JP2010223628A - Watt-hour meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a watt-hour meter capable of informing a user of determination results as to whether there is a possibility of accumulated electric energy exceeding a target value, even when the user does not try to check it intentionally. <P>SOLUTION: An arithmetic processing unit 9 includes a target setting means 22 for setting target accumulated electric energy within a predetermined period and a determination means 23 for determining an alarm state in which there is a possibility of the accumulated electric energy exceeding the target accumulated electric energy at the termination of the predetermined period and a non-alarm state in which there is no possibility on the basis of the present accumulated electric energy and the target accumulated electric energy. A display block 3 includes an LED light-emitting display unit 20 apart from an electric energy display unit 10. The determination results of the determination means 23 as to whether there is a possibility of the accumulated electric energy exceeding the target accumulated electric energy are constantly informed through the light-emitting state of the light-emitting display unit 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a watt hour meter having a function of measuring and displaying the amount of power supplied to a load via a power line.

  Conventionally, as this type of watt-hour meter, measuring means for measuring the voltage and current supplied to the load, and obtaining the instantaneous power based on the measured instantaneous voltage value and instantaneous current value, There is provided a device provided with integration means for integrating (integrating) a predetermined period such as day and time to obtain an integrated electric energy (see, for example, Patent Document 1).

  The watt-hour meter described in Patent Document 1 includes a liquid crystal display as display means for displaying the integrated electric energy obtained by the integrating means. Therefore, the user can know the accumulated power amount of the current month, for example, by confirming the display content of the liquid crystal display, and can thereby grasp the approximate electricity bill for the current month.

  By the way, in recent years, interest in energy saving has increased, and accordingly, the electricity meter as described above is widely installed not only in places that consume relatively large power such as factories and office buildings, but also in general houses. It has come to be.

  Against this background, as a watt-hour meter, whether the user presets a target value for the integrated power amount for each predetermined period (for example, month), and is the integrated power amount expected to exceed the target value at the end of the predetermined period? A device having a function of displaying a determination result on whether or not to be displayed on a liquid crystal display together with the actual value of the integrated electric energy has been proposed. This type of watt-hour meter, for example, obtains a guide amount that is a measure of the integrated power amount from the target value to the present time, and uses the ratio of the actual value of the integrated power amount to the guide amount as a result of the determination, such as a percentage or a graph Is displayed. Therefore, by checking the judgment result displayed on the liquid crystal display, the user will try to save more power if the target value is expected to be exceeded, and if it is expected to be within the target value Appropriate judgments such as maintaining the current situation can be made. As a result, it becomes easier to achieve the goal of keeping the actual value of the integrated power amount within the target value, leading to energy saving.

Japanese Patent No. 3509585 (paragraph 0012-0015)

  However, in the watt-hour meter having the above-described configuration, the determination result as to whether or not the integrated power amount is expected to exceed the target value only when the user confirms the display content of the liquid crystal display. If the user does not see the display content of the liquid crystal display, the determination result is not transmitted to the user. Therefore, in order to fully utilize the watt-hour meter, the watt-hour meter is installed in a place that is easily accessible to the user's view, such as a living room wall in a house, and the watt-hour meter's liquid crystal display It is necessary to make a habit of frequently checking the display contents. In other words, when the user is requested to improve to further save power, it is effective to promptly inform the user of the determination result, and for this purpose, the display content of the liquid crystal display is frequently given to the user. Need to be confirmed.

  However, for users who are not interested in energy conservation in the first place, even if the watt hour meter enters the field of view frequently, the act of bothering the watt hour meter and checking the display contents of the liquid crystal display is troublesome. It is. As a result, the watt-hour meter with the above-described configuration may not be sufficiently utilized for such users even though it is particularly useful for users who are not interested in energy saving.

