A fast acting distributed FA information interaction method suitable for a medium voltage carrier system

Abstract

This invention belongs to the field of power line communication technology and discloses a fast-acting distributed FA information interaction method suitable for medium-voltage carrier systems. This invention optimizes the allocation of learned frequency bands and subcarriers, minimizing both the degradation of normal communication performance and communication interference under fault conditions, ensuring normal communication during faults. In normal communication mode, a communication waiting time is added in advance. By calculating and setting the optimal waiting time, the impact of excessively long downstream node transit times on the distributed FA after a fault occurs is minimized. This ensures that the upstream carrier unit quickly interacts with the downstream unit when a fault occurs. Targeted interaction logic is proposed based on whether the downstream node at the fault point is currently communicating, and a method for calculating the communication waiting time is provided. Finally, information interaction is completed within the specified time of the distributed FA, triggering the upstream circuit breaker.

Description

Technical Field

[0001] This invention belongs to the field of power line communication technology, specifically relating to a fast-acting distributed FA information exchange method suitable for medium-voltage carrier systems. Background Technology

[0002] In recent years, with the rapid development of smart distribution networks, traditional local and centralized power distribution systems (FAs) have struggled to meet societal demands for power supply reliability. The leapfrog development of sensing and measurement control technologies, communication technologies, and computing technologies has led to the application of numerous communication and control devices in distribution automation. Distribution terminals can reliably and rapidly exchange information through peer-to-peer communication systems, enabling distributed fault location and isolation of feeders and restoration of power to non-faulty areas, avoiding the long communication and data processing delays associated with centralized control at the main station. Reducing power outage time in non-faulty sections to the second level is a key development direction for distributed FA technology in smart distribution networks.

[0003] Currently, most medium-voltage carrier communication systems adopt a master-slave mode, which requires all communication to be initiated by the master unit, with the slave unit only passively receiving. Intelligent distributed FA (Front-Agent Communication) requires all carrier units to achieve peer-to-peer communication, with each carrier unit possessing independent transmit and receive capabilities. When a fault occurs in a segment, the carrier unit that first detects the fault should proactively initiate communication to inquire about upstream and downstream information, enabling rapid disconnection of the upstream circuit breaker and thus fault isolation. In medium-voltage carrier communication systems, the transmission medium for information exchange between two carrier units is the same power line as the transmission medium for information exchange between other carrier units. Furthermore, under normal communication mode, after frequency band learning, adjacent segments may choose the same communication frequency band, leading to severe co-channel interference. Especially after the distributed FA starts, it is highly likely to continue using the frequency band configured before the fault occurred, which will increase communication interference on top of existing noise interference, severely impacting efficient information transmission.

[0004] Furthermore, intelligent distributed FA has high latency requirements, which in turn increases the latency requirements of the interaction scheme. After the distributed FA starts, if there are still ongoing communications downstream of the fault, the carrier units that must complete the information exchange will face communication waiting, and the waiting time is unpredictable. This requires the distributed FA to promptly interrupt existing downstream communications after detecting a fault, or to control the downstream communication time within a reasonable range, providing sufficient time for the distributed FA's information exchange. Summary of the Invention

[0005] To address the shortcomings or defects of the existing technologies, this invention proposes a fast-acting distributed FA information exchange method suitable for medium-voltage carrier systems. This invention utilizes frequency band allocation and subcarrier allocation schemes to eliminate co-channel interference. In normal communication mode, it increases the communication waiting time in advance to ensure that, in the event of a fault, the upstream carrier unit can quickly exchange information with the downstream unit, ultimately completing the information exchange within the specified time of the distributed FA and enabling the upstream circuit breaker to operate.

[0006] The technical solution of this invention is as follows:

[0007] A fast-acting distributed FA information exchange method suitable for medium-voltage carrier systems includes the following steps:

[0008] Step 1: The system adopts a half-duplex mode, and the management mechanism enables peer-to-peer communication between two adjacent carrier units to learn frequency bands or subcarriers;

[0009] Step 2: Frequency band or subcarrier allocation algorithm, which allocates frequency bands or subcarriers to each segment between two adjacent carrier machines. After each transmission or reception, the carrier machine waits for m, and the frequency band remains in the frequency band of the upstream carrier machine.

