Method for realizing three-phase electric energy meter PRIME communication coupling phase adaptive switching

Abstract

The invention provides a method for realizing three-phase electric energy meter PRIME communication coupling phase adaptive switching, and the method comprises the steps: switching the phase of the current PRIME signal coupling connection through a power line phase coupling control circuit, monitoring the received effective PRIME signals through a physical layer protocol, carrying out the statistics and recognition of the optimal phase in the current power line environment, and carrying out the self-adaptive switching of the communication coupling phase of the three-phase electric energy meter. Switching to a corresponding phase path, so that signal transmission can be carried out through an optimal phase in a specific deployment environment and a current channel state, thereby improving the stability of a network and keeping an operation state with an optimal communication effect; the problem that when the PRIME communication technology is applied to the three-phase electric energy meter, the network stability and the communication effect are poor in part of field deployment environments due to fixed single-phase coupling is effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of power line carrier communication, and in particular to a method for realizing adaptive switching of PRIME communication coupling phases of a three-phase electric energy meter. Background Art

[0002] PRIME is an OFDM (Orthogonal Frequency Division Multiplexing) power line carrier communication technology standard currently widely used in low-voltage power metering systems. It is developed and maintained by the PRIME Alliance. After several years of development, the PRIME standard has been widely used in many countries around the world due to its well-defined and mature certification. More than 10 million electric energy meter products of many equipment manufacturers have been deployed and applied on site. The PRIME network is mainly composed of two types of network nodes, namely the Base Node (BN, master node) integrated in the concentrator device and the Service Node (SN, slave node) integrated in the electric energy meter and repeater equipment.

[0003] When PRIME communication technology is applied to three-phase electric energy meters, the signal strength of each phase is reduced due to power dispersion when the signal of a specific transmission power is transmitted simultaneously in three phases, and the signal is easily distorted due to the multipath propagation effect, so single-phase coupling is often used for signal transmission.

[0004] But in fact, in different field deployment environments, the signal transmission impedance and noise environment of each phase are very likely to be different and easy to change over time, and the physical connection topology between the electric energy meters is also different, that is, the phase used for signal coupling of the three-phase electric energy meter and its adjacent parent node may not be in the same phase, and the signal transmission between different phases is often less effective. All these result in that if the three-phase electric energy meter adopts a fixed single-phase coupling to transmit the signal, it cannot be guaranteed to be applicable in different field deployment environments, and it is impossible to always maintain the stability of the network and the optimal operating state of the communication effect.

[0005] Therefore, it is difficult to ensure long-term stable communication quality by fixedly selecting a certain phase for communication. At the same time, the volatility of signal quality at different phases makes it difficult for a simple static selection scheme to adapt to the complex and changeable actual transmission environment. Summary of the invention

[0006] The purpose of the present invention is to propose a method for realizing adaptive switching of PRIME communication coupling phase of three-phase electric energy meters in order to solve the problem of poor stability and communication effect when three-phase electric energy meters currently use fixed single-phase coupling to transmit signals.

[0007] The technical solution of the present invention is:

[0008] The present invention provides a method for realizing phase adaptive switching of PRIME communication coupling of a three-phase electric energy meter, the method comprising the following steps:

[0009] Acquire a phase selection signal in a power line phase coupling control circuit, wherein the phase selection signal is used to control the power line phase coupling control circuit to switch among three phases in sequence and maintain a preset time;

[0010] During each phase coupling period, the physical layer protocol is used to monitor the received valid communication signals respectively, and the quality and quantity values ​​of the signals received on each phase are statistically calculated;

[0011] According to the preset judgment rules, the optimal phase in the current power line environment is judged;

[0012] The power line phase coupling control circuit is controlled to switch to the path corresponding to the optimal phase, and subsequent networking and communication are performed through the optimal phase from then on.

[0013] Further, controlling the power line phase coupling control circuit to switch among the three phases in sequence is specifically as follows:

[0014] By controlling the power line phase coupling control circuit, the PRIME signal transmission line is coupled and connected to the power line phases A, B and C respectively, so that its signal is transmitted from the coupled phases.

