JP2002062320A - Power measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power measuring apparatus, by which an integrated power value and integrated current value in the section of a change in a current value and a power value can be measured at a time and with accuracy, e.g. regarding a measuring object whose current value and power value change irregularly. SOLUTION: In the power measuring apparatus, lathes instantaneous value of a measured signal is found, and various measured values which are obtained by executing various measuring and computing processing operations to the instantaneous value are found. The measuring apparatus is provided with a signal input part, to which a single or a plurality of control signals used to control the measuring and computing indication/termination timing of the measured signal are input; a measured-value buffer which comprises a storage region corresponding to the control signals and a computing and control part which starts the measuring and computing operation of the measured signal by the control signals; and by which a computed result obtained by the buffer is stored in the storage region, corresponding to the control signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to power integration of a power measuring device, and more particularly, to a power measurement capable of measuring the integrated power of an intermittently operating device over a certain period of time. It is about a vessel.

[0002]

2. Description of the Related Art FIG.
This will be described with reference to FIG.

In FIG. 1, a voltage signal to be measured Vin is
After being normalized to the input level of the A / D converter 3 by the voltage input circuit 1, it is input to the A / D converter 3.

The current signal to be measured Iin is normalized by the current input circuit 2 to the input level of the A / D converter 4 and then input to the A / D converter 4.

The outputs of the A / D converters 3 and 4 are realized by a digital signal processor or the like that performs various operations such as an effective value, an instantaneous power value, and an integrated power value of the measured voltage signal Vin and the measured current signal Iin. The output of the arithmetic unit 5 is input to the control unit 9.

The control unit 9 is a control device for controlling the entire apparatus realized by a CPU or the like, and issues a calculation instruction to the arithmetic unit 5 in accordance with a measurement instruction content instructed by a user via the operation unit 7. , Read out this operation result,
It is displayed on a display unit 6 realized by a liquid crystal display device, a printer, or the like.

The communication section 8 is a communication interface section for transferring a control signal sent from, for example, an external control computer (hereinafter, simply referred to as a personal computer) to the control section 9. For example, it is a contact signal interface unit that transfers a contact signal sent from an external device to the control unit 9. In the figure, an integration start signal ST and an integration stop signal SP, which are timing signals for power integration start / end, and an integration reset signal RT, which is a reset signal of the power integration value, are input to the integration control signal input unit 10.
Is connected.

In the power measuring device having such a configuration, the signals from the voltage input section 1 and the current input section 2 are sampled by the A / D converters 3 and 4 for a certain period, and the display is updated based on the sampled data. The effective voltage value, effective current value,
The calculation unit 5 calculates the instantaneous power value and the like.

The arithmetic unit 5 calculates and calculates an integrated current value and an integrated power value from these values, and displays them on the display unit 6. At this time, there are the following four typical methods for setting the integration section.

The first method is to start and stop by a user's key input to the operation unit 7 or a command from a personal computer or the like to the communication unit 8.

The second method is a method in which the integration time is set in advance, for example, to 2 hours. In this method, integration is started by a key input to the operation unit 7 or a command from a personal computer or the like, and integration is automatically stopped after a set time has elapsed.

The third method is to set an integration start time and an integration stop time in advance, and to automatically start and stop the integration at each time.

The fourth method is to control the integration operation by inputting the integration start signal ST and the integration stop signal SP to the input terminals of the integration control signal input section 10, respectively. At this time, as shown in FIG. 4, for example, a pulse signal having a certain width is input to each command signal terminal to control the integration operation.

Although FIG. 1 shows a configuration of a power measuring device having a pair of voltage and current input sections, the voltage and current to be measured are not limited to a single phase, but may be a plurality, such as a three-phase AC. In some cases, it has a phase. In this case, the power measuring device includes a plurality of input units for inputting the voltage and current of each phase, and the calculating unit 5 performs an integrated power calculation corresponding to the input units to measure the multi-phase power.

In the conventional power measuring device, the power integrated value is measured by such a configuration.

[0016]

However, the conventional power measuring device has a problem that the integrated power value and the integrated current value of a plurality of sections which the user wants to check cannot be measured at once with high accuracy. Was.

For example, in a copying machine, there are a warm-up operation, a copying operation, and a halt state. In the halt state, in order to keep the temperature of a certain portion in the machine constant, a heater may be arbitrarily selected depending on the temperature of the corresponding portion. ON at timing
Current value and power value fluctuate irregularly.

FIG. 5 is a diagram showing the fluctuation of the instantaneous power of the copying machine. In the same figure, operation 1 is a section in which the copier performs a warm-up operation, operation 2 is a section in which a copying operation is performed, and operation 3 is an operation in which the heater is turned on at an arbitrary timing during a pause state. It is a section.

When measuring the integrated power value and the integrated current value in each of the operations 1, 2, and 3 in the fluctuation as illustrated in FIG. In operation 1, the integration is started at time t1 and is stopped at time t2.

Thereafter, at time t3, when the integration is started again for the integration of the section of operation 2, the integrated value becomes
The integrated value in the operation 2 is displayed with the integrated value in the operation 1 remaining and added to the integrated value as an initial value.

