JP4230897B2 - Electronic energy meter - Google Patents

Description

  The present invention relates to an electronic watt-hour meter that measures the amount of electricity used, and more particularly to a technique for grasping the state of power usage.

  Conventionally, watt-hour meters are used to measure the power supplied to consumers. Conventionally, inductive watt hour meters have been used as such watt hour meters, but in recent years, electronic watt hour meters that have a long life due to the reduced mounting space and no mechanical moving parts have become widespread. It's getting on.

  FIG. 5 is a block diagram showing a configuration of a conventional electronic watt-hour meter installed in a general household. The electronic watt-hour meter 5 measures the power supplied from the power supply facility 1 to the indoor load 4 via the distribution line 2, input terminal 50, conductor 52, output terminal 51, and service breaker 6.

  The service breaker 6 operates when a current equal to or greater than the cutoff current determined by the current contract between the power company and the consumer flows from the power supply facility to the load, and forcibly cuts off the power supply.

  The electronic watt-hour meter 5 includes an input terminal 50, an output terminal 51, a conductor 52, a voltage detection unit 53, a current detection unit 54, a power calculation unit 55, a central calculation unit 56, and a display unit 57.

  The voltage detector 53 detects the voltage of the signal under measurement input from the input terminal 50. The voltage value representing the voltage detected by the voltage detection unit 53 is sent to the power calculation unit 55. The current detector 54 detects the current of the signal under measurement input from the input terminal 50. A current value representing the current detected by the current detector 54 is sent to the power calculator 55.

  The power calculator 55 multiplies the voltage value sent from the voltage detector 53 by the current value sent from the current detector 54 to calculate power. The power value representing the power calculated by the power calculation unit 55 is sent to the central calculation unit 56. The central calculation unit 56 cumulatively adds the power values sent from the power calculation unit 55 and sends them to the display unit 57. As a result, the used accumulated power amount is displayed on the display unit 57.

As a related technique, Patent Document 1 discloses an electronic watt-hour meter with an overcurrent alarm function. This electronic watt-hour meter with an overcurrent alarm function is an electronic watt-hour meter that detects load voltage and load current and measures power consumption, compares the detected load current with a reference value, and the load current is When larger than the reference value, the comparator means for generating the output signal, the carrier signal transmitter means for transmitting the carrier signal to the distribution line in response to the output signal from the comparator means, the carrier signal transmitting means connected to the distribution line, An alarm generating unit that receives a carrier signal transmitted to the distribution line and generates an alarm, and a blocking filter that prevents the carrier signal transmitted from the carrier transmission unit to the distribution line from leaking to the outside.
Japanese Patent Laid-Open No. 04-168937

  By the way, in recent years, electrical appliances used in ordinary households have become mainstream with built-in clocks, and household personal computers have been widely used. Therefore, the power failure caused by the operation of the service breaker hinders the continuous operation of electrical appliances and home personal computers, which is very inconvenient for consumers.

  In addition, since the current capacity of the service breaker is up to 60A, the contract current can be determined by the distribution board equipment in the home when contracting more current, but most of them are in the home. The contract cannot be changed without notification.

  In addition, in general households that are consumers of low-voltage power, if the contract current changes due to changes in the contract current due to changes in electrical appliances or due to moving, etc., construction to replace the service breaker is necessary. Are inefficient and uneconomical. As described above, various problems due to the existence of the service breaker have occurred.

  The present invention has been made in order to solve the above-described problems, and the problems thereof are an electronic system that can reduce power equipment and construction costs, and can easily determine an appropriate contract current magnitude. It is to provide a watt-hour meter.

In order to solve the above problems, an electronic watt-hour meter according to the present invention calculates a power based on a voltage and a current supplied from a power supply facility to a load, and is calculated by the power calculation unit. The power consumption is obtained by accumulating the obtained power, and the demand power, which is an average value of the power calculated by the power calculation unit in the predetermined time interval, is obtained for each predetermined time interval . A central processing unit that determines which of the sections divided into a plurality of stages according to the size, and a display corresponding to the divided section of the demand power classification determined by the central processing unit is blinked. And a demand power display unit for displaying by the above.

