Coupling capacitance method partial discharge sensor and distribution transformer

Abstract

The utility model discloses a coupling capacitance method partial discharge sensor and a distribution transformer. The coupling capacitance method partial discharge sensor comprises a radio frequency connector socket, an induction pole plate, a coupling pole plate, a voltage dividing pole plate and an insulating layer between the pole plates. The induction pole plate induces distorted space electromagnetic wave signals generated by partial discharge and generates induction charges, the induction pole plate and the coupling pole plate form a coupling capacitor, the coupling pole plate and the voltage dividing pole plate form a voltage dividing capacitor, insulating layers are arranged among the induction pole plate, the coupling pole plate and the voltage dividing pole plate, and the coupling pole plate is connected with a radio frequency connector core wire. The voltage dividing pole plate is connected with the radio frequency connector metal shell and is input to an oscilloscope or a partial discharge measuring device, and the purpose of measuring partial discharge signals is achieved.

Description

Technical Field

[0001] This utility model relates to the field of partial discharge signal detection inside 6kV~35kV medium-voltage equipment such as distribution transformers, and specifically relates to a coupling capacitor method partial discharge sensor and a distribution transformer. Background Technology

[0002] Due to the height of medium-voltage equipment or the inconvenience of installing it externally, conventional capacitive coupling methods cannot directly contact the outer surface of high-voltage equipment for partial discharge detection. This invention, however, senses the electromagnetic wave signal generated in space when partial discharge occurs in medium-voltage equipment on an induction plate, and then uses the coupling capacitor method to detect partial discharge phenomena in medium-voltage equipment such as distribution transformers and pole-mounted switches, achieving the purpose of non-contact detection and evaluation of the insulation status of medium-voltage equipment. Utility Model Content

[0003] Purpose of the utility model: This utility model proposes a partial discharge sensor and distribution transformer based on the coupling capacitance method, which is used to detect partial discharge phenomena in medium-voltage equipment and evaluate the insulation status of medium-voltage equipment by means of the coupling capacitance method.

[0004] Technical solution: The present invention proposes a partial discharge sensor using a coupling capacitor method, comprising a sensing electrode, a coupling electrode, a voltage dividing electrode, and an insulating layer; the sensing electrode and the coupling electrode form a coupling capacitor, the coupling electrode and the voltage dividing electrode form a voltage dividing capacitor, an insulating layer is provided between the sensing electrode and the coupling electrode, and an insulating layer is provided between the coupling electrode and the voltage dividing electrode.

[0005] Preferably, the induction plate, coupling plate, and voltage dividing plate are fabricated using the same printed circuit board.

[0006] Preferably, the insulating layer material is FR4, and the induction electrode plate, coupling electrode plate, and voltage dividing electrode plate are copper foil.

[0007] Preferably, the coupling plate is connected to the RF connector core wire, and the voltage divider plate is connected to the RF connector housing.

[0008] Preferably, the partial discharge sensor has a detection frequency band in the range of 1MHz to 100MHz, and a bandwidth greater than 10MHz.

[0009] Beneficial effects: (1) By replacing the outer metal surface of high-voltage equipment with induction plates, the purpose of non-contact detection of partial discharge can be achieved. Partial discharge generated by equipment such as distribution transformers, pole-mounted switches, distribution line insulators, and pole-to-ground cable terminal joints can be detected within a safe distance.

[0010] (2) A voltage divider capacitor is formed by a voltage divider plate and a coupling plate to replace the voltage divider capacitor in the partial discharge detection instrument. The voltage divider plate is connected to the RF connector housing and connected to the ground terminal of the detection instrument to achieve the suppression of electromagnetic interference in the non-inductive direction.

[0011] (3) This utility model can also be used for partial discharge monitoring inside or near power distribution transformers. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the sensor structure of this utility model;

[0013] Figure 2 This is a top view of the sensor of this utility model;

[0014] Figure 3 This is a schematic diagram of the sensor of this utility model; Detailed Implementation

[0015] The following description, in conjunction with the accompanying drawings, provides further examples of the present invention used for partial discharge monitoring of distribution transformers.

[0016] A type of partial discharge sensor using coupling capacitance, such as Figure 1 As shown, the sensor consists of an RF connector socket, a sensing plate 1, a coupling plate 2, a voltage dividing plate 3, and an insulating layer 4 between the plates. The sensing plate 1 senses the distorted spatial electromagnetic wave signal generated by partial discharge and generates an induced charge, forming a coupling capacitor with the coupling plate 2. The coupling plate 2 and the voltage dividing plate 3 form a voltage dividing capacitor. The insulating layer 4 connects the sensing plate 1, the coupling plate 2, and the voltage dividing plate 3. The coupling plate 2 is connected to the RF connector core wire 5, and the voltage dividing plate 3 is connected to the RF connector metal housing 6. The RF connector socket can be N-type, BNC, IPEX, etc.

[0017] The sensing electrode 1, coupling electrode 2, voltage dividing electrode 3, and insulating layer 4 are all centered in a square cutout. The sensor employs a 3-layer electrode structure, fabricated from a 4-layer printed circuit board. Three of these layers are covered with copper foil. The insulating layer 4 between the copper foils uses FR4 or other materials. The dielectric constant of different materials and the thickness of the substrate are related to the final coupling capacitance value. The sensor's shape is as follows... Figure 2 As shown. The size and shape of the printed circuit board can be changed as needed, the detection frequency band is in the range of 1MHz to 100MHz, and the bandwidth is greater than 10MHz.

Claims

1. A partial discharge sensor using coupling capacitance, characterized in that, It includes an induction plate (1), a coupling plate (2), a voltage dividing plate (3), and an insulating layer (4); the induction plate (1) and the coupling plate (2) form a coupling capacitor, the coupling plate (2) and the voltage dividing plate (3) form a voltage dividing capacitor, an insulating layer (4) is provided between the induction plate and the coupling plate (2), and an insulating layer (4) is provided between the coupling plate (2) and the voltage dividing plate (3).

2. The partial discharge sensor based on coupling capacitance according to claim 1, characterized in that, The induction plate (1), coupling plate (2) and voltage dividing plate (3) are fabricated using the same printed circuit board.

3. The partial discharge sensor using coupling capacitance method according to claim 1, characterized in that, The insulating layer (4) is made of FR4, and the induction plate (1), coupling plate (2) and voltage dividing plate (3) are made of copper foil.

4. The partial discharge sensor based on coupling capacitance according to claim 1, characterized in that, The coupling plate (2) is connected to the RF connector core wire (5), and the voltage divider plate (3) is connected to the RF connector housing (6).

5. The partial discharge sensor based on coupling capacitance according to claim 1, characterized in that, The partial discharge sensor has a detection frequency band in the range of 1MHz to 100MHz, and the bandwidth is greater than 10MHz.

6. A distribution transformer, characterized in that, It has a coupling capacitor method partial discharge sensor as described in any one of claims 1 to 5.

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