JP3037578B2 - Electric energy sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a load survey branch circuit of the power distribution line, the peak cut operation of the air conditioning equipment, the amount of power sensor used in the power generation efficiency integrated systems such as a distributed power source
The dependency, details wire bus voltage to be measured, to measure the current, about the amount of power <br/> sensor to be transmitted to the communication line as a digital signal.

[0002]

2. Description of the Related Art Conventionally, an electric energy sensor used for a load survey or the like in a distribution circuit branch circuit has been of an analog type based on time division.

[0003]

Therefore, when trying to measure a large number of variables such as power, voltage, current, power factor, and reactive power, an independent circuit is required for each variable. Moreover, the obtained measured values cannot be sent to the communication line as it is. For this reason, there has been a problem that the electric energy and the like of each branch circuit cannot be totaled in real time. The present invention has been made to solve the above problems, it is an object to provide a power amount cell <br/> down service capable of simultaneously measuring each variable with a simple structure is there.

[0004]

In order to achieve the above object, the present invention provides a CT (current transformer) attached to one of the wiring buses to be measured.
And PT connected between two wiring buses to be measured
(Potential transformer),
From the detected values of CT and PT, the electric energy and the effective voltage value,
A calculation unit for calculating the effective current value;
Communication to send the effective voltage and effective current to the communication line.
Power sensor with an interface circuit,
Main body and table formed by dividing the entire force sensor into two
And bolt fixing means for detachably fixing the main body and the base
And to insert the wiring bus into the contact surface between the main unit and the base
The two parallel grooves formed and one of these grooves
A two-part CT buried in both the main body and the table;
Each is formed by penetrating both groove portions of the body upward.
Coaxially inside each pair of connection holes and each connection hole
A metal terminal consisting of a female screw arranged, and this metal terminal
PT connected between metal terminals and blade formed at the tip
And the female screw portion of the metal terminal
The tip is electrically connected to the wiring bus by screwing into
And a cutting edged bolt .

[0005]

According to the present invention, the two grooves of the main body and the base are provided in the groove.
Insert the wiring bus, abut the main body and the base, and fix with bolts
It is fixed integrally by means. Next, cut into the connection hole.
Insert a bolt with a blade and screw it into the metal terminal. It
The CT is attached to one of the wiring buses to be measured
At the same time, PT is connected between two wiring buses to be measured.
Is done. Current detected in CT and detected in PT
From the voltage, the operation amount and the effective value of the voltage,
The effective current value is calculated and the communication interface circuit is
Sent to the communication line via the Internet.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an electrical configuration of a power sensor according to the present invention. In the drawing, reference numeral 1 denotes a CT having a two-part structure attached to a wiring bus L, and a secondary winding wound around one of the CTs is connected to the analog amplifier circuit 3. PT2 is connected between the wiring bus L and the wiring bus N, and the secondary windings wound around the PT2 are connected to the analog amplifier circuit 3 and the constant voltage power supply 6, respectively.

The analog amplifier circuit 3 includes an operational amplifier OP1
Differential amplifying circuit 4 consisting of resistors OP1 to OP3 and resistors R1 to R8
And a voltage differential amplifier circuit 5 including operational amplifiers OP4 to OP6 and resistors R9 to R13. CT1
Are amplified by the current differential amplifier circuit 4 and then sent to the filter 7. Filter 7 is A /
To prevent an error due to aliasing noise from occurring in the D converter, a frequency equal to or more than 以上 of the sampling frequency is sufficiently suppressed and sent to the A / D converter 11. The voltage detected by PT2 is amplified by voltage differential amplifier circuit 5 and then sent to filter 8. The filter 8 sufficiently suppresses a frequency equal to or more than の of the sampling frequency and sends it to the A / D converter 12 so that an error due to aliasing noise does not occur in the A / D converter.

A / D converters 11 and 12 sample the instantaneous values of the input analog signals of voltage and current at a cycle of 250 kHz and convert them into digital values proportional to the values. The signal is sent to the multiplication circuit 13 and the frequency dividing circuit 16 or the frequency dividing circuit 17. Multiplication circuit 13
Multiplies the digital values of the input voltage and current and sends them to the integrating circuit 14 as an instantaneous value power signal. Integration circuit 14
, Time-integrates the input instantaneous value power signal and sends it to the pulse conversion circuit 25. The pulse conversion circuit 25 converts the input integration result into a pulse train having a frequency proportional to the amount of electric power, and sends the pulse train to the dive prevention circuit 15.

