A bidirectional power line communication system based on chopper communication

Abstract

The utility model discloses a kind of two-way power line communication systems based on chopper communication, it is related to power line communication technical field, wherein in sending end, the control input end of chopper sending circuit is electrically connected with the control signal output end of first MCU, and the power coupling end of chopper sending circuit is connected to power line;Signal output end of metering unit is electrically connected with the data acquisition end of first MCU, and metering unit is coupled to power line;In receiving end, signal input end of signal detection circuit is coupled to power line, and signal detection circuit is electrically connected with the communication of second MCU;Load control circuit is electrically connected with second MCU, and load control circuit is used for connecting external load;Nonvolatile memory is electrically connected with second MCU, and through the above connection relationship, how to be solved in the premise of not needing to add additional special communication hardware, utilize system inherent module to realize the technical problem of two-way data transmission on power line.

Description

Technical Field

[0001] This utility model relates to the field of power line communication technology, and in particular to a bidirectional power line communication system based on chopper communication. Background Technology

[0002] Power line communication (PLC) technology is a communication method that uses existing power lines as the data transmission medium. Because it does not require the laying of additional communication lines, it has significant advantages such as low cost, wide coverage, and ease of deployment. It is widely used in equipment control and data acquisition in fields such as smart grids, smart homes, and industrial automation.

[0003] Traditional power line communication systems, especially in unidirectional control or simple data acquisition scenarios, typically employ a unidirectional communication mode. This means the master control unit (sender) sends control commands or configuration parameters to the controlled unit (receiver), with the receiver passively executing them. However, this unidirectional mode has significant limitations: the sender cannot know whether the command has been successfully received and correctly executed by the receiver, lacking status feedback and transmission confirmation mechanisms, resulting in insufficient system reliability and controllability. In applications requiring high reliability, such as critical equipment control or billing command issuance, unreliable communication can lead to control failures or financial disputes.

[0004] To monitor the receiver's status or confirm commands, some solutions attempt to introduce bidirectional communication. A common approach is to add a separate signal transmitting circuit (such as an additional carrier modulation module) to the receiver, forming an independent communication channel with the transmitter, similar to full-duplex or half-duplex communication. However, this approach has the following drawbacks: First, it significantly increases the complexity and hardware cost of the receiver circuitry, requiring additional signal generators, modulators, and coupling circuits; second, maintaining the stability and interference resistance of two independent communication links is more challenging in harsh power line noise environments; third, the added hardware also leads to higher power consumption and larger size, hindering device integration and miniaturization.

[0005] On the other hand, in terms of communication protocols and efficiency, many existing systems need to resend the complete control command (including all configuration details) from the sender to the receiver every time control needs to be executed, regardless of whether the instruction is the same or the parameters have changed. This data transmission method generates a large amount of redundant information, especially in scenarios where the same or similar operations need to be performed frequently. It consumes valuable communication bandwidth, reduces the system's response speed, and increases the probability of errors in noisy environments due to excessively long data packets.

[0006] Therefore, how to achieve reliable bidirectional data interaction and improve communication efficiency on a single power line medium without significantly increasing hardware costs and complexity has become a pressing technical problem in this field. This invention aims to address the shortcomings of the existing technology by proposing an innovative solution. Utility Model Content

[0007] This invention provides a bidirectional power line communication system based on chopper communication, which can solve the technical problem of how to achieve bidirectional data transmission on power lines using the system's inherent modules without adding extra dedicated communication hardware.

