since the sunlight incident on the solar light receiving panel is intermittently blocked by the clouds, the output of the solar power generation equipment 4 varies.

When the output of the solar power generation facility 4 fluctuates, the surplus power supply amount of the solar power generation facility 4 supplied to the single-phase low-voltage distribution line also varies in the same manner.
Due to the fluctuation of the supply amount of surplus power, the a-phase current Ia and the b-phase current Ib of the three-phase high-voltage distribution line on the primary side of the distribution line transformer 2 similarly fluctuate, and the c-phase current Ic has a small influence. The amount of fluctuation is small.

The a-phase current Ia and the b-phase current Ib of the three-phase high-voltage distribution line on the primary side of the distribution line transformer 2 fluctuate in the same manner, and the c-phase current Ic has a small influence and a small fluctuation amount. This is because the secondary winding to which the single-phase low-voltage distribution line connected to is connected to the a-phase-b winding of the three-phase primary winding is electromagnetically coupled. If the secondary winding to which the single-phase low-voltage distribution line to be connected is electromagnetically coupled to the a-phase-c phase winding of the three-phase primary winding, the sun supplied to the single-phase low-voltage distribution line The a-phase current Ia and the c-phase current Ic of the three-phase high-voltage distribution line on the primary side of the distribution line transformer 2 fluctuate in the same manner due to fluctuations in the surplus power supply amount of the photovoltaic power generation facility 4, and the b-phase current Ib is affected. Small and less variable. Similarly, if the secondary winding to which the single-phase low-voltage distribution line to which the photovoltaic power generation equipment 4 is connected is electromagnetically coupled to the b-phase to c-phase windings of the three-phase primary winding, The b-phase current Ib and the c-phase current Ic of the three-phase high-voltage distribution line on the primary side of the distribution line transformer 2 similarly fluctuate due to fluctuations in the amount of surplus power supplied from the photovoltaic power generation equipment 4 supplied to the phase low-voltage distribution line. However, the a-phase current Ia has a small influence and a small fluctuation amount.
In other words, an unbalanced current flows in the three phases of the three-phase high-voltage distribution line due to the influence of the photovoltaic power generation equipment 4 connected to the single-phase low-voltage distribution line.

When the amount of sunlight incident on the solar light receiving panel of the solar power generation facility 4 is large, the amount of power generated by the solar power generation facility 4 increases, and the surplus power to the single-phase low-voltage distribution line In addition, if the number of installed solar power generation facilities 4 increases rapidly, the amount of surplus power supplied to the single-phase low-voltage distribution line will increase accordingly.
In other words, the three-phase unbalanced current of the three-phase high-voltage distribution line is increased.

If the number of installed photovoltaic power generation facilities 4 increases rapidly, if the amount of surplus power supplied to the single-phase low-voltage distribution line increases correspondingly, a large three-phase unbalanced current of the three-phase high-voltage distribution line will become constant. There is a possibility that overcurrent exceeding the rated current constantly flows in the current increasing phase due to the influence of the photovoltaic power generation equipment 4 in the three-phase load, and there is a concern that the durable life of the load may be shortened. .

  On the other hand, it is not clear which secondary winding to which the single-phase low-voltage distribution line is connected is electromagnetically coupled to which interphase winding of the three-phase primary winding because it depends on general electrical work. Is customary. In addition, grasping to which phase of the distribution system the photovoltaic power generation equipment is connected has not been carried out because the number of consumers is enormous and requires a great deal of labor. Conceivable.

  In addition, the three-phase unbalanced current of the three-phase high-voltage distribution line is also affected by the load connected to the single-phase low-voltage distribution line. It depends on the fluctuation of the load connected to the distribution line.

  However, as a result of various examinations and tests by the inventor, the current of each phase of the distribution line on the three-phase side of the distribution line transformer that converts the three phases to a single phase is detected, and each phase current is determined based on each phase current. It became clear from the tendency of the magnitude | size and change for every hour that the three-phase unbalanced current in the three-phase side originated in the photovoltaic power generation equipment.

  The technical basis will be explained below with examples.