In order to avoid this, if the integrated value is reset by the integrated reset signal before time t3, the integrated value in operation 1 is reset and disappears. For this reason, the results of each section cannot be separated and held independently.

When the end of the section of the operation 2 and the start of the section of the operation 3 are the same time, as at time t4,
The integration start signal and the integration stop signal are input at the same time, which causes a problem that the power measuring device cannot end the integration for the operation 2 or start the integration for the operation 3.

Furthermore, in the above-described first to third methods of the integration control, the user needs to know in advance the operation state time of each operation.
It cannot handle the case of performing any operation. In addition, even if we knew each time, the accuracy was not enough for the measurement accuracy, and manually controlling the integration operation was also a factor that deteriorated the measurement accuracy. .

Further, it takes time and effort to set the integration time in the power meter in advance, which is inconvenient.

The present invention has been made in order to solve such a problem, and an object of the present invention is to measure, for example, a measurement target having a current value or a power value that fluctuates irregularly in each section of the fluctuation. It is an object of the present invention to provide a power measuring device capable of accurately measuring the integrated power value and the integrated current value at a time.

[0026]

In order to achieve the above object, according to the first aspect of the present invention, an instantaneous value of a signal to be measured and various measured values obtained by subjecting the instantaneous value to various measurement arithmetic processing are provided. A signal input unit for inputting a single or a plurality of control signals for controlling measurement start / end timings of a signal to be measured, and a measurement value buffer having a storage area corresponding to the control signal. And a calculation management unit for starting measurement calculation of the signal under measurement by the control signal and storing the calculation result obtained in the measurement area in the storage area corresponding to the control signal.

According to a second aspect of the present invention, in the first aspect, the arithmetic processing includes at least a voltage effective value operation, a current effective value operation, an instantaneous power value operation, an integrated value operation, and an average power value operation. , An apparent / reactive power value calculation, or a power factor calculation.

According to a third aspect of the present invention, in the first aspect of the present invention, the control signal is a contact input signal input from an external device.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the control signal is a communication command signal input from an external device via communication means. is there.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a power measuring device according to the present invention. The difference from the conventional example in FIG.
The control unit 9 includes an integration control unit 9a and a measurement value buffer 9b having a plurality of storage areas A to E. The integration control signal input unit 10 receives integration control signals CN1, CN2, and CN3. The other configuration is the same as that of the conventional example, and thus the same reference numerals are given and the description is omitted.

The operation of the power measuring device having such a configuration will be described with reference to FIG.

FIG. 3 shows the power of an apparatus having a plurality of different power fluctuations (the fluctuations shown in operations 1 to 3 in the figure) in the power measuring device of the present invention, such as the above-described copier. It is a figure explaining operation at the time of performing measurement.

The power measuring device starts measurement at time t0, and measures and calculates a voltage effective value, a current effective value, an instantaneous power value, and the like at every preset display update cycle.

Next, at time t1, the integration control signal CN
When the signal No. 1 is in a low state and power integration is permitted (this state is referred to as enable in the following description), the power meter sequentially integrates data measured in the display update cycle at that time. Calculate the integrated power value 1,
The integrated current value 1 (the integrated power and the current value in the section of the operation 1) is obtained, and thereby, the total integrated power value and the total integrated current value (the total integrated power and the current value in all the sections). ) Is obtained and displayed on the display unit 6 together with the voltage-voltage effective value, the current effective value, the instantaneous power value, and the like for each display update cycle.
The calculated integrated power value 1 and integrated current value 1 are stored in the storage area A of the measured value buffer 9b, and the total integrated power value and the total integrated current value are stored in the storage areas D and E.

At time t2, the signal of the integration control signal CN1 becomes High, and power integration is prohibited (this state is referred to as disabled in the following description).
At this point, the integration calculation for the integrated power value 1, the integrated current value 1, the total integrated power value, and the total integrated current value ends. At this time, the storage areas A, D, and E of the measurement value buffer 9b
Is held as it is and displayed on the display unit 6.

At time t3, when the signal of the integration control signal CN2 is enabled, the integrated power value 2 and the integrated current value 2 (operation 2) different from the integrated power value 1 and the integrated current value 1 described above.
Are the integrated power and current values in the section of. ) Start the calculation. As a result, the total integrated power value and the total integrated current value are
It is calculated again. The integrated power value 2 and the integrated current value 2 calculated here are stored in the storage area B of the measured value buffer 9b, and the total integrated power value and the total integrated current value are added to the values of the storage areas D and E. Is stored.

At time t4, the integration control signal CN2
When the signal is disabled, the integration calculation for the integrated power value 2 and the integrated current value 2 is completed at this time. At this time, the values of the storage areas B, D, and E of the measurement value buffer 9b are held as they are and displayed on the display unit 6.

At time t4, since the integration control signal CN3 is simultaneously enabled, the integrated power value 3 and the integrated current value 3 (operation 3) different from the integrated power value 2 and the integrated current value 2 are used. ) Is calculated. The calculated integrated power value 3 and integrated current value 3 are stored in the storage area C of the measured value buffer 9b.