The latent movement prevention circuit 15 stops sending a signal when the input pulse train is smaller than a preset frequency value, and sends a power signal to the frequency dividing circuit 18 when the input pulse train is larger than the preset value. . The latent motion prevention circuit 15 facilitates processing of a power signal in the CPU 21 described later. Next, the frequency dividing circuits 16 to 18 divide the input voltage, current, and power pulse signals, and
Send to The clock of the clock circuit 19 and the CP
A / D converters 11 and 12 and circuit 13 are operated by an operation command from control circuit 20 which operates based on the command from U21.
~ 18 operate.

The A / D converters 11 and 12 and the circuit 13
The digital operation circuit 9 is constituted by 〜20 and 25. The CPU 21 functions as a power amount calculation unit and an effective value calculation unit, counts voltage, current, and power pulse signals input from the frequency divider circuits 16 to 18 and stores the count values, and at regular time intervals. The value is averaged and sent to the communication interface circuit 22.

The CPU 21 controls the control circuit 20 as an operation program, in addition to a power amount integration program, a current pulse averaging program, a voltage pulse averaging program, a voltage, current, and power amount storage programs relating to the above-described processing. Sequence program for communication, a communication procedure control program of the communication interface circuit 22,
It contains rating adjustment data, phase adjustment data, and the like.
Further, a light emitting diode 23 is connected to the CPU 21 by a resistor R14.
During the operation of the CPU 21, the light emitting diode 23 is turned on to visually confirm that the CPU 21 is operating.

The communication interface circuit 22 includes a CPU
Based on the control from the CPU 21, the voltage, current, and power values output from the CPU 21 are transmitted to the communication line 24. A photocoupler is connected to the communication interface circuit 22 to electrically insulate the communication line 24 from the CPU 21. Although not shown, a central data totaling device is connected to the other end of the communication line 24, and the power amount, voltage,
A current signal processing system is configured.

[0013] The central data totaling device sequentially stores the transmitted values in an internal memory, and based on the values, the power amount, the maximum power,
Power usage trends, voltage and current changes, reactive power,
Calculate each measurement item such as power factor and frequency change. Each of the calculated values is stored again at a predetermined address in the memory, and is output to the outside as necessary to be used for desired control means. The addresses of these memories are specified by a sequence program. In addition, the central data totaling device includes a plurality of communication interface circuits, and can receive and process measurement data from a plurality of electric energy sensors in parallel.

FIG. 2 is an external view showing the structure of the electric energy sensor of FIG. 1, and FIG. 3 is a sectional view taken along line AA of FIG. FIG.
As shown in FIG. 3, the external shape of the electric energy sensor is formed in an L-shape, and as shown in FIG. 3, the main body 31 and the base 32 are formed in a two-part structure. Two grooves 33, 34 each having a quadrant in cross section are formed in parallel on the contact surface between the main body 31 and the base 32, and the wiring buses L, N are sandwiched therebetween.
The main body 31 and the base 32 are fixed by contacting the main body 31 and the base 32 and inserting wing bolts 35 and 36 into through holes formed in the main body 31 and screwing into the cap nuts embedded in the base 32 side. And become one.

At positions of the main body 31 corresponding to the grooves 33, 34, holes 37, 38 are formed perpendicular to the contact surface, respectively.
Metal terminals 41, 4 having internal threads formed on the inside thereof
2 is inserted. When the bolts 43, 44 with cutting blades are screwed into the metal terminals 41, 42, the ends thereof penetrate through the insulating coatings of the wiring buses L, N and come into contact with the core wires to be electrically connected. PT2 is embedded in the main body 31 at an intermediate position between the metal terminals 41 and 42, and its secondary winding is connected to the metal terminals 41 and 42, though not shown.

When the buses L and N are sandwiched between the PT2 and the primary windings of the PT2 are energized by screwing the cutting edge bolts 43 and 44, the constant voltage power supply 6 is activated and the analog amplifier circuit is operated. 3. A current is supplied to the digital operation circuit 9 and the CPU 21 to be in an operation state. Further, the main body 31 and the base 32 around the groove 33 have a two-part CT structure.
1 are buried, and the secondary winding is located on the main body 31 side. The secondary winding of CT1 and the secondary winding of PT2 are connected to a circuit unit 45 embedded in the main body 31.

In the circuit section 45, the analog amplification circuit 3, the digital operation circuit 9, and the CPU 21 of FIG. 1 are covered with a conductive shield plate 39, and the ground terminal E is connected thereto. The upper surface of the circuit section 45 of the main body 31 has C
A peephole 46 for viewing the light emitting diode 23 indicating the operation of the PU 21 is formed. The communication interface circuit 22 is buried at an end face of the main body 31 and at a position on the left side of the sandwiched wiring bus L, and the communication line 24 is connected via a connector 47. Mounting holes 48 and 49 are formed in the thickness direction of both ends of the main body 31 so as to penetrate the main body 31 and the base 32. These mounting holes 48,
By inserting a bolt or the like into 49 and fixing it to a wall or the like, the electric energy sensor is supported.

