JP3330519B2 - Electronic watt-hour meter and its error adjustment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an error adjustment for adjusting the measurement of an electronic watt-hour meter within an allowable error, and more particularly to an electronic watt-hour meter capable of automating the error adjustment and a method of adjusting the error. It is about.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram showing an error adjustment of a conventional electronic watt-hour meter disclosed in Japanese Unexamined Patent Application Publication No. H11-157, and this adjustment is performed by a master meter method based on relative comparison.

In FIG. 1, reference numeral 1 denotes an imaginary load test power supply comprising a power supply device capable of freely changing and outputting voltages, currents and phases.
Is a master meter which is a reference meter, and 3 is a watt-hour meter to be adjusted. Reference numeral 31 denotes a current transformer (C) that converts a value proportional to the input current to a level that can be processed by an electronic circuit in the watt hour meter 3.
T) and 32 are transformers (VT) for converting to a value proportional to the input voltage, and 33 is a W / F converter for multiplying the input current and the input voltage to convert the frequency to a frequency proportional to the power.

A correction value calculator 34 compares a frequency proportional to the power from the master meter 2 with the output of the W / F converter 33 and calculates a correction value from the difference, and 35 stores the calculated correction value. This is a correction value storage unit composed of a nonvolatile memory. 36 is a correction unit for correcting the output of the W / F converter 33 with a correction value, 37 is a frequency division unit for dividing the frequency proportional to the corrected power, and 38 is counting the frequency proportional to the divided power. Counter 39, counter 38
Is a display unit that displays the value of the power amount as an electric energy.

Next, the operation of the conventional error adjustment will be described. The same test power is supplied to each of the imaginary load test power supply 1 from the imaginary load test power supply 1 by connecting the master meter 2 and the regulated watt-hour meter 3 in voltage and current in series. Master meter 2
The correction value is calculated so that the difference between the output of the W / F converter 33 and the correction value is eliminated, and is stored in the correction value storage unit 35. The subsequent measurement of the electric energy is performed while correcting the output of the W / F converter 33 by the stored correction value.

[0006] The error adjustment of the electronic watt-hour meter is automatically adjusted.
Adjustment is performed only at one point with a power factor of 100%, and in the case of multiple elements, adjustment is performed with balance adjustment. In such a watt-hour meter, an error occurs at a light load and a low power factor due to the effects of the excitation currents of CT31 and VT32 and watt loss.
As shown in (1), in order to obtain a highly accurate watt-hour meter, it is necessary to perform error correction adjustment at each point of rated load, light load, and power factor characteristics.

FIG. 23 is a circuit block diagram of another conventional electronic watt-hour meter disclosed in, for example, Japanese Patent Application Laid-Open No. 6-258362, which shows a multi-element (three-element) digital electronic device using sigma-delta modulation. It is a watt-hour meter. In the figure,
1, 31, 32, 38 and 39 are the same as those described above. 4 is a digital electronic watt-hour meter, 40 is a CPU4
1 is a calculation control unit of the digital electronic watt-hour meter 4 including

Reference numeral 42 denotes a sigma-delta modulation circuit 421, a digital low-pass filter 422, and a current register 4 for each phase.
23, 424, and 425. 43 is a sigma-delta modulation circuit 431, a shift register 432 for power factor adjustment, and a digital low-pass filter 4
33, a voltage A / D conversion circuit including voltage registers 434, 435, and 436 for each phase.

Reference numeral 44 denotes a multiplier which multiplies the current value and voltage value of each phase to obtain a power value, 45 denotes an adder for summing the power values of each phase, 46 denotes a digital low-pass filter, and 47 denotes a light load adjustment adder. It is. 48 is an accumulator, 49 is a register, and 50 is a magnitude comparator, which outputs a counting pulse to the counter 38 every time the total value of the power exceeds a predetermined reference value. 51 is a balance adjusting multiplier.

In order to improve the weighing accuracy, power factor adjustment registers 61 to 63 for setting respective adjustment values in consideration of rated load, light load and power factor characteristics, light load adjustment register 64,
A rating reference value register 65 and inter-element balance adjustment registers 66 and 67 are provided, respectively.

Next, the operation of measuring the electronic power amount will be described. The sigma-delta modulation circuits 421 and 431 perform A / D conversion on the voltage and current input at the sampling frequency fs from the arithmetic control unit 40. At this time, switch SW
Are switched in synchronization with each other to change the digital value voltage for each phase,
The current is obtained, the power value is converted into a digital value by the multiplier 44, and the power value of each phase is added by the adder 45.

The power value obtained by adding the phases is a magnitude comparator 50, which outputs a count pulse to the arithmetic control unit 40 and the counter 38 every time the total power value exceeds a predetermined reference value. This counting pulse is sent to the display 3 via the counter 38.
A total power value is displayed at 9.

Next, a description will be given of an adjustment operation procedure for making the measurement accuracy of the electronic power amount within the allowable error range. The adjustment procedure is as follows: the rated load adjustment of the rough adjustment (provisional F-value setting) The element-to-element balance adjustment (B2 value, B
3 values), rated load adjustment (F value setting), light load adjustment (L value setting), and power factor adjustment (P1, P2 value, P3 value setting).

(1) First, an imaginary load test power source may be initially rough, but as a rated load adjustment (tentative F value setting), a rated current, a rated voltage and a power factor of 100% are simultaneously input to all the elements. 1 is switched to apply the electric energy for a predetermined time.
Since the rated pulse constant is determined as a specified value by the phase wire system, rated voltage, rated current, etc., several trials are performed while changing the F value to obtain the rated pulse constant, and the provisional F value is determined. It is set and stored in the rated reference value register 65.

(2) To adjust the balance between the elements, the imaginary load test power supply 1 is set to a rated current, a rated voltage, and a power factor of 100%, a given amount of electric power is applied to a representative element, and a counting pulse W01 during this time. Is stored. Then, the imaginary load test power supply 1 is switched so that the rated current, the rated voltage, and the power factor of 100% are input to another element, and the electric energy for a predetermined time is applied.

Knowing the power amount counting pulse W02 of the next element, the balance adjustment value B2 is obtained by B2 = W02 / W01 and stored in the balance adjustment register 66. By multiplying the output of another element by the balance adjustment value B2 in the balance adjustment multiplier 51, balance adjustment is performed to eliminate variations among elements so as to obtain the same number of count pulses with the same power amount. Further, the balance adjustment value B3 of another different element
Since the setting is made in the same manner, the description is omitted.

(3) In the rated load adjustment (F value setting), the imaginary load test power supply 1 is switched so that the rated current, the rated voltage and the power factor of 100% are simultaneously inputted to all the elements, and the electric energy for a predetermined time is reduced Give. Since the rated pulse constant is determined by the phase-wire system, rated voltage, rated current, etc., several trials are performed while changing the F value to obtain the rated pulse constant, and the F value is set and the rated reference value is set. It is stored in the register 65.

(4) In the next light load adjustment (L value setting), for example, the current is reduced to 1/10 of the rated current, the rated voltage and the power factor are set to 1.0.
The imaginary load test power supply 1 is switched and set to 0, and the electric energy for a predetermined time is given. And 1/10 of the rated pulse constant
The L value is set and stored in the light load adjustment register 64 by performing several trials so as to obtain the number of pulses.

