JP2021068933A - Power receiving device, power supply device, and optical fiber power supply system - Google Patents

Abstract

To provide a power receiving device, a power supply device, and an optical fiber power supply system that can reduce excess and deficiency of electric power supplied by power supply light.SOLUTION: A power receiving device (310C) comprises: a photoelectric conversion element (311) that converts power supply light input from the outside of the device into electric power; a power monitoring unit (315) that monitors surplus power; a light returning unit (312) that can output part of the power supply light (112) to the outside of the device as return light; and a return control unit (314) that controls the light returning unit (312) based on a result of monitoring performed by the power monitoring unit (315). A power supply device (110C) comprises: a laser oscillation unit (111) that converts electric power into power supply light and outputs the power supply light to the outside of the device; a light receiving element (114) that receives the return light (313) returned from the outside of the device; and a power control unit (115) that controls the power of the power supply light (112) based on the return light (313).SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a power receiving device, a power feeding device, and an optical fiber power feeding system.

Recently, an optical power supply system that converts electric power into light (called feed light) and transmits it, converts the feed light into electric energy, and uses it as electric power has been studied. Patent Document 1 describes an optical transmitter that transmits signal light modulated by an electric signal and feed light for supplying power, a core that transmits the signal light, and a core formed around the core. An optical fiber having a first clad having a small refractive index and transmitting the feeding light and a second clad formed around the first clad and having a smaller refractive index than the first clad, and a first clad of the optical fiber are used for transmission. Described is an optical communication device including an optical receiver that operates with the converted power of the fed light and converts the signal light transmitted by the core of the optical fiber into the electric signal.

Japanese Unexamined Patent Publication No. 2010-135989

In the conventional optical power supply system, the magnitude of the power supply light sent from the power supply device to the power receiving device is set in advance on the power supply side. Therefore, when the magnitude of power consumption on the power receiving side changes, it is difficult to make the magnitude of the feeding light correspond to this change. In this case, there is a risk of surplus power in the power receiving device.

An object of the present disclosure is to provide a power receiving device, a power feeding device, and an optical fiber power feeding system in which the power supplied by the feeding light can follow the power consumption on the power receiving side.

The power receiving device of the present disclosure is
A photoelectric conversion element that converts the feed light input from outside the device into electric power,
The power monitoring unit that monitors surplus power and
An optical return unit that outputs a part of the feed light as return light to the outside of the device.
It includes a return control unit that controls the optical return unit based on the monitoring result of the power monitoring unit.

The power supply device of the present disclosure is
A laser oscillator that converts power into feed light and outputs it to the outside of the device,
A light receiving element that receives the return light returned from outside the device,
A power control unit that controls the power of the feed light based on the return light,
To be equipped.

The optical fiber power supply system of the present disclosure is
The above power receiving device, the above power supply device,
The optical fiber that transmits the feed light and
The optical fiber that transmits the return light and
To be equipped.

According to the present disclosure, it is possible to obtain an effect that the surplus of electric power supplied from the power feeding device to the power receiving device can be suppressed by the feeding light.

It is a block diagram of the optical fiber power supply system which concerns on 1st Embodiment of this disclosure. It is a block diagram of the optical fiber power supply system which concerns on 2nd Embodiment of this disclosure. It is a block diagram of the optical fiber power supply system which concerns on 2nd Embodiment of this disclosure, and shows the optical connector and the like. It is a block diagram of the optical fiber power supply system which concerns on another Embodiment of this disclosure. It is a block diagram which shows the optical fiber feeding system which concerns on 3rd Embodiment to which the means which returns a part of the feeding light is applied. It is a time chart which shows an example of the operation of the optical fiber feeding system of 3rd Embodiment.

An embodiment of the present disclosure will be described below with reference to the drawings.