[0015] Further, the power line phase coupling control circuit includes:

[0016] The transmission signal coupling circuit includes diodes D1, D2 and transformer T1, and the input is the differential output signals TXOUTN and TXOUTP of the PRIME signal, and the output is the power lines L and N, wherein the power line L is connected to the control signal terminals PHASE_A, PHASE_B, and PHASE_C of the corresponding phase according to the control signals of each phase relay;

[0017] and a three-phase relay control circuit, wherein;

[0018] Phase A relay control circuit, composed of resistors R1, R2, capacitor C1, transistor Q1, diode D3 and relay J1, and relay J1 is in a normally closed state. When the control signal RELAY_A is at a high level, relay J1 is disconnected, and the power line L is disconnected from the A-phase control signal terminal PHASE_A, otherwise they are connected;

[0019] Phase B relay control circuit, composed of resistors R3, R4, capacitor C2, transistor Q2, diode D4 and relay J2, and relay J2 is normally open. When the control signal RELAY_B is at a low level, relay J1 is disconnected, and the power line L is disconnected from the B-phase control signal terminal PHASE_B, otherwise they are connected.

[0020] The phase C relay control circuit is composed of resistors R5 and R6, capacitor C3, transistor Q3, diode D5 and relay J3, and the relay J3 is in a normally open state. When the control signal RELAY_C is at a low level, the relay J3 is disconnected, and the power line L is disconnected from the C phase control signal terminal PHASE_C, otherwise they are connected;

[0021] Through the combination of the three-phase relay control circuit and the three phase relay control signals, the three phases are coupled and connected in sequence.

[0022] Furthermore, the physical layer protocol is used to monitor the received valid communication signals respectively, and the quality and quantity of the signals received at each phase are statistically calculated as follows:

[0023] Using a transceiver chip that complies with the PRIME physical layer standard, it receives signals from the power line environment and performs identification, demodulation, error correction and verification, and then reports them to the application according to the PRIME MAC layer protocol PDU format;

[0024] The application layer program records the number of PDUs received, the signal strength RSSI value, and the signal-to-noise ratio SNR value.

[0025] Furthermore, according to the preset judgment rules, the optimal phase in the current power line environment is determined as follows: based on the signal quality and quantity values ​​received at each phase, a comparison is performed to determine the phase with the best received signal quality or the largest number as the optimal phase applicable to the current power line environment.

[0026] Furthermore, if the number of phases involved in the determination is zero, the preset default phase is determined as the optimal phase;

[0027] If the number of phases involved in the judgment is one, then the phase is determined as the optimal phase;

[0028] If the number of phases involved in the judgment is greater than one, the phase obtained by the judgment rule is determined as the optimal phase.

[0029] Furthermore, the judgment rule is based on the signal quality and quantity values, and the priorities from high to low are average signal-to-noise ratio, average signal strength and PDU quantity.

[0030] Furthermore, the judgment rules are based on the signal quality and quantity values, and the priorities from high to low are average signal-to-noise ratio, average signal strength and PDU quantity, specifically:

[0031] Record the number of PDUs received from each phase, as well as the signal strength RSSI value and signal-to-noise ratio SNR value of each PDU, perform statistics and calculations, and obtain the number of PDUs, average RSSI value, and average SNR value of each phase;

[0032] Compare the average SNR values ​​of each phase; if the average SNR value of a phase is the largest, the received signal-to-noise ratio of this phase is optimal and is determined as the optimal phase; if the average SNR values ​​are the same, continue;

[0033] Further compare the average RSSI values ​​of each phase; if the average RSSI value of a phase is the largest, the received signal strength of this phase is optimal and is determined as the optimal phase; if the average SNR value and the average RSSI value are the same, continue;

[0034] The number of PDUs in each phase is further compared. If the average number of PDUs in a phase is the largest, the number of received signals in this phase is optimal and is determined to be the optimal phase. If the average SNR value, average RSSI value, and number of PDUs are the same, the preset default phase A is determined to be the optimal phase.

[0035] Furthermore, the average signal-to-noise ratio and the average signal strength are calculated as follows:

[0036] Take the minimum value n of the number of PDUs received in each phase; sort the reception records of the phases with a reception count greater than 0 according to the SNR value from large to small; take the first n records to obtain their average SNR value and average RSSI value.

[0037] Beneficial effects of the present invention:

[0038] The method for realizing adaptive switching of PRIME communication coupling phase of a three-phase electric energy meter of the present invention switches the phase of the current PRIME signal coupling connection through a phase coupling control circuit, monitors the received valid PRIME signals respectively by using a physical layer protocol, and statistically calculates the quality and quantity of the signals received on each phase, identifies the optimal phase in the current power line environment, and then switches to the corresponding phase path through the phase coupling control circuit, so that the signal can be transmitted through the optimal phase in a specific deployment environment and current channel state, thereby improving the stability of the network and maintaining the operating state with the best communication effect; effectively solves the problem that when PRIME communication technology is applied to three-phase electric energy meters, the network stability and communication effect in some field deployment environments are poor due to fixed single-phase coupling.