  Each phase current measuring device 5, transmitter 6 and communication network 7 in FIG. 1 measure and transmit each phase current value data of a distribution line (three-phase / high voltage), and a predetermined value of about 1 minute of each phase current. The average value data of the time T1 is stored in the unbalance factor estimation processing device 8. Here, the point that the data to be stored is average value data and the average cycle are important, and by setting the average value for about 1 minute, random fluctuations that hinder subsequent analysis can be removed. Hereinafter, the 1-minute average is used for each phase current data.

Each phase current change detection unit 10 in FIG. 1 separates each phase current data into long-term variation data and short-term variation data by performing first-order lag processing with time correction of the time constant T2 on each phase current data. T2> T1.
Here, the primary delay processing with time correction of the time constant T2 is the first delay processing of the time constant T2 with respect to each phase current data, and further shifted forward by the time constant T2, whereby each phase current 1 minute. This is a process for creating each phase current long-term fluctuation data from the value average data.
The reason for shifting forward by the time constant T2 is that the time is delayed by T2 if the first-order lag processing is simply performed. It is appropriate that the time constant T2 is about 10 minutes.
Furthermore, each phase current short-term fluctuation data is created by subtracting each phase current long-term fluctuation data from each phase current data. Each phase current short-term fluctuation data is an average value of current value of about 1 minute, and the time constant T2 of the first-order lag processing is about 10 minutes, so short-term fluctuation is a fluctuation of about 1 to 10 minutes. .

  The three-phase current phase is composed of three phases: a-phase, b-phase, and c-phase. Fig. 2 shows a-phase current data and its long-term fluctuation data (a-phase current long-term fluctuation data) and short-term fluctuation. An image of data (a-phase current short-term fluctuation data) is shown. In FIG. 3, reference numeral 21 denotes a-phase current, 22 denotes a-phase current long-term fluctuation data, and 23 denotes a-phase current short-term fluctuation data.

The unbalance factor estimation unit 11 in FIG. 1 analyzes and estimates the unbalanced situation for each factor by comparing the current short-term fluctuation data of the a-phase, b-phase, and c-phase. FIG. 4 is an example of short-term fluctuation data comparison of each phase current.

FIG. 5 is an image obtained by plotting the short-term fluctuation data of each phase at each time section. The short-term fluctuation data of each phase current shown in FIG. 4 is a set of a phase, b phase, and c phase every minute (for example, , 31 in FIG.
FIG. 6 is an image diagram obtained by reading the section shown in FIG.
In other words, for example, at one plot point d1 in FIG. 5, the a-phase current value is Iad1, the b-phase current value is Ibd1, and the c-phase current value is Icd1, as shown.

Note that the plot is not for one day, but a single plot is created by summarizing periods of the past month.

In FIG. 5, the a-phase, b-phase, and c-phase are plotted as absolute values of short-term fluctuation data for easy understanding of the image.

Hereinafter, the grounds for estimating that the photovoltaic power generation facility is a three-phase current imbalance factor will be described with reference to FIGS. 4 and 5.
The generation source of each phase current short-term fluctuation data is roughly divided into the following two.
(1) Short-term fluctuations that occur when the amount of photovoltaic power generation for home use changes because the sun is temporarily hidden by the flow of clouds.
(2) Short-term fluctuations in load and short-term fluctuations in distributed power sources other than solar power generation.

The short-term fluctuations in (1) are limited to the solar power generation time zone (daytime), and in most cases, the short-term fluctuation is 1 to 10 minutes for the entire solar power generation equipment connected to the distribution line of interest. Variation occurs, and the short-term variation occurrence time is also random during the daytime period. 4 of FIG. 4 shows an example of a solar power generation time zone.
On the other hand, the short-term fluctuation in (2) is when the load connected to the distribution line of interest or the distributed power supply fluctuates all at once, for example, the factory stop at lunch break or the rise of the load of household load in the evening Due to planned factors or economic activities, short-term fluctuation occurrence times are concentrated. For example, if 32 short-term fluctuations in FIG. 4 are simultaneous fluctuations of the load, the same short-term fluctuations occur in the same time zone every day on weekdays. Reference numeral 42 in FIG. 5 is a short-term fluctuation plot example due to simultaneous fluctuations of such a load.

