JP3003932B1 - Connection determination device for watt hour meter - Google Patents

Abstract

Abstract: Provided is a connection determination device for a watt hour meter that can reliably determine whether a connection state from a power supply line side is correct for various watt hour meters corresponding to different power supply methods. SOLUTION: A phase difference between a voltage and a current supplied to a watt-hour meter 104 is detected via a connection unit 1, and when the phase difference is within a specified value, a determination unit 2 determines that the connection is correct. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection determination device for a watt-hour meter used for determining whether or not a connection state from a power supply line to a watt-hour meter used with a low-voltage transformer is correct. .

[0002]

2. Description of the Related Art Heretofore, a watt hour meter has been used which is used together with a low-voltage transformer attached to a power supply line and integrates and measures the consumption of AC power supplied via the power supply line. Such a watt-hour meter is, for example, as shown in FIG. 26, when a single-phase three-wire power supply is performed.
A voltage generated in the power supply lines 101, 102, 103 is detected via a voltage detection terminal 107 connected to the power supply lines 101, 102, 103, and the power supply lines 101, 1
02, 103 via the current detection terminal 108 connected to the transformers 105, 106.
The current supplied from 1, 102, 103 is detected. The low-voltage transformers 105 and 106 are connected to power supply lines 101 and 10.
2 and 103 are housed in a storage box 109 which covers a part of them. The watt-hour meter 104 measures power consumption based on the detected voltage and current, and displays the integrated value on the numerical value display unit 110.

[0003]

As described above, in a watt-hour meter used with a low-voltage transformer, a voltage detection terminal and a current detection terminal of the watt-hour meter are provided.
If the power supply line is not correctly connected, correct power consumption cannot be measured. Conventionally, there is no judging device that can reliably judge whether or not the connection state of such a watt hour meter is successful. Of course, the connection state of the watt hour meter may be determined based on the phase sequence of voltage and current. However, in the case of three-phase three-wire power supply, single-phase three-wire power supply, or single-phase two-wire power supply, Even if the phase sequence is normal, the metering of the watt hour meter may be abnormal, and it is not possible to reliably determine whether the connection state is successful.

In view of the above, the present invention has been proposed in view of the above-mentioned conventional circumstances, and the success or failure of the connection state from the power supply line to the watt hour meter used with the low-voltage transformer is determined by the live state. It is an object of the present invention to provide a watt-hour connection determination device that can easily and reliably determine the power consumption of the watt-hour meter and can measure the power consumption normally.

[0005]

In order to achieve the above-mentioned object, the present invention focuses on a phase difference between a voltage applied to a terminal of a watt-hour meter and a current supplied to the terminal. It is. That is, the first invention (the invention according to claim 1) includes a connection portion connected to a terminal portion of a watt hour meter that integrates and measures power consumption of AC power supplied via a power supply line; Via the connection, the voltage applied to the terminal of the watt-hour meter from the power supply line and the current supplied to the terminal of the watt-hour meter from the low-voltage transformer attached to the power supply line are detected. A phase detector that compares the phase difference between the voltage and the current detected by the detector, and determines whether the phase difference between the voltage and the current detected by the phase comparator is within a specified value. A determination unit for determining whether the connection from the power supply line to the terminal of the watt-hour meter is correct when the phase difference is within a specified value, and a display unit for displaying a determination result by the determination unit And characterized in that:

Further, the second invention (the invention according to claim 2)
According to the first aspect of the present invention, in the first aspect of the present invention, the determination by the determination unit and the display by the display unit are configured to be performed for each circuit constituting the watt hour meter.

[0007] The phase difference between the voltage and the current supplied from the power supply line is determined by the power supply method (phase power type) supported by the watt hour meter and the power factor of the load. for that reason,
If the power meter and power factor supported by the wattmeter can be specified,
The specified value of the phase difference between the voltage and the current at the time of normal connection can be set. For example, in the case of a watt hour meter corresponding to single-phase two-wire power supply and the load power factor is 1 (100%),
When a normal connection is made, the phase difference between the voltage and the current is 0 degree, and when the load power factor is 0.5 (50%), it is 60 degrees. In this case, when an abnormal connection in which the connection of the current circuit is reversed is made, the load power factor becomes (100%).
In the above case, the phase difference between the voltage and the current is 180 degrees, and when the load power factor is 0.5 (50%), it is 120 degrees. Usually, the load power factor is 1 (100%) to 0.5.
(50%), the specified value of the phase difference between the voltage and the current is specified as 0 to 60 degrees, and a normal connection is made depending on whether the phase difference is within the specified value range. Can be determined.

As described above, in this connection determination device for a watt hour meter, the specified value of the phase difference between the voltage and the current is set for each power supply system corresponding to the watt hour meter, and the terminal portion of the watt hour meter is set. The phase difference between the voltage and the current is detected, and if the phase difference is within a specified value, it is determined that the connection is normal, and if it is other than the specified value, it is determined that the connection is abnormal. The third invention (the invention according to claim 3) includes a changeover switch for selecting a power supply method using a power supply line in order to support various watthour meters corresponding to different power supply methods, and the determination unit includes: The judgment contents are switched according to the switching state of the changeover switch.

This watt-hour meter connection discriminating apparatus is composed of a main body having a detection section, a phase comparison section, a judgment section and a display section, and a connection section connected to a terminal section of the watt-hour meter. The connecting portion is connected to the main body portion via a connector, and can be replaced in accordance with a power supply system supported by the watt hour meter. For example, the connection part of the watt-hour meter corresponding to the single-phase two-wire power supply has four contacts according to the number of terminals of the watt-hour meter, and provides a single-phase three-wire power supply and a three-phase three-wire power supply. The connection part of the watt hour meter corresponding to the above has a structure having seven contacts.

Further, in this watt-hour meter judging device, when it is judged that the connection state between the power supply line side and the watt-hour meter side is normal, a display meaning "good" is displayed on the display unit, When the connection state is determined to be abnormal, the display unit displays an indication indicating “No”. If no voltage and current are supplied, or if the voltage and current values are extremely small and phase comparison cannot be performed, a display meaning "impossible" can be performed. As the display, for example,
The display meaning "good" can be "green light", the display meaning "fail" can be "red light", the display meaning "improper" can be "yellow light", and the like.

