Method for detecting position change of high voltage switch in substation

Abstract

The present invention specifically relates to a method for detecting the position change of a high-voltage switch in a substation, and belongs to the technical field of substation equipment detection. When collecting electric field strength, the present invention obtains the central field strength and the edge field strength through differential conditioning of the central voltage and the edge voltage, and eliminates the interference in the substation and the interference of the conditioning itself by subtracting the central field strength and the edge field strength, so that the collected field strength is more accurate, which can be more beneficial to the position change of the high-voltage switch; the present invention uses the field strength of the current transformer and the A, B and C phases of the high-voltage switch to form a field strength array, and detects whether the high-voltage switch has changed position through the change of the field strength array. It can not only reliably judge the opening and closing of the high-voltage switch, but also judge and verify the characteristics of the high-voltage switch when opening and closing, and provide a judgment basis for the opening and closing quality of the high-voltage switch.

Description

Technical Field

[0001] The present invention specifically relates to a method for detecting position change of a high-voltage switch in a transformer substation, and belongs to the technical field of transformer substation equipment detection. Background Art

[0002] In recent years, with the widespread application of one-touch sequential control technology, the use of heterogeneous sensors to determine the open and close positions of high-voltage switches has attracted increasing attention. The opening and closing of a high-voltage switch is accompanied by a sudden change in electric field strength. Accurately capturing this sudden change in electric field can detect switch position changes. However, the electromagnetic environment within a substation is complex, and interference signals are particularly significant at the moment the high-voltage switch opens and closes. Without overcoming this interference, it is impossible to accurately measure the electric field near the high-voltage switch to accurately detect switch position changes. Without accurate detection of high-voltage switch position changes, one-touch sequential control technology is impossible. Therefore, accurately detecting high-voltage switch position changes within a substation has become a key technology for realizing smart substations. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: how to avoid the interference at the moment of opening and closing of the high-voltage switch and accurately detect the displacement of the high-voltage switch.

[0004] To solve the above technical problems, the present invention proposes a technical solution: a method for detecting position change of a high-voltage switch in a substation, comprising the following steps:

[0005] Step 1: respectively setting a first A-phase electric field sensor, a first B-phase electric field sensor, and a first C-phase electric field sensor on the A, B, and C phases of the current transformer in the substation; respectively setting a second A-phase electric field sensor, a second B-phase electric field sensor, and a second C-phase electric field sensor on the A, B, and C phases of the high-voltage switch to be detected for position change in the substation; and setting a position change detection period T for the high-voltage switch;

[0006] Step 2: Within a displacement detection period T, collect the center voltage of the first A-phase electric field sensor The center voltage of the first A-phase electric field sensor Substitute into the following formula (1) to perform differential conditioning and calculate the central field strength of the first A-phase electric field sensor:

[0007]

[0008] In formula (1), ε0 is the dielectric constant of air; S is the effective area of the plane plate of the first A-phase electric field sensor; C sis the sampling capacitance value; d is the plate thickness of the first A-phase electric field sensor; k1 is the multiple of differential conditioning; a is the structural correction coefficient of the first A-phase electric field sensor; V cm The central voltage of the first phase A electric field sensor is collected Common mode interference voltage received; V os is the offset voltage during differential conditioning; is the fringe field strength of the first phase A electric field sensor;

[0009] Collect the edge voltage of the first A phase electric field sensor The edge voltage of the first A-phase electric field sensor Substitute into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first A phase electric field sensor:

[0010]

[0011] The center field strength of the first A-phase electric field sensor The fringe field strength of the first A-phase electric field sensor Substituting into the following formula (3), we can get the electric field strength of phase A of the current transformer during the displacement detection period T:

[0012]

[0013] Step 3: Calculate the A-phase electric field strength of the high-voltage switch at time t0 before the high-voltage switch is displaced within the displacement detection period T according to step 2. B. Electric field strength and C phase electric field strength and the A-phase electric field strength of the current transformer B phase electric field strength and C phase electric field strength According to step 2, the A-phase electric field strength of the high-voltage switch at time t after the high-voltage switch is displaced within the displacement detection period T is calculated. B. Electric field strength and C phase electric field strength and the A-phase electric field strength of the current transformer Phase B electric field strength and C phase electric field strength