In addition, in the short-term fluctuation of (2), if the load or distributed power source connected to the distribution line of interest does not fluctuate all at once, the occurrence frequency is high, but each phase has a small short-term fluctuation, and as shown in FIG. As shown at 43, the plots are concentrated near the origin.
Furthermore, the occurrence of large-scale short-term fluctuations that are completely sudden or by chance is low in frequency and limited as the number of plots in FIG.

Therefore, most of the plots in FIG. 5 excluding the following plots are generated due to fluctuations in the amount of photovoltaic power generated by the cloud flow.
(A) Short-term fluctuation plot other than solar power generation time zone.
(B) Short-term fluctuation plot near the origin.
(C) A short-term fluctuation plot in which the ratio of short-term fluctuations in each phase (a phase: b phase: c phase) is equivalent and concentrated in the same time zone.

  A straight line (41c in FIG. 5) passing through the origin 0 of the graph of FIG. 5 and passing through the center of the dark portion of the plot density 41 with respect to the plot group 41 generated by the fluctuation of the photovoltaic power generation amount due to the cloud flow extracted in this way. Is obtained by multiple regression analysis. This straight line 41c shows the bias of the connection phase of a photovoltaic power generation equipment group.

1 is attached to the measuring instrument 5 of FIG. 1 or the transmitter 6 of FIG. 1, and the one-minute average value of the amount of solar radiation is synchronized with the current value data and taken into the unbalance factor estimation processing device 8 of FIG. By using only the short-term fluctuations of the respective phase current values that are synchronized with the short-term fluctuations of the amount of solar radiation, it is possible to obtain the bias of the connected phases of the photovoltaic power generation equipment group with higher accuracy.

  The connection phase estimation result presentation unit 12 of FIG. 1 displays information on the phase deviation as a whole of the household photovoltaic power generation connected to the single-phase low-voltage distribution line, short-term current fluctuations in a specific time zone, and information on the phase deviation. Presented to the operator by display, or presented as input information of another device.

  In this way, the system for detecting the effects on the three-phase distribution lines of photovoltaic power generation facilities that have three-phase imbalance detection and analysis and factor estimation functions, in particular, the general demand for single-phase power reception that does not centrally manage the information on the connected phases Regarding the photovoltaic power generation equipment installed in the house, it is possible to estimate and present the bias of the connection phase of the domestic photovoltaic power generation equipment for each distribution line.

  According to the first embodiment, for example, how the connection phase of the household photovoltaic power generation equipment is biased in the entire distribution line, how the connection phase of the load is biased, etc. The bias can be estimated. As a result, it is possible to estimate and present the unbalance factor without managing the connected phase data of a large number of customers, and it is expected that it can contribute to the unbalance countermeasure planning.

Connected phase management of general consumers, that is, to know which phase of the distribution system is connected to the load of home appliances and distributed power sources such as solar power generation facilities, the number of consumers is enormous This is not implemented because it requires a lot of labor, and there is no prospect of implementation in the future. For this reason, the cause and location of the three-phase imbalance caused by general consumers cannot be grasped, and it is difficult to plan an imbalance countermeasure.
On the other hand, when the three-phase unbalance rate of the power system increases due to the rapid spread of photovoltaic power generation facilities, actual damage such as overheating due to heat loss of the three-phase load occurs, and also from the viewpoint of distribution line overcurrent management Since only the phase is overloaded, the distribution line facility operation efficiency is reduced. As solar power generation will become more popular among general consumers in the future, it will become increasingly difficult to determine the cause and location of the three-phase imbalance, so that estimation and understanding will be important. The location of the occurrence can be identified accurately by installing each phase current measuring device in the vicinity of the section switch or the section switch because the position of the section switch is known.

  In Japan, since the installation of solar power generation facilities and their capacities are registered, the number and capacity of solar power generation facilities can be grasped numerically. It can be expected to contribute to planning, operation and control in the distribution system by being able to estimate and present the bias of the connected phase of the power generation equipment.

Embodiment 2. FIG.
Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG. 6 showing another example of the system configuration of the influence detection system for the three-phase distribution line of the photovoltaic power generation facility connected to the single-phase low-voltage distribution line.

