JP2022132608A - Power supply device and power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology with which it is possible to improve the accuracy of measuring a current flowing in an electric wire while supplying electric power obtained from a current transformer to a load.

SOLUTION: Provided is a power supply device comprising: a core provided so as to enclose an electric wire; a coil wound around the core, for causing an induction current to be generated by electromagnetic induction on the basis of a change of magnetic flux generated in the core by a current flowing in the electric wire; a power supply unit connected to the coil, for supplying electric power to a prescribed load on the basis of induction current generated in the coil; a measurement unit connected between the coil and the load, for measuring a load current flowing on the load side and a load voltage applied to the load side; and a current calculation unit connected to the measurement unit, for calculating a load resistance on the load side on the basis of load current and load voltage measured by the measurement unit, and calculating a current on the basis of an induced voltage occurring to the coil and the load resistance.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to power supply devices and power supply systems.

A current transformer unit is sometimes attached to a transmission/distribution line (hereinafter abbreviated as "electric wire"). By using the current transformer unit, it is possible to obtain a predetermined electric power and measure the current flowing through the electric wire by electromagnetic induction from the magnetic field generated around the electric wire (for example, Patent Document 1).

JP-A-6-58960

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique capable of improving the accuracy of measuring the current flowing through a wire while supplying power obtained from a current transformer to a load.

According to one aspect of the invention,
a core provided in an annular shape so as to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
connected to the measuring unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and calculating the current based on the induced voltage generated in the coil and the load resistance a current calculation unit for
A power supply is provided comprising:

According to another aspect of the invention,
A power system comprising a power supply and a monitoring device,
The power supply device
a core provided to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
a transmission unit connected to the power supply unit as one of the loads, and transmitting information related to the load current and the load voltage measured by the measurement unit to the outside;
has
The monitoring device
receiving information about the load current and the load voltage from the transmitting unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and generating an induced voltage in the coil; and a current calculator that calculates the current based on the load resistance.

According to yet another aspect of the invention,
a core provided in an annular shape so as to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a current calculation unit connected to the second coil-side measurement unit and calculating the current based on the induced voltage measured by the second coil-side measurement unit;
A power supply is provided comprising:

According to yet another aspect of the invention,
A power system comprising a power supply and a monitoring device,
The power supply device
a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a transmission unit connected to the power supply unit as one of the loads and transmitting to the outside information related to the induced voltage measured by the second coil side measurement unit;
has
The monitoring device
A power supply system is provided that includes a current calculator that receives information about the induced voltage from the transmitter and calculates the current based on the induced voltage measured by the second coil-side measuring unit.

ADVANTAGE OF THE INVENTION According to this invention, the measurement accuracy of the electric current which flows into an electric wire can be improved, supplying the electric power obtained from a current transformer part to load.

1 is a schematic configuration diagram showing a power supply device according to a first embodiment of the present invention; FIG. FIG. 4 is a schematic configuration diagram showing a power supply device according to modification 1-1 of the first embodiment of the present invention; FIG. 10 is a schematic diagram showing magnetization characteristics of a core in modification 1-3; FIG. 10 is a diagram showing waveforms of induced currents generated in the coil of modification 1-3; FIG. 10 is a diagram showing waveforms of induced currents generated in the coil of modification 1-3; FIG. 5 is a schematic configuration diagram showing a power supply device according to a second embodiment of the present invention; FIG. 11 is a schematic configuration diagram showing a power supply device according to modification 2-1 of the second embodiment of the present invention;

<Knowledge acquired by the inventor>
First, the knowledge obtained by the inventor will be described.

In recent years, in a power supply device that uses a current transformer section and obtains a predetermined amount of power through electromagnetic induction from a magnetic field generated around an electric wire, it has become possible to achieve both obtaining the electric power and measuring the current flowing through the electric wire. It has been demanded. Methods for achieving both of these are classified into (i) the case where two current transformer sections are provided and (ii) the case where only one current transformer section is provided.

As a result of intensive studies, the inventors have found that each of the cases (i) and (ii) may have unique problems.

(i) When Two Current Transformer Sections are Provided When two current transformer sections are provided, one of the two current transformer sections is used as a power supply for obtaining electric power, and the other is used to measure the electric current of the electric wire. Used for measurement.

However, in this case, the number of members has increased by the two current transformer sections. In addition, the size of the power supply device is increased by the two current transformer portions.

Also, in this case, each of the two current transformer sections is split in half along the axial direction so that it can be attached to an existing electric wire. Therefore, when attaching the two current transformer sections to the electric wire, it is necessary to align the axes of the halved core halves and join them together.

However, due to the mechanism of the power supply device, it was difficult to connect the core halves of the two current transformer sections. In particular, it has been very difficult to adjust the positions of the joint surfaces of the core halves so that the core halves of both of the two current transformer sections are joined together at the same time.

As a result, when two current transformer units are provided, the manufacturing cost tends to increase.

(ii) When Only One Current Transformer Section is Provided When only one current transformer section is provided, a load that executes a predetermined process is applied to the coil of the current transformer section via a power supply section having a rectifying function, for example. Connected. The measurement unit is, for example, connected between the coil and the load and configured to measure the induced voltage generated in the coil. With such a configuration, the current flowing through the wire can be calculated based on the induced voltage measured by the measurement unit.

However, in this case, while the load is executing a predetermined process, the resistance of the load (hereinafter also referred to as load resistance) may fluctuate according to the processing status of the load. If the load resistance fluctuates, the electric current in the wire cannot be accurately calculated based on the induced voltage measured by the measuring unit. As a result, when only one current transformer section is provided, there is a possibility that the measurement accuracy of the current flowing through the electric wire is lowered.

Therefore, there is a demand for a technique capable of improving the measurement accuracy of the current flowing through the electric wire while supplying the power obtained from the current transformer to the load.

The present invention is based on the above findings (i) and (ii) found by the inventors.

<First embodiment of the present invention>
(1) Power Supply Device A power supply device 10 according to the first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram showing a power supply device according to this embodiment.

As shown in FIG. 1, the power supply device 10 of this embodiment is configured to generate a predetermined power using electromagnetic induction from a wire 100 . In this embodiment, a case where the power supply device 10 is applied as, for example, a wire physical quantity measuring device will be described.

The power supply device 10 of this embodiment includes, for example, a current transformer section 200, a power supply section 300, a measurement section 410, a control section 500, a radio section 620, and a physical quantity measurement section 640. Note that the term “current transformer” may be abbreviated as “CT” below.

(Electrical wire)
In this embodiment, the electric wire 100 is configured as, for example, a so-called overhead transmission line. Specifically, the electric wire 100 is, for example, a steel core aluminum stranded wire (ACSR). In this case, the electric wire 100 is provided, for example, by twisting a plurality of strands so as to cover the central portion that bears the tension during overhead wiring and a plurality of strands so as to cover the outer periphery of the central portion, and is configured as a conductor through which current flows during power transmission. and a stranded wire layer. The wire constituting the central portion is, for example, an aluminum covered steel wire (AC wire). The wires forming the twisted wire layer are made of, for example, aluminum (Al) or an Al alloy.

(current transformer)
The CT section 200 has, for example, a core 220 and a coil 240 . The core 220 is annularly provided so as to surround the outer periphery of the electric wire 100 . Also, the core 220 is made of a magnetic material. The magnetic material forming core 220 is, for example, ferrite. Coil 240 is wound around at least a portion of core 220 . With such a configuration, an induced current can be generated in the coil 240 by electromagnetic induction based on a change in the magnetic flux generated in the core 220 around the electric wire 100 by the current flowing through the electric wire 100 .