[0039] In the present invention, during each phase coupling period, the received effective signal is monitored, and the signal quality and quantity parameters are statistically calculated; based on the priority judgment rules of average signal-to-noise ratio, average signal strength and PDU number, the optimal communication phase is determined. When no phase is involved in the judgment, the preset default phase is used, and when there is a single phase, it is directly determined as the optimal phase. When there are multiple phases, the optimal phase is selected according to the judgment rules; finally, the intelligent adaptive selection of the power line communication phase is realized, and the communication quality and stability are improved.

[0040] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0042] Figure 1 A schematic diagram of the PRIME network structure of the present invention is shown.

[0043] Figure 2 A power line phase coupling control circuit diagram according to an embodiment of the present invention is shown.

[0044] Figure 3 FIG. 4 is a flow chart showing PRIME signal monitoring statistics according to an embodiment of the present invention.

[0045] Figure 4 FIG. 4 is a flowchart of determining the optimal coupling phase of a PRIME signal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0047] like Figure 1-4 The present invention provides a method for realizing phase adaptive switching of PRIME communication coupling of a three-phase electric energy meter, the method comprising the following steps:

[0048] Acquire a phase selection signal in a power line phase coupling control circuit, wherein the phase selection signal is used to control the power line phase coupling control circuit to switch among three phases in sequence and maintain a preset time;

[0049] During each phase coupling period, the physical layer protocol is used to monitor the received valid communication signals respectively, and the quality and quantity values ​​of the signals received on each phase are statistically calculated;

[0050] According to the preset judgment rules, the optimal phase in the current power line environment is judged;

[0051] The power line phase coupling control circuit is controlled to switch to the path corresponding to the optimal phase, and subsequent networking and communication are performed through the optimal phase from then on.

[0052] In this embodiment, according to the control signal of the power line phase coupling control circuit, the three phases are switched in turn and maintained for a certain period of time, signals are received from the power line environment, and the received signals are identified, demodulated, error corrected and verified. The processed valid PRIME signal is reported to the application through the PRIME MAC layer protocol PDU format. The application records the number of PDUs received in each phase, as well as their respective signal strength RSSI values ​​and signal-to-noise ratio SNR values. According to the quality and quantity values ​​of the signals received in each phase, they are compared and analyzed, so that the PRIME signal is transmitted from the optimal phase.

[0053] In one example, controlling the power line phase coupling control circuit to switch among the three phases in sequence is specifically as follows: controlling the power line phase coupling control circuit so that the PRIME signal transmission line is coupled and connected to the power line phase A, phase B, and phase C respectively, so that its signal is transmitted from the coupled phases; Figure 2 As shown, the power line phase coupling control circuit includes:

[0054] The transmission signal coupling circuit includes diodes D1, D2 and transformer T1, and the input is the differential output signals TXOUTN and TXOUTP of the PRIME signal, and the output is the power lines L and N, wherein the power line L is connected to the control signal terminals PHASE_A, PHASE_B, and PHASE_C of the corresponding phase according to the control signals of each phase relay;

[0055] and a three-phase relay control circuit, wherein;

[0056] Phase A relay control circuit, composed of resistors R1, R2, capacitor C1, transistor Q1, diode D3 and relay J1, and relay J1 is in a normally closed state. When the control signal RELAY_A is at a high level, relay J1 is disconnected, and the power line L is disconnected from the A-phase control signal terminal PHASE_A, otherwise they are connected;

[0057] Phase B relay control circuit, composed of resistors R3, R4, capacitor C2, transistor Q2, diode D4 and relay J2, and relay J2 is normally open. When the control signal RELAY_B is at a low level, relay J1 is disconnected, and the power line L is disconnected from the B-phase control signal terminal PHASE_B, otherwise they are connected.

[0058] The phase C relay control circuit is composed of resistors R5 and R6, capacitor C3, transistor Q3, diode D5 and relay J3, and the relay J3 is in a normally open state. When the control signal RELAY_C is at a low level, the relay J3 is disconnected, and the power line L is disconnected from the C phase control signal terminal PHASE_C, otherwise they are connected;

[0059] Through the combination of the three-phase relay control circuit and the three phase relay control signals, the three phases are coupled and connected in sequence.

