JP7618372B2 - Computer program for determining the wiring connection status of electronic watt-hour meters - Google Patents

Description

The present invention relates to a computer program that determines the connection state of wiring connected to an electronic watt-hour meter.

Conventionally, one such computer program for determining the connection state of wiring connected to an electronic watt-hour meter is disclosed in, for example, Patent Document 1. This computer program inputs various measurement data from the electronic watt-hour meter to a computer as measurement values, and also inputs the rated capacity and phase angle of a simulated load as load values. Then, using the apparent power value and phase difference determined based on the rated capacity and phase angle of the simulated load as basic data, it calculates the active power value and reactive power value between each of two specified pairs of phases in each connection state of the wiring as theoretical values. Then, it compares the measured value with the theoretical value, and identifies the connection state of the wiring according to the theoretical value that is closest to the measured value.

Patent No. 6804172

However, at the installation site of the electronic watt-hour meter, the voltage actually applied to the electronic watt-hour meter may fluctuate. When the voltage applied to the electronic watt-hour meter fluctuates, the measurement value input from the electronic watt-hour meter to the computer also fluctuates in the above conventional computer program. Since the calculation formula of the active power value W and the reactive power value var includes the term ^V2 /R, if the voltage V fluctuates by, for example, 10%, the measurement value of the active power value W and the reactive power value var fluctuates by 20%. Of the error factors that affect the determination of the wiring misconnection of the electronic watt-hour meter, the most influential factor is this voltage fluctuation. Therefore, in the conventional computer program, the accuracy of the determination of the connection state of the wiring connected to the electronic watt-hour meter, which is specified from the comparison result between the measurement value and the theoretical value, is reduced by this voltage fluctuation.

The present invention has been made to solve such problems,
Computer ,
an information input means for inputting a phase wire system and a rated voltage value of the electronic watt-hour meter as meter information; and, when the phase wire system of the electronic watt-hour meter input by the information input means is a single-phase three-wire system, a measurement value input means for inputting an active power value and a reactive power value measured by the electronic watt-hour meter for each phase between a neutral line and each voltage line of a three-wire single-phase power source as measurement values, and an inter-phase voltage of 70 [V] to 130 [V] or 140 [V] to 260 [V] between each phase as a voltage measurement value. a measurement value correction means for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 100[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 70[V] to 130[V], and for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 200[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 140[V] to 260[V]; a load value input means for inputting a rated capacity and a phase angle of a dummy load to be connected to the electronic watt-hour meter; and a theoretical value calculation means for calculating, as theoretical values, active power values and reactive power values for each phase in each connection state of the wiring connected to the electronic watt-hour meter from the basic data acquired by the basic data acquisition means; a table creation means for creating a table that specifies the relationship between the theoretical values calculated by the theoretical value calculation means and each connection state of the wiring; a comparison means for comparing a corrected measurement value of a value corrected by the measurement value correction means with a theoretical value specified in the table created by the table creation means; and a wiring connection state determination program for determining a theoretical value having a value closest to the corrected measurement value from the comparison result of the comparison means and specifying the connection state of the wiring according to the determined theoretical value.

In addition , the computer
An information input means for inputting the phase and wire system and rated voltage value of the electronic watt-hour meter provided separately from the computer as meter information, and when the phase and wire system of the electronic watt-hour meter input by the information input means is a single-phase three-wire system, the active power value and reactive power value measured by the electronic watt-hour meter for each phase between the neutral line and each voltage line of a three-wire single-phase power source and output from the external communication port of the electronic watt-hour meter are used as measurement values, and the phase-to-phase voltage of 70 [V] to 130 [V] or 140 [V] to 260 [V] between each phase is measured as a measurement value. a measurement value input means for inputting a voltage measurement value from an external communication port via a sensor; a measurement value correction means for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 100[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 70[V] to 130[V], and for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 200[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 140[V] to 260[V]; and a measurement value correction means for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 200[V] of the electronic watt-hour meter based on the voltage measurement value. The present invention provides a wiring connection state determination program for an electronic watt-hour meter, which includes a basic data acquisition means for acquiring the difference as basic data from the corrected measurement values corrected by the measurement value correction means, a theoretical value calculation means for calculating, from the basic data acquired by the basic data acquisition means, active power values and reactive power values between each phase in each connection state, including a normal connection state and an incorrect connection state, of the wiring connected to the terminal portion of the electronic watt-hour meter, as theoretical values, a table creation means for creating a table that specifies the relationship between the theoretical values calculated by the theoretical value calculation means and each connection state of the wiring, a comparison means for comparing the corrected measurement values of the values corrected by the measurement value correction means with the theoretical values specified in the table created by the table creation means, and a wiring connection state determination program for an electronic watt-hour meter, which functions as a determination means that determines the theoretical value having a value closest to the corrected measurement value from the comparison result of the comparison means, and specifies the connection state of the wiring connected to the terminal portion when the electronic watt-hour meter is installed as either a normal connection state or an incorrect connection state depending on the determined theoretical value.

According to these configurations , for each phase of a three- wire single-phase power source, active power values and reactive power values are input from the electronic watt-hour meter to the computer as measurement values by the measurement value input means, and the phase-to-phase voltage is input as a voltage measurement value. Then, the measurement value input by the measurement value input means is corrected by the measurement value correction means to a corrected measurement value corresponding to the rated voltage value of the electronic watt-hour meter based on the voltage measurement value. The comparison means compares the corrected measurement value corrected by the measurement value correction means with a theoretical value defined in the table created by the table creation means. The determination means determines the theoretical value having a value closest to the corrected measurement value from the comparison result of the comparison means, and specifies the connection state of the wiring connected to the terminal portion when the electronic watt-hour meter was installed according to the determined theoretical value.

Therefore, by having the computer execute a program that causes the computer to function as each of the above means, the measurement value that is compared with the theoretical value that is the basis for calculating the rated voltage value of the electronic watt-hour meter becomes a corrected measurement value that corresponds to the rated voltage value of the electronic watt-hour meter. This makes it possible to accurately determine the connection state of the wiring connected to the electronic watt-hour meter without being affected by voltage fluctuations at the installation site of the electronic watt-hour meter.

According to the present invention, it is possible to provide a computer program that can accurately determine the connection state of the wiring connected to an electronic watt-hour meter without being affected by voltage fluctuations at the installation site of the electronic watt-hour meter.

