Power line communication device and system

Abstract

The embodiment of the invention discloses a power line communication device and system, a power line communication signal receiving and transmitting circuit and a coupling circuit are arranged in the power line communication device, and the power line communication signal receiving and transmitting circuit is configured to receive and / or transmit power line communication signals. The coupling circuit is configured to couple the power line communication circuit with the target power line in an antenna coupling mode, and the coupling circuit is connected between the power line communication signal receiving and transmitting circuit and the target power line. Therefore, the signal transmission between the power line communication devices is carried out in an antenna coupling mode, the voltage difference between the ground wire and the power line can be prevented from being measured, an inductor can be prevented from being added for isolation, the structure of the system is simplified, and the cost of power communication is reduced.

Description

Technical Field

[0001] The present invention relates to the field of power line carrier communication, and in particular, to a power line communication device and system. Background Art

[0002] Power line carrier communication technology is a communication method that uses the existing power lines as a transmission medium to achieve data transfer and information exchange. By loading high-frequency signals onto the power lines, it utilizes the characteristics of high mechanical strength and good reliability of the power transmission lines to achieve data transmission. Power line carrier communication technology has the advantages of long transmission distance, stable signal, and strong flexibility.

[0003] Collecting the voltage difference between the power line and the ground line is a conventional method for power line carrier communication. However, due to the presence of filter capacitors in the system nodes, the filter capacitors play a role in filtering high-frequency noise and stabilizing the system voltage, which will greatly reduce the AC voltage difference between the two lines. Therefore, when collecting the AC voltage difference, an inductor is required to isolate the communication node from the original system, otherwise the filter capacitors in the system nodes will greatly reduce the signal amplitude on the two lines. Usually, two isolation methods are adopted: single-ended connection and double-ended connection, specifically by connecting the inductor to one side or both sides of the system node.

[0004] However, adding an inductor to the communication system will cause a significant increase in cost. Especially when the current of the system node is very large, the cost of an inductor that can meet the large current is very high. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a power line communication device and system. By using the antenna coupling method for signal transmission between power line communication devices, it is possible to avoid measuring the voltage difference between the ground line and the power line, thereby avoiding adding an inductor for isolation, and further simplifying the structure of the system and reducing the cost of power communication.

[0006] In a first aspect, an embodiment of the present invention provides a power line communication device, which includes:

[0007] A power line communication signal transceiver circuit, configured to receive and / or transmit power line communication signals;

[0008] A coupling circuit, connected between the power line communication signal transceiver circuit and the target power line, and configured to couple the power line communication signal transceiver circuit with the target power line in an antenna coupling manner, where the target power line is one of the power line or the ground line.

[0009] In a second aspect, an embodiment of the present invention provides a power line communication system, which includes:

[0010] A ground line;

[0011] Power supply line;

[0012] A plurality of power line communication devices as described in the first aspect.

[0013] The technical solution of the embodiment of the present invention is to provide a power line communication signal transceiver circuit and a coupling circuit in a power line communication device, wherein the power line communication signal transceiver circuit is configured to receive and / or transmit power line communication signals, and the coupling circuit is configured to couple the power line communication circuit to the target power line in an antenna coupling manner, wherein the coupling circuit is connected between the power line communication signal transceiver circuit and the target power line. Thus, by means of antenna coupling for signal transmission between power line communication devices, the voltage difference between the measurement ground wire and the power supply line can be avoided, thereby avoiding the addition of inductors for isolation, further simplifying the system structure, and reducing the cost of power communication. Description of the Drawings

[0014] Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features and advantages of the present invention will become clearer. In the drawings:

[0015] Figure 1 is a schematic diagram of a power line communication system of the prior art;

[0016] Figure 2 is a schematic diagram of another power line communication system of the prior art;

[0017] Figure 3 is a schematic diagram of the power line communication system of the embodiment of the present invention;

[0018] Figure 4 is a schematic diagram of the power line communication device of the embodiment of the present invention;

[0019] Figure 5 is a circuit diagram of the power line communication device of the embodiment of the present invention;

[0020] Figure 6 is a circuit diagram of the power line communication device of the embodiment of the present invention. Detailed Embodiments

[0021] The following description is based on embodiments of the present application, but the present application is not limited to these embodiments. In the following detailed description of the present application, some specific details are described in detail. Those skilled in the art can fully understand the present application without the description of these details. To avoid obscuring the essence of the present application, well-known methods, processes, procedures, elements and circuits are not described in detail.

