Intelligent diagnosis and analysis system for line loss of transformer area based on electrical sensor

Abstract

The present application relates to line detection technical field, disclose a kind of intelligent diagnosis analysis system of line loss of transformer area based on electrical sensor, including electrical sensor and diagnostic processor.Electrical sensor corresponding to the measurement position of transformer area feeder, obtain the phase voltage and phase active power of A, B, C three-phase in the same measurement period;Diagnostic processor establishes the corresponding relationship of power supply connection sequence, measurement position, measurement section and three-phase phase, according to the equivalent difference of section input active power and section output active power to form section active loss representation, determine the measurement section to be attributed, and form front side phase voltage difference relative order, middle ratio relative order and rear side phase voltage difference relative order in three continuous measurement positions.When the relative order of the same phase appears only on one side and is unique, the side measurement section is determined as line loss abnormal measurement section, and the abnormal phase is determined, which is used for transformer area feeder field operation positioning.

Description

Technical Field

[0001] This invention relates to the field of line testing technology, and more specifically, to an intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors. Background Technology

[0002] Line loss troubleshooting for low-voltage transformer feeders typically relies on main meters, sub-meters, power acquisition terminals, and on-site inspection records. In actual operation and maintenance, transformer feeders have numerous branches and connection points, and three-phase loads vary significantly over time. A single total line loss indicator can only suggest an anomaly in the transformer area, but it's difficult to directly pinpoint the specific section or phase of the line where the anomaly is located. On-site personnel often need to check joints, meter boxes, branch lines, and user-side loads segment by segment along the feeder, resulting in a heavy workload and susceptibility to variations in sampling periods, three-phase load fluctuations, and changes in branch power supply relationships.

[0003] Existing transformer monitoring systems can acquire data such as voltage, current, power, and energy. However, in many applications, line loss assessment still relies heavily on the difference between total incoming and outgoing power, threshold alarms, or empirical rules. For anomalies caused by a specific measurement section or phase, simply checking the section's input active power, output active power, or phase voltage changes at a single measurement location is usually insufficient to accurately pinpoint the anomaly to its location on-site. Especially when there are three-phase load imbalances, feeder end voltage fluctuations, and branch load changes, the relationship between phase voltage and phase active power needs to be analyzed in conjunction with the measurement location and power supply direction. Otherwise, normal load changes may be mistaken for abnormal line losses, or only a broad scope for investigation may be provided.

[0004] Therefore, line loss diagnosis in transformer substations requires a processing method that is closer to the field measurement link: using phase voltage and phase active power obtained by electrical sensors at different measurement locations during the same measurement period as input, loss characterization at the measurement section level is formed under the power supply connection sequence of the transformer substation feeder. Then, combined with the voltage difference sequence between adjacent measurement locations and the load relationship of intermediate measurement locations, the diagnostic processor is assisted in locating the anomaly to the specific measurement section and the abnormal phase, providing a basis for field personnel to narrow down the scope of investigation. Summary of the Invention

[0005] This invention provides an intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors, which solves the technical problems mentioned in the background art.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0007] The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors includes electrical sensors and a diagnostic processor. The electrical sensors correspond to the measurement positions of the transformer substation feeder and obtain the three-phase voltages and three-phase active power of A, B, and C during the same measurement period. The diagnostic processor establishes the correspondence between the power supply connection sequence, measurement location, physical measurement section and three-phase phase. It forms the active power loss characterization of the section by the equivalent difference between the active power input and the active power output of the section, and determines the physical measurement section that meets the preset electrical criteria as the physical measurement section to be assigned. For two physical measurement segments that include the physical measurement segment to be assigned and are connected end to end, select three consecutive measurement positions. With the middle measurement position as a common reference, form the relative order of the phase voltage difference of the previous measurement position relative to the middle measurement position, form the relative order of the phase ratio of the phase active power to the phase voltage of the middle measurement position, form the relative order of the phase voltage difference of the middle measurement position relative to the next measurement position, and maintain the phase identity consistent correspondence. When the relative order migration of the same phase occurs only between the relative order of the intermediate ratio and the relative order of the phase voltage difference on one side and is unique, the physical measurement section corresponding to that side is identified as the physical measurement section with abnormal line loss, and the phase is identified as the abnormal phase.