1 is a connection diagram between a personal computer to which a computer program according to an embodiment of the present invention is applied and an electronic watt-hour meter. 2 is a block diagram showing an internal configuration of the personal computer shown in FIG. 1. 1 is a first table showing a comparison between a table created by a computer program according to an embodiment and a correction value of a measurement value input from an electronic watt-hour meter; FIG. FIG. 11 is a second table showing a comparison between a table created by the computer program according to the embodiment and a correction value of a measurement value input from an electronic watt-hour meter; FIG. 11 is a third table showing a comparison between a table created by the computer program according to the embodiment and a correction value of a measurement value input from an electronic watt-hour meter; FIG. 6 is a table following the third table shown in FIG. 5 .

Next, we will explain how to implement the computer program for determining the wiring connection status of an electronic electricity meter according to the present invention.

Figure 1 is a connection diagram between a personal computer (hereinafter referred to as PC) 1 to which a computer program for determining the wiring connection state of an electronic watt-hour meter according to one embodiment of the present invention is applied as an application, and an electronic watt-hour meter 2.

The electronic watt-hour meter 2 is constructed by incorporating components such as an electronic circuit board into a rectangular parallelepiped housing. The electronic watt-hour meter 2 has a display unit 2a that displays the measured value on its front side, and a terminal unit 2b below which each wire is connected. In this embodiment, the electronic watt-hour meter 2 is a three-phase three-wire type, and a power supply voltage is applied to each of the power supply terminals P1, P2, and P3 of the terminal unit 2b from the power supply wires of phases 1, 2, and 3 of the three-phase power supply via a VT (voltage converter). The P1 terminal is connected to the output terminal 1u of the VT, the P2 terminal is connected to the grounded output terminals 1v and 3u, and the P3 terminal is connected to the output terminal 3v.

Between output terminals 1u and 1v of the VT, the phase-to-phase voltage between phases 1 and 2 of the three-phase power supply appears, and between output terminals 3u and 3v, the phase-to-phase voltage between phases 2 and 3 of the three-phase power supply appears. Therefore, the phase-to-phase voltage on the 1 side between phases 1 and 2 of the three-phase power supply is applied between terminals P1 and P2, and the phase-to-phase voltage on the 3 side between phases 3 and 2 of the three-phase power supply is applied between terminals P3 and P2. Here, phases 1 and 2 and phases 2 and 3 constitute two predetermined pairs of phases of the three-phase power supply. Furthermore, the phase-to-phase voltage on the 1 side and the phase-to-phase voltage on the 3 side constitute two predetermined pairs of phase-to-phase voltages of the three-phase power supply.

When checking the wiring connection status of the electronic watt-hour meter 2, if the actual load 6 is not connected to the three-phase power supply, the dummy load 3 is connected to the three-phase power supply. When the actual load 6 is connected to the three-phase power supply, the dummy load 3 does not have to be connected, but the dummy load 3 may be connected to the three-phase power supply together with the actual load 6. In this embodiment, the dummy load 3 is connected to the three-phase power supply when obtaining the theoretical value described below, and the actual load 6 is connected to the three-phase power supply when checking the wiring connection status of the electronic watt-hour meter 2.

The simulated load 3 is a load for checking the wiring connection when the electronic watt-hour meter 2 is installed, and the load capacity is known in advance. In this embodiment, a 100 [μF] phase-advancing capacitor is used for the simulated load 3, and its rated capacity is 726 [VA] (rated voltage 200 [V], rated current 3.63 [A]), and the phase angle of the load, which is the power factor angle, is 90°. When the real load 6 is connected, a line current corresponding to the load capacity of the real load 6 flows in each of the first and third phases of the three-phase power supply. The line current flowing in the first phase of the three-phase power supply is detected between the 1S terminal and the 1L terminal of the terminal section 2b from the power supply wiring of the first phase via the output terminals 1K and 1L of the CT (current transformer), and the line current flowing in the third phase is detected between the 3S terminal and the 3L terminal of the terminal section 2b from the power supply wiring of the three phase via the output terminals 3K and 3L of the CT. The 1L terminal and the 3L terminal are grounded together with the P2 terminal.

The electronic watt-hour meter 2 calculates the signed 1-side active power value W1 and 1-side reactive power value var1 by multiplying the 1-side interphase voltage P1 applied between the P1 and P2 terminals by the 1-side line current I1 detected between the 1S and 1L terminals. It also calculates the signed 3-side active power value W3 and 3-side reactive power value var3 by multiplying the 3-side interphase voltage P3 applied between the P3 and P2 terminals by the 3-side line current I3 detected between the 3S and 3L terminals. It then calculates the combined active power value ΣW of the 1-side active power value W1 and the 3-side active power value W3, and the combined reactive power value Σvar of the 1-side reactive power value var1 and the 3-side reactive power value var3. The electronic watt-hour meter 2 also calculates the voltage phase difference θp1-p3 between the 1-side interphase voltage P1 and the 3-side interphase voltage P3.

The electronic watt-hour meter 2 has an infrared communication port and a metering pulse output port (not shown) on its front side. From this infrared communication port, various measurement data measured by the electronic watt-hour meter 2 are output by infrared to the outside of the electronic watt-hour meter 2. In this embodiment, as this measurement data, active energy Wh, reactive energy varh, active power (total active power ΣW), reactive power (total reactive power Σvar), phase-to-phase voltage P1 on side 1, phase-to-phase voltage P3 on side 3, etc. are output. In addition, from the infrared communication port, meter information of the electronic watt-hour meter 2 and setting information set in the electronic watt-hour meter 2 are also output. In this embodiment, as this meter information, a meter ID that identifies the serial number and year of manufacture of the electronic watt-hour meter 2, a phase line type of the electronic watt-hour meter 2, a rated voltage, and a rated current are output. Additionally, the setting information includes the multiplying factor for the display value on the display unit 2a, the VT/CT transformation ratio constant, and the pulse type, pulse constant, and pulse width of the metering pulse output from the metering pulse output port.

The PC1 detects the infrared rays output from the infrared communication port with a sensor 4, and inputs various measurement data measured by the electronic watt-hour meter 2, together with the meter information and setting information, via a cable 5. Note that in this embodiment, communication between the electronic watt-hour meter 2 and the PC1 is performed by infrared communication, but it can also be performed by other communication methods such as a serial communication method such as RS485, a current loop communication method, or a wireless communication method.