(5) Power factor adjustment (setting of P1, P2, and P3 values) is performed for each element. The imaginary load test power supply 1 is switched so that a rated current, a rated voltage, and a power factor of 0.50 are input to one element, and an electric energy for a predetermined time is applied.
The number of shift stages is set in the power factor adjustment register 61 so that the number of pulses at this time is の of the number of pulses at the rated current, rated voltage, and power factor of 1.00 per element. The other power factor adjustment registers 62 and 63 are set similarly.

[0020]

In the error adjustment of the electronic watt-hour meter as described above, the voltage, current,
Each time the power factor is changed, the imaginary load test power supply 1 is manually switched and set, the adjusted power is applied, and the number of output pulses at that time is compared with a reference number (specified value) to grasp the error amount. It was necessary to set and input an error adjustment value to each adjustment register.

The present invention has been made to solve such a problem, and does not require a human sense for adjustment, and the adjustment itself can be automated simply by pressing a start switch for adjustment. An object of the present invention is to obtain an electronic watt-hour meter and a method for adjusting an error thereof.

[0022]

(1) An electronic watt-hour meter according to claim 1 of the present invention comprises: a digital multiplier for converting an input voltage / current into a power pulse number proportional to a power amount; Error adjustment such as balance adjustment and power factor adjustment to adjust the error when converting the power pulse number of this digital multiplier
Using an adjustment register that holds an adjustment value of each adjustment point according to an item, a memory device that stores an error adjustment program and each specified value, and the error adjustment program,
Switch sequentially to each adjustment point according to the above error adjustment items
The output of the power type corresponding to the switched adjustment point
Instruction means for instructing the test power supply to the test power supply;
The number of power pulses in a predetermined period of time obtained by inputting the output from the test power supply corresponding to the output instruction of the power supply type to the digital multiplier using the adjustment program and the memory device corresponding to the instruction An adjustment value setting means for comparing the specified value with the specified value, deriving an adjustment value for adjusting the comparison result within a predetermined error range, and writing the adjustment value in the adjustment register.

(2) An error adjusting method for an electronic watt-hour meter according to a second aspect of the present invention includes the electronic watt-hour meter according to the first aspect and a power supply type switching means for switching and outputting a predetermined power supply type. The test power supply device is connected to the power supply type corresponding to the instruction from the instruction means of the electronic wattmeter, and the output is switched. The adjustment value is derived and set by the adjustment value setting means after conversion into the number of pulses.

(3) An error adjusting method for an electronic wattmeter according to a third aspect of the present invention is the method for adjusting an error of an electronic wattmeter according to the second aspect, wherein a plurality of electronic wattmeters are tested. A power supply unit connected to a power supply unit, the test power supply unit switches to a predetermined power supply type and outputs the power supply type; a supply destination switching unit for switching the output to supply the electronic watt-hour meter one by one; The control means determines the type of power supply to be switched to any one of the electronic watt-hour meters in response to an instruction from the instruction means of the electronic watt-hour meter using Then, combining the switching of the power supply type and the switching of the supply destination,
All of the adjustment points of the plurality of electronic watt-hour meters are adjusted.

[0025] (4) error adjustment method for an electronic watt-hour meter according to a fourth aspect of the present invention, electronic watt error adjusted
Type and power type switching for switching to a specified power type
Connecting a test power supply device having means and an arithmetic device,
The above watt-hour meter measures the input voltage and current in proportion to the amount of power.
Digital multiplier that converts the number of
To adjust the error when converting the power pulse number of the
According to error adjustment items such as balance adjustment and power factor adjustment
Adjustment register that holds the adjustment value of each adjustment point
And the power pulse number can be transmitted to the arithmetic device.
Transmitting means, and adjusting values inputted from the arithmetic unit
An adjustment value setting means for writing to the adjustment register.
In addition to using a sub watt-hour meter,
The error adjustment program of the watt-hour meter and each specified value are stored.
Memory device and the above error adjustment program
Switch to each adjustment point according to the above error adjustment item.
Of the power supply type corresponding to the
Means for instructing the test power supply to output power;
Using the difference adjustment program, output from the test power supply
With the predetermined time obtained by inputting the force to the digital multiplier,
Of the memory device corresponding to the number of power pulses of the
The specified value is compared with the specified value, and the comparison result is within the specified error range.
Adjustment value deriving means for deriving an adjustment value to be adjusted to fit;
The test power supply unit uses the arithmetic unit having
Switch to the power type corresponding to the instruction from the instruction means of the arithmetic unit.
The electronic watt-hour meter receiving this output
It is converted to the number of power pulses and output to the arithmetic unit.
In response to the number of force pulses, the adjustment value deriving means of the arithmetic unit adjusts the value.
Derive an adjustment value, and derive this adjustment value from the electronic power
Set and write to the adjustment register by the adjustment value setting means of the meter.
That's what I did.

(5) An electronic watt-hour error adjusting method according to a fifth aspect of the present invention is the electronic watt-hour meter according to the fourth aspect.
And a power type switching means for switching to a predetermined power type and outputting.
A test power supply having a step, an arithmetic unit, and a reference instrument;
And the watt-hour meter converts the input voltage and current
Digital multiplier that converts the number of power pulses proportional to the amount
And the error when converting the number of power pulses of this digital multiplier
Error adjustment such as balance adjustment and power factor adjustment for adjustment
Adjustment that maintains the adjustment value of each adjustment point according to the item
Register and the number of power pulses can be sent to the arithmetic unit
Transmission means, and adjustment input from the arithmetic unit
Adjustment value setting means for writing a value to the adjustment register.
In addition to using the electronic watt-hour meter provided,
It has the same digital multiplier as the electronic watt-hour meter,
The number of power pulses obtained for a constant input is the reference value.
Using a calibrated reference instrument, and the arithmetic unit is:
Error adjustment program for electronic watt-hour meter and each regulation
A memory device in which values are stored, and the error adjustment program
To each adjustment point according to the above error adjustment item.
Power supply corresponding to the sequentially adjusted switching points
Instruction means for instructing the type of output to the test power supply;
Using the above error adjustment program,
These outputs are input to the digital multiplier of the electronic wattmeter
The number of power pulses in a given time
Input from the source device to the digital multiplier of the reference instrument.
Compare the number of power pulses at a given time obtained by pressing
Adjust so that the comparison result falls within a predetermined error range
Arithmetic device having adjustment value deriving means for deriving an adjustment value
And the test power supply is the instruction means of the arithmetic unit.
Switch to the power supply type corresponding to these instructions and output
The electronic wattmeter and the reference device that received the output
Each is converted to the number of power pulses and output.
The number of the above-mentioned power pulses is compared and the comparison result is
The corresponding adjustment value is derived and output by the adjustment value derivation means, and is output.
Set the adjustment value output from the above electronic watt-hour meter to the adjustment value.
By means of writing to the adjustment register
It is.

(6) The electronic electronic device according to claim 6 of the present invention.
The method for adjusting the error of the dynamometer is described in claim 4 or claim 5.
In the error adjustment method of the sub watt-hour meter, the test power supply
Use test power supply with built-in arithmetic unit
Things.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of an error adjusting system for an electronic watt-hour meter according to Embodiment 1 of the present invention. In the figure, 1, 3
Reference numerals 1, 32, 38 to 51, and 61 to 67 are the same as those in the description of the conventional apparatus.

Reference numeral 10 denotes a test power supply, which is an imaginary load test power supply 1, a power supply switching device 11, a control CPU 12, a communication interface 13, a storage device (ROM) 14, and a timer 1.
5 is comprised. The power supply switching device 11 is a control CPU
12, the voltage and current of the imaginary load test power supply 1
The test power is output by selecting the phase and output phase. Reference numeral 16 denotes a communication line that connects the control CPU 12 of the test power supply device 10 and a CPU 41 of an electronic watt-hour meter 20 described later via the communication interface 13 and the communication interface 21.