[0011] In this connection determination device for a watt hour meter, the determination by the determination unit and the display by the display unit are performed for each circuit constituting the watt hour meter. For example, in a watt-hour meter compatible with single-phase three-wire power supply and a watt-hour meter compatible with three-phase three-wire power supply, there are two sets of voltage and current circuits. , And display is performed for each circuit. In this way, the display is performed by the display unit for each circuit, so that it is clear at a glance which circuit has an abnormal connection. Further, when the watt hour meter is compatible with three-phase power supply, the determination unit also determines the phase sequence of the connection from the power supply line to the terminal of the watt hour meter. Invention).

Further, in a watt hour meter compatible with single-phase three-wire power supply, even in abnormal connection, the phase difference between the voltage and the current may be the same as in the normal connection state. In order to cope with such a state, in the connection determination device for the watt hour meter, not only the phase comparison between the voltage and the current, but also a transmitter is connected to one secondary terminal of the two low-voltage transformers. The discrimination signal transmitted by this transmitter is connected to the secondary terminal, and the presence / absence of this discrimination signal can be used as a judgment material for judging the connection state, together with the result of the phase comparison. (The invention according to claim 5). That is, the determination unit detects the presence / absence of a determination signal generated by the transmission circuit via the connection unit at the terminal of the wattmeter, and determines the presence / absence of the determination signal together with the phase difference between the voltage and the current in the connection state. To determine the success or failure of For example, when the discrimination signal is injected into one of the low-voltage transformers, the determination unit determines that the phase difference between the voltage and the current is within a specified value, and that one of the terminals of the watt hour meter has a low-voltage transformer. Only when a discrimination signal is detected at the current terminal corresponding to the device, it is determined that the connection is normal.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, a watt hour meter connection determination device according to this embodiment includes a watt hour meter 104 that integrates and measures the power consumption of AC power supplied through power supply lines 101, 102, and 103. And a main unit 2 to which the connection unit 1 is connected via a connector.

The main body 2 is attached to the support plate 104a of the watt-hour meter 104 by the clamper 2a only when determining the correctness of the connection state. In addition, the connection unit 1
Can be replaced in accordance with the power supply system corresponding to the watt hour meter 104 whose connection state with the power supply lines 101, 102, 103 is to be determined. For example, a connection unit used for a watt hour meter compatible with single-phase two-wire power supply has four contacts according to the number of terminals of the terminal unit of the watt hour meter, and has a single-phase three-wire type.
As shown in FIG. 4, the connection unit used for the watt hour meter compatible with the wire feed and the three-phase three-wire feed has seven connectors 3.

As shown in FIGS. 2 and 8, the connection portion 1 is connected between the voltage detection terminals P1 and P2 of the terminal portion of the watt hour meter and between P2 and P3 by a voltage dividing resistor 4 in the connection portion 1. The voltage between the two is divided to about 2 V and output to the main body 2 as a voltage detection signal. Further, the connection part 1 is a current terminal 1
The voltage generated between S and 1L and between 3S and 3L is output as a current detection signal to the main body 2 via the protection resistor 5. Here, a case will be described in which a watt hour meter compatible with single-phase three-wire power supply is used. Also,
In the connection portion 1 for detecting the voltage and the current, each contact 3 can be moved forward and backward with respect to the housing 1a of the connection portion 1 as shown by an arrow A in FIG. It is elastically biased in the direction. In addition, these contacts 3
Are independently movable with respect to the housing 1a independently of the contacts 3, and are respectively covered by insulating covers 3a integrally provided. These insulating covers 3a are elastically urged in a direction to protrude forward by coil springs 3b, 3b disposed between these insulating covers 3a and the housing 1a.

The housing 1a includes a pair of fixing screws 1
b, 1b, it is attached to the watt-hour meter 104. As shown in FIG. 26, screw holes 111, 111 are provided in the terminal portion of the wattmeter 104. These screw holes 111, 111 are for screwing a terminal cover (not shown). The terminal cover is removed, and as shown in FIG.
Is screwed in to fix the connecting portion 1. At this time, as the fixing screws 1b, 1b are screwed into the screw holes 111, the housing 1a approaches the watt-hour meter 104, and the insulating cover 3a comes into contact with the front surface of the watt-hour meter 104 and stops. As a result, the housing 1a and the insulating cover 3a approach each other against the urging force of the coil springs 3b, 3b, and each contact 3 projects forward from the insulating cover 3a. Are in contact with the terminals 107 and 108 of the terminal of the watt hour meter 104. In this way, in this contact portion 1, work safety when connecting to the terminal portion of the watt hour meter is ensured.

As shown in FIG. 8, the main unit 2 has a built-in detection unit 6, a microcomputer 7 serving as a phase comparison unit and a discrimination unit, and a display unit 8. As shown in FIG. 9A, the detection signals of the current and the voltage input to the main body 2 pass through the phase-corrected amplifier circuit 6a in the detection unit 6 and are used as level determination signals as shown in FIG. Are input to the microcomputer 7. Also,
The signal amplified by the amplifying circuit 6a is
The waveform is converted into a rectangular wave by b, and is input to the microcomputer 7 as a phase comparison signal as shown in FIG. Further, the current and voltage detection signals are input to the microcomputer 7 via the signal detection circuit 6c.
In this way, the detecting unit 6 determines the voltage applied to the terminal of the watt hour meter 104 from the power supply lines 101, 102, 103 via the connection unit 1 and the power supply lines 101, 102, 1
A current supplied by the power supply lines 101, 102, and 103 is detected via low-voltage transformers 105 and 106 attached to the power supply line 03. The microcomputer 7 detects a phase difference between a voltage and a current based on a signal transmitted from the detection unit 6 as a phase comparison unit. Further, the microcomputer 7 determines whether or not the phase difference between the detected voltage and the detected current is within a specified value. It is determined that the connection of the watt hour meter 104 to the terminal is correct. The microcomputer 7 and each circuit are driven by being supplied with power from a battery 9 built in the main body 2.