[0008] To address the aforementioned problems, this utility model provides a bidirectional power line communication system based on chopper communication, comprising a power line and a transmitting end and a receiving end connected through the power line; the transmitting end includes: a first MCU, a chopper transmitting circuit, and a metering unit, wherein the control input terminal of the chopper transmitting circuit is electrically connected to the control signal output terminal of the first MCU, and the power coupling terminal of the chopper transmitting circuit is connected to the power line; the signal output terminal of the metering unit is electrically connected to the data acquisition terminal of the first MCU, and the sampling terminal of the metering unit is coupled to the power line; The receiving end includes a second MCU, a signal detection circuit, a load control circuit, and a non-volatile memory. The signal input terminal of the signal detection circuit is coupled to the power line, and the signal output terminal of the signal detection circuit is electrically connected to the communication input terminal of the second MCU. The control input terminal of the load control circuit is electrically connected to the control signal output terminal of the second MCU, and the output terminal of the load control circuit is used to connect an external load. The non-volatile memory is electrically connected to the second MCU and is used to store data.

[0009] The present invention provides a bidirectional power line communication system based on chopper communication, which, compared with the prior art, has the following beneficial effects, but is not limited to: By constructing a hardware system comprising specific modules, such as a chopper transmitting circuit, a signal detection circuit, a load control circuit, a metering unit, and their interconnections, a complete bidirectional data communication closed loop is achieved on a single power line without requiring any additional dedicated communication hardware. This is achieved by cleverly utilizing the load control circuit as a reverse "transmitting" unit and the metering unit as a reverse "receiving" unit. This not only overcomes the limitations of traditional unidirectional communication, meeting the needs of scenarios such as status feedback and control confirmation, but also fundamentally simplifies the system structure and significantly reduces hardware costs and complexity. The inclusion of non-volatile memory provides the hardware foundation for efficient persistent data storage and retrieval.

[0010] Preferably, the load control circuit is a relay or MOSFET switching circuit.

[0011] Preferably, the metering unit is an energy metering chip.

[0012] Preferably, the metering unit includes a current sampling circuit and a voltage sampling circuit, and the output terminals of the current sampling circuit and the voltage sampling circuit are respectively connected to the analog-to-digital conversion port of the first MCU.

[0013] Preferably, the signal detection circuit includes a signal coupling module, a filtering and amplification module, and a signal shaping module connected in sequence.

[0014] Preferably, the signal coupling module includes a coupling transformer, the primary coil of which is connected in parallel to the power line.

[0015] Preferably, the filtering and amplification module includes a filtering circuit and an operational amplifier, the input terminal of the filtering circuit is connected to the secondary coil of the coupling transformer, and the output terminal of the filtering circuit is connected to the input terminal of the operational amplifier.

[0016] Preferably, the signal shaping module is a voltage comparator, one input terminal of which is connected to the output terminal of the operational amplifier, the other input terminal is connected to a reference voltage, and its output terminal is connected to the communication input terminal of the second MCU.

[0017] Preferably, the chopper transmitting circuit includes an on / off control unit composed of switching devices, which is connected in series in the power line loop or in parallel on the power line through a coupling element, and the control electrode of the switching device is connected to the control signal output terminal of the first MCU.

[0018] Preferably, both the transmitting end and the receiving end are equipped with a power module, and the input end of the power module is connected to the power line. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of a bidirectional power line communication system based on chopper communication according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the connection between the metering unit and the first MCU in an embodiment of the present invention; Figure 3 This is a schematic diagram of the overall structure of the signal detection circuit according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection between the transmitter, receiver, and power module in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0026] like Figures 1 to 4 As shown in the figure, this utility model provides a bidirectional power line communication system based on chopper communication, including a power line and a transmitting end and a receiving end connected through the power line; the transmitting end includes: a first MCU, a chopper transmitting circuit and a metering unit, the control input terminal of the chopper transmitting circuit is electrically connected to the control signal output terminal of the first MCU, and the power coupling terminal of the chopper transmitting circuit is connected to the power line; the signal output terminal of the metering unit is electrically connected to the data acquisition terminal of the first MCU, and the sampling terminal of the metering unit is coupled to the power line; The receiving end includes a second MCU, a signal detection circuit, a load control circuit, and a non-volatile memory. The signal input terminal of the signal detection circuit is coupled to the power line, and the signal output terminal of the signal detection circuit is electrically connected to the communication input terminal of the second MCU. The control input terminal of the load control circuit is electrically connected to the control signal output terminal of the second MCU, and the output terminal of the load control circuit is used to connect an external load. The non-volatile memory is electrically connected to the second MCU and is used to store data.