  It is possible to enlarge the liquid crystal display so that the user can recognize the display contents, but in this case, the cost associated with the liquid crystal display increases and the watt hour meter There are problems such as hindering cost reduction and losing the aesthetics of the room because the entire watt-hour meter is enlarged.

  The present invention has been made in view of the above-described reason, and communicates a determination result as to whether or not the accumulated power amount is expected to exceed a target value even to a user who does not intend to confirm intentionally. An object is to provide a watt-hour meter that can be used.

  The invention according to claim 1 is connected to measuring means for measuring voltage and current supplied to the load via the power line, and uses the instantaneous voltage value and instantaneous current value measured by the measuring means within the predetermined period. Integration means for determining the integrated power amount supplied to the power supply, a power amount indicator for displaying the integrated power amount calculated by the integration means, and a target setting means for setting a target value of the integrated power amount at the end of the predetermined period; Determining means for determining, based on a current integrated power amount and a target value, an alarm state in which the integrated power amount is expected to exceed the target value at the end of the predetermined period and a non-alarm state in which the integrated power amount is not expected to exceed the target value; The device includes a light emitting element provided separately from the power amount indicator, and a light emitting display unit that constantly emits light and notifies the determination result of the determination unit according to the light emission state.

  According to this configuration, the light emission display unit always notifies the determination result by the determination means about whether or not the integrated power amount is expected to exceed the target value at the end of the predetermined period, according to the light emission state. The determination result can be transmitted to a user who does not intentionally confirm the determination result. That is, since the light emitting display unit has a light emitting element provided separately from the power amount indicator, and constantly notifies the judgment result according to the light emission state, the user can calculate the integrated power displayed on the power amount indicator. Unlike the case of confirming the amount, the judgment result can be known only by looking at the light emitting display portion. Therefore, even if the user is not interested in energy saving, if the watt hour meter is installed in a place where the user can easily enter the field of view, the determination result can be reliably transmitted. As a result, the user makes an appropriate decision such as trying to save more power if the accumulated power amount is expected to exceed the target value, or maintaining the current state if the accumulated power amount is expected to be within the target value. This makes it easier to achieve the goal of keeping the actual value of the integrated power amount within the target value, and an effect that leads to energy saving can be expected. The notification based on the light emission state of the light emitting display unit includes, for example, a light emitting display unit configured with light emitting elements of a plurality of colors and a notification based on the light emitting color, and a light emitting display unit configured with a plurality of light emitting elements for light emission. Includes notifications based on the position or number of light emitting elements.

  According to a second aspect of the present invention, in the first aspect of the present invention, the determination means uses a determination threshold that increases with time from the start of the predetermined period and reaches the target value at the end of the predetermined period. As a result of comparing the integrated power amount and the determination threshold value, the alarm state is determined when the integrated power amount exceeds the determination threshold value.

  According to this configuration, the current determination threshold value is determined based on one target value, and the integrated power amount is determined at the end of the predetermined period by a simple process of comparing the determination threshold value and the current integrated power amount. Since it is possible to determine the alarm state that is expected to exceed the target value and the non-alarm state that is not expected to exceed the target value, the burden on the determination can be suppressed relatively lightly.

  According to a third aspect of the present invention, in the second aspect of the present invention, the non-alarm state is classified into a caution state and a margin state, and the determination means is set lower than the determination threshold and increases with time. As a result of comparing the current integrated power amount with the determination threshold value and the attention threshold value as a result of comparing the current integrated power amount with the determination threshold value and the attention threshold value, it is determined that the attention state is determined when the integrated power amount does not exceed the determination threshold value but exceeds the attention threshold value.

  According to this configuration, since the non-alarm state in which the integrated power amount is not expected to exceed the target value is further classified into a caution state and a margin state, the user can target the actual value of the integrated power amount. You can know in detail the current achievement status regarding the goal of staying within the value. Therefore, although it is expected that the integrated power amount does not exceed the target value, the user can make a finer determination such as paying attention not to increase the power consumption when it is determined to be in a caution state.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the light-emitting display unit includes a plurality of the light-emitting elements having different emission colors, and according to a determination result of the determination unit. The light emitting state is changed by switching light emitting elements to emit light.