The connection determination device for the watt hour meter includes:
A changeover switch 10 for selecting a power supply method by a power supply line is provided in order to support various watthour meters corresponding to different power supply methods. This changeover switch 10
As shown in FIGS. 3 and 6, “off”, “test”,
It has switching positions of “single-phase two-wire 100V”, “single-phase two-wire 200V”, “single-phase three-wire 100V”, and “three-phase three-wire 200V”. The microcomputer 7 switches the content of the determination according to the switching state of the changeover switch 10. That is, the feeder lines 101, 102, 103
The phase difference between the voltage and the current supplied by the
04 is determined by the corresponding power supply method (phase line method) and the power factor of the load. Therefore, when the power supply method and the power factor corresponding to the watt hour meter 104 are specified, the specified value of the phase difference between the voltage and the current in the normal connection can be set. For example, in the case of a watt hour meter compatible with single-phase two-wire power supply (100 V, 200 V) and a load power factor of 1 (100%), if normal connection is made, FIG.
In (a), the phase difference between the voltage V and the current I is ± 0 degrees, and the load power factor is 0.5 (5).
0%), the phase difference between the voltage V and the current I ′ + plus 6
0 degrees. In this case, when an abnormal connection in which the connection of the current circuit is reversed is made, as shown by (b) in FIG. 12, when the load power factor is 1 (100%), the order of the voltage V and the current I is changed. The phase difference is minus 180 degrees, and when the load power factor is 0.5 (50%), the voltage V and the current I '
Is -120 degrees. Normally, the load power factor is in the range of 1 (100%) to 0.5 (50%). Therefore, the specified value of the phase difference between the voltage and the current is specified as 0 to 60 degrees. Whether or not the normal connection is established can be determined based on whether or not the phase difference is within the range of the specified value.

Similarly, if the watt hour meter is a single-phase three-wire power supply (100 V) and the load power factor is 1 (100%), and the normal connection is made, the figure is As shown in FIG. 13A, the phase difference between the voltages V1 and V2 and the currents I1 and I2 is plus or minus 0 degree, and when the load power factor is 0.5 (50%), the voltage V1 , V2 and the currents I1 'and I2' are each minus 60 degrees. In this case, when an abnormal connection in which the connection of the current circuit is reversed is made, as shown in FIG. 13B, when the load power factor is 1 (100%), the voltages V1, V2 and the current I1 are set. , I2 are each minus 180 degrees, and the load power factor is 0.
5 (50%), the voltages V1 and V2 and the current I1 ',
The phase difference from I2 'is minus 120 degrees.

FIG. 1 shows a watt hour meter which is compatible with three-phase three-wire power supply (200 V) and has a load power factor of 1 (100%) and normal connection.
4, the phase difference between the voltages V1 and V2 and the currents I1 and I2 is plus 30 degrees and minus 30 degrees.
When the load power factor is 0.5 (50%), the phase difference between the voltages V1 and V2 and the currents I1 'and I2' is 90
Degrees, 30 degrees. In this case, when the abnormal connection is made, as shown by (b) in FIG. 14, when the load power factor is 1 (100%), the phase difference between the voltages V1, V2 and the currents I1, I2 is positive. 120 degrees, minus 1
When the load power factor is 0.5 (50%), the phase difference between the voltages V1 and V2 and the currents I1 'and I2' is minus 60 degrees and plus 150 degrees. As described above, in this watt-hour meter connection determination device, the specified value of the phase difference between the voltage and the current is set for each power supply method corresponding to the watt-hour meter, and the voltage at the terminal of the watt-hour meter is set. The microcomputer 7 detects a phase difference between the current and the current, and if the phase difference is within a specified value, the microcomputer 7 determines that the connection is normal. Otherwise, the microcomputer 7 determines that the connection is abnormal.

Then, as shown in FIG. 8, a display section 8 built in the main body section 2 displays the judgment result by the microcomputer 7. That is, in this watt-hour meter connection determination device, when the connection state between the power supply line side and the watt-hour meter is normally performed, a display meaning “good” is displayed on the display unit 8. When the connection state is determined to be abnormal, the display unit 8 displays a message indicating “No”. If no voltage and current are supplied from the power supply line, or if the voltage and current values are extremely small and the phase comparison cannot be performed, a display meaning "impossible" is displayed.
As shown in FIG. 3, the display on the display unit 8 indicates that “good” is indicated by green LED (light emitting diode) (G1, G2, G3, G4) lighting, and “no”.
Is a red LED (R1, R2, R3, R3
4) Lighting, LED indicating "impossible" is yellow LED
(Y1, Y2, Y3, Y4) are turned on. That is, the microcomputer 7 determines “good”, “bad” or “impossible” based on the determination condition selected by the changeover switch 10, and as a result, a predetermined green, red or yellow LED Lights up. When the display unit 8 shown in FIG. 3 is adapted to single-phase three-wire power supply,
The LED (G1, R1, Y1) in the column indicates the state of the first voltage circuit, and the LED (G2, R2, Y2) in the second column indicates the state of the second voltage circuit.
The state of the voltage circuit of FIG.
(3, Y3) shows the state of the second current circuit, and L in the fourth column
ED (G4, R4, Y4) indicates the state of the second current circuit. When used for a watt-hour meter compatible with another power supply method, a specified value serving as a determination criterion matching each power supply method is set by switching with the changeover switch 10, and the determination and display are similarly performed. You. In addition,
When the changeover switch 10 is set to the "test" position, all the LEDs are turned on to confirm the lighting state of the LEDs.

Here, the conditions for judging "good" by the microcomputer 7 are as follows for a single-phase three-wire power supply, for example. (1) Between P1, P2 and P2
The voltage between P3 is 100V ± 15V. (2) Voltage between 1S and 1L and between 3S and 3L is 25m
V to 375 mV. (3) The current phases of 1S and 1L with respect to the voltage between P1 and P2 are 0 degrees to 60 degrees delayed. (4) The current phase of 3S, 3L with respect to the voltage between P2 and P3 is 0 degree to 60 degrees delayed. (5) P
The potential phase difference between P1, P2 and P2, P3 is 180 degrees plus or minus 20 degrees. The microcomputer 7 determines that the voltage between P1 and P2 and between P2 and P3 is 15 V or less, and that the voltage between 1S and 3L is 25 mV.
In the following cases, “impossible” is determined. Further, the microcomputer 7 makes a determination of “No” when each voltage is out of the determination criteria of “good” and “improper”, and when each phase is out of the determination criteria of “good”.

