my country's AC/DC hybrid transmission mode has gradually formed, which has also led to the problem of mutual interference between AC and DC systems. When the DC line has a single-maximum loop operation, the DC current flowing into the earth through the grounding pole of the DC system will have an impact on the power transformer in the AC power system. The main manifestation is that the neutral point of the transformer flows through the DC and the core is biased. The DC bias causes the transformer vibration to increase, the noise increases, and the harmonics increase.
The detection sensitivity is high, and the minimum detection limit for dissolved C2H2 in oil can reach 0.1ppm. Pumpless vacuum degassing technology does not require a vacuum pump, which improves the reliability and stability of the system. The oil and gas separation is safe and reliable, and does not pollute. The discharge and non-discharge of transformer oil can be selected by the user; The oil and gas separation speed is fast, only about 15 minutes, and the special environmental adaptation technology is adopted to eliminate the influence of temperature and humidity changes on the gas distribution coefficient; It can detect H2, CO, CO2, CH4, C2H2, C2H4, C2H6 and more than seven kinds of gas and micro water content in transformer oil, and can upload spectrum, spectrum and other raw data is completely open to users. Use a dedicated composite chromatographic column to improve the separation of gas components; Use imported special detector to improve the detection sensitivity of hydrocarbon gas; High-stability, high-precision gas detection technology, with an error range of ± 10%; Strong environmental adaptability, successfully applied to high-cold, high-temperature, high-humidity and high-altitude areas; High anti-interference performance, electromagnetic compatibility performance meets GB/T17626 and IEC61000 standards; Two-level alarm function is provided, and the alarm signal can be transmitted remotely; Open database, which can be connected to the local area network of the power system; Faster analysis cycle, the minimum monitoring cycle is 60 minutes, which can be set by the user, and the recommended detection cycle is 12 hours; The analyzed oil sample adopts degassing and buffer treatment technology to eliminate the bubbles contained in the oil sample of the re-injected transformer body. Multi-layer isolation re-injection (oil return) technology absolutely guarantees that the carrier gas will not be brought into the transformer body; The lowest detection limit of C2H2 can reach 0.1-0.5 μ L/L; The system is equipped with secondary gas threshold alarm and growth rate alarm functions. The alarm concentration and growth rate can be set arbitrarily. Equipped with an expert system for judging latent faults, the latest oil chromatographic fault diagnosis technology adopts the IEC60599 standard and the improved fuzzy three-ratio method, David's triangle, cubic diagram method and other methods, which users can choose at will. With historical data trend graph query, report format display and printing functions, it is convenient to compare the monitoring data longitudinally, so as to analyze the transformer operation status and fault development trend. Support the IEC 61850 communication standard, optical fiber or twisted pair is optional. The system has a high degree of integration, and the components can be equipped with iron core ground current and ambient temperature and humidity monitoring functions. It adopts dual-loop multi-mode constant temperature control, with a temperature control accuracy of ± 0.1 ℃, and the equipment is equipped with an automatic constant temperature industrial air conditioner; The functional interface circuit adopts optocoupler isolation design to further improve the anti-interference performance of the system; Using Ethernet, it can realize all-digital, remote data transmission, control and parameter setting; High scalability, can be easily integrated with other monitoring devices; No cylinder design, no need to replace the carrier gas every year, greatly reducing the amount of after-sales maintenance, and there is no high-voltage container next to the transformer, the equipment safety is fully guaranteed, and there are no safety hazards. The analysis software has a friendly man-machine interface, an all-Chinese interface, simple operation and rich system functions. The core device has a standard 19-inch rack structure, compact structure, small size, easy maintenance and screen assembly.
Insulation faults of high-voltage switchgear are mainly manifested as external insulation-to-ground flashover breakdown, internal insulation-to-ground flashover breakdown, phase-to-phase insulation flashover breakdown, lightning overvoltage flashover breakdown, porcelain bushing, capacitor bushing flashover Networking, pollution flashover, flashover, breakdown, explosion, lifting rod flashover, CT flashover, breakdown, explosion, porcelain bottle fracture, etc. Various insulation defects develop to the final breakdown, and they often go through the partial discharge stage before they lead to accidents. The strength of the partial discharge can reflect the insulation status in time. Therefore, the online monitoring of the partial discharge to determine the insulation status is to realize the online monitoring of the switchgear insulation. And effective means of diagnosis.
The arrester monitoring device is mainly used for real-time and online monitoring of the full current, discharge current and cumulative action times of MOA arresters. The arrester monitoring device adopts a current sampling method with no residual voltage and full isolation, which is mainly composed of a current transformer, A/D conversion, single-chip microcomputer and RS485 communication module. The current transformer uses a single-turn primary core-through current transformer, and the measurement result is used on a bus To transfer. The arrester monitoring device adopts advanced compensation technology, so it has good versatility and interchangeable measurement.
The ETCR5500 series ground resistance detection sensor breaks through the traditional detection method and adopts clamp-type non-contact measurement. It is widely used in the ground resistance measurement of electric power, telecommunications, meteorology, oil fields, construction and industrial electrical equipment. Magnetic shielding technology and CT technology can ensure high precision, high reliability, and high stability for year-round uninterrupted testing. The ETCR5500 series is divided into a clamp-shaped open-loop structure and a closed-loop structure, as well as a long jaw and a round jaw. The long jaw is particularly suitable for flat steel grounding occasions and can meet the detection of various grounding systems. For the grounding system that forms a loop, there is no need to disconnect the grounding down conductor, and no auxiliary electrode is needed, which is safe and time-saving.
JC-OM200/MOA type lightning arrester online monitoring device adopts high-precision active zero flux through-core transformer, and automatically selects the magnification according to the measured current to achieve high-precision measurement; adopts dynamic phasor compensation algorithm to achieve high-precision Measurement signal analysis; adopts digital filtering algorithm to eliminate the "zero drift problem" caused by analog filters; adopts distributed measurement structure, that is, on-site measurement and digital transmission; live installation, that is, no main equipment power-off installation is required, which is convenient and fast Connected to the system, the measurement data is communicated with the IED through RS485.
Use solar power supply system to supply power or wire diagram induction to take power, which is convenient for installation and maintenance; Flexible communication mode, support ZIGBEE/WIFLGSM/CDMA/GPRS and 4G network; It is an industrial-grade product, using a waterproof metal shell, anti-electromagnetic interference, suitable for various harsh climate environments; the system adopts a low-power design, and adopts a dynamic power management strategy to meet power saving requirements; Equipped with complete background software. With functions such as data storage, historical data query, report form, printing, graph drawing, etc., it can perform qualitative and quantitative analysis and trend prediction of the leakage current of the insulator in operation; It supports controlled collection mode and automatic collection mode. The sampling interval (5 minutes to 24 hours), alarm threshold and other parameters can be set through the background software. Support the use of mobile phones for data query and alarm reception; Meet the State Grid Corporation's corporate standard ``General Technical Specifications for Transmission Line Condition Monitoring Devices'' (Q/GDW 242-2010).
◆Processing output unit: closed type, outdoor type is equipped with rainproof box ◆Sensor: closed type, with lower lead (provided by GIS sensor manufacturer) ◆Locking unit: with lock contact ◆Reliability: The inductive (non-contact) sensor detects whether the line is electrified outside the safe distance of the line, and has obvious directivity, high sensitivity, safety and reliability. ◆Economical: The sensor does not directly contact the charged body, and there is no need to do partial discharge test during installation and maintenance. It is simple and convenient, low maintenance cost, and long service life. ◆Complete functions: with indicator signal remote transmission function and equipment self-checking function. ◆Adaptability: It has various forms and can be widely used in various places such as indoors, outdoors, GIS combined electrical appliances and switch cabinets.
System detection frequency band: 300MHz~1500MHz; Minimum monitorable: -75dBm discharge capacity in the laboratory, -70 dBm discharge capacity in the field; The system can measure discharge capacity, discharge phase, discharge times, and discharge pulse resolution is less than 10μs, and can provide relevant statistical parameters according to customer requirements; The system can display power frequency periodic discharge graphs, two-dimensional (Q-φ, N-φ, N-Q) and three-dimensional (N-Q-φ) discharge spectra; Provides many functions such as discharge development trend analysis, alarm setting, historical query and report printing; The system can automatically start monitoring at regular intervals to realize the automation of the entire monitoring process, and it can also start and close the monitoring system manually in real time; The system has built-in four standard discharge mode libraries, which can identify discharge types, evaluate insulation defects caused by different types of discharge trends, and give alarms for abnormal conditions; The system structure complies with the Smart Substation Guidelines Q / GDW 383-2009 "Technical Guidelines for Smart Substations", which is suitable for the intelligent transformation of substations and new intelligent substations. The data server in the system station control layer cabinet has CAC function, built-in I2 data interface and directly communicates with the current state monitoring system of power transmission and transformation equipment of various provincial companies.
The comprehensive monitoring, analysis, and diagnosis of power operation equipment have always been problems that the power sector is looking forward to solving. In particular, the accumulation of transformer operation management experience has provided a considerable amount of domain expertise and fault symptoms for the establishment of the power transformer insulation diagnosis expert system. It has been able to gradually carry out analysis, judgment, and decision-making research on the fault and life of the operating equipment, so as to reach the status Monitoring and diagnosis, the purpose of establishing a predictive maintenance system. On-line monitoring of power transformers is an important means to reflect the operating status of equipment in a timely and accurate manner. Partial discharge detection of transformers and chromatographic analysis of gas in oil are the main methods to reflect the insulation status during operation.
The anti-interference effect is remarkable. Researched and developed a dual-sensor directional coupling pulse identification system (two patented technologies) with independent intellectual property rights, and comprehensively applied multiple anti-interference methods such as digital filtering, phase windowing, and dynamic threshold to effectively eliminate or suppress interference and ensure acquisition The data is accurate and reliable. According to the principle of virtual instrument, adopt PC-DAQ system structure, LabVIEW programming, and realize various functions by software. It has powerful functions, strong flexibility, easy to expand multi-parameter monitoring and multiple equipment tour monitoring, and easy to maintain and upgrade. The system is safe, stable and easy to manage.
Based on the National Grid "Technical Guidelines for Smart Substations" and "Intelligent Technical Specifications for High-Voltage Electrical Equipment" ◆ The technology is backed by the State Key Laboratory of Electrical Insulation for Power Equipment, Xi’an Jiaotong University ◆ Developed on the basis of years of online monitoring product development and successful operation ◆ Provide a comprehensive solution for online monitoring of smart substations ◆ Successfully applied to national key projects such as State Grid, China Southern Power Grid, Five Power Generation Groups, PetroChina and the Three Gorges of the Yangtze River, and provided factory supporting facilities for domestic backbone power equipment factories
The partial discharge detection analyzer (BYPDM) is a multi-functional, multi-purpose portable device, suitable for partial discharge (Partial Discharge, PD) live detection of transformers, GIS, cables, switch cabinets and other equipment. The partial discharge detector also comes with partial discharge acquisition and analysis software, with a flexible user interface, which is convenient for you to accurately judge the characteristics of partial discharge.
This system can be used for real-time monitoring of the partial discharge status of GIS of 126kV and above. It can automatically convert partial discharge activity data into graphics and management report formats and upload them to the server, automatically send out alarms for the degree of danger of partial discharge activities, notify users by email or SMS, and provide auxiliary analysis and maintenance of GIS status Basis for decision-making.
It can measure the ambient temperature, relative humidity and dew point temperature in the terminal box and cabinet in real time, intelligently control dehumidification, and prevent condensation on site.