Method for detecting displacement of high-voltage switch in transformer substation

Abstract

The invention particularly relates to a method for detecting displacement of a high-voltage switch in a transformer substation, and belongs to the technical field of transformer substation equipment detection. When the electric field intensity is collected, the center voltage and the edge voltage are subjected to differential conditioning to obtain the center field intensity and the edge field intensity, interference in a transformer substation is eliminated and interference of the transformer substation is conditioned by subtracting the center field intensity from the edge field intensity, the collected field intensity is more accurate, and displacement of a high-voltage switch can be better facilitated; according to the invention, the field intensity array is formed by the field intensity of the current transformer and the A, B and C phases of the high-voltage switch, whether the high-voltage switch is displaced is detected through the change of the field intensity array, the switching-on and switching-off of the high-voltage switch can be reliably judged, the characteristics of the high-voltage switch during switching-on and switching-off can be judged and verified, and a judgment basis is provided for the switching-on and switching-off quality of the high-voltage switch.

Description

Technical Field

[0001] The 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 promotion of the application of one-button sequential control technology, the use of heterogeneous sensors to determine the opening and closing positions of high-voltage switches has attracted more and more attention. The opening and closing of high-voltage switches is accompanied by a sudden change in the electric field strength. At this time, if the sudden change in the electric field can be accurately collected, it is possible to detect whether the high-voltage switch has changed position. However, the electromagnetic environment in the substation is complex, and the interference signal is particularly significant at the moment of the opening and closing of the high-voltage switch. If the interference at the moment of the opening and closing of the high-voltage switch cannot be overcome, it is impossible to accurately measure the electric field near the high-voltage switch to accurately detect whether the high-voltage switch has changed position. If it is impossible to accurately detect whether the high-voltage switch has changed position, there is no way to talk about one-button sequential control technology. Therefore, how to accurately detect whether the high-voltage switch in the substation has changed position 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 of the high-voltage switch at the moment of opening and closing, and accurately detect the displacement of the high-voltage switch.

[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is: a method for detecting the 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; setting a position change detection period T of 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 it into the following formula (1) to perform differential conditioning and calculate the central field strength of the first A-phase electric field sensor: ,

[0007] (1)

[0008] In formula (1), is the dielectric constant of air; is the effective area of ​​the plane plate of the first A-phase electric field sensor; is the sampling capacitor value; is the plate thickness of the first A-phase electric field sensor; is a multiple of differential conditioning; is the structural correction coefficient of the first A-phase electric field sensor; The central voltage of the first A phase electric field sensor is collected Common mode interference voltage received; is the offset voltage during differential conditioning; is the fringe field strength of the first A-phase 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 it into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first A-phase electric field sensor: ,

[0010] (2);

[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 A-phase electric field strength of the current transformer in the displacement detection period T: ,

[0012] (3);

[0013] Step 3: Calculate the time before the high-voltage switch changes position within the position detection period T according to step 2. The A phase electric field strength is , 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 Calculate the time after the high-voltage switch is displaced within the displacement detection period T according to step 2 The A phase electric field strength is , 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 ;

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

[0015] (4),

[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 to perform the following steps;

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

[0020] (5),

[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 to perform the following steps;

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

[0024] (6),

[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 means that the high-voltage switch is 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 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 from the edge field strength, so that the collected field strength is more accurate and 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, which 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 basis for judging the quality of the opening and closing 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 the position change of a high-voltage switch in a substation in this embodiment includes the following steps:

[0031] Step 1: respectively set 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 set 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 in the substation; set the displacement detection period T of 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 ; Set the center voltage of the first A phase electric field sensor Substitute it into the following formula (1) to perform differential conditioning and calculate the central field strength of the first A phase electric field sensor: ,

[0033] (1)

[0034] In formula (1), is the dielectric constant of air; is the effective area of ​​the plane plate of the first A-phase electric field sensor; is the sampling capacitor value; is the plate thickness of the first A-phase electric field sensor; is a multiple of differential conditioning; is the structural correction coefficient of the first A-phase electric field sensor; It is used to collect the center voltage of the first A phase electric field sensor Common mode interference voltage received; is the offset voltage during differential conditioning; is the fringe field strength of the first A-phase 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 it into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first phase A electric field sensor: ,

[0036] (2);

[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 in the displacement detection period T: ,

[0038] (3);

[0039] Step 3: Calculate the time before the high-voltage switch changes position within the position detection period T according to step 2 The A phase electric field strength is , B electric field strength and C phase electric field strength and the electric field strength of phase A of the current transformer , B phase electric field strength and C phase electric field strength ; According to step 2, the time when the high-voltage switch is shifted within the shift detection period T is calculated The A phase electric field strength is , B electric field strength and C phase electric field strength and the electric field strength of phase A of the current transformer , B phase electric field strength and C phase electric field strength ;

[0040] Step 4: Take the data obtained in step 3 and , , and Substitute into the following formula (4) to detect the displacement of the high-voltage switch:

[0041] (4),

[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 change detection period T;

[0044] If formula (4) is satisfied, continue to perform the following steps;

[0045] Step 5: Take the data obtained in step 3 and , , and Substitute into the following formula (5) to detect the displacement of the high-voltage switch:

[0046] (5),

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

[0048] If formula (5) is satisfied, continue to perform the following steps;

[0049] Step 6: Take the data obtained in step 3 and , , and Substitute into the following formula (6) to detect the displacement of the high-voltage switch:

[0050] (6),

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

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

Claims

1. A method for detecting position change of a high voltage switch in a substation, characterized in that: 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 the A, B and C phases 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 arranged 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 it into the following formula (1) to perform differential conditioning and calculate the central field strength of the first A-phase electric field sensor: , （1） In formula (1), is the dielectric constant of air; is the effective area of ​​the plane plate of the first A-phase electric field sensor; is the sampling capacitor value; is the plate thickness of the first A-phase electric field sensor; is a multiple of differential conditioning; is the structural correction coefficient of the first A-phase electric field sensor; The central voltage of the first A phase electric field sensor is collected Common mode interference voltage received; is the offset voltage during differential conditioning; is the fringe field strength of the first A-phase 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 it into the following formula (2) to perform differential conditioning and calculate the edge field strength of the first A-phase electric field sensor: , （2）； 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 A-phase electric field strength of the current transformer in the displacement detection period T: , （3）； Step 3: Calculate the time before the high-voltage switch changes position within the position detection period T according to step 2. The A phase electric field strength is , 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 Calculate the time after the high-voltage switch is displaced within the displacement detection period T according to step 2 The A phase electric field strength is , 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 ; Step 4: The , , and Substitute into the following formula (4) to detect the displacement of the high-voltage switch: （4）， 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 to perform the following steps; Step 5: The , , and Substitute into the following formula (5) to detect the displacement of the high-voltage switch: （5）， 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 to perform the following steps; Step 6: The , , and Substitute into the following formula (6) to detect the displacement of the high-voltage switch: （6）， 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 means that the high-voltage switch is displaced within the displacement detection period T.

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