Further, in this watt-hour meter connection determination apparatus, the determination by the microcomputer 7 and the display by the display unit 8 are performed for each circuit constituting the watt-hour meter.
For example, in a watt-hour meter compatible with single-phase three-wire power supply and a watt-hour meter compatible with three-phase three-wire power supply, there are two sets of voltage and current circuits. , Judgment and display for each circuit. As described above, in the connection determination device for the watt hour meter, the display on the display unit 8 is performed for each circuit, so that it is possible to clearly determine which circuit has abnormal connection.

Further, as described above, in a watt hour meter compatible with single-phase three-wire power supply, even when abnormal connection is established, when the phase difference between voltage and current is normal, the same state is obtained. There are cases. In order to cope with such a state, in this watt-hour connection determination device, not only the phase comparison between the voltage and the current but also the two low-voltage transformers 105 and 106 as shown in FIG. A transmitter 11 is connected to one of the secondary terminals, and a discrimination signal transmitted from the transmitter 11 is injected into the secondary terminal.
It can be used as a judgment material for judging the connection state in combination with the result of the phase comparison. As shown in FIG. 7, the transmitter 11 has clampers 11a and 11b on both sides, and is attached to the storage box 109 by these clampers 11a and 11b. When the power switch 12 is turned on, the transmitter 11 outputs a determination signal from the output terminals 15 and 16. These output terminals 15 and 16 are formed in a clip shape and are connected to secondary terminals of the low-voltage transformer.
The transmitter 11 is provided with a pilot lamp 13 and a monitor sound generator 14, and the operator can confirm that the discrimination signal is transmitted by the pilot lamp 13 and the monitor sound generator 14. it can. Further, as shown in FIG. 10, the transmitter 11 has a transmission circuit 17, and outputs a discrimination signal transmitted from the transmission circuit 17.
The signal is sent to output terminals 15 and 16 via a waveform shaping circuit 18 and an injection circuit 19. These transmitting circuit 17, waveform shaping circuit 18 and injection circuit 19 are driven by being supplied with power from a battery 20. The discrimination signal transmitted by the transmission circuit 17 is, for example, a sawtooth wave having a constant period as shown in FIG.
The power is passed through the connection from the power supply line to the watt-hour meter and is input to the watt-hour meter connection determination device. Then, as shown in FIG. 8, the discrimination signal is input to the microcomputer 7 via the signal detection circuit 6c as a discrimination signal shown by (c) in FIG. When the current detection signal between the terminals 1S and 1L includes the discrimination signal injected from the transmitter 11, the signal detection circuit 6c inputs an "H" level signal to the microcomputer 7, If there is no discrimination signal, an "L" level signal is input. And
The microcomputer 7 checks the presence or absence of the discrimination signal transmitted by the transmitter 11 at the terminal of the watt hour meter at the connection unit 1.
And the presence or absence of this determination signal, together with the phase difference between the voltage and the current, can be used as a material for determining whether or not the connection state is correct.

For example, when the discriminating signal is injected into one of the low-voltage transformers 105 by the transmitter 11, the microcomputer 7 determines that the phase difference between the voltage and the current is within a specified range and the power meter It is determined that the connection state is normal only when a determination signal is detected at one of the current terminals corresponding to the low-voltage transformer 105 among the terminal portions. In the case where the determination signal is injected by the transmitter 11 as described above, the conditions under which the microcomputer 7 determines "good" are as follows. (1) The voltage between P1 and P2 and between P2 and P3 is 100V ± 15V
That. (2) The voltage between 1S and 1L and between 3S and 3L is 25 mV to 375 mV. (3) P1,
The current phase of 1S, 1L is 0 degree to 60 with respect to the voltage between P2.
Degree. (4) 3S, 3 for the voltage between P2 and P3
The current phase between L is 0 degree to 60 degrees delayed.
(5) The voltage phase difference between P1 and P2 and between P2 and P3 is 1
80 degrees plus or minus 20 degrees. (6) There is a discrimination signal from the transmitter 11 between the current terminals 1S and 1L. Then, the microcomputer 7 calculates P1, P
If the voltage between 2 and between P2 and P3 is 15V or less, and if the voltage between 1S and 1L and between 3S and 3L is 25mV or less, the determination of "impossible" is made. Further, the microcomputer 7 makes a determination of “No” when each voltage is out of the determination criteria of “good” and “improper”, and when each phase is out of the determination criteria of “good”. When the watt hour meter is compatible with three-phase power supply, the microcomputer 7 also determines the phase sequence of the connection from the power supply line to the terminal of the watt hour meter. The judgment result of the phase order is displayed on the display unit 8 if the phase is a normal phase by a green LED (G
5) When the phase is reversed, the red LED
This is displayed by lighting (R5).

When the load current supplied from the power supply side is small, a pair of clamps CT21 and CT22 are used as shown in FIG. These clamp CT
21P22 has a coil portion that can be opened and closed in a clamp shape, and each coil portion is connected to one of the low-voltage transformers 10P22.
5 is attached to the connection connecting the secondary terminal of the power meter and the current terminal of the watt-hour meter. This pair of clamp CT
The output terminals 23, 24 of the main body 2 are connected to the detection section 6 in the main body 2 via the connection terminals of the main body 2.

The microcomputer 7 described above
Is performed according to the flowchart described below. That is, as shown in FIG. 15, when the operation is started in step st1, step s
At t2, it is determined whether the battery voltage should be checked. When the changeover switch 10 is in the "test" position, the process proceeds to step st10, where it is determined whether the battery voltage is sufficient. In step st10, if the battery voltage is sufficient, the process proceeds to step st11, where the LE of the display unit is displayed.
D is turned on, and the process returns to step st2. If the battery voltage is not sufficient, the process returns to step st2. When the changeover switch 10 is not in the "test" position in step st2, the process proceeds to step st3, and it is determined whether or not the changeover switch 10 is in the "A mode (single phase 100V)". When the changeover switch 10 is in the “A mode”, the process proceeds to “A mode process” in step st7, and when the changeover switch 10 is not in the “A mode”, the process proceeds to step st4. In step st4, the changeover switch 10
Is in the “B mode (single-phase 200 V)”. When the changeover switch 10 is in the “B mode”, the process proceeds to “B mode process” in step st8, and when the changeover switch 10 is not in the “B mode”, the process proceeds to step st5. In this step st5, the changeover switch 10 is set to “C
Mode (single-phase three-wire 100V) "is determined. When the changeover switch 10 is in the "C mode", the process proceeds to "C mode processing" in step st9. When the changeover switch 10 is not in the "C mode", the process proceeds to "D mode (three-phase three-wire 200V)" in step st6. And returns to step st2.

