Method for locating short-circuit fault position point of high-voltage equipment

Abstract

The application discloses a method for checking a short-circuit fault position point of a high-voltage device, which comprises the following steps: S1, establishing a substation feeder switch cabinet circuit breaker protection tripping historical fault information account; S2, establishing a substation feeder switch cabinet circuit breaker protection setting information account; S3, acquiring protection tripping fault information of a microcomputer protection device of a substation feeder switch cabinet circuit breaker; S4, converting a secondary action current value of the microcomputer protection device into a primary short-circuit current value, comparing and analyzing the primary short-circuit current value with a primary short-circuit current value of a line historical fault information account, and combining the protection setting information account to preliminarily analyze and determine the position of a short-circuit fault point; and S5, acquiring user-side device tripping fault information to finally determine the position of the short-circuit fault point. The application can quickly determine whether a fault point is on a power line side or a user side, comprehensively analyze and determine the position of a short-circuit fault point, realize quick searching of the short-circuit fault point, and improve the fault searching efficiency.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage equipment fault diagnosis technology, and in particular relates to a method for diagnosing the location of short-circuit faults in high-voltage equipment. Background Technology

[0002] Substations are power facilities in a power system that transform voltage, receive and distribute electrical energy, control the flow of power, and regulate voltage. After voltage reduction by power transformers, the power is distributed through high-voltage switchgear and transmitted via power lines to the next-level substation (user-side substation), providing the necessary voltage levels to user equipment. In practice, due to various reasons such as complex power system wiring structures, some busbar systems having generator units connected to the grid, poor system operating environments, aging equipment, mismatched relay protection configurations, and insufficient maintenance, equipment and line faults frequently occur, endangering the safety and stability of user power supply. Therefore, after a short-circuit fault occurs in substation equipment lines, due to outdated fault location methods and untimely information exchange or concealment of fault information between power supply departments, energy users, and power dispatch centers during the fault location process, it is often impossible to promptly determine whether the fault is in user-side equipment or the substation's power supply lines. This often significantly prolongs the fault location time, resulting in substantial economic losses.

[0003] Therefore, how to quickly and accurately locate the fault point, eliminate the fault, and quickly restore the power supply has become an urgent problem to be solved. To this end, a method for locating the short circuit fault point of high-voltage equipment is provided. Summary of the Invention

[0004] To at least partially solve the technical problems existing in the prior art, the present invention provides a method for locating short-circuit faults in high-voltage equipment.

[0005] The method for locating short-circuit faults in high-voltage equipment according to the present invention includes: S1: Establish a historical fault information ledger for circuit breaker protection tripping of each feeder switchgear in the substation. Establish a separate fault information ledger for each line and update the relevant information in real time after the line short-circuit fault is handled. S2: Establish a ledger of protection setting information for circuit breakers in each feeder switchgear of the substation. S3: Obtain protection tripping fault information of the microcomputer protection device of the circuit breaker in the substation feeder switchgear; S4: Convert the secondary operating current value of the microprocessor protection device to the primary short-circuit current value, compare and analyze it with the primary short-circuit current value in the line historical fault information ledger, and combine it with the protection setting information ledger to preliminarily analyze and determine the location of the short-circuit fault point. S5: Obtain tripping fault information from user-side equipment and ultimately determine the location of the short-circuit fault.

[0006] Furthermore, in the above-mentioned method for investigating the location of short-circuit faults in high-voltage equipment, in step S1, the contents of the line historical fault information ledger include: equipment line name, fault nature, fault type, secondary current value of fault action, current transformer current ratio, fault cause, fault location, status of grid-connected generator units of the bus system when the fault occurred, and the first, second, third, and fourth historical primary short-circuit current values.

[0007] Furthermore, in the above-mentioned method for tracing the location of short-circuit faults in high-voltage equipment, in step S3, the protection trip fault information of the microprocessor protection device includes: fault action type, secondary action current value, current ratio, voltage and other protection action fault information.

[0008] Furthermore, in the above-mentioned method for locating short-circuit faults in high-voltage equipment, the short-circuit fault location analysis and determination process in step S4 is as follows: Check whether there are any generator units connected to the grid on the bus system where the feeder switchgear is located before the tripping fault occurred. If so, when the primary short-circuit current value is close to the historical first primary short-circuit current value, the short-circuit fault location is preliminarily determined to be on the power line supplied by the feeder switchgear; when the primary short-circuit current value is close to the historical second primary short-circuit current value, the short-circuit fault location is preliminarily determined to be on the equipment or line of the user-side substation. If there are no grid-connected generator units, when the primary short-circuit current value is close to the historical third primary short-circuit current value, the short-circuit fault location is preliminarily determined to be on the power line supplied by the feeder switchgear; when the primary short-circuit current value is close to the historical fourth primary short-circuit current value, the short-circuit fault location is preliminarily determined to be on the equipment or line of the user-side substation.