[0027] Based on the above structure, this application can realize two communication steps: forward communication and reverse communication.

[0028] Specifically, these include: Forward communication steps: The first MCU at the transmitting end generates a control signal according to the data to be transmitted, drives the chopping transmission circuit to chop the voltage / current of the power line (such as periodic switching), and loads the data onto the power line in the form of a chop signal. The receiving end captures the chop signal on the power line through the signal detection circuit, decodes it in the first MCU, and completes the data reception.

[0029] The first MCU serves as the control core of the transmitting end, used to generate long frame data containing configuration parameters or short frame data containing action instructions, and to control the chopper transmitting circuit to encode them into chopper signals and send them to the power line.

[0030] Forward communication steps include: Configuration phase: The sending end generates long frame data containing at least one action configuration parameter, encodes the long frame data into a chopping signal and sends it to the receiving end. The receiving end receives and parses the long frame data, and stores the parsed action configuration parameter locally.

[0031] If long frame data is parsed, the configuration parameters in it are stored in the local non-volatile memory; if short frame data is parsed, the corresponding configuration parameters pre-stored in the local non-volatile memory are called according to the action instructions in the short frame data, the load control circuit is controlled to perform the corresponding action, and after responding to the short frame data, the load control circuit is controlled to switch the load state in a preset power change mode, and the reverse data is encoded into the power change of the power line.

[0032] The second MCU is used to detect and decode the chop signal from the power line through the signal detection circuit to obtain data from the transmitting end; and to control the load control circuit according to the reverse data to be transmitted, so as to change the switching state of the load connected to the receiving end, thereby generating a circuit power change with a specific pattern.

[0033] The reverse communication steps are as follows: After parsing the forward short frame instruction, the receiving end controls the load switch state to switch periodically, such as switching the load according to the preset pattern of "on for 100ms / off for 200ms", so that the circuit power changes regularly, and the reverse data is encoded with the power change pattern; the sending end collects the circuit power data in real time, samples and parses the power change pattern, restores the reverse data transmitted by the receiving end, completes the bidirectional communication closed loop, and at the same time confirms that the forward data has been received.

[0034] A transmission confirmation mechanism is constructed through forward and reverse communication, enabling the sending end to confirm whether the command has been successfully received and executed, thus improving communication reliability. The system requires no additional communication hardware; it utilizes power changes at the receiving end to achieve reverse data encoding, and the sending end samples and analyzes these power changes through a metering unit, completing the bidirectional communication loop and transmission confirmation.

[0035] In this embodiment, the load control circuit is a relay or a MOSFET switching circuit.

[0036] Relay-type load control circuits are simple in structure and low in cost, making them suitable for scenarios requiring high load capacity but not high control precision. MOSFET switching circuits, on the other hand, offer fast switching speeds and high control precision, making them suitable for applications with more precise load control requirements. In practical applications, the appropriate load control circuit type can be selected based on specific needs.

[0037] In the above structure, the metering unit is an energy metering chip.

[0038] As the core component of the metering unit, the power metering chip accurately measures key parameters such as voltage, current, and power on power lines and transmits this data in real time to the first MCU for further processing and analysis. Its high precision and stability ensure the accuracy and reliability of the communication system during data acquisition and transmission. Simultaneously, the power metering chip also possesses multiple protection functions, such as overcurrent protection and overvoltage protection, effectively improving the system's safety and stability. In practical applications, different models and specifications of power metering chips can be selected according to specific needs to meet the metering requirements of different scenarios.

[0039] In this embodiment of the application, the metering unit includes a current sampling circuit and a voltage sampling circuit, and the output terminals of the current sampling circuit and the voltage sampling circuit are respectively connected to the analog-to-digital conversion port of the first MCU.