[0008] Compared with the prior art, the present invention has the following substantial features and significant progress: This system is based on the phase voltage and phase active power obtained by electrical sensors at various measurement locations along the feeder in the distribution area. It enables the diagnostic processor to process the three-phase measurement results during the same measurement period according to the power supply connection sequence, measurement location, measurement section, and phase correspondence. By forming a section active power loss characterization through the equivalent difference between the section input active power and the section output active power, and combining the relative order migration relationship between the relative order of the front phase voltage difference, the relative order of the intermediate ratio, and the relative order of the rear phase voltage difference, the anomaly judgment is further refined from the distribution area feeder range to the abnormal line loss measurement section and abnormal phase. This provides a clearer location basis for low-voltage distribution area on-site troubleshooting, branch path verification, phase inspection, and maintenance dispatch, reducing the problem of overly broad troubleshooting scope caused by relying solely on the total meter line loss or single-point power data. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the structure and diagnostic relationship of the intelligent diagnostic analysis system for transformer substation line loss based on electrical sensors according to the present invention. Detailed Implementation

[0010] The following description is provided in conjunction with the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the invention; those skilled in the art can make equivalent substitutions or combinations for the specific implementations.

[0011] This implementation relates to the field of line detection, specifically to an intelligent diagnostic analysis system for transformer substation line losses based on electrical sensors. Low-voltage transformer substation feeders typically connect multiple measurement locations along the power supply direction, forming physical measurement sections identifiable by on-site maintenance personnel. Since three-phase loads fluctuate with changes in user-side power consumption during the same measurement period, relying solely on the total line loss of the substation or the power variation at a single measurement location is usually insufficient to definitively attribute an anomaly to a specific physical measurement section or phase. This implementation uses the three-phase phase voltage and three-phase active power during the same measurement period as the diagnostic basis, enabling the diagnostic results to correspond to the power supply connection sequence, measurement location, physical measurement section, and three-phase phase.

[0012] See Figure 1 The intelligent diagnostic analysis system for transformer substation line loss based on electrical sensors in this embodiment includes an electrical sensor 200 and a diagnostic processor 500. The electrical sensor 200 is set at measurement positions 300 corresponding to the feeder line 100 in the transformer substation, and is used to obtain the three-phase voltages and active power of phases A, B, and C during the same measurement period. The diagnostic processor 500 is used to establish the correspondence between the power supply connection sequence, measurement positions 300, physical measurement sections 400, and the three-phase types, and to form a section active power loss characterization based on the equivalent difference between the section input active power and the section output active power. The diagnostic processor 500 is also used to form the relative order of the front phase voltage difference, the relative order of the intermediate ratio, and the relative order of the rear phase voltage difference within three consecutive measurement positions 300, and to determine the abnormal physical measurement section and abnormal phase based on the relative order of the same phase type.

[0013] This embodiment utilizes electrical measurement results obtained by electrical sensors 200 to perform diagnosis under the existing power supply connection sequence of the feeder 100 in the transformer substation. The diagnostic processor 500 performs processing that, under the condition that it can obtain phase voltage and phase active power and that the data from different measurement locations 300 correspond to the same measurement time period, can complete the corresponding diagnosis of the physical measurement section 400 and the three phases.

[0014] Furthermore, the corresponding relationships between the power supply connection sequence, measurement locations, physical measurement sections, and three-phase phases are established, as follows: See Figure 1The distribution area feeder 100 extends along the power supply direction, and multiple electrical sensors 200 correspond to different measurement positions 300. The correspondence establishment unit 510 in the diagnostic processor 500 reads or receives the power supply connection sequence of the distribution area feeder 100 and assigns each electrical sensor 200 to a measurement position 300. The power supply connection sequence is used to indicate the sequential relationship between measurement positions 300 when electrical energy is transferred from the power supply side to the load side. The measurement position 300 is used to indicate the physical position of the electrical sensor 200 on the distribution area feeder 100. The physical measurement section 400 is used to indicate the line section between adjacent measurement positions 300 that needs to be classified for line loss. The three-phase identification is used to maintain the consistent identity of phases A, B, and C between each measurement position 300.

[0015] When establishing a correspondence, the correspondence establishment unit 510 defines a physical measurement segment 400 as the line between two adjacent measurement positions 300 that does not contain any other measurement positions 300 in between. A physical measurement segment 400 has a power supply side measurement position 300 and a load side measurement position 300. The power supply side measurement position 300 is the side of the physical measurement segment 400 that is closer to the power source in the power supply connection sequence, and the load side measurement position 300 is the side of the physical measurement segment 400 that is farther away from the power source in the power supply connection sequence.

[0016] When the power supply path branches at measurement location 300, the correspondence establishment unit 510 determines the subsequent physical measurement segment 400 according to the physical connection sequence of each actual branch. An actual branch is an existing power supply path branching off from the transformer feeder 100 after measurement location 300. The correspondence establishment unit 510 maintains the sequential order of measurement locations 300 within each actual branch and determines the line between two adjacent measurement locations 300 within the same actual branch as the subsequent physical measurement segment 400.