(1) System overview [First embodiment]
As shown in FIG. 1, the optical fiber power supply (PoF: Power over Fiber) system 1A of the present embodiment includes a power supply device (PSE: Power Sourcing Equipment) 110, an optical fiber cable 200A, and a power receiving device (PD: Powered Device) 310. Be prepared.
The power feeding device in the present disclosure is a device that converts electric power into light energy and supplies it, and a power receiving device is a device that receives the supply of light energy and converts the light energy into electric power.
The power feeding device 110 includes a power feeding semiconductor laser 111.
The optical fiber cable 200A includes an optical fiber 250A that forms a transmission line for feeding light.
The power receiving device 310 includes a photoelectric conversion element 311.

The power feeding device 110 is connected to a power source, and a power feeding semiconductor laser 111 or the like is electrically driven.
The power feeding semiconductor laser 111 oscillates with the electric power from the power source and outputs the power feeding light 112.

In the optical fiber cable 200A, one end 201A can be connected to the power feeding device 110, and the other end 202A can be connected to the power receiving device 310 to transmit the feeding light 112.
The power feeding light 112 from the power feeding device 110 is input to one end 201A of the optical fiber cable 200A, the feeding light 112 propagates in the optical fiber 250A, and is output from the other end 202A to the power receiving device 310.

The photoelectric conversion element 311 converts the feed light 112 transmitted through the optical fiber cable 200A into electric power. The electric power converted by the photoelectric conversion element 311 is used as the driving power required in the power receiving device 310. Further, the power receiving device 310 can output the electric power converted by the photoelectric conversion element 311 for an external device.

The semiconductor material constituting the semiconductor region that exerts the light-electric conversion effect of the power feeding semiconductor laser 111 and the photoelectric conversion element 311 is a semiconductor having a short wavelength laser wavelength of 500 nm or less.
Since a semiconductor having a short wavelength laser wavelength has a large band gap and high photoelectric conversion efficiency, the photoelectric conversion efficiency on the power generation side and the power receiving side of optical power supply is improved, and the optical power supply efficiency is improved.
For that purpose, as the semiconductor material, for example, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) of 200 to 500 nm, such as diamond, gallium oxide, aluminum nitride, and GaN, may be used.
Further, as the semiconductor material, a semiconductor having a band gap of 2.4 eV or more is applied.
For example, a semiconductor material of a laser medium having a bandgap of 2.4 to 6.2 eV, such as diamond, gallium oxide, aluminum nitride, and GaN, may be used.
The longer the wavelength of the laser light, the better the transmission efficiency, and the shorter the wavelength, the better the photoelectric conversion efficiency. Therefore, in the case of long-distance transmission, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) larger than 500 nm may be used. When the photoelectric conversion efficiency is prioritized, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) smaller than 200 nm may be used.
These semiconductor materials may be applied to either one of the power feeding semiconductor laser 111 and the photoelectric conversion element 311. The photoelectric conversion efficiency on the power feeding side or the power receiving side is improved, and the optical power feeding efficiency is improved.

[Second Embodiment]
As shown in FIG. 2, the optical fiber power supply (PoF: Power over Fiber) system 1 of the present embodiment includes a power supply system via an optical fiber and an optical communication system, and is a power supply device (PSE: Power Sourcing Equipment) 110. A first data communication device 100 including the above, an optical fiber cable 200, and a second data communication device 300 including a power receiving device (PD) 310.
The power feeding device 110 includes a power feeding semiconductor laser 111. The first data communication device 100 includes a power supply device 110, a transmission unit 120 that performs data communication, and a reception unit 130. The first data communication device 100 corresponds to a data terminal equipment (DTE: Date Terminal Equipment), a repeater (Repeater), and the like. The transmitter 120 includes a signal semiconductor laser 121 and a modulator 122. The receiving unit 130 includes a signal photodiode 131.

The optical fiber cable 200 includes an optical fiber 250 having a core 210 forming a signal light transmission path and a clad 220 arranged on the outer periphery of the core 210 and forming a feeding light transmission path.

