JP5094073B2 - Electricity meter - Google Patents

Description

  The present invention relates to a watt-hour meter that measures the amount of power used.

In the power supply from the power company to the customer, events such as (1) instantaneous voltage drop, (2) power failure (power company), (3) normal voltage and supply current 0 (zero) may occur. “Instantaneous voltage drop” means that the voltage drops momentarily due to a surge such as lightning, but the voltage drops instantaneously. “Power failure (electric power company)” “Normal voltage and supply current 0 (zero)” means that power can be sent from the power company, but no power is supplied, that is, the indoor breaker is cut off. It is in a state of not using it.
JP 2001-255344 A JP 2004-340857 A

  If you are at home, you can tell if there is a power outage, but if you have reset your video or computer after you left home, you may want to know when a power outage occurs and when it returns due to a program. In addition, when there is a power outage after returning home, there is a case where it is desired to know when the power outage occurs and how much power outage occurs due to the refrigerator. Of the above events (1) to (3), in the case of (1) and (2), it can be understood by making an inquiry to the electric power company, but it takes time to make an inquiry, and the electric power company also takes time to investigate and answer. In the case of (3), it can be understood by looking at the indoor breaker, but it is the actual situation that power consumers are not very aware of the indoor breaker. I have noticed.

  Then, an object of this invention is to provide the watt-hour meter which a user can grasp | ascertain the condition of an electric power supply actively by showing the information about an electric power supply condition.

The watt-hour meter according to the present invention includes a current measuring unit that measures a current value of an electric circuit to be measured, a voltage measuring unit that measures a voltage value of the electric circuit to be measured, a clock unit that measures the current time, and the current Obtaining the current value measured by the measurement unit and the voltage value measured by the voltage measurement unit, and determining the power supply abnormality in the electric circuit to be measured based on the acquired current value and voltage value A microcomputer that determines the return of abnormality in the power supply based on the current value and the voltage value, and acquires the current time indicated by the clock unit when the determination is performed as the occurrence time of the determined event; A display unit that displays the determination result of the power supply status by the microcomputer in association with the occurrence time acquired by the microcomputer Comprises blackout and compensation device for compensating the operation of the microcomputer of the power failure by supplying a drive power during a power outage to the microcomputer, the microcomputer, the abnormality determination of the power supply, power is not supplied "power failure" And “instantaneous voltage drop” in which the voltage decreases instantaneously and “voltage normal and supply current 0” in which the voltage is normal but current is not supplied. Are divided into “power failure”, “instantaneous voltage drop”, “normal voltage and supply current 0”, and “return”.

  According to the present invention, the occurrence of the above events (1) to (3) and the event occurred easily at the home of the consumer (user) in the watt hour meter using the conventional power metering function. You can know the date and time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 shows a configuration of a watt-hour meter according to an embodiment of the present invention. The watt hour meter includes an electric energy frequency conversion circuit 101, a voltage measurement circuit 103, a current measurement circuit 102, a waveform shaping circuit 104, a clock unit 105, a microcomputer 107, a memory 108, a display unit 109, A power failure compensation device 110 and a power supply circuit 111 are provided. This watt-hour meter displays a power measurement value of an electric circuit to be measured (not shown) connected to a commercial power source, and also displays a power supply status in the electric circuit to be measured.

  The power amount frequency conversion circuit 101 is a V / F conversion circuit that takes in the current I and the voltage V of the electric circuit to be measured and converts them into a frequency signal proportional to the power amount. The current measurement circuit 102 measures the current value of the current I taken into the power amount frequency conversion circuit 101. The voltage measurement circuit 103 measures the voltage value of the voltage V taken into the power amount frequency conversion circuit 101. The waveform shaping circuit 104 (correction reference signal generation circuit) generates a correction reference signal for the clock unit 105 (timer) based on the zero crossing of the AC frequency of the electric circuit to be measured. The clock unit 105 measures the time, and the time measured by the clock unit 105 is set so that the time coincides with the standard time, and is corrected by the correction reference signal from the waveform shaping circuit 104.

