JP6723904B2 - Power system - Google Patents

Description

The present invention relates to an electric power system in which electric power supply equipment is provided in a premises.

A customer of low-voltage power reception receives electricity (commercial power) from an electric power company and uses the electricity in a load facility (general electric work) on the premises. In addition, a power supply facility such as a solar power generation facility is provided on the premises, a load facility is operated (for example, Patent Document 1), and surplus power of the power generated by the power supply facility is sold to a power company. Is also possible.

JP, 2013-247737, A

In the power supply equipment connected to the single-phase three-wire system 200V (R-phase and T-phase) in the single-phase three-wire system 100/200V, such as a solar power generation facility and a fuel cell, in the voltage lines R-phase and T-phase. Each is equipped with an ammeter (current transformer), the current value detected by each ammeter, the voltage values of the R and T phases detected by the power supply equipment, and the power factor value based on the current and voltage phase The received power is calculated from. In addition, in the power supply equipment, in order to properly derive the received power, based on the change in the current value of the ammeter due to the fluctuation of each internal load connected to the R phase and the T phase, the flow direction and phase position of the ammeter In some cases, the appropriateness of the ammeter installation such as soundness (disconnection of the signal line, etc.) (hereinafter simply referred to as "installation appropriateness") is judged.

Further, in the future, when energy-saving equipment becomes widespread and the power demand on the premises decreases, it is not always necessary to connect to the single-phase three-wire system 200V, and for example, one-phase three-wire system 100/200V It is conceivable to install a small output power supply facility that is connected only to the phase 3 wire system 100V (R phase and N phase, or T phase and N phase).

However, since such a small output power supply facility is connected to either the R phase or the T phase and the N phase, it is determined whether the installation is appropriate for one of the two ammeters attached to the R phase and the T phase. become unable. Also, if an ammeter that cannot judge the installation suitability is replaced with an N-phase, it becomes possible to judge the installation suitability for that ammeter as well, but there is a problem that the received power cannot be directly derived by the existing procedure.

In view of the above problems, the present invention determines the appropriateness of installation of an ammeter and the received power even if the power supply facility is connected only to the single-phase, three-wire R-phase or T-phase and the N-phase. The purpose is to provide an electric power system that can derive

In order to solve the above problems, the power system of the present invention is a power supply connected to either one of R phase or T phase and N phase of a single-phase three-wire system which is a service line from a power system. Equipment, one of R phase or T phase, and a first ammeter and a second ammeter for measuring the current value flowing in each N phase, and a current value measured by each of the first ammeter and the second ammeter Of the R phase or the T phase based on the first ammeter and the second ammeter, and the appropriateness determination section that determines the installation suitability of each of the first ammeter and the second ammeter. A current value estimation unit that estimates a current value to obtain an estimated current value, a value obtained by multiplying the interphase voltage value related to one of the R phase and the T phase, the current value of the voltage line, and its power factor, and the estimated value A power deriving unit that adds the current value and a value obtained by multiplying the assumed power factor to derive the received power.

The power derivation unit may use, as the assumed value, one of the specified minimum voltage value and the specified maximum voltage value that can be taken as the interphase voltage value, depending on the direction of the estimated current value.

An electric power meter that is connected to the electric power system and can measure the interphase voltage value related to the other of the R phase and the T phase may be provided, and the power derivation unit may use the interphase voltage value measured by the electric power meter as the assumed value.

The power derivation unit statistically processes the inter-phase voltage value measured by the power meter, and according to the direction of the estimated current value, one of the statistically derived actually measured minimum voltage value and actually measured maximum voltage value is set as the assumed value. Good.

ADVANTAGE OF THE INVENTION According to this invention, even if it is the electric power supply equipment connected only to R phase or T phase of a single-phase 3-wire type, and N phase, it is possible to judge the installation suitability of an ammeter and to derive received power. Become.

It is explanatory drawing which showed the connection relation of an electric power system. It is a block diagram for explaining a concrete connection mode of electric power supply equipment and a branch wiring. It is explanatory drawing for demonstrating the subject of installation suitability determination of an ammeter. It is the flowchart which showed the flow of the installation method of an ammeter. It is an explanatory view for explaining correspondence between a voltage line connection point and an ammeter connection point. It is the flowchart which showed the flow of the appropriate determination of an ammeter. It is an explanatory view for explaining correspondence between a voltage line connection point and an ammeter connection point. It is explanatory drawing for demonstrating the power flow direction and the electric current value by the magnitude of load. It is the flowchart which showed the flow of the appropriate determination of an ammeter. It is explanatory drawing which showed the structure for performing appropriateness judgment. It is explanatory drawing for demonstrating the other subject of electric power supply equipment. It is explanatory drawing which showed the connection relation of an electric power system.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit redundant description, and elements not directly related to the present invention are omitted. To do.

(Power system 100)
FIG. 1 is an explanatory diagram showing a connection relationship of the power system 100. In FIG. 1, the movement of power is indicated by a solid line, and the signal including information is indicated by a dashed arrow. The power system 100 receives electricity (commercial power) from the power system 12 through the service line 10. The electric power system 100 is configured on a consumer unit basis, and the range is not limited to houses and the like as long as it is a general electric facility (consumer of low-voltage power reception), hospitals, factories, hotels, leisure facilities, and commerce. It may be a building unit such as a facility or a condominium or a part of the building.

The power system 100 also includes a power meter 112, a distribution board 114, a power supply facility 116, and an ammeter 118.

The electric power meter (electric energy meter) 112 is connected to the electric power system 12 via the service line 10 and measures a current value (consumption and power sale) flowing between the service line 10 and the power system 100.

The distribution board 114 is connected to the electric power meter 112, and has a service breaker (service breaker) 114a that indicates a contracted capacity, an earth leakage breaker (leakage breaker) 114b that shuts off the supply of electricity in response to detection of electric leakage, and a plurality of Each of the branch wirings 120 has a wiring breaker (safety breaker) 114c that shuts off the supply of electricity when the allowable current value (for example, 20 A) is exceeded. Further, the load equipment 14 is connected to the branch wiring 120, and the load equipment 14 can be supplied with power from the power system 12 through the branch wiring 120.

In addition, although the service breaker 114a is mentioned here as a structure of the distribution board 114, the service breaker 114a itself may not be installed and the service breaker 114a may be provided in the electric power meter 112. ..

The power supply equipment 116 is connected to any of the plurality of branch wirings 120 in the distribution board 114 (to a single-phase three-wire system 100V relating to one of the single-phase three-wire system 100/200V), and in the power generation section G. Other energy is converted into electric energy to generate electricity, and the generated electricity is supplied to the load facility 14 in the premises in priority to the power system 12. In addition, here, the R phase and the T phase of the single-phase three-wire system 100/200V (single-phase three-wire system) shown in FIG. 2 described later are referred to as the single-phase three-wire system 200V, and the R-phase and the N-phase, Alternatively, the T phase and the N phase are referred to as single-phase three-wire type 100V.

