10kV power distribution system open-phase identification method and system
By collecting low-voltage side voltage and phase angle, and combining them with the exclusive discrimination logic of transformer connection group, standardized alarm information is generated and reported. This solves the problems of slow phase loss discrimination and inefficient reporting in the existing technology, and realizes rapid and accurate identification of high-voltage side phase loss and fault location and maintenance efficiency.
Patent Information
- Application Number
- CN202511215505.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2025-12-09
AI Technical Summary
Existing methods for identifying phase loss faults have slow detection rates, low reporting efficiency, and poor identification accuracy, making it difficult to quickly and accurately identify phase loss on the high-voltage side of a 10kV distribution system.
By collecting the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer, selecting the phase loss discrimination logic according to the transformer connection group, generating alarm information, encapsulating it in the power grid standard encoding format, and reporting it to the cloud master station through the communication protocol, combined with the exclusive discrimination logic of Dyn11 and Yyn0 transformers, the accurate identification and timely communication of high-voltage side phase loss are realized.
It improves the accuracy of phase loss fault identification and the timeliness of alarm information transmission, provides key basis for fault location, and enhances the operation and maintenance efficiency and intelligent monitoring capabilities of the distribution network.
Smart Images
Figure CN121090933A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power system fault detection technology, specifically to a method and system for identifying phase loss in a 10kV distribution system. Background Technology
[0002] In power distribution network operation, single-phase open circuit (phase loss) faults on 10kV medium-voltage lines are among the most common fault types. When a phase on the high-voltage side of a distribution transformer is disconnected, a significant three-phase voltage imbalance will occur on the load side, affecting power quality and equipment safety. Traditional methods often rely on analyzing the three-phase voltage imbalance on the low-voltage side of the distribution transformer to locate the fault section. However, this method usually only locates the fault area and cannot quickly determine the specific phase missing on the high-voltage side. On the other hand, distribution transformers often use Dyn11 type (delta-star connection with a neutral point without lead-out) or Yyn0 type (double-star connection with a neutral point lead-out) connection methods, and the phase angle relationship and voltage mapping characteristics of the high and low voltage sides are different. Existing technology lacks a solution for rapid phase loss identification for different connection groups. Therefore, a new technical solution is needed to fully utilize the low-voltage side voltage and phase angle information, design dedicated phase loss identification logic for Dyn11 and Yyn0 type transformers, and achieve accurate identification and timely communication of phase loss on the high-voltage side. Summary of the Invention
[0003] In view of the above-mentioned problems, the present invention is proposed.
[0004] Therefore, the technical problem solved by this invention is that existing phase loss fault identification methods have problems such as slow detection rate, low reporting efficiency, poor identification accuracy, and how to improve the efficiency of distribution network fault location and operation and maintenance.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a phase loss identification method for a 10kV power distribution system, comprising collecting the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer, selecting phase loss discrimination logic according to the connection group of the transformer; generating alarm information based on the selected phase loss discrimination logic when the phase loss discrimination logic is satisfied; encapsulating the alarm information according to the power grid standard encoding format and reporting it to the cloud master station through a communication protocol; the connection group of the transformer includes Dyn11 type connection and Yyn0 type connection, and the discrimination logic is selected according to the two connection methods.
[0006] As a preferred embodiment of the 10kV power distribution system phase loss identification method described in this invention, the selected phase loss discrimination logic includes: judging phase loss based on whether the low-voltage side phase voltage is equal to the sum of the voltages of the other two phases, and judging the phase loss level by setting an error threshold and duration, or judging phase loss based on a specific ratio of the voltage of one phase on the low-voltage side dropping to zero and the voltages of the other two phases dropping to their original values.
[0007] As a preferred embodiment of the 10kV power distribution system phase loss identification method of the present invention, the step of setting the error threshold and determining the phase loss level includes classifying the phase loss level into first-level phase loss and second-level phase loss based on the deviation between the voltage of one phase monitored on the low-voltage side and the sum of the voltages of the other two phases and the duration of the deviation.
[0008] As a preferred embodiment of the 10kV power distribution system phase loss identification method of the present invention, the phase loss judgment logic includes: for Dyn11 type connection, when the voltage relationship is continuously satisfied, it is determined that there is a phase loss fault on the high-voltage side corresponding to the voltage relationship on the low-voltage side; for Yyn0 type connection, when the voltage characteristics continuously exceed the preset error range, it is determined that a phase loss fault has occurred on the high-voltage side corresponding to the zero voltage on the low-voltage side, and an alarm message is generated.
