CN112994743A

CN112994743A - Remote communication device shared by direct current and carrier wave

Info

Publication number: CN112994743A
Application number: CN201911298264.9A
Authority: CN
Inventors: 吴乐南; 史亚光
Original assignee: SUZHOU EASTERNWONDER INFORMATION TECHNOLOGY CO LTD
Current assignee: Nanjing Jinxin Information Technology Co.,Ltd.
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2021-06-18
Anticipated expiration: 2039-12-17
Also published as: CN112994743B

Abstract

The present invention relates to a direct current and carrier shared remote communication device. The direct current carrier communication module comprises an isolation module, a power supply module, a Digital Signal Processor (DSP), a modulation shaping module, a power amplification module, a first coupling module, a signal amplification module, a frequency selection shaping module and a second coupling module. The device is used for remotely transmitting high-speed data by utilizing a common double-wire, and simultaneously supplying direct current to a remote sensor and actuator node for constructing a remote high-speed communication link of the powerless area Internet of things.

Description

Remote communication device shared by direct current and carrier wave

Technical Field

The present invention relates to a composite system of remote power feeding and communication, and more particularly, to a remote communication device sharing dc and carrier.

Background

1. Oil gas long-distance pipeline:

pipeline transportation is the primary mode of transportation for crude and product oils. 95% of the total length of the pipeline is buried underground, and the ground can still be cultivated, so that the pipeline is more convenient for turning over mountains and crossing over mountains and rivers and lakes. China has put pipelines, railways, water ways, roads and air traffic into parallel 5 main transportation modes.

According to the Chinese oil and gas pipeline market research and investment strategy report (2019), which is issued by standing log information consultation, the following are shown: the oil and gas long-distance transmission pipeline is used as one of main transportation carriers of crude oil, product oil and natural gas, plays an important role in national infrastructure, and has the advantages of low leakage, low pollution, high efficiency and the like.

At present, the total amount of the oil and gas long-distance transmission pipelines in service is about 3,800, and the total length is 196.13 kilometers, wherein the natural gas pipeline accounts for about 64.94 percent, and is the most important pipeline; the crude oil and the finished oil pipelines respectively account for 18.52 percent and 12.68 percent. By 2015, the total mileage of the oil-gas long-distance pipeline in China is 10.87 kilometers, which is similar to the global oil-gas pipeline pattern, the storage pipeline occupation ratio is the highest natural gas pipeline, and the total length is about 6.4 kilometers at present. According to the planning, the mileage of oil and gas long-distance pipelines in China reaches 16.9 kilometers by the end of 2020 years; according to the statistical caliber of the national statistical bureau, the total mileage at that time is 1.555 times of that in 2015 years, and the newly increased mileage in 5 years is 6.03 kilometres.

2. Pipeline internet of things:

because the distance of the oil and gas pipeline is long, the environment is complex, the amount of the test object is large, and the oil and gas pipeline often passes through an unmanned area, the online monitoring (such as the sedimentation, deformation and displacement of the pipeline, the temperature, pressure and flow of fluid in the pipeline and the like) and the monitoring (such as the state of a valve) of the oil and gas pipeline are easily realized by using the technology of the internet of things, and the wireless sensor network (wireless sensor network for short, WSN) is convenient to install and flexible to arrange and becomes the first choice. Provided of course that problems with power supply and distance of communication can be secured.

However, this requirement is often not met for long oil and gas pipelines. For this reason, the general solution can utilize the "short message" function of the "beidou" satellite when the mobile communication public network (general packet radio service GPRS or narrowband internet of things NB-IoT) has poor signals or the private network (for example, WiFi, ZigBee or LoRa) has insufficient coverage distance; when no power is supplied, the solar panel and the storage battery are adopted firstly. This not only can increase the input of monitoring node by a wide margin, can not guarantee to solve the problem reliably moreover, because the geographical span of oil gas long-distance transmission pipeline is very big, such as overcast and rainy season in south, the sandstorm in north all can influence or even damage solar cell panel, and it is also not impossible to the artificial theft of solar power system in the rare area of people's trace.

Therefore, for typical chained internet of things such as oil and gas pipelines, a fiber/copper composite cable is used to run along the pipeline, wherein the fiber transmits data, and the copper wire transmits electric energy, which is a feasible and ideal choice for both communication and power supply, and is a typical practice of many city "pipe corridors". Only for long distance oil and gas transmission pipelines, the investment is definitely higher.