As the power supply facility 116, a solar power generator, a wind power generator, a hydraulic power generator, a geothermal power generator, a solar thermal power generator, an atmospheric thermal power generator, a fuel cell, a storage battery, an internal combustion power generation, or the like can be used. In addition, the power supply facility 116 is configured by an internal load 116a such as a surplus heater and an instrument transformer (VT) and the like, and outputs a single-phase three-wire system 100V (R phase or T phase and N phase) interphase voltage value. It has a voltmeter 116b for measuring, a disconnecting section 116c for cutting off the power supply (output) from the power generation section G, and a control unit 116d for controlling the entire power supply facility 116.

The control unit 116d is configured by a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing programs and the like, a RAM as a work area, and the like. Here, an example in which the control unit 116d is formed integrally with the power supply equipment 116 is described, but it may be provided as a separate body. The control unit 116d also functions as the load control unit 140, the measurement value acquisition unit 142, the adequacy determination unit 144, the current value estimation unit 146, and the power derivation unit 148 by operating the program. The functional part of the control unit 116d will be described later in detail.

The ammeter 118 is composed of, for example, a current transformer (CT), and inserts (clamps) any phase wiring into each of the penetrating bodies (iron core, core) in which the primary windings are arranged, and the current value ( The effective value and its direction) are converted into measured values and transmitted to the control unit 116d. Here, the forward power flow direction is positive for the R and T phases, and the direction from the power supply facility 116 to the power system 12 is positive for the N phase. In addition, for convenience of explanation, it is simply set to any one of the R phase, the T phase, and the N phase (one of the single-phase three-wire 100/200V (for example, the R phase and the N phase) or the other (for example, the T phase and the N phase)). The single-phase three-wire type 100V) is used as an example, but more accurately, it is attached to the secondary side of the power meter 112 and the primary side of the wiring breaker 114c in FIG. It is common. The ammeter 118 may be installed at any position on the power system 12 side of the load facility 14.

Although the details will be described later, in the above-described power supply equipment 116, the current value measured by the ammeter 118 connected to each phase and connected to the ammeter 118 and the interphase of each phase measured by the power supply equipment 116. The received power is derived from the voltage value and the power factor value based on the current and voltage phases. With such received power, it is possible to realize constant received power control, RPR (reverse power relay) function, and UPR function (insufficient power relay).

In addition, the power supply equipment 116, in order to appropriately derive the received power, based on the change in the current value of the ammeter 118 associated with the variation of each internal load 116a connected to each phase in the own machine, the flow of the current of the ammeter 118. In some cases, proper installation is judged such as direction (polarity), phase position (attached phase), soundness (breakage of signal line, malfunction of ammeter 118, etc.) (also referred to as CT check). For example, when the soundness cannot be ensured during the operation of the power supply facility 116, the power generation of the power supply facility 116 is stopped.

By the way, the power supply facility 116 is generally used by connecting to a single-phase three-wire system 200V of the single-phase three-wire system 100/200V. In this case, an interconnecting circuit breaker (200V) is provided in place of the circuit breaker 114c, the power supply equipment 116 is connected to the interconnecting circuit breaker, and a separate individual circuit is provided from the primary side of the earth leakage circuit breaker 114b. The power supply equipment 116 must be connected via a circuit breaker (200V).

However, in the future, when energy-saving equipment becomes widespread and the power demand of the power system 100 decreases, it is not always necessary to connect to the single-phase three-wire system 200V. Connected to only single-phase 3-wire system 100V (R phase and N phase, or T phase and N phase) consisting of either R phase or T phase which is a power line of 200V and N phase which is a neutral line The small output power supply facility 116 is installed. If the single-phase three-wire system 100V can be operated in this way, the existing branch wiring 120 can be used to connect the power supply facility 116 to an outdoor outlet, for example, as shown in FIG. Wiring can be simplified.

FIG. 2 is a block diagram for explaining a specific connection mode between the power supply equipment 116 and the branch wiring 120. As described above, the small output power supply equipment 116 is connected to the single-phase three-wire system 100V that is connected to one of the voltage lines (electric wires on the non-grounded side). For example, when the power supply equipment 116 is connected to the R phase side, as shown in FIG. 2A, the R phase is connected to the voltage line connection point A, which is one of the power output terminals of the power supply equipment 116. The N phase is connected to the neutral line connection point B which is the other of the output ends. In this case, the interconnection phase of the power supply equipment 116 is the R phase, and the non-interconnection phase is the T phase. Further, one of the two ammeters 118 (the first ammeter 118a and the second ammeter 118b) is connected to the first ammeter connection point C, which is the current input terminal of the power supply equipment 116, and the other one. Is connected to the second ammeter connection point D.

Even when the power supply equipment 116 is connected to the T phase side, as shown in FIG. 2B, the T phase is present at the voltage line connection point A, which is one of the power output terminals of the power supply equipment 116. The N-phase is connected to the neutral line connection point B which is the other end of the output terminal. In this case, the interconnection phase of the power supply facility 116 is the T phase, and the non-interconnection phase is the R phase. Further, one of the two ammeters 118a and 118b is connected to the first ammeter connection point C that is the current input terminal of the power supply equipment 116, and the other is connected to the second ammeter connection point D. To be done.

In this embodiment, as described above, the single-phase three-wire system 100V on either the R-phase side or the T-phase side can be connected. In the following embodiments, for convenience of description, the case where the R phase is an interconnected phase, that is, the case where the R phase and the N phase are connected to a single-phase three-wire system 100V will be described. It is needless to say that the present invention can be applied to the case where is an interconnected phase, that is, the case where it is connected to a single-phase three-wire system 100V of T phase and N phase.

(First embodiment: determination of appropriateness of installation of ammeter)
As described above, since the small output power supply equipment 116 is connected to either the R phase or the T phase and the N phase, even if an attempt is made to vary the load, the R output or the T phase is connected to either the R phase or the T phase. Only the connected internal load 116a can be changed. Therefore, the following problems arise in the determination of the installation suitability.

FIG. 3 is an explanatory diagram for explaining the problem of determining whether the ammeter is installed properly. It is assumed that the power supply facility 16 is connected to the single-phase three-wire type 200V as shown in FIG. Here, the R phase is connected to the voltage line connection point A, the T phase is connected to the voltage line connection point AA, and the N phase is connected to the neutral line connection point B among the output ends of the power of the power supply equipment 16. To be done. Then, one of the two ammeters 118a and 118b attached to the interconnection phase is connected to the first ammeter connection point C that is the current input terminal of the power supply equipment 16, and the other is the second ammeter. It is connected to the connection point D.