[0009] As a preferred embodiment of the 10kV power distribution system phase loss identification method described in this invention, the alarm information includes: phase loss identifier, mapping the high-voltage side phase loss using predefined coding rules, indicating the phase of the line breakage through a specific code, phase loss level, and determining the severity level of the fault based on voltage deviation and duration.
[0010] As a preferred embodiment of the 10kV power distribution system phase loss identification method of the present invention, the power grid standard encoding format includes: using abstract syntax tags to structurally define alarm information, defining fields including phase loss identifier, phase loss level, timestamp and terminal identifier, and applying compression encoding rules to binary encode the alarm information to generate standardized message units.
[0011] As a preferred embodiment of the 10kV power distribution system phase loss identification method described in this invention, the communication protocol reporting to the cloud master station includes: constructing a three-segment topic namespace consisting of a sender identifier, a receiver identifier, and an encoding format identifier; publishing the encoded alarm information payload to a message broker server associated with the topic namespace; and using a service quality level guarantee mechanism and a session persistence mechanism to automatically resume transmission after network disconnection and reconnection.
[0012] Another objective of this invention is to provide a 10kV distribution system phase loss identification system, which can encapsulate alarm information according to the power grid standard coding format and report it to the cloud master station through a communication protocol, thus solving the problems of low efficiency in current phase loss fault identification, distribution network fault location, and operation and maintenance.
[0013] As a preferred embodiment of the 10kV distribution system phase loss identification system described in this invention, it includes: a voltage phase measurement module, a data processing module, and a communication module; the voltage phase measurement module is used by the intelligent terminal of the distribution substation to acquire the three-phase voltage values and phase-to-phase phase angle data of the low-voltage side of the distribution transformer in real time through voltage transformers and phase measurement devices, and transmits them to the subsequent processing unit through an internal bus; the data processing module is used to receive the three-phase voltage values and phase-to-phase phase angle data of the low-voltage side, select the phase loss judgment logic to perform analysis according to the pre-set transformer connection groups Dyn11 type connection and Yyn0 type connection in the system, distinguish different phase loss types and give the phase loss level; the communication module is used to encode the alarm information according to the abstract syntax markup encoding rules, generate binary message units according to the application compression encoding rules, publish the encoded message to the MQTT bus through the MQTT client, publish it to the message broker server using the message queue telemetry transmission protocol with a three-segment topic namespace, and store the alarm log locally.
[0014] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement a method for identifying phase loss in a 10kV power distribution system.
[0015] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of a phase loss identification method for a 10kV power distribution system.
[0016] The beneficial effects of this invention are as follows: This invention provides a 10kV power distribution system phase loss identification method that collects the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer, selects the corresponding phase loss discrimination logic according to the connection group of the transformer, and accurately identifies the phase of the high-voltage side phase loss fault by adapting the exclusive discrimination logic to different transformer connection groups. It improves the timeliness and reliability of fault information reporting based on a standardized communication mechanism. Based on the selected phase loss discrimination logic, an alarm message is generated when the phase loss discrimination logic is met. By generating alarm messages containing accurate phase loss identifiers and multi-level phase loss severity, it provides key evidence for fault location for operation and maintenance personnel. It achieves efficient transmission of alarm information by adapting to standardized communication protocols, encapsulates the alarm information according to the power grid standard encoding format, and reports it to the cloud master station through the communication protocol. Encapsulating the alarm information according to the power grid standard encoding format ensures the uniformity of data syntax parsing and communication compatibility. Combined with a topic naming mechanism for accurate routing of alarm information and efficient and reliable reception by the cloud master station, this invention achieves better results in terms of phase loss fault identification accuracy, alarm information transmission timeliness, and fault location reliability. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 The first embodiment of the present invention provides an overall flowchart of a phase loss identification method for a 10kV power distribution system.
[0019] Figure 2 This is a software system design diagram for a phase loss identification method for a 10kV power distribution system provided in the second embodiment of the present invention. Detailed Implementation
[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0021] Example 1, referring to Figure 1 As an embodiment of the present invention, a method for identifying phase loss in a 10kV power distribution system is provided, comprising:
[0022] S1: Collect the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer, and select the phase loss detection logic according to the connection group of the distribution transformer.
[0023] Furthermore, the phase loss detection logic includes determining a phase loss based on whether the low-voltage side phase voltage is equal to the sum of the other two phase voltages, and setting an error threshold and duration to determine the phase loss level, or determining a phase loss based on a specific ratio of one low-voltage side phase voltage dropping to zero and the other two phase voltages dropping to their original values.