[0022] In addition, those of ordinary skill in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0023] Meanwhile, it should be understood that in the following description, "circuit" refers to a conductive loop formed by at least one component or sub-circuit through electrical connection or electromagnetic connection. When it is said that a component or circuit "is connected to" another component or that a component / circuit "is connected between" two nodes, it may be directly coupled or connected to another component or there may be intermediate components. The connection between components can be physical, logical, or a combination thereof. On the contrary, when it is said that a component "is directly coupled to" or "is directly connected to" another component, it means that there are no intermediate components between the two.

[0024] Unless the context clearly requires otherwise, words such as "including" and "comprising" in the entire application document should be interpreted as having an inclusive meaning rather than an exclusive or exhaustive meaning; that is, it is the meaning of "including but not limited to".

[0025] In the description of this application, it should be understood that terms such as "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0026] Power Line Carrier Communication (PLC) technology is a technology that uses existing power lines as a transmission medium to transmit analog or digital signals at high speed through carrier mode. It is a unique communication method in the power system, with many advantages such as no need to re-erect a network, low cost, relatively fast transmission speed, wide coverage area, convenient access, and multiple users can share broadband.

[0027] The working principle of power line carrier communication technology is to modulate the original signal into a high-frequency signal and load it onto the power line for transmission. At the receiving end, the modulated signal is taken out through a filter and demodulated to obtain the original signal, thereby realizing information transmission. The transmission distance of power line carrier communication is affected by various factors. For example, the transmission distance of overhead power lines is generally less than 10 Km, and the transmission distance of underground power cables is less than 2 Km.

[0028] Currently, power line carrier communication technology is mainly applied to various fields such as power meter reading, intelligent building management, remote monitoring and maintenance, and agricultural monitoring. With the expansion of the Internet of Things ecosystem, various devices in the smart home system need to be interconnected. Power line carrier communication technology has become a low-cost and highly reliable solution suitable for a wide range of social infrastructure and daily life energy management.

[0029] Figure 1 and Figure 2 are schematic diagrams of a prior art power line communication system, as shown in Figure 1 and Figure 2 shown. The power line communication system includes a plurality of power line communication devices 1a, 1b, 1c, 1d, a ground wire 2, a power line 3, a plurality of system nodes 4a, 4b, 4c, 4d, and a coupling capacitor C1. It should be noted that only four power line communication devices 1a, 1b, 1c, 1d and four system nodes 4a, 4b, 4c, 4d are shown in the figure, and the remaining power line communication devices are represented by ellipses in the figure. The system nodes are electrical equipment in the power line communication system, and each system node is connected to a complete communication network. For example, when the power line communication system is a smart home system, the system nodes can be electrical equipment such as smart control devices and lighting devices.

[0030] Among them, the ground wire 2 is used to conduct current into the ground to prevent electric shock accidents when a fault occurs in the power line communication system. In the power line communication system, the ground wire also plays a role in providing a common zero potential point for the circuit signal loop, which helps to ensure the stable transmission of signals. The power line 3 can both transmit electrical energy and be used as a data transmission channel in the power line communication system. In the embodiment of the present invention, the power line 3 includes both a neutral wire and a live wire. Among them, the neutral wire is not charged and is specifically used to ensure that the current can form a complete loop, and the live wire carries high-voltage current and is specifically used to provide electrical energy for each system node.

[0031] The power line communication device is used to implement communication functions between each communication node. Specifically, one power line communication device sends a signal, and one or more other power line communication devices receive the signal to achieve information interaction between at least two power line communication devices. Among them, the power line communication device is communicatively connected to the ground wire 2 and the power line 3, and communication is achieved through a differential signal obtained by measuring the AC signal voltage difference between the ground wire 2 and the power line 3. The differential signal is a signal transmission method that uses a pair of wires to transmit signals, where the signal transmitted by one wire is equal in amplitude but opposite in phase to the signal transmitted by the other wire. By measuring the AC signal voltage difference between the ground wire 2 and the power line 3, the power line communication signal is determined.