Here, the neutral wire (N phase) can be connected to the neutral wire connection point B based on that the coating of the voltage wire is red or black and the neutral wire is white, and the voltage wire connection It is possible to connect the points A and AA to the voltage line (R phase or T phase), but which of the voltage line connection point A and the voltage line connection point AA is connected to the R phase and which is connected to the T phase? Cannot be visually confirmed because the distance between indoors and outdoors is large.

Further, both of the two ammeters 118a and 118b can be attached to the voltage line (R phase or T phase) based on the coating of the voltage line being red or black, but the ammeter 118a and the ammeter 118b Which of the two is attached to the R phase and which is attached to the T phase cannot be visually confirmed due to the distance limitation. Further, since the distance between the ammeter 118 and the power supply equipment 16 is long, which of the two ammeters 118a and 118b is connected to the first ammeter connection point C and which is connected to the second ammeter connection point D. It cannot be visually confirmed if it is present. That is, either of the first ammeter connection points C and D is connected to the neutral line connection point B (N phase), and which is connected to either of the voltage line connection points A and AA (R phase or T phase). I can't confirm if it is done.

However, in the power supply facility 16, the voltage line connection points A and AA do not necessarily require information on which voltage line is connected, and the voltage line connection points A and AA and the ammeter connection points C and D are not necessary. The received power can be derived as long as they can be associated with each other, that is, if the correlation between the phase positions can be grasped.

Therefore, in the power supply facility 16 connected to the single-phase three-wire system 200V, first, the internal load 16a connected to the voltage line connection point A is changed. Here, it is assumed that the current value I _R of the R phase fluctuates due to the fluctuation of the internal load 16a. Then, depending on the change in the current value I _R , either the current value I ₁ input to the first ammeter connection point C or the current value I ₂ input to the second ammeter connection point D changes. Determine whether to do. Then, the changed ammeter connection point (here, the first ammeter connection point C) and the voltage line connection point A are associated with each other.

Then, the internal load 16b connected to the voltage line connection point AA is changed. Here, the current value I _T T-phase by variation of the internal load 16b is varied. Then, in accordance with a variation in the current value I _T, and the current value I ₁ which is input to the first ammeter connection point C, any variation between the current value I ₂ is input to the second ammeter connection point D Determine whether to do. Then, the changed ammeter connection point (here, the second ammeter connection point D) is associated with the voltage line connection point AA.

As described above, in the power supply facility 16 connected to the single-phase three-wire type 200V, the voltage line connection points A and AA and the ammeter connection points C and D can be easily associated with each other through the two internal loads 16a and 16b. Therefore, it is possible to judge the phase position and soundness of the proper installation. Further, if the association is determined, it is possible to appropriately determine other parameters (direction of power flow) that are appropriate for installation of the two ammeters 118a and 118b.

However, the small output power supply equipment 116 is connected to either the R phase or the T phase and the N phase as shown in FIG. 3B, and thus is connected to either the R phase or the T phase. Only one internal load 116a can be changed. Therefore, when judging in the same procedure as the power supply equipment 16 connected to the single-phase three-wire type 200V, both of the two ammeters 118a and 118b follow and fluctuate, and the two ammeter connection points (first It is not possible to determine which of the ammeter connection point C and the second ammeter connection point D) corresponds to the voltage line connection point (interconnection phase or neutral line). Therefore, in the present embodiment, the procedure is improved so that the voltage line connection point (interconnection phase or neutral line) and the ammeter connection point are appropriately associated with each other, and the electric power is connected only to the single-phase three-wire system 100V. Even in the supply facility 116, the purpose is to determine the appropriateness of installation of the ammeter.

FIG. 4 is a flowchart showing the flow of the installation method of the ammeter 118 (ammeter installation method), and FIG. 5 shows the correspondence between the voltage line connection point (interconnection phase or neutral line) and the ammeter connection point. It is an explanatory view for explaining attachment. In the installation method shown in FIG. 4, the phase position and soundness of the installation suitability can be determined by associating the ammeter with each phase (interconnected phase, non-connected phase, neutral line).

(Step S10)
First, as shown in FIG. 5A, the voltage line connection point A of the power supply equipment 116 is connected to one of the voltage lines (R phase or T phase) (here, R phase). Then, the neutral wire connection point B of the power supply facility 116 is connected to the neutral wire (N phase).

(Step S11)
Subsequently, as shown in FIG. 5B, one first ammeter 118a of the ammeter 118 is attached to either one of the voltage lines (R phase or T phase). In addition, the wiring of the first ammeter 118a is connected to one of the ammeter connection points of the power supply facility 116 (here, the first ammeter connection point C). At this time, the second ammeter 118b is not yet connected to the power supply equipment 116.

(Step S12)
Next, the load control unit 140 changes the internal load 116a connected to the single-phase three-wire system 100V, and the measurement value acquisition unit 142 causes the measurement value acquisition unit 142 to measure the current value through the first ammeter connection point C, that is, the first current. The current value measured by the total 118a is acquired. Then, the adequacy determining unit 144 determines whether or not the current value follows and fluctuates within an assumed predetermined range according to the fluctuation of the internal load 116a, and determines whether the first ammeter 118a (the first ammeter connection point C). ) To the connected phase (voltage line connection point A) or the non-connected phase. Specifically, if the current value changes, the first ammeter 118a is associated with the interconnected phase, and if the current value does not change, the first ammeter 118a is associated with the non-connected phase.

(Step S13)
Subsequently, as shown in FIG. 5C, the other second ammeter 118b is attached to the neutral wire (N-phase) without disconnecting the connection of the first ammeter 118a. Further, the wiring of the second ammeter 118b is connected to the other of the ammeter connection points of the power supply equipment 116 (here, the second ammeter connection point D).

(Step S14)
Next, the appropriateness determination unit 144 associates the neutral line (neutral line connection point B) with the second ammeter 118b (second ammeter connection point D).

(Step S15)
Subsequently, the appropriateness determining unit 144 determines whether or not the non-interconnection phase is associated with the first ammeter 118a. As a result, if the non-connected phase is not associated, that is, if the first ammeter 118a is associated with the connected phase, the ammeter installation method is terminated and the non-connected phase is associated. If so, the process proceeds to step S16.

(Step S16)
When it is determined in step S15 that the non-interconnection phase is associated with the first ammeter 118a, a process for associating the interconnection phase with the first ammeter 118a is performed, and the ammeter installation method ends. For example, the first ammeter 118a attached to one voltage line is replaced with the other voltage line. In this way, the appropriateness determination unit 144 can associate the first ammeter 118a (first ammeter connection point C) with the interconnection phase (voltage line connection point A).

Further, as described above, even if the first ammeter 118a is not replaced, it is recognized that the first ammeter 118a is attached to the non-interconnection phase, and the current value I ₁ of the first ammeter 118a and the second ammeter 118a It is also possible to derive the current value of the interconnection phase from the current value I ₂ of the ammeter 118b.