[0024] It should be noted that setting the error threshold and duration to determine the phase loss level includes classifying the phase loss level into first-level phase loss and second-level phase loss based on the deviation between the voltage of one phase monitored on the low-voltage side and the sum of the voltages of the other two phases, as well as the duration of the deviation.
[0025] It should also be noted that the intelligent terminal installed in the distribution transformer area collects the three-phase voltage values and phase-to-phase phase angles in real time from the low-voltage side through voltage transformers and phase measurement devices. The processing module selects the corresponding phase loss judgment logic according to the transformer connection group preset in the system, based on the connection group of the distribution transformer, Dyn11 type connection and Yyn0 type connection.
[0026] It should also be noted that by collecting the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer in real time, and combining them with the preset transformer connection group, the system can accurately select the phase loss judgment logic for different wiring methods. This solves the problem that traditional detection methods are difficult to adapt to different transformer connection groups, which can lead to misjudgment or missed judgment of phase loss. It improves the accuracy of detection, reduces the risk of misjudgment or missed judgment due to differences in connection groups, and provides maintenance personnel with more accurate information on the severity of the fault based on the magnitude and duration of the deviation. This enhances the level of intelligence and strengthens the intelligent monitoring and maintenance capabilities of the distribution network.
[0027] S2: Based on the selected phase loss detection logic, an alarm message is generated when the phase loss detection logic is satisfied.
[0028] Furthermore, the phase loss detection logic includes, for Dyn11 type connection, when the voltage relationship is continuously satisfied, determining that there is a phase loss fault on the high-voltage side corresponding to the voltage relationship on the low-voltage side; for Yyn0 type connection, when the voltage characteristics continuously exceed the preset error range, determining that there is a phase loss fault on the high-voltage side corresponding to the zero voltage on the low-voltage side, and generating alarm information.
[0029] It should be noted that for the Dyn11 type distribution transformer, the processing module detects whether the voltage of any phase on the low-voltage side is equal to the sum of the voltages of the other two phases. If it detects that phase B is approximately equal to phase A plus phase C and the deviation is within ±30V for more than 1 minute, it can be determined that phase A on the high-voltage side is disconnected and a first-level phase loss alarm is generated. When the deviation expands to ±40V and lasts for more than 2 minutes, it can be determined as a second-level phase loss. If it detects that phase C is approximately equal to phase A plus phase B, it can be determined that phase B on the high-voltage side is disconnected. If it detects that phase A is approximately equal to phase B plus phase C, it can be determined that phase C on the high-voltage side is disconnected. Different phase loss types are distinguished and the phase loss level is given.
[0030] For Yyn0 type distribution transformers, the processing module monitors whether the voltage of a certain low-voltage phase drops to near 0. If it detects that the voltage of phase A is approximately equal to 0, and the voltages of phases B and C are both approximately 0.866 times the original voltage, the voltage of the two phases drops by about 13.4%, the deviation is within the preset 12V, and it lasts for more than 1 minute, it is determined that the high-voltage side phase A is disconnected. The situation is similar for the disconnection of phase B or phase C. In the case of phase disconnection, the voltage of the low-voltage side phase disconnection is almost zero, and the voltages of the other two phases are lower than the normal value. The phase loss of Yyn0 type transformers is accurately identified through the proportional relationship.
[0031] It should be noted that the alarm information includes the phase identification of the lost phase, which is mapped to the phase of the high-voltage side using predefined coding rules. The phase of the broken wire is represented by a specific code, the phase loss level, and the severity level of the fault is determined based on the voltage deviation and duration.
[0032] It should also be noted that, combined with phase angle information for auxiliary judgment, when a phase loss occurs, since the voltage of a certain phase becomes 0, the phase angle distribution of the three phases on the low-voltage side changes significantly. The processing module can set a phase angle offset threshold to further verify the phase loss time and filter instantaneous interference. Once the phase loss condition is met, the processing module generates a phase loss alarm message, including the phase identification of the broken wire (code "1" indicates phase A) and the phase loss level, including first-level phase loss and second-level phase loss.
[0033] It should also be noted that by designing differentiated low-voltage side voltage characteristic detection logic for Dyn11 and Yyn0 transformers, setting precise voltage deviation thresholds and duration conditions, and combining phase angle-assisted verification and defining alarm coding rules, the technical problem of difficulty in quickly and accurately identifying phase and severity levels of high-voltage side phase-loss faults in distribution networks is solved. This improves the automation and high-precision identification of high-voltage side phase-loss faults in distribution transformers, real-time assessment of fault levels, and provides key basis for rapid fault location and handling in the power grid.