[0017] In this embodiment, the correspondence between the three phases is maintained as follows: A corresponds to phase A, B corresponds to phase B, and C corresponds to phase C. The correspondence establishment unit 510 binds the three-phase voltages and active power of phases A, B, and C obtained at each measurement location 300 to the same three-phase phase.

[0018] Furthermore, the phase voltage and phase active power for the same measurement period are obtained, as follows: See Figure 1 Electrical sensor 200 is installed at measurement position 300 to obtain the phase voltages and active power of phases A, B, and C. The phase voltage is the measured voltage of each phase at the corresponding measurement position 300, denoted as... Phase active power is the active power measured at the corresponding measurement location 300 for each phase, denoted as . In the main text, phase voltage and phase active power are used as fixed technical terms; in the formulas, and It is used only as a symbol for phase voltage and phase active power.

[0019] The electrical sensor 200 can directly obtain the phase voltage through the conventional voltage measurement channel and the phase active power through the conventional active power measurement channel. The conventional voltage measurement channel is used to obtain the voltage measurement of each relative neutral point or equivalent reference point at the measurement position 300; the conventional active power measurement channel is used to obtain the active power measurement corresponding to that phase at the measurement position 300.

[0020] The phase voltage and phase active power acquired by the electrical sensor 200 should correspond to the same measurement period. The same measurement period means that the electrical measurement results at different measurement locations 300 can reflect the spatial distribution of the feeder 100 in the same operating state. In specific implementation, the diagnostic processor 500 can receive the phase voltage and phase active power uploaded from each measurement location 300 in the same sampling round; alternatively, after the electrical sensor 200 completes the measurement in the same sampling round, the diagnostic processor 500 reads the data according to the sampling round identifier. Regardless of the conventional data reception method used, the phase voltage and phase active power at different measurement locations 300 correspond to the same measurement period.

[0021] In the same sampling round, if any measurement location 300 lacks the phase voltage or phase active power of any phase, the diagnostic processor 500 will not use the data from that sampling round to determine the abnormal physical measurement section and abnormal phase of the line loss. This processing is used to ensure that the relative order of the preceding phase voltage difference, the relative order of the intermediate ratio, and the relative order of the following phase voltage difference are all formed by complete A, B, and C three-phase data. Since the relative order migration requires comparing the position of the same phase in the three relative orders, the absence of the phase voltage or phase active power of any phase will disrupt the consistent correspondence of the three phases; therefore, this sampling round will not participate in this diagnosis.

[0022] After receiving the phase voltage and phase active power from the electrical sensor 200, the diagnostic processor 500 records each data item as a combination of measurement location 300, three-phase type, and the same measurement time period. This combination ensures that the input active power of subsequent sections, the output active power of sections, the relative order of the preceding phase voltage difference, the relative order of intermediate ratios, and the relative order of the following phase voltage difference can all be traced back to the same measurement location 300 and the same three-phase type. The recording method can be an array, a mapping relationship, or a data object internal to the diagnostic processor 500, as long as the correspondence between the power supply connection sequence, measurement location 300, physical measurement section 400, and three-phase type is maintained.

[0023] The third step is to characterize the section's input active power, section's output active power, and section's active power loss. See Figure 1 The active power loss characterization and determination unit 520 in the diagnostic processor 500 processes each physical measurement section 400. For any physical measurement section 400, the section input active power is the sum of the active power of phases A, B, and C at measurement position 300 on the power supply side of the physical measurement section 400, and the section output active power is the sum of the active power of phases A, B, and C at measurement position 300 on the load side of the physical measurement section 400. Both the section input active power and the section output active power are formed by the phase active power during the same measurement period, thus enabling them to represent the active power relationship between the two ends of the physical measurement section 400 under the same operating condition.

[0024] When multiple actual branches are connected to the load-side measurement position 300 of the physical measurement section 400, the section active power loss characterization and determination unit 520 determines the sum of the three-phase active power (A, B, and C) of each actual branch load side, and sums the three-phase active power of each actual branch as the section output active power. This process ensures that the section output active power covers all branch loads actually received by the load side of the physical measurement section 400, rather than using only the phase active power of one actual branch. Therefore, the equivalent difference between the section input active power and the section output active power corresponds to the overall active power relationship at both ends of the physical measurement section 400.

[0025] The active power loss characterization of a section is formed by the equivalent difference between the active power input and output of the section. This equivalent difference is based on the input and output active power of the section under the same measurement period, the same physical measurement section 400, and the same active power unit, representing the active power difference relationship between the power supply side and the load side of the physical measurement section 400. The active power loss characterization of a section can be expressed as an active power difference or as the section line loss ratio formed by the active power difference relative to the section input active power. Regardless of the representation method, the active power loss characterization of a section points to the same physical measurement section 400 and serves as the basis for determining the physical measurement section to be assigned.