Hereinafter, the current flowing through the wire ₁₀₀ in the CT section 200 is defined as I1, the induced current generated in the coil 240 is defined as _I2 , and the induced voltage generated in the coil ₂₄₀ is defined as E2.

In this embodiment, for example, only one CT unit 200 is provided. That is, the CT section 200 serves both as a power supply and as a current measurement.

Further, the core 220 is, for example, split in half along the axial direction, and has a first core split portion 222 and a second core split portion 224 . This makes it possible to easily attach the CT section 200 to the existing electric wire 100 .

Although FIG. 1 shows that the coil 240 is wound only around the first core half portion 222, the coil 240 is wound around the first core half portion 222 and the second core portion 222 via a predetermined lead wire. It may be wound over half 224 .

(Power supply part)
The power supply unit 300 is, for example, connected to the coil 240 of the CT unit 200 and configured to supply electric power to a predetermined load, which will be described later, based on the induced current generated in the coil 240 . The "load" here means a functional unit that executes a predetermined process, and in this embodiment, the control unit 500, the radio unit 620, and the physical quantity measurement unit 640, which will be described later, correspond to the load.

In this embodiment, the power supply unit 300 has, for example, a protection unit 320, a rectification unit 340, and a waveform shaping unit 360.

The protector 320 is configured to protect the load from surge currents, for example. That is, for example, when a surge voltage is applied to the power supply unit 300, the protection unit 320 is configured to release the surge current so that the surge current does not flow to the load. Specifically, the protection unit 320 has, for example, a Zener diode (not shown).

The rectifying section 340 is configured, for example, to rectify an AC induced current generated in the coil 240 into a DC current. Specifically, the rectifying section 340 has, for example, four bridge-connected diodes (not shown).

The waveform shaping section 360 is provided, for example, closer to the load than the rectifying section 340, and is configured to shape the waveform of the induced current _I2 rectified to DC into a current waveform (constant current waveform) suitable for the load. there is Specifically, the waveform shaping section 360 has, for example, at least a capacitor (not shown) connected in parallel with the rectifying section 340 .

In this embodiment, the protection unit 320, the rectification unit 340, and the waveform shaping unit 360 are arranged in this order (in parallel) from the coil 240 toward the load side, for example.

(Measuring part)
The measuring unit 410 is, for example, connected between the coil 240 and the load, and configured to measure the load current flowing to the load side and the load voltage applied to the load side. The load current and load voltage measured by measuring section 410 are used to obtain the load resistance on the load side.

The “load side” here means a portion connected to the load side rather than the measuring unit 410, that is, at least a part of the power supply unit 300 between the measuring unit 410 and the load, and the load. , means the part containing Further, the “load current” flowing to the load side means, for example, a combined current flowing to at least a part of the power supply section 300 and the load, and the load voltage applied to the load side means, for example, the power supply section 300 and the composite voltage (AC voltage before rectification) applied to at least a part of and the load. Hereinafter, let _IL be the load current, _VL be the load voltage, and R be the load resistance.

In this embodiment, the measuring section 410 is connected at least closer to the coil 240 than the rectifying section 340, for example. As a result, the load resistance R including the parasitic resistance components of the rectifying section 340 and the waveform shaping section 360 can be obtained.

Here, the measurement unit 410 is connected between the coil 240 and the protection unit 320, for example. Thereby, the load resistance R as a combined resistance including the entire power supply section 300 and the load can be measured. It should be noted that since current does not flow through the protection unit 320 during normal operation, the protection unit 320 can be ignored in the calculation of the load resistance R even if the measurement unit 410 is connected between the coil 240 and the protection unit 320. .

In this embodiment, the measuring section 410 has, for example, a voltage measuring section 412 and a current measuring section 414 .

The voltage measurement unit 412 is connected in parallel with the coil 240, for example. Accordingly, the voltage measurement unit 412 can measure the induced voltage E2 generated in the coil 240. _FIG .

In this embodiment, the voltage measuring section 412 is connected closer to the coil 240 than the current measuring section 414, for example. As a result, the induced voltage E2 generated in the coil ₂₄₀ can be accurately measured without depending on the shunt resistor 414r of the current measuring section 414, which will be described later.

Current measuring section 414 is connected in series with coil 240 , for example, between voltage measuring section 412 and power supply section 300 . The current measurement unit 414 has, for example, a shunt resistor 414r and a voltmeter 414v. A shunt resistor 414 r is connected in series with the coil 240 . The voltmeter 414v is connected in parallel with the shunt resistor 414r. Assuming that the resistance of the shunt resistor 414r is r and the voltage measured by the voltmeter _414v is _VA , the load current IL can be obtained by IL _{= VA} /r. Since the internal resistance of the voltage measuring section 412 can be considered infinite, the load current I _L can be considered equal to the induced current I ₂ generated in the coil 240 .

In this embodiment, the load voltage V _L is obtained by V _L =E ₂ -rI _L based on the induced voltage E ₂ measured by the voltage measurement unit 412 and the load current I _L measured by the current measurement unit 414. be able to. That is, in the present embodiment, the load voltage _VL is indirectly obtained ₍ indirectly measured) based on the induced voltage E2 measured by the voltage measuring section 412 .

(control part)
The control unit 500 is, for example, connected to the power supply unit 300 as one of the loads, and is configured to control loads other than the control unit 500 with power from the power supply unit 300 .

The controller 500 has, for example, a current calculator 520 . The current calculator 520 is, for example, connected to the measuring unit 410 and configured to calculate the current I1 flowing through the electric wire ₁₀₀ . Specifically, the current calculator 520 calculates the current _I1 according to the following procedure, for example.

First, based on the load current _{IL measured by the measuring unit 410 and the load voltage VL indirectly} obtained from the induced voltage E2 measured by the measuring unit 410, the load resistance R on the load _side is set to R= It is calculated by V _L /I _L. After calculating the load resistance R, the current I1 flowing through the electric wire ₁₀₀ can be calculated based on the induced voltage E2 generated in the coil ₂₄₀ and the load resistance R by the following equation (1).
I1= _E2NK /(R+r) ( ₁ )
where N is the number of turns of coil 240 and K is the coupling coefficient.

Thus, even if the load resistance R fluctuates, the current I1 flowing through the electric wire ₁₀₀ can be calculated with high accuracy by calculating the fluctuating load resistance R. FIG.

In this embodiment, the control unit 500 is configured by, for example, an MCU (Micro Controller Unit) (not shown). Specifically, the MCU constituting the control unit 500 includes, for example, a processor (not shown), a memory (not shown), one or more timers (not shown), and an I/O port (not shown). ,have. The processor is configured to control the load and function as the current calculator 520 by executing a predetermined program stored in the memory. The memory stores the above-described program and information (various data) related to the physical quantity of the electric wire 100 measured by the physical quantity measuring section 640, which will be described later. The timer serves as a reference for the measurement cycle of the physical quantity measurement unit 640 and the transmission/reception cycle of the radio unit 620 . A power supply unit 300 and a load are connected to the I/O port. All the parts that constitute these MCUs are incorporated in one integrated circuit. Note that the control unit 500 may have an external memory such as an FROM (Flash Read-Only Memory) in addition to the memory of the MCU.

(Physical quantity measurement unit)
The physical quantity measurement unit 640 is, for example, connected to the power supply unit 300 as one of the loads, and is configured to measure the physical quantity of the electric wire 100 using power supplied from the power supply unit 300 . The physical quantity related to the electric wire 100 here is, for example, the temperature of the electric wire 100, the vibration of the electric wire 100, the slackness of the electric wire 100, and the like.