3. Wired energy-carrying communication:

to reduce the cost of communication and power for remote pipeline automation, the number of transmission cables must be minimized. For this reason, it is desirable to be able to transmit data simultaneously over a power line or to carry energy simultaneously over a communications cable.

1) For the former, i.e. data is transmitted simultaneously on the power line, a power carrier modem product has been available, namely a 'power modem' which enters a home. However, there are two problems with long oil and gas pipelines:

the power line is a 220V Alternating Current (AC), although the AC is calculated to be low voltage on a power line, the AC is strong current in the automation field, and is laid together with flammable and explosive oil and gas pipelines, so that potential safety hazards are certainly caused;

and secondly, Direct Current (DC) is needed from the sensor to the actuator along each monitoring and monitoring node of the pipeline, and if alternating current is used for supplying power, each node is required to be rectified and converted into proper direct current voltage, so that the cost and the transmission loss are increased without end.

2) For the latter, namely, the communication cable is used for completing feeding simultaneously to realize the 'wired communication process carrying energy', theoretically at least one wire is needed, and then the ground is used for forming a loop, but the good grounding of all points along the line cannot be guaranteed, and the loss is large, so in practice, at least two wires are needed.

In fact, in data communication, computer networks and distributed industrial control systems, it is often necessary to use serial communication (serial bus, serial interface) to achieve data exchange. Among them, the technical products capable of implementing telecommunication (transmission rate is inversely proportional to transmission distance) and power supply mainly include:

RS-485: the standard serial port RS-232 of the PC is developed, the history is the longest, and the application is the most extensive. The differential signal negative logic (-2V to-6V for "1" and +2V to +6V for "0") is realized by using a shielded twisted pair. At a rate of 100kbps, the point-to-point communication distance is about 1200 meters, but 4 wires are required for power. The maximum bus voltage is 5V;

(II) M-BUS: the meter is an instrument bus standard introduced by Europe and specially designed for an automatic meter reading system, and is incorporated into an industry standard by the national ministry of construction. The system adopts a common RV1.5 twisted-pair line without polarity, has the advantages of bus self-power supply, no topological requirement on wiring, strong anti-interference capability, multiple relay stages, multiple stages with terminals, simplicity, reliability and the like, and is the best bus standard applied to the current automatic meter reading system. The M-BUS system adopts half-duplex asynchronous communication, the signal level is a downlink voltage and uplink current loop, and the transmission rate is as follows: 300 ~ 9600bps, point-to-point communication distance is about 1000 meters. The maximum bus voltage is 35V;

③ PowerBus: the bus technology is the only bus technology capable of supporting high-power load power supply and high-speed communication in the industry, and is a fire-fighting bus technology from mature applications for many years. Any cable can be adopted, wiring is non-polar, the signal level is a downlink voltage and an uplink current loop, the highest transmission rate is 9600bps, and the point-to-point maximum communication distance can reach 3000 meters. The maximum bus voltage is 48V.

In conclusion, the M-BUS and the PowerBus buses with double-line power supply can be realized, the highest transmission rate is only 9600bps, and the point-to-point maximum communication distance does not exceed 3000 meters. This can certainly meet the application scenarios of their original automatic meter reading and fire engineering, but for many tens, hundreds or even thousands of kilometers of oil and gas long-distance pipelines, not only the maximum point-to-point communication distance is very far, but also the transmission rate is difficult to adapt to special requirements, such as video monitoring. The reason for this is mainly that the dc level modulation (positive and negative voltage or current loop) technique continued from RS-485 is limited, and although it is favorable for two-wire system power supply, it greatly affects the improvement of point-to-point transmission rate and transmission distance.

Disclosure of Invention

Based on this, a remote communication device sharing direct current and carrier waves is provided. The device is used for remotely transmitting high-speed data by utilizing a common double-wire, and simultaneously supplying direct current to a remote sensor and actuator node for constructing a remote high-speed communication link of the powerless area Internet of things.