Reference numeral 20 denotes an electronic watt-hour meter. The power meter for measuring the amount of power is the same as the conventional device shown in FIG. Reference numeral 21 denotes a communication interface, 22 denotes a nonvolatile storage device (EPROM) in which an adjustment program for adjusting the electronic watt-hour meter 20 and each set adjustment value are stored, and 23 denotes an adjustment start switch.

The power metering unit includes three current transformers 31 and 3
A plurality of transformers 32 are provided, and three sets of calculation elements of R phase, S phase, and T phase for calculating power from each current and voltage are formed. It is possible to measure the electric energy of any of the single-phase two-wire, single-phase three-wire, three-phase three-wire, and three-phase four-wire power distribution systems depending on the number of used three sets of arithmetic elements and the combination of connections.

An adjustment operation procedure for keeping the measurement accuracy of the electronic power amount within the allowable error range is performed as follows in the same manner as in the conventional apparatus. (1) Rated load adjustment for coarse adjustment (provisional F-value setting) (2) Element-to-element balance adjustment with multi-element power (B2
Value, B3 value setting), (3) Rated load adjustment (F value setting), (4) Light load adjustment (L value setting), (5) Power factor adjustment (P1, P2 value, P3 value setting) Done in

FIGS. 2 to 4 are flowcharts showing the operation procedure of the automatic adjustment according to the first embodiment of the present invention. The automatic adjustment of the electronic watt-hour meter 20 will be described with reference to this flowchart. The output of the test power supply 10 is connected to the terminal of the electronic watt-hour meter 20 by a dedicated connector (not shown), and the communication interfaces 13 and 21 are connected by the communication line 16 at the same time. In this state, the adjustment start switch 23
Is pressed, the CPU 41 receives a press signal from the adjustment start switch 23, and the CPU 41 starts the adjustment from the point of executing the adjustment program stored in the EPROM 22. Hereinafter, description will be given along a flowchart.

(1) First, each adjustment initial value stored in advance in the EPROM 22 is stored in the power factor adjustment registers 61 to 6.
3, light load adjustment register 64, rated reference value register 6
5. Read into the element balance adjustment registers 66 and 67. Further, a rated constant pulse value WK and a power factor constant pulse value WKP determined by the rated current, the rated voltage, and the phase wire method of the watt-hour meter to be adjusted are selectively inputted (step 20).
1). Each adjustment register is input with a code suitable for digital processing.

(2) First, the rated load adjustment of the rough adjustment is performed. The CPU 41 supplies the R, S, and T phases to the test power supply 10.
The phase is instructed to supply a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 1.00 (step 202). (3) Control C
The PU 12 supplies power having a rated current, a rated voltage, and a power factor of 1.00 to all phases for a certain period of time, for example, 10 seconds by the tap switching of the power supply switching device 11, and returns an energization end signal (steps 101 and 102).

(4) The electronic watt-hour meter 20 reads the number of power pulses W0 counted during this time (step 20).
3). (5) Then, a comparison is made with the rated constant pulse value WK read in advance in step 201 to obtain D = W0 / WK, and it is determined whether D is within a predetermined range (permissible error range) centered at 1.0. A judgment is made (step 204). Since the allowable error in this case is a coarse adjustment, its value is set large.

(6) When D is out of the predetermined range, the value (F) of the rated reference value register 65 is increased in the direction where D = 1.0.
The PU 41 makes a transition setting (step 205). (7) Step 101 until the value of D falls within the predetermined range;
102, 202 to 205 are repeated, and when the value of D falls within a predetermined range, the process proceeds to balance adjustment between elements.

(8) To execute the balance adjustment between the elements, the CPU 41 transmits the test power supply 10 through the communication line 16.
Only the R-phase is instructed to supply a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 1.00 (step 206). (9) Control C instructed to supply imaginary load power to R phase
PU 12 is a power supply switching device 1 stored in ROM 14
By switching one tap, for example, imaginary load power having a rated current of 30 A, a rated voltage of 200 V, and a power factor of 1.00 is supplied to the R phase (step 103).

(10) If power is supplied for a certain period of time, for example, 10 seconds by the timer 14, the control CPU 12
Returns an energization end signal to the electronic watt-hour meter 20 through the communication line 16 (step 104). (11) The electronic watt-hour meter 20 temporarily stores the number of power pulses WR counted during power supply (step 2).
07).

(12) Next, the CPU 41 instructs the test power supply 10 to supply only the S phase with a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 1.00 (step 208). (13) The control CPU 12 switches the tap of the power supply switching device 11 to a rated current of 30 A, a rated voltage of 200 V, and a power factor of 1.
00 power is supplied to the S phase for a certain time, for example, 10 seconds,
An energization end signal is returned (steps 105 and 106).

(14) The electronic watt-hour meter 20 reads the number of power pulses WS counted during this time, and compares the number of power pulses WR of the R phase temporarily stored above with D.
= WS / WR, and it is determined whether D is within a predetermined range (permissible error range) centered at 1.0 (step 20).
9, 210).

(15) If D is outside the predetermined range, the CPU 41 shifts and sets the value (B2) of the balance adjustment register 66 in the direction where D = 1.0 (step 211). Here, D = (WR-WS) / WR may be obtained to determine whether D is within a predetermined range centered on zero. (16) Step 10 until the value of D falls within the predetermined range
5, 106, and 208 to 211 are repeated, and when the value of D falls within a predetermined range, the process proceeds to T-phase balance adjustment.

(17) The CPU 41 instructs the test power supply device 10 to supply the rated current, the rated voltage, and the imaginary load power equivalent to the power factor of 1.00 to only the T phase (step 212). (18) Thereafter, D = WT / WR is set within a predetermined range by the same procedure as described above, balance adjustment is completed, and the process proceeds to rated load adjustment (steps 107, 108, 212 to 215).

(19) In the rated load adjustment, the CPU 41 instructs the test power supply device 10 to supply the R-phase, S-phase, and T-phases with the imaginary load power equivalent to the rated current, the rated voltage, and the power factor of 1.00 (step). 216). (20) The control CPU 12 supplies the power of the rated current, the rated voltage, and the power factor of 1.00 to all the phases for a certain period of time, for example, 10 seconds by the tap switching of the power supply switching device 11, and returns an energization end signal (step 109, 110).

(21) The electronic watt-hour meter 20 reads the number of power pulses W0 counted during this time (step 2).
17). (22) Then, a comparison is made with the rated constant pulse value WK read in advance in step 201, and D = W0 / WK
Is determined, and it is determined whether D is within a predetermined range (permissible error range) centered at 1.0 (step 218).

(23) When D is out of the predetermined range, the CPU 41 shifts the value (F) of the rated reference value register 65 in a direction where D = 1.0 (step 219). (24) Step 10 until the value of D falls within the predetermined range.
9, 110, 216 to 219 are repeated, and when the value of D falls within a predetermined range, the process proceeds to power factor adjustment.

(25) In the power factor adjustment, the CPU 41 instructs only the R-phase to supply the rated current, the rated voltage, and the imaginary load power equivalent to the power factor of 0.50 to the test power supply device 10 through the communication line 16 (step 220). ). (26) The control CPU 12 changes the power of the rated current, the rated voltage and the power of 0.50 to R
The phase is energized for a predetermined time, for example, 10 seconds, and an energization end signal is returned (steps 111 and 112).