[0060] Among them, the relationship between the phase selection of the phase coupling control circuit and the relay control signal is as follows:

[0061]

[0062] In one example, the physical layer protocol is used to monitor the received valid communication signals respectively, and statistically calculate the quality and quantity of the signals received on each phase as follows:

[0063] Using a transceiver chip that complies with the PRIME physical layer standard, it receives signals from the power line environment and performs identification, demodulation, error correction and verification, and then reports them to the application according to the PRIME MAC layer protocol PDU format;

[0064] The application layer program records the number of PDUs received, the signal strength RSSI value, and the signal-to-noise ratio SNR value.

[0065] In this embodiment, according to the PRIME physical layer standard, a transceiver chip is used to receive signals from the power line environment; the received signal is demodulated through the receiver processing flow to obtain the original data of the baseband signal; the original data of the baseband signal is corrected by an error correction algorithm to eliminate errors in the original data of the signal. According to the verification algorithm specified in the PRIME protocol, the original data of the signal after error correction is verified to determine whether the original data of the signal conforms to the protocol format; if the verification passes, the original data of the signal is converted into a PDU data packet according to the PDU format of the PRIME MAC layer protocol. The PDU data packet is reported to the application, and the signal strength RSSI value and signal-to-noise ratio SN value of the PDU are obtained at the same time. The application records the number of PDUs received and counts the RSSI value and SNR value of each PDU.

[0066] In one example, a comparison is made based on the quality and quantity of signals received at each phase, and the phase with the best quality or the largest quantity of received signals is determined as the optimal phase applicable to the current power line environment.

[0067] If the number of phases involved in the judgment is zero, the preset default phase is determined as the optimal phase;

[0068] If the number of phases involved in the judgment is one, then the phase is determined as the optimal phase;

[0069] If the number of phases involved in the judgment is greater than one, the phase obtained by the judgment rule is determined as the optimal phase.

[0070] Among them; the judgment rule is based on the signal quality and quantity values, and the priorities are average signal-to-noise ratio, average signal strength and PDU quantity from high to low;

[0071] Record the number of PDUs received from each phase, as well as the signal strength RSSI value and signal-to-noise ratio SNR value of each PDU, perform statistics and calculations, and obtain the number of PDUs, average RSSI value, and average SNR value of each phase;

[0072] Compare the average SNR values ​​of each phase; if the average SNR value of a phase is the largest, the received signal-to-noise ratio of this phase is optimal and is determined as the optimal phase; if the average SNR values ​​are the same, continue;

[0073] Further compare the average RSSI values ​​of each phase; if the average RSSI value of a phase is the largest, the received signal strength of this phase is optimal and is determined as the optimal phase; if the average SNR value and the average RSSI value are the same, continue;

[0074] Further compare the number of PDUs in each phase. If a phase has the largest average number of PDUs, the number of received signals in that phase is optimal and is determined as the optimal phase. If the average SNR value, average RSSI value, and number of PDUs are the same, the preset default phase A is determined as the optimal phase.

[0075] In this embodiment, if Figure 3 As shown, the number of PDUs received in each phase, the RSSI average value and the SNR average value are counted; the number of phases involved in the judgment is determined, and if the number is zero, the preset default phase A is determined as the optimal phase; if the number is one, the phase is determined as the optimal phase; if the number of phases involved in the judgment is greater than one, the minimum value n of the number of PDUs received in each phase is taken, and the reception records of the phases with a reception count greater than 0 are sorted from large to small according to the SNR value, and the first n records are taken to obtain their SNR average value and RSSI average value;

[0076] Compare the SNR average values ​​of each phase. If they are different, the phase with the largest SNR value is the optimal phase. If the SNR values ​​are the same, compare the RSSI average values. The phase with the largest RSSI value is the optimal phase. If the SNR average values ​​and the RSSI average values ​​are the same, compare the reception count values. The phase with the largest reception count is the optimal phase. If the reception count values ​​are also the same, determine the preset default phase A as the optimal phase. Control the phase coupling control circuit and give a phase selection signal so that the PRIME signal is transmitted at the determined optimal phase.

[0077] When implementing:

[0078] 1. Monitor and count the PRIME signals of each phase

[0079] In the PRIME network, if Figure 1 As shown, the concentrator BN node is installed on the secondary side of the low-voltage transformer, and the electric energy meter or repeater SN node is installed at various positions of the power line in the substation. Among them, the three-phase electric energy meter may be located at any position of the power line in terms of physical connection, and its adjacent parent node may be a single-phase meter and connected to its phase A, phase B or phase C. The distance between the three-phase meter and its adjacent parent node, the signal transmission impedance, and the power line environment interference are all different.