The power receiving device 310 includes a photoelectric conversion element 311. The second data communication device 300 includes a power receiving device 310, a transmitting unit 320, a receiving unit 330, and a data processing unit 340. The second data communication device 300 corresponds to a power end station or the like. The transmitter 320 includes a signal semiconductor laser 321 and a modulator 322. The receiving unit 330 includes a signal photodiode 331. The data processing unit 340 is a unit that processes a received signal. The second data communication device 300 is a node in the communication network. Alternatively, the second data communication device 300 may be a node that communicates with another node.

The first data communication device 100 is connected to a power source, and a power feeding semiconductor laser 111, a signal semiconductor laser 121, a modulator 122, a signal photodiode 131, and the like are electrically driven. The first data communication device 100 is a node in the communication network. Alternatively, the first data communication device 100 may be a node that communicates with another node.
The power feeding semiconductor laser 111 oscillates with the electric power from the power source and outputs the power feeding light 112.

The photoelectric conversion element 311 converts the feeding light 112 transmitted through the optical fiber cable 200 into electric power. The electric power converted by the photoelectric conversion element 311 is the driving power of the transmitting unit 320, the receiving unit 330, and the data processing unit 340, and other driving power required in the second data communication device 300. Further, the second data communication device 300 may be capable of outputting the electric power converted by the photoelectric conversion element 311 for an external device.

On the other hand, the modulator 122 of the transmitting unit 120 modulates the laser light 123 from the signal semiconductor laser 121 based on the transmission data 124 and outputs it as the signal light 125.
The signal photodiode 331 of the receiving unit 330 demodulates the signal light 125 transmitted through the optical fiber cable 200 into an electric signal and outputs it to the data processing unit 340. The data processing unit 340 transmits the data obtained by the electric signal to the node, while receiving the data from the node and outputting the data as the transmission data 324 to the modulator 322.
The modulator 322 of the transmitting unit 320 modulates the laser light 323 from the signal semiconductor laser 321 based on the transmission data 324 and outputs it as the signal light 325.
The signal photodiode 131 of the receiving unit 130 demodulates the signal light 325 transmitted through the optical fiber cable 200 into an electric signal and outputs it. The data from the electrical signal is transmitted to the node, while the data from the node is referred to as transmission data 124.

The feed light 112 and the signal light 125 from the first data communication device 100 are input to one end 201 of the optical fiber cable 200, the feed light 112 propagates through the clad 220, the signal light 125 propagates through the core 210, and the other end. It is output from 202 to the second data communication device 300.
The signal light 325 from the second data communication device 300 is input to the other end 202 of the optical fiber cable 200, propagates through the core 210, and is output from one end 201 to the first data communication device 100.

As shown in FIG. 3, the first data communication device 100 is provided with an optical input / output unit 140 and an optical connector 141 attached to the optical input / output unit 140. Further, the second data communication device 300 is provided with an optical input / output unit 350 and an optical connector 351 attached to the optical input / output unit 350. An optical connector 230 provided at one end 201 of the optical fiber cable 200 connects to the optical connector 141. An optical connector 240 provided at the other end 202 of the optical fiber cable 200 connects to the optical connector 351. The optical input / output unit 140 guides the feeding light 112 to the clad 220, guides the signal light 125 to the core 210, and guides the signal light 325 to the receiving unit 130. The optical input / output unit 350 guides the feeding light 112 to the power receiving device 310, guides the signal light 125 to the receiving unit 330, and guides the signal light 325 to the core 210.
As described above, the optical fiber cable 200 has one end 201 connectable to the first data communication device 100 and the other end 202 connectable to the second data communication device 300 to transmit the feeding light 112. Further, in the present embodiment, the optical fiber cable 200 transmits the signal lights 125 and 325 in both directions.

As the semiconductor material constituting the semiconductor region that exerts the light-electricity conversion effect of the power feeding semiconductor laser 111 and the photoelectric conversion element 311, the same materials as those in the first embodiment are applied, and high light power feeding efficiency is realized. ..

As in the optical fiber cable 200B of the optical fiber feeding system 1B shown in FIG. 4, the optical fiber 260 for transmitting signal light and the optical fiber 270 for transmitting the feeding light may be provided separately. The optical fiber cable 200B may also be composed of a plurality of cables.