Figure 2 is a block diagram showing the general configuration inside PC1. In PC1, CPU (Central Processing Unit) 13 performs various calculations according to a program stored in ROM (Read Only Memory) 11, using RAM (Read and Write Memory) 12 as a temporary storage work area. Through these calculations according to the program stored in ROM 11, CPU 13 causes PC1, which is a computer, to function as measurement value input means 21, measurement value correction means 21a, load value input means 22, basic data acquisition means 23, theoretical value calculation means 24, table creation means 25, comparison means 26, discrimination means 27, information input means 28, and data output means 29.

The measurement value input means 21 inputs various measurement data including the active power values W1, W3 and reactive power values var1, var3 measured by the electronic watt-hour meter 2 for each of two predetermined pairs of phases as measurement values, and the interphase voltages P1, P3 as voltage measurement values, from the electronic watt-hour meter 2 via the sensor 4 and cable 5. The measurement value correction means 21a corrects the measurement values of the active power values W1, W3 and reactive power values var1, var3 input by the measurement value input means 21 to corrected measurement values corresponding to the rated voltage value of the electronic watt-hour meter 2, based on the voltage measurement values input by the measurement value input means 21.

The corrected measurement values of the active power value W1 and the reactive power value var1 are calculated from the measurement values of the active power value W1 and the reactive power value var1, the rated voltage value VR of the electronic watt-hour meter 2, and the phase-to-phase voltage P1, for example, as shown in the following equation (1-1).
Corrected measurement value (W1, var1) = Measurement value (W1, var1) × (VR/P1) ² … (1-1)

In addition, the corrected measurement values of the active power value W3 and the reactive power value var3 are calculated from the measurement values of the active power value W3 and the reactive power value var3, the rated voltage value VR of the electronic watt-hour meter 2, and the phase-to-phase voltage P3, for example, as shown in the following equation (1-2).
Corrected measurement value (W3, var3) = measurement value (W3, var3) × (VR / P3) ² … (1-2)

The load value input means 22 inputs the rated capacity and phase angle of the simulated load 3 connected to the electronic watt-hour meter 2 as load values from the keyboard 14 of the PC 1, etc. The basic data acquisition means 23 acquires the apparent power values PI1, PI3 between each of two predetermined pairs of phases and the phase differences θ1, θ3 of the line currents I1, I3 relative to the phase-to-phase voltages P1, P3 as basic data. In this embodiment, the basic data acquisition means 23 acquires the apparent power values PI1, PI3 and the phase differences θ1, θ3 calculated based on the rated capacity and phase angle of the simulated load 3 input to the load value input means 22 as basic data.

In this embodiment, a three-phase balanced load is used as the dummy load 3, so the theoretical values of the apparent power values PI1, PI3 and the phase differences θ1, θ3 on sides 1 and 3 are equal to each other, and are expressed by the following equations (2-1) and (2-2) from the load value of the dummy load 3.
PI1=PI3=200[V]×3.63[A]=726[VA]…(2-1)
θ1=θ3=90°…(2-2)

The theoretical value calculation means 24 calculates the active power values W1, W3 and reactive power values var1, var3 between each of two predetermined pairs of phases in each connection state of the wiring connected to the electronic watt-hour meter 2 as theoretical values from the basic data acquired by the basic data acquisition means 23, using a calculation formula described below. The table creation means 25 creates a table that specifies the relationship between the theoretical values calculated by the theoretical value calculation means 24 and each connection state of the wiring. The comparison means 26 compares the corrected measurement value of the value corrected by the measurement value correction means 21a with the theoretical value specified in the table created by the table creation means 25. The determination means 27 determines the theoretical value having a value closest to the corrected measurement value from the comparison result of the comparison means 26, and specifies the connection state of the wiring according to the determined theoretical value.

In this embodiment, the measurement value input means 21 inputs the voltage phase difference θp1-p3 between the phase-to-phase voltage P1 on side 1 and the phase-to-phase voltage P3 on side 3, which is between two predetermined pairs of phase-to-phase voltages, from the electronic watt-hour meter 2. The comparison means 26 further compares the voltage phase difference θp1-p3 input by the measurement value input means 21 with the voltage phase difference of 300° between the phase-to-phase voltage P1 on side 1 and the phase-to-phase voltage P3 on side 3, which is the predetermined voltage phase difference. The determination means 27 further refers to the comparison result of the comparison means 26 between the voltage phase difference θp1-p3 and the predetermined voltage phase difference of 300° to identify the connection state of the wiring.

The information input means 28 inputs meter information of the electronic watt-hour meter 2 and setting information set in the electronic watt-hour meter 2 from the electronic watt-hour meter 2 via the sensor 4 and cable 5. The data output means 29 outputs information on the wiring connection state identified by the discrimination means 27 as data together with the meter information and setting information input by the information input means 28. This data output is performed according to the USB standard from the USB port 15 provided in the PC 1 and is output as PDF data or table data, or is performed to the printer 16 and output on paper.

3 to 6 show a part of the table created by the table creation means 25. The table shows a connection diagram showing each connection state of the wiring connected to the electronic watt-hour meter 2, a connection terminal correspondence table showing the connection relationship between each terminal corresponding to the connection diagram, and a calculation formula and vector diagram of theoretical values corresponding to each connection state of the wiring. The vector diagram shows the relative phase relationship between two predetermined pairs of interphase voltages P1, P3 and line currents I1, I3 in each connection state of the wiring. The calculation formula of theoretical values is used to calculate the theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in the theoretical value calculation means 24, and the calculation results calculated by the calculation formula (not shown) are specified in the table as theoretical values corresponding to each connection state of the wiring.

The theoretical values specified in the table are compared by the comparison means 26 with the corrected measurement values corrected by the measurement value correction means 21a. The measurement results shown in the figure next to the table indicate the corrected measurement values, etc., of the values input by the measurement value input means 21 when the wiring is connected as shown in the table and corrected by the measurement value correction means 21a. These corrected measurement values shown in the measurement results are values obtained when the simulated load as the actual load 6 is an R load with a pure resistance with a power factor of 1.0, such as a hair dryer, and a C load with a capacitor with a power factor of 0.0, such as a leading-phase capacitor.