[0010]

[0011] ,

[0012] This indicates the transmission rate of a medium-voltage carrier communication system; This indicates the transmission time of the fault information from the FTU to the corresponding carrier unit; This indicates the size of the data packet to be transmitted, which includes two parts: first, fault information, which is related to the FTU equipment manufacturer; and second, a 12-byte protocol applicable to medium-voltage carriers. This indicates the total downlink frame transmission time of the main station's "three remote" (remote control, remote sensing, and remote telemetry) system; This indicates the size of the data packet transmitted in the total call frame, which is 28 bytes in total. It includes two parts: the original size of the total call frame data packet, which is 16 bytes; and the protocol, which is applicable to medium-voltage carriers, which is 12 bytes.

[0013] Step 3: When a fault occurs, all FTUs upstream of the fault simultaneously detect the fault and send the relevant data to the corresponding upstream carrier. Upstream carrier 1 initiates communication with upstream carrier 2, upstream carrier 2 initiates communication with upstream carrier 3, and upstream carrier 3 initiates communication with downstream carrier 4 of the fault point.

[0014] Step 4: Determine the current communication status of carrier device 4 as follows:

[0015] (4-1) If the downstream carrier 4 is not in normal communication state, the frequency band of the downstream carrier 4 is stuck in the frequency band that communicates with the upstream 3. The upstream carrier 3 sends and the downstream carrier 4 receives. At this time, the upstream carrier 2 and the upstream carrier 3 are in the sending state. The upstream carrier 2 cannot receive the information of the upstream carrier 1, and the upstream carrier 3 cannot receive the information of the upstream carrier 2.

[0016] (4-2) If the downstream carrier machine 4 of the fault point is currently in normal communication state:

[0017] (4-2-1) If the downstream carrier machine 4 is in the waiting time m and a fault occurs, then proceed to step 5;

[0018] (4-2-2) If the downstream carrier machine 4 is sending information to the destination node and a fault occurs, it waits for the transmission to finish for a time of n / 2. The downstream carrier machine 4 then enters the waiting time m again and executes step 5.

[0019] (4-2-3) If a fault occurs during the response phase of the downstream carrier 5, then after the downstream carrier 4 has finished receiving the information, the time is q, and the process will re-enter the waiting time m and execute step 5.

[0020] (4-2-4) If downstream carrier 4 is sending information to the destination node, downstream carrier 4 sends information to the carrier downstream of downstream carrier 5 through downstream carrier 5. Downstream carrier 5 is a relay. Then the waiting time of downstream carrier 4 is extended to u. If a fault occurs during the waiting time of downstream carrier 4, step (4-2-1) is executed. If a fault occurs at other times, step (4-2-3) is executed.

[0021] ,

[0022] ,

[0023] Where n is the destination node minus the sequence number of the second downstream node of the fault point, N represents the uplink data transmission time of the "three remote" data transmission, and Q represents the uplink data volume of the "three remote" data transmission.

[0024] Step 5: Downstream carrier 4 successfully receives information from upstream carrier 3 and replies to upstream carrier 3. If upstream carrier 3 does not receive a reply from downstream carrier 4 within time n, then steps 3 and 4 are repeated.

[0025] Step 6: When upstream carrier 3 receives the reply, it changes its receiving frequency band to the frequency band that it interacts with upstream carrier 2 and receives information. At this time, upstream carrier 1 and upstream carrier 2 are in a state of transmitting once every n time intervals.

[0026] Step 7: If the upstream carrier unit 3 receives the information from the upstream carrier unit 2, the upstream carrier unit 3 sends the information to the corresponding FTU to enter the action state, controls the circuit breaker to open, reports the information to the master station, and enters the power supply restoration stage in the non-faulty area.

[0027] Step 8: Downstream carrier unit 4 and downstream carrier unit 5 exchange FA information, and downstream carrier unit 4 controls the corresponding FTU to open the circuit breaker.

[0028] Step 9: After load calculation, the master station determines whether the corresponding tie switch of the downstream carrier machine 6 is closed, and sends a control command. The downstream carrier machine 6 performs the corresponding action according to the control command, and reports the information to the master station after the action is completed.