Steps st7 and st8
The “A mode processing” and the “B mode processing” are started at step st12 as shown in FIG.
Proceed to step st13, and in this step st13, "B
It is determined whether or not "mode processing" is selected. "B
If “mode processing” is selected, the process proceeds to step st21. If “B mode processing” is not selected, “A” is selected.
The process proceeds to step st14 as “mode processing”. In this step st14, it is determined whether or not the voltage V1 is 15 V or less.
The display proceeds to step st27 to determine whether the voltage V1 is equal to or lower than 85V. Voltage V
If 1 is equal to or lower than 85 V, the process proceeds to step st19 to display "No", and then proceeds to step st27 where the voltage V
If 1 is not equal to or less than 85, the process proceeds to step st16. In this step st16, it is determined whether or not the voltage V1 is 115 V or more. If the voltage V1 is equal to or higher than 115 V, the process proceeds to step st20 to display "No", and then proceeds to step st.
The process proceeds to 27, and if the voltage V1 is not 115 or more, the process proceeds to step st17. Then, in this step st17, "good" is displayed, and the process proceeds to step st27. In step st21, it is determined whether or not the voltage V1 is equal to or lower than 30V. If the voltage V1 is equal to or lower than 30 V, the process proceeds to step st24 to display "impossible",
Proceeding to t27, if the voltage V1 is not equal to or lower than 30 V, proceeding to step st22. In step st22, the voltage V1
Is 170 V or less. Voltage V1 is 170V
If not, the process proceeds to step st25 to display “No”, and proceeds to step st27, where the voltage V1 is 170 V
If not, the process proceeds to step st23. In this step st23, it is determined whether or not the voltage V1 is 230 V or more. If the voltage V1 is 230 V or more, step st2
Then, the process proceeds to step st6, where "no" is displayed, and the process proceeds to step st27. If the voltage V1 is not 170 or more, the process proceeds to step st1.
Go to 7. In step st17, "good" is displayed, and the process proceeds to step st27.

Then, in this step st27, it is determined whether or not the voltage I1 is 25 mV or less. Voltage I1 is 25
If it is 0 mV or less, the process proceeds to step st32, and “impossible”
Is displayed, and the process returns to the main routine shown in FIG. 15, and if the voltage I1 is not 25 mV or less, the process proceeds to step st28. In this step st28, the voltage I1 is 375 m
It is determined whether it is V or more. If the voltage I1 is 375 mV or more, the process proceeds to step st33 to display "No" and returns to the main routine. If the voltage I1 is not 375 or less, the process proceeds to step st29. In step st29, it is determined whether or not V1 is “good”. If V1 is “good”, the process proceeds to step st30, and if V1 is not “good”, the process returns to the main routine. In step st30, V
It is determined whether or not the phase difference between 1 and I1 is within 0 degrees to plus 60 degrees. If the phase difference is within the range of 0 degree to plus 60 degrees, the process proceeds to step st31, "I" is displayed for I1, and the process returns to the main routine.
If it is not within degrees or plus 60 degrees, step st34
To display "No" for I1, and return to the main routine.

In the "C mode process" in step st9, as shown in FIG. 17, the process starts in step st35, and proceeds to step st36. In step st36, the flags indicating "good" for V1, V3, and I1 are cleared, and the process proceeds to step st37. In step st37, it is determined whether or not the voltage V1 is equal to or lower than 15V. If the voltage V1 is equal to or less than 15 V, a step st45 is performed.
The program proceeds to step st41 to display "impossible" and proceeds to step st41.
Proceed to. In step st38, it is determined whether or not the voltage V1 is equal to or lower than 85V. If the voltage V1 is equal to or lower than 85 V, the process proceeds to step st46 to display "No", and then to step s.
Proceeding to t41, if the voltage V1 is not equal to or lower than 85V, proceeding to step st39. In this step st39, it is determined whether or not the voltage V1 is 115 V or more. Voltage V1 is 11
If it is 5 V or more, the process proceeds to step st47 to display “No”, and proceeds to step st41, where the voltage V1 is 115
If not, the process proceeds to step st40. In step st40, a "good" flag for the voltage V1 is set, and the process proceeds to step st41.

In step st41, the voltage V3 is set to 15V
It is determined whether or not: If the voltage V3 is equal to or less than 15 V, the process proceeds to step st48, and “impossible” is displayed, and FIG.
The process proceeds to step st51 shown in FIG. 8, and if the voltage V3 is not less than 15 V, the process proceeds to step st42. In this step st42, it is determined whether or not the voltage V3 is equal to or lower than 85V. If the voltage V3 is equal to or lower than 85 V, the operation proceeds to step st49.
The process proceeds to step st51 to display "No" and proceeds to step st51. If the voltage V3 is not equal to or lower than 85 V, the process proceeds to step st4.
Proceed to 3. In this step st43, the voltage V3 becomes 11
It is determined whether the voltage is 5 V or more. If the voltage V3 is equal to or higher than 115V, the process proceeds to step st50 to display "No", and the process proceeds to step st51. If the voltage V3 is not equal to or higher than 115V, the process proceeds to step st44. This step s
At t44, a "good" flag is set for the voltage V3, and the flow proceeds to step st51.

