JP2002122616A - Electric energy sensor attached switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric energy sensor attached switch contributing to the space saving of non-utility generating facilities and omitting connection work of a bus-line and a VCT to realize the improvement of workability and cost reduction. SOLUTION: This electric energy sensor attached switch is provided with a make-and-break contact 3 making and breaking a main circuit conductor; a voltage sensor 4 for detecting voltage waveform from the main circuit conductor; a current sensor 5 for detecting transformed current waveform from the main circuit conductor; a signal processing part 6 for converting the voltage waveform and current waveform into a voltage signal and a current signal; an arithmetic processing part 7 for computing electric energy data from the voltage signal and current signal; and a communication interface circuit 8 for sending the electric energy data to a communication line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching device attached to a power sensor integrated with a segmented switch installed at a demarcation point of responsibility between a power company and a customer and a power sensor for measuring the customer power. About the vessel.

[0002]

2. Description of the Related Art For customers such as factories with large contract power,
Like the example shown in the explanatory diagram of the high-voltage private power receiving equipment in FIG.
The supplied power is received by the high-voltage private power receiving equipment 70 through the bus 60 branched from the power company distribution line 50. The bus bar 60 is an overhead distribution line or an underground distribution line, and is connected to a section switch 80. The segmented switch 80 has a switching contact for turning on and off the main circuit conductor that is a bus.

[0003] The high-voltage private power receiving equipment 70 is a voltage current transformer (hereinafter referred to as VC).
It is called T. ) 70a, a circuit breaker 70b, a power capacitor 70c, a transformer 70d, and a metering device 70e.
The power signal transmitted from the bus 60 passes through a VCT 70a, a circuit breaker 70b, and a power capacitor 70c to form a transformer 70d.
Is input to The transformer 70d converts the voltage of the power signal to a low voltage, and finally supplies power to the customer load 90.

[0004] The VCT 70a is installed near a service entrance for drawing the bus 60 into the high-voltage private power receiving equipment 70, and the primary side of the VCT 70a is connected to the bus 60 so that the voltage and current of the bus 60 can be adjusted to a nominal transformation ratio. It is well transformed and supplies a low voltage and a low current from the secondary side of the VCT 70a to the metering device 70e.

[0005] At this time, the metering device 70e connected to the secondary side of the VCT 70a measures, for example, the total amount of electric power used over the load system of the customer. Electricity rates are traded between the electric power company and the consumer based on the total power consumption. In addition, other than the above-described total power consumption, a device that measures various measurement targets such as a maximum customer watt-hour meter and a power factor meter that measures the maximum customer power amount can be used as the metering device 70e.

Next, the VCT 70a will be described more specifically. For example, the high-voltage private power receiving equipment 70 is 6.6 k
If it is a power receiving facility of a V high voltage customer, two instrument transformer elements (VT) connected between V and V phases and between V and W phases,
Two current transformer elements (CT) connected in series to U-phase and W-phase
And VT and CT are connected to a metering device 70e such as a watt-hour meter via a secondary terminal box. Then, as shown in the schematic structure diagram of the VCT with a partial cross section in FIG. 4, the VT, CT, and the primary side bushing are housed in an outer box, and a secondary terminal box is provided. Have been.

[0007] As an example of a high-voltage private power receiving facility for a consumer, a so-called cubicle-type high-voltage private power receiving facility, not shown, is also widely used. This cubicle-type high-voltage private power receiving equipment is characterized by being excellent in installation position, configuration flexibility, and ease of construction work.

[0008]

In general, in a high-voltage private power receiving facility, particularly a cubicle-type high-voltage private power receiving facility, maintenance of various devices for power reception is simplified as much as possible, and various devices and wirings are simply housed in a metal box. In order to reduce the required floor area as much as possible,
There was no extra space at the installation location. In addition, the high-voltage private power receiving facilities of consumers are installed in extra spaces, such as basements, staircases, and rooftop buildings, in buildings or factories, in order to preferentially secure living facilities in buildings and production facilities in factories. Often, V
The actual situation is that there is no extra space in the high-voltage private power receiving equipment where the CT is installed.

However, since the above-mentioned VCT has a configuration in which the lead wire of the primary side bushing is drawn downward from both upper sides of the outer case on both the power supply side and the load side in a C-shape,
When installing a CT, the lead wire must be connected to the bus with a radius of curvature of a certain radius or more.
Coupled with the fact that T is a large structure, it has been an obstacle to space saving. In addition, since it is necessary to secure an insulation distance in order to insulate the VT, the CT, the charging unit, and the outer case from each other in the air, it is an obstacle to space saving also from this point. When the VCTs are arranged in this manner, it has been difficult to save space.