  According to this configuration, the light emitting display unit informs the user of the determination result by the light emission color, so that the user can perform the above operation even from a position relatively far from the watt hour meter as long as the light from the light emitting display unit reaches. The judgment result can be recognized.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, an operation unit that receives an operation related to display contents of the power amount indicator, and the power amount indicator according to an operation state of the operation unit. Mode switching means for switching the operation mode, and the mode switching means is not displayed or displayed if the operation of the operation unit is not detected for a predetermined timer time or more while the electric energy indicator is operating in the normal mode. The operation mode is switched to a power saving mode in which power consumption is reduced by reducing screen brightness.

  According to this configuration, if the operation unit is not operated for more than the timer time, the power amount indicator is switched to the power saving mode. Therefore, compared to the case where the power amount indicator is always operated in the normal mode, the power amount indicator. Power consumption can be kept low.

  In the present invention, the determination result of the determination means that is determined whether or not the integrated power amount is expected to exceed the target value at the end of the predetermined period is always notified by the light emission state of the light emitting display unit. The judgment result can be communicated to a user who does not intend to confirm. Therefore, even for users who are not very interested in energy saving, if the watt-hour meter is installed in a place where it is easy to enter the field of view, the judgment result can be transmitted reliably, and the actual value of the integrated power consumption can be targeted. There is an advantage that it becomes easy to make the target achievement to be within the value, and as a result, it leads to energy saving.

It is a schematic block diagram which shows the structure of Embodiment 1 of this invention. It is a schematic perspective view same as the above. It is a flowchart which shows operation | movement same as the above. It is explanatory drawing of operation | movement same as the above. It is a flowchart which shows operation | movement same as the above.

(Embodiment 1)
As shown in FIG. 1, a watt-hour meter 1 according to the present embodiment includes a single-phase three-wire commercial power source (not shown), a limiter (not shown) including a current limiter, and a main breaker (not illustrated) including a conductive breaker. A measurement block 2 connected to the voltage lines L1 and L2 and the neutral line N connected via a relay terminal block (not shown) is provided. Further, the watt hour meter is formed on a separate substrate from the measurement block 2 and includes a display block 3 connected to the measurement block 2. The limiter is a breaker provided to limit the load current of the customer to a contract value or less with the electric power company. Between the main breaker and the relay terminal block, a plurality of branch circuits are connected between the voltage line L1 and the neutral line N and between the voltage line L2 and the neutral line N via a branch breaker. That is, power is supplied to the load via the branch breaker.

  The limiter, main breaker, branch breaker, and relay terminal block are housed in a distribution board (not shown), and the watt-hour meter 1 including the measurement block 2 and the display block 3 is installed indoors separately from the distribution board. Installed. In the present embodiment, it is assumed that the watt-hour meter 1 is installed in a general house, and the watt-hour meter 1 is installed at a position that can easily enter the user's view on the wall of an arbitrary room (for example, a living room).

  Further, the distribution board is provided with two current transformers CT1 and CT2 for detecting currents flowing through the voltage lines L1 and L2 between the limiter and the main breaker as measurement means. The measurement block 2 includes an instantaneous value (instantaneous current value) of the current detected by the current transformers CT1 and CT2 and a line voltage between the voltage line L1 and the neutral line N and between the voltage line L2 and the neutral line N. A measurement microcomputer 4 is provided for obtaining electric power using an instantaneous value (instantaneous voltage value). Here, the current detected by the current transformers CT1 and CT2 is input to the measurement microcomputer 4 as a current signal through the current processing circuit 5 that performs gain switching and bias application, and the line voltage is the voltage lines L1, L2 and The voltage is measured by the voltage processing circuit 6 which is a measuring means connected to the neutral wire N and performs operation amplification, phase shift adjustment, and bias application, and is input to the measuring microcomputer 4 as a voltage signal.

