CN209432948U - Ultrasonic scanning array device for substation partial discharge monitoring - Google Patents

Abstract

The utility model discloses an ultrasonic scanning array device for substation partial discharge monitoring. A guide rail with the same distance from the electrical cabinet is arranged on the electrical cabinet to be monitored, and a trolley with a microphone array is arranged on the guide rail. The trolley drives the microphone array along the The guide rail goes around the electrical cabinet, so as to realize the monitoring and positioning of partial discharge, so as to realize the daily partial discharge inspection of the substation. The utility model realizes the partial discharge monitoring and positioning of multiple devices through a single array scanning operation, reduces the configuration cost, and makes the monitoring and positioning of the partial discharge possible in the daily inspection of the substation.

Description

Ultrasonic scanning array device for substation partial discharge monitoring

technical field

The utility model relates to the technical field of substation intelligent inspection, in particular to an ultrasonic scanning array device for substation partial discharge monitoring.

Background technique

Partial discharge (hereinafter referred to as partial discharge) is a kind of discharge process in which the electric field distribution between charged conductors is uneven, and a complete conductive channel is not formed on the surface or inside of the insulator. Partial discharges have a cumulative effect that can cause insulation degradation in equipment and eventually lead to equipment failure. There are various medium and high voltage electrical equipment such as switch cabinets and transformers in the substation. During the operation of the equipment, factors such as overvoltage, humid environment, and production defects of insulating parts may cause partial discharge. It can be considered that partial discharge is an inevitable event in the substation, and partial discharges that occur repeatedly at the same point will eventually lead to interference. The loss increases, and even causes insulation breakdown. Therefore, substation partial discharge monitoring is an important part of electrical equipment condition monitoring.

At present, a variety of partial discharge monitoring methods have been proposed, such as: pulse current method, ultra-high frequency method, ultrasonic detection method and so on. Among them, the pulse current method is susceptible to interference, and the ultra-high frequency method is more difficult to realize. The ultrasonic detection method uses the 50-300kHz acoustic wave characteristic signal generated during partial discharge to realize partial discharge monitoring. When a single microphone is used in the current method, the presence or absence of partial discharge can only be monitored, but the specific position of partial discharge cannot be monitored. When multiple microphones are used to form an array, the localization of PD sources can be realized through a variety of positioning algorithms, which brings great convenience to the maintenance work. The microphone array is mostly arranged with 9-16 microphones. It is complex and the system cost is high. It is mostly used to locate the PD source of a single faulty device, and cannot be applied to the daily inspection of substations.

Utility model content

The purpose of this utility model is to overcome the deficiencies of the prior art and provide an ultrasonic scanning array device for substation partial discharge monitoring, which has a compact structure and can realize daily partial discharge inspection of substations through a single microphone array.

A technical solution to achieve the above purpose is: an ultrasonic scanning array device for substation partial discharge monitoring, including a microphone array for ultrasonic scanning of electrical cabinets, and also includes guide rails, trolleys and signal processing units;

The microphone array includes a microphone bracket and a microphone module, and the microphone modules are evenly distributed on one side of the microphone bracket; the microphone array is arranged at the bottom of the trolley, facing the electrical cabinet; the signal processing unit is installed on On the trolley, connect with the microphone modules one by one;

The trolley is connected to the guide rail through pulleys, and the guide rail is U-shaped around the electrical cabinet. The horizontal height of the guide rail is the same everywhere, and the distance from the electrical cabinet is the same everywhere.

Further, for several electrical cabinets arranged side by side, the guide rails surrounding the electrical cabinets in a U-shape are arranged in a serpentine connection.

Further, the back of the microphone array is provided with sound damping material.

Further, the trolley is provided with a driving device and a steering device.

The utility model relates to an ultrasonic scanning array device for substation partial discharge monitoring. By setting guide rails at the same distance from the electrical cabinet on the electrical cabinet to be monitored, a trolley with a microphone array is set on the guide rail, and the trolley drives the microphone array along the guide rail. Bypass the electrical cabinet to realize partial discharge monitoring and partial discharge positioning, so as to realize the daily partial discharge inspection of the substation. The utility model realizes the partial discharge monitoring and positioning of multiple devices through a single array scanning operation, reduces the configuration cost, and makes the monitoring and positioning of the partial discharge possible in the daily inspection of the substation.

Description of drawings

Fig. 1 is a front view of an ultrasonic scanning array device for substation partial discharge monitoring of the present invention;

Fig. 2 is a top view of an ultrasonic scanning array device for substation partial discharge monitoring of the utility model;

Fig. 3 is a structural schematic diagram of a trolley 3 of an ultrasonic scanning array device for partial discharge monitoring in a substation of the present invention;

Fig. 4 is a schematic diagram of partial discharge position calculation using an ultrasonic scanning array device for partial discharge monitoring in a substation of the present invention.

Detailed ways

In order to better understand the technical solution of the present utility model, it will be described in detail below through specific embodiments in conjunction with the accompanying drawings:

Please refer to Fig. 1 to Fig. 3, an ultrasonic scanning array device for substation partial discharge monitoring of the present invention includes a microphone array 1 for ultrasonic scanning of an electrical cabinet 5, and also includes a guide rail 2, a trolley 3 and a signal processing unit 4.