[0010] Further, when the connection between the lead wire from the VCT primary side bushing and the bus is performed in a cubicle or a customer substation, it is difficult to perform the work in a tight space. It was low. Furthermore, when the bus is an insulated cable, the VCT
It is necessary to connect to the system, which leads to a decrease in workability and an increase in equipment cost.

In view of such a situation, the present invention contributes to the space saving of the private power receiving equipment and the bus and the VC.
It is an object of the present invention to provide a switch attached to a power sensor, which can improve workability and reduce cost by omitting connection work with T.

[0012]

According to a first aspect of the present invention, there is provided a switch attached to a power sensor, which is installed in a distribution line and detects a switching contact for turning on and off a main circuit conductor and a voltage waveform transformed from the main circuit conductor. A voltage sensor, a current sensor for detecting a current waveform transformed from the main circuit conductor, a voltage waveform detected by the voltage sensor to a voltage signal, and a current waveform detected by the current sensor to a current signal. A signal processing unit for converting each, an arithmetic processing unit for converting the voltage signal and the current signal output from the signal processing unit into digital signals and calculating various data regarding the amount of power,
A communication interface circuit for transmitting various data relating to the amount of power calculated by the arithmetic processing unit to a communication line.

According to a second aspect of the present invention, there is provided the switch with the electric energy sensor according to the first aspect of the present invention.
The voltage sensor is formed by connecting a high-side capacitor and a low-side capacitor in series between a main circuit conductor and ground, and detects a voltage waveform obtained by dividing the capacitor from a contact point between the high-side capacitor and the low-side capacitor. It is characterized by the following.

According to a third aspect of the present invention, there is provided a switch with an electric energy sensor according to the second aspect.
The high voltage side capacitor is a high voltage side ceramic capacitor, the low voltage side capacitor is a low voltage side ceramic capacitor, and the high voltage side ceramic capacitor and the low voltage side ceramic capacitor are directly connected and integrally formed with an insulating resin.

According to a fourth aspect of the present invention, there is provided a switch with an electric energy sensor according to the second aspect.
The high voltage side capacitor is a high voltage side ceramic capacitor coated with an insulating resin, the low voltage side capacitor is a low voltage side film capacitor, and the high voltage side ceramic capacitor and the low voltage side film capacitor are connected in series.

According to a fifth aspect of the present invention, there is provided a switch with an electric energy sensor according to any one of the first to fourth aspects, wherein the current sensor is a Rogowski coil, It is arranged so as to be concentric with the main circuit conductor as an axis, and detects a current waveform corresponding to the magnitude of a magnetic field generated by a current flowing through the main circuit conductor.

According to a sixth aspect of the present invention, in the switch with the electric energy sensor according to any one of the first to fourth aspects, the current sensor is an electric wire extending over the entire circumference of the ring-shaped iron core. Is a current transformer wound with a main circuit conductor disposed in a ring ring hole of the current transformer to detect a current waveform.

According to a seventh aspect of the present invention, there is provided the switch with the electric energy sensor according to the fifth or sixth aspect, wherein the bushing has a cylindrical rotating body shape having a hole through which the main circuit conductor passes. A holder for fixedly holding the current sensor along the outer peripheral surface of the bushing;
Wherein the holder is attached along the outer peripheral surface of the bushing, and fixes and holds the Rogowski coil or the current transformer at an optimal position for measurement.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of the inside of a switch attached to an electric energy sensor of the present invention installed at a responsibility demarcation point between an electric power company side and a consumer side from an overhead high voltage distribution line. This switch 1 with a power amount sensor is roughly divided into a switch unit and a power amount sensor unit. The switch unit and the power amount sensor unit are compactly housed inside the outer box 2. I have.

The switch unit is provided with an open / close contact 3 which is turned on / off by an open / close drive unit / open / close mechanism (not shown), and performs open / close operation like a conventional switch. In addition, since each part structure, such as the opening / closing contact 3 turned on / off by these opening / closing drive part / opening / closing mechanism part, is well-known, detailed description thereof is omitted. In the electric energy sensor,
A voltage sensor 4 and a current sensor 5 corresponding to the VCT, a signal processing unit 6, an arithmetic processing unit 7, and a communication interface circuit 8 are provided.

The voltage sensor 4 connects the high voltage side capacitor 4a and the low voltage side capacitor 4b to each phase of the main circuit conductor 20 on the fixed contact side of the switching contact 3 (grounding the casing to the outer box 2).
Are connected in series with each other, and the voltage between the ground of the main circuit conductor 20 on the fixed contact side is divided and sent to the signal processing unit 6.