[0026] In one specific implementation, the preset electrical criteria are saved by the diagnostic processor 500 before performing the diagnosis as comparison conditions corresponding to the data type of the active power loss characterization of the section. When the active power loss characterization of the section is expressed as an active power difference, the preset electrical criteria adopt the allowable difference condition under the same active power unit; when the active power loss characterization of the section is expressed as a section line loss ratio, the diagnostic processor 500 normalizes the active power loss characterization of the section to the section line loss ratio, and when the section line loss ratio exceeds the allowable line loss ratio of electrical technology, the corresponding physical measurement section 400 is determined as a candidate physical measurement section for line loss, and the candidate physical measurement section for line loss is designated as the physical measurement section to be assigned. Thus, the input of the preset electrical criteria is the active power loss characterization of the section, and the output is the judgment result of whether to determine the corresponding physical measurement section 400 as the physical measurement section to be assigned.

[0027] In the formula, Indicates the measurement section number The corresponding physical measurement section 400 shows the section line loss ratio, which is a dimensionless ratio. This represents the phase index, and its value is... , and , Indicates the measurement section number The corresponding physical measurement section 400 is located at measurement position 300 on the power supply side, and the phase index is... Corresponding to the active power of other phases, Indicates the measurement section number The corresponding physical measurement section 400 is in the branch sequence number Corresponding load-side actual branch and phase index The active power of the corresponding phase.

[0028] After the active power loss characterization and determination unit 520 determines the physical measurement section to be assigned, it hands over the physical measurement section to be assigned to the relative order migration diagnosis unit 530 for further three-phase phase assignment.

[0029] Furthermore, three relative sequences are formed around the three consecutive measurement positions, as follows: See Figure 1The relative sequence migration diagnostic unit 530 selects three consecutive measurement positions 300 for two physical measurement segments 400 that include the physical measurement segment to be assigned and are connected end-to-end. The three consecutive measurement positions 300 are, in order of power supply connection, the preceding measurement position 300, the intermediate measurement position 300, and the following measurement position 300. The preceding measurement position 300 and the intermediate measurement position 300 form the preceding physical measurement segment 400, and the intermediate measurement position 300 and the following measurement position 300 form the following physical measurement segment 400. The intermediate measurement position 300 is the common reference for both the preceding and following physical measurement segments 400.

[0030] Using the intermediate measurement position 300 as a common reference is a crucial spatial constraint for assigning the physical measurement section 400 in this embodiment. The relative order of the phase voltage differences on the front side is formed by the phase voltage difference between the previous measurement position 300 and the intermediate measurement position 300, the relative order of the phase voltage differences on the rear side is formed by the phase voltage difference between the intermediate measurement position 300 and the next measurement position 300, and the relative order of the intermediate ratios is formed by the ratio of the phase active power to the phase voltage at the intermediate measurement position 300. All three relative orders are established around the intermediate measurement position 300, so the positional changes of the same phase between the front, middle, and rear sides can be mapped to one side of the intermediate measurement position 300.

[0031] The relative order of the front-side phase voltage differences indicates the magnitude relationship of the phase voltage differences of phases A, B, and C in the front-side physical measurement section 400. Specifically, the relative order migration diagnosis unit 530 obtains the phase voltages of phases A, B, and C at the previous measurement position 300 and the intermediate measurement position 300 during the same measurement period, and performs a calculation by subtracting the phase voltage of the intermediate measurement position 300 from the phase voltage of the previous measurement position 300 for the same phase, thereby obtaining the phase voltage difference corresponding to that phase. Subsequently, the relative order migration diagnosis unit 530 sorts the phase voltage differences from largest to smallest to form the relative order of the front-side phase voltage differences.

[0032] The relative order of intermediate ratios represents the magnitude relationship between the ratios of phase active power to phase voltage for phases A, B, and C at the intermediate measurement position 300. The ratio of phase active power to phase voltage characterizes the relationship between the load of each phase and the phase voltage at the intermediate measurement position 300. The relative order migration diagnostic unit 530 obtains the phase active power and phase voltage of phases A, B, and C at the intermediate measurement position 300 during the same measurement period, and forms the ratio of phase active power to phase voltage for each phase. Then, it sorts the ratios from largest to smallest to form the relative order of intermediate ratios.