  The measurement microcomputer 4 calculates the product of each current value detected by each current transformer CT1, CT2 and each line voltage, adds both products, and outputs a smoothed value as an output value. The measurement block 2 and the display block 3 are configured to communicate with each other by serial communication, and the output of the measurement microcomputer 4 is transmitted to the display block 3 by communication.

  The measurement block 2 includes a power supply circuit 7 for obtaining a DC voltage for the measurement microcomputer 4 from the line voltage between the voltage lines L1, L2 and the neutral line N. The power supply circuit 7 is connected via a power supply line (not shown). Power is also supplied to the display block 3. The measurement block 2 is provided with a zero-cross detection unit 8 that detects a zero-cross point with respect to the line voltage, and the detection result of the zero-cross detection unit 8 is transmitted to the measurement microcomputer 4 and the display block 3.

  The display block 3 has a microcomputer as a main component, an arithmetic processing unit 9 that calculates at least an integrated electric energy based on an output value of the measuring microcomputer 4, and an electric power that can display the integrated electric energy obtained by the arithmetic processing unit 9 A quantity indicator 10. The power amount indicator 10 is formed by integrating a liquid crystal display 11 and a backlight 12, and a display control unit 13 for driving control of the liquid crystal display 11 and a driver 14 for driving the backlight 12 are included in the arithmetic processing unit 9. Connected to. Here, the arithmetic processing unit 9 obtains the integrated power amount supplied to the load during a predetermined period (here, a month unit) based on the output of the measurement microcomputer 4 and the output of the clock unit (RTC) described later (in this case, monthly units) ( That is, there is provided an integration means 21 for integrating the instantaneous power detected by the measurement block 2 to obtain the integrated electric energy.

  Furthermore, the display block 3 of the present embodiment manages an operation unit 15 for selecting display contents on the liquid crystal display 11 and various settings, an S-RAM 16 and an EEPROM 17 for storing various data, and a current date and time. And a backup battery 19 that supplies power in the event of an abnormality or a commercial power failure. The EEPROM 17 stores a past integrated power amount, a target integrated power amount (target value) that is a target of the integrated power amount in the predetermined period, and the like. Further, the display block 3 has a socket 30 for mounting a memory card (not shown) made of an SD memory card (registered trademark) used when taking out past measurement data, and a socket 30 and an arithmetic processing unit 9. An interface 31 interposed therebetween is provided. The measurement data taken out by the memory card includes, for example, a current value, a voltage value, and an electric energy managed for each time zone, and the taken measurement data can be confirmed by an external device (such as a personal computer). it can.

  Here, the arithmetic processing unit 9 ends the predetermined period based on the target setting means 22 for setting the target integrated power amount by the operation of the operation unit 15 and the current integrated power amount and the target integrated power amount. It has a function of a determination means 23 for determining whether or not the integrated power amount is expected to exceed the target integrated power amount at the time. Then, the display block 3 displays an LED (light emitting diode), which is a light emitting element that always emits light, in order to externally notify the determination result of the determination means 23 as to whether or not the integrated electric energy is expected to exceed the target integrated electric energy. The light emitting display unit 20 provided is provided separately from the power amount indicator 10.

  As shown in FIG. 2, the watt-hour meter 1 has a container body 40 that is formed in a thin box shape and can be attached to a wall surface or the like, and the measurement body 2 and the display block 3 are provided on the container body 40. . On the front side of the body 40 are a liquid crystal display 11, an execution switch SW1 for setting / selecting each setting item, an up switch SW2 for increasing the value of each setting item, and a down switch SW3 for decreasing the value of each setting item. The operation unit 15 includes a menu switch SW4 for switching the display of the liquid crystal display and an item switch SW5 for switching items. A lid 41 that can be opened and closed is provided below the liquid crystal display 11 on the front surface of the vessel 40, and terminals (not shown) for connecting the current transformers CT1 and CT2 to a portion covered with the lid 41. Terminals (not shown) for connecting the voltage lines L1, L2 and the neutral line N are provided.