The physical quantity measuring section 640 is, for example, a temperature sensor section (not shown). Thereby, the temperature of the electric wire 100 can be measured. The temperature sensor section has, for example, a thermocouple that outputs a voltage corresponding to temperature. The temperature sensor section may have a thermistor whose resistance changes according to temperature.

Also, the physical quantity measurement unit 640 is, for example, a vibration sensor unit (not shown). Thereby, the vibration of the electric wire 100 can be measured.

Also, the physical quantity measuring unit 640 is, for example, a GPS (Global Positioning System) (not shown). Thereby, the vibration of the electric wire 100, the slackness of the electric wire 100, etc. can be measured.

The physical quantity measuring section 640 has, for example, at least one of the above temperature sensor section, vibration sensor section, and GPS. Note that the measurement unit 410 that measures the current I1 flowing through the electric wire 100 may also be considered as _one of the physical quantity measurement units 640 .

Also, the physical quantity measurement unit 640 is connected to the control unit 500, for example. For example, the control unit 500 controls the physical quantity measuring unit 640 to measure the physical quantity of the electric wire 100 (at a predetermined timing).

(Radio section (transmitting section, transmitting/receiving section))
The wireless unit 620 is, for example, connected to the power supply unit 300 as one of the loads, and configured to wirelessly transmit and receive predetermined information.

The wireless unit 620 is, for example, connected at least to the control unit 500 and configured to wirelessly transmit various data measured by the physical quantity measuring unit 640 to the outside. Radio section 620 may be configured to be connected to physical quantity measuring section 640 and directly receive various data measured by physical quantity measuring section 640, for example. The control unit 500 controls transmission and reception of various data by the wireless unit 620, for example.

In addition, in this embodiment, the wireless unit 620 is configured to transmit various data by so-called multi-hop wireless communication (bucket brigade system), for example. Specifically, for example, in a power transmission facility monitoring system (power transmission system) having a plurality of power supply devices 10 as wire physical quantity measuring devices, a plurality of wire physical quantity measuring devices are measured along the axial direction of the wire 100 at predetermined intervals. placed. The wireless unit 620 of a predetermined wire physical quantity measuring device among the plurality of wire physical quantity measuring devices, for example, first receives various data from the adjacent front-stage (upstream) wire physical quantity measuring device. When the wireless unit 620 of a predetermined wire physical quantity measuring device receives various data from the preceding physical wire physical quantity measuring device, it aggregates the various data of the preceding physical wire physical quantity measuring device and its own various data. After collecting various data in the radio unit 620 of the predetermined wire physical quantity measuring device, the latter stage (downstream) wire physical quantity measuring device adjacent to the opposite side of the preceding stage physical wire physical quantity measuring device with the predetermined wire physical quantity measuring device interposed therebetween. Send various aggregated data to Such aggregation and transmission of various data are sequentially repeated in each of the plurality of wire physical quantity measuring devices. When the aggregated various data are transmitted to the last-stage wire physical quantity measuring device, the last-stage wire physical quantity measuring device transmits the aggregated various data to, for example, a data aggregation transmission device (not shown). The data aggregation transmission device transmits the aggregated various data wirelessly or by wire, for example, to an electric power company serving as a power supply source that supplies power to the electric wire 100 . The electric power company controls the power transmission capacity to the electric wire 100 based on various data. By transmitting various data by multi-hop wireless communication in this way, the power required for the wireless unit 620 of each physical wire physical quantity measuring device is reduced, and the transmission distance of the multiple physical wire physical quantity measuring devices as a whole is lengthened. be able to.

Further, in the present embodiment, the radio section 620 is adapted to, for example, repeatedly transmit various data at predetermined intervals. The cycle in which the radio unit 620 transmits various data is, for example, 3 minutes. Accordingly, an electric power company that supplies electric power to the electric wire 100 can grasp the temperature of the electric wire 100 and the electric current of the electric wire 100 in real time based on various data transmitted from the electric wire physical quantity measuring device. By grasping the temperature of the electric wire 100 and the current of the electric wire 100 in real time, the power transmission capacity to the electric wire 100 can be controlled based on the temperature of the electric wire 100 and the electric current of the electric wire 100 in the real time. As a result, it becomes possible to realize efficient power transmission to the electric wire 100 .

(2) Effects According to the Present Embodiment According to the present embodiment, one or more of the following effects can be obtained.

(a) In the power supply device 10 of the present embodiment, the measurement unit 410 measures the load current _{IL flowing to the load side and the load voltage VL applied} to the load side. Current calculation unit 520 calculates load resistance R on the load side based on load current _IL and load voltage _VL measured by measurement unit 410 . Accordingly, even if the load resistance R fluctuates according to the processing status of the load while the load is executing a predetermined process, the fluctuating load resistance R can be calculated. By calculating the varying load resistance R, it is possible to accurately calculate the current I1 flowing through the electric wire ₁₀₀ based on the induced voltage E2 generated in the coil ₂₄₀ and the load resistance R. As a result, it is possible to improve the measurement accuracy of the current I1 flowing through the wire ₁₀₀ while supplying the power obtained from the CT section 200 to the load.

(b) Only one CT unit 200 can be provided by using the CT unit 200 for both power supply and measurement. As a result, the number of members related to the CT section 200 can be reduced, and an increase in the size of the power supply device 10 can be suppressed.

Also, by using only one CT unit 200, the mechanism of the power supply device 10 can be simplified. Here, in the case where two CT sections are provided, it is difficult to connect the core half sections of the two CT sections due to the mechanism of the power supply device, as described above. On the other hand, in the present embodiment, by using only one CT section 200, the first core half-section 222 and the second core half-section 224 can be easily connected to each other. The mechanism can be simplified.

As a result, in this embodiment, it is possible to suppress an increase in the manufacturing cost of the power supply device 10 .

(c) By _obtaining the load resistance R based on the load current IL and the load voltage _VL measured by the measurement unit 410, the change state of the load resistance R can be grasped. This makes it possible to indirectly grasp the processing status of the load. Furthermore, it can also be utilized for diagnosis when the power supply device 10 malfunctions.

(d) The measuring section 410 is connected at least closer to the coil 240 than the rectifying section 340 . Thereby, the load resistance R including not only the resistance component of the load that executes the predetermined processing but also the parasitic resistance component of the rectifying section 340 and the waveform shaping section 360 can be obtained.
That is, it is possible to appropriately obtain the load resistance R obtained by synthesizing all the resistance components that may fluctuate. As a result, the measurement accuracy of the current I1 flowing through the electric wire ₁₀₀ can be stably improved.

(3) Modifications of First Embodiment The first embodiment described above can be modified as in the following modifications, if necessary. Hereinafter, only elements different from the above-described first embodiment will be described, and elements that are substantially the same as those described in the above-described first embodiment will be given the same reference numerals, and descriptions thereof will be omitted.

(3-1) Modification 1-1 of the first embodiment
A power supply device 10 according to Modification 1-1 of the present embodiment will be described with reference to FIG. FIG. 2 is a schematic configuration diagram showing a power supply device according to Modification 1-1 of the present embodiment.

In the power supply device 10 of Modified Example 1-1 of this embodiment, the configuration of the measurement section 410 is different from that of the above embodiment.

(Measuring part)
In this modification, the voltage measurement unit 412 is connected in parallel to the power supply unit 300 on the load side of the current measurement unit 414, for example. Thereby, the load voltage _VL applied to the load side can be measured with high accuracy.

