A digital casing device

Abstract

The present invention discloses a digital bushing device, which relates to the technical field of power transmission and transformation. It consists of three parts: internal insulation, external insulation and metal components. The internal insulation is composed of a capacitor core, oil, insulating paper, aluminum foil electrodes or semiconductor paper, and epoxy resin. A conductive rod is provided at the center inside the capacitor core, and insulating paper is wound around the conductive rod. Aluminum foil electrodes or semiconductor paper are cross-distributed among the insulating paper layers to jointly form a concentric cylinder capacitor. The external insulation includes a composite external insulation umbrella skirt, and the composite external insulation umbrella skirt is connected to the outside of the capacitor core through oil or epoxy resin. The metal components include a terminal block and a flange, and a test tapping device and a voltage tapping device are installed on the flange. The device of the present invention can transmit voltage and current signals and has an on-line monitoring function, providing digital guarantee for on-line monitoring and analysis of high-voltage AC and DC power transmission equipment, and having broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation, and particularly to a digital bushing device. Background Art

[0002] In high-voltage AC and DC power transmission, it is often affected by various line faults, equipment defects, communication blockages, etc., and cannot meet the operating requirements of power generation, transmission, and transformation. Among them, ferroresonance overvoltage faults occurring at the voltage tap of the bushing occur frequently during system operation. Therefore, studying its mechanism and effective monitoring are of great significance for the safe and stable operation of power stations.

[0003] High-voltage AC and DC power transmission equipment operates under live conditions for a long time. The operating condition of the equipment is monitored in two ways: one is planned maintenance, that is, maintenance every quarter or half year; the other is condition-based maintenance, that is, online monitoring. This method analyzes the historical operating data of the equipment, predicts its trend, diagnoses and estimates the good condition of the equipment, and then determines the maintenance items, frequency, and content. With the development of power technology, the requirements for the reliability of power generation, transmission, power supply, and consumption are getting higher and higher. Focusing on the development of key directions such as intelligent power consumption and energy efficiency management, as well as the popularization and application of information processing technologies such as digitization and blockchain, the transformation of electrical equipment from planned maintenance to condition-based maintenance has become a trend. To prevent potential hazards of high-voltage AC and DC power transmission equipment and reduce accidents and equipment damage during operation, it has become inevitable to conduct online inspections, tests, or monitoring on high-voltage AC and DC power transmission equipment.

[0004] As a key equipment in a substation, online monitoring of its components is of great significance. Among them, the bushing is an important component of the transformer. The online monitoring of transformer bushings includes the following: analysis of dissolved gases in transformer oil, partial discharge, winding deformation, bushing dielectric loss factor, capacitance measurement, voltage division value, transmitted current, etc. The transformer bushing outputs voltage signals and current signals through the voltage tap device at the bushing flange under operating conditions and transmits them to the power station control room to achieve digital monitoring means. The control room analyzes whether there is a fault risk in the line based on the voltage value or current value and determines the maintenance items, frequency, and content using data changes. This digitally characterized bushing can directly give monitoring values and judge whether there are defects or faults in the operating transformer equipment, which plays an important role in quickly diagnosing faults of high-voltage AC and DC power transmission equipment.

[0005] There are two components for online monitoring of the signal transmission of transformer bushings: one is to transmit data through the test tap device of the bushing; the other is to transmit signals to the substation control room through the voltage tap device of the bushing. The data transmitted by the test tap device can monitor a small amount of data such as the dielectric loss factor, capacitance, and partial discharge value of the bushing. The voltage tap device can monitor a variety of data. This double-tap bushing can select whether to use the voltage tap or the test tap device according to the user's usage requirements.

[0006] Based on this, it is particularly necessary to design a digital bushing device that can transmit voltage and current values and has an online monitoring function. Summary of the Invention

[0007] Aiming at the deficiencies in the existing technology, the purpose of the present invention is to provide a digital bushing device, which has a simple structure and reasonable design. The device can transmit voltage and current signals and has an online monitoring function, providing digital guarantee for the online monitoring and analysis of high-voltage AC and DC transmission equipment, with wide applicability and easy to promote and use.

