CN207832951U - A kind of capacitance type potential transformer insulation line monitoring device - Google Patents

Abstract

The utility model provides an on-line monitoring device for the insulation of a capacitive voltage transformer, comprising: a resistor, a high-voltage wire, a capacitive voltage transformer, a shielded test line, a voltage waveform tester, a test insulated wire and a background monitor; The voltage transformer consists of a transformer body and a transformer tail end connected in series. The resistor is connected in series with the transformer body and in parallel with the transformer tail end. The shielded test line is connected to the transformer tail end and the voltage waveform tester to test the connection of the insulated wire. The da, dn terminals of the transformer and the voltage waveform tester, the voltage waveform tester transmits the detected voltage to the background monitor. According to the principle of circuit series voltage division and parallel connection, the on-line monitoring device provided by the utility model can monitor the insulation status of the body and tail end of the capacitive voltage transformer on-line in real time.

Description

A capacitive voltage transformer insulation on-line monitoring device

technical field

The present application relates to the technical field of high-voltage power equipment, and in particular to an on-line insulation monitoring device for capacitive voltage transformers.

Background technique

The capacitive voltage transformer is divided by series capacitors, and then stepped down and isolated by the electromagnetic transformer, which is used as a voltage transformer for meters, relay protection, etc. It is widely used in 110kV and above power systems to provide accurate voltage signals for power system protection, measurement and metering. Due to its small impact strength, small size, light weight, and the advantages of reliable damping of ferromagnetic resonance and excellent transient response characteristics in practical applications, it is gradually replacing electromagnetic voltage transformers and is a must in power grids. less equipment.

Capacitive voltage transformers are mainly composed of capacitive voltage dividers and medium voltage transformers. The capacitive voltage divider is composed of a porcelain sleeve and several series capacitors installed in it. The porcelain sleeve is filled with insulating oil to maintain a positive pressure of 0.1MPa, and steel bellows are used to balance different environments to maintain oil pressure. The capacitor voltage divider can be used as a coupling The capacitor is connected to the carrier device. The medium-voltage transformer consists of a transformer, compensation reactor, lightning arrester and damping device installed in a sealed oil tank, and the space on the top of the oil tank is filled with nitrogen. The primary winding consists of the main winding and the trimming winding, and a low-loss reactor is connected in series between the primary side and the primary winding.

It is required in the preventive test procedure that the capacitance voltage transformer should be tested for inter-electrode insulation resistance, capacitance value and tanδ every 3 years. Capacitive voltage transformers have been found in the pre-test every 3 years. The tail end is soaked in water and damp, and the insulation is seriously reduced; during operation, there are also many cases of capacitance breakdown inside the transformer due to moisture, aging and other reasons. , which in turn leads to equipment defects such as increased dielectric loss and abnormal secondary voltage. In severe cases, explosions may occur, causing serious consequences. Therefore, it is necessary to monitor the capacitor voltage transformer. Through monitoring, the operation status of the capacitor voltage transformer can be grasped, the fault of the capacitor voltage transformer can be found in time, and the fault can be eliminated early, so as to minimize the damage of the fault.

Utility model content

The purpose of the utility model is to provide an on-line monitoring device for the insulation of a capacitive voltage transformer to solve the problem that there is no on-line monitoring device for the insulation of a capacitive voltage transformer in existing power grid projects.

The utility model provides a capacitive voltage transformer insulation on-line monitoring device, comprising: a resistor, a high-voltage wire, a capacitive voltage transformer, a shielded test line, a voltage waveform tester, a test insulated wire and a background monitor;

The capacitive voltage transformer includes a body and a tail end, one end of the body is a high-voltage end, the other end of the body is a low-voltage end, the tail end is connected in series with the low-voltage end, and the high-voltage wire is connected to the high-voltage end connected, the resistor is connected in parallel with the tail end and connected in series with the body;

One end of the shielded test line is connected to the tail end, the other end of the shielded test line is connected to the voltage waveform tester, the shielding layer of the shielded test line is grounded, and one end of the test insulated wire is connected to the The da and dn terminals of the capacitive voltage transformer are connected, and the other end of the test insulated wire is connected with the voltage waveform tester; the voltage waveform tester is electrically connected with the background monitor.

Preferably, the resistance of the resistor is 8Ω.

Preferably, one end of the resistor is connected in series with the transformer body, and the other end is grounded.

It can be seen from the above technical solutions that the utility model provides an on-line monitoring device for the insulation of a capacitive voltage transformer, including: a resistor, a high-voltage wire, a capacitive voltage transformer, a shielded test wire, a voltage waveform tester, a test insulated wire and background monitoring instrument; the capacitive voltage transformer includes a body and a tail end, one end of the body is a high-voltage end, the other end of the body is a low-voltage end, the tail end is connected in series with the low-voltage end, and the high-voltage wire is connected to the low-voltage end The high voltage end is connected, the resistor is connected in parallel with the tail end and connected in series with the body; one end of the shielded test line is connected to the tail end, and the other end of the shielded test line is connected to the The voltage waveform tester is connected, the shielding layer of the shielded test wire is grounded, one end of the test insulated wire is connected to the da and dn ends of the capacitive voltage transformer, and the other end of the test insulated wire is connected to the The voltage waveform tester is connected; the voltage waveform tester is electrically connected with the background monitor.

Description of drawings

In order to illustrate the technical solution of the present application more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, on the premise of not paying creative labor, Additional drawings can also be derived from these drawings.

Fig. 1 is a schematic diagram of a capacitive voltage transformer insulation on-line monitoring device provided by the utility model;

Fig. 2 is a schematic diagram of a capacitive voltage transformer in a capacitive voltage transformer insulation on-line monitoring device provided by the utility model.