In this modification, the current measuring section 414 is connected in series with the coil 240 between the coil 240 and the voltage measuring section 412, for example. Thereby, the current measurement unit 414 can measure the induced current _I2 generated in the coil 240 . Also in this modification, the internal resistance of the voltage measuring unit 412 can be considered infinite, so the load current IL can be considered equal to the induced current _I2 generated in the coil ₂₄₀ .

In this modification, the induced voltage E2 generated in the coil ₂₄₀ is E2 _{= rI2+VL based on} the load voltage _VL measured by the voltage measuring unit 412 and the load current IL measured by the current measuring unit 414. can be obtained by That is, in the present embodiment, the induced voltage E2 generated in the coil ₂₄₀ is indirectly obtained based on the load voltage _VL measured by the voltage measuring section 412. FIG.

(current calculator)
In the current calculation unit 520 of this modification, first, based on the load current IL and the load voltage _VL measured by the measurement unit 410, the load resistance R on the load side is calculated by R _{= VL} / _IL . After calculating the load resistance R, based _on the induced voltage E2 indirectly obtained from the load voltage _VL measured by the voltage measuring unit 412 and the load resistance R, the above equation (1) is used to calculate _The flowing current I1 can be calculated.

(effect)
As in this modified example, even if the voltage measuring section 412 is connected closer to the load than the current measuring section 414, the current I1 flowing through the electric wire ₁₀₀ can be calculated with high accuracy.

According to this modification, the voltage measurement unit 412 is connected to the load side rather than the current measurement unit 414, so that the load applied to the load side can be measured without depending on the shunt resistor 414r of the current measurement unit 414. Voltage _VL can be measured with high accuracy.

(3-2) Modification 1-2 of the first embodiment
Next, a power supply device 10 according to Modification 1-2 of the present embodiment will be described.

In the power supply device 10 of Modified Example 1-2 of this embodiment, the control method of the control section 500 is different from that of the above embodiment.

(control part)
In this modification, the control unit 500 is configured to specify (restrict) the processing executed by the load when the measuring unit 410 is measuring the load current _{IL and the load voltage VL ,} for example. Here, "to specify (restrict) a process" means to limit a part of a plurality of processes or not to execute all of the plurality of processes. Specifically, the control unit 500 controls the physical quantity measuring unit 640 not to measure the physical quantity of the electric wire 100 while the measuring unit 410 is measuring the load current _{IL and the load voltage VL ,} for example. Further, the control unit 500 controls the radio unit 620 not to transmit or receive information while the measurement unit 410 is measuring the load current _{IL and the load voltage VL ,} for example.

(effect)
According to this modification, the control unit 500 specifies the load processing according to the measurement state of the measurement unit 410, so that the fluctuation of the load resistance R itself can be suppressed. By suppressing the variation of the load resistance R itself, it is possible to suppress the occurrence of an error in the calculated load resistance R due to the variation of the load resistance R. As a result, the measurement accuracy of the current I1 flowing through the electric wire ₁₀₀ can be improved more stably.

(3-3) Modification 1-3 of the first embodiment
Next, a power supply device 10 according to Modification 1-3 of the present embodiment will be described.

The CT section 200 and the measurement section 410 may be configured like the power supply device 10 of Modified Example 1-3 of the present embodiment described below.

(CT department)
Next, magnetization characteristics of the core 220 of the CT section 200 of this modified example will be described with reference to FIG. FIG. 3 is a diagram showing the magnetization characteristics of the core of modification 1-3.

Here, the magnetic field strength H generated around the electric wire ₁₀₀ is proportional to the current I1 flowing through the electric wire 100 . Since the current I1 normally has _a sinusoidal waveform, the magnetic field strength H will have _a sinusoidal waveform proportional to the current I1. In the core 220, a change occurs in the magnetic flux Φ (=BS, B: magnetic flux density, S: area) in the change of the magnetic field strength H as described above. Therefore, according to the following equation (2), an induced current _I2 is generated in the coil 240 by electromagnetic induction based on the amount of change in the magnetic flux Φ generated in the core 220.
_I2 =(N/R)(dΦ/dt) (2)
where, as mentioned above, N is the number of turns of coil 240 and R is the load resistance.

Therefore, in this modified example, an increase in the magnetic flux Φ generated in the core 220 is suppressed so as not to generate an excessive induced current _I2 in the coil 240 .

Specifically, as shown in FIG. 3 , the core 220 of this modified example is designed to provide a power supply around the electric wire ₁₀₀ when the current value of the current I1 flowing through the electric wire 100 is equal to or less than the allowable current value of the electric wire 100, for example. It is configured to be magnetically saturated with respect to the magnetic field generated at As a result, generation of excessive power can be suppressed.

The term "magnetic saturation" used herein means that the magnetic flux density B is constantly saturated with respect to the magnetic field intensity H.

Also, the "permissible current value" here means the maximum value of the current I1 that the electric wire ₁₀₀ can flow (without being damaged). In addition, the "maximum magnetic field strength" in FIG. 3 means the maximum value of the magnetic field strength generated around the electric wire 100 when the current value of the electric wire 100 is the allowable current value.

The magnetization characteristic (magnetization curve) of the core 220 has, for example, a monotonically increasing region MR, a magnetic saturation point SP, and a saturation region SR. The monotonically increasing region MR is a region where the magnetic flux density B monotonically increases with respect to the magnetic field intensity H, for example. The saturation region SR is, for example, a region where the magnetic flux density B is constantly saturated with respect to the magnetic field intensity H. The magnetic saturation point SP is, for example, the point where the magnetic field intensity H changes from the monotonically increasing region MR to the saturated region SR.

In the core 220 of this modified example, for example, the magnetic saturation point SP is positioned below the maximum magnetic field strength _Hp . That is, when the current value of the current I1 flowing through the wire ₁₀₀ is equal to or less than the allowable current value of the wire 100, the core 220 is magnetically saturated.

When the core 220 is magnetically saturated, the magnetic flux density B of the core 220 becomes constant, so the amount of change in the magnetic flux Φ of the core 220 becomes zero. Therefore, the induced current I2 generated in the coil ₂₄₀ is 0 (A) from the above equation (2). As a result, the waveform of the induced current _I2 deviates from the sine wave.

Specifically, the waveform of the induced current _I2 generated in the coil 240 when the core 220 is magnetically saturated will be described with reference to FIGS. 4A and 4B. 4A and 4B are diagrams showing waveforms of the induced current _I2 generated in the coil in Modification 1-3. 4A and 4B show the waveform of induced current _I2 when a predetermined linear resistance is connected to coil 240 (that is, when load resistance R is constant). 4A and 4B, _respectively , the current value of the current I1 is the current value at which the magnetic field strength is near the magnetic saturation _point SP, and the current value of the current I1 is the magnetic field strength saturation region SR. It shows the waveform of the induced current _I2 at the inner current value. Note that the current value of the current I1 is equal to or _less than the allowable current value.

As shown in FIGS. 4A and 4B, when the current value of the current I1 flowing through the wire ₁₀₀ is equal to or less than the allowable current value of the wire 100, the magnetic saturation of the core 220 causes, for example, the current I As the current value of ₁ increases, the waveform of the induced current _I2 generated in the coil 240 can be made into a waveform in which a part of the sine wave is missing, and can be deviated from the sine wave. By setting the waveform of the induced current _I2 to the above waveform, as the current value of the current _I1 increases, the integrated value obtained by integrating the current values of the induced current _I2 is changed to the induced current _I2 without magnetic saturation of the core 220. is obtained as a _sinusoidal wave. In other words, even if there is _an increase in the current I1 flowing through the wire, it is possible to suppress the generation of excessive power that is not necessary for the load.