  The microcomputer 107 organizes the frequency signal from the power amount frequency conversion circuit 101 into a power metric value and outputs it to the display unit 109. Further, the microcomputer 107 acquires the current value measured by the current measurement circuit 102 and the voltage value measured by the voltage measurement circuit 103 at regular intervals (for example, according to the time measured by the clock unit). Stored in the RAM. For example, the microcomputer 107 has a built-in RAM, acquires a current value and a voltage value three times per second, and records the acquired current value and voltage value as a set in its own RAM. When a new current value and voltage value set is recorded in the RAM, the oldest current value and voltage value set among the three sets already recorded in the RAM is discarded. That is, in the RAM, when a set of current values and voltage values acquired at the current time is newly stored, the set of current values and voltage values acquired one second before the current time is discarded. In other words, the RAM has a total of 3 sets of current value and voltage values acquired at the present time and current value and voltage value sets (two sets here) acquired from the current time to 1 second before. Stores the set.

  Further, the microcomputer 107 determines an abnormality in the power supply in the electric circuit to be measured or a return from the abnormality in the power supply based on the current value acquired from the current measurement circuit 102 and the voltage value acquired from the voltage measurement circuit 103. In accordance with the determination result, the microcomputer 107 outputs the current value and the voltage value stored in its own RAM to the memory 108. Further, according to the determination result, the microcomputer 107 determines “determination result” indicating the determined event, “occurrence time” indicating the time when the event occurred, “minimum voltage value”, and “current one second before” Power status information indicating “value” or the like is output to the display unit 109.

  The display unit 109 displays the power measurement value from the microcomputer 107 and the power status information.

  The power failure compensation device 110 is, for example, a battery for power failure compensation. The power supply circuit 111 is a power supply circuit that operates so as to supply drive power from the power failure compensation device 110 to the microcomputer 107, the clock unit 105, and the like in the event of a power failure.

<Operation>
Next, the operation of the watt-hour meter shown in FIG. 1 will be described.

[Step ST101]
First, the current measurement circuit 102 measures a current value, and the voltage measurement circuit 103 measures a voltage value. The microcomputer 107 acquires the current value measured by the current measurement circuit 102 and the voltage value measured by the voltage measurement circuit 103 at a constant cycle (here, three times per second) and stores them in its own RAM. The RAM of the microcomputer 107 sets the current value and voltage value acquired by the microcomputer 107 in this step ST101, and the current value and voltage value set already acquired one second before the present time (here Then, 2 sets) are stored.

[Step ST102]
Next, the microcomputer 107 determines whether or not an abnormal state flag indicating whether or not the power supply in the electric circuit to be measured is in an abnormal state is ON. When the abnormal state flag is OFF, the process proceeds to step ST103, and when the abnormal state flag is ON, the process proceeds to step ST111.

[Step ST103]
Next, the microcomputer 107 determines whether or not the voltage value acquired in step ST101 is lower than a first voltage level (in this case, 90 V) indicating that the voltage is abnormal. If the voltage value is lower than 90V, the process proceeds to step ST104, and if not, the process proceeds to step ST107.

[Step ST104]
Next, the microcomputer 107 obtains a set of current values and voltage values recorded in the RAM (a set of voltage values and current values determined to be lower than 90 V, and this set of voltage values and current values). The current value and voltage value set (two sets) acquired from 1 hour before 1 hour is output to the memory 108.

  Next, the microcomputer 107 outputs the current value measured by the current measurement circuit 102 and the voltage value measured by the voltage measurement circuit 103 for a certain cycle (here, 3 times per second) from the present time to 1 second later. Times) and store it in its own RAM. Then, the microcomputer determines whether or not the voltage value acquired between the present time and one second later is a second voltage level (in this case, 0 V) indicating a power failure state. If the voltage value is 0V, the process proceeds to step ST105, and if not, the process proceeds to step ST106.

[Step ST105]
Next, the microcomputer 107 determines that the event occurring in the electric circuit to be measured is “power failure (electric power company)” and acquires the current time counted by the clock unit 105 as “occurrence time”. Next, the microcomputer 107 reads the current value of the set of current value and voltage value recorded in the memory 108 as “current value 1 second before”. Then, the microcomputer 107, together with the electric power measurement value organized based on the frequency signal from the electric energy frequency conversion circuit 101, “judgment result (power failure (electric power company))”, “occurrence time”, and “current one second before” Power status information indicating “value” is output to the display unit 109. Next, the process proceeds to step ST109.