For example, the single-phase three-wire 100 / 200V, the direction of the current value _{I N} N-phase, the current value if _{the I R} is the direction of flow of the N-phase, current _I N = R phase current value of the N-phase current _{I T} of the I _R -T phase is established. Therefore, if the first ammeter 118a is attached to the non-interconnection phase (T phase), the current value I _R of the interconnection phase (R phase) is the current value of the N phase I _N +T phase current. the value _{I T,} i.e., the ability to derive by adding the current value _{I 1} of the first ammeter 118a to a current value _{I 2} of the second ammeter 118b. Note that, here, for convenience of description, the direction of the current value is simply described, but the current is originally an alternating current, and the direction of the current value actually indicates a power flow direction according to the current value. In the following calculation, the direction of the current value will be simply described, but it goes without saying that the power flow direction according to the current value is actually shown.

With this configuration, which of the two ammeters 118a and 118b corresponds to the interconnection phase or the neutral line even in the power supply facility 116 connected only to the single-phase three-wire system 100V (phase position) Can be appropriately judged. Further, if the association is determined, it is possible to appropriately determine the other installation suitability (the power flow direction and the soundness) of the two ammeters 118a and 118b.

It should be noted that the determination as to whether or not the two ammeters 118a and 118b are properly installed may be performed after the association of the two ammeters 118a and 118b with the interconnection phase or the like is completed, or stepwise, that is, the first Installation of the first ammeter 118a is determined after the first ammeter 118a is associated with the interconnection phase, and the second ammeter 118b is installed after the second ammeter 118b is associated with the neutral line. You may judge the suitability.

Further, in the above-described ammeter installation method, the first ammeter 118a is randomly attached to either one of the voltage lines (R phase or T phase) in step S11. Therefore, the first ammeter 118a is always associated with the non-interconnection phase with a probability of 50%. Therefore, before attaching the first ammeter 118a, it is determined by an outlet checker or the like whether or not the voltage line is connected to the voltage line connection point A of the power supply equipment 116, and the connected voltage line is determined. The first ammeter 118a may be attached. With this configuration, in step S12, the first ammeter 118a and the interconnection phase can be reliably associated with each other.

(Second embodiment: determination of proper installation of ammeter)
As described above, in the low-output power supply equipment 116, since either the R phase or the T phase and the N phase are connected, only the internal load 116a connected to either the R phase or the T phase changes. I can't let you do it. Therefore, in the first embodiment, the installation order of the two ammeters 118a and 118b is devised to determine which corresponds to the interconnection phase or the neutral line. The second embodiment is intended to automatically determine not only the compatibility with the interconnection phase and the neutral line but also the installation suitability of the two ammeters 118a and 118b in a connected state. ..

FIG. 6 is a flowchart showing the flow of the appropriate determination (appropriate determination method) of the ammeter 118, and FIG. 7 shows the correspondence between the voltage line connection point (interconnection phase or neutral line) and the ammeter connection point. It is an explanatory view for explaining. In the adequacy determination method shown in FIG. 6, among the installation adequacy, the phase position and soundness are determined.

(Step S20)
First, as shown in FIG. 7, the voltage line connection point A of the power supply facility 116 is connected to one of the voltage lines (R phase or T phase) (here, R phase), and the power supply facility 116 is neutralized. The line connection point B is connected to the neutral line (N phase).

Subsequently, one of the ammeters 118, the first ammeter 118a, is attached to one of the voltage lines (R phase or T phase) (here, the R phase), and the wiring of the first ammeter 118a is The power supply equipment 116 is connected to one of the ammeter connection points (here, the first ammeter connection point C). Further, the other second ammeter 118b of the ammeter 118 is attached to the neutral wire (N phase), and the wiring of the second ammeter 118b is connected to the other of the ammeter connection points of the power supply equipment 116 (here, Connect to the second ammeter connection point D).

(Step S21)
Next, the measurement value acquisition unit 142 determines the current value through the first ammeter connection point C, that is, the current value I ₁ measured by the first ammeter 118a and the current through the second ammeter connection point D. The value, that is, the current value I ₂ measured by the second ammeter 118b is acquired. Then, the current values I ₁ and I ₂ are held as the current values I _1o and I _2o before the change of the internal load 116a.

(Step S22)
Subsequently, the load control unit 140 changes (for example, increases) the internal load 116a connected to the single-phase three-wire system 100V in the power supply equipment 116.

(Step S23)
Next, the measurement value acquisition unit 142 determines the current value through the first ammeter connection point C, that is, the current value I ₁ measured by the first ammeter 118a and the current through the second ammeter connection point D. The value, that is, the current value I ₂ measured by the second ammeter 118b is acquired.

(Step S24)
Subsequently, the measurement value acquisition unit 142 subtracts the absolute values (effective values) of the current values I _1o and I _2o held in step S21 from the acquired absolute values (effective values) of the current values I ₁ and I ₂ , respectively. Then, the current differences Δ|I ₁ | and Δ|I ₂ | showing the variation of the absolute values of the current values I ₁ and I ₂ are derived (Δ|I ₁ |=|I ₁ |−|I _1o |, Δ|I ₂ |=|I ₂ |−|I _2o |). Hereinafter, based on the current value I ₁ measured by the first ammeter 118a, the current difference Δ|I ₁ |, the current value I ₂ measured by the second ammeter 118b, and the current difference Δ|I ₂ | Make an appropriate decision. In the following description, when it is determined whether or not the current value I ₁ , the current difference Δ|I ₁ |, the current value I ₂ , and the current difference Δ|I ₂ | are equal, only whether or not they are theoretically equal. , And other factors such as measurement error and noise of the ammeter 118 are excluded. Therefore, for example, when comparing the current difference Δ|I ₁ | and the current difference Δ|I ₂ |, the theoretical current difference Δ|I ₁ |=the current difference Δ|I ₂ | , |(current difference Δ|I ₁ |−current difference Δ|I ₂ |)|< error.

(Step S25)
Next, the adequacy determining unit 144 determines whether or not the current differences Δ|I ₁ | and Δ|I ₂ | are other than 0, that is, the current difference Δ|I ₁ | according to the fluctuation of the internal load 116 a. , Δ|I ₂ | are respectively changed. As a result, if neither is 0, the process proceeds to step S27, and if either is 0, the process proceeds to step S26.

(Step S26)
If it is determined in step S25 that one of the current differences Δ|I ₁ | and Δ|I ₂ | is 0, the appropriateness determining unit 144 determines that the ammeter 118 having a current difference of 0 determines that the internal load 116a. It is determined that the first ammeter 118a is not attached to the interconnection phase but to the non-interconnection phase (disconnection phase installation error), and the appropriate determination method ends. Here, as described above, the ammeter 118 determined to be attached to the non-interconnection phase is replaced with the other voltage line, or the current value I ₁ of the first ammeter 118a and the second ammeter 118b is changed. The current value of the interconnection phase can be derived from the current value I _{2 of} the above and applied.