[0009] Furthermore, in the above-mentioned method for locating short-circuit faults in high-voltage equipment, the process for determining the location of the short-circuit fault in step S5 is as follows: Information on the protection tripping faults of the user-side incoming power switchgear, the high and low voltage backup fault tripping faults of the main transformer, and the protection tripping faults of the low-voltage side bus feeder cabinet of the main transformer are obtained respectively. If a short-circuit tripping fault also occurs in the user-side equipment, it is analyzed and confirmed to be a protection over-tripping fault caused by protection defects such as protection setting mismatch, thus ultimately determining the location of the equipment short-circuit fault.

[0010] The method for locating short-circuit faults in high-voltage equipment according to the present invention has the following advantages and beneficial effects: This invention analyzes and compares fault tripping information with historical fault information and protection settings to preliminarily determine whether the short-circuit fault point is on the power line side or the user side. Combined with the user-side equipment tripping fault information, the invention comprehensively analyzes and determines the location of the short-circuit fault point, thereby achieving rapid location of the short-circuit fault point and improving fault finding efficiency. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for further understanding of the embodiments of the present invention and constitute a part of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a flowchart of the method for locating short-circuit faults in high-voltage equipment according to the present invention. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0013] like Figure 1 As shown, the method for locating short-circuit faults in high-voltage equipment according to the present invention includes: S1: Establish a historical fault information ledger for circuit breaker protection tripping of each feeder switchgear in the substation. Establish a separate fault information ledger for each line and update the relevant information in real time after the line short-circuit fault is handled. S2: Establish a ledger of protection setting information for circuit breakers in each feeder switchgear of the substation. S3: Obtain protection tripping fault information of the microcomputer protection device of the circuit breaker in the substation feeder switchgear; S4: Convert the secondary operating current value of the microprocessor protection device to the primary short-circuit current value, compare and analyze it with the primary short-circuit current value in the line historical fault information ledger, and combine it with the protection setting information ledger to preliminarily analyze and determine the location of the short-circuit fault point. S5: Obtain tripping fault information from user-side equipment and ultimately determine the location of the short-circuit fault.

[0014] Furthermore, in the method for investigating the location of short-circuit faults in high-voltage equipment of the present invention, in step S1, the contents of the historical fault information ledger of the line include: equipment line name, fault nature, fault type, secondary current value of fault action, current transformer current ratio, fault cause, fault location, status of grid-connected generator units of the bus system when the fault occurred, and the first, second, third, and fourth historical primary short-circuit current values.

[0015] Furthermore, in the method for tracing the location of short-circuit faults in high-voltage equipment according to the present invention, in step S3, the protection tripping fault information of the microcomputer protection device includes: fault action type, secondary action current value, current ratio, voltage and other protection action fault information.

[0016] Furthermore, in the method for locating short-circuit faults in high-voltage equipment according to the present invention, in step S4, the process for analyzing and determining the location of the short-circuit fault is as follows: Check whether there is a generator unit connected to the grid in the bus system where the feeder switchgear is located before the tripping fault occurs. If so, when the primary short-circuit current value is close to the historical first primary short-circuit current value, the fault location is initially determined to be on the power line supplied by the feeder switchgear; when the primary short-circuit current value is close to the historical second primary short-circuit current value, the fault location is initially determined to be on the equipment or line of the user-side substation. If there is no grid-connected generator unit, when the primary short-circuit current value is close to the historical third primary short-circuit current value, the fault location is initially determined to be on the power line supplied by the feeder switchgear; when the primary short-circuit current value is close to the historical fourth primary short-circuit current value, the fault location is initially determined to be on the equipment or line of the user-side substation. Specifically, the first historical short-circuit current was 6500A, the second historical short-circuit current was 3500A, the third historical short-circuit current was 5000A, and the second historical short-circuit current was 2600A.