  Furthermore, a plurality of (here, three) LEDs 20a to 20c constituting the light emitting display unit 20 are disposed on the front side of the container body 40. The LEDs 20a to 20c are arranged in a line on the left and upper sides of the liquid crystal display 32. The LEDs 20a, 20b, and 20c have different emission colors. In the example of FIG. 2, the rightmost LED 20a is red, the central LED 20b is yellow, and the leftmost LED 20c is green.

  Note that a card slot 42 into which a memory card is inserted is formed below the light emitting display unit 20 on the front surface of the container 40, and an LED 43 indicating that data is being written to the memory card is formed on the right side of the card slot 42. An LED 44 indicating that data is being recorded in the built-in memory (S-RAM 16, EEPROM 17) and an LED 45 indicating whether the power is on or off are provided.

  Hereinafter, operation | movement of the arithmetic processing part 9 of the watt-hour meter 1 which concerns on this embodiment is demonstrated, referring the flowchart of FIG. Here, the operation of the arithmetic processing unit 9 when the target integrated power amount is already set by the target setting means 22 will be described. The target integrated power amount setting process will be described later.

  The arithmetic processing unit 9 calculates the instantaneous power (S1), and then calculates the integrated power amount by integrating the instantaneous power (S2). The obtained integrated electric energy is stored and managed for each time zone, and the integrated electric energy for the current month is updated at a constant period (for example, one minute period) (S3). At this time, the arithmetic processing unit 9 determines whether one month has elapsed since the integration start time by the integrating unit 21 based on the output of the clock unit 18, and when the one month has elapsed, the integrated power amount by the integrating unit 21 Are reset and stored in the EEPROM 17 as past data.

  Here, the arithmetic processing unit 9 obtains a threshold value serving as a guideline up to the present time from the target integrated power amount, and compares the integrated power amount with the threshold value (S4). More specifically, the target integrated power is the ratio of the elapsed time from the starting point of the predetermined period (here, 0: 0: 0 of the first day of the month) to the present period in the predetermined period (here, 1 month). The value multiplied by the amount is set as the current determination threshold. Further, a value that is smaller than the determination threshold and has a constant ratio to the determination threshold (here, 90% of the current determination threshold) is set as the current attention threshold. In S4, the actual value of the accumulated power amount at the present time is compared with each of the determination threshold value and the attention threshold value. The comparison between the integrated power amount and the threshold value is periodically performed every time the integrated power amount is updated.

  When the actual value of the integrated power amount exceeds the determination threshold (that is, when the actual value> the determination threshold), the determination unit 23 exceeds the target integrated power amount at the end of the predetermined period. A non-alarm state in which the integrated power amount is not expected to exceed the target integrated power amount at the end of the predetermined period when it is determined that the expected alarm state is reached and the actual value of the integrated power amount does not exceed the determination threshold It is judged that it hits. In the latter case, based on the comparison result between the actual value of the accumulated electric energy and the caution threshold, if the actual value exceeds the caution threshold (that is, if caution threshold <actual value ≤ determination threshold), the predetermined period When it is determined that the accumulated power amount is likely to exceed the target accumulated power amount at the end of, and the actual value does not exceed the caution threshold (that is, the actual value ≤ caution threshold), the accumulated power It is determined that there is a margin state in which the possibility that the amount exceeds the target integrated power amount is low (S5).