Note that the above-mentioned "when the core 220 is not magnetically saturated and the induced current _I2 is obtained as a sine wave" means that the slope of the monotonically increasing region MR in the magnetization characteristics of the core 220 is equal to the actual slope of the monotonically increasing region MR. , the magnetic saturation point SP is higher than the maximum magnetic field intensity _Hp and the induced current _I2 is obtained as a sine wave.

Further, as shown in FIG. 4B, when the current value of the current I1 flowing through the wire ₁₀₀ is equal to or less than the allowable current value of the wire 100, the magnetic saturation of the core 220 causes, for example, the current value of the induced current _I2 When the absolute value of the induced current decreases from the peak value (induced current peak value, PK) (DT), the slope when the absolute value of the induced current _I2 rises to the peak value (PK) (UT) can be steeper than By sharply decreasing the absolute value of the current value of the induced current _I2 , a part of the sine wave can be surely omitted. As a result, generation of excessive power can be suppressed.

In addition, as shown in FIG. 4B, the core 220 is magnetically saturated, and the amount of change in the magnetic flux Φ in the above equation (2) becomes 0, so that the waveform of the induced current _I2 changes to the current of the induced current _I2 After the absolute value of the value drops from the peak value, the induced current _I2 has a zero current region (ZT) where the current value is constant at 0 A for a predetermined time. Since the waveform of the induced current _I2 has a zero current region (ZT), it is possible to reliably ensure a time during which a part of the sine wave is missing. As a result, generation of excessive power can be stably suppressed.

As shown in FIGS. 4A and 4B, even if the waveform of the induced current _I2 generated in the coil 240 is a waveform that lacks a part of the sine wave, the waveform shaping section 360 of the power supply section 300 will apply the current to the load. It is shaped into a suitable current waveform (constant current waveform).

Further, in the core 220 showing the waveform of the induced current _I2 shown in FIGS. 4A and 4B, for example, the current value of the current I1 of the wire ₁₀₀ when the core 220 begins to be magnetically saturated is the current I1 of the wire ₁₀₀ is within ±10% of the lower limit of the operating range in which the peak value of As a result, the magnetic saturation of the core 220 can be obtained over substantially the entire operating range of the peak value of the electric wire ₁₀₀ current I1. That is, when the current value of the current I1 of the electric wire ₁₀₀ becomes larger than the lower limit value of the operating range, the core 220 can be immediately magnetically saturated. If the CT unit 200 and the power supply unit 300 are designed so that sufficient power can be obtained when the current value of the current I1 is the lower limit value of the above operating range, the _entire steady _- state range of the peak current value of the current I1 It is possible to suppress unnecessary and excessive power supply to the load over the entire period.

(Measuring part)
In this modification, as described above, the core 220 is configured to be magnetically saturated, and the _waveform of the induced current _I2 generated in the coil 240 becomes a waveform in which a part of the sine wave is missing. Each waveform of the voltage _VL also becomes a waveform in which a part of the sine wave is missing.

Therefore, in this modified example, measurement section 410 measures the effective value or peak value of each of load current _IL and load voltage _VL , for example. Note that the effective value corresponds to an integral value.

(effect)
(a) The core 220 is configured to be magnetically saturated with respect to the magnetic field generated around the electric wire ₁₀₀ when the current value of the current I1 flowing through the electric wire 100 is equal to or less than the allowable current value of the electric wire 100 . As _a result, as the current value of the current I1 increases, the waveform of the induced current _I2 can be made into a waveform in which a part of the sine wave is missing, and deviated from the sine wave. By setting the waveform of the induced current _I2 to the above waveform, as the current value of the current _I1 increases, the integrated value obtained by integrating the current values of the induced current _I2 is changed to the induced current _I2 without magnetic saturation of the core 220. is obtained as a _sinusoidal wave. Also, when the current value of the current I1 increases, the rate of increase of the integrated value obtained by integrating the current values of the induced current _I2 is made smaller _than the rate of increase of the integrated value obtained by integrating the current values of the current _I1 . be able to. In other words, even if the current I1 flowing through the electric wire ₁₀₀ increases, it is possible to suppress the generation of excessive power unnecessary for the load. As a result, stable power can be obtained.

(b) The measurement unit 410 measures the effective value or peak value of each of the load current _{IL and the load voltage VL ,} thereby specifying the respective values of the load current _IL and the load voltage _VL as constant values. can do. Accordingly, even if the waveforms of the load current _{IL and the load voltage VL deviate} from the sine wave due to magnetic saturation of the core 220, the load resistance R can be accurately calculated. As a result, even if the core 220 is magnetically saturated, the current I1 flowing through the electric wire ₁₀₀ can be calculated with high accuracy.

<Second embodiment of the present invention>
The power supply device 10 of the present embodiment differs from the first embodiment in that the CT section 200 has two coils. Only elements different from the first embodiment will be described below, as in the modification of the first embodiment.

(1) Electric Wire Physical Quantity Measuring Device A power supply device 10 according to the present embodiment will be described with reference to FIG. FIG. 5 is a schematic configuration diagram showing a power supply device according to this embodiment.

The power supply device 10 of the present embodiment includes, for example, a CT section 200, a power supply section 300, a second coil side measurement section 440, a control section 500, a radio section 620, and a physical quantity measurement section 640. .

(CT department)
The CT section 200 of this embodiment has two coils 240 for one core 220, for example. One of the two coils 240 is called "first coil 242" and the other is called "second coil 244".

In this embodiment, for example, the first coil 242 is used for power supply and the second coil 244 is used for current measurement.

A core 220 of the present embodiment is axially split in half and has a first core half portion 222 and a second core half portion 224, as in the first embodiment described above. For example, a first coil 242 is wound on the first core half 222 and a second coil 244 is wound on the second core half 224 .

(Power supply part)
The power supply unit 300 of the present embodiment is configured to be connected to, for example, the first coil 242 and supply power to the load based on the induced current generated in the first coil 242 . For example, the power supply unit 300 has a protection unit 320, a rectification unit 340, and a waveform shaping unit 360, and the protection unit 320, the rectification unit 340, and the waveform shaping unit 360 are arranged in this order from the first coil 242 toward the load side. arranged (in parallel). Waveform shaping section 360 is connected in parallel with, for example, control section 500, physical quantity measurement section 640, and radio section 620 as loads.

(Second coil side measurement unit)
In this embodiment, a linear resistor 700 is connected to the second coil 244, for example.
For example, the second coil side measuring section 440 is connected in parallel with the second coil 244 between the second coil 244 and the linear resistor 700 .

The second coil side measuring section 440 is configured to measure the induced voltage E2 generated in the _second coil 244, for example.

(current calculator)
The current calculation unit 520 included in the control unit 500 is connected to, for example, the second coil-side measurement unit 440, and based on the induced voltage E2 measured by the _second coil-side measurement unit 440, by the following formula (3): It is configured to calculate the current I1 flowing through the electric wire ₁₀₀ .
I1 _{= E2N2K} / _R2 ( ₃ )
where _N2 is the number of turns of the second coil 244 and K is the coupling coefficient.

(Case)
The power supply device 10 holds, for example, a CT unit 200, a power supply unit 300, a control unit 500, a part of the physical quantity measurement unit 640, a radio unit 620, a linear resistance 700, and a second coil side measurement unit 440 outside the electric wire 100. It has a housing (not shown) for

The housing has, for example, a first housing half (not shown) and a second housing half (not shown) that are split in half along the axial direction. The first housing half part accommodates, for example, the first core half part 222 around which the first coil 242 is wound, the power supply unit 300, part of the physical quantity measurement unit 640, and the radio unit 620. is doing. Note that the temperature sensor section as the physical quantity measuring section 640 may be provided outside the first housing half-split section. On the other hand, the second housing half portion accommodates, for example, the second core half portion 224 around which the second coil 244 is wound, the linear resistor 700, and the second coil side measuring portion 440. .