[0029] Furthermore, the frequency band or subcarrier allocation algorithm in step 2 is as follows: during the frequency band and subcarrier learning phase, the management machine counts the available frequency bands for each pair of adjacent carrier machines and sorts them according to the number and quality of subcarriers in the frequency band, and allocates carrier frequency bands according to the principle that each pair of adjacent carrier machines has an available communication frequency band.

[0030] Furthermore, in step 2, the waiting time is set to three times the transmission time to ensure that at least one communication will not fail due to a misalignment between transmission and reception time. If the upstream carrier 3 has just sent data before the downstream carrier 4 switches to a frequency band that can receive information from the upstream carrier 3, then the downstream carrier 4 will fail to receive the data, and the timeout period of the upstream carrier 3 will be [not specified]. After the timeout, upstream carrier 3 initiates communication again, and downstream carrier 4 receives the message. The timeout period is... In order to ensure that downstream carrier receiver 4 can receive the information sent by upstream carrier receiver 3 normally, .

[0031] The beneficial effects of this invention are as follows: By optimally allocating the learned frequency bands and subcarriers, it can minimize the degradation of normal communication performance and minimize communication interference under fault conditions, ensuring normal communication during faults. By calculating and setting the optimal waiting time, the impact of excessively long downstream node transit times on the distributed FA is minimized. While setting a waiting time will reduce the normal communication rate, it will still meet the communication requirements of services such as remote sensing, remote telemetry, and remote remote control. This invention can complete information exchange between critical carrier units and control FTU actions within an acceptable timeframe for the distributed FA, achieving rapid fault isolation. Attached Figure Description

[0032] Figure 1 This is a diagram illustrating the working scenario of the present invention.

[0033] Figure 2 This is a flowchart of the present invention.

[0034] Figure 3 This is a flowchart illustrating the information interaction process of this invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Example:

[0037] Based on embodiments of the present invention, the working scenario is as follows: Figure 1 As shown.

[0038] The technical solution of the present invention is as follows Figure 2 As shown:

[0039] Step 1: The management unit controls the frequency band and subcarrier learning between two adjacent carrier units (peer-to-peer communication), and sorts the frequency bands and subcarriers according to their superiority.

[0040] The reason for simultaneously learning the frequency bands and subcarriers between two adjacent carrier machines is that, in some field environments, there may be a situation where there are theoretically 8 available frequency bands, but only 3 are actually available. If there are not enough frequency bands to complete the allocation, the subcarrier's quality status is used for allocation.

[0041] Step 2: The information exchange process between carrier units is as follows Figure 3 As shown, a frequency band or subcarrier allocation algorithm is used to allocate frequency bands or subcarriers to each segment (between two adjacent carrier units) with an optimal strategy for normal communication. After each transmission or reception, the carrier unit waits for a period of m, and the frequency band remains in the communication frequency band of the upstream carrier unit before proceeding to the next step. After the carrier unit completes information exchange, the frequency band remains in the communication frequency band of the upstream carrier unit.

[0042] The allocation algorithm is as follows: During the frequency band and subcarrier learning phase, the management unit counts the available frequency bands for each pair of adjacent carrier machines and sorts them according to the number and quality of subcarriers in each frequency band. Carrier frequency bands are allocated based on the principle that each pair of adjacent carrier machines has available communication frequency bands. For example: if the available frequency bands for upstream carrier machine 1 and upstream carrier machine 2 are frequency band 1, frequency band 2, and frequency band 3, and the available frequency band for upstream carrier machine 2 and upstream carrier machine 3 is frequency band 1, then frequency band 1 is preferentially allocated to upstream carrier machine 2 and upstream carrier machine 3, and frequency band 2 is allocated to upstream carrier machine 1 and upstream carrier machine 2. If the available frequency bands for upstream carrier machine 2 and upstream carrier machine 3 are frequency band 2, frequency band 1, and frequency band 3, then frequency band 1 is allocated to upstream carrier machine 1 and upstream carrier machine 2, and frequency band 2 is allocated to upstream carrier machine 2 and upstream carrier machine 3. Frequency bands are allocated to all carrier machine pairs according to this logic. If the only available frequency band for upstream carrier machine 1 and upstream carrier machine 2 is frequency band 1, then the only available frequency band for upstream carrier machine 2 and upstream carrier machine 3 is also frequency band 1. The subcarriers in frequency band 1 will be evenly distributed. If they cannot be evenly distributed, the excess subcarriers can be randomly distributed.