[0032] However, due to the presence of filter capacitors for filtering noise and stabilizing voltage in the system node, for example, in Figure 1The system node 4a includes a filtering capacitor C2. Since the carrier signal is an AC signal, the filtering capacitor will affect the measurement of the AC signal voltage difference between the ground wire and the power line. Based on the above defects, when measuring the AC signal voltage difference between the ground wire 2 and the power line 3, the prior art generally needs to isolate the system node from the ground wire 2 and the power line 3, so as to accurately measure the voltage difference between the ground wire 2 and the power line 3. Among them, the coupling capacitor C1 is used to isolate multiple power supply voltages when the system has multiple power supply voltages.

[0033] In the prior art, there are two ways to isolate the system node. One way is as Figure 1 shown, inductors are arranged on both sides of each system node to isolate the filtering capacitor in the system node from the ground wire 2 and the power line 3; the other way is as Figure 2 shown, an inductor is arranged on one side of each system node to isolate the filtering capacitor in the system node from the ground wire 2 and the power line 3.

[0034] However, since the current inside the system node is large, when setting the inductor connected to the system node, an inductor that can withstand the current inside the system node needs to be set. In the current market, inductors that can withstand large currents generally have a relatively large volume, and thus the cost is relatively high. And a power line communication system usually includes multiple system nodes. Therefore, in order to measure the AC signal voltage difference between the power line and the ground wire, a relatively large cost needs to be paid. Therefore, a solution is currently needed to reduce the cost of the power line communication system.

[0035] Based on the defects of the current power line communication system, the embodiments of the present invention connect each power line communication device by means of antenna coupling and transmit signals, thereby avoiding measuring the voltage difference between the ground wire and the power line and realizing the reduction of the cost of the power line communication system.

[0036] Figure 3 is a schematic diagram of the power line communication system according to the embodiments of the present invention. As Figure 3 shown, the power line communication system includes multiple power line communication devices (1a, 1b, 1c, 1d), a ground wire 2, a power line 3, and multiple system nodes (4a, 4b, 4c, 4d) and a coupling capacitor C1.

[0037] Specifically, a power line communication system includes several power line communication devices. It should be noted that only four power line communication devices 1a, 1b, 1c, and 1d are schematically shown in the figure, and the remaining power line communication devices are represented by ellipses in the figure. The power line communication devices receive various data signals, such as audio, video, control instructions, etc., then modulate the data signals onto a high-frequency carrier, and transmit the carrier signal through the power line to achieve remote transmission and sharing of multiple power line carrier data, enabling each component of the power system to exchange information in real time, and can be applied to multiple fields such as remote monitoring, automation control, smart home, and office network.

[0038] The power line communication system further includes several system nodes. It should be noted that Figure 3 only four system nodes 4a, 4b, 4c, and 4d are shown in the figure, and the remaining system nodes are represented by ellipses in the figure. The system node is a node that connects different components in the system, enabling information or electric energy to be transmitted between these components to achieve the functions of the power line communication system.

[0039] The coupling capacitor C1 is used to isolate multiple power supply voltages when there are multiple power supply voltages in the power line carrier communication system. Specifically, the number of coupling capacitors C1 is determined by the number of power supply voltages in the power line carrier communication system. For example, if the power line carrier communication system includes 5 power supply voltages, then 4 coupling capacitors need to be set to isolate multiple power supply voltages.

[0040] In the embodiment of the present invention, instead of using the traditional method of measuring between the ground wire 2 and the power supply wire 3 to achieve communication, a method similar to antenna coupling is adopted. By coupling each power line communication device to a power line, the transmission of radio frequency signals is achieved through a power line, thereby enabling communication between each power line communication device. Among them, the power line only needs to be a power line capable of signal transmission. Specifically, it can be either a ground wire or a power supply wire. Since this method avoids the measurement of voltage difference, there is no need to set an inductor to isolate the system node, and the power supply end of the system node is directly connected to the power supply wire and the ground wire.

