JP2000074960A - Method and device for metering watthour for every time zone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make omittable a power failure backup function by tentatively metering a watthour until current time information can be obtained after the recovery from power failure in case of a power failure and calculating the watthour for every time zone when the current time is obtained. SOLUTION: The metering device 10 of watthour for every time zone where automatic meter reading or the like is applied is provided with a nonvolatile memory 13 where watthour data is written when detecting a power failure, a tentative metering memory 14 that functions when recovering from the power failure. And, when a power failure detection circuit 11 detects the recovery of a commercial power supply after the power failure, the locking of a clock part 12 is started and the watthour of the nonvolatile memory 13 is displayed at a display part 3. The metering value of watthour after recovery from a power failure is successively stored in the tentative metering memory 14, and at the same time, the display part is also updated. The tentative metering memory 14 continues to tentatively meter lapse time and watthour until there is a time reply, for example, by responding to a current time report request from a communication control part 15 and distributes the tentative metering value to a normal time zone and adds it to the value of the nonvolatile memory 13 where time is replied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for measuring the amount of electric power by time, which measures the amount of electric power having different power rates according to the time of use of electric power.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a conventional electronic watt-hour meter disclosed, for example, in Japanese Patent Laid-Open Publication No. 3-85487. In the figure, reference numeral 1 denotes a power amount frequency conversion circuit (W / F) which takes in voltage and current signals of an electric circuit to be weighed connected to a commercial power supply and converts it into a frequency signal proportional to the power amount.
Conversion circuit), 2 is a microcomputer (MPU), 3
Is a power meter display, which can display power meter values for a plurality of time zones. Reference numeral 4 denotes a clock unit, 5 denotes a waveform shaping circuit that captures a zero-cross point of an AC frequency of the electric circuit to be measured and generates a correction reference signal of the clock unit 4, 6 denotes a power failure compensation battery, and 7 denotes a power failure compensation battery 6 when a power failure occurs. Is a power supply circuit that organizes drive power for the microcomputer 2 and the clock unit 4 from the power supply.

[0003] Next, the operation of the above-mentioned conventional electronic watt-hour meter for performing hourly metering will be described. A frequency signal proportional to the amount of power measured by the power amount frequency conversion circuit 1 is formed into a measured power value by the microcomputer 2 and the display unit 3
Sent to The microcomputer 4 determines which time zone the clock time of the clock unit 4 is for a predetermined time zone segment, such as a night time zone from 23:00 to 7:00 and a daytime zone at other times. 2 makes a judgment, and displays the total of the electric power measured values in the corresponding time zone. Here, the time setting and correction are performed so that the time measured by the clock unit 4 matches the standard time.

However, a commercial power supply sometimes causes a power failure. At the time of the power failure, the microcomputer 2, which is in the power saving mode, the memory in the microcomputer 2, and the clock unit 4 are kept operating by the power from the power failure compensation battery 6. When the power failure state is resolved (power recovery), the microcomputer 2 returns to the normal mode, reads the weighing data from the memory, returns to the state before the power failure, and continues power measurement.

[0005]

As described above, in the conventional electronic watt-hour meter that performs hourly metering, it is necessary to operate the clock unit 4 in preparation for resuming metering at the time of power recovery as described above. Therefore, the power failure compensation battery 6 must be provided, and when the battery is exhausted, it is necessary to replace the battery and set the time again, and there is a problem that the maintainability is poor.

The present invention has been made to solve such a problem. In recent years, meter reading of watt-hour meters has come to be automatically performed by using a telephone line or the like from a remote meter reading computer. Automatic meter reading is more frequent in hourly metering electronic watt-hour meters, and clock data is corrected from power recovery in electronic watt-hour meters that do not have a clock outage compensation function, using the clock of the meter reading computer. It is an object of the present invention to provide a means for distributing the measured power value until the measurement is performed to the regular time-based measurement, and to omit a clock unit having a power failure backup function.