[0034] S3: Encapsulate alarm information according to the power grid standard encoding format and report it to the cloud master station through the communication protocol.
[0035] Furthermore, the power grid standard encoding format includes using abstract syntax tags to structurally define alarm information, defining fields including phase loss identifier, phase loss level, timestamp and terminal identifier, and applying compression encoding rules to encode the alarm information into binary to generate standardized message units.
[0036] It should be noted that the communication protocol reporting to the cloud master station includes constructing a three-segment topic namespace with sender identifier, receiver identifier, and encoding format identifier; publishing the encoded alarm information payload to the message broker server associated with the topic namespace; and using a service quality level guarantee mechanism and session persistence mechanism to automatically resume transmission after network disconnection and reconnection.
[0037] It should also be noted that the communication module encapsulates the data according to the power grid standard, uses ASN.1 abstract syntax for structured definition, and encodes it using the A-XDR encoding rule. The communication module publishes the encoded message to the MQTT bus through the MQTT client. The subject format is "terminal identifier / master identifier / A-XDR", with an attached encoded payload, to achieve reliable reporting to the cloud master station. The message data unit may contain fields such as start flag, message priority, and message sequence number to meet the system's communication specifications.
[0038] The voltage phase measurement module sends the measured electrical parameters to the data processing module via the internal bus. The data processing module runs an embedded program and periodically executes the phase loss identification logic. Once a phase loss fault is identified, it immediately notifies the communication module. The communication module assists in sending the alarm information to the cloud master station via wireless or wired network, and at the same time stores the alarm log locally for maintenance personnel to query.
[0039] It should also be noted that by encapsulating alarm information using the power grid standard encoding format and designing a three-segment topic namespace transmission mechanism based on the MQTT protocol, the technical problems of standardization, efficient and reliable transmission of phase loss alarm information in the distribution network and seamless connection to the cloud are solved. This achieves the technical effects of structured alarm information, efficient transmission, and reliable communication, thereby improving the efficiency and reliability of remote monitoring and response to distribution network faults.
[0040] Example 2, refer to Figure 2 As an embodiment of the present invention, a method for identifying phase loss in a 10kV power distribution system is provided. To verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculations and simulation experiments.
[0041] First, install the intelligent integrated terminal for the distribution area and connect it to the outgoing line side of the transformer. Run the 10kV distribution system phase loss identification method and system within the terminal. Use a fuse to disconnect one phase on the 10kV side. Check the internal printouts and monitoring center interface of the terminal to verify the accurate location of the phase loss signal and the phase type. The process is as follows: Figure 2 As shown, the three-phase voltage values and phase-to-phase phase angle data of the low-voltage side of the distribution transformer are obtained through voltage transformers and phase measurement devices. The corresponding criterion algorithm is called according to the preset transformer connection group. The voltage amplitude criterion result is verified by combining the phase angle offset. When the criterion is continuously satisfied, the structured alarm information containing the high-voltage side phase failure code, phase loss level, timestamp and terminal equipment identifier is output. The communication module encapsulates the data according to the power grid standard and reports it to the cloud master station. At the same time, the alarm log is stored locally. The experimental results are shown in Table 1.
[0042] Table 1 Fault Information Table
[0043]
[0044] According to the results in Table 1, after generating alarm information, it is pushed to the monitoring center via MQTT through A-XDR encoding. Our invention is based on the idea of "judging the high side from the low side". It collects the three-phase voltage and phase angle data of the low-voltage side of the transformer, and combines the vector characteristics of different connection groups of Dyn11 and Yyn0 transformers. It uses corresponding criteria to identify the phase loss, which can quickly and accurately identify the phase loss type and phase, and promptly transmit the phase loss alarm to the monitoring center, thus improving the timeliness and reliability of fault location in the distribution network.
[0045] Example 3, an embodiment of the present invention, provides a 10kV power distribution system phase loss identification system, including a voltage phase measurement module, a data processing module, and a communication module.
[0046] Among them, the voltage phase measurement module is used by the intelligent terminal of the distribution transformer area to obtain the three-phase voltage value and phase-to-phase phase angle data of the low-voltage side of the distribution transformer in real time through the voltage transformer and the phase measurement device, and transmit it to the subsequent processing unit through the internal bus.
[0047] The data processing module receives the three-phase voltage values and phase-to-phase phase angle data on the low-voltage side. Based on the pre-set transformer connection groups Dyn11 and Yyn0 in the system, it selects the phase loss judgment logic to perform analysis, distinguishes different phase loss types, and gives the phase loss level.