Regarding the total integrated power value and the total integrated current value, at time t4, the integration control signal CN2 is disabled, but since the integration control signal CN3 is enabled, the calculation is continued and the measurement is continued. The value is added to the values of the storage areas D and E of the value buffer 9b and stored.

Then, at the time t5, the integration calculation for the operation state 3 ends. At this time, the measured value buffer 9b
Of the storage areas C, D, and E are held as they are and displayed on the display unit 6.

Thus, finally, the integrated power values 1, 2,.
3, and the integrated current values 1, 2, 3, the total integrated power value, and the total integrated current value can be measured simultaneously in one measurement operation.
In addition, the user can arbitrarily read out the measured value stored in the measured value buffer 9b and display it on the display unit 6.

The logic of the integration control signal CN related to the operation state of the object to be measured may be conversely high, enabled high, and disabled low. In that case, the setting of the integration operation in the control unit 9 may be changed accordingly. Further, the integration and integration control signal CN
Is three, but the number is not limited to three, and may be more or less. In that case, the storage area of the measurement value buffer 9b is prepared according to the number.

Further, in this embodiment, the division of the section of the integration operation has been described as the display update cycle.
It is also possible to perform an integration operation with this division as the sampling period of the A / D converter, in which case,
Since the time resolution is improved, a more accurate integration result can be obtained.

Therefore, in the example of the copying machine, the warming-up signal is the integration control signal CN1, the signal indicating that copying is in progress is the integration control signal CN2, and the signal indicating that the heater is operating is the integration control signal CN3. By inputting to the input unit 10, it is possible to accurately measure the power, the integrated power value, and the like during warm-up, copying, and heater operation for each state.

That is, in the power measuring device of the present invention, one or a plurality of integration control signals and a measurement value buffer corresponding to the control signals on a one-to-one basis are provided. By storing the measured value obtained by the integration control signal in a measurement value buffer corresponding to each control signal, for example, by using a signal indicating the operation state of the measurement target as the integration control signal, Since each section of the fluctuation can be automatically determined according to the change in the operation state of the measurement target, the integrated power value and the integrated current value of each section can be easily and accurately measured.

It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of illustration and illustration of the invention. Therefore, the present invention is not limited to the above-described embodiment, and includes many more modifications without departing from the spirit thereof.
This includes deformation.

For example, the integration control signal is not limited to the configuration in which the contact input signal is connected to the integration control input signal section, but may be configured to be input as a communication command via the communication section 8.

Further, a measurement value other than the integration value, such as a voltage effective value and a reactive power value, may be stored in the measurement value buffer by turning on and off the integration control signal.

[0049]

As described above, according to the present invention, the following effects can be obtained. In the invention according to claims 1 to 4, as described above, one or a plurality of integration control signals for controlling the start and stop of power integration, and a measurement value buffer corresponding to this one-to-one, For example, if a signal indicating the operation state of the measurement target is used as the integration control signal, each section of the variation can be automatically determined according to the change in the operation state of the measurement target. Can be easily and accurately measured.

Further, by inputting a plurality of integration control signals and setting integration items by the number, integration measurement of a plurality of sections can be performed by one measurement operation. Further, based on the integration results of the respective sections, a comprehensive integrated value for the section desired by the user can be easily obtained.

Further, since the function of the above-described integration control section can be realized only by modifying the firmware, it is possible to realize the function at low cost without adding a new circuit to the conventional digital power meter.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a power measuring device according to the present invention.

FIG. 2 is a diagram for explaining the operation of the power measuring device of the present invention.

FIG. 3 is a configuration diagram illustrating an example of a conventional power measuring device.

FIG. 4 is a diagram illustrating the operation of a conventional power measuring device.

FIG. 5 is a diagram illustrating the operation of a conventional power measuring device.

[Explanation of symbols]

 Vin voltage signal to be measured Iin current signal to be measured 1 voltage input circuit 2 current input circuit 3, 4 A / D converter 5 arithmetic unit 6 display unit 7 operation unit 8 communication unit 9 control unit 9a integration control unit 9b measurement value buffer 10 Integration control signal input section

Claims (4)

[Claims] A power measuring device for obtaining an instantaneous value of a signal to be measured and various measurement values obtained by performing various measurement and calculation processes on the instantaneous value, comprising: Or a signal input unit for inputting a plurality of control signals, a measurement value buffer having a storage area corresponding to the control signal, and starting a measurement calculation of the signal under measurement by the control signal;
A power measuring device comprising: a calculation management unit that stores a calculation result obtained in the storage area corresponding to the control signal. 2. The arithmetic processing includes at least one of a voltage effective value operation, a current effective value operation, an instantaneous power value operation, an integrated value operation, an average power value operation, an apparent / reactive power value operation, and a power factor operation. The power measuring device according to claim 1, wherein: 3. The power meter according to claim 1, wherein the control signal is a contact input signal input from an external device. 4. The power measuring device according to claim 1, wherein the control signal is a communication command signal input from an external device via communication means.