[0033] The relative order of the phase voltage differences indicates the magnitude relationship of the phase voltage differences of phases A, B, and C in the rear physical measurement section 400. Specifically, the relative order migration diagnosis unit 530 obtains the phase voltages of phases A, B, and C at the intermediate measurement position 300 and the subsequent measurement position 300 during the same measurement period, and performs a calculation by subtracting the phase voltage of the subsequent measurement position 300 from the phase voltage of the intermediate measurement position 300 for the same phase, thereby obtaining the phase voltage difference corresponding to that phase. Subsequently, the relative order migration diagnosis unit 530 sorts the phase voltage differences from largest to smallest to form the relative order of the rear phase voltage differences.

[0034] The common object of the relative order of the front-side phase voltage difference, the relative order of the intermediate ratio, and the relative order of the rear-side phase voltage difference is the three phases A, B, and C. After forming the three columns of relative orders, the relative order migration diagnostic unit 530 maintains a consistent correspondence between the phase identities; that is, phase A always corresponds to phase A in the three columns of relative orders, phase B always corresponds to phase B in the three columns of relative orders, and phase C always corresponds to phase C in the three columns of relative orders. This consistent correspondence allows the diagnostic processor 500 to identify whether the relative order migration of the same phase only occurs between the relative order of the intermediate ratio and the relative order of the phase voltage difference on one side.

[0035] In one specific embodiment, the diagnostic processor 500 establishes a three-phase phase migration diagram. The three-phase phase migration diagram uses three columns to represent the relative order of the front-side phase voltage difference, the relative order of the middle ratio, and the relative order of the rear-side phase voltage difference, respectively, and identifies the relative order migration by the connection relationship of the same phase. Each column of the relative order in the three-phase phase migration diagram is stored as an ordered phase sequence of phases A, B, and C, and the rank of each phase in this ordered phase sequence is also stored; a rank of 1 indicates the largest measurement quantity at the top of the column, a rank of 2 indicates the second largest measurement quantity, and a rank of 3 indicates the smallest measurement quantity. Through the ordered phase sequence and rank, the diagnostic processor 500 can directly compare the upper and lower positions of the same phase in the relative order of the front-side phase voltage difference, the relative order of the middle ratio, and the relative order of the rear-side phase voltage difference.

[0036] In the formula, Indicates the measurement location number The three-phase phase migration diagram established at the corresponding intermediate measurement position 300. Measurement position number. Used to identify intermediate measurement position 300, with the preceding measurement position 300 being the measurement position sequence number. The corresponding measurement position 300, and the subsequent measurement position 300 is the measurement position number. The corresponding measurement position is 300.

[0037] In the formula, Indicates the previous measurement position 300, phase index. The corresponding phase voltage; Indicates intermediate measurement position 300, phase index The corresponding phase voltage; Indicates the next measurement position 300, phase index. The corresponding phase voltage, Indicates intermediate measurement position 300, phase index The active power of the corresponding phase. This indicates that the three phases A, B, and C are ordered relative to each other according to the corresponding measured quantities in parentheses from largest to smallest, and outputs the ordered phase sequence and the ranking of each phase in the ordered phase sequence. The left-hand items form the relative order of the front phase voltage difference, the middle items form the relative order of the middle ratio, and the right-hand items form the relative order of the rear phase voltage difference.

[0038] When the relative order of the current phase voltage difference, the relative order of the subsequent phase voltage difference, or the relative order of the intermediate ratio cannot be uniquely sorted due to equality, the diagnostic processor 500 does not determine the relative order migration based on this relative order.

[0039] When the physical measurement section to be assigned is located within an actual branch path, the three consecutive measurement positions 300 are selected within the same actual branch, and do not form a relative order of front-side phase voltage difference, a relative order of intermediate ratios, or a relative order of rear-side phase voltage difference across different actual branches. This setting ensures that the relative order of front-side and rear-side phase voltage difference reflects the spatial voltage difference relationship within the same actual branch, while the relative order of intermediate ratios reflects the phase load relationship at a common reference point within that actual branch. Since the power supply paths and load distributions differ between different actual branches, forming three relative orders across different actual branches would disrupt the relationship of the consecutive measurement positions 300 within the same actual branch.

[0040] Furthermore, based on the relative order of migration, the abnormal physical measurement sections and abnormal phases of line loss are determined, as follows: See Figure 1 After forming the three-phase phase migration diagram, the relative order migration diagnostic unit 530 detects whether the relative order migration of the same phase occurs only between the intermediate ratio relative order and the one-sided phase voltage difference relative order, and whether it is unique. Here, the one-sided phase voltage difference relative order includes the front phase voltage difference relative order and the rear phase voltage difference relative order. The diagnostic processor 500 uses the intermediate ratio relative order as a common comparison benchmark to compare the ranking of each of the three phases A, B, and C in the intermediate ratio relative order with its ranking in the front phase voltage difference relative order and the rear phase voltage difference relative order.