  In the operation of the distribution system, one distribution line is divided into a plurality of sections and managed by a section switch or the like, and when power is interchanged from another route at the time of an accident, the availability of interchange is estimated for each section. Therefore, it is desirable to estimate and present the bias of the connection phase of the household photovoltaic power generation equipment in this section unit. As illustrated in FIG. 6, a plurality of current measuring devices 5 and transmitters 6 are arranged on one distribution line corresponding to each section switch, and the measurement data reception / storage unit 9 in FIG. By calculating the current difference at the measurement point and processing the current difference, it is possible to estimate the unbalance factor focusing on the consumers connected between the adjacent phase current measurement devices. However, it is necessary for each phase current measuring device to be synchronized.

  Thus, by arranging a plurality of synchronized phase current measuring devices on one distribution line, it is possible to estimate and present the bias of the connection phase of the household solar power generation facility for each more detailed area. .

  In addition, in each figure, the same code | symbol shows the same or an equivalent part.

According to the above-described first and second embodiments, the following technical features including those modifications are provided.
Feature 1: Each phase current measurement device that detects the current of each phase of the distribution line on the three-phase side of the distribution line transformer that converts three phases into a single phase, and each phase current measured by each phase current measurement device Based on the current distribution of each phase of the three-phase distribution line, the unbalance in the current of each phase of the three-phase distribution line is the sunlight installed in the single-phase low-voltage distribution line of the distribution transformer. It is an influence detection system to the three-phase distribution line of the photovoltaic power generation equipment provided with the estimation part which presumes that it originates in power generation equipment.
Feature 2: In the system for detecting the influence on the three-phase distribution line of the photovoltaic power generation facility of feature 1, the respective phase current measuring device is provided in a section switch provided on the three-phase side distribution line. This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line. Note that the phase current measuring devices are not necessarily provided in the section switches.
Feature 3: In the system for detecting the influence on the three-phase distribution line of the photovoltaic power generation facility of Feature 1 or Feature 2, the unit of division of the three-phase distribution line divided by the division switch provided on the three-phase distribution line The estimation part performs the said estimation, It is an influence detection system to the three-phase distribution line of the photovoltaic power generation equipment characterized by the above-mentioned.
Feature 4: In the system for detecting an influence on the three-phase distribution line of the photovoltaic power generation facility according to any one of features 1 to 3, the estimation unit receives each phase current information from the plurality of phase current measuring devices via a communication network. And detecting the influence on a three-phase distribution line of a photovoltaic power generation facility.
Feature 5: In the system for detecting the influence of the photovoltaic power generation facility on the three-phase distribution line of Feature 4, the estimation is performed from the current difference between the phase currents derived from the outputs of the adjacent phase current measuring devices. This is a system for detecting the influence of photovoltaic power generation facilities on three-phase distribution lines.
Feature 6: In the system for detecting an influence on the three-phase distribution line of the photovoltaic power generation facility according to any one of features 1 to 5, an average of each phase current measured by each phase current measuring device at each predetermined time t1 The estimation is performed based on the short-term fluctuation data obtained from the difference between each phase current data for which the value has been obtained and the long-term fluctuation data obtained by the first-order lag processing with the time constant t2 longer than the predetermined time t1. This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line.
Feature 7: In the system for detecting the influence of the photovoltaic power generation facility on the three-phase distribution line of feature 6, the phase current data is generated on the phase current measuring device side, and the long-term fluctuation data and the short-term data are generated on the estimation unit side. This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line, characterized in that fluctuation data is generated.
Feature 8: In the system for detecting the influence of the photovoltaic power generation facility on the three-phase distribution line of Feature 6, the phase current data and the long-term variation data are generated on the phase current measuring device side, and the estimation unit side This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line, characterized in that short-term fluctuation data is generated.
Feature 9: In the system for detecting the influence of the photovoltaic power generation facility on the three-phase distribution line of feature 6, the phase current data, the long-term variation data, and the short-term variation data are generated on the phase current measuring device side. This is a system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line.
Feature 10: Weather in which the output of the solar power generation equipment other than rainy weather, cloudy weather, and clear weather changes with time in the system for detecting the influence of the solar power generation equipment on the three-phase distribution line according to any one of features 1 to 9 A system for detecting an influence on a three-phase distribution line of a photovoltaic power generation facility, characterized in that the estimation is performed based on the phase currents within the sunshine hours.
Feature 11: Measurement data receiving / storing unit that receives and saves each phase current value data of distribution line (three-phase / high voltage), and each phase current change detection that separates each phase current value into long-term fluctuation part and short-term fluctuation part , An unbalance factor estimation unit that analyzes and estimates the bias of the connected phase from the long-term fluctuation part and the short-term fluctuation part of each phase current value, and a connection phase estimation result presentation part that provides the analysis result to humans or other devices Is provided as an internal function.
Feature 12: Measuring instrument that measures each phase current value of distribution lines (three-phase / high voltage), transmitter that sends measurement data (each phase current value) to the unbalance factor estimation processing device, and each phase current value A three-phase unbalance detection / analysis and factor estimation device comprising an unbalance factor estimation processing device for receiving, analyzing and presenting results.