[0014] Step 4: Take the and Substitute into the following formula (4) to detect the displacement of the high-voltage switch:

[0015]

[0016] In formula (4), T1 and T2 are the first detection threshold and the second detection threshold, respectively, both of which are empirical values;

[0017] If formula (4) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T;

[0018] If formula (4) is satisfied, continue with the following steps:

[0019] Step 5: Take the and Substitute into the following formula (5) to detect the displacement of the high-voltage switch:

[0020]

[0021] If formula (5) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T;

[0022] If formula (5) is satisfied, continue with the following steps:

[0023] Step 6: Take the and Substitute into the following formula (6) to detect the displacement of the high-voltage switch:

[0024]

[0025] If formula (6) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T;

[0026] If formula (6) is satisfied, it indicates that the high-voltage switch has been displaced within the displacement detection period T.

[0027] The beneficial effects of the present invention are as follows: 1. When collecting electric field strength, the present invention obtains central field strength and edge field strength through differential conditioning of central voltage and edge voltage, and eliminates interference in the substation and interference of the conditioning itself by subtracting the central field strength from the edge field strength, so that the collected field strength is more accurate, which can be more beneficial to the displacement of the high-voltage switch; 2. The present invention adopts the field strength of the current transformer and the A, B and C phases of the high-voltage switch to form a field strength array, and detects whether the high-voltage switch has been displaced by the change of the field strength array. It can not only reliably judge the opening and closing of the high-voltage switch, but also judge and verify the characteristics of the high-voltage switch when opening and closing, and provide a judgment basis for the opening and closing quality of the high-voltage switch. DETAILED DESCRIPTION

[0028] The following is a further description of a method for detecting position change of a high-voltage switch in a substation according to the present invention in conjunction with a specific embodiment.

[0029] Example

[0030] The method for detecting position change of a high-voltage switch in a substation in this embodiment includes the following steps:

[0031] Step 1: Install a first A-phase electric field sensor, a first B-phase electric field sensor, and a first C-phase electric field sensor on phases A, B, and C of a current transformer in a substation, respectively; install a second A-phase electric field sensor, a second B-phase electric field sensor, and a second C-phase electric field sensor on phases A, B, and C of a high-voltage switch to be detected for position change in the substation, respectively; and set a position change detection period T for the high-voltage switch;

[0032] Step 2: Within a displacement detection period T, collect the center voltage of the first A-phase electric field sensor The center voltage of the first A-phase electric field sensor Substitute into the following formula (1) to perform differential conditioning and calculate the central field strength of the first phase A electric field sensor:

[0033]

[0034] In formula (1), ε0 is the dielectric constant of air; S is the effective area of the plane plate of the first A-phase electric field sensor; C s is the sampling capacitance value; d is the plate thickness of the first A-phase electric field sensor; k1 is the multiple of differential conditioning; a is the structural correction coefficient of the first A-phase electric field sensor; V cm It is used to collect the center voltage of the first phase A electric field sensor Common mode interference voltage received; V os is the offset voltage during differential conditioning; is the fringe field strength of the first phase A electric field sensor;

[0035] Collect the edge voltage of the first phase A electric field sensor The edge voltage of the first A phase electric field sensor Substitute into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first phase A electric field sensor:

[0036]

[0037] The center field strength of the first A phase electric field sensor The fringe field strength of the first A-phase electric field sensor Substituting into the following formula (3), we can get the electric field strength of phase A of the current transformer during the position change detection period T:

[0038]

[0039] Step 3: Calculate the A-phase electric field strength of the high-voltage switch at time t0 before the high-voltage switch changes position within the position detection period T according to step 2. B. Electric field strength and C phase electric field strength and the electric field strength of phase A of the current transformer Phase B electric field strength and C phase electric field strength According to step 2, the A-phase electric field strength of the high-voltage switch at time t after the high-voltage switch is displaced within the displacement detection period T is calculated. B. Electric field strength and C phase electric field strength and the electric field strength of phase A of the current transformer Phase B electric field strength and C phase electric field strength