[0040] The metering unit can be built from discrete components: the current sampling circuit uses a sampling resistor in conjunction with an operational amplifier to amplify the signal; the voltage sampling circuit uses a resistor divider network. The first MCU acquires the amplified current signal and the divided voltage signal through its built-in ADC module, and calculates the real-time power through software algorithms (such as multiplication and filtering).

[0041] The current sampling circuit employs a high-precision current transformer to accurately acquire the current signal on the power line and convert it into a voltage signal proportional to the current magnitude, which is then output to the analog-to-digital converter (ADC) port of the first MCU. The voltage sampling circuit samples the voltage on the power line using precision resistor dividers or voltage transformers, and similarly transmits the sampled voltage signal to the ADC port of the first MCU. By processing and analyzing these sampled signals, the first MCU can monitor the voltage and current conditions on the power line in real time, providing accurate data support for subsequent operations such as chopping signal generation, data transmission, and load control. Furthermore, this independent current and voltage sampling circuit design minimizes mutual interference during the sampling process, further improving sampling accuracy and stability, and contributing to the overall performance and reliability of the bidirectional power line communication system.

[0042] In the above structure, the signal detection circuit includes a signal coupling module, a filtering and amplification module, and a signal shaping module connected in sequence.

[0043] The signal detection circuit adopts a three-level processing architecture. The signal coupling module is responsible for extracting the signal from the power line without contact; the filtering and amplification module is responsible for filtering out the inherent power frequency interference and high-frequency noise of the power line, and amplifying the weak effective signal to a level suitable for processing; the signal shaping module is responsible for shaping the analog signal waveform into a digital square wave so that the second MCU can accurately identify and decode it.

[0044] This three-tier processing architecture significantly improves the anti-interference capability and reliability of forward communication. Targeted filtering effectively suppresses the harsh noise environment of power lines; signal amplification ensures the correct capture of weak chopper signals; and waveform shaping eliminates signal edge jitter, greatly reducing the decoding error rate of the second MCU.

[0045] In this embodiment, the signal coupling module includes a coupling transformer, the primary coil of which is connected in parallel to the power line.

[0046] In the above structure, the signal coupling module specifically uses a coupling transformer. Its primary coil is directly connected in parallel between the live wire (L) and the neutral wire (N) of the power line to induce voltage-type chopping signals; or it is connected in series with the live wire to induce current-type chopping signals. The transformer itself provides electrical isolation, ensuring the safety of the downstream circuitry.

[0047] The coupling transformer achieves electrical isolation between the front-end high-voltage circuit and the back-end low-voltage processing circuit, greatly improving the system's safety and reliability. Simultaneously, the transformer possesses certain band-pass characteristics, which can initially filter out some noise from non-target frequency bands.

[0048] In this embodiment of the application, the filtering and amplification module includes a filtering circuit and an operational amplifier. The input terminal of the filtering circuit is connected to the secondary coil of the coupling transformer, and the output terminal of the filtering circuit is connected to the input terminal of the operational amplifier.

[0049] In the above structure, the filtering and amplification module specifically consists of a passive RC filter circuit or an active filter circuit and an operational amplifier. The filter circuit performs frequency band selection on the signal output from the transformer secondary, while the operational amplifier linearly amplifies the signal to meet the amplitude requirements of the subsequent shaping circuit.

[0050] Through flexibly designed filter circuits, interference in specific frequency bands (such as harmonics at specific frequencies) can be precisely filtered out, enabling the system to adapt to power line noise environments with varying characteristics. Operational amplifiers ensure that the signal has sufficient signal-to-noise ratio and driving capability, laying the foundation for precise signal shaping.

[0051] In this embodiment, the signal shaping module is a voltage comparator. One input terminal of the voltage comparator is connected to the output terminal of the operational amplifier, the other input terminal is connected to a reference voltage, and its output terminal is connected to the communication input terminal of the second MCU.