A kind of direct current shares the remote communicator with carrier, including a plurality of direct current carrier communication modules, the said direct current carrier communication module includes isolating the module, power module, digital signal processor DSP, modulates the shaping module, power amplification module, the first coupling module, signal amplification module, frequency-selecting shaping module and second coupling module, wherein:

the power supply module is connected with the isolation module, the isolation module is connected with the direct current power line, and the isolation module is used for isolating the high-frequency carrier signal on the direct current power line from the power supply module;

the signal output end of the digital signal processor DSP is connected with the modulation shaping module, the modulation shaping module is connected with the power amplification module, the power amplification module is connected with the first coupling module, the first coupling module is connected with a direct current power line,

the digital signal processor DSP is used for generating an MPPSK modulation signal, the MPPSK modulation signal is firstly filtered and shaped through a modulation and shaping module, then power amplification is carried out through the power amplification module, and then the MPPSK modulation signal is transmitted into a direct current power line through the first coupling module;

the signal input end of the digital signal processor DSP is connected with the signal amplification module, the signal amplification module is connected with the frequency selection shaping module, the frequency selection shaping module is connected with the second coupling module, the second coupling module is connected with a direct current power line,

the second coupling module is used for receiving MPPSK modulation signals transmitted on a direct current power line, the MPPSK modulation signals are filtered out of band noise through the frequency-selecting shaping module, amplified to an amplitude range suitable for an analog-to-digital converter built in the digital signal processor DSP through the signal amplification module, and demodulated through the digital signal processor DSP.

The device of the invention generates high-frequency carrier signals through the DSP and the corresponding module and sends the high-frequency carrier signals to the DC power line, and meanwhile, the device of the invention can receive and demodulate the high-frequency carrier signals transmitted by the DC power line through the DSP and the corresponding module. Moreover, the power module can utilize direct current on the direct current power line to supply power for the whole device and other external equipment.

In one embodiment, the isolation module isolates a high frequency carrier signal on the dc power line from the power module through a reactive element.

In one embodiment, the reactive element is an inductor.

In one embodiment, the modulation shaping module, the power amplification module and the first coupling module form a first peripheral circuit of the digital signal processor DSP, which is isolated from direct current by providing a capacitor C10.

In one embodiment, the second coupling module, the frequency-selective shaping module and the signal amplification module form a second peripheral circuit of the digital signal processor DSP, and the second peripheral circuit is isolated from direct current by providing a capacitor C11.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic block diagram of a dc and carrier sharing telecommunications device according to an embodiment of the present invention.

Fig. 2 is a circuit diagram of an isolation module and a power module according to an embodiment of the present invention, wherein the power module is a dc power supply, and the isolation module isolates a high-frequency carrier signal from the dc power supply by providing an inductor.

Fig. 3 is a circuit diagram of a first peripheral circuit formed by the modulation shaping module, the power amplifying module and the first coupling module according to an embodiment of the present invention.

Fig. 4 is a circuit diagram of a second peripheral circuit formed by the second coupling module, the frequency-selective shaping module and the signal amplifying module according to the embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1, an embodiment of the present invention provides a dc and carrier shared telecommunication apparatus. The direct current carrier communication module comprises an isolation module, a power supply module, a Digital Signal Processor (DSP), a modulation shaping module, a power amplification module, a first coupling module, a signal amplification module, a frequency selection shaping module and a second coupling module, wherein:

It should be noted that the digital signal processor DSP is configured to generate an MPPSK modulated signal and demodulate the received MPPSK modulated signal. MPPSK is also referred to as M-ray Position Phase Shift Keying (M-ray Position Phase Shift Keying). For a specific modulation and demodulation method, refer to chinese patent ZL 200710025202.1. The patent document discloses a multi-element position Phase Shift Keying modulation and demodulation method, and concretely, the method is based on a unified Binary Phase modulation and demodulation method, adopts M-system information symbols to directly control the position of a sinusoidal carrier Phase jump moment in each symbol period, and can insert a certain guard interval to realize the modulation of M-element signals, thereby realizing higher information rate transmission under the same symbol rate of Extended Binary Phase Shift Keying (EBPSK) modulation, and the occupied bandwidth is almost unchanged; the demodulator is realized by adopting a phase-locked loop, and the position of phase jump can be effectively judged by utilizing the output of the phase discriminator, so that the demodulation of M-system symbols is realized. The invention has the advantages of simple realization, excellent performance and more convenient online adjustment of the transmission code rate and the transmission distance.

