JP6334457B2 - Current measurement system - Google Patents

Description

  The present invention relates to a current measurement system, and is particularly useful when applied to the detection of an abnormality in an electrical facility such as a detached house or a condominium as early as possible.

  Conventionally, in order to accurately grasp the energy consumption of electrical equipment in each home of a detached house or condominium and the energy consumed in the entire building, for example, by a current transformer (hereinafter referred to as CT) installed on a power line A device that enables current measurement and power supply has been proposed (see Patent Document 1).

  In the case of Patent Document 1, the measurement / power supply unit output is used for charging the capacitor of the energy storage unit in the standby state. Since the output is transmitted, it is possible to realize a self-powered sensor that operates without requiring an external power supply.

JP 2010-55356 A

  However, when the above-described sensor is used, the energy consumed at the measurement location can be accurately grasped, but it is insufficient to detect an abnormality in the electrical equipment.

  An object of the present invention is to provide a current measurement system capable of detecting an abnormality in an electrical facility at the earliest possible stage in view of the above-described prior art.

A first aspect of the present invention that achieves the above object includes a current transformer installed in a power line, a conversion unit that converts energy obtained from the current transformer into power supply energy, and the power supply energy to a capacitor. a storage section for storing the measurement and conversion unit for performing data processing of the current transformer in the measured current and the current waveform, with the by power for energy storage in the storage unit, the output of the measurement and conversion unit A current measuring system comprising: a transmitter unit that wirelessly transmits a sensor unit; and a receiver unit that includes a receiver unit that receives wireless communication from the sensor device, wherein the measurement / conversion unit A load resistor that converts a secondary current from the current transformer into a voltage, an effective value conversion circuit that converts the current from the load resistance into an effective value to obtain an analog value, and bypasses the effective value conversion circuit. You ; And a bypass circuit, wherein a waveform output state of outputting to the transmission section as the current waveform data current from the load resistor via the bypass circuit, the effective value of the current from the load resistance by the effective value converting circuit The current measurement system includes a switch that switches between a current output state that is converted into current data and output to the transmitter as current data .

  According to the current measurement system of this aspect, since the current waveform data of the CT installation location is transmitted from the transmitting unit to the receiving unit, the current waveform data can be obtained from the receiving unit of the receiving device. It is possible to grasp abnormalities in electrical equipment such as initial leakage of a refrigerator, poor contact of wiring that leads to leakage, and the like from distortion and the like. The current data can be obtained by analyzing the current waveform data.

A second aspect of the present invention, the measurement and conversion unit, the waveform and output state, the first aspect, wherein the current, wherein the current output state is configured to be switched alternately In the measurement system.

  In this aspect, the current waveform data and the current data are alternately transmitted to the transmitter, and both the current waveform data and the current data can be easily grasped.

According to a third aspect of the present invention, in the current measuring system according to the first or second aspect, the receiving device includes a memory for storing data received by the receiving unit.

  In this aspect, since the data received by the receiving unit is stored in the memory, the data can be extracted from the receiving device at an appropriate timing.

A fourth aspect of the present invention is the current measurement system according to any one of the first to third aspects, wherein the measurement / conversion unit has a variable resistance as the load resistance.

  In this aspect, variation in saturation characteristics of CT can be controlled by changing the load resistance.

A fifth aspect of the present invention, the measurement and conversion unit comprises a reference time generating means, first to 4, characterized in that for outputting a reference time signal from the reference time generating means to the transmitting unit The current measurement system according to any one of the aspects is provided.

  In this aspect, by outputting the reference time signal, current waveform data and the like can be received together with the reference time signal, so that data analysis can be performed relatively easily.

According to a sixth aspect of the present invention, the transmitter uses the storage state in which the storage unit stores the power source energy in the capacitor and the power source energy stored in the capacitor, so that the transmission unit outputs the output of the measurement / conversion unit. Switching means for switching between a transmission state and a wireless transmission state, wherein the switching means is switched from the storage state to the transmission state when a predetermined amount of power source energy stored in the capacitor is stored. The current measurement system according to any one of the first to fifth aspects is characterized.

  In this aspect, when the power source energy is stored in the capacitor, the transmission unit switches to the transmission state and transmits current waveform data and the like.