[0008] To achieve the above purpose, the present invention is realized through the following technical solutions: A digital bushing device is composed of three parts: internal insulation, external insulation, and metal components. The internal insulation is composed of a capacitor core, oil, insulating paper, aluminum foil electrodes or semiconductor paper, and epoxy resin. A conductive rod is arranged at the center inside the capacitor core, and insulating paper is wound around the conductive rod. Aluminum foil electrodes or semiconductor paper are cross-distributed in the insulating paper layer to jointly form a concentric cylindrical capacitor. A grading sphere is installed at the end of the capacitor core; the external insulation includes a composite external insulation umbrella skirt, and the composite external insulation umbrella skirt is connected to the outside of the capacitor core through oil or epoxy resin. The metal components include a terminal block and a flange. The terminal block and the flange are respectively located at the upper and lower ends of the composite external insulation umbrella skirt, and a test tap device and a voltage tap device are installed on the flange.

[0009] Preferably, the composite external insulation umbrella skirt is made of a silicone rubber outer sleeve or a porcelain sleeve.

[0010] Preferably, the lead wire of the test tap device is led out from the end screen electrode, and the lead wire of the voltage tap device is led out from the sub-end screen electrode. There is a certain insulation thickness between the voltage tap device and the test tap device to prevent breakdown, and the size of the voltage tap device is larger than that of the test tap device.

[0011] Preferably, the voltage tap device sends voltage signals and current signals to the control room to monitor the online operation status of the equipment. The voltage tap device is connected to the transformer through an acquisition unit box composed of a measurement optical fiber and RC resistors and capacitors, and transmits the signals to the substation computer-aided equipment to read the voltage and current signals.

[0012] Preferably, the voltage tap device monitors the dielectric loss factor, capacitance, and partial discharge value of the bushing body to timely detect the insulation condition of the bushing body.

[0013] Preferably, the end face of the flange is fixed on the transformer riser, and the part of the bushing above the flange end face is exposed to the air, while the part below the flange end face is immersed in the transformer oil.

[0014] The beneficial effects of the present invention: This device has two tap devices, and users can choose which tap device to use according to their needs. This voltage tap with a standardized design can transmit voltage and current signals and has an online monitoring function, providing digital guarantee for the online monitoring and analysis of high-voltage AC and DC transmission equipment, and has a broad application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be described in detail below in conjunction with the drawings and specific embodiments;

[0016] Figure 1 is a schematic structural diagram of the present invention. SPECIFIC EMBODIMENTS

[0017] To make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0018] Refer to Figure 1 , the following technical solutions are adopted in this specific embodiment: A digital bushing device is composed of three parts: inner insulation, outer insulation, and metal components. The inner insulation is composed of a capacitive core 7, oil, insulating paper, aluminum foil electrodes or semiconductor paper, and epoxy resin. A conductive rod 1 is arranged at the center inside the capacitive core 7. Insulating paper is wound around the conductive rod 1, and aluminum foil electrodes or semiconductor paper are cross-distributed among the insulating paper layers to jointly form a concentric cylindrical capacitor. A grading sphere 8 is installed at the end of the capacitive core 7; the outer insulation includes a composite outer insulation umbrella skirt 3, and the composite outer insulation umbrella skirt 3 is connected to the outside of the capacitive core 7 through oil or epoxy resin. The metal components include a terminal block 2 and a flange 6. The terminal block 2 and the flange 6 are respectively located at the upper and lower ends of the composite outer insulation umbrella skirt 3, and a test tap device 4 and a voltage tap device 5 are installed on the flange 6.

[0019] It should be noted that the composite outer insulation umbrella skirt 3 is made of a silicone rubber outer sleeve or a porcelain sleeve.

[0020] In addition, the end face of the flange 6 is fixed on the transformer riser, and the part of the bushing above the flange end face is exposed to the air, while the part below the flange end face is immersed in the transformer oil.