Thus, the members associated with the first coil 242 are housed within the first housing half, and the members associated with the second coil 244 are housed within the second housing half.

(2) Effects According to the Present Embodiment According to the present embodiment, one or more of the following effects can be obtained.

(a) In the power supply device 10 of the present embodiment, a first coil 242 for obtaining a predetermined power and a second coil 244 for measuring the current I1 flowing through the electric wire 100 are connected to _one core 220. , a linear resistor 700 with a constant resistance can be connected to the second coil 244 side instead of a load with a variable resistance. That is, on the second coil 244 side, it is possible to suppress fluctuations in resistance. By suppressing the resistance variation on the second coil 244 side, the current I1 flowing through the electric wire ₁₀₀ can be stably calculated by the above equation (3).

(b) In this embodiment, the core 220 is split in half along the axial direction. Also, the first coil 242 is wound around the first core half portion 222 and the second coil 244 is wound around the second core half portion 224 . This allows the members associated with the first coil 242 to be accommodated within the first housing half, and the members associated with the second coil 244 to be accommodated within the second housing half. By dividing the housing for each member related to each coil, the wiring inside each of the first housing half part and the second housing half part is shortened, and the first housing half part It is possible to suppress the wiring from straddling between the second housing half portion and the second housing half portion. As a result, the power supply device 10 can be easily attached to the existing electric wire 100, and the power supply device 10 can be easily assembled (manufactured).

(3) Modifications of Second Embodiment The above-described second embodiment can be modified as in the following modifications, if necessary. Only elements different from the above-described second embodiment will be described below, as in the modification of the first embodiment.

(3-1) Modified example 2-1 of the second embodiment
A power supply device 10 according to Modification 2-1 of the present embodiment will be described with reference to FIG. FIG. 6 is a schematic configuration diagram showing a power supply device according to modification 2-1 of the present embodiment.

The power supply device 10 of Modified Example 2-1 of this embodiment differs from the above embodiment in that a first coil-side measuring section 420 is provided.

(First coil side measurement unit)
The first coil side measuring unit 420 is connected between the first coil 242 and the load, for example, and measures the load current _{IL flowing to the load side and the load voltage VL applied} to the load side. It is configured. The load current I _L and the load voltage V _L measured by the first coil side measuring section 420 are used to obtain the load resistance R on the load side.

The first coil side measuring section 420 is connected at least closer to the first coil 242 than the rectifying section 340, for example. Thus, as in the first embodiment, the load resistance R including the parasitic resistance components of the rectifying section 340 and the waveform shaping section 360 can be obtained.

(current calculator)
The current calculation unit 520 included in the control unit 500 of this modification is connected to, for example, the first coil-side measurement unit 420 and the second coil-side measurement unit 440, and is configured to calculate the current I1 flowing through the electric wire ₁₀₀ . there is Specifically, the current calculator 520 of the present modified example calculates the current _I1 according to the following procedure, for example.

First, based on the load current I _L and the load voltage V _L measured by the first coil-side measurement unit 420, the load resistance R on the load side is calculated by the same procedure as in the above-described first embodiment.

On the other hand, based on the induced voltage E2 measured by the _second coil side measuring section 440, the current I1 flowing through the electric wire ₁₀₀ is calculated by the following equation (4).
I1 _{= αE2N2K} / _R2 ( ₄ )
where _N2 is the number of turns of the second coil 244 and K is the coupling coefficient, as described above. α is a correction coefficient determined by a load resistance R configured by power supply section 300 , control section 500 , radio section 620 and physical quantity measurement section 640 connected to first coil 242 .

At this time, the correction coefficient α is obtained from the load resistance R calculated based on the load current I _L and the load voltage V _L measured by the first coil side measuring unit 420, and the correction coefficient α is substituted into the equation (4). .

Specifically, the correction coefficient α is obtained by the following procedure. First, the current I1 flowing through the electric wire 100 is calculated with a correction coefficient α= ₁ when the load is not executing any process and the load resistance R is not fluctuating. Let it be _I1C . On the other hand, when the current I1 flowing through the wire ₁₀₀ is known in advance to be the current _I1C , the load executes a predetermined process to change the load resistance R. At this time, the induced voltage E ₂ and I ₁ =I _1C measured by the second coil side measuring section 440 are substituted into the equation (4) to obtain the dependence of the correction coefficient α on the varying load resistance R. When measuring the actual current I1, _first , the current load resistance R is obtained, and based on the dependence of the correction coefficient α on the load resistance R described above, the correction coefficient α for the current load resistance R is obtained.
When the correction coefficient α for the current load resistance R is obtained, the currently calculated correction coefficient α and the induced voltage E2 measured by the _second coil side measuring unit 440 are substituted into the equation (4) to obtain the true , the current _I1 can be obtained.

(effect)
According to this modification, when the current _I1 is calculated based on the induced voltage E2 measured by the _second coil-side measuring unit 440, the load current IL measured by the _first coil-side measuring unit 420 and the load voltage A load resistance R is calculated based on _VL . This allows the current current _I1 to be corrected by the load resistor R.

Here, although the first coil 242 and the second coil 244 are separated in this embodiment, they share the core 220 . Therefore, when the load resistance R varies on the first coil 242 side, the variation in the load resistance R on the first coil 242 side affects the magnetic flux Φ generated in the core 220 . If the peak value of the magnetic flux Φ of the core 220 fluctuates due to fluctuations in the load resistance R, the induced voltage E2 generated in the _second coil 244 may fluctuate. For this reason, there is _a possibility that an error will occur with respect to the true current I1 that should be originally obtained.

On the other hand, according to this modification, even if the magnetic flux Φ of the core 220 fluctuates due to the fluctuation of the load resistance R, and the induced voltage E2 generated in the _second coil 244 fluctuates, the load resistance R is corrected. By obtaining the coefficient α and substituting the correction coefficient α into the equation ( ₄ ), the true current I1 can be obtained. This makes it possible to suppress the occurrence of _an error in the current I1.

(3-2) Modified example 2-2 of the second embodiment
Next, a power supply device 10 according to modification 2-2 of the present embodiment will be described.

In the power supply device 10 of Modified Example 2-2 of this embodiment, the control method of the control section 500 is different from that of the above embodiment.

(control part)
In this modification, the control unit 500 specifies (limits) the process executed by the load when the second coil side measuring unit 440 is measuring the induced voltage E2 generated in the _second coil 244, for example. It is configured. Specifically, the control unit 500 controls the physical quantity measuring unit 640 not to measure the physical quantity of the electric wire 100, for example, while the _second coil side measuring unit 440 is measuring the induced voltage E2. Also, the control unit 500 controls the radio unit 620 not to transmit or receive information while the _second coil side measuring unit 440 is measuring the induced voltage E2, for example.

(effect)
According to this modification, the control unit 500 specifies the load processing according to the measurement state of the measurement unit 410, so that the fluctuation of the load resistance R itself can be suppressed. Fluctuations in the magnetic flux Φ of the core 220 due to fluctuations in the load resistance R can be suppressed. By suppressing the fluctuation of the magnetic flux Φ of the core 220, the fluctuation of the induced voltage E2 generated in the _second coil 244 can be suppressed. By suppressing fluctuations in the induced voltage _E2 , it is possible to suppress the occurrence of errors in the current _I1 .

(3-3) Modified example 2-3 of the second embodiment
Next, a power supply device 10 according to Modification 2-3 of the present embodiment will be described.