[0007]

According to the present invention, there is provided a method for measuring the amount of electric power for each time zone, comprising measuring the amount of electric power used for each time zone,
In the method of measuring the electric energy by time zone, which sends this to an external meter reading computer via a communication line, the watt hour meter stores the measured value before the power failure, and requests the current time information from the meter reading computer after the power is restored. From the time the power is restored until the current time information is answered, the amount of power is provisionally measured along with the time elapsed since the power restoration, and when the current time information is received, the regular time is calculated from the elapsed time of the provisional measurement. The provisional weighing value is allocated to the power amount for each predetermined time period and added to the weighing value before the power failure.

[0008] Further, a time-zone-based power amount measuring apparatus according to the present invention is connected to an external meter-reading computer via a communication line, and includes means for storing a measured value before a power failure, and A means for inquiring the meter reading computer of the current time, and a temporary metering memory for temporarily measuring and storing the amount of electric power during the time from power recovery to the answer to the current time and temporarily storing the power amount, are provided from the meter reading computer. The temporary weighing value corresponding to the time information of the regular time is obtained from the elapsed time information of the temporary weighing memory based on the answer time of the temporary weighing memory, and the temporary weighing value corresponding to the predetermined time zone-based weighing switching time is obtained. Is assigned to each time zone and added to the weighing value stored before the power failure.

The provisional weighing memory is configured to store elapsed time information for each carry of any unit value of the power weighing value.

The provisional weighing memory is configured to store a provisional weighing value of the electric energy for each unit time of the elapsed time.

The temporary weighing memory is configured to store the temporary weighing value while changing the unit time width according to the elapsed time from the power recovery.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a power meter for each time zone and its automatic meter reading system according to Embodiment 1 of the present invention. In the figure, reference numeral 10 denotes a power meter for each time zone, reference numeral 20 denotes an automatic meter reading host computer, and reference numeral 21 denotes a communication line such as a telephone line for connecting the two. Electricity meter by time zone 10
Among them, 1 is a power amount frequency conversion circuit (W / F conversion circuit) which takes in the voltage v and the current i of the electric circuit to be weighed connected to the commercial power supply and converts it into a frequency signal proportional to the power amount, and 2 is a micro unit. A computer (MPU) 3 is a power meter display, which is capable of displaying power meter values for a plurality of time zones. 11 is a power failure detection circuit for detecting a power failure and power recovery of the electric circuit to be measured, 12 is a clock unit having no power failure backup, 13 is a nonvolatile memory connected to the microcomputer 2, 14 is a temporary measurement memory, and 15 is an external memory. Is a communication control unit that transmits and receives data to and from the automatic meter reading host computer 20 via the communication line 21. Reference numeral 16 denotes a time setting unit, and 17 denotes a power supply unit that organizes driving power of each unit from an input of the electric circuit to be measured.

The power meter for each time zone configured as described above performs the same operation as the conventional electronic watt-hour meter in the usual power metering for each time zone. However, the electric energy data is displayed on the display 3 and is also written into the nonvolatile memory 13 when a power failure is detected. When a meter reading request signal arrives at a predetermined time from the automatic meter reading host computer 20 connected via the communication line 21, the microcomputer 2
Power data stored in the memory of the communication control unit 1
At step 5, a message in a predetermined format is sent back to the automatic meter reading host computer 20.

Next, the operation at the time of power recovery from a power failure will be described with reference to FIG. When the power failure detection circuit 11 detects the restoration of the commercial power supply, the microcomputer 2 starts operating,
At this point, "00:00" is set in the clock section 12, and time counting is started (steps 201 and 202). Then, the electric energy meter 1 displays the electric energy data of the nonvolatile memory 13 and clears the temporary metering memory 14.
The amount of power passing zero is measured, and the measured value is started to be recorded in the temporary weighing memory 14 and the display 3 is updated (steps 203 and 204). On the other hand, the communication control unit 15
Request the notification of the current time to the automatic meter reading host computer 20 via. The temporary metering memory 14 continues the temporary measurement of the elapsed time and the electric energy by the clock unit 12 until there is a reply of the current time held by the automatic meter reading host computer 20 (steps 205 and 206).