FIG. 4 shows two electric energy sensors of FIG.
An example is shown in which three wiring buses L, N, and R are attached. After attaching the electric energy sensor 50 to the wiring buses L and N as shown in FIG.
An example is shown in which the sensor is rotated by 0 degrees to face the electric energy sensor 50 and attached to the wiring buses N and R. Here, the electric energy sensor 50 measures the voltage between the wiring buses L and N and the current of the wiring bus L, and the electric energy sensor 60 measures the voltage between the wiring buses N and R and the current of the wiring bus R.

In this case, since the narrow portions of the electric energy sensors 50 and 60 have almost half the dimensions of the other wide portions, the narrow portions are overlapped with each other by facing each other.
The electric energy sensors 50 and 60 can be efficiently housed and arranged in a narrow space. As a result, for the other multi-phase multi-wire wiring buses such as a single-phase three-wire and a three-phase three-wire, using the above-described power sensor, the measured values are summed up, and the power amount and the like can be easily and efficiently calculated. Measurement data can be collected.

[0020]

As described above , according to the present invention, two
Insert the wiring bus into each groove of
It is fixed integrally using bolt fixing means, and then
Insert a bolt with a cutting blade into the connection hole and screw it into the metal terminal.
I will. As a result, one of the wiring buses to be measured is CT
Is attached, and the two wiring buses to be measured
Are connected during the period. Thus, according to the present invention
And simplify the installation of the electric energy sensor on the wiring bus
It becomes possible.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an electrical configuration of an embodiment of a power sensor according to the present invention.

FIG. 2 is an external view showing the structure of the electric energy sensor of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an explanatory view showing another example of mounting the electric energy sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CT 2 PT 3 Analog amplifier circuit 4 Current differential amplifier circuit 5 Voltage differential amplifier circuit 6 Constant voltage power supply 7, 8 Filter 9 Digital operation circuit 11, 12 A / D converter 13 Multiplication circuit 14 Integration circuit 15 Circuit 16-18 Frequency divider circuit 19 Clock circuit 20 Control circuit 21 CPU 22 Communication interface circuit 23 Light emitting diode 24 Communication line 25 Pulse conversion circuit 31 Main body 32 units 33, 34 Groove 35, 36 Butterfly bolt 37, 38 hole 39 Shield plate 41 , 42 Metal terminal 43, 44 Bolt with cutting edge 45 Circuit part 46 Peephole 47 Connector 48, 49 Mounting hole 50, 60 Electric energy sensor E Ground terminal L, N, R Wiring bus OP1-OP6 Operational amplifier R1-R14 Resistance

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G01R 22/00 130 G01R 22/00 130J G08C 15/00 G08C 15/00 B (72) Inventor Hidetake Nakamura 5-chome, Shiba, Minato-ku, Tokyo No. 1 NEC Corporation (72) Inventor Kazuchika Koyama 1-7-1, Yurakucho, Chiyoda-ku, Tokyo Toko Electric Corporation (72) Katsuo Inoue 1-7-1, Yurakucho, Chiyoda-ku, Tokyo Toko Electric Co., Ltd. (56) References JP-A-6-27161 (JP, A) JP-A-60-210773 (JP, A) JP-A-7-35779 (JP, A) JP-A-63-187066 ( JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 11/00-11/66 G01R 21/00-22/04

Claims (1)

(57) [Claims] 1. A CT attached to one of the wiring buses to be measured, a PT connected between two wiring buses to be measured, a power amount and a voltage effective value from CT and PT detection values,
Communicates the calculation unit for calculating the effective current value, and the calculated electric energy, effective voltage value, and effective current value
In the power sensor and a communication interface circuit for sending to the line, the body and base, which are formed by bisecting the entire electric energy sensor
And a bolt fixing means for detachably fixing the main body and the base, and formed for inserting a wiring bus into a contact surface between the main body and the base.
Embedded in both the main body and the table so as to surround the two parallel grooves and one of the grooves.
Formed in the two-part structure, and penetrating both groove portions of the main body upward.
A pair of connection holes and a female screw coaxially disposed inside each connection hole.
A metal terminal, a PT connected between the metal terminal and the metal terminal, and a blade formed at the tip and inserted into the connection hole, and
By screwing into the female screw part of the metal terminal, the tip
An electric energy sensor , comprising: a bolt with a cutting blade electrically connected to a wire .