To identify the connection state of the wiring connected to the electronic power meter 2, the corrected measurement values of the 1-side active power value W1 [W] and the 1-side reactive power value var1 [var], the corrected measurement values of the 3-side active power value W3 [W] and the 3-side reactive power value var3 [var], the voltage measurement values of the 1-side voltage V1 and the 3-side voltage V3, and the voltage phase difference θp1-p3, which are shown in the measurement results, are referenced. In other words, the combined active power value ΣW [W] and the combined reactive power value Σvar [var] are not referenced when identifying the connection state of the wiring.

The table shown in the upper part of Fig. 3 shows a connection diagram and a connection terminal correspondence table as well as theoretical value calculation formulas and vector diagrams when the wiring connected to the electronic watt-hour meter 2 is normally connected. The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 when the wiring is normally connected are calculated using the following formulas (3-1) to (3-4) shown in the table, based on the basic data of apparent powers PI1, PI3 and phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in a table by the table creation means 25 in correspondence with the normal wiring connection.
W1=PI1cos(θ1+30°)...(3-1)
var1=PI1sin(θ1+30°)...(3-2)
W3=PI3cos(θ3-30°)...(3-3)
var3=PI3sin(θ3-30°)...(3-4)

The measurement results listed in the table when the wiring is normally connected are corrected measurement values obtained by correcting the measurement values for the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when the wiring is normally connected, using the measurement value correction means 21a. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are values closest to theoretical values (not shown) calculated using equations (3-1) to (3-4) and defined for the normal wiring connection state in the table created by the table creation means 25. Therefore, the theoretical value having the value closest to the corrected measurement value is determined from the comparison result of the comparison means 26 by the determination means 27, and the normal connection state is specified as the wiring connection state according to the determined theoretical value.

In addition, Table No. E1 in Figure 3 shows a connection diagram and a connection terminal correspondence table, as well as theoretical value calculation formulas and vector diagrams when only the voltage circuit wiring is erroneously connected. In addition to the illustrated Table No. E1, there are other tables that provide connection diagrams, connection terminal correspondence tables, theoretical value calculation formulas and vector diagrams when only the voltage circuit wiring is erroneously connected, but these are not shown in the figures.

Table No. E1 specifies the cases where there is a misconnection in the wiring connection between the VT output terminal 1u and output terminal 1v. In other words, as shown by the wiring shown in dashed lines in the connection diagram and in bold italics in the connection terminal correspondence table, the P1 terminal is misconnected to the VT output terminal 1v when it should be connected to the VT output terminal 1u, and the P2 terminal is misconnected to the VT output terminals 1u, 3u, and G (ground) when it should be connected to them.

The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in the case of this incorrect wiring connection are calculated using the following formulas (4-1) to (4-4) shown in the table, based on the basic data of the apparent powers PI1, PI3 and the phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in the table by the table creation means 25 in correspondence with the above incorrect wiring connection.
W1=PI1cos(θ1-150°)...(4-1)
var1=PI1sin(θ1-150°)...(4-2)
W3=PI3cos(θ3-30°)...(4-3)
var3=PI3sin(θ3-30°)...(4-4)

The measurement results in Table No. E1 are the corrected measurement values corrected by the measurement value correction means 21a of the measurement values for the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when there is the above-mentioned misconnection in the wiring connection between the output terminal 1u and the output terminal 1v of the VT. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the values closest to the theoretical values (not shown) calculated by the formulas (4-1) to (4-4) specified for the above-mentioned misconnection state of the wiring in the table created by the table creation means 25. Therefore, the theoretical value having the value closest to the corrected measurement value is determined from the comparison result of the comparison means 26 by the determination means 27, and the misconnection state in which there is the above-mentioned misconnection in the wiring connection between the output terminal 1u and the output terminal 1v of the VT is specified as the wiring connection state corresponding to the determined theoretical value.

Tables No. A1 and No. A2 in FIG. 4 show connection diagrams and connection terminal correspondence tables, as well as theoretical value calculation formulas and vector diagrams when only the current circuit wiring is misconnected. In addition to the illustrated tables No. A1 and No. A2, there are other tables that provide connection diagrams and connection terminal correspondence tables, as well as theoretical value calculation formulas and vector diagrams when only the current circuit wiring is misconnected, but these are not shown.

Table No. A1 specifies the case where there is an erroneous connection between the 1S terminal and the 1L terminal. That is, as shown by the broken line in the connection diagram and by the bold italic letters in the connection terminal correspondence table, the 1S terminal is erroneously connected to the output terminals 1L and G of the CT instead of the output terminal 1K, and the 1L terminal is erroneously connected to the output terminal 1K instead of the output terminals 1L and G of the CT. The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in this erroneous connection are calculated using the following formulas (5-1) to (5-4) shown in the table, based on the basic data of the apparent powers PI1, PI3 and the phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in the table by the table creation means 25 in correspondence with the above-mentioned erroneous connection of the wiring.
W1=PI1cos(θ1+210°)...(5-1)
var1=PI1sin(θ1+210°)...(5-2)
W3=PI3cos(θ3+330°)...(5-3)
var3=PI3sin(θ3+330°)...(5-4)

The measurement results in Table No. A1 are the corrected measurement values corrected by the measurement value correction means 21a of the measurement values for the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when the above-mentioned misconnection exists in the wiring connection between the 1S terminal and the 1L terminal. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the values closest to the theoretical values (not shown) calculated by the formulas (5-1) to (5-4) specified for the above-mentioned misconnection state of the wiring in the table created by the table creation means 25. Therefore, the theoretical value having the value closest to the corrected measurement value is determined from the comparison result of the comparison means 26 by the determination means 27, and the misconnection state in which the above-mentioned misconnection exists in the wiring connection between the 1S terminal and the 1L terminal is specified as the wiring connection state corresponding to the determined theoretical value.