(Step S27)
If it is determined in step S25 that the current differences Δ|I ₁ | and Δ|I ₂ | are both other than 0, the appropriateness determining unit 144 determines that the current difference Δ|I ₁ | and the current difference Δ|I. ₂ | is equal to or not (actually, |(current difference Δ|I ₁ |−current difference Δ|I ₂ |)|<error amount). In this determination, it is determined which of the R phase load and the T phase load is larger. Hereinafter, the basis for the determination will be described in detail.

FIG. 8 is an explanatory diagram for explaining the power flow direction and the current value depending on the magnitude of the load. For example, when the R-phase load is relatively larger than the T-phase load as shown in FIG. 8A, the current value I ₁ and the current value I ₂ are indicated by white arrows in FIG. 8A. As described above, both are positive values. Then, when the internal load 116a is increased, both the current value I ₁ and the current value I ₂ change from a positive value to a positive value having a larger absolute value. For example, when the current value I ₁ increases from 5A to 7A by 2A according to the increase of the internal load 116a, the current value I ₂ increases from 1A to 3A by 2A. Here, since all the values before and after the increase in the current value I ₁ and the current value I ₂ positive value, the current value I ₁ and the current value I ₂ increase in absolute value, the current value I ₁ and the current value I ₂ It becomes 2A, which is equal to the increase in the value. Therefore, the current difference Δ|I ₁ | and the current difference Δ|I ₂ | due to the fluctuation of the internal load 116a become equal.

On the other hand, when the R-phase load is relatively smaller than the T-phase load as shown in FIG. 8B, the current value I ₁ is a positive value as indicated by the white arrow in FIG. 8B. While the current value I ₂ shows a negative value. Then, when the internal load 116a is increased, the current value I ₁ changes from a positive value to a positive value with a larger absolute value, while the current value I ₂ changes from a negative value to a negative value with a smaller absolute value. Value, or from a negative value to a positive value. Therefore, although the amount of increase in current value is equal, the amount of increase in absolute value of current value is not equal.

For example, when the current value I ₁ increases 2A from 5A to 7A according to the increase of the internal load 116a, the current value I ₂ increases 2A from -3A to -1A. However, regarding the absolute value, the absolute value of the current value I ₁ increases by 2 A from 5 A to 7 A, while the absolute value of the current value I ₂ decreases by 2 A from 3 A to 1 A. Further, when the current value I ₁ increases by 2 A from 5 A to 7 A according to the increase of the internal load 116 a, the current value I ₂ increases by 2 A from −0.5 A to 1.5 A. However, regarding the absolute value, the absolute value of the current value I ₁ is increased by 2 A from 5 A to 7 A, whereas the absolute value of the current value I ₂ is increased by 1 A from 0.5 A to 1.5 A. Therefore, the current difference Δ|I ₁ | and the current difference Δ|I ₂ | due to the fluctuation of the internal load 116a are not equal.

Then, when the current difference Δ|I ₁ | and the current difference Δ|I ₂ | are equal, the R-phase load is relatively larger than the T-phase load, and the current difference Δ|I ₁ | and the current difference Δ|I _{If 2} | is not equal, the R-phase load is relatively smaller than the T-phase load.

Therefore, in step S27, if the current difference Δ|I ₁ | and the current difference Δ|I ₂ | are equal, the appropriateness determining unit 144 shifts the processing to step S28, and the current difference Δ|I ₁ | and the current difference Δ. If |I ₂ | is not equal, the appropriateness determining unit 144 moves the process to step S33.

(Step S28)
If it is determined in step S27 that the current difference Δ|I ₁ | and the current difference Δ|I ₂ | are equal, the appropriateness determining unit 144 determines that the current value I ₁ and the current value I ₂ acquired in step S23 are equal to each other. To compare. This is for the following reason.

That is, as shown in FIG. 8A, when the R-phase load is relatively larger than the T-phase load, the N-phase current value _IN is equal to the _R -phase current value IR-T-phase current. unless next value I _T, the current value I _T T-phase non-zero, the absolute value than the current value I _R of R-phase is reduced. Therefore, when the load of the R phase is relatively larger than the load of the T phase, the one with a relatively large absolute value of the current becomes the current value I _{R of the} R phase, and the one with a relatively small absolute value of the current is N. a current value _{I N} phases.

Therefore, in step S28, if the absolute value of the current value I ₁ is larger than the absolute value of the current value I ₂ , the appropriateness determining unit 144 shifts the processing to step S29, and the absolute value of the current value I _{1 is} the current value I _1. If it is less than or equal to the absolute value of ₂ , the process proceeds to step S30.

(Step S29)
When it is determined in step S28 that the absolute value of the current value I ₁ is larger than the absolute value of the current value I ₂ , the appropriateness determination unit 144 determines that the first ammeter 118a (the first ammeter connection point C) is selected. The interconnection phase (voltage line connection point A) is associated, and the neutral line (neutral line connection point B) is associated with the second ammeter 118b (second ammeter connection point D), and the appropriateness determination method ends. To do.

(Step S30)
If it is determined in step S28 that the absolute value of the current value I ₁ is less than or equal to the absolute value of the current value I ₂ , the appropriateness determining unit 144 determines that the absolute value of the current value I _{1 is} the absolute value of the current value I ₂ . Is smaller than. As a result, if the absolute value of the current value I ₁ is smaller than the absolute value of the current value I ₂ , the appropriateness determining unit 144 shifts the processing to step S31, and the absolute value of the current value I _{1 is} the absolute value of the current value I ₂ . If it is not smaller than the value, that is, if the absolute value of the current value I _{1 and} the absolute value of the current value I ₂ are equal, the appropriateness determination unit 144 moves the process to step S32.

(Step S31)
If it is determined in step S30 that the absolute value of the current value I ₁ is smaller than the absolute value of the current value I ₂ , the appropriateness determining unit 144 determines that the second ammeter 118b (the second ammeter connection point D) is selected. The interconnection phase (voltage line connection point A) is associated, and the neutral line (neutral line connection point B) is associated with the first ammeter 118a (first ammeter connection point C), and the appropriateness determination method ends. To do.

(Step S32)
If it is determined in step S30 that the absolute value of the current value I ₁ is not smaller than the absolute value of the current value I ₂ , the appropriateness determining unit 144 installs the two ammeters 118a and 118b in the same phase, It is determined that the current value is being measured (in-phase installation error), and the appropriateness determination method ends.

(Step S33)
If it is determined in step S27 that the current difference Δ|I ₁ | and the current difference Δ|I ₂ | are not equal, the appropriateness determining unit 144 determines that the current difference Δ|I ₁ | and the current difference Δ|I ₂ | Compare with |. This is for the following reason. Here, the soundness is also determined together with the phase position.