  Here, the comparison result (that is, the determination result of the determination unit 23) is notified by the light emission state of the light emitting display unit 20. That is, when it is determined that there is a marginal state, the green LED 20c of the light emitting display unit 20 is turned on (S6), and when it is determined that it is a caution state, the yellow LED 20b of the light emitting display unit 20 is turned on (S7). ). When it is determined that the alarm state is reached, the red LED 20a of the light emitting display unit 20 is turned on (S8). Here, the light emitting display unit 20 always lights any one of the LEDs 20a to 20c, thereby displaying whether the actual value of the current integrated power amount corresponds to an alarm state, a caution state, or a margin state. The judgment result of the judgment means 23 described above is recorded in the EEPROM 17 (S9), and depending on the content, it is notified to other devices by contact output.

  Thus, for example, as shown in FIG. 4 (the horizontal axis is the time axis and the vertical axis is the integrated electric energy for the current month), the actual value of the integrated electric energy from the start (the beginning of the month) to the end (the end of the month) of the predetermined period. When A changes, the light emission state of the light emission display part 20 changes every moment by the comparison result with the actual value and threshold value in each time. That is, while the actual value A corresponds to the region Z above the straight line defined by the determination threshold in FIG. 4 (that is, the region exceeding the determination threshold) Z, it is determined as an alarm state and the red LED 20a is turned on. On the other hand, the region below the straight line defined by the determination threshold (that is, the region below the determination threshold) is further divided into regions X and Y by the straight line defined by the attention threshold. Here, while the actual value A corresponds to the area X below the straight line defined by the caution threshold (that is, the area below the caution threshold) X, it is determined that there is a marginal state, and the green LED 20c is lit, While the actual value A corresponds to the area Y above the straight line defined by (i.e., the area below the determination threshold and exceeding the caution threshold), the yellow LED 20b is turned on because it is determined to be in the caution state. In the example of FIG. 4, the period from the beginning of the month until the determination threshold reaches 1% of the target power amount is set as a mask period, and the light emitting display unit 20 is completely turned off without making a determination during the mask period. And

  As a result, the light-emitting display unit 20 displays a warning when the integrated power amount is expected to exceed the target integrated power amount at the end of the predetermined period (when one month has elapsed from the start of integration of the integrated power amount). In the state), the red LED 20a is turned on, and if it is expected not to exceed, the yellow or green LEDs 20b and 20c are turned on. Therefore, the user can know the determination result as to whether or not the integrated power amount is expected to exceed the target integrated power amount from the light emission state of the light emitting display unit 20. In addition, if it is expected that it will not be exceeded, it is divided into two stages: when the integrated power amount is likely to exceed the target integrated power amount at the end of the predetermined period (caution state) and when it is low (margin state) Since the notification is made, it is possible to grasp in more detail what state the actual value of the current integrated power consumption is in.

  Next, the target integrated power amount setting process will be described with reference to the flowchart of FIG.

  As an initial setting, the arithmetic processing unit 9 sets a clock for setting the current date and time (S10), sets current transformers CT1 and CT2, and sets a measurement for enabling power measurement (S11). Function setting (S12) for enabling the light emission display function (notification function) 20 is executed. Here, the setting items are switched by operating the item switch SW5, and the setting contents are selected and determined using the execution switch SW1, the up switch SW2, and the down switch SW3.

  When the initial setting is completed, the user is allowed to select a method for setting the target integrated electric energy (target value) from “automatic” in which the integrated electric energy is automatically set and “manual” in which the integrated electric energy is manually set (S13). . Here, when “manual” is selected, a setting screen for manual setting is displayed on the liquid crystal display 11, and an arbitrary integrated electric energy can be input using the execution switch SW1, the up switch SW2, and the down switch SW3. (S14). In this way, by making it possible for the user to set the target integrated power amount appropriately, the target value can be easily set and changed between a month with a large integrated power amount and a month with a small integrated power amount.