Table No. A2 specifies the case where there is an erroneous connection in the wiring connection between the 3S terminal and the 3L terminal. That is, as shown by the wiring shown by the dashed line in the connection diagram and by the bold italic letters in the connection terminal correspondence table, the 3S terminal is erroneously connected to the output terminals 3L and G of the CT instead of being connected to the output terminal 3K of the CT, and the 3L terminal is erroneously connected to the output terminal 3K instead of being connected to the output terminals 3L and G of the CT. The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in this erroneous wiring connection are calculated using the following formulas (6-1) to (6-4) shown in the table, based on the apparent powers PI1, PI3 and the phase differences θ1, θ3, which are basic data. The theoretical values calculated by each of these formulas are stored in the table by the table creation means 25 in correspondence with the above-mentioned erroneous wiring connection.
W1=PI1cos(θ1+30°)...(6-1)
var1=PI1sin(θ1+30°)...(6-2)
W3=PI3cos(θ3+150°)...(6-3)
var3=PI3sin(θ3+150°)...(6-4)

The measurement results in Table No. A2 are the corrected measurement values obtained by correcting the measurement values of the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when the above-mentioned misconnection exists in the wiring connection between the 3S terminal and the 3L terminal, by the measurement value correcting means 21a. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the values closest to the theoretical values (not shown) calculated by the formulas (6-1) to (6-4) that are defined for the above-mentioned misconnection state of the wiring in the table created by the table creating means 25. Therefore, the theoretical value having the value closest to the corrected measurement value is determined from the comparison result of the comparing means 26 by the determining means 27, and the misconnection state in which the above-mentioned misconnection exists in the wiring connection between the 3S terminal and the 3L terminal is specified as the wiring connection state corresponding to the determined theoretical value.

Tables No. EA1 and No. EA2 in FIG. 5 and Table No. EA3 in FIG. 6 show connection diagrams and connection terminal correspondence tables as well as theoretical value calculation formulas and vector diagrams when the combination of voltage circuit wiring and current circuit wiring is incorrectly connected. In addition to the illustrated tables No. EA1, No. EA2, and No. EA3, there are other tables that provide connection diagrams, connection terminal correspondence tables, theoretical value calculation formulas, and vector diagrams when the combination is incorrectly connected, but these tables are not shown.

Table No. EA1 specifies the case where the wiring on the 1st phase side and the 3rd phase side are swapped to create a reversed phase connection state, and there is a misconnection between the P1 terminal on the 1st phase side and the P3 terminal on the 3rd phase side. That is, as shown by the wiring shown in dashed lines in the connection diagram and the bold italicized letters in the connection terminal correspondence table, the P1 terminal is misconnected to the output terminal 3v instead of the VT output terminal 1u, and the P3 terminal is misconnected to the output terminal 1u instead of the VT output terminal 3v. Due to this misconnection of the voltage circuit wiring, the 1S terminal is misconnected to the output terminal 3K instead of the CT output terminal 1K, and the 1L terminal is misconnected to the output terminals 3L and G instead of the CT output terminals 1L and G. Also, the 3S terminal is misconnected to the output terminal 1K instead of the CT output terminal 3K, and the 3L terminal is misconnected to the output terminals 1L and G instead of the CT output terminals 3L and G.

The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in the case of this incorrect wiring connection are calculated using the following formulas (7-1) to (7-4) shown in the table, based on the basic data of the apparent powers PI1, PI3 and the phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in the table by the table creation means 25 in correspondence with the above incorrect wiring connection.
W1=PI3cos(θ3-30°)...(7-1)
var1=PI3sin(θ3-30°)...(7-2)
W3=PI1cos(θ1+30°)...(7-3)
var3=PI1sin(θ1+30°)...(7-4)

The measurement results in table No. EA1 are the corrected measurement values corrected by the measurement value correction means 21a of the measurement values of the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when there is the above-mentioned misconnection in the wiring connection between the P1 terminal on the 1st phase side and the P3 terminal on the 3rd phase side. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the values closest to the theoretical values (not shown) calculated by the formulas (7-1) to (7-4) specified for the above-mentioned misconnection state of the wiring in the table created by the table creation means 25. Therefore, the theoretical value having the value closest to the corrected measurement value is determined from the comparison result of the comparison means 26 by the determination means 27, and the misconnection state in which there is the above-mentioned misconnection in the wiring connection between the P1 terminal on the 1st phase side and the P3 terminal on the 3rd phase side is specified as the wiring connection state according to the determined theoretical value.

Table No. EA2 specifies a case where the misconnection of the voltage circuit wiring specified in Table No. E1 is combined with the misconnection of the current circuit wiring specified in Table No. A1. That is, as shown by the wiring shown in dashed lines in the connection diagram and by bold italic letters in the connection terminal correspondence table, the wiring connections of the VT output terminal 1u and output terminal 1v are swapped, the P1 terminal is mistakenly connected to the VT output terminal 1v instead of the VT output terminal 1u, and the P2 terminal is mistakenly connected to the VT output terminals 1u, 3u, and G instead of the VT output terminals 1v, 3u, and G. Furthermore, the wiring connections of the 1S terminal and the 1L terminal are swapped, the 1S terminal is mistakenly connected to the CT output terminal 1K instead of the CT output terminal 1L and G, and the 1L terminal is mistakenly connected to the CT output terminal 1K instead of the CT output terminals 1L and G.

The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in the case of this incorrect wiring connection are calculated using the following formulas (8-1) to (8-4) shown in the table, based on the basic data of the apparent powers PI1, PI3 and the phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in the table by the table creation means 25 in correspondence with the above incorrect wiring connection.
W1=PI1cos(θ1+30°)...(8-1)
var1=PI1sin(θ1+30°)...(8-2)
W3=PI3cos(θ3+330°)...(8-3)
var3=PI3sin(θ3+330°)...(8-4)

The measurement results in table No. EA2 are the corrected measurement values corrected by the measurement value correction means 21a of the measurement values for the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when there is the above-mentioned erroneous connection in the wiring connection between the VT output terminal 1u and the output terminal 1v, and the wiring connection between the 1S terminal and the 1L terminal. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the same as the corrected measurement values input by the measurement value input means 21 when the wiring is normally connected as shown in FIG. 3, and are the closest values to the theoretical values (not shown) calculated by the formulas (8-1) to (8-4) specified for the above-mentioned erroneous connection state of the wiring in the table created by the table creation means 25, and at the same time, are the closest values to the theoretical values (not shown) calculated by the formulas (3-1) to (3-4) specified for the normal connection state of the wiring shown in FIG. 3.