At step st51, it is determined whether or not the "good" flag is set for V1 and V3. If the "good" flag is set, the process proceeds to step st51, and the "good" flag is set. If is not set, the process proceeds to step st56. In step st52, it is determined whether or not the phase difference between V1 and V3 is plus 180 degrees. If the phase difference is plus 180 degrees, the process proceeds to step st53, "good" is displayed for V1 and V3, and the process proceeds to step st54. Step st
In 56, it is determined whether or not the flag of V1 is “good”. If the flag of V1 is “good”, the process proceeds to step st57.
Is displayed for "V1" at step st58.
To step s if the flag of V1 is not "good"
Proceed to t58. In this step st58, it is determined whether or not the flag of V3 is "good". If the flag of V3 is "good", "good" for V3 is displayed in step st59, and the process proceeds to step st54. , V3 are not "good", the process proceeds to step st54.
In step st55, "NO" is displayed for V1 and V3, and the flow advances to step st54. Step st54
Then, it is determined whether or not the voltage I1 is 25 mV or less,
If the voltage I1 is equal to or less than 25 mV, the process proceeds to step st65 to display "impossible" and then proceeds to step st62.
If the voltage I1 is not less than 25 mV, the process proceeds to step st60. In step st60, it is determined whether or not the voltage I1 is equal to or more than 375 mV. If the voltage I1 is equal to or more than 375 mV, the process proceeds to step st66 to display "No" and the process proceeds to step st62, and if the voltage I1 is equal to or more than 375 mV. If not, the process proceeds to step st61. In step st61, a "good" flag is set for the voltage I1, and the process proceeds to step st62.

At step st62, the voltage I3 is 25 m
It is determined whether or not the voltage is equal to or less than V. If the voltage I3 is equal to or less than 25 mV, the process proceeds to step st67 to display "impossible", and then proceeds to step st69 shown in FIG.
Is less than or equal to 25 mV, the process proceeds to step st63.
In step st63, it is determined whether or not the voltage I3 is equal to or more than 375 mV. If the voltage I3 is equal to or more than 375 mV, the process proceeds to step st68 to display "No", and proceeds to step st69. If not, the process proceeds to step st64. In step st64, a "good" flag is set for the voltage I3, and step s
Proceed to t69. In step st69, the determination signal (I
t) is determined, and if there is a determination signal, the process proceeds to step st70; otherwise, the process proceeds to step st75.
To display "No" for I1 and I3,
Return to the main routine. In step st70, V1,
It is determined whether or not the "good" flag has been set for I1. If the "good" flag has been set, the process proceeds to step st71. If the "good" flag has not been set, the process proceeds to the main routine. Return. In step st71,
It is determined whether or not the phase difference between V1 and I1 is within 0 degree to plus 60 degrees. If the phase difference is within 0 degree to plus 60 degrees, the process proceeds to step st72, "good" is displayed for I1, and the process proceeds to step st73. If the phase difference is not within the range of 0 degree to plus 60 degrees, step s
Proceeding to t76, "No" is displayed for I1, and the process proceeds to step st73.

In step st73, V3, I3
It is determined whether or not the “good” flag is set. If the "good" flag has been set, the process proceeds to step st74. If the "good" flag has not been set, the process returns to the main routine. In step st74,
It is determined whether or not the phase difference between V3 and I3 is within 0 degree to plus 60 degrees. If the phase difference is within 0 degree to plus 60 degrees, the process proceeds to step st78, where "good" is displayed for I3, and the process returns to the main routine.
If it is not within degrees or plus 60 degrees, step st77
To display "No" for I3 and return to the main routine.

Further, "D mode processing" in step st6
Starts the process at step st79 as shown in FIG. 20, and proceeds to step st80. In step st80, the "good" flags for V1, V3 and I1 are cleared, and the process proceeds to step st81. In step st81, it is determined whether or not the voltage V1 is equal to or lower than 30V. Voltage V1
If the voltage is equal to or less than 30 V, the process proceeds to step st89 to display “impossible”, and then proceeds to step st85, where the voltage V1
Is less than or equal to 30 V, the process proceeds to step st82. In step st82, it is determined whether or not the voltage V1 is 170 V or less. If the voltage V1 is equal to or lower than 170 V, the process proceeds to step st90 to display "No" and to step st8.
The process proceeds to step 5, and if the voltage V1 is not 170 V or less, the process proceeds to step st83. In step st83, it is determined whether or not the voltage V1 is equal to or higher than 230V. If the voltage V1 is 230 V or more, the process proceeds to step st91 to display "No", and the process proceeds to step st85. If the voltage V1 is not 230 V or more, the process proceeds to step st84. Step st
At 84, a "good" flag is set for V1, and the process proceeds to step st85. In step st85, the voltage V
3 is determined to be 30 V or less. If the voltage V3 is equal to or lower than 30 V, the process proceeds to step st92 to display "impossible", and then proceeds to step st95 shown in FIG.
If 3 is not less than 30 V, the process proceeds to step st86.
In step st86, it is determined whether or not the voltage V3 is 170 V or less. If the voltage V3 is equal to or lower than 170 V, the process proceeds to step st93 to display "No", and to step st93.
The process proceeds to 85, and if the voltage V3 is not 170 V or less, the process proceeds to step st87. In step st87, the voltage V3
Is 230 V or more. Voltage V3 is 230V
If so, the process proceeds to step st94 to display “No”, and then proceeds to step st95, where the voltage V3 is set to 230V.
If not, the process proceeds to step st88. Steps
At t88, a "good" flag is set for the voltage V3, and the flow proceeds to step st95.

In step st95, it is determined whether or not the "good" flag is set for V1 and V3. If the "good" flag is set, step s
Proceeding to t96, if the "good" flag is not set, the process proceeds to step st102. In step st96, it is determined whether or not the phase order is positive. If the phase sequence is not positive, the process proceeds to step st99. If the phase sequence is positive, the process proceeds to step st97, where the display of the phase sequence is “positive”, and in step st98, “good” is displayed for V1 and V3. The process proceeds to step st107. In step st99, it is determined whether or not the phase order is reversed. If the phase order is not reversed, the process proceeds to step st101. If the phase order is reversed, the process proceeds to step st100, a display indicating that the phase sequence is "reverse" is performed, and the process proceeds to step st98. In step st101, the display of the phase sequence is turned off, and the process proceeds to step st98. In step st102, it is determined whether or not the flag of V1 is “good”. If the flag of V1 is “good”, “good” for V1 is displayed in step st103, and the process proceeds to step st104. If the flag of V1 is not “good”, the process proceeds to step st104. Step st104
Then, it is determined whether or not the flag of V3 is "good".
If the flag of No. 3 is “good”, V is determined in step st105.
“Good” is displayed for No. 3 and step st106
To step s if the flag of V3 is not "good"
Proceed to t106. In step st106, the display of the phase sequence is turned off, and the process proceeds to step st107. In step st107, it is determined whether or not the voltage I1 is equal to or less than 25 mV. If the voltage I1 is equal to or less than 25 mV, the process proceeds to step st113 to display “impossible” and the process proceeds to step st110, where the voltage I1 is equal to or less than 25 mV. If not, the process proceeds to step st108. Step st108
Then, it is determined whether or not the voltage I1 is 375 mV or more, and if the voltage I1 is 375 mV or more, step st1 is executed.
Proceeding to 14, display "NO" is performed, and step st110 is performed.
If the voltage I1 is not equal to or more than 375 mV, the process proceeds to step st109. In step st109, the voltage I
Set the "good" flag for 1 and step st
Proceed to 110.