[0041] When the ranking of the same phase in the relative order of phase voltage difference in the later phase is lower than its ranking in the relative order of the intermediate ratio, and the ranking of the same phase in the relative order of phase voltage difference in the earlier phase is not lower than its ranking in the relative order of the intermediate ratio, the relative order migration diagnosis unit 530 determines that the relative order migration of the same phase only occurs between the relative order of the intermediate ratio and the relative order of phase voltage difference in the later phase. A lower ranking indicates that the same phase has shifted towards the direction with a larger phase voltage difference in the corresponding phase voltage difference relative order; the increase in ranking of other phases due to the transposition of the same connection is not considered as the relative order migration for determining abnormal phases. When there is only one three-phase phase that satisfies the above relationship, the relative order migration is unique, and the diagnosis processor 500 determines the physical measurement section 400 between the intermediate measurement position 300 and the next measurement position 300 as the physical measurement section with abnormal line loss, and determines the same phase as the abnormal phase.

[0042] When the ranking of the same phase in the relative order of the preceding phase voltage difference is lower than its ranking in the relative order of the intermediate ratio, and the ranking of the same phase in the relative order of the following phase voltage difference is not lower than its ranking in the relative order of the intermediate ratio, the relative order migration diagnosis unit 530 determines that the relative order migration of the same phase only occurs between the relative order of the intermediate ratio and the relative order of the preceding phase voltage difference. A lower ranking indicates that the same phase has shifted towards the direction with a larger phase voltage difference in the corresponding phase voltage difference relative order; the increase in ranking of other phases due to the transposition of the same connection is not considered as the relative order migration for determining abnormal phases. When there is only one three-phase phase that satisfies the above relationship, the relative order migration is unique, and the diagnosis processor 500 determines the physical measurement section 400 between the previous measurement position 300 and the intermediate measurement position 300 as the physical measurement section with abnormal line loss, and determines the same phase as the abnormal phase.

[0043] The relative order migration, occurring only on one side and uniquely, is the criterion used in this embodiment to further determine the physical measurement section to be assigned as an abnormal line loss physical measurement section and an abnormal phase. The section active power loss characterization is used to screen out the physical measurement sections 400 that need phase assignment. The three columns of relative order are used to identify the relative position changes of the same phase on both sides of a common reference. The unilateral and unique relative order migration is used to map this change to one side of the intermediate measurement position 300. Since this criterion only considers the same phase that shifts in the direction of larger phase voltage difference and occurs only on one side as an abnormal phase, the diagnostic processor 500 will not simultaneously identify other phases whose ranking changes due to the transposition of the same connecting lines as abnormal phases.

[0044] The diagnostic processor 500 outputs the abnormal physical measurement section and abnormal phase determined by the relative sequence migration diagnostic unit 530. This output can be represented as the position identifier of the physical measurement section 400 in the power supply connection sequence and the abnormal phase identifier among the three phases A, B, and C. The physical measurement section to be assigned is formed by the section's active power loss characterization meeting preset electrical criteria; when the section's active power loss characterization uses the section's line loss ratio, the output result can be correlated with the comparison result of the section's line loss ratio and the line loss ratio allowed by electrical technology. Regardless of whether the section's active power loss characterization uses the active power difference or the section's line loss ratio, the final determination object is always the abnormal physical measurement section and abnormal phase.

[0045] The following describes this implementation method using the diagnostic process within the same sampling round.

[0046] In the same sampling round, the phase voltages of phase A, phase B, and phase C obtained from the previous measurement position 300 were 235V, 232V, and 232V, respectively, with active power of 10.2kW for phase A, 9.5kW for phase B, and 9.3kW for phase C. At the intermediate measurement position 300, the phase voltages of phase A, phase B, and phase C were 230V, 229V, and 228V, respectively, with active power of 8.7kW for phase A, 8.0kW for phase B, and 9.5kW for phase C. At the subsequent measurement position 300, the phase voltages of phase A, phase B, and phase C were 227V, 227V, and 224V, respectively, with active power of 8.2kW for phase A, 7.6kW for phase B, and 8.4kW for phase C.

[0047] The diagnostic processor 500 first establishes the correspondence between the power supply connection sequence, measurement positions 300, physical measurement sections 400, and three-phase phases using the correspondence establishment unit 510. The preceding measurement position 300, intermediate measurement position 300, and subsequent measurement position 300 are arranged consecutively according to the power supply direction. The power supply side measurement position 300 of the preceding physical measurement section 400 is the preceding measurement position 300, and the load side measurement position 300 is the intermediate measurement position 300; similarly, the power supply side measurement position 300 of the subsequent physical measurement section 400 is the intermediate measurement position 300, and the load side measurement position 300 is the subsequent measurement position 300. The three-phase phases A, B, and C maintain a consistent correspondence across the three measurement positions 300.