This is because the phases of the cosine and sine on the right-hand sides of the above equations (8-3) and (8-4) are θ3+330°=θ3-30°, and the values of the active power value W3 and reactive power value var3 shown in equations (8-3) and (8-4) are the same as the values in the normal connection state shown in equations (3-3) and (3-4). Therefore, the discrimination means 27 discriminates two theoretical values that are closest to the corrected measurement value in the above-mentioned incorrect wiring connection state from the comparison results of the comparison means 26, and it becomes impossible to determine whether the wiring connection state is the above-mentioned incorrect connection state or a normal connection state.

Therefore, in this embodiment, the comparison means 26 further compares the voltage phase difference θp1-p3 input by the measurement value input means 21 when the wiring is in the above-mentioned incorrect connection state with the predetermined voltage phase difference of 300°. Note that the measurement value correction means 21a does not perform correction using the formulas (1-1) and (1-2) for the voltage phase difference θp1-p3. The discrimination means 27 further refers to the comparison result of the comparison means 26 between the voltage phase difference θp1-p3 and the predetermined voltage phase difference of 300° to identify the connection state of the wiring. If the voltage phase difference θp1-p3 does not match the predetermined voltage phase difference of 300°, the discrimination means 27 discriminates that the measurement value measured together with the voltage phase difference θp1-p3 was measured when the wiring was in an incorrect connection state.

The voltage phase difference θp1-p3 input by the measurement value input means 21 when the wiring is in a normal connection state is 300° as shown in the measurement results (see FIG. 3) listed in the table when the wiring is in a normal connection state, and coincides with the predetermined voltage phase difference of 300°. On the other hand, the voltage phase difference θp1-p3 input by the measurement value input means 21 when the wiring is in the above-mentioned erroneous connection state is 120° as shown in the measurement results listed in table No. EA2, and does not coincide with the predetermined voltage phase difference of 300°. Therefore, the measurement values of the active power values W1, W3 and the reactive power values var1, var3 measured together with the voltage phase difference θp1-p3 of 120° are determined by the determination means 27 to be those measured when the wiring is in an erroneous connection state, and the wiring connection state is identified as an erroneous connection state in which the above-mentioned erroneous connection exists in the wiring connection between the VT output terminal 1u and output terminal 1v and the wiring connection between the 1S terminal and the 1L terminal.

When checking the wiring connection state, the correction value of the measurement value input from the electronic watt-hour meter 2 by the measurement value input means 21 may be the closest value to the two theoretical values specified in the table for each misconnection state of the wiring, as described above. In this case, it may not always be possible to identify the misconnection state of the wiring by comparing the voltage phase difference θp1-p3 with the specified voltage phase difference of 300°, as in the case of the misconnection described above. However, since the voltage phase difference θp1-p3 does not match the specified voltage phase difference of 300°, it is clear that there is a misconnection in the wiring connection and that it is one of the two misconnection states corresponding to the two theoretical values for which the corrected measurement value is the closest value. Therefore, in such a case, it is necessary to investigate and check the wiring state by focusing on the two misconnection states.

Table No. EA3 shown in FIG. 6 specifies a case where there is a misconnection that combines the misconnection of the voltage circuit wiring specified in Table No. E1 and the misconnection of the current circuit wiring specified in Table No. A2. That is, as shown by the wiring shown in dashed lines in the connection diagram and the bold italicized letters in the connection terminal correspondence table, the wiring connections between the output terminals 1u and 1v of the VT are swapped, the P1 terminal is misconnected to the output terminal 1v instead of the VT output terminal 1u, and the P2 terminal is misconnected to the output terminals 1u, 3u, and G instead of the VT output terminals 1v, 3u, and G. Furthermore, the wiring connections between the 3S terminal and the 3L terminal are swapped, the 3S terminal is misconnected to the output terminals 3L and G instead of the CT output terminal 3K, and the 3L terminal is misconnected to the output terminal 3K instead of the CT output terminals 3L and G.

The theoretical values of the active power values W1, W3 and the reactive power values var1, var3 in the case of this incorrect wiring connection are calculated using the following formulas (9-1) to (9-4) shown in the table, based on the basic data of the apparent powers PI1, PI3 and the phase differences θ1, θ3. The theoretical values calculated by these formulas are stored in the table by the table creation means 25 in correspondence with the above incorrect wiring connection.
W1=PI1cos(θ1+210°)...(9-1)
var1=PI1sin(θ1+210°)...(9-2)
W3=PI3cos(θ3+150°)...(9-3)
var3=PI3sin(θ3+150°)...(9-4)

The measurement results in table No. EA3 are corrected measurement values obtained by correcting the measurement values of the actual load 6 input from the electronic watt-hour meter 2 by the measurement value input means 21 when there is the above-mentioned misconnection in the wiring connection between the output terminal 1u and the output terminal 1v of the VT and the wiring connection between the 3S terminal and the 3L terminal by the measurement value correcting means 21a. The corrected measurement values of the active power values W1, W3 and the reactive power values var1, var3 are the values closest to the theoretical values (not shown) calculated by the formulas (9-1) to (9-4) specified for the above-mentioned misconnection state of the wiring in the table created by the table creating means 25. Therefore, the determining means 27 determines the theoretical value having the value closest to the corrected measurement value from the comparison result of the comparing means 26, and the misconnection state in which there is the above-mentioned misconnection in the wiring connection between the output terminal 1u and the output terminal 1v of the VT and the wiring connection between the 3S terminal and the 3L terminal is specified as the wiring connection state according to the determined theoretical value.

According to the computer program for determining the wiring connection state of the electronic watt-hour meter 2 according to this embodiment, as described above, for each of two predetermined pairs of phases of the three-phase power source, the active power values W1, W3 and the reactive power values var1, var3 are input as measured values from the electronic watt-hour meter 2 to the PC 1 by the measured value input means 21, and the interphase voltages P1, P3 are input as voltage measurements. Then, the measured values of the active power values W1, W3 and the reactive power values var1, var3 input by the measured value input means 21 are corrected to corrected measured values corresponding to the rated voltage value VR of the electronic watt-hour meter 2 by the measured value correction means 21a using the formulas (1-1) and (1-2) based on the voltage measurements input by the measured value input means 21. The comparison means 26 compares the corrected measured values corrected by the measured value correction means 21a with the theoretical values defined in the table created by the table creation means 25. In the discrimination means 27, the theoretical value having the closest value to the corrected measured value is discriminated from the comparison result of the comparison means 26, and the connection state of the wiring connected to the terminal portion 2b when the electronic watt-hour meter 2 was installed is identified according to the discriminated theoretical value.