[0017] Furthermore, in the method for locating short-circuit faults in high-voltage equipment according to the present invention, in step S5, the process for determining the location of the short-circuit fault is as follows: Information on the protection tripping faults of the user-side incoming power switchgear, the high and low backup fault tripping information of the main transformer, and the protection tripping fault information of the main transformer's low-voltage side bus feeder cabinet are obtained respectively. If a short-circuit tripping fault also occurs in the user-side equipment, it is analyzed and confirmed to be a protection over-tripping fault caused by protection defects such as protection setting mismatch, and the location of the equipment short-circuit fault is finally determined. The substation is a 110kV / 35kV substation. After the main transformer transforms the voltage, it supplies power to the 35kV feeder switchgear of the substation. Then, it supplies power to the user-side equipment through power lines (mainly power cable lines, and partly cable lines and overhead lines). The user-side equipment includes the user-side 35kV incoming power switchgear, main transformer, 10kV busbar equipment and its feeder lines, load equipment, etc.

[0018] In summary, compared with the prior art, the method for locating short-circuit faults in high-voltage equipment of the present invention has the following advantages and beneficial effects: The present invention analyzes and compares fault tripping information with historical fault information and protection setting values ​​to preliminarily determine whether the short-circuit fault point is on the power line side or the user side, and combines the user-side equipment tripping fault information to comprehensively analyze and determine the location of the short-circuit fault point, thereby realizing rapid location of short-circuit fault points and improving fault location efficiency.

[0019] It should be noted that, unless otherwise expressly specified and limited, the term "connection" or its synonyms should be interpreted broadly in this document. For example, "connection" can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, expressions such as "first" and "second" are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Meanwhile, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In addition, the terms "front," "rear," "left," "right," "upper," and "lower" in this document refer to the placement states shown in the accompanying drawings.

[0020] 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; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for locating short-circuit faults in high-voltage equipment, characterized in that, The method for locating short-circuit faults in high-voltage equipment includes: S1: Establish a historical fault information ledger for circuit breaker protection tripping of each feeder switchgear in the substation. Establish a separate fault information ledger for each line and update the relevant information in real time after the line short-circuit fault is handled. S2: Establish a ledger of protection setting information for circuit breakers in each feeder switchgear of the substation. S3: Obtain protection tripping fault information of the microcomputer protection device of the circuit breaker in the substation feeder switchgear; S4: Convert the secondary operating current value of the microprocessor protection device to the primary short-circuit current value, compare and analyze it with the primary short-circuit current value in the line's historical fault log, and combine it with the protection setting information log to preliminarily analyze and determine the location of the short-circuit fault point. The process for analyzing and determining the location of a short-circuit fault is as follows: First, check whether there are any generator units connected to the grid in the bus system where the feeder switchgear is located before the tripping fault occurs. If so, if the primary short-circuit current value is close to the historical first primary short-circuit current value, the short-circuit fault location is initially determined to be on the power line supplied by the feeder switchgear. If the primary short-circuit current value is close to the historical second primary short-circuit current value, the short-circuit fault location is initially determined to be on the equipment or line of the user-side substation. If there are no grid-connected generator units, if the primary short-circuit current value is close to the historical third primary short-circuit current value, the short-circuit fault location is initially determined to be on the power line supplied by the feeder switchgear. If the primary short-circuit current value is close to the historical fourth primary short-circuit current value, the fault location is initially determined to be on the equipment or line of the user-side substation. S5: Obtain tripping fault information of user-side equipment and finally determine the location of the short-circuit fault point; The process for determining the location of a short-circuit fault is as follows: obtain the protection tripping fault information of the incoming power switch cabinet on the user side, the high and low backup fault tripping information of the main transformer, and the protection tripping fault information of the low-voltage side bus feeder cabinet of the main transformer. If a short-circuit tripping fault also occurs on the user side equipment, it is analyzed and confirmed that the protection setting mismatch and protection defect are caused by the protection over-level tripping fault, and finally the location of the equipment short-circuit fault is determined.

2. The method for locating short-circuit faults in high-voltage equipment according to claim 1, characterized in that, In step S1, the information in the line history fault log includes: equipment line name, fault nature, fault type, secondary current value of fault action, current transformer current ratio, fault cause, fault location, status of grid-connected generator units of the bus system when the fault occurred, and the first, second, third, and fourth primary short-circuit current values ​​in history.

3. The method for locating short-circuit faults in high-voltage equipment according to claim 1, characterized in that, In step S3, the protection trip fault information of the microprocessor protection device includes: fault action type, secondary action current value, current ratio, and voltage protection action fault information.

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