That is, as described with reference to FIG. 8B, when the R-phase load is relatively smaller than the T-phase load, the current value I ₁ changes from a positive value as the internal load 116a increases. , The absolute value changes to a larger positive value, while the current value I ₂ changes from a negative value to a smaller negative value, or changes from a negative value to a positive value .. For example, when the current value I ₁ increases by 2 A as the internal load 116a increases, the current value I ₂ also increases by ₂ A. However, regarding the absolute value, the absolute value of the current value I ₁ increases from 5 A to 7 A by 2 A. On the other hand, the absolute value of the current value I _{2 only} decreases from 3A to 1A by 2A or increases from 0.5A to 1.5A by 1A. Thus, the absolute value of the current value I ₂ decreases or increases smaller than the current value I ₁ . Therefore, when the load of the R phase is relatively larger than the load of the T phase, the one in which the current difference ΔI is relatively large (the one that is positive) becomes the current difference ΔI _{R in the} R phase, and the current difference ΔI is relatively large. smaller (who is negative) is the current difference [Delta] I _N N-phase.

Therefore, in step S33, if the current difference Δ|I ₁ | is larger than the current difference Δ|I ₂ | and the current difference Δ|I ₁ | is larger than the threshold value (current threshold value), the appropriateness determination unit 144 determines If the current difference Δ|I ₁ | is less than or equal to the current difference Δ|I ₂ | or if the current difference Δ|I ₁ | is less than or equal to the current threshold, the appropriateness determining unit 144 determines , And moves the processing to step S35. Note that the current threshold value here is a value that is smaller than the current difference ΔI that is assumed for fluctuations in the internal load 116a and is greater than 0, and may be, for example, 1/2 of the assumed current difference ΔI. ..

(Step S34)
If it is determined in step S33 that the current difference Δ|I ₁ | is larger than the current difference Δ|I ₂ | and the current difference Δ|I ₁ | is larger than the current threshold value, the appropriateness determining unit 144 determines that The one ammeter 118a (first ammeter connection point C) is associated with the interconnection phase (voltage line connection point A), and the second ammeter 118b (second ammeter connection point D) is connected to the neutral line (neutral line). The connection point B) is associated, and the appropriateness determination method ends.

(Step S35)
If it is determined in step S33 that the current difference Δ|I ₁ | is less than or equal to the current difference Δ|I ₂ | or the current difference Δ|I ₁ | is less than or equal to the current threshold value, the appropriateness determining unit 144 is determined. a current difference Δ | _{I 1} | current difference Δ | _{I 2} | smaller than, and current difference Δ | _{I 2} | determines greater or not than the current threshold. As a result, if the current difference Δ|I ₁ | is smaller than the current difference Δ|I ₂ | and the current difference Δ|I ₂ | is larger than the current threshold value, the appropriateness determination unit 144 shifts the processing to step S36, The current difference Δ|I ₁ | is not smaller than the current difference Δ|I ₂ | (the current difference Δ|I ₁ | and the current difference Δ|I ₂ | are equal), or the current difference Δ|I ₂ | is the current If it is less than or equal to the threshold value, the appropriateness determining unit 144 moves the process to step S37.

(Step S36)
In step S35, if it is determined that the current difference Δ|I ₁ | is smaller than the current difference Δ|I ₂ | and the current difference Δ|I ₂ | is larger than the current threshold value, the appropriateness determining unit 144 determines that The second ammeter 118b (second ammeter connection point D) is associated with the interconnection phase (voltage line connection point A), and the first ammeter 118a (first ammeter connection point C) is neutralized (neutral line). The connection point B) is associated, and the appropriateness determination method ends.

(Step S37)
If it is determined in step S35 that the current difference Δ|I ₁ | is not smaller than the current difference Δ|I ₂ | or the current difference Δ|I ₂ | is less than or equal to the current threshold value, the appropriateness determining unit 144 determines that It is determined that the two ammeters 118a and 118b are not healthy (unhealthy error), and the appropriateness determination method ends.

According to the appropriateness determining method, it is possible to determine the phase position and soundness of the installation appropriateness.

FIG. 9 is a flow chart showing the flow of the appropriateness determination (property determination method) of the ammeter 118, and FIG. 10 is an explanatory diagram showing the configuration for performing the appropriateness determination. In the adequacy determination method shown in FIG. 9, the adequacy of the power flow direction is determined for the two ammeters 118a and 118b whose phase position and soundness have been determined by the adequacy determination method of FIG.

(Step S40)
First, as shown in FIG. 10, the measurement value acquisition unit 142 acquires the waveform of the interphase voltage (including information about the phase change) through the voltmeter 116b.

(Step S41)
Then, the measurement value acquisition unit 142, as shown in FIG. 10, the current waveform through the first ammeter connection point C (including information on the phase change), that is, the current waveform measured by the first ammeter 118a. , And the current waveform through the second ammeter connection point D, that is, the current waveform measured by the second ammeter 118b is acquired.

(Step S42)
Next, the measurement value acquisition unit 142 compares the acquired waveform of the interphase voltage with the current waveform measured by the first ammeter 118a, and determines whether the phase difference is larger than a threshold value (phase threshold value). As a result, if it is larger than the phase threshold value, the appropriateness determining unit 144 shifts the processing to step S43, and if it is equal to or lower than the phase threshold value, shifts the processing to step S44 without performing any phase operation. Here, the phase threshold value is a value of 90 degrees or less, for example, 10 degrees, at which it can be determined that the phase is not inverted.

(Step S43)
If it is determined in step S42 that the phase difference is larger than the phase threshold, the appropriateness determining unit 144 determines that the power flow direction of the first ammeter 118a is opposite, and the current through the first ammeter connection point C is determined. The waveform, that is, the phase of the current waveform measured by the first ammeter 118a is inverted or delayed by 180 degrees for recognition.

(Step S44)
Subsequently, the measurement value acquisition unit 142 compares the acquired waveform of the interphase voltage with the current waveform measured by the second ammeter 118b, and determines whether the phase difference is larger than a threshold value (phase threshold value). As a result, if it is larger than the phase threshold value, the appropriateness determining unit 144 moves the process to step S45, and if it is equal to or less than the phase threshold value, the appropriateness determining method ends without performing any phase operation.

(Step S45)
If it is determined in step S44 that the phase difference is larger than the phase threshold, the appropriateness determining unit 144 determines that the power flow direction of the second ammeter 118b is opposite, and the current through the second ammeter connection point D is determined. The waveform, that is, the phase of the current waveform measured by the second ammeter 118b is inverted or delayed by 180 degrees for recognition.

According to the appropriateness determining method, it is possible to correct the tidal current direction in the installation appropriateness.

In addition, in the first embodiment and the second embodiment, an example in which the load control unit 140 changes the internal load 116a provided inside the power supply equipment 116 has been described, but the present invention is not limited to such a case. An external load connected to the single-phase three-wire 100V equal to the power supply facility 116 may be changed.