[0041] Specifically, in the embodiment of the present invention, the ground wire 2 or the power supply wire 3 is used as the target power line, and the target power line is specifically an antenna shared by each power line communication device, and then signal transmission is performed on the target power line. As Figure 3As shown, each power line communication device is connected to the ground wire. That is, in the embodiment of the present invention, the ground wire 2 is used as a common antenna to achieve signal transmission. It should be noted that, in the embodiment of the present invention, the ground wire 2 is taken as an example of the antenna for illustration. The power supply line 3 can also be used as the common antenna of each power line communication device. The specific connection method of each power line communication device is the same as that of the ground wire 2, and the principle is similar to that of the ground wire 2 as an antenna. Therefore, the embodiment of the present invention does not elaborate on the method of using the power supply line 3 as the target power line for signal transmission.

[0042] Among them, when a certain power line communication device needs to communicate with other power line communication devices, for example, the power line communication device 1b needs to communicate with the power line communication device 1c. First, the power line communication device 1b generates a power line communication signal and converts it into a radio frequency signal for transmission to the ground wire 2. The radio frequency signal is transmitted on the ground wire 2 to the power line communication device 1c and received by the power line communication device 1c. Thus, communication between the two power line communication devices is achieved.

[0043] In the embodiment of the present invention, a power line communication signal transceiver circuit and a coupling circuit are provided in the power line communication device. Among them, the power line communication signal transceiver circuit is configured to receive and / or transmit power line communication signals, and the coupling circuit is configured to couple the power line communication circuit with the target power line in an antenna coupling manner, where the coupling circuit is connected between the power line communication signal transceiver circuit and the target power line. Thereby, it is possible to avoid measuring the voltage difference between the ground wire and the power supply line, thus avoiding adding an inductor for isolation, further simplifying the structure of the system, and reducing the cost of power communication.

[0044] Figure 4 is a schematic diagram of the power line communication device according to the embodiment of the present invention. As Figure 4 shown, the power line communication device 1 includes a power line communication signal transceiver circuit 11 and a coupling circuit 12.

[0045] Among them, the power line communication signal transceiver circuit 11 is configured to receive and / or transmit power line communication signals, and the power line communication signals are used to implement communication functions between at least two power line communication devices. Specifically, the power line communication device 1 converts the received data into a high-frequency carrier power line communication signal suitable for transmission on the power line through modulation technology, so that the low-frequency data signal is modulated onto the high-frequency carrier for long-distance and high-efficiency transmission on the power line. Then, the modulated signal is fed into the power line serving as an antenna through the coupling circuit 12. After the signal is fed into the power line, it will be transmitted along the power line until it is received by the power line communication device at the receiving end and demodulated and restored to the original user data according to the received data. That is to say, for the power line communication device that emits signals, the target power line serves as its transmitting antenna, and for the power line communication device that receives signals, the target power line serves as its receiving antenna.

[0046] The commonly used protocols in the power line communication system currently include DLT645 protocol, IEC 61850 protocol, and IEC 60870-5 series protocols. It should be noted that the modulation method of the power line communication signal in the embodiment of the present invention may be the same as or different from the modulation method of the power line communication signal in the prior art power line carrier communication technology. For example, for the same power line communication system, frequency modulation is used to implement communication through the prior art method. The embodiment of the present invention may still use the frequency modulation method, or may use methods such as amplitude modulation, phase modulation, and quadrature amplitude modulation to implement signal modulation.

[0047] In some embodiments, the power line communication signal transceiver circuit 11 is also connected to the ground wire and the power supply line at the same time to obtain power supply, so as to supply power to the power line communication signal transceiver circuit 11 through the ground wire 2 and the power supply line 3.

[0048] In some embodiments, the power line communication signal transceiver circuit 11 is formed as an integrated circuit. Specifically, by using an integrated circuit to implement the function of the power line communication signal transceiver circuit 11, not only the performance stability and reliability of the circuit are improved, but also its applicability in various power line communication systems is greatly optimized. By integrating complex signal processing and data transmission functions on a single chip, the overall energy consumption and cost of the system are effectively reduced, and at the same time, the installation and maintenance processes are simplified, providing strong support for the miniaturization and lightweight development of modern power line communication devices.