[0080] According to the phase coupling control circuit of the three-phase electric energy meter, Figure 2 As shown, the default PRIME signal coupling connection phase is phase A. By controlling the phase selection signal (relay control signal) of the circuit, combined with the PRIME signal monitoring statistical flow chart, as shown Figure 3 As shown, a transceiver chip that complies with the PRIME physical layer standard is used to receive signals from the power line environment. According to the receiver processing flow, it is identified, demodulated, error-corrected, and verified, and then reported to the application in the PRIME MAC (Media Access Control) layer protocol PDU (Protocol Data Unit) format. The application records the number of PDUs received, and their respective signal strength RSSI (Received Signal Strength Indication) values ​​and signal-to-noise ratio SNR (Signal Noise Ratio) values.

[0081] In the PRIME network, the BEACON beacon frame is a signal that is determined to exist, while other signals may appear or disappear depending on the application scenario. The BEACON beacon frame is broadcast at a certain frequency, but the frequency of transmission of different relay nodes may be different. In the PRIME v1.3.6 and v1.4 protocols;

[0082] According to the frame structure lengths defined in the two protocol versions of PRIME v1.3.6 and v1.4, the minimum transmission interval of each frame in the typical v1.3.6 protocol is about 618 milliseconds, and in v1.4 it is about 1236 milliseconds. The transmission interval ranges of the BEACON beacon frames in the two protocol versions can be calculated as follows:

[0083]

[0084] Meanwhile, considering that in field applications, signal transmission may fail due to the sometimes harsh influence of the power line communication environment, the transmission duration of three BEACON beacon frames is used as the monitoring period (cycle) of the signal.

[0085] Therefore, based on the above definition and calculation, the monitoring period of the electric energy meter equipment is: 3×39552 milliseconds=118656 milliseconds. Considering the error and the convenience of implementation, 120 seconds is taken in the program.

[0086] During the monitoring period, the PRIME signal frames received in each phase are counted, and the receiving record buffer size is a maximum of 100 records, that is, the signal frame count range is 0-100; the RSSI range is 0-130dBuV, and the SNR range is 0-50dB.

[0087] 2. Determine the optimal phase

[0088] like Figure 4 As shown, the count of PRIME signal frames received by each phase and its RSSI and SNR values ​​are checked. If the count value received by the phase is 0, it does not participate in the judgment. If the number of phases with count values ​​participating in the judgment greater than 0 is 0, the default phase A is directly taken as the optimal phase. If the number is 1, the phase is directly taken as the optimal phase. If the number is greater than 1, the minimum value of the PRIME signal count received by each phase is taken as n, and then the reception records of the phases with reception counts greater than 0 are sorted from large to small according to the SNR values, and the first n records are taken to obtain their SNR average value and RSSI average value.

[0089] The priority of the judgment conditions is SNR value, RSSI value, and receiving count value, that is, if the SNR values ​​are different, the phase of the maximum value is the optimal phase; if the SNR values ​​are the same, if the RSSI values ​​are different, the phase of the maximum value is the optimal phase; if the RSSI values ​​are also the same, the phase of the maximum value of the receiving count is the optimal phase; if the former are the same, the default phase A is directly taken as the optimal phase.

[0090] 3. Switch to the optimal phase

[0091] After obtaining the optimal phase under the current power line environment, the phase selection signal (relay control signal) of the given phase coupling control circuit is used to transmit the PRIME signal at the selected optimal phase. Then, the registration, connection establishment and corresponding communication process are started according to the PRIME network definition process. After the three-phase energy meter is disconnected from the network due to an abnormality, the coupling phase adaptive switching process is performed again to select the optimal phase again.

[0092] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for realizing phase adaptive switching of PRIME communication coupling of a three-phase electric energy meter, characterized in that: The method comprises the following steps: Acquire a phase selection signal in a power line phase coupling control circuit, wherein the phase selection signal is used to control the power line phase coupling control circuit to switch among three phases in sequence and maintain a preset time; During each phase coupling period, the physical layer protocol is used to monitor the received valid communication signals respectively, and the quality and quantity values ​​of the signals received on each phase are statistically calculated; According to the preset judgment rules, the optimal phase in the current power line environment is judged; The power line phase coupling control circuit is controlled to switch to the path corresponding to the optimal phase, and from then on, subsequent networking and communication are performed through the optimal phase.

2. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 is characterized in that: Controlling the power line phase coupling control circuit to switch among the three phases in sequence is specifically as follows: By controlling the power line phase coupling control circuit, the PRIME signal transmission line is coupled and connected to the power line phases A, B and C respectively, so that its signal is transmitted from the coupled phases.

3. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 or 2, characterized in that: The power line phase coupling control circuit comprises: The transmission signal coupling circuit includes diodes D1, D2 and transformer T1, and the input is the differential output signals TXOUTN and TXOUTP of the PRIME signal, and the output is the power lines L and N, wherein the power line L is connected to the control signal terminals PHASE_A, PHASE_B, and PHASE_C of the corresponding phase according to the control signals of each phase relay; and a three-phase relay control circuit, wherein; Phase A relay control circuit, composed of resistors R1, R2, capacitor C1, transistor Q1, diode D3 and relay J1, and relay J1 is in a normally closed state. When the control signal RELAY_A is at a high level, relay J1 is disconnected, and the power line L is disconnected from the A-phase control signal terminal PHASE_A, otherwise they are connected; Phase B relay control circuit, composed of resistors R3, R4, capacitor C2, transistor Q2, diode D4 and relay J2, and relay J2 is normally open. When the control signal RELAY_B is at a low level, relay J1 is disconnected, and the power line L is disconnected from the B-phase control signal terminal PHASE_B, otherwise they are connected. The phase C relay control circuit is composed of resistors R5 and R6, capacitor C3, transistor Q3, diode D5 and relay J3, and the relay J3 is in a normally open state. When the control signal RELAY_C is at a low level, the relay J3 is disconnected, and the power line L is disconnected from the C phase control signal terminal PHASE_C, otherwise they are connected; Through the combination of the three-phase relay control circuit and the three phase relay control signals, the three phases are coupled and connected in sequence.

4. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 is characterized in that: The physical layer protocol is used to monitor the received valid communication signals respectively, and the quality and quantity of the signals received at each phase are statistically calculated as follows: Using a transceiver chip that complies with the PRIME physical layer standard, it receives signals from the power line environment and performs identification, demodulation, error correction and verification, and then reports them to the application according to the PRIME MAC layer protocol PDU format; The application layer program records the number of PDUs received, the signal strength RSSI value, and the signal-to-noise ratio SNR value.

5. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 is characterized in that: According to the preset judgment rules, the optimal phase in the current power line environment is judged as follows: according to the signal quality and quantity values ​​received at each phase, a comparison is made to determine the phase with the best received signal quality or the largest number as the optimal phase applicable to the current power line environment.

6. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 or 5, characterized in that: If the number of phases involved in the judgment is zero, the preset default phase is determined as the optimal phase; If the number of phases involved in the judgment is one, then the phase is determined as the optimal phase; If the number of phases involved in the judgment is greater than one, the phase obtained by the judgment rule is determined as the optimal phase.

7. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 1 or 5, characterized in that: The judgment rule is based on the signal quality and quantity values, and the priorities are average signal-to-noise ratio, average signal strength and PDU quantity from high to low.

8. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 7 is characterized in that: The judgment rules are based on the signal quality and quantity values, and the priorities are from high to low: average signal-to-noise ratio, average signal strength, and PDU quantity. Specifically: Record the number of PDUs received from each phase, as well as the signal strength RSSI value and signal-to-noise ratio SNR value of each PDU, perform statistics and calculations, and obtain the number of PDUs, average RSSI value, and average SNR value of each phase; Compare the average SNR values ​​of each phase; If the average SNR value of a phase is the largest, the received signal-to-noise ratio of the phase is optimal and is determined as the optimal phase; if the average SNR values ​​are the same, continue; Further compare the average RSSI values ​​of each phase; If the average RSSI value of a phase is the largest, the received signal strength of this phase is optimal and is determined as the optimal phase; if the average SNR value and the average RSSI value are the same, continue; The number of PDUs in each phase is further compared. If the average number of PDUs in a phase is the largest, the number of received signals in this phase is optimal and is determined to be the optimal phase. If the average SNR value, average RSSI value, and number of PDUs are the same, the preset default phase A is determined to be the optimal phase.

9. The method for realizing phase adaptive switching of PRIME communication coupling of three-phase electric energy meter according to claim 7 or 8, characterized in that: The average signal-to-noise ratio and average signal strength are calculated as follows: Take the minimum value n of the number of PDUs received in each phase; sort the reception records of the phases with a reception count greater than 0 according to the SNR value from large to small; take the first n records to obtain their average SNR value and average RSSI value.

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