(Third embodiment: Derivation of received power)
Next, a process of deriving the received power using the two ammeters 118a and 118b whose installation suitability has been determined will be described.

FIG. 11 is an explanatory diagram for explaining another problem of the power supply equipment 116. It is assumed that the power supply facility 16 is connected to the single-phase three-wire type 200V. Here, the R phase is connected to the voltage line connection point A, the T phase is connected to the voltage line connection point AA, and the N phase is connected to the neutral line connection point B among the output ends of the power of the power supply equipment 16. To be done. Then, one of the two ammeters 118a and 118b is connected to the first ammeter connection point C, which is the current input terminal of the power supply equipment 16, and the other is connected to the second ammeter connection point D. ..

Then, as shown in FIG. 11A, the first ammeter 118a measures the current value I _R of the R phase, which is the voltage line, and the second ammeter 118b measures the current value I _T of the T phase, which is the voltage line. Suppose you have measured. Further, it is assumed that the voltmeter 16c provided in the power supply equipment 16 measures the interphase voltage value VR of the _R phase with respect to the N phase, and the voltmeter 16d measures the interphase voltage value V _T of the T phase with respect to the N phase.

Based on the measured current values I _R and I _T and interphase voltage values V _R and V _T , the product of the current value, the interphase voltage value, and the power factor (for each phase (R phase, T phase)) _{I R × V R × cosθ R} , when obtaining the _{I T × V T × cosθ T} ), the sum _{(I R × V R × cosθ} R + I T × V T × cosθ T) is the received power. With such received power, it is possible to realize the constant received power control, the RPR function, the UPR function, and the like.

However, in the case where the power supply equipment 116 is connected to the single-phase three-wire system 100V as in the present embodiment, if two ammeters 118a and 118b are attached to the voltage lines R phase and T phase, one is not connected. Since it is an interconnected phase, it is impossible to judge the installation suitability of the ammeter 118. Further, as shown in FIG. 11B, if the ammeter 118, which cannot determine the installation suitability, is replaced with the N phase, the installation suitability of the ammeter 118 can also be determined. Since the interphase voltage cannot be grasped, there is a problem that the received power cannot be derived by the existing procedure as described with reference to FIG.

Therefore, an object of the present invention is to estimate the current value and the inter-phase voltage of the non-interconnection phase and to derive the received power while performing the determination of the installation suitability of the ammeter 118.

In the power supply facility 116 of the present embodiment, as shown in FIG. 11B, the first ammeter 118a is connected to either the R phase or the T phase, and the second ammeter 118b is connected to the N phase. It Therefore, the first ammeter 118a can measure the R-phase current value I _R , and the second ammeter 118b can measure the N-phase current value I _N. Then, the measurement value acquisition unit 142 acquires the current value I _R and the current value I _N. However, the T-phase current value I _T necessary to derive the received power cannot be measured.

However, as described above, when the direction of the current _{I R} of the current value _{I N} N-phase is the direction of flow of the N phase, the single-phase three-wire 100 / 200V, the current value of N phase _I N = R The phase current value I _R −T phase current value I _T holds. Then, if grasp the current value I _N of the current value I _R and N phase of R-phase, it is possible to estimate the current value I _T T-phase. Therefore, the current value estimation unit 146 estimates the current value I _T of the T-phase, which is the voltage line in the other single-phase three-wire system 100V, based on the first ammeter 118a and the second ammeter 118b to estimate the estimated current. _{Let the} value I _TA .

Specifically, the current value estimation unit 146, a current value _{I N} of the current value _I R -N-phase R-phase, i.e., the current value from the current value _{I 1} of the first ammeter 118a second ammeter 118b _{I 2} It becomes possible to derive the estimated current value I _TA of the T phase by subtracting.

Further, when the power supply equipment 116 is connected to the single-phase three-wire system 100V, the connected inter-phase voltage value of the single-phase three-wire system 100V (here, the inter-phase voltage of the R phase is used, as shown in FIG. 11B). the value _{V R)} can be measured. The measurement value acquisition unit 142 obtains the phase voltage _{V R.} However, although the interphase voltage value of the connected single-phase three-wire system 100V (here, the interphase voltage value VR of the _R phase) can be detected, the interphase voltage value of the other unconnected single-phase three-wire system 100V. (Here, the interphase voltage value V _T of the T phase) cannot be detected. Here, by estimating the interphase voltage value V _T of the other single-phase three-wire system 100 V that cannot be measured, it is combined with the above estimated current value I _TA and the power supply facility connected to the single-phase three-wire system 200 V is substantially used. The received power is derived under the same condition.

By the way, according to the Electricity Business Law, the interphase voltage value of the electric power supplied from the electric power company is determined to be within the range of 101V±6V. Therefore, the interphase voltage value of the T phase fluctuates only within the range of 95V (specified minimum voltage value) to 107V (specified maximum voltage value). Therefore, when the power system 100 allows reverse power flow (interconnection with reverse power flow), it is within the range that can be taken as the interphase voltage value and the voltage drop of the lead-in wire 10 (for example, 2 V) is taken into consideration. As the assumed value V _TA of the interphase voltage value of the T phase, for example, 101 V that is the center value can be selected.

In addition, in such a power system 100, since the loads of the R phase and the T phase are often close to uniform, the assumed value V _TA of the interphase voltage value of the T phase is, for example, that of the R phase which is the interconnection phase. the interphase voltage value V _R, may be diverted as it is. With such a configuration, the power flow at the power receiving point can be made close to 0, and the power generated by the power supply facility 116 can be effectively used. Since the R phase and the T phase are often 180 degrees different in phase, the assumed power factor cos θ _TA is, for example, the phase of the interphase voltage with respect to the N phase of the T phase, which is the non-connected phase, in the connected phase. The assumed power factor cos θ _TA may be determined by regarding the phase of the interphase voltage with respect to the N phase of a certain R phase as being the phase inverted (180° different).

In addition, when the power system 100 does not allow reverse power flow (connection without reverse power flow), the power derivation unit 148 determines the estimated value V _TA and the estimated power factor cos θ _TA according to the direction of the other T-phase current. May be determined. For example, it is assumed that the T-phase current is flowing in a reverse power flow direction (direction different from the dashed arrow in FIG. 11B). At this time, the inter-phase voltage value V _T of the T phase can fluctuate in the range from the specified minimum voltage value (95 V) to the specified maximum voltage value (107 V), so that the power related to the T phase is (current value I _T ×specified minimum value). It changes in the range of (voltage value) to (current value _IT ×specified maximum voltage value). Here, it is clarified that the reverse power flow does not occur by taking a value of (current value _IT ×specified maximum voltage value) on the safe side. That is, the power deriving unit 148 sets the specified maximum voltage value as the assumed value V _TA when the T-phase current is flowing in the reverse power flow direction. Further, in order to make a strict (safety) determination of the power shortage, the assumed power factor cos θ _TA may be regarded as 1 so that the T-phase power becomes maximum.