[0049] The coupling circuit 12 is connected between the power line communication signal transceiver circuit and the target power line, and is configured to couple the power line communication circuit with the target power line in an antenna coupling manner. Specifically, it is used to convert the power line communication signal sent by the power line communication signal transceiver circuit 11 into a radio frequency signal and effectively couple it to the power line for transmission. The coupling circuit can isolate the power frequency signal and filter out noise, ensuring that the carrier signal can be stably and efficiently transmitted in a complex power line environment. Through the filtering function and impedance matching design, the coupling circuit 12 can selectively allow carrier signals within a specific frequency range to pass through while blocking signals of other frequencies, thereby realizing the screening of specific signals and improving the reliability and quality of communication. Among them, the signals of other frequencies include the power frequency signal and noise that can affect the carrier signal.

[0050] Specifically, in the embodiment of the present invention, still taking the communication from the power line communication device 1b to the power line communication device 1c as an example for illustration. First, the power line communication signal transceiver circuit 11 of the power line communication device 1b sends a power line communication signal. The coupling circuit 12 of the power line communication device 1b couples and transmits the power line communication signal to the ground wire, and transmits it to the coupling circuit 12 of the power line communication device 1c through the ground wire for screening of signals within a specific frequency range, and finally receives it through the power line communication signal transceiver circuit 11 of the power line communication device 1c. Thus, the signal transmission between the two power communication devices is realized.

[0051] In some embodiments, the ground wire 2 and the power supply line 3 also include inductors L1 and L2. The inductors L1 and L2 are connected between the common end of the impedance matching circuit and the target power line, and the common end of the power line communication signal transceiver circuit and the target power line. It should be noted that the inductors L1 and L2 are the inductors included in the power line communication system itself to realize the communication function, rather than the inductors used to isolate system nodes. The function of the inductor L1 is to suppress common-mode interference and protect the circuit, and the function of the inductor L2 is to block high-frequency current and filter.

[0052] In the embodiment of the present invention, by setting a power line communication signal transceiver circuit and a coupling circuit in the power line communication device, wherein the power line communication signal transceiver circuit is configured to receive and / or transmit power line communication signals, and the coupling circuit is configured to couple the power line communication circuit with the target power line in an antenna coupling manner, wherein the coupling circuit is connected between the power line communication signal transceiver circuit and the target power line. Thus, by means of antenna coupling for signal transmission between power line communication devices, the voltage difference between the ground wire and the power supply line can be avoided, thereby avoiding adding inductors for isolation, further simplifying the structure of the system, and reducing the cost of power communication.

[0053] Figure 5It is the circuit diagram of the power line communication device according to the embodiment of the present invention, as Figure 5 shown. The power line communication device includes a power line communication signal transceiver circuit 11 and a coupling circuit 12. Among them, the power line communication signal transceiver circuit 11 includes a transmitting circuit 111 and a receiving circuit 112, and the coupling circuit 12 includes an impedance matching circuit 121 and a radio frequency signal processing circuit 122. Among them, the radio frequency signal processing circuit includes a balun 1221 and a filter 1222.

[0054] The transmitting circuit 111 is configured to convert the signal to be transmitted into a radio frequency signal. Among them, the conversion of the signal to be transmitted includes signal modulation and signal amplification. The signal modulation is specifically to modulate the signal to be transmitted onto a low-frequency or high-frequency carrier. In the power line carrier communication technology, the carrier bit is usually a signal in the range of dozens of kHz to hundreds of kHz. The modulation methods include amplitude modulation (AM, Amplitude Modulation), frequency modulation (FM, Frequency Modulation), or phase modulation (PM, Phase Modulation), etc. The signal amplification is specifically to amplify the signal through a power amplifier to ensure that the signal can overcome the attenuation and interference of the power line when transmitted on the power line.

[0055] The receiving circuit 112 is configured to receive the power line communication signal from the target power line and demodulate it, and then perform data processing on the demodulated power line communication signal to restore the original signal. Specifically, the receiving circuit 112 first couples out the power line communication signal from the power line, then amplifies the coupled power line communication signal through a low-noise amplifier, then sends the amplified signal into a demodulation circuit for demodulation to restore the original signal, and finally decodes and corrects the original signal.