[0048] Subsequently, the active power loss characterization and determination unit 520 generates the section input active power and section output active power for the preceding physical measurement section 400. The section input active power of the preceding physical measurement section 400 is formed by the sum of the active power of the three phases A, B, and C at the previous measurement position 300, which is 29.0 kW; the section output active power of the preceding physical measurement section 400 is formed by the sum of the active power of the three phases A, B, and C at the intermediate measurement position 300, which is 26.2 kW. The section active power loss characterization is formed by the degree of equivalent difference between the two, and can be normalized to obtain a section line loss ratio of approximately 0.0966 for the preceding physical measurement section 400.

[0049] The active power loss characterization and determination unit 520 then generates the section input active power and section output active power for the subsequent physical measurement section 400. The section input active power of the subsequent physical measurement section 400 is formed by the sum of the active power of phases A, B, and C at the intermediate measurement position 300, which is 26.2kW; the section output active power of the subsequent physical measurement section 400 is formed by the sum of the active power of phases A, B, and C at the next measurement position 300, which is 24.2kW. The active power loss characterization is formed by the degree of equivalent difference between the two, and can be normalized to obtain a section line loss ratio of approximately 0.0763 for the subsequent physical measurement section 400.

[0050] If the allowable line loss ratio for electrical technology is 0.0500, then both the front physical measurement section 400 and the rear physical measurement section 400 meet the condition that the section line loss ratio exceeds the allowable line loss ratio for electrical technology. Both are considered candidate physical measurement sections for line loss and are entered into the relative order migration diagnostic unit 530 as physical measurement sections to be assigned. Since the two physical measurement sections to be assigned are adjacent, the diagnostic processor 500 selects the previous measurement position 300, the middle measurement position 300, and the next measurement position 300 as three consecutive measurement positions 300, with the middle measurement position 300 as a common reference.

[0051] The relative sequence migration diagnostic unit 530 generates the relative sequence of the front-side phase voltage differences. The phase voltage difference of phase A at the previous measurement position 300 relative to the middle measurement position 300 is 5V; the phase voltage difference of phase B at the previous measurement position 300 relative to the middle measurement position 300 is 3V; and the phase voltage difference of phase C at the previous measurement position 300 relative to the middle measurement position 300 is 4V. Therefore, the relative sequence of the front-side phase voltage differences is phase A, phase C, and phase B. This relative sequence corresponds to the magnitude relationship of the phase voltage differences in the three phases A, B, and C of the front-side physical measurement section 400.

[0052] The relative order migration diagnostic unit 530 forms an intermediate ratio relative order. At the intermediate measurement position 300, the ratio of active power to phase voltage for phase A is approximately 0.0378, for phase B it is approximately 0.0349, and for phase C it is approximately 0.0417. Therefore, the intermediate ratio relative order is phase C, phase A, and phase B. This relative order corresponds to the magnitude of the ratios of active power to phase voltage for phases A, B, and C at the intermediate measurement position 300.

[0053] The relative sequence migration diagnostic unit 530 generates the relative sequence of the subsequent phase voltage differences. The phase voltage difference of phase A at the intermediate measurement position 300 relative to the subsequent measurement position 300 is 3V; the phase voltage difference of phase B at the intermediate measurement position 300 relative to the subsequent measurement position 300 is 2V; and the phase voltage difference of phase C at the intermediate measurement position 300 relative to the subsequent measurement position 300 is 4V. Therefore, the relative sequence of the subsequent phase voltage differences is phase C, phase A, phase B. This relative sequence is consistent with the relative sequence of the intermediate ratio, indicating that no relative sequence migration has occurred between the relative sequence of the intermediate ratio and the relative sequence of the subsequent phase voltage differences for phase C.

[0054] After maintaining the consistency of phase identity, the relative order migration diagnosis unit 530 checks the ranking of the same phase in the three relative orders. Phase A is second in the middle ratio relative order, first in the front phase voltage difference relative order, and second in the rear phase voltage difference relative order; Phase A only shifts towards the direction of larger phase voltage difference relative to the middle ratio relative order in the front phase voltage difference relative order. Phase C is first in the middle ratio relative order, second in the front phase voltage difference relative order, and first in the rear phase voltage difference relative order; Phase C does not shift towards the direction of larger phase voltage difference. Phase B is third in all three relative orders. Therefore, only phase A satisfies the unilateral and unique relative order migration criterion, and this relative order migration only occurs between the middle ratio relative order and the front phase voltage difference relative order. Based on this, the diagnostic processor 500 identifies the physical measurement section 400 between the previous measurement position 300 and the intermediate measurement position 300 as the abnormal physical measurement section of line loss, and identifies phase A as the abnormal phase.