(27) The electronic watt-hour meter 20 reads the number of power pulses WPR counted during this time (step 2).
21). (28) Then, in step 201, a comparison is made with the power factor constant pulse numerical value WPK read in advance. D = WPR / WPK
Is determined, and it is determined whether D is within an allowable error range centered at 1.0 (step 218).

(29) If D is outside the allowable error range, the CPU 41 shifts the power factor adjustment register 61 (P1) in the direction where D = 1.0 (step 223). (30) Step 1 until the value of D falls within the allowable error range
11, 112, 220 to 223 are repeated, and when the value of D falls within the allowable error range, the process proceeds to S-phase power factor adjustment. (31) Hereinafter, the power factor adjustment of the S phase and the T phase is performed by the same processing, and the process proceeds to the light load adjustment (113, 114, 224 ~).
227, 115, 116, 228-231).

(32) In the light load adjustment, the CPU 41 supplies the test power supply 10 to the R, S, and T phases via the communication line 16 with the imaginary load power equivalent to the rated 10% current, the rated voltage, and the power factor of 1.00. (Step 232). (33) The control CPU 12 switches the power supply switching device 11 to supply a power of 10% of the rated current, the rated voltage and the power factor of 1.00 to all the phases for a predetermined time, for example, 10 seconds, and returns an energization end signal (step). 117, 118).

(34) The electronic watt-hour meter 20 reads the number of power pulses WL counted during this period (step 2).
33). (35) Then, a comparison is made with the previously read rating constant pulse numerical value WK to obtain D = 10 * WL / WK, and it is determined whether or not D is within an allowable error range centered at 1.0 (step). 234).

(36) If D is out of the predetermined range, the CPU 41 shifts the value (L) of the light load adjustment register 64 in the direction where D = 1.0 (step 235). (37) Step 11 until the value of D falls within the predetermined range
7, 118, 216 to 235 are repeated, and when the value of D falls within the allowable error range, completion of error adjustment is notified, and completion of error adjustment is displayed (236, 119).

In the first embodiment, the power supply time is uniformly set to 10 seconds. However, this is based on the accuracy of the watt hour meter. In the case of 1000 pulses and the accuracy of 0.01%, it suffices that the time is such that 10,000 pulses can be obtained. Therefore, by setting the energizing time appropriately for each load adjustment, power factor adjustment, and light load adjustment, the rated constant pulse number WK, the power factor constant pulse number WPK, and the light load constant pulse number corresponding to the energizing time can be selected. I just need.

Further, the electronic watt-hour meter 20 calculates the number of pulses per time (counting rate) at which a predetermined accuracy can be obtained from the number of pulses and the measuring time thereof, and stops the power supply when the predetermined accuracy is reached. You may do so. In the above description, the light load adjustment has been described with the rated 10% current, but may be performed with the 5% current.

Embodiment 2 In this embodiment, the electronic watt-hour meter individually transmits its own adjustment program and commands to the test power supply 10 by EPRO.
M22 is held, but by adjusting a plurality of watt-hour meters having the same holding program in the EPROM 22, mass productivity is improved.

FIG. 5 is a block diagram of an error adjusting system for an electronic watt-hour meter according to a second embodiment of the present invention. In the figure, an electronic watt-hour meter 20 is the same as that in FIG. 1, and a plurality of electronic watt-hour meters are connected to a test power supply device 10 via a connection switch 101. Reference numeral 17 of the test power supply 10 is a supply destination switching unit controlled by the control CPU, and sends out a switching instruction to perform sequence control of the connection switch 101.

This sequence control is performed by the connection switch 10
The voltage sides R, S, and T of 1 are always turned on during adjustment, supply operating power to the electronic watt-hour meter 20, and turned off when the adjustment is completed. The current side R of the connection switch 101,
For S and T, only the electronic watt-hour meter to be adjusted is connected.

FIG. 6 is a flowchart of the adjustment procedure, which is a flow for adjusting a plurality of electronic watt-hour meters one by one.
7 and 8 are flowcharts of another adjustment procedure.
The same adjustment item of a plurality of electronic watt-hour meters is executed by all electronic watt-hour meters, and when one adjustment item is completed, the adjustment of the next adjustment item is executed for all the electronic watt-hour meters. This is the flow to be performed.

First, a description will be given with reference to the flowchart of FIG. (1) The first electronic watt-hour meter 2 out of the n electronic watt-hour meters 20 in response to a connection command from the supply destination switching means 17
0 and read the initial values (161, 26)
1, 262).

(2) Next, step 101 in FIGS.
To step 119, steps 202 to 23
The process is executed until 4 becomes “Y” (162, 263). This is to execute all adjustments for one. (3) When the adjustment of the first electronic watt-hour meter 20 is completed, an adjustment completion signal is transmitted, and the test power supply device 10 receives this signal (264, 163).

(4) Since the adjustment is the first adjustment, the process returns to the first step 161 (164). (5) Steps 161 to 164 and steps 261 to 264 are repeatedly executed until the adjustment of the n-th electronic watt-hour meter 20 is completed in this way, and all the adjustment operations are completed.

As described above, when the adjustment of the electronic watt-hour meter is completed one by one, continuous adjustment is performed one by one, and there is an advantage that the adjustment condition is stably performed. .

Next, the adjustment procedure in the flowcharts of FIGS. 7 and 8 will be described. (1) The first electronic watt-hour meter 2 out of the n electronic watt-hour meters 20 in response to a connection command from the supply destination switching means 17
0 and read the initial value (171, 27)
1, 272).

(2) Next, steps 101 to 10 in FIG.
2. Execute "rated load adjustment for coarse adjustment (setting of provisional F value)" in steps 202 to 205. (3) Switching of the connection switch 101 and the above (1)
(2) is repeated, and all of the n “rated load adjustments for initial value reading and coarse adjustment” are executed (step 17).
1-173, 271-273). In this case, after the “initial value reading” of steps 171, 271, and 272 is performed on all the electronic watt-hour meters, steps 172 and 273 are performed.
"Rated load adjustment for coarse adjustment" may be performed for all electronic watt-hour meters.

(4) Next, steps 174 to 176 and steps 274 to 275 are executed. In this step, the balance between the elements is adjusted, and the number of power pulses WR of the R phase is counted. (5) In the same manner as described above, the test power supply device 10 executes steps 105 to 118 in FIGS. 2 to 4 while repeatedly transmitting the connection command from the supply destination switching unit 17 to i = 1 to n. The formula watt-hour meter 20 executes steps 208 to 234 in FIGS. 2 to 5 until “Y” is reached while repeating the connection from i = 1 to n by the connection switch 101.

(6) Since the electronic watt-hour meters 20 sequentially transmit the first to n-th adjustment completion signals when the adjustment is completed, the test power supply 10 receives this signal, and
When the completion of the adjustment is received, an adjustment completion display is performed (steps 276, 177 to 179).

In the above adjustment procedure, all the adjustment steps are completed for each electronic watt-hour meter. However, a plurality of electronic watt-hour meters connected to the test power supply are completed for each adjustment step. You may. The embodiment will be described with reference to the flowcharts of FIGS. In the adjustment procedure of this flowchart, the adjustment of a plurality of units is performed for each step, so that the adjustment can be performed in a shorter time than the adjustment of each unit as in the flow of FIG.

As described above, in the second embodiment, a plurality of electronic watt-hour meters having the same specifications can be simultaneously adjusted.