If the communication line 21 is normal and a power failure occurs only with the commercial power supply, the automatic meter reading host computer 20 responds to the time in a relatively short time. There is a case where the power is restored first and the restoration of the communication line 21 is delayed. At this time, since the time notification request from the power metering device 10 has not reached the automatic meter reading host computer 20, the communication line 21 is restored while the time notification request is retransmitted every predetermined time (for example, one hour). Provisional weighing continues until a response is received.

The current time returned from the automatic meter reading host computer 20 and the clock unit 12 set to zero when the power is restored.
With reference to the elapsed time, the temporary weighing value is allocated to the weighing value in the normal time zone, added to the weighing value in the nonvolatile memory 13, and the display on the display 3 is also updated (step 20).
7, 208). Various methods are conceivable for the method of distributing the temporary weighing values, which will be described later in detail. The time of the clock unit 12 is updated to the current time returned from the automatic meter reading host computer 20, and the subsequent time-based weighing is continued (step 209).

FIG. 3 is a flow chart of an example in which the temporary metering value after the power recovery from the power outage is distributed to the normal time zone in the hourly power amount metering device 10 according to the first embodiment. FIG. 4 is a schematic example of the temporary weighing memory. Here, a description will be given on the assumption that the night time zone is set at 23:00 to 7:00 and the day time zone is set at 7:00 to 23:00 as the measurement time zone division. In FIG. 3, the clock unit 12
Is reset at 00:00, and the measurement of the electric energy is started at the same time (steps 301 and 302).

Until there is a response of the current time from the automatic meter reading host computer 20, the elapsed time from reset when the measured value of the electric energy is carried in the minimum unit of display (1 kWh in the following description) is shown. 4 is recorded in the temporary weighing memory 14 for each digit of each kWh as shown in the schematic example of FIG. 4 (steps 303 to 305). When an answer of the current time comes from the automatic meter reading host computer 20, the elapsed time of each kWh from the reset of the temporary weighing memory 14 is restored to the normal time (see the right half of FIG. 4) based on the answer time. Step 306). The restored time is searched, and it is checked whether or not a time zone division time period (07:00 in FIG. 4) exists within the restoration time. If the time zone division time period does not exist, provisional weighing to the current time zone is performed. Clock unit 1
The time 2 is updated to the answer time, and the measurement of the electric energy is continued (steps 307 to 309). If there is a time zone division time within the restoration time, the measured power amount immediately before the time zone division time is reached is returned to the previous time zone division. The amount of power generated immediately after the lapse is distributed and measured for the amount of time that has passed over each time zone (steps 310 to 312), the time of the clock unit 12 is updated to the answer time, and the measurement of the amount of power is continued.

This will be described with reference to the example of FIG. Power recovery is at 6:03
Although it is 5 minutes, the clock unit 12 is reset at 00:00, regardless of which, and the clock starts. When the display value of the display unit 3 displaying the measured value of the electric energy is carried in units of 1 kWh, the elapsed time of the clock unit 12 is recorded for each kWh. In the example of FIG. 4, the first 1 kWh is 3 minutes, and up to 2 kWh is 9 minutes. Actually, the data is recorded in units of seconds, but here, the description is made in units of minutes to simplify the description. When the automatic meter reading host computer 20 responds that the current time is 7:55 at 1 hour and 20 minutes after the reset, 1 hour and 20 minutes from 7:55 is the starting point.
The carry time (see the right half of FIG. 4) of each kWh for each minute is restored. Time zone division time period (07: 0) within the restored time
0) is present, the power amount up to that point is 4 k
Wh is weighed during the night hours. Since 1 kWh generated from 6:59 to 7:05 is a time zone division time limit of 7:00, the amount of power for one minute from 6:59 to 7:00 is changed to nighttime at 7:00. The amount of power for 5 minutes from 00 minutes to 7:05 is 1 kWh proportionally in the daytime. 20 kWh, which is a difference from the total power value of 24 kWh for one hour and 20 minutes, is added to the daytime time zone and the distribution is completed.