(2) Application of Means for Returning Part of Feeding Light Next, an optical fiber power feeding system to which means for returning a part of feeding light is applied will be described.

[Third Embodiment]
FIG. 5 is a configuration diagram showing an optical fiber power feeding system according to a third embodiment to which a means for returning a part of the feeding light is applied. In FIG. 5, the same components as those described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The optical fiber power supply system 1C of the third embodiment includes a power supply device 110C, a power receiving device 310C, and an optical fiber 250A. A load 401 that consumes the power supplied by the feeding light 112 is connected to the power receiving device 310C.

The power receiving device 310C includes a photoelectric conversion element 311 that converts the feeding light 112 into electric power, an optical return section 312 that returns a part of the input feeding light 112 as return light 313 to the outside of the device (optical fiber 250A), and an optical return section. It includes a return control unit 314 that controls 312 to change the magnitude of the return light 313, and a power monitoring unit 315 that monitors surplus power.

The optical return unit 312 is, for example, a dimming mirror that transmits a part of the received light while reflecting a part of the light. The dimming mirror may be configured to change the amount of reflection by electrically changing the optical characteristics, or may be configured to change the amount of reflection by changing the edge of the mirror in the laser spot by an actuator. Good. In addition, as the optical return unit 312, various methods may be adopted, such as a configuration in which one of the lasers split by using a beam splitter having a variable split ratio is returned to the optical fiber 250A.

The power monitoring unit 315 monitors the surplus power with respect to the load 401. The load 401 may include a power consuming component in the power receiving device 310C in addition to the configuration connected to the outside of the power receiving device 310C. The surplus power corresponds to the power obtained by subtracting the power consumption of the load 401 from the power obtained from the photoelectric conversion element 311. The power monitoring unit 315 detects, for example, the current and voltage output to the load 401, and calculates the surplus power. For example, since the input portion of the load 401 contains a capacitance component, the input voltage rises when the supply power is larger than the power consumption, while the input voltage falls when the supply power is smaller than the power consumption. The power monitoring unit 315 can calculate the surplus power from the input voltage of the load 401 and the power supplied to the load 401. Further, the power monitoring unit 315 may detect the temperature of the photoelectric conversion element 311 and add the detected temperature to the parameter to calculate the surplus power. Since the heat loss of the photoelectric conversion element 311 changes depending on the magnitude of the surplus power, the calculation accuracy of the surplus power can be improved by considering the temperature change of the photoelectric conversion element 311. In addition, the power monitoring unit 315 detects the intensity of the light divided at a very small constant ratio from the feed light 112, calculates the power and the supply power of the feed light 112 from the detected intensity, and subtracts the power consumption. The surplus power may be calculated. In addition, various methods may be applied to obtain the surplus power.

The return control unit 314 controls the optical return unit 312 so that the intensity of the return light 313 changes based on the magnitude of the surplus power that is the monitoring result of the power monitoring unit 315. The return control unit 314 may control the intensity of the return light 313 and the magnitude of the surplus power so as to have a predetermined relationship such as proportionality. Alternatively, the return control unit 314 may control the ratio of the return light 313 to the feed light 112 and the magnitude of the surplus power so as to have a predetermined relationship such as proportionality. In addition, the return control unit 314 controls the optical return unit 312 so that when the surplus power is in the target range, smaller than the target range, and larger than the target range can be distinguished by the return light 313. May be.

The power feeding device 110C includes a power feeding semiconductor laser 111, a separator 113 that separates the forward laser light and the reverse laser light, a light receiving element 114 that detects the separated return light 313, and a return light 313. A power control unit 115 that controls the output power of the power feeding semiconductor laser 111 based on the detected value is provided.

The separator 113 can adopt a configuration using a Faraday element used in an optical isolator or the like. The separator 113 branches the return light 313 and sends it to the light receiving element 114.

The light receiving element 114 is a semiconductor light receiving element such as a photodiode, and outputs a signal corresponding to the intensity of the return light 313 to the power control unit 115.