[0048] The communication module encodes alarm information according to the abstract syntax markup encoding rules, generates binary message units according to the application compression encoding rules, publishes the encoded message to the MQTT bus through the MQTT client, publishes it to the message broker server in a three-segment topic namespace using the message queue telemetry transmission protocol, and stores alarm logs locally.
Claims
1. A method for identifying phase loss in a 10kV power distribution system, characterized in that, include: Collect the three-phase voltage values and phase-to-phase phase angles on the low-voltage side of the transformer, and select the phase loss detection logic according to the connection group of the distribution transformer; Based on the selected phase loss detection logic, an alarm message is generated when the phase loss detection logic is met; The alarm information is encapsulated according to the power grid standard encoding format and reported to the cloud master station through the communication protocol; The connection groups of the distribution transformer include Dyn11 type connection and Yyn0 type connection, and the discrimination logic is selected according to the two connection methods.
2. The method for identifying phase loss in a 10kV power distribution system as described in claim 1, characterized in that: The selected phase loss discrimination logic includes, Phase loss can be determined by whether the low-voltage side phase voltage is equal to the sum of the other two phase voltages, and the phase loss level can be determined by setting an error threshold and duration, or by determining a phase loss based on a specific ratio of one phase voltage on the low-voltage side dropping to zero and the other two phase voltages dropping to their original values.
3. The method for identifying phase loss in a 10kV power distribution system as described in claim 2, characterized in that: The determination of the phase loss level based on the set error threshold and duration includes, Based on the deviation between the voltage of one phase and the sum of the voltages of the other two phases monitored on the low-voltage side, as well as the duration of the deviation, the phase loss level is divided into first-level phase loss and second-level phase loss.
4. The method for identifying phase loss in a 10kV power distribution system as described in claim 1, characterized in that: The missing phase discrimination logic includes, For the Dyn11 type connection, when the voltage relationship is continuously satisfied, it is determined that there is a phase failure on the high-voltage side corresponding to the voltage relationship on the low-voltage side. For the Yyn0 type connection, when the voltage characteristics continuously exceed the preset error range, it is determined that there is a phase failure on the high-voltage side corresponding to the zero voltage on the low-voltage side, and an alarm message is generated.
5. The method for identifying phase loss in a 10kV distribution system as described in claim 1 or 4, characterized in that: The alarm information includes, The phase loss identifier uses a predefined coding rule to map the phase loss on the high-voltage side. A specific code indicates the phase that has broken the line and the level of phase loss. The severity level of the fault is determined based on the voltage deviation and duration.
6. The method for identifying phase loss in a 10kV power distribution system as described in claim 1, characterized in that: The power grid standard coding format includes, The alarm information is structured using abstract syntax tags. The defined fields include phase loss identifier, phase loss level, timestamp, and terminal identifier. The alarm information is binary encoded using compression encoding rules to generate standardized message units.
7. The method for identifying phase loss in a 10kV power distribution system as described in claim 1, characterized in that: The communication protocol reported to the cloud master station includes, A three-part topic namespace is constructed, consisting of sender identifier, receiver identifier, and encoding format identifier. The encoded alarm information payload is published to the message broker server associated with the topic namespace. A service quality level guarantee mechanism and a session persistence mechanism are used to automatically resume transmission after network disconnection and reconnection.
8. A phase loss identification system for a 10kV distribution system, employing the phase loss identification method for a 10kV distribution system as described in any one of claims 1 to 7, characterized in that: Includes a voltage phase measurement module, a data processing module, and a communication module; The voltage phase measurement module is used by the intelligent terminal of the distribution transformer area to obtain the three-phase voltage value and phase phase angle data of the low-voltage side of the distribution transformer in real time through the voltage transformer and the phase measurement device, and transmit it to the subsequent processing unit through the internal bus. The data processing module is used to receive the three-phase voltage values and phase-to-phase phase angle data on the low-voltage side, and select the phase loss judgment logic to perform analysis according to the transformer connection group Dyn11 type connection and Yyn0 type connection preset in the system, distinguish different phase loss types and give the phase loss level. The communication module is used to encode alarm information according to the abstract syntax markup encoding rules, generate binary message units according to the application compression encoding rules, publish the encoded message to the MQTT bus through the MQTT client, publish it to the message broker server in a three-segment topic namespace using the message queue telemetry transmission protocol, and store alarm logs locally.
9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the 10kV power distribution system phase loss identification method according to any one of claims 1 to 7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the 10kV power distribution system phase loss identification method according to any one of claims 1 to 7.