  On the other hand, when “automatic” is selected, the clock unit 18 is driven to start measurement (S15). Then, when the current time is the start point of the predetermined period (here, 0: 0: 0 of the first day of the month) (S16), the measurement data (integrated power amount etc.) for the past two months is stored in the EEPROM 17. It is determined whether it has been performed (S17). If there are measurement data for the past two months, editing processing such as conversion according to the calendar is performed on the measurement data of the previous month (S18). For example, if the current month is March 2009, the accumulated power amount for February 2009, which has only 28 days, is stored as the measurement data for the previous month. Add and process to the accumulated power for 31 days. Then, the integrated power amount processed in S18 is stored in the EEPROM 17 as the target integrated power amount for the current month (S19).

  Thereby, since the target integrated power amount is automatically set, there is an advantage that it is possible to save the user from setting the target integrated power amount. However, such automatic setting of the target integrated power amount is not performed unless there is measurement data for the past two months, and therefore can be set from the month after the month when the watt-hour meter 1 is used.

  Although not described in detail, the liquid crystal display 11 includes a current date and time, a current instantaneous power, a target integrated power amount for the current month, a current integrated power amount, a determination threshold value, a caution threshold value, and past measurement data. Etc. are displayed. At this time, if the target integrated power amount and the integrated power amount are displayed at the same time, it becomes easy to compare the target value with the actual value. Further, if the ratio of the integrated power amount to the target integrated power amount can be displayed, the user can easily determine how much the current integrated power amount has reached the target integrated power amount. Here, the display content of the liquid crystal display 11 can be switched by operating the menu switch SW4. In addition, as shown in FIG. 4, the liquid crystal display 11 may be configured to display a graph in which the integrated power amount is represented in time series together with the determination threshold value and the attention threshold value.

  The watt-hour meter 1 of the present embodiment described above is installed at a position that is easy to enter the user's field of view, and separately from the liquid crystal display 11, the light emitting display unit 20 that constantly notifies the judgment result of the judging means 23 according to the light emitting state. Therefore, the user can easily know the determination result from the light emission state of the light emitting display unit 20 without confirming the display on the liquid crystal display 11. That is, unlike the case where the user confirms information such as the integrated power amount displayed on the liquid crystal display 11, the user can know the determination result of the determination unit 23 at a glance. For this reason, for example, when it is determined that an alarm state in which the integrated power consumption is expected to exceed the target value at the end of the predetermined period, the user can recognize the excessive use of power and try to save power. It will be easier to promote In addition, if it is expected that it will not exceed, it will be notified in two stages: a caution state where the integrated power amount is likely to exceed the target integrated power amount at the end of the predetermined period, and a low margin state. The user can make a finer judgment.

  Further, by making the ratio between the attention threshold and the determination threshold (9:10 in this case) constant, the difference between the determination threshold and the attention threshold increases with the passage of time from the start of the predetermined period. Therefore, at the end of the predetermined period, it is possible to determine and notify the attention state with a margin before the actual value of the integrated power amount reaches the determination threshold as compared with the initial period of the predetermined period. That is, as the end time of the predetermined period is approached, the accumulated power amount that can be suppressed by the end of the predetermined period by the user's efforts becomes small. It is possible to be aware of power saving at the stage, and it becomes easy to keep the integrated power amount at the end of the predetermined period below the target integrated power amount.

  Here, since the light emitting display unit 20 performs notification based on the light emission colors of the LEDs 20a to 20c, the user can know the determination result even from a position relatively distant from the watt hour meter 1. For example, when the watt-hour meter 1 is installed on the wall in front of the sofa in the living room, the determination result can be notified to the user sitting on the sofa. In addition, in the present embodiment, a light emission pattern similar to that of a traffic light is used, such as green lighting in a margin state, yellow lighting in a caution state, and red lighting in an alarm state, so that the user intuitively determines the determination result. Easy to understand.

  In the present embodiment, an example in which the light emitting display unit 20 notifies the determination result based on the light emission color is shown. However, the light emitting display unit 20 may be any device that performs notification based on the light emission state. You may make it alert | report according to the position or number of LED which arrange | positions apart and arrange | positions and makes it light.