At step st110, the voltage I3 is 25
It is determined whether or not the voltage I3 is equal to or less than mV. If the voltage I3 is equal to or less than 25 mV, the process proceeds to step st115 to display "impossible" and returns to the main routine, where the voltage I3 is 25 mV.
If not, the process proceeds to step st111. In step st111, it is determined whether or not the voltage I3 is equal to or more than 375 mV. If the voltage I3 is equal to or more than 375 mV, the process proceeds to step st116 to display "No" and returns to the main routine, where the voltage I3 is equal to or more than 375 mV. If not,
Proceed to step st112. In step st112,
The "good" flag for the voltage I3 is set, and the process proceeds to step st117. In step st117, V1,
It is determined whether or not the “good” flag is set for V3 and I1. If the “good” flag is set, the process proceeds to step st118 shown in FIG. 22, and the “good” flag is set. If not, return to the main routine. In step st118, it is determined whether or not the phase order is normal or reverse. If the determination is successful, the process proceeds to step st119. If the determination is not successful, the process returns to the main routine. In step st119, it is determined whether or not the "good" flag is set for V1 and I1, and if the "good" flag is set, step st
Proceed to 120 and return to the main routine if the "good" flag is not set. In step st120,
It is determined whether or not the phase difference between V1 and I1 is within plus 30 degrees to plus 90 degrees. If the phase difference is within plus 30 degrees to plus 90 degrees, the process proceeds to step st121, "good" is displayed for I1, and step st1 is performed.
Proceeding to 23, if the phase difference is not within plus 30 degrees to plus 90 degrees, proceed to step st122, display "No" for I1, and proceed to step st123.

In this step st123, V3, I3
It is determined whether or not the “good” flag is set, and if it is set, the process proceeds to step st124.
If not set, the process returns to the main routine. In step st124, the phase difference between V3 and I3 is minus 30.
It is determined whether or not the phase difference is within 30 degrees or plus 30 degrees. If the phase difference is within minus 30 degrees or plus 30 degrees, the process proceeds to step st125, "good" is displayed for I3, and the process returns to the main routine. If the phase difference is not within minus 30 degrees to plus 30 degrees, the process proceeds to step st126, "No" is displayed for I3, and the process returns to the main routine.

Next, the relationship between the connection state in the watt-hour meter connection determination device and the display on the display unit is shown in a table. When the connection is determined for the watt hour meter corresponding to the single-phase two-wire (100 V, 200 V) power supply, as shown in FIG. 23, only one of the voltage side and the current side is incorrectly connected. Indicates that the connection is abnormal on the display unit (patterns 1 and 2), but if both the voltage side and the current side are incorrectly connected, the connection is abnormal on the display unit. Is not displayed (pattern 3). However, in this case, no problem occurs with respect to the coefficient of the electric energy. When the connection is determined for the watt hour meter corresponding to the single-phase three-wire (100 V) power supply, FIG.
As shown in FIG. 4, various lighting patterns appear on the display unit according to the combination of the incorrect connection patterns on the voltage side and the current side. Among them, there are lighting patterns that have the same lighting pattern as in the normal connection state. In this case, there is no problem regarding the coefficient of the electric energy, but the abnormality is detected by injecting the discrimination signal by the transmitter 11. Can be.
Further, when the connection is determined for the watt hour meter corresponding to the three-phase three-wire (200 V) power supply, as shown in FIG. 25, the display is made according to the combination of the incorrect connection patterns on the voltage side and the current side. In the section, various lighting patterns appear, and abnormal connection can be determined.

[0040]

As is clear from the above description of the embodiment of the present invention, in the connection determination device for a watt hour meter according to the present invention, the power consumption of the AC power supplied through the power supply line is reduced. A connection part connected to the terminal part of the watt-hour meter for integrating and measuring, the voltage applied from the power supply line to the terminal part of the watt-hour meter via this connection part, and the low-voltage transformer attached to the power supply line A detecting unit for detecting a current supplied from the measuring device to a terminal of the watt-hour meter, a phase comparing unit for detecting a phase difference between the voltage and the current detected by the detecting unit, and a detecting unit for detecting the phase. It is determined whether or not the phase difference between the applied voltage and current is within a specified value, and when the phase difference is within the specified value, it is determined that the connection from the power supply line to the terminal of the watt hour meter is correct. And the judgment result by the judgment unit is displayed. It is constituted by a that display unit.

Therefore, in the connection determination device for the watt hour meter according to the present invention, the correctness of the connection state from the power supply line side to the watt hour meter used with the low-voltage transformer can be easily and reliably determined in the live state. Thus, the watt hour meter can be brought into a state where power consumption can be measured normally.

By making the judgment by the judging unit and the display by the display unit to be performed for each circuit constituting the watt-hour meter, it becomes clear at a glance which circuit has an abnormal connection, and this makes it easy for the operator. Can be extremely easy to use.

Further, a changeover switch for selecting a power supply method by the power supply line is provided, and the determination section switches the content of the determination in accordance with the switching state of the changeover switch, so that various types of power supply methods corresponding to different power supply methods are provided. It is also possible to determine the abnormal connection of the watt-hour meter, so that it is not necessary to carry each watt-hour connection determination device corresponding to the power supply method.

When the watt-hour meter is a three-phase watt-hour meter that integrates and measures the power consumption in the three-phase power supply, the determination unit is connected to the terminal of the watt-hour meter from the power supply line side. By determining the phase sequence of the connection, it is possible to more reliably determine the abnormal connection.