The high voltage side capacitor 4a of the voltage sensor 4
The low voltage side capacitor 4b and the low voltage side capacitor 4b are both ceramic capacitors, and these capacitors 4a and 4b are integrally coated with an insulating resin such as an epoxy resin to form a strong solid insulator. In addition, this solid insulator
The miniaturization is achieved by also serving as a support insulator for the main circuit conductor. In this case, the supporting insulator has the same shape as the supporting insulator 9 that supports the main circuit conductor 20 on the movable contact side of the switching contact 3.

The low-voltage capacitor 4b is relatively large due to the necessity of increasing the capacitor capacity, or the volume of the molding die of the supporting insulator 9 cannot be coated to form the large low-voltage capacitor 4b. Therefore, only the high-voltage side capacitor 4a may be covered with the insulating resin. In this case, a low-cost capacitor with a simple configuration such as a polypropylene film capacitor is used as the low-voltage side capacitor 4b, and the capacitor is appropriately arranged at an arbitrary place. It becomes possible.

The current sensor 5 is disposed so that the center axis of the current sensor 5 is substantially the same as the cylinder of the bushing 10 serving as an opening for insulating the main circuit conductor 20 inside the switch 1 attached to the electric energy sensor and the outer case 2. Rogowski coil 5a. The Rogowski coil 5a is a three-phase or two-phase main circuit conductor 20.
And is fixedly held by a holder (not shown) formed of an elastic body such as insulating rubber having a substantially concave cross section. Rogowski coil 5a
Is positioned in a state where it is arranged at an optimum position for detection.

Since the Rogowski coil 5a is wound around the bushing 10 in a state of being close to the inside of the outer box 2, the switch 1 with the electric energy sensor which is limited in space.
Is compactly stored in the same manner as the voltage sensor 4 described above. The current sensor 5 detects a current waveform (differential waveform) generated between the winding start and end terminals of the Rogowski coil 5a according to the magnitude of the magnetic field generated by the current of the main circuit conductor, The signal is sent to the signal processing unit 6.

The voltage waveform detected by the voltage sensor 4 and the current waveform detected by the current sensor 5 are subjected to signal processing by a signal processing section 6 and further processed by an arithmetic processing section 7 to calculate an electric energy. Power amount data for communication is generated. The communication interface circuit 8 outputs this power amount data to a data compiling device (not shown) via the optical fiber cable 11.

Next, these signal processing and arithmetic processing will be described. FIG. 2 shows a block diagram of the electric energy sensor of the electric energy sensor attached switch of the present invention. The power supply unit 12 is arranged inside the switch 1 attached to the electric energy sensor, for example, at a position of the bushing 10 facing the current sensor 5. Specifically, the power transformer 13 is connected to one of the main circuit conductors 20.
Connected between phase grounds or between phases. This power transformer 13
Obtains power by electromagnetic induction. The power supply unit 12 is connected to the secondary side of the power supply transformer 13. The power supply unit 12 includes a rectifier circuit 12a, a smoothing circuit 12b, a constant voltage power supply circuit 12c.
And supplies power to each unit of the signal processing unit 6 and the arithmetic processing unit 7. If a low-voltage distribution line is separately provided, the power supply unit 12 may obtain the power supply voltage by drawing in from the low-voltage distribution line instead of the power transformer 13.

The signal processing section 6 performs signal processing for converting the voltage waveform detected by the voltage sensor 4 into a voltage signal, and converting the current waveform detected by the current sensor 5 into a current signal. This processing will be described specifically. The voltage sensor 4 detects a voltage waveform of the capacitor divided in proportion to the voltage of the main circuit conductor 20, and sends this voltage waveform to the filter 6a. The filter 6a filters out a frequency equal to or more than の of the sampling frequency and outputs a voltage signal that is sufficiently suppressed in order to prevent generation of aliasing noise when the A / D converter 7a in the subsequent stage performs A / D conversion. I do.

On the other hand, a current waveform is generated between the winding start and end terminals of the Rogowski coil 5a, which is the current sensor 5, in proportion to the current of the main circuit conductor. Since the current waveform is a differentiated waveform, the current waveform is subjected to an integral waveform forming process / amplifying process via the integrating / amplifying circuit 6b.
c. The filter 6c filters out a frequency equal to or more than の of the sampling frequency and outputs a sufficiently suppressed current signal in order to prevent generation of aliasing noise when the A / D converter 7b in the subsequent stage performs A / D conversion. I do.

The arithmetic processing section 7 converts the voltage signal and the current signal output from the signal processing section 6 into digital signals, respectively, to calculate the electric energy. Specifically, the instantaneous value of the voltage signal of the analog value input to the A / D conversion unit 7a and the instantaneous value of the current signal of the analog value input to the A / D conversion unit 7b are changed at a cycle of, for example, 250 kHz. The signal is sampled, converted into digital voltage signals and current signals proportional to the values, and sent to the multiplying circuit 7c. Further, since the voltage and current pulse signals are counted, A /
The D converters 7a and 7b also send digital voltage signals and current signals directly to the frequency dividers 7h and 7i, respectively.

The multiplying circuit 7c includes A / D converters 7a and 7b
Are multiplied by the digital value voltage signal and the current signal, respectively, to calculate the instantaneous value electric energy signal, and send it to the integrating circuit 7d. The integrating circuit 7d integrates the instantaneous value electric energy signal over time and sends it to the pulse converting circuit 7e. The pulse conversion circuit 7e converts the input integration result into a pulse train having a frequency proportional to the amount of electric power, and sends it to the frequency dividing circuit 7f.

The frequency dividing circuit 7f divides the frequency of the pulse signal of the electric energy input from the pulse converting circuit 7e and sends it to the CPU 7g. The frequency dividers 7h and 7i are provided with an A / D converter 7
A voltage signal and a current signal of digital values output from a and 7b are frequency-divided and sent to CPU 7g.

The CPU 7g functions as a power amount calculating section and an effective value calculating section, and each of the frequency dividing circuits 7f, 7h, 7i.
And counts the pulse signals of the amount of electric power, current and voltage output from the controller, stores the counted values, averages the counted values at regular intervals, and sends the result to the communication interface circuit 8.

The communication interface circuit 8 includes a CPU 7
The power, voltage, and current values output from the CPU 7g based on the control from g are transmitted via a communication line such as the optical fiber cable 11. To the other end of the communication line, a data tabulation device (not shown) is connected, and various calculations and analyzes are performed by the data tabulation device.

The sequence of signal processing and signal processing has been described above. Other than the signal flow, this C
The PU 7g includes a sequence program for controlling the control circuit 7k, a communication procedure control program for the communication interface circuit 8, and the like, in addition to the above-described operation command program, power amount integration program, voltage and current pulse signal averaging program, and storage program. They are built in and control these.

Further, the control circuit 7k has the A /
It controls the operation of the arithmetic processing unit 7 including the D conversion units 7a and 7b, the multiplication circuit 7c, the integration circuit 7d, the pulse conversion circuit 7e, and the frequency division circuits 7f, 7h and 7i. These controls are performed by the control circuit 7k issuing an operation command based on the clock of the clock circuit 7j and the command of the CPU 7g.

As described above, the switch 1 attached to a power sensor according to the present embodiment is a power sensor having a voltage sensor 4 and a current sensor 5 corresponding to a VCT, a signal processing unit 6, an arithmetic processing unit 7, and a communication interface circuit 8. The unit measures the amount of power consumed by the customer and also manages the voltage and current. Various calculations are performed using these, and data can be obtained as data relating to the amount of power. In addition, the main circuit conductor 20 can be turned on and off by the switch unit.

Next, a brief description will be given of a case where the current sensor 5 is replaced with a Rogowski coil 5a and a through-type current transformer in which an electric wire is wound around a ring-shaped core (not shown) over the entire circumference is used. Adopting a through-type current transformer makes it easy to manufacture the current sensor itself and set the current transformer ratio. At that time, in the block diagram shown in FIG.
Instead, it is sufficient to provide an allowance such as connecting an analog amplifier circuit.

Further, if a split type current transformer in which the iron core is divided into two parts is adopted, the bushing 10 can be mounted even after the bushing 10 has been mounted, so that the assembling becomes easy. Further, the voltage sensor 4 and the current sensor 5 are not limited to the above-described sensors, and an optical voltage sensor using an optical conversion element that calculates and outputs a linear polarization plane rotation according to the voltage and current of the main circuit conductor 20 4 and the photocurrent sensor 5 may be employed.

In this embodiment, the switching contact, the voltage sensor, the current sensor, the signal processing unit, the arithmetic processing unit, and the communication interface circuit are provided as a switch with an electric energy sensor which is collectively incorporated in an outer case. However, if necessary, such as verification based on the Measurement Law, for example, while only the voltage sensor, current sensor and switch are built in the outer box,
The signal processing unit, the arithmetic processing unit, and the communication interface circuit may be separately housed in a case and separated, and may be installed in the vicinity of the switch to change the configuration as appropriate.