Embodiment 3 In the configuration of the first embodiment, the electronic watt-hour meter individually stores its own adjustment program and instructions to the test power supply 10 in the EPROM 22.
For one electronic watt-hour meter, only one electronic watt-hour meter can be adjusted at the same time, and lacks mass productivity. When the adjustment program and the initial set value are changed, the EPROM 2
2 had to be replaced or rewritten to the electronic wattmeter, which was uneconomical. The third embodiment improves this point.

FIG. 9 is a connection diagram for automatic adjustment of an electronic watt-hour meter according to Embodiment 3 of the present invention. In the figure,
1, 10 to 16, 31, 32, 38 to 41, 61 to 67
Is the same as described in the first embodiment. Reference numeral 69 denotes a power operation circuit including the current A / D conversion circuit 42, the voltage A / D conversion circuit 43, the multiplier 44, the adder 45, the magnitude comparator 50, and the like, which have already been described. Sign.

Reference numeral 70 denotes a personal computer (personal computer). 71 is a main CPU of the personal computer 70;
Is a memory device, 73 is a communication interface, 74 is a timer, 75 is a CRT, and 76 is an operation keyboard. The communication interface 73 is connected to the communication interface 13 of the test power supply 10 and the electronic watt-hour meter 20 by the communication line 16.
And the command interface and the data can be exchanged with each other. Although not shown, the display is connected to the personal computer 10.

Further, the communication interface 73 of the personal computer 70 can be connected to the communication interface 21 of the plurality of electronic watt-hour meters 20 so that the electronic watt-hour meter 20 to be adjusted can be connected.
Are connected in parallel, and each of them is capable of exchanging command commands and data with the personal computer 70.

The memory device 72 has an error adjustment program and power factor adjustment registers 61 to 63, a light load adjustment register 6
4. Each adjustment initial value to be read into the rated reference value register 65, the inter-element balance adjustment registers 66 and 67, the rated constant pulse value WK, and the power factor constant pulse value WKP is stored.

The output of the test power supply 10 is connected to the terminal of the electronic watt-hour meter 20 by a dedicated connector (not shown), and at the same time, the communication interfaces 13, 21 and 73 are connected by the communication line 16. In this state, the operation keyboard 7
When an adjustment start command is input from Step 6, an adjustment operation is performed in accordance with the flowcharts of FIGS.

(1) The adjustment initial value is transmitted from the personal computer 70, and the adjustment initial value is read into the connected electronic watt-hour meters 20 (steps 301, 241 and 242). (2) When performing the rated load adjustment (tentative F-value setting) of the coarse adjustment before executing the balance adjustment between the elements after step 302 in FIG. 10, steps 312 to 318 described later.
Here, the same procedure is performed. However, since the adjustment is a rough adjustment, the error range is increased.

(3) The personal computer 70 is connected to the test power supply 1 through the communication line 16 in order to execute the balance adjustment between the elements.
To 0, an instruction is issued to only the R phase to supply imaginary load power equivalent to a rated current, a rated voltage, and a power factor of 1.00 (step 302). (4) Upon receiving the command to supply the imaginary load power to the R phase, the test power supply 10 supplies the imaginary load power having the rated current, the rated voltage, and the power factor 1.00 to the R phase (step 103).

(5) If the power supply is supplied for a predetermined time, for example, 10 seconds, by the timer 14, the control CPU 12 returns a power supply end signal via the communication line 16 (step 104). (6) When the electronic watt-hour meter 20 receives the energization end signal, it transmits the number of power pulses WR counted during energization to the personal computer 70 and stores it in the memory device 72 (steps 243 and 303).

(7) Next, the personal computer 70 instructs the test power supply unit 10 to supply only the S phase with the rated current, the rated voltage, and the imaginary load power equivalent to the power factor of 1.00 (step 304). (8) The test power supply 10 supplies the imaginary load power having the rated current, the rated voltage, and the power factor 1.00 to the S phase for a certain period of time, and returns an energization end signal (steps 105 and 106).

(9) The electronic watt-hour meter 20 reads the number of power pulses WS counted during this time, and
(Step 244). (10) The personal computer 70 stores the transmitted S-phase power pulse number WS for each electronic watt-hour meter 20, and stores the temporarily stored R-phase power pulse WR for each electronic watt-hour meter 20. D = WS / WR is determined by comparing with a number, and it is determined whether or not D is within a predetermined range (allowable error range) centered at 1.0 (steps 305 and 306).

(11) When D is out of the predetermined range, the value of the corresponding electronic watt-hour meter 20 in the direction in which D = 1.0 is transmitted to the electronic watt-hour meter 20, and 20 changes and sets the value (B2) of the balance adjustment register 66 (steps 307 and 245). (12) A confirmation flag is turned on to confirm that the changed and set B2 value is within the allowable error range (step 308).

(13) Next, D = WS / WR of all of the connected electronic watt-hour meters 20 is calculated by the steps 306 to 306.
08 is executed (step 309). (14) Steps 306 to 311 are repeated until all the n units are within the allowable error range, and the process proceeds to the T-phase balance adjustment. The balance adjustment of the T phase is the same procedure as the balance adjustment of the S phase, and the description is omitted.

(15) In the rated load adjustment, the PC 70
Rated power to R-phase, S-phase, and T-phase from
A command is issued to supply imaginary load power equivalent to a rated voltage and a power factor of 1.00 (step 312). (16) The test power supply 10 supplies imaginary load power with a rated current, a rated voltage, and a power factor of 1.00 to all the phases for a certain period of time, for example, 10 seconds, and returns an energization end signal (step 10).
9, 110).

(17) The electronic watt-hour meter 20 reads the number of power pulses W0 counted during this time, and
0 (step 246). (18) The personal computer 70 stores the transmitted power pulse number W0 in correspondence with each electronic watt-hour meter 20, and stores the pre-stored rated constant pulse value WK and the power pulse number W0 corresponding to each electronic watt-hour meter 20. Then, D = W0 / WK is determined, and it is determined whether D is within a predetermined range centered at 1.0 (allowable error range) (steps 313 and 314).

(19) When D is out of the predetermined range, the value of the corresponding electronic watt-hour meter 20 in the direction of D = 1.0 is transmitted to the electronic watt-hour meter 20, and The value (F) of the 20 rated reference value register 65 is changed and set (steps 315 and 247). (20) In order to confirm that the changed F value is within the allowable error range, the confirmation flag is turned on (step 316), and thereafter, steps 314 to 318 are repeated until all the n units enter the allowable error range. Proceed to power factor adjustment.

(21) In the power factor adjustment, first, the personal computer 70
Commands the test power supply 10 to supply only the R phase with a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 0.50 through the communication line 16 (step 320). (22) The test power supply 10 supplies power of the rated current, the rated voltage, and the power factor of 0.50 to the R phase for a predetermined time, for example, 10 seconds, and returns an energization end signal (steps 111 and 11).
2).

(23) The electronic watt-hour meter 20 transmits the number of power pulses WPR counted during this period to the personal computer 70 (step 248). (24) The personal computer 70 transmits the transmitted power pulse number WPR
Is stored in correspondence with each electronic watt-hour meter 20, and step 30
In step 1, comparison is made with the power factor constant pulse numerical value WPK read in advance to obtain D = WPR / WPK, and it is determined whether or not D is within the allowable error range (steps 321 and 322).