Specifically, any position of a long transmission pipeline with a power supply can be used as a starting point of the direct current and carrier shared remote communication device, two arbitrary wires carry direct current energy and internet of things data to extend along with the pipeline, the two wires are not called direct current power lines (DC), and each internet of things node along the pipeline gets electricity from the direct current power lines through the device (i.e., each direct current carrier communication module) of the invention and receives and transmits the data, as shown in fig. 1.

Specifically, the power module may employ a DC power supply in the prior art. The DC power supply can supply power for power consumption components on the device and can also supply power for other external equipment of the nodes of the Internet of things. That is, other external devices of the internet of things can be connected with the DC power supply, and corresponding interfaces can be arranged on the DC power supply to connect with other external devices.

In this embodiment, the isolation module isolates the high-frequency carrier signal on the dc power line from the power module through the reactance element. Specifically, the reactance element is an inductor. As shown in fig. 2, the isolation module includes: the inductor comprises an inductor L6, a resistor R39, a capacitor C48 and a capacitor C12, wherein a first end of the inductor L6 is connected with a TxRx pin of a power supply module, and a second end of the inductor L6 is connected with a direct-current power line. A first terminal of the capacitor C48 is connected to the SGND pin of the power supply module, and a second terminal of the capacitor C48 is connected to a first terminal of the capacitor C48 and a first terminal of the capacitor C12, respectively. The second end of the capacitor C48 and the second end of the capacitor C12 are respectively connected to the second end of the inductor L6. The first end of the capacitor C48 and the first end of the capacitor C12 are connected with the GND end. When the isolation module works, a high-frequency carrier signal on a direct-current power line is isolated from the power supply module through the inductor L6. Meanwhile, the power module can get electricity from the direct current power line through the isolation module.

As shown in fig. 3, in this embodiment, the modulation shaping module, the power amplifying module and the first coupling module form a first peripheral circuit of the digital signal processor DSP. The first peripheral circuit includes: the circuit comprises a resistor R11, a capacitor C49, a capacitor C13, a diode D1, a resistor R13, an SP8M3 chip, a resistor R10, a resistor R12 and a capacitor C10. A first end of the capacitor C10 is connected to a TxRx pin of the DSP for outputting a signal, a second end of the capacitor C10 is connected to a node between the resistor R10 and the resistor R12, the resistors R10 are respectively connected to two nD pins of the SP8M3 chip, that is, the 8 th and 7 th pins in fig. 3, the resistor R12 is respectively connected to two pD pins of the SP8M3 chip, that is, the 5 th and 6 th pins in fig. 3, a first end of the resistor R13 is connected to a pS pin of the SP8M3 chip, a second end of the resistor R13 is connected to a pG pin of the SP8M3 chip, an anode of the diode D1 is connected to a pG pin of the SP8M3 chip, a cathode of the diode D1 is connected to a pS pin of the SP8M3 chip, one end of the capacitor C6 is connected to a pG pin of the SP8M3 chip, and the other end of the capacitor C6327 is connected to a pin of the SP8M3 chip. The pS pin of the SP8M3 chip is connected to the dc power line. The first end of the resistor R11 is connected with the nG pin of the SP8M3 chip, and the other end of the resistor R11 is connected with a direct current power line. One end of the capacitor C49 is connected with the pS pin of the SP8M3 chip, and the other end of the capacitor C49 is connected with the GND terminal.

The first peripheral circuit is used for properly filtering and shaping the MPPSK modulation signal which is output by the digital signal processor DSP and is approximately square wave into approximate sine wave, amplifying the approximate sine wave to certain power and then transmitting the amplified approximate sine wave to a direct current power line through the coupling module for transmission.