(Embodiment 2)
The watt-hour meter 1 according to the present embodiment is different from that according to the first embodiment in that a function as a mode switching unit that switches the operation mode of the power indicator 10 between the normal mode and the power saving mode is added to the arithmetic processing unit 9. It differs from the electricity meter 1.

  When the operation unit 15 is not operated for a predetermined timer time or longer while the power amount display unit 10 is operating in the normal mode in which the power amount display unit 10 displays the accumulated power amount or the like, the power amount display unit 10 (liquid crystal display) The operation mode is switched to a power saving mode in which energization to the device 11 and the backlight 12) is stopped. That is, in the power saving mode, the liquid crystal display 11 is not displayed, and the power consumption of the watt hour meter 1 can be suppressed lower than that in the normal mode, and the life of the liquid crystal display 11 and the backlight 12 can be extended. I can expect. On the other hand, when the operation unit 15 is operated while the power amount indicator 10 is operating in the power saving mode, the arithmetic processing unit 9 returns the operation mode to the normal mode.

  However, the notification of the determination result by the light emitting display unit 20 is continued even in the power saving mode. Therefore, the user can always check the determination result of the determination unit 23 regardless of the operation mode of the power amount display 10.

  In the power saving mode, the liquid crystal display 11 is not completely hidden as described above. For example, a configuration in which the power consumption is reduced by reducing the brightness of the backlight 12 may be adopted. Good.

  Other configurations and functions are the same as those of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Electric energy meter 2 Measuring block 3 Display block 9 Arithmetic processing part 10 Electric energy indicator 20 Light emission display part 20a-20c LED (light emitting element)
21 Accumulating means 22 Target setting means 23 Judging means 40 Body

Claims (5)

  Measuring means for measuring the voltage and current supplied to the load via the power line is connected, and the integrated power amount supplied to the load within a predetermined period using the instantaneous voltage value and the instantaneous current value measured by the measuring means Integrating means for determining the power, an electric power indicator for displaying the integrated electric energy obtained by the integrating means, target setting means for setting a target value of the integrated electric energy at the end of the predetermined period, current integrated electric energy and A determination means for determining, based on a target value, an alarm state in which the integrated power amount is expected to exceed the target value at the end of the predetermined period and a non-alarm state in which the integrated power amount is not expected to exceed the target value; A watt-hour meter comprising a light emitting element provided separately and having a light emitting display unit that constantly emits light and notifies a determination result of the determination means according to a light emission state.   The determination means uses a determination threshold that increases with time from the start of the predetermined period and reaches the target value at the end of the predetermined period. As a result of comparing the current integrated power amount and the determination threshold, The watt-hour meter according to claim 1, wherein the alarm state is determined when the electric energy exceeds a determination threshold.   The non-alarm state is classified into a caution state and a margin state, and the determination means uses a caution threshold that is set lower than the determination threshold and increases with the passage of time. The watt hour meter according to claim 2, wherein, as a result of comparing the caution threshold value and the caution threshold value, the watt hour meter is determined to be in a caution state when the integrated power amount does not exceed the determination threshold value but exceeds the caution threshold value.   The light emitting display section includes a plurality of light emitting elements having different light emission colors, and changes a light emitting state by switching light emitting elements to emit light according to a determination result of the determination unit. The watt-hour meter according to any one of claims 1 to 3. An operation unit that receives an operation related to display contents of the power amount display; and a mode switching unit that switches an operation mode of the power amount display according to an operation state of the operation unit, wherein the mode switching unit includes the power amount display When operating in the normal mode, if the operation of the operation unit is not detected for a predetermined timer time or longer, the operation mode is set to the power saving mode in which the power consumption is reduced by reducing the brightness of the non-display or display screen. The watt-hour meter according to claim 1, wherein the watt-hour meter is switched.

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