Therefore, by having the PC 1 execute a program that causes the computer to function as each of the above means, the measurement value that is compared with the theoretical value based on the calculation of the rated voltage value VR of the electronic watt-hour meter 2 becomes a corrected measurement value corresponding to the rated voltage value VR of the electronic watt-hour meter 2. This makes it possible to accurately determine the connection state of the wiring connected to the electronic watt-hour meter 2 without being affected by voltage fluctuations at the installation site of the electronic watt-hour meter 2.

In this embodiment, when determining the connection state of the wiring connected to the electronic watt-hour meter 2, in order to eliminate the influence of voltage fluctuations at the installation site of the electronic watt-hour meter 2, the measurement value input from the electronic watt-hour meter 2 by the measurement value input means 21 is corrected by the measurement value correction means 21a as described above. It is also possible to apply correction to the theoretical value calculated by the theoretical value calculation means 24, rather than the measurement value input by the measurement value input means 21. However, applying correction to the theoretical value calculated by the theoretical value calculation means 24 causes the following inconvenience.

For example, when connecting each wire of a three-phase power supply to the P1, P2, and P3 terminals, if a misconnection is assumed in which the wires on side 1 of the three-phase power supply are swapped with the wires on side 3, the measurement value of the phase-to-phase voltage input to the terminal on side 1 of the electronic watt-hour meter 2 will be mistakenly treated as the measurement value of the phase-to-phase voltage on side 1 by PC1, when it should actually be treated as the measurement value of the phase-to-phase voltage on side 3. Therefore, if a correction is applied to the theoretical value, an erroneous correction using the measurement value of the phase-to-phase voltage on side 3 will be applied to the theoretical value of the phase-to-phase voltage on side 1.

In contrast, in the present embodiment, when a correction is applied to the measurement value input by the measurement value input means 21, even if the above-mentioned incorrect connection occurs, the measurement value of the phase-to-phase voltage input to the 1-side terminal of the electronic watt-hour meter 2 is mistakenly treated as the measurement value of the phase-to-phase voltage on the 1-side by PC1, even though it should be treated as the measurement value of the phase-to-phase voltage on the 3-side. However, the correction is applied to the measurement value of the phase-to-phase voltage on the 3-side that is mistakenly treated as the measurement value of the phase-to-phase voltage on the 1-side. Therefore, when a correction is applied to the measurement value, no discrepancy occurs between the actual phase (phase on the 3-side) input to the 1-side terminal of the electronic watt-hour meter 2 and the phase (phase on the 3-side) to which the correction is applied by PC1. Therefore, according to this embodiment, it is possible to apply a correct correction to the phase-to-phase voltage.

In addition, according to the computer program for determining the wiring connection state of the electronic watt-hour meter 2 in this embodiment, the voltage phase difference θp1-p3 between two predetermined pairs of interphase voltages P1, P3 input from the electronic watt-hour meter 2 by the measurement value input means 21 is further compared by the comparison means 26 with a predetermined voltage phase difference of 300°. The wiring connection state is identified by further referring to the comparison result by the discrimination means 27. Therefore, the wiring connection state that cannot be determined only by comparing the theoretical value with the corrected measurement value can be identified, and it becomes possible to determine the wiring connection state with higher accuracy.

In the above embodiment, the electronic watt-hour meter 2 is a three-phase, three-wire type, but the present invention can be applied to single-phase, two-wire and single-phase, three-wire electronic watt-hour meters in the same manner. The measurement value in the case of a single-phase, two-wire electronic watt-hour meter can be corrected using formula (1-1).

In addition, in the case of a single-phase three-wire electronic watt-hour meter, the measurement values can be corrected using the following formulas, dividing them into the following cases: In other words, when the measurement value of phase 1 voltage P1 between terminals P1 and P2 is 70 [V] to 130 [V], the corrected measurement values of active power value W1 and reactive power value var1 are calculated using the following formula (10-1), with rated voltage value VR = 100 [V].
Corrected measurement value (W1, var1) = Measurement value (W1, var1) × (100/P1) ² … (10-1)

Furthermore, if the measured value of phase 1 voltage P1 between the P1 and P2 terminals is between 140 [V] and 260 [V], it is recognized as an incorrect connection in which a 1-phase/3-phase voltage is applied between the P1 and P2 terminals, and the corrected measured values of the active power value W1 and reactive power value var1 are calculated using the following formula (10-2) with the rated voltage value VR = 200 [V].
Corrected measurement value (W1, var1) = measurement value (W1, var1) × (200/P1) ² … (10-2)

Furthermore, if the measured value of the phase 1 voltage P1 between the P1 terminal and the P2 terminal is other than 70 [V] to 130 [V] or 140 [V] to 260 [V], and if the measured value of the voltage P1 is zero because the wiring is not connected to the P1 terminal or the P2 terminal, etc., and the calculation of formula (10-1) or (10-2) cannot be performed, the measurement value correction means 21a will not perform correction processing, as shown in the following formula (10-3).
Corrected measured value (W1, var1) = measured value (W1, var1) ... (10-3)

In addition, when the measurement value of the phase 3 voltage P3 between the P3 terminal and the P2 terminal is 70 [V] to 130 [V], the corrected measurement values of the active power value W3 and the reactive power value var3 are calculated using the following formula (11-1) with the rated voltage value VR = 100 [V].
Corrected measurement value (W3, var3) = measurement value (W3, var3) × (100/P3) ² ... (11-1)

Furthermore, if the measured value of the phase 3 voltage P3 between the P3 terminals and the P2 terminals is between 140 [V] and 260 [V], it is recognized as an incorrect connection in which the voltage between phase 1 and phase 3 is applied between the P3 terminals and the P2 terminals, and the corrected measured values of the active power value W3 and reactive power value var3 are calculated using the following formula (11-2) with the rated voltage value VR = 200 [V].
Corrected measurement value (W3, var3) = measurement value (W3, var3) × (200/P3) ² … (11-2)