[0043] The waiting time m after each transmission or reception by the carrier wave unit is:

[0044] ;

[0045] ,

[0046] This indicates the transmission rate of a medium-voltage carrier communication system; This indicates the transmission time of the fault information from the FTU to the corresponding carrier unit; This indicates the size of the data packet to be transmitted, which includes two parts: one is fault information related to the FTU equipment manufacturer, such as 64 bytes; the other is a 12-byte protocol applicable to medium-voltage carriers. This indicates the transmission time of the total downlink frames for the main station's "three remote" services; that is, the system must meet the needs of FA services as well as "three remote" services. This indicates the size of the total data packet transmitted in the overall recruitment frame, totaling 28 bytes. It includes two parts: the original size of the overall recruitment frame data packet (16 bytes) and the 12-byte protocol applicable to medium-voltage carriers. The waiting time is set to three times the transmission time, primarily to ensure that at least one communication will not fail due to a misalignment between transmission and reception time; for example: if... Then For reference time; if 3 has just sent data before 4 switches to a frequency band that can receive information from 3, then 4 will fail to receive the data. The timeout period for 3 is... After the timeout, 3 initiates communication again, and 4 receives it. The timeout period is... Therefore, disregarding other factors that could lead to communication failure, in order to ensure that information sent by 3 can be received normally by 4, ;

[0047] Step 3: When a fault occurs, all upstream FTUs simultaneously detect the fault (with differences at the microsecond or even nanosecond level, depending on the communication distance) and send relevant data to the corresponding carrier units (e.g., upstream carrier units 1, 2, and 3). After the fault occurs, the FA (Automatic Facilitator) is activated. The principle of distributed FA information exchange is that whoever detects the fault first initiates communication first. The carrier units only send query information to the downstream carrier units. Since the upstream units are guaranteed to detect the fault information, if the upstream units do not detect the fault information, then a problem with the FTU equipment is considered. However, microsecond or even nanosecond differences are normal and will not affect subsequent communication. Upstream carrier unit 1 initiates communication with upstream carrier unit 2, upstream carrier unit 2 initiates communication with upstream carrier unit 3, and upstream carrier unit 3 initiates communication with downstream carrier unit 4 at the fault point.

[0048] Step 4:

[0049] (4-1) If the downstream carrier unit 4 is not in communication mode at the fault point, then the upstream carrier unit 3 transmits and the downstream carrier unit 4 receives. At this time, both the upstream carrier unit 2 and the upstream carrier unit 3 are in transmission mode. The upstream carrier unit 2 cannot receive the information from the upstream carrier unit 1, and the upstream carrier unit 3 cannot receive the information from the upstream carrier unit 2. The signals transmitted by the upstream carrier unit 1 and the upstream carrier unit 2 may interfere with the communication between the upstream carrier unit 3 and the downstream carrier unit 4. Therefore, the frequency band allocation and subcarrier allocation strategies in steps 1 and 2 are used. The frequency band or subcarrier between each pair of carrier units will adopt a fixed mode. After the FA is started, there is no time to learn the frequency band or subcarrier. The frequency band or subcarrier after the fault has been set through the learning mechanism before the fault occurs;

[0050] (4-2) If the downstream carrier machine 4 is in communication state at the fault point at this time:

[0051] (4-2-1) If the downstream carrier machine 4 is in the waiting time m and a fault occurs, then proceed to step 5;

[0052] (4-2-2) If the downstream carrier 4 is sending information to the destination node (e.g., sending to the downstream carrier 5 without relay), and a fault occurs, then wait for the transmission to finish (time is n / 2), and the downstream carrier 4 will enter the waiting time m again and execute step 5.