[0056] The impedance matching circuit 121 is specifically used to achieve impedance matching between the target power line and the radio frequency signal processing circuit. Since power line carrier communication transmits data information at high speed on the path carrying the power frequency power signal, it has disadvantages such as a harsh working environment, large time-variation, and serious interference. The low- and medium-voltage distribution network has a complex structure, usually with multiple branches and distribution transformers connected in series along the line. Signals are easily reflected, resonated, and standing waves are generated, resulting in a strong frequency-selective fading problem of the signal, seriously affecting the communication quality, thus greatly reducing the accuracy of data transmission, and there are many difficulties in using the low- and medium-voltage distribution network as a data channel. Therefore, by setting the impedance matching circuit 121 to achieve impedance matching, it can adapt to different load conditions and improve the efficiency and accuracy of signal transmission in power line carrier communication.

[0057] The radio frequency signal processing circuit 122 is connected to the impedance matching circuit 121 and is used for processing radio frequency signals. Specifically, the radio frequency signal processing circuit 122 includes a balun 1221 and a filter 1222. Among them, the balun 1221 is connected to the transmitting circuit 111, and the filter is connected to the receiving circuit 112.

[0058] The balun 1221 is used to realize the conversion between balanced signals and unbalanced signals. Specifically, a balanced signal is a differential signal, specifically, two conductors are used to transmit signals with a 180-degree phase difference. An unbalanced signal is a single-ended signal, specifically, a signal is transmitted on one conductor, and the second conductor is used as a ground wire. The balun realizes signal conversion through the mutual coupling of inductance coils. In the embodiment of the present invention, the balun 1221 converts the radio frequency signal from an unbalanced signal to a balanced signal while keeping the amplitude and phase characteristics of the signal unchanged, thereby reducing the influence of electromagnetic interference and noise, improving the transmission quality of the radio frequency signal, and further ensuring the stable transmission of the signal. In some embodiments, the transmitting circuit 111 includes a positive output terminal (TXP) and a negative output terminal (TXN). Among them, both the positive output terminal and the negative output terminal are connected to the balun. The positive input terminal is responsible for receiving and preliminarily amplifying the signal, while the negative input terminal adjusts the amplifier gain through a feedback mechanism to ensure stable signal amplification and maintain good linearity and stability. Through the collaborative work of the positive input terminal and the negative input terminal, efficient signal transmission is achieved.

[0059] Filter 1222 is used to process the received power line communication signal to make the power line communication signal received by the receiving circuit 112 more accurate. Specifically, in the embodiment of the present invention, filter 1222 is used for frequency selection, noise removal, and signal enhancement. The filter can select and allow signals to pass through according to the required frequency range, that is, select signals from the frequency perspective by setting the upper and lower frequency limits. This frequency selection function enables filter 1222 to separate different communication channels in the communication system and prevent interference between channels. Filter 1222 can also remove unnecessary noise in the signal by blocking noise in a specific frequency range, thereby improving the quality and readability of the signal. Filter 1222 can also enhance the amplitude of the signal in a specific frequency range, thereby improving the signal quality and the accuracy of power line carrier communication. In some embodiments, the receiving circuit 112 includes a positive input terminal (RXP) and a negative input terminal (RXN), wherein the positive input terminal is connected to filter 1222, and the negative input terminal is connected to the ground terminal. Among them, the positive input terminal of the receiving circuit 112 is used to receive external signals and introduce them into the circuit for preliminary processing. The negative input terminal is connected to the feedback circuit and is used to adjust the gain and stability of the circuit to ensure that signals can be received and processed accurately and stably.

[0060] In the embodiment of the present invention, a power line communication signal transceiver circuit and a coupling circuit are provided in the power line communication device. Among them, the power line communication signal transceiver circuit is configured to receive and / or transmit power line communication signals, and the coupling circuit is configured to couple the power line communication circuit with the target power line in an antenna coupling manner, wherein the coupling circuit is connected between the power line communication signal transceiver circuit and the target power line. Thus, by means of antenna coupling for signal transmission between power line communication devices, the voltage difference between the measurement ground wire and the power supply wire can be avoided, thereby avoiding adding inductors for isolation, further simplifying the structure of the system, and reducing the cost of power communication.