1-1n Three-phase high-voltage distribution line,
2 Distribution line transformer,
3 Low voltage distribution customers
4 Solar power generation equipment,
5 Each phase current measuring device,
6 Transmitter,
7 Communication network,
8 monitoring terminals,
9 Measurement data consultation and storage department,
10 Each phase current change detector,
11 Unbalance factor estimation part,
12 connection phase estimation result presentation unit,
SW Division switch.

Claims (10)

  Each phase current measurement device that detects the current of each phase of the distribution line on the three-phase side of the distribution line transformer that converts three phases to a single phase, and each phase based on each phase current measured by each phase current measurement device Distinguishing the magnitude of current and the tendency of change every predetermined time, the current imbalance of each phase of the three-phase distribution line is in the photovoltaic power generation equipment installed in the single-phase low-voltage distribution line of the distribution line transformer An influence detection system for a three-phase distribution line of a photovoltaic power generation facility provided with an estimation unit for estimating the cause.   The influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to claim 1, wherein each of the phase current measuring devices is provided in a section switch provided in the three-phase side distribution line. Detection system for three-phase distribution lines of solar power generation facilities.   The influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to claim 1 or 2, wherein the unit of the three-phase distribution line is divided by a division switch provided on the three-phase distribution line. The estimation part performs the said estimation, The influence detection system to the three-phase distribution line of the solar power generation facility characterized by the above-mentioned.   The influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to any one of claims 1 to 3, wherein the estimation unit receives a plurality of phase currents from a plurality of phase current measuring devices via a communication network. A system for detecting an influence on a three-phase distribution line of a photovoltaic power generation facility, characterized by obtaining information and performing the estimation.   5. The system for detecting an influence on a three-phase distribution line of a photovoltaic power generation facility according to claim 4, wherein the estimation is performed from a current difference between phase currents derived from outputs of adjacent phase current measuring devices. A system for detecting the impact of photovoltaic power generation facilities on three-phase distribution lines.   In the influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to any one of claims 1 to 5, each phase current measured by each phase current measuring device for each predetermined time t1 The estimation is performed based on the short-term fluctuation data obtained by the difference between each phase current data for which the average value is obtained and the long-term fluctuation data obtained by the first-order lag processing with the time constant t2 longer than the predetermined time t1. A system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line.   The influence detection system for the three-phase distribution line of the photovoltaic power generation facility according to claim 6, wherein each phase current data is generated on the phase current measuring device side, and the long-term fluctuation data and the short-term data are generated on the estimation unit side. A system for detecting the influence of a photovoltaic power generation facility on a three-phase distribution line, wherein fluctuation data is generated.   In the influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to claim 6, the phase current data and the long-term variation data are generated on the phase current measuring device side, and the estimation unit side A system for detecting the effects of three-phase distribution lines on photovoltaic power generation facilities, characterized in that short-term fluctuation data is generated.   In the influence detection system to the three-phase distribution line of the photovoltaic power generation facility according to claim 6, the phase current data, the long-term variation data, and the short-term variation data are generated on the phase current measuring device side. A system for detecting the effects of solar power generation facilities on three-phase distribution lines. In the influence detection system to the three-phase distribution line of the photovoltaic power generation equipment according to any one of claims 1 to 9, in the weather in which the output of the photovoltaic power generation equipment other than rainy weather or cloudy weather and clear weather changes with time. An influence detection system for a three-phase distribution line of a photovoltaic power generation facility, wherein the estimation is performed based on each phase current within a sunshine period.

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