Further, in addition to the watt-hour meter, a measuring device such as a maximum demand watt-hour meter and a power factor meter is provided. And send and receive various signals such as operation signals to build a road survey online system,
Alternatively, it is possible to commercialize the business by automating meter reading and electricity bill collection.

[0042]

As described above, according to the present invention, a power sensor having a voltage sensor, a current sensor, a signal processing section, an arithmetic processing section, and a communication interface circuit which can be mounted compactly is provided by a customer and a power company. By attaching it integrally to the segment switch installed at the demarcation point, it contributes to space saving of the private high-voltage power receiving equipment, and eliminates the connection work with the bus associated with the conventional VCT installation,
It is possible to provide a switch attached to a power sensor that improves workability and reduces cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a schematic internal configuration of a switch attached to a power sensor according to the present invention.

FIG. 2 is a block diagram of a power sensor unit of the switch with power sensor according to the present invention.

FIG. 3 is an explanatory diagram of a high-voltage private power receiving facility.

FIG. 4 is a schematic structural view of a VCT with a partial cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch attached to an electric energy sensor 2 Outer case 3 Switching contact 4 Voltage sensor 4a High voltage side capacitor 4b Low voltage side capacitor 5 Current sensor 5a Rogowski coil 6 Signal processing part 6a Filter 6b Integral amplifier circuit 6c Filter 7 Arithmetic processing part 7a A / D converter 7b A / D converter 7c Multiplier 7d Integrator 7e Pulse converter 7f Divider 7g CPU 7h Divider 7i Divider 7j Clock circuit 7k Control circuit 8 Communication interface 9 Support insulator 10 Bushing 11 Light Fiber cable 12 Power supply section 12a Rectifier circuit 12b Smoothing circuit 12c Constant voltage power supply circuit 13 Power transformer 20 Main circuit conductor

Claims (7)

[Claims] 1. A switching contact installed in a distribution line for turning on and off a main circuit conductor, a voltage sensor for detecting a voltage waveform transformed from the main circuit conductor, and detecting a current waveform transformed from the main circuit conductor. A current sensor, a signal processing unit that converts a voltage waveform detected by the voltage sensor into a voltage signal, and a current waveform detected by the current sensor into a current signal, and a voltage output from the signal processing unit. An arithmetic processing unit that converts signals and current signals into digital signals to calculate various data related to the amount of power; and a communication interface circuit that sends out various data related to the amount of power calculated by the calculating unit to a communication line. A switch attached to an electric energy sensor. 2. The switch attached to an electric energy sensor according to claim 1, wherein the voltage sensor is formed by connecting a high-voltage capacitor and a low-voltage capacitor in series between a main circuit conductor and a ground. A switch attached to a power sensor, which detects a pressurized voltage waveform from a contact point between a high-side capacitor and a low-side capacitor. 3. The switch attached to an electric energy sensor according to claim 2, wherein the high-side capacitor is a high-side ceramic capacitor, the low-side capacitor is a low-side ceramic capacitor, and the high-side ceramic capacitor and the low-side ceramic capacitor are provided. A switch attached to a power sensor, which is directly connected and integrally formed with an insulating resin. 4. The switch attached to a power sensor according to claim 2, wherein the high-voltage capacitor is a high-voltage ceramic capacitor coated with an insulating resin, the low-voltage capacitor is a low-voltage film capacitor, and the high-voltage ceramic capacitor. And a switch attached to an electric energy sensor, wherein a film capacitor and a low voltage side film capacitor are connected in series. 5. The switch according to claim 1, wherein the current sensor is a Rogowski coil and is concentric with the main circuit conductor as an axis. Wherein the switch attached to the electric energy sensor detects a current waveform corresponding to a magnitude of a magnetic field generated by a current flowing through the main circuit conductor. 6. The switch attached to an electric energy sensor according to claim 1, wherein the current sensor is a current transformer in which an electric wire is wound around the entire circumference of a ring-shaped core, A switch attached to an electric energy sensor, wherein a main circuit conductor is provided so as to penetrate through a ring ring hole of the current transformer to detect a current waveform. 7. A switch attached to a power sensor according to claim 5, wherein the bushing has a cylindrical rotating body shape having a hole through which a main circuit conductor passes, and the current flows along an outer peripheral surface of the bushing. A holder for fixedly holding the sensor, wherein the holder is attached along the outer peripheral surface of the bushing to determine the Rogowski coil or the current transformer at an optimal position for measurement. A switch attached to an electric energy sensor, which is fixed and held.