The CT section 200 and the second coil side measurement section 440 may be configured like the power supply device 10 of Modified Example 2-3 of the present embodiment described below.

(CT department)
The core 220 of this modified example has magnetization characteristics (see FIG. 3) similar to those of the modified example 1-3 of the first embodiment. That is, core 220 is configured to be magnetically saturated with respect to the magnetic field generated around electric wire 100 when the current value of current I1 flowing through electric wire ₁₀₀ is equal to or less than the allowable current value of electric wire 100 . As a result, the waveform of the induced current _I2 generated in the _first coil 242 can diverge from the sine wave as the current value of the current I1 increases. As a result, it is possible to suppress the generation of excessive power that is not necessary for the load.

(Measuring part)
In this modification, as described above, since the core 220 is magnetically saturated, the waveform of the induced voltage E2 generated in the _second coil 244 also becomes a waveform in which a part of the sine wave is missing.

Therefore, in this modified example, the second coil side measuring section 440 measures the effective value or peak value of the induced voltage E2 generated in the _second coil 244, for example.

(effect)
According to this modified example, the value of the induced voltage E2 can be specified as a constant value by the _second coil _side measuring section 440 measuring the effective value or the peak value of the induced voltage E2. As a result, even if the waveform of the induced voltage E2 deviates from the sine wave due to magnetic saturation of the core 220, the current I1 flowing through the electric wire ₁₀₀ can be calculated with _high accuracy.

<Other embodiments of the present invention>
Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

In addition, when it says "the above-mentioned embodiment" below, it means "at least one embodiment of 1st Embodiment and 2nd Embodiment."

Although the above-mentioned embodiment demonstrated the case where the power supply device 10 was applied to a wire physical-quantity measuring device, it is not restricted to this case. For example, the power supply device 10 may be applied to wireless communication devices. In this case, the power supply device 10 does not have the physical quantity measuring section 640 other than the measuring section 410 in the above embodiments. Alternatively, for example, the power supply device 10 may be a device other than a wire physical quantity measuring device or a wireless communication device as long as it is a device that needs to obtain power from the wire 100 .

In the first embodiment described above, the case where the measurement unit 410 is connected between the coil 240 and the protection unit 320 has been described. It may be connected between 320 and the rectifying section 340 . This is because the protector 320 can be ignored when measuring the load resistance R, as described above. It should be noted that the first coil-side measuring section 420 may be connected in the same manner as described above also in the modified example 2-1 of the second embodiment.

In the above-described embodiment, the case where the control unit 500 is configured by an MCU has been described, but it is not limited to this case. For example, the control unit 500 may be configured by a general-purpose computer having a CPU (Central Processing Unit), a RAM (Random Access Memory), and a storage device.

In the above-described embodiment, the case where the power supply device 10 has the wireless unit 620 has been described, but the power supply device 10 may have a transmission unit or a transmission/reception unit that transmits or transmits/receives various types of information by wire.

In the above-described embodiment, the case where the wireless unit 620 is configured to transmit various data by multi-hop wireless communication has been described, but the present invention is not limited to this case. For example, if radio section 620 is configured to enable long-distance transmission, radio section 620 may be configured to directly transmit various data to a data aggregation transmission device or an electric power company.

In the second embodiment described above, the case where the first coil 242 is wound around the first core half portion 222 and the second coil 244 is wound around the second core half portion 224 has been described. If the first coil 242 and the second coil 244 do not interfere with the coupling between the first core half portion 222 and the second core half portion 224, the first coil 242 and the second coil 244 will overlap each other. may have Furthermore, each of the first coil 242 and the second coil 244 may be wound around the entire circumference of the core 220 .

In the modification 2-3 of the second embodiment described above, the core 220 is configured to be magnetically saturated, and the _second coil side measurement unit 440 measures the effective value or peak value of the induced voltage E2. However, in the modification 2-3, when the first coil side measuring section 420 is provided, the first coil side measuring section 420 measures, for example, each of the load current _{IL and the load voltage VL .} It may be configured to measure rms or peak values. Thus, even if the core 220 is magnetically saturated, the current _I1 can be accurately corrected by the load resistance R.

In the first embodiment described above, the case where the power supply device 10 has the current calculation unit 520 has been described, but the current calculation unit may be provided outside the power supply device. In this case, for example, a power supply system is configured by the power supply device and the monitoring device. The power supply does not have a current calculator. A radio unit (transmitting unit) included in the power supply transmits information related to the load current and load voltage measured by the measuring unit to the outside. On the other hand, the monitoring device has a current calculator. The current calculation unit receives information about the load current and the load voltage from the radio unit, calculates the load resistance on the load side based on the load current and the load voltage measured by the measurement unit, and calculates the induced voltage and the load resistance generated in the coil. Calculate the current of the wire based on

In the above-described second embodiment, the case where the power supply device 10 has the current calculation unit 520 has been described, but the current calculation unit may be provided outside the power supply device. In this case, for example, a power supply system is configured by the power supply device and the monitoring device. The power supply does not have a current calculator. A radio unit (transmitting unit) included in the power supply device transmits information related to the induced voltage measured by the second coil side measuring unit to the outside. On the other hand, the monitoring device has a current calculator. The current calculator receives information about the induced voltage from the radio unit, and calculates the current of the wire based on the induced voltage measured by the second coil-side measuring unit.

The above first embodiment, modifications 1-1 to 1-3 of the first embodiment, second embodiment, and modifications 2-1 to 2-3 of the second embodiment are combined as much as possible. good too.

<Preferred embodiment of the present invention>
Preferred embodiments of the present invention are described below.

(Appendix 1)
a core provided to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
connected to the measuring unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and calculating the current based on the induced voltage generated in the coil and the load resistance a current calculation unit for
power supply.

(Appendix 2)
The power supply unit
a rectification unit that rectifies the induced current of alternating current generated in the coil to direct current;
a waveform shaping unit provided closer to the load than the rectifying unit and configured to shape the waveform of the induced current rectified to direct current;
has
The power supply device according to appendix 1, wherein the measurement unit is connected at least closer to the coil than the rectification unit.

(Appendix 3)
The power supply unit has a protection unit that protects the load from surge current,
the protection unit, the rectification unit, and the waveform shaping unit are arranged in this order from the coil side toward the load side,
The power supply device according to appendix 2, wherein the measurement unit is connected between the coil and the protection unit.

(Appendix 4)
The power supply unit has a protection unit that protects the load from surge current,
the protection unit, the rectification unit, and the waveform shaping unit are arranged in this order from the coil side toward the load side,
The power supply device according to appendix 2, wherein the measurement unit is connected between the protection unit and the rectification unit.

(Appendix 5)
Having the current calculation unit and having a control unit that controls the load with the power from the power supply unit,
5. The power supply device according to any one of Appendices 1 to 4, wherein the control unit specifies the processing to be executed by the load while the measurement unit is measuring the load current and the load voltage.

(Appendix 6)
6. Any one of appendices 1 to 5, wherein the core is configured to be magnetically saturated with respect to a magnetic field generated around the electric wire when a current value of the current flowing through the electric wire is equal to or less than an allowable current value of the electric wire. 1. The power supply of claim 1.

(Appendix 7)
7. The power supply device according to appendix 6, wherein the measurement unit measures an effective value or a peak value of each of the load current and the load voltage.

(Appendix 8)
A power system comprising a power supply and a monitoring device,
The power supply device
a core provided to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
a transmission unit connected to the power supply unit as one of the loads, and transmitting information related to the load current and the load voltage measured by the measurement unit to the outside;
has
The monitoring device
receiving information about the load current and the load voltage from the transmitting unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and generating an induced voltage in the coil; and a current calculator that calculates the current based on the load resistance.