[0040] Step 4: Take the and Substitute into the following formula (4) to detect the displacement of the high-voltage switch:

[0041]

[0042] In formula (4), T1 and T2 are the first detection threshold and the second detection threshold, respectively, both of which are empirical values;

[0043] If formula (4) is not satisfied, it means that the high-voltage switch does not change position within the position detection period T;

[0044] If formula (4) is satisfied, continue with the following steps:

[0045] Step 5: Take the and Substitute into the following formula (5) to detect the displacement of the high-voltage switch:

[0046]

[0047] If formula (5) is not satisfied, it means that the high-voltage switch does not change position within the position detection period T;

[0048] If formula (5) is satisfied, continue with the following steps:

[0049] Step 6: Take the and Substitute into the following formula (6) to detect the displacement of the high-voltage switch:

[0050]

[0051] If formula (6) is not satisfied, it means that the high-voltage switch does not change position within the position detection period T;

[0052] If formula (6) is satisfied, it means that the high-voltage switch has shifted within the shift detection period T.

Claims

1. A method for detecting position change of a high-voltage switch in a substation, characterized by: The following steps are involved: Step 1: respectively setting a first A-phase electric field sensor, a first B-phase electric field sensor, and a first C-phase electric field sensor on phases A, B, and C of the current transformer in the substation; A second A-phase electric field sensor, a second B-phase electric field sensor, and a second C-phase electric field sensor are respectively provided on the A, B, and C phases of the high-voltage switch to be subjected to position change detection in the substation; Setting a displacement detection period T of the high voltage switch; Step 2: Within a displacement detection period T, collect the center voltage of the first A-phase electric field sensor The center voltage of the first A-phase electric field sensor Substitute into the following formula (1) to perform differential conditioning and calculate the central field strength of the first phase A electric field sensor: In formula (1), ε0 is the dielectric constant of air; S is the effective area of the plane plate of the first A-phase electric field sensor; C s is the sampling capacitance value; d is the plate thickness of the first A-phase electric field sensor; k1 is the multiple of differential conditioning; a is the structural correction coefficient of the first A-phase electric field sensor; V cm The central voltage of the first phase A electric field sensor is collected Common mode interference voltage received; V os is the offset voltage during differential conditioning; is the fringe field strength of the first phase A electric field sensor; Collect the edge voltage of the first A phase electric field sensor The edge voltage of the first A-phase electric field sensor Substitute into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first A phase electric field sensor: The center field strength of the first A-phase electric field sensor The fringe field strength of the first A-phase electric field sensor Substituting into the following formula (3), we can get the electric field strength of phase A of the current transformer during the displacement detection period T: Step 3: Calculate the A-phase electric field strength of the high-voltage switch at time t0 before the high-voltage switch is displaced within the displacement detection period T according to step 2. Phase B electric field strength and C phase electric field strength and the A-phase electric field strength of the current transformer Phase B electric field strength and C phase electric field strength According to step 2, the A-phase electric field strength of the high-voltage switch at time t after the high-voltage switch is displaced within the displacement detection period T is calculated. Phase B electric field strength and C phase electric field strength and the A-phase electric field strength of the current transformer Phase B electric field strength and C phase electric field strength Step 4: Take the and Substitute into the following formula (4) to detect the displacement of the high-voltage switch: In formula (4), T1 and T2 are the first detection threshold and the second detection threshold, respectively, both of which are empirical values; If formula (4) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T; If formula (4) is satisfied, continue with the following steps: Step 5: Take the and Substitute into the following formula (5) to detect the displacement of the high-voltage switch: If formula (5) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T; If formula (5) is satisfied, continue with the following steps: Step 6: Take the and Substitute into the following formula (6) to detect the displacement of the high-voltage switch: If formula (6) is not satisfied, it means that the high-voltage switch does not change position within the change detection period T; If formula (6) is satisfied, it indicates that the high-voltage switch has been displaced within the displacement detection period T.

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