According to a seventh aspect of the present invention, the measurement / conversion unit includes a non-volatile memory that stores an output of the measurement / conversion unit during the accumulation state, and the transmission unit is in the transmission state period. The current measurement system according to the sixth aspect is characterized in that the data stored in the nonvolatile memory is transmitted.

  In this mode, current waveform data and the like during a period in which the power source energy is accumulated in the capacitor are stored in the nonvolatile memory and transmitted when the transmission state is established.

It is a block diagram of the electric current measurement system which concerns on Embodiment 1 of this invention. It is a block diagram of the receiver of Embodiment 1 of this invention. It is a block diagram of the electric current measurement system which concerns on Embodiment 2 of this invention. It is a block diagram of the electric current measurement system which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same number is attached to the same part, and duplicate explanation is omitted.

(Embodiment 1)
FIG. 1 is a block diagram showing a current measurement system according to Embodiment 1 of the present invention, and FIG. 2 is a block diagram of a receiving apparatus.
As shown in FIG. 1, the current measurement system of the present embodiment includes, for example, a sensor device 1 installed on a switchboard and a receiving device 2 installed at an appropriate place.

  The sensor device 1 includes a sensor main body 10 and a CT (current transformer) 11 arranged so as to pass through a power line in the switchboard. The sensor main body 10 converts energy obtained from the CT 11 into power supply energy. The conversion unit 12, the storage unit 13 that stores the power source energy converted by the conversion unit 12, the measurement / conversion unit 14 that is connected to the secondary side of the CT 11 and detects current waveform data through the CT 11, and the measurement A transmission unit 15 connected to the conversion unit 14 is provided. Here, the conversion unit 12 and the storage unit 13, the measurement / conversion unit 14, and the transmission unit 15 are connected to the switching circuit 16 and can be switched to each other.

  A power supply monitoring circuit 17 is connected to the storage unit 13, and when the storage unit 13 stores predetermined power supply energy, the switching circuit 16 is controlled to switch from the conversion unit 12 and the storage unit 13 to the measurement / conversion unit 14. To control. A regulator 18 is connected to the power supply monitoring circuit 17 so that the power supply energy stored in the storage unit 13 is supplied to the measurement / conversion unit 14 and the transmission unit 15 via the regulator 18.

Here, although an example of the specific structure of the conversion part 12, the accumulation | storage part 13, and the measurement and conversion part 14 is demonstrated, it cannot be overemphasized that it is not limited to this.
The conversion unit 12 includes a diode bridge 12A that full-wave rectifies the alternating current from the CT 11, and a smoothing circuit 21B that smoothes the full-wave rectified wave that is full-wave rectified by the diode bridge 12A into a direct current. The storage unit 13 includes a supercapacitor 13A that stores electricity, and a supercapacitor controller 13B that controls electric charge of the supercapacitor 13A. The measurement / conversion unit 14 includes a load resistor 14A that converts the secondary current from the CT 11 into a voltage, and the load resistor 14A is connected to the effective value conversion circuit 14C via the switch 14B. The effective value conversion circuit 14 </ b> C is a circuit that converts the current from the load resistor 14 </ b> A into an effective value to obtain an analog value, and outputs the output to the transmitter 15. The effective value conversion circuit 14C may be an A / D conversion circuit or the like as long as the sampling frequency is high.

  The switch 14B bypasses the effective value conversion circuit 14C and directly connects the load resistor 14A and the transmission unit 15, and connects the load resistance 14A and the transmission unit 15 via the effective value conversion circuit 14C. Is to switch. Here, when the effective value conversion circuit 14C is bypassed and switched to a circuit in which the load resistor 14A and the transmission unit 15 are directly connected, current waveform data is output to the transmission unit 15, and the effective value conversion circuit When the circuit is switched to a circuit connecting the load resistor 14 </ b> A and the transmitter 15 via 14 </ b> C, current data is output to the transmitter 15. The switch 14B can be switched by an external command signal or the like, but in this embodiment, the switch 14B is switched via a physical switch (not shown) provided in the sensor body 10. It is like that.