[0061] Figure 6 is the circuit diagram of the power line communication system according to the embodiment of the present invention, as Figure 6 shown, in the power line communication system, multiple power line communication devices are connected to the ground wire 2, using the ground wire 2 as a common antenna, and realizing mutual communication between power line carrier communication systems through antenna coupling.

[0062] Specifically, the power line communication device 1a is used as the signal transmitting device, and the power line communication device 1c is used as the signal receiving device for illustration. First, the power line communication device 1a converts the signal to be transmitted into a radio frequency signal through signal modulation and signal amplification by the transmitting circuit 111, and then converts the radio frequency signal from an unbalanced signal to a balanced signal by a balun while maintaining the amplitude and phase characteristics of the signal unchanged. The input impedance and output impedance are matched through an impedance matching circuit to improve the stability of the radio frequency signal transmitted on the ground wire. After passing through the impedance matching circuit, the radio frequency signal enters the ground wire and is transmitted on the ground wire to the power line communication device 1c. After being converted by the impedance matching circuit, the radio frequency signal is subjected to frequency selection, noise removal, and signal enhancement through a filter. Specifically, it selects and allows the signal to pass according to the required frequency range, that is, selects the signal from the frequency perspective by setting the upper and lower frequency limits. After being processed by the filter, the radio frequency signal is received by the receiving circuit 112, amplified by a low noise amplifier, and then the amplified and filtered radio frequency signal is sent to a demodulation circuit for demodulation to restore the original signal. Thus, the communication between the power line communication device 1a and the power line communication device 1c is achieved.

[0063] In the embodiment of the present invention, a power line communication signal transceiver circuit and a coupling circuit are provided in the power line communication device. Among them, the power line communication signal transceiver circuit is configured to receive and / or transmit power line communication signals, and the coupling circuit is configured to couple the power line communication circuit with the target power line in an antenna coupling manner, where the coupling circuit is connected between the power line communication signal transceiver circuit and the target power line. Thus, by means of antenna coupling for signal transmission between power line communication devices, it is possible to avoid measuring the voltage difference between the ground wire and the power supply wire, thereby avoiding adding an inductor for isolation, further simplifying the structure of the system, and reducing the cost of power communication.

[0064] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A power line communication device, characterized in that: The power line communication device comprises: A power line communication signal transceiver circuit, configured to receive and / or transmit a power line communication signal; The coupling circuit is connected between the power line communication signal transceiver circuit and the target power line, and is configured to couple the power line communication signal transceiver circuit with the target power line in an antenna coupling manner, wherein the target power line is one of a power line or a ground line.

2. The power line communication device according to claim 1, characterized in that: The coupling circuit comprises: an impedance matching circuit, connected to the target power line, for performing impedance matching; and The radio frequency signal processing circuit is connected to the impedance matching circuit and is used for processing the radio frequency signal.

3. The power line communication device according to claim 2, characterized in that: The power line communication signal transceiver circuit includes a receiving circuit and a transmitting circuit; The RF signal processing circuit includes: a balanced-unbalanced converter connected to the transmitting circuit; and A filter is connected to the receiving circuit.

4. The power line communication device according to claim 3, characterized in that: The receiving circuit has a positive input terminal and a negative input terminal, the positive input terminal is connected to the filter, and the negative input terminal is connected to the ground terminal.

5. The power line communication device according to claim 3, characterized in that: The transmitting circuit includes a positive output terminal and a negative output terminal, and both the positive output terminal and the negative output terminal are connected to the balun.

6. The power line communication device according to claim 2, characterized in that: The power line communication signal transceiver circuit is connected to a ground line and a power line to obtain power supply.

7. The power line communication device according to claim 1, characterized in that: The power line communication signal transceiver circuit is formed as an integrated circuit.

8. The power line communication device according to claim 6, characterized in that: The target power line includes an inductor, and the inductor is between a common end of the impedance matching circuit and the target power line, and between a common end of the power line communication signal transceiver circuit and the target power line.

9. A power line communication system, characterized in that: The power line communication system comprises: Ground wire; Power cord; A plurality of power line communication devices according to any one of claims 1 to 8.

10. The power line communication system according to claim 9, characterized in that: The power line communication system further comprises a plurality of system nodes, and power supply ends of the system nodes are directly connected to the power line and the ground line.

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