[0021] This specific embodiment has two types of tapping devices, namely voltage taps and test taps. Among them, the leads of the test tap device 4 are led out from the end screen electrode, and the leads of the voltage tap device 5 are led out from the penultimate screen electrode. There is a certain insulation thickness between the voltage tap device 5 and the test tap device 4 to prevent insulation breakdown between the voltage tap and the test tap caused by voltage increase. The voltage signal output from the voltage tap device reaches several thousand volts. Therefore, the voltage withstand level of the voltage tap device 5 is higher, and its external dimensions are larger than those of the test tap device 4. The voltage tap device 5 complies with IEEE StdC57.19.01 "Standard Performance Parameters and Dimensions of Outdoor Bushings", and the dimensions of the test tap device 4 are flexible without rigid requirements.

[0022] The voltage tap device 5 in this specific embodiment can send voltage signals and current signals to the control room to monitor the on-line operation status of the equipment. The voltage tap device 5 is connected to the transformer through an acquisition unit box composed of a measurement optical fiber and RC resistors and capacitors, and transmits the signals to the substation computer-aided equipment to read voltage value and current value signals. At the same time, the voltage tap device 5 can also monitor the dielectric loss factor, capacitance, and partial discharge quantity value of the bushing body to detect the insulation status of the bushing body in time.

[0023] This specific embodiment is made using the principle of series capacitor voltage division, and has wide applicability. It can be used for domestic and international power transmission and transformation equipment, has strong domestic and international generality, meets the requirements of international equipment standards, provides digital guarantee for on-line monitoring and analysis of high-voltage AC and DC power transmission equipment, and has broad market application prospects.

[0024] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A digital casing device, characterized in that, It consists of three parts: inner insulation, outer insulation and metal components. The inner insulation is composed of a capacitor core (7), oil, insulating paper, aluminum foil electrodes or semiconductor paper, and epoxy resin. A conductive rod (1) is arranged at the inner center of the capacitor core (7). Insulating paper is wound around the conductive rod (1), and aluminum foil electrodes or semiconductor paper are cross - distributed among the insulating paper layers to jointly form a concentric cylinder capacitor. A grading ball (8) is installed at the end of the capacitor core (7). The outer insulation includes a composite outer insulation umbrella skirt (3), and the composite outer insulation umbrella skirt (3) is connected to the outside of the capacitor core (7) through oil or epoxy resin. The metal components include a terminal block (2) and a flange (6). The terminal block (2) and the flange (6) are respectively located at the upper and lower ends of the composite outer insulation umbrella skirt (3). A test tap device (4) and a voltage tap device (5) are installed on the flange (6). The composite outer insulation umbrella skirt (3) is made of a silicone rubber outer sleeve or a porcelain sleeve. The lead wire of the test tap device (4) is led out from the end - screen electrode, and the lead wire of the voltage tap device (5) is led out from the sub - end - screen electrode. The size of the voltage tap device (5) is larger than that of the test tap device (4), and there is an insulating thickness to prevent breakdown between the voltage tap device (5) and the test tap device (4).

2. A digital casing device according to claim 1, characterized in that, The voltage tap device (5) sends voltage signals and current signals to the control room to monitor the on - line operation status of the equipment.

3. A digital casing device according to claim 1, characterized in that, The voltage tap device (5) is connected to the transformer through an acquisition unit box composed of a measurement optical fiber, RC resistors and capacitors, and transmits the signals to the substation computer - aided equipment to read voltage and current signals.

4. A digital casing device according to claim 1, characterized in that, The voltage tap device (5) monitors the dielectric loss factor, capacitance and partial discharge value of the bushing body to timely detect the insulation condition of the bushing body.

5. A digital casing device according to claim 1, characterized in that, The end face of the flange (6) is fixed on the transformer riser. The part of the bushing above the flange end face is exposed to the air, and the part below the flange end face is immersed in the transformer oil.

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