The power control unit 115 controls the power of the feeding light 112 sent to the power receiving device 310C so that the return light 313 becomes a predetermined value. As the predetermined value of the return light 313, a value that is a positive target value in which the surplus power in the power receiving device 310C is not excessive can be adopted. The predetermined value of the return light 313 may be determined according to the relationship between the return light 313 and the surplus power. For example, if the size of the return light 313 represents the magnitude of the surplus power, the target of the surplus power It corresponds to the magnitude of the return light 313 indicating the value. Further, if the ratio of the return light 313 to the feed light 112 represents the magnitude of the surplus power, it corresponds to the ratio of the return light 313 indicating the target value of the surplus power.

The power control unit 115 controls the power of the power feeding light 112 by increasing or decreasing the driving power input to the power feeding semiconductor laser 111. Alternatively, the power control unit 115 may control the power of the feeding light 112 sent to the power receiving device 310C by increasing or decreasing the split ratio of the beam splitter that divides the feeding light 112. When the feeding light 112 is divided and supplied from one power feeding device 110C to a plurality of power receiving devices 310C, the size of the feeding light 112 supplied to one power receiving device 310C can be changed by changing the division ratio. ..

FIG. 6 is a time chart showing an example of the operation of the optical fiber power feeding system of the third embodiment. FIG. 6 shows an example in which the size of the return light 313 is changed in the power receiving device 310C according to the magnitude of the surplus power, and power control is performed so that the size of the return light 313 converges to a predetermined value in the power feeding device 110C. Shown.

According to such control, when the power consumption of the load 401 is reduced and the surplus power of the power receiving device 310C is slightly increased, the return light 313 returned from the power receiving device 310C to the power feeding device 110C is increased. The power control unit 115 of the power feeding device 110C receives a change in the size of the return light 313 and lowers the power of the power feeding light 112 so that the return light 313 has the original size.

On the other hand, when the power consumption of the load 401 increases and the surplus power of the power receiving device 310C becomes slightly smaller, the size of the return light 313 returned from the power receiving device 310C to the power feeding device 110C becomes smaller. The power control unit 115 receives a change in the magnitude of the return light 313 and increases the power of the feed light 112 so that the return light 313 has the original size.

By such return control of the return light 313 and power control of the feed light 112, as shown in the time chart of FIG. 6, the intensity of the return light 313 is constant even if the power consumption of the load 401 changes significantly. The power of the feeding light 112 changes so as to be maintained at. Then, the surplus powers ΔW1 to ΔW3 are kept substantially constant due to the change in the power of the feeding light 112.

As described above, according to the optical fiber power feeding system 1C according to the third embodiment, the power feeding light 112 is supplied from the power feeding device 110C to the power receiving device 310C via the optical fiber 250A. In addition, the return light 313 indicating the magnitude of the surplus power is returned from the power receiving device 310C to the power feeding device 110C via the optical fiber 250A. Therefore, the power feeding light 112 can be diverted to transmit information on the surplus power from the power receiving device 310C to the power feeding device 110C. Further, due to the configuration in which the feeding light 112 and the return light 313 transmit a common transmission line of one optical fiber 250A, the transmission line of the feeding light 112 is diverted, and information on surplus power is transmitted from the power receiving device 310C to the power feeding device 110C. Can be transmitted. Then, the power feeding device 110C controls the intensity of the power feeding light 112 based on the information on the surplus power, so that power can be supplied according to the power consumption on the power receiving side.

Further, according to the optical fiber power feeding system 1C according to the third embodiment, since the optical return unit 312 is composed of a dimming mirror, it is possible to return the light 313 compactly and with low loss, and the power is supplied by the power feeding light 112. Suitable for systems that transmit by.

Further, according to the optical fiber power feeding system 1C according to the third embodiment, the return control unit 314 changes the size of the return light 313 according to the size of the surplus power. Therefore, the control process of the return control unit 314 is simplified, and for example, control that does not rely on software process can be easily realized. In this case, the return light 313 can be controlled even when the layer above the physical layer is not moving on the power receiving side, such as when the power supply is started.