(Appendix 9)
a core provided in an annular shape so as to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a current calculation unit connected to the second coil-side measurement unit and calculating the current based on the induced voltage measured by the second coil-side measurement unit;
power supply.

(Appendix 10)
The core is halved along the axial direction,
The first coil is wound around one half of the core,
The power supply device according to appendix 9, wherein the second coil is wound around the other half of the core.

(Appendix 11)
outside the wire, a housing for holding the core, the power supply unit, the second coil side measurement unit, and the current calculation unit;
The housing has a first housing half and a second housing half divided in half along the axial direction,
the first housing half part accommodates one half of the core around which the first coil is wound and the power supply part;
Supplementary Note 10: The second housing half part accommodates the other half of the core around which the second coil is wound, the second coil side measurement part, and the current calculation part. A power supply as described in .

(Appendix 12)
a first coil side measurement unit connected between the first coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
The current calculator is further connected to the first coil-side measuring unit, calculates a load resistance on the load side based on the load current and the load voltage measured by the first coil-side measuring unit, 12. The power supply device according to any one of appendices 9 to 11, wherein the current calculated based on the induced voltage measured by the two-coil side measuring unit is corrected by the load resistance.

(Appendix 13)
The power supply unit
a rectification unit that rectifies the induced current of alternating current generated in the first coil to direct current;
a waveform shaping unit provided closer to the load than the rectifying unit and configured to shape the waveform of the induced current rectified to direct current;
has
13. The power supply device according to appendix 12, wherein the first coil-side measuring section is connected at least closer to the first coil than the rectifying section.

(Appendix 14)
Having the current calculation unit and having a control unit that controls the load with the power from the power supply unit,
14. The power supply device according to any one of appendices 9 to 13, wherein the control unit specifies a process to be executed by the load while the second coil side measurement unit is measuring the induced voltage.

(Appendix 15)
15. Any one of appendices 9 to 14, wherein the core is configured to be magnetically saturated with respect to a magnetic field generated around the electric wire when the current value of the current flowing through the electric wire is equal to or less than the allowable current value of the electric wire. 1. The power supply of claim 1.

(Appendix 16)
16. The power supply device according to appendix 15, wherein the second coil-side measurement unit measures an effective value or a peak value of the induced voltage.

(Appendix 17)
a first coil side measurement unit connected between the first coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
17. The power supply device according to appendix 15 or 16, wherein the first coil side measurement unit measures an effective value or a peak value of each of the load current and the load voltage.

(Appendix 18)
A power system comprising a power supply and a monitoring device,
The power supply device
a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a transmission unit connected to the power supply unit as one of the loads and transmitting to the outside information related to the induced voltage measured by the second coil side measurement unit;
has
The monitoring device
A power supply system comprising a current calculator that receives information about the induced voltage from the transmitter and calculates the current based on the induced voltage measured by the second coil-side measuring unit.

(Appendix 19)
a core provided to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
connected to the measuring unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and calculating the current based on the induced voltage generated in the coil and the load resistance a current calculation unit for
a physical quantity measuring unit that is configured as one of the loads and measures a physical quantity related to the electric wire by the power supplied from the power supply unit;
An electric wire physical quantity measuring device.

(Appendix 20)
a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a current calculation unit connected to the second coil-side measurement unit and calculating the current based on the induced voltage measured by the second coil-side measurement unit;
a physical quantity measuring unit that is configured as one of the loads and measures a physical quantity related to the electric wire by the power supplied from the power supply unit;
An electric wire physical quantity measuring device.

(Appendix 21)
a core provided to surround the electric wire;
a coil that is wound around the core and that generates an induced current by electromagnetic induction based on a change in magnetic flux generated in the core by the current flowing in the electric wire;
a power supply unit connected to the coil and supplying power to a predetermined load based on the induced current generated in the coil;
a measuring unit connected between the coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
connected to the measuring unit, calculating the load resistance on the load side based on the load current and the load voltage measured by the measuring unit, and calculating the current based on the induced voltage generated in the coil and the load resistance a current calculation unit for
a radio unit that is configured as one of the loads and that wirelessly transmits and receives predetermined information using the power supplied from the power supply unit;
A wireless communication device comprising:

(Appendix 22)
a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a current calculation unit connected to the second coil-side measurement unit and calculating the current based on the induced voltage measured by the second coil-side measurement unit;
a radio unit that is configured as one of the loads and that wirelessly transmits and receives predetermined information using the power supplied from the power supply unit;
A wireless communication device comprising:

10 power supply device 100 electric wire 200 current transformer section (CT section)
220 core 222 first core half-split part 224 second core half-split part 240 coil 242 first coil 244 second coil 300 power supply unit 320 protection unit 340 rectifying unit 360 waveform shaping unit 410 measuring unit 412 voltage measuring unit 414 current measuring unit 414r shunt resistor 414v voltmeter 420 first coil side measurement unit 440 second coil side measurement unit 500 control unit 520 current calculation unit 620 radio unit 640 physical quantity measurement unit 700 linear resistance

Claims (8)

a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a current calculation unit connected to the second coil-side measurement unit and calculating the current based on the induced voltage measured by the second coil-side measurement unit;
A power supply. The core is halved along the axial direction,
The first coil is wound around one half of the core,
The power supply device according to claim 1, wherein the second coil is wound around the other half of the core. a first coil side measurement unit connected between the first coil and the load for measuring a load current flowing to the load side and a load voltage applied to the load side;
The current calculator is further connected to the first coil-side measuring unit, calculates a load resistance on the load side based on the load current and the load voltage measured by the first coil-side measuring unit, The power supply device according to claim 1 or 2, wherein the current calculated based on the induced voltage measured by the two-coil side measuring section is corrected by the load resistance. The power supply unit
a rectification unit that rectifies the induced current of alternating current generated in the first coil to direct current;
a waveform shaping unit provided closer to the load than the rectifying unit and configured to shape the waveform of the induced current rectified to direct current;
has
The power supply device according to claim 3, wherein the first coil side measuring section is connected at least closer to the first coil side than the rectifying section. Having the current calculation unit and having a control unit that controls the load with the power from the power supply unit,
When the second coil-side measuring unit is measuring the induced voltage, the control unit limits a part of a plurality of processes to be executed by the load, or the load is executed. The power supply device according to any one of claims 1 to 4, wherein the processing executed by the load is restricted by preventing execution of all of the processing performed by the load. 6. The core is configured to be magnetically saturated with respect to a magnetic field generated around the electric wire when a current value of the current flowing through the electric wire is equal to or less than an allowable current value of the electric wire. The power supply device according to any one of Claims 1 to 3. The power supply device according to claim 6, wherein the second coil side measuring section measures an effective value or a peak value of the induced voltage. A power system comprising a power supply and a monitoring device,
The power supply device
a core provided to surround the electric wire;
a first coil and a second coil that are wound around the core and generate an induced current by electromagnetic induction based on a change in the magnetic flux generated in the core by the current flowing through the electric wire;
a power supply unit connected to the first coil and supplying power to a predetermined load based on the induced current generated in the first coil;
a second coil-side measurement unit connected to the second coil and measuring an induced voltage generated in the second coil;
a transmission unit connected to the power supply unit as one of the loads and transmitting to the outside information related to the induced voltage measured by the second coil side measurement unit;
has
The monitoring device
A power supply system comprising a current calculator that receives information about the induced voltage from the transmitter and calculates the current based on the induced voltage measured by the second coil-side measuring unit.

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