  On the other hand, as shown in FIG. 2, the receiving device 2 includes a receiving unit 21 that receives data transmitted from the transmitting unit 15, a CPU 22 that receives data received by the receiving unit 21, and a memory 23 that is connected to the CPU 22. The wireless module 24 and the LAN module 25 are provided. The receiving device 2 receives data transmitted from the transmitting unit 15 of the sensor device 1 via the receiving unit 21 and outputs the received data to the personal computer 3 or the like via the wireless module 24 or the LAN module 25. It is a repeater.

  In such a current measurement system, current waveform data and current data can be measured by the following procedure.

  The sensor device 1 attached to a power line such as a switchboard via the CT 11 is first in an accumulation state in which energy obtained from the CT 11 is accumulated as power source energy, and the power source energy converted by the conversion unit 12 is stored in the supermarket of the accumulation unit 13. Accumulated in capacitor 13A. The power supply monitoring circuit 17 monitors the accumulation state in the supercapacitor 13A, outputs a trigger signal when the accumulation exceeds a predetermined threshold, switches the switching circuit 16 from the conversion unit 12 to the measurement / conversion unit 14, and transmits the transmission state. It becomes.

  In the transmission state, power source energy is supplied to the transmission unit 15 via the regulator 18 to wake up the transmission unit 15. Further, the power source energy from the regulator 18 is supplied to the measurement / conversion unit 14, and data obtained from the secondary current of the CT 11 is output to the transmission unit 15, and the transmission unit 15 transmits the input data.

  Data transmitted from the transmission unit 15 is received by the reception unit 21 of the reception device 2 and stored in the memory 23 via the CPU 22. When the personal computer 3 is connected via the LAN module 25, the data received by the receiving unit 21 is also output to the personal computer 3.

  In the present embodiment, the data transmitted from the transmission unit 15 is either current waveform data or current data depending on the switching state of the switch 14B of the measurement / conversion unit 14. When data is transmitted via the effective value conversion circuit 14C, it is current data, and when data is transmitted bypassing the effective value conversion circuit 14C, it is current waveform data.

  When the current data is transmitted, a case where a complete leakage is detected in addition to power consumption is detected. On the other hand, when current waveform data is being transmitted, it can be determined whether the current waveform is a normal waveform or a waveform that is distorted. For example, an abnormality that may lead to future leakage in a refrigerator or the like has occurred. In this case, it can be detected as a waveform distortion, and measures such as prevention of electric leakage, which has been impossible in the past, can be realized.

  As a usage method, normally, current data is output. For example, after an earthquake occurs, the current waveform data is switched to be output, and whether the current waveform data is distorted or the like is detected.

  Further, since the current waveform data can be easily converted into current data if it is taken into the personal computer 3, the current waveform data may always be output.

  In this embodiment, the switch 14B is switched by a physical switch. However, the switch 14B may be switched by control from the personal computer 3 or may be switched at regular intervals by providing a CPU or the like. You may be made to be.

  Since the receiving device 2 includes the memory 23, the data received by the receiving unit 21 is stored in the memory 23. Therefore, the data can be extracted by connecting the personal computer 3 as necessary. In an environment where 3 is connected, the memory 23 is not necessarily provided.

  Note that the standard for wirelessly connecting the transmission unit 15 and the reception unit 21 is not particularly limited, and is not particularly limited, such as low power wireless, wireless LAN, WiFi, Bluetooth, etc. .

  Further, the standard of the wireless module 24 of the receiving device 2 is not particularly limited as long as it is a wireless LAN, WiFi, Bluetooth, or the like.

(Embodiment 2)
FIG. 3 is a block diagram showing a current measurement system according to Embodiment 2 of the present invention.
The current measurement system shown in FIG. 3 is the same as that of the first embodiment except that the measurement / conversion unit 14 includes a CPU 14D and a GPS module 19 that outputs a reference time signal to the CPU 14D is provided in the sensor body 10. Therefore, the same reference numerals are assigned to the same components, and duplicate descriptions are omitted.

  In the present embodiment, a circuit that bypasses the effective value conversion circuit 14C and directly connects the load resistor 14A and the transmission unit 15, and a circuit that connects the load resistance 14A and the transmission unit 15 via the effective value conversion circuit 14C. The switch 14B, which is a switching means for switching between and, can be controlled via the CPU 14D, and the switch 14B is periodically switched every predetermined period, or the switch 14B is switched based on the control signal received via the transmitter 15. Can be.