Further, according to the optical fiber power feeding system 1C according to the third embodiment, the power control unit 115 of the power feeding device 110C uses the feeding light 112 so that the return light 313 converges to a predetermined value representing a positive surplus power that is not excessive. Control the power of. Therefore, in the power receiving device 310C, it is possible to suppress the shortage of electric power, and it is possible to generate the return light 313 from the surplus.

In the third embodiment, an example in which the feed light 112 and the return light 313 are transmitted via a common transmission line is shown, but different optical fibers or different transmission lines of the common optical fiber (core and first). It may be transmitted via a clad or the like. Further, in the third embodiment, the configuration in which the return light 313 indicates the magnitude of the surplus power is shown, but a configuration in which the return light 313 is modulated to represent the magnitude of the surplus power may be applied.

The power control of the feeding light 112 based on the return light 313 shown in the third embodiment may be applied to the system configuration of FIGS. 2 and 4. Specifically, the power feeding device 110 of FIGS. 2 and 4 is replaced with the power receiving device 110C of the third embodiment, and the power receiving device 310 of FIGS. 2 and 4 is replaced with the power receiving device 310C of the third embodiment. In addition, as the transmission path of the feed light 112 and the return light 313, the clad 220 of the optical fiber 250 of FIG. 2 or the optical fiber 270 of FIG. 4 may be adopted.

Although the embodiments of the present disclosure have been described above, this embodiment is shown as an example, and can be implemented in various other embodiments, and components are omitted as long as the gist of the invention is not deviated. , Can be replaced or changed. For example, the load to which power is supplied from the power receiving device is not limited to the communication device or the radio device, and may be any device. The configuration of the detection unit that detects the magnitude of electric power is not limited to the specific example shown in the embodiment, and various circuit configurations may be adopted.

1A Optical fiber power supply system 1 Optical fiber power supply system 1B Optical fiber power supply system 1C Optical fiber power supply system 100 First data communication device 110 Power supply device 110C Power supply device 111 Semiconductor laser for power supply (laser oscillator)
112 Feed light 113 Separator 114 Light receiving element 115 Power control unit 120 Transmitter 125 Signal light 130 Receiver 140 Optical input / output 141 Optical connector 200A Optical fiber cable 200 Optical fiber cable 200B Optical fiber cable 210 Core 220 Clad 250A Optical fiber 250 Optical fiber 260 Optical fiber 270 Optical fiber 300 Second data communication device 310 Power receiving device 310C Power receiving device 311 Photoelectric conversion element 312 Optical return unit 313 Return light 314 Return control unit 315 Power monitoring unit 320 Transmission unit 325 Signal light 330 Reception unit 350 Optical input / output unit 351 Optical connector 401 Load ΔW1 to ΔW3 Surplus power

Claims (7)

A photoelectric conversion element that converts the feed light input from outside the device into electric power,
The power monitoring unit that monitors surplus power and
An optical return unit that outputs a part of the feed light as return light to the outside of the device.
A return control unit that controls the optical return unit based on the monitoring result of the power monitoring unit,
A power receiving device equipped with. The optical return unit is a dimming mirror that reflects a part of the feeding light.
The power receiving device according to claim 1. The return control unit changes the magnitude of the return light according to the magnitude of the surplus power.
The power receiving device according to claim 1 or 2. A laser oscillator that converts power into feed light and outputs it to the outside of the device,
A light receiving element that receives the return light returned from outside the device,
A power control unit that controls the power of the feed light based on the return light,
Power supply device equipped with. The power control unit
The power of the feed light is controlled so that the return light converges to a predetermined value representing positive surplus power.
The power supply device according to claim 4. The power receiving device according to any one of claims 1 to 3,
The power supply device according to claim 4 or 5.
The optical fiber that transmits the feed light and
The optical fiber that transmits the return light and
Fiber optic power supply system with. The feed light and the return light are transmitted through the same transmission line of one optical fiber.
The optical fiber power supply system according to claim 6.

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