[0055] When the physical measurement section to be assigned is located on an actual branch path, the three consecutive measurement positions 300 in the numerical embodiment are selected according to the power supply connection sequence within the same actual branch. The section input active power and section output active power are still determined in the branch scenario according to the power supply side measurement position 300 and the load side measurement position 300 of the physical measurement section 400; when the load side measurement position 300 connects multiple actual branches, the section output active power is formed by the sum of the active power of the three phases A, B, and C on the load side of each actual branch. The relative order migration diagnostic unit 530 only forms the relative order of the front phase voltage difference, the relative order of the intermediate ratio, and the relative order of the rear phase voltage difference within the same actual branch, thereby maintaining the physical assignment relationship between the abnormal line loss physical measurement section and the abnormal phase.

[0056] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A smart diagnostic and analysis system for transformer substation line loss based on electrical sensors, comprising electrical sensors and a diagnostic processor, characterized in that, The electrical sensor measures the corresponding feeder location in the transformer substation and obtains the three-phase voltages (A, B, and C) and the three-phase active power (A, B, and C) during the same measurement period. The diagnostic processor establishes the correspondence between the power supply connection sequence, measurement location, physical measurement section and three-phase phase. It forms the active power loss characterization of the section by the equivalent difference between the active power input and the active power output of the section, and determines the physical measurement section that meets the preset electrical criteria as the physical measurement section to be assigned. For two physical measurement segments that include the physical measurement segment to be assigned and are connected end to end, select three consecutive measurement positions. With the middle measurement position as a common reference, form the relative order of the phase voltage difference of the previous measurement position relative to the middle measurement position, form the relative order of the phase ratio of the phase active power to the phase voltage of the middle measurement position, form the relative order of the phase voltage difference of the middle measurement position relative to the next measurement position, and maintain the phase identity consistent correspondence. When the relative order migration of the same phase occurs only between the relative order of the intermediate ratio and the relative order of the phase voltage difference on one side and is unique, the physical measurement section corresponding to that side is identified as the physical measurement section with abnormal line loss, and the phase is identified as the abnormal phase.

2. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, The diagnostic processor defines a physical measurement segment as the line between two adjacent measurement locations that does not contain other measurement locations in between. When the power supply path branches at a measurement location, it determines the subsequent physical measurement segments according to the physical connection sequence of each actual branch.

3. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, The electrical sensor obtains phase voltage and phase active power in the same sampling round. When the diagnostic processor is missing the phase voltage or phase active power of any phase at any measurement location in the same sampling round, it does not use the data from that sampling round to determine the abnormal physical measurement section and abnormal phase of the line loss.

4. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, The active power input of the section is the sum of the active power of the three phases A, B, and C at the measurement position on the power supply side of the physical measurement section, and the active power output of the section is the sum of the active power of the three phases A, B, and C at the measurement position on the load side of the physical measurement section.

5. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 4, characterized in that, When multiple actual branches are connected to the load-side measurement location of the physical measurement section, the diagnostic processor determines the sum of the three-phase active power of A, B, and C on the load side of each actual branch, and sums the three-phase active power of each actual branch as the output active power of the section.

6. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, The diagnostic processor normalizes the active power loss characterization of a section into a section line loss ratio. When the section line loss ratio exceeds the allowable line loss ratio of electrical technology, the corresponding physical measurement section is determined as a candidate physical measurement section for line loss. The candidate physical measurement section for line loss is used as a physical measurement section to be assigned.

7. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, The diagnostic processor establishes a three-phase phase migration diagram, which uses three columns of positional relationships to represent the relative order of the front phase voltage difference, the relative order of the middle ratio, and the relative order of the rear phase voltage difference, and identifies the relative order migration by the connection relationship of the same phase.

8. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 7, characterized in that, The relative order of the front phase voltage difference and the relative order of the rear phase voltage difference are formed by sorting the phase voltage difference from largest to smallest, and the relative order of the intermediate ratios is formed by sorting the ratio of phase active power to phase voltage from largest to smallest. When any relative order cannot be uniquely sorted due to equality, the diagnostic processor does not determine the relative order migration based on that relative order.

9. The intelligent diagnostic and analysis system for transformer substation line loss based on electrical sensors according to claim 1, characterized in that, When the physical measurement section to be assigned is located on the actual branch path, the three continuous measurement positions are selected within the same actual branch, and do not form a relative order of front phase voltage difference, relative order of middle ratio, and relative order of rear phase voltage difference across different actual branches.

Images