(25) When D is outside the allowable error range, the power factor adjustment register 61 (P1) sends a value in the direction of D = 1.0 to the electronic watt-hour meter 20, and the electronic power watt-hour meter 20 changes and sets the power factor adjustment register 61 (P1) (step 249). (26) In order to confirm that the changed F value is within the allowable error range, the confirmation flag is turned on (Step 324), and thereafter, Steps 320 to 327 are repeated until all the n units enter the allowable error range. . Hereinafter, the power factor adjustment of the S phase and the T phase is performed by the same processing, and the process proceeds to the light load adjustment.

(27) In light load adjustment, the personal computer 70 transmits the R phase, the S phase, and the T phase to the test power supply 10 through the communication line 16.
A command is issued to the phase to supply imaginary load power equivalent to 10% of the rated current, rated voltage, and power factor of 1.00 (step 328). (28) The test power supply 10 supplies 10% of the rated current, the rated voltage, and the power factor of 1.00 to all the phases for a certain period of time, for example, 10 seconds, and returns an energization end signal (step 11).
7, 118).

(29) The electronic watt-hour meter 20 transmits the number of power pulses WL counted during this period to the personal computer 70 (step 250). (30) The personal computer 70 transmits the transmitted power pulse number WL.
Is stored in correspondence with each electronic watt-hour meter 20, and step 30
In step 1, a comparison is made with the previously read rating constant pulse numerical value WK to obtain D = 10 * WL / WK, and it is determined whether D is within an allowable error range centered at 1.0 (step 3).
29, 330).

(31) When D is out of the allowable error range, the value (L) of the light load adjustment register 64 of the electronic watt-hour meter 20
Is transmitted to the electronic watt-hour meter 20 to change the value (L) of the light load adjustment register 64 (steps 331 and 251). (32) In order to confirm that the changed L value is within the allowable error range, the confirmation flag is turned on (step 332), and thereafter, steps 328 to 334 are repeated until all n units enter the allowable error range. . When all the n units fall within the allowable error range, a message indicating that the error adjustment is completed is displayed.

As described above, the personal computer 70 has the initial set values, the adjustment program, the command to the test power supply 10 and the like, and the test power supply 10 and the plurality of electronic wattmeters 20 are provided.
Is connected by the communication line 16 via the communication interfaces 13, 21, 73, and the error is adjusted, so that the adjustment program can be easily changed, the memory capacity of the electronic watt-hour meter 20 can be reduced, and the cost can be reduced. Since error adjustment of the plurality of electronic watt-hour meters 20 can be performed, mass productivity is improved.

Embodiment 4 FIG. In this embodiment, the functions of the personal computer of the third embodiment are incorporated in a test power supply. FIG. 14 is a diagram showing a configuration of the fourth embodiment. The memory device 72 provided in the personal computer is built in the test power supply device 10, and the CPU of the personal computer is used.
Are also used by the control CPU 12. Although not shown, the display is connected to the test power supply 10 and used. The adjustment procedure is the same as in the third embodiment, and a description thereof will be omitted. In the fourth embodiment, the test equipment can be made more compact than in the third embodiment.

Embodiment 5 In the configuration of the third embodiment, the error is adjusted by comparing the imaginary load power supplied from the test power supply device 10 and the number of power pulses according to the power supply time with the reference pulse number, but the current and voltage during the power supply time are adjusted. The accuracy of the electronic watt-hour meter 20 depends on the fluctuation of the power consumption and the accuracy of the energization time. Therefore, a high-performance test power supply 10 must be prepared. For this,
A method using a high-precision reference meter is used for adjusting the error of the watt hour meter. The fifth embodiment shows a configuration of error adjustment using this reference instrument.

FIG. 15 is a connection diagram for automatic adjustment of an electronic watt-hour meter according to a fifth embodiment of the present invention. In the figure, 1, 10 to 16, 20, 21, 31, 32, 40,
Reference numerals 61 to 69 and 70 to 76 are the same as those described in the third embodiment. Reference numeral 80 denotes a reference meter, which employs an electronic watt-hour meter whose accuracy is adjusted to be extremely high.

A communication interface 81 of the reference meter 80 is connected to the communication interface 73 of the personal computer 70 through the communication line 16. The electronic watt-hour meter can transmit the count power pulse number to the personal computer 70, but ignores the adjustment setting change command from the personal computer 70. A counter 77 in the personal computer 70 counts the number of counting power pulses from the reference meter 80.

The output of the test power supply 10 is connected to the terminals of the reference meter 80 and the electric watt-hour meter 20 by a dedicated connector (not shown), and at the same time, the communication interface 1 is connected.
The communication lines 16 are connected between 3, 21, 73 and 81. When an adjustment start command is input from the operation keyboard 76 in this state, the adjustment operation is performed according to the flowcharts of FIGS. The same processing contents as those in FIGS. 10 to 13 of the third embodiment are denoted by the same step numbers in the flowchart of the fifth embodiment.

(1) The adjustment initial value is transmitted from the personal computer 70, and the adjustment initial value is read into the connected electronic watt-hour meters 20 (steps 301, 241 and 242). (2) When performing the rated load adjustment (F value setting) of the coarse adjustment before executing the balance adjustment between the elements after step 302 in FIG. 13, the same procedure as steps 312 to 318 described later is executed. . However, since the adjustment is a rough adjustment, the error range is increased.

(3) The personal computer 70 is connected to the test power supply 1 through the communication line 16 in order to perform the balance adjustment between the elements.
To 0, an instruction is issued to only the R phase to supply imaginary load power equivalent to a rated current, a rated voltage, and a power factor of 1.00 (step 302). (4) Upon receiving the command to supply the imaginary load power to the R phase, the test power supply 10 supplies the imaginary load power having the rated current, the rated voltage, and the power factor 1.00 to the R phase (step 103). (5) With this energization, the reference meter 80 and the electronic watt-hour meters 20 perform power pulse counting. Reference instrument 80
Is transmitted to the personal computer 70 through the communication line 16 (step 401) and counted by the counter 77.

(6) The personal computer 70 monitors the number of pulses counted by the counter 77, and when the number reaches a predetermined number, instructs the test power supply 10 to stop power supply and stops power supply (steps 351, 352, 121). Here, the predetermined number of counting pulses is based on the accuracy of the watt hour meter. For example, a meter having an accuracy of 0.1% has a minimum of 1,000 reference pulses for calculating an error judgment and an accuracy of 0.01%. Then 1000
What is necessary is just to obtain the number of zero pulses. (7) The personal computer 70 transmits the number of power pulses WR counted during power supply to each electronic watt-hour meter 20 to the personal computer 70 and stores it in the memory device 72 (step 24).
3, 303).

(8) Next, the personal computer 70 instructs the test power supply 10 to supply only the S phase with a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 1.00. Then, an imaginary load power having a rated voltage and a power factor of 1.00 is supplied to the S phase (steps 304 and 105). (9) When the R-phase is energized, the reference meter 80 and each electronic watt-hour meter 20 perform power pulse counting, and the reference meter 80
Are counted by the counter 77 (step 402).

(10) The number of pulses counted by the counter 77 is monitored, and when the number reaches a predetermined number, a power supply stop instruction is issued to the test power supply 10 to stop power supply (steps 353 and 35).
4, 122). (11) Thereafter, the personal computer 70 stores the transmitted number of power pulses WS of the S phase in correspondence with each electronic watt-hour meter 20, and stores the stored R-phase power pulses corresponding to each electronic watt-hour meter 20. In contrast to the number of WRs, each electronic watt-hour meter 20 sets the change of the value (B2) of the balance adjustment register 66 and the change of the value (B3) of the T-phase balance register 67 in the above-described embodiment. 3 and the description is omitted.

(12) In the rated load adjustment, the personal computer 70 instructs the test power supply 10 to supply the rated current, the rated voltage, and the imaginary load power corresponding to the power factor 1.00 to the R, S, and T phases. The test power supply 10 supplies imaginary load power having a rated current, a rated voltage, and a power factor of 1.00 to the R, S, and T phases (steps 312 and 109). (13) With this energization, the reference meter 80 and each electronic watt-hour meter 20 perform power pulse counting, and the power counting pulses of the reference meter 80 are counted by the counter 77 (step 403).

(14) The personal computer 70 monitors the number of counting pulses of the counter 77, and when the number reaches the predetermined number WK, instructs the test power supply 10 to stop power supply and stops power supply (steps 355, 356, 123). (15) The personal computer 70 receives and stores the number of power pulses W0 counted by the electronic watt-hour meters 20 during the energization (step 313), and corresponds to the count pulse number WK of the counter 77 and the corresponding electronic watt-hour meter 20. The value (F) of the rated reference value register 65 of the electronic watt-hour meter 20 is changed and set in comparison with the power pulse number W0 (steps 314 to 315, 24).
7). (16) The following is the same as the third embodiment, and the description is omitted.

(17) In the power factor adjustment, the personal computer 70 instructs the test power supply device 10 to supply only the R phase with a rated current, a rated voltage, and an imaginary load power equivalent to a power factor of 0.50. Rated current, rated voltage, power factor 0.50 power R
The phases are energized (steps 320, 111). (18) By this energization, the reference meter 80 and each electronic watt-hour meter 20 perform power pulse counting, and the power counting pulses of the reference meter 80 are counted by the counter 77 (step 404).

(19) The personal computer 70 monitors the number of pulses counted by the counter 77, and when it reaches a predetermined number WPK, instructs the test power supply 10 to stop power supply and stops power supply (steps 357, 358, and 125). (20) The personal computer 70 receives and stores the number of power pulses WPR counted by each electronic watt-hour meter 20 during this energization (step 321), and corresponds to the counted pulse number WPK of the counter 77 and each electronic watt-hour meter 20. In contrast to the number of power pulses WPR of
D = WPR / WPK is obtained, and the power factor adjustment register 61 (P1) is changed and set so that D falls within the allowable error range (steps 322 to 324, 249). (21) The following processes are performed by the same processing as in the third embodiment.
Phase and T phase power factor adjustments are performed, and proceed to light load adjustment.

(22) In the light load adjustment, the personal computer 70 supplies the test power supply 10 with the imaginary load power equivalent to the rated 10% current, the rated voltage, and the power factor of 1.00 to the R, S, and T phases. And the test power supply 10 supplies 10% of the rated current, rated voltage, and power factor 1.00 to all phases (step 3).
28, 117). (23) With this energization, the reference meter 80 and each electronic watt-hour meter 20 perform power pulse counting, and the power counting pulses of the reference meter 80 are counted by the counter 77 (step 405).

(24) The personal computer 70 monitors the number of counting pulses of the counter 77, and when it reaches the predetermined number WLK, instructs the test power supply 10 to stop power supply and stops power supply (steps 359, 360, 126). (25) The personal computer 70 collects and stores the number of power pulses WL of each of the electronic watt-hour meters 20 during energization (step 32).
9).

(26) Then, the number of counting pulses WLK in the counter 77 and the number of collected power pulses WL are compared for each electronic watt-hour meter 20, and D = WL / WK is calculated.
Is set within the allowable error range.
Is changed and set (steps 330 to 322,
251). (27) Thereafter, steps 328 to 334 are repeated until all of the n units fall within the allowable error range. When all the n units fall within the allowable error range, a message indicating that the error adjustment is completed is displayed.

In the fifth embodiment, the reference meter 80
Although the example in which the comparison between the electric power meter 20 and the power counting pulse of the electronic watt-hour meter 20 are processed by the program of the personal computer 70 has been described, the same effect can be obtained even if this part is implemented using a rotary counter. For example, when a rotary counter is used, a rotary counter is used instead of the counter 77 in FIG. 15, the number of power pulses WL of each electronic watt-hour meter 20 is counted by + (plus), and the number of power pulses WLK of the reference meter 80 is calculated. -(Minus) count. The value to be counted is (the number of power pulses WL of the electronic watt-hour meter)-(the number of power pulses WLK of the reference meter), and the error is adjusted so that this difference falls within a predetermined range.

As described above, in the configuration of the fifth embodiment, the setting value of each adjustment register is compared with the power counting pulse of the electronic watt-hour meter 20 based on the power counting pulse of the reference meter 80. Therefore, the reference meter 80 and the electronic watt-hour meter 20 have the same power supply value even if there is a voltage fluctuation of the imaginary load power supplied from the test power supply device 10 during the adjustment operation, an error in the supply time, or the like. Because we know at the level,
As for the accuracy of error adjustment, if the accuracy of the reference meter 80 is maintained, the accuracy of the electronic watt-hour meter 20 can easily enter the compensation range. Further, it is possible to easily change the adjustment program, reduce the memory capacity of the electronic watt-hour meter 20, and execute the simultaneous error adjustment of the plurality of electronic watt-hour meters 20 described in the third embodiment.

Embodiment 6 FIG. In this embodiment, the functions of the personal computer of the fifth embodiment are incorporated in a test power supply. FIG. 20 is a diagram showing a configuration of the sixth embodiment. The memory device 72 provided in the personal computer is built in the test power supply 10 and the C
The PU is also used by the control CPU 12. Although not shown, the display is connected to the test power supply 10 and used. The adjustment procedure is the same as that in the fifth embodiment, and thus the description is omitted. It can be configured more compactly than in the fifth embodiment.

[0112]

As described above, according to the electronic watt-hour meter and the error adjusting method of the present invention, since the error can be automatically adjusted, the productivity in mass production can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an error adjustment system for an electronic watt-hour meter according to Embodiment 1 of the present invention.

FIG. 2 is a flowchart of error adjustment according to the first embodiment of the present invention.

FIG. 3 is a flowchart of error adjustment according to the first embodiment of the present invention.

FIG. 4 is a flowchart of error adjustment according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram of an error adjustment system for an electronic watt-hour meter according to a second embodiment of the present invention.

FIG. 6 is a flowchart of error adjustment according to the second embodiment of the present invention.

FIG. 7 is a flowchart of error adjustment according to the second embodiment of the present invention.

FIG. 8 is a flowchart of an error adjustment according to the second embodiment of the present invention.

FIG. 9 is a configuration diagram of an error adjustment system for an electronic watt-hour meter according to Embodiment 3 of the present invention.

FIG. 10 is a flowchart of error adjustment according to Embodiment 3 of the present invention.

FIG. 11 is a flowchart of error adjustment according to Embodiment 3 of the present invention.

FIG. 12 is a flowchart of error adjustment according to Embodiment 3 of the present invention.

FIG. 13 is a flowchart of error adjustment according to the third embodiment of the present invention.

FIG. 14 is a configuration diagram of an error adjusting system for an electronic watt-hour meter according to a fourth embodiment of the present invention.

FIG. 15 is a configuration diagram of an error adjustment system for an electronic watt-hour meter according to a fifth embodiment of the present invention.

FIG. 16 is a flowchart of error adjustment according to Embodiment 5 of the present invention.

FIG. 17 is a flowchart of error adjustment according to Embodiment 5 of the present invention.

FIG. 18 is a flowchart of error adjustment according to Embodiment 5 of the present invention.

FIG. 19 is a flowchart of error adjustment according to Embodiment 5 of the present invention.

FIG. 20 is a configuration diagram of an error adjustment system for an electronic watt-hour meter according to Embodiment 6 of the present invention.

FIG. 21 is a configuration diagram showing error adjustment of a conventional electronic watt-hour meter.

FIG. 22 is a diagram showing error characteristics of an electronic watt-hour meter.

FIG. 23 is a configuration diagram of another conventional error adjusting system for an electronic watt-hour meter.

[Explanation of symbols]

Reference Signs List 1 imaginary load test power supply, 10 test power supply device, 11 power supply switching device, 12 control CPU, 13, 21, 73, 81 communication interface 14 ROM, 16 communication line, 17 supply destination switching means, 20 electronic watt-hour meter, 22 Non-volatile storage device (EPROM), 2
3 adjustment start switch, 31 current transformer,
32 transformers, 38 counters,
39 display unit, 40 arithmetic control unit,
41 CPU, 42 current A / D conversion circuit, 43 voltage A / D conversion circuit, 44 multiplier, 45 adder, 46 digital low-pass filter, 47 light load adjustment adder,
51 balance adjustment multiplier, 61-63 power factor adjustment register, 64 light load adjustment register,
65 Rating reference value register, 66, 67 Balance adjustment register, 70 Personal computer, 71
Main CPU, 72 memory devices, 7
6 operation keyboard, 80 reference instruments,

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI G01R 35/04 G01R 35/04 E (58) Field surveyed (Int.Cl. ⁷ , DB name) G01R 35/00 G01R 35 / 04 G01R 21/00-22/00 130 G01R 11/00-11/66

Claims (6)

(57) [Claims] 1. A digital multiplier for converting an input voltage / current into a power pulse number proportional to a power amount, and a balance adjustment / power factor for adjusting an error in converting the power pulse number of the digital multiplier. Error adjustment items such as adjustment
An adjustment register for holding the adjustment value of each adjustment point according to the following; a memory device for storing the error adjustment program and each specified value; and an error adjustment item using the error adjustment program.
Switching to each adjustment point according to the adjustment
The output of the power supply type corresponding to the point
And instruction means for instructing to, using the above error adjustment program, the power number of pulses in the power supply type of output the corresponding instruction test power supply predetermined time obtained by inputting to the digital multiplier output from the Adjusting value setting means for comparing with a prescribed value of the memory device corresponding to the instruction, deriving an adjustment value for adjusting the comparison result to fall within a predetermined error range, and writing the adjustment value in the adjustment register. Electronic watt-hour meter. 2. The electronic watt-hour meter according to claim 1, further comprising: a test power-supply device including a power-supply type switching unit for switching and outputting a predetermined power-supply type. The electronic watt-hour meter receiving the output is converted into the number of power pulses, and the adjustment value is derived and set by the adjustment value setting means. An error adjusting method for an electronic watt-hour meter. 3. The error adjusting method for an electronic watt-hour meter according to claim 2, wherein a plurality of electronic watt-hour meters are connected to a test power supply, and the test power supply switches and outputs a predetermined power supply type. Power supply type switching means and the output of the electronic wattmeter 1
A test power supply device comprising a supply destination switching means for switching to supply the individual electric power and a control means, wherein the control means receives any instruction from the instruction means of the electronic wattmeter, It is determined which type of power supply is to be switched to the power meter, and the switching of the power supply type and the switching of the supply destination are combined to adjust all adjustment points of the plurality of electronic watt-hour meters. An error adjusting method for an electronic watt-hour meter, characterized in that: 4. An electronic watt-hour meter to be subjected to error adjustment,
Power supply type switching means for switching and outputting to different power supply types
The test power supply unit to be connected to the arithmetic unit
The meter measures the input voltage and current with a power pulse proportional to the amount of power.
Multiplier that converts the number of pulses and adjusts the error when converting the number of power pulses of this digital multiplier
Error adjustment items such as balance adjustment and power factor adjustment
Adjustment register that holds the adjustment value of each adjustment point according to
And a transmission enabling transmission of the power pulse number to the arithmetic device.
Means for adjusting the adjustment value input from the arithmetic unit to the adjustment register
Electronic watt-hour meter having adjustment value setting means for writing to a power supply
And the arithmetic unit uses an error adjustment program of the electronic watt-hour meter.
And a memory device storing the specified values and the error adjustment program.
Switching to each adjustment point according to the adjustment
The output of the power supply type corresponding to the point
Means for instructing the memory device corresponding to the instruction and the number of power pulses in a predetermined time obtained by inputting the output from the test power supply to the digital multiplier using the error adjustment program . An arithmetic unit comprising: an adjustment value deriving unit that derives an adjustment value that adjusts the comparison result to fall within a predetermined error range. The electronic watt-hour meter receiving the output is converted into the number of power pulses and output to the arithmetic unit, and the arithmetic unit is received with the number of power pulses. Wherein the adjustment value deriving means derives an adjustment value, and the derived adjustment value is written and set in an adjustment register by the adjustment value setting means of the electronic wattmeter. How to adjust the error of the meter. 5. An electronic watt-hour meter according to claim 4, further comprising:
Power source type switching means for switching to the source type and outputting
The test power supply, the arithmetic unit, and the reference meter are connected, and the watt-hour meter measures the input voltage and current in proportion to the amount of power.
Digital multiplier that converts the number of power pulses into a fixed number of power pulses, and adjusts the error of the digital multiplier when converting the number of power pulses.
Error adjustment items such as balance adjustment and power factor adjustment
Adjustment register that holds the adjustment value of each adjustment point according to
And a transmission enabling transmission of the power pulse number to the arithmetic device.
Means for adjusting the adjustment value input from the arithmetic unit to the adjustment register
Electronic watt-hour meter having adjustment value setting means for writing to a power supply
With use, the reference meter have the same digital multipliers and said electronic power meter, using a calibrated reference instrument to the power pulse number obtained for a given input as a reference value, and, The arithmetic unit uses the error adjustment program of the electronic watt-hour meter and a memory device in which each specified value is stored, and uses the error adjustment program to adjust the error adjustment item.
Switching to each adjustment point according to the adjustment
The output of the power supply type corresponding to the point
Means for instructing the test, and the number of power pulses in a predetermined time obtained by inputting the output from the test power supply to the digital multiplier of the electronic wattmeter using the error adjustment program; and Compare the output from the power supply to the number of power pulses at a predetermined time obtained by inputting the digital multiplier of the reference instrument,
An arithmetic unit having an adjustment value deriving unit for deriving an adjustment value for adjusting the comparison result to fall within a predetermined error range; and the test power supply unit is a power supply corresponding to an instruction from an instruction unit of the arithmetic unit. The electronic watt-hour meter and the reference device receiving the output are converted into the number of power pulses and output, respectively, and the arithmetic unit compares the output power pulse numbers with each other. An adjustment value corresponding to the comparison result is derived and output by the adjustment value deriving means, and the output adjustment value is written and set in the adjustment register by the adjustment value setting means of the electronic wattmeter. Characteristic error adjustment method for electronic watt-hour meter. 6. The electronic power meter error adjustment method according to claim 4, wherein the test power supply device uses a test power supply device having a built-in arithmetic unit. How to adjust the error of the meter.