  In addition, the central processing unit further stores, as a maximum demand power category, a category to which the maximum value of demand power obtained at each predetermined time interval belongs, and the demand power display unit further stores in the central processing unit. It is characterized by displaying the maximum demand electric power category.

  According to the present invention, it is configured to measure the demand power, which is a usage amount for each predetermined time interval set in advance, and to display the current category and the past maximum demand power category of the demand power. Even without limiting the power supply, it is possible to supply power with an appropriate contract current, and the service breaker can be eliminated. As a result, electric power can be supplied efficiently and economically by reducing power equipment and construction costs.

  ADVANTAGE OF THE INVENTION According to this invention, an electric watt-hour meter which can reduce electric power installation and construction expense, and can judge the magnitude | size of an appropriate contract current easily can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an electronic watt-hour meter according to the first embodiment of the present invention. The electronic watt-hour meter 3 takes in a signal under measurement supplied from the power supply facility 1 via the distribution line 2 from the input terminal 30 and measures the amount of power used. The signal under measurement is supplied to the indoor load 4 via the input terminal 30, the conductor 32, and the output terminal 31.

  The electronic watt-hour meter 3 includes an input terminal 30, an output terminal 31, a conductor 32, a voltage detection unit 33, a current detection unit 34, a power calculation unit 35, a central calculation unit 36, a setting unit 37, a clock mechanism 38, and a power amount display. The unit 39 and the demand power display unit 40 are configured.

  The voltage detector 33 detects the voltage of the signal under measurement input from the input terminal 30. The voltage value representing the voltage detected by the voltage detector 33 is sent to the power calculator 35. The current detector 34 detects the current of the signal under measurement input from the input terminal 30. A current value representing the current detected by the current detector 34 is sent to the power calculator 35.

  The power calculator 35 multiplies the voltage value sent from the voltage detector 33 by the current value sent from the current detector 34 to calculate power. The power value representing the power calculated by the power calculation unit 35 is sent to the central calculation unit 36.

  The central processing unit 36 is composed of, for example, a microcomputer. The central processing unit 36 calculates the power amount and the demand power based on the power value sent from the power calculation unit 35, and sends it to the power amount display unit 39 and the demand power display unit 40, respectively. Here, the amount of power refers to the amount of power consumed by the consumer (unit: kWh). This amount of power is obtained by accumulatively adding power values sent from the power calculation unit 35. The demand power is an average value (unit: kW) of power in a short time such as 15 minutes or 30 minutes. This demand power is obtained by cumulatively adding the power value sent from the power calculation unit 35 for a predetermined time and dividing the result of the cumulative addition by the predetermined time.

  The central processing unit 36 stores the maximum demand power in a memory (not shown). The maximum demand power means the maximum value of demand power calculated by the central processing unit 36 in the past. Further, the central processing unit 36 determines which of the plurality of categories the calculated demand power belongs to, and stores the category to which the maximum value of the demand power belongs in the memory as the maximum demand power category. Details of the processing performed by the central processing unit 36 will be described later with reference to a flowchart.

  The setting unit 37 is used to set various data in the central processing unit 36. Specifically, the setting unit 37 deletes the maximum demand power section stored in a memory (not shown), sets a predetermined time (demand power measurement time) for calculating the demand power and the demand power section, Used to set the time. The initialization means of the present invention is configured by this setting unit 37.

  The clock mechanism 38 keeps time. The clock mechanism 38 is used to determine a time zone for calculating demand power and demand power classification. In addition, when a contract for distinguishing between daytime power and nighttime power is made between a consumer and an electric power company, it is used to determine a daytime time zone and a night time zone. The time counted by the clock mechanism 38 is sent to the central processing unit 36 and the electric energy display unit 39.

  As shown in FIG. 2, the power amount display unit 39 is composed of, for example, 7-segment LEDs, and displays the integrated power amount calculated by the central processing unit 36. Moreover, this electric energy display part 39 displays the present time slot | zone, when the contract which distinguishes and uses daytime electric power and nighttime electric power is made between a consumer and an electric power company. In this case, the daytime time zone (for example, 7:00 to 23:00) is displayed as “1”, and the nighttime zone (for example, from 23:00 to 7:00) is displayed as “2”. Further, the power amount display unit 39 displays the current time sent from the clock mechanism 38.

  The demand power display unit 40 displays the demand power category obtained by the central processing unit 36 or the maximum demand power category stored in the central processing unit 36. Specifically, the demand power display unit 40 includes seven sections corresponding to seven sections of 1.0 kW, 1.5 kW, 2.0 kW, 3.0 kW, 4.0 kW, 5.0 kW, and 6.0 kW, respectively. It consists of LEDs. The demand power display unit 40 displays the current demand power classification by blinking any of the seven LEDs. The demand power display unit 40 displays the maximum demand power category by lighting any one of the seven LEDs.

  Next, the operation of the electronic watt-hour meter according to the first embodiment of the present invention configured as described above will be described with reference to the flowchart shown in FIG. The description will be given with reference.

  First, the power value is captured (step S10). In other words, the central calculation unit 36 takes in the power value from the power calculation unit 35. Next, the power value is cumulatively added (integrated) to the power amount counter (step S11). The power amount counter is a counter provided in a memory (not shown) included in the central processing unit 36, and is used as a power amount integration counter.

  Next, an electric energy display is performed (step S12). That is, the central processing unit 36 sends the content of the power amount counter to the power amount display unit 39. As a result, as shown in FIG. 2, the accumulated power consumption up to the present time is displayed on the power amount display unit 39.

  Next, the power value captured in step S10 is integrated into the demand power counter (step S13). The demand power counter is a counter provided in a memory (not shown) included in the central processing unit 36, and is used as a work counter for calculating demand power.

  Next, it is examined whether or not a predetermined time (demand power measurement time) for calculating demand power has elapsed (step S14). That is, the central processing unit 36 compares the time taken in and stored from the clock mechanism 38 during the previous demand power calculation process with the time taken this time from the clock mechanism 38, and measures demand power provided in a memory (not shown). It is checked whether or not a predetermined time (for example, 30 minutes) stored in the time register has elapsed. If it is determined in step S14 that the predetermined time has not elapsed, the power demand process (steps S15 to S19) is skipped.

  If it is determined in step S14 that the predetermined time has elapsed, the power demand process is executed. In this demand power processing, first, demand power is calculated (step S15). Specifically, the content of the demand power counter is divided by a predetermined time (for example, 30 minutes), and the average value of the power in the predetermined time is obtained. This obtained average value is demand power.

  Next, the obtained demand power category is calculated (step S16). Specifically, the required power demand is 1.0 kW to less than 1.5 kW, 1.5 kW to less than 2.0 kW, 2.0 kW to less than 3.0 kW, 3.0 kW to less than 4.0 kW. It is determined which of the classifications 0 kW to less than 5.0 kW, 5.0 kW to less than 6.0 kW, and 6.0 kW or more.

  Next, the demand power classification obtained in step S16 is displayed blinking (step S17). That is, the central processing unit 36 sends a signal for blinking the LED corresponding to the demand power category obtained in step S16 to the demand power display unit 40. As a result, the LED corresponding to the current demand power category of the demand power display unit 40 blinks.

  Next, it is investigated whether demand power is the maximum in the past (step S18). That is, the central processing unit 36 checks whether or not the demand power obtained in step S15 is larger than the maximum demand power stored in the maximum demand power register provided in a memory (not shown).

  If it is determined in this step S18 that the demand power is the maximum in the past, the lighting display of the maximum demand power classification is performed (step S19). That is, the central processing unit 36 sends to the demand power display unit 40 a signal for turning on the LED corresponding to the category obtained in step S16. Thereby, LED corresponding to the maximum demand power classification of the demand power display part 40 lights. If it is determined in step S18 that the demand power is not the maximum in the past, the process in step S19 is skipped.

  Through the above demand power processing, the customer and the power company can know the magnitude of the power currently used by looking at the blinking LED on the demand power display section 40, and look at the lighted LED. Thus, the past maximum demand power can be known. As a result, the customer and the power company can determine the contract current based on this, so it is possible to supply power with the correct contract current without limiting the power supplied by the service breaker. become.