[Step ST106]
On the other hand, when it is determined in step ST104 that the voltage value is not the second voltage level (here, 0 V), the microcomputer 107 determines that the event occurring in the electric circuit to be measured is “instantaneous voltage drop”. The current time measured by the clock unit 105 is acquired as “occurrence time”. Next, the microcomputer 107 calculates the lowest voltage value as the “lowest voltage value” among the voltage values acquired in step ST <b> 104 (voltage values acquired from the present time until one second later). Further, the microcomputer 107 reads the current value of the set of current value and voltage value recorded in the memory 108 as “current value one second before”. Then, the microcomputer 107, together with the electric power measurement value organized based on the frequency signal from the electric energy frequency conversion circuit 101, “judgment result (instantaneous voltage drop)”, “occurrence time”, “minimum voltage value” and “1” The power status information indicating “current value before second” is displayed on the display unit 109. Next, the process proceeds to step ST109.

[Step ST107]
On the other hand, when it is determined in step ST103 that the voltage value is equal to or higher than the first voltage level (90 V in this case), the microcomputer 107 determines whether or not the current value acquired in step ST101 is 0A. If the current value is 0 A, the process proceeds to step ST108. If not, it is determined as “no abnormality” and the process proceeds to step ST101.

[Step ST108]
Next, the microcomputer 107 determines that the event occurring in the electric circuit to be measured is “normal voltage and supply current 0”, and acquires the current time counted by the clock unit 105 as “occurrence time”. . Next, the microcomputer 107 shows a power status indicating “judgment result (normal voltage and supply current 0)” and “occurrence time” together with a power measurement value organized based on the frequency signal from the power frequency conversion circuit 101. Information is output to the display unit 109. Next, the process proceeds to step ST109.

[Step ST109]
When the determination of the event by the microcomputer 107 is completed in step ST105, ST106, or ST108, the display unit 109 displays the power measurement value and the power status information from the microcomputer 107 (see FIG. 3).

  Here, when the determination result shown in the power status information is “power failure (electric power company)”, “power failure value (electric power company)” is displayed on the display unit 109 as an event together with the “electric power measurement value”. Then, “occurrence time” and “current value one second before” are displayed.

  When the determination result indicated in the power status information is “instantaneous voltage drop”, the display unit 109 displays “instantaneous voltage drop” as an event together with “measured power value”, and “occurrence time” ”,“ Minimum voltage value ”, and“ Current value 1 second before ”are displayed.

  Further, when the determination result indicated in the power status information is “normal voltage and supply current 0”, the display unit 109 displays “normal voltage and supply current 0” as an event together with “electric power measurement value”. And “occurrence time” is displayed.

[Step ST110]
Next, when the microcomputer 107 outputs the power status information to the display unit 109 in step ST105, ST106, or ST108, the microcomputer 107 turns on the abnormal state flag. Next, the process proceeds to step ST101.

[Step ST111]
On the other hand, when determining that the abnormal state flag is ON in step ST102, the microcomputer 107 determines whether or not the voltage value acquired in step ST101 is larger than 90V. If the voltage value is greater than 90V, the process proceeds to step ST112, and if not, the process proceeds to step ST101.

[Step ST112]
Next, the microcomputer 107 determines that the power supply in the electric circuit to be weighed has “returned” to the normal state, and acquires the current time counted by the clock unit 105 as “occurrence time (return time)”. . Next, the microcomputer 107 displays power status information indicating “judgment result (return)” and “occurrence time” together with a power measurement value organized based on the frequency signal from the power frequency conversion circuit 101. Output to.

[Step ST113]
Next, when receiving the power measurement value and the power status information from the microcomputer 107, the display unit 109 displays “return” as an event and “occurrence time” together with the “power measurement value”.

[Step ST114]
Next, when the microcomputer 107 outputs the power status information to the display unit 109 in step ST113, the microcomputer 107 turns off the abnormal state flag. Next, the process proceeds to step ST101.

<Effect>
As described above, “judgment results (events)” and “occurrence time” are displayed on the display unit of the watt-hour meter, so that not only the meter readers and maintenance staff of the electric power company but also the users actively The power supply status can be grasped. For example, when a power outage occurs while the user is away, it is possible to easily grasp at what time the power outage occurred by referring to the display of the watt hour meter. According to this, if the power is restored at the moment, but there was a power outage before and the video or personal computer was reset and the program recording was not performed normally, it is possible to grasp the time period when the recording was not performed. . Alternatively, when the power is still out and the refrigerator has stopped, it is possible to know how long the refrigerator has stopped.

  In addition, since the display section displays “judgment result (event)” as well as “minimum voltage value” and “current value 1 second before”, the power company that received the inquiry from the user shows the power supply status of the user's home. It is possible to quickly grasp, and it is possible to quickly investigate the power supply status and reply to the user.

It is a block diagram which shows the structure of the watt-hour meter by embodiment of this invention. 3 is a flowchart for explaining an operation by the watt-hour meter shown in FIG. 1. It is a figure which shows an example of the display of a watt-hour meter.

DESCRIPTION OF SYMBOLS 101 Electric energy frequency conversion circuit 102 Electric power measurement circuit 103 Voltage measurement circuit 104 Waveform shaping circuit 105 Clock part 107 Microcomputer 108 Memory 109 Display part 110 Power failure compensation apparatus 111 Power supply circuit

Claims (3)

A current measuring unit for measuring the current value of the electric circuit to be weighed;
A voltage measuring unit for measuring a voltage value of the circuit to be measured;
A clock section that counts the current time,
While obtaining the current value measured by the current measuring unit and the voltage value measured by the voltage measuring unit, and determining an abnormality in power supply in the electric circuit to be measured based on the acquired current value and voltage value, A microcomputer that determines whether or not an abnormality has occurred in power supply based on the acquired current value and voltage value, and acquires the current time indicated by the clock unit when the determination is executed as the occurrence time of the determined event When,
A display unit for displaying the determination result of the power supply status by the microcomputer in association with the occurrence time acquired by the microcomputer;
A power failure compensation device that compensates for the operation of the microcomputer during a power failure by supplying driving power to the microcomputer during a power failure ;
The microcomputer is
The power supply abnormality determination includes “power failure” in which power is not supplied, “instantaneous voltage drop” in which the voltage decreases instantaneously, “voltage normal and supply current 0” in which the current is not supplied although the voltage is normal, The judgment is divided into
The watt-hour meter characterized in that the display unit displays the determination result separately for "power failure", "instantaneous voltage drop", "normal voltage and supply current 0", and "return" . In claim 1 ,
The microcomputer is
When an abnormal state flag indicating whether an abnormality has occurred in power supply in the electric circuit to be measured is OFF and the voltage value acquired at the present time is lower than a first voltage level indicating a voltage abnormality When it is determined and the voltage value acquired between the present time and a predetermined time later is the second voltage level indicating a power failure state, the event occurring in the electric circuit to be measured is “power failure” And turn on the abnormal state flag,
It is determined that the abnormal state flag is OFF, and the voltage value acquired at the present time is lower than the first voltage level, and the voltage value acquired between the current time and a predetermined time later is If it is determined that it is not the second voltage level, it is determined that the event occurring in the electric circuit to be weighed is “instantaneous power reduction”, and the abnormal state flag is turned ON,
When it is determined that the abnormal state flag is OFF, the voltage value acquired at the current time is higher than the first voltage level, and the current value acquired at the current time is 0 A , It is determined that the event that has occurred in the electric circuit to be measured is “normal voltage and supply current 0”, and the abnormal state flag is turned ON,
When it is determined that the abnormal state flag is ON and the voltage value acquired at the present time is higher than the first voltage level, the power supply in the to-be-measured electric circuit is “returned” to the normal state. A watt-hour meter characterized by turning off the abnormal state flag while determining. In claim 2 ,
The microcomputer is
While recording the current value acquired from the current measuring unit and the voltage value acquired from the voltage measuring unit at the current time, the current value and voltage value acquired from the current time to a predetermined time before are also recorded. ,
When it is determined that the event that has occurred in the electrical circuit to be weighed is a "power failure", the recorded current value is output as a current value a predetermined time ago,
When it is determined that the event occurring in the electric circuit to be weighed is “instantaneous power reduction”, the lowest voltage value among the voltage values acquired between the current time and a predetermined time later is output as the lowest voltage value,
The display unit
The determination result of the event by the microcomputer and the occurrence time acquired by the microcomputer are displayed, and the current value and the minimum voltage value from the microcomputer before the predetermined time are associated with the determination result of the power supply status A watt hour meter characterized by being displayed.

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