Furthermore, if the measured value of the phase 3 voltage P3 between the P3 terminal and the P2 terminal is other than 70 [V] to 130 [V] or 140 [V] to 260 [V], and if the measured value of the voltage P3 is zero because the wiring is not connected to the P3 terminal or the P2 terminal, etc., and the calculation of equation (11-1) or (11-2) cannot be performed, then the measurement value correction means 21a will not perform correction processing, as shown in the following equation (11-3).
Corrected measured value (W3, var3) = measured value (W3, var3) ... (11-3)

In the above embodiment, the basic data acquisition means 23 has acquired the apparent power values PI1, PI3 and the phase differences θ1, θ3 as basic data, which are determined based on the rated capacity and phase angle of the simulated load 3 input to the load value input means 22. However, the basic data acquisition means 23 may be configured to calculate and acquire the basic data from the corrected measurement values of the simulated load 3 or the actual load 6 input by the measurement value input means 21 and corrected by the measurement value correction means 21a.

In this case, the basic data acquiring means 23 calculates basic data of apparent power values PI1, PI3 and phase differences θ1, θ3 between each of two predetermined pairs of phases from the 1-side and 3-side active power values W1, W3 and the 1-side and 3-side reactive power values var1, var3 measured by the electronic watt-hour meter 2 and corrected by the measurement value correcting means 21a as follows: That is, the basic data of the apparent power values PI1, PI3 are calculated from the corrected measurement values by the following equations (12-1) and (12-2).
PI1=(W1 ² +var1 ² ) ^1/2 ...(12-1)
PI3=(W3 ² +var3 ² ) ^1/2 ...(12-2)

In addition, basic data for each of the phase differences θ1, θ3 is calculated from the following equations (13-1) and (13-2) using the corrected measurement values corrected by the measurement value correcting means 21a, taking into account a phase shift of 30° in the three-phase, three-wire system.
θ1=cos ^-1 (W1/PI1) -30°...(13-1)
θ3=cos ^-1 (W3/PI3)+30°...(13-2)

However, when the signs of var1 and var3 measured by the electronic power meter 2 are - (minus), the basic data of each phase difference θ1 and θ3 are calculated from the following equations (14-1) and (14-2) using the corrected measurement values corrected by the measurement value correction means 21a.
θ1=-cos ^-1 (W1/PI1)-30°...(14-1)
θ3=-cos ^-1 (W3/PI3)+30°...(14-2)

According to this configuration, the basic data is acquired by calculation of the basic data acquisition means 23 from the corrected measurement value of the simulated load 3 or the actual load 6 corrected by the measurement value correction means 21a. According to this configuration, this basic data is a value corresponding to the rated voltage value VR of the electronic watt-hour meter 2. Therefore, according to this configuration, the corrected measurement value corrected by the measurement value correction means 21a is compared with the theoretical value defined in the table created by the table creation means 25, thereby achieving the same effect as the above embodiment.

1...Personal computer (PC)
2...Electronic power meter 2a...Display part 2b...Terminal part 3...Simulated load 4...Sensor 5...Cable 6...Actual load 11...ROM
12...RAM
13. CPU

Claims (2)

Computer,
an information input means for inputting a phase wire system and a rated voltage value of the electronic watt-hour meter as meter information; and, when the phase wire system of the electronic watt-hour meter input by said information input means is a single-phase three-wire system, a measurement value input means for inputting active power values and reactive power values measured by the electronic watt-hour meter for each interphase between a neutral line and each voltage line of a three-wire single-phase power source as measurement values, and interphase voltages of 70 [V] to 130 [V] or 140 [V] to 260 [V] between said each phase as voltage measurement values; a measurement value correcting means for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 100[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 70[V] to 130[V], and for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 200[V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 140[V] to 260[V]; a load value input means for inputting a rated capacity and a phase angle of a dummy load to be connected to the electronic watt-hour meter; a theoretical value calculation means for calculating, as theoretical values, the active power value and the reactive power value for each of the phases in each connection state of wiring connected to the electronic watt-hour meter from the basic data obtained by the basic data acquisition means; a table creation means for creating a table that specifies the relationship between the theoretical value calculated by the theoretical value calculation means and each connection state of the wiring; a comparison means for comparing the corrected measurement value of the value corrected by the measurement value correction means with the theoretical value specified in the table created by the table creation means; and a wiring connection state determination program for causing the electronic watt-hour meter to function as a determination means that determines the theoretical value having a value closest to the corrected measurement value from the comparison result of the comparison means, and specifies the connection state of the wiring according to the determined theoretical value. Computer,
An information input means for inputting a phase wire system and a rated voltage value of an electronic watt-hour meter provided separately from the computer as meter information, and when the phase wire system of the electronic watt-hour meter input by the information input means is a single-phase three-wire system, the phase-to-phase voltage of 70 [V] to 130 [V] or 140 [V] to 260 [V] between each of the phases is measured by the electronic watt-hour meter for each phase between the neutral line and each voltage line of a three-wire single-phase power source and the active power value and reactive power value output from the external communication port of the electronic watt-hour meter as the measurement value. a measurement value input means for inputting a voltage measurement value from the external communication port via a sensor; a measurement value correction means for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 100 [V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 70 [V] to 130 [V], and for correcting the measurement value to a corrected measurement value corresponding to a rated voltage value of 200 [V] of the electronic watt-hour meter based on the voltage measurement value when the phase-to-phase voltage is 140 [V] to 260 [V]; and a theoretical value calculation means for calculating, from the basic data acquired by the basic data acquisition means, the active power value and the reactive power value between each of the phases in each connection state, including a normal connection state and an erroneous connection state, of the wiring connected to the terminal portion of the electronic watt-hour meter; a table creation means for creating a table that specifies the relationship between the theoretical value calculated by the theoretical value calculation means and each of the connection states of the wiring; a comparison means for comparing the corrected measurement value of the value corrected by the measurement value correction means with the theoretical value specified in the table created by the table creation means; and a wiring connection state determination program for an electronic watt-hour meter, which functions as a determination means for determining, from a comparison result of the comparison means, the theoretical value having a value closest to the corrected measurement value, and specifying, in accordance with the determined theoretical value, the connection state of the wiring connected to the terminal portion when the electronic watt-hour meter is installed, as either a normal connection state or an erroneous connection state.