In the case where the target watt-hour meter is a single-phase three-wire watt-hour meter that integrates and measures the power consumption in a single-phase three-wire power supply, the pair of low-voltage transformers A transmitter connected to one of the secondary terminals and injecting a discrimination signal into the secondary terminal is used, and the judgment unit detects through the connection unit whether or not the discrimination signal is injected by the transmitter. If it is determined whether or not the connection from the power supply line to the terminal of the watt hour meter is correct based on the detection result, an abnormal connection that cannot be determined only from the phase difference between the voltage and the current is detected. be able to.

[Brief description of the drawings]

FIG. 1 is a front view showing a state in which a connection determination device for a watt hour meter according to the present invention is attached to a watt hour meter.

FIG. 2 is a block diagram showing a state in which the connection determination device for a watt hour meter is attached to a watt hour meter.

FIG. 3 is a front view showing a configuration of a display unit of the watt-hour meter connection determination device.

FIG. 4 is a plan view showing a configuration of a connection portion of the connection determination device for the watt hour meter.

FIG. 5 is a plan view showing a state in which a connection part of the connection determination device for the watt hour meter is attached to the watt hour meter.

FIG. 6 is a front view showing a configuration of a main body of the watt-hour meter connection determination device.

FIG. 7 is a front view showing a configuration of a transmitter of the connection determination device for a watt hour meter.

FIG. 8 is a block diagram showing a configuration of a main body of the watt-hour meter connection determination device.

FIG. 9 is a waveform diagram showing signals detected by the connection determination device for a watt hour meter.

FIG. 10 is a block diagram showing a configuration of a transmitter of the connection determination device for a watt hour meter.

FIG. 11 is a waveform diagram showing a discrimination signal transmitted by a transmitter of the connection determination device for a watt hour meter.

FIG. 12 is a schematic diagram showing a phase difference between a normal connection (a) and an abnormal connection (b) between voltage and current in single-phase two-wire power supply.

FIG. 13 is a schematic diagram illustrating a phase difference between a voltage and a current in a single-phase three-wire power supply during normal connection (a) and abnormal connection (b).

FIG. 14 is a schematic diagram illustrating a phase difference between a voltage and a current during normal connection (a) and abnormal connection (b) in three-phase three-wire power supply.

FIG. 15 is a flowchart showing a main routine of the operation of the microcomputer of the connection determination device for the watt hour meter.

FIG. 16 is a flowchart showing the operation of the microcomputer of the connection determination device for an electric energy meter when the A mode is selected and the B mode is selected.

FIG. 17 is a flowchart showing the operation of the microcomputer of the watt-hour meter connection determination device when the C mode is selected.

FIG. 18 is a flowchart showing a continuation of the operation of the microcomputer of the watt-hour meter connection determination device when the C mode is selected.

FIG. 19 is a flowchart showing a further continuation of the operation of the microcomputer of the watt-hour meter connection determination device when the C mode is selected.

FIG. 20 is a flowchart showing an operation of the microcomputer of the watt-hour meter connection determination device when the D mode is selected.

FIG. 21 is a flowchart showing the continuation of the operation of the microcomputer of the watt-hour meter connection determination device when the D mode is selected.

FIG. 22 is a flowchart showing a further continuation of the operation of the microcomputer of the watt-hour meter connection determination device when the D mode is selected.

FIG. 23 is a list showing a relationship between a connection state and a display state in single-phase two-wire power supply.

FIG. 24 is a list showing a relationship between a connection state and a display state in single-phase three-wire power supply.

FIG. 25 is a list showing a relationship between a connection state and a display state in three-phase three-wire power supply.

FIG. 26 is a front view showing the configuration of a watt hour meter, a power supply line, and a transformer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Connection part 2 Main body part 3 Contact 7 Microcomputer 8 Display part 10 Changeover switch 11 Transmitter

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshinori Aizawa 1-4-11, Nakazato, Furukawa-shi, Miyagi Tohoku Electric Power Co., Inc. In-company (72) Inventor Ritsukazu Iwatani 1 Kibuki-cho, Kasugai-shi, Aichi Chubu Seiki Co., Ltd. (56) References JP-A-8-62272 (JP, A) JP-A-5-10973 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G01R 35/04-35/06 G01R 21/00-22/04 G01R 11/00-11/66 G01R 31/02-31/06

Claims (5)

(57) [Claims] A connection unit connected to a terminal of a watt hour meter for integrating and measuring the power consumption of AC power supplied via a power supply line; and connecting the power supply line to the power supply line via the connection unit. A detecting unit for detecting a voltage applied to a terminal of the watt-hour meter and a current supplied to a terminal of the watt-hour meter from a low-voltage transformer attached to the power supply line; A phase comparator for comparing the phase difference between the voltage and the current, and determining whether or not the phase difference between the voltage and the current detected by the phase comparator is within a specified value. A determination unit that determines that the connection from the power supply line side to the terminal unit of the watt-hour meter is correct, and a display unit that displays a determination result by the determination unit. Connection determination device for watt hour meter. 2. The watt hour meter connection determination device according to claim 1, wherein the determination by the determination unit and the display by the display unit are performed for each circuit constituting the watt hour meter. 3. The switch according to claim 1, further comprising a changeover switch for selecting a power supply method using the power supply line, wherein the determination unit switches the determination content in accordance with a switching state of the changeover switch. Connection determination device for watt hour meter. 4. When the watt-hour meter is a three-phase watt-hour meter that integrates and measures power consumption in three-phase power feeding, a terminal of the watt-hour meter is provided from a power supply line side. 2. The method according to claim 1, further comprising the step of judging a phase sequence of connection to the part.
The connection determination device for the watt hour meter according to the above. 5. When the watt-hour meter is a single-phase three-wire watt-hour meter that integrates and measures power consumption in a single-phase three-wire power supply, the power meter may include one of a pair of low-voltage transformers. A transmitter connected to the secondary terminal and injecting a determination signal into the secondary terminal, wherein the determination unit detects presence / absence of the determination signal injected by the transmitter via the connection unit; 2. The watt-hour meter connection determination device according to claim 1, wherein it is determined whether or not the connection from the power supply line side to the terminal of the watt-hour meter is correct based on the detection result.