Automatic power meter reading from power recovery Host computer 20
When it takes 12 hours or more for the time response, there are two or more time zone division times, but it is possible to distribute the power measurement value to each time zone from the restoration time. The method of distributing the time restoration measurement values according to the first embodiment is suitable for a watt hour meter installed in a consumer who uses relatively little power, and the storage capacity of the temporary measurement memory 14 does not need to be increased.

Embodiment 2 FIG. FIG. 5 is a flowchart showing another method of distributing the temporary weighing value after power recovery from a power failure to a normal time zone in the hourly electric energy metering device, and FIG.
FIG. 3 is a schematic diagram of a temporary weighing memory. The setting of the night time zone from 23:00 to 7:00 and the daytime time zone from 7:00 to 23:00 and the steps 301 to 303 are the same as those in the first embodiment, and therefore the description is omitted. In the second embodiment, every two minutes (every unit time) of clocking of the clock unit 12 reset at 00:00 due to power recovery, the electric energy value passing through the watt hour meter during this time is stored in the temporary weighing memory 14. And the elapsed time. Each power amount for every two minutes which is the first unit time width is stored in the temporary weighing memory 14 together with the elapsed time (steps 501 to 503). In this example, the memory capacity in two-minute units is 30 (one hour). Therefore, if there is no time response for one hour or more after the power recovery, the power is temporarily stored in the temporary weighing memory 14 in ten-minute units, which is the next unit time width. The amount is stored together with the elapsed time (steps 504 to 506). Then, when the prepared memory capacity of the unit of 10 minutes is exhausted, the memory is switched to the unit of one hour and stored (steps 507 and 508). this is,
This is a measure to prevent the storage capacity of the temporary weighing memory 14 from increasing when the time required for the time response becomes longer, at the expense of some time zone distribution accuracy. Temporary weighing memory 14
The total size of the temporary weighing memory 14 in units of one hour secures a memory capacity that allows temporary weighing for a time corresponding to the life of the power failure compensation battery of the conventional example.

When there is an answer of the current time from the automatic meter reading host computer 20, the elapsed time in the temporary weighing memory 14 is normalized to the regular time based on the current time (see the right half of FIG. 6).
(Step 510). Then, the weighed value that has not been recorded in the temporary weighing memory 14 when the time is answered is added to the current time zone division (step 509). The restored regular time is searched to check whether or not a time zone division time period (07:00 in FIG. 6) exists within the restored time. If the time zone division time period does not exist, provisional weighing is performed to the current time zone. , The time of the clock unit 12 is updated to the answer time, and the measurement of the electric energy is continued (steps 511 to 51).
3). If there is a time zone division time period within the restoration time, the measured power amount immediately before the unit time frame corresponding to the time zone division time period is transferred to the previous time zone period, and the measured power amount immediately after the unit time frame is applied. To the current time zone division and weigh. Here, the measured power amount of the unit time frame corresponding to the time zone division time is apportioned and distributed to each time zone according to the position of the time zone division time within the width time of the unit time frame (step 514-515).

This case will be described with reference to FIG. Power recovery is 6
Although the time is 35 minutes, the clock unit 12 is reset to 00:00 regardless of the start, and starts counting time. Each power amount for every two minutes which is the first unit time width is stored in the temporary measurement memory 14 together with the elapsed time. In this example, the memory capacity in units of 2 minutes is 3
Since there are no times (one hour), if there is no time response for one hour or more after the power recovery, the state has advanced to the next unit time width of 10 minutes. Assuming that the time response of the automatic meter reading host computer 20 is 8:11, each storage unit time of the temporary weighing memory 14 is changed to a regular time (see the right half of FIG. 6) based on the elapsed time from the power recovery. Restore. At this time, 2 kWh not yet stored in the temporary weighing memory 14 from 8:05 to 8:11 is added and weighed in the daytime time period, which is the time period in which the response time was obtained.