[0053] (4-2-3) If a fault occurs during the response phase of downstream carrier unit 5, then wait until downstream carrier unit 4 has finished receiving the information (time is...) Once the waiting time m is entered again, step 5 will be executed.

[0054] (4-2-4) If downstream carrier 4 is sending information to the destination node (e.g., sending to downstream carrier 6 via downstream carrier 5, where downstream carrier 5 is a relay), then the waiting time of downstream carrier 4 is extended to u. If a fault occurs during the waiting time of downstream carrier 4, step (4-2-1) is executed. If a fault occurs at other times, step (4-2-3) is executed.

[0055] ,

[0056] ,

[0057] Where n represents the starting point from the second node downstream of the fault point. For example, if the destination node is 5, then n=1; if the destination node is 6, then n=2. N represents the uplink data transmission time of the "three remote" systems, and Q represents the uplink data volume of the "three remote" systems.

[0058] Step 5: If downstream carrier receiver 4 successfully receives the information from upstream carrier receiver 3, then downstream carrier receiver 4 replies to upstream carrier receiver 3; if upstream carrier receiver 3 does not receive a reply from downstream carrier receiver 4 within time n, then steps 3 and 4 are repeated.

[0059] ,

[0060] Note: This step should not be repeated too many times. The FA's total time requirement must be considered. Generally, it is set that after two consecutive retransmissions between two carrier units, no further retransmissions are needed. This places high demands on the quality of communication under fault conditions.

[0061] Step 6: If the upstream carrier 3 receives a reply, the upstream carrier 3 will change its receiving frequency band to the frequency band that interacts with the upstream carrier 2 and receive the information from the upstream carrier 2. At this time, the upstream carrier 1 and the upstream carrier 2 are in a state of transmitting once every n time intervals.

[0062] Step 7: If upstream carrier unit 3 receives information from upstream carrier unit 2, it sends a message to the corresponding FTU to enter the action state. After the circuit breaker of the corresponding FTU of upstream carrier unit 3 opens, the fault is cleared. After the information is reported to the master station, the power supply restoration phase in the non-faulty area begins. The time requirement for the power supply restoration phase in the non-faulty area is 5 seconds, which is a very ample time margin compared to fault isolation.

[0063] Step 8: Downstream carrier unit 4 and downstream carrier unit 5 exchange information to complete the opening action of the circuit breaker corresponding to downstream carrier unit 4;

[0064] Step 9: After load calculation, the master station determines whether the corresponding tie switch of the downstream carrier machine 6 is closed, and sends a control command. The downstream carrier machine 6 performs the corresponding action according to the master station's command.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention by referring to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the claims of the present invention pending approval.