As shown in fig. 4, in this embodiment, the second coupling module, the frequency-selective shaping module and the signal amplifying module form a second peripheral circuit of the digital signal processor DSP. The second peripheral circuit includes: the circuit comprises a resistor R40, a resistor R14, a resistor R15, a first OPA353 chip, a resistor R24, a resistor R20, a resistor R17, a resistor R18, a second OPA353 chip, a diode D2, a diode D3, a capacitor C40, a resistor R23, a resistor R19 and a capacitor C11. A first end of the capacitor C11 is connected to a TxRx pin of the DSP for receiving signals, a second end of the capacitor C11 is connected to a first end of the resistor R19, a second end of the resistor R19 is connected to an IN-pin of the second OPA353 chip and a first end of the resistor R23, a second end of the resistor R23 is connected to an anode of the diode D2, a cathode of the diode D2 is connected to an OUT pin of the second OPA353 chip, a cathode of the diode D3 is connected to a node between the resistor R23 and the diode D2, an anode of the diode D3 is connected to an OUT pin of the second OPA353 chip, one end of the capacitor C40 is connected to a node between the resistor R23 and the diode D2, the other end of the capacitor C40 is connected to an OUT pin of the second OPA chip, the resistor R17 is connected to the resistor R18 IN series, and a node between R17 and the resistor R18 is connected to an IN + pin of the second OPA chip. The first end of the resistor R20 is connected with the OUT pin of the second OPA353 chip, the second end of the resistor R20 is connected with the IN-pin of the first OPA353 chip, one end of the resistor R24 is connected with the IN-pin of the first OPA353 chip, the other end of the resistor R24 is connected with the OUT pin of the first OPA353 chip, the resistor R14 is connected with the resistor R15 IN series, a node between the resistor R14 and the resistor R15 is connected with the IN + pin of the first OPA353 chip, the first end of the resistor R40 is connected with the OUT pin of the first OPA353 chip, and the second end of the resistor R40 is connected with a direct-current power line.

The second peripheral circuit is used for filtering out-of-band noise of the MPPSK modulation signal received by the coupling module and amplifying the MPPSK modulation signal to an amplitude range suitable for an analog-to-digital converter (ADC) built in a Digital Signal Processor (DSP).

The beneficial effects of the invention are verified by experiments below.

The digital signal processor DSP in fig. 1 adopts a domestic fixed-point digital signal processor chip STM320F2810, is limited by its processing capability, the frequency of the high-frequency carrier is designed to be 270kHz, and the transmission code rate of the obtained MPPSK modulation signal on the dc power line is 30 kbps. During testing, a 300-meter lead is adopted, a 10dB attenuator is added, a 12V direct-current power supply is adopted, the signal waveform is not distorted, and data transmission is free of error codes. It was found that the transmission distance is mainly limited by the resistance and voltage drop of the power line, and the margin of data transmission capability is still large. If a thicker wire, a higher voltage (e.g., 36V or 48V), and a lower power consumption digital signal processor DSP or modem chip is selected, a higher transmission rate and a greater transmission distance are indeed available for transmitting the compressed video stream.

As can be seen from the above analysis, the present invention has the following advantageous effects as compared with the prior art.

(1) The transmission distance is far and the speed is high:

the high-frequency carrier modulation is adopted, the baseband code type transmission utilizing the direct current level is changed into frequency band transmission, the communication effect can be greatly improved, and on one hand, the communication effect is ensured by the basic principle of communication; on the other hand, the cable is buried underground along with the oil and gas pipeline, and the interference to the outside radiation is much smaller than the interference of the conventional exposed open line.

(2) The two-wire carrier carries energy communication:

the high-frequency carrier communication is realized, meanwhile, the same pair of cables can be used for supplying power to the Internet of things node, and high-speed energy-carrying communication is realized on a high-frequency carrier line.

3) The requirement on cables is not high:

it is not required to be a twisted pair or a shielded wire, and any conductive wire may be used. Of course, the thicker the wire diameter, the smaller the resistance, and the longer the feeding distance.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A remote communication device shared by direct current and carrier waves is characterized by comprising a plurality of direct current carrier communication modules, wherein each direct current carrier communication module comprises an isolation module, a power supply module, a Digital Signal Processor (DSP), a modulation shaping module, a power amplification module, a first coupling module, a signal amplification module, a frequency selection shaping module and a second coupling module, and the frequency selection shaping module comprises:

2. The dc-carrier shared telecommunications device of claim 1, wherein the isolation module isolates the high frequency carrier signal on the dc power line from the power module through a reactive element.

3. The dc-carrier shared telecommunication device according to claim 2, wherein said reactive element is an inductor.

4. The dc-carrier shared telecommunication device according to claim 1, wherein the modulation shaping module, the power amplification module and the first coupling module form a first peripheral circuit of the digital signal processor DSP, the first peripheral circuit isolating dc by providing a capacitor C10.

5. The dc-carrier shared telecommunication device according to claim 1, wherein the second coupling module, the frequency-selective shaping module and the signal amplification module form a second peripheral circuit of the digital signal processor DSP, and the second peripheral circuit isolates dc by providing a capacitor C11.