  Next, it is checked whether or not there is an initialization command (step S20). That is, the central processing unit 36 checks whether an initialization command is sent from the setting unit 37. When it is determined that there is an initialization command, the maximum demand power category is cleared (step S21). Specifically, the contents of the maximum demand power counter are cleared. With this configuration, since the data representing the past maximum demand power category stored in the maximum demand power counter can be cleared by a command from the operation of the setting unit 37, the electronic watt-hour meter can be replaced when the contract is changed. Can be eliminated.

  Next, it is checked whether or not there is a time setting command (step S22). That is, the central processing unit 36 checks whether a time setting command is sent from the setting unit 37. If it is determined that there is a time setting command, a time setting process is performed (step S23). In this time setting process, the central processing unit 36 sends the time data sent from the setting unit 37 to the clock mechanism 38. As a result, the clock mechanism 38 resumes counting from the time designated by the time data.

  Next, it is checked whether or not there is a time change command (step S24). That is, the central processing unit 36 checks whether a time change command is sent from the setting unit 37. When it is determined that there is a time change command, a process for changing the demand power measurement time is performed (step S25). In the process for changing the demand power measurement time, the central processing unit 36 stores the time data sent from the setting unit 37 in the demand power measurement time register. As a result, the subsequent power demand processing is executed at the time interval stored in the demand power measurement time register.

  Thereafter, the sequence returns to step S10, and the same processing is repeated thereafter. If it is determined in step S24 that there is no time change command, the sequence returns to step S10, and the same processing is repeated thereafter.

  As described above, according to the electronic watt-hour meter according to the first embodiment, since it is configured to display the demand power category indicating the current usage and the past maximum demand power category, the consumer And the electric power company can determine the contract current based on this. Accordingly, since it is possible to supply electric power with an appropriate contract current level without limiting the electric power supplied by the service breaker, the service breaker can be eliminated. As a result, power equipment and construction costs can be reduced, and efficient use of resources can be achieved. In addition, it is possible to achieve an economy by suppressing an increase in investment of power supply facilities.

  The second embodiment of the present invention is configured to stop the power demand process depending on the time zone. There may be a case where a contract between the customer and the electric power company is made for different power charges in the daytime and nighttime periods. In this case, it is preferable to encourage power consumption during night hours.

  Since the configuration of the electronic watt-hour meter according to the second embodiment is the same as the configuration of the first embodiment already described with reference to FIGS. 1 and 2, the description thereof will be omitted.

  Next, the operation of the electronic watt-hour meter according to the second embodiment of the present invention will be described with reference to the flowchart shown in FIG. In the following description, the same reference numerals as those in the first embodiment are assigned to the same processing portions as those in the first embodiment (see FIG. 3), and description thereof will be omitted or simplified.

  Incorporation of power values shown in the flowchart of FIG. 4 (step S10), integration of power values into a power amount counter (step S11), power amount display (step S12), and integration of power values into a demand power counter (step S13) These processes are the same as those in the first embodiment.

  When the above processing ends, it is checked whether or not it is the measurement time zone (step S30). Whether it is a measurement time zone can be determined based on whether it is a daytime time zone agreed in advance between a consumer and an electric power company, for example, whether it is between 7 o'clock and 23 o'clock. Alternatively, when a contract is made between the customer and the power company to use midnight power, the daytime time zone (for example, 7:00 to 23:00), that is, “1” as the time zone is displayed on the power amount display unit 39. "Can be determined by whether or not. The central processing unit 36 reads the current time from the clock mechanism 38 and determines whether it is a measurement time zone.

  If it is determined in step S30 that it is the measurement time zone, the power demand processing in steps S14 to S19 is executed, and if it is determined that it is not the measurement time zone, the power demand processing is skipped. The subsequent processing is the same as the processing in the first embodiment.