Similarly, when the T-phase current flows in the direction in which the reverse power flow does not occur (the direction equal to the broken line arrow in FIG. 11B), the power derivation unit 148 determines the estimated value V _TA as the safe minimum value. Set the voltage value. Further, in order to make a strict (safety) determination of the power shortage, the assumed power factor cos θ _TA may be regarded as a predetermined value (for example, 0) and calculated so that the power of the T phase is minimized.

With such a configuration, when reverse power flow is not allowed, the safest received power is calculated when the power supply facility 116 connected only to the single-phase three-wire system 100V is converted into the single-phase three-wire system 100/200V. Therefore, the reverse power flow of the power supply equipment 116 can be appropriately avoided.

Then, the power derivation unit 148 determines the estimated current value I _TA as the current value of the T phase, the predetermined assumed value V _TA as the interphase voltage value of the T phase, and the predetermined assumed power as the power factor of the interphase voltage of the T phase. The power received by the single-phase three-wire system 100/200 V is derived with reference to the rate cos θ _TA . Specifically, the power deriving unit 148 obtains the power (I _R ×V _R ×cos θ _R ) related to the R phase and the assumed power (I _TA ×V _TA ×cos θ _TA ) related to the T phase, and the sum (I _R × and _{V R × cosθ R + I TA} × V TA × cosθ TA) to derive terms have been received power of single-phase three-wire 100 / 200V.

With such a configuration, even in the power supply facility 116 connected only to the single-phase three-wire system 100V, it is possible to appropriately obtain the received power of the single-phase three-wire system 100/200V.

(Fourth Embodiment: Power System 200)
FIG. 12 is an explanatory diagram showing a connection relationship of the power system 200 according to the fourth embodiment. In the electric power system 200, the process of the electric power deriving unit 248 is different from that of the third embodiment, but other components are substantially the same as those of the third embodiment.

In the fourth embodiment, the power derivation unit 248 does not fixedly select the estimated value, acquires information regarding the interphase voltage value from any device of the power system 200, and based on the information, sets the estimated value at any time. decide. For example, in the example of FIG. 12, the power derivation unit 248 acquires the interphase voltage value in the power meter 112, specifically, the interphase voltage value of a phase different from the phase to which the power supply facility 116 is connected, and The interphase voltage value is assumed.

With this configuration, a value close to the original inter-phase voltage value can be set as the assumed value V _TA, and the received power can be obtained more accurately.

However, depending on the update frequency of the interphase voltage value of the power meter 112, a value different from the original interphase voltage value will be referred to. For example, when the power meter 112 is updated only once in several tens of seconds, the interphase voltage value to be referred to may be the interphase voltage value of several tens of seconds ago. Therefore, the power derivation unit 248 may accumulate the inter-phase voltage value V _T in the power meter 112 and statistically process it to determine the assumed value.

For example, the power deriving unit 248 accumulates the interphase voltage value for an arbitrary past period (year, month, week, day, time, etc.) in the power meter 112, and the minimum voltage value during that period (measured minimum voltage value). And the maximum voltage value (measured maximum voltage value). Here, since the interphase voltage value V _T of the T phase fluctuates in the range from the actually measured minimum voltage value to the actually measured maximum voltage value, the power related to the T phase is calculated from (current value I _T ×measured minimum voltage value) ( It will fluctuate within the range of (current value _IT ×measured maximum voltage value).

Here, when the T-phase current flows in the direction in which the T-phase current flows in the reverse direction (direction different from the dashed arrow in FIG. 11B), the power deriving unit 248 sets the assumed value V _TA to the measured maximum value on the safe side. Set the voltage value. Further, when the T-phase current flows in the direction in which the reverse power flow does not occur (the direction equal to the broken line arrow in FIG. 11B), the power deriving unit 248 sets the assumed minimum value V _TA to the measured minimum voltage on the safe side. Set the value.

With such a configuration, it is possible to obtain the received power on the safest side when the power supply equipment 116 connected only to the single-phase three-wire system 100V is converted into the single-phase three-wire system 100/200V.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such embodiments. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope described in the claims, and naturally, they also belong to the technical scope of the present invention. Understood.

For example, in the above-described embodiment, the example in which the power meter 112 transmits the inter-phase voltage value to the control unit 116d has been described, but when the power meter 112 is a smart meter, its function, for example, HEMS( It may be transmitted from the power meter 112 to the control unit 116d through the Home Energy Management System).

Further, in the above-described embodiment, an example in which interphase voltage values for an arbitrary period in the past are accumulated and a minimum voltage value (actually measured minimum voltage value) and a maximum voltage value (actually measured maximum voltage value) between them are obtained is given. Although described, the effective minimum voltage value (measured minimum voltage value) and maximum voltage value (measured maximum voltage value) may be obtained from statistically derived statistical deviations, for example.

INDUSTRIAL APPLICABILITY The present invention can be used in an electric power system in which electric power supply equipment is provided on the premises.

10 service line 100 power system 112 power meter 114 distribution board 116 power supply equipment 116a internal load 116b voltmeter 116d control unit 118a first ammeter (ammeter)
118b Second ammeter (ammeter)
140 load control unit 142 measured value acquisition unit 144 appropriateness determination unit 146 current value estimation unit 148, 248 power derivation unit

Claims (4)

A power supply facility connected to either one of the R phase or the T phase and the N phase of the single-phase three-wire system that is a service line from the power system,
A first ammeter and a second ammeter for measuring the current value flowing in one of the R phase or the T phase and the N phase, respectively,
A measurement value acquisition unit that acquires current values measured by the first ammeter and the second ammeter, respectively;
An adequacy determining unit that determines the installation adequacy of each of the first ammeter and the second ammeter,
A current value estimation unit that estimates the other current value of the R phase or the T phase based on the first ammeter and the second ammeter to obtain an estimated current value;
A value obtained by multiplying the interphase voltage value relating to one of the R phase or the T phase, the current value of the voltage line and the power factor thereof, and an estimated value, a value obtained by multiplying the estimated current value and the assumed power factor are added. A power derivation unit that derives received power,
Power system comprising. The power system according to claim 1, wherein the power derivation unit uses, as the assumed value, one of a specified minimum voltage value and a specified maximum voltage value that can be taken as an interphase voltage value according to the direction of the estimated current value. A power meter that is connected to the power system and can measure an interphase voltage value related to the other of the R phase and the T phase,
The power system according to claim 1, wherein the power deriving unit sets the inter-phase voltage value measured by the power meter as the assumed value. The power derivation unit statistically processes the inter-phase voltage value measured by the power meter, depending on the direction of the estimated current value, one of the statistically derived actually measured minimum voltage value and actually measured maximum voltage value. The power system according to claim 3, wherein the assumed value is used.

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