Illustration: 1-resistor; 2-high voltage wire; 3-capacitive voltage transformer; 31-transformer body; 311-high voltage end; 312-low voltage end; 32-transformer tail; ; 5-voltage waveform tester; 6-test insulated wire; 7-background monitor.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution in the utility model, the technical solution in the utility model embodiment will be clearly and completely described below in conjunction with the accompanying drawings in the utility model embodiment. Obviously, The described embodiments are only some of the embodiments of the present utility model, but not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

Please refer to Figure 1 to Figure 2, which is an embodiment of a capacitive voltage transformer online monitoring device provided by the utility model, including: a resistor 1, a high-voltage wire 2, a capacitive voltage transformer 3, a shielded test line 4, a voltage Waveform tester 5, test insulated wire 6 and background monitor 7;

The capacitive voltage transformer 3 includes a transformer body 31 and a transformer tail end 32. One end of the transformer body 31 is a high-voltage end 311, and the other end of the transformer body 31 is a low-voltage end 312. The transformer tail The terminal 32 is connected in series with the low-voltage terminal 312, the high-voltage wire 2 is connected with the high-voltage terminal 311, and the resistor 1 is connected in parallel with the transformer tail end 32 while being connected in series with the transformer body 31;

One end of the shielded test line 4 is connected to the tail end 32, the other end of the shielded test line 4 is connected to the voltage waveform tester 5, the shielding layer of the shielded test line 4 is grounded, and the test One end of the insulated wire 6 is connected with the da, dn ends of the capacitive voltage transformer 3, and the other end of the test insulated wire 6 is connected with the voltage waveform tester 5; the voltage waveform tester is connected with the background The monitor is electrically connected.

In the embodiment of the utility model, the high-voltage end 311 of the transformer body 31 is connected to the high-voltage wire 2, the low-voltage end 312 of the transformer body 31 is connected in series with the tail end 32 of the transformer, and the resistor 1 is connected in parallel with the tail end 32 of the transformer. It is connected in series with the low-voltage terminal 312, and the resistor 1 is grounded, so that the tail end 32 of the transformer forms a capacitance to the ground, and it is connected in parallel with the resistor 1 at the same time.

Preferably, the resistance value of the resistor 1 is set to 8Ω, which can meet the requirement of collecting the voltage accuracy at the tail end 32 of the transformer; and will not change the voltage distribution inside the transformer, thereby affecting the requirements of the secondary voltage test. The utility model has no limitation on the types and models of the capacitive voltage transformer 3 and the resistor 1 .

In the embodiment of the utility model, one end of the wire core with the shielded test wire 4 is connected to the tail end 32 of the transformer, the other end is connected to the voltage waveform tester 5, and the shielding layer is grounded; The terminals da and dn are respectively connected to the voltage waveform tester 5 ; and then the voltage waveform tester 5 is connected to the background monitor 7 .

During the power transmission process, if the transformer body 31 is affected by moisture or insulation breakdown, according to the principle of circuit series voltage division, the voltage division on the tail end 32 of the transformer and the resistor 1 increases, while the voltage on the secondary side of the transformer decreases; If the transformer tail end 32 is damp, the transformer body 31 is well insulated, and according to the circuit parallel shunt principle, the voltage across the resistor 1 decreases. When the transformer tail end 32 is seriously damaged, the voltage across the resistor 1 drops to zero. Therefore, the insulation conditions of the transformer body 31 and the transformer tail end 32 can be monitored by obtaining the voltage at both ends of the resistor 1, and then the pre-test period of the transformer can be adjusted.

The voltage waveform tester 5 collects and transmits the voltage information on the secondary side of the transformer and the voltage at both ends of the resistor 1 and transmits it to the background monitor 7. 31 and the insulation status of the transformer tail end 32 to judge.

Other embodiments of the utility model will be readily apparent to those skilled in the art after consideration of the specification and practice of the utility model disclosed herein. This application is intended to cover any modification, use or adaptation of the utility model, which follows the general principles of the utility model and includes common knowledge or common knowledge in the technical field not disclosed by the utility model. conventional technical means. The specification and examples are to be considered exemplary only, with the true scope and spirit of the invention being limited by the claims.

It should be understood that the present invention is not limited to the precise structure which has been described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (3)

1. a kind of capacitance type potential transformer insulation line monitoring device, which is characterized in that including：Resistance (1), high-voltage conducting wires (2), capacitance type potential transformer (3), band shielding p-wire (4), voltage waveform test instrument (5), test insulated conductor (6) and after Platform monitor (7)；

The capacitance type potential transformer (3) includes mutual inductor ontology (31) and mutual inductor tail end (32), the mutual inductor ontology (31) one end is high-pressure side (311), and mutual inductor ontology (31) other end is low-pressure end (312), the mutual inductor tail end (32) connect with the low-pressure end (312), the high-voltage conducting wires (2) connect with the high-pressure side (311), the resistance (1) with It is connected in series with the mutual inductor ontology (31) while the mutual inductor tail end (32) is connected in parallel；

Band shielding p-wire (4) one end is connect with the tail end (32), the band shield p-wire (4) other end with it is described Voltage waveform test instrument (5) connects, the shielding layer grounding of the band shielding p-wire (4), and the one of the test insulated conductor (6) End is connect with the end da, dn of the capacitance type potential transformer (3), the other end and the electricity of the test insulated conductor (6) Corrugating tester (5) connects；The voltage waveform test instrument is electrically connected with the background monitoring instrument.

2. a kind of capacitance type potential transformer insulation line monitoring device as described in claim 1, it is characterised in that：The electricity The resistance value for hindering (1) is 8 Ω.

3. a kind of capacitance type potential transformer insulation line monitoring device as described in claim 1, it is characterised in that：The electricity Resistance (1) one end is connected with mutual inductor ontology (31), other end ground connection.