[0052] In the above structure, the signal shaping module specifically uses a voltage comparator (such as LM393). The amplified analog signal output from the operational amplifier is connected to one input of the comparator, and a carefully set reference voltage is connected to the other input. The comparator compares the analog signal with the reference voltage and outputs a clean, steep digital level signal to the second MCU.

[0053] The voltage comparator achieves a perfect conversion from analog to digital signals. It effectively eliminates jitter when the signal exceeds the threshold, producing a clear output waveform with sharp edges. This allows the second MCU to accurately capture each chopper pulse through simple digital I / O interrupts or polling, greatly improving the accuracy and stability of forward data decoding.

[0054] In this embodiment of the application, the chopper transmitting circuit includes an on / off control unit composed of switching devices. The on / off control unit is connected in series in the power line circuit or in parallel on the power line through a coupling element. The control electrode of the switching device is connected to the control signal output terminal of the first MCU.

[0055] In the above structure, the core of the chopper transmitting circuit is an on / off control unit composed of switching devices (such as MOSFETs or IGBTs). This unit can be connected in series in the power line loop to directly control the loop's on / off state; or it can be connected in parallel to the power line through a coupling capacitor or transformer to couple the chopper signal to the line via current injection or voltage modulation.

[0056] Two basic and efficient chopper signal generation methods are provided. The series method has a simple circuit and a large modulation depth; the parallel method has less impact on the main power supply circuit and is safer. Both methods can efficiently convert the digital instructions of the first MCU into physical signals that can be transmitted on the power line, which is the basis for realizing forward communication.

[0057] In this embodiment of the application, both the transmitting end and the receiving end are provided with a power module, and the input end of the power module is connected to the power line.

[0058] In the above structure, both the transmitting and receiving ends are equipped with independent power supply modules. These modules draw power directly from the power line and typically employ capacitor-step-down or switching power supply (such as AC-DC chips) solutions to convert high-voltage AC (such as 220V AC) into stable low-voltage DC (such as 3.3V or 5V DC) required by the various chips and circuits in the system.

[0059] The system achieves independent power supply and plug-and-play functionality. No additional power lines are needed for the communication module, fully demonstrating the core advantage of powerline communication—"utilizing existing lines"—simplifying the installation process and expanding application scenarios. Simultaneously, the independent power supply design ensures stable operation of the communication circuit, unaffected by load changes.

[0060] Based on the above structure, the workflow of the system in this utility model application includes: The forward communication phase from sender to receiver includes the configuration phase and the execution phase: Configuration Phase: When the system needs to configure complex actions at the receiving end, the first MCU at the transmitting end generates a long frame of data. This long frame contains one or more action records, each of which includes at least an action number and corresponding detailed configuration parameters (such as load switching cycle, trigger conditions, etc.). The first MCU drives the chopper transmission circuit to encode the long frame of data into a series of chopper signals and send them to the power line. The signal detection circuit at the receiving end captures these chopper signals, and the second MCU decodes them to obtain the long frame of data. It then persistently stores the action records within it in its local non-volatile memory (such as Flash or EEPROM).

[0061] Execution Phase: After configuration, when a configured action needs to be triggered, the first MCU at the sending end only needs to generate a short frame of data. This short frame is extremely small, mainly containing the action number to be executed, without needing to carry all configuration parameters again. This short frame is also transmitted via a chopping signal. Upon receiving the short frame, the second MCU at the receiving end parses the action number, then retrieves the pre-stored configuration parameters corresponding to that number from its local non-volatile memory, and controls the load control circuit to execute the corresponding action. Through this "secret" mechanism, the data transmission volume during the execution phase can be reduced by more than 80%, greatly improving communication efficiency.