In the present embodiment, the reference time signal received by the GPS module 19 is transmitted from the transmitter 15 together with the current waveform data and current data. Thereby, since the receiving device 2 and the personal computer 3 (see FIG. 2) can receive the current waveform data and the current data together with the reference time signal, more accurate analysis can be performed.
The means for acquiring the reference time signal is not limited to the GPS module 19, and may be a module that receives a standard radio wave or a built-in clock, for example.

(Embodiment 3)
FIG. 4 is a block diagram showing a current measurement system according to Embodiment 3 of the present invention.
The current measurement system shown in FIG. 4 is the same as that of the second embodiment except that the measurement / conversion unit 14 includes a nonvolatile memory 14E. Omitted.

  In the present embodiment, the measurement / conversion unit 14 operates in the accumulation state, the measured data is stored in the memory 14E, and after switching to the transmission state, the data stored in the memory 14E is stored. This is transmitted from the transmitter 15. In the first and second embodiments described above, current waveform data and current data during the accumulation period cannot be acquired. However, in this embodiment, data during the accumulation state can also be acquired.

(Other embodiments)
Although the current sensor is formed of a current transformer in the above embodiment, it is not necessarily limited to this. Further, the power source means need not be limited to a current transformer, and as the power source means, a power source by an electromagnetic induction method, an environmental magnetic field power generation method, or a solar energy method may be provided.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in the electric power industry that performs low-voltage power transmission and the industrial field that performs maintenance and inspection of this type of low-voltage power transmission line.

1 Sensor device 2 Receiver 10 Sensor body 11 CT
DESCRIPTION OF SYMBOLS 12 Conversion part 13 Accumulation part 14 Measurement / conversion part 15 Transmission part 16 Switching circuit 17 Power supply monitoring circuit 18 Regulator 19 GPS module 21 Reception part

Claims (7)

A current transformer installed in the power line;
A converter that converts energy obtained from the current transformer into energy for power supply;
An accumulator that accumulates the energy for power supply in a capacitor;
And measurement and conversion unit for performing data processing of the measured current and the current waveform in the current transformer,
A transmitter that wirelessly transmits the output of the measurement / conversion unit using the power source energy stored in the storage unit;
A sensor device comprising:
A current measuring system including a receiving device including a receiving unit that receives wireless communication from the sensor device;
The measurement / conversion unit includes a load resistor that converts a secondary current from the current transformer into a voltage, an effective value conversion circuit that converts the current from the load resistor into an effective value to obtain an analog value, and the effective value A bypass circuit that bypasses the value conversion circuit, a waveform output state in which the current from the load resistor is output as current waveform data to the transmitter through the bypass circuit, and the current from the load resistor is the effective A current measurement system comprising: a switch that switches between a current output state that is converted into an effective value by a value conversion circuit and is output as current data to the transmitter . The measurement and conversion unit, the current measuring system according to claim 1, wherein the said waveform output state, said current output state is configured to be alternately switched. The receiving apparatus, the current measuring system according to claim 1 or 2, wherein it comprises a memory for storing data received by the receiving unit. The measurement and conversion unit, the current measuring system of any one of claims 1 to 3, wherein the load resistor is a variable resistor. The measurement and conversion unit, reference comprises a time generating means, any one claim of current claims 1-4 for the reference time signal from the reference time generating means and outputting the transmission unit Measuring system. An accumulation state in which the storage unit accumulates the power source energy in the capacitor, and a transmission state in which the transmission unit wirelessly transmits the output of the measurement / conversion unit using the power source energy stored in the capacitor. comprising a switching means for switching, said switching means of claim 1 to 5, characterized in that the power for the energy stored in the capacitor is switched from the storage state when it is a predetermined amount stored in the calling state The current measurement system according to any one of the above. The measurement / conversion unit includes a non-volatile memory that stores the output of the measurement / conversion unit during the accumulation state, and the transmission unit stores data stored in the non-volatile memory during the transmission state The current measurement system according to claim 6, wherein: