Cable localization in line monitoring device

I. Core technology and working principle

1. Mainstream detection technologies

• High-frequency pulsed current method: Coupling the discharge pulse from the cable ground wire through an open-close current sensor, combined with a double-ended positioning algorithm, enables highly accurate positioning under ideal conditions. The technology complies with international standards, detects small localized discharge signals, and supports high-speed sampling and noise rejection algorithms.
• UHF methodThe ultra-wide frequency band is covered by an ultra-high frequency sensor that captures electromagnetic waves generated by electrical discharges, making it suitable for detecting internal defects in GIS equipment and high-voltage cables, and effectively suppressing external interference.
• Multi-modal fusion technology: Integrate UHF, ultrasonic, transient earth voltage (TEV) and temperature and humidity detection to enhance diagnostic accuracy in complex environments through multi-dimensional data cross-analysis.

2. Key technical features

• high sensitivity: Most devices capture early signals of insulation degradation, ensuring effective monitoring of weak discharges.
• Precision Sampling: High-speed processors and high-resolution analog-to-digital conversion ensure that signal details are preserved intact.
• Intelligent Positioning: Double-ended localization techniques can narrow down the scope of the fault, and the UHF method can initially locate to a specific area of the equipment.

II. Typical application scenarios

1. High voltage cable networks::
   • Long-term monitoring of cables of 10kV and above voltage levels, focusing on vulnerable parts such as joints and terminals. Through real-time analysis of cable insulation status, combined with the background database to match the type of faults, providing a basis for operation and maintenance decisions.
2. Intelligent Substation::
   • Cooperative monitoring with GIS, transformers and other equipment to build the insulation health management system of the whole power station. Support fiber optic communication and remote alarm, applicable to substations of different voltage levels.
3. urban electric power distribution network::
   • For compact equipment such as ring network cabinets and switchgear, the combination of non-contact sensors is used to support non-stop installation and edge computing to shorten the maintenance response time.

III. System components and functions

1. hardware architecture

• sensor layerIncluding high-frequency current sensors, ultra-high frequency antennas, ultrasonic probes, etc., some of which support wireless transmission to reduce the difficulty of construction.
• data processing layer: Edge nodes integrate industrial computers for signal filtering, feature extraction and preliminary diagnosis.
• Cloud Platform: Transmits data via 5G or fiber optics, uses deep learning models to predict remaining insulation life, and generates 3D visual diagnostic reports.

2. core functionality

• Real-time monitoringThe following parameters are displayed: discharge amount, phase, frequency, etc., and PRPS/PRPD graph analysis is supported.
• Intelligent Alarm: Setting multi-level thresholds and avoiding the expansion of accidents through multiple ways of warning.
• historical retrospect: Stores long-term data, supports trend analysis and fault reproduction, and assists in the development of operation and maintenance strategies.

IV. Industry trends and progress in localization

1. Direction of technology evolution::
   • Multiple Physical Field Fusion: Combine optical, acoustic, and electromagnetic signals to enhance defect recognition in complex environments.
   • digital twin: Constructing virtual equipment models to simulate the insulation aging process for predictive maintenance.
   • Edge Intelligence: Most of the data analysis is done at the endpoint, reducing the load on the cloud and improving responsiveness.
2. Accelerated substitution of localization::
   • Domestic manufacturers in the sensor design, algorithm optimization and other aspects of the breakthrough in foreign monopoly, some product performance to reach the international level.
   • The industry has jointly developed technical specifications to promote cross-vendor equipment mutual recognition and reduce procurement costs.

V. Selection and implementation recommendations

1. Technical route selection::
   • New projects give priority to UHF or multimodal fusion solutions, and older equipment retrofit can choose non-contact solutions.
   • Long distance cables are recommended to be equipped with double-ended positioning systems, and GIS equipment is recommended to have built-in UHF sensors.
2. Elements of implementation::
   • anti-interference designMetal shielded enclosure, bandpass filtering and noise sensors are used to ensure signal-to-noise ratios are up to standard.
   • Installation Specifications: Keep the sensor at a safe distance from the cable head, and the wireless sensor needs to avoid strong electromagnetic areas.
   • data security: Encrypted transmission is used, in compliance with the relevant security protection regulations.

VI. Typical cases

• A 220kV substation: Deploying localized on-line monitoring systems to accurately locate discharge points through double-ended positioning technology, detecting insulation aging hazards in advance and avoiding unplanned power outages.
• Urban core distribution networkThe 4-in-1 sensor covers the 10kV ring network cabinet, and combined with the edge computing terminal to filter environmental noise in real time, the false alarm rate is significantly reduced, and the operation and maintenance efficiency is greatly improved.