[0062] Instead of using additional independent hardware channels (such as dual-frequency carrier circuits or channel switching modules) required for traditional full-duplex or half-duplex systems to construct the reverse link, the system utilizes the existing load control circuitry at the receiver as a "transmitter," generating specific power change codes by controlling the load's on / off state. Simultaneously, the transmitter uses its inherent metering unit as a "receiver," monitoring power changes in real time. This enables bidirectional data communication on a single power line without requiring additional communication hardware. This avoids the cost and complexity issues associated with adding hardware and cleverly utilizes the power signal itself as a carrier, enhancing its adaptability to power line noise environments. In summary, the communication method and corresponding execution system of this application break through the limitations of traditional one-way communication, realize bidirectional data interaction between the sending end and the receiving end, meet the rigid requirements of application scenarios such as status feedback and control confirmation, and construct a transmission confirmation mechanism through the power-coded response of the receiving end, so that the sending end can know whether the instruction has been successfully received and executed, thereby improving communication reliability. Furthermore, by separating complete configuration information (long frame) from concise execution instructions (short frame), redundant data is avoided from being repeatedly transmitted when frequently executing actions, reducing the amount of data transmitted, significantly reducing communication bandwidth usage, improving response speed, and thus improving communication efficiency.

[0063] The above-disclosed embodiments are only a few specific examples of the present utility model. However, the embodiments of the present utility model are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present utility model.

Claims

1. A bidirectional power line communication system based on chopper communication, characterized in that, Includes power lines and a transmitting end and a receiving end connected through the power lines; The sending end includes: First MCU; A chopper transmitting circuit, wherein the control input terminal of the chopper transmitting circuit is electrically connected to the control signal output terminal of the first MCU, and the power coupling terminal of the chopper transmitting circuit is connected to the power line; A metering unit, wherein the signal output terminal of the metering unit is electrically connected to the data acquisition terminal of the first MCU, and the sampling terminal of the metering unit is coupled to the power line; The receiving end includes: Second MCU; A signal detection circuit, wherein the signal input terminal of the signal detection circuit is coupled to the power line, and the signal output terminal of the signal detection circuit is electrically connected to the communication input terminal of the second MCU; A load control circuit, wherein the control input terminal of the load control circuit is electrically connected to the control signal output terminal of the second MCU, and the output terminal of the load control circuit is used to connect an external load; A non-volatile memory is electrically connected to the second MCU, and the non-volatile memory is used to store data.

2. The bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, The load control circuit is a relay or MOSFET switching circuit.

3. A bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, The metering unit is an energy metering chip.

4. A bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, The metering unit includes a current sampling circuit and a voltage sampling circuit, and the output terminals of the current sampling circuit and the voltage sampling circuit are respectively connected to the analog-to-digital conversion port of the first MCU.

5. A bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, The signal detection circuit includes a signal coupling module, a filtering and amplification module, and a signal shaping module connected in sequence.

6. A bidirectional power line communication system based on chopper communication according to claim 5, characterized in that, The signal coupling module includes a coupling transformer, the primary coil of which is connected in parallel to the power line.

7. A bidirectional power line communication system based on chopper communication according to claim 6, characterized in that, The filtering and amplification module includes a filtering circuit and an operational amplifier. The input terminal of the filtering circuit is connected to the secondary coil of the coupling transformer, and the output terminal of the filtering circuit is connected to the input terminal of the operational amplifier.

8. A bidirectional power line communication system based on chopper communication according to claim 7, characterized in that, The signal shaping module is a voltage comparator. One input terminal of the voltage comparator is connected to the output terminal of the operational amplifier, and the other input terminal is connected to a reference voltage. Its output terminal is connected to the communication input terminal of the second MCU.

9. A bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, The chopper transmitting circuit includes an on / off control unit composed of switching devices. The on / off control unit is connected in series in the power line circuit or in parallel on the power line through a coupling element. The control electrode of the switching device is connected to the control signal output terminal of the first MCU.

10. A bidirectional power line communication system based on chopper communication according to claim 1, characterized in that, Both the transmitting end and the receiving end are equipped with a power module, and the input end of the power module is connected to the power line.

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