  As described above, according to the electronic watt-hour meter according to the second embodiment of the present invention, the power demand process is executed only when the current time is the measurement time zone, that is, the daytime time zone. Therefore, the power demand processing is not performed during the night time. Therefore, even if a large amount of power is used at night, it is not reflected in the power contract between the customer and the power company, so that more power can be used at night. As a result, it is possible to promote the suppression of electric power used in the daytime, contribute to the leveling of electric power supply, and supply electric power efficiently and economically.

  The first and second embodiments described above are configured to calculate demand power, display the current demand power category and the past maximum demand power category, and contribute to the power contract between the customer and the power company. However, it can be configured to contribute to a power contract between the customer and the power company based on the amount of electric power and the current value for a certain period of time.

  In the first and second embodiments described above, the power calculation unit 35 and the central calculation unit 36 are provided separately, but the function of the power calculation unit 35 is included in the central calculation unit 36. You can also. In this case, the multiplication of the voltage value sent from the voltage detection unit 33 and the current value sent from the current detection unit 34 can be performed by the central processing unit 36.

  Moreover, in 1st and 2nd embodiment mentioned above, although the electric energy display part 39 and the demand electric power display part 40 are provided separately, these should be integrated and displayed on the electric energy display part 39 The contents and the contents to be displayed on the demand power display unit 40 may be configured to be displayed in one display unit. According to this configuration, it is possible to simplify and reduce the structure of the electronic watt-hour meter.

  The maximum demand power category stored in the central processing unit 36 is cleared by sending an initialization command from the setting unit 37. However, a wired or wireless communication interface is connected to the electronic watt-hour meter. And clearing the maximum demand power category can be configured to be performed via the communication interface. According to this configuration, since it is not necessary to provide the setting unit 37 in the electronic watt-hour meter, the structure of the electronic watt-hour meter can be simplified and reduced in price.

  Further, the time setting of the electronic watt-hour meter and the setting of the demand power measurement time are configured by the setting unit 37, but the demand power measurement time is stored in advance in a memory (not shown) included in the central processing unit 36 as a fixed value. It can be set and set as an unsettable item.

  In particular, it can be applied to ordinary households who are consumers of low-voltage power.

It is a block diagram which shows the structure of the electronic watt-hour meter which concerns on the 1st and 2nd embodiment of this invention. It is an external appearance front view of the electronic watt-hour meter which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating operation | movement of the electronic watt-hour meter which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating operation | movement of the electronic watt-hour meter which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the conventional electronic watt-hour meter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power supply equipment 2 Distribution line 3 Electronic watt-hour meter 4 Load 30 Input terminal 31 Output terminal 32 Conductor 33 Voltage detection part 34 Current detection part 35 Power calculation part 36 Central calculation part 37 Setting part 38 Clock mechanism 39 Electric energy display part 40 Demand power display

Claims (6)

A power calculator that calculates power based on the voltage and current supplied to the load from the power supply facility;
The power calculated by the power calculation unit is cumulatively added to determine the amount of power, and the demand power that is an average value of the power calculated by the power calculation unit in a predetermined time interval is determined for each predetermined time interval, A central processing unit for determining which demand power belongs to which of a plurality of stages divided according to the magnitude of demand power ;
A demand power display unit that displays the demand power classification obtained by the central processing unit by blinking and displaying a display corresponding to the classified classification ;
An electronic watt-hour meter comprising: The central processing unit further stores, as a maximum demand power category, a category to which the maximum value of demand power required for each predetermined time interval belongs,
The electronic power meter according to claim 1, wherein the demand power display unit further displays a maximum demand power category stored in the central processing unit. The electronic watt-hour meter according to claim 2, further comprising initialization means for erasing the maximum demand power section stored in the central processing unit. The electronic watt-hour meter according to any one of claims 1 to 3, further comprising a setting unit that changes the predetermined time interval for obtaining the demand power classification. Further equipped with a clock mechanism for measuring time,
5. The electronic device according to claim 1, wherein the central processing unit calculates the demand power classification only while the timepiece mechanism indicates that it is in a predetermined time zone. Power meter.   The central processing unit is configured to cumulatively add the power calculated by the power calculation unit for each time zone to obtain an amount of power, and to determine whether the demand power category can be calculated for each time zone. The electronic watt-hour meter according to claim 1 or 2.

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