Within the restored time, the time zone division time period (0
7:00), the measurement total value on the front side (up to 24 minutes) of the time unit frame including this time period is transferred to the night time zone, and the rear side (elapsed time) of the time unit frame including the time period is included. (From 26 minutes to 90 minutes) during the daytime. Then, the weighed value of the time unit frame including the time period is proportionally divided according to the timetable ratio which has reached the time zone division time period of the time unit width, and is added to the day and night time zones. In the example of FIG. 6, the power is 2 kWh in the unit of 2 minutes, and the time zone division time limit (7:00
Since the minute) is intermediate, 1 kWh is added to daytime and 1 kWh is added to nighttime. Similarly, in the case of a unit of 10 minutes, in the case of a unit of one hour, distribution is made proportionally according to a timetable ratio that has reached a time zone division time limit.

The method of distributing time-restored metric values according to the second embodiment is suitable for a watt-hour meter installed in a consumer who uses a relatively large amount of power, and the storage capacity of the temporary weighing memory 14 does not need to be increased.

[0026]

As described above, according to the present invention, the current time is obtained by communication from the meter reading computer at the time of power recovery, and the measured value from the time of power recovery is calculated based on the current time. Since the clocks are allocated to the respective bands, a clock unit with a backup is not required even in the event of a power outage, and an inexpensive hourly power metering device excellent in maintainability can be provided.

Further, the capacity of the temporary weighing memory can be suppressed by devising the method of the temporary weighing memory according to the customer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a time-zone-specific power amount measuring device and an automatic meter reading system according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart illustrating the operation of the first embodiment.

FIG. 3 is a flowchart for distributing a temporary metered value after power recovery from a power outage to a normal time zone in the hourly power amount metering device of the first embodiment.

FIG. 4 is a schematic example of a temporary weighing memory according to the first embodiment;

FIG. 5 is a flowchart for distributing a temporary metered value after power recovery from a power failure to a normal time zone in the hourly power amount metering device according to Embodiment 2 of the present invention.

FIG. 6 is a schematic diagram illustrating a temporary weighing memory according to a second embodiment;

FIG. 7 is a block diagram showing a conventional electronic watt-hour meter.

[Explanation of symbols]

1 electric energy frequency conversion circuit, 2 microcomputer, 3 display, 10
Electronic meter watt hour meter, 11 power failure detection circuit,
12 Clock section, 13 Non-volatile memory, 14 Temporary weighing memory, 15 Communication control section, 17 Power supply section, 20 Automatic meter reading host computer, 21 Communication line.

Claims (5)

[Claims] 1. A method for measuring the amount of electric power used for each time period and transmitting the measured amount of electric power to an external computer for meter reading via a communication line, wherein the electric energy meter stores the measured value before the power failure. At the same time, after the power is restored, the current time information is requested from the meter reading computer. At the time of receiving, the normal time is obtained from the elapsed time of the temporary weighing, the temporary weighing value is allocated to the power amount for each predetermined time zone, and added to the weighing value before the power failure, Another power metering method. 2. An hourly electric energy metering device connected to an external meter reading computer via a communication line, means for storing a metered value before a power failure, and a current time stored in said meter reading computer upon power recovery. Means for inquiring, and a temporary weighing memory for temporarily measuring and storing the amount of electric power along with elapsed time information from power recovery to the current time answer, and based on the answer time from the meter reading computer, Obtain a provisional weighing value corresponding to the time information of the regular time from the elapsed time information of the provisional weighing memory, and distribute the provisional weighing value according to each predetermined time zone according to a predetermined time zone weighing switching time, An hourly electric energy metering device characterized in that it is added to a metered value stored before a power failure. 3. The power meter according to claim 2, wherein the temporary metering memory is configured to store elapsed time information for each carry of an arbitrary unit value of the power metering value. Weighing device. 4. The meter according to claim 2, wherein the temporary metering memory is configured to store a temporary metered value of the electric energy for each unit time of the elapsed time. 5. The temporary weighing memory according to claim 4, wherein the temporary weighing memory is configured to store the temporary weighing value by changing a unit time width according to an elapsed time from the power recovery. Power metering device.