Referring to FIG. 3 , the microphone array 1 includes a microphone bracket 11 and a microphone module 12 , and the microphone modules are evenly distributed on one side of the microphone bracket 11 . The microphone array 1 is arranged at the bottom of the trolley 3 , facing the electrical cabinet 5 . The back of the microphone array 1 is provided with an acoustic damping material to suppress the multipath effect of the partial discharge signal propagation, so that the microphone module 12 only receives the partial discharge signal propagated through the air path. The signal processing unit 4 is installed on the trolley 3 and connected with the microphone modules 12 one by one. The partial discharge signal is converted into an electrical signal by the microphone module 12, modulated by the signal processing unit 4 and sent back to the data processing system in the station via wireless.

Dolly 3 is connected with guide rail 2 through pulley 31. The U-shaped guide rail 2 is set around the electrical cabinet 5 to form a guide rail unit. The horizontal height of the guide rail 2 is the same everywhere, and the distance from the electrical cabinet 5 is everywhere the same, so that the microphone array 1 can collect the sound at any position at a fixed height on the front and rear sides of the electrical cabinet 5. Ultrasonic signal. The trolley 3 is equipped with a driving device and a steering device. The trolley 3 moves under control on the guide rail 2. The guide rail 2 is equipped with a number of position markers. The trolley 3 accumulates the stroke between the marker positions to form its own position information and runs to the marker position. time to correct the position. For several electrical cabinets arranged side by side, the U-shaped guide rails 2 surrounding the electrical cabinets are provided with serpentine connections. During normal inspection, the device is in the inspection mode, the trolley 3 moves along the track at a constant speed, and the microphone array 1 only monitors the presence or absence of partial discharge characteristic signals. When a partial discharge event is detected, the device enters the positioning mode, the trolley 3 reciprocates on the front and rear sides of the target area, and the microphone array 1 follows the trolley to continuously scan to realize the localization of the partial discharge source.

Please refer to Figure 4, the positioning principle is briefly described below:

The angle information between the discharge source and the reference point can be calculated by capturing the arrival time difference of the same characteristic signal by each microphone in the ultrasonic array. The principle diagram of array positioning is shown in the schematic diagram of positioning principle 4. Without loss of generality, the center of the connection between the sensor support and the trolley support is taken as the reference point, and the plane parallel to the xoz plane and containing the PD source x is defined as the PD source cross-section. When the array modules are arranged in two dimensions such as L-shape and square, the azimuth and elevation angles (φ, θ) can be obtained. When the array modules are arranged in a one-dimensional linear array, only the elevation angle θ can be obtained. In order to highlight the characteristics of the scanning operation of the microphone array, the following mainly focuses on the description of the one-dimensional line array of the microphone. In the utility model, since the microphone array can be moved, when the partial discharge develops to occur repeatedly in seconds, the maximum pitch angle θ _max can be obtained when the array module moves to the section of the partial discharge source, as long as it reciprocates in the target area , capture θ _max , that is, get the y-axis position F _y of the discharge source, then measure the pitch angle θ' _max of the PD source relative to the reference point at the same horizontal position x on the opposite side of the equipment, and obtain the discharge source position according to the following formula:

Among them, Cz is the z-axis coordinate of point C, Fx is the x-axis coordinate of point F, and so on. In the formula, Fx and Fz are the quantities to be obtained, and the rest are known, and the equations are solved simultaneously, and combined with the previously measured Fy, the F coordinate of the partial discharge source is obtained.

The orientation angle and elevation angle information of the reference point relative to the PD source can be obtained by array signal processing algorithms such as MUSIC and Fast DOA.

When the microphone array is a linear array, partial discharge needs to occur repeatedly to determine the location of the partial discharge source. Since sporadic partial discharge may be caused by factors such as overvoltage and humid environment, only repetitive partial discharge can reflect the insulation problem of the equipment. Therefore, the microphone The scanning and inspection of the line array can meet the operation and maintenance requirements of the substation. When the equipment needs to monitor occasional partial discharge, it can also be configured with a two-dimensional microphone array, and the trolley stays at the position of the equipment between inspection intervals for continuous partial discharge monitoring.

PD damage to equipment insulation is cumulative. The PD positioning data formed by multiple inspections can be stored in the database for regular statistics to provide data support for equipment condition maintenance.

Those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the utility model, rather than as a limitation to the utility model, as long as within the spirit of the utility model, the above-mentioned The changes and modifications of the embodiments will all fall within the scope of the claims of the present utility model.

Claims (4)

1. a kind of substation's partial discharge monitoring ultrasonic scanning array apparatus, the microphone array including carrying out ultrasonic scanning to electrical cabinet Column, which is characterized in that further include guide rail, trolley and signal processing unit；

The microphone array includes microphone arm and microphone module, and the microphone module is evenly arranged on the microphone branch The side of frame；The microphone array is arranged in the trolley bottom, towards the electrical cabinet；The signal processing unit device On the trolley, it is connect one by one with the microphone module；

The trolley is connect by pulley with the guide rail, and the guide rail U-shaped is arranged around the electrical cabinet, the guide rail Level height is identical everywhere, and the distance away from the electrical cabinet is identical everywhere.

2. a kind of substation's partial discharge monitoring ultrasonic scanning array apparatus according to claim 1, which is characterized in that for Several electrical cabinets arranged side by side, U-shaped are arranged around the guide rail of the electrical cabinet using snakelike connection.

3. a kind of substation's partial discharge monitoring ultrasonic scanning array apparatus according to claim 1, which is characterized in that described The back side of microphone array is equipped with acoustic damping material.

4. a kind of substation's partial discharge monitoring ultrasonic scanning array apparatus according to claim 1, which is characterized in that described Trolley is equipped with driving device and transfer.