Claims

1. A fast-acting distributed FA information exchange method suitable for medium-voltage carrier systems, characterized in that, Specifically, the following steps are included: Step 1: The system adopts a half-duplex mode, and the management mechanism enables peer-to-peer communication between two adjacent carrier units to learn frequency bands or subcarriers; Step 2: Frequency band or subcarrier allocation algorithm, which allocates frequency bands or subcarriers to each segment between two adjacent carrier machines. After each transmission or reception, the carrier machine waits for m, and the frequency band remains in the frequency band of the upstream carrier machine. ， This indicates the transmission rate of a medium-voltage carrier communication system; This indicates the transmission time of the fault information from the FTU to the corresponding carrier unit; This indicates the size of the data packet to be transmitted, which includes two parts: first, fault information, which is related to the FTU equipment manufacturer; and second, a 12-byte protocol applicable to medium-voltage carriers. This indicates the total downlink frame transmission time of the main station's "three remote" (remote control, remote sensing, and remote telemetry) system; This indicates the size of the data packet transmitted in the total call frame, which is 28 bytes in total. It includes two parts: the original size of the total call frame data packet, which is 16 bytes; and the protocol, which is applicable to medium-voltage carriers, which is 12 bytes. Step 3: When a fault occurs, all FTUs upstream of the fault simultaneously detect the fault and send the relevant data to the corresponding upstream carrier. Upstream carrier 1 initiates communication with upstream carrier 2, upstream carrier 2 initiates communication with upstream carrier 3, and upstream carrier 3 initiates communication with downstream carrier 4 of the fault point. Step 4: Determine the current communication status of carrier device 4 as follows: (4-1) If the downstream carrier 4 is not in normal communication state, the frequency band of the downstream carrier 4 is stuck in the frequency band that communicates with the upstream 3. The upstream carrier 3 sends and the downstream carrier 4 receives. At this time, the upstream carrier 2 and the upstream carrier 3 are in the sending state. The upstream carrier 2 cannot receive the information of the upstream carrier 1, and the upstream carrier 3 cannot receive the information of the upstream carrier 2. (4-2) If the downstream carrier machine 4 of the fault point is currently in normal communication state: (4-2-1) If the downstream carrier machine 4 is in the waiting time m and a fault occurs, then proceed to step 5; (4-2-2) If the downstream carrier machine 4 is sending information to the destination node and a fault occurs, it waits for the transmission to finish for a time of n / 2. The downstream carrier machine 4 then enters the waiting time m again and executes step 5. (4-2-3) If a fault occurs during the response phase of the downstream carrier 5, then after the downstream carrier 4 has finished receiving the information, the time is q, and the process will re-enter the waiting time m and execute step 5. (4-2-4) If downstream carrier 4 is sending information to the destination node, downstream carrier 4 sends information to the carrier downstream of downstream carrier 5 through downstream carrier 5. Downstream carrier 5 is a relay. Then the waiting time of downstream carrier 4 is extended to u. If a fault occurs during the waiting time of downstream carrier 4, step (4-2-1) is executed. If a fault occurs at other times, step (4-2-3) is executed. Where n is the destination node minus the sequence number of the second downstream node of the fault point, N represents the uplink data transmission time of "three remotes" (remote communication, remote control, and remote telemetry), and Q represents the uplink data volume of "three remotes". Step 5: Downstream carrier 4 successfully receives information from upstream carrier 3 and replies to upstream carrier 3. If upstream carrier 3 does not receive a reply from downstream carrier 4 within time n, then steps 3 and 4 are repeated. Step 6: When upstream carrier 3 receives the reply, it changes its receiving frequency band to the frequency band that it interacts with upstream carrier 2 and receives information. At this time, upstream carrier 1 and upstream carrier 2 are in a state of transmitting once every n time intervals. Step 7: If the upstream carrier unit 3 receives the information from the upstream carrier unit 2, the upstream carrier unit 3 sends the information to the corresponding FTU to enter the action state, controls the circuit breaker to open, reports the information to the master station, and enters the power supply restoration stage in the non-faulty area. Step 8: Downstream carrier unit 4 and downstream carrier unit 5 exchange FA information, and downstream carrier unit 4 controls the corresponding FTU to open the circuit breaker. Step 9: After load calculation, the master station determines whether the corresponding tie switch of the downstream carrier machine 6 is closed, and sends a control command. The downstream carrier machine 6 performs the corresponding action according to the control command, and reports the information to the master station after the action is completed.

2. The fast-acting distributed FA information interaction method suitable for medium-voltage carrier systems according to claim 1, characterized in that, The frequency band or subcarrier allocation algorithm in step 2 is as follows: During the frequency band and subcarrier learning phase, the management machine counts the available frequency bands for each pair of adjacent carrier machines and sorts them according to the number and quality of subcarriers in the frequency band. The carrier frequency band is allocated according to the principle that each pair of adjacent carrier machines has an available communication frequency band.

3. The fast-acting distributed FA information interaction method suitable for medium-voltage carrier systems according to claim 1, characterized in that, In step 2, the waiting time is set to three times the transmission time to ensure that at least one communication will not fail due to a misalignment between transmission and reception time. If the upstream carrier 3 has just sent data before the downstream carrier 4 switches to a frequency band that can receive information from the upstream carrier 3, then the downstream carrier 4 will fail to receive the data, and the timeout period of the upstream carrier 3 will be [not specified]. After the timeout, upstream carrier 3 initiates communication again, and downstream carrier 4 receives the message. The timeout period is... In order to ensure that downstream carrier receiver 4 can receive the information sent by upstream carrier receiver 3 normally, .

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